Loss of vagal integrity disrupts immune components of the microbiota-gut-brain axis and inhibits the effect of Lactobacillus rhamnosus on behavior and the corticosterone stress response.

The vagus nerve is one of the major signalling components between the gut microbiota and brain. However, the exact relationship between gut-brain signaling along the vagus and the effects of gut microbes on brain function and behaviour is unclear. In particular, the relationship between the vagus nerve and immune signaling, that also appears to play a critical role in microbiota-gut-brain communication, has not been delineated. The aim of the present study was to determine the effect of subdiaphragmatic vagotomy on peripheral and central immune changes associated with the anxiolytic actions of L.rhamnosus. Male mice underwent vagotomy or sham surgery, followed by administration of L.rhamnosus for 14 days. L.rhamnosus administration following sham surgery resulted in reduced anxiety-like behaviour, and an attenuation of the hypothalamic-pituitary-adrenal axis (HPA axis), as indicated by reduced plasma corticosterone after acute restraint stress. These effects were associated with an increase in splenic T regulatory cells and a decrease in activated microglia in the hippocampus. The anxiolytic effects, HPA modulation and increase in T regulatory cells were prevented by vagotomy, whereas vagotomy alone led to a significant increase in activated microglia in the hippocampus that was not altered with L.rhamnosus treatment. Thus, both microbe induced and constitutive vagal signaling influences critical immune components of the microbiota-gut-brain axis. These findings suggest that, rather than acting as a direct neural link to the central nervous system, the role of the vagus nerve in gut-microbe to brain signalling is as an integral component of a bi-directional neuroimmunoendocrine pathway.

Role of enhanced glucocorticoid receptor sensitivity in inflammation in PTSD: insights from computational model for circadian-neuroendocrine-immune interactions.

Although glucocorticoid resistance contributes to increased inflammation, individuals with posttraumatic stress disorder (PTSD) exhibit increased glucocorticoid receptor (GR) sensitivity along with increased inflammation. It is not clear how inflammation coexists with a hyperresponsive hypothalamic-pituitary-adrenal (HPA) axis. To understand this better, we developed and analyzed an integrated mathematical model for the HPA axis and the immune system. We performed mathematical simulations for a dexamethasone (DEX) suppression test and IC50-dexamethasone for cytokine suppression by varying model parameters. The model analysis suggests that increasing the steepness of the dose-response curve for GR activity may reduce anti-inflammatory effects of GRs at the ambient glucocorticoid levels, thereby increasing proinflammatory response. The adaptive response of proinflammatory cytokine-mediated stimulatory effects on the HPA axis is reduced due to dominance of the GR-mediated negative feedback on the HPA axis. To verify these hypotheses, we analyzed the clinical data on neuroendocrine variables and cytokines obtained from war-zone veterans with and without PTSD. We observed significant group differences for cortisol and ACTH suppression tests, proinflammatory cytokines TNFα and IL6, high-sensitivity C-reactive protein, promoter methylation of GR gene, and IC50-DEX for lysozyme suppression. Causal inference modeling revealed significant associations between cortisol suppression and post-DEX cortisol decline, promoter methylation of human GR gene exon 1F (NR3C1-1F), IC50-DEX, and proinflammatory cytokines. We noted significant mediation effects of NR3C1-1F promoter methylation on inflammatory cytokines through changes in GR sensitivity. Our findings suggest that increased GR sensitivity may contribute to increased inflammation; therefore, interventions to restore GR sensitivity may normalize inflammation in PTSD.

Neuroinflammation and depressive disorder: The role of the hypothalamus.

Data accumulated over the last two decades has demonstrated that hypothalamic inflammation plays an important role in the etiopathogenesis of the most prevalent diseases, such as cardiovascular diseases, metabolic syndrome, and even cancer. Recent findings indicate that hypothalamic inflammation is also associated with stress exposure and certain psychiatric diseases, such as depressive disorder. Mechanistic studies have shown that intense and/or chronic stress exposure is accompanied by the synthesis of inflammatory molecules in the hypothalamus, altered hypothalamic-pituitary-adrenal axis activity, and development of glucocorticoid resistance. Consequently, these factors might play a role in the etiopathogenesis of psychiatric disorders. We propose that hypothalamic inflammation represents an interconnection between somatic diseases and depressive disorder. These assumptions are discussed in this mini-review in the light of available data from studies focusing on hypothalamic inflammation.

