Stem cells may enhance capability of heart cells to regenerate

During a fatal heart attack, at least 1 billion heart cells are killed in the left ventricle, one of the heart’s two big lower pumping chambers that move blood into the body.

In less severe coronaries, dead cardiac cells are replaced by connective tissue cells that form scar tissue in the damaged heart. But the result is never very satisfactory. Scarred ventricular walls are thin, and don’t contract very well — a problem in a workhorse organ designed for sustained pumping.

Inadequate heart repair concerns British-trained developmental biologist Christine Mummery, who has made cardiac cells her specialty. She’s the Harvard Stem Cell Institute Radcliffe Fellow, and will be in residence at Harvard for a semester. (Most Radcliffe Fellows — who number about 50 a year — stay through May.)

Mummery is group leader at the Hubrecht Laboratory of the Netherlands Institute for Developmental Biology, and a specialist in converting stems cells to heart and vascular cells that act like new ones. Heart cells, Mummery believes, have an untapped regenerative capacity that can be enhanced by transplanting stem cells that grow into efficient heart muscle.

Mummery is interested in using laboratory heart cells as a model for cardiac activity — which someday might help scientists identify novel genes, or screen new drugs inexpensively.