HO-1-mediated ferroptosis as a target for protection against retinal pigment epithelium degeneration.

Oxidative stress-mediated retinal pigment epithelium (RPE) degeneration plays a vital role in retinal degeneration with irreversible visual impairment, most notably in age-related macular degeneration (AMD), but a key pathogenic factor and the targeted medical control remain controversial and unclear. In this work, by sophisticated high-throughput sequencing and biochemistry investigations, the major pathologic processes during RPE degeneration in the sodium iodate-induced oxidative stress model has been identified to be heme oxygenase-1 (HO-1)-regulated ferroptosis, which is controlled by the Nrf2-SLC7A11-HO-1 hierarchy, through which ferrous ion accumulation and lethal oxidative stress cause RPE death and subsequently photoreceptor degeneration. By direct knockdown of HO-1 or using HO-1 inhibitor ZnPP, the specific inhibition of HO-1 overexpression has been determined to significantly block RPE ferroptosis. In mice, treatment with ZnPP effectively rescued RPE degeneration and achieved superior therapeutic effects: substantial recovery of the retinal structure and visual function. These findings highlight that targeting HO-1-mediated RPE ferroptosis could serve as an effectively retinal-protective strategy for retinal degenerative diseases prevention, including AMD.