Not dead, but asleep

Future treatments for diabetic retinopathy could work by “waking up” retinal cells, after a new study has found that these cells enter a dormant state as the disease progresses, rather than dying.

Canadian researchers discovered the cells in a “sleeping” pattern, known as senescence, when examining the neurons, blood vessels and immune cells in mice retinas that had been cut off from their oxygen and nutrient supply.

They also found that these dormant cells start producing molecules that ultimately exacerbate the condition.

University of Montreal assistant professor, Dr Frederick Mallette, told OT that, hypothetically, diabetic retinopathy could be triggering one of the body’s cancer-protection responses, hence the production of these damaging molecules.

“But we still don’t know exactly why this occurs in this particular setting. As cellular senescence is a response to stress…it might allow the preservation of tissue integrity in situations of acute or chronic stress,” he added.

The senescent state of the cells did not last indefinitely, but was transient and changed as the disease progressed, he explained.

Currently, no medicines or therapies have yet been found that can “switch on” human senescent cells.

Yet, tracking exactly which molecules the dormant retinal cells produced led to some exciting results. By limiting this production, the scientists were able to enhance the health of the retina and the normal growth of blood vessels in mice, Dr Mallette highlighted.

These findings offer hope for new drugs to stop retinal degradation for human patients. The research team is also examining the fate of the dormant retinal cells, Dr Mallette explained, adding: “These cells seem able to ‘recover’ under certain conditions.”

Image credit: Andrew R Dieselducy