Neuroimmune Activation and Microglia Reactivity in Female Rats Following Alcohol Dependence.

The rates of alcohol use disorder among women are growing, yet little is known about how the female brain is affected by alcohol. The neuroimmune system, and specifically microglia, have been implicated in mediating alcohol neurotoxicity, but most preclinical studies have focused on males. Further, few studies have considered changes to the microglial phenotype when examining the effects of ethanol on brain structure and function. Therefore, we quantified microglial reactivity in female rats using a binge model of alcohol dependence, assessed through morphological and phenotypic marker expression, coupled with regional cytokine levels. In a time- and region-dependent manner, alcohol altered the microglial number and morphology, including the soma and process area, and the overall complexity within the corticolimbic regions examined, but no significant increases in the proinflammatory markers MHCII or CD68 were observed. The majority of cytokine and growth factor levels examined were similarly unchanged. However, the expression of the proinflammatory cytokine TNFα was increased, and the anti-inflammatory IL-10, decreased. Thus, female rats showed subtle differences in neuroimmune reactivity compared to past work in males, consistent with reports of enhanced neuroimmune responses in females across the literature. These data suggest that specific neuroimmune reactions in females may impact their susceptibility to alcohol neurotoxicity and other neurodegenerative events with microglial contributions.

Sex differences in microglia function in aged rats underlie vulnerability to cognitive decline.

Aging is associated with a significant shift in immune system reactivity ("inflammaging"), as basal inflammation increases but protective responses to infection are compromised. The immune system exhibits considerable sex differences, which may influence the process of inflammaging, including immune cell activation and behavioral consequences of immune signaling (i.e., impaired memory). Here, we test the hypothesis that sex differences in immune aging may mediate sex differences in cognitive decline. Aged male and female rats received peripheral immune stimulation using lipopolysaccharide (LPS), then molecular, cellular, and behavioral outcomes were assessed. We observed that LPS-treated aged male rats showed cognitive impairment and increased neuroinflammatory responses relative to adult males. In contrast, aged female rats did not display these aging-related deficits. Using transcriptomic and flow cytometry analyses, we further observed significant age- and sex- dependent changes in immune cell populations in the brain parenchyma and meninges, indicating a broad shift in the neuroinflammatory environment that may potentiate these behavioral effects. Ovariectomized aged female rats were also resistant to inflammation-induced memory deficits, indicating that ovarian hormones are not required for the attenuated neuroinflammation in aged females. Overall, our results indicate that males have amplified inflammatory priming with age, which contributes to age-associated cognitive decline. Our findings highlight sexual dimorphism in mechanisms of aging, and suggest that sex is a crucial consideration for identifying therapies for aging and neuroinflammation.

Primed for addiction: A critical review of the role of microglia in the neurodevelopmental consequences of adolescent alcohol drinking.

Alcohol is one of the most widely used recreational substances worldwide, with drinking frequently initiated during adolescence. The developmental state of the adolescent brain makes it vulnerable to initiating alcohol use, often in high doses, and particularly susceptible to alcohol-induced brain changes. Microglia, the brain parenchymal macrophages, have been implicated in mediating some of these effects, though the role that these cells play in the progression from alcohol drinking to dependence remains unclear. Microglia are uniquely positioned to sense and respond to central nervous system insult, and are now understood to exhibit innate immune memory, or "priming," altering their future functional responses based on prior exposures. In alcohol use disorders (AUDs), the role of microglia is debated. Whereas microglial activation can be pathogenic, contributing to neuroinflammation, tissue damage, and behavioral changes, or protective, it can also engage protective functions, providing support and mediating the resolution of damage. Understanding the role of microglia in adolescent AUDs is complicated by the fact that microglia are thought to be involved in developmental processes such as synaptic refinement and myelination, which underlie the functional maturation of multiple brain systems in adolescence. Thus, the role microglia play in the impact of alcohol use in adolescence is likely multifaceted. Long-term sequelae may be due to a failure to recover from EtOH-induced tissue damage, altered neurodevelopmental trajectories, and/or persistent changes to microglial responsivity and function. Here, we review critically the literature surrounding the effects of alcohol on microglia in models of adolescent alcohol misuse. We attempt to disentangle what is known about microglia from other neuroimmune effectors, to which we apply recent discoveries on the role of microglia in development and plasticity. Considered altogether, these studies challenge assumptions that proinflammatory microglia drive addiction. Alcohol priming microglia and thereby perturbing their homeostatic roles in neurodevelopment, especially during critical periods of plasticity such as adolescence, may have more serious implications for the neuropathogenesis of AUDs in adolescents.

