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: 7276666
• 负责人: Pascal J. Goldschmidt-Clermont
• 金额: $ 29.38万
• 依托单位: UNIVERSITY OF MIAMI SCHOOL OF MEDICINE
• 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/7276666
• 关键词: Accounting; Adult; Age; Aging; Angioblast; Apolipoprotein E; Arterial Fatty Streak; Arteries; Atherosclerosis; Attenuated; Blood Circulation; Blood Vessels; Bone Marrow; Bone Marrow Cells; Cardiovascular Diseases; Cardiovascular system; Cells; Cellular biology; Characteristics; Cholesterol; Chronic; Data; Development; Diet; E-Selectin; Embryo; Endothelial Cells; Engraftment; Fatty acid glycerol esters; Gene Expression; Growth Factor; Healed; Hematopoietic stem cells; Homeostasis; Homing; Hyperlipidemia; Impairment; Individual; Inflammatory; Infusion procedures; Injury; Integrins; Interleukin-6; Marrow; Mediating; Microarray Analysis; Morbidity - disease rate; Mus; Outsourcing; Peripheral; Phenotype; Plasma; Population; Prevention; Process; Proliferating; Recruitment Activity; Rejuvenation; Relative (related person); Research Personnel; Role; Side; Site; Smooth Muscle Myocytes; Source; Stem cells; Testing; Therapeutic; Time; Vascular Cell Adhesion Molecule-1; Vascular Endothelial Growth Factors; Wound Healing; atherogenesis; base; cell type; congenic; cytokine; exhaust; exhaustion; feeding; functional disability; healing; injured; injury and repair; mortality; mouse model; novel; peripheral blood; pre-clinical; prevent; programs; repaired; response; restoration; stem

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）：动脉粥样硬化代表响应于血管壁反复损伤的异常的、持续的修复性炎症过程。事实上，心血管系统不断受到多种损害，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/血管祖细胞。我们最近发现，在已建立的动脉粥样硬化小鼠模型（喂食高脂肪胆固醇、西式饮食的 ApoE -/- C57/B6 小鼠）中，长期施用全骨髓 (BM) 细胞可显着减少动脉粥样硬化病变的形成，即使在 ApoE 基因表达没有恢复和血浆胆固醇水平正常化 (>1200 mg/dl) 的情况下也是如此。此外，来自年轻而非老年 ApoE-/- 小鼠的 BM 细胞能够实现血管再生和预防动脉粥样硬化。该数据强调了干细胞/血管祖细胞在血管愈合和动脉粥样硬化形成中的重要性，并为使用干细胞/祖细胞疗法作为动脉粥样硬化的新型预防和/或治疗策略提供了支持，特别是对于骨髓及其老化代表心血管系统长期完整性瓶颈的个体。在这个项目中，我们建议检验这样一个假设：在终生修复动脉粥样硬化之后，维持心血管系统稳态所需的特定类型的血管祖细胞（VPC）的供应不知何故耗尽，或者这些细胞功能受损。如果 VPC“备件”可以外包，修复过程可以在适当的时间间隔内得到加强，动脉粥样硬化的后果可能会无限期地延迟。具体目标1：确定从年轻小鼠与老年小鼠（野生型和ApoE -/-）获得的全骨髓细胞或谱系阴性侧群（lin-SP）细胞的定量组成（FACS分析）、子代功能特征和基因表达表型（微阵列分析）；具体目标 2：通过测试从年轻小鼠与老年小鼠（野生型和 ApoE -/-）获得的未分级骨髓细胞、富集 linSP 细胞和缺乏 lin-SP 组分的骨髓细胞抑制血浆中 化学细胞因子和生长因子以及预防 ApoE -/- 小鼠动脉粥样硬化病变的形成；具体目标 3：确定年轻 apoE -/- 和野生型 BM 的 lin-SP 部分中 a) 使用目标 1 中确定的标记物分离的候选 VPC（CVPC，在衰老小鼠中耗尽或功能受损的细胞）、b) 未分级的 lin-SP 细胞减去 CVPC (USP-CVPC) 和 c) 未分级的 linSP 细胞 (USP) 的相对功效 抑制 ApoE -/- 小鼠血浆中 IL-6、VEGF 和其他炎症标志物水平升高，并预防动脉粥样硬化；具体目标 4：确定 a4-整合素、VCAM-1 和 E-选择素在介导血管祖细胞植入 apoE-/- 小鼠慢性损伤血管壁中的作用。作为推论，将表征细胞植入与非细胞自主机制对血管修复的相对贡献。