RESUMEN
Multiple sclerosis (MS) is an inflammatory and demyelinating disease of the central nervous system (CNS). The persistent inflammation is being mainly attributed to local oxidative stress and inflammasome activation implicated in the ensuing demyelination and axonal damage. Since new control measures remain necessary, we evaluated the preventive and therapeutic potential of a beta-selenium-lactic acid derivative (LAD-ßSe), which is a source of organic selenium under development, to control experimental autoimmune encephalomyelitis (EAE) that is an animal model for MS. Two EAE murine models: C57BL/6 and SJL/J immunized with myelin oligodendrocyte glycoprotein and proteolipid protein, respectively, and a model of neurodegeneration induced by LPS in male C57BL/6 mice were used. The preventive potential of LAD-ßSe was initially tested in C57BL/6 mice, the chronic MS model, by three different protocols that were started 14 days before or 1 or 7 days after EAE induction and were extended until the acute disease phase. These three procedures were denominated preventive therapy -14 days, 1 day, and 7 days, respectively. LAD-ßSe administration significantly controlled clinical EAE development without triggering overt hepatic and renal dysfunction. In addition of a tolerogenic profile in dendritic cells from the mesenteric lymph nodes, LAD-ßSe also downregulated cell amount, activation status of macrophages and microglia, NLRP3 (NOD-like receptors) inflammasome activation and other pro-inflammatory parameters in the CNS. The high Se levels found in the CNS suggested that the product crossed the blood-brain barrier having a possible local effect. The hypothesis that LAD-ßSe was acting locally was then confirmed by using the LPS-induced neurodegeneration model that also displayed Se accumulation and downmodulation of pro-inflammatory parameters in the CNS. Remarkably, therapy with LAD-ßSe soon after the first remitting episode in SJL/J mice, also significantly downmodulated local inflammation and clinical disease severity. This study indicates that LAD-ßSe, and possibly other derivatives containing Se, are able to reach the CNS and have the potential to be used as preventive and therapeutic measures in distinct clinical forms of MS.
Asunto(s)
Antiinflamatorios/uso terapéutico , Sistema Nervioso Central/efectos de los fármacos , Encefalomielitis Autoinmune Experimental/tratamiento farmacológico , Inflamasomas/metabolismo , Microglía/patología , Esclerosis Múltiple/tratamiento farmacológico , Inflamación Neurogénica/tratamiento farmacológico , Selenio/uso terapéutico , Animales , Sistema Nervioso Central/patología , Modelos Animales de Enfermedad , Encefalomielitis Autoinmune Experimental/inmunología , Humanos , Ácido Láctico/química , Masculino , Ratones , Ratones Endogámicos C57BL , Esclerosis Múltiple/inmunología , Glicoproteína Mielina-Oligodendrócito/inmunología , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Inflamación Neurogénica/inmunología , Selenio/químicaRESUMEN
In the central nervous system (CNS), neuroinflammation, especially that modulated by the cell response of astrocytes and microglia, is associated with damage to neurons in neurodegenerative disorders such as Parkinson's disease, Alzheimer's disease and, Multiple Sclerosis. Lupeol is a dietary triterpene that has demonstrated biological activities as antioxidant. This study investigated the anti-inflammatory and neuroprotective effects of lupeol in an in vitro model of neuroinflammation in primary cerebellar cultures. Cultures were obtained from 6-day-old Wistar rats, subjected to inflammatory damage with lipopolysaccharide (LPS, 1⯵g/mL) and treated with lupeol (0.1⯵M). We observed, after a 48-hour treatment, through Fluorjade-B staining and immunocytochemistry (ICQ) for ßIII-tubulin, that lupeol induced neuroprotection in cultures submitted to inflammatory damage. On the other hand, through ICQ for GFAP, it was possible to observe that lupeol modulated the astrocyte morphology for Bergmann glia-like phenotype and, especially for velate astrocyte-like phenotype, both phenotypes associated with the neuroprotective profile. Moreover, RT-qPCR analysis showed that lupeol induced the down-regulation of the mRNA expression for proinflammatory markers TNF, iNOS and NLRP3, as well as the production of nitric oxide (method of Greiss), which were up-regulated by LPS, and also induced up-regulation of the mRNA expression for arginase and IL-6 mRNA. In addition, lupeol induced up-regulation of mRNA expression for neurotrophins GDNF and NGF and also for the sonic hedgehog-Gli pathway. Together, these results lead to the conclusion that lupeol inhibits neuroinflammation in cerebellar cultures and induces neuroprotection associated with the modulation of astrocyte response and expression of neurotrophic and inflammatory factors.
