Archive for the ‘Skin Stem Cells’ Category

(CBS/AP) Stem cells in young women's ovaries are capable of producing new eggs, according to a new study. The findings challenge 60 years of dogma that women are born with all the eggs they'll ever have.

PICTURES: Human eggs: 9 fascinating facts

For the study, published in the Feb. 26 issue of Nature Medicine and led by Jonathan Tilly of Massachusetts General Hospital, researchers examined healthy human ovaries donated by 20-something Japanese women who were undergoing a sex-change operation. The researchers fished out stem cells by searching for a protein found only on the surface of stem cells. The researchers then injected those stem cells into pieces of human ovary, transplanting the tissue under the skin of mice, to provide the tissue with a nourishing blood supply.

What happened? New egg cells formed within two weeks.

That's still a long way from showing they'll mature into usable, quality eggs, David Albertini, director of the University of Kansas' Center for Reproductive Sciences, cautioned.

Still, these findings could lead to better treatments for women left infertile because of disease - or simply because they're getting older.

"Our current views of ovarian aging are incomplete. There's much more to the story than simply the trickling away of a fixed pool of eggs," Tilly, who has long hunted these cells in a series of controversial studies, said.

Tilly's previous work has drawn skepticism, and independent experts urged caution about the latest findings, so the next step is to see whether other laboratories can verify the work. If the findings are confirmed, then it would take years of additional research to learn how to use the cells, Teresa Woodruff, fertility preservation chief at Northwestern University's Feinberg School of Medicine, said.

"This is experimental," Dr. Avner Hershlag, chief of the Center for Human Reproduction at North Shore-LIJ Health System in Manhasset, N.Y., told HealthDay. He said the study is "exciting" but emphasized the work is still very preliminary. "This is a beginning of perhaps something that could bring in new opportunities, but it's going to be a long time in my estimation until clinically we'll be able to actually have human eggs created from stem cells that make babies."

Still, even a leading critic said such research may help dispel some of the enduring mystery surrounding how human eggs are born and mature.

"This is going to spark renewed interest, and more than anything else it's giving us some new directions to work in," Albertini said. While he has plenty of questions about the latest work, "I'm less skeptical," he said.

Scientists have long taught that all female mammals are born with a finite supply of egg cells, called ooctyes, that runs out in middle age. Tilly, Mass General's reproductive biology director, first challenged that notion in 2004, reporting that the ovaries of adult mice harbor some egg-producing stem cells. Recently, Tilly noted, a lab in China and another in the U.S. also have reported finding those rare cells in mice.

More work is needed to tell exactly what these cells are, cautioned reproductive biologist Kyle Orwig of the University of Pittsburgh Medical Center, who has watched Tilly's work with great interest.

But if they're really competent stem cells, Orwig asked, then why would women undergo menopause? Indeed, something so rare wouldn't contribute much to a woman's natural reproductive capacity, added Northwestern's Woodruff.

Tilly argues that using stem cells to grow eggs in lab dishes might one day help preserve cancer patients' fertility. Today, Woodruff's lab and others freeze pieces of girls' ovaries before they undergo fertility-destroying chemotherapy or radiation. They're studying how to coax the immature eggs inside to mature so they could be used for in vitro fertilization years later when the girls are grown. If that eventually works, Tilly says stem cells might offer a better egg supply.

See the article here:
Study: Stem cells in ovaries may grow new eggs

For 60 years, doctors have believed women were born with all the eggs they'll ever have. Now Harvard scientists are challenging that dogma, saying they've discovered the ovaries of young women harbour very rare stem cells capable of producing new eggs.

If the report is confirmed, harnessing those stem cells might one day lead to better treatments for women left infertile because of disease — or simply because they're getting older.

"Our current views of ovarian aging are incomplete. There's much more to the story than simply the trickling away of a fixed pool of eggs," said lead researcher Jonathan Tilly of Harvard's Massachusetts General Hospital, who has long hunted these cells in a series of controversial studies.

Tilly's previous work drew fierce skepticism, and independent experts urged caution about the latest findings.

A key next step is to see whether other laboratories can verify the work. If so, then it would take years of additional research to learn how to use the cells, said Teresa Woodruff, fertility preservation chief at Northwestern University's Feinberg School of Medicine.

Still, even a leading critic said such research may help dispel some of the enduring mystery surrounding how human eggs are born and mature.

"This is going to spark renewed interest, and more than anything else it's giving us some new directions to work in," said David Albertini, director of the University of Kansas' Center for Reproductive Sciences. While he has plenty of questions about the latest work, "I'm less skeptical," he said.

Scientists have long taught that all female mammals are born with a finite supply of egg cells, called ooctyes, that runs out in middle age. Tilly, Mass General's reproductive biology director, first challenged that notion in 2004, reporting that the ovaries of adult mice harbour some egg-producing stem cells. Recently, Tilly noted, a lab in China and another in the U.S. also have reported finding those rare cells in mice.

But do they exist in women? Enter the new work, reported Sunday in the journal Nature Medicine.

First Tilly had to find healthy human ovaries to study. He collaborated with scientists at Japan's Saitama Medical University, who were freezing ovaries donated for research by healthy 20-somethings who underwent a sex-change operation.

Egg quality questions

Tilly also had to address a criticism: How to tell if he was finding true stem cells or just very immature eggs. His team latched onto a protein believed to sit on the surface of only those purported stem cells and fished them out. To track what happened next, the researchers inserted a gene that makes some jellyfish glow green into those cells. If the cells made eggs, those would glow, too.

"Bang, it worked — cells popped right out" of the human tissue, Tilly said.

Researchers watched through a microscope as new eggs grew in a lab dish. Then came the pivotal experiment: They injected the stem cells into pieces of human ovary. They transplanted the human tissue under the skin of mice, to provide it a nourishing blood supply.

Within two weeks, they reported telltale green-tinged egg cells forming.

That's still a long way from showing they'll mature into usable, quality eggs, Albertini said.

And more work is needed to tell exactly what these cells are, cautioned reproductive biologist Kyle Orwig of the University of Pittsburgh Medical Center, who has watched Tilly's work with great interest.

But if they're really competent stem cells, Orwig asked, then why would women undergo menopause? Indeed, something so rare wouldn't contribute much to a woman's natural reproductive capacity, added Northwestern's Woodruff.

Tilly argues that using stem cells to grow eggs in lab dishes might one day help preserve cancer patients' fertility. Today, Woodruff's lab and others freeze pieces of girls' ovaries before they undergo fertility-destroying chemotherapy or radiation. They're studying how to coax the immature eggs inside to mature so they could be used for in vitro fertilization years later when the girls are grown. If that eventually works, Tilly says stem cells might offer a better egg supply.

Further down the road, he wonders if it also might be possible to recharge an aging woman's ovaries.

The new research was funded largely by the U.S. National Institutes of Health. Tilly co-founded a company, OvaScience Inc., to try to develop the findings into fertility treatments.

See the original post:
Egg-producing stem cells found in women's ovaries

M I Walker / Getty Images

Are women born with all the eggs they'll ever have? Harvard scientists say possibly not. Their discovery of stem cells in human ovaries could someday help infertile women produce new eggs.

For 60 years, doctors have believed women were born with all the eggs they’ll ever have. Now Harvard scientists are challenging that dogma, saying they’ve discovered the ovaries of young women harbor very rare stem cells capable of producing new eggs.

If Sunday’s report is confirmed, harnessing those stem cells might one day lead to better treatments for women left infertile because of disease — or simply because they’re getting older.

“Our current views of ovarian aging are incomplete. There’s much more to the story than simply the trickling away of a fixed pool of eggs,” said lead researcher Jonathan Tilly of Harvard’s Massachusetts General Hospital, who has long hunted these cells in a series of controversial studies.

Tilly’s previous work drew fierce skepticism, and independent experts urged caution about the latest findings.

A key next step is to see whether other laboratories can verify the work. If so, then it would take years of additional research to learn how to use the cells, said Teresa Woodruff, fertility preservation chief at Northwestern University’s Feinberg School of Medicine.

Still, even a leading critic said such research may help dispel some of the enduring mystery surrounding how human eggs are born and mature.

“This is going to spark renewed interest, and more than anything else it’s giving us some new directions to work in,” said David Albertini, director of the University of Kansas’ Center for Reproductive Sciences. While he has plenty of questions about the latest work, “I’m less skeptical,” he said.

Scientists have long taught that all female mammals are born with a finite supply of egg cells, called ooctyes, that runs out in middle age. Tilly, Mass General’s reproductive biology director, first challenged that notion in 2004, reporting that the ovaries of adult mice harbor some egg-producing stem cells. Recently, Tilly noted, a lab in China and another in the U.S. also have reported finding those rare cells in mice.

But do they exist in women? Enter the new work, reported Sunday in the journal Nature Medicine.

First Tilly had to find healthy human ovaries to study. He collaborated with scientists at Japan’s Saitama Medical University, who were freezing ovaries donated for research by healthy 20-somethings who underwent a sex-change operation.

Tilly also had to address a criticism: How to tell if he was finding true stem cells or just very immature eggs. His team latched onto a protein believed to sit on the surface of only those purported stem cells and fished them out. To track what happened next, the researchers inserted a gene that makes some jellyfish glow green into those cells. If the cells made eggs, those would glow, too.

“Bang, it worked — cells popped right out” of the human tissue, Tilly said.

Researchers watched through a microscope as new eggs grew in a lab dish. Then came the pivotal experiment: They injected the stem cells into pieces of human ovary. They transplanted the human tissue under the skin of mice, to provide it a nourishing blood supply. Within two weeks, they reported telltale green-tinged egg cells forming.

That’s still a long way from showing they’ll mature into usable, quality eggs, Albertini said.

And more work is needed to tell exactly what these cells are, cautioned reproductive biologist Kyle Orwig of the University of Pittsburgh Medical Center, who has watched Tilly’s work with great interest.

