Multi-characteristic opsin (MCO) (MCO)

Multi-characteristic opsin (MCO) is a synthetic, ambient-light-sensitive optogenetic protein designed to restore vision in patients with advanced retinal degenerative diseases (Nanoscope Therapeutics, 2024). In conditions such as Retinitis Pigmentosa and Stargardt disease, the primary photoreceptors (rods and cones) are lost, but the downstream retinal architecture, including bipolar cells, often remains functional. By using an adeno-associated virus (AAV2) vector to deliver the MCO gene specifically to these retinal bipolar cells, the cells are converted into primary photosensors (Batabyal et al., 2021). MCO is engineered to be highly sensitive to light across a broad spectrum, allowing for activation under normal room light conditions without the need for high-intensity external light stimulation (Subramaniam et al., 2022). Upon light activation, the MCO protein acts as a cation channel, triggering depolarization of the bipolar cells and subsequent signaling to the optic nerve. This mutation-agnostic approach represents a significant advancement in regenerative medicine for blindness, as it does not depend on the specific genetic defect causing the photoreceptor loss (NCT04919473).

Other names

MCO-010vMCO-ISonigearMulti-characteristic opsin

Ectopic expression of a light-sensitive opsin in retinal bipolar cells to restore photosensitivity in the absence of functional photoreceptors (Batabyal et al., 2021).