PPARg and C/EBPa cooperate to control preadipocyte differentiation (adipogenesis). However, the factors that regulate PPARg and C/EBPa expression during adipogenesis remain largely unclear. Here we show PTIP, a protein that associates with histone H3K4 methyltransferases, regulates PPARg and C/EBPa expression in mouse embryonic fibroblasts (MEFs) and during preadipocyte differentiation. PTIP deletion in MEFs leads to marked decreases of PPARg expression and PPARg-stimulated C/EBP expression. Further, PTIP is essential for induction of PPARg and C/EBPa expression during preadipocyte differentiation. Deletion of PTIP impairs the enrichment of H3K4 trimethylation and RNA polymerase II on PPARg and C/EBPa promoters. Accordingly, PTIP-/- MEFs and preadipocytes all show striking defects in adipogenesis. Furthermore, rescue of the adipogenesis defect in PTIP-/- MEFs requires co-expression of PPARg and C/EBPa. Finally, deletion of PTIP in brown adipose tissue significantly reduces tissue weight in mice. Thus, by regulating PPARg and C/EBPa expression, PTIP plays a critical role in adipogenesis.
Histone methylation regulator PTIP is required for PPARgamma and C/EBPalpha expression and adipogenesis.
Cell line
View SamplesThis SuperSeries is composed of the SubSeries listed below.
An integrated systems biology approach identifies positive cofactor 4 as a factor that increases reprogramming efficiency.
Sex, Specimen part
View SamplesMultipotent spermatogonial stem cells (mSSCs) derived from SSCs are a potential new source of individualized pluripotent cells in regenerate medicine such as ESCs. We hypothesized that the culture-induced reprogramming of SSCs was mediated by a mechanism different from that of iPS, and was due to up-regulation of specific pluripotency-related genes during cultivation. Through a comparative analysis of expression profile data, we try to find cell reprogramming candidate factors from mouse spermatogonial stem cells. We used microarrays to analyze the gene expression profiles of culture-induced reprogramming converting unipotent spermatogonial stem cells to pluripotent spermatogonial stem cells.
An integrated systems biology approach identifies positive cofactor 4 as a factor that increases reprogramming efficiency.
Sex, Specimen part
View SamplesVinylidene Chloride has been widely used in the production of plastics and flame retardants. Exposure of B6C3F1 to VDC in the 2-year National Toxicology Program carcinogenicity bioassay resulted in a dose-dependent increase in renal cell hyperplasias, adenomas, and carcinomas (RCCs). Global gene expression analysis showed overrepresentation of pathways associated with chronic xenobiotic and oxidative stress in RCCs from VDC-exposed B6C3F1 mice, as well as cMyc overexpression and dysregulation of Tp53 cell cycle checkpoint and DNA damage repair pathways. Trend analysis comparing RCC, VDC-exposed kidney, and vehicle control kidney showed a conservation of pathway dysregulation in terms of overrepresentation of xenobiotic and oxidative stress, and DNA damage and cell cycle checkpoint pathways in both VDC-exposed kidney and RCC, suggesting that these mechanisms play a role in the development of RCC in VDC-exposed mice.
Renal Cell Carcinomas in Vinylidene Chloride-exposed Male B6C3F1 Mice Are Characterized by Oxidative Stress and TP53 Pathway Dysregulation.
