'Smart Genes' Protect Failing Hearts

November 30, 2004

Scientists testing gene therapies have found that insinuating a gene into a patient's cells is easy, but persuading it to function properly to correct a disease or malfunction is not.

That's why a novel combination approach by Duke researchers is so intriguing. It involves combining a therapeutic gene with a genetic "sensor" that controls its function. The therapeutic gene, called heme-oxygenase 1, is known to protect cells against damage from oxygen deprivation.

Victor Dzau, chancellor for health affairs, and colleagues tested the combination in rats, finding that it recognizes and responds to the oxygen deprivation that follows the reduced blood flow from coronary artery disease and heart attack. The researchers found that the gene combination protected the heart from much of the damage that weakens it during a heart attack and leads to failure.

As soon as the oxygen declines, the sensor turns on the therapeutic gene, thereby protecting the heart. Besides its potential for patients with heart disease, the strategy might also prove useful for any condition in which tissues are susceptible to the loss of blood supply, including stroke, shock, trauma, and sepsis, the researchers say. Co-authors with Dzau on the paper in the Proceedings of the National Academy of Sciences were colleagues from Duke Medical Center and Brigham and Women's Hospital in Boston.

One particularly exciting aspect of the therapy, says Dzau, is that it makes it possible to treat patients before heart damage occurs. "While drugs that can protect heart muscle are available, most patients barely make it to the hospital in time to take advantage of them," he says. "This smart gene therapy could be administered preemptively to high-risk patients months before they develop a heart attack to provide them with long-term protection from ischemic injury."