CB2R-mediated GPX4 stabilization: a new avenue for treating cognitive impairment in elderly migraine patients.

Migraine is frequently associated with cognitive impairment, a pathology linked to microglial dysfunction and neuroinflammation. Ferroptosis, a form of iron-dependent lipid peroxidation, driven by the depletion of glutathione peroxidase 4 (GPX4), is increasingly implicated in neurodegenerative processes. This study investigates the protective role of cannabinoid receptor type 2 (CB2R) activation against migraine-associated cognitive deficits by modulating microglial ferroptosis. We demonstrate that CB2R activation, via its agonist JWH133, significantly ameliorates cognitive impairment and synaptic damage in a nitroglycerin-induced migraine model. Mechanistically, JWH133 suppresses microglial ferroptosis by stabilizing GPX4. Our findings reveal that in inflammatory conditions, the E3 ubiquitin ligase Tripartite Motif Containing 33 (TRIM33) mediates the K63-linked polyubiquitination of GPX4, marking it for breakdown via autophagy, a cellular process that degrades unwanted proteins through lysosomes. CB2R activation inhibits TRIM33-GPX4 interaction and subsequent K63-linked ubiquitination, thereby preventing GPX4 degradation and restoring its anti-lipid peroxidation function. This stabilization of GPX4 mitigates mitochondrial dysfunction and lipid peroxidation, as evidenced by lipidomics and mitochondrial assays. Collectively, our study uncovers a novel CB2R-TRIM33-K63 ubiquitination-autophagy axis that critically regulates GPX4 stability and microglial ferroptosis. Targeting this pathway offers a promising therapeutic strategy for mitigating migraine-associated cognitive impairment.