Project description:Glucocorticoids (GCs) are key mediators of stress response and are widely used as pharmacological agents to treat immune diseases, such as asthma and inflammatory bowel disease, and certain types of cancer. GCs act mainly by activating the GC receptor (GR), which interacts with other transcription factors to regulate gene expression. Here, we combined different functional genomics approaches to gain molecular insights into the mechanisms of action of GC. By profiling the transcriptional response to GC over time in 4 Yoruba (YRI) and 4 Tuscans (TSI) lymphoblastoid cell lines (LCLs), we suggest that the transcriptional response to GC is variable not only in time, but also in direction (positive or negative) depending on the presence of specific interacting TFs. Accordingly, when we performed ChIP-seq for GR and NF-kB in two YRI LCLs treated with GC or with vehicle control, we observed that features of GR binding sites differ for up- and down-regulated genes. Finally, we show that eQTLs that affect expression patterns only in the presence of GC are 1.9-fold more likely to occur in GR binding sites, compared to eQTLs that affect expression only in its absence. Our results indicate that genetic variation at GR and interacting transcription factors binding sites influences variability in gene expression, and attest to the power of combining different functional genomic approaches. Total RNA obtained from lymphoblastoid cell lines treated with either dexamethasone or EtOH (vehicle for dexamethasone) for 2, 4, 8, 12, 16, or 24 hours.
Project description:Glucocorticoids (GCs) are key mediators of stress response and are widely used as pharmacological agents to treat immune diseases, such as asthma and inflammatory bowel disease, and certain types of cancer. GCs act mainly by activating the GC receptor (GR), which interacts with other transcription factors to regulate gene expression. Here, we combined different functional genomics approaches to gain molecular insights into the mechanisms of action of GC. By profiling the transcriptional response to GC over time in 4 Yoruba (YRI) and 4 Tuscans (TSI) lymphoblastoid cell lines (LCLs), we suggest that the transcriptional response to GC is variable not only in time, but also in direction (positive or negative) depending on the presence of specific interacting TFs. Accordingly, when we performed ChIP-seq for GR and NF-kB in two YRI LCLs treated with GC or with vehicle control, we observed that features of GR binding sites differ for up- and down-regulated genes. Finally, we show that eQTLs that affect expression patterns only in the presence of GC are 1.9-fold more likely to occur in GR binding sites, compared to eQTLs that affect expression only in its absence. Our results indicate that genetic variation at GR and interacting transcription factors binding sites influences variability in gene expression, and attest to the power of combining different functional genomic approaches. GR and NFkB ChIP-seq in lymphoblastoid cell lines treated with either dexamethasone or EtOH (vehicle for dexamethasone) for 1 hour.
Project description:Analysis of dexamethasone-regulation of muscle mass at gene expression level. The hypothesis tested in the present study was that the presence of MuRF1 contributes to the extent of gene expression changes observed in specific sets of genes during a challenge leading to muscle atrophy. Results provide important information on the response of triceps surae muscle to synthetic glucocorticoid treatment, such as specific cell signaling and metabolic enzyme genes, that may be influenced by MuRF1 during atrophy. Total RNA obtained from isolated triceps surae muscle subjected to 3 or 14 days dexamethasone treatment compated to untreated littermate control muscles.
Project description:Acute Myeloid Leukemia (AML) is a heterogeneous disease with several recurrent cytogenetic abnormalities. Despite genomics and transcriptomics profiling efforts to understand AML’s heterogeneity, studies focused on the proteomic profiles associated with pediatric AML cytogenetic features remain limited. Furthermore, the majority of biological functions within cells are operated by proteins (i.e., enzymes) and most drugs target the proteome rather than the genome or transcriptome, thus, highlighting the significance of studying proteomics.
Project description:Extensive changes in post-translational histone modifications accompany the rewiring of the transcriptional program during stem cell differentiation. However, the mechanisms controlling the changes in specific chromatin modifications and their function during differentiation remain only poorly understood. We show that histone H2B monoubiquitination (H2Bub1) significantly increases during differentiation of human mesenchymal stem cells (hMSCs), various lineage-committed precursor cells and in diverse organisms. Furthermore, the H2B ubiquitin ligase RNF40 is required for the induction of differentiation markers and transcriptional reprogramming of hMSC. This function is dependent upon CDK9 and the WAC adaptor protein, which are required for H2B monoubiquitination. Finally, we show that RNF40 is required for the resolution of the H3K4me3/H3K27me3 bivalent poised state on lineage-specific genes during the transition from an inactive to active chromatin conformation. Thus, these data indicate that H2Bub1 is required for maintaining multipotency of hMSC cells and plays a central role in controlling stem cell differentiation. This set contains 29 microarray samples and includes the following 5 conditions: undifferentiated hMSCs, 2 day osteoblast differentiation, 5 day osteoblast differentiation, 2 day adipocyte differentiation, and 5 day adipocyte differentiation. 3 siRNA control samples and 3 RNF40 knockdown samples for each condition (except two control siRNA samples for 2 days osteoblast differentiation).
Project description:we analyzed the expression level change of transcription factors in adipose derived stem cells during osteogenic differentiation and found a candidate target gene, Sox11. We defined that Sox11 suppresses osteogenic differentiation through overexpression and knock down of Sox11. total RNA obtained from adipose derived stem cells subjected to 1,3,6,10 or 14 days in osteogenic differentiation compared to undifferentiated control adipose derived stem cells.
Project description:Human abdominal adipose tissue was obtained with informed consent from a 33-year old Caucasian female (BMI = 32.96 Kg/m2) undergoing lipoaspiration. Adipose stromal cells (hASCs) were isolated and differentiated into adipocytes in vitro. Two technical replicates from 9 time points relative to induction of adipogenesis (day 0). Also, one sample from pre-adipocytes (day -2) grown without FGF.
Project description:Human UL3 cells (U20S derivatives containing GR and an MMTV-luc transgene) were treated with dexamethasone for 0, 1 or 4 hrs. Chromatin was harvested, digested with to ~70% mononucleosomes with MNase, and isolated mononucleosome fragments were used to probe custom Nimblegen genomic tiling microarrays. In addition, human HL60 cells were treated with or without DMSO to induce granulocyte differentiaton, and mononucleosome positions mapped. MNase digested bare DNA fragments of ~500 bp average length from UL3 cells was used as a control. Mononucleosome positions at tiled genes for UL3 cells +/- dexamethasone and HL60 cells +/- DMSO.
Project description:Epstein-Barr virus (EBV) infection of primary human B cells drives their indefinite proliferation into lymphoblastoid cell lines (LCLs). B cell immortalization depends on expression of viral latency genes as well as the regulation of host genes. Given the important role of miRNAs in regulating fundamental cellular processes, in this study we assayed changes in host miRNA expression during primary B cell infection by EBV. We observed and validated dynamic changes in several miRNAs from early proliferation through immortalization; oncogenic miRNAs were induced and tumor suppressor miRNAs were largely repressed. However, one miRNA described as a p53-targeted tumor suppressor, miR-34a, was strongly induced by EBV infection and expressed in many EBV and KSHV-infected lymphoma cell lines. The EBV latent membrane protein 1 (LMP1) was sufficient to induce miR-34a requiring downstream NFM-NM-:B activation, but independent of functional p53. Furthermore, over-expression of miR-34a was not toxic in several B lymphoma cell lines and inhibition of miR-34a impaired the growth of EBV transformed cells. This study identifies a pro-growth role for a tumor suppressive miRNA in oncogenic virus-mediated transformation highlighting the importance of studying miRNA function in different cellular contexts. miRNA expression profiling of human B-cells, EBV-infected, proliferating B cells and Monoclonal LCLs from 3 different donors was conducted with the use of up to 2 M-NM-<g total RNA for sample