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Dioscin relieves endotoxemia induced acute neuro-inflammation and protect neurogenesis via improving 5-HT metabolism. Sci Rep 2017; 7:40035. [PMID: 28059131 PMCID: PMC5216397 DOI: 10.1038/srep40035] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Accepted: 11/30/2016] [Indexed: 12/16/2022] Open
Abstract
Sepsis, in addition to causing fatality, is an independent risk factor for cognitive impairment among sepsis survivors. The pathologic mechanism of endotoxemia induced acute neuro-inflammation still has not been fully understood. For the first time, we found the disruption of neurotransmitters 5-HT, impaired neurogenesis and activation of astrocytes coupled with concomitant neuro-inflammation were the potential pathogenesis of endotoxemia induced acute neuro-inflammation in sepsis survivors. In addition, dioscin a natural steroidal saponin isolated from Chinese medicinal herbs, enhanced the serotonergic system and produced anti-depressant effect by enhancing 5-HT levels in hippocampus. What is more, this finding was verified by metabolic analyses of hippocampus, indicating 5-HT related metabolic pathway was involved in the pathogenesis of endotoxemia induced acute neuro-inflammation. Moreover, neuro-inflammation and neurogenesis within hippocampus were indexed using quantitative immunofluorescence analysis of GFAP DCX and Ki67, as well as real-time RT-PCR analysis of some gene expression levels in hippocampus. Our in vivo and in vitro studies show dioscin protects hippocampus from endotoxemia induced cascade neuro-inflammation through neurotransmitter 5-HT and HMGB-1/TLR4 signaling pathway, which accounts for the dioscin therapeutic effect in behavioral tests. Therefore, the current findings suggest that dioscin could be a potential approach for the therapy of endotoxemia induced acute neuro-inflammation.
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52
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Brain-Defective Insulin Signaling Is Associated to Late Cognitive Impairment in Post-Septic Mice. Mol Neurobiol 2016; 55:435-444. [PMID: 27966074 DOI: 10.1007/s12035-016-0307-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Accepted: 11/16/2016] [Indexed: 12/26/2022]
Abstract
Sepsis survivors frequently develop late cognitive impairment. Because little is known on the mechanisms of post-septic memory deficits, there are no current effective approaches to prevent or treat such symptoms. Here, we subjected mice to severe sepsis induced by cecal ligation and puncture (CLP) and evaluated the sepsis-surviving animals in the open field, novel object recognition (NOR), and step-down inhibitory avoidance (IA) task at different times after surgery. Post-septic mice (30 days post-surgery) failed in the NOR and IA tests but exhibited normal performance when re-evaluated 45 days after surgery. Cognitive impairment in post-septic mice was accompanied by reduced hippocampal levels of proteins involved in synaptic plasticity, including synaptophysin, cAMP response element-binding protein (CREB), CREB phosphorylated at serine residue 133 (CREBpSer133), and GluA1 phosphorylated at serine residue 845 (GluA1pSer845). Expression of tumor necrosis factor α (TNF-α) was increased and brain insulin signaling was disrupted, as indicated by increased hippocampal IRS-1 phosphorylation at serine 636 (IRS-1pSer636) and decreased phosphorylation of IRS-1 at tyrosine 465 (IRS-1pTyr465), in the hippocampus 30 days after CLP. Phosphorylation of Akt at serine 473 (AktpSer473) and of GSK3 at serine 9 (GSK3βpSer9) were also decreased in hippocampi of post-septic animals, further indicating that brain insulin signaling is disrupted by sepsis. We then treated post-septic mice with liraglutide, a GLP-1 receptor agonist with insulinotropic activity, or TDZD-8, a GSK3β inhibitor, which rescued NOR memory. In conclusion, these results establish that hippocampal inflammation and disrupted insulin signaling are induced by sepsis and are linked to late memory impairment in sepsis survivors.
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Milewski K, Oria M. What we know: the inflammatory basis of hepatic encephalopathy. Metab Brain Dis 2016; 31:1239-1247. [PMID: 26497651 DOI: 10.1007/s11011-015-9740-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 09/24/2015] [Indexed: 02/07/2023]
Abstract
Central Nervous System (CNS) degeneration appearing in patients with cirrhosis is responsible for cognitive and persistent motor impairments that lead to an important impact on life quality. Brain injury affects certain areas of the CNS that might affect two types of cells: neurons and astrocytes. The process leading to brain injury could be induced by portosystemic shunting accompanied by hyperammonemia and by the activation of peripheral inflammation, manifested as episodic encephalopathy. Hyperammonemia combined with a decrease on the BCA/AAA ratio induces alterations of energetic metabolism and the formation of free radicals in the CNS. This process would be stimulated by the activation of peripheral inflammatory mediators that could act on receptors of the blood brain barrier such as TLR4, activating inflammatory responses in the CNS. As a result, a persistent activation of microglia and an irreversible neuronal and astrocytic injury would be induced. A new knowledge of the mechanisms leading to brain injury in cirrhosis would develop protective strategies to correct changes of nitrogen metabolism and inflammation.
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Affiliation(s)
- K Milewski
- Department of Neurotoxicology, Mossakowski Medical Research Centre, Polish Academy of Sciences, Pawińskiego 5 Str, 02-106, Warsaw, Poland
| | - M Oria
- Translational Research in Fetal Surgery for Congenital Malformations, Center for Fetal, Cellular and Molecular Therapy, Division of Pediatric General and Thoracic Surgery, Cincinnati Children's Hospital Medical Center (CCHMC), 3333 Burnet Avenue, MLC 11020, S 8.400 AT, Cincinnati, OH, 45229-3039, USA.
- Liver Failure Group, UCL Institute for Liver and Digestive Health, Royal Free Hospital, University College London, London, UK.
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54
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Huerta PT, Robbiati S, Huerta TS, Sabharwal A, Berlin R, Frankfurt M, Volpe BT. Preclinical models of overwhelming sepsis implicate the neural system that encodes contextual fear memory. Mol Med 2016; 22:789-799. [PMID: 27878209 PMCID: PMC5193462 DOI: 10.2119/molmed.2015.00201] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Accepted: 11/02/2016] [Indexed: 01/06/2023] Open
Abstract
Long-term sepsis survivors sustain cryptic brain injury that leads to cognitive impairment, emotional imbalance, and increased disability burden. Suitable animal models of sepsis, such as cecal ligation and puncture (CLP), have permitted the analysis of abnormal brain circuits that underlie post-septic behavioral phenotypes. For instance, we have previously shown that CLP-exposed mice exhibit impaired spatial memory together with depleted dendritic arbors and decreased spines in the apical dendrites of pyramidal neurons in the CA1 region of the hippocampus. Here we show that contextual fear conditioning, a form of associative memory for fear, is chronically disrupted in CLP mice when compared to SHAM-operated animals. We also find that the excitatory neurons in the basolateral nucleus of the amygdala (BLA) and the granule cells in the dentate gyrus (DG) display significantly fewer dendritic spines in the CLP group relative to the SHAM mice, although the dendritic arbors and gross morphology of the BLA and DG are comparable between the two groups. Moreover, the basal dendrites of CA1 pyramidal neurons are unaffected in the CLP mice. Taken together, our data indicate that the structural damage in the amygdalar-hippocampal network represents the neural substrate for impaired contextual fear memory in long-term sepsis survivors. Further, our data suggest that the brain injury caused by overwhelming sepsis alters the stability of the synaptic connections involved in associative fear. These results likely have implications for the emotional imbalance observed in human sepsis survivors.
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Affiliation(s)
- Patricio T Huerta
- Laboratory of Immune and Neural Networks, The Feinstein Institute for Medical Research, Northwell Health, Manhasset, NY, United States of America
- Department of Molecular Medicine, Hofstra Northwell School of Medicine, Hempstead, NY, United States of America
| | - Sergio Robbiati
- Laboratory of Immune and Neural Networks, The Feinstein Institute for Medical Research, Northwell Health, Manhasset, NY, United States of America
| | - Tomás S Huerta
- Laboratory of Immune and Neural Networks, The Feinstein Institute for Medical Research, Northwell Health, Manhasset, NY, United States of America
| | - Anchal Sabharwal
- Laboratory of Immune and Neural Networks, The Feinstein Institute for Medical Research, Northwell Health, Manhasset, NY, United States of America
| | - Roseann Berlin
- Laboratory of Biomedical Science, The Feinstein Institute for Medical Research, Northwell Health, Manhasset, NY, United States of America
| | - Maya Frankfurt
- Department of Science Education, Hofstra Northwell School of Medicine, Hempstead, NY, United States of America
| | - Bruce T Volpe
- Department of Molecular Medicine, Hofstra Northwell School of Medicine, Hempstead, NY, United States of America
- Laboratory of Biomedical Science, The Feinstein Institute for Medical Research, Northwell Health, Manhasset, NY, United States of America
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55
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Wright G, Swain M, Annane D, Saliba F, Samuel D, Arroyo V, DeMorrow S, Witt A. Neuroinflammation in liver disease: sessional talks from ISHEN. Metab Brain Dis 2016; 31:1339-1354. [PMID: 27726053 DOI: 10.1007/s11011-016-9918-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Accepted: 09/27/2016] [Indexed: 12/20/2022]
Abstract
At the recent ISHEN ('International Symposium of Hepatic Encephalopathy & Nitrogen Metabolism') conference in London, a whole session was dedicated to our increasing awareness of the importance of inflammation in the brain - termed 'neuroinflammation', in the development of Hepatic Encephalopathy (HE) - the neurological manifestations of advanced liver disease. In this review our ISHEN speakers further discuss the content of their sessional presentations and more broadly we discuss our understanding of the role of neuroinflammation in HE pathogenesis.
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Affiliation(s)
- Gavin Wright
- Gastroenterology Department, Basildon & Thurrock University Hospitals, Basildon, UK.
- Hepatology and Hepatobiliary Medicine, The Royal Free Hospital, Pond Street, London, NW3 2QG, UK.
- University College London, Gower Street, London, WC1E 6BT, UK.
| | - Mark Swain
- Division of Gastroenterology and Hepatology, University of Calgary, Calgary, Canada
| | - Djillali Annane
- INSERM CIC IT 805, CHU Paris IdF Ouest - Hôpital Raymond Poincaré, 104 boulevard Raymond Poincaré, 92380, Garches, France
| | - Faouzi Saliba
- Centre Hépato-Biliaire, Hôpital Paul Brousse, 12, avenue Paul vaillant Couturier, 94800, Villejuif, France
| | - Didier Samuel
- GHU Paris-Sud - Hôpital Paul Brousse, 12 avenue Paul Vaillant-Couturier, 94804, Villejuif Cedex, France
| | - Vicente Arroyo
- Liver Unit, Instiute of Digestive and Metabolic Diseases, Hopsital Clinic, University of Barcelona, Barcelona, Spain
| | - Sharon DeMorrow
- Department of Internal Medicine, Central Texas Veterans Healthcare System, VA Bld 205, 1901 South 1st Street, Temple, TX, 76504, USA
| | - Anne Witt
- Departement of Hepatology, Rigshospitalet, Blegdamsvej 9, 2100 København Ø, Copenhagen, Denmark
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56
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Catalão CHR, Santos-Júnior NN, da Costa LHA, Souza AO, Alberici LC, Rocha MJA. Brain Oxidative Stress During Experimental Sepsis Is Attenuated by Simvastatin Administration. Mol Neurobiol 2016; 54:7008-7018. [PMID: 27796742 DOI: 10.1007/s12035-016-0218-3] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Accepted: 10/12/2016] [Indexed: 12/16/2022]
Abstract
During sepsis, brain damage is associated with oxidative stress due to overproduction of reactive oxygen species (ROS). Although there are recent reports about the benefits of statins in experimental sepsis and endotoxemia in peripheral organs, little is known about their effects in the CNS. Here, we investigated the antioxidant properties of simvastatin and its possible neuroprotective role during experimental sepsis. Male Wistar rats (250-300 g) were submitted to cecal ligation and puncture (CLP, n = 34) or remained as non-manipulated (naive, n = 34). Both groups were treated by gavage with simvastatin (20 mg/kg) or an equivalent volume of saline. The animals submitted to CLP were treated 4 days before and 48 h after surgery. One animal group was decapitated and the blood and brain were collected to quantify plasma levels of cytokines and assess astrogliosis and apoptosis in the prefrontal cortex and hippocampus. Another group was perfused with PBS (0.01 M), and the same brain structures were dissected to analyze oxidative damage. The CLP rats treated with simvastatin showed a reduction in nitric oxide (P < 0.05), IL1-β (P < 0.001), IL-6 (P < 0.01), and TBARS levels (P < 0.001) and an increase in catalase activity (P < 0.01), citrate synthase enzyme (P < 0.05), and normalized GSH/GSSG ratio. In addition, the histopathological analysis showed a reduction (P < 0.001) in reactive astrocytes and caspase 3-positive apoptotic cells. The results suggest a possible neuroprotective effect of simvastatin in structures responsible for spatial learning and memory and indicate the need for behavioral studies evaluating the impact on cognitive damage, as frequently seen in patients surviving sepsis.
