TCF4 trinucleotide repeat expansions and UV irradiation increase susceptibility to ferroptosis in Fuchs endothelial corneal dystrophy
Sanjib Saha,
Jessica M. Skeie,
Gregory A. Schmidt,
Tim Eggleston,
Hanna Shevalye,
Christopher S. Sales,
Pornpoj Phruttiwanichakun,
Apurva Dusane,
Matthew G. Field,
Tommy A. Rinkoski,
Michael P. Fautsch,
Keith H. Baratz,
Madhuparna Roy,
Albert S. Jun,
Chandler Pendleton,
Aliasger K. Salem,
Mark A. Greiner
Affiliations
Sanjib Saha
Department of Pharmaceutical Sciences and Experimental Therapeutics, College of Pharmacy, University of Iowa, Iowa City, IA, 52242, USA
Jessica M. Skeie
Department of Ophthalmology & Visual Sciences, Carver College of Medicine, University of Iowa, Iowa City, IA, 52242, USA; Iowa Lions Eye Bank, Coralville, IA, 52241, USA
Gregory A. Schmidt
Iowa Lions Eye Bank, Coralville, IA, 52241, USA
Tim Eggleston
Iowa Lions Eye Bank, Coralville, IA, 52241, USA
Hanna Shevalye
Iowa Lions Eye Bank, Coralville, IA, 52241, USA
Christopher S. Sales
Department of Ophthalmology & Visual Sciences, Carver College of Medicine, University of Iowa, Iowa City, IA, 52242, USA; Iowa Lions Eye Bank, Coralville, IA, 52241, USA
Pornpoj Phruttiwanichakun
Department of Pharmaceutical Sciences and Experimental Therapeutics, College of Pharmacy, University of Iowa, Iowa City, IA, 52242, USA
Apurva Dusane
Department of Pharmaceutical Sciences and Experimental Therapeutics, College of Pharmacy, University of Iowa, Iowa City, IA, 52242, USA
Matthew G. Field
Department of Ophthalmology & Visual Sciences, Carver College of Medicine, University of Iowa, Iowa City, IA, 52242, USA
Tommy A. Rinkoski
Department of Ophthalmology, 200 1st St SW, Mayo Clinic, Rochester, MN, 55905, USA
Michael P. Fautsch
Department of Ophthalmology, 200 1st St SW, Mayo Clinic, Rochester, MN, 55905, USA
Keith H. Baratz
Department of Ophthalmology, 200 1st St SW, Mayo Clinic, Rochester, MN, 55905, USA
Madhuparna Roy
Wilmer Eye Institute, Johns Hopkins Medical Institutions, Baltimore, MD, 21287, USA
Albert S. Jun
Wilmer Eye Institute, Johns Hopkins Medical Institutions, Baltimore, MD, 21287, USA
Chandler Pendleton
The University of Iowa College of Dentistry and Dental Clinics, Iowa City, IA, USA
Aliasger K. Salem
Department of Pharmaceutical Sciences and Experimental Therapeutics, College of Pharmacy, University of Iowa, Iowa City, IA, 52242, USA; Corresponding author.
Mark A. Greiner
Department of Pharmaceutical Sciences and Experimental Therapeutics, College of Pharmacy, University of Iowa, Iowa City, IA, 52242, USA; Department of Ophthalmology & Visual Sciences, Carver College of Medicine, University of Iowa, Iowa City, IA, 52242, USA; Iowa Lions Eye Bank, Coralville, IA, 52241, USA; Corresponding author.
Fuchs endothelial corneal dystrophy (FECD), the leading indication for corneal transplantation in the U.S., causes loss of corneal endothelial cells (CECs) and corneal edema leading to vision loss. FECD pathogenesis is linked to impaired response to oxidative stress and environmental ultraviolet A (UVA) exposure. Although UVA is known to cause nonapoptotic oxidative cell death resulting from iron-mediated lipid peroxidation, ferroptosis has not been characterized in FECD. We investigated the roles of genetic background and UVA exposure in causing CEC degeneration in FECD. Using ungenotyped FECD patient surgical samples, we found increased levels of cytosolic ferrous iron (Fe2+) and lipid peroxidation in end-stage diseased tissues compared with healthy controls. Using primary and immortalized cell cultures modeling the TCF4 intronic trinucleotide repeat expansion genotype, we found altered gene and protein expression involved in ferroptosis compared to controls including elevated levels of Fe2+, basal lipid peroxidation, and the ferroptosis-specific marker transferrin receptor 1. Increased cytosolic Fe2+ levels were detected after physiologically relevant doses of UVA exposure, indicating a role for ferroptosis in FECD disease progression. Cultured cells were more prone to ferroptosis induced by RSL3 and UVA than controls, indicating ferroptosis susceptibility is increased by both FECD genetic background and UVA. Finally, cell death was preventable after RSL3 induced ferroptosis using solubilized ubiquinol, indicating a role for anti-ferroptosis therapies in FECD. This investigation demonstrates that genetic background and UVA exposure contribute to iron-mediated lipid peroxidation and cell death in FECD, and provides the basis for future investigations of ferroptosis-mediated disease progression in FECD.
