The same chemical process that turns a baking cake golden brown is at work aging your body’s cells. Over decades, your tissues, baking steadily at 98.6 degrees, slowly accumulate compounds called advanced glycation end products, or AGEs, as sugars interact with protein and fat in the bloodstream. The buildup of AGEs is a hallmark of the aging process, making tissues like collagen sticky and rigid and causing inflammation that can lead to heart disease, eye damage, kidney disease and diabetes.
Researchers have tried unsuccessfully to develop medications that stop AGEs from forming. But a new study, published in Nature Communications, describes a different tack: Scientists created an enzyme that cleans one of the most common AGEs from human tissue, helping to turn back the clock even after the aging compounds have settled in the body. This cleanse can help repair the tissue and could allow cells to act younger.
“It’s a small step in this bigger direction, because aging is very complicated,” said Aaron Cravens, a founder and CEO of Revel Pharmaceuticals and the lead author of the study.
Many efforts to develop treatments for aspects of aging have focused on cells, which gradually lose the ability to repair themselves and divide properly. Less attention has been given to the aging of longer-lived tissue structures such as collagen.
Scientists have been aware of advanced glycation end products and their role in aging for decades. “It accumulates on tissue proteins like rust,” said John Baynes, a retired biochemist who was not involved in the study but who spent his career researching AGEs at the University of South Carolina Floyd School of Medicine. But researchers had no success creating drugs to inhibit the chemical reactions that produce AGEs.
The study by Cravens and his colleagues began with a hypothesis: Since all human tissue can be recycled into the biosphere after death, there must be a natural way to dissolve these compounds, even though they are extremely durable. To identify that process, they looked to the enzymes inside microbes, the agents of decomposition.
The team used AI to analyze the DNA sequences of 50,000 microbes and to compute the enzyme structures each genetic code would create. They then narrowed the results to several candidates that seemed capable of cleaving AGEs from human tissue. They eventually found one and engineered it to be more efficient. The novel enzyme, called CMLase, became very good at removing AGEs from human tissue samples. “In the most extreme case, we took 70-year-old human skin and brought the levels back to that of a 30-year-old,” Cravens said. — K. R. CALLAWAY
This article originally appeared in The New York Times.
