NHE8 plays important roles in gastric mucosal protection.
NHE8 plays important roles in gastric mucosal protection.
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DOI：
10.1152/ajpgi.00433.2012
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发表时间：
2013-02
期刊：
影响因子：
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通讯作者：
Hua Xu;Jing Li;Huacong Chen;Chunhui Wang;F. Ghishan
中科院分区：
文献类型：
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作者：
Hua Xu;Jing Li;Huacong Chen;Chunhui Wang;F. Ghishan
钠/氢交换器（NHE）8是肠上皮细胞中顶端表达的膜蛋白。它在肠道中的钠吸收和碳酸氢盐分泌中起重要作用。虽然在胃中检测到NHE 8 mRNA，但NHE 8在胃腺中的确切位置和生理作用仍不清楚。在本研究中，我们成功地检测到NHE 8的表达在腺区域的胃和定位NHE 8蛋白在顶端膜的表面粘液细胞通过共聚焦显微镜方法。我们还确定了在胃的表面粘液细胞中下调的腺瘤（downregulated-in-adenoma，EAE）的表达。使用NHE 8（-/-）小鼠，我们发现NHE 8在基础胃酸产生中起很少或没有作用，然而NHE 8（-/-）小鼠具有降低的胃粘膜表面pH和更高的胃溃疡发生率。在NHE 8（-/-）小鼠中，在胃中的NH3表达显著降低。胃溃疡的倾向，粘膜表面pH值降低，和低表达表明，NHE 8是间接参与胃碳酸氢盐分泌和胃粘膜保护。
Sodium/hydrogen exchanger (NHE) 8 is an apically expressed membrane protein in the intestinal epithelial cells. It plays important roles in sodium absorption and bicarbonate secretion in the intestine. Although NHE8 mRNA has been detected in the stomach, the precise location and physiological role of NHE8 in the gastric glands remain unclear. In the current study, we successfully detected the expression of NHE8 in the glandular region of the stomach by Western blotting and located NHE8 protein at the apical membrane in the surface mucous cells by a confocal microscopic method. We also identified the expression of downregulated-in-adenoma (DRA) in the surface mucous cells in the stomach. Using NHE8(-/-) mice, we found that NHE8 plays little or no role in basal gastric acid production, yet NHE8(-/-) mice have reduced gastric mucosal surface pH and higher incidence of developing gastric ulcer. DRA expression was reduced significantly in the stomach in NHE8(-/-) mice. The propensity for gastric ulcer, reduced mucosal surface pH, and low DRA expression suggest that NHE8 is indirectly involved in gastric bicarbonate secretion and gastric mucosal protection.