RESUMO
This is an animal model study to investigate changes in hemostasis during endotoxemic shock and to determine whether the combination of inhaled nitric oxide (iNO) + intravenous hydrocortisone had an effect on clot formation and fibrinolysis. iNO selectively decreases pulmonary artery pressure, without affecting cardiac index or systemic vascular resistance; however, the results of studies on the possible consequences of iNO administration on coagulation are inconsistent and require further research. Thirty-four piglets were included. Administering endotoxin caused severe hypodynamic shock. Half of the animals received iNO (30 ppm) + hydrocortisone, starting 3 h after endotoxin infusion and continuing to the end of the study. All animals developed coagulation disorders, manifested by a tendency to hypocoagulation; at the same time, fibrinolysis was impaired. Coagulation and fibrinolysis disorders persisted after endotoxin infusion was discontinued, with worse severity in the animals that died before the study was terminated. Administering iNO + hydrocortisone did not cause further changes in coagulation and fibrinolysis parameters, either during or after the endotoxin challenge, suggesting that potential therapeutic interventions with iNO to lower pulmonary arterial pressure will not affect hemostasis.
Assuntos
Coagulação Sanguínea , Modelos Animais de Doenças , Fibrinólise , Hidrocortisona , Óxido Nítrico , Choque Séptico , Tromboelastografia , Animais , Hidrocortisona/administração & dosagem , Hidrocortisona/uso terapêutico , Hidrocortisona/farmacologia , Óxido Nítrico/metabolismo , Fibrinólise/efeitos dos fármacos , Suínos , Coagulação Sanguínea/efeitos dos fármacos , Choque Séptico/tratamento farmacológico , Administração por Inalação , Endotoxinas/administração & dosagem , Humanos , Transtornos da Coagulação Sanguínea/tratamento farmacológicoRESUMO
Endotoxin administration is commonly used to study the inflammatory response, and though traditionally given as a bolus injection, it can be administered as a continuous infusion over multiple hours. Several studies hypothesize that the latter better represents the prolonged and pronounced inflammation observed in conditions like sepsis. Yet very few experimental studies have administered endotoxin using both strategies, leaving significant gaps in determining the underlying mechanisms responsible for their differing immune responses. We used mathematical modelling to analyse cytokine data from two studies administering a 2 ng kg-1 dose of endotoxin, one as a bolus and the other as a continuous infusion over 4 h. Using our model, we simulated the dynamics of mean and subject-specific cytokine responses as well as the response to long-term endotoxin administration. Cytokine measurements revealed that the bolus injection led to significantly higher peaks for interleukin (IL)-8, while IL-10 reaches higher peaks during continuous administration. Moreover, the peak timing of all measured cytokines occurred later with continuous infusion. We identified three model parameters that significantly differed between the two administration methods. Monocyte activation of IL-10 was greater during the continuous infusion, while tumour necrosis factor α $ {\alpha} $ and IL-8 recovery rates were faster for the bolus injection. This suggests that a continuous infusion elicits a stronger, longer-lasting systemic reaction through increased stimulation of monocyte anti-inflammatory mediator production and decreased recovery of pro-inflammatory catalysts. Furthermore, the continuous infusion model exhibited prolonged inflammation with recurrent peaks resolving within 2 days during long-term (20-32 h) endotoxin administration.
Assuntos
Citocinas , Endotoxinas , Humanos , Endotoxinas/administração & dosagem , Endotoxinas/imunologia , Citocinas/metabolismo , Masculino , Inflamação/imunologia , Interleucina-10/metabolismo , Modelos Teóricos , Infusões Intravenosas , Monócitos/imunologia , Monócitos/efeitos dos fármacos , Interleucina-8/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Adulto , Feminino , Lipopolissacarídeos/administração & dosagemRESUMO
OBJECTIVE: The systemic inflammatory response is regarded as the major cause of endotoxin-induced coagulopathy, which is a strong predictor of mortality in patients with severe sepsis. Simvastatin plays an important role in reducing inflammation. In addition, the gut has long been hypothesized to be the "motor" of critical illness, driving or aggravating sepsis by the increased intestinal permeability and bacterial translocation. Whether simvastatin plays a role in severe endotoxin-induced coagulopathy through the gut is unclear. METHODS: In this study, mice were administered 20 mg/kg simvastatin by gavage for 2 weeks and then intraperitoneally injected with 50 mg/kg endotoxin. Twelve h later, cytokine release, coagulation dysfunction, organ damage, and survival were assessed. Besides, the intestinal barrier, permeability, bacteria abundance, and translocation were evaluated. RESULTS: We found that the severity of endotoxin-induced coagulopathy was significantly improved in simvastatin-pretreated mice, who showed attenuated depletion of coagulation factors and platelets, decreased plasminogen activator inhibitor-1 (PAI-1) expression, reduced organ fibrin deposition, and improved survival time. Also, simvastatin reduced epithelial apoptosis and improved intestinal barrier function by upregulating antimicrobial peptides, lysozyme, and mucins. Simvastatin increased Lactobacillales counts, while the lipopolysaccharide group showed increased Desulfovibrio and Mucispirillum, which can produce harmful toxins. Finally, the decreased intestinal permeability in the simvastatin group caused reduced bacterial translocation in the organs and blood, both in terms of quantity and species. CONCLUSION: Simvastatin improves the prognosis of severe endotoxemia, and the intestinal microenvironment participates in this process.
