Elucidating the Possible Role of FoxO in Depression

Microglial forkhead box O3a deficiency attenuates LPS-induced neuro-inflammation and depressive-like behaviour through regulating the expression of peroxisome proliferator-activated receptor-γ

BACKGROUND AND PURPOSE

Depression is closely linked with microglial activation and neuro-inflammation. Peroxisome proliferator-activated receptor-γ (PPAR-γ) plays an important role in M2 activation of microglia. Forkhead box (FOX) O3a has been implicated in the regulation of mood-relevant behaviour. However, little is known about the inflammatory mechanisms of in the microglia of the brain. Here, we have investigated the role of microglial FOXO3a/PPAR-γ in the development of depression.

EXPERIMENTAL APPROACH

The effect of FOXO3a on microglia inflammation was analysed in vitro and in lipopolysaccharide (LPS)-induced depression-like behaviours in vivo. ChIP-seq and Dual-luciferase reporter assays were used to confirm the interaction between FOXO3a and PPAR-γ. Behavioural changes were measured, while inflammatory cytokines, microglial phenotype and morphological properties were determined by ELISA, qRT-PCR, western blotting and immunostaining.

KEY RESULTS

Overexpression of FOXO3a significantly attenuated expression of PPAR-γ and enhanced the microglial polarization towards the M1 phenotype, while knockdown of FOXO3a had the opposite effect. FOXO3a binds to the promoters of PPAR-γ and decreases its transcription activity. Importantly, deacetylation and activation of FOXO3a regulate LPS-induced neuro-inflammation by inhibiting the expression of PPAR-γ in microglia cells, supporting the antidepressant potential of histone deacetylase inhibitors. Microglial FOXO3a deficiency in mice alleviated LPS-induced neuro-inflammation and depression-like behaviours but failed to reduce anxiety behaviour, whereas pharmacological inhibition of PPAR-γ by GW9662 restored LPS-induced microglial activation and depressive-like behaviours in microglial FOXO3a-deficient mice.

CONCLUSION AND IMPLICATIONS

FOXO3a/PPAR-γ axis plays an important role in microglial activation and depression, identifying a new therapeutic avenue for the treatment of major depression.

Identifying the differentially expressed peripheral blood microRNAs in psychiatric disorders: a systematic review and meta-analysis

Background

Evidence has suggested that microRNAs (miRNAs) may play an important role in the pathogenesis of psychiatric disorders (PDs), but the results remain inconclusive. We aimed to identify specific differentially expressed miRNAs and their overlapping miRNA expression profiles in schizophrenia (SZ), major depression disorder (MDD), and bipolar disorder (BD), the three major PDs.

Methods

The literatures up to September 30, 2023 related to peripheral blood miRNAs and PDs were searched and screened from multiple databases. The differences in miRNA levels between groups were illustrated by the standardized mean difference (SMD) and 95% confidence interval (95% CI).

Results

In total, 30 peripheral blood miRNAs were included in the meta-analysis, including 16 for SZ, 12 for MDD, and 2 for BD, each was reported in more than 3 independent studies. Compared with the control group, miR-181b-5p, miR-34a-5p, miR-195-5p, miR-30e-5p, miR-7-5p, miR-132-3p, miR-212-3p, miR-206, miR-92a-3p and miR-137-3p were upregulated in SZ, while miR-134-5p, miR-107 and miR-99b-5p were downregulated. In MDD, miR-124-3p, miR-132-3p, miR-139-5p, miR-182-5p, miR-221-3p, miR-34a-5p and miR-93-5p were upregulated, while miR-144-5p and miR-135a-5p were downregulated. However, we failed to identify statistically differentially expressed miRNAs in BD. Interestingly, miR-132-3p and miR-34a-5p were upregulated in both SZ and MDD.

Conclusions

Our study identified 13 differentially expressed miRNAs in SZ and 9 in MDD, among which miR-132-3p and miR-34a-5p were upregulated in both SZ and MDD by systematically analyzing qualified studies. These miRNAs may be used as potential biomarkers for the diagnosis of SZ and MDD in the future.

Systematic Review Registration

http://www.crd.york.ac.uk/PROSPERO, identifier CRD42023486982.

