Invited session "New discoveries in cellular cross-talk between skeletal muscle, its microvascular endothelium and vital organs underpin the importance of an active lifestyle" - MR 20.04.2016
Invited session "New discoveries in cellular cross-talk between skeletal muscle, its microvascular endothelium and vital organs underpin the importance of an active lifestyle" sheds the light on some of the recent breakthroughs in the research of active lifestyle and its benefits to the prevention of obesity and ageing related function loss and chronic diseases.
All three speakers approach the theme from fascinating perspectives focusing on the control exerted by trained skeletal muscles via the release of vascular endothelial growth factors, myokines and microvesicles with molecules communicating health messages to non-muscle cells, the circulation and vital organs. The session will be chaired by Prof. Anton Wagenmakers.
Professor Ylva Hellsten is group leader Cardiovascular Research in the Department of Nutrition, Exercise and Sport at the University of Copenhagen. Within her presentation
“Role of VEGF-A in Exercise Induced Capillary Growth and Nutrient Delivery to Skeletal Muscle”
Ylva will explain that one of the most important stimuli to increase the growth and density of capillaries in skeletal muscle is VEGF-A. VEGF-A is produced in skeletal muscle in the hours after exercise and is temporarily stored in cytosolic vesicles. Upon muscle contraction these vesicles translocate to the muscle membrane for release into the extracellular space. The VEGF-A molecules then travel to the endothelial cells of capillaries and arterioles in skeletal muscle and increase capillary growth. A high capillary density is important as it contributes to endurance performance (fitness) and maintenance of a high insulin sensitivity in skeletal muscle.
Professor Anton Wagenmakers is leader of the Exercise Metabolism and Adaptation Research Group at the Research Institute for Sport and Exercise Sciences (RISES) of Liverpool John Moores University. To better appreciate the benefits of an active lifestyle Anton will explain in the presentation
“Metabolic Consequences of Impaired Insulin and VEGF Signaling in Sedentary, Obese and Aged Individuals“
the metabolic and molecular mechanisms of the adoption of a sedentary lifestyle. The absence of exercise induced VEGF-pulses leads to a reduction in capillary density and fitness (exercise capacity). In addition meal-induced increases in plasma insulin concentration do not lead to the activation of eNOS and NO-dependent recruitment of muscle capillary surface area that is seen in physically active and trained individuals. This results in reduced uptake of meal-derived glucose and triglycerides in skeletal muscle, increased post meal blood glucose and triglyceride concentrations and preferential storage of these nutrients in adipose tissue, liver and the arterial wall (atherosclerosis). If at this stage no changes in lifestyle are made metabolic syndrome, sarcopenia and eventually type 2 diabetes and cardiovascular disease will follow and lead to premature ageing and mortality.
Mark Tarnopolsky is Professor of Pediatrics and Medicine and Director of the Neuromuscular and Neurometabolic Clinic at McMaster University Medical Centre. Within his presentation
Mark shows evidence that skeletal muscle during and following exercise in mice is releasing microparticles (30-110 nm, called exosomes) to the blood. Exosomes of endurance trained mice contain mRNA, miRNA, mitochondrial DNA (encoding for oxidative enzymes) and myokines known to have positive health effects such as IL-6, VEGF-A and VEGF-B. Transfusion of the blood from trained mice into sedentary mice led to the passive transfer of mitochondrial oxidative and exercise capacity, while transfusion of blood of trained mice into high-fat fed obese and insulin resistant mice led to a reduction in fat mass and an increase in insulin sensitivity. Collectively these exciting novel data suggest that exosomes may be able to transfer their content into extramuscular cells and tissues. As such exosomes are likely mediators of the well known beneficial effects of exercise training on health and function of the circulation and vital organs (e.g. liver, kidneys and brain).
See you at the invited session IS-PM10 New discoveries in cellular cross-talk between skeletal muscle, its microvascular endothelium and vital organs underpin the importance of an active lifestyle on 8th July 2016, Start: 09:45, Lecture room: 1.85 & 1.86