Neural regulation of innate immunity: a coordinated nonspecific host response to pathogens

The Biological Residue of Childhood Poverty

Children raised in poverty are prone to physical health problems late in life. To understand these findings and address the scientific challenge they represent, we must formulate integrative conceptual frameworks at the crossroads of behavioral and biomedical science, with a strong developmental emphasis. In this article, we outline such a framework and discuss research bearing on its validity. We address how childhood poverty gets under the skin, at the level of tissues and organs, in a manner that affects later disease risks. We also tackle questions about resilience; Even with lengthy exposure to childhood poverty, why do only a subset of people acquire diseases? Why are some individuals protected while others remain vulnerable? Maternal nurturance might be a source of resilience, buffering children from the long-term health consequences of poverty. We conclude with research priorities.

Metallothioneins I/II expression in rat strains with genetically different susceptibility to experimental autoimmune encephalomyelitis

OBJECTIVES

Compared to the Dark Agouti (DA), the Albino Oxford (AO) rat strain exhibits lower susceptibility to the induction of experimental autoimmune encephalomyelitis (EAE). Here, we investigated the potential contribution of the heavy metal-binding proteins metallothioneins (MTs) I/II to these effects.

METHODS

Rats were immunized with bovine brain homogenate emulsified in complete Freund's adjuvant or only with complete Freund's adjuvant. The expression patterns of MTs mRNA and proteins and tissue concentrations of Zn2+ and Cu2+ were estimated in the brain and in the liver on days 7 and 12 after immunization, by real-time PCR, immunohistochemistry and inductively coupled plasma spectrometry, respectively. Additionally, the hepatic transforming growth factor beta and nuclear factor kappa B immunoreactivities were tested.

RESULTS

Clinical signs of EAE were not induced in AO rats, but they upregulated the expression of MT I/II proteins in the brain (hippocampus and cerebellum) and in the liver, similarly as DA rats. The transcriptional activation of MT-I occurred, however, only in DA rats, which accumulated also more zinc in the brain and in the liver. In contrast, intact AO rats had greater hepatic MT-I mRNA immunoreactivity and more Cu2+ in the hippocampus. Besides, in immunized AO rats a high upregulation of transforming growth factor beta and nuclear factor kappa B immunoreactivities was found in several hepatic structures (vascular endothelium, Kupffer cells and hepatocytes).

CONCLUSIONS

Our data show that AO and DA rats differ in constitutive and inductive MT-I gene expression in the brain and in the liver, as well as in the hepatic cytokine profile, suggesting that these mechanisms may contribute to the discrepancy in the susceptibility to EAE.

The clinical importance of the anti-inflammatory vagovagal reflex

Excessive activation of the immune system is prevented by anti-inflammatory mediators such as corticosteroids and anti-inflammatory cytokines. Recently, it became clear that the brain not only senses peripheral inflammation through vagal afferent nerve fibers, but also provides an integrated response dampening the immune system through vagal efferents. This so-called anti-inflammatory pathway has been introduced as a third system by which the immune system is modulated. In sepsis, the anti-inflammatory effect is mediated by modulation of splenic macrophages, whereas in the gut, vagal nerve fibers synapse with enteric cholinergic neurons interacting with resident intestinal macrophages. In this chapter, the preclinical data underscoring the importance of this pathway are summarized, and its clinical significance is reviewed. Finally, the current data supporting its relevance to human disease and its therapeutic potential will be discussed. Insight in the mechanisms underlying these crucial properties will lead to better understanding of immune-mediated diseases and ultimately to improved anti-inflammatory therapies.

Efficacy of a children's procedural preparation and distraction device on healing in acute burn wound care procedures: study protocol for a randomized controlled trial

Background

The intense pain and anxiety triggered by burns and their associated wound care procedures are well established in the literature. Non-pharmacological intervention is a critical component of total pain management protocols and is used as an adjunct to pharmacological analgesia. An example is virtual reality, which has been used effectively to dampen pain intensity and unpleasantness. Possible links or causal relationships between pain/anxiety/stress and burn wound healing have previously not been investigated. The purpose of this study is to investigate these relationships, specifically by determining if a newly developed multi-modal procedural preparation and distraction device (Ditto™) used during acute burn wound care procedures will reduce the pain and anxiety of a child and increase the rate of re-epithelialization.

Methods/design

Children (4 to 12 years) with acute burn injuries presenting for their first dressing change will be randomly assigned to either the (1) Control group (standard distraction) or (2) Ditto™ intervention group (receiving Ditto™, procedural preparation and Ditto™ distraction). It is intended that a minimum of 29 participants will be recruited for each treatment group. Repeated measures of pain intensity, anxiety, stress and healing will be taken at every dressing change until complete wound re-epithelialization. Further data collection will aid in determining patient satisfaction and cost effectiveness of the Ditto™ intervention, as well as its effect on speed of wound re-epithelialization.

Discussion

Results of this study will provide data on whether the disease process can be altered by reducing stress, pain and anxiety in the context of acute burn wounds.

Trial registration

ACTRN12611000913976

Potential role of HPA axis and sympathetic nervous responses in depletion of B cells induced by H9N2 avian influenza virus infection

Except severe pulmonary disease caused by influenza virus infection, an impaired immune system is also a clinic characteristic. However, the mechanism(s) of influenza virus infection-induced depletion of B cells was unknown. Here, we compared the effect of two variant virulence H9N2 virus infections on mouse B cells. Our study found that the infection with highly pathogenic virus (V) of led to depletion of spleen B cells and bone marrow (BM) early B cells, compared to lowly pathogenic virus (Ts). Moreover, high apoptosis and cell cycle arrest in spleen and BM were detected, suggesting important factors for the reduction of B cells in both organs. Further, this effect was not caused by virus replication in spleen and BM. Compared to Ts virus infection, V virus resulted in higher glucocorticoids (GCs) and lower leptin level in plasma. Intraperitoneal GCs receptor antagonist RU486 injection was sufficient to prevent the loss of spleen B cell and BM pro- and immature B cells, but similar result was not observed in leptin-treated mice. Depletion of spleen B cells and BM pro-B cells was also reversed by chemical sympathectomy mediated by the norepinephrine (NE) analog 6-hydroxydopamine (6-OHDA), but the treatment didn't affect the GCs level. This study demonstrated that depletion of B cells induced by H9N2 AIV was dependent on HPA axis and sympathetic response.

Exaggerated neurobiological sensitivity to threat as a mechanism linking anxiety with increased risk for diseases of aging

Anxiety disorders increase risk for the early development of several diseases of aging. Elevated inflammation, a common risk factor across diseases of aging, may play a key role in the relationship between anxiety and physical disease. However, the neurobiological mechanisms linking anxiety with elevated inflammation remain unclear. In this review, we present a neurobiological model of the mechanisms by which anxiety promotes inflammation. Specifically we propose that exaggerated neurobiological sensitivity to threat in anxious individuals may lead to sustained threat perception, which is accompanied by prolonged activation of threat-related neural circuitry and threat-responsive biological systems including the hypothalamic-pituitary-adrenal (HPA) axis, autonomic nervous system (ANS), and inflammatory response. Over time, this pattern of responding can promote chronic inflammation through structural and functional brain changes, altered sensitivity of immune cell receptors, dysregulation of the HPA axis and ANS, and accelerated cellular aging. Chronic inflammation, in turn, increases risk for diseases of aging. Exaggerated neurobiological sensitivity to threat may thus be a treatment target for reducing disease risk in anxious individuals.

The neuroendocrine control of the innate immune system in health and brain diseases

The innate immune reaction takes place in the brain during immunogenic challenges, injury, and disease. Such a response is highly regulated by numerous anti-inflammatory mechanisms that may directly affect the ultimate consequences of such a reaction within the cerebral environment. The neuroendocrine control of this innate immune system by glucocorticoids is critical for the delicate balance between cell survival and damage in the presence of inflammatory mediators. Glucocorticoids play key roles in regulating the expression of inflammatory genes, and they also have the ability to modulate numerous functions that may ultimately lead to brain damage or repair after injury. Here we review these mechanisms and discuss data supporting both neuroprotective and detrimental roles of the neuroendocrine control of innate immunity.

Experimental endotoxemia as a model to study neuroimmune mechanisms in human visceral pain

The administration of bacterial endotoxin (i.e., lipopolysaccharide, LPS) constitutes a well-established experimental approach to study the effects of an acute and transient immune activation on physiological, behavioral, and emotional aspects of sickness behavior in animals and healthy humans. However, little is known about possible effects of experimental endotoxemia on pain in humans. This knowledge gap is particularly striking in the context of visceral pain in functional as well as chronic-inflammatory gastrointestinal disorders. Although inflammatory processes have been implicated in the pathophysiology of visceral pain, it remains incompletely understood how inflammatory mediators interact with bottom-up (i.e., increased afferent input) and top-down (i.e., altered central pain processing) mechanisms of visceral hyperalgesia. Considering the recent findings of visceral hyperalgesia after LPS application in humans, in this review, we propose that experimental endotoxemia with its complex peripheral and central effects constitutes an experimental model to study neuroimmune communication in human pain research. We summarize and attempt to integrate relevant animal and human studies concerning neuroimmune communication in visceral and somatic pain, discuss putative mechanisms, and conclude with future research directions.

Intranasal rapamycin rescues mice from staphylococcal enterotoxin B-induced shock

Staphylococcal enterotoxin B (SEB) and related exotoxins produced by Staphylococcus aureus are potent activators of the immune system and cause toxic shock in humans. Currently there is no effective treatment except for the use of intravenous immunoglobulins administered shortly after SEB exposure. Intranasal SEB induces long-lasting lung injury which requires prolonged drug treatment. We investigated the effects of rapamycin, an immunosuppressive drug used to prevent graft rejection, by intranasal administration in a lethal mouse model of SEB-induced shock. The results show that intranasal rapamycin alone delivered as late as 17 h after SEB protected 100% of mice from lethal shock. Additionally, rapamycin diminished the weight loss and temperature fluctuations elicited by SEB. Intranasal rapamycin attenuated lung MCP-1, IL-2, IL-6, and IFNγ by 70%, 30%, 64%, and 68% respectively. Furthermore, short courses (three doses) of rapamycin were sufficient to block SEB-induced shock. Intranasal rapamycin represents a novel use of an immunosuppressant targeting directly to site of toxin exposure, reducing dosages needed and allowing a wider therapeutic window.

Mind-altering microorganisms: the impact of the gut microbiota on brain and behaviour

Recent years have witnessed the rise of the gut microbiota as a major topic of research interest in biology. Studies are revealing how variations and changes in the composition of the gut microbiota influence normal physiology and contribute to diseases ranging from inflammation to obesity. Accumulating data now indicate that the gut microbiota also communicates with the CNS--possibly through neural, endocrine and immune pathways--and thereby influences brain function and behaviour. Studies in germ-free animals and in animals exposed to pathogenic bacterial infections, probiotic bacteria or antibiotic drugs suggest a role for the gut microbiota in the regulation of anxiety, mood, cognition and pain. Thus, the emerging concept of a microbiota-gut-brain axis suggests that modulation of the gut microbiota may be a tractable strategy for developing novel therapeutics for complex CNS disorders.

Activation of vagus nerve by semapimod alters substance P levels and decreases breast cancer metastasis

Chronic inflammation is involved in initiation as well as in progression of cancer. Semapimod, a tetravalent guanylhydrazon and formerly known as CNI-1493, inhibits the release of inflammatory cytokines from activated macrophages and this effect is partly mediated by the vagus nerve. Our previous findings demonstrated that inactivation of vagus nerve activity as well sensory neurons enhanced visceral metastasis of 4THM breast carcinoma. Hence semapimod by activating vagus nerve may inhibit breast cancer metastasis. Here, effects of semapimod on breast cancer metastasis, the role of vagal sensory neurons on this effect and changes in mediators of the neuroimmune connection, such as substance P (SP) as well as neprilysin-like activity, were examined. Vagotomy was performed on half of the control animals that were treated with semapimod following orthotopic injection of 4THM breast carcinoma cells. Semapimod decreased lung and liver metastases in control but not in vagotomized animals with an associated increased SP levels in sensory nerve endings. Semapimod also increased neprilysin-like activity in lung tissue of control animals but not in tumor-bearing animals. This is the first report demonstrating that semapimod enhances vagal sensory nerve activity and may have anti-tumoral effects under in-vivo conditions. Further studies, however, are required to elucidate the conditions and the mechanisms involved in anti-tumoral effects of semapimod.

Interactions between Streptococcus pneumoniae and influenza virus: a mutually beneficial relationship?

Historically, most research on infectious diseases has focused on infections with single pathogens. However, infections with pathogens often occur in the context of pre-existing viral and bacterial infections. Clinically, this is of particular relevance for coinfections with Streptococcus pneumoniae and influenza virus, which together are an important cause of global morbidity and mortality. In recent years new evidence has emerged regarding the underlying mechanisms of influenza virus-induced susceptibility to secondary pneumococcal infections, in particular regarding the sustained suppression of innate recognition of S. pneumoniae. Conversely, it is also increasingly being recognized that there is not a unidirectional effect of the virus on S. pneumoniae, but that asymptomatic pneumococcal carriage may also affect subsequent influenza virus infection and the clinical outcome. Here, we will review both aspects of pneumococcal influenza virus infection, with a particular focus on the age-related differences in pneumococcal colonization rates and invasive pneumococcal disease.

