Scientists have developed new tools for photogenetics to help blind mice "review the sky"

A team of Swiss and German scientists has recently developed a new optical genetics tool that allows mice that are blinded by photoreceptor cells to better restore daytime vision. This research has taken a major step forward in the clinical application of photogenetic technology for blindness. Related papers were published in the journal Public Library of Science and Biology.

Hereditary blindness is caused by the gradual degradation of photoreceptor cells in the eye, affecting millions of people around the world. Although the photoreceptor cells are damaged, the cells in the deep layers of the retina are still intact, and the deep cells are usually not sensitive. The new tool's therapies are based on photogenetic technology that introduces photoreceptors into surviving deep retinal cells and turns them into “replacement photoreceptors” to restore vision.

The author of the paper, Sonia Crayon Roger of the University of Bern, Switzerland, said that the idea of ​​the new tool is to design a photo-activated protein as a gate, allowing special signals to enter special cells. That is, to preserve the natural signal path of the target cell, just modify it so that it can be opened by light without the need for neurotransmitters released by the front neurons.

To this end, the researchers produced a chimeric photoreceptor protein called "Opto-mGluR6", a photoreceptor region of melanopsin (retina photoreceptor) and an ON-bipolar cell metabotropic glutamate receptor (mGluR6). spell. The "optical antenna" of melanopsin can resist fading. No matter how high the frequency of light irradiation and the intensity, the reaction intensity of chimeric protein will not be weakened. mGluR6 is a chemical receptor that, when turned into a photoactivated receptor, guarantees high photosensitivity and rapid "normal" responsiveness. Moreover, since Opto-mGluR6 is composed of two autologous retinal proteins, it may also be "released" by the immune system.

Studies have shown that mice with retinitis pigmentosa are treated to restore daytime vision. Klein Roger said: "For patients with photoreceptor degenerative eye disease, new treatments are expected to bring them back to light, such as those with severe age-related macular degeneration, which is common in people over 65 years old, about 1/ 10 people are affected to varying degrees.” Compared with the original therapy, the main advancement of the new therapy is that the patient can see the object under normal daylight conditions without the need for strong light or image conversion to the eyepiece.

For those with ocular photoreceptor degeneration, like a digital camera that slowly loses pixels, not only does it gradually lose its light, but it also suffers tremendously. This new study is like re-opening the ion channel and activating retinal cells when the mouse's optical switch senses light, thus restoring the photosensitivity of blind mice. This treatment may also help blind people recover some of them in the future. Sensitivity, this news is enough to make patients with photoreceptor degenerative eye disease full of confidence, with the advancement of technology, they may be able to see the light again in the future. It’s just that there is still a long way to go before new therapeutic applications are applied to humans.