In situ hybridization and immunolocalization of concentrative and equilibrative nucleoside transporters in the human intestine, liver, kidneys, and placenta
In situ hybridization and immunolocalization of concentrative and equilibrative nucleoside transporters in the human intestine, liver, kidneys, and placenta
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DOI：
10.1152/ajpregu.00293.2007
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发表时间：
2007-11-01
影响因子：
2.8
通讯作者：
Unadkat, Jashvant D.
中科院分区：
文献类型：
--
作者：
Govindarajan, Rajgopal;Bakken, Aimee H.;Unadkat, Jashvant D.
为了更好地了解人体平衡（hENTs）和浓度（hCNT）核苷转运蛋白在生理学和药理学中的作用，我们研究了两种hCNT（hCNT1和hCNT2）和两种hENTs（hENT1和hENT2）在四种人体组织中的区域，细胞和空间分布。应用原位杂交和免疫组织化学技术，我们发现十二指肠肠上皮细胞表达hCNT1和hCNT2 mRNA，隐窝细胞表达hENT1和hENT2 mRNA。在这些细胞中，hCNT和hENT蛋白主要定位于顶膜和侧膜，分别。肝细胞表达hENT1，hCNT1和hENT2的mRNA水平高于hCNT2，并在肝细胞边界和细胞质中表达所有这些蛋白质。虽然肾脏表达hCNT1和hCNT2 mRNA在近端小管，hENT1和hENT2 mRNA存在于远端小管，肾小球，内皮细胞和血管平滑肌细胞。邻近皮髓质交界处的近端小管表达hENT1、hCNT1和hCNT2 mRNA。免疫定位研究显示，hCNT主要定位在近端肾小管上皮细胞的刷状缘膜和hENT在远端肾小管上皮细胞的基底外侧膜。人足月胎盘绒毛切片表达hENT1和hENT2的mRNA和蛋白质，但仅表达hCNT2的mRNA。免疫定位研究显示hENT1存在于合体滋养细胞的刷状缘膜中。这些数据对于更好地理解核苷转运体在核苷和核苷药物的生理和药理作用中的作用至关重要。
To better understand the role of human equilibrative (hENTs) and concentrative ( hCNTs) nucleoside transporters in physiology and pharmacology, we investigated the regional, cellular, and spatial distribution of two hCNTs (hCNT1 and hCNT2) and two hENTs (hENT1 and hENT2) in four human tissues. Using in situ hybridization and immunohistochemical techniques, we found that the duodenum expressed hCNT1 and hCNT2 mRNAs in enterocytes and hENT1 and hENT2 mRNAs in crypt cells. In these cells, the hCNT and hENT proteins were predominantly localized in the apical and lateral membrane, respectively. Hepatocytes expressed higher levels of mRNAs of hENT1, hCNT1, and hENT2 than of hCNT2 and expressed all these proteins at hepatocyte cell borders and in the cytoplasm. While the kidney expressed hCNT1 and hCNT2 mRNAs in the proximal tubules, hENT1 and hENT2 mRNAs were present in the distal tubules, glomeruli, endothelial cells, and vascular smooth muscle cells. Proximal tubules adjacent to corticomedullary junctions expressed hENT1, hCNT1, and hCNT2 mRNA. Immunolocalization studies revealed predominant localization of hCNTs in the brush-border membrane of the proximal tubular epithelial cells and hENTs in the basolateral membrane of the distal tubular epithelial cells. Chorionic villi sections of human term placenta expressed mRNAs and proteins for hENT1 and hENT2 but only mRNA for hCNT2. Immunolocalization studies showed presence of hENT1 in the brush-border membrane of the syncytiotrophoblasts. These data are critical for a better understanding of the role of nucleoside transporters in the physiological and pharmacological effects of nucleosides and nucleoside drugs, respectively.