In multiple sclerosis, or MS, the insulating sheaths around nerve cells in the brain and spinal cord called myelin become damaged. This degradation results in nerve cells losing their ability to transmit signals efficiently, leading to a multitude of devastating physical, mental and even psychiatric symptoms. In the U.S. alone, over a million people over 18 have been diagnosed with MS.
MS is an immune-mediated disorder; an onslaught of the body’s own T cells targets and destroys the outer layers of neurons. However, the triggers and the intricate interplay between genetic and environmental factors that increase one’s risk of MS development are still undefined. Just how and why MS occurs remains a mystery.
For scientist Helmut Butzkueven at Monash University’s Department of Neuroscience, unraveling the secrets held by this debilitating disease has remained a focus for many years. After almost a decade of work, Butzkueven and colleagues have made a breakthrough in mapping the big picture of MS, with some surprising revelations. The work was featured in the journal Life Science Alliance.
For one, both the adaptive and innate immune systems were shown to play a role in disease development. It’s not just T cells that are the culprits. In fact, other immune cells are also involved in the attack on neurons.
Fascinatingly, the team also uncovered some novel links between environmental factors and MS onset. “Currently, we are looking at how this gene expression network interacts with environmental factors, which could be modified to stop the development of MS,” said Butzkueven.
“For example, MS is much more common in the lower latitudes of Australia, being 7 times more common in Victoria than in North Queensland. This strongly suggests that the genetic functions we have mapped interact with the environment. One of the lead candidates is sunlight and vitamin D.”
Vitamin D is synthesized in the skin through a chemical reaction that relies on sun exposure. Being deficient in this vitamin has been linked to a higher chance of developing MS, however, how this is linked to immune cell activity remains a question mark. The scientists’ next steps are to go down this path of inquiry.
“We are now concentrating on linking our 'gene function map' with vitamin D biology and exposure data to climb the next rung of knowledge,” comments Butzkueven, adding, “At the end of this mysterious ladder is the big answer all our patients ask when they are diagnosed: 'What causes MS and why did I get it'?”