Mouse heart beats again with human stem cells
15 Aug 2013 by Evoluted New Media
A decellularised mouse heart was able to contract and beat again when it was rebuilt with human stem cells.
The research, reported in Nature Communications, suggests regenerating a functional organ by replacing cells with human induced pluripotent stem (iPS) cells in a three-dimensional scaffold could have promising results in transplantation.
Senior Investigator of the study, Dr Lei Yang, Assistant Professor of Developmental Biology at Pittsburgh School of Medicine, said: “Scientists have been looking to regenerative medicine and tissue engineering approaches to find new solutions for this important problem. The ability to replace a piece of tissue damaged by a heart attack, or perhaps an entire organ, could be very helpful for these patients.”
First of all, Yang and his team removed all the cells from a mouse heart. They then repopulated the remaining heart framework with mulipotential cardiovascular progenitor (MCP) cells which were produced by reverse engineering fibroblast cells from a small skin biopsy and then treating the resulting iPS cells with growth factors to induce differentiation into heart precursor cells.
Yang said: “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. 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 the addition of human cells, the mouse heart began contracting again after a few weeks with a heart rate of 40 to 50 beats per minute.
The team are now focusing on making the heart contract strongly enough to be able to effectively pump blood and on rebuilding the heart’s electrical conduction system so that the heart rate speeds up and slows down appropriately.
Yang said: “One of our next goals is to see if it’s feasible to make a patch of human heart muscle. We could use patches to replace a region damaged by a heart attack. That might be easier to achieve because it won’t require as many cells as a whole human-sized organ would.”