An anti-CRF antibody suppresses the HPA axis and reverses stress-induced phenotypes.

Hypothalamic-pituitary-adrenal (HPA) axis dysfunction contributes to numerous human diseases and disorders. We developed a high-affinity monoclonal antibody, CTRND05, targeting corticotropin-releasing factor (CRF). In mice, CTRND05 blocks stress-induced corticosterone increases, counteracts effects of chronic variable stress, and induces other phenotypes consistent with suppression of the HPA axis. CTRND05 induces skeletal muscle hypertrophy and increases lean body mass, effects not previously reported with small-molecule HPA-targeting pharmacologic agents. Multiorgan transcriptomics demonstrates broad HPA axis target engagement through altering levels of known HPA-responsive transcripts such as Fkbp5 and Myostatin and reveals novel HPA-responsive pathways such as the Apelin-Apelin receptor system. These studies demonstrate the therapeutic potential of CTRND05 as a suppressor of the HPA axis and serve as an exemplar of a potentially broader approach to target neuropeptides with immunotherapies, as both pharmacologic tools and novel therapeutics.

[Effects of endogenous glucocorticoid deprivation on immune response of allergic rhinitis in mice].

Objective: To study the effect of dysfunction of the hypothalamic-pituitary-adrenal (HPA) axis on the pathogenesis of allergic rhinitis (AR) by the mouse model of decreased endogenous glucocorticoid (GC) after adrenalectomy, and further explore the mechanism of neural-endocrine regulation. Methods: According to literatures, adrenalectomized (ADX) mice and AR model were established. Eighty mice were randomly divided into four groups (n=20 per group) including control group, AR group of normal mice (AR group), AR group of bilateral ADX (bilateral ADX/AR group) and AR group of unilateral ADX (unilateral ADX/AR group). In order to assess the model of ADX, adrenal gland tissue was assayed by HE staining and the plasma adrenocorticotropic hormone (ACTH) and cortisol (CORT) concentrations were measured by enzyme-linked immunosorbent assay (ELISA). The behavioral observation, OVA-sIgE assessments and count of eosinophils/mast cells by the HE/Toluidine Blue staining of nasal septum mucosa tissue were performed to evaluate the AR model. The expression of peripheral blood CD4(+) IL4(+) T cells (Th2 cells) and CD4(+) IFN-γ(+) T cells (Th1 cells), splenocytes of CD4(+) CD25(+) Treg cells (Treg cells) were measured by flow cytometry to study the influence of endogenous GC on immunological indexes in different groups of mice. SPSS 16.0 software was used to analyze the data. Results: The concentrations of OVA-sIgE in control group, AR group, bilateral ADX/AR group and unilateral ADX/AR group mice were (28.86±3.62) ng/ml, (76.27±16.47) ng/ml, (48.37±8.89) ng/ml, (49.86±7.19) ng/ml, respectively. There was statistically significant difference between control group and AR group (t=7.09, P<0.05), AR group and bilateral ADX/AR group (t=4.81, P<0.05), AR group and unilateral ADX/AR group (t=5.21, P<0.05). The level of Th2 cells in different four groups were (0.71±0.24)%, (7.03±1.95)%, (2.44±2.06)%, (3.20±1.21)%, respectively. There was statistically significant difference between control group and AR group (t=-2.93, P<0.05), AR group and bilateral ADX/AR group (t=-4.67, P<0.05), AR group and unilateral ADX/AR group (t=-3.61, P<0.05). The expression of Th2 in bilateral ADX/AR group is lower than that in unilateral ADX/AR group without significant difference (t=4.39, P>0.05). Meanwhile, the level of Th1 cells in different four groups was (0.58±0.76)%, (0.57±0.59)%, (0.72±0.34)%, (1.03±0.32)%, respectively, with no significant difference among these groups. The proportion of Treg cells was (11.10±2.18)%, (4.10±1.07)%, (7.15±0.92)%, (4.58±1.05)%, respectively, with significant difference between control and other groups (t value was -7.171, -8.273, -8.360, respectively, all P<0.05). Compared with AR group, Treg cells increased significantly in bilateral ADX/AR group (t=-2.607, P<0.05). In addition, lower expression of eosinophil and mast cell were detected in the local nasal tissue of bilateral ADX/AR group, and mast cell degranulation wasn't be observed. Conclusion: Unilateral or bilateral ADX leads to HPA axis dysfunction and endogenous GC deprivation, possibly regulating the mechanism of AR through Th1/Th2 immune bias and Tregs cell' activity.

