Neuroinflammation is associated with reduced SOCS2 and SOCS3 expression during intracranial HSV-1 infection.

Herpes simplex virus type 1 (HSV-1) is the main etiological agent of acute and sporadic encephalitis. Proteins of the suppressor of cytokine signaling (SOCS) family have shown to regulate the inflammation during HSV-1 infection in the brain. However, the effects of SOCS2 and SOCS3 in viral encephalitis remain unclear. The aim of the current study is to investigate the potential association between SOCS2, SOCS3, cytokines, and hippocampal damage, especially neuronal apoptosis, during acute intracranial HSV-1 infection in mice. Male C57BL/6 mice were infected by intracranial route with 102 plaque-forming units (PFU) inoculum of purified HSV-1. At three days post-infection (3 d.p.i.), mice were euthanized and their hippocampi were collected for histopathological analysis, immunohistochemical reaction against active caspase-3 and quantification of SOCS2, SOCS3 and cytokines (tumoral necrosis factor (TNF), interleukin (IL) 1ß, IL-6, IL-10; interferon (IFN) -α, IFN-ß, IFN-γ) mRNA expression. Infected mice exhibited neuronal loss and hemorrhagic focus in Cornu Ammonis (CA) region. The apoptotic index was higher in infected mice compared to controls. HSV-1 infection was associated with increased hippocampal expression of TNF, IL1-ß, IL-6 and IFNα/IFNß and decreased expression of IL-10, IFN-γ, SOCS2 and SOCS3. Our results suggest that down regulation of SOCS2 and SOCS3 contributes to a pro-inflammatory environment associated with hippocampal damage and neuronal apoptosis during acute HSV-1 infection in mice.

Frequency of overweight and obesity in children and adolescents with autism and attention deficit/hyperactivity disorder / Frequência de sobrepeso e obesidade em crianças e adolescentes com autismo e transtorno do déficit de atenção/hiperatividade

To assess the frequency of overweight and obesity in children and adolescents with autism spectrum disorder (ASD) and with attention deficit/hyperactivity disorder (ADHD) and their parents, in comparison with children and adolescents without developmental disorders. Methods: Anthropometric measures were obtained in 69 outpatients with ASD (8.4±4.2 years old), 23 with ADHD (8.5±2.4) and 19 controls without developmental disorders (8.6±2.9) between August and November 2014. Parents of patients with ASD and ADHD also had their anthropometric parameters taken. Overweight was defined as a percentile ≥85; obesity as a percentile ≥95; and underweight as a percentile ≤5. For adults, overweight was defined as a BMI between 25 and 30kg/m2 and obesity as a BMI higher than 30kg/m2. Results: Children and adolescents with ASD and ADHD had higher BMI percentile (p<0.01) and z-score (p<0.01) than controls, and increased frequency of overweight and obesity (p=0.04). Patients with ASD and ADHD did not differ between them in these variables, nor regarding abdominal circumference. Parents of children with ASD and ADHD did not differ between themselves. Conclusions: Children and adolescents with ASD and ADHD are at a higher risk of overweight and obesity than children without developmental problems in the community.

Avaliar a frequência de sobrepeso e obesidade em crianças e adolescentes com transtorno do espectro do autismo (TEA) e transtorno do déficit de atenção/hiperatividade (TDAH) e em seus pais, em comparação com crianças e adolescentes da comunidade sem transtornos do desenvolvimento. Métodos Medidas antropométricas foram coletadas de 69 pacientes com TEA (8,4±4,2 anos), 23 com TDAH (8,5±2,4) e 19 controles sem transtornos desenvolvimentais (8,6±2,9) entre agosto e novembro de 2014. Os pais dos pacientes com TEA e TDAH também foram avaliados em relação aos parâmetros antropométricos. Sobrepeso foi definido como percentil ≥85; obesidade como percentil ≥95; e baixo peso como percentil ≤5. Para os adultos, sobrepeso foi definido como IMC entre 25 e 30kg/m2 e obesidade, IMC acima de 30kg/m2. Resultados Crianças e adolescentes com TEA e TDAH exibiram maior percentil (p<0,01) e escore-z (p<0,01) do IMC em relação aos controles, bem como frequência mais elevada de sobrepeso e obesidade (p=0,04). Os pacientes com TEA e TDHA não diferiram entre si quanto a essas variáveis ou quanto à circunferência abdominal. Os pais das crianças com TEA e TDAH também não diferiram entre si. Conclusões Crianças e adolescentes com TEA e TDAH estão em maior risco de ter sobrepeso e obesidade em relação a crianças da comunidade sem problemas do desenvolvimento.

