The stressed CNS: when glucocorticoids aggravate inflammation

Brain Trauma, Glucocorticoids and Neuroinflammation: Dangerous Liaisons for the Hippocampus

Glucocorticoid-dependent mechanisms of inflammation-mediated distant hippocampal damage are discussed with a focus on the consequences of traumatic brain injury. The effects of glucocorticoids on specific neuronal populations in the hippocampus depend on their concentration, duration of exposure and cell type. Previous stress and elevated level of glucocorticoids prior to pro-inflammatory impact, as well as long-term though moderate elevation of glucocorticoids, may inflate pro-inflammatory effects. Glucocorticoid-mediated long-lasting neuronal circuit changes in the hippocampus after brain trauma are involved in late post-traumatic pathology development, such as epilepsy, depression and cognitive impairment. Complex and diverse actions of the hypothalamic–pituitary–adrenal axis on neuroinflammation may be essential for late post-traumatic pathology. These mechanisms are applicable to remote hippocampal damage occurring after other types of focal brain damage (stroke, epilepsy) or central nervous system diseases without obvious focal injury. Thus, the liaisons of excessive glucocorticoids/dysfunctional hypothalamic–pituitary–adrenal axis with neuroinflammation, dangerous to the hippocampus, may be crucial to distant hippocampal damage in many brain diseases. Taking into account that the hippocampus controls both the cognitive functions and the emotional state, further research on potential links between glucocorticoid signaling and inflammatory processes in the brain and respective mechanisms is vital.

Dysfunction of Inflammatory Pathways and Their Relationship With Psychological Factors in Adult Female Patients With Eating Disorders

The attempts to clarify the origin of eating disorders (ED) have not been completely successful and their etiopathogenesis remains unknown. Current research shows an activation of the immune response in neuropsychiatric diseases, including ED. We aimed to investigate immune response parameters in patients with ED and to identify psychological factors influencing the inflammatory response. The relationship between inflammation markers and impulsivity and affective symptomatology was explored as well. Thirty-four adult female patients with current diagnosis of ED, none of them under psychopharmacological treatment (excluding benzodiazepines), were included in this study. Patients were compared with a healthy control group of fifteen adult females. The levels of inflammatory markers and indicators of oxidative/nitrosative stress were evaluated in plasma and/or in peripheral blood mononuclear cells (PBMCs). Subjects were assessed by means of different ED evaluation tools. Additionally, the Barratt Impulsiveness Scale, the Montgomery-Asberg Depression Rating Scale and the Hamilton Anxiety Rating Scale were also employed. Patients with ED shown increased plasma levels of the pro-inflammatory nuclear factor kappa B (NFκB) and the cytokine tumor necrosis factor-alpha (TNF-α), among other factors and an increment in the oxidative/nitrosative stress as well as increased glucocorticoid receptor (GR) expression levels in their PBMCs. Moreover, the inflammatory prostaglandin E₂ (PGE₂) correlated with impulsiveness and the anti-inflammatory prostaglandin J₂ (15d-PGJ₂) correlated with depressive symptomatology. Our results point towards a relationship between the immune response and impulsiveness and between the immune response and depressive symptomatology in female adult patients with ED.

"I Don't Know Why I've Got this Pain!" Allostasis as a Possible Explanatory Model

Explaining the onset and maintenance of pain can be challenging in many clinical presentations. Allostasis encompasses the mechanisms through which humans adapt to stressors to maintain physiological stability. Due to related neuro-endocrine-immune system effects, allostasis and allostatic load (the cumulative effects on the brain and body that develop through the maintenance of physiological stability) offer the potential to explain the development and maintenance of musculoskeletal pain in certain cases. This paper outlines the concept of allostatic load, highlights the evidence for allostatic load in musculoskeletal pain conditions to date, and discusses mechanisms through which allostatic load influences pain, with particular focus on hypothalamic-pituitary-adrenal axis and sympathetic nervous system function and central, brain-driven governance of these systems. Finally, through case examples, consideration is given as to how allostatic load can be integrated into clinical reasoning and how it can be used to help explain pain to individuals and guide clinical decision-making.

IMPACT

Awareness of the concept of allostatic load, and subsequent assessment of physical and psychological stressors potentially contributing to allostatic load, may facilitate a broader understanding of the multidimensional presentations of many people with pain, both acute and persistent. This may facilitate discussion between clinicians and their patients regarding broader influences on their presentations and drive more targeted and inclusive pain management strategies.

Microglia and HPA axis in depression: An overview of participation and relationship

Objectives: This narrative review article provides an overview on the involvement of microglia and the hypothalamic-pituitary-adrenal (HPA) axis in the pathophysiology of depression, as well investigates the mutual relationship between these two entities: how microglial activation can contribute to the dysregulation of the HPA axis, and vice versa.Methods: Relevant studies and reviews already published in the Pubmed electronic database involving the themes microglia, HPA axis and depression were used to meet the objectives.Results: Exposition to stressful events is considered a common factor in the mechanisms proposed to explain the depressive disorder. Stress can activate microglial cells, important immune components of the central nervous system (CNS). Moreover, another system involved in the physiological response to stressors is the hypothalamic-pituitary-adrenal (HPA) axis, the main stress response system responsible for the production of the glucocorticoid hormone (GC). Also, mediators released after microglial activation can stimulate the HPA axis, inducing production of GC. Likewise, high levels of GCs are also capable of activating microglia, generating a vicious cycle.Conclusion: Immune and neuroendocrine systems seems to work in a coordinated manner and that their dysregulation may be involved in the pathophysiology of depression since neuroinflammation and hypercortisolism are often observed in this disorder.

Hydrocortisone Long-term Treatment Effect on Immunomodulatory Properties of Human Adipose-Derived Mesenchymal Stromal/Stem Cells

Cortisol is secreted in prolonged stress and has therapeutic effects in inflammatory diseases. Considering the immunomodulatory effects of mesenchymal stem cells, here we investigated the effect of hydrocortisone (HC) long-term treatment on immunomodulatory properties of human adipose-derived mesenchymal stromal/stem cells (ASCs). Isolated ASCs from healthy subjects were treated with different HC concentrations for 14 days. The effect of HC-treated ASCs on the proliferative response of peripheral blood mononuclear cells (PBMCs) was evaluated in ASCs/2-way mixed leukocyte reaction coculture using 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT)-assay. HC-treated ASCs were further divided into interferon gamma (IFN-γ) stimulated and unstimulated groups. Transforming growth factor beta 1 (TGF-β1) and interleukin (IL)-6 levels were measured in culture supernatants by enzyme-linked immunosorbent assay. Relative expression of cyclooxygenase-2 (COX-2), hepatocyte growth factor, indoleamine dioxygenase, and programmed death-ligand 1 genes was assessed by real-time PCR. Levels of TGF-β1 and COX-2 expression were elevated in unstimulated ASCs, while exposure to high concentration of HC significantly increased TGF-β1 levels and reduced COX-2 expression. Unstimulated HC-5-μM-treated ASCs increased PBMC proliferation ratio on day 2 of coculture compared to the control group (P = 0.05). In IFN-γ stimulated condition, pretreatment with HC-5 μM resulted in a significantly increased IL-6 and significantly decreased COX-2 expression compared to the HC untreated control group. In conclusion, our results showed various alterations of ASC immunomodulatory related features as a result of long-term exposure of different concentrations of HC. It seems that HC at low concentration pushed the balance toward extended immune response in ASCs, while this observation wasn't persistent in ASCs treated with higher concentrations of HC.

