Hypertensive Mechanisms of T-Lymphocytes in the Kidney

免疫细胞向肾脏的渗透在高血压和肾脏疾病的发展中起重要作用。 在人类和动物身上。来自PPG的初步和公布的数据表明，增加 Dahl盐敏感型(SS)大鼠摄入钠可导致免疫细胞渗入和氧分压升高 肾髓质中的H_2O_2伴随着高血压和肾损害的发生。其他 研究表明，重组激活基因1(Rag1)的基因突变或慢性 SS大鼠免疫抑制治疗可减少免疫细胞浸润，减轻盐敏感性 高血压和肾脏疾病。此外，渗入的免疫细胞富含NADPH氧化酶，并可以 因此可作为活性氧物种的来源。支持免疫系统在人类中的作用 高血压，基因组广泛关联研究表明，Sh2b3基因突变在高血压中起重要作用 T淋巴细胞信号转导与高血压和肾脏疾病有关。Sh2b3是一种已知的 T淋巴细胞和血管内皮细胞中的细胞内信号分子，但其作用机制 血压和肾脏疾病的改变是未知的。有趣的初步数据表明，基因 SS大鼠Sh2b3基因突变改变肾脏T细胞浸润，改变炎性细胞因子谱 并能减轻高盐喂养SS大鼠的高血压和肾脏损害。根据我们的初步调查 数据，我们认为肾脏中渗透的免疫细胞，特别是T淋巴细胞，发挥着有害的作用 通过在肾脏中释放过氧化氢和细胞因子来加速正在进行的疾病进程。这个 在这项提案中，将使用综合的方法来探索渗透T细胞的作用机制 在新产生的大鼠模型中，Rag1(SSRag1空)、Sh2b3(SSSh2b3突变体)和p67Phox亚单位 NADPH氧化酶(SSP67缺失)在SS大鼠体内发生了突变。该方案中的实验将测试 T细胞在肾脏的渗透会加重盐敏感型高血压和肾脏的普遍假说 通过增加自由基和细胞因子而导致的疾病。作为这一假设的推论，我们建议阐明 Sh2b3在盐敏感性高血压中的作用机制。这一假设将在三年内得到检验， 机械的、具体的目标。目标1将使用SSP67缺失和SSRag1缺失的大鼠来检验假设 浸润性免疫细胞中的NADPH氧化酶增加H_2O_2，从而放大SS高血压和肾脏 损伤和钝性压力性钠尿。目的2将使用SSRag1缺失大鼠来检验T淋巴细胞的假设 肾脏的渗透改变了细胞因子的环境，并足以放大SS的发育 高血压和肾脏损伤。目的3将研究SSSh2b3突变大鼠以检验Sh2b3的假设 通过改变T细胞在肾脏中的渗透和细胞因子/自由基的释放来调节其作用。这三个人 综合目标将通过细胞和分子的综合方法来解决 利用独特的动物模型研究整体动物生理学和病理生理学的机制。每个机械师 AIM得到了初步数据的有力支持。

Infiltration of immune cells into the kidney is important in the development of hypertension and kidney disease in humans and animals. Preliminary and published data from this PPG have demonstrated that increasing the sodium intake to Dahl Salt-Sensitive (SS) rats results in the infiltration of immune cells and elevation of O2 and H2O2 in the renal medulla which accompany the development of hypertension and kidney damage. Other studies demonstrated that genetic mutation of recombination activating gene 1 (Rag1) or chronic immunosuppressive therapy in SS rats decreased immune cell infiltration and attenuated salt-sensitive hypertensive and renal disease. Furthermore, infiltrating immune cells are enriched in NADPH oxidase and can therefore serve as a source of reactive oxygen species. Supporting a role of the immune system in human hypertension, Genome Wide Association Studies demonstrated that mutations in Sh2b3, a gene important in T-lymphocyte signaling, are associated with hypertension and kidney disease in patients. Sh2b3 is a known intracellular signaling molecule in T-lymphocytes and endothelial cells, but the mechanisms of its effects to alter blood pressure and renal disease are unknown. Intriguing preliminary data demonstrate that genetic mutation of Sh2b3 in the SS rat alters renal T-cell infiltration, changes the inflammatory cytokine profile in the kidney, and attenuates hypertension and renal damage in SS rats fed high salt. Based upon our preliminary data, we propose that the infiltrating immune cells in the kidney, specifically T-lymphocytes, exert deleterious actions by releasing H2O2 and cytokines in the kidney to accelerate the ongoing disease process. The mechanisms of action of infiltrating T-cells will be explored in this proposal using a comprehensive approach with newly generated rat models in which Rag1 (SSRag1 null), Sh2b3 (SSSh2b3 mutant), and the p67phox subunit of NADPH oxidase (SSp67 null) have been mutated in the SS rat. Experiments in this proposal will test the general hypothesis that infiltration of T-cells in the kidney exaggerates salt-sensitive hypertension and renal disease by increasing free radicals and cytokines. As a corollary to this hypothesis, we propose to elucidate the mechanisms of action of Sh2b3 in salt-sensitive hypertension. This hypothesis will be tested in three, mechanistically-based, Specific Aims. Aim 1 will use SSp67 null and SSRag1 null rats to test the hypothesis that NADPH oxidase in the infiltrating immune cells increases H2O2 which amplifies SS hypertension and renal injury and blunts pressure natriuresis. Aim 2 will use SSRag1 null rats to test the hypothesis that T-lymphocyte infiltration into the kidney alters the cytokine milieu and is sufficient to amplify the development of SS hypertension and kidney damage. Aim 3 will study SSSh2b3 mutant rats to test the hypothesis that Sh2b3 mediates its actions by altering infiltration of T-cells and cytokine/free radical release in the kidney. These three integrative aims will be addressed with a comprehensive approach ranging from cellular and molecular mechanisms to whole animal physiology and pathophysiology using unique animal models. Each mechanistic aim is strongly supported by preliminary data.