Chondroitin sulphate (CS) glycosaminoglycan chains on cell and extracellular matrix proteoglycans (PGs) can no longer be regarded as merely hydrodynamic space fillers. Overwhelming evidence over recent years indicates that sulphation motif sequences within the CS chain structure are a source of significant biological information to cells and their surrounding environment. CS sulphation motifs have been shown to interact with a wide variety of bioactive molecules, e.g. cytokines, growth factors, chemokines, morphogenetic proteins, enzymes and enzyme inhibitors, as well as structural components within the extracellular milieu. They are therefore capable of modulating a panoply of signalling pathways, thus controlling diverse cellular behaviours including proliferation, differentiation, migration and matrix synthesis. Consequently, through these motifs, CS PGs play significant roles in the maintenance of tissue homeostasis, morphogenesis, development, growth and disease. Here, we review (i) the biodiversity of CS PGs and their sulphation motif sequences and (ii) the current understanding of the signalling roles they play in regulating cellular behaviour during tissue development, growth, disease and repair.

Introduction

Chondroitin sulphate (CS) and its sulphation motifs on cell-associated, pericellular and extracellular matrix (ECM) proteoglycans (PGs) represent a significant repository of information in tissues with the capacity to encode functional information rivalling that of RNA, DNA and proteins [1]. This information is realised when CS and its sulphation motifs interact with growth factors, cytokines, morphogenetic proteins, enzymes, inhibitors and pericellular matrix (PCM)- and ECM-stabilising glycoproteins. Such interactions have diverse effects on cellular metabolism, proliferation and differentiation, cell migration, matrix synthesis/stabilisation and tissue remodelling in development and are critical to the cellular control of tissue homeostasis. CS sulphation motifs on cell-associated, PCM and ECM PGs also provide important molecular recognition and activity signals to stem/progenitor cell niches facilitating the sequestration of combinations of growth factors, cytokines and chemokines which maintain the niche microenvironment ensuring stem cell survival and their maintenance in a state of quiescent self-renewal within the niche environment. Perturbations in the signals, which stem cells receive in this niche, can also orchestrate stem/progenitor cell differentiation and pluripotency resulting in stem cell activation and proliferation into specific cell lineages with migratory properties facilitating their participation in tissue growth, development and repair processes.

Virtually, every cell in the human body is surrounded by a dense glycocalyx of glycoconjugates consisting of mixtures of glycoproteins, PGs and glycolipids which provide a protective and interactive barrier [2]. CS is a prominent glycosaminoglycan (GAG) component of many of these molecules and is the most abundant GAG in the human body [3]. The glycocalyx connects the cell to its external microenvironment and components in the glycocalyx act as biosensors through which cells perceive and respond to changes in the environment they live in [4,5]. The endothelial glycocalyx also has mechanosensory shear and compression responsive functions, which regulate mechanotransductive effects on endothelial cell signalling and vascular permeability, which are important in the nutrition and development of tissues [2,59]. In the brain, the glycocalyx of microglia and oligodendrocytes contain cell surface sialic acid-binding immunoglobulin-like lectins (SIGLECS), which identify sialic acids in cell surface glycoconjugates in adjacent neurons facilitating cellular communication and signalling through an intracellular immunoreceptor tyrosine-based inhibition motif which maintains a homeostatic balance in neuronal cells [4]. Embryonic stem cells (ESCs) also assemble a glycocalyx-containing cell surface epitope which not only can be used to identify specific stages of stem cell differentiation but also serve as interactive modules that can network with regulatory cues received from the ECM influencing stem cell differentiation [2]. The endothelial and epithelial glycocalyx also have important roles to play in inflammation and immunomodulation [10]. MUC1 (CD227), a high molecular mass (>400 kDa) widely distributed, multifunctional, type-1 membrane-tethered epithelial glycoprotein, has roles in dendritic cells, monocytes, and T- and B-cells in immune-mediated inflammatory processes [11]. MUC1 in the mucosal lining also provides a protective lubricative barrier to microbial infection [12,13]. The cerebrovascular glycocalyx also has important roles to play in neural protection; SIGLECS protect neurons from acute toxicity through interaction with glycolipids, which provide barrier functions [14,15]. The glycocalyx displays brain-specific functions through its participation in interactions with cell surface receptors, which undertake protein phosphorylation-mediated signalling by neurons and can also influence apoptosis and amyloid deposition [7]. GAG components in the glycocalyx have important roles in neuroprotection through interactions with CS receptors and participation in cell signalling events which maintain cellular integrity and also preserve the tissue hydration provided by GAGs to the PCM and ECM.

The biodiversity of ECM and cell-associated molecules decorated with CS GAG chains

CS (Figure 1) is composed of β1-3 and β1-4 linked d-glucuronic acid and N-acetyl d-galactosamine repeat disaccharide units which can be O-sulphated at the 2, 4 and C6 positions [16]. Furthermore, the d-glucuronic acid moiety may also be epimerised to αl-iduronic acid in the related GAG dermatan sulphate (DS) leading to a considerable degree of structural diversity in CS/DS and the ability to interact with a large range of cytokines, chemokines, morphogens and growth factors which regulate cellular proliferation and differentiation and tissue development [1625]. CS also has indispensable roles to play in stem cell differentiation and the attainment of pluripotency [26].

The complexity of the CS chains of proteoglycans.

Figure 1.
The complexity of the CS chains of proteoglycans.

Organisation of GAG saccharides in full length, partially depolymerised, terminal (a) and stub epitopes (b) of the CS side chains of PGs and in the GAG disaccharides in CS types A, B, C, D, E (c) and simplified diagrams of the sulphate presentations in a typical CS side chain (eg). In the example shown, the chain is terminated in a 3-B-3(−) epitope and contains internal 7-D-4 and 4-C-3 epitopes as shown. A 3-B-3(+) stub epitope attached to the linkage tetrasaccharide is also shown, and this epitope is generated by chondroitinase ABC. The CS side chains can also be terminated in an alternate 2-B-6(−) epitope and have a 2-B-6(+) stub epitope.

Figure 1.
The complexity of the CS chains of proteoglycans.

Organisation of GAG saccharides in full length, partially depolymerised, terminal (a) and stub epitopes (b) of the CS side chains of PGs and in the GAG disaccharides in CS types A, B, C, D, E (c) and simplified diagrams of the sulphate presentations in a typical CS side chain (eg). In the example shown, the chain is terminated in a 3-B-3(−) epitope and contains internal 7-D-4 and 4-C-3 epitopes as shown. A 3-B-3(+) stub epitope attached to the linkage tetrasaccharide is also shown, and this epitope is generated by chondroitinase ABC. The CS side chains can also be terminated in an alternate 2-B-6(−) epitope and have a 2-B-6(+) stub epitope.

CS (Figure 1) decorates a remarkably diverse collection of matrix and cell-associated macromolecules (Figures 24). Their functional properties are summarised in Table 1 and their structural features are shown diagrammatically in Figures 24. CS occurs as many isomeric forms, referred to as CS-A, CS-C or CS-D based on the mono- or disulphate positions (Figure 1j). CS-B, also known as DS, like CS-A is sulphated at the C4 position of N-acetyl d-galactosamine, but differs due to epimerisation of d-glucuronic acid to l-iduronic acid and this is sulphated at C2.

Structural organisation of extracellular matrix proteoglycans.

Figure 2.
Structural organisation of extracellular matrix proteoglycans.

Diagrammatic representation of the sub-domain structural organisation of SRPX2 and members of the hyalectan family (a), Decorin and biglycan SLRP members (b), and the inter-photoreceptor ECM PG SPACRCAN (c). SUSHI complement control protein modular data were obtained from the public SMART database (http://smart.embl-heidelberg.de/).

Figure 2.
Structural organisation of extracellular matrix proteoglycans.

Diagrammatic representation of the sub-domain structural organisation of SRPX2 and members of the hyalectan family (a), Decorin and biglycan SLRP members (b), and the inter-photoreceptor ECM PG SPACRCAN (c). SUSHI complement control protein modular data were obtained from the public SMART database (http://smart.embl-heidelberg.de/).

Table 1
Form and functions of CS/DS PGs
Protein (alternative name) Gene Distribution Function Ref. 
Aggrecan (CSPG1) ACAN Widespread in ECM, cartilage, tendon, IVD Tissue hydration, space-filling, weight bearing proteoglycan in cartilage, IVD, forms protective perineural nets with HA and tenascin-C, has, roles in heart development. [283,284
Versican (CSPG2) VCAN Widespread in ECM, CNS So named as a “versatile” proteoglycan based on its ability to promote cell proliferation, differentiation, cell migration in tissue remodelling and in connective tissue morphogenesis [285287
Neurocan (CSPG3) NCAN CNS Brain lecticans HA binding proteoglycans interactive with NCAM, Ng-CAM/L1. Modulate cell binding in CNS development and neurite outgrowth activity in CNS/PNS. Upregulated in glial scars, inhibits astrocyte and neuronal growth, may act antagonistically with other brain PGs to regulate neurogenesis. Primary astrocytes and neural cell lines bind brevican independently of HA, controlling infiltration of axons and dendrites into maturing glomeruli in brain development. [288,289
Brevican (CSPG7) BCAN CNS, One of the most abundant brain proteoglycans 
Chondroitin sulphate-4 (NG2) CSPG4 Widespread distribution in ECM and CNS with roles in development. Integral transmembrane proteoglycan. Found on the surface of immature oligodendrocyte and chondroblastic progenitor cells. Roles in cell-PCM stabilisation, cellular proliferation, migration, inhibits neurite outgrowth during axonal regeneration. May sequester FGF-2/PDGF. CSPG4 is a collagen VI transduction receptor activating FAK/ERK1/ERK2. Widely expressed by tumour cells and is specifically targeted by therapeutic measures combatting tumourogenesis. up-regulated in spinal cord injury and in chondrogenesis [56,141
Neuroglycan-C CSPG5 CNS Transmembrane CS-proteoglycan bearing an EGF ECM domain, acts as an active growth factor and ligand for ErbB3, sixth member (neuroregulin-6) of the neuroregulin family. Contains CS-E, CS-C [290,291
Syndecan-1 SDC1 Widespread distribution in vascular, epithelial and weight bearing connective tissues and brain CS-E chains found in Syndecan-1, 3. Widely distributed cell surface CS and HS substituted PGs also containing CS-E and CS-C. Midkine interacts with CS-E motif and participates in neural development and repair but interacts weakly with CS-A and CS-C. [82,292, 293
Syndecan-4 SDC4 
Phosphacan PTPRZ1 CS-KS-HNK-1 proteoglycan, known as receptor-type tyrosine-protein phosphatase zeta (PTPR−ζ). Widespread distribution in CNS/PNS CS-KS-HNK-1 proteoglycan also known as receptor-type tyrosine-protein phosphatase zeta (PTPR−ζ) single pass type 1 membrane protein with cytoplasmic tyrosine protein phosphatase, carbonic anhydrase and fibronectin type III domains. Alternative splice forms exist. DSD-1 is the mouse homologue. Roles in embryonic spinal cord development/neurogenesis. Contains CS-D which promotes embryonic axonal growth in CNS in mice. 473HD CS epitope in phosphacan has roles in neural precursor cell proliferation [294[147,152, 294,295
Chondrocyte and SMC perlecan HSPG2 CS/HS hybrid proteoglycan found in cartilage, IVD, meniscus, tendon and blood vessels CS replaces some HS chains in perlecan domain 1 in articular and growth plate cartilage, 4,6-disulphated CS found in growth plate perlecan regulates collagen fibrillogenesis. Roles in ECM stabilisation, growth factor-receptor transfer and activation. Cell proliferation and differentiation, cell signalling. [43,44
Leprecan PRH1 Basement membrane 100 kDa Leu-Pro enriched CS-proteoglycan of basement membrane of cardiac and skeletal muscle, central nervous system (cerebral cortex and cerebellum), intestinal tract, trachea, ear, skin, liver, and kidney. Localises to the vascular basement membrane/smooth muscle in each organ. Also expressed in the notochord during embryonic chordate development. May also have roles in the secretory pathway and as a growth suppressor. [296298
Thrombomodulin THBD Endothelial cell membrane Endothelial cofactor proteoglycan with roles in the thrombin induced activation of Protein C anticoagulant pathway. [299,300
Decorin DCN CS substituted decorin and biglycan are found in bone, but DS forms are normally found in cartilage and skin SLRPs have roles in ECM organisation/stabilisation/collagen fibrillogenesis. Facilitates cell signalling through interaction with inflammatory cytokines (IL-1, TNF-α) and growth factors (BMPs, WISP-1) and their receptors (EGF-R, IGFIR) affecting cell proliferation, survival, adhesion, migration, matrix synthesis. Controls the bioavailability of TGF-β regulates tissue fibrosis. Biglycan interacts with complement system and TLR4 in innate immune regulation. [38,301303
Biglycan BGN 
Asporin ASPN Susceptibility gene in OA ASPN is unique among the SLRPs in not having a GAG at its N terminus but contains an Aspartic acid repeat region which binds TGF-β BMP-2 to negatively regulate chondrogenesis and osteogenesis. [304
Epiphycan EPYC DS SLRP found in epiphyseal cartilage Epiphycan contains 7 LRRs instead of 10–11 LRRs like other SLRP members, related to osteoglycin [305
Bikunin (ITI) AMBP Liver serum serine proteinase inhibitor, also synthesised by IVD cells, chondrocytes and meniscal cells Stabilises the condensed HA layer in growth plate hypertrophic region, and around oocytes, proteinase inhibitory activity, anti-bacterial, antiviral, anti-metastatic, immune-modulatory and growth promoting properties [91,306, 307
Appican APP Brain CS-A and CS-E brain proteoglycan (Amyloid precursor protein) [5053, 161
Sushi repeat protein X-linked 2 SRPX2 SRPX2 is a CS-proteoglycan which is overexpressed in gastrointestinal cancer and has roles in synaptogenesis SPRX2 is significantly upregulated in colon cancer and its expression levels correlates with tumour aggressiveness. SRPX2 siRNA markedly down regulates β-catenin, MMP-2 and -9 expression reducing tumour cell proliferation, adhesion and migration via the Wnt/β-catenin pathway. SRPX2 promotes synaptogenesis in the cerebral cortex. Mutations in SRPX2 result in Roland epilepsy and speech impairment (RESDX syndrome). Cathepsin B, ADAMTS-4 and uPAR - binding partners of SPRX2 in neural tissues. [308,309] [163165, 167,171, 308
Interphotoreceptor matrix proteoglycan 2 (SPACRCAN) IMPG2 Eye interphotoreceptor matrix IMPG2, interphotoreceptor matrix proteoglycan-2 [39
Serglycin SRGN Mast cells, platelets, macrophages, T-lymphpocytes, leucocytes Mast cell serglycin is substituted with heparin side chains, macrophage serglycin has CS (CS-A, CS-E) side chains [120,121
Endoglycan PODXL2 CD-34 sialomucin transmembrane proteoglycan family member Contains extensive substitution with sialic acid and N- and O- linked glycan [310
CD44 CD44 CD44 V3 splice variants bearing CS chains have reduced affinity for HA CD44 binds Ezrin, fibrin/fibrinogen, fibronectin, HA, osteopontin, Selectins-P, -E, -L. Ubiquitous HA receptor [311
Miscellaneous neuroendocrine cell granule-pro-hormones 
Dermcidin proteolysis inducing factor DCD Neurons and endocrine cells Anion exchange, Chondroitinase ABC MS proteomics screen used to identify intracellular CS-DS proteins. Chromogranin-A, Secretogranin-1, 2, 3. Dermcidin, Neuropeptide W, Cholecystokinin, granule bone marrow cell CS-PGs and collagen and calcium-binding EGF domain-containing protein-1. [312321
Parathyroid secretory protein-1 (Chromogranin-A) CHGA 
Cholecystokinin (Pancreozymin) CCK 
Protein (alternative name) Gene Distribution Function Ref. 
Aggrecan (CSPG1) ACAN Widespread in ECM, cartilage, tendon, IVD Tissue hydration, space-filling, weight bearing proteoglycan in cartilage, IVD, forms protective perineural nets with HA and tenascin-C, has, roles in heart development. [283,284
Versican (CSPG2) VCAN Widespread in ECM, CNS So named as a “versatile” proteoglycan based on its ability to promote cell proliferation, differentiation, cell migration in tissue remodelling and in connective tissue morphogenesis [285287
Neurocan (CSPG3) NCAN CNS Brain lecticans HA binding proteoglycans interactive with NCAM, Ng-CAM/L1. Modulate cell binding in CNS development and neurite outgrowth activity in CNS/PNS. Upregulated in glial scars, inhibits astrocyte and neuronal growth, may act antagonistically with other brain PGs to regulate neurogenesis. Primary astrocytes and neural cell lines bind brevican independently of HA, controlling infiltration of axons and dendrites into maturing glomeruli in brain development. [288,289
Brevican (CSPG7) BCAN CNS, One of the most abundant brain proteoglycans 
Chondroitin sulphate-4 (NG2) CSPG4 Widespread distribution in ECM and CNS with roles in development. Integral transmembrane proteoglycan. Found on the surface of immature oligodendrocyte and chondroblastic progenitor cells. Roles in cell-PCM stabilisation, cellular proliferation, migration, inhibits neurite outgrowth during axonal regeneration. May sequester FGF-2/PDGF. CSPG4 is a collagen VI transduction receptor activating FAK/ERK1/ERK2. Widely expressed by tumour cells and is specifically targeted by therapeutic measures combatting tumourogenesis. up-regulated in spinal cord injury and in chondrogenesis [56,141
Neuroglycan-C CSPG5 CNS Transmembrane CS-proteoglycan bearing an EGF ECM domain, acts as an active growth factor and ligand for ErbB3, sixth member (neuroregulin-6) of the neuroregulin family. Contains CS-E, CS-C [290,291
Syndecan-1 SDC1 Widespread distribution in vascular, epithelial and weight bearing connective tissues and brain CS-E chains found in Syndecan-1, 3. Widely distributed cell surface CS and HS substituted PGs also containing CS-E and CS-C. Midkine interacts with CS-E motif and participates in neural development and repair but interacts weakly with CS-A and CS-C. [82,292, 293
Syndecan-4 SDC4 
Phosphacan PTPRZ1 CS-KS-HNK-1 proteoglycan, known as receptor-type tyrosine-protein phosphatase zeta (PTPR−ζ). Widespread distribution in CNS/PNS CS-KS-HNK-1 proteoglycan also known as receptor-type tyrosine-protein phosphatase zeta (PTPR−ζ) single pass type 1 membrane protein with cytoplasmic tyrosine protein phosphatase, carbonic anhydrase and fibronectin type III domains. Alternative splice forms exist. DSD-1 is the mouse homologue. Roles in embryonic spinal cord development/neurogenesis. Contains CS-D which promotes embryonic axonal growth in CNS in mice. 473HD CS epitope in phosphacan has roles in neural precursor cell proliferation [294[147,152, 294,295
Chondrocyte and SMC perlecan HSPG2 CS/HS hybrid proteoglycan found in cartilage, IVD, meniscus, tendon and blood vessels CS replaces some HS chains in perlecan domain 1 in articular and growth plate cartilage, 4,6-disulphated CS found in growth plate perlecan regulates collagen fibrillogenesis. Roles in ECM stabilisation, growth factor-receptor transfer and activation. Cell proliferation and differentiation, cell signalling. [43,44
Leprecan PRH1 Basement membrane 100 kDa Leu-Pro enriched CS-proteoglycan of basement membrane of cardiac and skeletal muscle, central nervous system (cerebral cortex and cerebellum), intestinal tract, trachea, ear, skin, liver, and kidney. Localises to the vascular basement membrane/smooth muscle in each organ. Also expressed in the notochord during embryonic chordate development. May also have roles in the secretory pathway and as a growth suppressor. [296298
Thrombomodulin THBD Endothelial cell membrane Endothelial cofactor proteoglycan with roles in the thrombin induced activation of Protein C anticoagulant pathway. [299,300
Decorin DCN CS substituted decorin and biglycan are found in bone, but DS forms are normally found in cartilage and skin SLRPs have roles in ECM organisation/stabilisation/collagen fibrillogenesis. Facilitates cell signalling through interaction with inflammatory cytokines (IL-1, TNF-α) and growth factors (BMPs, WISP-1) and their receptors (EGF-R, IGFIR) affecting cell proliferation, survival, adhesion, migration, matrix synthesis. Controls the bioavailability of TGF-β regulates tissue fibrosis. Biglycan interacts with complement system and TLR4 in innate immune regulation. [38,301303
Biglycan BGN 
Asporin ASPN Susceptibility gene in OA ASPN is unique among the SLRPs in not having a GAG at its N terminus but contains an Aspartic acid repeat region which binds TGF-β BMP-2 to negatively regulate chondrogenesis and osteogenesis. [304
Epiphycan EPYC DS SLRP found in epiphyseal cartilage Epiphycan contains 7 LRRs instead of 10–11 LRRs like other SLRP members, related to osteoglycin [305
Bikunin (ITI) AMBP Liver serum serine proteinase inhibitor, also synthesised by IVD cells, chondrocytes and meniscal cells Stabilises the condensed HA layer in growth plate hypertrophic region, and around oocytes, proteinase inhibitory activity, anti-bacterial, antiviral, anti-metastatic, immune-modulatory and growth promoting properties [91,306, 307
Appican APP Brain CS-A and CS-E brain proteoglycan (Amyloid precursor protein) [5053, 161
Sushi repeat protein X-linked 2 SRPX2 SRPX2 is a CS-proteoglycan which is overexpressed in gastrointestinal cancer and has roles in synaptogenesis SPRX2 is significantly upregulated in colon cancer and its expression levels correlates with tumour aggressiveness. SRPX2 siRNA markedly down regulates β-catenin, MMP-2 and -9 expression reducing tumour cell proliferation, adhesion and migration via the Wnt/β-catenin pathway. SRPX2 promotes synaptogenesis in the cerebral cortex. Mutations in SRPX2 result in Roland epilepsy and speech impairment (RESDX syndrome). Cathepsin B, ADAMTS-4 and uPAR - binding partners of SPRX2 in neural tissues. [308,309] [163165, 167,171, 308
Interphotoreceptor matrix proteoglycan 2 (SPACRCAN) IMPG2 Eye interphotoreceptor matrix IMPG2, interphotoreceptor matrix proteoglycan-2 [39
Serglycin SRGN Mast cells, platelets, macrophages, T-lymphpocytes, leucocytes Mast cell serglycin is substituted with heparin side chains, macrophage serglycin has CS (CS-A, CS-E) side chains [120,121
Endoglycan PODXL2 CD-34 sialomucin transmembrane proteoglycan family member Contains extensive substitution with sialic acid and N- and O- linked glycan [310
CD44 CD44 CD44 V3 splice variants bearing CS chains have reduced affinity for HA CD44 binds Ezrin, fibrin/fibrinogen, fibronectin, HA, osteopontin, Selectins-P, -E, -L. Ubiquitous HA receptor [311
Miscellaneous neuroendocrine cell granule-pro-hormones 
Dermcidin proteolysis inducing factor DCD Neurons and endocrine cells Anion exchange, Chondroitinase ABC MS proteomics screen used to identify intracellular CS-DS proteins. Chromogranin-A, Secretogranin-1, 2, 3. Dermcidin, Neuropeptide W, Cholecystokinin, granule bone marrow cell CS-PGs and collagen and calcium-binding EGF domain-containing protein-1. [312321
Parathyroid secretory protein-1 (Chromogranin-A) CHGA 
Cholecystokinin (Pancreozymin) CCK 

Abbreviations: CNS, central nervous system; NCAM, neural cell adhesion molecule; PCM, pericellular matrix; FAK, focal adhesion kinase; ERK, extracellular-regulated kinase; LRR, leucine-rich repeat; SLRP, small leucine repeat PG; TLR4, Toll-like receptor-4; MS, mass spectrometry.

