Alcohol-induced liver damage and disease is an important health problem At least three enzyme activities in liver are capable of converting ethanol to acetaldehyde, alcohol dehydrogenase (ADH), cytochrome P450 2E1 (CYP2E1), and catalase Although CYP2E1 is inducible by chronic alcohol exposure, results using naturally occurring and induced ADH-deficient animals suggest class I ADH plays a major role in ethanol metabolism and class IV plays a significant role. Class I ADH is expressed at high levels in the liver of mammals A single gene, Adh1, encodes class I ADH in mice while three genes, ADH1A, ADH1B and ADH1C, encode class I polypeptides in humans The overall goals are to identify distal genomic dements that control the expression phenotype of members of the mouse Adh complex, and to genetically manipulate by gene copy-number the ratio of ADH1/CYP2E1 in liver to explore the role of this ratio in alcohol-induced liver damage Distal cis-linked sequence in a BAC clone will direct expression of Adh1 in liver and Adh4 in stomach No sequence directing liver expression of any human class I ADH gene is known. Genetic approaches will define the important distal control element(s) for the Adh1 gene, and construct and use mouse strains on a constant C57BL/6 background with varying ADH1/CYP2E1 ratios to explore the role of each in alcohol induced liver injury The specific aims are (1) experimentally delineate the location of the distal sequence(s) controlling expression of Adh1 in liver, intestine and adrenal using transgenic expression assays, (2) determine if chromatin alterations occur in the expressed Adh1 region, (3) generally define the cis-linked sequence that promotes Adh4 proper expression phenotype, (4) genetically construct mouse strains (a) having ADH1/CYP2E1 ratio varying 8- fold using available knockouts and transgenics, (b) overexpressing ADH in lung, testes, seminal vesicle, and epididiymis in the absence of ADH in liver (a """"""""conditional knockout""""""""), (c) harboring a human CYP2E1 BAC for overexpression, and (5) explore pathology promoted by ethanol in these genetic strains.
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