Protective response to starvation may promote heart failure

A protective response to starvation may promote heart failure, according to a study just published in Cell Metabolism. Two proteins that team up to conserve energy when food is scarce also limit energy production in the heart—a situation that can prove fatal when the heart is stressed and in need of an energy boost.

During starvation, the body conserves energy by slowing down the cell's powerhouse organelles, the mitochondria. This slackens the function of the vital organs, including the heart, thus preserving available energy and prolonging survival. Junichi Sadoshima, MD, PhD, and colleagues at the University of Medicine and Dentistry of New Jersey (UMDNJ)-New Jersey Medical School have discovered that two proteins, called PPAR-alpha and Sirt1, are induced by starvation in mice and turn off the expression of genes involved in mitochondrial function and heart contraction.

When the heart is stressed, it requires extra energy to maintain heart beat and blood pressure. Unfortunately, however, expression of PPAR-alpha and Sirt1 was also increased in stressed hearts, thus restricting energy just when the heart needs it most. If the same holds true in humans, it may be beneficial to target these proteins in patients with heart failure.