Specimen part
View SamplesHepatocellular carcinoma (HCC) is an important cause of morbidity and mortality worldwide. Although the risk factors of human HCC are well known, the molecular characterization of this disease is complex, and treatment options in general remain poor. The use of rodent models to study human cancer has been extensively pursued both through genetically engineered rodents and rodent models used in carcinogenicity and toxicology studies. In particular, the B6C3F1 mouse used in the National Toxicology Program (NTP) 2-year bioassay has been used to evaluate the carcinogenic effects of environmental and occupational chemicals, and other compounds. The high incidence of spontaneous HCC in the B6C3F1 mouse has challenged its use as a model for chemically induced HCC in terms of relevance to the human disease. Using global gene expression profiling, we identify the dysregulation of several mediators similarly altered in human HCC, including re-expression of fetal oncogenes, upregulation of protooncogenes, downregulation of tumor suppressor genes, and abnormal expression of cell cycle mediators, growth factors, apoptosis regulators, and angiogenesis and extracellular matrix remodeling factors. Although important differences in etiology and pathogenesis remain between human and mouse HCC, there are important similarities in global gene expression and the types of signaling networks dysregulated in mouse and human HCC. These data provide further relevance for the use of this model in hazard identification of compounds with potential human carcinogenicity risk, and may help in better understanding mechanisms of tumorigenesis due to chemical exposure in the NTP 2-year carcinogenicity bioassay.
Global gene profiling of spontaneous hepatocellular carcinoma in B6C3F1 mice: similarities in the molecular landscape with human liver cancer.
Specimen part
View SamplesIntroduction: Lung cancer is the leading cause of cancer-related death in people. There are several chemically induced and genetically modified mouse models used to study lung cancer. We hypothesized that spontaneous murine (B6C3F1) lung tumors can serve as a model to study human non-small cell lung cancer (NSCLC). Methods: RNA was extracted from untreated 2-year-old B6C3F1 mouse spontaneous lung (SL) tumors and age-matched normal lung tissue from a chronic inhalation NTP study. Global gene expression analysis was performed using Affymetrix Mouse Genome 430 2.0 GeneChip arrays. After data normalization, for each probe set, pairwise comparisons between groups were made using a bootstrap t-test while controlling the mixed directional false discovery rate (mdFDR) to generate a differential gene expression list. IPA, KEGG, and EASE software tools were used to evaluate the overrepresented cancer genes and pathways. Results: MAPK and TGF-beta pathways were overrepresented within the dataset. Almost all of the validated genes by quantitative real time RT-PCR had comparable directional fold changes with the microarray data. The candidate oncogenes included Kras, Braf, Raf1, Id2, Hmga1, Cks1b, and Foxf1. The candidate tumor suppressor genes included Rb1, Cdkn2a, Hnf4a, Tcf21, Ptprd, Hpgd, Hopx, Ogn, Id4, Hoxa5, Smad6, Smad7, Zbtb16, Cyr61, Dusp4, and Ifi16. In addition, several genes important in lung development were also differentially expressed, such as Smad6, Hopx, Sox4, Sox9 and Mycn. Conclusion: In this study, we have demonstrated that several cancer genes and signaling pathways relevant for human NSCLC were similarly altered in spontaneous murine lung tumors.
Differential transcriptomic analysis of spontaneous lung tumors in B6C3F1 mice: comparison to human non-small cell lung cancer.
Disease, Disease stage
View SamplesGinkgo biloba leaf extract (GBE) has been used for centuries in traditional Chinese medicine and today is used as an herbal supplement for various indications such as improving neural function, anti-oxidant and anti-cancer effects. As part of the herbal supplement industry, these compounds are largely unregulated, and may be consumed in large concentrations over extended periods of time. This is of particular concern, because the long-term effects in terms of toxicity and carcinogenicity data is lacking for many herbal products, including GBE. The 2-year B6C3F1 mouse carcinogenicity bioassay indicated a marked dose-related increase in hepatocellular carcinoma (HCC) development associated with exposure to GBE. We have shown that the mechanism of this increase in tumorigenesis is related to a marked increase in the incidence of -catenin mutation, and report a novel mechanism of constitutive -catenin activation through post-translational modification leading to constitutive Wnt signaling and unregulated growth signaling and oncogenesis. Furthermore, using global gene expression profiling, we show that GBE-induced HCC exhibit overrepresentation of gene categories associated with human cancer and HCC signaling including upregulation of relevant oncogenes and suppression of critical tumor suppressor genes, as well as chronic oxidative stress, a known inducer of calpain-mediated degradation and promoter of hepatocarcinogenesis in humans. These data provide a molecular mechanism to GBE-induced HCC in B6C3F1 mice that is relevant to human cancer, and provides relevant molecular data that will provide the groundwork for further risk assessment of unregulated compounds, including herbal supplements.