The CS–PGs represent a biodiverse group of molecules

The Hyalectans

The Hyalectans are a group of large HA interactive CS–PGs [2731] (Figure 2a). Aggrecan and versican form aggregate structures with HA which provide tissues with an ability to act as weight-bearing and tension-resisting structures, while neurocan, brevican and aggrecan hyalectans form perineural-net structures through interaction with HA and tenascin-R (Figure 5a). Perineuronal nets have neuroprotective roles [32,33], but also inhibit neuronal repair processes by inhibiting neurite outgrowth, both of these functions are due to the particular GAGs, which decorate these PGs. Similar network structures between aggrecan, link protein and hyaluronan are also prominently featured in cartilaginous tissues where they have roles in weight bearing (Figure 5b).

The structural complexity of cell associated CS-proteoglycans.
Figure 3.
The structural complexity of cell associated CS-proteoglycans.

Structural organisation of cell-associated CS–PGs. CSPG4 (a), thrombomodulin (b), RPTP/Phosphacan (c), syndecan family (d) and a CS-substituted variant of the HA receptor CD44 (e). Abbreviations not covered in key: ED, extracellular domain; TMD, transmembrane domain; CD, cytoplasmic domain.

Figure 3.
The structural complexity of cell associated CS-proteoglycans.

Structural organisation of cell-associated CS–PGs. CSPG4 (a), thrombomodulin (b), RPTP/Phosphacan (c), syndecan family (d) and a CS-substituted variant of the HA receptor CD44 (e). Abbreviations not covered in key: ED, extracellular domain; TMD, transmembrane domain; CD, cytoplasmic domain.

Structural organisation of miscellaneous proteoglycans.
Figure 4.
Structural organisation of miscellaneous proteoglycans.

Organisation of the Kunitz protease inhibitor CS–PG, bikunin (a), type IX collagen (b) and testican, seminal plasma CS–PG (c).

Figure 4.
Structural organisation of miscellaneous proteoglycans.

Organisation of the Kunitz protease inhibitor CS–PG, bikunin (a), type IX collagen (b) and testican, seminal plasma CS–PG (c).

Macromolecular organisation of proteoglycan structures in neural tissues and in articular cartilage.
Figure 5.
Macromolecular organisation of proteoglycan structures in neural tissues and in articular cartilage.

Diagrammatic CS–PGs assembled into protective perineural nets in the brain tissue (a) and ternary link protein stabilised macro-aggregate structures with hyaluronan in articular cartilage (b) which convey important hydrodynamic weight-bearing and self-lubricative properties to this tissue.

Figure 5.
Macromolecular organisation of proteoglycan structures in neural tissues and in articular cartilage.

Diagrammatic CS–PGs assembled into protective perineural nets in the brain tissue (a) and ternary link protein stabilised macro-aggregate structures with hyaluronan in articular cartilage (b) which convey important hydrodynamic weight-bearing and self-lubricative properties to this tissue.

The small leucine-rich PGs

The small leucine-rich PG (SLRP) family have well-known functional roles in the regulation of collagen fibrillogenesis, but have additional cell regulatory roles through their interactive properties with cytokines, growth factors and morphogens [3438]. Decorin and biglycan are two SLRPs which contain one or two CS chains and, in specific contexts, DS (Figure 2b).

SPACRCAN

SPACRCAN is a novel 400 kDa CS–PG of the inter-photoreceptor ECM providing an interface between the photoreceptors and the pigmented retinal epithelium in the fundus of the eye [39]. SPACRCAN contains 6-sulphated CS chains and many N- and O-linked oligosaccharides which collectively constitute ∼60% of its total mass (Figure 2c). SPACRCAN has two RHAMM-like binding domains through which it interacts with HA to form an aggregate structure which organises the ECM and is also important in the hydration of this tissue [40].

Perlecan

Perlecan is a HS–PG in vascular tissues; however, chondrocytes and smooth muscle cells synthesise a hybrid form of perlecan where CS chains replace some of its HS chains [4146]. Epithelial perlecan is also a hybrid perlecan and a unique PG containing HS, CS and KS chains [47]. The form of perlecan synthesised by foetal IVD progenitor cells contains 7-d-4 CS sulphation motifs [48]. The GAG side chains of perlecan in growth plate cartilage contain embedded 4,6-disulphated CS-E disaccharides that direct collagen fibrillogenesis [49] and are also found in the brain PG, appican interacting with neuroregulatory factors, which direct neuritogenesis [5052].

Appican

Oversulphated disaccharides of CS-D and CS-E (Figure 1j) regulate neuronal adhesion, cell migration and neurite outgrowth in the CNS. Several brain CS–PGs, including phosphacan (DSD-1) and bikunin, contain embedded CS-D motifs within their CS side chains. Appican is the only brain PG identified, with embedded CS-E [51]. Appican is produced exclusively by astrocytes, which regulate neural cell adhesion and outgrowth. Appican also contains Alzheimer amyloid precursor protein (APP) as a core protein component, which is a Kunitz protease inhibitor/protease nexin 2 domain [50] with voltage-gated ion channel blocking properties relevant to neurite regulation [53]. The CS-E motif is essential for the interaction of the appican CS chain with growth/differentiation factors, and the regulation of neuronal cell adhesion, migration and neurite outgrowth.

nerve-glial antigen-2/CS–PG-4

CS–PG-4 (CSPG-4) (Figure 3a), also known as high molecular mass melanoma-associated antigen in humans and nerve-glial antigen-2 (NG2) in rodents, is a transmembrane CS–PG expressed by immature progenitor cells including oligodendrocyte, chondroblasts/osteoblasts, myofibroblasts, smooth muscle cells, pericytes, interfollicular epidermal and hair follicle cells [54,55]. CSPG4 is a single-pass type 1 transmembrane protein, occurring as a 250 kDa glycoprotein, a 450 kDa C4S–PG or can be non-glycanated [56,57]. The CS side chain of CSPG-4 facilitates interactions with α4β1 integrin and fibronectin, and has roles in the activation of proMMP2 by transmembrane MMPs. This ability to influence integrin and MMP activation implicates CSPG-4 in melanoma migration and invasion in skin [58,59]. CSPG-4 may participate in cell signalling as a co-receptor or by association with cytoplasmic kinases such as FAK or ERK-1, 2. CSPG-4 binds FGF-1 and PDGF AA and presents these to their cognate receptors to influence cellular proliferation and differentiation [60]. The central non-globular domain of CSPG-4 binds to collagen V and VI [61,62] facilitating cellular attachment and ECM stabilisation, and may induce cytoskeletal reorganisation conducive to cell spreading and migration [63,64]. In NG2 knockout mice, the epidermis is very thin due to reduced basal keratinocyte proliferation providing clues as to the likely role of this PG in skin development and homeostasis and insightful as to its possible roles in melanoma spread [54,57].

Thrombomodulin

Thrombomodulin (TM-β, CD141) is a multifunctional 74–105 kDa cell surface CS–PG mediator of endothelial anticoagulant activity, activator of protein-C and a thrombin receptor (Figure 3b). The presence of CS on TM-β decreases the Kd for thrombin binding and significantly accelerates thrombin inhibition [65,66]. The C-4-S chains on TM are relatively small (10–12 kDa) [67,68] but essential for its anticoagulant activities [69]. TM acts as an anticoagulant protein through its actions on thrombin and by participating in the generation of activated protein C (APC) [66]. Once APC is formed, it binds to protein-S on the cell surface and the APC–protein-S complex inactivates factors Va and VIIIa [7072]. TM's domain structure and multi-component interactions with thrombin, protein-C, thrombin-activatable fibrinolysis inhibitor, complement, LewisY antigen and HMGB1, a chromosomal protein which regulates transcriptional replication, facilitate TM's physiologically significant anti-inflammatory, anticoagulant and anti-fibrinolytic properties [73,74].

Phosphacan

Receptor-type protein tyrosine phosphatase beta (RPTP-β) is a transmembrane CS–PG expressed in the developing nervous system and contains an extracellular carbonic anhydrase (CAH) and fibronectin type III repeat domain, both of these domains foster protein–protein interactions. RPTP is expressed in three alternatively spliced forms RPTP-γ, RPTP-β/ζ, and a truncated form of RPTP-β with an 860 amino acid deletion (Figure 3c). Phosphacan is the proteolytically released ectodomain of the transmembrane protein tyrosine phosphatase receptor-ζ of neurons and glial cells [75] and is a principal CNS PG promoting neuron–glial interactions, neuronal differentiation, myelination and axonal repair. The transient nature of cell signalling by phosphorylation requires specific phosphatases for regulatory control. Phosphorylation of tyrosine residues in cellular proteins plays an important role in the control of cell growth and differentiation in the brain [7679]. The complexity of this regulatory system is evident in the spectrum and widespread distribution of spatially and temporally expressed protein tyrosine phosphatases. The CAH domain of RPTP-β/phosphacan promotes protein–protein recognition and induces cell adhesion and neurite outgrowth of primary neurons, and differentiation of neuroblastoma cells. The interaction of phosphacan with contactin may generate unidirectional or bidirectional signals which direct neural development and axonal repair [80].

The Syndecan family

The GAG side chains of the syndecan PGs provide subtle variation in their binding properties with ligands (Figure 3d). The core protein of the syndecans has a protease-sensitive site close to the transmembrane attachment region, and its cleavage results in the release of a soluble ectodomain form of these PGs. Although widely categorised as HS–PGs, syndecan-1, 3 and 4 can also be substituted with CS chains [81]. HS chains have an invariant structure between syndecan family members; however, their CS chains may contain non-sulphated, 4-O-, 6-O- and 4,6-O-disulfated N-acetylgalactosamine-CS-E. The CS chains of syndecan-4 generally display a greater overall sulphation level than those of syndecan-1 [82,83]. The HS and CS chains of syndecan-1 and -4 bind FGF-2, midkine (MK) and pleiotrophin (PTN). The HS and CS side chains of syndecan-4 are found localised with integrins in focal adhesions in fibroblasts, indicating that they have roles in cellular attachments and promote cellular migration [84] and may also influence cell signalling.

CD44

CD44 is the major HA receptor in the human body and is a ubiquitously distributed cell surface receptor (Figure 3e). CD44 can also occur as a part-time PG called epican, which is substituted with HS or CS chains. Epican is expressed by keratinocytes and mediates cell adhesive properties between keratinocytes in the epidermis [85,86].

Bikunin

Bikunin is a 30–39 kDa serum proteinase inhibitor synthesised in the liver and is a member of the inter-α-trypsin inhibitor (220 kDa) (ITI) and pre-α-trypsin inhibitor (125 kDa) (Pre-α-TI) families [87,88] (Figure 4a). A retrospective assessment of the Kunitz serine proteinase inhibitory proteins, present in ovine articular cartilage, meniscus and intervertebral disc (IVD), indicated that the 250, 120, 86, 58, 34–36 and 6–12 kDa SPIs in these tissues were related to ITI and pre-α-TI [89,90]. Bikunin's CS chains contain regions which are sulphated and non-sulphated, the sulphated regions contain embedded CS-D disaccharides [91]. The CS chain in bikunin is relatively small but heterogenous (8–25 kDa) [92,93]. Bikunin inhibits trypsin, thrombin, chymotrypsin, kallikrein, plasmin, elastase, cathepsins and Factors IXa, Xa, XIa, XIIa inhibitory activity and contains two 6 kDa Kunitz inhibitory domains. Bikunin counters inflammatory processes during many physiological processes and also has anti-tumour and antiviral and neuroregulatory activities.

Type IX collagen

Type IX collagen [94,95] contains a CS chain attached to the α2-chain of the type IX NC3 domain [9698] and is the PG-Lt PG isolated from chick embryonic tibia and femur [99] and chick embryo sternal cartilage [100,101] (Figure 4b). CS-substituted type IX collagen has also been isolated from chondrosarcoma [102], but is present as a minor glycanated form in articular cartilage [103]. The type IX collagen of chick vitreous humour contains an extraordinarily large CS chain of 350 kDa in size [104107]. The related type XII [108,109] and XIV collagen [110], which are basement membrane components, also bear CS chains and homology to type IX collagen.

Testican

The SPOCK gene encodes the protein core of a seminal plasma testican PG containing CS and HS chains (Figure 4c). This protein's function is unknown, although similarity to thyropin-type cysteine protease inhibitors suggests its function may be related to protease inhibition. Testican-1 inhibits cathepsin-L [111]. Testican-2 and -3 also regulate MMP activation at the cell surface abrogating MT1 MMP activity and proMMP-2 processing [112,113]. Testican is produced by endothelial cells [114] and has a widespread distribution; the brain is a particularly rich source of testican [115].

Serglycin

Serglycin is the only intracellular PG so far identified. Serglycin localises to the α-secretory granules of platelets and mast cells, where it binds and regulates the activity of platelet factor-4 in platelets or tryptase and chymase in mast cells [116119]. Serglycin is decorated with CS chains in the secretory granules of circulating basophils, but with heparin in resident tissue mast cells [116,120]. Mast cell serglycin displays a 2-B-6 (–) epitope on the CS chains which decorate this PG [121]. Trypstatin, the Kunitz protease inhibitor domain 2 of bikunin/ITI, is localised complexed with serine proteases in the α-granules of mast cells.

Colony-stimulating factor

Human monocytes secrete two CS–PG forms of colony-stimulating factor (CSF) containing two CS chains attached at the C-terminus of CSF-1 [122,123].

Leprecan

Leprecan is a basement membrane CS–PG; it contains an N-terminal leucine and a proline-rich domain, a C-terminal globular domain containing two CS chains and a 2-oxoglutarate-Fe-dependant dioxygenase and prolyl-3-hydroxylase enzymatic activity [124]. Prolyl hydroxylases 1–3 (PHD1–3) are oxygen-sensing enzymes which catalyse the hydroxylation of conserved prolyl residues in the HIF-1α subunit in normoxia targeting it for proteasomal degradation. HIF-1α and NF-κB are stabilised in hypoxia regulating a diverse range of ∼200 genes in erythropoiesis, angiogenesis, cardiovascular function, inflammation, apoptosis and cellular metabolism [125128].

Identification of neuroendocrine pro-hormones as CS–PGs

Many CS–DS pro-hormones have been identified using a proteomics screen involving isolation by anion exchange chromatography, pre-digestion of the isolated anionic proteins with chondroitinase ABC and identification of the CS linkage tetrasaccharide by mass spectrometry. Many of these pro-hormones are stored in intracellular granules in neuroendocrine cells. Granule proteins such as Chromogranin-A are processed into hormone peptides such as secretogranin-1, 2, 3, cholecystokinin or neuropeptide W.

Aggregated PG structures in cartilage and brain

Members of the hyalectan PG family, including aggrecan, brevican, neurocan and versican, form massive supramolecular perineural-net structures in the CNS (Figure 5a) through interactions with HA and tenascin-R. Perineural nets protect neurons from oxidative stress and mechanical damage, but also provide inhibitory signals preventing neural outgrowth. Aggrecan and versican also form massive supramolecular aggregate structures by interaction with HA and link protein in cartilage and fibrocartilaginous tissues (Figure 5b). These aggregated structures have impressive water regain properties equipping cartilage and IVD with the ability to withstand compressive forces.

CS sulphation motifs as molecular markers of tissue morphogenesis

During tissue morphogenesis, several PGs contain native 4-C-3, 7-D-4, 3-B-3[–] and 6-C-3 sulphation motifs (see Figure 1 for explanation). These native CS sulphation motifs are expressed in the surface regions of developing articular cartilages in the knee joint (Figure 6a,b) perichondrial growth plate, and in vascular ingrowth and stromal vascular niches of transitional tissues associated with diarthrodial joint and IVD development [129132]. Confocal colocalisation of the aforementioned CS sulphation motifs with aggrecan, versican and perlecan in neonatal cartilages has demonstrated that aggrecan and perlecan in these tissues bear these sulphation motifs, while versican does not [133]. Confocal studies in the human foetal elbow also demonstrated perlecan associated with perichondrial stem cell niches (Figure 7a) and with progenitor cell populations in the perichondrium (Figure 7c,g) and surface regions of the developing elbow joint cartilages (Figure 7c,h,i).

Distribution of CS epitopes and perlecan in foetal human knee.

Figure 6.
Distribution of CS epitopes and perlecan in foetal human knee.

Confocal immunolocalisation of the 4C3 (a) and 7D4 (b) native CS sulphation motifs and perlecan using anti-domain IV antibody A7L6 (c) in human foetal (14-week gestational age) knee tibial cartilage. Cell nuclei are stained red with propidium iodide in (a) and (b) and with DAPI in (c). The primary antibody localisations were stained green using FITC-conjugated anti-mouse or rat IgG. Perlecan identifies stem cell niches in the surface regions of the developing cartilage. Figure modified from ref. [130].

Figure 6.
Distribution of CS epitopes and perlecan in foetal human knee.

Confocal immunolocalisation of the 4C3 (a) and 7D4 (b) native CS sulphation motifs and perlecan using anti-domain IV antibody A7L6 (c) in human foetal (14-week gestational age) knee tibial cartilage. Cell nuclei are stained red with propidium iodide in (a) and (b) and with DAPI in (c). The primary antibody localisations were stained green using FITC-conjugated anti-mouse or rat IgG. Perlecan identifies stem cell niches in the surface regions of the developing cartilage. Figure modified from ref. [130].

Distribution of native CS epitopes and perlecan in foetal elbow cartilage.

Figure 7.
Distribution of native CS epitopes and perlecan in foetal elbow cartilage.

Perlecan and 4C3/7D4 immunolocate the perichondrial stem cell niche and activated progenitor cells involved in foetal elbow joint development. Immunolocalisation of perlecan and the CS sulphation motifs 4C3 and 7D4 using indirect fluorescent confocal microscopy of human foetal elbow (14-week gestational age). Perlecan is immunolocalised to the outer layers of the perichondrium (a, b), while the 7D4 (ce) and 4C3 CS sulphation motifs (fi) are located on cell-associated PGs deeper in the elbow cartilage rudiment and in the surface regions of the interzone cartilage of the developing elbow joint (fi).

Figure 7.
Distribution of native CS epitopes and perlecan in foetal elbow cartilage.

Perlecan and 4C3/7D4 immunolocate the perichondrial stem cell niche and activated progenitor cells involved in foetal elbow joint development. Immunolocalisation of perlecan and the CS sulphation motifs 4C3 and 7D4 using indirect fluorescent confocal microscopy of human foetal elbow (14-week gestational age). Perlecan is immunolocalised to the outer layers of the perichondrium (a, b), while the 7D4 (ce) and 4C3 CS sulphation motifs (fi) are located on cell-associated PGs deeper in the elbow cartilage rudiment and in the surface regions of the interzone cartilage of the developing elbow joint (fi).

Cartilage PGs containing CS sulphation motifs with roles in tissue development

Aggrecan is the major CS–PG of cartilaginous tissues, with well-known space-filling and water-imbibing properties that equip these tissues with resilience to compressive loading. Correct sulphation of CS–PGs is essential for proper Indian hedgehog signalling in the developing growth plate [134]; perlecan, a hybrid CS–HS PG, in the cartilage is also responsible for the localisation and activity of the related Sonic hedgehog protein [135]. Native CS sulphation motifs such as 7-D-4 on PGs may serve to immobilise growth factors/morphogens actively involved in tissue development [17]. The unique distributions of native CS motifs, such as 7-D-4 with surface zone progenitor cells in articular cartilage [132,136,137] and within the developmental IVD [129] and human foetal elbow [130], are suggestive of an early stage of progenitor cell differentiation and indicate that native CS sulphation motifs have functional roles in chondrogenesis and in IVD development [129,136,137].

Focal expression of the 7-D-4 CS sulphation motif in human foetal paraspinal blood vessels

Perlecan produced by endothelial and smooth muscle cells is a prominent component of capillaries and larger blood vessels (Figure 8a,b). The 7-D-4 CS sulphation motif displays a focal distribution in the lumenal surfaces of capillaries and between the endothelial cells lining human foetal paraspinal blood vessels (Figure 8b). Pericytes are contractile cells that wrap around the abluminal surface of endothelial cells that line the capillaries and venules throughout the body (Figure 8d–g). Caplan proposed that all stem cells were pericytes emphasising their vascular origins [138141]. Pericytes are embedded in the basement membrane where they communicate with endothelial cells of the body's smallest blood vessels by means of both direct physical contact and paracrine signalling [142145]. Blood flow-generated shear forces are also important functional determinants of the differentiation of stem cells in the luminal surfaces of blood vessels [8,146].

Distribution of the 7-D-4 native CS epitope and perlecan and associated vascular components in paraspinal human foetal blood vessels.

Figure 8.
Distribution of the 7-D-4 native CS epitope and perlecan and associated vascular components in paraspinal human foetal blood vessels.

