Australian researcher part of stem cell breakthrough to repair failing hearts

08 May 2014
James Chong now based at Westmead Millennium Institute for Medical Research

Dr James Chong - a physician-scientist at Sydney’s Westmead Millennium Institute for Medical Research - and US colleagues have successfully grown heart muscle cells in sufficient numbers to repair the damaged heart of primates.

The significant breakthrough, published in the prestigious scientific journal Nature, is being described as a “bold new step” towards solving the growing epidemic of chronic heart failure, which kills more than 20,000 Australians each year.

For the first time researchers were able to grow stem cell-derived heart muscle at a sufficiently large scale to treat large animals. Injecting the cells into the animals’ infarcted hearts resulted in large-scale re-muscularisation and regeneration of the failing organ.

Dr Chong said the research is a significant breakthrough in using the new technology of regenerative medicine for human patients with heart disease, at a time when the problem is growing.

“Chronic heart disease rates in Australia and worldwide are reaching epidemic proportions and one in two people with advanced-stage heart failure will die within one year of diagnosis,” Dr Chong said.

“While adult stem cells are already being used in clinical trials on heart attack sufferers, that method has so far demonstrated only modest benefits so new treatments are urgently needed. By using pluripotent stem cells, which have superior plasticity, we were able to grow and graft stem cell-derived heart muscle in significantly larger numbers than previously possible.”

Commenting on the significance of the findings, Professor Nadia Rosenthal – Director of the Australian Regenerative Medicine Institute and leader of Stem Cells Australia’s Cardiac Regeneration and Repair theme said, “There are several important take home messages and attendant caveats in this landmark paper.

“First, it's a definitive test of the efficacy of embryonic stem cells to improve the outcome of cardiac injury in a primate context, and quite heroic in to obtain the requisite cultured cell number.  

“Second, it reports an impressive repopulation of lost cardiomyocytes in the primate hearts.  New muscles were electrically coupled although maturation was incomplete within the tested time frame, yet any muscle replacement is something that many adult stem cell trials have failed to achieve either in animal models or human patients. 

Third, although the use of human cells removes one barrier towards clinical application, the authors rightly warn against too rapid a transition to human trials, citing considerable arrhythmias induced by embryonic stem cell injection, presumably because the new tissue was not adequately synchronised with the host organ. We still have a long way to go before embryonic stem cell therapy becomes a reality for patient treatment of cardiovascular disease, but as a proof of principle this is an important step in that direction.”

This research was conducted in the laboratory of Professor Charles Murry at the University of Washington. Having now returned to Australia, Dr James Chong and a team at WMI are seeking additional funding in order to continue large animal modelling tests at Westmead in the hope of moving to human clinical trials in a few years. Click here to find out more.

Dr James Chong is an Affiliate member of the Stem Cells Australia initiative.

Chong et al (2014) Human embryonic-stem-cell-derived cardiomyocytes regenerate non-human primate hearts. Nature doi:10.1038/nature13233

Media coverage:
Sydney scientist regrows monkey's heart with stem cells [SMH] 30 April 2014
Stem-cell repair job could fix heart damage [The Australian] 30 April 2014
Australian cardiologist regrows monkey hearts with human stem cells [The Guardian] 1 May 2014
Scientists regrow monkey heart wall using human stem cells [ABC The World Today] 1 May 2014