Ventricular Remodeling in the Adapted Heart

适应心脏的心室重塑

• 批准号: 6776943
• 负责人: NILANJANA MAULIK
• 金额: $ 36.25万
• 依托单位: UNIVERSITY OF CONNECTICUT SCH OF MED/DNT
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-08-01 至 2008-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6776943
• 关键词: SDS polyacrylamide gel electrophoresis; angiogenesis; apoptosis; cardiovascular stress test; gel mobility shift assay; genetic transcription; heart ventricle; immunocytochemistry; laboratory mouse; laboratory rat; mitogen activated protein kinase; myocardial infarction; myocardial ischemia /hypoxia; myocardium; nuclear factor kappa beta; polymerase chain reaction; protein biosynthesis; protein kinase C; regeneration; terminal nick end labeling; transcription factor; vascular endothelial growth factors; western blottings

DESCRIPTION (provided by applicant): Following myocardial infarction (MI), there is a progressive myocardial remodeling characterized by left ventricular (LV) dilation, contractile dysfunction, myocyte hypertrophy and increased matrix protein formation. The proposed project will examine the molecular mechanism(s) of hypoxic preconditioning (HP)- mediated myocardial remodeling in the infarcted heart by studying cardioprotective parameters at the transcriptional and protein level. We have established the optimal hypoxic preconditioning stimulus in rat MI model (10%O2/90%NS) to initiate capillary/arteriolar formation, increased blood flow and ventricular function in the myocardium. To establish the role of such HP in potentiating the signal transduction process for ventricular remodeling we will examine (i) the expression of VEGF and its tyrosine kinase receptors VEGFR1 (Flt-1) and VEGFR2 (FIk-1), expression and activity of protein kinase C, MAP Kinases-Aim I (ii) the expression and activity of iNOS/eNOS will be determined along with the transcriptional regulation of these factors by NFkB, Stat1-Aim 2 (iii) the extent of endothelial cell (EC) survival and the extent of necrosis/apoptosis, anti-apoptotic proteins Bcl-2, survivin expression, PI-3-Kinase activity, and the extent of AKT/BAD phosphorylation -Aim 3. Our rat MI model subjected to HP before LAD occlusion has significant advantage to study the molecular mechanism of myocardial remodeling over several months. An obligatory role of FIk-1, iNOS and eNOS in VEGF mediated signaling in myocardial angiogenesis/remodeling will be established by the use of Flk1, iNOS-/- and eNOS-/- knockout mice. The endothelial cell proliferation will be studied by BrdU incorporation assay, cardiomyocyte and endothelial cell apoptosis will be studied by double antibody staining, capillary and arteriolar density will be determined by labeling endothelial and smoothe muscle cells using anti-rat CD31 and anti-smooth muscle actin respectively. The results of this study will establish whether protein kinase-C, MAP kinases, eNOS/iNOS/NO are involved in VEGF and/or receptors (FIk-1/FIt-1) mediated myocardial regulation of HP induced remodeling in rat MI model. The results will provide new information required for new therapeutic strategies to protect the heart in patients with cardiac stress or coronary heart disease.

描述（由申请人提供）：在心肌梗塞（MI）之后，有一种进行性心肌重塑，其特征是左心室（LV）扩张，收缩功能障碍，心肌肥大和基质蛋白的形成增加。 拟议的项目将通过研究转录和蛋白质水平的心脏保护参数来检查缺氧预处理（HP）的分子机制（HP） - 在梗塞心脏中介导的心肌重塑。 我们已经在大鼠MI模型（10％O2/90％NS）中建立了最佳的低氧预处理刺激，以启动毛细血管/小动脉形成，增加的血液流量和心肌心室功能。 为了确定这种HP在增强心室重塑的信号转导过程中的作用，我们将检查（i）VEGF及其酪氨酸激酶受体VEGFR1（FLT-1）（FLT-1）和VEGFR2（FIK-1）（FIK-1）（FIK-1）的表达，蛋白质激酶C的表达和活性与蛋白质激酶C的表达相同，MAP激酶I（II）的表达将是II（II）的表达，II（II）的表达是Inos/IS的活性。 NFKB，STAT1-AIM 2（iii）内皮细胞（EC）生存的程度以及坏死/凋亡的程度，抗凋亡蛋白Bcl-2，survivin表达，PI-3-激酶活性，PI-3-激酶活性以及Akt/Bad Phosphorylation-aim 3。重塑几个月。 FIK-1，INOS和eNOS在VEGF介导的信号传导中的强制性作用将通过使用FLK1，Inos - / - 和eNOS - / - 敲除小鼠来确定心肌发生/重塑。 BRDU掺入分析，心肌细胞和内皮细胞凋亡将研究内皮细胞增殖，将通过双抗体染色，毛细管和小动脉密度来研究，通过使用抗RAT CD31和抗抗抗糖CD31和抗抗肌肉的肌肉素来确定内皮细胞和平滑肌肉细胞。 这项研究的结果将确定蛋白激酶-C，MAP激酶，eNOS/iNOS/NO是否参与VEGF和/或受体（FIK-1/FIT-1）介导的HP诱导的大鼠MI模型重塑的心肌调节。 结果将提供新的治疗策略所需的新信息，以保护心脏应激或冠心病患者的心脏。