The potential of baicalin to enhance neuroprotection and mitochondrial function in a human neuronal cell model

Baicalin is a flavone glycoside derived from flowering plants belonging to the Scutellaria genus. Previous studies have reported baicalin's anti-inflammatory and neuroprotective properties in rodent models, indicating the potential of baicalin in neuropsychiatric disorders where alterations in numerous processes are observed. However, the extent of baicalin's therapeutic effects remains undetermined in a human cell model, more specifically, neuronal cells to mimic the brain environment in vitro. As a proof of concept, we treated C8-B4 cells (murine cell model) with three different doses of baicalin (0.1, 1 and 5 μM) and vehicle control (DMSO) for 24 h after liposaccharide-induced inflammation and measured the levels of TNF-α in the medium by ELISA. NT2-N cells (human neuronal-like cell model) underwent identical baicalin treatment, followed by RNA extraction, genome-wide mRNA expression profiles and gene set enrichment analysis (GSEA). We also performed neurite outgrowth assays and mitochondrial flux bioanalysis (Seahorse) in NT2-N cells. We found that in C8-B4 cells, baicalin at ≥ 1 μM exhibited anti-inflammatory effects, lowering TNF-α levels in the cell culture media. In NT2-N cells, baicalin positively affected neurite outgrowth and transcriptionally up-regulated genes in the tricarboxylic acid cycle and the glycolysis pathway. Similarly, Seahorse analysis showed increased oxygen consumption rate in baicalin-treated NT2-N cells, an indicator of enhanced mitochondrial function. Together, our findings have confirmed the neuroprotective and mitochondria enhancing effects of baicalin in human-neuronal like cells. Given the increased prominence of mitochondrial mechanisms in diverse neuropsychiatric disorders and the paucity of mitochondrial therapeutics, this suggests the potential therapeutic application of baicalin in human neuropsychiatric disorders where these processes are altered.

Use of a gene expression signature to identify trimetazidine for repurposing to treat bipolar depression

OBJECTIVES

The aim of this study was to repurpose a drug for the treatment of bipolar depression.

METHODS

A gene expression signature representing the overall transcriptomic effects of a cocktail of drugs widely prescribed to treat bipolar disorder was generated using human neuronal-like (NT2-N) cells. A compound library of 960 approved, off-patent drugs were then screened to identify those drugs that affect transcription most similar to the effects of the bipolar depression drug cocktail. For mechanistic studies, peripheral blood mononuclear cells were obtained from a healthy subject and reprogrammed into induced pluripotent stem cells, which were then differentiated into co-cultured neurons and astrocytes. Efficacy studies were conducted in two animal models of depressive-like behaviours (Flinders Sensitive Line rats and social isolation with chronic restraint stress rats).

RESULTS

The screen identified trimetazidine as a potential drug for repurposing. Trimetazidine alters metabolic processes to increase ATP production, which is thought to be deficient in bipolar depression. We showed that trimetazidine increased mitochondrial respiration in cultured human neuronal-like cells. Transcriptomic analysis in induced pluripotent stem cell-derived neuron/astrocyte co-cultures suggested additional mechanisms of action via the focal adhesion and MAPK signalling pathways. In two different rodent models of depressive-like behaviours, trimetazidine exhibited antidepressant-like activity with reduced anhedonia and reduced immobility in the forced swim test.

CONCLUSION

Collectively our data support the repurposing of trimetazidine for the treatment of bipolar depression.

Metergoline Shares Properties with Atypical Antipsychotic Drugs Identified by Gene Expression Signature Screen

Novel approaches are required to find new treatments for schizophrenia and other neuropsychiatric disorders. This study utilised a combination of in vitro transcriptomics and in silico analysis with the BROAD Institute's Connectivity Map to identify drugs that can be repurposed to treat psychiatric disorders. Human neuronal (NT2-N) cells were treated with a combination of atypical antipsychotic drugs commonly used to treat psychiatric disorders (such as schizophrenia, bipolar disorder, and major depressive disorder), and differential gene expression was analysed. Biological pathways with an increased gene expression included circadian rhythm and vascular endothelial growth factor signalling, while the adherens junction and cell cycle pathways were transcriptionally downregulated. The Connectivity Map (CMap) analysis screen highlighted drugs that affect global gene expression in a similar manner to these psychiatric disorder treatments, including several other antipsychotic drugs, confirming the utility of this approach. The CMap screen specifically identified metergoline, an ergot alkaloid currently used to treat seasonal affective disorder, as a drug of interest. In mice, metergoline dose-dependently reduced MK-801- or methamphetamine-induced locomotor hyperactivity confirming the potential of metergoline to treat positive symptoms of schizophrenia in an animal model. Metergoline had no effects on prepulse inhibition deficits induced by MK-801 or methamphetamine. Taken together, metergoline appears a promising drug for further studies to be repurposed as a treatment for schizophrenia and possibly other psychiatric disorders.

Lipopolysaccharide-binding protein and bone health: data from a population-based sample of men

We aimed to investigate the association between serum lipopolysaccharide-binding protein (LBP) and bone health in men. LBP was associated with lower bone density at the mid-forearm and the quantitative heel ultrasound measure, broadband ultrasound attenuation, for heavier participants. Data do not support clear associations between serum LBP and bone health.

INTRODUCTION

The objective of this study was to investigate the association between serum lipopolysaccharide-binding protein (LBP) and potential downstream effects on skeletal density, quality, and turnover in a population-based sample of men.

METHODS

This cross-sectional study utilised data from 1149 men (aged 20-96 year) enrolled in the Geelong Osteoporosis Study. Blood samples were obtained and lipopolysaccharide-binding protein (LBP), bone resorption marker, C-telopeptide (CTx), and formation marker, type 1 procollagen amino-terminal-propeptide (P1NP), were measured. Bone mineral density (BMD) was measured using dual-energy X-ray absorptiometry. Stiffness Index (SI), broadband ultrasound attenuation (BUA), and speed of sound (SOS) were derived from quantitative heel ultrasound (QUS). Linear regression models were developed to test associations between log-transformed LBP (ln-LBP), BMD, QUS, and bone turnover, after adjusting for potential covariates.

RESULTS

Serum LBP ranged from 1.07-208.53 ng/mL (median 16.53 ng/mL). Those with higher levels were older, less mobile, and had lower BMD at the mid-forearm, otherwise, groups were similar. Before and after adjustment for age, ln-LBP was associated with lower BMD at the spine, total body, and mid-forearm. Further adjustment for weight attenuated associations at the spine and total body, yet the relationship at the mid-forearm was sustained (β - 0.014 ± 0.004, p = 0.001). SOS and SI were not associated with ln-LBP either before or after adjustment for age; however, weight was identified as an effect modifier in the relationship between ln-LBP and BUA. An association was observed for those weighing greater than 82.7 kg (β 3.366 ± 0.929, p < 0.001), after adjustment for potential covariates. Neither bone turnover marker was associated with ln-LBP.

CONCLUSION

Our data do not support a clear association between serum LBP and measures of bone health in this sample of men.

Metformin is Protective Against the Development of Mood Disorders

INTRODUCTION

Mood disorders are a major cause of disability, and current treatment options are inadequate for reducing the burden on a global scale. The aim of this project was to identify drugs suitable for repurposing to treat mood disorders.

METHODS

This mixed-method study utilized gene expression signature technology and pharmacoepidemiology to investigate drugs that may be suitable for repurposing to treat mood disorders.

RESULTS

The transcriptional effects of a combination of drugs commonly used to treat mood disorders included regulation of the steroid and terpenoid backbone biosynthesis pathways, suggesting a mechanism involving cholesterol biosynthesis, and effects on the thyroid hormone signaling pathway. Connectivity Map analysis highlighted metformin, an FDA-approved treatment for type 2 diabetes, as a drug having global transcriptional effects similar to the mood disorder drug combination investigated. In a retrospective cohort study, we found evidence that metformin is protective against the onset of mood disorders.

