Scientists have found the mechanism by which zebrafish heal their damaged retinas, an advance that sheds more light on the potential natural healing pathways that could be tapped in humans.
Mammals do not have the ability to immediately regenerate injured parts but zebrafish -- widely used as a model organism in research studies -- can spontaneously undergo a regenerative response if their retina is damaged, restoring both its structure and function.
The researchers led by James Patton of Vanderbilt University in the US found how Muller glia (MG) cells in the retina of adult zebrafish un-specialise into a stem cell-like state, and give rise to cells that are capable of differentiating into different cell types.
The study, published in the journal Cell Reports, found the mechanism by which a small molecule in the zebrafish retinal cells -- a microRNA called miR-216a -- regulated the formation of another molecule Dot1l, which is an enzyme involved in regulating some genes.
When miR-216a was suppressed, the researchers found that the differentiation and proliferation of MG cells was initiated.
The authors note that the next step of their research is to find regulatory mechanisms with potential drug targets for enhancing regeneration in the retina of adult mammals.
"Mller 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 behaviour in the human retina," said Professor Patton Stevenson, Director of the Interdisciplinary Graduate Program at Vanderbilt.