Scientists have identified a gene that helps regulate how well nerves of the central nervous system are insulated, researchers at Washington University School of Medicine in St. Louis report. Healthy insulation is vital for the speedy propagation of nerve cell signals. The finding, in zebrafish and mice, may have implications for human diseases like multiple sclerosis (MS), in which this insulation is lost. The study appears in Nature Communications.
The research focused on a gene called Gpr56, which manufactures a protein of the same name. Previous work indicated that this gene likely was involved in central nervous system development, but its specific roles were unclear. In the new study, the researchers found that when the protein Gpr56 is disabled, there are too few oligodendrocytes to provide insulation for all of the axons. Still, the axons looked normal. And in the relatively few axons that were insulated, the myelin also looked normal. But the researchers observed many axons that were simply bare, not wrapped in any myelin at all.
Without Gpr56, the cells responsible for applying the insulation failed to reproduce themselves sufficiently, according to senior author Kelly R. Monk, PhD. These cells actually matured too early instead of continuing to replicate as they should have. Consequently, in adulthood, there were not enough mature cells, leaving many axons without insulation.
Monk also says that Gpr56 belongs to a large class of cell receptors that are common targets for many drugs, making the protein attractive for further research. The investigators point out its possible relevance in treating diseases associated with a lack of myelin, including multiple sclerosis.
“In the case of MS, there are areas where the central nervous system has lost its myelin,” Monk says. “At least part of the problem is that the precursor myelin-producing cells are recruited to that area, but they fail to become adult cells capable of producing nerve cell insulation. Now, we have evidence that Gpr56 modulates the switch from precursor to adult cell.”Read the article preview on the Nature Communications website