DISCUSSION

These results provide proof-of-principle of combining gene expression signature technology with pharmacoepidemiology to identify potential novel drugs for treating mood disorders. Importantly, metformin may have utility in the treatment of mood disorders, warranting future randomized controlled trials to test its efficacy.

Adjunctive minocycline for major depressive disorder: A sub-study exploring peripheral immune-inflammatory markers and associated treatment response

Background

Adjunctive minocycline shows promise in treating affective and psychotic disorders; however, the therapeutic mechanism remains unclear. Identifying relevant biomarkers may enhance the efficacy of novel adjunctive treatment candidates. We thus investigated the peripheral immune-inflammatory profile in a randomized controlled trial (RCT) of minocycline in major depressive disorder (MDD).

Methods

This sub-study investigated serum samples from a RCT evaluating minocycline (200 mg/day, 12 weeks) in addition to treatment as usual for MDD (ACTRN12612000283875). Of the original sample (N = 71), serum assays were conducted in 47 participants (placebo n = 24; minocycline n = 23) targeting an array of 46 immune-inflammatory analytes including cytokines, chemokines, and acute-phase reactants. General estimating equations (GEE) were used to assess whether analyte concentration at baseline (effect modification) and change in analytes (change association) influenced change in Montgomery-Åsberg Depression Rating Scale (MADRS) score over time. The Benjamini-Hochberg approach was applied when adjusting for false discovery rates (FDR).

Results

GEE models revealed several interaction effects. After adjusting for FDR several change association-models survived correction. However, no such models remained significant for effect modification. Three-way group × time × marker interactions were significant for complement C3 (B = -10.46, 95%CI [-16.832, -4.095], q = 0.019) and IL-1Ra (B = -9.008, 95%CI [-15.26, -2.751], q = 0.036). Two-way group × biomarker interactions were significant for ICAM-1/CD54 (B = -0.387, 95%CI [-0.513, -0.26], q < 0.001) and IL-8/CXCL8 (B = -4.586, 95%CI [-7.698, -1.475], q = 0.036) indicating that increases in the serum concentration of these analytes were associated with an improvement in MADRS scores in the minocycline group (compared with placebo).

Conclusions

Change in complement C3, IL-1Ra, IL-8/CXCL8, and ICAM-1 may be associated with greater change in depressive scores following adjunctive minocycline treatment in MDD. Further investigations are needed to assess the utility of these biomarkers.

The role of metformin as a treatment for neuropsychiatric illness

Advances in psychopharmacology have been significantly slower to evolve than in other disciplines of medicine and therefore investigation into novel therapeutic approaches is required. Additionally, concurrent metabolic conditions are prevalent among people with mental disorders. Metformin is a widely used hypoglycaemic agent that is now being studied for use beyond diabetes management. Evidence is emerging that metformin has multiple effects on diverse neurobiological pathways and consequently may be repurposed for treating mental illness. Metformin may have beneficial neuroimmunological, neuroplastic, neuro-oxidative and neuro-nitrosative effects across a range of psychiatric and neurodegenerative illnesses. Mechanisms include glucose lowering effects and effects on AMP-activated protein kinase (AMPK) signalling, however the best evidence for clinical benefit is through the glucose lowering effects, with other mechanisms less supported by the current evidence base. This narrative review aims to draw together the existing evidence for use of metformin as a psychopharmaceutical and present the role of metformin in the context of physical and psychiatric ill health, including metabolic, endocrinological and cancer domains. It not only has therapeutic potential in medical comorbidity but may have potential in core illness domains.

Effects of Psychotropic Drugs on Ribosomal Genes and Protein Synthesis

Altered protein synthesis has been implicated in the pathophysiology of several neuropsychiatric disorders, particularly schizophrenia. Ribosomes are the machinery responsible for protein synthesis. However, there remains little information on whether current psychotropic drugs affect ribosomes and contribute to their therapeutic effects. We treated human neuronal-like (NT2-N) cells with amisulpride (10 µM), aripiprazole (0.1 µM), clozapine (10 µM), lamotrigine (50 µM), lithium (2.5 mM), quetiapine (50 µM), risperidone (0.1 µM), valproate (0.5 mM) or vehicle control for 24 h. Transcriptomic and gene set enrichment analysis (GSEA) identified that the ribosomal pathway was altered by these drugs. We found that three of the eight drugs tested significantly decreased ribosomal gene expression, whilst one increased it. Most changes were observed in the components of cytosolic ribosomes and not mitochondrial ribosomes. Protein synthesis assays revealed that aripiprazole, clozapine and lithium all decreased protein synthesis. Several currently prescribed psychotropic drugs seem to impact ribosomal gene expression and protein synthesis. This suggests the possibility of using protein synthesis inhibitors as novel therapeutic agents for neuropsychiatric disorders.

Common effects of bipolar disorder medications on expression quantitative trait loci genes

The molecular mechanism(s) underpinning the clinical efficacy of the current drugs for bipolar disorder (BD) are largely unknown. This study evaluated the transcriptional perturbations potentially playing roles in the therapeutic efficacy of four commonly prescribed psychotropic drugs used to treat BD. NT2-N cells were treated with lamotrigine, lithium, quetiapine, valproate or vehicle control for 24 h. Genome-wide mRNA expression was quantified by RNA-sequencing. Incorporating drug-induced gene expression profiles with BD-associated transcriptional changes from post-mortem brains, we identified potential therapeutic-relevant genes associated with both drug treatments and BD pathophysiology and focused on expression quantitative trait loci (eQTL) genes with genome-wide association with BD. Each eQTL gene was ranked based on its potential role in the therapeutic effect across multiple drugs. The expression of highest-ranked eQTL genes were measured by RT-qPCR to confirm their transcriptional changes observed in RNA-seq. We found 775 genes for which at least 2 drugs reversed expression levels relative to the differential expression in post-mortem brains. Pathway analysis identified enriched biological processes highlighting mitochondrial and endoplasmic reticulum function. Differential expression of SRPK2 and CHDH was confirmed by RT-qPCR following multiple-dose treatments. We pinpointed potential genes involved in the beneficial effects of drugs used for BD and their main associated biological pathways. CHDH, which encodes a mitochondrial protein, had a significant dose-responsive downregulation following treatment with increasing doses of quetiapine and lamotrigine, which in combination with the enriched mitochondrial pathways suggests potential therapeutic roles and demand more studies on mitochondrial involvement in BD to identify novel treatment targets.

Co-Expression Networks Unveiled Long Non-Coding RNAs as Molecular Targets of Drugs Used to Treat Bipolar Disorder

Long non-coding RNAs (lncRNAs) may play a role in psychiatric diseases including bipolar disorder (BD). We investigated mRNA-lncRNA co-expression patterns in neuronal-like cells treated with widely prescribed BD medications. The aim was to unveil insights into the complex mechanisms of BD medications and highlight potential targets for new drug development. Human neuronal-like (NT2-N) cells were treated with either lamotrigine, lithium, quetiapine, valproate or vehicle for 24 h. Genome-wide mRNA expression was quantified for weighted gene co-expression network analysis (WGCNA) to correlate the expression levels of mRNAs with lncRNAs. Functional enrichment analysis and hub lncRNA identification was conducted on key co-expressed modules associated with the drug response. We constructed lncRNA-mRNA co-expression networks and identified key modules underlying these treatments, as well as their enriched biological functions. Processes enriched in key modules included synaptic vesicle cycle, endoplasmic reticulum-related functions and neurodevelopment. Several lncRNAs such as GAS6-AS1 and MIR100HG were highlighted as driver genes of key modules. Our study demonstrates the key role of lncRNAs in the mechanism(s) of action of BD drugs. Several lncRNAs have been suggested as major regulators of medication effects and are worthy of further investigation as novel drug targets to treat BD.

