Recent studies have reported that glycosphingolipids (GSL) might be involved in obesity induced insulin resistance. Those reports suggested that inhibition of GSL biosynthesis in animals ameliorated insulin sensitivity accompanied with improved glycemic control leading to decreased liver steatosis in obese mice. In addition, GSL depletion altered hepatic secretory function. In those studies, ubiquitously acting inhibitors for GSL-biosynthesis have been used to inhibit function of the enzyme Ugcg (UDP-glucose:ceramide glucosyltransferase), catalyzing the first step of the glucosylceramide based GSL-synthesis pathway. In the present study, a genetic approach for GSL deletion in hepatocytes was chosen to achieve full inhibition of GSL synthesis and to prevent possible adverse effects caused by Ugcg-inhibitors. Using the Cre/loxP system under control of the albumin promoter, GSL biosynthesis in hepatocytes and their release into the plasma could be effectively blocked. Deletion of GSL in hepatocytes did not change quantity of bile excretion through the biliary duct. Total bile salt content in bile-, feces- and plasma from mutant mice showed no difference as compared to control animals. Cholesterol concentration in liver-, bile-, feces- and plasma-samples remained unaffected. Lipoprotein concentration in plasma-samples in mutant animals reached similar levels as in their control littermates. No alteration in glucose tolerance after intraperitoneal application of glucose and insulin appeared in mutant animals. A preventive effect of GSL-deficiency on development of liver steatosis after high fat diet feeding could not be observed.
Hepatic glycosphingolipid deficiency and liver function in mice.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Exploiting microRNA and mRNA profiles generated in vitro from carcinogen-exposed primary mouse hepatocytes for predicting in vivo genotoxicity and carcinogenicity.
Specimen part, Compound
View SamplesThe well-defined battery of in vitro systems applied within chemical cancer risk assessment is often characterised by a high false-positive rate, thus repeatedly failing to correctly predict the in vivo genotoxic and carcinogenic properties of test compounds. Toxicogenomics, i.e. mRNA-profiling, has been proven successful in improving the prediction of genotoxicity in vivo and the understanding of underlying mechanisms. Recently, microRNAs have been discovered as post-transcriptional regulators of mRNAs. It is thus hypothesised that using microRNA response-patterns may further improve current prediction methods. This study aimed at predicting genotoxicity and non-genotoxic carcinogenicity in vivo, by comparing microRNA- and mRNA-based profiles, using a frequently applied in vitro liver model and exposing this to a range of well-chosen prototypical carcinogens. Primary mouse hepatocytes (PMH) were treated for 24 and 48h with 21 chemical compounds [genotoxins (GTX) vs. non-genotoxins (NGTX) and non-genotoxic carcinogens (NGTX-C) versus non-carcinogens (NC)]. MicroRNA and mRNA expression changes were analysed by means of Exiqon and Affymetrix microarray-platforms, respectively. Classification was performed by using Prediction Analysis for Microarrays (PAM). Compounds were randomly assigned to training and validation sets (repeated 10 times). Before prediction analysis, pre-selection of microRNAs and mRNAs was performed by using a leave-one-out t-test. No microRNAs could be identified that accurately predicted genotoxicity or non-genotoxic carcinogenicity in vivo. However, mRNAs could be detected which appeared reliable in predicting genotoxicity in vivo after 24h (7 genes) and 48h (2 genes) of exposure (accuracy: 90% and 93%, sensitivity: 65% and 75%, specificity: 100% and 100%). Tributylinoxide and para-Cresidine were misclassified. Also, mRNAs were identified capable of classifying NGTX-C after 24h (5 genes) as well as after 48h (3 genes) of treatment (accuracy: 78% and 88%, sensitivity: 83% and 83%, specificity: 75% and 93%). Wy-14,643, phenobarbital and ampicillin trihydrate were misclassified. We conclude that genotoxicity and non-genotoxic carcinogenicity probably cannot be accurately predicted based on microRNA profiles. Overall, transcript-based prediction analyses appeared to clearly outperform microRNA-based analyses.
Exploiting microRNA and mRNA profiles generated in vitro from carcinogen-exposed primary mouse hepatocytes for predicting in vivo genotoxicity and carcinogenicity.
Specimen part, Compound
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Evaluating microRNA profiles reveals discriminative responses following genotoxic or non-genotoxic carcinogen exposure in primary mouse hepatocytes.
Specimen part, Compound
View SamplesThe study investigated differential gene expression in primary mouse hepatocyte mRNA following 24 and 48 hours of exposure to aflatoxin B1, cisplatin, benzo(a)pyrene, 2,3,7,8-tetrachloordibenzo-p-dioxine, cyclosporin A or Wy-14,643 or their responsive solvent. Three (four for Wy-14,643) biological replicates per compound/solvent.
Evaluating microRNA profiles reveals discriminative responses following genotoxic or non-genotoxic carcinogen exposure in primary mouse hepatocytes.
Specimen part, Compound
View SamplesDifferent types of hair follicles can be found in the skin of mice. It is believed that the signals that control hair follicle differentiation arise from cells in a structure called the dermal papilla. Understanding the nature of those signals is of interest for the biology of the normal tissue.
Sox2-positive dermal papilla cells specify hair follicle type in mammalian epidermis.
No sample metadata fields
View SamplesThe transcriptional repressor Zbtb20 is essential for specification of hippocampal CA1 pyramidal neurons. Moreover, ectopic expression of Zbtb20 is sufficient to transform subicular and retrosplenial areas of D6/Zbtb20S mice to CA1. We used microarrays to identify genes that are repressed by Zbtb20 in developing CA1 pyramidal neurons in the CA1-transformed cortex of D6/Zbtb20S mice.
Zbtb20 defines a hippocampal neuronal identity through direct repression of genes that control projection neuron development in the isocortex.
Specimen part
View SamplesOvarian cancer is one of the most deadly cancers accounting for only 3% of diagnosed cancers, but is the fifth leading cause of cancer deaths among woman; however, the progression of ovarian cancer is poorly understood. To study and further understand the early events that lead to epithelial derived ovarian cancer, we previously developed a cell model of progressive ovarian cancer. Mouse ovarian surface epithelial (MOSE) cells have undergone spontaneous transformation in cell culture and represent pre-neoplastic, non-tumorigenic to an aggressive malignant phenotype.
Changes in gene expression and cellular architecture in an ovarian cancer progression model.
Specimen part
View SamplesThese studies address temporal changes in gene expression during spontaneous sleep and extended wakefulness in the mouse cerebral cortex, a neuronal target for processes that control sleep; and the hypothalamus, an important site of sleep regulatory processes. We determined these changes by comparing expression in sleeping animals sacrificed at different times during the lights on period, to that in animals sleep deprived and sacrificed at the same diurnal time.
Macromolecule biosynthesis: a key function of sleep.
Sex, Age, Specimen part
View SamplesWe wanted to determine how type II versus type III Toxoplasma infection affect host gene expression
Toxoplasma polymorphic effectors determine macrophage polarization and intestinal inflammation.
Cell line
View Samples