A new study shows that retinal cells grown from stem cells can communicate with their neighbours, and that the cells are ready for experiments in humans with degenerative eye disorders.
More than a decade ago, researchers from the University of Wisconsin-Madison developed a way to grow organized groups of cells called “organelles” that resemble the retina, the light-sensitive tissue at the back of the eye. They coaxed human skin cells reprogrammed to act as stem cells to develop into layers of several types of light-sensing retinal cells and eventually transmit what we see to the brain.
“But after they grew in a lab dish for months as compact clusters, the question remained: Will the cells behave appropriately after we separate them?” Because this is the key to inserting it into the patient’s eye, ”according to the specialized medical site, “Medical Express”.
And during 2022, Jam and the university publish studies showing that retinal cells grown in dishes, called photoreceptors, respond like those in a healthy retina to different wavelengths of varying intensities, and, once separated from neighboring cells in their membership, they can reach new neighbors with biological cords. characteristic called axes.
According to Jam, whose new research on successful cell-to-cell communication will be published this week in Proceedings of the National Academy of Sciences, “Cells in the retina and brain communicate via synapses; They are small gaps at the ends of the ropes. To ensure that retinal cells grown in the laboratory had the ability to replace diseased cells and carry sensory information as well as healthy cells, the researchers needed to demonstrate their ability to make synapses.
Notably, Dr. Xinyu Zhao, UW-Madison Professor of Neuroscience and co-author of the new study, worked with cells in Jam’s lab to help study their ability to form synaptic connections. They did this by using a modified rabies virus to identify pairs of cells that could communicate with each other.
In this context, the research team, including graduate students and co-authors of the study; Allison Ludwig and Stephen Myrl, divide retinal organelles into individual cells, give them a week to expand their axons and make new connections, expose them to the virus, and then take a sneak peek. What they saw were many fluorescently labeled retinal cells, indicating that a rabies infection had hit one through synapses that had successfully formed between its neighbours.
“All of this eventually leads to human clinical trials, which is the obvious next step,” says Jam, who patented the organics and co-founder of Madison-based Opsis Therapeutics, which is adapting the technology to treat human eye disorders based on UW-Madison’s discoveries.
Having confirmed the existence of the synaptic connections, the researchers analyzed the cells involved and found that the most common types of retinal cells that form synapses are photoreceptors (rods and cones), which are lost in diseases such as retinitis pigmentosa and age-related macular degeneration, as well as in some eye injuries. The second most common type of cell is the retinal ganglion cell that degenerates in optic nerve disorders such as glaucoma.
“This was an important revelation for us,” Jam says. It really shows the potential broad impact these retinal organelles can have.”