The JAK-STAT1 transcriptional signature in peripheral immune cells reveals alterations related to illness duration and acuity in psychosis.

Multiple lines of inquiry demonstrate alterations to immune function in psychosis. Clinically, this is reflected by elevated proinflammatory cytokines in serum, indicating activation of circulating immune cells. Data from isolated cells in clinical populations support the presence of altered activity of pertinent intracellular signaling pathways. Here, we focus on the well-characterized IFN-γ mediated JAK-STAT1 signaling pathway, which is involved in multiple aspects of immunity, including activation of circulating immune cells to a proinflammatory phenotype. By measuring a transcriptional signature characteristic of activation of this pathway, we demonstrate that JAK-STAT1 signature gene expression is suppressed in participants with psychosis who are early in illness and in participants who are hospitalized with an acute exacerbation of psychosis. Furthermore, we find that this expression signature normalizes in participants who have a longer illness duration and chronic, but not acute, psychopathology. This relationship of JAK-STAT1 signature gene expression with clinical characteristics highlights the temporal and contextual complexity of alterations to immune activity in psychosis and provides important insight into the functional state of circulating immune cells. These findings are of particular interest given recent research illustrating the importance of peripherally derived immune cells and the effectors they secrete in mediating neurophysiological processes of relevance for psychiatric illness.

Immersion in altered experience: An investigation of the relationship between absorption and psychopathology.

Understanding alterations in perceptual experiences as a component of the basic symptom structure of psychosis may improve early detection and the identification of subtle shifts that can precede symptom onset or exacerbation. We explored the phenomenological construct of absorption and psychotic experiences in both clinical (bipolar psychosis and schizophrenia spectrum) and non-clinical participants. Participants with psychosis endorsed significantly higher absorption compared to the non-clinical group. Absorption was positively correlated with all types of hallucinations and multiple types of delusions. The analysis yielded two distinct cluster groups that demarcated a distinction along the continuum of self-disturbance: on characterized by attenuated ego boundaries and the other stable ego boundaries. The study suggests that absorption is a potentially important but under-researched component of psychosis that overlaps with, but is not identical to the more heavily theorized constructs of aberrant salience and hyperreflexivity.

Activated Phosphorylated STAT1 Levels as a Biologically Relevant Immune Signal in Schizophrenia.

OBJECTIVE: Activation of STAT1 is directly downstream of the cytokine receptors that signal from specific proinflammatory cytokines known to be dysregulated in schizophrenia (SZ), such as IFNγ, IL6, IL2 and IL10, as well as hypoxia, viral/bacterial infections and peptide growth factors. If the increased cytokine protein levels repeatedly observed in SZ have biological consequences, then the measurement of pSTAT1 is a logical step forward. METHODS: Peripheral blood mononuclear cells (PBMCs) from controls (n = 13) and subjects with SZ (n = 22) were extracted using the Ficoll method. Participants with SZ were diagnosed using the SCID, clinical symptomatology was measured using the Positive and Negative Syndrome Scale (PANSS), and cognitive functioning was measured using the MATRICS Consensus Cognitive Battery. Levels of activated STAT1 (Y701), i.e. phosphorylated STAT1 (pSTAT1), were measured by a commercially available ELISA in nuclear extracts from PBMCs. RESULTS: There was a significant bimodal distribution in the sample, with an SZ subgroup expressing significantly greater levels of activated pSTAT1 than the remainder of the participants. In this subgroup, levels of pSTAT1 were significantly higher than in the control group, as well as significantly higher than in the remainder of the SZ subjects. Furthermore, this subsample of patients manifested significantly poorer cognitive performance on several measures of the MATRICS. DISCUSSION: pSTAT1 levels may provide a measure of the biological relevance of widely reported elevations in levels of cytokines in SZ over the past several decades. Activation of kinase cascades can be used to partition or disassemble the composite immune signal in patients living with SZ.