The Importance of Biobehavioral Research to Examine the Physiological Effects of Racial and Ethnic Discrimination in the Latinx Population

A growing body of research is documenting how racial and ethnic populations embody social inequalities throughout the life course. Some scholars recommend the integration of biospecimens representing the hypothalamic-pituitary-adrenal axis, neurological and endocrinological processes, and inflammation to capture the embodiment of inequality. However, in comparison to other racial and ethnic groups, there has been little research examining how Hispanic/Latinx persons embody racial and ethnic discrimination, much less resulting from institutional and structural racism. We provide a rationale for expanding biobehavioral research examining the physiological consequences of racism among Latinx persons. We identify gaps and make recommendations for a future research agenda in which biobehavioral research can expand knowledge about chronic disease inequities among Latinx populations and inform behavioral and institutional interventions. We end by cautioning readers to approach the recommendations in this article as a call to expand the embodiment of racism research to include the diverse Latinx population as the United States addresses racial inequity.

Neuroinflammation, Early-Life Adversity, and Brain Development

The overarching objective is to review how early exposure to adversity interacts with inflammation to alter brain maturation. Both adversity and inflammation are significant risk factors for psychopathology. Literature relevant to the effects of adversity in children and adolescents on brain development is reviewed. These studies are supported by research in animals exposed to species-relevant stressors during development. While it is known that exposure to adversity at any age increases inflammation, the effects of inflammation are exacerbated at developmental stages when the immature brain is uniquely sensitive to experiences. Microglia play a vital role in this process, as they scavenge cellular debris and prune synapses to optimize performance. In essence, microglia modify the synapse to match environmental demands, which is necessary for someone with a history of adversity. Overall, by piecing together clinical and preclinical research areas, what emerges is a picture of how adversity uniquely sculpts the brain. Microglia interactions with the inhibitory neurotransmitter GABA (specifically, the subtype expressing parvalbumin) are discussed within contexts of development and adversity. A review of inflammation markers in individuals with a history of abuse is combined with preclinical studies to describe their effects on maturation. Inconsistencies within the literature are discussed, with a call for standardizing methodologies relating to the age of assessing adversity effects, measures to quantify stress and inflammation, and more brain-based measures of biochemistry. Preclinical studies pave the way for interventions using anti-inflammation-based agents (COX-2 inhibitors, CB2 agonists, meditation/yoga) by identifying where, when, and how the developmental trajectory goes awry.

Sustained TNF signaling is required for the synaptic and anxiety-like behavioral response to acute stress

Acute stress triggers plasticity of forebrain synapses as well as behavioral changes. Here we reveal that Tumor Necrosis Factor α (TNF) is a required downstream mediator of the stress response in mice, necessary for stress-induced synaptic potentiation in the ventral hippocampus and for an increase in anxiety-like behaviour. Acute stress is sufficient to activate microglia, triggering the long-term release of TNF. Critically, on-going TNF signaling specifically in the ventral hippocampus is necessary to sustain both the stress-induced synaptic and behavioral changes, as these could be reversed hours after induction by antagonizing TNF signaling. This demonstrates that TNF maintains the synaptic and behavioral stress response in vivo, making TNF a potential novel therapeutic target for stress disorders.

Stress-induced depressive-like behavior in male rats is associated with microglial activation and inflammation dysregulation in the hippocampus in adulthood

Neuroinflammation is increasingly recognized as playing a critical role in depression. Early-life stress exposure and constitutive differences in glucocorticoid responsiveness to stressors are two key risk factors for depression, but their impacts on the inflammatory status of the brain is still uncertain. Moreover, there is a need to identify specific molecules involved in these processes with the potential to be used as alternative therapeutic targets in inflammation-related depression. Here, we studied how peripubertal stress (PPS) combined with differential corticosterone (CORT)-stress responsiveness (CSR) influences depressive-like behaviors and brain inflammatory markers in male rats in adulthood, and how these alterations relate to microglia activation and miR-342 expression. We found that high-CORT stress-responsive (H-CSR) male rats that underwent PPS exhibited increased anhedonia and passive coping responses in adulthood. Also, animals exposed to PPS showed increased hippocampal TNF-α expression, which positively correlated with passive coping responses. In addition, PPS caused long-term effects on hippocampal microglia, particularly in H-CSR rats, with increased hippocampal IBA-1 expression and morphological alterations compatible with a higher degree of activation. H-CSR animals also showed upregulation of hippocampal miR-342, a mediator of TNF-α-driven microglial activation, and its expression was positively correlated with TNF-α expression, microglial activation and passive coping responses. Our findings indicate that individuals with constitutive H-CSR are particularly sensitive to developing protracted depression-like behaviors following PPS exposure. In addition, they show neuro-immunological alterations in adulthood, such as increased hippocampal TNF-α expression, microglial activation and miR-342 expression. Our work highlights miR-342 as a potential therapeutic target in inflammation-related depression.

Modulation of nociception and pain-evoked neurobehavioral responses by levetiracetam in a craniotomy pain model

Traditional and novel analgesic modalities have been extensively tested for post-craniotomy pain management, yet the role of newer antiepileptic drugs in this area remains obscure. This study investigates the impact of levetiracetam (LEV) on pain modulation and neurobehavioral performance in a craniotomy model. Fifty-six Wistar rats were randomly assigned into seven groups: no intervention (CTRL), administration of placebo or LEV with no further intervention (PBO and LEV, respectively), and sham-operation or craniotomy in placebo (PBO-SHAM and PBO-CR, respectively) or LEV-treated rats (LEV-SHAM and LEV-CR, respectively). Pain was assessed by the rat grimace scale before, and at 8 and 24 h after craniotomy, following intraperitoneal injections of LEV (100 mg/kg twice daily) or normal saline two consecutive days before and on the craniotomy day. Elevated plus-maze and olfactory social memory tests were performed at 24- and 48 h post-craniotomy, respectively. Upon testing conclusion blood samples were collected for cytokines estimation. Levetiracetam administration enhanced antinociception in sham and craniotomy groups. In the elevated plus-maze test, LEV-CR rats spent more time in investigating open arms and performed more open arm entries than PBO-SHAM and PBO-CR animals. The olfactory test revealed no between-groups difference in acquisition time during first contact with a juvenile rat, while LEV-CR rats spent less time to recognize the same juvenile rat compared to PBO-SHAM and PBO-CR groups. Furthermore, LEV-treatment attenuated cortisol, interleukin-6 and TNF-a release, in sham and craniotomy animals. In conclusion, preemptive use of LEV decreases nociception, improves pain-evoked behavior and attenuates stress response in rats subjected to craniotomy.

Do epidermal keratinocytes have sensory and information processing systems?

