Cornuside ameliorated experimental autoimmune encephalomyelitis by limiting the recruitment of CD4+ T lymphocytes in the spinal cord

We conducted this study to determine whether cornuside could improve the neurological deficit symptoms of experimental autoimmune encephalomyelitis (EAE) rats, as well as determine the potential involvement of CD4+ T lymphocytes, vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1), and tumor necrosis factor-α (TNF-α). Altogether, 32 Lewis rats were randomly divided into control, EAE, EAE/prednisolone, and EAE/cornuside, wherein their neurological function was assessed every day. CD4+ T lymphocyte recruitment into the spinal cord (SC) was evaluated using immunohistochemistry. The VCAM-1, ICAM-1 and TNF-α mRNA expressions in the SC were determined by real-time quantitative PCR, and the VCAM-1 and ICAM-1 proteins were determined by western blotting. Compared to the control group, the EAE group rats with neurological deficits had enhanced CD4+ T lymphocyte infiltration and higher expression levels of VCAM-1, ICAM-1, and TNF-α in the SC. Meanwhile, compared with the EAE group, the EAE/cornuside and EAE/prednisolone groups had lower neurological scores, less CD4+ T lymphocyte infiltrations, and lower expression levels of VCAM-1, ICAM-1, and TNF-α in the SC. Thus, cornuside ameliorated EAE, which could be owed to the inhibition of CD4+ T lymphocyte recruitment and VCAM-1, ICAM-1, and TNF-α expressions in the SC

Efeitos da exposição à fumaça do cigarro e suas implicações na neuroinflamação / Effects of exposure to cigarette smoke and its implications on neuroinflammation

O Sistema Nervoso Central (SNC) humano é formado por cerca de 86,1 bilhões de neurônios entre o encéfalo e a medula espinhal. O desenvolvimento pré-natal humano (tempo da concepção ao nascimento) possui cerca de 38 semanas, e é dividido na fase embrionária que corresponde ao período das 8 semanas iniciais da gestação, seguido pela fase fetal. A fase embrionária é o período mais vulnerável à ocorrência de anormalidades congênitas. Por ser um órgão com grande período de desenvolvimento, o SNC está sujeito às alterações genéticas, epigenéticas e ambientais. Durante a fase de implantação do embrião, o DNA é mais vulnerável às influências externas, como à fumaça do cigarro, aumentando o risco de retardo do desenvolvimento fetal, o risco de morte súbita pós-natal e de anormalidades do sistema imune. Neste contexto, o objetivo deste trabalho é avaliar os efeitos da exposição à fumaça do cigarro sobre o processo de neuroinflamação da prole de camundongos C57BL/6 expostos à fumaça do cigarro durante a gestação e desafiados ou não com LPS. Para tanto, camundongos C57BL/6 fêmeas prenhes foram expostas à fumaça do cigarro desde o plug vaginal até o nascimento da prole. No 3º dia de vida, os filhotes foram separados para três linhas de trabalho: 1) in vivo: os animais foram desafiados com LPS pelo período de 4h, seguidos de eutanasia e análises de PCR Array do SNC. 2) in vitro: os encéfalos dissecados foram utilizados para a preparação de cultura mista de glia e da cultura enriquecida com neurônio. Após a maturação celular, as células foram estimuladas com LPS 100 ng/mL e, após 24h, foram realizados ensaios de CBA, citometria de fluxo, PCR, dosagem de NO, avaliação de morte celular e metilação global. 3) Encefalomielite Autoimune Experimental (EAE): após o desmame, os animais foram mantidos em suas caixas moradia por 8 semanas sem nenhum estímulo externo, e então foram imunizados com MOG35-55 para o desenvolvimento da EAE. Nos experimentos in vivo observamos o aumento da transcrição de genes relacionados ao processo inflamatório, como interleucinas e quimiocinas. Em relação aos experimentos in vitro observamos maior crescimento de células astrocitárias (astrogliose), e células da microglia com aumento de moléculas co-estimuladoras (CD80 e CD86) bem como da transcrição e concentração de citocinas pró-inflamatórias e produção de NO. Em cultura enriquecida de neurônio, foi observado aumento na porcentagem de células em apoptose no grupo exposto à fumaça do cigarro desafiados ou não com LPS. O bloqueio da atividade da microglia pela minociclina reverteu a apoptose e diminuiu a produção de NO minimizando a morte celular. Em relação aos experimentos de EAE, os animais expostos à fumaça do cigarro no período gestacional, quando imunizados na vida adulta apresentam aumento no grau da doença bem como maior persistência da mesma quando observado escore clínico, além de acompanhados de um grau maior de infiltrado celular e desmielinização. Desta forma podemos concluir que a exposição à fumaça do cigarro durante o período gestacional leva a uma programação fetal com aumento da resposta neuroinflamatória frente a um estimulo sistêmico, trazendo consequências na vida adulta

