Cell polarity-determining proteins Par-3 and PP-1 are involved in epithelial tight junction defects in coeliac disease
Cell polarity-determining proteins Par-3 and PP-1 are involved in epithelial tight junction defects in coeliac disease
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DOI：
10.1136/gutjnl-2011-300123
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发表时间：
2012-02-01
期刊：
影响因子：
24.5
通讯作者：
Schulzke, Joerg-Dieter
中科院分区：
文献类型：
--
作者：
Schumann, Michael;Guenzel, Dorothee;Schulzke, Joerg-Dieter
背景上皮屏障缺陷在乳糜泻中是众所周知的，但其机制尚不明确。目前尚不清楚屏障紊乱是否反映了上皮胞吞作用的上调或细胞旁渗漏。目的探讨上皮紧密连接（epithelial tight junction， TJ）的分子结构、功能及其失调机制。方法采用western blotting和电生理相关的共聚焦显微镜对参与TJ组装及其调控的蛋白进行分子分析。结果发现上皮TJ蛋白组成的复杂改变（有更多的形成孔的claudin-2和减少收紧claudin-3， -5和-7）导致蛋白表达和亚细胞定位，导致细胞旁生物素- nhs摄取增加。相比之下，上皮细胞凋亡仅中度升高（占屏障缺陷的一小部分），上皮大体病变（例如，细胞挤压区）不存在。这种TJ的改变与调节TJ组装的蛋白质、极性复合物蛋白Par-3和丝氨酸/苏氨酸磷酸酶PP-1的定位/表达改变有关。结论活动性乳糜泻患者细胞极性蛋白Par-3和PP-1的改变与TJ蛋白claudin-2、-3、-5、-7和ZO-1的表达和组装改变有关，引起细胞旁渗漏。
Background Epithelial barrier defects are well known in coeliac disease, but the mechanisms are only poorly defined. It is unclear, whether barrier disturbance reflects upregulated epithelial transcytosis or paracellular leakage.Objective To characterise the molecular structure and function of the epithelial tight junction (TJ) and mechanisms of its dysregulation.Methods Molecular analysis of proteins involved in TJ assembly and their regulation was performed by western blotting and confocal microscopy correlated to electrophysiology.Results A complex alteration of the composition of epithelial TJ proteins (with more pore-forming claudins like claudin-2 and a reduction in tightening claudins like claudin-3, -5 and -7) was found for protein expression and subcellular localisation, responsible for an increase in paracellular biotin-NHS uptake. In contrast, epithelial apoptosis was only moderately elevated (accounting for a minor portion of barrier defects) and epithelial gross lesions-for example, at cell extrusion zones, were absent. This TJ alteration was linked to an altered localisation/expression of proteins regulating TJ assembly, the polarity complex protein Par-3 and the serine-/threonine phosphatase PP-1.Conclusions Changes in cell polarity proteins Par-3 and PP-1 are associated with altered expression and assembly of TJ proteins claudin-2, -3, -5 and -7 and ZO-1, causing paracellular leakage in active coeliac disease.