Spinal damage paralyzes people and drastically changes their lives. Healing people with spinal cord injuries could restore motility to paralyzed people. However, this is a very complicated bit of treatment, and a deal of work needs to be done. A result that might bring us closer to that goal comes from the University of Texas. Researchers at the University of Texas Health Science Center at Houston have shown that in spinal cord-damaged rats, transplantation of genetically modified adult stem cells can help restore movement (published in the Feb. 24 issue of the Journal of Neuroscience).
Spinal cord injury causes “demyelination.” This 50-cent words simply means the destruction of the sheath that surrounds the long bits of that extend from neurons in the central nervous system. This sheath is composed of a protein called myelin, and this myelin sheath is produced by special cells called oligodendrocytes. Oligodendrocytes wrap around the axons of nerves and augment the conduction of nerve impulses through nerve cell axons. Without myelin sheaths, the nerves cannot send messages to make muscles move.
Qilin Cao, M.D.,and his colleagues discovered that transplanted adult stem cells called oligodendrocyte precursor cells (or OPCs) from the spinal cord could become mature oligodendrocytes. The new cells could form myelin sheaths and help restore electrical pathways through the spinal cord. This process, whereby oligodendrocytes make the myelin sheath is called “remyelination.”
Cao and his co-workers isolated oligodendrocyte precursor cells from adult spinal cord and before they transplanted them, they genetically modified them to express a special protein called ciliary neurotrophic factor (CNTF), a protein that encourages nerve growth. CNTF facilitates survival and differentiation of Oligodendrocyte Precursor Cells in cell culture. Perhaps the most important result is that the demyelination coincided exactly with the anatomical location where they were needed.
This study confirms stem cell grafting in attempts to remyelinate an injured spinal cord is a viable therapeutic strategy. Secondly, it also shows that recovery regenerative treatments will require more than simply grafting naïve precursor cells.