ScienceDaily (Sep. 4, 2011) — Starting with normal skin cells, scientists from The Scripps Research Institute have produced the first stem cells from endangered species. Such cells could eventually make it possible to improve reproduction and genetic diversity for some species, possibly saving them from extinction, or to bolster the health of endangered animals in captivity.A description of the accomplishment appeared in an advance online edition of the journal Nature Methods on September 4, 2011.
Genesis
About five years ago, Oliver Ryder, PhD, the director of genetics at the San Diego Zoo Institute for Conservation Research, contacted Jeanne Loring, PhD, professor of developmental neurobiology at Scripps Research, to discuss the possibility of collecting stem cells from endangered species. Ryder's team had already established the Frozen Zoo, a bank of skin cells and other materials from more than 800 species and wondered if the thousands of samples they had amassed might be used as starting points.
Just as is hoped with humans, Ryder thought stem cells from endangered species might enable lifesaving medical therapies or offer the potential to preserve or expand genetic diversity by offering new reproduction possibilities.
At the time, although researchers were working with stem cells from embryos, scientists had not yet developed techniques for reliably inducing normal adult cells to become stem cells. But the technology arrived soon after, and scientists now accomplish this feat, called induced pluripotency, by inserting genes in normal cells that spark the transformation.
While Loring's team met with Ryder in early 2008, they realized that these newly emerging techniques might be applied to endangered species. Postdoctoral fellow Inbar Friedrich Ben-Nun, PhD, set out to systematically explore the possibilities.
Ryder suggested two species for initial work. The first was a highly endangered primate called a drill that he chose because of its close genetic connection to humans, and because in captivity the animals often suffer from diabetes, which researchers are working to treat in humans using stem cell-based therapies.
The northern white rhinoceros was the second candidate. Ryder chose this animal because it is genetically far removed from primates, and because it is one of the most endangered species on the planet. There are only seven animals still in existence, two of which reside at the San Diego Zoo Safari Park.
Initially members of the team thought they would have to isolate and use genes from animals closely related to the endangered species to successfully induce pluripotency. But that line of experimentation didn't work. Instead, to their surprise, after a year of trial and error, the researchers found that the same genes that induce pluripotency in humans also worked for the drill and the rhino. "It has been just amazing," said Ryder of the Scripps Research team's successes.
The process is inefficient, meaning only a few stem cells are produced at a time, but that's enough. "There are only two animals in it," said Ben-Nun, "but we have the start of a new zoo, the stem cell zoo."
Stem Cells to the Rescue
The scientists view their success as a first step toward greater advancements. Besides the possibility of using stem cells as the basis for diabetes or other treatments, there is great potential for new reproductive technologies as the stem cell research field advances. "The most important thing is to provide these stem cells as a resource for other people taking some of the next steps," said Loring.
One of the greatest concerns with small populations such as the northern white rhinos is that even if they did reproduce, which hasn't happened in many years, their genetic diversity is inevitably and dangerously low, and such inbreeding leads to unhealthy animals.
But researchers are moving toward inducing stem cells to differentiate into sperm or egg cells. With that accomplished, one possibility is that scientists could take skin cells in the Frozen Zoo from long dead animals, induce pluripotency, trigger differentiation into sperm cells, and then combine these with a living animal's eggs through in vitro fertilization. Otherwise-lost genetic diversity would then be reintroduced into the population, making it healthier, larger, and more robust.
Or, both eggs and sperm might be produced from the stem cells, with the resulting embryos implanted in live animals, a process that current research suggests could be much more reliable than existing cloning techniques.
Scientists are already exploring the possibility of producing sperm and eggs from stem cells as a potential solution to human infertility issues. Loring hopes that some of these groups might consider initial technique development using endangered species stem cells. "I think that work would be a lot easier ethically with endangered species than with humans," she said, "so I suspect some people working in this area would love to have our cells for experiments."
