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Eskilsson A, Shionoya K, Engblom D, Blomqvist A. Fever During Localized Inflammation in Mice Is Elicited by a Humoral Pathway and Depends on Brain Endothelial Interleukin-1 and Interleukin-6 Signaling and Central EP 3 Receptors. J Neurosci 2021; 41:5206-5218. [PMID: 33941650 PMCID: PMC8211540 DOI: 10.1523/jneurosci.0313-21.2021] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 04/01/2021] [Accepted: 04/26/2021] [Indexed: 02/02/2023] Open
Abstract
We examined the signaling route for fever during localized inflammation in male and female mice, elicited by casein injection into a preformed air pouch. The localized inflammation gave rise to high concentrations of prostaglandins of the E species (PGE2) and cytokines in the air pouch and elevated levels of these inflammatory mediators in plasma. There were also elevated levels of PGE2 in the cerebrospinal fluid, although there was little evidence for PGE2 synthesis in the brain. Global deletion of the PGE2 prostaglandin E receptor 3 (EP3) abolished the febrile response as did deletion of the EP3 receptor in neural cells, whereas its deletion on peripheral nerves had no effect, implying that PGE2 action on this receptor in the CNS elicited the fever. Global deletion of the interleukin-1 receptor type 1 (IL-1R1) also abolished the febrile response, whereas its deletion on neural cells or peripheral nerves had no effect. However, deletion of the IL-1R1 on brain endothelial cells, as well as deletion of the interleukin-6 receptor α on these cells, attenuated the febrile response. In contrast, deletion of the PGE2 synthesizing enzymes cyclooxygenase-2 and microsomal prostaglandin synthase-1 in brain endothelial cells, known to attenuate fever evoked by systemic inflammation, had no effect. We conclude that fever during localized inflammation is not mediated by neural signaling from the inflamed site, as previously suggested, but is dependent on humoral signaling that involves interleukin actions on brain endothelial cells, probably facilitating PGE2 entry into the brain from the circulation and hence representing a mechanism distinct from that at work during systemic inflammation.
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Affiliation(s)
- Anna Eskilsson
- Division of Neurobiology and Center for Social and Affective Neuroscience, Department of Biomedical and Clinical Sciences, Linköping University, S-58185 Linköping, Sweden
| | - Kiseko Shionoya
- Division of Neurobiology and Center for Social and Affective Neuroscience, Department of Biomedical and Clinical Sciences, Linköping University, S-58185 Linköping, Sweden
| | - David Engblom
- Division of Neurobiology and Center for Social and Affective Neuroscience, Department of Biomedical and Clinical Sciences, Linköping University, S-58185 Linköping, Sweden
| | - Anders Blomqvist
- Division of Neurobiology and Center for Social and Affective Neuroscience, Department of Biomedical and Clinical Sciences, Linköping University, S-58185 Linköping, Sweden
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Henkel J, Coleman CD, Schraplau A, Jöhrens K, Weiss TS, Jonas W, Schürmann A, Püschel GP. Augmented liver inflammation in a microsomal prostaglandin E synthase 1 (mPGES-1)-deficient diet-induced mouse NASH model. Sci Rep 2018; 8:16127. [PMID: 30382148 PMCID: PMC6208405 DOI: 10.1038/s41598-018-34633-y] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Accepted: 10/22/2018] [Indexed: 12/11/2022] Open
Abstract
In a subset of patients, non-alcoholic fatty liver disease (NAFLD) is complicated by cell death and inflammation resulting in non-alcoholic steatohepatitis (NASH), which may progress to fibrosis and subsequent organ failure. Apart from cytokines, prostaglandins, in particular prostaglandin E2 (PGE2), play a pivotal role during inflammatory processes. Expression of the key enzymes of PGE2 synthesis, cyclooxygenase 2 and microsomal PGE synthase 1 (mPGES-1), was increased in human NASH livers in comparison to controls and correlated with the NASH activity score. Both enzymes were also induced in NASH-diet-fed wild-type mice, resulting in an increase in hepatic PGE2 concentration that was completely abrogated in mPGES-1-deficient mice. PGE2 is known to inhibit TNF-α synthesis in macrophages. A strong infiltration of monocyte-derived macrophages was observed in NASH-diet-fed mice, which was accompanied with an increase in hepatic TNF-α expression. Due to the impaired PGE2 production, TNF-α expression increased much more in livers of mPGES-1-deficient mice or in the peritoneal macrophages of these mice. The increased levels of TNF-α resulted in an enhanced IL-1β production, primarily in hepatocytes, and augmented hepatocyte apoptosis. In conclusion, attenuation of PGE2 production by mPGES-1 ablation enhanced the TNF-α-triggered inflammatory response and hepatocyte apoptosis in diet-induced NASH.
