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Depression is a major mental illness, and its underlying mechanisms remain unclear. Emerging evidence suggests that astrocytes, which play a crucial role in brain function, may be involved in the pathophysiology of depression. We previously showed that downregulation of astrocytic connexin43 (Cx43) enhances the antidepressant effect of amitriptyline. However, the precise molecular mechanisms underlying this phenomenon remain unknown. In the present study, we investigated the signaling pathways involved in the antidepressant action of amitriptyline using an in vitro model involving Cx43-knockdown astrocytes. We found that amitriptyline potentiated the expression of brain-derived neurotrophic factor (BDNF), a key neurotrophic factor, in Cx43-knockdown astrocytes. This potentiation was mediated by the activation of Gq protein-coupled lysophosphatidic acid (LPA) receptors, a pathway that was sensitized by Cx43 downregulation. We further demonstrated that this signaling cascade involved the activation of Protein Kinase C (PKC) δ and transcription factor NF-κB, but not the conventional BDNF transcription factor CREB. We propose that Cx43 downregulation enhances the antidepressant effect of amitriptyline by specifically engaging the Gq-PKCδ-NF-κB pathway. These findings suggest that Cx43 downregulation in astrocytes, which has been considered a pathological feature of depression, may paradoxically contribute to the therapeutic efficacy of antidepressants by sensitizing a specific signaling pathway. Our study provides new insights into the molecular mechanism of antidepressant action and highlights the potential role of astrocytic Cx43 in modulating therapeutic responses. Show less

Dingzhi Pills, a traditional Chinese medicine(TCM) formula, is frequently employed in clinical settings for treating depression, yet its treatment mechanism remains poorly understood. This study investigates the efficacy of Dingzhi Pills in mitigating depression and delineates the associated metabolic pathways. The chemical constituents of Dingzhi Pills were identified by ultra-fast liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry(UFLC-Q-TOF-MS/MS). The optimal dose for treating depression in mice was determined via a mouse model of behavioral despair. Furthermore, a lipopolysaccharide(LPS)-induced depression model was established in mice and used to validate the results of pharmacological and metabolomic analyses. The results indicated that Dingzhi Pills ameliorated depression-like behaviors in mice, attenuated the LPS-induced rises in levels of inflammatory cytokines, and suppressed the activities of tumor necrosis factor-α(TNF-α) and interleukin-6(IL-6), thus reducing the glutamate level. Additionally, Dingzhi Pills enhanced the expression of brain-derived neurotrophic factor(BDNF), tyrosine receptor kinase B(TrkB), mammalian target of rapamycin(mTOR), and glutamate A1(GluA1). Metabolomic profiling of the brain tissue revealed 46 unique metabolites, which served as candidate biomarkers for the antidepressant effect of Dingzhi Pills. Collectively, the data demonstrate that Dingzhi Pills alleviates depression by modulating inflammatory responses, the AMPA/BDNF/TrkB/mTOR signaling pathway, the biosynthesis of valine, leucine, and isoleucine, and the metabolism of 2-oxycarboxylic acid, providing scientific evidence for the antidepressant effect of Dingzhi Pills. Show less

This research aimed to explore the serum levels of calcium/calmodulin-dependent protein kinase II (CaMKII) in hyperventilation syndrome (HVS) patients and its correlation with psychological disorders. This prospective observational study enrolled 168 HVS patients who came to our hospital from February 2021 to January 2023. The serum CaMKII, 5-hydroxytryptamine (5-HT), and brain-derived neurotrophic factor (BDNF) levels were measured by enzyme-linked immunosorbent assay method. Hamilton depression rating scale was used to assess the depression status of all study subjects. Hamilton anxiety rating scale, the self-rating anxiety scale, and the self-rating depression scale were used to further evaluate the psychological status of all patients. The self-rating depression scale, Hamilton anxiety rating scale, and self-rating anxiety scale scores in the depression group were significantly elevated compared to the non-depression group (P < .05). The serum CaMKII, 5-HT, and BDNF levels were significantly declined in the depression group compared to the non-depression group. Pearson analysis showed a positive correlation among CaMKII levels, 5-HT levels, and BDNF levels. Serum levels of CaMKII were associated with the psychological status of HVS patients (depression and anxiety). CaMKII could be used to predict depression in HVS patients. CaMKII was a risk factor for depression in HVS patients. This study showed that the serum CaMKII levels decreased in HVS patients with depression. The serum CaMKII level was correlated with 5-HT, BDNF and could be used to predict depression in HVS patients. Show less