The human central nervous system (CNS) is made up of about 86.1 billion neurons between the brain and the spinal cord. The human prenatal development (time from conception to birth) is about 38 weeks, and is divided into the embryonic phase that corresponds to the period of the initial 8 weeks of gestation, followed by the fetal phase. The embryonic stage is the period most vulnerable to the occurrence of congenital abnormalities. Because it is an organ with a long period of development, the CNS is subject to genetic, epigenetic and environmental changes. During the embryo implantation phase, DNA is more vulnerable to external influences such as cigarette smoke, increasing the risk of delay on fetal development, risk of sudden postnatal death, and abnormalities of the immune system. In this context, the aim of this work is to evaluate the effects of exposure to cigarette smoke on the neuroinflammation process of offspring of C57BL/6 mice exposed to cigarette smoke during gestation and challenged or not with LPS. For this, pregnant female C57BL/6 mice were exposed to cigarette smoke from vaginal plug to offspring birth. On the 3rd day of life the offspring were separated into three lines of work: 1) in vivo: the animals were challenged with 1mg/Kg LPS and after 4h they followed to euthanasia; PCR analysis of the CNS was made in this period. 2) in vitro: dissected encephalons were used for the preparation of mixed culture of glia and the culture enriched with neuron. After cell maturation, the cells were stimulated with 100 ng/mL LPS and, after 24 hours, CBA, flow cytometry, PCR, NO assay, cell death and global methylation assays were performed. 3) Experimental Autoimmune Encephalomyelitis (EAE): After weaning, the animals were kept in their housing for 8 weeks without any external stimulus, and then were immunized with MOG35-55 for the development of EAE. In the in vivo experiments we observed increased transcription of genes related to the inflammatory process, such as interleukins and chemokines. In vitro experiments showed higher growth of astrocytes (astrogliosis) and microglia cells with increased stimulatory molecules (CD80 and CD86) as well as the transcription and concentration of proinflammatory cytokines and NO production. In the enriched neuron culture, an increase in the percentage of cells in apoptosis was observed in the group exposed to cigarette smoke challenged or not with LPS. Blocking microglial activity by minocycline reversed apoptosis and decreased NO production by minimizing cell death. The EAE experiments shows that the animals exposed to cigarette smoke in the gestational period, when immunized in adulthood, present an increase in the degree of the disease as well as a greater persistence of the disease; The higher as the clinical score higher is the degree of cellular infiltration and demyelination. In this way we can conclude that the exposure to cigarette smoke during the gestational period leads to a fetal programming with increased neuroinflammatory response to a systemic stimulus and that this is able to last until the adult stage

BJ-1108, a 6-Amino-2,4,5-trimethylpyridin-3-ol analogue, regulates differentiation of Th1 and Th17 cells to ameliorate experimental autoimmune encephalomyelitis

