Project description:Our data indicated that activation of the PPARg nuclear receptor induces a retinoid response in human dendritic cells. In order to assess the contribution of retinoid signaling to the PPARg response we decided to use a combination of pharmacological activators and inhibitors of these pathways. Cells were treated with the synthetic PPARg ligand rosiglitazone (RSG), or with RSG along with the RARa antagonist (AGN193109) to block RARa mediated gene expression, or the RARa specific agonists (AM580) alone. This design allows one to determine if retinoid signaling is a downstream event of PPARg activation and what portion of PPARg regulated genes are regulated via induced retinoid signaling. Keywords: ligand response
Project description:Our data indicated that activation of the PPARg nuclear receptor induces a retinoid response in human dendritic cells. In order to assess the contribution of retinoid signaling to the PPARg response we decided to use a combination of pharmacological activators and inhibitors of these pathways. Cells were treated with the synthetic PPARg ligand rosiglitazone (RSG), or with RSG along with the RARa antagonist (AGN193109) to block RARa mediated gene expression, or the RARa specific agonists (AM580) alone. This design allows one to determine if retinoid signaling is a downstream event of PPARg activation and what portion of PPARg regulated genes are regulated via induced retinoid signaling. Experiment Overall Design: Monocytes were cultured for 5 days with 500 U/ml IL-4 and 800 U/ml GM-CSF, cytokine treatment was repeated at day 3. Ligands were added at the beginning of differentiation but AGN193109 (AGN) treatment was repeated at day 3. Cells were obtained from three healthy individuals (three biological replicates) and cells were treated with vehicle (DC), 2.5 uM rosiglitazone (DC RSG), 100 nM AM580 (DC AM). RSG treatment was also combined with 1 uM AGN193109 (DC RSG AGN) in this case two biological replicates was used (RNA was obtained from 2. and 3. individuals).
Project description:In order to gain insights into how PPARg regulates different facets of dendritic cell (DC) differentiation, we sought to identify PPARg regulated genes and gene networks in monocyte-derived dendritic cells using global gene expression profiling. We employed an exogenous ligand activation approach using a selective PPARg ligand (rosiglitazone abbreviated as RSG). In addition, we have defined culture conditions in which human serum (HS) induces PPARg activation via a yet uncharacterized endogenous mechanism. We also compared the gene expression profile of developing dendritic cells obtained from patients harboring dominant negative mutations of the PPARg receptor (C114R and C131Y). Keywords: ligand response
Project description:In order to gain insights into how PPARg regulates different facets of dendritic cell (DC) differentiation, we sought to identify PPARg regulated genes and gene networks in monocyte-derived dendritic cells using global gene expression profiling. We employed an exogenous ligand activation approach using a selective PPARg ligand (rosiglitazone abbreviated as RSG). In addition, we have defined culture conditions in which human serum (HS) induces PPARg activation via a yet uncharacterized endogenous mechanism. We also compared the gene expression profile of developing dendritic cells obtained from patients harboring dominant negative mutations of the PPARg receptor (C114R and C131Y). Experiment Overall Design: Monocytes were cultured for 6, 24 hours or 5 days with 500 U/ml IL-4 and 800 U/ml GM-CSF; cytokine treatment was repeated at day 3. Cells were obtained from 12 healthy individuals (6 biological replicates; the 6 and 24 hours samples were obtained from a single individual but the 5 days samples from a different one). Ligands were added at the beginning of differentiation. The 6 and 24 hours cells were treated with vehicle (DC) or 1 uM rosiglitazone (DC RSG), in the case of 5 day cultured cells 2.5 uM RSG was used. Cells were cultured in RPMI plus 10% FBS, in the case of DC4-DC6 cells were also cultured in human AB serum (DC HS). Finally we also obtained cells from patients harboring point mutations of the PPARg receptor (C114R and C131Y)
Project description:Nuclear hormone receptors (NRs) are ligand-binding transcription factors that are widely targeted therapeutically. Hormone binding triggers NR activation and their subsequent proteasomal degradation through unknown ligand-dependent ubiquitin ligase machinery. NR degradation is therapeutically relevant. Efficacy of all-trans-retinoic acid (ATRA) for the treatment of acute promyelocytic leukemia requires degradation of the oncogenic fusion between the Promyelocytic Leukemia Protein (PML) with the Retinoic Acid Receptor Alpha (RARA). Here we use CRISPR-based screens to identify the HECT E3 ubiquitin ligase UBR5 as a ligase for PML-RARA and RARA and observe an agonist-dependent association between RARA and UBR5, which occurs directly on chromatin to regulate transcription. We present the cryo-EM structure of full-length human UBR5 and identify a Leu-X-X-Leu-Leu (LxxLL) binding motif that associates with a conserved degron in RARA. A high-resolution crystal structure of the RARA ligand binding domain in complex with this LxxLL motif shows how UBR5 binding is mutually exclusive with nuclear co-activator engagement. We demonstrate that UBR5 utilizes this conserved degron to additionally regulate hormone dependent protein stability for the glucocorticoid, progesterone, and vitamin D receptors. Our work establishes UBR5-driven NR degradation as an integral regulator of transcriptional signaling by nuclear hormones.
Project description:Nuclear hormone receptors (NRs) are ligand-binding transcription factors that are widely targeted therapeutically. Hormone binding triggers NR activation and their subsequent proteasomal degradation through unknown ligand-dependent ubiquitin ligase machinery. NR degradation is therapeutically relevant. Efficacy of all-trans-retinoic acid (ATRA) for the treatment of acute promyelocytic leukemia requires degradation of the oncogenic fusion between the Promyelocytic Leukemia Protein (PML) with the Retinoic Acid Receptor Alpha (RARA). Here we use CRISPR-based screens to identify the HECT E3 ubiquitin ligase UBR5 as a ligase for PML-RARA and RARA and observe an agonist-dependent association between RARA and UBR5, which occurs directly on chromatin to regulate transcription. We present the cryo-EM structure of full-length human UBR5 and identify a Leu-X-X-Leu-Leu (LxxLL) binding motif that associates with a conserved degron in RARA. A high-resolution crystal structure of the RARA ligand binding domain in complex with this LxxLL motif shows how UBR5 binding is mutually exclusive with nuclear co-activator engagement. We demonstrate that UBR5 utilizes this conserved degron to additionally regulate hormone dependent protein stability for the glucocorticoid, progesterone, and vitamin D receptors. Our work establishes UBR5-driven NR degradation as an integral regulator of transcriptional signaling by nuclear hormones.
Project description:This SuperSeries is composed of the following subset Series: GSE16385: Expression data from human macrophages GSE16386: Expression data from human alternatively activated macrophages GSE25088: PPARg and IL-4-induced gene expression data from wild-type and STAT6 knockout mouse bone marrow-derived macrophages GSE25123: PPARg and IL-4-induced gene expression data from PPARg +/- LysCre and PPARg fl/- LysCre mouse bone marrow-derived macrophages GSE25125: PPARg and IL-4-induced gene expression data from PPARg +/- LysCre and PPARg fl/- LysCre mouse bone marrow-derived alternatively activated macrophages and immature dendritic cells (iDCs) Refer to individual Series
Project description:The PPAR (Peroxisome proliferator-activated receptor) family of nuclear receptors has three members: PPARg, PPARa and PPARd. Although they share similar structures, their biological functions are distinct. PPARg controls lipid storage and adipogenesis, while PPARd is associated with fat burning. The highly specific synthetic ligand for PPARd, GW501516, is a promising drug candidate for obesity and diabetes. Here we use Affymetrix microarray to analyze gene expression profile in mouse embryo fibroblasts treated with 100 nM GW501516 for 0, 2, 8 and 24 hours. These data may provide new clues into the molecular mechanism by which GW501516 ameliorates obesity and diabetes.