Australian scientists have discovered a new cell in the liver of mice that works like a "watchman" to protect the organ from infection and potentially even scarring.
The "important" discovery made at the Centenary Institute of Cancer Medicine and Cell Biology, published in journal Immunity, has raised hopes of new treatments to prevent liver failure and even cancer.
Although this is still a long way off, the authors note.
"These cells act like sentinels; they display arm-like features able to sense dangerous pathogens or microbes in their environment. When harmful microbes are detected, the same cell recruits an army of whte blood cells that destroy the invaders before they cross the liver outer membrane and disseminate in the body," said Associate Professor David Bowen.
Approximately 20 Australians die from liver disease each day, with liver cancer the fastest growing cause of cancer death in Australia.
Poor liver health is a growing problem, driven by high rates of obesity, and improving the understanding of the organ's biology is very important, Assoc Prof Bowen said.
"Liver disease is becoming a huge problem.
"People who are obese can tend to get liver scarring and we now have well over a third of our population are obese; we are actually starting to see an explosion of (overweight) people coming to us with liver cancer and that is being driven by fat in their liver."
Using a fluorescence imaging technique known as two-photon excitation microscopy - that allows imaging of living tissue up to about one millimetre in depth - researchers analysed liver tissue samples of mice.
The analysis found a never-before identified cell that works to protect the liver against infection from all the bacteria that drains from the bowel.
They suspect this cell could also be protective in terms of scarring - damage which eventually results in organ failure and death.
"With each heartbeat, a fifth of our blood goes through the liver, so gut bugs can be carried into the body via the liver. This is why the liver's ability to fight disease is vitally important," explained Prof Bowen.
"Before pasteurisation one of the major problems people had was getting tuberculosis from infected cows from what they drank," he said.
Preventing scarring would essentially reduce death from liver failure anor cancer, says Prof Bowen.
"As far as liver cancer is concerned it usually occurs in someone who has advanced scarring, so if we could prevent scarring in the first place we can actually prevent the majority of liver cancers, obviously I would admit we are a well off that but this at the moment is a hint," he said.
Co-author Associate Professor Patrick Bertolino is hopeful the discovery will lead to the development of better treatments for patients.
"Now that this cell has been discovered, further tests need to be carried out to fully understand the role and how it can be targeted," Prof Bertolino said.