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Affiliation(s)
- Janin Henkel
- University of Potsdam, Institute of Nutritional Science, Department of Nutritional Biochemistry, Nuthetal, Germany.
| | - Charles Dominic Coleman
- University of Potsdam, Institute of Nutritional Science, Department of Nutritional Biochemistry, Nuthetal, Germany
| | - Anne Schraplau
- University of Potsdam, Institute of Nutritional Science, Department of Nutritional Biochemistry, Nuthetal, Germany
| | - Korinna Jöhrens
- Charité University Hospital Berlin, Institute of Pathology, Berlin, Germany
| | - Thomas Siegfried Weiss
- University Hospital Regensburg, University Children Hospital (KUNO) Regensburg, Regensburg, Germany
| | - Wenke Jonas
- German Institute of Human Nutrition, Department of Experimental Diabetology, Nuthetal, Germany.,German Center for Diabetes Research (DZD), München-Neuherberg, Germany
| | - Annette Schürmann
- German Institute of Human Nutrition, Department of Experimental Diabetology, Nuthetal, Germany.,German Center for Diabetes Research (DZD), München-Neuherberg, Germany
| | - Gerhard Paul Püschel
- University of Potsdam, Institute of Nutritional Science, Department of Nutritional Biochemistry, Nuthetal, Germany
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Abstract
Fever is a common symptom of infectious and inflammatory disease. It is well-established that prostaglandin E2 is the final mediator of fever, which by binding to its EP3 receptor subtype in the preoptic hypothalamus initiates thermogenesis. Here, we review the different hypotheses on how the presence of peripherally released pyrogenic substances can be signaled to the brain to elicit fever. We conclude that there is unequivocal evidence for a humoral signaling pathway by which proinflammatory cytokines, through their binding to receptors on brain endothelial cells, evoke fever by eliciting prostaglandin E2 synthesis in these cells. The evidence for a role for other signaling routes for fever, such as signaling via circumventricular organs and peripheral nerves, as well as transfer into the brain of peripherally synthesized prostaglandin E2 are yet far from conclusive. We also review the efferent limb of the pyrogenic pathways. We conclude that it is well established that prostaglandin E2 binding in the preoptic hypothalamus produces fever by disinhibition of presympathetic neurons in the brain stem, but there is yet little understanding of the mechanisms by which factors such as nutritional status and ambient temperature shape the response to the peripheral immune challenge.
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Affiliation(s)
- Anders Blomqvist
- Department of Clinical and Experimental Medicine, Faculty of Medicine and Health, Linköping University, Linköping, Sweden
| | - David Engblom
- Department of Clinical and Experimental Medicine, Faculty of Medicine and Health, Linköping University, Linköping, Sweden
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Mirrasekhian E, Nilsson JLÅ, Shionoya K, Blomgren A, Zygmunt PM, Engblom D, Högestätt ED, Blomqvist A. The antipyretic effect of paracetamol occurs independent of transient receptor potential ankyrin 1-mediated hypothermia and is associated with prostaglandin inhibition in the brain. FASEB J 2018; 32:5751-5759. [PMID: 29738273 DOI: 10.1096/fj.201800272r] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The mode of action of paracetamol (acetaminophen), which is widely used for treating pain and fever, has remained obscure, but may involve several distinct mechanisms, including cyclooxygenase inhibition and transient receptor potential ankyrin 1 (TRPA1) channel activation, the latter being recently associated with paracetamol's propensity to elicit hypothermia at higher doses. Here, we examined whether the antipyretic effect of paracetamol was due to TRPA1 activation or cyclooxygenase inhibition. Treatment of wild-type and TRPA1 knockout mice rendered febrile by immune challenge with LPS with a dose of paracetamol that did not produce hypothermia (150 mg/kg) but is known to be analgetic, abolished fever in both genotypes. Paracetamol completely suppressed the LPS-induced elevation of prostaglandin E2 in the brain and also reduced the levels of several other prostanoids. The hypothermia induced by paracetamol was abolished in mice treated with the electrophile-scavenger N-acetyl cysteine. We conclude that paracetamol's antipyretic effect in mice is dependent on inhibition of cyclooxygenase activity, including the formation of pyrogenic prostaglandin E2, whereas paracetamol-induced hypothermia likely is mediated by the activation of TRPA1 by electrophilic metabolites of paracetamol, similar to its analgesic effect in some experimental paradigms.-Mirrasekhian, E., Nilsson, J. L. Å., Shionoya, K., Blomgren, A., Zygmunt, P. M., Engblom, D., Högestätt, E. D., Blomqvist, A. The antipyretic effect of paracetamol occurs independent of transient receptor potential ankyrin 1-mediated hypothermia and is associated with prostaglandin inhibition in the brain.
