Quantitative proteomic analysis of the liver reveals antidepressant potential protein targets of Sinisan in a mouse CUMS model of depression

Sinisan Alleviates Stress-Induced Intestinal Dysfunction and Depressive-like Behaviors in Mice with Irritable Bowel Syndrome by Enhancing the Intestinal Barrier and Modulating Central 5-Hydroxytryptamine

Irritable bowel syndrome (IBS) is a common chronic functional bowel disorder and is strongly associated with an increased risk of depression and anxiety. The brain-gut axis plays an important role in the pathophysiologic changes in IBS, yet effective treatments for IBS are still lacking. Sinisan, originating from the Treatise on Typhoid Fever by the medical sage Zhang Zhongjing, is a classic formula in the Eight Methods of Traditional Chinese Medicine (TCM) that focuses on dispersing the liver and regulating the spleen, relieving depression and transmitting evils, and has been widely used in the treatment of liver-depression and spleen-deficiency, diarrhea, and related liver and stomach disorders. However, the therapeutic effect of sinisan in IBS has not been clarified. The aim of this study was to investigate the effects of sinisan on stress-induced intestinal dysfunction and depressive behavior in IBS mice. We established a diarrhea-predominant irritable bowel syndrome (IBS-D) mouse model using a 4% acetic acid enema combined with restraint stress, and analyzed the results using behavioral tests, relevant test kits, hematoxylin-eosin (HE) staining, immunofluorescence (IF), Western blot (WB), and quantitative fluorescence polymerase chain reaction (qRT-PCR). The results showed that sinisan administration significantly alleviated intestinal dysfunction and depressive-like behaviors in IBS-D mice, improved mild colonic inflammation and intestinal mucosal permeability, up-regulated the expression of tight junction proteins ZO-1 and occludin. Sinisan significantly alleviated intestinal dysfunction and depressive-like behaviors in IBS-D mice by decreasing the expression of TNF-α, promoting the expression of tight junction proteins (occludin, ZO-1) expression, and inhibiting the Tlr4/Myd88 signaling pathway, thereby attenuating the inflammatory response, protecting the intestinal barrier, and alleviating symptoms in the IBS-D mouse model. Taken together, sinisan may ameliorate intestinal inflammation and the intestinal barrier by regulating 5-HT expression and the Tlr4/Myd88 pathway, thereby alleviating stress-induced intestinal dysfunction and depressive behaviors in IBS-D mice.

Modified Danzhi XiaoyaoSan inhibits neuroinflammation via regulating TRIM31/NLRP3 inflammasome in the treatment of CUMS depression

The NLRP3 inflammasome is critically involved in the development of depression. The E3 ubiquitin ligase TRIM31 negatively regulates this process by promoting the degradation of NLRP3 through the ubiquitin-proteasome pathway. Modified Danzhi Xiaoyaosan (MDZXYS) has shown good therapeutic effect in both preclinical and clinical depression treatments, yet the underlying mechanisms of its antidepressant effects are not fully understood. In the present study, we aimed to explore the antidepressant mechanisms of MDZXYS, focusing on NLRP3 activation and ubiquitin-mediated degradation. We employed rats with depression induced by chronic unpredictable mild stress (CUMS) and conducted various behavioral tests, including the sucrose preference, forced swimming, and open field tests. Neuronal damage in CUMS-treated rats was assessed using Nissl staining. We measured proinflammatory cytokine levels using ELISA kits and analyzed NLRP3/TRIM31 protein expression via Western blotting and immunofluorescence staining. Our results disclosed that MDZXYS reversed CUMS-induced depression-like behaviors in rats, reduced proinflammatory cytokine levels (IL-1β), and ameliorated neuronal damage in the prefrontal cortex. Additionally, CUMS activated the NLRP3 inflammasome in the prefrontal cortex and upregulated the protein expression of TRIM31. After MDZXYS administration, the expression of NLRP3 inflammasome-associated proteins was reduced, while the expression level of TRIM31 was further increased. Through co-localized immunofluorescence staining, we observed a significant elevation in the co-localization expression of NLRP3 and TRIM31 in the prefrontal cortex of the MDZXYS group. These findings suggest that inhibiting NLRP3 inflammasome-mediated neuroinflammation by modulating the TRIM31signaling pathway may underlie the antidepressant effects of MDZXYS, and further support targeting NLRP3 as a novel approach for the prevention and treatment of depression.

