Mikroglia und immunologische Mechanismen in der neuropsychiatrischen Forschung

2014 ◽  
Vol 33 (11) ◽  
pp. 761-770
Author(s):  
M. J. Schwarz ◽  
B. Leitner ◽  
E. Weidinger ◽  
N. Müller

ZusammenfassungDie Psychoneuroimmunologie beschäftigt sich mit den Wechselwirkungen zwischen der (gesunden) Psyche, psychischen Störungen und dem Immunsystem. Inzwischen hat sich gezeigt, dass zumindest bei Subgruppen psychischer Störungen wie Schizophrenie und Depression ein entzündlicher Prozess bei der Pathogenese eine Rolle spielt. Da für Schizophrenie und Depression auf diesem Gebiet die meisten Befunde vorliegen, konzentriert sich diese Übersicht auf diese beiden Störungsbilder. Die differenzielle Aktivierung von Mikrogliazellen und Astrozyten als funktionelle Träger des Immunsystems im ZNS, trägt zur Typ-1/Typ-2-Inbalance bei. Das entzündliche Geschehen ist verbunden mit höherer Prostaglandin-E2 (PGE-2)-Produktion und erhöhter Cyclooxygenase-2 (COX-2)-Expression. Zunehmende Evidenz aus klinischen Studien mit COX-2-Inhibitoren weisen auf einen günstigen Effekt antiinflammatorischer Therapie bei Schizophrenie hin, speziell in frühen Stadien der Krankheit. Sowohl bei Depression als auch bei Schizophrenie ist die Vulnerabilitäts- Stress-Hypothese weitgehend akzeptiert. So zeigte sich z. B. dass – bei entsprechender genetischer Disposition – Stress im frühen Lebensalter oder Separationsstress mit einem Anstieg proinflammatorischer Zytokine einhergehen und zu einer Immunaktivierung führen. Die Interaktionen zwischen dem Immunsystem, Neurotransmittern und dem Tryptophan- Kynurenin-System sind entscheidende Komponenten für die Pathogenese von Stress und Depression. Eine antientzündliche Behandlung, z. B. mit dem COX-2-Inhibitor Celecoxib, zeigt antidepressive Effekte.

Endocrinology ◽  
2004 ◽  
Vol 145 (11) ◽  
pp. 5044-5048 ◽  
Author(s):  
Kyoko Kagiwada ◽  
Dai Chida ◽  
Tomoya Sakatani ◽  
Masahide Asano ◽  
Aya Nambu ◽  
...  

Abstract IL-1 is an endogenous pyrogen produced upon inflammation or infection. Previously, we showed that, upon injection with turpentine, IL-1 is induced in the brain in association with the development of fever. The role of endogenous IL-1 in the brain and the signaling cascade to activate thermosensitive neurons, however, remain to be elucidated. In this report, febrile response was analyzed after peripheral injection of IL-1α. We found that a normal febrile response was induced even in IL-1α/β-deficient mice, indicating that production of IL-1 in the brain is not necessarily required for the response. In contrast, IL-6-deficient mice did not exhibit a febrile response. Cyclooxygenase (Cox)-2 expression in the brain was strongly induced 1.5 h after injection of IL-1α, whereas IL-6 expression was observed 3 h after the injection. Cox-2 expression in the brain was not influenced by IL-6 deficiency, whereas indomethacin, an inhibitor of cyclooxygenases, completely inhibited induction of IL-6. These observations suggest a mechanism of IL-1-induced febrile response in which IL-1 in the blood activates Cox-2, with the resulting prostaglandin E2 inducing IL-6 in the brain, leading to the development of fever.


2000 ◽  
Vol 48 (2) ◽  
pp. 191
Author(s):  
Sung Yong Lee ◽  
Sin Hyung Lee ◽  
Ki Hwan Jung ◽  
Byung Gyu Kim ◽  
Hae Chul Jung ◽  
...  

2002 ◽  
Vol 16 (9) ◽  
pp. 2145-2154 ◽  
Author(s):  
Xiao Han ◽  
Songyuan Chen ◽  
Yujie Sun ◽  
Jerry L. Nadler ◽  
David Bleich

Abstract Cyclooxygenase-2 (COX-2) gene and 12-lipoxygenase (12-LO) gene are preferentially expressed over other types of cyclooxygenase and lipoxygenase in pancreatic β-cells. Inhibition of either COX-2 or 12-LO can prevent cytokine-induced pancreatic β-cell dysfunction as defined by inhibition of glucose-stimulated insulin secretion. As cellular stress induces both genes and their respective end products in pancreatic β-cells, we evaluated the role of 12-hydroxyeicosatetraenoic acid (HETE) on COX-2 gene expression, protein expression, and prostaglandin E2 (PGE2) production. We demonstrate that 12-HETE significantly increases COX-2 gene expression and consequent product formation, whereas a closely related lipid, 15-HETE, does not. In addition, IL-1β-stimulated prostaglandin E2 production is completely inhibited by a preferential lipoxygenase inhibitor cinnaminyl-3,4-dihydroxy-α-cyanocinnamate. We then evaluated IL-1β-induced PGE2 production in islets purified from control C57BL/6 mice and 12-LO knockout mice lacking cytokine-inducible 12-HETE. IL-1β stimulated an 8-fold increase in PGE2 production in C57BL/6 islets but failed to stimulate PGE2 in 12-LO knockout islets. Addition of 12-HETE to 12-LO knockout islet cells produced a statistically significant rise in PGE2 production. Furthermore, 12-HETE, but not 15-HETE, stimulated COX-2 promoter and activator protein-1 binding activity. These data demonstrate that 12-HETE mediates cytokine-induced COX-2 gene transcription and resultant PGE2 production in pancreatic β-cells.


