IL-4 protects against chemically-induced retinal degeneration in AMD mouse model via Nrf2 activation

To explore whether IL-4 could exert a novel protective role for RPE damage and attenuate the pathogenesis of dry age-related macular degeneration (AMD), we established a retinal degeneration model of dry AMD by intravenous injection of NaIO3, and explored the treatment effects of intravitreal IL-4 injection. We found exogenous IL-4 protected against retinal degeneration characterized by well-preserved structures and improved retinal function. The RNA-seq analysis revealed that IL-4 treatment suppressed the essential oxidative and pro-inflammatory pathways in the degenerative retina. IL-4 induced the expression of IL-4Ra and Nrf2 for anti-oxidative defense in vivo and in vitro. Our data provides evidences that IL-4 can be a useful neuroprotective agent against retinal degeneration due to its antioxidant and anti-inflammatory property through Nrf2 activation. The IL-4/IL-4Ra-Nrf2 axis maybe the potential targets for the development of novel therapies for dry AMD. Overall design: Examination of bulk RNA in RPE-sclera complex derived from PBS, NaIO3 and NaIO3+IL-4 treated mice.