The reduction in muscle mass and strength that occurs during ageing has a major impact on the quality of life of older individuals. Older people demonstrate loss of confidence in walking and reduced mobility which in turn leads to loss of independence and social isolation. These changes occur partly because we lose a large proportion of the muscle cells (called muscle fibres), but also the muscle cells that we retain are weak. It is currently unknown how muscle fibres are lost during ageing but there is considerable evidence that poor maternal nutrition leads to a number of changes in muscle of the offspring that result in reduced function. Muscle strength is also compromised in older individuals who did not grow well in early life, and studies suggest that maternal, developmental and nutritional factors are important.
microRNAs are small molecules that regulate gene expression resulting in different sets of proteins being present in the cells. Through this, microRNAs regulate cell functions. It is established that most biological processes, including muscle growth and wasting and ageing are, or are likely to be, regulated by microRNAs. The levels of microRNAs in muscle and other tissues change during ageing and upon changes in diet. As microRNAs can regulate the expression of many genes, and therefore physiological processes, they are likely candidates to regulate the effects of poor diet on muscle.
Researchers will study whether that a reduction in protein intake during foetal and early neonatal life results in modified microRNA-target interactions in muscles of the offspring, leadings to loss of muscle mass and function which has long term effects on the number of muscle fibres and ultimately adversely influences whether older individuals can maintain good muscle function as they age.
It is hoped that the outcomes of this study will lead to a greater understanding of the role that diet plays on the processes underlying the loss of muscle mass and musculoskeletal function in older individuals, which will lead to the development of interventions to correct these processes.
The project is a collaboration between Dr Aphrodite Vasilaki and Dr Kasia Whysall (University of Liverpool), Professor Avan Sayer (Newcastle University) and Professor Susan Ozanne (University of Cambridge).