Cellular fuel gauge could hold clue to diabetes

A molecule in the body could hold the key to explaining why people who exercise regularly are less likely to have illnesses such as type 2 diabetes. The enzyme, called AMPK, acts as the body’s ‘fuel gauge,’ playing a crucial role in regulating energy intake, utilisation and storage. Finding out exactly how it works could help to explain how exercise affects the body at the molecular level.

In a review article published in the journal Cell Metabolism, Professor David Carling and colleagues at the Medical Research Council Clinical Sciences Centre at Imperial College London based at Hammersmith Hospital, describe current research on AMPK. Research on this molecule will increase our understanding of the effect that exercise has on metabolic activity in the cells of the body, and could explain the link between regular exercise and onset of type 2 diabetes.

“The benefits of exercise as a weight-loss tool are very well known, but exercise also has other medical benefits,” comments Professor Carling. “Illnesses such as diabetes and heart disease have all been shown to be less prevalent in people who do moderate amounts of exercise, and it is looking likely that AMPK plays a key role.”

Found throughout the body, AMP-activated protein kinase (AMPK) is one of the gatekeepers in the process of energy production and expenditure in the cell. Higher levels of AMPK in muscle tissue increase energy expenditure and glucose uptake, a process which goes wrong in diabetes. AMPK in the brain has a different effect - in laboratory studies lowering AMPK levels in the brain leads to a decrease in appetite and food intake.

Professor Carling’s group has been awarded a £335,000 EU grant in order to continue their research on the cellular actions of AMPK. The project brings together 25 other groups from 13 countries, and involves a number of different approaches, including genetic studies in humans. “By being able to piece together the complex pieces in the molecular jigsaw, we can better understand how our metabolism functions in health and disease,” adds Professor Carling. “We expect the results to have important implications for diets and lifestyles of the future. Exercise will of course continue to be a cornerstone of healthy living, but it is likely that we will be able to design drugs that interact with AMPK as an alternative when exercise is not possible or when dietary interventions have failed”.