Featured Research

from universities, journals, and other organizations

Researchers find molecular switch turning on self-renewal of liver damage

Date:
March 7, 2013
Source:
University of Copenhagen
Summary:
The liver is one of the few organs in our body that can regenerate itself, but how it occurs is a biological mystery. New research from Denmark has identified a protein complex that act to switch on a self-regeneration program in the liver.

The liver is one of the few organs in our body that can regenerate itself, but how it occurs is a biological mystery. New research from BRIC, University of Copenhagen and the Finsen Laboratory, Rigshospitalet, has identified a protein complex that acts as a molecular switch turning on a self-regeneration program in the liver. The protein complex furthermore fine tunes liver metabolism, allowing this to run efficiently in parallel with the tissue damage repair. The new knowledge challenges the current focus on stem cells and may point towards future simplification of treatments used for repairing tissue damage.

Related Articles


"Our new data challenge the predominant 'stem cell-mania' as the results reveal important molecular mechanisms that enable ordinary liver cells to divide and repair tissue damage. This may point to ways of using ordinary liver cells for therapeutic purposes, as these cells may be easier to use than stem cells," says Head of Clinic and Professor Bo Porse who has lead the investigation.

Protein complex turn on self-renewal genes

When the specialised cell types of our body are formed from stem cells during development, they generally lose the ability to divide and make new cells. Tissue renewal is therefore a job for the stem cells present in our body. One exception is the specialised cells of the liver called hepatocytes. They are responsible for the metabolic functions of the liver, but can at the same time produce new liver cells. How that is possible is a bit of a mystery.

"Our results show how a protein complex is changed upon damage to the liver, making it function as a 'switch' turning on a self-renewal program in the hepatocytes. The protein complex literally turns on selected genes that enable division of the hepatocytes, while maintaining their metabolic functions," says postdoc Janus Schou Jakobsen, who has lead the experimental part of the investigation.

The extraordinary ability of the liver cells to divide almost indefinitely resembles the ability of stem cells to self-renew and this finding challenges the current focus on stem cells and stem cell therapy.

Self-renewal programs in non-stem cells

The new results from Bo Porse's research group are consistent with new studies of self-renewal in the group of white blood cells called macrophages.

"We see a clear overlap in the molecular mechanisms controlling self-renewal in hepatocytes and macrophages and that could indicate the existence of a more general self-renewal program used by specialised cell types. If this is the case, it can really change the current perception that only stem cells are responsible for renewal of our tissues," says Janus Schou Jakobsen.

The study addresses basic research questions, but if it can be shown that one can turn on and off specific sets of genes, making many types of specialised cells divide, it can have great impact on future regenerative treatments. It is very likely easier to make a specialised cell copy itself, than to extract the very scarce stem cells and accurately reprogram them to the specialised cell type of need.

Self-renewal and cancer development

The research in Bo Porse's laboratory focusses both on tissue renewal and on how mistakes in the genetic control mechanisms can give rise to cancer.

"Currently, so-called cancer stem cells receive much attention -- these are single cancer cells that are difficult to kill. They have taken over stem cell programs enabling them to divide uncontrolled and to reform an entire tumour. It is likely that cancer cells can also hijack the self-renewal programs we have identified in liver cells. Increased knowledge on these self-renewal programs may therefore lead to a new understanding of cancer cell biology and open up for new treatment strategies," says Bo Porse.

The next step for the researchers is to dig deeper in the molecular understanding of how self-renewal systems can be turned on and off in specialised cell types.

Original paper: The results have been published as advance online publication by the journal Genome Research and the final version will appear late March/early April. Jakobsen et al: Temporal mapping of CEBPA and CEBPB binding during liver regeneration reveals dynamic occupancy and specific regulatory codes for homeostatic and cell cycle gene batteries.

Research support: The research has been supported by the Novo Nordisk Foundation and the Danish Cancer Society.


Story Source:

The above story is based on materials provided by University of Copenhagen. Note: Materials may be edited for content and length.


Cite This Page:

University of Copenhagen. "Researchers find molecular switch turning on self-renewal of liver damage." ScienceDaily. ScienceDaily, 7 March 2013. <www.sciencedaily.com/releases/2013/03/130307124545.htm>.
University of Copenhagen. (2013, March 7). Researchers find molecular switch turning on self-renewal of liver damage. ScienceDaily. Retrieved November 23, 2014 from www.sciencedaily.com/releases/2013/03/130307124545.htm
University of Copenhagen. "Researchers find molecular switch turning on self-renewal of liver damage." ScienceDaily. www.sciencedaily.com/releases/2013/03/130307124545.htm (accessed November 23, 2014).

Share This


More From ScienceDaily



More Health & Medicine News

Sunday, November 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Ebola-Hit Sierra Leone's Late Cocoa Leaves Bitter Taste

Ebola-Hit Sierra Leone's Late Cocoa Leaves Bitter Taste

AFP (Nov. 23, 2014) The arable district of Kenema in Sierra Leone -- at the centre of the Ebola outbreak in May -- has been under quarantine for three months as the cocoa harvest comes in. Duration: 01:32 Video provided by AFP
Powered by NewsLook.com
Don't Fall For Flu Shot Myths

Don't Fall For Flu Shot Myths

Newsy (Nov. 23, 2014) Misconceptions abound when it comes to your annual flu shot. Medical experts say most people older than 6 months should get the shot. Video provided by Newsy
Powered by NewsLook.com
WFP: Ebola Risks Heightened Among Women Throughout Africa

WFP: Ebola Risks Heightened Among Women Throughout Africa

AFP (Nov. 21, 2014) Having children has always been a frightening prospect in Sierra Leone, the world's most dangerous place to give birth, but Ebola has presented an alarming new threat for expectant mothers. Duration: 00:37 Video provided by AFP
Powered by NewsLook.com
Could Your Genes Be The Reason You're Single?

Could Your Genes Be The Reason You're Single?

Newsy (Nov. 21, 2014) Researchers in Beijing discovered a gene called 5-HTA1, and carriers are reportedly 20 percent more likely to be single. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins