Influence of β-catenin signaling on neurogenesis in neuropsychiatric disorders: Anxiety and depression

Milnacipran and Vanillin Alleviate Fibromyalgia-Associated Depression in Reserpine-Induced Rat Model: Role of Wnt/β-Catenin Signaling

Fibromyalgia (FM) patients are highly susceptible to depression. Wnt/β-catenin signaling has shown a crucial role against depression in several studies. The FDA-approved FM drug, milnacipran (Miln), has shown antinociceptive potential against FM. Yet, no study has investigated its antidepressant potential in FM. Vanillin (Van), a well-known phytochemical often employed as flavoring agent, has been previously reported for its antidepressant and antinociceptive effects in several animal models, but has not been tested so far in FM. This study explored the antidepressant effect of Van and Miln in FM through investigating Wnt/β-catenin signaling. FM was induced in female Wistar rats by injecting reserpine (1 mg/kg/day s.c) for 3 days. Thereafter, animals received either Miln (30 mg/kg/day p.o) or Van (100 mg/kg/day p.o) for the subsequent 14 days. Results showed that both drugs demonstrated antidepressant effect in forced swimming test besides analgesic, and antiallodynic influences observed in Randall-Selitto, hot plate, cold allodynia, Von-Frey, and tail immersion tests. Biochemically, Miln and Van significantly enhanced serotonergic transmission in the hippocampus and upregulated the protein expression of the Wnt/GSK-3β/β-catenin signaling axis, including the downstream proteins, T cell factor, and dicer. This is followed by subsequent upregulation of the resilience micro ribonucleic acids (miRNAs) 124 and 135. Histopathological examinations corroborated the biochemical and molecular findings. Interestingly, these effects of Miln and Van were overturned via administration of the β-catenin inhibitor, XAV939 (0.1 mg/kg, i.p., daily). In conclusion, this study outlined the antidepressant aptitude of Miln and Van through activating Wnt/β-catenin signaling in the hippocampus in reserpine-induced FM.

Eupalinolide B alleviates corticosterone-induced PC12 cell injury and improves depression-like behaviors in CUMS rats by regulating the GSK-3β/β-catenin pathway

Eupalinolide B (EB), a primary bioactive compound isolated from Eupatorium lindleyanum DC., has exhibited various pharmacological properties, such as antitumor, anti-inflammatory, and notably, neuroprotective effects in neurodegenerative diseases. However, the in-depth studies on the antidepressant potential of EB and its underlying mechanisms are still lacking. Herein, we investigated the therapeutic effects of EB on corticosterone (CORT)-induced neurotoxicity in PC12 cells and its antidepressant-like effects in rats subjected to chronic unpredictable mild stress (CUMS). In particular, we focused on the molecular mechanisms related to modulating the GSK-3β/β-catenin pathway. Our findings revealed that EB promoted cell proliferation while decreasing apoptosis and oxidative stress in CORT-induced PC12 cells. In vivo, EB alleviated the depressive-like behaviors in CUMS rats, as assayed by the sucrose preference test, open field test, and forced swim test. Additionally, EB attenuated the hippocampal pathological damage and increased Ki67- and doublecortin-positive cell numbers in hippocampal dentate gyrus, thus restoring hippocampal neurogenesis in CUMS rats. The binding of EB to GSK-3β was confirmed using molecular docking and cellular thermal shift assays. Overexpression of GSK-3β diminished the therapeutic effects of EB on CORT-induced PC12 cells, further indicating that GSK-3β is the target of EB. Mechanistically, EB hindered GSK-3β activity and thus activated β-catenin signaling in both CORT-induced PC12 cells and CUMS rat hippocampus, as demonstrated by increased p-GSK-3β (Ser9), reduced p-β-catenin, and elevated β-catenin expression. Collectively, this study offers new insights into the antidepressant mechanisms of EB, highlighting its potential as a candidate for depression treatment.

Vilazodone Alleviates Neurogenesis-Induced Anxiety in the Chronic Unpredictable Mild Stress Female Rat Model: Role of Wnt/β-Catenin Signaling

Defective β-catenin signaling is accompanied with compensatory neurogenesis process that may pave to anxiety. β-Catenin has a distinct role in alleviating anxiety in adolescence; however, it undergoes degradation by the degradation complex Axin and APC. Vilazodone (VZ) is a fast, effective antidepressant with SSRI activity and 5-HT1A partial agonism that amends somatic and/or psychic symptoms of anxiety. Yet, there is no data about anxiolytic effect of VZ on anxiety-related neurogenesis provoked by stress-reduced β-catenin signaling. Furthermore, females have specific susceptibility toward psychopathology. The aim of the present study is to uncover the molecular mechanism of VZ relative to Wnt/β-catenin signaling in female rats. Stress-induced anxiety was conducted by subjecting the rats to different stressful stimuli for 21 days. On the 15th day, stressed rats were treated with VZ(10 mg/kg, p.o.) alone or concomitant with the Wnt inhibitor: XAV939 (0.1 mg/kg, i.p.). Anxious rats showed low β-catenin level turned over by Axin-1 with unanticipated reduction of APC pursued with elevated protein levels of neurogenesis-stimulating proteins: c-Myc and pThr183-Erk likewise gene expressions of miR-17-5p and miR-18. Two weeks of VZ treatment showed anxiolytic effect figured by alleviation of hippocampal histological examination. VZ protected β-catenin signal via reduction in Axin-1 and elevation of APC conjugated with modulation of β-catenin downstream targets. The cytoplasmic β-catenin turnover by Axin-1 was restored by XAV939. Herein, VZ showed anti-anxiety effect, which may be in part through regaining the balance of the reduced β-catenin and its subsequent exaggerated response of p-Erk, c-Myc, Dicer-1, miR-17-5p, and miR-18.