Molecular signatures of peripheral blood mononuclear cells during chronic interferon-α treatment: relationship with depression and fatigue

Type I interferons, inflammation, and fatigue in a longitudinal RNA study of women with breast cancer

BACKGROUND

Fatigue is a common side effect of cancer and its treatment and is thought to be driven in part by activation of the proinflammatory cytokine network. However, the cellular and molecular underpinnings of cancer-related fatigue (CRF) have not been determined, nor have immune pathways beyond inflammation been carefully investigated. The goal of this study was to examine the association between CRF and activation of canonical proinflammatory gene regulation pathways and Type I interferon (IFN) signaling pathways in breast cancer patients during and after treatment.

METHODS

Women diagnosed with early-stage breast cancer (n = 181) completed assessments before and after treatment with radiation and/or chemotherapy and at 6, 12, and 18-month post-treatment follow-ups. Assessments included self-reported fatigue (Multidimensional Fatigue Symptom Inventory - Short Form) and expression of pre-specified sets of Type I IFN and pro-inflammatory immune response genes determined from mRNA sequencing of PBMCs. Mixed effect linear models examined changes in fatigue and immune gene expression over time and tested the hypothesis that fatigue would be associated with increased expression of Type I IFN and inflammatory response genes.

RESULTS

There were significant changes in fatigue and immune gene expression across the assessment period; all measures increased from pre- to post-treatment but showed diverging patterns over the follow-up, with declines in fatigue and persistent elevations in Type I IFN and proinflammatory gene expression. In mixed effect linear models, expression of Type I IFN response genes was elevated in association with fatigue across the assessment period, from pre-treatment to 18-month follow-up. In contrast, pro-inflammatory gene expression was associated with fatigue only at 6, 12, and 18-month follow-ups. Analyses controlling for changes in leukocyte subsets continued to show a significant association between fatigue and Type I IFN gene expression but reduced the time-dependent association with pro-inflammatory gene expression to non-significant.

CONCLUSIONS

Results revealed unexpected complexity in the immune underpinnings of CRF and identify a novel role for IFN signaling as a robust contributor to this symptom before, during, and after treatment. Pro-inflammatory gene expression emerged as a predictor of fatigue later in the cancer trajectory, and that effect was primarily accounted for by a concurrent increase in monocyte prevalence.

Schizophrenia Synaptic Pathology and Antipsychotic Treatment in the Framework of Oxidative and Mitochondrial Dysfunction: Translational Highlights for the Clinics and Treatment

Schizophrenia is a worldwide mental illness characterized by alterations at dopaminergic and glutamatergic synapses resulting in global dysconnectivity within and between brain networks. Impairments in inflammatory processes, mitochondrial functions, energy expenditure, and oxidative stress have been extensively associated with schizophrenia pathophysiology. Antipsychotics, the mainstay of schizophrenia pharmacological treatment and all sharing the common feature of dopamine D2 receptor occupancy, may affect antioxidant pathways as well as mitochondrial protein levels and gene expression. Here, we systematically reviewed the available evidence on antioxidants' mechanisms in antipsychotic action and the impact of first- and second-generation compounds on mitochondrial functions and oxidative stress. We further focused on clinical trials addressing the efficacy and tolerability of antioxidants as an augmentation strategy of antipsychotic treatment. EMBASE, Scopus, and Medline/PubMed databases were interrogated. The selection process was conducted in respect of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria. Several mitochondrial proteins involved in cell viability, energy metabolism, and regulation of oxidative systems were reported to be significantly modified by antipsychotic treatment with differences between first- and second-generation drugs. Finally, antioxidants may affect cognitive and psychotic symptoms in patients with schizophrenia, and although the evidence is only preliminary, the results indicate that further studies are warranted.

Canonical and Non-Canonical Antipsychotics' Dopamine-Related Mechanisms of Present and Next Generation Molecules: A Systematic Review on Translational Highlights for Treatment Response and Treatment-Resistant Schizophrenia

Schizophrenia is a severe psychiatric illness affecting almost 25 million people worldwide and is conceptualized as a disorder of synaptic plasticity and brain connectivity. Antipsychotics are the primary pharmacological treatment after more than sixty years after their introduction in therapy. Two findings hold true for all presently available antipsychotics. First, all antipsychotics occupy the dopamine D2 receptor (D2R) as an antagonist or partial agonist, even if with different affinity; second, D2R occupancy is the necessary and probably the sufficient mechanism for antipsychotic effect despite the complexity of antipsychotics' receptor profile. D2R occupancy is followed by coincident or divergent intracellular mechanisms, implying the contribution of cAMP regulation, β-arrestin recruitment, and phospholipase A activation, to quote some of the mechanisms considered canonical. However, in recent years, novel mechanisms related to dopamine function beyond or together with D2R occupancy have emerged. Among these potentially non-canonical mechanisms, the role of Na²⁺ channels at the dopamine at the presynaptic site, dopamine transporter (DAT) involvement as the main regulator of dopamine concentration at synaptic clefts, and the putative role of antipsychotics as chaperones for intracellular D2R sequestration, should be included. These mechanisms expand the fundamental role of dopamine in schizophrenia therapy and may have relevance to considering putatively new strategies for treatment-resistant schizophrenia (TRS), an extremely severe condition epidemiologically relevant and affecting almost 30% of schizophrenia patients. Here, we performed a critical evaluation of the role of antipsychotics in synaptic plasticity, focusing on their canonical and non-canonical mechanisms of action relevant to the treatment of schizophrenia and their subsequent implication for the pathophysiology and potential therapy of TRS.

Potential molecular mechanisms of chronic fatigue in long haul COVID and other viral diseases

Historically, COVID-19 emerges as one of the most devastating diseases of humankind, which creates an unmanageable health crisis worldwide. Until now, this disease costs millions of lives and continues to paralyze human civilization's economy and social growth, leaving an enduring damage that will take an exceptionally long time to repair. While a majority of infected patients survive after mild to moderate reactions after two to six weeks, a growing population of patients suffers for months with severe and prolonged symptoms of fatigue, depression, and anxiety. These patients are no less than 10% of total COVID-19 infected individuals with distinctive chronic clinical symptomatology, collectively termed post-acute sequelae of COVID-19 (PASC) or more commonly long-haul COVID. Interestingly, Long-haul COVID and many debilitating viral diseases display a similar range of clinical symptoms of muscle fatigue, dizziness, depression, and chronic inflammation. In our current hypothesis-driven review article, we attempt to discuss the molecular mechanism of muscle fatigue in long-haul COVID, and other viral diseases as caused by HHV6, Powassan, Epstein-Barr virus (EBV), and HIV. We also discuss the pathological resemblance of virus-triggered muscle fatigue with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS).

Linking Inflammation, Aberrant Glutamate-Dopamine Interaction, and Post-synaptic Changes: Translational Relevance for Schizophrenia and Antipsychotic Treatment: a Systematic Review

Evidence from clinical, preclinical, and post-mortem studies supports the inflammatory/immune hypothesis of schizophrenia pathogenesis. Less evident is the link between the inflammatory background and two well-recognized functional and structural findings of schizophrenia pathophysiology: the dopamine-glutamate aberrant interaction and the alteration of dendritic spines architecture, both believed to be the “quantal” elements of cortical-subcortical dysfunctional network. In this systematic review, we tried to capture the major findings linking inflammation, aberrant glutamate-dopamine interaction, and post-synaptic changes under a direct and inverse translational perspective, a paramount picture that at present is lacking. The inflammatory effects on dopaminergic function appear to be bidirectional: the inflammation influences dopamine release, and dopamine acts as a regulator of discrete inflammatory processes involved in schizophrenia such as dysregulated interleukin and kynurenine pathways. Furthermore, the link between inflammation and glutamate is strongly supported by clinical studies aimed at exploring overactive microglia in schizophrenia patients and maternal immune activation models, indicating impaired glutamate regulation and reduced N-methyl-D-aspartate receptor (NMDAR) function. In addition, an inflammatory/immune-induced alteration of post-synaptic density scaffold proteins, crucial for downstream NMDAR signaling and synaptic efficacy, has been demonstrated. According to these findings, a significant increase in plasma inflammatory markers has been found in schizophrenia patients compared to healthy controls, associated with reduced cortical integrity and functional connectivity, relevant to the cognitive deficit of schizophrenia. Finally, the link between altered inflammatory/immune responses raises relevant questions regarding potential new therapeutic strategies specifically for those forms of schizophrenia that are resistant to canonical antipsychotics or unresponsive to clozapine.