Astrocyte Reactivity and Neurodegeneration in the Female Rat Brain Following Alcohol Dependence.

Recent evidence suggests that alcohol use disorder (AUD) may manifest itself differently in women compared to men. Women experience AUDs on an accelerated timeline and may have certain regional vulnerabilities. In male rats, neuronal cell death and astrocyte reactivity are noted following induction of alcohol dependence in an animal model of an AUD. However, the regional and temporal patterns of neurodegeneration and astrocyte reactivity have yet to be fully examined in females using this model. Therefore, adult female rats were exposed to a 4-day binge model of alcohol dependence followed by different periods of abstinence. Histological markers for FluoroJade B, a label of degenerating neurons, and vimentin, a marker for reactive astrocytes, were utilized. The expression of these markers in cortical and limbic regions was quantified immediately after their last dose (e.g., T0), or 2, 7, and 14 days later. Significant neuronal cell death was noted in the entorhinal cortex and the hippocampus, similar to previous reports in males, but also in several cortical regions not previously observed. Vimentin immunoreactivity was noted in the same regions as previously reported, in addition to three novel regions. Vimentin immunoreactivity also occurred at earlier and later time points in some cortical and hippocampal regions. These data suggest that both neuronal cell death and astrocyte reactivity could be more widespread in females compared to males. Therefore, this study provides a framework for specific regions and time points which should be examined in future studies of alcohol-induced damage that include female rats.

Adolescent Intermittent Ethanol Drives Modest Neuroinflammation but Does Not Escalate Drinking in Male Rats.

During adolescence, the brain is highly susceptible to alcohol-induced damage and subsequent neuroimmune responses, effects which may enhance development of an alcohol use disorder (AUD). Neuroimmune reactions are implicated in adolescent alcohol exposure escalating adulthood drinking. Therefore, we investigated whether intermittent alcohol exposure in male, adolescent rats (AIE) escalated adult drinking via two-bottle choice (2BC). We also examined the influence of housing environment across three groups: standard (group-housed with enrichment during 2BC), impoverished (group-housed without enrichment during 2BC), or isolation (single-housed without bedding or enrichment throughout). In the standard group immediately after AIE/saline and after 2BC, we also examined the expression of microglial marker, Iba1, reactive astrocyte marker, vimentin, and neuronal cell death dye, FluoroJade B (FJB). We did not observe an escalation of adulthood drinking following AIE, regardless of housing condition. Further, only a modest neuroimmune response occurred after AIE in the standard group: no significant microglial reactivity or neuronal cell death was apparent using this model, although some astrocyte reactivity was detected in adolescence following AIE that resolved by adulthood. These data suggest that the lack of neuroimmune response in adolescence in this model may underlie the lack of escalation of alcohol drinking, which could not be modified through isolation stress.

Monocyte Transcriptional Profiling Highlights a Shift in Immune Signatures Over the Course of Illness in Schizophrenia.