The Real Solution
"The best way to manage extinctions is to preserve species and their habitats," said Ryder, "but that's not working all the time." The rhinos are a perfect example, he said, because there are so few. "Stem cell technology provides some level of hope that they won't have to become extinct even though they've been completely eliminated from their habitats. I think that if humankind wants to save this species, we're going to have to develop new methodologies."
And even when there are reasonable wild populations of a species, they face a range of threats, including loss of habitat and poaching.
Moving forward, Loring said the group is hoping to continue producing stem cells from other species to expand their fledgling stem cell "zoo." For now, they're working to secure funding for what amounts to an unconventional line of research. "It's in between fields," said Loring. "It's not classical conservation and it's not ordinary biological research."
This research was supported by the Esther O'Keefe Foundation, the Millipore Foundation, and the California Institute for Regenerative Medicine.
http://www.sciencedaily.com/releases/2011/09/110904140411.htm
Showing posts with label stem cells. Show all posts
Showing posts with label stem cells. Show all posts
Tuesday, September 6, 2011
Tuesday, June 28, 2011
Test-tube hamburger - a taste of things to come
CALLING all fast-food addicts - a human guinea pig is wanted to become the first person in the world to eat a test-tube hamburger.
The burger, made with beef mince grown from stem cells, is less than a year away from being produced, Dutch scientists say. And they believe it could pave the way for eating meat without the need for animals being slaughtered.
The scientists predict that over the next few decades the world's population will increase so quickly that there will not be enough livestock to feed everyone.
As a result, they say, laboratory-grown beef, chicken and lamb could become normal. The scientists are currently developing a burger which will be grown from 10,000 stem cells extracted from cattle, which are then left in the lab to multiply more than a billion times to produce muscle tissue similar to beef. The product is called in vitro meat.
Mark Post, professor of physiology at Maastricht University in the Netherlands, who is behind the project, said: "I don't see any way you could rely on old-fashioned livestock in the coming decades. In vitro meat will be the only choice left.
"We are trying to prove to the world we can make a product out of this, and we need a courageous person who is willing to be the first to taste it.
"If no one comes forward, then it might be me."
Professor Post told Scientific American magazine that he thought the first test-tube burger could be made within 12 months. In 2009, scientists from the same university grew strips of pork using the same method. They admitted it was not particularly appetising, being grey with a similar texture to calamari.
Fish fillets have been grown in a New York laboratory using cells taken from goldfish muscle tissue.
Even if the initial results do not taste quite the same as proper meat, scientists are convinced the public will soon get used to it.
The world's meat consumption is expected to double by 2050. The scientists believe that the test-tube burger is only the first stage in a food revolution that might solve the problem.
http://www.dailytelegraph.com.au/news/test-tube-hamburger-a-taste-of-things-to-come/story-e6freuy9-1226083075037
Tuesday, November 2, 2010
Miniature livers 'grown in lab'
Scientists have managed to produce a small-scale version of a human liver in the laboratory using stem cells.
The success increases hope that new transplant livers could be manufactured, although experts say that this is still many years away.
The team from Wake Forest University Baptist Medical Center presented its findings at a conference in Boston.
UK experts said it was an "exciting development" but it was not yet certain a fully-functioning liver was possible.
The demand for transplant livers far exceeds the number of available organs, and in recent years, research has focused on ways to use cell technology to support failing organs in the body, or even one day replace them.
Their building block is the stem cell, a "master cell" which can, in certain conditions, divide to produce different types of body tissue.
However, constructing a three-dimensional organ from stem cells is a difficult task.
'Technical hurdles'
The method used by the Wake Forest researchers, and other teams around the world, is to form new liver tissue on a scaffold made from the structure of an existing liver.
In this case, a detergent was used to strip away the cells from the liver, leaving only the collagen framework which supported them, and a network of tiny blood vessels.
The new stem cells - in this case, immature liver cells and endothelial cells, to produce a new lining for the blood vessels - were gradually introduced.
After a week in a "bioreactor", which nurtured the cells with a mixture of nutrients and oxygen, the scientists saw widespread cell growth within the structure, and even signs of some normal functions in the tiny organ.
