Expression of multiple Na+/H+ exchanger isoforms in cultured epithelial cells from rat efferent duct and cauda epididymidis
Expression of multiple Na+/H+ exchanger isoforms in cultured epithelial cells from rat efferent duct and cauda epididymidis
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DOI：
10.1095/biolreprod64.2.482
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发表时间：
2001-02-01
影响因子：
3.6
通讯作者：
Wong, PYD
中科院分区：
文献类型：
--
作者：
Leung, GPH;Tse, CM;Wong, PYD
虽然早期的工作已经指出，存在的Na+/ H+交换（NHEs）在大鼠附睾，很少有人知道的区域分布的各种NHE异构体和它们的功能。在本工作中，不同亚型的NHE在培养的输出管和附睾尾上皮细胞的表达进行了研究。逆转录-聚合酶链反应显示，NHE 1，NHE 2和NHE 3的存在下，但不是NHE 4，在两个培养的上皮细胞的消息。Western blot分析检测到NHE 1和NHE 2蛋白在两种培养的上皮细胞中的存在，但NHE 3蛋白仅在培养的输出管上皮细胞中检测到。免疫组织化学研究表明，NHE 2定位于纤毛细胞的细胞质中，而NHE 3定位于输出管的主细胞的顶膜。10 μ M HOE-694（3-甲基磺酰基-4-哌啶基苯甲酰基胍甲磺酸盐）（一种NHE 1抑制剂）可抑制两种培养上皮细胞中的NHE活性约76%。20 μ M S3226（3-[2-（3-胍基-2-甲基-3-氧代-丙烯基）-5-甲基-苯基]-N-异亚丙基-2-甲基-丙烯酰胺二盐酸盐）（一种NHE 3抑制剂）和300 μ M HOE-694（可完全阻断NHE 2的剂量）分别完全抑制了培养的输出管和附睾尾上皮细胞中的HOE-694抗性NHE活性。这些结果表明，NHE 1、NHE 2和NHE 3在培养的输出管上皮细胞中表达，而NHE 1和NHE 2仅在培养的附睾尾上皮细胞中表达。这表明NHE 1可能在两种上皮中提供“管家”功能，而附睾尾中的NHE 2和输出管中的NHE 3可能参与Na+重吸收和腔液pH值的调节。
Although earlier work has pointed to the presence of Na+/ H+ exchangers (NHEs) in the rat epididymis, little is known about the regional distribution of various NHE isoforms and their functions. In the present work, expression of different isoforms of NHE in cultured epithelia of the efferent duct and cauda epdidymidis were studied. Reverse transcription-polymerase chain reaction revealed the presence of NHE1, NHE2, and NHE3, but not NHE4, message in both cultured epithelia. Western blot analysis detected the presence of NHE1 and NHE2 proteins in both cultured epithelia, but NHE3 protein was only detected in the cultured epithelial cells from the efferent duct. Immunohistochemical studies demonstrated that NHE2 was localized in the cytoplasm of the ciliated cells, whereas NHE3 was localized at the apical membrane of the principal cells of the efferent duct. The NHE activities in both cultured epithelia were inhibited by 10 muM HOE-694 (3-methylsulphonyl-4-piperidinobenzoyl guanidine methanesulphonate), a NHE1 inhibitor, by approximately 76%. The HOE-694-resistant NHE activities in the cultured epithelia of efferent duct and cauda epididymidis were completely inhibited by 20 muM S3226 (3-[2-(3-guanidino-2-methyl-3-oxo-propenyl)-5-methyl-phenyl]-N-isopropylidene-2-methyl-acrylamide dihydrochloride), a NHE3 inhibitor, and 300 muM HOE-694 (a dose that can completely block NHE2), respectively. These results indicated that NHE1, NHE2, and NHE3 were expressed in the cultured epithelial cells of the efferent duct, whereas only NHE1 and NHE2 were expressed in the cultured epithelial cells of the cauda epididymidis. It is suggested that NHE1 may provide "housekeeping" functions in both epithelia, whereas NHE2 in the cauda epididymidis and NHE3 in the efferent duct may be involved in Na+ reabsorption and regulation of pH of the luminal fluid.