Potential causal association between gut microbiome and posttraumatic stress disorder.

BACKGROUND: The causal effects of gut microbiome and the development of posttraumatic stress disorder (PTSD) are still unknown. This study aimed to clarify their potential causal association using mendelian randomization (MR). METHODS: The summary-level statistics for gut microbiome were retrieved from a genome-wide association study (GWAS) of the MiBioGen consortium. As to PTSD, the Freeze 2 datasets were originated from the Psychiatric Genomics Consortium Posttraumatic Stress Disorder Working Group (PGC-PTSD), and the replicated datasets were obtained from FinnGen consortium. Single nucleotide polymorphisms meeting MR assumptions were selected as instrumental variables. The inverse variance weighting (IVW) method was employed as the main approach, supplemented by sensitivity analyses to evaluate potential pleiotropy and heterogeneity and ensure the robustness of the MR results. We also performed reverse MR analyses to explore PTSD's causal effects on the relative abundances of specific features of the gut microbiome. RESULTS: In Freeze 2 datasets from PGC-PTSD, eight bacterial traits revealed a potential causal association between gut microbiome and PTSD (IVW, all P < 0.05). In addition, Genus.Dorea and genus.Sellimonas were replicated in FinnGen datasets, in which eight bacterial traits revealed a potential causal association between gut microbiome and the occurrence of PTSD. The heterogeneity and pleiotropy analyses further supported the robustness of the IVW findings, providing additional evidence for their reliability. CONCLUSION: Our study provides the potential causal impact of gut microbiomes on the development of PTSD, shedding new light on the understanding of the dysfunctional gut-brain axis in this disorder. Our findings present novel evidence and call for investigations to confirm the association between their links, as well as to illuminate the underlying mechanisms.

Exploring the potential mechanism of Kaixinsan powder for the same pathogenesis of PTSD and anxiety based on network pharmacology and molecular docking: A review.

BACKGROUND: Post-traumatic stress disorder (PTSD) and anxiety are common mental illnesses and there are many similar pathogenesis and clinical manifestations between PTSD and anxiety. Kaixinsan powder (KXS), a commonly used prescription in traditional Chinese medicine, has been widely used to treat PTSD and anxiety. This study aims to explore the potential mechanisms of KXS for the same pathogenesis of PTSD and anxiety using a network pharmacology approach. METHODS: The bioactive components and relevant target genes of KXS were obtained from the database about Traditional Chinese Medicine. The key genes of PTSD and anxiety were derived from disease databases. Subsequently, the network of protein-protein interaction and a network of "drug-components-disease-targets" was constructed. In order to treat PTSD and anxiety, gene ontology enrichment and signaling pathway enrichment were analyzed by using R language and components-core targets associated were validated by molecular docking. RESULTS: One hundred three targets of KXS in treating PTSD and anxiety were identified. The results of protein-protein interaction analysis and molecular docking indicated that AKT1 and IL-6 were crucial targets. Moreover, KEGG analysis has shown that neuroactive ligand-receptor interaction, calcium signaling pathway, and cAMP signaling pathway may play crucial roles in treating PTSD and anxiety. Ten biological process, 10 molecular function, and 10 cellular component were revealed via gene ontology analysis. CONCLUSIONS: The network pharmacology study and molecular docking indicated that KXS treated anxiety and PTSD by multiple components, targets, and signaling pathways. These results provide an important reference for subsequent basic research on PTSD and anxiety.

[Effect of acupuncture on protein kinase R-like endoplasmic reticulum kinase/eukaryotic translation initiation factor 2α signaling pathway in hippocampus of rats with post-traumatic stress disorder].

