Specific protein essential for healthy eyes, study finds

January 7, 2013, Hebrew University of Jerusalem

Researchers at the Hebrew University of Jerusalem, in collaboration with researchers at the Salk Institute in California, have found for the first time that a specific protein is essential not only for maintaining a healthy retina in the eye, but also may have implications for understanding and possibly treating other conditions in the immune, reproductive, vascular and nervous systems, as well as in various cancers.

Their work, reported online in the journal Neuron, highlights the role of Protein S in the maintenance of a healthy retina through its involvement in the process of pruning photoreceptors, the light- in the eye. (This process is also referred to as phagocytosis.) These photoreceptors keep growing and elongating from their inner end. In order to maintain a constant length, they must be pruned from their outer end by specialized cells called epithelial cells.

Without such pruning—which also clears away many and toxic by-products generated during visual —photoreceptors would succumb to toxicity and degenerate, leading if unchecked to blindness. A called Mer is a key in photoreceptor pruning, and is therefore vital for retinal health. Mutations in the mouse, rat and human Mer genes cause , which finally leads to blindness.

The Hebrew University study published in Neuron focuses on the molecules activating Mer in this pruning mechanism. Although two such molecules – Gas6 and Protein S—were identified previously, it was yet to be proven that they also play a role in a . To show this, Dr. Tal Burstyn-Cohen of the Hebrew University Institute of Dental Sciences and colleagues at the Salk Institute in California found in their experiments on laboratory animals that both Gas6 and Protein S are needed to activate phagocytosis, or pruning, of retinal photoreceptors, and thus keep a healthy retina.

These findings could have practical implications, since Protein S also functions as a potent blood anticoagulant. People with Protein S deficiency are at risk for life threatening thrombosis (blood clots) and thromboembolism (a clot that breaks loose and is carried by the blood stream to plug another vessel).

These results further open new avenues of research into the role of Protein S in activating the receptors in other tissues where their function was shown to be important, such as in the immune, reproductive, vascular and nervous systems, as well as in various cancers where activation of receptors has been observed. For example, since Protein S is important for blood vessel formation, neutralizing Protein S in the blood vessels supplying blood to cancer growths could interfere with the cancerous blood supply.

Explore further: New molecular pathway regulating angiogenesis may fight retinal disease, cancers

More information: Burstyn-Cohen, T. et al., Genetic Dissection of TAM Receptor-Ligand Interaction in Retinal Pigment Epithelial Cell Phagocytosis. Neuron. 20 December 2012, 76(6) pp. 1123 - 1132.

Related Stories

New molecular pathway regulating angiogenesis may fight retinal disease, cancers

May 29, 2011
Scientists identify in the journal Nature a new molecular pathway used to suppress blood vessel branching in the developing retina – a finding with potential therapeutic value for fighting diseases of the retina and ...

Research on blood vessel proteins holds promise for controlling 'blood-brain barrier'

December 6, 2012
Working with mice, Johns Hopkins researchers have shed light on the activity of a protein pair found in cells that form the walls of blood vessels in the brain and retina, experiments that could lead to therapeutic control ...

Scientists unravel the cause of rare genetic disease: Goldman-Favre Syndrome explained

August 31, 2011
A new research report published in The FASEB Journal will help ophthalmologists and scientists better understand a rare genetic disease that causes increased susceptibility to blue light, night blindness, and decreased vision ...

Recommended for you

Research reveals atomic-level changes in ALS-linked protein

January 18, 2018
For the first time, researchers have described atom-by-atom changes in a family of proteins linked to amyotrophic lateral sclerosis (ALS), a group of brain disorders known as frontotemporal dementia and degenerative diseases ...

Fragile X finding shows normal neurons that interact poorly

January 18, 2018
Neurons in mice afflicted with the genetic defect that causes Fragile X syndrome (FXS) appear similar to those in healthy mice, but these neurons fail to interact normally, resulting in the long-known cognitive impairments, ...

How your brain remembers what you had for dinner last night

January 17, 2018
Confirming earlier computational models, researchers at University of California San Diego and UC San Diego School of Medicine, with colleagues in Arizona and Louisiana, report that episodic memories are encoded in the hippocampus ...

Recording a thought's fleeting trip through the brain

January 17, 2018
University of California, Berkeley neuroscientists have tracked the progress of a thought through the brain, showing clearly how the prefrontal cortex at the front of the brain coordinates activity to help us act in response ...

Midbrain 'start neurons' control whether we walk or run

January 17, 2018
Locomotion comprises the most fundamental movements we perform. It is a complex sequence from initiating the first step, to stopping when we reach our goal. At the same time, locomotion is executed at different speeds to ...

Miles Davis is not Mozart: The brains of jazz and classical pianists work differently

January 16, 2018
Keith Jarret, world-famous jazz pianist, once answered in an interview when asked if he would ever be interested in doing a concert where he would play both jazz and classical music: "No, that's hilarious. [...] It's like ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.