Hepatic drug metabolism plays a key role in determining drug response and safety. Studies of drug metabolism generate valuable information about regulation of genes encoding drug-metabolizing enzymes and enzyme functions that are critical in developing dosing guideline. However, current knowledge is insufficient to support dosing guideline for pregnant women. Specifically, substrates of a major drug-metabolizing enzyme CYP2D6 show increased elimination during pregnancy, but the underlying mechanisms are completely unknown largely due to a lack of experimental models. Here, we introduce CYP2D6-humanized (Tg-CYP2D6) mice as an animal model where hepatic CYP2D6 expression is increased during pregnancy, recapitulating the clinically reported changes in CYP2D6-mediated drug metabolism. In these mice, pregnancy had minimal effects on the expression of hepatocyte nuclear factor (HNF) 4a, the transcription factor controlling basal CYP2D6 expression. Krppel-like factor (KLF) 9 and small heterodimer partner (SHP) were found up- and down-regulated in Tg-CYP2D6 mouse livers during pregnancy, respectively. KLF9 enhanced HNF4a-mediated transactivation of the CYP2D6 promoter whereas SHP repressed it. Retinoic acid (RA), an endogenous compound that induces SHP, exhibited decreased hepatic levels during pregnancy. These results indicate that interplay among hepatic transcription factors HNF4a, SHP, and KLF9 underlies CYP2D6 induction during pregnancy, and that retinoic acid is a potential trigger. This is the first report on the mechanisms underlying CYP2D6 induction and illustrates the utility of humanized mice as an in vivo model to study altered drug disposition during pregnancy.
Krüppel-like factor 9 promotes hepatic cytochrome P450 2D6 expression during pregnancy in CYP2D6-humanized mice.
Specimen part
View SamplesIdentification of imprinted genes expressed in adult CD3+ splenocytes
Hematopoietic reconstitution with androgenetic and gynogenetic stem cells.
Sex, Age, Specimen part
View SamplesBACKGROUND: Common variants in the TCF4 gene are among the most robustly supported genetic risk factors for schizophrenia. Rare TCF4 deletions and loss-of-function point mutations cause Pitt-Hopkins syndrome, a developmental disorder associated with severe intellectual disability.
Knockdown of the schizophrenia susceptibility gene <i>TCF4</i> alters gene expression and proliferation of progenitor cells from the developing human neocortex.
Sex, Specimen part, Cell line
View SamplesIn euakryotes, mRNAs must be exported from the nucleus to the cytsoplasm. NXF2 is highly expressed in the mouse male germ cells. We are interested in its function in spermatogenesis, espically in the nuclear RNA export in the testis. To this end, we made Nxf2 mutant mice by gene targeting. In an attempt to identify the mRNA substrates of NXF2, we perform the microarray experiments on testes.
Inactivation of Nxf2 causes defects in male meiosis and age-dependent depletion of spermatogonia.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
HIV‐exposed seronegative commercial sex workers show a quiescent phenotype in the CD4+ T cell compartment and reduced expression of HIV‐dependent host factors.
No sample metadata fields
View SamplesUnderstanding why some indidivual resist HIV-1 infection despite continued exposure is an important goal for vaccine development.
HIV‐exposed seronegative commercial sex workers show a quiescent phenotype in the CD4+ T cell compartment and reduced expression of HIV‐dependent host factors.
No sample metadata fields
View SamplesTo determine the effect on gene expression of intratumoral injection of the Toll-like receptor agonist CpG1826. MC38 colon cancer cells were injected subcutaneously into C57BL/6 mice and allowed to establish until ~40 mm2.
Toll-Like Receptor Triggering and T-Cell Costimulation Induce Potent Antitumor Immunity in Mice.
Specimen part
View SamplesIron is essential for all cells but is toxic in excess, so iron absorption and distribution are tightly regulated. Serum iron is bound to transferrin and primarily enters erythroid cells via receptor-mediated endocytosis of the transferrin receptor (Tfr1). Tfr1 is essential for developing erythrocytes and reduced Tfr1 expression is associated with anemia. The transcription factors STAT5A/B are activated by many cytokines, including erythropoietin. Stat5a/b-/- mice are severely anemic and die perinatally, but no link has been made to iron homeostasis. To study the function of STAT5A/B in vivo, we deleted the floxed Stat5a/b locus in hematopoietic cells with a Tie2-Cre transgene. These mice exhibited microcytic, hypochromic anemia, as did lethally irradiated mice transplanted with Stat5a/b-/- fetal liver cells. Flow cytometry and RNA analyses of erythroid cells from mutant mice revealed a 50% reduction in Tfr1 mRNA and protein. We detected STAT5A/B binding sites in the first intron of the Tfr1 gene and found that expression of constitutively active STAT5A in an erythroid cell line increased Tfr1 levels. Chromatin immunoprecipitation experiments confirmed the binding of STAT5A/B to these sites. We conclude that STAT5A/B is an important regulator of erythroid progenitor iron uptake via its control of Tfr1 transcription.
Hematopoietic-specific Stat5-null mice display microcytic hypochromic anemia associated with reduced transferrin receptor gene expression.
No sample metadata fields
View SamplesLoss of Rb family in HSCs results in a severe phenotype, such as enhanced proliferation and increase in stem cell number. In addition, HSCs were higly mobilized but failed to transplant. Rb family deficient mice rapidly exhibit a myeloproliferative disease with eosinophilic characteristics. Meanwhile, the lymphoid compartment was severely decreased, due to high apoptotic activity in this lineage.
Hematopoietic stem cell quiescence is maintained by compound contributions of the retinoblastoma gene family.
No sample metadata fields
View SamplesSensory neuron diversity is required for organisms to decipher complex environmental cues. In Drosophila, olfactory environment is detected by 50 different olfactory receptor neuron (ORN) classes that are clustered in combinations within distinct sensilla subtypes. Each sensilla subtype houses stereotypically clustered 1-4 ORN identities that arise through asymmetric divisions from a single multipotent sensory organ precursor (SOP). How each class of SOPs acquires a unique differentiation potential that accounts for ORN diversity is unknown. Previously, we reported a critical component of SOP diversification program, Rotund (Rn), which functions to increase ORN diversity by generating novel developmental trajectories from existing precursors within each independent sensilla type lineages. Here, we show that Rn, along with BarH1/H2, Bric-Ã -brac (Bab), Apterous (Ap) and Dachshund (Dac), constitute a functionally conserved transcription factor (TF) network, previously shown to pattern the segmentation of the leg, that patterns the developing olfactory tissue. Precursors with diverse ORN differentiation potentials are selected from concentric rings defined by unique combinations of these TFs along the proximodistal axis of the developing antennal disc. The combinatorial code that demarcates each precursor field is set up by cross-regulatory interactions among different factors within the network. Modifications of this network lead to predictable changes in the diversity of sensilla subtypes and ORN pools. In light of our data, we propose a molecular map that defines Overall design: Time-course RNAseq across 4 developmental stages, inlcuding flies mutant for rotund gene (rn), heterozygotes and wildtype
Comparative analysis of behavioral and transcriptional variation underlying CO<sub>2</sub> sensory neuron function and development in Drosophila.
Specimen part, Subject
View Samples