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.”
Tens of thousands of Filipino Catholics yesterday twirled white cloths and chanted “Viva, viva,” as a centuries-old statue of Jesus Christ was paraded through the streets of Manila in the nation’s biggest annual religious event. The day-long procession began before dawn, with barefoot volunteers pulling the heavy carriage through narrow streets where the devout waited in hopes of touching the icon, believed to hold miraculous powers. Thousands of police were deployed to manage crowds that officials believe could number in the millions by the time the statue reaches its home in central Manila’s Quiapo church around midnight. More than 800 people had sought
DENIAL: Pyongyang said a South Korean drone filmed unspecified areas in a North Korean border town, but Seoul said it did not operate drones on the dates it cited North Korea’s military accused South Korea of flying drones across the border between the nations this week, yesterday warning that the South would face consequences for its “unpardonable hysteria.” Seoul quickly denied the accusation, but the development is likely to further dim prospects for its efforts to restore ties with Pyongyang. North Korean forces used special electronic warfare assets on Sunday to bring down a South Korean drone flying over North Korea’s border town. The drone was equipped with two cameras that filmed unspecified areas, the General Staff of the North Korean People’s Army said in a statement. South Korea infiltrated another drone
COMMUNIST ALIGNMENT: To Lam wants to combine party chief and state presidency roles, with the decision resting on the election of 200 new party delegates next week Communist Party of Vietnam General Secretary To Lam is seeking to combine his party role with the state presidency, officials said, in a move that would align Vietnam’s political structure more closely to China’s, where President Xi Jinping (習近平) heads the party and state. Next week about 1,600 delegates are to gather in Hanoi to commence a week-long communist party congress, held every five years to select new leaders and set policy goals for the single-party state. Lam, 68, bade for both top positions at a party meeting last month, seeking initial party approval ahead of the congress, three people briefed by
Indonesia and Malaysia have become the first countries to block Grok, the artificial intelligence (AI) chatbot developed by Elon Musk’s xAI, after authorities said it was being misused to generate sexually explicit and nonconsensual images. The moves reflect growing global concern over generative AI tools that can produce realistic images, sound and text, while existing safeguards fail to prevent their abuse. The Grok chatbot, which is accessed through Musk’s social media platform X, has been criticized for generating manipulated images, including depictions of women in bikinis or sexually explicit poses, as well as images involving children. Regulators in the two Southeast Asian