We screened intronic microRNAs dysregulated in liver of obese mouse models to identify previously uncharacterized coding host genes that may contribute to the pathogenesis of obesity-associated insulin resistance and type 2 diabetes mellitus. Our approach identified the expression of Ectodysplasin A (Eda), the causal gene of X-linked hypohidrotic ectodermal dysplasia (XLHED; MIM 305100) was strongly increased in liver of obese mouse models both in rodents and humans.Eda expression in murine liver is controlled via PPAR? activation, increases in circulation and promotes JNK activation and inhibitory serine phosphorylation of IRS1 in skeletal muscle. Consistently, bi-directional modulation of hepatic Eda expression in mouse models affects systemic glucose metabolism with alterations of muscle insulin signaling, revealing a novel role of EDA as an obesity-associated hepatokine, which impairs insulin sensitivity in skeletal muscle. Overall design: Soleus muscle mRNA profiles of db/db mice at 3 weeks after injection of AAV encoding shRNA targeting mouse Eda or the control scrambled shRNA sequence at the titer of 2-3x10e10 particles/body.
A microRNA screen reveals that elevated hepatic ectodysplasin A expression contributes to obesity-induced insulin resistance in skeletal muscle.
Age, Specimen part, Subject
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 SamplesBackground and aims: Signal transducer and activator of transcription 3 (Stat3) is the main mediator of interleukin-6 type cytokine signaling required for hepatocyte proliferation and hepatoprotection but its role in sclerosing cholangitis (SC) and other cholestatic liver diseases remains unresolved. Methods: We investigated the role of Stat3 in inflammation-induced cholestatic liver injury and used mice lacking the multidrug resistance gene 2 (mdr2-/-) as a model for SC. Results: We demonstrate that conditional inactivation of stat3 in hepatocytes and cholangiocytes (stat3hc) of mdr2-/- mice strongly aggravated bile acid-induced liver injury and fibrosis. Similarly, stat3hc mice are more sensitive to cholic acid feeding than control mice. Global gene expression analysis demonstrated that hepatoprotective signals via epidermal growth factor and insulin-like growth factor 1 are affected upon loss of Stat3. Conclusions: Our data suggest that Stat3 protects cholangiocytes and hepatocytes from bile acid-induced damage thereby preventing liver fibrosis in cholestatic diseases.
Signal transducer and activator of transcription 3 protects from liver injury and fibrosis in a mouse model of sclerosing cholangitis.
Age, Specimen part
View SamplesAnalysis of the transcriptome of dry hda9-1 mutant seeds with those of Col wild-type seeds, using Affymetrix GeneChip Arabidopsis ATH1 Genome Array.
HISTONE DEACETYLASE 9 represses seedling traits in Arabidopsis thaliana dry seeds.
Specimen part
View SamplesMutations in the genes encoding isocitrate dehydrogenase 1 and 2 (IDH1/2) occur in a variety of tumor types, resulting in production of the proposed oncometabolite, 2-hydroxyglutarate (2-HG). How mutant IDH and 2-HG alter signaling pathways to promote cancer, though, remains unclear. Additionally, there exist relatively few cell lines with IDH mutations. To examine the effect of endogenous IDH mutations and 2-HG, we created a panel of isogenic epithelial cell lines with either wild-type IDH1/2 or clinically relevant IDH1/2 mutations. Differences were noted in the ability of IDH mutations to cause robust 2-HG accumulation. IDH1/2 mutants that produce high levels of 2-HG cause an epithelial-mesenchymal transition (EMT)-like phenotype, characterized by changes in EMT-related gene expression and cellular morphology. 2-HG is sufficient to recapitulate aspects of this phenotype in the absence of an IDH mutation. In the cells types examined, mutant IDH-induced EMT is dependent on upregulation of the transcription factor ZEB1 and downregulation of the mir-200 family of microRNAs. Furthermore, sustained knockdown of IDH1 in IDH1 R132H mutant cells is sufficient to reverse many characteristics of EMT, demonstrating that continued expression of mutant IDH is required to maintain this phenotype. These results suggest mutant IDH proteins can reversibly deregulate discrete signaling pathways that contribute to tumorigenesis
Isocitrate dehydrogenase (IDH) mutations promote a reversible ZEB1/microRNA (miR)-200-dependent epithelial-mesenchymal transition (EMT).
Cell line
View SamplesBackground. Multiple myeloma (MM) cells depend on the bone marrow (BM) niche for growth and survival. However, the tumor genes regulated by the niche are largely unknown.
Niche-modulated and niche-modulating genes in bone marrow cells.
Disease, Disease stage, Time
View SamplesGene expression profile (GEP) was analyzed in bone marrow (BM) samples from patients with leukemia or leukemic phase of lymphoma at different time points following aspiration. Among numerous changes in GEP evolved over time a discrete subset of > 60 genes exhibited prompt and sustained switch in expression consistently. Similar results were discovered recently in BM samples from patients with multiple myeloma (GSE36036). GEP was also examined in peripheral blood as well as in BM samples depleted of red blood cells (=WBC) and in cultured cells from some of the patients.
Niche-modulated and niche-modulating genes in bone marrow cells.
Specimen part, Disease
View SamplesVCaP cells expressing inducible shRNAs for either ERG or a non-targeting control were treated with Doxycycline for 1, 3, 7 and 10 days prior to collection
TMPRSS2:ERG blocks neuroendocrine and luminal cell differentiation to maintain prostate cancer proliferation.
No sample metadata fields
View SamplesA transgenic TMPRSS2:ERG mouse model was engineered in FVB background and compared to its wildtype counterpart in the absence of any treatment This experiment is designed to look at ERG-dependent changes in phenotype and gene expression Overall design: A loxP-GFP-loxP-hERG exon 4-11 cassette was inserted into a BAC clone containing the TMPRSS2 locus using a recombineering kit. This modified BAC was used for pronuclear injection and generation of germline-transmitting mice. One line expressing high GFP was used for pronuclear injection of Cre protein and one sub-line that transmitted the TMPRSS2:ERG transgene into the germline was subsequently bred to homozygosity.
TMPRSS2:ERG blocks neuroendocrine and luminal cell differentiation to maintain prostate cancer proliferation.
No sample metadata fields
View SamplesSubpopulations of human fetal thymocyte and circulating nave T cells were obtained through FACS sorting, including CD3-CD4+CD8- intrathymic T progenitor cells (ITTP), CD3intCD4+CD8+ "double positive" thymocytes (DP), CD3highCD4+CD8- "single positive" thymocytes (SP4), CD3+CD4+CD8-CD45RA+CD62L+ nave T cells from cord blood (CB4+), and CD3+CD4+CD8-CD45RA+CD62L+ nave T cells from adult blood (AB4+).
Gene expression profiles during human CD4+ T cell differentiation.
No sample metadata fields
View Samples