Heartrepair gene found in fish
A small fish may hold the key to repairing damaged hearts, reports Emma Bowden, of BPA.
Afish that can repair damage to its own heart could inspire treatment to heal the human organ, a study has found.
Scientists from the University of Oxford found that a gene called lrrc10 is linked to heart regeneration in Mexican tetra fish.
People suffering from heart failure, often caused by a heart attack, are unable to heal their scarred heart muscle and the only cure is a heart transplant.
Researchers hope the study, funded by the British Heart Foundation and published in Cell Reports, will help patients living with the condition.
Dr Mathilda Mommersteeg, of the University of Oxford, and her team visited rivers and caves in Mexico to study two types of fish. The river surface fish can regenerate their hearts, while some cavefish cannot and form a permanent scar.
About 1.5 million years ago, tetra fish living in the rivers of northern Mexico were washed into caves by seasonal floodwaters and evolved to suit their new environment, losing their sight and colour because of the perpetual darkness.
Scientists tested both species and found that lrrc10, a heart muscle gene also found in mice and humans, and caveolin were more active in fish following heart surgery.
Researchers then switched off the gene in a different species with selfhealing abilities, the zebrafish, which was then unable to repair its heart without scarring.
The lrrc10 gene is already linked to a heart condition called dilated cardiomyopathy (DCM) in humans. Studies in mice have shown the gene is involved in the way heart cells contract with every heartbeat.
‘‘These remarkable findings show how much there is still to learn from the rich tapestry of the natural world,’’ British Heart Foundation associate medical director Prof Metin Avkiran said.
‘‘It’s particularly interesting that the ability of the river fish to regenerate its heart may arise from an ability to suppress scar formation.
‘‘We now need to determine if we can exploit similar mechanisms to repair damaged human hearts,’’ he said.
Survival rates for heart failure had barely changed over the last 20 years, and life expectancy was worse than for many cancers.
‘‘Breakthroughs are desperately needed to ease the devastation caused by this dreadful condition,’’ Mommersteeg said.
‘‘A real challenge until now was comparing heart damage and repair in fish with what we see in humans.
‘‘But by looking at river fish and cave fish side by side, we’ve been able to pick apart the genes responsible for heart regeneration.
Heart failure was a cruel and debilitating illness that more than half a million people across the UK were living with, she said.
‘‘It’s early days but we’re incredibly excited about these remarkable fish and the potential to change the lives of people with damaged hearts.’’