RESUMO
The tumour necrosis factor (TNF)-α-induced proteins (TNFAIP)9 and TNFAIP3 play an important pathogenic role in murine arthritis. To clarify their pathophysiological roles in patients with rheumatoid arthritis (RA), we examined their expression and localization in peripheral blood mononuclear cells (PBMC). TNFAIP9 and TNFAIP3 mRNA expression was determined in PBMC of RA patients and healthy subjects (control). Flow cytometry was used to analyse the main TNFAIP9- and TNFAIP3-expressing cell populations. TNFAIP9 and TNFAIP3 mRNA expression levels were examined in vitro on CD14(+) cells stimulated with TNF-α and lipopolysaccharide (LPS). The expression levels of TNFAIP9 and TNFAIP3 mRNA were also measured before and 12 weeks after treatment with tocilizumab and abatacept. TNFAIP9 expression was significantly higher, while TNFAIP3 expression was lower in PBMC of RA (n=36) than the control (n=24) (each P < 0.05). TNFAIP9 was expressed on CD14(+) cells, especially in human leucocyte antigen D-related (HLA-DR)(+) CD14(bright) CD16(-) cells, while TNFAIP3 was expressed mainly on CD3(+) T cells. TNF-α and LPS induced TNFAIP9 and TNFAIP3 in human CD14(+) monocytes in vitro. Treatment with tocilizumab (n=13), but not abatacept (n=11), significantly reduced TNFAIP9 mRNA expression in PBMC, which was associated with reduction in the number of circulating CD14(bright) monocytes. The expression of TNFAIP9 in CD14(+) cells was specifically elevated in patients with RA, regulated by TNF-α and LPS, and suppressed by tocilizumab, while TNFAIP3 in PBMC showed different localization and induction patterns.
Assuntos
Artrite Reumatoide/genética , Artrite Reumatoide/imunologia , Expressão Gênica , Proteínas de Membrana/genética , Monócitos/imunologia , Monócitos/metabolismo , Oxirredutases/genética , Adulto , Idoso , Anticorpos Monoclonais Humanizados/farmacologia , Antirreumáticos/uso terapêutico , Artrite Reumatoide/diagnóstico , Artrite Reumatoide/tratamento farmacológico , Estudos de Casos e Controles , Proteínas de Ligação a DNA/genética , Feminino , Humanos , Imunofenotipagem , Peptídeos e Proteínas de Sinalização Intracelular/genética , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/imunologia , Leucócitos Mononucleares/metabolismo , Receptores de Lipopolissacarídeos/metabolismo , Lipopolissacarídeos/farmacologia , Masculino , Pessoa de Meia-Idade , Monócitos/efeitos dos fármacos , Proteínas Nucleares/genética , RNA Mensageiro/genética , Receptores de IgG/metabolismo , Proteína 3 Induzida por Fator de Necrose Tumoral alfa , Fator de Necrose Tumoral alfa/farmacologiaRESUMO
OBJECTIVE: The objective of this paper is to identify predictors for the response to treatment of acute lupus hemophagocytic syndrome (ALHS). METHODS: We reviewed seven cases with ALHS admitted to our hospital and published ALHS cases identified in the 2001-2014 Medline database, and then conducted univariate and multivariate analyses to identify predictors for the response to treatment. RESULTS: Review of our cases showed a significant and negative correlation between serum ferritin and anti-DNA antibody (p = 0.0025). All three patients treated with cyclosporine A (CsA) were considered responders despite high serum ferritin and corticosteroid resistance. We also reviewed 93 patients with ALHS identified in 46 articles. Multiple logistic regression analysis identified C-reactive protein (CRP) (OR 0.83, p = 0.042) and hemoglobin (OR 1.53, p = 0.026) measured at diagnosis of ALHS as significant predictors of the response to corticosteroid monotherapy. Moreover, among 32 patients treated with CsA, serum ferritin was significantly higher in CsA responders (12163 ± 16864 µg/l, n = 22) than in non-responders (3456 ± 6267/µg/l, p = 0.020, n = 10). Leukocyte count was significantly lower in the CsA responders (1940.0 ± 972.3/µl) than in the non-responders (3253 ± 2198/µl, p = 0.034). CONCLUSION: Low CRP and high hemoglobin can predict a positive response to corticosteroid monotherapy while high serum ferritin and low leukocyte count can predict a positive response to CsA in patients with ALHS and therefore, when corticosteroid monotherapy is not effective in such cases, CsA could be the first choice of an additional immunosuppressive agent.
