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Litvin DG, Denstaedt SJ, Borkowski LF, Nichols NL, Dick TE, Smith CB, Jacono FJ. Peripheral-to-central immune communication at the area postrema glial-barrier following bleomycin-induced sterile lung injury in adult rats. Brain Behav Immun 2020; 87:610-633. [PMID: 32097765 PMCID: PMC8895345 DOI: 10.1016/j.bbi.2020.02.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 02/02/2020] [Accepted: 02/13/2020] [Indexed: 02/07/2023] Open
Abstract
The pathways for peripheral-to-central immune communication (P → C I-comm) following sterile lung injury (SLI) are unknown. SLI evokes systemic and central inflammation, which alters central respiratory control and viscerosensory transmission in the nucleus tractus solitarii (nTS). These functional changes coincide with increased interleukin-1 beta (IL-1β) in the area postrema, a sensory circumventricular organ that connects P → C I-comm to brainstem circuits that control homeostasis. We hypothesize that IL-1β and its downstream transcriptional target, cyclooxygenase-2 (COX-2), mediate P → C I-comm in the nTS. In a rodent model of SLI induced by intratracheal bleomycin (Bleo), the sigh frequency and duration of post-sigh apnea increased in Bleo- compared to saline- treated rats one week after injury. This SLI-dependent change in respiratory control occurred concurrently with augmented IL-1β and COX-2 immunoreactivity (IR) in the funiculus separans (FS), a barrier between the AP and the brainstem. At this barrier, increases in IL-1β and COX-2 IR were confined to processes that stained for glial fibrillary acidic protein (GFAP) and that projected basolaterally to the nTS. Further, FS radial-glia did not express TNF-α or IL-6 following SLI. To test our hypothesis, we blocked central COX-1/2 activity by intracerebroventricular (ICV) infusion of Indomethacin (Ind). Continuous ICV Ind treatment prevented Bleo-dependent increases in GFAP + and IL-1β + IR, and restored characteristics of sighs that reset the rhythm. These data indicate that changes in sighs following SLI depend partially on activation of a central COX-dependent P → C I-comm via radial-glia of the FS.
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Affiliation(s)
- David G Litvin
- Department of Physiology & Biophysics, Case Western Reserve University School of Medicine, Cleveland, OH 44106, United States; Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, OH 44106, United States; Department of Fundamental Neuroscience, University of Lausanne, 1005 Lausanne, Switzerland
| | - Scott J Denstaedt
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, OH 44106, United States; Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI 48109, United States
| | - Lauren F Borkowski
- Department of Biomedical Sciences, University of Missouri College of Veterinary Medicine, Columbia, MO 65212, United States
| | - Nicole L Nichols
- Department of Biomedical Sciences, University of Missouri College of Veterinary Medicine, Columbia, MO 65212, United States
| | - Thomas E Dick
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, OH 44106, United States; Department of Neurosciences, Case Western Reserve University School of Medicine, Cleveland, OH 44106, United States
| | - Corey B Smith
- Department of Physiology & Biophysics, Case Western Reserve University School of Medicine, Cleveland, OH 44106, United States
| | - Frank J Jacono
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, OH 44106, United States; Division of Pulmonary, Critical Care and Sleep Medicine, Louis Stokes VA Medical Center, Cleveland, OH 44106, United States.
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Dangarembizi R, Erlwanger KH, Rummel C, Roth J, Madziva MT, Harden LM. Brewer's yeast is a potent inducer of fever, sickness behavior and inflammation within the brain. Brain Behav Immun 2018; 68:211-223. [PMID: 29074357 DOI: 10.1016/j.bbi.2017.10.019] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Revised: 10/08/2017] [Accepted: 10/21/2017] [Indexed: 02/08/2023] Open
Abstract
Brewer's yeast, derived from the yeast species Saccharomyces cerevisiae (S. cerevisiae), is commonly used for inducing pyrexia in pharmacological studies screening antipyretics in rats. Despite its widespread use, the peripheral and central inflammatory response associated with Brewer's yeast-induced fever and sickness behavior in rats has not been investigated. Thus, we injected male Sprague-Dawley rats (150-200 g) subcutaneously with a high (4 g/kg, n = 9), medium (2 g/kg, n = 5) or low (0.4 g/kg, n = 6) dose of Brewer's yeast solution or saline (0.9%, n = 6) and measured core body temperature, cage activity, food intake and body mass for six days after injection. Blood and brain samples were collected at 2, 8, 18 and 72 h after injection; n = 5-7 per time point. Brewer's yeast administration dose-dependently induced fever, lethargy, anorexia and body mass stunting that was accompanied by increased blood plasma levels of interleukin (IL)-6 and tumor necrosis factor (TNF)-α and activation of inflammatory transcription factors (nuclear factor (NF) for interleukin-6, signal transducer and activator of transcription (STAT)-3, and NF-κB)) in the hypothalamus and circumventricular organs. The increased activation of transcription factors following Brewer's yeast administration was accompanied by increased hypothalamic mRNA expression of TNF-α, IL-1β and IL-6 and rate-limiting enzymes for prostaglandin synthesis. Our results show that subcutaneous administration of S. cerevisae induces prolonged fever, anorexia and lethargy that is accompanied by a pronounced increase in the synthesis of pro-inflammatory cytokines, key prostaglandin synthesizing enzymes and transcription factors, in the periphery and brain.
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Affiliation(s)
- R Dangarembizi
- Brain Function Research Group, School of Physiology, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, 2193 Johannesburg, South Africa; Department of Physiology and Anatomy, Faculty of Medicine, National University of Science and Technology, Box AC939, Ascot, Bulawayo, Zimbabwe.
