- Michigan-based startup RetroSense Therapeutics will begin the first human trial of optogenetics next month, in a study aimed at treating a degenerative eye disease with a new gene therapy.
- The trial will involve up to 15 patients with retinitis pigmentosa, which causes photoreceptor cells in the eye to progressively die off and eventually leads to blindness.
- Retrosense's technology implants the DNA of a light-sensitive algae into cells on the outside of the retina, hopefully causing those cells to respond to light and send visual signals to the brain.
This novel gene therapy draws from the field of optogenetics. Originally developed in neuroscience labs, optogenetics involves inserting the DNA of a light-sensitive protein, channelrhodopsin, into nerve cells. Originally found in algae, the protein responds to a specific blue wavelength of light.
Inserting it into nerve cells causes those cells to fire when exposed to that particular light. This has broad implications for understanding how nerve cells transmit signals, and which nerve cells control certain functions.
Spun out of research done by Zhuo-Hua Pan at Wayne State University, RetroSense took the principles of optogenetics and applied it to treating blindness. The upcoming study will target nerve cells on the outside of the retina called ganglions. Following treatment, those cells should respond to blue light and lead to limited vision in patients.
Based on previous studies done in mice, researchers expect any restored vision would be monochromatic and likely limited to bright settings, such as the outdoors. RetroSense won clearance from the FDA back in August 2015 to conduct human trials for its treatment, called RST-001.
Optogenetics more broadly could be instrumental in furthering science's understanding of brain function. By inserting the light sensitive protein into other nerve cells, scientists can switch brain cells on and off by targeting them with light. Working on the eye has a clear advantage, however, as the cells Retrosense wants to target are naturally exposed to light. Other research interested in using optogenetics to develop treatments for brain diseases will have to rely on methods such as implanting fiber-optic wires in the brain.