UA Heart Surgeon Dr. Zain Khalpey Receives Grant to Understand Healing Power of Stem Cells

Zain Khalpey, MD, PhD, MRCS(Eng), associate professor, University of Arizona Division of Cardiothoracic Surgery, and the Tony Marnell Sr. Distinguished Chair in Cardiothoracic Surgery, recently was awarded $25,000 from the Fineberg Foundation in Los Angeles to support his research toward understanding the mechanisms of how stem cell therapy works and how to maximize its potential for repairing damaged hearts.

Myocardial infarction (MI), commonly known as heart attack, typically occurs when the blood supply to parts of the heart is cut off by a blocked artery. This causes damage to the heart tissue, and the cells in the affected area start to die. In the days and weeks following a cardiac incident, this damaged area may grow, eventually leaving a large part of the heart unable to function properly and increasing the risk of further heart problems.

Currently, stem cell injections are being used as a treatment option for patients who have suffered a MI. Stem cells are harvested from a patient’s bone marrow and then undergo a laboratory treatment that guides them into becoming cardiac cells. The treated cells are injected into the patient’s heart in an effort to grow healthy tissue.

Stem cell therapy can improve some physiological heart function following injection of stem cells into the damaged tissue. However, the mechanism by which this improvement occurs is unclear, explains Dr. Khalpey. 

Mitochondria are known as the powerhouse of a cell due to their ability to generate a molecule known as “ATP,” which provides energy to other cells in the body. It has been shown that when cardiomyocytes (sick heart cells) are stressed (via physical or chemical methods) in the lab, and then subsequently cultured with healthy stem cells, the stem cells “donate” their mitochondria, providing a healing energy to the sick heart cells.

Scientists have made breakthroughs showing there is formation of a long, thin tube-like structure that forms between a stem cell and sick heart cell, which allows for the transfer of mitochondria. Dr. Khalpey says his research aims to measure this bio-energy transfer quantitatively between healthy stem cells and sick cardiomyocytes in the lab and in clinical trial settings.

“No one has exactly elucidated the mechanism behind this transfer or quantified the amount and function of mitochondria that are transferred,” says Dr. Khalpey.

Dr. Khalpey and Raymond Runyan, PhD, UA professor of cell biology and anatomy, are creating translatable models to understand how stem cells can be “donors” of mitochondria and repair sick heart cells and how to maximize their healing benefits.

“We expect this research will provide important information on the potential of stem cells as mitochondrial donors with better mechanistic understanding of how mitochondria work. We hope that our clinical trials with stem cells in patients with heart failure and with mechanical heart-assist devices will surpass results seen in the field thus far.”

Media Contact: Jo Marie Barkley