In multiple sclerosis (MS) and some other nervous system diseases the myelin sheath insulin around nerves gets damaged. Plus, as our brains age myelin sheath decays. So treatments useful for repairing the damage of MS will probably be useful for brain rejuvenation. Gotta love that. Anyway, oligodendrocyte cells make myelin sheath. So the ability to tell cells to become oligodendrocytes is needed for brain disease treatment and brain rejuvenation. Stanford researchers have found that a microRNA molecule called miR-219 tells precursor cells to become oligodendrocytes. An essential piece of the puzzle for myelin sheath repair treatments.
STANFORD, Calif. — About four out of every 10 cells in the brain are so-called oligodendrocytes. These cells produce the all-important myelin that coats nerve tracts, ensuring fast, energy-efficient transmission of nerve impulses. Mixed among them are proliferating but not particularly proficient precursor cells that are destined to become oligodendrocytes when needed but, for now, remain suspended in an immature, relatively undifferentiated state somewhere between stem cell and adult oligodendrocyte.
Stanford University School of Medicine scientists have now identified a molecular master switch that catalyzes these cells' transition to mature, myelin-making mavens. The results may have implications for medical treatment, as defects in this maturation process have been observed in both multiple sclerosis and the most common kind of brain cancers in adults, known as gliomas.
In a study to be published March 10 in Neuron, the investigators found that a molecule known as miR-219 is found at high levels only in oligodendrocytes, and that it is both necessary and sufficient to induce their relatively undifferentiated precursors to become functioning adult cells.
That miR-219 molecule is an example of a microRNA. DNA gets translated into RNA and RNA is used to make proteins and to regulate gene expression and other activities in the cell. The microRNA molecule identified here causes stem cells or other precursor cells to turn into oligodendrocytes.
Brain repair - whether for disease treatment or rejuvenation - is the hardest problem in body repair. For many types of organs development of replacements in vats using tissue engineering will eventually usher in an age of body repair much like car repair. Got a malfunctioning or failed part? Take it out and put in another one. But the very complex brain has got to be repaired in place using stem cell therapies, gene therapies, and microRNA therapies.