How stress contributes to autoimmunity-lessons from Sjögren's syndrome.

A large body of clinical evidence on the association between stressful life events and autoimmune diseases suggests that stress may play an important role in the pathogenesis of these disorders. In this article, we discuss the effects of stress, not on the immune system but on specific cell populations against which the autoimmune reactivity is directed. Using Sjögren's syndrome as a model autoimmune disease, we review the role of stress in the initiation and perpetuation of autoimmune reactivity. We present data that reveal the effects of stress on salivary gland epithelial cells, suggesting that stress can become immunogenic through its various effects on salivary gland epithelium.

The role of hypothalamic inflammation, the hypothalamic-pituitary-adrenal axis and serotonin in the cancer anorexia-cachexia syndrome.

PURPOSE OF REVIEW: In cancer patients, the development of cachexia (muscle wasting) is frequently aggravated by anorexia (loss of appetite). Their concurrence is often referred to as anorexia-cachexia syndrome. This review focusses on the recent evidence underlining hypothalamic inflammation as key driver of these processes. Special attention is given to the involvement of hypothalamic serotonin. RECENT FINDINGS: The anorexia-cachexia syndrome is directly associated with higher mortality in cancer patients. Recent reports confirm its severe impact on the quality of life of patients and their families.Hypothalamic inflammation has been shown to contribute to muscle and adipose tissue loss in cancer via central hypothalamic interleukine (IL)1ß-induced activation of the hypothalamic-pituitary-adrenal axis. The resulting release of glucocorticoids directly stimulates catabolic processes in these tissues via activation of the ubiquitin-proteosome pathway. Next to this, hypothalamic inflammation has been shown to reduce food intake in cancer by triggering changes in orexigenic and anorexigenic responses via upregulation of serotonin availability and stimulation of its signalling pathways in hypothalamic tissues. This combination of reduced food intake and stimulation of tissue catabolism represents a dual mechanism by which hypothalamic inflammation contributes to the development and maintenance of anorexia and cachexia in cancer. SUMMARY: Hypothalamic inflammation is a driving force in the development of the anorexia-cachexia syndrome via hypothalamic-pituitary-adrenal axis and serotonin pathway activation.

Hypothalamic-Pituitary-Adrenal Hypofunction in Myalgic Encephalomyelitis (ME)/Chronic Fatigue Syndrome (CFS) as a Consequence of Activated Immune-Inflammatory and Oxidative and Nitrosative Pathways.

