A Role of GAS6/Axl Signaling in the Development of Essential Hypertension

项目摘要 高血压是脑卒中、心肌梗死、心脏病、高血压病等疾病发病率和死亡率的主要原因。 衰竭和慢性肾病在美国退伍军人中。尽管重要的是 尽管原发性高血压的发病机制尚不清楚，但血压控制仍然是一个难题。 最近，一项新的观察结果揭示了可能参与免疫反应的潜在树突状细胞（DC）。 人类高血压使用单细胞核糖核酸（RNA）测序，一个新的DC亚群具有 已经描述了正常健康受试者中Axl和Siglec-6的表面表达。他们展示 Axl + Siglec-6 + DCs（AS DCs）可以有效地驱动T细胞增殖并产生大量的 促炎细胞因子。根据先前发表的研究和初步数据，我建议， 高血压导致内皮源性生长停滞特异性6（GAS 6）的释放， Axl在DC上的表达导致炎症及其相关的终末器官损伤。在目标1中，我将测试 高血压刺激导致GAS6/Axl依赖性炎性小体活化介导 活性氧（ROS）在AS DC中的作用。为此，我将人CD14+单核细胞暴露于 GAS6或高血压内皮细胞拉伸并评估炎性小体活化、ROS产生， 以及通过流式细胞术观察高反应性异丁香酮（isoLG）-加合物的形成。我也会 通过使用2-氨基-1，2-二氢 羟基苯乙胺（2-HOBA）在人单核细胞暴露于高血压刺激期间的作用， 通过流式细胞术评估细胞因子的产生。最后，我会研究下列各区区议会的回应： 正常血压和高血压的人类受试者以无偏的方式通过细胞指数化 通过测序（CITE-seq）确定转录组和表位。我预测清除活性氧和/或异LG 在GAS6或内皮细胞拉伸暴露期间， 炎性细胞因子释放。在目标2中，我将检验Axl依赖性 DC中的信号传导促进高血压及其相关的终末器官损伤。我会用老鼠 我已经删除了树突状细胞中的Axl（Axlfl/fl和AxlCD11cCre）。我将研究Axl在DCs中的体内作用， 通过无线电遥测和流式细胞术检测高血压。接下来，我将研究Axl在 流式细胞术检测DC对炎性小体活化和T细胞增殖的影响。我预测基因 Axl的缺失将防止高血压、DC活化及其相关炎症。在目标3中，我将 检验GAS6促进DC活化、高血压及其相关炎症的假设 我将使用GAS6基因缺失的小鼠（GAS6WT/WT和GAS6-/-）。我将在体内检查 通过进行骨髓移植研究和评估DC活化， 通过流式细胞术和无线电遥测技术研究高血压的发展。我会从基因上删除GAS6 人内皮细胞并通过流式细胞术评估DC活化状态和细胞因子产生。我 预测GAS6的基因缺失将防止高血压和免疫细胞的激活。这些 这些研究将促进我们对DCs在人类高血压发展中所起作用的理解 并将为联合治疗人类心血管疾病提供新的治疗方向 州退伍军人。

PROJECT SUMMARY Hypertension is the leading cause of morbidity and mortality from stroke, myocardial infarction, heart failure, and chronic kidney disease amongst the United States Veterans. Despite the importance of blood pressure control, the pathogenesis of essential hypertension remains poorly understood. Recently, a new observation has shed light onto potential dendritic cells (DCs) that may be involved in human hypertension. Using single-cell ribonucleic acid (RNA) sequencing, a new subset of DCs has been described with surface expression of Axl and Siglec-6 in normal health subjects. They showed that Axl+ Siglec-6+ DCs (AS DCs) can potently drive T cell proliferation and produce large amounts of pro-inflammatory cytokines. Based on previously published studies and preliminary data, I propose that hypertension leads to the release of endothelial-derived growth arrest specific 6 (GAS6) that activates Axl on DCs leading to inflammation and its associated end organ damage. In Aim 1, I will test the hypothesis that hypertensive stimuli lead to GAS6/Axl-dependent inflammasome activation mediated by reactive oxygen species (ROS) in AS DCs. In this aim, I will expose human CD14+ monocytes to GAS6 or hypertensive endothelial cell stretch and assess inflammasome activation, ROS production, and the formation of the highly reactive Isolevuglandin (isoLG)-adducts by flow cytometry. I will also examine the role of isoLGs on inflammasome activation by scavenging isoLGs using 2- hydroxybenzilamine (2-HOBA) during exposure of human monocytes to hypertensive stimuli and assess cytokine production by flow cytometry. Lastly, I will examine the response of AS DCs from normotensive and hypertensive human subjects in an unbiased fashion by cellular indexing of transcriptomes and epitopes by sequencing (CITE-seq). I predict that scavenging ROS and/or isoLGs during exposure of GAS6 or endothelial cell stretch will prevent inflammasome activation and pro- inflammatory cytokine release by AS DCs. In Aim 2, I will test the hypothesis that Axl-dependent signaling in DCs promotes hypertension and its associated end-organ damage. I will use mice in which I have deleted Axl specifically in DCs (Axlfl/fl and AxlCD11cCre). I will examine the in vivo role of Axl in DCs during hypertension by radiotelemetry and flow cytometry. Next, I will investigate the deletion of Axl in DCs on inflammasome activation and T cell proliferation in vitro by flow cytometry. I predict that genetic deletion of Axl will prevent hypertension, DC activation, and its associated inflammation. In Aim 3, I will test the hypothesis that GAS6 promotes DC activation, hypertension, and its associated inflammation I will use mice that have genetic deletion for GAS6 (GAS6WT/WT and GAS6-/-). I will examine the in vivo role of GAS6 by performing bone marrow transplantation studies and assess DC activation and development of hypertension by flow cytometry and radiotelemetry. I will genetically delete GAS6 from human endothelial cells and assess DC activation status and cytokine production by flow cytometry. I predict that genetic deletion of GAS6 will prevent hypertension and activation of immune cells. These studies will advance our understanding of the role DCs play in the development of human hypertension and will provide new therapeutic directions for the treatment of human cardiovascular disease for United States Veterans.