A new study in the Journal of Cell Biology suggests that vitamin D activates a receptor involved in myelin regeneration in patients with multiple sclerosis (MS). The study, entitled “Vitamin D receptor–retinoid X receptor heterodimer signaling regulates oligodendrocyte progenitor cell differentiation,” and was led by researchers at the University of Cambridge, United Kingdom.
In MS, the body’s own immune system attacks and destroys the myelin layer, the sheath that covers and protects nerve fibers. The body has natural mechanisms to repair myelin, however, with age these become less effective.
Researchers found that the vitamin D receptor interacts with a protein called the RXR gamma receptor, which has already been reported to play a role in myelin repair. In their experiments, researchers added vitamin D to brain stem cells (where both vitamin D and RXR gamma receptors are present) and found a significant increase (80%) in the production of oligodendrocytes, which are the cells that generate myelin. When vitamin D receptor activity was blocked, the RXR gamma protein was unable, by itself, to induce the production of oligodendrocytes.
“For years scientists have been searching for a way to repair damage to myelin. So far, the majority of research on vitamin D has looked at its role in the cause of the disease. This work provides significant evidence that vitamin D is also involved in the regeneration of myelin once the disease has started. In the future we could see a myelin repair drug that works by targeting the vitamin D receptor,” said the study’s senior author, Professor Robin Franklin, of the MS Society Cambridge Centre for Myelin Repair and the Wellcome Trust-Medical Research Council Stem Cell Institute at the University of Cambridge, in a news release.
The research team believes that vitamin D plays a role in myelin regeneration and that it can offer new approaches for remyelination therapies.
“More than 100,000 people in the UK have multiple sclerosis and finding treatments that can slow, stop or reverse the worsening of disability is a priority for the MS Society. We’d now like to see more studies to understand whether taking vitamin D supplements could, in time, be an effective and safe treatment for people with MS,” said Dr. Susan Kohlhaas, head of Biomedical Research at the MS Society. “For now though, this is early stage research that’s been done in the laboratory and more work is needed before we know whether it would hold true in people with MS. It’s not a good idea, however, to be deficient in vitamin D and we’d encourage anybody who thinks they might be to speak to their GP [general practitioner].”
A next step is to understand in more detail the biology of both vitamin D and RXR gamma receptors, so that future studies can focus on how the vitamin D receptor could be an effective target in MS patients.