Researchers from the INCLIVA Health Research Institute, the Clinical Hospital of Valencia and the University of Valencia (UV) participated in a study, the results of which have just been published in Science, which paves the way for better understanding of muscle damage. . The work will allow, in the future, the application of interventions which accelerate its repair both in the physiological field, in the sports performance, and probably also in the clinical field, in the fragile or sarcopenic patient (loss of mass muscle and strength in older adults).
The main finding of this study is the discovery that muscle cells are able to regenerate quickly and autonomously and not only through the intervention of stem cells, as was believed until now. The objective of the work in which Mari Carmen GÃ³mez-Cabrera, professor of the Department of UV physiology and researcher of this project for INCLIVA, and researcher Esther GarcÃa participated was to clarify the mechanisms by which muscle fiber regenerates. after moderate damage such as that induced by physical exercise.
The mechanisms by which muscle is repaired in very severe muscle damage are well described and involve a type of cell called a muscle satellite cell. In less serious and much more common muscle injuries, such as those that occur after exercise and, possibly also, those associated with the process of muscle aging itself, the repair mechanism was not well established.
According to GÃ³mez-Cabrera, âUnlike what happens in other cells in our body, our muscles are made up of cells with multiple nuclei. The muscle cell is damaged when, for example, we suffer a trauma (a blow) but also when we exercise. Exercises with a large eccentric component (a type of contraction in which the muscle generates tension while increasing its length), such as going down stairs, can cause muscle damage. âIn addition, the professor at the University of Valence specifies: “muscle lesions are very frequent in athletes and repair mechanisms are very important in the fields of sports medicine, trauma and rehabilitation”.
The expert underlines the importance of this study, “which made it possible to observe that the repair mechanism of the non-severe muscular lesions does not involve, as was initially thought, muscle stem cells or satellite cells”.
What happens in a damaged fiber is that the cores of the fiber itself are attracted to the site of the damage, which speeds up their repair. “
Mari Carmen GÃ³mez-Cabrera, Professor, Department of Physiology, UV
The study is the result of a collaboration between the Pompeu Fabra University (UPF), the National Cardiovascular Research Center (CNIC) and CIBERNED, in Spain; and the JoÃ£o Lobo Antunes Institute of Molecular Medicine (iMM), Portugal.
Nuclei near the damaged area use the release of messenger RNA as a repair mechanism, which is translated into proteins, which act as building blocks to resolve muscle damage and restore fiber functionality.
Three types of experimental models were used in this work. They included athletes who performed an exercise protocol they knew to induce muscle damage, mice, and various cell models: muscle myotubes and myofibers. The repair mechanism they described is conserved in the three models studied and represents a very effective and relevant protective mechanism for minor muscle injuries.
In addition, the study was fundamental in the housing units, as well as the equipment acquired by INCLIVA thanks to ERDF funds resulting from the strategy of the Valencian Community for research on aging and fragility.
INCLIVA’s work for this study was developed with funding received from the Carlos III Health Institute CB16 / 10/00435 (CIBERFES), the Ministry of Science and Innovation (PID2019-110906RB-I00 / AEI /10.13039/501100011033); 109_RESIFIT, CSIC General Foundation; PROMETEO / 2019/097 from the Ministry of Health of the Government of Valencia and FEDER Funds.
MÂª Carmen GÃ³mez-Cabrera is coordinator of the research group on exercise, nutrition and healthy lifestyles and co-coordinator of the transversal program on aging and associated diseases at INCLIVA. She is also part of CIBERFES (Biomedical Research Center on Frailty and Healthy Aging). Undergraduate researcher Esther GarcÃa has also been involved in the work, through the design and development of in vivo studies with exercise, both in humans and in mice, over the past 18 months.
Romain, W., et al. (2021) Muscle repair after physiological damage relies on nuclear migration for cell reconstruction. Science. doi.org/10.1126/science.abe5620.