Retinal Imaging Analysis and Proteomic Profiling Reveals Sexual Dimorphism in the Retina of C57BL6/J Mice

Abstract

Purpose : Sex is a risk factor for the development of vision threatening diseases such as age-related macular degeneration, diabetic retinopathy and glaucoma. The molecular mechanism(s) that underly these sexually dimorphic changes are currently unknown. We evaluated the sexual dimorphism of adult mouse retina under physiological and pathological (laser-induced CNV) conditions and quantified differentially expressed proteins in the RPE and retina of male and female adult mice.

Methods : Male and female C57BL/6J wild-type mice at 4 months of age were imaged using Confocal Scanning Laser Ophthalmoscope (cSLO) and Optical Coherence Tomography (OCT). OCT automated mouse retina segmentation software was used to quantitate retinal thickness.
To further investigate sexual dimorphism under pathological conditions, the laser induced choroidal neovascularization (CNV) mouse model was utilized. cSLO images were taken 3 days post injury and ICGA area leakage from lesions were measured.
Quantitative proteomics of male and female C57BL/6J wild-type mice (n=10 males, n=10 females) was conducted using isobaric tags for relative and absolute quantification (iTRAQ). Gene Ontology (GO) analysis and Ingenuity Pathway Analysis (IPA) was performed on differentially expressed proteins.

Results : Under physiological conditions, female mice exhibited increased retinal thickness compared to their male counterparts. Specifically, the inner (RNFL-INL) and middle layers (OPL-ONL) showed increased thickness. Female mice exhibited increased ICGA dye leakage from CNV lesions compared to male counterparts at 3 days post laser injury. Quantitative proteomics identified differential expression of proteins in the mouse retina and RPE. The top molecular and cellular functions identified were lipid metabolism, molecular transport, amino acid metabolism and cell death and survival in the retina and cellular assembly and organization, protein synthesis, cellular function and maintenance, cell morphology and cellular movement in the RPE.

Conclusions : Researchers should be cognizant of the influence sex has on ocular diseases when utilizing murine mouse models.

This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.