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Adolescence is a key phase of development for perturbations in fear extinction, with inability to adequately manage fear a potent factor for developing psychiatric disorders in adulthood. However, while behavioral correlates of adolescent fear regulation are established to a degree, molecular mediators of extinction learning in adolescence remain largely unknown. In this study, we observed fear acquisition and fear extinction (across 4 and 7 days) of adolescent and adult mice of both sexes and investigated how hippocampal levels of different plasticity markers relate to extinction learning. While fear was acquired evenly in males and females of both ages, fear extinction was found to be impaired in adolescent males. We also observed lower levels of GluA1, GLUN2A and GLUN2B subunits in male adolescents following fear acquisition, with an increase in their expression, as well as the activity of Erk-mTOR pathway over subsequent extinction sessions, which was paralleled with improved extinction learning. On the other hand, we detected no changes in plasticity-related proteins after fear acquisition in females, with alterations in GluA1, GluA4 and GLUN2B levels across fear extinction sessions. Additionally, we did not discern any pattern regarding the Erk-mTOR activity in female mice associated with their extinction performance. Overall, our research identifies sex-specific synaptic properties in the hippocampus that underlie developmentally regulated differences in fear extinction learning. We also point out hippocampal NMDA-Erk-mTOR signaling as the driving force behind successful fear extinction in male adolescents, highlighting this pathway as a potential therapeutic target for fear-related disorders in the adolescent population. © 2022 The Authors

Adolescent stress predisposes individuals to increased risk for anxiety and depression in adulthood. The stress response is mediated by the glucocorticoid receptor (GR) via regulation of GR-responsive genes involved in brain reaction to stress. Although dysregulation of GR in depression is well documented, this is the first study investigating the role of GRα isoforms in pathogenesis of depression. We exposed adolescent male and female C57BL/6J mice to chronic unpredictable stress (CUS) for 12 days starting at postnatal day 28 (PND28). Tests evaluating anxiety and depressive-like behaviors were performed at PND70. We analyzed corticosterone concentrations in serum, levels of GRα isoforms (95, 67, 50, 40, and 25 kDa), and mRNA levels of GR-responsive genes (GR, FKBP5, BDNF, and IL-1β) in the hippocampus and the prefrontal cortex (PFC). CUS increased anxiety and depressive-like behavior in adult animals of both sexes, but did not affect corticosterone serum levels, 95 and 67 kDa GR isoforms. However, the levels of shorter GRα isoforms (50, 40, and 25 kDa) were altered in adult mice underwent CUS, in sex- and brain structure–specific way. Changes in gene expression revealed that female depressive-like behavior could be related to increased levels of IL-1β in hippocampus and reduced BDNF levels in both hippocampus and PFC. However, in males, adolescent CUS increased expression of GR in adult hippocampus and BDNF in PFC. These findings suggest that adolescent stress altered levels of GRα isoforms, especially those with lower molecular weight, in sex- and tissue-specific ways, contributing to anxiety and depression in adult mice.

To adapt to the sustained demands of chronic stress, discrete brain circuits undergo structural and functional changes often resulting in anxiety disorders. In some individuals, anxiety disorders precede the development of motor symptoms of Parkinson's disease (PD) caused by degeneration of neurons in the substantia nigra (SN). Here, we present a circuit framework for probing a causal link between chronic stress, anxiety, and PD, which postulates a central role of abnormal neuromodulation of the SN's axon initial segment by brainstem inputs. It is grounded in findings demonstrating that the earliest PD pathologies occur in the stress-responsive, emotion regulation network of the brainstem, which provides the SN with dense aminergic and cholinergic innervation. SN's axon initial segment (AIS) has unique features that support the sustained and bidirectional propagation of activity in response to synaptic inputs. It is therefore, especially sensitive to circuit-mediated stress-induced imbalance of neuromodulation, and thus a plausible initiating site of neurodegeneration. This could explain why, although secondary to pathophysiologies in other brainstem nuclei, SN degeneration is the most extensive. Consequently, the cardinal symptom of PD, severe motor deficits, arise from degeneration of the nigrostriatal pathway rather than other brainstem nuclei. Understanding when and how circuit dysfunctions underlying anxiety can progress to neurodegeneration, raises the prospect of timed interventions for reversing, or at least impeding, the early pathophysiologies that lead to PD and possibly other neurodegenerative disorders. Chapter 32