Enhanced phosphorylation of MAPKs by NE promotes TNF-α production by macrophage through α adrenergic receptor

The aim of this study was to investigate whether norepinephrine (NE) could regulate macrophage production of tumor necrosis factor alpha (TNF-α) by influencing the phosphorylation of mitogen-activated protein kinases (MAPKs). Primary macrophages from male BALB/c mice were applied to explore the mechanism by which NE influences the the secretion of TNF-α when macrophages were activated by lipopolysaccharides (LPS). We found that NE could increase crophage production of TNF-α when macrophages were activated by LPS, and this effect could be inhibited by α adrenergic antagonist phentolamine. Also, NE could increase the phosphorylation of c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinases (ERK), and p38, through α receptor. Furthermore, JNK inhibitor SP600125, ERK inhibitor U0126, and p38 inhibitor SB203580 could all partially counteract NE's effect on the phosphorylation of MAPKs, as well as TNF-α production by macrophages. This study revealed that as macrophages were activated by LPS, NE promoted the secretion of inflammatory factors by increasing the phosphorylation of MAPKs through an α receptor-dependent pathway. Our results provide the evidence of a relationship between stress and diseases, as well as the mechanism by which stress induces or affects the inflammation-related diseases.

Lower stress system activity and higher peripheral inflammation in competitive ballroom dancers

Although regular physical exercise is beneficial for health, competitive ballroom dancers anecdotally report increased disease susceptibility. This study aims to uncover possible biological mechanisms and pathways that may lead to higher disease susceptibility in a population of otherwise healthy young athletes. Experienced ballroom dancers and healthy controls provided blood and saliva samples in order to assess diurnal cortisol and alpha-amylase (sAA) output as well as inflammatory parameters interleukin (IL)-6 and C-reactive protein (CRP). We found diurnal cortisol and sAA output to be significantly lower in dancers. Additionally, higher levels in IL-6 but not in CRP were shown in dancers. Dancers described themselves as being more anxious and reported more physical health complaints. Competitive ballroom dancers show evidence for hypoactivity in stress systems and peripheral inflammation along with more self-reported physical complaints. Therefore, competitive ballroom dancing represents a chronic stressor that can lead to important functional consequences. It remains to be investigated whether these alterations are causally related to health.

Monitoring of the course of sepsis in hematooncological patients by extrapituitary prolactin expression in peripheral blood monocytes

Our study explored the role of extrapituitary prolactin (PRL) and toll-like receptors (TLR)2 and TLR4 in defense reaction of immune system to bacterial infection. Forty-two patients diagnosed with sepsis were recruited and blood samples were withdrawn after patients' admission to hospital, after the end of acute phase of sepsis and after the sepsis has been resolved, respectively. Seventeen patients died of sepsis; thus, only one sample collected just before death could be processed. PRL and TLR2/4 mRNA levels were measured in CD14+ blood monocytes by QPCR and PRL -1149 G/T SNP genotyped. The TLRs mRNA expression was markedly elevated in all patients groups in comparison to healthy controls mRNA levels; the highest upregulation of monocytic TLR2 in sepsis (16.4 times, P<0.0001) was detected in patients who did not survive septic complications. PRL mRNA expression in monocytes from non-survivors tended to be lower (4.5 fold decrease, P=NS) compared to control levels and it was 6.2 times reduced compared to PRL mRNA expression in second blood sample from survivors (P<0.05). The PRL -1149 G/T SNP had no effect on PRL mRNA response during sepsis. Our data suggest that increased prolactin mRNA expression in monocytes is associated with better outcome and improved survival rate in sepsis with no apparent effect of PRL -1149 G/T SNP on monocytic prolactin response.

Endoplasmic reticulum stress pathway required for immune homeostasis is neurally controlled by arrestin-1

In response to pathogen infection, the host innate immune system activates microbial killing pathways and cellular stress pathways that need to be balanced because insufficient or excessive immune responses have deleterious consequences. Recent studies demonstrate that two G protein-coupled receptors (GPCRs) in the nervous system of Caenorhabditis elegans control immune homeostasis. To investigate further how GPCR signaling controls immune homeostasis at the organismal level, we studied arrestin-1 (ARR-1), which is the only GPCR adaptor protein in C. elegans. The results indicate that ARR-1 is required for GPCR signaling in ASH, ASI, AQR, PQR, and URX neurons, which control the unfolded protein response and a p38 mitogen-activated protein kinase signaling pathway required for innate immunity. ARR-1 activity also controlled immunity through ADF chemosensory and AFD thermosensory neurons that regulate longevity. Furthermore, we found that although ARR-1 played a key role in the control of immunity by AFD thermosensory neurons, it did not control longevity through these cells. However, ARR-1 partially controlled longevity through ADF neurons.

The characterization of a concentration-sensitive α-adrenergic-like octopamine receptor found on insect immune cells and its possible role in mediating stress hormone effects on immune function

Octopamine (OA), the insect equivalent of norepinephrine, links the nervous system and immune system in insects. This study examines the underlying molecular mechanisms (i.e. second messenger systems) mediating OA effects on insect immune cells. At low concentrations (<1μM), OA stimulatedhemocyte spreading and phagocytosis in the larval Lepidopteran (caterpillar) Chilo suppressalis, whereas at high concentrations (>10 μM), OA inhibited hemocyte spreading and phagocytosis. Similarly, OA concentration had differential effects on two intracellular signaling pathways, Ca(2+) and cAMP. Low concentrations of OA increased intracellular Ca(2+), but only high concentrations of OA (>1 μM) led to an increase in both Ca(2+) and cAMP. We identified an α-adrenergic-like octopamine receptor in this species (CsOA1) and confirmed that it is expressed in hemocytes. After heterologous expression in HEK-293 cells, the CsOA1 receptor produced the same OA concentration-dependent responses on intracellular Ca(2+) and cAMP as had been observed in hemocytes. These findings support earlier work showing that OA has both stimulatory and suppressive effects on immune responses, depending on the OA concentration. Our evidence suggests that these biphasic effects are mediated by an octopamine receptor signaling through intracellular Ca(2+) and cAMP second messenger pathways. Stress hormones/neuromodulators have complex effects on immune function in animals across phyla. This complexity may be mediated, in part, by conserved connections between adrenergic-like G-coupled protein receptors and second messenger systems.