| | - K H Erlwanger
- School of Physiology, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, 2193 Johannesburg, South Africa
| | - C Rummel
- Institute of Veterinary Physiology and Biochemistry, Justus-Liebig University Giessen, Frankfurter Strasse 100, D-35392 Giessen, Germany
| | - J Roth
- Institute of Veterinary Physiology and Biochemistry, Justus-Liebig University Giessen, Frankfurter Strasse 100, D-35392 Giessen, Germany
| | - M T Madziva
- School of Physiology, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, 2193 Johannesburg, South Africa
| | - L M Harden
- Brain Function Research Group, School of Physiology, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, 2193 Johannesburg, South Africa
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Xiang Y, Liao XH, Li JP, Li H, Qin H, Yao A, Yu CX, Hu P, Guo W, Gu CJ, Zhang TC. Myocardin and Stat3 act synergistically to inhibit cardiomyocyte apoptosis. Oncotarget 2017; 8:99612-99623. [PMID: 29245928 PMCID: PMC5725119 DOI: 10.18632/oncotarget.20450] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Accepted: 07/26/2017] [Indexed: 02/07/2023] Open
Abstract
Signal transducer and activator of transcription 3 (Stat3) and Myocardin regulate cardiomyocyte differentiation, proliferation, and apoptosis. We report a novel aspect of the cellular function of Myocardin and Stat3 in the regulation of cardiomyocyte apoptosis. Myocardin and Stat3 showed anti-apoptotic function by increasing the expression of Bcl-2 while reducing expression of the pro-apoptotic genes Bax, Apaf-1, caspase-9, and caspase-3. Moreover, myocardin/Stat3-mediated activation of Bcl-2 and Mcl-1 transcription is contingent on the CArG box. Myocardin and Stat3 synergistically inhibited staurosporine-induced cardiomyocyte apoptosis by up-regulating expression of anti-apoptotic Bcl-2 and Mcl-1 in neonatal rat cardiomyocytes. These results describe a novel anti-apoptotic Myocardin/Stat3 signaling pathway operating during cardiomyocyte apoptosis. This provides a molecular explanation for cardiomyocyte apoptosis inhibition as a critical component of myocardial protection.
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Affiliation(s)
- Yuan Xiang
- Institute of Biology and Medicine, Wuhan University of Science and Technology, Hubei, 430081, P.R. China
| | - Xing-Hua Liao
- Institute of Biology and Medicine, Wuhan University of Science and Technology, Hubei, 430081, P.R. China
| | - Jia-Peng Li
- Institute of Biology and Medicine, Wuhan University of Science and Technology, Hubei, 430081, P.R. China
| | - Hui Li
- Institute of Biology and Medicine, Wuhan University of Science and Technology, Hubei, 430081, P.R. China
| | - Huan Qin
- Institute of Biology and Medicine, Wuhan University of Science and Technology, Hubei, 430081, P.R. China
| | - Ao Yao
- Institute of Biology and Medicine, Wuhan University of Science and Technology, Hubei, 430081, P.R. China
| | - Cheng-Xi Yu
- Institute of Biology and Medicine, Wuhan University of Science and Technology, Hubei, 430081, P.R. China
| | - Peng Hu
- Institute of Biology and Medicine, Wuhan University of Science and Technology, Hubei, 430081, P.R. China
| | - Wei Guo
- Shenzhen Ritzcon Biological Technology Co., LTD, Shenzhen, Guangdong, 518000, P.R. China
| | - Chao-Jiang Gu
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education and Tianjin, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, P.R. China
| | - Tong-Cun Zhang
- Institute of Biology and Medicine, Wuhan University of Science and Technology, Hubei, 430081, P.R. China.,Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education and Tianjin, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, P.R. China
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Inflammatory transcription factors as activation markers and functional readouts in immune-to-brain communication. Brain Behav Immun 2016; 54:1-14. [PMID: 26348582 DOI: 10.1016/j.bbi.2015.09.003] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Revised: 08/31/2015] [Accepted: 09/04/2015] [Indexed: 02/06/2023] Open
Abstract
Immune-to-brain communication pathways involve humoral mediators, including cytokines, central modulation by neuronal afferents and immune cell trafficking to the brain. During systemic inflammation these pathways contribute to mediating brain-controlled sickness symptoms including fever. Experimentally, activation of these signaling pathways can be mimicked and studied when injecting animals with pathogen associated molecular patterns (PAMPS). One central component of the brain inflammatory response, which leads, for example, to fever induction, is transcriptional activation of brain cells via cytokines and PAMPS. We and others have studied the spatiotemporal activation and the physiological significance of transcription factors for the induction of inflammation within the brain and the manifestation of fever. Evidence has revealed a role of nuclear factor (NF)κB in the initiation, signal transducer and activator of transcription (STAT)3 in the maintenance and NF-interleukin (IL)6 in the maintenance or even termination of brain-inflammation and fever. Moreover, psychological stressors, such as exposure to a novel environment, leads to increased body core temperature and genomic NF-IL6-activation, suggesting a potential use of NF-IL6-immunohistochemistry as a multimodal brain cell activation marker and a role for NF-IL6 for differential brain activity. In addition, the nutritional status, as reflected by circulating levels of the cytokine-like hormone leptin, influence immune-to-brain communication and age-dependent changes in LPS-induced fever. Overall, transcription factors remain therapeutically important targets for the treatment of brain-inflammation and fever induction during infectious/non-infectious inflammatory and psychological stress. However, the exact physiological role and significance of these transcription factors requires to be further investigated.
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Cerebral Response to Peripheral Challenge with a Viral Mimetic. Neurochem Res 2015; 41:144-55. [PMID: 26526143 DOI: 10.1007/s11064-015-1746-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Revised: 10/22/2015] [Accepted: 10/24/2015] [Indexed: 10/22/2022]
Abstract
It has been well established that peripheral inflammation resulting from microbial infections profoundly alters brain function. This review focuses on experimental systems that model cerebral effects of peripheral viral challenge. The most common models employ the induction of the acute phase response via intraperitoneal injection of a viral mimetic, polyinosinic-polycytidylic acid (PIC). The ensuing transient surge of blood-borne inflammatory mediators induces a "mirror" inflammatory response in the brain characterized by the upregulated expression of a plethora of genes encoding cytokines, chemokines and other inflammatory/stress proteins. These inflammatory mediators modify the activity of neuronal networks leading to a constellation of behavioral traits collectively categorized as the sickness behavior. Sickness behavior is an important protective response of the host that has evolved to enhance survival and limit the spread of infections within a population. However, a growing body of clinical data indicates that the activation of inflammatory pathways in the brain may constitute a serious comorbidity factor for neuropathological conditions. Such comorbidity has been demonstrated using the PIC paradigm in experimental models of Alzheimer's disease, prion disease and seizures. Also, prenatal or perinatal PIC challenge has been shown to disrupt normal cerebral development of the offspring resulting in phenotypes consistent with neuropsychiatric disorders, such as schizophrenia and autism. Remarkably, recent studies indicate that mild peripheral PIC challenge may be neuroprotective in stroke. Altogether, the PIC challenge paradigm represents a unique heuristic model to elucidate the immune-to-brain communication pathways and to explore preventive strategies for neuropathological disorders.
