The hypothalamo-pituitary-adrenal axis in multiple sclerosis

Alterations in the Hypothalamic-Pituitary-Adrenal Axis as a Response to Experimental Autoimmune Encephalomyelitis in Dark Agouti Rats of Both Sexes

Multiple sclerosis (MS) is a chronic inflammatory disease that affects the central nervous system, usually diagnosed during the reproductive period. Both MS and its commonly used animal model, experimental autoimmune encephalomyelitis (EAE), exhibit sex-specific features regarding disease progression and disturbances in the neuroendocrine and endocrine systems. This study investigates the hypothalamic-pituitary-adrenal (HPA) axis response of male and female Dark Agouti rats during EAE. At the onset of EAE, Crh expression in the hypothalamus of both sexes is decreased, while males show reduced plasma adrenocorticotropic hormone levels. Adrenal gland activity is increased during EAE in both males and females, as evidenced by enlarged adrenal glands and increased StAR gene and protein expression. However, only male rats show increased serum and adrenal corticosterone levels, and an increased volume of the adrenal cortex. Adrenal 3β-HSD protein and progesterone levels are elevated in males only. Serum progesterone levels of male rats are also increased, although testicular progesterone levels are decreased during the disease, implying that the adrenal gland is the source of elevated serum progesterone levels in males. Our results demonstrate a sex difference in the response of the HPA axis at the adrenal level, with male rats showing a more pronounced induction during EAE.

Lipid metabolism is dysregulated in endocrine glands upon autoimmune demyelination

Disturbance in neuroendocrine signaling has been consistently documented in multiple sclerosis (MS), a chronic autoimmune disorder of the central nervous system (CNS) representing the main cause of non-traumatic brain injury among young adults. In fact, MS patients display altered hormonal levels and psychiatric symptoms along with the pathologic hallmarks of the disease, which include demyelination, neuroinflammation and axonal injury. In addition, we have recently shown that extensive transcriptional changes take place in the hypothalamus of mice upon the MS model experimental autoimmune encephalomyelitis (EAE). We also detected structural and functional aberrancies in endocrine glands of EAE animals. Specifically, we described the hyperplasia of adrenal glands and the atrophy of ovaries at disease peak. To further expand the characterization of these phenotypes, here we profiled the transcriptomes of both glands by means of RNA-seq technology. Notably, we identified fatty acid and cholesterol biosynthetic pathways as the most dysregulated molecular processes in adrenals and ovaries, respectively. Furthermore, we demonstrated that key genes encoding neuropeptides and hormone receptors undergo distinct expression dynamics in the hypothalamus along disease progression. Altogether, our results corroborate the dysfunction of the neuroendocrine system as a major pathological event of autoimmune demyelination and highlight the crosstalk between the CNS and the periphery in mediating such disease phenotypes.

Experimental Autoimmune Encephalomyelitis Influences GH-Axis in Female Rats

Inflammation, demyelination, and axonal damage to the central nervous system (CNS) are the hallmarks of multiple sclerosis (MS) and its representative animal model, experimental autoimmune encephalomyelitis (EAE). There is scientific evidence for the involvement of growth hormone (GH) in autoimmune regulation. Previous data on the relationship between the GH/insulin like growth factor-1 (IGF-1) axis and MS/EAE are inconclusive; therefore, the aim of our study was to investigate the changes in the GH axis during acute monophasic EAE. The results show that the gene expression of Ghrh and Sst in the hypothalamus does not change, except for Npy and Agrp, while at the pituitary level the Gh, Ghrhr and Ghr genes are upregulated. Interestingly, the cell volume of somatotropic cells in the pituitary gland remains unchanged at the peak of the disease. We found elevated serum GH levels in association with low IGF-1 concentration and downregulated Ghr and Igf1r expression in the liver, indicating a condition resembling GH resistance. This is likely due to inadequate nutrient intake at the peak of the disease when inflammation in the CNS is greatest. Considering that GH secretion is finely regulated by numerous central and peripheral signals, the involvement of the GH/IGF-1 axis in MS/EAE should be thoroughly investigated for possible future therapeutic strategies, especially with a view to improving EAE disease.

Emerging Theories of Allostatic-Interoceptive Overload in Neurodegeneration

Recent integrative multilevel models offer novel insights into the etiology and course of neurodegenerative conditions. The predictive coding of allostatic-interoception theory posits that the brain adapts to environmental demands by modulating internal bodily signals through the allostatic-interoceptive system. Specifically, a domain-general allostatic-interoceptive network exerts adaptive physiological control by fine-tuning initial top-down predictions and bottom-up peripheral signaling. In this context, adequate adaptation implies the minimization of prediction errors thereby optimizing energy expenditure. Abnormalities in top-down interoceptive predictions or peripheral signaling can trigger allostatic overload states, ultimately leading to dysregulated interoceptive and bodily systems (endocrine, immunological, circulatory, etc.). In this context, environmental stress, social determinants of health, and harmful exposomes (i.e., the cumulative life-course exposition to different environmental stressors) may interact with physiological and genetic factors, dysregulating allostatic interoception and precipitating neurodegenerative processes. We review the allostatic-interoceptive overload framework across different neurodegenerative diseases, particularly in the behavioral variant frontotemporal dementia (bvFTD). We describe how concepts of allostasis and interoception could be integrated with principles of predictive coding to explain how the brain optimizes adaptive responses, while maintaining physiological stability through feedback loops with multiple organismic systems. Then, we introduce the model of allostatic-interoceptive overload of bvFTD and discuss its implications for the understanding of pathophysiological and neurocognitive abnormalities in multiple neurodegenerative conditions.

Neonatal di-(2-ethylhexyl)phthalate exposure induces permanent alterations in secretory CRH neuron characteristics in the hypothalamus paraventricular region of adult male rats

Corticotrophin-releasing hormone (CRH) neurons in the hypothalamic paraventricular nucleus (PVN) play a critical role in the modulation of the hypothalamic-pituitary-adrenal (HPA) axis. Early-life exposure to di-(2-ethylhexyl) phthalate (DEHP) has been associated with an increased risk of developing psychiatric disorders in adulthood. The present work was designed to explore the impact of neonatal exposure to DEHP on adult PVN CRH neuronal activity. DEHP or vehicle was given to male rat pups from PND16 to PND22. Then, anxiety-like behaviors, serum corticosterone and testosterone, immunohistochemistry, western blotting, fluorescence in situ hybridization and acute ex vivo slice electrophysiological recordings were used to evaluate the influence of DEHP on adult PVN secretory CRH neurons. Neonatal DEHP-exposed rats exhibited enhanced anxiety-like behaviors in adults, with an increase in CORT. Secretory CRH neurons showed higher spontaneous firing activity but could be inhibited by GABAAR blockers. CRH neurons displayed fewer firing spikes, prolonged first-spike latency, depolarizing shifts in GABA reversal potential and strengthened GABAergic inputs, as indicated by increases in the frequency and amplitude of sIPSCs. Enhancement of GABAergic transmission was accompanied by upregulated expression of GAD67 and downregulated expression of GABABR1, KCC2 and GAT1. These findings suggest that neonatal exposure to DEHP permanently altered the characteristics of secretory CRH neurons in the PVN, which may contribute to the development of psychiatric disorders later in life.

Relationships between cause of death and concentrations of seven steroids obtained from the serum and cerebrospinal fluid of cadavers

In this study, we assessed 80 autopsy samples to investigate the relationships between cause of death and the concentrations of multiple steroids in serum and cerebrospinal fluid (CSF). First, we developed and validated analytical methods to quantify seven steroids (cortisol, cortisone, corticosterone, 11-deoxycortisol, 11-deoxycortiocosterone, progesterone, and testosterone) by using liquid chromatography coupled with electrospray ionization-tandem mass spectrometry. Next, we statistically evaluated the levels of each steroid for six causes of death: hypothermia, traumatic injury, fire fatality, asphyxia, intoxication, and internal disease. We observed that cortisol concentrations in serum and CSF obtained from cadavers who died from hypothermia were significantly higher than those in samples obtained from cadavers who died from the remaining causes of death (P < 0.05). Similarly, corticosterone concentrations obtained from cadavers who died from hypothermia were significantly higher than those in samples from several other causes of death. However, concentrations of the remaining steroids analyzed did not differ significantly among the causes of death. We further elucidated the correlations between steroid concentrations in serum and CSF. Except for 11-deoxycorticosterone and progesterone, steroid concentrations were significantly positively correlated in serum and CSF. Although data on cadaveric steroid concentrations are limited-especially in CSF-values obtained were in the approximate range of the living human data reported to date.

A new perspective of hypothalamic disease: Shapiro's syndrome

Shapiro's syndrome (SS) is characterized by spontaneous periodic hypothermia. It occurs to patients regardless of age or sex. To date, &lt;60 cases have been reported worldwide. Current knowledge of the disease is limited to clinical feature since the pathogenesis and etiology are still controversial. In this review, the clinical characteristics, pathological mechanism, and possible etiology of the syndrome were reviewed to improve the clinical understanding of the disease.

The Function of the Hypothalamic-Pituitary-Adrenal Axis During Experimental Autoimmune Encephalomyelitis: Involvement of Oxidative Stress Mediators

Multiple sclerosis (MS) is an inflammatory, demyelinating disease with an unknown origin. Previous studies showed the involvement of the hypothalamic–pituitary–adrenal (HPA) axis to susceptibility to autoimmune diseases, including MS, and its best-characterized animal model, experimental autoimmune encephalomyelitis (EAE). During MS/EAE, innate immune cells are activated and release cytokines and other inflammatory mediators, leading to a vicious cycle of inflammation. In response to inflammation, the activated HPA axis modulates immune responses via glucocorticoid activity. Because the mechanisms involving oxidative stress to the HPA axis are relatively unrevealed, in this study, we investigate the inflammatory and oxidative stress status of HPA axis during EAE. Our results reveal an upregulation of Pomc gene expression, followed by POMC and ACTH protein increase at the peak of the EAE in the pituitary. Also, prostaglandins are well-known contributors of HPA axis activation, which increases during EAE at the periphery. The upregulated Tnf expression in the pituitary during the peak of EAE occurred. This leads to the activation of oxidative pathways, followed by upregulation of inducible NO synthase expression. The reactive oxidant/nitrosative species (ROS/RNS), such as superoxide anion and NO, increase their levels at the onset and peak of the disease in the pituitary and adrenal glands, returning to control levels at the end of EAE. The corticotrophs in the pituitary increased in number and volume at the peak of EAE that coincides with high lipid peroxidation levels. The expression of MC2R in the adrenal glands increases at the peak of EAE, where strong induction of superoxide anion and malondialdehyde (MDA), reduced total glutathione (GSH) content, and catalase activity occurred at the peak and end of EAE compared with controls. The results obtained from this study may help in understanding the mechanisms and possible pharmacological modulation in MS and demonstrate an effect of oxidative stress exposure in the HPA activation during the course of EAE.

