Neuroscientists continue to seek alternatives to human embryonic neurons as a source of therapeutic cells for brain repair, said Paul Sanberg, PhD, DSc, director of the USF Neurosciences Program and a study co-author. Bone marrow stem cells offer several potential advantages, he said. The cells are readily accessible since they are already collected from bone marrow donors for certain cancer treatments. And, stem cells can be extracted from a patient's own bone marrow, so they are less likely to be rejected than neural cells coming from other sources. Stem cells are primitive cells, present in developing embryos, that can multiply indefinitely, migrate to different parts of the body and develop into any kind of tissue.
Bone marrow retains the ability to generate stem cells throughout life.
Left to their own devices, these bone marrow stem cells typically give rise to bone, blood and cartilage. They express several neural proteins. Furthermore, when these transformed bone marrow cells were combined with fetal rat brain tissue in a petri dish, the number of neuron-like cells doubled. Last year, Italian and Canadian scientists reported that neural stem cells from mice changed their identities and began to make bone marrow when injected into other mice whose bone marrow stem cells had been virtually destroyed by radiation. The USF researchers have begun cloning the stem cells and transplanting them into an animal model for stroke to see if they can replace damaged brain tissue.