RESUMO
OBJECTIVES: The mono-functional monomer 2-hydroxyethyl methacrylate (HEMA) is often added to universal adhesives (UAs) to improve surface wetting and prevent phase separation. Nevertheless, HEMA promotes water sorption and hydrolysis at adhesive interfaces, hereby affecting long-term bonding to dentin. This study investigated if two acrylamide monomers could replace HEMA in an UA formulation applied in etch-and-rinse (2E&R) and self-etch (1SE) bonding mode. METHODS: Four experimental UAs were bonded to bur-cut dentin. In addition to 12 wt% 10-MDP, 25 wt% Bis-GMA and 10 wt% TEGDMA as common monomer composition, 20 %wt ethanol and 15 %wt water as solvent, and 3 wt% polymerization-related additives, the four formulations solely differed for either the acrylamide cross-linker monomer 'FAM-201' as TEGDMA alternative and HEMA replacement, the hydroxyethyl acrylamide monomer 'HEAA' as HEMA alternative, HEMA ('HEMA+'), or extra TEGDMA in a HEMA-free control ('HEMA-'), all added in a 15 wt% concentration. The split-tooth study design involved application in 2E&R mode on one tooth half versus 1SE mode on the corresponding half. Micro-tensile bond strength of half of the micro-specimens was measured upon 1-week distilled water storage ('immediate' 1w µTBS), with the other half measured after additional 6-month storage ('aged' 6 m µTBS). Statistics involved linear mixed-effects (LME) modelling (p < .05). Additionally, interfacial TEM characterization, thin-film (TF) XRD surface analysis, LogP determination, and a cytotoxicity assay were carried out. RESULTS: FAM-201 revealed significantly higher µTBS than HEMA+ at 1w and 6 m when applied both in E&R and SE bonding modes. HEAA's µTBS was significantly lower than that of HEMA+ at 1w when applied in SE mode. TF-XRD and TEM revealed similar chemical and ultrastructural interfacial characterization, including stable 10-MDP_Ca salt nano-layering. FAM-201 was least cytotoxic and presented with an intermediary LogP, while HEAA presented with the highest LogP, indicating high hydrophilicity and water-sorption sensitivity. SIGNIFICANCE: The acrylamide co-monomer FAM-201 could replace HEMA in an UA formulation, while HEAA not.
Assuntos
Colagem Dentária , Cimentos Dentários , Cimentos Dentários/química , Cimentos de Resina/química , Adesivos Dentinários/química , Acrilamida , Metacrilatos/química , Água/química , Dentina/ultraestrutura , Resistência à Tração , Teste de MateriaisRESUMO
The induction of leukemic cell differentiation is a hopeful therapeutic modality. We studied the effects of monochloramine (NH2Cl) on erythroleukemic K562 cell differentiation, and compared the effects observed with those of U0126 and staurosporine, which are known inducers of erythroid and megakaryocytic differentiation, respectively. CD235 (glycophorin) expression, a marker of erythroid differentiation, was significantly increased by NH2Cl and U0126, along with an increase in cd235 mRNA levels. Other erythroid markers such as γ-globin and CD71 (transferrin receptor) were also increased by NH2Cl and U0126. In contrast, CD61 (integrin ß3) and CD42b (GP1bα) expression, markers of megakaryocytic differentiation, was increased by staurosporine, but did not change significantly by NH2Cl and U0126. NH2Cl retarded cell proliferation without a marked loss of viability. When ERK phosphorylation (T202/Y204) and CD235 expression were compared using various chemicals, a strong negative correlation was observed (r = -0.76). Paradoxically, NH2Cl and staurosporine, but not U0126, induced large cells with multiple or lobulated nuclei, which was characteristic to megakaryocytes. NH2Cl increased the mRNA levels of gata1 and scl, decreased that of gata2, and did not change those of pu.1 and klf1. The changes observed in mRNA expression were different from those of U0126 or staurosporine. These results suggest that NH2Cl induces the bidirectional differentiation of K562. Oxidative stress may be effective in inducing leukemic cell differentiation.
