Professor Aims to Understand and Fight Leading Cause of Death in Older Women

April 16, 2009

Heart disease is the leading cause of death in women over the age of 75. Researchers believe that the reason for this is that, after menopause, women lose their ability to produce the hormone estrogen, and low estrogen levels somehow make women more vulnerable to heart disease and heart attack. However, the exact reason for this has not been pinpointed.

Donna Korzick, associate professor of physiology and kinesiology in Penn State’s College of Health and Human Development, has undertaken a large-scale project using a $1.8 million grant from the National Heart, Lung and Blood Institute, to figure out why estrogen deficiency puts women in danger for heart disease.

The bulk of Korzick’s research will consist of identifying proteins in heart cells that might be affected by both aging and low estrogen levels. She will be working in conjunction with Bruce Stanley, director of scientific programs at Penn State Milton S. Hershey Medical Center, to identify these proteins.

“Proteins are the work horses of the cells,” says Korzick. “When they become activated, they can trigger different functions within the cell; some are even responsible for cell death as we age.” Proteins can become ‘activated’ in a variety of ways, including by low estrogen levels.

Specifically, Korzick will be analyzing the proteins within one compartment of the heart cells, the mitochondria. These are the “gate keepers of cell survival,” says Korzick. The mitochondria play a very significant role in whether or not a cell lives or dies as we age, especially while experiencing a heart attack.

“Cell death is a natural process,” explains Korzick “But when heart cells die, it means that the remaining cells have to do more work. In this way, cell death is directly linked to how well the heart can withstand a stress like a heart attack.”

After identifying the heart cell’s proteins, Korzick will determine which proteins respond to low-estrogen environments. Korzick can then use protein-targeting drugs that can activate or inhibit specific proteins in the heart cells. This will change what is happening inside the cells, and Korzick hopes that these experimental results will provide the missing piece to the estrogen deficiency–heart disease puzzle.

Korzick will be looking primarily at rats, because their short life span—only two years—allows for a “true model of aging,” according to Korzick. In addition, other researchers have completed a lot of work involving aged rats, so Korzick will have a comprehensive knowledge base to work with.

“At the very least, we’ll be learning about heart disease in older females,” says Korzick. “Right now, most of the estrogen-specific research is based on males, or young rats. Our research focuses on females, both young and old.”

Already, Korzick has identified nearly 600 proteins within the mitochondria of a rat heart cell. She has done so with the assistance of Tim Lancaster, who received his master’s degree in Kinesiology in 2008. Her research, which received funding in March 2009, is funded for five years.

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Editors: Donna Korzick can be contacted at dhk102@psu.edu or 814-865-5679. For additional information, please contact the College of Health and Human Development Office of College Relations at 814-865-3831 or healthhd@psu.edu.