Proliferation and chondrogenic differentiation potential of menstrual blood- and bone marrow-derived stem cells in two-dimensional culture.

Menstrual blood is easily accessible, renewable, and inexpensive source of stem cells. In this study, we investigated the chondrogenic differentiation potential of menstrual blood-derived stem cells (MenSCs) compared with that of bone marrow-derived stem cells (BMSCs) in two-dimensional culture. Following characterization of isolated cells, the potential for chondrogenic differentiation of MenSCs and BMSCs was evaluated by immunocytochemical and molecular experiments. MenSCs were strongly positive for mesenchymal stem cell markers in a manner similar to that of BMSCs. In contrast to BMSCs, MenSCs exhibited marked expression of OCT4, and higher proliferative capacity. Differentiated MenSCs showed strong immunoreactivity to a monoclonal antibody against Collagen type 2, in a pattern similar to BMSCs. Accumulation of proteoglycans in differentiated MenSCs was also comparable with that in differentiated BMSCs. However, the mRNA expression patterns as judged by RT-PCR of chondrogenic markers such as Collagen 2A1, Collagen 9A1 and SOX9 in MenSCs were different from those in BMSCs. Given these findings, MenSCs appear to be a unique stem cell population with higher proliferation than and comparable chondrogenic differentiation ability to BMSCs in two-dimensional culture. Much quantitative studies at the molecular level may elucidate the reasons for the observed differences in MenSCs and BMSCs.