Lab-Grown Eye Cells Connect To ‘Neighbors’ In Step Toward Human Trials

Until now, despite the advancements in medical science and research, patients afflicted with blindness often find themselves with very few treatment options to choose from once the disorder takes hold. 

Fortunately, scientists at the University of Wisconsin-Madison have recently made a breakthrough in stem cells that could finally lead to a cure for degenerative eye disorders. The study first began over a decade ago, when researchers developed a way to grow organoids—an organized cluster of cells that resembles the retina. 

Human skin cells were reprogrammed to act as stem cells, which in turn transformed into layers of several types of retinal cells—those forming the light-sensitive tissue at the back of our eyes—that help us to sense light and transmit the image before us to our brain. 

Now, the team has successfully shown retinal cells grown from stem cells can “reach out and connect” with neighbors, completing a “handshake” that indicates these cells are now ready to move forward with clinical trials involving human patients. 

For the stem cells to turn into a functional cure for degenerative diseases, the key question was if these cells, having been grown in a laboratory dish, could behave appropriately when teased apart and introduced to a human eye.

The answer appears to be yes, with studies from researchers showing the dish-grown cells responded similarly to those in a healthy retina to varying wavelengths and intensities of light, and could “reach out” using biological cords when separated from other cells in the organoid. 

Simply put, cells in our retina and brain communicate via synapses—tiny gaps at the tips of the cords. In order for the lab-grown stem cells to replace diseased ones, scientists had to ensure they could make synapses, which was successfully demonstrated in a series of experiments. 

“We’ve been quilting this story together in the lab, one piece at a time, to build confidence that we’re headed in the right direction. It’s all leading, ultimately, to human clinical trials, which are the clear next step,” says David Gamm, Ophthalmology Professor at UW-Madison. 

Some of the most common cells that formed synapses were photoreceptors, which could replace diseased cells in patients suffering from retinitis pigmentosa and age-related macular degeneration, while retinal ganglion cells can be used to treat nerve disorders such as glaucoma.

[via StudyFinds and University of Wisconsin-Madison, images via various sources]