Leptin fails to blunt the lipopolysaccharide-induced activation of the hypothalamic-pituitary-adrenal axis in rats

Copyright @ 2013 The authors. This work is licensed under a Creative Commons Attribution 3.0 Unported License.Obesity is a risk factor for sepsis morbidity and mortality, whereas the hypothalamic-pituitary-adrenal (HPA) axis plays a protective role in the body's defence against sepsis. Sepsis induces a profound systemic immune response and cytokines serve as excellent markers for sepsis as they act as mediators of the immune response. Evidence suggests that the adipokine leptin may play a pathogenic role in sepsis. Mouse endotoxaemic models present with elevated leptin levels and exogenously added leptin increased mortality whereas human septic patients have elevated circulating levels of the soluble leptin receptor (Ob-Re). Evidence suggests that leptin can inhibit the regulation of the HPA axis. Thus, leptin may suppress the HPA axis, impairing its protective role in sepsis.We hypothesised that leptin would attenuate the HPA axis response to sepsis.We investigated the direct effects of an i.p. injection of 2 mg/kg leptin on the HPA axis response to intraperitoneally injected 25 μg/kg lipopolysaccharide (LPS) in the male Wistar rat. We found that LPS potently activated the HPA axis, as shown by significantly increased plasma stress hormones, ACTH and corticosterone, and increased plasma interleukin 1β (IL1β) levels, 2 h after administration. Pre-treatment with leptin, 2 h before LPS administration, did not influence the HPA axis response to LPS. In turn, LPS did not affect plasma leptin levels. Our findings suggest that leptin does not influence HPA function or IL1b secretion in a rat model of LPS-induced sepsis, and thus that leptin is unlikely to be involved in the acute-phase endocrine response to bacterial infection in rats.The section is funded by grants from the MRC, BBSRC, NIHR and an Integrative Mammalian Biology (IMB) Capacity Building Award, and by a FP7-HEALTH-2009-241592 EuroCHIP grant and is supported by the NIHR Imperial Biomedical Research Centre Funding Scheme. This work is supported by a BBSRC Doctoral Training-Strategic Skills Award grant (BB/F017340/1)

Bidirectional Psychoneuroimmune Interactions in the Early Postpartum Period Influence Risk of Postpartum Depression

More than 500,000 U.S. women develop postpartum depression (PPD) annually. Although psychosocial risks are known, the underlying biology remains unclear. Dysregulation of the immune inflammatory response and the hypothalamic–pituitary–adrenal (HPA) axis are associated with depression in other populations. While significant research on the contribution of these systems to the development of PPD has been conducted, results have been inconclusive. This is partly because few studies have focused on whether disruption in the bidirectional and dynamic interaction between the inflammatory response and the HPA axis together influence PPD. In this study, we tested the hypothesis that disruption in the inflammatory-HPA axis bidirectional relationship would increase the risk of PPD. Plasma pro- and anti-inflammatory cytokines were measured in women during the 3rd trimester of pregnancy and on Days 7 and 14, and Months 1, 2, 3, and 6 after childbirth. Saliva was collected 5 times the day preceding blood draws for determination of cortisol area under the curve (AUC) and depressive symptoms were measured using the Edinburgh Postpartum Depression Survey (EPDS). Of the 152 women who completed the EPDS, 18% were depressed according to EDPS criteria within the 6 months postpartum. Cortisol AUC was higher in symptomatic women on Day 14 (p = .017). To consider the combined effects of cytokines and cortisol on predicting symptoms of PPD, a multiple logistic regression model was developed that included predictors identified in bivariate analyses to have an effect on depressive symptoms. Results indicated that family history of depression, day 14 cortisol AUC, and the day 14 IL8/IL10 ratio were significant predictors of PPD symptoms. One unit increase each in the IL8/IL10 ratio and cortisol AUC resulted in 1.50 (p = 0.06) and 2.16 (p = 0.02) fold increases respectively in the development of PPD. Overall, this model correctly classified 84.2% of individuals in their respective groups. Findings suggest that variability in the complex interaction between the inflammatory response and the HPA axis influence the risk of PPD

