Stress talks to joints through brown fat — scientists trace the chain behind arthritis flare-ups

People with rheumatoid arthritis have long said stress brings their flare-ups on; now there is a mechanism. Chiba University researchers in Japan, publishing in Science Advances, traced the chain in mice: stress prompts brown fat — the heat-making fat near the shoulders — to release a signal molecule, interleukin-6, which tells joint-lining cells to call in inflammatory white blood cells, restarting swelling even after remission. Blocking parts of the chain reduced joint swelling. In people with the disease, a genetic variation linked to a weaker stress-hormone response also weakened the link between perceived stress and flare-ups. Human treatments are a long way off, but the work suggests a gentler target: intercept the stress-to-joint signal instead of suppressing the whole immune system.

SDG 3 · Good health and well-being — Mechanism: tech innovation