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Altered cells may repair brain damage
By WES ALLISON
© St. Petersburg Times, published August 2, 2000
TAMPA -- Like tiny spare tires, stem cells harvested from bone marrow may be used to replace brain cells ravaged by Parkinson's, stroke and other neurological diseases, researchers at the University of South Florida have discovered.
Their findings, published as the lead article in this month's issue of Experimental Neurology, indicate the cells that help make bone and muscle can be reprogrammed to act like nerve cells.
Although actual treatments from this research are likely several years away, the discovery is significant because it adds to growing evidence that stem cells are blank slates and may be manipulated to take on a variety of characteristics.
These altered cells then may be used to replace damaged cells to treat a wide range of ailments, from spinal cord injury to brain trauma and even Alzheimer's.
The USF scientists, led by Dr. Juan Sanchez-Ramos and Dr. Paul R. Sanberg, were able to turn human and mouse stem cells into neurons, a key type of brain cell. They are now experimenting with ways to transplant them into rat brains to see how they work.
"The very fact that bone marrow cells contain within them (a cell) that can be induced to become a neuron may revolutionize the treatment of neurological disorders," said Sanchez-Ramos, the Helen Ellis Professor of Parkinson's Research at USF.
It could be helpful "anywhere there's a tissue loss due to injury, infection or unknown (problems)," he said. "In the long run, it may change the way we do everything."
The discovery also gives scientists a safe, reliable source for stem cells. Such cells have been harvested from fetuses and embryos, which is ethically and politically contentious. And stem cells taken from animals often don't perform well in humans.
"With this, the fact that you can do it from (marrow) donations or the person's own cells makes it a lot easier," said Sanberg, professor and research director for USF's Department of Neurosurgery. "And we know a lot about bone marrow. Bone marrow transplants are being done every day."
In their experiments, the USF scientists harvested stromal cells from bone marrow and added growth factors to help them multiply. They then added chemicals required for the normal development of neurons.
The resulting cells look and appear to act like immature nerve cells. How well they work in the brain will depend, in part, on whether cells are genetically predisposed to perform specific functions, or if they can be shaped to do about anything.
Sanchez-Ramos figures it's probably a combination, but he argues that the cell's environment is likely the biggest factor.
He likens the bone marrow stem cells to an impressionable child: At birth, his possibilities are virtually endless. But as time passes and his environment begins to mold him, some options become more likely than others.
"When you're 30 years old and you have just begun to focus on, say, driving really fast cars, it would be unlikely that you would become a physician," Sanchez-Ramos said.
"We're starting with very, very early cells that are uncommitted, and we're putting them in a very specialized environment so they become neurons. It's like starting with a child and turning him into a brain -- an intellectual."
Dr. John R. Sladek Jr., editor-in-chief of Experimental Neurology and chairman of the Department of Neuroscience at the Chicago Medical School, said he has no reason to think the altered stem cells won't work well as neurons.
Scientists have long known that nerve cells are easily influenced by their environment, he said.
"If they can take this to the next level -- and the next step would be to test if these cells would transplant successfully and transform into the right kind of cell, and demonstrate that these are every bit as good as embryonic cells that are taken from the brain -- I think we're extremely close to a new form of therapy," Sladek said.
This marks the second major announcement by USF neurology researchers this year. Earlier, Sanberg revealed that nicotine may ease symptoms of Tourette's syndrome, a rare disease that causes twitching and sudden, inappropriate outbursts.
USF researchers also are participating in a study that involves inserting fetal stem cells from a pig into the brains of patients with Parkinson's disease. They hope the pig cells will help rejuvenate the deteriorating areas of their brains.
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