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1.
Acute Med Surg ; 8(1): e705, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34804555

RESUMO

BACKGROUND: Infections caused by Corynebacterium ulcerans, a zoonotic pathogen, have been reported worldwide. This microorganism is known to produce the diphtheria toxin and cause diphtheria-like illness. CASE PRESENTATION: A 63-year-old woman with a history of diabetes and hypertension developed cold and flu-like symptoms, which gradually progressed into respiratory distress. Therefore, the patient was intubated for dyspnea with pseudomembrane formation. A toxin-producing strain of C. ulcerans was identified, also detected in the patient's domestic cats. Multilocus sequence typing confirmed all strains, including the patient's isolate, as ST337. CONCLUSION: Multilocus sequence typing revealed zoonotic transmission of C. ulcerans from domestic cats to a human.

2.
J Clin Biochem Nutr ; 67(2): 199-205, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33041518

RESUMO

Some patients with interstitial pneumonia (IP) have auto-antibodies, but do not fit the criteria for specific connective tissue diseases. Examination of auto-antibodies is recommended for diagnosis idiopathic pulmonary fibrosis. A prospective cohort study was performed in 285 patients with IP. Eleven auto-antibodies were assessed and patients were followed for 2 years. All 285 patients underwent the myositis panel test (MPT) for 11 auto-antibodies. Among them, 23.5% (67/285) of the patients had a positive MPT and 14.7% (42/285) had connective tissue diseases. Among the 49 MPT positive patients without connective tissue diseases, 29 patients (59.2%) were positive for Ro52, including 17 patients with Ro52 mono-positivity. Among interstitial pneumonia patients without connective tissue diseases, the Ro52 mono-positive patients showed worse at 2-years survival than those who were Ro52 negative (p = 0.022, HR = 5.88, 95% CI 1.29-26.75). Most of the Ro52 positive patients also showed a low titer of anti-nucleolar antibody. About 20% of IP patients had auto-antibodies detectable by the MPT, and Ro52 positive patients accounted for more than half of the MPT positive patients without connective tissue diseases. Detection of Ro52 auto-antibodies may be useful for assessing the risk of progression in idiopathic interstitial pneumonia patients without connective tissue diseases and a low anti-nucleolar antibody titer.

3.
J Biosci Bioeng ; 126(5): 580-585, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29871825

RESUMO

FK506 (tacrolimus), a macrolide compound with immunosuppressant activity, has been shown to be of clinical importance and has been manufactured industrially since 1993 using mutants with high FK506 production ability. These mutants have been developed from the wild strain Streptomyces tsukubaensis No. 9993. FR900525 is one of the by-products of FK506 production, and we previously established a mutant strain that produces reduced levels of FR900525 by selecting for S-(2-aminoethyl) l-cysteine (AEC) resistance. In this study, we conducted a genomic analysis of this strain to identify the changes associated with AEC resistance and to determine its metabolism. Three mutated genes were identified by comparing the genome sequences of the parental strain (A) and the AEC-resistant mutant (B). From the metabolite pathway, it was speculated that citric acid synthase was the most relevant to AEC resistance. To investigate the effect of the mutation in citric acid synthase, we added citric acid, an inhibitor of citric acid synthase, to strain A culture, which induced strain A to exhibit a strain B-like phenotype. We conclude that the mutation in citric acid synthase enhances the carbon flow into aspartic acid, increasing lysine synthesis and resulting in AEC resistance in strain B, as well as high production of FK506 and low production of FR900525.


Assuntos
Cisteína/análogos & derivados , Resistência a Medicamentos/genética , Imunossupressores/metabolismo , Macrolídeos/farmacologia , Streptomyces/genética , Cisteína/farmacologia , Regulação Bacteriana da Expressão Gênica , Genoma Bacteriano , Genômica/métodos , Imunossupressores/farmacologia , Organismos Geneticamente Modificados , Streptomyces/metabolismo , Tacrolimo/metabolismo
4.
Sci Rep ; 7(1): 10242, 2017 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-28860648

RESUMO

To examine the change in stress between before and after the Tohoku-oki Mw9.0 earthquake, we performed stress measurements after the earthquake in the Kamaishi mine in Iwate prefecture in northern Japan, located near the northern termination of the mainshock rupture, following previous measurements before the earthquake in the same mine. The results showed that the magnitudes of the three-dimensional principal stresses and the vertical stress drastically increased after the mainshock and, at 1 year after the earthquake, were more than double those before the earthquake. The principal stress magnitudes then decreased with time and returned to almost pre-earthquake levels at about 3 years after the earthquake. These changes can be interpreted in terms of coseismic rupture of the mainshock and the occurrence of aftershocks in the Sanriku-oki low-seismicity region (SLSR), where the Kamaishi mine is located. The drastic increase in stress suggests that the SLSR may act as a barrier to further rupture propagation.