With advanced understanding of the intricate interplay between the immune and central nervous systems in neurological and neuropsychiatric illness, there is renewed interest in the potential contribution of immune dysregulation to the development and progression of schizophrenia. To inform this line of inquiry requires a more nuanced understanding of specific immune changes throughout the course of illness. Here, we utilized a genome-wide sequencing approach to transcriptionally profile circulating monocytes in participants with chronic schizophrenia. These myeloid cells, isolated from whole blood samples, are highly plastic with potentially important disease-modifying functions. Differential gene expression and gene set enrichment analyses, focusing on established monocyte phenotypic signatures, including those related to proinflammatory ("M1-like") and protective or tissue remodeling ("M2-like") functions, were carried out. We demonstrate an overall enrichment of both "M1-like" (interferon-alpha, interferon-gamma, lipopolysaccharide acute) and "M2-like" (endotoxin tolerance, glucocorticoid acute) monocyte signatures in the participants with schizophrenia compared to non-psychiatric controls. There was no enrichment of the "M1-like" chronic stress signature or the "M2-like" interleukin-4 signature. Using the Molecular Signatures Database Hallmark gene sets list, the "interferon response" was most strongly enriched in schizophrenia compared to controls. Additionally, an exploratory subgroup analysis based on illness duration suggests a shift in monocyte phenotype with illness progression. Specifically, the "M1-like" interferon-gamma signature shows decreased enrichment accompanied by increased enrichment of opposing "M2-like" signatures in participants with a medium illness duration shifting to a strong enrichment of interferon response signatures only in participants with a long illness duration. These findings related to circulating immune cell phenotype have potentially important implications for understanding the role of immune dysregulation in schizophrenia and are a critical consideration for future study design and immune-targeting treatment strategies.

The role of inner speech on the association between childhood adversity and 'hearing voices'.

Adverse childhood experiences are associated with later development of psychosis, particularly auditory verbal hallucinations and delusions. Although auditory hallucinations have been proposed to be misattributed inner speech, the relation between childhood adversity and inner speech has not been previously investigated. The first aim was to test whether childhood adversity is associated with inner speech in persons with psychosis. The second aim was to test for the influence of inner speech on the association between childhood adversity and auditory hallucinations. Our final aim was to test for evidence that would falsify the null hypothesis that inner speech does not impact the relationship between childhood adversity and delusions. In persons with psychosis, we found a positive association between childhood adversity and dialogic inner speech. There was a significant total effect of childhood adversity on auditory hallucinations, including an indirect effect of childhood adversity on auditory hallucinations via dialogic inner speech. There was also a significant total effect of childhood adversity on delusions, but no evidence of any indirect effect via inner speech. These findings suggest that childhood adversities are associated with inner speech and psychosis. The relation between childhood adversity and auditory hallucination severity could be partially influenced by dialogic inner speech.

Treatment with the antipsychotic risperidone is associated with increased M1-like JAK-STAT1 signature gene expression in PBMCs from participants with psychosis and THP-1 monocytes and macrophages.

Clinical studies demonstrate alterations to immune measures in psychosis that can vary with illness stage and severity. For example, recent data show that changes to the JAK-STAT1 transcriptional signature, characteristic of an "M1" proinflammatory monocyte and macrophages phenotype, are related to illness duration. While antipsychotics have demonstrated immunomodulatory properties, their effects on this important immune signaling pathway are unknown. The primary aims of this study were to determine the effects of risperidone, a commonly prescribed antipsychotic drug, on the JAK-STAT1 transcriptional signature. Selected measures of JAK-STAT1 signature gene expression in peripheral blood mononuclear cells (PBMCs) from a clinical sample with psychosis were compared to examine differences induced by risperidone treatment. Additionally, the direct effects of risperidone on the JAK-STAT1 signature were investigated using a THP-1 human monocyte and macrophage cell model. Comparisons within the clinical sample demonstrated that the JAK-STAT1 signature was elevated in PBMCs from participants treated with risperidone who had a longer illness duration compared to untreated participants and those who were risperidone treated but had a shorter illness duration. Results of the in-vitro experiments showed a consistent potentiating effect of risperidone on expression of JAK-STAT1 signature genes in activated monocytes and monocyte-derived macrophages. Collectively these data indicate that risperidone may skew myeloid cells to a more proinflammatory phenotype, potentially contributing to increases in expression of JAK-STAT1 signature genes in participants with a longer illness duration.

Its complicated: The relationship between alcohol and microglia in the search for novel pharmacotherapeutic targets for alcohol use disorders.