Focal expression of perlecan (a) and 7-D-4 CS sulphation motif (b) in foetal human paraspinal blood vessels. Perlecan is a well-known vascular HS–PG, produced by endothelial cells. The 7-D-4 CS sulphation motif is focally expressed in the lumenal surfaces of these small blood vessels (b) and may provide evidence of a vascular progenitor cell population directed by signals from pericytes on the abluminal surfaces of these vessels (c). Diagram of a small capillary showing the relationship of the endothelial cells and pericytes (d and e). Type IV collagen delineates the blood vessel the pericyte resides on (f), while NG2 PG is a pericyte marker (g).

Figure 8.
Distribution of the 7-D-4 native CS epitope and perlecan and associated vascular components in paraspinal human foetal blood vessels.

Focal expression of perlecan (a) and 7-D-4 CS sulphation motif (b) in foetal human paraspinal blood vessels. Perlecan is a well-known vascular HS–PG, produced by endothelial cells. The 7-D-4 CS sulphation motif is focally expressed in the lumenal surfaces of these small blood vessels (b) and may provide evidence of a vascular progenitor cell population directed by signals from pericytes on the abluminal surfaces of these vessels (c). Diagram of a small capillary showing the relationship of the endothelial cells and pericytes (d and e). Type IV collagen delineates the blood vessel the pericyte resides on (f), while NG2 PG is a pericyte marker (g).

The tissue distribution and function of oversulphated CS isomers CS-D and CS-E

Developmental studies on the whole rat brain have correlated changes in the CS side chain structure of phosphacan with measurable changes in the binding affinity of PTN and functional consequences on the cell signalling response. Phosphacan isolated from the whole rat brain from various developmental stages was examined using the CS antibodies MO225, CS56 and 2H6 in a plasmon resonance study [147]. P7 phosphacan strongly reacted with CS56 and 2H6 but not with MO225. P12 phosphacan showed moderate reactivity with CS56 and 2H6 but no reactivity with MO225 contrasting with P20 phosphacan which was strongly reactive with MO225 but low reactivity with CS56 and 2H6. mAb 2H6 is sold as an anti-CS-A Ab due to its high reactivity with whale cartilage CS-A; however, its reactivity with phosphacan of a defined CS-A content does not correlate with this. P7 phosphacan with a CS-A content of 64% had the highest reactivity with mAb 2H6, while P20 phosphacan with a CS-A content of 86% had very low reactivity. This showed that the 2H6 epitope was not to a simple CS-A unit but to a more extended binding epitope. Subsequent studies have shown that mAb CS-56 and MO-225 specifically recognise octasaccharides containing an A–D tetrasaccharide sequence, whereas 2H6 preferred sequences with A- and C-units such as C–C–A–C for strong binding but no D-unit, mAb MO225 also recognised the CS-E disaccharide motif from squid cartilage in an extended E-E-E-E-C binding motif [148,149]. The development of CS oligosaccharide libraries [150] of defined structure has further enhanced the precision of such structure–function studies. These show that the CS motifs are differentially regulated in brain development and modulation in CS structure occurs in a spatiotemporal manner.

Cell regulatory PGs are involved in neural development and repair

Oversulphated CS/DS promotes neural development with variation in sulphation profiles of PGs regulating vertebrate CNS development. The disulphated disaccharide D-unit promotes neurite outgrowth through the DSD-1 epitope embedded in the CS chains of DSD-1–PG/phosphacan [150155]. Oversulphated DS displays neurite outgrowth activity [156]. The short isoform, non-PG variant form of phosphacan/receptor protein tyrosine phosphatase-β also interacts with neuronal receptors and promotes neurite outgrowth [80]. Bikunin is also expressed in the brain tissue [157,158] and accumulates in brain tumours [159]. Like phosphacan, bikunin contains disulphated embedded CS-D motifs within the repeating disaccharide region of its CS chain [91]. Such motifs promote neurite outgrowth, suggesting that bikunin may also have similar roles to play in neural development. Appican is another brain CS–PG [50,160] produced by astrocytes [161], which direct neural development. CS-E motifs embedded within the CS chains of appican [51] interact with neuroregulatory factors [52] inducing morphological change in C6 glioma cells and directed adhesion of neural cells to the ECM [53]. CS-E motifs also promote chondrocytic differentiation of ATDC5 cells. ATDC5 cells produce monosulphated CS-A or disulphated disaccharides (CS-E) in their ECM PGs. Exogenously added CS-E also affect chondrogenic differentiation of ATDC5 cells, promoting chondrogenic differentiation demonstrating the existence of cell surface receptors for CS-E [162]. Embedded CS-E in the CS side chains of growth plate perlecan also promotes collagen fibrillogenesis [49].

NG2 PG, phosphacan and syndecan-1–4 have roles in cellular regulation and tissue development, which may be applied in tissue repair strategies. For example, NG2 PG stimulates endothelial cell proliferation and promotes migration during micro-vascular morphogenesis. NG2 is also expressed by chondroblasts and chondrocytes, and acts as a cell surface α2-VI collagen receptor conferring cellular motility and α4β1 integrin-mediated cell spreading by activation of FAK and ERK1/ERK2 signalling cascades. A better understanding of the CS sulphation motifs and their binding partners and how these regulate cellular processes in tissue remodelling and repair may allow the development of improved therapeutic procedures in repair biology.

The balance between stimulatory and inhibitory signals in neural development

SRPX2 (Sushi repeat protein, X-linked 2) (Figure 2a) is a novel secreted CS–PG, which promotes synaptogenesis in the cerebral cortex and it is found as an embedded domain in some members of the lectican PG family. The SPRX2 gene is a target of the foxhead box protein P2 transcription factor (FoxP2) that modulates synapse formation [163]. Mutations in SRPX2 cause Rolandic epilepsy and speech impairment (RESDX syndrome). Interactome/cell surface-binding/plasmon resonance studies have identified SRPX2 as a ligand for uPAR, the urokinase type plasminogen activator (uPA) receptor [164]. uPAR knockout mice exhibit an enhanced susceptibility to epileptic seizures and anomalous cortical organisation consistent with altered neuronal migration during brain development [165,166]. uPAR is a crucial component of the extracellular plasminogen–plasmin system, which remodels the ECM during brain development. Cathepsin B and ADAMTS4 are also SRPX2 ligands and also likely participants in developmental processes in the brain [167]. ADAMTS-4 has been localised to regions of the spinal cord undergoing repair. ADAMTS-4 degrades aggrecan and versican in the CNS, thus removing the inhibitory signals provided by the CS side chains of these PGs [168,169].

Cathepsin B is a well-known activator of pro uPA; thus, SRPX2 and its ligands represent a network of proteins with critical roles in brain development and specifically in the centres of speech and cognitive learning. The Rolandic and Sylvian fissures bisect the human cerebral hemispheres and it is the adjacent areas of the brain, which are responsible for speech processing. Ordered neuronal migration is therefore essential for the correct development of these areas of the brain. SRPX2 protein expression occurs in neurons from birth and has central roles to play in developmental processes in the centres of speech and cognitive learning. Two mutations have been identified in SRPX2 in RESDX patients. One mutation (N327S) results in altered glycosylation, while a second mutation (Y72S) affects the first sushi domain of SRPX2 [170], 3D modelling indicates that the Y72S mutation affects an area of the SRPX2 core protein normally involved in protein–protein interactions [171]. Cultured cells from RESDX patients display alterations in the intracellular processing of proteins and likely misfolding which may have functional consequences [172].

Specific CS sulphation motifs are involved in interactions between neurons and glial cells to regulate the development and regeneration of the CNS. Migrating neurons are guided by glial cells through ECM PGs they assemble such as phosphacan, and the CS–lectican PG family. Phosphacan promotes neurite outgrowth, whereas versican, neurocan and brevican inhibit this process thus collectively these PGs direct neurite growth. This is a function of their differing GAG CS sulphation motifs. CS-D motifs in phosphacan promote neurite outgrowth, while lectican CS-A and CS-C motifs inhibit neuronal migration [152] and regulate neural tissue morphogenesis [150,153,173]. Glucuronyltransferase-1 knockout ESCs lack CS resulting in a significantly altered ability to differentiate and reduced ability to develop into pluripotent cell lineages [26]. HS maintains ESCs in a state primed for differentiation; however, CS maintains ESC pluripotency and promotes ESC differentiation. Binding of CS-A and CS-E to E-cadherin to overcome cell inhibitory signals enhances ESC differentiation [26]. The highly charged CS-D and CS-E sulphate motifs can mimic HS in terms of growth factor and cytokine binding; however, the less highly charged CS-A and CS-C isomers should not be discounted in such interactions. Surface plasmon resonance studies have demonstrated that CS-A and CS-C bind with significant affinity to MK, PTN, HGF and stromal cell-derived factor-1β but with a lower affinity than CS-D, CS-E and HS [174] regulating the growth, differentiation and migration of neural precursor cells [175]. Such lower affinity interactions may provide a more subtle control mechanism than the strong on-off signals supplied by HS. FGF-2 and EGF-dependent proliferation of glial cells regulates neurogenesis during CNS development [176178]. Chondroitin-6-sulphate synthesis is up-regulated in the injured CNS, induced by injury-related cytokines and enhanced in axon-growth inhibitory glia [179] and of relevance to nerve regeneration through glial scar formations [180].

CS sulphation motifs and pathological remodelling of connective tissues

Several years ago [181,182], it was noted that mAbs 3-B-3 (–) and 7-D-4 identified chondrocyte ‘cell clusters’ in pathological (osteoarthritic) canine and human articular cartilage and at that time these were considered a classical feature of the onset of late-stage degenerative joint disease. In these early publications, a lack of knowledge of stem/progenitor cells in cartilage and expression of PGs (aggrecan) with CS GAG chains recognised by mAbs 3-B-3 (–) and 7-D-4 were interpreted to indicate a failed, late-stage, attempt to repair cartilage and replacement of new PGs in a matrix that had been extensively degraded by MMPs. An alternative hypothesis now is that these ‘chondrocyte clusters’ arose from adult stem/progenitor cells in these tissues [183]. Tesche and Miosge [184,185] showed that adult stem cell clusters were surrounded by a pericellular matrix containing perlecan. This is also a feature of stem cell niches in foetal knee, hip, IVD and elbow cartilage [129133,186]. It is expected that in different connective tissues, the CS sulphation motifs will be present on different matrix and cell surface PGs; if this is the case, an important feature of the stem/progenitor cell niche may be the sulphation of the GAGs rather than the core proteins to which they are attached. Expression of different levels of GAG sulphotransferases in stem/progenitor cells would therefore also contribute to tissue repair [187189]. More recently, cell clusters within the superficial zone of healthy articular cartilage have been shown positive for both Notch 1 and CD166 [190], cell surface markers that are synonymous with the stem cell niche environment [136,191].

CS expression and tumour development

Neuroendocrine tumours with different degrees of histological differentiation have correlative alterations in associated CS but little change in HS. Normal stroma contains no staining with anti-CS Abs while staining in tumour is significantly elevated and highest in advanced tumour grades [192]. CS–PG levels are elevated in liver cancer [193], renal [194], hepatocellular [195,196] and gastric carcinoma [197], pancreatic cancer [198] and in mammary tumours [199]. In gastric and pancreatic cancer, non-sulphated and 6-sulphated CS predominate over other GAG isoforms and the GAG chains display a smaller hydrodynamic size than normal tissues. Elevated levels of 4- and 6-sulphated CS are found in renal cancer. Decorin and versican levels are elevated 7- to 27-fold in pancreatic cancer, and contain non-sulphated and 6-sulphated CS. This contrasts with the normal pancreas where DS is the predominant GAG decorating versican and decorin core proteins. Tumour PGs have altered interactive properties further impairing the normal functional properties of tumour-affected tissues. PGs and GAGs modulate cellular processes relevant to all stages of tumour progression, including cell proliferation, cell–matrix interaction, cell motility and invasive growth. HS, CS/DS and HA all have well-documented roles in tumour pathobiology [200]. CS is abundantly present in the ECM in ovarian cancer. Alterations in the sulphation of CS also influence cancer development and its aggressive status. The CHST15 gene is responsible for the biosynthesis of highly sulphated CS-E. The single-chain phage Ab GD3A11 to highly sulphated CS facilitates identification of biomarkers in aggressive tumour development. The GD3A11 epitope is minimally expressed in normal tissues, but is intensely expressed in many ovarian cancer subtypes but not in benign ovarian tumours [201]. Serum oversulphated CS levels measured using mAb WF-6 are also elevated in ovarian cancer and may also be a useful biomarker [202]. Silencing of CHST15 in vitro and in a xenograft model of pancreatic cancer down-regulates tumour invasion in pancreatic ductal adenocarcinoma (PDAC). CS-E is detected in both tumour and stromal cells in PDAC and is considered to have multistage involvement in its development [203]. A single intratumoural injection of CHST15 siRNA almost completely silenced tumour growth providing evidence of the direct involvement of CHST15 in the proliferation of pancreatic tumour cells identifying a novel therapeutic target. The phage display antibody GD3G7 also reacts with the rare CS-E and DS-E epitopes in normal tissues, where DS-E epitope represents IdoUA-GalNAc (4,6-O-disulphate) [368]. CS-E is strongly up-regulated in ovarian adenocarcinomas. Thus, Ab GD3G7 is useful in defining tumour tissue alterations [204]. Quantitation of GAGs in colorectal tumour tissue using electrospray ionisation mass spectrometry showed that neoplastic tissues displayed greater levels of CS and DS than non-neoplastic tissue where HS was decreased [205]. NEDD9 (CAS-L, HEF-1) cells have key roles in the migration and proliferation of MDA-MB-231 breast cancer cells [206]. Microarray studies in breast cancer samples demonstrate elevated CD44 and serglycin and down-regulation of syndecan-1, syndecan-2 and versican, whereas CHST11, CHST15 and CSGALNACT1 were all up-regulated in NEDD9 cells, an increase in CS-E attached to CD-44 was also evident in tumour cells. Removal of CS using chondroitinase ABC inhibited colony formation by NEDD9 cells, whereas exogenous application of CS-E enhanced NEDD9 cell proliferation and tumour development clearly demonstrating roles for CS-E in tumorigenesis [206]. Many tumour cells express GAGs with alterations in sulphation level. Altered expression of CS and HS on tumour cells has a key role to play in malignant transformation and tumour metastasis [207,208]. Receptor for Advanced Glycation End products (RAGE) is a receptor for CS-E in Lewis lung carcinoma (LLC) cells [273,278]. RAGE binds strongly to CS-E and HS and to LLC cells, and has roles in tumour development. Serglycin is the major PG produced by multiple myeloma (MM) cells. Knockdown of serglycin dramatically attenuated MM tumour growth [209]. Tumours, which develop in serglycin knockdown animals, display lower levels of HGF and reduced blood vessel development, indicating that serglycin has roles in angiogenesis. The CS chains on serglycin are at least partly responsible for cellular attachment to CD44. Serglycin was originally considered to be a product of haematopoietic cells, and recent studies have shown that it is also synthesised by many non-haematopoietic cells [210]. Serglycin is expressed by tumour cells, promotes an aggressive phenotype and confers resistance to drugs and inactivation by the complement system. Serglycin promotes inflammatory conditions through inflammatory mediators, which are normally complexed in intracellular granules, thereby contributing to tumour development. The CS–lectican PG versican accumulates in the tumour stroma and has key roles in malignant transformation and tumour progression. Elevated expression of versican in malignant tumours is associated with cancer relapse and poor clinical outcome in prostate, breast and many other cancer types. Versican (so named from ‘versatile’) regulates cell adhesion, proliferation, apoptosis, migration, angiogenesis, cell invasion and metastasis. These processes involve interactions mediated by the CS and DS chains of versican and its G1 and G3 globular domains. Versican therefore represents a logical therapeutic target in tumour pathobiology [211]. Versican G3 domain regulates neurite growth [212]. Versican Vo and V1 regulate neural crest cell migration [213]. Versican G3 domain promotes tumour growth and angiogenesis [214,215].

CD44 regulates apoptosis in chronic lymphocytic leukaemia (CLL) and its expression is mediated by the tumour microenvironment. The interaction of CD44 with HA and CS protects CLL cells from apoptosis. Specific antibodies to CD44 (IM7, A3D8) impair the viability of CLL cells and represent a potential therapeutic target [216]. CS chains in the microenvironment of breast cancer cells have been suggested as appropriate molecular therapeutic targets, given that they promote many aspects of carcinogenesis in vitro [217]. Dramatically elevated CS levels have been observed in the stromal microenvironment of many solid tumours. Intratumoural injection of chondroitinase ABC was ineffective in promoting primary tumour regression, but led to the development of secondary tumours indicating that the CS chains associated with primary tumours had a metastasis inhibitory role exploitable in therapeutic interventions. Cell surface HS and CS chains have roles in the infective stages of viral-mediated carcinomas such as Merkel cell carcinoma, a highly lethal but rare form of skin cancer. HS and CS chains act as cellular receptors in the infective stages of Merkel cell polyomavirus. Modulation or removal of such CS or HS entry points may provide an approach to combat viral attachment to cells during these initial infective stages [218]. CS on the surface of breast cancer cells functions as P-selectin ligands. CHST11 and CSPG4 are highly expressed in aggressive breast cancer cell lines and correlate with P-selectin-binding levels. The CS chains of CSPG4 facilitate binding of P-selectin to highly metastatic breast cancer cell lines. Targeting of CS and its biosynthesis represents an attractive approach in anti-metastatic therapy [219,220]. Therapeutic targeting of CSPG4 has been used to specifically target myeloma tumour cells using mAb-based therapies [58,221]. Adoptive transfer of genetically modified T-cells is emerging as a powerful anti-cancer biotherapeutic. CSPG4 is an attractive target molecule in this approach due to its high expression in cancer cells in several types of human malignancies but restricted distribution in normal tissues [222] and helps to minimise any potential toxic side effects using such approaches. T-cells expressing a CSPG4-specific chimeric antigen receptor offer the possibility of targeting a broad spectrum of solid tumours for which no curative treatment is currently available [222224]. The treatment of rhabdomyosarcoma (RMS) remains particularly challenging, with metastatic and alveolar RMS offering a particularly poor prognosis. CSPG4 is specifically expressed on RMS cells. The immunotoxin αMCSP-ETA specifically recognises CSPG4 on the RMS cell lines RD, FL-OH1, TE-671 and Rh30 and is internalised rapidly, induces apoptosis and kills RMS cells selectively. Preliminary studies have demonstrated promising results with the specific binding of this immunotoxin to RMS primary tumours [225]. Deterioration of liver function in liver cancer is accompanied by an increase in the amount of CS–PGs. This alteration in PG composition interferes with the physiologic function of the liver. Glypicans, agrin and versican also play significant roles in the development of liver cancer [193]. CS–PGs have essential roles to play in tissue morphogenesis and in cancer development involving interactions with growth factors, morphogens, cytokines, cell surface receptors and many matrix proteins [226].

GAGs play vital roles in every step of tumour progression. Tumour samples with different degrees of histological differentiation demonstrate important alterations in the CS chains of many PGs. Immunolocalisations conducted with anti-CS antibodies consistently showed that normal stroma was negative, whereas tumoural stroma was positive with elevated staining in the higher grade cancer samples while the tumour cells themselves were negative. Syndecan-2 levels were low or undetectable in normal tissues, but significantly elevated in endocrine tumours. Glypican-5 was overexpressed in high-grade tumours with epithelial differentiation, but not in neuroendocrine tumours. Normal neuroendocrine cells displayed positive cytoplasmic and membrane staining for glypican-1, but elevated expression in low-grade tumours and reduced in high-grade tumours [192]. The use of a therapeutic CSPG4-specific antibody (225.28) enhanced and prolonged the inhibitory response of PLX4032 (Vemurafenib) in combination therapy, suggesting that Ab 225.28 may be useful as a delivery system in the treatment of melanoma [227].

CS sulphation motifs regulate cell behaviour — can they be used to promote tissue repair?

This review has demonstrated pivotal roles for CS–PGs in developmental processes in cell migration, cellular recognition and tissue morphogenesis [14]. Novel CS sulphation sequences also occur in the functionally distinct layers of skin [228]; they are associated with the long bone growth plates in endochondral ossification and occur at important growth zones in the developing IVD, diarthrodial joints and tendon [229,230]. During lymphopoiesis, CS chains are also differentially modified at sites of B-cell differentiation and maturation [229,231], and in the brain, CS sulphation plays an important role in neurite outgrowth, synaptic plasticity and neurological development [232]. Accumulated evidence therefore points to specific GAG sequences in CS having roles in cell interactions and developmental processes. A greater understanding of these processes through sustained basic research could eventually lead to their use in advanced therapeutic applications in regenerative medicine. With the advances in oligosaccharide synthesis methodology now available, the CS sulphation motifs discussed in this review can be synthesised and CS oligosaccharide microarrays prepared to answer structure–function questions relevant in tissue repair strategies. Many lipid-derivatised CS oligosaccharides with well-defined sulphation features have been synthesised and used in CS oligosaccharide microarrays to characterise the preferred binding sequences of the anti-CS mAbs 2H6, MO225, 473HD and LY111 [167] and to assess prospective binding partners (growth factors, cytokines), and many of the effects of these CS oligosaccharides on cellular behaviour have also been determined in vitro. This supports their therapeutic application in tissues such as the brain and CNS, and may lead to the re-establishment of nerve function in glial scar formations.

Development of smart CS bioscaffolds to improve tissue repair

The development of CS bioscaffolds and their applications with stem cells in cartilage, bone, cornea, skin and nerve repair strategies represent a significant advance in bioscaffold design and performance in tissue repair strategies. CS has indispensable roles to play in stem cell differentiation and attainment of pluripotency [26]. Accumulated evidence points to CS sulphation motifs having critical roles in cell interactions, cell differentiation, proliferation and matrix assembly. A greater understanding of these glyco-code-mediated processes could lead to improved repair biology therapeutics. Cartilage is a particularly difficult tissue to repair and many biomatrices have been developed in order to perfect an effective repair strategy [233], these have focussed on MSCs as a therapeutic cell type. CS bioscaffolds promote proliferation of bone marrow stromal MSCs and their differentiation to a chondrogenic phenotype appropriate for cartilage repair. Combinations of CS, gelatin, chitosan, HA incorporated into polyvinyl alcohol and polylactic-co-glycolic acid (PLGA) hydrogels [233237] have been developed. A thermoresponsive photopolymerizable CS hydrogel has been used to prepare a chondrocyte matrix suitable for 3D printing [234]. CS tethered on silk fibroin, silk–gelatin–CS–HA biocomposites or CS biomimetic scaffolds [238] have proved suitable for induction of a chondrogenic phenotype in MSCs [239,240]. Porous CS–alginate foams and chitosan–gelatin–C6S–HA cryogels promote the chondrogenic differentiation of MSCs [241243] as do CS–HA–silk–lentiviral inserted TGF-β3 gene, HA–CS–heparin–collagen scaffolds and multilayered 3D CS chitosan constructs [244246]. Atelocollagen–CS, collagen–CS–HA 3D hydrogels, cross-linked type II collagen–CS scaffolds [247249], PLGA–gelatin–CS–HA–TGF-β3 and elastic copolymer–CS–TGF-β3 scaffolds provide superior induction of chondrogenic cells from seeded MSCs [250,251].