Assuntos
Cloraminas/farmacologia , Leucemia Eritroblástica Aguda/tratamento farmacológico , Leucemia Eritroblástica Aguda/patologia , Megacariócitos/citologia , Butadienos/farmacologia , Técnicas de Cultura de Células , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Forma Celular/efeitos dos fármacos , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Glicoforinas/biossíntese , Humanos , Integrina beta3/biossíntese , Células K562 , Leucemia Eritroblástica Aguda/metabolismo , Megacariócitos/efeitos dos fármacos , Megacariócitos/metabolismo , Nitrilas/farmacologia , Estresse Oxidativo , Fosforilação , Estaurosporina/farmacologiaAssuntos
Antibacterianos/uso terapêutico , Bronquiolite/tratamento farmacológico , Bronquiolite/microbiologia , Quimiocina CCL2/metabolismo , Eritromicina/uso terapêutico , Granuloma/tratamento farmacológico , Pneumopatias/tratamento farmacológico , Infecções por Pseudomonas , Animais , Antibacterianos/farmacologia , Bronquiolite/patologia , Modelos Animais de Doenças , Eritromicina/farmacologia , Células Espumosas/patologia , Granuloma/etiologia , Granuloma/patologia , Pneumopatias/etiologia , Pneumopatias/patologia , Masculino , Infiltração de Neutrófilos , CoelhosRESUMO
The mechanisms underlying the therapeutic efficacy of erythromycin (EM) in diffuse panbronchiolitis (DPB) was investigated. For this purpose, an experimental rabbit model of DPB induced by Pseudomonas aeruginosa inoculation was employed. Daily administration of EM (3 mg x kg x day(-1)) led to an increase in the number of macrophages in bronchoalveolar lavage fluid (BALF) at an early phase, while reducing the size of granulomatous lesions at the late phase without affecting the number of viable bacteria recovered from the infected lung. Reverse transcriptase polymerase chain reaction (RT-PCR), enzyme-linked immunosorbent assay (ELISA) and immunohistochemical studies showed that monocyte chemoattractant protein (MCP)-1 was produced in both BALF and infected lung. EM treatment resulted in a significant increase in the level of MCP-1 in BALF, while reducing that of tumour necrosis factor (TNF)-alpha, interleukin (IL)-1beta and IL-8. EM also increased MCP-1 messenger ribonucleic acid (mRNA) and protein expression in the infected lung. MCP-1 blockade abolished the protective effect of EM, as neutralization of MCP-1 with anti-MCP-1 antibodies reduced the EM-induced increase in the number of macrophages in BALF, and augmented size of the granulomatous lesions, as compared to control. The results of the present study suggest that erythromycin attenuates the pulmonary granuloma formation, at least in part, by increasing the production of monocyte chemoattractant protein-1.
Assuntos
Bronquiolite/tratamento farmacológico , Quimiocina CCL2/fisiologia , Modelos Animais de Doenças , Eritromicina/uso terapêutico , Animais , Bronquiolite/imunologia , Doença Crônica , Masculino , CoelhosRESUMO
Chemokines constitute a large family of chemotactic cytokines that belong to a super-gene family of 8-10 kDa proteins. The chemokines are considered to be primarily beneficial in host defense against invading pathogens. However, the reactions induced by chemokines can be occasionally excessive, resulting in a harmful response to the host. Recent studies in chemokine biology have elucidated that chemokines are involved in the initiation, development, and maintenance of numbers of diseases including lung diseases. In addition to its chemotactic activity, evidence suggests that chemokines can modify the outcome of the cell-mediated immune responses by altering the Th1/Th2 cytokine profile. Chemokines are also capable of dictating the direction of specific immune responses. Chemokine action is mediated by a large super-family of G-protein coupled receptors, and the receptors are preferentially expressed on Th1/Th2 cells. Certain chemokine receptors are constitutively expressed in immune surveying cells such as dendritic cells and naive T cells. The corresponding chemokines are present in normal lymphoid tissues, suggesting a role of chemokines/receptors in cell homing and cell-cell communication in lymphoid tissue that can be an initial step for immune recognition. Thus, comprehension of the chemokine biology in immune responses appears to be fundamental for understanding the pathogenesis of T cell-mediated immune responses. The following review will highlight the current insight into the role of chemokines and their receptors in the cell-mediated immune response, with a special focus on lung diseases.
