Distribution by Scientific Domains
Distribution within Medical Sciences

Kinds of KC

  • human kc

  • Selected Abstracts

    Nephritogenic Anti-DNA antibodies regulate gene expression in MRL/lpr mouse glomerular mesangial cells

    ARTHRITIS & RHEUMATISM, Issue 7 2006
    Xiaoping Qing
    Objective Lupus-associated IgG anti,double-stranded DNA antibodies are thought to be pathogenic in the kidney due to cross-reaction with glomerular antigens, leading subsequently to immune complex formation in situ and complement activation. We undertook this study to determine if pathogenic anti-DNA antibodies may also contribute to renal damage by directly influencing mesangial gene expression. Methods Complementary DNA microarray gene profiling was performed in primary mesangial cells (derived from lupus-prone MRL/lpr mice) treated with pathogenic, noncomplexed anti-DNA antibodies. Significant gene up-regulation induced by anti-DNA antibodies as determined by microarray analysis was further investigated by real-time polymerase chain reaction and methods to detect the relevant proteins. Induction of proinflammatory genes by pathogenic antibodies was confirmed by comparing gene expression in glomeruli of old versus young MRL/lpr mice, and by antibody injection in vivo. Results Pathogenic, but not nonpathogenic, antibodies significantly induced a number of transcripts, including CXCL1/KC, LCN2, iNOS, CX3CL1/fractalkine, SERPINA3G, and I,B, ("marker genes"). Blocking of Fc, receptors or using Fc, chain,knockout mesangial cells had no effect on the gene regulation effect of the pathogenic antibody R4A, indicating a non,Fc-dependent mechanism. The glomerular expression of these marker genes increased over time with the development of glomerular antibody deposition and active nephritis in MRL/lpr mice. Moreover, injection of R4A into SCID mice in vivo significantly up-regulated glomerular marker gene expression. Conclusion These findings indicate that the renal pathogenicity of anti-DNA antibodies may be attributed in part to their ability to directly modulate gene expression in kidney mesangial cells through both Fc-dependent and non,Fc-dependent mechanisms. [source]

    Sample bias from different recruitment strategies in a randomised controlled trial for alcohol dependence

    Abstract Introduction and Aims. Participants may be recruited from diverse sources for randomised controlled trials (RCT) of treatments for alcohol dependence. A mixed recruitment strategy might facilitate recruitment and increase generalisability at the expense of introducing systematic selection bias. The current study aims to compare the effects of recruitment method on socio-demographics, baseline illness characteristics, treatment retention and treatment outcome measures. Design and Methods. A secondary analysis from a previous 12 week RCT of naltrexone, acamprosate and placebo for alcohol dependence was conducted. Participants (n = 169) were obtained via four channels of recruitment including in-patient and outpatient referral, live media and print media solicitation. Baseline parameters, retention in treatment and treatment outcomes were compared in these groups. Results. Relative to in-patient subjects, those recruited via live and print media had significantly lower scores on taking steps, less in-patient rehabilitation admissions and less previous abstinence before entering the trial. Subjects recruited via print media had significantly lower scores of alcohol dependence relative to all other modes recruitment. There were no differences between recruitment strategies on treatment retention or compliance. At outcome, no significant effect of recruitment method was detected. Discussion and Conclusions. These results suggest that different recruitment methods may be sourcing subjects with different baseline characteristics of illness. Nonetheless, these differences did not significantly impact on treatment retention or outcome, suggesting that in this population it was appropriate to recruit subjects from mixed sources.[Morley KC, Teesson M, Sannibale C, Haber PS. Sample bias from different recruitment strategies in a randomised controlled trial for alcohol dependence. Drug Alcohol Rev 2009] [source]

    Neutrophil recruitment in immunized mice depends on MIP-2 inducing the sequential release of MIP-1,, TNF-, and LTB4

    Abstract Neutrophils are thought to play an important role in the tissue damage observed in various autoimmune diseases. Chemokines, cytokines and leukotrienes have recognized roles in the orchestration of neutrophil migration. We have recently shown that antigen-induced neutrophil migration into the peritoneum of immunized mice is mediated by macrophage-inflammatory protein (MIP)-1, which interacts with CCR1 and induces the sequential release of TNF-, and leukotriene,B4 (LTB4). The present study investigates the role of MIP-2 and CXCR2 in the cascade of events leading to mediator generation and neutrophil influx. Antigen challenge of immunized mice induced the expression of CXCR2 and the production of KC and MIP-2 proteins. Antigen-induced neutrophil migration was inhibited by a CXCR2 receptor antagonist (repertaxin) or an anti-MIP-2 antibody, but not by an anti-KC antibody. Administration of MIP-2 promoted a dose-dependent neutrophil migration in naive mice which was inhibited by repertaxin, anti-TNF-,, anti-MIP-1, antibodies or by MK886 (leukotriene synthesis inhibitor). MIP-2 administration induced the release of MIP-1,, TNF-, and LTB4, and the release of the latter two was inhibited by anti-MIP-1, antibody treatment. Our studies highlight the intricate balance between mediator production and action during an immune-mediated inflammatory response and suggest a mediator cascade leading to neutrophil influx following antigen challenge of immunized mice: MIP-2 , MIP-1, , TNF-, , LTB4. [source]

    CCL17 transgenic mice show an enhanced Th2-type response to both allergic and non-allergic stimuli

