Newswise — Infections and neurodegenerative diseases cause inflammation in the brain. But for unknown reasons, patients with brain inflammation often develop muscle problems that seem to be independent of the central nervous system. Now, researchers at Washington University School of Medicine in St.
Louis have revealed how brain inflammation releases a specific protein that travels from the brain to the muscles and causes a loss of muscle function. The study, in fruit flies and mice, also identified ways to block this process, which could have implications for treating or preventing the muscle wasting sometimes associated with inflammatory diseases, including bacterial infections, Alzheimer’s disease and long COVID. The study is published July 12 in the journal Science Immunology.
“We are interested in understanding the very deep muscle fatigue that is associated with some common illnesses,” said senior author Aaron Johnson, PhD , an associate professor of developmental biology. “Our study suggests that when we get sick, messenger proteins from the brain travel through the bloodstream and reduce energy levels in skeletal muscle. This is more than a lack of motivation to move because we don’t feel well.
These processes reduce energy levels in skeletal muscle, decreasing the capacity to move and function normally.” To investigate the effects of brain inflammation on muscle function, the researchers modeled three different types of diseases — an E. coli bacterial.