Friday August 23, 2019
Home Science & Technology Scientists ha...

Scientists have grown Human Cells inside Pig Embryos with goal of growing Livers, other Human Organs in Animals

0
//
FILE - An organ procurement coordinator works on the lungs of an organ donor at Mid-America Transplant Services in St. Louis, Feb. 21, 2014. Advancements are being made in growing human organs for transplant from animals such as pigs. VOA

Scientists have grown human cells inside pig embryos, a very early step toward the goal of growing livers and other human organs in animals to transplant into people.

The cells made up just a tiny part of each embryo, and the embryos were grown for only a few weeks, researchers reported Thursday.

NewsGram brings to you current foreign news from all over the world.

Such human-animal research has raised ethical concerns. The U.S. government suspended taxpayer funding of experiments in 2015. The new work, done in California and Spain, was paid for by private foundations.

Any growing of human organs in pigs is “far away,” said Juan Carlos Izpisua Belmonte of the Salk Institute in La Jolla, California, an author of the paper in the journal Cell.

He said the new research is “just a very early step toward the goal.”

NewsGram brings to you top news around the world today.

Even before that is achieved, he said, putting human cells in animals could pay off for studies of how genetic diseases develop and for screening potential drugs.

Animals with cells from different species are called chimeras. Such mixing has been done before with mice and rats. Larger animals like pigs would be needed to make human-sized organs. That could help ease the shortage of human donors for transplants.

The Salk team is working on making humanized pancreases, hearts and livers in pigs. The animals would grow those organs in place of their own, and they’d be euthanized before the organ is removed.

Most of the organ cells would be human. By injecting pig embryos with stem cells from the person who will get the transplant, the problem of rejection should be minimized, said another Salk researcher, Jun Wu.

Check out NewsGram for latest international news updates.

Daniel Garry of the University of Minnesota, who is working on chimeras but didn’t participate in the new work, called the Cell paper “an exciting initial step for this entire field.”

Here’s what the new paper reports:

Scientists used human stem cells, which are capable of producing a wide variety of specialized cells. They injected pig embryos made in the lab with three to 10 of those cells apiece, and implanted the embryos into sows. At three to four weeks of development, 186 embryos were removed and examined.

Less than 1 in every 100,000 embryonic cells was human, which still comes to about a million human cells, Wu said. That contribution is lower than expected, he said, “but we were very happy to see we actually can see the human cells after four weeks of development.”

The cells generated the precursors of muscle, heart, pancreas, liver and spinal cord tissue in the embryos. The researchers said they plan to test ways to focus human cells on making specific tissues while avoiding any contribution to the brain, sperm or eggs.

That addresses ethical concerns that the approach could accidentally lead to pigs that gain some human qualities in their brains, or make human egg or sperm.

There was no sign of that in the new research. The government, meanwhile, has signaled that it may lift the federal funding ban soon but impose extra oversight of any proposed work.

A pig might not always have to be brought to term, Belmonte and Wu said. Even a pig fetus might provide human pancreatic cells to treat diabetes, or kidney cells to repair injuries to that organ, they said.

The University of Minnesota’s Garry said the research offers some direction about what kind of human stem cells will work best. And it shows a need for boosting the number of human cells that appear in the embryo, he said.

Hiromitsu Nakauchi of Stanford University said his own unpublished experiments with pig and sheep embryos also found a sparse contribution from injected human cells. That’s a challenge for making organs, but it might be surmounted by focusing cells on doing that job, he said.

Ethics experts were also impressed by the results. “It really does give a green light to explore more,” said Insoo Hyun of Case Western Reserve University in Cleveland.

Hyun said he understood why some people might object on moral grounds to making animals with human organs.

“It seems kind of creepy,” he said. But “this is a strategy to help save human lives” and so it is justified if properly done, he said.

Next Story

“We’re Only about 43 Percent Human”, Estimates Research

Less than half of the cells in the body are human. The rest belong to microorganisms that affect the health, mood and whether certain people respond better to certain medications

0
human
Less than half of human body is human. VOA

New discoveries about what is inside the body are making scientists rethink what makes a person human and what makes people sick or healthy.