Fear-related disorders, mainly phobias and post-traumatic stress disorder, are highly prevalent, debilitating disorders that pose a significant public health problem. They are characterized by aberrant processing of aversive experiences and dysregulated fear extinction, leading to excessive expression of fear and diminished quality of life. The gold standard for treating fear-related disorders is extinction-based exposure therapy (ET), shown to be ineffective for up to 35% of subjects. Moreover, ET combined with traditional pharmacological treatments for fear-related disorders, such as selective serotonin reuptake inhibitors, offers no further advantage to patients. This prompted the search for ways to improve ET outcomes, with current research focused on pharmacological agents that can augment ET by strengthening fear extinction learning. Hallucinogenic drugs promote reprocessing of fear-imbued memories and induce positive mood and openness, relieving anxiety and enabling the necessary emotional engagement during psychotherapeutic interventions. Mechanistically, hallucinogens induce dynamic structural and functional neuroplastic changes across the fear extinction circuitry and temper amygdala's hyperreactivity to threat-related stimuli, effectively mitigating one of the hallmarks of fear-related disorders. This paper provides the first comprehensive review of hallucinogens' potential to alleviate symptoms of fear-related disorders by focusing on their effects on fear extinction and the underlying molecular mechanisms. We overview both preclinical and clinical studies and emphasize the advantages of hallucinogenic drugs over current first-line treatments. We highlight 3,4-methylenedioxymethamphetamine and ketamine as the most effective therapeutics for fear-related disorders and discuss the potential molecular mechanisms responsible for their potency with implications for improving hallucinogen-assisted psychotherapy.

Inflammation plays a key role in the pathogenesis of the major depressive disorder. Namely, neuroinflammation can induce the production of neuroactive metabolites that interfere with N-methyl-D-aspartate receptors (NMDAR)-mediated glutamatergic neurotransmission and contribute to depressive-like behaviour. On the other hand, mammalian target of rapamycin (mTOR) activity with synaptogenic effects is the main mediator of antidepressant effects of several potent NMDAR antagonists. In this study, we investigated the specific role of GluN2A subunits of NMDAR on the activity of mTOR signaling and behaviour in lipopolysaccharide (LPS)-induces model of depression. The results showed that mice lacking GluN2A subunit did not display depressive-like behavior after the immune challenge, opposite to LPS-treated wild-type mice. Specifically, in GluN2A knockout mice, we estimated the activity of the mTOR pathway in the hippocampus and prefrontal cortex (PFC) by measuring synaptic levels of upstream regulators (p-Akt, p-ERK, and p-GSK3β) and downstream effectors (p-mTOR, and p-p70S6K) of mTOR activity. In addition, we assessed the changes in the levels of two important synaptic markers, GluA1 and PSD-95. Contrary to downregulated mTOR signaling and decreased synaptic markers in LPS-treated wild-type animals, the resilience of GluN2A KO mice to depressive-like behaviour was paralleled with sustained mTOR signaling activity synaptic stability in hippocampus and PFC. Finally, we disclosed that resistance of GluN2A knockouts to LPS-induced depressive-like behavior was ERK-dependent. These findings demonstrate that GluN2A-ERK-mTOR signaling is a vulnerability factor of inflammation-related depressive behaviour, making this signaling pathway the promising target for developing novel antidepressants.

Childhood trauma (CT) increases the risk for psychopathology through disturbed acquisition and extinction of fear. The effects of CT are mediated by abnormalities of the hypothalamic-pituitary-adrenal axis and glucocorticoid receptor (GR). Since, the alterations in GRα translational isoforms have been documented in psychiatric disorders we sought to: 1) explore whether multiple GRα isoforms in the human peripheral blood mononuclear cells of two independent cohorts (whole cell n = 40; and nuclear extracts n = 43, adult subjects) mediate the effect of CT on negative affectivity (NA) measured by Depression, Anxiety and Stress Scales (DASS), and 2) examine their role/function during fear extinction in the animal model. In multiple regression analysis, CT, nuclear 40-kDa GRα their interactions and FKBP5 explained 22%–35% of variance in DASS scores. Structural equation modeling showed that CT had a significant direct effect on 40-kDa and DASS in both cohorts, and on the nuclear 25-kDa GRα. The association between 40-kDa and total DASS was significantly mediated by nuclear FKBP5, whereas on DASS anxiety, over FKBP5 in both cohorts and nuclear full length GRα. Nuclear 40-kDa GRα and its interaction with CT had a significant direct effect on DASS anxiety. In mice, the successful extinction learning was followed by nuclear translocation of 40-kDa GRα and induction of BDNF exon IV expression. Our data revealed that the association between CT and adult NA in non-clinical subjects is mediated by the GRα translational isoforms, in particular 40-kDa GRα and emphasized its role in fear extinction and neural plasticity. © 2018 Elsevier Inc. Free Author Manuscript available at PMC: [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6383671/]

