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Microglial Cell Line (microglial + cell_line)
Selected AbstractsLipopolysaccharide is a frequent and significant contaminant in microglia-activating factorsGLIA, Issue 1 2008Jonathan R. Weinstein Abstract Lipopolysaccharide (LPS/endotoxin) is a potent immunologic stimulant. Many commercial-grade reagents used in research are not screened for LPS contamination. LPS induces a wide spectrum of proinflammatory responses in microglia, the immune cells of the brain. Recent studies have demonstrated that a broad range of endogenous factors including plasma-derived proteins and bioactive phospholipids can also activate microglia. However, few of these studies have reported either the LPS levels found in the preparations used or the effect of LPS inhibitors such as polymyxin B (PMX) on factor-induced responses. Here, we used the Limulus amoebocyte lysate assay to screen a broad range of commercial- and pharmaceutical-grade proteins, peptides, lipids, and inhibitors commonly used in microglia research for contamination with LPS. We then characterized the ability of PMX to alter a representative set of factor-induced microglial activation parameters including surface antigen expression, metabolic activity/proliferation, and NO/cytokine/chemokine release in both the N9 microglial cell line and primary microglia. Significant levels of LPS contamination were detected in a number of commercial-grade plasma/serum- and nonplasma/serum-derived proteins, phospholipids, and synthetic peptide preparations, but not in pharmaceutical-grade recombinant proteins or pharmacological inhibitors. PMX had a significant inhibitory effect on the microglia-activating potential of a number of commercial-, but not pharmaceutical-grade, protein preparations. Novel PMX-resistant responses to ,2 -macroglobulin and albumin were incidentally observed. Our results indicate that LPS is a frequent and significant contaminant in commercial-grade preparations of previously reported microglia-activating factors. Careful attention to LPS levels and appropriate controls are necessary for future studies in the neuroinflammation field. © 2007 Wiley-Liss, Inc. [source] Downregulation of inducible nitric oxide synthetase by neurotrophin-3 in microgliaJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 2 2003Shun-Fen Tzeng Abstract Microglia activated after many neurological degeneration of the central nervous system (CNS) act as important regulators for neuropathogenesis in the injured CNS via producing proinflammatory mediators, such as nitric oxide (NO), TNF-,, and IL-1,. Neurotrophin-3 (NT-3) is a well-known trophic factor for neural survival, development, and plasticity. Activated microglia are NT-3-producing cells in the injured CNS, and express its receptor-TrkC. However, little is known about the effect of NT-3 on activated microglia. In this study, pre-treatment of a mouse microglial cell line, BV2, with NT-3 for 24 h indicated that NT-3 reduced the inducible form of NO synthase (iNOS), NO, and TNF-, in BV2 stimulated with lipopolysaccharide (LPS). NT-3 exerted less effect on the reduction of these proinflammatory mediators when it was added to BV2 cultures either simultaneously with LPS or post LPS treatment. These findings indicate that NT-3 may serve as an anti-inflammatory factor to suppress microglial activation. J. Cell. Biochem. 90: 227,233, 2003. © 2003 Wiley-Liss, Inc. [source] Inhibition of CCAAT/enhancer binding protein , expression by chrysin in microglial cells results in anti-inflammatory and neuroprotective effectsJOURNAL OF NEUROCHEMISTRY, Issue 2 2010Núria Gresa-Arribas J. Neurochem. (2010) 115, 526,536. Abstract The control of neuroinflammation is a potential target to be considered in the treatment of neurodegenerative diseases. It is therefore important to find anti-inflammatory drugs and study new targets that inhibit neuroinflammation. We designed an experimental model of neuroinflammation in vitro to study the anti-inflammatory and neuroprotective effects of the flavonoid chrysin and the involvement of nuclear factor-,B p65 and CCAAT/enhancer binding proteins (C/EBPs) , and , transcription factors in its mechanism of action. We used primary cultures of mouse embryonic cortical neurons and cultures of BV2 (murine microglial cell line) or mouse primary microglia. We induced neuronal death in neuronal-BV2/microglial co-cultures using lipopolysaccharide of Escherichia coli and interferon-,. Chrysin pre-treatment inhibited nitric oxide and tumor necrosis factor-, production, as well as inducible nitric oxide synthase expression in lipopolysaccharide E. coli and interferon-,-treated microglial cells, but did not affect cyclooxygenase-2 expression. Chrysin pre-treatment also protected neurons against the neurotoxicity induced by reactive microglial cells. These effects were associated to a decrease in C/EBP, protein level, mRNA expression, and DNA-binding activity, with no effect on C/EBP, and p65 nuclear protein levels or DNA-binding activity, pointing out C/EBP, as a possible mediator of chrysin effects. Consequently, C/EBP, is a possible target to act against neuroinflammation in neurodegenerative processes. [source] Delta2 -Specific Opioid Receptor Agonist and Hibernating Woodchuck Plasma Fraction Provide Ischemic NeuroprotectionACADEMIC EMERGENCY MEDICINE, Issue 3 2008Meera Govindaswami PhD Abstract Objectives:, The authors present evidence that the , opioid receptor agonist Deltorphin-Dvariant (Delt-Dvar) and hibernating woodchuck plasma (HWP), but not summer-active woodchuck plasma (SAWP), can provide significant neuroprotection from focal ischemia in mice by a mechanism that relies in part on reducing nitric oxide (NO) release in ischemic tissue. Methods:, Cerebral ischemia was produced in wild-type and NO synthase,deficient (NOS,/,) mice by transient, 1-hour middle cerebral artery occlusion (MCAO). Behavioral deficits were determined at 22 hours and infarct volume was assessed at 24 hours after MCAO. Mice were treated with saline or Delt-Dvar at 2.0 and 4.0 mg/kg, or 200 ,L of HWP or SAWP. NOS,/, mice were treated with either saline or Delt-Dvar at 4.0 mg/kg. NO release was determined using an N9 microglial cell line pretreated with ,- or ,-specific opioids and HWP or SAWP prior to activation with lipopolysaccharide and interferon-,. Nitrate in the medium was measured as an indicator of NO production. Results:, Infusion of Delt-Dvar or HWP (but not SAWP) decreased infarct volume and improved behavioral deficits following 1 hour of MCAO and 24 hours of reperfusion. In NOS,/, mice, endothelial NOS+/+ is required to provide Delt-Dvar,induced neuroprotection. Delt-Dvar and HWP dose-dependently decreased NO release in cell culture, while SAWP and other ,- and ,-specific opioids did not. Conclusions:, Delt-Dvar and HWP, but not SAWP, are effective neuroprotectant agents in a mouse model of transient MCAO. In cell culture, the mechanism of this ischemic neuroprotection may rely in part on their ability to block NO release. [source] | ||||||||||