Cytokines in the neuroendocrine system

Transcriptome analysis of oviduct in laying ducks under different stocking densities

1. High stocking densities can lead to animal stress responses and lead to changes in bird behaviour, egg production and the fertility of laying birds. The oviduct plays a crucial role during the process of laying eggs. Therefore, it is essential to know how high stocking density affects oviduct function.2. In this study, a total of 2,115 differentially expressed genes (DEGs) were identified in duck oviduct tissues between different stocking density groups. These genes are mainly enriched in membrane components, calcium ion binding, cytokine-cytokine receptor interaction and focal adhesion. These pathways were closely related to the formation of eggs. This indicated that secretion and material transport functions of the oviduct are affected under high-density stocking. Further analysis showed that a total of 408 genes related to the transportation process were expressed in the oviduct, of which 96 genes were differentially expressed (LogFC≥1, P < 0.05). Forty-two of these DEGs belonged to the solute carrier family. The data showed that the expression of 31 transcripts was different between the two density groups. Expression of KCNJ15, SLC26A8, and TRPM5 was only seen in the high-density group (8/m²), while ATP13A3 and KCNIP2 were only expressed in the low-density group (4/m²).3. Consequently, high stocking density may affect the expression and splicing of genes related to molecular transport in the oviduct.

RNA-Seq reveals seven promising candidate genes affecting the proportion of thick egg albumen in layer-type chickens

Eggs with a much higher proportion of thick albumen are preferred in the layer industry, as they are favoured by consumers. However, the genetic factors affecting the thick egg albumen trait have not been elucidated. Using RNA sequencing, we explored the magnum transcriptome in 9 Rhode Island white layers: four layers with phenotypes of extremely high ratios of thick to thin albumen (high thick albumen, HTA) and five with extremely low ratios (low thick albumen, LTA). A total of 220 genes were differentially expressed, among which 150 genes were up-regulated and 70 were down-regulated in the HTA group compared with the LTA group. Gene Ontology (GO) analysis revealed that the up-regulated genes in HTA were mainly involved in a wide range of regulatory functions. In addition, a large number of these genes were related to glycosphingolipid biosynthesis, focal adhesion, ECM-receptor interactions and cytokine-cytokine receptor interactions. Based on functional analysis, ST3GAL4, FUT4, ITGA2, SDC3, PRLR, CDH4 and GALNT9 were identified as promising candidate genes for thick albumen synthesis and metabolism during egg formation. These results provide new insights into the molecular mechanisms of egg albumen traits and may contribute to future breeding strategies that optimise the proportion of thick egg albumen.

Oxytocin alleviates the neuroendocrine and cytokine response to bacterial endotoxin in healthy men

Oxytocin is a hormone and neurotransmitter found to have anti-inflammatory functions in rodents. Here we used experimental bacterial endotoxinemia to examine the role of exogenous oxytocin administration on innate immune responses in humans. Ten healthy men received, in a randomized, placebo-controlled, crossover design, placebo, oxytocin, LPS, and LPS + oxytocin. Oxytocin treatment resulted in a transient or prolonged reduction of endotoxin-induced increases in plasma ACTH, cortisol, procalcitonin, TNF-alpha, IL-1 receptor antagonist, IL-4, IL-6, macrophage inflammatory protein-1alpha, macrophage inflammatory protein-1beta, monocyte chemoattractant protein-1 (MCP-1), interferon-inducible protein 10, and VEGF. In vitro, oxytocin had no impact on LPS effects in releasing TNF-alpha, IL-6, and MCP-1 in monocytes and peripheral blood mononuclear cells from healthy human donors. In summary, oxytocin decreases the neuroendocrine and cytokine activation caused by bacterial endotoxin in men, possibly due to the pharmacological modulation of the cholinergic anti-inflammatory pathway. Oxytocin might be a candidate for the therapy of inflammatory diseases and conditions associated with high cytokine and VEGF levels.

The Neuroendocrine–Immune Interactions in Systemic Lupus Erythematosus: A Basis for Understanding Disease Pathogenesis and Complexity

Much progress has been made in the understanding of the impact of the neuroendocrine immune interactions and the pathogenic role in systemic lupus erythematosus, clinically and at the molecular level. This article focuses on the intertwining networks that involve the hypothalamic-pituitary-adrenal axis, cytokines within the central nervous system, and the sympathetic system. Hormones (estrogen, prolactin, gonadotropin-releasing hormone, and leptin) play an important role as immunomodulatory agents.

Overtraining, excessive exercise, and altered immunity: is this a T helper-1 versus T helper-2 lymphocyte response?