Alcohol use disorder (AUD) is a chronic relapsing disorder with wide-ranging health consequences. Alcohol targets the central nervous system producing neurodegeneration and subsequent cognitive and behavioral deficits, but the mechanisms behind these effects remain unclear. Recently, evidence has been mounting for the role of neuroimmune activation in the pathogenesis of AUDs, but our nascent state of knowledge about the interaction of alcohol with the neuroimmune system supports that the relationship is complicated. As the resident macrophage of the central nervous system, microglia are a central focus. Human and animal research on the interplay between microglia and alcohol in AUDs has proven to be complex, and though early research focused on a pro-inflammatory phenotype of microglia, the anti-inflammatory and homeostatic roles of microglia must be considered. How these new roles for microglia should be incorporated into our thinking about the neuroimmune system in AUDs is discussed in the context of developing novel pharmacotherapies for AUDs.

Traumagenics: At the intersect of childhood trauma, immunity and psychosis.

Early childhood trauma, including physical, sexual or emotional abuse, neglect, harm or threat of harm, is associated with adulthood dysregulation of the immune system. Trauma can induce chronic immune system activation. Associations between a chronic pro-inflammatory state and schizophrenia are an enduring finding of psychiatry, with elevated cytokine concentrations correlated with psychotic symptom severity. Most importantly, persons with schizophrenia and a history of childhood trauma demonstrate increased cytokine levels. Specific types of childhood trauma can also differentially impact the expression of unique immune markers. This study tested the hypotheses that levels of adverse childhood experiences (ACEs) would be associated with levels of peripheral immune activity assessed by IL6, IFNG, CXCL10, IRF1, STAT1 and TLR4 mRNA expression, and that there would be an association between ACEs and psychosis along a continuum from non-clinical controls (NCC) to psychotic disorders such as schizophrenia. These hypotheses were tested in 20 schizophrenia, 20 NCC. We found correlations between ACEs scores and immune markers, specifically IL6. We also found a positive association between ACEs and positive symptoms. Childhood trauma, through its effects on IL6, may be a risk factor for schizophrenia.

Long non-coding and endogenous retroviral RNA levels are associated with proinflammatory cytokine mRNA expression in peripheral blood cells: Implications for schizophrenia.

Recent research indicates that the expression of long non-coding and endogenous retroviral RNAs is coordinated with the activity of immune molecules often dysregulated in schizophrenia. We measured the expression of TMEVPG1, NRON, HERV-W env and HERV-W gag in blood cells from participants with schizophrenia and controls. We report that a) expression levels of these non-coding RNAs are correlated with proinflammatory cytokine mRNA expression in all participants, b) HERV-W transcripts are negatively correlated with atypical antipsychotic use in participants with schizophrenia, and c) that these RNAs are transcribed in response to proinflammatory stimuli in a THP-1 monocyte cell line.

C4A mRNA expression in PBMCs predicts the presence and severity of delusions in schizophrenia and bipolar disorder with psychosis.

Altered immune function is an established finding in psychotic disorders such as schizophrenia and bipolar disorder with psychosis, though its role in their development and progression remains to be understood. Evidence suggests altered JAK-STAT1 pathway activity in peripheral blood cells from participants with schizophrenia compared to controls. Activation of this pathway leads to increased expression of complement component 4A (C4A), which has recently been implicated in schizophrenia. Here, we examine mRNA expression of C4A in peripheral blood cells from participants with schizophrenia, bipolar disorder and controls. STAT1 and IRF-1 mRNA expression are included as measures of JAK-STAT1 pathway activation in the same participants. Further, we examine the association of each genes mRNA expression with clinical symptom measures using the Positive and Negative Syndrome Scale (PANSS) and the Psychotic Symptom Rating Scale (PSYRATS). We demonstrate that C4A, STAT1 and IRF-1 mRNA expression levels are correlated across the entire sample, indicating shared transcriptional regulatory mechanisms. Further, we show that C4A mRNA expression alone is positively associated with psychotic symptomatology, specifically the presence and severity of delusions. These findings are noteworthy given recent findings that demonstrate a critical role for complement proteins in synaptic pruning, alterations of which are proposed to contribute to psychopathology in psychosis.

Long Non-Coding RNAs Associated with Heterochromatin Function in Immune Cells in Psychosis.

