RESUMO
BACKGROUND: Sexual harassment (SH) in the workplace is prevalent and associated with poor health. Universities are large workplaces with complex formal and informal power relations, which may influence the prevalence of SH. Although employees and students share the university context, few studies on SH have included both groups. The overall aim of the study was to investigate SH among employees and students at a large Swedish public university regarding types of harassment, prevalence in different groups, characteristics of the perpetrators, and the circumstances in which it occurs. METHODS: A cross-sectional analysis was performed, based on a web-based survey with 120 items that was sent out to all staff, including PhD students (N = 8,238) and students (N = 30,244) in November 2019. The response rate was 33% for staff and 32% for students. Exposure to SH was defined as having experienced at least one of ten defined SH behaviors during their work or studies. RESULTS: Among women, 24.5% of staff and 26.8% of students reported having been exposed to SH. The corresponding figures were 7.0% and 11.3% for male staff and students and 33.3% and 29.4% for non-binary individuals among staff and students. Unwelcome comments, suggestive looks or gestures, and 'inadvertent' brushing or touching were the three most common forms of reported harassment, both among staff and students. Attempted or completed rape had been experienced by 2.1% of female and 0.6% of male students. Male and female perpetrators were reported by about 80% and 15%, respectively, of exposed participants. Among staff most reported events occurred during the everyday operation of the university, while among students the majority of the events took place during social events linked to student life. When exposed to a perpetrator from the same group (staff or students), women reported more often being in a subordinate power position in relation to the perpetrator. CONCLUSIONS: The results indicate that sexual harassment is common in the university context, and interventions and case management routines of events should consider power relations between victim and perpetrator, as well as the various contexts within which sexual harassment takes place.
Assuntos
Assédio Sexual , Feminino , Masculino , Humanos , Universidades , Estudos Transversais , Prevalência , Suécia/epidemiologia , EstudantesRESUMO
BACKGROUND: Oral anticoagulation is the mainstay of stroke prevention in atrial fibrillation (AF), but must be balanced against the associated bleeding risk. Several risk scores have been proposed for prediction of bleeding events in patients with AF. OBJECTIVES: To compare the performance of contemporary clinical bleeding risk scores in 18 113 patients with AF randomized to dabigatran 110 mg, 150 mg or warfarin in the RE-LY trial. METHODS: HAS-BLED, ORBIT, ATRIA and HEMORR2 HAGES bleeding risk scores were calculated based on clinical information at baseline. All major bleeding events were centrally adjudicated. RESULTS: There were 1182 (6.5%) major bleeding events during a median follow-up of 2.0 years. For all the four schemes, high-risk subgroups had higher risk of major bleeding (all P < 0.001). The ORBIT score showed the best discrimination with c-indices of 0.66, 0.66 and 0.62, respectively, for major, life-threatening and intracranial bleeding, which were significantly better than for the HAS-BLED score (difference in c-indices: 0.050, 0.053 and 0.048, respectively, all P < 0.05). The ORBIT score also showed the best calibration compared with previous data. Significant treatment interactions between the bleeding scores and the risk of major bleeding with dabigatran 150 mg BD versus warfarin were found for the ORBIT (P = 0.0019), ATRIA (P < 0.001) and HEMORR2 HAGES (P < 0.001) scores. HAS-BLED score showed a nonsignificant trend for interaction (P = 0.0607). CONCLUSIONS: Amongst the current clinical bleeding risk scores, the ORBIT score demonstrated the best discrimination and calibration. All the scores demonstrated, to a variable extent, an interaction with bleeding risk associated with dabigatran or warfarin.