Hepatocellular carcinomas in B6C3F1 mice treated with Ginkgo biloba extract for two years differ from spontaneous liver tumors in cancer gene mutations and genomic pathways.
Specimen part
View SamplesSMRT (silencing mediator of retinoid and thyroid hormone receptors) is recruited by numerous transcription factors to mediate lineage and signal dependent transcriptional repression. We generated a knock-in mutation in the receptor interaction domain (RID) of SMRT (SMRTmRID) that solely disrupts its interaction with nuclear hormone receptors. SMRTmRID-derived 3T3-MEFs display a dramatically increased adipogenic capacity and accelerated differentiation rate. We measured global gene expression in wild-type versus SMRTmRID-derived 3T3-MEFs in the undifferentiated state to examine which pathways were altered. Our results demonstrate that SMRT-RID dependent repression is a key determinant of the adipogenic set point.
SMRT repression of nuclear receptors controls the adipogenic set point and metabolic homeostasis.
No sample metadata fields
View SamplesThe expression of the small molecular weight heat shock protein (Hsp) H11 kinase/Hsp22 (Hsp22) is restricted to a limited number of tissues, including the heart and skeletal muscle, both in rodents and in humans. We generated a mouse knockout (KO) model, and investigated the role of Hsp22 in regulating cardiac hypertrophy in response to pressure overload. We compared gene expression profiles between WT and KO mice in basal condition and three days pressure overload after transverse aortic constriction (TAC). These data illustrated a novel mechanism of Hsp22-related gene expression in response to cardiac stress.
H11 kinase/heat shock protein 22 deletion impairs both nuclear and mitochondrial functions of STAT3 and accelerates the transition into heart failure on cardiac overload.
Sex, Specimen part
View SamplesWe have previously demonstrated that pre-B-cell colony enhancing factor (PBEF) ais a biomarker in sepsis and sepsis-induced acute lung injury (ALI) with genetic variants conferring ALI susceptibility118. In the current study, we explored the mechanistic participation of PBEF in ALI and ventilator-induced associated lung injury (VIALI). Initial in vitro studies and demonstrated rhPBEF aas a direct rat neutrophil chemotactic factor in vitro producing marked in vivo increases in BAL leukocytes (PMNs) in vivo following (intratracheal injection (,IT) in C57B6 mice. These latter changes were accompanied by increased BAL levels of the PMN chemoattractants (, KC and MIP2), and modest changes in lung vascular and but were not associated with significant increasesin alveolar permeability. We next explored the potential synergism between rhPBEF administration (IT) and a mechanical ventilation model of modest VILI lung injury (4 hours, 30 ml/kg tidal volume). We and observed dramatic synergistic increases in BAL PMNs, and both BAL protein and cytokine levels (IL-6, TNF-?, KC). Gene expression profiling Microarray analysis further supported a major role for PBEF in the induction of gene modules associated with ALI and VALI (NFkB pathway, leukocyte extravasation, apoptosis, toll receptor signaling). Finally, we exposed wild type and heterozygous PBEF+/- mice (targeted deletion of a single PBEF allele deletion) to a model of severe VILImechanical ventilation-induced lung injury (4 hours, 40 ml/kg tidal volume). PBEF+/- mice were significantly protected from VIALI-associated increases in BAL protein and BAL IL-6 levels and exhibited significantly reduced expression of ALI-associated gene expression modules. Together, these results indicate that PBEF is a key inflammatory mediator intimately involved in both the development and severity of ventilator-induced ALI.
Essential role of pre-B-cell colony enhancing factor in ventilator-induced lung injury.
No sample metadata fields
View Samples