In early-stage research, scientists at Duke University Medical Center used microRNAs to convert scar tissue that forms after a heart attack into functioning cardiomyocytes comprising heart muscle. The conversion was successful both in vitro and in a living mouse.
Though additional studies are needed to confirm this procedure’s efficacy with human cells, the method may be a promising treatment for patients with heart failure. The finding could have other therapeutic implications as well, according to Victor J. Dzau, MD, a senior author on the study who is a professor of medicine and chancellor of health affairs at Duke. “If you can do this in the heart, you can do it in the brain, the kidneys, and other tissues. This is a whole new way of regenerating tissue,” he said in a press release.
In the study, a custom combination of microRNAs was delivered into scar fibroblasts, which form after a heart attack. The fibroblasts then changed into cells resembling the cardiomyocytes.
The use of microRNAs for tissue regeneration eliminates technical problems such as genetic alterations. In addition, it avoids the ethical dilemmas sometimes linked to stem cells.
The approach will now be tested in larger animals. Dr. Dzau said therapies could be developed within a decade if additional studies advance in larger animals and humans.
In an interview with Medpage Today, Dr. Dzau explained how the research compares with similar efforts to convert scar tissue into functioning cardiomyocytes:
[Dzau] said that until recently, no other approach to converting fibroblasts to functioning cardiomyocytes had been shown to work in a living animal. He noted that a research group from the University of California San Francisco led by Deepak Srivastava, MD, recently reported in Nature that using transcription factors could achieve direct reprogramming with low efficiency in mice.
What’s different about the current study is the use of microRNAs, which are “master regulators” of numerous genes and — with their smaller size — are more easily used than transcription factors, according to Dzau.
Press release: Duke Team Turns Scar Tissue into Heart Muscle Without Using Stem Cells…
Medpage Today article: Scar Tissue Becomes Heart Muscle in Mice…
Abstract: MicroRNA-Mediated In Vitro and In Vivo Direct Reprogramming of Cardiac Fibroblasts to Cardiomyocytes
Image credit: Ravindra Gandhi
