Isolation and in vitro characterization of human dermal microvascular pericytes

Pericytes cover the abluminal surface of capillaries and venules and are th ought to play an important role in microvascular regulation and pathology. The purpose of this study was to isolate and characterize human dermal micr ovascular pericytes (HDMPC), a minor cell type in the skin but a relatively easily obtainable human source of tissue. We developed and compared two pr ocedures that differed in the preselection method. Isolation of dermal micr ovessel fragments from neonatal foreskins by trypsin digestion was followed by mechanical release of subepidermal tissue, collagenase treatment, and s ieving through 100- and 30-mum meshes. After subcultivation, pericytes were preselected either by isolation of outgrowing capillary fragments or by 3G 5-coupled magnetic beads. Pericytes were selected finally by cultivation of single cells in endothelial cell-conditioned media. Cultured HDMPC were se en to be large and well spread with irregular edges and prominent stress fi bers. They lack contact inhibition, are positive for 3G5 antigen, alpha -sm ooth muscle actin, and vimentin, and are negative for the endothelial cell marker CD31, diI-acetylated low-density lipoprotein uptake, cytokeratin 5, 6, and 18, and S100 protein. Using both preselection methods, we could esta blish purified cell cultures of HDMPC. The results of these studies represe nt the first report of HDMPC isolation, (C) 2001 Academic Press.