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Roth J, Blatteis CM. Mechanisms of fever production and lysis: lessons from experimental LPS fever. Compr Physiol 2015; 4:1563-604. [PMID: 25428854 DOI: 10.1002/cphy.c130033] [Citation(s) in RCA: 116] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Fever is a cardinal symptom of infectious or inflammatory insults, but it can also arise from noninfectious causes. The fever-inducing agent that has been used most frequently in experimental studies designed to characterize the physiological, immunological and neuroendocrine processes and to identify the neuronal circuits that underlie the manifestation of the febrile response is lipopolysaccharide (LPS). Our knowledge of the mechanisms of fever production and lysis is largely based on this model. Fever is usually initiated in the periphery of the challenged host by the immediate activation of the innate immune system by LPS, specifically of the complement (C) cascade and Toll-like receptors. The first results in the immediate generation of the C component C5a and the subsequent rapid production of prostaglandin E2 (PGE2). The second, occurring after some delay, induces the further production of PGE2 by induction of its synthesizing enzymes and transcription and translation of proinflammatory cytokines. The Kupffer cells (Kc) of the liver seem to be essential for these initial processes. The subsequent transfer of the pyrogenic message from the periphery to the brain is achieved by neuronal and humoral mechanisms. These pathways subserve the genesis of early (neuronal signals) and late (humoral signals) phases of the characteristically biphasic febrile response to LPS. During the course of fever, counterinflammatory factors, "endogenous antipyretics," are elaborated peripherally and centrally to limit fever in strength and duration. The multiple interacting pro- and antipyretic signals and their mechanistic effects that underlie endotoxic fever are the subjects of this review.
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Affiliation(s)
- Joachim Roth
- Department of Veterinary Physiology and Biochemistry, Justus-Liebig-University, Giessen, Germany; Department of Physiology, College of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee
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Bastos-Pereira AL, Leite MCG, Fraga D, Zampronio AR. Central mediators involved in the febrile response induced by polyinosinic-polycytidylic acid: lack of involvement of endothelins and substance P. J Neuroimmunol 2014; 278:100-7. [PMID: 25595258 DOI: 10.1016/j.jneuroim.2014.12.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Revised: 12/08/2014] [Accepted: 12/11/2014] [Indexed: 12/18/2022]
Abstract
The present study evaluated the involvement of interleukin(IL)-1β, tumor necrosis factor-α (TNF-α), IL-6, interferon(IFN)-γ, prostaglandins of the E2 series, endothelins, substance P and opioids within the central nervous system in polyinosinic:polycytidylic acid (Poly I:C)-induced fever in rats. Poly I:C injection induced a febrile response which was reduced by intracerebroventricular administration of the antibodies against TNF-α, IL-6, or IFN-γ, or by IL-1 or μ receptor antagonists. Intraperitoneal injection of indomethacin or oral administration of celecoxib also reduced Poly I:C-induced fever. Poly I:C increased prostaglandin E2 levels in the cerebrospinal fluid of the animals which was also reduced by indomethacin. The intracerebroventricular injection of ETB or NK1 receptor antagonists did not alter Poly I:C-induced fever. These data suggest the involvement of IL-1β, TNF-α, IL-6, IFN-γ, prostaglandin E2, and opioids but not endothelins and substance P on Poly I:C-induced fever.
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Affiliation(s)
- A L Bastos-Pereira
- Department of Pharmacology, Federal University of Paraná, P.O. Box 19031, 81540-970 Curitiba, PR, Brazil
| | - M C G Leite
- Department of Pharmacology, Federal University of Paraná, P.O. Box 19031, 81540-970 Curitiba, PR, Brazil
| | - D Fraga
- Department of Pharmacology, Federal University of Paraná, P.O. Box 19031, 81540-970 Curitiba, PR, Brazil
| | - A R Zampronio
- Department of Pharmacology, Federal University of Paraná, P.O. Box 19031, 81540-970 Curitiba, PR, Brazil.
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Damm J, Wiegand F, Harden LM, Wenisch S, Gerstberger R, Rummel C, Roth J. Intraperitoneal and subcutaneous injections of the TLR9 agonist ODN 1668 in rats: brain inflammatory responses are related to peripheral IL-6 rather than interferons. J Neuroimmunol 2014; 277:105-17. [PMID: 25465287 DOI: 10.1016/j.jneuroim.2014.10.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Revised: 10/20/2014] [Accepted: 10/21/2014] [Indexed: 12/30/2022]
Abstract
Subcutaneous or intraperitoneal administration of Toll-like receptor (TLR)-9 agonist, ODN 1668 caused moderate fever and anorexia. In comparison to stimulation of other intracellular TLRs, activation of TLR9 did not result in pronounced peripheral induction of interferons, but rather induced interleukin-6. Expression of cytokines (TNFα, IL-1β) and inducible forms of enzymes for prostaglandin E2 synthesis occurred in the brain, in conjunction with a moderate activation of the transcription factors STAT3 and NF-IL6 in brain endothelial cells. The lack of a septic-like state in ODN 1668-treated rats reinforces the therapeutic value of this drug.
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Affiliation(s)
- J Damm
- Institute of Veterinary-Physiology and -Biochemistry, Justus-Liebig-University of Giessen, Frankfurter Strasse 100, D-35392 Giessen, Germany
| | - F Wiegand
- Institute of Veterinary-Physiology and -Biochemistry, Justus-Liebig-University of Giessen, Frankfurter Strasse 100, D-35392 Giessen, Germany
| | - L M Harden
- Institute of Veterinary-Physiology and -Biochemistry, Justus-Liebig-University of Giessen, Frankfurter Strasse 100, D-35392 Giessen, Germany; Brain Function Research Group, School of Physiology, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, Johannesburg, South Africa
| | - S Wenisch
- Institute of Veterinary-Anatomy, Justus-Liebig-University of Giessen, Frankfurter Strasse 98, D-35392 Giessen, Germany
| | - R Gerstberger
- Institute of Veterinary-Physiology and -Biochemistry, Justus-Liebig-University of Giessen, Frankfurter Strasse 100, D-35392 Giessen, Germany
| | - C Rummel
- Institute of Veterinary-Physiology and -Biochemistry, Justus-Liebig-University of Giessen, Frankfurter Strasse 100, D-35392 Giessen, Germany
| | - J Roth
- Institute of Veterinary-Physiology and -Biochemistry, Justus-Liebig-University of Giessen, Frankfurter Strasse 100, D-35392 Giessen, Germany.
