LncRNA ADAMTS9-AS2 Modulates Human Mesenchymal Stem Cells Chondrogenesis And Underlying Mechanism

Objective:Various types of articular cartilage injury diseases have triggered a huge demand for articular cartilage repair,and how to induce stem cells to conduct cartilage differentiation more effectively and precisely is a great challenge in the field of cartilage repair nowadays.Human mesenchymal stem cells(hMSCs)are excellent cell sources for current tissue engineering-based regenerative strategies.However,when untreated hMSCs implanted in a cartilage defect,they fail to chondrogenesis and lead to ossification.Long non-coding RNAs(lncRNAs)have been identified to be tightly linked with cell fate determination and stem cell differentiation in recent years.Recent studies have shown that IncRNAs play great roles in the chondrocyte differentiation of stem cells.In this study we aimed to screen and investigate the contribution of the lncRNA-ADAMTS9-AS2 to hMSCs chondrogenesis,and reveal its biological function.Methods and Materials:Primary hMSCs were treated with chondrocyte induced medium before analyzing IncRNA expression profiles via micro-array.Then,lncRNA-ADAMTS9-AS2 was suppressed and overexpressed by infecting with lentivirus in hMSCs,and expression level of chondrocyte marker genes(SOX9,COL2?1,ACAN)were detected by Q-PCR and IHC.LncRNA-ADAMTS9-AS2 interaction with miR-942-5p and miR-942-5p combination with its target gene Scrgl were confirmed by luciferase report assay.Furthermore,miR-942-5p was suppressed and overexpressed regulated by mimic and inhibitor in vitro to examine hMSCs chondrocyte differentiation.In vivo study,femoral head were taken from rat and then we used electric drill to develop a cartilage defect.We injected the transformed hMSCs by lentivirus into the cartilage defect,and implanted the femoral head into the back subcutaneous position of nude mice.Results:LncRNA-ADAMTS9-AS2 increased rapidly during primary hMSCs chondrocyte differentiation.Suppression of LncRNA-ADAMTS9-AS2 impaired HMSCs chondrogenesis,while overexpression of LncRNA-ADAMTS9-AS2 promoted hMSCs chondrocyte differentiation.LncRNA-ADAMTS9-AS2 interacted with miR-942-5p and miR-942-5p could interact with Scrg1.MiR-942-5p also could regulate hMSCs chondrocyte differentiation.LncRNA-ADAMTS9-AS2 could also promote hMSCs chondrocyte differentiation on cartilage defect in vivo.Conclusion:LncRNA-ADAMTS9-AS2 can promote chondrocyte differentiation both in vitro and in vivo.It can interact with miR-942-5p and inhibits miR-942-5p negative function by targeting Scrgl.LncRNA-ADAMTS9-AS2 may contribute to the cartilage defect and provide a potentially therapeutic target.