ABSTRACT
The aim of this study was to evaluate the homing capabilities of hematopoietic stem/progenitor cells (HSPCs) derived from human placenta tissues (PT). Single cell suspension of human PT was prepared by mechanical method. The expression levels of homing-related adhesion molecules (HRAM) including CD11a, CD49d, CD44, CD49e, CD62L and CD54 on CD34(+) cells and the percentages of CD34(+) cells and their subpopulations in nucleated cells (NC) from fresh human PT, umbilical cord arterial blood (UCAB) and umbilical cord venous blood (UCVB) were detected by using flow cytometry. The results showed that the percentage of CD34(+) cells and CD34(+)CD38(-) cells in placenta were higher than those in UCAB and UCVB. There were no significant difference in percentage of HSPC between UCAB and UCVB. Placenta-derived CD34(+) cells strongly expressed CD11a, CD49d, CD44, CD49e and CD54, among which expression levels of CD49e and CD54 on placenta-derived CD34(+) cells were significantly higher than those on UCAB and UCVB-derived CD34(+) cells. While the percentage of CD34(+)CD62L(+) cells in placenta was only lower than that in UCVB. It is concluded that human placenta is rich in HSPC. Moreover, the expression levels of most HRAM in CD34(+) cells from PT are higher than those from UCAB and UCVB or are close to them. It suggested that HSPCs derived from PT might have stronger homing capabilities than those from UCB.