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Fuchs F, Damm J, Gerstberger R, Roth J, Rummel C. Activation of the inflammatory transcription factor nuclear factor interleukin-6 during inflammatory and psychological stress in the brain. J Neuroinflammation 2013; 10:140. [PMID: 24279606 PMCID: PMC4222273 DOI: 10.1186/1742-2094-10-140] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2013] [Accepted: 11/12/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The transcription factor nuclear factor interleukin 6 (NF-IL6) is known to be activated by various inflammatory stimuli in the brain. Interestingly, we recently detected NF-IL6-activation within the hypothalamus-pituitary-adrenal (HPA)-axis of rats after systemic lipopolysaccharide (LPS)-injection. Thus, the aim of the present study was to investigate whether NF-IL6 is activated during either, inflammatory, or psychological stress in the rat brain. METHODS Rats were challenged with either the inflammatory stimulus LPS (100 μg/kg, i.p.) or exposed to a novel environment. Core body temperature (Tb) and motor activity were monitored using telemetry, animals were killed at different time points, brains and blood removed, and primary cell cultures of the anterior pituitary lobe (AL) were investigated. Analyses were performed using immunohistochemistry, RT-PCR, and cytokine-specific bioassays. RESULTS Stress stimulation by a novel environment increased NF-IL6-immunoreactivity (IR) in the pituitary's perivascular macrophages and hypothalamic paraventricular cells and a rise in Tb lasting approximately 2 h. LPS stimulation lead to NF-IL6-IR in several additional cell types including ACTH-IR-positive corticotrope cells in vivo and in vitro. Two other proinflammatory transcription factors, namely signal transducer and activator of transcription (STAT)3 and NFκB, were significantly activated and partially colocalized with NF-IL6-IR in cells of the AL only after LPS-stimulation, but not following psychological stress. In vitro NF-IL6-activation was associated with induction and secretion of TNFα in folliculostellate cells, which could be antagonized by the JAK-STAT-inhibitor AG490. CONCLUSIONS We revealed, for the first time, that NF-IL6 activation occurs not only during inflammatory LPS stimulation, but also during psychological stress, that is, a novel environment. Both stressors were associated with time-dependent activation of NF-IL6 in different cell types of the brain and the pituitary. Moreover, while NF-IL6-IR was partially linked to STAT3 and NFκB activation, TNFα production, and ACTH-IR after LPS stimulation; this was not the case after exposure to a novel environment, suggesting distinct underlying signaling pathways. Overall, NF-IL6 can be used as a broad activation marker in the brain and might be of interest for therapeutic approaches not only during inflammatory but also psychological stress.
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Affiliation(s)
- Franziska Fuchs
- Department of Veterinary-Physiology and -Biochemistry, Justus-Liebig-University Giessen, Frankfurter Strasse 100, Giessen D-35392, Germany
| | - Jelena Damm
- Department of Veterinary-Physiology and -Biochemistry, Justus-Liebig-University Giessen, Frankfurter Strasse 100, Giessen D-35392, Germany
| | - Rüdiger Gerstberger
- Department of Veterinary-Physiology and -Biochemistry, Justus-Liebig-University Giessen, Frankfurter Strasse 100, Giessen D-35392, Germany
| | - Joachim Roth
- Department of Veterinary-Physiology and -Biochemistry, Justus-Liebig-University Giessen, Frankfurter Strasse 100, Giessen D-35392, Germany
| | - Christoph Rummel
- Department of Veterinary-Physiology and -Biochemistry, Justus-Liebig-University Giessen, Frankfurter Strasse 100, Giessen D-35392, Germany
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Wang X, Ao H, Zhai L, Bai L, He W, Yu Y, Wang C. Genome-wide effects of DNA methyltransferase inhibitor on gene expression in double-stranded RNA transfected porcine PK15 cells. Genomics 2013; 103:371-9. [PMID: 24184360 DOI: 10.1016/j.ygeno.2013.10.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2013] [Revised: 09/29/2013] [Accepted: 10/22/2013] [Indexed: 12/20/2022]
Abstract
Double-stranded RNA (dsRNA) is produced in host cells during viral replication. The effects of DNA demethylation on gene expression in dsRNA transfected swine cells are unclear. The study aims to profile the transcriptome changes which are induced by DNA methyltransferase inhibitor (Aza-CdR) in porcine PK15 cells transfected with viral-like dsRNA (Poly(I:C)). A total of 44, 76 and 952 differentially expressed genes (DEGs) were detected in the cells treated by Poly(I:C) plus Aza-CdR (P+A), Poly(I:C) (P) or Aza-CdR (A) alone compared to the controls (C). Immune response-related pathways are observed in the comparison of A vs. C and P vs. C, and the genes in the pathways were recovered in the comparison of (P+A) vs. C. GO analysis indicated that Aza-CdR has negative regulatory effects on viral reproduction. The results suggest that the stimulant of Poly(I:C) could be regressed by Aza-CdR. These observations provide new insights into the epigenetic regulatory effects on viral replication.
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Affiliation(s)
- Xiaoshuo Wang
- National Engineering Laboratory for Animal Breeding, Key Laboratory of Agricultural Animal Genetics and Breeding, Department of Animal Breeding and Genetics, College of Animal Sciences and Technology, China Agricultural University, Beijing 100193, China
| | - Hong Ao
- State Key Laboratory for Animal Nutrition, Key Laboratory for Domestic Animal Genetic Resources and Breeding of the Ministry of Agriculture of China, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Liwei Zhai
- National Engineering Laboratory for Animal Breeding, Key Laboratory of Agricultural Animal Genetics and Breeding, Department of Animal Breeding and Genetics, College of Animal Sciences and Technology, China Agricultural University, Beijing 100193, China
| | - Lijing Bai
- State Key Laboratory for Animal Nutrition, Key Laboratory for Domestic Animal Genetic Resources and Breeding of the Ministry of Agriculture of China, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Weiyong He
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Ying Yu
- National Engineering Laboratory for Animal Breeding, Key Laboratory of Agricultural Animal Genetics and Breeding, Department of Animal Breeding and Genetics, College of Animal Sciences and Technology, China Agricultural University, Beijing 100193, China.
| | - Chuduan Wang
- National Engineering Laboratory for Animal Breeding, Key Laboratory of Agricultural Animal Genetics and Breeding, Department of Animal Breeding and Genetics, College of Animal Sciences and Technology, China Agricultural University, Beijing 100193, China.