Assuntos
Fibrilação Atrial/tratamento farmacológico , Dabigatrana/efeitos adversos , Hemorragia/induzido quimicamente , Medição de Risco/métodos , Acidente Vascular Cerebral/prevenção & controle , Varfarina/efeitos adversos , Idoso , Idoso de 80 Anos ou mais , Anticoagulantes/efeitos adversos , Anticoagulantes/uso terapêutico , Antitrombinas/efeitos adversos , Antitrombinas/uso terapêutico , Fibrilação Atrial/complicações , Dabigatrana/uso terapêutico , Relação Dose-Resposta a Droga , Feminino , Seguimentos , Saúde Global , Hemorragia/epidemiologia , Humanos , Incidência , Masculino , Acidente Vascular Cerebral/etiologia , Fatores de Tempo , Varfarina/uso terapêuticoRESUMO
BACKGROUND: Extra-corpuscular haemoglobin is an endogenous factor enhancing inflammatory tissue damage, a process counteracted by the haemoglobin-binding plasma protein haptoglobin composed of alpha and beta subunits connected by disulfide bridges. Recent studies established that haptoglobin also binds and sequesters another pro-inflammatory mediator, HMGB1, via triggering CD163 receptor-mediated anti-inflammatory responses involving heme oxygenase-1 expression and IL-10 release. The molecular mechanism underlying haptoglobin-HMGB1 interaction remains poorly elucidated. METHODS: Haptoglobin ß subunits were tested for HMGB1-binding properties, as well as efficacy in animal models of sterile liver injury (induced by intraperitoneal acetaminophen administration) or infectious peritonitis (induced by cecal ligation and puncture, CLP, surgery) using wild-type (C57BL/6) or haptoglobin gene-deficient mice. RESULTS: Structural-functional analysis demonstrated that the haptoglobin ß subunit recapitulates the HMGB1-binding properties of full-length haptoglobin. Similar to HMGB1-haptoglobin complexes, the HMGB1-haptoglobin ß complexes also elicited anti-inflammatory effects via CD163-mediated IL-10 release and heme oxygenase-1 expression. Treatment with haptoglobin ß protein conferred significant protection in mouse models of polymicrobial sepsis as well as acetaminophen-induced liver injury, two HMGB1-dependent inflammatory conditions. CONCLUSIONS: Haptoglobin ß protein offers a novel therapeutic approach to fight against various inflammatory diseases caused by excessive HMGB1 release.
Assuntos
Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Proteína HMGB1/metabolismo , Haptoglobinas/metabolismo , Sepse/metabolismo , Animais , Antígenos CD/metabolismo , Antígenos de Diferenciação Mielomonocítica/metabolismo , Células Cultivadas , Doença Hepática Induzida por Substâncias e Drogas/terapia , Citocinas/metabolismo , Modelos Animais de Doenças , Proteína HMGB1/antagonistas & inibidores , Haptoglobinas/uso terapêutico , Heme Oxigenase-1/biossíntese , Heme Oxigenase-1/metabolismo , Humanos , Interleucina-10/metabolismo , Macrófagos/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Ligação Proteica , Receptores de Superfície Celular/metabolismo , Sepse/terapiaRESUMO
BACKGROUND: More than 500,000 hospitalized patients survive severe sepsis annually in the USA. Recent epidemiological evidence, however, demonstrated that these survivors have significant morbidity and mortality, with 3-year fatality rates higher than 70%. To investigate the mechanisms underlying persistent functional impairment in sepsis survivors, here we developed a model to study severe sepsis survivors following cecal ligation and puncture (CLP). METHODS: Sepsis was induced in mice by CLP and survivors were followed for twelve weeks. Spleen and blood were collected and analyzed at different time points post-sepsis. RESULTS: We observed that sepsis survivors developed significant splenomegaly. Analysis of the splenic cellular compartments revealed a major expansion of the inflammatory CD11b+ Ly-6CHigh pool. Serum high-mobility group box 1 (HMGB1) levels in the sepsis surviving mice were significantly elevated for 4-6 weeks after post-sepsis, and administration of an anti-HMGB1 monoclonal antibody significantly attenuated splenomegaly as well as splenocyte priming. Administration of recombinant HMGB1 to naive mice induced similar splenomegaly, leukocytosis and splenocyte priming as observed in sepsis survivors. Interestingly analysis of circulating HMGB1 from sepsis survivors by mass spectroscopy demonstrated a stepwise increase of reduced form of HMGB1 (with known chemo-attractant properties) during the first 3 weeks, followed by disulphide form (with known inflammatory properties) 4-8 weeks after CLP. DISCUSSION: Our results indicate that prolonged elevation of HMGB1 is a necessary and sufficient mediator of splenomegaly and splenocyte expansion, as well as splenocyte inflammatory priming in murine severe sepsis survivors.
