Vessel resident calcifying progenitor cells are mesenchymal but not hematopoietic.

<p>(A) FACS of arterial cells from GFP–BMT Apoe^−/− mice. GFP⁺ cells were negative for Lineage antibody cocktail targets. GFP⁺Lin⁻Sca-1⁺/PDGFRα⁺ or GFP⁺Lin⁻Sca-1⁺/PDGFRα⁻ cells expressed CD29 or CD106 (<i>n</i> = 10, performed in triplicate). (B) Schematic of osteoblast, adipocyte, and chondrocyte inductions from calcifying progenitor cells. Cells were stained with Alizarin Red S after 14 d of differentiation; bars: 1 mm. Oil Red O staining 28 d after differentiation; bars: 50 µm. Safranin O staining 28 d after differentiation; bars: 50 µm. (C) Adipocyte-related genes and chondrocyte-related genes were upregulated in Sca-1⁺ cells (Sca-1⁺/PDGFRα⁺, Sca-1⁺/PDGFRα⁻) under each differentiation condition.