The contribution of altered posttranscriptional gene silencing (PTGS) to the development of insulin resistance and type 2 diabetes mellitus so far remains elusive. We have described that expression of microRNAs (miR)-143 and -145 is dysregulated in genetic and dietary mouse models of obesity. Induced transgenic overexpression of miR-143, but not miR-145, causes insulin resistance and impaired insulin-stimulated AKT activation. We used microarrays to analyze the underlying molecular mechanisms of miR-143-mediated development of insulin resistance.
Obesity-induced overexpression of miRNA-143 inhibits insulin-stimulated AKT activation and impairs glucose metabolism.
Specimen part, Treatment
View SamplesInsulin resistance represents a hallmark during the development of type 2 diabetes mellitus (T2D) and in the pathogenesis of obesity-associated disturbances of glucose and lipid metabolism 1,2,3. MicroRNA (miR)-dependent posttranscriptional gene silencing has recently been recognized to control gene expression in disease development and progression including that of insulin-resistant T2D. MiRs, whose deregulation alters hepatic insulin sensitivity include miR-143, miR-181 and miR-103/107. Here we report that expression of miR-802 is increased in liver of two obese mouse models and of obese human subjects. Inducible transgenic overexpression of miR-802 in mice causes impaired glucose tolerance and attenuates insulin sensitivity, while reduction of miR-802 expression improves glucose tolerance and insulin action. We identify Hnf1b as a target of miR-802-dependent silencing and shRNA-mediated reduction of Hnf1b in liver causes glucose intolerance, impairs insulin signaling and promotes hepatic gluconeogenesis. In turn, hepatic overexpression of Hnf1b improves insulin sensitivity in db/db mice. Thus, the present study defines a critical role for deregulated expression of miR-802 in the development of obesity-associated impairment of glucose metabolism via targeting Hnf1b and assigns Hnf1b an unexpected role in the control of hepatic insulin sensitivity.
Obesity-induced overexpression of miR-802 impairs glucose metabolism through silencing of Hnf1b.
Sex, Specimen part
View SamplesWe here used whole blood gene expression profiling to differentiate SSc patients from healthy controls (HC) and to identify a specific gene expression and predictive genes for SSc-overlap syndromes.
Whole blood gene expression profiling distinguishes systemic sclerosis-overlap syndromes from other subsets.
Specimen part, Disease, Disease stage
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No associated publication
Sex, Specimen part
View SamplesTest systems to identify developmental toxicants are urgently needed. A combination of human stem cell technology and transcriptome analysis was used here to provide proof-of-concept that toxicants with a related mode of action can be identified, and grouped for read-across. We chose a test system of developmental toxicity, related to the generation of neuroectoderm from pluripotent stem cells (UKN1), and exposed cells for six days to benchmark concentration (BMC) of histone deacetylase inhibitors (HDACi) valproic acid, trichostatin-A, vorinostat, belinostat, panobinostat and entinostat. To provide insight into their toxic action, we identified HDACi consensus genes, assigned them to superordinate biological processes, and mapped them to a human transcription factor network constructed from hundreds of transcriptome data sets. We also tested a heterogeneous group of mercurials (methylmercury, thimerosal, mercury(II)chloride, mercury(II)bromide, 4-chloromercuribenzoic acid, phenylmercuric acid) (BMCs). Microarray data were compared at the highest non-cytotoxic concentration for all 12 toxicants. A support vector machine (SVM)-based classifier predicted all HDACi correctly. For validation, the classifier was applied to legacy data sets of HDACi, and for each exposure situation, the SVM predictions correlated with the developmental toxicity. Finally, optimization of the classifier based on 100 probe sets showed that eight genes (F2RL2, TFAP2B, EDNRA, FOXD3, SIX3, MT1E, ETS1, LHX2) are sufficient to separate HDACi from mercurials. Our data demonstrate, how human stem cells and transcriptome analysis can be combined for mechanistic grouping and prediction of toxicants. Extension of this concept to mechanisms beyond HDACi would allow prediction of human developmental toxicity hazard of unknown compounds with the UKN1 test system.