IL-1ß Is Involved with the Generation of Pain in Experimental Autoimmune Encephalomyelitis.

Pain is one of the main symptoms of multiple sclerosis, a demyelinating disease of the central nervous system that affects millions of people worldwide. The experimental autoimmune encephalomyelitis (EAE) is considered an experimental model of multiple sclerosis, and besides motor weakness, hypernociception is one of the clinical signs of animals with EAE. In this study, we investigated the influence of some cytokines in the generation of the hypernociceptive response in a mouse model of EAE using MOG35-55. We measured some cytokines in the dorsal root ganglia (DRG), an important anatomical structure involved in pain. We found increased levels of the cytokines TNF-α, IL-1ß, and Kc in DRGs of animals with EAE. We used the antibody IL-1ra to antagonize the effects of IL-1ß, and animals presented a decrease in the hypernociceptive response. Thus, our results suggest that hypernociception in this experimental model of EAE may be a consequence of the increase in some cytokines in DRGs, especially IL-1ß.

Propriedades psicométricas da Escala de Responsividade Social-2 para Transtornos do Espectro Autista / Psychometric properties of the Social Responsiveness Scale-2 (SRS-2) for Autism Spectrum Disorder

Objetivo O objetivo deste trabalho foi avaliar as propriedades psicométricas da versão em português da Escala de Responsividade Social-2 (ERS-2) para crianças e adolescentes com transtorno do espectro autista (TEA). Métodos A ERS-2 foi respondida pelos pais de 90 pacientes com TEA e 25 controles saudáveis. Análises quanto à validade discriminante, índices de confiabilidade e separação, de adequação e calibração dos itens pelo modelo Rasch foram realizadas. Resultados A ERS-2 demonstrou boa consistência interna (alfa de Cronbach = 0,952), um ponto de corte de 41, sensibilidade de 96,8%, especificidade de 100% e valor preditivo negativo de 99,9% para a identificação de TEA. As subescalas apresentaram, de forma geral, adequação ao modelo. No entanto, alguns itens se apresentaram pouco consistentes do ponto de vista estatístico (correlação item-total negativas e misfitting). O mapa de itens mostrou má cobertura da variável latente, especialmente no espectro mais leve do TEA. Conclusão Os resultados deste estudo mostraram que a versão em português da ERS-2 pode ser utilizada como ferramenta de triagem para o reconhecimento de TEA em crianças e adolescentes brasileiros. A escala pode ter versões futuras aprimoradas com a substituição dos itens com pior desempenho.

Objective The purpose of this research was to assess the psychometric properties of the Portuguese version of the Social Responsiveness Scale-2 (SRS-2) for children and adolescents with autism spectrum disorder (ASD). Methods Parents of 90 patients with ASD and 25 healthy controls responded to the SRS-2. Analyses about the discriminant validity, reliability and separation indexes, fitness and items calibration according to Rasch model were carried on. Results SRS-2 showed good internal consistency (Cronbach's alpha = 0.952), a cutoff score of 41, sensitivity of 96.8%, specificity of 100%, and negative predictive value of 99.9% for the diagnosis of ASD. The subscales generally fitted the model. However, some items presented suboptimal statistics performance (negative item-total correlation and misfitting). The item map showed that the latent variable was not entirely covered by the items, especially on the mildest end of the autistic spectrum. Conclusion The results of this study showed that the Portuguese version of SRS-2 can be used as a screening tool to improve the recognition of ASD in Brazilian children and adolescents. The scale might have improved versions in the future with the substitution of items with worse performance.

Phosphatidylinositol 3-Kinase γ is required for the development of experimental cerebral malaria.