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Affiliation(s)
- Elahe Mirrasekhian
- Division of Neurobiology, Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden; and
| | - Johan L Å Nilsson
- Division of Clinical Chemistry and Pharmacology, Department of Laboratory Medicine, Lund University, Lund, Sweden
| | - Kiseko Shionoya
- Division of Neurobiology, Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden; and
| | - Anders Blomgren
- Division of Clinical Chemistry and Pharmacology, Department of Laboratory Medicine, Lund University, Lund, Sweden
| | - Peter M Zygmunt
- Division of Clinical Chemistry and Pharmacology, Department of Laboratory Medicine, Lund University, Lund, Sweden
| | - David Engblom
- Division of Neurobiology, Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden; and
| | - Edward D Högestätt
- Division of Clinical Chemistry and Pharmacology, Department of Laboratory Medicine, Lund University, Lund, Sweden
| | - Anders Blomqvist
- Division of Neurobiology, Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden; and
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Matsuwaki T, Shionoya K, Ihnatko R, Eskilsson A, Kakuta S, Dufour S, Schwaninger M, Waisman A, Müller W, Pinteaux E, Engblom D, Blomqvist A. Involvement of interleukin-1 type 1 receptors in lipopolysaccharide-induced sickness responses. Brain Behav Immun 2017; 66:165-176. [PMID: 28655587 DOI: 10.1016/j.bbi.2017.06.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Revised: 06/15/2017] [Accepted: 06/23/2017] [Indexed: 12/17/2022] Open
Abstract
Sickness responses to lipopolysaccharide (LPS) were examined in mice with deletion of the interleukin (IL)-1 type 1 receptor (IL-1R1). IL-1R1 knockout (KO) mice displayed intact anorexia and HPA-axis activation to intraperitoneally injected LPS (anorexia: 10 or 120µg/kg; HPA-axis: 120µg/kg), but showed attenuated but not extinguished fever (120µg/kg). Brain PGE2 synthesis was attenuated, but Cox-2 induction remained intact. Neither the tumor necrosis factor-α (TNFα) inhibitor etanercept nor the IL-6 receptor antibody tocilizumab abolished the LPS induced fever in IL-1R1 KO mice. Deletion of IL-1R1 specifically in brain endothelial cells attenuated the LPS induced fever, but only during the late, 3rd phase of fever, whereas deletion of IL-1R1 on neural cells or on peripheral nerves had little or no effect on the febrile response. We conclude that while IL-1 signaling is not critical for LPS induced anorexia or stress hormone release, IL-1R1, expressed on brain endothelial cells, contributes to the febrile response to LPS. However, also in the absence of IL-1R1, LPS evokes a febrile response, although this is attenuated. This remaining fever seems not to be mediated by IL-6 receptors or TNFα, but by some yet unidentified pyrogenic factor.
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Affiliation(s)
- Takashi Matsuwaki
- Department of Clinical and Experimental Medicine, Linköping University, 581 85 Linköping, Sweden; Department of Veterinary Physiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Kiseko Shionoya
- Department of Clinical and Experimental Medicine, Linköping University, 581 85 Linköping, Sweden
| | - Robert Ihnatko
- Department of Clinical and Experimental Medicine, Linköping University, 581 85 Linköping, Sweden
| | - Anna Eskilsson
- Department of Clinical and Experimental Medicine, Linköping University, 581 85 Linköping, Sweden
| | - Shigeru Kakuta
- Department of Biomedical Science, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | | | - Markus Schwaninger
- Institute of Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, 23538 Lübeck, Germany
| | - Ari Waisman
- Institute for Molecular Medicine, University Medical Center of the Johannes Gutenberg University Mainz, 55131 Mainz, Germany
| | - Werner Müller
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PT, United Kingdom
| | - Emmanuel Pinteaux
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PT, United Kingdom
| | - David Engblom
- Department of Clinical and Experimental Medicine, Linköping University, 581 85 Linköping, Sweden
| | - Anders Blomqvist
- Department of Clinical and Experimental Medicine, Linköping University, 581 85 Linköping, Sweden.