Alleviation of endothelial dysfunction of Pheretima guillemi (Michaelsen)-derived protein DPf3 in ponatinib-induced thrombotic zebrafish and mechanisms explored through ox-LDL-induced HUVECs and TMT-based proteomics

ETHNOPHARMACOLOGICAL RELEVANCE

Thrombus generation is one of the leading causes of death in human, and vascular endothelial dysfunction is a major contributor to thrombosis. Pheretima guillemi (Michaelsen), a traditional medicinal animal known as "Dilong", has been utilized to cure thrombotic disorders for many years. DPf3, a group of functional proteins extracted from P. guillemi, has been characterized and identified to possess antithrombotic bioactivity via in vitro and ex vivo experiments.

AIM OF THE STUDY

This study is aimed to investigate the vascular-protection activity and related mechanism of antithrombotic protein DPf3 purified from Pheretima guillelmi systematically.

MATERIALS AND METHODS

The antithrombotic activity and vascular endothelium protection effect of DPf3 was explored in vivo using ponatinib-induced vascular endothelial injury zebrafish thrombus model. Then, (hi) ox-LDL-induced HUVECs was applied to investigate the protection mechanism of DPf3 against the injury of vascular endothelium. In addition, TMT-based proteomics analysis was used to study the biomarkers, biological processes and signal pathways involved in the antithrombotic and vascular protective effects of DPf3 holistically.

RESULTS

DPf3 exerted robust in vivo antithrombosis and vascular endothelial protection ability. DPf3 was identified to prevent HUVECs from damage by reducing ROS production, and to reduce monocyte adhesion by decreasing the protein content of adhesion factor VCAM 1. DPf3 was also observed to weaken the migration ability of injured cells and inhibit abnormal angiogenesis. The mechanism of DPf3's antithrombotic and vascular protective activity was mainly related to the regulation of lipid metabolism, energy metabolism, complement and coagulation system, ECM receptor interaction, MAPK signal pathway, etc. CONCLUSIONS: This study demonstrates that DPf3 has strong antithrombotic and endothelial protective effects. The endothelial protective ability and related mechanisms of DPf3 provide a scientific reference for the traditional use of earthworms in the treatment of thrombosis.

Exploring the mechanism of Si-Ni-San against depression by UPLC-Q-TOF-MS/MS integrated with network pharmacology: experimental research

Background

Depression is becoming an urgent mental health problem. Si-Ni-San has been widely used to treat depression, yet its underlying pharmacological mechanism is poorly understood. Thus, we aim to explore the antidepressant mechanism of Si-Ni-San by chemical analysis and in-silico methods.

Methods

Compounds in Si-Ni-San were determined by ultra-high performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry (UPLC-Q-TOF-MS/MS). Then, bioactive compounds were obtained from Traditional Chinese Medicines for Systems Pharmacology Database and Analysis Platform and SwissADME, and the potential targets of which were acquired from SwissTargetPrediction. Depression-related targets were collected from GeneCards. The intersection between compound-related targets and depression-related targets were screened out, and the overlapped targets were further performed protein-protein interaction, biological functional and pathway enrichment analysis. Finally, networks of Si-Ni-San against depression were constructed and visualized by Cytoscape.

Results

One hundred nineteen compounds in Si-Ni-San were determined, of which 24 bioactive compounds were obtained. Then, 137 overlapped targets of Si-Ni-San against depression were collected. AKT1, PIK3R1, PIK3CA, mTOR, MAPK1 and MAPK8 were the key targets. Furthermore, PI3K-Akt signalling pathway, serotonergic synapse, MAPK signalling pathway and neurotrophin signalling pathway were involved in the antidepressant mechanism of Si-Ni-San. It showed that components like sinensetin, hesperetin, liquiritigenin, naringenin, quercetin, albiflorin and paeoniflorin were the mainly key active compounds for the antidepressant effect of Si-Ni-San.