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Duncan M, Galic MA, Wang A, Chambers AP, McCafferty DM, McKay DM, Sharkey KA, Pittman QJ. Cannabinoid 1 receptors are critical for the innate immune response to TLR4 stimulation. Am J Physiol Regul Integr Comp Physiol 2013; 305:R224-31. [PMID: 23739343 DOI: 10.1152/ajpregu.00104.2013] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Sickness behaviors are host defense adaptations that arise from integrated autonomic outputs in response to activation of the innate immune system. These behaviors include fever, anorexia, and hyperalgesia intended to promote survival of the host when encountering pathogens. Cannabinoid (CB) receptor activation can induce hypothermia and attenuate LPS-evoked fever. The aim of the present study was to examine the role of CB1 receptors in the LPS-evoked febrile response. CB1 receptor-deficient (CB1(-/-)) mice did not display LPS-evoked fever; likewise, pharmacological blockade of CB1 receptors in wild-type mice blocked LPS-evoked fever. This unresponsiveness is not limited to thermogenesis, as the animals were not hyperalgesic after LPS administration. A Toll-like receptor (TLR)3 agonist and viral mimetic polyinosinic:polycytidylic acid evoked a robust fever in CB1(-/-) mice, suggesting TLR3-mediated responses are functional. LPS-evoked c-Fos activation in areas of the brain associated with the febrile response was evident in wild-type mice but not in CB1(-/-) mice. Liver and spleen TLR4 mRNA were significantly lower in CB1(-/-) mice compared with wild-type mice, and peritoneal macrophages from CB1(-/-) mice did not release proinflammatory cytokines in response to LPS. These data indicate that CB1 receptors play a critical role in LPS-induced febrile responses through inhibiting TLR4-mediated cytokine production.
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Affiliation(s)
- Marnie Duncan
- Hotchkiss Brain Institute and Snyder Institute for Chronic Diseases, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
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Hourai A, Miyata S. Neurogenesis in the circumventricular organs of adult mouse brains. J Neurosci Res 2013; 91:757-70. [PMID: 23526379 DOI: 10.1002/jnr.23206] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2012] [Revised: 12/10/2012] [Accepted: 12/21/2012] [Indexed: 12/20/2022]
Abstract
The circumventricular organs (CVOs), including the organum vasculosum of the lamina terminalis (OVLT), subfornical organ (SFO), median eminence (ME), and area postrema (AP), allow parenchyma cells to sense a variety of blood-derived substances and/or secreted peptides into blood circulation. In the present study, we examined continuous neurogenesis in the CVOs of adult mice. The immunohistochemistry of neural progenitor cell (NPC) marker proteins revealed that Math1- and Mash1-positive cells were observed in the discrete regions of CVOs, including the capillary plexus in the OVLT, the internal zone of the ME, and the lateral zone in the AP. A few Mash1- and Math1-positive cells were seen throughout the SFO, and many Math1- but not Mash1-positive cells were observed at the arcuate nucleus. Math-positive cells were often seen to localize in close proximity to the vasculature. Bromodeoxyuridine (BrdU) immunohistochemistry revealed the incorporation of BrdU in a subpopulation of Mash1-, Math1-, HuC/D-, and microtubule-associated protein 2 (MAP2)-positive cells. Mash1- and Math1-positive cells expressed exclusively high level of plasminogen, whereas a subpopulation of HuC/D- and MAP2-positive neurons expressed low or undetectable level of plasminogen. Thus, the present study demonstrates that newborn cells express NPC marker proteins and plasminogen to localize closely at vascular matrix and moreover differentiate into neurons expressing mature neuron marker proteins, indicating that new neurons are possibly generated to integrate into new neural circuits.
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Affiliation(s)
- Atsushi Hourai
- Department of Applied Biology, Kyoto Institute of Technology, Kyoto, Japan
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Mannari T, Morita S, Furube E, Tominaga M, Miyata S. Astrocytic TRPV1 ion channels detect blood-borne signals in the sensory circumventricular organs of adult mouse brains. Glia 2013; 61:957-71. [PMID: 23468425 DOI: 10.1002/glia.22488] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2012] [Revised: 01/02/2013] [Accepted: 01/29/2013] [Indexed: 01/12/2023]
Abstract
The circumventricular organs (CVOs), including the organum vasculosum of the lamina terminalis (OVLT), subfornical organ (SFO), and area postrema (AP) sense a variety of blood-borne molecules because they lack typical blood-brain barrier. Though a few signaling pathways are known, it is not known how endogenous ligands for transient receptor potential vanilloid receptor 1 ion channel (TRPV1) are sensed in the CVOs. In this study, we aimed to examine whether or not astrocytic TRPV1 senses directly blood-borne molecules in the OVLT, SFO, and AP of adult mice. The reverse transcription-polymerase chain reaction and Western analysis revealed the expression of TRPV1 in the CVOs. Confocal microscopic immunohistochemistry further showed that TRPV1 was localized prominently at thick cellular processes of astrocytes rather than fine cellular processes and cell bodies. TRPV1-expressing cellular processes of astrocytes surrounded the vasculature to constitute dense networks. The expression of TRPV1 was also found at neuronal dendrites but not somata in the CVOs. The intravenous administration of a TRPV1 agonist resiniferatoxin (RTX) prominently induced Fos expression at astrocytes in the OVLT, SFO, and AP and neurons in adjacent related nuclei of the median preoptic nuclei (MnPO) and nucleus of the solitary tract (Sol) of wild-type but not TRPV1-knockout mice. The intracerebroventricular infusion of RTX induced Fos expression at both astrocytes and neurons in the CVOs, MnPO, and Sol. Thus, this study demonstrates that blood-borne molecules are sensed directly by astrocytic TRPV1 of the CVOs in adult mammalians.
