Molecular Origins of Phenotypic Changes in the Obese Microvascular Endothelium

肥胖微血管内皮表型变化的分子起源

基本信息

批准号：
10761699
负责人：
Hunter Gage Sellers
金额：
$ 4.77万
依托单位：
AUGUSTA UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-08-19 至 2025-08-18
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10761699
关键词：
Ablation Animals Aorta Appetite Stimulants Atherosclerosis Blood Vessels Body Weight decreased Brain Breeding CDH5 gene Cardiovascular Diseases Cell physiology Chronic Complex Data Development Diabetes Mellitus Diet Disease Down-Regulation Endothelial Cells Endothelium Epigenetic Process Etiology Flow Cytometry Functional disorder Future Gene Expression Genetic Genetic Models Genomics Genotype Goals HDAC9 gene Heterogeneity Human Hyperglycemia Hyperphagia Hypertension Impairment In Vitro Infertility Inflammatory Injections Intervention Knock-out Knockout Mice Leptin Life Expectancy Link LoxP-flanked allele Maps Metabolic Metabolism Microcirculation Modeling Molecular Morbidity - disease rate Mus NADPH Oxidase 1 Non-Insulin-Dependent Diabetes Mellitus Obese Mice Obesity Organ Pattern Peptides Peripheral Phenotype Population Predisposition Role Science Shapes Signal Transduction Sorting Stroke Tamoxifen Testing Therapeutic Thinness Time Up-Regulation Vascular Diseases Vascular Endothelial Cell Vascular Endothelium Weight Gain Writing barrier to care blood-brain barrier crossing cardiovascular health cardiovascular risk factor cost effective disability endothelial dysfunction experimental study genetic approach human disease improved in vivo insight loss of function mortality mouse model novel novel strategies obese person obesogenic overexpression oxidant stress single-cell RNA sequencing therapeutic target transcriptomics vascular endothelial dysfunction

项目摘要

PROJECT SUMMARY Obesity is a major risk factor for cardiovascular diseases (CVD) such as atherosclerosis, hypertension, type 2 diabetes and stroke. Although it is well documented that EC dysfunction is present in most forms of CVD, the mechanisms by which obesity shapes the development of EC dysfunction remains poorly understood. Further complicating the understanding of EC dysfunction is the heterogeneity of ECs throughout the vasculature. Recent studies have demonstrated a large degree of divergence between EC subtypes in the macrocirculation (aorta) that can be further altered with obesogenic diets over a short period of time. Our lab and others have shown that the microvasculature is particularly susceptible to obesity induced dysfunction and is a key predictor of end-organ damage. In the microvasculature of obese mice, we have shown a striking increase in NADPH oxidase 1 (NOX1) and histone deacetylase 9 (HDAC9), two molecules that have been shown to be important contributors to endothelial dysfunction and phenotypic changes, respectively. As of the writing of this proposal, no studies have been conducted to elucidate the heterogeneity of EC in the microcirculation, not to mention the effect of obesity on these populations or whether or not NOX1 and HDAC9 are preferentially expressed in certain populations over others. To perform these experiments in a time and cost effective manner, we have developed an AAV approach to deliver AgRP, an orexigenic peptide, specifically to the brain to induce hyperphagia and obesity. This novel approach in conjunction with endothelial specific lineage tracing mice and endothelial specific HDAC9 knockout mice will facilitate testing of our central hypothesis that obesity alters EC heterogeneity in the microcirculation to favor inflammatory EC phenotypes expressing NOX1. Aim 1 will define, through an obese endothelial specific lineage tracing model, the transcriptomic and phenotypic changes underlying loss of endothelial function in the microcirculation of obese mice. Using single cell RNA sequencing of fate mapped ECs from lean and obese mice, we will elucidate the subtypes of ECs expressing NOX1 and interrogate co-expression patterns. Aim 2 will test the hypothesis that HDAC9 has a causal role in increased expression of NOX1 and microvascular endothelial dysfunction and that weight loss reverses the expression of HDAC9 and NOX1 and restores endothelial function. We will assess in vitro and in vivo, whether HDAC9 drives the expression of NOX1 and whether its deletion ameliorates endothelial dysfunction in obesity. We will also investigate the effects of weight loss on microvascular endothelial function using a novel floxed AgRP AAV that enables cessation of AgRP expression with the goal of promoting weight loss. We anticipate the findings of this proposal will reveal new mechanisms contributing to endothelial dysfunction in obesity and will provide insight into potential therapeutic targets to improve cardiovascular health.

项目概要肥胖是动脉粥样硬化、高血压、2 型心血管疾病 (CVD) 的主要危险因素糖尿病和中风。尽管有充分证据表明大多数形式的 CVD 中都存在 EC 功能障碍，但肥胖导致 EC 功能障碍的机制仍知之甚少。更远整个脉管系统中 EC 的异质性使对 EC 功能障碍的理解变得复杂。最近的研究表明，EC 亚型在大循环方面存在很大程度的差异（主动脉）可以在短时间内通过致肥饮食进一步改变。我们的实验室和其他实验室有研究表明，微血管系统特别容易受到肥胖引起的功能障碍的影响，并且是一个关键的预测因素终末器官损伤。在肥胖小鼠的微脉管系统中，我们发现 NADPH 显着增加氧化酶 1 (NOX1) 和组蛋白脱乙酰酶 9 (HDAC9)，这两个分子已被证明很重要分别导致内皮功能障碍和表型变化。截至本提案撰写之时，目前尚无研究阐明微循环中 EC 的异质性，更不用说肥胖对这些人群的影响，或者 NOX1 和 HDAC9 是否在某些人群中优先表达人口超过其他人。为了以时间和成本有效的方式进行这些实验，我们开发了一种 AAV 方法，可将 AgRP（一种促进食欲的肽）输送到大脑，以诱导食欲亢进和肥胖。这种新方法与内皮特异性谱系追踪小鼠和内皮特异性相结合 HDAC9 敲除小鼠将有助于测试我们的中心假设，即肥胖改变了 EC 异质性微循环有利于表达 NOX1 的炎症 EC 表型。目标 1 将通过肥胖定义内皮特异性谱系追踪模型，转录组和表型变化潜在的损失肥胖小鼠微循环中的内皮功能。使用命运图谱 EC 的单细胞 RNA 测序从瘦小鼠和肥胖小鼠中，我们将阐明表达 NOX1 的 EC 亚型并询问共表达模式。目标 2 将检验以下假设：HDAC9 在 NOX1 和 NOX1 表达增加中具有因果作用微血管内皮功能障碍，体重减轻逆转了 HDAC9 和 NOX1 的表达，恢复内皮功能。我们将在体外和体内评估HDAC9是否驱动NOX1的表达以及它的缺失是否可以改善肥胖症的内皮功能障碍。我们还将调查影响使用新型 floxed AgRP AAV 减轻体重对微血管内皮功能的影响 AgRP 表达的目的是促进减肥。我们预计该提案的调查结果将揭示导致肥胖症内皮功能障碍的新机制，并将提供对潜在潜力的洞察改善心血管健康的治疗目标。