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Sema4D Knockout Attenuates Choroidal Neovascularization by Inhibiting M2 Macrophage Polarization Via Regulation of
Kaixuan Cui1, Xiaoyu Tang1, Boyu Yang1
1State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China.
Purpose:
The aim of this study was to elucidate the role of Sema4D in the pathogenesis of senescence-associated choroidal neovascularization (CNV) and to explore its underlying mechanisms.
Methods:
In this study, we utilized a model of laser-induced CNV in both young (3 months old) and old (18 months old) mice, including those with or without Sema4D knockout. The expression and localization of Sema4D in CNV were assessed using PCR, Western blot, and immunostaining. Subsequently, the morphological and imaging examinations were used to evaluate the size of CNV and vascular leakage. Finally, the expression of M2 markers, senescence-related markers, and molecules involved in the RhoA/ROCK pathway was detected.
Results:
We found that Sema4D was predominantly expressed in macrophages within CNV lesions, and both the mRNA and protein levels of Sema4D progressively increased following laser photocoagulation, a trend more pronounced in old mice. Moreover, Sema4D knockout markedly inhibited M2 polarization in senescent macrophages and reduced the size and leakage of CNV, particularly in aged mice. Mechanistically, aging was found to upregulate RhoA/ROCK signaling, and knockout of Sema4D effectively suppressed the activation of this pathway, with more significant effects observed in aged mice.
Conclusions:
Our findings revealed that the deletion of Sema4D markedly inhibited M2 macrophage polarization through the suppression of the RhoA/ROCK pathway, ultimately leading to the attenuation of senescence-associated CNV. These data indicate that targeting Sema4D could offer a promising approach for gene editing therapy in patients with neovascular age-related macular degeneration.
Insights
Sema4D promotes senescence-associated choroidal neovascularization (CNV) by enhancing M2 macrophage polarization via the RhoA/ROCK pathway. Targeting Sema4D may offer a novel gene therapy for age-related macular degeneration.
Area of Science:
- Ophthalmology
- Immunology
- Molecular Biology
Background:
- Senescence-associated choroidal neovascularization (CNV) is a significant cause of vision loss.
- The role of Semaphorin 4D (Sema4D) in CNV pathogenesis, particularly in aged individuals, remains unclear.
Purpose of the Study:
- To investigate the role of Sema4D in senescence-associated CNV.
- To elucidate the underlying molecular mechanisms involving macrophage polarization and the RhoA/ROCK pathway.
Main Methods:
- Laser-induced CNV model in young and old mice, with and without Sema4D knockout.
- Assessment of Sema4D expression (PCR, Western blot, immunostaining).
- Evaluation of CNV size, vascular leakage, M2 markers, senescence markers, and RhoA/ROCK pathway activation.
Main Results:
- Sema4D expression increased in CNV lesions, especially in aged mice.
- Sema4D knockout reduced CNV size and leakage, inhibiting M2 macrophage polarization.
- Sema4D deficiency suppressed RhoA/ROCK pathway activation, particularly in aged mice.
Conclusions:
- Sema4D deletion attenuates senescence-associated CNV by inhibiting M2 macrophage polarization via the RhoA/ROCK pathway.
- Targeting Sema4D presents a potential therapeutic strategy for neovascular age-related macular degeneration.
