Healing hearts

October 18, 2018

heart muscle cells
HSCI researchers are converting induced pluripotent stem cells into heart muscle cells in a dish.


Research in the Harvard Stem Cell Institute (HSCI) Cardiovascular Disease Program centers on ten laboratories at Harvard University and its eight affiliated hospitals. Their shared goal is to develop new treatments for heart disease.

“We’re interested in helping people who have damaged hearts. To do that, we use a number of stem cell and regenerative medicine strategies to promote healing,” says program leader Richard Lee, M.D., Professor of Stem Cell and Regenerative Biology at Harvard University and Professor of Medicine at Brigham and Women's Hospital.

The HSCI approach to cardiovascular disease

“We’ve known for many years that the heart has a very limited ability to regenerate on its own. That’s why research in this program focuses on two main challenges: reprogramming other types of cells to make new heart tissue, or making the heart’s own cells divide so they can participate in repair,” says Lee.

HSCI researchers are exploring different ways to create new human heart cells from induced pluripotent stem (iPS) cells, and to deliver those new heart cells effectively to heart failure patients.

“Although it has been postulated for over a decade that the heart has its own source of stem cells that can be used for repair, extensive data over the past five years indicate that there are no adult stem cells in the adult heart,” explains Lee. “Reaching that fundamental conclusion now allows us to focus on using other sources of stem cells, or the heart’s own mature cells, to achieve heart regeneration.”

What’s the problem?

One common problem experienced by patients with heart disease is that their heart stops pumping as well as it should, because heart cells die and are not replaced.

“We want to make cells in the laboratory to replenish the heart’s supply of cells, or get the cells that are already there to multiply,” adds Lee. “There will continue to be advances in artificial mechanical pump technology, but mechanical pumps will likely never be as good as your own heart.”

HSCI investigators are also interested in most common form of heart failure in the elderly, which has to do with how the heart fills with blood – it squeezes normally, but it doesn’t fill properly.

“The type of heart failure with a filling problem affects so many people, but there are no treatments available. We collaborate with groups that specialize in the science of aging to understand why this happens, because we need to know a lot more before we can solve the problem,” explains Lee. “It’s essential to understand what aging processes are at work here, because the problem is growing rapidly throughout the world.”

Program highlights

Researchers in the HSCI Cardiovascular Disease Program publish regularly in peer-reviewed journals, contributing significantly to progress in this crucial area of biomedical research. Some past achievements include:

  • Exercise and the heart: Showed that exercise has a rejuvenating effect on heart tissue.
  • ‘Heart disease-on-a-chip’: Used patient stem cells, taken from the skin, to replicate the patient’s genetic disorder, Barth’s Syndrome, in the laboratory.
  • 3D modeling: Bioengineered a A 3-D model of a human heart ventricle, dramatically improving the precision of heart-disease research.
  • Blood vessels: Made new blood vessels by reprogramming human iPS cells.
  • Heart muscle: Stimulated internal repair using modified messenger RNAs.

Laboratories of the HSCI Cardiovascular Disease Program

Many HSCI-affiliated laboratories explore stem cell and regenerative medicine approaches that advance our understanding of the diseases of aging, including heart disease. Those that focus specifically on cardiovascular disease include:

Find out more

To learn more about how researchers use stem cells to understand cardiovascular disease, visit "A Closer Look at Stem Cells" — an information resource for patients maintained by the International Society for Stem Cell Research.