Identification and Validation of Alcohol Biomarker Signatures by Proteomics

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DESCRIPTION (provided by applicant): One third of chronic alcohol abusers display cardiac dysfunction, leading to dilated cardiomyopathy and eventually to congestive heart failure. Functionally, alcoholic cardiomyopathy (ACM) is characterized by reversible and irreversible alterations. Alcoholism also causes atrophy of skeletal muscle, termed alcoholic myopathy, which is closely correlated with ACM. Skeletal muscle weakness progresses in parallel with depression of the left ventricle ejection fraction. A chronic effect of alcohol on the structure and function of the muscles has been shown to induce changes in several proteins and pathways. The goal of this grant application is to identify reliable diagnostic and prognostic protein biomarkers of ACM in humans. The specific aims of this application are i) to identify early onset ACM-related protein biomarkers in heart and serum of rats fed alcohol chronically. Since in humans, the deltoid muscle may serve at least in part, as a surrogate for cardiac tissue, ii) to study protein expression in muscle biopsies and serum of chronic alcoholics with clinical ACM and myopathy and compare it to asymptomatic alcoholics and nonalcoholic controls. A unique heart tissue bank, from irreversibly brain damaged alcoholic patients whose hearts could not be transplanted and were frozen after termination of life support, will be investigated, iii) To discover ACM protein biomarkers by comparing protein profiles of the left ventricle of chronic alcoholics with and without ACM, and nonalcoholic controls. Additionally, corresponding muscle and serum samples from the same subjects will be evaluated for biomarkers. iv) To perform biostatistical and bioinformatics data mining for differential analysis of proteomic expression from rat and human samples, correlate global protein changes with clinical data to obtain disease-specific protein patterns for validation, integrate data in a relational database for future comparative studies with other cardiomyopathies, and map clusters of protein changes in affected pathways of the protein interactome in order to develop a mechanistic model of the pathogenesis of ACM and myopathy. v) To validate the specificity, accuracy and usefulness of emergent proteomic panels of biomarkers in new serum and muscle samples that will lead to clinical context validation and application of ACM biomarkers. The comprehensive search and discovery of protein biomarkers of ACM will encompass the proteomes of sera, and of subcellular components of tissues. A combination of 2D electrophoresis with multidimensional liquid chromatography and tandem mass spectroscopy will be employed to characterize protein changes, as well as, post-translational protein modifications, including those directly related to alcohol metabolites. Immunoassays will be also developed for validation purposes. There are 18 million alcohol abusers in the US. Many of these persons suffer from alcoholic cardiomyopathy, which is the single leading cause of dilated cardiomyopathy in which an etiology can be determined. Early diagnosis of this condition by specific biomarkers will offer the opportunity for treatment and prevention of heart enlargement, congestive heart failure and death.