There is evidence that immune-inflammatory and oxidative and nitrosative stress (O&NS) pathways play a role in the pathophysiology of myalgic encephalomyelitis (ME)/chronic fatigue syndrome (CFS). There is also evidence that these neuroimmune diseases are accompanied by hypothalamic-pituitary-adrenal (HPA) axis hypoactivity as indicated by lowered baseline glucocorticoid levels. This paper aims to review the bidirectional communications between immune-inflammatory and O&NS pathways and HPA axis hypoactivity in ME/CFS, considering two possibilities: (a) Activation of immune-inflammatory pathways is secondary to HPA axis hypofunction via attenuated negative feedback mechanisms, or (b) chronic activated immune-inflammatory and O&NS pathways play a causative role in HPA axis hypoactivity. Electronic databases, i.e., PUBMED, Scopus, and Google Scholar, were used as sources for this narrative review by using keywords CFS, ME, cortisol, ACTH, CRH, HPA axis, glucocorticoid receptor, cytokines, immune, immunity, inflammation, and O&NS. Findings show that activation of immune-inflammatory and O&NS pathways in ME/CFS are probably not secondary to HPA axis hypoactivity and that activation of these pathways may underpin HPA axis hypofunction in ME/CFS. Mechanistic explanations comprise increased levels of tumor necrosis factor-α, T regulatory responses with elevated levels of interleukin-10 and transforming growth factor-ß, elevated levels of nitric oxide, and viral/bacterial-mediated mechanisms. HPA axis hypoactivity in ME/CFS is most likely a consequence and not a cause of a wide variety of activated immune-inflammatory and O&NS pathways in that illness.

Regulation of hypothalamic-pituitary-adrenal axis activity and immunologic function contributed to the anti-inflammatory effect of acupuncture in the OVA-induced murine asthma model.

Asthma is a complex inflammatory disease of the airways and acupuncture is one of the effective therapies widely used to treat asthma in China. The aim of the study was to evaluate the regulatory role of acupuncture in airway inflammation and the hypothalamic-pituitary-adrenal (HPA) axis activity in OVA-induced murine asthma model. Our results demonstrated that acupuncture was effective in suppression of AHR, inhibition of total leukocyte, neutrophil, lymphocyte and eosinophil counts in BALF, attenuation of airway inflammation and TNF-α, IL-1ß, IL-5 and eotaxin secretion. Furthermore, the HPA axis activity was also regulated by acupuncture, which included promotion of adrenocorticotropic hormone and cortisol secretion in the plasma. Our findings revealed that acupuncture could attenuate airway inflammation and regulate HPA axis and immunologic function in the OVA-induced murine asthma model, which may provide support to better understand the contribution of acupuncture to the regulation of airway inflammation and HPA axis activity in asthma.

Evidence for increased immune mobilization in First Episode Psychosis compared with the prodromal stage in males.

The aim of the study was to gauge both the immune and neuroendocrine function in Ultra High Risk for psychosis (UHR) subjects and compare them with a cohort presenting with First Episode Psychosis (FEP). We recruited two groups, the first group consisted of 12 UHR males and the second of 25 males with FEP. We measured serum cortisol levels at 08:00, 12:00, 18:00 with their Area Under Curve with respect to the ground (AUCg) and the increase (AUCi) and we measured serum cytokines levels, Interleukin-1a, IL-1a, IL-2, IL-4,IL-5,IL-6,IL-8, IL-10,IL-12, IL-17a, Tumor Necrosis Factor-a (TNF-a), Interferon-γ (IFN-γ). Dexamethasone Suppression Test (DST) was also performed . The results suggest higher levels of both pro-inflammatory (TNF-a, IL-2, IL-12, IFN-γ) and anti-inflammatory (IL-10) cytokines in the FEP group compared with the UHR counterparts. Regarding the HPA axis function, the prodromal subjects showed a trend for higher AUCg and AUCi change/decrease cortisol levels. On the contrary, the DST results did not differ between the groups. No significant associations were demonstrated within each group among cytokines, cortisol and psychopathology. The findings favor a hypothesis of a relatively increased mobilization of both the pro- and anti-inflammatory cytokine networks, in FEP compared with that of UHR subjects.

Interleukin-1ß induced activation of the hypothalamus-pituitary-adrenal axis is dependent on interleukin-1 receptors on non-hematopoietic cells.

