Metabolic Control of Epigenetic Reprogramming in Neovascularization

项目摘要 通过扩大内皮细胞数量来恢复微血管系统和改善血流的能力 在体内的细胞，将是心血管医学的重大进展，并创造一种新的治疗方法 心血管疾病。拟议的研究，旨在确定O-GlcN酰化在 转分化和表观遗传可塑性，可能揭示新的血管形成和发现的新机制 治疗性血管生成和血管生成的新途径(Carmeliet，2005，Isner 1999)。 炎症信号通路的激活是促使成纤维细胞血管生成所必需的 转分化并在体外成为内皮细胞(Sayed，2015)。这一过程需要细胞自主 先天免疫信号，触发表观遗传修饰物表达和活性的全球变化(Lee， 2012年)。术语“转化”描述了先天免疫信号促进 表观遗传可塑性和表型流动性。最近，已有研究表明，糖酵解转变有助于 通过增加组蛋白乙酰化的核乙酰辅酶A进行转分化(Lai，2019)。 尽管这种糖酵解开关将新陈代谢与表观遗传模型联系起来，但其他代谢物对 表观遗传学在新生血管形成中的可塑性仍未被探索。初步数据表明，O-GlcN酰化， 和营养驱动的翻译后修饰(PTM)，在血管生成中显著升高 后肢缺血后的转分化和新生血管。这一观察结果引发了令人兴奋的 O-GlcN酰化在血管转分化中将细胞命运可塑性与代谢联系起来的可能性，以及 靶向这种PTM可能是再生医学的一条新的治疗途径。 最重要的假设是O-GlcN酰化促进了缺血后恢复的新生血管形成 通过促进细胞命运可塑性而造成的损伤，以及通过遗传和基因突变对O-GlcN酰化的扰动 药物操作将减弱转分化和减少新生血管。最直接的 目标是确定血管生成转分化是否需要O-GlcN酰化，并确定靶点 O-GlcN酰化对血管转分化和细胞命运流动性的表观可塑性和流动性的影响 新生血管。转分化中O-GlcN酰化的拟议研究将确定一种 细胞可塑性的表观遗传机制和增强内源性的新治疗靶点 心血管疾病的新生血管治疗。长期目标是评估 靶向O-GlcN酰化促进非缺血区和缺血区血管恢复的疗效 心血管疾病的模型，如心力衰竭和心肌梗死。 目的1：确定O-GlcN酰化在体外转分化和DNA可及性中的作用。 目的2：确定O-GlcN酰化在体内转分化和新生血管中的作用。

Project Summary The ability to restore the microvasculature and improve perfusion, by expanding the population of endothelial cells in vivo, would be a major advancement in cardiovascular medicine and create a novel therapeutic approach to cardiovascular disease. The proposed studies, aimed at identifying the role of O-GlcNAcylation in transdifferentiation and epigenetic plasticity, may reveal a novel mechanism of neovascularization and uncover new avenues for therapeutic angiogenesis and vasculogenesis (Carmeliet, 2005, Isner 1999). Activation of inflammatory signaling pathways is required to drive fibroblasts to undergo angiogenic transdifferentiation and become endothelial cells in vitro (Sayed, 2015). This process requires cell autonomous innate immune signaling, which triggers global changes in expression and activity of epigenetic modifiers (Lee, 2012). The term “transflammation” describes the process by which innate immune signaling promotes epigenetic plasticity and phenotypic fluidity. Recently, it has been shown that a glycolytic shift contributes to transdifferentiation by increased nuclear acetyl-CoA for histone acetylation (Lai, 2019). Although this glycolytic switch links metabolism to epigenetic modelling, the contribution of other metabolites to epigenetic plasticity in neovascularization remains unexplored. Preliminary data indicate that O-GlcNAcylation, and nutrient driven post-translational modification (PTM), is significantly elevated in angiogenic transdifferentiation and neovascularization following hindlimb ischemia. This observation raises the exciting possibility that O-GlcNAcylation links cell fate plasticity to metabolism in vascular transdifferentiation, and that targeting this PTM may be a new therapeutic avenue in regenerative medicine. The overarching hypothesis is that O-GlcNAcylation enhances neovascularization in recovery from ischemic injury by facilitating cell fate plasticity, and that perturbations to O-GlcNAcylation through genetic and pharmacologic manipulation will attenuate transdifferentiation and diminish neovascularization. The immediate goal will be to determine if O-GlcNAcylation is required for angiogenic transdifferentiation and to identify targets of O-GlcNAcylation contributing to epigenetic plasticity and cell fate fluidity in vascular transdifferentiation and neovascularization. The proposed studies on O-GlcNAcylation in transdifferentiation will identify an epigenetic mechanism for cellular plasticity and a novel therapeutic target to enhance endogenous neovascularization for treatment of cardiovascular disease. The long term goal is to evaluate the therapeutic efficacy of targeting O-GlcNAcylation to enhance vascular recovery in non-ischemic and ischemic models of cardiovascular disease, such as heart failure and myocardial infarction. Aim 1: Determine the role of O-GlcNAcylation in transdifferentiation and DNA accessibility in vitro. Aim 2: Determine the role of O-GlcNAcylation in transdifferentiation and neovascularization in vivo.