| 61. |
- Engström, Linda, et al.
(författare)
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Lipopolysaccharide-Induced Fever Depends on Prostaglandin E2 Production Specifically in Brain Endothelial Cells
- 2012
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Ingår i: Endocrinology. - : Endocrine Society. - 0013-7227 .- 1945-7170. ; 153:10, s. 4849-4861
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Tidskriftsartikel (refereegranskat)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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| 62. |
- Engström, Linda, et al.
(författare)
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Preproenkephalin mRNA expression in rat parabrachial neurons: relation to cells activated by systemic immune challenge
- 2001
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Ingår i: Neuroscience Letters. - : Elsevier Science B.V., Amsterdam.. - 0304-3940 .- 1872-7972. ; 316:3, s. 165-168
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Tidskriftsartikel (refereegranskat)abstract
- By using a dual-labeling immunohistochemical/in situ hybridization technique we examined if enkephalin-expressing neurons in the pontine parabrachial nucleus, a major brain stem relay for ascending visceral and homeostatic information, were activated by systemic immune challenge. While rats subjected to intravenous injection of bacterial wall lipopolysaccharide expressed dense labeling for the immediate-early gene product FOS in parts of the parabrachial nucleus that also demonstrated dense preproenkephalin expression, only a small proportion of the enkephalin-positive neurons were FOS-positive. These data indicate that enkephalins, although implicated in a variety of autonomic responses, are not primarily involved in the transmission of immune-related information from the parabrachial nucleus to its different forebrain and brain stem targets.
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| 63. |
- Engström, Linda, et al.
(författare)
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Systemic immune challenge activates an intrinsically regulated local inflammatory circuit in the adrenal gland
- 2008
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Ingår i: Endocrinology. - : The Endocrine Society. - 0013-7227 .- 1945-7170. ; 149:4, s. 1436-1450
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Tidskriftsartikel (refereegranskat)abstract
- There is evidence from in vitro studies that inflammatory messengers influence the release of stress hormone via direct effects on the adrenal gland; however, the mechanisms underlying these effects in the intact organism are unknown. Here we demonstrate that systemic inflammation in rats elicited by iv injection of lipopolysaccharide results in dynamic changes in the adrenal immune cell population, implying a rapid depletion of dendritic cells in the inner cortical layer and the recruitment of immature cells to the outer layers. These changes are accompanied by an induced production of IL-1β and IL-1 receptor type 1 as well as cyclooxygenase-2 and microsomal prostaglandin E synthase-1 in these cells, implying local cytokine-mediated prostaglandin E2 production in the adrenals, which also displayed prostaglandin E2 receptors of subtypes 1 and 3 in the cortex and medulla. The IL-1β expression was also induced by systemically administrated IL-1β and was in both cases attenuated by IL-1 receptor antagonist, consistent with an autocrine signaling loop. IL-1β similarly induced expression of cyclooxygenase-2, but the cyclooxygenase-2 expression was, in contrast, further enhanced by IL-1 receptor antagonist. These data demonstrate a mechanism by which systemic inflammatory agents activate an intrinsically regulated local signaling circuit that may influence the adrenals’ response to immune stress and may help explain the dissociation between plasma levels of ACTH and corticosteroids during chronic immune perturbations.
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| 64. |
- Engström, Linda, et al.
(författare)
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Systemic immune challenge induces preproenkephalin gene transcription in distinct autonomic structures of the rat brain
- 2003
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Ingår i: Journal of Comparative Neurology. - : Wiley. - 0021-9967 .- 1096-9861. ; 462:4, s. 450-461
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Tidskriftsartikel (refereegranskat)abstract
- The involvement of enkephalins in the immune response was investigated in rats injected intravenously with interleukin-1 (2 g/kg). In situ hybridization with a riboprobe complementary to intron A of the preproenkephalin (ppENK) gene showed distinct transcriptional activation within several brain regions known to be activated by immune stimuli, including the nucleus of the solitary tract, the area postrema, the paraventricular hypothalamic nucleus, and the oval nucleus of the bed nucleus of the stria terminalis, and dual labeling confirmed that a large proportion of the intron expressing neurons co-expressed c-fos mRNA. Rats injected with saline (controls) showed little or no heteronuclear transcript in these structures. The induced signal was strongest after 1 hour but was present in some structures 30 minutes after interleukin-1 injection. At 3 hours, transcriptional activity returned to basal levels. High basal expression of the heteronuclear transcript that appeared unchanged by the immune stimulus was seen in regions not primarily involved in the immune response, such as the striatum, the olfactory tubercle, and the islands of Calleja and in the immune activated central nucleus of the amygdala. The heteronuclear transcript colocalized with ppENK mRNA, demonstrating that it occurred in enkephalinergic neurons and was not the result of alternative transcription from the ppENK gene in other cells. These results demonstrated that enkephalin transcription is induced in central autonomic neurons during immune challenge, suggesting that enkephalins are involved in the centrally orchestrated response to such stimuli.