Conclusions

This study demonstrated the key components, key targets and potential pharmacological mechanisms of Si-Ni-San against depression. These results indicate that Si-Ni-San is a promising therapeutic approach for treatment of depression, and may provide evidence for the research and development of drugs for treating depression.

Pharmacokinetic evaluation of Sinisan containing vinegar-processed products in depressive rats, a comprehensive perspective of 'individual herb, herb-pair, and herbal formula'

ETHNOPHARMACOLOGICAL RELEVANCE

As a classical formula for the treatment of depression, the clinical application of vinegar-processed products of Bupleuri Radix (Bupleurum chinense DC., BR) and Paeoniae Radix Alba (Paeonia lactiflora Pall., PRA) contained in Sinisan (SNS) is still controversial.

AIM OF THE STUDY

Three levels of 'individual herb, herb-pair, and herbal formula' were employed to investigate whether and how the processing of main drugs affected the active constituents of pharmacokinetics in SNS, as well as their impacts on the hepatic CYP450 enzyme.

MATERIALS AND METHODS

Rats were subjected to construct a chronic unpredictable mild stimulation (CUMS) model. A rapid and sensitive ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS/MS) analytical method was developed and validated for simultaneously quantitative evaluation of thirteen potential active compounds of SNS in depressive rat plasma, and successfully applied to a holistic comparison of pharmacokinetics. The differences in pharmacokinetic parameters based on three different forms of drug composition from BR and PRA before and after vinegar-processing were compared. Meanwhile, qRT-PCR and Western Blot were utilized to explore the metabolic activity of three isoforms of CYP450 enzyme scattered in the livers of depressive rats.

RESULTS

The characteristic pharmacokinetics profiles of thirteen representative constituents in CUMS rats were influenced by vinegar-processing of BR and PRA and/or the compatibility. In detail, there were significant differences in the Cmax, AUC0-24, AUC0-∞, t1/2, and MRT0-24 of most constituents among the three different forms of drug composition from BR and PRA before and after vinegar-processing, with the most obvious changes in six constituents from the adjuvant and mediating guide drugs. And also, the pharmacokinetic parameters of seven constituents from BR and PRA in SNS containing vinegar-processed products obviously changed after compatibility. Additionally, the mRNA and protein levels of CYP1A2, CYP2E1, and CYP3A1 were observed to increase significantly with the processing of BR and PRA and the combination/formulation.

CONCLUSIONS

In conclusion, SNS containing vinegar-processed products was more conducive to the absorption of most activated constituents compared to the original formula in vivo. The vinegar-processing of BR and PRA and the compatibility co-contribute to the pharmacokinetic variability of active compounds of SNS in CUMS rats, and the extent of contribution varies among drugs, which might be related to the regulation of the hepatic drug metabolizing enzymes. The finding of the investigation could help to better understand how active compounds metabolized in vivo, which might be helpful for guiding the clinical application of SNS containing vinegar-processed products.

Si-Ni-San alleviates early life stress-induced depression-like behaviors in adolescence via modulating Rac1 activity and associated spine plasticity in the nucleus accumbens

