Muscle cell nuclei migrate to sites of injury to deliver RNA to repair the muscle
Racing to repair our skeletal muscles after injury, satellite cells orbit our stretchy muscle cells, or myofibres, and fuse together to plug gaps. But here scientists reveal another, surprising source of help – the swift movement of the cells’ own nuclei. Daily damage from exercise triggers the myofibre’s multiple myonuclei (highlighted in blue here) to zip along the fibre (yellow and pink), alerted by chemical signals to the area of damage seen at the top left – a bit like the flashing lights on ambulances, only ~10,000 times smaller. At the scene, the myonuclei produce messenger RNA molecules which act as blueprints for proteins involved in cellular reconstruction, helping to rebuild and strengthen the muscle. The next step is to understand how this form of repair is affected by diseases like muscular dystrophy, and what scientists can do to help.
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