An iodothyronine deiodinase from Chlamys farreri and its induced mRNA expression after LPS stimulation

Iodothyronine deiodinase is responsible for the deiodination of thyroxine T4 to T3, and involved in the complex neuroendocrine-immune regulatory network to optimize the immune response in vertebrate. In this study, the full-length cDNA of an iodothyronine deiodinase (designated as CfDx) was cloned from scallop Chlamys farreri. The complete cDNA sequence of CfDx was of 1404 bp and contained an open reading frame of 900 bp encoding a polypeptide of 299 amino acids. The deduced amino acid sequence of CfDx contained an in-frame TGA stop codon probably encoding an essential selenocysteine (SeC), and there was a conserved region of about 15 amino acids surrounding the SeC residue. The CfDx mRNA transcripts were detected in all the tested tissues, including haemocytes, hepatopancreas, kidney, adductor muscle, gonad, gill and mantle, with the higher expression level in hepatopancreas and kidney. After LPS stimulation, the CfDx mRNA expression level in haemocytes increased significantly at 12 h (25.35-fold, P < 0.05) and 24 h (7.62-fold, P < 0.05), and the concentration of T3 in haemolymph increased significantly at 12 h (3.62 ng dL(-1), P < 0.05) even the concentration of T4 did not change significantly. After scallop received an injection of 50 μg CfDx dsRNA, the expression level of CfDx mRNA in haemocytes began to decrease significantly at 36 h and maintained the relative low level (about 0.3-fold of the PBS control group) from 36 to72 h, but the ratio of T4/T3 in haemolymph began to increase at 36 h (2.31-fold, P < 0.05) and kept increasing from 36 to 72 h comparing with that in the PBS control group. These results indicated that CfDx was a homologue of iodothyronine deiodinase in scallop C. farreri, and it might be involved in the immunomodulation via regulating the concentration of thyroid hormones T3 and T4 in the haemolymph of scallop.

A changing perspective on the role of neuroinflammation in Alzheimer's disease

Alzheimer's disease (AD) is a complex, neurodegenerative disorder characterized by the presence of amyloid plaques and neurofibrillary tangles in the brain. Glial cells, particularly microglial cells, react to the presence of the amyloid plaques and neurofibrillary tangles producing an inflammatory response. While once considered immunologically privileged due to the blood-brain barrier, it is now understood that the glial cells of the brain are capable of complex inflammatory responses. This paper will discuss the published literature regarding the diverse roles of neuroinflammation in the modulation of AD pathologies. These data will then be related to the well-characterized macrophage phenotypes. The conclusion is that the glial cells of the brain are capable of a host of macrophage responses, termed M1, M2a, M2b, and M2c. The relationship between these states and AD pathologies remains relatively understudied, yet published data using various inflammatory stimuli provides some insight. It appears that an M1-type response lowers amyloid load but exacerbates neurofibrillary tangle pathology. In contrast, M2a is accompanied by elevated amyloid load and appears to ameliorate, somewhat, neurofibrillary pathology. Overall, it is clear that more focused, cause-effect studies need to be performed to better establish how each inflammatory state can modulate the pathologies of AD.

Role of transcriptional coregulator GRIP1 in the anti-inflammatory actions of glucocorticoids

Inhibition of cytokine gene expression by the hormone-activated glucocorticoid receptor (GR) is the key component of the anti-inflammatory actions of glucocorticoids, yet the underlying molecular mechanisms remain obscure. Here we report that glucocorticoid repression of cytokine genes in primary macrophages is mediated by GR-interacting protein (GRIP)1, a transcriptional coregulator of the p160 family, which is recruited to the p65-occupied genomic NFκB-binding sites in conjunction with liganded GR. We created a mouse strain enabling a conditional hematopoietic cell-restricted deletion of GRIP1 in adult animals. In this model, GRIP1 depletion in macrophages attenuated in a dose-dependent manner repression of NFκB target genes by GR irrespective of the upstream Toll-like receptor pathway responsible for their activation. Furthermore, genome-wide transcriptome analysis revealed a broad derepression of lipopolysaccharide (LPS)-induced glucocorticoid-sensitive targets in GRIP1-depleted macrophages without affecting their activation by LPS. Consistently, conditional GRIP1-deficient mice were sensitized, relative to the wild type, to a systemic inflammatory challenge developing characteristic signs of LPS-induced shock. Thus, by serving as a GR corepressor, GRIP1 facilitates the anti-inflammatory effects of glucocorticoids in vivo.

Neuroimmune crosstalk in the central nervous system and its significance for neurological diseases

The central nervous system (CNS) is now known to actively communicate with the immune system to control immune responses both centrally and peripherally. Within the CNS, while studies on glial cells, especially microglia, have highlighted the importance of this cell type in innate immune responses of the CNS, the immune regulatory functions of other cell types, especially neurons, are largely unknown. How neuroimmune cross-talk is homeostatically maintained in neurodevelopment and adult plasticity is even more elusive. Inspiringly, accumulating evidence suggests that neurons may also actively participate in immune responses by controlling glial cells and infiltrated T cells. The potential clinical application of this knowledge warrants a deeper understanding of the mutual interactions between neurons and other types of cells during neurological and immunological processes within the CNS, which will help advance diagnosis, prevention, and intervention of various neurological diseases. The aim of this review is to address the immune function of both glial cells and neurons, and the roles they play in regulating inflammatory processes and maintaining homeostasis of the CNS.

The expression of dopa decarboxylase and dopamine beta hydroxylase and their responding to bacterial challenge during the ontogenesis of scallop Chlamys farreri

Dopa decarboxylase (DDC) and dopamine beta hydroxylase (DBH) is responsible for the synthesis of dopamine and norepinephrine, respectively. In the present study, dopa decarboxylase (CfDDC) and dopamine beta hydroxylase (CfDBH) were selected as indicator to investigate the development of catecholaminergic nervous system in the larvae of scallop Chlamys farreri. The CfDDC and CfDBH transcripts were all detectable during the whole ontogenesis expect for the CfDDC transcripts in 2-cell embryos stage. The expression level of CfDDC and CfDBH mRNA increased significantly in the veliger stage, and reached the peak in late (35.64-fold, P < 0.05) and mid-veliger (400.21-fold, P < 0.05) larvae, respectively. By immunofluorescence, two CfDDC immunoreactive areas were observed in the trochophore and D-hinged larvae, and then three CfDDC immunoreactive areas and two immunopositive fibres formed in early and late veliger larvae, respectively. Two CfDBH immunopositive fibers appeared initially in the early D-hinged stage, and another two similar fibers developed in the late D-hinged stage. The bacteria Vibrio anguillarum challenge could induce the mRNA expression of CfDDC and CfDBH in different developmental stage. The significantly increase of CfDDC mRNA was observed in the trochophore larvae at 12 h (8.61-fold, P < 0.05) and in late D-hinged larvae at 24 h (1.56-fold, P < 0.05) post challenge. The expression level of CfDBH mRNA decreased significantly in late D-hinged larvae at 6 h (0.45-fold, P < 0.05), whereas it increased significantly in late veliger larvae at 12 h after bacterial challenge (14.52-fold, P < 0.05). These results concluded that the scallop catecholaminergic nervous system appeared firstly as the form of dopaminergic neurons in the trochophore larvae, and the developing catecholaminergic nervous system in the trochophore, D-hinged and veliger larvae of scallop could respond to the immune stimulation in different patterns.

