Multiple Sclerosis: A Study Confirms the Involvement of the Intestine in its Development
In a new study, German researchers have identified cellular phenomena that occur in the gut and may influence the development of multiple sclerosis.
In recent years, much research has highlighted and improved understanding of the bowel-brain connection, and the influence of the gut microbiota on brain health and morale, among others.
Also, by its important connections with the brain system, the intestine is suspected to play a significant role in the onset and progression of neurodegenerative and / or autoimmune diseases. This is particularly the case of multiple sclerosis, where the immune system reacts abnormally and attacks myelin, a substance that forms a protective sheath around the nerves.
A neurology team at the St Josef Hospital in the Ruhr-University Bochum, Germany, has shown a mechanism that partly explains the influence of the gut on the development of multiple sclerosis (MS). In a study published in PNAS, the team used a mouse model to show that a protein, called Smad7, mobilized some immune cells in the gut, which then triggered inflammation of the central nervous system (CNS). The most marked clinical symptoms, similar to those of MS, appeared in mice with high levels of Smad7 in the type T immune cells studied here and present in the intestine. They then migrated into the CNS where they caused inflammation. In mice genetically engineered to be free of Smad7 protein, no evidence of MS-like disease has occurred.
In a second step, the researchers analyzed tissue samples taken from the intestines of 27 patients with multiple sclerosis, and compared these samples to those of 27 healthy individuals. The comparison made it possible to find results similar to those obtained in the mouse: the Smad7 signal protein appeared more frequently in intestinal mucosal samples from MS patients than in those from healthy persons.
“For other autoimmune diseases such as Crohn’s disease and other inflammatory bowel diseases, researchers already know that Smad7 is a promising therapeutic target; our results suggest that the same is true for multiple sclerosis, “said Ingo Kleiter, co-author of the study. “Researchers are increasingly exploring the involvement of the gut in the development and progression of MS,” added Simon Faissner. This protein could therefore be a therapeutic target for new treatments aimed at reducing the progression of multiple sclerosis.