Menstrual Blood Stem Cells Part 2

Tokyo, Japan -

It was previously reported by the company Medistem (mdsm.ob) that a population of multipotent stem cells exist in menstrual blood.  These cells, which Medistem termed "endometrial regenerative cells" appear to possess some of the properties of mesenchymal stem cells, such as expression of CD90 and CD105, as well as are capable of differentiating into 9 major tissues of the body.

In a recent publication (Hida et al. Novel Cardiac Precursor-Like Cells from Human Menstrual Blood-Derived Mesenchymal Cells. Stem Cells. 2008 Apr 17) a Japanese group confirmed the results of Medistem by describing a stem cell population with identical phenotypic characteristics and some similar functional characteristics.

The researchers found that the menstrual derived stem cells can be induced into cardiomyocytes in vitro, and that these cardiomyocytes can be made to spontaneously contract in tissue culture.  This is similar to what Medistem published, except that Medistem also demonstrated differentiation into neuronal, hepatic, pancreatic, pulmonary, and several other types of tissues.  In contrast, the Japanese group decided to further develop the cardiac differentiation work.  Having demonstrated conversion to cardiomyocytes, the scientists then administered the cells in vivo in an animal model of cardiac infarction.  Functional improvement was demonstrated in animals treated with menstrual derived stem cells but not control cells.

Theoretically it would make sense that menstrual blood contains stem cell populations.  Given the extraordinarily high amount of tissue turnover that occurs in the female endometrium every month, it may be expected that cell populations exist which both stimulate angiogenesis, as well as promote tissue outgrowth.  The fact that the menstrual derived stem cells are similar phenotypically to mesenchymal stem cells suggests that these cells may be developed as an alternative to the bone marrow derived mesenchymal stem cells that Osiris Therapeutics is using for its clinical trials.  One possible advantage of mesenchymal stem cells derived from the menstrual blood, such as Medistem's ERC population is that these cells secrete higher amounts of angiogenic cytokines and matrix metalloproteases and therefore could theoretically be superior for treatment of ischemic conditions.