Experimental cerebral malaria (ECM) is characterized by a strong immune response, with leukocyte recruitment, blood-brain barrier breakdown and hemorrhage in the central nervous system. Phosphatidylinositol 3-kinase γ (PI3Kγ) is central in signaling diverse cellular functions. Using PI3Kγ-deficient mice (PI3Kγ-/-) and a specific PI3Kγ inhibitor, we investigated the relevance of PI3Kγ for the outcome and the neuroinflammatory process triggered by Plasmodium berghei ANKA (PbA) infection. Infected PI3Kγ-/- mice had greater survival despite similar parasitemia levels in comparison with infected wild type mice. Histopathological analysis demonstrated reduced hemorrhage, leukocyte accumulation and vascular obstruction in the brain of infected PI3Kγ-/- mice. PI3Kγ deficiency also presented lower microglial activation (Iba-1+ reactive microglia) and T cell cytotoxicity (Granzyme B expression) in the brain. Additionally, on day 6 post-infection, CD3+CD8+ T cells were significantly reduced in the brain of infected PI3Kγ-/- mice when compared to infected wild type mice. Furthermore, expression of CD44 in CD8+ T cell population in the brain tissue and levels of phospho-IkB-α in the whole brain were also markedly lower in infected PI3Kγ-/- mice when compared with infected wild type mice. Finally, AS605240, a specific PI3Kγ inhibitor, significantly delayed lethality in infected wild type mice. In brief, our results indicate a pivotal role for PI3Kγ in the pathogenesis of ECM.

Role of the aryl hydrocarbon receptor in the immune response profile and development of pathology during Plasmodium berghei Anka infection.

Infection with Plasmodium falciparum may result in severe disease affecting various organs, including liver, spleen, and brain, resulting in high morbidity and mortality. Plasmodium berghei Anka infection of mice recapitulates many features of severe human malaria. The aryl hydrocarbon receptor (AhR) is an intracellular receptor activated by ligands important in the modulation of the inflammatory response. We found that AhR-knockout (KO) mice infected with P. berghei Anka displayed increased parasitemia, earlier mortality, enhanced leukocyte-endothelial cell interactions in the brain microvasculature, and increased inflammation in brain (interleukin-17 [IL-17] and IL-6) and liver (gamma interferon [IFN-γ] and tumor necrosis factor alpha [TNF-α]) compared to infected wild-type (WT) mice. Infected AhR-KO mice also displayed a reduction in cytokines required for host resistance, including TNF-α, IL-1ß, and IFN-γ, in the brain and spleen. Infection of AhR-KO mice resulted in an increase in T regulatory cells and transforming growth factor ß, IL-6, and IL-17 in the brain. AhR modulated the basal expression of SOCS3 in spleen and brain, and P. berghei Anka infection resulted in enhanced expression of SOCS3 in brain, which was absent in infected AhR-KO mice. These data suggest that AhR-mediated control of SOCS3 expression is probably involved in the phenotype seen in infected AhR-KO mice. This is, to our knowledge, the first demonstration of a role for AhR in the pathogenesis of malaria.

Protection of blood brain barrier integrity and modulation of inflammatory mediators during treatment of pneumococcal meningitis with daptomycin or ceftriaxone.

Pneumococcal meningitis is associated with neurologic sequelae, such as learning and memory impairment. Most recently, a nonbacteriolytic antibiotic has been investigated to minimise the inflammatory host response and prevent cognitive damage. In this study, we compared daptomycin (DPTO) or ceftriaxone (CFX) treatment on the inflammatory parameters and on the blood-brain barrier (BBB) integrity in experimental pneumococcal meningitis. In the first experiment, the animals received 10 µl of a Streptococcus pneumoniae suspension or artificial cerebrospinal fluid by intracerebroventricular (i.c.v.) and were treated with CFX or DPTO at 18 h post-infection. The animals were euthanised at 18, 20, 24, 36 and 40 h post-infection. In the hippocampus, brain-derived neurotrophic factor (BDNF), tumour necrosis factor alpha (TNF-α), interleukin-6 (IL-6) and IL-10 levels were not different between treatment groups; however, IL-4 and cytokine-induced neutrophil chemoattractant 1 (CINC-1) levels decreased in the CFX group. In the frontal cortex, TNF-α, IL- 4, IL-6, IL-10 and BDNF levels were not different between treatment groups. Only CINC-1 levels decreased at 40 h postinfection with CFX treatment. In the second experiment, the animals received DPTO or CFX for 7 days and were euthanised 10 days after pneumococcal meningitis induction. TNF-α, IL-6, IL-10, CINC-1 and BDNF levels were not different between treatment groups in the hippocampus; however, IL-4 levels decreased in CFX group. In the third experiment, the animals received 10 µl of an S. pneumoniae suspension or artificial CSF by i.c.v. and were treated with a single dose of CFX or DTPO antibiotic; assessment of the BBB breakdown showed that both antibiotics prevented the BBB disruption. Both treatments equally protected the BBB integrity, and there were no significant difference in cytokine production.