5.
J Biosci Bioeng ; 124(1): 8-14, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28341398

RESUMO

FR901469 is a secondary metabolite with antifungal activity, produced by fungal sp. No. 11243. In our previous study, we constructed the frbF overexpression mutant (TFH2-2) from the wild-type strain. FR901469 productivity of TFH2-2 was 3.4 times higher than that of the wild-type strain. To further enhance FR901469 productivity in TFH2-2, we attempted to find genes from the genome that limited the productivity as bottlenecks in this study. Based on both correlation analysis of gene expression level against FR901469 productivity and genome annotation information, the cross-pathway control gene A (cpcA) was most predicted as the bottleneck. The cpcA and frbF co-overexpression mutant named TFCH3 was then constructed from TFH2-2. As a result, FR901469 productivity of TFCH3 was enhanced at 1.8 times higher than that of TFH2-2. Transcriptome analysis revealed that many genes involved in amino acid biosynthesis and encoding tRNA ligases were significantly upregulated in TFCH3, which implied increase of amino acids as the substrates of FR901469 would be a reason of further productivity enhancement.


Assuntos
Antifúngicos/metabolismo , Depsipeptídeos/biossíntese , Fungos/genética , Genes Fúngicos/genética , Engenharia Genética/métodos , Expressão Gênica , Mutação
6.
J Biosci Bioeng ; 123(6): 685-691, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28185832

RESUMO

FK506 (tacrolimus), a macrolide compound with immunosuppressant activity, has been proven to have clinical importance and has been manufactured industrially since 1993 by using mutants with high FK506-production ability; these mutants have been developed from the wild strain Streptomyces tsukubaensis No. 9993. FR900525 is one of the by-products of FK506 production. However, there was no effective industrial method to separate FR900525 from FK506 due to the structural similarity between the two compounds. Therefore, reducing the level of FR900525 was a serious problem in the industrial strain A. In this study, we aimed to reduce the FR900525 production. We first determined that pipecolic acid level was a critical parameter for controlling FR900525 production in strain A. S-(2-Aminoethyl) l-cysteine (AEC)-resistant mutants has been reported to increase lysine productivity successfully in a variety of lysine-producing microorganisms. Therefore, next, we applied a selection of AEC-resistant mutants to enhance pipecolic acid biosynthesis. Finally, four AEC-resistant mutants were obtained from strain A using ultraviolet irradiation, and three of them showed less FR900525 productivity compared to the parental strain A. Our findings indicated that AEC resistance was effective phenotype marker for increasing pipecolic acid productivity and for reducing FR900525 production in S. tsukubaensis. Thus, our study provides an efficient method for reducing FR90025 level during FK506 biosynthesis.


Assuntos
Cisteína/análogos & derivados , Mutação , Streptomyces/genética , Streptomyces/metabolismo , Tacrolimo/análogos & derivados , Cisteína/farmacologia , Oxirredução , Streptomyces/efeitos dos fármacos , Streptomyces/efeitos da radiação , Tacrolimo/metabolismo , Raios Ultravioleta
7.
J Biosci Bioeng ; 123(2): 147-153, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27660098

RESUMO

FR901469 is an antifungal antibiotic produced by fungal sp. No. 11243. Here, we searched for FR901469 biosynthesis genes in the genome of No. 11243. Based on the molecular structure of FR901469 and endogenous functional motifs predicted in each genomic NRPS gene, a putative FR901469 biosynthesis gene cluster harboring the most plausible NRPS gene was identified. A transcription factor gene, designated frbF, was found in the cluster. To improve FR901469 productivity, we constructed a strain in which frbF was overexpressed and named it TFH2-2. FR901469 productivity of TFH2-2 was 3.4 times higher than that of the wild-type strain. Transcriptome analysis revealed that most of the genes in the putative FR901469 biosynthesis gene cluster were upregulated in TFH2-2. It also showed that the expression of genes related to ergosterol biosynthesis, ß-1,3-glucan catabolism, and chitin synthesis was inclined to exhibit significant differences in TFH2-2.