Assuntos
Transtornos da Coagulação Sanguínea/prevenção & controle , Endotoxemia/prevenção & controle , Endotoxinas/farmacologia , Microbioma Gastrointestinal , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Enteropatias/prevenção & controle , Sinvastatina/farmacologia , Animais , Transtornos da Coagulação Sanguínea/induzido quimicamente , Modelos Animais de Doenças , Endotoxemia/induzido quimicamente , Endotoxinas/administração & dosagem , Inibidores de Hidroximetilglutaril-CoA Redutases/administração & dosagem , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Sinvastatina/administração & dosagemRESUMO
Cancer immunotherapy is emerging as a viable treatment option for several types of cancer. Active immunotherapy aims for the induction of specific antitumor immune responses; this goal requires strategies capable of increasing the immunogenicity of tumour antigens. Parvovirus B19 virus-like particles (B19-VLPs) formed of VP2 protein had been shown to be an effective multi-neoepitope delivery system capable of inducing specific cellular responses towards coupled antigens and reducing tumour growth and lung metastases in triple negative breast cancer mouse model. These findings encouraged us to further characterise these VP2 B19-VLPs by testing their capacity to simultaneously induce cellular and humoral responses towards other tumour-associated antigens, as this had not yet been evaluated. Here, we designed and evaluated in the 4T1 breast cancer model the prophylactic and therapeutic effect of VP2 B19-VLPs decorated with cellular (P53) and humoral (MUC1) epitopes. Balb/c mice were immunised with chimaeric VLPs, vehicle, or VLPs plus adjuvant. Tumour establishment and growth, lung metastasis, and cellular and humoral immune responses were evaluated. The prophylactic administration of chimaeric VLPs without adjuvant prevented the establishment of the tumour, while by therapeutic administration, chimaeric VLPs induced smaller tumour growth and decreased the number of metastases in the lung compared to wild-type VLPs. chimaeric VLPs induced high antibody titres towards the MUC1 epitope, as well as specific cellular responses towards P53 epitopes in lymph nodes local to the tumour. Our results reinforce and extend the utility of VP2 B19-VLPs as an encouraging tumour antigen delivery system in cancer immunotherapy able to improve tumour immunity in TNBC by inducing cellular and humoral immune responses.
Assuntos
Antígenos de Neoplasias/imunologia , Vacinas Anticâncer/imunologia , Parvovirus B19 Humano/imunologia , Neoplasias de Mama Triplo Negativas/terapia , Vacinas de Partículas Semelhantes a Vírus/imunologia , Adjuvantes Imunológicos/administração & dosagem , Animais , Antígenos de Neoplasias/administração & dosagem , Toxinas de Bacillus thuringiensis/administração & dosagem , Vacinas Anticâncer/administração & dosagem , Linhagem Celular Tumoral , Modelos Animais de Doenças , Endotoxinas/administração & dosagem , Feminino , Proteínas Hemolisinas/administração & dosagem , Humanos , Imunidade Celular , Imunidade Humoral , Imunogenicidade da Vacina , Proteínas de Insetos , Camundongos , Receptores de Superfície Celular , Neoplasias de Mama Triplo Negativas/imunologia , Neoplasias de Mama Triplo Negativas/patologia , Vacinas de Partículas Semelhantes a Vírus/administração & dosagemRESUMO
2,4-Dichlorophenoxyacetic acid (2,4-D), a member of the phenoxy family of herbicides is commonly used in agriculture for controlling broadleaf weeds but its uncontrolled and incoherent use has been linked to incidences of lung toxicity. The present study aimed to understand the molecular mechanisms behind the 2,4-D alone or in combination with endotoxin (lipopolysaccharide [LPS]) induced pulmonary toxicity. Blood and lung samples were collected from Swiss albino mice (n = 48) following chronic exposure to high (37 mg/kg; 1/10th of LD50 ) and low (18.5 mg/kg; 1/20th of LD50 ) doses of 2,4-D alone or in combination with endotoxin (80 µg/animal). Transcriptome analysis revealed Wnt Canonical signaling as one of the top dysregulated pathways in mice lung following exposure to 2,4-D with and without endotoxin (LPS) co-exposure. Global view of differentially expressed genes showed increased messenger RNA expression of Axin2 by 0.26, 2.58, 3.14, 2.59, and 2.97 folds following exposure to LPS, high dose alone or in combination with LPS and low dose alone or in combination with LPS, respectively. The microarray data were validated using quantitative polymerase chain reaction and immunohistochemistry. Furthermore, the plasma concentration of Axin2 was elevated in the high dose group as revealed by Sandwich ELISA. The data taken together suggest a role of Axin2 to activate the Canonical Wnt signaling pathway in 2,4-D and or endotoxin-induced lung damage in mice.
