Xinfeng Capsule alleviates interleukin-1β-induced chondrocyte inflammation and extracellular matrix degradation by regulating the miR-502-5p/TRAF2/NF-κB axis
Objective To investigate the mechanism that mediates the inhibitory effect of Xinfeng Capsule(XFC)on interleukin(IL)-1β-induced impairment of chondrocytes.Methods XFC-medicated serum was collected from SD rats with XFC gavage,and its optimal concentration for chondrocyte treatment was determined using Cell Counting Kit-8 assay and flow cytometry.Dual luciferase reporter analysis was performed to analyze the targeting relationship between miR-502-5p and TRAF2.In cultured human chondrocytes induced with IL-1β,the effects of transfection with miR-502-5p inhibitor and XFC-medicated serum,alone or in combination,on expression levels of IL-1β,tumor necrosis factor-α(TNF-α),IL-4,and IL-10 were examined with ELISA,and the changes in the expressions of collagen type Ⅱ alpha 1(COL2A1),matrix metalloproteinase 13(MMP13),adisintegrin and metalloproteinase with thrombospondin motifs 5(ADAMTS5),and miR-502-5p/TRAF2/NF-κB axis gene expression were detected using RT-qPCR,Western blotting,and immunofluorescence assay.Results In cultured human chondrocytes,treatment with IL-1β significantly decreased the cell viability,increased cell apoptosis rate,lowered miR-502-5p,IL-4,IL-10,and COL2A1 expressions,and enhanced IL-1β,TNF-α,ADAMTS5,MMP13,TRAF2,and NF-κB p65 expressions(P<0.05),and these changes were significantly improved by treatment with XFC-medicated serum at the optimal concentration of 20%(P<0.05).Transfection of the chondrocytes with miR-502-5p inhibitor resulted in elevated expressions of IL-1β,TNF-α,ADAMTS5,MMP13,TRAF2,and NF-κB p65 and lowered expressions of miR-502-5p,IL-4,IL-10,and COL2A1,and XFC-medicated serum obviously reversed the effects of miR-502-5p inhibitor.Conclusion XFC can inhibit IL-1β-induced inflammatory response and ECM degradation in cultured human chondrocytes possibly by regulating the miR-502-5p/TRAF2/NF-κB axis.