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Immune-Induced Fever Is Dependent on Local But Not Generalized Prostaglandin E 2 Synthesis in the Brain. J Neurosci 2017; 37:5035-5044. [PMID: 28438967 DOI: 10.1523/jneurosci.3846-16.2017] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Revised: 04/13/2017] [Accepted: 04/18/2017] [Indexed: 11/21/2022] Open
Abstract
Fever occurs upon binding of prostaglandin E2 (PGE2) to EP3 receptors in the median preoptic nucleus of the hypothalamus, but the origin of the pyrogenic PGE2 has not been clearly determined. Here, using mice of both sexes, we examined the role of local versus generalized PGE2 production in the brain for the febrile response. In wild-type mice and in mice with genetic deletion of the prostaglandin synthesizing enzyme cyclooxygenase-2 in the brain endothelium, generated with an inducible CreERT2 under the Slco1c1 promoter, PGE2 levels in the CSF were only weakly related to the magnitude of the febrile response, whereas the PGE2 synthesizing capacity in the hypothalamus, as reflected in the levels of cyclooxygenase-2 mRNA, showed strong correlation with the immune-induced fever. Histological analysis showed that the deletion of cyclooxygenase-2 in brain endothelial cells occurred preferentially in small- and medium-sized vessels deep in the brain parenchyma, such as in the hypothalamus, whereas larger vessels, and particularly those close to the neocortical surface and in the meninges, were left unaffected, hence leaving PGE2 synthesis largely intact in major parts of the brain while significantly reducing it in the region critical for the febrile response. Furthermore, injection of a virus vector expressing microsomal prostaglandin E synthase-1 (mPGES-1) into the median preoptic nucleus of fever-refractive mPGES-1 knock-out mice, resulted in a temperature elevation in response to LPS. We conclude that the febrile response is dependent on local release of PGE2 onto its target neurons and not on the overall PGE2 production in the brain.SIGNIFICANCE STATEMENT By using mice with selective deletion of prostaglandin synthesis in brain endothelial cells, we demonstrate that local prostaglandin E2 (PGE2) production in deep brain areas, such as the hypothalamus, which is the site of thermoregulatory neurons, is critical for the febrile response to peripheral inflammation. In contrast, PGE2 production in other brain areas and the overall PGE2 level in the brain do not influence the febrile response. Furthermore, partly restoring the PGE2 synthesizing capacity in the anterior hypothalamus of mice lacking such capacity with a lentiviral vector resulted in a temperature elevation in response to LPS. These data imply that the febrile response is dependent on the local release of PGE2 onto its target neurons, possibly by a paracrine mechanism.
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7
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Nilsson A, Elander L, Hallbeck M, Örtegren Kugelberg U, Engblom D, Blomqvist A. The involvement of prostaglandin E 2 in interleukin-1β evoked anorexia is strain dependent. Brain Behav Immun 2017; 60:27-31. [PMID: 27375005 DOI: 10.1016/j.bbi.2016.06.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Revised: 06/15/2016] [Accepted: 06/28/2016] [Indexed: 01/08/2023] Open
Abstract
From experiments in mice in which the prostaglandin E2 (PGE2) synthesizing enzyme mPGES-1 was genetically deleted, as well as from experiments in which PGE2 was injected directly into the brain, PGE2 has been implicated as a mediator of inflammatory induced anorexia. Here we aimed at examining which PGE2 receptor (EP1-4) that was critical for the anorexic response to peripherally injected interleukin-1β (IL-1β). However, deletion of neither EP receptor in mice, either globally (for EP1, EP2, and EP3) or selectively in the nervous system (EP4), had any effect on the IL-1β induced anorexia. Because these mice were all on a C57BL/6 background, whereas previous observations demonstrating a role for induced PGE2 in IL-1β evoked anorexia had been carried out on mice on a DBA/1 background, we examined the anorexic response to IL-1β in mice with deletion of mPGES-1 on a C57BL/6 background and a DBA/1 background, respectively. We confirmed previous findings that mPGES-1 knock-out mice on a DBA/1 background displayed attenuated anorexia to IL-1β; however, mice on a C57BL/6 background showed the same profound anorexia as wild type mice when carrying deletion of mPGES-1, while displaying almost normal food intake after pretreatment with a cyclooxygenase-2 inhibitor. We conclude that the involvement of induced PGE2 in IL-1β evoked anorexia is strain dependent and we suggest that different routes that probably involve distinct prostanoids exist by which inflammatory stimuli may evoke an anorexic response and that these routes may be of different importance in different strains of mice.
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Affiliation(s)
- Anna Nilsson
- Division of Cell Biology, Department of Clinical and Experimental Medicine, Linköping University, S-581 85 Linköping, Sweden
| | - Louise Elander
- Division of Anesthesiology and Intensive Care, Department of Medical and Health Sciences, Linköping University, S-581 85 Linköping, Sweden
| | - Martin Hallbeck
- Division of Experimental Pathology, Department of Clinical and Experimental Medicine, Linköping University, S-581 85 Linköping, Sweden
| | - Unn Örtegren Kugelberg
- Division of Cell Biology, Department of Clinical and Experimental Medicine, Linköping University, S-581 85 Linköping, Sweden
| | - David Engblom
- Division of Cell Biology, Department of Clinical and Experimental Medicine, Linköping University, S-581 85 Linköping, Sweden
| | - Anders Blomqvist
- Division of Cell Biology, Department of Clinical and Experimental Medicine, Linköping University, S-581 85 Linköping, Sweden.
