Algae genes could restore vision in blind people
Blind people could get their vision back in near future, thanks to the results of a new study that has found a link between algae and vision. A team of researchers led by Alan Horsager from the Institute of Genetic Medicine at the University of South California (USA) had injected a group of previously blind mice with algal genes. Researchers used a ‘tamed’ virus to transport this gene to the receptor cells in the retina of the mice, where the algal genes stimulated production of photosensitive proteins. The technique has succeeded in restoring the ability to sense light and dark to blind mice.
In this experiment the researchers put the previously blind mice in a maze and the mice was unable to come out of the maze as it was not capable of finding the lever that needs to be pressed to come out of the maze. Once the mice were injected with the algal genes, previously blind mice eventually managed to come out of the trap by orienting themselves according to a beam of light shining directly on the lever.
The experiment clearly showed that the mice was able to detect and follow the light. This is a remarkable result having far reach implications in the treatment of blindness.
How it works
The treatment uses algal genes to repair defective light receptors in the retina. They use a ‘tame’ virus to transfer the genes to the target cells. The gene of interest is one that makes Channelrhodopsin-2 (ChR2), a photosensitive protein used by unicellular algae to help them move towards light. The target cells are bipolar cells in the retina.
Retina contains rods and cones (photo receptors), bipolar cells and the ganglions that transmit the sensation of light to the brain. People suffering from retinitis pigmentosa or macular degeneration has their photo receptors , rods and cones damaged beyond repair, preventing the brain from sensing the light, leading to blindness. The rods and cones are the only cells in the retina that has the capability to detect light. Bipolar cells acts as the mediator between the rods and cones and the ganglion which transmits the light to the brain.
The new technique involves using gene therapy to modify the bipolar cells to produce the protein Channelrhodopsin-2 (ChR2), with this protein the bipolar cells will be able to detect light and can mimic what the rods and cones does. This information from the bipolar cells will find its way to the brain via the ganglion.
“The idea is to develop a treatment for blindness,” says Alan Horsager, a neuroscientist at the Institute of Genetic Medicine at the University of Southern California, Los Angeles, who leads the research. Researchers are hopeful that they can start clinical trials on blind people with macular degeneration and similar eye conditions in the 2 years. ”Our expectation is that this would be a one-time treatment that is permanent or semi-permanent,” says Horsager.
It is too early to say how much their vision will improve at this stage. Researchers are hopeful that they will find the same kind of results achieved with their experiments on mice. One day this technique could offer a new life and a colorful world to the millions of people suffering from blindness caused by macular degeneration and similar conditions.