Stress induced polarization of immune-neuroendocrine phenotypes in Gallus gallus

Immune-neuroendocrine phenotypes (INPs) stand for population subgroups differing in immune-neuroendocrine interactions. While mammalian INPs have been characterized thoroughly in rats and humans, avian INPs were only recently described in Coturnix coturnix (quail). To assess the scope of this biological phenomenon, herein we characterized INPs in Gallus gallus (a domestic hen strain submitted to a very long history of strong selective breeding pressure) and evaluated whether a social chronic stress challenge modulates the individuals’ interplay affecting the INP subsets and distribution. Evaluating plasmatic basal corticosterone, interferon-γ and interleukin-4 concentrations, innate/acquired leukocyte ratio, PHA-P skin-swelling and induced antibody responses, two opposite INP profiles were found: LEWIS-like (15% of the population) and FISCHER-like (16%) hens. After chronic stress, an increment of about 12% in each polarized INP frequency was found at expenses of a reduction in the number of birds with intermediate responses. Results show that polarized INPs are also a phenomenon occurring in hens. The observed inter-individual variation suggest that, even after a considerable selection process, the population is still well prepared to deal with a variety of immune-neuroendocrine challenges. Stress promoted disruptive effects, leading to a more balanced INPs distribution, which represents a new substrate for challenging situations.Fil: Nazar, Franco Nicolas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Investigaciones Biológicas y Tecnológicas; ArgentinaFil: Estevez, Inma. Centro de Investigación. Neiker - Tecnalia; EspañaFil: Correa, Silvia Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Marin, Raul Hector. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Investigaciones Biológicas y Tecnológicas; Argentin

Role of prethymic cells in acquisition of self-tolerance

The sequential character of T-lymphocyte development as it pertains to the stage at which self-tolerance is acquired was investigated. Three phases were studied, defined here as prethymic, intrathymic, and postthymic as determined by the timing of thymus implantation. The model utilized was the temporal pattern of skin graft rejection in thymusless BALB/c nude mice implanted with allogeneic, C57BL/6J, or syngeneic thymuses before or after skin grafting; in some instances, F(1) hybrid spleen cells were also given to newborns or young adults. These experiments in nude mice showed that, (a) self-tolerance could be established despite the absence of the host’s own haplotype in the implanted thymus; (b) recently emigrated postthymic cells could already discriminate self from non-self; (c) specific neonatal tolerance could be induced in nudes by inoculation of F(1) hybrid cells; (d) nudes showed a higher capacity for induction of neonatal tolerance than did normal littermates. These findings indicate that the process of self-tolerance in the T cell's lineage begins during the prethymic state early in ontogeny

Die Wirtschaft als Thema der Soziologie: zur Entwicklung wirtschaftssoziologischer Forschung in Deutschland und den USA

"Was ist Wirtschaftssoziologie? Die Frage nach Identität dieser soziologischen Teildisziplin ist immer wieder Gegenstand konzeptioneller Ausführungen. In diesem Artikel wählen wir einen anderen Ansatz, indem wir die Beschäftigung der Soziologie mit dem Thema Wirtschaft empirisch untersuchen. Dafür wurde eine Inhaltsanalyse von insgesamt sechs führenden US-amerikanischen und deutschen Soziologiezeitschriften für einen Publikationszeitraum von 1974 bis 2005 durchgeführt. Die Auswertungen zeigen eine wachsende Bedeutung ökonomischer Themen innerhalb der Soziologie seit den Siebzigerjahren, eine Entwicklung, die in Deutschland etwa zehn Jahre später einsetzt als in den USA. Als Themenfelder während der letzten dreißig Jahre sind insbesondere Arbeit und Unternehmen sowie zunehmend das Thema Märkte bedeutsam. Theoretische Schwerpunkte bei der Analyse ökonomischer Phänomene sind vor allem neoinstitutionalistische Theorien und der Netzwerkansatz. Insgesamt lässt sich eine relativ große Vielfalt wirtschaftssoziologischer Forschung erkennen. Diese Pluralität wird von uns als Vorzug der Wirtschaftssoziologie gegenüber dem vergleichsweise engen Blickwinkel der Wirtschaftswissenschaften gewertet." (Autorenreferat)"What is economic sociology? The question of the identity of this sociological field of inquiry has been the subject of numerous theoretical contributions. In this paper we take a different approach by investigating the field of economic sociology empirically. Using a content analysis of six leading German and American sociology journals since the 1970s, we analyze how sociology has dealt with economic phenomena during the last 30 years. The results provide evidence of the growing importance of economic sociology in American and German sociology since the 1970s. In German sociology this development set in about ten years later than in the United States. 'Labor' and 'firms' were among the most important subjects examined from the sociological perspective on the economy over the last 30 years; the relevance of markets is steadily rising. Sociologists draw mainly on neo-institutionalist and network theories to analyze economic phenomena. Our evidence shows that economic sociology is a plural field encompassing a wide variety of approaches, which we see as an advantage over the relatively narrow scope of mainstream economics." (author's abstract