Cardiovascular, Cellular, and Neural Adaptations to Hot Yoga versus Normal-Temperature Yoga

CONTEXT

Chronic heat exposure promotes cardiovascular and cellular adaptations, improving an organism's ability to tolerate subsequent stressors. Heat exposure may also promote neural adaptations and alter the neural-hormonal stress response. Hot-temperature yoga (HY) combines mind-body exercise with heat exposure. The added heat component in HY may induce cardiovascular and cellular changes, along with neural benefits and modulation of stress hormones.

AIMS

The purpose of the present study is to compare the cardiovascular, cellular heat shock protein 70 (HSP70), neural, and hormonal adaptations of HY versus normal-temperature yoga (NY).

SETTINGS AND DESIGN

Twenty-two subjects (males = 11 and females = 11, 26 ± 6 years) completed 4 weeks of NY (n = 11) or HY (n = 11, 41°C, 40% humidity). Yoga sessions were performed 3 times/week following a modified Bikram protocol.

SUBJECTS AND METHODS

Pre- and posttesting included (1) hemodynamic measures during a heat tolerance test and maximal aerobic fitness test; (2) neural and hormonal adaptations using serum brain-derived neurotrophic factor (BDNF) and adrenocorticotropic hormone (ACTH), along with a mental stress questionnaire; and (3) cellular adaptations (HSP70) in peripheral blood mononuclear cells (PBMCs).

STATISTICAL ANALYSIS

Within- and between-group Student's t-test analyses were conducted to compare pre- and post-VO2 max, perceived stress, BDNF, HSP70, and ACTH in HY and NY groups.

RESULTS

Maximal aerobic fitness increased in the HY group only. No evidence of heat acclimation or change in mental stress was observed. Serum BDNF significantly increased in yoga groups combined. Analysis of HSP70 suggested higher expression of HSP70 in the HY group only.

CONCLUSIONS

Twelve sessions of HY promoted cardiovascular fitness and cellular thermotolerance adaptations. Serum BDNF increased in response to yoga (NY + HY) and appeared to not be temperature dependent.

Stressful life events are associated with the risk of multiple sclerosis

BACKGROUND AND PURPOSE

Unexpected stressful life events may alter immune function and affect susceptibility to autoimmune diseases including multiple sclerosis (MS). Current results from epidemiological investigations examining the role of stress in MS remain inconsistent. The aim was to conduct the hitherto largest population-based case-control study on this topic.

METHODS

Extensive questionnaire information collected on lifestyle environmental factors available for 2930 incident MS cases and 6170 controls were used to assess the association of 10 major life events that had occurred before disease onset with the risk of MS by unconditional logistic regressions, adjusting for potential confounders. Stratified analyses were also performed by sex and time.

RESULTS

Compelling evidence was found for a link between major life events and risk of MS - most events significantly increased disease risk by 17%-30%. It was further observed that women were affected to a greater extent than men under certain stressful scenarios, and that most events that happened recently (≤5 years prior to MS onset) had significant effects on MS, indicating a critical window in disease development.

CONCLUSION

Stressful life events may have an adverse effect on the risk of MS. Research into the mechanisms of this observation may give important clues to triggering pathogenetic events in MS.

Determination of neurosteroids in human cerebrospinal fluid in the 21st century: A review

Determination of steroid hormones synthesized by the human body plays an important role in various fields of endocrinology. Neurosteroids (NS) are steroids that are synthesized in the central (CNS) or peripheral nervous system (PNS), which is not only a source but also a target for neurosteroids. They are discussed as possible biomarkers in various cognitive disorders and research interest in this topic raises continuously. Nevertheless, knowledge on functions and metabolism is still limited, although the concept of neurosteroids was already introduced in the 1980s. Until today, the analysis of neurosteroids is truly challenging. The only accessible matrix for investigations of brain metabolism in living human beings is cerebrospinal fluid (CSF), which therefore becomes a very interesting specimen for analysis. However, neurosteroid concentrations are expected to be very low and the available amount of cerebrospinal fluid is limited. Further, high structural similarities of endogenous neurosteroids challenges analysis. Therefore, comprehensive methods, highly selective and sensitive for a large range of concentrations for different steroids in one aliquot are required and under continuous development. Although research has been increasingly intensified, still only few data are available on reference levels of neurosteroids in human cerebrospinal fluid. In this review, published literature of the last twenty years, as a period with relatively contemporary analytical methods, was systematically investigated. Considerations on human cerebrospinal fluid, different analytical approaches, and available data on levels of in analogy to periphery conceivable occurring neurosteroids, including (pro-) gestagens, androgens, corticoids, estrogens, and steroid conjugates, and their interpretation are intensively discussed.

Towards a comprehensive etiopathogenetic and pathophysiological theory of multiple sclerosis

Background: Multiple sclerosis (MS) is a neurodegenerative disease caused by dysfunction of the immune system that affects the central nervous system (CNS). It is characterized by demyelination, chronic inflammation, neuronal and oligodendrocyte loss and reactive astrogliosis. It can result in physical disability and acute neurological and cognitive problems. Despite the gains in knowledge of immunology, cell biology, and genetics in the last five decades, the ultimate etiology or specific elements that trigger MS remain unknown. The objective of this review is to propose a theoretical basis for MS etiopathogenesis.Methods: Search was done by accessing PubMed/Medline, EBSCO, and PsycINFO databases. The search string used was "(multiple sclerosis* OR EAE) AND (pathophysiology* OR etiopathogenesis)". The electronic databases were searched for titles or abstracts containing these terms in all published articles between January 1, 1960, and June 30, 2019. The search was filtered down to 362 articles which were included in this review.Results: A framework to better understand the etiopathogenesis and pathophysiology of MS can be derived from four essential factors; mitochondria dysfunction (MtD) & oxidative stress (OS), vitamin D (VD), sex hormones and thyroid hormones. These factors play a direct role in MS etiopathogenesis and have a modulatory effect on many other factors involved in the disease.Conclusions: For better MS prevention and treatment outcomes, efforts should be geared towards treating thyroid problems, sex hormone alterations, VD deficiency, sleep problems and melatonin alterations. MS patients should be encouraged to engage in activities that boost total antioxidant capacity (TAC) including diet and regular exercise and discouraged from activities that promote OS including smoking and alcohol consumption.