OBJECTIVE: To observe the effect of acupuncture on the protein kinase R-like endoplasmic reticulum kinase (PERK)/eukaryotic translation initiation factor 2α (eIF2α) signaling pathway in the hippocampus of rats with post-traumatic stress disorder (PTSD), so as to explore the underlying mechanism of acupuncture in treating PTSD. METHODS: Twenty-eight SD rats were randomly divided into normal, model, acupuncture and sertraline groups, with 7 rats in each group. The PTSD model was established by single prolonged stress method. The next day after modeling, acupuncture was applied to "Baihui" (GV20) and "Dazhui" (GV14) of rats in the acupuncture group for 10 min, once a day for 7 days. Sertraline (10 mg/kg) was given by gavage to rats of the sertraline group daily for 7 days. The behavioral changes of rats were detected by elevated cross maze experiment and new object recognition experiment. The expression levels of PERK,phosphorylated(p)-PERK, eIF2α, p-eIF2α and activating transcription factor 4 (ATF4) proteins in hippocampus were detected by Western blot. The ultrastructure of hippocampal neurons was observed by transmission electron microscopy. RESULTS: Compared with the normal group, the percentage of times and retention time of entering the open arm of the elevated cross maze experiment, and new object recognition index were significantly decreased (P<0.01); the expression levels of p-PERK, p-eIF2α and ATF4 proteins in hippocampus were significantly increased (P<0.05) of rats in the model group. Compared with the model group, the percentage of times and retention time of entering the open arm, and new object recognition index were significantly increased (P<0.05，P<0.01), the expression levels of p-PERK, p-eIF2α and ATF4 proteins in hippocampus were significantly decreased (P<0.05, P<0.01) of rats in the acupuncture and sertraline groups; the expression level of eIF2α protein was significantly decreased (P<0.05) in the sertraline group. Hippocampal neurons in the model group were damaged, the rough endoplasmic reticulum showed severe dilation, the mitochondrial cristae showed reduction or mild cavitation; compared with the model group, hippocampal neurons structural damage and the rough endoplasmic reticulum dilation were alleviated， and only some of the mitochondrial cristae decreased in the acupuncture and sertraline groups. CONCLUSION: Acupuncture can alleviate the anxiety behavior as well as the recognition and memory ability of PTSD rats, and its mechanism may be related to the inhibition of hippocampus PERK/eIF2α signaling pathway and the reduction of hippocampal neuron damage caused by endoplasmic reticulum stress.

The Anxiolytic-Like Effects of Protocatechuic Acid in an Animal Model of Post-Traumatic Stress Disorder.

Post-traumatic stress disorder (PTSD) is a serious psychiatric disorder characterized by impaired fear extinction, depression, and anxiety caused by dysregulation of the hypothalamic-pituitary-adrenal axis and an imbalance of monoamines. Protocatechuic acid (PCA; 3,4-dihydroxybenzoic acid), a major polyphenol metabolite, has various pharmacological effects, such as anti-inflammatory, antioxidant, anti-apoptotic, and neuroprotective activities. In this study, the efficacy of PCA for fear extinction, antidepressant, and anxiolytic effects in PTSD-mediated psychiatric disorders, were evaluated by exposing rats to single prolonged stress (SPS). Male rats were administered PCA (100 or 200 mg/kg) once daily for 14 days after exposure to SPS. PCA significantly decreased situational fear, depressive and anxiety-like behaviors, and corticosterone levels. In addition, PCA regulated the imbalance of serotonin and norepinephrine in the fear circuit region (i.e., the medial prefrontal cortex and hippocampus [Hipp]), and suppressed the decrease in brain-derived neurotrophic factor mRNA expression in the Hipp. The results showed that PCA administration improves freezing behavior and has antidepressant and anti-anxiety effects through modulation of the serotonergic nervous system and monoamines in rats. These results indicated that PCA may be useful as a food ingredient to prevent PTSD.

[Effect of acupuncture on endoplasmic reticulum stress-related factors in hippocampus of post-traumatic stress disorder rats].

