Inflammatory response mediated by immune cells is either directly or indirectly regulated by mesenchymal stromal cells (MSCs). Accumulating evidence suggests that thrombospondin-1 (TSP-1) is highly expressed in response to inflammation. In this work, we isolated and identified human thymic mesenchymal stromal cells (tMSCs) and detected the expression of TSP-1. We found that tMSCs expressed TSP-1 and Poly (I:C) or LPS treatment promoted the expression of TSP-1. Further, we isolated and identified exosomes originating from tMSCs (MEXs). Notably, exosomes derived from LPS-pretreated tMSCs (MEXs LPS ) promoted the polarization of macrophages to M1-like phenotype and IL-6, TNF-α secretion as well as the pro-inflammatory differentiation of CD4 + T cells into Th17 cells. Upon silencing the expression of TSP-1 in tMSCs, the pro-inflammatory effects of MEXs LPS were suppressed. Therefore, these findings uncovered TSP-1 as the principal factor in MEXs LPS pro-inflammatory regulation.

Objective: Increasing the efficiency of early diagnosis using noninvasive biomarkers is crucial for enhancing the survival rate of lung cancer patients. We explore the differential expression of non-small cell lung cancer (NSCLC)-related long noncoding RNAs (lncRNAs) in urinary exosomes in NSCLC patients and normal controls to diagnose lung cancer. Methods: A differential expression analysis between NSCLC patients and healthy controls was performed using microarrays. Gene ontology (GO) term and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were used to predict potential functions of lncRNAs in NSCLC. quantitative real-time PCR (QT-PCR) was used to verify microarray results. Results: A total of 640 lncRNAs (70 up- and 570 down-regulated) were differentially expressed in NSCLC patients in comparison to healthy controls. Six lncRNAs were detected by QT-PCR. GO term and KEGG pathway analyses showed that differential lncRNAs were enriched in cellular component organization or biogenesis, as well as other biological processes and signaling pathways, such as the PI3K-AKT, FOXO, p53, and fatty acid biosynthesis. Conclusions: The differential lncRNAs in urinary exosomes are potential diagnostic biomarkers of NSCLC. The lncRNAs enriched in specific pathways may be associated with tumor cell proliferation, tumor cell apoptosis, and the cell cycle involved in the pathogenesis of NSCLC.

Hepatocellular carcinoma (HCC) is a frequently seen malignant tumor globally. The occurrence of cisplatin (DDP) resistance is one of the main reasons for the high mortality of HCC patients. Therefore, it is of great theoretical significance and application value to explore the mechanism of chemotherapy resistance. Drug resistance can be modulated by exosomes containing mRNAs, micro RNAs (miRNAs) and other non-coding RNA (ncRNAs). Exosomal miR-199a-3p (Exo-miR-199a-3p) was subjected to extraction and verification. Whether exo-miR-199a-3p could make HCC cells sensitive to DDP in vitro was verified via flow cytometry, Cell Counting Kit-8 (CCK-8) assay, immunofluorescence assay and Transwell assay. Intravenous injection of exo-miR-199a-3p and intraperitoneal injection of DDP were carried out in vivo . Moreover, the possible targets of miR-199a-3p were screened through bioinformatics analysis, which were ascertained by Western blotting (WB). Then, miR-199a-3p levels in human normal liver epithelial cell line HL-7702 and HCC cell lines HuH7 and HuH7/DDP were elevated in a concentration-dependent manner. Exo-miR-199a-3p has abilities to adjust underlying targets and conjugate cells, to repress cells to invade, stimulate their apoptosis and abate their ability. Additionally, the caudal injection of exo-miR-199a-3p reversed the chemoresistance of tumors and slowed down their growth in the body owing to the up-regulation of miR-199a-3p and down-regulation of underlying target proteins in tumors. Finally, exo-miR-199a-3p was found to overturn the HCC’s resistance to DDP, and it may function in DDP-refractory HCC therapy as an underlying option in the future.

PLSCRs (phospholipid scramblases) are palmitoylated membrane-associating proteins. Regardless of the given names, their physiological functions are not clear and thought to be unrelated to phospholipid scrambling activities observed in vitro . Using a previously established cell line of HEK-293 (human embryonic kidney-293) cells constitutively expressing human Scr3 (PLSCR3) that interacts with ALG-2 (apoptosis-linked gene 2) Ca 2+ -dependently, we found that Scr3 was secreted into the culture medium. Secretion of Scr3 was suppressed by 2-BP (2-bromopalmitate, a palmitoylation inhibitor) and by GW4869 (an inhibitor of ceramide synthesis). Secreted Scr3 was recovered in exosomal fractions by sucrose density gradient centrifugation. Palmitoylation sites and the N-terminal Pro-rich region were necessary for efficient secretion, but ABSs (ALG-2-binding sites) were dispensable. Overexpression of GFP (green fluorescent protein)-fused VPS4B E235Q , a dominant negative mutant of an AAA (ATPase associated with various cellular activities) ATPase with a defect in disassembling ESCRT (endosomal sorting complex required for transport)-III subunits, significantly reduced secretion of Scr3. Immunofluorescence microscopic analyses showed that Scr3 was largely localized to enlarged endosomes induced by overexpression of a GFP-fused constitutive active mutant of Rab5A (GFP–Rab5A Q79L ). Secreted Scr3 was taken up by HeLa cells, suggesting that Scr3 functions as a cell-to-cell transferable modulator carried by exosomes in a paracrine manner.