Hypertensive Mechanisms of T-Lymphocytes in the Kidney

免疫细胞向肾脏的浸润在高血压和肾脏疾病的发展中是重要的 在人类和动物中。该PPG的初步和已发表数据表明， Dahl盐敏感（SS）大鼠的钠摄入导致免疫细胞浸润和O2升高， H2 O2在肾髓质中的存在，伴随着高血压和肾损害的发展。其他 研究表明，重组激活基因1（Rag 1）或慢性 免疫抑制治疗可减少SS大鼠的免疫细胞浸润和减弱盐敏感性 高血压和肾病。此外，浸润的免疫细胞富含NADPH氧化酶， 因此用作活性氧物质的来源。支持免疫系统在人类中的作用 高血压，全基因组关联研究表明，Sh 2b 3基因突变，一个重要的基因， T淋巴细胞信号传导与患者的高血压和肾脏疾病有关。Sh 2B 3是一种已知的 细胞内信号分子的T淋巴细胞和内皮细胞，但其作用机制， 改变血压和肾脏疾病是未知的。有趣的初步数据表明， 在SS大鼠中Sh 2b 3突变改变了肾T细胞浸润，改变了炎症细胞因子的分布， 肾，并减轻高盐喂养的SS大鼠的高血压和肾损伤。根据我们初步的 根据这些数据，我们认为肾脏中浸润的免疫细胞，特别是T淋巴细胞， 通过在肾脏中释放H2 O2和细胞因子来加速正在进行的疾病过程。的 本提案将采用综合方法探讨浸润性T细胞的作用机制 新产生的大鼠模型中，Rag 1（SSRag 1无效），Sh 2b 3（SSSh 2b 3突变体）和p67 phox亚基 的NADPH氧化酶（SSp 67 null）已经在SS大鼠中突变。本提案中的实验将测试 肾脏中T细胞浸润加重盐敏感性高血压和肾性高血压的一般假设 通过增加自由基和细胞因子而引起疾病。作为这一假设的推论，我们建议阐明 Sh 2b 3在盐敏感性高血压中的作用机制。这一假设将在三个方面得到检验， 以机械为基础，具体目标。目的1将使用SSp 67无效和SSRag 1无效大鼠来检验以下假设： 浸润性免疫细胞中的NADPH氧化酶增加H2 O2，这放大了SS高血压和肾性高血压。 损伤和钝性压力尿钠排泄。目的2：利用SSRag 1基因敲除大鼠来验证T淋巴细胞 浸润到肾脏改变了细胞因子环境，足以放大SS的发展 高血压和肾损伤。目的3：研究SSSh 2b 3突变大鼠，以验证Sh 2b 3基因突变的假说。 通过改变肾脏中T细胞的浸润和细胞因子/自由基的释放来介导其作用。这三 综合目标将通过从细胞和分子的全面方法来解决， 使用独特的动物模型研究整个动物生理学和病理生理学的机制。每个机械 初步数据有力地支持了这一目标。

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.