Intertwined associations between oxidative and nitrosative stress and endocannabinoid system pathways: Relevance for neuropsychiatric disorders

The endocannabinoid system (ECS) appears to regulate metabolic, cardiovascular, immune, gastrointestinal, lung, and reproductive system functions, as well as the central nervous system. There is also evidence that neuropsychiatric disorders are associated with ECS abnormalities as well as oxidative and nitrosative stress pathways. The goal of this mechanistic review is to investigate the mechanisms underlying the ECS's regulation of redox signalling, as well as the mechanisms by which activated oxidative and nitrosative stress pathways may impair ECS-mediated signalling. Cannabinoid receptor (CB)1 activation and upregulation of brain CB2 receptors reduce oxidative stress in the brain, resulting in less tissue damage and less neuroinflammation. Chronically high levels of oxidative stress may impair CB1 and CB2 receptor activity. CB1 activation in peripheral cells increases nitrosative stress and inducible nitric oxide (iNOS) activity, reducing mitochondrial activity. Upregulation of CB2 in the peripheral and central nervous systems may reduce iNOS, nitrosative stress, and neuroinflammation. Nitrosative stress may have an impact on CB1 and CB2-mediated signalling. Peripheral immune activation, which frequently occurs in response to nitro-oxidative stress, may result in increased expression of CB2 receptors on T and B lymphocytes, dendritic cells, and macrophages, reducing the production of inflammatory products and limiting the duration and intensity of the immune and oxidative stress response. In conclusion, high levels of oxidative and nitrosative stress may compromise or even abolish ECS-mediated redox pathway regulation. Future research in neuropsychiatric disorders like mood disorders and deficit schizophrenia should explore abnormalities in these intertwined signalling pathways.

Cognition-immune interactions between executive function and working memory, tumour necrosis factor-alpha (TNF-alpha) and soluble TNF receptors (sTNFR1 and sTNFR2) in bipolar disorder

OBJECTIVES

This study examined cognition-immune interactions, specifically executive function, working memory, peripheral levels of tumour necrosis factor-alpha (TNF-α), and soluble tumour necrosis factor receptors-1 and -2 (sTNFR1 and 2) levels in bipolar disorder (BD) patients in comparison with controls.

METHODS

Thirty-one BD participants and twenty-seven controls participated in the study. The neurocognitive assessment was performed through three of CogState Research Battery^TM tasks for executive function and working memory. Plasma levels of TNF-α, sTNFR1, and sTNFR2 were measured after overnight fasting. Sociodemographic data and symptom severity of depression and mania were assessed.

RESULTS

BD presented a significantly worse performance in the working memory task (p = .005) and higher levels of TNF-α (p = .043) in comparison to controls. A trend level of significance was found for sTNFR1 between groups (p = .082). Among BD participants, there were significant correlations between sTNFR2 and neurocognitive tasks (Groton Maze Learning Task: ρ = .54, p = .002; Set-Shifting Task: ρ = .37, p = .042; and the Two-Back Task: ρ = -.49, p = .005), and between sTNFR1 and mania, depression and anxiety symptoms (respectively ρ = .37, p = .038; ρ = -.38, p = .037; and ρ = .42, p = .002).

CONCLUSION

TNF-α and its receptors might be an important variable in cognitive impairment in BD. Future studies might focus on the development of anti-inflammatory therapeutic targets for cognitive dysfunction in BD.

A placebo-controlled, randomised pilot trial of N-acetylcysteine or placebo for cessation of tobacco smoking

Smoking represents a significant health threat to the population, however there remains a core group of consistent smokers that are largely unable to break the addiction. Novel therapies are required to assist this group with cessation. N-acetylcysteine (NAC) is a nutraceutical supplement that has shown efficacy compared to placebo in previous pilot studies for assisting smokers to quit or reduce their consumption of cigarettes. A double-blind, randomised trial with a treatment period of 16 weeks and a final follow-up at 42 weeks was conducted comparing 1.8g of effervescent NAC per day (n=47) with placebo (n=47) as an aide to smoking cessation. Both study arms received adjunctive online support through the QuitCoach program. Participants reported smoking at each timepoint (baseline and weeks 8, 16 & 42), which was confirmed through salivary cotinine and exhaled carbon monoxide testing. Primary and secondary analyses were undertaken using a modified intent-to-treat basis, including all participants with at least one valid post baseline outcome, regardless of treatment received or their withdrawal from the study. There was no significant difference in smoking outcomes between intervention groups among the 24 participants that competed follow-up. There were no significant differences in age, gender, or body mass index (BMI) between the groups lost to follow-up or recorded at follow-up. This study found no evidence to support NAC as a therapy for smoking cessation. The negative outcome could be the result of lack of treatment efficacy, or alternatively, small sample size, participant retention difficulties, dose, or duration of follow-up. Trial Registration: Australian New Zealand Clinical Trials registry (ANZCTR), ACTRN12617001478303. Registered on 19 October 2017.

Baseline serum amino acid levels predict treatment response to augmentation with N-acetylcysteine (NAC) in a bipolar disorder randomised trial

N-acetylcysteine (NAC) acts on glutamatergic and redox systems, two systems implicated in the pathophysiology of bipolar disorder (BD). This has led to the investigation of NAC as a potential candidate for the treatment of BD. The aim of this study was to investigate metabolomic markers to identify predictors of NAC response in a cohort of BD participants. This study is a secondary analysis of a 16-week, multi-site, randomized, double-blinded, parallel-group, placebo-controlled trial in BD participants with a current acute depressive episode. This study included trial participants who received either NAC 2000 mg/day, or placebo. Participants (NAC: n = 31, placebo: n = 29) were assessed at baseline and week 16 using the Montgomery Åsberg Depression Rating Scale (MADRS) and were dichotomised into "responders" (MADRS at week 16 < 50% of MADRS at baseline) and "non-responders" (MADRS at week 16 > 50% at baseline). Untargeted gas chromatography-mass spectrometry analysis was performed to analyse baseline levels of 68 serum metabolites. Of the nine metabolites that differentiated placebo and NAC groups, five were amino acids with lower levels in the NAC responder group compared with the NAC non-responders. Further analysis generated a predictive model of MADRS improvement including glycine, norleucine, threonine, proline, phenylalanine, tyrosine, glutamic acid, lysine and leucine (R² = 0.853; adjusted R² = 0.733). This prediction model predicted 85% of the variance in MADRS outcome after adjunctive treatment with NAC. BD participants with lower serum levels of free amino acids at baseline may be more likely to respond to adjunctive treatment with NAC.

Biological Mechanism(s) Underpinning the Association between Antipsychotic Drugs and Weight Gain

Weight gain and consequent metabolic alterations are common side-effects of many antipsychotic drugs. Interestingly, several studies have suggested that improvement in symptoms and adverse metabolic effects are correlated. We used next generation sequencing data from NT-2 (human neuronal) cells treated with aripiprazole, amisulpride, risperidone, quetiapine, clozapine, or vehicle control, and compared with the Pillinger P-score (ranked from 0 to 1, indicating greater increase in weight gain and related metabolic parameters) to identify the genes most associated with the drugs' propensity to cause weight gain. The top 500 genes ranked for their correlation with the drugs' propensity to cause weight gain were subjected to pathway analysis using DAVID (NIH). We further investigated transcription factors (TFs) that are more likely to regulate the genes involved in these processes using the prediction tool of key TFs from TRRUST. The results suggest an enrichment for genes involved in lipid biosynthesis and metabolism, which are of interest for mechanisms underpinning weight-gain. The list of genes involved in the lipid pathways that correlated with weight gain was enriched for genes transcriptionally regulated by SREBF1 and SREBF2. Furthermore, quetiapine significantly increased the expression of SREBF1 and SREBF2 in NT-2 cells. Our results suggest that the effects of these antipsychotic drugs on lipid metabolism may be mediated, at least in part, via regulation of SREBF1/SREBF2 expression, with evidence of a direct effect of quetiapine on the expression of SREBF1/2. The effects of antipsychotic drugs on lipid metabolism may influence white matter structure (therapeutic effect) and the risk of weight gain, lipid disturbances, and, consequently, metabolic syndrome (adverse effects). Understanding the different molecular effects of these drugs could inform a personalized medicine approach in treating patients with schizophrenia.