Less than half of the cells in the body are human. The rest belong to microorganisms that affect the health, mood and whether certain people respond better to certain medications.

“So to our 30 trillion human cells, we have on average about 39 trillion microbial cells. So by that measure, we’re only about 43% human,” said Rob Knight, director of the University of California San Diego Center for Microbiome Innovation and professor of pediatrics and computer science and engineering.

Microbes affecting health

It is common knowledge that bacteria, or even viruses and fungi, exist in areas of our body, including the mouth, skin and gut. However, it is only in recent years that scientists have discovered that each person’s gut bacteria is unique, and the collection of microbes can greatly impact a person’s health — such as their weight and whether they will develop ailments such as heart disease.

Microbes in the gut can even affect mood. Researchers are studying whether conditions such as autism, multiple sclerosis and Parkinson’s disease are linked to microbes.

“They changed the way we think about biology, and changed the way we think about what it means to be human,” Knight said.

The collection of microbes in each person is different, starting from when babies are born. How they enter the world, whether vaginally or through cesarean section (C-section), whether they drink breast milk or not, the animals they are exposed to and the medications they take, can all impact their development.

“The biggest problem with antibiotics is early in childhood, and especially the combination of C-section and antibiotics and bottle feeding is especially bad for kids. We’ll see impacts on that even at age 8 to 12, in terms of their weight, even in terms of the cognitive performance,” Knight said.

The cancer puzzle

Karen Sfanos, associate professor of pathology, oncology and urology at the Johns Hopkins University School of Medicine, said researchers think at least 70% of a human body’s immunity and immune cells exist in the gut. She is studying the link between microbes and cancer.

human
There are more microbial cells in a person’s body than human cells. The microbes in the human body include bacteria, viruses and fungi, like this fungal spore bacteria in water. VOA

“There’s still many cancers out there where we have no idea what even causes the cancer. We’ve been trying to solve this puzzle, and up until this point, half the pieces were missing because we didn’t even know half the pieces existed. There’s just a tremendous amount of knowledge that’s to be gained and to be researched to understand the profound influence that these microbes might have on both cancer initiation but also therapeutic response to certain cancer therapies,” she said.

What affects microbes in an adult body most is diet and how many different types of plants a person eats.

“By eating a high-fat diet or an unhealthy diet, (it) can lead to pro-inflammatory microbes. It can cause inflammation in the gut, in your GI tract, and, unfortunately, in that scenario, the inflammation that happens in your gut can have a really long-distance effect on many other organ systems in your body,” Sfanos said.

One company, DayTwo, is using the findings of gut microbe research to fight diabetes. “The diversity and abundance of the bacteria in the gut are a very useful predictor in how people process food,” said Josh Stevens, president of DayTwo.

Since each person’s gut bacteria is different, how a body reacts to sugar is also different for each person. “So by profiling the gut, we can actually help people get to a personalized prescription for food that works for them,” Stevens said.

human
The microbes in the human body include bacteria, viruses and fungi, like E. Coli shown here. Each person’s microbes are unique to that person. VOA

Distinguishing the good from the bad

Microbes in the body are changing every day. A growing number of scientists are researching these microbes to learn which ones are good and bad. They are seeing promising results in treating a hospital-acquired infection called C. diff.

ALSO READ: Pit Bulls, Mixed Breed as Dogs Most Likely to Bite Children: Study

“You can treat C. diff by taking a stool from a healthy person and giving it to a sick person. And they typically recover in two or three days. And it has about (a) 90% cure rate, as opposed to 30% for antibiotics,” Knight said. This process is done by mixing a fecal sample from a healthy person into a liquid preparation and introducing it to a sick person via a feeding tube or colonoscopy.

Researchers are working toward a future where there is a more precise approach to weeding out the bad bacteria and introducing more good microbes into the body to improve health. (VOA)