Overtraining syndrome (OTS) occurs where an athlete is training vigorously, yet performance deteriorates. One sign of OTS is suppressed immune function, with an increased incidence of upper respiratory tract infection (URTI). An increased incidence of URTIs is also associated with high volume/intensity training, as well as with excessive exercise (EE), such as a marathon, manifesting between 3-72 hours post-race. Presently, there is no encompassing theory to explain EE and altered immune competence. Recently, it has been conclusively established that T helper lymphocytes (T(H)), a crucial aspect of immune function, represent two distinct functional subsets: T(H)1 and T(H)2 lymphocytes. T(H)1 lymphocytes are associated with cell-mediated immunity (CMI) and the killing of intracellular pathogens, while T(H)2 lymphocytes are associated with humoral immunity and antibody production. When T(H)-precursor cells are activated, the balance is tipped in favour of one or the other. Furthermore, the most appropriate means of determining the T(H)-subset, is by the prevailing cytokine 'pattern'. This paper hypothesises that exercise-related immunosuppression is due to tissue trauma sustained during intense exercise, producing cytokines, which drive the development of a T(H)2 lymphocyte profile. A T(H)2 cell response results in simultaneous suppression of CMI, rendering the athlete susceptible to infection. Additionally, increased levels of circulating stress hormones (cortisol and catecholamines), as well as prostaglandin E(2), support up-regulation of T(H)2 lymphocytes. Marathon-related data are presented to support this hypothesis. It is concluded that an increased incidence of illness associated with OTS and in response to EE is not due to immunosuppression per se, but rather to an altered focus of immune function, with an up-regulation of humoral immunity and suppression of CMI.

Mechanisms and management of toxicities associated with high-dose interferon alfa-2b therapy

PURPOSE

The toxicity associated with adjuvant high-dose interferon-alfa-2b therapy (HDI) for high-risk melanoma can lead to premature discontinuation. It is important to understand the expected adverse events and their underlying mechanisms and to anticipate and aggressively manage toxicity during treatment in order to ensure that patients receive the maximum therapeutic benefit.

METHODS

The toxicity profile of HDI was reviewed by examining data from the United States cooperative group trials. Available published data related to the potential mechanisms responsible for the observed adverse events are discussed, and comprehensive recommendations for managing side effects are presented.

RESULTS

The HDI regimen is associated with acute constitutional symptoms, chronic fatigue, myelosuppression, elevated liver enzyme levels, and neurologic symptoms. The majority of patients tolerate 1 year of therapy with an understanding of the anticipated toxicities in conjunction with appropriate dose modifications and supportive care. Ongoing monitoring for liver dysfunction and hematologic toxicity is critical to ensure safety. Many of the toxicities associated with interferon-alfa (IFN-alpha) seem to be the result of endogenous cytokines and their effects on the neuroendocrine system. Recent data have also demonstrated that IFN-alpha suppresses the activity of specific CYP450 isoenzymes and that this correlates with discrete toxicities. Pharmacologic interventions are under study for fatigue and depression. An increased understanding of the mechanisms of IFN-alpha-associated toxicity will lead to more rational and effective supportive care and improved quality of life.

CONCLUSION

Continued research in this area should lead to improvements in the safety and tolerability of adjuvant therapy for melanoma.

Effects of D2-dopamine and alpha-adrenoceptor antagonists in stress induced changes on immune responsiveness of mice

The involvement of catecholamine receptors (alpha-adrenergic, D2-dopamine (DA)) was investigated in restraint stress influenced immune responses with concomitant changes of G-protein signal transduction. Impairment of the spleen morphology, TH1/TH2 cytokine network and natural killer (NK) cell function was observed. In vivo administration of specific antagonists prior to restraint stress reversed the immunosuppression. These findings demonstrate that D2-type dopaminergic mechanism represents the dominant component in regulation of Galphas/Galphai(1,2)/Galphaq/11-protein signal transduction and contribute to cell responses at postreceptor level of both, central nervous and immune systems. G-protein-coupled receptors (GPCRs) can modulate cytokine production and may play a regulatory role in immune effector mechanisms.

Neuroendocrine regulation of immunity

A reciprocal regulation exists between the central nervous and immune systems through which the CNS signals the immune system via hormonal and neuronal pathways and the immune system signals the CNS through cytokines. The primary hormonal pathway by which the CNS regulates the immune system is the hypothalamic-pituitary-adrenal axis, through the hormones of the neuroendocrine stress response. The sympathetic nervous system regulates the function of the immune system primarily via adrenergic neurotransmitters released through neuronal routes. Neuroendocrine regulation of immune function is essential for survival during stress or infection and to modulate immune responses in inflammatory disease. Glucocorticoids are the main effector end point of this neuroendocrine system and, through the glucocorticoid receptor, have multiple effects on immune cells and molecules. This review focuses on the regulation of the immune response via the neuroendocrine system. Particular details are presented on the effects of interruptions of this regulatory loop at multiple levels in predisposition and expression of immune diseases and on mechanisms of glucocorticoid effects on immune cells and molecules.