    Yuichiro Tsunemi Dr.
    Abstract CC chemokine ligand (CCL)17 is implicated in the pathogenesis of atopic dermatitis (AD). To study the effect of CCL17 produced by keratinocytes (KC) during inflammation, we created transgenic (Tg) mice in which CCL17 is overexpressed in KC. Th2-type contact hypersensitivity (CHS) was enhanced and Th1-type CHS was suppressed in these mice. Increased numbers of CC chemokine receptor (CCR)4+ cells and mast cells infiltrated in Tg mice. Levels of IL-4 mRNA were higher and those of IFN-, mRNA were lower in both acute and chronic CHS. Higher levels of serum IgE were observed after CHS. Numbers of CCR4+ cells among PBMC were increased in Tg mice challenged acutely on the trunk. Chronic irritation with croton oil induced dermatitis and an elevation of serum IgE levels. Tg mice showed enhanced ear swelling after tape stripping. CCL17 was thought to modify the inflammation caused by sensitizing reagents as well as irritant reagents by attracting CCR4+ cells into the lesional skin and creating a Th2-dominant condition. AD-like conditions such as increased number of mast cells and elevated levels of serum IgE were observed. Thus, CCL17 may participate in the pathogenesis of skin diseases such as AD by regulating both allergic and irritant inflammation. [source]

    The immune status of Kupffer cells profoundly influences their responses to infectious Plasmodium berghei sporozoites

    Nick Steers
    Abstract Multi-factorial immune mechanisms underlie protection induced with radiation-attenuated Plasmodia sporozoites (,-spz). Spz pass through Kupffer cells (KC) before invading hepatocytes but the involvement of KC in protection is poorly understood. In this study we investigated whether ,-spz-immune KC respond to infectious spz in a manner that is distinct from the response of naive KC to infectious spz. KC were isolated from (1) naive, (2) spz-infected, (3) ,-spz-immune, and (4) ,-spz-immune-challenged C57BL/6 mice and examined for the expression of MHC class I and II, CD40 and CD80/CD86, IL-10 and IL-12 responses and antigen-presenting cell (APC) function. KC from ,-spz-immune-challenged mice up-regulated class I and costimulatory molecules and produced elevated IL-12p40, relative to naive KC. In contrast, KC from naive mice exposed to infectious spz down-modulated class I and IL-12p40 was undetectable. Accordingly, KC from spz-infected mice had reduced APC function, while KC from ,-spz-immune-challenged mice exhibited augmented APC activity. The nearly opposite responses are consistent with the fact that spz challenge of ,-spz-immune mice results in long-lasting sterile protection, while infection of naive mice always results in malaria. [source]

    C5a anaphylatoxin as a product of complement activation up-regulates the complement inhibitory factor H in rat Kupffer cells

    Gerald Schlaf
    Abstract The 155-kDa complement regulator factor H (FH) is the predominant soluble regulatory protein of the complement system. It acts as a cofactor for the factor I-mediated conversion of the component C3b to iC3b, competes with factor B for a binding site on C3b and C3(H2O) and promotes the dissociation of the C3bBb complex. The primary site of synthesis is the liver, i.e. FH-specific mRNA and protein were identified in both hepatocytes (HC) and Kupffer cells (KC). Previous studies in rat primary HC and KC had shown that the proinflammatory cytokine IFN-, influences the balance between activation and inhibition of the complement system through up-regulation of the inhibitory FH. In this study we show that C5a, as a product of complement activation, stimulates the expression of FH-specific mRNA and protein in KC and thus induces a negative feedback. Quantitative-competitive RT-PCR showed an approximate threefold C5a-induced up-regulation of FH. ELISA analyses revealed a corresponding increase in FH protein in the supernatants of KC. The up-regulation of FH was completely inhibited by the C5a-blocking monoclonal antibody 6-9F. Furthermore, an involvement of LPS and IFN-, was excluded, which strongly indicates a direct effect of C5a on the expression of FH in KC. [source]

    Differential role of IL-18 and IL-12 in the host defense against disseminated Candida albicans infection

    Abstract IFN-, plays a crucial role in the defense against infection with Candida albicans. Since IL-18 and IL-12 are strong stimuli of IFN-, production, we investigated whether endogenous IL-18 and IL-12 are involved in the host defense during disseminated candidiasis. IL-18 knockout (IL-18-/-) mice, but not IL-12-/- mice, displayed an increased mortality due to C. albicans infection, accompanied by a decreased clearance of the yeasts from the kidneys late during the course of infection. Histopathology of the organs, combined with phagocyte recruitment experiments, showed a decreased influx of monocytes at the sites of Candida infection, mainly in the IL-18-/- mice. Whereas production of the chemokine KC was decreased in both IL-18-/- and IL-12-/- mice, MIP-2 production was deficient only in IL-18-/- animals, which may explain the differences in phagocyte recruitment. In addition, although IFN-, production capacity, as a parameter of the Th1-protective immunity, was reduced by 65 to 80% in the IL-12-/- mice, this defect was even more pronounced in the IL-18-/- mice (85 to 95% downmodulation). In conclusion, the anticandidal effects of endogenous IL-18 are mediated late during the infection by assuring a proper IFN-, response and promoting the infiltration of the site of infection by monocytes. [source]

    Interferon-, differentially modulates the release of cytokines and chemokines in lipopolysaccharide- and pneumococcal cell wall-stimulated mouse microglia and macrophages