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| 65. |
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| 66. |
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| 67. |
- Erlinge, David, et al.
(författare)
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Rapid Endovascular Catheter Core Cooling Combined With Cold Saline as an Adjunct to Percutaneous Coronary Intervention for the Treatment of Acute Myocardial Infarction The CHILL-MI Trial : A Randomized Controlled Study of the Use of Central Venous Catheter Core Cooling Combined With Cold Saline as an Adjunct to Percutaneous Coronary Intervention for the Treatment of Acute Myocardial Infarction
- 2014
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Ingår i: Journal of the American College of Cardiology. - : Elsevier BV. - 0735-1097 .- 1558-3597. ; 63:18, s. 1857-1865
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Tidskriftsartikel (refereegranskat)abstract
- Objectives The aim of this study was to confirm the cardioprotective effects of hypothermia using a combination of cold saline and endovascular cooling. Background Hypothermia has been reported to reduce infarct size (IS) in patients with ST-segment elevation myocardial infarctions. Methods In a multicenter study, 120 patients with ST-segment elevation myocardial infarctions (<6 h) scheduled to undergo percutaneous coronary intervention were randomized to hypothermia induced by the rapid infusion of 600 to 2,000 ml cold saline and endovascular cooling or standard of care. Hypothermia was initiated before percutaneous coronary intervention and continued for 1 h after reperfusion. The primary end point was IS as a percent of myocardium at risk (MaR), assessed by cardiac magnetic resonance imaging at 4 +/- 2 days. Results Mean times from symptom onset to randomization were 129 +/- 56 min in patients receiving hypothermia and 132 +/- 64 min in controls. Patients randomized to hypothermia achieved a core body temperature of 34.7 degrees C before reperfusion, with a 9-min longer door-to-balloon time. Median IS/MaR was not significantly reduced (hypothermia: 40.5% [interquartile range: 29.3% to 57.8%; control: 46.6% [interquartile range: 37.8% to 63.4%]; relative reduction 13%; p = 0.15). The incidence of heart failure was lower with hypothermia at 45 +/- 15 days (3% vs. 14%, p < 0.05), with no mortality. Exploratory analysis of early anterior infarctions (0 to 4 h) found a reduction in IS/MaR of 33% (p < 0.05) and an absolute reduction of IS/left ventricular volume of 6.2% (p = 0.15). Conclusions Hypothermia induced by cold saline and endovascular cooling was feasible and safe, and it rapidly reduced core temperature with minor reperfusion delay. The primary end point of IS/MaR was not significantly reduced. Lower incidence of heart failure and a possible effect in patients with early anterior ST-segment elevation myocardial infarctions need confirmation. (Efficacy of Endovascular Catheter Cooling Combined With Cold Saline for the Treatment of Acute Myocardial Infarction [CHILL-MI]; NCT01379261)
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| 68. |
- Erlinge, David, et al.
