Modified Neuropeptide Y Protects Eye Nerves Without Dangerous Blood Vessel Constriction
A truncated form of neuropeptide Y (NPY 3-36) provided neuroprotection in experimental glaucoma without causing the retinal vasoconstriction seen with full-length NPY.
Quick Facts
What This Study Found
Truncated NPY (3-36) selectively activated neuroprotective pathways (via Y2/Y5 receptors) while avoiding vasoconstriction (mediated by Y1 receptors), demonstrating that receptor-selective peptide analogs can dissociate beneficial from harmful effects in glaucoma treatment.
Key Numbers
- NPY(1-36): caused transient vasoconstriction via Y1 receptor
- NPY(3-36): no vasoconstriction; selectively activates Y2 and Y5 receptors
- NPY(3-36) preserved retinal ganglion cell density under elevated IOP
- Reduced astrocytic and microglial activation
How They Did This
Animal study in mice using fluorescein angiography to assess retinal vascular responses after intravitreal injection of NPY analogs, followed by evaluation of neuroprotective effects in an experimental glaucoma model.
Why This Research Matters
Glaucoma is a leading cause of blindness, and neuroprotection of retinal ganglion cells is a major unmet need. This study shows that peptide modification can eliminate dangerous side effects while preserving therapeutic benefit, advancing NPY-based therapies toward clinical viability.
The Bigger Picture
This elegant receptor-selectivity approach could be applied beyond ophthalmology. Many peptides have both beneficial and harmful effects mediated by different receptors — truncation and modification strategies could unlock safer peptide therapeutics across multiple fields.
What This Study Doesn't Tell Us
Animal study only — mouse retinal physiology may differ from human; intravitreal injection is invasive; long-term safety and efficacy of repeated NPY (3-36) dosing not established; glaucoma models may not fully replicate human disease.
Questions This Raises
- ?Could NPY (3-36) be delivered through less invasive routes, such as eye drops or sustained-release implants?
- ?Does the neuroprotective effect persist long-term, or would repeated injections be needed?
- ?Would this approach work in other neurodegenerative conditions where NPY has shown promise?
Trust & Context
- Key Stat:
- Y2/Y5 selective Truncated NPY (3-36) achieved neuroprotection through selective receptor activation without Y1-mediated vasoconstriction
- Evidence Grade:
- Preclinical animal study with clear mechanistic demonstration. Strong proof-of-concept but requires translation to larger animal models and human trials.
- Study Age:
- Published in 2025, reflecting ongoing innovation in peptide-based neuroprotection.
- Original Title:
- Selective Receptor Modulation by Truncated Neuropeptide Y (3-36) Dissociates Vasoconstriction from Neuroprotection in Experimental Glaucoma.
- Published In:
- Molecular neurobiology, 63(1), 334 (2025)
- Authors:
- Palanivel, Viswanthram(3), Basavarajappa, Devaraj(3), Salkar, Akanksha(3), Komáromy, András M, Tietz, Ole, Eva, Taslima Akter, Chitranshi, Nitin, Mirzaei, Mehdi, Gupta, Veer, You, Yuyi, Graham, Stuart L, Gupta, Vivek
- Database ID:
- RPEP-12922
Evidence Hierarchy
Tests effects in animals (usually mice or rats), not humans.
What do these levels mean? →Frequently Asked Questions
What is neuropeptide Y?
Neuropeptide Y (NPY) is one of the most abundant peptides in the nervous system. It plays roles in appetite, stress response, and nerve cell survival. In the eye, it can protect nerve cells but also constricts blood vessels.
Why can't the full version of this peptide be used for glaucoma?
Full-length NPY activates all its receptor types, including one (Y1) that tightens blood vessels in the retina. This could reduce blood flow to the eye and worsen the very damage glaucoma causes. The shortened version avoids this receptor while keeping the protective effects.
Read More on RethinkPeptides
Cite This Study
https://rethinkpeptides.com/research/RPEP-12922APA
Palanivel, Viswanthram; Basavarajappa, Devaraj; Salkar, Akanksha; Komáromy, András M; Tietz, Ole; Eva, Taslima Akter; Chitranshi, Nitin; Mirzaei, Mehdi; Gupta, Veer; You, Yuyi; Graham, Stuart L; Gupta, Vivek. (2025). Selective Receptor Modulation by Truncated Neuropeptide Y (3-36) Dissociates Vasoconstriction from Neuroprotection in Experimental Glaucoma.. Molecular neurobiology, 63(1), 334. https://doi.org/10.1007/s12035-025-05636-4
MLA
Palanivel, Viswanthram, et al. "Selective Receptor Modulation by Truncated Neuropeptide Y (3-36) Dissociates Vasoconstriction from Neuroprotection in Experimental Glaucoma.." Molecular neurobiology, 2025. https://doi.org/10.1007/s12035-025-05636-4
RethinkPeptides
RethinkPeptides Research Database. "Selective Receptor Modulation by Truncated Neuropeptide Y (3..." RPEP-12922. Retrieved from https://rethinkpeptides.com/research/palanivel-2025-selective-receptor-modulation-by
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkPeptides research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.