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Affiliation(s)
- Carlos Henrique Rocha Catalão
- Department of Neurosciences and Behavioral Sciences of Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Nilton Nascimento Santos-Júnior
- Department of Neurosciences and Behavioral Sciences of Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Luís Henrique Angenendt da Costa
- Department of Neurosciences and Behavioral Sciences of Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Anderson Oliveira Souza
- Department of Physics and Chemistry, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Luciane Carla Alberici
- Department of Physics and Chemistry, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Maria José Alves Rocha
- Department of Morphology, Physiology and Basic Pathology, School of Dentistry of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil.
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Abstract
A growing body of literature has shown that survivors of critical illness often struggle with cognitive impairment that persists months to years after hospital discharge. We describe the epidemiology of this form of cognitive impairment-which we refer to as critical illness brain injury-and review the history and maturation of the investigation of this previously unrecognized, yet common problem. We then review the characteristics of critical illness brain injury, which can vary in severity and typically affects multiple domains of cognition. Finally, we examine known risk factors for critical illness brain injury and, based on these data, suggest approaches to patient management.
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Affiliation(s)
- Timothy D Girard
- Division of Allergy, Pulmonary, and Critical Care Medicine.,Center for Health Services Research, and.,Geriatric Research, Education and Clinical Center (GRECC) Service at the Department of Veterans Affairs Medical Center, Tennessee Valley Healthcare System, Nashville, Tennessee 37212
| | - Robert S Dittus
- Center for Health Services Research, and.,Division of General Internal Medicine and Public Health in the Department of Medicine and The Institute for Medicine and Public Health at the Vanderbilt University School of Medicine, Nashville, Tennessee 37232; .,Geriatric Research, Education and Clinical Center (GRECC) Service at the Department of Veterans Affairs Medical Center, Tennessee Valley Healthcare System, Nashville, Tennessee 37212
| | - E Wesley Ely
- Division of Allergy, Pulmonary, and Critical Care Medicine.,Center for Health Services Research, and.,Geriatric Research, Education and Clinical Center (GRECC) Service at the Department of Veterans Affairs Medical Center, Tennessee Valley Healthcare System, Nashville, Tennessee 37212
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58
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Souza-Dantas VC, Póvoa P, Bozza F, Soares M, Salluh J. Preventive strategies and potential therapeutic interventions for delirium in sepsis. Hosp Pract (1995) 2016; 44:190-202. [PMID: 27223862 DOI: 10.1080/21548331.2016.1192453] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Accepted: 05/18/2016] [Indexed: 06/05/2023]
Abstract
Delirium is the most frequent and severe clinical presentation of brain dysfunction in critically ill septic patients with an incidence ranging from 9% to 71%. Delirium represents a significant burden for patients and relatives, as well as to the health care system, resulting in higher costs, long-term cognitive impairment and significant risk of death after 6 months. Current interventions for the prevention of delirium typically involve early recognition and amelioration of modifiable risk factors and treatment of underlying conditions that predisposes the individual to delirium. Several pharmacological interventions to prevent and treat delirium have been tested, although their effectiveness remains uncertain, especially in larger and more homogeneous subgroups of ICU patients, like in patients with sepsis. To date, there is inconsistent and conflicting data regarding the efficacy of any particular pharmacological agent, thus substantial attention has been paid to non-pharmacological interventions and preventive strategies should be applied to every patient admitted in the ICU. Future trials should be designed to evaluate the impact of these pharmacologic interventions on the prevention and treatment of delirium on clinically relevant outcomes such as length of stay, hospital mortality and long-term cognitive function. The role of specific medications like statins in delirium prevention is also yet to be evaluated.
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Affiliation(s)
| | - Pedro Póvoa
- b Polyvalent Intensive Care Unit, Hospital S. Francisco Xavier , Centro Hospitalar de Lisboa Ocidental (CHLO) , Lisbon , Portugal
- c Nova Medical School , CEDOC, New University of Lisbon , Portugal
| | - Fernando Bozza
- d Oswaldo Cruz Foundation , Rio de Janeiro , Brazil
- e D'Or Institute for Research and Education , Rio de Janeiro , Brazil
| | - Marcio Soares
- e D'Or Institute for Research and Education , Rio de Janeiro , Brazil
| | - Jorge Salluh
- e D'Or Institute for Research and Education , Rio de Janeiro , Brazil
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59
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Volpe BT, Berlin RA, Frankfurt M. The brain at risk: the sepsis syndrome and lessons from preclinical experiments. Immunol Res 2016; 63:70-4. [PMID: 26440589 DOI: 10.1007/s12026-015-8704-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
There is a growing awareness of the chronic brain injury that results from the sepsis syndrome. We review experiments in several animal models of sepsis and show in one model, cecal ligation and puncture (CLP), that permanent structural pathology matures after the initial event. Specifically, we observed after exposure to CLP significant decreased spine density on the apical tree, but not the basal tree, of dendrites in the CA1 region of the dorsal hippocampus that was accompanied by a significantly diminished arbor of the apical dendrites, by 8 weeks, but not after 2 weeks. These novel data from dendritic arborizations elaborate information about a cohort of mice that had behaved in spatial memory tasks. These results raise questions about the relationship between long-term behavioral consequences and intervention strategies.
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Affiliation(s)
- Bruce T Volpe
- Laboratory of Biomedical Science, Feinstein Institute for Medical Research, 350 Community Drive, Manhasset, NY, 11030, USA. .,Department of Molecular Medicine, Hofstra North Shore LIJ Medical School, Hempstead, NY, USA.
| | - Rose Ann Berlin
- Autoimmunity Center, Feinstein Institute for Medical Research, Manhasset, NY, USA
| | - Maya Frankfurt
- Department of Science Education, Hofstra North Shore LIJ Medical School, Hempstead, NY, USA
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60
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Liu X, Qin Y, Dai A, Zhang Y, Xue H, Ni H, Han L, Zhu L, Yuan D, Tao T, Cao M. SMAD4 is Involved in the Development of Endotoxin Tolerance in Microglia. Cell Mol Neurobiol 2016; 36:777-88. [PMID: 26758028 DOI: 10.1007/s10571-015-0260-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Accepted: 08/25/2015] [Indexed: 12/11/2022]
Abstract
Initial exposure of macrophages to LPS induces hyporesponsiveness to a second challenge with LPS, a phenomenon termed LPS tolerance. Smad4 plays important roles in the induction of LPS tolerance. However, the function of Smad4 in microglia remains unknown. Here we show that expression of Smad4 was highly up-regulated in LPS-tolerized mouse cerebral cortex. Smad4 was mostly colocalized with microglia, rarely with neurons. Using a microglia cell line, BV2, we find that LPS activates endogenous Smad4, inducing its migration into the nucleus and increasing its expression. Smad4 significantly suppressed TLR-triggered production of proinflammatory cytokines (IL-6), increased anti-inflammatory cytokine in LPS-tolerized microglia. Moreover, IL-6 concentrations in culture supernatants after second LPS challenge are higher in SMAD4 small interfering RNA (siRNA) BV2 cells than control siRNA BV2 cells, indicating failure to induce tolerance in absence of Smad4 signaling. In our study, we conclude that both in vivo and in vitro, Smad4 signaling is required for maximal induction of endotoxin tolerance.
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Affiliation(s)
- Xiaorong Liu
- Department of Neurology, Affiliated Hospital of Nantong University, Nantong, 226001, China
| | - Yongwei Qin
- Jiangsu Province Key Laboratory for Inflammation and Molecular Drug Target, Medical College of Nantong University, Nantong, 226001, Chcina
- Department of Pathogen Biology, Medical College of Nantong University, Nantong, 226001, China
| | - Aihua Dai
- Department of Neurology, Affiliated Hospital of Nantong University, Nantong, 226001, China
| | - Yu Zhang
- Department of Neurology, Affiliated Hospital of Nantong University, Nantong, 226001, China
| | - Huaqing Xue
- Jiangsu Province Key Laboratory for Inflammation and Molecular Drug Target, Medical College of Nantong University, Nantong, 226001, Chcina
| | - Haidan Ni
- Department of Neurology, Affiliated Hospital of Nantong University, Nantong, 226001, China
| | - Lijian Han
- Department of Neurology, Affiliated Hospital of Nantong University, Nantong, 226001, China
| | - Liang Zhu
- Department of Neurology, Affiliated Hospital of Nantong University, Nantong, 226001, China
| | - Debin Yuan
- Jiangsu Province Key Laboratory for Inflammation and Molecular Drug Target, Medical College of Nantong University, Nantong, 226001, Chcina
| | - Tao Tao
- Jiangsu Province Key Laboratory for Inflammation and Molecular Drug Target, Medical College of Nantong University, Nantong, 226001, Chcina.
| | - Maohong Cao
- Department of Neurology, Affiliated Hospital of Nantong University, Nantong, 226001, China.
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61
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Characterization of Brain-Heart Interactions in a Rodent Model of Sepsis. Mol Neurobiol 2016; 54:3745-3752. [PMID: 27229490 PMCID: PMC5443875 DOI: 10.1007/s12035-016-9941-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Accepted: 05/03/2016] [Indexed: 11/23/2022]
Abstract
Loss of heart rate variability (HRV) and autonomic dysfunction are associated with poor outcomes in critically ill patients. Neuronal networks comprising brainstem and hypothalamus are involved in the “flight-or-fight” response via control over the autonomic nervous system and circulation. We hypothesized that sepsis-induced inflammation in brain regions responsible for autonomic control is associated with sympathovagal imbalance and depressed contractility. Sepsis was induced by fecal slurry injection in fluid-resuscitated rats. Sham-operated animals served as controls. Echocardiography-derived peak velocity (PV) was used to separate septic animals into good (PV ≥0.93 m/s, low 72-h mortality) and bad (PV <0.93, high 72-h mortality) prognosis. Cytokine protein levels were assessed by ELISA. All experiments were performed at 24 h post-insult. Increased levels of inflammation and oxidative injury were observed in the hypothalamus (TNF-α, IL-10, nitrite and nitrate and carbonyl groups) and brainstem (IL-1, IL-6, IL-10, nitrite and nitrate and carbonyl groups) of the septic animals (p < 0.05 vs. sham), but not in the pre-frontal cortex, an area not directly implicated in control of the autonomic nervous system. Good prognosis septic animals had increased sympathetic output and increased left ventricular contractility (p < 0.05 vs. sham). There was a significant inverse correlation between high frequency power (a marker of parasympathetic outflow) and contractility (r = −0.73, p < 0.05). We found no correlation between the degree of inflammation or injury to autonomic centers and cardiovascular function. In conclusion, control of autonomic centers and cardiac function in our long-term rodent model of sepsis was related to clinical severity but not directly to the degree of inflammation.