Assuntos
Depsipeptídeos/biossíntese , Regulação Fúngica da Expressão Gênica , Redes e Vias Metabólicas/genética , Família Multigênica , Fatores de Transcrição/genética , Sequência de Aminoácidos , Antifúngicos/metabolismo , Clonagem Molecular , Proteínas Fúngicas/genética , Perfilação da Expressão Gênica , Regulação para Cima/genética
8.
Biol Pharm Bull ; 39(3): 435-9, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26934934

RESUMO

A soluble form of human intestinal lactoferrin receptor (shLFR) is identical to human intelectin-1 (hITLN-1), a galactofuranose-binding protein that acts as a host defense against invading pathogenic microorganisms. We found that recombinant shLFR, expressed in mammalian cells (CHO DG44, COS-1, and RK13), binds tightly to Sepharose 4 Fast Flow (FF)-based matrices in a Ca(2+)-dependent manner. This binding of shLFR to Sepharose 4 FF-based matrices was inhibited by excess D-galactose, but not by D-glucose, suggesting that shLFR recognizes repeating units of α-1,6-linked D-galactose in Sepharose 4 FF. Furthermore, shLFR could bind to both Sepharose 4B- and Sepharose 6B-based matrices that were not crosslinked in a similar manner as to Sepharose 4 FF-based matrices. Therefore, shLFR (hITLN-1) binds to Sepharose-based matrices in a Ca(2+)-dependent manner. This binding property is most likely related to the ability, as host defense lectins, to recognize sepharose (agarobiose)-like structures present on the surface of invading pathogenic microorganisms.


Assuntos
Cálcio/metabolismo , Receptores de Superfície Celular/metabolismo , Sefarose/metabolismo , Animais , Células CHO , Células COS , Linhagem Celular , Chlorocebus aethiops , Cricetulus , Humanos , Intestinos , Ligação Proteica , Coelhos , Receptores de Superfície Celular/genética , Proteínas Recombinantes/metabolismo
9.
J Appl Glycosci (1999) ; 63(2): 31-37, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-34354480

RESUMO

Five kinds of fucoidans from the brown seaweeds Cladosiphon okamuranus, Sargassum hornery, Kjellmaniella crassifolia (Saccharine sculpera), Nemacystus decipiens, and Fucus vesiculosus, were isolated according to a previously reported procedure with slight modification. The scavenging activities of DPPH radical, superoxide radical, and hydroxyl radical, as well as the ORAC value were measured for the isolated fucoidans. Fucoidans from S. hornery, F. vesiculosus, and K. crassifolia showed higher antioxidant activity than that from S. hornery and C. okamuranus, except for the hydroxyl radical scavenging activity. The relationship between the antioxidant activity and the structure was examined for each fucoidan. Fucoidans with high amount of sulfate groups did not necessarily result in increased antioxidant activity, although the sulfate group itself was essential for the antioxidant activity. Furthermore, the fucoidan linked to a side chain monosaccharide, such as GlcA, demonstrated similar antioxidant activity. The antioxidant activity of the fucoidans was possibly due to a combination of the factors involved, such as the amount of sulfate groups, the position of the sulfate groups, the kind of side chain sugar, the linkage of a side chain sugar, and the molecular weight.

10.
Genome Announc ; 3(2)2015 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-25838475

RESUMO

Fungal species No.11243 was originally isolated from a decayed leaf sample collected in Kyoto, Japan. It produces FR901469, a 1,3-beta-glucan synthase inhibitor. The genome sequence of No.11243 was determined and annotated to obtain useful information for improving productivity of the effective antifungal agent FR901469.

11.
Asia Pac Allergy ; 5(1): 55-6, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25653922

RESUMO

We report a rare case of anaphylaxis due to caffeine intake. A 27-year-old woman suffered her first episode of anaphylaxis and a positive skin prick test suggested that the anaphylaxis was due to an IgE-mediated hypersensitivity reaction to caffeine. She was diagnosed with caffeine allergy and has not had an allergic reaction after avoiding foods and drinks containing caffeine. Although caffeine is known to have antiallergic effects, this case shows that caffeine can be an allergen and cause anaphylaxis.