Assuntos
Antígenos Ly/imunologia , Bacteriemia/imunologia , Antígeno CD11b/imunologia , Proteína HMGB1/fisiologia , Monócitos/imunologia , Esplenomegalia/imunologia , Animais , Ceco/lesões , Modelos Animais de Doenças , Humanos , Inflamação/imunologia , Ligadura , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Punções/efeitos adversos , Baço/imunologiaRESUMO
Vascular endothelial growth factor (VEGF) and its receptors (VEGFR) are central components in the development and progression of glioblastoma. To investigate if genetic variation in VEGF and VEGFR2 is associated with glioblastoma prognosis, we examined blood samples from 154 glioblastoma cases collected in Sweden and Denmark between 2000 and 2004. Seventeen tagging single nucleotide polymorphisms (SNPs) in VEGF and 27 in VEGFR2 were genotyped and analysed, covering 90% of the genetic variability within the genes. In VEGF, we found no SNPs associated with survival. In VEGFR2, we found two SNPs significantly associated to survival, namely rs2071559 and rs12502008. However, these results are likely to be false positives due to multiple testing and could not be confirmed in a separate dataset. Overall, this study provides little evidence that VEGF and VEGFR2 polymorphisms are important for glioblastoma survival.
Assuntos
Biomarcadores Tumorais/genética , Neoplasias Encefálicas/genética , Glioblastoma/genética , Polimorfismo de Nucleotídeo Único , Fator A de Crescimento do Endotélio Vascular/genética , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/genética , Adulto , Idoso , Neoplasias Encefálicas/diagnóstico , Feminino , Predisposição Genética para Doença , Genótipo , Glioblastoma/diagnóstico , Humanos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Prognóstico , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Adulto JovemRESUMO
Lipopolysaccharide (LPS) is lethal to animals because it activates cytokine release, causing septic shock and tissue injury. Early proinflammatory cytokines (e.g., tumor necrosis factor [TNF] and interleukin [IL]-1) released within the first few hours of endotoxemia stimulate mediator cascades that persist for days and can lead to death. High mobility group 1 protein (HMG-1), a ubiquitous DNA-binding protein, was recently identified as a "late" mediator of endotoxin lethality. Anti-HMG-1 antibodies neutralized the delayed increase in serum HMG-1, and protected against endotoxin lethality, even when passive immunization was delayed until after the early cytokine response. Here we examined whether HMG-1 might stimulate cytokine synthesis in human peripheral blood mononuclear cell cultures. Addition of purified recombinant HMG-1 to human monocyte cultures significantly stimulated the release of TNF, IL-1alpha, IL-1beta, IL-1RA, IL-6, IL-8, macrophage inflammatory protein (MIP)-1alpha, and MIP-1beta; but not IL-10 or IL-12. HMG-1 concentrations that activated monocytes were within the pathological range previously observed in endotoxemic animals, and in serum obtained from septic patients. HMG-1 failed to stimulate cytokine release in lymphocytes, indicating that cellular stimulation was specific. Cytokine release after HMG-1 stimulation was delayed and biphasic compared with LPS stimulation. Computer-assisted image analysis demonstrated that peak intensity of HMG-1-induced cellular TNF staining was comparable to that observed after maximal stimulation with LPS. Administration of HMG-1 to Balb/c mice significantly increased serum TNF levels in vivo. Together, these results indicate that, like other cytokine mediators of endotoxin lethality (e.g., TNF and IL-1), extracellular HMG-1 is a regulator of monocyte proinflammatory cytokine synthesis.