But if they’re really competent stem cells, Orwig asked, then why would women undergo menopause? Indeed, something so rare wouldn’t contribute much to a woman’s natural reproductive capacity, added Northwestern’s Woodruff.

Tilly argues that using stem cells to grow eggs in lab dishes might one day help preserve cancer patients’ fertility. Today, Woodruff’s lab and others freeze pieces of girls’ ovaries before they undergo fertility-destroying chemotherapy or radiation. They’re studying how to coax the immature eggs inside to mature so they could be used for in vitro fertilization years later when the girls are grown. If that eventually works, Tilly says stem cells might offer a better egg supply.

Further down the road, he wonders if it also might be possible to recharge an aging woman’s ovaries.

The new research was funded largely by the National Institutes of Health. Tilly co-founded a company, OvaScience Inc., to try to develop the findings into fertility treatments.

Continued here:
Rethinking Infertility: Study Shows Women Have Egg-Producing Stem Cells

24-01-2012 11:14 Skincare Guru Sonya Dakar (www.sonyadakarskinclinic.com) on Good Morning America (GMA) Bizarre Beauty Segment showcases her Snake Venom Facial Treatment at the Sonya Dakar Skin Clinic in Beverly Hills utilizing her new NutraSphere Stem Cell Transformer. Made with synthetic snake venom the Stem Cell Transfomer works to inhibit muscle contraction giving skin a natural botox-like effect on the skin. Learn more at http://www.sonyadakarskinclinic.com

See the original post:
Sonya Dakar Snake Venom Facial on Good Morning America - with NutraSphere Stem Cell Transformer - Video

An experiment that has produced human eggs from stem cells could be a boon for women desperate to have a baby, scientists claim.

New research has swept away the belief women only have a limited stock of eggs and replaces it with the theory the supply is continuously replenished from precursor cells in the ovary.

'The prevailing dogma in our field for the better part of the last 50 or 60 years was that young girls at birth were given a bank account of eggs at birth that's not renewable,' says Jonathan Tilly, director of the Vincent Center for Reproductive Biology at Massachusetts General Hospital, who led the research.

'As they become mature and become a woman, they use those eggs up (and) the ovaries will fail when they enter menopause.'

Tilly first challenged the 'bank account' doctrine eight years ago, suggesting female mammals continue producing egg-making cells into adulthood rather than from a stock acquired at birth.

His theory ran into a firestorm.

Other scientists challenged the accuracy of his experiments or dismissed their conclusions as worthless, given they were only conducted on lab mice.

But Tilly says the new work not only confirms his controversial idea, it takes it further.

In it, his team isolated egg-producing stem cells in human ovaries and then coaxed them into developing oocytes, as eggs are called.

Building on a feat by Chinese scientists, they pinpointed the oocyte stem cells by using antibodies which latched onto a protein 'handle' located on the side of these cells.

The team tagged the stem cells with a fluorescent green protein - a common trick to help figure out what happens in lab experiments.

The cells were injected into biopsied human ovarian tissue which was then grafted beneath the skin of mice.

Within 14 days, the graft had produced a budding of oocytes. Some of the eggs glowed with the fluorescent tag, proving that they came from the stem cells. But others did not, which suggested they were already present in the tissue before the injection.

Tilly said 'the hairs were standing up on my arm' when he saw time-elapse video showing the eggs maturing in a lab dish.

Further testing needs to be done but Tilly says the work could be far-reaching.

More here:
Human eggs produced from stem cells

For 60 years, doctors have believed women were born with all the eggs they'll ever have. Now Harvard scientists are challenging that dogma, saying they've discovered the ovaries of young women harbour very rare stem cells capable of producing new eggs.

If the report is confirmed, harnessing those stem cells might one day lead to better treatments for women left infertile because of disease — or simply because they're getting older.

"Our current views of ovarian aging are incomplete. There's much more to the story than simply the trickling away of a fixed pool of eggs," said lead researcher Jonathan Tilly of Harvard's Massachusetts General Hospital, who has long hunted these cells in a series of controversial studies.

Tilly's previous work drew fierce skepticism, and independent experts urged caution about the latest findings.

A key next step is to see whether other laboratories can verify the work. If so, then it would take years of additional research to learn how to use the cells, said Teresa Woodruff, fertility preservation chief at Northwestern University's Feinberg School of Medicine.

Still, even a leading critic said such research may help dispel some of the enduring mystery surrounding how human eggs are born and mature.

"This is going to spark renewed interest, and more than anything else it's giving us some new directions to work in," said David Albertini, director of the University of Kansas' Center for Reproductive Sciences. While he has plenty of questions about the latest work, "I'm less skeptical," he said.

Scientists have long taught that all female mammals are born with a finite supply of egg cells, called ooctyes, that runs out in middle age. Tilly, Mass General's reproductive biology director, first challenged that notion in 2004, reporting that the ovaries of adult mice harbour some egg-producing stem cells. Recently, Tilly noted, a lab in China and another in the U.S. also have reported finding those rare cells in mice.

But do they exist in women? Enter the new work, reported Sunday in the journal Nature Medicine.

First Tilly had to find healthy human ovaries to study. He collaborated with scientists at Japan's Saitama Medical University, who were freezing ovaries donated for research by healthy 20-somethings who underwent a sex-change operation.

Egg quality questions

Tilly also had to address a criticism: How to tell if he was finding true stem cells or just very immature eggs. His team latched onto a protein believed to sit on the surface of only those purported stem cells and fished them out. To track what happened next, the researchers inserted a gene that makes some jellyfish glow green into those cells. If the cells made eggs, those would glow, too.

"Bang, it worked — cells popped right out" of the human tissue, Tilly said.

Researchers watched through a microscope as new eggs grew in a lab dish. Then came the pivotal experiment: They injected the stem cells into pieces of human ovary. They transplanted the human tissue under the skin of mice, to provide it a nourishing blood supply.

Within two weeks, they reported telltale green-tinged egg cells forming.

That's still a long way from showing they'll mature into usable, quality eggs, Albertini said.

And more work is needed to tell exactly what these cells are, cautioned reproductive biologist Kyle Orwig of the University of Pittsburgh Medical Center, who has watched Tilly's work with great interest.

But if they're really competent stem cells, Orwig asked, then why would women undergo menopause? Indeed, something so rare wouldn't contribute much to a woman's natural reproductive capacity, added Northwestern's Woodruff.

Tilly argues that using stem cells to grow eggs in lab dishes might one day help preserve cancer patients' fertility. Today, Woodruff's lab and others freeze pieces of girls' ovaries before they undergo fertility-destroying chemotherapy or radiation. They're studying how to coax the immature eggs inside to mature so they could be used for in vitro fertilization years later when the girls are grown. If that eventually works, Tilly says stem cells might offer a better egg supply.

Further down the road, he wonders if it also might be possible to recharge an aging woman's ovaries.

The new research was funded largely by the U.S. National Institutes of Health. Tilly co-founded a company, OvaScience Inc., to try to develop the findings into fertility treatments.

See original here:
Egg-producing stem cells found in women's ovaries

M I Walker / Getty Images

Are women born with all the eggs they'll ever have? Harvard scientists say possibly not. Their discovery of stem cells in human ovaries could someday help infertile women produce new eggs.

For 60 years, doctors have believed women were born with all the eggs they’ll ever have. Now Harvard scientists are challenging that dogma, saying they’ve discovered the ovaries of young women harbor very rare stem cells capable of producing new eggs.

If Sunday’s report is confirmed, harnessing those stem cells might one day lead to better treatments for women left infertile because of disease — or simply because they’re getting older.

“Our current views of ovarian aging are incomplete. There’s much more to the story than simply the trickling away of a fixed pool of eggs,” said lead researcher Jonathan Tilly of Harvard’s Massachusetts General Hospital, who has long hunted these cells in a series of controversial studies.

Tilly’s previous work drew fierce skepticism, and independent experts urged caution about the latest findings.

A key next step is to see whether other laboratories can verify the work. If so, then it would take years of additional research to learn how to use the cells, said Teresa Woodruff, fertility preservation chief at Northwestern University’s Feinberg School of Medicine.

Still, even a leading critic said such research may help dispel some of the enduring mystery surrounding how human eggs are born and mature.

“This is going to spark renewed interest, and more than anything else it’s giving us some new directions to work in,” said David Albertini, director of the University of Kansas’ Center for Reproductive Sciences. While he has plenty of questions about the latest work, “I’m less skeptical,” he said.

Scientists have long taught that all female mammals are born with a finite supply of egg cells, called ooctyes, that runs out in middle age. Tilly, Mass General’s reproductive biology director, first challenged that notion in 2004, reporting that the ovaries of adult mice harbor some egg-producing stem cells. Recently, Tilly noted, a lab in China and another in the U.S. also have reported finding those rare cells in mice.

But do they exist in women? Enter the new work, reported Sunday in the journal Nature Medicine.

First Tilly had to find healthy human ovaries to study. He collaborated with scientists at Japan’s Saitama Medical University, who were freezing ovaries donated for research by healthy 20-somethings who underwent a sex-change operation.

Tilly also had to address a criticism: How to tell if he was finding true stem cells or just very immature eggs. His team latched onto a protein believed to sit on the surface of only those purported stem cells and fished them out. To track what happened next, the researchers inserted a gene that makes some jellyfish glow green into those cells. If the cells made eggs, those would glow, too.

“Bang, it worked — cells popped right out” of the human tissue, Tilly said.

Researchers watched through a microscope as new eggs grew in a lab dish. Then came the pivotal experiment: They injected the stem cells into pieces of human ovary. They transplanted the human tissue under the skin of mice, to provide it a nourishing blood supply. Within two weeks, they reported telltale green-tinged egg cells forming.

That’s still a long way from showing they’ll mature into usable, quality eggs, Albertini said.

And more work is needed to tell exactly what these cells are, cautioned reproductive biologist Kyle Orwig of the University of Pittsburgh Medical Center, who has watched Tilly’s work with great interest.