Assuntos
Quimiocinas/imunologia , Imunidade Celular/imunologia , Pulmão/imunologia , Receptores de Quimiocinas/imunologia , Animais , Quimiocinas/biossíntese , Granuloma/imunologia , Humanos , Pneumopatias/imunologia , Tecido Linfoide/imunologia , Células Th1/imunologia , Células Th2/imunologiaRESUMO
OBJECTIVE: We attempted to determine whether group IIA secretory phospholipase A2 (sPLA2-IIA) blockade after the onset of lung injury exerted therapeutic efficacy in the treatment of oleic acid (OA)-induced acute lung injury by using S-5920/LY315920Na, a novel specific inhibitor of sPLA2-IIA, with special interest in the changes of lung surfactant. DESIGN: Prospective animal study. SETTING: University laboratory. SUBJECTS: Forty Japanese white rabbits. INTERVENTIONS: The rabbits, under anesthesia, were endotracheally intubated and mechanically ventilated and then were divided into the following groups: OA + vehicle groups, intravenous infusion of OA for the first 2 hrs (0.1 mL x kg(-1) x hr(-1)) with the addition of vehicle (1 or 2 hrs after OA administration, each n = 9, total 18 rabbits); OA + S-5920/LY315920Na groups, treated identically to the OA control with the addition of S-5920/LY315920Na (1 mg/kg bolus followed by infusion at 0.5 mg x kg(-1) x hr(-1)) after OA (1 or 2 hrs after OA administration, each n = 9, total 18 rabbits); saline control groups, treated with saline instead of OA with the addition of vehicle (1 hr after OA administration, 4 rabbits). Arterial blood gas, lung mechanics, lung inflammation, lung surfactant phospholipids, and production of inflammatory mediators in the lung were measured. MEASUREMENTS AND MAIN RESULTS: Treatment with S-5920/LY315920Na 1 hr after OA infusion, but not 2 hrs after infusion, significantly attenuated the lung injury, as estimated by hypoxemia, decreased lung compliance, pulmonary edema, and vascular permeability. The therapeutic efficacy was similar to that found in our previous pretreatment study. The treatment after 1 hr dramatically inhibited OA-induced surfactant degradation in the bronchoalveolar lavage fluid (BALF), without affecting the concentrations of thromboxane A2, leukotriene B4, and interleukin-8 in BALF. The degree of surfactant degradation in BALF paralleled well with the severity of the lung injury. Furthermore, recombinant human sPLA2-IIA reproduced the similar hydrolysis pattern of isolated surfactant in vitro, which was inhibited by S-5920/LY315920Na. CONCLUSIONS: Our results indicate that therapeutic blockade of sPLA2-IIA ameliorated lung dysfunction via protection of surfactant degradation in an animal model of acute lung injury, and they suggest a new strategy in treating clinical acute lung injury.
Assuntos
Acetatos/farmacologia , Inibidores Enzimáticos/farmacologia , Indóis/farmacologia , Fosfolipases A/antagonistas & inibidores , Síndrome do Desconforto Respiratório/tratamento farmacológico , Acetatos/uso terapêutico , Animais , Gasometria , Líquido da Lavagem Broncoalveolar/química , Inibidores Enzimáticos/uso terapêutico , Fosfolipases A2 do Grupo II , Indóis/uso terapêutico , Cetoácidos , Masculino , Ácido Oleico/toxicidade , Fosfolipases A2 , Surfactantes Pulmonares/efeitos dos fármacos , Coelhos , Síndrome do Desconforto Respiratório/induzido quimicamenteRESUMO
The aim was to investigate joint perfusate levels of interleukin-1beta (IL-1beta) in antigen-induced monoarthritis of the rabbit temporomandibular (TMJ) and knee joints. Twenty-four adult male New Zealand White rabbits were divided into three groups: a control group as well as TMJ arthritis and knee joint arthritis groups. After sensitization, unilateral arthritis was induced by intra-articular injection with ovalbumin and the contralateral joint was injected with saline 3 weeks after induction of arthritis. Joints were then perfused continuously with saline and samples were collected at 10-min intervals over a 50-min period. The IL-1beta concentrations in the samples were then analyzed. After killing the animals, the joints were examined histologically. The IL-1beta concentrations in the samples from the arthritic TMJs and knee joints were significantly higher than in the saline-injected and the control joints. Histological signs of chronic arthritis of similar severity were found in both joints. The IL-1beta levels in the samples from the arthritic TM and knee joints correlated with the histological severity of the arthritis, including pannus formation. In conclusion, this study shows that IL-1beta is released in the synovium of rabbit TMJs and knee joints during antigen-induced arthritis, and that high IL-1beta levels in synovial fluid are associated with histological signs of inflammation including, pannus tissue formation.
Assuntos
Artrite Experimental/imunologia , Interleucina-1/análise , Transtornos da Articulação Temporomandibular/imunologia , Adjuvantes Imunológicos/administração & dosagem , Animais , Artrite Experimental/classificação , Artrite Experimental/patologia , Imunização , Injeções Intra-Articulares , Articulação do Joelho/imunologia , Articulação do Joelho/patologia , Masculino , Ovalbumina/administração & dosagem , Coelhos , Cloreto de Sódio , Estatísticas não Paramétricas , Líquido Sinovial/imunologia , Transtornos da Articulação Temporomandibular/patologiaRESUMO
Signal transducer and activator of transcription (Stat)4 and Stat6 are transcription factors that provide type 1 and type 2 response, respectively. Here, we explored the role of Stat4 and Stat6 in innate immunity during septic peritonitis. Stat4-/- and Stat6-/- mice were resistant to the lethality compared with wild-type (WT) mice. At the mechanistic level, bacterial levels in Stat6-/- mice were much lower than in WT mice, which was associated with increased peritoneal levels of interleukin (IL)-12, tumor necrosis factor (TNF)-alpha, macrophage-derived chemokine (MDC), and C10, known to enhance bacterial clearance. In Stat4-/- mice, hepatic inflammation and injury during sepsis were significantly ameliorated without affecting local responses. This event was associated with increased hepatic levels of IL-10 and IL-13, while decreasing those of macrophage inflammatory protein (MIP)-2 and KC. Sepsis-induced renal injury was also abrogated in Stat4-/- mice, which was accompanied by decreased renal levels of MIP-2 and KC without altering IL-10 and IL-13 levels. Thus, Stat6-/- and Stat4-/- mice appeared to be resistant to septic peritonitis by enhancing local bacterial clearance and modulating systemic organ damage, respectively, via balancing cytokine responses. These results clearly highlight an important role of local type 1 and systemic type 2 cytokine response in protective immunity during sepsis, which can be regulated by Stat proteins.