12.
Allergol Int ; 63(1): 21-6, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24270224

RESUMO

BACKGROUND: Forestry and field workers who work outdoors are at high risk for Hymenoptera stings and may develop occupation-related allergies from being stung. However, clinical and immunological surveys of Hymenoptera stings in the occupational setting have rarely been reported. We surveyed the natural history of Hymenoptera stings in Japanese forestry workers (FWs) and electrical facility field workers (EFFWs), and we assessed the utility of measuring specific (s)IgE Ab to Hymenptera venom. METHODS: Questionnaires on hornet and paper wasp stings were completed by 999 FWs, 354 EFFWs, and 365 office workers as controls between July and November 2009. Sera from these participants were tested for sIgE Ab levels to Hymenptera venom with a CAP system using a fluoroenzyme immunoassay. RESULTS: Of the participants who had experienced Hymenoptera stings, 914 (91.5%) were FWs, 293 (82.8%) were EFFWs, and 295 (80.8%) were controls. Of the participants who had experienced systemic reactions, 210 (21.0%) were FWs, 51 (14.4%) were EFFWs, and 39 (10.7%) were controls. sIgE Ab in response to hornet and wasp venom was positive (≥ class 2) in 42.4% and 41.4% of FWs, 30.1% and 31.4% of EFFWs, and 15.1% and 18.1% of controls, respectively. The likelihood of being sIgE-positive to wasp and hornet venom was significantly higher in FWs and EFFWs than in controls (P < 0.05). CONCLUSIONS: 21% of FWs and 14% of EFFWs had experienced systemic reactions to Hymenoptera stings with a higher frequency compared with office workers in the same area. 40% of FWs and 30% of EFFWs had sera that were sIgE positive to Hymenoptera venom.


Assuntos
Agricultura Florestal , Mordeduras e Picadas de Insetos/epidemiologia , Centrais Elétricas , Venenos de Abelha/imunologia , Inquéritos Epidemiológicos , Humanos , Imunoglobulina E/sangue , Imunoglobulina E/imunologia , Mordeduras e Picadas de Insetos/sangue , Mordeduras e Picadas de Insetos/imunologia , Japão/epidemiologia , Inquéritos e Questionários , Venenos de Vespas/imunologia , Local de Trabalho
13.
Allergol Int ; 63(1): 21-26, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-28942981

RESUMO

BACKGROUND: Forestry and field workers who work outdoors are at high risk for Hymenoptera stings and may develop occupation-related allergies from being stung. However, clinical and immunological surveys of Hymenoptera stings in the occupational setting have rarely been reported. We surveyed the natural history of Hymenoptera stings in Japanese forestry workers (FWs) and electrical facility field workers (EFFWs), and we assessed the utility of measuring specific (s)IgE Ab to Hymenptera venom. METHODS: Questionnaires on hornet and paper wasp stings were completed by 999 FWs, 354 EFFWs, and 365 office workers as controls between July and November 2009. Sera from these participants were tested for sIgE Ab levels to Hymenptera venom with a CAP system using a fluoroenzyme immunoassay. RESULTS: Of the participants who had experienced Hymenoptera stings, 914 (91.5%) were FWs, 293 (82.8%) were EFFWs, and 295 (80.8%) were controls. Of the participants who had experienced systemic reactions, 210 (21.0%) were FWs, 51 (14.4%) were EFFWs, and 39 (10.7%) were controls. sIgE Ab in response to hornet and wasp venom was positive (≥ class 2) in 42.4% and 41.4% of FWs, 30.1% and 31.4% of EFFWs, and 15.1% and 18.1% of controls, respectively. The likelihood of being sIgE-positive to wasp and hornet venom was significantly higher in FWs and EFFWs than in controls (P < 0.05). CONCLUSIONS: 21% of FWs and 14% of EFFWs had experienced systemic reactions to Hymenoptera stings with a higher frequency compared with office workers in the same area. 40% of FWs and 30% of EFFWs had sera that were sIgE positive to Hymenoptera venom.

