Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 31
Filtrar
1.
Int Immunopharmacol ; 84: 106520, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32325405

RESUMO

Bilirubin, as the final product of heme metabolism, has both toxic and beneficial effects on humans depending on its serum concentration. So far, whether and how physiological concentrations of bilirubin influence inflammation is largely unknown. In the current study, we established inflammatory cell models of murine peritoneal macrophages (PMs) and bone marrow-derived macrophages (BMDMs) by stimulating the cells with either lipopolysaccharide (LPS) alone or with various inflammasome stimuli. In addition, a model of mouse sepsis induced by intraperitoneal injection of LPS was also employed. We found that bilirubin, although used at physiological concentrations, could control inflammation both in vitro and in vivo. In vitro, bilirubin inhibited caspase-1 maturation and IL-1ß secretion in NLRP3, AIM2, and NLRC4 inflammasomes. Besides, bilirubin inhibited the secretion of TNF-α and IL-6 in LPS-primed macrophages by reduced phosphorylation of IκB-α and p65, indicating the inhibition of the NF-κB pathway. In vivo, bilirubin significantly inhibited the release of IL-1ß and TNF-α, resulting in an increased survival rate of mice with LPS-induced sepsis. Our study demonstrates a protective role of physiological concentrations of bilirubin against inflammation, the mechanisms of which involve the inhibition of the NF-κB signaling pathway as well as control of the activation of inflammasomes. Bilirubin could therefore be considered an endogenous regulatory molecule modulating inflammation. In defined doses, bilirubin could be applied as a potential medication against inflammation and inflammasome-related diseases.


Assuntos
Bilirrubina/imunologia , Inflamassomos/imunologia , Inflamação/imunologia , NF-kappa B/imunologia , Animais , Caspase 1/imunologia , Interleucina-1beta/imunologia , Lipopolissacarídeos/imunologia , Macrófagos Peritoneais/imunologia , Masculino , Camundongos Endogâmicos C57BL , Sepse/induzido quimicamente , Sepse/imunologia , Fator de Necrose Tumoral alfa/imunologia
2.
Front Immunol ; 11: 66, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32082323

RESUMO

Heme is one of the most abundant molecules in the body acting as the functional core of hemoglobin/myoglobin involved in the O2/CO2 carrying in the blood and tissues, redox enzymes and cytochromes in mitochondria. However, free heme is toxic and therefore its removal is a significant priority for the host. Heme is a well-established danger-associated molecular pattern (DAMP), which binds to toll-like receptor 4 (TLR4) to induce immune responses. Heme-derived metabolites including the bile pigments, biliverdin (BV) and bilirubin (BR), were first identified as toxic drivers of neonatal jaundice in 1800 but have only recently been appreciated as endogenous drivers of multiple signaling pathways involved in protection from oxidative stress and regulators of immune responses. The tissue concentration of heme, BV and BR is tightly controlled. Heme oxygenase-1 (HO-1, encoded by HMOX1) produces BV by heme degradation, while biliverdin reductase-A (BLVR-A) generates BR by the subsequent conversion of BV. BLVR-A is a fascinating protein that possesses a classical protein kinase domain, which is activated in response to BV binding to its enzymatic site and initiates the downstream mitogen-activated protein kinases (MAPK) and phosphatidylinositol 3-kinase (PI3K) pathways. This links BLVR-A activity to cell growth and survival pathways. BLVR-A also contains a bZip DNA binding domain and a nuclear export sequence (NES) and acts as a transcription factor to regulate the expression of immune modulatory genes. Here we will discuss the role of heme-related immune response and the potential for targeting the heme system for therapies directed toward hepatitis and cancer.


Assuntos
Heme/imunologia , Heme/metabolismo , Imunidade/fisiologia , Inflamação/imunologia , Animais , Bilirrubina/imunologia , Bilirrubina/metabolismo , Biliverdina/imunologia , Biliverdina/metabolismo , Humanos , Inflamação/metabolismo
3.
Curr Med Sci ; 39(5): 719-726, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31612388

RESUMO

Hepatitis E virus (HEV) infection is a major cause of morbidity in endemic areas. Its consequences among chronic hepatitis B (CHB) patients have been under-reported. The aim of this study was to assess the impact of superinfective HEV infection (acute and past) on virological and clinical features of patients with CHB infection. Clinical, biochemical, virological and immunological data of 153 CHB patients including 98 with hepatitis B virus (HBV) monoinfection and 55 with HBV-HEV superinfection with both HEV and HBV infection was retrospectively investigated and analyzed in this study conducted in Wuhan, China. An overall anti-HEV IgG seroprevalence was found to be 35.9% in CHB patients. HBV-HEV superinfection patients showed significantly higher rate of complications (ascites, hepato-renal syndrome & encephalopathy) (all with P=0.04), cirrhosis (P<0.001) and acute-on-chronic liver failure (P<0.001) than HBV monoinfection patients. They also displayed elevated ALTs (P<0.001) and total serum bilirubin (P<0.001) with diminished albumin (P<0.001) and HBV viral load (P<0.001). Cytokines assay revealed increased expression of IL-6 (P=0.02), IL-10 (P=0.009) and TNF-α (P=0.003) in HBV-HEV superinfection patients compared to HBV monoinfection patients. Our study demonstrated that HEV superinfection in CHB patients was associated with progressive clinical manifestation, which is likely due to the enhanced expression of cytokines related with hepatocytes necrosis. HEV was also associated with repressed HBV replication, but the underlying mechanism requires further investigation.


