How neurons build a 3-D vascular structure to keep the retina healthy

Key Takeaways

• Researchers have found a new type of neuron that guides the formation of the blood vessel lattice that nourishes cells in the retina. 
• The discovery could inspire new ways of treating neurodegenerative diseases such as glaucoma, retinitis pigmentosa and age-related macular degeneration by ensuring that neurons, which demand a lot of energy, maintain a healthy blood supply.

Scientists have known for years that a lattice of blood vessels nourishes cells in the retina that allow us to see — but it’s been a mystery how the intricate structure is created. Now, researchers at UC San Francisco have found a new type of neuron that guides its formation. The discovery, described in the journal Cell, could one day lead to new therapies for diseases that are related to impaired blood flow in the eyes and brain. “This [discovery] brings us closer to the possibility of repairing them [blood vessel lattices] when they’re damaged or rerouting them when they weren’t built right in the first place,” said Xin Duan, PhD, an associate professor of ophthalmology and senior author of the study.

The researchers worked with newborn mice, whose eyes still need several weeks to develop fully. Kenichi Toma, PhD, labeled the retinal neurons closest to the blood vessels with a protein that glows green under ultraviolet light so he could observe the lattice as it was forming. The team then identified a subset of neurons, called perivascular neurons, which contact and then surround growing blood vessels, directing them to form the lattice. These perivascular neurons produce a protein called PIEZO2 that enables them to sense when they are touching another cell.

The team further found that perivascular neurons in mice that were unable to produce PIEZO2 could not maintain contact with blood vessels, and they grew in a tangled, disorganized way that disrupted blood flow. Starved for oxygen, the surrounding nerve cells degraded, and the mutant mice were more vulnerable to stroke-like injuries.

The discoveries could inspire new ways of treating neurodegenerative diseases such as glaucoma, retinitis pigmentosa, and age-related macular degeneration by ensuring that neurons, which demand a lot of energy, maintain a healthy blood supply. “There are lots of people trying to understand the ways we can grow neurons,” Duan said. “But how in the world do we grow the intricate networks of blood vessels required to support them? That’s the question we’re trying to answer.” 

Edited by Miriam Kaplan, PhD

Source: University of California, San Francisco, ScienceDaily, May 24, 2024; see source article