Project description:Primary mouse bone marrow mesenchymal stromal cells (BM-MSCs) cultured for bone differentiation were exposed to vehicle (DMSO), synthetic RXR ligand (LG100268), type 2 diabetes therapeutic and PPARγ ligand (Rosiglitazone), and environmental PPARγ ligands (Tributyltin, Triphenyl Phosphate, and MEHP) to evaluate differential gene expression as well as nuclear receptor expression and downstream PPARG target gene expression between all chemical exposures
Project description:In bone marrow (BM), there are two different types of stem/progenitor cells. With respect to hematopoiesis, hematopoietic stem/progenitor cells (HPCs) produce mature blood cells and mesenchymal stromal/stem cells (MSCs) support this. The influence of exposure to low-dose radiation on human HPCs has been investigated, and generation of both immature and mature hematopoietic cells from human HPCs is compromised. On the other hand, the influence of exposure to low-dose radiation on MSCs is not known. This gene expression profiling was created for investigation how low-dose irradiation affects BM-MSCs genomically.
Project description:Bone marrow-mesenchymal stromal cells (BM-MSCs) are key components of the BM niche, where they regulate hemato-poietic stem progenitor cells (HSPCs) homeostasis by direct contact and secreting soluble factors. BM-MSCs also protect the BM niche from excessive inflammation by releasing anti-inflammatory factors and modulating immune cell activity. Thanks to these proper-ties, BM-MSCs were successfully employed in pre-clinical HSPC transplantation models, increasing the rate of HSPC engraftment, accelerating the hematological reconstitution, and reducing the risk of graft failure. However, their clinical use requires extensive in vitro expansion, altering their biological and functional properties. In this work, we analyzed the transcriptomic profile of human BM-MSCs sorted as CD45neg, CD105+, CD73+, and CD90+ cells from the BM aspirates of heathy-donors and corresponding ex-vivo expanded BM-MSCs. We found the expression of immune and inflammatory genes downregulated upon cell culture and selected the transcription factor EGR1 to restore the MSC properties. We overexpressed EGR1 in BM-MSCs and performed in vitro tests to study the functional properties of EGR1-overexpressing BM-MSCs. We concluded that EGR1 increased the MSC response to inflam-matory stimuli and immune cell control and potentiated the MSC hematopoietic supportive activity in co-culture assay, suggesting that the EGR1-based reprogramming may improve the BM-MSC clinical use.
Project description:RNA-seq of human BM-derived mesenchymal stromal cells (MSCs) cocultured with mouse BM cells upon GM-CSF stimulation against MSCs without BM cell coculture
Project description:Bone marrow-derived multipotent stromal cells (BM-MSCs) exhibit therapuetically valuable properties, including the capacity to differentiate into skeletal tissues and modulate immune system activity. These properties depend on proper regulation of dynamic gene expression in response to environmental and developmental stimuli. This study used chromatin immunoprecipitation (ChIP) coupled with human promoter tiling microarray analysis (ChIP-on-chip) to profile histones H3K4me3 and H3K27me3 at promoters genome-wide. The goal of the study was to identify gene promoters marked by H3K27me3 and H3K4me3 in BM-MSCs.
Project description:BRD4, a member of the BET family of histone readers, binds to acetylated lysine of histone H3 and promotes assembly of super-enhancer complexes that drive expression of key oncogenes in acute myeloid leukemia (AML) and other cancers. ARV-825 is a proteolysis-targeting chimera (PROTAC) that targets BRD4 for CRBN-mediated ubiquitination and degradation. BM-MSCs are an important element of the bone marrow microenvironment of AML. To understand how targeting BRD4 in BM-MSCs may contribute to the overall effect on AML of targeting BRD4, we treated BM-MSCs from two normal donors with ARV-825 in vitro. Treatment of BM-MSC monocultures with ARV-825 for 24 hr caused extensive changes in gene expression, highly uniform between triplicates. Although the cultures from the two normal donors showed different profiles, their changes with ARV-825 were highly similar. These changes implicated effects on oxidative stress, osteogenic differentiation, retinoid metabolism, F-actin polymerization, CXCL12, and proliferation.
Project description:We set out to study the effects of the endocrine disrupting chemical tributyltin (TBT) on early lineage commitment of primary bone marrow-derived mesenchymal stem cells (MSCs) from the long bones of C57BL/6 mice. We previously showed that prenatal exposure to nanomolar levels of TBT results in increased adiposity in mice. TBT is an agonist of two nuclear receptors, peroxisome proliferator-activated receptor gamma (PPARγ) and retinoid X receptor (RXR), master regulators of adipogenesis. To test if TBT could influence early MSC lineage commitment we treated these cells with 50 nM TBT, 100 nM Rosiglitazone (ROSI, a pure PPARγ agonist), 100 nM AGN194204 (4204, a pure RXR agonist), and vehicle control (0.1% DMSO) for 48 hours prior to differentiation with a standard adipogenic cocktail. This experiment revealed an RXR-dependent commitment to the adipose lineage. To better understand how TBT induces adipose commimtment, we sequenced RNA from MSCs treated with DMSO (0.1%), ROSI (100 nM), 4204 (100 nM), and TBT (50 nM) for 48 hrs, prior to any differentiation. Unbiased hierarchical clustering analysis showed a clear separation between DMSO and ROSI replicates from 4204 and TBT, strengthening our conclusion that the observed phentype is RXR-dependent. Pathway analysis of differentially expressed genes revealed that TBT and 4204 de-repress targets of the repressive histone modifier Enhancer of zeste 2 (EZH2), the catalytic member of the Polycomb repressive complex 2 (PRC2), which deposits H3K27me3 on histones. We there for preformed ChIP-Seq analysis on MSCs treated with DMSO (0.1%) or TBT (50 nM) for 48 hrs, hypothesizing that TBT would reduce H3K27me3 in proximity to genes that regulate adipose lineage commitment.
Project description:Bone marrow-derived multipotent stromal cells (BM-MSCs) exhibit therapuetically valuable properties, including the capacity to differentiate into skeletal tissues and modulate immune system activity. These properties depend on proper regulation of dynamic gene expression in response to environmental and developmental stimuli. This study used chromatin immunoprecipitation (ChIP) coupled with human promoter tiling microarray analysis (ChIP-on-chip) to profile histones H3K4me3 and H3K27me3 at promoters genome-wide. The goal of the study was to identify gene promoters marked by H3K27me3 and H3K4me3 in BM-MSCs. ChIP-on-chip performed with antibodies to H3K4me3 and H3K27me3 on BM-MSCs from 3 different donors (labeled 1632, 167696, and 8F3560) and with technical replicates.