It was long considered that the role of epidermal keratinocytes is solely to construct a water-impermeable protective membrane, the stratum corneum, at the uppermost layer of the skin. However, in the last two decades, it has been found that keratinocytes contain multiple sensory systems that detect environmental changes, including mechanical stimuli, sound, visible radiation, electric fields, magnetic fields, temperature and chemical stimuli, and also a variety of receptor molecules associated with olfactory or taste sensation. Moreover, neurotransmitters and their receptors that play crucial roles in the brain are functionally expressed in keratinocytes. Recent studies have demonstrated that excitation of keratinocytes can induce sensory perception in the brain. Here, we review the sensory and information processing capabilities of keratinocytes. We discuss the possibility that epidermal keratinocytes might represent the earliest stage in the development of the brain during the evolution of vertebrates.

Medical students' positive perception towards vaccination is strongly correlated to protective diphtheria antibody after Td vaccination

Negative perception towards vaccination is one of the reasons for low coverage of diphtheria immunization in Indonesia. Perception, which is difficult to change, is related to stress level, possibly influences outcome of diseases, and also vaccination. This study aims to identify the correlation between perception of diphtheria vaccination and antibody response after vaccination. This study used secondary data from two unpublished studies on 30 medical interns in Hasan Sadikin Hospital, Bandung, West Java, after diphtheria outbreak, from June to July 2019. Antibody level after diphtheria emergency vaccination was measured using ELISA and perception towards vaccination was measured using a questionnaire. Perception towards vaccination was expressed as perception score and was divided into 4 components: perceived threat, benefit, barrier, and cues to action. Higher perception score indicated more positive perception towards vaccination. Diphtheria antibody level was grouped into reliable protection (≥0,10 IU/mL) or unreliable protection (<0,10 IU/mL). Statistical correlation analysis was done with GraphPad Prism version 7.0. Most of our subjects were female. Median age was 22 (20-24) years old. Median time elapsed between vaccination date and measurement of antibody level was 18 (6-18) months. Median antibody level was 0,28 (0,09-3,47) IU/mL. Twenty-three subjects (82,1%) had reliable protection. Subjects with reliable protection had more positive perception compared to unreliable protection (perception score 80,6 ​± ​5,4 vs 69,0 ​± ​1,8, p ​= ​0,0001). Subjects with reliable protection had less perceived barrier for vaccination (15,6 ​± ​2,1 vs 13,0 ​± ​1,8, p ​= ​0,0083). Perception score showed strong, positive correlation to reliable protection against diphtheria (R ​= ​0,705, p ​< ​0,001). Perceived barrier and threat showed positive correlation to reliable protection (R ​= ​0,489, p ​= ​0,008 and R ​= ​0,402, p ​= ​0,034). In conclusion, perception towards diphtheria vaccination is strongly correlated to protective antibody. Improving perception of vaccination are needed to overcome vaccine hesitancy.

Regulatory effect of vitamin D on pro-inflammatory cytokines and anti-oxidative enzymes dysregulations due to chronic mild stress in the rat hippocampus and prefrontal cortical area

BACKGROUND

Chronic stress increases the production of pro-inflammatory cytokines and oxidative stress in the brain, which underlay cognitive and psychological problems. In addition to the anti-depressants, vitamin D is known to act as an anti-inflammatory and anti-oxidative agent. This study investigates the specific effects of vitamin D in protecting hippocampus and pre-frontal cortex (PFC) against chronic mild stress (CMS)-induced activation of pro-inflammatory cytokines IL-6 and TNF-α and decreasing the activation of anti-oxidative enzymes super oxide dismutase (SOD) and glutathione peroxidase (GPx).

METHODS AND RESULTS

Rats were exposed to CMS for 3 weeks. Two groups of rats received vitamin D (5 and 10 μg/kg) and another received fluoxetine (5 mg/kg) along with CMS. Control groups were not exposed to CMS, but received treatments similar to CMS groups. Serum corticosterone and IL-6, TNF-α and SOD and GPx levels in the hippocampus and PFC were measured at the end of three weeks. CMS significantly increased corticosterone, IL-6, TNF-α and decreased SOD and GPx levels (P < 0.0001) in hippocampus and PFC. Vitamin D treatment reduced corticosterone levels (P < 0.01), increased SOD (P < 0.0001) and GPx (P < 0.01) and decreased IL-6 and TNF-α (P < 0.0001) levels in the hippocampus and PFC compared to rats treated with vitamin D vehicle. Vitamin D-10 regulation of SOD and IL-6 levels was more effective than fluoxetine (P < 0.0001 and P < 0.01, respectively, in hippocampus).

CONCLUSION

This study suggests that vitamin D effectively protects the key regions of the brain related to cognition and affective behavior, against the inflammation and oxidative stress caused by the chronic stress.

Long-term effects of stress resilience: Hippocampal neuroinflammation and behavioral approach in male rats

Resilience to stress is the ability to quickly adapt to adversity. There is evidence that exposure to prolonged stress triggers neuroinflammation what produces individual differences in stress vulnerability. However, the relationship between stress resilience, neuroinflammation, and depressive-like behaviors remains unknown. The aim of this study was to analyze the long-term effects of social defeat stress (SDS) on neuroinflammation in the hippocampus and depressive-like behaviors. Male rats were subjected to the SDS paradigm. Social interaction was analyzed 1 and 2 weeks after ending the SDS to determine which animals were susceptible or resilient to stress. Neuroinflammation markers glial fibrillary acidic protein, ionized calcium-binding adaptor molecule 1, and elevated membrane permeability in astrocytes and microglia, as well as depressive-like behaviors in the sucrose preference test and forced swim test were evaluated in all rats. One week after SDS, resilient rats increased their sucrose preference, and time spent in the floating behavior decreased in the forced swim test compared to susceptible rats. Surprisingly, resilient rats became susceptible to stress, and presented neuroinflammation 2 weeks after SDS. These findings suggest that SDS-induced hippocampal neuroinflammation persists in post-stress stages, regardless of whether rats were initially resilient or not. Our study opens a new approach to understanding the neurobiology of stress resilience.

Microglia and BDNF at the crossroads of stressor related disorders: Towards a unique trophic phenotype

Stressors ranging from psychogenic/social to neurogenic/injury to systemic/microbial can impact microglial inflammatory processes, but less is known regarding their effects on trophic properties of microglia. Recent studies do suggest that microglia can modulate neuronal plasticity, possibly through brain derived neurotrophic factor (BDNF). This is particularly important given the link between BDNF and neuropsychiatric and neurodegenerative pathology. We posit that certain activated states of microglia play a role in maintaining the delicate balance of BDNF release onto neuronal synapses. This focused review will address how different "activators" influence the expression and release of microglial BDNF and address the question of tropomyosin receptor kinase B (TrkB) expression on microglia. We will then assess sex-based differences in microglial function and BDNF expression, and how microglia are involved in the stress response and related disorders such as depression. Drawing on research from a variety of other disorders, we will highlight challenges and opportunities for modulators that can shift microglia to a "trophic" phenotype with a view to potential therapeutics relevant for stressor-related disorders.

Contributions of Ergonomics, Psychological Factors, and Sleep Disturbances to Lower Back Pain Among Taiwanese Workers

OBJECTIVE

We investigated the contributions of ergonomics, psychological factors, and sleep disturbances to lower back pain (LBP).

METHODS

A nationwide survey of sampled 27,508 (2.6‰) Taiwanese workers was conducted in 2010. Definition of outcome was LBP affecting work performance in the past year. Predictor variables included age, body mass index, ergonomic factors, job control, psychological demands, and sleep disturbances. Mutually adjusted relative risks were examined using general linear models, followed by aPAR.

