A research team from UC Irvine's Sue & Bill Gross Stem Cell Research Center has found that stem cells derived from bone marrow may have the potential to treat stroke victims.
Neurologist Dr Steven Cramer and biomedical engineer Weian Zhao conducted an analysis of published research, identifying 46 studies that used mesenchymal stromal cells (MSCs) in animal models of stroke.
MSCs, which are a type of multipotent adult stem cells mostly processed from bone marrow, were found to be significantly better than control therapy in 44 of the studies.
Significantly, the effects of the cells on recovery were strong irrespective of the dosage, the time the MSCs were administered relative to stroke onset or the method of administration.
MSCs were effective whether introduced via the blood or the brain, even if they were administered a month after the event.
"Stroke remains a major cause of disability, and we are encouraged that the preclinical evidence shows [MSCs'] efficacy with ischemic stroke," said Dr Cramer, a professor of neurology and leading stroke expert.
"MSCs are of particular interest because they come from bone marrow, which is readily available, and are relatively easy to culture. In addition, they already have demonstrated value when used to treat other human diseases."
While MSCs transform into a wide variety of cell types, such as bone, cartilage and fat cells, they do not differentiate into neural cells.
The cells nevertheless play important roles in promoting brain repair following a stroke. They are attracted to injury sites and release a wide range of molecules in response to signals released by these damaged areas.
MSCs are responsible for a number of activities: blood vessel creation to enhance circulation, protection of cells starting to die and growth of brain cells, among others.
When MSCs are able to reach the bloodstream, they gather in parts of the body that control the immune system and help to create an environment that is more conducive to brain repair.
Dr Cramer said the findings could form the basis of further studies on the use of MSCs in the treatment of ischemic stroke in humans.