Assuntos
Ácido 2,4-Diclorofenoxiacético/toxicidade , Proteína Axina/metabolismo , Endotoxinas/toxicidade , Herbicidas/toxicidade , Pulmão/efeitos dos fármacos , Ácido 2,4-Diclorofenoxiacético/administração & dosagem , Animais , Proteína Axina/sangue , Regulação para Baixo/efeitos dos fármacos , Endotoxinas/administração & dosagem , Perfilação da Expressão Gênica , Herbicidas/administração & dosagem , Pulmão/metabolismo , Masculino , Camundongos , Análise de Sequência com Séries de Oligonucleotídeos , Regulação para Cima/efeitos dos fármacos , Via de Sinalização Wnt/efeitos dos fármacosRESUMO
Mouse models of bacterial sepsis are widely used in research to investigate the underlying molecular mechanisms of sepsis and to develop clinically useful therapeutic regimens. Three commonly used mouse sepsis models include (a) injection of bacterial endotoxin, (b) infusion of cultured bacteria, and (c) cecal ligation and puncture. Here we describe the induction of bacterial sepsis in mice by intraperitoneal injection of cultured live Escherichia coli cells. The severity of the sepsis can be regulated by the number of E. coli cells injected into the peritoneal cavity of mice.
Assuntos
Escherichia coli/crescimento & desenvolvimento , Sepse/microbiologia , Animais , Ceco/microbiologia , Modelos Animais de Doenças , Endotoxinas/administração & dosagem , Injeções Intraperitoneais/métodos , Ligadura/métodos , Camundongos , Camundongos Endogâmicos C57BL , Cavidade Peritoneal/microbiologia , Punções/métodosRESUMO
BACKGROUND: Dysregulation of coagulation occurs commonly in sepsis, ranging from mild coagulopathy with decreased platelets to disseminated intravascular coagulation (DIC). We investigated the effect of induced normothermia on coagulation during lipopolysaccharide (LPS)-induced endotoxaemia in healthy volunteers. METHODS: Twelve volunteers received an infusion of bacterial lipopolysaccharide (Escherichia coli; 2 ng kg-1) and were assigned to either induced normothermia or control. Induced normothermia to maintain core temperature at 37°C consisted of external surface cooling, cold i.v. fluids, and medication to reduce shivering (buspirone, clonidine, and magnesium sulphate). The primary outcome was the DIC score (International Society on Thrombosis and Haemostasis guideline). Prothrombin time (PT), activated partial thromboplastin time (aPTT), D-dimer, plasma von Willebrand factor (vWf), and rotational thromboelastometry (ROTEM) were measured before and 1, 3, 6, and 8 h after LPS infusion. Differences between groups were tested with a mixed effects model. RESULTS: In control subjects, lipopolysaccharide caused a fever, transiently decreased platelet levels and lowered activated partial thromboplastin time, while prolonging prothrombin time and increasing D-Dimer and vWf levels. Normothermia prevented the DIC-score exceeding 4, which occurred in 50% of control subjects. Normothermia also reduced the fall in platelet count by 67x109 L-1([95%CI:27-107]; p=0.002), aPTT (mean difference:3s [95%CI:1-5]; p=0.005) and lowered vWf levels by 89% ([95%CI:6-172]; p=0.03), compared to the fever group. ROTEM measurements were unaffected by lipopolysaccharide. CONCLUSION: In human endotoxaemia, induced normothermia decreases markers of endothelial activation and DIC. Maintaining normothermia may reduce coagulopathy in hyperinflammatory states.