Stress-Axis Regulation by Vitamin D3 in Multiple Sclerosis

Introduction

Multiple sclerosis (MS) has been associated with both a poor vitamin D status and hyperactivity of the hypothalamus–pituitary–adrenal (HPA) axis. Since nuclear receptor ligands may regulate each other, we explored the association of vitamin D₃ supplements with circadian cortisol levels in a double-blind and placebo-controlled supplementation study.

Methods

Female patients with relapsing-remitting MS received vitamin D₃ supplements (4,000 IU/day; n = 22) or placebo (n = 19) during 16 weeks. Salivary cortisol levels, repeatedly measured during the day, and serum 25(OH)D levels were assessed before (T0) and after (T1) this treatment period.

Results

Median 25(OH)D levels at T1 were 139.9 (interquartile range 123.5–161.2) and 74.5 nmol/L (58.6–88.1) in the vitamin D₃ and placebo group, respectively (p < 0.001). Comparisons within and between groups showed no differences in area under the curve (AUC) and slope of the cortisol day curve. Although the AUC of the cortisol awakening response (CAR, sampling each 15 min the first hour after awakening) showed a reduction over time in the vitamin D₃ group [39.16 nmol/L (27.41–42.07) at T0 to 33.37 nmol/L (26.75–38.08) at T1] compared to the placebo group [33.90 nmol/L (25.92–44.61) at T0 to 35.00 nmol/L (25.46–49.23) at T1; p = 0.044], there was no significant difference in AUC of CAR at T1 corrected for baseline AUC of CAR (p = 0.066).

Conclusion

Suppression of HPA-axis activity by vitamin D₃ supplements in non-depressed MS patients may be best reflected by CAR as primary outcome measure. Further studies should address this interaction and its potential implications for the disease course of MS.

Registration

This study was registered on ClinicalTrials.gov (NCT02096133) and EudraCT (2014-000728-97).

Stressful life events and the risk of initial central nervous system demyelination

BACKGROUND

There is substantial evidence that stress increases multiple sclerosis disease activity, but limited evidence on its association with the onset of multiple sclerosis.

OBJECTIVE

To examine the association between stressful life events and risk of first demyelinating event (FDE).

METHODS

This was a multicentre incident case-control study. Cases ( n = 282 with first diagnosis of central nervous system (CNS) demyelination, including n = 216 with 'classic FDE') were aged 18-59 years. Controls without CNS demyelination ( n = 558) were matched to cases on age, sex and study region. Stressful life events were assessed using a questionnaire based on the Social Readjustment Rating Scale.

RESULTS

Those who suffered from a serious illness in the previous 12 months were more likely to have an FDE (odds ratio (OR) = 2.35 (1.36, 4.06), p = 0.002), and when we limited our reference group to those who had no stressful life events, the magnitude of effect became stronger (OR = 5.41 (1.80, 16.28)). The total stress number and stress load were not convincingly associated with the risk of an FDE.

CONCLUSION

Cases were more likely to report a serious illness in the previous 12 months, which could suggest that a non-specific illness provides an additional strain to an already predisposed immune system.

Altered cytokine responses to cognitive stress in multiple sclerosis patients with fatigue

This study intended to examine if the immune response to a cognitive task as a variant of psychological stress in MS patients is distinct from healthy controls. The experiment was part of a larger study on mechanisms and measurements of MS fatigue. Patients (n=23) and controls (n=25) participated in a cognitive task lasting 40 minutes, in which the heart rate was continuously monitored. Blood samples were taken at baseline and directly after the stress-inducing task. Whole blood stimulated cytokine production representative of the TH-1 (i.e. IFNγ, TNFα) and TH-2 paradigm (i.e. IL-10) was evaluated in relation to disability, fatigue, cognitive deficit, and anxiety. Patients scored high on a disease specific fatigue score compared to controls, whereas baseline cytokine patterns did not differ between the groups. MS patients displayed a blunted response of IFNg (P=0.03) whereas TNFα and IL-10 responses did not change. Additionally MS patients showed a significantly lower heart rate increase after the task (P<0.001). Cognitive impairment was associated with a decreased heart rate reactivity (P=0.02) while depressive symptoms correlated with stronger IL-10 responses (P=0.05). Overall, cognitive stress induces IFNγ production in healthy controls but not in MS patients with fatigue. Furthermore, a reduced cardiac response might indicate an autonomic dysfunction in this group of patients.

Icariin exerts estrogen-like activity in ameliorating EAE via mediating estrogen receptor β, modulating HPA function and glucocorticoid receptor expression

BACKGROUND

Estrogen exerts neuroprotective and anti-inflammatory effects in EAE and multiple sclerosis (MS), but its clinical application is hindered due to side effects and risk of tumor. Phytoestrogen structurally or functionally mimics estrogen with fewer side effects than endogenous estrogen. Icariin (ICA), an active component of Epimedium extracts, demonstrates estrogen-like neuroprotective effects. However, it is unclear whether ICA is effective in EAE and what are the underlying mechanisms.

OBJECTIVE

To determine the therapeutic effects of ICA in EAE and explore the possible mechanisms.

