Functional Implications of CD34 Expression in Human Adipose-Derived Stem/Progenitor Cells

CD34 is frequently used as a marker of adipose-derived stem/stromal/progenitor cells (ASCs). However, CD34 expression in human ASCs (hASCs) decreases over time in culture, and the implications of this remain unclear. In this study, we sorted shortly-cultured hASCs into CD34+ and CD34− fractions and compared their biological functions. Results indicated that CD34+ hASCs were more proliferative and had a greater ability to form colonies. In contrast, CD34− cells showed a greater ability for differentiation into adipogenic and osteogenic lineages. Both CD34+ and CD34− cells showed similar abilities in migration and capillary formation in response to growth factors. Expression levels of endothelial progenitor markers (Flk-1, FLT1, and Tie-2) were higher in CD34+ cells, whereas those of pericyte markers (CD146, NG2, and α-smooth muscle actin) were higher in CD34− cells. Both CD34+ and CD34− cells showed similar expression levels of vascular endothelial growth factor and hepatocyte growth factor, although hypox...