Background: Early life stress (ELS) is a major risk factor for depression in adolescents. The nucleus accumbens (NAc) is a key center of the reward system, and spine remodeling in the NAc contributes to the development of depression. The Si-Ni-San formula (SNS) is a fundamental prescription for treating depression in traditional Chinese medicine. However, little is known about the effects of SNS on behavioral abnormalities and spine plasticity in the NAc induced by ELS. Purpose: This study aimed to investigate the therapeutic effect and the modulatory mechanism of SNS on abnormal behaviors and spine plasticity in the NAc caused by ELS. Methods: We utilized a model of ELS that involved maternal separation with early weaning to explore the protective effects of SNS on adolescent depression. Depressive-like behaviors were evaluated by the sucrose preference test, the tail suspension test, and the forced swimming test; anxiety-like behaviors were monitored by the open field test and the elevated plus maze. A laser scanning confocal microscope was used to analyze dendritic spine remodeling in the NAc. The activity of Rac1 was detected by pull-down and Western blot tests. Viral-mediated gene transfer of Rac1 was used to investigate its role in ELS-induced depression-like behaviors in adolescence. Results: ELS induced depression-like behaviors but not anxiety-like behaviors in adolescent mice, accompanied by an increase in stubby spine density, a decrease in mushroom spine density, and decreased Rac1 activity in the NAc. Overexpression of constitutively active Rac1 in the NAc reversed depression-related behaviors, leading to a decrease in stubby spine density and an increase in mushroom spine density. Moreover, SNS attenuated depression-like behavior in adolescent mice and counteracted the spine abnormalities in the NAc induced by ELS. Additionally, SNS increased NAc Rac1 activity, and the inhibition of Rac1 activity weakened the antidepressant effect of SNS. Conclusion: These results suggest that SNS may exert its antidepressant effects by modulating Rac1 activity and associated spine plasticity in the NAc.

Suppressive effects of bilobalide on depression-like behaviors induced by chronic unpredictable mild stress in mice

Background: Depression is a psychiatric disorder with depressed mood and even suicide attempts as the main clinical symptoms, and its pathogenesis has not yet been fully elucidated. Brain derived neurotrophic factor (BDNF) plays an important role in the pathogenesis of depression. Purpose: The main aim of the present study was to evaluate the effectiveness and reveal the potential mechanisms of bilobalide (BB) intervention in alleviating depression-like behaviors by using chronic unpredictable mild stress (CUMS) mice via mediating the BDNF pathway. Methods: Behavioral assessments were carried out by using the sucrose preference test (SPT), tail suspension test (TST), and forced swimming test (FST). CUMS mice were randomly divided into 5 groups: CUMS + solvent, CUMS + BB low, CUMS + BB medium, CUMS + BB high and CUMS + fluoxetine. Total serum levels of tumor necrosis factor (TNF-α) and interleukin-6 (IL-6) were measured by ELISA. Expression of TNF-α, IL-6, AKT, GSK3β, β-catenin, Trk-B and BDNF in the mouse hippocampus was assessed by western blotting. Results: BB treatment reduced the levels of pro-inflammatory cytokines (IL-6 and TNF-α) and increased the protein expression of BDNF in the hippocampus region of the CUMS mice. Moreover, BB treatment enhanced the AKT/GSK3β/β-catenin signaling pathway which is downstream of the BDNF receptor Trk-B in the hippocampus of these mice. Conclusions: Overall, the experimental results indicated that BB reverses CUMS-induced depression-like behavior. BB exerts antidepressant-like effects by inhibiting neuroinflammation and enhancing the function of neurotrophic factors.

The Effects of Early-Life Stress on Liver Transcriptomics and the Protective Role of EPA in a Mouse Model of Early-Life-Stress-Induced Adolescent Depression

Early-life stress (ELS) was found to increase the risk of adolescent depression, and clinical evidence indicated that eicosapentaenoic acid (EPA) was decreased in patients with adolescent depression, but the underlying mechanisms are unclear. Here, we utilized an ELS model of maternal separation with early weaning to explore the protective role of EPA in adolescent depression. We found that that ELS induced depression-like behavior rather than anxiety-like behavior in adolescent mice. RNA-sequencing results showed that ELS changed the transcription pattern in the liver, including 863 upregulated genes and 971 downregulated genes, especially those related to the biosynthesis of unsaturated fatty acids metabolism in the liver. Moreover, ELS decreased the expression of the rate-limiting enzymes, fatty acid desaturases 1/2 (FADS1/2), involved in the biosynthesis of EPA in the liver. Additionally, ELS reduced the levels of EPA in the liver, serum, and hippocampus, and EPA administration improved depression-like behavior-induced by ELS. Our results provide transcriptomic evidence that ELS increases the risk of adolescent depression by reducing the synthesis of unsaturated fatty acids in the liver, especially EPA, and suggest that supplementation with EPA should be investigated as a potential treatment for adolescent depression.

