From Bone Marrow to Brain Cells
Nov. 13, 2001 -- Normally, stem cells in adult bone marrow are destined to become cartilage, bone, fat, or muscle cells. But scientists have now successfully converted them into adult brain cells. This preliminary, but exciting, development could eventually bring a host of new treatment options for Parkinson's disease and other illnesses that cause damage to the nervous system over time.
In Parkinson's disease, the nerve cells, or neurons, that produce a key chemical messenger in the brain called dopamine die off. So researchers are now trying to figure out how to start with the body's stem cells and turn them into replacement dopamine neurons, says lead researcher Lorraine Iacovitti, PhD, in a news release. She is a researcher and professor of neurology at Jefferson Medical College of Thomas Jefferson University, in Philadelphia.
She presented her team's findings Nov. 11 at the annual meeting of the Society for Neuroscience in San Diego.
This latest research builds on earlier work in mice showing that bone-marrow stem cells from adult animals could be coaxed to mature into nerve cells if they were incubated in a specially prepared solution of growth factors and other nutrients. Using the same "nutrient potion" in their experiments on adult human stem cells, the researchers found that virtually all of the cells in the culture could be converted into neurons.
Unlike stem cells in adults, stem cells in embryos can turn into -- or differentiate -- into any type of cell that's needed. This makes them a rich, but highly controversial, resource for medical research. But continued success using adult stem cells could eliminate the debate entirely, while offering an important additional benefit. "The major advantage of using adult human bone-marrow stem cells is that each person can be his own donor," says Iacovitti. This would side-step the common and potentially deadly problem of tissue rejection.
The next big challenge, says Iacovitti, is getting the converted cells to remain neurons. Right now, they maintain their new identities only for about three days, before reverting back to undifferentiated stem cells.