Figure 1

Prospective isolation and molecular characterization of mesenchymal cells in LR-MDS. (a) Gating strategy to identify and isolate 7AAD⁻/CD45⁻/CD235a⁻/CD271⁺/CD105⁺ mesenchymal cells. (b) Frequency of mesenchymal cells in normal and MDS samples. (c–f) Transcriptional validation of the mesenchymal identity of 7AAD⁻/CD45⁻/CD235a⁻/CD271⁺/CD105⁺ cells, revealing differential expression in comparison with endothelial subsets of (c) defining cell surface markers (CD271, CD105 and CD31), (d) known mesenchymal markers (CD73, CD90 and CD146), (e) established hematopoiesis-supporting cytokines (CXCL12, ANGPT1 and KITL) and (f) bone lineage markers (BGLAP, RUNX2, SPP1 and ALPL). BM, bone marrow; FPKM, fragments per kilobase of exon per million fragments mapped; FSC-W, forward scattered light-width; SSC-A, side scattered light-area; 7AAD (7-aminoactinomycin D); CD45 (PTPRC: protein tyrosine phosphatase, receptor type, C); CD235a (Glycophorin A); CD271 (NGFR: nerve growth factor receptor); CD105 (ENG: endoglin); CD31 (PECAM-1: platelet/endothelial cell adhesion molecule-1). CD73 (NT5E: ecto-5′-nucleotidase); CD90 (THY1: Thy-1T-cell antigen); CD146 (MCAM: melanoma cell adhesion molecule); CXCL12 (stromal cell-derived factor 1); ANGPT1 (angiopoietin 1); KITL (KIT ligand); BGLAP (osteocalcin); RUNX2 (runt-related transcription factor 2); SPP1 (osteopontin); ALPL (alkaline phosphatase, liver/bone/kidney). (c–f) Normal samples (n=10); MDS samples (n=12). Black bar: CD271⁺ mesenchymal cells; white bar: CD31⁺ endothelial cells. FDR, false discovery rate. **FDR<0.01; ***FDR<0.001.