OBJECTIVE: To observe the effect of acupuncture on endoplasmic reticulum stress-related molecules glucose regulated protein 78 kD (GRP78), C/EBP homologous protein (CHOP), cysteinyl aspartate specific proteinase-12 (Caspase-12) and cysteinyl aspartate specific proteinase-3 (Caspase-3)in the hippocampus of rats with post-traumatic stress disorder, so as to explore the possible mechanism of acupuncture in treating post-traumatic stress disorder (PTSD). METHODS: Twenty-eight SD rats were randomly divided into normal control, model, acupuncture and sertraline groups, with 7 rats in each group. The PTSD rat model was established by single prolonged stress. After modeling, acupuncture was applied to "Baihui" (GV20) and "Dazhui" (GV14) for rats of the acupuncture group for 10 min, once a day for 7 days. Sertraline (10 mg/kg) was given by gavage to rats of the sertraline group daily for 7 days. Rats' behavior was assessed by open field test and novelty-suppressed test. The mRNA expression levels of GRP78 and CHOP in the hippocampus were detected by real-time PCR. The expression le-vels of Caspase-12 and Caspase-3 in the hippocampus were detected by Western blot. RESULTS: Compared with the normal control group, the rearing and crossing times were decreased (P<0.05), the time remaining in the central zone and the total distance of movement were significantly reduced (P<0.01, P<0.05), the time of entering the central area for the first time was significantly increased (P<0.01), the latency of the novelty-suppressed feeding was significantly increased (P<0.05) in the model group, meanwhile the expression level of GRP78 and CHOP mRNAs, Caspase-12 and Caspase-3 proteins in the hippocampus were increased (P<0.05, P<0.01). In comparison with the model group, the crossing times, the time remaining in the central zone and total distance of movement were increased significantly (P<0.05, P<0.01), while the time of entering the central area for the first time, the expression levels of GRP78 and CHOP mRNAs, and Caspase-12 protein in the hippocampus were obviously decreased (P<0.05, P<0.01) in the acupuncture and sertraline groups. In addition, the rearing times were increased significantly (P<0.05), the latency of the novelty-suppressed feeding and the expression of Caspase-3 were decreased significantly (P<0.05) in the sertraline group than in the model group. CONCLUSION: Acupuncture can significantly down-regulate the expression of endoplasmic reticulum stress-related molecules GRP78, CHOP and Caspase-12 in PTSD rats, which may be one of the mechanisms of acupuncture in treating PTSD.

Reduction of DNMT3a and RORA in the nucleus accumbens plays a causal role in post-traumatic stress disorder-like behavior: reversal by combinatorial epigenetic therapy.

Post-traumatic stress disorder (PTSD) is an incapacitating trauma-related disorder, with no reliable therapy. Although PTSD has been associated with epigenetic alterations in peripheral white blood cells, it is unknown where such changes occur in the brain, and whether they play a causal role in PTSD. Using an animal PTSD model, we show distinct DNA methylation profiles of PTSD susceptibility in the nucleus accumbens (NAc). Data analysis revealed overall hypomethylation of different genomic CG sites in susceptible animals. This was correlated with the reduction in expression levels of the DNA methyltransferase, DNMT3a. Since epigenetic changes in diseases involve different gene pathways, rather than single candidate genes, we next searched for pathways that may be involved in PTSD. Analysis of differentially methylated sites identified enrichment in the RAR activation and LXR/RXR activation pathways that regulate Retinoic Acid Receptor (RAR) Related Orphan Receptor A (RORA) activation. Intra-NAc injection of a lentiviral vector expressing either RORA or DNMT3a reversed PTSD-like behaviors while knockdown of RORA and DNMT3a increased PTSD-like behaviors. To translate our results into a potential pharmacological therapeutic strategy, we tested the effect of systemic treatment with the global methyl donor S-adenosyl methionine (SAM), for supplementing DNA methylation, or retinoic acid, for activating RORA downstream pathways. We found that combined treatment with the methyl donor SAM and retinoic acid reversed PTSD-like behaviors. Thus, our data point to a novel approach to the treatment of PTSD, which is potentially translatable to humans.

Electroacupuncture ameliorates post-traumatic stress disorder in rats via a mechanism involving the BDNF-TrkB signaling pathway.

