Expression and Function of miR-140 in Different Stage Chondrocytes of Patients with Osteoarthritis

Abstract：Objective To investigate the expression miR-140 in different stage of osteoarthritis and its function after transfecting ds-miR-140 mimic/inhibitor into chondrocytes.Methods Cartilage was classified into three groups,normal group,mid-staged group and advanced staged group,according to the Kellgren and Lawrence criterion.6 8 cases of normal or OA cartilage were collected and chondrocytes were isolated.The second generation of chondrocytes were used to test.The levels of miR-140,COL2A1 and COL10A1 mRNA were measured with real-time fluorescent quantitative PCR.The ds-miR-140 mimic/inhibitorwere transfected into the mid-staged group,and the expression of COL2A1,COL10A1 and SOX9 were measured.Results Compared with the normal group,miR-140 expression in the mid-and advanced-staged group was decreased by 34.1％ and 49.3％ respectively,and its expression in advanced-staged group was decreased by 73.9％.Beside,SOX9 expression in the mid-and advanced-staged group was decreased by 75 ％ and 82.7 ％ respectively,COL2A1 expression decreased by 36.7 ％ and 78.7 ％ respectively,while COL10A1 expression increased to 1.66 times and 2.10 times respectively.After transfecting ds-miR-140 mimic/inhibitor into the mid-staged group,SOX9 expression was increased by 1.95 times or decreased by 59.1％,COL2 A1 expression was increased by 1.87 times or decreased by 68.8％,and COL10A1 expression was decreased by 73.0％ or increased by 1.96 times.Conclusion The expression level of miR-140 decreased in osteoarthritic chondroeytes,and was negatively related to the severity of OA.Overexpression its level by transfecting ds-miR-140 mimic into chondrocytes could up-regulate SOX9 and COL2 A1 expression while down-regulate COL10A1 expression.