A New Approach to Understanding Cancer-Related Fatigue: Leveraging the 3P Model to Facilitate Risk Prediction and Clinical Care

Simple Summary

For the growing number of cancer survivors worldwide, fatigue presents a major hurdle to function and quality of life. Treatment options for cancer-related fatigue are still emerging, and our current understanding of its etiology is limited. In this paper, we describe a new application of a comprehensive model for cancer-related fatigue: the predisposing, precipitating, and perpetuating (3P) factors model. We propose that the 3P model may be leveraged—particularly using metabolomics, the microbiome, and inflammation in conjunction with behavioral science—to better understand the pathophysiology of cancer-related fatigue.

Abstract

A major gap impeding development of new treatments for cancer-related fatigue is an inadequate understanding of the complex biological, clinical, demographic, and lifestyle mechanisms underlying fatigue. In this paper, we describe a new application of a comprehensive model for cancer-related fatigue: the predisposing, precipitating, and perpetuating (3P) factors model. This model framework outlined herein, which incorporates the emerging field of metabolomics, may help to frame a more in-depth analysis of the etiology of cancer-related fatigue as well as a broader and more personalized set of approaches to the clinical treatment of fatigue in oncology care. Included within this review paper is an in-depth description of the proposed biological mechanisms of cancer-related fatigue, as well as a presentation of the 3P model’s application to this phenomenon. We conclude that a clinical focus on organization risk stratification and treatment around the 3P model may be warranted, and future research may benefit from expanding the 3P model to understand fatigue not only in oncology, but also across a variety of chronic conditions.

High-fat diet induced hippocampal CREB dysfunction, cognitive impairment and depression-like behaviors via downregulation of interleukin-2 in the mice

BACKGROUND

Inhibition of hippocampal CREB signaling contributed to obesity-induced cognitive impairment. But, the potential mechanism by which obesity inhibits hippocampal CREB signaling is not clear. The aim of this study was to explore whether interleukin-2 played a intermediary role in this pathogenic effect in a high-fat diet model.

METHODS

C57BL/6J interleukin-2^+/+ wild-type and interleukin-2^-/- knockout mice were fed a standard diet or high-fat diet for 12 weeks. After that, cognitive function was assessed by Morris water maze and Y maze. Depression-like behaviors were determined using sucrose preference test and tail suspension test. Expression of p-CREB and interleukin-2 in peripheral blood mononuclear cells and hippocampus was measured using western blotting and qRT-PCR.

RESULTS

In the interleukin-2^+/+ wild-type mice, a high-fat diet inhibited the expression of interleukin-2 and p-CREB both in the peripheral blood mononuclear cells and hippocampus. The high-fat diet also caused cognitive impairment and depression-like behaviors in these mice. In the interleukin-2^-/- knockout mice, there was no significant depression of interleukin-2. A high-fat diet can only aggravate the p-CREB signaling dysfunction in the peripheral blood mononuclear cells, but not in the hippocampus. Meanwhile, the high-fat diet can not cause the cognitive impairment and depression-like behaviors in these mice.

CONCLUSIONS

A high-fat diet induced hippocampal CREB dysfunction, cognitive impairment and depression-like behaviors partly through downregulation of interleukin-2 in the mice.

Transcriptomic signatures of psychomotor slowing in peripheral blood of depressed patients: evidence for immunometabolic reprogramming

Inflammation impacts basal ganglia motor circuitry in association with psychomotor retardation, a key symptom of major depression (MD). We previously reported associations between circulating protein inflammatory biomarkers and psychomotor slowing as measured by neuropsychological tests probing psychomotor speed in patients with MD. To discover novel transcriptional signatures in peripheral blood immune cells related to psychomotor slowing, microarray data were analyzed in a primary cohort of 88 medically-stable, unmedicated, ambulatory MD patients. Results were confirmed and extended in a second cohort of 57 patients with treatment resistant depression (TRD) before and after anti-inflammatory challenge with the tumor necrosis factor antagonist infliximab versus placebo. Composite scores reflecting pure motor and cognitive-motor processing speed were linearly associated with 403 and 266 gene transcripts in each cohort, respectively (|R| > 0.30, p < 0.01), that were enriched for cytokine signaling and glycolysis-related pathways (p < 0.05). Unsupervised clustering in the primary cohort revealed two psychomotor slowing-associated gene co-expression modules that were enriched for interferon, interleukin-6, aerobic glycolysis, and oxidative phosphorylation pathways (p < 0.05, q < 0.1). Transcripts were predominantly derived from monocytes, plasmacytoid dendritic cells, and natural killer cells (p's < 0.05). In infliximab-treated TRD patients with high plasma C-reactive protein concentrations (>5 mg/L), two differential co-expression modules enriched for oxidative stress and mitochondrial degradation were associated with improvements in psychomotor reaction time (p < 0.05). These results indicate that inflammatory signaling and associated metabolic reprogramming in peripheral blood immune cells are associated with systemic inflammation in depression and may affect relevant brain circuits to promote psychomotor slowing.

Plasma exosomes from depression ameliorate inflammation-induced depressive-like behaviors via sigma-1 receptor delivery

A growing body of studies indicated that exosomes are one of vital players in pathological process of neuropsychiatric diseases, but their role in major depressive disorder (MDD) remains poorly understood. Here we purified plasma exosomes from depression including lipopolysaccharide (LPS)-challenged depression, chronic restraint stress (CRS)-induced depression, MDD subjects, and from control mice or volunteers. The therapeutic effect of these exogenous exosomes was assessed utilizing behavioral tests and biochemical approaches in the LPS-caused depression or microglial BV2 cells. The expression of exosomal sigma-1 receptor (Sig-1R) was evaluated by western blotting. The role of Sig-1R in the biological function of exosomes was determined using Sig-1R knockout mice and HEK 293 cells. Our results revealed that injection of exosomes from depression models or patients rather than normal controls significantly ameliorated depressive-like behaviors, deficiency of BDNF expression and neuro-inflammation in LPS-challenged mice. In addition, co-culture with exosomes from depression models or patients instead of from controls prevented LPS-induced inflammation responses in microglial BV2 cells. Moreover, Sig-1R was demonstrated for the first time to significantly be enriched in exosomes from depression models or patients compared with that from normal controls. However, Sig-1R null exosomes no longer emerged antidepressant-like action in LPS-challenged mice. Thus, we demonstrated that plasma exosomes from depression exerted antidepressant-like effects in a Sig-1R dependent manner in the LPS-induced depression. This work improves our understanding of the exosomes in depression, suggesting a novel exosomes-based approach for MDD treatment.

