Navigation Links
How to make stem cells - nuclear reprogramming moves a step forward
Date:10/28/2012

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."


'/>"/>
Contact: Hilary Glover
hilary.glover@biomedcentral.com
44-020-319-22370
BioMed Central
Source:Eurekalert

Related biology news :

1. Watching the cogwheels of the biological clock in living cells
2. A new technique to study how myeloids become white blood cells
3. Danish researchers release ground-breaking knowledge about calcium pumps in cells
4. Moderate drinking decreases number of new brain cells
5. Professor publishes on first-ever imaging of cells growing on spherical surfaces
6. Pollen cells keep memory to control jumping genes
7. Precision motion tracking -- thousands of cells at a time
8. Study in mice discovers injection of heat-generating cells reduces belly fat
9. UCLA researchers discover missing link between stem cells and immune system
10. Keep your distance! Why cells and organelles dont get stuck
11. A new look at proteins in living cells
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:5/16/2017)... 16, 2017   Bridge Patient Portal , ... MD EMR Systems , an electronic medical ... GE, have established a partnership to build an ... the GE Centricity™ products, including Centricity Practice Solution ... These new integrations will allow healthcare delivery ...
(Date:4/24/2017)... WASHINGTON , April 24, 2017 ... counsel and partner with  Identity Strategy Partners, LLP ... "With or without President Trump,s March 6, ... Foreign Terrorist Entry , refugee vetting can be instilled ... refugee resettlement. (Right now, all refugee applications are ...
(Date:4/18/2017)...  Socionext Inc., a global expert in SoC-based imaging and computing ... M820, which features the company,s hybrid codec technology. A demonstration utilizing ... Inc., will be showcased during the upcoming Medtec Japan at Tokyo ... Las Vegas Convention Center April 24-27. ... Click here for an image ...
Breaking Biology News(10 mins):
(Date:10/12/2017)... , ... October 12, 2017 ... ... has launched Rosalind™, the first-ever genomics analysis platform specifically designed for life ... Named in honor of pioneering researcher Rosalind Franklin, who made a major ...
(Date:10/11/2017)... (PRWEB) , ... October 11, 2017 , ... ComplianceOnline’s Medical ... place on 7th and 8th June 2018 in San Francisco, CA. The Summit brings ... well as several distinguished CEOs, board directors and government officials from around the world ...
(Date:10/11/2017)... Tbilisi, Georgia (PRWEB) , ... October 11, 2017 , ... ... disaster, taking the lives of over 5.5 million people each year. Especially those living ... the greenovative startup Treepex - based in one of the most pollution-affected countries globally ...
(Date:10/10/2017)... (PRWEB) , ... October 10, ... ... development-stage cancer-focused pharmaceutical company advancing targeted antibody-drug conjugate (ADC) therapeutics, today confirmed ... targeted HPLN (Hybrid Polymerized Liposomal Nanoparticle), a technology developed in collaboration with ...
Breaking Biology Technology: