RESUMO
OBJECTIVE: To evaluate the impact of faecal immunochemical testing (FIT) prioritisation to mitigate the impact of delays in the colorectal cancer (CRC) urgent diagnostic (2-week-wait (2WW)) pathway consequent from the COVID-19 pandemic. DESIGN: We modelled the reduction in CRC survival and life years lost resultant from per-patient delays of 2-6 months in the 2WW pathway. We stratified by age group, individual-level benefit in CRC survival versus age-specific nosocomial COVID-19-related fatality per referred patient undergoing colonoscopy. We modelled mitigation strategies using thresholds of FIT triage of 2, 10 and 150 µg Hb/g to prioritise 2WW referrals for colonoscopy. To construct the underlying models, we employed 10-year net CRC survival for England 2008-2017, 2WW pathway CRC case and referral volumes and per-day-delay HRs generated from observational studies of diagnosis-to-treatment interval. RESULTS: Delay of 2/4/6 months across all 11 266 patients with CRC diagnosed per typical year via the 2WW pathway were estimated to result in 653/1419/2250 attributable deaths and loss of 9214/20 315/32 799 life years. Risk-benefit from urgent investigatory referral is particularly sensitive to nosocomial COVID-19 rates for patients aged >60. Prioritisation out of delay for the 18% of symptomatic referrals with FIT >10 µg Hb/g would avoid 89% of these deaths attributable to presentational/diagnostic delay while reducing immediate requirement for colonoscopy by >80%. CONCLUSIONS: Delays in the pathway to CRC diagnosis and treatment have potential to cause significant mortality and loss of life years. FIT triage of symptomatic patients in primary care could streamline access to colonoscopy, reduce delays for true-positive CRC cases and reduce nosocomial COVID-19 mortality in older true-negative 2WW referrals. However, this strategy offers benefit only in short-term rationalisation of limited endoscopy services: the appreciable false-negative rate of FIT in symptomatic patients means most colonoscopies will still be required.
Assuntos
COVID-19 , Colonoscopia , Neoplasias Colorretais , Infecção Hospitalar/prevenção & controle , Diagnóstico Tardio , Sangue Oculto , Medição de Risco/métodos , COVID-19/epidemiologia , COVID-19/prevenção & controle , Colonoscopia/métodos , Colonoscopia/normas , Neoplasias Colorretais/diagnóstico , Neoplasias Colorretais/mortalidade , Procedimentos Clínicos , Diagnóstico Tardio/efeitos adversos , Diagnóstico Tardio/estatística & dados numéricos , Detecção Precoce de Câncer , Humanos , Imunoquímica/métodos , Controle de Infecções/métodos , Tábuas de Vida , Mortalidade , SARS-CoV-2 , Reino Unido/epidemiologiaRESUMO
OBJECTIVE: The concept of living with and beyond cancer is now emerging in policy and literature. Rather than viewing this notion simply as a linear timeline, developing an agreed understanding of the lived experience of people affected by cancer will aid the development of person-centred models of care. METHODS: A systematic review was conducted. The review question was "What does the term 'living with and beyond cancer' mean to people affected by cancer?" The protocol for the review was preregistered in the PROSPERO database (PROSPERO CRD42017059860). All included studies were qualitative, so narrative synthesis was used to integrate descriptions and definitions of living with and beyond cancer into an empirically based conceptual framework. RESULTS: Out of 2345 papers that were identified and 180 that were reviewed, a total of 73 papers were included. The synthesis yielded three interlinked themes: Adversity (realising cancer), Restoration (readjusting life with cancer), and Compatibility (reconciling cancer), resulting in the ARC framework. CONCLUSIONS: Three themes describe the experience of living with and beyond cancer: adversity, restoration, and compatibility. The ARC framework provides an empirically informed grounding for future research and practice in supportive cancer care for this population.