Jianpi Jieyu Decoction, An Empirical Herbal Formula, Exerts Psychotropic Effects in Association With Modulation of Gut Microbial Diversity and GABA Activity

Background: Recent studies suggest that gut microbiota was associated with the bidirectional gut-brain axis which could modulate neuropsychological functions of the central nervous system. Gut microbiota could produce gamma aminobutyric acid (GABA) that could modulate the gut-brain axis response. Jianpi Jieyu (JPJY) decoction, a traditional Chinese formula, is mainly composed of Astragalus membranaxeus and Radix Pseudostellariae. Although the JPJY decoction has been used to treat the depression in China, the potential action of its antidepressant has not been well understood. Thus this study was aim to investigate the role of JPJY improve gut microbiota homeostasis in the chronic stress induced depressive mice. Methods: The antidepressant effect of JPJY on chronic unpredictable mild stress (CUMS) mice was evaluated by using sucrose preference test, tail suspension test and forced swim test. Fatigue-like behaviors were evaluated using degree of redness, grip strength test, and exhaustive swimming test. The new object recognition test was used to evaluate cognition performance. Fecal samples were collected and taxonomical analysis of intestinal microbial distribution was conducted with 16S rDNA. Serum level of GABA was measured using high performance liquid chromatography (HPLC). The expression of GluR1 and p-Tau protein in the hippocampus was determined using Western blotting. Results: The dose of 9.2 g/kg JPJY produced antidepressant-like effects. JPJY and its major components also modulated gut microbiota diversity in the CUMS mice. Serum level of GABA and the expressions of hippocampal GluR1 and p-Tau were reversed after the administration of JPJY in CUMS mice. Conclusion: JPJY regulates gut microbiota to produce antidepressant-like effect and improve cognition deficit in depressive mice while its molecular mechanism possibly be enhanced NR1 and Tau expression in hippocampus and increased GABA in serum.

Transcriptomic signaling pathways involved in a naturalistic model of inflammation-related depression and its remission

This study aimed at identifying molecular biomarkers of inflammation-related depression in order to improve diagnosis and treatment. For this, we performed whole-genome expression profiling from peripheral blood in a naturalistic model of inflammation-associated major depressive disorder (MDD) represented by comorbid depression in obese patients. We took advantage of the marked reduction of depressive symptoms and inflammation following bariatric surgery to test the robustness of the identified biomarkers. Depression was assessed during a clinical interview using Mini-International Neuropsychiatric Interview and the 10-item, clinician-administered, Montgomery-Asberg Depression Rating Scale. From a cohort of 100 massively obese patients, we selected 33 of them for transcriptomic analysis. Twenty-four of them were again analyzed 4-12 months after bariatric surgery. We conducted differential gene expression analyses before and after surgery in unmedicated MDD and non-depressed obese subjects. We found that TP53 (Tumor Protein 53), GR (Glucocorticoid Receptor), and NFκB (Nuclear Factor kappa B) pathways were the most discriminating pathways associated with inflammation-related MDD. These signaling pathways were processed in composite z-scores of gene expression that were used as biomarkers in regression analyses. Results showed that these transcriptomic biomarkers highly predicted depressive symptom intensity at baseline and their remission after bariatric surgery. While inflammation was present in all patients, GR signaling over-activation was found only in depressed ones where it may further increase inflammatory and apoptosis pathways. In conclusion, using an original model of inflammation-related depression and its remission without antidepressants, we provide molecular predictors of inflammation-related MDD and new insights in the molecular pathways involved.

Expression of IFN-induced 2'-5'-oligoadenylate synthetases correlates with immune infiltration, revealing potential targets and new biomarkers for basal-like breast cancer prognosis

Triple-negative breast cancer has been classified as basal-like immune activated (BLIA), basal-like immune-suppressed (BLIS), and two other subtypes, suggesting potential immune therapeutic targets for basal-like breast cancer (BLBC). 2'-5'-Oligoadenylate synthetases (OASs), identified from differentially expressed genes (DEGs) between BLIA and BLIS breast cancers (GSE76124), are involved in antiviral activity induced by interferons. However, the association between the four OASs and prognosis or tumor-infiltrating immune cells (TIICs) remains unclear. Expression, survival data, and immune correlations for OASs in BLBC were assessed using bioinformatics tools. We found that OASs were highly expressed in BLIA breast cancer. Survival analysis suggested that high transcriptional levels of OASs were associated with better overall survival, relapse-free survival, and distant metastasis-free survival in patients with BLBC. Moreover, the prognostic value of OASs with respect to different clinicopathological factors, and especially according to lymph node metastasis, in patients with BLBC was further assessed. Our findings elucidated the expression, prognostic role, and effect of OASs in TIICs on BLBC, which might promote the development of OAS-targeted immunotherapy for BLBC.

Minocycline augmentation in older adults with persistent depression: an open label proof of concept study

Less than 40% of depressed older adults treated with an antidepressant achieve remission. Incomplete response to treatment is common. Current augmentation strategies have limited efficacy, and many have side effects that restrict their utilization in older adults. We conducted the first open pilot trial of minocycline augmentation in older adults who had failed to achieve remission after adequate psychopharmacologic treatment. Subjects older than 55 years of age with major depression and failure to achieve substantial improvement of depressive symptoms after at least 6 weeks of antidepressant treatment were given augmentation with minocycline 100 mg twice daily over an 8-week period. At the end of 8 weeks of augmentation with minocycline, 31% (4/13) patients achieved remission. Remitters had higher baseline ratings of hopelessness and apathy. Minocycline was well tolerated with no reported adverse events or discontinuation due to intolerance. Larger placebo-controlled studies are needed to evaluate the effects of minocycline augmentation in older adults who had failed to achieve remission after adequate treatment with antidepressants.

The Cross-Talk Between the Dopaminergic and the Immune System Involved in Schizophrenia

Dopamine is one of the neurotransmitters whose transmission is altered in a number of neural pathways in the brain of schizophrenic patients. Current evidence indicates that these alterations involve hyperactive dopaminergic transmission in mesolimbic areas, striatum, and hippocampus, whereas hypoactive dopaminergic transmission has been reported in the prefrontal cortex of schizophrenic patients. Consequently, schizophrenia is associated with several cognitive and behavioral alterations. Of note, the immune system has been found to collaborate with the central nervous system in a number of cognitive and behavioral functions, which are dysregulated in schizophrenia. Moreover, emerging evidence has associated schizophrenia and inflammation. Importantly, different lines of evidence have shown dopamine as a major regulator of inflammation. In this regard, dopamine might exert strong regulation in the activity, migration, differentiation, and proliferation of immune cells that have been shown to contribute to cognitive functions, including T-cells, microglial cells, and peripheral monocytes. Thereby, alterations in dopamine levels associated to schizophrenia might affect inflammatory response of immune cells and consequently some behavioral functions, including reference memory, learning, social behavior, and stress resilience. Altogether these findings support the involvement of an active cross-talk between the dopaminergic and immune systems in the physiopathology of schizophrenia. In this review we summarize, integrate, and discuss the current evidence indicating the involvement of an altered dopaminergic regulation of immunity in schizophrenia.