Changes in adipokine levels in autism spectrum disorders.

BACKGROUND AND OBJECTIVE: The etiopathogenesis of autism spectrum disorders (ASD) is largely unknown, but it seems to involve dysfunction in several biological systems. Among many possible biological pathways, the immune system has emerged as potentially involved. Recent studies have shown association between cytokines (molecules that mediate immune cell interaction) and ASD. Adipokines are cytokines secreted mainly by adipose tissue and may have systemic effects. The main objective of this study was to compare the plasma levels of three adipokines between patients with ASD and healthy controls. Another aim was to correlate the levels of these adipokines and the severity of autistic symptoms as measured by the Social Responsiveness Scale (SRS). METHODS: We collected plasma from 30 patients and 19 controls and measured the levels of adiponectin, leptin and resistin using a commercially available kit. We also used the SRS as a tool to assess the severity of autistic symptoms. RESULTS: We found decreased levels of resistin, increased levels of leptin and unaltered levels of adiponectin in plasma from ASD subjects in comparison with controls. There was also a negative correlation between the levels of adiponectin and the severity of symptoms as assessed by the SRS. CONCLUSION: There are significant changes in the plasma levels of adipokines from patients with ASDs. They suggest the occurrence of systemic changes in ASD and may be hallmarks of the disease.

Blockade of CXCR1/2 chemokine receptors protects against brain damage in ischemic stroke in mice

OBJECTIVE: Ischemic stroke may result from transient or permanent reductions of regional cerebral blood flow. Polymorphonuclear neutrophils have been described as the earliest inflammatory cells to arrive in ischemic tissue. CXCR1/2 receptors are involved in the recruitment of these cells. However, the contribution of these chemokine receptors during transient brain ischemia in mice remains poorly understood. In this work, we investigated the effects of reparixin, an allosteric antagonist of CXCR1/2 receptors, in a model of middle cerebral artery occlusion and reperfusion in mice. METHODS: C57BL/6J male mice treated with reparixin or vehicle were subjected to a middle cerebral artery occlusion procedure 1 h after the treatment. Ninety minutes after ischemia induction, the monofilament that prevented blood flow was removed. Twenty-four hours after the reperfusion procedure, behavioral changes, including motor signs, were analyzed with the SmithKline/Harwell/lmperial College/Royal Hospital/Phenotype Assessment (SHIRPA) battery. The animals were sacrificed, and brain tissue was removed for histological and biochemical analyses. Histological sections were stained with hematoxylin and eosin, neutrophil infiltration was estimated by myeloperoxidase activity and the inflammatory cytokine IL-iβ was measured by ELISA. RESULTS: Pre-treatment with reparixin reduced the motor deficits observed in this model of ischemia and reperfusion. Myeloperoxidase activity and IL-iβ were reduced in the reparixin-treated group. Histological analysis revealed that ischemic injury was also attenuated by reparixin pre-treatment. CONCLUSIONS: Our results suggest that the blockade of the CXCR1/2 receptors by reparixin promotes neuroprotective effects by reducing the levels of polymorphonuclear infiltration in the brain and the tissue damage associated with middle cerebral artery occlusion and reperfusion.

Dengue-3 encephalitis promotes anxiety-like behavior in mice.