But if they’re really competent stem cells, Orwig asked, then why would women undergo menopause? Indeed, something so rare wouldn’t contribute much to a woman’s natural reproductive capacity, added Northwestern’s Woodruff.

Tilly argues that using stem cells to grow eggs in lab dishes might one day help preserve cancer patients’ fertility. Today, Woodruff’s lab and others freeze pieces of girls’ ovaries before they undergo fertility-destroying chemotherapy or radiation. They’re studying how to coax the immature eggs inside to mature so they could be used for in vitro fertilization years later when the girls are grown. If that eventually works, Tilly says stem cells might offer a better egg supply.

Further down the road, he wonders if it also might be possible to recharge an aging woman’s ovaries.

The new research was funded largely by the National Institutes of Health. Tilly co-founded a company, OvaScience Inc., to try to develop the findings into fertility treatments.

Go here to read the rest:
Rethinking Infertility: Study Shows Women Have Egg-Producing Stem Cells

For 60 years, doctors have thought women were born with all the eggs they’ll ever have. Now Harvard scientists are challenging that belief, saying they’ve discovered the ovaries of young women harbor very rare stem cells capable of producing new eggs.

If Sunday’s report is confirmed, harnessing those stem cells might one day lead to better treatments for women left infertile because of disease - or simply because they’re getting older.

“Our current views of ovarian aging are incomplete. There’s much more to the story than simply the trickling away of a fixed pool of eggs,” said lead researcher Jonathan Tilly of Harvard’s Massachusetts General Hospital, who has long hunted these cells in a series of controversial studies.

Mr. Tilly’s previous work drew fierce skepticism, and independent experts urged caution about the latest findings.

A key next step is to see whether other laboratories can verify the work. If so, then it would take years of additional research to learn how to use the cells, said Teresa Woodruff, fertility preservation chief at Northwestern University’s Feinberg School of Medicine.

Still, even a leading critic said such research may help dispel some of the enduring mystery surrounding how human eggs are born and mature.

“This is going to spark renewed interest, and more than anything else it’s giving us some new directions to work in,” said David Albertini, director of the University of Kansas' Center for Reproductive Sciences. While he has plenty of questions about the latest work, “I’m less skeptical,” he said.

Scientists have long taught that all female mammals are born with a finite supply of egg cells, called ooctyes, that runs out in middle age. Mr. Tilly, Mass General’s reproductive biology director, first challenged that notion in 2004, reporting that the ovaries of adult mice harbor some egg-producing stem cells. Recently, Mr. Tilly noted, a lab in China and another in the U.S. also have reported finding those rare cells in mice.

But do they exist in women? Enter the new work, reported Sunday in the journal Nature Medicine.

Mr. Tilly collaborated with scientists at Japan’s Saitama Medical University who were freezing ovaries donated for research by healthy 20-somethings who underwent a sex-change operation.

Mr. Tilly also had to address a criticism: how to tell if he was finding true stem cells or just very immature eggs. His team latched onto a protein believed to sit on the surface of only those purported stem cells and fished them out. To track what happened next, the researchers inserted a gene that makes some jellyfish glow green into those cells. If the cells made eggs, those would glow, too.

“Bang, it worked - cells popped right out” of the human tissue, Mr. Tilly said.

Researchers watched through a microscope as new eggs grew in a lab dish. Then came the pivotal experiment: They injected the stem cells into pieces of human ovary and transplanted the human tissue under the skin of mice. Within two weeks, they reported telltale green-tinged egg cells forming.

More work also is needed to tell exactly what these cells are and whether they’ll mature in usable eggs, cautioned reproductive biologist Kyle Orwig of the University of Pittsburgh Medical Center, who has watched Mr. Tilly’s work with great interest.

But if they’re really competent stem cells, Mr. Orwig asked, then why would women undergo menopause? Indeed, something so rare wouldn’t contribute much to a woman’s natural reproductive capacity, added Northwestern’s Ms. Woodruff.

Copyright 2012 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

Read the original post:
Report says women have egg-producing stem cells

1:00 AM
If confirmed, harnessing such cells may lead to better treatments for women left infertile by disease or age.

The Associated Press

WASHINGTON - For 60 years, doctors have believed that women were born with all the eggs they'll ever have. Now Harvard scientists say they've found that the ovaries of young women harbor rare stem cells capable of producing new eggs.

FOR MORE

READ A SUMMARY of the report on how women's stem cells can be turned into eggs: tinyurl.com/6w6kass

If Sunday's report is confirmed, harnessing those stem cells might one day lead to better treatments for women left infertile because of disease -- or simply because they're getting older.

"Our current views of ovarian aging are incomplete. There's much more to the story than simply the trickling away of a fixed pool of eggs," said lead researcher Jonathan Tilly of Harvard's Massachusetts General Hospital, who has long hunted these cells in a series of controversial studies.

A next step is to see whether other laboratories can verify the work. If so, then it would take years of further study to learn how to use the cells, said Teresa Woodruff, fertility preservation chief at Northwestern University's Feinberg School of Medicine.

Still, even a leading critic said such research may help dispel some of the enduring mystery surrounding how human eggs are born and mature.

"More than anything else, it's giving us some new directions to work in," said David Albertini, director of the University of Kansas' Center for Reproductive Sciences.

Scientists have long taught that all female mammals are born with a finite supply of egg cells, called ooctyes, that runs out in middle age. Tilly first challenged that notion in 2004, reporting that the ovaries of adult mice harbor some egg-producing stem cells.

But do they exist in women? Enter the new work, reported Sunday in the journal Nature Medicine.

Tilly collaborated with scientists at Japan's Saitama Medical University, who were freezing ovaries donated for study by healthy 20-somethings who underwent sex-change operations.

He had to figure out how to tell if he was finding true stem cells or just very immature eggs.

His team latched on to a protein believed to sit on the surface of only those purported stem cells and fished them out. To track what happened next, the researchers inserted a gene that makes some jellyfish glow green into those cells. If the cells made eggs, those would glow, too.

"Bang, it worked -- cells popped right out" of the human tissue, Tilly said.

Researchers watched through a microscope as new eggs grew in a lab dish. Then came the pivotal experiment: They injected the stem cells into pieces of human ovary. They transplanted the human tissue under the skin of mice, to provide it a nourishing blood supply. Within two weeks, they reported telltale green-tinged egg cells forming.

Link:
Rare stem cells may produce new eggs, scientists say

February 27, 2012, 12:41 AM EST

By Ryan Flinn

Feb. 27 (Bloomberg) -- Stem cells taken from human ovaries were used to produce early-stage eggs by scientists in Boston who may have created a new method to help infertile women.

Females have a fixed number of eggs from birth that are depleted by the time of menopause. The finding, published today in the journal Nature Medicine, challenges the belief that their ovaries can’t make more. The research was led by Jonathan Tilly, the director of Massachusetts General Hospital’s Vincent Center for Reproductive Biology.

Tilly reported in 2004 that ovarian stem cells in mice create new eggs, or oocytes, in a way similar to how stem cells in male testes produce sperm throughout a man’s life. His latest work, if reproduced, would suggest the same is true for human ovaries, potentially pointing at new ways to aid fertility by delaying when the ovaries stop functioning.

“The 50-year-old belief in our field wasn’t actually based on data proving it was impossible, or not ongoing,” Tilly said in a telephone interview. “It was simply an assumption made because there was no evidence indicating otherwise. We have human cells that can produce new oocytes.”

In the study, healthy ovaries were obtained from consenting patients undergoing sex reassignment surgery. The researchers were able to identify ovarian stem cells because they express a rare protein that’s only seen in reproductive cells.

The stem cells from the ovaries were injected into human ovarian tissue that was then grafted under the skin of mice, which provided the blood supply that enabled growth. Within two weeks, early stage human follicles with oocytes had formed.

7-Million Eggs

A female is most endowed with oocytes, or eggs, as a fetus, when she has about 7 million. That number that drops to 1 million by birth, and around 300,000 by puberty. By menopause, the number is zero. Since the 1950’s, scientists thought that ovarian stem cells capable of producing new eggs are only active during fetal development.

“This paper essentially opens the door to the ability to control oocyte development in human ovaries,” Tilly said.

About 10 percent of women of child-bearing age in the U.S., or 6.1 million, have difficulty getting pregnant or staying pregnant, according to the Centers for Disease Control and Prevention. Most cases of female infertility are caused by problems with ovulation, hormone imbalance or age.

The study by Tilley and his colleagues offers “a new model system for understanding the human egg cell,” said David F. Albertini, director of the Center for Reproductive Services and professor in the department of molecular and integrative physiology at Kansas University, in a telephone interview.

‘Practical Applications”

Still, “there’s a long way to go before this has real practical applications. I’ve spent 35 years of my life studying egg cells and this is a cell that is at least as complicated as a neuron in the brain, if not more,” Albertini said.

The work needs to be reproduced and expanded by other scientists “to make it into something that will make us confident the cells are safe to use and we could actually use them to repopulate an egg-depleted ovary,” he said.

Tilly’s team is exploring the development of an ovarian stem-cell bank that can be cryogenically frozen and thawed without damage, unlike human eggs, he said. The researchers are also working to identify hormones and other growth factors for accelerating production of eggs from human ovarian stem cells and ways to improve in-vitro fertilization.

“The problem we face with IVF is we don’t have many eggs to work with,” he said. “These cells are renewable. If we are successful -- and it’s a big if -- in generating functioning eggs from these cells, we can generate as many eggs as we need to on a per patient basis.”

Tilly is also collaborating with researchers at the University of Edinburgh in the U.K. to determine whether the oocytes can be developed into fully mature human eggs for fertilizing. The U.S bans creating or fertilizing embryos for experimental purposes, he said.

A company Tilly co-founded, Boston-based OvaScience Inc., has licensed the technology for potential commercial applications.