Assuntos
Linfo-Histiocitose Hemofagocítica/sangue , Linfo-Histiocitose Hemofagocítica/tratamento farmacológico , Doença Aguda , Adolescente , Adulto , Idoso , Anti-Inflamatórios/uso terapêutico , Anticorpos Antinucleares/sangue , Proteína C-Reativa/metabolismo , Ciclosporina/uso terapêutico , Feminino , Ferritinas/sangue , Hemoglobinas/metabolismo , Humanos , Imunoglobulinas Intravenosas/uso terapêutico , Imunossupressores/uso terapêutico , Linfo-Histiocitose Hemofagocítica/patologia , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Prednisolona/administração & dosagem , Prednisolona/uso terapêutico , Estudos Retrospectivos , Adulto JovemRESUMO
Infection with Helicobacter pylori cagA-positive strains is associated with gastric adenocarcinoma. Intestinal metaplasia is a precancerous lesion of the stomach characterized by transdifferentiation of the gastric mucosa to an intestinal phenotype. The H. pylori cagA gene product, CagA, is delivered into gastric epithelial cells, where it undergoes tyrosine phosphorylation by Src family kinases. Tyrosine-phosphorylated CagA specifically binds to and activates SHP-2 phosphatase, thereby inducing cell-morphological transformation. We report here that CagA physically interacts with E-cadherin independently of CagA tyrosine phosphorylation. The CagA/E-cadherin interaction impairs the complex formation between E-cadherin and beta-catenin, causing cytoplasmic and nuclear accumulation of beta-catenin. CagA-deregulated beta-catenin then transactivates beta-catenin-dependent genes such as cdx1, which encodes intestinal specific CDX1 transcription factor. In addition to beta-catenin signal, CagA also transactivates p21(WAF1/Cip1), again, in a phosphorylation-independent manner. Consequently, CagA induces aberrant expression of an intestinal-differentiation marker, goblet-cell mucin MUC2, in gastric epithelial cells that have been arrested in G1 by p21(WAF1/Cip1). These results indicate that perturbation of the E-cadherin/beta-catenin complex by H. pylori CagA plays an important role in the development of intestinal metaplasia, a premalignant transdifferentiation of gastric epithelial cells from which intestinal-type gastric adenocarcinoma arises.
Assuntos
Antígenos de Bactérias/metabolismo , Proteínas de Bactérias/metabolismo , Caderinas/metabolismo , Transformação Celular Neoplásica/metabolismo , Mucosa Gástrica/metabolismo , Lesões Pré-Cancerosas/metabolismo , Neoplasias Gástricas/etiologia , beta Catenina/metabolismo , Adenocarcinoma/etiologia , Adenocarcinoma/metabolismo , Adenocarcinoma/patologia , Antígenos de Bactérias/análise , Proteínas de Bactérias/análise , Caderinas/análise , Linhagem Celular , Núcleo Celular/química , Núcleo Celular/metabolismo , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/patologia , Inibidor de Quinase Dependente de Ciclina p21/genética , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Citoplasma/química , Citoplasma/metabolismo , Mucosa Gástrica/patologia , Regulação Neoplásica da Expressão Gênica , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Humanos , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patologia , Mucina-2 , Mucinas/metabolismo , Fosforilação , Lesões Pré-Cancerosas/genética , Lesões Pré-Cancerosas/patologia , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/patologia , Ativação Transcricional , Tirosina/metabolismo , beta Catenina/análiseRESUMO
Thymic stromal lymphopoietin (TSLP) is an interleukin-7 (IL-7)-like cytokine involved in T helper 2 type immune responses. The primary target of TSLP is myeloid dendritic cells (DCs), however, little is known about the mechanism by which TSLP elicits respiratory IgA immune responses upon mucosal immunization. Here, we found that the levels of TSLP and TSLPR were upregulated in the mucosal DCs of mice nasally immunized with pneumococcal surface protein A (PspA) plus cholera toxin (CT) compared with those immunized with PspA alone. PspA-specific IgA responses, but not IgG Ab responses were significantly reduced in both serum and mucosal secretions of TSLPR knockout mice compared with wild-type mice after nasal immunization with PspA plus CT. Furthermore, CD11c+ mucosal DCs isolated from TSLPR knockout mice nasally immunized with PspA plus CT were less activated and exhibited markedly reduced expression of IgA-enhancing cytokines (e.g., APRIL, BAFF, and IL-6) compared with those from equivalently immunized wild-type mice. Finally, exogenous TSLP promoted production of IgAs in an in vitro DC-B cell co-culture system as exhibited by enhanced IL-6 production. These results suggest that TSLP-TSLPR signaling is pivotal in the induction of nasal respiratory immunity against pathogenic pneumococcal infection.
