Dual-restricted AAV gene delivery via suprachoroidal administration mediates precision RPE SOCS3 restoration for dry age-related macular degeneration.

Abstract

Dry age-related macular degeneration (dAMD) is a leading cause of irreversible vision loss, driven by chronic oxidative stress and inflammation in the retinal pigment epithelium (RPE). Disruption of key negative regulators of the JAK-STAT pathway, particularly SOCS3, contributes to this oxidative-inflammatory cascade. To address this, we developed a dual-restricted ocular gene delivery platform that combines suprachoroidal administration with an RPE-specific Best1 promoter, enabling localized, durable, and cell-restricted SOCS3 expression. Comparative analysis showed that intravitreal injection poorly transduced the RPE, whereas suprachoroidal delivery improved AAV access to the RPE/outer retinal region, and the Best1 promoter further restricted expression to RPE cells, reducing neural retinal off-target expression. In vitro, SOCS3 restoration suppressed STAT3 activation, inflammatory cytokine release, reactive oxygen species accumulation, mitochondrial disruption, and barrier impairment. In vivo, the dual-restricted system achieved long-term, ocular-localized expression for at least six months, reducing microglial/macrophage activation, inflammation, oxidative stress, and apoptosis, thereby preserving outer retinal architecture. Ocular and systemic safety assessments detected no overt toxicity under the tested conditions. Together, these findings support suprachoroidal AAV-Best1-SOCS3 delivery as a dual-restricted platform for localized modulation of oxidative-inflammatory retinal degeneration and warrant further preclinical evaluation.