Band intensities were quantified using ImageQuant software (Molecular Dynamics)

and standardized against β-actin. DNA was isolated from each liver sample (Qiagen, Valencia, CA) for assay of global DNA methylation by liquid chromatography tandem mass spectrometry,24 which measures the percentage of methylated dCyt in the DNA sample. Chromatin immunoprecipitation (ChIP) assays were performed following a tissue protocol.25 Briefly, 50 mg of liver tissues were cut in small pieces with a razor blade, cross-linked in 1.5% formaldehyde for 15 minutes, processed in a Medimachine (BD Biosciences) using a 50-μm medicon to produce a liver cell suspension. Nuclear extracts were prepared and sonicated using a Bioruptor Sonicator (Diagenode) and precleared using blocked Staphylococcus A cells. Ten percent see more of original precleared chromatin was removed for use as a control for total input DNA. In ChIP analyses, the antibody to the methylated histone immunoprecipitates and isolates

the DNA/histone complex. Using selective and region-specific primers, subsequent PCR determines the extent of trimethylated histone binding to the promoter region of each relevant gene. Each ChIP assay was performed using 500 ng of chromatin and MAPK inhibitor 2 μL of antibody. The primary antibody was rabbit polyclonal 3meH3K9 IgGs (Abcam, catalog # ab8898). Secondary rabbit anti-mouse IgG was purchased from MP Biomedicals (catalog # 55436). Nonspecific rabbit IgG was used as a negative control for the ChIP assays (Alpha Diagnostics, catalog # 20009-5). For PCR analysis of the ChIP samples, purified immunoprecipitates (QIAquick PCR purification kit, Qiagen) were dissolved in 20 μL of water. ChIP-enriched samples and inputs were analyzed in triplicate by way of PCR using primer sequences medchemexpress of promoter regions of GRP78, GADD153, SREBP-1c, and glyceraldehyde 3-phosphate dehydrogenase, as shown in Supporting Table 2S. PCR products were separated by electrophoresis through 1.5% agarose gels, visualized using ethidium bromide, and quantitated with ImageQuant Software

(Molecular Dynamics). Data were normalized with input control. Significant differences between groups were determined by two-way analysis of variance. Statistical significance was assessed at P < 0.05 to determine the effects of ethanol feeding and genotype. Relationships among variables were determined by linear regression analyses of individual values using SPSS data editor 14.0 for Windows (SPSS, Inc., Chicago, IL). Four weeks of intragastric ethanol feeding increased liver/body weight ratios in both ethanol-fed groups with an interaction of ethanol and genotype in the heterozygous (Het-E) group (Table 1). Terminal plasma ethanol levels were elevated more than 40-fold, and ALT levels were elevated more than 10-fold in both ethanol-fed groups, consistent with previous studies.