BACKGROUND: CD4+ T cells play an important role in the initiation of an immune response by providing help to other cells. Among the helper T subsets, interferon-γ (IFN-γ)-secreting T helper 1 (Th1) and IL-17-secreting T helper 17 (Th17) cells are indispensable for clearance of intracellular as well as extracellular pathogens. However, Th1 and Th17 cells are also associated with pathogenesis and contribute to the progression of multiple inflammatory conditions and autoimmune diseases. RESULTS: In the current study, we found that BJ-1108, a 6-aminopyridin-3-ol analogue, significantly inhibited Th1 and Th17 differentiation in vitro in a concentration-dependent manner, with no effect on proliferation or apoptosis of activated T cells. Moreover, BJ-1108 inhibited differentiation of Th1 and Th17 cells in ovalbumin (OVA)-specific OT II mice. A complete Freund's adjuvant (CFA)/OVA-induced inflammatory model revealed that BJ-1108 can reduce generation of proinflammatory Th1 and Th17 cells. Furthermore, in vivo studies showed that BJ-1108 delayed onset of disease and suppressed experimental autoimmune encephalomyelitis (EAE) disease progression by inhibiting differentiation of Th1 and Th17 cells. CONCLUSIONS: BJ-1108 treatment ameliorates inflammation and EAE by inhibiting Th1 and Th17 cells differentiation. Our findings suggest that BJ-1108 is a promising novel therapeutic agent for the treatment of inflammation and autoimmune disease.

Neumomediastino y necrosis cutánea en asociación a dermatomiositis: presentación de un caso clínico y revisión de la literatura / Pneumomediastinum and cutaneous necrosis in dermatomyositis: Report of one case

We report a 37 years old male with a dermatomyositis treated with oral cyclophosphamide. He was admitted to the hospital due to a zone of skin necrosis with purulent exudate, located in the second left toe. A complete blood count showed a leukocyte count of 2,600 cells/mm³. A Chest CAT scan showed a pneumomediastinum with emphysema of adjacent soft tissue. Cyclophosphamide was discontinued and leukocyte count improved. The affected toe was amputated and a chest CAT scan showed a partial resolution of the pneumomediastinum. We discuss and review the pathogenesis, clinical presentation and management of pneumomediastinum and cutaneous necrosis in association with dermatomyositis.

Efeito da talidomida sobre o processo inflamatório e desmielinização na encefalomielite auto-imune experimental: estudo histopatológico e expressão de TNF-α e iNOS / Effect of thalidomide on the inflammatory process and demyelination in experimental autoimmune encephalomyelitis: histopathologic study and expression of TNF-α e iN

A encefalomielite autoimune experimental (EAE) é uma doença inflamatória e desmielinizante do sistema nervoso central (SNC) caracterizada por incapacidades temporárias ou permanentes. A patogênese envolve a reação auto-imune associada com a produção de citocinas pró inflamatórias, tais como o fator de necrose tumoral alfa (TNF-α). Esta citocina está associada com o aumento de radicais livres de oxigênio, como o óxido nítrico, liberados pelas células imunes ativadas. Além de aumentar a inflamação, tanto o fator de necrose tumoral, como o óxido nítrico causam lesão tecidual direta. Este estudo avaliou o efeito da talidomida na progressão clínica da doença, desenvolvimento da reação inflamatória e desmielinização. A expressão tecidual "in situ" do TNF-α e iNOS, uma enzima associada com a produção de óxido nítrico, foi investigada em amostras do SNC obtidos durante o desenvolvimento do modelo de EAE em ratos Lewis. Métodos: Ratos Lewis(n = 30) foram divididos em grupo de controle saudável (I), grupo experimental de encefalomielite autoimune (II) e o grupo tratado com talidomida (III). Os ratos foram monitorizados durante 15 dias para determinação da condição clínica, após este período, os animais foram eutanasiados e as amostras do sistema nervoso central foram obtidas para a realização de estudo histopatológico e imuno-histoquímico Resultados: Todos os animais do grupo II tiveram sintomas relacionados a EAE, enquanto apenas um do grupo tratado talidomida apresentaram alterações clínicas. O estudo histopatológico revelou que as amostras de SNC do grupo II apresentaram áreas de intenso infiltrado inflamatório mononuclear difuso e presença de áreas de desmielinização. No entanto, os animais tratados com talidomida apresentaram ocasionalmente um leve infiltrado inflamatório e bainhas de mielina bem organizadas. Além disso, a expressão de TNF-α e iNOS foram significativamente maiores no grupo II, quando comparado com o grupo tratado com a talidomida. Conclusões: Os resultados considerados em conjunto sustentam a hipótese de que a talidomida inibe a intensidade do processo inflamatório e desmielinização, assim como reduz a produção de mediadores inflamatórios modulando o desenvolvimento da encefalomielite auto-imune experimental em ratos Lewis.

