Mechanism of miR-15a regulating the growth and apoptosis of human knee joint chondrocytes by targeting SMAD2

Abstract

Objective To investigate the effects of miR-15a on proliferation and apoptosis of human knee articular chondrocytes and explore its underlying mechanism. Methods qRT-PCR was used to detect the expression of miR-15a in normal chondrocytes and knee arthritic chondrocytes; miR-con (transfected miR-con), miR-15a (transfected miR-15a mimics), anti-miR-con group (transfected anti-miR-con), anti-miR-15a group (transfected anti-miR-15a mimics), pcDNA group (transfected pcDNA), pcDNA-SMAD2 group (transfected pcDNA-SMAD2), the miR-15a + pcDNA group (co-transfected miR-15a and pcDNA), miR-15a + pcDNA-SMAD2 group (co-transfected miR-15a mimics and pcDNA-SMAD2), were transfected into knee articular chondrocytes by liposome method, respectively. The cell proliferation and apoptosis of each group were detected by MTT assay and flow cytometry. The protein expression of SMAD2 was detected by Western blot. The fluorescence activity of each group was detected by dual luciferase reporter gene assay. Results The expression of miR-15a in knee arthritis chondrocytes was significantly increased (p < .05) compared with that in normal chondrocytes. Moreover, overexpression of miR-15a and silencing of SMAD2 inhibited proliferation and promoted apoptosis in knee arthritis chondrocyte. MiR-15a targeted SMAD2. Overexpression of SMAD2 reversed the inhibitory effects on proliferation and promotion effects on apoptosis induced by miR-15a in knee arthritis chondrocytes. Conclusion miR-15a can inhibit the proliferation and promote apoptosis of knee arthritis chondrocytes. The mechanism may be related to SMAD2, which will provide a new target for the treatment of knee arthritis.