Assuntos
Sobreviventes de Câncer/psicologia , Neoplasias/psicologia , Qualidade de Vida/psicologia , Apoio Social , Atividades Cotidianas , Humanos , Narração , Fatores SocioeconômicosRESUMO
PURPOSE: Living with and beyond cancer is an increasingly common experience. While research is uncovering valuable individual experiences of those living with and beyond cancer, it has been argued that this idiographic approach is limited in outlook, reach and impact. This study contributes to the understanding of what it means to live with and beyond cancer by complementing idiographic knowledge with multiple perspectives from a group of participants who are living with and beyond cancer, to explore how individual experiences may be relevant to others. METHOD: Semi-structured interviews were conducted with people who had received treatment for breast (n = 6), prostate (n = 6) or colorectal cancer (n = 6). Data were analysed using interpretive phenomenological analysis. The early findings were then shared with a wider group of people who had received treatment for breast, prostate or colorectal cancer (n = 26) in six focus groups, to explore whether they had similar experiences. RESULTS: While individual accounts of living with and beyond cancer detail unique features specific to each person's experience, focus group discussions illustrated how participant life worlds interact and overlap. The findings identified thematic similarities within and between individual and group levels and across cancer types. Three super-ordinate themes describe the shared experience of living with and beyond cancer: i) the cancer shock, ii) managing cancer and getting through and iii) getting over cancer. CONCLUSIONS: A multiple perspective approach informs our understanding of shared experiences of living with and beyond cancer. This knowledge can be used to direct, design, and deliver relevant supportive cancer care.
Assuntos
Neoplasias Colorretais , Próstata , Neoplasias Colorretais/terapia , Grupos Focais , Humanos , Masculino , Pesquisa QualitativaRESUMO
Bacille Calmette-Guerin (BCG) is a potential tool in the control of Mycobacterium bovis in European badgers (Meles meles). A five year Test and Vaccinate or Remove (TVR) research intervention project commenced in 2014 using two BCG strains (BCG Copenhagen 1331 (Years 1-3/ BadgerBCG) and BCG Sofia SL2222 (Years 4-5). Badgers were recaptured around 9 weeks after the Year 5 vaccination and then again a year later. The Dual-Path Platform (DPP) Vet TB assay was used to detect serological evidence of M. bovis infection. Of the 48 badgers, 47 had increased Line 1 readings (MPB83 antigen) between the Year 5 vaccination and subsequent recapture. The number of BCG Sofia vaccinations influenced whether a badger tested positive to the recapture DPP VetTB assay Line 1 (p < 0.001) while the number of BadgerBCG vaccinations did not significantly affect recapture Line 1 results (p = 0.59). Line 1 relative light units (RLU) were more pronounced in tests run with sera than whole blood. The results from an in_house MPB83 ELISA results indicated that the WB DPP VetTB assay may not detect lower MPB83 IgG levels as well as the serum DPP VetTB assay. Changes in interferon gamma assay (IFN-γ) results were seen in 2019 with significantly increased CFP-10 and PPDB readings. Unlike BadgerBCG, BCG Sofia induces an immune response to MPB83 (the immune dominant antigen in M. bovis badger infection) that then affects the use of immunodiagnostic tests. The use of the DPP VetTB assay in recaptured BCG Sofia vaccinated badgers within the same trapping season is precluded and caution should be used in badgers vaccinated with BCG Sofia in previous years. The results suggest that the DPP VetTB assay can be used with confidence in badgers vaccinated with BadgerBCG as a single or repeated doses.
