Epigenetic control of smooth muscle cell phenotype during microvascular remodeling

微血管重塑过程中平滑肌细胞表型的表观遗传控制

• 批准号: 9884787
• 负责人: Delphine Gomez
• 金额: $ 37.63万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-04-01 至 2024-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9884787
• 关键词: Address; Affect; Age-Years; Aging; Amputation; Area; Arteries; Back; Binding; Blood; Blood Vessels; Blood capillaries; Blood flow; Caliber; Cell Communication; Cell Differentiation process; Cell Lineage; Cell Proliferation; Cell physiology; Cells; Chimeric Proteins; DNA; DNA Methylation; Data; Defect; Development; Disease; Docking; Embryonic Development; Endothelial Cells; Engineering; Enzymes; Epigenetic Process; Event; Excision; Gangrene; Gene Activation; Gene Expression; Genes; Genetic Transcription; Goals; Histones; Hypoxia; In Vitro; Individual; Investigation; Investments; Ischemia; KDM1A gene; Lead; Ligation; Lower Extremity; Lysine; MYH11 gene; Maintenance; Mediating; Memory; Methyltransferase; Modeling; Muscle; Pathogenesis; Patients; Perfusion; Peripheral arterial disease; Phenotype; Play; Process; Reperfusion Therapy; Repression; Risk Factors; Role; Site; Smooth Muscle Myocytes; System; Testing; Therapeutic; Tissues; Ulcer; Vascular Endothelial Growth Factors; Vascular remodeling; Vascularization; angiogenesis; arteriole; ascending aorta; cell dedifferentiation; claudication; demethylation; density; epigenome editing; improved; in vivo; migration; myocardin; novel; novel therapeutic intervention; novel therapeutics; prevent; promoter; recruit; therapeutic angiogenesis; transcription factor

PROJECT SUMMARY Peripheral Artery Disease (PAD) is an occlusive disease of the lower extremity arteries leading to debilitating complications (e.g. claudication, amputation) due to defect in proper vascularization and efficient vascular remodeling. Recent attempts to promote therapeutic angiogenesis by VEGF therapies in patients with PAD have failed, perhaps because these strategies have only not targeted smooth muscle cells (SMC), cells that are essential for remodeling of capillaries and terminal arterioles (i.e. arteriogenesis) to increase blood distribution to ischemic regions. Arteriogenesis relies on the ability of SMC to be plastic and undergo a reversible phenotypic switching where they transiently downregulate their contractile apparatus, participate in capillary investment, and then re-differentiate back to the contractile state. However, the understanding of the mechanisms controlling SMC ability to re-differentiate and the retention of their lineage memory in vivo is limited. We previously identified an epigenetic signature specific to the SMC lineage consisting of the dimethylation of the lysine 4 of histone 3 (H3K4me2) on the promoters of the SMC marker genes (referred as SMC-H3K4me2) that is retained during SMC dedifferentiation. These observations suggest that SMC-H3K4me2 could play a pivotal role in maintenance of SMC identity and retention of lineage memory and could be a key mechanism controlling SMC participation in arteriogenesis. Studies in this proposal will test the central hypothesis that H3K4me2 controls the SMC differentiation state and enables SMC involvement in collateral capillary investment and muscularization during arteriogenesis by promoting the recruitment of TET2 on SMC marker genes. Consistent with this hypothesis, our preliminary studies, utilizing a novel locus-specific epigenome editing system to remove specifically H3K4me2 on the SMC marker genes, provide evidence that SMC-H3K4me2 tightly regulates SMC differentiation state and show that H3K4me2 interacts with Ten-eleven translocation (TET2), a key enzyme mediating DNA demethylation and a master regulator of SMC differentiation. Our central hypothesis will be further tested by addressing the following specific aims. Aim 1 will determine the impact of loss of SMC-H3K4me2 on SMC participation to arteriogenesis. The functional consequences of SMC-H3K4me2 removal on SMC phenotype, their ability to invest capillaries, as well as tissue reperfusion will be evaluated. Aim 2 will test the hypothesis that H3K4me2 plays a key role in promoting SMC differentiation by serving as a docking site for TET2 on the SMC marker genes. We expect the completion of these studies will lead to the identification of novel mechanisms controlling smooth muscle cell identity, plasticity, and lineage memory and their participation to beneficial microvascular arterialization and maturation. These results could serve from the development of new strategies for enhancing therapeutic vascularization in patients with PAD.

项目摘要 外周动脉疾病（PAD）是一种下肢动脉闭塞性疾病， 由于适当血管化和有效血管化缺陷导致的并发症（例如跛行、截肢） 重塑最近尝试在PAD患者中通过VEGF疗法促进治疗性血管生成， 失败了，也许是因为这些策略只是没有针对平滑肌细胞（SMC）， 对于毛细血管和末端小动脉的重塑（即动脉生成）以增加血液分布至关重要 到缺血区域。动脉形成依赖于SMC的可塑性和可逆的表型分化能力。 转换，其中它们瞬时下调其收缩装置，参与毛细血管投资， 然后重新分化回到收缩状态。然而，对控制机制的理解 SMC再分化的能力和它们在体内的谱系记忆的保留是有限的。我们之前发现 SMC谱系特异性的表观遗传标记，由组蛋白3的赖氨酸4的二甲基化组成 （H3 K4 me 2）在SMC标志物基因（称为SMC-H3 K4 me 2）的启动子上，其在细胞周期中保留。 SMC去分化。这些观察结果表明，SMC-H3 K4 me 2可能在维持中发挥关键作用。 SMC身份和谱系记忆的保留，可能是控制SMC参与的关键机制 在动脉生成中。本提案中的研究将检验H3 K4 me 2控制SMC的中心假设 分化状态，使SMC参与侧支毛细血管投资和肌化过程中， 通过促进SMC标记基因上TET 2的募集来促进动脉生成。与这一假设相一致，我们 初步研究，利用一种新的基因座特异性表观基因组编辑系统特异性去除H3 K4 me 2 为SMC-H3 K4 me 2密切调控SMC分化状态提供了证据， 显示H3 K4 me 2与TET 2相互作用，TET 2是介导DNA去甲基化的关键酶 和SMC分化的主要调节剂。我们的中心假设将通过解决 具体目标。目标1将确定SMC-H3 K4 me 2缺失对SMC参与的影响， 动脉生成SMC-H3 K4 me 2去除对SMC表型的功能性后果，它们对SMC表型的调节能力， 将评估毛细血管以及组织再灌注。目的2将检验H3 K4 me 2 通过作为SMC标记物上TET 2的对接位点，在促进SMC分化中起关键作用 基因.我们希望这些研究的完成将导致确定新的机制控制 平滑肌细胞特性、可塑性和谱系记忆及其对有益微血管的参与 动脉化和成熟。这些结果可以用于制定新的战略， PAD患者的治疗性血管化。