Abstract
Purpose :
Clinical and experimental evidence implicate oxidative stress in the pathogenesis of multiple vision threatening diseases such as age-related macular degeneration (AMD), diabetic retinopathy (DR), and glaucoma. Oxidative stress damages biological macromolecules such as proteins, lipids, and DNA. The pathological consequences of oxidative damage to lipids and proteins in the retina have been well studied. However, whether oxidative damage to DNA – which is elevated in AMD, DR, and glaucoma eye specimens, as well as in experimental animal models – contributes to retinal pathology remains a major gap in the knowledge. The goal of this study is to examine the hypothesis cGAS which is activated by damages self-DNA, plays crucial roles in mediating oxidative retinal damage.
Methods :
Human primary RPE and THP1 cells were exposed to oxidative stress by incubating with sodium iodate and cigarette smoke extract. cGAS pathway was blocking by either lentivirus delivered shRNA or CRISPR/Cas9. Activation of cGAS pathway was assessed by examining signaling activity downstream of cGAS by immunoblotting for phospho-STAT2 (pSTAT2), phosphor-ATM (pATM) and phospho-CHK2 (pCHK2).
Results :
Exposure to oxidative stress via incubation with sodium iodate and cigarette smoke extract activated type I interferons and DNA damage signaling as demonstrated by induction of pSTAT2, pATM and pCHK2. These signaling activities were dampened in cGAS knockdown and knockout cells.
Conclusions :
Our results suggest that cGAS pathway is activated by oxidative stress providing rationale for detailed analysis of role of cGAS in oxidative retinal damage.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.