Assuntos
Mustelidae , Mycobacterium bovis , Tuberculose Bovina , Animais , Vacina BCG , Bovinos , Testes Imunológicos , Tuberculose Bovina/prevenção & controle , Vacinação/veterináriaRESUMO
The blockade of adenosine A(2A) receptors (A2AR) affords a robust neuroprotection in different noxious brain conditions. However, the mechanisms underlying this general neuroprotection are unknown. One possible mechanism could be the control of neuroinflammation that is associated with brain damage, especially because A2AR efficiently control peripheral inflammation. Thus, we tested if the intracerebroventricular injection of a selective A2AR antagonist (SCH58261) would attenuate the changes in the hippocampus triggered by intraperitoneal administration of lipopolysaccharide (LPS) that induces neuroinflammation through microglia activation. LPS administration triggers an increase in inflammatory mediators like interleukin-1ß that causes biochemical changes (p38 and c-jun N-terminal kinase phosphorylation and caspase 3 activation) contributing to neuronal dysfunction typified by decreased long-term potentiation, a form of synaptic plasticity. Long-term potentiation, measured 30 min after the tetanus, was significantly lower in LPS-treated rats compared with control-treated rats, while SCH58261 attenuated the LPS-induced change. The LPS-induced increases in phosphorylation of c-jun N-terminal kinase and p38 and activation of caspase 3 were also prevented by SCH58261. Significantly, SCH58261 also prevented the LPS-induced recruitment of activated microglial cells and the increase in interleukin-1ß concentration in the hippocampus, indicating that A2AR activation is a pivotal step in mediating the neuroinflammation triggered by LPS. These results indicate that A2AR antagonists prevent neuroinflammation and support the hypothesis that this mechanism might contribute for the ability of A2AR antagonists to control different neurodegenerative diseases known to involve neuroinflammation.
Assuntos
Hipocampo/patologia , Mediadores da Inflamação/fisiologia , Inibição Neural/fisiologia , Neurônios/patologia , Receptor A2A de Adenosina/fisiologia , Animais , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Mediadores da Inflamação/metabolismo , Lipopolissacarídeos/antagonistas & inibidores , Lipopolissacarídeos/fisiologia , Masculino , Plasticidade Neuronal/efeitos dos fármacos , Plasticidade Neuronal/fisiologia , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Ratos , Ratos Wistar , Receptor A2A de Adenosina/metabolismo , Resorcinóis/farmacologia , Resorcinóis/uso terapêutico , Sinapses/efeitos dos fármacos , Sinapses/metabolismo , Sinapses/patologiaRESUMO
The ability to accurately identify infected hosts is the cornerstone of effective disease control and eradication programs. In the case of bovine tuberculosis, accurately identifying infected individual animals has been challenging as all available tests exhibit limited discriminatory ability. Here we assess the utility of two serological tests (IDEXX Mycobacterium bovis Ab test and Enfer multiplex antibody assay) and assess their performance relative to skin test (Single Intradermal Comparative Cervical Tuberculin; SICCT), gamma-interferon (IFNγ) and post-mortem results in a Northern Ireland setting. Furthermore, we describe a case-study where one test was used in conjunction with statutory testing. Serological tests using samples taken prior to SICCT disclosed low proportions of animals as test positive (mean 3% positive), despite the cohort having high proportions with positive SICCT test under standard interpretation (121/921; 13%) or IFNγ (365/922; 40%) results. Furthermore, for animals with a post-mortem record (n = 286), there was a high proportion with TB visible lesions (27%) or with laboratory confirmed infection (25%). As a result, apparent sensitivities within this cohort was very low (≤15%), however the tests succeeded in achieving very high specificities (96-100%). During the case-study, 7/670 (1.04%) samples from SICCT negative animals from a large chronically infected herd were serology positive, with a further 17 animals being borderline positive (17/670; 2.54%). Nine of the borderline animals were voluntarily removed, none of which were found to be infected post-mortem (no lesions/bacteriology negative). One serology test negative animal was subsequently found to have lesions at slaughter with M. bovis confirmed in the laboratory.
