Stem cells derived from human heart tissue develop into multicellular, spherical structures called cardiospheres that express the normal properties of primitive heart tissue, smooth muscle and blood vessel cells, according to a study by Johns Hopkins researchers.

In a related study, cells grown in the laboratory from these cardiospheres and injected into the hearts of mice following a lab-induced heart attack migrated straight to damaged tissue and regenerated, improving the organ's ability to pump blood throughout the animal's body.

Results from both studies are to be presented Nov. 14 at the American Heart Association's annual Scientific Sessions in Dallas.

"The findings could potentially offer patients use of their own stem cells to repair heart tissue soon after a heart attack, or to regenerate weakened muscle resulting from heart failure, perhaps averting the need for heart transplants," says Eduardo Marbn, M.D., Ph.D., senior author of both studies and professor and chief of cardiology at The Johns Hopkins University School of Medicine and its Heart Institute. "By using a patient's own adult stem cells rather than a donor's, there would be no risk of triggering an immune response that could cause rejection."

In the first study, researchers took heart tissue samples from 10 patients age 20 to 80 who had recently received a heart transplant, and as part of their regular checkup to make sure the new heart was functioning properly. Researchers grew these tissues for two weeks, collecting any cardiac stem cells that started to migrate out, and then grew those loose cells with growth chemicals until they formed cardiospheres. After two weeks of growth, the cardiospheres organized into structures consisting of at least two distinct, partially overlapping layers of cells. Cells in the center of the cluster had properties most like cardiac stem cells, while cells on
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Contact: David March
dmarch1@jhmi.edu
410-955-1534
Johns Hopkins Medical Institutions
14-Nov-2005