Polyphenols as adjunctive treatments in psychiatric and neurodegenerative disorders: Efficacy, mechanisms of action, and factors influencing inter-individual response

The pathophysiology of psychiatric and neurodegenerative disorders is complex and multifactorial. Polyphenols possess a range of potentially beneficial mechanisms of action that relate to the implicated pathways in psychiatric and neurodegenerative disorders. The aim of this review is to highlight the emerging clinical trial and preclinical efficacy data regarding the role of polyphenols in mental and brain health, elucidate novel mechanisms of action including the gut microbiome and gene expression, and discuss the factors that may be responsible for the mixed clinical results; namely, the role of interindividual differences in treatment response and the potentially pro-oxidant effects of some polyphenols. Further clarification as part of larger, well conducted randomized controlled trials that incorporate precision medicine methods are required to inform clinical efficacy and optimal dosing regimens.

Total Antioxidant Capacity and Frailty in Older Men

Frailty, a clinical syndrome characterized by multisystem dysregulation, has been associated with high levels of oxidative stress. We investigated the association between serum total antioxidant capacity (TAC) and frailty in older men. This cross-sectional study included 581 men (age 60–90 years) enrolled in the Geelong Osteoporosis Study. Frailty comprised at least three of unintentional weight loss, exhaustion, low physical activity, slowness, and weakness. Serum TAC was measured by quantitative colorimetric determination and expressed as uric acid equivalents (mM). Relationships between TAC (in SD units) and frailty were explored using multivariable logistic regression models. Sociodemographic, anthropometric, and lifestyle variables were tested as potential confounders and effect modifiers. A sensitivity analysis excluded participants (n = 145) in the upper quartile of TAC, who were likely to have hyperuricemia. Fifty (8.6%) men were frail. There was evidence that higher TAC levels were associated with increased likelihood of frailty (OR 1.34, 95% confidence interval [CI; 0.99, 1.80]), and this was attenuated after adjustment for age and body mass index (BMI; OR 1.26, 95% CI [0.93,1.71]). No effect modifiers or other confounders were identified. The sensitivity analysis revealed a positive association between TAC and frailty, before and after accounting for age and BMI (adjusted OR 1.79, 95% CI [1.01, 3.17] p = .038). These results suggest a positive association between TAC levels and frailty, supporting the hypothesis that this biomarker could be useful in identifying individuals at risk of frailty. We speculate that a milieu of heightened oxidative stress in frailty may elevate the oxidative stress regulatory set point, raising antioxidant activity. This warrants further investigation.

The cytokine storms of COVID-19, H1N1 influenza, CRS and MAS compared. Can one sized treatment fit all?

An analysis of published data appertaining to the cytokine storms of COVID-19, H1N1 influenza, cytokine release syndrome (CRS), and macrophage activation syndrome (MAS) reveals many common immunological and biochemical abnormalities. These include evidence of a hyperactive coagulation system with elevated D-dimer and ferritin levels, disseminated intravascular coagulopathy (DIC) and microthrombi coupled with an activated and highly permeable vascular endothelium. Common immune abnormalities include progressive hypercytokinemia with elevated levels of TNF-α, interleukin (IL)-6, and IL-1β, proinflammatory chemokines, activated macrophages and increased levels of nuclear factor kappa beta (NFκB). Inflammasome activation and release of damage associated molecular patterns (DAMPs) is common to COVID-19, H1N1, and MAS but does not appear to be a feature of CRS. Elevated levels of IL-18 are detected in patients with COVID-19 and MAS but have not been reported in patients with H1N1 influenza and CRS. Elevated interferon-γ is common to H1N1, MAS, and CRS but levels of this molecule appear to be depressed in patients with COVID-19. CD4+ T, CD8+ and NK lymphocytes are involved in the pathophysiology of CRS, MAS, and possibly H1N1 but are reduced in number and dysfunctional in COVID-19. Additional elements underpinning the pathophysiology of cytokine storms include Inflammasome activity and DAMPs. Treatment with anakinra may theoretically offer an avenue to positively manipulate the range of biochemical and immune abnormalities reported in COVID-19 and thought to underpin the pathophysiology of cytokine storms beyond those manipulated via the use of, canakinumab, Jak inhibitors or tocilizumab. Thus, despite the relative success of tocilizumab in reducing mortality in COVID-19 patients already on dexamethasone and promising results with Baricitinib, the combination of anakinra in combination with dexamethasone offers the theoretical prospect of further improvements in patient survival. However, there is currently an absence of trial of evidence in favour or contravening this proposition. Accordingly, a large well powered blinded prospective randomised controlled trial (RCT) to test this hypothesis is recommended.

Transcriptional Modulation of the Hippo Signaling Pathway by Drugs Used to Treat Bipolar Disorder and Schizophrenia

Recent reports suggest a link between positive regulation of the Hippo pathway with bipolar disorder (BD), and the Hippo pathway is known to interact with multiple other signaling pathways previously associated with BD and other psychiatric disorders. In this study, neuronal-like NT2 cells were treated with amisulpride (10 µM), aripiprazole (0.1 µM), clozapine (10 µM), lamotrigine (50 µM), lithium (2.5 mM), quetiapine (50 µM), risperidone (0.1 µM), valproate (0.5 mM), or vehicle control for 24 h. Genome-wide mRNA expression was quantified and analyzed using gene set enrichment analysis (GSEA), with genes belonging to Hippo, Wnt, Notch, TGF- β, and Hedgehog retrieved from the KEGG database. Five of the eight drugs downregulated the genes of the Hippo pathway and modulated several genes involved in the interacting pathways. We speculate that the regulation of these genes, especially by aripiprazole, clozapine, and quetiapine, results in a reduction of MAPK and NFκB pro-inflammatory signaling through modulation of Hippo, Wnt, and TGF-β pathways. We also employed connectivity map analysis to identify compounds that act on these pathways in a similar manner to the known psychiatric drugs. Thirty-six compounds were identified. The presence of antidepressants and antipsychotics validates our approach and reveals possible new targets for drug repurposing.

The endocannabinoidome in neuropsychiatry: Opportunities and potential risks

The endocannabinoid system (ECS) comprises two cognate endocannabinoid receptors referred to as CB1R and CB2R_. ECS dysregulation is apparent in neurodegenerative/neuro-psychiatric disorders including but not limited to schizophrenia, major depressive disorder and potentially bipolar disorder. The aim of this paper is to review mechanisms whereby both receptors may interact with neuro-immune and neuro-oxidative pathways, which play a pathophysiological role in these disorders. CB1R is located in the presynaptic terminals of GABAergic, glutamatergic, cholinergic, noradrenergic and serotonergic neurons where it regulates the retrograde suppression of neurotransmission. CB1R plays a key role in long-term depression, and, to a lesser extent, long-term potentiation, thereby modulating synaptic transmission and mediating learning and memory. Optimal CB1R activity plays an essential neuroprotective role by providing a defense against the development of glutamate-mediated excitotoxicity, which is achieved, at least in part, by impeding AMPA-mediated increase in intracellular calcium overload and oxidative stress. Moreover, CB1R activity enables optimal neuron-glial communication and the function of the neurovascular unit. CB2R receptors are detected in peripheral immune cells and also in central nervous system regions including the striatum, basal ganglia, frontal cortex, hippocampus, amygdala as well as the ventral tegmental area. CB2R upregulation inhibits the presynaptic release of glutamate in several brain regions. CB2R activation also decreases neuroinflammation partly by mediating the transition from a predominantly neurotoxic "M1" microglial phenotype to a more neuroprotective "M2" phenotype. CB1R and CB2R are thus novel drug targets for the treatment of neuro-immune and neuro-oxidative disorders including schizophrenia and affective disorders.

Association between serum interleukin-6 and frailty in older men: cross-sectional data

PURPOSE

To investigate the association between serum interleukin-6 (IL-6) and frailty.

