Antagonizing astrocytic platelet activating factor receptor-neuroinflammation for total flavone of epimedium in response to cuprizone demyelination.

Demyelinating diseases of the central nervous system are characterized by recurrent demyelination and progressive neurodegeneration, but there are no clinical drugs targeting myelin regeneration or improving functional disability in the treatment of multiple sclerosis. Total flavone of Epimedium (TFE) is the main active components of Epimedium, which exhibits the beneficial biological activities in the treatment of diseases, but there is no report in the treatment of demyelinating disorder. The purpose of this study was to explore the therapeutic potential and possible mechanism of TFE in the treatment of demyelination. The results showed that TFE efficiently improved the behavioural performance and histological demyelination in cuprizone (CPZ)-induced demyelinating model. In terms of action, TFE increased astrocytes enrichment in corpus callosum, striatum and cortex, and promoted astrocytes to express neurotrophic factors. Furthermore, the expression of platelet-activating factor receptor (PAFR) in astrocytes was induced by CPZ feeding and LPS stimulation, accompanied by the increase of inflammatory cytokines TNF-α,IL-6 and IL-1ß. TFE declined the expression of PAFR, and inhibited inflammatory response. At the same time, TFE also antagonized PAFR activation and inflammatory response triggered by PAF, which further confirmed that TFE, as a new PAFR antagonist, inhibited the astrocyte-derived inflammatory response by antagonizing PAFR-neuroinflammation axis, thus contributing to myelin protection and regeneration.

Dietary naringenin supplementation attenuates experimental autoimmune encephalomyelitis by modulating autoimmune inflammatory responses in mice.

Autoimmune disease is highly prevalent in humans. Since conventional therapies have limited efficacy and often come with significant side effects, nutrition may provide an alternative and complementary approach to improving autoimmune disorders. Naringenin, a flavonoid found in citrus fruits, has been shown to have anti-inflammatory and antioxidant properties. Using the experimental autoimmune encephalomyelitis (EAE), a rodent model of human multiple sclerosis, we determined the effect of dietary naringenin (0.5%) on autoimmune disease. We found that naringenin reduced the incidence, delayed the onset, and attenuated the symptoms of EAE, which were accompanied by reduced immune cell infiltration and demyelination in the spinal cord. Additionally, the pro-inflammatory CD4+ T cell subsets Th1, Th9, and Th17 cells together with their respective transcription factors T-bet, PU.1, and RORγt were reduced in both the central nervous system (CNS) and lymph nodes of EAE mice fed naringenin while no difference was found in Th2 and regulatory T cell (Treg) populations in either CNS or lymph nodes between the two groups. We further showed that pathologic T cell proliferation induced by ex vivo re-stimulation with MOG35-55 and proinflammatory cytokines IL-6 and TNF-α were lower in naringenin-fed mice than in the control mice. Additionally, we found that naringenin treatment inhibited mRNA expression of CXCL10 (Th1 recruiting chemokine), vascular cell adhesion molecule-1 (VCAM-1), and VLA-4 (VCAM-1 ligand) in the CNS of EAE mice. Altogether, these results indicate that naringenin may have a potential to ameliorate autoimmune disease by favorably modulating autoimmune response.

[Delayed neurological syndrome following carbon monoxide poisoning]. / Síndrome neurológico tardío tras intoxicación por monóxido de carbon.

INTRODUCTION: Poisoning by carbon monoxide is the most frequent form of intoxication in our milieu as a result of exposure to poisonous gases. The effects of carbon monoxide poisoning are not limited to acute exposure, since, following apparent recovery from the acute intoxication, neurological or behavioural disorders may appear. PATIENTS AND METHODS: A study was conducted to examine the cases of carbon monoxide poisoning that had occurred in a healthcare area of 80,000 inhabitants over a 10-year period. These patients were then submitted to a follow-up to appraise the appearance of delayed neurological syndrome (DNS) and its relationship with different variables in the initial exposure to the carbon monoxide, in the treatment that was administered or in the severity of the intoxication. RESULTS AND CONCLUSIONS: It was observed that around 9.1% of those intoxicated by carbon dioxide detected within the healthcare district of Salnés went on to develop DNS, which is more frequent in patients with severe analytical criteria and very unlikely in those who do not have them. Patients with DNS did not express any clinical or analytical manifestations that differed from those who did not have the syndrome; no differences were observed in relation to the oxygen therapy that was administered. The rate of DNS within the healthcare district of Salnés between 2002 and 2012 is 0.84 cases per 100,000 inhabitants per year.

TITLE: Sindrome neurologico tardio tras intoxicacion por monoxido de carbono.Introduccion. La intoxicacion por monoxido de carbono es la mas frecuente en nuestro medio a consecuencia de la exposicion a gases toxicos. Los efectos de la intoxicacion por monoxido de carbono no se limitan a la exposicion aguda porque, tras la aparente recuperacion de la intoxicacion, pueden aparecer alteraciones neurologicas o del comportamiento. Pacientes y metodos. Se realizo un estudio de las intoxicaciones por monoxido de carbono en un area sanitaria de 80.000 habitantes durante un periodo de 10 años. Posteriormente se hizo un seguimiento de estos pacientes y se valoro la aparicion de sindrome neurologico tardio (SNT) y su relacion con diferentes variables en la exposicion inicial al monoxido de carbono, en el tratamiento administrado o en la gravedad de la intoxicacion. Resultados y conclusiones. Se observo que el 9,1% de los intoxicados por monoxido de carbono detectados en el area sanitaria de Salnes desarrollan el SNT, que es mas frecuente en los pacientes con criterios analiticos de gravedad y muy poco probable en los que no los tienen. Los pacientes con SNT no expresaron manifestaciones clinicas ni analiticas diferentes a los que no presentaron el sindrome; tampoco se observaron diferencias en relacion con la terapia con oxigeno administrada. La tasa de SNT en el area sanitaria de Salnes entre 2002 y 2012 es de 0,84 casos por 100.000 habitantes y año.

[Role of vitamin D in the physiopathology of neurodegenerative diseases]. / Rôle de la vitamine D dans la physiopathologie des maladies neurodégénératives.

The involvement of vitamin D in brain function has been discovered in the past 25 years by epidemiological and fundamental studies. Research on neurodegenerative diseases and their animal or cellular models unveiled converging lines of evidence indicating that hypovitaminosis D is not just an effect of the progression of neurodegenerative diseases, but truly an aggravating co-factor, sometimes very closely related to their physiopathology. Vitamin D is a steroid hormone capable of regulating the expression of hundreds of genes through both genetic and epigenetic mechanisms. This reflects the highly pleiotropic nature of its action in its conventional bone and phosphocalcic metabolism targets. Its role in the central nervous system and neurodegenerative diseases makes no exception to this rule. Here we focus on the identified role and mechanisms of vitamin D in multiple sclerosis, Alzheimer's disease and Parkinson's disease. The important prevalence of hypovitaminosis D under our latitudes in general and in at-risk groups in particular, its easy evaluation and correction, and the results of early clinical studies, suggest that vitamin D supplementation could usefully complement our therapeutic armory to fight these diseases.

Epimedium flavonoids ameliorate experimental autoimmune encephalomyelitis in rats by modulating neuroinflammatory and neurotrophic responses.

The present study was designed to determine whether epimedium flavonoids (EF) had effect on the development of experimental autoimmune encephalomyelitis (EAE) in rats and to elucidate its underlying mechanisms. EAE was induced by immunization of adult female Lewis rats with partially purified myelin basic protein (MBP) prepared from guinea-pig spinal cord homogenate. EF was administrated intragastrically once a day after immunization until day 14 post immunization (p.i.). Histopathological staining, enzyme-linked immunosorbent assay (ELISA), biochemical methods and western blotting approaches were used to evaluate the disease incidence and severity, neuroinflammatory and neurotrophic response in the central nervous system (CNS). Intragastrical administration of EF (20 and 60 mg/kg) significantly reduced clinical score of neurological deficit in EAE rats; alleviated demyelination and inflammatory infiltration; and inhibited astrocytes activation, production of proinflammatory molecules such as interleukin-1ß (IL-1ß), tumour necrosis factor-α (TNF-α), nitric oxide (NO) and nuclear transcription factor (NF-κB) in the spinal cord of EAE rats. Treatment with EF also enhanced the expression of 2', 3'-cyclic nucleotide 3'-phosphohydrolase (CNPase) and nerve growth factor (NGF), increased the number of oligodendrocytes and protected the ultrastructure of myelin sheaths and axons in the spinal cord of EAE rats. Our results showed that EF inhibited the development of partial MBP-induced EAE in rats. This effect involved reducing neuroinflammation and enhancing myelination and neurotrophins and our findings suggest that EF may be useful for the treatment of multiple sclerosis.

