Umbilical cord blood is generally known to contain hematopoietic stem cells that can only produce cells found in blood. The new findings, however, identify a small population of cord blood cells with the characteristics of more primitive stem cells that have the potential to produce a greater variety of cell types.
"We are excited by this discovery because it provides additional insight into how stem cells can restore function in the brain after injury," said Walter Low, Ph.D., senior investigator of the study, and professor of Neurosurgery and the Stem Cell Institute at the University of Minnesota.
This research was published in the latest issue of the journal Stem Cells and Development.
Transplantation of these human cord blood stem cells into laboratory rodents with experimental strokes resulted in significant reductions in the size of brain lesion, and improved these animals' use of their limbs.
Some of the transplanted stem cells developed into "neuron-like" cells that are typically found in the brain. In addition, the transplanted cells also induced an unanticipated reorganization of host nerve fibers within the brain, which may explain why the rats regained function, Low said.
Stroke is a neurological disorder that affects nearly 750,000 people in the United States each year. It can occur because of clots that form in blood vessels in the brain, or because of blood vessel rupture.