WEST LAFAYETTE, Ind. -- Researchers have discovered that calcium ions could play a crucial role in multiple sclerosis by activating enzymes that degrade the fatty sheath that insulates nerve fibers.
Learning exactly how the myelin sheath is degraded might enable scientists to determine how to halt disease progress and reverse damage by growing new myelin, said Ji-Xin Cheng, an assistant professor in Purdue University's Weldon School of Biomedical Engineering and Department of Chemistry.
"Although multiple sclerosis has been studied for many years, nobody knows exactly how the disease initially begins," he said. "The pathway is not clear."
Purdue researchers used an imaging technique called coherent anti-Stokes Raman scattering, or CARS, to study how the myelin sheath is degraded by a molecule called lysophosphatidylcholine, known as LPC. The LPC does not cause multiple sclerosis, but it is used extensively in laboratory research to study the deterioration of myelin, which insulates nerve fibers and enables them to properly conduct impulses in the spinal cord, brain and peripheral nervous system throughout the body.
The findings suggest that LPC causes sheath degradation by allowing an influx of calcium ions into the myelin. The increased concentration of calcium ions then activates two enzymes - calpain and cytosolic phospholipase A2 - which break down proteins and molecules in the myelin called lipids.
"It is possible that the same pathway causes myelin degradation in people suffering from multiple sclerosis and spinal cord injuries," Cheng said.
The research demonstrates that CARS microscopy is a valuable research tool and could become a future clinical method to diagnose multiple sclerosis and detect damage to the spinal cord from accident trauma, which also causes the myelin to degrade, he said.