Cardiogenesis requires the formation of a diverse spectrum of muscle and non-muscle cell lineages in specific tissue compartments of the heart. Regenerative stem cell therapies for heart disease necessitate a deep understanding of the molecular mechanisms that govern the fates and differentiation of cardiovascular precursor cells during development. Recent studies have now revealed that different cardiac cell types arise from a common multipotent Isl1+ progenitor. This clonal model of heart lineage diversification would be analogous to hematopoiesis, in which a single hematopoietic stem cell can generate all of the blood cell lineages. The ability to isolate, renew and differentiate Isl1+ precursors from post-natal/embryonic hearts and from ES cells represents a powerful cell-based system which allows the characterization of signaling pathways controlling formation, renewal and lineage specification of cardiovascular progenitors.

Dr. Chien is an internationally recognized biologist specializing in cardiovascular science, as well as a pioneer in developing new therapeutic strategies to prevent the onset and progression of heart failure. Since July 2005, Chien has returned to Boston as Scientific Director of the Cardiovascular Research Center at Massachusetts General Hospital and Professor of Cell Biology at Harvard Medical School in the Department of Developmental & Regenerative Biology. He is a member of the Harvard Stem Cell Institute, where he leads the university-wide Cardiovascular Stem Cell Biology Program.

Chien has conducted groundbreaking research focused on the molecular pathways of cardiac development and disease, much of which has been published in the top tier journals in the field of biomedical science, including Cell, Science and Nature. Most recently, his laboratory discovered the "progenitor cells" (similar to stem cells) residing in the heart. These cells signal a particularly exciting breakthrough, as they are capable of generating functioning heart muscle cells. Since its publication in the journal Nature in 2005, this finding has recently been recognized as one of most highly cited papers in the biomedical field over the past six months.

Recently, the Chien lab has discovered a "master" cardiovascular stem cell that can give rise to all three major cell types in the heart: cardiac, smooth muscle, and endothelial, and is implicated in formation of heart muscle, the heart pacemaker system, and the coronary arteries (Cell, 2006). Since this master cardiovascular stem cell can be cloned from embryonic stem cells, this new finding has significant implications both for the study of the heart development, drug discovery, and disease target identification, and for longer term potential therapeutic application of the cells to repair and replace damaged heart, pacemaker, and vascular tissue.

For more information, visit
http://www.massgeneral.org/cvrc/faculty_chien_science.html

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