RESULTS

18,353 workers were included in the multivariate regression model. The three first significant risk factors to LBP included heavy lifting or awkward posture, sleep disturbances, and high psychological demands (aPAR = 13.5%, 8.7%, 5.7% respectively in men and 6.1%, 11.8%, 5.9% in women).

CONCLUSIONS

In addition to ergonomic exposure, sleep disturbances and high psychological demands significantly contributed to LBP.

Calorie Restriction as a New Treatment of Inflammatory Diseases

Immoderate calorie intake coupled with a sedentary lifestyle are major determinants of health issues and inflammatory diseases in modern society. The balance between energy consumption and energy expenditure is critical for longevity. Excessive energy intake and adiposity cause systemic inflammation, whereas calorie restriction (CR) without malnutrition, exerts a potent anti-inflammatory effect. The objective of this review was to provide an overview of different strategies used to reduce calorie intake, discuss physiological mechanisms by which CR might lead to improved health outcomes, and summarize the present knowledge about inflammatory diseases. We discuss emerging data of observational studies and randomized clinical trials on CR that have been shown to reduce inflammation and improve human health.

The Impact of Obesity on Microglial Function: Immune, Metabolic and Endocrine Perspectives

Increased life expectancy in combination with modern life style and high prevalence of obesity are important risk factors for development of neurodegenerative diseases. Neuroinflammation is a feature of neurodegenerative diseases, and microglia, the innate immune cells of the brain, are central players in it. The present review discusses the effects of obesity, chronic peripheral inflammation and obesity-associated metabolic and endocrine perturbations, including insulin resistance, dyslipidemia and increased glucocorticoid levels, on microglial function.

Neuroinflammation and Neuronal Loss in the Hippocampus Are Associated with Immediate Posttraumatic Seizures and Corticosterone Elevation in Rats

Hippocampal damage after traumatic brain injury (TBI) is associated with late posttraumatic conditions, such as depression, cognitive decline and epilepsy. Mechanisms of selective hippocampal damage after TBI are not well understood. In this study, using rat TBI model (lateral fluid percussion cortical injury), we assessed potential association of immediate posttraumatic seizures and changes in corticosterone (CS) levels with neuroinflammation and neuronal cell loss in the hippocampus. Indices of distant hippocampal damage (neurodegeneration and neuroinflammation) were assessed using histological analysis (Nissl staining, Iba-1 immunohistochemical staining) and ELISA (IL-1β and CS) 1, 3, 7 and 14 days after TBI or sham operation in male Wistar rats (n = 146). IL-1β was elevated only in the ipsilateral hippocampus on day 1 after trauma. CS peak was detected on day 3 in blood, the ipsilateral and contralateral hippocampus. Neuronal cell loss in the hippocampus was demonstrated bilaterally; in the ipsilateral hippocampus it started earlier than in the contralateral. Microglial activation was evident in the hippocampus bilaterally on day 7 after TBI. The duration of immediate seizures correlated with CS elevation, levels of IL-1β and neuronal loss in the hippocampus. The data suggest potential association of immediate post-traumatic seizures with CS-dependent neuroinflammation-mediated distant hippocampal damage.

The Potential Mechanisms of High-Velocity, Low-Amplitude, Controlled Vertebral Thrusts on Neuroimmune Function: A Narrative Review

The current COVID-19 pandemic has necessitated the need to find healthcare solutions that boost or support immunity. There is some evidence that high-velocity, low-amplitude (HVLA) controlled vertebral thrusts have the potential to modulate immune mediators. However, the mechanisms of the link between HVLA controlled vertebral thrusts and neuroimmune function and the associated potential clinical implications are less clear. This review aims to elucidate the underlying mechanisms that can explain the HVLA controlled vertebral thrust--neuroimmune link and discuss what this link implies for clinical practice and future research needs. A search for relevant articles published up until April 2021 was undertaken. Twenty-three published papers were found that explored the impact of HVLA controlled vertebral thrusts on neuroimmune markers, of which eighteen found a significant effect. These basic science studies show that HVLA controlled vertebral thrust influence the levels of immune mediators in the body, including neuropeptides, inflammatory markers, and endocrine markers. This narravtive review discusses the most likely mechanisms for how HVLA controlled vertebral thrusts could impact these immune markers. The mechanisms are most likely due to the known changes in proprioceptive processing that occur within the central nervous system (CNS), in particular within the prefrontal cortex, following HVLA spinal thrusts. The prefrontal cortex is involved in the regulation of the autonomic nervous system, the hypothalamic-pituitary-adrenal axis and the immune system. Bi-directional neuro-immune interactions are affected by emotional or pain-related stress. Stress-induced sympathetic nervous system activity also alters vertebral motor control. Therefore, there are biologically plausible direct and indirect mechanisms that link HVLA controlled vertebral thrusts to the immune system, suggesting HVLA controlled vertebral thrusts have the potential to modulate immune function. However, it is not yet known whether HVLA controlled vertebral thrusts have a clinically relevant impact on immunity. Further research is needed to explore the clinical impact of HVLA controlled vertebral thrusts on immune function.

A deep insight into pelvic pain and endometriosis: a review of the literature from pathophysiology to clinical expressions

Endometriosis is a chronic inflammatory disease that affects approximately 10% of women of reproductive age. Its clinical manifestations are highly heterogeneous, but pelvic pain is the most frequent, causing functional disability. Cyclic or acyclic chronic pelvic pain (CPP), dysmenorrhea and dyspareunia are frequent symptoms which often compromise all aspects of the women's quality of life (QoL). The pathophysiology of endometriosis-related pain is extremely complex and not always clear. The aim of this literature review is to focus on recent updates on the clinical presentation, the pathophysiology and the most important mechanisms involved in the pathogenesis of pelvic pain in endometriosis. A literature search in the Cochrane library, PubMed, Scopus and web of Science databases has been performed, identifying articles from January 1995 to November 2020. Several processes seem to be involved in the pathogenesis of pain, but many aspects are still unclear. Scientific evidence has shown that a correlation between pain severity and stage of endometriosis rarely occurs, whereas there is a significant correlation between pain and the presence of deep endometriosis. Onset and intensity of pain may be due to a complex process involving central sensitization and peripheral activation of nociceptive pathways as well as dysfunction of the immune system and of the hypothalamic-pituitary-adrenal (HPA) axis. A deeper understanding of these different pathogenetic mechanisms may improve future treatments in women with painful endometriosis.

Role of Non-Coding Regulatory Elements in the Control of GR-Dependent Gene Expression

The glucocorticoid receptor (GR, also known as NR3C1) coordinates molecular responses to stress. It is a potent transcription activator and repressor that influences hundreds of genes. Enhancers are non-coding DNA regions outside of the core promoters that increase transcriptional activity via long-distance interactions. Active GR binds to pre-existing enhancer sites and recruits further factors, including EP300, a known transcriptional coactivator. However, it is not known how the timing of GR-binding-induced enhancer remodeling relates to transcriptional changes. Here we analyze data from the ENCODE project that provides ChIP-Seq and RNA-Seq data at distinct time points after dexamethasone exposure of human A549 epithelial-like cell line. This study aimed to investigate the temporal interplay between GR binding, enhancer remodeling, and gene expression. By investigating a single distal GR-binding site for each differentially upregulated gene, we show that transcriptional changes follow GR binding, and that the largest enhancer remodeling coincides in time with the highest gene expression changes. A detailed analysis of the time course showed that for upregulated genes, enhancer activation persists after gene expression changes settle. Moreover, genes with the largest change in EP300 binding showed the highest expression dynamics before the peak of EP300 recruitment. Overall, our results show that enhancer remodeling may not directly be driving gene expression dynamics but rather be a consequence of expression activation.

