Scientists in Japan would try to grow human organs in animals after receiving government permission for the first study of its kind in the country.
The cutting-edge — but controversial — research involves implanting modified animal embryos with human “induced pluripotent stem” (iPS) cells that can be coaxed into forming the building blocks of any part of the body.
It is the first step in what researchers caution is a long path toward a future where human organs for transplant could be grown inside animals.
The research led by Stanford University genetics professor Hiromitsu Nakauchi is the first of its kind to receive government approval after Japan changed its rules on implanting human cells into animals.
Japan had previously required researchers to terminate animal embryos implanted with human cells after 14 days and prevented the embryos from being placed into animal wombs to develop.
However, those restrictions were dropped in March, allowing researchers to seek individual permits for research projects.
“It took nearly 10 years, but we are now able to start the experiment,” Nakauchi said.
The research involves generating animal embryos — mice, rats or pigs — that lack a particular organ such as a pancreas.
The modified embryos are then implanted with human iPS cells that can grow into the missing pancreas.
The embryos would be transplanted into wombs where they could theoretically be carried to term with a functioning human pancreas.
Preliminary research has produced some promising signs, including the successful growth of mice pancreases in rats.
The pancreases, when transplanted back into mice, functioned successfully and controlled blood glucose levels in diabetic mice.
However, other tests have been more complicated: Researchers were able to grow mice kidneys in rats, but rat stem cells implanted in mice failed to take.
Even though the mice kidneys developed properly in rats, the rats died shortly after birth because of complications related to the way that they were modified before receiving the mice stem cells.
Nakauchi said that the newly approved study would help understand the obstacles in the field, and cautioned that he was far from the eventual goal of trying to grow human organs in pigs.
“Although we have shown proof-of-concept studies using rodent models, to overcome the genetic distance between human and pig is not easy,” he said. “The study is just about to begin. Do not expect that we are generating human organs in a year or two.”
Implanting animal embryos with human cells creates what is known as a chimera — an entity with both animal and human cells.
The process throws up complex ethical issues, particularly over concerns that it might not be possible to completely control which organs are formed in the animal by the human iPS cells.
Rules on the process differ by country: The US has no federal restrictions on creating chimeras, while other countries prohibit chimeras being kept alive beyond two weeks.
Ethicists fear that chimeras with human brain or reproductive cells would pose serious questions about the nature of the animal being tested.
Nakauchi said that his team would be proceeding with extreme caution given the ethical concerns.
“At each step we examine embryos for the presence of human cells in the brain,” Nakauchi said. “After confirming the absence or few human cells, we go to the next step.”
North Korea yesterday made a rare mention of dissenting votes in recent elections, although analysts dismissed it as an attempt to portray an image of a normal society rather than signaling any meaningful increase of rights in the authoritarian state. The reclusive country has one of the most highly controlled societies in the world, with North Korean leader Kim Jong-un accused of using a system of patronage and repression to retain absolute power. Reporting on the results of Sunday’s election for deputies to regional people’s assemblies, the North’s state media said that 0.09 percent and 0.13 percent voted against the selected candidates
WEATHER PROBLEM: Seoul said the launch, which comes after the North said its new spy satellite is taking images of US military facilities, was rescheduled for Saturday South Korea has delayed the planned launch of its first military spy satellite set for tomorrow, officials said, days after rival North Korea said it had put its own spy satellite into orbit for the first time. Under a contract with SpaceX, South Korea is to launch five spy satellites by 2025, and its first launch using SpaceX’s Falcon 9 rocket had been scheduled to take place at California’s Vandenberg Air Force Base in the US. The South Korean Ministry of National Defense yesterday said in a brief statement that the launch was delayed due to weather conditions. Ministry officials said the
ELECTION INTERFERENCE: Meta did not publicly link the account network to the Chinese government, but said it is based in China and sought to inflate divisions within the US Someone in China created thousands of fake social media accounts designed to appear to be from Americans and used them to spread polarizing political content in an apparent effort to divide the US ahead of next year’s presidential elections, Meta said on Thursday. The network of about 4,800 fake accounts was attempting to build an audience when it was identified and eliminated by the tech company, which owns Facebook and Instagram. The accounts sported fake photos, names and locations as a way to appear like everyday American Facebook users weighing in on political issues. Instead of spreading fake content as other networks
A person known to the French authorities as a radical Islamist with mental health troubles on Saturday stabbed a German tourist to death and wounded two people in central Paris before being arrested, officials said. The attack took place close to the Eiffel Tower during a busy weekend night and came with the country on its highest alert for attacks as tensions rise against the background of the war between Israel and Hamas. “We will not give in to terrorism,” French Prime Minister Elisabeth Borne wrote on X, formerly Twitter, after the attack. French President Emmanuel Macron said he was sending his condolences
RSS