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8
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Evans SS, Repasky EA, Fisher DT. Fever and the thermal regulation of immunity: the immune system feels the heat. Nat Rev Immunol 2015; 15:335-49. [PMID: 25976513 PMCID: PMC4786079 DOI: 10.1038/nri3843] [Citation(s) in RCA: 626] [Impact Index Per Article: 69.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Fever is a cardinal response to infection that has been conserved in warm-blooded and cold-blooded vertebrates for more than 600 million years of evolution. The fever response is executed by integrated physiological and neuronal circuitry and confers a survival benefit during infection. In this Review, we discuss our current understanding of how the inflammatory cues delivered by the thermal element of fever stimulate innate and adaptive immune responses. We further highlight the unexpected multiplicity of roles of the pyrogenic cytokine interleukin-6 (IL-6), both during fever induction and during the mobilization of lymphocytes to the lymphoid organs that are the staging ground for immune defence. We also discuss the emerging evidence suggesting that the adrenergic signalling pathways associated with thermogenesis shape immune cell function.
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Affiliation(s)
- Sharon S Evans
- Department of Immunology, Roswell Park Cancer Institute, Elm &Carlton Streets, Buffalo, New York 14263, USA
| | - Elizabeth A Repasky
- Department of Immunology, Roswell Park Cancer Institute, Elm &Carlton Streets, Buffalo, New York 14263, USA
| | - Daniel T Fisher
- Department of Immunology, Roswell Park Cancer Institute, Elm &Carlton Streets, Buffalo, New York 14263, USA
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François A, Terro F, Quellard N, Fernandez B, Chassaing D, Janet T, Rioux Bilan A, Paccalin M, Page G. Impairment of autophagy in the central nervous system during lipopolysaccharide-induced inflammatory stress in mice. Mol Brain 2014; 7:56. [PMID: 25169902 PMCID: PMC4237961 DOI: 10.1186/s13041-014-0056-z] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Accepted: 07/29/2014] [Indexed: 12/15/2022] Open
Abstract
Background Current evidence suggests a central role for autophagy in many neurodegenerative diseases including Alzheimer’s disease, Huntington’s disease, Parkinson’s disease and amyotrophic lateral sclerosis. Furthermore, it is well admitted that inflammation contributes to the progression of these diseases. Interestingly, crosstalks between autophagy and inflammation have been reported in vitro and at the peripheral level such as in Crohn’s disease. However, the impact of systemic inflammation on autophagic components in the brain remains to be documented. Therefore, this study monitored autophagy markers after acute and chronic lipopolysaccharide (LPS)-induced inflammatory stress in mice. Results We showed that acute inflammation, 24 h post-intraperitoneal 10 mg/kg LPS, substantially increased cytokine production (Interleukin(IL)-1β, Tumor necrosis factor (TNF)-α and IL-6), decreased the levels of autophagy markers (Beclin-1, p62 and LC3 II) and reduced p70S6K activation in cortex and hippocampus. In hippocampus, IL-1β levels and LC3 II expression were positively and highly correlated and a negative correlation was noted between TNF-α levels and p70S6K activation. Chronic inflammation by injection of 0.5 mg/kg LPS every three days during three months led to a moderate IL-1β production and decreased TNF-α levels. Interestingly, Beclin-1 and LC3 II levels decreased while those of p62 increased. Cortical IL-1β levels positively correlated with Beclin-1 and LC3 II and on the contrary inversely correlated with p62. Conclusion The present study is the first showing links between IL-1β-mediated inflammation and autophagy in the brain. It could open to new therapeutic strategies in brain diseases where regulation impairment of inflammation and autophagy progress with the severity of diseases.
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Affiliation(s)
- Arnaud François
- EA3808 molecular Targets and Therapeutic of Alzheimer's disease, University of Poitiers, Poitiers F-86073, France.