METHODS

C57BL/6 EAE mice were treated with Diethylstilbestrol, different dose of ICA and mid-dose ICA combined with ICI 182780. The clinical scores and serum Interleukin-17 (IL-17), Corticosterone (CORT) concentrations were then analyzed. Western blot were performed to investigate the expressions of glucocorticoid receptor (GR), estrogen receptor alpha (ERα) and ERβ in the cerebral white matter of EAE mice.

RESULTS

High dose ICA is equally effective in ameliorating neurological signs of EAE as estrogen. Estrogen and ICA has no effects on serum concentrations of IL-17 in EAE. While the CORT levels were decreased by ICA at mid or high doses, the expressions of GR, ERα and ERβ were up-regulated by estrogen or different doses of ICA in a dosedependent manner. Estrogen induced the elevation of ERα more markedly than ICA. In contrast, ICA at mid and high doses promoted ERβ more significantly than estrogen.

CONCLUSION

ICA exerts estrogen-like activity in ameliorating EAE via mediating ERβ, modulating HPA function and up-regulating the expression of GR in cerebral white matter. ICA may be a promising therapeutic option for MS.

Analytical challenges for measuring steroid responses to stress, neurodegeneration and injury in the central nervous system

Levels of steroids in the adult central nervous system (CNS) show marked changes in response to stress, degenerative disorders and injury. However, their analysis in complex matrices such as fatty brain and spinal cord tissues, and even in plasma, requires accurate and precise analytical methods. Radioimmunoassays (RIA) and enzyme-linked immunosorbent assays, even with prepurification steps, do not provide sufficient specificity, and they are at the origin of many inconsistent results in the literature. The analysis of steroids by mass spectrometric methods has become the gold standard for accurate and sensitive steroid analysis. However, these technologies involve multiple purification steps prone to errors, and they only provide accurate reference values when combined with careful sample workup. In addition, the interpretation of changes in CNS steroid levels is not an easy task because of their multiple sources: the endocrine glands and the local synthesis by neural cells. In the CNS, decreased steroid levels may reflect alterations of their biosynthesis, as observed in the case of chronic stress, post-traumatic stress disorders or depressive episodes. In such cases, return to normalization by administering exogenous hormones or by stimulating their endogenous production may have beneficial effects. On the other hand, increases in CNS steroids in response to acute stress, degenerative processes or injury may be part of endogenous protective or rescue programs, contributing to the resistance of neural cells to stress and insults. The aim of this review is to encourage a more critical reading of the literature reporting steroid measures, and to draw attention to the absolute need for well-validated methods. We discuss reported findings concerning changing steroid levels in the nervous system by insisting on methodological issues. An important message is that even recent mass spectrometric methods have their limits, and they only become reliable tools if combined with careful sample preparation.

Utility of cerebrospinal fluid cortisol level in acute bacterial meningitis

Background:

Meningitis remains a serious clinical problem in developing as well as developed countries. Delay in diagnosis and treatment results in significant morbidity and mortality. The role and levels of intrathecal endogenous cortisol is not known.

Objective:

To study the cerebrospinal fluid (CSF) cortisol levels and to evaluate its role as a diagnostic and therapeutic marker in acute bacterial meningitis.

Materials and Methods:

Thirty patients with acute bacterial meningitis with no prior treatment were evaluated. Cortisol levels were compared with 20 patients with aseptic (viral) meningitis and 25 control subjects.

Results:

Mean CSF cortisol level was 13.85, 3.47, and 1.05 in bacterial meningitis, aseptic meningitis, and controls, respectively. Mean CSF cortisol level in bacterial meningitis was significantly higher as compared to controls (P < 0.001). There was significant difference in CSFcortisol levels in bacterial and aseptic meningitis (P < 0.001).

Conclusions:

Cortisol levels in CSF are highly elevated in patients with acute bacterial meningitis. This suggests that intrathecalcortisol may serve as a valuable, rapid, relatively inexpensive diagnostic marker in discriminatingbetween bacterial and aseptic meningitis. This helps in earlier institution of appropriate treatment and thereby decreasing morbidity and mortality.

Icariin has synergistic effects with methylprednisolone to ameliorate EAE via modulating HPA function, promoting anti-inflammatory and anti-apoptotic effects

BACKGROUND

High-dose methylprednisolone (MP) is a clinically recommended therapeutic regimen for Multiple Sclerosis (MS), whereas some dreadful complications induced by it remain inevitable. Studies implied that estrogens might play neuroprotective and anti-inflammatory roles in EAE and MS and promote glucocorticoid efficacy. Icariin (ICA), a primary active component of Epimedium extracts, also possesses neuroprotective and estrogen-like effects with less adverse complication than estrogen. However, rare study focuses ICA's effects on MS or EAE.

OBJECTIVE

Our purpose is to determine whether ICA has synergistic effects with MP in treating EAE and explore the possible mechanisms.

METHODS

C57BL/6 EAE mice were received different dose of ICA combined with MP and single MP treatment. Then, the clinical scores and serum Interleukin-17 (IL-17), Corticosterone (CORT), Adrenocorticotropic Hormone (ACTH) concentrations were analyzed. Western blot and Flow Cytometry were used to investigate the expression of glucocorticoid receptor (GR) and cell apoptosis.

RESULTS

ICA has cooperative effects with MP in decreasing serum IL-17 and CORT concentrations, up-regulating the expression of GR in cerebral white matter and attenuating the cell apoptosis in spinal cord, especially high-dose ICA combined with MP.

CONCLUSION

ICA has synergistic effects with MP to ameliorate EAE via modulating hypothalamic-pituitary-adrenal (HPA) function, promoting anti-inflammatory and anti-apoptotic effects. ICA could be considered as a promising therapeutic option for MS.