The brain is the softest organ in the body, and any change in the mechanical properties of the tissue induces the activation of glial cells, astrocytes and microglia. Amyloid plaques, one of the main pathological features of Alzheimer's disease (AD), are substantially harder than the surrounding brain tissue and can activate astrocytes and microglia resulting in the glial engulfment of plaques. Durotaxis, a migratory preference towards stiffer tissue, is prompting microglia to form a mechanical barrier around plaques reducing amyloid β (Aβ) induced neurotoxicity. Mechanoreceptors are highly expressed in the brain, particularly in microglia. The large increase in the expression of the mechanoreceptor Piezo1 was observed in the brains from AD animal models and AD patients in plaque encompassing glia. Importantly, Piezo1 function is regulated via force-from-lipids through the lipid composition of the membrane and membranous incorporation of polyunsaturated fatty acids (PUFAs) can affect the function of Piezo1 altering mechanosensitive properties of the cell. On the other hand, PUFAs dietary supplementation can alter microglial polarization, the envelopment of amyloid plaques, and immune response and Piezo1 activity was implicated in the similar modulations of microglia behavior. Finally, PUFAs treatment is currently in use in medical trials as the therapy for sickle cell anemia, a disease linked with the mutations in Piezo1. Further studies are needed to elucidate the connection between PUFAs, Piezo1 expression, and microglia behavior in the AD brain. These findings could open new possibilities in harnessing microglia in AD and in developing novel therapeutic strategies.

Hypothalamic–pituitary–adrenal (HPA) axis activity mediates the relationship between childhood trauma (CT) and psychosis. The FKBP5 gene, one of the key regulators of HPA axis activity after stress exposure, has been found associated with psychosis. Allele-specific and CT related FKBP5 demethylation in intron 7 was revealed in different psychiatric disorders. However, no studies have investigated FKBP5 methylation in subjects with different genetic liability for psychosis. A total of 144 participants were included in the study: 48 patients with psychotic disorders, 50 unaffected siblings, and 46 healthy controls. CT was assessed by Childhood Trauma Questionnaire. The FKBP5 rs1360780 was genotyped and FKBP5 methylation analyses were performed using bisulfite conversion followed by Sanger sequencing at three CpG sites in intron 7. Mixed linear model was used to assess group differences depending on rs1360780 T allele and CT. Results showed a significant T allele-dependent decrease of FKBP5 methylation in patients compared to unaffected siblings and controls. Effect of interaction between T allele and CT exposure on FKBP5 demethylation was found in controls. No effect of both risk factors (T allele and CT) on FKBP5 methylation level was found in unaffected siblings. We confirmed previous evidence of the association between the FKBP5 rs1360780 T allele, CT, and decreased FKBP5 methylation in intron 7. Allele-specific FKBP5 demethylation found in patients could shed a light on altered HPA axis activity in a subgroup of patients related to stress-induced psychosis. FKBP5 methylation and potential protective mechanisms in unaffected siblings after trauma exposure require further investigation. © 2021 Elsevier Ltd

The SARS-CoV-2 outbreak caused an unprecedented global public health threat, having a high transmission rate with currently no drugs or vaccines approved. An alternative powerful additional approach to counteract COVID-19 is in silico drug repurposing. The SARS-CoV-2 main protease is essential for viral replication and an attractive drug target. In this study, we used the virtual screening (VS) protocol with both long-range and short-range interactions to select candidate SARS-CoV-2 main protease inhibitors. First, the ISM applied for Small Molecules was used for searching the Drugbank database and further followed by molecular docking. After in silico screening of drug space, we identified 57 drugs as potential SARS-CoV-2 main protease inhibitors that we propose for further experimental testing.

Mitochondria play a significant role in pathogenesis of clinical depression and their function can be impaired by inflammation and alterations in hypothalamic–pituitary–adrenal axis. Sexual context is also a relevant factor in the incidence of mood disorders, and could have a strong influence during an immune challenge. Therefore, in this study we investigated whether the effects of seven-day lipopolysaccharide (LPS) treatment on glucocorticoid receptor (GR) could be associated with apoptosis and alterations in energy metabolism in hippocampus of female and male Wistar rats with depressive-like behavior. To that end, we measured the mitochondrial levels of GR and its phosphoisoforms pGR232 and pGR246 in hippocampus of female and male rats, as well as the mRNA levels of two GR-regulated mitochondrial genes, cyclooxygenase -1 and -3 (COX-1 and -3). We also measured alterations in the extrinsic and intrinsic apoptotic pathways in mitochondria and cytosol of hippocampus of these animals, and the levels of cleaved cytosolic poly [ADP-ribose] polymerase-1 (PARP-1) protein. We discovered that even though LPS treatment induced behavioral alterations and affected corticosterone levels and apoptosis in a similar manner in both sexes, it affected mitochondrial GR differently in males and females. Namely, the treatment decreased levels of mitochondrial GR and pGR232/pGR246 ratio only in females, and these alterations were followed by decreased mRNA levels of COX-1 and COX-3 only in this sex. The alterations in COX-1 and COX-3 mRNA levels could indicate impaired oxidative metabolism and diminished mitochondrial function in hippocampus of this sex. © 2020 IBRO

