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率和死亡率的主要原因，也是心肌梗死、卒中、心力衰竭和慢性肾脏疾病的关键因素。仅在美国，高血压的患病率就达到了成年人的30%。在过去的几十年里，我们已经提出了证据，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性疾病，特别是由产生IL 17的T细胞介导的。此外，许多研究将饮食中的盐摄入量与高血压联系起来。在初步研究中，我们和其他人已经表明，过量的盐促进产生IL 17 A的CD 4+（Th 17）和CD 8+（Tc 17）细胞的分化。作为对盐的反应，这些细胞上调了对盐敏感的转录因子TonEBP（NFAT 5）及其下游靶点之一盐敏感激酶1（SGK 1）。SGK 1在调节T细胞功能中的潜在重要性是有趣的，因为它直接将盐与炎症联系起来。然而，盐影响高血压进展的机制尚不清楚。此外，T细胞的一个子集具有电压门控钠通道。我们有初步的数据表明，当这些细胞暴露于Th 17极化细胞因子和盐时，Na+通道SCN 5A在CD 4+和CD 8 + T细胞中上调。因此，我推测SGK 1是必不可少的T细胞介导的高血压的能力，通过调节SCN 5A;并增加所产生的Th 17/Tc 17细胞的致病性。为了验证这个假设，我首先计划 通过基因删除小鼠所有T细胞中的SGK 1，确定T细胞SGK 1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。为了做到这一点，我们已经产生了一个集落的小鼠是CD 4cre/SGK 1fl/fl。我们将使用这些小鼠，以确定是否损失SGK 1在T细胞的结果降低血压，增加肾/血管功能和减少肾/血管炎症相比，对照组小鼠暴露于高血压刺激。接下来我将确定SCN 5A是否受SGK监管。为此，我将对野生型小鼠（C57 BL/6 J）或CD 4cre/SGK 1fl/fl小鼠的极化T细胞进行脉冲追踪分析、RT-PCR和磷酸流。最后，我将确定是否SCN 5A活性所需的Th 17/Tc 17细胞的致病性。我将用siRNA敲除SCN 5A，并在用盐和Th 17细胞因子极化细胞后通过RT-PCR测量IL 17 A的量。我还将比较高血压和血压正常的小鼠和人类的T细胞的全细胞膜片钳测量的钠电流。此外，我将量化膜电位和钠进入T细胞的量，这些T细胞已经被Th 17细胞因子极化，然后用过量的盐休克。这些研究的完成将理想地导致确定新的治疗靶点来治疗高血压。