14.
J Agric Food Chem ; 57(8): 3102-7, 2009 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-19309147

RESUMO

A detailed analysis of the antioxidative activity of 12 carbohydrates including chondroitin sulfate, fucoidan, agaro-oligosaccharide, 2-deoxy-scyllo-inosose (DOI), Galbeta1-4DOI, D-glucuronic acid, chitobiose, D-mannosamine, D-galactosamine, D-glucosamine, heparin, and colominic acid was performed using four established methods: 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay, ferric reducing antioxidant power (FRAP) assay, superoxide dismutase (SOD) activity assay, and the deoxyribose method. Ascorbic acid and/or catechin were used as positive standards. In the DPPH radical scavenging activity measurements, fucoidan, DOI, and Galbeta1-4DOI showed remarkable levels of activity, although at lower levels than ascorbic acid. The SOD assay revealed that DOI, Galbeta1-4DOI, and agaro-oligosaccharide had high antioxidant activity, with DOI and Galbeta1-4DOI notably showing almost half of the antioxidative potency of ascorbic acid. Using the deoxyribose method, chitobiose and heparin showed the highest hydroxyl radical scavenging activity, followed by chondroitin sulfate, colominic acid, Galbeta1-4DOI, and d-glucosamine. Given that 11 of the carbohydrates analyzed share a common structure, agaro-oligosaccharide being the exception, we propose from our current results that at least one amino, carboxyl, carbonyl, or sulfonyl group is required, but is not in itself sufficient, for carbohydrates to function as antioxidants.


Assuntos
Antioxidantes/farmacologia , Carboidratos/farmacologia , Polissacarídeos/farmacologia , Compostos de Bifenilo , Carboidratos/química , Desoxirribose , Compostos Férricos/química , Sequestradores de Radicais Livres/farmacologia , Picratos , Polissacarídeos/química , Relação Estrutura-Atividade , Superóxido Dismutase
15.
Biochem J ; 376(Pt 3): 655-66, 2003 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-12967323

RESUMO

sPLA(2)s (secretory phospholipases A(2)) belong to a broad and structurally diverse family of enzymes that hydrolyse the sn -2 ester bond of glycerophospholipids. We previously showed that a secreted fungal 15 kDa protein, named p15, as well as its orthologue from Streptomyces coelicolor (named Scp15) induce neurite outgrowth in PC12 cells at nanomolar concentrations. We report here that both p15 and Scp15 are members of a newly identified group of fungal/bacterial sPLA(2)s. The phospholipid-hydrolysing activity of p15 is absolutely required for neurite outgrowth induction. Mutants with a reduced PLA(2) activity exhibited a comparable reduction in neurite-inducing activity, and the ability to induce neurites closely matched the capacity of various p15 forms to promote fatty acid release from live PC12 cells. A structurally divergent member of the sPLA(2) family, bee venom sPLA(2), also induced neurites in a phospholipase activity-dependent manner, and the same effect was elicited by mouse group V and X sPLA(2)s, but not by group IB and IIA sPLA(2)s. Lysophosphatidylcholine, but not other lysophospholipids, nor arachidonic acid, elicited neurite outgrowth in an L-type Ca(2+) channel activity-dependent manner. In addition, p15-induced neuritogenesis was unaffected by various inhibitors that block arachidonic acid conversion into bioactive eicosanoids. Altogether, these results delineate a novel, Ca(2+)- and lysophosphatidylcholine-dependent neurotrophin-like role of sPLA(2)s in the nervous system.


Assuntos
Neuritos/ultraestrutura , Neurônios/citologia , Fosfolipases A/farmacologia , Sequência de Aminoácidos , Animais , Proteínas de Bactérias/metabolismo , Venenos de Abelha/enzimologia , Cálcio/farmacologia , Bovinos , Diferenciação Celular , Ácidos Graxos/metabolismo , Fungos/enzimologia , Camundongos , Dados de Sequência Molecular , Neuritos/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Células PC12 , Fosfolipases A/química , Fosfolipases A/metabolismo , Ratos , Alinhamento de Sequência
16.
Biosci Biotechnol Biochem ; 67(6): 1312-8, 2003 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12843659

