Algae may be the solution to blindness

by Deborah Braconnier report

(PhysOrg.com) -- The song about three blind mice may just be a song of the past according to new research presented by neuroscientist Alan Horsager from the Institute of Genetic Medicine at the University of Southern California with the report set to appear in Molecular Therapy. Using genes from algae injected into the retina, Horsager hopes this research will lead to a treatment for some forms of blindness.

Over 15 million people suffer from some form of , with the most common conditions being retinitis pigmentosa (RP) and age-related (AMD). Both of these conditions are caused when the photoreceptors in the eye are damaged. The photoreceptors are responsible for transforming light entering the eye into electrical impulses, but when damaged, the brain is unable to receive this information.

Horsager’s team is working with gene therapy and the gene responsible for making Channelrhodopsin-2 (ChR2) in algae. This photosensitive protein in the algae is what helps direct them toward a source of light.

The of the human eye is made up of three cellular layers. The first layer is the photoreceptors, which is what is damaged in people with RP and AMD. The second layer of the retina is made of bipolar cells which work to transmit information between the photoreceptors and the third layer, the ganglion. The ganglion is what then transmits light signals to the brain.

Horsager’s plan is to use the bipolar cells and make them work as as well. By injecting the gene into the bipolar cells, the idea is to have them produce the ChR2 and operate as a photoreceptor. With the bipolar cells able to sense light, they would then be able to transmit this information to the ganglion, which would then in turn transmit it to the .

The teams tested this on groups of mice and found that ten weeks after the injection of the , the bipolar cells were producing the ChR2 protein. They then put the mice in a maze of water with six possible paths with one having a ledge for the mice to get out of the water. Shining a light through the pass with the ledge, the gene-treated mice were able to find the path 2.5 times faster than the untreated blind mice.

The team is continuing its research and hopes to begin clinical trials in humans within the next two years.

More information: Doroudchi, M.M., Greenberg, K.P, Liu, J., Silka, K.A., Boyden, E.S., Lockridge, J.A., Arman, A.C., Janani, R., Boye, S.E., Boye, S.L., Gordon, G.M., Matteo, B.C., Sampath, A.P., Hauswirth, W.W., Horsager, A. “Virally-Delivered Channelrhodopsin-2 Safely and Effectively Restores Visual Function in Multiple Models of Blindness”. (Accepted, Molecular Therapy).

Related Stories

Scientists successfully awaken sleeping stem cells

Mar 18, 2008

Scientists at Schepens Eye Research Institute have discovered what chemical in the eye triggers the dormant capacity of certain non-neuronal cells to transform into progenitor cells, a stem-like cell that can generate new ...

Sight recovery in mice

Jun 24, 2010

Swiss researchers from the Friedrich Miescher Institute, in collaboration with Inserm researchers from CNRS and UPMC in the Institut de la Vision, have restored sight to mice afflicted with retinitis pigmentosa. The results ...

The difference between eye cells is... sumo?

Mar 09, 2009

Researchers at the Johns Hopkins University School of Medicine and Washington University School of Medicine have identified a key to eye development — a protein that regulates how the light-sensing nerve cells in the retina ...

Recommended for you

Diet affects men's and women's gut microbes differently

22 hours ago

The microbes living in the guts of males and females react differently to diet, even when the diets are identical, according to a study by scientists from The University of Texas at Austin and six other institutions published ...

User comments

Adjust slider to filter visible comments by rank

Display comments: newest first

mjesfahani
not rated yet Apr 16, 2011
Excellent research. it'll have excellent results on our lives:)