(författare)
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Therapeutic Hypothermia for the Treatment of Acute Myocardial Infarction-Combined Analysis of the RAPID MI-ICE and the CHILL-MI Trials
- 2015
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Ingår i: Therapeutic Hypothermia and Temperature Management. - : Mary Ann Liebert Inc. - 2153-7658 .- 2153-7933. ; 5:2, s. 77-84
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Tidskriftsartikel (refereegranskat)abstract
- In the randomized rapid intravascular cooling in myocardial infarction as adjunctive to percutaneous coronary intervention (RAPID MI-ICE) and rapid endovascular catheter core cooling combined with cold saline as an adjunct to percutaneous coronary intervention for the treatment of acute myocardial infarction CHILL-MI studies, hypothermia was rapidly induced in conscious patients with ST-elevation myocardial infarction (STEMI) by a combination of cold saline and endovascular cooling. Twenty patients in RAPID MI-ICE and 120 in CHILL-MI with large STEMIs, scheduled for primary percutaneous coronary intervention (PCI) within <6 hours after symptom onset were randomized to hypothermia induced by rapid infusion of 600-2000mL cold saline combined with endovascular cooling or standard of care. Hypothermia was initiated before PCI and continued for 1-3 hours after reperfusion aiming at a target temperature of 33 degrees C. The primary endpoint was myocardial infarct size (IS) as a percentage of myocardium at risk (IS/MaR) assessed by cardiac magnetic resonance imaging at 4 +/- 2 days. Patients randomized to hypothermia treatment achieved a mean core body temperature of 34.7 degrees C before reperfusion. Although significance was not achieved in CHILL-MI, in the pooled analysis IS/MaR was reduced in the hypothermia group, relative reduction (RR) 15% (40.5, 28.0-57.6 vs. 46.6, 36.8-63.8, p=0.046, median, interquartile range [IQR]). IS/MaR was predominantly reduced in early anterior STEMI (0-4h) in the hypothermia group, RR=31% (40.5, 28.8-51.9 vs. 59.0, 45.0-67.8, p=0.01, median, IQR). There was no mortality in either group. The incidence of heart failure was reduced in the hypothermia group (2 vs. 11, p=0.009). Patients with large MaR (>30% of the left ventricle) exhibited significantly reduced IS/MaR in the hypothermia group (40.5, 27.0-57.6 vs. 55.1, 41.1-64.4, median, IQR; hypothermia n=42 vs. control n=37, p=0.03), while patients with MaR<30% did not show effect of hypothermia (35.8, 28.3-57.5 vs. 38.4, 27.4-59.7, median, IQR; hypothermia n=15 vs. control n=19, p=0.50). The prespecified pooled analysis of RAPID MI-ICE and CHILL-MI indicates a reduction of myocardial IS and reduction in heart failure by 1-3 hours with endovascular cooling in association with primary PCI of acute STEMI predominantly in patients with large area of myocardium at risk. (ClinicalTrials.gov id NCT00417638 and NCT01379261).
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| 69. |
- Eskilsson, Anna, 1986-, et al.
(författare)
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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 EP3 Receptors
- 2021
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Ingår i: Journal of Neuroscience. - : SOC NEUROSCIENCE. - 0270-6474 .- 1529-2401. ; 41:24, s. 5206-5218
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Tidskriftsartikel (refereegranskat)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 (PGE(2)) and cytokines in the air pouch and elevated levels of these inflammatory mediators in plasma. There were also elevated levels of PGE(2) in the cerebrospinal fluid, although there was little evidence for PGE(2) synthesis in the brain. Global deletion of the PGE(2) 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 PGE(2) 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 a on these cells, attenuated the febrile response. In contrast, deletion of the PGE(2) 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 PGE(2) entry into the brain from the circulation and hence representing a mechanism distinct from that at work during systemic inflammation.
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| 70. |
- Eskilsson, Anna, et al.
(författare)
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Immune-Induced Fever Is Dependent on Local But Not Generalized Prostaglandin E-2 Synthesis in the Brain
- 2017
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Ingår i: Journal of Neuroscience. - : SOC NEUROSCIENCE. - 0270-6474 .- 1529-2401. ; 37:19, s. 5035-5044
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Tidskriftsartikel (refereegranskat)abstract
- Fever occurs upon binding of prostaglandin E-2 (PGE(2)) to EP3 receptors in the median preoptic nucleus of the hypothalamus, but the origin of the pyrogenic PGE(2) has not been clearly determined. Here, using mice of both sexes, we examined the role of local versus generalized PGE(2) 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 CreER(T2) under the Slco1c1 promoter, PGE(2) levels in the CSF were only weakly related to the magnitude of the febrile response, whereas the PGE(2) 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 PGE(2) 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 PGE(2) onto its target neurons and not on the overall PGE(2) production in the brain.
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