Transcriptomic predictors of inflammation-induced depressed mood

Inflammation plays a significant role in the pathophysiology of depression. However, not all individuals exposed to inflammatory challenge develop depression, and identifying those at risk is necessary to develop targeted monitoring, prevention, and treatment strategies. Within a randomized double-blind placebo-controlled study (n = 115), we examined whether leukocyte transcriptome profiles predicted inflammation-induced depressed mood in volunteers who received low-dose intravenous endotoxin (n = 58; aged 18-50). At baseline, transcription factor (TF) activities were assessed using genome-wide transcriptional profiling of peripheral blood mononuclear cells and promoter-based bioinformatic analyses. Then, participants were administered endotoxin. Self-reported depressed mood was assessed using the Profile of Mood States. Based on extant studies linking transcriptional profiles to depressive disorder, we examined whether post-endotoxin depressed mood is predicted by baseline activity of TFs related to immune activation, sympathetic activation, and glucocorticoid insensitivity: respectively, nuclear factor kappa B (NF-kB), cAMP response element-binding protein (CREB), and glucocorticoid receptor (GR). Twenty-one participants (36%) experienced an increase in depressed mood from baseline to 2 h post endotoxin, when depressive response peaks. Bioinformatics analyses controlling for age, sex, ethnicity, body mass index, and physical sickness response revealed that post-endotoxin depressed mood was predicted by increased baseline activity of TFs related to inflammation (NF-kB) and beta-adrenergic signaling (CREB) and by decreased activity of GR-related TFs (P's < 0.001). Inflammation-induced depressed mood is predicted by peripheral transcriptome profiles related to immune activation, sympathetic activation, and glucocorticoid insensitivity. With further replication, these stress-related molecular profiles could be used for a novel genomic approach for identifying individuals at high-risk for the inflammatory subtype of depression.

Neuroimmunomodulation in Major Depressive Disorder: Focus on Caspase 1, Inducible Nitric Oxide Synthase, and Interferon-Gamma

Major depressive disorder (MDD) is one of the leading causes of disability worldwide, and its incidence is expected to increase. Despite tremendous efforts to understand its underlying biological mechanisms, MDD pathophysiology remains elusive and pharmacotherapy outcomes are still far from ideal. Low-grade chronic inflammation seems to play a key role in mediating the interface between psychological stress, depressive symptomatology, altered intestinal microbiology, and MDD onset. We review the available pre-clinical and clinical evidence of an involvement of pro-inflammatory pathways in the pathogenesis, treatment, and remission of MDD. We focus on caspase 1, inducible nitric oxide synthase, and interferon gamma, three inflammatory systems dysregulated in MDD. Treatment strategies aiming at targeting such pathways alone or in combination with classical therapies could prove valuable in MDD. Further studies are needed to assess the safety and efficacy of immune modulation in MDD and other psychiatric disorders with neuroinflammatory components.

Genetic contributions to self-reported tiredness

Self-reported tiredness and low energy, often called fatigue, are associated with poorer physical and mental health. Twin studies have indicated that this has a heritability between 6 and 50%. In the UK Biobank sample (N=108 976), we carried out a genome-wide association study (GWAS) of responses to the question, 'Over the last two weeks, how often have you felt tired or had little energy?' Univariate GCTA-GREML found that the proportion of variance explained by all common single-nucleotide polymorphisms for this tiredness question was 8.4% (s.e.=0.6%). GWAS identified one genome-wide significant hit (Affymetrix id 1:64178756_C_T; P=1.36 × 10-11). Linkage disequilibrium score regression and polygenic profile score analyses were used to test for shared genetic aetiology between tiredness and up to 29 physical and mental health traits from GWAS consortia. Significant genetic correlations were identified between tiredness and body mass index (BMI), C-reactive protein, high-density lipoprotein (HDL) cholesterol, forced expiratory volume, grip strength, HbA1c, longevity, obesity, self-rated health, smoking status, triglycerides, type 2 diabetes, waist-hip ratio, attention deficit hyperactivity disorder, bipolar disorder, major depressive disorder, neuroticism, schizophrenia and verbal-numerical reasoning (absolute rg effect sizes between 0.02 and 0.78). Significant associations were identified between tiredness phenotypic scores and polygenic profile scores for BMI, HDL cholesterol, low-density lipoprotein cholesterol, coronary artery disease, C-reactive protein, HbA1c, height, obesity, smoking status, triglycerides, type 2 diabetes, waist-hip ratio, childhood cognitive ability, neuroticism, bipolar disorder, major depressive disorder and schizophrenia (standardised β's had absolute values<0.03). These results suggest that tiredness is a partly heritable, heterogeneous and complex phenomenon that is phenotypically and genetically associated with affective, cognitive, personality and physiological processes.

Effort-related motivational effects of the pro-inflammatory cytokine interleukin-6: pharmacological and neurochemical characterization

RATIONALE

Motivational dysfunctions such as anergia, fatigue, and reduced effort expenditure are common in patients with depression and other disorders. Pro-inflammatory cytokines are implicated in depression, and cytokine administration induces motivational deficits in humans.

OBJECTIVES

These studies focused on the effects of the cytokine interleukin-6 (IL-6) on effort-related decision-making.

METHODS

Rats were assessed using the concurrent fixed ratio 5-lever pressing/chow feeding choice procedure, which measures the tendency of rats to work for a preferred food (high carbohydrate pellets) in the presence of a concurrently available but less preferred substitute (lab chow).

RESULTS

IL-6 (2.0-8.0 μg/kg IP) shifted choice behavior, significantly decreasing lever pressing and increasing chow intake. Further experiments showed that the adenosine A2A antagonist MSX-3 and the stimulant methylphenidate attenuated the effort-related impairments produced by IL-6, increasing lever pressing and decreasing chow intake in IL-6 treated rats. The same doses of IL-6 did not alter food intake or preference in parallel free-feeding choice studies, demonstrating that these low doses were not altering preference for the high carbohydrate pellets or generally suppressing appetite. Also, IL-6 did not affect body temperature. Microdialysis studies showed that 8.0 μg/kg IL-6 significantly decreased extracellular dopamine in nucleus accumbens core.

CONCLUSIONS

In summary, IL-6 reduces the tendency to work for food, even at low doses that do not produce fever or loss of appetite. Dopaminergic mechanisms may be involved in these effort-related effects. This research has implications for the involvement of cytokines in motivational dysfunctions such as anergia and fatigue.

Transcriptomics in Interferon-α-Treated Patients Identifies Inflammation-, Neuroplasticity- and Oxidative Stress-Related Signatures as Predictors and Correlates of Depression

Owing to the unique opportunity to assess individuals before and after they develop depression within a short timeframe, interferon-α (IFN-α) treatment for chronic hepatitis C virus (HCV) infection is an ideal model to identify molecular mechanisms relevant to major depression, especially in the context of enhanced inflammation. Fifty-eight patients were assessed prospectively, at baseline and monthly over 24 weeks of IFN-α treatment. New-onset cases of depression were determined using the Mini International Neuropsychiatric Interview (MINI). Whole-blood transcriptomic analyses were conducted to investigate the following: (1) baseline gene expression differences associated with future development of IFN-α-induced depression, before IFN-α, and (2) longitudinal gene expression changes from baseline to weeks 4 or 24 of IFN-α treatment, separately in those who did and did not develop depression. Transcriptomics data were analyzed using Partek Genomics Suite (1.4-fold, FDR adjusted p⩽0.05) and Ingenuity Pathway Analysis Software. Twenty patients (34%) developed IFN-α-induced depression. At baseline, 73 genes were differentially expressed in patients who later developed depression compared with those who did not. After 4 weeks of IFN-α treatment, 592 genes were modulated in the whole sample, representing primarily IFN-α-responsive genes. Substantially more genes were modulated only in patients who developed depression (n=506, compared with n=70 in patients who did not), with enrichment in inflammation-, neuroplasticity- and oxidative stress-related pathways. A similar picture was observed at week 24. Our data indicate that patients who develop IFN-α-induced depression have an increased biological sensitivity to IFN-α, as shown by larger gene expression changes, and specific signatures both as predictors and as correlates.