Assuntos
Proteínas de Ligação a DNA/imunologia , Peritonite/imunologia , Sepse/imunologia , Transdução de Sinais/imunologia , Transativadores/imunologia , Animais , Quimiocina CCL22 , Quimiocinas/metabolismo , Quimiocinas CC/metabolismo , Citocinas/metabolismo , Proteínas de Ligação a DNA/genética , Feminino , Imunidade Inata , Interleucina-12/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Knockout , Insuficiência de Múltiplos Órgãos/imunologia , Peritônio/microbiologia , Peritonite/sangue , Peritonite/microbiologia , Fator de Transcrição STAT4 , Fator de Transcrição STAT6 , Sepse/sangue , Sepse/microbiologia , Transativadores/genética , Fator de Necrose Tumoral alfa/metabolismoRESUMO
The contribution of neutrophils to lethal sensitivity and cytokine balance governing T1 and T2 host responses was assessed in a murine model of Legionella pneumophila pneumonia. Neutrophil depletion by administration of granulocyte-specific mAb RB6-8C5 at 1 day before infection rendered mice approximately 100-fold more susceptible to lethal pneumonia induced by L. pneumophila. However, this treatment did not alter early bacterial clearance, despite a substantial decrease in neutrophil influx at this time point. Cytokine profiles in the lungs of control mice demonstrated strong T1 responses, characterized by an increase of IFN-gamma and IL-12. In contrast, neutrophil-depleted mice exhibited significantly lower levels of IFN-gamma and IL-12, and elevation of T2 cytokines, IL-4 and IL-10. Immunohistochemistry of bronchoalveolar lavage cells demonstrated the presence of IL-12 in neutrophils, but not alveolar macrophages. Moreover, IL-12 was detected in lavage cell lysates by ELISA, which was paralleled to neutrophil number. However, intratracheal administration of recombinant murine IL-12 did not restore resistance, whereas reconstitution of IFN-gamma drastically improved bacterial clearance and survival in neutrophil-depleted mice. Taken together, these data demonstrated that neutrophils play crucial roles in primary L. pneumophila infection, not via direct killing but more immunomodulatory effects. Our results suggest that the early recruitment of neutrophils may contribute to T1 polarization in a murine model of L. pneumophila pneumonia.
Assuntos
Legionella pneumophila/imunologia , Doença dos Legionários/imunologia , Infiltração de Neutrófilos/imunologia , Pneumonia Bacteriana/imunologia , Células Th1/imunologia , Células Th2/imunologia , Animais , Anticorpos Monoclonais/administração & dosagem , Líquido da Lavagem Broncoalveolar/citologia , Líquido da Lavagem Broncoalveolar/imunologia , Contagem de Colônia Microbiana , Citocinas/análise , Citocinas/biossíntese , Modelos Animais de Doenças , Feminino , Imuno-Histoquímica , Injeções Intraperitoneais , Interferon gama/administração & dosagem , Interleucina-12/administração & dosagem , Interleucina-12/metabolismo , Intubação Intratraqueal , Doença dos Legionários/microbiologia , Doença dos Legionários/mortalidade , Doença dos Legionários/patologia , Contagem de Leucócitos , Pulmão/imunologia , Pulmão/metabolismo , Pulmão/microbiologia , Pulmão/patologia , Camundongos , Camundongos Endogâmicos A , Camundongos Endogâmicos C57BL , Neutropenia/imunologia , Neutropenia/microbiologia , Pneumonia Bacteriana/microbiologia , Pneumonia Bacteriana/mortalidade , Pneumonia Bacteriana/patologia , Proteínas Recombinantes/administração & dosagem , Análise de Sobrevida , Células Th1/química , Células Th1/metabolismo , Células Th2/química , Células Th2/metabolismoRESUMO
Glucocorticoids are the most potent and widely used anti-inflammatory agents, but they are not particularly effective against early phase of acute respiratory distress syndrome. We investigated whether methylprednisolone, a synthetic glucocorticoid, could inhibit increase of phospholipase A(2) activity in the lung and lead to protection against a model of acute respiratory distress syndrome in rabbits. Infusion of oleic acid (0.1 ml/kg/h, i.v. for 2 h) provoked pulmonary hemorrhage and edema, protein leakage and massive neutrophil infiltration, resulted in severe hypoxemia and impaired lung compliance, accompanying the increase of phospholipase A(2) activity and interleukin-8, and degradation of surfactant in the bronchoalveolar lavage fluid. Infusion of methylprednisolone (60 mg/kg/h, i.v. for 30 min before the oleic acid and then 0.5 mg/kg/h, i.v. for 6 h) did not improve the above described lung injury induced by oleic acid, nor did it suppress phospholipase A(2) activity and degradation of surfactant in bronchoalveolar lavage fluid, while it strongly reduced interleukin-8 levels in both plasma and bronchoalveolar lavage fluid. We conclude that methylprednisolone did not attenuate oleic acid-induced acute lung injury and this can be explained partly by its failure to reduce the increase of phospholipase A(2) activity and the surfactant degradation in the lung, which might also account for its clinical ineffectiveness against early acute respiratory distress syndrome.
Assuntos
Pulmão/efeitos dos fármacos , Metilprednisolona/farmacologia , Fosfolipases A/metabolismo , Surfactantes Pulmonares/metabolismo , Síndrome do Desconforto Respiratório/prevenção & controle , Animais , Líquido da Lavagem Broncoalveolar/química , Líquido da Lavagem Broncoalveolar/citologia , Permeabilidade Capilar/efeitos dos fármacos , Eicosanoides/análise , Interleucina-8/sangue , Pulmão/metabolismo , Pulmão/patologia , Masculino , Ácido Oleico , Coelhos , Síndrome do Desconforto Respiratório/metabolismoRESUMO
Previous studies have suggested that the C-C chemokine C10 is involved in the chronic stages of host defense reactions. The present study addressed the role of C10 in a murine model of septic peritonitis, induced by cecal ligation and puncture (CLP). Unlike other C-C chemokines, C10 levels in the peritoneal wash were increased approximately 30-fold above baseline levels at 48 h after CLP surgery. Immunoneutralization of peritoneal C10 levels with polyclonal anti-C10 antiserum during CLP-induced peritonitis negatively impacted mouse survival over 4 days. In contrast, when 500 ng of recombinant murine C10 was administered immediately after CLP surgery, the 4-day survival rate increased from 20% to over 60%. The C10 therapy appeared to facilitate a rapid and significant enhancement of the levels of tumor necrosis factor alpha (TNF-alpha) and monocyte chemoattractant protein-1 (MCP-1) and a later increase in interleukin-13 (IL-13) levels in the peritoneal cavity. In vitro studies showed that the combination of IL-1beta and C10 markedly augmented TNF-alpha synthesis by peritoneal macrophages and that C10 synthesis was induced in these cells following their exposure to IL-13. At 24 h after CLP surgery, only 25% of C10-treated mice were bacteremic versus 85% of the control group that exhibited dissemination of bacteria into the circulation. The lack of bacteremia in C10-treated mice appeared to be related, in part, to in vitro evidence that C10 significantly enhanced the bacterial phagocytic activity of peritoneal macrophages. In addition, in vivo evidence suggested that C10 therapy significantly reduced the amount of material that leaked from the damaged gut. Taken together, the results of this study demonstrate that the C10 chemokine rapidly promotes disease resolution in the CLP model through its direct effects on the cellular events critically involved in host defense during septic peritonitis.
Assuntos
Bacteriemia/imunologia , Quimiocinas CC/fisiologia , Animais , Bacteriemia/mortalidade , Bacteriemia/terapia , Quimiocina CCL2/biossíntese , Quimiocinas CC/uso terapêutico , Feminino , Soros Imunes/imunologia , Interleucina-1/farmacologia , Interleucina-13/biossíntese , Interleucina-13/farmacologia , Camundongos , Fagocitose , Coelhos , Proteínas Recombinantes/uso terapêutico , Fator de Necrose Tumoral alfa/biossínteseRESUMO
The aim of this study was to assess the acute effects of cigarette smoke exposure on cellular and cytokine profile in BAL fluids in an isolated perfused rabbit assay. The experimental animals were categorized into four groups: (1) unexposed controls and (2) cigarette smoke-exposed animals perfused with autologous whole blood; (3) unexposed controls and cigarette smoke-exposed; (4) cigarette smoke-exposed animals perfused with Krebs' Ringer solution containing 5% bovine serum albumin and glucose. Cigarette smoke induced an increase in total cell numbers (mainly alveolar macrophages in BAL fluids) and an increase in the permeability index of BAL. Levels of interleukin 8 were also significantly decreased in BAL fluids due to acute effects of cigarette smoke exposure. The most likely explanation for cigarette smoke-induced increase of inflammatory cells in BAL in lungs is because of the release of pre-existing cells from reservoirs within the lungs. The acute effects of cigarette smoke-induced increase of pulmonary epithelial permeability may also play an important role in the cellular recruitment into airspaces from the lung reservoirs.
Assuntos
Citocinas/metabolismo , Pulmão/metabolismo , Pulmão/patologia , Poluição por Fumaça de Tabaco/efeitos adversos , Animais , Líquido da Lavagem Broncoalveolar/citologia , Contagem de Células , Técnicas In Vitro , Interleucina-8/metabolismo , Perfusão , Permeabilidade , CoelhosRESUMO
Chemokines are involved in a number of pathological processes, and therefore represent important targets. However, it has also become apparent that chemokines have exciting therapeutic applications in inflammatory, infectious and cancer-related diseases. The following review will highlight the application of novel therapies including viral-encoded, recombinant, and genetically engineered chemokines to a number of diseases or disorders. Advances in the application of novel chemokine delivery procedures both at the research bench and the clinical bedside will also be discussed. Overall, the utilization of chemokines to prevent and treat disease has tremendous potential.
Assuntos
Quimiocinas/uso terapêutico , Animais , Quimiocinas/biossíntese , Quimiocinas/farmacologia , HumanosRESUMO
Macrophage-derived chemokine (MDC), a recently identified CC chemokine, has been regarded to be involved in chronic inflammation and dendritic cell and lymphocyte homing. In this study, we demonstrate a pivotal role for MDC during experimental sepsis induced by cecal ligation and puncture (CLP). Intraperitoneal administration of MDC (1 microg/mouse) protected mice from CLP-induced lethality. The survival was accompanied by increased number of peritoneal macrophages and decreased recovery of viable bacteria from the peritoneum and peripheral blood. In addition, mice treated with an i.p. injection of MDC cleared bacteria more effectively than those in the control when 3 x 108 CFU live Escherichia coli was i.p. inoculated. Endogenous MDC was detected in the peritoneum after CLP, and neutralization of the MDC with anti-MDC Abs decreased CLP-induced recruitment of peritoneal macrophages and increased the recovery of viable bacteria from the peritoneum and peripheral blood. MDC blockade was deleterious in the survival of mice after CLP. In vitro, MDC enhanced the phagocytic and killing activities of peritoneal macrophages to E. coli and induced both a respiratory burst and the release of lysozomal enzyme from macrophages. Furthermore, MDC dramatically ameliorated CLP-induced systemic tissue inflammation as well as tissue dysfunction, which were associated in part with decreased levels of TNF-alpha, macrophage inflammatory proteins-1alpha and -2, and KC in specific tissues. Collectively, these results indicate novel regulatory activities of MDC in innate immunity during sepsis and suggest that MDC may aid in an adjunct therapy in sepsis.
Assuntos
Quimiocinas CC/fisiologia , Macrófagos Peritoneais/imunologia , Animais , Ceco , Movimento Celular/imunologia , Quimiocina CCL22 , Quimiocinas CC/administração & dosagem , Quimiocinas CC/antagonistas & inibidores , Quimiocinas CC/imunologia , Citotoxicidade Imunológica , Escherichia coli/imunologia , Feminino , Imunidade Inata , Injeções Intraperitoneais , Injeções Intravenosas , Ligadura/efeitos adversos , Lisossomos/enzimologia , Lisossomos/metabolismo , Macrófagos Peritoneais/enzimologia , Macrófagos Peritoneais/metabolismo , Macrófagos Peritoneais/microbiologia , Camundongos , Peritonite/imunologia , Peritonite/microbiologia , Peritonite/mortalidade , Peritonite/prevenção & controle , Fagocitose/imunologia , Punções/efeitos adversos , Explosão Respiratória/imunologia , Sepse/imunologia , Sepse/microbiologia , Sepse/mortalidade , Sepse/prevenção & controleRESUMO
Monocyte chemoattractant protein-1 is one of the major C-C chemokines that has been implicated in liver injury. The C-C chemokine receptor, CCR2, has been identified as the primary receptor that mediates monocyte chemoattractant protein-1 (MCP-1) responses in the mouse. Accordingly, the present study addressed the role of CCR2 in mice acutely challenged with acetaminophen (APAP). Mice genetically deficient in CCR2 (CCR2(-/-)) and their wild-type counterparts (CCR2(+/+)) were fasted for 10 hours before receiving an intraperitoneal injection of APAP (300 mg/kg). Liver and serum samples were removed from both groups of mice before and at 24 and 48 hours post APAP. Significantly elevated levels of MCP-1 were detected in liver samples from CCR2(+/+) and CCR2(-/-) mice at 24 hours post-APAP. Although CCR2(+/+) mice exhibited no liver injury at any time after receiving APAP, CCR2(-/-) mice exhibited marked evidence of necrotic and TUNEL-positive cells in the liver, particularly at 24 hours post-APAP. Enzyme-linked immunosorbent assay analysis of liver homogenates from both groups of mice at the 24 hours time point revealed that liver tissue from CCR2(-/-) mice contained significantly greater amounts of immunoreactive IFN-gamma and TNF-alpha. The in vivo immunoneutralization of IFN-gamma or TNF-alpha significantly attenuated APAP-induced liver injury in CCR2(-/-) mice and increased hepatic IL-13 levels. Taken together, these findings demonstrate that CCR2 expression in the liver provides a hepatoprotective effect through its regulation of cytokine generation during APAP challenge.
Assuntos
Acetaminofen/intoxicação , Doença Hepática Induzida por Substâncias e Drogas , Fígado/efeitos dos fármacos , Fígado/metabolismo , Receptores de Quimiocinas/deficiência , Animais , Anticorpos/imunologia , Apoptose , Quimiocina CCL2/metabolismo , Soros Imunes/imunologia , Interferon gama/metabolismo , Interleucina-13/imunologia , Interleucina-13/metabolismo , Fígado/patologia , Fígado/fisiopatologia , Hepatopatias/patologia , Camundongos , Necrose , Receptores CCR2 , Receptores de Quimiocinas/metabolismo , Fator de Necrose Tumoral alfa/imunologia , Fator de Necrose Tumoral alfa/metabolismoRESUMO
BACKGROUND: 21-aminosteroids (lazaroids) have demonstrated the protective effect against cerebral ischemic injury through the inhibition of lipid peroxidation. We examined whether lazaroids affected the production of proinflammatory and antiinflammatory cytokines in ischemic spinal cord injury model. MATERIALS: Anesthetized New Zealand white rabbits underwent a 20-minute infrarenal aortic cross-clamping (AXC) with pretreatment of either an intravenous 3 mg/kg lazaroid U74389G (group L; n = 10) or the same volume saline (group P; n = 10). Sham operation group (group S; n = 6) underwent only exposure of the aorta. Plasma concentrations of interleukin (IL)-8, -1beta, -1 receptor antagonist (IL-1ra) and tumor necrosis factor (TNF)-alpha were measured at four time points. Functional assessment with Tarlov score at 24 and 48 hours after pretreatment, pathologic assessment of the spinal cord, and measurements of cytokine levels in the spinal cord were performed. RESULTS: The maximum elevation of plasma IL-8 and -1ra levels occurred at 1 hour after declamping in four measurement points. Plasma IL-8 and -1ra levels in group L were significantly lower than those in group P (*p < 0.05). Plasma TNFalpha peaked at 5 minutes after declamping, but decreased afterwards. Plasma TNFalpha levels were not different among three groups. Spinal IL-8 levels in group L (0.98 +/- 0.34 ng/g tissue) were lower than those in group P (7.26 +/- 2.26 ng/g tissue)(*p < 0.05). Spinal IL-1ra and TNFalpha were not significantly different. Tarlov score and pathologic assessment were better in group L. CONCLUSIONS: Lazaroid U-74389G reduced the production of systemic IL-8 and -1ra and spinal IL-8 when AXC caused spinal cord injury. These results indicate that lazaroids may attenuate ischemic endothelial cell injury or activation of leukocytes.
Assuntos
Interleucina-8/biossíntese , Fármacos Neuroprotetores/farmacologia , Pregnatrienos/farmacologia , Receptores de Interleucina-1/antagonistas & inibidores , Sialoglicoproteínas/biossíntese , Traumatismos da Medula Espinal/metabolismo , Animais , Proteína Antagonista do Receptor de Interleucina 1 , Isquemia/complicações , Coelhos , Traumatismos da Medula Espinal/etiologiaRESUMO
Sepsis and septic syndrome represent an intense systemic response with multiple physiologic and immunologic abnormalities, leading to multiple organ failure. Recent investigations suggest that the critical conditions are balanced by endogenous cytokines. In the present study, we examined the involvement of endogenous monocyte chemoattractant protein (MCP)-1 in the regulation of cytokine production in tissue/organs in a murine model of acute septic peritonitis induced by cecal ligation and puncture (CLP). Initial studies showed that CLP induced elevated levels of MCP-1 in tissues, such as liver, lung, and kidney. To neutralize endogenous MCP-1, either anti-MCP-1 antibodies or control antibodies were intraperitoneally administered 2 h prior to CLP. Administration of anti-MCP-1 antibodies resulted in a decrease in the level of interleukin (IL)-13 in tissues, while increasing the level of tumor necrosis factor-alpha, compared to control. In addition, anti-MCP-1 treatment decreased the level of IL-12 and, in contrast, increased the level of IL-10 in specific tissues. These findings suggest that endogenous MCP-1 influences the cytokine balance in tissues in favor of anti-inflammatory and immune-enhancing cytokines, probably protecting the host from tissue/organ damage during sepsis.
