Expression data from mouse livers expressing or lacking Cre recombinase during pneumonia

Cre-recombinase expression under control of an albumin promoter in the presence of floxed alleles is a highly effective and specific way to target gene mutations in hepatocytes. However, some concerns have been raised regarding off-target and/or toxic effects of cre itself, possibly confounding the interpretation of studies employing this approach. We have now used this tool to succesfully target gene deletions in hepatocytes during pneumonia, a condition which results in significant remodeling of the hepatic transcriptome. The goal of this study was to determine what effects, if any, cre expression alone has on hepatic gene expression during bacterial pneumonia. Mutant mice expressed CRE-recombinase under control of an albumin promoter. Results from mutants were compared to wild-type mice on the same genetic background (C57BL/6). Microarray analysis was performed on liver RNA collected from both genotypes of mice in the absence and presence of pneumococcal pneumonia. RNA from 2 separate groups of mice (3 mice per group) was analyzed: 1) Control mice infected intratracheally for 24h with 10^6 CFU of Streptococcus pneumoniae (serotype 3); and 2) Mutant mice infected intratracheally for 24h with 10^6 CFU of Streptococcus pneumoniae (serotype 3).