Multiplexing and Beyond in Biobehavioral Research

In contrast to traditional singleplex assays that provide values for only a single analyte in a single biological sample, multiplex assays are a time- and resource-efficient high-throughput approach that provides the opportunity to determine numerous analytes within a single- and small-sample volume. In this editorial on an article by Dorn et al. in this issue of Psychosomatic Medicine, we provide a brief description of the advantages and challenges related to multiplex assays. Although the use of multiplexing as a tool has been relatively limited in biobehavioral research, more recent studies are taking advantage of this technology to obtain deeper insight into regulatory patterns in health and disease states. Multiplex approaches range from several targets to global target profiling that importantly enable unbiased biomarker and pathway discovery.

Epigenetic differences in monozygotic twins discordant for major depressive disorder

Although monozygotic (MZ) twins share the majority of their genetic makeup, they can be phenotypically discordant on several traits and diseases. DNA methylation is an epigenetic mechanism that can be influenced by genetic, environmental and stochastic events and may have an important impact on individual variability. In this study we explored epigenetic differences in peripheral blood samples in three MZ twin studies on major depressive disorder (MDD). Epigenetic data for twin pairs were collected as part of a previous study using 8.1-K-CpG microarrays tagging DNA modification in white blood cells from MZ twins discordant for MDD. Data originated from three geographical regions: UK, Australia and the Netherlands. Ninety-seven MZ pairs (194 individuals) discordant for MDD were included. Different methods to address non independently-and-identically distributed (non-i.i.d.) data were evaluated. Machine-learning methods with feature selection centered on support vector machine and random forest were used to build a classifier to predict cases and controls based on epivariations. The most informative variants were mapped to genes and carried forward for network analysis. A mixture approach using principal component analysis (PCA) and Bayes methods allowed to combine the three studies and to leverage the increased predictive power provided by the larger sample. A machine-learning algorithm with feature reduction classified affected from non-affected twins above chance levels in an independent training-testing design. Network analysis revealed gene networks centered on the PPAR-γ (NR1C3) and C-MYC gene hubs interacting through the AP-1 (c-Jun) transcription factor. PPAR-γ (NR1C3) is a drug target for pioglitazone, which has been shown to reduce depression symptoms in patients with MDD. Using a data-driven approach we were able to overcome challenges of non-i.i.d. data when combining epigenetic studies from MZ twins discordant for MDD. Individually, the studies yielded negative results but when combined classification of the disease state from blood epigenome alone was possible. Network analysis revealed genes and gene networks that support the inflammation hypothesis of MDD.

Alterations in leukocyte transcriptional control pathway activity associated with major depressive disorder and antidepressant treatment

Major depressive disorder (MDD) is associated with a significantly elevated risk of developing serious medical illnesses such as cardiovascular disease, immune impairments, infection, dementia and premature death. Previous work has demonstrated immune dysregulation in subjects with MDD. Using genome-wide transcriptional profiling and promoter-based bioinformatic strategies, we assessed leukocyte transcription factor (TF) activity in leukocytes from 20 unmedicated MDD subjects versus 20 age-, sex- and ethnicity-matched healthy controls, before initiation of antidepressant therapy, and in 17 of the MDD subjects after 8 weeks of sertraline treatment. In leukocytes from unmedicated MDD subjects, bioinformatic analysis of transcription control pathway activity indicated an increased transcriptional activity of cAMP response element-binding/activating TF (CREB/ATF) and increased activity of TFs associated with cellular responses to oxidative stress (nuclear factor erythroid-derived 2-like 2, NFE2l2 or NRF2). Eight weeks of antidepressant therapy was associated with significant reductions in Hamilton Depression Rating Scale scores and reduced activity of NRF2, but not in CREB/ATF activity. Several other transcriptional regulation pathways, including the glucocorticoid receptor (GR), nuclear factor kappa-B cells (NF-κB), early growth response proteins 1-4 (EGR1-4) and interferon-responsive TFs, showed either no significant differences as a function of disease or treatment, or activities that were opposite to those previously hypothesized to be involved in the etiology of MDD or effective treatment. Our results suggest that CREB/ATF and NRF2 signaling may contribute to MDD by activating immune cell transcriptome dynamics that ultimately influence central nervous system (CNS) motivational and affective processes via circulating mediators.

MicroRNA let-7g cooperates with interferon/ribavirin to repress hepatitis C virus replication

MicroRNAs (miRNA) have been implicated in HCV infection. The present study analyzed the effects of let-7g on HCV infection in vitro, in clinical tissue and serum samples. Here, we show that the expression of let-7g in serum and liver tissue is significantly higher in patients with sustained virologic response (SVR). We show that interferon (IFN)/ribavirin (RBV) induces let-7g expression through p38/AP-1 signaling. Overexpression of let-7g reduced HCV gene or core protein level and inhibited the HCV viral load. The let-7g and IFN/RBV have additively inhibitory effect on HCV replication. These data implicate let-7g as a new therapeutic drug to additively cooperate with IFN/RBV to repress HCV replication. Key messages: let-7g expression is increased in serum and liver tissue of patients with SVR. Interferon/ribavirin induces let-7g expression through p38/AP-1 signaling. Overexpression of let-7g can repress HCV replication. Let-7g additively cooperates with interferon/ribavirin to repress HCV replication. Lin28B silencing can reverse let-7g expression and repress HCV replication.

Effects of Viral Eradication With Ledipasvir and Sofosbuvir, With or Without Ribavirin, on Measures of Fatigue in Patients With Chronic Hepatitis C Virus Infection

BACKGROUND & AIMS

Fatigue is a disturbing symptom of chronic hepatitis C virus (HCV) infection. We assessed the effects of sustained virologic response 12 weeks after the end of therapy (SVR12) on fatigue.

METHODS

We performed a retrospective analysis of 100 patients with chronic HCV infection who achieved an SVR12 after treatment with ledipasvir and sofosbuvir, with or without ribavirin. Data were collected on fatigue-related patient-reported outcomes (PROs) and assessed by using the Functional Assessment of Cancer Therapy-Fatigue scoring system and the Vitality subscale of Short Form 36. We measured levels of cytokines and growth factors in frozen serum samples collected at baseline, week 12 of treatment, and 4 weeks after treatment. Central fatigue and peripheral or muscle fatigue (PF) were determined by using items from PROs. Serum levels of cytokines, growth factors, serotonin, alanine aminotransferase, and aspartate aminotransferase were measured by using the Bio-Plex, enzyme-linked immunosorbent, and enzymatic assays.

RESULTS

Compared with baseline, 4 weeks after the end of treatment, all fatigue-associated PROs improved significantly. Baseline PROs correlated inversely with serum level of interferon-γ; level of platelet-derived growth factor correlated with PF, central fatigue, and total fatigue score. Only PF correlated with serum level of serotonin. At baseline, high PF scores correlated with high serum levels of serotonin and low levels of interleukin-10 and tumor necrosis factor-α. In multivariate analysis, serum level of interleukin-8 was associated with greater fatigue (P < .02). Reductions in levels of chemokine (C-C motif) ligand 2 (also called monocyte chemotactic protein 1) were associated with fatigue after treatment (P = .0165).

CONCLUSIONS

In an analysis of data from patients with chronic HCV infection participating in a clinical trial of ledipasvir and sofosbuvir, SVR12 was associated with reduced fatigue, compared with baseline. High baseline serum levels of interferon-γ were associated with fatigue. Reductions in levels of chemokine (C-C motif) ligand 2 were associated with persistent fatigue after SVR12. Central and peripheral fatigue each associated with different biomarkers, suggesting different pathogenic pathways.