Assuntos
Linfócitos B/imunologia , Proteínas de Bactérias/imunologia , Toxina da Cólera/imunologia , Citocinas/metabolismo , Células Dendríticas/imunologia , Imunoglobulinas/metabolismo , Receptores de Citocinas/metabolismo , Mucosa Respiratória/patologia , Administração Intranasal , Animais , Anticorpos Antibacterianos/metabolismo , Antígeno CD11c/metabolismo , Células Cultivadas , Técnicas de Cocultura , Imunidade Humoral , Imunização , Imunoglobulina A/metabolismo , Imunoglobulinas/genética , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Knockout , Receptores de Citocinas/genética , Linfopoietina do Estroma do TimoRESUMO
We evaluated the effect of nitric oxide (NO) on vascular endothelial growth factor (VEGF) gene expression in human A-172 glioblastoma cells and human HepG2 hepatocellular carcinoma cells. The mRNA level of VEGF increased in response to S-Nitroso-N-acetyl-D,L-penicillamine (SNAP) in both cell lines, and increased in mRNA level well coincided with VEGF protein production in A-172 cells. SNAP at 0.5 mM induced maximal stimulation of 4.4 and 3.7 kb VEGF mRNA expression after 6 h about 11 and 8 fold increase, respectively above control level. Similar VEGF mRNA accumulation was observed also with NOR3, another chemical NO generator. To evaluate the effect of SNAP on VEGF mRNA stability, half-lives of VEGF mRNA were measured in A-172 cells cultured with or without 0.5 mM SNAP and treated with actinomycin D (25 microg/ml). Half-life for VEGF mRNA was found to be prolonged about 2.4 fold by SNAP. VEGF expression induced by SNAP was inhibited by guanylate cyclase inhibitors, methylene blue (10 microM) and LY-83583 (1 microM), and by the protein synthesis inhibitor, cycloheximide (25 microg/ml). These results suggest that induction of VEGF gene expression by NO is mediated through guanylate cyclase activity and requires on-going protein synthesis.