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10
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Modeling the inflammatory response in the hypothalamus ensuing heat stroke: iterative cycle of model calibration, identifiability analysis, experimental design and data collection. Math Biosci 2014; 260:35-46. [PMID: 25119202 DOI: 10.1016/j.mbs.2014.07.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Revised: 07/30/2014] [Accepted: 07/31/2014] [Indexed: 01/06/2023]
Abstract
Heat Stroke (HS) is a life-threatening illness caused by prolonged exposure to heat that causes severe hyperthermia and nervous system abnormalities. The long term consequences of HS are poorly understood and deeper insight is required to find possible treatment strategies. Elevated pro- and anti-inflammatory cytokines during HS recovery suggest to play a major role in the immune response. In this study, we developed a mathematical model to understand the interactions and dynamics of cytokines in the hypothalamus, the main thermoregulatory center in the brain. Uncertainty and identifiability analysis of the calibrated model parameters revealed non-identifiable parameters due to the limited amount of data. To overcome the lack of identifiability of the parameters, an iterative cycle of optimal experimental design, data collection, re-calibration and model reduction was applied and further informative experiments were suggested. Additionally, a new method of approximating the prior distribution of the parameters for Bayesian optimal experimental design based on the profile likelihood is presented.
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11
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Hamzic N, Tang Y, Eskilsson A, Kugelberg U, Ruud J, Jönsson JI, Blomqvist A, Nilsberth C. Interleukin-6 primarily produced by non-hematopoietic cells mediates the lipopolysaccharide-induced febrile response. Brain Behav Immun 2013; 33:123-30. [PMID: 23827828 DOI: 10.1016/j.bbi.2013.06.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2013] [Revised: 06/15/2013] [Accepted: 06/25/2013] [Indexed: 02/07/2023] Open
Abstract
Interleukin-6 (IL-6) is critical for the lipopolysaccharide (LPS)-induced febrile response. However, the exact source(s) of IL-6 involved in regulating the LPS-elicited fever is still to be identified. One known source of IL-6 is hematopoietic cells, such as monocytes. To clarify the contribution of hematopoietically derived IL-6 to fever, we created chimeric mice expressing IL-6 selectively either in cells of hematopoietic or, conversely, in cells of non-hematopoietic origin. This was performed by extinguishing hematopoietic cells in wild-type (WT) or IL-6 knockout (IL-6 KO) mice by whole-body irradiation and transplanting them with new stem cells. Mice on a WT background but lacking IL-6 in hematopoietic cells displayed normal fever to LPS and were found to have similar levels of IL-6 protein in the cerebrospinal fluid (CSF) and in plasma and of IL-6 mRNA in the brain as WT mice. In contrast, mice on an IL-6 KO background, but with intact IL-6 production in cells of hematopoietic origin, only showed a minor elevation of the body temperature after peripheral LPS injection. While they displayed significantly elevated levels of IL-6 both in plasma and CSF compared with control mice, the increase was modest compared with that seen in LPS injected mice on a WT background, the latter being approximately 20 times larger in magnitude. These results suggest that IL-6 of non-hematopoietic origin is the main source of IL-6 in LPS-induced fever, and that IL-6 produced by hematopoietic cells only plays a minor role.
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Affiliation(s)
- Namik Hamzic
- Linköping University, Faculty of Health Sciences, Department of Clinical and Experimental Medicine, Division of Cell Biology, SE-581 85 Linköping, Sweden
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12
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Engström Ruud L, Wilhelms DB, Eskilsson A, Vasilache AM, Elander L, Engblom D, Blomqvist A. Acetaminophen reduces lipopolysaccharide-induced fever by inhibiting cyclooxygenase-2. Neuropharmacology 2013; 71:124-9. [DOI: 10.1016/j.neuropharm.2013.03.012] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2012] [Revised: 03/11/2013] [Accepted: 03/17/2013] [Indexed: 02/02/2023]
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13
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Vasilache AM, Kugelberg U, Blomqvist A, Nilsberth C. Minor changes in gene expression in the mouse preoptic hypothalamic region by inflammation-induced prostaglandin E2. J Neuroendocrinol 2013; 25:635-43. [PMID: 23631667 DOI: 10.1111/jne.12044] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2013] [Revised: 04/14/2013] [Accepted: 04/26/2013] [Indexed: 11/30/2022]
Abstract
We investigated to what extent inflammation-induced prostaglandin E2 (PGE2 ) regulates gene expression in the central nervous system. Wild-type mice and mice with deletion of the gene encoding microsomal prostaglandin E synthase-1 (mPGES-1), which cannot produce inflammation-induced PGE2 , were subjected to peripheral injection of bacterial wall lipopolysaccharide (LPS) and killed after 5 h. The median and medial preoptic nuclei, which are rich in prostaglandin E receptors, were isolated by laser capture microdissection (LCM), and subjected to whole genome microarray analysis. Although the immune stimulus induced robust transcriptional changes in the brain, as seen by a quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) on selected genes, only small PGE2 -dependent gene expression changes were observed in the gene array analysis and, for only two genes, a pronounced differential expression between LPS-treated wild-type and mPGES-1 knockout mice could be verified by qRT-PCR. These were Hspa1a and Hspa1b, encoding heat shock proteins, which showed a two- to three-fold higher expression in wild-type mice than in knockout mice after immune challenge. However, the induced expression of these genes was found to be secondary to increased body temperature because they were induced also by cage exchange stress, which did not elicit PGE2 synthesis, and thus were not induced per se by PGE2 -elicited transcriptional events. Our findings suggest that inflammation-induced PGE2 has little effect on gene expression in the preoptic region, and that centrally elicited disease symptoms, although PGE2 -dependent, occur as a result of regulation of neuronal excitability that is a consequence of intracellular, transcriptional-independent signalling cascades. Our findings also imply that the profound changes in gene expression in the brain that are elicited by peripheral inflammation occur independently of PGE2 via a yet unidentified mechanism.
