Genetic Targets of Hypertension End Organ Damage

高血压终末器官损伤的遗传靶标

基本信息

批准号：
10198017
负责人：
MICHAEL R GARRETT
金额：
$ 38.75万
依托单位：
UNIVERSITY OF MISSISSIPPI MED CTR
依托单位国家：
美国
项目类别：
财政年份：
2018
资助国家：
美国
起止时间：
2018-09-06 至 2023-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10198017
关键词：
Actins Age Albumins Alleles Animal Model Animals Blood Pressure Candidate Disease Gene Cardiovascular system Cell Adhesion Cell Line Cell physiology Cells Cellular Morphology Chromosomes Chronic Chronic Kidney Failure Complex Congenic Strain Cytoskeletal Modeling Dahl Hypertensive Rats Data Development Diagnostic Dialysis procedure Exhibits Exons Fibrosis Fluorescein-5-isothiocyanate Functional disorder Gene Expression Genes Genetic Genetic Variation Genetic study Guanine Nucleotide Exchange Factors Guanosine Triphosphate Haplotypes Health Human Hypertension In Vitro Inbred SHR Rats Injury Injury to Kidney Introns Kidney Kidney Diseases Kidney Failure Kidney Transplantation Knock-out Lead Link Medical Care Costs Medical center Mississippi Modeling Mus Organ Pathway interactions Permeability Pharmaceutical Preparations Play Population Control Predisposing Factor Prevention Proteinuria Rattus Renal function Resistance Risk Risk Factors Role Signal Transduction Sodium Chloride Stress Fibers Study models Testing Therapeutic Tubular formation United States Universities Variant Vascular Diseases Work age group arteriole blood pressure regulation cell motility congenic cytokine economic impact genetic variant genetically modified cells genomic locus hemodynamics high salt diet improved in vivo kidney dysfunction knock-down new therapeutic target podocyte positional cloning promoter protein expression protein function rho salt sensitive tool transplantation therapy uptake vascular injury

项目摘要

Project Summary Chronic kidney disease (CKD) is seen in all age groups, impacts more than 30 million people, and is associated with significant medical care costs in the United States. A critical barrier exists in understanding genetic factors that predispose people to hypertensive CKD as well as a lack of therapeutics that act to delay onset and/or progression of kidney dysfunction. The Dahl salt-sensitive (SS) rat is a widely studied model of hypertension that develops kidney injury and progressive decline in kidney function. Through positional cloning, Arhgef11, a Rho guanine nucleotide exchange factor, was implicated in kidney injury exhibited by the SS rat. ARHGEF11 catalyzes the exchange of GDP for GTP, thereby activating RhoA. RhoA-GTP then plays a pivotal role in several pathways that regulate a number of cell functions, including actin cytoskeletal organization, cell adhesion, cell motility, and gene expression. The study of an SS-Arhgef11-congenic model, which substitutes the S allele with that of the SHR (reduced expression/activity), demonstrated significantly decreased proteinuria, tubulointerstitial injury/fibrosis, and improved renal hemodynamics compared to the SS rat. The study of SS rat primary proximal tubules cells demonstrated increased expression of Arhgef11, activation of Rho-ROCK, and decreased uptake of FITC-albumin compared to the SS-Arhgef11-congenic. Conversely, knockdown of Arhgef11 in cell-lines resulted in reduced RhoA activity, decreased activation of Rho-ROCK pathway and less stress fiber formation versus control upon stimulation with TGFβ1 (profibrotic cytokine). In total, the animal and in vitro studies suggest that chronic activation of RhoA pathways by ARHGEF11 could have a significant impact on kidney injury. Thus, our central hypothesis is that allelic variants in Arhgef11 exhibited by the SS rat results in chronic dysregulation of Rho pathways, changes in proximal tubule cell morphology and function, and culminates in kidney injury and decline in kidney function. The specific aims of the proposal are to: (1) investigate the role of Arhgef11 in renal injury, renal hemodynamics, and blood pressure using animal models that augment the expression or knockout Arhgef11 (SS- Arhgef11-/-); (2) study the involvement of Arhgef11 in proximal tubule cells using primary cells and genetically modified cell- lines; and (3) investigate the role of specific Arhgef11 genetic variants/haplotypes (in rat and humans) responsible for altered expression/protein function and subsequent activation of Rho-ROCK. In summary, the successful completion of the proposed project will lead to a better understanding of the role of genetics in hypertensive CKD, the influence of factors that complicate kidney disease, and potential new therapeutic targets.

项目概要慢性肾病 (CKD) 可见于所有年龄段，影响超过 3000 万人，并且与美国巨额医疗费用相关的一个关键障碍是理解上。导致人们患高血压 CKD 的遗传因素以及缺乏延缓治疗的药物 Dahl 盐敏感 (SS) 大鼠是一种广泛研究的肾功能障碍模型。高血压会导致肾损伤和肾功能进行性下降。克隆，Arhgef11，一种 Rho 鸟嘌呤核苷酸交换因子，与由 SS 大鼠 ARHGEF11 催化 GDP 与 GTP 的交换，从而激活 RhoA-GTP，然后发挥作用。在调节多种细胞功能的多种途径中发挥关键作用，包括肌动蛋白细胞骨架 SS-Arhgef11 同类模型的组织、细胞粘附、细胞运动和基因表达。用 SHR 的等位基因取代 S 等位基因（表达/活性降低），显着证明与 SS 降低相比，蛋白尿、肾小管间质损伤/纤维化和肾血流动力学改善对 SS 大鼠原代近曲小管细胞的研究表明 Arhgef11 的表达增加，与 SS-Arhgef11 同源相比，Rho-ROCK 的激活，并且 FITC-白蛋白的摄取减少。在离线细胞系中敲低 Arhgef11 会导致 RhoA 活性降低，与 TGFβ1 刺激后的对照相比，Rho-ROCK 通路和较少的应力纤维形成（促纤维化总的来说，动物和体外研究表明 RhoA 途径的慢性激活是通过 ARHGEF11 可能对肾损伤产生重大影响，因此，我们的中心假设是等位基因变异。 SS 大鼠表现出的 Arhgef11 导致 Rho 通路慢性失调，近端变化肾小管细胞的形态和功能，最终导致肾损伤和肾功能下降。该提案的具体目标是：(1) 研究 Arhgef11 在肾损伤、肾血流动力学、使用增强表达或敲除 Arhgef11 (SS- Arhgef11-/-) 的动物模型来测量血压； (2)使用原代细胞和转基因细胞研究Arhgef11在近曲小管细胞中的参与- (3) 研究特定 Arhgef11 遗传变异/单倍型的作用（在大鼠和人类中）负责改变表达/蛋白质功能以及随后激活 Rho-ROCK。拟议项目的成功完成将有助于更好地了解遗传学在高血压 CKD、肾脏疾病并发因素的影响以及潜在的新治疗方法目标。

项目成果

期刊论文数量（1）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Estimation of Nephron Number in Whole Kidney using the Acid Maceration Method.

使用酸浸渍法估计整个肾脏中的肾单位数。

DOI：
10.3791/58599
发表时间：
2019
期刊：
Journal of visualized experiments : JoVE
影响因子：
0
作者：
Peterson,SarahM;Wang,Xuexiang;Johnson,AshleyC;Coate,IanD;Garrett,MichaelR;Didion,SeanP
通讯作者：
Didion,SeanP