Down-Regulation Of Microrna-145 Expression Promote Resistance To Chondrocyte Apoptosis In Osteoarthritis

Objective: This study was undertaken to probe deeply into effects of microRNA-145 (miR-145) expression on chondrocyte apoptosis in osteoarthritis (OA). Methods: A group of 71 OA patients (32 males and 39 females) with age ranging from 49 to 77 years were recruited into this study. Chondrocytes isolated from their OA tissues were separated into four groups: group A (blank control, no transfection), group B (transfection with empty vector pGenesil-1), group C (miR-145 plasmid) and group D (miR-145 inhibitor). Transfection efficiency was observed under fluorescence microscope. Real-time quantitative PCR (RT-qPCR) and western blotting were used to detect expressions of miR-145 and N-cadherin (mRNA) in the chondrocytes of each group. And flow cytometry was utilized to determine cycle and apoptosis of cells in each group. Results: miR-145 expression showed relationship with gender and OA grading (both P < 0.05). miR-145 expression increased in the group C and significantly decreased in the group D compared with that in the group A and group B (all P < 0.05). Interestingly, N-cadherin expression in the group D was increased compared with that in the three groups (all P < 0.05). Moreover, compared with the group A and group B, cell apoptosis was significantly abated and the cell proportion was decreased at the S stage in the group D, but promoted in the group C (all P < 0.05). Also, the group D had lower cell proportion and cell apoptosis rate than the group C (P < 0.05). Conclusion: Inhibition of miR-145 can suppress chondrocyte apoptosis in OA, indicating a new direction for OA treatment.