Peptides FGLM-NH2 (from substance P) and SSSR (from IGF-1) promoted corneal wound healing in neurotrophic keratopathy through the NK-1 receptor, Akt signaling, and suppression of inflammatory cytokines.
NK-1Rreceptor identified as the key mediator of peptide-driven corneal wound healing
What the researchers found
FGLM-NH2 and SSSR promoted corneal epithelial healing through the substance P-NK-1R axis, activating Akt signaling and suppressing inflammatory cytokines IL-1α, MIP-1α, and MIP-1β. NK-1R antagonist L-733,060 abolished the healing effect.
Why it matters
Neurotrophic keratopathy is a sight-threatening condition with limited treatments. Understanding the specific receptor and signaling mechanism of these peptide eye drops supports their clinical development and optimization.
The numbers in context
FGLM-NH2 promoted corneal healing; NK1R knockout or antagonism abolished the effect completely.
How the study worked
Mouse model of neurotrophic keratopathy via trigeminal nerve axotomy. Corneal healing tracked by fluorescein staining and slit-lamp examination. Immunohistofluorescence for substance P, NK-1R, and phospho-Akt. Multiplex cytokine assay for inflammatory markers.
Who was studied
Mice with trigeminal nerve axotomy (neurotrophic keratopathy model)
What this study cannot tell us
Mouse model of neurotrophic keratopathy may not fully replicate human disease. Specific doses and treatment duration details not fully characterized. Long-term effects and optimal treatment protocols need further study.
How to read the evidence
Well-designed animal study with clear mechanistic evidence using receptor antagonist controls. Pre-clinical stage.
When this study was published
Published in 2020. Peptide-based corneal therapies continue to advance toward clinical application.
The bigger picture
Peptide-based eye drops represent a growing frontier in ophthalmology. This mechanistic understanding of how substance P derivatives promote corneal healing could lead to optimized formulations for a condition that currently has few effective treatments.
Questions still open
- Can these peptide eye drops be advanced to human clinical trials for neurotrophic keratopathy?
- Would combining FGLM-NH2/SSSR with other corneal healing agents provide additive benefit?
- Do patients with different causes of neurotrophic keratopathy respond equally to this treatment?
Common questions
What is neurotrophic keratopathy?
How do peptide eye drops differ from regular eye drops?
Read the original research
Role of the Neurokinin-1 Receptor in the Promotion of Corneal Epithelial Wound Healing by the Peptides FGLM-NH2 and SSSR in Neurotrophic Keratopathy.
Investigative ophthalmology & visual science, 61(8), 29
Citation
Yanai, Ryoji; Nishida, Teruo; Hatano, Makoto; Uchi, Sho-Hei; Yamada, Naoyuki; Kimura, Kazuhiro. (2020). Role of the Neurokinin-1 Receptor in the Promotion of Corneal Epithelial Wound Healing by the Peptides FGLM-NH2 and SSSR in Neurotrophic Keratopathy.. Investigative ophthalmology & visual science, 61(8), 29. https://doi.org/10.1167/iovs.61.8.29