The synergistic function of miR-140–5p and miR-146a on TLR4-mediated cytokine secretion in osteoarthritic chondrocytes

Abstract

ΜiR-140–5p and miR-146a regulate inflammatory pathways including TLR4/NF-κB signaling and have been found to be involved in OA pathogenesis. In this study, we investigated the effect of the synergistic function of miR-140–5p and miR-146a on inflammation mediated by TLR4 in ΟΑ chondrocytes. Bioinformatics analysis revealed that TLR4 was the only common OA-related target gene of miR-140–5p and miR-146a, located in the sub-network with the highest MCODE score; it also showed that the target genes of miR-140-5p and miR-146a which located in MCODE sub-networks were enriched in OA-related biological processes and pathways. Overexpression of miR-140–5p or miR-146a and combined miR-140–5p/miR-146a overexpression in OA chondrocytes demonstrated that combined treatment had the strongest negative effect on TLR4 expression. Moreover, simultaneous overexpression of miR-140–5p and miR-146a resulted in the highest reduction of NF-κΒ phosphorylation levels, as well as IL-1b, IL-6 and TNFa expression levels in OA chondrocytes as compared to the reductions observed when either miR-140-5p or miR-146a was overexpressed. Our results, therefore, demonstrate for the first time, that the synergistic function of miR-140–5p and miR-146a have a strong protective effect against inflammatory mediators’ production in OA chondrocytes through targeting the TLR4/NF-κB signaling. © 2019 Elsevier Inc.