Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

How to make stem cells – nuclear reprogramming moves a step forward

29.10.2012
The idea of taking a mature cell and removing its identity (nuclear reprogramming) so that it can then become any kind of cell, holds great promise for repairing damaged tissue or replacing bone marrow after chemotherapy.

Hot on the heels of his recent Nobel prize Dr John B. Gurdon has published today in BioMed Central's open access journal Epigenetics & Chromatin research showing that histone H3.3 deposited by the histone-interacting protein HIRA is a key step in reverting nuclei to a pluripotent type, capable of being any one of many cell types.

All of an individual's cells have the same DNA, yet these cells become programmed, as the organism matures, into different types such as heart, or lung or brain. To achieve this different genes are more or less permanently switched off in each cell lineage. As an embryo grows, after a certain number of divisions, it is no longer possible for cells which have gone down the pathway to become something else. For example heart cells cannot be converted into lung tissue, and muscle cells cannot form bone.

One way to reprogram DNA is to transfer the nucleus of a mature cell into an unfertilized egg. Proteins and other factors inside the egg alter the DNA switching some genes on and other off until it resembles the DNA of a pluripotent cell. However there seem to be some difficulties with this method in completely wiping the cell's 'memory'.

One of the mechanisms regulating the activation of genes is chromatin and in particular histones. DNA is wrapped around histones and alteration in how the DNA is wound changes which genes are available to the cell. In order to understand how nuclear reprogramming works Dr Gurdon's team transplanted a mouse nucleus into a frog oocyte (Xenopus laevis). They added fluorescently tagged histones by microinjection, so that they could see where in the cell and nucleus the these histones collected.

Prof Gurdon explained, "Using real-time microscopy it became apparent that from 10 hours onwards H3.3 (the histone involved with active genes) expressed in the oocyte became incorporated into the transplanted nucleus. When we looked in detail at the gene Oct4, which is known to be involved in making cells pluripotent, we found that H3.3 was incorporated into Oct4, and that this coincided with the onset of transcription from the gene." Prof Gurdon's team also found that Hira, a protein required to incorporate H3.3 into chromatin, was also required for nuclear reprogramming.

Dr Steven Henikoff, from the Fred Hutchinson Cancer Research Center, commented, "Manipulating the H3.3 pathway may provide a way to completely wipe a cell's 'memory' and produce a truly pluripotent cell. Half a century after showing that cells can be reprogrammed this research provides a link to the work of Shinya Yamanaka (who shared the prize), and suggests that chromatin is a sticking point preventing artificially induced reprogramming being used routinely in the clinic."

Media contact

Dr Hilary Glover
Scientific Press Officer, BioMed Central
Tel: +44 (0) 20 3192 2370
Mob: +44 (0) 778 698 1967
Email: hilary.glover@biomedcentral.com
Notes
1. HIRA dependent H3.3 deposition is required for transcriptional reprogramming following nuclear transfer to Xenopus oocytes jerome jullien, carolina astrand, emmanuelle szenker, nigel garrett, genevieve almouzni and john gurdon Epigenetics & Chromatin (in press)
Chromatin roadblocks to reprogramming 50 years on
Peter J Skene and Steven Henikoff
BMC Biology (in press)
Please name the journal in any story you write. If you are writing for the web, please link to the article. All articles are available free of charge, according to BioMed Central's open access policy.

Article citation and URL available on request on the day of publication.

2. Epigenetics & Chromatin is a peer-reviewed, open access, online journal, which publishes articles that provide novel insights into epigenetic inheritance and chromatin-based interactions. @EpigenChromatin

3. BioMed Central (http://www.biomedcentral.com/) is an STM (Science, Technology and Medicine) publisher which has pioneered the open access publishing model. All peer-reviewed research articles published by BioMed Central are made immediately and freely accessible online, and are licensed to allow redistribution and reuse. BioMed Central is part of Springer Science+Business Media, a leading global publisher in the STM sector. @BioMedCentral

Hilary Glover | EurekAlert!
Further information:
http://www.biomedcentral.com

Further reports about: BioMed Chromatin DNA Epigenetics HIRA STM Xenopus Laevis tadpoles cell type

More articles from Life Sciences:

nachricht The birth of a new protein
20.10.2017 | University of Arizona

nachricht Building New Moss Factories
20.10.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Terahertz spectroscopy goes nano

20.10.2017 | Information Technology

Strange but true: Turning a material upside down can sometimes make it softer

20.10.2017 | Materials Sciences

NRL clarifies valley polarization for electronic and optoelectronic technologies

20.10.2017 | Interdisciplinary Research

VideoLinks
B2B-VideoLinks
More VideoLinks >>>