Project description:To determine a gene/molecular fingerprint of multiple myeloma (MM) endothelial cells (MMECs), also identifying some of the vascular mechanisms that govern the malignant progression from quiescent monoclonal gammopathy of undetermined significance (MGUS). A comparative gene expression profiling (GEP) was carried out on patient-derived MMECs and MGUS endothelial cells (MGECs) using the Affymetrix U133A Arrays. Expression of selective vascular markers were also validated by RT-PCR and immunoblotting analysis in primary cultures of ECs isolated from total bone marrow (BM)-mononuclear cells. Twenty-two genes were found differently expressed in MMECs compared to MGECs (with 14 down-regulated and 8 up-regulated), thus proving that molecular differences were maintained in vitro. Specific pathways analysis revealed transcriptional and protein expression changes for key regulators of extracellular matrix formation and bone remodeling, cell-adhesion, chemotaxis, angiogenesis, resistance to apoptosis, and cell-cycle regulation. Specifically, we focused on six of these genes (DIRAS3, SERPINF1, SRPX, BNIP3, IER3 and SEPW1), which were not previously functionally correlated to the overangiogenic phenotype of MMECs and disease activity. These data identified distinct EC gene expression profiles and some vascular phenotypes that could influence the remodeling of the BM-microenvironment in patients with active MM. A better understanding of the linkage between genetic and epigenetic events in MM tumor/ECs may contribute to the molecular classification of the disease, thereby identifying selective targets of more effective anti-vessel/stroma therapeutic strategies. Experiment Overall Design: This series of microarray experiments contains the gene expression profiles of five samples from HUVECs (Human Umbilical Vein Endothelial Cells) and five bone marrow ECs (endothelial cells) samples from newly diagnosed MGUS and MM patients, respectively. Centrifugation on Ficoll gradient of heparinized BM-aspirates was followed by polystyrene flask adherence to isolate stromal cells from plasma cells in suspension. Adherent stromal elements were first immunodepleted of macrophages and residual plasma cells with CD14 and CD38 monoclonal antibody (mAb)-coated flasks (mAbs were from Immunotech, Coulter, Marseilles, France), and then incubated with magnetic microbeads coated with Ulex europaeus-1 lectin. Freshly-isolated ECs were cultured in complete medium RPMI-1640 medium supplemented with 10% heat-inactivated FCS and 1% glutamine to allow cell spreading and growth. The purity and viability of EC cultures grown at least one passage (more than 97% viable cells) were assessed by fluorescence-activated cell sorting (FACS, FACS Canto II, Becton Dickinson, San Jose, CA) with double positivity for factor VIII-related antigen (FVIII-RA, a highly specific EC marker) and CD105 (or endoglyn, a molecule strongly expressed by ECs) as well as for CD14 and CD38 negativity. Analysis of mRNA transcripts for FVIII-RA, CD38, CD105 and IgH VDJ region was also performed by RT-PCR, and EC viability was assessed by trypan blue viable staining. HUVECs were purchased from Clonetics Biowhittaker (Walkersville, MD) and cultured in EGM-2MV media (Clonetics Biowhittaker). Five micrograms of total RNA was processed and, in accordance with the manufacturer's protocols, 15 micrograms of fragmented biotin-labelled cRNA were hybridized on GeneChip Human Genome U133A Arrays (Affymetrix Inc.). The arrays were scanned using the Agilent GeneArray Scanner G2500A (Affymetrix). The images were acquired using Affymetrix MicroArray Suite (MAS) 5.0 software and the probe level data converted to expression values using the Bioconductor function for the Robust Multi-Array average (RMA) procedure (Irizarry et al, 2003), in which perfect match intensities are background adjusted, quantile-quantile normalized and log2-transformed.

Project description:Native bone marrow mesenchymal stem/stromal cells (BM-MSCs) participate in generating and shaping the skeleton and bone marrow throughout the lifespan. Moreover, BM-MSCs regulate hematopoiesis by contributing to the hematopoietic stem cell niche in providing critical cytokines, chemokines and extracellular matrix components. However, BM-MSCs per se contain a heterogeneous cell population that remains ill-defined. Although studies on the taxonomy of native BM-MSCs in mice have just started to emerge, the taxonomy of native human BM-MSCs remains unelucidated. By using single-cell RNA sequencing (scRNA-seq), we aimed to define a proper taxonomy for native human BM non-hematopoietic subsets including endothelial cells (ECs) and mural cells (MCs) but with a focal point on MSCs. To this end, transcriptomic scRNA-seq data were generated from 5 distinct BM donors and were analyzed together with other transcriptomic data and with bioinformatics analyses at different levels to identify, characterize and classify distinct native subsets with relevant biomarkers. We could ascribe novel specific biomarkers to ECs, MCs and MSCs. Unlike ECs and MCs, MSCs exhibited an adipogenic transcriptomic pattern while co-expressing genes related to hematopoiesis support and multilineage commitment potential. Furthermore, by a comparative analysis of scRNA-seq of BM cells from humans and mice, we identified core genes conserved in both species. Notably, we identified MARCKS, CXCL12, PDGFRA, and LEPR together with adipogenic factors as archetypal biomarkers to reveal native MSCs within BM. In addition, our data suggest some complex gene nodes regulating critical biological functions of native BM-MSCs together with a preferential commitment toward an adipocyte lineage. Overall, our taxonomy for native BM non-hematopoietic compartment provides an explicit depiction of gene expression in human ECs, MCs and MSCs at single-cell resolution. This analysis helps enhance our understanding of the phenotype and the complexity of biological functions of native human BM-MSCs.

Project description:Angiogenesis is essential for cyclic endometrial growth, implantation, and pregnancy maintenance. Vasculogenesis, the formation of new blood vessels by bone marrow (BM)-derived endothelial progenitor cells (EPCs), has been shown to contribute to endometrial vasculature. However, it is unknown whether vasculogenesis occurs in neovascularization of the decidua during pregnancy. To investigate the contribution of BM-derived EPCs to vascularization of the pregnant uterus, we induced non-gonadotoxic submyeloablation by 5-fluorouracil administration to wild-type FVB/N female mice recipients followed by BM transplantation from transgenic mice expressing green fluorescent protein (GFP) under regulation of Tie2 endothelial-specific promoter. Following 1 month, Tie2-GFP BM-transplanted mice were bred and sacrificed at various gestational days (ED6.5, ED10.5, ED13.5, ED18.5, and postpartum). Bone-marrow-transplanted non-pregnant and saline-injected pregnant mice served as controls (n = 5-6/group). Implantation sites were analyzed by flow cytometry, immunohistochemistry, and immunofluorescence. While no GFP-positive EPCs were found in non-pregnant or early pregnant uteri of BM-transplanted mice, GFP-positive EPCs were first detected in pregnant uterus on ED10.5 (0.12%) and increased as the pregnancy progressed (1.14% on ED13.5), peaking on ED18.5 (1.42%) followed by decrease in the postpartum (0.9%). The percentage of endothelial cells that were BM-derived out of the total endothelial cell population in the implantation sites (GFP+CD31+/CD31+) were 9.3%, 15.8%, and 6.1% on ED13.5, ED18.5, and postpartum, respectively. Immunohistochemistry demonstrated that EPCs incorporated into decidual vasculature, and immunofluorescence showed that GFP-positive EPCs colocalized with CD31 in vascular endothelium of uterine implantation sites, confirming their endothelial lineage. Our findings indicate that BM-derived EPCs contribute to vasculogenesis of the pregnant mouse decidua.

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ScRNAseq atlas of mouse bone marrow endothelial cells

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