--With assistance from Sarah Frier in New York. Editors: Angela Zimm, Andrew Pollack

To contact the reporter on this story: Ryan Flinn in San Francisco at rflinn@bloomberg.net

To contact the editor responsible for this story: Reg Gale at rgale5@bloomberg.net

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Ovarian Stem Cells Make Human Eggs in Possible Aid to Fertility

20-02-2012 04:06 (Watch in 720p if possible) Here we can see the underside of mouse tail skin. Under the Microscope is a collection of videos that show glimpses of the natural and man-made world in stunning close-up. They are released every Monday and Thursday and you can see them here: bit.ly Claire Cox: "The epidermis, which is the outer layer of mammalian skin, is maintained by numerous stem cell populations. The identification of the factors involved in controlling these populations and thus epidermal maintenance is highly valuable. Not only will it provide information as to how a complex tissue is organised and controlled, the principles that are learnt can be applied to other tissues. Through the work that I am completing, I hope that I can also gain a perspective as to what goes wrong in disease processes such as skin cancer. Skin cancer is one of the most prevalent cancers in the world, and understanding what goes wrong and the factors involved could potentially lead to new ideas as to prevention and treatment." The image is 700µm in width - this is about the size of the full stop in this sentence. About 5000 cells would fit on the surface of a full stop. Many thanks to: Dr Michaela Frye, Frye Lab members, Peter Humphreys, Margaret McLeish. More info: Wellcome Trust Centre For Stem Cell Research http://www.cscr.cam.ac.uk Department of Physiology Development and Neuroscience http Claire Cox's profile: http://www.cscr.cam.ac.uk Graduate School of Life Sciences and its annual Poster and Image ...

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Under the Microscope #10 - Video

For 60 years, doctors have thought women were born with all the eggs they’ll ever have. Now Harvard scientists are challenging that belief, saying they’ve discovered the ovaries of young women harbor very rare stem cells capable of producing new eggs.

If Sunday’s report is confirmed, harnessing those stem cells might one day lead to better treatments for women left infertile because of disease - or simply because they’re getting older.

“Our current views of ovarian aging are incomplete. There’s much more to the story than simply the trickling away of a fixed pool of eggs,” said lead researcher Jonathan Tilly of Harvard’s Massachusetts General Hospital, who has long hunted these cells in a series of controversial studies.

Mr. Tilly’s previous work drew fierce skepticism, and independent experts urged caution about the latest findings.

A key next step is to see whether other laboratories can verify the work. If so, then it would take years of additional research to learn how to use the cells, said Teresa Woodruff, fertility preservation chief at Northwestern University’s Feinberg School of Medicine.

Still, even a leading critic said such research may help dispel some of the enduring mystery surrounding how human eggs are born and mature.

“This is going to spark renewed interest, and more than anything else it’s giving us some new directions to work in,” said David Albertini, director of the University of Kansas' Center for Reproductive Sciences. While he has plenty of questions about the latest work, “I’m less skeptical,” he said.

Scientists have long taught that all female mammals are born with a finite supply of egg cells, called ooctyes, that runs out in middle age. Mr. Tilly, Mass General’s reproductive biology director, first challenged that notion in 2004, reporting that the ovaries of adult mice harbor some egg-producing stem cells. Recently, Mr. Tilly noted, a lab in China and another in the U.S. also have reported finding those rare cells in mice.

But do they exist in women? Enter the new work, reported Sunday in the journal Nature Medicine.

Mr. Tilly collaborated with scientists at Japan’s Saitama Medical University who were freezing ovaries donated for research by healthy 20-somethings who underwent a sex-change operation.

Mr. Tilly also had to address a criticism: how to tell if he was finding true stem cells or just very immature eggs. His team latched onto a protein believed to sit on the surface of only those purported stem cells and fished them out. To track what happened next, the researchers inserted a gene that makes some jellyfish glow green into those cells. If the cells made eggs, those would glow, too.

“Bang, it worked - cells popped right out” of the human tissue, Mr. Tilly said.

Researchers watched through a microscope as new eggs grew in a lab dish. Then came the pivotal experiment: They injected the stem cells into pieces of human ovary and transplanted the human tissue under the skin of mice. Within two weeks, they reported telltale green-tinged egg cells forming.

More work also is needed to tell exactly what these cells are and whether they’ll mature in usable eggs, cautioned reproductive biologist Kyle Orwig of the University of Pittsburgh Medical Center, who has watched Mr. Tilly’s work with great interest.

But if they’re really competent stem cells, Mr. Orwig asked, then why would women undergo menopause? Indeed, something so rare wouldn’t contribute much to a woman’s natural reproductive capacity, added Northwestern’s Ms. Woodruff.

Copyright 2012 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

Read the original:
Report says women have egg-producing stem cells

By The Associated Press

WASHINGTON — For 60 years, doctors have believed women were born with all the eggs they’ll ever have. Now Harvard scientists are challenging that dogma, saying they’ve discovered the ovaries of young women harbor very rare stem cells capable of producing new eggs.

If Sunday’s report is confirmed, harnessing those stem cells might one day lead to better treatments for women left infertile because of disease — or simply because they’re getting older.

“Our current views of ovarian aging are incomplete. There’s much more to the story than simply the trickling away of a fixed pool of eggs,” said lead researcher Jonathan Tilly of Harvard’s Massachusetts General Hospital, who has long hunted these cells in a series of controversial studies.

Tilly’s previous work drew fierce skepticism, and independent experts urged caution about the latest findings.

A key next step is to see whether other laboratories can verify the work. If so, then it would take years of additional research to learn how to use the cells, said Teresa Woodruff, fertility preservation chief at Northwestern University’s Feinberg School of Medicine.

Still, even a leading critic said such research may help dispel some of the enduring mystery surrounding how human eggs are born and mature.

“This is going to spark renewed interest, and more than anything else it’s giving us some new directions to work in,” said David Albertini, director of the University of Kansas’ Center for Reproductive Sciences. While he has plenty of questions about the latest work, “I’m less skeptical,” he said.

Scientists have long taught that all female mammals are born with a finite supply of egg cells, called ooctyes, that runs out in middle age. Tilly, Mass General’s reproductive biology director, first challenged that notion in 2004, reporting that the ovaries of adult mice harbor some egg-producing stem cells. Recently, Tilly noted, a lab in China and another in the U.S. also have reported finding those rare cells in mice.

But do they exist in women? Enter the new work, reported Sunday in the journal Nature Medicine.

First, Tilly had to find healthy human ovaries to study. He collaborated with scientists at Japan’s Saitama Medical University, who were freezing ovaries donated for research by healthy 20-somethings who underwent a sex-change operation. Continued...

Tilly also had to address a criticism: How to tell if he was finding true stem cells or just very immature eggs. His team latched onto a protein believed to sit on the surface of only those purported stem cells and fished them out. To track what happened next, the researchers inserted a gene that makes some jellyfish glow green into those cells. If the cells made eggs, those would glow, too.

“Bang, it worked — cells popped right out” of the human tissue, Tilly said.

Researchers watched through a microscope as new eggs grew in a lab dish. Then came the pivotal experiment: They injected the stem cells into pieces of human ovary. They transplanted the human tissue under the skin of mice, to provide it a nourishing blood supply. Within two weeks, they reported telltale green-tinged egg cells forming.

That’s still a long way from showing they’ll mature into usable, quality eggs, Albertini said.

And more work is needed to tell exactly what these cells are, cautioned reproductive biologist Kyle Orwig of the University of Pittsburgh Medical Center, who has watched Tilly’s work with great interest.

But if they’re really competent stem cells, Orwig asked, then why would women undergo menopause? Indeed, something so rare wouldn’t contribute much to a woman’s natural reproductive capacity, added Northwestern’s Woodruff.

Tilly argues that using stem cells to grow eggs in lab dishes might one day help preserve cancer patients’ fertility. Today, Woodruff’s lab and others freeze pieces of girls’ ovaries before they undergo fertility-destroying chemotherapy or radiation. They’re studying how to coax the immature eggs inside to mature so they could be used for in vitro fertilization years later when the girls are grown. If that eventually works, Tilly says stem cells might offer a better egg supply.

Further down the road, he wonders if it also might be possible to recharge an aging woman’s ovaries.

The new research was funded largely by the National Institutes of Health. Tilly co-founded a company, OvaScience Inc., to try to develop the findings into fertility treatments.

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Report: Stem cells may create new eggs

Researchers have found that it is possible for stem cells in adult women to produce human eggs in the laboratory, according to the BBC.

The study, published in the journal Nature Medicine, said further experiments on mice showed that eggs derived in such a manner can be fertilized, potentially opening the door for creating an unlimited supply of eggs in order to treat infertility.

Bloomberg reported that the research was conducted by a team led by Jonathan Tilly, the director of Massachusetts General Hospital’s Vincent Center for Reproductive Biology, which is affiliated with Harvard University.

The research builds on a discovery in 2004, in which Tilly found that ovarian stem cells in mice could create new eggs, said Bloomberg. The study’s findings challenge the belief that a woman’s ovaries can’t make any more eggs after menopause.

More on GlobalPost: Stem cells used to heal heart attack damage

The New York Times said the research used a cell-sorting machine to target a special protein that marks the surface of reproductive cells. Using those cells, the team was able to generate eggs that could potentially be fertilized and then produce embryos.

Dr. Tilly said, "The discovery of oocyte precursor cells in adult human ovaries, coupled with the fact that these cells share the same characteristic features of their mouse counterparts that produce fully functional eggs, opens the door for development of unprecedented technologies to overcome infertility in women and perhaps even delay the timing of ovarian failure."

More on GlobalPost: Scientists create brain cells from human skin in possible breakthrough for autism, Alzheimer's research

Below is the video from Nature Medicine explaining more about the procedure:

http://www.globalpost.com/dispatch/news/health/120226/researchers-used-stem-cells-produce-human-eggs

Read the rest here:
Researchers used stem cells to produce human eggs

WASHINGTON -- For 60 years, doctors have believed women were born with all the eggs they'll ever have. Now Harvard scientists are challenging that dogma, saying they've discovered the ovaries of young women harbor very rare stem cells capable of producing new eggs.

If Sunday's report is confirmed, harnessing those stem cells might one day lead to better treatments for women left infertile because of disease -- or simply because they're getting older.

