Oxidative stress induces ferroptotic cell death in retinal pigment epithelial cells

Abstract

The dysfunction and cell death of retinal pigment epithelial (RPE) cells are hallmarks of late-stage dry (atrophic) age-related macular degeneration (AMD), for which no effective therapy has yet been developed. Previous studies have indicated that iron accumulation is a source of excess free radical production in RPE, and age-dependent iron accumulation in RPE is accelerated in patients with dry AMD. Although the pathogenic role of oxidative stress in RPE in the development of dry AMD is widely accepted, the mechanisms of oxidative stress-induced RPE cell death remain elusive. Here, we show that ferroptotic cell death, a mode of regulated necrosis mediated by iron and lipid peroxidation, is implicated in oxidative stress-induced RPE cell death in vitro. In ARPE-19 cells we observed that the ferroptosis inhibitors ferrostatin-1 and deferoxamine (DFO) rescued tert-butyl hydroperoxide (tBH)-induced RPE cell death more effectively than inhibitors of apoptosis or necroptosis. tBH-induced RPE cell death was accompanied by the three characteristics of ferroptotic cell death: lipid peroxidation, glutathione depletion, and ferrous iron accumulation, which were all significantly attenuated by ferrostatin-1 and DFO. Exogenous iron overload enhanced tBH-induced RPE cell death, but this effect was also attenuated by ferrostatin-1 and DFO. Furthermore, mRNA levels of numerous genes known to regulate iron metabolism were observed to be influenced by oxidative stress. Taken together, our observations suggest that multiple modes of cell death are involved in oxidative stress-induced RPE cell death, with ferroptosis playing a particularly important role.

Myo-inositol oxygenase expression profile modulates pathogenic ferroptosis in the renal proximal tubule

“…Cells were maintained in DMEM, consisting of 10% FBS, 100 U/mL penicillin, and 100 U/mL streptomycin. They were maintained in a humidified environment with An association between ferroptosis and redox perturbations has been described previously (17,32); it is conceivable that ferroptosis may be modulated by MIOX overexpression in cisplatininduced tubular injury, since oxygen radicals are generated in the MIOX-initiated glucuronate/xylulose pathway (19). MIOX, a proximal tubular-specific enzyme, exacerbates kidney redox injury in multiple pathological states (33).…”

Crocetin Prevents RPE Cells from Oxidative Stress through Protection of Cellular Metabolic Function and Activation of ERK1/2

“…The ARPE19 cell line recapitulates structural, morphological and functional features of RPE cells [62] and was used to design an in vitro model of oxidative stress. As ARPE19 cells with longer culture periods (>1 week) have been reported to be less vulnerable to oxidative stress [63], all experiments were performed two weeks after seeding in 96-well plates with the aim to establish a robust oxidative stress model leading to significant cell damage and cell death [64,65].…”

Novel Programmed Cell Death as Therapeutic Targets in Age-Related Macular Degeneration?

“…Studies showed that a low dose of sodium iodate significantly decreased phagocytotic activity, cellular acidity, and autophagy, leading to RPE cell degeneration [ 54 , 55 ], while a high dosage of sodium iodate increased the expression of pentraxin 3, thereby accelerating RPE cell death [ 56 ]. Another in vitro model was the application of tert -butyl hydroperoxide on human fetal RPE and APRE-19 cells [ 57 ]. Moreover, a hydrogen peroxide-induced AMD cellular model has also been used to test the therapeutic efficacy of piceatannol [ 58 ], scutellarin [ 59 ], and berberine [ 60 ].…”

“…Programmed cell death (PCD) plays an important role in response to stress and the regulation of homeostasis and diseases. Apart from the classical apoptosis, recent basic science studies also discovered novel PCD such as pyroptosis [ 53 ], necroptosis [ 88 ] and ferroptosis [ 57 ], which may contribute to the RPE cell death in AMD ( Figure 2 ). A comparison of the three novel programmed cell deaths has been listed in Table 1 .…”