Fibrous tissue formed in response to implanted materials has been shown to contain CS [252], with increased infiltration of inflammatory mast cells. The mast cell PGs serglycin and perlecan display a 2-B-6 (−) epitope on their CS chains [121]. Like 3-B-3 (−), 2-B-6 (−) is not generated by chondroitinase ABC digestion. The presence of this 2-B-6 (−) epitope has previously been reported in osteoarthritic cartilage; however, the generation and function of the epitope remain to be established [253]. The generation of this epitope is due to the action of a member of the hyaluronidase (HYAL) family, HYAL-1 or HYAL-4, depolymerises CS via a hydrolytic cleavage reaction at the β1 → 4 disaccharide glycosidic linkage [254,255]. HYAL-1 or HYAL-4 may also generate the 3-B-3 (−) ‘native’ CS epitope. The 2-B-6 (−) epitope and the HYAL-4, produced by mast cells, are both associated with tissue remodelling and repair in inflammatory conditions.

Cell surface CS receptors and CS-interactive molecules that control cellular behaviour

Only a few cell interactive oligosaccharide sequences in CS–DS have so far been identified due to inherent difficulties in decoding their complicated structures. CS–DS hexasaccharide and octasaccharide motifs, which facilitate interactions with heparin cofactor-II and PTN, have been determined [256258]. A major difficulty in the identification of these interactive CS–DS modules is that they do not have a well-defined saccharide sequence, but rather several heterogeneous modification patterns, the so-called wobble CS–DS motifs [25]. The nomenclature for CS isoforms, CS-A, CS-C, CS-D, CS-E and DS, is confusing and misleading in that naturally occurring CS-A, for example, is not a homogenous polymer composed of CS-A disaccharide units only, but may contain a mixture of A, C and unsulphated chondroitin units, and embedded CS-D or CS-E motifs within the repeating disaccharide regions of CS-A GAG chains or the d-glucuronic acid can be epimerised to l-iduronic acid [259,260]. HS has historically been considered to play more important roles in GAG-mediated cellular regulation than CS due to its higher propensity to interact with growth factors, morphogens and ECM components [261]. Recent studies have now demonstrated essential roles for CS–DS in many biological processes, especially in events, which regulate CNS development, and in tumorigenesis/metastasis.

The soluble ectodomain of PTPR β/ζ phosphacan interacts with the cell surface receptor contactin-1 (Figure 9a). Further cell signalling membrane proteins include the syndecan PG family (SDC 1–4), CSPG-4, betaglycan or endoglycan, and these interact with cell surface receptors such as neuropilin-1, leucocyte common antigen-related phosphatase (LAR) and the related receptor protein tyrosine phosphatase β/ζ (Figure 9b,c). The neuronal Nogo axonal guidance receptor family consists of three GPI-anchored receptors (NgR1, R2 and R3) (Figure 9d,e) [262]; the semaphorins and neuropilins are further receptors which interact with CS ligands (Figure 9f,g). P75 is a transmembrane co-receptor which interacts with many receptors including the Nogo-1 receptor (NgR1) and acts as a signal transducer, converting signals initiated upon binding of myelin-associated inhibitory proteins or CS–DS GAG to NgR1 converting this into intracellular signals via p75's cytoplasmic domains and the Ras/MAPK and JNK pathways to inhibit neurite outgrowth.

Cell surface CS interactive molecules with roles in nerve development.

Figure 9.
Cell surface CS interactive molecules with roles in nerve development.

Neuronal cell CS-interactive surface molecules with regulatory roles in neuronal development. Contactin-1 (a), LAR tyrosine phosphatase receptor (b), protein tyrosine phosphatase receptors (PTP-σ and PTP-ζ) (c), Nogo receptor-1 and 3 (NgR1 and NgR3) (d, e), semaphorin-5A (Sem 5A) (f) and neuropilin-1 (NRP-1) (g).

Figure 9.
Cell surface CS interactive molecules with roles in nerve development.

Neuronal cell CS-interactive surface molecules with regulatory roles in neuronal development. Contactin-1 (a), LAR tyrosine phosphatase receptor (b), protein tyrosine phosphatase receptors (PTP-σ and PTP-ζ) (c), Nogo receptor-1 and 3 (NgR1 and NgR3) (d, e), semaphorin-5A (Sem 5A) (f) and neuropilin-1 (NRP-1) (g).

E-Cadherin

The cadherins are calcium-dependent type-1 transmembrane proteins, which form adherens junctions, binding cells tightly together within tissues, and have essential roles to play during embryonic development and critical in the induction of stem cell pluripotency [263266]. Cell adhesion is mediated by extracellular cadherin domains, and intracellular cytoplasmic domains associate with a large number of adaptor and cytoskeletal signalling proteins that constitute the cadherin adhesome [267]. The cadherin membrane-spanning adherens junction proteins have crucial roles in cell–cell contact formation and are also connected to cytoplasmic proteins that regulate signalling pathways and relay information regarding cell interactions to the nucleus [268272]. E-cadherin and LRP 5/6 interact cooperatively with cell surface CSPGs and they are frizzled to regulate intracellular signalling through effects mediated by the catenin system which affects actin polymerisation/depolymerisation regulating ERK phosphorylation and cell signalling (Figure 10a,b). CS–DS contributes to several signalling pathways and biological events [273]. A CS-E isoform binds strongly to Wingless/int-3a (Wnt-3a) and to many growth factors, neurotrophic factors and cytokines in vitro [274276] (Figure 10c). Wnt signalling controls many developmental processes, tissue renewal and regeneration, and the development of several diseases, particularly cancers [274276]. Specific arrangement of sulphation motifs on CS–DS chains modulates Wnt signalling and diffusion. Early stages of ESC differentiation are promoted or repressed by CS-E, but not by CS-A through Wnt/β-catenin signalling pathways [275]. The migration of breast cancer cells in vitro is reduced by CS-E, but not by CS–DS [276]. CS-E regulates type I collagen fibrillogenesis and expression, and is a positive regulator of breast carcinoma, through Wnt signalling [276]. Collectively, these findings provide insights into how cancer development is mediated through CS-E and Wnt/β-catenin signalling. However, it is still unclear what specific sulphation pattern(s) or length of CS-E saccharide is required to activate and regulate such development processes.

CS-interactive cell surface molecules with roles in cytoskeletal organisation and cell regulation.

Figure 10.
CS-interactive cell surface molecules with roles in cytoskeletal organisation and cell regulation.

CS-interactive properties of E-cadherin (a), syndecan PG family (b) and the frizzled LRP-5/6 co-receptor complex (c) and resultant effects on cytoskeletal reorganisation and gene regulation.

Figure 10.
CS-interactive cell surface molecules with roles in cytoskeletal organisation and cell regulation.

CS-interactive properties of E-cadherin (a), syndecan PG family (b) and the frizzled LRP-5/6 co-receptor complex (c) and resultant effects on cytoskeletal reorganisation and gene regulation.

CS-E interactions with RAGE involved in tumour metastasis

The biosynthesis of stromal CS–DS PGs is up-regulated in many tumours causing their accumulation in stromal tissues with attendant effects on tumour progression [277,278]. The proportion of CS-E disaccharide units in CS–DS chains is elevated in ovarian and pancreatic cancers [212,275], resulting in alterations in neoplastic growth and cell motility. Tumour cell signalling is also controlled by VEGF and cleavage of CD44 [279,280]. The stronger expression of disulphated CS-E disaccharide units on CS–DS chains on the surface of metastatic LLC cells correlates with their invasive properties in the lung tissue [281]. In the lung, RAGE acts as a receptor for cell surface CS–DS chains containing CS-E units expressed by LLC cells [282] (Figure 11a,b). RAGE recognises CS-E unit containing decasaccharides [282], these markedly inhibit the pulmonary metastasis of LLC cells [281], most probably by competitive inhibition. Binding of CS–DS ligands to RAGE leads to downline effects on intracellular proteins, such as Rap1 and PKC, which affect the activation of NF-κB and CREB signalling and transcriptional regulation (Figure 11c).

Interactive components of the RAGE CS cellular receptor and effects of ligand binding on associated cytoskeletal components and how they effect transcriptional regulation of cells.

Figure 11.
Interactive components of the RAGE CS cellular receptor and effects of ligand binding on associated cytoskeletal components and how they effect transcriptional regulation of cells.

Interactive properties of CS–DS GAG chains of PGs (a), HMBG1, AGEs, S100 proteins and amyloid peptides with the extracellular domains of the RAGE receptor and effects on cytoskeletal proteins (b), activation of NF-κB and CREB transcriptional regulation (c).

Figure 11.
Interactive components of the RAGE CS cellular receptor and effects of ligand binding on associated cytoskeletal components and how they effect transcriptional regulation of cells.

Interactive properties of CS–DS GAG chains of PGs (a), HMBG1, AGEs, S100 proteins and amyloid peptides with the extracellular domains of the RAGE receptor and effects on cytoskeletal proteins (b), activation of NF-κB and CREB transcriptional regulation (c).

Conclusions

While advances in detection methodologies continue to improve the characterisation of an ever-expanding repertoire of complex glycans in small amounts of sample, certain unifying principles have emerged with regard to how these entities regulate cellular metabolism. The sulphate motifs within GAGs represent a key information storage and transfer medium, which cells can interpret, to effect tissue homeostasis. The glyco-code contained in GAGs is an IT system which nature has developed over many hundreds of millions of years of evolution. However, despite the complexity and biodiversity of GAG structures, it is the sulphate motifs which are key cell-directive players in the glyco-code and the sophisticated structures to which they are attached may be viewed as molecular scaffolds whereby varied planar orientations or densities of the sulphate groups can be explored to achieve optimal interactions with their respective ligands. Significant inroads have been made in the sequencing of GAGs and encoded sequences linked with biological processes continue to be identified. A greater understanding of this glyco-code will undoubtedly continue to improve our understanding of the development and regulation of connective tissues and may lead to significant improvements in how this information is applied in advanced strategies in repair biology.

Abbreviations

     
  • APC

    activated protein C

  •  
  • APP

    amyloid precursor protein

  •  
  • BMP

    bone morphogenetic protein

  •  
  • CAH

    carbonic anhydrase

  •  
  • CLL

    chronic lymphocytic leukaemia

  •  
  • CREB

    cAMP response element-binding protein

  •  
  • CS

    chondroitin sulphate

  •  
  • CSF

    colony-stimulating factor

  •  
  • CSPG-4

    CS–PG-4

  •  
  • DS

    dermatan sulphate

  •  
  • ECM

    extracellular matrix

  •  
  • ESCs

    embryonic stem cells

  •  
  • GAG

    glycosaminoglycan

  •  
  • HA

    hyaluronan

  •  
  • HGF

    hepatocyte growth factor

  •  
  • HYAL

    hyaluronidase

  •  
  • ITI

    inter-α-trypsin inhibitor

  •  
  • IVD

    intervertebral disc

  •  
  • LAR

    leucocyte common antigen-related phosphatase

  •  
  • LLC

    Lewis lung carcinoma

  •  
  • MK

    midkine

  •  
  • MM

    multiple myeloma

  •  
  • MSC

    mesenchymal stem cell

  •  
  • NG2

    nerve-glial antigen-2

  •  
  • NgR1

    Nogo-1 receptor

  •  
  • PCM

    pericellular matrix

  •  
  • PDAC

    pancreatic ductal adenocarcinoma

  •  
  • PGs

    proteoglycans

  •  
  • PLGA

    polylactic-co-glycolic acid

  •  
  • Pre-α-TI

    pre-α-trypsin inhibitor

  •  
  • PTN

    pleiotrophin

  •  
  • PTPR

    protein tyrosine phosphatase receptor

  •  
  • RAGE

    Receptor for Advanced Glycation End products

  •  
  • RHAMM

    receptor for HA mediated motility

  •  
  • RPTP-β

    receptor-type protein tyrosine phosphatase beta

  •  
  • SIGLECS

    sialic acid-binding immunoglobulin-like lectins

  •  
  • SLRP

    small leucine-rich PG

  •  
  • SPI

    serine protease inhibitor

  •  
  • SRPX2

    Sushi repeat protein, X-linked 2

  •  
  • TM-β

    thrombomodulin

  •  
  • uPA

    urokinase type plasminogen activator

  •  
  • WISP

    WNT1 inducible signalling pathway

  •  
  • Wnt

    Wingless/int

Author Contribution

All authors contributed to the writing of this manuscript. J.M. co-ordinated the review comments and final content of the manuscript. All authors endorsed the final version of the manuscript.

Acknowledgments

The infrastructure was provided by The Institute of Bone and Joint Research, Kolling Institute of Medical Research and The University of Sydney.

Competing Interests

The Authors declare that there are no competing interests associated with the manuscript.

