Fish eyes might hold cures to blindness

Zebrafish cells regenerate to repair damage

What heals the eyes of tiny fish might point the way to helping heal human eyes of damaging diseases that are major causes of blindness, said researchers at Georgia Health Sciences University.


The university held its third annual Vision Discovery Institute Scientific Retreat on Tuesday to review promising research there.

Junko Ariga, a graduate student in the Neuroscience Program at GHSU, presented her work in zebrafish, an animal prized for its replication and regeneration of lost cells.

Working in the lab of Dr. Jeffrey Mumm, who also studies regeneration in zebrafish, Ariga looked at cells known as Müller glial cells that work to keep healthy the retina -- the area in the back of the eye responsible for sight. Both mammals and zebrafish have the cells, and they seem to respond to damage in both, but in different ways, Ariga said.

In mammals, it is "like an inflammatory response," she said. "Whereas in zebrafish, they react more like stem cells and they regenerate all of the retinal cells."

The response in mammals creates these "huge, sort of nasty scar-like tissues," Mumm said, but in zebrafish seems to create the cell types needed.

The lab started by looking for hints in literature on potential regeneration in mammals and then looked for the equivalent in zebrafish, Mumm said.

"The main logic there was, if the same pathways are being used in a regenerative manner in both systems, it sort of lends credence to the idea that what we learn about the regenerative regulation in fish will be applicable ... hopefully also in humans," he said.

Ariga might have found that pathway in mammals, Mumm said.

"That was one of the most interesting things about Junko's most recent work is that one of these molecular pathways that has a limited capacity but nevertheless can enhance regeneration in mammals also appears to be critical for allowing the fish to regenerate at all," he said.

The work now is to create zebrafish without the pathway, to study the genes involved and potentially use the fish for drug screening, Mumm said. The point of work like this is not just to define the problem but to move beyond it.

"Rather than what it does, we hope to define what it can do," he said.