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62
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Singer BH, Newstead MW, Zeng X, Cooke CL, Thompson RC, Singer K, Ghantasala R, Parent JM, Murphy GG, Iwashyna TJ, Standiford TJ. Cecal Ligation and Puncture Results in Long-Term Central Nervous System Myeloid Inflammation. PLoS One 2016; 11:e0149136. [PMID: 26862765 PMCID: PMC4749127 DOI: 10.1371/journal.pone.0149136] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Accepted: 01/26/2016] [Indexed: 12/24/2022] Open
Abstract
Survivors of sepsis often experience long-term cognitive and functional decline. Previous studies utilizing lipopolysaccharide injection and cecal ligation and puncture in rodent models of sepsis have demonstrated changes in depressive-like behavior and learning and memory after sepsis, as well as evidence of myeloid inflammation and cytokine expression in the brain, but the long-term course of neuroinflammation after sepsis remains unclear. Here, we utilize cecal ligation and puncture with greater than 80% survival as a model of sepsis. We found that sepsis survivor mice demonstrate deficits in extinction of conditioned fear, but no acquisition of fear conditioning, nearly two months after sepsis. These cognitive changes occur in the absence of neuronal loss or changes in synaptic density in the hippocampus. Sepsis also resulted in infiltration of monocytes and neutrophils into the CNS at least two weeks after sepsis in a CCR2 independent manner. Cellular inflammation is accompanied by long-term expression of pro-inflammatory cytokine and chemokine genes, including TNFα and CCR2 ligands, in whole brain homogenates. Gene expression analysis of microglia revealed that while microglia do express anti-microbial genes and damage-associated molecular pattern molecules of the S100A family of genes at least 2 weeks after sepsis, they do not express the cytokines observed in whole brain homogenates. Our results indicate that in a naturalistic model of infection, sepsis results in long-term neuroinflammation, and that this sustained inflammation is likely due to interactions among multiple cell types, including resident microglia and peripherally derived myeloid cells.
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Affiliation(s)
- Benjamin H. Singer
- Department of Internal Medicine, Division of Pulmonary and Critical Care Medicine, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
- * E-mail:
| | - Michael W. Newstead
- Department of Internal Medicine, Division of Pulmonary and Critical Care Medicine, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Xianying Zeng
- Department of Internal Medicine, Division of Pulmonary and Critical Care Medicine, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Christopher L. Cooke
- Molecular and Behavioral Neuroscience Institute, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Robert C. Thompson
- Molecular and Behavioral Neuroscience Institute, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Kanakadurga Singer
- Department of Pediatrics, Division of Endocrinology and Metabolism, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Ramya Ghantasala
- Department of Internal Medicine, Division of Pulmonary and Critical Care Medicine, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Jack M. Parent
- Department of Neurology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Geoffrey G. Murphy
- Molecular and Behavioral Neuroscience Institute, University of Michigan, Ann Arbor, Michigan, United States of America
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Theodore J. Iwashyna
- Department of Internal Medicine, Division of Pulmonary and Critical Care Medicine, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
- Center for Clinical Management Research, VA Ann Arbor Health System, Ann Arbor, Michigan, United States of America
| | - Theodore J. Standiford
- Department of Internal Medicine, Division of Pulmonary and Critical Care Medicine, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
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63
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Michels M, Steckert AV, Quevedo J, Barichello T, Dal-Pizzol F. Mechanisms of long-term cognitive dysfunction of sepsis: from blood-borne leukocytes to glial cells. Intensive Care Med Exp 2015; 3:30. [PMID: 26515197 PMCID: PMC4626467 DOI: 10.1186/s40635-015-0066-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Accepted: 10/21/2015] [Indexed: 12/12/2022] Open
Abstract
Several mechanisms are associated with brain dysfunction during sepsis; one of the most important are activation of microglia and astrocytes. Activation of glial cells induces changes in permeability of the blood-brain barrier, secretion of inflammatory cytokines, and these alterations could induce neuronal dysfunction. Furthermore, blood-borne leukocytes can also reach the brain and participate in inflammatory response. Mechanisms involved in sepsis-associated brain dysfunction were revised here, focusing in neuroinflammation and involvement of blood-borne leukocytes and glial cells in this process.
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Affiliation(s)
- Monique Michels
- Laboratory of Experimental Pathophysiology, Graduate Program in Health Sciences, Health Sciences Unit, University of Southern Santa Catarina, Criciúma, SC, 88806-000, Brazil.
| | - Amanda V Steckert
- Laboratory of Neurosciences, Graduate Program in Health Sciences, Health Sciences Unit, University of Southern Santa Catarina, Criciúma, SC, Brazil.
| | - João Quevedo
- Laboratory of Neurosciences, Graduate Program in Health Sciences, Health Sciences Unit, University of Southern Santa Catarina, Criciúma, SC, Brazil.
- Center for Translational Psychiatry, Department of Psychiatry and Behavioral Sciences, Medical School, The University of Texas at Houston, Houston, TX, USA.
| | - Tatiana Barichello
- Laboratory of Neurosciences, Graduate Program in Health Sciences, Health Sciences Unit, University of Southern Santa Catarina, Criciúma, SC, Brazil.
- Center for Translational Psychiatry, Department of Psychiatry and Behavioral Sciences, Medical School, The University of Texas at Houston, Houston, TX, USA.
| | - Felipe Dal-Pizzol
- Laboratory of Experimental Pathophysiology, Graduate Program in Health Sciences, Health Sciences Unit, University of Southern Santa Catarina, Criciúma, SC, 88806-000, Brazil.
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Anderson ST, Commins S, Moynagh P, Coogan AN. Chronic fluoxetine treatment attenuates post-septic affective changes in the mouse. Behav Brain Res 2015; 297:112-5. [PMID: 26455875 DOI: 10.1016/j.bbr.2015.10.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Revised: 10/02/2015] [Accepted: 10/03/2015] [Indexed: 11/18/2022]
Abstract
It has been previously demonstrated that the induction of sepsis in rodents results in persistent impairments in affective and cognitive domains. In this study we have examined the impact of chronic treatment with the antidepressant fluoxetine on affective behaviours and hippocampal neuroinflammation and stem cell proliferation in animals that have previously undergone sepsis induced by peripheral treatment with lipopolysaccharide. We find that fluoxetine significantly attenuates post-septic increases in behavioural despair and motivated exploration, whilst also reversing the effects of previous sepsis on activated microglia and stem cell proliferation. These results indicate that conventional antidepressants may be effective in the management of mood disorders in survivors of sepsis.
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Affiliation(s)
- Sean T Anderson
- Maynooth University Department of Psychology, National University of Ireland, Maynooth, Ireland
| | - Sean Commins
- Maynooth University Department of Psychology, National University of Ireland, Maynooth, Ireland
| | - Paul Moynagh
- Maynooth University Department of Biology, National University of Ireland, Maynooth, Ireland
| | - Andrew N Coogan
- Maynooth University Department of Psychology, National University of Ireland, Maynooth, Ireland.
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Miguez A, García-Díaz Barriga G, Brito V, Straccia M, Giralt A, Ginés S, Canals JM, Alberch J. Fingolimod (FTY720) enhances hippocampal synaptic plasticity and memory in Huntington's disease by preventing p75NTR up-regulation and astrocyte-mediated inflammation. Hum Mol Genet 2015; 24:4958-70. [PMID: 26063761 DOI: 10.1093/hmg/ddv218] [Citation(s) in RCA: 96] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Accepted: 06/07/2015] [Indexed: 12/20/2022] Open
Abstract
Huntington's disease (HD) is a hereditary neurodegenerative disorder characterized by motor and cognitive impairments, involving striatum, cortex and hippocampus. Synaptic and memory dysfunction in HD mouse models have been related to low levels of brain-derived neurotrophic factor (BDNF) and imbalance between TrkB and p75(NTR) receptors. In addition, astrocyte over-activation has also been suggested to contribute to HD cognitive deficits. Fingolimod (FTY720), a modulator of sphingosine-1 phosphate (S1P) receptors, has been shown to increase BDNF levels and to reduce astrogliosis, proving its potential to regulate trophic support and inflammatory response. In this view, we have investigated whether FTY720 improves synaptic plasticity and memory in the R6/1 mouse model of HD, through regulation of BDNF signaling and astroglial reactivity. Chronic administration of FTY720 from pre-symptomatic stages ameliorated long-term memory deficits and dendritic spine loss in CA1 hippocampal neurons from R6/1 mice. Furthermore, FTY720 delivery prevented astrogliosis and over-activation of nuclear factor kappa beta (NF-κB) signaling in the R6/1 hippocampus, reducing tumor necrosis factor alpha (TNFα) and induced nitric oxide synthase (iNOS) levels. TNFα decrease correlated with the normalization of p75(NTR) expression in the hippocampus of FTY720-treated R6/1 mice, thus preventing p75(NTR)/TrkB imbalance. In addition, FTY720 increased cAMP levels and promoted phosphorylation of CREB and RhoA in the hippocampus of R6/1 mice, further supporting its role in the enhancement of synaptic plasticity. Our findings provide new insights into the mechanism of action of FTY720 and reveal a novel therapeutic strategy to treat memory deficits in HD.
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Affiliation(s)
- Andrés Miguez
- Departament de Biologia Cel·lular, Immunologia i Neurociències, Facultat de Medicina, Universitat de Barcelona, 08036 Barcelona, Spain, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), 08036 Barcelona, Spain and Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Gerardo García-Díaz Barriga
- Departament de Biologia Cel·lular, Immunologia i Neurociències, Facultat de Medicina, Universitat de Barcelona, 08036 Barcelona, Spain, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), 08036 Barcelona, Spain and Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Verónica Brito
- Departament de Biologia Cel·lular, Immunologia i Neurociències, Facultat de Medicina, Universitat de Barcelona, 08036 Barcelona, Spain, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), 08036 Barcelona, Spain and Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Marco Straccia
- Departament de Biologia Cel·lular, Immunologia i Neurociències, Facultat de Medicina, Universitat de Barcelona, 08036 Barcelona, Spain, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), 08036 Barcelona, Spain and Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Albert Giralt
- Departament de Biologia Cel·lular, Immunologia i Neurociències, Facultat de Medicina, Universitat de Barcelona, 08036 Barcelona, Spain, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), 08036 Barcelona, Spain and Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Silvia Ginés
- Departament de Biologia Cel·lular, Immunologia i Neurociències, Facultat de Medicina, Universitat de Barcelona, 08036 Barcelona, Spain, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), 08036 Barcelona, Spain and Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Josep M Canals
- Departament de Biologia Cel·lular, Immunologia i Neurociències, Facultat de Medicina, Universitat de Barcelona, 08036 Barcelona, Spain, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), 08036 Barcelona, Spain and Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Jordi Alberch
- Departament de Biologia Cel·lular, Immunologia i Neurociències, Facultat de Medicina, Universitat de Barcelona, 08036 Barcelona, Spain, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), 08036 Barcelona, Spain and Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
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Li R, Tong J, Tan Y, Zhu S, Yang J, Ji M. Low molecular weight heparin prevents lipopolysaccharide induced-hippocampus-dependent cognitive impairments in mice. INTERNATIONAL JOURNAL OF CLINICAL AND EXPERIMENTAL PATHOLOGY 2015; 8:8881-8891. [PMID: 26464629 PMCID: PMC4583861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Accepted: 07/24/2015] [Indexed: 06/05/2023]
Abstract
Sepsis-associated encephalopathy (SAE) is a common complication after sepsis development, which is associated with the poor prognosis. However, no effective agent is currently available to treat this complication. The objective of the present study was to investigate whether low-molecular-weight heparin (LMWH) has protective effects against sepsis-induced cognitive impairments. Male mice were randomly divided into the control + vehicle, control + LMWH, lipopolysaccharide (LPS) + vehicle, or LPS + LMWH group. LMWH was administrated 30 min after the LPS administration (5 mg/kg) and daily afterward for 2 days. The survival rate was estimated by the Kaplan-Meier method. Behavioral tests were performed by open field and fear conditioning tests at day 7 after LPS administration. The levels of tumor necrosis factor alpha, interleukin (IL)-1β, IL-6, IL-10, malondialdehyde, and superoxide dismutase, Toll-like receptor 4, nuclear factor kappa B p65, inducible nitric oxide synthase, cyclooxygenase-2, occluding, high mobility group box-1, brain derived neurotrophic factor, and IBA1 positive cells were assessed at the indicated time points. LMWH attenuated LPS-induced hippocampus-dependent cognitive impairments, which was accompanied by decreased hippocampal IL-1β, malondialdehyde, Toll-like receptor 4, nuclear factor kappa B p65, inducible nitric oxide synthase, cyclooxygenase-2, high mobility group box-1 protein, and IBA1 positive cells, and increased occluding and brain derived neurotrophic factor levels. In conclusion, LMWH treatment protects against sepsis-induced cognitive impairments by attenuating hippocampal microglial activation, cytokine and oxidative stress production, disruption of blood-brain barrier, and the loss of synaptic plasticity related proteins.
