Major depressive disorder (MDD) is common, and successful treatment remains challenging. Resveratrol, a naturally occurring polyphenol, has been shown to alleviate depression-like behaviors, but the underlying mechanisms remain unclear. We previously developed a new model of depression by inducing hippocampal ferroptosis in rats, suggesting that ferroptosis may be involved in the development of MDD. Here, we further explored the antidepressant-like effect of resveratrol and its association with ferroptosis. Male rats were exposed to chronic unpredictable mild stress (CUMS), with or without resveratrol, followed by comprehensive behavioral testing. In PC12 cells in vitro, LY294002 (an AKT inhibitor) and ML385 (an NRF2 inhibitor) were used to elucidate the involvement of AKT/NRF2 signaling in resveratrol-mediated ferroptosis. mRNA and protein levels of AKT/NRF2 pathway and ferroptosis-related targets were measured. Ferroptosis was quantified by measuring malondialdehyde (MDA), glutathione (GSH), and Fe²⁺ content and superoxide dismutase (SOD) activity. Resveratrol ameliorated depression-like behaviors in rats, simultaneously restoring AKT/NRF2 pathway and ferroptosis-related targets in the hippocampus downregulated by CUMS. Elevated markers of oxidative stress in plasma were attenuated by resveratrol. Furthermore, erastin induced ferroptosis and inhibited AKT/NRF2 signaling in PC12 cells, which was counteracted by resveratrol. Additionally, the impact of resveratrol on erastin-induced ferroptosis was reversed by LY294002 and ML385. This study demonstrates that resveratrol ameliorates depression-like behaviors by inhibiting ferroptosis via the AKT/NRF2 pathway.

Resveratrol, a plant-derived polyphenol, exhibits significant antidepressant effects and notably enhances neuroplasticity in neurological diseases. However, whether the antidepressant function of resveratrol is related to neuroplasticity remains uncertain, and the underlying mechanisms is poorly understood. This study aims to investigate the role and mechanism of resveratrol in neuroplasticity in depression. Here, we adopted the chronic unpredictable mild stress (CUMS) model and resveratrol intervention by oral gavage. Thereafter, behavioral tests confirmed resveratrol’s antidepressant effect, and Nissl staining, Golgi staining, and Western blotting (WB) were employed to assess the neuronal plasticity. Moreover, proteomic analysis and WB were used to screen and identify the key proteins. To investigate the downstream target of ELAV-like RNA-binding protein 4 (ELAVL4) (one of candidate genes), the RNA Interactome Database and the National Center for Biotechnology Information databases were utilized to predict the targets of ELAVL4. Finally, Quantitative PCR, WB, and Immunofluorescence were used to verify the prediction. Our results indicate that resveratrol alleviates CUMS-induced depressive-like behaviors accompanied by the restoration of impaired hippocampal neuroplasticity. Then, proteomic analysis shows that 351 differentially expressed proteins (DEPs) decrease after CUMS, while 24 DEPs increase remarkably with the resveratrol treatment. Among which, ELAVL4 is downregulated by CUMS, simultaneously increasing after resveratrol intervention, which acts as a protective protein in this process. Finally, brain-derived neurotrophic factor (Bdnf) mRNA is predicted to be the potential target of ELAVL4 and validated by molecular technologies. In conclusion, our findings demonstrate that resveratrol’s antidepressant efficacy is closely associated with ELAVL4, an RNA-binding protein, a mediated neuroplasticity pathway, potentially intersecting with the Bdnf mRNA. Overall, this research sheds light on the role of the ELAVL4-Bdnf mRNA pathway through neuroplasticity in resveratrol’s antidepressant action, which provides an mRNA regulation perspective for the development of novel antidepressants and understanding depression pathology.

Endoplasmic reticulum (ER) stress participates in the occurrence and development of depression, but the underlying mechanism is not fully understood. This study aimed to investigate the behavioral performance and intracerebral molecular changes in an ER stress model of male rats. Intrahippocampal injection of tunicamycin (TM) was performed on male rats as a model of ER stress. The body weight was determined, and behavioral tests, including sucrose preference test (SPT), open field test (OFT), and forced swimming test (FST), were performed to evaluate depressive and anxiety-like phenotypes within 8 days after injection. The levels of chaperone-mediated autophagy (CMA), synaptic proteins, and neuroinflammation related factors in this model were measured via real-time quantitative PCR and Western blot analysis. Intrahippocampal injection of TM (2 or 1 μg) induced depression-like behaviors in rats, as indicated by the reduced body weight, sucrose preference in SPT, central time in OFT, and increased immobility time in FST. The mRNA and protein levels of GRP78, ATF4, CHOP, LAMP2A, IL-1β, IL-6, and TNF-α were significantly increased, while the expressions of MEF2D, PSD95, SYN, p-CREB (Ser133), and BDNF were significantly decreased in the hippocampus in the model group compared with the sham group. These results confirmed that intrahippocampal injection of TM was a valid method to induce an ER stress rat model with depression-like behaviors accompanied by decreased synaptic protein expression and neuroinflammation. The alteration in CMA-related proteins in this ER stress depression model indicated the involvement of CMA in the development of depression.

Resveratrol, a natural bitter polyphenol, exhibits significant antidepressant property. Numerous studies have linked its antidepressant effect to neuroplasticity enhancement or mitochondrial regulation. However, the interplay between these two mechanisms remains unclear. This study aims to elucidate the relationship among resveratrol's antidepressant effect, its regulatory impact on neuroplasticity and mitochondrial function, and to investigate the potential role of the type 2 bitter taste receptors (Tas2rs) in these processes. A chronic unpredictable mild stress (CUMS) model was used to induce depressive-like behaviors, while resveratrol was administered as an intervention. Following CUMS and resveratrol treatment, proteomic analysis combined with bioinformatics predicted significantly altered biological pathways in the hippocampus. The aforementioned predictions were validated using Western blotting (WB), Golgi staining, Nissl staining, and electron microscopy. Additionally, Tas2rs expression and calcium (Ca^2 +) levels in the hippocampus were quantified using quantitative PCR, WB, and calcium assay kit. Finally, immunofluorescence (IF) colocalization was used to examine the association of Tas2r123 with mitochondrial outer membrane in hippocampus. Resveratrol significantly alleviated depressive-like behaviors induced by CUMS. Proteomic analysis revealed that resveratrol's therapeutic effects are associated with neuroplasticity-related and metabolic pathways, particularly with differentially expressed proteins (DEPs) predominantly localized in the mitochondria. Gene Ontology analysis of mitochondrial DEPs further revealed substantial changes in mitochondrial organization. Furthermore, molecular biology experiments validated these proteomics findings. Additionally, resveratrol also reversed the CUMS-induced downregulation of Tas2r123 mRNA and protein expression. Moreover, IF colocalization demonstrated a strong association between Tas2r123 and mitochondria. Our findings suggest that resveratrol may exert antidepressant property by modulating neuroplasticity through the Tas2r123-mitochondrial organization pathway. This study introduces a novel perspective linking Tas2rs to resveratrol's antidepressant mechanisms, potentially pave the way for future antidepressant therapies.