Liver proteomic analysis reveals the key proteins involved in host immune response to sepsis

Background

Sepsis is a serious infection-induced response in the host, which can result in life-threatening organ dysfunction. It is of great importance to unravel the relationship between sepsis and host immune response and its mechanisms of action. Liver is one of the most vulnerable organs in sepsis, however, the specific pathogenesis of septic liver injury has not been well understood at the protein level.

Methods

A total of 12 healthy Sprague-Dawley (SD) male rats aged from 6 to 8 weeks were adaptively housed in individual cages in the specific pathogen free animal room. These lab rats were grouped into two groups: treatment (N = 9) and control (N = 3) groups; only three mice from the treatment group survived and were used for subsequent experiments. A TMT-based proteomic analysis for liver tissue was performed in the septic rat model.

Results

A total of 37,012 unique peptides were identified, and then 6,166 proteins were determined, among which 5,701 were quantifiable. Compared to the healthy control group, the septic rat group exhibited 162 upregulated and 103 downregulated differentially expressed proteins (DEPs). The upregulated and downregulated DEPs were the most significantly enriched into the complement and coagulation cascades and metabolic pathways. Protein-protein interaction (PPI) analysis further revealed that the upregulated and downregulated DEPs each clustered in a PPI network. Several highly connected upregulated and downregulated DEPs were also enriched into the complement and coagulation cascades pathways and metabolic pathways, respectively. The parallel reaction monitoring (PRM) results of the selected DEPs were consistent with the results of the TMT analysis, supporting the proteomic data.

Conclusion

Our findings highlight the roles of complement and coagulation cascades and metabolic pathways that may play vital roles in the host immune response. The DEPs may serve as clinically potential treatment targets for septic liver injury.

Molecular basis and mechanism of action of Albizia julibrissin in depression treatment and clinical application of its formulae

Albizzia julibrissin is empirically used as an antidepressant in clinical practice. Preclinical studies have indicated that its total extracts or bioactive constituents exerted antidepressant-like responses in animal models, providing the molecular basis to reveal its underlying mechanism of action. While attempts have been made to understand the antidepressant effect of A. julibrissin, many fundamental questions regarding its mechanism of action remain to be addressed at the molecular and systems levels. In this review, we conclusively discussed the mechanism of action of A. julibrissin and A. julibrissin formulae by reviewing recent preclinical and clinical studies conducted by using depressive animal models and depressive patients. Several representative bioactive constituents and formulae were highlighted as examples, and their mechanisms of action were discussed. In addition, some representative A. julibrissin formulae that have been shown to be compatible with conventional antidepressants in clinical practice were also reviewed. Furthermore, we discussed the future research directions to reveal the underlying mechanism of A. julibrissin at the molecular and systems levels in depression treatment. The integrated study using both the molecular and systematic approaches is required not only for improving our understanding of its molecular basis and mechanisms of action, but also for providing a way to discover novel agents or approaches for the effective and systematic treatment of depression.

Sinisan alleviates depression-like behaviors by regulating mitochondrial function and synaptic plasticity in maternal separation rats

BACKGROUND

Sinisan (SNS) consists of four kinds of herbs, which is the core of antidepressant prescription widely used in traditional Chinese medicine clinic treatment for depression induced by early life stress. However, the role and precise mechanism of SNS antidepressant have not yet been elucidated.

PURPOSE

This study aimed to investigate the mechanism SNS on antidepressant of regulating mitochondrial function to improve hippocampal synaptic plasticity.

METHODS

90 Sprague-Dawley (SD) rats male pups on Post-Natal Day (PND) 0 were randomly divided into Control group (ddH₂0), Model group (ddH₂0), Fluoxetine group (5.0 mg/kg fluoxetine), and SNS-L group (2.5 g/kg SNS), SNS-M group (5.0 g/kg SNS) and SNS-H group (10.0 g/kg SNS), 15 animals per group. Maternal separation (MS) from PND1 to PND21, drug intervention from PND60 to PND90, and behavior tests including sucrose preference test, open field test and forced swimming test from PND83 to PND90 were performed. Synaptic structure and mitochondrial structure were observed by TEM. The expression levels of PSD-95 and SYN were detected by immunohistochemistry and western blot test, the adenosine triphosphate (ATP) content in the hippocampus was detected by assay kits, and the expression levels of Mfn2, Drp1 and Fis1 protein were detected by western bolt test.