A transcriptome-based classifier to identify developmental toxicants by stem cell testing: design, validation and optimization for histone deacetylase inhibitors.
Sex, Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
No associated publication
Sex, Specimen part
View SamplesThe in vitro test battery of the European research consortium ESNATS (novel stem cell-based test systems) has been used to screen for potential human developmental toxicants. As part of this effort, the migration of neural crest (MINC) assay has been used to evaluate chemical effects on neural crest function. It identified some drug-like compounds in addition to known environmental toxicants. The hits included the HSP90 inhibitor geldanamycin, the chemotherapeutic arsenic trioxide, the flame-retardant PBDE-99, the pesticide triadimefon and the histone deacetylase inhibitors valproic acid and trichostatin A. Transcriptome changes triggered by these substances in human neural crest cells were recorded and analysed here to answer three questions: (1) can toxicants be individually identified based on their transcript profile; (2) how can the toxicity pattern reflected by transcript changes be compacted/ dimensionality-reduced for practical regulatory use; (3) how can a reduced set of biomarkers be selected for large-scale follow up? Transcript profiling allowed clear separation of different toxicants and the identification of toxicant types in a blinded test study. We also developed a diagrammatic system to visualize and compare toxicity patterns of a group of chemicals by giving a quantitative overview of altered superordinate biological processes (e.g. activation of KEGG pathways or overrepresentation of gene ontology terms). The transcript data were mined for potential markers of toxicity, and 39 transcripts were selected to either indicate general developmental toxicity or distinguish compounds with different modes-of-action in read-across. In summary, we found inclusion of transcriptome data to largely increase the information from the MINC phenotypic test.
Identification of transcriptome signatures and biomarkers specific for potential developmental toxicants inhibiting human neural crest cell migration.
Sex, Specimen part
View SamplesThe Melanoma-associated Antigen gene family (MAGE) generally encodes for tumour antigens. We recently have identified one of the MAGE gene members, Mageb16 to be highly expressed in undifferentiated murine embryonic stem cells (mESCs). The role of Mageb16 for the differentiation of the pluripotent stem cells is completely unknown. Here we demonstrate that Mageb16 (41 kDa) is distributed in cytosol and/or in surface membrane in undifferentiated mESCs. A transcriptome study was performed with differentiated short hairpin RNA (shRNA)-mediated Mageb16 knockdown (KD ESCs) and scrambled control (SCR) ESCs until a period of 22 days. Mageb16 KD ESCs mainly differentiated towards mesodermal derivatives such as cardiovascular lineages. Mesoderm-oriented differentiation initiated biological processes such as adipogenesis, osteogenesis, limb morphogenesis and spermatogenesis were significantly enriched in the differentiated Mageb16 KD ESCs. Cardiomyogenesis in differentiated KD mESCs was stronger when compared to differentiated SCR and wild mESCs. The expression of non-coding RNA (ncRNA) Lin28a and other epigenetic regulatory genes, nucleocytoplasmic trafficking and genes participating in spermatogenesis have also declined faster in the differentiating Mageb16 KD ESCs. We conclude that Mageb16 plays a crucial role for differentiation of ESCs, specifically to the mesodermal lineages. Regulative epigenetic networks and nucleocytoplasmic modifications induced by Mageb16 may play a role for the critical role of Mageb16 for the ESCs differentiation.
Depletion of Mageb16 induces differentiation of pluripotent stem cells predominantly into mesodermal derivatives.
Sex, Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
DAF-16/FOXO and EGL-27/GATA promote developmental growth in response to persistent somatic DNA damage.
Treatment
View SamplesFADD-IEC KO and CASP8 IEC-KO mice spontaneously develop chronic colitis charcterized by inflammatory gene expression. We characterized the role of MLKL, RIPK3, ZBP1, in the upregulation of inlflammatory genes in these mice.
FADD and Caspase-8 Regulate Gut Homeostasis and Inflammation by Controlling MLKL- and GSDMD-Mediated Death of Intestinal Epithelial Cells.
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