Multiple sclerosis, relapses, and the mechanism of action of adrenocorticotropic hormone

Relapses in multiple sclerosis (MS) are disruptive and frequently disabling for patients, and their treatment is often a challenge to clinicians. Despite progress in the understanding of the pathophysiology of MS and development of new treatments for long-term management of MS, options for treating relapses have not changed substantially over the past few decades. Corticosteroids, a component of the hypothalamic-pituitary-adrenal axis that modulate immune responses and reduce inflammation, are currently the mainstay of relapse treatment. Adrenocorticotropic hormone (ACTH) gel is another treatment option. Although it has long been assumed that the efficacy of ACTH in treating relapses depends on the peptide’s ability to increase endogenous corticosteroid production, evidence from research on the melanocortin system suggests that steroidogenesis may only partly account for ACTH influences. Indeed, the melanocortin peptides [ACTH and α-, β-, γ-melanocyte-stimulating hormones (MSH)] and their receptors (Melanocortin receptors, MCRs) exert multiple actions, including modulation of inflammatory and immune mediator production. MCRs are widely distributed within the central nervous system and in peripheral tissues including immune cells (e.g., macrophages). This suggests that the mechanism of action of ACTH includes not only steroid-mediated indirect effects, but also direct anti-inflammatory and immune-modulating actions via the melanocortin system. An increased understanding of the role of the melanocortin system, particularly ACTH, in the immune and inflammatory processes underlying relapses may help to improve relapse management.

Multiple sclerosis and sexual dysfunction

Multiple sclerosis (MS) is a chronic inflammatory demyelinating disorder of the central nervous system characterized by episodic and progressive neurologic dysfunction resulting from inflammatory and autoimmune reactions. The underlying pathogenesis of MS remains largely unclear. However, it is currently accepted as a T cell-mediated autoimmune disease. Among other clinical manifestations, sexual dysfunction (SD) is a painful but still underreported and underdiagnosed symptom of the disorder. SD in MS patients may result from a complex set of conditions and may be associated with multiple anatomic, physiologic, biologic, medical and psychological factors. SD arises primarily from lesions affecting the neural pathways involved in physiologic function. In addition, psychological factors, the side effects of medications and physical symptoms such as fatigue, muscular weakness, menstrual changes, pain and concerns about bladder and bowel incontinence may also be involved. Since MS primarily affects young people, SD secondary to MS may have a great impact on quality of life. Thus, maintaining a healthy sexual life with MS is an important priority. The treatment of SD requires multidisciplinary teamwork and cooperation among specialists, individual patients, partners and the society.

Relationship between global cognitive decline and depressive symptoms in multiple sclerosis

Cognitive impairment and depressed mood are common symptoms in multiple sclerosis (MS), which significantly impact patients' role functioning and quality of life. Cross-sectional studies indicate a modest association between cognitive impairment and depressive symptoms in MS. Longitudinal studies show inconsistent results but provide some data indicating a relationship between increasing global cognitive decline and increasing depressive symptoms over time. Establishing whether such a relationship exists represents an important first step in understanding the temporal nature of that relationship along with any treatment implications. The current study investigated this relationship by using the adjusted difference between a demographic estimate of premorbid intellectual functioning (Barona) and a performance measure of current intellectual functioning (Shipley Institute of Living) to capture long-term global cognitive decline in MS patients. Degree of global cognitive decline was then related to a self-report measure of mood, evaluative, and vegetative depression symptoms (Chicago Multiscale Depression Inventory). Global cognitive decline accounted for 5% of the variance in mood-evaluative symptoms but none of the variance in vegetative symptoms. When groups experiencing moderate, mild, and no global cognitive decline were compared on depression symptom subscales, MS patients experiencing moderate cognitive decline reported significantly higher mood and evaluative, but not vegetative, depressive symptoms than MS patients with stable cognitive functioning.

Hormonal influences in multiple sclerosis

The function of hormones has expanded to include immunomodulation and neuroprotection in addition to their classic roles. The story of how hormones influence inflammation and neuron and glial function is being slowly unraveled. There is increasing evidence that estrogen, progesterone, and testosterone contain immune responses and influence damage repair in the nervous system. Hormones such as prolactin and vitamin D are being explored as immunomodulators and may influence diseases such as multiple sclerosis (MS) or may be used therapeutically to modulate the immune response. More recently identified hormones, such as leptin and gherlin, may also influence the course of disease. This chapter reviews some of the evidence that supports a role for hormones in MS.

Cortisol levels in cerebrospinal fluid correlate with severity and bacterial origin of meningitis

Introduction

Outcomes following bacterial meningitis are significantly improved by adjunctive treatment with corticosteroids. However, little is known about the levels and significance of intrathecal endogenous cortisol. The aim of this study was to assess cortisol as a biological and diagnostic marker in patients with bacterial meningitis.

Methods

Forty-seven consecutive patients with bacterial meningitis and no prior treatment were evaluated. For comparison, a group of 37 patients with aseptic meningitis and a group of 13 healthy control individuals were included.