Interferon-alpha-induced inflammation is associated with reduced glucocorticoid negative feedback sensitivity and depression in patients with hepatitis C virus

Major medical illnesses are associated with increased risk for depression and alterations in hypothalamic-pituitary-adrenal (HPA) axis function. Pathophysiological processes such as inflammation that occur as a part of medical illnesses and their treatments have been shown to cause depressive symptoms, and may also affect the HPA axis. We previously reported that patients with hepatitis C virus chronically administered interferon (IFN)-alpha develop increased evening plasma cortisol concentrations and a flattened diurnal cortisol slope, which correlated with increased tumor necrosis factor (TNF) and its soluble receptor 2 (sTNFR2). Increased TNF and sTNFR2 were further correlated with depression and fatigue scores. The current study examined whether flattened cortisol slope might be secondary to reduced glucocorticoid receptor (GR) sensitivity, by measuring glucocorticoid negative feedback to dexamethasone (DEX) administration followed by corticotropin releasing hormone (CRH) challenge. In an exploratory analysis, 28 male and female patients with hepatitis C virus were studied at baseline (Visit 1) and after 12weeks (Visit 2) of either IFN-alpha plus ribavirin (n=17) or no treatment (n=11). Patients underwent dexamethasone DEX-CRH challenge, neuropsychiatric assessments, and measurement of plasma TNF and sTNFR2 during each visit. IFN-alpha did not affect neuroendocrine responses following CRH but did increase post-DEX cortisol, which was correlated with flattening of the diurnal cortisol slope (r=0.57, p=0.002) and with increased depression scores (r=0.38, p=0.047). Furthermore, the change in post-DEX cortisol was associated with IFN-alpha-induced increase in sTNFR2 (r=0.51, p=006), which was in turn correlated with depression (r=0.63, p<0.001) and fatigue (r=0.51, p=0.005) scores. Whereas the relationship between sTNFR2 and depression scores were independent of the change in post-DEX cortisol, the correlation between post-DEX cortisol and depression scores was not significant when controlling for sTNFR2. These findings suggest that inflammation induced in patients with hepatitis C virus during IFN-alpha therapy precipitates decreased GR sensitivity to lead to a flattened diurnal cortisol slope. Decreased GR sensitivity may in turn further increase inflammation and its ultimate effects on behavior. Treatments that target inflammation and/or GR sensitivity may reduce depressive symptoms associated with medical illnesses.

Lipopolysaccharide-induced depressive-like behavior is associated with α₁-adrenoceptor dependent downregulation of the membrane GluR1 subunit in the mouse medial prefrontal cortex and ventral tegmental area

BACKGROUND

Chronic stress-induced depressive-like behavior is relevant to inflammatory immune activation. However, the neurobiological alterations in the brain following the central inflammatory immune activation remain elusive.

METHODS

Therefore, we investigated the neurobiological alterations during depressive-like behavior induced in mice by systemic administration of lipopolysaccharide (LPS; 1.2 mg/kg administered twice at a 30-min interval via intraperitoneal injection).

RESULTS

At 24 h after the second administration of LPS, an increased immobility time in the tail suspension test and the forced swimming test were observed, as well as reduced sucrose preference. Protein levels of the AMPA receptor GluR1 were significantly decreased at the plasma membrane in the medial prefrontal cortex (mPFC) and ventral tegmental area (VTA), while levels of the GluR2 were increased at the plasma membrane in the nucleus accumbens (NAc) at 24h after LPS. However, total GluR1 and GluR2 protein levels in the mPFC, VTA, and NAc were not affected by LPS. Moreover, LPS facilitated release of noradrenaline in the mPFC and VTA, but not in the NAc. Consistently, systemic administration of prazosin, an α1-adrenoceptor antagonist, blocked the LPS-induced downregulation of the membrane GluR1 subunit in both the mPFC and VTA and also blocked the upregulation of the membrane GluR2 subunit in the NAc. Intracerebroventricular administration of prazosin 30 min before LPS injection abrogated the LPS-induced depressive-like behaviors. In opposition, administration of propranolol, a β-adrenoceptor antagonist, did not affect the LPS-induced downregulation of GluR1, the upregulation of GluR2, or the depressive-like behavior.

CONCLUSIONS

These results suggest that LPS-activated α1-adrenoceptor-induced downregulation of membrane GluR1 in the mPFC and VTA is associated with inflammation-induced depressive-like behavior.

Type I interferon signaling genes in recurrent major depression: increased expression detected by whole-blood RNA sequencing

A study of genome-wide gene expression in major depressive disorder (MDD) was undertaken in a large population-based sample to determine whether altered expression levels of genes and pathways could provide insights into biological mechanisms that are relevant to this disorder. Gene expression studies have the potential to detect changes that may be because of differences in common or rare genomic sequence variation, environmental factors or their interaction. We recruited a European ancestry sample of 463 individuals with recurrent MDD and 459 controls, obtained self-report and semi-structured interview data about psychiatric and medical history and other environmental variables, sequenced RNA from whole blood and genotyped a genome-wide panel of common single-nucleotide polymorphisms. We used analytical methods to identify MDD-related genes and pathways using all of these sources of information. In analyses of association between MDD and expression levels of 13 857 single autosomal genes, accounting for multiple technical, physiological and environmental covariates, a significant excess of low P-values was observed, but there was no significant single-gene association after genome-wide correction. Pathway-based analyses of expression data detected significant association of MDD with increased expression of genes in the interferon α/β signaling pathway. This finding could not be explained by potentially confounding diseases and medications (including antidepressants) or by computationally estimated proportions of white blood cell types. Although cause-effect relationships cannot be determined from these data, the results support the hypothesis that altered immune signaling has a role in the pathogenesis, manifestation, and/or the persistence and progression of MDD.

Disease and treatment characteristics do not predict symptom occurrence profiles in oncology outpatients receiving chemotherapy

BACKGROUND

A large amount of interindividual variability exists in the occurrence of symptoms in patients receiving chemotherapy (CTX). The purposes of the current study, which was performed in a sample of 582 oncology outpatients who were receiving CTX, were to identify subgroups of patients based on their distinct experiences with 25 commonly occurring symptoms and to identify demographic and clinical characteristics associated with subgroup membership. In addition, differences in quality of life outcomes were evaluated.

METHODS

Oncology outpatients with breast, gastrointestinal, gynecological, or lung cancer completed the Memorial Symptom Assessment Scale before their next cycle of CTX. Latent class analysis was used to identify subgroups of patients with distinct symptom experiences.

RESULTS

Three distinct subgroups of patients were identified (ie, 36.1% in Low class; 50.0% in Moderate class, and 13.9% in All High class). Patients in the All High class were significantly younger and more likely to be female and nonwhite, and had lower levels of social support, lower socioeconomic status, poorer functional status, and a higher level of comorbidity.

CONCLUSIONS

Findings from the current study support the clinical observation that some oncology patients experience a differentially higher symptom burden during CTX. These high-risk patients experience significant decrements in quality of life.

Effort-related motivational effects of the pro-inflammatory cytokine interleukin 1-beta: studies with the concurrent fixed ratio 5/ chow feeding choice task

RATIONALE

Effort-related motivational symptoms such as anergia and fatigue are common in patients with depression and other disorders. Research implicates pro-inflammatory cytokines in depression, and administration of cytokines can induce effort-related motivational symptoms in humans.

OBJECTIVES

The present experiments focused on the effects of the pro-inflammatory cytokine interleukin 1-beta (IL-1β) on effort-related choice behavior.

METHODS

Rats were tested on a concurrent fixed ratio 5 lever pressing/chow feeding choice procedure, which assesses the tendency of rats to work for a preferred food (high carbohydrate pellets) in the presence of a concurrently available but less preferred substitute (laboratory chow).

