δ-Opioid Receptor Activation Inhibits Ferroptosis by Activating the Nrf2 Pathway in MPTP-Induced Parkinson Disease Models

Figure 6

DOR activation inhibits ferroptosis in the MPTP-induced mouse model of PD. (a) MDA and 4-HNE levels in the substantia nigra of mice after different treatments, as detected using MDA and 4-HNE assays kits. (b) Representative western blots of Nrf2, GPX4, and SLC7a11, and quantitative analysis of the protein levels of Nrf2, GPX4, and SLC7a11. (c) Mitochondrial substructure was observed using transmission electron microscopy in mice subjected to different treatments (scale bar = 500 nm). ↑, mitochondrial membrane rupture and loss of crista. Data are presented as the mean ± S.E. of three independent experiments. ; ns, . DOR, δ-opioid receptor; MPTP, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine; PD, Parkinson disease; MDA, malondialdehyde; 4-HNE, 4-hydroxynonenal; GPX4, glutathione peroxidase 4; DADLE, [D-Ala², D-Leu⁵]-enkephalin; ns, not significant; C, control; M, MPTP; F, ferrostatin-1; D, DADLE; N, naltrindole.

(a)

(b)

(c)