Lower cardiolipin in mouse muscle lined up with a fast-to-slow fiber shift; partial restoration reversed wasting in that model

What the research found

Study (mice, plus human muscle samples that confirm a decline). Fabian Finger, Zach Gerhart-Hines, and colleagues at the University of Copenhagen report in Nature Aging (university news 29 September 2026) that cardiolipin, a fat almost exclusive to the inner mitochondrial membrane, falls in mouse and human muscle mitochondria with age and disease. Lowering cardiolipin in young mice reproduced the fast-to-slow fiber shift seen in aged mice and people. Restoring cardiolipin to about two-thirds of normal began to reverse wasting in that model and prevented the animals’ early deaths. Reactive oxygen species helped carry the signal: mopping them up with N-acetylcysteine blunted the fiber shift and, in these engineered mice, made wasting worse. Blocking the receptor ERRγ in cultured cells stopped the fiber switch. Human samples were used to confirm the cardiolipin drop, not to test a remedy. A cardiolipin-directed treatment has accelerated approval for Barth syndrome, a rare genetic condition, which is a different use. Educational notes. This is not advice to take an antioxidant pill.

Evidence level: Animal study. Results in animals or cells often don't carry over to people.

Read the original at University of Copenhagen / Nature Aging