Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: UMLS:C0014070 (encephalomyelitis)
13,017 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Inflammatory diseases of the central nervous system, such as multiple sclerosis or experimental autoimmune encephalomyelitis, are characterized by adhesion of lymphocytes on cerebral microvascular endothelium, followed by transendothelial migration into the brain parenchyma. T lymphocyte adhesion to vascular endothelial cells is mediated by several types of adhesion molecules, including the integrin leukocyte function-associated molecule 1 and its endothelial counter receptor intercellular adhesion molecule 1 (ICAM-1), of the immunoglobulin superfamily. In order to understand the molecular mechanisms that support lymphocyte extravasation, we intended to investigate a putative role of ICAM-1 in signal transduction in brain microvessel endothelial cells. Here we describe, using a well differentiated rat brain endothelial cell line (RBE4 cells), that ICAM-1 activation by a specific monoclonal antibody, or by syngeneic encephalitogenic T cells, induces tyrosine phosphorylation of several proteins together with stimulation of the tyrosine kinase p60src activity. One of the major tyrosine-phosphorylated proteins, of 85 kDa, has been identified by immunoprecipitation and immunoblotting, as the recently described actin-binding protein, p60src substrate, cortactin. These findings demonstrate that ICAM-1 activation transduces signals in brain endothelial cells, which may lead to cytoskeleton changes and transendothelial migration of lymphocytes into the brain.
...
PMID:Intercellular adhesion molecule 1 activation induces tyrosine phosphorylation of the cytoskeleton-associated protein cortactin in brain microvessel endothelial cells. 790 3

Microglial cells are resident macrophages in the central nervous system (CNS) which serve specific functions in the defence of the CNS against microorganisms, the removal of tissue debris in neurodegenerative diseases or during normal development, and in autoimmune inflammatory disorders of the brain. Microglia express a cytokine-inducible isoform of nitric oxide synthase, which leads to the production of nitric oxide (NO). Since NO is highly toxic to neurons and oligodendrocytes, we were interested to test down-regulating neuropeptides and second messenger de-activators in order to identify novel antagonists of cytokine-induced NO production. We found that only the tyrosine kinase inhibitor methyl-2,5-dihydroxycinnamate suppressed cytokine-induced NO production by rat microglial cells and murine macrophages, while a range of other tyrosine kinase inhibitors, neuropeptides and growth factors was ineffective. Since NO production may play a role in the pathogenesis of experimental neuro-immunological disorders like experimental autoimmune encephalomyelitis and experimental autoimmune neuritis, our findings suggest a possible therapeutic role for tyrosine kinase inhibitors.
...
PMID:Inhibition of cytokine-inducible nitric oxide synthase in rat microglia and murine macrophages by methyl-2,5-dihydroxycinnamate. 880 92

Migration of lymphocytes from blood into the brain is a critical event in the pathogenesis of multiple sclerosis and its animal model, experimental autoimmune encephalomyelitis (EAE). Previous observations made in our laboratory showed that protein tyrosine kinase inhibitors were able to block lymphocyte adhesion to brain endothelium and prevent the entry of encephalitogenic T cell lines into the brain of SJL/J mice. Here we show that systemic administration of the protein tyrosine kinase inhibitor, tyrphostin AG490, blocks the development of actively induced EAE in a dose-dependent manner. Administration of 1 mg of drug daily significantly decreased the severity of the disease, while 3 mg of AG490 daily totally blocked the disease in 62% of treated animals, and in those that developed the disease, paralysis was delayed and clinical score was significantly reduced. Blood leukocytes isolated from mice treated with tyrphostin AG490 were less adhesive on VCAM-1 and fibronectin, when compared with control animals. AG490 treatment had no effect on the proliferation by antigen-stimulated peripheral lymph nodes cells. Interestingly, cells obtained from draining lymph nodes in AG490-treated animals and stimulated with antigen secreted two times more IFN-gamma and four times more IL-10, when compared with control animals, whereas no difference was observed in TNF-alpha production. Our results suggest that tyrphostin AG490 may have therapeutic potential by blocking tyrosine kinase activities involved in key mechanisms leading to demyelinating diseases of the central nervous system.
...
PMID:Tyrphostin AG490, a tyrosine kinase inhibitor, blocks actively induced experimental autoimmune encephalomyelitis. 984 95