    Karl Georg Häusler
    Abstract During bacterial infections of the CNS, activated microglia could support leucocyte recruitment to the brain through the synthesis of cyto- and chemokines. In turn, invading leucocytes may feedback on microglial cells to influence their chemokine release pattern. Here, we analyzed the capacity of interferon-, (IFN,) to serve as such a leucocyte-to-microglia signal. Production of cyto- and chemokines was stimulated in mouse microglia cultures by treatments with lipopolysaccharide (LPS) from Gram-negative Escherichia coli or cell walls from Gram-positive Streptococcus pneumoniae (PCW). IFN, presence during the stimulation (0.1,100 ng/mL) modulated the patterns of LPS- and PCW-induced cyto- and chemokine release in a dose-dependent, potent and complex manner. While amounts of TNF, and IL-6 remained nearly unchanged, IFN, enhanced the production of IL-12, MCP-1 and RANTES, but attenuated that of KC, MIP-1, and MIP-2. Release modulation was obtained with IFN, preincubation (treatment of cells before LPS or PCW administration), coincubation and even delayed addition to an ongoing LPS or PCW stimulation. Together the changes observed for the microglial chemokine release under IFN, would shift the chemoattractive profile from favouring neutrophils to a preferential attraction of monocytes and T lymphocyte populations , as actually seen during the course of bacterial meningitis. The findings support the view of activated microglia as a major intrinsic source for an instant production of a variety of chemokines and suggest that leucocyte-derived IFN, could potentially regulate the microglial chemokine release pattern. [source]

    The skin as a biofactory for systemic secretion of erythropoietin: potential of genetically modified keratinocytes and fibroblasts

    Frank Scheidemann
    Abstract Background:, The skin is an interesting target tissue for gene therapy applications because of its ready accessibility. One possibility would be to utilize the genetically modified skin as a biofactory secreting a systemically needed product, such as erythropoietin (EPO). Methods:, Keratinocytes (KC) and fibroblasts (FB) were transduced with a retroviral vector encoding human EPO. Gene transfer efficiency was assessed by real-time PCR analysis and flow cytometry of transduced cells. In addition, EPO synthesis and secretion were analysed by quantifying the amount of RNA and secreted protein in both monolayer cultures and skin equivalents (SE). Results:, When cultured as a monolayer, EPO-KC synthesized significantly more EPO than EPO-FB, as shown by quantitatively measuring the amount of secreted protein and RNA. This correlated with an increased EPO-vector incorporation in KC compared with FB, demonstrated by determining both the percentage of transduced cells and the average transgene copy number per cell. In addition, in transduced cell cultures enriched to equally high percentages of EPO+ cells, KC showed a higher activity of EPO secretion than FB. Finally, when assembled in a SE, EPO-KC secreted significantly higher amounts of EPO than EPO-FB, although reduced secretory activity of EPO-KC monolayers grown in high calcium concentrations suggested that in stratified epidermis differentiated KC secrete less EPO than non-differentiated KC. Conclusion:, In summary, while both transduced KC and FB are able to synthesize and secrete human EPO, KC show higher potential in serving as possible target cells for therapeutic substitution with EPO, probably because of improved transduction rates and increased secretory activity. [source]

    Cholinergic control of epidermal cohesion

    Sergei A. Grando
    Abstract:, The non-neuronal cholinergic system of human epidermis includes the keratinocyte (KC) acetylcholine (ACh) axis composed of the enzymes mediating ACh synthesis and degradation, and two classes of ACh receptors, the nicotinic and muscarinic ACh receptors, mediating biological effects of the cutaneous cytotransmitter ACh. Regulation of KC cell,cell and cell,matrix adhesion is one of the important biological functions of cutaneous ACh. The downstream targets of ACh effects mediated by distinct ACh receptor subtypes include both the intercellular adhesion molecules, such as classical and desmosomal cadherins, and integrins mediating KC adhesion to a substrate. The signaling pathways include activation or inhibition of kinase cascades resulting in either up- or down-regulation of the expression of cell adhesion molecules or changes in their phosphorylation status, or both. The components of the KC ACh axis are involved in cutaneous blistering in patients with autoimmune pemphigus, junctional and dystrophic forms of epidermolysis bullosa, thermal burns, and mustard-induced vesication. Recent progress with the development of antiacantholytic therapies of patients with pemphigus using cholinomimetics indicates that cholinergic drugs may be a promising approach for other cutaneous blistering disorders. [source]

    Aberrant signalling and transcription factor activation as an explanation for the defective growth control and differentiation of keratinocytes in psoriasis: a hypothesis

    R. C. McKenzie
    Abstract:, Psoriasis is a chronic inflammatory skin disease characterized by the accumulation of red, scaly plaques on the skin. The plaques result from hyperproliferation and incomplete differentiation of keratinocytes (KC) in a process that seems to be driven, in part by skin-infiltrating leucocytes. We believe that the KC have inherent defects in intracellular signalling which could be usefully targeted to allow the development of more effective therapies. We suggest that there are defects in the regulation of the transcription factors: signal transducer and activator of transcription (STAT-1,), interferon regulated factor-1 (IRF-1) and NF,B which lead to loss of growth and differentiation control when the cells are subjected to physico-chemical and immunological stress. We also highlight recent studies that suggest that peroxisome proliferator-activated receptors, the notch receptor and defects in calcium and other ion transporting proteins may contribute to impairment in the ability of psoriatic KC to differentiate. The role of these systems in the development of the psoriatic phenotype and tests of these hypotheses are proposed. [source]

    Ca2+/H+ antiporter-like activity of human recombinant Bax inhibitor-1 reconstituted into liposomes

    FEBS JOURNAL, Issue 8 2009
    Taeho Ahn
    We investigated the functional activity of recombinant Bax inhibitor-1 reconstituted into liposomes. When proteoliposomes were suspended in acidic solutions, encapsulated Ca2+ was released from the membranes, as previously suggested [Kim HR, Lee GH, Ha KC, Ahn T, Moon JY, Lee BJ, Cho SG, Kim S, Seo YR, Shin YJ et al. (2008) J Biol Chem283, 15946,15955]. Concomitantly, proton ions were internalized when assayed using the time-dependent change in the fluorescence of the pH-sensitive dye oxonol V entrapped in the proteoliposomes. The influx of proton ions was confirmed by observing tritium accumulation in the membranes. However, the external acidity of the membranes per se did not induce proton ion influx without internalized Ca2+. These results suggest that reconstituted Bax inhibitor-1 has a Ca2+/H+ antiporter-like activity. [source]

    Atrial natriuretic peptide-dependent photolabeling of a regulatory ATP-binding site on the natriuretic peptide receptor-A

    FEBS JOURNAL, Issue 21 2005
    Simon Joubert
    The natriuretic peptide receptor-A (NPR-A) is composed of an extracellular ligand-binding domain, a transmembrane-spanning domain, a kinase homology domain (KHD) and a guanylyl cyclase domain. Because the presence of ATP or adenylylimidodiphosphate reduces atrial natriuretic peptide (ANP) binding and is required for maximal guanylyl cyclase activity, a direct interaction of ATP with the receptor KHD domain is plausible. Therefore, we investigated whether ATP interacts directly with a binding site on the receptor by analyzing the binding of a photoaffinity analog of ATP to membranes from human embryonic kidney 293 cells expressing the NPR-A receptor lacking the guanylyl cyclase moiety (,GC). We demonstrate that this receptor (NPR-A-,GC) can be directly labeled by 8-azido-3,-biotinyl-ATP and that labeling is highly increased following ANP treatment. The mutant receptor ,KC, which does not contain the KHD, is not labeled. Photoaffinity labeling of the NPR-A-,GC is reduced by 50% in the presence of 550 µm ATP, and competition curve fitting studies indicate a Hill slope of 2.2, suggestive of cooperative binding. This approach demonstrates directly that the interaction of ANP with its receptor modulates the binding of ATP to the KHD, probably through a conformational change in the KHD. In turn, this conformational change is essential for maximal activity. In addition, the ATP analog, 8-azido-adenylylimidodiphosphate, inhibits guanylyl cyclase activity but increases ANP binding to the extracellular domain. These results suggest that the KHD regulates ANP binding and guanylyl cyclase activity independently. [source]

    RANTES stimulates inflammatory cascades and receptor modulation in murine astrocytes

    GLIA, Issue 1 2002
    Yi Luo
    Abstract Cultured mouse astrocytes respond to the CC chemokine RANTES by production of chemokine and cytokine transcripts. Stimulation of astrocytes with 1 nM RANTES or 3,10 nM of the structurally related chemokines (eotaxin, macrophage inflammatory protein-1, and -, [MIP-1,, MIP-1,]) induced transcripts for KC, monocyte chemoattractant protein-1 (MCP-1), tumor necrosis factor-, (TNF-,), MIP-1,, MIP-2, and RANTES in a chemokine and cell-specific fashion. Synthesis of chemokine (KC and MCP-1) and cytokine (TNF-,) proteins was also demonstrated. RANTES-mediated chemokine synthesis was specifically inhibited by pertussis toxin, indicating that G-protein-coupled chemokine receptors participated in astrocyte signaling. Astrocytes expressed CCR1 and CCR5 (the redundant RANTES receptors). Astrocytes derived from mice with targeted mutations of either CCR1 or CCR5 respond after RANTES stimulation, suggesting multiple chemokine receptors may separately mediate RANTES responsiveness in astrocytes. Preliminary data suggest activation of the MAP kinase pathway is also critical for RANTES-mediated signaling in astrocytes. Treatment with RANTES specifically modulated astrocyte receptors upregulating intercellular adhesion molecule 1 (ICAM-1) and downregulating CX3CR1 expression. Thus, after chemokine treatment, astrocytes release proinflammatory mediators and reprogram their surface molecules. The combined effects of RANTES may serve to amplify inflammatory responses within the central nervous system. GLIA 39:19,30, 2002. © 2002 Wiley-Liss, Inc. [source]

    Fluorescence Regeneration as a Signaling Principle for Choline and Carnitine Binding: A Refined Supramolecular Sensor System Based on a Fluorescent Azoalkane,

    H. Bakirci
    Abstract The fluorescent azoalkane, 2,3-diazabicyclo[2.2.2]oct-2-ene (DBO), forms inclusion complexes with p -sulfonatocalix[4]arene (CX4). The binding constants are on the order of 103,M,1 in water. The addition of CX4 to DBO solutions results in an efficient fluorescence quenching (up to 90,%). This supramolecular system can be used as a truly water-soluble sensor system to signal the binding of organic ammonium ions over a large pH range. Addition of choline and carnitine derivatives and tetraalkylammonium ions results in regeneration of this fluorescence, from which the binding constants (KC,=,103,105,M,1) are calculated by means of a competitive complexation model. Electrostatic effects are observed, namely, a more-than-one order of magnitude weaker binding of the carnitines in neutral solution. [source]

    Mechanism of T cell tolerance induction by murine hepatic Kupffer cells,

    HEPATOLOGY, Issue 3 2008
    Qiang You
    The liver is known to favor the induction of immunological tolerance rather than immunity. Although Kupffer cells (KC) have been indicated to play a role in liver tolerance to allografts and soluble antigens, the mechanisms involved remain unclear. We hypothesized that KCs could promote immune tolerance by acting as incompetent antigen-presenting cells (APC), as well as actively suppressing T cell activation induced by other potent APCs. The expression of antigen presentation-related molecules by KCs was phenotyped by flow cytometry. The abilities of KCs to act as APCs and to suppress T cell activation induced by splenic dendritic cells (DC) were examined by in vitro proliferation assays using CD4+ OVA-TCR (ovalbumin T cell receptor) transgenic T cells. We found that, compared with DCs, KCs expressed significantly lower levels of major histocompatibility complex (MHC) II, B7-1, B7-2, and CD40. This result is consistent with our observation that KCs were not as potent as DCs in eliciting OVA-specific T cell proliferation. However, KCs isolated from polyinosinic:polycytidylic acid,treated mice expressed significantly higher levels of MHC II and costimulatory molecules than did naïve KCs and could stimulate stronger T cell responses. More importantly, we found that KCs could inhibit DC-induced OVA-specific T cell activation. Further investigation of the underlying mechanism revealed that prostaglandins produced by KCs played an important role. The results ruled out the possible involvement of interleukin-10, nitric oxide, 2,3-dioxygenase, and transforming growth factor , in KC-mediated T cell suppression. Conclusion: Our data indicate that KCs are a tolerogenic APC population within the liver. These findings suggest that KCs may play a critical role in regulating immune reactions within the liver and contributing to liver-mediated systemic immune tolerance. (HEPATOLOGY 2008.) [source]

    Inflammation and drug hepatotoxicity: Aggravation of injury or clean-up mission?,

    HEPATOLOGY, Issue 5 2005
    Hartmut Jaeschke
    BACKGROUND & AIMS Inflammatory mediators released by nonparenchymal inflammatory cells in the liver have been implicated in the progression of acetaminophen (APAP) hepatotoxicity. Among hepatic nonparenchymal inflammatory cells, we examined the role of the abundant natural killer (NK) cells and NK cells with T-cell receptors (NKT cells) in APAP-induced liver injury. METHODS C57BL/6 mice were administered a toxic dose of APAP intraperitoneally to cause liver injury with or without depletion of NK and NKT cells by anti-NK1.1 monoclonal antibody (MAb). Serum alanine transaminase (ALT) levels, liver histology, hepatic leukocyte accumulation, and cytokine/chemokine expression were assessed. RESULTS Compared with APAP-treated control mice, depletion of both NK and NKT cells by anti-NK1.1 significantly protected mice from APAP-induced liver injury, as evidenced by decreased serum ALT level, improved survival of mice, decreased hepatic necrosis, inhibition of messenger RNA (mRNA) expression for interferon-gamma (IFN-gamma), Fas ligand (FasL), and chemokines including KC (Keratinocyte-derived chemokine); MIP-1 alpha (macrophage inflammatory protein-1 alpha); MCP-1 (monocyte chemoattractant protein-1); IP-10 (interferon-inducible protein); Mig (monokine induced by IFN-gamma) and decreased neutrophil accumulation in the liver. Hepatic NK and NKT cells were identified as the major source of IFN-gamma by intracellular cytokine staining. APAP induced much less liver injury in Fas-deficient (lpr) and FasL-deficient (gld) mice compared with that in wild-type mice. CONCLUSIONS NK and NKT cells play a critical role in the progression of APAP-induced liver injury by secreting IFN-gamma, modulating chemokine production and accumulation of neutrophils, and up-regulating FasL expression in the liver, all of which may promote the inflammatory response of liver innate immune system, thus contributing to the severity and progression of liver injury downstream of the metabolism of APAP and depletion of reduced glutathione (GSH) in hepatocytes. [source]

    Induction of cellular resistance against Kupffer cell,derived oxidant stress: A novel concept of hepatoprotection by ischemic preconditioning

    HEPATOLOGY, Issue 2 2003
    Rolf J. Schauer
    Ischemic preconditioning (IP) triggers protection of the liver from prolonged subsequent ischemia. However, the underlying protective mechanisms are largely unknown. We investigated whether and how IP protects the liver against reperfusion injury caused by Kupffer cell (KC)-derived oxidants. IP before 90 minutes of warm ischemia of rat livers in vivo significantly reduced serum alanine aminotransferase (AST) levels and leukocyte adherence to sinusoids and postsinusoidal venules during reperfusion. This protective effect was mimicked by postischemic intravenous infusion of glutathione (GSH), an antioxidative strategy against KC-derived H2O2. Interestingly, no additional protection was achieved by infusion of GSH to preconditioned animals. These findings and several additional experiments strongly suggest IP mediated antioxidative effects: IP prevented oxidant cell injury in isolated perfused rat livers after selective KC activation by zymosan. Moreover, IP prevented cell injury and pertubations of the intracellular GSH/GSSG redox system caused by direct infusion of H2O2 (0.5 mmol/L). IP-mediated resistance against H2O2 could neither be blocked by the adenosine A2a antagonist DMPX nor mimicked by A2a agonist CGS21680. In contrast, H2O2 resistance was abolished by the p38 mitogen-activated protein kinase (p38 MAPK) inhibitor SB203580, but induced when p38 MAPK was directly activated by anisomycin. In conclusion, we propose a novel concept of hepatoprotection by IP: protection of liver cells by enhancing their resistance against KC-derived H2O2. Activation of p38 MAPK and preservation of the intracellular GSH/oxidized glutathione (GSSG) redox system, but not adenosine A2a receptor stimulation, seems to be pivotal for the development of H2O2 resistance in preconditioned livers. [source]

    Tolerogenic dendritic cells pulsed with enterobacterial extract suppress development of colitis in the severe combined immunodeficiency transfer model

    IMMUNOLOGY, Issue 4 2007
    A. E. Pedersen
    Summary Immunomodulatory dendritic cells (DCs) that induce antigen-specific T-cell tolerance upon in vivo adoptive transfer are promising candidates for immunotherapy of autoimmune diseases. The feasibility of such a strategy has recently proved its efficacy in animal models of allotransplantation and experimental allergic encephalitis, but the effect in inflammatory bowel disease has not yet been demonstrated. In severe combined immunodeficient (SCID) mice, adoptively transferred CD4+ CD25, T cells repopulate the lymphoid tissues and lead to development of chronic colitis characterized by CD4+ T-cell proliferation against enterobacterial extract in vitro. In this model, we adoptively transferred in-vitro -generated bone-marrow-derived DCs exposed to interleukin-10 (IL-10) and an enterobacterial extract. We show that these cells are CD11c positive with intermediate expression of CD40, CD80 and CD86 and have a diminished secretion of IL-6, IL-12 p40/70, tumour necrosis factor-, and keratinocyte-derived chemokine (KC) compared to DCs treated with enterobacterial extract alone. In vivo, these cells prevented weight loss in SCID mice adoptively transferred with CD4+ CD25, T cells, resulted in a lower histopathology colitis score and tended to result in higher serum levels of IL-1,, IL-10, IL-12, IL-13, IL-17, KC and monokine induced by interferon-gamma (MIG). These data underscore the potential of using immunomodulatory DCs to control inflammatory bowel disease and demonstrate its potential use in future human therapeutic settings. [source]