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Affiliation(s)
- Renqi Li
- Department of Anesthesiology, Jinling Hospital, School of Medicine, Nanjing University Nanjing, China
| | - Jianhua Tong
- Department of Anesthesiology, Jinling Hospital, School of Medicine, Nanjing University Nanjing, China
| | - Yuanhui Tan
- Department of Anesthesiology, Jinling Hospital, School of Medicine, Nanjing University Nanjing, China
| | - Sihai Zhu
- Department of Anesthesiology, Jinling Hospital, School of Medicine, Nanjing University Nanjing, China
| | - Jianjun Yang
- Department of Anesthesiology, Jinling Hospital, School of Medicine, Nanjing University Nanjing, China
| | - Muhuo Ji
- Department of Anesthesiology, Jinling Hospital, School of Medicine, Nanjing University Nanjing, China
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Fong TG, Davis D, Growdon ME, Albuquerque A, Inouye SK. The interface between delirium and dementia in elderly adults. Lancet Neurol 2015; 14:823-832. [PMID: 26139023 DOI: 10.1016/s1474-4422(15)00101-5] [Citation(s) in RCA: 346] [Impact Index Per Article: 38.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Revised: 04/27/2015] [Accepted: 05/18/2015] [Indexed: 02/02/2023]
Abstract
Delirium and dementia are two of the most common causes of cognitive impairment in older populations, yet their interrelation remains poorly understood. Previous studies have shown that dementia is the leading risk factor for delirium and that delirium is an independent risk factor for subsequent development of dementia. However, a major area of controversy is whether delirium is simply a marker of vulnerability to dementia, whether the effect of delirium is solely related to its precipitating factors, or whether delirium itself can cause permanent neuronal damage and lead to dementia. Ultimately, all of these hypotheses are likely to be true. Emerging evidence from epidemiological, clinicopathological, neuroimaging, biomarker, and experimental studies lends support to a strong relation between delirium and dementia, and to both shared and distinct pathological mechanisms. New preventive and therapeutic approaches that target delirium might offer a sought-after opportunity for early intervention, preservation of cognitive reserve, and prevention of irreversible cognitive decline in ageing.
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Affiliation(s)
- Tamara G Fong
- Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA; Aging Brain Center, Institute for Aging Research, Hebrew SeniorLife, Boston, MA, USA
| | - Daniel Davis
- MRC Unit for Lifelong Health and Ageing, UCL, London, UK
| | - Matthew E Growdon
- Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Asha Albuquerque
- Aging Brain Center, Institute for Aging Research, Hebrew SeniorLife, Boston, MA, USA
| | - Sharon K Inouye
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA; Aging Brain Center, Institute for Aging Research, Hebrew SeniorLife, Boston, MA, USA.
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Hoogland ICM, Houbolt C, van Westerloo DJ, van Gool WA, van de Beek D. Systemic inflammation and microglial activation: systematic review of animal experiments. J Neuroinflammation 2015; 12:114. [PMID: 26048578 PMCID: PMC4470063 DOI: 10.1186/s12974-015-0332-6] [Citation(s) in RCA: 613] [Impact Index Per Article: 68.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Accepted: 05/26/2015] [Indexed: 12/20/2022] Open
Abstract
Background Animal studies show that peripheral inflammatory stimuli may activate microglial cells in the brain implicating an important role for microglia in sepsis-associated delirium. We systematically reviewed animal experiments related to the effects of systemic inflammation on the microglial and inflammatory response in the brain. Methods We searched PubMed between January 1, 1950 and December 1, 2013 and Embase between January 1, 1988 and December 1, 2013 for animal studies on the influence of peripheral inflammatory stimuli on microglia and the brain. Identified studies were systematically scored on methodological quality. Two investigators extracted independently data on animal species, gender, age, and genetic background; number of animals; infectious stimulus; microglial cells; and other inflammatory parameters in the brain, including methods, time points after inoculation, and brain regions. Results Fifty-one studies were identified of which the majority was performed in mice (n = 30) or in rats (n = 19). Lipopolysaccharide (LPS) (dose ranging between 0.33 and 200 mg/kg) was used as a peripheral infectious stimulus in 39 studies (76 %), and live or heat-killed pathogens were used in 12 studies (24 %). Information about animal characteristics such as species, strain, sex, age, and weight were defined in 41 studies (80 %), and complete methods of the disease model were described in 35 studies (68 %). Studies were also heterogeneous with respect to methods used to assess microglial activation; markers used mostly were the ionized calcium binding adaptor molecule-1 (Iba-1), cluster of differentiation 68 (CD68), and CD11b. After LPS challenge microglial activation was seen 6 h after challenge and remained present for at least 3 days. Live Escherichia coli resulted in microglial activation after 2 days, and heat-killed bacteria after 2 weeks. Concomitant with microglial response, inflammatory parameters in the brain were reviewed in 23 of 51 studies (45 %). Microglial activation was associated with an increase in Toll-like receptor (TLR-2 and TLR-4), tumor necrosis factor alpha (TNF-α), and interleukin 1 beta (IL-1β) messenger ribonucleic acid (mRNA) expression or protein levels. Interpretation Animal experiments robustly showed that peripheral inflammatory stimuli cause microglial activation. We observed distinct differences in microglial activation between systemic stimulation with (supranatural doses) LPS and live or heat-killed bacteria.
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Affiliation(s)
- Inge C M Hoogland
- Department of Neurology, Center of Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
| | - Carin Houbolt
- Department of Neurology, Center of Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
| | | | - Willem A van Gool
- Department of Neurology, Center of Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
| | - Diederik van de Beek
- Department of Neurology, Center of Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
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Heneka MT, Golenbock DT, Latz E. Innate immunity in Alzheimer's disease. Nat Immunol 2015; 16:229-36. [PMID: 25689443 DOI: 10.1038/ni.3102] [Citation(s) in RCA: 541] [Impact Index Per Article: 60.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Accepted: 01/13/2015] [Indexed: 12/22/2022]
Abstract
Alzheimer's disease (AD) is the world's most common dementing illness, affecting over 150 million patients. Classically AD has been viewed as a neurodegenerative disease of the elderly, characterized by the extracellular deposition of misfolded amyloid-β (Aβ) peptide and the intracellular formation of neurofibrillary tangles. Only recently has neuroinflammation emerged as an important component of AD pathology. Experimental, genetic and epidemiological data now indicate a crucial role for activation of the innate immune system as a disease-promoting factor. The sustained formation and deposition of Aβ aggregates causes chronic activation of the immune system and disturbance of microglial clearance functions. Here we review advances in the molecular understanding of the inflammatory response in AD that point to novel therapeutic approaches for the treatment of this devastating disease.
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Affiliation(s)
- Michael T Heneka
- 1] Clinical Neuroscience, Department of Neurology, University of Bonn, Bonn, Germany. [2] Department of Medicine, Division of Infectious Diseases and Immunology, University of Massachusetts Medical School, Worcester, Massachusetts, USA. [3] German Center for Neurodegenerative Diseases, Bonn, Germany
| | - Douglas T Golenbock
- Department of Medicine, Division of Infectious Diseases and Immunology, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Eicke Latz
- 1] Department of Medicine, Division of Infectious Diseases and Immunology, University of Massachusetts Medical School, Worcester, Massachusetts, USA. [2] German Center for Neurodegenerative Diseases, Bonn, Germany. [3] Institute of Innate Immunology, University of Bonn, Bonn, Germany
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Systemic Lipopolysaccharide Administration-Induced Cognitive Impairments are Reversed by Erythropoietin Treatment in Mice. Inflammation 2015; 38:1949-58. [DOI: 10.1007/s10753-015-0175-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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71
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Li L, Sun Q, Li Y, Yang Y, Yang Y, Chang T, Man M, Zheng L. Overexpression of SIRT1 Induced by Resveratrol and Inhibitor of miR-204 Suppresses Activation and Proliferation of Microglia. J Mol Neurosci 2015; 56:858-867. [DOI: 10.1007/s12031-015-0526-5] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Accepted: 02/13/2015] [Indexed: 10/23/2022]
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72
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Anderson ST, Commins S, Moynagh PN, Coogan AN. Lipopolysaccharide-induced sepsis induces long-lasting affective changes in the mouse. Brain Behav Immun 2015; 43:98-109. [PMID: 25063709 DOI: 10.1016/j.bbi.2014.07.007] [Citation(s) in RCA: 129] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Revised: 07/04/2014] [Accepted: 07/10/2014] [Indexed: 12/27/2022] Open
Abstract
Post-septic encephalopathy is a poorly understood condition in survivors of sepsis that is characterised by cognitive and affective impairments. In this study we have sought to better understand this condition by undertaking a comprehensive behavioural and cognitive assessment of mice who had previously survived sepsis. Mice were treated with lipopolysaccharide (LPS; 5mg/kg) and one month after this assessed on a battery of tests. Post-septic animals were found to display significantly more immobility in the tail suspension test and show a significantly decreased sucrose preference. Acute fluoxetine treatment reversed the increase in immobility in the tail suspension test in post-septic animals. Post-septic animals also showed less overall exploratory behaviour in the novel object recognition task and also showed increased anxiety-like behaviour in the elevated plus maze. Post-septic mice did not show signs of cognitive impairment, as assessed in the Morris watermaze, the 8-arm radial maze or on preference for the novel object in the novel object recognition task. Immunohistochemical analysis revealed significant upregulation of the microglial marker CD-11b, F4/80 and IBA-1 in the hippocampus of post-septic animals, as well as significant downregulation of the plasticity-related immediate early gene products ARC and EGR1. We also observed a decrease in neural stem cell proliferation in the dentate gyrus of post-septic animals as judged by BrdU incorporation. Co-treatment with the NF-κB pathway inhibitor PDTC attenuated the long-lasting effects of LPS on most of the affected parameters, but not on neural stem cell proliferation. These results show that LPS-induced sepsis in the mouse is followed by long-lasting increases in depressive- and anxiety-like behaviours, as well as by changes in neuroinflammatory- and neural plasticity-associated factors, and that attenuation of the severity of sepsis by PDTC attenuates many of these effects.
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Affiliation(s)
- Seán T Anderson
- Department of Psychology, National University of Ireland Maynooth, County Kildare, Ireland
| | - Seán Commins
- Department of Psychology, National University of Ireland Maynooth, County Kildare, Ireland
| | - Paul N Moynagh
- Institute of Immunology, National University of Ireland Maynooth, County Kildare, Ireland
| | - Andrew N Coogan
- Department of Psychology, National University of Ireland Maynooth, County Kildare, Ireland.
