pH heterogeneity at intracellular and extracellular plasma membrane sites in HT29-Cl cell monolayers
pH heterogeneity at intracellular and extracellular plasma membrane sites in HT29-Cl cell monolayers
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DOI：
10.1152/ajpcell.2000.278.5.c973
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发表时间：
2000-05-01
影响因子：
5.5
通讯作者：
Montrose, MH
中科院分区：
文献类型：
--
作者：
Maouyo, D;Chu, S;Montrose, MH
在结肠粘膜中，短链脂肪酸改变细胞内pH（pH（i））和细胞外pH（pH（e））。在这份报告中，共聚焦显微镜和双发射率成像的carboxyseminaphthorhodofluor-1用于直接评估pH（i）和pH（e）在一个简单的模型上皮，HT 29-C1细胞。活细胞成像沿着的过滤器生长的细胞的顶部到基底轴允许同时测量的pH值在水环境中的顶膜，侧膜，和基膜附近。在等渗添加130 mM丙酸盐或30 mM NH 4Cl后，亚顶端细胞质报告了pH（i）的最大变化。在静息细胞和施加酸负荷的细胞中，侧膜的pH（i）值介于相对酸性的亚顶端区域（pH 6.3-6.9）和相对碱性的细胞基极（pH 7.4-7.1）之间。在诱导的碱性负荷期间，跨细胞pH（i）梯度减小或消除。丙酸盐差异改变pH值（e）附近的顶膜，在相邻细胞之间的侧细胞内空间，和附近的基膜。鲁米那或丙酸丝氨酸引起碱化的顺式室（丙酸被添加），但酸化的反式室仅在响应鲁米那丙酸。添加NH 4Cl会产生定性相反的pH（e）波动。pH（i）和pH（e）的微观值可以解释在存在跨上皮丙酸盐梯度的情况下在HT 29-C1细胞中观察到的极化Na/H交换剂的选择性活化的一部分。
In the colonic mucosa, short-chain fatty acids change intracellular pH (pH(i)) and extracellular pH (pH(e)). In this report, confocal microscopy and dual-emission ratio imaging of carboxyseminaphthorhodofluor-1 were used for direct evaluation of pH(i) and pH(e) in a simple model epithelium, HT29-C1 cells. Live cell imaging along the apical-to-basal axis of filter-grown cells allowed simultaneous measurement of pH in the aqueous environment near the apical membrane, the lateral membrane, and the basal membrane. Subapical cytoplasm reported the largest changes in pH(i) after isosmotic addition of 130 mM propionate or 30 mM NH4Cl. In resting cells and cells with an imposed acid load, lateral membranes had pH(i) values intermediate between the relatively acidic subapical region (pH 6.3-6.9) and the relatively alkaline basal pole of the cells (pH 7.4-7.1). Transcellular pH(i) gradients were diminished or eliminated during an induced alkaline load. Propionate differentially altered pH(e) near the apical membrane, in lateral intracellular spaces between adjacent cells, and near the basal membrane. Luminal or serosal propionate caused alkalinization of the cis compartment (where propionate was added) but acidification of the trans compartment only in response to luminal propionate. Addition of NH4Cl produced qualitatively opposite pH(e) excursions. The microscopic values of pH(i) and pH(e) can explain a portion of the selective activation of polarized Na/H exchangers observed in HT29-C1 cells in the presence of transepithelial propionate gradients.