On the therapeutic targets and pharmacological treatments for pain relief following spinal cord injury: A mechanistic review

Spinal cord injury (SCI) is globally considered as one of the most debilitating disorders, which interferes with daily activities and life of the affected patients. Despite many developments in related recognizing and treating procedures, post-SCI neuropathic pain (NP) is still a clinical challenge for clinicians with no distinct treatments. Accordingly, a comprehensive search was conducted in PubMed, Medline, Scopus, Web of Science, and national database (SID and Irandoc). The relevant articles regarding signaling pathways, therapeutic targets and pharmacotherapy of post-SCI pain were also reviewed. Data were collected with no time limitation until November 2020. The present study provides the findings on molecular mechanisms and therapeutic targets, as well as developing the critical signaling pathways to introduce novel neuroprotective treatments of post-SCI pain. From the pathophysiological mechanistic point of view, post-SCI inflammation activates the innate immune system, in which the immune cells elicit secondary injuries. So, targeting the critical signaling pathways for pain management in the SCI population has significant importance in providing new treatments. Indeed, several receptors, ion channels, excitatory neurotransmitters, enzymes, and key signaling pathways could be used as therapeutic targets, with a pivotal role of n-methyl-D-aspartate, gamma-aminobutyric acid, and inflammatory mediators. The current review focuses on conventional therapies, as well as crucial signaling pathways and promising therapeutic targets for post-SCI pain to provide new insights into the clinical treatment of post-SCI pain. The need to develop innovative delivery systems to treat SCI is also considered.

Co-culture of monocytes and zona fasciculata adrenal cells: An in vitro model to study the immune-adrenal cross-talk

The hypothalamic-pituitary-adrenal axis is the primary neuroendocrine system activated to re-establish homeostasis during periods of stress, including critical illness and major surgery. During critical illness, evidence suggests that locally induced inflammation of the adrenal gland could facilitate immune-adrenal cross-talk and, in turn, modulate cortisol secretion. It has been hypothesized that immune cells are necessary to mediate the effect of inflammatory stimuli on the steroidogenic pathway that has been observed in vivo. To test this hypothesis, we developed and characterized a trans-well co-culture model of THP1 (human monocytic cell)-derived macrophages and ATC7 murine zona fasciculata adrenocortical cells. We found that co-culture of ATC7 and THP1 cells results in a significant increase in the basal levels of IL-6 mRNA in ATC7 cells, and this effect was potentiated by treatment with LPS. Addition of LPS to co-cultures of ATC7 and THP1 significantly decreased the expression of key adrenal steroidogenic enzymes (including StAR and DAX-1), and this was also found in ATC7 cells treated with pro-inflammatory cytokines. Moreover, 24-h treatment with the synthetic glucocorticoid dexamethasone prevented the effects of LPS stimulation on IL-6, StAR and DAX-1 mRNA in ATC7 cells co-cultured with THP1 cells. Our data suggest that the expression of IL-6 and steroidogenic genes in response to LPS depends on the activation of intra-adrenal immune cells. Moreover, we also show that the effects of LPS can be modulated by glucocorticoids in a time- and dose-dependent manner with potential implications for clinical practice.

Altered acoustic startle, prepulse facilitation, and object recognition memory produced by corticosterone withdrawal in male rats

The symptoms of human depression often include cognitive deficits. However, cognition is not frequently included in the behavioral assessments conducted in preclinical models of depression. For example, it is well known that repeated corticosterone (CORT) injections in rodents produce depression-like behavior as measured by the forced swim test, sucrose preference test, and tail suspension test, but the cognitive impairments produced by repeated CORT have not been thoroughly examined. The purpose of this experiment was to assess the effect of repeated CORT injections on several versions of object recognition memory and modulation of the acoustic startle response by relatively low intensity prepulses, along with the more traditional assessment of depression-like behavior using the forced swim test. Rats received 21 days of CORT (40 mg/kg) or vehicle injections followed by a battery of behavioral tests. Importantly, during behavioral testing CORT treatment did not occur (CORT withdrawal). Corticosterone decreased body weight, increased immobility in the forced swim test, lowered startle amplitudes, and facilitated responding to trials with a short interval (30 ms) between the prepulse and pulse. Corticosterone also impaired both object location and object-in-place recognition memory, while sparing performance on object recognition memory. Collectively, our data suggest that CORT produces selective disruptions in prepulse facilitation, object location, and object-in-place recognition memory, and that these impairments should be considered as part of the phenotype produced by repeated CORT, and perhaps chronic stress.

What Does CATS Have to Do With Cancer? The Cognitive Activation Theory of Stress (CATS) Forms the SURGE Model of Chronic Post-surgical Pain in Women With Breast Cancer

Chronic post-surgical pain (CPSP) represents a highly prevalent and significant clinical problem. Both major and minor surgeries entail risks of developing CPSP, and cancer-related surgery is no exception. As an example, more than 40% of women undergoing breast cancer surgery struggle with CPSP years after surgery. While we do not fully understand the pathophysiology of CPSP, we know it is multifaceted with biological, social, and psychological factors contributing. The aim of this review is to advocate for the role of response outcome expectancies in the development of CPSP following breast cancer surgery. We propose the Cognitive Activation Theory of Stress (CATS) as an applicable theoretical framework detailing the potential role of cortisol regulation, inflammation, and inflammatory-induced sickness behavior in CPSP. Drawing on learning theory and activation theory, CATS offers psychobiological explanations for the relationship between stress and health, where acquired expectancies are crucial in determining the stress response and health outcomes. Based on existing knowledge about risk factors for CPSP, and in line with the CATS position, we propose the SURGEry outcome expectancy (SURGE) model of CPSP. According to SURGE, expectancies impact stress physiology, inflammation, and fear-based learning influencing the development and persistence of CPSP. SURGE further proposes that generalized response outcome expectancies drive adaptive or maladaptive stress responses in the time around surgery, where coping dampens the stress response, while helplessness and hopelessness sustains it. A sustained stress response may contribute to central sensitization, alterations in functional brain networks and excessive fear-based learning. This sets the stage for a prolonged state of inflammatory-induced sickness behavior - potentially driving and maintaining CPSP. Finally, as psychological factors are modifiable, robust and potent predictors of CPSP, we suggest hypnosis as an effective intervention strategy targeting response outcome expectancies. We here argue that presurgical clinical hypnosis has the potential of preventing CPSP in women with breast cancer.

