Heart cells created from human embryonic stem cells successfully restored damaged heart muscles in monkeys.
The results of the experiment appear in the April 30 advanced online edition of the journal Nature in a paper titled, “Human embryonic-stem cell derived cardiomyocytes regenerate non-human primate hearts.”
The findings suggest that the approach should be feasible in humans, the researchers said.
“Before this study, it was not known if it is possible to produce sufficient numbers of these cells and successfully use them to remuscularize damaged hearts in a large animal whose heart size and physiology is similar to that of the human heart,” said Dr. Charles Murry, UW professor of pathology and bioengineering, who led the research team that conducted the experiment.
A physician/scientist, Murry directs the UW Center for Cardiovascular Biology and is a UW Medicine pathologist.
Murry said he expected the approach could be ready for clinical trials in humans within four years.
In the study, Murry, along with Dr. Michael Laflamme and other colleagues at the UW Institute for Stem Cell & Regenerative Medicine, experimentally induced controlled myocardial infarctions, a form of heart attack, in anesthetized pigtail macaques.
The infarcts were created by blocking the coronary artery of macaque for 90 minutes, an established model for the study of myocardial infarction in primates.
In humans, myocardial infarctions are typically caused by coronary artery disease. The resulting lack of adequate blood flow can damage heart muscle and other tissues by depriving them of oxygen. Because the infarcted heart muscle does not grow back, myocardial infarction leaves the heart less able to pump blood and often leads to heart failure, a leading cause of cardiovascular death.
The goal of stem cell therapy is to replace the damaged tissue with new heart cells and restore the failing heart to normal function.
Two weeks after the experimental myocardial infarctions, the Seattle researchers injected 1 billion heart muscle cells derived from human embryonic stem cells, called human embryonic stem cell-derived cardiomyocytes, into the infarcted muscle. This was ten times more of these types of cells than researchers have ever been able to generate before.