    Fas ligand-induced murine pulmonary inflammation is reduced by a stable decoy receptor 3 analogue

    IMMUNOLOGY, Issue 2 2003
    Mark A. Wortinger
    Summary Fas ligand (FasL)-induced lung inflammation has recently been suggested to play an important role in the pathogenesis of acute respiratory disease syndrome (ARDS). In order to further explore this connection, we established a FasL-induced murine model of pulmonary inflammation. Instillation of recombinant FasL (rFasL) into the lung induced neutrophil infiltration and increased pulmonary permeability, as evidenced by increased total protein in the airspace; both occur in patients with ARDS. These effects were accompanied with a rapid induction of proinflammatory mediators: cytokine granulocyte,macrophage colony-stimulating factor (GM-CSF) and the chemokines macrophage inflammatory protein-2 (MIP-2) and KC. Pretreatment with a FasL antagonist, a decoy receptor 3 analogue (DcR3 analogue), reduced neutrophil infiltration into the airspace and resulted in a highly significant reduction in the levels of GM-CSF, MIP-2 and KC in bronchoalveolar lavage (BAL) fluid. We postulate that rFasL may be responsible for induction of proinflammatory chemokines and cytokines in the lung, which in turn attract neutrophil infiltration into the airspace. This proinflammatory process and the associated pulmonary permeability may, in part, explain the association of FasL with severe pulmonary inflammation, such as ARDS, and shed new light on FasL and its role in lung injury. [source]

    Toll-like receptor and tumour necrosis factor dependent endotoxin-induced acute lung injury

    Dieudonnée Togbe
    Summary Recent studies on endotoxin/lipopolysaccharide (LPS)-induced acute inflammatory response in the lung are reviewed. The acute airway inflammatory response to inhaled endotoxin is mediated through Toll-like receptor 4 (TLR4) and CD14 signalling as mice deficient for TLR4 or CD14 are unresponsive to endotoxin. Acute bronchoconstriction, tumour necrosis factor (TNF), interleukin (IL)-12 and keratinocyte-derived chemokine (KC) production, protein leak and neutrophil recruitment in the lung are abrogated in mice deficient for the adaptor molecules myeloid differentiation factor 88 (MyD88) and Toll/Interleukin-1 receptor (TIR)-domain-containing adaptor protein (TIRAP), but independent of TIR-domain-containing adaptor-inducing interferon-beta (TRIF). In particular, LPS-induced TNF is required for bronchoconstriction, but dispensable for inflammatory cell recruitment. Lipopolysaccharide induces activation of the p38 mitogen-activated protein kinase (MAPK). Inhibition of pulmonary MAPK activity abrogates LPS-induced TNF production, bronchoconstriction, neutrophil recruitment into the lungs and broncho-alveolar space. In conclusion, TLR4-mediated, bronchoconstriction and acute inflammatory lung pathology to inhaled endotoxin are dependent on TLR4/CD14/MD2 expression using the adapter proteins TIRAP and MyD88, while TRIF, IL-1R1 or IL-18R signalling pathways are dispensable. Further downstream in this axis of signalling, TNF blockade reduces only acute bronchoconstriction, while MAPK inhibition abrogates completely endotoxin-induced inflammation. [source]

    New media for the semiselective isolation and enumeration of Xanthomonas campestris pv. mangiferaeindicae, the causal agent of mango bacterial black spot

    O. Pruvost
    Abstract Aims:, Mango bacterial black spot, caused by Xanthomonas campestris pv. mangiferaeindicae, is a potentially severe disease in several tropical and subtropical areas. Data describing the life cycle of the pathogen are needed for improving integrated pest management strategies. Because of the important bacterial microflora associated with mango leaves, isolation of the pathogen is often difficult using nonselective agar media. Methods and Results:, A previously developed medium, BVGA, failed to inhibit several Gram-negative saprophytic bacteria, especially those belonging to Enterobacteriaceae. Two new semiselective media were developed. The selectivity of KC and NCTM3 media was achieved using cephalexin 40 mg l,1, kasugamycin 20 mg l,1 and neomycin 1 mg l,1, cephalexin 100 mg l,1, trimethoprime 5 mg l,1, pivmecillinam 100 mg l,1 respectively. Plating efficiencies ranged from 76 to 104% and from 78 to 132% for KC and NCTM3 respectively. Conclusions:, The new media allowed the growth of X. campestris pv. mangiferaeindicae whatever its country of isolation. The pathogen was repeatedly isolated with these media from asymptomatic leaves sampled in growth chamber experiments. Significance and Impact of the Study:, This work provides a description of new semiselective media, which should be valuable tools to study the ecology and epidemiology of X. campestris pv. mangiferaeindicae. [source]

    Kinetics of methyl methacrylate grafting polymerization onto flaky aluminum powder

    Hui Liu
    Abstract With ammonium persulfate (APS) as the initiator, the kinetics of methyl methacrylate (MMA) grafting polymerization onto flaky aluminum powder (Al) was studied. It was found that the experimental apparent grafting polymerization rate, Rg = KC × C × C, was basically consistent with the theoretical result based on the theory of stable polymerization and equivalent activity, Rg = KC × C × CMMA. The activation energy of grafting, homogenous, and total polymerization rate was calculated as 65.1, 35.4, and 37.5 kJ mol,1, respectively. It could be validated that the relationship among these activation energies accorded with the theoretical result of parallel reactions. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source]

