Fabry Disease Rat Model Develops Age- and Sex-Dependent Anterior Segment Ocular Abnormalities.

Purpose: Fabry disease is an X-linked lysosomal storage disorder that results in multi-systemic renal, cardiovascular, and neuropathological damage, including in the eyes. We evaluated anterior segment ocular abnormalities based on age, sex (male and female), and genotype (wild-type, knockout [KO] male, heterozygous [HET] female, and KO female) in a rat model of Fabry disease. Methods: The α-Gal A KO and WT rats were divided into young (6-24 weeks), adult (25-60 weeks), and aged (61+ weeks) groups. Intraocular pressure (IOP) was measured. Eyes were clinically scored for corneal and lens opacity as well as evaluated for corneal epithelial integrity and tear break-up time (TBUT). Anterior chamber depth (ACD) and central corneal thickness (CCT) using anterior segment-optical coherence tomography (AS-OCT). Results: The Fabry rats showed an age-dependent increase in IOP, predominantly in the male genotype. TBUT was decreased in both male and female groups with aging. Epithelial integrity was defective in KO males and HET females with age. However, it was highly compromised in KO females irrespective of age. Corneal and lens opacities were severely affected irrespective of sex or genotype in the aging Fabry rats. AS-OCT quantification of CCT and ACD also demonstrated age-dependent increases but were more pronounced in Fabry versus WT genotypes. Conclusions: Epithelial integrity, corneal, and lens opacities worsened in Fabry rats, whereas IOP and TBUT changes were age-dependent. Similarly, CCT and ACD were age-related but more pronounced in Fabry rats, providing newer insights into the anterior segment ocular abnormalities with age, sex, and genotype in a rat model of Fabry disease.

Mustard gas exposure instigates retinal Müller cell gliosis.

Sulfur mustard (SM) is a chemical warfare agent (CWA) that causes severe eye pain, photophobia, excessive lacrimation, corneal and ocular surface defects, and blindness. However, SM's effects on retinal cells are relatively meager. This study investigated the role of SM toxicity on Müller glial cells responsible for cellular architecture, inner blood-retinal barrier maintenance, neurotransmitter recycling, neuronal survival, and retinal homeostasis. Müller glial cells (MIO-M1) were exposed to SM analog, nitrogen mustard (NM), at varying concentrations (50-500 µM) for 3 h, 24 h, and 72 h. Müller cell gliosis was evaluated using morphological, cellular, and biochemical methods. Real-time cellular integrity and morphological evaluation were performed using the xCELLigence real-time monitoring system. Cellular viability and toxicity were measured using TUNEL and PrestoBlue assays. Müller glia hyperactivity was calculated based on glial fibrillary acidic protein (GFAP) and vimentin immunostaining. Intracellular oxidative stress was measured using DCFDA and DHE cell-based assays. Inflammatory markers and antioxidant enzyme levels were determined by quantitative real-time PCR (qRT-PCR). AO/Br and DAPI staining further evaluated DNA damage, apoptosis, necrosis, and cell death. Inflammasome-associated Caspase-1, ASC, and NLRP3 were studied to identify mechanistic insights into NM toxicity in Müller glial cells. The cellular and morphological evaluation revealed the Müller glia hyperactivity after NM exposure in a dose- and time-dependent manner. NM exposure caused significant oxidative stress and enhanced cell death at 72 h. A significant increase in antioxidant indices was observed at the lower concentrations of NM. Mechanistically, we found that NM-treated MIO-M1 cells increased caspase-1 levels that activated NLRP3 inflammasome-induced production of IL-1ß and IL-18, and elevated Gasdermin D (GSDMD) expression, a crucial component actuating pyroptosis. In conclusion, NM-induced Müller cell gliosis via increased oxidative stress results in caspase-1-dependent activation of the NLRP3 inflammasome and cell death driven primarily by pyroptosis.