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Affiliation(s)
- A M Vasilache
- Division of Cell Biology, Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Linköping University, S-581 85 Linköping, Sweden
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Hamzic N, Blomqvist A, Nilsberth C. Immune-induced expression of lipocalin-2 in brain endothelial cells: relationship with interleukin-6, cyclooxygenase-2 and the febrile response. J Neuroendocrinol 2013; 25:271-80. [PMID: 23046379 DOI: 10.1111/jne.12000] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2012] [Revised: 09/18/2012] [Accepted: 10/01/2012] [Indexed: 12/12/2022]
Abstract
Interleukin (IL)-6 is critical for the febrile response to peripheral immune challenge. However, the mechanism by which IL-6 enables fever is still unknown. To characterise the IL-6-dependent fever generating pathway, we used microarray analysis to identify differentially expressed genes in the brain of lipopolysaccharide (LPS)-treated IL-6 wild-type and knockout mice. Mice lacking IL-6 displayed a two-fold lower expression of the lipocalin-2 gene (lcn2), and this difference was confirmed by real-time reverse transcriptase-polymerase chain reaction. Conversely, the induction of lipocalin-2 protein was observed in brain vascular cells following i.p. administration of recombinant IL-6, suggesting a direct relationship between IL-6 and lipocalin-2. Immunohistochemical analysis also revealed that LPS-induced lipocalin-2 is expressed by brain endothelial cells and is partly co-localised with cyclooxygenase-2 (Cox-2), the rate-limiting enzyme for the production of inflammatory induced prostaglandin E(2) (PGE(2) ), which is the key mediator of fever. The direct role of lipocalin-2 in fever was examined in LPS-challenged lipocalin-2 knockout mice. In both male and female mice, normal fever responses were observed at near-thermoneutral conditions (29-30 °C) but when recorded at normal room temperature (19-20 °C), the body temperature of lipocalin-2 knockout female mice displayed an attenuated fever response compared to their wild-type littermates. This difference was reflected in significantly attenuated mRNA expression of Cox-2 in the brain of lipocalin-2 knockout female mice, but not of male mice, following challenge with peripheral LPS. Our findings suggest that IL-6 influences the expression of lipocalin-2, which in turn may be involved in the control of the formation of Cox-2, and hence central PGE(2) -production. We have thus identified lipocalin-2 as a new factor in the pathway of inflammatory IL-6 signalling. However, the effect of lipocalin-2 on fever is small, being sex-dependent and ambient temperature-specific, and thus lipocalin-2 cannot be considered as a major mediator of the IL-6-dependent fever generating pathway.
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Affiliation(s)
- N Hamzic
- Division of Cell Biology, Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Linköping University, Linköping, Sweden
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Engström L, Ruud J, Eskilsson A, Larsson A, Mackerlova L, Kugelberg U, Qian H, Vasilache AM, Larsson P, Engblom D, Sigvardsson M, Jönsson JI, Blomqvist A. Lipopolysaccharide-induced fever depends on prostaglandin E2 production specifically in brain endothelial cells. Endocrinology 2012; 153:4849-61. [PMID: 22872578 DOI: 10.1210/en.2012-1375] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Immune-induced prostaglandin E2 (PGE2) synthesis is critical for fever and other centrally elicited disease symptoms. The production of PGE2 depends on cyclooxygenase-2 and microsomal prostaglandin E synthase-1 (mPGES-1), but the identity of the cells involved has been a matter of controversy. We generated mice expressing mPGES-1 either in cells of hematopoietic or nonhematopoietic origin. Mice lacking mPGES-1 in hematopoietic cells displayed an intact febrile response to lipopolysaccharide, associated with elevated levels of PGE2 in the cerebrospinal fluid. In contrast, mice that expressed mPGES-1 only in hematopoietic cells, although displaying elevated PGE2 levels in plasma but not in the cerebrospinal fluid, showed no febrile response to lipopolysaccharide, thus pointing to the critical role of brain-derived PGE2 for fever. Immunohistochemical stainings showed that induced cyclooxygenase-2 expression in the brain exclusively occurred in endothelial cells, and quantitative PCR analysis on brain cells isolated by flow cytometry demonstrated that mPGES-1 is induced in endothelial cells and not in vascular wall macrophages. Similar analysis on liver cells showed induced expression in macrophages and not in endothelial cells, pointing at the distinct role for brain endothelial cells in PGE2 synthesis. These results identify the brain endothelial cells as the PGE2-producing cells critical for immune-induced fever.
