Scientists restore cell function and heartbeats in dead pigs, blurring the line between life and death

two pigs with glued ears smell a human hand

Pigs stand on an experimental farm of the Ludwig Maximilians University of Munich in Oberschleissheim, Germany, where scientists use genetic engineering to grow donor organs in pigs, on January 24, 2022.Lucas Barth/Reuters

  • Yale neuroscientists have restored some cellular function, heartbeat and blood flow in dead pigs, they said Wednesday.

  • The discovery shows that the intervention can stop cell death and preserve organs after death.

  • The new technology could lead to more organs for transplant and may one day help reverse death.

In a feat that blurs the lines between life and death, researchers at Yale School of Medicine have restored some cellular function in the organs of dead pigs. The achievement, published in Nature on Wednesday, sparks hopes for future medical breakthroughs that could save thousands of lives.

One hour after death, the researchers connected the pigs to a system of pumps, heaters and fillers called OrganEx. By artificially flushing the pigs’ organs with blood – a process called perfusion – they restored molecular and cellular function in the heart, brain, liver and kidneys.

The hearts even contracted to pump blood, indicating renewed electrical activity, and restored full blood circulation to the pigs’ bodies. There was no sign of electrical activity in the brain. However, scientists say they have uncovered a previously unknown ability of mammalian cells to recover after blood flow is interrupted.

“Cells are actually not dying as fast as we thought they were, which essentially opens up the possibility for intervention,” Zvonimir Vrselja, a neuroscientist on the research team at Yale, said at a press conference. “If we intervene properly, we might be able to tell them not to die.”

Unlocking this ability could allow clinicians to preserve more human organs for donation after death, reducing the transplant organ shortage and saving thousands of lives. The new technology could also revolutionize life-sustaining treatment. Some researchers said the discovery could even pave the way for bringing people back to life hours after death.

“Death is not an instantaneous event, but a gradual process, and we’ve got an extra tool to push it along,” said Anders Sandberg, a neuroscientist at the University of Oxford’s Future of Humanity Institute, who was unrelated to the study. a statement.

The same research team previously developed a perfusion system called BrainEx. In 2019, this system restored some structure and function to the brains of dead pigs four hours after they were decapitated.

Death is more reversible than scientists thought

Electrocardiogram shows a mostly flat heartbeat with an image of muted cells on the left versus a clear heartbeat and bright cells on the right

Representative images of electrocardiogram traces in the heart (top), immunostaining for albumin in the liver in ECMO-perfused organs, left, and OrganEx, right.David Andrijevic, Zvonimir Vrselja, Taras Lysyy, Shupei Zhang; Sestan Laboratory; Yale School of Medicine

The OrganEx procedure could one day save people who die from drowning, heart attacks, massive bleeding from car accidents or athletes who die suddenly from a heart defect, according to Dr. Sam Parnia, director of critical care and resuscitation research at New York University. . Grossman School of Medicine, who was unrelated to the new study.

With organ tissues preserved and cell death delayed, doctors will have time to unblock the artery that caused the heart attack or repair the torn vessel that caused the patient to bleed.

“Alternatively, healthy people, including athletes who die, but in whom the cause of death is treatable at any time, can potentially be brought back to life. And if the cause of death is untreatable, then their organs can be preserved to give life to thousands of people every year,” Parnia said in a statement.

“Scientifically, death is a biological process that remains treatable and reversible for hours after it has occurred,” he added.

However, the Yale researchers cautioned against getting too excited about life after death.

“This is a long way from being used in humans,” Dr. David Andrijevic, a neuroscientist from the research team at Yale, said in the briefing, adding, “It doesn’t restore all function in all organs.”

Better organ maintenance could save thousands of lives

Normally, when a heart stops beating and blood stops flowing, it causes other organs to swell. Blood vessels collapse and block new blood flow.

By preventing swelling and restoring full circulation, the new OrganEx technology could one day expand the window for saving organs from healthy people who have died. This would allow more organ donations, potentially saving thousands of people who otherwise die on transplant waiting lists.

This new ability to restore organ cell function could also lead researchers to more effective life support.

To sustain patients whose hearts or lungs have stopped working, hospitals use a technique called extracorporeal membrane oxygenation (ECMO) to flush blood through the malfunctioning organ, a process called perfusion. ECMO only slows cell death and often fails to fully saturate the organs with blood, leaving some smaller blood vessels to collapse.

three medical staff wearing protective plastic masks operate a machine and tubes connected to a patient lying flat

Medical staff in protective suits treat a patient with COVID-19 on extracorporeal membrane oxygenation (ECMO) therapy, in the Intensive Care Unit at Havelhoehe Community Hospital in Berlin, Germany, on December 6, 2021.Fabrizio Bensch/Reuters

OrganEx is “like ECMO on steroids,” said Dr. Nenad Sestan of the Yale neuroscience group, and in the new study it fared better than ECMO. The organs showed signs of being completely flushed with blood and fully oxygenated, with less bleeding and inflammation. The researchers even observed patterns of gene expression in some cells that indicated the tissues were repairing themselves.

These potential new capabilities — preserving more organs for transplant, providing more effective life support and reviving people whose blood has stopped flowing — require much more research. They also have moral implications.

“There is a challenging ethical issue in determining when radical life support is simply futile, and as technology advances we may find more ways to keep bodies alive despite not being able to revive the person we really care about. “A lot of work remains to find criteria for when further treatment is futile, and also how to bring people back from the brink,” Sandberg said.

Read the original article on Business Insider

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