Assuntos
Bovinos/sangue , Mycobacterium bovis/isolamento & purificação , Tuberculose Bovina/sangue , Tuberculose Bovina/diagnóstico , Animais , Bovinos/microbiologia , Feminino , Masculino , Irlanda do Norte/epidemiologia , Testes Sorológicos , Teste Tuberculínico , Tuberculose Bovina/epidemiologia , Tuberculose Bovina/microbiologiaRESUMO
Tuberculin skin tests remain widely used in the control of bovine tuberculosis (bTB) in cattle. Little is known about the rate of regression of tuberculin reactions after the comparative intradermal cervical test (CICT) in cattle. This study aimed to collect data to describe tuberculin regression in reactors following the CICT at 72 ± 4 h post injection. Reactors were also tested using the interferon gamma (IFN-γ) assay to establish if any pattern existed between these results and the CICT reaction regression. The data were derived from 108 herds, 112 herd-level CICTs and 1008 animals. A multivariable linear mixed model was built to explore the regression of the bovine tuberculin reaction over time and the influence of potential predictors. The results confirmed a proportional decline in the bovine tuberculin reaction occurred over time. The predictors in the final model demonstrated that regression of the tuberculin reaction differed between reactors according to their IFN-γ test results and whether visible lesions were present at slaughter. Follow-up measurement of tuberculin reactions and the serial use of the IFN-γ assay in large breakdowns has the potential to provide both a mechanism for quality assurance of the current CICT bTB surveillance and the identification of atypical breakdowns or reactors requiring further investigation.
Assuntos
Garantia da Qualidade dos Cuidados de Saúde , Teste Tuberculínico/veterinária , Tuberculose Bovina/diagnóstico , Animais , Bovinos , Interferon gama , Irlanda do Norte/epidemiologia , Teste Tuberculínico/métodos , Teste Tuberculínico/estatística & dados numéricos , Tuberculose Bovina/epidemiologia , Tuberculose Bovina/prevenção & controleRESUMO
While there is now substantial evidence that 5-HT(6) antagonism leads to significantly improved cognitive ability, the mechanism(s) and/or pathway(s) involved are poorly understood. We have evaluated the consequence of chronic administration of the 5-HT(6) receptor antagonists SB-271046 and SB-399885 on neural cell adhesion molecule polysialylation state (NCAM PSA), a neuroplastic mechanism necessary for memory consolidation. Quantitative analysis of NCAM PSA immunopositive neurons in the dentate gyrus of drug-treated animals revealed a dose-dependent increase in polysialylated cell frequency following treatment with both SB-271046 and SB-399885. These effects could not be attributed to increased neurogenesis, as no difference in the rate of bromodeoxyuridine incorporation was apparent between the control and drug-treated groups. A substantial increase in the frequency of polysialylated cells in layer II of the entorhinal and perirhinal cortices was also observed, brain regions not previously associated with neurogenesis. Chronic treatment with SB-271046 or SB-399885 also significantly increased the activation of dentate polysialylation that is specific to learning. This effect does not occur with other cognition-enhancing drugs, such as tacrine, and this action potentially differentiates 5-HT(6) receptor antagonism as an unique neuroplastic mechanism for cognitive processes which may slow or reverse age/neurodegenerative related memory deficits.