    Studies on the cell treatment conditions to elicit lipolytic responses from 3T3-L1 adipocytes to TCDD, 2,3,7,8-tetrachlorodibenzo-p-dioxin

    Wen Li
    Abstract Wasting syndrome is one of the hallmark symptoms of poisoning by TCDD (=dioxin), which is associated with the massive loss of adipose tissue and serum hyperlipidemia in vivo. Yet, the most widely used in vitro cell model 3T3-L1 adipocyte has not been useful for studying such an action of TCDD because of the difficulty of inducing their mature adipocytes to respond to TCDD to go through lipolysis. Here, we made efforts to find the right cell culture and treatment conditions to induce mature 3T3-L1 adipocytes to go through lipolysis, which is defined as events leading to reduction of lipids in adipocytes. The optimum condition was found to require 7-day differentiated adipocytes being subjected to DMEM medium containing TCDD (but without insulin) for 5 day incubation with two medium changes (the same composition) on incubation days 2 and 4. After 24 h, the early effect of TCDD on adipocytes was predominantly on inflammation, particularly induction of COX-2 and KC (IL-8), which is accompanied by upregulation of C/EBP, and ,. The sign of TCDD-induced lipolysis starts slowly and by incubation day 3, a few markers showed modestly significant changes. By day 5 of incubation, however, many markers show highly significant signs of lipolytic changes. Although this process could take place without exogenous macrophages or their cytokines, addition of exogenous TNF, considerably synergized this action of TCDD. In conclusion, under a right condition, 3T3-L1 adipocytes were found to respond to TCDD to go through lipolysis. The early trigger of such a response appears to be activation of COX-2, which is amplified by TNF,. J. Cell. Biochem. 102: 389,402, 2007. © 2007 Wiley-Liss, Inc. [source]

    Hedgehog signaling maintains hair follicle stem cell phenotype in young and aged human skin

    AGING CELL, Issue 6 2009
    Laure Rittié
    Summary Skin hair follicles (HF) contain bulge stem cells (SC) that regenerate HFs during hair cycles, and repair skin epithelia following injury. As natural aging is associated with decreased skin repair capacity in humans, we have investigated the impact of age on human scalp HF bulge cell number and function. Here, we isolated human bulge cells, characterized as CD200+/KRT15+/KRT19+ cells of the HF, by dissection-combined CD200 selection in young and aged human skin. Targeted transcriptional profiling indicates that KRT15, KRT19, Dkk3, Dkk4, Tcf3, S100A4, Gas1, EGFR and CTGF/CCN2 are also preferentially expressed by human bulge cells, compared to differentiated HF keratinocytes (KC). Our results demonstrate that aging does not alter expression or localization of these HF SC markers. In addition, we could not detect significant differences in HF density or bulge cell number between young and aged human scalp skin. Interestingly, hedgehog (Hh) signaling is activated in human bulge cells in vivo, and down-regulated in differentiated HF KCs, both in young and aged skin. In addition, activation of Hh signaling by lentivirus-mediated overexpression of transcription factor Gli1 induces transcription of HF SC markers KRT15, KRT19, and Gas1, in cultured KCs. Together with previously reported knock-out mouse results, these data suggest a role for Hh signaling in maintaining bulge cell phenotype in young and aged human skin. [source]

    Safe Criteria and Procedure for Kangaroo Care With Intubated Preterm Infants

    FAAN professor, Susan M. Ludington-Hoe CNM
    Kangaroo care (KC) was safely conducted with mechanically ventilated infants who weighed less than 600 grams and were less than 26 weeks gestation at birth. These infants, ventilated for at least 24 hours at the time of the first KC session, were considered stable on the ventilator at low settings (intermittent mandatory ventilation < 35 breaths per minute and FiO2 < 50%), had stable vital signs, and were not on vasopressors. A protocol for implementation of KC with ventilated infants that uses a standing transfer, with two staff members assisting to minimize the possibility of extubation, is presented. Also discussed is the positioning of the ventilator tubing during KC. This protocol was implemented without any accidental extubation throughout an experimental research study. The criteria and protocol were compared to those available in published reports and revealed many similar elements, providing additional support for the recommended protocol. No adverse events occurred with the criteria and protocol reported here, suggesting that they can be adopted for broader use. [source]

    Decreased Pulmonary Inflammation Following Ethanol and Burn Injury in Mice Deficient in TLR4 but not TLR2 Signaling

    ALCOHOLISM, Issue 10 2010
    Melanie D. Bird
    Background:, Clinical and laboratory evidence suggests that alcohol consumption prior to burn injury leads to dysregulated immune function and subsequent higher rates of morbidity and mortality. Our laboratory previously observed higher levels of pro-inflammatory cytokines and leukocyte infiltration in the lungs of mice following ethanol and burn injury. To understand the mechanism of the increased inflammatory response, we looked at different signaling initiators of inflammation including toll-like receptors 2 and 4 (TLR2 and 4) pathways. Methods:, Wild-type, TLR2, and TLR4 knockout mice were treated with vehicle or a single binge dose of ethanol (1.11 g/kg) and subsequently given a sham or burn injury. Twenty-four hours postinjury, systemic and pulmonary levels of pro-inflammatory cytokines were quantified, and differences in neutrophil infiltration were determined by histological examination. Results:, Higher numbers of neutrophils were observed in the lungs of wild-type mice following the combined insult of ethanol and burn injury relative to either injury alone. This increase in leukocyte accumulation was absent in the TLR4 knockout mice. Circulating levels of IL-6 and tumor necrosis factor-, were also elevated in wild-type mice but not in TLR4 knockout mice. Consistent with these findings, pulmonary levels of KC and IL-6 were increased in wild-type mice following burn and ethanol compared to burn injury alone as well as to their TLR4 knockout counterparts. In contrast, TLR2 knockout mice displayed similar levels, to wild-type mice, of neutrophil infiltration as well as IL-6 and KC in the lung. Conclusions:, These data suggest that TLR4 signaling is a crucial contributory component in the exuberant inflammation after ethanol and burn injury. However, TLR2 does not appear to play a vital role in the aberrant pulmonary inflammation. [source]