Experimental autoimmune encephalomyelitis is a inflammatory and demyelinating disease of central nervous system (CNS) characterized by permanents or temporary disabilities. Its pathogenesis involves autoimmune reaction associated with the production of pro inflammatory cytokines such as tumor necrosis factor alpha (TNF-α). This cytokine is associated with increase of reactive oxygen free radicals, such as nitric oxide, released by activated immune cells. Besides enhancing inflammation, both tumor necrosis factor as nitric oxide cause pathologically direct destruction of proteins and enzyme oxidation. This study focuses on clinical disease progression, development of the inflammatory reaction and evaluation axonal myelination . The " in situ" tissue expression of the TNF-α and inducible nitric oxide synthase iNOS ,an enzyme associated with the production of nitric oxide , were also investigated in CNS samples obtained during the development of experimental autoimmune encephalomyelitis model in Lewis rats. Methods: Lewis rats were used to perform the classical model of EAE. The rats ( n=30) were divided into the healthy control group (I), experimental autoimmune encephalomyelitis group (II) and thalidomide treated group (III). The rats were monitored for 15 days for determination of clinical score , after this period , the animals were euthanized and samples were obtained from the central nervous system in which histopatological study and immunohistochemistry for SNC in situ detection of TNF-α and inducible nitric oxide synthase (iNOS) were performed. Results: All animals of group II had symptoms related to experimental encephalomyelitis , while only one of the thalidomide treated group showed clinical changes. The histopatological study revealead that SNC samples of group II presented areas of intense focal and diffuse mononuclear inflammation and the myelin sheaths were scarce and poorly stained. However, thalidomide treated rats presented occasionally a mild perivascular inflammatory infiltrate and myelin sheaths were organized and well evidenced. In addition, the expression of TNF-α and iNOS were significantly higher in the group II when compared with thalidomide treated group. Conclusions: The results taken together support the hypothesis that thalidomide inhibits the intensity of the inflammation and demyelination process and as well as reduces the production of inflammatory mediators influencing the development of experimental autoimmune encephalomyelitis in Lewis rats

Avaliação do efeito da crotoxina em animais portadores de encefalomielite autoimune experimental, um modelo de animais de esclerose múltipla / Evaluation of crotoxin effect in the experimental autoimune encephalomyelitis, an animal model of multiple sclerosis

A esclerose múltipla é uma doença inflamatória crônica, de origem autoimune, que acarreta diversas alterações motoras, cognitivas e sensitivas. Dentre as alterações sensitivas, a dor é um dos graves problemas que afetam pessoas portadoras desta doença, interferindo com diversos aspectos da vida do paciente. É importante ressaltar que a esclerose múltipla não tem cura, sendo que a terapêutica se concentra nas ações que retardam a progressão da doença e promovem o alívio dos sintomas, melhorando a qualidade da vida do paciente...

Multiple sclerosis is a Central Nervous System Inflamatory demyelinating disease that has as primary symptomps losses of sensory, cognitive and motor functions. Among the sensory alternations, pain is one of the major concern, afecting various aspects of the patients lives...

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.