Assuntos
Carcinoma Hepatocelular/metabolismo , Fatores de Crescimento Endotelial/genética , Glioblastoma/metabolismo , Neoplasias Hepáticas/metabolismo , Linfocinas/genética , Óxido Nítrico/fisiologia , Cicloeximida/farmacologia , Fatores de Crescimento Endotelial/análise , Regulação da Expressão Gênica , Guanilato Ciclase/fisiologia , Humanos , Linfocinas/análise , RNA Mensageiro/análise , Células Tumorais Cultivadas , Fator A de Crescimento do Endotélio Vascular , Fatores de Crescimento do Endotélio VascularRESUMO
Nitric oxide (NO) is a newly identified, multifunctional biological mediator. However, it also has deleterious effects on biological materials. For instance, nucleic acids, proteins, and some prosthetic groups of enzymes can be modified by NO or its reaction products with other reactive oxygen species. Endogenous nitrosamine formation through the reaction of NO or its oxidized products with amines might be involved in carcinogenesis. These deleterious effects of NO are often associated with inflammatory processes both in experimental animals and human. We analyzed the molecular mechanism of control of expression of the inducible nitric oxide synthase (NOS) gene in mouse cells by cloning its putative promoter region. This promoter responded to various cytokines and endotoxin similarly to the endogenous NOS gene in mouse cells. No appreciable induction of NOS was observed in human peripheral blood cells, but induction was detected in a human glioblastoma cell line A-172. Therefore, the human inducible NOS cDNA was cloned from A-172 cells and its cDNA-deduced amino acid sequence found to have about 80% similarity to those of both mouse and rat inducible NOSs. The effects of various cytokines on the induction of the gene were somewhat different from those observed in mouse cells, but the mouse promoter responded to these cytokines similarly to the endogenous NOS gene in human cells, indicating functional similarity of cis-elements of the genes encoding both human and mouse inducible NOS. Structural analysis of the human inducible NOS gene by Southern blot analysis revealed putative genetic restriction fragment length polymorphism in intron 5.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Óxido Nítrico Sintase/biossíntese , Óxido Nítrico Sintase/genética , Regiões Promotoras Genéticas , Animais , Southern Blotting , Neoplasias Encefálicas , Linhagem Celular , Chlorocebus aethiops , Indução Enzimática , Feminino , Glioblastoma , Humanos , Luciferases/análise , Luciferases/biossíntese , Macrófagos , Camundongos , Placenta/enzimologia , Gravidez , RNA Mensageiro/análise , RNA Mensageiro/biossíntese , Proteínas Recombinantes/análise , Proteínas Recombinantes/biossíntese , Transfecção , Células Tumorais CultivadasRESUMO
The chronic toxicity of a new topical glucocorticoid, difluprednate (DFBA) was studied in Beagle dogs. DFBA ointment (0.05%) was percutaneously treated to the back of dogs at daily doses of 125, 12.5 and 1.25 micrograms/kg for 6 months. The local effects of DFBA In the treated area, thinning of the skin and inhibition of the fur-growth were observed with scale and erythema. The skin showed histological atrophy of the epidermis, a decrease of the adipose tissue and atrophy of the adnexa. These changes returned to normal after the 2-month withdrawal period. The systemic effects of DFBA In the 125 micrograms/kg group, the following changes were observed, although neither death nor severe symptoms occurred: General observations were seen an increase of water intake and urinary volume. A decrease of lymphocytes and eosinophils, and an increase of neutrophils were observed in the hematological examination. There were high sodium and low potassium levels, and an increase of alkaline phosphatase and gamma-glutamyltranspeptidase activities in the biochemical examination. The organ weights showed a decrease of the thymus, adrenals, prostate and ovaries, and an increase of the liver and kidney. An atrophy of the lymphatic tissues and adrenal cortex, retardation of the sexual maturation, glycogen deposit in the hepatic cells, slight degeneration of the renal tubuli, and slight thinning of the sternum and non-treated skin were noted in the pathological examination. These changes returned to normal after the 2-month withdrawal period. In the 12.5 micrograms/kg group, the atrophic changes in the thymus, adrenal and non-treated skin appeared slight. In the 1.25 micrograms/kg group, no changes were found. Conclusively, all the local and systemic changes observed by DFBA in this study were due to the already known pharmacological effects of glucocorticoids. It is considered that a 12.5 micrograms/kg dosage is similar to a non-effect dose.
