Priyamvada Shubha, Gomes Rochelle, Gill Ravinder K, Saksena Seema, Alrefai Waddah A, Dudeja Pradeep K
*Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois; and †Jesse Brown VA Medical Center, Chicago, Illinois.
Inflamm Bowel Dis. 2015 Dec;21(12):2926-35. doi: 10.1097/MIB.0000000000000504.
Inflammatory bowel diseases (IBDs), including Crohn's disease and ulcerative colitis, are chronic relapsing inflammatory disorders of the gastrointestinal tract. Chronic inflammation of the intestine affects the normal fluid and electrolyte absorption leading to diarrhea, the hallmark symptom of IBD. The management of IBD-associated diarrhea still remains to be a challenge, and extensive studies over the last 2 decades have focused on investigating the molecular mechanisms underlying IBD-associated diarrhea. These studies have shown that the predominant mechanism of diarrhea in IBD involves impairment of electroneutral NaCl absorption, with very little role if any played by anion secretion. The electroneutral NaCl absorption involves coupled operation of Na/H exchanger 3 (NHE3 or SLC9A3) and Cl/HCO3 exchanger DRA (Down Regulated in Adenoma, or SLC26A3). Increasing evidence now supports the critical role of a marked decrease in NHE3 and DRA function and/or expression in IBD-associated diarrhea. This review provides a detailed analysis of the current knowledge related to alterations in NHE3 and DRA function and expression in IBD including the mechanisms underlying these observations and highlights the potential of these transporters as important and novel therapeutic targets.
炎症性肠病(IBDs),包括克罗恩病和溃疡性结肠炎,是胃肠道的慢性复发性炎症性疾病。肠道的慢性炎症会影响正常的液体和电解质吸收,导致腹泻,这是IBD的标志性症状。IBD相关性腹泻的治疗仍然是一个挑战,在过去20年里,广泛的研究集中在调查IBD相关性腹泻的分子机制。这些研究表明,IBD中腹泻的主要机制涉及电中性NaCl吸收受损,阴离子分泌即使有作用也非常小。电中性NaCl吸收涉及钠/氢交换体3(NHE3或SLC9A3)和氯/碳酸氢根交换体DRA(腺瘤下调蛋白,或SLC26A3)的协同作用。越来越多的证据支持NHE3和DRA功能和/或表达显著降低在IBD相关性腹泻中起关键作用。这篇综述详细分析了目前与IBD中NHE3和DRA功能及表达改变相关的知识,包括这些观察结果背后的机制,并强调了这些转运蛋白作为重要且新颖的治疗靶点的潜力。