Stem Cell Success in Lab may Yield Future Blindness Cure
The study researchers successfully transplanted photoreceptor cells in night-blind mice and discovered that the cells developed normally. The cells were then integrated into the mice’s existing retina and subsequently formed the necessary nerve connections that transmit visual information to the brain. The study demonstrates that embryonic stem cells could potentially provide an infinite supply of healthy photoreceptors for retinal cell transplantations to treat human blindness.
Photoreceptors are light-sensitive nerve cells typically found in the retina of the eye. Two types of photoreceptors exist – rods and cones. The cones are responsible for the eye’s color sensitivity. The rods are sensitive to light and are especially important for providing the capacity to see in the dark.
According to the study authors, losing the photoreceptors in an eye is a major cause of vision loss in degenerative eye conditions such as retinitis pigmentosa, diabetes-related blindness and age-related macular degeneration.
With the use of 3D culture and differentiation of mouse embryonic cells, researchers were able to grow retinal precursor cells. These precursor cells were closely compared to normally developed cells, with the researchers noting different developmental stages.
For the study, researchers injected close to 200,000 or the lab grown stem cells into the retinas of night-blind mice. The study reports that three weeks following transplantation, the synthetic retina cells had moved and integrated within the mice retina and began to take the shape of normal mature rod cells, which remained following six weeks.
Lead author Professor Robin Ali concludes, "There are a number of ways that we can use this research to develop ways of treating blindness through gene therapy and artificial retinas. This is a very exciting approach because it has the ability to restore vision in patients who have very little vision, and the main cause of this in the developing world is loss of photoreceptors. Currently there is no treatment for that."