Accumulating evidence strongly suggest that impaired glucocorticoid receptor (GR) signaling is involved in stress-related mood disorders, and nominate GR as a potential target for antidepressants (ADs). It is known that different classes of ADs affects the GR action via modifying its phosphorylation, while the mechanism through which ADs alter GR phosphorylation targeted by GSK3 beta, a kinase modulated via serotonin neurotransmission, are unclear. On this basis, we investigated whether GSK3 beta-GR signaling could be a convergence point of fluoxetine action on brain function and behavior, by examining its effect on GSK3 beta targeted-GR phosphorylation on threonine 171 (pGR171), and expression of GR-regulated genes in the hippocampus of female and male rats exposed to chronic isolation stress. Stress induced sex-specific GSK3 beta-targeted phosphorylation of pGR171 in the nucleus of the hippocampus of stressed animals. Namely, while in females stress triggered coupled action of GSK3 beta-pGR171 signaling, in males changes in pGR171 levels did not correspond to GSK3 beta activity. On the other hand, fluoxetine managed to up regulate this pathway in sex-unbiased manner. Furthermore, fluoxetine reverted stress-induced changes in most of the analyzed genes in males, CRH, 5-HT1a and p11, while in females its effect was limited to CRH. These data further suggest that pGR171 signaling affects cellular localization of GR in response to chronic stress and fluoxetine in both sexes. Collectively, our results describe a novel convergence point between GR signaling and GSK3 beta pathway in rat hippocampus in response to stress and fluoxetine in both sexes and its involvement in fluoxetine-regulated brain function in males.

Mitochondrial dysfunction can result from the interplay between elevated inflammatory markers and alterations in hypothalamic–pituitary–adrenal (HPA) axis, and can contribute to pathogenesis of major depression. Therefore, in this study we investigated whether the effects of lipopolysaccharide (LPS) on glucocorticoid receptor (GR) could be associated with alterations in mitochondrial apoptotic signaling in the prefrontal cortex of male and female Wistar rats with depressive-like behavior. To that end, we measured LPS-induced alterations in the extrinsic and intrinsic apoptotic pathways in mitochondria and cytosol of PFC of female and male rats, as well as the levels of cleaved cytosolic PARP-1. We also measured the mitochondrial levels of GR and its phosphoisoforms pGR232 and pGR246, as well as the mRNA levels of two GR-regulated mitochondrial genes, COX-1 and COX-3. We discovered that although seven-day LPS treatment evoked depressive-like behavior and induced apoptosis in the PFC of both sexes, it affected apoptotic cascades in both sexes differently. In females the treatment initiated both intrinsic and extrinsic apoptotic cascade, while in males only intrinsic cascade was engaged. Alterations in intrinsic apoptotic pathway were more associated with GR alterations in males, where LPS treatment decreased levels of mitochondrial GR and increased pGR232/pGR246 ratio. Alterations in mitochondrial GR could be associated with changes in expression of genes involved in oxidative metabolism in the PFC of this sex, and could, in combination with elevated levels of BCL-2 and decreased levels of BAX detected in this cell fraction, mitigate the detrimental effect of LPS on mitochondria in male PFC.

In 2012, alcohol liver disease resulted in 3.3 million—5.9% of global deaths. This study introduced whey protection capacity against chronic alcohol-induced liver injury. Rats were orally administered to 12% ethanol solution in water (ad libitum, average 8.14 g of ethanol/kg body weight (b.w.)/day) alone or combined with whey (per os, 2 g/kg b.w./day). After 6-week treatment, chronic ethanol consumption induced significant histopathological liver changes: congestion, central vein dilation, hepatic portal vein branch dilation, Kupffer cells hyperplasia, fatty liver changes, and hepatocytes focal necrosis. Ethanol significantly increased liver catalase activity and glutathione reductase protein expression without significant effects on antioxidative enzymes: glutathione peroxidase (GPx), copper–zinc-containing superoxide dismutase (CuZnSOD) and manganese-containing superoxide dismutase (MnSOD). Co-treatment with whey significantly attenuated pathohistological changes induced by ethanol ingestion and increased GSH-Px and nuclear factor kappa B (NF-κB) protein expression. Our results showed positive effects of whey on liver chronically exposed to ethanol, which seem to be associated with NF-κB-GPx signaling. © The Author(s) 2019.

