Project description:The NADPH-cytochrome P450 reductase (CPR) is essential for the functioning of microsomal cytochrome P450 (P450) monoxygenases. The biological functions of the CPR-dependent enzymes in the intestine are not known, despite the vast knowledge available on the biochemical properties of the various oxygenases. A mouse model with intestinal epithelium (IE)-specific Cpr-knockout (IE-Cpr-null) was recently generated in this laboratory (Zhang et al., Drug Metab. Dispos., 37, 651-657, 2009). The IE-Cpr-null mice did not display any obvious abnormalities in growth, development, or reproduction, and their intestines appeared to have a normal structure. Despite the absence of observable phenotypes, we hypothesized that loss of the enterocyte CPR expression will impact homeostasis of endogenous compounds, and expression of genes, that have critical biological function in the small intestine. In the present study, we have performed genomic analyses for enterocytes from IE-Cpr-null mice and their wild-type littermates, using Affymetrix Mouse Expression Set 430A 2.0 GeneChip Arrays. Our aim was to identify small intestinal gene-expression changes, which may shed light on potential biological roles of CPR and CPR-dependent enzymes in the small intestine. Our analysis revealed significant expression increases in P450s, transporters, cholesterol biosynthesis, and (unexpectedly) antigen presentation/processing. Further genomic and biochemical analyses revealed potential mechanisms linking CPR-dependent enzymes and the expression of major histocompatibility complex class II genes in the small intestine.
Project description:The NADPH-cytochrome P450 reductase (CPR) is essential for the functioning of microsomal cytochrome P450 (P450) monoxygenases. The biological functions of the CPR-dependent enzymes in the intestine are not known, despite the vast knowledge available on the biochemical properties of the various oxygenases. A mouse model with intestinal epithelium (IE)-specific Cpr-knockout (IE-Cpr-null) was recently generated in this laboratory (Zhang et al., Drug Metab. Dispos., 37, 651-657, 2009). The IE-Cpr-null mice did not display any obvious abnormalities in growth, development, or reproduction, and their intestines appeared to have a normal structure. Despite the absence of observable phenotypes, we hypothesized that loss of the enterocyte CPR expression will impact homeostasis of endogenous compounds, and expression of genes, that have critical biological function in the small intestine. In the present study, we have performed genomic analyses for enterocytes from IE-Cpr-null mice and their wild-type littermates, using Affymetrix Mouse Expression Set 430A 2.0 GeneChip Arrays. Our aim was to identify small intestinal gene-expression changes, which may shed light on potential biological roles of CPR and CPR-dependent enzymes in the small intestine. Our analysis revealed significant expression increases in P450s, transporters, cholesterol biosynthesis, and (unexpectedly) antigen presentation/processing. Further genomic and biochemical analyses revealed potential mechanisms linking CPR-dependent enzymes and the expression of major histocompatibility complex class II genes in the small intestine. Adult (2.5-3.0 month-old) male IE-Cpr-null and WT litermates were used for all experiments. RNA was collected from eight mice of each genotype and RNA from two mice of the same genotype was pooled prior to hybridization to the microarray to create a total of four samples for each genotype.
Project description:The ketogenic diet has been successful in promoting weight loss among patients that have struggled with weight gain. This is due to the cellular switch in metabolism that utilizes liver-derived ketone bodies for the primary energy source rather than glucose. Fatty acid transport protein 2 (FATP2) is highly expressed in liver, small intestine, and kidney where it functions in both the transport of exogenous long chain fatty acids (LCFA) and in the activation to CoA thioesters of very long chain fatty acids (VLCFA). We have completed a multi-omic study of FATP2-null (Fatp2-/-) mice maintained on a ketogenic diet (KD) or paired control diet (CD), with and without a 24-hour fast (KD-fasted and CD-fasted) to address the impact of deleting FATP2 under high-stress conditions. Control (wt/wt) and Fatp2-/- mice were maintained on their respective diets for 4-weeks. Afterwards, half the population was sacrificed while the remaining were fasted for 24-hours prior to sacrifice. We then performed paired-end RNA-sequencing on the whole liver tissue to investigate differential gene expression. The differentially expressed genes mapped to ontologies such as the metabolism of amino acids and derivatives, fatty acid metabolism, protein localization, and components of the immune system’s complement cascade, and were supported by the proteome and histological staining.