Decreased production of TNF-alpha by lymph node cells indicates experimental autoimmune encephalomyelitis remission in Lewis rats

Experimental autoimmune encephalomyelitis (EAE) is mediated by CD4+ Th1 cells that mainly secrete IFN-γ and TNF-α, important cytokines in the pathophysiology of the disease. Spontaneous remission is, in part, attributed to the down regulation of IFN-γ and TNF-α by TGF-β. In the current paper, we compared weight, histopathology and immunological parameters during the acute and recovery phases of EAE to establish the best biomarker for clinical remission. Female Lewis rats were immunised with myelin basic protein (MBP) emulsified with complete Freund's adjuvant. Animals were evaluated daily for clinical score and weight prior to euthanisation. All immunised animals developed the expected characteristics of EAE during the acute phase, including significant weight loss and high clinical scores. Disease remission was associated with a significant reduction in clinical scores, although immunised rats did not regain their initial weight values. Brain inflammatory infiltrates were higher during the acute phase. During the remission phase, anti-myelin antibody levels increased, whereas TNF-α and IFN-γ production by lymph node cells cultured with MBP or concanavalin A, respectively, decreased. The most significant difference observed between the acute and recovery phases was in the induction of TNF-α levels in MBP-stimulated cultures. Therefore, the in vitro production of this cytokine could be used as a biomarker for EAE remission.

Thalidomide administration inhibits the clinical evolution of the experimental autoimmune encephalomyelitis (eae) in lewis rats: preliminar results

Multiple sclerosis (MS) is a chronic neurodegenerative inflammatory disease of the central nervous system. Several immunomodulatory agents have been used to prevent MS acute exacerbations. Tumor Necrosis factor alpha (TNFα) and interferon gamma (IFN-γ) are two major inflammatory mediators. Recently, we investigated in our laboratory the therapeutic value of thalidomide, a recognized TNF-α inhibitor, for the treatment of MS using the classical Lewis rat model of experimental autoimmune encephalomyelitis ( EAE). The experimental study revealed that thalidomide reduces the incidence of EAE development in 90% of the cases. Hence we hypothesized that thalidomide may be an important therapeutical tool for prevention of acute exacerbations of the MS.

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.

The immunomodulator glatiramer acetate influences spinal motoneuron plasticity during the course of multiple sclerosis in an animal model

The immunomodulador glatiramer acetate (GA) has been shown to significantly reduce the severity of symptoms during the course of multiple sclerosis and in its animal model - experimental autoimmune encephalomyelitis (EAE). Since GA may influence the response of non-neuronal cells in the spinal cord, it is possible that, to some extent, this drug affects the synaptic changes induced during the exacerbation of EAE. In the present study, we investigated whether GA has a positive influence on the loss of inputs to the motoneurons during the course of EAE in rats. Lewis rats were subjected to EAE associated with GA or placebo treatment. The animals were sacrificed after 15 days of treatment and the spinal cords processed for immunohistochemical analysis and transmission electron microscopy. A correlation between the synaptic changes and glial activation was obtained by performing labeling of synaptophysin and glial fibrillary acidic protein using immunohistochemical analysis. Ultrastructural analysis of the terminals apposed to alpha motoneurons was also performed by electron transmission microscopy. Interestingly, although the GA treatment preserved synaptophysin labeling, it did not significantly reduce the glial reaction, indicating that inflammatory activity was still present. Also, ultrastructural analysis showed that GA treatment significantly prevented retraction of both F and S type terminals compared to placebo. The present results indicate that the immunomodulator GA has an influence on the stability of nerve terminals in the spinal cord, which in turn may contribute to its neuroprotective effects during the course of multiple sclerosis.

Imunopatologia da encefalomielite auto-imune experimental murina mediada por linfócitos T / Immunopathology of the murine experimental autoimmune encephalomyelitis mediated by T Lymphocytes

A Esclerose Múltipla é uma doença crônica, inflamatória e desmielinizante do Sistema Nervoso Central. Embora a sua etiologia seja, ainda, desconhecida, supõe-se tratar-se de uma doença auto-imune mediada por células T CD4+ com perfil Th1. A Encefalomielite Auto-imune Experimental (EAE) é um modelo animal para estudar a Esclerose Múltipla. As características deste modelo são inflamações e desmielinização, se assemelhando à Esclerose Múltipla. A EAE permite avaliar parâmetros tais como linfócitos T CD4+ e T CD8+, linfócitos T regulatórios, moléculas co-estimulatórias, quimiocinas e etc. O objetivo deste estudo foi fazer uma revisão da literatura sobre imunopatologia da EAE murina mediada por linfócitos T.