Dengue virus is a human pathogen that may cause meningoencephalitis and other neurological syndromes. The current study investigated anxiety-like behavior and expression of proinflammatory cytokines and pro-apoptotic caspase-3 in the hippocampus of C57BL/6 mice infected with non-adapted Dengue virus 3 genotype I (DENV-3) inoculated intracranially with 4×10(3) (plaque-forming unit) PFU. Anxiety-like behavior was assessed in control and DENV-3 infected mice using the elevated plus maze. The open field test was performed to evaluate locomotor activity. Histopathological changes in CA regions of the hippocampus were assessed by haematoxylin and eosin staining. Immunoreactive and protein levels of cleaved caspase-3 were also analyzed in the hippocampus. The mRNA expression of IL-6 and TNF-α in the hippocampus were estimated by quantitative real time (polymerase chain reaction) PCR. All procedures were conducted on day 5 post-infection. We found that DENV-3 infected mice presented higher levels of anxiety in comparison with controls (p≤0.05). No difference in motor activity was found between groups (p=0.77). The infection was followed by a significant increase of TNF-α and IL-6 mRNA expression in the hippocampus (p≤0.05). Histological analysis demonstrated meningoencephalitis with formation of perivascular cuffs, infiltration of immune cells and loss of neurons at CA regions of hippocampus. Numerous caspase-3 positive neurons were visualized at CA areas in DENV-3 infected mice. Marked increase of cleaved caspase-3 levels were observed after infection. This study described anxiety-like behavior, hippocampal inflammation and neuronal apoptosis associated with DENV-3 infection in the central nervous system.

Behavioral investigation of mice with experimental autoimmune encephalomyelitis / Investigação comportamental de camundongos com encefalomielite autoimune experimental

Multiple sclerosis is a neuroinflammatory disease that results in serious neurological disability. Besides physical impairment, behavioral symptoms are also common in patients with multiple sclerosis. Experimental autoimmune encephalomyelitis (EAE) is considered to be a model of multiple sclerosis and mimics the main features of the disease, such as demyelination and motor impairment. In this work, we aimed to study behavioral parameters in animals with EAE using the MOG35-55 model in C57BL/6 mice. We analyzed memory and anxiety in animals using the elevated plus maze, the step down inhibitory avoidance task and the memory recognition test. No differences in any tests were found when comparing controls and animals induced with EAE. Therefore, we conclude that behavioral changes in animals with EAE induced with MOG35-55 are probably subtle or absent.

Esclerose múltipla é uma doença neuroinflamatória que resulta em séria incapacidade neurológica. Além do comprometimento físico, sintomas comportamentais também são comuns em pacientes com esclerose múltipla. A encefalomielite autoimune experimental (EAE) é considerada um modelo de esclerose múltipla e mimetiza as principais caracte-rísticas da doença, como a desmielinização e a fraqueza motora. Neste trabalho, objetivamos estudar parâmetros comportamentais em animais com EAE usando o modelo de MOG35-55 em camundongos C57BL/6. Analisamos memória e ansiedade em animais utilizando o labirinto em cruz elevado, o teste da esquiva inibitória e o teste de memória de reconhecimento. Nenhuma diferença em quaisquer dos testes foi encontrada comparando animais controles e animais induzidos com EAE. Assim, concluímos que alterações comportamentais em animais com EAE induzidos com MOG35-55 são provavelmente sutis ou ausentes.

Role of IL-4 in an experimental model of encephalitis induced by intracranial inoculation of herpes simplex virus-1 (HSV-1).

Herpes simplex virus-1 (HSV-1) is a pathogen that may cause severe encephalitis in humans. In this study, we aimed to investigate the role of interleukin-4 (IL-4) in a model of HSV-1 brain infection. IL-4 knockout (IL-4-/-) and wild type (WT) C57BL/6 mice were inoculated with 10(4) plaque-forming units of HSV-1 by the intracranial route. Histopathologic analysis revealed a distinct profile of infiltrating cells at 3 days post-infection (dpi). Infected WT mice presented mononuclear inflammatory cells while IL-4-/- mice developed meningoencephalitis with predominance of neutrophils. IL-4-/- mice had diminished leukocyte adhesion at 3 dpi when compared to infected WT animals in intravital microscopy study. Conversely no differences were found in cerebral levels of CXCL1, CXCL9, CCL3, CCL5 and TNF-α between WT and IL-4-/- infected mice. IL-4 may play a role in the recruitment of cells into central nervous system in this acute model of severe encephalitis caused by HSV-1.

