Cardiomyocyte Non-autonomous Factors and Cardiac Regeneration in Large Mammals

项目摘要 与低等脊椎动物的心肌细胞相比，成年哺乳动物的心肌细胞具有非常有限的 由于细胞周期退出而产生的再生潜力。有趣的是，新生小鼠保持心脏再生 我们最近的研究表明，1日龄的猪也可以再生失去的能力 心肌梗死(MI)后的心肌反应。这种再生是由细胞增殖调节的。 先前存在的CMS，当CMS永久退出细胞周期时不会发生这种情况。潜在的机制 损伤挂载的再生反应，特别是大型哺乳动物的损伤再生反应，目前还没有完全了解。然而， 研究潜在的机制可能会为未来的治疗干预确定新的靶点。 最近对鱼类和啮齿动物的研究强调了血管化和自主神经的关键重要性。 斑马鱼和新生小鼠心脏再生心肌的神经支配。除了它们的功能之外 提供营养物质，运输代谢产物并使其适应压力，目前尚不清楚血管和 神经细胞也通过旁分泌相互作用促进CM的增殖。有趣的是，我们的初步数据 支持由血管内皮细胞和外周血细胞分泌的可溶性因子，如细胞因子 交感神经元显著刺激共培养的人诱导多能干细胞的细胞周期活动 细胞来源的CMS，提示非心肌细胞-CM相互作用在调控CM增殖中起关键作用 大型哺乳动物的心脏在受伤后。在这个项目中，我们将利用已经建立的高再生能力 实验研究非心肌细胞在损伤诱导的心脏损伤中的作用 大型哺乳动物的再生。提出了两个具体目标。目标1是定义早期的作用 损伤心脏再生中的血运重建。我们将检验这一假说 血管重建是新生猪心脏再生所必需的，并决定血管生成 通过血管内皮细胞和/或血管内皮细胞释放促肌原因子促进心脏再生 肌细胞和/或通过新生功能血管的形成来维持CM的活性。目标2是 阐明自主神经支配在损伤心脏再生中的作用。我们将测试 假设神经支配是新生猪损伤后心脏再生所必需的，并确定 生物材料介导的血管生成和神经营养因子心外膜递送促进心脏再生 新生仔猪心肌梗死后。

Project Summary In contrast to the cardiomyocytes (CMs) from lower vertebrates, adult mammalian CMs possess very limited regenerative potential as a result of cell cycle exit. Interestingly, neonatal mice retain cardiac regenerative capacity, which is lost by postnatal day 7. We have recently shown that 1-day-old pigs can also regenerate lost myocardium in response to myocardial infarction (MI). This regeneration is mediated by the proliferation of preexisting CMs, which does not occur when CMs permanently exit the cell cycle. Mechanisms underlying the injury-mounted regenerative response especially in large mammals are not fully understood. However, investigating underlying mechanisms is likely to identify novel targets for future therapeutic interventions. Recent studies in fish and rodents emphasized the critical importance of vascularization and autonomic innervation of the regenerating myocardium in zebrafish and neonatal mouse hearts. Besides their function to provide nutrients, transport metabolites and enable adaptation to stress, it is unknown whether vascular and neuronal cells, via paracrine interactions, also promote CM proliferation. Intriguingly, our preliminary data support the idea that soluble factors, e.g., cytokines, secreted from vascular endothelial cells and peripheral sympathetic neurons significantly stimulate cell cycle activity of co-cultured human induced pluripotent stem cells-derived CMs, suggesting a critical role of nonmyocyte-CM interactions in modulating CM proliferation in hearts of larger mammals post injury. In this project, we will exploit the established high regenerative capacity of the neonatal pig heart model to experimentally address the role of nonmyocytes in injury-induced cardiac regeneration in large mammals. Two specific aims are proposed. Aim 1 is to define the role of early revascularization in injury-mounted cardiac regeneration. We will test the hypothesis that early revascularization is essential for cardiac regeneration in neonatal pigs, and determine whether angiogenesis promotes cardiac regeneration through the release of pro-myogenic factors from endothelial and/or smooth muscle cells and/or via de novo formation of functional vessels for maintenance of CM viability. Aim 2 is to delineate the role of autonomic innervation in injury-mounted cardiac regeneration. We will test the hypothesis that innervation is essential for post injury cardiac regeneration in neonatal pigs, and determine if biomaterial-mediated epicardial delivery of angiogenic and neurotrophic factors enhances cardiac regeneration in neonatal pigs post MI.