Impact of Aging on Stem Cell Repair in Atherosclerosis

衰老对动脉粥样硬化干细胞修复的影响

• 批准号: 6935297
• 负责人: Pascal J. Goldschmidt-Clermont
• 金额: $ 31.19万
• 依托单位: DUKE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-08-15 至 2009-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6935297
• 关键词: aging; angiogenesis; animal old age; atherosclerosis; bone marrow; cardiovascular disorder prevention; cardiovascular disorder therapy; cell biology; cell population study; flow cytometry; gene expression; genetically modified animals; integrins; juvenile animal; laboratory mouse; microarray technology; nonhuman therapy evaluation; pathologic process; phenotype; regeneration; selectins; stem cell transplantation; stem cells; vascular cell adhesion molecule; vascular endothelium

DESCRIPTION (provided by applicant): Atherosclerosis represents an aberrant, continuous reparative inflammatory process in response to repeated injuries to the vessel wall. Indeed, the cardiovascular system is continuously exposed to a multitude of insults whose impact cumulates with the passage of time. Two sources of cells participating in the repair process exist: (1) local, differentiated, vascular endothelial and smooth muscle cells that migrate from adjacent vessel segments; and (2) recruited stern cells/vascular progenitor cells from the bone marrow, via peripheral circulation. We have recently discovered that chronic administration of whole bone marrow (BM) cells significantly reduced atherosclerotic lesion formation in an established mouse model of atherosclerosis --ApoE -/- C57/B6 mice fed high fat cholesterol, Western-type diet--even in the absence of restoration of ApoE gene expression and normalization of plasma cholesterol levels (>1200 mg/dl). Furthermore, BM cells from young, but not old, ApoE-/- mice were capable of vascular rejuvenation and atherosclerosis prevention. This data underscores the importance of stem cells/vascular progenitor cells in vascular healing and atherogenesis and provide support for the use of stern/progenitor cell therapy as a novel preventative and/or treatment strategy for atherosclerosis, particularly for individuals whose bone marrow, and its obsolescence, represents the bottleneck for long-term integrity of the cardiovascular system. In this project, we propose to test the hypothesis that after a lifetime of repairing atherosclerotic arteries, the supply of the specific type(s) of vascular progenitor cells (VPCs) needed to maintain the homeostasis of the cardiovascular system is somehow exhausted or these cells are functionally impaired. If the VPC "spare parts" can be outsourced, the repair process can be boosted at appropriate intervals and atherosclerotic consequences delayed, perhaps indefinitely. Specific Aim 1: To determine the quantitative composition (FACS analysis), progeny functional characteristics, and gene expression phenotype (microarray analysis) of whole bone marrow cells or lineage negative side population (lin-SP) cells obtained from young versus old (wild-type, and ApoE -/-) mice; Specific Aim 2: To establish that competent VPCs are encompassed in the lin-SP fraction in the marrow, which convey the anti-atherosclerotic efficacy, by testing the effects of unfractionated bone marrow cells, enriched linSP cells and bone marrow cells deprived of lin-SP fraction obtained from young versus old (wild-type and ApoE -/-) mice in suppressing elevated plasma levels of chemo-cytokines and growth factors and in preventing atherosclerotic lesion formation in ApoE -/- mice; Specific Aim 3: To determine within the lin-SP fraction of young apoE -/- and wild-type BM the relative efficacy of a) candidate VPCs (CVPC, cells that are either depleted or functionally impaired in aging mice) isolated using markers identified in Aim 1, b) unfractionated lin-SP cells minus CVPCs (USP-CVPC), and c) unfractionated linSP cells (USP) in suppressing elevated plasma levels of IL-6, VEGF and other inflammatory markers and in preventing atherosclerosis in ApoE -/- mice; and Specific Aim 4: To determine the role of a4-integrin, VCAM-1, and E-selectin in mediating the engraftment of vascular progenitor cells to chronically injured vessel wall in apoE-/- mice. As a corollary, the relative contribution of cell engraftment versus a non-cell autonomous mechanism to vascular repair will be characterized.

描述(由申请人提供)：动脉粥样硬化是一种异常的、持续的修复性炎症过程，以应对血管壁的反复损伤。事实上，心血管系统不断地受到各种侮辱，其影响随着时间的推移而累积。参与修复过程的细胞有两种来源：(1)从邻近血管节段迁移的局部、分化的血管内皮细胞和平滑肌细胞；(2)通过外周循环从骨髓中招募干细胞/血管前体细胞。我们最近发现，在一种已建立的动脉粥样硬化小鼠模型--喂养高脂肪胆固醇的西式饮食的ApoE-/-C57/B6小鼠中，长期给予全骨髓(BM)细胞显著减少动脉粥样硬化病变的形成--即使在ApoE基因表达和血浆胆固醇水平正常化(&gt；1200 mg/dl)的情况下也是如此。此外，来自年轻但不是老年的载脂蛋白E-/-鼠的BM细胞能够使血管恢复活力和预防动脉粥样硬化。这些数据强调了干细胞/血管前体细胞在血管愈合和动脉粥样硬化形成中的重要性，并支持使用STREN/前体细胞疗法作为动脉粥样硬化的一种新的预防和/或治疗策略，特别是对于那些骨髓及其过时是心血管系统长期完整性的瓶颈的人。在这个项目中，我们建议检验一种假设，即在修复动脉粥样硬化的一生后，维持心血管系统内稳所需的特定类型的血管祖细胞(S)的供应以某种方式耗尽或这些细胞功能受损。如果VPC的“备件”可以外包，修复过程就可以以适当的间隔加快，动脉粥样硬化的后果可能会无限期地推迟。具体目的1：测定幼龄和老年(野生型和载脂蛋白E-/-)小鼠的全骨髓细胞或谱系阴性侧群(LIN-SP)细胞的数量组成(FACS分析)、子代功能特征和基因表达表型(微阵列分析)；特定目的2：通过检测未分离的骨髓细胞、浓缩的linSP细胞以及从幼年和老年(野生型和载脂蛋白E-/-)小鼠获得的去掉lin-SP组分的骨髓细胞抑制ApoE-/-小鼠血浆中升高的趋化细胞因子和生长因子水平以及防止动脉粥样硬化病变形成的作用，确定骨髓中具有抗动脉粥样硬化功效的LIN-SP组分中包含有合格的VPC；具体目标3：在年轻apoE-/-和野生型BM的lin-SP组分中，确定a)候选VPC(CVPC，衰老小鼠中耗尽或功能受损的细胞)的相对有效性，b)未分离的lin-SP细胞减去CVPC(USP-CVPC)，以及c)未分离的linSP细胞(USP)在抑制ApoE-/-小鼠血浆IL-6、VEGF和其他炎症标志物水平升高和预防动脉粥样硬化方面的相对有效性；目的4：探讨A4-整合素、血管细胞黏附分子-1和E-选择素在载脂蛋白E-/-小鼠慢性损伤血管壁移植中的作用。作为推论，将描述细胞植入与非细胞自主机制对血管修复的相对贡献。