Scientists engineer worms to live longer by absorbing sunlight

Scientists have genetically modified roundworms to make them capable of converting light into cell energy and extend their life, an advance that throws light on the mechanisms behind aging.

The study, published recently in the journal Nature Aging, genetically altered the cellular powerhouses mitochondria in the roundworm C elegans, enabling the organelles to convert light into chemical energy.

Researchers, including those from the University of Rochester in the US, found that by boosting metabolism using light-powered mitochondria, the laboratory worms had “longer, healthier lives”.

“These findings and new research tools will enable us to further study mitochondria and identify new ways to treat age-related diseases and age healthier,” study co-author Andrew Wojtovich said.

Mitochondria are the powerhouses present in most cells that use glucose to produce the compound adenosine triphosphate (ATP) – the energy currency used for key functions in cells.

ATP is produced in mitochondria following a cascade of chemical reactions that are made possible by the exchange of protons across a membrane separating compartments in these cellular powerhouses.

The efficiency with which this process happens in mitochondria is called membrane potential – a factor that is known to play a potential role in age-related diseases like neurodegenerative disorders.

In the new study, scientists genetically engineered C elegans mitochondria to include a light-activated proton pump obtained from a fungus.

When exposed to light, the proton pumps in the roundworm moved charged ions across the membrane, using the energy from the light to charge the mitochondria.

This process – dubbed mitochondria-ON (mtON) – boosted ATP production and membrane potential, resulting in a 30-40 percent increase in lifespan of the worms.

“What we have done is essentially hooked up a solar panel to the existing power plant infrastructure,” study co-author Brandon Berry said.

“In this instance, the solar panel is the optogenetic tool mtON. The normal mitochondrial machinery is then able to harness the light energy to provide the ATP in addition to the normal combustion pathway,” Dr Berry explained.

The study, researchers say, sheds more insight into the complex biological roles that mitochondria play in the human body and provides a potential new method to manipulate and study the organelle.

“Our findings provide direct causal evidence that rescuing the age-related decline in mitochondrial membrane potential is sufficient to slow the rate of aging and extend healthspan and lifespan,” scientists wrote in the study.