The lub-dub of a healthy heart pg. 3
So why grow valves in the lab?
Existing options for valve replacements are not ideal, Baldwin and Barnett argue.
Artificial (mechanical) valves are durable, but patients require lifelong blood-thinning therapy. Tissue valves – from pig, cow or human hearts, sometimes with artificial parts – don’t usually necessitate blood-thinning treatment, but they will only last a decade or so.
Enter SysCODE (Systems-based Consortium for Organ Design and Engineering), an interdisciplinary group that will work toward growing heart valves – and also teeth and pancreatic islets – in the lab.
Led by Richard Maas, M.D., Ph.D., chief of the Division of Genetics at Brigham and Women’s Hospital in Boston, SysCODE was awarded a five-year, $24 million grant last year as part of a National Institutes of Health “Roadmap” initiative that is designed to speed the movement of scientific discoveries from the bench to the bedside.
The premise of the SysCODE program, Baldwin explains, is that development follows a “blueprint” for forming complicated organs from a single cell type. It’s up to the investigators to decipher this blueprint – determine which genes are the essential ones – and use that information to push the appropriate stem cell populations to form heart valves, teeth or pancreas.
Starting with embryonic stem cells from mice, “we’re going to figure out every gene involved in each of those developmental programs,” Baldwin says. “Ultimately, I would like to be able to take patients’ own stem cells and give them back a valve.
“It’s an outrageous hypothesis,” he adds, laughing.
The investigators already know a lot about the cells that will multiply, transform and become heart valves. They are a special subset of the endocardial cells that will line the heart.