Assuntos
Giro Denteado/efeitos dos fármacos , Hipocampo/efeitos dos fármacos , Moléculas de Adesão de Célula Nervosa/farmacologia , Neurônios/metabolismo , Piperazinas/farmacologia , Receptores de Serotonina/efeitos dos fármacos , Antagonistas da Serotonina/farmacologia , Ácidos Siálicos/farmacologia , Sulfonamidas/farmacologia , Tiofenos/farmacologia , Animais , Antimetabólitos , Bromodesoxiuridina , Proliferação de Células/efeitos dos fármacos , Grânulos Citoplasmáticos/efeitos dos fármacos , Grânulos Citoplasmáticos/metabolismo , Giro Denteado/citologia , Relação Dose-Resposta a Droga , Córtex Entorrinal/citologia , Córtex Entorrinal/efeitos dos fármacos , Hipocampo/citologia , Imuno-Histoquímica , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Ratos , Ratos WistarRESUMO
Johne's disease (JD), is a fatal enteritis of animals caused by infection with Mycobacterium avium subspecies paratuberculosis (Map). Diagnosis of subclinical JD is problematic as test sensitivity is limited. Th1 responses to Map are activated early, thus detection of a cell-mediated response, indicated by measuring interferon gamma (IFN-γ) stimulated by mycobacterial antigens, may give the first indication of sub-clinical infection. Crude extracts of Map (PPDJ) have been used to detect the cell-mediated response in infected cattle. More specific, quantifiable antigens may improve test specificity and reproducibility. Map-specific proteins, MAP_3651c and MAP_0268c, raised a cell-mediated immune response in sub-clinically infected sheep. Results presented in this manuscript demonstrate these proteins elicit a cell-mediated response in experimental and natural infections of cattle. Individual ranked IFN-γ responses of experimentally infected calves to PPDJ showed a high, statistically significant association with ranked responses of recombinant Map antigens. Responses of infected animals were higher than the control group. Threshold values determined using data from an experimental infection were applied to naturally infected animals. Some animals exhibited responses above these threshold values. Responses to MAP_3651c on a farm categorised as high-risk for JD showed strong evidence (P<0.001) that responses were significantly different to lower-risk farms. The IGRA test may prove to be an additional tool for the diagnosis of JD, and inclusion of specific antigens a refinement however, understanding and interpretation of IGRA results remain challenging and further investigation will be required to determine whether the IGRA test can detect exposure and hence predict clinical JD.
Assuntos
Proteínas de Bactérias/metabolismo , Doenças dos Bovinos/imunologia , Imunidade Celular , Interferon gama/farmacologia , Paratuberculose/imunologia , Animais , Bovinos , Doenças dos Bovinos/microbiologia , Paratuberculose/microbiologia , Proteoma , Proteínas Recombinantes/metabolismoRESUMO
In utero exposure of rodents to valproic acid (VPA), a histone deacetylase (HDAC) inhibitor, has been proposed to induce an adult phenotype with behavioural characteristics reminiscent of those observed in autism spectrum disorder (ASD). We have evaluated the face validity of this model in terms of social cognition deficits which are a major core symptom of ASD. We employed the social approach avoidance paradigm as a measure of social reciprocity, detection of biological motion that is crucial to social interactions, and spatial learning as an indicator of dorsal stream processing of social cognition and found each parameter to be significantly impaired in Wistar rats with prior in utero exposure to VPA. We found no significant change in the expression of neural cell adhesion molecule polysialylation state (NCAM PSA), a measure of construct validity, but a complete inability to increase its glycosylation state which is necessary to mount the neuroplastic response associated with effective spatial learning. Finally, in all cases, we found chronic HDAC inhibition, with either pan-specific or HDAC1-3 isoform-specific inhibitors, to significantly ameliorate deficits in both social cognition and its associated neuroplastic response. We conclude that in utero exposure to VPA provides a robust animal model for the social cognitive deficits of ASD and a potential screen for the development of novel therapeutics for this condition.
