A protein that dulls insulin's signal — and exercise switches it down

For people with type 2 diabetes, the central puzzle is why muscle stops listening to insulin, the hormone that tells it to soak up sugar from the blood. A study published today in Nature Communications points to a protein called Miro1, which sits on mitochondria — the tiny power plants inside cells — and piles up in the muscle of people with the condition. In laboratory models, removing Miro1 restored the muscle's response to insulin. And in a trial with people who have obesity and type 2 diabetes, aerobic exercise lowered Miro1 levels while improving insulin sensitivity — a clue to why exercise itself works so well. The work, led by Dr John P. Kirwan's team from Pennington Biomedical Research Center and the University of Oklahoma, does not yet offer a treatment, but it gives drug makers a concrete new target: calm Miro1 down, and muscle may start hearing insulin again.

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