Multiple Sclerosis is a chronic, inflammatory and demyelinating disease of the Central Nervous System. Although its etiology is still unclear, it is supposed a CD4+ T Helper-1- mediated autoimmune disease. Experimental Autoimmune Encephalomyelitis (EAE) is an animal model to study Multiple Sclerosis. The characteristics of this model are inflammation and demyelination similar to Multiple Sclerosis. EAE allows to assess parameters such as CD4+ and CD8+ T lymphocytes, regulatory T lymphocytes, costimulatory molecules, chemokines and so on. The aim of this study was to make a bibliographic revision of the murine EAE immunopathology mediated by T cells.

Resistance to experimental autoimmune encephalomyelitis development in Lewis rats from a conventional animal facility

Experimental autoimmune encephalomyelitis (EAE) is an inflammatory disease of the brain and spinal cord that is mediated by CD4+ T lymphocytes specific to myelin components. In this study we compared development of EAE in Lewis rats from two colonies, one kept in pathogen-free conditions (CEMIB colony) and the other (Botucatu colony) kept in a conventional animal facility. Female Lewis rats were immunized with 100 µl of an emulsion containing 50 µg of myelin, associated with incomplete Freund's adjuvant plus Mycobacterium butyricum. Animals were daily evaluated for clinical score and weight. CEMIB colony presented high EAE incidence with clinical scores that varied from three to four along with significant weight losses. A variable disease incidence was observed in the Botucatu colony with clinical scores not higher than one and no weight loss. Immunological and histopathological characteristics were also compared after 20 days of immunization. Significant amounts of IFN-gamma, TNF-alpha and IL-10 were induced by myelin in cultures from CEMIB animals but not from the Botucatu colony. Significantly higher levels of anti-myelin IgG1 were detected in the CEMIB colony. Clear histopathological differences were also found. Cervical spinal cord sections from CEMIB animals showed typical perivascular inflammatory foci whereas samples from the Botucatu colony showed a scanty inflammatory infiltration. Helminths were found in animals from Botucatu colony but not, as expected, in the CEMIB pathogen-free animals. As the animals maintained in a conventional animal facility developed a very discrete clinical, and histopathological EAE in comparison to the rats kept in pathogen-free conditions, we believe that environmental factors such as intestinal parasites could underlie this resistance to EAE development, supporting the applicability of the hygiene hypothesis to EAE.

Baicalin reduces the severity of experimental autoimmune encephalomyelitis

Scutellaria baicalensis Georgi is one of the important medicinal herbs widely used for the treatment of various inflammatory diseases in Asia. Baicalin (BA) is a bioactive anti-inflammatory flavone found abundantly in Scutellaria baicalensis Georgi. To explore the therapeutic potential of BA, we examined the effects of systemic administration of the flavone (5 and 10 mg/kg, ip) on relapsing/remitting experimental autoimmune encephalomyelitis (EAE) induced by proteolipid protein 139-151 in SJL/J mice, an experimental model of multiple sclerosis. The mice treated with PBS or BA at day -1 and for 3 consecutive days were observed daily for clinical signs of disease up to 60 days after immunization. In the PBS-EAE group, neurological scores were: incidence (100 percent), mean day of onset (8.0 ± 0.73), peak clinical score (3.0 ± 0.4), and cumulative disease index (141.8 ± 19.4). In the BA-EAE group (5 or 10 mg kg-1 day-1, respectively), incidence (95 or 90 percent), mean day of onset (9.0 ± 0.80 or 9.2 ± 0.75; P = 0.000), peak clinical score (2.2 ± 0.3 or 2.0 ± 0.3; P = 0.000), and cumulative disease index (75.9 ± 10.1 or 62.9 ± 8.4; P = 0.000) decreased, accompanied by the histopathological findings (decrease of dense mononuclear infiltration surrounding vascellum) for the spinal cord. Additionally, the in vitro effects of BA (5, 10, and 25 µM) on mononuclear cells collected from popliteal and inguinal lymph nodes of day-10 EAE mice were evaluated using an MTT reduction assay for cell proliferation, and ELISA to measure IFN-g and IL-4 cytokines. Compared with the control group, BA caused an increase in IL-4 (EAE-DMSO: 3.56 ± 0.42 pg/mL vs EAE-BA (5, 10, and 25 µM): 6.03 ± 1.1, 7.83 ± 0.65, 10.54 ± 1.13 pg/mL, respectively; P < 0.001); but inhibited IFN-g (EAE-DMSO: 485.76 ± 25.13 pg/mL vs EAE-BA (5, 10, and 25 µM): 87.08 ± 9.24, 36.27 ± 5.44, 19.18 ± 2.93 pg/mL, respectively; P < 0.001) and the proliferation of mononuclear cells (EAE-DMSO:...

