Changes in the hepatic gene expression profile in a rat model of chronic ethanol treatment

The purpose of this study was to perform a comprehensive analysis of hepatic gene expression in a standard model of an alcohol-induced fatty liver using the cDNA microarray analysis. Male Sprague-Dawley rats were randomly divided into two groups and were given either an ethanol diet (ED), or a control diet (CD) for eight weeks. The ED rats showed significantly elevated levels of plasma total and HDL cholesterol as well as hepatic cholesterol and triglyceride compared to the pair-fed control rats. Among the 5185 genes on the rat cDNA microarray used in the current study, 74 genes were up-regulated and 108 genes were down-regulated greater than 2.0-fold in the liver of ED rats compared with those in the CD rats. The microarray results were verified by conducting real-time RT-PCR on the fourteen selected genes with varied expression ratios. After clustering the regulated genes based on their biological function, it was found that chronic ethanol consumption regulated mainly the genes implicated in the processes of signal transduction, transcription, immune response, and protein/amino acid metabolism. The microarray results obtained in this study revealed, for the first time, that several genes, including beta-glucuronidase, UDP-glycosyltransferase 1, UDP-glucose dehydrogenase, apoC-III, and gonadotropin-releasing hormone receptor, were regulated by chronic ethanol exposure in the rat liver.