腹泻型肠易激综合征患者结肠黏膜AQP4、AQP8相关性表达

The expression of aquaporin 4 and aquaporin 8 in the human colon of diarrhea-predominant irritable bowel syndrome

目的检测正常人、腹泻型肠易激综合征(IBS)患者升、降结肠黏膜水通道蛋白(AQP)4与AQP8的表达情况,探讨AQP4、AQP8的表达与腹泻型IBS的相关性。方法采用荧光定量逆转录聚合酶链反应(FQ-RT-PCR)方法。结果AQP4在正常人、腹泻型IBS患者升结肠和降结肠所有标本的荧光生长曲线呈阴性,而AQP8的荧光生长曲线呈阳性。正常人和腹泻型IBS患者升结肠组织黏膜AQP8mRNA表达均显著高于降结肠(P=0.032,P=0.028);且无论在升结肠还是降结肠组织黏膜,腹泻型IBS患者AQP8 mNRA表达均显著低于正常人(P=0.030,P=0.012)。结论人体结肠组织中AQP4极少表达或无表达。生理状态下AQP8可能与结肠水吸收相关,腹泻型IBS的发生可能与AQP8的表达减少有一定相关性。

Objective To detect the expression levels of aquaporin4 （AQP4） and AQP8 in colons of diarrheapredominant irritable bowel syndrome （IBS） patients and normal controls and investigate the relationship between them and diarrhea-predominant IBS. Methods The quantities of AQP4 and AQP8 mRNA were detected with fluorogenic probe quantitative RT-PCR（FQ-RT-PCR） in colons of 30 diarrhea-predominant IBS patients and 32 healthy controls. Results Both in normal controls and diarrhea-predominant IBS patients the expression levels of AQP8 were significantly higher in the proximal colon than in the distal colon（ P = 0. 032 ,P = 0. 028 ）. Both in human proximal colon and the distal colon the expression levels of AQP8 were significantly higher in diarrhea-predominant IBS patients than in the normal controls（P = 0. 030, P = 0. 012）. Conclusion AQP4 is not expressed in human colon. AQP8 is expressed in human colon and it is correlated with the water absorption. The reduced expression level of AQP8 may be associated with the pathogenesis of diarrhea-predominant IBS.