Vision Epigenetics: The New Fountain of Youth
Written by Avantika Gokulnatha
Edited by Chloe Chou
February 9th, 2023
Edited by Chloe Chou
February 9th, 2023
Research
Time is fleeting. In a society obsessed with youth, we have serums, treatments, creams, and lotions all with the goal of preventing external aging. But we are also faced with the darker toll that a long life poses: disease, chronic pain, and feebleness which prevent us from living life as we once did.
Groundbreaking research conducted at Harvard Medical School provides new insight into the biological basis of aging, and amazingly, how it can be reversed.
Neurons are the building blocks of the brain and nervous system. They intake external sensory inputs and relay electrical signals through the brain and body. As neurons age, they lose their capacity to regenerate and heal. In this project, the research team engineered a method to reprogram older neurons to regress to a younger state, one where they can regenerate after injury.
Researchers first infected the retinal ganglion cells of mice with a virus which triggers a molecular pathway that signals older cells to revert to a younger state. These cells are located in the eye and connect with neurons in the brain. While this has been found to be hazardous in previous studies, causing germ cell tumors that result in death, this study’s technique allowed for the reversal of the cells’ molecular clock without danger.
Next, researchers tested to see if this technique reversed damage on already-injured cells. After infecting crushed cells with the virus, researchers found that cell regeneration was triggered without any negative effects. This finding was consistent in both young and old cells, and led to successful healing of injured cells.
Researchers then questioned whether this technique could reverse other types of damage. They focused on glaucoma, a disease caused by the accumulation of damage to the optic nerve. Glaucoma causes vision loss and is the most common cause of human blindness. Researchers found that their technique fully restored vision in older mice with glaucoma.
How then does the research team’s technique of using a virus to trigger a molecular pathway actually work? To understand this, we must understand how aging is encoded on a molecular level. A current hypothesis is that cells accumulate molecular changes that modify their gene expression patterns. As these changes accrue over time, the cell loses the correct patterns it had in its youth. One clear marker of these “aging” changes is DNA methylation, which involves the addition of methyl groups to the DNA and serves to enhance or repress gene expression.
When considering this concept of molecular aging in their study, researchers found that damaging the retinal ganglion cells accelerated DNA methylation. This in turn changes the pattern of gene expression of cells in a way that resembles cellular aging. Their virus treatment reversed the methylation by inducing the expression of enzymes that remove DNA methylation.
As the findings of this study show, the secret to eternal life may not be as fictitious as once thought. We may soon be upon an age of external and internal anti-aging frenzy; time can only tell.