Controle da ativação do inflamassoma e do estresse oxidativo pela vitamina D na encefalomielite autoimune experimental (EAE)
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Data
2018-07-30
Autores
Oliveira, Larissa Ragozo Cardoso de
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Universidade Estadual Paulista (Unesp)
Resumo
A esclerose múltipla (EM) é uma doença inflamatória crônica e desmielinizante do Sistema Nervoso Central (SNC) que desencadeia diferentes graus de incapacidade física e cognitiva. Os tratamentos para a EM são baseados principalmente em drogas imunomoduladoras visando redução da gravidade e da frequência de recidivas, uma vez que não há cura para a doença. Estudos em modelo experimental de EM, denominado encefalomielite autoimune experimental (EAE) têm demonstrado o efeito imunomodulador da vitamina D (Vit D3) tanto na imunidade inata quanto na adaptativa. Neste contexto, nosso objetivo foi avaliar se a intervenção precoce com Vit D3 é capaz de bloquear a neuroinflamação em um modelo experimental de EM. Para isto, camundongos C57BL/6 fêmeas foram imunizados com MOG (glicoproteína da mielina do oligodendrócito) associada ao Adjuvante Completo de Freund e tratadas com Vit D3 por via intraperitoneal. A Vit D3 diminuiu, de forma significativa, a incidência e o escore clínico da doença. Este efeito protetor foi acompanhado da diminuição de entrada de linfócitos no SNC e também de redução no processo de desmielinização e expressão de MHCII em macrófagos e micróglia. A eficácia da Vit D3 também foi associada com controle local do estresse oxidativo, ou seja, nos animais tratados ocorreu normalização dos níveis de peroxidação lipídica e de proteína carbonil e também de enzimas antioxidantes (superóxido dismutase, catalase e glutationa peroxidase). A terapia com Vit D3 também determinou redução significativa na expressão gênica de NLRP3, caspase 1 e IL-1β locais, que são marcadores típicos de ativação do inflamassoma. Também constatamos que a terapia precoce com Vit D3 normalizou a barreira hematoencefálica, principalmente no nível da medula espinhal. Estes resultados indicam que uma intervenção precoce com Vit D3 é capaz de controlar o processo neuroinflamatório que caracteriza a imunopatogênese da EAE e poderia, portanto, ser explorada como terapia adjunta em pacientes com EM.
Multiple sclerosis (MS) is a chronic and demyelinating inflammatory disease of the Central Nervous System (CNS) that triggers different degrees of physical and cognitive disability. Treatments for MS are mainly based on immunomodulatory drugs that reduce severity and frequency of relapses. Studies in an experimental model of MS, called experimental autoimmune encephalomyelitis (EAE), have demonstrated the immunomodulatory effect of vitamin D (Vit D3) in both innate and adaptive immunity. In this context, our objective was to evaluate whether early intervention with Vit D3 was able to block neuroinflammation in EAE. Encephalomyelitis was induced in female C57BL / 6 mice by immunization with MOG (myelin oligodendrocyte glycoprotein) associated with Freund's Complete Adjuvant and two doses of pertussis toxin. Mice were treated with Vit D3 intraperitoneally. Treatment significantly decreased the incidence and clinical score of the disease. This protective effect was associate to decreased lymphocyte infiltration in the CNS and also reduced demyelination and MHCII expression in macrophages and microglia. Vit D3 also determined local control of oxidative stress, that is, normalization of the levels of lipid peroxidation and carbonyl protein and also of antioxidant enzymes (superoxide dismutase, catalase and glutathione peroxidase). Vit D3 therapy reduced NLRP3, caspase-1 and local IL-1β mRNA expression in the CNS. In addition, this precocious Vit D3 therapy normalized the blood-brain barrier, mainly at the spinal cord level. These results indicate that an early intervention with Vit D3 is able to control the neuroinflammatory process that characterizes the immunopathogenesis of EAE and could therefore be explored as adjunctive therapy in MS patients.
Multiple sclerosis (MS) is a chronic and demyelinating inflammatory disease of the Central Nervous System (CNS) that triggers different degrees of physical and cognitive disability. Treatments for MS are mainly based on immunomodulatory drugs that reduce severity and frequency of relapses. Studies in an experimental model of MS, called experimental autoimmune encephalomyelitis (EAE), have demonstrated the immunomodulatory effect of vitamin D (Vit D3) in both innate and adaptive immunity. In this context, our objective was to evaluate whether early intervention with Vit D3 was able to block neuroinflammation in EAE. Encephalomyelitis was induced in female C57BL / 6 mice by immunization with MOG (myelin oligodendrocyte glycoprotein) associated with Freund's Complete Adjuvant and two doses of pertussis toxin. Mice were treated with Vit D3 intraperitoneally. Treatment significantly decreased the incidence and clinical score of the disease. This protective effect was associate to decreased lymphocyte infiltration in the CNS and also reduced demyelination and MHCII expression in macrophages and microglia. Vit D3 also determined local control of oxidative stress, that is, normalization of the levels of lipid peroxidation and carbonyl protein and also of antioxidant enzymes (superoxide dismutase, catalase and glutathione peroxidase). Vit D3 therapy reduced NLRP3, caspase-1 and local IL-1β mRNA expression in the CNS. In addition, this precocious Vit D3 therapy normalized the blood-brain barrier, mainly at the spinal cord level. These results indicate that an early intervention with Vit D3 is able to control the neuroinflammatory process that characterizes the immunopathogenesis of EAE and could therefore be explored as adjunctive therapy in MS patients.
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Palavras-chave
Encefalomielite autoimune experimental, barreira hematoencefálica, Vitamina D, Inflamassoma, Estresse oxidativo, Experimental autoimmune encephalomyelitis, blood-brain barrier, vitamin D3, inflammasome, oxidative stress