Scientists are one step closer to fighting heart disease – the leading cause of death in the United States, killing more than 600,000 people every year, according to the Centers for Disease Control and Prevention (CDC).
The disease occurs when hardened scar tissue replaces the special cells – cardiomyocytes – that line the heart's arteries and veins. Cardiomyocytes are flexible, resistant to fatigue and keep blood flowing fast through the heart. They are also hard to reproduce.
Scar tissue in these sensitive spots narrows the blood pathways making them prone to clots and coronary failure.
Researchers at Princeton University and the University of North Carolina have developed a way to make new smooth and springy cardiomyocytes within the patient's own heart, possibly preventing heart attack.
The lead researchers on the study are Frank Conlon from the UNC McAllister Heart Institute, along with Li Qian and Ileana Cristea, both of Princeton.
They injected fibroblasts – a plentiful coronary cell type – with an engineered retrovirus, which caused the fibroblast to produce several kinds of proteins.
Those proteins then turned the fibroblasts into cardiomyocytes within a few days in lab rats. They call the cell transformation "reprogramming."
"We may be able to define pathways to increase the efficiency of fibroblast reprogramming," Conlon says in the study, just published in Cell Reports.
Over the three-day reprogramming process, researchers observed the fibroblasts produce thousands of distinct proteins, which Conlon says "revealed a carefully orchestrated series of molecular events."
Importantly, they noticed the production of one particular protein that stimulates damaged heart tissue to repair itself.
The study produced more questions and scientists are still trying to make reprogramming more efficient and to see what other cells can transform into cardiomyocytes.