How can health care target healthy aging? Skeletal muscle may hold the key

Years ago, increasing a person’s lifespan (amount of time between birth and death) was medicine’s greatest challenge. After decades of discovery, this feat has been accomplished and medical research’s newest pursuit has commenced: increasing healthspan (the number of healthy, functional years in a person’s life). Thanks to the dedication of researchers like rehabilitation sciences doctoral candidate Davis Englund, we may discover effective strategies to increase healthspan in our rapidly aging population. 

“I always had a strong interest in science, but it wasn’t really until college that I began looking for different research opportunities,” Englund said. “When I was an undergrad, one of my first research experiences was in a lab at Northeastern University studying sarcopenia (the loss of muscle mass and function with advancing age).”

Once understudied and underappreciated, the regulation of skeletal muscle mass became a gripping subject for Englund. “I became really interested in the basic biology that was leading to the loss of muscle mass in older adults” he said. “In particular, I honed in on skeletal muscle stem cells, called satellite cells, which reduce substantially in number and activity with aging. This interest led me to reach out to my now doctoral advisor, Dr. Charlotte Peterson, a world leader in satellite cell and skeletal muscle biology.”

After coming to UK for his PhD, Englund continued his deep dive into research. “For me, the most provocative aspect of research has always been the potential to create new information that can push biomedical research forward and potentially improve human health and wellbeing,” he added. “Intellectually, this can be very challenging but at the same time an incredibly rewarding process.”

Recently, Englund has been working on clarifying the role satellite cells play in muscle maintenance and adaptability with advancing age.

“Previously our lab completed a study which showed that the depletion of satellite cells throughout adulthood didn’t influence the rate or onset of skeletal muscle loss with aging,” Englund explained. “The findings from this study are restricted to sedentary mice, so I designed a subsequent study giving mice with and without satellite cells free access to running wheels to determine if our previous findings could be extended to a physically active cohort of mice. Interestingly, we found that satellite cells are required for increases in muscle size in response to lifelong physical activity, suggesting there may be therapeutic potential in targeting this stem cell population as we age.”

What does this mean for the generations of adults at risk for developing sarcopenia? “The overarching idea is that if we can gain an in depth understanding for the cellular processes regulating skeletal muscle mass we can then leverage this information into targeting specific cell types or signaling pathways in order to preserve or restore muscle mass in at-risk populations,” Englund said.

Sarcopenia and frailty due to aging are coming more and more to the attention of the scientific community as baby boomers and other generations begin to feel the effects of age on their bodies.

“Sarcopenia was just recently characterized as a disease, which is a step forward,” Englund said. “Now, that sarcopenia has reached the disease classification, there should be more room to grow. The important steps now are creating strict and widely accepted diagnostic criteria that can be utilized by physicians and help guide the design of future clinical trials – further there are currently no efficacious pharmacological or cell-based treatment strategies, creating a necessity for further research in order to develop effective therapies aimed at the prevention or treatment of sarcopenia.”

The importance of healthspan isn’t lost on Englund. “We know skeletal muscle mass plays a critical role in preserving functional independence during aging,” he said. “Not only does this maintain an individual’s quality of life, remaining functionally independent leads to substantially lower rates of health care utilization, reducing excess costs to the health care system.”