Glucocorticoid regulation of inflammation and its functional correlates: from HPA axis to glucocorticoid receptor dysfunction

Enhanced susceptibility to inflammatory and autoimmune disease can be related to impairments in HPA axis activity and associated hypocortisolism, or to glucocorticoid resistance resulting from impairments in local factors affecting glucocorticoid availability and function, including the glucocorticoid receptor (GR). The enhanced inflammation and hypercortisolism that typically characterize stress-related illnesses, such as depression, metabolic syndrome, cardiovascular disease, or osteoporosis, may also be related to increased glucocorticoid resistance. This review focuses on impaired GR function as a molecular mechanism of glucocorticoid resistance. Both genetic and environmental factors can contribute to impaired GR function. The evidence that glucocorticoid resistance can be environmentally induced has important implications for management of stress-related inflammatory illnesses and underscores the importance of prevention and management of chronic stress. The simultaneous assessment of neural, endocrine, and immune biomarkers through various noninvasive methods will also be discussed.

Stress-related programming of autonomic imbalance: role in allergy and asthma

Evidence linking psychological stress to allergy has grown with our increased understanding of the natural history and pathophysiology of these disorders and the neurobiology of stress vulnerability. However, the specific pathways that increase vulnerability to developing allergy and associated disorders remain to be elucidated. Autonomic nervous system functioning (autonomic balance) has been implicated in allergy for some time albeit links between autonomic balance and immune function in early development have been under studied. Starting in utero, stress may influence the programming of brain neurotransmitter systems, sympathetic and parasympathetic nervous system functioning, and the hypothalamic-pituitary-adrenal axis, which in turn may alter neural regulation of immune function. Epigenetic dysregulation of gene expression may be a fundamental mechanism for programming of early neural-immune processes.

Neural reflexes in inflammation and immunity

The mammalian immune system and the nervous system coevolved under the influence of infection and sterile injury. Knowledge of homeostatic mechanisms by which the nervous system controls organ function was originally applied to the cardiovascular, gastrointestinal, musculoskeletal, and other body systems. Development of advanced neurophysiological and immunological techniques recently enabled the study of reflex neural circuits that maintain immunological homeostasis, and are essential for health in mammals. Such reflexes are evolutionarily ancient, dating back to invertebrate nematode worms that possess primitive immune and nervous systems. Failure of these reflex mechanisms in mammals contributes to nonresolving inflammation and disease. It is also possible to target these neural pathways using electrical nerve stimulators and pharmacological agents to hasten the resolution of inflammation and provide therapeutic benefit.

The probiotic Bacillus licheniformis ameliorates heat stress-induced impairment of egg production, gut morphology, and intestinal mucosal immunity in laying hens

We investigated the effect of a 12-d exposure to 34°C plus dietary inclusion of the probiotic Bacillus licheniformis on the egg production, gut morphology, and intestinal mucosal immunity of laying hens. Ninety-six commercial hens (Hy-Line Brown) at the age of 60 wk were randomly allocated to 4 groups. After a period of laying rate adjustment (14 d), all the hens were subjected to 2 temperature treatments (12 d). Birds in 1 group were raised at 21°C and fed a basal diet, and birds in the other 3 groups were raised at 34°C and fed a basal diet supplemented with 0, 10(6), or 10(7) cfu of B. licheniformis per gram of feed, respectively. Rearing at 34°C depressed egg production and feed intake (P < 0.05). Compared with birds kept at 21°C, birds kept at 34°C had elevated serum levels of tumor necrosis factor-α (d 6), IL-1 (d 6 and 12), and corticosterone (d 6); decreased villus height (ileum: d 6; cecum: d 6 and 12) and ratio of villus height to crypt depth (ileum: d 6; cecum: d 6 and 12); fewer intraepithelial lymphocytes (ileum: d 6; cecum: d 6) and IgA-secreting cells (ileum: d 6; cecum: d 6 and 12); and more mast cells (ileum: d 6; cecum: d 6 and 12; P < 0.05). The number of goblet cells in the cecum increased at d 6 in heat-treated birds, and then deceased at d 12 (P < 0.05). Moreover, morphological examination showed injury to the villi of birds kept at 34°C. In general, inclusion of 10(7) cfu/g of B. licheniformis in the diet of heat-stressed hens was effective in overcoming the observed decline in egg production and feed intake, restoring the impaired villus structure, and sustaining a balanced mucosal immune response. Therefore, the probiotic B. licheniformis may be useful for ameliorating the adverse influence of heat on the egg production and gut health of laying hens.

The calm mouse: an animal model of stress reduction

Chronic stress is associated with negative health outcomes and is linked with neuroendocrine changes, deleterious effects on innate and adaptive immunity, and central nervous system neuropathology. Although stress management is commonly advocated clinically, there is insufficient mechanistic understanding of how decreasing stress affects disease pathogenesis. Therefore, we have developed a "calm mouse model" with caging enhancements designed to reduce murine stress. Male BALB/c mice were divided into four groups: control (Cntl), standard caging; calm (Calm), large caging to reduce animal density, a cardboard nest box for shelter, paper nesting material to promote innate nesting behavior, and a polycarbonate tube to mimic tunneling; control exercise (Cntl Ex), standard caging with a running wheel, known to reduce stress; and calm exercise (Calm Ex), calm caging with a running wheel. Calm, Cntl Ex and Calm Ex animals exhibited significantly less corticosterone production than Cntl animals. We also observed changes in spleen mass, and in vitro splenocyte studies demonstrated that Calm Ex animals had innate and adaptive immune responses that were more sensitive to acute handling stress than those in Cntl. Calm animals gained greater body mass than Cntl, although they had similar food intake, and we also observed changes in body composition, using magnetic resonance imaging. Together, our results suggest that the Calm mouse model represents a promising approach to studying the biological effects of stress reduction in the context of health and in conjunction with existing disease models.

