A group of scientists from Canada and the US has successfully used embryonic stem cells to produce heart progenitor cells which are able to make three major types of cell essential for a healthy heart. The researchers said this discovery represents a significant step in the development of human heart tissue for use in heart repair and drug testing.
The study is the work of Dr Gordon Keller, director of the McEwen Centre for Regenerative Medicine at the University Health Network in Toronto, Canada, and colleagues, and is published in the 23rd April advanced online issue of the journal Nature.
A healthy human heart needs three types of cell to work properly: cardiomyocytes (to make cardiac muscle), endothelial cells and vascular smooth muscle cells (to make blood vessels).
Previous studies have shown that these three cell lineages arise from a common cardiovascular progenitor (starter cell) that appears early during embryo growth.
Keller and colleagues followed the development of heart cells in human embryonic stem cells while they differentiated in cultures in the lab.
After stimulating the cultures with a range of growth factors, the cell masses developed from the human embryonic stem cells showed characteristics typical of heart progenitor cells with potential to turn into cardiac, endothelial and vascular smooth muscle.
After transplanting into other cell cultures, the progenitor cells differentiated into colonies that contained all three types of heart cells.
The researchers were able to establish that the colonies were clones, showing that they developed from the same cardiovascular progenitor cell.
They concluded that:
“These findings identify a human cardiovascular progenitor that defines one of the earliest stages of human cardiac development.”
In a press release, Keller said the findings means scientists can make different types of human heart cells for research:
“The immediate impact of this is significant as we now have an unlimited supply of these cells to study how they develop, how they function and how they respond to different drugs.”
“In the future, these cells may also be very effective in developing new strategies for repairing damaged hearts, following a heart attack,” he added.
According to a Reuters report, Keller and colleagues also transplanted the three types of heart cell derived in the experiment into mice with simulated heart disease and showed that their heart function improved.
Speaking in a telephone interview, Keller said that while other labs have produced heart cells from embryonic stem cells, this new study has developed a step by step process.
“Human cardiovascular progenitor cells develop from a KDR+ embryonic-stem-cell-derived population.”
Lei Yang, Mark H. Soonpaa, Eric D. Adler, Torsten K. Roepke, Steven J. Kattman, Marion Kennedy, Els Henckaerts, Kristina Bonham, Geoffrey W. Abbott, R. Michael Linden, Loren J. Field & Gordon M. Keller.
Nature advance online publication 23 April 2008.
DOI:10.1038/nature06894
Sources: McEwen Centre press statement, journal abstract, Reuters.
Written by: Catharine Paddock, PhD