Post-traumatic stress disorder (PTSD) is a mental health condition triggered by a terrifying event, causing flashbacks, nightmares and severe anxiety. It develops in individuals who have experienced a shocking, scary, or dangerous event. Electroacupuncture is reported to be effective for the treatment of PTSD. The present study was carried out to investigate the protective effect of electroacupuncture in a rat model of PTSD, and the mechanism involved. Specific-pathogen-free male Sprague Dawley rats (n = 30) weighing 180 - 220 g (mean weight = 200 ± 20 g) were randomly assigned to three groups of ten rats each: control group, single-prolonged stress (SPS) group, and treatment group. The treatment group rats received electroacupuncture. Changes in PTSD-like behavior were assessed using locomotor activity, elevated plus-maze (EPM) and fear conditioning tests. The mRNA and protein expressions of brain-derived neurotrophic factor (BDNF) and tropomyosin receptor kinase B (TrkB) were determined using real-time quantitative polymerase chain reaction (qRT-PCR) and Western blotting, respectively. Co-immunoprecipitation (Co-IP) was used to measure BDNF and TrkB binding interaction, while chromatin immunoprecipitation (ChIP) was used to evaluate the binding between cyclic adenosine monophosphate (cAMP) response element-binding protein (CREB) and its target genes. Electroacupuncture significantly increased locomotor activity and exploratory behavior, but significantly reduced general fear and anxiety in SPS rats (p < 0.05). It also significantly upregulated the mRNA and protein expressions of BDNF and TrkB, and increased the binding of BDNF to its receptor TrkB (p < 0.05). Electroacupuncture significantly increased the binding of CREB to BDNF promoter region (p < 0.05). Electroacupuncture ameliorates PTSD in rats via a mechanism involving the BDNF-TrkB signaling pathway.

FKBP5 haplotypes and PTSD modulate the resting-state brain activity in Han Chinese adults who lost their only child.

The stress-related gene FKBP5 has been related to dysregulated glucocorticoid receptor (GR) signaling, showing increased GR sensitivity in trauma-exposed subjects with post-traumatic stress disorder (PTSD) but not in those without PTSD. However, the neural mechanism underlying the effects of FKBP5 remains poorly understood. Two hundred and thirty-seven Han Chinese adults who had lost their only child were included. Four FKBP5 single nucleotide polymorphisms (rs3800373, rs9296158, rs1360780, and rs9470080) were genotyped. All 179 participants were successfully divided into three FKBP5 diplotype subgroups according to two major FKBP5 H1 and H2 yin yang haplotypes. Brain average spectral power was compared using a two-way (PTSD diagnosis and FKBP5 diplotypes) analysis of covariance within four separate frequency bands (slow-5, slow-4, slow-3, and slow-2). Adults with PTSD showed lower spectral power in bilateral parietal lobules in slow-4 and in left inferior frontal gyrus (IFG) in slow-5. There was significant FKBP5 diplotype main effect in anterior cingulate cortex (ACC) in slow-4 (H1/H1 higher than other two subgroups), and in precentral/postcentral gyri and middle cingulate cortex (MCC) in slow-3 (H2/H2 higher than other two subgroups). Also, there was a significant diagnosis × FKBP5 diplotype interaction effect in right parietal lobule in slow-3. These findings suggest that adults with PTSD have lower low-frequency power in executive control network regions. Lower power in ACC and greater power in the motor/sensory areas in FKBP5 high-risk diplotype group suggest a disturbance of emotional processing and hypervigilance/sensitization to threatening stimuli. The interaction effect of diagnosis × FKBP5 in parietal lobule may contribute to PTSD development.

Investigating the role of the amygdala orexin receptor 1 in memory acquisition and extinction in a rat model of PTSD.

Understanding the mechanisms underlying memory is essential for the treatment of post-traumatic stress disorder (PTSD). Orexin, as a lateral hypothalamic (LH) neuropeptide, interferes with the stages of memory, primarily through the orexin receptor1 (Orx1R). The aim of this study was to evaluate the effects of amygdala Orx1R in the acquisition and extinction processes of PTSD modeled in animals. In three experiments, rats were divided into three groups: control (Naïve), shock (receiving a foot shock), and PTSD (experiencing Single prolonged stress (SPS) method). The first experiment aimed to evaluate LH activity in PTSD modeled rats. The second and third experiments aimed to evaluate the effects of Orx1R in the acquisition and extinction of fear memory in PTSD modeled animals. SB334867 (SB) or its solvent was microinjected into the amygdala and the rats were subjected to conditioning thereafter. In the second group, we used a single injection after conditioning. In the third group, we used three consecutive injections (one after each memory test). Some behaviors and Orx1R expression were evaluated. The freezing response was significantly longer in the PTSD group than on the control. Similarly, anxiety and sensitized fear were also intensified. CFos expression levels in LH was higher in the PTSD group. Inhibition of Orx1R in the amygdala significantly decreased memory acquisition, diminished anxiety, and decreased the sensitized fear in the SB group. Applying SB to the amygdala after each fear memory test significantly decreased freezing. Expression of Orx1R was significantly higher following fear conditioning. These results indicate a likely involvement of the orexin and amygdalar Orx1R in memory acquisition and in extinction of PTSD.

