Type I interferon (IFN) is a critical pathogenic factor during the progression of lupus nephritis (LN). Although microRNAs (miRNAs) have been shown to control the IFN response in immune cells in LN, the role of miRNAs in resident renal cells remains unclear. We undertook this study to investigate the role of microRNA-130b (miR-130b) in the IFN pathway in renal cells as well as its therapeutic effect in LN.
Kidney tissues from patients and (NZB × NZW)F1 lupus-prone mice were collected for detecting miR-130b levels. Primary renal mesangial cells (RMCs) were used to determine the role of miR-130b in the IFN pathway. We overexpressed miR-130b by administering miR-130b agomir in a mouse model of IFNα-accelerated LN to test its therapeutic efficacy.
Down-regulated miR-130b expression was observed in kidney tissues from patients and lupus-prone mice. Further analysis showed that underexpression of miR-130b correlated negatively with abnormal activation of the IFN response in LN patients. In vitro, overexpressing miR-130b suppressed signaling downstream from the type I IFN pathway in RMCs by targeting IFN regulatory factor 1 (IRF-1). The opposite effect was observed when endogenous miR-130b expression was inhibited. The inverse correlation between IRF1 and miR-130b levels was detected in renal biopsy samples from LN patients. More importantly, in vivo administration of miR-130b agomir reduced IFNα-accelerated progression of LN, with decreased proteinuria, lower levels of immune complex deposition, and lack of glomerular lesions.
MicroRNA-130b is a novel negative regulator of the type I IFN pathway in renal cells. Overexpression of miR-130b in vivo ameliorates IFNα-accelerated LN, providing potential novel strategies for therapeutic intervention in LN.