170 research outputs found
Fifteen-S-hydroxyeicosatetraenoic acid (15-S-HETE) specifically antagonizes the chemotactic action and glomerular synthesis of leukotriene B4 in the rat
Fifteen-S-hydroxyeicosatetraenoic acid (15-S-HETE) specifically antagonizes the chemotactic action and glomerular synthesis of leukotriene B4 in the rat. In models of experimental glomerulonephritis, there is temporal concordance between the shift in the glomerular cellular infiltrate from neutrophils (PMN) to macrophages/monocytes and the suppression of glomerular leukotriene B4 (LTB4) generation. Since macrophages are a rich source of 15-lipoxygenase (15-LO) products, we investigated whether the principal product of arachidonate 15-lipoxy-genation, 15-S-hydroxyeicosatetraenoic acid (15-S-HETE), was capable of antagonizing the proinflammatory actions of LTB4 in the rat. PMN exhibited chemotaxis to LTB4 in a dose dependent manner with an LC50 of 10-8 M. When rat neutrophils were pre-treated with 15-S-HETE, chemotaxis to LTB4 was inhibited in a dose dependent manner (maximal at 30 µM 15-S-HETE) but, the same concentration did not inhibit chemotaxis to n-formyl-1-methionyl-1-phenylalanine (FMP). 12-S-HETE (30µM) did not inhibit chemotaxis to LTB4. Glomeruli from rats injected with nephrotoxic serum three hours earlier generated increased levels of LTB4; prior exposure of such glomeruli to 15-S-HETE totally normalized LTB4 production. The glomerular production of 15-S-HETE and LTB4 was also determined 3 hours, 72 hours and 2 weeks after administration of nephrotoxic serum. Whereas there was an early, short-lived, burst of LTB4 followed by a return to baseline levels, the production of 15-S-HETE increased steadily over the two week period and was present in amounts fivefold greater than LTB4. Thus, these studies assign a role for locally generated 15-LO derivatives in arresting LTB4-promoted PMN infiltration and suppressing LTB4 synthesis. Coupled with our previous demonstration of counterregula-tory interactions between lipoxins and cysteinyl leukotrienes, the current studies provide further support for a generalized anti-inflammatory role for 15-LO products through specific antagonism and/or inhibition of leukotriene synthesis and biologic activities
Pennsylvania Folklife Vol. 42, No. 2
• Charles E. Starry, Adams County Chair Maker • Lewis Miller\u27s Chronicle of York: A Picture of Life in Early America • Family Anecdotes from a Georges Creek Home • The Pennsylvania-German Schrank • The Barns of Towamensing Township • A Review of Robert F. Ensminger\u27s The Pennsylvania Barnhttps://digitalcommons.ursinus.edu/pafolklifemag/1136/thumbnail.jp
Protective Effect of the Fruit Hull of Gleditsia sinensis on LPS-Induced Acute Lung Injury Is Associated with Nrf2 Activation
The fruit hull of Gleditsia sinensis (FGS) has been prescribed as a traditional eastern Asian medicinal remedy for the treatment of various respiratory diseases, but the efficacy and underlying mechanisms remain poorly characterized. Here, we explored a potential usage of FGS for the treatment of acute lung injury (ALI), a highly fatal inflammatory lung disease that urgently needs effective therapeutics, and investigated a mechanism for the anti-inflammatory activity of FGS. Pretreatment of C57BL/6 mice with FGS significantly attenuated LPS-induced neutrophilic lung inflammation compared to sham-treated, inflamed mice. Reporter assays, semiquantitative RT-PCR, and Western blot analyses show that while not affecting NF-κB, FGS activated Nrf2 and expressed Nrf2-regulated genes including GCLC, NQO-1, and HO-1 in RAW 264.7 cells. Furthermore, pretreatment of mice with FGS enhanced the expression of GCLC and HO-1 but suppressed that of proinflammatory cytokines in including TNF-α and IL-1β in the inflamed lungs. These results suggest that FGS effectively suppresses neutrophilic lung inflammation, which can be associated with, at least in part, FGS-activating anti-inflammatory factor Nrf2. Our results suggest that FGS can be developed as a therapeutic option for the treatment of ALI
NADPH Oxidase Limits Innate Immune Responses in the Lungs in Mice
Background: Chronic granulomatous disease (CGD), an inherited disorder of the NADPH oxidase in which phagocytes are defective in generating superoxide anion and downstream reactive oxidant intermediates (ROIs), is characterized by recurrent bacterial and fungal infections and by excessive inflammation (e.g., inflammatory bowel disease). The mechanisms by which NADPH oxidase regulates inflammation are not well understood. Methodology/Principal Findings: We found that NADPH oxidase restrains inflammation by modulating redox-sensitive innate immune pathways. When challenged with either intratracheal zymosan or LPS, NADPH oxidase-deficient p47phox-/- mice and gp91phox-deficient mice developed exaggerated and progressive lung inflammation, augmented NF-kB activation, and elevated downstream pro-inflammatory cytokines (TNF-α, IL-17, and G-CSF) compared to wildtype mice. Replacement of functional NADPH oxidase in bone marrow-derived cells restored the normal lung inflammatory response. Studies in vivo and in isolated macrophages demonstrated that in the absence of functional NADPH oxidase, zymosan failed to activate Nrf2, a key redox-sensitive anti-inflammatory regulator. The triterpenoid, CDDO-Im, activated Nrf2 independently of NADPH oxidase and reduced zymosan-induced lung inflammation in CGD mice. Consistent with these findings, zymosan-treated peripheral blood mononuclear cells from X-linked CGD patients showed impaired Nrf2 activity and increased NF-kB activation. Conclusions/Significance: These studies support a model in which NADPH oxidase-dependent, redox-mediated signaling is critical for termination of lung inflammation and suggest new potential therapeutic targets for CGD