Assuntos
Coagulação Sanguínea , Coagulação Intravascular Disseminada/prevenção & controle , Endotoxemia/terapia , Hipotermia Induzida , Adolescente , Adulto , Biomarcadores/sangue , Testes de Coagulação Sanguínea , Estudos de Casos e Controles , Coagulação Intravascular Disseminada/sangue , Coagulação Intravascular Disseminada/diagnóstico , Coagulação Intravascular Disseminada/etiologia , Endotoxemia/sangue , Endotoxemia/induzido quimicamente , Endotoxemia/diagnóstico , Endotoxinas/administração & dosagem , Voluntários Saudáveis , Humanos , Hipotermia Induzida/efeitos adversos , Infusões Parenterais , Masculino , Fatores de Tempo , Adulto JovemRESUMO
Animals that are competent reservoirs of zoonotic pathogens commonly suffer little morbidity from the infections. To investigate mechanisms of this tolerance of infection, we used single-dose lipopolysaccharide (LPS) as an experimental model of inflammation and compared the responses of two rodents: Peromyscus leucopus, the white-footed deermouse and reservoir for the agents of Lyme disease and other zoonoses, and the house mouse Mus musculus Four hours after injection with LPS or saline, blood, spleen, and liver samples were collected and subjected to transcriptome sequencing (RNA-seq), metabolomics, and specific reverse transcriptase quantitative PCR (RT-qPCR). Differential expression analysis was at the gene, pathway, and network levels. LPS-treated deermice showed signs of sickness similar to those of exposed mice and had similar increases in corticosterone levels and expression of interleukin 6 (IL-6), tumor necrosis factor, IL-1ß, and C-reactive protein. By network analysis, the M. musculus response to LPS was characterized as cytokine associated, while the P. leucopus response was dominated by neutrophil activity terms. In addition, dichotomies in the expression levels of arginase 1 and nitric oxide synthase 2 and of IL-10 and IL-12 were consistent with type M1 macrophage responses in mice and type M2 responses in deermice. Analysis of metabolites in plasma and RNA in organs revealed species differences in tryptophan metabolism. Two genes in particular signified the different phenotypes of deermice and mice: the Slpi and Ibsp genes. Key RNA-seq findings for P. leucopus were replicated in older animals, in a systemic bacterial infection, and with cultivated fibroblasts. The findings indicate that P. leucopus possesses several adaptive traits to moderate inflammation in its balancing of infection resistance and tolerance.IMPORTANCE Animals that are natural carriers of pathogens that cause human diseases commonly manifest little or no sickness as a consequence of infection. Examples include the deermouse, Peromyscus leucopus, which is a reservoir for Lyme disease and several other disease agents in North America, and some types of bats, which are carriers of viruses with pathogenicity for humans. Mechanisms of this phenomenon of infection tolerance and entailed trade-off costs are poorly understood. Using a single injection of lipopolysaccharide (LPS) endotoxin as a proxy for infection, we found that deermice differed from the mouse (Mus musculus) in responses to LPS in several diverse pathways, including innate immunity, oxidative stress, and metabolism. Features distinguishing the deermice cumulatively would moderate downstream ill effects of LPS. Insights gained from the P. leucopus model in the laboratory have implications for studying infection tolerance in other important reservoir species, including bats and other types of wildlife.
Assuntos
Reservatórios de Doenças/microbiologia , Endotoxinas/administração & dosagem , Inflamação/genética , Peromyscus/microbiologia , Zoonoses/imunologia , Zoonoses/microbiologia , Animais , Suscetibilidade a Doenças/etiologia , Suscetibilidade a Doenças/imunologia , Endotoxinas/imunologia , Feminino , Perfilação da Expressão Gênica , Inflamação/imunologia , Doença de Lyme/microbiologia , Masculino , Metabolômica , Camundongos , Camundongos Endogâmicos BALB C , Peromyscus/imunologia , Análise de Sequência de RNARESUMO
The insecticidal Bacillus thuringiensis protein Cry1Ac is produced as a protoxin and becomes activated to a toxin when ingested by larvae. Both proteins are immunogenic and able to activate macrophages. The proposed mechanism of immunostimulation by Cry1Ac protoxin has been related to its capacity to activate antigen-presenting cells (APC), but its ability to activate dendritic cells (DC) has not been explored. Here we evaluated, in the popliteal lymph nodes (PLN), spleen and peritoneum, the activation of DC CD11c+ MHC-II+ following injection with single doses (50 µg) of Cry1Ac toxin or protoxin via the intradermal (i.d.) and intraperitoneal (i.p.) routes in C57BL/6 mice. In vivo stimulation with both Cry1Ac proteins induced activation of DC via upregulation of CD86, primarily in PLN 24 h after i. d. injection. Moreover, this activation was detected in DC, displaying CD103+, a typical marker of migratory DC, while upregulation of CD80 was uniquely induced by toxin. Tracking experiments showed that Cy5-labeled Cry1Ac proteins could rapidly reach the PLN and localize near DC, but some label remained in the footpad. When the capacity of Cry1Ac-activated DC to induce antigen presentation was examined, significant proliferation of naïve T lymphocytes was induced exclusively by the protoxin. The protoxin elicited a Th17-biased cytokine profile. Moreover, only the Cry1Ac toxin induced a pronounced proliferation of B cells from both untreated and Cry1Ac-injected mice, suggesting that it acts as a polyclonal activator. In conclusion, Cry1Ac protoxin and toxin show a distinctive capacity to activate APCs.
Assuntos
Linfócitos B/imunologia , Toxinas de Bacillus thuringiensis/imunologia , Bacillus thuringiensis/imunologia , Células Dendríticas/imunologia , Endotoxinas/imunologia , Proteínas Hemolisinas/imunologia , Animais , Apresentação de Antígeno , Linfócitos B/metabolismo , Toxinas de Bacillus thuringiensis/administração & dosagem , Células Dendríticas/metabolismo , Endotoxinas/administração & dosagem , Feminino , Proteínas Hemolisinas/administração & dosagem , Ativação Linfocitária , Camundongos , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/imunologiaRESUMO
Studies of inflammation in alcohol use disorder (AUD) are overwhelmingly preclinical, and translation to clinical samples is necessary. Endotoxin administration has been used successfully in humans to study mood disorders, offering a translational, reliable and safe model that may be validated in AUD research. We argue for the use of endotoxin challenge to elucidate the interplay between AUD and inflammation.
Assuntos
Alcoolismo/patologia , Inflamação/patologia , Lipopolissacarídeos/administração & dosagem , Pesquisa Biomédica , Endotoxinas/administração & dosagem , Humanos , Pesquisa Translacional BiomédicaRESUMO
Objectives Pregnant women are more susceptible to certain infections; however, this increased susceptibility is not fully understood. Herein, systems biology approaches were utilized to elucidate how pregnancy modulates tissue-specific host responses to a bacterial product, endotoxin. Methods Pregnant and non-pregnant mice were injected with endotoxin or saline on 16.5 days post coitum (n=8-11 per group). The uterus, cervix, liver, adrenal gland, kidney, lung, and brain were collected 12 h after injection and transcriptomes were measured using microarrays. Heatmaps and principal component analysis were used for visualization. Differentially expressed genes between groups were assessed using linear models that included interaction terms to determine whether the effect of infection differed with pregnancy status. Pathway analysis was conducted to interpret gene expression changes. Results We report herein a multi-organ atlas of the transcript perturbations in pregnant and non-pregnant mice in response to endotoxin. Pregnancy strongly modified the host responses to endotoxin in the uterus, cervix, and liver. In contrast, pregnancy had a milder effect on the host response to endotoxin in the adrenal gland, lung, and kidney. However, pregnancy did not drastically affect the host response to endotoxin in the brain. Conclusions Pregnancy imprints organ-specific host immune responses upon endotoxin exposure. These findings provide insight into the host-response against microbes during pregnancy.
Assuntos
Endotoxinas , Imunidade/fisiologia , Complicações Infecciosas na Gravidez , Nascimento Prematuro/imunologia , Transdução de Sinais/imunologia , Glândulas Suprarrenais/imunologia , Animais , Animais Recém-Nascidos , Corioamnionite/imunologia , Endotoxinas/administração & dosagem , Endotoxinas/imunologia , Feminino , Expressão Gênica/imunologia , Perfilação da Expressão Gênica/métodos , Inflamação/imunologia , Rim/imunologia , Pulmão/imunologia , Camundongos , Gravidez , Complicações Infecciosas na Gravidez/imunologia , Complicações Infecciosas na Gravidez/microbiologiaRESUMO
The objective of this study was to examine whether serum iron (Fe) concentration is useful as a prognostic biomarker for cows with acute coliform mastitis (ACM). Our study was composed of determining the reproducibility of serum Fe concentration as a prognostic criterion in cows with ACM (Study 1) and clarifying the sequential changes in serum Fe concentration in cattle that received endotoxin (Study 2). Seventy-seven cows with (n = 47) or without (n = 30) ACM were enrolled in Study 1. The proposed diagnostic cut-off value of serum Fe concentration indicating a poor prognosis of ACM based on the analysis of the receiver operating characteristic curves was < 31.5 µg/dL. Ten young cattle aged 176.8 ± 23.7 days were enrolled in Study 2. Five young cattle received endotoxin (LPS group) and the remaining five received physiological saline (control group). Blood collections were carried out before endotoxin challenge (pre), and 0.5, 1, 2, 4, 8, 12, 24, and 48 h after the challenge. As a result, a significant decrease in serum Fe concentration was not observed until 24 h after endotoxin challenge. Because in cows with clinical ACM it is difficult to know the time course after infection, the alteration in serum Fe concentrations alone may be an insufficient prognostic criterion.
Assuntos
Endotoxemia/veterinária , Infecções por Escherichia coli/veterinária , Ferro/sangue , Infecções por Klebsiella/veterinária , Mastite Bovina/diagnóstico , Doença Aguda , Animais , Biomarcadores/sangue , Bovinos , Endotoxemia/diagnóstico , Endotoxemia/microbiologia , Endotoxinas/administração & dosagem , Escherichia coli/fisiologia , Infecções por Escherichia coli/complicações , Infecções por Escherichia coli/diagnóstico , Infecções por Escherichia coli/microbiologia , Feminino , Infecções por Klebsiella/complicações , Infecções por Klebsiella/diagnóstico , Infecções por Klebsiella/microbiologia , Klebsiella pneumoniae/fisiologia , Mastite Bovina/microbiologia , Prognóstico , Reprodutibilidade dos TestesRESUMO
Objective: Interleukin (IL)-33 has been attracting more and more attention as a new member of theIL-1 cytokine family in recent years. However, the underlying mechanisms referred to the regulation of endogenous IL-33 production are not fully illustrated. Paeoniflorin (PF) has been reported to possess multiple pharmacological activities, including anti-inflammation and anti-allergy. In this study, we aimed to investigate the effect of PF on IL-33 production by macrophages and explore the underlying mechanisms.Methods: In vivo, IL-33 production in mice after lipopolysaccharide (LPS) injection together with PF application was detected by enzyme-linked immunosorbent assay (ELISA). In vitro, MTT, Real-time PCR, ELISA, Calcium (Ca2+) imaging and Western blot were used to assess the cytotoxicity of PF, IL-33 expression at mRNA and protein levels, Ca2+ influx, protein kinase C (PKC) activity, nuclear factor-kappa B (NF-κB), and mitogen-activated protein kinase (MAPK) activation in LPS-stimulated RAW264.7 macrophages with PF administration.Results: Our results indicated that PF (5 and 25 mg/kg) significantly reduced the production of TNF-a, IL-1ß, and IL-33 in the peritoneal exudate of LPS-treated mice. In vitro assay, upregulation of PF concentration (≥ 20 µM) showed an increased cytotoxicity in RAW264.7 cells during the 24-h cell culture. PF (10 µM) inhibited IL-33 production, Ca2+ influx, PKC activity, NF-κB (p65) activation, and P38MAPK phosphorylation in LPS-treated macrophages. Notably, NF-κB inhibitor (BAY 11-7085), P38MAPK inhibitor (SB203580), and Ca2+ blocker (NiCl2) also curbed LPS-induced IL-33 production, respectively.Conclusions: PF suppresses IL-33 production by macrophages via inhibiting NF-κB and P38MAPK activation associated with the regulation of Ca2+ mobilization.
