CD226 deficiency on regulatory T cells aggravates renal fibrosis via up-regulation of Th2 cytokines through miR-340.

In this study, we observed that deletion of CD226 on regulatory T cells (Tregs) precedes renal fibrosis in a mouse unilateral ureteral obstruction (UUO) model. First, we generated Treg-specific CD226 gene knockout mice (CD226fl/fl Foxp3YFP-Cre ). Next, CD226fl/fl Foxp3YFP-Cre mice and Foxp3YFP-Cre control mice were subjected to UUO surgery. Pathologic analysis and Sirius red and Masson's trichrome staining showed that the kidneys of CD226fl/fl Foxp3YFP-Cre mice following UUO showed much more severe interstitial fibrosis than Foxp3YFP-Cre control mice at days 10 and 20. Additionally, CD226fl/fl Foxp3YFP-Cre mice showed increased fibronectin expression, as demonstrated by immunohistochemistry (IHC) staining. Although Treg cell-restricted CD226 deficiency showed increased Foxp3+ expression, expression of the cell surface functional molecule CD103 was significantly reduced, indicating impaired homeostasis in the Tregs of CD226fl/fl Foxp3YFP-Cre mice. To better understand CD226 function, RNA sequencing (RNA-Seq) analysis was conducted in Tregs isolated from CD226fl/fl Foxp3YFP-Cre and Foxp3YFP-Cre mice. RNA-Seq data showed that the helper T cell (Th) 2-related cytokines IL-4 and IL-10 were significantly up-regulated in CD226 deficient Tregs. In addition, mRNA analysis of kidney samples from the mice following UUO by qPCR also showed increased IL-4 and IL-10 expression in CD226fl/fl Foxp3YFP-Cre mice, as well as elevated TGF-β1 levels, indicating that CD226 deficiency in Tregs res...

Source: Journal of Leukocyte Biology - December 3, 2019 Category: Hematology Authors: Mu Y, Zhang J, Liu Y, Ma J, Jiang D, Zhang X, Yi X, Cheng K, Shen S, Yang Y, Zhuang R, Zhang Y Tags: J Leukoc Biol Source Type: research