Molecular and technical evolution in bioscience has led to an explosion of methodologies to interrogate key questions surrounding human physiological regulation, including in exercise and health. For instance, advances in OMICS, stable isotope tracers, medical imaging, and myriad means to quantify intra/inter-cellular metabolic dynamics (e.g., mitochondrial function, vascular remodelling) offer an increasing number of analytical options. Pressing this agenda, UK Research and Innovation (UKRI) has schemes such as ALERT (BBSRC) to fund capital equipment of strategic basic science importance, while the MRC’s “better methods, better research” call is of a similar goal in a translational research space. As such, when planning research, considerations arise as to the most appropriate techniques and technologies to harness for best scientific effect. The areas of coverage within this presentation will focus upon aspects relating to: i) stable isotope tracers, ii) OMIC’s, and iii) study design/methodology relevant both to an exercise physiologist, but equally to the broader study of human health.
The first method/technique to be discussed is the recently developed Combined Oral Stable Isotope Assessment of Muscle (COSIAM). The aim of COSIAM was to develop a versatile and minimally invasive methodology to simultaneously quantify muscle mass (d3-creatine dilution), muscle protein synthesis (D2O direct incorporation) and muscle protein breakdown (d3-methyl-histidine dilution) via an orally consumed stable isotope tracer cocktail (1). In doing so, we demonstrate for instance, robust links between d3-creatine dilution and biomarkers of healthy muscle physiology. In future, COSIAM will prove a valuable tool in monitoring cross-sectional and longitudinal alterations at the core of muscle health in experimental medicine. Next, transcriptomics (2) and metabolomics (3) in human ageing/exercise responses will be briefly discussed as they pertain to discovery, while also highlighting limitations of single or limited time-point approaches. Reflecting these very limitations, the penultimate aim of this presentation will cover the concept of “dynOMICS”; currently recognised as fluxomics (of metabolites) and dynamic proteomics. Data will be presented to illustrate how stable isotope methods linked to OMICS may provide a conduit to the best of both worlds: big-data linked to dynamic cellular metabolism. To illustrate this methodology, we report on muscle cells in vitro being subject to dynamic proteomics over a time-course of 48h (murine C2C12) when treated with compounds to induce mitochondrial biogenesis (AICAR/GW501516) and also to inhibit protein synthesis (cycloheximide). Notably, of ~2000 proteins identified, 250 were accurately quantified across treatments, with treatments showing significant effects on rates of individual protein turnover e.g., cycloheximide showing an expected pattern for decline in many proteins. Finally, other challenges require briefly highlighting: 1) Which OMIC(S) should be applied and why? Multi-OMICS is progressive but not without complexities and associated high-costs, and what about external validation; 2) What sampling is possible, and will this generate sufficient material; 3) What issues surround study control e.g. feeding/physical activity; and 4) A dearth in skills of physiologically trained bioinformaticians; not least a shift toward a service industry.