Abstract
Infantile hemangioma, a common benign tumor of infancy, grows quickly in the first year of life, and then regresses slowly to fibrofatty tissue in childhood. The accumulation of fibrofatty tissue in hemangioma involution indicates adipogenesis during this period. Perivascular cells (PCs) from multiple organs display multi-lineage differentiation, including adipogenesis. So we supposed that PCs in hemangioma may contribute to the adipogenesis in the involution. In this study, PDGFR-β (+) PCs was isolated from hemangioma tissue (hemangioma-derived perivascular cells, Hem-PCs) by fluorescence-activated cell sorter. In vitro, Hem-PCs showed fibroblast-like morphology. Immunofluorescence staining and flow cytometry showed Hem-PCs expressed MSCs markers CD105, CD90, CD29 and vimentin, pericyte markers α-SMA and PDGFR-β, stem cell marker CD133, and the adipogenic transcription factor PPAR-γ, but not hematopoietic/endothelial markers CD45, CD34, CD31, and flt-1. In vitro inductions confirmed multi-lineage differentiation of Hem-PCs, especially strong adipogenic potential. Then a murine model was established to observe in vivo differentiation of Hem-PCs by subcutaneous injection of cells/Matrigel compound into nude mice. The results showed Hem-PCs differentiated into adipocytes in vivo. To the best of our knowledge, this is the first study reporting the isolation of multipotential PDGFR-β (+) PCs from hemangioma, and observing their adipogenic differentiation in vivo. PCs may be the cellular basis of adipogenesis in hemangioma involution, and may be the target cells of adipogenic induction to promote hemangioma involution.