Role of Smooth Muscle-derived Vascular Progenitor Cells (AdvSca1-SM) in Vasa Vasorum Expansion and Atherosclerotic Plaque Progression

平滑肌源性血管祖细胞 (AdvSca1-SM) 在血管滋养管扩张和动脉粥样硬化斑块进展中的作用

• 批准号: 10318849
• 负责人: Allison M Dubner
• 金额: $ 3.4万
• 依托单位: UNIVERSITY OF COLORADO DENVER
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10318849
• 关键词: Role; Smooth; Muscle; derived; Vascular

PROJECT SUMMARY/ABSTRACT Atherosclerosis is a complex inflammatory disease and a major cause of morbidity and mortality worldwide, but current therapies fail to adequately meet clinical needs. Until recently, most atherosclerosis research has focused on endothelial activation, immune cell recruitment, and lipid retention within the intima, but emerging evidence implicates the vessel adventitia in the pathogenesis of atherosclerosis. Specifically, it has been suggested that expansion of adventitial microvessels, the vasa vasorum (VV), drives atherosclerosis progression by facilitating inflammatory cell infiltration to the vessel wall and developing atheroma. This project focuses on the role that smooth muscle-derived vascular progenitor cells, termed AdvSca1-SM cells, play in vasa vasorum expansion and plaque neovascularization. Our lab previously identified AdvSca1-SM cells as a subset of resident vascular progenitor cells reprogrammed from mature smooth muscle cells in situ in a Klf4 depended process. These cells are enriched for genes in the hedgehog/Wnt/β-catenin pathways, particularly Gli1, and have multilineage differentiation potential. In the setting of acute vascular injury, AdvSca1-SM cells expand robustly to contribute to fibrotic remodeling, but it is unclear what role they play in chronic injuries such as atherosclerosis. Work from several groups has suggested that adventitial progenitor cells can contribute to VV expansion, and our group has previously demonstrated that AdvSca1-SM cells are capable of de novo vessel formation via endothelial or smooth muscle cell differentiation in Matrigel plug assays. Additionally, we have identified AdvSca1-SM-like cells in the microvessels surrounding human coronary arteries, suggesting a potential role in the VV. The aim of this project is to determine the contribution of AdvSca1-SM cells to VV expansion, plaque neovascularization, and atherosclerotic progression. We hypothesize that AdvSca1-SM cells are major contributors to atherosclerosis, and that modulation of these cells could alter disease progression. Specific Aim 1 will define the functional contribution of AdvSca1-SM cells to VV expansion and/or plaque progression using a highly specific AdvSca1- SM genetic lineage tracing mouse model; AdvSca1-SM contribution will be assessed using immunofluorescent microscopy and flow cytometry. Specific Aim 2 will define the mechanisms controlling AdvSca1-SM cells in the setting of atherosclerosis, with an emphasis on the Gli/Wnt/β-catenin/Klf4 signaling axis previously identified as a regulator of AdvSca1-SM cells in the setting of acute vascular injury. We will modulate this signaling axis using AdvSca1-SM-specific Gli1 overexpression or Klf4 knockout; the effects of these modifications on AdvSca1-SM maintenance or differentiation will be assessed using immunofluorescent microscopy, flow cytometry, and single cell RNA-seq. Ultimately, the work proposed here represents a novel avenue of research that will help fill the current knowledge gap regarding the role AdvSca1-SM cells play in the atherosclerotic disease process.

项目概要/摘要 动脉粥样硬化是一种复杂的炎症性疾病，也是全世界发病和死亡的主要原因，但 目前的治疗方法无法充分满足临床需求。直到最近，大多数动脉粥样硬化研究都集中在 内皮激活、免疫细胞募集和内膜内脂质保留，但新的证据 表明血管外膜参与动脉粥样硬化的发病机制。具体来说，有人建议 外膜微血管，即血管滋养管（VV）的扩张，通过促进动脉粥样硬化的进展 炎症细胞浸润至血管壁并形成粥样斑块。该项目的重点是角色 平滑肌来源的血管祖细胞，称为 AdvSca1-SM 细胞，在血管扩张中发挥作用 和斑块新生血管形成。我们的实验室之前将 AdvSca1-SM 细胞鉴定为常驻血管的一个子集 祖细胞在 Klf4 依赖性过程中由成熟平滑肌细胞原位重编程。这些细胞 富含刺猬/Wnt/β-catenin 通路中的基因，特别是 Gli1，并且具有多谱系 差异化潜力。在急性血管损伤的情况下，AdvSca1-SM 细胞会强劲扩张，以贡献 纤维化重塑，但尚不清楚它们在动脉粥样硬化等慢性损伤中发挥什么作用。工作自 几个小组表明外膜祖细胞可以促进 VV 扩张，我们小组 先前已证明 AdvSca1-SM 细胞能够通过内皮或 基质胶塞测定中的平滑肌细胞分化。此外，我们还鉴定了 AdvSca1-SM 样细胞 存在于人类冠状动脉周围的微血管中，表明在 VV 中具有潜在作用。此举的目的 该项目旨在确定 AdvSca1-SM 细胞对 VV 扩张、斑块新生血管形成和 动脉粥样硬化进展。我们假设 AdvSca1-SM 细胞是动脉粥样硬化的主要贡献者， 这些细胞的调节可以改变疾病的进展。具体目标 1 将定义功能 使用高度特异性的 AdvSca1-SM 细胞对 VV 扩张和/或斑块进展的贡献 SM基因谱系追踪小鼠模型； AdvSca1-SM 的贡献将使用免疫荧光进行评估 显微镜和流式细胞术。具体目标 2 将定义控制 AdvSca1-SM 细胞的机制 动脉粥样硬化的背景，重点是先前确定的 Gli/Wnt/β-catenin/Klf4 信号轴 急性血管损伤时 AdvSca1-SM 细胞的调节因子。我们将使用调制该信号轴 AdvSca1-SM 特异性 Gli1 过表达或 Klf4 敲除；这些修饰对 AdvSca1-SM 的影响 将使用免疫荧光显微镜、流式细胞术和单次评估来评估维持或分化 细胞RNA测序。最终，这里提出的工作代表了一种新颖的研究途径，将有助于填补 目前关于 AdvSca1-SM 细胞在动脉粥样硬化疾病过程中的作用的知识差距。