The proinflammatory cytokine interleukin-1ß (IL-1ß) plays a major role in the signal transduction of immune stimuli from the periphery to the central nervous system, and has been shown to be an important mediator of the immune-induced stress hormone release. The signaling pathway by which IL-1ß exerts this function involves the blood-brain-barrier and induced central prostaglandin synthesis, but the identity of the blood-brain-barrier cells responsible for this signal transduction has been unclear, with both endothelial cells and perivascular macrophages suggested as critical components. Here, using an irradiation and transplantation strategy, we generated mice expressing IL-1 type 1 receptors (IL-1R1) either in hematopoietic or non-hematopoietic cells and subjected these mice to peripheral immune challenge with IL-1ß. Following both intraperitoneal and intravenous administration of IL-1ß, mice lacking IL-1R1 in hematopoietic cells showed induced expression of the activity marker c-Fos in the paraventricular hypothalamic nucleus, and increased plasma levels of ACTH and corticosterone. In contrast, these responses were not observed in mice with IL-1R1 expression only in hematopoietic cells. Immunoreactivity for IL-1R1 was detected in brain vascular cells that displayed induced expression of the prostaglandin synthesizing enzyme cyclooxygenase-2 and that were immunoreactive for the endothelial cell marker CD31, but was not seen in cells positive for the brain macrophage marker CD206. These results imply that activation of the HPA-axis by IL-1ß is dependent on IL-1R1s on non-hematopoietic cells, such as brain endothelial cells, and that IL-1R1 on perivascular macrophages are not involved.

[The influence of immunization of rats with BSA-conjugated peptide 269-280 of type 3 melanocortin receptor on the metabolic parameters and thyroid functions].

One of the approaches to study the role of the brain hormonal signaling systems in the regulation of biochemical and physiological processes is their shutdown using the antibodies generated to peptides corresponding to extracellular regions of receptors. The brain type 3 melanocortin receptors (M3R) play an important role in the central regulation of the metabolism and the endocrine system. However, the influence of prolonged inhibition of M3R on energy metabolism, insulin resistance, and thyroid gland (TG) function is practically not studied. The aim of the study was to investigate the influence of prolonged repeated immunization of male rats with the BSA-conjugated peptide Ala-[Pro-Thr-Asn-Pro-Tyr-Cys-Ile-Cys-Thr-Thr-Ala-His269-280]-Ala (A[269- 280]A) corresponding to the third extracellular loop of M3R on their metabolic parameters and functional activity of TG. 9 months after the first immunization, the weight of rats was reduced and after 12-13 months was significantly lower than in controls. The weight of abdominal and brown adipose tissues, on the contrary, increased. At the same timeline there was an increase in the fasting glucose and insulin levels, and increase of the HOMA-IR index (by 75%) indicating that immunized animals develop insulin resistance. The rats have increased glucose utilization due to an increase of insulin production by pancreatic ß-cells. 12 months after the first immunization, the increase of the triglycerides level (by 74%) and the ratio of LDL- and HDL-cholesterol (by 36%) were revealed. 13 months after the start of immunization, the levels of free and total thyroxine and total triiodothyronine significantly decreased. In the TG plasma membranes of immunized rats the weakening adenylyl cyclase stimulating effect of thyroid-stimulating hormone was detected. Thus, long-term decrease in the bra- in M3R activity due to repeated immunization of rats with BSA-conjugated peptide A[269-280]A induces the disturbances of the peripheral metabolism and TG function.

Relationship between the induction of inflammatory processes and infectious diseases in patients with ischemic stroke.

Pro-inflammatory cytokines participate in the induction of ischemic stroke. So far, their participation in the cerebral ischemia was proven for the tumor necrosis factor TNF-α, interleukin-1 (IL-1), and interleukin-6 (IL-6). The release of the pro-inflammatory cytokines into the extracellular space causes the enlargement of the brain damage region, and consequently increases the neurological deficit and negatively affects the survival rate prognoses. That is confirmed by the increased concentration of pro-inflammatory cytokines in blood and the cerebrospinal fluid of patients with brain stroke, as well as by the research on the induced/experimental cerebral ischemia in animals. The pro-inflammatory cytokines participate in the migration of the reactive T lymphocytes to the regions of brain ischemia where they enhance the nerve tissue damage by down-regulation of microcirculation, induce the pro-thrombotic processes and release other neurotoxic cytokines. Also, in the early stage of cerebral ischemia, cytokines activate the axis hypothalamus-pituitary gland-adrenal cortex and increase the cortisol concentration in blood, what results in the decreased resistance to infectious diseases. Administration of the inhibitor of the interleukin-1 receptor (IL-1Ra) inhibits the inflammatory processes in the region of brain ischemia, and subsequently improves the prognosis for the size of the neurological deficit and the survival rate, as well as resistance to infectious diseases.

