Proteins which block remyelination in MS discovered
Proteins called tenascins block the body’s ability for remyelination, a study on mice has revealed.
Remyelination – the growing back of the myelin sheath that surrounds the nerves and was damaged by multiple sclerosis (MS) – is considered the holy grail in future treatment by many scientists. First, more is needed to be known about why the process can be impaired.
Researchers in this latest study found that tenascins block the regrowth of myelin by modulating oligodendrocytes. They set up experiments to discover how two tenascin proteins, tenascin-C and tenascin-R, affect myelin repair. These proteins are part of the network of proteins and other molecules that assist in giving structure to tissues and regulating cellular activity called the extracellular matrix.
The scientists gave mice chemicals to induce myelin loss. The mice were genetically engineered to make either of the two proteins and compared to normal mice. The mice who were unable to make the proteins had much thicker myelin sheaths than the normal mice after demyelination had occurred.
Further analysis found that the tenascin-lacking mice, particularly those lacking tenascin C, had greater amounts of myelin-making oligodendrocytes, and immature cells called oligodendrocyte precursor cells (OPCs), in the brain and spinal cord.
“The impact of the extracellular matrix on the restoration of myelin membranes is enormous and could become a key target for therapy,” the researchers said.