Recent reports have demonstrated that lipopolysaccharide (LPS)-induced depressive-like behaviour is mediated via NMDA receptor. In this study, we further investigated the role of GluN2 A subunit of NMDA receptor in synaptic processes in the prefrontal cortex (PFC) and hippocampus of GluN2 A knockout (KO) mice in LPS-induced depressive-like behavior. Our data suggest that LPS-treated mice, lacking GluN2 A subunit, did not exhibit depressive-like behaviour. This was accompanied by unaltered levels of IL-6 and significant changes in neuroplasticity markers and glutamate receptor subunits composition in PFC and hippocampus. In particular, an immune challenge in GluN2 A KO mice resulted in unchanged PSA-NCAM levels and proBDNF increase in both brain structures as well as in increase in BDNF levels in hippocampus. Furthermore, the absence of GluN2 A resulted in increased levels of all NCAM isoforms in PFC upon LPS which was followed with a decrease in GluN1 and GluN2B subunits. The levels of AMPA receptor subunits (GluA1, GluA3, and GluA4) in the hippocampus of GluN2 A mice were unaltered upon the treatment and abundantly present in the PFC of KO mice. These results indicate that the GluN2 A subunit is critical in neuroinflammation-related depression, that its absence abolishes LPS-induced depressive phenotype, sustains PSA-NCAM levels, increases proBDNF signalling in the PFC and hippocampus and potentiates synaptic stabilization through NCAM in the PFC upon an immune challenge. © 2018 Elsevier B.V.

Preclinical Research Mitochondria are cell organelles crucial to the production of cellular energy. Several lines of evidence have indicated that mitochondrial dysfunction could be related to the pathophysiology of CNS diseases including bipolar disorder, major depressive disorder, and schizophrenia. These changes include impaired energy metabolism in the brain, co-morbidity with mitochondrial diseases, the effects of psychotropics on mitochondrial function, increased mitochondrial DNA (mtDNA) deletion in the brain, and association with mtDNA polymorphisms. Additionally, psychotropic drug treatments can alter energy metabolism and may affect mitochondrial processes. This review focuses on recent findings regarding the effects of antidepressants on mitochondrial processes in psychiatric disorders. Drug Dev Res 77 : 400-406, 2016. © 2016 Wiley Periodicals, Inc.

Objectives. To develop a structural equation model of negative affectivity (NA) that involves interaction of glucocorticoid receptor (GR) signaling, personality dimensions and recent stressful life events. Methods. Seventy participants -35 diagnosed with major depression and 35 healthy controls, were enrolled in the study. Morning plasma cortisol levels were determined by chemiluminescent immunometric assays. Molecular parameters (total nuclear and cytoplasmatic GR, nuclear GR phosphorylated at serine 211 (pGR-211) and at serine 226 (pGR-226) and cytoplasmic FKBP51) were analysed from peripheral blood lymphocytes by Western blot. NA, personality dimensions and stressful life events were assessed by self-report instruments. Results. GR signalling parameters had direct independent effect on measures of NA, with pGR-226 levels showing the strongest correlation, followed by FKBP51 and pGR-211 levels. Neuroticism and extraversion also demonstrated strong independent effect on NA, while recent stressful events did not predict NA directly, but demonstrated a significant effect on personality dimensions. Cortisol, total nuclear GR and total cytoplasmatic GR levels were excluded from the model due to non-significant correlations with NA. Conclusions. Negative affectivity is a transdiagnostic factor in vulnerability to affective disorders and possible therapeutic target. Molecular signature of negative affectivity should incorporate GR phosphorylation with other known biological underpinnings.

The early postnatal environment is critical for its capacity to influence adult behavior, and is associated with traits of altered physiological and neurobiological function and long-term predisposition to depression. Here we describe the delayed effects of maternal deprivation (MD) in male and female Wistar pups on their physical development and behavior in adulthood in tasks designed to explore depressive-like (forced swimming test, FST), and anxiety-like behaviors (elevated plus maze, EPM). We observed that MD led to reduced body weight in adulthood, anxiety-like traits in the EPM test and increased activity in the phases of the FST. Particularly, a consistent sexual dimorphism was observed in the responses to MD. A lower increase in body weight during maturation of MD rats was more pronounced in males than in females. MD anxiogenic effects were more pronounced in females, while in FST only MD males showed a marked increase in swimming activity followed by decreased immobility. [Projekat Ministarstva nauke Republike Srbije, br. III41029]

