A global research team has identified a novel mechanism connecting stress-related psychiatric disorders to immune system irregularities.
First author Flurin Cathomas said, “We were able to show that stress increases the amount of the matrix metalloproteinase-8 (MMP-8), an enzyme in the blood of mice. The same changes were found in patients with depression.”
MMP-8 migrates from the bloodstream to the brain, causing changes in the functioning of specific neurons. In mice affected by this, it results in behavioral alterations such as withdrawal and social avoidance.
Cathodes said the findings are novel in two respects, “Firstly, they indicate a new ‘body-mind mechanism,’ which might be relevant not only for stress-related mental illness, but also for other diseases that affect both the immune and nervous systems.” Secondly, identification of the specific MMP-8 protein could be a potential starting point to develop new treatments for depression.
“If MMP-8 penetrates the brain tissue from the blood, it changes the matrix structure and thus disrupts the functioning of the neurons. Mice who are affected by this process display changes in behavior that are similar to those seen in humans with depression,” says Cathomas.
More studies are needed before the results can be implemented in clinical practice. Cathomas said, “Our work once again once again demonstrates the importance of the interaction between the immune system and the brain in the development of psychiatric disorders. These insights are already being incorporated into psychiatric treatment today.”
