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Home / Equine Research Bank / Open Vet J / Evaluation of pigment epithelium-derived factor concentratio...
Open veterinary journal2020; 10(3); 289-296; doi: 10.4314/ovj.v10i3.7

Evaluation of pigment epithelium-derived factor concentration in equine amniotic membrane homogenate and its in-vitro vascular endothelial growth factor inhibition effect in tears of dogs with vascularized ulcerative keratitis.

Abstract: Corneal neovascularization can result from many pathological processes affecting the ocular surface leading to disturbances and opacifications that reduce corneal clarity and may impact vision. In veterinary medicine, the use of topical corticosteroid is contraindicated in the presence of ulcerative keratitis, and there is sparse research regarding safe medical alternatives to inhibit corneal neovascularization in dogs to improve visual outcome. To investigate the pigment epithelium-derived factor (PEDF) concentration in equine amniotic membrane homogenate (EAMH) and its in-vitro vascular endothelial growth factor (VEGF) inhibition in tears of dogs with vascularized ulcerative keratitis. Homogenates from 10 equine amniotic membranes (AM) were analyzed by sandwich enzyme-linked immunosorbent assay (ELISA) for quantification of equine PEDF and VEGF. Forty tear samples were collected from both eyes of dogs diagnosed with vascularized ulcerative keratitis, and 50 samples from healthy dogs. Samples from affected eyes were allocated to G1 - affected undiluted tears; G2 - affected tears diluted with phosphate-buffer solution; G3 - affected tears treated with low-concentrated EAMH; and G4 - affected tears treated with high-concentrated EAMH. Tears from the unaffected contralateral eyes were composed in G5, while G6 was composed by tears from healthy dogs (control). The presence and levels of VEGF were evaluated in all groups by Western blot and ELISA. The PEDF:VEGF ratio in EAMH was 110:1. An increase in VEGF levels was observed in tears from eyes with vascularized corneal ulcers (G1) as well as in contralateral tears (G5), compared to normal dogs (G6). High-concentrated EAMH provided a greater decrease in VEGF levels in-vitro compared to low-concentrated EAMH. EAMHs exhibited high concentrations of PEDF in comparison to VEGF and were able to partially decrease VEGF levels in tears of dogs with vascularized ulcers, in-vitro. Our results suggest that VEGF concentration is elevated in tears of dogs with active vascularized ulcerative keratitis in both affected and contralateral eyes compared to that of healthy dogs.
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Publication Date: 2020-09-03 PubMed ID: 33282700PubMed Central: PMC7703616DOI: 10.4314/ovj.v10i3.7Google Scholar: Lookup
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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 outlines an investigation into the concentration of a growth-inhibiting substance, called pigment epithelium-derived factor (PEDF), in equine amniotic membrane homogenate (EAMH). The study also examines its effect on the growth-promoting substance, vascular endothelial growth factor (VEGF), in the tears of dogs with vascularized ulcerative keratitis (a condition that causes new blood vessels to form in the cornea, causing vision loss).

Experimental Set-Up

  • The researchers started by producing homogenates (a sample of cells that were broken down to release their internal content) from ten equine amniotic membranes (AM).
  • These EAMHs were then analyzed by a method called enzyme-linked immunosorbent assay (ELISA) to quantify the amounts of PEDF and VEGF.
  • They collected 40 tear samples from dogs diagnosed with vascularized ulcerative keratitis.
  • An additional 50 tear samples were collected from healthy dogs to serve as control.

Group Categorization

  • The samples from affected dogs were divided into four groups: G1, G2, G3 and G4 based on different treatments and dilutions.
  • Tears from the unaffected eyes of the same dogs were allocated to G5, forming a comparison group.
  • G6 comprised tears from healthy dogs as a control group.
  • VEGF presence and levels in all groups were investigated using Western blot and ELISA techniques.

Results and Findings

  • The study found the ratio of PEDF to VEGF in EAMH was 110:1.
  • It also noted an increase in VEGF levels in tears from both affected and unaffected eyes of dogs with vascularized corneal ulcers, compared to healthy dogs.
  • The use of high-concentrated EAMH resulted in a larger decrease in VEGF levels when compared to the use of low-concentrated EAMH.
  • The researchers concluded that the EAMHs, rich in PEDF and with the potential to partially decrease VEGF levels, could potentially be explored as a treatment for dogs with vascularized ulcers.

The findings contribute to the scant research available on medical alternatives to inhibit corneal neovascularization in dogs with ulcerative keratitis, and provide a foundation for further investigation on the use of EAMH in the treatment of the condition.

Cite This Article

APA
Villar T, Pascoli AL, Chaulagain S, Fadl-Alla BA, Martins BC. (2020). Evaluation of pigment epithelium-derived factor concentration in equine amniotic membrane homogenate and its in-vitro vascular endothelial growth factor inhibition effect in tears of dogs with vascularized ulcerative keratitis. Open Vet J, 10(3), 289-296. https://doi.org/10.4314/ovj.v10i3.7

Publication

Open veterinary journal
ISSN: 2218-6050
NlmUniqueID: 101653182
Country: Libya
Language: English
Volume: 10
Issue: 3
Pages: 289-296

Researcher Affiliations

Villar, Tatiane
  • Department of Veterinary Clinical Medicine, College of Veterinary Medicine, University of Illinois, Urbana-Champaign, IL 61802, USA.
Pascoli, Ana L
  • Department of Veterinary Clinical Medicine, College of Veterinary Medicine, University of Illinois, Urbana-Champaign, IL 61802, USA.
Chaulagain, Sabal
  • Department of Pathobiology, College of Veterinary Medicine, University of Illinois, Urbana-Champaign, IL 61802, USA.
Fadl-Alla, Bahaa A
  • Department of Pathobiology, College of Veterinary Medicine, University of Illinois, Urbana-Champaign, IL 61802, USA.
Martins, Bianca C
  • Department of Veterinary Clinical Medicine, College of Veterinary Medicine, University of Illinois, Urbana-Champaign, IL 61802, USA.
  • Current address: Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, CA 95616, USA.

MeSH Terms

  • Amnion / chemistry
  • Amnion / drug effects
  • Animals
  • Corneal Ulcer / drug therapy
  • Corneal Ulcer / veterinary
  • Dog Diseases / drug therapy
  • Dogs
  • Eye Proteins / administration & dosage
  • Horses
  • Nerve Growth Factors / administration & dosage
  • Serpins / administration & dosage
  • Tears / drug effects
  • Vascular Endothelial Growth Factor A / administration & dosage

Conflict of Interest Statement

The authors declare that there is no conflict of interest.

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