BACKGROUND:

In the UK, 10 million people are 65 years or older which will rise to 19 million by 2050. Ageing is characterised by immune system deterioration, inflammation and declining skeletal muscle mass and function. Even among older adults who are not obese, adipose tissue accumulates and becomes dysfunctional. This BBSRC-funded MIBTP project will establish whether adipose tissue inflammation and immune system deterioration exacerbates skeletal muscle ageing and whether regular exercise can reverse this process.

SUPPORTING RESEARCH:

We have shown that adipose tissue from older (66 ± 5 years) non-obese people contained double the number of inflammatory immune cells compared to younger (27 ± 4 years) non-obese people. When we measured the production of inflammatory molecules from adipose tissue, the levels were much higher among older compared to younger people. We have also shown by culturing muscle cells with serum from younger (27 ± 3 years) and older people (73 ± 1 years) that myotube diameter was much lower after treatment with serum from older people, which contained high levels of inflammatory molecules. The source of these systemic inflammatory molecules is unproven, but this project will establish the role and interconnectivity of two likely processes – immune system deterioration and adipose tissue dysfunction – in driving inflammation and skeletal muscle decline with ageing.

RESEARCH STUDY PLANS:

We will undertake two research studies. Due to the number and type of measurements we will make, each study will likely produce two peer reviewed scientific journal articles. The first study will be cross-sectional, whereby we recruit around twenty younger adults (e.g., 25-35 years) and around twenty older adults (e.g., 65-75 years). We will undertake measurements to characterise their immune system, their adipose tissue, and their skeletal muscle. The second study will be a randomised-controlled trial which we will design during the PhD. It might take the form of a three-month exercise training and dietary intervention study, and among the participants who take part, we will examine how their immune system, their adipose tissue, and their skeletal muscle changes due to the intervention.

ANALYTICAL METHODS:

You will develop skills that span exercise physiology and immunology. You will become competent at assessing cardiorespiratory fitness (indirect calorimetry), muscle function testing (resistance exercise), body composition assessment (Dual Energy X-ray Absorptiometry), physical activity assessment (accelerometery) and dietary assessment (diary and technology-supported approaches). You will develop skills in blood and tissue sample processing and cell culture techniques. You will develop skills in flow cytometry (i.e., assessing immune cells in blood, adipose tissue and skeletal muscle), immunohistochemistry (e.g., muscle myotube diameter), immunoblotting (e.g., protein synthesis measurements) and qPCR (i.e., expression of genes implicated in inflammation-adipose-muscle crosstalk).

ENVIRONMENT:

You will be based in the School of Sport, Exercise and Rehabilitation Sciences - an interdisciplinary world-leading School, ranked 5th in the Research Excellence Framework (REF-2021). PhD students have desks in open-plan offices close to academics and laboratory facilities, creating a vibrant atmosphere. Our modern facilities include a £16.4-million building with biochemistry, immunology, and human research laboratories and a £2-million exercise intervention space with facilities for blood and tissue sampling (e.g., 119-m2 group exercise space, 60-m2 for cardiorespiratory exercise, 150-m2 for muscle strengthening exercise).