References

References
1
Melrose
,
J.
(
2016
)
The Glycosaminoglycan/Glycan Interactome: A Bioinformatic Platform. An Evolutionary Conserved Biosensor Platform Controlling Cellular Behaviour, Tissue Morphogenesis, Tissue Assembly
,
Scholars Press, Schaltungsdienst Lange OHG
,
Saarbrucken, Berlin
2
Furukawa
,
J.
,
Okada
,
K.
and
Shinohara
,
Y.
(
2016
)
Glycomics of human embryonic stem cells and human induced pluripotent stem cells
.
Glycoconj. J.
33
,
707
715
3
Sugahara
,
K.
,
Mizumoto
,
S.
and
Yamada
,
S.
(
2014
)
Chondroitin sulphate
. In
Encyclopedia of Polymeric Nanomaterials
(Kobayashi, S. and Müllen, K., eds), Springer, Berlin, Heidelberg
4
Linnartz-Gerlach
,
B.
,
Mathews
,
M.
and
Neumann
,
H.
(
2014
)
Sensing the neuronal glycocalyx by glial sialic acid binding immunoglobulin-like lectins
.
Neuroscience
275
,
113
124
5
Tarbell
,
J.M.
and
Ebong
,
E.E.
(
2008
)
The endothelial glycocalyx: a mechano-sensor and -transducer
.
Sci. Signal.
1
,
pt8
6
Curry
,
F.E.
and
Adamson
,
R.H.
(
2012
)
Endothelial glycocalyx: permeability barrier and mechanosensor
.
Ann. Biomed. Eng.
40
,
828
839
7
Dawson
,
G.
(
2014
)
Glycosignaling: a general review
.
Adv. Neurobiol.
9
,
293
306
8
Tarbell
,
J.M.
,
Simon
,
S.I.
and
Curry
,
F.R.
(
2014
)
Mechanosensing at the vascular interface
.
Annu. Rev. Biomed. Eng.
16
,
505
532
9
Fu
,
B.M.
and
Tarbell
,
J.M.
(
2013
)
Mechano-sensing and transduction by endothelial surface glycocalyx: composition, structure, and function
.
Wiley Interdiscip. Rev. Syst. Biol. Med.
5
,
381
390
10
Chignalia
,
A.Z.
,
Yetimakman
,
F.
,
Christiaans
,
S.C.
,
Unal
,
S.
,
Bayrakci
,
B.
,
Wagener
,
B.M.
et al. 
(
2016
)
The glycocalyx and trauma: a review
.
Shock
45
,
338
348
11
Apostolopoulos
,
V.
,
Stojanovska
,
L.
and
Gargosky
,
S.E.
(
2015
)
MUC1 (CD227): a multi-tasked molecule
.
Cell. Mol. Life Sci.
72
,
4475
4500
12
Corfield
,
A.P.
(
2015
)
Mucins: a biologically relevant glycan barrier in mucosal protection
.
Biochim. Biophys. Acta
1850
,
236
252
13
Ouwerkerk
,
J.P.
,
de Vos
,
W.M.
and
Belzer
,
C.
(
2013
)
Glycobiome: bacteria and mucus at the epithelial interface
.
Best Pract. Res. Clin. Gastroenterol.
27
,
25
38
14
Dudas
,
B.
and
Semeniken
,
K.
(
2012
)
Glycosaminoglycans and neuroprotection
.
Handb. Exp. Pharmacol.
325
343
15
Haeren
,
R.H.
,
van de Ven
,
S.E.
,
van Zandvoort
,
M.A.
,
Vink
,
H.
,
van Overbeeke
,
J.J.
,
Hoogland
,
G.
et al. 
(
2016
)
Assessment and imaging of the cerebrovascular glycocalyx
.
Curr. Neurovasc. Res.
13
,
249
260
16
Sugahara
,
K.
,
Mikami
,
T.
,
Uyama
,
T.
,
Mizuguchi
,
S.
,
Nomura
,
K.
and
Kitagawa
,
H.
(
2003
)
Recent advances in the structural biology of chondroitin sulfate and dermatan sulfate
.
Curr. Opin. Struct. Biol.
13
,
612
620
17
Caterson
,
B.
(
2012
)
Fell-Muir Lecture: chondroitin sulphate glycosaminoglycans: fun for some and confusion for others
.
Int. J. Exp. Pathol.
93
,
1
10
18
Cummings
,
R.D.
(
2009
)
The repertoire of glycan determinants in the human glycome
.
Mol. Biosyst.
5
,
1087
1104
19
Maeda
,
N.
,
Fukazawa
,
N.
and
Hata
,
T.
(
2006
)
The binding of chondroitin sulfate to pleiotrophin/heparin-binding growth-associated molecule is regulated by chain length and oversulfated structures
.
J. Biol. Chem.
281
,
4894
4902
20
Pufe
,
T.
,
Bartscher
,
M.
,
Petersen
,
W.
,
Tillmann
,
B.
and
Mentlein
,
R.
(
2003
)
Expression of pleiotrophin, an embryonic growth and differentiation factor, in rheumatoid arthritis
.
Arthritis Rheum.
48
,
660
667
21
Pufe
,
T.
,
Bartscher
,
M.
,
Petersen
,
W.
,
Tillmann
,
B.
and
Mentlein
,
R.
(
2003
)
Pleiotrophin, an embryonic differentiation and growth factor, is expressed in osteoarthritis
.
Osteoarthr. Cartil.
11
,
260
264
22
Pufe
,
T.
,
Groth
,
G.
,
Goldring
,
M.B.
,
Tillmann
,
B.
and
Mentlein
,
R.
(
2007
)
Effects of pleiotrophin, a heparin-binding growth factor, on human primary and immortalized chondrocytes
.
Osteoarthr. Cartil.
15
,
155
162
23
Malavaki
,
C.
,
Mizumoto
,
S.
,
Karamanos
,
N.
and
Sugahara
,
K.
(
2008
)
Recent advances in the structural study of functional chondroitin sulfate and dermatan sulfate in health and disease
.
Connect. Tissue Res.
49
,
133
139
24
Nandini
,
C.D.
and
Sugahara
,
K.
(
2006
)
Role of the sulfation pattern of chondroitin sulfate in its biological activities and in the binding of growth factors
.
Adv. Pharmacol.
53
,
253
279
25
Purushothaman
,
A.
,
Sugahara
,
K.
and
Faissner
,
A.
(
2012
)
Chondroitin sulfate “wobble motifs” modulate maintenance and differentiation of neural stem cells and their progeny
.
J. Biol. Chem.
287
,
2935
2942
26
Izumikawa
,
T.
,
Sato
,
B.
and
Kitagawa
,
H.
(
2014
)
Chondroitin sulfate is indispensable for pluripotency and differentiation of mouse embryonic stem cells
.
Sci. Rep.
4
,
3701
27
Milev
,
P.
,
Maurel
,
P.
,
Chiba
,
A.
,
Mevissen
,
M.
,
Popp
,
S.
,
Yamaguchi
,
Y.
et al. 
(
1998
)
Differential regulation of expression of hyaluronan-binding proteoglycans in developing brain: aggrecan, versican, neurocan, and brevican
.
Biochem. Biophys. Res. Commun.
247
,
207
212
28
Howell
,
M.D.
and
Gottschall
,
P.E.
(
2012
)
Lectican proteoglycans, their cleaving metalloproteinases, and plasticity in the central nervous system extracellular microenvironment
.
Neuroscience
217
,
6
18
29
Yamaguchi
,
Y.
(
2000
)
Lecticans: organizers of the brain extracellular matrix
.
Cell. Mol. Life Sci.
57
,
276
289
30
Iozzo
,
R.V.
and
Schaefer
,
L.
(
2015
)
Proteoglycan form and function: a comprehensive nomenclature of proteoglycans
.
Matrix Biol.
42
,
11
55
31
Ruoslahti
,
E.
(
1988
)
Structure and biology of proteoglycans
.
Annu. Rev. Cell Biol.
4
,
229
255
32
Sorg
,
B.A.
,
Berretta
,
S.
,
Blacktop
,
J.M.
,
Fawcett
,
J.W.
,
Kitagawa
,
H.
,
Kwok
,
J.C.
et al. 
(
2016
)
Casting a wide net: role of perineuronal nets in neural plasticity
.
J. Neurosci.
36
,
11459
11468
33
Suttkus
,
A.
,
Morawski
,
M.
and
Arendt
,
T.
(
2016
)
Protective properties of neural extracellular matrix
.
Mol. Neurobiol.
53
,
73
82
34
Dellett
,
M.
,
Hu
,
W.
,
Papadaki
,
V.
and
Ohnuma
,
S.
(
2012
)
Small leucine rich proteoglycan family regulates multiple signalling pathways in neural development and maintenance
.
Dev. Growth Differ.
54
,
327
340
35
Iozzo
,
R.V.
and
Schaefer
,
L.
(
2010
)
Proteoglycans in health and disease: novel regulatory signaling mechanisms evoked by the small leucine-rich proteoglycans
.
FEBS J.
277
,
3864
3875
36
Moreth
,
K.
,
Iozzo
,
R.V.
and
Schaefer
,
L.
(
2012
)
Small leucine-rich proteoglycans orchestrate receptor crosstalk during inflammation
.
Cell Cycle
11
,
2084
2091
37
Nikitovic
,
D.
,
Aggelidakis
,
J.
,
Young
,
M.F.
,
Iozzo
,
R.V.
,
Karamanos
,
N.K.
and
Tzanakakis
,
G.N.
(
2012
)
The biology of small leucine-rich proteoglycans in bone pathophysiology
.
J. Biol. Chem.
287
,
33926
33933
38
Schaefer
,
L.
and
Iozzo
,
R.V.
(
2008
)
Biological functions of the small leucine-rich proteoglycans: from genetics to signal transduction
.
J. Biol. Chem.
283
,
21305
21309
39
Acharya
,
S.
,
Foletta
,
V.C.
,
Lee
,
J.W.
,
Rayborn
,
M.E.
,
Rodriguez
,
I.R.
,
Young
, III,
W.S.
et al. 
(
2000
)
SPACRCAN, a novel human interphotoreceptor matrix hyaluronan-binding proteoglycan synthesized by photoreceptors and pinealocytes
.
J. Biol. Chem.
275
,
6945
6955
40
Chen
,
Q.
,
Cai
,
S.
,
Shadrach
,
K.G.
,
Prestwich
,
G.D.
and
Hollyfield
,
J.G.
(
2004
)
Spacrcan binding to hyaluronan and other glycosaminoglycans. Molecular and biochemical studies
.
J. Biol. Chem.
279
,
23142
23150
41
Gubbiotti
,
M.A.
,
Neill
,
T.
and
Iozzo
,
R.V.
(
2017
)
A current view of perlecan in physiology and pathology: a mosaic of functions
.
Matrix Biol.
57-58
,
285
298
42
Iozzo
,
R.V.
(
1994
)
Perlecan: a gem of a proteoglycan
.
Matrix Biol.
14
,
203
208
43
Lord
,
M.S.
,
Chuang
,
C.Y.
,
Melrose
,
J.
,
Davies
,
M.J.
,
Iozzo
,
R.V.
and
Whitelock
,
J.M.
(
2014
)
The role of vascular-derived perlecan in modulating cell adhesion, proliferation and growth factor signaling
.
Matrix Biol.
35
,
112
122
44
Melrose
,
J.
,
Roughley
,
P.
,
Knox
,
S.
,
Smith
,
S.
,
Lord
,
M.
and
Whitelock
,
J.
(
2006
)
The structure, location, and function of perlecan, a prominent pericellular proteoglycan of fetal, postnatal, and mature hyaline cartilages
.
J. Biol. Chem.
281
,
36905
36914
45
Whitelock
,
J.M.
,
Melrose
,
J.
and
Iozzo
,
R.V.
(
2008
)
Diverse cell signaling events modulated by perlecan
.
Biochemistry
47
,
11174
11183
46
Zoeller
,
J.J.
,
McQuillan
,
A.
,
Whitelock
,
J.
,
Ho
,
S.Y.
and
Iozzo
,
R.V.
(
2008
)
A central function for perlecan in skeletal muscle and cardiovascular development
.
J. Cell Biol.
181
,
381
394
47
Knox
,
S.
,
Fosang
,
A.J.
,
Last
,
K.
,
Melrose
,
J.
and
Whitelock
,
J.
(
2005
)
Perlecan from human epithelial cells is a hybrid heparan/chondroitin/keratan sulfate proteoglycan
.
FEBS Lett.
579
,
5019
5023
48
Shu
,
C.
,
Hughes
,
C.
,
Smith
,
S.M.
,
Smith
,
M.M.
,
Hayes
,
A.
,
Caterson
,
B.
et al. 
(
2013
)
The ovine newborn and human foetal intervertebral disc contain perlecan and aggrecan variably substituted with native 7D4 CS sulphation motif: spatiotemporal immunolocalisation and co-distribution with Notch-1 in the human foetal disc
.
Glycoconj. J.
30
,
717
725
49
Kvist
,
A.J.
,
Johnson
,
A.E.
,
Morgelin
,
M.
,
Gustafsson
,
E.
,
Bengtsson
,
E.
,
Lindblom
,
K.
et al. 
(
2006
)
Chondroitin sulfate perlecan enhances collagen fibril formation. Implications for perlecan chondrodysplasias
.
J. Biol. Chem.
281
,
33127
33139
50
Pangalos
,
M.N.
,
Shioi
,
J.
,
Efthimiopoulos
,
S.
,
Wu
,
A.
and
Robakis
,
N.K.
(
1996
)
Characterization of appican, the chondroitin sulfate proteoglycan form of the Alzheimer amyloid precursor protein
.
Neurodegeneration
5
,
445
451
51
Tsuchida
,
K.
,
Shioi
,
J.
,
Yamada
,
S.
,
Boghosian
,
G.
,
Wu
,
A.
,
Cai
,
H.
et al. 
(
2001
)
Appican, the proteoglycan form of the amyloid precursor protein, contains chondroitin sulfate E in the repeating disaccharide region and 4-O-sulfated galactose in the linkage region
.
J. Biol. Chem.
276
,
37155
37160
52
Umehara
,
Y.
,
Yamada
,
S.
,
Nishimura
,
S.
,
Shioi
,
J.
,
Robakis
,
N.K.
and
Sugahara
,
K.
(
2004
)
Chondroitin sulfate of appican, the proteoglycan form of amyloid precursor protein, produced by C6 glioma cells interacts with heparin-binding neuroregulatory factors
.
FEBS Lett.
557
,
233
238
53
Wu
,
A.
,
Pangalos
,
M.N.
,
Efthimiopoulos
,
S.
,
Shioi
,
J.
and
Robakis
,
N.K.
(
1997
)
Appican expression induces morphological changes in C6 glioma cells and promotes adhesion of neural cells to the extracellular matrix
.
J. Neurosci.
17
,
4987
4993
PMID:
[PubMed]
54
Kadoya
,
K.
,
Fukushi
,
J.
,
Matsumoto
,
Y.
,
Yamaguchi
,
Y.
and
Stallcup
,
W.B.
(
2008
)
NG2 proteoglycan expression in mouse skin: altered postnatal skin development in the NG2 null mouse
.
J. Histochem. Cytochem.
56
,
295
303
55
Trotter
,
J.
,
Karram
,
K.
and
Nishiyama
,
A.
(
2010
)
NG2 cells: properties, progeny and origin
.
Brain Res. Rev.
63
,
72
82
56
Nishiyama
,
A.
,
Dahlin
,
K.J.
,
Prince
,
J.T.
,
Johnstone
,
S.R.
and
Stallcup
,
W.B.
(
1991
)
The primary structure of NG2, a novel membrane-spanning proteoglycan
.
J. Cell Biol.
114
,
359
371
57
Price
,
M.A.
,
Colvin Wanshura
,
L.E.
,
Yang
,
J.
,
Carlson
,
J.
,
Xiang
,
B.
,
Li
,
G.
et al. 
(
2011
)
CSPG4, a potential therapeutic target, facilitates malignant progression of melanoma
.
Pigment Cell Melanoma Res.
24
,
1148
1157
58
Campoli
,
M.
,
Ferrone
,
S.
and
Wang
,
X.
(
2010
)
Functional and clinical relevance of chondroitin sulfate proteoglycan 4
.
Adv. Cancer Res.
109
,
73
121
59
Mayayo
,
S.L.
,
Prestigio
,
S.
,
Maniscalco
,
L.
,
La Rosa
,
G.
,
Arico
,
A.
,
De Maria
,
R.
et al. 
(
2011
)
Chondroitin sulfate proteoglycan-4: a biomarker and a potential immunotherapeutic target for canine malignant melanoma
.
Vet. J.
190
,
e26
e30
60
Goretzki
,
L.
,
Burg
,
M.A.
,
Grako
,
K.A.
and
Stallcup
,
W.B.
(
1999
)
High-affinity binding of basic fibroblast growth factor and platelet-derived growth factor-AA to the core protein of the NG2 proteoglycan
.
J. Biol. Chem.
274
,
16831
16837
61
Burg
,
M.A.
,
Tillet
,
E.
,
Timpl
,
R.
and
Stallcup
,
W.B.
(
1996
)
Binding of the NG2 proteoglycan to type VI collagen and other extracellular matrix molecules
.
J. Biol. Chem.
271
,
26110
26116
62
Tillet
,
E.
,
Ruggiero
,
F.
,
Nishiyama
,
A.
and
Stallcup
,
W.B.
(
1997
)
The membrane-spanning proteoglycan NG2 binds to collagens V and VI through the central nonglobular domain of its core protein
.
J. Biol. Chem.
272
,
10769
10776
63
Fang
,
X.
,
Burg
,
M.A.
,
Barritt
,
D.
,
Dahlin-Huppe
,
K.
,
Nishiyama
,
A.
and
Stallcup
,
W.B.
(
1999
)
Cytoskeletal reorganization induced by engagement of the NG2 proteoglycan leads to cell spreading and migration
.
Mol. Biol. Cell
10
,
3373
3387
64
Stallcup
,
W.B.
(
2002
)
The NG2 proteoglycan: past insights and future prospects
.
J. Neurocytol.
31
,
423
435
65
Bourin
,
M.C.
and
Lindahl
,
U.
(
1990
)
Functional role of the polysaccharide component of rabbit thrombomodulin proteoglycan. Effects on inactivation of thrombin by antithrombin, cleavage of fibrinogen by thrombin and thrombin-catalysed activation of factor V
.
Biochem. J.
270
,
419
425
66
Esmon
,
C.T.
,
Esmon
,
N.L.
and
Harris
,
K.W.
(
1982
)
Complex formation between thrombin and thrombomodulin inhibits both thrombin-catalyzed fibrin formation and factor V activation
.
J. Biol. Chem.
257
,
7944
7947
PMID:
[PubMed]
67
Bourin
,
M.C.
,
Lundgren-Akerlund
,
E.
and
Lindahl
,
U.
(
1990
)
Isolation and characterization of the glycosaminoglycan component of rabbit thrombomodulin proteoglycan
.
J. Biol. Chem.
265
,
15424
15431
PMID:
[PubMed]
68
Bourin
,
M.C.
,
Ohlin
,
A.K.
,
Lane
,
D.A.
,
Stenflo
,
J.
and
Lindahl
,
U.
(
1988
)
Relationship between anticoagulant activities and polyanionic properties of rabbit thrombomodulin
.
J. Biol. Chem.
263
,
8044
8052
PMID:
[PubMed]
69
Nawa
,
K.
,
Sakano
,
K.
,
Fujiwara
,
H.
,
Sato
,
Y.
,
Sugiyama
,
N.
,
Teruuchi
,
T.
et al. 
(
1990
)
Presence and function of chondroitin-4-sulfate on recombinant human soluble thrombomodulin
.
Biochem. Biophys. Res. Commun.
171
,
729
737
70
Nguyen
,
M.
,
Arkell
,
J.
and
Jackson
,
C.J.
(
2000
)
Activated protein C directly activates human endothelial gelatinase A
.
J. Biol. Chem.
275
,
9095
9098
71
Xue
,
M.
,
March
,
L.
,
Sambrook
,
P.N.
and
Jackson
,
C.J.
(
2007
)
Differential regulation of matrix metalloproteinase 2 and matrix metalloproteinase 9 by activated protein C: relevance to inflammation in rheumatoid arthritis
.
Arthritis Rheum.
56
,
2864
2874
72
Xue
,
M.
,
Thompson
,
P.
,
Kelso
,
I.
and
Jackson
,
C.
(
2004
)
Activated protein C stimulates proliferation, migration and wound closure, inhibits apoptosis and upregulates MMP-2 activity in cultured human keratinocytes
.
Exp. Cell Res.
299
,
119
127
73
Conway
,
E.M.
(
2012
)
Thrombomodulin and its role in inflammation
.
Semin. Immunopathol.
34
,
107
125
74
Shi
,
C.S.
,
Shi
,
G.Y.
,
Hsiao
,
H.M.
,
Kao
,
Y.C.
,
Kuo
,
K.L.
,
Ma
,
C.Y.
et al. 
(
2008
)
Lectin-like domain of thrombomodulin binds to its specific ligand Lewis Y antigen and neutralizes lipopolysaccharide-induced inflammatory response
.
Blood
112
,
3661
3670
75
Dwyer
,
C.A.
,
Katoh
,
T.
,
Tiemeyer
,
M.
and
Matthews
,
R.T.
(
2015
)
Neurons and glia modify receptor protein-tyrosine phosphatase ζ (RPTPζ)/phosphacan with cell-specific O-mannosyl glycans in the developing brain
.
J. Biol. Chem.
290
,
10256
10273
76
Cantley
,
L.C.
,
Auger
,
K.R.
,
Carpenter
,
C.
,
Duckworth
,
B.
,
Graziani
,
A.
,
Kapeller
,
R.
et al. 
(
1991
)
Oncogenes and signal transduction
.
Cell
64
,
281
302
77
Hunter
,
T.
(
1991
)
Cooperation between oncogenes
.
Cell
64
,
249
270
78
Hunter
,
T.
(
1995
)
Protein kinases and phosphatases: the yin and yang of protein phosphorylation and signaling
.
Cell
80
,
225
236
79
Ullrich
,
A.
and
Schlessinger
,
J.
(
1990
)
Signal transduction by receptors with tyrosine kinase activity
.
Cell
61
,
203
212
80
Garwood
,
J.
,
Heck
,
N.
,
Reichardt
,
F.
and
Faissner
,
A.
(
2003
)
Phosphacan short isoform, a novel non-proteoglycan variant of phosphacan/receptor protein tyrosine phosphatase-β, interacts with neuronal receptors and promotes neurite outgrowth
.
J. Biol. Chem.
278
,
24164
24173
81
Kokenyesi
,
R.
and
Bernfield
,
M.
(
1994
)
Core protein structure and sequence determine the site and presence of heparan sulfate and chondroitin sulfate on syndecan-1
.
J. Biol. Chem.
269
,
12304
12309
82
Deepa
,
S.S.
,
Yamada
,
S.
,
Zako
,
M.
,
Goldberger
,
O.
and
Sugahara
,
K.
(
2004
)
Chondroitin sulfate chains on syndecan-1 and syndecan-4 from normal murine mammary gland epithelial cells are structurally and functionally distinct and cooperate with heparan sulfate chains to bind growth factors. A novel function to control binding of midkine, pleiotrophin, and basic fibroblast growth factor
.
J. Biol. Chem.
279
,
37368
37376
83
Ueno
,
M.
,
Yamada
,
S.
,
Zako
,
M.
,
Bernfield
,
M.
and
Sugahara
,
K.
(
2001
)
Structural characterization of heparan sulfate and chondroitin sulfate of syndecan-1 purified from normal murine mammary gland epithelial cells. Common phosphorylation of xylose and differential sulfation of galactose in the protein linkage region tetrasaccharide sequence
.
J. Biol. Chem.
276
,
29134
29140
84
Woods
,
A.
,
Longley
,
R.L.
,
Tumova
,
S.
and
Couchman
,
J.R.
(
2000
)
Syndecan-4 binding to the high affinity heparin-binding domain of fibronectin drives focal adhesion formation in fibroblasts
.
Arch. Biochem. Biophys.
374
,
66
72
85
Kugelman
,
L.C.
,
Ganguly
,
S.
,
Haggerty
,
J.G.
,
