CARDIAC HYPERTROPHY INDUCED METABOLIC GENE REGULATION

心脏肥厚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 对病理生理刺激的反应而经历肥大生长 如慢性高血压和瓣膜疾病。从 正常到肥厚的心室有特征性的分子标记 表型变化，包括能量代谢基因的开关 以脂肪酸为主的β-氧化调控计划(粮农组织) 使氧气效率更高的糖酵解，重新激活胎儿 新陈代谢。肥大信号通路知之甚少 将细胞外刺激与转录调控联系起来。《博大》 这项提案的目标是描绘分子调控信号 这最终有助于降低粮农组织在 肥大。这项建议是专门设计的，目的是i)描述 培养细胞中脂肪酸β-氧化基因转录的变化 新生大鼠心肌细胞肥大及其机制的研究 利用Northern调节反应的特定顺式作用元件 和Western印迹分析、核糖核酸酶保护和瞬时基因转移 对粮农组织酶基因启动子的研究；ii)确定特定的 与细胞中的反应元件结合的转录调控因子 心肌细胞肥大过程中的β-氧化基因启动子 利用电泳迁移率改变分析，共转染，Northern 蛋白质印迹分析、核糖核酸酶保护和免疫荧光； 三)确定监管者的活动是否增加 在肥大过程中利用体外和体内的磷酸化事件 已知的信号转导抑制剂--体内磷酸化研究 级联反应和磷酸化位点突变，重点是 丝裂原活化蛋白激酶途径。长期目标将是 以确定是否重新激活这个胎儿代谢基因程序 和/或下调脂肪酸β-氧化导致 不适应的肥大表型，从而促进向 心力衰竭。如果是这样的话，上述研究将确定 治疗干预的潜在目标，旨在延迟或 甚至可以防止进展为终末期心肌病。

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.