Marine natural products: potential agents for depression treatment

Depression is a common psychiatric disorder. Due to the disadvantages of current clinical drugs, including poor efficacy and unnecessary side effects, research has shifted to novel natural products with minimal or no adverse effects as therapeutic alternatives. The ocean is a vast ecological home, with a wide variety of organisms that can produce a large number of natural products with unique structures, some of which have neuroprotective effects and are a valuable source for the development of new drugs for depression. In this review, we analyzed preclinical and clinical studies of natural products derived from marine organisms with antidepressant potential, including the effects on the pathophysiology of depression, and the underlying mechanisms of these effects. It is expected to provide a reference for the development of new antidepressant drugs.

Stroke Related Brain-Heart Crosstalk: Pathophysiology, Clinical Implications, and Underlying Mechanisms

The emergence of acute ischemic stroke (AIS) induced cardiovascular dysfunctions as a bidirectional interaction has gained paramount importance in understanding the intricate relationship between the brain and heart. Post AIS, the ensuing cardiovascular dysfunctions encompass a spectrum of complications, including heart attack, congestive heart failure, systolic or diastolic dysfunction, arrhythmias, electrocardiographic anomalies, hemodynamic instability, cardiac arrest, among others, all of which are correlated with adverse outcomes and mortality. Mounting evidence underscores the intimate crosstalk between the heart and the brain, facilitated by intricate physiological and neurohumoral complex networks. The primary pathophysiological mechanisms contributing to these severe cardiac complications involve the hypothalamic-pituitary-adrenal (HPA) axis, sympathetic and parasympathetic hyperactivity, immune and inflammatory responses, and gut dysbiosis, collectively shaping the stroke-related brain-heart axis. Ongoing research endeavors are concentrated on devising strategies to prevent AIS-induced cardiovascular dysfunctions. Notably, labetalol, nicardipine, and nitroprusside are recommended for hypertension control, while β-blockers are employed to avert chronic remodeling and address arrhythmias. However, despite these therapeutic interventions, therapeutic targets remain elusive, necessitating further investigations into this complex challenge. This review aims to delineate the state-of-the-art pathophysiological mechanisms in AIS through preclinical and clinical research, unraveling their intricate interplay within the brain-heart axis, and offering pragmatic suggestions for managing AIS-induced cardiovascular dysfunctions.

Acne Transcriptomics: Fundamentals of Acne Pathogenesis and Isotretinoin Treatment

This review on acne transcriptomics allows for deeper insights into the pathogenesis of acne and isotretinoin's mode of action. Puberty-induced insulin-like growth factor 1 (IGF-1), insulin and androgen signaling activate the kinase AKT and mechanistic target of rapamycin complex 1 (mTORC1). A Western diet (hyperglycemic carbohydrates and milk/dairy products) also co-stimulates AKT/mTORC1 signaling. The AKT-mediated phosphorylation of nuclear FoxO1 and FoxO3 results in their extrusion into the cytoplasm, a critical switch which enhances the transactivation of lipogenic and proinflammatory transcription factors, including androgen receptor (AR), sterol regulatory element-binding transcription factor 1 (SREBF1), peroxisome proliferator-activated receptor γ (PPARγ) and signal transducer and activator of transcription 3 (STAT3), but reduces the FoxO1-dependent expression of GATA binding protein 6 (GATA6), the key transcription factor for infundibular keratinocyte homeostasis. The AKT-mediated phosphorylation of the p53-binding protein MDM2 promotes the degradation of p53. In contrast, isotretinoin enhances the expression of p53, FoxO1 and FoxO3 in the sebaceous glands of acne patients. The overexpression of these proapoptotic transcription factors explains isotretinoin's desirable sebum-suppressive effect via the induction of sebocyte apoptosis and the depletion of BLIMP1(+) sebocyte progenitor cells; it also explains its adverse effects, including teratogenicity (neural crest cell apoptosis), a reduced ovarian reserve (granulosa cell apoptosis), the risk of depression (the apoptosis of hypothalamic neurons), VLDL hyperlipidemia, intracranial hypertension and dry skin.

