The Renin-Angiotensin System in Air Pollution-Mediated Exacerbation of Obesity

项目摘要：空气污染介导的肥胖加重中的肾素-血管紧张素系统。 意义除了其在肺和心血管系统中的有害影响外，最近的几种 研究表明，环境空气污染暴露与以下相关途径的启动有关： 心血管疾病（CVD）的进展，包括代谢紊乱和肥胖，其发生率为 目前在全球范围内增加。虽然介导空气污染影响代谢的途径 综合征和肥胖还没有完全了解，一些研究表明，在CVD和肥胖中， 在肾脏和局部脂肪细胞中，肾素-血管紧张素系统（RAS）高度上调， 与代谢和内分泌功能改变有关。阐明系统和组织水平的作用 脂肪细胞功能中的RAS信号传导可能为未来的研究提供新的途径、生物标志物和/或靶点。 此外，还可以在污染暴露情况下识别易受影响的个人。 创新我们将分析RAS在肾脏、脂肪和肾脏中的系统和组织水平调节， 确定吸入暴露于交通产生的空气污染物是否会导致放松管制 RAS信号传导和随后的脂肪结构和代谢/内分泌功能的改变，包括 脂肪细胞和代谢激素。重要的是，我们将在来自以下组织的组织中进行这些分析： C57 B16小鼠，使用环境相关暴露浓度，并在高脂和低脂饮食下 条件，以及脂肪细胞培养，在努力模拟暴露的情况下， 病理生理状态与人类相似。我们将使用miRNA筛选和多重 测定作为揭示肥胖症中涉及的代谢/内分泌途径的改变的方法，以及 免疫荧光和qPCR以确认细胞特异性组织表达和细胞培养物提取物终点。 具体目标。我们的初步数据显示，暴露于混合汽油和柴油发动机排放物（MVE） 导致脂肪细胞肥大，全身血管紧张素II（Ang II）升高， 高脂饮食的C57 B16小鼠中血管紧张素II 1型（AT 1）受体的表达。识别特定环境- 基因相互作用和信号通路，我们建议调查假设吸入暴露于 MVE导致小鼠肾脏和脂肪细胞中RAS信号传导增加，与起始和/或代谢相关。 参与代谢综合征、肥胖和CVD进展的途径的恶化。在目标1中， 确定吸入暴露于MVE（200 μg PM/m3）是否会导致RAS表达改变，miRNA 调节和脂肪细胞结构和/或信号传导（脂联素、脂肪因子等）在C57 B16小鼠中， vs.低脂饮食。在目的2中，我们将阐明MVE诱导的循环血管紧张素II在介导血管紧张素受体的改变中的作用。 脂肪细胞功能和信号传导，通过ACE抑制剂治疗同时暴露（体内），以及 用来自我们研究动物的血浆处理的脂肪细胞培养物中局部RAS的shRNA敲低（体外）。

Project Abstract: The Renin-Angiotensin System in Air Pollution-Mediated Exacerbation of Obesity. Significance. In addition to its harmful effects in the pulmonary and cardiovascular systems, several recent studies have implicated environmental air pollution exposure in initiation of pathways associated with progression of cardiovascular disease (CVD), including metabolic disorder and obesity, rates of which are currently increasing worldwide. While the pathways that mediate the effects of air pollution in metabolic syndrome and obesity are not fully understood, several studies have shown that in both CVD and obesity the renin-angiotensin system (RAS) is highly upregulated both in the kidney and locally in adipocytes, which is associated with altered metabolic and endocrine function. Elucidating the role of systemic and tissue level RAS signaling in adipocyte function may provide novel pathways, biomarkers, and/or targets for future therapies and also allow for identification of susceptible individuals in pollution-exposure scenarios. Innovation. We will analyze systemic and tissue level regulation of the RAS in kidney, adipose, and vasculature to determine whether inhalation exposure to traffic-generated air pollutants results in deregulation of RAS signaling and subsequent alterations in adipose structure and metabolic/endocrine function, including adipocytes and metabolic hormones. Importantly, we will conduct these analyses in tissues derived from C57Bl6 mice, using environmentally relevant exposure concentrations, and under both high and low fat diet conditions, as well as adipocyte cell culture, in an effort simulate exposure scenarios and underlying pathophysiologic states similar to that in the human population. We will use miRNA screening and Multiplex assays as an approach to reveal alterations in metabolic/endocrine pathways involved in obesity, as well as immunofluorescence and qPCR to confirm cell-specific tissue expression and cell culture extract endpoints. Specific Aims. Our preliminary data show exposure to mixed gasoline and diesel engine emissions (MVE) results in adipocyte hypertrophy, elevated systemic angiotensin II (Ang II), and increased renal and adipose expression of Ang II type 1 (AT1) receptor in C57Bl6 mice on a high fat diet. To identify specific environment- gene interactions and signaling pathways, we propose to investigate the hypothesis inhalational exposure to MVE results in increased RAS signaling in the kidneys and adipocytes of mice, associated with initiation and/or exacerbation of pathways involved in metabolic syndrome, obesity, and progression of CVD. In Aim 1 we will determine whether inhalation exposure to MVE (200 μg PM/m3) results in altered RAS expression, miRNA regulation, and adipocyte structure and/or signaling (adiponectin, adipokines, etc.) in C57Bl6 mice on a high vs. low fat diet. In Aim 2, we will elucidate the role of MVE-induced circulating Ang II in mediating alterations in adipocyte function and signaling, through ACE-inhibitor treatment concurrent with exposure (in vivo), and also shRNA knockdown of local RAS (in vitro) in adipocyte cell culture treated with plasma from our study animals.