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Affiliation(s)
- Tetsuya Mannari
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto, 606-8585, Japan
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Dragunow M. Meningeal and choroid plexus cells--novel drug targets for CNS disorders. Brain Res 2013; 1501:32-55. [PMID: 23328079 DOI: 10.1016/j.brainres.2013.01.013] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2012] [Accepted: 01/07/2013] [Indexed: 12/13/2022]
Abstract
The meninges and choroid plexus perform many functions in the developing and adult human central nervous system (CNS) and are composed of a number of different cell types. In this article I focus on meningeal and choroid plexus cells as targets for the development of drugs to treat a range of traumatic, ischemic and chronic brain disorders. Meningeal cells are involved in cortical development (and their dysfunction may be involved in cortical dysplasia), fibrotic scar formation after traumatic brain injuries (TBI), brain inflammation following infections, and neurodegenerative disorders such as Multiple Sclerosis (MS) and Alzheimer's disease (AD) and other brain disorders. The choroid plexus regulates the composition of the cerebrospinal fluid (CSF) as well as brain entry of inflammatory cells under basal conditions and after injuries. The meninges and choroid plexus also link peripheral inflammation (occurring in the metabolic syndrome and after infections) to CNS inflammation which may contribute to the development and progression of a range of CNS neurological and psychiatric disorders. They respond to cytokines generated systemically and secrete cytokines and chemokines that have powerful effects on the brain. The meninges may also provide a stem cell niche in the adult brain which could be harnessed for brain repair. Targeting meningeal and choroid plexus cells with therapeutic agents may provide novel therapies for a range of human brain disorders.
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Affiliation(s)
- Mike Dragunow
- Department of Pharmacology and Centre for Brain Research, The University of Auckland, Auckland, New Zealand.
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Ott D, Wuchert F, Murgott J, Rummel C, Gerstberger R, Roth J. The viral mimetic polyinosinic:polycytidylic acid (poly I:C) induces cellular responses in primary cultures from rat brain sites with an incomplete blood-brain barrier. Neurosci Lett 2012; 530:64-8. [PMID: 23022505 DOI: 10.1016/j.neulet.2012.09.038] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2012] [Revised: 08/30/2012] [Accepted: 09/13/2012] [Indexed: 10/27/2022]
Abstract
Primary microcultures of the organum vasculosum laminae terminalis (OVLT) and the area postrema (AP), brain sites with an incomplete blood-brain barrier, were established from topographically excised rat pup tissue, with cellular identification by marker protein-specific immunocytochemistry. Employing the ratio calcium imaging technique, we showed for the first time that polyinosinic:polycytidylic acid (poly I:C) can induce calcium signalling in single OVLT and AP cells. Poly I:C stimulation caused fast, transient rises in intracellular calcium in about 5% of neurons and astrocytes and some microglial cells. Frequently, the responses of astrocytes and microglial cells showed a shorter onset-latency compared to neurons. In addition, exposure to poly I:C led to a time dependent release of bioactive tumour necrosis factor (TNF) and interleukin-6 (IL-6) into the supernatants of OVLT and AP cultures. The demonstration of direct cellular responses of OVLT- and AP-intrinsic cells to stimulations with poly I:C is in agreement with the discovered existence of Toll-like receptor 3 (TLR3), the cognate receptor for poly I:C, in the brain.
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Affiliation(s)
- Daniela Ott
- Department of Veterinary-Physiology and -Biochemistry, Justus-Liebig University Giessen, Frankfurter Strasse 100, D-35392 Giessen, Germany
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Rana SA, Aavani T, Pittman QJ. Sex effects on neurodevelopmental outcomes of innate immune activation during prenatal and neonatal life. Horm Behav 2012; 62:228-36. [PMID: 22516179 PMCID: PMC3522744 DOI: 10.1016/j.yhbeh.2012.03.015] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2012] [Revised: 03/25/2012] [Accepted: 03/28/2012] [Indexed: 11/15/2022]
Abstract
Humans are exposed to potentially harmful agents (bacteria, viruses, toxins) throughout our lifespan; the consequences of such exposure can alter central nervous system development. Exposure to immunogens during pregnancy increases the risk of developing neurological disorders such as schizophrenia and autism. Further, sex hormones, such as estrogen, have strong modulatory effects on immune function and have also been implicated in the development of neuropathologies (e.g., schizophrenia and depression). Similarly, animal studies have demonstrated that immunogen exposure in utero or during the neonatal period, at a time when the brain is undergoing maturation, can induce changes in learning and memory, as well as dopamine-mediated behaviors in a sex-specific manner. Literature that covers the effects of immunogens on innate immune activation and ultimately the development of the adult brain and behavior is riddled with contradictory findings, and the addition of sex as a factor only adds to the complexity. This review provides evidence that innate immune activation during critical periods of development may have effects on the adult brain in a sex-specific manner. Issues regarding sex bias in research as well as variability in animal models of immune function are discussed.
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Affiliation(s)
| | | | - Quentin J. Pittman
- Corresponding author at: Hotchkiss Brain Institute, Department of Physiology and Pharmacology, Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada. Fax: +1 403 283 2700. (Q.J. Pittman)
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Kamerman P, Skosana M, Loram L, Mitchell B, Weber J. Fever and inflammatory cytokine response in rats injected subcutaneously with viral double-stranded RNA analog, polyinosinic:polycytidylic acid (Poly-I:C). J Therm Biol 2011. [DOI: 10.1016/j.jtherbio.2011.07.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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Abstract
PURPOSE OF REVIEW We have summarized recent findings related to gastroduodenal mucosal defense as well as factors contributing to defensive failure, highlighting findings that illuminate new pathophysiological mechanisms. RECENT FINDINGS Gastroduodenal bicarbonate secretion is mediated by prostaglandin E receptors and stimulated by the prostone lubiprostone. Toll-like receptor (TLR)4 signaling is protective against gastric injury. Intestinal alkaline phosphatase (IAP) is a chemosensor that regulates the duodenal mucosal surface pH. Lipopolysaccharide (LPS) increases gastric permeability; IAP secreted during fat digestion may detoxify colonic LPS. NADPH oxidase activity mediates ischemia/reperfusion-related gastric mucosal damage. Heat shock protein 70 (HSP70) protects the gastric mucosa through inhibition of apoptosis, proinflammatory cytokines, and cell adhesion molecules (CAMs). HSP90 may be a contributing factor in impaired adaptive cytoprotection. Proteinase-activated receptor-1 (PAR-1) is protective against Helicobacter-induced gastritis, mediated by the suppression of proinflammatory pathways. IKK β/NF-κB signaling decreases chronic Helicobacter-induced inflammation by inhibiting cellular apoptosis and necrosis. Activation of A2A adenosine receptors decreases inflammation and gastritis but leads to persistent Helicobacter pylori infection. SUMMARY Enhanced understanding of the mechanisms of gastroduodenal defense and injury provides new insight into potential therapeutic targets, contributing towards the development of better tolerated and more effective therapies.
