Molecular Identification and Functional Characterization of the Vitamin C Transporters Expressed by Sertoli Cells
Molecular Identification and Functional Characterization of the Vitamin C Transporters Expressed by Sertoli Cells
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DOI：
10.1002/jcp.21545
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发表时间：
2008-12-01
影响因子：
5.6
通讯作者：
Concha, Ilona I.
中科院分区：
文献类型：
--
作者：
Angulo, Constanza;Castro, Maite A.;Concha, Ilona I.
维生素C是男性生殖细胞发育所必需的微量营养素。在性腺中，生殖细胞通过血-睾丸屏障与体循环隔离，血-睾丸屏障由支持细胞的基底层组成，支持细胞通过大量紧密连接复合物进行通信。为了研究支持细胞的行为作为维生素C转运蛋白在此屏障中的分子和功能表征的第一种方法，我们使用了从小鼠支持细胞永生化的42GPA 9细胞系。到目前为止，还没有关于维生素C穿过血-睾丸屏障转运机制的信息。这项工作描述了参与维生素C在这些细胞中运输的转运蛋白的分子身份，我们希望这将提高我们对生殖细胞如何获得维生素C，从血浆运输到曲细精管的近腔室的理解。RT-PCR分析显示，42GPA9细胞表达两种维生素C转运系统，这一发现得到了免疫细胞化学和免疫印迹分析的证实。使用放射性维生素C的动力学测定显示，抗坏血酸（AA）转运蛋白，SVCT I和SVCT 2，是功能活性的。此外，脱氢抗坏血酸（DHA）和3-甲基葡萄糖（OMG）运输的动力学特征由42 GPA 9支持细胞对应于促进己糖转运蛋白GLUT 1 GLUT 2和GLUT 3在这些细胞中表达。该数据与支持细胞具有摄取维生素C的能力的概念一致。这是一个重要的发现，有助于我们了解男性生殖细胞的生理学。
Vitamin C is an essential micronutrient for the development of male germ cells. In the gonad, the germ cells are isolated from the systemic circulation by the blood-testis barrier, which consists of a basal layer of Sertoli cells that communicate through an extensive array of tight junction complexes. To study the behavior of Sertoli cells as a first approach to the molecular and functional characterization of the vitamin C transporters in this barrier, we used the 42GPA9 cell line immortalized from mouse Sertoli cells. To date, there is no available information on the mechanism of vitamin C transport across the blood-testis barrier. This work describe the molecular identity of the transporters involved in vitamin C transport in these cells, which we hope will improve our understanding of how germ cells obtain vitamin C, transported from the plasma into the adluminal compartment of the seminiferous tubules. RT-PCR analyses revealed that 42GPA9 cells express both vitamin C transport systems, a finding that was confirmed by immunocytochemical and immunoblotting analysis. The kinetic assays using radioactive vitamin C revealed that both ascorbic acid (AA) transporters, SVCT I and SVCT2, are functionally active. Moreover, the kinetic characteristics of dehydroascorbic acid (DHA) and 3-methylglucose (OMG) transport by 42GPA9 Sertoli cells correspond to facilitative hexose transporters GLUT1 GLUT2 and GLUT3 expressed in these cells. This data is consistent with the concept that Sertoli cells have the ability to take up vitamin C. It is an important finding and contributes to our knowledge of the physiology of male germ cells.