Stem cells trigger liver regeneration

Researchers have successfully used a stem cell transplant to induce liver repair and regeneration in mice.

The finding marks the first time that the technique has been used to restore function to a damaged liver in animals and the researchers say that, in the future, such cell-based transplants could replace organ transplants in humans.

'This research has the potential to revolutionise patient care by finding ways of co-opting the body's own resources to repair or replace damaged or diseased tissue,' said Dr Rob Buckle, director of science programmes at the Medical Research Council, which funded the research.

The scientists, who reported their findings in Nature Cell Biology, investigated the function of liver stem cells known as hepatic progenitor cells (HPCs) that are able to differentiate into the multiple cell and tissue types found in the liver.

The researchers first removed HPCs from healthy mice and grew them in vitro, before transplanting them into mice with liver regeneration problems. Over several months, they observed regeneration in major areas of the liver and saw improved structure and function in the animals' organs.

A healthy liver has an impressive capacity for self-regeneration due to the presence of hepatocytes, which can renew after injury. However, liver diseases such as cirrhosis cause the hepatocytes to enter senescence - a state in which they can no longer replicate and damage to the liver becomes permanent.

It is estimated that at least two million people in the UK are affected by some form of liver disease. Liver transplants are available; however, the waiting time for appropriate donor matches is currently 145 days for adults and 72 days for children.

This research shows that HPCs grown outside the body are capable of inducing repair of the liver and restoring organ function, making them a potentially viable treatment for liver damage without the need for transplantation.

Lead author Professor Stuart Forbes of the MRC Centre for Regenerative Medicine at the University of Edinburgh, said: 'Revealing the therapeutic potential of these liver stem cells brings us a step closer to developing stem cell-based treatments for patients with liver disease.'

However, he added: 'It will be some time before we can turn this into reality as we will first need to test our approach using human cells.'