April 23, 2008 -- Scientists have successfully grown "master" heart cells in a test tube and used them to significantly improve ailing heart function in mice. It's an achievement that's being lauded as another promising milestone in the quest toward cardiovascular regenerative medicine.
Researchers across the globe have been trying to coax stem cells into viable heart cells that can be used to repair or replace damaged cardiac tissue. Stem cells are the earliest precursors to cells; they have the potential to develop into a variety of different kinds of cells. A growing body of medical evidence suggests that embryonic stem cells may ultimately allow for the creation of functional heart tissue for transplants.
Now a team of U.S., Canadian, and British researchers led by Gordon Keller of the department of gene and cell medicine at Mount Sinai School of Medicine in New York reports success in growing three types of human heart cells from laboratory cultures derived from embryonic stem cells.
The human heart comprises three distinct cell types: cardiomyocytes, endothelial cells, and vascular smooth muscle cells. Each type of cell plays an important part in the makeup of functioning heart tissues.
Keller's group created the so-called master heart cells by adding a mix of growth factors and other development-related molecules to the laboratory dishes containing the stem cells at key times during the experiment. By timing these steps correctly, the researchers encouraged the cells to grow into ancestors, or "progenitors," of the three specific heart cell types.
When the team transplanted a combination of the three lab-grown heart cells into mice with simulated heart disease, their heart function improved. Researchers say their success offers hope to those aiming to develop stem cell biology techniques for the treatment of damaged human hearts.
Keller and colleagues believe that individual types of specific heart cells could be produced by isolating particular types of progenitors, an accomplishment that will help promote further understanding of heart development.
The researchers published their findings in the April 23 issue of Nature.