METHODS

Participants were 581 men aged 60-90 yr (median (IQR): 74 yr (67-83 yr)) from the Geelong Osteoporosis Study. Tallies of ≥ 3, 1-2 and 0 for weight loss/exhaustion/physical-inactivity/slowness/weakness indicated frailty, pre-frailty and robustness, respectively. Anthropometry, lower-limb muscle strength and physical performance were measured and health behaviours self-reported. Serum IL-6 was measured using an enzyme-linked immunosorbent assay and log-transformed (ln-IL-6). Total antioxidant capacity (TAC) was also measured using quantitative colorimetric determination. Multivariable ordinal logistic regression models tested associations between ln-IL-6 and frailty while considering age, anthropometry, comorbidities, TAC, medications that affect inflammatory processes, lifestyle and socioeconomic status.

RESULTS

There were 49(8.4%) frail and 315(54.2%) pre-fail men. A relationship was evident between ln-IL-6 and frailty before and after accounting for age (adjusted OR = 1.24, 95%CI 1.01-1.53). Adjusting for medications attenuated the association (OR = 1.20, 95%CI 0.98-1.48). No other confounders were identified.

CONCLUSION

These data suggest that IL-6 is positively associated with frailty in men, partly explained by advancing age and medications known to affect inflammation.

Systemic inflammation and grey matter volume in schizophrenia and bipolar disorder: Moderation by childhood trauma severity

BACKGROUND

Elevated levels of systemic inflammation are consistently reported in both schizophrenia (SZ) and bipolar-I disorder (BD), and are associated with childhood trauma exposure. We tested whether childhood trauma exposure moderates associations between systemic inflammation and brain morphology in people with these diagnoses.

METHODS

Participants were 55 SZ cases, 52 BD cases and 59 healthy controls (HC) who underwent magnetic resonance imaging. Systemic inflammation was measured using a composite z-score derived from serum concentrations of interleukin 6, tumor necrosis factor alpha and C-reactive protein. Indices of grey matter volume covariation (GMC) were derived from independent component analysis. Childhood trauma was measured using the Childhood Trauma Questionnaire (CTQ Total score).

RESULTS

A series of moderated moderation analyses indicated that increased systemic inflammation were associated with increased GMC in the striatum and cerebellum among all participants. Severity of childhood trauma exposure moderated the relationship between systemic inflammation and GMC in one component, differently among the groups. Specifically, decreased GMC in the PCC/precuneus, parietal lobule and postcentral gyrus, and increased GMC in the left middle temporal gyrus was associated with increased systemic inflammation in HC individuals exposed to high (but not low or average) levels of trauma and in SZ cases exposed to low (but not average or high) levels of trauma, but not in BD cases.

CONCLUSIONS

Increased systemic inflammation is associated with grey matter changes in people with psychosis, and these relationships may be partially and differentially moderated by childhood trauma exposure according to diagnosis.

The role of high-density lipoprotein cholesterol, apolipoprotein A and paraoxonase-1 in the pathophysiology of neuroprogressive disorders

Lowered high-density lipoprotein (HDL) cholesterol has been reported in major depressive disorder, bipolar disorder, first episode of psychosis, and schizophrenia. HDL, its major apolipoprotein component, ApoA1, and the antioxidant enzyme paraoxonase (PON)1 (which is normally bound to ApoA1) all have anti-atherogenic, antioxidant, anti-inflammatory, and immunomodulatory roles, which are discussed in this paper. The paper details the pathways mediating the anti-inflammatory effects of HDL, ApoA1 and PON1 and describes the mechanisms leading to compromised HDL and PON1 levels and function in an environment of chronic inflammation. The molecular mechanisms by which changes in HDL, ApoA1 and PON1 might contribute to the pathophysiology of the neuroprogressive disorders are explained. Moreover, the anti-inflammatory actions of ApoM-mediated sphingosine 1-phosphate (S1P) signalling are reviewed as well as the deleterious effects of chronic inflammation and oxidative stress on ApoM/S1P signalling. Finally, therapeutic interventions specifically aimed at improving the levels and function of HDL and PON1 while reducing levels of inflammation and oxidative stress are considered. These include the so-called Mediterranean diet, extra virgin olive oil, polyphenols, flavonoids, isoflavones, pomegranate juice, melatonin and the Mediterranean diet combined with the ketogenic diet.

Effects of psychoactive drugs on cellular bioenergetic pathways

OBJECTIVES

To investigate the actions of lithium, valproate, lamotrigine and quetiapine on bioenergetic pathways in cultured NT2-N neuronal-like cells and C8-B4 microglial cells.

METHODS

NT2-N and C8-B4 cells were cultured and treated with lithium (2.5 mM), valproate (0.5 mM), quetiapine (0.05 mM) or lamotrigine (0.05 mM) for 24 hours. Gene expression and the mitochondrial bioenergetic profile were measured in both cell lines.

RESULTS

In NT2-N cells, valproate increased oxidative phosphorylation (OXPHOS) gene expression, mitochondrial uncoupling and maximal respiratory capacity, while quetiapine decreased OXPHOS gene expression and respiration linked to ATP turnover, as well as decreasing the expression of genes in the citric acid cycle. Lamotrigine decreased OXPHOS gene expression but had no effect on respiration, while lithium reduced the expression of genes in the citric acid cycle. In C8-B4 cells, valproate and lithium increased OXPHOS gene expression, and valproate increased basal respiratory rate and maximal and spare respiratory capacities. In contrast, quetiapine significantly reduced basal respiratory rate and maximal and spare respiratory capacities.

CONCLUSIONS

Overall our data suggest that some drugs used to treat neuropsychiatric and affective disorders have actions on a range of cellular bioenergetic processes, which could impact their effects in patients.

Preventing the development of severe COVID-19 by modifying immunothrombosis

BACKGROUND

COVID-19-associated acute respiratory distress syndrome (ARDS) is associated with significant morbidity and high levels of mortality. This paper describes the processes involved in the pathophysiology of COVID-19 from the initial infection and subsequent destruction of type II alveolar epithelial cells by SARS-CoV-2 and culminating in the development of ARDS.

MAIN BODY

The activation of alveolar cells and alveolar macrophages leads to the release of large quantities of proinflammatory cytokines and chemokines and their translocation into the pulmonary vasculature. The presence of these inflammatory mediators in the vascular compartment leads to the activation of vascular endothelial cells platelets and neutrophils and the subsequent formation of platelet neutrophil complexes. These complexes in concert with activated endothelial cells interact to create a state of immunothrombosis. The consequence of immunothrombosis include hypercoagulation, accelerating inflammation, fibrin deposition, migration of neutrophil extracellular traps (NETs) producing neutrophils into the alveolar apace, activation of the NLRP3 inflammazome, increased alveolar macrophage destruction and massive tissue damage by pyroptosis and necroptosis Therapeutic combinations aimed at ameliorating immunothrombosis and preventing the development of severe COVID-19 are discussed in detail.

The use of a gene expression signature and connectivity map to repurpose drugs for bipolar disorder

To create a gene expression signature (GES) to represent the biological effects of a combination of known drugs for bipolar disorder (BD) on cultured human neuronal cells (NT2-N) and rat brains, which also has evidence of differential expression in individuals with BD. To use the GES to identify new drugs for BD using Connectivity Map (CMap).Methods: NT2-N (n = 20) cells and rats (n = 8) were treated with a BD drug combination (lithium, valproate, quetiapine and lamotrigine) or vehicle for 24 and 6 h, respectively. Following next-generation sequencing, the differential expression of genes was assessed using edgeR in R. The derived GES was compared to differentially expressed genes in post-mortem brains of individuals with BD. The GES was then used in CMap analysis to identify similarly acting drugs.Results: A total of 88 genes showed evidence of differential expression in response to the drug combination in both models, and therefore comprised the GES. Six of these genes showed evidence of differential expression in post-mortem brains of individuals with BD. CMap analysis identified 10 compounds (camptothecin, chlorambucil, flupenthixol, valdecoxib, rescinnamine, GW-8510, cinnarizine, lomustine, mifepristone and nimesulide) acting similarly to the BD drug combination.Conclusions: This study shows that GES and CMap can be used as tools to repurpose drugs for BD.

