Proteomics Reveal a Concerted Upregulation of Methionine Metabolic Pathway Enzymes, and Downregulation of Carbonic Anhydrase-III, in Betaine Supplemented Ethanol-Fed Rats

Authors

Kusum K. Kharbanda, University of Nebraska Medical CenterFollow
Vasanthy Vigneswara, School of Biomedical Sciences, University of Nottingham, Queen’s Medical Centre, Nottingham NG7 2UH, UK
Benita L. McVicker, Department of Internal Medicine, University of Nebraska Medical Centre, Omaha, NE 68198, USA
Anna U. Newlaczyl, School of Biomedical Sciences, University of Nottingham, Queen’s Medical Centre, Nottingham NG7 2UH, UK
Kevin Bailey, School of Biomedical Sciences, University of Nottingham, Queen’s Medical Centre, Nottingham NG7 2UH, UK
Dean Tuma, Department of Internal Medicine, University of Nebraska Medical Centre, Omaha, NE 68198, USA
David E. Ray, School of Biomedical Sciences, University of Nottingham, Queen’s Medical Centre, Nottingham NG7 2UH, UK
Wayne G. Carter, School of Biomedical Sciences, University of Nottingham, Queen’s Medical Centre, Nottingham NG7 2UH, UK

Date of this Version

2009

Comments

Published in Biochemical and Biophysical Research Communications 381 (2009) 523–527.

Abstract

We employed a proteomic profiling strategy to examine the effects of ethanol and betaine diet supplementation on major liver protein level changes. Male Wistar rats were fed control, ethanol or betaine supplemented diets for 4 weeks. Livers were removed and liver cytosolic proteins resolved by onedimensional and two-dimensional separation techniques. Significant upregulation of betaine homocysteine methyltransferase-1, methionine adenosyl transferase-1, and glycine N-methyltransferase were the most visually prominent protein changes observed in livers of rats fed the betaine supplemented ethanol diet. We hypothesise that this concerted upregulation of these methionine metabolic pathway enzymes is the protective mechanism by which betaine restores a normal metabolic ratio of liver S-adenosylmethionine to S-adenosylhomocysteine. Ethanol also induced significant downregulation of carbonic anhydrase- III protein levels which was not restored by betaine supplementation. Carbonic anhydrase-III can function to resist oxidative stress, and we therefore hypothesise that carbonic anhydrase-III protein levels compromised by ethanol consumption, contribute to ethanol-induced redox stress.