12 Mar Researchers ‘seq’ and find a way to make pig retinal cells to advance eye treatments
A retinal organoid examined at an early stage of differentiation shows different cells visualized by immunocytochemistry. Photo courtesy of Kim Edwards.
Inside the human eye, the retina is made up of several types of cells, including the light-sensing photoreceptors that initiate the cascade of events that lead to vision. Damage to the photoreceptors, either through degenerative disease or injury, leads to permanent vision impairment or blindness.
David Gamm, director of UW–Madison’s McPherson Eye Research Institute and professor of ophthalmology and visual sciences, says that stem cell replacement therapy using lab-grown photoreceptors is a promising strategy to combat retinal disease. The challenge is that stem cell treatments aimed at replacing photoreceptors need to first be tested in animals. Since human cells are not compatible in other species and are quickly rejected when transplanted, it’s difficult to assess their potential.
“Pig and human retinas share many key features, making pigs ideal for modeling human retinal disease and testing ocular therapeutics,” Gamm says. “By testing ‘human-equivalent’ photoreceptors in pigs, we can get a better sense of what these cells can do if they are not immediately attacked by the host animal.”
In a new study published in Stem Cell Reports, the Gamm Lab partnered with researchers at the Morgridge Institute for Research to develop lab-grown pig retinal organoids. They found that pig-derived photoreceptors shared many similarities with those made from human retinal organoids.
“This is the first time that people have made pig retinal organoids,” says Kim Edwards, a graduate student in the Gamm Lab and first author of the study. “And this was the first time that people have done a comparison of human versus another species of retinal organoids.”