The long-term objective of this project is to detect a novel biomarker (or confined set of biomarkers) of heavy/abusive alcohol consumption in the plasma of human subjects. The working hypothesis for this aim is that alcohol consumption at high levels elicits cellular and molecular responses whose sequelae are manifest through the appearance of unique and low-abundance polypeptides or proteins in the plasma. These molecules may be derived from a variety of tissues and cells and are unrelated to conventional/traditional markers of alcohol-induced liver injury. We hypothesize that low abundance peptide and low molecular weight protein biomarkers are to be found complexed with high-abundance plasma proteins such as albumin. Our strategy is to preferentially recover these potential biomarkers by plasma albumin affinitycapture, elute and concentrate them, and then acquire whole peptide/protein mass spectra of the mixture. ? ? Raw spectral data will then be analyzed, comparing control plasma with samples from alcohol drinkers, and drinkers during early abstinence. Diagnostic peptide/protein patterns will be sought based on various patient classifications. In this regard, our specific aims are to: 1) determine the effect of a defined exposure to alcohol in normal individuals on the plasma proteome, using alcohol clamping to minimize the between-individual variation in alcohol absorption and pharmacokinetics; 2) determine the effect of sustained abusive drinking on the plasma proteome. The subjects will be recruited from patients seeking treatment for alcohol abuse and dependence, and plasma will be sampled at beginning and end of a 6 week intensive outpatient treatment; and 3) determine which proteomic signatures are influenced by patient characteristics such as body mass index, gender, ethnicity, and minor liver test abnormalities. ? ? ?
