Endothelial Inflammasomes in Coronary Microcirculation -Beyond Inflammation

描述（由申请人提供）：尽管炎症在包括动脉粥样硬化在内的心血管疾病中发挥着公认的作用，但这种作用可能不是动脉粥样硬化发生的起始或必要机制，因为目前的临床实践中，如果仅使用抗炎治疗策略来治疗和预防动脉粥样硬化等心血管疾病，则不成功或效率低。内皮功能障碍是包括动脉粥样硬化在内的许多心血管疾病的早期阶段。然而，在炎症之前或炎症期间，内皮功能障碍的机制尚不清楚。最近的研究表明，Nlrp3炎症小体是细胞内开启炎症反应的主要分子机制。有趣的是，我们的初步研究表明，内皮细胞中Nlrp3炎症小体的形成和激活是对危险因素的反应，包括胆固醇晶体和visfatin（一种有害的脂肪因子），并且一些有趣的早期直接影响也被证明是由Nlrp3炎症小体激活诱导的，如内皮依赖性血管舒张受损，血管通透性增强或细胞浸润。内皮祖细胞的致病性归巢或分化。这可能代表了炎症小体激活的一种新的致病机制。因此，我们假设除了炎症之外，内源性危险信号激活内皮炎性小体直接导致冠状动脉内皮功能障碍和血管损伤。为了验证这一假设，我们提出了3个具体目标。目的1将利用Nlrp3-/-和Nlrp3+/+小鼠的冠状动脉内皮细胞（CAECs），确定Nlrp3炎症小体是否在胆固醇晶体和visfatin等危险因素的反应中形成和激活，以及除了炎症反应外，激活的Nlrp3炎症小体还会诱导哪些非炎症作用。目的2将利用Nlrp3-/-小鼠及其野生型幼崽，确定激活的内皮Nlrp3炎症小体是否在体内独立于炎症的情况下导致冠状动脉内皮功能障碍和血管损伤。Aim 3将通过caec和Nlrp3-/-小鼠及其幼崽的原代培养，探索内皮Nlrp3炎症小体如何被激活以产生炎症之外的冠状动脉损伤作用，以及炎症小体激活途径主要产生非炎症作用。本研究将首次探索炎症小体在冠状动脉内皮功能障碍和血管损伤中的非炎症作用，并确定caec对内源性危险信号（如血浆胆固醇、细胞因子或脂肪因子升高）反应的早期启动机制，这将为内皮功能障碍和微血管损伤相关血管疾病的发病机制提供新的见解。

DESCRIPTION (provided by applicant): Despite the recognized role of inflammation in cardiovascular diseases including atherosclerosis, this role may not be an initiating or essential mechanism in atherogenesis because current clinical practice is unsuccessful or has low efficiency if only using anti-inflammatory therapeutic strategy in treatment and prevention of cardiovascular diseases such as atherosclerosis. Endothelial dysfunction is the very early stage of many cardiovascular diseases including atherosclerosis. However, it remains unknown what mechanism can initiate endothelial dysfunction at early stages prior to or during inflammation. Recent studies have shown that Nlrp3 inflammasomes is a major intracellular molecular machinery to switch on the inflammatory response. Interestingly, our preliminary studies demonstrated that the formation and activation of Nlrp3 inflammasomes in endothelial cells were observed in response to danger factors including cholesterol crystal and visfatin (an injurious adipokine) and that some interesting early direct effects beyond inflammation were also shown to be induced by Nlrp3 inflammasome activation such as impaired endothelium-dependent vasodilation, enhanced vascular permeability or cell infiltration, and pathogenic homing or differentiation of endothelial progenitor cells. This may represent a novel pathogenic mechanism of inflammasome activation beyond inflammation. Thus, we hypothesize that beyond inflammation, activation of endothelial inflammasomes by endogenous danger signals directly induces endothelial dysfunction and vascular injury in coronary arteries. To test this hypothesis, we proposed 3 specific aims. Aim 1 will determine whether Nlrp3 inflammasomes are formed and activated in response to danger factors such as cholesterol crystal and visfatin and which non-inflammatory effects are induced by activated Nlrp3 inflammasomes in addition to inflammatory response using coronary arterial ECs (CAECs) from Nlrp3-/- and Nlrp3+/+ mice. Aim 2 will determine whether activated endothelial Nlrp3 inflammasomes contribute to coronary endothelial dysfunction and vascular injury in vivo independent of inflammation using Nlrp3-/- mice and their wild type littermates. Aim 3 will explore how endothelial Nlrp3 inflammasomes are activated to produce coronary vascular injurious actions beyond inflammation and which inflammasome-activating pathway mainly produces the non-inflammatory effects using primary culture of CAECs and Nlrp3-/- mice and their littermates. The findings from this grant proposal will for the first time explore the non-inflammatory role of inflammasome in coronary endothelial dysfunction and vascular injury and define the early, initiating mechanisms mediating the response of CAECs to endogenous danger signals such as increased plasma cholesterol, cytokine or adipokines, which will provide new insights into the pathogenesis of vascular disease associated with endothelial dysfunction and microvascular injury.