Assuntos
Insuficiência Hepática Crônica Agudizada/virologia , Ascite/virologia , Encefalopatia Hepática/virologia , Hepatite B Crônica/virologia , Hepatite E/virologia , Síndrome Hepatorrenal/virologia , Cirrose Hepática/virologia , Superinfecção/virologia , Insuficiência Hepática Crônica Agudizada/complicações , Insuficiência Hepática Crônica Agudizada/imunologia , Insuficiência Hepática Crônica Agudizada/patologia , Adulto , Idoso , Alanina Transaminase/sangue , Alanina Transaminase/imunologia , Ascite/complicações , Ascite/imunologia , Ascite/patologia , Bilirrubina/sangue , Bilirrubina/imunologia , China , Feminino , Encefalopatia Hepática/complicações , Encefalopatia Hepática/imunologia , Encefalopatia Hepática/patologia , Anticorpos Anti-Hepatite/sangue , Vírus da Hepatite B/imunologia , Vírus da Hepatite B/patogenicidade , Hepatite B Crônica/complicações , Hepatite B Crônica/imunologia , Hepatite B Crônica/patologia , Hepatite E/complicações , Hepatite E/imunologia , Hepatite E/patologia , Vírus da Hepatite E/imunologia , Vírus da Hepatite E/patogenicidade , Hepatócitos/imunologia , Hepatócitos/patologia , Hepatócitos/virologia , Síndrome Hepatorrenal/complicações , Síndrome Hepatorrenal/imunologia , Síndrome Hepatorrenal/patologia , Humanos , Imunoglobulina G/sangue , Interleucina-10/sangue , Interleucina-10/imunologia , Interleucina-6/sangue , Interleucina-6/imunologia , Fígado/imunologia , Fígado/patologia , Fígado/virologia , Cirrose Hepática/complicações , Cirrose Hepática/imunologia , Cirrose Hepática/patologia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Superinfecção/complicações
4.
Hum Gene Ther ; 30(10): 1297-1305, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31502485

RESUMO

Adeno-associated virus (AAV) vector-mediated gene therapy is currently evaluated as a potential treatment for Crigler-Najjar syndrome (CN) (NCT03466463). Pre-existing immunity to AAV is known to hinder gene transfer efficacy, restricting enrollment of seropositive subjects in ongoing clinical trials. We assessed the prevalence of anti-AAV serotype 8 (AAV8) neutralizing antibodies (NAbs) in subjects affected by CN and investigated the impact of low NAb titers (<1:5) on liver gene transfer efficacy in an in vivo passive immunization model. A total of 49 subjects with a confirmed molecular diagnosis of CN were included in an international multicenter study (NCT02302690). Pre-existing NAbs against AAV8 were detected in 30.6% (15/49) of screened patients and, in the majority of positive cases, cross-reactivity to AAV2 and AAV5 was detected. To investigate the impact of low NAbs on AAV vector-mediated liver transduction efficiency, adult wild-type C57BL/6 mice were passively immunized with pooled human donor-derived immunoglobulins to achieve titers of up to 1:3.16. After immunization, animals were injected with different AAV8 vector preparations. Hepatic vector gene copy number was unaffected by low anti-AAV8 NAb titers when column-purified AAV vector batches containing both full and empty capsids were used. In summary, although pre-existing anti-AAV8 immunity can be found in about a third of subjects affected by CN, low anti-AAV8 NAb titers are less likely to affect liver transduction efficiency when using AAV vector preparations manufactured to contain both full and empty capsids. These findings have implications for the design of liver gene transfer clinical trials and for the definition of inclusion criteria related to seropositivity of potential participants.


Assuntos
Anticorpos Neutralizantes/biossíntese , Anticorpos Antivirais/biossíntese , Síndrome de Crigler-Najjar/terapia , Dependovirus/genética , Terapia Genética/métodos , Glucuronosiltransferase/genética , Adolescente , Adulto , Animais , Bilirrubina/imunologia , Bilirrubina/metabolismo , Capsídeo/imunologia , Capsídeo/metabolismo , Criança , Pré-Escolar , Síndrome de Crigler-Najjar/genética , Síndrome de Crigler-Najjar/imunologia , Síndrome de Crigler-Najjar/patologia , Dependovirus/imunologia , Antagonistas de Aminoácidos Excitatórios/uso terapêutico , Feminino , Expressão Gênica , Glucuronosiltransferase/deficiência , Glucuronosiltransferase/imunologia , Células HEK293 , Humanos , Imunidade Inata , Imunização Passiva , Fígado/imunologia , Fígado/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Fenobarbital/uso terapêutico , Fototerapia/métodos , Plasmídeos/química , Plasmídeos/metabolismo , Transfecção
6.
J Autoimmun ; 94: 122-133, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30098863