Glucocorticoids, metabolism and brain activity

The review integrates different experimental approaches including biochemistry, c-Fos expression, microdialysis (glutamate, GABA, noradrenaline and serotonin), electrophysiology and fMRI to better understand the effect of elevated level of glucocorticoids on the brain activity and metabolism. The available data indicate that glucocorticoids alter the dynamics of neuronal activity leading to context-specific changes including both excitation and inhibition and these effects are expected to support the task-related responses. Glucocorticoids also lead to diversification of available sources of energy due to elevated levels of glucose, lactate, pyruvate, mannose and hydroxybutyrate (ketone bodies), which can be used to fuel brain, and facilitate storage and utilization of brain carbohydrate reserves formed by glycogen. However, the mismatch between carbohydrate supply and utilization that is most likely to occur in situations not requiring energy-consuming activities lead to metabolic stress due to elevated brain levels of glucose. Excessive doses of glucocorticoids also impair the production of energy (ATP) and mitochondrial oxidation. Therefore, glucocorticoids have both adaptive and maladaptive effects consistently with the concept of allostatic load and overload.

Mindful Nonreactivity Moderates the Relationship between Chronic Stress and Pain Interference in Law Enforcement Officers

INTRODUCTION

With high levels of both chronic stress and chronic pain, law enforcement provides a unique population in which to study the potential mitigating impact of cognitive and affective reactivity on the stress-pain link. The primary aim of the present study was to examine the moderating role of mindful nonreactivity in the relationship between chronic stress and pain interference in law enforcement officers (n = 60).

METHODS

A regression analysis was conducted to determine if chronic stress predicted pain interference, and subsequently, to compute an estimate of the interaction effect of the chronic stress and mindful nonreactivity on pain interference.

RESULTS

Results demonstrated the overall model was significant, F (3,55) = 5.29, p =.003, R2 = .47. When controlling for mindful nonreactivity, chronic stress significantly predicted pain interference, b = .76, t (55) = 3.40, p = .001, such that every one unit increase in chronic stress was associated with a .76 unit increase in pain interference. Results also demonstrated a significant interaction effect of mindful nonreactivity and chronic stress on pain interference, b = -.04, t (55) = -2.86, p = .006. The Johnson-Neyman technique was conducted and revealed among individuals with low levels of mindful nonreactivity, chronic stress significantly predicted pain interference. However, for individuals with greater levels of mindful nonreactivity, chronic stress no longer predicted pain interference.

CONCLUSIONS

Findings contribute to a growing understanding of how mindfulness can mitigate harmful effects of stress.

Neuroimmune Response Mediated by Cytokines in Natural Scrapie after Chronic Dexamethasone Treatment

The actual role of prion protein-induced glial activation and subsequent cytokine secretion during prion diseases is still incompletely understood. The overall aim of this study is to assess the effect of an anti-inflammatory treatment with dexamethasone on different cytokines released by neuroglial cells that are potentially related to neuroinflammation in natural scrapie. This study emphasizes the complex interactions existent among several pleiotropic neuromodulator peptides and provides a global approach to clarify neuroinflammatory processes in prion diseases. Additionally, an impairment of communication between microglial and astroglial populations mediated by cytokines, mainly IL-1, is suggested. The main novelty of this study is that it is the first one assessing in situ neuroinflammatory activity in relation to chronic anti-inflammatory therapy, gaining relevance because it is based on a natural model. The cytokine profile data would suggest the activation of some neurotoxicity-associated route. Consequently, targeting such a pathway might be a new approach to modify the damaging effects of neuroinflammation.

Familial Mediterranean fever: the molecular pathways from stress exposure to attacks

FMF is an autoinflammatory disease characterized by recurrent attacks and increased IL-1 synthesis owing to activation of the pyrin inflammasome. Although knowledge of the mechanisms leading to the activation of pyrin inflammasome is increasing, it is still unknown why the disease is characterized by attack. The emergence of FMF attacks after emotional stress and the induction of attacks with metaraminol in previous decades suggested that stress-induced sympathoadrenal system activation might play a role in inflammasome activation and triggering attacks. In this review, we will review the possible molecular mechanism of stress mediators on the inflammation pathway and inflammasome activation. Studies on stress mediators and their impact on inflammation pathways will provide a better understanding of stress-related exacerbation mechanisms in both autoinflammatory and autoimmune diseases. This review provides a new perspective on this subject and will contribute to new studies.

Paliperidone attenuates chronic stress-induced changes in the expression of inflammasomes-related protein in the frontal cortex of male rats

Several stress-related neuropsychiatric diseases are related to inflammatory phenomena. Thus, a better understanding of stress-induced immune responses could lead to enhanced treatment alternatives. Little is known about the possible involvement of inflammasomes in the stress-induced proinflammatory response. Antipsychotics have anti-inflammatory effects, but the possible antipsychotic treatment actions on inflammasomes remain unexplored. Our aim was to study whether inflammasomes are involved in the neuroinflammation induced by a paradigmatic model of chronic stress and whether the monoamine receptor antagonist paliperidone can modulate the possible stress-induced inflammasomes activation in the frontal cortex (FC). Thus, the effects of paliperidone (1 mg/Kg, oral gavage) administered during a chronic restraint stress protocol (6 h/day for 21 days) on the possible stress-related inflammasomes protein induction were evaluated through Western blot in the FC of male Wistar rats. Stress increased protein expression levels of the inflammasome complexes NALP1, NLRP3 and AIM2 and augmented caspase-1 and mature interleukin (IL)-1β protein levels. Paliperidone pre-treatment normalized the protein expression of the inflammasome pathway. In conclusion, our data indicate an induction of inflammasome complexes by chronic restraint stress in the FC of rats. The antipsychotic paliperidone has an inhibitory action on some of the stress-induced inflammasomes stimulation trying to normalize the neuroinflammatory scenario caused by stress. Considering the emerging role of inflammation in neuropsychiatric diseases, the development of new drugs targeting inflammasome pathways is a promising approach for future therapeutic interventions.

Noradrenaline as a key neurotransmitter in modulating microglial activation in stress response

State of mind can influence susceptibility and progression of diseases and disorders not only in peripheral organs, but also in the central nervous system (CNS). However, the underlying mechanism how state of mind can affect susceptibility to various illnesses in the CNS is not fully understood. Among a number of candidates responsible for stress-induced neuroimmunomodulation, noradrenaline has recently been shown to play crucial roles in the major immune cells of the brain, microglia. In particular, recent studies have demonstrated that noradrenaline may be a key neurotransmitter in modulating microglial cells, thereby determining different cell conditions and responses ranging from resting to activation state depending on host stress level or whether the host is awake or asleep. For instance, microglia under resting conditions may have constructive roles in surveillance, such as debris clearance, synaptic monitoring, pruning, and remodeling. In contrast, once activated, microglia may become less efficient in surveillance activities, and instead implicated in detrimental roles such as cytokine or superoxide release. It is also likely that glial activation, both astrocytes and microglia, are negatively associated with the clearance of brain waste via the glymphatic system. In this review, we discuss the possible underlying mechanism as well as the roles of stress-induced microglial activation.

Discrimination and systemic inflammation: A critical review and synthesis

Exposure to discrimination or unfair treatment has emerged as an important risk factor for illness and disease that disproportionately affects racial and ethnic minorities. Discriminatory experiences may operate like other stressors in that they activate physiological responses that adversely affect the maintenance of homeostasis. Research suggests that inflammation plays a critical role in the pathophysiology of stress-related diseases. Recent findings on discrimination and inflammation are discussed. We highlight limitations in the current evidence and provide recommendations for future studies that seek to examine the association between discrimination and inflammation.

