Heart Attack Scar Tissue Regenerated in Lab

Scar tissue that forms after heart attack converted into heart muscle using microRNA

(RxWiki News) Following a heart attack, scar tissue comprised of cells called fibroblasts accumulates. Since the heart muscle can't easily regenerate, the patient is at an increased risk of heart failure.

Researchers have discovered a method that, for the first time, allows them to convert such scar tissue into regenerated heart muscle using microRNA in a laboratory.

"Seek immediate heart attack treatment to minimize damage."

Victor J. Dzau, MD, the study’s senior author and James B. Duke Professor of Medicine at Duke University Medical Center, noted that previously researchers have tried various approaches, including using stem cells, to regenerate damaged heart muscle tissue.

He said this marks the first study to utilize microRNA, which are small molecules that control gene expression, to reprogram fibroblasts into heart muscle cells. Investigators have successfully converted tissue both in lab cell cultures, and also in mice.

Using microRNA has proved easier than some other regenerating approaches such as stem cells. Dr. Dzau noted that stem cells are difficult to work with. In addition, there are ethical issues surrounding their use. MicroRNA, on the other hand, overcomes those challenges, and could also be used for tissue damaged from other conditions such as stroke or a spinal cord injury.

During the study researchers identified a combination of three microRNA types that convert fibroblasts to muscle cells. The microRNA serves as master switches, with each regulating genes by turning them on or off. They will next attempt to use microRNAs to repair damaged hearts and improve heart function in larger animals.

Human studies could follow if the procedure is found safe in the next round of pre-clinical studies.

“If everything comes to fruition, I think we will see this as a therapy in the next decade,” Dr. Dzau said. “Conceivably, we’ll use it to regenerate hearts damaged by heart attacks, avoiding heart failure and saving lives.”

The study was published in Circulation Research, an American Heart Association journal.

Review Date: 
April 24, 2012