Researchers at the Center for Gene Therapy at Tulane University discovered that human stem cells derived from bone marrow and injected directly into the brains of mice can reduce the damage caused by a stroke.
The team found that the stem cells trigger biochemicals from microglia and macrophages that reduce inflammation and protect neurons. They showed that stem cell injection reduced the number of dying or damaged neurons in mice.
The scientists also investigated how the expression of cerebral genes changed in mice briefly deprived of blood flow to the brain. The authors found that 586 genes were expressed at higher levels after the flow was halted. When stem cells were injected into the brains of the mice, however, 10% fewer genes were upregulated. The reasearchers suggest that those genes are likely involved in inflammatory and immune responses.
The study appears in PNAS.