Scientists at the La Jolla-based Sanford Burnham Prebys Medical Discovery Institute, UC San Diego and Stanford University announced a discovery that could lead to more effective treatment for heart attacks.
The research, published in Nature Communications on Thursday, revealed a key control point in the formation of new blood vessels in the heart.
"We found that a protein called RBPJ serves as the master controller of genes that regulate blood vessel growth in the adult heart," said Mark Mercola, a professor in Sanford Burnham Prebys' Development, Aging, and Regeneration Program.
"RBPJ acts as a brake on the formation of new blood vessels," said Mercola, also a professor of medicine at Stanford and senior author of the study. "Our findings suggest that drugs designed to block RBPJ may promote new blood supplies and improve heart attack outcomes."
He said that someone in the U.S. has a heart attack every 34 seconds, which can lead to the death of tissue in the organ because of a restriction of blood supply — a condition called ischmia. The result is a severely reduced pumping capacity and difficulty breathing.
Such heart failure arises within five years in about a quarter of heart attack patients, the researchers said.
If the heart had an alternative blood supply, more muscle would remain intact, and function would be preserved, according to the scientists. Many researchers have been searching for ways to promote the formation of additional blood vessels in the heart.
"Studies in animals have shown that having more blood vessels in the heart reduces the damage caused by ischemic injuries, but clinical trials of previous therapies haven't succeeded," said Ramon Diaz-Trelles, a staff scientist at Sanford Burnham Prebys and a study author.
"The likely reason they have failed is that these studies have evaluated single growth factors, but in fact building blood vessels requires the coordinated activity of numerous factors," Diaz-Trelles said. "Our data show that RBPJ controls the production of these factors in response to the demand for oxygen."
Mice lacking RBPJ did not show any adverse effects from not having the protein, he said.
The scientists believe drugs that repress the protein might benefit patients with cardiovascular disease who are at risk of a heart attack, and could even help cancer patients.
Scientists at Washington University in St. Louis also assisted with the research, which was funded by the National Institutes of Health, Sanford Children's Health Center, American Heart Association, Burroughs Wellcome Fund of North Carolina, California Institute for Regenerative Medicine, Italian Ministry of Research and Education and the Italian Society of Cardiology.