RESULTS

IL-1β (1.0-4.0 μg/kg IP) shifted choice behavior, significantly decreasing lever pressing and increasing intake of the freely available chow. The second experiment assessed the ability of the adenosine A2A antagonist (E)-phosphoric acid mono-[3-[8-[2-(3-methoxyphenyl)vinyl]-7-methyl-2,6-dioxo-1-prop-2-ynyl-1,2,6,7-tetrahydropurin-3-yl] propyl] ester disodium salt (MSX-3) to reverse the behavioral effects of IL-1β. MSX-3 attenuated the effort-related impairments produced by IL-1β, increasing lever pressing and also decreasing chow intake. In the same dose range that shifted effort-related choice behavior, IL-1β did not alter food intake or preference in parallel free-feeding choice studies, indicating that these low doses were not generally suppressing appetite or altering preference for the high carbohydrate pellets. In addition, IL-1β did not affect core body temperature.

CONCLUSIONS

These results indicate that IL-1β can reduce the tendency to work for food, even at low doses that do not produce a general sickness, malaise, or loss of appetite. This research has implications for the involvement of cytokines in motivational symptoms such as anergia and fatigue.

Differing leukocyte gene expression profiles associated with fatigue in patients with prostate cancer versus chronic fatigue syndrome

BACKGROUND

Androgen deprivation therapy (ADT) often worsens fatigue in patients with prostate cancer, producing symptoms similar to chronic fatigue syndrome (CFS). Comparing expression (mRNA) of many fatigue-related genes in patients with ADT-treated prostate cancer versus with CFS versus healthy controls, and correlating mRNA with fatigue severity may clarify the differing pathways underlying fatigue in these conditions.

METHODS

Quantitative real-time PCR was performed on leukocytes from 30 fatigued, ADT-treated prostate cancer patients (PCF), 39 patients with CFS and 22 controls aged 40-79, together with ratings of fatigue and pain severity. 46 genes from these pathways were included: (1) adrenergic/monoamine/neuropeptides, (2) immune, (3) metabolite-detecting, (4) mitochondrial/energy, (5) transcription factors.

RESULTS

PCF patients showed higher expression than controls or CFS of 2 immune transcription genes (NR3C1 and TLR4), chemokine CXCR4, and mitochondrial gene SOD2. They showed lower expression of 2 vasodilation-related genes (ADRB2 and VIPR2), 2 cytokines (TNF and LTA), and 2 metabolite-detecting receptors (ASIC3 and P2RX7). CFS patients showed higher P2RX7 and lower HSPA2 versus controls and PCF. Correlations with fatigue severity were similar in PCF and CFS for only DBI, the GABA-A receptor modulator (r=-0.50, p<0.005 and r=-0.34, p<0.05). Purinergic P2RY1 was correlated only with PCF fatigue and pain severity (r=+0.43 and +0.59, p=0.025 and p=0.001).

CONCLUSIONS

PCF patients differed from controls and CFS in mean expression of 10 genes from all 5 pathways. Correlations with fatigue severity implicated DBI for both patient groups and P2RY1 for PCF only. These pathways may provide new targets for interventions to reduce fatigue.

The effect of cell subset isolation method on gene expression in leukocytes

Multiple scientific disciplines require the isolation of specific subsets of blood cells from patient samples for gene expression analysis by microarray or RNA-sequencing, preserving disease- or treatment-related signatures. However, little is known with respect to the impact of different cell isolation methods on gene expression and the effects of positive selection, negative selection, and fluorescence activated cell sorting (FACS) have not previously been assessed in parallel. To address this knowledge gap, CD4+ T cells, CD8+ T cells, B cells, and monocytes were isolated from blood samples from five independent donors using positive immunomagnetic selection, negative immunomagnetic selection, and FACS. We hypothesized that positive selection and FACS would yield higher purity but may have an impact on gene expression since both methods utilize antibodies that bind surface receptors of the cell type of interest. Moreover, FACS might upregulate stress response genes due to passage of the cells through the sorter. Microarray gene expression data were generated and subjected to unsupervised clustering and differential gene expression analysis. Surprisingly, these analyses revealed that gene expression signatures were more similar between cells isolated by negative selection and FACS compared to cells isolated by positive selection. Moreover, genes that are involved in the response to stress generally had the highest expression in cells isolated by negative or positive selection and not FACS. Thus, FACS is the recommended method for isolation of leukocyte subsets for gene expression studies since this method results in the purest subset populations and does not appear to induce a stress response.

Tyrosine metabolism during interferon-alpha administration: association with fatigue and CSF dopamine concentrations

Chronic exposure to interferon (IFN)-alpha, an innate immune cytokine, produces high rates of behavioral disturbances, including depression and fatigue. These effects may be mediated by the actions of IFN-alpha on dopamine (DA) metabolism in the basal ganglia. Diminished conversion of phenylalanine (Phen) to tyrosine (Tyr), the primary amino acid precursor of DA, has been associated with inflammation, and may reflect decreased activity of the enzyme phenylalanine-hydroxylase (PAH). This study investigated the peripheral Phen/Tyr ratio in relation to cerebrospinal fluid (CSF) concentrations of DA and its metabolites in subjects treated with IFN-alpha plus ribavirin for hepatitis C and controls awaiting IFN-alpha therapy. Plasma Phen/Tyr ratios were significantly increased in IFN-alpha-treated subjects (n=25) compared to controls (n=9), and were negatively correlated with CSF DA (r=-0.59, df=15, p<0.05) and its metabolite, homovanillic acid (r=-0.67, df=15, p<0.01), and positively correlated with fatigue (r=0.44, df=23, p<.05) in IFN-alpha-treated patients but not controls. Given the role of tetrahydrobiopterin (BH4) in the PAH conversion of Phen to Tyr, CSF concentrations of BH4 and its inactive oxidized form, dihydrobiopterin (BH2), were examined along with CSF interleukin (IL)-6 in a subset of patients. BH2 concentrations were significantly increased in IFN-alpha-treated patients (n=12) compared to controls (n=7), and decreased CSF BH4 concentrations correlated with increased CSF IL-6 (r=-0.57, df=12, p<0.05). These results indicate that IFN-alpha is associated with decreased peripheral conversion of Phen to Tyr, which in turn is associated with reduced DA in the brain as well as fatigue. These alterations may be related to oxidation of BH4 secondary to IFN-alpha-induced activation of a CNS inflammatory response.

Transcriptional signatures related to glucose and lipid metabolism predict treatment response to the tumor necrosis factor antagonist infliximab in patients with treatment-resistant depression

The tumor necrosis factor (TNF) antagonist infliximab was recently found to reduce depressive symptoms in patients with increased baseline inflammation as reflected by a plasma C-reactive protein concentration >5 mg/L. To further explore predictors and targets of response to infliximab, differential gene expression was examined in peripheral blood mononuclear cells from infliximab responders (n=13) versus non-responders (n=14) compared to placebo at baseline and 6 h, 24 h, and 2 weeks after the first infliximab infusion. Treatment response was defined as 50% reduction in depressive symptoms at any point during the 12-week trial. One-hundred-forty-eight gene transcripts were significantly associated (1.2-fold, adjusted p≤0.01) with response to infliximab and were distinct from placebo responders. Transcripts predictive of infliximab response were associated with gluconeogenesis and cholesterol transport, and were enriched in a network regulated by hepatocyte nuclear factor (HNF)4-alpha, a transcription factor involved in gluconeogenesis and cholesterol and lipid homeostasis. Of the 148 transcripts differentially expressed at baseline, 48% were significantly regulated over time in infliximab responders, including genes related to gluconeogenesis and the HNF4-alpha network, indicating that these predictive genes were responsive to infliximab. Responders also demonstrated inhibition of genes related to apoptosis through TNF signaling at 6 h and 24 h after infusion. Transcripts down-regulated in responders 2 weeks after infliximab were related to innate immune signaling and nuclear factor-kappa B. Thus, baseline transcriptional signatures reflective of alterations in glucose and lipid metabolism predicted antidepressant response to infliximab, and infliximab response involved regulation of metabolic genes and inhibition of genes related to innate immune activation.

