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Updated: May 9, 2025
Measuring Retinal Vessel Diameter from Mouse Fluorescent Angiography Images
Published on: May 19, 2023
BARD1-mediated stabilization of METTL14 promotes retinal neovascularization by m6A-modifying MXD1 mRNA on a
Xianyang Liu1,2, Shuhao Zeng2, Jiayu Meng3
1The First Affiliated Hospital of Chongqing Medical University, China.
Abstract:
Retinal vascular diseases are typified by the proliferation of irregular and leaky microvessels, resulting in vision impairment. Although the etiology of retinal angiogenesis is not yet fully understood, it is evident that microglia play a pivotal role in promoting angiogenesis. Methods: In vivo, the METTL14 conditional knockout (cKO) mouse was constructed to investigate the role of METTL14 in oxygen-induced retinopathy (OIR). In vitro, a combination of methylated RNA immunoprecipitation sequencing (MeRIP-seq), RNA-sequencing (RNA-seq), RNA Immunoprecipitation (RIP) assay, dual-luciferase reporter assays, and Chromatin immunoprecipitation-qPCR (ChIP-qPCR), was performed to explore the underlying mechanisms. Results: The proteomic analysis of hypoxic microglia has uncovered a pronounced enrichment in pathways related to RNA modification. Western blot has revealed that N6-methyladenosine (m6A) methyltransferase-like 14 (METTL14) exhibits the most significant increase among the RNA methylases. METTL14 cKO mice within an OIR model showed fewer neovascular formations. Additionally, in co-culture with sh-METTL14 HMC3 cells, HRMECs also exhibited reduced angiogenesis capabilities. Mechanically, E3 ubiquitin-protein ligase BARD1 can directly interact with METTL14, leading to an up-regulation of METTL14 protein level in hypoxic microglia. METTL14 could directly modifies and regulates the transcription factor MAX Dimerization Protein 1 (MXD1), which is subsequently recognized by the m6A "reader" YTH domain-containing family protein 2 (YTHDF2). Consequently, the modified MXD1 modulates the expression of VEGFA and VCAM1, promotes retinal neovascularization. Conclusion: Our study highlights the critical role of METTL14 in the OIR model and suggests a novel therapeutic target for addressing retinal vascular diseases.
Insights
METTL14 promotes retinal neovascularization by regulating MXD1, VEGFA, and VCAM1. Inhibiting METTL14 may offer a new treatment for retinal vascular diseases like OIR.
Area of Science:
- Ophthalmology
- Molecular Biology
- Cell Biology
Background:
- Retinal vascular diseases involve abnormal microvessel growth, leading to vision loss.
- Microglia are key players in promoting retinal angiogenesis.
- The precise molecular mechanisms driving retinal angiogenesis remain incompletely understood.
Purpose of the Study:
- To investigate the role of N6-methyladenosine (m6A) methyltransferase-like 14 (METTL14) in oxygen-induced retinopathy (OIR).
- To elucidate the molecular mechanisms by which METTL14 influences retinal angiogenesis.
Main Methods:
- Oxygen-induced retinopathy (OIR) mouse model with METTL14 conditional knockout (cKO).
- In vitro studies using HMC3 and HRMEC cell lines.
- Techniques included MeRIP-seq, RNA-seq, RIP assay, dual-luciferase reporter assays, and ChIP-qPCR.
Main Results:
- Hypoxic microglia showed enriched RNA modification pathways, with METTL14 significantly upregulated.
- METTL14 cKO mice exhibited reduced neovascularization in the OIR model.
- METTL14 directly modifies transcription factor MXD1, influencing VEGFA and VCAM1 expression, thereby promoting retinal neovascularization.
Conclusions:
- METTL14 plays a critical role in promoting retinal neovascularization in the OIR model.
- The METTL14-MXD1-VEGFA/VCAM1 pathway is a key mechanism in retinal angiogenesis.
- METTL14 represents a potential novel therapeutic target for retinal vascular diseases.