Assuntos
Transtornos Globais do Desenvolvimento Infantil/tratamento farmacológico , Transtornos Cognitivos/prevenção & controle , Modelos Animais de Doenças , Histona Desacetilase 1/antagonistas & inibidores , Inibidores de Histona Desacetilases/uso terapêutico , Molécula L1 de Adesão de Célula Nervosa/metabolismo , Plasticidade Neuronal/efeitos dos fármacos , Ácidos Siálicos/metabolismo , Animais , Comportamento Animal/efeitos dos fármacos , Criança , Transtornos Globais do Desenvolvimento Infantil/metabolismo , Transtornos Globais do Desenvolvimento Infantil/patologia , Transtornos Globais do Desenvolvimento Infantil/fisiopatologia , Transtornos Cognitivos/etiologia , Giro Denteado/efeitos dos fármacos , Giro Denteado/metabolismo , Giro Denteado/patologia , Feminino , Histona Desacetilase 1/metabolismo , Inibidores de Histona Desacetilases/toxicidade , Humanos , Masculino , Terapia de Alvo Molecular , Proteínas do Tecido Nervoso/metabolismo , Neurônios/efeitos dos fármacos , Neurônios/enzimologia , Neurônios/metabolismo , Neurônios/patologia , Gravidez , Efeitos Tardios da Exposição Pré-Natal , Ratos , Ratos Wistar , Comportamento SocialRESUMO
Bovine tuberculosis (bTB) is diagnosed in naturally infected populations exposed to a wide variety of other pathogens. This study describes the cell-mediated immune responses of cattle exposed to Mycobacterium avium subspecies paratuberculosis (Map) and Mycobacterium avium subspecies avium with particular reference to routine antefmortem Mycobacterium bovis diagnostic tests. The IFN-γ released in response to stimulated blood was found to peak later in the Map-exposed group and was more sustained when compared to the Maa-exposed group. There was a very close correlation between the responses to the purified protein derivatives (PPD) used for stimulation (PPDa, PPDb, and PPDj) with PPDa and PPDj most closely correlated. On occasion, in the Map-infected cattle, PPDb-biased responses were seen compared to PPDa suggesting that some Map-infected cattle could be misclassified as M. bovis infected using this test with these reagents. This bias was not seen when PPDj was used. SICCT results were consistent with the respective infections and all calves would have been classed skin test negative.
RESUMO
There is significant interest in developing vaccines to control bovine tuberculosis, especially in wildlife species where this disease continues to persist in reservoir species such as the European Badger (Meles meles). However, gaining access to populations of badgers (protected under UK law) is problematic and not always possible. In this study, a new infection model has been developed in ferrets (Mustela furo), a species which is closely related to the badger. Groups of ferrets were infected using a Madison infection chamber and were examined postmortem for the presence of tuberculous lesions and to provide tissue samples for confirmation of Mycobacterium bovis by culture. An infectious dose was defined, that establishes infection within the lungs and associated lymph nodes with subsequent spread to the mesentery lymph nodes. This model, which emphasises respiratory tract infection, will be used to evaluate vaccines for the control of bovine tuberculosis in wildlife species.
RESUMO
To further understand the procognitive actions of GSK189254, a histamine H(3) receptor antagonist, we determined its influence on the modulation of hippocampal neural cell adhesion molecule (NCAM) polysialylation (PSA) state, a necessary neuroplastic mechanism for learning and memory consolidation. A 4-day treatment with GSK189254 significantly increased basal expression of dentate polysialylated cells in rats with the maximal effect being observed at 0.03-0.3 mg/kg. At the optimal dose (0.3 mg/kg), GSK189254 enhanced water maze learning and the associated transient increase in NCAM-polysialylated cells. The increase in dentate polysialylated cell frequency induced by GSK189254 was not attributable to enhanced neurogenesis, although it did induce a small, but significant, increase in the survival of these newborn cells. GSK189254 (0.3 mg/kg) was without effect on polysialylated cell frequency in the entorhinal and perirhinal cortex, but significantly increased the diffuse PSA staining observed in the anterior, ventromedial, and dorsomedial aspects of the hypothalamus. Consistent with its ability to enhance the learning-associated, post-training increases in NCAM PSA state, GSK189254 (0.3 mg/kg) reversed the amnesia induced by scopolamine given in the 6-h post-training period after training in an odor discrimination paradigm. Moreover, GSK189254 significantly improved the performance accuracy of a delayed match-to-position paradigm, a task dependent on the prefrontal cortex and degree of cortical arousal, the latter may be related to enhanced NCAM PSA-associated plasticity in the hypothalamus. The procognitive actions of H3 antagonism combined with increased NCAM PSA expression may exert a disease-modifying action in conditions harboring fundamental deficits in NCAM-mediated neuroplasticity, such as schizophrenia and Alzheimer's disease.