Results

The mean age of the bacterial meningitis patients was 42 years, and the mean Glasgow Coma Scale, Acute Physiology and Chronic Health Evaluation II, and Sequential Organ Failure Assessment scores on admission were 12, 13 and 4, respectively. Altogether, 40 patients (85%) were admitted to the intensive care unit, with a median (interquartile range) length of stay of 8 (4 to 15) days. A bacterial etiology was confirmed in 35 patients (74%). The median (interquartile range) cortisol concentration in cerebrospinal fluid (CSF) was 133 (59 to 278) nmol/l. CSF cortisol concentrations were positively correlated with serum cortisol levels (r = 0.587, P < 0.001). Furthermore, CSF cortisol levels correlated with Acute Physiology and Chronic Health Evaluation II score (r = 0.763, P < 0.001), Sequential Organ Failure Assessment score (r = 0.650, P < 0.001), Glasgow Coma Scale score (r = -0.547, P < 0.001) and CSF lactate levels (r = 0.734, P < 0.001). CSF cortisol was only weakly associated with intrathecal levels of IL-6 (r = 0.331, P = 0.02) and IL-8 (r = 0.296, P < 0.05). CSF cortisol levels in bacterial and aseptic meningitis significantly differed (P < 0.001). The CSF cortisol concentration of 46.1 nmol/l was found to be the optimal cutoff value for diagnosis of bacterial meningitis.

Conclusion

CSF cortisol levels in patients with bacterial meningitis are highly elevated and correlate with disease severity. Moreover, our findings also suggest that intrathecal cortisol may serve as a valuable marker in discriminating between bacterial and aseptic meningitis.

Measurement and meaning of salivary cortisol: a focus on health and disease in children

Measurement of salivary cortisol can provide important information about hypothalamic-pituitary-adrenal (HPA) axis activity under normal conditions and in response to stress. However, there are many variables relating to the measurement of cortisol in saliva which may introduce error and therefore may render difficult the comparison and interpretation of data between, and within, laboratories. This review addresses the effects of gender, age, time and location of sampling, units of measurement, assay conditions and compliance with the protocol, all of which have the potential to impact upon the precision, accuracy and reliability of salivary cortisol measurements in the literature. Some of these factors are applicable to both adults and children, but the measurement of salivary cortisol in children introduces aspects of unique variability which demand special attention. The specific focus of this review is upon the somewhat neglected area of methodological variability of salivary cortisol measurement in children. In addition to these methodological issues, the review highlights the use of salivary cortisol measurements to provide information about HPA axis dysfunction associated with psycho- and patho-physiological conditions in children. Novel applications for salivary cortisol measurements in future research into HPA axis activity in children are also discussed.

Corticosteroids, 11beta-hydroxysteroid dehydrogenase isozymes and the rabbit choroid plexus

The epithelial cells of the choroid plexus (CP) are responsible for cerebrospinal fluid (CSF) secretion into the ventricles of the brain. The balance between CSF production and drainage, in part, facilitates a normal intracranial pressure. The secretion of Na(+) and anions by the CP creates an osmotic gradient driving water into the ventricles. This is opposite to classical Na(+) transporting tissues, such as the kidney, where Na(+) and water reabsorption is mediated by 11beta-hydroxysteroid dehydrogenase type 2 that protects the mineralocorticoid receptor by abrogating active cortisol to inactive cortisone. In the human ocular ciliary epithelium, Na(+) and water secretion is dependent on a novel mediator of ciliary epithelial Na(+) transport, 11beta-HSD type 1 (11beta-HSD1), that generates intraocular cortisol. In a mechanism analogous to that of the embryologically related ocular ciliary epithelium, we propose that autocrine regulation of intracranial cortisol is dependent on 11beta-HSD1 expression in the CP epithelial cells. By conducting immunolocalisation studies on brains from New Zealand White Albino rabbits, we defined the expression of 11beta-HSD1 in the secretory CP epithelial cells. Enzyme assays performed on intact rabbit CP whole tissue explants confirmed predominant 11beta-HSD1 activity, generating cortisol that was inhibited by glycyrrhetinic acid (an 11beta-HSD inhibitor). Using the real time-polymerase chain reaction, rabbit CP tissue was found to express levels of 11beta-HSD1, glucocorticoid receptor alpha and serum and glucocorticoid-regulated kinase 1 mRNA comparable to that expressed in rabbit ocular ciliary body, thereby highlighting the similarity between these two tissues. Furthermore, an enzyme-linked immunosorbent assay of rabbit CSF revealed a median cortisol concentration of 1.7 nmol/l (range 1.4-4.3 nmol/l, n = 9). Our data have identified a functional 11beta-HSD1 within the CP, mediating intracranial cortisol bioavailability. Expression of 11beta-HSD1 may be fundamental in the regulation of CSF secretion and the local generation of cortisol may represent a pathophysiological mechanism underlying cortisol-dependent neuroendocrine diseases.

Stress regulation in multiple sclerosis: current issues and concepts

Since its first description by Charcot, psychological stress has been considered a triggering factor for exacerbations in multiple sclerosis, but until recently the clinical evidence for a causal relation was weak. Over the past years, a growing number of studies have started to elucidate this association and highlight potential mechanisms, including brain-immune communication. On 5 June 2005, a panel of international researchers discussed the current evidence. This article summarizes the observational, animal experimental, as well as human experimental findings on stress regulation in MS, as well as studies on the functioning of the major stress response systems, ie, the hypothalamo-pituitary-adrenal (HPA) axis and the autonomous nervous system (ANS) in MS. Consensus statements from the group to these aspects are given. Research objectives and strategies are delineated, as well as clinical implications.

[Psychological stress, immune function and disease development. The psychoneuroimmunologic perspective]

Interdisciplinary psychoneuroimmunological (PNI) research increasingly demonstrates clinically relevant interrelations between psychological stressors and the onset or progression of chronic diseases. Disturbances of the bi-directional interaction between the nervous system, the immune system and the endocrine system have been hypothesized to be implicated in several diseases. Here, we review evidence from psychoneuroimmunology within the theoretical framework of allostatic load to conceptualize some of these associations. Interdisciplinary PNI research investigating the importance of psychological stress for the higher incidence of infections, decreased responses to vaccinations and delayed wound healing is reviewed. Furthermore, the literature supporting similar associations with regard to progression of oncological diseases and autoimmune disorders is reviewed with a focus on breast cancer and multiple sclerosis. The accumulating evidence regarding the importance of neuroendocrine-immune interaction in these diseases may thus lead to novel insights into pathogenetic mechanisms and could contribute to the development of novel preventive and therapeutic strategies.