Can endolysosomal deacidification and inhibition of autophagy prevent severe COVID-19?

The possibility is examined that immunomodulatory pharmacotherapy may be clinically useful in managing the pandemic coronavirus disease 2019 (COVID-19), known to result from infection by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a positive-sense single-stranded RNA virus. The dominant route of cell entry of the coronavirus is via phagocytosis, with ensconcement in endosomes thereafter proceeding via the endosomal pathway, involving transfer from early (EEs) to late endosomes (LEs) and ultimately into lysosomes via endolysosomal fusion. EE to LE transportation is a rate-limiting step for coronaviruses. Hence inhibition or dysregulation of endosomal trafficking could potentially inhibit SARS-CoV-2 replication. Furthermore, the acidic luminal pH of the endolysosomal system is critical for the activity of numerous pH-sensitive hydrolytic enzymes. Golgi sub-compartments and Golgi-derived secretory vesicles also depend on being mildly acidic for optimal function and structure. Activation of endosomal toll-like receptors by viral RNA can upregulate inflammatory mediators and contribute to a systemic inflammatory cytokine storm, associated with a worsened clinical outcome in COVID-19. Such endosomal toll-like receptors could be inhibited by the use of pharmacological agents which increase endosomal pH, thereby reducing the activity of acid-dependent endosomal proteases required for their activity and/or assembly, leading to suppression of antigen-presenting cell activity, decreased autoantibody secretion, decreased nuclear factor-kappa B activity and decreased pro-inflammatory cytokine production. It is also noteworthy that SARS-CoV-2 inhibits autophagy, predisposing infected cells to apoptosis. It is therefore also suggested that further pharmacological inhibition of autophagy might encourage the apoptotic clearance of SARS-CoV-2-infected cells.

Transcriptional Effects of Psychoactive Drugs on Genes Involved in Neurogenesis

Although neurogenesis is affected in several psychiatric diseases, the effects and mechanisms of action of psychoactive drugs on neurogenesis remain unknown and/or controversial. This study aims to evaluate the effects of psychoactive drugs on the expression of genes involved in neurogenesis. Neuronal-like cells (NT2-N) were treated with amisulpride (10 µM), aripiprazole (0.1 µM), clozapine (10 µM), lamotrigine (50 µM), lithium (2.5 mM), quetiapine (50 µM), risperidone (0.1 µM), or valproate (0.5 mM) for 24 h. Genome wide mRNA expression was quantified and analysed using gene set enrichment analysis, with the neurogenesis gene set retrieved from the Gene Ontology database and the Mammalian Adult Neurogenesis Gene Ontology (MANGO) database. Transcription factors that are more likely to regulate these genes were investigated to better understand the biological processes driving neurogenesis. Targeted metabolomics were performed using gas chromatography-mass spectrometry. Six of the eight drugs decreased the expression of genes involved in neurogenesis in both databases. This suggests that acute treatment with these psychoactive drugs negatively regulates the expression of genes involved in neurogenesis in vitro. SOX2 and three of its target genes (CCND1, BMP4, and DKK1) were also decreased after treatment with quetiapine. This can, at least in part, explain the mechanisms by which these drugs decrease neurogenesis at a transcriptional level in vitro. These results were supported by the finding of increased metabolite markers of mature neurons following treatment with most of the drugs tested, suggesting increased proportions of mature relative to immature neurons consistent with reduced neurogenesis.

Trace Amine-Associated Receptor 1 (TAAR1): A new drug target for psychiatry?

There are nine subfamilies of TAARs. They are predominantly intracellular, located in the central nervous system and peripherally. They have a role in homeostasis and rheostasis, and also in olfaction. They demonstrate significant cross-talk with the monoamine system and are involved in the regulation of cAMP signalling and K⁺ channels. There is evidence to suggest that TAAR1 may be a promising therapeutic target for the treatment of schizophrenia, psychosis in Parkinson's disease, substance use disorders, and the metabolic syndrome and obesity. TAAR1 expression may also be a prognostic biomarker for cancers. A number of TAAR modulators have been identified, including endogenous ligands and new chemical entities. Some of these agents have shown efficacy in animal models of addiction behaviours, depression and anxiety. Only one agent, SEP-363856, has progressed to randomised clinical trials in humans; however further, larger studies with SEP-363856 are required to clarify its suitability as a new treatment for schizophrenia spectrum disorders. SEP-363856 is an agonist of TAAR1 and 5HT_1A and it is not clear to what extent its efficacy can be attributed to TAAR1 rather than to other drug targets. However, current research suggests that TAAR1 has an important role in human physiology and pathophysiology. TAAR1 modulators may become an important new drug class for the management of a wide array of mental disorders in the future.

The pathophysiology of SARS-CoV-2: A suggested model and therapeutic approach

In this paper, a model is proposed of the pathophysiological processes of COVID-19 starting from the infection of human type II alveolar epithelial cells (pneumocytes) by SARS-CoV-2 and culminating in the development of ARDS. The innate immune response to infection of type II alveolar epithelial cells leads both to their death by apoptosis and pyroptosis and to alveolar macrophage activation. Activated macrophages secrete proinflammatory cytokines and chemokines and tend to polarise into the inflammatory M1 phenotype. These changes are associated with activation of vascular endothelial cells and thence the recruitment of highly toxic neutrophils and inflammatory activated platelets into the alveolar space. Activated vascular endothelial cells become a source of proinflammatory cytokines and reactive oxygen species (ROS) and contribute to the development of coagulopathy, systemic sepsis, a cytokine storm and ARDS. Pulmonary activated platelets are also an important source of proinflammatory cytokines and ROS, as well as exacerbating pulmonary neutrophil-mediated inflammatory responses and contributing to systemic sepsis by binding to neutrophils to form platelet-neutrophil complexes (PNCs). PNC formation increases neutrophil recruitment, activation priming and extraversion of these immune cells into inflamed pulmonary tissue, thereby contributing to ARDS. Sequestered PNCs cause the development of a procoagulant and proinflammatory environment. The contribution to ARDS of increased extracellular histone levels, circulating mitochondrial DNA, the chromatin protein HMGB1, decreased neutrophil apoptosis, impaired macrophage efferocytosis, the cytokine storm, the toll-like receptor radical cycle, pyroptosis, necroinflammation, lymphopenia and a high Th17 to regulatory T lymphocyte ratio are detailed.

Minocycline for the treatment of mental health and neurological conditions: study protocol of a systematic review and meta-analysis

INTRODUCTION

Due to the anti-inflammatory, antioxidant and anti-apoptotic properties of minocycline, clinical trials have evaluated the potential of this drug to treat several psychiatric and neurological disorders, including major depressive disorder, schizophrenia, bipolar disorder, stroke and amyotrophic lateral sclerosis. This protocol proposes a systematic review (and potential meta-analysis) that aims to identify and critically evaluate randomised controlled trials of minocycline for treating psychiatric and neurological disorders.

METHODS AND ANALYSIS

PubMed, Embase, Cochrane Central Register of Controlled Clinical Trials, PsycINFO and Cumulative Index to Nursing and Allied Health Literature (CINAHL) will be used to identify randomised controlled trials that used minocycline to treat psychiatric and neurological disorders. Double-blind, randomised, controlled, clinical trials of participants aged 18 years or older and written in English will be included in the review. Data will be extracted by two independent reviewers. Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines will be followed and the Cochrane Collaboration's 'Risk of Bias' tool will be used to assess the risk of bias in all studies included in the systematic review. The Grading of Recommendations, Assessment, Development and Evaluation system will be used to access the overall quality of the level of evidence of the studies. If sufficient evidence is identified, a meta-analysis will be conducted using the standardised mean difference approach and reported with 95% CIs. Heterogeneity of evidence will be evaluated using the I² model.

ETHICS AND DISSEMINATION

This systematic review will evaluate only published data; therefore, ethical approval is not required. The systematic review will be published in a peer-reviewed journal and presented at relevant research conferences.

TRIAL REGISTRATION NUMBER

CRD42020153292.

