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Updated: May 3, 2026

Oxygen-Induced Retinopathy Model for Ischemic Retinal Diseases in Rodents
Published on: September 16, 2020
[Overexpression of 15-lipoxygenase-1 inhibits oxygen-induced retinal neovascularization in mice]
Objective:
To investigate the mechanism and inhibitory effects of overexpression of 15-lipoxygenase-1 inhibiting oxygen-induced retinal neovascularization in mice.
Methods:
Experimental study. Eighty-eight 7-day-old C57BL/6J mice were randomly divided into the normal control group, induced model group, gene treated group and empty vector group with 22 mice in each group. The mice with their mothers were arisen in 75% ± 2% O₂ environment for 5 days and then returned to normoxia for 5 days to establish the oxygen-induced retinopathy (OIR) model. At postnatal day 12, the gene treated group was received an intravitreous injection of Ad-15-LOX-1-EGFP at 1.0 µl, while the empty vector group was received the same volume of Ad-EGFP. At postnatal day 17, real-time PCR and Western Blot methods were used to detect the mRNA and protein expression levels of 15-LOX-1, peroxisome proliferator-activated receptor γ (PPAR-γ) , vascular endothelial growth factor-A (VEGF-A) and vascular endothelial growth factor receptor 2 (VEGFR-2) in the retina. The relative retinal non-perfusion and neovascularization areas were evaluated by FITC-dextran fluorescein angiography on flat-mounted retina. The number of endothelial cell nuclei breaking through the inner limiting membrane (ILM) was counted on hematoxylin and eosin-stained retinal section. Rank sum test and one-way ANOVA were used to assess statistical significance within groups.
Results:
The 15-LOX-1 and PPAR-γ mRNA and protein expression levels were higher in gene treated group (15-LOX-1: 2.17 ± 0.25, 1.45 ± 0.10;PPAR-γ:2.12 ± 0.29, 0.85 ± 0.03) than those in induced model group (15-LOX-1:0.62 ± 0.03, 0.66 ± 0.04; PPAR-γ:0.67 ± 0.18, 0.48 ± 0.03) and empty vector group (15-LOX-1:0.51 ± 0.14,0.57 ± 0.03;PPAR-γ:1.07 ± 0.09,0.52 ± 0.02) ( t15-LOX-1 = 12.511, 13.402, both P < 0.01; tPPAR-r = 9.420, 6.813, both P < 0.01). On the contrary,VEGF-A and VEGFR-2 expression levels were lower in gene treated group (
Vegf-A:
0.87 ± 0.07, 0.34 ± 0.01; VEGFR-2:1.02 ± 0.12, 0.45 ± 0.03) than those in induced model group (
Vegf-A:
3.49 ± 0.53,0.74 ± 0.04; VEGFR-2:2.28 ± 0.44, 0.82 ± 0.01) and empty vector group (
Vegf-A:
2.30 ± 0.25,0.69 ± 0.02; VEGFR-2:1.88 ± 0.16, 0.76 ± 0.03) (tVEGF-A = 10.662, 5.843, both P < 0.01; tVEGFR-2 = 6.731, 4.763, both P < 0.01). The relative retinal non-perfusion and neovascularization areas were significantly smaller, and the number of endothelial cell nuclei breaking through the ILM was obviously lower in gene treated group(5.88 ± 1.12; 9.37 ± 1.85; 1.25 ± 0.89) than those in induced model group (21.25 ± 2.87; 24.13 ± 4.29; 60.63 ± 10.82) and empty vector group (19.50 ± 1.78; 23.13 ± 3.52; 54.63 ± 7.63) (P < 0.01; P < 0.01).
Conclusion:
Overexpression of 15-LOX-1 inhibits ORI neovascularization in mice via up-regulation of PPAR-γ and down-regulation of VEGF-A and VEGFR-2 expression.
Insights
Overexpression of 15-lipoxygenase-1 (15-LOX-1) effectively inhibits oxygen-induced retinopathy (OIR) in mice. This occurs through increased PPAR-γ and decreased VEGF-A/VEGFR-2, reducing retinal neovascularization.
Area of Science:
- Ophthalmology
- Molecular Biology
- Genetics
Context:
- Oxygen-induced retinopathy (OIR) is a significant cause of vision impairment.
- Understanding the molecular mechanisms of OIR is crucial for developing effective treatments.
- 15-lipoxygenase-1 (15-LOX-1) has emerged as a potential therapeutic target.
Purpose:
- To investigate the mechanism by which 15-LOX-1 overexpression inhibits OIR.
- To evaluate the inhibitory effects of 15-LOX-1 on oxygen-induced retinal neovascularization in a mouse model.
Summary:
- Mice with OIR were treated with Ad-15-LOX-1-EGFP to overexpress 15-LOX-1.
- Real-time PCR and Western Blot analysis revealed increased 15-LOX-1 and PPAR-γ, and decreased VEGF-A and VEGFR-2 expression in the treated group.
- FITC-dextran angiography and histological analysis showed significantly reduced retinal non-perfusion and neovascularization areas.
Impact:
- This study elucidates the inhibitory role of 15-LOX-1 in OIR.
- The findings suggest that 15-LOX-1 overexpression, via PPAR-γ modulation, offers a potential therapeutic strategy for OIR.
- This research contributes to the development of novel treatments for neovascular eye diseases.

