PTIP-regulated genes in MEF
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE16263 | GEO | 2009/05/29
SECONDARY ACCESSION(S): PRJNA115101
REPOSITORIES: GEO
Similar Datasets
Project description:PPARg and C/EBPa cooperate to control preadipocyte differentiation (adipogenesis). However, the factors that regulate PPARg and C/EBPa expression during adipogenesis remain largely unclear. Here we show PTIP, a protein that associates with histone H3K4 methyltransferases, regulates PPARg and C/EBPa expression in mouse embryonic fibroblasts (MEFs) and during preadipocyte differentiation. PTIP deletion in MEFs leads to marked decreases of PPARg expression and PPARg-stimulated C/EBPα expression. Further, PTIP is essential for induction of PPARg and C/EBPa expression during preadipocyte differentiation. Deletion of PTIP impairs the enrichment of H3K4 trimethylation and RNA polymerase II on PPARg and C/EBPa promoters. Accordingly, PTIP-/- MEFs and preadipocytes all show striking defects in adipogenesis. Furthermore, rescue of the adipogenesis defect in PTIP-/- MEFs requires co-expression of PPARg and C/EBPa. Finally, deletion of PTIP in brown adipose tissue significantly reduces tissue weight in mice. Thus, by regulating PPARg and C/EBPa expression, PTIP plays a critical role in adipogenesis. To identify PTIP-regulated genes, immortalized PTIP conditional knockout PTIPflox/flox MEFs were infected with retroviruses expressing either Cre recombinase or vector alone. We prepared duplicated RNAs from either vector or Cre infected cells (PTIP+/+ or PTIP-/-) for 4 affymetrix microarrays.
2009-05-29 | E-GEOD-16263 | biostudies-arrayexpress
Project description:Developmental transitions are guided by master regulatory transcription factors. During adipogenesis, a transcriptional cascade culminates in expression of PPARg and C/EBPa, which orchestrate activation of the adipocyte gene expression program. However, the coactivators controlling PPARg and C/EBPa expression are less well characterized. Here we show the bromodomain-containing protein, BRD4, regulates transcription of PPARg and C/EBPa. Analysis of BRD4 chromatin occupancy reveals that induction of adipogenesis in 3T3L1 fibroblasts provokes dynamic redistribution of BRD4 to de novo super enhancers proximal to genes controlling adipocyte differentiation. BET bromodomain inhibition impedes BRD4 occupancy at these de novo enhancers and disrupts transcription of Pparg and Cebpa, thereby blocking adipogenesis. Furthermore, silencing of these BRD4-occupied distal regulatory elements at the Pparg locus by CRISPRi demonstrates a critical role for these enhancers in the control of Pparg gene expression and adipogenesis in 3T3L1s. Together, these data establish BET bromodomain proteins as time- and context-dependent coactivators of the adipocyte cell state transition.
2018-03-07 | GSE109940 | GEO
Project description:Visceral fat (VF) and subcutaneous fat (SF) are developmentally different tissues with different gene expression. Islet-1 (ISL1), a LIM-homeobox transcription factor with important developmental and regulatory function in islet, neural, and cardiac tissue, is virtually absent in SF but substantially expressed in the stromovascular [preadipocyte containing] fraction of VF; expression correlates negatively with adiposity in rodents and man. ISL1 expression is transiently increased in 3T3-L1 preadipocytes during early differentiation, suggesting a functional role. To examine the role of ISL1 in adipogenesis, we tested whether retroviral overexpression of ISL1 in 3T3-L1 preadipocytes affected their ability to differentiate into mature adipocytes. Terminal differentiation was assessed by Oil Red O [lipid droplet] staining and by immunoblot detection of adipocyte marker proteins, including aP2 and GLUT4. ISL1 significantly inhibited lipid droplet formation, reduced lipid accumulation (about 80% inhibition, p<0.05), and substantially inhibited aP2 and GLUT4 expression. ISL1 did not inhibit expression of C/EBPb and C/EBPd after induction of differentiation, but reduced PPARg and C/EBPa by >50% at both mRNA and protein level. In addition, the PPARg agonist, rosiglitazone, substantially rescued ISL1 inhibited adipogenesis in the absence of exogenous PPARg, and fully rescued in the presence of exogenous PPARg. In summary, ISL1 overexpression inhibited fat droplet formation, lipid accumulation, and adipocyte-specific gene expression; there was accompanying inhibition of C/EBPa, PPARg and downstream gene expression. We conclude that ISL1 overexpression inhibited adipocyte differentiation by inhibition of PPARg regulated gene expression. As abdominal obesity strongly correlates with insulin resistance, and cardiovascular risk, ISL1 up-regulation may impact abdominal obesity and its concomitant metabolic derangements. Total cellular RNA was isolated from 3T3-L1 cells expressing Flag-ISL1 or not at 48 h following treatment with differentiation cocktail. Individual RNA from biological triplicates was used for microarray analysis.