Assuntos
Benzazepinas/farmacologia , Aprendizagem por Discriminação/efeitos dos fármacos , Antagonistas dos Receptores Histamínicos H3/farmacologia , Memória/efeitos dos fármacos , Moléculas de Adesão de Célula Nervosa/metabolismo , Plasticidade Neuronal/efeitos dos fármacos , Niacinamida/análogos & derivados , Amnésia/induzido quimicamente , Amnésia/tratamento farmacológico , Amnésia/fisiopatologia , Animais , Benzazepinas/administração & dosagem , Encéfalo/efeitos dos fármacos , Encéfalo/fisiologia , Encéfalo/fisiopatologia , Sobrevivência Celular/efeitos dos fármacos , Aprendizagem por Discriminação/fisiologia , Relação Dose-Resposta a Droga , Antagonistas dos Receptores Histamínicos H3/administração & dosagem , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Aprendizagem em Labirinto/fisiologia , Memória/fisiologia , Neurogênese/efeitos dos fármacos , Plasticidade Neuronal/fisiologia , Neurônios/efeitos dos fármacos , Neurônios/fisiologia , Testes Neuropsicológicos , Niacinamida/administração & dosagem , Niacinamida/farmacologia , Percepção Olfatória/efeitos dos fármacos , Percepção Olfatória/fisiologia , Ratos , Ratos Wistar , Escopolamina , Fatores de TempoRESUMO
Inflammatory changes, characterized by an increase in pro-inflammatory cytokine production and up-regulation of the corresponding signaling pathways, have been described in the brains of aged rats and rats treated with the potent immune modulatory molecule lipopolysaccharide (LPS). These changes have been coupled with a deficit in long-term potentiation (LTP) in hippocampus. The evidence suggests that anti-inflammatory agents, which attenuate the LPS-induced and age-associated increase in hippocampal interleukin-1beta (IL-1beta) concentration, lead to restoration of LTP. Here we report that atorvastatin, a member of the family of agents that act as inhibitors of 3-hydroxy-3-methylglutaryl-CoA reductase, exerts powerful anti-inflammatory effects in brain and that these effects are mediated by IL-4 and independent of its cholesterol-lowering actions. Treatment of rats with atorvastatin increased IL-4 concentration in hippocampal tissue prepared from LPS-treated and aged rats and abrogated the age-related and LPS-induced increases in pro-inflammatory cytokines, interferon-gamma (IFNgamma) and IL-1beta, and the accompanying deficit in LTP. The effect of atorvastatin on the LPS-induced increases in IFNgamma and IL-1beta was absent in tissue prepared from IL-4(-/-) mice. The increase in IL-1beta in LPS-treated and aged rats is associated with increased microglial activation, assessed by analysis of major histocompatibility complex II expression, and the evidence suggests that IFNgamma may trigger this activation. We propose that the primary effect of atorvastatin is to increase IL-4, which antagonizes the effects of IFNgamma, the associated increase in microglial activation, and the subsequent cascade of events.
