Carmosino M, Procino G, Casavola V, Svelto M, Valenti G
Dipartimento di Fisiologia Generale ed Ambientale, Bari, Italy.
Pflugers Arch. 2000 Oct;440(6):871-80. doi: 10.1007/s004240000363.
HGT-1 is a human cell line sharing a number of physiological features with gastric parietal cells. HGT-1 cell monolayers were able to secrete H+ when stimulated with histamine (calculated external pH variation, deltapH(e) 0.46+/-0.05) as assessed using the impermeant, pH-sensitive fluorescence dye 8-hydroxypyrene-1,3,6-trisulphonic acid, trisodium salt (HPTS). Treatment with 100 microM omeprazole inhibited the histamine-induced apical acidification by about 60%. Intracellular pH (pH(i)) measurements using the fluorescent pH-sensitive dye 2',7'-bis-carboxyethyl-5(6)-carboxyfluorescein (BCECF) demonstrated the expression of a functional, omeprazole-sensitive H+/K+-pump. A monoclonal antibody directed against the alpha subunit of the H+/K+-ATPase immunoprecipitated a 95-kDa protein from HGT-1 cells and human stomach which corresponds to the expected molecular size of the native protein. HGT-1 cells were also positive for the anion exchanger AE2 that is expressed in gastric parietal cells. In addition, we identified a histamine- and pH(i)-sensitive Na+/H+ exchanger in HGT-1 cells, which might correspond to the functional expression of the NHE4 isoform that has been detected in gastric epithelial cells as well as in primary cultured parietal cells. HGT-1 cells therefore display the principal features of parietal cells and might represent an interesting cell culture model for studying the regulatory mechanisms involved in acid secretion.
HGT-1是一种人类细胞系，与胃壁细胞具有许多生理特征。使用非渗透性、pH敏感的荧光染料8-羟基芘-1,3,6-三磺酸三钠盐（HPTS）评估发现，HGT-1细胞单层在受到组胺刺激时能够分泌H⁺（计算得出细胞外pH变化，ΔpH(e)为0.46±0.05）。用100微摩尔奥美拉唑处理可使组胺诱导的顶端酸化抑制约60%。使用荧光pH敏感染料2',7'-双羧乙基-5(6)-羧基荧光素（BCECF）测量细胞内pH（pH(i)），证明存在一种功能性的、对奥美拉唑敏感的H⁺/K⁺泵。一种针对H⁺/K⁺-ATP酶α亚基的单克隆抗体从HGT-1细胞和人胃中免疫沉淀出一种95 kDa的蛋白质，其大小与天然蛋白质的预期分子大小相符。HGT-1细胞对在胃壁细胞中表达的阴离子交换蛋白AE2也呈阳性。此外，我们在HGT-1细胞中鉴定出一种对组胺和pH(i)敏感的Na⁺/H⁺交换体，它可能对应于在胃上皮细胞以及原代培养的壁细胞中检测到的NHE4亚型的功能性表达。因此，HGT-1细胞表现出壁细胞的主要特征，可能是研究胃酸分泌相关调节机制的一个有趣的细胞培养模型。
