RENAL PROTECTION BY DOCOSAHEXAENOIC ACID

急性肾衰竭每年夺去25000人的生命。本项目探讨使用二十二碳六烯酸（DHA）在治疗缺血性急性肾功能衰竭。DHA是一种22碳的-3脂肪酸，有6个双键。我们目前的建议是基于DHA的两个显著影响。首先，我们发现二十二碳六烯酸（DHA）在小鼠模型中可以防止缺血/再灌注损伤。所有对照动物在夹紧双肾动脉30分钟后72小时内死于急性肾衰竭，但服用dha的动物只有15%。其次，我们发现DHA在体外抑制巨噬细胞诱导型一氧化氮合酶（iNOS）基因的激活。这种酶产生大量的细胞毒性分子一氧化氮，导致缺血后肾损伤。此外，我们发现DHA通过抑制转录因子IRF-1的作用来抑制iNOS基因的激活。IRF-1被细胞应激激活并协调应激反应。这包括调节炎症的内皮粘附分子、细胞因子、趋化因子和iNOS的基因激活。在本提案中，我们将探索DHA作为急性肾功能衰竭的潜在治疗方法，并验证DHA通过抑制转录因子IRF-1抑制适应不良应激反应的假设。我们将确定DHA是否抑制缺血的炎症反应，以及DHA是否抑制肾小管细胞对缺血应激的不适应反应。后者包括iNOS的活化。我们将测试DHA通过抑制IRF-1的作用来改善缺血性急性肾功能衰竭的预测。我们将比较IRF-1敲除小鼠和正/正对照小鼠对肾缺血的易感性。我们还将采用IRF-1反义疗法治疗缺血性急性肾功能衰竭。其他人已经开发出用于IRF-1的硫代反义寡核苷酸，肾脏由于近端小管倾向于吸收多阴离子，如反义寡核苷酸，是反义治疗的理想靶点。

Acute renal failure claims 25,000 lives annually. This project explores the use of docosahexaenoic acid (DHA) in the treatment of ischemic acute renal failure. DHA is a 22 carbon, omega-3 fatty acid with 6 double bonds. Our current proposal is based on two striking effects of DHA. First, we find that docosahexaenoic acid (DHA) prevents damage from ischemia/reperfusion injury in a murine model. All of the control animals died of acute renal failure at 72 hours after clamping both renal arteries for 30 minutes, but only 15 percent of the DHA-treated animals. Second, we find that DHA inhibits activation of the gene for inducible nitric oxide synthase (iNOS) by macrophages in vitro. This enzyme produces large quantities of the cytotoxic molecule nitric oxide which contribute to renal injury after ischemia. Furthermore, we find that DHA inhibits iNOS gene activation by inhibiting the action of the transcription factor IRF-1. IRF-1 is activated by cellular stress and coordinates a stress response. This includes activation of genes for endothelial adhesion molecules which regulate inflammation, for cytokines and chemokines and iNOS. In this proposal, we will explore DHA as a potential therapy of acute renal failure and test the hypothesis that DHA inhibits the maladaptive stress response by inhibiting the transcription factor IRF-1. We will determine if DHA inhibits the inflammatory response to ischemia, and if DHA inhibits maladaptive responses of renal tubule cells to ischemic stress. The latter includes activation of iNOS. We will test the prediction that DHA ameliorates ischemic acute renal failure by inhibiting IRF-1 action. We will compare the susceptibility of IRF-1 knockout mice and plus/plus control mice to renal ischemia. We will also use IRF-1 antisense therapy to treat ischemic acute renal failure. Others have developed phosphorothioate antisense oligonucleotides for IRF-1, and the kidney, by virtue of the propensity of the proximal tubule to absorb polyanions such as antisense oligonucleotides, is an ideal target for antisense therapy.