Regulation of H2S signaling in vascular function

项目负责人/主要研究者（最后，第一，中间）：Naik，Jay，S 内皮细胞（EC）功能受损是系统性心血管疾病的首要指标之一。EC 功能障碍损害局部器官血流调节，这是大多数人终末器官损伤的主要原因。 心血管疾病发现EC也合成一氧化碳（CO）和硫化氢 (H2S)一氧化氮（NO）的释放，使血管舒张，开启了内皮细胞的新篇章。 气体递质生物学虽然越来越多的证据支持H2S在心血管稳态中的关键作用， 在以前的研究中，不同的研究结果在对调节和重要性的认识上存在重大差距。 血管系统中的H2S信号传导。最近，我们发现了一种新的H2S信号转导调节剂， 循环的初级和三级段之间血管舒张敏感性的差异。有趣的是，我们 初步数据表明，硫化氢以内皮依赖性方式扩张小动脉（阻力）， 对大动脉没有影响的浓度。然而，大量消耗EC膜胆固醇， 动脉揭示了H2S介导的血管舒张，表明膜脂质含量和结构域调节H2S 发信号。此外，我们的初步数据显示，天然EC胆固醇含量在大动脉中高于 阻力动脉EC膜胆固醇含量的先天区域差异介导的概念 EC扩张的功能差异是全新的，我们的初步数据（图6）表明这可能是 通过ATP结合盒家族a1（Abca 1）和磷脂转移增加胆固醇流出引起 蛋白（Pltp）。重要的是，我们以前已经表明，EC膜胆固醇的变化似乎 导致疾病的功能障碍。因此，EC膜胆固醇是一个重要的，但未调查 血管功能的变化。该项目的总体目标是双重的。首先，阐明导致 我们已经观察到EC膜胆固醇含量在大的 和小动脉。第二个是确定在体外和体内的方式，这些差异在EC膜 胆固醇控制EC功能，特别是H2S诱导的扩张。因此，我们假设， 阻力动脉EC中胆固醇流出增强下游H2S信号传导 目的1：确定导致细胞膜胆固醇含量不均匀的机制， 大小动脉 目的2：确定EC中膜胆固醇调节H2S信号的机制。 完成拟议的研究将通过阐明H2S膨胀的调节来填补现有的知识空白 以确定小动脉和大动脉之间EC功能的差异。从概念上讲，该项目非常具有创新性 其重点是膜胆固醇运输作为血管舒张调节剂的新能力。这项工作 将增加我们对EC基本性质的理解，显著影响我们对EC的理解。 血压调节和局部血流控制，并可能确定药物靶点，用于治疗 多种血管疾病 OMB编号0925-0001/0002（修订版03/2020批准至02/28/2023）页码继续格式页码

Program Director/Principal Investigator (Last, First, Middle): Naik, Jay, S Impaired endothelial cell (EC) function is one of the first indicators of systemic cardiovascular disease. EC dysfunction impairs local organ blood flow regulation, a primary cause of end-organ damage in most cardiovascular diseases. The discovery that ECs also synthesize carbon monoxide (CO) and hydrogen sulfide (H2S), in addition to nitric oxide (NO), which elicits vasodilation has opened a new chapter in endothelial gasotransmitter biology. While increasing evidence supports a key role for H2S in cardiovascular homeostasis, disparate findings in previous studies leaves a significant gap in knowledge on the regulation and significance of H2S signaling in the vasculature. Recently, we identified a novel regulator of H2S signaling that leads to profound differences in vasodilatory sensitivity between primary and tertiary segments of the circulation. Intriguingly, our preliminary data show that H2S dilates small (resistance) arteries in an endothelium-dependent manner at concentrations that have no effect in large arteries. However, depleting EC membrane cholesterol in large arteries unmasks H2S-mediated vasodilation, suggesting membrane lipid content and domains regulate H2S signaling. Moreover, our preliminary data show that native EC cholesterol content is greater in large arteries than resistance arteries. The concept that innate regional differences in EC membrane cholesterol content mediate functional differences in EC dilation is wholly novel, and our preliminary data (Fig. 6) demonstrate this may be caused by increased cholesterol efflux via ATP-binding cassette family a1 (Abca1) and phospholipid transfer protein (Pltp). Importantly, we have previously shown that changes in EC membrane cholesterol appear to contribute to dysfunction in disease. Therefore, EC membrane cholesterol is an important but uninvestigated variable in vascular function. The overall goal of this project is two-fold. First, to elucidate mechanisms leading to the functionally significant differences we have observed in EC membrane cholesterol content between large and small arteries. The second is to define ways in vitro and in vivo that these differences in EC membrane cholesterol control EC function, specifically H2S-induced dilation. Thus, we hypothesize that augmented cholesterol efflux in EC of resistance arteries enhances downstream H2S signaling Aim 1: Determine the mechanism(s) leading to heterogeneous membrane cholesterol content between large and small arteries. Aim 2: Determine the mechanism(s) by which membrane cholesterol regulates H2S signaling in EC. Completing the proposed studies will fill an existing knowledge gap by elucidating the regulation of H2S dilation to identify differences in EC function between small and large arteries. Conceptually, the project is very innovative in its focus on the novel ability of membrane cholesterol trafficking to act as a regulator of vasodilation. This work will increase our understanding of the fundamental properties of EC, significantly impacting our understanding of blood pressure regulation and local blood flow control, and may identify drug targets for the treatment of multiple vascular-driven diseases. OMB No. 0925-0001/0002 (Rev. 03/2020 Approved Through 02/28/2023) Page Continuation Format Page