RESUMO
BACKGROUND:Circular RNAs(circRNAs)play important roles in a variety of diseases or tumors,and recent findings have revealed that circRNAs are abnormally expressed in knee osteoarthritis and are involved in disease progression through microRNA/mRNA regulation. OBJECTIVE:To investigate the effect of circRNA WD repeat containing protein 1(circ-BRWD1)/miR-488-3p/DNA methyltransferase 3A(DNMT3A)on the proliferation and apoptosis of chondrocytes in knee osteoarthritis. METHODS:Real-time fluorescence quantitative PCR was performed to detect the expression of circ-BRWD1,miR-488-3p,DNMT3A in knee osteoarthritis chondrocytes.Cells were divided into si-NC group,si-circ-BRWD1 group,vector group,circ-BRWD1 group,si-circ-BRWD1+anti-miR-NC group,si-circ-BRWD1+anti-miR-488-3p group,miR-NC group,miR-488-3p group,anti-miR-NC group,anti-miR-488-3p group,miR-488-3p+vector group,miR 488-3p+DNMT3A group.Real-time fluorescence quantitative PCR was used to detect circ-BRWD1,miR-488-3p,DNMT3A expression,MTT and flow cytometry assay were used to detect cell proliferation and apoptosis.Western blot assay was used to detect DNMT3A and proliferation/apoptosis-related protein expression.Dual luciferase reporter assay was used to Dual luciferase reporter assay to detect the targeting relationship of circ-BRWD1 with miR-488-3p and miR-488-3p with DNMT3A. RESULTS AND CONCLUSION:circ-BRWD1 and DNMT3A were highly expressed and miR-488-3p was lowly expressed in knee osteoarthritis chondrocytes compared with normal chondrocytes.Knockdown of circ-BRWD1 or overexpression of miR-488-3p inhibited proliferation and induced apoptosis in knee osteoarthritis chondrocytes.circ-BRWD1 targeted negative regulation of miR-488-3p and inhibition of miR-488-3p reversed the effect of circ-BRWD1 knockdown on chondrocyte proliferation and apoptosis in knee osteoarthritis.miR-488-3p targeted negative regulation of DNMT3A and upregulation of DNMT3A reversed the effect of miR-488-3p overexpression on chondrocyte proliferation and apoptosis in knee osteoarthritis.circ-BRWD1 could regulate the expression of DNMT3A by regulating miR-488-3p.To conclude,knockdown of circ-BRWD1 inhibits chondrocyte proliferation and induces apoptosis in knee osteoarthritis,and the mechanism of action may be related to the regulation of miR-488-3p/DNMT3A axis.