RESULTS

SNS can alleviate depression-like and anxiety-like behaviors in MS rats, improve the damage of synapses and mitochondria, reduce the decrease of ATP in hippocampus, and reverse the expression levels of PSD-95, SYN, Mfn2, Drp1, and Fis1 proteins.

CONCLUSION

SNS reduced the risk of early life stress induced depression disorder via regulating mitochondrial function and synaptic plasticity. Targeting mitochondrial may be a novel prospective therapeutic avenue for antidepressant.

Tandem mass tag-based proteomics analysis reveals the multitarget mechanisms of Phyllanthus emblica against liver fibrosis

Phyllanthus emblica (PE), a traditional multiethnic herbal medicine, is commonly applied to treat liver diseases. Our previous study demonstrated that aqueous extract of PE (AEPE) could alleviate carbon tetrachloride (CCl₄)-induced liver fibrosis in vivo, but the underlying molecular mechanisms are still unclear. The present study was undertaken to clarify the multitarget mechanisms of PE in treating liver fibrosis by proteomics clues. A CCl₄-induced liver fibrosis rat model was established. The anti-liver fibrosis effects of chemical fractions from AEPE were evaluated by serum biochemical indicators and pathological staining. Additionally, tandem mass tag (TMT) - based quantitative proteomics technology was used to detect the hepatic differentially expressed proteins (DEPs). The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment, gene ontology (GO) enrichment and protein-protein interaction (PPI) network were used to perform bioinformatics analysis of DEPs. Western blot analysis was used to verify the key potential targets regulated by the effective fraction of AEPE. The low-molecular-weight fraction of AEPE (LWPE) was determined to be the optimal anti-liver fibrosis active fraction, that could significantly improve ALT, AST, HA, Col IV, PCIII, LN, Hyp levels and reduce the pathological fibrotic lesion of liver tissue in model rats. A total of 195 DEPs were screened after LWPE intervention. GO analysis showed that the DEPs were related mostly to extracellular matrix organization, actin binding, and extracellular exosomes. KEGG pathway analysis showed that DEPs are mainly related to ECM-receptor interactions, focal adhesion and PI3K-Akt signaling pathway. Combined with the GO, KEGG and Western blot results, COL1A2, ITGAV, TLR2, ACE, and PDGFRB may be potential targets for PE treatment of liver fibrosis. In conclusion, LWPE exerts therapeutic effects through multiple pathways and multiple targets regulation in the treatment of liver fibrosis. This study may provide proteomics clues for the continuation of research on liver fibrosis treatment with PE.

Identification and Characterization of Elevated Expression of Transferrin and Its Receptor TfR1 in Mouse Models of Depression

Depression has become one of the severe mental disorders threatening global human health. In this study, we first used the proteomics approach to obtain the differentially expressed proteins in the liver between naive control and chronic social defeat stress (CSDS) induced depressed mice. We have identified the upregulation of iron binding protein transferrin (TF) in the liver, the peripheral blood, and the brain in CSDS-exposed mice. Furthermore, bioinformatics analysis of the Gene Expression Omnibus (GEO) database from various mouse models of depression revealed the significantly upregulated transcripts of TF and its receptor TfR1 in multiple brain regions in depressed mice. We also used the recombinant TF administration via the tail vein to detect its permeability through the blood-brain barrier (BBB). We demonstrated the permeability of peripheral TF into the brain through the BBB. Together, these results identified the elevated expression of TF and its receptor TfR1 in both peripheral liver and the central brain in CSDS-induced depressed mice, and peripheral administration of TF can be transported into the brain through the BBB. Therefore, our data provide a compelling information for understanding the potential role and mechanisms of the cross-talk between the liver and the brain in stress-induced depression.