Assuntos
Ácidos Heptanoicos/farmacologia , Hipocampo/metabolismo , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Interleucina-4/biossíntese , Lipopolissacarídeos/toxicidade , Fármacos Neuroprotetores/farmacologia , Pirróis/farmacologia , Animais , Atorvastatina , Química Encefálica/efeitos dos fármacos , Colesterol/genética , Colesterol/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Hipocampo/patologia , Antígenos de Histocompatibilidade Classe II/biossíntese , Antígenos de Histocompatibilidade Classe II/genética , Hidroximetilglutaril-CoA Redutases/genética , Hidroximetilglutaril-CoA Redutases/metabolismo , Inflamação/induzido quimicamente , Inflamação/genética , Inflamação/metabolismo , Inflamação/patologia , Interferon gama/genética , Interferon gama/metabolismo , Interleucina-1beta/biossíntese , Interleucina-1beta/genética , Interleucina-4/genética , Masculino , Camundongos , Camundongos Knockout , Microglia/metabolismo , Microglia/patologia , Ratos , Ratos WistarRESUMO
Lipopolysaccharide (LPS) exerts a myriad of effects in rat hippocampus; it increases the concentration of the proinflammatory cytokine, interleukin-1beta (IL-1beta), and signalling via the IL-1 type I receptor (IL-1RI) resulting in phosphorylation of the stress-activated protein kinase, c-jun-N-terminal kinase (JNK) and impairment in long-term potentiation (LTP). This study was designed to establish whether activation of JNK is a pivotal event in mediating the effects of LPS in hippocampus and therefore LPS-treated rats were injected intracerebroventricularly with saline, the JNK inhibitor D-JNKI1, or with the anti-inflammatory cytokine IL-4, which antagonizes the effects of IL-1beta upstream of JNK activation. We report that IL-4 blocked the LPS-induced increase in IL-1RI expression and associated increases in phosphorylation of JNK and c-jun, whereas D-JNKI1 inhibited the LPS-induced phosphorylation of c-jun. Both IL-4 and D-JNKI1 inhibited the increase in caspase-3 staining which was associated with LPS treatment, and both abrogated the LPS-induced inhibition of LTP in perforant path-granule cell synapses. The data presented are consistent with the proposal that JNK activation, probably as a result of increased IL-1RI activation, is a critical step in mediating the detrimental effects of LPS in hippocampus.
Assuntos
Hipocampo/citologia , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Lipopolissacarídeos/farmacologia , Neurônios/efeitos dos fármacos , Animais , Animais Recém-Nascidos , Células Cultivadas , Interações Medicamentosas , Estimulação Elétrica/métodos , Ativação Enzimática , Inibidores Enzimáticos/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Imuno-Histoquímica/métodos , Interleucina-4/metabolismo , Interleucina-4/farmacologia , Proteínas Quinases JNK Ativadas por Mitógeno/antagonistas & inibidores , Potenciação de Longa Duração/efeitos dos fármacos , Potenciação de Longa Duração/efeitos da radiação , Masculino , Modelos Biológicos , Neurônios/metabolismo , Técnicas de Patch-Clamp/métodos , Fosforilação , Proteínas Proto-Oncogênicas c-jun/metabolismo , Ratos , Ratos Wistar , Receptores de Interleucina-1/metabolismoRESUMO
Lipopolysaccharide (LPS), a component of the cell wall of Gram-negative bacteria, has been shown to induce profound changes both peripherally and centrally. It has recently been reported that intraperitoneal injection of LPS inhibited long term potentiation (LTP) in perforant path-granule cell synapses and that this effect was coupled with an increase in the concentration of the proinflammatory cytokine, interleukin-1 beta (IL-1 beta). The LPS-induced effects were abrogated by inhibition of caspase-1, suggesting that IL-1 beta may mediate the effects of LPS. Here we report that the inhibition of LTP induced by LPS and IL-1 beta was coupled with stimulation of the stress-activated protein kinase p38 in hippocampus and entorhinal cortex and that this effect was abrogated by the p38 inhibitor SB203580, while the effect of LPS was markedly attenuated in C57BL/6 IL-1RI-/- mice. The data also indicate that activation of the transcription factor, nuclear factor kappa B (NF kappa B), may play a role, since the inhibitory effect of LPS and IL-1 beta on LTP was attenuated by the NF kappa B inhibitor, SN50; consistently, LPS and IL-1 beta led to activation of NF kappa B in entorhinal cortex. We suggest that one consequence of these LPS and IL-1 beta-induced changes is a compromise in glutamate release in dentate gyrus, which was coupled with the inhibition of LTP. The evidence is consistent with the idea that the LPS-induced impairment in LTP is mediated by IL-1 beta and is a consequence of activation of p38.