Clinical Therapeutic Strategy and Neuronal Mechanism Underlying Post-Traumatic Stress Disorder (PTSD).

Post-traumatic stress disorder (PTSD) is characterized by an exaggerated response to contextual memory and impaired fear extinction, with or without mild cognitive impairment, learning deficits, and nightmares. PTSD is often developed by traumatic events, such as war, terrorist attack, natural calamities, etc. Clinical and animal studies suggest that aberrant susceptibility of emotion- and fear-related neurocircuits, including the amygdala, prefrontal cortex (PFC), and hippocampus may contribute to the development and retention of PTSD symptoms. Psychological and pharmacological therapy, such as cognitive behavioral therapy (CBT), and treatment with anti-depressive agents and/or antipsychotics significantly attenuate PTSD symptoms. However, more effective therapeutics are required for improvement of quality of life in PTSD patients. Previous studies have reported that ω3 long-chain polyunsaturated fatty acid (LCPUFA) supplements can suppress the development of PTSD symptoms. Fatty acid binding proteins (FABPs) are essential for LCPUFA intracellular trafficking. In this review, we have introduced Fabp3 null mice as an animal model of PTSD with impaired fear extinction. Moreover, we have addressed the neuronal circuits and novel therapeutic strategies for PTSD symptoms.

The ethanolic extract of Aralia continentalis ameliorates cognitive deficits via modifications of BDNF expression and anti-inflammatory effects in a rat model of post-traumatic stress disorder.

BACKGROUND: Post-traumatic stress disorder (PTSD) is a disease associated with that the experience of traumatic stress. The traumatic experience results in the development of a prolonged stress response that causes impaired memory function and increased inflammation in the hippocampus. Currently, antidepressants are the only approved therapy for PTSD. However, the efficacy of antidepressants in the treatment of PTSD is marginal. The ethanol extract of Aralia continentalis (AC) is traditionally used in oriental medicine, and has been showed to possess pharmacological properties, including anti-inflammatory, anti-cancer, anti-atherosclerotic, and anti-diabetic effects. Nevertheless, the effects of AC on cognitive memory and its mechanism of action in PTSD remain unclear. Given the necessity of further treatment options for PTSD, we investigated the effect of AC on the spatial cognitive impairment caused by single prolonged stress (SPS) in a rat model of PTSD. METHODS: Male rats were treated with various intraperitoneal (i.p.) doses of AC for 21 consecutive days after inducing chronic stress with the SPS procedure. RESULTS: Cognitive impairment caused by SPS were inhibited after treatment with 100 mg/kg AC, as measured by the Morris water maze test and an object recognition test. Additionally, AC treatment significantly alleviated memory-related decreases in brain-derived neurotrophic factor (BDNF) mRNA and protein levels in the hippocampus. Our results suggest that AC significantly inhibited the cognitive deficits caused by SPS via increased expression of pro-inflammatory cytokines, including tumor necrosis factor-α and interleukin-6, in the rat brain. CONCLUSIONS: AC reversed the behavioral impairments and inflammation triggered by SPS-derived traumatic stress and should be further evaluated as a potential therapeutic drug for PTSD.

Genes known to escape X chromosome inactivation predict co-morbid chronic musculoskeletal pain and posttraumatic stress symptom development in women following trauma exposure.

Co-morbid chronic musculoskeletal pain (CMSP) and posttraumatic stress symptoms (PTSS) are frequent sequelae of motor vehicle collision, are associated with greater disability than either outcome alone, and are more prevalent in women than men. In the current study we assessed for evidence that gene transcripts originating from the X chromosome contribute to sex differences in vulnerability to CMSP and PTSS after motor vehicle collision. Nested samples were drawn from a longitudinal study of African American individuals, and CMSP (0-10 numeric rating scale) and PTSS (impact of events scale, revised) outcomes were assessed 6 months following motor vehicle collision. Blood RNA were sequenced (n = 101) and the relationship between X chromosome mRNA expression levels and co-morbid CMSP and PTSS outcomes was evaluated using logistic regression analyses. A disproportionate number of peritraumatic X chromosome mRNA predicting CMSP and PTSS in women were genes previously found to escape X chromosome inactivation (11/40, z = -2.9, p = .004). Secondary analyses assessing gene ontology relationships between these genes identified an enrichment in genes known to influence neuronal plasticity. Further, the relationship of expression of two critical regulators of X chromosome inactivation, X-inactive specific transcript (XIST) and Yin Yang 1 (YY1), was different in women developing CMSP and PTSS. Together, these data suggest that X chromosome genes that escape inactivation may contribute to sex differences in vulnerability to CMSP and PTSS after motor vehicle collision.