Assuntos
Proteínas de Transporte/farmacologia , Citocinas/biossíntese , Proteínas de Grupo de Alta Mobilidade/farmacologia , Monócitos/imunologia , Fator de Necrose Tumoral alfa/biossíntese , Animais , Proteínas de Transporte/genética , Células Cultivadas , Quimiocina CCL3 , Quimiocina CCL4 , Ensaio de Imunoadsorção Enzimática , Imunofluorescência , Proteína HMGB1 , Proteínas de Grupo de Alta Mobilidade/genética , Humanos , Interleucina-1/metabolismo , Interleucina-10/metabolismo , Interleucina-12/metabolismo , Interleucina-6/metabolismo , Interleucina-8/metabolismo , Lipopolissacarídeos/farmacologia , Proteínas Inflamatórias de Macrófagos/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Monócitos/efeitos dos fármacos , Monócitos/metabolismo , Fenótipo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Proteínas Recombinantes/farmacologia , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismoRESUMO
AIM: Clinical studies have suggested a role for dietary glycaemic index (GI) in body weight regulation and diabetes risk. Here, we investigated the long-term metabolic effects of low and high glycaemic diets using the C57BL/6J mouse model. METHODS: Female C57BL/6J mice were fed low or high glycaemic starch in either low-fat or medium-fat diets for 22 weeks. Oral and intravenous glucose tolerance tests were performed to investigate the effect of the experimental diets on glucose tolerance and insulin resistance. RESULTS: In this study, a high glycaemic diet resulted in impaired oral glucose tolerance compared to a low glycaemic diet. This effect was more pronounced in the group fed a medium-fat diet, suggesting that a lower dietary fat content ameliorates the negative effect of a high glycaemic diet. No effect on body weight or body fat content was observed in either a low-fat diet or a medium-fat diet. Static incubation of isolated islets did not show any differences in basal (3.3 mM glucose) or glucose-stimulated (8.6 and 16.7 mM glucose) insulin secretion between mice fed a low or high glycaemic diet. CONCLUSION: Together, our data suggest that the impaired glucose tolerance seen after a high glycaemic diet is not explained by altered ß-cell function.
Assuntos
Dieta para Diabéticos , Resistência à Insulina/fisiologia , Células Secretoras de Insulina/metabolismo , Insulina/metabolismo , Animais , Peso Corporal/fisiologia , Dieta com Restrição de Gorduras , Feminino , Teste de Tolerância a Glucose/métodos , Índice Glicêmico , Secreção de Insulina , Camundongos , Camundongos Endogâmicos C57BLRESUMO
Endotoxin, a constituent of Gram-negative bacteria, stimulates macrophages to release large quantities of tumor necrosis factor (TNF) and interleukin-1 (IL-1), which can precipitate tissue injury and lethal shock (endotoxemia). Antagonists of TNF and IL-1 have shown limited efficacy in clinical trials, possibly because these cytokines are early mediators in pathogenesis. Here a potential late mediator of lethality is identified and characterized in a mouse model. High mobility group-1 (HMG-1) protein was found to be released by cultured macrophages more than 8 hours after stimulation with endotoxin, TNF, or IL-1. Mice showed increased serum levels of HMG-1 from 8 to 32 hours after endotoxin exposure. Delayed administration of antibodies to HMG-1 attenuated endotoxin lethality in mice, and administration of HMG-1 itself was lethal. Septic patients who succumbed to infection had increased serum HMG-1 levels, suggesting that this protein warrants investigation as a therapeutic target.
