Scientists Regenerate Mouse Heart with Human Precursor Cells

There may be hope for regenerating functional organs in humans. Scientists have stripped the cells out of a mouse heart and have replaced them with human heart precursor cells. Surprisingly, the heart was able to contract and beat again after the procedure.

Heart disease impacts millions of people in the United States. In fact, it's estimated that one person dies of heart failure every 34 seconds. This makes current research into tissue transplant and regeneration crucial for helping to treat this disease. Being able to replace a piece of tissue damaged by a heart attack could help extend the life of patients.

In order to further investigate tissue regeneration, the researchers first "decellularized," or removed all of the cells, from a mouse heart. The whole process took about 10 hours before the scientists then repopulated the remaining heart framework, or scaffold, with multipotential cardiovascular progenitor (MCP) cells. These cells were created by reverse engineering fibroblast cells from a small skin biopsy to make induced pluripotent stem cells. These iPS cells were then treated with special growth factors to further induce differentiation.

So how did these cells do in the mouse heart? After a few weeks, the heart had not only been rebuilt with human cells, it also began contracting again at a rate of 40 to 50 beats per minute. While more work needs to be done in order to make the heart contract strongly enough to pump blood, the new research is still a huge leap forward.

In the future, it may be possible to take a simple skin biopsy from a patient to derive personalized MCPs. These cells, in turn, could be used to seed a biologic scaffold and regenerate a replacement organ suitable for transplantation. Of course, this type of treatment is years if not decades away. That said, scientists are hopeful for future studies.

"One of our next goals is to see if it's feasible to make a patch of human heart muscle," said Lei Yang, one of the researchers, in a news release. "We could use patches to replace a region damaged by a heart attack. That might be easier to achieve because it won't require as many cells as a whole human-sized organ would."

The findings are published in the journal Nature Communications.