Cyclosporine Attenuates Arginine Transport, in Human Endothelial Cells, through Modulation of Cationic Amino Acid Transporter-1
Cyclosporine Attenuates Arginine Transport, in Human Endothelial Cells, through Modulation of Cationic Amino Acid Transporter-1
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DOI：
10.1159/000350614
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发表时间：
2013-01-01
影响因子：
4.2
通讯作者：
Schwartz, Idit F.
中科院分区：
文献类型：
--
作者：
Grupper, Ayelet;Shashar, Moshe;Schwartz, Idit F.
背景：环孢素(CsA)的心血管毒性包括高血压、动脉粥样硬化加速和血栓性微血管病变，所有这些都是内皮细胞功能障碍的结果。内皮细胞功能障碍的特征是内皮型一氧化氮合酶(ENOS)活性降低。阳离子氨基酸转运蛋白-1(CAT-1)是eNOS的特异性精氨酸转运蛋白。CsA已被证明可以减少一氧化氮(NO)的产生。然而，这一机制仍然难以捉摸。我们推测CsA通过调节其选择性精氨酸供应者CAT-1来抑制eNOS的活性。方法：采用体外培养的人脐静脉内皮细胞，观察环孢素A对人脐静脉内皮细胞摄取精氨酸、NO_2/NO_3生成及CAT-1、蛋白激酶Cα和磷酸化蛋白激酶Cα蛋白表达的影响。结果：CsA(0.5~2 mU g/m l)以剂量和时间依赖的方式显著抑制细胞的精氨酸转运，与L-精氨酸(1 MM)共同孵育可阻止这种现象。伴随上述发现的是蛋白质硝化增加，这是一种衡量过氧亚硝酸盐积累的指标。相比之下，NO2/NO3的生成没有观察到任何变化。CsA显著降低CAT-1蛋白丰度，这种作用可被L-精氨酸减弱。CsA对PKCα和磷酸化PKCα(CAT-1抑制物)蛋白含量无明显影响。结论：CsA通过调节CAT-1抑制HUVEC的精氨酸转运，诱导蛋白质硝化。版权所有(C)2013年，S.Karger AG，巴塞尔
Background: The spectrum of cardiovascular toxicity by cyclosporine (CsA) includes hypertension, accelerated atherosclerosis, and thrombotic microangiopathy, all of which are the result of endothelial cell dysfunction. Endothelial cell dysfunction is characterized by decreased endothelial nitric oxide synthase (eNOS) activity. Cationic amino acid transporter-1 (CAT-1) is the specific arginine transporter for eNOS. CsA has been shown to attenuate nitric oxide (NO) generation. However, the mechanism remains elusive. We hypothesize that CsA inhibits eNOS activity through modulation of its selective arginine supplier CAT-1. Methods: We studied the effect of CsA on arginine uptake, NO2/NO3 generation, and CAT-1, protein kinase C alpha (PKC alpha), and phosphorylated PKC alpha protein expression in human umbilical vein endothelial cell cultures (HUVEC) in the absence and presence of L-arginine. Results: CsA (0.5-2 mu g/ml) significantly attenuated arginine transport in a dose- and time-dependent manner, a phenomenon which was prevented by co-incubation with L-arginine (1 mM). The aforementioned findings were accompanied by increased protein nitration, a measure for peroxynitrite accumulation. In contrast, no changes were observed in NO2/NO3 generation. CsA significantly decreased the abundance of CAT-1 protein, an effect that was attenuated by L-arginine. PKC alpha and phosphorylated PKC alpha (CAT-1 inhibitors) protein contents were not affected by CsA. Conclusion: CsA inhibits arginine transport and induces protein nitration in HUVEC through modulation of CAT-1. Copyright (c) 2013 S. Karger AG, Basel