Gene array profiles of alcohol and aldehyde metabolizing enzymes in brains of C57BL/6 and DBA/2 mice.
BACKGROUND
Differences in ethanol metabolizing enzymes expressed in brain have been suggested to contribute to the significant differences in ethanol (alcohol) preference between inbred C57BL/6 and DBA/2 mouse strains.


METHODS
We have utilized 2 different platforms of oligonucleotide microarray technology (CodeLink UniSet I BioArray from G.E. Healthcare and MG U74A v2.0 from Affymetrix) to simultaneously assess expression of alcohol and acetaldehyde metabolizing enzymes in the whole brain of naïve (no exposure to alcohol) C57BL/6 and DBA/2 mice.


RESULTS
There were no significant differences between the 2 strains of mice in gene expression intensity for alcohol dehydrogenases (ADH), catalase, and a number of the cytochrome P450 family of genes, which can be involved in ethanol catabolism. However, significantly higher expression of mRNA for aldehyde dehydrogenase 2 (ALDH2), an isoform mainly responsible for the catabolism of acetaldehyde, was observed in whole brains of DBA/2 mice with both platforms. Aldehyde dehydrogenase 2 protein was also higher in DBA/2 brain. Expression of aldehyde dehydrogenase 1A1 (ALDH1A1) mRNA was found to be higher in brains of DBA/2 mice, when measured with the CodeLink platform, but not when measured with Affymetrix arrays or quantitative reverse transcriptase-real-time polymerase chain reaction (qRT-PCR). The ALDH1A1 protein, however, reflected the results obtained with the CodeLink arrays and was higher in DBA/2 brain, compared with brains of C57BL/6 mice. In contrast, the expression intensity for the aldehyde dehydrogenase 7A1 (ALDH7A1) mRNA and protein was significantly higher in C57BL/6 mice than DBA/2 mice. These expression differences are consistent with more rapid metabolism of acetaldehyde in brains of DBA/2 mice.


CONCLUSIONS
The use of 2 different microarray platforms provides important cross-validation of many results, and some discrepancies can be resolved with qRT-PCR and immunoblotting. The expression differences that were validated may affect alcohol/aldehyde metabolism in brain and/or alcohol preference in the 2 strains of mice.
Bhave
Sanjiv V
SV
Department of Pharmacology, University of Colorado at Denver and Health Sciences Center, Aurora, Colorado 80045-0511, USA.
Hoffman
Paula L
PL
Lassen
Natalie
N
Vasiliou
Vasilis
V
Saba
Laura
L
Deitrich
Richard A
RA
Tabakoff
Boris
B
D000079:Acetaldehyde / Q000378:metabolism; D000426:Alcohol Dehydrogenase / Q000235:genetics* / Q000378:metabolism; D000444:Aldehyde Dehydrogenase / Q000235:genetics* / Q000378:metabolism; D000080924:Aldehyde Dehydrogenase 1 Family; D000071396:Aldehyde Dehydrogenase, Mitochondrial; D000447:Aldehydes / Q000378:metabolism; D000818:Animals; D001921:Brain / Q000201:enzymology*; D002374:Catalase / Q000235:genetics* / Q000378:metabolism; D002492:Central Nervous System Depressants / Q000378:metabolism; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics* / Q000378:metabolism; D000431:Ethanol / Q000378:metabolism; D020869:Gene Expression Profiling; D015971:Gene Expression Regulation, Enzymologic; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D020411:Oligonucleotide Array Sequence Analysis; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D050697:Retinal Dehydrogenase
D000447:Aldehydes; D002492:Central Nervous System Depressants; D012333:RNA, Messenger; D000431:Ethanol; D003577:Cytochrome P-450 Enzyme System; D000426:Alcohol Dehydrogenase; D002374:Catalase; D000080924:Aldehyde Dehydrogenase 1 Family; C515029:ALDH2 protein, mouse; D000444:Aldehyde Dehydrogenase; D000071396:Aldehyde Dehydrogenase, Mitochondrial; C515028:ALDH1A1 protein, mouse; D050697:Retinal Dehydrogenase; D000079:Acetaldehyde