Buck Institute researchers have discovered a relationship between food, circadian rhythms, eye health, and longevity in Drosophila for the first time.
They also discovered, surprise, that activities in the fly eye are really driving the aging process, which they published in the June 7, 2022 edition of Nature Communications.
Previous research on people has shown a link between eye diseases and bad health.
“Our work indicates that it is more than just a correlation: malfunction of the eye may really cause problems in other tissues,” said senior author and Buck Institute Professor Pankaj Kapahi, Ph.D., whose lab has long established that fasting and calorie restriction can enhance numerous physiological processes.
“We are now demonstrating that fasting not only improves vision but that the eye also influences longevity.”
“We were surprised to discover that the eye itself, at least in the fruit fly, may directly govern longevity,” said lead author Brian Hodge, Ph.D., who performed his postdoctoral research in Kapahi’s lab.
According to Hodge, the reason for this relationship rests in circadian “clocks,” the molecular machinery inside every cell of every creature that has evolved to adapt to daily pressures such as variations in light and temperature induced by the rising and setting of the sun. Which is one reason why people purchase special eyeglasses from sites like https://www.optical-center.co.uk/eyeglasses
Circadian rhythms, or 24-hour oscillations, influence complex animal behaviors such as predator-prey interactions and sleep/wake cycles, as well as the temporal control of biological operations such as gene transcription and protein translation.
Kapahi’s team conducted research in Cell Metabolism in 2016 that showed that fruit flies on a limited diet had substantial modifications in their circadian rhythms as well as a longer lifetime.
When Hodge joined the lab later that year, he wanted to go further to see whether mechanisms that increase circadian functioning were impacted by the diet modification, as well as whether circadian processes were necessary for the extended lifespan found with dietary restriction.
“Because the fruit fly has such a short lifetime, it’s a very lovely model that enables us to test a lot of things at once,” said Hodge, a scientist at Fountain Therapeutics in South San Francisco.
The research started with a comprehensive survey to identify whether genes fluctuate in a circadian pattern when unrestricted diet flies were compared to those given just 10% of the protein of the unrestricted diet.
Hodge immediately observed a number of genes that were both diet-responsive and exhibited ups and downs at various time intervals, or were “rhythmic.”
He subsequently observed that the rhythmic genes that were most triggered by dietary restriction seemed to be originating from the eye, especially photoreceptors, which are specialized neurons in the retina of the eye that react to light.