Mini-livers show promise to reduce animal use in science

Dr Meritxell Huch from Cambridge University's Gurdon Institute, who tonight receives the National Centre for the Replacement, Refinement and Reduction of Animals in Research (NC3Rs) 3Rs Prize, has developed a method that enables adult mouse stem cells to grow and expand into fully functioning three-dimensional liver tissue.

Using this method, cells from one mouse could be used to test 1000 drug compounds to treat liver disease, and reduce animal use by up to 50,000.

Growing hepatocytes (liver cells) in the laboratory has been attempted by liver biologists for many years, since it would reduce their reliance on using mice to study liver disease and would open up new opportunities in medical research and drug safety testing. Until now no laboratory has been successful in deciphering how to isolate and grow these cells.

Liver stem cells are typically found in a dormant state in the liver, only becoming active following injury to produce new liver cells and bile ducts. Dr Huch and colleagues at the Netherlands' Hubrecht Institute located the specific type of stem cells responsible for this regeneration, which are recognised by a key surface protein (Lgr5+) that they share with similar stem cells in the intestine, stomach and hair follicles.

By isolating these cells and placing them in a culture medium with the right conditions, the researchers were able to grow small liver organoids, which survive and expand for over a year in a laboratory environment. When implanted back into mice with liver disease they continued to grow, ameliorating the disease and extending the survival of the mice.

Having further refined the process using cells from rats and dogs, Dr Huch is now moving onto testing it with human cells, which would not only be more relevant to research into human disease, but also translate to the development of a patient's own liver tissue for transplantation.

Commenting on the new method's potential to reduce animal use in liver research, Dr Huch said: "Typically a study to investigate one potential drug compound to treat one form of liver disease would require up to 50 live animals per experiment, so testing 1000 compounds would need 50,000 mice. By using the liver culture system I developed, we can test 1000 compounds using cells that come from only one mouse, resulting in a significant reduction in animal use. 

"If other laboratories adopt this method then the impact on animal use in the liver research field would be immediate. A vast library of potential drug compounds could be narrowed down to just one or two very quickly and cheaply, which can then be tested further in an animal study."

Dr Vicky Robinson, Chief Executive of the NC3Rs said: "Growing functioning liver cells in culture has been the Holy Grail for liver biologists for many years, so a limitless supply of hepatocytes could have a huge 3Rs impact both on basic research to understand liver disease and for the screening and safety testing of pharmaceuticals. Researchers need to utilise this alternative technology as soon as possible to ensure the benefits to animals and human health are fully realised."

Professor Kevin Shakesheff, Director of the UK Regenerative Medicine Hub in Acellular Materials, said: "The work of Dr Huch and team demonstrates how three-dimensional culture and molecular biology combine to open new possibilities in the regeneration of complex tissues. The liver is an excellent target for this work as the human body has an ability to regenerate liver tissue that is very hard to replicate in the lab. Unlocking new mechanisms to generate functional liver creates therapeutic approaches for patients with liver disease or injury and could offer a route to high quality human liver models that enhance drug development."

Two other research papers were highly-commended by this year's 3Rs Prize.

Dr Gyorgy Fejer, Plymouth University, was recognised for the development of a new method to grow macrophage cells for use in infectious disease research, which would reduce the use of mice by many thousands.

Also recognised is work by Dr Daniel Adams, University of California San Francisco, which takes inspiration from human orthopaedics to develop a biocompatible, titanium skull implant to reduce infection risk and improve welfare in monkeys undergoing cognition studies where brain activity is monitored directly.

Dr Malcolm Skingle CBE, Director of Academic Liaison at GlaxoSmithKline, which sponsors the 3Rs Prize, said: "This competition highlights some of the best international science to replace, reduce and refine the use of animals in research and GlaxoSmithKline is delighted to continue to sponsor this important award. Promoting innovative technologies and approaches to a global audience in this way can help improve their uptake and advance the global 3Rs agenda for better medicines and reduced animal use."
 

Contact NC3Rs Media Office:

Dan Richards-Doran, Communications Manager, NC3Rs. dan.richards-doran@nc3rs.org.uk 020 7611 2253, 07920 765897

Notes to Editors:

Winning paper reference:
Huch M, Dorrell C, Boj SF, van Es JH, Li VSW, van de Wetering M, Sato T, Hamer K, Sasaki N, Finegold MJ, Haft A, Vries RG, Grompe M, Clevers H (2013). In vitro expansion of single Lgr5+ liver stem cells induced by Wnt-driven regeneration. Nature 494: 247252.

Highly commended paper references:
Fejer G, Wegner MD, Györy I, Cohen I, Engelhard P, Voronov E, Manke T, Ruzsics Z, Dölken L, Prazeres da Costa O, Branzk N, Huber M, Prasse A, Schneider R, Apte RN, Galanos C, Freudenberg M (2013). Nontransformed, GM-CSFdependent macrophage lines are a unique model to study tissue macrophage functions. PNAS 110(24): E2191-E2198.

Adams DL, Economides JR, Jocson CM, ParkerJM, Horton JC (2011). A watertight acrylic-free titanium recording chamber for electrophysiology in behaving monkeys. J. Neurophysiol 106: 15811590.

About the NC3Rs 3Rs Prize
The NC3Rs awards an annual prize for an original contribution to scientific and technological advances in the 3Rs (replacement, reduction and refinement of animal use) in medical, biological or veterinary sciences published within the last three years. Sponsored by GlaxoSmithKline, the prize consists of a prize grant of £18k, plus a personal award of £2k, and is part of the NC3Rs' commitment to recognise and reward high quality research that has an impact on the use of animals in the life sciences. Highly-commended prizes consist of a grant of £4k, plus a personal award of £1k.

About the NC3Rs
The National Centre for the Replacement, Refinement and Reduction of Animals in Research (NC3Rs) leads discovery and application of new technologies and approaches to minimise the use of animals and improve animal welfare (the 3Rs). It funds research, supports training and development, and stimulates changes in regulations and practice. Primarily funded by Government, the NC3Rs is also supported by the charitable and private sectors. It works with scientists in universities and industry in the UK and internationally. Further information can be found at: www.nc3rs.org.uk | @nc3rs |http://blog.nc3rs.org.uk  

About GlaxoSmithKline
GlaxoSmithKline one of the world's leading research-based pharmaceutical and healthcare companies is committed to improving the quality of human life by enabling people to do more, feel better and live longer. For more information go to www.gsk.com