The Effect of Salt on T Cell Function in Hypertension

盐对高血压患者 T 细胞功能的影响

• 批准号: 9138616
• 负责人: Allison Elizabeth Norlander
• 金额: $ 1.82万
• 依托单位: VANDERBILT UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-01 至 2017-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9138616
• 关键词: Address; Adult; Affect; Age-Years; Angiotensin II; Blood Vessels; CD8B1 gene; Cardiac; Cardiovascular Diseases; Cell physiology; Cells; Chronic Kidney Failure; Clinical Research; DOCA; Data; Development; Disease; Epithelial; Excess Dietary Salt; Health; Heart failure; Human; Hypertension; Hypotension; IL17 gene; IL6 gene; Immune; Immune system; Immunologic Techniques; Inflammation; Inflammatory; Inflammatory Response; Interleukin-17; Interleukins; Invaded; Kidney; Lead; Learning; Light; Link; MAPK14 gene; Measures; Mediating; Membrane Potentials; Modeling; Molecular; Morbidity - disease rate; Mus; Myocardial Infarction; Neuraxis; Organ; Pathogenesis; Pathogenicity; Phenotype; Phosphotransferases; Physiologic pulse; Physiological; Prevalence; Production; Reverse Transcriptase Polymerase Chain Reaction; Shock; Site; Small Interfering RNA; Sodium; Sodium Channel; Sodium Chloride; Stimulus; Stroke; T-Cell Activation; T-Lymphocyte; T-Lymphocyte Subsets; TNF gene; Testing; Ubiquitination; United States; Vascular Diseases; Widespread Disease; Wild Type Mouse; Work; blood pressure reduction; cytokine; dietary salt; epithelial Na+ channel; experience; interest; kidney vascular structure; knock-down; macrophage; member; monocyte; mortality; new therapeutic target; normotensive; novel therapeutics; patch clamp; polarized cell; prevent; research study; response; salt intake; skills; stem; transcription factor; ubiquitin-protein ligase; vascular inflammation; voltage

 DESCRIPTION (provided by applicant): Hypertension is a leading cause of cardiovascular disease morbidity and mortality and is a key contributor to myocardial infarction, stroke, heart failure and chronic kidney disease. The prevalence of hypertension reaches 30% of adults in the United States alone. We have put forth evidence in the past few decades suggesting that hypertension is an inflammatory disease mediated by cells of the innate and adaptive immune systems, specifically by IL17-producing T cells. In addition, many studies have linked dietary salt intake to hypertension. In preliminary studies, we and others have shown that excess salt promotes differentiation of IL17A-producing CD4+ (Th17) and CD8+ (Tc17) cells. In response to salt, these cells upregulate the osmosensitive transcription factor, TonEBP (NFAT5) and one of its downstream targets, the salt-sensing kinase 1 (SGK1). The potential importance of SGK1 in modulating T cell function is interesting as it directly connects salt to inflammation. However, th mechanism by which salt acts to affect the progression of hypertension is unknown. Additionally, a subset of T cells possesses voltage-gated sodium channels. We have preliminary data showing that the Na+ channel SCN5A is upregulated in CD4+ and CD8+ T cells when these cells are exposed to Th17 polarizing cytokines and salt. Therefore, I hypothesize that SGK1 is essential to the ability of T cells to mediate hypertension by regulating SCN5A; and increasing the pathogenicity of the resultant Th17/Tc17 cells. To test this hypothesis I first plan to determine whether T cell SGK1 is necessary for the hypertensive and inflammatory response to angiotensin II and DOCA-salt by genetically deleting SGK1 in all T cells in mice. To do this, we have generated a colony of mice that are CD4cre/SGK1fl/fl. We will use these mice to determine if loss of SGK1 in T cells results in lowered blood pressure, increased renal/vascular function and decreased renal/vascular inflammation compared to control mice when exposed to hypertensive stimuli. Next I will determine if SCN5A is regulated by SGK. To do this, I will conduct pulse chase analyses, RT-PCR and phospho-flow on polarized T cells from wild type mice (C57BL/6J) or from CD4cre/SGK1fl/fl mice. Finally, I will determine if SCN5A activity is required for Th17/Tc17 cell pathogenicity. I will knock down SCN5A with siRNA and measure the amount of IL17A by RT-PCR after the cells are polarized with salt and Th17 cytokines. I will also compare sodium currents measured by whole cell patch clamping in T cells from hypertensive and normotensive mice and humans. In addition, I will quantify the membrane potential and the amount of sodium entering T cells that have been polarized with Th17 cytokines and then shocked with excess salt. Completion of these studies will ideally lead to the identification of novel therapeutic targets to treat hypertension.

 描述（由申请人提供）：高血压是心血管疾病发病和死亡的主要原因，并且是导致心肌梗塞、中风、心力衰竭和慢性肾病的关键因素。仅在美国，高血压的患病率就达到了 30% 的成年人。我们在过去几十年中提出的证据表明，高血压是一种由先天性和适应性免疫系统细胞介导的炎症性疾病，特别是由产生 IL17 的 T 细胞介导。此外，许多研究已将膳食盐联系起来。在初步研究中，我们和其他人已经表明，过量的盐会促进产生 IL17A 的 CD4+ (Th17) 和 CD8+ (Tc17) 细胞的分化。这些细胞对盐的反应会上调渗透敏感转录因子 TonEBP (NFAT5)。及其下游靶点之一，盐敏感激酶 1 (SGK1) SGK1 在调节 T 细胞功能中的潜在重要性很有趣，因为它直接将盐与盐连接起来。然而，盐影响高血压进展的机制尚不清楚。此外，我们有初步数据显示 Na+ 通道 SCN5A 在 CD4+ 和 CD8+ T 细胞中上调。当这些细胞暴露于 Th17 极化细胞因子和盐时，我认为 SGK1 对于 T 细胞通过调节 SCN5A 介导高血压的能力至关重要；为了验证这个假设，我首先计划了 Th17/Tc17 细胞。 通过基因删除小鼠所有 T 细胞中的 SGK1 来确定 T 细胞 SGK1 是否是对血管紧张素 II 和 DOCA-盐的高血压和炎症反应所必需的。为此，我们生成了 CD4cre/SGK1fl/fl 小鼠群体。我们将使用这些小鼠来确定与对照小鼠相比，当暴露于接下来，我将确定 SCN5A 是否受 SGK 调节。为此，我将对野生型小鼠 (C57BL/6J) 或 CD4cre/SGK1fl 的极化 T 细胞进行脉冲追踪分析、RT-PCR 和磷酸化流。 /fl 小鼠。最后，我将确定 Th17/Tc17 细胞致病性是否需要 SCN5A 活性，并测量 siRNA 的数量。用盐和 Th17 细胞因子极化细胞后，通过 RT-PCR 检测 IL17A。我还将比较高血压和正常血压小鼠和人类 T 细胞中通过全细胞膜片钳测量的钠电流。进入 T 细胞的钠量已被 Th17 细胞因子极化，然后用过量的盐进行休克，理想情况下，这些研究的完成将有助于确定治疗高血压的新治疗靶点。