Proteins change when skeletal muscle regenerates

lab animal Research highlights Muscle regeneration https://doi.org/10.1038/s41684-024-01407-1 Proteins change when skeletal muscle regenerates Check for updates Changes in protein expression have an important role in dynamic physiological processes, such as the regeneration of skeletal muscle following injury. A study in Scientific Reports using in vivo protein labeling shows a time-dependent protein signature in response to muscle injury, providing a better understanding of muscle regeneration and helping identify therapeutic targets. 8-week-old male mice were treated with cardiotoxin (CTX) to induce muscle injury and then euthanized at different time points for analysis of various muscle regeneration stages in comparison to uninjured animals. After 14 days, the injury was completely healed, and the muscle was histologically indistinguishable from the control group. Analysis of protein flux in skeletal muscle through mass spectrometry revealed that the protein synthesis rate during the proliferation stage, at 4 days post-injury (dpi), was globally unaffected compared to the control group. During the differentiation stage at 7 dpi and the maturation stage at 14 dpi, the team observed a global increase in protein synthesis in the injured group compared to the control, indicating a response to the injury. An analysis of functional clusters was performed to better understand which proteins were affected during the regeneration process. During the proliferation stage, only the myofibril cluster was representative. In both the differentiation and maturation stages, multiple clusters showed increased expression, pointing to an increased energetic demand in the injured group. When analyzing individual proteins with flux rate changes, the team identified 8, 14 and 91 individual proteins in the proliferation, differentiation and maturation stages, respectively. The maturation stage showed a higher protein turnover in proteins involved in energy and DNA replication processes. When checking global gene expression in the muscle, the team saw that more genes were up- and down-regulated in the proliferation and differentiation stages, compared with the maturation stage which showed around 90% of the gene expression being unaltered. Gene ontology showed an overall decrease in the groups protein assay; no correlation was identified between gene and protein expression changes. These results show that a paired omics approach is more effective at measuring changes during muscle regeneration than transcriptomics or proteomics alone. This approach could lead to advancements in understanding aging and muscle degeneration with more in vivo knowledge. Jorge Ferreira Original reference: Bizieff, A. et al Sci. Rep. 14, 13172 (2024) The best from Nature’s journalists and other publications worldwide. Always balanced, never oversimplifed, and crafted with the scientific community In mind. Sign up now go.nature.com/briefing A111250 Lab Animal | Volume 53 | July 2024 | 177 177  (...truncated)