"Our current views of ovarian aging are incomplete. There's much more to the story than simply the trickling away of a fixed pool of eggs," said lead researcher Jonathan Tilly of Harvard's Massachusetts General Hospital, who has long hunted these cells in a series of controversial studies.

Tilly's previous work drew fierce skepticism, and independent experts urged caution about the latest findings.

A key next step is to see whether other laboratories can verify the work. If so, then it would take years of additional research to learn how to use the cells, said Teresa Woodruff, fertility preservation chief at Northwestern University's Feinberg School of Medicine.

Still, even a leading critic said such research may help dispel some of the enduring mystery surrounding how human eggs are born and mature.

"This is going to spark renewed interest, and more than anything else it's giving us some new directions to work in," said David Albertini, director of the University of Kansas' Center for Reproductive Sciences. While he has plenty of questions about the latest work, "I'm less skeptical," he said.

Scientists have long taught that all female mammals are born with a finite supply of egg cells, called ooctyes, that runs out in middle age. Tilly, Mass General's reproductive biology director, first challenged that notion in 2004, reporting that the ovaries of adult mice harbor some egg-producing stem cells. Recently, Tilly noted, a lab in China and another in the U.S. also have reported finding those rare cells in mice.

But do they exist in women? Enter the new work, reported Sunday in the journal Nature Medicine.

First Tilly had to find healthy human ovaries to study. He collaborated with scientists at Japan's Saitama Medical University, who were freezing ovaries donated for research by healthy 20-somethings who underwent a sex-change operation.

Tilly also had to address a criticism: How to tell if he was finding true stem cells or just very immature eggs. His team latched onto a protein believed to sit on the surface of only those purported stem cells and fished them out. To track what happened next, the researchers inserted a gene that makes some jellyfish glow green into those cells. If the cells made eggs, those would glow, too.

"Bang, it worked -- cells popped right out" of the human tissue, Tilly said.

Researchers watched through a microscope as new eggs grew in a lab dish. Then came the pivotal experiment: They injected the stem cells into pieces of human ovary. They transplanted the human tissue under the skin of mice, to provide it a nourishing blood supply. Within two weeks, they reported telltale green-tinged egg cells forming.

That's still a long way from showing they'll mature into usable, quality eggs, Albertini said.

And more work is needed to tell exactly what these cells are, cautioned reproductive biologist Kyle Orwig of the University of Pittsburgh Medical Center, who has watched Tilly's work with great interest.

But if they're really competent stem cells, Orwig asked, then why would women undergo menopause? Indeed, something so rare wouldn't contribute much to a woman's natural reproductive capacity, added Northwestern's Woodruff.

Tilly argues that using stem cells to grow eggs in lab dishes might one day help preserve cancer patients' fertility. Today, Woodruff's lab and others freeze pieces of girls' ovaries before they undergo fertility-destroying chemotherapy or radiation. They're studying how to coax the immature eggs inside to mature so they could be used for in vitro fertilization years later when the girls are grown. If that eventually works, Tilly says stem cells might offer a better egg supply.

Further down the road, he wonders if it also might be possible to recharge an aging woman's ovaries.

The new research was funded largely by the National Institutes of Health. Tilly co-founded a company, OvaScience Inc., to try to develop the findings into fertility treatments.

Read the rest here:
Ovary stem cells can produce new eggs, researchers say

WASHINGTON - For 60 years, doctors have believed women were born with all the eggs they'll ever have. Now Harvard scientists are challenging that dogma, saying they've discovered the ovaries of young women harbour very rare stem cells capable of producing new eggs.

If Sunday's report is confirmed, harnessing those stem cells might one day lead to better treatments for women left infertile because of disease — or simply because they're getting older.

"Our current views of ovarian aging are incomplete. There's much more to the story than simply the trickling away of a fixed pool of eggs," said lead researcher Jonathan Tilly of Harvard's Massachusetts General Hospital, who has long hunted these cells in a series of controversial studies.

Tilly's previous work drew fierce skepticism, and independent experts urged caution about the latest findings.

A key next step is to see whether other laboratories can verify the work. If so, then it would take years of additional research to learn how to use the cells, said Teresa Woodruff, fertility preservation chief at Northwestern University's Feinberg School of Medicine.

Still, even a leading critic said such research may help dispel some of the enduring mystery surrounding how human eggs are born and mature.

"This is going to spark renewed interest, and more than anything else it's giving us some new directions to work in," said David Albertini, director of the University of Kansas' Center for Reproductive Sciences. While he has plenty of questions about the latest work, "I'm less skeptical," he said.

Scientists have long taught that all female mammals are born with a finite supply of egg cells, called ooctyes, that runs out in middle age. Tilly, Mass General's reproductive biology director, first challenged that notion in 2004, reporting that the ovaries of adult mice harbour some egg-producing stem cells. Recently, Tilly noted, a lab in China and another in the U.S. also have reported finding those rare cells in mice.

But do they exist in women? Enter the new work, reported Sunday in the journal Nature Medicine.

First Tilly had to find healthy human ovaries to study. He collaborated with scientists at Japan's Saitama Medical University, who were freezing ovaries donated for research by healthy 20-somethings who underwent a sex-change operation.

Tilly also had to address a criticism: How to tell if he was finding true stem cells or just very immature eggs. His team latched onto a protein believed to sit on the surface of only those purported stem cells and fished them out. To track what happened next, the researchers inserted a gene that makes some jellyfish glow green into those cells. If the cells made eggs, those would glow, too.

"Bang, it worked — cells popped right out" of the human tissue, Tilly said.

Researchers watched through a microscope as new eggs grew in a lab dish. Then came the pivotal experiment: They injected the stem cells into pieces of human ovary. They transplanted the human tissue under the skin of mice, to provide it a nourishing blood supply. Within two weeks, they reported telltale green-tinged egg cells forming.

That's still a long way from showing they'll mature into usable, quality eggs, Albertini said.

And more work is needed to tell exactly what these cells are, cautioned reproductive biologist Kyle Orwig of the University of Pittsburgh Medical Center, who has watched Tilly's work with great interest.

But if they're really competent stem cells, Orwig asked, then why would women undergo menopause? Indeed, something so rare wouldn't contribute much to a woman's natural reproductive capacity, added Northwestern's Woodruff.

Tilly argues that using stem cells to grow eggs in lab dishes might one day help preserve cancer patients' fertility. Today, Woodruff's lab and others freeze pieces of girls' ovaries before they undergo fertility-destroying chemotherapy or radiation. They're studying how to coax the immature eggs inside to mature so they could be used for in vitro fertilization years later when the girls are grown. If that eventually works, Tilly says stem cells might offer a better egg supply.

Further down the road, he wonders if it also might be possible to recharge an aging woman's ovaries.

The new research was funded largely by the National Institutes of Health. Tilly co-founded a company, OvaScience Inc., to try to develop the findings into fertility treatments.

Go here to see the original:
Study says women's ovaries harbour rare egg-producing stem cells, a step in fertility research

WASHINGTON — For 60 years, doctors have believed women were born with all the eggs they'll ever have. Now Harvard scientists are challenging that dogma, saying they've discovered the ovaries of young women harbor very rare stem cells capable of producing new eggs.

If Sunday's report is confirmed, harnessing those stem cells might one day lead to better treatments for women left infertile because of disease — or simply because they're getting older.

"Our current views of ovarian aging are incomplete. There's much more to the story than simply the trickling away of a fixed pool of eggs," said lead researcher Jonathan Tilly of Harvard's Massachusetts General Hospital, who has long hunted these cells in a series of controversial studies.

Tilly's previous work drew fierce skepticism, and independent experts urged caution about the latest findings.

A key next step is to see whether other laboratories can verify the work. If so, then it would take years of additional research to learn how to use the cells, said Teresa Woodruff, fertility preservation chief at Northwestern University's Feinberg School of Medicine.

Still, even a leading critic said such research may help dispel some of the enduring mystery surrounding how human eggs are born and mature.

"This is going to spark renewed interest, and more than anything else it's giving us some new directions to work in," said David Albertini, director of the University of Kansas' Center for Reproductive Sciences. While he has plenty of questions about the latest work, "I'm less skeptical," he said.

Scientists have long taught that all female mammals are born with a finite supply of egg cells, called ooctyes, that runs out in middle age. Tilly, Mass General's reproductive biology director, first challenged that notion in 2004, reporting that the ovaries of adult mice harbor some egg-producing stem cells. Recently, Tilly noted, a lab in China and another in the U.S. also have reported finding those rare cells in mice.

But do they exist in women? Enter the new work, reported in the journal Nature Medicine.

First Tilly had to find healthy human ovaries to study. He collaborated with scientists at Japan's Saitama Medical University, who were freezing ovaries donated for research by healthy 20-somethings who underwent a sex-change operation.

Tilly also had to address a criticism: How to tell if he was finding true stem cells or just very immature eggs. His team latched onto a protein believed to sit on the surface of only those purported stem cells and fished them out. To track what happened next, the researchers inserted a gene that makes some jellyfish glow green into those cells. If the cells made eggs, those would glow, too.

"Bang, it worked — cells popped right out" of the human tissue, Tilly said.

Researchers watched through a microscope as new eggs grew in a lab dish. Then came the pivotal experiment: They injected the stem cells into pieces of human ovary. They transplanted the human tissue under the skin of mice, to provide it a nourishing blood supply. Within two weeks, they reported telltale green-tinged egg cells forming.

That's still a long way from showing they'll mature into usable, quality eggs, Albertini said.

And more work is needed to tell exactly what these cells are, cautioned reproductive biologist Kyle Orwig of the University of Pittsburgh Medical Center, who has watched Tilly's work with great interest.

But if they're really competent stem cells, Orwig asked, then why would women undergo menopause? Indeed, something so rare wouldn't contribute much to a woman's natural reproductive capacity, added Northwestern's Woodruff.