Weissman
,
S.M.
and
Milstone
,
L.M.
(
1992
)
The core protein of epican, a heparan sulfate proteoglycan on keratinocytes, is an alternative form of CD44
.
J. Invest. Dermatol.
99
,
886
891
86
Milstone
,
L.M.
,
Hough-Monroe
,
L.
,
Kugelman
,
L.C.
,
Bender
,
J.R.
and
Haggerty
,
J.G.
(
1994
)
Epican, a heparan/chondroitin sulfate proteoglycan form of CD44, mediates cell-cell adhesion
.
J. Cell Sci.
107
(
Pt 11
),
3183
3190
87
Enghild
,
J.J.
,
Salvesen
,
G.
,
Thogersen
,
I.B.
,
Valnickova
,
Z.
,
Pizzo
,
S.V.
and
Hefta
,
S.A.
(
1993
)
Presence of the protein-glycosaminoglycan-protein covalent cross-link in the inter-alpha-inhibitor-related proteinase inhibitor heavy chain 2/bikunin
.
J. Biol. Chem.
268
,
8711
8716
88
Zhuo
,
L.
,
Hascall
,
V.C.
and
Kimata
,
K.
(
2004
)
Inter-α-trypsin inhibitor, a covalent protein-glycosaminoglycan-protein complex
.
J. Biol. Chem.
279
,
38079
38082
89
Melrose
,
J.
,
Shen
,
B.
and
Ghosh
,
P.
(
2001
)
Affinity and Western blotting reveal homologies between ovine intervertebral disc serine proteinase inhibitory proteins and bovine pancreatic trypsin inhibitor
.
Proteomics
1
,
1529
1533
90
Rodgers
,
K.J.
,
Melrose
,
J.
and
Ghosh
,
P.
(
1996
)
Purification and characterisation of 6 and 58 kDa forms of the endogenous serine proteinase inhibitory proteins of ovine articular cartilage
.
Biol. Chem.
377
,
837
845
91
Lord
,
M.S.
,
Day
,
A.J.
,
Youssef
,
P.
,
Zhuo
,
L.
,
Watanabe
,
H.
,
Caterson
,
B.
et al. 
(
2013
)
Sulfation of the bikunin chondroitin sulfate chain determines heavy chain · hyaluronan complex formation
.
J. Biol. Chem.
288
,
22930
22941
92
Chi
,
L.
,
Wolff
,
J.J.
,
Laremore
,
T.N.
,
Restaino
,
O.F.
,
Xie
,
J.
,
Schiraldi
,
C.
et al. 
(
2008
)
Structural analysis of bikunin glycosaminoglycan
.
J. Am. Chem. Soc.
130
,
2617
2625
93
Ly
,
M.
,
Leach
, III,
F.E.
,
Laremore
,
T.N.
,
Toida
,
T.
,
Amster
,
I.J.
and
Linhardt
,
R.J.
(
2011
)
The proteoglycan bikunin has a defined sequence
.
Nat. Chem. Biol.
7
,
827
833
94
Mayne
,
R.
,
van der Rest
,
M.
,
Ninomiya
,
Y.
and
Olsen
,
B.R.
(
1985
)
The structure of type IX collagen
.
Ann. N. Y. Acad. Sci.
460
,
38
46
95
van der Rest
,
M.
,
Mayne
,
R.
,
Ninomiya
,
Y.
,
Seidah
,
N.G.
,
Chretien
,
M.
and
Olsen
,
B.R.
(
1985
)
The structure of type IX collagen
.
J. Biol. Chem.
260
,
220
225
PMID:
[PubMed]
96
Bruckner
,
P.
,
Vaughan
,
L.
and
Winterhalter
,
K.H.
(
1985
)
Type IX collagen from sternal cartilage of chicken embryo contains covalently bound glycosaminoglycans
.
Proc. Natl Acad. Sci. U.S.A.
82
,
2608
2612
97
Irwin
,
M.H.
and
Mayne
,
R.
(
1986
)
Use of monoclonal antibodies to locate the chondroitin sulfate chain(s) in type IX collagen
.
J. Biol. Chem.
261
,
16281
16283
PMID:
[PubMed]
98
McCormick
,
D.
,
van der Rest
,
M.
,
Goodship
,
J.
,
Lozano
,
G.
,
Ninomiya
,
Y.
and
Olsen
,
B.R.
(
1987
)
Structure of the glycosaminoglycan domain in the type IX collagen-proteoglycan
.
Proc. Natl Acad. Sci. U.S.A.
84
,
4044
4048
99
Noro
,
A.
,
Kimata
,
K.
,
Oike
,
Y.
,
Shinomura
,
T.
,
Maeda
,
N.
,
Yano
,
S.
et al. 
(
1983
)
Isolation and characterization of a third proteoglycan (PG-Lt) from chick embryo cartilage which contains disulfide-bonded collagenous polypeptide
.
J. Biol. Chem.
258
,
9323
9331
PMID:
[PubMed]
100
Vaughan
,
L.
,
Winterhalter
,
K.H.
and
Bruckner
,
P.
(
1985
)
Proteoglycan Lt from chicken embryo sternum identified as type IX collagen
.
J. Biol. Chem.
260
,
4758
4763
PMID:
[PubMed]
101
Douglas
,
S.P.
and
Kadler
,
K.E.
(
1998
)
Specific glycanforms of type IX collagen accumulate in embryonic chick sterna after 17 days of development
.
Glycobiology
8
,
1013
1019
102
Arai
,
M.
,
Yada
,
T.
,
Suzuki
,
S.
and
Kimata
,
K.
(
1992
)
Isolation and characterization of type IX collagen-proteoglycan from the Swarm rat chondrosarcoma
.
Biochim. Biophys. Acta
1117
,
60
70
103
Diab
,
M.
,
Wu
,
J.J.
and
Eyre
,
D.R.
(
1996
)
Collagen type IX from human cartilage: a structural profile of intermolecular cross-linking sites
.
Biochem. J.
314
(
Pt 1
),
327
332
104
Yada
,
T.
,
Arai
,
M.
,
Suzuki
,
S.
and
Kimata
,
K.
(
1992
)
Occurrence of collagen and proteoglycan forms of type IX collagen in chick embryo cartilage. Production and characterization of a collagen form-specific antibody
.
J. Biol. Chem.
267
,
9391
9397
PMID:
[PubMed]
105
Yada
,
T.
,
Suzuki
,
S.
,
Kobayashi
,
K.
,
Kobayashi
,
M.
,
Hoshino
,
T.
,
Horie
,
K.
et al. 
(
1990
)
Occurrence in chick embryo vitreous humor of a type IX collagen proteoglycan with an extraordinarily large chondroitin sulfate chain and short alpha 1 polypeptide
.
J. Biol. Chem.
265
,
6992
6999
PMID:
[PubMed]
106
Skandalis
,
S.S.
,
Theocharis
,
D.A.
and
Noulas
,
A.V.
(
2007
)
Chondroitin sulphate proteoglycans in the vitreous gel of sheep and goat
.
Biomed. Chromatogr.
21
,
451
457
107
Theocharis
,
D.A.
,
Skandalis
,
S.S.
,
Noulas
,
A.V.
,
Papageorgakopoulou
,
N.
,
Theocharis
,
A.D.
and
Karamanos
,
N.K.
(
2008
)
Hyaluronan and chondroitin sulfate proteoglycans in the supramolecular organization of the mammalian vitreous body
.
Connect. Tissue Res.
49
,
124
128
108
Gordon
,
M.K.
,
Gerecke
,
D.R.
,
Dublet
,
B.
,
van der Rest
,
M.
and
Olsen
,
B.R.
(
1989
)
Type XII collagen. A large multidomain molecule with partial homology to type IX collagen
.
J. Biol. Chem.
264
,
19772
19778
PMID:
[PubMed]
109
Gordon
,
M.K.
,
Gerecke
,
D.R.
,
Dublet
,
B.
,
van der Rest
,
M.
,
Sugrue
,
S.P.
and
Olsen
,
B.R.
(
1990
)
The structure of type XII collagen
.
Ann. N. Y. Acad. Sci.
580
,
8
16
110
Aubert-Foucher
,
E.
,
Font
,
B.
,
Eichenberger
,
D.
,
Goldschmidt
,
D.
,
Lethias
,
C.
and
van der Rest
,
M.
(
1992
)
Purification and characterization of native type XIV collagen
.
J. Biol. Chem.
267
,
15759
15764
PMID:
[PubMed]
111
Bocock
,
J.P.
,
Edgell
,
C.J.
,
Marr
,
H.S.
and
Erickson
,
A.H.
(
2003
)
Human proteoglycan testican-1 inhibits the lysosomal cysteine protease cathepsin L
.
Eur. J. Biochem.
270
,
4008
4015
112
Nakada
,
M.
,
Yamada
,
A.
,
Takino
,
T.
,
Miyamori
,
H.
,
Takahashi
,
T.
,
Yamashita
,
J.
et al. 
(
2001
)
Suppression of membrane-type 1 matrix metalloproteinase (MMP)-mediated MMP-2 activation and tumor invasion by testican 3 and its splicing variant gene product, N-Tes
.
Cancer Res.
61
,
8896
8902
PMID:
[PubMed]
113
Nakada
,
M.
,
Miyamori
,
H.
,
Yamashita
,
J.
and
Sato
,
H.
(
2003
)
Testican 2 abrogates inhibition of membrane-type matrix metalloproteinases by other testican family proteins
.
Cancer Res.
63
,
3364
3369
PMID:
[PubMed]
114
Marr
,
H.S.
,
Basalamah
,
M.A.
and
Edgell
,
C.J.
(
1997
)
Endothelial cell expression of testican mRNA
.
Endothelium
5
,
209
219
115
Marr
,
H.S.
,
Basalamah
,
M.A.
,
Bouldin
,
T.W.
,
Duncan
,
A.W.
and
Edgell
,
C.J.
(
2000
)
Distribution of testican expression in human brain
.
Cell Tissue Res.
302
,
139
144
116
Kolset
,
S.O.
and
Tveit
,
H.
(
2008
)
Serglycin—structure and biology
.
Cell. Mol. Life Sci.
65
,
1073
1085
117
Ronnberg
,
E.
,
Melo
,
F.R.
and
Pejler
,
G.
(
2012
)
Mast cell proteoglycans
.
J. Histochem. Cytochem.
60
,
950
962
118
Ronnberg
,
E.
and
Pejler
,
G.
(
2012
)
Serglycin: the master of the mast cell
.
Methods Mol. Biol.
836
,
201
217
119
Scully
,
O.J.
,
Chua
,
P.J.
,
Harve
,
K.S.
,
Bay
,
B.H.
and
Yip
,
G.W.
(
2012
)
Serglycin in health and diseases
.
Anat. Rec. (Hoboken)
295
,
1415
1420
120
Mulloy
,
B.
,
Lever
,
R.
and
Page
,
C.P.
(
2017
)
Mast cell glycosaminoglycans
.
Glycoconj. J.
34
,
351
361
121
Farrugia
,
B.L.
,
Whitelock
,
J.M.
,
O'Grady
,
R.
,
Caterson
,
B.
and
Lord
,
M.S.
(
2016
)
Mast cells produce a unique chondroitin sulfate epitope
.
J. Histochem. Cytochem.
64
,
85
98
122
Chang
,
M.Y.
,
Olin
,
K.L.
,
Tsoi
,
C.
,
Wight
,
T.N.
and
Chait
,
A.
(
1998
)
Human monocyte-derived macrophages secrete two forms of proteoglycan-macrophage colony-stimulating factor that differ in their ability to bind low density lipoproteins
.
J. Biol. Chem.
273
,
15985
15992
123
Suzu
,
S.
,
Kimura
,
F.
,
Yamada
,
M.
,
Yanai
,
N.
,
Kawashima
,
T.
,
Nagata
,
N.
et al. 
(
1994
)
Direct interaction of proteoglycan macrophage colony-stimulating factor and basic fibroblast growth factor
.
Blood
83
,
3113
3119
PMID:
[PubMed]
124
Aravind
,
L.
and
Koonin
,
E.V.
(
2001
)
The DNA-repair protein AlkB, EGL-9, and leprecan define new families of 2-oxoglutarate- and iron-dependent dioxygenases
.
Genome Biol.
2
,
research0007.1
125
Jaakkola
,
P.M.
and
Rantanen
,
K.
(
2013
)
The regulation, localization, and functions of oxygen-sensing prolyl hydroxylase PHD3
.
Biol. Chem.
394
,
449
457
126
Pientka
,
F.K.
,
Hu
,
J.
,
Schindler
,
S.G.
,
Brix
,
B.
,
Thiel
,
A.
,
Johren
,
O.
et al. 
(
2012
)
Oxygen sensing by the prolyl-4-hydroxylase PHD2 within the nuclear compartment and the influence of compartmentalisation on HIF-1 signalling
.
J. Cell Sci.
125
,
5168
5176
127
Place
,
T.L.
and
Domann
,
F.E.
(
2013
)
Prolyl-hydroxylase 3: evolving roles for an ancient signaling protein
.
Hypoxia (Auckl).
2013
,
13
17
PMID:
[PubMed]
128
Wong
,
B.W.
,
Kuchnio
,
A.
,
Bruning
,
U.
and
Carmeliet
,
P.
(
2013
)
Emerging novel functions of the oxygen-sensing prolyl hydroxylase domain enzymes
.
Trends Biochem. Sci.
38
,
3
11
129
Hayes
,
A.J.
,
Hughes
,
C.E.
,
Ralphs
,
J.R.
and
Caterson
,
B.
(
2011
)
Chondroitin sulphate sulphation motif expression in the ontogeny of the intervertebral disc
.
Eur. Cell Mater.
21
,
1
14
130
Hayes
,
A.J.
,
Hughes
,
C.E.
,
Smith
,
S.M.
,
Caterson
,
B.
,
Little
,
C.B.
and
Melrose
,
J.
(
2016
)
The CS sulfation motifs 4C3, 7D4, 3B3[−]; and perlecan identify stem cell populations and their niches, activated progenitor cells and transitional areas of tissue development in the fetal human elbow
.
Stem Cells Dev.
25
,
836
847
131
Melrose
,
J.
,
Smith
,
S.M.
,
Hughes
,
C.E.
,
Little
,
C.B.
,
Catersob
,
B.
and
Hayes
,
A.J.
(
2016
)
The 7D4, 4C3 and 3B3 (−) chondroitin sulphation motifs are expressed at sites of cartilage and bone morphogenesis during foetal human knee joint development
.
J. Glycobiol.
5
,
1
132
Melrose
,
J.
,
Isaacs
,
M.D.
,
Smith
,
S.M.
,
Hughes
,
C.E.
,
Little
,
C.B.
,
Caterson
,
B.
et al. 
(
2012
)
Chondroitin sulphate and heparan sulphate sulphation motifs and their proteoglycans are involved in articular cartilage formation during human foetal knee joint development
.
Histochem. Cell Biol.
138
,
461
475
133
Hayes
,
A.J.
,
Tudor
,
D.
,
Nowell
,
M.A.
,
Caterson
,
B.
and
Hughes
,
C.E.
(
2008
)
Chondroitin sulfate sulfation motifs as putative biomarkers for isolation of articular cartilage progenitor cells
.
J. Histochem. Cytochem.
56
,
125
138
134
Cortes
,
M.
,
Baria
,
A.T.
and
Schwartz
,
N.B.
(
2009
)
Sulfation of chondroitin sulfate proteoglycans is necessary for proper Indian hedgehog signaling in the developing growth plate
.
Development
136
,
1697
1706
135
Palma
,
V.
,
Carrasco
,
H.
,
Reinchisi
,
G.
,
Olivares
,
G.
,
Faunes
,
F.
and
Larrain
,
J.
(
2011
)
SHh activity and localization is regulated by perlecan
.
Biol. Res.
44
,
63
67
136
Dowthwaite
,
G.P.
,
Bishop
,
J.C.
,
Redman
,
S.N.
,
Khan
,
I.M.
,
Rooney
,
P.
,
Evans
,
D.J.
et al. 
(
2004
)
The surface of articular cartilage contains a progenitor cell population
.
J. Cell Sci.
117
,
889
897
137
Hollander
,
A.P.
,
Dickinson
,
S.C.
and
Kafienah
,
W.
(
2010
)
Stem cells and cartilage development: complexities of a simple tissue
.
Stem Cells
28
,
1992
1996
138
Caplan
,
A.I.
(
2008
)
All MSCs are pericytes?
Cell Stem Cell
3
,
229
230
139
Caplan
,
A.I.
(
2017
)
New MSC: MSCs as pericytes are sentinels and gatekeepers
.
J. Orthop. Res.
35
,
1151
1159
140
da Silva Meirelles
,
L.
,
Caplan
,
A.I.
and
Nardi
,
N.B.
(
2008
)
In search of the in vivo identity of mesenchymal stem cells
.
Stem Cells
26
,
2287
2299
141
Crisan
,
M.
,
Yap
,
S.
,
Casteilla
,
L.
,
Chen
,
C.W.
,
Corselli
,
M.
,
Park
,
T.S.
et al. 
(
2008
)
A perivascular origin for mesenchymal stem cells in multiple human organs
.
Cell Stem Cell
3
,
301
313
142
Bergers
,
G.
and
Song
,
S.
(
2005
)
The role of pericytes in blood-vessel formation and maintenance
.
Neuro-Oncology
7
,
452
464
143
Diaz-Flores
,
L.
,
Gutierrez
,
R.
,
Madrid
,
J.F.
,
Varela
,
H.
,
Valladares
,
F.
,
Acosta
,
E.
et al. 
, (
2009
)
Pericytes. Morphofunction, interactions and pathology in a quiescent and activated mesenchymal cell niche
.
Histol. Histopathol.
24
,
909
969
144
Fukushi
,
J.
,
Makagiansar
,
I.T.
and
Stallcup
,
W.B.
(
2004
)
NG2 proteoglycan promotes endothelial cell motility and angiogenesis via engagement of galectin-3 and α3β1 integrin
.
Mol. Biol. Cell
15
,
3580
3590
145
Ribatti
,
D.
,
Nico
,
B.
and
Crivellato
,
E.
(
2011
)
The role of pericytes in angiogenesis
.
Int. J. Dev. Biol.
55
,
261
268
146
Zhang
,
C.
,
Zeng
,
L.
,
Emanueli
,
C.
and
Xu
,
Q.
(
2013
)
Blood flow and stem cells in vascular disease
.
Cardiovasc. Res.
99
,
251
259
147
Maeda
,
N.
,
He
,
J.
,
Yajima
,
Y.
,
Mikami
,
T.
,
Sugahara
,
K.
and
Yabe
,
T.
(
2003
)
Heterogeneity of the chondroitin sulfate portion of phosphacan/6B4 proteoglycan regulates its binding affinity for pleiotrophin/heparin binding growth-associated molecule
.
J. Biol. Chem.
278
,
35805
35811
148
Deepa
,
S.S.
,
Kalayanamitra
,
K.
,
Ito
,
Y.
,
Kongtawelert
,
P.
,
Fukui
,
S.
,
Yamada
,
S.
et al. 
(
2007
)
Novel sulfated octa- and decasaccharides from squid cartilage chondroitin sulfate E: sequencing and application for determination of the epitope structure of the monoclonal antibody MO-225
.
Biochemistry
46
,
2453
2465
149
Deepa
,
S.S.
,
Yamada
,
S.
,
Fukui
,
S.
and
Sugahara
,
K.
(
2007
)
Structural determination of novel sulfated octasaccharides isolated from chondroitin sulfate of shark cartilage and their application for characterizing monoclonal antibody epitopes
.
Glycobiology
17
,
631
645
150
Ito
,
Y.
,
Hikino
,
M.
,
Yajima
,
Y.
,
Mikami
,
T.
,
Sirko
,
S.
,
von Holst
,
A.
et al. 
(
2005
)
Structural characterization of the epitopes of the monoclonal antibodies 473HD, CS-56, and MO-225 specific for chondroitin sulfate D-type using the oligosaccharide library
.
Glycobiology
15
,
593
603
151
Dobbertin
,
A.
,
Rhodes
,
K.E.
,
Garwood
,
J.
,
Properzi
,
F.
,
Heck
,
N.
,
Rogers
,
J.H.
et al. 
(
2003
)
Regulation of RPTPβ/phosphacan expression and glycosaminoglycan epitopes in injured brain and cytokine-treated glia
.
Mol. Cell. Neurosci.
24
,
951
971
152
Faissner
,
A.
,
Heck
,
N.
,
Dobbertin
,
A.
and
Garwood
,
J.
(
2006
)
DSD-1-proteoglycan/phosphacan and receptor protein tyrosine phosphatase-beta isoforms during development and regeneration of neural tissues
.
Adv. Exp. Med. Biol.
557
,
25
53
153
Garwood
,
J.
,
Rigato
,
F.
,
Heck
,
N.
and
Faissner
,
A.
(
2001
)
Tenascin glycoproteins and the complementary ligand DSD-1-PG/phosphacan—structuring the neural extracellular matrix during development and repair
.
Restor. Neurol. Neurosci.
19
,
51
64
PMID:
[PubMed]
154
Garwood
,
J.
,
Schnadelbach
,
O.
,
Clement
,
A.
,
Schutte
,
K.
,
Bach
,
A.
and
Faissner
,
A.
(
1999
)
DSD-1-proteoglycan is the mouse homolog of phosphacan and displays opposing effects on neurite outgrowth dependent on neuronal lineage
.
J. Neurosci.
19
,
3888
3899
PMID:
[PubMed]
155
Margolis
,
R.U.
and
Margolis
,
R.K.
(
1997
)
Chondroitin sulfate proteoglycans as mediators of axon growth and pathfinding
.
Cell Tissue Res.
290
,
343
348
156
Hikino
,
M.
,
Mikami
,
T.
,
Faissner
,
A.
,
Vilela-Silva
,
A.C.
,
Pavao
,
M.S.
and
Sugahara
,
K.
(
2003
)
Oversulfated dermatan sulfate exhibits neurite outgrowth-promoting activity toward embryonic mouse hippocampal neurons: implications of dermatan sulfate in neuritogenesis in the brain
.
J. Biol. Chem.
278
,
43744
43754
157
Takano
,
M.
,
Mori
,
Y.
,
Shiraki
,
H.
,
Horie
,
M.
,
Okamoto
,
H.
,
Narahara
,
M.
et al. 
(
1999
)
Detection of bikunin mRNA in limited portions of rat brain
.
Life Sci.
65
,
757
762
158
Yoshida
,
K.
,
Suzuki
,
Y.
,
Yamamoto
,
K.
and
Sinohara
,
H.
(
1999
)
Guinea pig α1-microglobulin/bikunin: cDNA sequencing, tissue expression and expression during acute phase
.
Comp. Biochem. Physiol. B Biochem. Mol. Biol.
122
,
165
172
159
Yoshida
,
E.
,
Maruyama
,
M.
,
Sugiki
,
M.
and
Mihara
,
H.
(
1994
)
Immunohistochemical demonstration of bikunin, a light chain of inter-α-trypsin inhibitor, in human brain tumors
.
Inflammation
18
,
589
596
160
Pangalos
,
M.N.
,
Shioi
,
J.
and
Robakis
,
N.K.
(
1995
)
Expression of the chondroitin sulfate proteoglycans of amyloid precursor (appican) and amyloid precursor-like protein 2
.
J. Neurochem.
65
,
762
769
161
Shioi
,
J.
,
Pangalos
,
M.N.
,
Ripellino
,
J.A.
,
Vassilacopoulou
,
D.
,
Mytilineou
,
C.
,
Margolis
,
R.U.
et al. 
(
1995
)
The Alzheimer amyloid precursor proteoglycan (appican) is present in brain and is produced by astrocytes but not by neurons in primary neural cultures
.
J. Biol. Chem.
270
,
11839
11844
162
Kawamura
,
D.
,
Funakoshi
,
T.
,
Mizumoto
,
S.
,
Sugahara
,
K.
and
Iwasaki
,
N.
(
2014
)
Sulfation patterns of exogenous chondroitin sulfate affect chondrogenic differentiation of ATDC5 cells
.
J. Orthop. Sci.
19
,
1028
1035
163
Sia
,
G.M.
,
Clem
,
R.L.
and
Huganir
,
R.L.
(
2013
)
The human language-associated gene SRPX2 regulates synapse formation and vocalization in mice
.
Science
342
,
987
991
164
Royer-Zemmour
,
B.
,
Ponsole-Lenfant
,
M.
,
Gara
,
H.
,
Roll
,
P.
,
Leveque
,
C.
,
Massacrier
,
A.
et al. 
(
2008
)
Epileptic and developmental disorders of the speech cortex: ligand/receptor interaction of wild-type and mutant SRPX2 with the plasminogen activator receptor uPAR
.
Hum. Mol. Genet.
17
,
3617
3630
165
Bruneau
,
N.
and
Szepetowski
,
P.
(
2011
)
