SAP KINASES IN GQ INDUCED APOPTOTIC HEART FAILURE

GQ 中的 SAP 激酶诱发细胞凋亡性心力衰竭

• 批准号: 6184750
• 负责人: JOAN HELLER BROWN
• 金额: $ 26.51万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-09-30 至 2002-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6184750
• 关键词: G protein; apoptosis; cardiac myocytes; cysteine endopeptidases; genetically modified animals; heart enlargement; heart failure; infant animal; laboratory mouse; laboratory rat; mitogen activated protein kinase; molecular pathology; pathologic process; protease inhibitor; transfection

Heart failure is a prevalent disease affecting millions of American people. The transition from compensated hypertrophy to cardiac failure is often accompanied by apoptotic death of cardiomyocytes but the mechanism and physiological relevance of this phenomenon is not clear. The objective of the proposed studies is to elucidate the signaling pathways responsible for apoptosis in cardiac myocytes and to test their involvement in heart failure. Specifically we will test the hypothesis that members of the stress activated MAP kinase (SAP kinase) cascade, cJun N-terminal kinase (JNK) and p38 kinase, mediate the cardiac hypertrophy and apoptosis induced by increased expression of the alpha subunit of the heterotrimeric G-protein Gq both in vitro and in vivo. The possible involvement of the ICE/caspase family of proteases in the apoptotic response will also be assessed in order to test their potential therapeutic effectiveness in heart failure. The first specific aim utilizes cultured neonatal rat ventricular myocytes as a model system. Myocytes infected with adenoviral vectors expressing wild type or constitutively activated Galphaq manifest features of hypertrophy (increased ANF expression, cell enlargement, myofilament organization) with a progression to apoptotic cell death (chromosomal fragmentation and nuclear condensation). The proposed studies will analyze the sequential development of hypertrophy and apoptosis and its relationship to the strength of Galphaq signaling, the involvement of downstream SAP kinase and the relationship of these responses to caspase activation. The second specific aim utilizes transgenic animals expressing both Galphaq and dominant negative mutant SAP kinase to determine specific roles of the SAPK in Galphaq induced hypertrophy. In the third specific aim, the same group of mice will be experimentally manipulated by transverse aortic banding, infusion of agonists or pregnancy in order to determine the role of SAPKs in the induction of apoptotic heart failure as observed in Galphaq transgenic mice under these experimental manipulations. In the final specific aim, constitutively active upstream activators of JNK and p38, shown to induce hypertrophy and apoptosis in cultured myocytes, will be conditionally expressed in hearts of transgenic mice. Changes in cardiac function and morphology resulting from the expression of the activated upstream activators of SAPK will be analyzed. If apoptosis occurs, caspase inhibitors will be administered to test in vivo their involvement in apoptosis and the relationship of apoptosis to heart failure Overall these studies should contribute to our understanding of the mechanisms by which hypertrophy transitions to heart failure and ultimately to the identification of potentially useful therapies to prevent or reverse the decompensation process.

心力衰竭是一种影响数百万美国人的普遍疾病 人们。 从补偿肥大到心脏衰竭的过渡 通常伴随着心肌细胞的凋亡死亡 这种现象的机制和生理相关性尚不清楚。 拟议研究的目的是阐明信号传导 导致心肌细胞凋亡的途径并测试其 参与心力衰竭。 具体而言，我们将检验假设 应力激活的MAP激酶（SAP激酶）级联反应的成员， CJUN N末端激酶（JNK）和P38激酶，介导心脏 由α表达增加引起的肥大和凋亡 异三聚体G蛋白GQ的亚基在体外和体内。 蛋白酶的冰/caspase家族可能参与 还将评估凋亡反应以测试其 心力衰竭的潜在治疗有效性。 第一个 特定的目标利用培养的新生大鼠心室肌细胞为 模型系统。 用腺病毒载体感染的心肌细胞表达野生 类型或组成型激活的Galphaq明显特征 肥大（增加ANF表达，细胞肿大，肌丝 组织），向凋亡细胞死亡（染色体）进展 分裂和核凝结）。 拟议的研究将 分析肥大和凋亡的顺序发展及其 与Galphaq信号的强度的关系，参与 下游SAP激酶以及这些反应与caspase的关系 激活。 第二个特定目的利用转基因动物 同时表达Galphaq和显性阴性突变体SAP激酶 确定SAPK在Galphaq诱导的肥大中的特定作用。 在第三个特定目的中，同一组小鼠将在实验上进行 通过横向主动脉谱带，激动剂或 怀孕以确定SAPK在诱导中的作用 在Galphaq转基因小鼠中观察到的凋亡心力衰竭 这些实验操作。 在最终的特定目标中， JNK和p38的组成型活动上游激活剂，显示为 在培养的肌细胞中诱导肥大和凋亡，将是 有条件地在转基因小鼠的心脏中表达。心脏变化 激活的表达产生的功能和形态 SAPK的上游激活剂将进行分析。 如果发生凋亡， caspase抑制剂将被施用以在体内测试 参与凋亡和凋亡与心脏的关系 总的来说，这些研究应该有助于我们的理解 肥大过渡到心力衰竭和 最终确定潜在有用的疗法 防止或逆转代偿过程。