Assuntos
Fluprednisolona/análogos & derivados , Pele/efeitos dos fármacos , Animais , Análise Química do Sangue , Peso Corporal/efeitos dos fármacos , Sistema Digestório/patologia , Cães , Ingestão de Líquidos/efeitos dos fármacos , Ingestão de Alimentos/efeitos dos fármacos , Glândulas Endócrinas/patologia , Feminino , Fluprednisolona/administração & dosagem , Fluprednisolona/toxicidade , Cabelo/efeitos dos fármacos , Testes Hematológicos , Sistema Linfático/patologia , Masculino , Pomadas , Tamanho do Órgão/efeitos dos fármacos , Pele/patologia , Fatores de TempoRESUMO
There are two major approaches to basilar top aneurysm: one is subtemporal by Drake, another is pterional by Yasargil. In either approach, however, it is hazardous and difficult to approach basilar top aneurysm with megadolichobasilar anomaly because strong retraction of brain, nerve and vessel is required. A successful case of ruptured basilar top aneurysm with megadolichobasilar anomaly treated directly through the third ventricle is reported. A 62-year-old woman was admitted with consciousness disturbance. Plain CT scan on admission demonstrated massive and diffuse subarachnoid hemorrhage and a clot in the third ventricle. The left vertebral angiography demonstrated a 5 X 5 mm basilar top aneurysm with megadolichobasilar anomaly 24 mm distant from dorsum sellae. The aneurysm was considered to be inaccessible by conventional approaches because of its high position. Therefore, we have applied a new approach mentioned below. Operation was performed 2 days after the onset, using a bifrontal craniotomy. Dissecting interhemispheric fissure, we approached the third ventricle via lamina terminalis. Evacuating the clot in the third ventricle, the basilar top aneurysm was visualized. After dissecting the neck of aneurysm and perforators, clipping was performed. The postoperative course was uneventful. Surgical key points and prospective view in approaching via lamina terminalis and through the third ventricle for a high position basilar top aneurysm are discussed.
Assuntos
Artéria Basilar , Aneurisma Intracraniano/cirurgia , Hemorragia Subaracnóidea/cirurgia , Artéria Basilar/anormalidades , Artéria Basilar/patologia , Feminino , Humanos , Aneurisma Intracraniano/complicações , Aneurisma Intracraniano/patologia , Pessoa de Meia-IdadeAssuntos
Carboxiliases/análise , Hidroliases/análise , Ácidos Levulínicos/metabolismo , Ligases/análise , Oxirredução , Rodopseudomonas/enzimologia , Aminoácidos/metabolismo , Antibacterianos/farmacologia , Proteínas de Bactérias/metabolismo , Clorofila , Meios de Cultura , Luz , Fenilalanina/farmacologia , Rodopseudomonas/citologia , Rodopseudomonas/crescimento & desenvolvimento , Rodopseudomonas/metabolismo , Fatores de TempoAssuntos
Encefalopatias/terapia , Corpos Estranhos/terapia , Magnetismo , Cobalto , Humanos , Ferro , Masculino , Pessoa de Meia-Idade , PlatinaRESUMO
Human nitrosating capacity has been monitored using proline; however, N-nitrosothiazolidine 4-carboxylic acid (NTCA; N-nitrosothioproline), one of the predominant N-nitroso compounds in human urine, is also nonmutagenic and, presumably, noncarcinogenic. Thioproline is nitrosated about 1000 times faster than proline in vitro, and NTCA is excreted into the urine without being metabolized. We have therefore proposed thioproline as an effective nitrite-trapping agent in the human body. Recently, we found thioproline in various cooked foods, including cod and dried shiitake mushrooms. In the study reported here, we evaluate the nitrite trapping capacity of thioproline in a male nonsmoking volunteer ingesting NO3- and eating a controlled diet. The highest level of NTCA excreted, 5.89 mumol, was measured after the subject ingested 6 mmol NO3- followed by 0.45 mmol (60 mg) thioproline. We estimated the effective amount of nitrite, defined as the actual amount of nitrite participating in nitrosation in the stomach, to be 0.3% of the NO3- ingested. Thus, the effective amount of NO2- for 6 mmol NO3- ingested was calculated to be 18 mumol, and 33% of this nitrite was trapped by ingestion of 0.45 mmol thioproline. We conclude that thioproline is a most sensitive probe for evaluating human nitrosating capacity and an effective nitrite-trapping agent.