The role of the urokinase receptor in epilepsy, in disorders of language, cognition, communication and behavior, and in the central nervous system
.
Curr. Pharm. Des.
17
,
1914
1923
166
Spalice
,
A.
,
Parisi
,
P.
,
Nicita
,
F.
,
Pizzardi
,
G.
,
Del Balzo
,
F.
and
Iannetti
,
P.
(
2009
)
Neuronal migration disorders: clinical, neuroradiologic and genetics aspects
.
Acta Paediatr.
98
,
421
433
167
Archinti
,
M.
,
Britto
,
M.
,
Eden
,
G.
,
Furlan
,
F.
,
Murphy
,
R.
and
Degryse
,
B.
(
2011
)
The urokinase receptor in the central nervous system
.
CNS Neurol. Disord. Drug Targets
10
,
271
294
168
Lemarchant
,
S.
,
Pruvost
,
M.
,
Hebert
,
M.
,
Gauberti
,
M.
,
Hommet
,
Y.
,
Briens
,
A.
et al. 
(
2014
)
tPA promotes ADAMTS-4-induced CSPG degradation, thereby enhancing neuroplasticity following spinal cord injury
.
Neurobiol. Dis.
66
,
28
42
169
Tauchi
,
R.
,
Imagama
,
S.
,
Natori
,
T.
,
Ohgomori
,
T.
,
Muramoto
,
A.
,
Shinjo
,
R.
et al. 
(
2012
)
The endogenous proteoglycan-degrading enzyme ADAMTS-4 promotes functional recovery after spinal cord injury
.
J. Neuroinflammation
9
,
53
170
Roll
,
P.
,
Rudolf
,
G.
,
Pereira
,
S.
,
Royer
,
B.
,
Scheffer
,
I.E.
,
Massacrier
,
A.
et al. 
(
2006
)
SRPX2 mutations in disorders of language cortex and cognition
.
Hum. Mol. Genet.
15
,
1195
1207
171
Royer
,
B.
,
Soares
,
D.C.
,
Barlow
,
P.N.
,
Bontrop
,
R.E.
,
Roll
,
P.
,
Robaglia-Schlupp
,
A.
et al. 
(
2007
)
Molecular evolution of the human SRPX2 gene that causes brain disorders of the Rolandic and Sylvian speech areas
.
BMC Genet.
8
,
72
172
Soleman
,
S.
,
Filippov
,
M.A.
,
Dityatev
,
A.
and
Fawcett
,
J.W.
(
2013
)
Targeting the neural extracellular matrix in neurological disorders
.
Neuroscience
253
,
194
213
173
Nadanaka
,
S.
,
Clement
,
A.
,
Masayama
,
K.
,
Faissner
,
A.
and
Sugahara
,
K.
(
1998
)
Characteristic hexasaccharide sequences in octasaccharides derived from shark cartilage chondroitin sulfate D with a neurite outgrowth promoting activity
.
J. Biol. Chem.
273
,
3296
3307
174
Mizumoto
,
S.
,
Fongmoon
,
D.
and
Sugahara
,
K.
(
2013
)
Interaction of chondroitin sulfate and dermatan sulfate from various biological sources with heparin-binding growth factors and cytokines
.
Glycoconj. J.
30
,
619
632
175
Gu
,
W.L.
,
Fu
,
S.L.
,
Wang
,
Y.X.
,
Li
,
Y.
,
Lu
,
H.Z.
,
Xu
,
X.M.
et al. 
(
2009
)
Chondroitin sulfate proteoglycans regulate the growth, differentiation and migration of multipotent neural precursor cells through the integrin signaling pathway
.
BMC Neurosci.
10
,
128
176
Sirko
,
S.
,
von Holst
,
A.
,
Weber
,
A.
,
Wizenmann
,
A.
,
Theocharidis
,
U.
,
Gotz
,
M.
et al. 
(
2010
)
Chondroitin sulfates are required for fibroblast growth factor-2-dependent proliferation and maintenance in neural stem cells and for epidermal growth factor-dependent migration of their progeny
.
Stem Cells
28
,
775
787
177
Sirko
,
S.
,
von Holst
,
A.
,
Wizenmann
,
A.
,
Gotz
,
M.
and
Faissner
,
A.
(
2007
)
Chondroitin sulfate glycosaminoglycans control proliferation, radial glia cell differentiation and neurogenesis in neural stem/progenitor cells
.
Development
134
,
2727
2738
178
Pyka
,
M.
,
Wetzel
,
C.
,
Aguado
,
A.
,
Geissler
,
M.
,
Hatt
,
H.
and
Faissner
,
A.
(
2011
)
Chondroitin sulfate proteoglycans regulate astrocyte-dependent synaptogenesis and modulate synaptic activity in primary embryonic hippocampal neurons
.
Eur. J. Neurosci.
33
,
2187
2202
179
Properzi
,
F.
,
Carulli
,
D.
,
Asher
,
R.A.
,
Muir
,
E.
,
Camargo
,
L.M.
,
van Kuppevelt
,
T.H.
et al. 
(
2005
)
Chondroitin 6-sulphate synthesis is up-regulated in injured CNS, induced by injury-related cytokines and enhanced in axon-growth inhibitory glia
.
Eur. J. Neurosci.
21
,
378
390
180
Silver
,
J.
and
Miller
,
J.H.
(
2004
)
Regeneration beyond the glial scar
.
Nat. Rev. Neurosci.
5
,
146
156
181
Slater
, Jr,
R.R.
,
Bayliss
,
M.T.
,
Lachiewicz
,
P.F.
,
Visco
,
D.M.
and
Caterson
,
B.
(
1995
)
Monoclonal antibodies that detect biochemical markers of arthritis in humans
.
Arthritis Rheum.
38
,
655
659
182
Visco
,
D.M.
,
Johnstone
,
B.
,
Hill
,
M.A.
,
Jolly
,
G.A.
and
Caterson
,
B.
(
1993
)
Immunohistochemical analysis of 3-B-(−) and 7-D-4 epitope expression in canine osteoarthritis
.
Arthritis Rheum.
36
,
1718
1725
183
Brown
,
S.
,
Matta
,
A.
,
Erwin
,
W.M.
,
Roberts
,
S.
,
Gruber
,
H.H.
,
Hanley
,
E.N.
et al. 
(
2018
)
Cell clusters are indicative of stem cell activity in the degenerate intervertebral disc: can their properties be manipulated to improve intrinsic repair of the disc?
Stem Cells Dev.
184
Tesche
,
F.
and
Miosge
,
N.
(
2004
)
Perlecan in late stages of osteoarthritis of the human knee joint
.
Osteoarthr. Cartil.
12
,
852
862
185
Tesche
,
F.
and
Miosge
,
N.
(
2005
)
New aspects of the pathogenesis of osteoarthritis: the role of fibroblast-like chondrocytes in late stages of the disease
.
Histol. Histopathol.
20
,
329
337
186
Smith
,
S.
and
Melrose
,
J.
(
2016
)
Perlecan delineates stem cell niches in human foetal hip, knee and elbow cartilage rudiments and has potential roles in the regulation of stem cell differentiation
.
J. Stem Cell Res. Dev. Ther.
3
,
9
16
187
Akatsu
,
C.
,
Mizumoto
,
S.
,
Kaneiwa
,
T.
,
Maccarana
,
M.
,
Malmstrom
,
A.
,
Yamada
,
S.
et al. 
(
2011
)
Dermatan sulfate epimerase 2 is the predominant isozyme in the formation of the chondroitin sulfate/dermatan sulfate hybrid structure in postnatal developing mouse brain
.
Glycobiology
21
,
565
574
188
Akita
,
K.
,
von Holst
,
A.
,
Furukawa
,
Y.
,
Mikami
,
T.
,
Sugahara
,
K.
and
Faissner
,
A.
(
2008
)
Expression of multiple chondroitin/dermatan sulfotransferases in the neurogenic regions of the embryonic and adult central nervous system implies that complex chondroitin sulfates have a role in neural stem cell maintenance
.
Stem Cells
26
,
798
809
189
Mitsunaga
,
C.
,
Mikami
,
T.
,
Mizumoto
,
S.
,
Fukuda
,
J.
and
Sugahara
,
K.
(
2006
)
Chondroitin sulfate/dermatan sulfate hybrid chains in the development of cerebellum. Spatiotemporal regulation of the expression of critical disulfated disaccharides by specific sulfotransferases
.
J. Biol. Chem.
281
,
18942
18952
190
Hiraoka
,
K.
,
Grogan
,
S.
,
Olee
,
T.
and
Lotz
,
M.
(
2006
)
Mesenchymal progenitor cells in adult human articular cartilage
.
Biorheology
43
,
447
454
PMID:
[PubMed]
191
Hayes
,
A.J.
,
Dowthwaite
,
G.P.
,
Webster
,
S.V.
and
Archer
,
C.W.
(
2003
)
The distribution of Notch receptors and their ligands during articular cartilage development
.
J. Anat.
202
,
495
502
192
Garcia-Suarez
,
O.
,
Garcia
,
B.
,
Fernandez-Vega
,
I.
,
Astudillo
,
A.
and
Quiros
,
L.M.
(
2014
)
Neuroendocrine tumors show altered expression of chondroitin sulfate, glypican 1, glypican 5, and syndecan 2 depending on their differentiation grade
.
Front. Oncol.
4
,
15
193
Baghy
,
K.
,
Tatrai
,
P.
,
Regos
,
E.
and
Kovalszky
,
I.
(
2016
)
Proteoglycans in liver cancer
.
World J. Gastroenterol.
22
,
379
393
194
Ucakturk
,
E.
,
Akman
,
O.
,
Sun
,
X.
,
Baydar
,
D.E.
,
Dolgun
,
A.
,
Zhang
,
F.
et al. 
(
2016
)
Changes in composition and sulfation patterns of glycoaminoglycans in renal cell carcinoma
.
Glycoconj. J.
33
,
103
112
195
Jia
,
X.L.
,
Li
,
S.Y.
,
Dang
,
S.S.
,
Cheng
,
Y.A.
,
Zhang
,
X.
,
Wang
,
W.J.
et al. 
(
2012
)
Increased expression of chondroitin sulphate proteoglycans in rat hepatocellular carcinoma tissues
.
World J. Gastroenterol.
18
,
3962
3976
196
Lv
,
H.
,
Yu
,
G.
,
Sun
,
L.
,
Zhang
,
Z.
,
Zhao
,
X.
and
Chai
,
W.
(
2007
)
Elevate level of glycosaminoglycans and altered sulfation pattern of chondroitin sulfate are associated with differentiation status and histological type of human primary hepatic carcinoma
.
Oncology
72
,
347
356
197
Theocharis
,
A.D.
,
Vynios
,
D.H.
,
Papageorgakopoulou
,
N.
,
Skandalis
,
S.S.
and
Theocharis
,
D.A.
(
2003
)
Altered content composition and structure of glycosaminoglycans and proteoglycans in gastric carcinoma
.
Int. J. Biochem. Cell Biol.
35
,
376
390
198
Skandalis
,
S.S.
,
Kletsas
,
D.
,
Kyriakopoulou
,
D.
,
Stavropoulos
,
M.
and
Theocharis
,
D.A.
(
2006
)
The greatly increased amounts of accumulated versican and decorin with specific post-translational modifications may be closely associated with the malignant phenotype of pancreatic cancer
.
Biochim. Biophys. Acta
1760
,
1217
1225
199
Hinrichs
,
U.
,
Rutteman
,
G.R.
and
Nederbragt
,
H.
(
1999
)
Stromal accumulation of chondroitin sulphate in mammary tumours of dogs
.
Br. J. Cancer.
80
,
1359
1365
200
Viola
,
M.
,
Bruggemann
,
K.
,
Karousou
,
E.
,
Caon
,
I.
,
Carava
,
E.
,
Vigetti
,
D.
et al. 
(
2017
)
MDA-MB-231 breast cancer cell viability, motility and matrix adhesion are regulated by a complex interplay of heparan sulfate, chondroitin/dermatan sulfate and hyaluronan biosynthesis
.
Glycoconj. J.
34
,
411
420
201
van der Steen
,
S.C.
,
van Tilborg
,
A.A.
,
Vallen
,
M.J.
,
Bulten
,
J.
,
van Kuppevelt
,
T.H.
and
Massuger
,
L.F.
(
2016
)
Prognostic significance of highly sulfated chondroitin sulfates in ovarian cancer defined by the single chain antibody GD3A11
.
Gynecol. Oncol.
140
,
527
536
202
Pothacharoen
,
P.
,
Siriaunkgul
,
S.
,
Ong-Chai
,
S.
,
Supabandhu
,
J.
,
Kumja
,
P.
,
Wanaphirak
,
C.
et al. 
(
2006
)
Raised serum chondroitin sulfate epitope level in ovarian epithelial cancer
.
J. Biochem.
140
,
517
524
203
Takakura
,
K.
,
Shibazaki
,
Y.
,
Yoneyama
,
H.
,
Fujii
,
M.
,
Hashiguchi
,
T.
,
Ito
,
Z.
et al. 
(
2015
)
Inhibition of cell proliferation and growth of pancreatic cancer by silencing of carbohydrate sulfotransferase 15 in vitro and in a xenograft model
.
PLoS ONE
10
,
e0142981
204
ten Dam
,
G.B.
,
van de Westerlo
,
E.M.
,
Purushothaman
,
A.
,
Stan
,
R.V.
,
Bulten
,
J.
,
Sweep
,
F.C.
et al. 
(
2007
)
Antibody GD3G7 selected against embryonic glycosaminoglycans defines chondroitin sulfate-E domains highly up-regulated in ovarian cancer and involved in vascular endothelial growth factor binding
.
Am. J. Pathol.
171
,
1324
1333
205
Marolla
,
A.P.
,
Waisberg
,
J.
,
Saba
,
G.T.
,
Waisberg
,
D.R.
,
Margeotto
,
F.B.
and
Pinhal
,
M.A
. (
2015
)
Glycomics expression analysis of sulfated glycosaminoglycans of human colorectal cancer tissues and non-neoplastic mucosa by electrospray ionization mass spectrometry
.
Einstein
13
,
510
517
206
Iida
,
J.
,
Dorchak
,
J.
,
Clancy
,
R.
,
Slavik
,
J.
,
Ellsworth
,
R.
,
Katagiri
,
Y.
et al. 
(
2015
)
Role for chondroitin sulfate glycosaminoglycan in NEDD9-mediated breast cancer cell growth
.
Exp. Cell Res.
330
,
358
370
207
Basappa
,
Murugan
,
S.
,
Sugahara
,
K.N.
,
Lee
,
C.M.
,
ten Dam
,
G.B.
,
van Kuppevelt
,
T.H.
et al. 
(
2009
)
Involvement of chondroitin sulfate E in the liver tumor focal formation of murine osteosarcoma cells
.
Glycobiology
19
,
735
742
208
Basappa
,
Rangappa
,
K.S.
and
Sugahara
,
K.
(
2014
)
Roles of glycosaminoglycans and glycanmimetics in tumor progression and metastasis
.
Glycoconj. J.
31
,
461
467
209
Purushothaman
,
A.
and
Toole
,
B.P.
(
2014
)
Serglycin proteoglycan is required for multiple myeloma cell adhesion, in vivo growth, and vascularization
.
J. Biol. Chem.
289
,
5499
5509
210
Korpetinou
,
A.
,
Skandalis
,
S.S.
,
Labropoulou
,
V.T.
,
Smirlaki
,
G.
,
Noulas
,
A.
,
Karamanos
,
N.K.
et al. 
(
2014
)
Serglycin: at the crossroad of inflammation and malignancy
.
Front. Oncol.
3
,
327
211
Du
,
W.W.
,
Yang
,
W.
and
Yee
,
A.J.
(
2013
)
Roles of versican in cancer biology—tumorigenesis, progression and metastasis
.
Histol. Histopathol.
28
,
701
713
212
Xiang
,
Y.Y.
,
Dong
,
H.
,
Wan
,
Y.
,
Li
,
J.
,
Yee
,
A.
,
Yang
,
B.B.
et al. 
(
2006
)
Versican G3 domain regulates neurite growth and synaptic transmission of hippocampal neurons by activation of epidermal growth factor receptor
.
J. Biol. Chem.
281
,
19358
19368
213
Dutt
,
S.
,
Kleber
,
M.
,
Matasci
,
M.
,
Sommer
,
L.
and
Zimmermann
,
D.R.
(
2006
)
Versican V0 and V1 guide migratory neural crest cells
.
J. Biol. Chem.
281
,
12123
12131
214
Touab
,
M.
,
Villena
,
J.
,
Barranco
,
C.
,
Arumi-Uria
,
M.
and
Bassols
,
A.
(
2002
)
Versican is differentially expressed in human melanoma and may play a role in tumor development
.
Am. J. Pathol.
160
,
549
557
215
Zheng
,
P.S.
,
Wen
,
J.
,
Ang
,
L.C.
,
Sheng
,
W.
,
Viloria-Petit
,
A.
,
Wang
,
Y.
et al. 
(
2004
)
Versican/PG-M G3 domain promotes tumor growth and angiogenesis
.
FASEB J.
18
,
754
756
PMID:
[PubMed]
216
Fedorchenko
,
O.
,
Stiefelhagen
,
M.
,
Peer-Zada
,
A.A.
,
Barthel
,
R.
,
Mayer
,
P.
,
Eckei
,
L.
et al. 
(
2013
)
CD44 regulates the apoptotic response and promotes disease development in chronic lymphocytic leukemia
.
Blood
121
,
4126
4136
217
Prinz
,
R.D.
,
Willis
,
C.M.
,
Viloria-Petit
,
A.
and
Kluppel
,
M.
(
2011
)
Elimination of breast tumor-associated chondroitin sulfate promotes metastasis
.
Genet. Mol. Res.
10
,
3901
3913
218
Schowalter
,
R.M.
,
Pastrana
,
D.V.
and
Buck
,
C.B.
(
2011
)
Glycosaminoglycans and sialylated glycans sequentially facilitate Merkel cell polyomavirus infectious entry
.
PLoS Pathog.
7
,
e1002161
219
Cooney
,
C.A.
,
Jousheghany
,
F.
,
Yao-Borengasser
,
A.
,
Phanavanh
,
B.
,
Gomes
,
T.
,
Kieber-Emmons
,
A.M.
et al. 
(
2011
)
Chondroitin sulfates play a major role in breast cancer metastasis: a role for CSPG4 and CHST11 gene expression in forming surface P-selectin ligands in aggressive breast cancer cells
.
Breast Cancer Res.
13
,
R58
220
Monzavi-Karbassi
,
B.
,
Stanley
,
J.S.
,
Hennings
,
L.
,
Jousheghany
,
F.
,
Artaud
,
C.
,
Shaaf
,
S.
et al. 
(
2007
)
Chondroitin sulfate glycosaminoglycans as major P-selectin ligands on metastatic breast cancer cell lines
.
Int. J. Cancer
120
,
1179
1191
221
Amoury
,
M.
,
Mladenov
,
R.
,
Nachreiner
,
T.
,
Pham
,
A.T.
,
Hristodorov
,
D.
,
Di Fiore
,
S.
et al. 
(
2016
)
A novel approach for targeted elimination of CSPG4-positive triple-negative breast cancer cells using a MAP tau-based fusion protein
.
Int. J. Cancer
139
,
916
927
222
Wang
,
Y.
,
Geldres
,
C.
,
Ferrone
,
S.
and
Dotti
,
G.
(
2015
)
Chondroitin sulfate proteoglycan 4 as a target for chimeric antigen receptor-based T-cell immunotherapy of solid tumors
.
Expert Opin. Ther. Targets
19
,
1339
1350
223
Beard
,
R.E.
,
Zheng
,
Z.
,
Lagisetty
,
K.H.
,
Burns
,
W.R.
,
Tran
,
E.
,
Hewitt
,
S.M.
et al. 
(
2014
)
Multiple chimeric antigen receptors successfully target chondroitin sulfate proteoglycan 4 in several different cancer histologies and cancer stem cells
.
J. Immunother. Cancer
2
,
25
224
Wang
,
X.
,
Osada
,
T.
,
Wang
,
Y.
,
Yu
,
L.
,
Sakakura
,
K.
,
Katayama
,
A.
et al. 
(
2010
)
CSPG4 protein as a new target for the antibody-based immunotherapy of triple-negative breast cancer
.
J. Natl Cancer Inst.
102
,
1496
1512
225
Brehm
,
H.
,
Niesen
,
J.
,
Mladenov
,
R.
,
Stein
,
C.
,
Pardo
,
A.
,
Fey
,
G.
et al. 
(
2014
)
A CSPG4-specific immunotoxin kills rhabdomyosarcoma cells and binds to primary tumor tissues
.
Cancer Lett.
352
,
228
235
226
Mizumoto
,
S.
,
Yamada
,
S.
and
Sugahara
,
K.
(
2015
)
Molecular interactions between chondroitin-dermatan sulfate and growth factors/receptors/matrix proteins
.
Curr. Opin. Struct. Biol.
34
,
35
42
227
Yu
,
L.
,
Favoino
,
E.
,
Wang
,
Y.
,
Ma
,
Y.
,
Deng
,
X.
and
Wang
,
X.
(
2011
)
The CSPG4-specific monoclonal antibody enhances and prolongs the effects of the BRAF inhibitor in melanoma cells
.
Immunol. Res.
50
,
294
302
228
Sorrell
,
J.M.
,
Mahmoodian
,
F.
,
Schafer
,
I.A.
,
Davis
,
B.
and
Caterson
,
B.
(
1990
)
Identification of monoclonal antibodies that recognize novel epitopes in native chondroitin/dermatan sulfate glycosaminoglycan chains: their use in mapping functionally distinct domains of human skin
.
J. Histochem. Cytochem.
38
,
393
402
229
Caterson
,
B.
,
Mahmoodian
,
F.
,
Sorrell
,
J.M.
,
Hardingham
,
T.E.
,
Bayliss
,
M.T.
,
Carney
,
S.L.
et al. 
(
1990
)
Modulation of native chondroitin sulphate structure in tissue development and in disease
.
J. Cell Sci.
97
(
Pt 3
),
411
417
230
Hayes
,
A.J.
,
Benjamin
,
M.
and
Ralphs
,
J.R.
(
2001
)
Extracellular matrix in development of the intervertebral disc
.
Matrix Biol.
20
,
107
121
231
Sorrell
,
J.M.
,
Lintala
,
A.M.
,
Mahmoodian
,
F.
and
Caterson
,
B.
(
1988
)
Epitope-specific changes in chondroitin sulfate/dermatan sulfate proteoglycans as markers in the lymphopoietic and granulopoietic compartments of developing bursae of Fabricius
.
J. Immunol.
140
,
4263
4270
232
Rhodes
,
K.E.
and
Fawcett
,
J.W.
(
2004
)
Chondroitin sulphate proteoglycans: preventing plasticity or protecting the CNS?
J. Anat.
204
,
33
48
233
Melrose
,
J.
,
Chuang
,
C.
and
Whitelock
,
J.
(
2008
)
Tissue engineering of cartilages using biomatrices
.
J. Chem. Technol. Biotechnol.
83
,
444
463
234
Abbadessa
,
A.
,
Blokzijl
,
M.M.
,
Mouser
,
V.H.
,
Marica
,
P.
,
Malda
,
J.
,
Hennink
,
W.E.
et al. 
(
2016
)
A thermo-responsive and photo-polymerizable chondroitin sulfate-based hydrogel for 3D printing applications
.
Carbohydr. Polym.
149
,
163
174
235
Fan
,
M.
,
Ma
,
Y.
,
Tan
,
H.
,
Jia
,
Y.
,
Zou
,
S.
,
Guo
,
S.
et al. 
(
2017
)
Covalent and injectable chitosan-chondroitin sulfate hydrogels embedded with chitosan microspheres for drug delivery and tissue engineering
.
Mater. Sci. Eng. C Mater. Biol. Appl.
71
,
67
74
236
Gupta
,
V.
,
Tenny
,
K.M.
,
Barragan
,
M.
,
Berkland
,
C.J.
and
Detamore
,
M.S.
(
2016
)
Microsphere-based scaffolds encapsulating chondroitin sulfate or decellularized cartilage
.
J. Biomater. Appl.
31
,
328
343
237
Xu
,
H.
,
Yan
,
Y.
and
Li
,
S.
(
2011
)
PDLLA/chondroitin sulfate/chitosan/NGF conduits for peripheral nerve regeneration
.
Biomaterials
32
,
4506
4516
238
Corradetti
,
B.
,
Taraballi
,
F.
,
