Session
2026 Session 4
Location
Orem, UT
Start Date
5-4-2026 11:00 AM
Description
Spaceflight is associated with retinal structural changes and oxidative stress that may contribute to vision-related complications in astronauts. The retinal pigment epithelium (RPE) is a pigmented monolayer essential for retinal homeostasis and barrier integrity. It is particularly vulnerable to oxidative injury. Although melanin provides intrinsic antioxidant protection, its role in regulating epithelial integrity and stress susceptibility remains unclear. Here, a primary porcine RPE in vitro model was used to modulate pigmentation via initial seeding density (100%–12.5%). Monolayer integrity was assessed through tight junction organization (ZO-1), and oxidative stress responses were evaluated following ultraviolet A (UVA) exposure. Reduced seeding density led to decreased melanin content and disrupted ZO-1 organization under baseline conditions. UVA exposure further exacerbated ZO-1 disruption, particularly in lower pigmentation groups. No DNA double-strand breaks were observed under baseline conditions, while UV exposure induced a pigmentation-dependent increase in double stranded DNA breaks. These findings suggest that reduced pigmentation compromises RPE barrier integrity and increases susceptibility to oxidative DNA damage, providing insight into how melanin loss may contribute to retinal vulnerability under spaceflight-relevant oxidative stress.
Modeling the Effects of Retinal Pigmentation Loss and Oxidative Stress During Spaceflight
Orem, UT
Spaceflight is associated with retinal structural changes and oxidative stress that may contribute to vision-related complications in astronauts. The retinal pigment epithelium (RPE) is a pigmented monolayer essential for retinal homeostasis and barrier integrity. It is particularly vulnerable to oxidative injury. Although melanin provides intrinsic antioxidant protection, its role in regulating epithelial integrity and stress susceptibility remains unclear. Here, a primary porcine RPE in vitro model was used to modulate pigmentation via initial seeding density (100%–12.5%). Monolayer integrity was assessed through tight junction organization (ZO-1), and oxidative stress responses were evaluated following ultraviolet A (UVA) exposure. Reduced seeding density led to decreased melanin content and disrupted ZO-1 organization under baseline conditions. UVA exposure further exacerbated ZO-1 disruption, particularly in lower pigmentation groups. No DNA double-strand breaks were observed under baseline conditions, while UV exposure induced a pigmentation-dependent increase in double stranded DNA breaks. These findings suggest that reduced pigmentation compromises RPE barrier integrity and increases susceptibility to oxidative DNA damage, providing insight into how melanin loss may contribute to retinal vulnerability under spaceflight-relevant oxidative stress.