Drugs used to treat bipolar disorder act via microRNAs to regulate expression of genes involved in neurite outgrowth

BACKGROUND

The drugs commonly used to treat bipolar disorder have limited efficacy and drug discovery is hampered by the paucity of knowledge of the pathophysiology of this disease. This study aims to explore the role of microRNAs in bipolar disorder and understand the molecular mechanisms of action of commonly used bipolar disorder drugs.

METHODS

The transcriptional effects of bipolar disorder drug combination (lithium, valproate, lamotrigine and quetiapine) in cultured human neuronal cells were studied using next generation sequencing. Differential expression of genes (n=20) and microRNAs (n=6) was assessed and the differentially expressed microRNAs were confirmed with TaqMan MicroRNA Assays. The expression of the differentially expressed microRNAs were inhibited to determine bipolar disorder drug effects on their target genes (n=8). Independent samples t-test was used for normally distributed data and Kruskal-Wallis/Mann-Whitney U test was used for data not distributed normally. Significance levels were set at p<0.05.

RESULTS

We found that bipolar disorder drugs tended to increase the expression of miR-128 and miR-378 (p<0.05). Putative target genes of these microRNAs targeted pathways including those identified as "neuron projection development" and "axonogenesis". Many of the target genes are inhibitors of neurite outgrowth and neurogenesis and were downregulated following bipolar disorder drug combination treatment (all p<0.05). The bipolar disorder drug combination tended to decrease the expression of the target genes (NOVA1, GRIN3A, and VIM), however this effect could be reversed by the application of microRNA inhibitors.

CONCLUSIONS

We conclude that at a transcriptional level, bipolar disorder drugs affect several genes in concert that would increase neurite outgrowth and neurogenesis and hence neural plasticity, and that this effect is mediated (at least in part) by modulation of the expression of these two key microRNAs.

The compensatory antioxidant response system with a focus on neuroprogressive disorders

Major antioxidant responses to increased levels of inflammatory, oxidative and nitrosative stress (ONS) are detailed. In response to increasing levels of nitric oxide, S-nitrosylation of cysteine thiol groups leads to post-transcriptional modification of many cellular proteins and thereby regulates their activity and allows cellular adaptation to increased levels of ONS. S-nitrosylation inhibits the function of nuclear factor kappa-light-chain-enhancer of activated B cells, toll-like receptor-mediated signalling and the activity of several mitogen-activated protein kinases, while activating nuclear translocation of nuclear factor (erythroid-derived 2)-like 2 (Nrf2 or NFE2L2); in turn, the redox-regulated activation of Nrf2 leads to increased levels and/or activity of key enzymes and transporter systems involved in the glutathione system. The Nrf2/Kelch-like ECH-associated protein-1 axis is associated with upregulation of NAD(P)H:quinone oxidoreductase 1, which in turn has anti-inflammatory effects. Increased Nrf2 transcriptional activity also leads to activation of haem oxygenase-1, which is associated with upregulation of bilirubin, biliverdin and biliverdin reductase as well as increased carbon monoxide signalling, anti-inflammatory and antioxidant activity. Associated transcriptional responses, which may be mediated by retrograde signalling owing to elevated hydrogen peroxide, include the unfolded protein response (UPR), mitohormesis and the mitochondrial UPR; the UPR also results from increasing levels of mitochondrial and cytosolic reactive oxygen species and reactive nitrogen species leading to nitrosylation, glutathionylation, oxidation and nitration of crucial cysteine and tyrosine causing protein misfolding and the development of endoplasmic reticulum stress. It is shown how these mechanisms co-operate in forming a co-ordinated rapid and prolonged compensatory antioxidant response system.

Drugs used in the treatment of bipolar disorder and their effects on cholesterol biosynthesis - A possible therapeutic mechanism

Objectives: To understand the therapeutic mechanisms of bipolar disorder (BD) drugs at molecular and cellular levels.Methods: Next generation sequencing was used to determine the transcriptional effects of a combination of four commonly prescribed BD drugs (lithium, valproate, lamotrigine and quetiapine) or vehicle (0.2% DMSO) in NT2-N (human neuronal) cells and rats. Differential expression of genes and pathway analysis were performed using edgeR in R and Gene Set Enrichment Analysis software respectively. Free cholesterol levels and neurite outgrowth were quantified in NT2-N cells following combination and individual BD drug treatments.Results: Pathway analysis showed up-regulation of many elements of the cholesterol biosynthesis pathway in NT2-N cells and oxidative phosphorylation in rat brains. Intracellular cholesterol transport genes were upregulated (NPC1, NPC2 and APOE), while the cholesterol efflux gene (ABCA1) was downregulated. BD drug combination tended to increase intracellular cholesterol levels and neurite outgrowth, but these effects were not seen for the drugs when used individually.Conclusions: These data suggest that BD drug combination is increasing cholesterol biosynthesis and the newly synthesised cholesterol is being utilised within the cells, possibly for synthesis of new membranes to facilitate neurite outgrowth. This mechanism possibly underpins clinical efficacy in individuals with BD treated with polypharmacy.

Association between childhood trauma exposure and pro-inflammatory cytokines in schizophrenia and bipolar-I disorder

BACKGROUND

Elevated levels of pro-inflammatory cytokines are consistently reported in schizophrenia (SZ) and bipolar-I disorder (BD), as well as among individuals who have been exposed to childhood trauma. However, higher levels of inflammatory markers in these disorders are yet to be investigated with respect to levels of exposure to different types of childhood trauma.

METHODS

Participants were 68 cases with a diagnosis of schizophrenia/schizoaffective disorder (SZ), 69 cases with a diagnosis of psychotic BD and 72 healthy controls (HC). Serum levels of interleukin 6 (IL-6), tumour necrosis factor-α (TNF-α) and C-reactive protein (CRP) were quantified, and childhood trauma exposure was assessed with the Childhood Trauma Questionnaire.

RESULTS

The SZ group had significantly higher levels of IL-6, TNF-α and CRP when compared with the HC group (all p < 0.05, d = 0.41-0.63), as well as higher levels of TNF-α when compared with the BD group (p = 0.014, d = 0.50); there were no differences between the BD and HC groups for any markers. Exposure to sexual abuse was positively associated (standardised β = 0.326, t = 2.459, p = 0.018) with levels of CRP in the SZ group, but there were no significant associations between any form of trauma exposure and cytokine levels in the HC or BD groups.

CONCLUSIONS

These results contribute to the evidence for a chronic state of inflammation in SZ but not BD cases. Differential associations between trauma exposure and levels of pro-inflammatory cytokines across the diagnostic categories suggest that trauma may impact biological (stress and immune) systems differently in these patient groups.

ENACT: a protocol for a randomised placebo-controlled trial investigating the efficacy and mechanisms of action of adjunctive N-acetylcysteine for first-episode psychosis

Background

First-episode psychosis (FEP) may lead to a progressive, potentially disabling and lifelong chronic illness; however, evidence suggests that the illness course can be improved if appropriate treatments are given at the early stages. Nonetheless, the efficacy of antipsychotic medications is suboptimal, particularly for negative and cognitive symptoms, and more efficacious and benign treatments are needed. Previous studies have shown that the antioxidant amino acid N-acetylcysteine (NAC) reduces negative symptoms and improves functioning in chronic schizophrenia and bipolar disorder. Research is scarce as to whether NAC is beneficial earlier in the course of illness. The primary aim of this study is to determine the efficacy of treatment with adjunctive NAC (2 g/day for 26 weeks) compared with placebo to improve psychiatric symptoms in young people experiencing FEP. Secondary aims are to explore the neurobiological mechanisms underpinning NAC and how they relate to various clinical and functional outcomes at 26- and 52-week follow-ups.

