A fist-sized clam found off the coast of Maine is known to live 500 years or longer, while the longest-lived human have not lived much more than 120 years. So, what does the ocean quahog knows about healthy aging which is not known to humans? Such questions drives Steven Austad, Ph.D., chair of the Department of Biology in the UAB College of Arts and Sciences and associate director of the UAB Comprehensive Center for Healthy Aging, to research in the area to unravel the mystery of healthy aging.
The aim of Austad’s studies in comparative gerontology, which look to long-lived animals, is to identify new molecular targets to help humans. His research focuses on understanding the underlying causes of aging at the molecular level.
A part of his research includes the work on a book called Methuselah’s Zoo, which Austad describes as “a natural history of successful aging.” This book is going to have the profiles of long living creatures like 500-year-old clams, 200-year-old whales and 40-year-old bats.
More than a dozen species of clams have lifespan of 100 years of more. They are technically bivalve mollusks and are known to live longer than any other animal groups. However, not all clams live to such an age. For this study, Austad’s lab is studying mitochondrial function, protein stability and stress resistance across seven species of clams, the lifespans of which ranges from a year to the ocean quahog’s 500-plus years.
Austad work led him to find one of the key causes of slow aging, which is to protect the protein inside our cells. Proteins have to be folded precisely to make everything inside the cell work well. But, as we age, they get battered and eventually lose their precise shape. Austad found that ocean quahogs keep their proteins in shape century after century. To experiment further, Austad took human proteins and added them to a mix of tissues from the clams and found that they became more stable and hence, less likely to unfold.
Austad lab is now working to find out exactly what protects the clams’ proteins, which they feel could point to a potential treatment for aging. It could also open avenues for new therapies for conditions caused by protein misfolding like Alzheimer’s disease, etc.
Austad is also studying a tiny freshwater creature called a hydra, which does not age typically. But, recently it was found that one particular species of hydra that begins to age rapidly under the certain combination of environmental conditions. His lab is now working to discover the molecular mechanisms that get switched on, or off, as the hydra’s environment changes. Austad is hopeful that such study will help them to identify new genes that might be targets for new drugs to keep people healthy longer.
Austad, scientific director for the American Federation for Aging Research opined that today we know a lot of things from animal work that will slow aging by 20 percent. That is incredible as there is a huge difference between being healthy for 60 years and being healthy for over 70 years. By treating the underlying causes of aging, we can push back cancer, heart disease, blindness, hearing loss and other such diseases associated with aging and make life healthier.
Another interesting lead, being followed by Austad is the drug rapamycin; a number of studies, from yeast, worms and mice, have shown that rapamycin can extend lifespan as well. Rapamycin is a FDA-approved drug to prevent rejection after organ transplants. In mice, it prevents cancer, heart disease, Alzheimer’sa whole host of things. Even though these findings are exciting, there is a need to exercise caution too. For example, rapamycin has several side effects in mouse studies, like an elevated incidence of cataracts, loss of glucose sensitivity and testicular atrophy. More studies and research is needed to find out the right dosing and formulation that can overcome these issues in humans.