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

Chemotactic factors known as chemokines play an important role in the pathogenesis of multiple sclerosis (MS). Transgenic expression of TNFalpha in the central nervous system (CNS) leads to the development of a demyelinating phenotype (TNFalpha-induced demyelination; TID) that is highly reminiscent of MS. Little is known about the role of chemokines in TID but insights derived from studying this model might extend our current understanding of MS pathogenesis and complement data derived from the classic autoimmune encephalomyelitis (EAE) model system. Here we show that in TID, chemokines and their receptors were significantly increased during the acute phases of disease. Notably, the CCL2 (MCP-1)-CCR2 axis and the closely related ligand-receptor pair CCR1-CCL3 (MIP-1alpha) were among the most up-regulated during disease. On the other hand, receptors like CCR3 and CCR4 were not elevated. This significant increase in the levels of chemokines/receptors correlated with robust immune infiltration of the CNS by inflammatory cells, i.e., macrophages, and immune cells particularly T and B cells. Immunostaining and confocal microscopy, along with in vitro studies revealed that astrocytes were a major source of locally produced chemokines and expressed functional chemokine receptors such as CCR2. Using an in vitro system we demonstrate that expression of CCR2 was functional in astrocytes and that signaling via this receptor lead to activation of NF-kB and Akt and was associated with increased astrocyte survival. Collectively, our data suggests that transgenic murine models of MS are useful to dissect mechanisms of disease and that in these models, up-regulation of chemokines and their receptors may be key determinants in TID.
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PMID:Role of astrocytes and chemokine systems in acute TNFalpha induced demyelinating syndrome: CCR2-dependent signals promote astrocyte activation and survival via NF-kappaB and Akt. 1794 91

Expression of MCP-1 in the central nervous system (CNS) is associated with various neuroinflammatory diseases, including multiple sclerosis (MS) and experimental autoimmune encephalomyelitis (EAE). In this study, we found that MCP-1 was decreased in the CNS but increased in the gut following oral administration of myelin basic protein (MBP) correlating with protection from EAE. To study the trafficking and the fate of T cells during oral tolerance, MBP-specific TCR transgenic (Tg) CD4(+) T cells were labeled using 5,6-carboxy-succinimidyl-fluorescein-ester (CFSE) and transferred intravenously to syngeneic B10.PL recipients before feeding with either MBP or PBS. We observed that the CFSE-labeled T cells traffic to the peripheral lymphoid tissue and the Peyer's patches (PP). The labeled T cells proliferate in vivo in both the lymph node and the PP 48h after MBP feeding, but the cells are maintained in the PP longer than in the LN. CFSE-labeled cells in the PP have high levels of CD69 and Fas expression which is accompanied by increased apoptosis after MBP feeding. Our observations suggest that oral administration of autoantigen induces an elevation of MCP-1 in the gut, early T cell trafficking and activation in the periphery and the PP, followed by deletion of autoreactive T cells in the PP.
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PMID:The Peyer's patch is a critical immunoregulatory site for mucosal tolerance in experimental autoimmune encephalomylelitis (EAE). 1800 71

Superantigens were suggested to play a role in the pathogenesis of different autoimmune diseases including multiple sclerosis (MS). Previously, it was demonstrated that local expression of the superantigen, staphylococcal enterotoxin A (SEA) in the brain of rats may lead to encephalitis which was amplified by using intravenous injection of concanavalin A (ConA)-activated splenocytes. In the present investigation, gene expression was studied in the rat brain 8 days after an injection of 50 mul of 1 mg/ml SEA or saline and 5 days after an intravenous injection of 1 x 10(7) ConA-activated spleen cells. Of 8800 genes investigated (Affymetrix, rat genome U34A), the expression of 106 genes was significantly and at least threefold increased with SEA, while the expression of 29 genes was decreased at least threefold. Increased gene expression was compatible with an intracerebral inflammatory response mediated by antigen-presenting cells and CD8+ T lymphocytes. Elevated chemokines comprised RANTES (CCL5), osteopontin, MCP-1 (CCL2) and CXCL10. Further, genes with increased expression were assigned to the extracellular matrix, microglia/macrophage cell elements, astrocytes (GFAP) and phagocytosis. There was considerable conformity between previously reported gene expression profiles for experimental autoimmune encephalomyelitis (EAE) or MS and the present findings. Our data are in line with the concept that T-cell superantigen locally expressed in the central nervous system induces an inflammatory response. Therefore, the study of gene expression profiles does not seem to allow clear conclusions with respect to the aetiology of central nervous system autoimmune diseases.
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PMID:Cerebral gene expression of superantigen encephalitis in the lewis rat induced by staphylococcal enterotoxin a. 1840 24