Die Wirtschaft als Thema der Soziologie: Zur Entwicklung wirtschaftssoziologischer Forschung in Deutschland und den USA

"Was ist Wirtschaftssoziologie? Die Frage nach Identität dieser soziologischen Teildisziplin ist immer wieder Gegenstand konzeptioneller Ausführungen. In diesem Artikel wählen wir einen anderen Ansatz, indem wir die Beschäftigung der Soziologie mit dem Thema Wirtschaft empirisch untersuchen. Dafür wurde eine Inhaltsanalyse von insgesamt sechs führenden US-amerikanischen und deutschen Soziologiezeitschriften für einen Publikationszeitraum von 1974 bis 2005 durchgeführt. Die Auswertungen zeigen eine wachsende Bedeutung ökonomischer Themen innerhalb der Soziologie seit den 1970er Jahren, eine Entwicklung, die in Deutschland etwa zehn Jahre später einsetzt als in den USA. Als Themenfelder während der letzten dreißig Jahre sind insbesondere Arbeit und Unternehmen sowie zunehmend das Thema Märkte bedeutsam. Theoretische Schwerpunkte bei der Analyse ökonomischer Phänomene sind vor allem neo-institutionalistische Theorien und der Netzwerkansatz. Insgesamt lässt sich eine relativ große Vielfalt wirtschaftssoziologischer Forschung erkennen. Diese Pluralität wird von uns als Vorzug der Wirtschaftssoziologie gegenüber dem vergleichsweise engen Blickwinkel der Wirtschaftswissenschaften gewertet.

Hypnotic enhancement of slow-wave sleep increases sleep-associated hormone secretion and reduces sympathetic predominance in healthy humans

Sleep is important for normal brain and body functioning, and for this, slow-wave sleep (SWS), the deepest stage of sleep, is assumed to be especially relevant. Previous studies employing methods to enhance SWS have focused on central nervous components of this sleep stage. However, SWS is also characterized by specific changes in the body periphery, which are essential mediators of the health-benefitting effects of sleep. Here we show that enhancing SWS in healthy humans using hypnotic suggestions profoundly affects the two major systems linking the brain with peripheral body functions, i.e., the endocrine and the autonomic nervous systems (ANS). Specifically, hypnotic suggestions presented at the beginning of a 90-min afternoon nap to promote subsequent SWS strongly increased the release of growth hormone (GH) and, to a lesser extent, of prolactin and aldosterone, and shifted the sympathovagal balance towards reduced sympathetic predominance. Thus, the hypnotic suggestions induced a whole-body pattern characteristic of natural SWS. Given that the affected parameters regulate fundamental physiological functions like metabolism, cardiovascular activity, and immunity, our findings open up a wide range of potential applications of hypnotic SWS enhancement, in addition to advancing our knowledge on the physiology of human SWS

Resolution of inflammation: what Controls its Onset?

The authors would like to acknowledge the funding agencies, Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq, Brazil), Comissão de Aperfeiçoamento de Pessoal do Ensino Superior (CAPES, Brazil), Fundação do Amparo a Pesquisa de Minas Gerais (FAPEMIG, Brazil), Instituto Nacional de Ciência e Tecnologia (INCT in Dengue), and the European Community’s Seventh Framework Programme (FP7-2007-2013, Timer consortium) under grant agreement HEALTH-F4-2011-281608. MP acknowledges funding from the Wellcome Trust (program 086867/Z/08), the Medical Research Council UK (MR/K013068/1), and the William Harvey Research Foundation

A narrative review on the similarities and dissimilarities between myalgic encephalomyelitis/chronic fatigue syndrome (me/cfs) and sickness behavior

It is of importance whether myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a variant of sickness behavior. The latter is induced by acute infections/injury being principally mediated through proinflammatory cytokines. Sickness is a beneficial behavioral response that serves to enhance recovery, conserves energy and plays a role in the resolution of inflammation. There are behavioral/symptomatic similarities (for example, fatigue, malaise, hyperalgesia) and dissimilarities (gastrointestinal symptoms, anorexia and weight loss) between sickness and ME/CFS. While sickness is an adaptive response induced by proinflammatory cytokines, ME/CFS is a chronic, disabling disorder, where the pathophysiology is related to activation of immunoinflammatory and oxidative pathways and autoimmune responses. While sickness behavior is a state of energy conservation, which plays a role in combating pathogens, ME/CFS is a chronic disease underpinned by a state of energy depletion. While sickness is an acute response to infection/injury, the trigger factors in ME/CFS are less well defined and encompass acute and chronic infections, as well as inflammatory or autoimmune diseases. It is concluded that sickness behavior and ME/CFS are two different conditions