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73
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Annane D, Sharshar T. Cognitive decline after sepsis. THE LANCET RESPIRATORY MEDICINE 2014; 3:61-9. [PMID: 25434614 DOI: 10.1016/s2213-2600(14)70246-2] [Citation(s) in RCA: 197] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The modern era of sepsis management is characterised by a growing number of patients who survive in the short term and are discharged from hospital. Increasing evidence suggests that these survivors exhibit long-term neurological sequelae, particularly substantial declines in cognitive function. The exact prevalence and outcomes of these neuropsychological sequelae are unclear. The mechanisms by which sepsis induces cognitive dysfunction probably include vascular injuries and neuroinflammation that are mediated by systemic metabolism disorders and overwhelming inflammation, a disrupted blood-brain barrier, oxidative stress, and severe microglial activation, particularly within the limbic system. Interventions targeting the blood-brain barrier, glial activation, and oxidative stress have shown promise in prevention of cognitive dysfunction in various experimental models of sepsis. The next step should be to translate these favourable effects into positive clinical results.
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Affiliation(s)
- Djillali Annane
- Department of Intensive Care Medicine, Raymond Poincaré Hospital, Assistance Publique-Hôpitaux de Paris, Garches, France; University of Versailles, Montigny le Bretonneux, France.
| | - Tarek Sharshar
- Department of Intensive Care Medicine, Raymond Poincaré Hospital, Assistance Publique-Hôpitaux de Paris, Garches, France; University of Versailles, Montigny le Bretonneux, France
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Schweighöfer H, Rummel C, Mayer K, Rosengarten B. Brain function in iNOS knock out or iNOS inhibited (l-NIL) mice under endotoxic shock. Intensive Care Med Exp 2014; 2:24. [PMID: 26266921 PMCID: PMC4513038 DOI: 10.1186/s40635-014-0024-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Accepted: 08/14/2014] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Microcirculatory dysfunction due to excessive nitric oxide production by the inducible nitric oxide synthase (iNOS) is often seen as a motor of sepsis-related organ dysfunction. Thus, blocking iNOS may improve organ function. Here, we investigated neuronal functional integrity in iNOS knock out (-/-) or l-NIL-treated wild-type (wt) animals in an endotoxic shock model. METHODS Four groups of each 10 male mice (28 to 32 g) were studied: wt, wt + lipopolysaccharide (LPS) (5 mg/kg body weight i.v.), iNOS(-/-) + LPS, wt + LPS + l-NIL (5 mg/kg body weight i.p. 30 min before LPS). Electric forepaw stimulation was performed before LPS/vehicle and then at fixed time points repeatedly up to 4.5 h. N1-P1 potential amplitudes as well as P1 latencies were calculated from EEG recordings. Additionally, cerebral blood flow was registered using laser Doppler. Blood gas parameters, mean arterial blood pressure, and glucose and lactate levels were obtained at the beginning and the end of experiments. Moreover, plasma IL-6, IL-10, CXCL-5, ICAM-1, neuron-specific enolase (NSE), and nitrate/nitrite levels were determined. RESULTS Decline in blood pressure, occurrence of cerebral hyperemia, acidosis, and increase in lactate levels were prevented in both iNOS-blocked groups. SEP amplitudes and NSE levels remained in the range of controls. Effects were related to a blocked nitrate/nitrite level increase whereas IL-6, ICAM-1, and IL-10 were similarly induced in all sepsis groups. Only CXCL-5 induction was lower in both iNOS-blocked groups. CONCLUSIONS Despite similar hyper-inflammatory responses, iNOS inhibition strategies appeared neurofunctionally protective possibly by stabilizing macro- as well as microcirculation. Overall, our data support modern sepsis guidelines recommending early prevention of microcirculatory failure.
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Affiliation(s)
- Hanna Schweighöfer
- Department of Neurology, Justus-Liebig-University Giessen, Klinikstrasse 33, 35392, Giessen, Germany,
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Fishbein-Kaminietsky M, Gafni M, Sarne Y. Ultralow doses of cannabinoid drugs protect the mouse brain from inflammation-induced cognitive damage. J Neurosci Res 2014; 92:1669-77. [DOI: 10.1002/jnr.23452] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2014] [Revised: 06/15/2014] [Accepted: 06/16/2014] [Indexed: 01/05/2023]
Affiliation(s)
- Miriam Fishbein-Kaminietsky
- The Adelson Center for the Biology of Addictive Diseases and The Mauerberger Chair in Neuropharmacology; Sackler Faculty of Medicine, Tel-Aviv University; Tel-Aviv Israel
| | - Mikhal Gafni
- The Adelson Center for the Biology of Addictive Diseases and The Mauerberger Chair in Neuropharmacology; Sackler Faculty of Medicine, Tel-Aviv University; Tel-Aviv Israel
| | - Yosef Sarne
- The Adelson Center for the Biology of Addictive Diseases and The Mauerberger Chair in Neuropharmacology; Sackler Faculty of Medicine, Tel-Aviv University; Tel-Aviv Israel
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Iwasa T, Matsuzaki T, Tungalagsuvd A, Munkhzaya M, Kawami T, Niki H, Kato T, Kuwahara A, Uemura H, Yasui T, Irahara M. Hypothalamic Kiss1 and RFRP gene expressions are changed by a high dose of lipopolysaccharide in female rats. Horm Behav 2014; 66:309-16. [PMID: 24952104 DOI: 10.1016/j.yhbeh.2014.06.007] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Revised: 05/29/2014] [Accepted: 06/06/2014] [Indexed: 11/22/2022]
Abstract
Reproductive function is suppressed by several types of stress. Hypothalamic kisspeptin, which is a product of the Kiss1 gene, and GnIH/RFRP have pivotal roles in the regulation of GnRH and gonadotropins through their receptors Kiss1r and GPR147 in many species. However, alterations of these factors under stress conditions have not been fully evaluated. This study investigated the mechanisms of immune stress-induced reproductive dysfunction, especially focusing on the changes of Kiss1 and RFRP gene expression. Serum LH levels and hypothalamic Kiss1 and GnRH mRNA levels were decreased, while hypothalamic RFRP and GPR147 mRNA levels were increased by administration of a high dose of LPS (5mg/kg) in both ovariectomized and gonadal intact female rats. In this condition, Kiss1 and/or RFRP mRNA levels were positively and negatively correlated with GnRH expression, respectively. In contrast, hypothalamic Kiss1, RFRP, and GPR147 mRNA levels were not changed by administration of a moderate dose of LPS (500μg/kg) in ovariectomized rats. Rats with high-dose LPS injection showed more prolonged fever responses and severe anorexia compared with rats with moderate-dose LPS injection, indicating that more energy was used for the immune response in the former. These results suggest that the underlying mechanisms of dysfunction of gonadotropin secretion are changed according to the severity of immune stress, and that changes of some reserved factors, such as kisspeptin and RFRP, begin to participate in the suppression of GnRH and gonadotropin in severe conditions. As reproduction needs a large amount of energy, dysfunction of gonadotropin secretion under immune stress may be a biophylatic mechanism by which more energy is saved for the immune response.
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Affiliation(s)
- Takeshi Iwasa
- Department of Obstetrics and Gynecology, The University of Tokushima Graduate School, Institute of Health Biosciences, 3-18-15 Kuramoto-Cho, Tokushima 770-8503, Japan.
| | - Toshiya Matsuzaki
- Department of Obstetrics and Gynecology, The University of Tokushima Graduate School, Institute of Health Biosciences, 3-18-15 Kuramoto-Cho, Tokushima 770-8503, Japan
| | - Altankhuu Tungalagsuvd
- Department of Obstetrics and Gynecology, The University of Tokushima Graduate School, Institute of Health Biosciences, 3-18-15 Kuramoto-Cho, Tokushima 770-8503, Japan
| | - Munkhsaikhan Munkhzaya
- Department of Obstetrics and Gynecology, The University of Tokushima Graduate School, Institute of Health Biosciences, 3-18-15 Kuramoto-Cho, Tokushima 770-8503, Japan
| | - Takako Kawami
- Department of Obstetrics and Gynecology, The University of Tokushima Graduate School, Institute of Health Biosciences, 3-18-15 Kuramoto-Cho, Tokushima 770-8503, Japan
| | - Hirobumi Niki
- Department of Obstetrics and Gynecology, The University of Tokushima Graduate School, Institute of Health Biosciences, 3-18-15 Kuramoto-Cho, Tokushima 770-8503, Japan
| | - Takeshi Kato
- Department of Obstetrics and Gynecology, The University of Tokushima Graduate School, Institute of Health Biosciences, 3-18-15 Kuramoto-Cho, Tokushima 770-8503, Japan
| | - Akira Kuwahara
- Department of Obstetrics and Gynecology, The University of Tokushima Graduate School, Institute of Health Biosciences, 3-18-15 Kuramoto-Cho, Tokushima 770-8503, Japan
| | - Hirokazu Uemura
- Department of Preventive Medicine, Institute of Health Biosciences, The University of Tokushima Graduate School, Japan
| | - Toshiyuki Yasui
- Department of Reproductive Technology, Institute of Health Biosciences, The University of Tokushima Graduate School, Japan
| | - Minoru Irahara
- Department of Obstetrics and Gynecology, The University of Tokushima Graduate School, Institute of Health Biosciences, 3-18-15 Kuramoto-Cho, Tokushima 770-8503, Japan
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Pierrakos C, Attou R, Decorte L, Kolyviras A, Malinverni S, Gottignies P, Devriendt J, De Bels D. Transcranial Doppler to assess sepsis-associated encephalopathy in critically ill patients. BMC Anesthesiol 2014; 14:45. [PMID: 24944522 PMCID: PMC4061318 DOI: 10.1186/1471-2253-14-45] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Accepted: 06/03/2014] [Indexed: 01/08/2023] Open
Abstract
Background Transcranial Doppler can detect cerebral perfusion alteration in septic patients. We correlate static Transcranial Doppler findings with clinical signs of sepsis-associated encephalopathy. Methods Forty septic patients were examined with Transcranial Doppler on the first and third day of sepsis diagnosis. The pulsatility index (PI) and cerebral blood flow index (CBFi) were calculated by blood velocity in the middle cerebral artery (cm/sec). Patients underwent a daily cognitive assessment with the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) test. Results Twenty-one patients (55%) were found to present confusion. The majority of the patients presented a PI > 1.1 (76%). PI on the first day (but not the third day) could predict a positive CAM-ICU test in septic patients (PI cut-off: 1.3, AUC: 0.905, p < 0.01, sensitivity: 95%, specificity: 88%, AUC: 0.618, p = 0.24). Multivariable analysis showed that PI on the first day is related to a positive CAM-ICU test independent of age and APACHE II score (OR: 5.6, 95% CI: 1.1-29, p = 0.03). A decrease of the PI on the third day was observed in the group that presented initially high PI (>1.3) (2.2 ± 0.71 vs. 1.81 ± 0.64; p = 0.02). On the other hand, an increase in PI was observed in the other patients (1.01 ± 0.15 vs. 1.58 ± 0.57; p < 0.01). On only the first day, the mean blood velocity in the middle cerebral artery and CBFi were found to be lower in those patients with a high initial PI (36 ± 21 vs. 62 ± 28 cm/sec; p < 0.01, 328 ± 101 vs. 581 ± 108; p < 0.01, respectively). Conclusions Cerebral perfusion disturbance observed with Transcranial Doppler could explain clinical symptoms of sepsis-associated encephalopathy.