Professor Shay Soker, who led the research, said: "We are excited about the possibilities this research represents, but must stress that we're at an early stage, and many technical hurdles must be overcome before it could benefit patients.
"Not only must we learn how to grow billions of liver cells at one time in order to engineer livers large enough for patients, we must determine whether these organs are safe to use."
UK researchers welcomed the findings, which are being presented to the American Association for the Study of Liver Diseases. Professor Mark Thursz, from Imperial College London, said the results were "encouraging".
"The report suggests that the authors have overcome one of the major hurdles in creating an artificial liver - to generate functioning human liver cells in a 'natural' liver structure.
"It is clear that the cells are growing well, but the next step is to show that they are functioning like normal human liver tissue."
Dr Mark Wright, from Southampton University added: "In an era of increasing liver disease and death with a chronic shortage of liver transplants this represents an exciting development in an important field of work.
"The researchers appear to have made the step of combining stem cell technology with bioengineering as a first step to producing artificial livers.
"Whilst 'off the shelf' new livers are clearly still a long way off, this work gives a glimmer of hope that this is no longer just the stuff of science fiction."
The success increases hope that new transplant livers could be manufactured, although experts say that this is still many years away.
The team from Wake Forest University Baptist Medical Center presented its findings at a conference in Boston.
UK experts said it was an "exciting development" but it was not yet certain a fully-functioning liver was possible.
The demand for transplant livers far exceeds the number of available organs, and in recent years, research has focused on ways to use cell technology to support failing organs in the body, or even one day replace them.
Their building block is the stem cell, a "master cell" which can, in certain conditions, divide to produce different types of body tissue.
However, constructing a three-dimensional organ from stem cells is a difficult task.
'Technical hurdles'
The method used by the Wake Forest researchers, and other teams around the world, is to form new liver tissue on a scaffold made from the structure of an existing liver.
In this case, a detergent was used to strip away the cells from the liver, leaving only the collagen framework which supported them, and a network of tiny blood vessels.
The new stem cells - in this case, immature liver cells and endothelial cells, to produce a new lining for the blood vessels - were gradually introduced.
After a week in a "bioreactor", which nurtured the cells with a mixture of nutrients and oxygen, the scientists saw widespread cell growth within the structure, and even signs of some normal functions in the tiny organ.
Professor Shay Soker, who led the research, said: "We are excited about the possibilities this research represents, but must stress that we're at an early stage, and many technical hurdles must be overcome before it could benefit patients.
"Not only must we learn how to grow billions of liver cells at one time in order to engineer livers large enough for patients, we must determine whether these organs are safe to use."
UK researchers welcomed the findings, which are being presented to the American Association for the Study of Liver Diseases. Professor Mark Thursz, from Imperial College London, said the results were "encouraging".
"The report suggests that the authors have overcome one of the major hurdles in creating an artificial liver - to generate functioning human liver cells in a 'natural' liver structure.
"It is clear that the cells are growing well, but the next step is to show that they are functioning like normal human liver tissue."
Dr Mark Wright, from Southampton University added: "In an era of increasing liver disease and death with a chronic shortage of liver transplants this represents an exciting development in an important field of work.
"The researchers appear to have made the step of combining stem cell technology with bioengineering as a first step to producing artificial livers.
"Whilst 'off the shelf' new livers are clearly still a long way off, this work gives a glimmer of hope that this is no longer just the stuff of science fiction."
Miniature livers 'grown in lab'
Scientists have managed to produce a small-scale version of a human liver in the laboratory using stem cells.
The success increases hope that new transplant livers could be manufactured, although experts say that this is still many years away.
The team from Wake Forest University Baptist Medical Center presented its findings at a conference in Boston.
UK experts said it was an "exciting development" but it was not yet certain a fully-functioning liver was possible.
The demand for transplant livers far exceeds the number of available organs, and in recent years, research has focused on ways to use cell technology to support failing organs in the body, or even one day replace them.
Their building block is the stem cell, a "master cell" which can, in certain conditions, divide to produce different types of body tissue.