Activation of the hypothalamic-pituitary-adrenal axis and autonomic nervous system during inflammation and altered programming of the neuroendocrine-immune axis during fetal and neonatal development: lessons learned from the model inflammagen, lipopolysaccharide

The hypothalamic-pituitary-adrenal axis (HPAA) and autonomic nervous system (ANS) are both activated during inflammation as an elaborate multi-directional communication pathway designed to restore homeostasis, in part, by regulating the inflammatory and subsequent immune response. During fetal and neonatal development programming of the HPAA, ANS and possibly the immune system is influenced by signals from the surrounding environment, as part of an adaptive mechanism to enhance the survival of the offspring. It is currently hypothesized that if this programming is either misguided, or the individual's environment is drastically altered such that neuroendocrine programming becomes maladaptive, it may contribute to the pathogenesis of certain diseases. Current research, suggests that exposure to inflammatory signals during critical windows of early life development may influence the programming of various genes within the neuroendocrine-immune axis. This review will provide, (1) an overview of the HPAA and ANS pathways that are activated during inflammation, highlighting studies that have used lipopolysaccharide as a model inflammagen and, (2) evidence to support the hypothesis that inflammatory stress during fetal and neonatal development can alter programming of the neuroendocrine-immune axis, influencing stress and immune responsiveness, and possibly disease resistance later in life.

Stress and disease progression in multiple sclerosis and its animal models

Since the first description of multiple sclerosis (MS) by Charcot, stress has been hypothesized to be a potential trigger of relapses. In recent years, data from observational studies in MS patients have provided some support for an association between stress and MS relapses. Furthermore, studies employing the MS animal model experimental autoimmune encephalomyelitis have shown that certain stressors can exacerbate the disease if administered prior to disease induction. Several lines of research have explored the 2 major stress response systems--the hypothalamic-pituitary-adrenal axis and the autonomic nervous system--and their relation to disease course in MS and experimental autoimmune encephalomyelitis. These studies provide evidence that insensitivity of the immune system to signals from these systems may play a role in inflammatory events. These findings can be integrated into a biological model of stress response system alterations in MS.

The role of stress-response systems for the pathogenesis and progression of MS

Disease progression in multiple sclerosis (MS)--an inflammatory demyelinating and neurodegenerative disease with a presumed T-cell driven autoimmune origin--has long been hypothesized to be associated with stress. However, this notion has only recently been supported by prospective clinical studies. Several clinical and molecular studies in MS and its animal models have recently shown disruptions in the communication between the immune system and the two major stress response systems, the hypothalamo-pituitary-adrenal (HPA) axis and the autonomic nervous system. Insensitivity to glucocorticoid and beta-adrenergic modulation might be involved in overshooting inflammation in MS, whereas hyperactivity of the HPA axis has been linked to neurodegeneration and increased disability. Here, we integrate findings from molecular, cellular, experimental, clinical and epidemiological research to describe the involvement of stress response systems in MS pathogenesis and progression.

Hypothalamo–pituitary–adrenal axis activity predicts disease progression in multiple sclerosis

Clinical studies have shown that groups of multiple sclerosis (MS) patients exhibit a chronically activated hypothalamo-pituitary-adrenal (HPA) axis. However, the association of HPA axis activity and disease progression in MS is unknown. In this longitudinal study over a 3-year follow-up period, we report that patients who exhibited stronger HPA reactivity at baseline were significantly more likely to experience progression as measured by the Expanded Disability Status Scale (EDSS) during the follow-up period. Furthermore, HPA axis activity correlated with progression ratings and cognitive impairment three years later. Tests of HPA axis activity may be useful biomarkers for disease progression in MS.

Effects of Interferon-β1a on the Hypothalamic-Pituitary-Adrenal Axis, Leukocyte Distribution and Mood States in Multiple Sclerosis Patients

Acute interferon-beta (IFN-beta) administration transiently activates the hypothalamic-pituitary-adrenal (HPA) axis, increases granulocytes, and reduces lymphocytes in peripheral blood. To test whether these effects are still present after long-term treatment, 13 patients with relapsing-remitting multiple sclerosis were analyzed at baseline, and 1, 2, 4, and 8 h after IFN-beta 1a injection at two occasions: at the initial administration and after 1 year of continuous treatment. Long-term treatment reduced the responsiveness of the HPA axis to the injection, and abolished the distributional changes in leukocyte numbers. One-year treatment with IFN-beta 1a did not induce mood alterations as assessed by the Profile of Mood States. These results suggest that long-term IFN-beta therapy has a profound impact on leukocyte distribution and the neuroendocrine response to the drug.

Involvement and role of the hypothalamo-pituitary-adrenal (HPA) stress axis in animal models of chronic pain and inflammation

Hypothalamo-pituitary-adrenal (HPA) axis changes have been reported in several disease states, including major depressive disorder, rheumatoid arthritis, multiple sclerosis and various other conditions associated with chronic pain. These observations suggest that stress and the HPA axis may play important roles in the pathology of these diseases. In order to contribute to a better understanding of the role that chronic stress may play in human pathology, this review article explores the involvement of the HPA axis in those animal models of chronic pain and inflammation that entail persistent rather than intermittent stress.