Assuntos
Nitritos/metabolismo , Tiazóis/metabolismo , Ácido Ascórbico/farmacologia , Humanos , Compostos Nitrosos/urina , Tiazóis/urina , Tiazolidinas , Tiocianatos/farmacologiaRESUMO
Marked formation of N-nitrosothioproline (N-nitrosothiazolidine-4-carboxylic acid) by stimulation with Escherichia coli lipopolysaccharide (LPS) was demonstrated in ascorbic acid-deficient mutant rats (osteogenic disorder syndrome rats; ODS rats) unable to synthesize ascorbic acid. The amounts of urinary nitrate and N-nitrosothioproline excretion after thioproline administration was measured in ODS rats with and without ascorbic acid supplement before and after the injection of LPS. LPS caused marked increase of urinary nitrate excretion in both groups. Urinary N-nitrosothioproline excretion increased 6-fold after LPS injection in ODS rats not supplied with ascorbic acid, but supplement with ascorbic acid markedly decreased the excretion of N-nitrosothioproline.
Assuntos
Deficiência de Ácido Ascórbico/fisiopatologia , Ácido Ascórbico/metabolismo , Lipopolissacarídeos/farmacologia , Nitratos/urina , Compostos Nitrosos/urina , Tiazóis/urina , Glândulas Suprarrenais/metabolismo , Animais , Deficiência de Ácido Ascórbico/urina , Peso Corporal , Doenças Ósseas Metabólicas/genética , Escherichia coli , Feminino , Rim/metabolismo , Fígado/metabolismo , Ratos , Ratos Mutantes , Baço/metabolismo , TiazolidinasRESUMO
Nitric oxide (NO), generated from L-arginine by an enzymatic reaction of a NO synthase (NOS; EC 1.14.23), is a recently identified biological mediator suggested to be involved in a wide variety of biological processes. In the present work, we isolated and sequenced the entire region of cDNAs encoding mouse neuronal NOS (n-NOS) and demonstrated structural diversity of n-NOS mRNA in the nervous system. Sequence determination revealed a novel mRNA with an inframe deletion in the middle of the n-NOS cDNA. Structural analysis of the corresponding part of the n-NOS gene indicated that the deletion corresponded exactly to two exons. These findings suggest that the variant n-NOS is formed by alternative splicing. Both n-NOSs were found in almost all parts of the nervous system, the expression level of the novel variant being about one twentieth of that of the known n-NOS. Generation of diversity of n-NOS is probably related to diversity of its biological functions.
Assuntos
Aminoácido Oxirredutases/biossíntese , Aminoácido Oxirredutases/genética , Encéfalo/enzimologia , Variação Genética , Neurônios/enzimologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Medula Espinal/enzimologia , Sequência de Aminoácidos , Animais , Sequência de Bases , Clonagem Molecular , Biblioteca Gênica , Camundongos , Camundongos Endogâmicos BALB C , Dados de Sequência Molecular , Óxido Nítrico Sintase , Oligodesoxirribonucleotídeos , Especificidade de Órgãos , Poli A/genética , Poli A/isolamento & purificação , Reação em Cadeia da Polimerase , RNA/genética , RNA/isolamento & purificaçãoRESUMO
Thioproline (Thiazolidine-4-carboxylic acid) and proline were nitrosated by stimulated mouse macrophages in vitro. A macrophage cell line (J774.1, 1.0 x 10(6)/well, 1 ml) was incubated with Escherichia coli lipopolysaccharide, interferon-gamma and thioproline (5 mM) or proline (5 mM). After 72 hr incubation at 37 degrees C, 4 microM N-nitrosothioproline was produced. The amount of N-nitrosoproline was much lower than that of N-nitrosothioproline. Thioproline and proline inhibited the formation of carcinogenic N-nitrosomorpholine. N-nitrosothioproline and N-nitrosoproline are found as major N-nitroso compounds in human urine. Macrophage mediated N-nitrosation may contribute to the formation of these N-nitrosamino acids in the human body.
