Department of Gastroenterology, Hangzhou Hospital of Traditional Chinese Medicine, Hangzhou, Zhejiang 310000, P.R. China.
Department of Gastroenterology, Suzhou Municipal Hospital, Suzhou Hospital Affiliated to Nanjing Medical University, Suzhou, Jiangsu 215001, P.R. China.
Mol Med Rep. 2022 Aug;26(2). doi: 10.3892/mmr.2022.12765. Epub 2022 Jun 8.
Ulcerative colitis (UC) is a common chronic recurrent inflammatory disease, which seriously threatens human life and health. Therefore, the present study aimed to explore the role of tripartite motif‑containing (TRIM)22 in UC and its potential mechanism. C57BL/6 mice and HT‑29 cell models of UC were constructed using 2% dextran sulphate sodium (DSS). The protein and mRNA expression levels were detected by western blotting and reverse transcription‑quantitative PCR, respectively. Cell transfection was performed to overexpress Kruppel‑like factor 2 (KLF2), or knockdown KLF2, TRIM22 and TRIM30 expression. The levels of inflammatory factors were evaluated by enzyme‑linked immunosorbent assays. Cell Counting Kit‑8 and TUNEL staining assay were employed to assess cell viability and apoptosis. Dual‑luciferase reporter assay and chromatin immunoprecipitation assay were performed to determine the binding ability of the TRIM22 promoter to KLF2. The results revealed that DSS increased the expression levels of TRIM22 in HT‑29 cells and TRIM30 in mice. Short hairpin RNA (sh)‑TRIM30 could inhibit the NF‑κB pathway, and reduce the levels of TNF‑α, IL‑6 and IFN‑γ. Furthermore, KLF2 expression was downregulated in the cell model of UC, and the luciferase assay confirmed that the 3' untranslated region of TRIM22 was a direct target of KLF2. The ChIP assay also verified the binding of KLF2 with the TRIM22 promoter. Notably, knockdown of KLF2 reversed the enhancing effects of sh‑TRIM22 on the viability of DSS‑treated HT‑29 cells. In addition, compared with in the DSS + sh‑TRIM22 group, the protein expression levels of phosphorylated (p)‑NF‑κB and p‑IκBα were increased in the DSS + sh‑TRIM22 + sh‑KLF2 group, as were the levels of TNF‑α, IL‑6 and IFN‑γ. In conclusion, TRIM22 was upregulated in DSS‑induced HT‑29 cells. TRIM22 knockdown increased DSS‑induced HT‑29 cell viability and decreased apoptosis and inflammation; this was reversed by knockdown of KLF2. These findings suggested that TRIM22 may promote disease development through the NF‑κB signaling pathway in UC and could be inhibited by KLF2 transcription.
溃疡性结肠炎（UC）是一种常见的慢性复发性炎症性疾病，严重威胁着人类的生命和健康。因此，本研究旨在探讨三结构域含（TRIM）22 在 UC 中的作用及其潜在机制。采用 2%葡聚糖硫酸钠（DSS）构建 C57BL/6 小鼠和 HT-29 细胞 UC 模型。通过蛋白质印迹和逆转录定量 PCR 分别检测蛋白和 mRNA 表达水平。通过转染过表达 Kruppel 样因子 2（KLF2），或敲低 KLF2、TRIM22 和 TRIM30 的表达来进行细胞转染。通过酶联免疫吸附测定法评估炎症因子水平。采用细胞计数试剂盒-8 和 TUNEL 染色法评估细胞活力和细胞凋亡。双荧光素酶报告基因检测和染色质免疫沉淀分析用于确定 TRIM22 启动子与 KLF2 的结合能力。结果显示，DSS 增加了 HT-29 细胞中 TRIM22 和小鼠中 TRIM30 的表达水平。短发夹 RNA（sh）-TRIM30 可抑制 NF-κB 通路，降低 TNF-α、IL-6 和 IFN-γ 的水平。此外，UC 细胞模型中 KLF2 表达下调，荧光素酶测定证实 TRIM22 的 3'非翻译区是 KLF2 的直接靶标。ChIP 分析也验证了 KLF2 与 TRIM22 启动子的结合。值得注意的是，敲低 KLF2 逆转了 sh-TRIM22 对 DSS 处理的 HT-29 细胞活力的增强作用。此外，与 DSS+sh-TRIM22 组相比，DSS+sh-TRIM22+sh-KLF2 组中磷酸化（p）-NF-κB 和 p-IκBα 的蛋白表达水平以及 TNF-α、IL-6 和 IFN-γ 的水平均升高。结论：DSS 诱导的 HT-29 细胞中 TRIM22 上调。TRIM22 敲低增加了 DSS 诱导的 HT-29 细胞活力，降低了细胞凋亡和炎症；而敲低 KLF2 则逆转了这一现象。这些发现表明，TRIM22 可能通过 NF-κB 信号通路促进 UC 中的疾病发展，并可被 KLF2 转录抑制。
