Live heart programming in turtles to cope with hypoxia

Mohammad ALHADDAD

A living embryonic heart can be programmed to survive and adapt to the effects of a low oxygen environment, according to a new study by researchers from the Universities of Manchester and North Texas.

The study, published on June 26 in the Proceedings of the Royal Society Biological, for the first time, explains the biological mechanisms of the heart that help turtles stay unique for up to six months without oxygen.

According to the study, it is the exposure to low levels of oxygen during embryonic development that program the hearts of animals to be more flexible for exposure to hypoxia for the rest of their lives.

Genetic changes
Hypoxia occurs during heart attacks, and can damage the heart during transplant surgery.

According to the study team, exposure to hypoxia during embryonic development (growth) leads to genetic changes that can help control gene activity or completely disrupt them. Scientists consider gene activity a key to making turtle heart cells better able to tolerate the absence of oxygen.

Researchers isolated cells of the heart muscle with small turtles that live as embryos at normal levels of oxygen estimated at 21% oxygen, or half the levels of natural oxygen (10%). The study revealed that early exposure to oxygen deficiency in these animals reduces the amount of oxygen that can protect muscle filaments from damage, and allow over time to shrink naturally in the absence of oxygen.

A glimmer of hope
Heart cells in turtles and humans are very anatomical, so if scientists can understand the factors that allow turtles to remain in an oxygen-free environment, it gives them hope that they will be able to apply it to humans, according to the study.

The researchers hope that this discovery will develop medical drugs that can help humans adapt to low oxygen environments. The team focuses its study on the heart, unlike any other member of the body, because it is one of the most at risk of oxygen deficiency damage.

"Turtles are wonderful creatures that can live uniquely long under the ice or in depths where there is little oxygen," said Ilan Rohr, a postdoctoral researcher at the University of Manchester, in a press release accompanying the study.

"We are excited to be the first to show that it is possible to change the degree of flexibility shown by turtles to environments where oxygen is low, by early exposure to hypoxia during embryonic development," he said.