Effects of Epigallocatechin Gallate on Behavioral and Cognitive Impairments, Hypothalamic-Pituitary-Adrenal Axis Dysfunction, and Alternations in Hippocampal BDNF Expression Under Single Prolonged Stress.

Post-traumatic stress disorder (PTSD) is a traumatic stress-related psychiatric disorder stimulated by experience. Green tea has potent antioxidative properties, due, in part, to the catechin (-) epigallocatechin-3-gallate (EGCG). EGCG is an important polyphenol with advantageous effects on anxiety and depression. Nevertheless, the mechanism about the inhibition of PTSD-like symptoms of EGCG is still unidentified. We examined whether EGCG improved learning and memory deficit stimulated in rats after single prolonged stress (SPS). Rats were administrated intraperitoneally (i.p.) with EGCG for 14 successive days after the SPS process. The SPS procedure stimulated cognitive deficit in the Morris water maze test and the object recognition task, and this impairment was improved by EGCG (25 mg/kg, i.p.). Daily EGCG administration significantly decreased the freezing response to contextual fear conditioning. The administration of EGCG also significantly moderated memory-related decreases in the alternation of cAMP-response element-binding protein and brain-derived neurotrophic factor in the hippocampus. Our results suggest that EGCG alleviated SPS-stimulated learning and memory deficit by inhibiting the increase of neuroinflammation in the rat brain. In addition, EGCG reversed the alternation of allopregnanolone and progesterone in the brain, and diminished simultaneously the hypothalamic-pituitary-adrenal axis dysfunction. Thus, EGCG reversed learning and memory-related behavioral dysfunction and molecular alternation accelerated by traumatic stress and may be a useful therapeutic material for PTSD.

The role of suboptimal mitochondrial function in vulnerability to post-traumatic stress disorder.

Post-traumatic stress disorder remains the most significant psychiatric condition associated with exposure to a traumatic event, though rates of traumatic event exposure far outstrip incidence of PTSD. Mitochondrial dysfunction and suboptimal mitochondrial function have been increasingly implicated in several psychopathologies, and recent genetic studies have similarly suggested a pathogenic role of mitochondria in PTSD. Mitochondria play a central role in several physiologic processes underlying PTSD symptomatology, including abnormal fear learning, brain network activation, synaptic plasticity, steroidogenesis, and inflammation. Here we outline several potential mechanisms by which inherited (genetic) or acquired (environmental) mitochondrial dysfunction or suboptimal mitochondrial function, may contribute to PTSD symptomatology and increase susceptibility to PTSD. The proposed pathogenic role of mitochondria in the pathophysiology of PTSD has important implications for prevention and therapy, as antidepressants commonly prescribed for patients with PTSD have been shown to inhibit mitochondrial function, while alternative therapies shown to improve mitochondrial function may prove more efficacious.

Integrating Endocannabinoid Signaling and Cannabinoids into the Biology and Treatment of Posttraumatic Stress Disorder.

Exposure to stress is an undeniable, but in most cases surmountable, part of life. However, in certain individuals, exposure to severe or cumulative stressors can lead to an array of pathological conditions including posttraumatic stress disorder (PTSD), characterized by debilitating trauma-related intrusive thoughts, avoidance behaviors, hyperarousal, as well as depressed mood and anxiety. In the context of the rapidly changing political and legal landscape surrounding use of cannabis products in the USA, there has been a surge of public and research interest in the role of cannabinoids in the regulation of stress-related biological processes and in their potential therapeutic application for stress-related psychopathology. Here we review the current state of knowledge regarding the effects of cannabis and cannabinoids in PTSD and the preclinical and clinical literature on the effects of cannabinoids and endogenous cannabinoid signaling systems in the regulation of biological processes related to the pathogenesis of PTSD. Potential therapeutic implications of the reviewed literature are also discussed. Finally, we propose that a state of endocannabinoid deficiency could represent a stress susceptibility endophenotype predisposing to the development of trauma-related psychopathology and provide biologically plausible support for the self-medication hypotheses used to explain high rates of cannabis use in patients with trauma-related disorders.

