Professor Graham and his team embarked on their research to understand how the heart develops after birth and why heart muscle cells lose their ability to divide and make new cells. Their research markedly shifted the goal posts and showed that heart muscle cells actually retain an ability to divide until adolescence. This discovery holds great promise for new approaches to managing a range of heart conditions.
In Australia, more than 2000 babies are born with congenital heart conditions each year.1
For more than one hundred years it was thought that the heart, much like the brain, stops being able to make new muscle cells soon after birth, limiting the organ’s ability to repair itself after injury.
However, in an exciting discovery with colleagues in the US, Professor Robert Graham and his team discovered for the first time that heart muscle cells can replicate long after birth.
“Surprisingly, we showed that heart muscle cells retain the ability to make new cells until early adolescence.
“Our work seeks to understand how the heart develops after birth and, in so doing, understand why heart muscle cells lose their ability to divide and make new cells,” Professor Graham explained.
The discovery that the heart can regenerate itself – at least until just before adolescence – holds great promise for new approaches to managing congenital heart disorders in children.
"This work promises to revolutionise our understanding of postnatal heart development with profound implication for treating a variety of heart conditions."
“This opens a window of opportunity to more effectively treat some forms of congenital heart disease in which the heart muscle hasn’t developed properly.
“By allowing proper healing of the injured or mal-developed heart, we may be able to markedly improve outcomes after heart attacks and prevent the need for major and repeated surgery in children with congenital heart disease,” Professor Graham remarked.
The findings challenge traditional thinking about how the adult heart might undergo repair and remodelling after injury, and how scientists may reactivate heart muscle cells damaged after a heart attack in adults.
The research provides new hope that, given the appropriate stimuli, adult heart muscles might be able to divide again to repair damage caused by disease or myocardial infarction in adults.
“It may be possible to reactivate the ability of heart muscle cells to divide and therefore to allow proper healing of the injured heart,” Professor Graham concluded.
Now that Professor Graham and his team have shown that heart muscle cells actually retain an ability to divide until adolescence, they are setting out to define the precise molecular mechanism that stimulate their division after birth – insights that may then be applied to stimulate heart muscle cell division at later time.
Cardiovascular disease in Australia
The inability of heart muscle cells to divide and make new cells limits repair of the heart in response to injury, such as some forms of congenital heart disease, a heart attack or high blood pressure. This results in a profound increase in death and disability from these injurious heart conditions. Cardiovascular disease is one of Australia’s leading causes of death, leading to 29.5% of all deaths in 2013.2 However, due to research, the overall death rate from acute cardiovascular disease has dropped by 80% since the 1960s.3
1 AIHW, 2011. Cardiovascular disease: Australian facts 2011. Cardiovascular disease series. Cat. no. CVD 53. Canberra: AIHW.
2 ABS, 2015, Causes of death 2013. No. 3303.0.
3 AIHW, 2011. Cardiovascular disease: Australian facts 2011. (Cat. no. CVD 53). AIHW: Canberra.