Considerable evidence shows an association of depression with the immune system and emphasizes the importance of gender in the etiology of the disease and the response to inflammatory stimuli. We examined the influence of immune-challenged systems on depressive-like behavior in female rats in the context of gonadal hormones. We used a neuroinflammatory model of depression elicited by lipopolysaccharide (LPS) administration on naive and ovariectomized (OVX) female rats, and examined the effects of estradiol (E2) and/or progesterone (P4) replacement therapy on animal behavior, as assessed by the forced swimming test (FST). We found that LPS and OVX increase immobility in the FST, while LPS also decreased body weight in naive female rats. Further, even though P4 application alone showed beneficial effects on the behavioral profile (it reduced immobility and increased climbing), supplementation of both hormones (E2 and P4) together to OVX rats failed to do so. When OVX rats were exposed to LPS-induced immune challenge, neither hormone individually nor their combination had any effect on immobility, however, their joint supplementation increased climbing behavior. In conclusion, our study confirmed that both LPS and OVX induced depressive-like behavior in female rats. Furthermore, our results potentiate P4 supplementation in relieving the depressive-like symptomatology in OVX rats, most likely through fine-tuning of different neurotransmitter systems. In the context of an activated immune system, the application of E2 and/or P4 does not provide any advantageous effects on depressive-like behavior.

Background: Epigenetic changes of the FKBP5 locus in adults were reported to be allele specific and trauma related in different patient populations. However, DNA methylation status of FKBP5 and its relation to the circulating protein levels are still unknown in schizophrenia spectrum disorders.

Depression is a disease of an abnormal brain energy metabolism also marked with increased apoptosis in specific brain regions. Mounting evidence indicates that the mitochondrial oxidative phosphorylation and apoptosis are novel targets for the actions of estrogen receptors (ERs). In this study, we examined the effects of antidepressant (AD) fluoxetine (FLU) treatment on the mitochondria] ER alpha (ER alpha), ER beta (total and phospho-pER(beta) and their association with cytochrome c (cyt oxidase activity and apoptotic Bcl2/Bax-molecules in the hippocampal mitochondria of chronically isolated (CPSI) female and male rats depicting depression. Impaired behaviour induced by CPSI was followed by decreased corticosterone (CORT) in both sexes and downregulation of cyt c oxidase in males. CPSI did not affect the ERa in either of sexes, but it decreased mitochondrial ER beta and increased pER beta in both sexes. Stress-reduced ER beta is associated with a decrease in mitochondrial energetic processes in males and with apoptotic mechanisms in females. FLU normalized behaviour in both sexes and increased cyt c oxidase in females. FLU elevated ERa in males, increased ER beta and decreased pERB in both sexes. The AD-induced alterations of ER beta paralleled with bioenergetics and pro-survival pathways in females. In conclusion, sex-unspecific regulation of ER beta by the stress and by AD and its differential convergence with bioenergetics and apoptotic pathways in females and males implies its role as a vulnerability factor in the stress response and emphasizes mitochondrial ER beta-dependent pathways as an important gateway of ADs action, at least in females. (C) 2017 Elsevier B.V. All rights reserved.

Inflammation plays a critical role in pathogenesis of depression and can affect the hypothalamic-pituitary-adrenal axis activity. Accordingly, in this study we investigated the role of hippocampal glucocorticoid receptor in mediating the effects of inflammation on behaviour of female and male Wistar rats. We studied the effects of lipopolysaccharide on the levels of glucocorticoid receptors and its co-chaperones FK506 binding protein 52 and FK506 binding protein 51, the levels of glucocorticoid receptor phospho-isoforms, pGR-232 and pGR-246, and glucocorticoid receptor up-stream kinases. In order to assess transcriptional activity of glucocorticoid receptor, we measured mRNA levels of several glucocorticoid receptor-regulated genes. We demonstrated that lipopolysaccharide induced depressive-like behaviour and elevated serum corticosterone in both sexes. However, it affected glucocorticoid receptor signalling in the nucleus of females and males differently - in females it elevated levels of glucocorticoid receptors, pGR-246 and FK506 binding protein 52, while in males it decreased levels of glucocorticoid receptor, both co-chaperons and pGR-246. Alterations in pGR-246 were associated with alterations of c-Jun N-terminal kinases. Altered nuclear levels of total glucocorticoid receptors and pGR-246 were accompanied by sex-specific reduction in brain-derived neurotrophic factor and cyclooxygenase-2 mRNA and sex-unspecific reduction in the expression of p11 and glucocorticoid receptor genes. These alterations may ultimately affect different glucocorticoid receptor -associated processes involved in depressive-like behaviour in males and females.

