Mending Muscles

Your blood contains cell fragments – platelets – that can supercharge muscle repair. It's why platelet-rich plasma injections are used to treat muscle injuries. Researchers investigate why this works using fluorescence microscopy of uninjured and injured mouse muscles (pictured). Platelets accumulated after injury and antibody treatment to deplete injured muscles of platelets prevented immune cells called neutrophils from accumulating in these muscles. This also impaired repair. As platelets release chemical messengers called cytokines, researchers measured cytokine levels after injury in normal and platelet-depleted muscles. Platelet depletion reduced levels of the neutrophil-attracting cytokines CXCL5 and CXCL7. Comparing muscles from normal mice (before injury, left; 2 weeks later, middle) and those lacking CXCL7 (2 weeks after injury, right), revealed mice lacking CXCL7 recruited fewer neutrophils upon injury and 2 weeks later had smaller muscle fibres (zoom, bottom right). Platelet-derived CXCL7 therefore promotes muscle repair via neutrophils – this pathway could be exploited to boost repair.

Written by Lux Fatimathas

Lux Fatimathas

Writer

Having pursued science through a career in research, communications and publishing, she is currently a writer and editor for a healthcare marketing agency and also juggles freelance science writing.

• Image adapted from work by Flavia A. Graca and colleagues
• Department of Developmental Neurobiology, St. Jude Children’s Research Hospital, Memphis, TN, USA
• Image originally published with a Creative Commons Attribution 4.0 International (CC BY 4.0)
• Published in Nature Communications, March 2023