Role of IL-4 in an experimental model of encephalitis induced by intracranial inoculation of herpes simplex virus-1 (HSV-1) / Papel da IL-4 em modelo experimental de encefalite induzida pela inoculação intracraniana do herpes simplex vírus-1 (HSV-1)

Herpes simplex virus-1 (HSV-1) is a pathogen that may cause severe encephalitis in humans. In this study, we aimed to investigate the role of interleukin-4 (IL-4) in a model of HSV-1 brain infection. IL-4 knockout (IL-4-/-) and wild type (WT) C57BL/6 mice were inoculated with 10(4) plaque-forming units of HSV-1 by the intracranial route. Histopathologic analysis revealed a distinct profile of infiltrating cells at 3 days post-infection (dpi). Infected WT mice presented mononuclear inflammatory cells while IL-4-/- mice developed meningoencephalitis with predominance of neutrophils. IL-4-/- mice had diminished leukocyte adhesion at 3 dpi when compared to infected WT animals in intravital microscopy study. Conversely no differences were found in cerebral levels of CXCL1, CXCL9, CCL3, CCL5 and TNF-α between WT and IL-4-/- infected mice. IL-4 may play a role in the recruitment of cells into central nervous system in this acute model of severe encephalitis caused by HSV-1.

O vírus herpes simplex-1 (HSV-1) é um patógeno que pode causar encefalite grave em humanos. Neste estudo, buscamos investigar o papel da interleucina-4 (IL-4) no modelo de infecção intracerebral por HSV-1. Camundongos C57BL/6 selvagens (WT) e deficientes no gene IL-4 (IL-4-/-) foram inoculados com 10(4) unidades formadoras de placas de HSV-1 por via intracraniana. A análise histopatológica revelou um padrão distinto de infiltrado leucocitário. Camundongos WT infectados apresentaram infiltrado de células mononucleares, enquanto camundongos IL-4-/- desenvolveram meningoencefalite com predomínio de neutrófilos 3 dias pós-infecção (dpi). Animais IL-4-/- tiveram menor adesão de leucócitos 3 dpi quando comparados aos animais WT infectados à microscopia intravital. Em contrapartida, não foram encontradas diferenças nos níveis cerebrais de CXCL1, CXCL9, CCL3, CCL5 e TNF-α entre camundongos WT e IL-4-/- infectados. Esses resultados sugerem que IL-4 pode desempenhar um papel no recrutamento de células no sistema nervoso central neste modelo agudo de encefalite grave causada pelo HSV-1.

A thioacetamide-induced hepatic encephalopathy model in C57BL/6 mice: a behavioral and neurochemical study / Modelo de encefalopatia hepática induzida por tioacetamida em camundongos C57BL/6: estudo comportamental e neuroquímico

OBJECTIVE: Hepatic encephalopathy (HE) is a neuropsychiatric syndrome resulting from liver failure. In the present study, we aimed to standardize an animal model of HE induced by thioacetamide (TAA) in C57BL/6 mice evaluating behavioral symptoms in association with liver damage and alterations in neurotransmitter release. METHOD: HE was induced by an intraperitoneal single dose of TAA (200 mg/kg, 600 mg/kg or 1,200 mg/kg). Behavioral symptoms were evaluated using the SHIRPA battery. Liver damage was confirmed by histopathological analysis. The glutamate release was measured using fluorimetric assay. RESULTS: The neuropsychiatric state, motor behavior and reflex and sensory functions were significantly altered in the group receiving 600 mg/kg of TAA. Biochemical analysis revealed an increase in the glutamate release in the cerebral cortex of HE mice. CONCLUSION: HE induced by 600mg/kg TAA injection in C57BL/6 mice seems to be a suitable model to investigate the pathogenesis and clinical disorders of HE.

OBJETIVO: A encefalopatia hepática (EH) é uma síndrome neuropsiquiátrica resultante da falência hepática. O objetivo do presente estudo foi estabelecer um modelo de EH induzida por tioacetamida (TAA) em camundongos C57BL/6 avaliando transtornos comportamentais, falência hepática e alterações na liberação de neurotransmissores. MÉTODO: A EH foi induzida por meio de uma única dose intraperitoneal de TAA (200 mg/kg, 600 mg/kg, 1.200 mg/kg). As alterações comportamentais foram avaliadas utilizando a bateria SHIRPA. A falência hepática foi confirmada através de análises histopatológicas e a liberação de glutamato medida, por ensaio fluorimétrico. RESULTADOS: Foram encontradas alterações significativas no estado neuropsiquiátrico, comportamento motor e função reflexa e sensorial no grupo que recebeu 600 mg/kg de TAA. Análises bioquímicas revelaram aumento na liberação de glutamato no córtex cerebral dos camundongos com EH. CONCLUSÃO: A EH induzida por 600 mg/kg de TAA em camundongos C57BL/6 parece ser um modelo apropriado para a investigação da patogênese e dos transtornos clínicos da EH.

