Characteristics of Multipotent Mesenchymal Stromal Cells from Human Terminal Placenta.

Cell cultures isolated by the enzymatic method from the terminal placenta amnion consist mainly from epithelial cells, expressing cytokeratin-7, CD90, and CD73, are characterized by high viability and low proliferative potential. Adhesive cultures of umbilical (Wharton's jelly) cells, despite the fibroblast-like shape of the cells and expression of surface markers, intrinsic to mesenchymal stromal cells, are also characterized by high heterogeneity during the initial stages of culturing, judging by an appreciable share of cytokeratin-expressing cells. The terminal placenta chorionic villi can be a source of cells with the most typical morphology and immunophenotypical profile of the resident multipotent mesenchymal stromal cells, which retain high viability in vitro and have a high proliferative potential.

Subpopulation composition and activation of T lymphocytes during coculturing with mesenchymal stromal cells in medium with different O(2) content.

The concentration of O(2) during coculturing practically did not affect the subpopulation composition of T lymphocytes (CD3(+)/CD4(+), CD3(+)/CD8(+), CD3(+)/CD16(+)/CD56(+) T cells) under conditions of PHA-induced activation. Coculturing with mesenchymal stromal cells (MSC) led to a significant decrease in the ratio of lymphocytes carrying activation markers (CD3(+)/CD25(+) and CD3(+)/HLA-DR(+)) and increase in the number of CD3(+)/CD16(+)/CD56(+) T cells. The percent of activated HLA-DR(+) T cells in a heterotypic culture with MSC at 5% O(2) was much lower than that observed under normal conditions of culturing (20% O(2)).

Low level of O2 inhibits commitment of cultured mesenchymal stromal precursor cells from the adipose tissue in response to osteogenic stimuli.

Mesenchymal stromal precursor cells from human lipoaspirate (lMSC) cultured at 5% O(2) formed 50% less mineralized matrix in response to osteogenic induction than cells cultured under standard conditions (20% O(2)). After lMSC percultured at 5% O(2) were transferred to normoxic conditions (20% O(2)), they produced the same amount of matrix as lMSC permanently cultured at 20% O(2). Hence, hypoxia inhibited the commitment of lMSC under the effect of osteogenic stimuli, which can be important in reparative and regenerative medicine.