Chang Chiz-Tzung, Hung Cheng-Chieh, Yang Chih-Wei, Vandewalle Alain, Wu Mai-Szu
Graduate Institute of Clinical Medical Sciences, Chang Gung University, Taoyuan, Taiwan.
Transpl Int. 2005 Jul;18(7):871-8. doi: 10.1111/j.1432-2277.2005.00152.x.
Intrarenal vasoconstriction is thought to be the major pathogenesis of cyclosporine (CsA) nephrotoxicity. Nitric oxide (NO) and prostaglandin E2 (PGE2) are two of the major intrarenal vasodilators, which protect kidney from ischemia. CsA inhibited NO production in renal epithelial cells. The interaction between CsA and intrarenal PGE2 and NO production is still unclear. The aim of the study is to evaluate the interaction of CsA with intrarenal PGE2 and NO production in renal epithelial cells. Models of cultured mouse thick ascending limb (TAL) cells are chosen to perform the experiments, as TAL cells are the major site of intrarenal PGE2 production and target of CsA nephrotoxicity. We investigated the PGE2 production by enzyme-linked immunosorbent assay, and cyclooxygenase (COX-1 and COX-2) mRNA expression by RT-PCR in cultured cells treated with or without CsA. TAL cells maintained the main characteristics of their parental cells. TAL cells produce PGE2 mainly by COX-1 in steady state and by COX-2 in stimulated state by lipopolysaccharide (LPS). CsA (100 ng/ml) significantly reduced the PGE2 production up to 43% in TAL cells in LPS stimulated status (control versus CsA: 375.1 +/- 15.5 vs. 187.2 +/- 12.2 nm/mg protein, n = 7, P < 0.001). The effects were dose-dependent. The mRNA expression of COX1 is not affected and COX-2 is decreased in CsA-treated TAL cells. NO donor could prevent the inhibitory effects of CsA. We concluded that CsA decreased intrarenal PGE2 production in stimulated status mainly by decreasing COX-2 expression. NO might play a role in the CsA effect. The results suggested the role possible of PGE2 in CsA nephrotoxicity.
肾内血管收缩被认为是环孢素（CsA）肾毒性的主要发病机制。一氧化氮（NO）和前列腺素E2（PGE2）是两种主要的肾内血管舒张剂，可保护肾脏免受缺血损伤。CsA抑制肾上皮细胞中NO的产生。CsA与肾内PGE2及NO产生之间的相互作用仍不清楚。本研究的目的是评估CsA与肾内PGE2及肾上皮细胞中NO产生之间的相互作用。选用培养的小鼠髓袢升支粗段（TAL）细胞模型进行实验，因为TAL细胞是肾内PGE2产生的主要部位及CsA肾毒性的靶细胞。我们通过酶联免疫吸附测定法研究了经或未经CsA处理的培养细胞中PGE2的产生情况，并通过逆转录聚合酶链反应（RT-PCR）检测了环氧化酶（COX-1和COX-2）的mRNA表达。TAL细胞保持了其亲代细胞的主要特征。TAL细胞在稳态下主要通过COX-1产生PGE2，在脂多糖（LPS）刺激状态下则通过COX-2产生PGE2。在LPS刺激状态下，CsA（100 ng/ml）可使TAL细胞中的PGE2产生显著降低达43%（对照组与CsA组：375.1±15.5 vs. 187.2±12.2 nm/mg蛋白，n = 7，P < 0.001）。其作用呈剂量依赖性。在经CsA处理的TAL细胞中，COX1的mRNA表达未受影响，而COX-2的表达降低。NO供体可预防CsA的抑制作用。我们得出结论，CsA在刺激状态下主要通过降低COX-2表达来减少肾内PGE2的产生。NO可能在CsA的作用中发挥作用。结果提示了PGE2在CsA肾毒性中可能的作用。