IL-33 is a novel member of the IL-1 cytokine family and a potent inducer of type 2 immunity, as mast cells and Th2 CD4+ T cells respond to IL-33 with the induction of type 2 cytokines such as IL-13. IL-33 mRNA levels are extremely high in the CNS, and CNS glia possess both subunits of the IL-33R, yet whether IL-33 is produced by and affects CNS glia has not been studied. Here, we demonstrate that pathogen-associated molecular patterns (PAMPs) significantly increase IL-33 mRNA and protein expression in CNS glia. Interestingly, IL-33 was localized to the nucleus of astrocytes. Further, CNS glial and astrocyte-enriched cultures treated with a PAMP followed by an ATP pulse had significantly higher levels of supernatant IL-1beta and IL-33 than cultures receiving any single treatment (PAMP or ATP). Supernatants from PAMP + ATP-treated glia induced the secretion of IL-6, IL-13, and MCP-1 from the MC/9 mast cell line in a manner similar to exogenous recombinant IL-33. Further, IL-33 levels and activity were increased in the brains of mice infected with the neurotropic virus Theiler's murine encephalomyelitis virus. IL-33 also had direct effects on CNS glia, as IL-33 induced various innate immune effectors in CNS glia, and this induction was greatly amplified by IL-33-stimulated mast cells. In conclusion, these results implicate IL-33-producing astrocytes as a potentially critical regulator of innate immune responses in the CNS.
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PMID:Induction of IL-33 expression and activity in central nervous system glia. 2936 Feb 1

The interaction between CC chemokine receptor 2 (CCR2) with monocyte chemoattractant proteins, such as MCP-1, regulates the activation and recruitment of inflammatory leukocytes. In this study, we characterized (S)-3-[3,4-difluoro-phenyl)-propyl]-5-isoxazol-5-yl-2-thioxo-2,3-dihydro-1H-imidazole-4-carboxyl acid methyl ester (JNJ-27141491) as a noncompetitive and orally active functional antagonist of human (h)CCR2. JNJ-27141491 strongly suppressed hCCR2-mediated in vitro functions, such as MCP-1-induced guanosine 5'-O-(3-[(35)S]thio)triphosphate binding; MCP-1, -3, and -4-induced Ca(2+) mobilization; and leukocyte chemotaxis toward MCP-1 (IC(50) = 7-97 nM), whereas it had little or no effect on the function of other chemokine receptors tested. The inhibition of CCR2 function was both insurmountable and reversible, consistent with a noncompetitive mode of action. JNJ-27141491 blocked the binding of (125)I-MCP-1 to human monocytes (IC(50) = 0.4 microM), but it failed to affect MCP-1 binding to mouse, rat, and dog cells (IC(50) > 10 microM). Therefore, transgenic mice, in which the mouse (m)CCR2 gene was replaced by the human counterpart, were generated for in vivo testing. In these mice, oral administration of JNJ-27141491 dose-dependently [5-40 mg/kg q.d. (once daily) or b.i.d.] inhibited monocyte and neutrophil recruitment to the alveolar space 48 h after intratracheal mMCP-1/lipopolysaccharide instillation. Furthermore, treatment with JNJ-27141491 (20 mg/kg q.d.) significantly delayed the onset and temporarily reduced neurological signs in an experimental autoimmune encephalomyelitis model of multiple sclerosis. Taken together, these results identify JNJ-27141491 as a noncompetitive, functional antagonist of hCCR2, capable of exerting oral anti-inflammatory activity in transgenic hCCR2-expressing mice.
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PMID:Pharmacological profile of JNJ-27141491 [(S)-3-[3,4-difluorophenyl)-propyl]-5-isoxazol-5-yl-2-thioxo-2,3-dihydro-1H-imidazole-4-carboxyl acid methyl ester], as a noncompetitive and orally active antagonist of the human chemokine receptor CCR2. 1859 82

We demonstrated recently that P8A-CCL2, a monomeric variant of the chemokine CCL2/MCP-1, is unable to induce cellular recruitment in vivo, despite full activity in vitro. Here, we show that this variant is able to inhibit CCL2 and thioglycollate-mediated recruitment of leukocytes into the peritoneal cavity and recruitment of cells into lungs of OVA-sensitized mice. This anti-inflammatory activity translated into a reduction of clinical score in the more complex inflammatory model of murine experimental autoimmune encephalomyelitis. Several hypotheses for the mechanism of action of P8A-CCL2 were tested. Plasma exposure following s.c. injection is similar for P8A-CCL2 and wild-type (WT) CCL2, ruling out the hypothesis that P8A-CCL2 disrupts the chemokine gradient through systemic exposure. P8A-CCL2 and WT induce CCR2 internalization in vitro and in vivo; CCR2 then recycles to the cell surface, but the cells remain refractory to chemotaxis in vitro for several hours. Although the response to P8A-CCL2 is similar to WT, this finding is novel and suggests that despite the presence of the receptor on the cell surface, coupling to the signaling machinery is retarded. In contrast to CCL2, P8A-CCL2 does not oligomerize on glycosaminoglycans (GAGs). However, it retains the ability to bind GAGs and displaces endogenous JE (murine MCP-1) from endothelial surfaces. Intravital microscopy studies indicate that P8A-CCL2 prevents leukocyte adhesion, while CCL2 has no effect, and this phenomenon may be related to the mechanism. These results suggest that oligomerization-deficient chemokines can exhibit anti-inflammatory properties in vivo and may represent new therapeutic modalities.
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PMID:An engineered monomer of CCL2 has anti-inflammatory properties emphasizing the importance of oligomerization for chemokine activity in vivo. 1866 71

Pituitary adenylyl cyclase-activating polypeptide (PACAP) is a widely expressed neuropeptide originally discovered in the hypothalamus. It closely resembles vasoactive intestinal peptide (VIP), a neuropeptide well known to inhibit macrophage activity, promote Th2-type responses, and enhance regulatory T cell (Treg) production. Recent studies have shown that administration of PACAP, like VIP, can attenuate dramatically the clinical and pathological features of murine models of autoimmune diseases such as experimental autoimmune encephalomyelitis (EAE) and collagen-induced arthritis. However, specific roles (if any) of endogenous VIP and PACAP in the protection against autoimmune diseases have not been explored. Here, we subjected PACAP-deficient mice to myelin oligodendrocyte glycoprotein (MOG(35-55))-induced EAE. MOG immunization of PACAP-deficient mice triggered heightened clinical and pathological manifestations of EAE compared to wild-type mice. The increased sensitivity was accompanied by enhanced mRNA expression of proinflammatory cytokines (TNFalpha, IL-6, IFN-gamma, IL-12p35, IL-23p19, and IL-17), chemokines (MCP-1/CCL2, MIP-1alpha/CCL3, and RANTES/CCL5), and chemotactic factor receptors (CCR1, CCR2, and CCR5), but downregulation of the anti-inflammatory cytokines (IL-4, IL-10, and TGF-beta) in the spinal cord. Moreover, the abundance of CD4(+)CD25(+)FoxP3(+) Tregs in lymph nodes and levels of FoxP3 mRNA in the spinal cord were also diminished. The reduction in Tregs was associated with increased proliferation and decreased TGF-beta secretion in lymph node cultures stimulated with MOG. These results demonstrate that endogenous PACAP provides protection in EAE and identify PACAP as an intrinsic regulator of Treg abundance after inflammation.
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PMID:Pituitary adenylyl cyclase-activating polypeptide is an intrinsic regulator of Treg abundance and protects against experimental autoimmune encephalomyelitis. 1919 Jan 79

