A new model could be an important step toward making diseased hearts heal themselves, scientists say, reducing the need for bypass surgery, heart transplants, or artificial pumping devices.
For the new study, researchers removed connective tissue cells from a human heart, “reverse-engineered” them into heart stem cells, then “re-engineered” them into heart muscle cells.
The true breakthrough, however, is that the newly-created cardiac muscle cells clumped together into a single unit that visibly pumps under a microscope.
Cardiac cells made in this way don’t normally come together and beat as one, says senior author Leonard Y. Lee, chair of the surgery department at Rutgers Robert Wood Johnson Medical School. To make this happen, he and colleagues over-expressed a protein in the cells called CREG.
Fibroblasts, a cell in connective tissue, were isolated from the heart tissue and reverse-engineered—or transformed—into stem cells, so that when the CREG protein was over expressed the stem cells would differentiate into cardiac cells, Lee says.
“Heart failure has reached epidemic proportions. Right now, the only option to treat it is surgery, transplant, or connecting the patient with a blood-pumping machine. But transplantable hearts are in short supply and mechanical devices limit the patient’s quality of life. So, we are working for ways to help hearts heal themselves.”
Though still far off, Lee’s ultimate goal is to be able to remove small amounts of a patient’s native heart tissue, use CREG to convert the tissue into cardiac muscles that will work together cohesively, and re-introduce them into the patient’s heart allowing it to heal itself.
More than six million Americans are living with heart failure, according to the American Heart Association.
While most people hear the term “heart failure” and think this means the heart is no longer working at all, it actually means that the heart is not pumping as well as it should be. People with heart failure often experience fatigue and shortness of breath and have difficulty with every day activities such as walking and climbing stairs.
The paper appears in Frontiers in Cell and Developmental Biology.
Source: Rutgers University
