A team of researchers at the Buck Institute has uncovered the link between eye health, diet, circadian rhythm and longevity. Drosophila.
According to a report from the Buck Institute, it was published in a recent issue of the journal Nature.1
According to the news, previous research has shown in humans that there is a link between eye disorders and poor health.
“Our research says it’s more than a correlation: eye dysfunction can cause problems in other tissues,” said Dr. Pabjaj Kapahi, lead author of the study. “We are now showing that fasting improves eyesight, but that the eyes really play a role in affecting life expectancy.”
“It was amazing for us to find that the eye itself, at least in the fruit fly, can directly regulate life expectancy,” Dr. Brian Hodge, who did his postdoctoral studies in Kapah’s lab, said in a news release. .
According to Hodge, the main reason for the connection may be in the circadian “clocks”, the molecular machinery within each cell of each organism that has evolved to adapt to daily stresses, such as changes in light and temperature caused by rises and setting. of the sun. These 24-hour oscillations — circadian rhythms — result in complex animal behaviors, such as prey-to-prey interactions and sleep / wake cycles, to establish time regulation of molecular functions of gene transcription and protein translation.
According to the institute’s news, in 2016 Kapahi’s lab published a study. Cell Metabolism in a limited diet, fruit flies showed significant changes in circadian rhythms, in addition to prolonging life.
When Hodge joined the lab that year, he wanted to delve deeper into whether dietary changes changed processes that improve circadian functions and whether circadian processes were needed for the longer life seen with dietary restrictions.
“The fruit fly has such a short lifespan, and at the same time it’s a really beautiful model that allows us to screen a lot of things,” said Hodge, now a scientist at Fountain Therapeutics in South San Francisco.
The study began with an extensive survey to see what genes oscillate in a circadian way when flies in an unrestricted diet compare to those that feed only 10 percent of the unrestricted dietary protein.
Hodge quickly noticed a large number of genes that responded to the diet, and also showed fluctuations at different points in time, or “rhythmic.” He then found that the rhythmic genes most often activated by dietary restriction appeared to be from the eye, specifically from photoreceptors, from specialized light neurons in the retina of the eye that respond to light.
This finding led to a series of experiments in the story of how dietary restriction can extend life expectancy in order to understand how eye function is included. For example, they set up experiments that showed that keeping flies constantly in the dark extended their lifespan.
“It simply came to our notice then,” Hodge said in a statement. “We thought flies needed to have rhythmic or circadian lighting signals.”
They then used bioinformatics to ask: Do eye genes that are rhythmic and sensitive to dietary restriction affect their lifespan? The answer was yes.
“We always think that something is worth our eye, to give us sight,” Kapahi, also an associate professor of urology at UCSF, said in a news release.
Looking at the outside world, Kapahi said in a statement that the immune system is very active, which can lead to inflammation and, if left untreated, can lead to or aggravate many common chronic diseases. . In addition, light itself can cause degeneration of photoresists, which can lead to inflammation.
Kapahi also noted that long-time viewing of computer and telephone screens and being exposed to light pollution at night are a very worrying situation for circadian clocks.
“It confuses eye protection and this can have consequences beyond sight, damaging the rest of the body and brain,” he said in a statement.
There is much to understand about the role that the eye plays in the health and overall life of an organism, including: how does the eye regulate life expectancy, and does the same effect apply to other organisms?
One of the key questions that the work can apply to humans is whether mammalian photoresponders affect duration?
Hodge pointed out that it is probably not as much as in fruit flies, as a large portion of the energy of a fruit fly is directed to the eye. But since photoreceptors are just specialized neurons, he said, “I would argue that the strongest link is the role that circadian function plays in neurons, especially with dietary restrictions, and how they can be harnessed to maintain neuronal function during old age.”
When researchers understand how these processes work, they can start focusing on the molecular clock to slow down aging, Hodge said, and it may help humans maintain vision by activating the clocks in our eyes.
“It can be through diet, drugs, lifestyle changes … There’s a lot of really interesting research going on before,” he concluded.
Pabjaj Kapahi, PhD; Brian Hodge, PhD; et.al; Dietary restrictions and transcription factor clocks delay eye aging to prolong the life of Drosophila. Nature, published in June 2022. DOI: 10.1038 / s41467-022-30975-4