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Affiliation(s)
- Charalampos Pierrakos
- Departments of Intensive Care, Brugmann University Hospital, Université Libre de Bruxelles, Place Van Gehuchten 4, 1020 Bruxelles, Belgium
| | - Rachid Attou
- Departments of Intensive Care, Brugmann University Hospital, Université Libre de Bruxelles, Place Van Gehuchten 4, 1020 Bruxelles, Belgium
| | - Laurence Decorte
- Departments of Geriatrics, Brugmann University Hospital, Université Libre de Bruxelles, Bruxelles, Belgium
| | - Athanasios Kolyviras
- Departments of Intensive Care, Brugmann University Hospital, Université Libre de Bruxelles, Place Van Gehuchten 4, 1020 Bruxelles, Belgium
| | - Stefano Malinverni
- Departments of Intensive Care, Brugmann University Hospital, Université Libre de Bruxelles, Place Van Gehuchten 4, 1020 Bruxelles, Belgium
| | - Philippe Gottignies
- Departments of Intensive Care, Brugmann University Hospital, Université Libre de Bruxelles, Place Van Gehuchten 4, 1020 Bruxelles, Belgium
| | - Jacques Devriendt
- Departments of Intensive Care, Brugmann University Hospital, Université Libre de Bruxelles, Place Van Gehuchten 4, 1020 Bruxelles, Belgium
| | - David De Bels
- Departments of Intensive Care, Brugmann University Hospital, Université Libre de Bruxelles, Place Van Gehuchten 4, 1020 Bruxelles, Belgium
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78
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Dal-Pizzol F, Tomasi CD, Ritter C. Septic encephalopathy: does inflammation drive the brain crazy? REVISTA BRASILEIRA DE PSIQUIATRIA 2014; 36:251-8. [DOI: 10.1590/1516-4446-2013-1233] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Accepted: 11/11/2013] [Indexed: 11/21/2022]
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80
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Gyoneva S, Davalos D, Biswas D, Swanger SA, Garnier-Amblard E, Loth F, Akassoglou K, Traynelis SF. Systemic inflammation regulates microglial responses to tissue damage in vivo. Glia 2014; 62:1345-60. [PMID: 24807189 DOI: 10.1002/glia.22686] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Revised: 04/07/2014] [Accepted: 04/18/2014] [Indexed: 11/09/2022]
Abstract
Microglia, the resident immune cells of the central nervous system, exist in either a "resting" state associated with physiological tissue surveillance or an "activated" state in neuroinflammation. We recently showed that ATP is the primary chemoattractor to tissue damage in vivo and elicits opposite effects on the motility of activated microglia in vitro through activation of adenosine A2A receptors. However, whether systemic inflammation affects microglial responses to tissue damage in vivo remains largely unknown. Using in vivo two-photon imaging of mice, we show that injection of lipopolysaccharide (LPS) at levels that can produce both clear neuroinflammation and some features of sepsis significantly reduced the rate of microglial response to laser-induced ablation injury in vivo. Under proinflammatory conditions, microglial processes initially retracted from the ablation site, but subsequently moved toward and engulfed the damaged area. Analyzing the process dynamics in 3D cultures of primary microglia indicated that only A2A , but not A1 or A3 receptors, mediate process retraction in LPS-activated microglia. The A2A receptor antagonists caffeine and preladenant reduced adenosine-mediated process retraction in activated microglia in vitro. Finally, administration of preladenant before induction of laser ablation in vivo accelerated the microglial response to injury following systemic inflammation. The regulation of rapid microglial responses to sites of injury by A2A receptors could have implications for their ability to respond to the neuronal death occurring under conditions of neuroinflammation in neurodegenerative disorders.
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Affiliation(s)
- Stefka Gyoneva
- Department of Pharmacology, Emory University School of Medicine, Atlanta, Georgia
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81
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Vasconcelos AR, Yshii LM, Viel TA, Buck HS, Mattson MP, Scavone C, Kawamoto EM. Intermittent fasting attenuates lipopolysaccharide-induced neuroinflammation and memory impairment. J Neuroinflammation 2014; 11:85. [PMID: 24886300 PMCID: PMC4041059 DOI: 10.1186/1742-2094-11-85] [Citation(s) in RCA: 132] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2013] [Accepted: 04/21/2014] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Systemic bacterial infections often result in enduring cognitive impairment and are a risk factor for dementia. There are currently no effective treatments for infection-induced cognitive impairment. Previous studies have shown that intermittent fasting (IF) can increase the resistance of neurons to injury and disease by stimulating adaptive cellular stress responses. However, the impact of IF on the cognitive sequelae of systemic and brain inflammation is unknown. METHODS Rats on IF for 30 days received 1 mg/kg of lipopolysaccharide (LPS) or saline intravenously. Half of the rats were subjected to behavioral tests and the other half were euthanized two hours after LPS administration and the hippocampus was dissected and frozen for analyses. RESULTS Here, we report that IF ameliorates cognitive deficits in a rat model of sepsis by a mechanism involving NF-κB activation, suppression of the expression of pro-inflammatory cytokines, and enhancement of neurotrophic support. Treatment of rats with LPS resulted in deficits in cognitive performance in the Barnes maze and inhibitory avoidance tests, without changing locomotor activity, that were ameliorated in rats that had been maintained on the IF diet. IF also resulted in reduced levels of mRNAs encoding the LPS receptor TLR4 and inducible nitric oxide synthase (iNOS) in the hippocampus. Moreover, IF prevented LPS-induced elevation of IL-1α, IL-1β and TNF-α levels, and prevented the LPS-induced reduction of BDNF levels in the hippocampus. IF also significantly attenuated LPS-induced elevations of serum IL-1β, IFN-γ, RANTES, TNF-α and IL-6 levels. CONCLUSIONS Taken together, our results suggest that IF induces adaptive responses in the brain and periphery that can suppress inflammation and preserve cognitive function in an animal model of systemic bacterial infection.
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Affiliation(s)
| | | | | | | | | | - Cristoforo Scavone
- Department of Pharmacology, Institute of Biomedical Science, University of São Paulo, São Paulo 05508-900, Brazil.
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Lindlau A, Widmann CN, Putensen C, Jessen F, Semmler A, Heneka MT. Predictors of hippocampal atrophy in critically ill patients. Eur J Neurol 2014; 22:410-5. [PMID: 24724819 DOI: 10.1111/ene.12443] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2013] [Accepted: 03/06/2014] [Indexed: 12/20/2022]
Abstract
BACKGROUND AND PURPOSE Hippocampal atrophy is presumably one morphological sign of critical illness encephalopathy; however, predictors have not yet been determined. METHODS The data for this report derived from patients treated at the intensive care units (ICUs) of the University Hospital in Bonn in the years 2004-2006. These patients underwent structural magnetic resonance imaging 6-24 months after discharge. Volumes (intracranial, whole brain, white matter, grey matter, cerebral spinal fluid, bilateral hippocampus) were compared with healthy controls. Pro-inflammatory parameters and ICU scoring systems were explored in conjunction with brain volumes. Cut-scores were defined to differentiate patients with high from those with low inflammatory response. RESULTS Hippocampal and white matter volume were reduced in critically ill patients compared with healthy controls. Procalcitonin showed a very strong correlation (r = -0.903, P = 0.01) and interleukin-6 a moderate correlation (r = -0.538, P = 0.031) with hippocampal volume, but not with other brain volumes. C-reactive protein was linked to grey matter volume. There was no correlation with systemic inflammatory response syndrome criteria (body temperature, heart rate, respiratory rate, white blood cell count) or for hippocampal or whole brain volume. Furthermore, parameters representing severity of disease (APACHE II score, SOFA score, duration of stay and duration of mechanical ventilation) were not associated with hippocampal or other brain volumes. CONCLUSIONS This analysis suggests that high levels of procalcitonin and interleukin-6 in the blood serum of critically ill patients are associated with a high likelihood of hippocampal atrophy irrespective of the severity of disease measured by ICU scoring systems and other inflammatory parameters.
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Affiliation(s)
- A Lindlau
- Clinical Neuroscience Unit, Department of Neurology, University Hospital Bonn, Bonn, Germany
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83
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Anderson ST, O'Callaghan EK, Commins S, Coogan AN. Does prior sepsis alter subsequent circadian and sickness behaviour response to lipopolysaccharide treatment in mice? J Neural Transm (Vienna) 2013; 122 Suppl 1:S63-73. [PMID: 24337695 DOI: 10.1007/s00702-013-1124-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2013] [Accepted: 11/19/2013] [Indexed: 11/25/2022]
Abstract
Previous data has shown that prior history of immune challenge may affect central and behavioural responses to subsequent immune challenge, either leading to exaggerated responses via priming mechanisms or lessened responses via endotoxin tolerance. In this set of experiments we have examined how previously lipopolysaccharide (LPS)-induced sepsis shapes the response to subsequent treatment with lower dose LPS. After treatment with LPS (5 mg/kg) or saline mice were allowed to recover for 3-4 months before being challenged with a lower dose of LPS (100 μg/kg) for assessment of sickness behaviours. Performance on the open field test and the tail suspension test was assessed, and no evidence was found that prior sepsis altered sickness or depressive-like behaviour following LPS treatment. We then examined the responsiveness of the circadian system of mice to LPS. We found that in control animals, LPS induced a significant phase delay of the behavioural rhythm and that this was not the case in post-septic animals (4-6 weeks after sepsis), indicating that prior sepsis alters the responsivity of the circadian system to subsequent immune challenge. We further assessed the induction of the immediate early genes c-Fos and EGR1 in the hippocampus and the suprachiasmatic nucleus (SCN; the master circadian pacemaker) by LPS in control or post-septic animals, and found that post-septic animals show elevated expression in the hippocampus but not the SCN. These data suggest that previous sepsis has some effect on behavioural and molecular responses to subsequent immune challenge in mice.
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Affiliation(s)
- Sean T Anderson
- Department of Psychology, National University of Ireland Maynooth, County Kildare, Ireland
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84
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Bioenergetics, mitochondrial dysfunction, and oxidative stress in the pathophysiology of septic encephalopathy. Shock 2013; 39 Suppl 1:10-6. [PMID: 23481496 DOI: 10.1097/shk.0b013e31828fade1] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Sepsis is a major cause of mortality and morbidity in intensive care units. Acute and long-term brain dysfunctions have been demonstrated both in experimental models and septic patients. Sepsis-associated encephalopathy is an early and frequent manifestation but is underdiagnosed, because of the absence of specific biomarkers and of confounding factors such as sedatives used in the intensive care unit. Sepsis-associated encephalopathy may have acute and long-term consequences including development of autonomic dysfunction, delirium, and cognitive impairment. The mechanisms of sepsis-associated encephalopathy involve mitochondrial and vascular dysfunctions, oxidative stress, neurotransmission disturbances, inflammation, and cell death. Here we review specific evidence that links bioenergetics, mitochondrial dysfunction, and oxidative stress in the setting of brain dysfunctions associated to sepsis.
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85
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Cherry JD, Williams JP, O'Banion MK, Olschowka JA. Thermal injury lowers the threshold for radiation-induced neuroinflammation and cognitive dysfunction. Radiat Res 2013; 180:398-406. [PMID: 24059681 DOI: 10.1667/rr3363.1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The consequences of radiation exposure alone are relatively well understood, but in the wake of events such as the World War II nuclear detonations and accidents such as Chernobyl, other critical factors have emerged that can substantially affect patient outcome. For example, ~70% of radiation victims from Hiroshima and Nagasaki received some sort of additional traumatic injury, the most common being thermal burn. Animal data has shown that the addition of thermal insult to radiation results in increased morbidity and mortality. To explore possible synergism between thermal injury and radiation on brain, C57BL/6J female mice were exposed to either 0 or 5 Gy whole-body gamma irradiation. Irradiation was immediately followed by a 10% total-body surface area full thickness thermal burn. Mice were sacrificed 6 h, 1 week or 6 month post-injury and brains and plasma were harvested for histology, mRNA analysis and cytokine ELISA. Plasma analysis revealed that combined injury synergistically upregulates IL-6 at acute time points. Additionally, at 6 h, combined injury resulted in a greater upregulation of the vascular marker, ICAM-1 and TNF-α mRNA. Enhanced activation of glial cells was also observed by CD68 and Iba1 immunohistochemistry at all time points. Additionally, doublecortin staining at 6 months showed reduced neurogenesis in all injury conditions. Finally, using a novel object recognition test, we observed that only mice with combined injury had significant learning and memory deficits. These results demonstrate that thermal injury lowers the threshold for radiation-induced neuroinflammation and long-term cognitive dysfunction.
