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Veterinary ophthalmology2022; 26 Suppl 1(Suppl 1); 125-133; doi: 10.1111/vop.13042

Identification of putative orthologs of clinically relevant antimicrobial peptides in the equine ocular surface and amniotic membrane.

Abstract: This study aimed to define the antimicrobial peptide (AMP) expression pattern of the equine ocular surface and amniotic membrane using a targeted qPCR approach and 3'Tag-sequencing. It will serve as a reference for future studies of ocular surface innate immunity and amniotic membrane therapies. Methods: A targeted qPCR approach was used to investigate the presence of orthologs for three of the most highly expressed beta-defensins (DEFB1, DEFB4B, and DEFB103A) of the human ocular surface and amniotic membrane in equine corneal epithelium, conjunctiva, and amniotic membrane. 3'Tag-sequencing was performed on RNA from one sample of corneal epithelium, conjunctiva, and amniotic membrane to further characterize their AMP expression. Results: Equine corneal epithelium, conjunctiva, and amniotic membrane expressed DEFB1, DEFB4B, and DEFB103A. DEFB103A was expressed at the highest amounts in corneal epithelium, while DEFB4B was most highly expressed in conjunctiva and amniotic membrane. 3'Tag-sequencing from all three tissues confirmed these findings and identified expression of five additional beta-defensins, 11 alpha-defensins and two cathelicidins, with the alpha-defensins showing higher normalized read counts than the beta-defensins. Conclusions: This study identified AMP expression in the equine cornea and conjunctiva, suggesting that they play a key role in the protection of the equine eye, similar to the human ocular surface. We also determined that equine amniotic membrane expresses a substantial number of AMPs suggesting it could potentiate an antimicrobial effect as a corneal graft material. Future studies will focus on defining the antimicrobial activity of these AMPs and determining their role in microbial keratitis.
© 2022 The Authors. Veterinary Ophthalmology published by Wiley Periodicals LLC on behalf of American College of Veterinary Ophthalmologists.
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Publication Date: 2022-12-07 PubMed ID: 36478371PubMed Central: PMC10175123DOI: 10.1111/vop.13042Google Scholar: Lookup
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  • Journal Article

Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

The research examines the presence of antimicrobial peptides (AMPs) -specifically, orthologs of human beta-defensins- in certain parts of horse anatomy such as the eye and the amniotic membrane. The aim was to establish a foundation for understanding innate immunity in these areas and the potential therapeutic uses of the amniotic membrane.

Methods

  • This research employed a precisely targeted quantitative PCR (qPCR) method to look for orthologs of three highly expressed human beta-defensins (DEFB1, DEFB4B, and DEFB103A).
  • These defensins were being searched for in the equine corneal epithelium, conjunctiva, and the amniotic membrane.
  • Additionally, 3’Tag-sequencing of RNA from one sample from each of these three areas was carried out. This was done to widen the characterization of AMP expression.

Results

  • All the three tissues examined (corneal epithelium, conjunctiva, and amniotic membrane) showed the presence of DEFB1, DEFB4B, and DEFB103A.
  • Of the three, DEFB103A showed the highest expression levels in the corneal epithelium, and DEFB4B was found in larger amounts in the conjunctiva and amniotic membrane.
  • The 3’Tag-sequencing supported these discoveries and additionally detected five more beta-defensins, 11 alpha-defensins, and two cathelicidins. It also revealed that the alpha-defensins were expressed more than the beta-defensins.

Conclusions

  • The research concluded that AMPs are present in the equine cornea and conjunctiva, suggesting that they likely have a significant role in protecting the equine eye, as they do in humans.
  • It was also established that the equine amniotic membrane expresses a considerable number of AMPs. This suggests that it could potentially provide an antimicrobial effect if used as corneal graft material.
  • Future investigations will aim at defining the antimicrobial properties of these AMPs and determining their role in bacterial keratitis.

Cite This Article

APA
Hisey EA, Martins BC, Donnelly CG, Cassano JM, Katzman SA, Murphy CJ, Thomasy SM, Leonard BC. (2022). Identification of putative orthologs of clinically relevant antimicrobial peptides in the equine ocular surface and amniotic membrane. Vet Ophthalmol, 26 Suppl 1(Suppl 1), 125-133. https://doi.org/10.1111/vop.13042

Publication

Veterinary ophthalmology
ISSN: 1463-5224
NlmUniqueID: 100887377
Country: England
Language: English
Volume: 26 Suppl 1
Issue: Suppl 1
Pages: 125-133

Researcher Affiliations

Hisey, Erin A
  • Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California-Davis, Davis, CA, USA.
Martins, Bianca C
  • Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California-Davis, Davis, CA, USA.
Donnelly, Callum G
  • Department of Population Health and Reproduction, School of Veterinary Medicine, University of California-Davis, Davis, CA, USA.
Cassano, Jennifer M
  • Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California-Davis, Davis, CA, USA.
Katzman, Scott A
  • Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California-Davis, Davis, CA, USA.
Murphy, Christopher J
  • Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California-Davis, Davis, CA, USA.
  • Department of Ophthalmology and Vision Science, School of Medicine, University of California Davis, Davis, CA, USA.
Thomasy, Sara M
  • Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California-Davis, Davis, CA, USA.
  • Department of Ophthalmology and Vision Science, School of Medicine, University of California Davis, Davis, CA, USA.
Leonard, Brian C
  • Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California-Davis, Davis, CA, USA.

MeSH Terms

  • Humans
  • Animals
  • Horses
  • beta-Defensins / genetics
  • beta-Defensins / metabolism
  • alpha-Defensins / metabolism
  • Amnion / metabolism
  • Cornea / metabolism
  • Conjunctiva / metabolism
  • Anti-Infective Agents

Grant Funding

  • K08EY028199 / NEI NIH HHS
  • K08 EY028199 / NEI NIH HHS
  • S10 OD010786 / NIH HHS
  • 5K08EY028199 / NEI NIH HHS
  • T32 GM136559 / NIGMS NIH HHS

Conflict of Interest Statement

CONFLICT OF INTEREST. The authors have no financial interests to disclose.

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Citations

This article has been cited 2 times.
  1. Rayat Pisheh H, Darvishi A, Masoomkhah SS. Amniotic membrane, a novel bioscaffold in cardiac diseases: from mechanism to applications. Front Bioeng Biotechnol 2024;12:1521462.
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  2. Hisey EA, Wong S, Park S, Gamarra KA, Adelman SA, Knickelbein KE, Quan M, Ferneding MH, McCorkell M, Daley N, Ureno V, Le S, Ardon M, Williams L, Puentes B, Bowman M, Motta MJ, Pham HQH, Wilkerson A, Yuksel S, Jester JV, Thomasy SM, Morgan JT, Butovich IA, Leonard BC. Meibomian gland lipid alterations and ocular surface sequela in Awat2 knockout murine model of meibomian gland dysfunction and evaporative dry eye disease. Ocul Surf 2024 Oct;34:489-503.
    doi: 10.1016/j.jtos.2024.10.003pubmed: 39414024google scholar: lookup
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