Chronic noise exposure induces Alzheimer's disease-like neuropathology and cognitive impairment via ferroptosis in rat hippocampus.

Background: Chronic noise exposure poses a remarkable public health concern, drawing attention to its impacts on the brain. Ferroptosis is involved in several brain-related diseases. However, the role of ferroptosis in the effects of chronic noise on the brain remains elusive. This study aimed to investigate the effects of chronic noise exposure on the brain and elucidate the underlying mechanisms.

Methods: A chronic noise-induced cognitive impairment model in rats was constructed and validated. The pathological state and ferroptosis level of the rat hippocampus were determined using Western blotting and immunohistochemistry. Bioinformatics was employed to investigate the interrelationship between chronic noise exposure and genes. Genetic relationships were analyzed using Mendelian randomization (MR) analysis. Cytoscape was employed for the prediction of upstream molecular and drug targets.

Results: In vivo experiments revealed that chronic noise exposure could induce Alzheimer's disease (AD)-like neuropathological changes in rat hippocampus and cognitive impairment. Moreover, protein markers indicative of ferroptosis and levels of lipid peroxidation were quantified to elucidate underlying mechanisms. Thereafter, oxidative stress- and ferroptosis-related differentially expressed genes (DEGs) underwent functional enrichment and PPI network analyses. Additionally, 8 genes with diagnostic significance were identified. In MR analysis, retinoic acid receptor responder 2 (Rarres2) gene exhibited a negative genetic relationship with AD.

Conclusions: Chronic noise exposure could induce AD-like neuropathological changes and cognitive impairment via ferroptosis. The results of MR analysis indicated that Rarres2 gene may act as a protective factor in AD. This gene may be upstream of ferroptosis and serve as a target for the prevention and treatment of chronic noise-induced cognitive impairment.