Changes in Multiple microRNA Levels with Antidepressant Treatment Are Associated with Remission and Interact with Key Pathways: A Comprehensive microRNA Analysis

Individual treatment outcomes to antidepressants varies widely, yet the determinants to this difference remain elusive. MicroRNA (miRNA) gene expression regulation in major depressive disorder (MDD) has attracted interest as a biomarker. This 4-week randomized controlled trial examined changes in the plasma miRNAs that correlated with the treatment outcomes of mirtazapine (MIR) and selective serotonin reuptake inhibitor (SSRI) monotherapy. Pre- and post- treatment, we comprehensively analyzed the miRNA levels in MDD patients, and identified the gene pathways linked to these miRNAs in 46 patients. Overall, 141 miRNA levels significantly demonstrated correlations with treatment remission after 4 weeks of MIR, with miR-1237-5p showing the most robust and significant correlation after Bonferroni correction. These 141 miRNAs displayed a negative correlation with remission, indicating a decreasing trend. These miRNAs were associated with 15 pathways, including TGF-β and MAPK. Through database searches, the genes targeted by these miRNAs with the identified pathways were compared, and it was found that MAPK1, IGF1, IGF1R, and BRAF matched. Alterations in specific miRNAs levels before and after MIR treatment correlated with remission. The miRNAs mentioned in this study have not been previously reported. No other studies have investigated treatment with MIR. The identified miRNAs also correlated with depression-related genes and pathways.

Ring neurons in the Drosophila central complex act as a rheostat for sensory modulation of aging

Sensory perception modulates aging, yet we know little about how. An understanding of the neuronal mechanisms through which animals orchestrate biological responses to relevant sensory inputs would provide insight into the control systems that may be important for modulating lifespan. Here, we provide new awareness into how the perception of dead conspecifics, or death perception, which elicits behavioral and physiological effects in many different species, affects lifespan in the fruit fly, Drosophila melanogaster. Previous work demonstrated that cohousing Drosophila with dead conspecifics decreases fat stores, reduces starvation resistance, and accelerates aging in a manner that requires both sight and the serotonin receptor 5-HT2A. In this manuscript, we demonstrate that a discrete, 5-HT2A-expressing neural population in the ellipsoid body (EB) of the Drosophila central complex, identified as R2/R4 neurons, acts as a rheostat and plays an important role in transducing sensory information about the presence of dead individuals to modulate lifespan. Expression of the insulin-responsive transcription factor foxo in R2/R4 neurons and insulin-like peptides dilp3 and dilp5, but not dilp2, are required, with the latter likely altered in median neurosecretory cells (MNCs) after R2/R4 neuronal activation. These data generate new insights into the neural underpinnings of how perceptive events may impact aging and physiology across taxa.

Lasia spinosa (L.) thw. attenuates chemically induced behavioral disorders in experimental and computational models

Lasia spinosa (L.) Thw. (L. spinosa) is widely used as a folk remedy for different physical ailments, and its neurological effects have yet to be assessed. Phytochemicals status of L. spinosa was evaluated by GC-MS analysis. Membrane stabilization test, elevated plus maze (EPM) tests and hole board tests (HBT), tail suspension tests (TST) and thiopental sodium-induced sleeping tests (TISTT) were used to assess anti-inflammatory, anxiolytic and anti-depressant activity. Fourteen compounds have been recorded from GC-MS analysis. The LSCTF showed 68.66 ± 2.46% hemolysis protections (p < 0.05) at 500 μg/mL, whereas LSCHF and LSNHF demonstrated efficiency rates of 68.6 ± 1.46% and 52.46 ± 5.28%, respectively. During EPM tests, LSNHF and LSCTF significantly (p < 0.001) increased the time spent in the open arm (59.88 ± 0.65 s and 50.77 ± 0.67 s, respectively) at the dosages of 400 mg/kg. In HBT, samples exhibited dose-dependent anxiolytic activity. LSNHF and LSCTF showed a significant (p < 0.001) hole poking tendency and a high number of head dips (78.66 ± 1.05 and 65.17 ± 0.96, respectively) at the higher dose. In TST, at 400 mg/kg dose demonstrated significantly (p < 0.001) smaller amounts of time immobile, at 81.33 ± 1.67 s and 83.50 ± 1.90 s, respectively, compared to the control group. A consistent finding was also observed in TISTT. The computer-assisted studies on the identified compounds strongly support the aforementioned biological activities, indicating that L. spinosa has potential as a source of medication for treating neuropsychiatric and inflammatory diseases.

Kaixin Jieyu Granule attenuates neuroinflammation-induced depressive-like behavior through TLR4/PI3K/AKT/FOXO1 pathway: a study of network pharmacology and experimental validation

BACKGROUND

Kaixin Jieyu Granule (KJG), an improved formula of Kai-xin-san and Si-ni-san, is a highly effective formula with demonstrated efficacy in preventing depression in previous studies. However, the underlying molecular mechanisms of KJG's antidepressant effects on inflammatory molecules remain unclear. This study aimed to explore the therapeutic effects of KJG on depression using network pharmacology and experimental validation.

