Rosiglitazone (Rosi), a member of the thiazolidinedione class of drugs used to treat type 2 diabetes, activates the adipocyte-specific transcription factor peroxisome proliferator-activated receptor gamma (PPARg). This activation causes bone loss in animals and humans, at least in part due to suppression of osteoblast differentiation from marrow mesenchymal stem cells (MSC). In order to identify mechanisms by which PPARg2 suppresses osteoblastogenesis and promotes adipogenesis in MSC, we have analyzed the PPARg2 transcriptome in response to Rosi. A total of 4,252 transcriptional changes resulted when Rosi (1 uM) was applied to the U-33 marrow stromal cell line, stably transfected with PPARg2 (U-33/g2), as compared to non-induced U-33/g2 cells. Differences between U-33/g2 and U-33 cells stably transfected with empty vector (U-33/c) comprised 7,928 transcriptional changes, independent of Rosi. Cell type-, time- and treatment-specific gene clustering uncovered distinct patterns of PPARg2 transcriptional control of MSC lineage commitment. The earliest changes accompanying Rosi activation of PPARg2 included adjustments in morphogenesis, Wnt signaling, and immune responses, as well as sustained induction of lipid metabolism. Expression signatures influenced by longer exposure to Rosi provided evidence for distinct mechanisms governing the repression of osteogenesis and stimulation of adipogenesis. Our results suggest interactions that could lead to the identification of a master regulatory scheme controlling osteoblast differentiation.
PPARgamma2 nuclear receptor controls multiple regulatory pathways of osteoblast differentiation from marrow mesenchymal stem cells.
Compound, Time
View SamplesAppropriate nutrition during early development is essential for optimal bone mass accretion; however, linkage between early nutrition, childhood bone mass and prevention of bone loss later in life has not been extensively studied. In this report, we have demonstrated several fundamental issues in the field. 1) A significant prevention of ovariectomy (OVX) -induced bone loss from adult rats can occur with only 14 days consumption of a blueberry-containing diet immediately prior to puberty. 2) The molecular mechanisms underlying these effects involve increased myosin production and preserved a shuttle for transcription factors such as Runx2 from cytoplasm to nucleolus which stimulates osteoblast differentiation and reduces mesenchymal stromal cell senescence. 3) The effects of blueberry diet on preserving fidelity of osteoblast differentiation also overcome reduced osteoblast differentiation and activity due to OVX-induced degradation of collagen matrix.
Feeding blueberry diets in early life prevent senescence of osteoblasts and bone loss in ovariectomized adult female rats.
Sex, Specimen part
View SamplesBlockades in hematopoiesis deprive the host of vital blood cells and frequently cause leukemia. Here we show that inactivation of mTORC1 in hematopoietic stem cells by deletion of Raptor unmasked a cell type, hereby called myelolymphoblastic innate cell (MLIC) based on unique gene expression signature, cell surface markers, morphology and functions. The MLICs are CD11b(+)Gr-1(-)B7-H1(high)F4/80(low) and have morphology of lymphoblasts with active Ig loci but no gene rearrangement. Within weeks of Raptor deletion, the MLICs account for nearly 50% of bone marrow cells and are found throughout both the lymphoid and non-lymphoid organs. Nevertheless, the MLICs are not malignant as they undergo very limited proliferation in vivo. Importantly, the MLICs broadly express pattern-recognition receptors and produce large amounts of inflammatory cytokines in response to all TLR ligands tested, rendering the host highly susceptible to pathogen-associated molecular patterns. Our data suggest that hematopoietic cell-intrinsic mTORC1 prevents development of self-destructive innate immune attack by suppressing generation of MLICs. Overall design: Raptor F/F mice were crossed with Mx1-Cre mice for more than 2 generations to get Raptor F/F (Ctrl) and Raptor F/F, Mx1-Cre (cKO) mice. Sex-matched 6-8 weeks old Ctrl mice and cKO mice were treated with polyinosinic: polycytidylic acid (pIpC) every other day for consecutive 7 times by intra-peritoneal (i.p.) injection to induce Cre expression and Raptor deletion in mouse hematopoietic system. Raptor mice were sacrificed 2-3 weeks after the last injection of pIpC. Whole BM cells from Raptor Ctrl mice (n=3) and FACS-sorted CD11b(+)Gr-1(-) BM MLICs from Raptor cKO mice (n=3) were used for RNA isolation and subsequent cDNA libraries construction. mRNA profiles of Ctrl-WBM and cKO-MLIC were examined by RNA-sequencing, in triplicate, using Illumina HiSeq 2000.
