Project description:Gene expression regulation of transporters and phase I/II metabolic enzymes in murine small intestine during fasting Keywords: metabolic state analysis
Project description:This study aimed to quantify and compare the mRNA abundance of all major XPGs in liver and intestine using RNA-Seq. The mRNA profiles of 304 XPGs, including phase-I, phase-II enzymes, phase-II cosubstrate synthetic enzymes, xenobiotic transporters, as well as xenobiotic-related transcription factors, were systematically examined in liver and various sections of the intestine in adult male C57BL/6J mice. By two-way hierarchical clustering, over 80% of the XPGs had tissue-divergent expression, which partitioned into liver-, small intestine-, and large intestine-predominant patterns. Among the genes, 54% were highest expressed in liver, 21% in duodenum, 4% in jejunum, 6% in ileum, and 15% in large intestine. The highest expressed XPG in liver was Mgst1, in duodenum Cyp3a11, in jejunum and ileum Ces2e, and in large intestine Cyp2c55. Interestingly, XPGs in the same family usually exhibited highly different tissue distribution patterns, and many XPGs were almost exclusively expressed in one tissue and minimally expressed in others. In conclusion, the present study is among the first and the most comprehensive investigation of the real mRNA abundance and tissue-divergent expression of all major XPGs in mouse liver and intestine, which aids in understanding the tissue-specific biotransformation and toxicity of drugs and other xenobiotics.
Project description:Gut microbiota are known to influence oral drug disposition, yet the specific host pathways they affect remain poorly characterized. This study provides a transcriptome-wide characterization of how physiological gut microbiota regulate the expression of intestinal transporters, phase I and phase II metabolic enzymes, and barrier machinery relevant to oral drug disposition. By identifying microbiota-responsive processes, this work defines the scope of inter-individual variability attributable to gut microbial effects.
Project description:Background: The selective absorption of nutrients and other food constituents in the small intestine is mediated by a group of transport proteins and metabolic enzymes, often collectively called ‘intestinal barrier proteins’. An important receptor that mediates the effects of dietary lipids on gene expression is the peroxisome proliferator-activated receptor alpha (PPARα), which is abundantly expressed in enterocytes. In this study we examined the effects of acute nutritional activation of PPARα on expression of genes encoding intestinal barrier proteins. To this end we used triacylglycerols composed of identical fatty acids in combination with gene expression profiling in wild-type and PPARα-null mice. Treatment with the synthetic PPARα agonist WY14643 served as reference. Results: We identified 74 barrier genes that were PPARα-dependently regulated 6 hours after activation with WY14643. For eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and oleic acid (OA) these numbers were 46, 41, and 19, respectively. The overlap between EPA-, DHA-, and WY14643-regulated genes was considerable, whereas OA treatment showed limited overlap. Functional implications inferred form our data suggested that nutrient-activated PPARα regulated transporters and phase I/II metabolic enzymes were involved in a) fatty acid oxidation, b) cholesterol, glucose, and amino acid transport and metabolism, c) intestinal motility, and d) oxidative stress defense. Conclusion: We identified intestinal barrier genes that were PPARα-dependently regulated after acute activation by fatty acids.This knowledge provides a better understanding of the impact dietary fat has on the barrier function of the gut, identifies PPARα as an important factor controlling this key function, and underscores the importance of PPARα for nutrient-mediated gene regulation in intestine. Keywords: metabolic state analysis
Project description:The intestine is an organ responsible for absorption and metabolism of orally administered drugs. It is necessary to examine the human intestinal expression profiles of the genes related to drug absorption, distribution, metabolism, and excretion (ADME), for accurate prediction of pharmacokinetics in the intestine. However, previous studies had issues such as the evaluation limited to specific molecules and regions, and relatively small sample sizes. In this study, to obtain more accurate expression profiles of mRNA and protein in various regions of human intestine, biopsy samples were collected from 38 patients with various regions, duodenum, jejunum, ileum, colon and rectum, and RNA-seq analysis and quantitative proteomics analysis were performed. We performed the expression analysis of drug-metabolizing enzymes (cytochromes P450 (CYP ) and non–CYP enzymes), apical and basolateral drug transporters, and nuclear receptors. Overall, mRNA expression levels of these ADME-related molecules were highly correlated with the protein expression levels. The characteristics of the expression of ADME-related genes in human small and large intestines differed significantly, such as higher or lower expression levels of CYP enzymes in the small or large intestines, respectively. Most CYPs were expressed dominantly in the small intestine. Non-CYPs were expressed in the large intestine, but their expression levels were lower than those in the small intestine. The expression levels of ADME-related genes differed even between the proximal and distal small intestine. The expression of transporters showed their highest abundance in the ileum. The data in the present study contributes to an improved understanding of intestinal ADME of drug candidates, and would be useful for drug discovery research.
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:To identify the possible genes influencing macrophage pro-inflammatory activation, we designed CRISPR screens using a human metabolic sgRNA library containing metabolism-related transcription factors, small molecule transporters, and metabolic enzymes in a Cas9-expressing lentiviral vector.