The first map of human muscles shows that our body does not want to age
Kyiv • UNN
Scientists have created the first-ever atlas of human muscle aging, identifying new cell populations that explain why some muscle fibers age faster than others and revealing cellular mechanisms that help resist muscle loss.
Scientists from the Velcom Sanger Institute and Sun Yat-sen University have discovered new cell populations that may improve understanding of why some muscle fibers age faster than others. This is reported by Interesting Engineering, UNN reports.
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Researchers have created the first-ever atlas of aging human muscles, which will help scientists around the world develop new methods to combat sarcopenia, the age-related loss of muscle mass and strength. The study identified new cell populations that explain why some muscle fibers age faster than others. In addition, the scientists' approach to the study of muscle aging, combining different types of sequencing, has revealed previously unknown cellular mechanisms to fight aging.
By analyzing individual cells and nuclei, as well as using advanced imaging, scientists were able to study human skeletal muscle samples in detail. Skeletal muscles attached to bones perform many functions: they provide movement, maintain posture, regulate body temperature, store nutrients, and help express emotions on the face. One of the diseases affecting skeletal muscles is sarcopenia. This is an age-related decrease in muscle mass and strength. Sarcopenia has many causes and affects more than 20% of older people. So far, there are no approved drugs to treat this disease.
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During the study, the team took samples from 17 people aged 20 to 75. The scientists then compared the results and identified numerous processes underlying age-related muscle changes.
It turned out that the genes controlling ribosomes were less active in muscle stem cells from samples of elderly people. Ribosomes are "factories" for protein production in the cell. Their low activity reduces the ability of cells to repair and regenerate. In addition, the population of non-muscle cells in the samples contained an increased amount of the molecule CCL2, which promotes inflammation. CCL2 attracts immune cells to the muscles, which leads to further age-related muscle damage.
Scientists have also obtained encouraging results. For the first time, they discovered compensatory mechanisms in the muscles that seem to help withstand muscle loss.
For example, the scientists observed enhanced regeneration of the surviving muscle fiber subtypes. In addition, they identified a specialized population of nuclei inside muscle fibers. These nuclei contribute to the restoration of neuromuscular connections weakened with age. Experiments on laboratory-grown human muscle cells confirmed the role of these nuclei in maintaining muscle function.
The study was led by Professor Hongbo Zhang, who notes that population aging is a serious problem in many countries.
Our knowledge of the aging process itself is limited. Now we have a detailed understanding of how muscles try to maintain their functions for as long as possible, despite age-related changes
Thanks to the Human Cell Atlas, scientists are gaining more and more information about the early stages of human development. This data, including information on healthy aging of skeletal muscle, can help researchers around the world find new methods to combat inflammation and other problems associated with aging.
