Comparison of human first and third trimester placental mesenchymal stem cell

Placenta mesenchymal stem cells (PMSCs) have the characteristic features of stem cells including renewability in vitro, surface expression, differentiation potency and ability to adhere to the culture surface. PMSCs expressed genes are normally found in the embryonic tissues before the onset of gastrulation, indicating multipotency. However, the stemness can depend on the stages of the placenta from which the cells were isolated. PMSCs were isolated from two different stages of placenta for comparison, that is the first and third trimesters. Both sets had very similar patterns of surface expression as CD44, CD73, CD90 and CD105, and of self renewability in vitro. Expressions of pluripotency-coupled genes were also confirmed in both sets of cells; however, there was a significant difference in the expression levels: fPMSC (mesenchymal stem cells isolated from the first trimester human placenta) being 2-11-fold higher than tPMSC (mesenchymal stem cells isolated from the third trimester human placenta). Possibly due to the difference in the expression levels of the pluripotency-related genes, induction of genes specific to the ectodermal tissues were more prominent in fPMSC than tPMSC after induced differentiation.