Renal Pericytes as a Target for Angiotensin II Signaling in Hypertension

项目摘要 肾素-血管紧张素系统（RAS）在调节全身血压中起核心作用。这示 RAS靶向药物（如血管紧张素受体阻滞剂）的已证实益处， 治疗高血压、心力衰竭和肾脏疾病。RAS的作用取决于肽 血管紧张素II（angII）作用于表达G蛋白偶联的1型血管紧张素受体的细胞（人： AT 1;小鼠：AT 1a）。我们的小组一直处于揭示angII信号传导的细胞特异性作用的最前沿 在肾脏的不同细胞群中。这些研究揭示了新的角色，为昂II的行为清楚 在不同的细胞类型中驱动与高血压相关的致病机制。这表明 总之，血管紧张素II对血压的全身作用是由于血管紧张素II对多种细胞的累积作用， 体内的类型。我们的初步研究分析了最近发表的单细胞RNA测序数据集 探索肾脏内血管紧张素受体的细胞特异性表达。我们发现周细胞， 与毛细血管和肾小球相关的细胞类型，表达小鼠AT 1a受体。另外我们 通过测量来自肾脏的快速分选的周细胞的AT 1a表达证实了这一点。然而，作用 血管紧张素信号在周细胞中的作用仍有待研究。尽管有多方面的证据表明， 提示肾周细胞在调节血压和肾损伤中起中心作用，血管紧张素相关 在高血压和慢性肾病中发生病理改变的过程。该项目将测试 周细胞内血管紧张素II信号传导有助于高血压发展的总体假设 和肾损伤。该候选人已经开发出一种新的小鼠品系，其具有可诱导的周细胞特异性缺失 AT 1a受体。首先，周细胞angII信号对血压控制的贡献将是 在基线条件下和血管紧张素II高血压期间测定。接下来，血管紧张素II信号转导在细胞内的作用， 将评估周细胞对高血压背景下肾损伤的影响。这项研究将由一个 申请人在生物医学研究方面受过良好的培训，有很好的出版记录。为此进行的训练 一项提案将在俄勒冈州健康与科学大学肾脏病学和高血压科提出 在RAS信号传导细胞特异性作用领域的领导者Susan Gurley博士的主要指导下， 在肾脏。该项目还将得到另外两位共同导师的支持： 周细胞生物学和微血管血流，以及Lynne Sakai博士，血管纤维化信号专家。 职业发展活动包括小鼠显微手术培训，离体切片成像， 肾脏病理学和单细胞RNA测序数据集的生物信息学分析。该培训旨在 推出候选人领导下一代肾脏研究，并在动物生理学方面具有良好的技能 和分子生物学。这将设置候选人，以满足他的长期职业生涯煤成为一个 他是一名独立的研究者，专注于高血压和肾损伤的细胞和分子原因。

PROJECT SUMMARY The renin-angiotensin-system (RAS) plays a central role in regulating systemic blood pressure. This is illustrated by the proven benefit of RAS-targeted drugs such as angiotensin receptor blockers, which are critical to the treatment of hypertension, heart failure and kidney disease. The actions of the RAS depend on the peptide angiotensin II (ang II) acting on cells that express the G-protein coupled type 1 angiotensin receptor (human: AT1; mouse: AT1a). Our group has been at the forefront of unmasking cell-specific roles of ang II signaling within different cell populations in the kidney. These studies have revealed novel roles for ang II to act distinctly in different cell types to drive pathogenic mechanisms associated with hypertension. This suggests that the overall, systemic effect of ang II on blood pressure results from the cumulative actions of ang II on multiple cell types within the body. Our preliminary studies analyzed recently published single-cell RNA Sequencing datasets to explore the cell-specific expression of angiotensin receptors within the kidney. We find that pericytes, a mural cell type associated with capillaries and the glomerulus, express the mouse AT1a receptor. Additionally, we confirmed this by measuring AT1a expression from rapidly sorted pericytes from the kidney. However, the role of angiotensin signaling in pericytes remains under-examined. This is despite multiple lines of evidence that suggest renal pericytes play a central role in regulating blood pressure and renal injury, angiotensin-linked processes which are pathologically altered in hypertension and chronic kidney disease. This project will test the overall hypothesis that angiotensin II signaling within pericytes contributes to the development of hypertension and renal injury. This candidate has developed a novel mouse line which has inducible pericyte-specific deletion of the AT1a receptor. First, the contribution of pericyte ang II signaling to blood pressure control will be determined under baseline conditions and during ang II hypertension. Next, the effect of ang II signaling within pericytes on renal injury in the context of hypertension will be assessed. This research will be carried out by an applicant with excellent training in biomedical research with a strong publication record. The training for this proposal will occur at Oregon Health & Science University within the Division of Nephrology and Hypertension under the primary mentorship of Dr. Susan Gurley a leader in the field of cell-specific actions of RAS signaling in the kidney. This project will also be supported by two other co-mentors: Dr. Anusha Mishra, an expert on pericyte biology and microvascular blood flow, and Dr. Lynne Sakai, an expert on vascular fibrotic signaling. Career development activities include training in mouse micro-surgery, ex vivo slice imaging, assessment of renal pathology, and bioinformatic analysis of single-cell RNA sequencing datasets. This training is designed to launch the candidate to lead the next generation of kidney research with well-honed skills in animal physiology and molecular biology. This will setup the candidate to meet his long-term career coal of becoming an independent investigator focusing on the cellular and molecular causes of hypertension and renal injury.