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Affiliation(s)
- Linda Engström
- Department of Clinical and Experimental Medicine, Division of Radiation Physics, Faculty of Health Sciences, Linköping University, S-581 85 Linköping, Sweden
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Damm J, Luheshi GN, Gerstberger R, Roth J, Rummel C. Spatiotemporal nuclear factor interleukin-6 expression in the rat brain during lipopolysaccharide-induced fever is linked to sustained hypothalamic inflammatory target gene induction. J Comp Neurol 2011; 519:480-505. [PMID: 21192080 DOI: 10.1002/cne.22529] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Rats injected with lipopolysaccharide (LPS) show brain-controlled sickness symptoms, including fever. In these animals, early genomic activation of brain cells was previously monitored by immunohistochemical detection of transcription factors such as nuclear factor (NF)-κB or signal transducer and activator of transcription (STAT)3 and was linked to the initiation or maintenance of the febrile response. To investigate whether NF-IL6 might be another important transcription factor implicated in this kind of immune-to-brain signaling, rats were injected with LPS (100 μg/kg, intraperitoneally) or phosphate-buffered saline, and brains were analyzed by immunohistochemistry, real-time PCR, or Western blot 4, 6, 8, and 10 hours later. Moderate to strong LPS-induced nuclear NF-IL6 immunoreactivity (IR) occurred in a time-dependent manner within circumventricular organs, namely, the vascular organ of the lamina terminalis, the subfornical organ, the area postrema, and the median eminence, brain structures with a leaky blood-brain barrier. Furthermore, nuclear NF-IL6-IR was observed in the pituitary gland, the choroid plexus, and the meninges as well as blood vessels throughout the entire brain. Endothelial, microglial, and ependymal cells, astrocytes, perivascular macrophages, and neurons exhibited LPS-induced nuclear NF-IL6-IR; mRNA levels of NF-IL6, responsive inflammatory genes, and NF-IL6 protein levels were significantly elevated. As opposed to observations on STAT3 or NFκB, the percentage of NF-IL6-reactive cells increased in parallel to late phases of the febrile response. In conclusion, these results suggest a potential role for NF-IL6 in the maintenance or possibly the termination of LPS-induced fever. Moreover, we propose NF-IL6 to be a delayed brain cell activation marker.
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Affiliation(s)
- Jelena Damm
- Department of Veterinary-Physiology, Justus-Liebig-University Giessen, Germany
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Reis R, Brito H, Fraga D, Cabrini D, Zampronio A. Central substance P NK1 receptors are involved in fever induced by LPS but not by IL-1β and CCL3/MIP-1α in rats. Brain Res 2011; 1384:161-9. [DOI: 10.1016/j.brainres.2011.02.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2010] [Revised: 01/31/2011] [Accepted: 02/01/2011] [Indexed: 10/18/2022]
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Gunsolly C, Nicholson JD, Listwak SJ, Ledee D, Zelenka P, Verthelyi D, Chapoval S, Keegan A, Tonelli LH. Expression and regulation in the brain of the chemokine CCL27 gene locus. J Neuroimmunol 2010; 225:82-90. [PMID: 20605223 DOI: 10.1016/j.jneuroim.2010.04.019] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2010] [Revised: 03/31/2010] [Accepted: 04/28/2010] [Indexed: 11/16/2022]
Abstract
The chemokine CCL27 has chemoattractant properties for memory T cells and has been implicated in skin allergic reactions. The present study reports the expression in the brain of two CCL27 splice variants localized in the cerebral cortex and limbic regions. CCL27-like immunoreactivity was identified mainly in neurons. Variant 1 was found elevated in the olfactory bulbs during allergic inflammation induced by intranasal challenge with allergen. This was accompanied by the presence of T cells in the olfactory bulbs. Intranasal administration of neutralizing antibodies against CCL27 reduced the presence of T cells in the olfactory bulbs suggesting a function in T cell activity in the brain.
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Affiliation(s)
- Chad Gunsolly
- Department of Psychiatry, University of Maryland School of Medicine, Baltimore, Maryland 21201-1549, USA
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