A population of innate myelolymphoblastoid effector cell expanded by inactivation of mTOR complex 1 in mice.
No sample metadata fields
View SamplesHistone deacetylase 3 (HDAC3) is an epigenome-modifying enzyme that is required for normal mouse development and tissue-specific functions. In vitro, HDAC3 protein itself has minimal enzyme activity, but gains its histone deacetylation function from stable association with the conserved deacetylase activation domain (DAD) contained in nuclear receptor corepressors NCOR1 and SMRT. Here we show that HDAC3 enzyme activity is undetectable in mice bearing point mutations in the DAD of both NCOR1 and SMRT (NS-DADm), despite normal levels of HDAC3 protein. Local histone acetylation is increased, and genomic HDAC3 recruitment is reduced though not abrogated. Remarkably, the NS-DADm mice are born and live to adulthood, whereas genetic deletion of HDAC3 is embryonic lethal. These findings demonstrate that nuclear receptor corepressors are required for HDAC3 enzyme activity in vivo, and suggest that a deacetylase-independent function of HDAC3 may be required for life.
Nuclear receptor co-repressors are required for the histone-deacetylase activity of HDAC3 in vivo.
Specimen part, Time
View SamplesWe report the hepatic gene expression changes in NCOR and SMRT DADm-mutated mice.
Nuclear receptor co-repressors are required for the histone-deacetylase activity of HDAC3 in vivo.
Specimen part, Time
View SamplesTHO2 and HPR1 proteins were co-depleted from Drosophila S2 cells and their role in mRNA export analysed by comparing total RNA and cytoplasmic RNA
The superhelical TPR-repeat domain of O-linked GlcNAc transferase exhibits structural similarities to importin alpha.
None
Cell line
View SamplesThis SuperSeries is composed of the SubSeries listed below.
HNF6 and Rev-erbα integrate hepatic lipid metabolism by overlapping and distinct transcriptional mechanisms.
Sex, Age, Specimen part
View SamplesThe molecular mechanism of how lung sacculation occurs is poorly understood. Loss of epithelial Hdac3 results in defects in the proper expansion of distal lung saccules into primitive alveoli. In this microarray, we seek to investigate the gene profile changes caused by loss of Hdac3 to better understand the molecular pathways that are regulated by Hdac3 during lung sacculation.
HDAC3-Dependent Epigenetic Pathway Controls Lung Alveolar Epithelial Cell Remodeling and Spreading via miR-17-92 and TGF-β Signaling Regulation.
Specimen part
View SamplesWe address the function of HNF6 in the mouse liver metabolism and Rev-erba cistrome
HNF6 and Rev-erbα integrate hepatic lipid metabolism by overlapping and distinct transcriptional mechanisms.
Sex, Age, Specimen part
View SamplesE-cadherin, a protein encoded by the CDH1 gene is the dominant epithelial cell adhesion molecule playing a crucial role in epithelial tissue polarity and structural integrity. The progression of 90% or more carcinomas is believed to be mediated by disruption of normal E-cadherin expression, subcellular localization or function. Despite the strong correlation between E-cadherin loss and malignancy the mechanism through how this occurs is not known in most sporadic and hereditary epithelial carcinomas. Previous works have shown the importance of CDH1 intron 2 sequences for proper gene and protein expression supporting the possibility of these being cis-modulators of E-cadherin expression/function. but when co-expressed it led to reduced cell-cell adhesiveness, increased invasion and angiogenesis. By expression array analysis, IFITM1 and IFI27 levels were found to be increased upon CDH1a overexpression. Importantly, CDH1a was found to be de novo expressed in gastric cancer cell lines when compared to normal stomach.
Transcription initiation arising from E-cadherin/CDH1 intron2: a novel protein isoform that increases gastric cancer cell invasion and angiogenesis.
Specimen part, Cell line
View Samples