Tilly argues that using stem cells to grow eggs in lab dishes might one day help preserve cancer patients' fertility. Today, Woodruff's lab and others freeze pieces of girls' ovaries before they undergo fertility-destroying chemotherapy or radiation. They're studying how to coax the immature eggs inside to mature so they could be used for in vitro fertilization years later when the girls are grown. If that eventually works, Tilly says stem cells might offer a better egg supply.

Further down the road, he wonders if it also might be possible to recharge an aging woman's ovaries.

The new research was funded largely by the National Institutes of Health. Tilly co-founded a company, OvaScience Inc., to try to develop the findings into fertility treatments.

Copyright 2012 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

See the original post here:
Women have rare egg-producing stem cells

Public release date: 26-Feb-2012
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Contact: Sue McGreevey
smcgreevey@partners.org
617-724-2764
Massachusetts General Hospital

For the first time, Massachusetts General Hospital (MGH) researchers have isolated egg-producing stem cells from the ovaries of reproductive age women and shown these cells can produce what appear to be normal egg cells or oocytes. In the March issue of Nature Medicine, the team from the Vincent Center for Reproductive Biology at MGH reports the latest follow-up study to their now-landmark 2004 Nature paper that first suggested female mammals continue producing egg cells into adulthood.

"The primary objective of the current study was to prove that oocyte-producing stem cells do in fact exist in the ovaries of women during reproductive life, which we feel this study demonstrates very clearly," says Jonathan Tilly, PhD, director of the Vincent Center for Reproductive Biology in the MGH Vincent Department of Obstetrics and Gynecology, who led the study. "The discovery of oocyte precursor cells in adult human ovaries, coupled with the fact that these cells share the same characteristic features of their mouse counterparts that produce fully functional eggs, opens the door for development of unprecedented technologies to overcome infertility in women and perhaps even delay the timing of ovarian failure."

The 2004 report from Tilly's team challenged the fundamental belief, held since the 1950s, that female mammals are born with a finite supply of eggs that is depleted throughout life and exhausted at menopause. That paper and a 2005 follow-up published in Cell showing that bone marrow or blood cell transplants could restore oocyte production in adult female mice after fertility-destroying chemotherapy were controversial; but in the intervening years, several studies from the MGH-Vincent group and other researchers around the world have supported Tilly's work and conclusions.

These supporting studies include a 2007 Journal of Clinical Oncology report from the MGH-Vincent team that showed female mice receiving bone marrow transplants after oocyte-destroying chemotherapy were able to have successful pregnancies, delivering pups that were their genetic offspring and not of the marrow donors. A 2009 study from a team at Shanghai Jiao Tong University in China, published in Nature Cell Biology, not only isolated and cultured oocyte-producing stem cells (OSCs) from adult mice but also showed that those OSCs, after transplantation into the ovaries of chemotherapy-treated female mice, gave rise to mature oocytes that were ovulated, fertilized and developed into healthy offspring.

"That study singlehandedly deflated many of the arguments from critics of our earlier Nature paper by showing that oocyte-producing stem cells exist in mice and could develop into fully functional eggs," says Tilly. Another paper from a west-coast biotechnology company, published in Differentiation in 2010, provided further independent confirmation of Tilly's earlier conclusions regarding the presence of oocyte-producing stem cells in ovaries of adult mice.

Tilly is quick to point out, however, "These follow-up studies, while providing definitive evidence that oocyte-producing stem cells exist in ovaries of adult female mammals, were not without their limitations, leaving the question open in some scientific circles of whether the adult oocyte pool can be renewed. For example, the protocol used to isolate OSCs in the 2009 Nature Cell Biology study is a relatively crude approach that often results in the contamination of desired cells by other cell types." To address this, the MGH-Vincent team developed and validated a much more precise cell-sorting technique to isolate OSCs without contamination from other cells.

The 2009 study from China also had isolated OSCs based on cell-surface expression of a marker protein called Ddx4 or Mvh, which previously had been found only in the cytoplasm of oocytes. This apparent contradiction with earlier studies raised concerns over the validity of the protocol. Using their state-of-the-art fluorescence-activated cell sorting techniques, the MGH-Vincent team verified that, while the marker protein Ddx4 was indeed located inside oocytes, it was expressed on the surface of a rare and distinct population of ovarian cells identified by numerous genetic markers and functional tests as OSCs.

To examine the functional capabilities of the cells isolated with their new protocol, the investigators injected green fluorescent protein (GFP)-labeled mouse OSCs into the ovaries of normal adult mice. Several months later, examination of the recipient mouse ovaries revealed follicles containing oocytes with and without the marker protein. GFP-labeled and unlabeled oocytes also were found in cell clusters flushed from the animals' oviducts after induced ovulation. The GFP-labeled mouse eggs retrieved from the oviducts were successfully fertilized in vitro and produced embryos that progressed to the hatching blastocyst stage, a sign of normal developmental potential. Additionally, although the Chinese team had transplanted OSCs into ovaries of mice previously treated with chemotherapy, the MGH-Vincent team showed that it was not necessary to damage the recipient mouse ovaries with toxic drugs before introducing OSCs.

In their last two experiments, which Tilly considers to be the most groundbreaking, the MGH-Vincent team used their new cell-sorting techniques to isolate potential OSCs from adult human ovaries. The cells obtained shared all of the genetic and growth properties of the equivalent cells isolated from adult mouse ovaries, and like mouse OSCs, were able to spontaneously form cells with characteristic features of oocytes. Not only did these oocytes formed in culture dishes have the physical appearance and gene expression patterns of oocytes seen in human ovaries ? as was the case in parallel mouse experiments ? but some of these in-vitro-formed cells had only half of the genetic material normally found in all other cells of the body. That observation indicates that these oocytes had progressed through meiosis, a cell-division process unique to the formation of mature eggs and sperm.

The researchers next injected GFP-labeled human OSCs into biopsied human ovarian tissue that was then grafted beneath the skin of immune-system-deficient mice. Examination of the human tissue grafts 7 to 14 days later revealed immature human follicles with GFP-negative oocytes, probably present in the human tissue before OSC injection and grafting, as well as numerous immature human follicles with GFP-positive oocytes that would have originated from the injected human OSCs.

"These experiments provide pivotal proof-of-concept that human OSCs reintroduced into adult human ovarian tissue performed their expected function of generating new oocytes that become enclosed by host cells to form new follicles," says Tilly, a professor of Obstetrics, Gynecology and Reproductive Biology at Harvard Medical School and chief of Research at the MGH Vincent Department of Obstetrics and Gynecology. "These outcomes are exactly what we see if we perform the same experiments using GFP-expressing mouse OSCs, and GFP-expressing mouse oocytes formed that way go on to develop into fully functional eggs.

"In this paper we provide the three key pieces of evidence requested by those who have been skeptical of our previous work," he adds. "We developed and extensively validated a cell-sorting protocol to reliably purify OSCs from adult mammalian ovaries, proving once again that these very special cells exist. We tested the function of mouse oocytes produced by these OSCs and showed that they can be fertilized to produce healthy embryos. And we identified and characterized an equivalent population of oocyte-producing stem cells isolated from adult human ovaries."

Among the many potential clinical applications for these findings that Tilly's team is currently exploring are the establishment of human OSC banks ? since these cells, unlike human oocytes, can be frozen and thawed without damage ? the identification of hormones and factors that accelerate the formation of oocytes from human OSCs, the development of mature human oocytes from OSCs for in vitro fertilization, and other approaches to improve the outcomes of IVF and other infertility treatments.

###

Tilly notes that an essential part of his group's accomplishment was collaboration with study co-author Yasushi Takai, MD, PhD, a former MGH research fellow on Tilly's team and now a faculty member at Saitama Medical University in Japan. Working with his clinical colleagues at Saitama, Takai was able to provide healthy ovarian tissue from consenting patients undergoing sex reassignment surgery, many in their 20s and early 30s. Co-lead authors of the Nature Medicine report are Yvonne White, PhD, and Dori Woods, PhD, of the Vincent Center for Reproductive Biology at MGH. Additional co-authors are Osamu Ishihara, MD, PhD, and Hiroyuki Seki, MD, PhD, of Saitama Medical University.

The study was supported by a 10-year MERIT Award to Tilly from the National Institute on Aging, a Ruth L. Kirschstein National Research Service Award from the National Institutes of Health, the Henry and Vivian Rosenberg Philanthropic Fund, the Sea Breeze Foundation, and Vincent Memorial Hospital Research Funds. Tilly is a co-founder of OvaScience, Inc. (www.ovascience.com), which has licensed the commercial potential of these and other patent-protected findings of the MGH-Vincent team for development of new fertility-enhancing procedures.

Massachusetts General Hospital (www.massgeneral.org), founded in 1811, is the original and largest teaching hospital of Harvard Medical School. The MGH conducts the largest hospital-based research program in the United States, with an annual research budget of more than $750 million and major research centers in AIDS, cardiovascular research, cancer, computational and integrative biology, cutaneous biology, human genetics, medical imaging, neurodegenerative disorders, regenerative medicine, reproductive biology, systems biology, transplantation biology and photomedicine.

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Read the original post:
Mass. General researchers isolate egg-producing stem cells from adult human ovaries

An experiment that produced human eggs from stem cells could one day be a boon for women who are desperate to have a baby, according to a study published on Sunday.

The work sweeps away the belief that a woman has only a limited stock of eggs and replaces it with the theory that the supply is continuously replenished from precursor cells in the ovary, its authors said.

"The prevailing dogma in our field for the better part of the last 50 or 60 years was that young girls at birth were given a bank account of eggs at birth that's not renewable," said Jonathan Tilly, director of the Vincent Center for Reproductive Biology at Massachusetts General Hospital, who led the research.

"As they become mature and become a woman, they use those eggs up (and) the ovaries will fail when they enter menopause."

Tilly first challenged the "bank account" doctrine eight years ago, suggesting female mammals continue producing egg-making cells into adulthood rather than from a stock acquired at birth.

His theory ran into a firestorm.

