Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

The role of stem cells in renewing the cornea

02.10.2008
A group of researchers in Lausanne, Switzerland has published a study appearing in the Oct 1 advance online edition of the Journal Nature that shows how the cornea uses stem cells to repair itself.

Using mouse models they demonstrate that everyday wear and tear on the cornea is repaired from stem cells residing in the corneal epithelium, and that more serious repair jobs require the involvement of other stem cells that migrate from the limbus, a region between the cornea and the conjunctiva, the white part of the eye.

The integrity of the cornea, the transparent outer layer of the eye, is critical for vision. Millions of people around the world suffer from partial or complete blindness when their corneas lose transparency. Treatment options involve corneal transplants and, more recently, stem cell therapy. The surface of the cornea is naturally in a state of constant renewal; its upper layer, or epithelium, is completely turned over once every 7-14 days. Because slow-cycling stem cells have been found in the mouse limbus, researchers have assumed that these stem cells are the ones responsible for corneal renewal.

The research led by Professor Yann Barrandon, who holds a joint appointment at EPFL and the Lausanne University Hospitals (CHUV), challenges this prevailing opinion that the limbus is the only place where corneal stem cells reside. The researchers demonstrated that the epithelium of the cornea also contains stem cells, and that these cells have the capacity to generate two different epithelial tissues: corneal (covering the transparent part of the eye) and conjunctival (covering the white part of the eye). They demonstrated experimentally that these are the cells activated in everyday corneal renewal. The stem cells residing in the limbus have a different role; they are only activated when the cornea is seriously wounded.

To explain this distribution of stem cells and the different roles played by stem cells in different zones of the eye, the researchers propose that the expanding epithelia of the cornea and the conjunctiva act like tectonic plates, squeezing the limbus between them into a kind of equilibrium zone. Due to the constant expansion, stem cells accumulate in this zone. In the event of a rupture in the equilibrium, such as a large corneal injury, these limbal stem cells migrate into the cornea and conjunctiva and differentiate into the appropriate cell type to make repairs.

The limbus is already recognized as a source of cells for corneal stem cell therapy in humans, and this new research indicates that the cornea itself can also be explored as a potential source of these cells. And because cancer has been associated with the presence of adult stem cells, the model also helps explain why transitional zones like the limbus, where stem cells accumulate, are sites where cancer tends to occur more frequently.

Contact: Yann Barrandon, yann.barrandon@epfl.ch, phone +41 79 598 65 21

Mary Parlange | alfa
Further information:
http://www.epfl.ch
http://www.nature.com/nature/journal/vaop/ncurrent/abs/nature07406.html

More articles from Studies and Analyses:

nachricht New study: How does Europe become a leading player for software and IT services?
03.04.2017 | Fraunhofer-Institut für System- und Innovationsforschung (ISI)

nachricht Reusable carbon nanotubes could be the water filter of the future, says RIT study
30.03.2017 | Rochester Institute of Technology

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

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

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

Im Focus: Using graphene to create quantum bits

In the race to produce a quantum computer, a number of projects are seeking a way to create quantum bits -- or qubits -- that are stable, meaning they are not much affected by changes in their environment. This normally needs highly nonlinear non-dissipative elements capable of functioning at very low temperatures.

In pursuit of this goal, researchers at EPFL's Laboratory of Photonics and Quantum Measurements LPQM (STI/SB), have investigated a nonlinear graphene-based...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

Physicists discover mechanism behind granular capillary effect

24.05.2017 | Physics and Astronomy

Measured for the first time: Direction of light waves changed by quantum effect

24.05.2017 | Physics and Astronomy

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>