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Affiliation(s)
- Arushi deFoneska
- Greater Los Angeles Veteran Affairs Healthcare System, WLAVA Medical Center, Department of Medicine, UCLA School of Medicine, Los Angeles, California 90073, USA
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Zhang Y, Chen H, Yang L. Toll-like receptor 4 participates in gastric mucosal protection through Cox-2 and PGE2. Dig Liver Dis 2010; 42:472-6. [PMID: 20018573 DOI: 10.1016/j.dld.2009.10.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2009] [Revised: 10/21/2009] [Accepted: 10/28/2009] [Indexed: 02/05/2023]
Abstract
AIM To elucidate the role of Toll-like receptors (TLRs) in gastric cytoprotection after ethanol injury. METHODS C57BL/6J, C3H/HeOuJ and C3H/HeJ mice were used. All mice were killed 4h after ethanol administration. TLR4, cyclooxygenase-2 (Cox-2) and prostaglandin E(2) (PGE(2)) expression were measured by immunohistochemistry, western blotting and enzyme-linked immunosorbent assay (ELISA) separately. RESULTS The expression of TLR4 increased in C57BL/6J mice stomach 4h after ethanol injury. The cells expressing TLR4 included Cox-2 expressing cells and macrophages. The injury in C3H/HeJ mice was more severe than in C3H/HeOuJ mice 4h after ethanol injury. The expression of Cox-2 and PGE(2) only increased in C3H/HeOuJ mice. The number of macrophages and the expression of macrophage-inflammatory protein-2 (MIP-2) also increased only in C3H/HeOuJ mice. CONCLUSION TLR4 signal is activated in mice stomach 4h after ethanol injury. The protective effects of TLR4 signalling are mediated through the induction of Cox-2 expression and the production of PGE(2).
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Affiliation(s)
- Yan Zhang
- Division of Gastroenterology, West China Hospital of Sichuan University, GuoXue Street 37, Chengdu 610041, Sichuan, China.
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20
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Miguel JC, Chen J, Van Alstine WG, Johnson RW. Expression of inflammatory cytokines and Toll-like receptors in the brain and respiratory tract of pigs infected with porcine reproductive and respiratory syndrome virus. Vet Immunol Immunopathol 2010; 135:314-9. [PMID: 20189253 DOI: 10.1016/j.vetimm.2010.01.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2009] [Revised: 12/08/2009] [Accepted: 01/12/2010] [Indexed: 01/28/2023]
Abstract
The objective of this experiment was to evaluate the central and peripheral expression of selected pro-inflammatory cytokines and Toll-like receptors (TLRs) in pigs infected with porcine reproductive and respiratory syndrome virus (PRRSV). Twenty-four 8-week-old pigs were inoculated with either sterile medium or PRRSV. Pigs were monitored 14d after inoculation and then euthanized for tissue sample collection. PRRSV was detected in serum, lung and brain tissue of pigs given PRRSV but not in any tissue of pigs given medium. Infection with PRRSV increased serum levels of IL-1beta, IL-6, TNFalpha, and IFNgamma and elicited a mild transient fever and reduced growth performance. Infection by PRRSV also increased mRNA for the pro-inflammatory cytokines as well as mRNA for TLR3, TLR4, and TLR7 in the tracheobronchial lymph nodes. The TLR3, TLR4, TLR7 and most of the pro-inflammatory genes also were up-regulated in discrete brain areas of PRRSV-infected pigs. Collectively, the results indicate that following inoculation, PRRSV is present in the periphery and brain and that infection is associated with a peripheral and central pro-inflammatory response, fever, and reduced growth performance. The findings are interpreted to suggest the innate immune system of the brain is responsive to PRRSV infection.
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Affiliation(s)
- J C Miguel
- Department of Animal Sciences, University of Illinois, Urbana, IL 61801, United States
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Knorr C, Hübschle T, Murgott J, Mühlradt P, Gerstberger R, Roth J. Macrophage-activating lipopeptide-2 (MALP-2) induces a localized inflammatory response in rats resulting in activation of brain sites implicated in fever. Brain Res 2008; 1205:36-46. [PMID: 18353287 DOI: 10.1016/j.brainres.2008.02.021] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2008] [Revised: 02/06/2008] [Accepted: 02/07/2008] [Indexed: 10/22/2022]
Abstract
Macrophage-activating lipopeptide-2 (MALP-2) has been identified as the pathogen-associated molecular pattern of Mycoplasma fermentans, which causes stimulation of the innate immune system through the activation of the heterodimeric Toll-like receptors (TLRs) 2 and 6. Based on the reported protective effects of MALP-2 on healing of skin wounds, the central goal of this study was to evaluate the capacity of MALP-2 to induce a localized inflammatory response in an established model of a subcutaneous air pouch. Injections of MALP-2 into the pouch caused fever and some components of sickness behavior in rats. At the subcutaneous site of localized inflammation, a massive formation of tumor necrosis factor-alpha (TNF), interleukin-6 (IL-6), and prostaglandin E2 (PGE2) could be demonstrated in response to injections of MALP-2. Moderate amounts of IL-6 and PGE2 seemed to enter the systemic circulation of MALP-2-treated rats. The IL-6, which appeared in the blood after injection of MALP-2 into the air pouch was sufficient to cause a direct activation of brain cells in areas which lack a complete blood-brain barrier, namely in the sensory circumventricular organs (sCVOs), the organum vasculosum laminae terminalis (OVLT), the subfornical organ (SFO), and the area postrema (AP). The stimulation of cells at these brain sites was revealed by demonstration of a nuclear translocation of the transcription factor STAT3 (signal transducer and activator of transcription 3). Corresponding to the circulating levels of IL-6, the nuclear STAT3 activation of cells within the sCVOs was much less pronounced after local subcutaneous when compared to systemic treatment with MALP-2. In conclusion, cells within the subcutaneous compartment are activated by the TLR2/6 agonist MALP-2. Fever and sickness behavior induced by injection of MALP-2 into subcutaneous tissue may, in part, be mediated by a spillover of IL-6 from the subcutaneous site of inflammation into the blood to cause activation of brain sites which are implicated in the manifestation of these illness responses.
