In a new study, German researchers identified cellular phenomena in the intestine that may influence the development of multiple sclerosis.
In recent years, much research has been done to identify and improve the understanding of the intestinal-brain connection and the influence of the intestinal microbiota on brain health and mood in particular.
In addition, through its important connections to the brain, the gut is suspected of playing a significant role in the development and progression of neurodegenerative and/or autoimmune diseases. This is particularly true in multiple sclerosis, where the immune system reacts abnormally and attacks myelin, a substance that forms a protective sheath around nerves.
A neurology team at the Ruhr San Josef Hospital-University of Bochum, Germany, has identified a mechanism that would partially explain the influence of the intestine on the development of multiple sclerosis (MS). In a study published in the journal PNAS, the team used a mouse model to show that a protein, called Smad7, mobilized certain immune cells in the gut, which then triggered inflammation of the central nervous system (CNS). The most pronounced clinical symptoms, similar to those of MS, occurred in mice with high levels of Smad7 in the T-type immune cells studied here and present in the gut. They then migrated to the CNS, where they caused the inflammation. In rats genetically modified to be free of the Smad7 protein, there were no signs of MS-like disease.
In a second step, the researchers analyzed intestinal tissue samples from 27 patients with multiple sclerosis and compared these samples with those from 27 healthy individuals. The comparison showed results similar to those obtained in mice: the signaling protein Smad7 appeared more frequently in intestinal mucosal samples from MS patients than in healthy people.
“For other autoimmune diseases such as Crohn’s and other inflammatory bowel diseases, researchers are already aware that Smad7 offers a promising therapeutic target; our results suggest that the same is true for multiple sclerosis,” says study co-author Ingo Kleiter. As a result researchers are increasingly exploring bowel involvement in the development and progression of MS. Therefore, this protein could be a therapeutic target for new treatments aimed at reducing the progression of multiple sclerosis.