Assuntos
Glucosídeos/farmacologia , Interleucina-33/antagonistas & inibidores , Monoterpenos/farmacologia , Animais , Líquido Ascítico/imunologia , Cálcio/metabolismo , Técnicas de Cultura de Células , Relação Dose-Resposta a Droga , Endotoxinas/administração & dosagem , Endotoxinas/imunologia , Injeções Intraperitoneais , Interleucina-33/biossíntese , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Proteína Quinase C/metabolismo , Células RAW 264.7 , Reação em Cadeia da Polimerase em Tempo RealRESUMO
There is limited information on the effects of stress and/or physiological manipulation on plasma concentrations of corticosterone (CORT) in turkeys. Under basal conditions, there was evidence for episodic release of CORT in turkeys. The present studies determine the effects of handling, herding, herding, the administration of Escherichia coli endotoxin, and challenge with turkey adrenocorticotropic hormone (ACTH) on plasma concentrations of CORT in market-weight male turkeys. Plasma concentrations of CORT were increased after challenge with turkey ACTH, handling together with saline injection or herding (moving birds from one pen to another). There were no effects on plasma concentrations of CORT of the following putative stressors: handling per se, endotoxin challenge, or of placing in an inverted position on simulated shackles.
Assuntos
Hormônio Adrenocorticotrópico/metabolismo , Corticosterona/sangue , Endotoxinas/efeitos adversos , Perus/fisiologia , Hormônio Adrenocorticotrópico/administração & dosagem , Animais , Endotoxinas/administração & dosagem , Masculino , Perus/sangueRESUMO
Safety assessment of genetically modified plants includes protein characterization to confirm the intended trait protein expression. In addition, to conduct safety tests, the large amount of purified protein needed is usually met through the use of a surrogate, microbially produced protein source. Characterization of the eCry3.1Ab and mCry3A proteins as derived from Event MZIR098 maize was challenging because of the difficulty in purifying/isolating these proteins that are of similar molecular weight and have considerable shared sequence and immunogenicity. This also applies to establishing the biochemical equivalence to the microbially produced surrogate proteins, as highly-purified plant protein is required. While use of crude plant extracts facilitated functional equivalence testing with the surrogate proteins, a separate technical challenge had to be met. The eCry3.1Ab and mCry3A proteins display differentiated modes of action toward CRW pests, however, with the same overall target pest spectrum, no differential test organism existed to allow equivalence testing for one insecticidal protein in the presence of the other. To establish that the microbially produced proteins are suitable surrogates for the plant-produced proteins, the challenges in the protein purification and bioactivity testing had to be addressed. This article describes technical solutions to assess and characterize the insecticidal proteins in this new event and thereby confirm equivalence/suitability of the microbially produced protein surrogates.
Assuntos
Toxinas de Bacillus thuringiensis/administração & dosagem , Bacillus thuringiensis/metabolismo , Besouros/efeitos dos fármacos , Endotoxinas/administração & dosagem , Proteínas Hemolisinas/administração & dosagem , Plantas Geneticamente Modificadas/metabolismo , Zea mays/metabolismo , Sequência de Aminoácidos , Animais , Bacillus thuringiensis/genética , Toxinas de Bacillus thuringiensis/metabolismo , Endotoxinas/metabolismo , Glicosilação , Proteínas Hemolisinas/metabolismo , Plantas Geneticamente Modificadas/genética , Zea mays/genéticaRESUMO
The insecticidal Cry toxins produced by Bacillus thuringiensis (Bt) are powerful tools for insect control. Cry toxin receptors such as cadherin (CAD), ABCC2 transporter and alkaline phosphatase (ALP), located on insect midgut cells, are needed for Cry toxicity. Although insect cell lines are useful experimental models for elucidating toxin action mechanism, most of them show low expression of Cry-receptors genes. The GATA transcription factor family plays important roles in regulating development and differentiation of intestine stem cells. Here, we investigated whether GATAs transcription factors are involved in the expression of Cry1Ac-receptors genes, using multiple insect cell lines. Four GATA genes were identified in the transcriptome of the midgut tissue from the lepidopteran larvae Helicoverpa armigera. These HaGATA genes were transiently expressed in three lepidopteran cell lines, Spodoptera frugiperda Sf9, H. armigera QB-Ha-E5 and Trichoplusia ni Hi5. Analysis of transcription activity using transcriptional gene-fusions showed that only H. armigera GATAe (HaGATAe) significantly increased the transcription of CAD, ABCC2 and ALP receptors genes in all insect cell lines. Key DNA regions for HaGATAe regulation were identified in the promoter sequence of these Cry-receptors genes by using promoter deletion mapping. The transient expression of HaGATAe in these cell lines, conferred sensitivity to Cry1Ac toxin, although in Hi5 cells the susceptibility to Cry1Ac was lower than in other two cell lines. High sensitivity to Cry1Ac correlated with simultaneous transcription of ABCC2 and CAD genes in Sf9 and QB-Ha-E5 cells. Our results reveal that HaGATAe enhances transcription of several lepidopteran Cry1Ac receptor genes in cultured insect cells.
Assuntos
Proteínas de Bactérias/administração & dosagem , Endotoxinas/administração & dosagem , Fatores de Transcrição GATA/genética , Regulação da Expressão Gênica , Proteínas Hemolisinas/administração & dosagem , Proteínas de Insetos/genética , Resistência a Inseticidas/genética , Mariposas/genética , Receptores de Superfície Celular/genética , Animais , Bacillus thuringiensis/química , Toxinas de Bacillus thuringiensis , Linhagem Celular , Fatores de Transcrição GATA/metabolismo , Proteínas de Insetos/metabolismo , Mariposas/efeitos dos fármacos , Mariposas/metabolismo , Receptores de Superfície Celular/metabolismo , Células Sf9 , Spodoptera/efeitos dos fármacos , Spodoptera/genética , Spodoptera/metabolismoRESUMO
BACKGROUND: Endotoxin is a component of particulate matter linked to respiratory disease. Our group has shown that experimental endotoxin inhalation challenge reproducibly triggers neutrophilic inflammation in the airways and in peripheral blood. Sputum induction is currently the only available method for assessing airway neutrophilia but is laborious and time-consuming. This analysis examined the correlation between systemic and airway inflammatory responses to endotoxin to determine if peripheral blood could serve as a surrogate marker for neutrophilic airway inflammation. METHODS: We conducted a retrospective study of 124 inhaled endotoxin challenges conducted at our center using 20,000 endotoxin units (EU) of Clinical Center Reference Endotoxin (CCRE). Venipuncture and induced sputum samples were obtained at baseline and 6 hours after completion of endotoxin challenge. The relationship between change in sputum neutrophils (post-challenge - baseline) and change in peripheral blood neutrophils (post-challenge - baseline) was assessed using Spearman's correlation analyses. RESULTS: Inhaled endotoxin induced a significant increase in mean sputum percent neutrophils and peripheral blood absolute neutrophil counts in healthy adults with or without mild asthma, but no significant correlation was found between airway and systemic neutrophilia (r = 0.13, p = 0.18). Stratification by degree of airway neutrophil response and by atopic or asthmatic status did not change the results. CONCLUSIONS: Inhalation challenge with endotoxin safely and effectively induces airway neutrophilic inflammation in most individuals. Increases in endotoxin-induced peripheral blood neutrophils do not correlate well with airway responses and should not be used as a surrogate marker of airway inflammation.
Assuntos
Endotoxinas/administração & dosagem , Mediadores da Inflamação/sangue , Neutrófilos/metabolismo , Escarro/metabolismo , Síndrome de Resposta Inflamatória Sistêmica/sangue , Síndrome de Resposta Inflamatória Sistêmica/induzido quimicamente , Administração por Inalação , Adulto , Endotoxinas/efeitos adversos , Feminino , Humanos , Mediadores da Inflamação/análise , Masculino , Pessoa de Meia-Idade , Neutrófilos/química , Estudos Retrospectivos , Escarro/química , Adulto JovemRESUMO
Circulating serotonin (5-hydroxytryptamine; 5-HT) appears to be associated with various energetic disorders and hypocalcemia during the transition period. The objective of this study was to evaluate the effects of ketosis, feed restriction (FR), and endotoxin challenge (models in which energetic and calcium metabolism are markedly altered) on circulating 5-HT in lactating Holstein cows. Blood samples were obtained from 3 separate experiments; circulating ß-hydroxybutyrate (BHB), nonesterified fatty acids (NEFA), and glucose were measured in all 3 experiments, whereas ionized calcium (iCa2+) was measured only in the endotoxin challenge. In the ketosis study, blood samples from cows clinically diagnosed with ketosis (n = 9) or classified as healthy (n = 9) were obtained from a commercial dairy farm at d -7, 3, and 7 relative to calving. Ketosis was diagnosed using a urine-based test starting at 5 d in milk. There was no effect of health status on circulating 5-HT and no association between 5-HT and BHB, NEFA, or glucose; however, 5-HT concentrations progressively decreased following calving. In the FR experiment, mid-lactation cows were either fed ad libitum (n = 3) or restricted to 20% of their ad libitum intake (n = 5) for 5 d. There were no FR effects on circulating 5-HT, nor was FR correlated with energetic metabolites. In the immune activation model, mid-lactation cows were intravenously challenged with either lipopolysaccharide (LPS; 1.5 µg/kg of BW; n = 6) or sterile saline (control; n = 6). Administering LPS decreased (56%) blood iCa2+ but had no effect on circulating 5-HT, nor was there a correlation between circulating 5-HT and NEFA, BHB, or iCa2+. Circulating 5-HT tended to be positively correlated (r = 0.54) with glucose in Holstein cows administered LPS. In summary, in contrast to expectations, circulating 5-HT was unaffected in models of severely disturbed energetic and Ca2+ homeostasis.
