Experiments which turned mice stem cells into viable eggs used to create offspring via in vitro fertilisation would be fraught with scientific and ethical hurdles in humans, Australian researchers say.

The findings, by Japanese researchers and published in the journal Science Express, showed eggs created from the mice stem cells could be fertilised and transplanted into female mice who gave birth to newborn pups.

But Australian researchers warned that although the findings showed it might be possible to create eggs from human stem cells in the same way, this was not an option at present.

"The study suggests that it may be possible one day to create functioning useable human eggs, called oocytes, but this is not feasible or viable at this time," said Bryce Vissel from the Garvan Institute of Medical Research in Sydney.

Dr Vissel said creating human eggs would remain fraught with scientific challenges and hurdles, including major questions relating to viability, reliability and safety.

He said the real importance of the study was that it could allow more investigation into how human female eggs developed.

Reproductive professor at the University of Adelaide, Robert Norman, said the research offered hope to infertile couples who wanted their own children, but application in humans was still a long way off.

"For many infertile couples, finding they have no sperm or eggs is a devastating blow for which there is no solution other than to not have children, or to use donor gametes," he said.

Using donors was a complex emotional and social issue, Prof Norman said.

"If a person with no gametes could use their own cells to create a child, all the problems would disappear."

See the rest here:
Eggs created from mice stem cells

Published: Oct. 7, 2012 at 1:05 AM

NEW YORK, Oct. 7 (UPI) -- An experimental treatment using skin cells to improve the vision of blind mice may help those with macular degeneration, U.S. researchers say.

Dr. Stephen Tsang of the Columbia University Medical Center in New York and colleagues said the findings suggest induced pluripotent stem cells -- derived from adult human skin cells but with embryonic properties -- could soon be used to restore vision in people with macular degeneration.

"With eye diseases, I think we're getting close to a scenario where a patient's own skin cells are used to replace retina cells destroyed by disease or degeneration," Tsang said in a statement. "It's often said that induced pluripotent stem cells transplantation will be important in the practice of medicine in some distant future, but our paper suggests the future is almost here."

Like embryonic stem cells, induced pluripotent stem cells can develop into any type of cell.

None of these cells has been transplanted into people, but many ophthalmologists said the eye is the ideal testing ground.

"The eye is a transparent and accessible part of the central nervous system, and that's a big advantage," Tsang said. "We can put cells into the eye and monitor them every day with routine non-invasive clinical exams and in the event of serious complications, removing the eye is not a life-threatening event."

The study was published online in advance the print edition of Molecular Medicine

Visit link:
Skin stem cells may help avoid blindness

Published: Oct. 5, 2012 at 3:23 PM

KYOTO, Japan, Oct. 5 (UPI) -- Mouse stem cells have been used to create eggs and sperm producing healthy offspring, a result that may aid human fertility, Japanese scientists say.

If the procedure can be repeated in humans the technique could make it easier for women in their 30s or 40s to have children and could help men and women whose reproductive organs have been damaged by cancer treatments or other causes.

"These studies provide that next level of evidence that in the future fertility could be managed with stem cell intervention," Teresa Woodruff, chief of fertility preservation at Northwestern University's Feinberg School of Medicine, told the Los Angeles Times.

Using stem cells to grow new eggs is particularly important since women are born with a set number and don't make more once they are gone.

The stem cell technique would in effect allow them to turn back their biological clocks, Stanford stem cell researcher Renee A. Reijo Pera said.

"This is a get-them-back strategy," she said.

About 10 percent of American women of childbearing age have trouble becoming or staying pregnant, and more than one-third of infertile couples are dealing with a medical problem in the prospective father, the national Centers for Disease Control and Prevention in Atlanta said.

Dr. Mitinori Saitou and colleagues at Kyoto University detailed how they generated the functional mouse eggs in the journal Science and the same researchers reported doing the same thing with mouse sperm last year.

See more here:
Eggs produced from stem cells

October 5, 2012

Lee Rannals for redOrbit.com Your Universe Online

Japanese scientists reported in the journal Science that they have created life using stem cells made from skin.

The skin cells were used to create eggs which were then fertilized to produce baby mice, who later had their own babies.

The technique has implications that may possibly help infertile couples have children, and maybe could even allow women to overcome menopause.

About one in 10 women of childbearing age face trouble becoming a parent, according to the Centers for Disease Control and Prevention (CDC).

Last year, the scientists at Kyoto University were able to make viable sperm from stem cells. In the more recent study, the team was able to perform a similar accomplishment with eggs.

The researchers used two sources, including those collected from an embryo and skin-like cells, that were reprogrammed into becoming stem cells.

After turning the stem cells into early versions of eggs, they rebuilt an ovary by surrounding the early eggs with other types of supporting cells normally found in an ovary.

They used IVF techniques to collect the eggs, fertilize them with sperm from a male mouse and implant the fertilized egg into a surrogate mother.

Read more:
Healthy Mice Created From Skin Stem Cells In Lab

Research performed on mice to create sperm and eggs from stem cells raises possibilities for humans, with big implications for same-sex couples.

A breakthrough in fertility research lays open the possibility that gay and lesbian couples could someday have children who are completely their own, genetically speaking.

