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 孕产妇糖尿病诱导相邻心脏缺陷（CHD）形成，而潜在的机制仍然是 不清楚。母体糖尿病会诱导发育中的胚胎和短期妊娠缺氧引起的缺氧会引起缺氧 CHD。缺氧和DNA高甲基化已在人类疾病中相互联系。 DNA高甲基化是 在CHD中暗示，包括左心脏综合征（HLHS），一种复杂而严重的CHD类型。我们发现 这种母节糖尿病会增强缺氧并增加发育中心的DNA甲基化。缺氧 诱导因子1α（HIF-1α）上调了两个从头DNA甲基转移酶（DNMT3A和DNMT3B） 在发育中的小鼠心脏中的心脏祖细胞中，或源自人诱导多能干细胞 （IPSC）。通过去除早期心脏NKX2.5+中的DNMT3A和DNMT3B来阻塞DNA高甲基化 祖细胞在糖尿病妊娠中改善了所有CHD类型。那我们假设糖尿病 诱导缺氧并触发缺氧诱导因子1α（HIF-1α）途径的激活， 通过上调DNMT3A/b，可以诱导DNA高甲基化。抑制缺氧，HIF-1α或DNA 高甲基化或双DNMT3A/B缺失消除了心脏祖细胞的功能缺陷 导致心肌细胞和心脏功能的减少和改善。第一个心脏场 在这种严重类型的CHD中，缺陷导致HLHS形成和心脏功能障碍。测试我们的 假设，我们提出了三个具体目标。 AIM 1将确定母体糖尿病是否引起 缺氧导致早期心脏祖细胞中DNA高甲基化，导致CHD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CHD。 AIM 2将调查孕产妇的作用 糖尿病诱导的基因失调中的DNA高甲基化导致早期功能缺陷 心脏祖细胞和第一个心脏场。我们将确定DNA是否在双心脏中的高甲基化 田间通过使用糖尿病妊娠的CHD和心肌细胞功能障碍来改变基因表达 早期心脏祖细胞中的DNMT3A/B双重缺失。 AIM 3将确定HIF-1α是否增强 活性和随之而来的DNA高甲基化有助于HLHS的心肌细胞功能障碍 糖尿病怀孕。我们假设HIF-1α途径和DNA高甲基化的持续激活 在母体糖尿病引起的CHD中导致心肌细胞功能障碍。成功完成将剖析 缺氧和DNA甲基化在糖尿病诱导的CHD中的关键作用，并为机械见解提供 改善CHD患者的心肌细胞功能。