Blind mice had their eyesight restored. A new method for regenerating the eye

Scientists have developed a new method of eye regeneration that has restored sight to mice blind from birth. The new technique involves turning Müller cells into rods – visual cells that are sensitive to light – and offers hope for developing new therapies for eye diseases.

Researchers’ discoveriesow from the National Eye Institute (NEI), one of the 27 institute’soat the National Institute ofoin Health – a U.S. government research institution, are raising the prospect of developing new, effective regenerative therapies for eye diseases such as age-related macular degeneration, aolte and pigmentary retinal degenerationowki. The results of the study were published on „Nature”.

– These are the first studies by scientistsow reprogramming cellsoMüllera in this wayob to become functional photoreceptors – rods – in the retinaowce mammalianow – said Thomas N. Greenwell of the NEI.

There are two types of photoreceptors in our eyesow – photosensitive cellsorecords located in the reticularowce allowing us to see. It’s cones and rods. The former enable us to see colorow. In contrast, the other are about 20 times more numerous and up to 1,000 times more sensitive to light and are responsible for shape perceptionow and motion. In mammalsoin, including mice and humans, photoreceptors themselves do not regenerate. Like most neuronow, once mature they do not divide.

– Rods allow us to see in low light, but can also pomoc in preserving the conesoIn, whichore are important for color vision and high visual acuity. The cones tend to die in poThe later stages of the chorob eyes. If the rods can be regenerated, this may be a strategy for treating diseasedob eyes, whichore affect photoreceptors – explained Greenwell.

KomoMüllera have long been an object of scientific interestow. Headownie due to the fact that they can potentially serve as comork precursor cells. They are the most common type of comoglial cells located in the retinaowce. Headowki’s roleoMüllera is to maintain the structural and functional stability of the comorek volleyballowki. This includes regulation of the extracellular environmentoller by uptake of neurotransmitterow, debris removal, glycogen storage and mechanical support of the reticularoneural tube.

Researchers have been studying the regenerative potential of comorec Müllera, because in other species ofow, such as the striped danios (a freshwater fish in the carp family), divide in response to injury and can develop into photoreceptors and other reticular neuronsowki. In this wayob danio striped danios can recover from severe retinal damageowki. In the lab, the scientists managed to force the comorki Müllera mammalianow to behave more like a fish. But it requires tissue damage.

– From a practical point of view, if proYou want to regenerate the netowka to restore theoct a person’s eyesight, injuring their eyes seems like the wrong thing to do, but by doing so, you can activate the comorki Müllera – said Professor Bo Chen of the Icahn School of Medicine at Mount Sinai in New York. – We wanted to see if we could program the comorki Müller to become rods in a living mouse, without having to injure the retinaowki – added.

In the first phase of the two-stage process of reprogramming the team’soł Chen stimulated the comorki Müller in healthy mice to divide by injecting a gene that turns on a protein called beta-catenin. Several weeks poź later injected into the eyes of mice the factors thatore encouraged the newly divided cellsorki to transform into rods.

Researchers used microscopy to visually track newly formed comorek. They discovered that newly formed stamens do not roThey are different in appearance from the natural rodow. In addition, the aforementioned treatments have created synaptic structures, ktore allow rods to communicate with other types of neuronsow within the volleyballowki.

To determine whether stamens derived from comorec Müllera were functional, they tested a new therapy on mice with congenital blindness – without functional rodsow. Stamens derived from the comorek Müllera formed as effectively as in healthy mice. The newly formed photoreceptors also communicated with other types of neuronoin the reticularowki. This has been confirmed by measurements of the activity of mozgu.

Scientists are now testing whether mice have recovered their ability to perform visual tasks. They will also study whether the technique works on human retinal tissueowki cultured in the laboratory.