    The anti-inflammatory modulatory role of Solidago chilensis Meyen in the murine model of the air pouch

    Rafael Liz
    The aim of this study was to investigate the anti-inflammatory efficacy of an aqueous extract (AE), and its butanolic (BuOH) and aqueous residual (AR) fractions, derived from the rhizome of Solidago chilensis in inflammation caused by carrageenan in mice. Solidago chilensis Meyen rhizome was extracted using hot water at 90°C under infusion. The extract was filtered and lyophilized. Part of the aqueous extract was fractionated with n-BuOH, resulting in butanolic (BuOH) and aqueous residual (AR) fractions. Adult Swiss mice were used in the in-vivo experiments. We evaluated the effect of rhizome aqueous extract of Solidago chilensis and these two derived fractions on the inflammation induced by carrageenan in the mouse model of the air pouch. The aqueous extract and its derived fractions significantly inhibited leucocytes, neutrophils, exudation, myeloperoxidase and adenosine deaminase activity, as well as nitric oxide, interleukin-1 beta (IL-1,), neutrophil chemokine (KC) and tumour necrosis factor-alpha (TNF-,) levels (P < 0.05). Indometacin and dexamethasone inhibited all the studied inflammatory parameters (P < 0.01) with the exceptions that indometacin did not inhibit TNF-, levels and dexamethasone did not inhibit KC levels (P > 0.05). These results indicate that Solidago chilensis has a significant anti-inflammatory action on acute inflammatory responses and that its inhibitory activity may be due not only to the inhibition of pro-inflammatory mediators, but also to the inhibition of leucocyte infiltration. [source]

    Effect of the motilin agonist KC 11458 on gastric emptying in diabetic gastroparesis

    A. Russo
    Summary Background :,KC 11458, a motilin agonist without antibiotic properties, accelerates gastric emptying in animals and healthy humans. Aim :,To evaluate the acute effects of KC 11458 on gastric emptying in diabetic gastroparesis. Methods :,Twenty-nine patients (6 type 1 and 23 type 2) with gastroparesis underwent assessments of: (i) gastric emptying of a solid/liquid meal using scintigraphy, (ii) glycaemic control (blood glucose at 0, 30, 60, 90 and 120 min during the gastric emptying measurement) and (iii) upper gastrointestinal and ,meal-related' symptoms (questionnaire), at baseline and after treatment with KC 11458 in a dose of 8 mg t.d.s., or placebo for 8 days. Results :,KC 11458 had no statistically significant or clinically relevant effect on gastric emptying of either the solid intragastric retention at 100 min (T100) (P = 0.87) or liquid 50% emptying time (T50) (P = 0.17) components of the meal. KC 11458 slightly worsened (P = 0.04) upper gastrointestinal symptoms when compared with placebo. The magnitude of the change in solid gastric emptying correlated with the change in the blood glucose concentration (r = 0.49; P < 0.05). Conclusions :,KC 11458, in a dose of 8 mg t.d.s. for 8 days, does not accelerate gastric emptying in patients with diabetic gastroparesis. The absence of efficacy may relate to an effect of hyperglycaemia. [source]

    Asthma prediction in school children; the value of combined IgE-antibodies and obstructive airways disease severity score,

    ALLERGY, Issue 9 2010
    K. C. Lødrup Carlsen
    To cite this article: Lødrup Carlsen KC, Söderström L, Mowinckel P, Håland G, Pettersen M, Munthe Kaas MC, Devulapalli CS, Buchmann M, Ahlstedt S, Carlsen K-H. Asthma prediction in school children; the value of combined IgE-antibodies and obstructive airways disease severity score. Allergy 2010; 65: 1134,1140. Abstract Background:, Allergic sensitisation increases the risk for asthma development. In this prospective birth cohort (Environment and Childhood Asthma) study, we hypothesized that combining quantitative measures of IgE antibodies (,-IgE) and Severity score of obstructive airways disease (OAD) at 2 years of age (Severity score) is superior to predict current asthma (CA) at 10 years than either measure alone. Secondarily, we assessed if gender modified the prediction of CA. Methods:, A follow-up study at 10 years of age was performed in 371 2-year-old children with recurrent (n = 219) or no (n = 152) bronchial obstruction with available serum analysed for ,-IgE to common food and inhalant allergens through a panel test, Phadiatop Infant® (Phadia, Uppsala, Sweden). Clinical variables included allergic sensitisation and exercise testing to characterise children with CA vs not CA at 10 years and the Severity score (0,12, 0 indicating no OAD) was used to assess risk modification. Results:, Severity score alone explained 24% (Nagelkerke R2 = 0.24) of the variation in CA, whereas ,-IgE explained only 6% (R2 = 0.06). Combining the two increased the explanatory capacity to R2 = 0.30. Gender interacted significantly with ,-IgE; whereas Severity score predicted CA in both genders, the predictive capacity of ,-IgE for CA at 10 years was significant in boys only. Conclusion:, Combining ,-IgE to inhalant allergens and Severity score at 2 years was superior to predict asthma at 10 years than either alone. Severity score predicted CA in both genders, whereas ,-IgE significantly predicted CA in boys only. [source]