Exploring the effects of pain and stress on wound healing

Wound-related pain is complex, involving a multitude of physiological and psychological factors, such as emotional state, culture, personality, meanings, and expectations. The impact of pain on the individual can contribute to stress and compromise quality of life. The purpose of this article is to review the relationships among pain, stress, and wound healing.

Innate immune properties of selected human neuropeptides against Moraxella catarrhalis and nontypeable Haemophilus influenzae

Background

Considerable evidence supports the concept of active communication between the nervous and immune systems. One class of such communicators are the neuropeptides (NPs). Recent reports have highlighted the antimicrobial activity of neuropeptides, placing them among the integral components of innate immune defense. This study examined the action of four human neuropeptides: calcitonin gene-related peptide (CGRP), neuropeptide Y (NPY), substance P (SP) and somatostatin (SOM), which are accessible in the upper respiratory tract, against two human-specific respiratory pathogens. We studied: (i) neuropeptide-mediated direct antibacterial activity exerted against Moraxella catarrhalis and nontypeable Haemophilus influenzae, and (ii) indirect immunomodulatory role of these neuropeptides in the neutrophil-mediated phagocytosis of indicated pathogens.

Results

We found that 100 micromolar concentrations of CGRP, NPY, SP, and SOM effectively permeabilized bacterial membranes and showed (except SOM) bactericidal activity against both pathogens. SOM acted only bacteriostatically. However the killing efficacy was dependent on the bactericidal assay used. The rank order of killing NP effect was: NPY ≥ CGRP > SP >> SOM and correlated with their potency to permeabilize bacterial membranes. The killing and permeabilization activity of the analyzed NPs showed significant correlation with several physicochemical properties and amino acid composition of the neuropeptides. M. catarrhalis was more sensitive to neuropeptides than nontypeable H. influenzae.

The immunomodulatory bimodal effect of physiological concentrations of CGRP, NPY, and SP on the phagocytic function of human neutrophils against M. catarrhalis and H. influenzae was observed both in the ingestion (pathogen uptake) and reactive oxygen species generation stages. This effect was also dependent on the distinct type of pathogen recognition (opsonic versus nonopsonic).

Conclusions

The present results indicate that neuropeptides such as CGRP, NPY, and SP can effectively participate in the direct and indirect elimination of human-specific respiratory pathogens. Because the studied NPs show both direct and indirect modulating antimicrobial potency, they seem to be important molecules involved in the innate host defense against M. catarrhalis and nontypeable H. influenzae.

Immune system in the brain: a modulatory role on dendritic spine morphophysiology?

The central nervous system is closely linked to the immune system at several levels. The brain parenchyma is separated from the periphery by the blood brain barrier, which under normal conditions prevents the entry of mediators such as activated leukocytes, antibodies, complement factors, and cytokines. The myeloid cell lineage plays a crucial role in the development of immune responses at the central level, and it comprises two main subtypes: (1) resident microglia, distributed throughout the brain parenchyma; (2) perivascular macrophages located in the brain capillaries of the basal lamina and the choroid plexus. In addition, astrocytes, oligodendrocytes, endothelial cells, and, to a lesser extent, neurons are implicated in the immune response in the central nervous system. By modulating synaptogenesis, microglia are most specifically involved in restoring neuronal connectivity following injury. These cells release immune mediators, such as cytokines, that modulate synaptic transmission and that alter the morphology of dendritic spines during the inflammatory process following injury. Thus, the expression and release of immune mediators in the brain parenchyma are closely linked to plastic morphophysiological changes in neuronal dendritic spines. Based on these observations, it has been proposed that these immune mediators are also implicated in learning and memory processes.

Decidual macrophages and their roles at the maternal-fetal interface

The semi-allogeneic fetus, whose genome consists of maternally and paternally inherited alleles, must coexist with an active maternal immune system during its 9 months in utero. Macrophages are the second most abundant immune cell at the maternal-fetal interface, although populations and functions for these populations remain ill defined. We have previously reported two distinct subsets of CD14(+) decidual macrophages found to be present in first trimester decidual tissue, 20 percent CD11c(HI) and 68 percent CD11c(LO). Interestingly, CD11c(HI) decidual macrophages express genes associated with lipid metabolism, inflammation, and antigen presentation function and specifically upregulate CD1 molecules. Conversely, CD11c(LO) decidual macrophages express genes associated with extracellular matrix formation, muscle regulation, and tissue growth. The large abundance of CD11c(HI) decidual macrophages and their ability to process antigens more efficiently than CD11c(LO) macrophages suggests that CD11c(HI) macrophages may be important antigen processing and presenting cells at the maternal-fetal interface, while CD11c(LO) macrophages may perform necessary homeostatic functions during placental construction. Thus, macrophage heterogeneity may be an important and necessary division of labor that leads to both an induction of maternal immune cell tolerance to fetal antigens as well as basic homeostatic functions in human pregnancy.

Insect neuropeptide bursicon homodimers induce innate immune and stress genes during molting by activating the NF-κB transcription factor Relish

Background

Bursicon is a heterodimer neuropeptide composed of two cystine knot proteins, bursicon α (burs α) and bursicon β (burs β), that elicits cuticle tanning (melanization and sclerotization) through the Drosophila leucine-rich repeats-containing G protein-coupled receptor 2 (DLGR2). Recent studies show that both bursicon subunits also form homodimers. However, biological functions of the homodimers have remained unknown until now.

Methodology/Principal Findings

In this report, we show in Drosophila melanogaster that both bursicon homodimers induced expression of genes encoding antimicrobial peptides (AMPs) in neck-ligated adults following recombinant homodimer injection and in larvae fat body after incubation with recombinant homodimers. These AMP genes were also up-regulated in 24 h old unligated flies (when the endogenous bursicon level is low) after injection of recombinant homodimers. Up-regulation of AMP genes by the homodimers was accompanied by reduced bacterial populations in fly assay preparations. The induction of AMP expression is via activation of the NF-κB transcription factor Relish in the immune deficiency (Imd) pathway. The influence of bursicon homodimers on immune function does not appear to act through the heterodimer receptor DLGR2, i.e. novel receptors exist for the homodimers.

Conclusions/Significance

Our results reveal a mechanism of CNS-regulated prophylactic innate immunity during molting via induced expression of genes encoding AMPs and genes of the Turandot family. Turandot genes are also up-regulated by a broader range of extreme insults. From these data we infer that CNS-generated bursicon homodimers mediate innate prophylactic immunity to both stress and infection during the vulnerable molting cycle.

