SCOR IN HEART FAILURE

这一竞争性的更新包括六项合作调查， 在四个综合核心设施的支持下， 心脏病的病因、发病机制和治疗的基础 失败这些研究的重点是试图解开分子 在两种情况下，心脏生长、肥大和衰竭的潜在机制 获得性和遗传性疾病。 在项目1-2中，我们将调查 肥厚型心肌病（HCM）和肌强直的分子基础 营养不良（DM）。具有三种已知β-肌球蛋白的互补DNA构建体 重链（β-MHC）突变将通过E1缺陷型 腺病毒在猫心肌细胞中并包装成小基因用于体内 在转基因兔中的表达。心脏结构和功能将 通过超声心动图和随后的光散射在体内连续评估 和电子显微镜来阐明β MHC 突变。在项目2中，利用酵母相互作用克隆和 固定化重组肌紧张素蛋白激酶（MtPK）作为亲和 基质，MtPK的底物将被确定为第一步， 鉴定磷酸化级联反应中的缺陷 对于DM。在项目1和项目2的其他研究中， 将进行分析，以确定这两种疾病的新基因， 与已建立的基因座相连。 在项目3中，使用非常大的 家族性扩张型心肌病（DCM）家系（>400），连锁 分析和定位克隆将被用来鉴定 负责任的基因 在项目4中，TGF β 1在 将使用新的显性- 成年心室肌细胞中TGF β受体的负突变体， 使用腺病毒基因转移和在转基因的完整心肌中 小鼠在项目5中，研究了P55的野生型和显性阴性突变体， P75 TNF α受体将通过腺病毒在成人中表达 心室肌细胞，以确定TNF α受体的形式 导致收缩力下降受体的可溶形式 将作为TNF α抑制剂给予，试图改善心脏 功能衰竭患者，并评估内源性 体内TNF α。 在项目6中，将进行研究，以确定 胰岛素样生长因子-I（IGF-1）在心脏生长中作用 肥大，利用过表达IGF-1或其结合的转基因小鼠 蛋白 腺病毒基因转移和显性失活突变 假定的IGF信号蛋白将用于鉴定 负责的细胞质转换器和转录因子， 胰岛素样生长因子对心肌肥厚的影响。这六项研究 应该提供重要的新见解的分子基础， 心脏肥大和衰竭，并有助于合理的基础， 更有效的治疗。

This competing renewal encompasses six collaborative investigations, supported by four integrated core facilities, to address issues fundamental to the etiology, pathogenesis and treatment of cardiac failure. The studies are focused on an attempt to unravel molecular mechanisms underlying cardiac growth, hypertrophy and failure in both acquired and inherited disorders. In Projects 1-2, we will investigate the molecular basis for hypertrophic cardiomyopathy (HCM) and myotonic dystrophy (DM). Complementary DNA constructs with three known beta-myosin heavy chain (betaMHC) mutations will be expressed via E1-deficient adenovirus in feline cardiocytes and packaged into minigenes for in vivo expression in the transgenic rabbit. Cardiac structure and function will be assessed serially in vivo by echocardiography and subsequently by light and electron microscopy to elucidate the consequences of beta MHC mutations. In Project 2, utilizing yeast interaction cloning and immobilized recombinant myotonin protein kinase (MtPK) as an affinity matrix, substrates for MtPK will be identified as an initial step toward identifying the defect in the phosphorylation cascade presumed responsible for DM. In other studies of Projects 1 and 2, large informative pedigrees will be analyzed to identify novel genes for both diseases in families not linked to established loci. In Project 3, using an exceptionally large pedigree (>400) with familial dilated cardiomyopathy (DCM), linkage analysis and positional cloning will be employed to identify the responsible gene. In Project 4, the postulated role of TGFbeta1 in cardiac hypertrophy will be assessed with the use of novel dominant- negative mutants of the TGFbeta receptor in adult ventricular myocytes, using adenoviral gene transfer and in the intact myocardium in transgenic mice. In Project 5, wild-type and dominant-negative mutants of the P55 and P75 TNFalpha receptor will be expressed via adenovirus in adult ventricular myocytes to determine the form of TNFalpha receptor responsible for depressed contractility. A soluble form of the receptor will be given as a TNFalpha inhibitor in an attempt to improve cardiac function in patients with failure and evaluate the role of endogenous TNFalpha in vivo. In Project 6, studies will be performed to determine the role of insulin-like growth factor-I (IGF-l) in cardiac growth and hypertrophy, utilizing transgenic mice overexpressing IGF-l or its binding protein. Adenoviral gene transfer and dominant-negative mutations of postulated IGF signalling proteins will be used to identify the responsible cytoplasmic transducers and transcription factors that mediate the effect of IGF on cardiac hypertrophy. Together, these six studies should provide significant new insights into the molecular foundations of cardiac hypertrophy and failure and contribute to a rational basis for more effective therapy.