Migration of lymphocytes from the blood into the brain is a critical event in the pathogenesis of experimental autoimmune encephalomyelitis. Lymphocyte adhesion to brain endothelium is the first step in lymphocyte entry into the central nervous system, leading subsequently to myelin damage and paralysis. In this paper we show that the tyrosine kinase inhibitor, tyrphostin AG490, prevents binding of freshly isolated mouse lymph node cells and of in vivo activated lymphocytes to endothelium of inflamed brain in Stamper-Woodruff adhesion assays. Moreover, AG490 inhibits adhesion of encephalitogenic T cell lines to purified ICAM-1 and VCAM-1, molecules implicated in T cell recruitment into the central nervous system. In contrast, 2-h treatment of T cell lines with high doses of tyrphostin AG490 have no effect on the viability, intracellular calcium elevation induced by Con A or TCR cross-linking, proliferation, or TNF production by Ag-stimulated T cell lines. Systemic administration of AG490 prevents the accumulation of leukocytes in the brain and the development of experimental autoimmune encephalomyelitis induced by proteolipid protein, peptide 139-151-specific T cell lines in SJL/J mice. Blood leukocytes isolated from mice treated with tyrphostin AG490 are less adhesive on purified very late Ag-4 ligands compared with adhesion of leukocytes from control animals. Our results suggest that inhibition of signaling pathways involved in lymphocyte adhesion may represent a novel therapeutic approach for demyelinating diseases.
...
PMID:Inhibition of experimental autoimmune encephalomyelitis by a tyrosine kinase inhibitor. 991 45

The production of nitric oxide by the inflammatory isoform of nitric oxide synthase (NOS2) in brain glial cells is thought to contribute to the causes and development of neurological diseases and trauma. We previously demonstrated that activation of a heat shock response (HSR) by hyperthermia reduced NOS2 expression in vitro, and in vivo attenuated the clinical and histological symptoms of the demyelinating disease experimental autoimmune encephalomyelitis (EAE; Heneka et al. [2001] J. Neurochem. 77:568-579). Benzoquinoid ansamycins are fungal-derived antibiotics with tyrosine kinase inhibitory properties, and which also induce a HSR by allowing activation of HS transcription factor HSF1. We now show that two members of this class of drugs (geldanamycin and 17-allylamino-17-demethoxygeldanamycin) also induce a HSR in primary rat astrocytes and rat C6 glioma cells. Both drugs dose-dependently reduced nitrite accumulation, NOS2 steady-state mRNA levels, and the cytokine-dependent activation of a rat 2.2-kB NOS2 promoter construct stably expressed in C6 cells. These inhibitory effects were partially reversed by quercetin, a bioflavonoid which prevents HSF1 binding to DNA and thus attenuates the HSR. Ansamycins increased mRNA levels of the inhibitory IkappaBalpha protein, suggesting that inhibition of NFkappaB activation could contribute to their suppressive effects. Finally, in C57BL/6 mice actively immunized to develop EAE, a single injection of geldanamycin at 3 days after immunization reduced disease onset by over 50%. These results indicate that ansamycins can exert potent anti-inflammatory effects on brain glial cells which may provide therapeutic benefit in neuroinflammatory diseases.
...
PMID:Suppressive effects of ansamycins on inducible nitric oxide synthase expression and the development of experimental autoimmune encephalomyelitis. 1183 13

TNF-alpha is a proinflammatory cytokine, abundantly expressed after myocardial infarction. It has been suggested that it exhibits myocardial suppressive and cytotoxic effects. AG-556 is a tyrosine kinase inhibitor synthesized based on its ability to reduce TNF-alpha production and cell toxicity, and to improve experimental models mediated by TNF-alpha (i.e., peritontitis and experimental autoimmune encephalomyelitis). Daily, for 7 days, rats were injected ip with either AG-556 dissolved in DMSO or with the control vehicle. Infarct size was determined in the hearts as well as in fibrous scar formation. Cardiac TNF-alpha expression was evaluated by ELISA and immunohistochemistry. Functional hemodynamic parameters were evaluated employing echocardiography prior to sacrifice. AG-556 treatment reduced MI size at 7 days with a parallel effect on fibrous tissue formation. TNF-alpha production by splenocytes was reduced upon AG-556 treatment, whereas no differences were evident between the groups with regard to myocardial cytokine expression. AG-556 attenuated the decrease in fractional shortening at the expense of preserving end systolic diameter. AG-556 has proven beneficial in reducing myocardial infarct size and attenuated consequent hemodynamic deterioration in the rat model. If reconfirmed, AG-556 may be of potential clinical use in post-MI patients.
...
PMID:Tyrphostin AG-556 reduces myocardial infarct size and improves cardiac performance in the rat. 1278 20

We have previously characterized a novel tyrosine kinase inhibitor peptide (Tkip) that is a mimetic of suppressor of cytokine signaling 1 (SOCS-1) and inhibits JAK2 phosphorylation of the transcription factor STAT1alpha. We show in this study that Tkip protects mice against experimental allergic encephalomyelitis (EAE), an animal model for multiple sclerosis. Mice are immunized with myelin basic protein (MBP) for induction of disease. Tkip (63 mug) administered every other day suppressed the development of acute EAE in 75% of New Zealand White (NZW) mice. Furthermore, Tkip completely protected SJL/J mice, which where induced to get the relapsing/remitting form of EAE, against relapses compared with control groups in which >70% of the mice relapsed after primary incidence of disease. Protection of mice by Tkip was similar to that seen with the type I IFN, IFN-tau. Protection of mice correlated with lower MBP Ab titers in Tkip-treated groups as well as suppression of MBP-induced proliferation of splenocytes taken from EAE-afflicted mice. Cessation of Tkip and IFN-tau administration resulted in SJL/J mice relapsing back into disease. Prolonged treatment of mice with Tkip produced no evidence of cellular toxicity or weight loss. Consistent with its JAK2 inhibitory function, Tkip also inhibited the activity of the inflammatory cytokine TNF-alpha, which uses the STAT1alpha transcription factor. The data presented in this study show that Tkip, like the type I IFN, IFN-tau, inhibits both the autoreactive cellular and humoral responses in EAE and ameliorates both the acute and chronic relapsing/remitting forms of EAE.
...
PMID:Treatment of mice with the suppressor of cytokine signaling-1 mimetic peptide, tyrosine kinase inhibitor peptide, prevents development of the acute form of experimental allergic encephalomyelitis and induces stable remission in the chronic relapsing/remitting form. 1621 Jun 11