The antidepressant-like effect of formononetin on chronic corticosterone-treated mice

Previous studies reported the neuroprotective effects of formononetin (FMN), however, whether it has antidepressant-like effects have not been reported. To evaluate the antidepressant-like effects of FMN, a mice model of depression was established by chronic corticosterone (CORT) injection. The serum corticosterone levels and hippocampal protein expression were detected by ELISA and Western blot. Nissl staining was used to observe the damage of hippocampal neurons and immunofluorescence was used to observe the neurogenesis in the hippocampus. Our results showed that FMN significantly increased the sucrose preference and shorten the immobility time in the forced swimming test in CORT-treated mice. Moreover, FMN reduced the serum corticosterone levels, upregulated the protein expression levels of the glucocorticoid receptor (GR), and brain-derived neurotrophic factor (BDNF) in the hippocampus, protected against the CORT-induced neuronal impairment, and promoted the neurogenesis in the hippocampus. Taken together, the present study was the first to demonstrate the antidepressant-like effects of FMN in the CORT-induced mice model of depression, which may contribute to the discovery of a new candidate for treating depression.

Molecular Mechanisms Associated with Antidepressant Treatment on Major Depression

Major depressive disorder (MDD) is a complex and multifactorial psychiatric disorder that causes serious health, social, and economic concerns worldwide. The main treatment of the symptoms is through antidepressant (AD) drugs. However, not all patients respond properly to these drugs. Omic sciences are widely used to analyze not only biomarkers for the AD response but also their molecular mechanism. In this review, we aimed to focus on omics data to better understand the molecular mechanisms involving AD effects on MDD. We consistently found, from preclinical to clinical data, that glutamatergic transmission, immune/inflammatory processes, energy metabolism, oxidative stress, and lipid metabolism were associated with traditional and potential new ADs. Despite efforts of studies investigating biomarkers of response to ADs, which could contribute to personalized treatment, there is no biomarker panel available for clinical application. From clinical genomic studies, we found that the main findings contribute to the development of pharmacogenomic tests for AD efficacy for each patient. Several studies pointed at DRD2, PXDNL, CACNA1E, and CACNA2D1 genes as potential targets for MDD treatment and the efficacy and rapid-antidepressant effect of ketamine. Finally, more in-depth studies of the molecular targets pointed here are needed to determine the clinical relevance and provide further evidence for precision MDD treatment.

Tandem mass tag-based quantitative proteomic analysis of the liver reveals potential protein targets of Xiaochaihutang in CUMS model of depression

Depression is a global mental disorder disease and greatly threatened human health. Xiaochaihutang (XCHT) has been used successfully in treatment of depression for many years in China, but the mechanism is unclear. Using the chronic unpredictable mild stress (CUMS) mice model of depression, the present study aimed to reveal possible antidepressant mechanisms of XCHT from the perspective of liver by analyzing hepatic proteomics in mice. Bioinformatics analysis identified 31 differentially expressed proteins (DEPs), including 5 upregulated and 26 downregulated proteins, between the CUMS model and XCHT groups. The bile secretion pathway was found by KEGG pathway analysis of these DEPs. Four of the 31 differentially expressed proteins, including 2 active proteins involved in bile secretion, carbonic anhydrase 2 (CA2) and cystic fibrosis transmembrane conductance regulator (CFTR), were selected to verify their genes. Four genes (Cyp7a1, Fxr, Shp and Ntcp) related to bile acid synthesis and transport were further investigated by quantitative real-time polymerase chain reaction (qRT-PCR). Both biochemical tests and gene studies demonstrated that CUMS affected bile acid synthesis and transport, while XCHT regulated this pathway. The results indicated that there may be a potential relationship between CUMS induced depression and hepatic injury caused by increased bile acid, and also provide a novel insight to understand the underlying anti-depression mechanisms of XCHT.