Emotional Traumatic Brain Injury

The definition of traumatic brain injury (TBI) has expanded to include mild TBI and postconcussive syndrome. This evolution has resulted in difficulty disentangling the physical trauma of mild TBI from the emotional trauma of posttraumatic stress disorder (PTSD). Advances in stress neurobiology and knowledge of brain injury at the macroscopic, microscopic, biochemical, and molecular levels call for a redefinition of TBI that encompasses both physical and emotional TBI. Conceptualizing a spectrum of TBI with both physical and emotional causation resolves the irreconcilable tangle between diagnostic categories and acknowledges overlapping forms of brain injury and shared systemic effects due to hormonal and inflammatory mediators. Recognizing emotional TBI shifts the interpretation of emotional trauma from a confound to a comorbid, related cause of brain injury. The mechanism of emotional TBI includes the intricate actions of stress hormones on diverse brain functions due to changes in synaptic plasticity, where chronically elevated hormone levels reduce neurogenesis, resulting in dendritic atrophy and impaired cognition. The overlapping effects of physical and emotional trauma are seen in neuropathology (ie, reduction of hippocampal volume in TBI and PTSD); fMRI (similar regional activations in physical and emotional pain); and systemic sequelae, including changes in proinflammatory cytokine levels and immune cell function. Accumulating evidence favors a change in the definition of TBI to encompass emotional TBI. The definition of TBI will be strengthened by the inclusion of both physical and emotional trauma that result in diverse and overlapping forms of brain injury with sequelae for physical and mental health.

Neuroinflammation-Associated Alterations of the Brain as Potential Neural Biomarkers in Anxiety Disorders

Stress-induced changes in the immune system, which lead to neuroinflammation and consequent brain alterations, have been suggested as possible neurobiological substrates of anxiety disorders, with previous literature predominantly focusing on panic disorder, agoraphobia, and generalized anxiety disorder, among the anxiety disorders. Anxiety disorders have frequently been associated with chronic stress, with chronically stressful situations being reported to precipitate the onset of anxiety disorders. Also, chronic stress has been reported to lead to hypothalamic–pituitary–adrenal axis and autonomic nervous system disruption, which may in turn induce systemic proinflammatory conditions. Preliminary evidence suggests anxiety disorders are also associated with increased inflammation. Systemic inflammation can access the brain, and enhance pro-inflammatory cytokine levels that have been shown to precipitate direct and indirect neurotoxic effects. Prefrontal and limbic structures are widely reported to be influenced by neuroinflammatory conditions. In concordance with these findings, various imaging studies on panic disorder, agoraphobia, and generalized anxiety disorder have reported alterations in structure, function, and connectivity of prefrontal and limbic structures. Further research is needed on the use of inflammatory markers and brain imaging in the early diagnosis of anxiety disorders, along with the possible efficacy of anti-inflammatory interventions on the prevention and treatment of anxiety disorders.

Neuroimmune Response in Natural Preclinical Scrapie after Dexamethasone Treatment

A recently published report on chronic dexamethasone treatment for natural scrapie supported the hypothesis of the potential failure of astroglia in the advanced stage of disease. Herein, we aimed to extend the aforementioned study on the effect of this anti-inflammatory therapy to the initial phase of scrapie, with the aim of elucidating the natural neuroinflammatory process occurring in this neurodegenerative disorder. The administration of this glucocorticoid resulted in an outstanding reduction in vacuolation and aberrant protein deposition (nearly null), and an increase in glial activation. Furthermore, evident suppression of IL-1R and IL-6 and the exacerbation of IL-1α, IL-2R, IL-10R and IFNγR were also demonstrated. Consequently, the early stage of the disease is characterized by an intact neuroglial response similar to that of healthy individuals attempting to re-establish homeostasis. A complex network of neuroinflammatory markers is involved from the very early stages of this prion disease, which probably becomes impaired in the more advanced stages. The in vivo animal model used herein provides essential observations on the pathogenesis of natural scrapie, as well as the possibility of establishing neuroglia as potential target cells for anti-inflammatory therapy.

The Gut Microbiome Regulates Psychological-Stress-Induced Inflammation

Psychological stress has adverse effects on various human diseases, including those of the cardiovascular system. However, the mechanisms by which stress influences disease activity remain unclear. Here, using vaso-occlusive episodes (VOEs) of sickle cell disease as a vascular disease model, we show that stress promotes VOEs by eliciting a glucocorticoid hormonal response that augments gut permeability, leading to microbiota-dependent interleukin-17A (IL-17A) secretion from T helper 17 (Th17) cells of the lamina propria, followed by the expansion of the circulating pool of aged neutrophils that trigger VOEs. We identify segmented filamentous bacteria as the commensal essential for the stress-induced expansion of aged neutrophils that enhance VOEs in mice. Importantly, the inhibition of glucocorticoids synthesis, blockade of IL-17A, or depletion of the Th17 cell-inducing gut microbiota markedly reduces stress-induced VOEs. These results offer potential therapeutic targets to limit the impact of psychological stress on acute vascular occlusion.

Glucocorticoids prime the inflammatory response of human hippocampal cells through up-regulation of inflammatory pathways

Increased pro-inflammatory cytokines and an overactive hypothalamic-pituitary-adrenal (HPA) axis have both been implicated in the pathogenesis of depression. However, these explanations appear contradictory because glucocorticoids are well recognised for their anti-inflammatory effects. Two hypotheses exist to resolve this paradox: the mediating presence of glucocorticoid receptor resistance, or the possibility that glucocorticoids can potentiate inflammatory processes in some circumstances. We sought to investigate these hypotheses in a cell model with significant relevance to depression: human hippocampal progenitor cells. We demonstrated that dexamethasone in vitro given for 24 hours and followed by a 24 hours rest interval before an immune challenge potentiates inflammatory effects in these neural cells, that is, increases the IL-6 protein secretion induced by stimulation with IL-1β (10 ng/mL for 24 hours) by + 49% (P < 0.05) at a concentration of 100 nM and by + 70% (P < 0.01) for 1 μM. These effects are time- and dose-dependent and require activation of the glucocorticoid receptor. Gene expression microarray assays using Human Gene 2.1st Array Strips demonstrated that glucocorticoid treatment up-regulated several innate immune genes, including chemokines and Nod-like receptor, NLRP6; using transcription factor binding motifs we found limited evidence that glucocorticoid resistance was induced in the cells. Our data suggests a mechanism by which stress may prime the immune system for increased inflammation and suggests that stress and inflammation may be synergistic in the pathogenesis of depression.

Steroid-Induced Sleep Disturbance and Delirium: A Focused Review for Critically Ill Patients

OBJECTIVE

Insomnia and delirium have gained much attention since the publication of recent guidelines for the management in critically ill adults. Neurologic effects such as sleep disturbance, psychosis, and delirium are commonly cited adverse effects (AEs) of corticosteroids. Steroid use is considered a modifiable risk factor in intensive care unit patients; however, reported mechanisms are often lacking. This focused review will specifically evaluate the effects of steroids on sleep deprivation, psychosis, delirium, and what is known about these effects in a critically ill population.

OBSERVATIONS

The medical literature proposes 3 pathways primarily responsible for neurocognitive AEs of steroids: behavior changes through modification of the hypothalamic-pituitary-adrenal axis, changes in natural sleep-wake cycles, and hyperarousal caused by modification in neuroinhibitory pathways. Initial search fields produced 285 articles. Case reports, reviews, letters, and articles pertaining to primary care or palliative populations were excluded, leaving 8 relevant articles for inclusion.

