Neutrophils play a pivotal role in vascular aging

摘要 动脉僵硬是血管老化的标志，与心血管疾病事件增加有关， 血管性痴呆炎症损伤和细胞外基质重塑已被认为是主要的 血管损伤和动脉僵硬的病理原因。然而，启动的分子机制 并在大血管中传播与衰老相关的病理变化仍不清楚。在此，我们建议 研究嗜中性粒细胞弹性蛋白酶（NE）（一种嗜中性粒细胞特异性蛋白酶）在引发血管渗漏中的作用， 炎症和纤维化。中性粒细胞是最丰富的 白细胞寿命短，在引发组织损伤和炎症中起关键作用。我们的数据 证实（1）脉搏波速度（PWV），动脉僵硬度的主要参数， NE敲除（NEKO）小鼠与其野生型同窝出生小鼠相比，以及（2）NEKO小鼠对 与年龄相关的炎症、纤维化和主动脉钙化。我们还观察到NE具有强有力的作用， 增加血管内皮通透性和增强主动脉平滑肌细胞纤维化， 成骨表型转换此外，NE调节中性粒细胞促炎表型通过降解 寿命调节剂Sirtuin 1（Sirt1）。根据我们的初步数据，我们假设促炎症反应 中性粒细胞与血管相互作用，通过释放NE引起血管损伤和重塑。 后者导致血管通透性增加、血液中的纤维化重塑和钙化 船舶.因此，抑制NE可能导致对衰老相关的血管损伤、纤维化重塑、 钙化和随后的动脉僵硬。本RO1提案的目的是探索中性粒细胞 和NE调节动脉壁的炎症重塑在衰老过程中有或没有喂养的 容易引起肥胖的饮食我们将探讨NE是否通过激活蛋白酶激活的 受体2（PAR2）和上皮钠通道（ENaC）信号通路， 血管平滑肌细胞的体外和体内研究。此外，我们将研究NE-Sirt1的作用 信号通路在调节中性粒细胞表型和衰老相关的血管损伤和重塑中的作用 小鼠最后，我们将评估选择性NE抑制剂对衰老相关动脉粥样硬化的潜在治疗作用。 小鼠的僵硬。该项目的成功完成将为血管老化提供一种新的治疗策略 和相关疾病。

Abstract Arterial stiffness is a hallmark of vascular aging and is related to increased cardiovascular disease events and vascular dementias. Inflammatory damage and extracellular matrix remodeling have been proposed as the major pathological causes of vascular injury and arterial stiffness. However, the molecular mechanisms that initiate and propagate aging-related pathological changes in large blood vessels remain unclear. Here, we propose to study the role of neutrophil elastase (NE), a neutrophil-specific protease, in initiating vascular leakage, inflammation and fibrosis in aged mice both with and without obesity. Neutrophils are the most abundant leukocytes, have a short lifespan, and play a critical role in initiating tissue damage and inflammation. Our data demonstrated (1) that pulse wave velocity (PWV), the primary parameter of arterial stiffness, was decreased in NE knockout (NEKO) mice compared to their wild-type littermates, and (2) that NEKO mice were resistant to aging-related inflammation, fibrosis and calcification in the aorta. We also observed that NE has potent effects on increasing vascular endothelial permeability and enhancing aortic smooth muscle cell fibrogenic and osteogenic phenotypic switch. Further, NE regulates neutrophil proinflammatory phenotype by degrading longevity regulator Sirtuin 1 (Sirt1). Based on our preliminary data, we hypothesize that pro-inflammatory neutrophils interact with blood vessels, causing vascular damage and remodeling through the release of NE. The latter contributes to the increased vascular permeability, fibrotic remodeling and calcification in the blood vessels. Thus, inhibiting NE may lead to protective effects on aging-related vascular damage, fibrotic remodeling, calcification, and subsequent arterial stiffness. The objective of this RO1 proposal is to explore how neutrophils and NE regulate inflammatory remodeling in the arterial wall during the aging process with or without feeding of an obesogenic diet. We will explore whether NE contributes to vascular aging by activating protease-activated receptor 2 (PAR2) and epithelium sodium channel (ENaC) signaling pathways in vascular endothelial cells and vascular smooth muscle cells with both in vitro and in vivo studies. Also, we will examine the role of the NE–Sirt1 signaling pathway in the regulation of neutrophil phenotype and aging-related vascular injury and remodeling in mice. Finally, we will evaluate potential therapeutic effects of a selective NE inhibitor on aging-related arterial stiffness in mice. Successful completion of this project will provide a novel therapeutic strategy for vascular aging and related diseases.