Adipose-Derived Mesenchymal Stem Cells Ameliorate Ulcerative Colitis Through miR-1236 Negatively Regulating the Expression of Retinoid-Related Orphan Receptor Gamma.

Mesenchymal stem cells (MSCs) were reported to accelerate the curing of ulcerative colitis (UC). Altered expression of microRNAs (miRNAs) has recently revealed association with UC. However, the effect of adipose-derived MSCs (ASCs) on UC and the mechanism of how miRNAs regulate UC remain unclear. We investigated the effect of ASCs on 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced UC in rat colon tissues. qRT-PCR and immunofluorescence analyses were performed to monitor the expression of miR-1236 and its target molecule, retinoid-related orphan receptor γ (RORγ). Regulation of the expression of RORγ by miR-1236 was assessed using luciferase reporter construct assays and miR-1236 mimic transfection. The relationship between miR-1236 and RORγ was further investigated in HT29 cells induced by TNF-α. ASCs highly ameliorated UC and decreased the inflammation markers in rats with TNBS-induced UC. In addition, ASCs upregulated the expression of miR-1236 and decreased the expression of RORγ in the TNBS-induced rat model of UC. The luciferase reporter assay and bioinformatic analysis demonstrated that the expression of RORγ was directly targeted and regulated by miR-1236. Specifically, the expression of RORγ was suppressed by miR-1236 mimic and enhanced by miR-1236 inhibitor. Furthermore, we demonstrated that exogenous miR-1236 mimic could inhibit the expression of RORγ in HT29 cell induced by TNF-α. ASCs effectively alleviated UC in rats with the expression of miR-1236 alteration, and miR-1236 may play important roles in UC by downregulating the expression of RORγ.