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Affiliation(s)
- Jonathan D Cherry
- a Department of Pathology and Laboratory Medicine, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642
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86
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Wang GB, Ni YL, Zhou XP, Zhang WF. The AKT/mTOR pathway mediates neuronal protective effects of erythropoietin in sepsis. Mol Cell Biochem 2013; 385:125-32. [PMID: 24057122 DOI: 10.1007/s11010-013-1821-5] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2013] [Accepted: 09/13/2013] [Indexed: 12/14/2022]
Abstract
Sepsis is one of the most common causes of mortality in intensive care units. Although sepsis-associated encephalopathy (SAE) is reported to be a leading manifestation of sepsis, its pathogenesis remains to be elucidated. In this study, we investigated whether exogenous recombinant human erythropoietin (rhEPO) could protect brain from neuronal apoptosis in the model of SAE. We showed that application of rhEPO enhanced Bcl-2, decreased Bad in lipopolysaccharide treated neuronal cultures, and improved neuronal apoptosis in hippocampus of cecal ligation and peroration rats. We also found that rhEPO increased the expression of phosphorylated AKT, and the antiapoptotic role of rhEPO could be abolished by phosphoinositide 3-kinase (PI3K)/AKT inhibitor LY294002 or SH-5. In addition, systemic sepsis inhibited the hippocampal-phosphorylated mammalian target of rapamycin (mTOR) and p70S6K (downstream substrates of PKB/AKT signaling), which were restored by administration of exogenous rhEPO. Moreover, treatment with mTOR-signaling inhibitor rapamycin or transfection of mTOR siRNA reversed the neuronal protective effects of rhEPO. Finally, exogenous rhEPO rescued the emotional and spatial cognitive defects without any influence on locomotive activity. These results illustrated that exogenous rhEPO improves brain dysfunction by reducing neuronal apoptosis, and AKT/mTOR signaling is likely to be involved in this process. Application of rhEPO may serve as a potential therapy for the treatment of SAE.
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Affiliation(s)
- Guo-Bin Wang
- Department of Surgical Intensive Care Unit, The First Affiliated Hospital, Medical College, Zhejiang University, Qingchun Road 79, Hangzhou, 310003, People's Republic of China
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Stubbs DJ, Yamamoto AK, Menon DK. Imaging in sepsis-associated encephalopathy--insights and opportunities. Nat Rev Neurol 2013; 9:551-61. [PMID: 23999468 DOI: 10.1038/nrneurol.2013.177] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Sepsis-associated encephalopathy (SAE) refers to a clinical spectrum of acute neurological dysfunction that arises in the context of sepsis. Although the pathophysiology of SAE is incompletely understood, it is thought to involve endothelial activation, blood-brain barrier leakage, inflammatory cell migration, and neuronal loss with neurotransmitter imbalance. SAE is associated with a high risk of mortality. Imaging studies using MRI and CT have demonstrated changes in the brains of patients with SAE that are also seen in disorders such as stroke. Next-generation imaging techniques such as magnetic resonance spectroscopy, diffusion tensor imaging and PET, as well as experimental imaging modalities, provide options for early identification of patients with SAE, and could aid in identification of pathophysiological processes that represent possible therapeutic targets. In this Review, we explore the recent literature on imaging in SAE, relating the findings of these studies to pathological data and experimental studies to obtain insights into the pathophysiology of sepsis-associated neurological dysfunction. Furthermore, we suggest how novel imaging technologies can be used for early-stage proof-of-concept and proof-of-mechanism translational studies, which may help to improve diagnosis in SAE.
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Affiliation(s)
- Daniel J Stubbs
- Division of Anaesthesia, Department of Medicine, University of Cambridge, Addenbrooke's Hospital, Hills Road, Cambridge CB2 2QQ, UK
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Acute Brain Inflammation and Oxidative Damage Are Related to Long-Term Cognitive Deficits and Markers of Neurodegeneration in Sepsis-Survivor Rats. Mol Neurobiol 2013; 49:380-5. [DOI: 10.1007/s12035-013-8526-3] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2013] [Accepted: 07/30/2013] [Indexed: 01/05/2023]
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Adam N, Kandelman S, Mantz J, Chrétien F, Sharshar T. Sepsis-induced brain dysfunction. Expert Rev Anti Infect Ther 2013; 11:211-21. [PMID: 23409826 DOI: 10.1586/eri.12.159] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Systemic infection is often revealed by or associated with brain dysfunction, which is characterized by alteration of consciousness, ranging from delirium to coma, seizure or focal neurological signs. Its pathophysiology involves an ischemic process, secondary to impairment of cerebral perfusion and its determinants and a neuroinflammatory process that includes endothelial activation, alteration of the blood-brain barrier and passage of neurotoxic mediators. Microcirculatory dysfunction is common to these two processes. This brain dysfunction is associated with increased mortality, morbidity and long-term cognitive disability. Its diagnosis relies essentially on neurological examination that can lead to specific investigations, including electrophysiological testing or neuroimaging. In practice, cerebrospinal fluid analysis is indisputably required when meningitis is suspected. Hepatic, uremic or respiratory encephalopathy, metabolic disturbances, drug overdose, sedative or opioid withdrawal, alcohol withdrawal delirium or Wernicke's encephalopathy are the main differential diagnoses. Currently, treatment consists mainly of controlling sepsis. The effects of insulin therapy and steroids need to be assessed. Various drugs acting on sepsis-induced blood-brain barrier dysfunction, brain oxidative stress and inflammation have been tested in septic animals but not yet in patients.
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Affiliation(s)
- Nicolas Adam
- General Intensive Care Unit, Raymond Poincaré Teaching Hospital, University of Versailles Saint-Quentin en Yvelines, 104 Boulevard Raymond Poincaré, 92380 Garches, France
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90
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Epigenetic modulation of neuronal apoptosis and cognitive functions in sepsis-associated encephalopathy. Neurol Sci 2013; 35:283-8. [PMID: 23925573 DOI: 10.1007/s10072-013-1508-4] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2013] [Accepted: 07/15/2013] [Indexed: 10/26/2022]
Abstract
Sepsis-associated encephalopathy (SAE), which associates with neuronal apoptosis and cognitive disorders, is a common complication of systemic sepsis. However, the mechanism involving its modulation remains to be elucidated. Recent studies showed that histone deacetylases (HDACs) were implicated in neurodegeneration and cognitive functions. The current study was designed to investigate whether septic brain is epigenetically modulated by HDACs, using cecal ligation and peroration (CLP) rats and primary hippocampal neuronal cultures. We found that hippocampal acetylated histone 3 (AcH3), acetylated histone 4 (AcH4), cytoplasmic HDAC4 and Bcl-XL were inhibited in septic brain. Hippocampal Bax and nuclear HDAC4 expressions were enhanced in CLP rats. Administration of HDACs inhibitor, trichostatin A (TSA) or suberoylanilide hydroxamic acid (SAHA) rescued the changes of Bcl-XL and Bax in vivo, and decreased apoptotic cells in vitro. In addition, HDAC4 shRNA transfection significantly enhanced AcH3, AcH4 and Bcl-XL, but suppressed Bax. Neuronal apoptosis was also reduced by transfection of HDAC4 shRNA. Furthermore, CLP rats exhibited significant spatial learning and memory deficits, which could be ameliorated by application of TSA or SAHA without influence on locomotive activity. These results reveal that epigenetic modulation is involved in septic brain, and the inhibition of HDACs may serve as a potential therapeutic approach for SAE treatment.
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Zheng Y, Lee S, Liang X, Wei S, Moon HG, Jin Y. Suppression of PTRF alleviates the polymicrobial sepsis induced by cecal ligation and puncture in mice. J Infect Dis 2013; 208:1803-12. [PMID: 23908488 DOI: 10.1093/infdis/jit364] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Sepsis and sepsis-associated organ failure are devastating conditions. Understanding the detailed cellular/molecular mechanisms involved in sepsis should lead to the identification of novel therapeutic targets. METHODS Cecal ligation and puncture (CLP) was used as a polymicrobial sepsis model in vivo to determine mortality and end-organ damage. Macrophages were adopted as the cellular model in vitro for mechanistic studies. RESULTS PTRF+/- mice survived longer and suffered less organ damage after CLP. Reductions in nitric oxide (NO) and iNOS biosynthesis were observed in plasma, macrophages, and vital organs in the PTRF+/- mice. Using an acute sepsis model after CLP, we found that iNOS-/- mice had a comparable level of survival as the PTRF+/- mice. Similarly, polymerase I transcript release factor (PTRF) deficiency resulted in decreased iNOS and NO/ROS production in macrophages in vitro. Mechanistically, lipopolysaccharide (LPS) enhanced the co-localization and interaction between PTRF and TLR4 in lipid rafts. Deletion of PTRF blocked formation of the TLR4/Myd88 complex after LPS. Consistent with this, lack of PTRF impaired the TLR4 signaling, as shown by the decreased p-JNK, p-ERK, and p-p38, which are upstream factors involved in iNOS transcription. CONCLUSION PTRF is a crucial regulator of TLR4 signaling in the development of sepsis.
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Affiliation(s)
- Yijie Zheng
- Division of Pulmonary and Critical Care, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
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Recombinant human erythropoietin attenuates neuronal apoptosis and cognitive defects via JAK2/STAT3 signaling in experimental endotoxemia. J Surg Res 2013; 183:304-12. [DOI: 10.1016/j.jss.2012.11.035] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2012] [Revised: 10/18/2012] [Accepted: 11/16/2012] [Indexed: 11/22/2022]
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93
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Abstract
Sepsis often is characterized by an acute brain dysfunction, which is associated with increased morbidity and mortality. Its pathophysiology is highly complex, resulting from both inflammatory and noninflammatory processes, which may induce significant alterations in vulnerable areas of the brain. Important mechanisms include excessive microglial activation, impaired cerebral perfusion, blood-brain-barrier dysfunction, and altered neurotransmission. Systemic insults, such as prolonged inflammation, severe hypoxemia, and persistent hyperglycemia also may contribute to aggravate sepsis-induced brain dysfunction or injury. The diagnosis of brain dysfunction in sepsis relies essentially on neurological examination and neurological tests, such as EEG and neuroimaging. A brain MRI should be considered in case of persistent brain dysfunction after control of sepsis and exclusion of major confounding factors. Recent MRI studies suggest that septic shock can be associated with acute cerebrovascular lesions and white matter abnormalities. Currently, the management of brain dysfunction mainly consists of control of sepsis and prevention of all aggravating factors, including metabolic disturbances, drug overdoses, anticholinergic medications, withdrawal syndromes, and Wernicke's encephalopathy. Modulation of microglial activation, prevention of blood-brain-barrier alterations, and use of antioxidants represent relevant therapeutic targets that may impact significantly on neurologic outcomes. In the future, investigations in patients with sepsis should be undertaken to reduce the duration of brain dysfunction and to study the impact of this reduction on important health outcomes, including functional and cognitive status in survivors.
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94
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Chronic mild stress modulates 5-HT1A and 5-HT2A receptor expression in the cerebellar cortex of NC/Nga atopic-like mice. Arch Dermatol Res 2013; 305:407-13. [PMID: 23440396 DOI: 10.1007/s00403-013-1325-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2012] [Revised: 02/03/2013] [Accepted: 02/06/2013] [Indexed: 01/09/2023]
Abstract
Atopic eczema symptoms may worsen due to stress. In the present study, the cerebellar cortex of the atopic-like mouse NC/Nga was studied regarding the effect of chronic mild stress on expression of two well-characterized serotonergic receptors (R), 5-HT1A and 5-HT2A. In total 24 mice were used. Sixteen of these mice were subjected to unpredictable stressors for 12 weeks, and 8 mice were used as controls. In order to evoke an eczema, a mite antigen was applied to 16 mice from week 9 of the experiment. Thus, three groups of mice, stressed eczematous (SE), non-stressed eczematous (NSE) and stressed control (SC), respectively, were obtained. The expression of the 5-HT1AR was analyzed using quantitative immunohistochemistry. For evaluation of 5-HT2AR a semi-quantitative technique was used, the cell density and signal intensity being measured. The highest average value for 5-HT1AR expression, in the Purkinje cells, was recorded in the NSE group, while the lowest average was in the SC group. 5-HT1AR expression differed significantly between the groups. The highest average value for density of 5-HT2AR positive Purkinje cells was evident in the SE group, while the lowest was in the SC group, this difference between groups also being statistically significant. In addition, the signal intensity was highest in the SE group, with a difference compared to the other groups. In conclusion, chronic mild stress modulates serotonergic receptor expressions in the cerebellar cortex of atopic-like mice.
