A group from Nanyang Technological University, having investigated the trend of muscle loss seen in certain chronic conditions, has identified the molecule myostatin as a possible drug target to tackle the problem.
There is always some cell turnover that occurs in our bodies; we have to destroy older cells to replace them with new ones. In the events of starvation, obesity, and diabetes, on the other hand, this process appears to skew heavily towards muscle cell destruction without concurrent cell regeneration. In other situations where patients are bedridden, such as those undergoing chemotherapy, muscle loss is a serious concern and can be lethal if it progresses to cachexia.
Where heavy muscle loss occurs, myostatin levels seem to be much higher than normal. This causes more myostatin to bind the muscle cells and trigger abnormally high rates of cell death, while new cells are not being made fast enough to compensate for this. Another effect is that myostatin keeps the muscles burning sugar, stopping the cells from utilising fat as a source of energy (therefore forcing it to be stored), while muscle tissue is simultaneously deteriorating.
Blocking myostatin should both reduce the amount of cell death that occurs, and encourage the body to burn fat, reducing the likelihood of obesity. From their studies, the group suggests that this mimics the effects of exercise (where myostatin levels have been observed to be low), and could be an alternative therapy for those patients that can’t undergo intense physical activity. Things aren’t so simple, however, since myostatin is essential for cell growth regulation in the body. In order to determine the feasibility of this as a drug target, the group is aiming to investigate the subsequent effects of myostatin inhibition over the lifespan of patients.
