Related Experiment Video
Updated: Aug 13, 2025
A Protocol to Evaluate and Quantify Retinal Pigmented Epithelium Pathologies in Mouse Models of Age-Related Macular Degeneration
Published on: March 10, 2023
An SPM-Enriched Marine Oil Supplement Shifted Microglia Polarization toward M2, Ameliorating Retinal Degeneration in
Lorena Olivares-González1, Sheyla Velasco1, Idoia Gallego2,3,4
1Group of Pathophysiology and Therapies for Vision Disorders, Príncipe Felipe Research Center (CIPF), 46012 Valencia, Spain.
Abstract:
Retinitis pigmentosa (RP) is the most common inherited retinal dystrophy causing progressive vision loss. It is accompanied by chronic and sustained inflammation, including M1 microglia activation. This study evaluated the effect of an essential fatty acid (EFA) supplement containing specialized pro-resolving mediators (SPMs), on retinal degeneration and microglia activation in rd10 mice, a model of RP, as well as on LPS-stimulated BV2 cells. The EFA supplement was orally administered to mice from postnatal day (P)9 to P18. At P18, the electrical activity of the retina was examined by electroretinography (ERG) and innate behavior in response to light were measured. Retinal degeneration was studied via histology including the TUNEL assay and microglia immunolabeling. Microglia polarization (M1/M2) was assessed by flow cytometry, qPCR, ELISA and histology. Redox status was analyzed by measuring antioxidant enzymes and markers of oxidative damage. Interestingly, the EFA supplement ameliorated retinal dysfunction and degeneration by improving ERG recording and sensitivity to light, and reducing photoreceptor cell loss. The EFA supplement reduced inflammation and microglia activation attenuating M1 markers as well as inducing a shift to the M2 phenotype in rd10 mouse retinas and LPS-stimulated BV2 cells. It also reduced oxidative stress markers of lipid peroxidation and carbonylation. These findings could open up new therapeutic opportunities based on resolving inflammation with oral supplementation with SPMs such as the EFA supplement.
Insights
An essential fatty acid (EFA) supplement reduced retinal degeneration and inflammation in a mouse model of retinitis pigmentosa (RP). This specialized pro-resolving mediator (SPM) therapy improved vision and photoreceptor survival.
Area of Science:
- Ophthalmology
- Neuroscience
- Immunology
Background:
- Retinitis pigmentosa (RP) is a leading cause of inherited blindness, characterized by progressive vision loss and retinal inflammation.
- M1 microglia activation is a key inflammatory component in RP, contributing to photoreceptor degeneration.
Purpose of the Study:
- To investigate the therapeutic potential of an essential fatty acid (EFA) supplement containing specialized pro-resolving mediators (SPMs) in a mouse model of RP (rd10 mice).
- To evaluate the supplement's effects on retinal degeneration, microglia activation, and oxidative stress.
Main Methods:
- Oral administration of EFA supplement to rd10 mice from postnatal day 9 to 18.
- Assessment of retinal function using electroretinography (ERG) and light-based behavioral tests.
- Histological analysis of retinal degeneration, photoreceptor cell loss (TUNEL assay), and microglia immunolabeling.
- Evaluation of microglia polarization (M1/M2) via flow cytometry, qPCR, ELISA, and histology.
- Analysis of redox status, including antioxidant enzymes and oxidative damage markers.
Main Results:
- The EFA supplement significantly improved ERG recordings and light sensitivity, indicating amelioration of retinal dysfunction.
- Supplementation reduced photoreceptor cell loss and overall retinal degeneration.
- A decrease in M1 microglia markers and an induction of the M2 phenotype were observed, indicating reduced inflammation.
- Markers of oxidative stress, such as lipid peroxidation and carbonylation, were significantly reduced.
Conclusions:
- Oral EFA supplementation containing SPMs demonstrates therapeutic potential for RP by reducing retinal degeneration and inflammation.
- The EFA supplement shifts microglia towards a pro-resolving M2 phenotype and mitigates oxidative stress.
- These findings suggest a promising therapeutic strategy for RP using SPMs to resolve inflammation.
