ACE2-Ang(1-7)-Mas信号通路在非甾体抗炎药相关肠病中的作用及云母微化颗粒干预机制研究

Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used in clinical practice,and NSAIDs-related intestinal injury has become a common and serious complication.However,the pathogenesis remains unclear, and it lacks effective prevention and treatment method in clinical.In recent years, as renin angiotensin system's second metabolic shaft, ACE2-Ang(1-7)-Mas axis have the function of antagonizing angiotensin Ⅱ, and inhibiting the inflammatory response in tissue.Up to now, few studies have been reported about the relationship between RAS and small intestinal mucosa injury and protection at home and abroad.Our preliminary studies have found that intestinal mucosa have the expression change of ACE2 and AngⅡin the model of diclofenac-related intestinal injury in rats. in addition,mica micro change particle can significantly reduce the mucosa injury in rat small intestine.So,we have the reason to speculate that ACE2-Ang(1-7)-Mas signaling pathways play an important role in non-steroidal anti-inflammatory drug related bowel disease, and probably to become a potential targets for intervention. This study will from the level of cell and animal to build a special cell lines and mice that respectively overexpress of ACE2 by plasmid transfection and ACE2 gene knockout.In order to clarify the role of ACE2-Ang(1-7)-Mas signaling pathways in NSAIDs related bowel disease and it's regulating effect on the inflammatory cytokines, and intervention mechanism of mica micro change particle,and reveal NSAIDs related bowel disease pathogenesis,and provide experiment basis for clinical effective prevention and control, follow-up studies.

非甾体抗炎药(NSAIDs)临床应用广泛，其相关肠病已成为常见和严重的并发症，但目前发病机制仍不明确，临床缺乏有效防治手段。近年发现ACE2-Ang (1-7)-Mas作为RAS第2代谢轴，可拮抗AngⅡ，抑制组织炎症反应。但RAS与小肠损伤、保护的研究，国内外鲜有报道。我们前期研究发现双氯芬酸小肠损伤大鼠肠黏膜有ACE2、AngⅡ表达变化，云母微化颗粒可减轻大鼠小肠黏膜损伤，推测ACE2-Ang(1-7)-Mas信号通路在非甾体抗炎药相关肠病中有重要作用，有可能成为NSAIDs肠病防治潜在的干预靶点。本研究通过质粒转染构建过表达ACE2细胞株及ACE2基因敲除小鼠，从细胞及动物水平阐明ACE2-Ang (1-7)-Mas信号通路在NSAIDs肠病中的作用及对炎症因子表达的调控、云母微化颗粒的保护及机制，揭示NSAIDs肠病可能的发病机制，为临床有效防治及后续研究提供实验依据。

非甾体抗炎药(NSAIDs)临床应用广泛，其相关肠病成为常见和严重并发症，目前发病机制仍不明确，临床缺乏有效防治手段。RAS是体内重要的体液调节系统，在心血管及体液平衡调控中起着重要作用，研究发现胃肠道亦存在着局部经典RAS，并且参与了胃肠道的炎症反应，近年还发现ACE2-Ang (1-7)-Mas作为RAS第2代谢轴，可拮抗AngⅡ，抑制组织炎症反应。但RAS与NSAIDs相关小肠损伤的发生发展是否相关，国内外鲜有报道。我们的研究发现双氯芬酸小肠损伤大鼠肠黏膜有ACE2、AngⅡ表达变化，云母微化颗粒可减轻大鼠小肠黏膜损伤，推测ACE2-Ang(1-7)-Mas信号通路在非甾体抗炎药相关肠病中有重要作用，有可能成为NSAIDs肠病防治潜在的干预靶点。本研究通过质粒转染构建过表达ACE2细胞株，证实过表达ACE2可以降低双氯芬酸钠模型组的细胞凋亡率、渗透性增大的幅度及AngⅡ和IL-8的水平，从而减轻双氯芬酸钠所致IEC-6的损伤程度。同时发现ACE2-Ang（1-7）-Mas轴可拮抗双氯芬酸钠刺激IEC-6产生的p-p38MAPK、TNF-a、IL-8等炎症介质，且该作用可被ACE2拮抗剂DX600及MasR拮抗剂A779阻断。采用ACE2激动剂、ACE2抑制剂、MasR拮抗及云母干预大鼠NSAIDs相关小肠损伤模型，证实大鼠小肠组织中存在ACE2-Ang(1-7)-Mas轴，抑制AngⅡ、p-p38MAPK、TNF-α、ICAM-1表达、NF-κB活化。且发现云母对大鼠双氯芬酸钠相关小肠损伤具有保护作用，其机制可能与上调ACE2-Ang（1-7）-Mas轴，抑制AngⅡ、p-p38MAPK、TNF-α、ICAM-1表达相关，从而减轻炎症反应。本研究从细胞及动物水平建立双氯芬酸小肠损伤模型，从基因到蛋白水平，首次揭示ACE2-Ang(1-7)-Mas信号通路在NSAIDs肠病中的作用及云母微化颗粒探讨了ACE2-Ang(1-7)-Mas轴对双氯芬酸钠干预IEC-6后炎症因子的产生及其对p38MAPK信号转导途径的影响。阐明ACE2-Ang (1-7)-Mas信号通路在NSAIDs肠病中的作用及机制，揭示NSAIDs肠病可能的发病机制，明确该轴在非甾类抗炎药所致的小肠损伤中的保护作用及其作用机制，从而为临床有效防治NSAIDs肠病提供新的靶点和实验依据。