The study successfully constructed an Angpt2-miR-145 mouse model carrying the rs76020419 (G>T) mutation, confirming this mutation elevates ANGPT2 expression while expanding the Schlemm’s Canal region, suggesting its protective role in glaucoma. This model provides a critical tool for future investigations into ANGPT2’s function in intraocular pressure regulation and retinal neurodegeneration.
Literature Overview
This article, 'A Glaucoma-Protective Human SNP in the Angpt2 Locus,' published in the journal Arteriosclerosis, Thrombosis, and Vascular Biology, reviews functional validation studies of rs76020419 (G>T), a human SNP located in the miR-145 binding site within the ANGPT2 3’UTR. This mutation has been associated with reduced intraocular pressure and lower risk of primary open-angle glaucoma in genome-wide association studies (GWAS), and functions as an expression quantitative trait locus (eQTL) linked to upregulated ANGPT2 expression in the GTEx database. The research team employed CRISPR/Cas9 technology to develop a murine model harboring this SNP and evaluated ANGPT2 expression and Schlemm’s Canal morphological changes across ocular and systemic tissues.
Background Knowledge
Glaucoma is a leading cause of irreversible blindness globally, affecting approximately 60 million individuals. Maintaining aqueous humor production and drainage balance is critical for intraocular pressure (IOP) regulation, with the trabecular meshwork (TM) and Schlemm’s Canal (SC) serving as primary drainage pathways. Previous studies revealed that loss-of-function mutations in ANGPT1 and TEK genes cause congenital glaucoma, whereas ANGPT2 may partially compensate for ANGPT1 deficiency. miR-145, a known ANGPT2 inhibitor, interacts with this binding site; the rs76020419 (G>T) SNP disrupts this inhibition, leading to elevated ANGPT2 expression that potentially increases SC caliber and reduces IOP. Prior to this study, no in vivo mouse model existed to validate these mechanisms, making this research a pioneering contribution that directly demonstrates ANGPT2’s protective role in SC homeostasis and glaucoma prevention.
Research Methods and Experiments
The research team introduced the rs76020419 (G>T) mutation into C57BL/6 mice using CRISPR/Cas9 technology to generate the Angpt2-miR-145 mouse model. ANGPT2 protein levels were quantified in plasma and tissues (ocular, pulmonary, renal) through qPCR and ELISA. Immunofluorescence staining combined with confocal microscopy analyzed SC regional area changes, while intraocular pressure (IOP) was measured using Tonolab rebound tonometry. Fluorescent angiography assessed vascular leakage to ensure model stability.
Key Conclusions and Perspectives
Research Significance and Prospects
The findings establish a functional relationship between elevated ANGPT2 expression and structural modifications in Schlemm’s Canal, supporting its potential as a genetic protective factor against glaucoma. Future studies should combine this mutation with multiple ocular hypertension models to evaluate its protective effects against elevated IOP and retinal neurodegeneration, laying the groundwork for ANGPT2/miR-145-targeted therapeutic strategies.
Conclusion
This study represents the first validation in a murine model of human ANGPT2 gene mutation rs76020419 (G>T) and its impact on intraocular pressure and Schlemm’s Canal morphology. Using CRISPR/Cas9 editing, the research team successfully developed a mouse model carrying this mutation and confirmed ANGPT2 protein upregulation across multiple tissues. The observed SC enlargement and reduced IOP in mutant mice provide in vivo evidence for miR-145’s regulatory role in ANGPT2 expression. This model establishes a foundation for investigating ANGPT2’s protective mechanisms in glaucoma and related neurodegenerative diseases, while identifying novel molecular targets for gene therapy.