Assuntos
Bacteriemia/sangue , Proteínas de Transporte/metabolismo , Endotoxemia/sangue , Endotoxinas/toxicidade , Proteínas de Grupo de Alta Mobilidade/metabolismo , Macrófagos/metabolismo , Animais , Proteínas de Transporte/genética , Proteínas de Transporte/imunologia , Proteínas de Transporte/toxicidade , Linhagem Celular , Células Cultivadas , Endotoxinas/sangue , Proteína HMGB1 , Proteínas de Grupo de Alta Mobilidade/genética , Proteínas de Grupo de Alta Mobilidade/imunologia , Proteínas de Grupo de Alta Mobilidade/toxicidade , Humanos , Soros Imunes/imunologia , Imunização Passiva , Interferon gama/farmacologia , Interleucina-1/farmacologia , Dose Letal Mediana , Leucócitos Mononucleares/metabolismo , Lipopolissacarídeos/toxicidade , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C3H , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Fatores de Tempo , Fator de Necrose Tumoral alfa/farmacologiaRESUMO
The thermogenic peroxisome proliferator-activated receptor gamma (PPAR-gamma) coactivator 1 (PGC-1) has previously been shown to activate mitochondrial biogenesis in part through a direct interaction with nuclear respiratory factor 1 (NRF-1). In order to identify related coactivators that act through NRF-1, we searched the databases for sequences with similarities to PGC-1. Here, we describe the first characterization of a 177-kDa transcriptional coactivator, designated PGC-1-related coactivator (PRC). PRC is ubiquitously expressed in murine and human tissues and cell lines; but unlike PGC-1, PRC was not dramatically up-regulated during thermogenesis in brown fat. However, its expression was down-regulated in quiescent BALB/3T3 cells and was rapidly induced by reintroduction of serum, conditions where PGC-1 was not detected. PRC activated NRF-1-dependent promoters in a manner similar to that observed for PGC-1. Moreover, NRF-1 was immunoprecipitated from cell extracts by antibodies directed against PRC, and both proteins were colocalized to the nucleoplasm by confocal laser scanning microscopy. PRC interacts in vitro with the NRF-1 DNA binding domain through two distinct recognition motifs that are separated by an unstructured proline-rich region. PRC also contains a potent transcriptional activation domain in its amino terminus adjacent to an LXXLL motif. The spatial arrangement of these functional domains coincides with those found in PGC-1, supporting the conclusion that PRC and PGC-1 are structurally and functionally related. We conclude that PRC is a functional relative of PGC-1 that operates through NRF-1 and possibly other activators in response to proliferative signals.
Assuntos
Proteínas de Ligação a DNA/metabolismo , Transativadores/metabolismo , Fatores de Transcrição/genética , Ativação Transcricional , Células 3T3 , Sequência de Aminoácidos , Animais , Sequência de Bases , Células COS , Chlorocebus aethiops , DNA Complementar , Humanos , Masculino , Mamíferos , Camundongos , Camundongos Endogâmicos BALB C , Dados de Sequência Molecular , Fator 1 Relacionado a NF-E2 , Fator 1 Nuclear Respiratório , Fatores Nucleares Respiratórios , Transativadores/genética , Células Tumorais CultivadasAssuntos
Produtos Biológicos/uso terapêutico , Imunoterapia/métodos , Doença de Alzheimer/terapia , Vacinas Anticâncer/uso terapêutico , Humanos , Interleucina-1beta/antagonistas & inibidores , Interleucina-33 , Interleucinas/antagonistas & inibidores , Lúpus Eritematoso Sistêmico/terapia , Fator de Necrose Tumoral alfa/antagonistas & inibidoresRESUMO
In agreement with previous work, treatment of rats with cholesterol, 2% in diet, stimulated the cholesterol 7 alpha-hydroxylase activity more than 2-fold. With less than 1% in diet, no significant effect was obtained. Intravenous infusion of cholesterol-enriched Intralipid had no stimulatory effect. In accordance with some recent work by other groups, it was shown that the stimulation of the cholesterol 7 alpha-hydroxylase by dietary cholesterol was associated with elevated levels of mRNA corresponding to the enzyme. Most of the stimulation of the activity induced by dietary cholesterol could not be prevented by lymphatic drainage. Feeding lymph fistulated rats with 2% cholesterol in diet stimulated the cholesterol 7 alpha-hydroxylase almost 2-fold, indicating that under the conditions employed, a major part of the cholesterol-induced stimulation of the activity was due to factor(s) unrelated to the flux of cholesterol from the intestine to the liver. There was a good correlation between the amount of cholesterol excreted in faeces and the activity of the cholesterol 7 alpha-hydroxylase. The half-life of intraperitoneally administered labelled cholic acid was significantly shorter in rats treated with 2% cholesterol in diet (t1/2 = 1.2 +/- 0.1 days) than in control rats (t1/2 = 1.9 +/- 0.18 days). A notable finding was that the weight of faeces was considerably higher in rats fed cholesterol than in the controls. It is hypothesized that a high dietary load of cholesterol causes increased binding of bile acids in the intestine and increased loss of bile acids in faeces. This leads to a reduced suppression of the cholesterol 7 alpha-hydroxylase by the bile acids. The results support the contention that the flux of bile acids rather than the flux of cholesterol from the intestine is the major direct regulator of bile acid biosynthesis.
