Scientists create 'human liver' from stem cells

July 3, 2013
Human iPSC-derived liver bud. Credit: Takanori Takebe

Scientists in Japan said Wednesday they had grown human liver tissue from stem cells in a first that holds promise for alleviating the critical shortage of donor organs.

Creating lab-grown tissue to replenish organs damaged by accident or disease is a Holy Grail for the pioneering field of research into the premature known as .

Now Takanori Takebe of the Yokohama City University Graduate School of Medicine and a team report in the journal Nature that they grew tissue "resembling the (human) adult liver" in a lab mouse.

They first created induced pluripotent stem (iPS) cells which they mixed with other cell types and coaxed into "liver buds"—the precursor clusters that develop into a liver.

The buds, each about five millimetres (0.2 inches) big, were then transplanted onto a , where they were observed transforming into a "functional human liver" complete with blood vessels, the scientists wrote.

"To our knowledge, this is the first report demonstrating the generation of a functional from ," said the report.

The technique has yet to be tested in humans, but serves as an important , it added.

Stem cells are infant cells that can develop into any part of the body.

Until a few years ago, when iPS cells were created, the only way to obtain stem cells was to harvest them from human embryos.

This video is not supported by your browser at this time.
Liver bud formation process from human iPSC. This video shows formation of human induced pluripotent stem cell-derived liver bud by recapitulating organogenetic interactions. After mixing three-cell types at particular timing, we seeded cells onto the dish to start liver bud formation. This is a 72hour timelapse movie for liver bud forming process at the beginning of mixed cell seeding. Credit: Takanori Takebe

This is controversial because it requires the destruction of the embryo, a process to which and others object.

iPS cells are easily-obtainable that are "reprogrammed" into a versatile, primitive state from where they can develop into any kind of cell in the body.

Takebe told a press conference ahead of the report's release that the man-made liver was observed through a replacement glass skull that was fitted around the mouse's brain.

The liver developed which fused with those of the animal.

It also performed certain human-specific liver functions—producing proteins and processing specific drugs.

"We have concluded that this liver is functioning," the scientist said. "We think this is enough for improving the survival after liver failure."

Scientists commenting on the research described it as promising.

"This science opens up the distinct possibility of being able to create mini-livers from the skin cells of a patient dying of liver failure," said Malcolm Alison, professor of stem cell biology at the Queen Mary University of London.

"Human mature liver cells transplanted on their own can fail to thrive, but if immature liver cells are first combined with their normally nurturing supportive cells, they can mature in the transplanted host and function efficiently," he said in a statement issued by the Science Media Centre.

Dusko Ilic from Kings College London said "the promise of an off-shelf-liver seems much closer than one could hope even a year ago", but the strategy has yet to be proven in humans.

"Whilst the title of the paper is 'functional human liver', these liver buds do not contain the biliary structures (which drain toxins out of the liver) or immune cells that characterise real human liver," added Stuart Forbes, professor of transplantation and regenerative medicine at the University of Edinburgh.

Chris Mason of University College London said the buds may be useful for drug testing in the lab, which is currently restricted by the limited availability of cells from human cadavers.

Takebe said the method may also work in organs like the pancreas, kidneys or lungs, but it would be another 10 years before trials are done in humans.

One key requirement would be to shrink the "buds" to a much smaller size so they can be injected into the bloodstream and taken up by the body internally, he said.

More information: Paper: dx.doi.org/10.1038/nature12271

Related Stories

Adult stem cells take root in livers and repair damage

May 11, 2011

Johns Hopkins researchers have demonstrated that human liver cells derived from adult cells coaxed into an embryonic state can engraft and begin regenerating liver tissue in mice with chronic liver damage.

Japan team create liver from stem cells: report

June 8, 2012

Japanese researchers have created a functioning human liver from stemcells, a report said Friday, raising hopes for the manufacture of artificial organs for those in need of transplants.

Recommended for you

Crystal clear images uncover secrets of hormone receptors

July 31, 2015

Many hormones and neurotransmitters work by binding to receptors on a cell's exterior surface. This activates receptors causing them to twist, turn and spark chemical reactions inside cells. NIH scientists used atomic level ...

A cheaper, high-performance prosthetic knee

July 30, 2015

In the last two decades, prosthetic limb technology has grown by leaps and bounds. Today, the most advanced prostheses incorporate microprocessors that work with onboard gyroscopes, accelerometers, and hydraulics to enable ...

Flow means 'go' for proper lymph system development

July 27, 2015

The lymphatic system provides a slow flow of fluid from our organs and tissues into the bloodstream. It returns fluid and proteins that leak from blood vessels, provides passage for immune and inflammatory cells from the ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.