Assuntos
Macrófagos/fisiologia , Nitrosaminas/metabolismo , Prolina/metabolismo , Tiazóis/metabolismo , Animais , Linhagem Celular Transformada , Ativação de Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Macrófagos/metabolismo , Camundongos , Morfolinas/metabolismo , Prolina/biossíntese , Prolina/farmacologia , Tiazóis/biossíntese , Tiazóis/farmacologia , TiazolidinasRESUMO
When human hepatocellular carcinoma Hep-G2 cells were treated with the NO-generating compounds, S-nitroso-N-acetyl-DL-penicillamine(SNAP) or (+/-)-(E)-4-ethyl-2-(E)-hydroxyimino]-5-nitroso-3-hexenamide, cells stopped growing. Most cells were found to be in either G1 or G2/M phase and the dye-exclusion test revealed that the cells were alive. Electron microscopic examination confirmed the integrity of cells and nuclei. Nuclear staining with the DNA-binding dye H33258 revealed that cells did not undergo apoptosis although dramatic changes in mitochondrial morphology were noticed within 6 hr of treatment with SNAP by electron microscopy. Western and northern blot analysesrevealed that cells overexpressed p21/WAF1. The growth arrest was released by withdrawal of the NO-generating compound and cells started to divide within 24 hr after withdrawal of the compounds.
RESUMO
Expression of nitric oxide synthase (NOS) was studied in nine human neuroblastoma and two human glioblastoma cell lines. Neuronal NOS (n-NOS) mRNA of approximately 10 kb was detected in four of the nine neuroblastoma cell lines by northern blot analysis using human n-NOS cDNA as a probe. Expression of the n-NOS mRNA was also detected in another neuroblastoma cell line in a subsequent reverse transcriptase polymerase chain reaction (RT-PCR) study, but no n-NOS mRNA expression was observed in the other four neuroblastoma cell lines or in the glioblastoma cell lines. The level of NOS activity correlated well with that of n-NOS mRNA expression in neuroblastoma cell lines expressing n-NOS mRNA. Western blot analysis showed that the n-NOS expressed in neuroblastoma cells was a 160-kDa protein reacted with anti-n-NOS antibody. By using the RT-PCR method, a short n-NOS (n-NOS-2) mRNA with a 315-bp inframe deletion from the entire n-NOS (n-NOS-1) mRNA was detected in the human neuroblastoma cells. The structural diversity of human n-NOS mRNA was demonstrated for the first time.
Assuntos
Aminoácido Oxirredutases/genética , Neuroblastoma/química , Neuroblastoma/patologia , RNA Mensageiro/análise , Aminoácido Oxirredutases/análise , Aminoácido Oxirredutases/fisiologia , Sequência de Aminoácidos , Sequência de Bases , Southern Blotting , Western Blotting , DNA de Neoplasias/análise , DNA de Neoplasias/genética , Glioblastoma/química , Glioblastoma/enzimologia , Glioblastoma/patologia , Humanos , Dados de Sequência Molecular , Neuroblastoma/enzimologia , Óxido Nítrico Sintase , Reação em Cadeia da Polimerase , RNA Mensageiro/genética , Células Tumorais CultivadasRESUMO
Urinary excretions of nitrate and N-nitrosothiazolidine-4-carboxylic acid (N-nitrosothioproline; NTPRO) were determined in rats with osteogenic disordered syndrome (ODS, od/od), lacking L-ascorbic acid (ASC) biosynthesis, after i.p. administration of Escherichia coli lipopolysaccharide (LPS, 1 mg/kg) followed by thiazolidine-4-carboxylic acid (thioproline, 20 mg/rat). L-Ascorbic acid-sufficient ODS rats showed the excretion of nitrate and NTPRO at the levels of 20.3 +/- 7.9 mumol/24h and 369 +/- 111 pmol/24 h respectively, whereas the levels of nitrate and NTPRO in ASC-deficient (scorbutic) rats increased to 54.7 +/- 5.6 mumol/24 h (P < 0.01) and 796 +/- 367 pmol/24 h (P < 0.05) respectively. Administration of L-arginine further increased urinary excretion of nitrate and NTPRO while D-arginine showed no effect. NG-Monomethyl-L-arginine, a specific inhibitor of nitric oxide synthase (NOS), strongly inhibited endogenous formation of both nitrate and NTPRO. These results indicate that increased excretion of NTPRO in ODS rats stimulated by LPS involves induction of NOS leading to an increase in endogenous formation of reactive nitrogen oxides such as N2O3, a potent nitrosating agent at physiological pH conditions. Increased NOS activities in the plasma and various tissues of ODS rats were observed 5 h after treatment with LPS. The possibility of extragastric N-nitroso compound formation in inflammation sites is discussed.