Background Mounting evidence demonstrates enhanced systemic levels of inflammatory mediators in depression, indicating that inflammation may play a role in the etiology and course of mood disorders. Indeed, proinflammatory cytokines induce a behavioral state of conservation- withdrawal resembling human depression, characterized by negative mood, fatigue, anhedonia, psychomotor retardation, loss of appetite, and cognitive deficits. Neuroinflammation also contributes to non-responsiveness to current antidepressant (AD) therapies. Namely, response to conventional AD medications is associated with a decrease in inflammatory biomarkers, whereas resistance to treatment is accompanied by increased inflammation. Methods In this review, we will discuss the utility and shortcomings of pharmacologic AD treatment strategies focused on inflammatory pathways, applied alone or as an adjuvant component to current AD therapies. Results Mechanisms of cytokine actions on behavior involve activation of inflammatory pathways in the brain, resulting in changes of neurotransmitter metabolism, neuroendocrine function, and neuronal plasticity. Selective serotonin reuptake inhibitors exhibit the most beneficial effects in restraining the inflammation markers in depression. Different anti-inflammatory agents exhibit AD effects via modulating neurotransmitter systems, neuroplasticity markers and glucocorticoid receptor signaling. Anti-inflammatory add-on therapy in depression highlights such treatment as a candidate for enhancement strategy in patients with moderate-to-severe depression. Conclusion The interactions between the immune system and CNS are not only involved in shaping behavior, but also in responding to therapeutics. Even though, substantial evidence from animal and human research support a beneficial effect of anti-inflammatory add-on therapy in depression, further research with special attention on safety, particularly during prolonged periods of antiinflammatory co-treatments, is required.

Preclinical Research Mitochondria are cell organelles crucial to the production of cellular energy. Several lines of evidence have indicated that mitochondrial dysfunction could be related to the pathophysiology of CNS diseases including bipolar disorder, major depressive disorder, and schizophrenia. These changes include impaired energy metabolism in the brain, co-morbidity with mitochondrial diseases, the effects of psychotropics on mitochondrial function, increased mitochondrial DNA (mtDNA) deletion in the brain, and association with mtDNA polymorphisms. Additionally, psychotropic drug treatments can alter energy metabolism and may affect mitochondrial processes. This review focuses on recent findings regarding the effects of antidepressants on mitochondrial processes in psychiatric disorders. Drug Dev Res 77 : 400-406, 2016. © 2016 Wiley Periodicals, Inc.

30th Congress of the European-College-of-Neuropsychopharmacology (ECNP), Sep 02-05, 2017, Paris, France

Background Hypothalamic–pituitary–adrenal (HPA) axis dysregulation is a potential neurobiological mechanism proposed by vulnerability-stress model for schizophrenia. Recent studies highlighted the role of functional genetic variants of FKBP5 gene, which affect the activity of HPA axis following stress exposure, and supported the hypothesis of increased stress sensitivity in schizophrenia. Additionally, FKBP5 demethylation in Intron 7 was observed in stress-related conditions thus the purpose of this pilot study was to investigate FKBP5 methylation levels at Intron 7 in schizophrenia. Methods Ethnically homogeneous Serbian sample of 24 schizophrenia spectrum patients and 24 controls matched by age and gender with patients’ group, were analyzed regarding DNA methylation levels at three CpG sites and average methylation level in Intron 7. Accordingly, we covered the area of GRE that has been reported to be associated with altered stress responsiveness. Epigenetic changes in FKBP5 Intron 7 were measured by Sanger sequencing and compared between the groups using t test as appropriate. Results Analyses revealed decreased FKBP5 methylation at the three targeted CpG sites (CpG1, CpG2, and CpG3) in patients compared to controls (p=0.026, p=0.017, and p=0.027, respectively). Similarly, when we averaged methylation scores of the observed region in Intron 7, significant demethylation was detected in patients (p=0.003). Discussion To the best of our knowledge this is the first study which explored FKBP5 epigenetic changes in schizophrenia. Conclusively to previous stress-related conditions, our preliminary results revealed significant decrease of FKBP5 methylation levels in Intron 7 in patients with schizophrenia. FKBP5 demethylation presents further insight into the reported FKBP5 genetic influence in psychosis and could be promising terapeutic target for the prevention of the onset and the course of schizophrenia.

