Source: Karolinska Institutet
Summary: A new study by researchers shows how an unexpectedly high number of mutations in the stem cells of muscles impair cell regeneration.
Muscular function declines with age. It has already been established that natural aging impairs the function of skeletal muscles. We also know that the number and the activity of the muscles’ stem cells decline with age. However, the reasons are not fully understood. In a new study, researchers from the Karolinska Institutet showed how an unexpectedly high number of mutations in the stem cells of muscles impair cell regeneration. A surprising part they observed is the high number of mutations, a healthy 70-year-old has accumulated more than 1,000 mutations in each stem cell in the muscle, and that these mutations are not random, but there are certain regions that are better protected. This discovery may result in new medication to build stronger muscles throughout aging. The study findings were published in the journal Nature Communications.
The mutations occur during natural cell division, and the regions that are protected are those that are important for the function or survival of the cells. Nonetheless, the research team was able to identify that this protection declines with age. The study was performed using single stem cells cultivated to provide sufficient DNA for whole genome sequencing. They achieved this in the skeletal muscle tissue, which is absolutely unique. They have also found that there is a very little overlap of mutations, despite the cells being located close to each other, representing an extremely complex mutational burden. The researchers will now continue their work to investigate whether physical exercise can affect the number of accumulated mutations. Is it true that physical exercise from a young age clears out cells with many mutations, or does it result in the generation of a higher number of such cells?
Prof. Maria Eriksson said, “We aim to discover whether it is possible to individually influence the burden of mutations. Our results may be beneficial for the development of exercise programmes, particularly those designed for an aging population.”
More Information: Irene Franco et al, “Somatic mutagenesis in satellite cells associates with human skeletal muscle aging”, Nature Communications (2018). DOI: 10.1038/s41467-018-03244-6