TNFR1 plays a critical role in the control of severe HSV-1 encephalitis.

Herpes simplex virus-1 (HSV-1) is a pathogen for humans that may cause severe encephalitis. Tumor necrosis factor alpha (TNF-alpha) plays a role in several viral diseases of the central nervous system (CNS). The classic proinflammatory activities of TNF-alpha are mediated mainly through activation of the receptor 1 for TNF-alpha (TNFR1). However, when HSV-1 is inoculated in the periphery, TNF-alpha seems to protect C57Bl/6 mice against encephalitis by a mechanism independent of TNFR1. This study aims to investigate the role of TNFR1 in HSV-1 encephalitis induced by the inoculation of the virus into the brain. Wild-type C57BL/6 (WT) and TNFR1(-/-) were inoculated with 10(2) plaque-forming units of HSV-1 by the intracranial route. Infection with HSV-1 was lethal in TNFR1(-/-) mice in early times after infection. TNFR1(-/-) mice had reduced expression of the chemokines CCL3 and CCL5, and decreased leukocyte adhesion in the brain vasculature compared to WT mice 4 days post-infection (dpi). At this time point TNFR1(-/-) infected mice also had higher HSV-1 viral replication and more injuries in the brain, especially in the hippocampus. In conclusion, TNFR1 seems to play a relevant role in the control of viral replication in the CNS when HSV-1 is inoculated by intracranial route.

Absence of PI3Kgamma leads to increased leukocyte apoptosis and diminished severity of experimental autoimmune encephalomyelitis.

Phosphatidylinositol-3-kinase gamma (PI3Kgamma) plays an important role in the motility of leukocytes in several models of inflammation. In this work, the role of PI3Kgamma in experimental autoimmune encephalomyelitis (EAE) was investigated. EAE was induced in wild-type and PI3Kgamma deficient mice (PI3Kgamma(-)(/)(-)). WT animals had a peak of clinical symptoms around day 14 post-induction (p.i.). PI3Kgamma(-)(/)(-) animals developed milder EAE signs and peak of disease was noticed only on day 21 p.i. Better clinical outcome correlated with the absence of perivascular cuffs on day 14 p.i. and with decreased levels of CCL2 and CCL5 in brain of PI3Kgamma(-)(/)(-) mice. There was increased leukocyte rolling and adhesion in pial vessels, as assessed by intravital microscopy, at day 14 after EAE induction in WT mice. The latter parameters were unaltered in PI3Kgamma(-)(/)(-) mice subjected to EAE. Moreover, the PI3Kgamma inhibitor AS-605240 given just before the intravital microscopy failed to affect leukocyte rolling or adhesion. Finally, there was a significant increase in the number of apoptotic cells in the CNS of EAE-induced PI3Kgamma(-/-) mice. Our results suggest that PI3Kgamma is involved in EAE and plays a more important role in mediating leukocyte survival than leukocyte adhesion in this experimental model of multiple sclerosis.

Inflammatory changes in the central nervous system are associated with behavioral impairment in Plasmodium berghei (strain ANKA)-infected mice.

Experimental cerebral malaria is a neuroinflammatory condition that results from the host immune response to the parasite. Using intravital microscopy, we investigated leukocyte recruitment in the brain microcirculation and the temporal relationship of this process to the behavioral changes observed in Plasmodium berghei (strain ANKA)-infected C57Bl/6 mice. We found that leukocyte recruitment was increased from day 5 post-infection (p.i.) onwards. Histopathological changes and increased levels of inflammatory cytokines in the brain were also observed. Behavioral performance evaluated by the SHIRPA protocol showed functional impairment from day 6 p.i. onwards. Thus, early leukocyte migration into the brain and associated inflammatory changes may be involved in neurological impairment in parasite-infected C57Bl/6 mice.

