The aging process affects the entire body, but in the eyes it is an important risk factor for developing a group of neuropathies known as glaucoma, an age-related eye disease in which progressive neurodegeneration of the optic nerve occurs. , which if left untreated can lead to blindness, and which is estimated to affect more than 110 million people between the ages of 40 and 80 by 2040. A new study from the University of California at Irvine (UCI) in the United States , suggests that aging significantly influences the death of retinal ganglion cells in glaucoma and that repeated stress accelerates the aging of the eye.
The results of the study ‘Stress-induced aging in the mouse eye’ have been published in Aging Cell and may contribute to the design of new treatment options for glaucoma patients. Researchers have described the transcriptional and epigenetic changes that occur in retinal aging and have shown how stress situations, such as increased intraocular pressure (IOP) in the eye, cause epigenetic and transcriptional changes in retinal tissue. similar to those caused by natural ageing, and as in young retinal tissue, repeated stress leads to the appearance of characteristics of accelerated aging, including accelerated epigenetic age.
Prevention and early detection of age-related diseases
“Our work emphasizes the importance of early diagnosis and prevention, as well as targeted management of age-related diseases, including glaucoma,” said Dorota Skowronska-Krawczyk, an assistant professor in the Departments of Physiology and Biophysics and Ophthalmology and Professor at the Translational Vision Research Center of the UCI School of Medicine. “The epigenetic changes that we observed suggest that the changes in the chromatin level are acquired cumulatively, after several cases of stress. This gives us a window of opportunity to prevent vision loss, as long as the disease is recognized early.”
“We are testing different approaches to prevent the accelerated aging process that results from stress”
Intraocular pressure (IOP) in humans has a circadian rhythm that, in healthy people, is generally in the range of 12 to 21 mmHg and tends to be higher in about two-thirds of individuals at night. As a result of these fluctuations, a single IOP measurement is usually not sufficient to characterize the actual pathology and the risk of disease progression in glaucoma patients. Long-term IOP fluctuation is known to be a key predictor of glaucoma progression, and the new study suggests that the cumulative impact of IOP fluctuations is directly responsible for tissue aging.
The researchers were able to demonstrate that repetitive, mild elevation of IOP can accelerate the epigenetic age of retinal tissue through their collaboration with the Clock Foundation and Steve Horvath of Altos Labs, who pioneered the development of epigenetic clocks that measure the age as a function of the methylation changes in the DNA of the tissues, which allows estimating the effect of stress and treatment on the state of aging of the retinal tissue.
“Our work shows that even moderate elevation of hydrostatic IOP results in retinal ganglion cell loss and corresponding visual defects when performed in elderly animals,” explains Skowronska-Krawczyk. “We are continuing to work to understand the mechanism of cumulative changes in aging in order to find potential targets for therapy. We are also testing different approaches to prevent the accelerated aging process that results from stress.”
“In addition to measuring vision decline and some structural changes due to stress and potential treatment, we can now measure the epigenetic age of retinal tissue and use it to find the optimal strategy to prevent vision loss in aging.” concludes Skowronska-Krawczyk.
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