Other scientists challenged the accuracy of his experiments or dismissed their conclusions as worthless, given that they had only been conducted on lab mice.

But the new work, said Tilly, not only confirms his controversial idea, but takes it farther.

In it, his team isolated egg-producing stem cells in human ovaries and then coaxed them into developing oocytes, as eggs are called.

Building on a feat by Chinese scientists, they pinpointed the oocyte stem cells by using antibodies which latched onto a protein "handle" located on the side of these cells.

The team tagged the stem cells with a fluorescent green protein -- a common trick to help figure out what happens in lab experiments.

The cells were injected into biopsied human ovarian tissue which was then grafted beneath the skin of mice.

Within 14 days, the graft had produced a budding of oocytes. Some of the eggs glowed with the fluorescent tag, proving that they came from the stem cells. But others did not, which suggested they were already present in the tissue before the injection.

Tilly said "the hairs were standing up on my arm" when he saw time-elapse video showing the eggs maturing in a lab dish.

Further work needs to be done to test the viability of the eggs, and little is known about the hormones or other mechanisms by which oocytes emerge from the stem cells.

But the impact could be far-reaching, Tilly said.

"If we can guide the process correctly, I think it opens up a chance that sometime in the future, we might get to the point of actually having an unlimited source of human eggs," Tilly said in a video recording released to the press.

"A woman could come in, have a small biopsy taken from her ovary for us to retrieve these cells. Once we get these cells out, we can take a hundred of them and make a million of them.

"If we can get to the stage of generating functional human eggs outside the body, it would rewrite essentially human assisted reproduction."

According to a press release issued by Massachusetts General Hospital, Tilly's team are already exploring the idea of banks where oocyte stem cells can be frozen and stored, and then retrieved when a woman wants to have a baby.

Human eggs are extremely delicate and likely to suffer damage when frozen and thawed, but this risk does not apply to the egg cells that make them, it said.

Previous work has shown that around one in 10 women of reproductive age is at risk of premature ageing of the ovaries, a finding with repercussions in societies where women opt ever later to become mothers.

Read more:
Pioneering lab work aims to smash women's fertility barrier

WASHINGTON (AP) — For 60 years, doctors have believed women were born with all the eggs they'll ever have. Now Harvard scientists are challenging that dogma, saying they've discovered the ovaries of young women harbor very rare stem cells capable of producing new eggs.

If Sunday's report is confirmed, harnessing those stem cells might one day lead to better treatments for women left infertile because of disease — or simply because they're getting older.

"Our current views of ovarian aging are incomplete. There's much more to the story than simply the trickling away of a fixed pool of eggs," said lead researcher Jonathan Tilly of Harvard's Massachusetts General Hospital, who has long hunted these cells in a series of controversial studies.

Tilly's previous work drew fierce skepticism, and independent experts urged caution about the latest findings.

A key next step is to see whether other laboratories can verify the work. If so, then it would take years of additional research to learn how to use the cells, said Teresa Woodruff, fertility preservation chief at Northwestern University's Feinberg School of Medicine.

Still, even a leading critic said such research may help dispel some of the enduring mystery surrounding how human eggs are born and mature.

"This is going to spark renewed interest, and more than anything else it's giving us some new directions to work in," said David Albertini, director of the University of Kansas' Center for Reproductive Sciences. While he has plenty of questions about the latest work, "I'm less skeptical," he said.

Scientists have long taught that all female mammals are born with a finite supply of egg cells, called ooctyes, that runs out in middle age. Tilly, Mass General's reproductive biology director, first challenged that notion in 2004, reporting that the ovaries of adult mice harbor some egg-producing stem cells. Recently, Tilly noted, a lab in China and another in the U.S. also have reported finding those rare cells in mice.

But do they exist in women? Enter the new work, reported Sunday in the journal Nature Medicine.

First Tilly had to find healthy human ovaries to study. He collaborated with scientists at Japan's Saitama Medical University, who were freezing ovaries donated for research by healthy 20-somethings who underwent a sex-change operation.

Tilly also had to address a criticism: How to tell if he was finding true stem cells or just very immature eggs. His team latched onto a protein believed to sit on the surface of only those purported stem cells and fished them out. To track what happened next, the researchers inserted a gene that makes some jellyfish glow green into those cells. If the cells made eggs, those would glow, too.

"Bang, it worked — cells popped right out" of the human tissue, Tilly said.

Researchers watched through a microscope as new eggs grew in a lab dish. Then came the pivotal experiment: They injected the stem cells into pieces of human ovary. They transplanted the human tissue under the skin of mice, to provide it a nourishing blood supply. Within two weeks, they reported telltale green-tinged egg cells forming.

That's still a long way from showing they'll mature into usable, quality eggs, Albertini said.

And more work is needed to tell exactly what these cells are, cautioned reproductive biologist Kyle Orwig of the University of Pittsburgh Medical Center, who has watched Tilly's work with great interest.

But if they're really competent stem cells, Orwig asked, then why would women undergo menopause? Indeed, something so rare wouldn't contribute much to a woman's natural reproductive capacity, added Northwestern's Woodruff.

Tilly argues that using stem cells to grow eggs in lab dishes might one day help preserve cancer patients' fertility. Today, Woodruff's lab and others freeze pieces of girls' ovaries before they undergo fertility-destroying chemotherapy or radiation. They're studying how to coax the immature eggs inside to mature so they could be used for in vitro fertilization years later when the girls are grown. If that eventually works, Tilly says stem cells might offer a better egg supply.

Further down the road, he wonders if it also might be possible to recharge an aging woman's ovaries.

The new research was funded largely by the National Institutes of Health. Tilly co-founded a company, OvaScience Inc., to try to develop the findings into fertility treatments.

Read the original post:
Report: Women have rare egg-producing stem cells

In research that could have far-reaching implications for female fertility, U.S. scientists have isolated stem cells from human ovarian tissue that give rise to what appear to be normal egg cells.

The finding, published Sunday in the journal Nature Medicine, builds on earlier landmark papers by the Boston researchers, which suggest that female mammals continue producing egg cells, known as oocytes, into adulthood.

Since 2004, the scientists at Massachusetts General Hospital have produced a series of papers based on work in laboratory mice, which challenge the long-held belief that female mammals are born with a finite number of eggs that run out at a certain point in the life cycle.

The team was able to isolate stem cells from ovarian tissue taken from mice, from which they grew fully functional egg cells in the lab, which could then be fertilized and even produce healthy offspring.

"The primary objective of the current study was to prove that oocyte-producing stem cells do, in fact, exist in the ovaries of women during reproductive life, which we feel this study demonstrates very clearly," said lead author Jonathan Tilly, director of the Vincent Center for Reproductive Biology at Massachusetts General.

In their experiments, the team isolated the stem cells from ovarian tissue that had been removed from women in their 20s and early 30s.

When put in culture dishes in the lab, these stem cells gave rise to cells with the characteristic features of oocytes, including the physical appearance and gene expression patterns of those seen inside human ovaries.

"They spontaneously generate eggs in the dish," Tilly said in a phone interview, noting that they proliferate so well that a small number of stem cells could easily spawn a million egg cells in the lab.

The researchers next took stem cells they had genetically manipulated to glow green and injected them into snippets of human ovarian tissue. These prepared tissue bits were then grafted beneath the skin of specially bred mice, which have no immune system that can cause rejection of human tissue.

Within two weeks, researchers discovered the implanted ovarian tissue in the mice contained numerous immature human follicles with egg cells that originated from the injected stem cells. Follicles are small sacs within the ovary which contain maturing eggs.

Tilly said they knew the eggs cells had arisen from the injected stem cells "because they were all green."

Among the many potential clinical applications the researchers are exploring is whether these stem cells could produce oocytes that could play a role in in-vitro fertilization, as well as other applications to improve the outcomes of IVF and other infertility treatments.

"Can we use these cells for fertility reasons to maximize the opportunity for patients who are experiencing infertility to have different options available to them to have a genetically matched child?" asked Tilly.

"I think it's a fairly good possibility that at some point in the not-too-distant future there will be clinical protocols developed using some aspect of these cells or their properties that will have a significant impact on human reproduction."

Among them is the idea of extracting structures responsible for energy production in cells — called mitochondria — from the stem cells and injecting them into a woman's eggs at the time of in-vitro fertilization, with the hope of boosting the chances of conception and a successful birth.

But Tilly said another idea is to see whether these ovarian stem cells could be used to delay menopause — and the myriad health effects that can develop as women age.

"I've always been intrigued by the prospects of what if you could slow the rate at which the egg cell pool goes away and end up keeping an ovary functioning long past its normal time of failure," he said.

"With these egg stem cells, it raises the prospect that by harnessing the power of those cells, perhaps we can control the rate at which that precious reserve of egg cells is depleted and maybe even delay it ... And if you could achieve that, what would happen? Would we truly see a benefit or would there be unforeseen bad effects?"

More than a decade ago, Tilly's lab created a mouse through genetic manipulation that did not experience ovarian failure with age and was able to maintain an adequate reservoir of eggs.

"So it didn't undergo the equivalent of menopause," he said, or "mouseopause" as the scientists have dubbed it.

While normal mice as they reach old age experience health problems similar to those of postmenopausal women — including declining eyesight and hearing, hair loss, osteoporosis, diminished cognitive function and reduced muscle mass — these genetically modified mice did not. Nor did they have an increased risk of cancer.

So could these stem cells one day be used as the basis for an anti-aging treatment?

"There would be some pretty significant health benefits that would come out of it," said Tilly, if that were the case.

Even though every aspect of the human oocyte-producing stem cells have so far matched what the researchers have found in their mouse equivalents, Tilly conceded that "mouse is mouse — and perhaps human will be different."

"We don't know" if eggs generated from human ovarian stem cells will be normal and healthy, he said. "We will have to be very careful if and when we get to that stage."

Read this article:
Human ovarian stem cells may hold promise for treating infertility: study

By Ryan Flinn - Sun Feb 26 18:00:00 GMT 2012

Stem cells taken from human ovaries can produce normal, healthy eggs, scientists demonstrated for the first time in an experiment that may lead to new methods to help infertile women.

