Nanophthalmos-Associated MYRF gene mutation facilitates intraocular inflammation in mice.

Abstract

PURPOSE: Patients with nanophthalmos might be prone to developing intraocular inflammation following an acute glaucoma attack. Here, we aimed to investigate the role of MYRF in intraocular inflammation by modeling the mutation in mice. METHODS: Nanophthalmos frameshift mutation of Myrf was introduced into the mouse genome with the CRISPR-Cas9 system. Signaling pathways in eye tissues were delineated using RNA sequencing and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. Intraocular inflammation was induced by a lipopolysaccharide (LPS) intravitreal injection. Dexamethasone (DEX) was administered systemically and locally a week before the LPS injection. The anterior segment clinical scores of the mice were examined 24 h after the LPS injection. Infiltrating inflammatory cells were evaluated with histopathology and immunofluorescence. The mRNA levels of inflammatory cytokines were quantified with reverse transcription-quantitative PCR (RT-qPCR) and the corresponding protein concentrations using enzyme-linked immunosorbent assay (ELISA). RESULTS: Many inflammation-associated signaling pathways were enriched in Myrfmice ocular tissues. Clinical scores of Myrfmice were significantly higher than those of Myrfmice 24 h after LPS administration. Histological examination demonstrated high inflammatory cell infiltration in the anterior and vitreous chambers in Myrfmice, with numerous CD45and CD11binflammatory cells. Moreover, enhanced expression of inflammatory cytokines MCP-1, TGF-β, and IL-1β in eyes and aqueous humor of Myrfmice was detected. Remarkably, pretreating Myrfmice with DEX relieved the intraocular inflammation. CONCLUSION: Nanophthalmos-associated MYRF mutation renders mouse eyes more susceptible to inflammation. Dexamethasone treatment ameliorates the inflammatory response.