Researchers find protein to help in heart muscle cell regeneration

12th May 2015

Researchers have found a protein which helps to regenerate heart muscle cells in mice.

The team have been looking at how newborn mice regenerate their damaged hearts to see if the process can help in humans.

In people, heart cells stop dividing shortly after birth, leaving little chance of renewal in adulthood.

But newborn mice can regenerate heart cells up to a week after birth.

Researchers at the Weizmann Institute in Israel looked at how a protein called ERBB2, which promotes certain cancers, and a growth factor called NGR1, already being tested for treating heart failure, helped in producing new heart cells in mice.  They reported their findings in Nature Cell Biology.

On looking at how embryonic mice hearts continued to regenerate, the researchers, led by Professor Eldad Tzahor, realised that the amount of ERBB2 present was a big factor.

They concluded that heart muscle cells lacking ERBB2 did not divide and mice without the gene for ERBB2 had hearts with the features of dilated cardiomyopathy.

When adult mice had the protein reactivated, heart muscle cells grew excessively.

“Too little or too much of this protein has a devastating impact on heart function,” said Prof Tzahor.

If ERBB2 could be reactivated for a short period could you get cardiac cell renewal, the team wondered.

In mice that had had a heart attack, nearly complete heart regeneration was obtained in several weeks , the researchers said

 "The results were amazing," said Prof Tzahor. "As opposed to extensive scarring in the control hearts, the ERBB2-expressing hearts had completely returned to their previous state."

Investigation showed the heart muscle cells reverted to an earlier form, something between an embryonic and an adult cell which could then divide and differentiate into new heart cells.

Prof Tzahor and his team also looked at other proteins in the chain to identify new drug targets for treating heart disease.

"Much more research will be required to see if this principle could be applied to the human heart, but our findings are proof that it may be possible," he said.