Saikosaponin D Rescues Deficits in Sexual Behavior and Ameliorates Neurological Dysfunction in Mice Exposed to Chronic Mild Stress

Often associated with sexual dysfunction (SD), chronic stress is the main contributing risk factor for the pathogenesis of depression. Radix bupleuri had been widely used in traditional Chinese medicine formulation for the regulation of emotion and sexual activity. As the main active component of Radix bupleuri, saikosaponin D (SSD) has a demonstrated antidepressant effect in preclinical studies. Herein, we sought to investigate the effect of SSD to restore sexual functions in chronically stressed mice and elucidate the potential brain mechanisms that might underly these effects. SSD was gavage administered for three weeks during the induction of chronic mild stress (CMS), and its effects on emotional and sexual behaviors in CMS mice were observed. The medial posterodorsal amygdala (MePD) was speculated to be involved in the manifestation of sexual dysfunctions in CMS mice. Our results revealed that SSD not only alleviated CMS-induced depressive-like behaviors but also rescued CMS-induced low sexual motivation and poor sexual performance. CMS destroyed astrocytes and activated microglia in the MePD. SSD treatment reversed the changes in glial pathology and inhibited neuroinflammatory and oxidative stress in the MePD of CMS mice. The neuronal morphological and functional deficits in the MePD were also alleviated by SSD administration. Our results provide insights into the central mechanisms involving the brain associated with sexual dysfunction. These findings deepen our understanding of SSD in light of the psychopharmacology of stress and sexual disorders, providing a theoretical basis for its potential clinical application.

Chinese Herbal Medicine for the Treatment of Depression: Effects on the Neuroendocrine-Immune Network

The neuroimmune and neuroendocrine systems are two critical biological systems in the pathogenesis of depression. Clinical and preclinical studies have demonstrated that the activation of the neuroinflammatory response of the immune system and hyperactivity of the hypothalamus–pituitary–adrenal (HPA) axis of the neuroendocrine system commonly coexist in patients with depression and that these two systems bidirectionally regulate one another through neural, immunological, and humoral intersystem interactions. The neuroendocrine-immune network poses difficulties associated with the development of antidepressant agents directed toward these biological systems for the effective treatment of depression. On the other hand, multidrug and multitarget Chinese Herbal Medicine (CHM) has great potential to assist in the development of novel medications for the systematic pharmacotherapy of depression. In this narrative essay, we conclusively analyze the mechanisms of action of CHM antidepressant constituents and formulas, specifically through the modulation of the neuroendocrine-immune network, by reviewing recent preclinical studies conducted using depressive animal models. Some CHM herbal constituents and formulas are highlighted as examples, and their mechanisms of action at both the molecular and systems levels are discussed. Furthermore, we discuss the crosstalk of these two biological systems and the systems pharmacology approach for understanding the system-wide mechanism of action of CHM on the neuroendocrine-immune network in depression treatment. The holistic, multidrug, and multitarget nature of CHM represents an excellent example of systems medicine in the effective treatment of depression.

Interaction Mechanisms Between Major Depressive Disorder and Non-alcoholic Fatty Liver Disease

Major depressive disorder (MDD), which is highly associated with non-alcoholic fatty liver disease (NAFLD), has complex pathogenic mechanisms. However, a limited number of studies have evaluated the mutual pathomechanisms involved in MDD and NAFLD development. Chronic stress-mediated elevations in glucocorticoid (GC) levels play an important role in the development of MDD-related NAFLD. Elevated GC levels can induce the release of inflammatory factors and changes in gut permeability. Elevated levels of inflammatory factors activate the hypothalamic-pituitary-adrenal (HPA) axis, which further increases the release of GC. At the same time, changes in gut permeability promote the release of inflammatory factors, which results in a vicious circle among the three, causing disease outbreaks. Even though the specific role of the thyroid hormone (TH) in this pathogenesis has not been fully established, it is highly correlated with MDD and NAFLD. Therefore, changing lifestyles and reducing psychological stress levels are necessary measures for preventing MDD-related NAFLD. Among them, GC inhibitors and receptor antagonists may be key in the alleviation of early and mid-term disease progression. However, combination medications may be important in late-stage diseases, but they are associated with various side effects. Traditional Chinese medicines have been shown to be potential therapeutic alternatives for such complex diseases.