By Maggie Fox, Health and Science Correspondent
WASHINGTON (Reuters) - Researchers said Monday they had
coaxed master cells from bone marrow into becoming nerve cells, and said they
hoped they could use these cells to treat conditions ranging from paralysis to
Alzheimer's disease.
The team at the University of Medicine and Dentistry of
New Jersey say they developed a culture that makes stem cells— the so-called
master cells of the body—turn into nerve cells "like wildfire."
They hope their formula can be used to help produce treatments
using a patients' own cells. These
cells grow like wildfire in culture, so we have a virtually unlimited supply,
Dr. Ira Black, chairman of the department of neurosciences at the university,
said in a telephone interview.
Stem cells have been the subject of intense study by scientists,
who hope that they can be used to grow tissue and perhaps even organs on
demand, if only they can learn the secret of how to direct their growth.
Black's team worked with stromal stem cells, which are found
in the bone marrow and which give rise to bone, muscle, fat and certain other
kinds of cells.
Writing in the Journal of Neuroscience Research, the researchers
said they started out with rat stem cells grown in the laboratory, and then
confirmed their findings using human stem cells in lab dishes.
The secret to making them grow, Black said, was in the growth
medium used to keep and grow cells in labs.
"It is a combination of ingredients that we used," he said. These included antioxidants, which had been
shown to help neurons live and grow, and growth factors such as fibroblast growth
factor (FGF).
"Now we have the optimal medium which results in the conversion
of 80 percent of the cells into neurons, which in this area is astronomically
high."
Now they are testing to see what the cells can do. We are transplanting the cells into live
rats and initially we've begun with normal rats to answer some very simple
questions—will the cells survive in various areas of the brain and the spinal
cord and the answer is yes they do," Black said.
So far they have lived for months, without causing any detectable
ill-effects in the rats, he said.
Next they will test the cells in animals with Alzheimer's,
stroke, Parkinson's disease and spinal cord injuries. Other studies have suggested that injured cells send out chemical
calls for help to which stem cells can respond. One study has shown stem cells
migrating through the brain and replacing damaged cells.
Black said it might be possible to grow these cells,
inject them into an injured spinal cord or damaged brain, and watch them go to
work repairing damage. It is more likely, however, that scientists will have to
help out the stem cells a little bit.
"I think it will be combination of different approaches that
ultimately will work," Black said.
"We have found that the spinal cord contains special
growth factors that enhance the regrowth of damaged neurons. In addition, there
are inhibitory factors that prevent regrowth, so probably the ultimate therapy,
which none of us can picture yet, would be a combination of the use of cells,
stimulation factors and the inhibition of antagonistic factors." Black, who also works at the Robert Wood
Johnson Medical School at Rutgers University, said the university had applied for
a patent on the special growth medium.
The Christopher Reeve Paralysis Foundation, which helped fund the study
along with the National Institutes of Health, welcomed the findings.
"The possibilities for spinal cord and brain repair suggested
by this study are quite profound," Susan Howley, executive vice president and
director of research at the foundation, said in a telephone interview. Now ... we need to see if these cells
help to promote functional recovery."
Reeve, an actor paralyzed in a riding accident, recently told
Congress he hopes stem cell research will cure him.