Assuntos
Colesterol 7-alfa-Hidroxilase/efeitos dos fármacos , Colesterol na Dieta/farmacologia , Animais , Ácidos e Sais Biliares/química , Ácidos e Sais Biliares/fisiologia , Transporte Biológico/efeitos dos fármacos , Ativação Enzimática/efeitos dos fármacos , Intestinos/química , Intestinos/fisiologia , Masculino , Microssomos Hepáticos/enzimologia , Ratos , Ratos EndogâmicosRESUMO
Conversion of cholesterol into cholic acid in mammalian liver requires a 12alpha-hydroxylation step. Results have been presented suggesting that two different enzymes are involved in this hydroxylation with different activities towards the two steroids believed to be the physiological substrates for the enzyme, 7alpha-hydroxy-4-cholesten-3-one and 5beta-cholestane-3alpha,7alpha-diol. It is shown here that rabbit liver microsomes and partly purified sterol 12alpha-hydroxylase as well as COS cells transfected with a cDNA coding for this enzyme are able to catalyze 12alpha-hydroxylation of the two substrates at similar relative rates. Also 7alpha-hydroxycholesterol and 3alpha,7alpha-dihydroxy-5beta-cholestanoic acid are 12alpha-hydroxylated by the three systems. It is concluded that rabbit liver contains one major sterol 12alpha-hydroxylase with a broad substrate specificity.
Assuntos
Microssomos Hepáticos/enzimologia , Esteroide 12-alfa-Hidroxilase/metabolismo , Animais , Células COS , Colestanóis/metabolismo , Colestanóis/farmacologia , Colestenonas/metabolismo , Colesterol/análogos & derivados , Colesterol/metabolismo , DNA Complementar/genética , Inibidores Enzimáticos/farmacologia , Feminino , Cromatografia Gasosa-Espectrometria de Massas , Hidroxicolesteróis/metabolismo , Hidroxilação , Coelhos , Esteroide 12-alfa-Hidroxilase/genética , Esteróis/metabolismo , Especificidade por Substrato , Transfecção/genéticaRESUMO
Long chain acyl-CoA thioesterase activity is mainly located in microsomes after subcellular fractionation of liver from untreated rats. The physiological function and regulation of expression of this activity is not known. In the present study we have investigated the effect of thyroxine on expression of carboxylesterase ES-4, the major acyl-CoA thioesterase of liver microsomes. Thyroidectomy of rats decreased the palmitoyl-CoA thioesterase activity to about 25% of normal activity. This decrease was accompanied by similar decreases at the protein and mRNA levels (31% and 57%, respectively, of controls). Treatment with thyroxine completely reversed the effect of thyroidectomy and resulted in elevated levels in both thyroidectomized and control rats. For reasons of comparison we also studied the possibility that ES-10 and ES-2, two other members of the same gene family, are affected by thyroxine. ES-10 was not changed at the protein or mRNA level by any of the treatments, while ES-2 expression in liver was decreased by thyroxine treatment. The data shows that changes in activity and expression of ES-4 correlate to thyroxine status in the rat suggesting a physiological regulatory role by this hormone. Since thyroxine regulates the expression of lipogenic enzymes, these results are consistent with a function for this microsomal acyl-CoA thioesterase in fatty acid synthesis and/or secretion, rather than in oxidative degradation of fatty acids.
Assuntos
Microssomos Hepáticos/enzimologia , Palmitoil-CoA Hidrolase/metabolismo , Tiroxina/farmacologia , Animais , Northern Blotting , Western Blotting , Carboxilesterase , Hidrolases de Éster Carboxílico/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Masculino , Palmitoil-CoA Hidrolase/genética , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley , TireoidectomiaRESUMO
Sterol 12alpha-hydroxylase (CYP 8B1) is a microsomal cytochrome P450 enzyme involved in bile acid synthesis that is of critical importance for the composition of bile acids formed in the liver. Thyroidectomy of rats caused a more than twofold increase of CYP8B1 and an almost fourfold increase of the corresponding mRNA levels compared to sham-operated rats. Treatment of intact rats with thyroxine caused a 60% reduction of enzyme activity and a 50% reduction of mRNA levels compared to rats injected with saline only. To investigate whether the promoter of the gene contains thyroid hormone response elements, the complete structure of the rat gene was defined. In similarity with the corresponding gene in mouse, rabbit and man, the rat gene was found to lack introns. It had an open reading frame containing 1500 bp corresponding to a protein of 499 amino acid residues. Although thyroid hormone decreased CYP8B1 activity and mRNA in vivo, no hitherto described thyroid hormone response elements were identified 1883 bases upstream of the transcription start site. It is concluded that rat CYP8B1 is regulated by thyroid hormone at the mRNA level. The results are discussed in relation to the structure of the gene coding for the enzyme.