2019 ◽  
Vol 16 (1) ◽  
Author(s):  
Daniel S. Kikuchi ◽  
Ana Carolina P. Campos ◽  
Hongyan Qu ◽  
Steven J. Forrester ◽  
Rosana L. Pagano ◽  
...  

Abstract Background Sepsis-associated encephalopathy (SAE), a diffuse cerebral dysfunction in the absence of direct CNS infection, is associated with increased rates of mortality and morbidity in patients with sepsis. Increased cytokine production and disruption of the blood-brain barrier (BBB) are implicated in the pathogenesis of SAE. The induction of pro-inflammatory mediators is driven, in part, by activation of NF-κΒ. Lipopolysaccharide (LPS), an endotoxin produced by gram-negative bacteria, potently activates NF-κΒ and its downstream targets, including cyclooxygenase-2 (Cox-2). Cox-2 catalyzes prostaglandin synthesis and in the brain prostaglandin, E2 is capable of inducing endothelial permeability. Depletion of polymerase δ-interacting protein 2 (Poldip2) has previously been reported to attenuate BBB disruption, possibly via regulation of NF-κΒ, in response to ischemic stroke. Here we investigated Poldip2 as a novel regulator of NF-κΒ/cyclooxygenase-2 signaling in an LPS model of SAE. Methods Intraperitoneal injections of LPS (18 mg/kg) were used to induce BBB disruption in Poldip2+/+ and Poldip2+/− mice. Changes in cerebral vascular permeability and the effect of meloxicam, a selective Cox-2 inhibitor, were assessed by Evans blue dye extravasation. Cerebral cortices of Poldip2+/+ and Poldip2+/− mice were further evaluated by immunoblotting and ELISA. To investigate the role of endothelial Poldip2, immunofluorescence microscopy and immunoblotting were performed to study the effect of siPoldip2 on LPS-mediated NF-κΒ subunit p65 translocation and Cox-2 induction in rat brain microvascular endothelial cells. Finally, FITC-dextran transwell assay was used to assess the effect of siPoldip2 on LPS-induced endothelial permeability. Results Heterozygous deletion of Poldip2 conferred protection against LPS-induced BBB permeability. Alterations in Poldip2+/+ BBB integrity were preceded by induction of Poldip2, p65, and Cox-2, which was not observed in Poldip2+/− mice. Consistent with these findings, prostaglandin E2 levels were significantly elevated in Poldip2+/+ cerebral cortices compared to Poldip2+/− cortices. Treatment with meloxicam attenuated LPS-induced BBB permeability in Poldip2+/+ mice, while having no significant effect in Poldip2+/− mice. Moreover, silencing of Poldip2 in vitro blocked LPS-induced p65 nuclear translocation, Cox-2 expression, and endothelial permeability. Conclusions These data suggest Poldip2 mediates LPS-induced BBB disruption by regulating NF-κΒ subunit p65 activation and Cox-2 and prostaglandin E2 induction. Consequently, targeted inhibition of Poldip2 may provide clinical benefit in the prevention of sepsis-induced BBB disruption.


2021 ◽  
Vol 12 ◽  
Author(s):  
Nitin Kamble ◽  
Angila Gurung ◽  
Benedikt B. Kaufer ◽  
Ansar Ahmed Pathan ◽  
Shahriar Behboudi

Marek’s disease virus (MDV), an avian alphaherpesvirus, infects chickens, transforms CD4+ T cells, and induces immunosuppression early during infection. However, the exact mechanisms involved in MDV-induced immunosuppression are yet to be identified. Here, our results demonstrate that MDV infection in vitro and in vivo induces activation of cyclooxygenase-2 (COX-2) and production of prostaglandin E2 (PGE2). This exerts its inhibitory effects on T cell proliferation at day 21 post infection via PGE2 receptor 2 (EP2) and receptor 4 (EP4). Impairment of the MDV-induced T cell proliferation was associated with downregulation of IL-2 and transferrin uptake in a COX-2/PGE2 dependent manner in vitro. Interestingly, oral administration of a COX-2 inhibitor, meloxicam, during MDV infection inhibited COX-2 activation and rescued T cell proliferation at day 21 post infection. Taken together, our results reveal a novel mechanism that contributes to immunosuppression in the MDV-infected chickens.


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