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
The researchers published their findings in the April 23 issue of