Zebrafish could unlock the secret of human retina regeneration, a new study reports.
While mammals can’t spontaneously regenerate retinal neurons as they’re lost to injury or disease, bony fish don’t have the same issue. New research from the Vanderbilt University aims to unlock their secret and ‘borrow’ it for human use.
A whole different retina of fish
“Müller glia constitute an adult stem cell in the zebrafish retina and our goal is to identify pathways and genes that could be activated to induce similar behavior in the human retina,” said James Patton, Ph.D, Stevenson Professor of Biological Sciences and director of the Interdisciplinary Graduate Program at Vanderbilt.
We have precious few treatments available today for retinal degenerative diseases such as age-related macular degeneration (AMD) or retinitis pigmentosa. The former is the leading cause of blindness for Americans over the age of 55, affecting millions, while the latter affects around 100,000 Americans and render them legally blind by the age of 40.
However, there are grounds for optimism: the structure of the retina is pretty consistent among vertebrates, and bony fish, such as the tiny zebrafish, can trigger a spontaneous regenerative response that restores both retinal structure and function. It’s even better when you consider that the zebrafish is a widely-used “model organism” in biological and medical research.
One key factor in this process, the team found, is the microRNA molecule miR-216a, which regulates the expression of Dot1l, an enzyme involved in regulating gene expression. The authors report that suppressing miR-216a jump-starts cell division and differentiation in the Müller glia, the source of regenerated neurons in the zebrafish retinas.
Should the team be able to prove that miR-216a suppression can induce a similar effect in the Müller glia of mammals, it could open the way to novel treatments for retina degeneration in humans. However, that’s still a pretty long way away for now.
The paper “The miR-216a-Dot1l Regulatory Axis Is Necessary and Sufficient for Müller Glia Reprogramming during Retina Regeneration” has been published in the journal Cell Reports.