Mexican fish holds the key to heart regeneration

British researchers discovered that one of its genes could play a key role in genetic research

Mexican tetra fish holds the key to heart regeneration
The species’ scientific name is Astyanax mexicanus. It lives near water surfaces in subtropical climates - Photo: Special/EL UNIVERSAL
English 22/11/2018 14:56 Newsroom & Agencies Mexico City Notimex Actualizada 14:57

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Cardiovascular problems are one of the main causes of death in Mexico and many other countries around the world. However, there now seems to be a small light at the end of the tunnel for this type of illness.

British researchers discovered that Mexican tetra freshwater fish can fully regenerate their hearts after an injury thanks to three areas of their genome, which could provide clues to find future genetic treatments to help people.

The species’ scientific name is Astyanax mexicanus. It lives near water surfaces in subtropical climates and can be found in streams and rivers of central and eastern Mexico. Scientists discovered that one of its genes could play a key role in the field of genetic research due to its capability to regenerate heart tissue.

The research team, funded by the British Heart Foundation, used the QTL analysis (quantitative traits locus) to study two types of tetra Mexican fish, those that live in rivers and can auto-cure their heart tissue, and those that live in cave waters and are unable to regenerate heart tissue.

Scientists say that the cave fish once lived in the rivers of northern Mexico, but were dragged to the caves by flood waters about 1.5 million years ago and evolved, losing their sight and color because they lived in perpetual darkness.

When comparing the result of the analysis to the two types of fish, they found that Irrc10, a protein coding gene, was much more active after a cardiac injury in those living in rivers.

To corroborate it, they "turned off" the gene in a different species, the goat fish, which can regenerate itself, and found that it could not repair its heart without leaving scars, concluding that the absence or low activity of Irrc10 reduces tissue regeneration.

The scars prevent the heart muscle from contracting properly and reduce the ability of the heart to pump blood throughout the body.

Thus the team of scientists from the University of Oxford, led by Dr. Mathilda Mommersteeg, found that successful regeneration of the heart muscle comes from a delicate interaction between the proliferation of cardiomyocytes and healing, a process that requires Irrc10.

This means that the study of both the regeneration and scarring process in this species could hold the key to helping our hearts regenerate and maintain their efficiency in pumping blood.

The researchers hope that their finding, published in the journal Cell Reports, will one day cure heart muscle in patients who have suffered a heart attack, since the Irrc10 gene is also present in humans and is related to a condition called dilated cardiomyopathy.

They suggest that in the future it might be possible to regenerate damaged human hearts by artificially modifying the functioning of Irrc10 and other genes with drugs or genetic editing techniques.

Thousands of people around the world live with heart failure, often as a result of a heart attack, because it is impossible for them to regenerate their damaged and scarred hearts.