CONCLUSIONS

Although steroid therapy often cannot be altered in the critically ill population, research showed that steroid overuse is common in intensive care units. Minimizing dosage and duration are important ways clinicians can mitigate AEs.

Social Safety Theory: A Biologically Based Evolutionary Perspective on Life Stress, Health, and Behavior

Social Safety Theory hypothesizes that developing and maintaining friendly social bonds is a fundamental organizing principle of human behavior and that threats to social safety are a critical feature of psychological stressors that increase risk for disease. Central to this formulation is the fact that the human brain and immune system are principally designed to keep the body biologically safe, which they do by continually monitoring and responding to social, physical, and microbial threats in the environment. Because situations involving social conflict, isolation, devaluation, rejection, and exclusion historically increased risk for physical injury and infection, anticipatory neural-immune reactivity to social threat was likely highly conserved. This neurocognitive and immunologic ability for humans to symbolically represent and respond to potentially dangerous social situations is ultimately critical for survival. When sustained, however, this multilevel biological threat response can increase individuals' risk for viral infections and several inflammation-related disease conditions that dominate present-day morbidity and mortality.

Assessment of Glial Activation Response in the Progress of Natural Scrapie after Chronic Dexamethasone Treatment

Neuroinflammation has been correlated with the progress of neurodegeneration in many neuropathologies. Although glial cells have traditionally been considered to be protective, the concept of them as neurotoxic cells has recently emerged. Thus, a major unsolved question is the exact role of astroglia and microglia in neurodegenerative disorders. On the other hand, it is well known that glucocorticoids are the first choice to regulate inflammation and, consequently, neuroglial inflammatory activity. The objective of this study was to determine how chronic dexamethasone treatment influences the host immune response and to characterize the beneficial or detrimental role of glial cells. To date, this has not been examined using a natural neurodegenerative model of scrapie. With this aim, immunohistochemical expression of glial markers, prion protein accumulation, histopathological lesions and clinical evolution were compared with those in a control group. The results demonstrated how the complex interaction between glial populations failed to compensate for brain damage in natural conditions, emphasizing the need for using natural models. Additionally, the data showed that modulation of neuroinflammation by anti-inflammatory drugs might become a research focus as a potential therapeutic target for prion diseases, similar to that considered previously for other neurodegenerative disorders classified as prion-like diseases.

Maternal high-fat diet induces sex-specific changes to glucocorticoid and inflammatory signaling in response to corticosterone and lipopolysaccharide challenge in adult rat offspring

BACKGROUND

Maternal obesity as a result of high levels of saturated fat (HFD) consumption leads to significant negative health outcomes in both mother and exposed offspring. Offspring exposed to maternal HFD show sex-specific alterations in metabolic, behavioral, and endocrine function, as well as increased levels of basal neuroinflammation that persists into adulthood. There is evidence that psychosocial stress or exogenous administration of corticosterone (CORT) potentiate inflammatory gene expression; however, the response to acute CORT or immune challenge in adult offspring exposed to maternal HFD during perinatal life is unknown. We hypothesize that adult rat offspring exposed to maternal HFD would show enhanced pro-inflammatory gene expression in response to acute administration of CORT and lipopolysaccharide (LPS) compared to control animals, as a result of elevated basal pro-inflammatory gene expression. To test this, we examined the effects of acute CORT and/or LPS exposure on pro and anti-inflammatory neural gene expression in adult offspring (male and female) with perinatal exposure to a HFD or a control house-chow diet (CHD).

METHODS

Rat dams consumed HFD or CHD for four weeks prior to mating, during gestation, and throughout lactation. All male and female offspring were weaned on to CHD. In adulthood, offspring were 'challenged' with administration of exogenous CORT and/or LPS, and quantitative PCR was used to measure transcript abundance of glucocorticoid receptors and downstream inflammatory markers in the amygdala, hippocampus, and prefrontal cortex.

RESULTS

In response to CORT alone, male HFD offspring showed increased levels of anti-inflammatory transcripts, whereas in response to LPS alone, female HFD offspring showed increased levels of pro-inflammatory transcripts. In addition, male HFD offspring showed greater pro-inflammatory gene expression and female HFD offspring exhibited increased anti-inflammatory gene expression in response to simultaneous CORT and LPS administration.

CONCLUSIONS

These findings suggest that exposure to maternal HFD leads to sex-specific changes that may alter inflammatory responses in the brain, possibly as an adaptive response to basal neuroinflammation.

Multi-Systemic Biological Risk and Cancer Mortality: The NHANES III Study

Multi-systemic biological risk (MSBR), a proxy for allostatic load, is a composite index of biomarkers representing dysregulation due to responses to chronic stress. This study examined the association of an MSBR index with cancer mortality. The sample included n = 13,628 adults aged 20–90 from the NHANES III Linked Mortality File (1988–1994). The MSBR index included autonomic (pulse rate, blood pressure), metabolic (HOMA_ir, triglycerides, waist circumference), and immune (white blood cell count, C-reactive protein) markers. We fit Cox proportional hazards models to estimate hazard ratios (HRs) and 95% confidence intervals (CI) of overall cancer mortality risk, according to quartiles (q) of the index. In multivariable models, compared to those in q1, q4 had a 64% increased risk for cancer mortality (HR = 1.64, 95% CI:1.13–2.40). The immune domain drove the association (HR per unit = 1.19, 95% CI:1.07–1.32). In stratified analyses, the HR for those with a BMI ≥ 25 was 1.12 per unit (95% CI:1.05–1.19) and those with a BMI < 25 was 1.04 per unit (95% CI:0.92–1.18). MSBR is positively associated with risk for cancer mortality in a US sample, particularly among those who are overweight or obese. The utilization of standard clinical measures comprising this index may inform population cancer prevention strategies.

Network between Cytokines, Cortisol and Occupational Stress in Gas and Oilfield Workers

To test whether gas and oil field work is accompanied by stress and altered immune function, the perception of workplace stress, levels of salivary cortisol, plasma levels, and mononuclear cell production of cytokines were examined in 80 healthy workers recruited among a population of operators on gas and oilfields. Specific questionnaires for determining the perception of anxiety, occupational stress, and subjective symptoms were administered. Salivary cortisol and cytokines plasma levels were evaluated by Elisa and to investigate immune function, both spontaneous and PHA- or LPS-induced expression and production of cytokines were assessed by qRT-PCR. Workers showed medium stress levels at work, with growth and increased motivation for work, and based on salivary cortisol concentrations, were divided into two groups of ≤10 ng/mL (n = 31) or >10 ng/mL (n = 49). Statistically significant higher plasma levels of IL-6, while lower TNFα, were detected in workers with cortisol >10 ng/mL. Also, BMI, DL, JD and Job strain were significantly higher in workers with cortisol >10 ng/mL. Thus, even modest variations of cortisol might have a role in the modulation of immune response and worker’s vulnerability to health imbalance.Thus, the evaluation of immune status, in addition to cortisol levels, could be useful to prevent illnesses; exacerbation of pre-existing conditions; morbidity; and consequent absences from work, with economic repercussions.