RESUMO

In Crohn's disease, pathogenic Th17-cells express low levels of CD39 ectonucleotidase and are refractory to the immunosuppressive effects of unconjugated bilirubin (UCB), an endogenous ligand for aryl-hydrocarbon-receptor (AhR). This resistance to AhR ligation might be associated with alterations in responses to hypoxia. Limited exposure to hypoxia appears beneficial in acute tissue injury. However, in protracted inflammation, hypoxemia may paradoxically result in Th17-cell activation. We report here that in vitro exposure of Th17-cells from Crohn's disease patients to hypoxia limits responsiveness to AhR stimulation by UCB, as reflected by lower CD39 levels. Blockade of hypoxia-inducible-factor-1alpha (HIF-1α) upregulates CD39 and favors Th17-cell regulatory responses. Resistance of Th17-cells to AhR signaling results, in part, from HIF-1α-dependent induction of ATP-binding cassette (ABC) transporters: multidrug-resistance-protein-1 (MDR1) and multidrug-resistance-associated-protein-4 (MRP4). Increased ABC transporters promote efflux of suppressive AhR ligands, such as UCB, from Th17-cells. Inhibition of MDR1, MRP4 and/or HIF-1α with ritonavir (RTV) reconstitutes AhR function in Th17-cells, enhancing therapeutic effects of UCB in dextran-sulfate-sodium-induced experimental colitis. Deleterious effects of hypoxia on Th17-cells in Crohn's disease can be ameliorated either by inhibiting HIF-1α or by suppressing ABC transporters to increase UCB availability as an AhR substrate. Targeting HIF-1α-ABC transporters could provide innovative therapeutic pathways for IBD.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/imunologia , Colite/imunologia , Doença de Crohn/imunologia , Subunidade alfa do Fator 1 Induzível por Hipóxia/imunologia , Proteínas Associadas à Resistência a Múltiplos Medicamentos/imunologia , Receptores de Hidrocarboneto Arílico/imunologia , Subfamília B de Transportador de Cassetes de Ligação de ATP/antagonistas & inibidores , Subfamília B de Transportador de Cassetes de Ligação de ATP/genética , Subfamília B de Transportador de Cassetes de Ligação de ATP/imunologia , Animais , Anti-Inflamatórios/imunologia , Anti-Inflamatórios/farmacologia , Apirase/genética , Apirase/imunologia , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Bilirrubina/imunologia , Bilirrubina/farmacologia , Hipóxia Celular , Colite/induzido quimicamente , Colite/tratamento farmacológico , Colite/genética , Doença de Crohn/genética , Doença de Crohn/patologia , Sulfato de Dextrana/administração & dosagem , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/antagonistas & inibidores , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Ativação Linfocitária , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mucosa/imunologia , Mucosa/patologia , Proteínas Associadas à Resistência a Múltiplos Medicamentos/antagonistas & inibidores , Proteínas Associadas à Resistência a Múltiplos Medicamentos/genética , Cultura Primária de Células , Ligação Proteica , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/imunologia , Receptores de Hidrocarboneto Arílico/genética , Ritonavir/farmacologia , Células Th17/efeitos dos fármacos , Células Th17/imunologia , Células Th17/patologia
7.
J Cell Mol Med ; 22(9): 4335-4343, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29974998

RESUMO

In vitiligo, cutaneous depigmentation is accompanied by increased T cell cytolytic activity targeting melanocytes, indicating that autoimmune tolerance is disrupted. The inhibited amount and function of Tregs have been indicated to be involved in the autoimmune intolerance in vitiligo, however, with the conclusion still controversial and the involved mechanism unknown. In this study, we explored the molecular and cellular alterations accounting for the impaired Treg response in vitiligo. Our results showed that the amount of Tregs was drastically reduced in peripheral blood of active vitiligo patients. Furthermore, the immunoregulatory function of Tregs was attenuated, with lower expression of CTLA4, IL-10 and TGF-ß. Moreover, the expression of HO-1, a functional modulator of Tregs, was decreased in vitiligo Tregs, and the concentrations of HO-1 metabolites, including bilirubin, CoHb and iron, were correspondingly decreased in serum of vitiligo patients. In addition, we treated the Tregs from vitiligo patients with Hemin, an agonist of HO-1, and found that enhanced HO-1 expression restored the function of Tregs by up-regulating IL-10 expression. Our study demonstrates the essential role of HO-1 in the impaired Treg response in vitiligo and indicates the potential of HO-1 as a therapeutic target in vitiligo management.


Assuntos
Antígeno CTLA-4/genética , Heme Oxigenase-1/genética , Interleucina-10/genética , Melanócitos/imunologia , Linfócitos T Reguladores/imunologia , Vitiligo/genética , Adolescente , Adulto , Idoso , Bilirrubina/sangue , Bilirrubina/imunologia , Antígeno CTLA-4/imunologia , Carboxihemoglobina/imunologia , Carboxihemoglobina/metabolismo , Progressão da Doença , Feminino , Regulação da Expressão Gênica , Heme Oxigenase-1/imunologia , Hemina/farmacologia , Humanos , Tolerância Imunológica , Interleucina-10/imunologia , Ferro/sangue , Ferro/imunologia , Contagem de Linfócitos , Masculino , Melanócitos/patologia , Pessoa de Meia-Idade , Cultura Primária de Células , Índice de Gravidade de Doença , Transdução de Sinais , Pele/imunologia , Pele/patologia , Linfócitos T Reguladores/efeitos dos fármacos , Linfócitos T Reguladores/patologia , Fator de Crescimento Transformador beta/genética , Fator de Crescimento Transformador beta/imunologia , Vitiligo/imunologia , Vitiligo/patologia
8.
Sci Rep ; 8(1): 7444, 2018 05 10.
Artigo em Inglês | MEDLINE | ID: mdl-29748620