Behavioral and inflammatory response in animals exposed to a low-pressure blast wave and supplemented with ß-alanine.

This study investigated the benefit of ß-alanine (BA) supplementation on behavioral and cognitive responses relating to mild traumatic brain injury (mTBI) and post-traumatic stress disorder (PTSD) in rats exposed to a low-pressure blast wave. Animals were fed a normal diet with or without (PL) BA supplementation (100 mg kg-1) for 30-day, prior to being exposed to a low-pressure blast wave. A third group of animals served as a control (CTL). These animals were fed a normal diet, but were not exposed to the blast. Validated cognitive-behavioral paradigms were used to assess both mTBI and PTSD-like behavior on days 7-14 following the blast. Brain-derived neurotrophic factor (BDNF), neuropeptide Y, glial fibrillary acidic protein (GFAP) and tau protein expressions were analyzed a day later. In addition, brain carnosine and histidine content was assessed as well. The prevalence of animals exhibiting mTBI-like behavior was significantly lower (p = 0.044) in BA than PL (26.5 and 46%, respectively), but no difference (p = 0.930) was noted in PTSD-like behavior between the groups (10.2 and 12.0%, respectively). Carnosine content in the cerebral cortex was higher (p = 0.048) for BA compared to PL, while a trend towards a difference was seen in the hippocampus (p = 0.058) and amygdala (p = 0.061). BDNF expression in the CA1 subregion of PL was lower than BA (p = 0.009) and CTL (p < 0.001), while GFAP expression in CA1 (p = 0.003) and CA3 (p = 0.040) subregions were higher in PL than other groups. Results indicated that BA supplementation for 30-day increased resiliency to mTBI in animals exposed to a low-pressure blast wave.

Changes in Galanin Systems in a Rat Model of Post-Traumatic Stress Disorder (PTSD).

Post-traumatic stress disorder (PTSD) is a chronic syndrome triggered by exposure to trauma and a failure to recover from a normal negative emotional reaction to traumatic stress. The neurobiology of PTSD and the participation of neuropeptides in the neural systems and circuits that control fear and anxiety are not fully understood. The long-term dysregulation of neuropeptide systems contributes to the development of anxiety disorders, including PTSD. The neuropeptide galanin (Gal) and its receptors participate in anxiety-like and depression-related behaviors via the modulation of neuroendocrine and monoaminergic systems. The objective of this research was to investigate how Gal expression changes in the brain of rats 2 weeks after exposure to footshock. Rats exposed to footshocks were subdivided into high responders (HR; immobility>60%) and low responders (LR; immobility<40%) based on immobility elicited by a novel tone one day after exposure. On day 14, rats were anesthetized, and the amygdala, hypothalamus, pituitary and adrenal glands were removed for analysis using real-time polymerase chain reaction (RT-PCR). Gal mRNA levels were increased in the amygdala and hypothalamus of HR compared with the control and LR. In contrast, Gal mRNA levels were decreased in the adrenal and pituitary glands of HR compared with the control and LR. Thus, the differential regulation (dysregulation) of the neuropeptide Gal in these tissues may contribute to anxiety and PTSD development.

FAAH Gene Variation Moderates Stress Response and Symptom Severity in Patients with Posttraumatic Stress Disorder and Comorbid Alcohol Dependence.

