Cell Death in Alcoholic Heart and Muscle

描述（由申请人提供）：三分之一的酒精滥用者表现为心脏收缩力和肌肉力量下降，分别称为酒精性心肌病和肌病，在美国约有600万人。事实上，心肌病合并充血性心力衰竭最常见的原因是慢性酒精中毒。然而，这些疾病的发病机制仍然不清楚。对人类酗酒者和动物模型的研究表明，慢性乙醇消耗会增加氧化应激和其他细胞应激因子，并增加细胞凋亡的易感性。除了我们证明酒精患者的人体骨骼肌和心脏细胞凋亡率显著增加外，我们还证明了酒精喂养动物的心脏功能下降。我们的初步数据表明，乙醇也会干扰培养的骨骼肌卫星细胞和其他干细胞的增殖和分化。这些发现表明，乙醇诱导的对凋亡/坏死的敏化可能改变细胞存活和死亡之间微妙的细胞平衡。我们假设慢性酒精滥用使心脏和肌肉对Ca2+超载和Bid引起的线粒体凋亡敏感，至少部分是通过增强氧化/亚硝化应激引起的。我们提出慢性酒精滥用也影响骨骼肌中祖细胞介导的更新，骨骼肌是一个具有强大再生能力的器官。因此，我们提出细胞死亡和更新之间的平衡受损是酒精性心肌病和骨骼肌病发展的核心。本应用程序的目的是1)评估人类酗酒者和喂食乙醇的大鼠心脏和骨骼肌的应激反应标志物和凋亡/坏死，重点是线粒体应激途径；2)将这些参数与酒精组织损伤程度联系起来；3)确定乙醇对骨骼肌祖细胞数量、增殖和分化的影响。我们已经收集了来自西班牙巴塞罗那医院诊所使用生命支持系统的患者的精确注释的人类心脏和骨骼肌组织，并继续获得额外的标本。我们还与NIAAA氧化应激和组织损伤部门主任Pacher博士建立了富有成效的合作关系，Pacher博士是心血管系统氧化/亚硝化应激研究的领导者。因此，pi在钙和Bcl-2家族蛋白介导的线粒体应激以及人类酒精性心肌病和肌病的病理方面的经验将被氧化/亚硝酸盐应激方面的专业知识和独特的人体组织资源所补充。此外，研究将采用高分辨率、高容量和半自动荧光成像的最新进展。我们期望这些研究的结果将在动物模型和人类酗酒者中酒精诱导的组织损伤机制之间提供一个独特的桥梁，并将阐明酒精性心肌病和肌病的发病机制。

DESCRIPTION (provided by applicant): One third of alcohol abusers manifest decreased cardiac contractility and muscle strength termed respectively alcoholic cardiomyopathy and myopathy, accounting for about 6 million persons in the US. In fact, the most common cause of cardiomyopathy with congestive heart failure is chronic alcoholism. However, the pathogenesis of these conditions still remains obscure. Studies in human alcoholics and animal models have demonstrated that chronic ethanol consumption increases oxidative stress and other cellular stress factors and enhances the susceptibility to apoptosis. In addition to our demonstration of a marked increase in the rate of apoptosis in human skeletal muscle and heart from alcoholic patients, we have also shown decreased cardiac function in alcohol-fed animals. Our preliminary data indicate that ethanol also interferes with the proliferation and differentiation o skeletal muscle satellite cells and other stem cells in culture. These findings suggest that ethanol-induced sensitization to apoptosis/necrosis may alter the delicate cellular equilibrium between survival and cell death. We hypothesize that chronic alcohol abuse sensitizes heart and muscle to mitochondrial apoptosis elicited by Ca2+ overload and Bid at least in part by enhancing oxidative/nitrosative stress. We propose that chronic alcohol abuse also affects renewal mediated by progenitor cells in skeletal muscle, an organ that has a robust capacity for regeneration. Thus we propose that an impaired balance between cell death and renewal are central to the development of alcoholic cardiomyopathy and skeletal myopathy. The aims of this application are to i) evaluate stress response markers and apoptosis/necrosis in heart and skeletal muscle from human alcoholics and rats fed ethanol, with an emphasis on the mitochondrial stress pathways and ii) relate these parameters to the degree of alcoholic tissue injury, and iii) determine the effects of ethanol on progenitor cell number, proliferation and differentiation in skeletal muscle. We have available a collection of precisely annotated human heart and skeletal muscle tissues derived from patients on life support systems at the Hospital Clinic in Barcelona, Spain, and continue to obtain additional specimens. We have also established a productive collaboration with Dr. Pacher, the Chief of the Oxidative Stress and Tissue Injury Unit at NIAAA, who is a leader in research of oxidative/nitrosative stress in the cardiovascular system. Thus, the PIs' experience in calcium and Bcl-2 family protein-mediated mitochondrial stress and the pathologic aspects of human alcoholic cardiomyopathy and myopathy will be complemented by expertise in oxidative/nitrosative stress and by access to a unique human tissue resource. Furthermore, the studies will employ the recent advances in high resolution, high capacity and semi-automatic fluorescence imaging. We expect that the results of these studies will provide a unique bridge between the mechanisms underlying alcohol-induced tissue injury in animal models and in human alcoholics and will shed light on the pathogenesis of alcoholic cardiomyopathy and myopathy.