
An artist’s rendering incorporates the images of the Müller glia-derived rod photoreceptors.Bo Chen, Ph.D.
New technique generates rod photoreceptors that integrate into the retina and brain.
Researchers funded by the National Eye Institute (NEI) have reversed congenital blindness in mice by changing supportive cells in the retina called Müller glia into rod photoreceptors. The findings advance efforts toward regenerative therapies for blinding diseases such as age-related macular degeneration and retinitis pigmentosa. A report of the findings appears online today in Nature. NEI is part of the National Institutes of Health.
“This is the first report of scientists reprogramming Müller glia to become functional rod photoreceptors in the mammalian retina,” said Thomas N. Greenwell, Ph.D., NEI program director for retinal neuroscience. “Rods allow us to see in low light, but they may also help preserve cone photoreceptors, which are important for color vision and high visual acuity. Cones tend to die in later-stage eye diseases. If rods can be regenerated from inside the eye, this might be a strategy for treating diseases of the eye that affect photoreceptors.”
Photoreceptors are light-sensitive cells in the retina in the back of the eye that signal the brain when activated. In mammals, including mice and humans, photoreceptors fail to regenerate on their own. Like most neurons, once mature they don’t divide.
Scientists have long studied the regenerative potential of Müller glia because in other species, such as zebrafish, they divide in response to injury and can turn into photoreceptors and other retinal neurons. The zebrafish can thus regain vision after severe retinal injury. In the lab, however, scientists can coax mammalian Müller glia to behave more like they do in the fish. But it requires injuring the tissue.
“From a practical standpoint, if you’re trying to regenerate the retina to restore a person’s vision, it is counterproductive to injure it first to activate the Müller glia,” said Bo Chen, Ph.D., associate professor of ophthalmology and director of the Ocular Stem Cell Program at the Icahn School of Medicine at Mount Sinai, New York.
“We wanted to see if we could program Müller glia to become rod photoreceptors in a living mouse without having to injure its retina,” said Chen, the study’s lead investigator.
In the first phase of a two-stage reprogramming process Chen’s team spurred Müller glia in normal mice to divide by injecting their eyes with a gene to turn on a protein called beta-catenin. Weeks later, they injected the mice’s eyes with factors that encouraged the newly divided cells to develop into rod photoreceptors.
The researchers used microscopy to visually track the newly formed cells. They found that the newly formed rod photoreceptors looked structurally no different from real photoreceptors. In addition, synaptic structures that allow the rods to communicate with other types of neurons within the retina had also formed. To determine whether the Müller glia-derived rod photoreceptors were functional, they tested the treatment in mice with congenital blindness, which meant that they were born without functional rod photoreceptors.
In the treated mice that were born blind, Müller glia-derived rods developed just as effectively as they had in normal mice. Functionally, they confirmed that the newly formed rods were communicating with other types of retinal neurons across synapses. Furthermore, light responses recorded from retinal ganglion cells — neurons that carry signals from photoreceptors to the brain — and measurements of brain activity confirmed that the newly-formed rods were in fact integrating in the visual pathway circuitry, from the retina to the primary visual cortex in the brain.
Chen’s lab is conducting behavioral studies to determine whether the mice have regained the ability to perform visual tasks such as a water maze task. Chen also plans to see if the technique works on cultured human retinal tissue.
Learn more: NIH-funded researchers reverse congenital blindness in mice
The Latest on: Congenital blindness
[google_news title=”” keyword=”congenital blindness” num_posts=”10″ blurb_length=”0″ show_thumb=”left”]
via Google News
The Latest on: Congenital blindness
- OSU, OHSU researchers use nanoparticles to target hereditary blindnesson January 11, 2023 at 3:22 pm
Researchers from Oregon Health & Science University and Oregon State University have demonstrated a new approach to treating blindness associated with a rare genetic condition by using lipid ...
- Researchers take key step toward new treatment for hereditary blindnesson January 11, 2023 at 1:12 pm
Researchers take key step toward new treatment for hereditary blindness Date: January 11, 2023 Source: Oregon State University Summary: Scientists have demonstrated in animal models the ...
- Nanotechnology may improve gene therapy for blindnesson January 11, 2023 at 11:02 am
Using nanotechnology that enabled mRNA-based COVID-19 vaccines, a new approach to gene therapy may improve how physicians treat inherited forms of blindness. A collaborative team of researchers ...
- Obesity can cause macular degeneration, blindness in the elderlyon January 11, 2023 at 6:12 am
Age-related macular degeneration (AMD) is a major cause of vision impairment and blindness in older people around the world – with an incidence of 30% over the age of 70, 40% over the age of 80 ...
- Prolonged screen time may cause retinal detachment - risk of 'blindness' warns experton January 10, 2023 at 4:44 pm
These signs can be common signs of impending blindness due to retinal detachment, however. Retinal detachment is generally associated with trauma to the eye and vitamin deficiencies, but the sight ...
- Using lipid nanoparticles and messenger RNA to treat blindness associated with rare genetic conditionon January 10, 2023 at 4:00 pm
Sahay and Ryals have received a $3.2 million grant from the National Eye Institute to continue studying lipid nanoparticles' promise in the treatment of hereditary blindness. They will lead ...
- Blindness, Pollyannas and conspiracy theoristson January 7, 2023 at 10:22 pm
Famed French novelist Paul Bourget said: "There are conditions of blindness so voluntary that they become complicity." Blindness is not only physical. It is also a state of mind. Many among us do ...
- Exhibit ‘Chosen Blindness’ strives to bring attention to trauma in animalson January 6, 2023 at 1:58 pm
A sculpture by Mark Dyke is part of the “Chosen Blindness” exhibit. (Courtesy of Albuquerque Contemporary Art Center) With the cold temperature outside, maintaining your mental health is ...
- People with visual impairment, blindness in Switzerland still face many barriers: Advocacy groupon January 5, 2023 at 6:39 am
People with visual impairment and blindness in Switzerland "still face many barriers," the Swiss National Association of and for the Blind (SNAB) told Anadolu Agency in an interview, citing a UN ...
via Bing News