Muscle-Resident Stem Cells for Angiogenesis and Vascular Maturation in PAD

用于 PAD 血管生成和血管成熟的肌肉驻留干细胞

• 批准号: 8707552
• 负责人: Christopher D Kontos
• 金额: $ 18.75万
• 依托单位: DUKE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-08-01 至 2016-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8707552
• 关键词: Arteries; Automobile Driving; BCL2 gene; Basal lamina; Blood Vessels; CSPG4 gene; Cardiomyopathies; Cell Therapy; Cells; Coronary heart disease; Dependovirus; Diphtheria Toxin; Electrons; Embryo; Endothelial Cells; Erythrocytes; Flow Cytometry; Genetic Variation; Goals; Growth; Growth Factor; Heart Diseases; Hematological Disease; Heterogeneity; Human; Hyperplasia; Hypertrophy; Immunofluorescence Microscopy; In Vitro; Inherited; Intervention; Investigation; Ischemia; Knockout Mice; Label; Lead; Limb structure; Link; Lower Extremity; Lung diseases; Mediating; Modality; Molecular Chaperones; Morbidity - disease rate; Mus; Muscle; Muscle Cells; Muscle Fibers; Muscle function; Muscle satellite cell; Mutation; Myoblasts; Myopathy; Myosin Heavy Chains; Obstruction; PECAM1 gene; Pericytes; Peripheral; Peripheral arterial disease; Play; Prevention; Production; Proteins; Quantitative Trait Loci; Role; Sarcolemma; Serotyping; Skeletal Muscle; Smooth Muscle; Smooth Muscle Actin Staining Method; Source; Staining method; Stains; Stem cells; Tamoxifen; Testing; angiogenesis; base; cell growth; control trial; density; effective therapy; in vivo; insight; interest; meetings; mortality; muscle necrosis; muscle regeneration; neovascularization; postnatal; promoter; public health relevance; response; satellite cell; stem; stem cell differentiation; success; tissue regeneration

DESCRIPTION (provided by applicant): Peripheral artery disease (PAD) causes substantial morbidity and mortality but has few effective treatments. Strategies to promote angiogenesis for the treatment of PAD have met with little success, which has led to the investigation of stem cell-based interventions. Beneficial effects of cell-based approaches are generally thought to result from accessory effects, such as the local secretion of vascular growth factors, although less is known about whether resident muscle progenitor cells in ischemic muscle can differentiate into new blood vessels and how this can be achieved. Preliminary studies in our lab have demonstrated that the co-chaperone protein Bag3 plays an important role in the protection of muscle tissue from ischemia. Bag3 is known to play an important role in muscle, as loss of Bag3 in mice results in a fulminant myopathy, and mutation in human BAG3 has been linked to inherited cardiomyopathies. We investigated Bag3's effects in limb ischemia after it was identified as a component of the limb survival (Lsq1) quantitative trait locus (QTL). In addition t effects on muscle cells, we unexpectedly found that exogenous muscle-specific expression of Bag3 with adeno-associated virus (AAV6) induced a dramatic increase in angiogenesis in non-ischemic and ischemic muscle. Moreover, Bag3 expression in muscle significantly increased vascular maturation, as evidenced by smooth muscle actin (SMA)-positive vessels. Bag3 induced an increase in Pax7+ progenitor cells, which stained positive for SMA and CD31, suggesting that Bag3 induced an increase in vascular progenitor cells. Muscle contains a relatively large number of Pax7+ progenitor cells, which play an important role in postnatal muscle regeneration through hyperplasia but not hypertrophy. Evidence has linked Pax7+ progenitor cells to both endothelial and pericyte lineages. Based on these observations, we hypothesize that expression of Bag3 in muscle drives differentiation of Pax7+ cells into vascular cells, which may provide a source of endogenous vascular stem cells for the treatment of PAD. To test this hypothesis, the Specific Aims of this proposal are to: 1) Determine whether Pax7+ muscle progenitor cells can differentiate into endothelial or peri- endothelial cells after exogenous expression of Bag3 in skeletal muscle cells in vivo or in vitro; and 2) Determine whether Pax7+ cells are required for angiogenesis and vascular maturation after Bag3 expression in skeletal muscle in vivo. This exploratory R21 proposal is submitted in response to PA-09-248, "Directed Stem Cell Differentiation for Cell-Based Therapies for Heart, Lung, and Blood Diseases", with the goal of determining the effects of skeletal muscle-specific Bag3 expression on the differentiation of Pax7+ progenitor cells into vascular cells as a potential treatment for PAD. Accomplishing the Specific Aims of this proposal will provide important insights into the mechanisms of muscle stem cell differentiation and crosstalk between blood vessels and muscle cells in skeletal muscle tissue. Furthermore, these studies may lead to effective therapies for the treatment of PAD.

描述（由申请人提供）：周围动脉疾病（PAD）会引起大量的发病率和死亡率，但几乎没有有效的治疗方法。促进血管治疗的血管生成的策略几乎没有成功，这导致对干细胞的干预进行了研究。通常认为，基于细胞的方法的有益作用是辅助作用，例如血管生长因子的局部分泌，尽管缺血性肌肉中常驻肌肉祖细胞是否可以区分新的血管以及如何实现这一目标。我们实验室中的初步研究表明，辅助蛋白BAG3在保护肌肉组织免受缺血的保护中起着重要作用。众所周知，BAG3在肌肉中起着重要作用，因为小鼠的BAG3损失导致暴发性肌病，而人Bag3中的突变与遗传性心肌病有关。我们研究了BAG3在肢体缺血中的作用，因为它被确定为肢体存活（LSQ1）定量性状基因座（QTL）的组成部分。此外，T对肌肉细胞的影响，我们出乎意料地发现，BAG3的外源肌肉特异性表达与腺相关病毒（AAV6）引起了非缺血性和缺血性肌肉的血管生成的急剧增加。此外，肌肉中的BAG3表达显着增加了血管成熟，如平滑肌肌动蛋白（SMA）阳性血管所证明的那样。 BAG3诱导PAX7+祖细胞的增加，该细胞对SMA和CD31染色阳性，这表明BAG3诱导了血管祖细胞的增加。肌肉包含相对较大的PAX7+祖细胞，它们在产后肌肉再生中通过增生而不是肥大起着重要作用。证据已将PAX7+祖细胞与内皮和周细胞谱系联系起来。基于这些观察结果，我们假设BAG3在肌肉中的表达将PAX7+细胞分化为血管细胞，这可能提供内源性血管干细胞的来源，用于治疗PAD。为了检验这一假设，该提案的具体目的是：1）确定PAX7+肌肉祖细胞是否可以在体内或体外体内骨骼肌细胞外源性表达BAG3后分化为内皮细胞或周围内皮细胞； 2）确定在体内骨骼肌表达BAG3表达后血管生成和血管成熟是否需要PAX7+细胞。该探索性R21提案是针对PA-09-248提交的，“针对心脏，肺和血液疾病的基于细胞的疗法的定向干细胞分化”，目的是确定骨架肌肉特异性BAG3表达对PAX7+祖细胞分化为血管细胞的骨骼肌肉特异性BAG3表达的影响，作为垫板的潜在治疗。完成该提案的具体目的将为骨骼肌组织中血管和肌肉细胞之间的肌肉干细胞分化和串扰的机制提供重要的见解。此外，这些研究可能会导致有效的PAD治疗疗法。