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 SamplesIn this study, we characterize transciprtional phenotypes of airway macrophagages (AMs) throughout homeostatsis, inflammation, and repair at single cell granularity. We confirm that cell origin is the major determinant of AM programing and describe two previously uncharacterized, transcriptionally distinct subdivisions of AMs based on proliferative capacity and inflammatory programing. Overall design: We stimulated mice with LPS and then sampled FACs sorted airway macrophage cells using BAL at Days 0, 3, and 6 and sequenced 1,134 cells from these three groups using RNA-seq
Single cell RNA sequencing identifies unique inflammatory airspace macrophage subsets.
Specimen part, Cell line, Subject
View SamplesTo explore the molecular basis for TSC22D4 function in hepatic lipid homeostasis in vivo TSC22D4 was knocked down in the mouse liver using adenovirus and performed genome wide expression analysis.
TSC22D4 is a molecular output of hepatic wasting metabolism.
Specimen part
View SamplesPreviously published data suggested some redundant functions between HDAC1 and HDAC2 in mouse. To test this hypothesis, we used microarrays to have a genome wide analysis at the transcription level of primary MEFs lacking HDAC1, HDAC2.
Histone deacetylases 1 and 2 act in concert to promote the G1-to-S progression.
Sex
View SamplesAdult-onset diseases can be associated with in utero events, but mechanisms for such temporally distant dysregulation of organ function remain unknown. The polycomb histone methyltransferase, Ezh2, stabilizes transcription by depositing repressive histone marks during development that persist into adulthood, but the function of Ezh2-mediated transcriptional stability in postnatal organ homeostasis is not understood. Here, we show that Ezh2 stabilizes the postnatal cardiac gene expression program and prevents cardiac pathology, primarily by repressing the homeodomain transcription factor Six1 in differentiating cardiac progenitors. Loss of Ezh2 in embryonic cardiac progenitors, but not in differentiated cardiomyocytes, resulted in postnatal cardiac pathology, including cardiomyocyte hypertrophy and fibrosis. Loss of Ezh2 caused broad derepression of skeletal muscle genes, including the homeodomain transcription factor Six1, which is expressed in cardiac progenitors but is normally silenced upon cardiac differentiation. Many of the deregulated genes are direct Six1 targets, implying a critical requirement for stable repression of Six1 in cardiac myocytes. Indeed, upon de-repression, Six1 promotes cardiac pathology, as it was sufficient to induce cardiac hypertrophy. Furthermore, genetic reduction of Six1 levels almost completely rescued the pathology of Ezh2-deficient hearts. Thus, repression of a single transcription factor in cardiac progenitors by Ezh2 is essential for stability of the adult heart gene expression program and homeostasis. Our results suggest that epigenetic dysregulation during discrete developmental windows can predispose to adult disease and dysregulated stress responses.
Epigenetic repression of cardiac progenitor gene expression by Ezh2 is required for postnatal cardiac homeostasis.
Specimen part
View SamplesWe have employed gene expression profiling in order to identify targets of transcriptional response to stress in resting mouse Swiss 3T3 fibroblasts, either untreated (control) or treated with anisomycin for 3 or 6 hours to induce the p38/MAP kinase pathway. In order determine transcriptional effects dependent on MSK1/2 kinase activity, H89 inhibitor was used in the study. Overall design: Serum starved (72 h 0.2% FCS) mouse 3T3 cells were treated with anisomycin (188.5 nM) for 3 h or 6h (in duplicates) either with or without 15-min pre-treatment with MSK1/2 inhibitor H89 (10 uM). Untreated, serum-starved cells were used as a control. RNA was collected and gene expression profiling using strand-specific RNA-seq was performed.
H3S28 phosphorylation is a hallmark of the transcriptional response to cellular stress.
No sample metadata fields
View SamplesWe have employed gene expression profiling in order to identify targets of transcriptional response to stress in resting mouse Swiss 3T3 fibroblasts, either untreated (control) or treated with anisomycin to induce the p38/MAP kinase pathway. Overall design: Serum starved (72 h 0.2% FCS) mouse 3T3 cells were treated with anisomycin (188.5 nM) for 1 h (in duplicates). Untreated, serum-starved cells were used as a control. RNA was collected and gene expression profiling using strand-specific RNA-seq was performed.
H3S28 phosphorylation is a hallmark of the transcriptional response to cellular stress.
No sample metadata fields
View SamplesHistone deacetylase 1 (HDAC1) is an enzyme that promotes deacetylation of acetylated lysine residues in histones and other proteins. Histone acetylation is often associated with gene activation and expression. Los of HDAC1 leads to severe problems in development and proliferation. Moreover, it seems to be the major histone deacetylase in mouse embryonic stem cells.
Negative and positive regulation of gene expression by mouse histone deacetylase 1.
No sample metadata fields
View SamplesPancreatic ductal adenocarcinoma (PDAC) is the fourth leading cause of cancer fatalities in Western societies, characterized by high metastatic potential and resistance to chemotherapy. Critical molecular mechanisms of these phenotypical features still remain unknown, thus hampering the development of effective prognostic and therapeutic measures in PDAC. Here we show that transcriptional co-factor Transducin beta-like (TBL) 1 was over-expressed in both human and murine PDAC. Inactivation of TBL1 in human and mouse pancreatic cancer cells reduced cellular proliferation and enhanced chemosensitivity, correlating with diminished glucose uptake, glycolytic flux, and PI3kinase signaling. TBL1 deficiency both prevented and reversed pancreatic tumor growth in mice, triggering transcriptional PI3kinase inhibition also in vivo. As TBL1 mRNA levels were also found to correlate with overall and disease-free survival in a cohort of human PDAC patients and to predict therapy responsiveness in these subjects, TBL1 expression may serve both as a novel prognostic marker and molecular target in the treatment of human PDAC.
Transcriptional co-factor Transducin beta-like (TBL) 1 acts as a checkpoint in pancreatic cancer malignancy.
Cell line, Treatment
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