Department of Central Laboratory, First Affiliated Hospital of Bengbu Medical University, Bengbu, 233000, China; Anhui Province Key Laboratory of Basic and Translational Research of Inflammation-related Diseases, Bengbu, 233000, China.
Anhui Province Key Laboratory of Basic and Translational Research of Inflammation-related Diseases, Bengbu, 233000, China; Department of Laboratory Medicine, Bengbu Medical University, Bengbu, 233000, China.
Chem Biol Interact. 2024 Nov 1;403:111222. doi: 10.1016/j.cbi.2024.111222. Epub 2024 Sep 4.
The unknown mechanism that controls intestinal barrier dysfunction in individuals with Crohn's disease (CD) plays a crucial role in the onset of intestinal inflammation. Testin, an intercellular linker protein, has the potential to protect epithelial barrier function. This study aimed to analyse the effects of Testin on CD-like colitis and explore the possible underlying mechanism. Colon samples from CD patients and trinitrobenzene-sulfonic acid (TNBS)-treated mice were collected to examine changes in Testin expression. To assess the therapeutic effects of Testin on CD-like colitis in mice, we examined the symptoms of enteritis, performed histological analysis, and evaluated intestinal barrier permeability. The ability of Testin to stabilize tight junction (TJ) proteins was investigated via immunofluorescence and western blotting. We conducted in vivo and in vitro experiments using colonic organoids and blocking techniques to explore how Testin safeguards the integrity of the intestinal barrier. Testin expression was downregulated in the colons of CD patients and TNBS-treated mice. Increasing Testin expression led to amelioration of colitis symptoms and reduced the production of inflammatory cytokines in the colons of TNBS-induced colitis model mice. Furthermore, increased Testin expression resulted in decreased depletion of TJ proteins (ZO-1 and Claudin-1) and promoted the effectiveness of the intestinal barrier in mice with TNBS-induced colon damage and in lipopolysaccharide (LPS)-stimulated colonic organoids. Elevated Testin levels inactivated the JNK/P38 signalling pathway, potentially contributing to the beneficial impact of Testin on the intestinal barrier. Testin can inhibit the loss of TJ proteins in CD mice by inactivating the JNK/P38 pathway. These findings help to clarify how Testin alleviates CD-like colitis in mice by protecting intestinal barrier function. These findings could lead to the use of a new treatment approach for CD in clinical practice.
未知的机制控制肠道屏障功能障碍在个体与克罗恩病(CD)在肠道炎症的发生中起着至关重要的作用。Testin，一种细胞间连接蛋白，有可能保护上皮细胞屏障功能。本研究旨在分析 Testin 对 CD 样结肠炎的影响，并探讨其可能的潜在机制。收集克罗恩病患者和三硝基苯磺酸(TNBS)处理的小鼠的结肠样本，以检测 Testin 表达的变化。为了评估 Testin 对 CD 样结肠炎小鼠的治疗效果，我们检查了肠炎的症状，进行了组织学分析，并评估了肠道屏障通透性。通过免疫荧光和 Western blot 检测 Testin 稳定紧密连接(TJ)蛋白的能力。我们通过使用结肠类器官和阻断技术进行体内和体外实验，探讨了 Testin 如何保护肠道屏障的完整性。Testin 在克罗恩病患者和 TNBS 处理的小鼠的结肠中表达下调。增加 Testin 的表达导致结肠炎症状的改善，并减少了 TNBS 诱导的结肠炎模型小鼠结肠中炎症细胞因子的产生。此外，增加 Testin 的表达导致 TJ 蛋白(ZO-1 和 Claudin-1)的耗竭减少，并促进了 TNBS 诱导的结肠损伤和脂多糖(LPS)刺激的结肠类器官中肠道屏障的有效性。Testin 水平的升高使 JNK/P38 信号通路失活，这可能是 Testin 对肠道屏障有益影响的原因。Testin 可以通过使 JNK/P38 通路失活来抑制 CD 小鼠 TJ 蛋白的丢失。这些发现有助于阐明 Testin 通过保护肠道屏障功能来减轻 CD 样结肠炎的机制。这些发现可能导致在临床实践中使用一种新的 CD 治疗方法。
