Overexpression of miR-146a-5p alleviate SDF1-induced cartilage degradation through repression TRAF6 mediated p38-MAPK signal pathway
Abstract Background : Previous study have revealed that miR-146a-5p has a role in osteoarthritis (OA) development, here, we aim to further explore the underlying mechanism of miR-146a-5P in OA both in vitro and in vitro . Methods : RT-PCR was used to detect the level of miR-146a-5p in OA patients. Primary chondrocytes were treated with SDF-1 to induce an OA model in vitro , and an IL-1β mediated OA model in rats were also used. Gain- or loss- of function assays of miR-146a-5p and TRAF6 were conducted to determine their roles in regulating the proliferation, apoptosis and cartilage degradation of chondrocytes. Results : MiR-146a-5p was overexpressed in OA patients while downregulated in SDF-1 treated chondrocytes. Functionally, miR-146a-5p considerably accelerated the proliferation, inhibited apoptosis and limited ECM degradation of SDF-1 induced chondrocytes. However, TRAF6 upregulation had the opposite effects. Moreover, miR-146a-5p also inhibited OA progression in vivo. Mechanistically, miR-146a-5p targeted at the 3’UTR of TRAF6 and relieved TRAF6 mediated p38-MAPK/NF-κB activation. Conclusions : MiR-146a-5p exerted protective effects chondrocytes against SDF-1 or IL-1β induced OA by regulating the proliferation, apoptosis and ECM degradation of chondrocytes by regulating the TRAF6/ p38-MAPK signaling pathway.