Neural-immune interactions in health and disease

Many lines of research have established the numerous routes by which the immune and central nervous systems (CNS) communicate. The CNS signals the immune system via hormonal and neuronal pathways and the immune system signals the CNS through similar routes via immune mediators and cytokines. The primary hormonal pathway by which the CNS regulates the immune system is the hypothalamic-pituitary-adrenal (HPA) axis, through the hormones of the neuroendocrine stress response. The sympathetic nervous system regulates immune system function primarily via adrenergic neurotransmitters released through neuronal routes. Neuroendocrine regulation of immune function is essential for survival during stress or infection and to modulate immune responses in inflammatory disease. Glucocorticoids are the main effector endpoint of the neuroendocrine response system.

Glucose disorders associated with HIV and its drug therapy

OBJECTIVE

To review the impact that factors such as HIV infection, antiretrovirals, and other commonly used drug therapies have on glucose metabolism in HIV-infected patients.

DATA SOURCES

Pertinent literature was identified via a MEDLINE search from 1980 to April 2000 and through secondary sources (abstracts presented at recent scientific meetings, manufacturers' package inserts). The key words used were antiretroviral therapy, HIV infection, insulin resistance, and metabolic abnormalities. All information deemed relevant to evaluate the impact that HIV infection and drug therapy have on glucose metabolism in HIV-infected patients was included.

DATA SYNTHESIS

The viral burden and stress that are present in HIV-infected patients elicit a complex hormonal and immunologic response that may alter various biochemical pathways, including glucose metabolism. Although rare before the era of potent antiretroviral therapy, insulin resistance has now been described as an important component of the lipodystrophy syndrome. The complex and multifactorial nature of glucose metabolism dysregulation makes management of hyperglycemia or diabetes mellitus challenging in HIV-infected patients. In such a context, a set of recommendations was developed to guide practitioners in assessing, treating, and monitoring hyperglycemia or diabetes mellitus in HIV-infected patients.

CONCLUSIONS

Alterations of glucose metabolism observed in HIV-infected patients are more frequent since the introduction of potent antiretroviral therapy. Although the etiology of such abnormalities remains unknown, protease inhibitors and, to a lesser extent, nucleoside reverse transcriptase inhibitors are believed to participate in their pathogenic mechanisms. Because of similarities to the pathogenesis of diabetes mellitus, management of antiretroviral-induced hyperglycemia could follow that the recommendations of the American Diabetes Association, with special considerations for monitoring patients with HIV infection. Future studies of altered glucose metabolism in HIV-infected patients should focus on understanding the precise mechanism or causes of this complication so that preventive and therapeutic guidelines can be further evaluated.

Chronic restraint stress promotes lymphocyte apoptosis by modulating CD95 expression

Depending on the duration and severity, psychological tension and physical stress can enhance or suppress the immune system in both humans and animals. Although it is well established that stress alters the release of various hormones and neurotransmitters, the mechanisms by which stress affects immune responses remain elusive. We report here that mice subjected to chronic 12-hour daily physical restraint for two days exhibited a significant reduction in splenocytes, a process likely mediated by apoptosis as demonstrated by the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling assay. CD95 (Fas/APO-1) expression in splenic lymphocytes of stressed mice was substantially increased. Interestingly, Fas-immunoglobulin fusion protein and blocking antibodies against CD95 ligand inhibit stress-induced reduction in lymphocytes. The stress-induced changes in CD95 expression and lymphocyte number could be blocked by naltrexone or naloxone, specific opioid receptor antagonists, indicating a pivotal role of endogenous opioids in this process. In addition, the reduction of splenocytes in this model system seems to be independent of the hypothalamo-pituitary-adrenal axis, as both adrenalectomized and sham-operated mice exhibited similar responses to chronic stress. Moreover, chronic physical restraint failed to induce a decrease in lymphocyte numbers in CD95-deficient (Fas(lpr/lpr)) mice. Therefore, stress modulates the immune system through CD95-mediated apoptosis dependent on endogenous opioids.

Measurement of cytokines in clinical samples using immunoassays: problems and pitfalls

With the explosion in interest in cytokines and an increasing understanding of their possible involvement in the pathogenesis of many diseases, the number of studies measuring cytokines in body fluids has increased markedly over the last 5 to 10 years. However, it is readily apparent from the literature that the level of awareness of the many factors that can potentially influence the results obtained is very low. Such factors are likely to contribute considerably to the disparities seen among similar types of study. These include assay properties such as standardization and specificity, type of sample and sample handling, and many biological influences such as age, sex, ethnic background, and diurnal rhythmicity. Clearly, it is not possible to control for all these factors, but a minimum evaluation of assays should be carried out as described, including recovery and parallelity studies using relevant samples and the establishment of reproducibility and normal healthy population levels. An awareness of these factors, which is the purpose of this review, may hopefully lead to an improvement in the quality of studies incorporating the measurement of cytokines in clinical samples and should aid in the interpretation of the data.