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Affiliation(s)
- Carolin Knorr
- Institut für Veterinär-Physiologie, Justus-Liebig-Universität Giessen, Frankfurter Strasse 100, D-35392 Giessen, Germany
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22
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Bielefeldt-Ohmann H, Tolnay AE, Reisenhauer C, Hansen T, Smirnova N, Van Campen H. Transplacental Infection with Non-Cytopathic Bovine Viral Diarrhoea Virus Types 1b and 2: Viral Spread and Molecular Neuropathology. J Comp Pathol 2008; 138:72-85. [DOI: 10.1016/j.jcpa.2007.10.006] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2007] [Accepted: 10/27/2007] [Indexed: 11/24/2022]
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Willis CL, Garwood CJ, Ray DE. A size selective vascular barrier in the rat area postrema formed by perivascular macrophages and the extracellular matrix. Neuroscience 2007; 150:498-509. [PMID: 17945430 DOI: 10.1016/j.neuroscience.2007.09.023] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2007] [Revised: 08/23/2007] [Accepted: 10/03/2007] [Indexed: 10/22/2022]
Abstract
The fenestrated microvasculature of the area postrema shows a less restrictive blood-brain barrier than is found in other areas of the CNS. We have studied the expression and relationship of vascular endothelial tight junctional proteins, astrocytes, macrophages, and the extracellular matrix with the extravasation of fluorescently tagged dextrans and sodium fluorescein in the rat area postrema. Glial fibrillary acidic protein (GFAP) -positive astrocytes were present within the area postrema which was surrounded by a dense zone of highly GFAP-reactive astrocytes. Expression of the tight junction proteins claudin-5, -12 and occludin was absent, although diffuse cytoplasmic claudin-1 immunoreactivity was present. The extracellular matrix of the endothelium showed two non-fused thickened layers of laminin immunoreactivity. CD163 and CD169 immunoreactive perivascular macrophages were located within lacunae between these two laminin layers. Fluorescently tagged dextrans (10-70 kDa) passed from the vasculature but were retained between the inner and outer laminin walls and rapidly sequestered by the perivascular CD163 and CD169 macrophages. Three-kilodalton dextran diffused into the parenchyma, but was retained within the boundary of the area postrema at the interface with the highly reactive GFAP-astrocytes, while sodium fluorescein (0.3 kDa) passed from the area postrema into surrounding CNS areas. Our observations suggest that despite the absence of a tight blood-brain barrier, a size selective barrier restricting the movement of blood solutes into the parenchyma is present in the area postrema. We suggest that the rapid uptake by CD163 and CD169 macrophages together with the non-fused laminin immunoreactive layers of the extracellular matrix plays a size selective role in restricting movement of serum proteins and other blood borne macromolecules over 10 kDa in to the area postrema.
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Affiliation(s)
- C L Willis
- Medical Research Council Applied Neuroscience Group, School of Biomedical Sciences, Queen's Medical Centre, University of Nottingham NG7 2UH, UK.
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Willis CL, Taylor GL, Ray DE. Microvascular P-glycoprotein expression at the blood-brain barrier following focal astrocyte loss and at the fenestrated vasculature of the area postrema. Brain Res 2007; 1173:126-36. [PMID: 17803981 DOI: 10.1016/j.brainres.2007.07.074] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2007] [Revised: 07/28/2007] [Accepted: 07/31/2007] [Indexed: 02/05/2023]
Abstract
The multidrug transporter, P-glycoprotein, expressed at the blood-brain barrier is thought to be important for limiting access of toxic agents to the brain, but its relationship to astrocyte expression is unclear. We have studied P-glycoprotein expression in the inferior colliculus after a temporary loss of blood-brain barrier integrity following chemically induced astrocyte loss and at the fenestrated vascular endothelium of the area postrema. Male Fisher F344 rats given 3-chloropropanediol showed astrocyte loss from 12 to 24 h until the lesion was repopulated 8-28 days later. In non-dosed tissue, P-glycoprotein expression was seen the entire length of platelet endothelial cell adhesion molecule immunoreactive vessels. Within 6 h of dosing, a significant (p<0.05) reduction in the total length of P-glycoprotein immunoreactive vasculature was evident. By 48 h, P-glycoprotein immunoreactivity was heavily fragmented. The total length of P-glycoprotein immunoreactive vessels became minimal at 4 days (p<0.001) but was still present in many vessels. From 6 to 28 days, P-glycoprotein immunoreactivity returned across the inferior colliculus, in parallel with astrocytic repopulation of the lesion, and by 28 days resembled that seen in control tissue. The area postrema showed GFAP immunoreactive astrocytes but which made limited contact with the vasculature, while the platelet endothelial cell adhesion molecule immunoreactive vasculature showed no expression of P-glycoprotein. These findings provide evidence supporting a link between GFAP-astrocyte and P-glycoprotein expression in the mature brain vasculature in vivo.
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Affiliation(s)
- Colin L Willis
- MRC Applied Neuroscience Group, School of Biomedical Sciences, Queen's Medical Centre, University of Nottingham NG7 2UH, UK.
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25
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Greis A, Murgott J, Rafalzik S, Gerstberger R, Hübschle T, Roth J. Characterization of the febrile response induced by fibroblast-stimulating lipopeptide-1 in guinea pigs. Am J Physiol Regul Integr Comp Physiol 2007; 293:R152-61. [PMID: 17491112 DOI: 10.1152/ajpregu.00182.2007] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Recently, it has been shown that the Toll-like receptors-2 and -6 agonist fibroblast-stimulating lipopeptide-1 (FSL-1) have the capacity to induce fever and sickness behavior in rats. Since the mechanisms of the fever-inducing effects of FSL-1 are still unknown, we tested the pyrogenic properties of FSL-1 in guinea pigs and assessed a role for TNF-alpha and prostaglandins in the manifestation of the febrile response to this substance. Intra-arterial and intraperitoneal injections of FSL-1 caused dose-dependent fevers that coincided with elevated plasma levels of TNF and IL-6, the intraperitoneal route of administration being more effective than the intra-arterial route. Intra-arterial or intraperitoneal injection of a soluble form of the TNF type 1 receptor, referred to as TNF binding protein (TNFbp), together with FSL-1, completely neutralized FSL-1-induced circulating TNF and reduced fever and circulating IL-6. Intra-arterial or intraperitoneal injection of the nonselective cyclooxygenase (COX)-inhibitor diclofenac depressed fever and FSL-1-induced elevations of circulating PGE2. Circulating TNF and IL-6, however, remained unimpaired by treatment with diclofenac. In conclusion, FSL-1-induced fever in guinea pigs depends, in shape and duration, on the route of administration and is, to a high degree, mediated by pyrogenic cytokines and COX products.
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Affiliation(s)
- Andrea Greis
- Institut für Veterinär-Physiologie, Justus-Liebig-Universität Giessen, Frankfurter Strasse 100, D-35392 Giessen, Germany
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