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New McKnight fellow tirelessly seeks to understand hibernation

By Deborah Wormser

A conversation with a fellow graduate student led to a life-changing revelation for Dr. William Israelsen, the 2015 recipient of UT Southwestern Medical Center’s Sara and Frank McKnight Fellowship for early independence.

“We were talking about ways we could gain a better understanding of the hyperactive metabolism of cancer cells, which divide very quickly. Hibernation came up as a counterexample,” he said, recalling the discussion at the Massachusetts Institute of Technology (MIT). “The more I looked into the regulation of metabolism during hibernation, the more I realized that none of the scientific questions I wanted to ask had been answered. At that point, I was hooked.”

Dr. William Israelsen
Dr. William Israelsen

The fellowship enables postdoctoral fellows to conduct independent research within the Department of Biochemistry. In 2001, donations from various sources helped establish the endowment in honor of the parents of Dr. Steven McKnight, Chairman of Biochemistry.

“I am very grateful and excited. This allows me to skip traditional postdoctoral training and immediately get to work in my new field of hibernation metabolism,” Dr. Israelsen said. “The Sara and Frank McKnight Fellowship has given me the support needed to get my research program started, and the freedom to take my science in what I think are the most exciting directions.”

Hibernating mammals employ extreme physiological states as a survival strategy: They accumulate prodigious amounts of body fat and subsist solely on those fat stores for up to six months. The molecular mechanisms of metabolic control during hibernation are poorly understood, he said, but lessons learned from hibernating animals might advance many areas of medicine beyond cancer.

“Transplantation science and some conditions in emergency medicine are a race against time due to unmet metabolic demand. Slowing down metabolism would buy more time before damage occurs. Hibernating animals have already figured out how to do this, and my goal is to understand how they are controlling the metabolic slowdown,” Dr. Israelsen said.

Using a special environmental chamber, he is able to study hibernation in the meadow jumping mouse, a rodent that can reduce its metabolic rate by 95 percent during hibernation.

Hibernating animals go from burning sugar (glucose) for energy to burning fat, a metabolic switch that is similar to that seen during starvation, he said.

“During hibernation, cell division throughout the body slows down or stops, but we don't understand what is causing this cell cycle arrest. In contrast, cancer is a disease of uncontrolled cell division. I am very interested to know why cells stop dividing during hibernation, and I really want to know what happens to a tumor during hibernation,” he said.

Dr. Israelsen grew up in North Logan, Utah. He graduated from Utah State University with degrees in biology and economics before earning his doctorate in biology from MIT.

In his downtime, he enjoys relaxing with his wife, Lora, and outdoor activities such as camping and working on the family cars.

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Dr. McKnight holds the Distinguished Chair in Basic Biomedical Research, and The Sam G. Winstead and F. Andrew Bell Distinguished Chair in Biochemistry.