Activation of focal adhesion kinase via M1 muscarinic acetylcholine receptor is required in restitution of intestinal barrier function after epithelial injury
Activation of focal adhesion kinase via M1 muscarinic acetylcholine receptor is required in restitution of intestinal barrier function after epithelial injury
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DOI：
10.1016/j.bbadis.2013.12.007
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发表时间：
2014-04-01
影响因子：
6.2
通讯作者：
Taniguchi, Takanobu
中科院分区：
文献类型：
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作者：
Khan, Md Rafigul Islam;Yazawa, Takashi;Taniguchi, Takanobu
在包括炎性肠病（IBD）在内的各种肠道疾病中观察到上皮屏障受损。许多因素可能导致肠上皮细胞的暂时性损伤。高度发散因子的复杂网络调节上皮的愈合以防止炎症反应。然而，确切的修复机制参与维持稳态肠屏障的完整性仍有待澄清。在这项研究中，我们证明，M1毒蕈碱乙酰胆碱受体（mAChR）的激活增强恢复上皮屏障功能的T84细胞单层乙醇诱导的上皮损伤后，通过ERK依赖的磷酸化粘着斑激酶（FAK）。我们已经发现，乙醇损伤降低跨上皮电阻（TER）沿着ERK和FAK磷酸化的减少。卡巴胆碱（CCh）增加ERK和FAK磷酸化，增强TER恢复，这是完全阻断MT-7（M1拮抗剂）或阿托品。CCh诱导的TER恢复的增强也被U 0126（ERK通路抑制剂）或PF-228（FAK抑制剂）阻断。用干扰素-γ（IFN-γ）处理T84细胞单层损害了屏障功能，降低了FAK磷酸化。CCh诱导的ERK和FAK磷酸化也被IFN-γ处理减弱。免疫学和结合实验显示IFN-γ处理后M1 mAChR显著减少。免疫组化结果显示，IBD患者手术标本中M1 mAChR表达明显减少。这些研究结果提供了重要的线索机制，M1 mAChR参与维持肠道屏障功能，不仅在生理条件下，而且在病理条件下。(C)2013爱思唯尔有限公司版权所有。
Impairment of epithelial barrier is observed in various intestinal disorders including inflammatory bowel diseases (IBD). Numerous factors may cause temporary damage of the intestinal epithelium. A complex network of highly divergent factors regulates healing of the epithelium to prevent inflammatory response. However, the exact repair mechanisms involved in maintaining homeostatic intestinal barrier integrity remain to be clarified. In this study, we demonstrate that activation of M1 muscarinic acetylcholine receptor (mAChR) augments the restitution of epithelial barrier function in T84 cell monolayers after ethanol-induced epithelial injury, via ERK-dependent phosphorylation of focal adhesion kinase (FAK). We have shown that ethanol injury decreased the transepithelial electrical resistance (TER) along with the reduction of ERK and FAK phosphorylation. Carbachol (CCh) increased ERK and FAK phosphorylation with enhanced TER recovery, which was completely blocked by either MT-7 (M1 antagonist) or atropine. The CCh-induced enhancement of TER recovery was also blocked by either U0126 (ERK pathway inhibitor) or PF-228 (FAK inhibitor). Treatment of T84 cell monolayers with interferon-gamma (IFN-gamma) impaired the barrier function with the reduction of FAK phosphorylation. The CCh-induced ERK and FAK phosphorylation were also attenuated by the IFN-gamma treatment. Immunological and binding experiments exhibited a significant reduction of M1 mAChR after IFN-gamma treatment. The reduction of M1 mAChR in inflammatory area was also observed in surgical specimens from IBD patients, using immunohistochemical analysis. These findings provide important clues regarding mechanisms by which M1 mAChR participates in the maintenance of intestinal barrier function under not only physiological but also pathological conditions. (C) 2013 Elsevier B.V. All rights reserved.