Researcher focuses on how the immune system heals the heart

Dr. Justin Deniset, PhD, recently joined the Libin Cardiovascular Institute. His work focuses on how the immune system contributes to normal heart function and how it modulates the healing response in the heart following infection or injury, such as a heart attack.

According to Deniset, an assistant professor in the departments of Physiology and Pharmacology and Cardiac Sciences at the Cumming School of Medicine, it’s an important area of research, because more people are developing heart failure, due to an increased rate of survival of heart attacks and other heart conditions.

It’s estimated that about 600,000 Canadians are living with heart failure, a serious condition that erodes quality of life due to symptoms like shortness of breath, swelling, fatigue and weakness and a rapid or irregular heartbeat.

“People who survive heart attacks often go into heart failure, partly due to scarring in the heart," says Deniset. “My research is looking at how the immune system dictates how the heart heals or scars and examines the possibilities of altering the immune system to delay heart failure.”

Deniset has experience in this area. His postdoctoral studies, under the mentorship of Dr. Paul Kubes, PhD, included a novel discovery. Working in collaboration with Dr. Paul Fedak, MD, the research team found healing properties in the pericardial fluid surrounding the heart and linked them to previously unknown immune system cells that were shown, in experimental models, to help the heart heal after injury.

The discovery was published in the prestigious journal, Immunity, and cardiac surgeons now know that there could be a benefit in preserving the pericardial fluid rather than simply discarding it following cardiac surgery.

Deniset is continuing his work in this area, trying to understand exactly how these cells work to heal the heart tissue.

He is also working on a project looking at how biomaterials, cellular matrixes which have been found to promote healing in the heart, can be used to enhance outcomes for cardiovascular patients. Libin researchers have learned that the biomaterials, which have been used after heart surgery, attract immune cells which cause the heart to scar less and maintain more function.

Deniset is looking at the mechanisms behind how the biomaterials work.

“We have broad ideas of how the biomaterials are benefitting patients, but we want to understand how the immune system contributes to this response,” says Deniset. “If we understand the mechanisms, we can better tailor these biomaterials for treatment.”

The lab studies the immune system in a unique way thanks to an imaging technique, developed by Deniset, that uses special imaging equipment to view the immune system in action.

Deniset says he is excited about the opportunities within the Institute. By working with other researchers and clinicians, he can advance his research by accessing clinical samples and data.

“The Institute offers a lot of possibilities for collaboration, there are many promising things coming from that.”

Deniset is a member of the Dept. of Physiology and Pharmacology and the Dept. of Cardiac Sciences at the University of Calgary’s Cumming School of Medicine.