Study sheds light on how muscles try to fight effects of ageing

Researchers have shed new light on how muscles work to maintain function for as long as possible despite the effects of ageing.

The study may help explain why some muscle fibres age faster than others, and also identify the mechanisms the muscles employ to combat ageing.

The findings offer hope for future therapies and interventions to improve muscle health and quality of life as we age, researchers say.

Veronika Kedlian, first author of the study from the Wellcome Sanger Institute, said: “Our unbiased, multifaceted approach to studying muscle ageing, combining different types of sequencing, imaging and investigation reveals previously unknown cellular mechanisms of ageing and highlights areas for further study.”

Professor Hongbo Zhang, senior author of the study from Sun Yat-sen University, Guangzhou, China, said: “In China, the UK and other countries, we have ageing populations, but our understanding of the ageing process itself is limited.

“We now have a detailed view into how muscles strive to maintain function for as long as possible, despite the effects of ageing.”

Scientists from the Wellcome Sanger Institute and their collaborators at Sun Yat-sen University analysed muscle samples from 17 people aged 20 to 75.

By comparing the results they were able to compile a comprehensive atlas of ageing muscles in humans.

Published in Nature Ageing, the study uncovers new groups of cells that may explain why some muscle fibres age faster than others.

As people age, their muscles progressively weaken, and this can affect the ability to perform everyday activities like standing up and walking.

For some people, muscle loss worsens, leading to falls, immobility, a loss of autonomy and a condition called sarcopenia.

In the new study, scientists discovered that genes controlling ribosomes, tiny structures responsible for producing proteins, were less active in muscle stem cells from aged samples.

This impairs the cells’ ability to repair and regenerate muscle fibres as we age.

Further, they identified a process in which immune cells are attracted to the muscle and exacerbate age-related muscle deterioration.

The study also found age-related loss of a specific fast-twitch muscle fibre, key for explosive muscle performance.

However, researchers also discovered for the first time several compensatory mechanisms from the muscles appearing to make up for the loss.

Dr Sarah Teichmann, senior author of the study from the Wellcome Sanger Institute, and co-founder of the Human Cell Atlas, said: “With these new insights into healthy skeletal muscle ageing, researchers all over the world can now explore ways to combat inflammation, boost muscle regeneration, preserve nerve connectivity, and more.

“Discoveries from research like this have huge potential for developing therapeutic strategies that promote healthier ageing for future generations.”

This study was part of the international Human Cell Atlas initiative to map every cell type in the human body, to transform understanding of health and disease.