Mechanical hypernociception in experimental autoimmune encephalomyelitis / Hipernocicepção mecânica em encefalomielite autoimune experimental

BACKGROUND: Pain is an important clinical manifestation in multiple sclerosis (MS) patients, though it has been neglected in clinical and experimental researches. OBJECTIVE: To investigate the nociceptive response in MOG35-55 experimental autoimmune encephalomyelitis (EAE)-induced mice. METHOD: EAE was induced in 8 to 10 week old C57BL/6 female mice with an emulsion of MOG35-55, Complete Freund Adjuvant, Mycobacterium tuberculosis H37 RA and pertussis toxin. Nociception was evaluated by the von Frey filaments method. A clinical scale ranging from 0 to 15 was used to assess motor impairment. RESULTS: Clinical evidence of disease started at day 10 and peaked at day 14 after immunization. Thereafter, there was no worsening of symptoms until day 26. The EAE-induced mice presented reduced pressure threshold at days 7th and 10th after immunization and before the onset of clinical motor signs. CONCLUSION : The hypernociception found validates MOG35-55 EAE as a model for the study of pain in multiple sclerosis.

INTRODUÇÃO: Dor é uma manifestação importante em pacientes com esclerose múltipla (EM), mas que tem sido negligenciada na pesquisas clínica e experimental. OBJETIVO: Investigar a resposta nociceptiva de camundongos com encefalomielite autoimune experimental (EAE) induzida por MOG35-55. MÉTODO: A EAE foi induzida em camundongos C57BL/6 fêmeas de 8-10 semanas com emulsão contendo MOG35-55, Adjuvante Completo de Freund, Mycobacterium tuberculosis cepa H37 RA e toxina pertussis. A nocicepção foi medida pelo método de filamentos de von Frey. Uma escala clínica variando de 0 a 15 foi utilizada para avaliar a debilidade motora dos animais. RESULTADOS: Os sinais clínicos da doença iniciaram-se no dia 10 e a gravidade máxima foi alcançada no dia 14 após a imunização. Não houve piora dos sintomas até o dia 26. Os camundongos induzidos com EAE apresentaram diminuição do limiar de pressão nos dias 7 e 10 após a imunização e antes do início dos sinais motores. CONCLUSÃO: A hipernocicepção verificada valida a EAE induzida por MOG35-55 como um modelo para estudos de dor em esclerose múltipla.

Increased serum levels of CXCL8 chemokine in acute toxoplasmic retinochoroiditis.

PURPOSE: Chemokines have been implicated in the control of leucocyte infiltration in uveitis and in modulating angiogenesis in several ocular conditions. Toxoplasmic retinochoroiditis is a common cause of posterior uveitis. This study aimed to evaluate the serum concentrations of CC and CXC chemokines in patients with acute toxoplasmic retinochoroiditis. METHODS: The levels of five chemokines (CCL2, CCL11, CXCL9, CXCL8 and CXCL10) were evaluated in the serum of patients with active toxoplasmic retinochoroiditis (n = 55) and control subjects (n = 40). In a subset of patients (n = 18), a second measure of serum levels of chemokines was performed after the completion of oral treatment with pyrimethamine (25 mg/day), sulphadiazine (1 g, four times per day), folinic acid (7.5 mg/day) and prednisone (initial dose: 1 mg/kg/day) for approximately 30 days. RESULTS: Patients with toxoplasmic retinochoroiditis, notably those presenting with vasculitis, had increased serum levels of CXCL8 (mean +/- standard error of the mean [SEM] 35.1 +/- 6.5 pg/ml) compared with control subjects (mean +/- SEM 16.0 +/- 2.3 pg/ml; p = 0.01). There were no differences between patients and controls in serum levels of the other chemokines measured. The size of ocular lesions correlated significantly with serum levels of CXCL8 and CXCL9. After treatment, there was a significant reduction in serum levels of CXCL8. Severity of vitreous opacities did not correlate with serum levels of these chemokines. CONCLUSIONS: These data suggest a role for CXCL8 in the inflammatory process of acute toxoplasmic retinochoroiditis. Furthermore, CXCL8 may be a useful marker for patient follow-up.