Redox signaling in vascular calcification - Dual role of NOX proteins

心血管（CV）钙化定义为心脏瓣膜和动脉内的病理性钙化矿物沉积，已成为心血管发病率和死亡率的预测因子和促成因素。然而，加速钙化的分子机制知之甚少。有证据表明，冠状动脉钙化，特别是微钙化，会降低斑块的完整性，并引发破裂和随后的急性心肌梗死，这是一个全球性的健康威胁和社会经济负担。最近，我们发现血管平滑肌细胞释放的钙化细胞外囊泡是形成微钙化的最小病灶。在分子水平上，我们发现，翻译后修饰的溶酶体分选受体分拣蛋白，调节这些细胞外囊泡的钙化倾向。通过更好地了解钙化细胞外囊泡的生物起源和下游功能后果，我们将获得新的见解血管钙化的发病机制。本研究提案的科学目的是检查促进血管钙化病灶的细胞和分子机制和机制，并基于特定细胞外囊泡对血管钙化的启动做出重要贡献的假设。我们的目标是了解（I）功能性调节钙化倾向生物分子进入细胞外囊泡的独特货物装载的特定分子机制，以及（II）这些钙化倾向细胞外囊泡对细胞间通讯的后果。容易将生物分子转化为EV，从而通过巨噬细胞活化加速血管钙化。我们的目的是研究A）NOX介导的氧化还原信号在血管钙化进展中的作用和细胞外囊泡的钙化潜力，以及B）细胞器重排特别是内质网-线粒体界面的贡献。此外，我们的目的是检查C）钙化细胞外囊泡对动脉粥样硬化斑块内细胞间通讯的影响。我们将利用已建立的体外和体内钙化模型，结合功能丧失和获得实验以及分子成像和高分辨率显微镜。这项研究计划可能会利用产生新的治疗和诊断策略，以控制病理生理钙化反应，这是高度未满足的临床需求，特别是在慢性肾脏病患者的高危人群。

Cardiovascular (CV) calcification, which is defined as pathological calcific mineral deposition within heart valves and arteries, has emerged as a predictor of and contributor to cardiovascular morbidity and mortality. However, the molecular mechanisms for the accelerated calcification are poorly understood. Evidence suggests that coronary artery calcification, particularly when present as microcalcification, reduces plaque integrity and triggers rupture and subsequent acute myocardial infarction, a global health threat and socio-economic burden. Recently, we made the novel observation that calcifying extracellular vesicles released by vascular smooth muscle cells are the smallest nidus to form microcalcification. On a molecular level, we showed that post-translational modification of the lysosomal sorting receptor sortilin, regulates the calcification propensity of these extracellular vesicles. By better understanding the biogenesis and downstream functional consequences of calcifying extracellular vesicles we will gain novel insights into the pathogenesis of vascular calcification. The scientific purpose of this research proposal is to examine the cellular and molecular mechanism and machinery that facilitates the nidus for vascular calcification and is based on the hypothesis that specific extracellular vesicles make essential contributions to the initiation of vascular calcification. We aim to understand (I) the specific molecular machinery that functionally regulates the unique cargo loading of calcification-prone biomolecules into extracellular vesicles and (II) the consequence of these calcification-prone extracellular vesicles on intercellular communication.We hypothesize that changes in redox signaling alter organelle rearrangements causing favored loading of calcification-prone biomolecules into EVs thus accelerating vascular calcification via macrophage activation. We aim to investigate A) the role of NOX-mediated redox signaling in the progression of vascular calcification and the calcification potential of extracellular vesicles, and B) the contribution of organelle rearrangement in particular endoplasmic reticulum-mitochondria interface. Furthermore, we aim to examine C) the impact of calcifying extracellular vesicles on intercellular communication within the atherosclerotic plaque. We will utilize established in vitro and in vivo calcification models in combination with loss-of and gain-of function experiments as well as molecular imaging and high resolution microscopy. This research program might exploit to generate novel therapeutic and diagnostic strategies to control pathophysiological calcific response that is of high unmet clinical need especially in the high-risk population of chronic kidney disease patients.