Muscle resilience across the life course: from cells to society

The number of people living into old age is increasing rapidly throughout the world, however although people live longer, they are not healthier. Adults in the UK now spend the last decade of life in poor health, placing a large burden on health and social care services. One of the big changes in our bodies as we age is the loss of muscle tissue, with up to 50% of muscle mass being lost by 80 years of age. Muscle is an important tissue in our body, as it is vital for movement, posture and the way in which food is used as energy. The loss of muscle during ageing makes it harder to carry out day-to-day activities, increases frailty and the risk of falls and injuries, and increases the risk of conditions like heart disease, diabetes and dementia. Muscle loss is the single largest reason for losing independence in old age, so it is important to keep our muscles healthy (resilient) as we grow older, by eating well and leading an active lifestyle.
When muscles age, several things happen: muscle fibres become smaller and fewer in number, the muscle contains more fat and fibrous tissue, and the ability of muscle tissue to repair and renew itself decreases. Not everyone ages in the same way - in fact there is a great deal of variation when we look at large numbers of older people. Some of the differences between people can be explained by the genes an individual inherits. Much of the remaining variation is due to a person's life circumstances. Factors like how much exercise we take, the food we eat, our educational background and whether we live comfortably or in poverty all play a major role. Although scientists around the world have worked hard to understand the causes of muscle ageing, it is such a complex problem that we need to find new ways to tackle it. In the past, researchers have tended to focus on one part of the problem, in an area where they are expert. We plan to take a new approach that shifts away from studying single systems on their own and move towards a combined effort where we study muscle ageing across all scales from the microscopic level to the scale of populations. We will also join forces with researchers from other disciplines like mathematics, artificial intelligence, social sciences and geography to find new approaches to solving the big questions in muscle ageing. The aim of this network is to bring together researchers, businesses and the people and organisations that benefit from research, from many areas, offering new insights into muscle health and an understanding of the pathways leading to muscle ageing.

Specifically we will:

Develop a national network of researchers across a wide range of disciplines to focused on muscle resilience and ageing throughout life and across scales.
Increase the understanding of the mechanisms influencing muscle ageing and the variability between individuals.
Provide secondments and training for early career scientists and technical staff.
Work with policy makers, health care practitioners, industry and patient groups to translate our insights into improved health benefits, developing new preventative and treatment strategies

The outcomes of our network activities will be wide ranging, spanning from new scientific insights, the application of new technologies, interdisciplinary grant proposals, to training and exchange of knowledge across disciplines, to helping make policy at the national level, with the unified aim of relieving the major societal problems connected to muscle ageing and loss of mobility.

A prominent change associated with ageing is the loss of muscle mass and function. As muscle is critical for physical function and metabolic homeostasis, loss of muscle mass and function results in adverse outcomes and is the major cause of loss of independence in old age. Muscle ageing is characterised by a variety of molecular, physiological, and systemic changes, often overlapping and interdependent. Ageing related changes in muscle are not linear or consistent and there is considerable variation across aged populations. Some of the variability can be explained by fixed genetic factors, but much of the variation is due to an individual's physical and social environment, with factors such as physical activity, nutrition, and socio-economic background all playing a role.

Although research has focused on understanding the determinants of muscle ageing, the complexity of the process requires a new, convergent approach. We need to move away from systems in isolation towards a holistic understanding of muscle ageing where molecular, physiological, organism and population level research is combined. The MyAge network will break down the silos associated with reductionist research, bringing together non-overlapping expertise, researchers, industrialists, and stakeholders, from musculoskeletal research, metabolism, regenerative medicine, 'omics, epigenetics, maths, data and social sciences, health inequity, biotech, and pharma, to understand the mechanistic pathways of muscle development, differentiation and decline.

The MyAge network will:

Create a national, interdisciplinary network in muscle resilience with international links identifying big questions and developing novel hypotheses
Through secondments deliver training opportunities for next generation researchers and technicians.
Develop a roadmap for muscle ageing research to inform policy development, targeting proactive steps to address muscle ageing and related health inequities and inequalities.