Researchers at Texas A&M have shown that adult stem cells injected into the brain can repair stroke damage. They injected human bone marrow stem cells into the brains of mice that had induced stroke, and found that the adult stem cells could alleviate the damage caused by the stroke. Their study, published in the Proceedings of the National Academy of Sciences, also indicated the mechanism of action of the adult stem cells in the brain. Previous studies have shown that mesenchymal stromal cells (a type of bone marrow stem cell) can reverse neural degeneration in the brain caused by disorders such as Parkinson's disease and stroke, but the mechanism was unclear. Dr. Darwin Prockop, the senior investigator, noted that "Our paper provides for the first time a molecular explanation of how adult stem/progenitor cells can ameliorate ischemic (reduced blood flow) damage to the brain." The adult stem cells act primarily by signaling other cells in the brain, stimulating the brain cells to block inflammation that can lead to cell damage and death. Stroke is the third leading cause of death in the U.S. This result, and the mechanism uncovered for adult stem cells, could lead to significant treatments not only for stroke and other brain disorders, but also for diseases and injuries to other tissues throughout the body.

prockop.jpgWhile not the first to suggest this mechanism of action for adult stem cells, Dr. Prockop has been a leader in investigating the actions of adult stem cells to repair tissue damage. Previous research includes the potential of adult stem cells to stimulate repair of the pancreas and kidney, to promote growth of new neural stem cells in the brain, and to form new airway cells for potential lung repair. One of his recent papers discussed at length the potential mechanisms used by adult stem cells for tissue repair.