December 1, 2006

MGH researchers identify master cardiac stem cell

Researchers from the MGH Cardiovascular Research Center (CVRC) have discovered what appears to be a master cardiac stem cell, capable of differentiating into the three major types of cells that make up the mammalian heart. In their report receiving early online release at the journal Cell, the scientists describe identifying these progenitor cells in mice, cloning them from embryonic stem cells and showing that they can differentiate into cardiac muscle, smooth muscle and endothelial cells.

"It now appears that cardiac cells develop in the same way that blood cells do, with a master stem cell giving rise to the entire range of cells," says Kenneth R. Chien, MD, director of the MGH-CVRC and senior author of the Cell paper (right). "These cells may be excellent candidates for cardiac muscle regeneration studies, without the risk of tumor formation posed by embryonic stem cells or the limited effectiveness seen in studies using other cell types." Chien also leads the cardiovascular program at the Harvard Stem Cell Institute.

In 2005, Chien's team, then at the University of California at San Diego, described finding a group of cardiac muscle progenitor cells in heart tissue from newborn rats, mice and humans. The current study first identified a small population of embryonic cells in mice that can develop into all three types of cardiac cells — the contracting cardiac muscle cells and the smooth muscle and endothelial cells that make up blood vessels. The research team then was able to generate these newly identified progenitors — parental cells that give rise to the cells identified in the 2005 study — from embryonic stem cells and then to clone them.

The co-first authors of the report are Alessandra Moretti, PhD; Leslie Caron, PhD; and Atsushi Nakano, MD; and co-authors from the MGH-CVRC are Jason Lam, PhD; Yibing Qyang, PhD; Lei Bu, PhD; Silvia Puig, and Karl-Ludwig Laugwitz, MD, PhD.