Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

'Heart-renewing' cells discovered

Regenerating cell type promises much for heart-attack survivors.

Until now, scientists believed that heart cells were non-renewable. Credit: © Punchstock

The heart contains cells that can divide and mature after birth, which might allow the organ to regenerate itself. This surprise discovery raises the possibility of transplanting these cells into hearts crippled by heart attack to mend the damage.

A heart attack kills off many cells in the heart. These are replaced by scar tissue, made up of connective-tissue cells, called fibroblasts. As a result, parts of the heart become thin and fail to beat properly.

Because fully developed heart cells do not divide, medical experts viewed the organ as unable to regenerate after injury. But Kenneth Chien, of the University of California, San Diego, and his colleagues now challenge this belief.

The researchers searched for 'cardiac progenitor cells', which are rare cells from the heart's early development that retain the ability to reproduce. They looked for cells containing the products of a gene called islet-1, which is expressed in these progenitor cells.

Tracing forward

These are very rare cells, which accounts for why they have not yet been reported Kenneth Chien , UCSD School of Medicine, La Jolla, California

By tracking cells in developing mice, Chien and his team linked adult cells expressing islet-1 with a population of embryonic cells that can give rise to heart muscle. The group also discovered these cell types in the human heart.

"These are very rare cells, which accounts for why they have not yet been reported," explains Chien. Only a few hundred progenitor cells remain in the heart after birth, and this number decreases with age, the researchers say.

In the lab, several hundred progenitor cells taken from animals after birth produced millions of cardiac-muscle cells. The progenitor cells are found mainly in the heart's pumping chambers, the team reports in Nature1.

Unlike stem cells, which have a seemingly unlimited capacity for self-renewal, progenitor cells undergo a finite number of divisions. But both types of cells have potential for use in repairing heart damage.

And according to the researchers, cardiac progenitor cells have one considerable advantage over stem cells: scientists can easily coax them into becoming fully specialized heart-muscle cells, without chemical or hormonal stimuli.

In the future, doctors might be able to capture and grow progenitor cells and then transplant them back into the patient's heart. For now, however, isolating substantial numbers of these special cells remains a technical challenge. "Therapeutic use of these cells is many years away," says Chien.


  1. LaugwitzK. L., et al. Nature 433, 647 - 653 (2005).

    ADS  CAS  Article  Google Scholar 

Download references


Additional information

UCSD School of Medicine, La Jolla, California

Related links

Related links

Related links in Nature Research

In Focus: Stem cells

Related external links

UCSD School of Medicine

Heart attack warning signs

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Khamsi, R. 'Heart-renewing' cells discovered. Nature (2005).

Download citation

  • Published:

  • DOI:


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing