Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0014070 (encephalomyelitis)
13,017 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Activation of the vascular endothelium is important in the development of inflammation. Activated endothelial cells (EC) express surface markers not expressed by quiescent EC. These surface markers augment adhesion reactions and leukocyte migration. We examined microvessel EC activation longitudinally in experimental autoimmune encephalomyelitis (EAE) in Lewis rats. CNS microvessels were isolated at 0, 3, 7, 12, 20, and 30 days post-inoculation (PI). Normal and CFA-injected rat microvessels do not express activation antigens (Ag). Increased expression of major histocompatibility complex (MHC) class II molecule and intercellular adhesion molecule-1 (ICAM-1) were detected on CNS microvessels from immunized rats at 7 days PI, prior to development of clinical signs, and at 12 days PI. Enhanced MHC class I molecule was seen only at 12 days. MHC class II molecule expression was focally expressed along microvessel fragments. By 20 days PI, EC did not exhibit increased levels of any of the markers tested. Perivascular cells (possibly pericytes), however, were found to express MHC class II molecule and ICAM-1 up to 30 days PI. During the recovery phase isolated CNS microvessels from MBP-immunized rats were unresponsive to IFN gamma-mediated endothelial activation. Unresponsiveness was independent of IFN gamma concentration. These results suggest that the endothelium is restored to functional quiescence during the recovery phase of acute EAE.
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PMID:Recovery phase of acute experimental autoimmune encephalomyelitis in rats corresponds to development of endothelial cell unresponsiveness to interferon gamma activation. 872 61

This report describes two mechanisms by which virus infection can facilitate demyelinating autoimmune inflammation in the murine CNS. In the BALB/c mouse model of experimental allergic encephalomyelitis (EAE), peripheral infection with an avirulent strain (A7) of Semliki Forest virus (SFV) increased the morbidity to EAE by infecting endothelial cells and damaging the blood-brain barrier (BBB). An influx of hematogenous CD18+ (LFA-1+ and MAC-1+) cells into the CNS compartment was followed by a local increase in intercellular adhesion molecule 1 (ICAM-1) expression on the vascular endothelium. Although SFV A7 infection without EAE induction caused multifocal cerebral vascular endothelial cell infection and BBB damage followed by cellular infiltration and transient increase of ICAM-1, inflammation and demyelination of CNS white matter with classical clinical signs of EAE was observed only in EAE-induced BALB/c mice, whereas the control mice remained neurologically healthy. The upregulation of ICAM-1 after virus infection was detected after the CD18+ (LFA-1+ and MAC-1+) cells had infiltrated the CNS both after EAE induction and also in nonsensitized control mice. The observed increase in ICAM-1 expression was transient in nonsensitized SFV A7 infected mice just as in the cellular infiltrates in the CNS, but EAE induction resulted in prolongation in both the cellular infiltrates and upregulation of ICAM-1. Thus, SFV A7 infection causes BBB damage and prolongs increased ICAM-1 expression on brain endothelium. This results in increased and more rapid morbidity to EAE in mice which have been sensitized with neuroantigen. However, SFV A7-infected mice without neuroantigen sensitization remain neurologically healthy.
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PMID:Blood-brain barrier breakdown and increased intercellular adhesion molecule (ICAM-1/CD54) expression after Semliki Forest (A7) virus infection facilitates the development of experimental allergic encephalomyelitis. 896 3

MION-46L, a superparamagnetic iron oxide contrast agent, was investigated for its ability to increase the sensitivity of in vivo 3D MRI in the detection of brain lesions in a chronic experimental allergic encephalomyelitis (crEAE) mouse model. Lesion conspicuity on postcontrast 3D MRI was dramatically enhanced as compared to precontrast images corresponding to areas of inflammatory and demyelinating lesions. MION-46L could be detected on Prussian blue iron stain in the vascular endothelium, the perivascular space, and in macrophages within perivascular cuffs and areas of inflammation and demyelination. By taking advantage of the MION-46L induced macroscopic susceptibility effect, acute early lesions measuring only 100 microm in diameter could be detected. MION-46L enhanced MRI may be used to 1) provide a unique sensitivity in EAE lesion detection and correlate imaging to histopathology; 2) help to understand EAE lesion development and its underlying pathophysiology; and 3) eventually assist in preclinical screening of new experimental therapies directed at patients with multiple sclerosis (MS).
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PMID:Study of relapsing remitting experimental allergic encephalomyelitis SJL mouse model using MION-46L enhanced in vivo MRI: early histopathological correlation. 963 11

We examined the treatment effects of two structurally distinct phosphodiesterase type IV (PDE IV) inhibitors, BBB022 and rolipram, in murine and rat models of experimental autoimmune encephalomyelitis (EAE). Based on our data, we propose a mechanism of action which may supplement immunomodulatory effects of PDE IV inhibitors. In particular, PDE inhibitors promote elevation of intracellular cAMP levels, increasing the electrical resistance of endothelial monolayers by stabilizing intercellular junctional complexes. Such an effect on central nervous system (CNS) vascular endothelium has the potential to reduce disease severity in EAE, because both inflammatory cells and humoral factors readily cross a disrupted blood-brain barrier (BBB). In this report, we demonstrate the capacity of BBB022 and rolipram to decrease clinical severity of EAE. further, PDE IV inhibitors significantly reduced BBB permeability in the spinal cords of mice with EAE. These results provide evidence that PDE IV-inhibitors may exert therapeutic effects in EAE by modifying cerebrovascular endothelial permeability, reducing tissue edema as well as entry of inflammatory cells and factors.
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PMID:Treatment with BBB022A or rolipram stabilizes the blood-brain barrier in experimental autoimmune encephalomyelitis: an additional mechanism for the therapeutic effect of type IV phosphodiesterase inhibitors. 1040 65

In order to analyze a putative immunomodulatory effect of NGF in experimental autoimmune encephalomyelitis (EAE) of the Lewis rat, we transduced myelin basic protein (MBP)-specific CD4(+) T cells with a recombinant retrovirus encoding NGF. These T(MBP)NGF cells secreted high levels of NGF, along with an unaltered Th1-like cytokine pattern. Transfer studies showed that T(MBP)NGF cells were unable to mediate clinical EAE, when transferred alone, and, more important, they efficiently suppressed induction of clinical EAE by non-transduced MBP-specific T cells (T(MBP )cells). In contrast, NGF transduced ovalbumin-specific T cells, which secreted high NGF levels, did not affect EAE induction. Suppression of clinical EAE by T(MBP)NGF cells was associated with a general reduction of inflammatory CNS infiltrates, with a most pronounced decrease of the monocyte/macrophage component. Using a culture model of the endothelial blood-brain barrier (BBB), we found that NGF directly acts on blood-derived monocytes via the p75 NGF receptor, thus interfering with monocyte migration through the activated BBB endothelium. Our data establish NGF as an anti-inflammatory mediator interfering with T cell mediated autoimmune disease in the CNS. They further point to monocyte migration through blood vascular endothelium as one possible mechanism of NGF action.
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PMID:Anti-inflammatory activity of nerve growth factor in experimental autoimmune encephalomyelitis: inhibition of monocyte transendothelial migration. 1116 33

The role of Ab deposition and complement activation, especially the membrane attack complex (MAC), in the mediation of injury in experimental allergic encephalomyelitis (EAE) is not resolved. The course of active EAE in normal PVG rats was compared with that in PVG rats deficient in the C6 component of complement (PVG/C6(-)) that are unable to form MAC. Following immunization with myelin basic protein, PVG/C6(-) rats developed significantly milder EAE than PVG/C rats. The anti-myelin basic protein response was similar in both strains, as was deposition of C3 in spinal cord. C9 was detected in PVG/C rats but not in PVG/C6(-), consistent with their lack of C6 and inability to form MAC. In PVG/C6(-) rats, the T cell and macrophage infiltrate in the spinal cord was also significantly less than in normal PVG/C rats. There was also reduced expression of P-selectin on endothelial cells, which may have contributed to the reduced cellular infiltrate by limiting migration from the circulation. Assay of cytokine mRNA by RT-PCR in the spinal cords showed no differences in the profile of Th1 or Th2 cytokines between PVG/C and PVG/C6(-) rats. PVG/C rats also had a greater increase in peripheral blood white blood cell, neutrophil, and basophil counts than was observed in the PVG/C6(-). These findings suggest that the MAC may have a role in the pathogenesis of EAE, not only by Ig-activated MAC injury but also via induction of P-selectin on vascular endothelium to promote infiltration of T cells and macrophages into the spinal cord.
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PMID:Attenuation of experimental allergic encephalomyelitis in complement component 6-deficient rats is associated with reduced complement C9 deposition, P-selectin expression, and cellular infiltrate in spinal cords. 1197 Sep 70

VCAM-1 is an adhesion molecule that is important to leukocyte movement across the blood-brain barrier and is involved in the formation of destructive CNS inflammatory lesions in experimental autoimmune encephalomyelitis (EAE) and multiple sclerosis (MS). We examined VCAM-1 expression in the CNS of animals with passively induced EAE and found abundant expression not only on the CNS endothelium but also on astrocytes. We show that tumor necrosis factor receptor-1 (TNFR1) signaling is required for VCAM-1 expression by astrocytes, not the vascular endothelium. In addition, we demonstrate that VCAM-1 expression by astrocytes is crucial for T cell entry into the CNS parenchyma and is required for manifestation of neurological disease.
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PMID:TNFR1-dependent VCAM-1 expression by astrocytes exposes the CNS to destructive inflammation. 1514 10

In experimental autoimmune encephalomyelitis (EAE), intravenous transfer of activated CD4(+) myelin-specific T cells is sufficient to induce disease. Transferred T cells access the CNS parenchyma by trafficking across the blood brain barrier (BBB) vascular endothelium into the perivascular space, and then across the glial limitans that is made up of astrocytes and microglia. Flow cytometry analysis of cells isolated from CNS tissue does not distinguish between T cell populations at the various stages of migration. In this study, we have used GK1.5 (anti-CD4) treatment along with immunohistochemistry to distinguish between populations of T cells that are associated with the vasculature, T cells that have migrated into the perivascular space, and T cells in the parenchyma. We have also re-evaluated antigen specificity requirements of T cells as they are recruited to the CNS parenchyma. Activated myelin-specific T cells are restricted to the CNS vasculature for at least 24 h post transfer. MHC class II expression on the recipient is required for cells to traffic across the CNS vascular endothelium. Further, Con A-stimulated or non-CNS-specific (ovalbumin-specific) T cells fail to migrate into the perivascular space, and only enter the CNS parenchyma when co-transferred with myelin-specific T cells. Our results indicate that Th1 populations cannot accumulate in the perivascular (subarachnoid, Virchow-Robbins) space without a CNS antigen-specific signal.
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PMID:Defining antigen-dependent stages of T cell migration from the blood to the central nervous system parenchyma. 1576 50

Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system (CNS). Adhesion molecules play important roles in cell-cell and cell-extracellular matrix (ECM) interactions in inflammation. Blocking the interaction between inflammatory cells and vascular endothelia can prevent cell entry into tissues and harmful inflammatory responses, that is, autoimmunity, but could also limit immunosurveillance by anti-viral T cells in sites of infection or latency. Development of progressive multifocal leukoencephalopathy in patients treated with antibody against very late antigen (VLA)-4 prompted us to explore an alternative therapeutic approach. We used an antibody against the integrin alpha2, VLA-2, that interacts with ECM, not vascular endothelium. SJL/J mice were sensitized with myelin proteolipid protein (PLP)(139-151) peptide to induce experimental autoimmune encephalomyelitis (EAE), an animal model for MS. Treatment of mice with VLA-2 antibody suppressed clinical signs and CNS inflammation of EAE, when antibody was given immediately after disease onset. In contrast, VLA-4 or VLA-2 antibody treatment of mice during the priming or remission phase of EAE had minor effects on the disease's clinical course. No differences were found in lymphoproliferative responses to PLP(139-151) among treatment groups. Data suggest that blocking cell-ECM interactions can be an alternative therapy for MS.
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PMID:Modulation of experimental autoimmune encephalomyelitis by VLA-2 blockade. 1749 37

Calcium-activated potassium channels modulate calcium signaling cascades and membrane potential in both excitable and non-excitable cells. In this article we will review the physiological properties, the structure activity relationships of the existing peptide and small molecule modulators and the therapeutic importance of the three small-conductance channels KCa2.1-KCa2.3 (a.k.a. SK1-SK3) and the intermediate-conductance channel KCa3.1 (a.k.a. IKCa1). The apamin-sensitive KCa2 channels contribute to the medium afterhyperpolarization and are crucial regulators of neuronal excitability. Based on behavioral studies with apamin and on observations made in several transgenic mouse models, KCa2 channels have been proposed as targets for the treatment of ataxia, epilepsy, memory disorders and possibly schizophrenia and Parkinson's disease. In contrast, KCa3.1 channels are found in lymphocytes, erythrocytes, fibroblasts, proliferating vascular smooth muscle cells, vascular endothelium and intestinal and airway epithelia and are therefore regarded as targets for various diseases involving these tissues. Since two classes of potent and selective small molecule KCa3.1 blocker, triarylmethanes and cyclohexadienes, have been identified, several of these postulates have already been validated in animal models. The triarylmethane ICA-17043 is currently in phase III clinical trials for sickle cell anemia while another triarylmethane, TRAM-34, has been shown to prevent vascular restenosis in rats and experimental autoimmune encephalomyelitis in mice. Experiments showing that a cyclohexadiene KCa3.1 blocker reduces infarct volume in a rat subdural hematoma model further suggest KCa3.1 as a target for the treatment of traumatic and possibly ischemic brain injury. Taken together KCa2 and KCa3.1 channels constitute attractive new targets for several diseases that currently have no effective therapies.
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PMID:Modulators of small- and intermediate-conductance calcium-activated potassium channels and their therapeutic indications. 1758 55


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