Proliferative abilities of placenta-derived mesenchymal stem cells at different passages

Bai Jin-ping; Li Xiu-ying; Li Xue; Yang Qi-wei; Liu Ying-nan; Wang Yi-min

doi:10.3969/j.issn.2095-4344.2014.10.018

Abstract：BACKGROUND:The mesenchymal stem cells which are from the placenta have better proliferative potential than the bone marrow mesenchymal stem cells. It is inconclusive, however, whether placenta-derived mesenchymal stem cells at different passages have the same proliferative ability. <br> OBJECTIVE:To analyze the proliferative ability of placenta-derived mesenchymal stem cells. <br> METHODS:Placenta-derived human mesenchymal stem cells were isolated with enzyme digestion, and flow cytometry was used to detect the cellsurface markers. After osteogenic and adipogenic induction, cellproliferation detection was carried out using cellcounting and BrdU analysis. celldoubling time was calculated based on formula. The maximum cellpassage was determined by long term cellculture until the celldied or differentiated. <br> RESULTS AND CONCLUSION:CD44, CD90 and CD105 were highly expressed in placenta-derived mesenchymal stem cells, while CD14, CD34 and CD45 were negatively expressed. After 21 days of adipogenic induction, oil red O staining showed red fat droplets;after 35 days of osteogenic induction, alizarin red staining showed calcium nodules. cellcounting started from passage 1 to 25, and cellnumber reached to 3.5×1011 at passage 15. cellproliferation at passage 5 was stronger with shorter doubling time than that at passages 10 and 15. When cells reached to passage 25, three specimens completely altered their cellmorphology with cobblestone structure, and another two specimens lost adherent features. These findings indicate that placenta-derived mesenchymal stem cells can be long-term subcultured upon to passage 25. Different proliferation capacities are found in different passages of placenta-derived mesenchymal stem cells. The proliferation ability of passage 5 placenta-derived mesenchymal stem cells is stronger than that of passage 10 and 15 cells. Placenta-derived mesenchymal stem cells at passages 0-5 are the important source for stem celltherapy and tissue engineering.