More than 800,000 Americans are expected to experience a heart attack this year. While most will survive, many will be left with permanent heart damage that cannot naturally heal. “Many tissues in your body, such as the skin or the liver, can multiply and grow back. But the heart muscle is unable to do that,” said UCLA cardiologist and professor Arjun Deb. “When your heart muscle dies, you lose that muscle forever.”
Researchers at University of California campuses are working on new treatments that could change this reality by helping damaged hearts heal. These efforts are supported by federal funding and focus on three main approaches.
One approach involves an injectable gel developed by UC San Diego bioengineering professor Karen Christman. The gel is made from extracellular matrix (ECM), a substance produced by the body to give tissues their structure. After a heart attack, ECM calms inflammation and forms a scaffold that attracts new cells, including those forming blood vessels. “That stimulates the heart to have less scar tissue and preserve more cardiac muscle,” Christman explained.
In a 2019 clinical trial, Christman showed it was safe to inject ECM directly into the heart using a catheter. Patients who received the treatment were able to walk faster than those who did not, suggesting improved heart function. Plans are underway for another clinical trial to test whether ECM can be delivered through a blood vessel feeding the heart for quicker and less invasive administration.
A second strategy targets cellular energy in damaged hearts. Professor Arjun Deb discovered that blocking a molecule called ENPP1 allows heart cells to access more energy needed for healing after injury. In animal studies simulating heart attacks, only 5 percent of treated mice developed heart failure compared with over 50 percent of untreated mice. Deb’s team is now conducting a phase 1 clinical trial following FDA clearance to test the safety of this drug in humans.
“This research represents a radical departure from existing lines of investigation which have led to the current drugs,” said Deb. Most current medications slow tissue decline but cannot reverse existing damage. He added: “My team and I are enormously grateful to the NIH for believing in us and we hope to deliver soon to the American people a new therapy for heart disease.” This work has been funded entirely by state and federal agencies such as the National Institutes of Health.
The third line of research draws inspiration from zebrafish, which can regenerate their hearts after injury—a capability humans lack despite sharing similar genes with these fish during early development. Researcher Martik is using CRISPR technology on human stem cell models to adjust gene expression so it mimics zebrafish genetics, aiming to induce regeneration in human hearts after injury.
Martik credits steady support from the National Institutes of Health for progress in this area and estimates therapies based on this research may become available within several years.
All three projects rely heavily on federal funding from agencies like NIH. Recent budget negotiations threatened significant cuts to these agencies, which could have slowed scientific discovery and affected jobs and families across the country. Through its Speak Up for Science campaign, UC encouraged community members to urge lawmakers against these cuts.
As a result, Congress passed a budget preserving bipartisan funding for NIH and other science agencies for another year—a decision considered crucial amid ongoing challenges facing American science research efforts.
Looking ahead, UC plans continued advocacy for federal research funding as part of its commitment to advancing discovery and supporting economic growth through scientific leadership.
