CARDIAC HYPERTROPHY INDUCED METABOLIC GENE REGULATION

心脏肥大引起的代谢基因调节

• 批准号: 2593596
• 负责人: PHILIP M BARGER
• 金额: $ 7.68万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-04-08 至 2003-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2593596
• 关键词: RNase protection assay; bioenergetics; congestive heart failure; fatty acid metabolism; genetic regulatory element; heart cell; heart enlargement; immunofluorescence technique; laboratory rat; mitogen activated protein kinase; molecular pathology; muscle cells; northern blottings; phosphorylation; tissue /cell culture; western blottings

Cardiac hypertrophy and congestive heart failure are significant causes of morbidity and mortality in the United States. The human heart undergoes hypertrophic growth in response to pathophysiologic stimuli such as chronic hypertension and valvular disease. The transition from normal to hypertrophied ventricle is marked by characteristic molecular phenotypic changes, including a switch in the energy metabolic gene regulatory program from predominantly fatty acid beta-oxidation (FAO) to the more oxygen-efficient glycolysis, a reactivation of fetal metabolism. Little is known about the hypertrophy signaling pathway linked extracellular stimulus to transcriptional regulation. The broad goals of this proposal are to delineate the molecular regulatory signals which ultimately contribute to down-regulation of FAO during hypertrophy. This proposal is specifically designed to i) characterize alterations in fatty acid beta-oxidation gene transcription in cultured rat neonatal cardiocytes undergoing hypertrophy and to delineate the specific cis-acting elements mediating that response utilizing Northern and Western blot analysis, RNase protection, and transient gene transfer studies with FAO enzyme gene promoters; ii) identify the specific transcriptional regulators that bind to the responsive elements in the promoters of beta-oxidation genes during cardiocyte hypertrophy utilizing electrophoretic mobility shift assay, cotransfection, Northern and Western blot analysis, RNase protection, and immunofluorescence; iii) determine whether the activity of the regulators are increased during hypertrophy by phosphorylation events utilizing in vitro and in vivo phosphorylation studies, inhibitors of known signal transduction cascades, and phosphorylation site mutations with emphasis on the mitogen-activated protein kinase pathway. The longterm goals will be to determine whether reactivation of this fetal metabolic gene program and/or downregulation of fatty acid beta-oxidation leads to a maladaptive hypertrophied phenotype and thus promotes the transition to heart failure. If so, the studies outlined above will have identified potential targets for therapeutic interventions aimed at delaying or even preventing progression to end-stage cardiomyopathy.

心脏肥大和充血性心力衰竭是重要原因 美国的发病率和死亡率。 人类的心脏 响应病理生理刺激而发生肥大性生长 如慢性高血压、瓣膜病等。 过渡从 正常至肥厚的心室以特征分子为标志 表型变化，包括能量代谢基因的转换 主要脂肪酸β-氧化的监管计划（FAO） 提高氧气效率的糖酵解，胎儿的重新激活 代谢。 关于肥大信号通路知之甚少 将细胞外刺激与转录调节联系起来。 广义的 该提案的目标是描绘分子调控信号 这最终导致粮农组织在 肥大。 该提案专门设计用于 i) 表征 培养物中脂肪酸β-氧化基因转录的变化 大鼠新生心肌细胞经历肥大并描绘出 利用 Northern 介导该反应的特定顺式作用元件 和蛋白质印迹分析、RNase 保护和瞬时基因转移 与FAO酶基因启动子的研究； ii) 确定具体的 与反应元件结合的转录调节因子 心肌细胞肥大期间β-氧化基因的启动子 利用电泳迁移率变动分析、共转染、Northern 蛋白质印迹分析、RNase 保护和免疫荧光； iii) 确定监管机构的活动是否增加 在利用体外和体内磷酸化事件导致肥大期间 体内磷酸化研究，已知信号转导的抑制剂 级联和磷酸化位点突变，重点是 有丝分裂原激活蛋白激酶途径。 长期目标将是 以确定该胎儿代谢基因程序是否重新激活 和/或脂肪酸β-氧化的下调导致 适应不良的肥大表型，从而促进向 心脏衰竭。 如果是这样，上述研究将确定 旨在延迟或延缓治疗干预的潜在目标 甚至可以预防进展为终末期心肌病。