Scientists in Japan have discovered that cells taken from menstrual blood can be cultivated in the lab and used like stem cells to repair damaged heart tissue.

The initial results of the work were published last week in the journal Stem Cells. The study was the work of corresponding author Dr Shunichiro Miyoshi, a cardiologist at Keio University School of Medicine, in Tokyo, and colleagues, including scientists from the National Research Institute for Child Health and Development in Tokyo, Tokyo Women’s Medical University, and Kanazawa University.

Stem cells can be used to repair damaged tissue because they have the potential to become any cell in the body.

However, while scientists are developing numerous uses for stem cells, getting hold of them is not easy and many harvesting techniques involve invasive procedures.

Miyoshi and colleagues discovered that menstrual blood contains precursos cells that can be used to develop cardiac stem-cell therapeutic material, and these cells appear to have greater potential for this than cells from bone marrow.

Nine women volunteered to donate menstrual blood from which the scientists harvested the precursor cells, called mesenchymal cells (MMCs) and cultivated them for a month.

After being put together in a culture with cells from the hearts of rats, about 20 per cent of MMCs began beating spontaneously and eventually formed sheets of heart muscle tissue.

According to a report by AFP news agency, this success rate is about 100 times higher than the 0.2 to 0.3 per cent of stem cells derived from human bone marrow.

The MMCs showed many of the signs typical of cardiomyocytes, the precursor cells to heart muscle cells.

For instance, up to 32 per cent of them tested positive for troponin-I (a heart muscle protein), and they multiplied for 28 generations, on average, without affecting their potential to produce heart muscle cells.

Another set of experiments showed that live rats that had suffered heart attacks improved after being implanted with the MMCs. The researchers saw that the implanted MMCs gave rise to cardiomyocytes in the rats’ hearts and decreased the myocardial infarction (MI) area.

The researchers concluded that:

“MMCs appear to be a potential novel, easily accessible source of material for cardiac stem cell-based therapy.”

Miyoshi told AFP yesterday, Thursday 24th April, that one day women could use their menstrual blood for their own treatment. This would overcome the major problem of immune system rejection.

Another useful application could be to use menstrual blood to stockpile cells with a range of matching HLAs, human leukocyte antigens, important immune system agents.

He also suggested, because the MMCs have the potential to develop into muscle cells, that perhaps another application could be to treat muscular dystrophy, a range of genetic diseases that destroy muscle tissue.

Miyoshi told AFP that he was not entirely happy with the results of the experiment on the rats’ hearts. He wants to find out what exactly happens to convert the MMCs into heart cells.

“I guess this can’t be ready for clinical use yet,” he said.

Another study by US researchers, reported yesterday in Medical News Today, also showed how multipotential stem cells could be provided by menstrual blood.

“Novel Cardiac Precursor-Like Cells from Human Menstrual Blood-Derived Mesenchymal Cells.”

Naoko Hida, Nobuhiro Nishiyama, Shunichiro Miyoshi, Shinichiro Kira, Kaoru Segawa, Taro Uyama, Taisuke Mori, Kenji Miyado, Yukinori Ikegami, ChangHao Cui, Tohru Kiyono, Satoru Kyo, Tatsuya Shimizu, Teruo Okano, Michiie Sakamoto, Satoshi Ogawa, Akihiro Umezawa.

Stem Cells Express, first published online April 17, 2008.

DOI:10.1634/stemcells.2007-0826

Click here for Abstract.

Sources: Journal Abstract, AFP news agency.

Written by: Catharine Paddock, PhD