Circadian clock may protect eyes from aging

A new study by the Purdue University’s College of Agriculture shows that if our circadian rhythm is disrupted, our eyes may be at greater risk of retinal degeneration as we age. The researchers studied fruit flies, which serve as a good model for the human retina, and how we could maybe prevent or slow down vision loss.

Vikki Weake, Associate Professor of Biochemistry at Purdue’s College of Agriculture, explains that the neurons involved in sensing light (photoreceptors) are delicate proteins that degrade during the day when they are exposed to light and rebuilt in the darkness. ‘’If the circadian clock is off and these proteins aren’t made at the right time, it’s a problem,” she argues.

Weake adds that “…regulating the time at which these proteins are made is important to protect the light-sensing neurons and retain vision.”

Clock and Cycle are two of the most important proteins regulating circadian rhythms. This study found out that the Clock:Cycle protein complex also regulates an important amount of the active genes involved in sensing light in the retina of Drosophila. According to the first author, Jauregui-Lozano, when the Clock:Cycle complex is disrupted, flies are susceptible to light-dependent retinal degeneration, and light-independent increase of oxidative stress. In other words, their study suggests that the circadian regulator Clock:Cycle acts as a neuroprotective factor in the aging eye by directing gene regulatory networks there.

Co-author Hana Hall, Research Assistant Professor of Biochemistry at Purdue, says that unlike most cells in the human body, neurons don’t divide and replicate, so their death leads to degenerative disease. Hall emphasizes that because of this, the cellular processes involved in repairing and regulating them are especially important, with aging being the main risk factor for neurodegenerative diseases. Her words give hope: “If we can understand the mechanics of how things get off track or become misregulated in our later years, we may be able to prevent or slow down the progression of these diseases”.


  • You can read more about the study here.
  • Original publication credits: Jauregui-Lozano J, Hall H, Stanhope SC, Bakhle K, Marlin MM, Weake VM (2022) The Clock:Cycle complex is a major transcriptional regulator of Drosophilaphotoreceptors that protects the eye from retinal degeneration and oxidative stress. PLoS Genet 18(1): e1010021.