Comprehensive multiomics analyses identify guanylate cyclase activator 1A as a photoreceptor-specific target in a murine model of oxygen-induced retinopathy

BACKGROUND: Retinopathy of prematurity (ROP), the leading cause of childhood blindness, is considered a vascular retinopathy; however, clinical studies have reported persistent electrophysiological dysfunctions in some ROP patients with remitted vasculopathy, resulting in severe visual impairments. Therefore, this study sought to unravel the mechanisms underlying persistent electrophysiological dysfunctions and identify a neuronal target in a murine model of oxygen-induced retinopathy (OIR), a widely used animal model for ROP. METHODS: Retinal vascular morphology and leakage were examined by isolectin B4 staining and fluorescein fundus angiography in the OIR mouse model at P17 and P25. Full-field electroretinogram (ERG) was performed. Moreover, P17 retinas were analyzed with metabolomics and transcriptomics, and the results were validated by quantitative PCR (qPCR) and Western blotting (WB). Whole-cell patch clamp was used to evaluate phototransduction. Lentiviral particles carrying guanylate cyclase activator 1A (Guca1a) cDNA driven by a mouse rod opsin promoter were intravitreally injected into OIR mice, and immunofluorescence, ERG, patch clamp, cGMP measurement, and TUNEL staining were performed for assessments. RESULTS: Vascular lesions in OIR retinas peaked at P17 and recovered at P25. However, a wave and b wave amplitudes in dark- and light-adapted ERGs under all light intensities were deficient at both developmental stages, and electrophysiological dysfunctions persisted in P32 OIR retinas. Multiomics indicates phototransduction defects in isolated photoreceptors. QPCR and WB validated the reduced Guca1a mRNA and its encoding protein levels in P17 and P25 OIR retinas. Patch clamp demonstrated impaired light responses of single rods. Furthermore, lentivirus-mediated photoreceptor-specific expression of GUCA1A recovered electrophysiological functions, improved single rod phototransduction, increased cGMP concentration, and reduced cell death in P17 and P25 OIR retinas. CONCLUSIONS: The reduced GUCA1A in photoreceptors is mainly responsible for persistent electrophysiological dysfunctions in OIR mouse retinas, even after the recovery of vessel damage. The photoreceptor GUCA1A may serve as a neuronal target for ROP intervention.