Zhang Di, Yang Longfei, Su Weiheng, Zhao Yuan, Ma Xin, Zhou Haizhu, Xu Bo, Zhang Kaiqi, Ma Hongxia
Department of Basic Veterinary Medicine, College of Animal Science and Technology, Jilin Agricultural University, Changchun, China.
Jilin Provincial Key Laboratory on Molecular and Chemical Genetic, The Second Hospital of Jilin University, Changchun, China.
Front Microbiol. 2018 Jan 9;8:2655. doi: 10.3389/fmicb.2017.02655. eCollection 2017.
Enterotoxigenic (ETEC) are opportunistic pathogens that colonize the small intestine, produce enterotoxins and induce diarrhea. Some aquaporins (AQPs), such as AQP3 and AQP8, have been reported to participate in diarrhea by decreasing cellular influx in the gastrointestinal (GI) tract. AQP4 is another important water channel in the GI tract, but its role in ETEC-induced diarrhea has not been reported. Here, we demonstrated the potential roles of AQP4 in ETEC-induced diarrhea. Reverse transcription-polymerase chain reaction (RT-PCR) and western blotting showed that AQP4 was expressed in the mouse ileum, but not in the duodenum or jejunum while immunohistochemical staining showed that AQP4 localized to the basolateral membrane of ileum epithelial cells. Using an ETEC-induced mice diarrhea model, we demonstrated that both AQP4 mRNA level and the AQP4 protein level in the ileum decreased gradually over a time course of 7 days. These results suggest that AQP4 plays a role in the pathogenesis of ETEC-induced diarrhea by mediating water transport.
产肠毒素大肠杆菌（ETEC）是定殖于小肠、产生肠毒素并引发腹泻的机会致病菌。据报道，一些水通道蛋白（AQP），如AQP3和AQP8，通过减少胃肠道（GI）中的细胞内流参与腹泻过程。AQP4是胃肠道中另一种重要的水通道蛋白，但其在ETEC诱导的腹泻中的作用尚未见报道。在此，我们证明了AQP4在ETEC诱导的腹泻中的潜在作用。逆转录-聚合酶链反应（RT-PCR）和蛋白质印迹法显示，AQP4在小鼠回肠中表达，但在十二指肠或空肠中不表达，而免疫组织化学染色显示AQP4定位于回肠上皮细胞的基底外侧膜。使用ETEC诱导的小鼠腹泻模型，我们证明在7天的时间过程中，回肠中的AQP4 mRNA水平和AQP4蛋白水平均逐渐下降。这些结果表明，AQP4通过介导水转运在ETEC诱导的腹泻发病机制中发挥作用。