Compromiso neuronal en esclerosis multiple / Neuronal injury in multiple sclerosis

La esclerosis múltiple (EM) ha sido considerada clásicamente como una enfermedad desmielinzante. Si bien el compromiso neurodegenerativo fue previamente descripto, sólo recientemente ha sido enfatizado. Por estudiosos recientes se ha identificado la degeneración axonal como el mayor determinante de discapacidad neurológica irreversible en pacientes con EM. El daño axonal se inicia tempranamente y permanece silente durante años, la discapacidad neurológica se desarrolla cuando se alcanza cierto umbral de pérdida axonal y los mecanismos de compensación se agotan. Se han propuesto tres hipótesis para explicar el daño axonal: 1) El daño es causado por un proceso inflamatorio, 2) Existe una excesiva acumulación de Ca2+ intra-axonal, 3) Los axones desmienlinizados evolucionan a un proceso degenerativo producto de la falta de soporte trófico provisto por la mielina o células formadoras de mielina. Si bien la EM fue tradicionalmente considerada como una enfermedad de la sustancia blanca, el proceso de desmielinización tambiém ocurre en la corteza cerebral

The concept of multiple sclerosis (MS) as a demyelinating disease is deeply ingrained. Although the existence of a neurodegenerative component has always been apparent, it has only recently become emphasized. Thus, in recent years several studies have identified axonal degeneration as the major determinant of irreversible neurological disability in patients with MS. Axonal injury begins at disease onset and remains clinically silent for many years; irreversible neurological disability develops when a threshold of axonal loss is reached and CNS compensatory mechanisms are exhausted. The precise mechanisms of axonal loss are poorly understood, and three hypotheses have been proposed: 1) The damage is caused by an inflammatory process, 2) There is an excessive accumulation of intra-axonal Ca2+, 3) Demyelinated axons undergo degeneration due to lack of trophic support by myelin, or myelin forming cells. Although MS has traditionally been regarded as a disease of white matter, demyelination can also occur in the cerebral cortex. Cortical lesions exhibit neuronal injury represented by dendritic and axonal transection as well as neuronal apoptosis. Because conventional nuclear magnetic resonance (NMR) is limited in its ability to provide specific information about axonal pathology in MS, new techniques such as, diffusion-weighted MRI, proton magnetic resonance spectroscopy, functional MRI, as well as novel techniques designed to measure atrophy have been developed to monitor MS evolution. Recognition that MS is in part a neurodegenerative disease should trigger critical rethinking on the pathogenic mechanisms of this disease and provides new targets for a rational treatment

Nitric oxide synthase activity and endogenous inhibitors in rats recovered from allergic encephalomyelitis

We have previously reported that in comparison with normal rats, the presence of experimental allergic encephalomyelitis (EAE) leads to decreased endogenous inhibitory activity (EIA) of Ca2+-dependent nitric oxide synthase (NOS) in both brain and serum, and increased expression of protein 3-nitrotyrosine (NT) in brain. In this work we show that animals recovered from the clinical signs of EAE are not different from controls in terms of either brain NOS activity, EIA of NOS, or NT expression. These results suggest that parallel to the reversal of the disease symptoms, a normalization of the production of nitric oxide and related species occurs.

