Amino acid transport in podocytes
Amino acid transport in podocytes
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DOI：
10.1152/ajprenal.2000.278.6.f999
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发表时间：
2000-06-01
影响因子：
4.2
通讯作者：
Pavenstädt, H
中科院分区：
文献类型：
--
作者：
Gloy, J;Reitinger, S;Pavenstädt, H
最近有研究表明足细胞足突的形成依赖于脂质和蛋白质的恒定来源（Simons M, Saffrich R, Reiser J, and Mundel P. J, journal of clinical journal, 1999）。在这里，我们描述了氨基酸在分化培养足细胞中的转运机制，并研究了足细胞损伤过程中氨基酸转运机制是否受到干扰。RT-PCR研究检测了中性氨基酸（ASCT1、ASCT2和B0/+）、阳离子AA （CAT1和CAT3）和阴离子AA （EAAT2和EAAT3）转运体的mRNA。丙氨酸（Ala）、天冬氨酸、半胱氨酸（Cys）、谷氨酰胺（Gln）、甘氨酸（Gly）、亮氨酸（Leu）、蛋氨酸（Met）、苯丙氨酸（Phe）、脯氨酸（Pro）、丝氨酸（Ser）、苏氨酸（Thr）、谷氨酸（Glu）、精氨酸（Arg）和组氨酸（His）使足细胞去极化并增加其全细胞电导。细胞外Na+的消耗完全抑制了Ala、Gln、Glu、Gly、Leu和Pro诱导的去极化，降低了Arg和His诱导的去极化，表明存在依赖Na+的氨基酸转运。足细胞与100 μ g/ml嘌呤霉素氨基核苷孵育24 h后，各种氨基酸对足细胞的影响均明显减弱，降幅达70%。这些数据表明足细胞中存在不同的氨基酸转运系统。氨基酸转运的改变可能参与足细胞损伤和足突形成紊乱。
It has recently been shown that formation of podocyte foot processes is dependent on a constant source of lipids and proteins (Simons M, Saffrich R, Reiser J, and Mundel P. J Am Soc Nephrol 10: 1633-1639, 1999). Here we characterize amino acid transport mechanisms in differentiated cultured podocytes and investigate whether it may be disturbed during podocyte injury. RT-PCR studies detected mRNA for transporters of neutral amino acids (ASCT1, ASCT2, and B0/+), cationic AA (CAT1 and CAT3), and anionic AA (EAAT2 and EAAT3). Alanine (Ala), asparagine, cysteine (Cys), glutamine (Gln), glycine (Gly), leucine (Leu), methionine (Met), phenylalanine (Phe), proline (Pro), serine (Ser), threonine (Thr), glutamic acid (Glu), arginine (Arg), and histidine (His) depolarized podocytes and increased their whole cell conductances. Depletion of extracellular Na+ completely inhibited the depolarization induced by Ala, Gln, Glu, Gly, Leu, and Pro and decreased the depolarization induced by Arg and His, indicating the presence of Na+-dependent amino acid transport. Incubation of podocytes with 100 mu g/ml puromycin aminonucleoside for 24 h significantly attenuated the effects induced by the various amino acids by similar to 70%. The data indicate the existence of different amino acid transporter systems in podocytes. Alteration of amino acid transport may participate in podocyte injury and disturbed foot process formation.