Dysregulated relationship of inflammation and oxidative stress in major depression

Chronic inflammation and oxidative stress have been implicated in the pathophysiology of Major Depressive Disorder (MDD), as well as in a number of chronic medical conditions. The aim of this study was to examine the relationship between peripheral inflammatory and oxidative stress markers in un-medicated subjects with MDD compared to non-depressed healthy controls and compared to subjects with MDD after antidepressant treatment. We examined the relationships between IL-6, IL-10, and the IL-6/IL-10 inflammatory ratio vs. F2-isoprostanes (F2-IsoP), a marker of oxidative stress, in un-medicated MDD patients (n=20) before and after 8 weeks of open-label sertraline treatment (n=17), compared to healthy non-depressed controls (n=20). Among the un-medicated MDD subjects, F2-IsoP concentrations were positively correlated with IL-6 concentrations (p<0.05) and were negatively correlated with IL-10 concentrations (p<0.01). Accordingly, F2-IsoP concentrations were positively correlated with the ratio of IL-6/IL-10 (p<0.01). In contrast, in the control group, there were no significant correlations between F2-IsoPs and either cytokine or their ratio. After MDD subjects were treated with sertraline for 8 weeks, F2-IsoPs were no longer significantly correlated with IL-6, IL-10 or the IL-6/IL-10 ratio. These data suggest oxidative stress and inflammatory processes are positively associated in untreated MDD. Our findings are consistent with the hypothesis that the homeostatic buffering mechanisms regulating oxidation and inflammation in healthy individuals become dysregulated in untreated MDD, and may be improved with antidepressant treatment. These findings may help explain the increased risk of comorbid medical illnesses in MDD.

Inflammatory cytokines in depression: neurobiological mechanisms and therapeutic implications

Mounting evidence indicates that inflammatory cytokines contribute to the development of depression in both medically ill and medically healthy individuals. Cytokines are important for development and normal brain function, and have the ability to influence neurocircuitry and neurotransmitter systems to produce behavioral alterations. Acutely, inflammatory cytokine administration or activation of the innate immune system produces adaptive behavioral responses that promote conservation of energy to combat infection or recovery from injury. However, chronic exposure to elevated inflammatory cytokines and persistent alterations in neurotransmitter systems can lead to neuropsychiatric disorders and depression. Mechanisms of cytokine behavioral effects involve activation of inflammatory signaling pathways in the brain that results in changes in monoamine, glutamate, and neuropeptide systems, and decreases in growth factors, such as brain-derived neurotrophic factor. Furthermore, inflammatory cytokines may serve as mediators of both environmental (e.g. childhood trauma, obesity, stress, and poor sleep) and genetic (functional gene polymorphisms) factors that contribute to depression's development. This review explores the idea that specific gene polymorphisms and neurotransmitter systems can confer protection from or vulnerability to specific symptom dimensions of cytokine-related depression. Additionally, potential therapeutic strategies that target inflammatory cytokine signaling or the consequences of cytokines on neurotransmitter systems in the brain to prevent or reverse cytokine effects on behavior are discussed.

Nervous system regulation of the cancer genome

Genomics-based analyses have provided deep insight into the basic biology of cancer and are now clarifying the molecular pathways by which psychological and social factors can regulate tumor cell gene expression and genome evolution. This review summarizes basic and clinical research on neural and endocrine regulation of the cancer genome and its interactions with the surrounding tumor microenvironment, including the specific types of genes subject to neural and endocrine regulation, the signal transduction pathways that mediate such effects, and therapeutic approaches that might be deployed to mitigate their impact. Beta-adrenergic signaling from the sympathetic nervous system has been found to up-regulated a diverse array of genes that contribute to tumor progression and metastasis, whereas glucocorticoid-regulated genes can inhibit DNA repair and promote cancer cell survival and resistance to chemotherapy. Relationships between socio-environmental risk factors, neural and endocrine signaling to the tumor microenvironment, and transcriptional responses by cancer cells and surrounding stromal cells are providing new mechanistic insights into the social epidemiology of cancer, new therapeutic approaches for protecting the health of cancer patients, and new molecular biomarkers for assessing the impact of behavioral and pharmacologic interventions.

Neuropsychiatric and psychosocial issues of patients with hepatitis C infection: a selective literature review

CONTEXT

We briefly reviewed the evidence on the association of hepatitis C (HCV) infection with several aspects of mental and psychosocial health.

EVIDENCE ACQUISITION

Medline was searched with appropriate keywords. The primary sources were the systematic reviews. If systematic reviews were not available for a subject, then the most relevant and methodologically sound original studies were selected.

RESULTS

HCV infection is associated with poorer health-related quality of life, and physical, mental, and social health. A part of impaired health of these patients is related to cirrhosis, intravenous drug use, co morbid psychiatric disorders, stigmatization, poor social support, alcohol abuse, and interferon treatment. However, HCV itself is also associated with poorer health status particularly in the physical and cognitive domains, which might be related to brain alterations induced by the virus. Interferon treatment is an important cause of depression in HCV patients and sometimes is associated with irritability, manic episode, or acute confusional state. Social health of HCV patients is significantly impaired by stigmatization, poor social support, psychiatric comorbidties, and impaired coping. Psychosocial impairment of HCV patients significantly impairs their treatment adherence. A supportive and nonjudgmental multidisciplinary team is required for optimal management of these patients.

CONCLUSIONS

Patients with HCV infection had complex neuropsychiatric and psychosocial problems. These problems are challenges for management of HCV infection, affect the patient's care significantly, and might alter the course of the disease. A multidisciplinary approach, a supportive environment, and a nonjudgmental healthcare team are required for optimal medical and psychosocial management of patients with HCV.

Fatigue before, during and after antiviral therapy of chronic hepatitis C: results from the Virahep-C study

BACKGROUND & AIMS

Fatigue is the most frequent and often debilitating symptom of chronic hepatitis C. It is unclear whether successful therapy of hepatitis C leads to its clinical improvement. In the Virahep-C study, patients with hepatitis C virus (HCV) genotype 1 infection were treated with peginterferon alfa-2a and ribavirin for up to 48 weeks while undergoing assessment of viral kinetics and clinical symptoms.

METHODS

Fatigue measurements were conducted, before, during and after therapy, as 'presence' (yes/no) and 'severity' (visual analog scale: 0-100mm). The clinical, histologic, and virologic features that correlated with the presence and degree of fatigue were assessed focusing upon changes associated with sustained virological response (SVR).

RESULTS

At baseline, 52% (n=401) of participants reported having fatigue, which was more common in women than men (59% vs. 48%, p=0.02) and slightly more severe (30 vs. 22 mm, p=0.056). Fatigue was frequent and worse in cirrhotics versus those with lesser fibrosis (66% vs. 49%; 34 vs. 24 mm). Fatigue did not correlate with other parameters. The proportion of patients and median fatigue scores increased on treatment (52-78%; 25-40 mm, p<0.0001) with higher fatigue noted amongst those who ultimately achieved SVR (p<0.0001). On achieving SVR, there was a significant decrease in both frequency and severity of fatigue compared to their baseline (53-33%; 27-13 mm, both p<0.0001).

CONCLUSIONS

Fatigue is common in patients with chronic hepatitis C but is poorly associated with biochemical parameters. Sustained response is accompanied by substantial improvement of fatigue.