Confounding influence of tamoxifen in mouse models of Cre recombinase-induced gene activity or modulation

Liver Systems Medicine : striving to develop non-invasive methods for diagnosing and treating NAFLD by combining mathematical modeling and biological research. LiSyM, is a multidisciplinary research network, in which molecular and cell biologists, clinical researchers, pharmacologists and experts in mathematical modeling examine the liver in its entirety. LiSyM research focuses on the metabolic liver disease non-alcoholic fatty liver disease (NAFLD), which includes non-alcoholic steatohepatitis ...

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Inducible Cre system and fate tracing cells using tamoxifen

Representative NMR spectra of different metabolites across the groups. and c) NMR-based metabolomics heatmaps of liver tissue revealed different patterns upon TAM administration. Red and green colors refer to upregulated and downregulated genes, respectively. The p value indicates the statistical difference between the presented groups (JPG 2849 KB)

Heatmap shows deregulated phase I and phase II metabolic targets as well as transporter () and inflammatory assigned (b) genes as quantified by the Fluidigm platform in TAM/Oil and Veh/Oil-exposed mice. Red and green colors refer to upregulated and downregulated genes, respectively. The p value indicates the statistical difference between TAM/Oil and Veh/Oil groups (JPG 3455 KB)

CYP2E1 activity in HepG2-E47 was measured. TAM inhibits (not significantly) the CYP2E1 activity compared to alcohol and DMSO-treated cells. C34 cell line was used as a negative control. Bars represent the means±SD of 3 biological replica. Student’s t test (paired t test) was used to check the statistical differences upon TAM incubation (JPG 1530 KB)

Protein level of CYP2E1 was analyzed by co-immunofluorescence staining immediately after attachment (3h) and 24 hours later. b and c) Protein and mRNA levels of CYP2E1 were analyzed upon TAM pretreatment. d and e) Protein and mRNA levels of catalase were assessed upon TAM pretreatment. Bars represent the means±SD of 3 mice (JPG 3000 KB)

Formalin-fixed livers were processed and stained with HE, CYP2E1, GS, F4/80 and CD45 to visualize and quantify hepatocellular necrosis, metabolizing enzymes, resident macrophages and recruited immune cells, respectively. Slides were scanned and the signal was randomly quantified in 15 images per liver. Yellow dashed lines indicate the necrotic areas. Yellow arrows refer to the positive signals. Scale bars are 200µm for HE and CYP2E1 and 100µm for GS, F4/80 and CD45 (JPG 6105 KB)