Human stem cells stimulate the hearts of monkeys after a heart attack

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"We are talking about the world's leading cause of death [for humans]," said author of the study, Dr. Charles Murray, director of the Institute for Stem Cells and Cancer. of Regenerative Medicine at the University of Washington. "And for the moment, all of our treatments … dance around the root problem, that is, you do not have enough muscle cells."

After provoking heart attacks in macaques, with each beat dropped from about 70%, which is normal, to a 40% lower. One month later, five monkeys that received human embryonic stem cells recovered on average 10.6 percentage points versus only 2.5 in the control group.

Two of the monkeys continued to improve, and the others were euthanized a month after receiving stem cells. They improved an average of 12.4 percentage points over the next two months

However, some experts say that the value of the new study may exceed these figures, which come from a handful of monkeys. On the contrary, this may stem from how Murray's team digs deeper into the irregular heartbeats that have arisen in a subset of these animals after receiving these stem cells.

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"For several years, everyone has been focusing on why we see these arrhythmias," said John D. Gearhart, professor at the University of Pennsylvania's Perelman School of Medicine and the School of Veterinary Medicine. Gearhart, former director of the Institute for Regerative Medicine at the university, did not participate in the new study.

"It's a very important observation because now you can perhaps start designing a strategy to understand what's going on, how can we prevent that?" Gearhart said. "And that's totally, for me, the story of this article."

Still, the prospect of a 10-point improvement is not insignificant for some doctors. "19659002" This is pretty impressive, "said Dr. Joseph Wu, director of the Stanford Cardiovascular Institute and a professor in the departments of medicine and radiology of the medical school.We did not was involved in the new study

"Further studies will have to be done to further validate the concept before moving on to clinical trials," he said.

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[19659002"Everymorningwhenyougetsick"Isalight-emittingsoundintheheartofthebraintheheartoftheheart"arrhythmia""pronouncedmurray"Wehavemanygoodideasbutwehavenothadit"

A monkey in the study developed extensive arrhythmias starting 10 days after the injection of the stem cells, during more than 20 Another animal was also excluded from MRI analysis for this reason.The study initially recruited 17 monkeys but Excluded eight "because of the design of the protocol or complications … only one of which was related to cellular treatment," wrote the authors.

"Seems like the grafts we put in" Using stem cells to create an endless supply of blood "data-src-mini =" // cdn.cnn.com/cnnnext/dam/assets/170328113708- red-blood-stem-cell-0328-restricted-small-169.jpg "data-src-xsmall =" // cdn.cnn.com/cnnnext/dam/assets/170328113708-red-blood-stem-cell-0328 -restricted-medium-plus-169.jpg "data-src-small =" http://cdn.cnn.com/cnnnext/dam/assets/170328113708-red-blood-stem-cell-0328-restricted-large- 169.jpg "data-src-medium =" // cdn.cnn.com/cnnnext/dam/assets/170328113708-red-blood-stem-cell-0328-restricted-exlarge-169.jpg "data-src-large = "// cdn.cnn.com/cnnnext/dam/assets/170328113708-red-blood-stem-cell-0328-restricted-super-169.jpg" data-src-full16x9 = "// cdn.cnn.com /download.aspx red-blood-stem-cell-0328-restricted-small-11.jpg "data-demand-load =" not-loaded "data-eq-pts =" mini: 0 , xsmall: 221, small: 308, medium: 461, large: 781 "src =" data: image / gif; base64, R0lGODlhEAAJAJEAAAAAAP /////// wAAACH5BAEAAAIALAAAAAAQAAkAAAIKlI + py + 0Po5yUFQA7 "/>

"The heart works on electric currents. It means that everything you graft … you have to get cells electrically coupled to other cells and so beat in unison, "said Gearhart.

This is Of a problem that Murray must solve before he can achieve his goal, move on to early human trials by 2020. (Three of the study's authors, including Murray, are founders of science and technology. hold a stock in a company that plans to help fund future phase clinical trials for this research.)

Monkeys were on immunosu pungant drugs so that they do not reject the cells of the human donor. a tumor risk, which Murray reported not to have observed in cardiac tests

Previous studies have shown that human embryonic stem cells improve heart function in smaller animals such as mice, rats We do not know how the treatment would be for larger animals such as monkeys.

"Many people have cured heart disease in mice, who heal five times a year," joked Murray. that a macaque is still much smaller than a human adult, and it is unclear how this treatment could be scaled up in human trials

"We are still concerned by the species differences between all the organs and tissues that we have to find them, "said Gearhart." And many times we ignore them at our peril. "

Tiny cells [19659022] The new study comes several years after a similar study conducted in 2014 by the Murray group suggesting that human embryonic stem cells could regenerate the heart muscle of primates., But this study did not measure how much the heart could pump accordingly.

Embryonic stem cells come from day-old embryos and have therefore been the subject of political controversy.But their strength lies in their ability to himself differentiate into several types of cells, including "genuine" cardiac muscle cells, says Wu.
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This is not the case of adult stem cells, which are present in everyone and can be collected in places like bone marrow, fat and heart. . These stem cells are thought to work by secreting molecular signals to the surrounding heart, not by turning into cardiac muscle. And they end up dying.

Previous research on the impact of adult stem cells on patients with heart failure suggested that these cells are not harmful to humans – but it is less clear that health benefits . "Overall, these cells are fairly safe, but at the same time, we do not see a dramatic improvement in heart function," which is often measured in the percentage of blood that a heart pumps with each pressure. 19659033] Despite the lack of definitive evidence that this type of therapy works in humans, direct-to-consumer consumer clinics in the United States and abroad offer unproven stem cell therapies. A survey conducted in 2017 with these clinics in the United States that offer stem cell treatments for heart failure revealed that most of those who responded did not need medical records or employed a cardiologist certified by the council. They charge an average of $ 7,700 per treatment using a patient's own stem cells and $ 6,000 per treatment for donor cells

FDA attacks at clinics marketing unapproved therapies

The US Food and Drug Administration has repressed these clinics in the past, by recently filing two federal complaints in May to permanently ban two clinics from commercializing stem cell products without regulatory approval. The agency accused them of "significant deviations" from the requirements of good manufacturing practices.

"Personally, I think it's not a good idea to go to these clinics … and [get] injected with these stem cell therapies that have not been proven ", said Wu.

" Progress "

The" grafts "of heart muscle in the Murray study accounted for an average of 11.6% of the size of the damaged tissue in cutting off his blood supply.

Over time, new cardiac muscle cells of monkeys appeared to develop, vascularize and result in decreased scar size and better heart function, according to the study

. his own, said Gearhart. Previous studies suggest that heart cells multiply at a rate of about 1% per year.

Some doctors remain unsure that the cells in the new study had really remineralized the heart as opposed to the procedure and the impact on the surrounding cells. Human embryonic stem cells have also been studied in the United States for treating spinal cord injury and retinal degeneration, Murray said.

Gearhart stated that the document is "an important contribution". the problem. "However, he remains hopeful

" The heart is one of my loves – do not play on the words, "said Gearhart.

CNN's Susan Scutti contributed to this report.

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