TNFR2 activates MLCK-dependent tight junction dysregulation to cause apoptosis-mediated barrier loss and experimental colitis.
TNFR2 activates MLCK-dependent tight junction dysregulation to cause apoptosis-mediated barrier loss and experimental colitis.
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DOI：
10.1053/j.gastro.2013.04.011
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发表时间：
2013-08
期刊：
影响因子：
29.4
通讯作者：
Turner JR
中科院分区：
文献类型：
--
作者：
Su L;Nalle SC;Shen L;Turner ES;Singh G;Breskin LA;Khramtsova EA;Khramtsova G;Tsai PY;Fu YX;Abraham C;Turner JR
紧密连接失调和上皮损伤导致炎症性肠病（IBD）患者屏障丧失。然而，调节这些过程的机制及其对疾病发病机制的相对贡献还不完全清楚。我们使用小鼠结肠炎模型研究了这些过程。我们通过过继转移CD 4 + CD 45 RBhi细胞或给予葡聚糖硫酸钠（DSS）诱导小鼠结肠炎，包括肿瘤坏死因子受体（TNFR）1，TNFR 2或肌球蛋白轻链激酶（MLCK）长亚型缺陷的小鼠。肠组织和分离的上皮细胞进行了分析，免疫印迹，免疫荧光，ELISA和实时PCR检测。通过CD 4 + CD 45 RBhi过继转移诱导免疫介导的结肠炎增加了肠通透性;上皮细胞表达的claudin-2，MLCK的长亚型，和TNFR 2（但不是TNFR 1）;和肌球蛋白II轻链（MLC）的磷酸化。长MLCK上调，MLC磷酸化，屏障丧失，体重减轻在TNFR 2 −/−，但不是TNFR 1 −/−，野生型CD 4 + CD 45 RBhi细胞的受体中减弱。同样，长MLCK−/−小鼠的MLC磷酸化、claudin-2表达和肠通透性增加有限，细胞转移诱导的结肠炎发作延迟。然而，与上皮细胞凋亡的发生一致，最终发展为结肠炎。这表明，在缺乏MLCK依赖性紧密连接调节的情况下，疾病通过细胞凋亡进展。为了支持这一结论，长MLCK-/-小鼠并不能免受上皮细胞凋亡介导的、损伤依赖性DSS结肠炎的影响。在免疫介导的IBD模型中，TNFR 2信号传导增加长MLCK表达，导致紧密连接失调、屏障丧失和结肠炎诱导。在晚期，结肠炎通过细胞凋亡和粘膜损伤进展，导致紧密连接和MLCK非依赖性屏障丧失。因此，免疫介导的结肠炎中的屏障丧失通过两种时间和形态学上不同的机制发生。这些机制的差异靶向可能导致改善IBD疗法。
Tight junction dysregulation and epithelial damage contribute to barrier loss in patients with inflammatory bowel disease (IBD). However, the mechanisms that regulate these processes and their relative contributions to disease pathogenesis are incompletely understood. We investigated these processes using colitis models in mice. We induced colitis by adoptive transfer of CD4+CD45RBhi cells or administration of dextran sulfate sodium (DSS) to mice, including those deficient in tumor necrosis factor receptor (TNFR) 1, TNFR2, or the long isoform of myosin light chain kinase (MLCK). Intestinal tissues and isolated epithelial cells were analyzed by immunoblot, immunofluorescence, ELISA, and real-time PCR assays. Induction of immune-mediated colitis by CD4+CD45RBhi adoptive transfer increased intestinal permeability; epithelial expression of claudin-2, the long isoform of MLCK, and TNFR2 (but not TNFR1); and phosphorylation of the myosin II light chain (MLC). Long MLCK upregulation, MLC phosphorylation, barrier loss, and weight loss were attenuated in TNFR2−/−, but not TNFR1−/−, recipients of wildtype CD4+CD45RBhi cells. Similarly, long MLCK−/− mice had limited increases in MLC phosphorylation, claudin-2 expression, and intestinal permeability and delayed onset of cell transfer-induced colitis. However, coincident with onset of epithelial apoptosis, colitis ultimately developed. This indicates that disease progresses via apoptosis in the absence of MLCK-dependent tight junction regulation. In support of this conclusion, long MLCK−/− mice were not protected from epithelial apoptosis-mediated, damage-dependent DSS colitis. In immune-mediated IBD models, TNFR2 signaling increases long MLCK expression, resulting in tight junction dysregulation, barrier loss and induction of colitis. At advanced stages, colitis progresses by apoptosis and mucosal damage that results in tight junction- and MLCK-independent barrier loss. Therefore, barrier loss in immune-mediated colitis occurs via two temporally and morphologically distinct mechanisms. Differential targeting of these mechanisms may lead to improved IBD therapies.
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影响因子：
4.9
作者：
Stillie, RoseMarie;Stadnyk, Andrew W.
通讯作者：
Stadnyk, Andrew W.
影响因子：
29.4
作者：
Atreya, Raja;Zimmer, Michael;Neurath, Markus F.
通讯作者：
Neurath, Markus F.
影响因子：
29.4
作者：
Schwarz, Brad T.;Wang, Fengjun;Turner, Jerrold R.
通讯作者：
Turner, Jerrold R.
紧密的连接孔和泄漏途径：一个动态的二人组。
影响因子：
18.2
作者：
Shen L;Weber CR;Raleigh DR;Yu D;Turner JR
通讯作者：
Turner JR
影响因子：
29.4
作者：
He, Wei-Qi;Peng, Ya-Jing;Zhu, Min-Sheng
通讯作者：
Zhu, Min-Sheng