Depletion of microRNA-183-96-182 miRNA cluster in lymphocytes suppresses anti-dsDNA autoantibody production and IgG deposition in kidney in C57BL/6-Faslpr/lpr mice

Abstract The miR-183-96-182 (miR-183C) is a highly conserved miRNA cluster among species. Our previous work found a significant upregulation of miR-183C in the splenic cells of three different murine models of systemic lupus erythematosus (SLE). Current studies revealed that miR-183C miRNAs are critically involved in immunity and autoimmunity. In this study, we found that inhibition of miR-182 alone or miR-183C in vitro with antagomirs significantly reduced lupus-related inflammatory cytokine IFN-γ and IL-6 in activated splenocytes from MRL or MRL/lpr mice. To further characterize the pathogenic role of miR-182 and miR-183C in lupus in vivo, we developed B6-lpr mice with conditional depletion of miR-182 or miR-183C in CD2+ lymphocyte. We found that depletion of either miR-182 or miR-183C in the lymphocytes of B6/lpr mice had no obvious effect on T and B cell development as similar percentage of CD4+. CD8+, CD19+, as well as Tregs, follicular helper T (TFH), germinal center B (GCB), and plasma cells were observed in the miR-182−/− and miR-183C−/− and their respective control. Importantly, we observed a significant reduction of serum anti-dsDNA autoantibodies in miR-183C−/− mice when compared to age-matched controls and the B6/lpr mice with miR-182 or miR-183C deficiency have significantly reduced IgG deposition in the kidneys. Meanwhile, there was reduced IFN production in ex vivo activated splenocytes from the knockout mice. Furthermore, we demonstrated that miR-182 and miR-183C regulated the inflammatory response in splenocytes via targeting forkhead box O1 (Foxo1). Together, our data suggest a potential therapeutic effect of targeting miR-183C in lupus.