Modulation of fibronectin expression in the central nervous system of Lewis rats with experimental autoimmune encephalomyelitis

Fibronectin (FN), a large family of plasma and extracellular matrix (ECM) glycoproteins, plays an important role in leukocyte migration. In normal central nervous system (CNS), a fine and delicate mesh of FN is virtually restricted to the basal membrane of cerebral blood vessels and to the glial limitans externa. Experimental autoimmune encephalomyelitis (EAE), an inflammatory CNS demyelinating disease, was induced in Lewis rats with a spinal cord homogenate. During the preclinical phase and the onset of the disease, marked immunolabelling was observed on the endothelial luminal surface and basal lamina of spinal cord and brainstem microvasculature. In the paralytic phase, a discrete labelling was evident in blood vessels of spinal cord and brainstem associated or not with an inflammatory infiltrate. Conversely, intense immunolabelling was present in cerebral and cerebellar blood vessels, which were still free from inflammatory cuffs. Shortly after clinical recovery minimal labelling was observed in a few blood vessels. Brainstem and spinal cord returned to normal, but numerous inflammatory foci and demyelination were still evident near the ventricle walls, in the cerebral cortex and in the cerebellum. Intense expression of FN in brain vessels ascending from the spinal cord towards the encephalon preceded the appearance of inflammatory cells but faded away after the establishment of the inflammatory cuff. These results indicate an important role for FN in the pathogenesis of CNS inflammatory demyelinating events occurring during EAE

Encefalomielite alérgica experimental: Modelo de doença inflamatória desmielinizante do SNC / Experimental allergic encephalomyelitis: Experimental model of DNS inflamatory demyelinating disease

Os autores enfocam a importância da quebra da barreira hematencefálica, alteração da bainha de mielina e protocolo experimental no processo da indução da encefalomielite alérgica experimental, uma doença inflamatória e desmielinizante do sistema nervoso central

Auto-imunidade como imunodeficiência / Autoimmunity as immunodeficiency

As doenças auto-imunes näo podem mais ser atribuídas à simples presença de clones linfocitários auto-reativos, porque esses clones podem ser encontrados em indivíduos sadios como componentes de redes idiotípicas normais. Por outro lado, sídromes similares ao lúpus eritematoso sistêmico (LES) podem ser induzidas em camundongos normais pela injeçäo de um idiotipo anti-DNA freqüentemente encontrado em pacientes de LES (16/6), que também é encontrado no soro normal. Em camundongos NZB/W, que desenvolvem espontaneamente uma síndrome lupóide, ocorrem taxas anormalmente elevadas da ativaçäo de um subtipo de linfócitos T (Th2), que podem ser responsáveis pela ativaçäo policlonal de linfócitos B, levando à produçäo de vários auto-anticorpos patogênicos. A encefalomielite alérgica experimental (EAE) pode ser induzida em camundongos pela injeçäo de clones de células T reativos com a proteína básica da mielina (MBP); pode também ser prevenida ou revertida, pela injeçäo de outros clones MBP-reativos. O processo fisiológico de ativaçäo de linfócitos T requer a apresentaçäo de peptídios ligados a produtos do MHC na membrana de linfócitos B ou de vários tipos de "células apresentadas". Há porém, exceçöes a essa regra. Interaçöes recíprocas diretas entre regiöes variáveis de receptores de linfócitos T e imunoglobulinas atuando como receptores em linfócitos B podem resultar na ativaçäo de ambas as células. Em doenças parasitárias crônicas, como a esquistossomose mansônica e a doença de Chagas, podem ocorrer idiotipos antiparasita capazes de ativar linfócitos T autólogos independentemente de processamento/apresentaçäo. Neste ensaio, sugerimos que o "pareamento independente" de linfócitos T e B, contornando a necessidade de processamento/apresentaçäo, pode ser importante na gênese de doenças auto-imunes e nas formas severas de parasitoses crônicas. A eficácia de injeçöes de imunoglobulinas normais poliespecíficas no tratamento de várias doenças auto-imunes também sugere que a restauraçäo da saúde resulta do restabelecimento de padröes normais de conectividade idiotípica