Distinct molecular basis for endothelial differentiation: Gene expression profiles of human mesenchymal stem cells versus umbilical vein endothelial cells

The capacity for endothelial differentiation has been described in mesenchymal stem cells (MSC) from human bone marrow. To identify genes associated with the endothelial differentiation potential of this cell-type, and search for the optimal regulatory factors, the expression profile of MSC was compared with cDNA from primary human umbilical vein endothelial cells as controls, using cDNA chips with 4096 genes. The data were corroborated by quantitative PCR, Western blotting, and immunocytochemistry. Among the 3948 effective genes, ∼84% (3321) were co-expressed in both cell-types, and 627 were differentially expressed more than twofold in MSC versus EC. MSC highly expressed numerous stem-cell-like genes. Early development genes of endothelial cells, though not up-regulated, had a high expression in MSC, such as EDF1, MDG1, and EDG2. In contrast, mature endothelial growth and signal pathway genes, like VEGF, CXCR4, and CTNNB1, were down-regulated in MSC. In conclusion, human MSC have a distinct molecular basis for endothelial differentiation.