CYTOCHROME P4502E1 HYDROXYETHYL RADICAL ADDUCTS AS THE MAJOR ANTIGEN IN AUTOANTIBODY FORMATION AMONG ALCOHOLICS

Citation
P. Clot et al., CYTOCHROME P4502E1 HYDROXYETHYL RADICAL ADDUCTS AS THE MAJOR ANTIGEN IN AUTOANTIBODY FORMATION AMONG ALCOHOLICS, Gastroenterology, 111(1), 1996, pp. 206-216
Citations number
43
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Gastroenterology & Hepatology
Journal title
ISSN journal
0016-5085
Volume
111
Issue
1
Year of publication
1996
Pages
206 - 216
Database
ISI
SICI code
0016-5085(1996)111:1<206:CPHRAA>2.0.ZU;2-5
Abstract
Background & Aims: We have previously reported that alcoholics have in creased titers of immunoglobulins reacting with protein adducts of hyd roxyethyl free radicals. Because hydroxyethyl radicals are produced du ring ethanol metabolism by liver microsomes, the aim of this study was to determine whether such antibodies recognize microsomal proteins co mplexed with hydroxyethyl radicals. Methods: Liver microsomal proteins reacting with the anti-hydroxyethyl radical antibodies were character ized by an enzyme-linked immunosorbent assay and Western blotting. Res ults: Alcoholic cirrhotics, but not patients with nonalcoholic cirrhos is or healthy subjects, had increased serum levels of immunoglobulin G and A directed against antigens produced in microsomes incubated with reduced nicotinamide adenine dinucleotide phosphate (NADPH) and ethan ol. Such immunoreactivity was completely blocked when microsomes were incubated with ethanol in the presence of the spin-trapping agent 4-py ridyl-1-oxide-t-butyl nitrone or by preincubating the sera with hydrox yethyl radical-bound human albumin. Immunoblotting of proteins from hu man liver microsomes incubated with NADPH and ethanol showed that 86% of the sera from alcoholic cirrhotics reacted with a 52-kilodalton pro tein, whereas variable reactivity was observed with proteins of 78, 60 , and 40 kilodaltons, respectively. The 52-kilodalton protein was iden tified by immunoblotting and immunoprecipitation as ethanol-inducible cytochrome P4502E1. Conclusions: Antibodies from alcoholic cirrhotics specifically recognized hydroxyethyl radical-cytochrome P4502E1 adduct s, suggesting the possible implication of these antigens in the develo pment of autoimmune reactions in alcoholic liver disease.