Operative care and surveillance in severe trauma patients. Interference between resuscitation treatments and anaesthesiology, and consequence on immunity.

Major trauma remains a worldwide cause of morbi-mortality. Early mortality is the consequence of hemorrhagic shock and traumatic brain injury. During early resuscitation, anaesthesia is often mandatory to perform surgery. It is mandatory to master the hemodynamic effects of hypnotic drugs in order to anticipate their potential deleterious effects in the setting of hemorrhagic shock. After early resuscitation, trauma patients present a high prevalence of nosocomial pneumonia, which sustains major morbidity. Nosocomial pneumonia are the consequence of an overwhelming systemic inflammatory response syndrome (SIRS) as well as a trauma-related immunosuppression. The administration of hemisuccinate of hydrocortisone modulates the SIRS and reduces the risk of nosocomial pneumonia as well as the length of mechanical ventilation. Finally in the operating theatre, fighting against hypothermia and un-anatomical positions, which can aggravate rhabdomyolysis, are both mandatory.

Hypothalamo-pituitary and immune-dependent adrenal regulation during systemic inflammation.

Inflammation-related dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis is central to the course of systemic inflammatory response syndrome or sepsis. The underlying mechanisms, however, are not well understood. Initial activation of adrenocortical hormone production during early sepsis depends on the stimulation of hypothalamus and pituitary mediated by cytokines; in late sepsis, there is a shift from neuroendocrine to local immune-adrenal regulation of glucocorticoid production. Therefore, the modulation of the local immune-adrenal cross talk, and not of the neuroendocrine circuits involved in adrenocorticotropic hormone production, may be more promising in the prevention of the adrenal insufficiency associated with prolonged sepsis. In the present work, we investigated the function of the crucial Toll-like receptor (TLR) adaptor protein myeloid differentiation factor 88 (MyD88) in systemic and local activation of adrenal gland inflammation and glucocorticoid production mediated by lipopolysachharides (LPSs). To this end, we used mice with a conditional MyD88 allele. These mice either were interbred with Mx1 Cre mice, resulting in systemic MyD88 deletion, predominantly in the liver and hematopoietic system, or were crossed with Akr1b7 Cre transgenic mice, resulting thereby in deletion of MyD88, which was adrenocortical-specific. Although reduced adrenal inflammation and HPA-axis activation mediated by LPS were found in Mx1(Cre+)-MyD88(fl/fl) mice, adrenocortical-specific MyD88 deletion did not alter the adrenal inflammation or HPA-axis activity under systemic inflammatory response syndrome conditions. Thus, our data suggest an important role of immune cell rather than adrenocortical MyD88 for adrenal inflammation and HPA-axis activation mediated by LPS.

Psychosocial stress and inflammation in cancer.

Stress-induced immune dysregulation results in significant health consequences for immune related disorders including viral infections, chronic autoimmune disease, and tumor growth and metastasis. In this mini-review we discuss the sympathetic, neuroendocrine and immunologic mechanisms by which psychosocial stress can impact cancer biology. Both human and animal studies have shown the sympathetic and neuroendocrine responses to psychosocial stress significantly impacts cancer, in part, through regulation of inflammatory mediators. Psychosocial stressors stimulate neuroendocrine, sympathetic, and immune responses that result in the activation of the hypothalamic-pituitary-adrenal (HPA)-axis, sympathetic nervous system (SNS), and the subsequent regulation of inflammatory responses by immune cells. Social disruption (SDR) stress, a murine model of psychosocial stress and repeated social defeat, provides a novel and powerful tool to probe the mechanisms leading to stress-induced alterations in inflammation, tumor growth, progression, and metastasis. In this review, we will focus on SDR as an important model of psychosocial stress in understanding neural-immune mechanisms in cancer.

