April 13, 2009
Research Explores New Avenues For Treating Infertility
Chinese scientists in Shanghai say they have successfully created new egg cells using ovarian stem cells from both young and adult female mice "“ a result that has some people more hopeful than ever about the possibility of using stem cell technology to treat infertility.
Stem cells are undifferentiated cells that have the ability to transform into any kind of specialized cell in the body. In recent years, scientists have invested much research effort in exploring the biochemical mechanisms that cause these cells to differentiate.
In most female mammals the production of reproductive cells known as oocytes, or simply egg cells, occurs while the fetus is still in the mother's womb. Unlike males who continue to produce new sperm throughout their entire life, this means that females are born with a limited number of reproductive cells "“ approximately 2 million in humans.
In this month's issue of Nature Cell Biology, however, Chinese researchers reported that they have discovered a way to generate new egg cells in females.
The process involves first isolating female germline stem cells (FGSC's) from the ovaries of five-day-old and adult female mice, explained researchers from the School of Life Science and Biotechnology at Shanghai Jiao Tong University.
The stem cells were then cultured for more than six months, during which they were labeled with a green fluorescent protein marker from a jellyfish. Finally, the cells were transplanted into the ovaries of infertile females, some eighty percent of which were then able to reproduce through natural mating.
The offspring of the formerly infertile females all carried the green fluorescent marker.
"This new study in mice now suggests that there are also stem cells present in ovaries that can be cultured in a dish, which upon transfer to ovaries can develop into viable eggs and give rise to offspring. This finding, if confirmed independently, could advance (the) understanding of these ovarian stem cells and advance research on female infertility," explained Azim Surani, professor of physiology and reproduction at the Gurdon Institute at Cambridge University.
"The finding may have important implications in regenerative and reproductive medicine," stated the report in Nature.
A researcher in the project, Dr. Ji Wu, believes that the technique would likely work in humans as well, since we share the same kind of FGSC's as mice.
"These cells can be used to extend female reproductive lifespan," said Dr. Wu. "The generation of new oocytes (eggs) could postpone normal or premature ovarian failure, or be used in the treatment of infertility."
The scientists have also expressed hope that the study could also be crucially significant to research in the fields of anti-ageing and regenerative medicine.
Other experts not directly involved in the study have been reserved with their optimism, emphasizing the need for further independent research.
Robin Lovell-Badge of the MRC National Institute for Medical Research in England cautioned: "A lot more work is needed to understand what these new cells really are, and to verify the findings and the claims."
In the U.S., stem cell research has for years been a perennial source of heated public discourse. Even as scientists make astounding progress in the field stem cell technology, many people still question the ethics behind the procurement and use of stem cells in laboratories.
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