Methods/design

ENACT is a 26-week, randomised controlled trial of adjunctive NAC versus placebo, with a 26-week non-treatment follow-up period, for FEP. We will be recruiting 162 young people aged 15–25 years who have recently presented to, and are being treated at, the Early Psychosis Prevention and Intervention Centre, Melbourne, Australia. The primary outcome is the Total Score on the Positive and Negative Syndrome Scale which will be administered at baseline, and weeks 4, 8, 12, 26 (primary endpoint), and 52 (end of study). Secondary outcomes include: symptomatology, functioning, quality of life, neurocognition, blood-derived measures of: inflammation, oxidative and nitrosative stress, and magnetic resonance spectroscopy measures of glutathione concentration.

Discussion

Targeted drug development for FEP to date has generally not involved the exploration of neuroprotective agents. This study has the potential to offer a new, safe, and efficacious treatment for people with FEP, leading to better treatment outcomes. Additionally, the neuroprotective dimension of this study may lead to a better long-term prognosis for people with FEP. It has the potential to uncover a novel treatment that targets the neurobiological mechanisms of FEP and, if successful, will be a major advance for psychiatry.

Trial registration

Australian New Zealand Clinical Trials Registry, ID: ACTRN12618000413224. Registered on 21 March 2018.

Shared pathways for neuroprogression and somatoprogression in neuropsychiatric disorders

Activated immune-inflammatory, oxidative and nitrosative stress (IO&NS) pathways and consequent mitochondrial aberrations are involved in the pathophysiology of psychiatric disorders including major depression, bipolar disorder and schizophrenia. They offer independent and shared contributions to pathways underpinning medical comorbidities including insulin resistance, metabolic syndrome, obesity and cardiovascular disease - herein conceptualized as somatoprogression. This narrative review of human studies aims to summarize relationships between IO&NS pathways, neuroprogression and somatoprogression. Activated IO&NS pathways, implicated in the neuroprogression of psychiatric disorders, affect the pathogenesis of comorbidities including insulin resistance, dyslipidaemia, obesity and hypertension, and by inference, metabolic syndrome. These conditions activate IO&NS pathways, exacerbating neuroprogression in psychiatric disorders. The processes whereby proinflammatory cytokines, nitrosative and endoplasmic reticulum stress, NADPH oxidase isoforms, PPARγ inactivation, SIRT1 deficiency and intracellular signalling pathways impact lipid metabolism and storage are considered. Through associations between body mass index, chronic neuroinflammation and FTO expression, activation of IO&NS pathways arising from somatoprogression may contribute to neuroprogression. Early evidence highlights the potential of adjuvants targeting IO&NS pathways for treating somatoprogression and neuroprogression.

N-acetylcysteine for cessation of tobacco smoking: rationale and study protocol for a randomised controlled trial

Background

Tobacco smoking is a highly prevalent, addictive behaviour and a key public health priority. However available cessation therapies have low quit and high relapse rates, indicating an urgent need for more effective treatments. Predicated on promising preclinical and pilot clinical data, this paper presents a rationale and protocol for the trial of N-acetylcysteine (NAC) as a novel anti-craving smoking cessation aid.

Methods

Current smokers (n = 120) of at least 10 cigarettes a day are recruited through online advertisements, print publications and dissemination of flyers. Participants are randomised on a 1:1 ratio to receive either 16-week treatment of 1.8 g/day of NAC or placebo with all participants receiving quit support from the online QuitCoach tool. Participants are attending visits at baseline, 8 and 16 weeks with a 42-week post-discontinuation follow-up. The primary outcome measure is sustained abstinence at six months after treatment based on self-reported rating scales and confirmed by exhaled carbon monoxide and salivary cotinine levels. Secondary outcomes are timing of the first lapse and relapse, between-group cigarette consumption, withdrawal symptoms, general wellbeing and mood/anxiety symptoms. Between-group differences in adverse events and subgroup analyses for variables including gender and Diagnostic Statistics Manual 5 diagnostics will also be investigated.

Discussion

The planned trial addresses an issue of major importance to human health and, if an effect is shown, may result in substantial changes to the management of smoking and nicotine addiction with overt public health implications.

Trial registration

Australian New Zealand Clinical Trials registry (ANZCTR), ACTRN12617001478303. Registered on 19 October 2017.

Electronic supplementary material

The online version of this article (10.1186/s13063-019-3628-5) contains supplementary material, which is available to authorized users.

The Therapeutic Potential of Mangosteen Pericarp as an Adjunctive Therapy for Bipolar Disorder and Schizophrenia

New treatments are urgently needed for serious mental illnesses including bipolar disorder and schizophrenia. This review proposes that Garcinia mangostana Linn. (mangosteen) pericarp is a possible adjunctive therapeutic agent for these disorders. Research to date demonstrates that neurobiological properties of the mangosteen pericarp are well aligned with the current understanding of the pathophysiology of bipolar disorder and schizophrenia. Mangosteen pericarp has antioxidant, putative neuroprotective, anti-inflammatory, and putative mitochondrial enhancing properties, with animal studies demonstrating favorable pharmacotherapeutic benefits with respect to these disorders. This review summarizes evidence of its properties and supports the case for future studies to assess the utility of mangosteen pericarp as an adjunctive treatment option for mood and psychotic disorders.

Mechanisms Underpinning the Polypharmacy Effects of Medications in Psychiatry

BACKGROUND

Bipolar disorder is a mental health condition with progressive social and cognitive function disturbances. Most patients' treatments are based on polypharmacy, but with no biological basis and little is known of the drugs' interactions. The aim of this study was to analyze the effects of lithium, valproate, quetiapine, and lamotrigine, and the interactions between them, on markers of inflammation, bioenergetics, mitochondrial function, and oxidative stress in neuron-like cells and microglial cells.

METHODS

Neuron-like cells and lipopolysaccharide-stimulated C8-B4 cells were treated with lithium (2.5 mM), valproate (0.5 mM), quetiapine (0.05 mM), and lamotrigine (0.05 mM) individually and in all possible combinations for 24 h. Twenty cytokines were measured in the media from lipopolysaccharide-stimulated C8-B4 cells. Metabolic flux analysis was used to measure bioenergetics, and real-time PCR was used to measure the expression of mitochondrial function genes in neuron-like cells. The production of superoxide in treated cells was also assessed.

RESULTS

The results suggest major inhibitory effects on proinflammatory cytokine release as a therapeutic mechanism of these medications when used in combination. The various combinations of medications also caused overexpression of PGC1α and ATP5A1 in neuron-like cells. Quetiapine appears to have a proinflammatory effect in microglial cells, but this was reversed by the addition of lamotrigine independent of the drug combination.

CONCLUSION

Polypharmacy in bipolar disorder may have antiinflammatory effects on microglial cells as well as effects on mitochondrial biogenesis in neuronal cells.

Increased oxidative stress in foam cells obtained from hemodialysis patients

Premature atherosclerosis represents the main cause of mortality among end-stage renal disease patients (ESRD). Increased inflammation and oxidative stress are involved in initiation and progression of the atherosclerotic plaque. As foam cells are capable of producing significant amounts of inflammatory mediators and free radicals, we hypothesized that foam cells from uremic patients could produce more inflammation and oxidative stress than foam cells from normal people and be, somehow, involved in the accelerated atherosclerosis of uremia. To test this hypothesis, the levels of a few markers of inflammation and oxidative stress: Tumor necrosis factor-α, inducible nitric oxide synthase, malondialdehyde, nitric oxide by-products were measured in the supernatants of macrophage-derived foam cells cultures from 18 hemodialysis patients and 18 apparently healthy individuals controls. Malondialdehyde levels in the supernatant of cell cultures (macrophages stimulated or not with native and oxidized lipoprotein) were significantly increased in uremic patients; no statistically significant difference was found between the supernatant concentrations of nitric oxide by-products, inducible nitric oxide synthase activity, and tumor necrosis factor-α between patients and controls. Our results, obtained with human macrophages and macrophage-derived foam cells, are compatible with the theory that increased cellular oxidative stress and inflammatory activity in ESRD patients could accelerate the atherosclerotic process. The present culture protocol showed it is possible to use human mononuclear cells to evaluate the oxidative metabolism of foam cells, which are considered to be the initial step of atherosclerotic lesions.