Assuntos
Inibidores das Enzimas do Citocromo P-450 , Fígado/efeitos dos fármacos , Esteroide Hidroxilases/antagonistas & inibidores , Tiroxina/farmacologia , Sequência de Aminoácidos , Animais , Sequência de Bases , Células COS , Sistema Enzimático do Citocromo P-450/genética , DNA Complementar/química , DNA Complementar/isolamento & purificação , Expressão Gênica , Fígado/enzimologia , Masculino , Dados de Sequência Molecular , Regiões Promotoras Genéticas , RNA Mensageiro/análise , Ratos , Ratos Sprague-Dawley , Elementos de Resposta , Esteroide 12-alfa-Hidroxilase , Esteroide Hidroxilases/genética , Tireoidectomia , TransfecçãoRESUMO
A technique using a computerized image analysis system was developed for evaluating and quantifying human cytokine production. This system registered single cells as positive or negative cytokine producers based on a specific juxtanuclear staining pattern generated by accumulation of the proteins in the Golgi-endoplasmatic reticulum compartment. The characteristic morphology of the immunocytochemical staining offered the opportunity to register individual producer cells within multicomponent cell populations. A color camera was then adapted to transfer on-line images directly into the computer-controlled operating system. In this study cultured human peripheral blood mononuclear cells were polyclonally stimulated and then analyzed for interleukin-1alpha (IL-1alpha), IL-1beta, IL-1ra, IL-2, IL-4, IL-6, IL-8, IL-10, tumor necrosis factor-alpha (TNF-alpha), TNF-beta, interferon-gamma, granulocyte colony-stimulating factor and granulocyte-macrophage colony-stimulating factor production. The image-analyzing system detected cytokine-producing cells in a sensitive and reproducible manner, which was in total congruence with enumeration by conventional microscopy. Furthermore, accurate assessments of cell distributions by signal intensity and cell area were applied at the single-cell level. The image-analyzing system allowed the detection of at least 1 in 1,000 events by using unique cytokine-associated morphometric criteria. The results of kinetic studies measuring cytokine production following activation and cell transformation provided data supporting increases in intensity of intracellular localized specific immunostaining and in cell size within the cytokine-producing cells.
Assuntos
Citocinas/biossíntese , Processamento de Imagem Assistida por Computador/métodos , Adulto , Contagem de Células , Células Cultivadas , Estudos de Avaliação como Assunto , Humanos , Imuno-Histoquímica , Interleucinas/biossíntese , Ionomicina/farmacologia , Leucócitos Mononucleares/citologia , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/metabolismo , Lipopolissacarídeos/farmacologia , Linfocinas/biossíntese , Microscopia , Monocinas/biossíntese , Estimulação Química , Acetato de Tetradecanoilforbol/farmacologiaRESUMO
Identifying individual cytokine-producing cells may help to acquire insight into immunological processes. This study was designed to adapt a technique for the detection of individual cytokine-producing cells from an immunofluorescence to an immunoperoxidase staining procedure. The production of interferon-gamma (IFN-gamma) by anti-CD3-activated cloned human T cells was used as a model system. After the conditions for the staining procedure were optimized, the immunoperoxidase technique was slightly more sensitive than the immunofluorescence technique. The intracellular staining for IFN-gamma was preceded or paralleled by IFN-gamma mRNA production and followed by accumulation of IFN-gamma in the supernatant. It is concluded that intracellular IFN-gamma can easily be detected using an immunoperoxidase procedure. This procedure is highly sensitive and allows quantification of the production of multiple cytokines by counting the percentage of positively staining cells.