BACKGROUND: A common single nucleotide polymorphism (C385A) in the human fatty acid amide hydrolase (FAAH) gene has been associated with decreased distress responses in healthy volunteers, but its role in psychiatric disorders remains unknown. Here, we obtained genotypes and carried out a secondary analysis of subjects from a trial of comorbid posttraumatic stress disorder (PTSD) and alcohol dependence (AD). We evaluated the effects of C385A variation on behavioral and biochemical biomarkers of distress responses. METHODS: Forty-nine patients with PTSD and AD were admitted for 4 weeks to an experimental medicine unit at the National Institutes of Health Clinical Center. Following detoxification, stress reactivity and peripheral endocannabinoid (eCB) levels were assessed in response to a challenge session using personalized auditory guided imagery. Over the course of the study, subjects were also evaluated for changes in PTSD symptom severity. RESULTS: FAAH C385A allele carriers showed a marked increase in serum anandamide levels at baseline and throughout the stress challenge procedure compared with C allele homozygotes, while levels of eCBs primarily metabolized through other enzymatic activity, such as 2-arachidonoylglycerol, did not differ between genotype groups. FAAH C385A carriers also had decreased subjective anxiety responses to the stress challenge. Similar effects of FAAH C385A genotype were found at the level of clinical PTSD symptom severity, in particular in the arousal domain. CONCLUSIONS: This is to our knowledge the first study showing that FAAH C385A variation modulates stress responses in subjects with disorders characterized by increased stress reactivity. These findings point to the eCB pathway as a promising target for future antistress therapeutics.

Dysregulated immune system networks in war veterans with PTSD is an outcome of altered miRNA expression and DNA methylation.

Post-traumatic stress disorder patients experience chronic systemic inflammation. However, the molecular pathways involved and mechanisms regulating the expression of genes involved in inflammatory pathways in PTSD are reported inadequately. Through RNA sequencing and miRNA microarray, we identified 326 genes and 190 miRNAs that were significantly different in their expression levels in the PBMCs of PTSD patients. Expression pairing of the differentially expressed genes and miRNAs indicated an inverse relationship in their expression. Functional analysis of the differentially expressed genes indicated their involvement in the canonical pathways specific to immune system biology. DNA methylation analysis of differentially expressed genes also showed a gradual trend towards differences between control and PTSD patients, again indicating a possible role of this epigenetic mechanism in PTSD inflammation. Overall, combining data from the three techniques provided a holistic view of several pathways in which the differentially expressed genes were impacted through epigenetic mechanisms, in PTSD. Thus, analysis combining data from RNA-Seq, miRNA array and DNA methylation, can provide key evidence about dysregulated pathways and the controlling mechanism in PTSD. Most importantly, the present study provides further evidence that inflammation in PTSD could be epigenetically regulated.

Molecular Mechanisms of Posttraumatic Stress Disorder (PTSD) as a Basis for Individualized and Personalized Therapy: Rationale, Design and Methods of the South Eastern Europe (SEE)-PTSD study.

Posttraumatic Stress Disorder (PTSD) is a major health problem in South Eastern Europe (SEE). Available treatment options are not efficient enough and the course is often chronic. Little is known about molecular mediators and moderators of pathogenesis and therapy. Genetic and epigenetic variation may be one central molecular mechanism. We therefore established a consortium combining clinical expertise on PTSD from SEE countries Bosnia-Herzegovina (Sarajevo, Tuzla and Mostar), Kosovo (Prishtina) and Croatia (Zagreb) with genetic and epigenetic competence from Germany (Würzburg) in 2011 within the framework of the DAAD (Deutscher Akademischer Austauschdienst)-funded Stability Pact for South Eastern Europe. After obtaining ethical votes and performing rater trainings as well as training in DNA extraction from EDTA blood between 2011 and 2013, we recruited 747 individuals who had experienced war-related trauma in the SEE conflicts between 1991 and 1999. 236 participants had current PTSD, 161 lifetime PTSD and 350 did not have and never had PTSD. Demographic and clinical data are currently merged together with genetic and epigenetic data in a single database to allow for a comprehensive analysis of the role of genetic and epigenetic variation in the pathogenesis and therapy of PTSD. Analyses will be done to a great degree by PhD students from participating SEE centers who in addition to participation in the project had an opportunity to take part in spring and summer schools of the DFG (Deutsche Forschungsgemeinschaft) funded Research Training Group (RTG) 1253 and thus meet PhD students from Germany and other countries We are confident that our project will not only contribute to a better understanding of genetic and epigenetic mechanisms of PTSD as a basis for future individualized and personalized therapies, but also to the academic development of South Eastern Europe.