Heightened hypoxia and DNA methylation in heart defects of diabetic embryopathy

糖尿病胚胎病心脏缺陷中缺氧和 DNA 甲基化加剧

• 批准号: 10698172
• 负责人: Wei-Bin Shen
• 金额: $ 75.9万
• 依托单位: UNIVERSITY OF MARYLAND BALTIMORE
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-15 至 2026-07-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10698172
• 关键词: Apoptosis; Binding; Cardiac; Cardiac Myocytes; Cell Proliferation; Cells; Cellular Stress; Complex; Congenital Abnormality; Congenital Heart Defects; DNA; DNA Methylation; DNA Modification Methylases; DNA methylation profiling; DNMT3B gene; DNMT3a; Defect; Development; Diabetes Mellitus; Embryo; Embryonic Heart; Epigenetic Process; Exposure to; Fetal health; Frequencies; Functional disorder; Gene Expression; Genes; HCN4 gene; Heart; Heart Abnormalities; Human; Hyperglycemia; Hypermethylation; Hyperoxia; Hypertrophy; Hypoplastic Left Heart Syndrome; Hypoxia; Hypoxia Inducible Factor; Impairment; Incidence; Inflammation; Mus; Myocardial dysfunction; Pathway interactions; Patients; Pregnancy in Diabetics; Regulatory Element; Rodent Model; Role; Testing; Up-Regulation; Woman; cardiogenesis; diabetic; diabetic embryopathy; epigenetic memory; gestational hypoxia; glycemic control; heart function; human disease; hypoxia inducible factor 1; imprint; improved; induced pluripotent stem cell; inhibitor; insight; maternal diabetes; non-genetic; offspring; prevent; progenitor; programs; promoter; stem cell differentiation

Summary Maternal diabetes induces congenial heart defects (CHDs) formation and the underlying mechanism is still unclear. Maternal diabetes induces hypoxia in the developing embryo and short-term gestational hypoxia induces CHDs. Hypoxia and DNA hypermethylation have been interlinked in human diseases. DNA hypermethylation is implicated in CHDs including hypoplastic left heart syndrome (HLHS), a complex and severe CHD type. We found that maternal diabetes enhanced hypoxia and increased DNA methylation in the developing heart. Hypoxia inducible factor 1 alpha (HIF-1α) up-regulated the two de novo DNA methyltransferase (DNMT3a and DNMT3b) in cardiac progenitors in the developing mouse hearts or derived from human inducible pluripotent stem cells (iPSCs). Blockage of DNA hypermethylation by removing DNMT3a and DNMT3b in early cardiac Nkx2.5+ progenitors ameliorated all CHD types in diabetic pregnancy. Thus, we hypothesize that maternal diabetes induces hypoxia and triggers the activation of the hypoxia inducible factor 1 alpha (HIF-1α) pathway, which induces DNA hypermethylation by up-regulating DNMT3a/b. Inhibition of hypoxia, HIF-1α or DNA hypermethylation or double DNMT3a/b deletion abrogates the functional deficits in cardiac progenitors leading to CHD reduction and improvement of cardiomyocyte and cardiac function. First heart field defects contribute to HLHS formation and cardiac dysfunction in this severe type of CHDs. To test our hypothesis, we proposed three specific aims. Aim 1 will determine whether maternal diabetes-induced hypoxia is responsible for DNA hypermethylation in early cardiac progenitors leading to CHD formation. We will examine whether hypoxia increases DNA methylation in early cardiac progenitors by up-regulating DNMT3a/b expression leading to CHDs in diabetic pregnancy. Aim 2 will investigate the role of maternal diabetes-induced DNA hypermethylation in gene dysregulation that results in functional defects in early cardiac progenitors and the first heart field. We will determine whether DNA hypermethylation in both heart fields alters gene expression leading to CHDs and cardiomyocyte dysfunction in diabetic pregnancy by using DNMT3a/b double deletion in early cardiac progenitors. Aim 3 will determine whether heightened HIF-1α activity and consequent DNA hypermethylation contribute to cardiomyocyte dysfunction of HLHS in diabetic pregnancy. We hypothesize that persistent activation of the HIF-1α pathway and DNA hypermethylation contribute to cardiomyocyte dysfunction in maternal diabetes-induced CHDs. Successful completion will dissect the critical role of hypoxia and DNA methylation in diabetes-induced CHDs and provide mechanistic insights for improving cardiomyocyte function in CHD patients.

概括 孕产妇糖尿病诱发先天性心脏病（CHD）形成，其机制仍不清楚 不清楚。母体糖尿病会导致发育中的胚胎缺氧，妊娠期短期缺氧也会导致 冠心病。缺氧和 DNA 高甲基化在人类疾病中是相互关联的。 DNA 高甲基化是 与先心病有关，包括左心发育不全综合征（HLHS），这是一种复杂而严重的先心病类型。我们发现 母亲的糖尿病会加剧发育中心脏的缺氧并增加 DNA 甲基化。缺氧 诱导因子 1 α (HIF-1α) 上调两种 DNA 甲基转移酶（DNMT3a 和 DNMT3b） 在发育中的小鼠心脏的心脏祖细胞中或源自人类诱导多能干细胞 （iPSC）。通过去除早期心脏 Nkx2.5+ 中的 DNMT3a 和 DNMT3b 来阻断 DNA 高甲基化 祖细胞改善了糖尿病妊娠期间所有类型的先心病。因此，我们假设母亲患有糖尿病 诱导缺氧并触发缺氧诱导因子 1 α (HIF-1α) 通路的激活， 它通过上调 DNMT3a/b 诱导 DNA 高甲基化。抑制缺氧、HIF-1α 或 DNA 超甲基化或双重 DNMT3a/b 缺失消除了心脏祖细胞的功能缺陷 导致冠心病减少并改善心肌细胞和心脏功能。第一心田 在这种严重类型的先心病中，缺陷会导致 HLHS 形成和心功能障碍。来测试我们的 假设，我们提出了三个具体目标。目标 1 将确定母亲是否诱发糖尿病 缺氧导致早期心脏祖细胞 DNA 高甲基化，导致冠心病形成。 我们将检查缺氧是否通过上调来增加早期心脏祖细胞中的 DNA 甲基化 DNMT3a/b 表达导致糖尿病妊娠中的冠心病。目标 2 将调查母亲的作用 糖尿病引起的基因失调中的 DNA 高甲基化导致早期功能缺陷 心脏祖细胞和第一心脏区域。我们将确定双侧心脏中的 DNA 是否超甲基化 领域改变基因表达导致糖尿病妊娠中的冠心病和心肌细胞功能障碍 早期心脏祖细胞中的 DNMT3a/b 双缺失。目标 3 将确定 HIF-1α 是否升高 HLHS 活性和随之而来的 DNA 高甲基化导致 HLHS 心肌细胞功能障碍 糖尿病妊娠。我们假设 HIF-1α 通路的持续激活和 DNA 高甲基化 导致母亲糖尿病诱发的先心病的心肌细胞功能障碍。成功完成将进行剖析 缺氧和 DNA 甲基化在糖尿病引起的先心病中的关键作用，并提供机制见解 改善冠心病患者的心肌细胞功能。