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Updated: Mar 3, 2026
A Mouse Model for Laser-induced Choroidal Neovascularization
Published on: December 27, 2015
Different distributions of M1 and M2 macrophages in a mouse model of laser-induced choroidal neovascularization
Yedi Zhou1, Shigeo Yoshida1, Yuki Kubo1
1Department of Ophthalmology, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812‑8582, Japan.
Abstract:
Choroidal neovascularization (CNV) is a serious complication of age‑related macular degeneration. The aim of the present study was to investigate the expression and distribution of M1 and M2 macrophages in a laser‑induced CNV adult mouse model. The mRNA expression levels of M1, M2 and pan macrophage markers, and macrophage‑associated angiogenic cytokines, were determined by reverse transcription‑quantitative polymerase chain reaction. Immunofluorescence studies were performed to determine the location of the macrophages. The expression levels of M1 macrophage markers increased to a greater extent compared with M2 markers in the retinal pigment epithelium (RPE)‑choroid complexes following laser photocoagulation. By contrast, the expression levels of M2 macrophage markers increased primarily in the retinas. Immunofluorescence studies revealed that the increased number of cluster of differentiation (CD)206‑positive cells were located primarily in the retina, whereas the CD80‑positive cells were located around the site of CNVs in the RPE‑choroid. In addition, the M1‑associated cytokines increased to a greater extent in the RPE‑choroid complexes, whereas the M2‑associated cytokines were highly expressed in the retinas. These findings indicate that M1 and M2 macrophage numbers increased following CNV; however, the locations were different in this mouse model of laser‑induced CNV. The results of the present study suggest that M1 macrophages have a more direct role in inhibiting the development of CNV.
Insights
M1 macrophages, crucial for inhibiting choroidal neovascularization (CNV), are concentrated around CNV sites. M2 macrophages, however, are primarily found in the retina, indicating distinct roles in this age-related macular degeneration complication.
Area of Science:
- Ophthalmology
- Immunology
- Cell Biology
Background:
- Choroidal neovascularization (CNV) is a significant cause of vision loss associated with age-related macular degeneration.
- Macrophage polarization into M1 and M2 subtypes plays a critical role in inflammatory and repair processes, including neovascularization.
Purpose of the Study:
- To investigate the differential expression and distribution of M1 and M2 macrophages in a laser-induced CNV mouse model.
- To elucidate the roles of macrophage subtypes and associated cytokines in the pathogenesis of CNV.
Main Methods:
- Laser-induced CNV model in adult mice.
- Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) for gene expression analysis of macrophage markers and cytokines.
- Immunofluorescence staining to determine macrophage localization (CD80 for M1, CD206 for M2).
Main Results:
- Both M1 and M2 macrophage markers showed increased expression following laser-induced CNV.
- M1 markers and associated cytokines were predominantly upregulated in the retinal pigment epithelium (RPE)-choroid complex, particularly around CNV sites.
- M2 markers and associated cytokines were primarily increased in the retina, with CD206-positive cells localized mainly in the retina.
- CD80-positive cells (M1) were found around the CNV sites in the RPE-choroid.
Conclusions:
- M1 and M2 macrophages exhibit distinct spatial distributions in the context of laser-induced CNV.
- M1 macrophages, localized around CNV lesions, appear to play a more direct inhibitory role in CNV development.
- Understanding macrophage polarization and localization is crucial for developing targeted therapies for CNV.