Assuntos
Interferon gama/análise , RNA Mensageiro/análise , Receptores de Interleucina-1/antagonistas & inibidores , Linfócitos T/química , Citocinas/genética , Imunofluorescência , Fator Estimulador de Colônias de Granulócitos e Macrófagos/metabolismo , Humanos , Técnicas Imunoenzimáticas , Interferon gama/genética , Interleucina-1/metabolismo , Interleucina-2/metabolismo , Interleucina-3/metabolismo , Interleucina-4/metabolismo , Interleucina-6/metabolismo , Interleucina-8/metabolismo , Reação em Cadeia da Polimerase , Coloração e Rotulagem , Fator de Necrose Tumoral alfa/metabolismoRESUMO
The atherosclerotic lesion contains large numbers of macrophages and T lymphocytes. This suggests that a cellular immune response may take place in the lesion, and oxidized lipoproteins, heat shock proteins, and micro-organisms have been implied as candidate antigens. However, the effector mechanisms elicited by this response have been largely unclear. We have therefore analyzed endarterectomy specimens by immunohistochemistry and reverse transcription-PCR to detect immune cytokines produced by immunocompetent cells of the advanced human plaque. The pro-inflammatory T cell cytokines, interleukin-2 and interferon-7, were found in a large proportion of plaques (IL-2 in 50% and interferon-gamma in 30% of plaques by immunohistochemistry and mRNA for both cytokines in 70% of plaques by PCR). In contrast, interleukin-4 and interleukin-5 were rarely observed (both cytokines in 10% of plaques by immunohistochemistry, mRNA for interleukin-4 in 10% and for interleukin-5 in 40% by PCR). This demonstrates the presence of a predominantly pro-inflammatory, Th1-type T cell response in atherosclerosis. This conclusion was further supported by the expression of the pro-inflammatory cytokine, interleukin-1 by plaque macrophages and endothelial cells. In addition, the chemokine interleukin-8 and the macrophage differentiation-stimulating cytokine, granulocyte-monocyte colony stimulating factor, were observed in plaque tissues, suggesting that the micro-environment promotes monocyte recruitment and macrophage differentiation. Occasional eosinophils and B cells were, however observed, which is compatible with a microheterogeneity within the lesion. Finally, the anti-inflammatory and fibrogenic cytokines, transforming growth factor-beta1-3 and its carrier protein, latent TGF-beta binding protein, were found in large amounts in all plaques. Together, these results show that a pro-inflammatory, Thl type cellular immune response takes place in the atherosclerotic plaque. The balance between pro-inflammatory and anti-inflammatory cytokines may be decisive for the progression of the lesion.
Assuntos
Arteriosclerose/metabolismo , Citocinas/análise , Mediadores da Inflamação/análise , Arteriosclerose/patologia , Proteínas de Transporte/análise , Humanos , Imuno-Histoquímica , Interferon gama/análise , Interleucinas/análise , Macrófagos/metabolismo , Macrófagos/patologia , Macrófagos/fisiologia , Reação em Cadeia da Polimerase , Células Th1/metabolismo , Células Th1/patologia , Fator de Crescimento Transformador beta/análise , Fator de Necrose Tumoral alfa/análiseRESUMO
An immunofluorescent staining method was developed for detecting human IFN-gamma-producing cells in single cell suspensions. Mononuclear leukocytes, stimulated in vitro to produce IFN-gamma, were fixed and made permeable. The cytoplasmic presence of IFN-gamma was visualized by indirect immunofluorescence using IFN-gamma-specific mouse monoclonal antibodies. The staining was found to be specific for IFN-gamma and allowed the detection of newly synthesized rather than internalized IFN-gamma molecules. The cytoplasmic fluorescence appeared locally in a polar, juxtanuclear position, which overlapped the Golgi apparatus, probably reflecting the glycosylation site of the newly formed IFN-gamma molecules. Two-colour staining experiments showed that the method is useful not only for the detection and enumeration but also for the phenotypic characterization of IFN-gamma-producing cells.