2012-09-05 | E-GEOD-40565 | biostudies-arrayexpress
Project description:By screening a collection of epigenetic compounds, we find that Lysine-Specific Demethylase 1 (LSD1) inhibitors repress brown adipocyte differentiation. RNAi-mediated Lsd1 knockdown shows similar effect, which can be rescued by expression of wild-type, but not catalytically inactive, LSD1. Furthermore, adenoviral Cre-mediated Lsd1 deletion in mice leads to inhibition of brown adipogenesis, validating the pivotal role of LSD1 in brown fat development in vivo. LSD1 represses gene expression by demethylating H3K4. To identify the target genes of LSD1 during BAT differentiation, we analyzed the H3K4me2 enrichment in preadipocyte.
2016-08-30 | GSE74901 | GEO
Project description:Insulin and IGF-1 promote adipocyte differentiation via complex and overlapping signalling networks. Here we used microarray analysis of brown preadipocytes derived from wild-type and insulin receptor substrate (IRS) knockout (KO) animals, which exhibited progressively impaired differentiation, to define the set of genes that predict adipogenic potential in these cells. 374 genes/ESTs were identified whose expression in preadipocytes correlated with their ultimate ability to differentiate. Many of these genes were related to early adipogenic events, including genes involved in extracellular matrix, cytoskeletal organization, growth arrest, post-mitotic clonal expansion, and inhibitors of adipogenesis, including preadipocyte factor-1 and multiple members of the Wnt-signalling pathway. Reconstitution of IRS-1 KO cells with IRS-1 reversed these changes and restored the ability to differentiate. Several of these genes showed concordant changes in brown adipose tissue in vivo. Necdin was markedly increased in IRS-1 KO cells that could not differentiate, and knockdown of necdin restored brown adipogenesis with down-regulation of Pref-1 and Wnt10a expression. We demonstrated a necdin-E2F4 interaction repressing PPARg transcription. IRS proteins regulated necdin via a CREB dependent pathway, defining a signalling network involved in brown preadipocyte determination.
2007-08-04 | E-GEOD-2556 | biostudies-arrayexpress
Project description:Insulin and IGF-1 promote adipocyte differentiation via complex and overlapping signalling networks. Here we used microarray analysis of brown preadipocytes derived from wild-type and insulin receptor substrate (IRS) knockout (KO) animals, which exhibited progressively impaired differentiation, to define the set of genes that predict adipogenic potential in these cells. 374 genes/ESTs were identified whose expression in preadipocytes correlated with their ultimate ability to differentiate. Many of these genes were related to early adipogenic events, including genes involved in extracellular matrix, cytoskeletal organization, growth arrest, post-mitotic clonal expansion, and inhibitors of adipogenesis, including preadipocyte factor-1 and multiple members of the Wnt-signalling pathway. Reconstitution of IRS-1 KO cells with IRS-1 reversed these changes and restored the ability to differentiate. Several of these genes showed concordant changes in brown adipose tissue in vivo. Necdin was markedly increased in IRS-1 KO cells that could not differentiate, and knockdown of necdin restored brown adipogenesis with down-regulation of Pref-1 and Wnt10a expression. We demonstrated a necdin-E2F4 interaction repressing PPARg transcription. IRS proteins regulated necdin via a CREB dependent pathway, defining a signalling network involved in brown preadipocyte determination. Keywords = brown fat Keywords = preadipocyte Keywords = adipogenesis Keywords = mouse Keywords: parallel sample
2005-06-01 | GSE2556 | GEO
Project description:Dexamethasone (DEX), a synthetic ligand for glucocorticoid receptor (GR), is routinely used to stimulate adipogenesis in culture. GR-depleted preadipocytes show adipogenesis defects one week after induction of differentiation. However, it has remained unclear whether GR is required for adipogenesis in vivo. By deleting GR in precursors of brown adipocytes, we found unexpectedly that GR is dispensable for brown adipose tissue development in mice. In culture, GR-deficient primary or immortalized white and brown preadipocytes showed severely delayed adipogenesis one week after induction of differentiation. However, when differentiation was extended to 3 weeks, GR-deficient preadipocytes showed similar levels of adipogenesis marker expression and lipid accumulation as the wild type cells, indicating that DEX-bound GR accelerates, but is dispensable for, adipogenesis. Consistently, DEX accelerates, but is dispensable for, adipogenesis in culture. We show that DEX-bound GR accelerates adipogenesis by directly promoting the expression of adipogenic transcription factors C/EBPb, C/EBPd, C/EBPa, KLF5, KLF9 and PPARg in the early phase of differentiation. Mechanistically, DEX-bound GR recruits histone H3K27 acetyltransferase CBP to promote activation of C/EBPb-primed enhancers of adipogenic genes. These results clarify the role of GR in adipogenesis in vivo and demonstrate that DEX-mediated activation of GR accelerates, but is dispensable for, adipogenesis.