Atorvastatin ameliorates experimental autoimmune neuritis by decreased Th1/Th17 cytokines and up-regulated T regulatory cells.

Statins have anti-inflammatory and immune-regulating properties. To investigate the effects of atorvastatin on experimental autoimmune neuritis (EAN), an animal model of Guillain-Barré syndrome (GBS), atorvastatin was administered to Lewis rats immunized with bovine peripheral myelin in complete Freund's adjuvant. We found that atorvastatin ameliorated the clinical symptoms of EAN, decreased the numbers of inflammatory cells as well as IFN-γ(+) and IL-17(+) cells in sciatic nerves, decreased the CD80 expression and increased the number of CD25(+)Foxp3(+) cells in mononuclear cells (MNC), and decreased the levels of IFN-γ in MNC culture supernatants. These data provide strong evidence that atorvastatin can act as an inhibitor in EAN by inhibiting the immune response of Th1 and Th17, decreasing the expression of co-stimulatory molecule, and up-regulating the number of T regulatory cells. These data demonstrated that statins could be used as a therapeutic strategy in human GBS in future.

Administration of dehydroepiandrosterone ameliorates experimental autoimmune neuritis in Lewis rats.

Dehydroepiandrosterone (DHEA) is an abundant adrenal steroid in serum of humans, and has been reported to have anti-inflammatory, anti-proliferative, and certain immune-regulating properties. Experimental autoimmune neuritis (EAN) is a Th1 cell-mediated animal model of Guillain-Barré syndrome (GBS) in humans. In the present study, DHEA was administered subcutaneously to Lewis rats immunized with bovine peripheral myelin (BPM) in Freund's complete adjuvant. Rats treated with DHEA displayed significant delay in onset, decreased inflammatory cell infiltration in the PNS. Benefit was associated with significant decreases in numbers of IFN-gamma and TNF-alpha expressing cells in the PNS, BPM-stimulated T cell proliferation and IFN-gamma, TNF-alpha-secretion in the spleen cells. Only 2 mg DHEA-treated EAN rats decreased peak clinical score. No significant difference of supernatant IL-10 was found among the treatment and control groups. These results suggest that DHEA can ameliorate the severity of EAN by suppressing the proliferation of autoreactive T cell and expression of pro-inflammatory cytokines.

Polyethylene glycol-conjugated immunoliposomes specific for olfactory ensheathing glial cells.

A novel immunoliposome delivery system was developed for directed transport into cultured olfactory epithelium cells. Monoclonal antibodies against glial fibrillary acidic protein (GFAP) served as a vector. Fluorescence microscopy showed that the target cells are specifically stained with Dil dye incorporated into liposomal membranes. This transport system holds promise for the delivery of bioactive substances to olfactory epithelial cells and modulation of their capacity to stimulate axonal regeneration.

Andrographolide interferes with T cell activation and reduces experimental autoimmune encephalomyelitis in the mouse.

Andrographolide is a bicyclic diterpenoid lactone derived from extracts of Andrographis paniculata, a plant indigenous to South Asian countries that shows anti-inflammatory properties. The molecular and cellular bases for this immunomodulatory capacity remain unknown. Here, we show that andrographolide is able to down-modulate both humoral and cellular adaptive immune responses. In vitro, this molecule was able to interfere with T cell proliferation and cytokine release in response to allogenic stimulation. These results were consistent with the observation that T cell activation by dendritic cells (DCs) was completely abolished by exposing DCs to andrographolide during antigen pulse. This molecule was able to interfere with maturation of DCs and with their ability to present antigens to T cells. Furthermore, in vivo immune responses such as antibody response to a thymus-dependent antigen and delayed-type hypersensitivity were drastically diminished in mice by andrographolide treatment. Finally, the ability of andrographolide to inhibit T cell activation was applied to interfere with the onset of experimental autoimmune encephalomyelitis (EAE), an inflammatory demyelinating disease of the central nervous system that is primarily mediated by CD4(+) T cells and serves as an animal model for human multiple sclerosis. Treatment with andrographolide was able to significantly reduce EAE symptoms in mice by inhibiting T cell and antibody responses directed to myelin antigens. Our data suggest that andrographolide is able to efficiently block T cell activation in vitro, as well as in vivo, a feature that could be useful for interfering with detrimental T cell responses.

