Science Daily reports on a rebuilt heart – a mouse heart remade with human stem cells – that they’ve gotten to start beating:
For the first time, a mouse heart was able to contract and beat again after its own cells were stripped and replaced with human heart precursor cells, said scientists from the University of Pittsburgh School of Medicine.
For the project, the research team first “decellularized,” or removed all the cells, from a mouse heart, a process that takes about 10 hours using a variety of agents. Then, they repopulated the remaining heart framework, or scaffold, with multipotential cardiovascular progenitor (MCP) cells. These replacement cells were produced by reverse engineering fibroblast cells from a small skin biopsy to make induced pluripotent stem cells and then treating the iPS cells with special growth factors to further induce differentiation.
“This process makes MCPs, which are precursor cells that can further differentiate into three kinds of cells the heart uses, including cardiomyocytes, endothelial cells and smooth muscle cells,” Dr. Yang explained. “Nobody has tried using these MCPs for heart regeneration before. It turns out that the heart’s extracellular matrix — the material that is the substrate of heart scaffold — can send signals to guide the MCPs into becoming the specialized cells that are needed for proper heart function.”
After a few weeks, the mouse heart had not only been rebuilt with human cells, it also began contracting again, at the rate of 40 to 50 beats per minute, the researchers found. More work must be done to make the heart contract strongly enough to be able to pump blood effectively, and to rebuild the heart’s electrical conduction system correctly so that the heart rate speeds up and slows down appropriately.
They can get the necessary starter cells from a skin sample. Ba-dum. Ba-dum.