紧密连接蛋白claudin-1,-2,-4在恶唑酮致大鼠溃疡性结肠炎肠组织上皮的表达改变及其意义

发布时间：2018-08-19 17:55

【摘要】：目的:炎症性肠病(inflammatory bowel disease)是一种慢性非特异的肠道炎症病变,包括溃疡性结肠炎(ulcerative colitis,UC)和克罗恩病(Crohn’s disease,CD)。大量试验研究表明,溃疡性结肠炎导致的肠黏膜损伤伴随着紧密连接结构的破坏,与炎症黏膜紧密连接蛋白的变化有关,了解溃疡性结肠炎肠黏膜屏障功能的改变对于研究溃疡性结肠炎的病因,寻求新的诊断治疗方法具有重要意义。方法:将40只Wister雌性大鼠随机分为正常对照组20只,恶唑酮(OXZ)模型组20只,采用7.5mg/ml恶唑酮给模型组大鼠灌肠,模拟溃疡性结肠炎模型,等量生理盐水灌肠做为对照组,造模后每天观察大鼠每天饮食、体重变化、大便性状及潜血情况,评价各组大鼠疾病活动指数;7天后,采集大鼠血液及结肠标本备检,观察并评价结肠黏膜损伤指数及组织病理学活动指数分别通过免疫组化和Western blot方法检测紧密连接蛋白claudin-1,-2,-4及Real-time PCR方法检测claudin-1,-2,-4 m RNA的表达情况并用ELISA方法检测结肠组织以及血清中细胞因子TNF-α,IL-4,IL-5,IL-10表达。结果:与正常对照组相比,OXZ模型组大鼠在1~3 d内出现大便次数增多、软便或稀便、大便末端有黏液或脓点,肛周有粪便粘黏等表现,少数有血性腹泻、毛发无光泽、体重下降,4只大鼠因症状严重而于3d左右死亡;正常对照组10只大鼠反应灵活、饮食量正常、体重增加,均无腹泻及血便。OXZ导致的溃疡性结肠炎大鼠模型组结肠组织损伤评分显著增加(P0.05),结肠组织以及血清IL-4和IL-5表达水平显著升高(P0.05);结肠组织中claudin-2表达明显高于正常对照组(P0.05),而claudin-1和claudin-4表达则不同程度低于正常对照组(P0.05)。结论:恶唑酮诱导实验性溃疡性结肠炎大鼠紧密连接膜微区的紧密连接蛋白claudin-1,-2,-4的分布和表达变化,表明溃疡性结肠炎中,紧密连接膜微区的紧密连接蛋白可能受到了影响,导致肠黏膜屏障功能受损,这一特点可能在溃疡性结肠炎中有潜在的诊断治疗意义。
[Abstract]:Objective: inflammatory bowel disease (inflammatory bowel disease) is a chronic nonspecific inflammatory disease of the intestine, including ulcerative colitis (ulcerative colitis) and Crohn's disease (CD). A large number of experimental studies have shown that intestinal mucosal damage caused by ulcerative colitis is associated with the destruction of tight junction structure, which is related to the change of inflammatory mucosal tight junction protein. It is important to understand the changes of intestinal mucosal barrier function in ulcerative colitis for studying the etiology of ulcerative colitis and seeking new diagnostic and therapeutic methods. Methods: forty female Wister rats were randomly divided into normal control group (n = 20) and oxazolone (OXZ) model group (n = 20). Rats in the model group were enema with 7.5mg/ml oxazolone to simulate ulcerative colitis. After modeling, the rats were observed daily diet, weight change, stool traits and occult blood. After 7 days of evaluating the disease activity index of rats in each group, blood and colon samples were collected. The colonic mucosal injury index and histopathological activity index were observed and evaluated respectively by immunohistochemical and Western blot methods to detect the expression of claudin-1m-2 RNA in colonic tissues and claudin-1m-2 RNA in colonic tissues detected by Real-time PCR method. The expression of claudin-1m-2 RNA in colonic tissues was detected by ELISA method. The cytokines TNF- 伪, IL-4, IL-5 and IL-10 were expressed in the tissue and serum. Results: compared with the normal control group, the rats in the OXZ model group had increased defecation times, soft or dilute stool, mucus or purulent point at the end of defecation, mucilage around the anus, and a few cases of bloody diarrhea, and the hair had no gloss. Four rats died of severe symptoms in 3 days or so, while 10 rats in the normal control group had a flexible response, normal diet and weight gain. No diarrhea and blood stool. OXZ induced ulcerative colitis model group colonic tissue injury score significantly increased (P0.05), colon tissue and serum IL-4 and IL-5 expression level significantly increased (P0.05), colon tissue claudin-2 expression was significantly higher than normal. The expression of claudin-1 and claudin-4 was lower in the radiation group (P0.05) than that in the normal control group (P0.05). Conclusion: the distribution and expression changes of claudin-1m-2 tip-4 in rat model of experimental ulcerative colitis, indicating that the tight junction protein in the microdomain of tight junction membrane may be affected in ulcerative colitis. This may have potential diagnostic and therapeutic significance in ulcerative colitis.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R574.62

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