Neuroimmunoendocrine regulation of the prion protein in neutrophils.

The prion protein (PrP(C)) is a cell surface protein expressed mainly in the nervous system. In addition to the role of its abnormal conformer in transmissible spongiform encephalopathies, normal PrP(C) may be implicated in other degenerative conditions often associated with inflammation. PrP(C) is also present in cells of hematopoietic origin, including T cells, dendritic cells, and macrophages, and it has been shown to modulate their functions. Here, we investigated the impact of inflammation and stress on the expression and function of PrP(C) in neutrophils, a cell type critically involved in both acute and chronic inflammation. We found that systemic injection of LPS induced transcription and translation of PrP(C) in mouse neutrophils. Up-regulation of PrP(C) was dependent on the serum content of TGF-ß and glucocorticoids (GC), which, in turn, are contingent on the activation of the hypothalamic-pituitary-adrenal axis in response to systemic inflammation. GC and TGF-ß, either alone or in combination, directly up-regulated PrP(C) in neutrophils, and accordingly, the blockade of GC receptors in vivo curtailed the LPS-induced increase in the content of PrP(C). Moreover, GC also mediated up-regulation of PrP(C) in neutrophils following noninflammatory restraint stress. Finally, neutrophils with up-regulated PrP(C) presented enhanced peroxide-dependent cytotoxicity to endothelial cells. The data demonstrate a novel interplay of the nervous, endocrine, and immune systems upon both the expression and function of PrP(C) in neutrophils, which may have a broad impact upon the physiology and pathology of various organs and systems.

The neuroimmune connection interferes with tissue regeneration and chronic inflammatory disease in the skin.

Research over the past decades has revealed close interactions between the nervous and immune systems that regulate peripheral inflammation and link psychosocial stress with chronic somatic disease. Besides activation of the sympathetic and the hypothalamus-pituitary-adrenal axis, stress leads to increased neurotrophin and neuropeptide production in organs at the self-environment interface. The scope of this short review is to discuss key functions of these stress mediators in the skin, an exemplary stress-targeted and stress-sensitive organ. We will focus on the skin's response to acute and chronic stress in tissue regeneration and pathogenesis of allergic inflammation, psoriasis, and skin cancer to illustrate the impact of local stress-induced neuroimmune interaction on chronic inflammation.

Endocrine alterations in primary Sjogren's syndrome: an overview.

Involvement of several components of the endocrine system has been proposed as significant player in primary Sjogren's syndrome (SS) pathogenesis and clinical expression. Hypoactivity of the hypothalamic-pituitary-adrenal (HPA) axis has been previously demonstrated in patients with primary SS as a result either of a pituitary defect and/or of adrenal gland dysfunction. In support of the latter hypothesis, antibodies to 21-hydroxylase (OH)--a marker of autoimmune adrenal disease--have been detected in sera from approximately one fifth of primary SS patients, in association with B-cell activating cytokines and adrenal hyporesponsiveness. As a result of HPA hypofunction, adrenal androgens and particularly dehydroepiandrosterone-sulfate (DHEA-S) have been reportedly low in primary SS individuals. Epithelial salivary gland cells undergo apoptosis in lack of both estrogens and active androgens. In the absence of a compensatory action of the latter, menopausal status can lead to salivary gland apoptotic process triggering an aberrant immune response. On the other hand, given that salivary gland tissue remodeling has been shown to be under androgenic control, the observed androgen deficiency in these patients might account for the observed alterations in the salivary gland architecture. Heightened serum and salivary gland tissue prolactin levels in primary SS patients have been also suggested as contributors in disease pathogenesis. Finally, autoimmune thyroid disease (ATD) occurs quiet commonly in the setting of primary SS and subclinical hypothyroidism is the main functional abnormality observed in these patients.