Assuntos
Ácido 3-Hidroxibutírico/sangue , Cálcio da Dieta/sangue , Doenças dos Bovinos/sangue , Ácidos Graxos não Esterificados/sangue , Cetose/veterinária , Serotonina/sangue , Animais , Glicemia/análise , Bovinos , Doenças dos Bovinos/metabolismo , Ingestão de Alimentos , Endotoxinas/administração & dosagem , Metabolismo Energético , Feminino , Homeostase , Cetose/sangue , Cetose/diagnóstico , Cetose/metabolismo , Lactação , Lipopolissacarídeos/metabolismoRESUMO
Strongyloidiasis, caused by Strongyloides stercoralis infection, is an important neglected tropical disease that causes significant public health problems in the tropics and subtropics. The disease can persist in hosts for decades and may be life-threatening because of hyperinfection and dissemination. Ivermectin (mostly) and albendazole are the most common anthelmintics used for treatment. Albendazole is suboptimal for this parasite, and although ivermectin is quite effective in immunocompromised patients, a multiple-course regimen is required. Furthermore, reliance on a single drug class for treating intestinal nematodes is a recipe for future failure. Therefore, it is important to discover new anthelmintics to treat or prevent human strongyloidiasis. One promising candidate is the Bacillus thuringiensis crystal protein Cry5B. Cry5B is highly potent against parasitic nematodes, for example, hookworms and Ascaris suum. Here, we investigated the potential of Cry5B against S. stercoralis. Multiple stages of S. stercoralis, including the first larval stage (L1s), infective stage (iL3s), free-living adult stage, and parasitic female stage, were all susceptible to Cry5B as indicated by impairment of motility and decreased viability in vitro. In summary, Cry5B demonstrated strong potential as an effective anthelmintic for treatment and transmission control of human strongyloidiasis, justifying further experiments to investigate in vivo therapeutic efficacy.
Assuntos
Proteínas de Bactérias/farmacologia , Endotoxinas/farmacologia , Proteínas Hemolisinas/farmacologia , Strongyloides stercoralis/efeitos dos fármacos , Albendazol/farmacologia , Animais , Anti-Helmínticos/administração & dosagem , Anti-Helmínticos/farmacologia , Toxinas de Bacillus thuringiensis , Proteínas de Bactérias/administração & dosagem , Relação Dose-Resposta a Droga , Endotoxinas/administração & dosagem , Escherichia coli/classificação , Escherichia coli/metabolismo , Feminino , Proteínas Hemolisinas/administração & dosagem , Ivermectina/farmacologia , Larva/efeitos dos fármacos , Proteínas Recombinantes/farmacologiaRESUMO
Parasporal inclusions of a native non haemolytic Bacillus thuringiensis strain KAU 59 was screened for its cytotoxicity against human lymphocytic leukemic cell line jurkat and normal human lymphocytes. The cytotoxicity of proteinase activated and non activated solubilised parasporal inclusions against both cell lines was assessed by Cell Titer 96 Aqueous Non Radioactive Cell Proliferation Assay Kit using MTS. The 50 per cent effective concentration (EC50) values were deduced from log probit analysis at 48 h. Morphological changes associated with cytotoxicity were evaluated and molecular mechanisms of cell death were elucidated by TUNEL assay at 48 h post-inoculation. The fluorescence assisted cell sorting was done in the flow cytometer to assess the stage of cell cycle arrest. Relative quantification of caspase-3 expression in Jurkat cells treated with parasporal inclusion protein of KAU 59 was done by qRTPCR The results indicated that the protein was cytotoxic to jurkat cells at the same time non toxic to normal lymphocytes. Cytotoxicity was evident only after proteolytic activation. Apoptotic cell death was confirmed in the protein treated cells by TUNEL Assay and also up regulated caspase-3 gene expression (P < 0.001). S phase cell cycle arrest was confirmed by and fluorescence associated cell sorting.