METHODS

We employed a multi-faceted approach, combining high-performance liquid chromatography (HPLC), network pharmacology, and molecular docking, to unravel the underlying mechanisms of KJG's anti-depressant effects. To confirm our findings, we conducted at least two independent in vivo experiments on mice, utilizing both the chronic unpredictable mild stress (CUMS)-induced and lipopolysaccharide (LPS)-induced models. Furthermore, the results of in vivo experiments were verified by in vitro assays. Behavioral tests were utilized to evaluate depression-like behaviors, while Nissl staining was used to assess morphological changes in the hippocampus. Pro-inflammatory cytokines and pathway-related protein expressions were determined using a combination of immunofluorescence staining, enzyme-linked immunosorbent assay (ELISA), and Western Blotting (WB).

RESULTS

Our network-based approaches indicated that ginsenoside Rg1 (GRg1) and saikosaponin d (Ssd) are the major constituents of KJG that exert an anti-depressant effect by regulating TLR4, PI3K, AKT1, and FOXO1 targets through the toll-like receptor, PI3K/AKT, and FoxO pathways. In vivo, KJG can attenuate depression-like behaviors, protect hippocampal neuronal cells, and reduce the production of pro-inflammatory mediators (TNF-α, IL-6, and IL-1β) by repressing TLR4 expression, which was regulated by the inhibition of FOXO1 through nuclear exportation. Furthermore, KJG increases the expression levels of PI3K, AKT, p-PI3K, p-AKT, and p-PTEN. Our in vitro assays are consistent with our in vivo studies. On the other hand, the above effects can be reversed by applying TAK242 and LY294002.

CONCLUSION

Our findings suggest that KJG can exert anti-depressant effects by regulating neuroinflammation through the PI3K/AKT/FOXO1 pathway by suppressing TLR4 activation. The study's findings reveal novel mechanisms underlying the anti-depressant effects of KJG, presenting promising avenues for the development of targeted therapeutic approaches for depression.

Role of Hippocampal miR-132-3p in Modifying the Function of Protein Phosphatase Mg2+/Mn2+-dependent 1 F in Depression

Depression is a common, severe, and debilitating psychiatric disorder of unclear etiology. Our previous study has shown that protein phosphatase Mg2+/Mn2+-dependent 1F (PPM1F) in the hippocampal dentate gyrus (DG) displays significant regulatory effects in depression-related behaviors. miR-132-3p plays a potential role in the etiology of depression. This study explored the effect of miR-132-3p on the onset of depression and the possible underlying mechanism for modulating PPM1F expression during the pathology of depression. We found that miR-132-3p levels in the hippocampus of depressed mice subjected to chronic unpredictable stress (CUS) were dramatically reduced, which were correlated with depression-related behaviors. Knockdown of miR-132-3p in hippocampal DG resulted in depression-related phenotypes and increased susceptibility to stress. miR-132-3p overexpression in hippocampal DG alleviated CUS-induced depression-related performance. We then screened out the potential target genes of miR-132-3p, and we found that the expression profiles of sterol regulatory element-binding transcription factor 1 (Srebf1) and forkhead box protein O3a (FOXO3a) were positively correlated with PPM1F under the condition of miR-132-3p knockdown. Finally, as anticipated, we revealed that the activities of Ca2+/calmodulin-dependent protein kinase II (CAMKII) and adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) were reduced, which underlies the target signaling pathway of PPM1F. In conclusion, our study suggests that miR-132-3p was designed to regulate depression-related behaviors by indirectly regulating PPM1F and targeting Srebf1 and FOXO3a, which have been linked to the pathogenesis and treatment of depression.

Forkhead Box O Signaling Pathway in Skeletal Muscle Atrophy

Skeletal muscle atrophy is the consequence of protein degradation exceeding protein synthesis because of disease, aging, and physical inactivity. Patients with skeletal muscle atrophy have decreased muscle mass and fiber cross-sectional area, and experience reduced survival quality and motor function. The forkhead box O (FOXO) signaling pathway plays an important role in the pathogenesis of skeletal muscle atrophy by regulating E3 ubiquitin ligases and some autophagy factors. However, the mechanism of FOXO signaling pathway leading to skeletal muscle atrophy is still unclear. The development of treatment strategies for skeletal muscle atrophy has been a thorny clinical problem. FOXO-targeted therapy to treat skeletal muscle atrophy is a promising approach, and an increasing number of relevant studies have been reported. This article reviews the mechanism and therapeutic targets of the FOXO signaling pathway mediating skeletal muscle atrophy, and provides ideas for the clinical treatment of this condition.

