Navigation Links
The role of stem cells in renewing the cornea
Date:10/2/2008

A group of researchers in 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
41-795-986-521
Ecole Polytechnique Fdrale de Lausanne
Source:Eurekalert

Related biology news :

1. ESF EURYI award winner aims to stop cancer cells reading their own DNA
2. Newly created cancer stem cells could aid breast cancer research
3. AIDS interferes with stem cells in the brain
4. Clemson scientists shed light on molecules in living cells
5. Social habits of cells may hold key to fighting diseases
6. UF scientists reveal how dietary restriction cleans cells
7. Human derived stem cells can repair rat hearts damaged by heart attack
8. Scientists identify embryonic stem cells by appearance alone
9. Cells united against cancer
10. Pittsburgh scientists identify human source of stem cells with potential to repair muscle
11. U of M begins nations first clinical trial using T-reg cells from cord blood in leukemia treatment
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:5/6/2017)... 2017 RAM Group , Singaporean ... breakthrough in biometric authentication based on a ... to perform biometric authentication. These new sensors are based ... by Ram Group and its partners. This sensor will ... chains and security. Ram Group is a next ...
(Date:4/18/2017)... SUNNYVALE, Calif. , April 18, 2017  Socionext Inc., a ... prototype of a media edge server, the M820, which features the ... face recognition software provided by Tera Probe, Inc., will be showcased ... and at the NAB show at the Las Vegas ... ...
(Date:4/13/2017)... , April 13, 2017 According to a ... Identity Authentication, Identity Analytics, Identity Administration, and Authorization), Service, Authentication Type, Deployment ... the IAM Market is expected to grow from USD 14.30 Billion in ... Rate (CAGR) of 17.3%. ... MarketsandMarkets Logo ...
Breaking Biology News(10 mins):
(Date:10/11/2017)... a leading provider of patient support solutions, has announced the ... which will launch this week. The VMS CNEs will address ... enhance the patient care experience by delivering peer-to-peer education programs ... to help women who have been diagnosed and are being ... ...
(Date:10/11/2017)... ... October 11, 2017 , ... Disappearing forests and increased emissions are the main ... people each year. Especially those living in larger cities are affected by air pollution ... of the most pollution-affected countries globally - decided to take action. , “I knew ...
(Date:10/11/2017)... Bay, Florida (PRWEB) , ... October 11, 2017 ... ... and Drug Administration (FDA) has granted orphan drug designation to SBT-100, its novel ... (sdAb) for the treatment of osteosarcoma. SBT-100 is able to cross the cell ...
(Date:10/10/2017)... , ... October 10, 2017 ... ... cancer-focused pharmaceutical company advancing targeted antibody-drug conjugate (ADC) therapeutics, today confirmed licensing ... HPLN (Hybrid Polymerized Liposomal Nanoparticle), a technology developed in collaboration with Children’s ...
Breaking Biology Technology: