Meng Lijun, Zhu Yanli, Zhang Lanfang, Yang Lu, Dong Daiyuan, Yang Fang, Guo Xiaohe
Department of Gastroenterology, The First Affiliated Hospital of Henan Medical University, Xinxiang, China.
J Biochem Mol Toxicol. 2025 Aug;39(8):e70434. doi: 10.1002/jbt.70434.
Ulcerative colitis (UC) is a chronic inflammatory bowel disease that affects 5 million people globally. YTH N6-methyladenosine RNA binding protein C (YTHDC1) is a critical regulator in various biological processes, yet its role in UC remains undefined. This study aims to investigate the regulatory function of YTHDC1 in UC pathogenesis. An in vivo UC model was established in C57BL/6 mice using 3% dextran sulfate sodium (DSS). To establish an in vitro UC model, Caco-2 cells were exposed to 10 μg/mL lipopolysaccharide (LPS). Quantitative real-time PCR (qRT-PCR) was employed to detect mRNA expression levels of YTHDC1 and X-box binding protein 1 (XBP1). Protein expression was analyzed by Western blot analysis assay. Haematoxylin and eosin staining was used to assess colonic pathology. Enzyme-linked immunosorbent assay was performed to measure the levels of TNF-α, IL-6, and IL-1β. Immunohistochemistry assay was used to determine the LC3II-positive expression rate. m6A methylated RNA immunoprecipitation assay and RNA immunoprecipitation assay were used to analyze the association between YTHDC1 and XBP1. An actinomycin D assay was performed to evaluate the effect of YTHDC1 overexpression on XBP1 mRNA stability. The study showed YTHDC1 and XBP1 expression were downregulated in colonic tissues from UC patients. Overexpression of YTHDC1 increased colon length and body weight in DSS-induced mice and inhibited DSS-triggered production of TNF-α, IL-6, and IL-1β. Additionally, the upregulation of YTHDC1 counteracted the suppressive impact of DSS treatment on autophagy in colon tissues. In Caco-2 cells, LPS treatment promoted TNF-α, IL-6, and IL-1β production, whereas these effects were attenuated after YTHDC1 overexpression. Moreover, LPS-induced Caco-2 cells showed decreases in the ratio of LC3II to LC3I and beclin1 protein expression and an increase in P62 protein expression, however, YTHDC1 overexpression relieved these effects. In addition, the results showed that the treatment with AMPK inhibit or attenuated YTHDC1 overexpression-induced effects in LPS-treated Caco-2 cells. Furthermore, YTHDC1 was found to stabilize the expression of XBP1 and activate the AMPK/mTOR pathway. Thus, YTHDC1 overexpression inhibited inflammation and promoted autophagy to ameliorate UC through the XBP1/AMPK/mTOR pathway. These findings highlight YTHDC1 as apotential therapeutic target for UC treatment.
溃疡性结肠炎（UC）是一种慢性炎症性肠病，全球有500万人受其影响。YTH N6-甲基腺苷RNA结合蛋白C（YTHDC1）是各种生物学过程中的关键调节因子，但其在UC中的作用仍不明确。本研究旨在探讨YTHDC1在UC发病机制中的调节功能。使用3%葡聚糖硫酸钠（DSS）在C57BL/6小鼠中建立体内UC模型。为建立体外UC模型，将Caco-2细胞暴露于10μg/mL脂多糖（LPS）。采用定量实时PCR（qRT-PCR）检测YTHDC1和X盒结合蛋白1（XBP1）的mRNA表达水平。通过蛋白质印迹分析测定法分析蛋白质表达。苏木精和伊红染色用于评估结肠病理学。进行酶联免疫吸附测定以测量TNF-α、IL-6和IL-1β的水平。免疫组织化学测定法用于确定LC3II阳性表达率。m6A甲基化RNA免疫沉淀测定法和RNA免疫沉淀测定法用于分析YTHDC1与XBP1之间的关联。进行放线菌素D测定以评估YTHDC1过表达对XBP1 mRNA稳定性的影响。研究表明，UC患者结肠组织中YTHDC1和XBP1表达下调。YTHDC1过表达增加了DSS诱导小鼠的结肠长度和体重，并抑制了DSS触发的TNF-α、IL-6和IL-1β的产生。此外，YTHDC1的上调抵消了DSS治疗对结肠组织自噬的抑制作用。在Caco-2细胞中，LPS处理促进了TNF-α、IL-6和IL-1β的产生，而YTHDC1过表达后这些作用减弱。此外，LPS诱导的Caco-2细胞中LC3II与LC3I的比率以及beclin1蛋白表达降低，P62蛋白表达增加，然而，YTHDC1过表达减轻了这些作用。此外，结果表明，用AMPK抑制剂处理减弱了YTHDC1过表达在LPS处理的Caco-2细胞中诱导的作用。此外，发现YTHDC稳定XBP1的表达并激活AMPK/mTOR途径。因此，YTHDC1过表达通过XBP1/AMPK/mTOR途径抑制炎症并促进自噬以改善UC。这些发现突出了YTHDC1作为UC治疗的潜在治疗靶点。
