Grant: Canada Postdoctoral Research Award (CPRA) program

Multiple sclerosis is an inflammatory and neurodegenerative disease that leads to progressive disability. The immune system normally protects us against infections and tumors. However, in people with MS, immune cells enter the brain and the spinal cord, where they attack the myelin sheath. This sheath surrounds and protects neurons, allowing them to function properly. The loss of the myelin sheath, called demyelination, is responsible for many MS symptoms. Most treatments currently available act by blocking immune cells from entering the brain and the spinal cord. While effective, their efficacy decreases with age, and they can cause significant side effects. Sex differences also play a role in MS. While three out of four patients are women, men tend to recover less well after relapses than women, possibly because of less repair of the lesions. This underlines the importance of finding new ways to promote the repair of the myelin sheath, a process called remyelination, in people living with MS. Reducing methionine - an amino acid present in high amount in meat - consumption in animal models can prolong lifespan and reduce general inflammation. Our team has already demonstrated that dietary methionine restriction can reduce MS severity in animal models, by lowering inflammation. We now want to determine whether this diet can also stimulate the repair of the myelin sheath in the brain, using models of both acute and chronic demyelination, in male and female individuals. Importantly, this project is directly connected to an ongoing clinical trial of dietary methionine restriction in humans, allowing rapid translation of our findings. It could lay the foundation for a non-pharmacological treatment in MS, to both decrease inflammation and promote myelin repair, improving the quality of life for people living with MS.