Comparison of cell proliferation, apoptosis, cellular morphology and ultrastructure between human umbilical cord and placenta-derived mesenchymal stem cells.

Research in mesenchymal stem cells (MSCs) is mainly focused on applications for treatments of brain and spinal cord injury as well as mechanisms underlying effects of MSCs. However, due to numerous limitations, there is little information on selection of appropriate sources of MSCs for transplantation in clinical applications. Therefore, in this study we compared various properties of human umbilical cord-derived MSCs (HUCMSCs) with human placenta-derived MSCs (HPDMSCs), including cell proliferation, apoptosis, cellular morphology, ultrastructure, and their ability to secrete various growth factors (i.e. vascular endothelial growth factor, insulin-like growth factors-1, and hepatocyte growth factor), which will allow us to select appropriate MSC sources for cellular therapy. Cell culture, flow cytometry, transmission electron microscope (TEM) and atomic force microscope (AFM) were used for assessment of HUCMSCs and HPDMSCs. Results showed that the two types of cells appeared slightly different when they were observed under AFM. HUCMSCs appeared more fibroblast-like, whereas HPDMSCs appeared as large flat cells. HUCMSCs had higher proliferative rate and lower rate of apoptosis than HPDMSCs (p<0.05). However, HPDMSCs secreted more of the three growth factors than HUCMSCs (p<0.05). Results of TEM revealed that the two types of MSCs underwent active metabolism and had low degree of differentiation, especially HUCMSCs. Results of AFM showed that HUCMSCs had stronger ability of mass transport and cell migration than HPDMSCs. However, HPDMSCs displayed stronger adhesive properties than HUCMSCs. Our findings indicate that different sources of MSCs have different properties, and that care should be taken when choosing the appropriate sources of MSCs for stem cell transplantation.