Disruption of proprotein convertase 1/3 (PC1/3) expression in mice causes innate immune defects and uncontrolled cytokine secretion

The proprotein convertase 1/3 is expressed in the regulated secretory pathway of neural and endocrine cells. Its major function is in the post-translational processing and activation of precursor proteins. The PC1/3 knock-out (KO) mouse model has allowed us to elucidate its physiological functions in studies focused primarily on neuroendocrine tissues. However, PC1/3 is also expressed in cells of the immune system, mainly in macrophages. The present study explores the effects of innate immune challenge in the PC1/3 KO mouse. PC1/3 KO mice have an enlarged spleen with marked disorganization of the marginal zone and red pulp. Immunohistochemical studies using various markers demonstrate a depletion of dendritic cells in PC1/3 KO spleens. When challenged with lipopolysaccharide, PC1/3 KO mice are more susceptible to septic shock than wild-type controls or other PC KO mice, such as PC2 and PC7 null mice. Plasma levels of proinflammatory cytokines (IL-6, IL-1β, and TNF-α) were very significantly elevated in PC1/3 KO mice, consistent with a hypercytokinemia, i.e. indicative of a major systemic uncontrolled inflammatory response or cytokine storm. Peritoneal macrophages isolated from PC1/3 KO mice also demonstrate elevated cytokine secretion when treated with LPS. Electron micrographs show morphological features indicating a prolonged activation of these cells following LPS stimulation. We also present evidence that the proinflammatory T(h)1 pathway is dominant in the PC1/3 KO mouse model. We conclude that aside from its important role in neuroendocrine functions PC1/3 also has an important role in the regulation of the innate immune system, most likely through the regulation of cytokine secretion in macrophages.

Acute and chronic stress induced changes in sensitivity of peripheral inflammatory pathways to the signals of multiple stress systems --2011 Curt Richter Award Winner

Exposure to psychosocial stress has been associated with increasing rates of morbidity in humans and in animal models, but the underlying mechanisms are not completely understood. Major stress responsive systems, such as the hypothalamus-pituitary adrenal (HPA) axis and the autonomic nervous system (ANS) are under investigation as underlying pathways, but although acute stress reliably activates these systems, findings of long-term alternations in baseline activity are inconsistent at present. Emerging evidence suggests that stress-related changes in the sensitivity of target systems toward glucocorticoid (GC) regulation, i.e. development of GC resistance, might help explain inflammatory disinhibition and development of disease related to inflammation. More recent findings further show that the autonomic nervous system might play an important role in the regulatory control of the inflammatory cascade. The major argument put forward in this manuscript is that target tissues for stress system modulation, such as the inflammatory cascade, vary in their ability to respond to stress system signaling, and that assessing alterations in this stress signal sensitivity which can be caused by stress or disease processes, might be necessary to understand and explain stress effects on health. This review focuses on the inflammatory system in particular, because anti-inflammatory effects of most stress systems have been documented, but the general assumption might have to be generalized to other target systems. The main conclusion to be made is that reduction in glucocorticoid sensitivity of target tissues is the most consistent finding at present, and that assessing such changes in glucocorticoid sensitivity might be necessary to understand many stress-related changes in physiology.

Behavioral and immune responses to infection require Gαq- RhoA signaling in C. elegans

Following pathogen infection the hosts' nervous and immune systems react with coordinated responses to the danger. A key question is how the neuronal and immune responses to pathogens are coordinated, are there common signaling pathways used by both responses? Using C. elegans we show that infection by pathogenic strains of M. nematophilum, but not exposure to avirulent strains, triggers behavioral and immune responses both of which require a conserved Gαq-RhoGEF Trio-Rho signaling pathway. Upon infection signaling by the Gαq pathway within cholinergic motorneurons is necessary and sufficient to increase release of the neurotransmitter acetylcholine and increase locomotion rates and these behavioral changes result in C. elegans leaving lawns of M. nematophilum. In the immune response to infection signaling by the Gαq pathway within rectal epithelial cells is necessary and sufficient to cause changes in cell morphology resulting in tail swelling that limits the infection. These Gαq mediated behavioral and immune responses to infection are separate, act in a cell autonomous fashion and activation of this pathway in the appropriate cells can trigger these responses in the absence of infection. Within the rectal epithelium the Gαq signaling pathway cooperates with a Ras signaling pathway to activate a Raf-ERK-MAPK pathway to trigger the cell morphology changes, whereas in motorneurons Gαq signaling triggers behavioral responses independent of Ras signaling. Thus, a conserved Gαq pathway cooperates with cell specific factors in the nervous and immune systems to produce appropriate responses to pathogen. Thus, our data suggests that ligands for Gq coupled receptors are likely to be part of the signals generated in response to M. nematophilum infection.

Once infected by a pathogen the nervous and immune systems of many animals react with coordinated responses to the danger. A key question is what are the pathways by which responses to infection occur and to what extent are the same pathways involved in differing responses? Here we demonstrate that a Gαq-RhoA pathway is required for both behavioral and immune responses to infection in C. elegans. We show that Gαq-RhoA signaling is a late step in the response to infection and their site of action defines the cellular targets of signals generated internally in response to infection. One response is to move away from sites of pathogenic bacteria and Gαq-RhoA signaling acts in motorneurons to achieve this. A second response is an innate immune response where Gαq-RhoA signaling acts within cells close to sites of infection, the rectal epithelial cells, to cause major changes in their size and shape to mitigate the effects of infection. Our work demonstrates that ligands for Gq coupled GPCRs are likely to be required for response to infection. Identifying these ligands and the cells that release them will help define the mechanisms by which C. elegans recognizes pathogens and coordinates behavioral and immune responses to infection.

Post-traumatic anxiety associates with failure of the innate immune receptor TLR9 to evade the pro-inflammatory NFκB pathway

Post-traumatic anxiety notably involves inflammation, but its causes and functional significance are yet unclear. Here, we report that failure of the innate immune system Toll-like receptor 9 (TLR9) to limit inflammation is causally involved with anxiety-associated inflammation and that peripheral administration of specific oligonucleotide activators of TLR9 may prevent post-traumatic consequences in stressed mice. Suggesting involvement of NFκB-mediated enhancement of inflammatory reactions in the post-traumatic phenotype, we found association of serum interleukin-1β increases with symptoms severity and volumetric brain changes in post-traumatic stress disorder patients. In predator scent-stressed mice, the moderate NFκB-activating oligonucleotides mEN101 and its human ortholog BL-7040, but not the canonic NFκB activator oligonucleotide ODN1826, induced anxiolytic effects. In stressed mice, peripherally administered mEN101 prevented delayed stress-inducible serum interleukin-1β increases while limiting stress-characteristic hippocampal transcript modifications and the anxiety-induced EGR1-mediated neuronal activation. Attesting to the TLR9 specificity of this response, BL-7040 suppressed NFκB-mediated luciferase in transfected cells co-expressing TLR9, but not other TLRs. Furthermore, TLR9-/- mice were mEN101 and BL-7040 resistant and presented unprovoked anxiety-like behavior and anxiety-characteristic hippocampal transcripts. Our findings demonstrate functional relevance of TLR9 in protecting stressed mammals from overreacting to traumatic experiences and suggest using oligonucleotide-mediated peripheral TLR9 activation to potentiate the innate immune system and prevent post-traumatic inflammation and anxiety.