Researchers at Kyoto University in Japan have created eggs from stem cells in mice and used them to produce healthy offspring, NPR reports. They first used embryonic stem cells, then repeated the results stem cells created from adult cells, such as blood or skin. The same team previously created sperm from stem cells. Stem cells can morph into any cell in the body, observed NPR reporter Rob Stein.

If the results from mice could be duplicated in humans a far-off possibility, granted, but scientists say mice are sufficiently similar to humans that it could happen same-sex couples could create their own sperm and eggs and join them to have a child.

There are lots of lesbian and gay couples who would be very excited about the possibility for the first time of being able to have children who are genetically their own, Hank Greely, a bioethicist at Stanford University, told Stein.

Such a breakthrough could also help women who have passed their childbearing years or who are infertile for medical reasons. It raises some questions, though, about the ethics of the procedure, scientists said. For instance, could prospective parents create a child with certain desired traits, and would it be morally acceptable for them to do so?

Its like any other technology, said Daniel Sulmasy, a professor of medicine and ethics at the University of Chicago. Whatever weve done in humankind whether its discovering fire or creating the wheel you can use these things to do lots of good and you can use them immoral ways.

The Kyoto University study was published in this weeks issue of the journal Science.

Read more from the original source:
Fertility Research Opens Possibilities for Gay and Lesbian Couples

By Dennis Normile, ScienceNOW

Want baby mice? Grab a petri dish. After producing normal mouse pups last year using sperm derived from stem cells, a Kyoto University team of researchers has now accomplished the same feat using eggs created the same way. The study may eventually lead to new ways of helping infertile couples conceive.

This is a significant achievement that I believe will have a sustained and long-lasting impact on the field of reproductive cell biology and genetics, says Amander Clark, a stem cell biologist at University of California, Los Angeles.

The stem cells in both cases are embryonic stem (ES) cells and induced pluripotent stem (iPS) cells. The former are taken from embryos and the latter are adult tissue cells that are reprogrammed to act like stem cells. In theory, both can produce all of the bodys cell types, yet most researchers have been unable to turn them into germ cells, precursors of sperm and eggs.

The Kyoto group, led by stem cell biologist Mitinori Saitou, found a process that works. As with the sperm, the group started with ES and iPS cells and cultured them in a cocktail of proteins to produce primordial germ cell-like cells. To get oocytes, or precursor egg cells, they then mixed the primordial cells with fetal ovarian cells, forming reconstituted ovaries that they then grafted onto natural ovaries in living mice. Four weeks and 4 days later, the primordial germ cell-like cells had developed into oocytes. The team removed the ovaries, harvested the oocytes, fertilized them in vitro, and implanted the resulting embryos into surrogate mothers. About 3 weeks later, normal mouse pups were born, the researchers report online today in Science.

It is remarkable that one can produce oocytes capable of sustaining complete development starting with embryonic stem cells, says Davor Solter, a developmental biologist at Singapores Institute of Medical Biology. Clark adds that the immediate impact of the work will be on understanding the molecular mechanisms involved in forming germ cells. Saitou says that with a bit more progress in understanding the complex interactions at work, they may be able to coax the cells through the entire oocyte development process in a lab dish. If successful, we may be able to skip the grafting, he says.

Further in the future, the technique could lead to a new tool for treating infertility. This study has provided the critical proof of principle that oocytes can be generated from induced pluripotent stem cells, Clark says. If applied to humans, it could lead to the ability to create oocytes from iPS cells taken from infertile women. But Saitou cautions that moving on to human research will require resolving thorny ethical issues and technical difficulties. Solter says that at the extreme, the new approach could lead to the production of human embryos from cell lines and tissue samples. Still, he notes, defining the status of such parentless human embryos and the biological, ethical, and legal issues they will raise defies the imagination.

This story provided by ScienceNOW, the daily online news service of the journal Science.

The rest is here:
Dish-Grown Sperm and Eggs Produce Mouse Pups

And rightly so: stem-cell scientists have derived many types of cells from stem-cell precursors, but have in the past struggled with sex cells. The research by a team at Kyoto University provides a powerful model into mammalian development and infertility, but it is still a long way off from being used in human therapy.

Despite this fact, it did not stop the headlines in some of today's press screaming that infertile women could one day become pregnant by creating eggs from stem cells.

Evelyn Telfer, a reproductive biologist at the University of Edinburgh, told me this study has no clinical application to humans whatsoever because the tissue used in this study were all foetal and not adult cells.

Mitinori Saitou led a team using foetal mouse tissue from embryos or skin cells to create stem cells. Those stem cells were then genetically reprogrammed to become germ cells egg precursor cells.

These were then given a cocktail of "factors" to support their growth into mature eggs. The eggs were fertilised by IVF in the lab and then implanted into surrogate mice. Three baby mice were born and grew into fertile adults.

The fact that artificially manufactured eggs have gone on to produce healthy mice which are fertile is absolutely astounding and a great step forward for science. The results are published in the journal, Science.

But there are huge differences between human and mouse cells, not to mention the medical and ethical issues surrounding human ovarian tissue to culture cells.

Further clinical trials would be necessary using adult mouse cells first before we can start projecting that we can manufacture babies, and scientists need to learn so much more about how women form eggs.

So while this is major contribution to the field of reproductive biology, the study is not a ready-made cure for women with fertility problems.

The rest is here:
Stem cells: of mice and women?