Project description:We created mice, which are deficient for Myc specifically in cardiac myocytes by crossing crossed Myc-floxed mice (Mycfl/fl) and MLC-2VCre/+ mice. Serial analysis of earlier stages of gestation revealed that Myc-deficient mice died prematurely at E13.5-14.5. Morphological analyses of E13.5 Myc-null embryos showed normal ventricular size and structure; however, decreased cardiac myocyte proliferation and increased apoptosis was observed. BrdU incorporation rates were also decreased significantly in Myc-null myocardium. Myc-null mice displayed a 3.67-fold increase in apoptotic cardiomyocytes by TUNEL assay. We examined global gene expression using oligonucleotide microarrays. Numerous genes involved in mitochondrial death pathways were dysregulated including Bnip3L and Birc2. Keywords: wildtype vs Myc-null
Project description:NADPH-cytochrome P450 reductase (CPR) is important for the functions of many enzymes, such as microsomal cytochrome P450 (P450) monooxygenases and heme oxygenases. Two mouse models with deficient CPR expression in adults were recently generated in this laboratory: liver-Cpr-null (with liver-specific Cpr deletion) (Gu et al., J. Biol. Chem., 278, 25895–25901, 2003) and Cpr-low (with reduced CPR expression in all organs examined) (Wu et al. J. Pharmacol. Expt. Ther. 312, 35-43, 2005). The phenotypes included a reduced serum cholesterol level and an induction of hepatic P450 in both models, and hepatomegaly and fatty liver in the liver-Cpr-null mouse alone. Our aim was to identify hepatic gene-expression changes related to these phenotypes. Cpr-lox mice, which have normal CPR expression (Wu et al., Genesis, 36, 177-181, 2003.), were used as the control in microarray analysis. A detailed analysis of the gene-expression changes in lipid metabolism and transport pathways revealed potential mechanisms, such as an increased activation of constitutive androstane receptor (CAR) and a decreased activation of peroxisomal proliferators activated receptor alpha (PPAR-gamma) by precursors of cholesterol biosynthesis, that underlie common changes (e.g., induction of multiple P450s and inhibition of genes for fatty acids metabolism) in response to CPR-loss in the two mouse models. Moreover, we also uncovered model-specific gene-expression changes, such as the induction of a lipid translocase (CD36 antigen) and the suppression of carnitine O-palmitoyltransferase 1 (CPT1a) and acyl-CoA synthetase long-chain family member 1 (Acsl1), that are potentially responsible for the severe hepatic lipidosis observed in liver-Cpr-null, but not Cpr-low mice. Keywords = Cytochrome P450 Keywords = NADPH-cytochrome P450 reductase Keywords = transgenic mice Keywords = liver Keywords = nuclear receptor Keywords: other
Project description:Genome wide expression profiling to determine the overlap of Affymetrix-signals with SOLID sequencing RNA was extracted using the Qiagen RNeasy kit following the manufacturers guidelines, arrays were prepared and hybridized following the Affymetrix protocol. Mus musculus samples from small intestine and colon, to be compared to transcript data aquired with other techniques
Project description:Fatty acid transport protein 2 (FATP2) is highly expressed in liver, small intestine, and kidney where it functions in both the uptake of exogenous long chain fatty acids (LCFAs) and in the activation to CoA thioesters of very long chain fatty acids (VLCFAs). Here we address the phenotypic impacts of deleting FATP2 followed by an unbiased RNA-seq analysis of the liver transcriptome. Wild type (C57BL/6J) and fatp2 null (fatp2-/-) mice (5 weeks old) were maintained on a standard chow diet for 6 weeks (11 weeks old). The male fatp2-/- mice had 258 differentially expressed genes (DEGs) and the female mice had a total of 91. Of significance was the finding that most of the genes with increased expression in the fatp2-/- liver are regulated by the transcription factor peroxisome proliferator-activated receptor alpha (PPARα). Taken together, FATP2 has a broad impact on the expression of key lipid metabolic genes in the liver regulated by PPARα.