RESUMO

Phototherapy was introduced in the early 1950's, and is the primary treatment of severe neonatal jaundice or Crigler-Najjar syndrome. Nevertheless, the potential biological effects of the products generated from the photodegradation of bilirubin during phototherapy remain unknown. This is very relevant in light of recent clinical observations demonstrating that the use of aggressive phototherapy can increase morbidity or even mortality, in extremely low birthweight (ELBW) infants. The aim of our study was to investigate the effects of bilirubin, lumirubin (LR, its major photo-oxidative product), and BOX A and B (its monopyrrolic oxidative products) on the central nervous system (CNS) using in vitro and ex vivo experimental models. The effects of bilirubin photoproducts on cell viability and expression of selected genes were tested in human fibroblasts, three human CNS cell lines (neuroblastoma SH-SY5Y, microglial HMC3, and glioblastoma U-87 cell lines), and organotypic rat hippocampal slices. Neither bilirubin nor its photo-oxidative products affected cell viability in any of our models. In contrast, LR in biologically-relevant concentrations (25 µM) significantly increased gene expression of several pro-inflammatory genes as well as production of TNF-α in organotypic rat hippocampal slices. These findings might underlie the adverse outcomes observed in ELBW infants undergoing aggressive phototherapy.


Assuntos
Bilirrubina/análogos & derivados , Bilirrubina/imunologia , Hipocampo/imunologia , Inflamação/imunologia , Fototerapia/efeitos adversos , Animais , Linhagem Celular , Sobrevivência Celular , Hipocampo/patologia , Humanos , Recém-Nascido , Inflamação/patologia , Icterícia Neonatal/terapia , Fotólise , Ratos , Ratos Wistar , Fator de Necrose Tumoral alfa/imunologia
9.
Chron Respir Dis ; 15(2): 138-145, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29117798

RESUMO

Various biomarkers have emerged as potential surrogates to represent various subgroups of chronic obstructive pulmonary disease (COPD), which manifest with different phenotypes. However, the biomarkers representing never-smokers with COPD have not yet been well elucidated. The aim of this study was to evaluate the associations of certain serum and radiological biomarkers with the presence of COPD in never-smokers. To explore the associations of serum and radiological biomarkers with the presence of COPD in never-smokers, we conducted a cross-sectional patient cohort study composed of never-smokers from the COPD in Dusty Areas (CODA) cohort, consisting of subjects living in dusty areas near cement plants in South Korea. Of the 131 never-smokers in the cohort, 77 (58.8%) had COPD. There were no significant differences in the number of subjects with high levels of inflammatory biomarkers (>90th percentile of never-smokers without COPD), including white blood cell count, total bilirubin, interleukin (IL)-6, IL-8, and C-reactive protein, or radiologic measurements (including emphysema index and mean wall area percentage) between never-smokers with COPD and those without COPD. However, the number of subjects with high uric acid was significantly higher in never-smokers with COPD than never-smokers without COPD (31.2% (24/77) vs. 11.1% (6/54); p = 0.013). In addition, multivariate analysis revealed that high uric acid was significantly associated with the presence of COPD in never-smokers (adjusted relative risk: 1.63; 95% confidence interval: 1.21, 2.18; p = 0.001). Our study suggests that high serum levels of uric acid might be a potential biomarker for assessing the presence of COPD in never-smokers.


Assuntos
Bilirrubina/imunologia , Proteína C-Reativa/imunologia , Interleucina-6/imunologia , Interleucina-8/imunologia , não Fumantes , Doença Pulmonar Obstrutiva Crônica/imunologia , Ácido Úrico/imunologia , Idoso , Estudos de Casos e Controles , Estudos de Coortes , Estudos Transversais , Poeira , Dispneia , Feminino , Volume Expiratório Forçado , Humanos , Inflamação , Pulmão/diagnóstico por imagem , Pulmão/fisiopatologia , Masculino , Instalações Industriais e de Manufatura , Doença Pulmonar Obstrutiva Crônica/diagnóstico por imagem , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Qualidade de Vida , República da Coreia , Características de Residência , Tomografia Computadorizada por Raios X , Capacidade Vital
10.
Arch Gynecol Obstet ; 296(5): 885-895, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28871471

RESUMO

BACKGROUND AND AIM: The basis of host response in hepatitis E virus (HEV)-related liver disease during pregnancy-is still unclear. The study aims to evaluate anthropometric parameters and biochemical nutritional parameters in hepatitis E infection during pregnancy and correlate it with severity of the disease. METHODS: A total of consecutive 267 pregnant women with jaundice were recruited. The jaundiced patients were classified as acute viral hepatitis (AVH) or acute liver failure (ALF). The study group included 144 pregnant women with HEV infection and 144 healthy asymptomatic age and gestational age-matched pregnant women as controls. Nutritional factors were evaluated on basis of anthropometric parameters and biochemical factors. Serum prealbumin and folate were assayed by ELISA kit. RESULTS: All nutritional parameters were significantly lower in pregnant women with HEV infection as compared with healthy pregnant controls. Some of the nutritional parameters significantly lower in ALF pregnant patients compared to AVH pregnant patients in HEV group. Linear regression analysis of the AVH group showed that serum total protein and mid-upper arm circumference (MUAC) were significant predictors for bilirubin, body mass index (BMI) could significantly predict viral load level, and total protein, prealbumin, folate, and tricep skin fold thickness (TSFT) could significantly predict prothrombin time. In ALF group, serum prealbumin could significantly predict bilirubin levels and MUAC could significantly predict prothrombin time. CONCLUSION: Malnutrition might confer a higher predisposition for HEV infection during pregnancy and is associated with increased severity of disease in terms of occurrence of ALF.


Assuntos
Vírus da Hepatite E , Hepatite E/epidemiologia , Desnutrição , Complicações Infecciosas na Gravidez/epidemiologia , Adulto , Bilirrubina/imunologia , Estudos de Casos e Controles , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Icterícia/epidemiologia , Falência Hepática Aguda/epidemiologia , Gravidez , Complicações Infecciosas na Gravidez/diagnóstico , Tempo de Protrombina , Carga Viral
11.
J Coll Physicians Surg Pak ; 26(6): 539-40, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27353998

RESUMO

Many different blood group systems, such as Rh, ABO, Kell, Kidd, Duffy, MNS, have been reported as causes of hemolytic disease of the newborn. Hemolysis due to minor blood group incompatibility in the fetus or newborn has been determined in isolated case reports. Here, we report a case of a patient who had received red cell transfusion due to severe Rh c and E incompatibility, leading to hemolytic anemia with heart failure. The mother and the baby were grouped B and B, respectively, both being positive for RhD antigen. The baby's blood group type was C+, c+, E+, e+, K-, while her mother's blood group type was C+, c-, E-, e+, K-. Our patient was diagnosed as Rh c and E incompatibility, leading to the hemolytic anemia. Minor blood group incompatibility should be considered in infants with prolonged jaundice and severe anemia, leading to heart failure.


Assuntos
Anemia Hemolítica/etiologia , Bilirrubina/sangue , Incompatibilidade de Grupos Sanguíneos , Eritroblastose Fetal/sangue , Insuficiência Cardíaca/etiologia , Hemoglobinas/análise , Hiperbilirrubinemia/etiologia , Anemia Hemolítica/imunologia , Bilirrubina/imunologia , Transfusão de Eritrócitos , Feminino , Insuficiência Cardíaca/imunologia , Humanos , Hiperbilirrubinemia/imunologia , Recém-Nascido , Isoanticorpos , Isoimunização Rh
12.
Int J Biochem Cell Biol ; 45(12): 2843-51, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24144577

RESUMO

Nearly a century ago, jaundiced patients were observed to have surprising and spontaneous remissions from incurable immunologic diseases including rheumatoid arthritis, allergy, and asthma. The mystery of why this phenomenon occurred remains unresolved to this day. Bilirubin has traditionally been considered an excretory product resulting from heme metabolism with little benefit to human physiology. In the past few decades, however, the salutary role of this byproduct as a potent antioxidant has been repeatedly noted. Most recently, the molecule has been found to possess immunomodulatory properties that rival its redox capacity, possibly explaining its ability to suppress inflammation. In this review, we specifically examine unconjugated bilirubin (UCB) as an immunomodulator and explore the molecular basis for its immunosuppressive effects.


Assuntos
Doenças Autoimunes/imunologia , Bilirrubina/imunologia , Bilirrubina/farmacologia , Animais , Doenças Autoimunes/tratamento farmacológico , Humanos , Imunomodulação , Transdução de Sinais
13.
Sci China Life Sci ; 55(9): 774-81, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23015125

RESUMO

Liver transplantation is an established therapy for end-stage liver diseases. Graft rejection occurs unless the recipient receives immunosuppression after transplantation. This study aimed to explore the mechanism of acute rejection of liver allografts in rats pre-treated with total body irradiation to eliminate passenger lymphocytes and to define the role of CD4(+)CD25(+) regulatory T cells in the induction of immunotolerance in the recipient. Male Lewis rats were used as donors and male DA rats were recipients. Rats were randomly assigned to the following four groups: control group, homogeneity liver transplantation group, idio-immunotolerance group and acute rejection group. After transplantation, the survival time of each group, serum alanine aminotransferase, total bilirubin levels, number of Foxp3(+)CD4(+)CD25(+) regulatory T cells, expression of glucocorticoid-induced tumor necrosis factor receptor on T cell subgroups, histopathology of the hepatic graft and spleen cytotoxic T lymphocyte lytic activity were measured. In the acute rejection group, where donors were preconditioned with total body irradiation before liver transplantation, all recipients died between day 17 and day 21. On day 14, serum alanine aminotransferase increased significantly to (459.2±76.9) U L(-1), total bilirubin increased to (124.1±33.7) µmol L(-1) (P<0.05) and the ratio of Foxp3(+)CD4(+)CD25(+) regulatory T cells decreased significantly to 1.50%±0.50% (P<0.05) compared with the other groups. Analysis of the T cell subpopulations in the acute rejection group varied from the other groups. Histological analysis showed typical changes of acute rejection in the acute rejection group only. Preconditioning of the donors with total body irradiation eliminated passenger lymphocytes of the liver graft, and thus affected the course of tolerance and induced acute rejection after liver transplantation.