Peripheral inflammation induced by lipopolysaccharide (LPS) causes behavioural changes indicative for depression. The possible mechanisms involve the interference with neuroinflammatory, neuroendocrine, and neurotrophic processes. Apart from heterogeneity in the molecular background, sexual context may be another factor relevant to the manifestation of mood disturbances upon an immune challenge. We investigated sex-dependent effects of a 7-day LPS treatment of adult Wistar rats on depressive-like behaviour and their relation with hypothalamic neuroendocrine factor, corticotrophin-releasing hormone (CRH), proplastic brain-derived neurotropic factor (BDNF), pro-inflammatory cyclooxygenase-2 (COX-2) and nuclear factor kappa beta (NFkB). Also, their regulators, the glucocorticoid receptor (GR) and CCAAT enhancer-binding protein (C/EBP) beta were followed. LPS induced depressive-like behaviour in females was associated with the increased hypothalamic CRH and decreased BDNF, but not with COX-2. These changes were paralleled by an increase in nuclear GR, NFkB and 20 kDa C/EBP beta. LPS also altered behaviour in males and increased CRH expression, but in contrast to females, this was accompanied with the elevated COX-2, accumulation of cytosolic GR and elevated nuclear 38 kDa C/EBP beta and NFkB. In conclusion, depressive-like phenotype induced by LPS in both sexes emerges from similar HPA axis activation and sex-specific alterations of hypothalamic molecular signalling: in males it is related to compromised control of neuroinflamation connected with cytoplasmic GR retention, while in females it is related to diminished proplastic capacity of BDNF. Sex-dependent mechanisms by which inflammation alters hypothalamic processes and cause pathological behaviour in animals, could be operative in the treatment of depression-related brain inflammation. (C) 2015 Elsevier B.V. All rights reserved.

Glucocorticoid resistance is a common finding in major depressive disorder. Increased glucocorticoid receptor (GR) phosphorylation at serine 226 is associated with increased glucocorticoid resistance. Previously we have demonstrated that depressed patients exhibit higher levels of GR phosphorylated at serine 226 compared to healthy controls. The enzyme that is involved in this specific GR phosphorylation is c-Jun N-terminal kinase (JNK). We propose that modulation of glucocorticoid phosphorylation at serine 226, by targeting JNK signaling pathway, could be a potential strategy for antidepressant treatment. We base this assumption on the results of previous research that examined GR phosphorylation and JNK signaling in animal models and human studies. We also discuss the potential challenges in targeting JNK signaling pathway in depression. (C) 2015 Elsevier Ltd. All rights reserved.

Background: Hypothalamic-pituitary-adrenal (HPA) axis dysregulation is a proposed etiological mechanism of psychosis. Recent studies highlighted impact of the FKBP5 gene and its functional variant rs1360780, which risk (T) allele affects the activity of HPA axis following stress exposure, on psychotic patients exposed to early trauma (1). Additionally, risk allele and trauma dependent FKBP5 demethylation in intron 7 was observed in traumatized individuals (2). Thus, the purpose of this pilot study was to investigate influence of the risk allele and trauma on FKBP5 DNA methylation levels at intron 7 in psychotic patients and to compare it with healthy individuals. Methods: The sample consisted of 24 psychosis spectrum patients and 24 controls matched by age and gender. All participants were genotyped for rs1360780 and divided into 2 groups depending on the presence of the risk allele (risk and nonrisk group). DNA methylation levels at 3 CpG sites (CpG1, CpG2, and CpG3) in intron 7 were analyzed by Sanger sequencing. Early-life adversities were measured by Childhood Trauma Questionnaire. Pearson correlation and t test were performed as appropriate. Results: Analyses revealed decreased FKBP5 methylation at targeted CpG sites and averaged methylation level (AML) at intron 7 in patients compared to controls (P = .026, P = .017, P = .027, and P = .003, respectively). Decreased AML and methylation at CpG3 were observed comparing risk and nonrisk patients’ groups (P = .018 and P = .016, respectively). Additionally, decreased methylation was found in risk patients’ group compared to risk controls’ group. No differences were found comparing nonrisk groups. Furthermore, strong negative associations between trauma and methylation at CpG3 and AML were observed only in risk controls’ group (r = −0.707, P = .007; r = −0.741, P = .004, respectively). Conclusion: Our preliminary results revealed allele-specific epigenetic changes of the FKBP5 gene in psychotic patients, which is in line with previous reports in traumatized individuals. Trauma-related demethylation in risk controls’ group supports the hypothesis that psychotic and stress-related conditions could share common neurobiological underlying mechanism, such as HPA axis dysregulation, particularly in individuals with genetic predisposition for altered stress response.References1.Daskalakis NP, Binder EB. Schizophrenia in the spectrum of gene-stress interactions: the FKBP5 example. Schizophr Bull. 2015;41:323–329.2.Klengel T, Mehta D, Anacker C et al. Allele-specific FKBP5 DNA demethylation mediates gene-childhood trauma interactions. Nat Neurosci. 2013;16:33–41.