The progression of neuronal, myelin, astrocytic, and immunological changes in the rat brain following exposure to aurothioglucose.

Aurothioglucose (ATG) is presently employed both by clinicians in the treatment of advanced rheumatoid arthritis and by neuroscience researchers to generate lesions around the circumventricular organs (CVOs) of rodent brains, resulting in obese animals. Although the existence of such lesions is well documented, there is relatively little information concerning the changes over time of the different cell types in the regions surrounding the CVOs. To address this question, specific markers allowing identification of four distinct cellular populations were used to characterize respective changes over time. Generally, regions adjacent to the CVOs were more vulnerable than the CVOs themselves, while more caudal structures were more frequently lesioned than more anterior CVO regions. Vascular and glial cells appeared to be the initial targets of ATG, while neuronal cell death occurred subsequent to the inflammatory response. The results of this study help resolve the mechanism of ATG toxicity as reflected by a cascade of pathologies that is consistent with disparate cell types exhibiting specific changes at specific times.

Factors modifying the migration of lymphocytes across the blood-brain barrier.

Characterising the factors that control the entry of leucocytes into tissue in response to inflammatory or microbial insult continues to generate considerable interest. Of all the tissues studied it is probably that of the CNS which is the most fascinating because of the specialised properties of its blood vessel walls, which constitute the blood-brain barrier (BBB). In health, very few leucocytes penetrate the BBB but in disorders such as MS the barrier becomes compromised with the result that there is an intense infiltration of the CNS by T lymphocytes whose subsequent activity appears to underlie the onset and progression of disease. The purpose of this article is to summarise and assess recent literature pertaining to how lymphocytes bind to cerebral endothelial cells, migrate across the blood vessel walls and enter the CNS parenchyma. Particular emphasis is devoted to the cellular and molecular aspects of these events and addressing the questions of whether certain subsets of circulating T lymphocytes are more favourably disposed than others to CNS infiltration and whether entry is dependent upon the initial expression of distinct groups of adhesion molecules and upon the generation of chemotactic factors. This article also focuses upon identifying the key stages of lymphocyte migration across the BBB and their susceptibility to antagonism by therapeutic agents. It is intended that the review will provide a useful source of information and offer additional insights into the mechanisms controlling lymphocyte passage across the BBB during pathological disturbance.

The neuroimmunology of multiple sclerosis.

The aim of this clinical review is to highlight recent advances in immunology, as well as new information from selected other areas, which have led to a better appreciation of the neuroimmunologic mechanisms involved in Multiple sclerosis (MS). New data on immunopathology, the cytokine network, and the role of oligodendrocytes, lymphocytes, and endothelial cells in this disease, have produced novel therapeutic approaches. New information on clinical course and neuroimaging disease features, as well as the role of genetic factors and infectious agents, have also improved our understanding of the immune basis for MS.

Treatment of experimental allergic neuritis with nedocromil sodium.

Peripheral nervous system mast cells degranulate early in the development of experimental allergic neuritis (EAN). This degranulation is associated with the release of vasoactive amines, chemoattractants and myelinolytic proteases which could provide a focus for inflammatory demyelination. To further assess the importance of mast cell degranulation in the development of EAN, we have treated Lewis rats inoculated with peripheral nervous system myelin and complete Freund's adjuvant, with nedocromil sodium, an anti-inflammatory drug with mast cell stabilizing properties. Treatment with nedocromil sodium (100-150 mg/kg), 3 times daily, starting on day 7 post-inoculation, significantly decreases the incidence and the severity of the disease. Histological examination of sciatic nerves confirms the absence of subclinical disease in successfully treated animals. The possible mode of action of the drug is discussed.

Peripheral nerve demyelination in rabbits after inoculation with Freund's complete adjuvant alone or in combination with lipid haptens.