Assuntos
Rejeição de Enxerto/imunologia , Tolerância Imunológica/imunologia , Transplante de Fígado/imunologia , Irradiação Corporal Total/efeitos adversos , Doença Aguda , Alanina Transaminase/sangue , Alanina Transaminase/imunologia , Animais , Bilirrubina/sangue , Bilirrubina/imunologia , Citotoxicidade Imunológica/imunologia , Fatores de Transcrição Forkhead/imunologia , Fatores de Transcrição Forkhead/metabolismo , Rejeição de Enxerto/sangue , Tolerância Imunológica/efeitos da radiação , Subunidade alfa de Receptor de Interleucina-2/imunologia , Subunidade alfa de Receptor de Interleucina-2/metabolismo , Fígado/imunologia , Fígado/metabolismo , Fígado/patologia , Transplante de Fígado/métodos , Masculino , Distribuição Aleatória , Ratos , Ratos Endogâmicos Lew , Ratos Endogâmicos , Baço/imunologia , Baço/metabolismo , Baço/patologia , Linfócitos T Citotóxicos/imunologia , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/metabolismo , Fatores de Tempo , Fator de Necrose Tumoral alfa/imunologia , Fator de Necrose Tumoral alfa/metabolismo
14.
Clin Biochem ; 45(10-11): 845-7, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22537456

RESUMO

OBJECTIVES: To measure the levels of serum soluble death receptor 5 (sDR5) in patients with hepatitis B. DESIGN AND METHODS: sDR5 concentration in 60 HBV infected patients and 30 healthy volunteers were measured by ELISA. RESULTS: sDR5 concentration in the HBV infected patients was decreased and correlated with serum ALT, Tbil level, albumin/globulin ratio and HBV antigen level. CONCLUSIONS: Decreased serum sDR5 is associated with high level of liver damage and inhibited HBV antigen expression.


Assuntos
Antígenos Virais/imunologia , Hepatite B Crônica/imunologia , Fígado/imunologia , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/imunologia , Alanina Transaminase/sangue , Alanina Transaminase/imunologia , Antígenos Virais/sangue , Aspartato Aminotransferases/sangue , Aspartato Aminotransferases/imunologia , Bilirrubina/sangue , Bilirrubina/imunologia , Ensaio de Imunoadsorção Enzimática , Antígenos de Superfície da Hepatite B/sangue , Antígenos de Superfície da Hepatite B/imunologia , Antígenos E da Hepatite B/sangue , Antígenos E da Hepatite B/imunologia , Vírus da Hepatite B/imunologia , Vírus da Hepatite B/fisiologia , Hepatite B Crônica/sangue , Hepatite B Crônica/virologia , Interações Hospedeiro-Patógeno/imunologia , Humanos , Fígado/patologia , Fígado/virologia , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/sangue , Solubilidade
15.
Am J Perinatol ; 29(6): 449-54, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22399212

RESUMO

OBJECTIVE: To determine the clinical spectrum of hemolytic disease due to irregular blood subgroup incompatibility in hospitalized neonates. STUDY DESIGN: The medical records of the all hospitalized newborn patients diagnosed with indirect hyperbilirubinemia due to subgroup incompatibility in Kell, C, c, E, and e systems were included in the study. Data from 106 newborns with hemolytic jaundice due to irregular blood subgroups were retrospectively evaluated, and clinical and laboratory findings were compared between patients . The treatment modalities given to the patients of each subgroup types and the laboratory findings and treatment modalities of the cases according to Coombs tests results were also analyzed. Fetal affection of the hemolysis and also fetal losses due to irregular red-cell alloimmunization were not detected in prenatal course, as there was no follow-up of these pregnancies. RESULTS: The mean postnatal hospitalizing age was 6.1 ± 5.2 days after birth. The mean total bilirubin level and the mean hemoglobin value on hospitalization were 343.7 ± 63.3 µmol/L (=20.1 ± 3.7 mg/dL) and 14.9 ± 3.4 g/dL, respectively. Of 106 patients identified with irregular subgroup incompatibility, 40 infants (37.7%) were associated with C, 22 (20.8%) with c, 30 (28.3%) with E, 9 (8.5%) with e, and 5 (4.7%) with Kell subgroup system. Positive Coombs tests (either direct and/or indirect) occurred in 28.3% of the study cases. Hydrops fetalis was determined in 5 of 106 neonates (4.7%). Twenty-two of 106 (20.8%) patients required total exchange transfusion. Positive Coombs test in cases required total exchange transfusion was 63.6%. CONCLUSION: Our data expose the magnitude and spectrum of the potential developing severe hemolytic disease and immune hydrops due to irregular subgroup incompatibility. Minor group antibody screening is recommended both in the mother and the high-risk infants with hyperbilirubinemia and hemolytic disease of the newborn.


Assuntos
Bilirrubina/sangue , Eritroblastose Fetal/imunologia , Transfusão Total/estatística & dados numéricos , Hemoglobinas/análise , Hiperbilirrubinemia/etiologia , Sistema do Grupo Sanguíneo de Kell/imunologia , Bilirrubina/imunologia , Teste de Coombs , Eritroblastose Fetal/terapia , Feminino , Humanos , Hiperbilirrubinemia/imunologia , Lactente , Recém-Nascido , Masculino , Estudos Retrospectivos
16.
J Leukoc Biol ; 90(5): 997-1015, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21807743