Psychosis is associated with chronic immune dysregulation. Many long non-coding RNAs (lncRNAs) display abnormal expression during activation of immune responses, and play a role in heterochromatic regulation of gene promoters. We have measured lncRNAs MEG3, PINT and GAS5, selected for their previously described association with heterochromatin. Peripheral blood mononuclear cells (PBMCs) were isolated from blood samples collected from 86 participants with a diagnosis of psychosis and 44 control participants. Expression was assessed in relation to diagnosis, illness acuity status, and treatment with antipsychotic medication. We observed diagnostic differences with MEG3, PINT and GAS5, and symptom acuity effect with MEG3 and GAS5. Medication effects were evident in those currently on treatment with antipsychotics when compared to drug-naïve participants. We observed that clinical diagnosis and symptom acuity predict selected lncRNA expression. Particular noteworthy is the differential expression of MEG3 in drug naïve participants compared to those treated with risperidone. Additionally, an in vitro cell model using M2tol macrophages was used to test the effects of the antipsychotic drug risperidone on the expression of these lncRNAs using quantitative real-time PCR (qRT-PCR). Significant but differential effects of risperidone were observed in M2tol macrophages indicating a clear ability of antipsychotic medications to modify lncRNA expression.

The tangled roots of inner speech, voices and delusions.

The role of inner speech in the experience of auditory verbal hallucinations (AVH) and delusions remains unclear. This exploratory study tested for differences in inner speech (assessed via self-report questionnaire) between 89 participants with psychosis and 37 non-clinical controls. We also tested for associations of inner speech with, i) state/trait AVH, ii) AVH-severity; iii) patients' relations with their voices, and; iv) delusion-severity. Persons with psychosis had greater levels of dialogic inner speech, other people in inner speech, and evaluative/motivational inner speech than non-clinical controls. Those with state, but not trait AVH had greater levels of dialogic and evaluative/motivational inner speech than non-clinical controls. After controlling for delusions, there was a positive relation between AVH-severity and both evaluative/motivational inner speech and other people in inner speech. Participants with greater levels of dialogic inner speech reported better relations both with and between their voices. There was no association between delusion-severity and inner speech. These results highlight the importance of better understanding relations between inner speech and AVH, provide avenues for future research, and underscore the need for research into the interrelatedness of inner speech, voices and delusions, and the complexities involved in disentangling these experiences.

Exploring the Intersections of Trauma, Structural Adversity, and Psychosis among a Primarily African-American Sample: A Mixed-Methods Analysis.

Traumatic life events (TLEs) have been associated with multiple psychiatric diagnoses, including anxiety disorders, major depression, PTSD, and psychosis. To advance our understanding of the complex interactions between forms of adversity as they manifest across the lifespan, psychosis, and symptom content, we undertook a mixed-methods investigation of TLEs and psychosis. Our research explored the association between cumulative exposures, type of TLE, and proximity to the traumatic event and psychosis; the association between TLEs and clinical symptomology including specific types of delusions and/or hallucinations; and how qualitative data further inform understanding of complex relationships and patterns of past trauma and symptoms as they unfold over time. There were a total of 97 participants in the quantitative study sample, 51 participants with present state psychosis and 46 non-clinical. There were a total of 34 qualitative study participants, all of whom were experiencing psychosis. The quantitative analysis showed that when comparing persons with psychosis to the non-clinical group, there were no group differences in the overall total score of TLEs. However, there was a significant difference in cumulative TLEs that "Happened," demonstrating that as the number of TLEs increased, the likelihood of clinical psychosis also increased. We also found a correlation between lifetime cumulative TLEs that "Happened" and PANSS five-factor analysis: positive, excitement, depression, thought disorder, activation, and paranoia scores. The qualitative analysis further built on these finding by providing rich narratives regarding the timing of trauma-related onset, relationships between trauma and both trauma-related and religious-spiritual content, and trauma and hallucinatory modality. Analysis of participant narratives suggests the central role of localized cultural and sociopolitical influences on onset, phenomenology, and coping and contributes to a growing literature calling for strengths-based, client-driven approaches to working with distressing voices and beliefs that centers the exploration of the personal and social meaning of such experiences including links to life narratives. Findings also underscore the clinical importance of trauma assessment and trauma-informed care.