Mustard gas exposure instigates retinal Müller cell gliosis. Exp Eye Res 2023 May;230:109461
Date
04/07/2023Pubmed ID
37023936Pubmed Central ID
PMC10157651DOI
10.1016/j.exer.2023.109461Scopus ID
2-s2.0-85151717505 (requires institutional sign-in at Scopus site) 2 CitationsAbstract
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-1β 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.
Author List
Mahaling B, Sinha NR, Sokupa S, Addi UR, Mohan RR, Chaurasia SSAuthors
Utkarsh Reddy Addi PhD Postdoctoral Researcher 1 in the Ophthalmology and Visual Sciences department at Medical College of WisconsinShyam S. Chaurasia PhD Associate Professor in the Ophthalmology and Visual Sciences department at Medical College of Wisconsin
MESH terms used to index this publication - Major topics in bold
AntioxidantsCaspases
Ependymoglial Cells
Gliosis
Humans
Inflammasomes
Mustard Gas
NLR Family, Pyrin Domain-Containing 3 Protein
