Stroke Victim, Heal Thyself
April 5, 2001 -- Despite years of research, only one drug is available to reduce the amount of damage to the brain when someone has a stroke, and attempts to repair damaged brain cells have been largely unsuccessful. Now, for the first time, researchers have used cells from bone marrow to reverse disability following stroke in rats.
"This is a novel and important way to treat neurological injury and neurological disease, including stroke, spinal cord injury, and traumatic brain injury," author Michael Chopp, PhD, professor and vice chairman of neurology at Henry Ford Health Sciences Center in Detroit, tells WebMD. Chopp and fellow researchers published their results in the April issue of Stroke, Journal of the American Heart Association.
Researchers induced stroke in rats, then removed bone marrow cells and grew them in the laboratory. Like fetal cells, bone marrow cells can mature into a whole host of other cells when they're needed, making them potentially useful in treating different types of injury.
When the cells were injected back into the rats' veins, they zeroed in on the stroke-ravaged areas in the brain. Chopp calls them "smart cells." A few cells even began taking on some functions ordinarily carried out by nerve cells.
Compared with rats who did not get the bone marrow cells, rats injected with the experimental cells improved to near-normal levels within two weeks following stroke. They also had increased balance, coordination, and sensation.
"I would never have predicted that this would work, but something must have happened because the animals got better," Justin A. Zivin, MD, PhD, tells WebMD after reviewing the study.
"It's hard to understand how the cells get to the right place -- first they have to get into the brain, then they have to find the damaged areas and provide a beneficial effect once they get there," says Zivin, a professor of neuroscience at University of California, San Diego.
In other studies, cells from fetal tissue have been shown to improve function after brain injury, including stroke. However, using bone marrow cells has many potential advantages over fetal cells, including lack of rejection of the body's own tissue, and lack of ethical objections associated with using fetal tissue.
"It may not be necessary to limit our thinking ... to single sites of damage that can be specifically targeted in the central nervous system," Samuel Saporta, PhD, tells WebMD when asked for independent comment. "It may be sufficient to merely inject [cells] into the circulation and allow them to find all the sites in need of repair."
If so, injection of bone marrow cells might be helpful in multiple sclerosis and other neurological diseases where multiple sites are damaged, Saporta explains. He is a professor of anatomy and neurosurgery at the University of South Florida in Tampa.