Assuntos
Deficiência de Ácido Ascórbico/urina , Doenças Ósseas/urina , Lipopolissacarídeos/farmacologia , Nitratos/urina , Compostos Nitrosos/urina , Tiazóis/farmacologia , Tiazóis/urina , Animais , Ácido Ascórbico/farmacologia , Feminino , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase/biossíntese , Ratos , TiazolidinasRESUMO
To clarify a significant relationship between superoxide dismutase (SOD) and nitric oxide synthase (NOS) in the developing human brain temporospatially, we demonstrate immunohistochemical expression of Cu/Zn-binding SOD1 (SOD1), Mn-containing SOD2 (SOD2), neuronal NOS (nNOS), inducible NOS (iNOS), and nitrotyrosine in human brains from 13 weeks of gestation to 2 years after birth. The immunoreactivities of both SOD1 and SOD2 were detected in fetal neuroblasts at 13 weeks' gestation, as well as mature neurons at the age of 2 years. By contrast, nNOS neurons could be recognized only at 28 and 33 weeks of gestation in the cerebrum, and only at 15, 18, and 23 weeks of gestation in the brain stem. No significant immunoreactivity for iNOS or nitrotyrosine was detected in any type of cell in any region during any stage examined. Immunoblotting analysis using frontal tissue homogenates at 15, 28, 40 weeks of gestation and 18 months of age revealed single band corresponding to SOD1 molecular weight, observed at all stages examined; a single band compatible with the nNOS molecular mass was detected only at the 28th week of gestation. Together with the fact that nitric oxide (NO) plays a potential role in neuronal differentiation, and that large amounts of NO have cytotoxicity from the reaction of NO with superoxide anions, our data suggested that the expressions of both SOD1 and SOD2, as scavengers of superoxide anions, were maintained from an early developmental stage to prepare stage-specific nNOS expression for a potential differentiation role and to elude NO cytotoxicity.
Assuntos
Envelhecimento/metabolismo , Encéfalo/enzimologia , Diferenciação Celular/fisiologia , Neurônios/enzimologia , Óxido Nítrico Sintase/metabolismo , Superóxido Dismutase/metabolismo , Encéfalo/crescimento & desenvolvimento , Pré-Escolar , Feminino , Feto , Radicais Livres/metabolismo , Humanos , Imuno-Histoquímica , Lactente , Recém-Nascido , Doenças Neurodegenerativas/enzimologia , Doenças Neurodegenerativas/fisiopatologia , Neurônios/citologia , Estresse Oxidativo/fisiologia , Gravidez , Células-Tronco/citologia , Células-Tronco/enzimologia , Superóxido Dismutase-1RESUMO
Transcription of hypoxia-inducible genes is regulated by hypoxia response elements (HREs) located in either the promoter or enhancer regions. Analysis of these elements reveals the presence of one or more binding sites for hypoxia-inducible factor 1 (HIF-1). Hypoxia-inducible genes include vascular endothelial growth factor (VEGF), erythropoietin, and glycolytic enzyme genes. Site-directed mutational analysis of the VEGF gene promoter revealed that an HIF-1 binding site (HBS) and its downstream HIF-1 ancillary sequence (HAS) within the HRE are required as cis-elements for the transcriptional activation of VEGF by either hypoxia or nitric oxide (NO). The core sequences of the HBS and the HAS were determined as TACGTG and CAGGT, respectively. These elements form an imperfect inverted repeat, and the spacing between these motifs is crucial for activity of the promoter. Gel shift assays demonstrate that as yet unknown protein complexes constitutively bind to the HAS regardless of the presence of these stimuli in several cell lines, in contrast with hypoxia- or NO-induced activation of HIF-1 binding to the HBS. A common structure of the HRE, which consists of the HBS and the HAS, is seen among several hypoxia-inducible genes, suggesting the presence of a novel mechanism mediated by the HAS for the regulation of these genes.