We describe the generation of a fusion cytokine consisting of GM-CSF in tandem with N-terminal-truncated MCP-1 (6-76), hereafter GMME1. Treatment of activated T cells with recombinant GMME1 protein leads to proinflammatory cytokine reduction and apoptosis via a CCR2-restricted pathway. Similarly, cell death is triggered in macrophages cultured with GMME1, while an inhibition of Ab production from plasma cells is observed. Treatment of CD4 T cells derived from experimental autoimmune encephalomyelitis mice with GMME1 leads to p38 hyperphosphorylation, inhibition of p44/42, AKT and STAT3 phosphorylation, and caspase-3 activation. GMME1 administration to experimental autoimmune encephalomyelitis mice suppresses symptomatic disease and correlates with decreased levels of inflammatory cytokines including IL-17, MOG-specific Ab titers, and blockade of CD4 and CD8 T cell infiltration in spinal cords. We propose that GMME1 defines a new class of agents for the treatment of autoimmune ailments by selectively targeting lymphomyeloid cells expressing CCR2.
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PMID:Selective inhibition of CCR2 expressing lymphomyeloid cells in experimental autoimmune encephalomyelitis by a GM-CSF-MCP1 fusokine. 1923 56

Heme oxygenase-1 (HO-1) is a key cytoprotective, antioxidant, and antiinflammatory molecule. The pathophysiological functions of HO-1 have been associated with its enzymatic activities in heme catabolism. We have examined the immune functions of HO-1 by its conditional ablation in myeloid cells (HO-1(M-KO) mice). We demonstrate that myeloid HO-1 is required for the activation of interferon (IFN) regulatory factor (IRF) 3 after Toll-like receptor 3 or 4 stimulation, or viral infection. HO-1-deficient macrophages show reduced expression of IFN-beta and of primary IRF3 target genes encoding RANTES, IP-10 and MCP-1. In the presence of polyI:C, myeloid HO-1 knockout mice infected with Listeria monocytogenes, a model dependent on IFN-beta production, showed enhanced bacterial clearance and survival, whereas control mice succumbed to infection. Moreover, after induction of experimental autoimmune encephalomyelitis, mice with myeloid-specific HO-1 deficiency developed a higher incidence and an exacerbated, nonremitting clinical disease correlating with persistent activation of antigen-presenting cells, enhanced infiltration of Th17 cells, and a nonregressing myelin-specific T cell reactivity. Notably, these defects were rectified by exogenous administration of IFN-beta, confirming that HO-1 functions directly upstream of this critical immune pathway. These results uncover a novel direct function for myeloid HO-1 in the regulation of IFN-beta production, establishing HO-1 as a critical early mediator of the innate immune response.
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PMID:Myeloid heme oxygenase-1 regulates innate immunity and autoimmunity by modulating IFN-beta production. 1939 54

SHP-1 is a protein tyrosine phosphatase that negatively regulates cytokine signaling and inflammatory gene expression. Mice genetically lacking SHP-1 (me/me) display severe inflammatory demyelinating disease following intracranial inoculation with the BeAn strain of Theiler's murine encephalomyelitis virus (TMEV) compared to infected wild-type mice. Furthermore, SHP-1-deficient mice show a profound and predominant infiltration of blood-derived macrophages into the CNS following intracerebral injection of TMEV, and these macrophages are concentrated in areas of demyelination in brain and spinal cord. In the present study we investigated the role of SHP-1 in controlling CNS inflammatory demyelination following a peripheral instead of an intracerebral inoculation of TMEV. Surprisingly, we found that while wild-type mice were entirely refractory to intraperitoneal (IP) infection by TMEV, in agreement with previous studies, all SHP-1-deficient mice displayed profound macrophage neuroinvasion and macrophage-mediated inflammatory demyelination. Moreover, SHP-1 deficiency led to increased expression of inflammatory molecules in macrophages, serum, and CNS following IP infection with TMEV. Importantly, pharmacological depletion of peripheral macrophages significantly decreased both paralysis and CNS viral loads in SHP-1-deficient mice. In addition, peripheral MCP-1 neutralization attenuated disease severity, decreased macrophage infiltration into the CNS, and decreased monocyte numbers in the blood of SHP-1-deficient mice, implicating MCP-1 as an important mediator of monocyte migration between multiple tissues. These results demonstrate that peripheral TMEV infection results in a unique evolution of macrophage-mediated demyelination in SHP-1-deficient mice, implicating SHP-1 in the control of neuroinvasion of inflammatory macrophages and neurotropic viruses into the CNS.
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PMID:Central neuroinvasion and demyelination by inflammatory macrophages after peripheral virus infection is controlled by SHP-1. 1995 Nov 74


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