RESUMO

The immunomodulatory and immunotoxic effects of purified UCB have not been evaluated previously at clinically relevant UCB concentrations and UCB:BSA ratios. To delineate the molecular mechanism of UCB-induced immunomodulation, immune cells were exposed to clinically relevant concentrations of UCB. It inhibited LPS-induced B cell proliferation and cytokine production from splenic macrophages. UCB (≥25 µM) was toxic to unfractionated splenocytes, splenic T cells, B cells, macrophages, LPS-stimulated CD19(+) B cells, human PBMCs, and RBCs. Purified UCB also was found to be toxic to splenocytes and human PBMCs. UCB induced necrosis and apoptosis in splenocytes. UCB activated the extrinsic and intrinsic pathways of apoptosis, as reflected by the markers, such as CD95, caspase-8, Bax, MMP, cytoplasmic Ca(+2), caspase-3, and DNA fragmentation. UCB depleted GSH and activated p38MAPK. NAC, caspase inhibitors, and p38MAPK inhibitor attenuated the UCB-induced apoptosis. In vivo administration of ≥25 mg/kbw UCB induced atrophy of spleen, depletion of bone marrow cells, and leukopenia and decreased lymphocyte count and the T and B cell response to mitogens. UCB administration to mice led to induction of oxidative stress, activation of p38MAPK, and cell death in splenocytes. These parameters were attenuated by the injection of NAC and the p38MAPK inhibitor. Our results demonstrate for the first time that clinically relevant concentrations of UCB induce apoptosis and necrosis in immune cells by depleting cellular GSH. These findings should prove useful in understanding the immunosuppression associated with hyperbilirubinemia.


Assuntos
Bilirrubina/farmacologia , Fatores Imunológicos/farmacologia , Animais , Apoptose/efeitos dos fármacos , Linfócitos B/efeitos dos fármacos , Linfócitos B/patologia , Bilirrubina/imunologia , Cálcio/metabolismo , Caspase 8/metabolismo , Fragmentação do DNA/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Fatores Imunológicos/imunologia , Imunomodulação , Ativação de Macrófagos/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Macrófagos/patologia , Masculino , Camundongos , Transdução de Sinais/efeitos dos fármacos , Linfócitos T/imunologia , Proteína X Associada a bcl-2/metabolismo , Receptor fas/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno
17.
Glia ; 59(1): 14-25, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20967881

RESUMO

Jaundice and sepsis are common neonatal conditions that can lead to neurodevelopment sequelae, namely if present at the same time. We have reported that tumor necrosis factor (TNF)-α and interleukin (IL)-1ß are produced by cultured neurons and mainly by glial cells exposed to unconjugated bilirubin (UCB). The effects of these cytokines are mediated by cell surface receptors through a nuclear factor (NF)-κB-dependent pathway that we have showed to be activated by UCB. The present study was designed to evaluate the role of TNF-α and IL-1ß signaling on astrocyte reactivity to UCB in rat cortical astrocytes. Exposure of astrocytes to UCB increased the expression of both TNF-α receptor (TNFR)1 and IL-1ß receptor (IL-1R)1, but not TNFR2, as well as their activation, observed by augmented binding of receptors' molecular adaptors, TRAF2 and TRAF6, respectively. Silencing of TNFR1, using siRNA technology, or blockade of IL-1ß cascade, using its endogenous antagonist, IL-1 receptor antagonist (IL-1ra), prevented UCB-induced cytokine release and NF-κB activation. Interestingly, lack of TNF-α signal transduction reduced UCB-induced cell death for short periods of incubation, although an increase was observed after extended exposure; in contrast, inhibition of IL-1ß cascade produced a sustained blockade of astrocyte injury by UCB. Together, our data show that inflammatory pathways are activated during in vitro exposure of rat cortical astrocytes to UCB and that this activation is prolonged in time. This supports the concept that inflammatory pathways play a role in brain damage by UCB, and that they may represent important pharmacological targets.


Assuntos
Astrócitos/metabolismo , Bilirrubina/farmacologia , Interleucina-1beta/metabolismo , Transdução de Sinais/fisiologia , Fator de Necrose Tumoral alfa/metabolismo , Análise de Variância , Animais , Astrócitos/efeitos dos fármacos , Astrócitos/imunologia , Bilirrubina/imunologia , Bilirrubina/metabolismo , Western Blotting , Morte Celular/efeitos dos fármacos , Morte Celular/imunologia , Células Cultivadas , Córtex Cerebral/efeitos dos fármacos , Córtex Cerebral/imunologia , Córtex Cerebral/metabolismo , Ensaio de Imunoadsorção Enzimática , Imunoprecipitação , Interleucina-1beta/imunologia , NF-kappa B/imunologia , NF-kappa B/metabolismo , RNA Interferente Pequeno , Ratos , Ratos Wistar , Receptores de Interleucina-1/imunologia , Receptores de Interleucina-1/metabolismo , Receptores Tipo I de Fatores de Necrose Tumoral/imunologia , Receptores Tipo I de Fatores de Necrose Tumoral/metabolismo , Transdução de Sinais/efeitos dos fármacos , Fator 2 Associado a Receptor de TNF/imunologia , Fator 2 Associado a Receptor de TNF/metabolismo , Fator 6 Associado a Receptor de TNF/imunologia , Fator 6 Associado a Receptor de TNF/metabolismo , Transfecção , Fator de Necrose Tumoral alfa/imunologia
18.
Neurobiol Dis ; 40(3): 663-75, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20727973

