Our eyes could potentially be coaxed into a special repair mode above and beyond our natural self-healing abilities, according to a new study, thanks to the delivery of antibodies that trigger nerve cell regeneration in the retina.
The South Korean research team says the treatment offers hope for restoring lost vision that otherwise can’t be brought back. For now though, it’s only been tested in mice.
Here’s how it works: a compound antibody drug is used to block the prospero homeobox protein 1 (Prox1). This protein isn’t inherently bad, playing an important role in cell regulation, but it appears to stop retinal nerves from regenerating.
Specifically, Prox1 seeps into retina nerve support cells called Müller glia (MG) cells after damage occurs, interfering with their regenerative powers. We know MG cells are responsible for self-healing retinal nerve cells in zebrafish, but in mammals, Prox1 acts as an MG blocker – which this treatment removes.
“Individuals with retinal degenerative diseases struggle to restore vision due to the inability to regenerate retinal cells,” write the researchers.
“Unlike cold-blooded vertebrates, mammals lack MG-mediated retinal regeneration, indicating the limited regenerative capacity of mammalian MG.”
The researchers were able to successfully test their Prox1-blocking methods in lab experiments and mice models, which suggests the approach could work in human eyes as well, with some further development.
What’s more, the effects of keeping Prox1 in its place were shown to last for six months and beyond, making this the first successful long-term neural retina regeneration we’ve seen in mammals.
“In mice, Prox1 in MG originates from neighboring retinal neurons via intercellular transfer,” write the researchers. “Blocking this transfer enables MG reprogramming into retinal progenitor cells in injured mouse retinas.”
Clearly there’s a lot more work to do before this can be tested on human subjects, but the research has identified a crucial biological reason why mammals can’t regenerate cells in the eye – and shown that self-healing capabilities can be unlocked. Clinical trials could begin by 2028, the researchers say.
The study links in with other research investigating how eye damage could be repaired: from activating retinal cells with lasers to transplanting new stem cells into the eye, many different approaches are being looked at.
When it comes to degenerative retinal diseases, including retinitis pigmentosa and glaucoma, we’re talking about hundreds of millions of people who are affected worldwide. Once the vision is lost, it doesn’t come back.
And we also know that the world’s population is getting older. These findings could have important implications for maintaining a good quality of life into old age – life without the vision loss that might otherwise happen.
“Our goal is to provide a solution for patients at risk of blindness who currently lack proper treatment options,” says Eun Jung Lee, biologist at Korea Advanced Institute of Science and Technology (KAIST).
The research has been published in Nature Communications.
