Stem Cells and Brain Lesions

The current issue of the STEM CELLS Translational Medicine journal contains a study involving a novel way of increasing the survival rate of stem cells injected into the brain.

Researchers harvested neural stem cells (NSC's) from baby mice and sorted the cells to find a predominance of stem cells containing CD15, a carbohydrate found on the surface of the cells that plays a very important role in cellular migration and adhesion, and in growth factor signaling that helps in cell maintenance and differentiation.  This sorting process allowed them to harvest a population of NSC's in which 98% of them were positive for the CD15 marker, approximately six times more than when the sorting method is not used.

These CD15 -positive cells were then differentiated in the lab, eventually resulting in neurons, astrocytes, and oligodendrocytes - these are specific types of cells found in our brain and spinal cord.  Neurons are the cells that process and transmit information, astrocytes are the most abundant cells that provide stuctural and metabolic support, and the oligodendrocytes provide support to and insulate our nerve cells.  These developed cells were then introduced into the brains of baby mice and studied over time, along with a control group of non-sorted neural cells.  Initially, both groups of cells were similar in the baby mice - one week later, when the brain was still growing, the cells in both groups had achieved similar population levels.  However, in adult mice the CD15-positive grafts showed significantly higher survival rates.  The cells with CD15 also tended to significantly differentiate into oligodendrocytes, cells that have a protective role for neurons.

The significance of this study is that it shows a potential method for improved deliverance of therapeutic cells to our brain and spianl cord. Anthony Atala, MD, edior of the journal and director of the Wake Forest Institute for Regenerative Medicine said "the fact that the CD15-positive cells show a significant increase in oligodendrocyte differentiation suggests that they may be particularly useful for treating diseases involving white matter lesions." White matter lesions are commonly associated with Alzheimer's Disease, multiple sclerosis, and stroke.  These types of lesions have also been found with infectious and inflammatory conditions, and even associated with patients experiencing migraine headaches.

Yet another bold step in the research of stem cells and possible therapeutic benefits!