Assuntos
Quimiocina CCL2/metabolismo , Citocinas/metabolismo , Peritonite/metabolismo , Sepse/metabolismo , Doença Aguda , Animais , Bacteriemia/microbiologia , Quimiocina CCL2/imunologia , Contagem de Colônia Microbiana , Feminino , Soros Imunes/farmacologia , Camundongos , Peritonite/microbiologia , Sepse/microbiologiaRESUMO
IL-13 has been shown to exert potent anti-inflammatory properties. In this study, we elucidated the functional role of endogenous IL-13 in a murine model of septic peritonitis induced by cecal ligation and puncture (CLP). Initial studies demonstrated that the level of IL-13 increased in tissues including liver, lung, and kidney, whereas no considerable increase was found in either peritoneal fluid or serum after CLP. Immunohistochemically, IL-13-positive cells were Kupffer cells in liver, alveolar macrophages in lung, and epithelial cells of urinary tubules in kidney. IL-13 blockade with anti-IL-13 Abs significantly decreased the survival rate of mice after CLP from 53% to 14% on day 7 compared with control. To determine the potential mechanisms whereby IL-13 exerted a protective role in this model, the effects of anti-IL-13 Abs on both local and systemic inflammation were investigated. Administration of anti-IL-13 Abs did not alter the leukocyte infiltration and bacterial load in the peritoneum after CLP but dramatically increased the neutrophil influx in tissues after CLP, an effect that was accompanied by significant increases in the serum levels of aspartate transaminase, alanine transaminase, blood urea nitrogen, and creatinine. Tissue injury caused by IL-13 blockade was associated with increases in mRNA and the protein levels of CXC chemokines macrophage inflammatory protein-2 and KC as well as the CC chemokine macrophage inflammatory protein-1alpha and the proinflammatory cytokine TNF-alpha. Collectively, these results suggest that endogenous IL-13 protected mice from CLP-induced lethality by modulating inflammatory responses via suppression of overzealous production of inflammatory cytokines/chemokines in tissues.
Assuntos
Interleucina-13/biossíntese , Interleucina-13/imunologia , Sepse/imunologia , Animais , Ceco/cirurgia , Quimiocina CCL4 , Quimiocina CXCL1 , Quimiocina CXCL2 , Quimiocinas/biossíntese , Quimiocinas CXC , Citocinas/biossíntese , Modelos Animais de Doenças , Feminino , Soros Imunes/farmacologia , Inflamação/imunologia , Inflamação/metabolismo , Inflamação/patologia , Interleucina-13/antagonistas & inibidores , Rim/imunologia , Rim/metabolismo , Rim/patologia , Ligadura , Fígado/imunologia , Fígado/metabolismo , Fígado/patologia , Pulmão/imunologia , Pulmão/metabolismo , Pulmão/patologia , Proteínas Inflamatórias de Macrófagos/biossíntese , Camundongos , Punções , Sepse/etiologia , Sepse/mortalidade , Sepse/patologia , Fator de Necrose Tumoral alfa/biossínteseRESUMO
The expression of chemokines during an immune response may participate in determining the intensity and type of the developing immune response. In the present study, we have examined the effect of overexpressing monocyte chemoattractant protein (MCP)-1 at the site of immunization during different stages of Th1- and Th2-type granulomatous responses. The overexpression of MCP-1 by MCP-1 adenovirus during the sensitization phase of the purified protein derivative Th1-type model significantly reduced the elicitation of the granulomatous response. In contrast, the overexpression of MCP-1 during the sensitization phase of the schistosome egg Ag Th2 response led to an enhanced granulomatous reaction. When cytokines were examined upon restimulation of splenocytes ex vivo, an altered cytokine profile was observed, as compared with control mice. IFN-gamma and IL-12 were significantly reduced in the purified protein derivative Th1-type response, whereas IL-10 and IL-13 were up-regulated in the schistosome egg Ag Th2-type response. The regulation of the immune response was further examined by using the MCP-1 adenovirus at later time points during the elicitation phase. When MCP-1 was overexpressed during the elicitation phase of the responses, neither the Th1-type nor the Th2-type granuloma was altered. Likewise, the cytokine profiles after restimulation of splenocytes ex vivo were unchanged. Thus, the function of MCP-1 may depend on the stage and type of immune response.