However, constructing a three-dimensional organ from stem cells is a difficult task.
'Technical hurdles'
The method used by the Wake Forest researchers, and other teams around the world, is to form new liver tissue on a scaffold made from the structure of an existing liver.
In this case, a detergent was used to strip away the cells from the liver, leaving only the collagen framework which supported them, and a network of tiny blood vessels.
The new stem cells - in this case, immature liver cells and endothelial cells, to produce a new lining for the blood vessels - were gradually introduced.
After a week in a "bioreactor", which nurtured the cells with a mixture of nutrients and oxygen, the scientists saw widespread cell growth within the structure, and even signs of some normal functions in the tiny organ.
Professor Shay Soker, who led the research, said: "We are excited about the possibilities this research represents, but must stress that we're at an early stage, and many technical hurdles must be overcome before it could benefit patients.
"Not only must we learn how to grow billions of liver cells at one time in order to engineer livers large enough for patients, we must determine whether these organs are safe to use."
UK researchers welcomed the findings, which are being presented to the American Association for the Study of Liver Diseases. Professor Mark Thursz, from Imperial College London, said the results were "encouraging".
"The report suggests that the authors have overcome one of the major hurdles in creating an artificial liver - to generate functioning human liver cells in a 'natural' liver structure.
"It is clear that the cells are growing well, but the next step is to show that they are functioning like normal human liver tissue."
Dr Mark Wright, from Southampton University added: "In an era of increasing liver disease and death with a chronic shortage of liver transplants this represents an exciting development in an important field of work.
"The researchers appear to have made the step of combining stem cell technology with bioengineering as a first step to producing artificial livers.
"Whilst 'off the shelf' new livers are clearly still a long way off, this work gives a glimmer of hope that this is no longer just the stuff of science fiction."
The success increases hope that new transplant livers could be manufactured, although experts say that this is still many years away.
The team from Wake Forest University Baptist Medical Center presented its findings at a conference in Boston.
UK experts said it was an "exciting development" but it was not yet certain a fully-functioning liver was possible.
The demand for transplant livers far exceeds the number of available organs, and in recent years, research has focused on ways to use cell technology to support failing organs in the body, or even one day replace them.
Their building block is the stem cell, a "master cell" which can, in certain conditions, divide to produce different types of body tissue.
However, constructing a three-dimensional organ from stem cells is a difficult task.
'Technical hurdles'
The method used by the Wake Forest researchers, and other teams around the world, is to form new liver tissue on a scaffold made from the structure of an existing liver.
In this case, a detergent was used to strip away the cells from the liver, leaving only the collagen framework which supported them, and a network of tiny blood vessels.
The new stem cells - in this case, immature liver cells and endothelial cells, to produce a new lining for the blood vessels - were gradually introduced.
After a week in a "bioreactor", which nurtured the cells with a mixture of nutrients and oxygen, the scientists saw widespread cell growth within the structure, and even signs of some normal functions in the tiny organ.
Professor Shay Soker, who led the research, said: "We are excited about the possibilities this research represents, but must stress that we're at an early stage, and many technical hurdles must be overcome before it could benefit patients.
"Not only must we learn how to grow billions of liver cells at one time in order to engineer livers large enough for patients, we must determine whether these organs are safe to use."
UK researchers welcomed the findings, which are being presented to the American Association for the Study of Liver Diseases. Professor Mark Thursz, from Imperial College London, said the results were "encouraging".
"The report suggests that the authors have overcome one of the major hurdles in creating an artificial liver - to generate functioning human liver cells in a 'natural' liver structure.
"It is clear that the cells are growing well, but the next step is to show that they are functioning like normal human liver tissue."
Dr Mark Wright, from Southampton University added: "In an era of increasing liver disease and death with a chronic shortage of liver transplants this represents an exciting development in an important field of work.
"The researchers appear to have made the step of combining stem cell technology with bioengineering as a first step to producing artificial livers.
"Whilst 'off the shelf' new livers are clearly still a long way off, this work gives a glimmer of hope that this is no longer just the stuff of science fiction."
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