RENAL PROTECTION BY DOCOSAHEXAENOIC ACID

急性肾功能衰竭每年夺走2.5万人的生命。本项目探讨了二十二碳六烯酸(DHA)在治疗缺血性急性肾功能衰竭中的应用。DHA是一种22碳的欧米伽-3脂肪酸，具有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/再灌注损伤造成的损伤。所有对照组动物在夹闭双侧肾动脉30分钟后72小时死于急性肾功能衰竭，但只有15%的DHA组动物死亡。第二，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，导致缺血后的肾脏损伤。此外，我们还发现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。这包括激活调节炎症的内皮黏附分子、细胞因子和趋化因子以及诱导型一氧化氮合酶的基因。在这项提案中，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来抑制不良适应应激反应的假设。我们将确定DHA是否抑制对缺血的炎症反应，以及DHA是否抑制肾小管细胞对缺血应激的不良适应反应。后者包括iNOS的激活。我们将验证DHA通过抑制IRF-1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基因敲除小鼠和加/加对照小鼠对肾缺血的易感性。我们还将使用IRF-1反义治疗来治疗缺血性急性肾功能衰竭。其他人已经开发出针对IRF-1的硫代反义寡核苷酸，肾脏凭借近端小管吸收反义寡核苷酸等多阴离子的倾向，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.