Caregiving burden, stress, and health effects among family caregivers of adult cancer patients

Unlike professional caregivers such as physicians and nurses, informal caregivers, typically family members or friends, provide care to individuals with a variety of conditions including advanced age, dementia, and cancer. This experience is commonly perceived as a chronic stressor, and caregivers often experience negative psychological, behavioral, and physiological effects on their daily lives and health. In this report, we describe the experience of a 53-year-old woman who is the sole caregiver for her husband, who has acute myelogenous leukemia and was undergoing allogeneic hematopoietic stem cell transplantation. During his intense and unpredictable course, the caregiver's burden is complex and complicated by multiple competing priorities. Because caregivers are often faced with multiple concurrent stressful events and extended, unrelenting stress, they may experience negative health effects, mediated in part by immune and autonomic dysregulation. Physicians and their interdisciplinary teams are presented daily with individuals providing such care and have opportunity to intervene. This report describes a case that exemplifies caregiving burden and discusses the importance of identifying caregivers at risk of negative health outcomes and intervening to attenuate the stress associated with the caregiving experience.

Stress and the anti-influenza immune response: repeated social defeat augments clonal expansion of CD8(+)T cells during primary influenza A viral infection

Social disruption stress (SDR) prior to primary influenza A virus (IAV) infection augments memory to IAV re-challenge in a T cell-specific manner. However, the effect of SDR on the primary anti-viral immune response has not been elucidated. In this study, SDR-infected (INF) mice terminated viral gene expression earlier and mounted an enhanced pulmonary IAV-specific CD8(+)T cell response versus controls. Additionally, SDR-INF mice had a more pro-inflammatory lung profile prior to and during infection and an attenuated corticosterone response. These data demonstrate neuroendocrine modification of the lung microenvironment and increased antigen-specific T cell activation, clonal expansion and viral control in stress-exposed mice.

Dysfunctional nucleus tractus solitarius: its crucial role in promoting neuropathogenetic cascade of Alzheimer's dementia--a novel hypothesis

The pathophysiological mechanism(s) underlying Alzheimer's disease (AD) still remain unclear, and no disease-modifying or prophylactic therapies are currently available. Unraveling the fundamental neuropathogenesis of AD is an important challenge. Several studies on AD have suggested lesions in a number of CNS areas including the basal forebrain, hippocampus, entorhinal cortex, amygdale/insula, and the locus coeruleus. However, plausible unifying studies on the upstream factors that involve these heterogeneous regions and herald the onset of AD pathogenesis are not available. The current article presents a novel nucleus tractus solitarius (NTS) vector hypothesis that underpins several disparate biological mechanisms and neural circuits, and identifies relevant hallmarks of major presumptive causative factor(s) linked to the NTS, in older/aging individuals. Aging, obesity, infection, sleep apnea, smoking, neuropsychological states, and hypothermia-all activate inflammatory cytokines and oxidative stress. The synergistic impact of systemic proinflammatory mediators activates microglia and promotes neuroinflammation. Acutely, the innate immune response is protective defending against pathogens/toxins; however, when chronic, it causes neuroinflammation and neuronal dysfunction, particularly in brainstem and neocortex. The NTS in the brainstem is an essential multiple signaling hub, and an extremely important central integration site of baroreceptor, chemoreceptor, and a multitude of sensory afferents from gustatory, gastrointestinal, cardiac, pulmonary, and upper airway systems. Owing to persistent neuroinflammation, the dysfunctional NTS exerts deleterious impact on nucleus ambiguus, dorsal motor nucleus of vagus, hypoglossal, parabrachial, locus coeruleus and many key nuclei in the brainstem, and the hippocampus, entorhinal cortex, prefrontal cortex, amygdala, insula, and basal forebrain in the neocortex. The neuronal and synaptic dysfunction emanating from the inflamed NTS may affect its interconnected pathways impacting almost the entire CNS--which is already primed by neuroinflammation, thus promoting cognitive and neuropsychiatric symptoms. The upstream factors discussed here may underpin the neuropathopgenesis of AD. AD pathology is multifactorial; the current perspective underscores the value of attenuating disparate upstream factors--in conjunction with anticholinesterase, anti-inflammatory, immunosuppressive, and anti-oxidant pharmacotherapy. Amelioration of the NTS pathology may be of central importance in countering the neuropathological cascade of AD. The NTS, therefore, may be a potential target of novel therapeutic strategies.

Chronic cold stress in mice induces a regulatory phenotype in macrophages: correlation with increased 11β-hydroxysteroid dehydrogenase expression

Susceptibility to infections, autoimmune disorders and tumor progression is strongly influenced by the activity of the endocrine and nervous systems in response to a stressful stimulus. When the adaptive system is switched on and off efficiently, the body is able to recover from the stress imposed. However, when the system is activated repeatedly or the activity is sustained, as during chronic or excessive stress, an allostatic load is generated, which can lead to disease over long periods of time. We investigated the effects of chronic cold stress in BALB/c mice (4°C/4 h daily for 7 days) on functions of macrophages. We found that chronic cold stress induced a regulatory phenotype in macrophages, characterized by diminished phagocytic ability, decreased TNF-α and IL-6 and increased IL-10 production. In addition, resting macrophages from mice exposed to cold stress stimulated spleen cells to produce regulatory cytokines, and an immunosuppressive state that impaired stressed mice to control Trypanosoma cruzi proliferation. These regulatory effects correlated with an increase in macrophage expression of 11β-hydroxysteroid dehydrogenase, an enzyme that converts inactive glucocorticoid into its active form. As stress is a common aspect of modern life and plays a role in the etiology of many diseases, the results of this study are important for improving knowledge regarding the neuro-immune-endocrine interactions that occur during stress and to highlight the role of macrophages in the immunosuppression induced by chronic stress.