Therapeutic Potential of AAV2-shmTOR Gene Therapy in Reducing Retinal Inflammation and Preserving Endothelial Integrity in Age-Related Macular Degeneration

Abstract Age-related macular degeneration (AMD) is a prevalent retinal disorder that leads to central vision loss, mainly due to chronic inflammation. Tumor necrosis factor-alpha (TNF-α) is a critical mediator of inflammatory responses within the retinal environment. This study has investigated TNF-α's influence on inflammatory cytokine production and endothelial barrier integrity in human microglial (HMC3) and endothelial (HUVEC) cells. We found that TNF-α significantly elevated the expression and secretion of interleukin-6 (IL-6) and interleukin-1β (IL-1β) in HMC3 cells and disrupted endothelial tight junctions in HUVECs, as evidenced by weakened ZO-1 staining and compromised barrier function. To mitigate these effects and further investigate the in vitro mechanism of actions in CRG-01’s in vivo therapeutic efficacy of anti-inflammation, we employed AAV2-shmTOR, CRG-01, as the candidate for therapeutic vector targeting the mammalian target of the rapamycin (mTOR) pathway. TNF-α-induced IL-6, IL-1β, and NF-κB signaling in HMC3 cells were significantly reduced by AAV2-shmTOR treatment, which may present a promising avenue for the fight against AMD. It also effectively preserved endothelial tight junction integrity in TNF-α-treated HUVECs, providing reassurance about its effectiveness. Furthermore, the supernatant medium collected from AAV2-shmTOR-treated HMC3 cells decreased oxidative stress, protein oxidation, and cytotoxicity in ARPE retinal pigment epithelial cells. These results strongly suggested that CRG-01, the candidate therapeutic vector of AAV2-shmTOR, may have a therapeutic potential to treat AMD-related retinal inflammation.