Autoimmune diseases often result from inappropriate or unregulated activation of autoreactive T cells. Traditional approaches to treatment of autoimmune diseases through immunosuppression have focused on direct inhibition of T cells. In the present study, we examined the targeted inhibition of antigen-presenting cells as a means to downregulate immune responses and treat autoimmune disease. Dendritic cells (DCs) are the central antigen-presenting cells for the initiation of T cell responses, including autoreactive ones. A large portion of DCs are derived from hematopoietic progenitors that express FLT3 receptor (CD135), and stimulation of the receptor via FLT3 ligand either in vivo or in vitro is known to drive expansion and differentiation of these progenitors toward a DC phenotype. We hypothesized that inhibition of FLT3 signaling would thus produce an inhibition of DC-induced stimulation of T cells, thereby inhibiting autoimmune responses. To this end, we used small-molecule tyrosine kinase inhibitors targeted against FLT3 and examined the effects on DCs and their role in the promulgation of autoimmune disease. Results of our studies show that inhibition of FLT3 signaling induces apoptosis in both mouse and human DCs, and thus is a potential target for immune suppression. Furthermore, targeted inhibition of FLT3 significantly improved the course of established disease in a model for multiple sclerosis, experimental autoimmune encephalomyelitis, suggesting a potential avenue for treating autoimmune disease.
...
PMID:Inhibition of FLT3 signaling targets DCs to ameliorate autoimmune disease. 1627 21

Experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS), can be induced by the immunization of mice with myelin antigens in the form of myelin oligodendrocyte glycoprotein (MOG). Macrophage colony-stimulating factor (M-CSF) is required for the development of individual mononuclear phagocyte populations and is involved in the immune response. We previously reported that Ki20227 (N-{4-[(6,7-dimethoxy-4-quinolyl)oxy]-2-methoxyphenyl}-N'-[1-(1,3-thiazole-2-yl)ethyl]urea) is a highly selective M-CSF receptor (c-fms) tyrosine kinase inhibitor. In our current study, we investigated whether Ki20227 has suppressive effects upon EAE and indeed found that this drug significantly reduced the severity of this disease both preventively and therapeutically. Notably also, Ki20227 treatments inhibited the turn-over/expansion of myeloid cells provoked by the immunization and subsequent MOG-specific T cell responses in our EAE animal model. These findings suggest that M-CSF plays a pivotal role in the development of EAE and that Ki20227 and its derivatives may be candidate drugs for the treatment of human MS.
...
PMID:The selective M-CSF receptor tyrosine kinase inhibitor Ki20227 suppresses experimental autoimmune encephalomyelitis. 1837 4

Genes controlling immunopathologic diseases of differing etiopathology may also influence susceptibility to autoimmune disease. B10.D1-H2(q)/SgJ mice with a 2538 G-->A missense mutation in the tyrosine kinase-2 gene (Tyk2) are susceptible to Toxoplasma gondii yet resistant to autoimmune arthritis, unlike the wild-type B10.Q/Ai substrain. To understand whether Tyk2 is also important in a second autoimmune model, experimental allergic encephalomyelitis (EAE) was induced in B10.D1-H2(q)/SgJ (Tyk2(A)) and B10.Q/Ai (Tyk2(G)) mice with the myelin oligodendrocyte glycoprotein peptide 79-96. B10.D1-H2(q)/SgJ mice were resistant to EAE whereas B10.Q/Ai mice were susceptible, and a single copy of the Tyk2(G) allele conferred EAE susceptibility in F(1) hybrids. Furthermore, EAE resistance in B10.D1-H2(q)/SgJ mice was overridden when pertussis toxin (PTX) was used to mimic the effects of environmental factors derived from infectious agents. Numerous cytokines and chemokines were increased when PTX was included in the immunization protocol. However, only RANTES, IL-6, and IFN-gamma increased significantly with both genetic compensation and PTX treatment. These data indicate that Tyk2 is a shared autoimmune disease susceptibility gene whose genetic contribution to disease susceptibility can be modified by environmental factors. Single nucleotide polymorphisms like the one that distinguishes Tyk2 alleles are of considerable significance given the potential role of gene-by-environment interactions in autoimmune disease susceptibility.
...
PMID:A single nucleotide polymorphism in Tyk2 controls susceptibility to experimental allergic encephalomyelitis. 1949 1


1 2 Next >>

---