Minardi
,
S.
,
Van Eps
,
J.
,
Cabrera
,
F.
,
Francis
,
L.W.
et al. 
(
2016
)
Chondroitin sulfate immobilized on a biomimetic scaffold modulates inflammation while driving chondrogenesis
.
Stem Cells Transl. Med.
5
,
670
682
239
Bhattacharjee
,
M.
,
Chawla
,
S.
,
Chameettachal
,
S.
,
Murab
,
S.
,
Bhavesh
,
N.S.
and
Ghosh
,
S.
(
2016
)
Role of chondroitin sulphate tethered silk scaffold in cartilaginous disc tissue regeneration
.
Biomed. Mater.
11
,
025014
240
Sawatjui
,
N.
,
Damrongrungruang
,
T.
,
Leeanansaksiri
,
W.
,
Jearanaikoon
,
P.
,
Hongeng
,
S.
and
Limpaiboon
,
T.
(
2015
)
Silk fibroin/gelatin-chondroitin sulfate-hyaluronic acid effectively enhances in vitro chondrogenesis of bone marrow mesenchymal stem cells
.
Mater. Sci. Eng. C Mater. Biol. Appl.
52
,
90
96
241
Huang
,
Z.
,
Nooeaid
,
P.
,
Kohl
,
B.
,
Roether
,
J.A.
,
Schubert
,
D.W.
,
Meier
,
C.
et al. 
(
2015
)
Chondrogenesis of human bone marrow mesenchymal stromal cells in highly porous alginate-foams supplemented with chondroitin sulfate
.
Mater. Sci. Eng. C Mater. Biol. Appl.
50
,
160
172
242
Kuo
,
C.Y.
,
Chen
,
C.H.
,
Hsiao
,
C.Y.
and
Chen
,
J.P.
(
2015
)
Incorporation of chitosan in biomimetic gelatin/chondroitin-6-sulfate/hyaluronan cryogel for cartilage tissue engineering
.
Carbohydr. Polym.
117
,
722
730
243
Ni
,
Y.
,
Tang
,
Z.
,
Cao
,
W.
,
Lin
,
H.
,
Fan
,
Y.
,
Guo
,
L.
et al. 
(
2015
)
Tough and elastic hydrogel of hyaluronic acid and chondroitin sulfate as potential cell scaffold materials
.
Int. J. Biol. Macromol.
74
,
367
375
244
Hortensius
,
R.A.
and
Harley
,
B.A.
(
2013
)
The use of bioinspired alterations in the glycosaminoglycan content of collagen-GAG scaffolds to regulate cell activity
.
Biomaterials
34
,
7645
7652
245
Silva
,
J.M.
,
Georgi
,
N.
,
Costa
,
R.
,
Sher
,
P.
,
Reis
,
R.L.
,
Van Blitterswijk
,
C.A.
et al. 
(
2013
)
Nanostructured 3D constructs based on chitosan and chondroitin sulphate multilayers for cartilage tissue engineering
.
PLoS ONE
8
,
e55451
246
Sun
,
L.
,
Li
,
H.
,
Qu
,
L.
,
Zhu
,
R.
,
Fan
,
X.
,
Xue
,
Y.
et al. 
(
2014
)
Immobilized lentivirus vector on chondroitin sulfate-hyaluronate acid-silk fibroin hybrid scaffold for tissue-engineered ligament-bone junction
.
Biomed. Res. Int.
2014
,
816979
247
Chen
,
W.C.
,
Wei
,
Y.H.
,
Chu
,
I.M.
and
Yao
,
C.L.
(
2013
)
Effect of chondroitin sulphate C on the in vitro and in vivo chondrogenesis of mesenchymal stem cells in crosslinked type II collagen scaffolds
.
J. Tissue Eng. Regen. Med.
7
,
665
672
248
Guo
,
Y.
,
Yuan
,
T.
,
Xiao
,
Z.
,
Tang
,
P.
,
Xiao
,
Y.
,
Fan
,
Y.
et al. 
(
2012
)
Hydrogels of collagen/chondroitin sulfate/hyaluronan interpenetrating polymer network for cartilage tissue engineering
.
J. Mater. Sci. Mater. Med.
23
,
2267
2279
249
Tamaddon
,
M.
,
Walton
,
R.S.
,
Brand
,
D.D.
and
Czernuszka
,
J.T.
(
2013
)
Characterisation of freeze-dried type II collagen and chondroitin sulfate scaffolds
.
J. Mater. Sci. Mater. Med.
24
,
1153
1165
250
Fan
,
H.
,
Tao
,
H.
,
Wu
,
Y.
,
Hu
,
Y.
,
Yan
,
Y.
and
Luo
,
Z.
(
2010
)
TGF-β3 immobilized PLGA-gelatin/chondroitin sulfate/hyaluronic acid hybrid scaffold for cartilage regeneration
.
J. Biomed. Mater. Res. A
95
,
982
992
251
Park
,
J.S.
,
Yang
,
H.J.
,
Woo
,
D.G.
,
Yang
,
H.N.
,
Na
,
K.
and
Park
,
K.H.
(
2010
)
Chondrogenic differentiation of mesenchymal stem cells embedded in a scaffold by long-term release of TGF-beta 3 complexed with chondroitin sulfate
.
J. Biomed. Mater. Res. A
92
,
806
816
252
Farrugia
,
B.L.
,
Whitelock
,
J.M.
,
Jung
,
M.
,
McGrath
,
B.
,
O'Grady
,
R.L.
,
McCarthy
,
S.J.
et al. 
(
2014
)
The localisation of inflammatory cells and expression of associated proteoglycans in response to implanted chitosan
.
Biomaterials
35
,
1462
1477
253
Asari
,
A.
,
Akizaki
,
S.
,
Itoh
,
T.
,
Kominami
,
E.
and
Uchiyama
,
Y.
(
1996
)
Human osteoarthritic cartilage exhibits the 2B6 epitope without pretreatment with chondroitinase ABC
.
Osteoarthr. Cartil.
4
,
149
152
254
Kaneiwa
,
T.
,
Miyazaki
,
A.
,
Kogawa
,
R.
,
Mizumoto
,
S.
,
Sugahara
,
K.
and
Yamada
,
S.
(
2012
)
Identification of amino acid residues required for the substrate specificity of human and mouse chondroitin sulfate hydrolase (conventional hyaluronidase-4)
.
J. Biol. Chem.
287
,
42119
42128
255
Kaneiwa
,
T.
,
Mizumoto
,
S.
,
Sugahara
,
K.
and
Yamada
,
S.
(
2010
)
Identification of human hyaluronidase-4 as a novel chondroitin sulfate hydrolase that preferentially cleaves the galactosaminidic linkage in the trisulfated tetrasaccharide sequence
.
Glycobiology
20
,
300
309
256
Bao
,
X.
,
Muramatsu
,
T.
and
Sugahara
,
K.
(
2005
)
Demonstration of the pleiotrophin-binding oligosaccharide sequences isolated from chondroitin sulfate/dermatan sulfate hybrid chains of embryonic pig brains
.
J. Biol. Chem.
280
,
35318
35328
257
Bao
,
X.
,
Nishimura
,
S.
,
Mikami
,
T.
,
Yamada
,
S.
,
Itoh
,
N.
and
Sugahara
,
K.
(
2004
)
Chondroitin sulfate/dermatan sulfate hybrid chains from embryonic pig brain, which contain a higher proportion of L-iduronic acid than those from adult pig brain, exhibit neuritogenic and growth factor binding activities
.
J. Biol. Chem.
279
,
9765
9776
258
Maimone
,
M.M.
and
Tollefsen
,
D.M.
(
1991
)
Structure of a dermatan sulfate hexasaccharide that binds to heparin cofactor II with high affinity
.
J. Biol. Chem.
266
,
14830
PMID:
[PubMed]
259
Bartolini
,
B.
,
Thelin
,
M.A.
,
Svensson
,
L.
,
Ghiselli
,
G.
,
van Kuppevelt
,
T.H.
,
Malmstrom
,
A.
et al. 
(
2013
)
Iduronic acid in chondroitin/dermatan sulfate affects directional migration of aortic smooth muscle cells
.
PLoS ONE
8
,
e66704
260
Thelin
,
M.A.
,
Bartolini
,
B.
,
Axelsson
,
J.
,
Gustafsson
,
R.
,
Tykesson
,
E.
,
Pera
,
E.
et al. 
(
2013
)
Biological functions of iduronic acid in chondroitin/dermatan sulfate
.
FEBS J.
280
,
2431
2446
261
Bishop
,
J.R.
,
Schuksz
,
M.
and
Esko
,
J.D.
(
2007
)
Heparan sulphate proteoglycans fine-tune mammalian physiology
.
Nature
446
,
1030
1037
262
Dickendesher
,
T.L.
,
Baldwin
,
K.T.
,
Mironova
,
Y.A.
,
Koriyama
,
Y.
,
Raiker
,
S.J.
,
Askew
,
K.L.
et al. 
(
2012
)
Ngr1 and NgR3 are receptors for chondroitin sulfate proteoglycans
.
Nat. Neurosci.
15
,
703
712
263
Chen
,
T.
,
Yuan
,
D.
,
Wei
,
B.
,
Jiang
,
J.
,
Kang
,
J.
,
Ling
,
K.
et al. 
(
2010
)
E-cadherin-mediated cell-cell contact is critical for induced pluripotent stem cell generation
.
Stem Cells
28
,
1315
1325
264
Larue
,
L.
,
Antos
,
C.
,
Butz
,
S.
,
Huber
,
O.
,
Delmas
,
V.
,
Dominis
,
M.
et al. 
(
1996
)
A role for cadherins in tissue formation
.
Development
122
,
3185
3194
PMID:
[PubMed]
265
Larue
,
L.
,
Ohsugi
,
M.
,
Hirchenhain
,
J.
and
Kemler
,
R.
(
1994
)
E-cadherin null mutant embryos fail to form a trophectoderm epithelium
.
Proc. Natl Acad. Sci. U.S.A.
91
,
8263
8267
266
Redmer
,
T.
,
Diecke
,
S.
,
Grigoryan
,
T.
,
Quiroga-Negreira
,
A.
,
Birchmeier
,
W.
and
Besser
,
D.
(
2011
)
E-cadherin is crucial for embryonic stem cell pluripotency and can replace OCT4 during somatic cell reprogramming
.
EMBO Rep.
12
,
720
726
267
Zaidel-Bar
,
R.
(
2013
)
Cadherin adhesome at a glance
.
J. Cell Sci.
126
,
373
378
268
Bhatt
,
T.
,
Rizvi
,
A.
,
Batta
,
S.P.
,
Kataria
,
S.
and
Jamora
,
C.
(
2013
)
Signaling and mechanical roles of E-cadherin
.
Cell Commun. Adhes.
20
,
189
199
269
Huveneers
,
S.
and
de Rooij
,
J.
(
2013
)
Mechanosensitive systems at the cadherin-F-actin interface
.
J. Cell Sci.
126
,
403
413
270
Katoh
,
M.
(
2006
)
Cross-talk of WNT and FGF signaling pathways at GSK3β to regulate β-catenin and SNAIL signaling cascades
.
Cancer Biol. Ther.
5
,
1059
1064
271
Nelson
,
W.J.
and
Nusse
,
R.
(
2004
)
Convergence of Wnt, β-catenin, and cadherin pathways
.
Science
303
,
1483
1487
272
Stepniak
,
E.
,
Radice
,
G.L.
and
Vasioukhin
,
V.
(
2009
)
Adhesive and signaling functions of cadherins and catenins in vertebrate development
.
Cold Spring Harb. Perspect. Biol.
1
,
a002949
273
Sugahara
,
K.
and
Mikami
,
T.
(
2007
)
Chondroitin/dermatan sulfate in the central nervous system
.
Curr. Opin. Struct. Biol.
17
,
536
545
274
Nadanaka
,
S.
,
Kinouchi
,
H.
,
Taniguchi-Morita
,
K.
,
Tamura
,
J.
and
Kitagawa
,
H.
(
2011
)
Down-regulation of chondroitin 4-O-sulfotransferase-1 by Wnt signaling triggers diffusion of Wnt-3a
.
J. Biol. Chem.
286
,
4199
4208
275
Prinz
,
R.D.
,
Willis
,
C.M.
,
van Kuppevelt
,
T.H.
and
Kluppel
,
M.
(
2014
)
Biphasic role of chondroitin sulfate in cardiac differentiation of embryonic stem cells through inhibition of Wnt/β-catenin signaling
.
PLoS ONE
9
,
e92381
276
Willis
,
C.M.
and
Kluppel
,
M.
(
2014
)
Chondroitin sulfate-E is a negative regulator of a pro-tumorigenic Wnt/beta-catenin-Collagen 1 axis in breast cancer cells
.
PLoS ONE
9
,
e103966
277
Mizumoto
,
S.
and
Sugahara
,
K.
(
2013
)
Glycosaminoglycans are functional ligands for receptor for advanced glycation end-products in tumors
.
FEBS J.
280
,
2462
2470
278
Theocharis
,
A.D.
,
Gialeli
,
C.
,
Bouris
,
P.
,
Giannopoulou
,
E.
,
Skandalis
,
S.S.
,
Aletras
,
A.J.
et al. 
(
2014
)
Cell-matrix interactions: focus on proteoglycan-proteinase interplay and pharmacological targeting in cancer
.
FEBS J.
281
,
5023
5042
279
Sugahara
,
K.N.
,
Hirata
,
T.
,
Tanaka
,
T.
,
Ogino
,
S.
,
Takeda
,
M.
,
Terasawa
,
H.
et al. 
(
2008
)
Chondroitin sulfate E fragments enhance CD44 cleavage and CD44-dependent motility in tumor cells
.
Cancer Res.
68
,
7191
7199
280
Vallen
,
M.J.
,
Massuger
,
L.F.
,
ten Dam
,
G.B.
,
Bulten
,
J.
and
van Kuppevelt
,
T.H.
(
2012
)
Highly sulfated chondroitin sulfates, a novel class of prognostic biomarkers in ovarian cancer tissue
.
Gynecol. Oncol.
127
,
202
209
281
Li
,
F.
,
Ten Dam
,
G.B.
,
Murugan
,
S.
,
Yamada
,
S.
,
Hashiguchi
,
T.
,
Mizumoto
,
S.
et al. 
(
2008
)
Involvement of highly sulfated chondroitin sulfate in the metastasis of the Lewis lung carcinoma cells
.
J. Biol. Chem.
283
,
34294
34304
282
Mizumoto
,
S.
,
Takahashi
,
J.
and
Sugahara
,
K.
(
2012
)
Receptor for advanced glycation end products (RAGE) functions as receptor for specific sulfated glycosaminoglycans, and anti-RAGE antibody or sulfated glycosaminoglycans delivered in vivo inhibit pulmonary metastasis of tumor cells
.
J. Biol. Chem.
287
,
18985
18994
283
Kiani
,
C.
,
Chen
,
L.
,
Wu
,
Y.J.
,
Yee
,
A.J.
and
Yang
,
B.B.
(
2002
)
Structure and function of aggrecan
.
Cell Res.
12
,
19
32
284
Roughley
,
P.J.
and
Mort
,
J.S.
(
2014
)
The role of aggrecan in normal and osteoarthritic cartilage
.
J. Exp. Orthop.
1
,
8
285
Aspberg
,
A.
,
Miura
,
R.
,
Bourdoulous
,
S.
,
Shimonaka
,
M.
,
Heinegard
,
D.
,
Schachner
,
M.
et al. 
(
1997
)
The C-type lectin domains of lecticans, a family of aggregating chondroitin sulfate proteoglycans, bind tenascin-R by protein-protein interactions independent of carbohydrate moiety
.
Proc. Natl Acad. Sci. U.S.A.
94
,
10116
10121
286
Wight
,
T.N.
(
2002
)
Versican: a versatile extracellular matrix proteoglycan in cell biology
.
Curr. Opin. Cell Biol.
14
,
617
623
287
Wu
,
Y.J.
,
La Pierre
,
D.P.
,
Wu
,
J.
,
Yee
,
A.J.
and
Yang
,
B.B.
(
2005
)
The interaction of versican with its binding partners
.
Cell Res.
15
,
483
494
288
Rauch
,
U.
,
Feng
,
K.
and
Zhou
,
X.H.
(
2001
)
Neurocan: a brain chondroitin sulfate proteoglycan
.
Cell. Mol. Life Sci.
58
,
1842
1856
289
Spicer
,
A.P.
,
Joo
,
A.
and
Bowling
,
R.A.
, Jr.
(
2003
)
A hyaluronan binding link protein gene family whose members are physically linked adjacent to chrondroitin sulfate proteoglycan core protein genes: the missing links
.
J. Biol. Chem.
278
,
21083
21091
290
Kinugasa
,
Y.
,
Ishiguro
,
H.
,
Tokita
,
Y.
,
Oohira
,
A.
,
Ohmoto
,
H.
and
Higashiyama
,
S.
(
2004
)
Neuroglycan C, a novel member of the neuregulin family
.
Biochem. Biophys. Res. Commun.
321
,
1045
1049
291
Shuo
,
T.
,
Aono
,
S.
,
Matsui
,
F.
,
Tokita
,
Y.
,
Maeda
,
H.
,
Shimada
,
K.
et al. 
(
2004
)
Developmental changes in the biochemical and immunological characters of the carbohydrate moiety of neuroglycan C, a brain-specific chondroitin sulfate proteoglycan
.
Glycoconj. J.
20
,
267
278
292
Pap
,
T.
and
Bertrand
,
J.
(
2013
)
Syndecans in cartilage breakdown and synovial inflammation
.
Nat. Rev. Rheumatol.
9
,
43
55
293
Cheng
,
B.
,
Montmasson
,
M.
,
Terradot
,
L.
and
Rousselle
,
P.
(
2016
)
Syndecans as cell surface receptors in cancer biology. A focus on their interaction with PDZ domain proteins
.
Front. Pharmacol.
7
,
10
294
von Holst
,
A.
,
Sirko
,
S.
and
Faissner
,
A.
(
2006
)
The unique 473HD-chondroitinsulfate epitope is expressed by radial glia and involved in neural precursor cell proliferation
.
J. Neurosci.
26
,
4082
4094
295
Milev
,
P.
,
Friedlander
,
D.R.
,
Sakurai
,
T.
,
Karthikeyan
,
L.
,
Flad
,
M.
,
Margolis
,
R.K.
et al. 
(
1994
)
Interactions of the chondroitin sulfate proteoglycan phosphacan, the extracellular domain of a receptor-type protein tyrosine phosphatase, with neurons, glia, and neural cell adhesion molecules
.
J. Cell Biol.
127
,
1703
1715
296
Wassenhove-McCarthy
,
D.J.
and
McCarthy
,
K.J.
(
1999
)
Molecular characterization of a novel basement membrane-associated proteoglycan, leprecan
.
J. Biol. Chem.
274
,
25004
25017
297
Capellini
,
T.D.
,
Dunn
,
M.P.
,
Passamaneck
,
Y.J.
,
Selleri
,
L.
and
Di Gregorio
,
A.
(
2008
)
Conservation of notochord gene expression across chordates: insights from the Leprecan gene family
.
Genesis
46
,
683
696
298
Kaul
,
S.C.
,
Sugihara
,
T.
,
Yoshida
,
A.
,
Nomura
,
H.
and
Wadhwa
,
R.
(
2000
)
Gros1, a potential growth suppressor on chromosome 1: its identity to basement membrane-associated proteoglycan, leprecan
.
Oncogene
19
,
3576
3583
299
Sadler
,
J.E.
(
1997
)
Thrombomodulin structure and function
.
Thromb. Haemost.
78
,
392
395
PMID:
[PubMed]
300
Esmon
,
C.
(
2005
)
Do-all receptor takes on coagulation, inflammation
.
Nat. Med.
11
,
475
477
301
Chen
,
S.
and
Birk
,
D.E.
(
2013
)
The regulatory roles of small leucine-rich proteoglycans in extracellular matrix assembly
.
FEBS J.
280
,
2120
2137
302
Merline
,
R.
,
Schaefer
,
R.M.
and
Schaefer
,
L.
(
2009
)
The matricellular functions of small leucine-rich proteoglycans (SLRPs)
.
J. Cell Commun. Signal.
3
,
323
335
303
Neame
,
P.
and
Kay
,
C.J.
(
2000
) Small leucine rich proteoglycans. In
Proteoglycans: Structure, Biology and Molecular Interactions
(
Iozzo
,
R. V.
ed.), pp.
201
236
,
CRC Press
,
Marcell Dekker, NY, Basel
304
Ikegawa
,
S.
(
2008
)
Expression, regulation and function of asporin, a susceptibility gene in common bone and joint diseases
.
Curr. Med. Chem.
15
,
724
728
305
Johnson
,
H.J.
,
Rosenberg
,
L.
,
Choi
,
H.U.
,
Garza
,
S.
,
Hook
,
M.
and
Neame
,
P.J.
(
1997
)
Characterization of epiphycan, a small proteoglycan with a leucine-rich repeat core protein
.
J. Biol. Chem.
272
,
18709
18717
306
Bost
,
F.
,
Diarra-Mehrpour
,
M.
and
Martin
,
J.P.
(
1998
)
Inter-alpha-trypsin inhibitor proteoglycan family. A group of proteins binding and stabilizing the extracellular matrix
.
Eur. J. Biochem.
252
,
339
346
307
Fries
,
E.
and
Kaczmarczyk
,
A.
(
2003
)
Inter-alpha-inhibitor, hyaluronan and inflammation
.
Acta Biochim. Pol.
50
,
735
742
PMID:
[PubMed]
308
Liu
,
K.L.
,
Wu
,
J.
,
Zhou
,
Y.
and
Fan
,
J.H.
(
2015
)
Increased Sushi repeat-containing protein X-linked 2 is associated with progression of colorectal cancer
.
Med. Oncol.
32
,
99
309
Tanaka
,
K.
,
Arao
,
T.
,
Tamura
,
D.
,
Aomatsu
,
K.
,
Furuta
,
K.
,
Matsumoto
,
K.
et al. 
(
2012
)
SRPX2 is a novel chondroitin sulfate proteoglycan that is overexpressed in gastrointestinal cancer
.
PLoS ONE
7
,
e27922
310
Sassetti
,
C.
,
Van Zante
,
A.
and
Rosen
,
S.D.
(
2000
)
Identification of endoglycan, a member of the CD34/podocalyxin family of sialomucins
.
J. Biol. Chem.
275
,
9001
9010
311
Jackson
,
D.G.
,
Bell
,
J.I.
,
Dickinson
,
R.
,
Timans
,
J.
,
Shields
,
J.
and
Whittle
,
N.
(
1995
)
Proteoglycan forms of the lymphocyte homing receptor CD44 are alternatively spliced variants containing the v3 exon
.
J. Cell Biol.
128
,
673
685
312
Bartolomucci
,
A.
,
Pasinetti
,
G.M.
and
Salton
,
S.R.
(
2010
)
Granins as disease-biomarkers: translational potential for psychiatric and neurological disorders
.
Neuroscience
170
,
289
297
313
Burian
,
M.
and
Schittek
,
B.
(
2015
)
The secrets of dermcidin action
.
Int. J. Med. Microbiol.
305
,
283
286
314
Dockray
,
G.J.
(
2012
)
Cholecystokinin
.
Curr. Opin. Endocrinol. Diabetes Obes.
19
,
8
12
315
Huttner
,
W.B.
,
Gerdes
,
H.H.
and
Rosa
,
P.
(
1991
)
The granin-(chromogranin/secretogranin) family
.
Trends Biochem. Sci.
16
,
27
30
316
Noborn
,
F.
,
Gomez Toledo
,
A.
,
Sihlbom
,
C.
,
Lengqvist
,
J.
,
Fries
,
E.
,
Kjellen
,
L.
et al. 
(
2015
)
Identification of chondroitin sulfate linkage region glycopeptides reveals prohormones as a novel class of proteoglycans
.
Mol. Cell. Proteomics
14
,
41
49
317
Rehfeld
,
J.F.
(
2016
)
Cholecystokinin expression in tumors: biogenetic and diagnostic implications
.
Future Oncol.
12
,
2135
2147
318
Schittek
,
B.
(
2012
)
The multiple facets of dermcidin in cell survival and host defense
.
J. Innate Immun.
4
,
349
360
319
Schroder
,
J.M.
and
Harder
,
J.
(
2006
)
Antimicrobial skin peptides and proteins
.
Cell. Mol. Life Sci.
63
,
469
486
320
Shooshtarizadeh
,
P.
,
Zhang
,
D.
,
Chich
,
J.F.
,
Gasnier
,
C.
,
Schneider
,
F.
,
Haikel
,
Y.
et al. 
(
2010
)
The antimicrobial peptides derived from chromogranin/secretogranin family, new actors of innate immunity
.
Regul. Pept.
165
,
102
110
321
Taupenot
,
L.
,
Harper
,
K.L.
and
O'Connor
,
D.T.
(
2003
)
The chromogranin-secretogranin family
.
N. Engl. J. Med.
348
,
1134
1149