Exploring the role of biologics in depression

Depression is a chronic and prevalent neuropsychiatric disorder; clinical symptoms include excessive sad mood, anhedonia, increased anxiety, disturbed sleep, and cognitive deficits. The exact etiopathogenesis of depression is not well understood. Studies have suggested that tumor necrosis factor-alpha (TNF-α) and interleukins (ILs) perform vital roles in the pathogenesis and treatment of depression. Increasing evidence suggests the upregulation of TNF-α and ILs expression in patients with depression. Therefore, biologics like TNF inhibitors (etanercept, infliximab, adalimumab) and IL inhibitors (ustekinumab) have become key compounds in the treatment of depression. Interestingly, treatment with an antidepressant has been found to decrease the TNF-α level and improve depression-like behaviors in several preclinical and clinical studies. In the current article, we have reviewed the recent findings linking TNF-α and the pathogenesis of depression proving TNF-α inhibitors as potential new therapeutic agents. Animal models and clinical studies further support that TNF-α inhibitors are effective in ameliorating depression-like behaviors. Moreover, studies showed that peripheral injection of TNF-α exhibits depressive symptoms. These symptoms have been improved by treatment with TNF-α inhibitors. Hence suggesting TNF-α inhibitors as potential new antidepressants for the management of depressive disorder.

Exploring the mechanisms of action of Cordyceps sinensis for the treatment of depression using network pharmacology and molecular docking

Background

Depression is the most common type of psychological disorder, with continuous, prolonged, and persistent bad moods as the main clinical feature. Cordyceps sinensis is a complex consisting of the ascospores and bodies of insect larvae from the Hepialidae family that have been parasitized by Cordyceps sinensis militaris. Previous studies have reported that this herb has antidepressant activity. The present study used network pharmacology and molecular docking techniques to investigate the potential antidepressant mechanisms of Cordyceps sinensis.

Methods

The active ingredients of Cordycepssinensis were identified using the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP) and the potential targets were predicted using the PharmMapper platform. The GeneCards database was then used to obtain sub-targets for depression. Common targets were screened and enrichment analyses were performed using the Metascape platform. Finally, the relationship between the active ingredients and the core targets were verified by molecular docking.

Results

Through network pharmacological analysis, 7 active ingredients in Cordyceps sinensis and 41 common targets of drugs and diseases were identified. The active ingredients of Cordyceps sinensis may exert antidepressant effects by acting on important targets such as catalase (CAT), CREB binding protein (CREBBP), epidermal growth factor (EGF), and E1A binding protein P300 (EP300), and by modulating the signaling pathways in which these targets are involved. Subsequently, the core targets were docked to the active ingredients and good binding was observed.

Conclusions

The active ingredients of Cordycepssinensis may exert antidepressant effects by regulating the CREB binding protein and anti-oxidative stress effects. The foxo signaling pathway (hsa04068), hypoxia-inducible factor 1 (HIF-1) signaling pathway (hsa04066), and Huntington’s disease (hsa05016) may be involved in the underlying mechanisms of Cordycepssinensis. The joint application of network pharmacology and molecular docking provides a new approach to study the mechanisms of action of traditional Chinese medicine. Cordyceps sinensis may play an important role in the future treatment of patients with depression.

5-HT Receptors and the Development of New Antidepressants

Serotonin modulates several physiological and cognitive pathways throughout the human body that affect emotions, memory, sleep, and thermal regulation. The complex nature of the serotonergic system and interactions with other neurochemical systems indicate that the development of depression may be mediated by various pathomechanisms, the common denominator of which is undoubtedly the disturbed transmission in central 5-HT synapses. Therefore, the deliberate pharmacological modulation of serotonergic transmission in the brain seems to be one of the most appropriate strategies for the search for new antidepressants. As discussed in this review, the serotonergic system offers great potential for the development of new antidepressant therapies based on the combination of SERT inhibition with different pharmacological activity towards the 5-HT system. The aim of this article is to summarize the search for new antidepressants in recent years, focusing primarily on the possibility of benefiting from interactions with various 5-HT receptors in the pharmacotherapy of depression.