How Stem Cells Repair Cellular Damage from a TBI
Stem cells harvested from adult bone marrow can be cued to grow into brain cells and then transplanted into the brain of a mammal in hopes of repairing brain damage from TBI or stroke.
In the past there were two theories regarding how the repair was done. One theory was that the transplanted stem cells grew new brain cells which replaced the dead or dying brain cells at the site of injury. The second theory was that the stem cells secreted a neural growth factor that helped the damaged cells heal.
In early October 2013 researchers led by Cesar Borlongan, PhD. at the University of South Florida published a paper in the online journal PLOS ONE setting out a third theory based on an experiment with rats. In the experiment they used two groups of rats with a TBI which displayed problems with movement and neurological function. One group received a stem cell transplant near the site of injured brain tissue, while the other received no treatment. The treated group showed good recovery of movement and neurological function, while the untreated group showed minimal recovery.
On autopsy the researchers found that the transplanted stem cells in the treated group had cued enhanced activity in the sub-ventricular zone of the rats’ brains, which pumped out new neurons, and the stem cells had also acted as a kind of “bio-bridge” to guide the movement of these freshly made brain cells to the site of brain injury. Based in part on this data the FDA recently approved a limited clinical trial to transplant SanBio Inc’s SB632 cells (an adult stem cell therapy) in patients with traumatic brain injury.