Targeting ETosis by miR-155 inhibition mitigates mixed granulocytic asthmatic lung inflammation
Asthma is phenotypically heterogeneous with several distinctive pathological mechanistic pathways. Previous studies indicate that neutrophilic asthma has a poor response to standard asthma treatments comprising inhaled corticosteroids. Therefore, it is important to identify critical factors that contribute to increased numbers of neutrophils in asthma patients whose symptoms are poorly controlled by conventional therapy. Leukocytes release chromatin fibers, referred to as extracellular traps (ETs) consisting of double-stranded (ds) DNA, histones, and granule contents. Excessive components of ETs contribute to the pathophysiology of asthma; however, it is unclear how ETs drive asthma phenotypes and whether they could be a potential therapeutic target. We employed a mouse model of severe asthma that recapitulates the intricate immune responses of neutrophilic and eosinophilic airway inflammation identified in patients with severe asthma. We used both a pharmacologic approach using miR-155 inhibitor-laden exosomes and genetic approaches using miR-155 knockout mice. Our data show that ETs are present in the bronchoalveolar lavage fluid of patients with mild asthma subjected to experimental subsegmental bronchoprovocation to an allergen and a severe asthma mouse model, which resembles the complex immune responses identified in severe human asthma. Furthermore, we show that miR-155 contributes to the extracellular release of dsDNA, which exacerbates allergic lung inflammation, and the inhibition of miR-155 results in therapeutic benefit in severe asthma mice. Our findings show that targeting dsDNA release represents an attractive therapeutic target for mitigating neutrophilic asthma phenotype, which is clinically refractory to standard care
Investigation of the Role of Arg301 Identified in the X-ray Structure of Phosphite Dehydrogenase
Copper Transport Protein Antioxidant-1 Promotes Inflammatory Neovascularization via Chaperone and Transcription Factor Function
Supplementary information accompanies this paper at http://www.nature.com/srepCopper (Cu), an essential micronutrient, plays a fundamental role in inflammation and angiogenesis; however, its precise mechanism remains undefined. Here we uncover a novel role of Cu transport protein Antioxidant-1 (Atox1), which is originally appreciated as a Cu chaperone and recently discovered as a Cu-dependent transcription factor, in inflammatory neovascularization. Atox1 expression is upregulated in patients and mice with critical limb ischemia. Atox1-deficient mice show impaired limb perfusion recovery with reduced arteriogenesis, angiogenesis, and recruitment of inflammatory cells. In vivo intravital microscopy, bone marrow reconstitution, and Atox1 gene transfer in Atox1(-/-) mice show that Atox1 in endothelial cells (ECs) is essential for neovascularization and recruitment of inflammatory cells which release VEGF and TNFα. Mechanistically, Atox1-depleted ECs demonstrate that Cu chaperone function of Atox1 mediated through Cu transporter ATP7A is required for VEGF-induced angiogenesis via activation of Cu enzyme lysyl oxidase. Moreover, Atox1 functions as a Cu-dependent transcription factor for NADPH oxidase organizer p47phox, thereby increasing ROS-NFκB-VCAM-1/ICAM-1 expression and monocyte adhesion in ECs inflamed with TNFα in an ATP7A-independent manner. These findings demonstrate a novel linkage between Atox1 and NADPH oxidase involved in inflammatory neovascularization and suggest Atox1 as a potential therapeutic target for treatment of ischemic disease.SS is a British Heart Foundation (BHF) PhD student; GDA is BHF Chair in cardiac surgery and NIHR Senior Investigator; CE is a BHF Senior Research Fellow. Sources of Funding: This research was supported by NIH R01 HL070187 (T.F.), Department of Veterans Affairs Merit Review grant 1I01BX001232 (T.F.), R01HL116976 (T.F., M.U.-F.), NIH R01 HL077524 and HL077524-S1, R21HL112293 (to M.U.-F.), Ruth L. Kirschstein-National Service Research Award (Kirschstein-NRSA) T32 Training Grant (to G-F.C.), AHA Post-doctoral Fellowship 09POST2250151 (to N.U.), and 11POST5740006 (to V.S.).Peer-reviewedPublisher Versio
The Protein Maker: an automated system for high-throughput parallel purification
The Protein Maker instrument addresses a critical bottleneck in structural genomics by allowing automated purification and buffer testing of multiple protein targets in parallel with a single instrument. Here, the use of this instrument to (i) purify multiple influenza-virus proteins in parallel for crystallization trials and (ii) identify optimal lysis-buffer conditions prior to large-scale protein purification is described
A new look at an old virus: patterns of mutation accumulation in the human H1N1 influenza virus since 1918
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