The pathology of demyelination in rabbits with experimental allergic neuritis (EAN) or galactocerebroside-induced neuritis was compared to that in rabbits inoculated with either an emulsion of lipid haptens (gangliosides, lecithin and cholesterol) and Freund's complete adjuvant or Freund's complete adjuvant (FCA) alone. In rabbits inoculated with bovine peripheral myelin in FCA, perivenular demyelination associated with infiltrates of lymphocytes and macrophages occurred after 30 days, while those animals inoculated with galactocerebroside (GC) in Freund's adjuvant did not develop lesions until 60-90 days. GC rabbits had demyelination and severe nerve edema without cellular infiltrates. In rabbits inoculated with FCA alone, demyelination was restricted to ganglia and proximal nerve roots. Myelin basic protein (MBP) and GC antibodies from EAN, GC and lipid hapten-inoculated rabbits were detected by ELISA in sera at all post-inoculation time points. Appreciable P0 and P2 antibody titers were detected only in EAN animals. The results indicate that Freund's complete adjuvant alone or in combination with lipid haptens is capable of producing neuropathic effects in the rabbit independent of those produced by EAN or galactocerebroside neuritis.

Murine cortical brain cells are autoantigenic from a distinct developmental stage onwards.

The expression of autoantigens on murine cortical brain cells and their first appearance during development was studied. Autoreactivity was analyzed by weight increase and lymphocyte proliferation in the popliteal lymph node (PLN). Cortical brain cells or defined plasma membrane preparations were injected s.c. without adjuvant into syngeneic recipients. Weak, but significant T cell-dependent PLN enlargement was triggered with brain cells from adult mice. A stronger reaction could be elicited with one defined fraction of purified plasma membranes. The earliest appearance of the antigenic material in the plasma membrane fraction was observed on day 15 after birth. This time point correlates exactly with the completion of the blood-brain barrier in large parts of the central nervous system.

The significance of circulating and cell-bound antibodies in experimental allergic encephalomyelitis.

Conjugates of horseradish peroxidase with myelin basic protein (BP) of guinea pig or Lewis rat were used to identify antibody-containing cells in draining lymph nodes during experimental allergic encephalomyelitis (EAE). Peroxidase activity was revealed for light and electron microscopic preparations with the diaminobenzidine reaction of Graham and Karnovsky. Basic proteins (BP) were also iodinated with (125)I for determination of circulating antibody against BP by radio-immunoassay of (125)I BP using coprecipitation with antirat IgG or with antirat serum proteins. Encephalitogenicity was lost after conjugation of guinea pig BP or Lewis rat BP with peroxidase, whereas iodination did not affect the encephalitogenicity of guinea pig or Lewis rat BPs. EAE was induced in Lewis rats with guinea pig or Lewis rat spinal cord BPs in complete Freund's adjuvant. Draining lymph nodes were studied by light and electron microscopy during the course of the immune reaction, and cells with specific antibody against BP were identified with the use of BP-horseradish peroxidase conjugates. Lymph node sections from animals immunized with high antigen doses (500 mug) showed numerous plasma cells with intracellular antibody against BP in medullary cords 10 days after immunization and 4 days prior to histologic appearance of EAE. Numbers of positive cells correlated with levels of circulating antibody against BP. Immunization with a low antigen dose (5 mug) resulted in EAE, few or no antibody-containing cells, and significantly lower levels of circulating antibody. Brown Norwegian rats, a strain resistant to EAE, immunized with 500 mug of BP had positive cells in draining lymph nodes and high levels of circulating antibody against BP in the absence of histologic evidence of EAE. Lewis rats injected with Lewis rat small BP failed to develop EAE. Nevertheless, these animals showed levels of circulating antibody and antibody-containing cells similar to those of animals which developed EAE after injection of the mixture of Lewis rat large and small BP. It is concluded that although the BP-peroxidase labeling method reveals cells with specific anti-BP antibody, these cells are probably unrelated to EAE. The lack of correlation between EAE induced by low antigen doses and levels of circulating anti-BP antibody (determined with the use of highly encephalitogenic (125)I-BP) suggests that effector cells can be stimulated at low antigen doses, but higher antigen doses are required to induce the production of levels of circulating antibody detectable by the method of immune coprecipitation.