Kozan Philip A, McGeough Matthew D, Peña Carla A, Mueller James L, Barrett Kim E, Marchelletta Ronald R, Sivagnanam Mamata
Division of Gastroenterology, Department of Medicine, University of California San Diego, San Diego, CA, USA.
J Mol Med (Berl). 2015 May;93(5):535-45. doi: 10.1007/s00109-014-1239-x. Epub 2014 Dec 9.
Congenital tufting enteropathy (CTE) is a devastating diarrheal disease seen in infancy that is typically associated with villous changes and the appearance of epithelial tufts. We previously found mutations in epithelial cell adhesion molecule (EpCAM) to be causative in CTE. We developed a knock-down cell model of CTE through transfection of an EpCAM shRNA construct into T84 colonic epithelial cells to elucidate the in vitro role of EpCAM in barrier function and ion transport. Cells with EpCAM deficiency exhibited decreased electrical resistance, increased permeability, and decreased ion transport. Based on mutations in CTE patients, an in vivo mouse model was developed, with tamoxifen-inducible deletion of exon 4 in Epcam resulting in mutant protein with decreased expression. Tamoxifen treatment of Epcam (Δ4/Δ4) mice resulted in pathological features of villous atrophy and epithelial tufts, similar to those in human CTE patients, within 4 days post induction. Epcam (Δ4/Δ4) mice also showed decreased expression of tight junctional proteins, increased permeability, and decreased ion transport in the intestines. Taken together, these findings reveal mechanisms that may underlie disease in CTE.
Knock-down EpCAM cell model of congenital tufting enteropathy was developed. In vivo inducible mouse model was developed resulting in mutant EpCAM protein. Cells with EpCAM deficiency demonstrated barrier and ion transport dysfunction. Tamoxifen-treated Epcam (Δ4/Δ4) mice demonstrated pathological features. Epcam (Δ4/Δ4) mice showed improper barrier function and ion transport.
先天性簇状肠病（CTE）是一种在婴儿期出现的严重腹泻疾病，通常与绒毛变化和上皮簇的出现有关。我们之前发现上皮细胞粘附分子（EpCAM）的突变是CTE的病因。我们通过将EpCAM短发夹RNA构建体转染到T84结肠上皮细胞中，建立了CTE的敲低细胞模型，以阐明EpCAM在体外屏障功能和离子转运中的作用。EpCAM缺乏的细胞表现出电阻降低、通透性增加和离子转运减少。基于CTE患者的突变，开发了一种体内小鼠模型，通过他莫昔芬诱导Epcam外显子4缺失，导致突变蛋白表达降低。对Epcam（Δ4/Δ4）小鼠进行他莫昔芬治疗后，在诱导后4天内出现了绒毛萎缩和上皮簇的病理特征，类似于人类CTE患者。Epcam（Δ4/Δ4）小鼠还表现出肠道紧密连接蛋白表达降低、通透性增加和离子转运减少。综上所述，这些发现揭示了CTE疾病可能的潜在机制。
建立了先天性簇状肠病的敲低EpCAM细胞模型。开发了体内诱导小鼠模型，产生突变的EpCAM蛋白。EpCAM缺乏的细胞表现出屏障和离子转运功能障碍。他莫昔芬治疗的Epcam（Δ4/Δ4）小鼠表现出病理特征。Epcam（Δ4/Δ4）小鼠表现出屏障功能和离子转运异常。
