ABSTRACT
<p><b>OBJECTIVE</b>To investigate the methods of isolating and identifying human adipose derived EPCs.</p><p><b>METHODS</b>The cells obtained from human lipoaspirates were plated on culture dishes coated with human fibronectin and were cultured in DMEM containing 2% FBS. Cells of passage 2 cultured in EGM-2 (2% FBS) served as the induced cells (experimental group), with cells cultured in DMEM (2% FBS) as the non-induced cells (control group) . Immunofluorescence was used to detect the expression of cell markers, including CD34, vWF and PECAM-1. FACS (fluorescence activated cell sorter) was used to quantitatively analyze the expression rate of cell markers (CD34, CD45, CD133 and PECAM-1). Fluorescence microscope was used to observe the function of taking up DiI-ac-LDL by the induced cells. To determine the ability of forming capillary-like structure in three-dimensional matrices, the induced cells were also cultured in methylcellulose.</p><p><b>RESULTS</b>The induced cells of passage 2 exhibited cobblestone morphology, similar to that of the endothelial cells. In contrast, these morphological changes were not observed in non-induced cells. Immunofluorescence detected expression of vWF, PECAM-1 in induced cells and CD34 in non-induced cells. FACS analysis showed (67.41 +/- 13.35)% of the induced cells expressed PECAM-1 and (6.73 +/- 2.21)% of the non-induced cells expressed PECAM-1 (P < 0.01), while (72.39 +/- 13.45)% of the non-induced cells expressed CD34 and (16.06 +/- 3.86)% of the induced cells expressed CD34 (P < 0.01). Fluorescence microscopy observed the induced cells took up low-density lipoprotein (LDL). The formation of "branch-like" structure confirmed their functional activity.</p><p><b>CONCLUSION</b>EPCs derived from human adipose may serve as another source of seeding cells for vascular tissue engineering.</p>