Project description:Human cardiomyopathies often lead to heart failure, a major cause of morbidity and mortality in industrialized nations. Described here is a phenotypic characterization of cardiac function and genome-wide expression from C3H/HeJ, C57BL/6J, and B6C3F1/J male mice. Histopathologic analysis identified a low-grade background cardiomyopathy (murine progressive cardiomyopathy) in eight of nine male C3H/HeJ mice (age nine to ten weeks), but not in male C57BL/6J and in only of ten male B6C3F1/J mice. The C3H/HeJ mouse had an increased heart rate and a shorter RR interval compared to the B6C3F1/J and C57BL/6J mice. Cardiac genomic studies indicated the B6C3F1/J mice exhibited an intermediate gene expression phenotype relative to the 2 parental strains. Disease-centric enrichment analysis indicated a number of cardiomyopathy-associated genes were induced in B6C3F1/J and C3H/HeJ mice, including Myh7, My14, and Lmna and also indicated differential expression of genes associated with metabolic (e.g., Pdk2) and hypoxic stress (e.g. Hif1a). A novel coexpression and integrated pathway network analysis indicated Prkaa2, Pdk2, Rhoj, and Sgcb are likely to play a central role in the pathophysiology of murine progressive cardiomyopathy in C3H/HeJ mice. Our studies indicate that genetically determined baseline differences in cardiac phenotype have the potential to influence the results of cardiotoxicity studies.
Project description:Furan is a mouse and rat hepatocarcinogen. We sought to determine the dose-dependent changes in gene expression upon exposure of B6C3F1 mice to furan in order to better understand furan’s mode of action. In this study we examined the transcriptional response in liver tissue of female B6C3F1 mice to BrdU treatment (in drinking water for 5 days before sacrifice). This was a toxicogenomic study in which mice were also exposed to 0, 1 or 8 mg/kg bw furan (by oral gavage) for 3 weeks. Mice were sacrificed four hours after the final furan exposure. Each dose group had 4-5 biological replicates. We used a two-colour reference design and SurePrint G3 Mouse GE 8x60K microarrays (Agilent). Please note that data for all non-BrdU treated animals was previously reported in GEO [GSE48644]. All samples (with or without BrdU) were part of the same randomized block design for the microarrays.
Project description:Furan is a mouse and rat hepatocarcinogen. We sought to determine the dose-dependent changes in gene expression upon exposure of B6C3F1 mice to furan in order to better understand furan’s mode of action. Adult female B6C3F1 mice were exposed to 1, 2, 4 or 8 mg/kg bw furan or vehicle control (corn oil) for three weeks and sacrificed four hours after the final exposure.
Project description:Ginkgo biloba leaf extract (GBE) is used in traditional Chinese medicine as an herbal supplement for improving memory. Exposure of B6C3F1/N mice to GBE in a 2-year National Toxicology Program (NTP) bioassay resulted in a dose-dependent increase in hepatocellular carcinomas (HCC). To identify key microRNAs that modulate GBE-induced hepatocarcinogenesis, we compared the global miRNA expression profiles in GBE-exposed HCC (GBE-HCC) and spontaneous HCC (SPNT-HCC) with age-matched vehicle control normal livers (CNTL) from B6C3F1/N mice. The number of differentially altered miRNAs in GBE-HCC and SPNT-HCC were 74 (52 up and 22 down) and 33 (15 up and 18 down), respectively. Among the uniquely differentially altered miRNAs in GBE-HCC,, miR-31 was selected for functional validation. A potential miRNA response element (MRE) in the 3’-untranslated regions (3’-UTR) of Cdk1 mRNA was revealed by in silico analysis and confirmed by luciferase assays. In mouse hepatoma cell line HEPA-1 cells, we demonstrated an inverse correlation between miR-31 and CDK1 protein levels, but no change in Cdk1 mRNA levels, suggesting a post-transcriptional effect. Additionally, miRNA expression analysis in non-tumor liver samples from the 90-day GBE mouse study demonstrated an upregulation of miRs-411, 300, 127, 134, 409-3p, and 433-3p in GBE-exposed group compared to vehicle control group, indicating that some of these miRNAs could serve as potential biomarkers for GBE exposure or hepatocellular carcinogenesis. These data increase our understanding of miRNA-mediated epigenetic regulation of GBE-mediated hepatocellular carcinogenesis in B6C3F1/N mice.
