Substance P-Derived Peptide Eye Drops Heal Corneal Wounds Through NK-1 Receptor and Akt Signaling

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.

Yanai, Ryoji et al.·Investigative ophthalmology & visual science·2020·Moderate Evidenceanimal
RPEP-05212AnimalModerate Evidence2020RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
animal
Evidence
Moderate Evidence
Sample
N=Not specified (mouse study with multiple genetic groups)
Participants
Mice with trigeminal nerve axotomy (neurotrophic keratopathy model)

What This Study 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.

Key Numbers

FGLM-NH2 promoted corneal healing; NK1R knockout or antagonism abolished the effect completely.

How They Did This

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.

Why This Research 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 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.

What This Study Doesn't 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.

Questions This Raises

  • ?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?

Trust & Context

Key Stat:
NK-1R receptor identified as the key mediator of peptide-driven corneal wound healing
Evidence Grade:
Well-designed animal study with clear mechanistic evidence using receptor antagonist controls. Pre-clinical stage.
Study Age:
Published in 2020. Peptide-based corneal therapies continue to advance toward clinical application.
Original Title:
Role of the Neurokinin-1 Receptor in the Promotion of Corneal Epithelial Wound Healing by the Peptides FGLM-NH2 and SSSR in Neurotrophic Keratopathy.
Published In:
Investigative ophthalmology & visual science, 61(8), 29 (2020)
Database ID:
RPEP-05212

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled Trial
Cohort / Case-Control
Cross-Sectional / ObservationalSnapshot without intervening
This study
Case Report / Animal Study
What do these levels mean? →

Frequently Asked Questions

What is neurotrophic keratopathy?

A condition where damage to the trigeminal nerve impairs the cornea's ability to sense and heal itself, potentially leading to ulcers, scarring, and vision loss.

How do peptide eye drops differ from regular eye drops?

Peptide eye drops contain specific protein fragments that actively signal cells to heal, rather than just moisturizing or reducing inflammation like conventional drops.

Read More on RethinkPeptides

Cite This Study

RPEP-05212·https://rethinkpeptides.com/research/RPEP-05212

APA

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

MLA

Yanai, Ryoji, et al. "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, 2020. https://doi.org/10.1167/iovs.61.8.29

RethinkPeptides

RethinkPeptides Research Database. "Role of the Neurokinin-1 Receptor in the Promotion of Cornea..." RPEP-05212. Retrieved from https://rethinkpeptides.com/research/yanai-2020-role-of-the-neurokinin1

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.