A newly identified retinal signaling molecule may help coordinate the eye’s response to damage, revealing a potential avenue for slowing vision loss in degenerative eye diseases.
For millions of people affected by conditions such as age-related macular degeneration, diabetic retinopathy, and retinitis pigmentosa, vision loss often begins with the gradual death of photoreceptors, the light-sensing cells that allow the eye to detect and process visual information.
While many current treatments focus on specific diseases or symptoms, scientists are increasingly searching for ways to strengthen the retina’s own ability to withstand damage.
A new study suggests that one naturally occurring molecule may play an important role in that process. Researchers at Scripps Research, working with collaborators at UC San Diego and the Lowy Medical Research Institute, identified a lipid molecule called erucamide as a key player in retinal cell communication.
Reporting in Nature Neuroscience on June 19, 2026, the team found that erucamide levels drop as photoreceptors begin to die. Restoring the molecule activated protective cellular responses that helped stabilize retinal tissue. The findings suggest erucamide may be part of the retina’s natural defense system and could point to a new strategy for slowing the progression of vision-threatening diseases.
The Retina’s Response to Injury
“The retina doesn’t simply deteriorate; in fact, it actively responds to injury,” says senior author Martin Friedlander, a professor at Scripps Research. “Our work identifies erucamide as a signaling molecule that helps coordinate that response.”
Healthy vision depends on constant communication among neurons, glial cells, blood vessels, and immune cells. Together, these components form the neurovascular unit, a network that supports retinal function. In conditions such as diabetic retinopathy, retinitis pigmentosa, and age-related macular degeneration, this communication begins to break down. As photoreceptors are lost, vision progressively worsens.
The study builds on earlier work from Friedlander’s group showing that transplanted stem cell-derived retinal cells could slow degeneration even after the transplanted cells had disappeared. That finding suggested the cells were releasing protective molecules that continued working after the cells themselves were gone. Researchers then set out to identify those signals.
Although lipid molecules are known to act as biological messengers throughout the body, many have received little attention in retinal disease research. To look for overlooked candidates, the team used mass spectrometry-based metabolomics, a method that can measure large numbers of small molecules in tissue samples at the same time.
The researchers analyzed several established preclinical models of retinal degeneration and tracked how molecular levels changed as disease advanced.
Among the molecules they identified, erucamide drew particular attention. Its levels dropped significantly as photoreceptors began to deteriorate, suggesting the change was linked to the disease process rather than being a secondary effect.
“That was a pivotal moment for us,” recalls co-author Dale Boger, the Richard and Alice Cramer Professor of Chemistry at Scripps Research. “It raised the possibility that erucamide could be influencing how tissue responds and wasn’t just changing as a consequence of disease.”
Delivering Erucamide to the Retina
To determine whether restoring erucamide could influence retinal degeneration, the researchers delivered the molecule into the eye using porous silicon nanoparticles. These tiny engineered carriers are designed to release compounds in a controlled manner.
Because erucamide is hydrophobic (meaning it doesn’t dissolve well in water) and tends to clump together when injected, the nanoparticles helped keep it stable and more evenly distributed throughout the tissue.
The molecule did not act directly on photoreceptors. Instead, it activated CD11b⁺ myeloid cells, a type of immune cell in the retina that responds to injury and helps maintain tissue health. The researchers also identified a protein called TMEM19 that binds to erucamide. When TMEM19 levels were reduced, the myeloid cells were no longer activated, and erucamide’s protective effects disappeared.
Once activated, the myeloid cells released signals linked to neurovascular stabilization, helping support both retinal nerve cells and the blood vessels that supply them. Although erucamide did not reverse retinal damage, it slowed some aspects of degeneration by preserving the structure and function of the remaining tissue.
“Instead of targeting the photoreceptors themselves, erucamide appears to work by engaging the surrounding environment,” explains first author Guoqin Wei, a staff scientist at Scripps Research who began working on this project as a postdoctoral research associate in Friedlander’s lab seven years earlier. “That shift in perspective could be important for treating degenerative retinal diseases going forward.”
Future Therapeutic Potential
While the study provides new insight into how erucamide works, researchers say more studies are needed to fully understand the signaling pathway involved. Future research will examine the molecule’s role across different retinal diseases and determine whether targeting this pathway can provide lasting therapeutic benefits.
The team is also working to overcome a practical challenge. Because erucamide is hydrophobic and most eye medications are water-based, developing a treatment formulation may be difficult. Researchers plan to improve delivery methods and test modified versions of erucamide to see whether they produce stronger or longer-lasting effects. They will also investigate related lipid molecules that may be even more effective at triggering protective responses.
More broadly, the findings suggest that naturally occurring molecules already present in the body could be used to help tissues withstand disease-related stress. The results point to a potential strategy for slowing retinal degeneration by strengthening the retina’s own protective mechanisms.
“The goal is to reinforce a signal that’s already present,” notes Friedlander. “If we can learn how to modulate that response carefully, it could offer a new path for slowing the progression of retinal diseases where treatment options remain limited.”
Reference: “A fatty acid amide activates myeloid cells and improves neurovascular outcomes in retinal degeneration” by Guoqin Wei, Shreyosree Chatterjee, Qinglin Yang, Sanahan Vijayakumar, Daisuke Ogasawara, Sarah Giles, Katie Biscocho, Peter Westenskow, Junhua Wang, Ruhan Fan, Helena Pham, Edith Aguilar, Jacob Robinson, Ayumi Usui-Ouchi, Roberto Bonelli, Kevin Eade, Gary Siuzdak, Benjamin Cravatt, Michael J. Sailor, Dale Boger and Martin Friedlander, 19 June 2026, Nature Neuroscience.
DOI: 10.1038/s41593-026-02341-w
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