Woman have a fixed number of eggs from birth that are depleted by the time of menopause. The finding, published today in the journal Nature Medicine, challenges the belief that their ovaries can't make make more. The research was led by Jonathan Tilly, director of Massachusetts General Hospital’s Vincent Center for Reproductive Biology.

Tilly discovered in 2004 that ovarian stem cells in mice create new eggs, or oocytes, in a manner that's similar to how stem cells in male testes produce sperm throughout a man’s life. The latest study proves the same is true in human ovaries, and may point to new ways to overcome infertility or preserve fertility by delaying when a woman’s ovaries stop functioning, Tilly said in a telephone interview.

“The 50-year-old belief in our field wasn’t actually based on data proving it was impossible, or not ongoing, it was simply an assumption made because there was no evidence indicating otherwise,” Tilly said. “We have human cells that can produce new oocytes.”

A female is most endowed with oocytes as a fetus, when she has about 7 million. That number that drops to 1 million by birth, and around 300,000 by puberty. By menopause, the number is zero. Since the 1950’s, scientists thought that ovarian stem cells capable of producing new eggs are only active during fetal development.

Ovarian Stem Cells

In the study, healthy ovaries were obtained from consenting patients undergoing sex reassignment surgery. The researchers were able to identify ovarian stem cells because they express a rare protein that’s only seen in reproductive cells.

The stem cells from the ovaries were injected into human ovarian tissue that was then grafted under the skin of mice, which provided the blood supply that enabled the cells to grow. Within two weeks, early stage human follicles with oocytes had begun to form.

“This paper essentially opens the door to the ability to control oocyte development in human ovaries,” Tilly said.

About 10 percent of women of child-bearing age in the U.S., or 6.1 million, have difficulty getting pregnant or staying pregnant, according to the Centers for Disease Control and Prevention. Most cases of female infertility are caused by problems with ovulation, hormone imbalance or age.

Infertility Treatments

Infertility in women is now treated through drugs, surgery, artificial insemination or assisted reproductive technology, in which the woman’s eggs are mixed with sperm outside the body, then reinserted.

The study offers “a new model system for understanding the human egg cell,” according to David F. Albertini, director of the Center for Reproductive Services and professor in the department of molecular and integrative physiology at Kansas University. Still, “there’s a long way to go before this has real practical applications,” he said.

“I’ve spent 35 years of my life studying egg cells and this is a cell that is at least as complicated as a neuron in the brain, if not more,” Albertini said in an interview. “You will need to establish reproducibility from one lab to the next, and hopefully others will be able to confirm his work and extend it, make it into something that will make us confident that the cells are safe to use and we could actually use them to repopulate an egg-depleted ovary.”

New Therapies

The research is opening other therapeutic avenues in fertility treatment, Tilly said.

His team is exploring the development of a bank for ovarian stem cells, which can be cryogenically frozen and thawed without damage, unlike human oocytes. The researchers are also working to identify hormones and other growth factors for accelerating the production of eggs from human ovarian stem cells and ways to improve in-vitro fertilization.

“The problem we face with IVF is we don’t have many eggs to work with,” he said. “These cells are renewable. If we are successful -- and it’s a big if -- in generating functioning eggs from these cells, we can generate as many eggs as we need to on a per patient basis.”

Tilly is also collaborating with researchers at the University of Edinburgh in the U.K. to determine whether the oocytes can be developed into fully mature human eggs for fertilizing. The U.S bans creating or fertilizing embryos for experimental purposes, he said.

A company Tilly co-founded, Boston-based OvaScience Inc., has licensed the technology for potential commercial applications.

To contact the reporter on this story: Ryan Flinn in San Francisco at rflinn@bloomberg.net

To contact the editor responsible for this story: Reg Gale at rgale5@bloomberg.net

Follow this link:
Ovarian Stem Cells Produce Eggs in Method That May Aid Fertility Therapy

February 26, 2012, 6:47 PM EST

By Ryan Flinn

Feb. 26 (Bloomberg) -- Stem cells taken from human ovaries can produce normal, healthy eggs, scientists demonstrated for the first time in an experiment that may lead to new methods to help infertile women.

The finding challenges a belief that women have a fixed number of eggs, or oocytes, from birth that are depleted by the time of menopause, and that their ovaries can't make make more. The research, led by Jonathan Tilly, director of Harvard University-affiliated Massachusetts General Hospital’s Vincent Center for Reproductive Biology, is published today in the journal Nature Medicine.

In 2004, Tilly discovered that ovarian stem cells in mice can create new eggs, similar to how stem cells in male testes produce sperm throughout a man’s life. The latest study proves the same is true in human ovaries, and may point to new ways to overcome infertility or preserve fertility by delaying the time when a woman’s ovaries stop functioning, he said.

“The 50-year-old belief in our field wasn’t actually based on data proving it was impossible, or not ongoing, it was simply an assumption made because there was no evidence indicating otherwise,” Tilly said in a telephone interview. “We have human cells that can produce new oocytes.”

A female is most endowed with oocytes as a fetus, when she has about 7 million. That number that drops to 1 million by birth, and around 300,000 by puberty. By menopause, the number is zero. Since the 1950’s, scientists thought that ovarian stem cells capable of producing new eggs are only active during fetal development.

Ovarian Stem Cells

In the study, healthy ovaries were obtained from consenting patients undergoing sex reassignment surgery. The researchers were able to identify ovarian stem cells because they express a rare protein that’s only seen in reproductive cells.

The stem cells from the ovaries were injected into human ovarian tissue that was then grafted under the skin of mice, which provided the blood supply that enabled the cells to grow. Within two weeks, early stage human follicles with oocytes had begun to form.

“This paper essentially opens the door to the ability to control oocyte development in human ovaries,” Tilly said.

About 10 percent of women of child-bearing age in the U.S., or 6.1 million, have difficulty getting pregnant or staying pregnant, according to the Centers for Disease Control and Prevention. Most cases of female infertility are caused by problems with ovulation, hormone imbalance or age.

Infertility Treatments

Infertility in women is now treated through drugs, surgery, artificial insemination or assisted reproductive technology, in which the woman’s eggs are mixed with sperm outside the body, then reinserted.

The study offers “a new model system for understanding the human egg cell,” according to David F. Albertini, director of the Center for Reproductive Services and professor in the department of molecular and integrative physiology at Kansas University. Still, “there’s a long way to go before this has real practical applications,” he said.

“I’ve spent 35 years of my life studying egg cells and this is a cell that is at least as complicated as a neuron in the brain, if not more,” Albertini said in an interview. “You will need to establish reproducibility from one lab to the next, and hopefully others will be able to confirm his work and extend it, make it into something that will make us confident that the cells are safe to use and we could actually use them to repopulate an egg-depleted ovary.”

New Therapies

The research is opening other therapeutic avenues in fertility treatment, Tilly said.

His team is exploring the development of a bank for ovarian stem cells, which can be cryogenically frozen and thawed without damage, unlike human oocytes. The researchers are also working to identify hormones and other growth factors for accelerating the production of eggs from human ovarian stem cells and ways to improve in-vitro fertilization.

“The problem we face with IVF is we don’t have many eggs to work with,” he said. “These cells are renewable. If we are successful -- and it’s a big if -- in generating functioning eggs from these cells, we can generate as many eggs as we need to on a per patient basis.”

Tilly is also collaborating with researchers at the University of Edinburgh in the U.K. to determine whether the oocytes can be developed into fully mature human eggs for fertilizing. The U.S bans creating or fertilizing embryos for experimental purposes, he said.

A company Tilly co-founded, Boston-based OvaScience Inc., has licensed the technology for potential commercial applications.

--With assistance from Sarah Frier in New York. Editors: Angela Zimm, Andrew Pollack

To contact the reporter on this story: Ryan Flinn in San Francisco at rflinn@bloomberg.net

To contact the editor responsible for this story: Reg Gale at rgale5@bloomberg.net

See the original post here:
Ovarian Stem Cells Produce Eggs in Method That May Aid Fertility

Breakthrough stem cell research at Scripps Research Institute in La Jolla, Calif. has the potential to revive endangered species. Researchers at the Center for Regenerative Medicine are aiming to turn stem cells into gametes. Once new eggs and sperm are created, “test tube babies” can be born, possibly preserving a species.

In 1972, researchers preserved skin cells of certain endangered species at the Frozen Zoo, hoping that future technology would help to revive populations, and today Scripps researchers are combining the frozen skin cells with human stem cells to generate stem cells specific to the animal. Stem cells are turned into gametes through re-programming, a process in which retroviruses are used to bring the cells back to earlier stages of development. Last month, scientists created mouse sperm cells through this process.

Scientists view this method of species preservation as a last resort when cheaper, simpler means have failed. For instance, the white rhino, whose population is numbered at seven in the world, would benefit immensely since other methods of trying to save the species have failed. Scientists also hope to help the drill, a West African primate threatened by hunting and habitat degradation.

—compiled by Michelle Lim

See the original post here:
One Response to “Rescuing the white rhino?”

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Claire Cox: “The identification of the factors involved in controlling these populations and thus epidermal maintenance is highly valuable. Not only will it provide information as to how a complex tissue is organized and controlled, the principles that are learnt can be applied to other tissues. Through the work that I am completing, I hope that I can also gain a perspective as to what goes wrong in disease processes such as skin cancer. Skin cancer is one of the most prevalent cancers in the world, and understanding what goes wrong and the factors involved could potentially lead to new ideas as to prevention and treatment.”

The image is 700µm in width – this is about the size of the full stop in this sentence. About 5000 cells would fit on the surface of a full stop.

Under the Microscope is a collection of videos that show glimpses of the natural and man-made world in stunning close-up. They are released every Monday and Thursday and you can see them here: http://bit.ly/A6bwCE

Provided by University of Cambridge (news : web)

Link:
Under the Microscope #10 - Mouse tail skin