Considering how important an organ it is, it's a shame that the heart is so bad at repairing itself. One heart attack is rarely the end of the problem, as scarring prevents healing and often leads to further attacks. Stem cells are an emerging solution, and now researchers at the Universities of Cambridge and Washington have combined heart muscle cells and supportive cells to help mend broken hearts.
Cardiovascular diseases are the number one killer of people in the world today, so it's no surprise they're a key target for medical science to improve on. One of the most promising ways is through stem cells, which are naturally found in most organs and tissues of the body and help repair damage.
Unfortunately, the heart is one organ that these vital cells have struggled with. There's evidence that heart stem cells don't even exist, but other types could still help out. In recent studies, scientists have used general human stem cells to patch up damage to the outer heart layers, regenerated heart cells using placental stem cells, used stem cell "messengers" called exosomes to get the organ to self-repair, used newly-discovered healing cells in the fluid surrounding the heart, and aided the uptake of stem cells with hydrogel.
Often though, the problem with stem cells is that once injected to the site they're needed they don't live long enough to do much good. So for the new study, the researchers investigated new ways to keep them alive and in the right spot.
To that end, they used human stem cells to grow supportive epicardial cells – those from the outer wall of the heart – and then combine them with heart muscle cells. This combo was then transplanted onto an area damaged by heart attack, to see how well it could fix it.
Sure enough, when the researchers tested the idea on 3D human heart tissue grown in the lab, they found that the supportive cells helped the heart cells grow and mature, and improved their ability to contract and relax. In tests on rats with damaged hearts, the cell combo was shown to help the transplanted cells survive, and replenish lost heart muscle and blood vessels.
"Our research shows the huge potential of stem cells for one day becoming the first therapy for heart failure," says Johannes Bargehr, first author of the study. "Although we still have some way to go, we believe we're one giant step closer, and that's incredibly exciting."
The hope is that with further study, stem cell treatments could eventually offer a decent alternative to heart transplants, and improve the survival rates of these all-too-common illnesses.
The research was published in the journal Nature Biotechnology.
Source: University of Cambridge