2016-11-01 | GSE76619 | GEO
Project description:Much of our knowledge on adipogenesis comes from cell culture models of preadipocyte differentiation. Adipogenesis is induced by treating confluent preadipocytes with the adipogenic cocktail, which activates transcription factors (TFs) glucocorticoid receptor (GR) and CREB within minutes and increases expression of TFs C/EBPb/d, KLF4 and Krox20 within hours. All of these TFs have been shown to be capable of promoting adipogenesis in culture when they are overexpressed. However, it has remained unclear whether endogenous KLF4 and Krox20 are required for adipogenesis in culture and in vivo. Using conditional knockout mice and derived white and brown preadipocytes, we show that endogenous KLF4 and Krox20 are dispensable for adipogenesis in culture and brown adipose tissue development in mice. In contrast, the master adipogenic TF PPARg is essential. These results challenge the existing model on transcriptional regulation in the early phase of adipogenesis and highlight the need of studying adipogenesis in vivo.
2016-11-17 | GSE87113 | GEO
Project description:The bone is essential for locomotion, calcium storage and harboring the hematopoietic stem cells (HSCs) that supply the body with mature blood cells throughout life. HSCs reside at the interface of the bone and bone marrow (BM), where active bone remodeling takes place. Although the cellular components of the BM niche have been characterized, little is known about its epigenetic regulation. Here we find that the histone methylation regulator PTIP (Pax interaction with transcription-activation domain protein-1) is required to maintain the integrity of the BM niche by promoting osteoclast differentiation. PTIP directly promotes chromatin changes required for the expression of Pparg (Peroxisome proliferator-activated receptor-γ), a transcription factor essential for osteoclastogenesis. PTIP deletion leads to a drastic reduction of HSCs in the BM and induces extramedullary hematopoiesis. Furthermore, exposure of acute myeloid leukemia cells to a PTIP-deficient BM microenvironment leads to a reduction in leukemia initiating cells (LICs) and increased survival upon transplantation. Taken together, our data identify PTIP as a novel epigenetic regulator of osteoclastogenesis that is required for the integrity of the BM niche to sustain both normal hematopoiesis and leukemia.
2018-09-24 | GSE118329 | GEO
Project description:While adipogenesis is controlled by a cascade of transcription factors, the global gene expression profiles in the early phase of adipogenesis are not well defined. Using microarray analysis of gene expression in 3T3-L1 cells we have identified evidence for the activity of 2568 genes during the early phase of adipocyte differentiation. One of these, ISL1, was of interest since its expression was markedly upregulated at 1 h after initiation of differentiation with a subsequent rapid decline. Overexpression of ISL1 at early times during adipocyte differentiation, but not at later times, was found to profoundly inhibit differentiation. This was accompanied by moderate down-regulation of PPARg levels, substantial down-regulation of PPARg downstream genes and down-regulation of BMP4 levels in preadipocytes. Readdition of BMP4 overcame the inhibitory effect of ISL1 on PPARg but not aP2 expression, a downstream gene of PPARg; and BMP4 also partially rescued ISL1 inhibition of adipogenesis, an effect which is additive with rosiglitazone. These results suggest that ISL1 is intimately involved in early regulation of adipogenesis, modulating PPARg expression and activity via BMP4-dependent and -independent mechanisms. Our time course gene expression survey sets the stage for further studies to explore other early and immediate regulators.
2012-09-05 | GSE40565 | GEO