SMARCA5,SWI/SNF家族中的一种蛋白质,先前已通过甲基化与溃疡性结肠炎(UC)的发展有关。然而,SMARCA5促进结肠炎症和Th17和Treg细胞失衡的具体分子机制尚不清楚.本研究旨在探索这些分子机制。采用葡聚糖硫酸钠诱导建立UC小鼠模型,然后测量老鼠的体重,疾病活动指数(DAI)评分,结肠长度,结肠的病理变化,和FITC-葡聚糖浓度。IL-17a的水平,IFN-γ,IL-6,TNF-α,TGF-β,和IL-10被测量,随着ZO-1和Occludin蛋白的表达。流式细胞术用于评估UC小鼠脾脏和肠系膜淋巴结中IL-17+CD4+(Th17+)细胞和FOXP3+CD25+CD4+(Treg+)细胞的存在。我们观察到SMARCA5和RNF180增加,而ALKBH5在UC小鼠结肠组织中下调。SMARCA5或RNF180敲低或ALKBH5过表达改善UC小鼠结肠炎症和Th17/Treg细胞失衡,体重增加,结肠长度,FOXP3+CD25+CD4+T细胞,ZO-1,Occludin的水平,TGF-β,IL-10和FOXP3。它降低了DAI分数,IL-17+CD4+T细胞,和IL-17a的水平,IFN-γ,IL-6,TNF-α,和ROR-γt。ALKBH5通过m6A修饰抑制SMARCA5表达,而RNF180通过泛素化降低ALKBH5表达。我们的发现表明,RNF180通过调节ALKBH5/SMARCA5轴加重UC小鼠的结肠炎症和Th17/Treg细胞失衡。
SMARCA5, a protein in the SWI/SNF family, has been previously implicated in the development of ulcerative colitis (UC) through methylation. However, the specific molecular mechanisms by which SMARCA5 contributes to colonic inflammation and the imbalance between Th17 and Treg cells remain unclear. This study was designed to explore these molecular mechanisms. A UC mouse model was established using dextran sulfate sodium induction, followed by measurements of mouse weight, disease activity index (DAI) score, colon length, pathological changes in the colon, and FITC-dextran concentration. The levels of IL-17a, IFN-γ, IL-6, TNF-α, TGF-β, and IL-10 were measured, along with the protein expression of ZO-1 and Occludin. Flow cytometry was used to assess the presence of IL-17 + CD4 + (Th17 +) cells and FOXP3 + CD25 + CD4 + (Treg +) cells in the spleen and mesenteric lymph nodes of UC mice. We observed that SMARCA5 and RNF180 were increased, while
ALKBH5 was downregulated in UC mouse colon tissue. SMARCA5 or RNF180 knockdown or
ALKBH5 overexpression ameliorated the colon inflammation and Th17/Treg cell imbalance in UC mice, shown by increased body weight, colon length, FOXP3 + CD25 + CD4 + T cells, and the levels of ZO-1, Occludin, TGF-β, IL-10, and FOXP3. It decreased DAI scores, IL-17 + CD4 + T cells, and levels of IL-17a, IFN-γ, IL-6, TNF-α, and ROR-γt.
ALKBH5 inhibited SMARCA5 expression via m6A modification, while RNF180 reduced
ALKBH5 expression via ubiquitination. Our findings indicate that RNF180 aggravated the colon inflammation and Th17/Treg cell imbalance in UC mice by regulating the
ALKBH5/SMARCA5 axis.