Hua Bai, an assistant professor of genetics, development and cell biology at Iowa State University, led a study, published recently in the academic journal Autophagy, that explores the genetic mechanism that causes fly cardiac muscles to deteriorate with age. Bai said the research team restored much of the cardiac function in middle-aged flies, which experience many of the same heart maladies as middle-aged humans.

The researchers’ approach starts with autophagy, a cellular “cleanup process” that removes and recycles damaged proteins and organelles. The autophagy process slows with age, which can lead to the weakening of cardiac muscles. Bai’s research team looked at a key genetic pathway conserved in virtually all organisms on Earth related to autophagy that balances organism growth with nutrient intake. This pathway, called mechanistic target of rapamycin (or mTOR), has long been linked to tissue aging, Bai said. One of two complexes that underlie the mTOR pathway, referred to as mTORC2, decreases with age as autophagy declines. But the researchers found that transgenically boosting mTORC2 strengthens heart muscles of older fruit flies.

“Boosting the complex almost fully restored heart function,” Bai said.