KGF对肠上皮细胞IL-7表达调控及对缺血再灌注损伤条件下肠黏保护作用及其机制研究-杨桦..docx

KGF对肠上皮细胞IL-7表达调控及对缺血再灌注损伤条件下肠黏保护作用及其机制研究邱远，蔡瑜娇，王文生，陈国庆，许超，孙力华，肖卫东，杨桦*【摘要】目的 肠道急性缺血再灌注（ischemia/reperfusion, I/R）损伤可引起肠黏膜上皮细胞脱落，肠黏膜通透性增加，引起细菌、毒素入血，从而引发严重的并发症。尽管已知角质生长因子(KGF)对肠黏膜细胞生长具有重要作用，但其在肠道急性I/R损伤中的作用及机制尚不清楚。 方法 肠梗阻病例的肠道组织用于形态学分析，并用免疫荧光的方法检测IL-7的表达。用KGF作用LoVo细胞和C57BL/6J小鼠。用WB和免疫荧光的方法检测KGF、KGF受体（KGFR）及IL-7的表达。结果 肠梗阻致缺血肠道KGF，IL-7表达下调；在体内和体外研究中发现，KGF可上调IL-7的表达；在LoVo细胞中，KGF作用引起磷酸化STAT1表达升高，用雷帕霉素或AG490阻断后，KGF的作用不能上调磷酸化STAT1和IL-7的表达；同时，KGF可上调IRF-1和IRF-2的表达；KGF可以显著改善急性I/R所致的肠黏膜形态的损伤及紧密连接蛋白正常表达结构的破坏。结论 在急性I/R小鼠模型中，KGF对I/R所致的肠黏膜形态及肠黏膜屏障功能损伤具有明确的保护作用。KGF可上调IL-7的表达，这一调控是通过KGFR/STAT1/ IRF-1, IRF-2通路实现的。本研究首次提出KGF通过KGFR/STAT1/ IRF-1, IRF-2通路调控IL-7的表达，并参与调节肠黏膜屏障功能。【关键词】角质细胞生长因子（KGF）；白介素7（IL-7）；缺血再灌注（I/R），小鼠，肠上皮细胞；肠黏膜屏障功能；信号传导与转录活化因子(STAT1)；干扰素调控因子1和2（IRF-1, IRF-2）Keratinocyte Growth Factor-induced Signals Up-regulate Interleukin-7 Production and Improve Intestinal Structure and Function in Intestinal Ischemia/Reperfusion InjuryYuan Qiu, Yujiao Cai , Wensheng Wang, Guoqing Chen, Chao Xu, Lihua Sun, Weidong Xiao, Hua Yang*Backgrond Aims: The pathogenesis of intestinal ischemia/reperfusion (I/R) is believed to involve an alteration of epithelial structure and function. Keratinocyte Growth Factor (KGF) mediates the enterocyte mitosis and increases intestinal growth. We have investigated the role KGF plays in regulating intestinal epithelium homeostasis in response to I/R injury. Methods: KGF and IL-7 expression were evaluated in intestinal tissue samples from patients with intestinal obstruction. LoVo cells and adult C57BL/6J mice were treated with KGF. Expression of P-Tyr-STAT1, STAT1, and IL-7 by inhibiting STAT1 and alterations of expression of IRF-1, IRF-2 and IL-7 were measured with western blot. Epithelial cell (EC) proliferation and apoptosis were assessed. Tight junctions (TJ) were detected by western blot and immunohistochemistry. Results: Intestine tissue from patients with intestinal obstruction expressed significantly less KGF and IL-7 than controls. KGF treatment le