Asunto(s)
Antiinflamatorios/farmacología , Astrocitos/fisiología , Cerebelo/patología , Inflamación Neurogénica/tratamiento farmacológico , Triterpenos Pentacíclicos/farmacología , Animales , Astrocitos/efectos de los fármacos , Células Cultivadas , Modelos Animales de Enfermedad , Regulación de la Expresión Génica , Humanos , Mediadores de Inflamación/metabolismo , Interleucina-6/genética , Interleucina-6/metabolismo , Lipopolisacáridos/inmunología , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Factores de Crecimiento Nervioso/metabolismo , Inflamación Neurogénica/inmunología , Neuroprotección , Óxido Nítrico Sintasa de Tipo II/genética , Óxido Nítrico Sintasa de Tipo II/metabolismo , Ratas , Ratas Wistar , Tubulina (Proteína)/metabolismo , Factor de Necrosis Tumoral alfa/genética , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
It is well-established that bacterial lipopolysaccharides (LPS) can promote neuroinflammation through receptor Toll-like 4 activation and induces sickness behavior in mice. This phenomenon triggers changes in membranes lipid dynamics to promote the intracellular cell signaling. Desorption electrospray ionization mass spectrometry (DESI-MS) is a powerful technique that can be used to image the distribution of lipids in the brain tissue directly. In this work, we characterize the LPS-induced neuroinflammation and the lipid dynamics in C57BL/6 mice at 3 and 24â¯h after LPS injection. We have observed that intraperitoneal administration of LPS (5â¯mg/kg body weight) induces sickness behavior and triggers a peripheral and cerebral increase of pro- and anti-inflammatory cytokine levels after 3â¯h, but only IL-10 was upregulated after 24â¯h. Morphological analysis of hypothalamus, cortex and hippocampus demonstrated that microglial activation was present after 24â¯h of LPS injection, but not at 3â¯h. DESI-MS revealed a total of 14 lipids significantly altered after 3 and 24â¯h and as well as their neuroanatomical distribution. Multivariate statistical analyzes have shown that ions associated with phosphatidylethanolamine [PE(38:4)] and docosatetraenoic acid [FA (22:4)] could be used as biomarkers to distinguish samples from the control or LPS treated groups. Finally, our data demonstrated that monitoring cerebral lipids dynamics and its neuroanatomical distribution can be helpful to understand sickness behavior and microglial activation after LPS administration.
Asunto(s)
Lípidos/inmunología , Inflamación Neurogénica/inmunología , Neuroinmunomodulación/inmunología , Animales , Encéfalo/diagnóstico por imagen , Encéfalo/metabolismo , Corteza Cerebral/diagnóstico por imagen , Corteza Cerebral/metabolismo , Citocinas/metabolismo , Hipocampo/diagnóstico por imagen , Hipocampo/metabolismo , Hipotálamo/diagnóstico por imagen , Hipotálamo/metabolismo , Conducta de Enfermedad/fisiología , Lipopolisacáridos/administración & dosificación , Masculino , Ratones , Ratones Endogámicos C57BL , Microglía/inmunología , Transducción de Señal , Espectrometría de Masa por Ionización de Electrospray/métodosRESUMEN
Models of Parkinson's disease with neurotoxins have shown that microglial activation does not evoke a typical inflammatory response in the substantia nigra, questioning whether neuroinflammation leads to neurodegeneration. To address this issue, the archetypal inflammatory stimulus, lipopolysaccharide (LPS), was injected into the rat substantia nigra. LPS induced fever, sickness behavior, and microglial activation (OX42 immunoreactivity), followed by astrocyte activation and leukocyte infiltration (GFAP and CD45 immunoreactivities). During the acute phase of neuroinflammation, pro- and anti-inflammatory cytokines (TNF-α, IL-1ß, IL-6, IL-4, and IL-10) responded differentially at mRNA and protein level. Increased NO production and lipid peroxidation occurred at 168 h after LPS injection. At this time, evidence of neurodegeneration could be seen, entailing decreased tyrosine hydroxylase (TH) immunoreactivity, irregular body contour, and prolongation discontinuity of TH+ cells, as well as apparent phagocytosis of TH+ cells by OX42+ cells. Altogether, these results show that LPS evokes a typical inflammatory response in the substantia nigra that is followed by dopaminergic neurodegeneration.
Asunto(s)
Astrocitos/fisiología , Neuronas Dopaminérgicas/fisiología , Leucocitos Mononucleares/fisiología , Lipopolisacáridos/inmunología , Microglía/fisiología , Enfermedades Neurodegenerativas/inmunología , Inflamación Neurogénica/inmunología , Enfermedad de Parkinson/inmunología , Porción Compacta de la Sustancia Negra/inmunología , Tirosina 3-Monooxigenasa/inmunología , Enfermedad Aguda , Animales , Diferenciación Celular , Movimiento Celular , Células Cultivadas , Citocinas/metabolismo , Modelos Animales de Enfermedad , Humanos , Peroxidación de Lípido , Masculino , Ratas , Ratas WistarRESUMEN
We investigated morphological alterations induced by s.c. injection of 2.5 microg of Bothrops jararaca venom in rats. Intense disorganisation of collagen fibres was observed 1 min after the venom injection, particularly at regions near vessels and nerves. Mast cells were degranulated, and erythrocytes were seen leaving venules throughout the endothelial junctions. At this time, damaged endothelial cells were not observed. In rats envenomed as above, but immediately after cardiorespiratory failure induced by deep ether anaesthesia, alterations in the connective tissue structures, as previously described, were not observed. The mediation of this haemorrhage was investigated by injecting the venom into the foot pad of mice and compared to the mediation of oedema. Local haemorrhage was significantly reduced in mice pre-treated with capsaicin or guanethidine or submitted to a surgical section of sciatic and saphenous nerves. In these animals, oedema was not affected. Groups treated with methysergide or morphine showed both haemorrhage and oedema significantly reduced. Indomethacin or dexamethasone pre-treatments significantly reduced the oedema, but not the haemorrhage. Moreover, in animals treated with promethazine or mepyramine, oedema and haemorrhage were not affected. These data suggest that local haemorrhage induced by Bothrops jararaca venom is partially controlled by serotonin and neurohumoral mediators. Furthermore, results indicate that haemorrhage and oedema are mediated by different pharmacological systems.