To investigate whether microRNA-485-5p (miR-485-5p) can participate in osteoarthritis by inhibiting chondrogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) and promoting the secretion of inflammatory factors.
BMSCs were obtained from mouse bone marrow samples and identified by flow cytometry. The expression of specific genes and miR-485-5p in the differentiation of BMSCs was detected by quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). The influence of miR-485-5p on chondrogenic differentiation was subsequently evaluated by toluidine blue staining, detection of chondrogenic specific gene expression and inflammatory factors. After over-expressing SOX9, it was assessed whether miR-485-5p can affect the chondrogenic differentiation of BMSCs by inhibiting SOX9, so as to promote the secretion of inflammatory factors.
The miR-485-5p level was negatively correlated with the degree of differentiation of BMSCs. After overexpression of microRNA-485-5p in BMSCs, the expression of cartilage surface marker genes and toluidine blue staining were reduced, while the expression of cartilage surface inflammation factors, including interleukin and tumor necrosis factor, was significantly enhanced. Meanwhile, opposite results were observed when miR-485-5p was inhibited. In addition, overexpression of SOX9 could restore the secretion of inflammatory cytokines induced by microRNA-485-5p.
MiR-485-5p can decrease the level of SOX9, promote the production of inflammatory factors on the cartilage surface, and block the differentiation of mouse BMSCs into chondrocytes.