CD146⁺ perivascular cells induce Notch activation in hematopoietic cells. (A) Immunocytochemical staining for Jagged-1 (JAG1, red), CD146 (green) and nuclei (DAPI, blue) performed on fat-derived CD146⁺ perivascular cells and MSCs (original magnification, ×20). White arrows indicate clusters of cells within the MSC that coexpress JAG1 and CD146. (B) Western blot analysis showing significantly higher expression of Jagged-1 in CD146⁺ perivascular cells compared with MSCs derived from fat. (C) qPCR analysis revealed that fat-derived MSCs and CD146⁺ perivascular cells express multiple Notch ligands. (D-E) Quantification of (D) CD45⁺ and (E) CD34⁺ hematopoietic and progenitor cells with activated Notch pathway (CD45⁺NICD⁺) after 1 week of coculture with fat or FBM-derived CD146⁺ perivascular cells, MSCs, and CD146⁻ cells (n = 3 independent experiments, n = 40 random fields analyzed; ***P < .0001). Data are presented as mean ± SEM.