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95
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Li L, Zhang J, Yang Y, Wang Q, Gao L, Yang Y, Chang T, Zhang X, Xiang G, Cao Y, Shi Z, Zhao M, Gao G. Single-wall carbon nanohorns inhibited activation of microglia induced by lipopolysaccharide through blocking of Sirt3. NANOSCALE RESEARCH LETTERS 2013; 8:100. [PMID: 23432919 PMCID: PMC3598862 DOI: 10.1186/1556-276x-8-100] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/29/2012] [Accepted: 01/20/2013] [Indexed: 06/01/2023]
Abstract
Single-wall carbon nanohorns (SWNHs) have been demonstrated to accumulate in cytotoxic levels within organs of various animal models and cell types, which emerge as a wide range of promising biomedical imaging. Septic encephalopathy (SE) is an early sign of sepsis and associated with an increased rate of morbidity and mortality. Microglia activation plays an important role in neuroinflammation, which contributes to neuronal damage. Inhibition of microglia activation may have therapeutic benefits, which can alleviate the progression of neurodegeneration. Therefore, we investigated the functional changes of mice microglia cell lines pre-treated with or without lipopolysaccharide (LPS) induced by SWNHs. To address this question, the research about direct role of SWNHs on the growth, proliferation, and apoptosis of microglia cell lines in mice (N9 and BV2) pre-treated with or without LPS had been performed. Our results indicate that the particle diameter of SWNHs in water is between 342 to 712 nm. The images in scanning electron microscope showed that SWNHs on polystyrene surface are individual particles. LPS induced activation of mice microglia, promoted its growth and proliferation, and inhibited its apoptosis. SWNHs inhibited proliferation, delayed mitotic entry, and promoted apoptosis of mice microglia cells. The effects followed gradually increasing cultured time and concentrations of SWNHs, especially in cells pre-treated with LPS. SWNHs induced a significantly increase in G1 phase and inhibition of S phase of mice microglia cells in a dose-manner dependent of SWNHs, especially in cells pre-treated with LPS. The transmission electron microscope images showed that individual spherical SWNH particles smaller than 100 nm in diameters were localized inside lysosomes of mice microglia cells. SWNHs inhibited mitotic entry, growth and proliferation of mice microglia cells, and promoted its apoptosis, especially in cells pre-treated with LPS. SWNHs inhibited expression of Sirt3 and energy metabolism related with Sirt3 in mice microglia cells in a dose-dependent manner, especially in cells pre-treated with LPS. The role of SWNHs on mice microglia was implicating Sirt3 and energy metabolism associated with it.
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Affiliation(s)
- Lihong Li
- Department of Neurosurgery, Tangdu Hospital, Fourth Military Medical University, 710038, Xi’an, China
| | - Jinqian Zhang
- Institute of Infectious Diseases, Beijing Ditan Hospital, Capital Medical University, 100015, Beijing, China
| | - Yang Yang
- Department of Neurosurgery, Tangdu Hospital, Fourth Military Medical University, 710038, Xi’an, China
| | - Qiang Wang
- Department of Neurosurgery, Tangdu Hospital, Fourth Military Medical University, 710038, Xi’an, China
| | - Li Gao
- Department of Neurosurgery, Tangdu Hospital, Fourth Military Medical University, 710038, Xi’an, China
| | - Yanlong Yang
- Department of Neurosurgery, Tangdu Hospital, Fourth Military Medical University, 710038, Xi’an, China
| | - Tao Chang
- Department of Neurosurgery, Tangdu Hospital, Fourth Military Medical University, 710038, Xi’an, China
| | - Xingye Zhang
- Department of Neurosurgery, Tangdu Hospital, Fourth Military Medical University, 710038, Xi’an, China
| | - Guoan Xiang
- Department of General Surgery, the Second People’s Hospital of Guangdong Province, 510515, Guangzhou, China
| | - Yongmei Cao
- International Mongolian Medical Hospital of Inner Mongolia, 010065, Hohhot, China
| | - Zujin Shi
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, 100871, Beijing, China
| | - Ming Zhao
- Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University, 100191, Beijing, China
| | - Guodong Gao
- Department of Neurosurgery, Tangdu Hospital, Fourth Military Medical University, 710038, Xi’an, China
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O'Callaghan EK, Anderson ST, Moynagh PN, Coogan AN. Long-lasting effects of sepsis on circadian rhythms in the mouse. PLoS One 2012; 7:e47087. [PMID: 23071720 PMCID: PMC3469504 DOI: 10.1371/journal.pone.0047087] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2012] [Accepted: 09/07/2012] [Indexed: 12/26/2022] Open
Abstract
Daily patterns of activity and physiology are termed circadian rhythms and are driven primarily by an endogenous biological timekeeping system, with the master clock located in the suprachiasmatic nucleus. Previous studies have indicated reciprocal relationships between the circadian and the immune systems, although to date there have been only limited explorations of the long-term modulation of the circadian system by immune challenge, and it is to this question that we addressed ourselves in the current study. Sepsis was induced by peripheral treatment with lipopolysaccharide (5 mg/kg) and circadian rhythms were monitored following recovery. The basic parameters of circadian rhythmicity (free-running period and rhythm amplitude, entrainment to a light/dark cycle) were unaltered in post-septic animals compared to controls. Animals previously treated with LPS showed accelerated re-entrainment to a 6 hour advance of the light/dark cycle, and showed larger phase advances induced by photic stimulation in the late night phase. Photic induction of the immediate early genes c-FOS, EGR-1 and ARC was not altered, and neither was phase-shifting in response to treatment with the 5-HT-1a/7 agonist 8-OH-DPAT. Circadian expression of the clock gene product PER2 was altered in the suprachiasmatic nucleus of post-septic animals, and PER1 and PER2 expression patterns were altered also in the hippocampus. Examination of the suprachiasmatic nucleus 3 months after treatment with LPS showed persistent upregulation of the microglial markers CD-11b and F4/80, but no changes in the expression of various neuropeptides, cytokines, and intracellular signallers. The effects of sepsis on circadian rhythms does not seem to be driven by cell death, as 24 hours after LPS treatment there was no evidence for apoptosis in the suprachiasmatic nucleus as judged by TUNEL and cleaved-caspase 3 staining. Overall these data provide novel insight into how septic shock exerts chronic effects on the mammalian circadian system.
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Affiliation(s)
- Emma K. O'Callaghan
- Department of Psychology, National University of Ireland Maynooth, Maynooth, County Kildare, Republic of Ireland
| | - Sean T. Anderson
- Department of Psychology, National University of Ireland Maynooth, Maynooth, County Kildare, Republic of Ireland
| | - Paul N. Moynagh
- Institute of Immunology, National University of Ireland Maynooth, Maynooth, County Kildare, Republic of Ireland
| | - Andrew N. Coogan
- Department of Psychology, National University of Ireland Maynooth, Maynooth, County Kildare, Republic of Ireland
- * E-mail:
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Methylalpinumisoflavone Inhibits Lipopolysaccharide-Induced Inflammation in Microglial Cells by the NF-kappaB and MAPK Signaling Pathway. Phytother Res 2012; 26:1948-56. [DOI: 10.1002/ptr.4810] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2011] [Revised: 07/08/2012] [Accepted: 07/23/2012] [Indexed: 01/19/2023]
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98
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Cunningham C. Microglia and neurodegeneration: the role of systemic inflammation. Glia 2012; 61:71-90. [PMID: 22674585 DOI: 10.1002/glia.22350] [Citation(s) in RCA: 549] [Impact Index Per Article: 45.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2012] [Accepted: 04/17/2012] [Indexed: 01/11/2023]
Abstract
It is well accepted that CNS inflammation has a role in the progression of chronic neurodegenerative disease, although the mechanisms through which this occurs are still unclear. The inflammatory response during most chronic neurodegenerative disease is dominated by the microglia and mechanisms by which these cells contribute to neuronal damage and degeneration are the subject of intense study. More recently it has emerged that systemic inflammation has a significant role to play in the progression of these diseases. Well-described adaptive pathways exist to transduce systemic inflammatory signals to the brain, but activation of these pathways appears to be deleterious to the brain if the acute insult is sufficiently robust, as in severe sepsis, or sufficiently prolonged, as in repeated stimulation with robust doses of inflammogens such as lipopolysaccharide (LPS). Significantly, moderate doses of inflammogens produce new pathology in the brain and exacerbate or accelerate features of disease when superimposed upon existing pathology or in the context of genetic predisposition. It is now apparent in multiple chronic disease states, and in ageing, that microglia are primed by prior pathology, or by genetic predisposition, to respond more vigorously to subsequent inflammatory stimulation, thus transforming an adaptive CNS inflammatory response to systemic inflammation, into one that has deleterious consequences for the individual. In this review, the preclinical and clinical evidence supporting a significant role for systemic inflammation in chronic neurodegenerative diseases will be discussed. Mechanisms by which microglia might effect neuronal damage and dysfunction, as a consequence of systemic stimulation, will be highlighted.
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Affiliation(s)
- Colm Cunningham
- School of Biochemistry and Immunology and Trinity College Institute of Neuroscience, Trinity College, Dublin, Ireland.
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99
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Bossù P, Cutuli D, Palladino I, Caporali P, Angelucci F, Laricchiuta D, Gelfo F, De Bartolo P, Caltagirone C, Petrosini L. A single intraperitoneal injection of endotoxin in rats induces long-lasting modifications in behavior and brain protein levels of TNF-α and IL-18. J Neuroinflammation 2012; 9:101. [PMID: 22642744 PMCID: PMC3444884 DOI: 10.1186/1742-2094-9-101] [Citation(s) in RCA: 110] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2011] [Accepted: 05/29/2012] [Indexed: 11/10/2022] Open
Abstract
Background Systemic inflammation might cause neuronal damage and sustain neurodegenerative diseases and behavior impairment, with the participation of pro-inflammatory cytokines, like tumor necrosis factor (TNF)-α and interleukin (IL)-18. However, the potential contribution of these cytokines to behavioral impairment in the long-term period has not been fully investigated. Methods Wistar rats were treated with a single intraperitoneal injection of LPS (5 mg/kg) or vehicle. After 7 days and 10 months, the animal behavior was evaluated by testing specific cognitive functions, as mnesic, discriminative, and attentional functions, as well as anxiety levels. Contextually, TNF-α and IL-18 protein levels were measured by ELISA in defined brain regions (that is, frontal cortex, hippocampus, striatum, cerebellum, and hypothalamus). Results Behavioral testing demonstrated a specific and persistent cognitive impairment characterized by marked deficits in reacting to environment modifications, possibly linked to reduced motivational or attentional deficits. Concomitantly, LPS induced a TNF-α increase in the hippocampus and frontal cortex (from 7 days onward) and cerebellum (only at 10 months). Interestingly, LPS treatment enhanced IL-18 expression in these same areas only at 10 months after injection. Conclusions Overall, these results indicate that the chronic neuroinflammatory network elicited by systemic inflammation involves a persistent participation of TNF-α accompanied by a differently regulated contribution of IL-18. This leads to speculation that, though with still unclear mechanisms, both cytokines might take part in long-lasting modifications of brain functions, including behavioral alteration.
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Affiliation(s)
- Paola Bossù
- Clinical and Behavioral Neurology, IRCCS Fondazione Santa Lucia, Via Ardeatina 30600179, Rome, Italy.
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Wang G, Wang W, Zhao J, Ni Y, Zhou X, Zhang W. Ghrelin prevents neuronal apoptosis and cognitive impairments in sepsis-associated encephalopathy. Neuroreport 2011; 22:959-64. [DOI: 10.1097/wnr.0b013e32834d38ce] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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