RESUMO

Microglia constitute the brain's immunocompetent cells and are intricately implicated in numerous inflammatory processes included in neonatal brain injury. In addition, clearance of tissue debris by microglia is essential for tissue homeostasis and may have a neuroprotective outcome. Since unconjugated bilirubin (UCB) has been proven to induce astroglial immunological activation and neuronal cell death, we addressed the question of whether microglia acquires a reactive phenotype when challenged by UCB and intended to characterize this response. In the present study we report that microglia primary cultures stimulated by UCB react by the acquisition of a phagocytic phenotype that shifted into an inflammatory response characterized by the secretion of the pro-inflammatory cytokines tumour necrosis factor (TNF)-α, interleukin (IL)-1ß, and IL-6, upregulation of cyclooxygenase (COX)-2 and increased matrix metalloproteinase (MMP)-2 and -9 activities. Further investigation upon upstream signalling pathways revealed that UCB led to the activation of mitogen-activated protein kinases (MAPKs) and nuclear factor (NF)-κB at an early time point, suggesting that these pathways might underlie both the phagocytic and the inflammatory phenotypes engaged by microglia. Curiously, the phagocytic and inflammatory phenotypes in UCB-activated microglia seem to alternate along time, indicating that microglia reacts towards UCB insult firstly with a phagocytic response, in an attempt to constrain the lesion extent and comprising a neuroprotective measure. Upon prolonged UCB exposure periods, either a shift on global microglia reaction occurred or there could be two distinct sub-populations of microglial cells, one directed at eliminating the damaged cells by phagocytosis, and another that engaged a more delayed inflammatory response. In conclusion, microglial cells are relevant partners to consider during bilirubin encephalopathy and the modulation of its activation might be a promising therapeutic target.


Assuntos
Bilirrubina/efeitos adversos , Inflamação/metabolismo , Kernicterus/metabolismo , Microglia/metabolismo , Fagocitose/fisiologia , Animais , Bilirrubina/imunologia , Bilirrubina/metabolismo , Western Blotting , Células Cultivadas , Citocinas/metabolismo , Ativação Enzimática/fisiologia , Expressão Gênica , Inflamação/imunologia , Inflamação/patologia , Kernicterus/imunologia , Kernicterus/patologia , Microglia/imunologia , Microglia/patologia , Proteínas Quinases Ativadas por Mitógeno/metabolismo , NF-kappa B/metabolismo , Ratos , Ratos Wistar
19.
J Clin Immunol ; 28(5): 520-7, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18584314

RESUMO

INTRODUCTION: Granulysin is a cytotoxic molecule involved in cellular immune reactions. MATERIALS AND METHODS: The levels of granulysin mRNA in the peripheral blood and serum granulysin of patients with primary biliary cirrhosis (PBC) were determined by quantitative polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. The expression of granulysin mRNA and serum protein in PBC was increased compared to the controls. RESULTS: The expression of granulysin mRNA or serum protein showed close associations, respectively, with natural killer cell population in PBC patients. Serum granulysin was down-regulated by steroid and ursodeoxycholic therapy for PBC according to the improvement of severity of PBC. In addition, the expression of serum granulysin were related to serum total bilirubin and Mayo Clinic risk score. The serum granulysin reflected the cellular immune status of patients with PBC, and the expression correlated with the severity of PBC. CONCLUSION: Therefore, there is a clinical benefit to monitoring granulysin as a biomarker of the prognosis of patients with PBC.


Assuntos
Antígenos de Diferenciação de Linfócitos T/genética , Bilirrubina/genética , Células Matadoras Naturais/metabolismo , Cirrose Hepática Biliar/genética , Linfócitos T Citotóxicos/metabolismo , Adulto , Antígenos de Diferenciação de Linfócitos T/sangue , Antígenos de Diferenciação de Linfócitos T/imunologia , Bilirrubina/sangue , Bilirrubina/imunologia , Biomarcadores/sangue , Citotoxicidade Imunológica/genética , Feminino , Expressão Gênica , Humanos , Células Matadoras Naturais/imunologia , Cirrose Hepática Biliar/sangue , Cirrose Hepática Biliar/diagnóstico , Cirrose Hepática Biliar/imunologia , Masculino , Pessoa de Meia-Idade , Prognóstico , RNA Mensageiro/análise , Índice de Gravidade de Doença , Estatística como Assunto , Linfócitos T Citotóxicos/imunologia
20.
Col. med. estado Táchira ; 15(3): 44-47, jul.-sept. 2006.
Artigo em Espanhol | LILACS | ID: lil-530751

RESUMO

Las anemias hemolíticas autoinmunitarias se caracterizan por la presencia de inmunoglobulinas en la superficie eritrocitaria dirigidas contra los determinantes antigénicos de los hematíes. La anemia hemolítica autoinmune por anticuerpos calientes se caracteriza porque los autoanticuerpos actúan a la temperatura del organismo (37°C), son de clase IgG y la hemólisis es predominantemente extravascular, siendo el tipo más frecuente de anemia hemolítica autoinmune en los niños de 2-12 años de edad. Sus manifestaciones clínicas son postración, palidez, ictericia, fiebre y hemoglobinuria. El diagnóstico de las AHAI se establece con la prueba de Coombs. La administración de corticoesteroides constituye el tratamiento inicial de elección. Se presenta el caso de una preescolar femenina de tres años de edad procedente del medio rural, quien exhibe las características clínicas, paraclínica y epidemiológicas de anemia hemolítica autoinmune por anticuerpos calientes, con respuesta satisfactoria a la terapia con esteroides.


Assuntos
Humanos , Feminino , Pré-Escolar , Anemia Hemolítica Autoimune/classificação , Anemia Hemolítica Autoimune/diagnóstico , Anemia Hemolítica Autoimune/patologia , Anorexia/diagnóstico , Anticorpos/efeitos adversos , Icterícia/diagnóstico , Imunoglobulina G/uso terapêutico , Imunoglobulinas/análise , Palidez/diagnóstico , Teste de Coombs/métodos , Bilirrubina/imunologia , Leucemia Linfoide/sangue , Pediatria , Transfusão de Eritrócitos/métodos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...