RESUMO

The effect of neuronal cells on the functional properties of intestinal epithelial cells was examined by using an in vitro coculture system. Two cell lines, Caco-2 and PC12, were respectively used as intestinal epithelial and enteric neuronal cell models. Coculture of differentiated Caco-2 cells with PC12 caused a significant decrease in the transepithelial electrical resistance (TER) value of the Caco-2 monolayer. The permeability to lucifer yellow (LY) was also significantly increased, suggesting that the tight junction (TJ) of the Caco-2 monolayers was modulated by coculturing with PC12. To identify the TJ-modulating factor presumably secreted from PC12, the effects of the major neurotransmitters on the TER value and LY transport were examined, but no influence was apparent. The TJ-modulating effect of PC12 was prevented by exposing PC12 to cycloheximide, suggesting that new protein synthesis in PC12 was necessary for this regulation.


Assuntos
Mucosa Intestinal/citologia , Neurônios/citologia , Comunicação Parácrina , Animais , Células CACO-2 , Técnicas de Cocultura/métodos , Cicloeximida/farmacologia , Humanos , Neurônios/metabolismo , Neurotransmissores/farmacologia , Células PC12 , Permeabilidade , Biossíntese de Proteínas , Proteínas/fisiologia , Ratos , Junções Íntimas/efeitos dos fármacos , Junções Íntimas/metabolismo , Fatores de Tempo , Fator de Necrose Tumoral alfa/farmacologia
17.
Biosci Biotechnol Biochem ; 67(1): 77-82, 2003 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-12619676

RESUMO

We previously showed that a fungal protein, p15, induces neurite outgrowth and differentiation of rat pheochromocytoma PC12 cells. We report here the identification and characterization of a protein similar to p15, found in Streptomyces coelicolor A3(2). This hypothetical protein, tentatively named Scp15, has significant similarity with p15, including conserved positions of four cysteine residues involved in the formation of essential disulfide bonds in p15. Hexahistidine-tagged recombinant Scp15 proteins were produced in Escherichia coli, purified, and analyzed for their neurite-inducing activity. Although they were less active than p15, they dose-dependently induced neurites and the expression of neurofilament M. Neurite outgrowth by Scp15 was inhibited by nicardipine, suggesting that Scp15 induces neurites via activation of a calcium signaling pathway.


Assuntos
Proteínas de Bactérias/química , Neuritos/química , Streptomyces/química , Sequência de Aminoácidos , Animais , Western Blotting , Bloqueadores dos Canais de Cálcio/farmacologia , Clonagem Molecular , DNA Bacteriano/biossíntese , DNA Bacteriano/genética , Eletroforese em Gel de Poliacrilamida , Escherichia coli/efeitos dos fármacos , Escherichia coli/metabolismo , Dados de Sequência Molecular , Proteínas de Neurofilamentos/biossíntese , Proteínas de Neurofilamentos/isolamento & purificação , Nicardipino/farmacologia , Células PC12 , Ratos , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa
18.
Life Sci ; 72(11): 1247-57, 2003 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-12570925

RESUMO

Magnesium deficiency has been shown to increase nitric oxide (NO) levels in plasma and to aggravate endotoxin lethality. The present study was performed to examine the effects of magnesium (Mg(2+))-deficient culture medium, with and without endotoxin (LPS), on NO release and inducible NOS (iNOS) mRNA levels in alveolar macrophages isolated from rats. Decreasing the Mg(2+) concentration in the culture medium from 0.39 mM (normal-Mg(2+) medium) to 0.021 mM (Mg(2+)-deficient medium) increased NO release from alveolar macrophages for 2 h. However, LPS stimulation in Mg(2+)-deficient medium had little effect on NO release. The increased NO release in Mg(2+)-deficient medium was suppressed completely by L-NAME and aminoguanidine. Dexamethasone, pyrrolidine dithiocarbamate and curcumin strongly inhibited NO release. Verapamil, U73122, TMB-8 and W-7 had no significant effect on NO release induced by Mg(2+) deficiency. Preculture of macrophages with Mg(2+)-deficient medium for 22 h markedly increased NO release and iNOS mRNA levels for a further 2 h; these increments were suppressed completely by curcumin. These results suggest that Mg(2+) deficiency enhances NO production via iNOS by alveolar macrophages. In this experimental condition, we can not suggest that NO production from alveolar macrophage plays an essential role in the pathogenesis of enhanced endotoxin lethality in Mg-deficient rats.


Assuntos
Macrófagos Alveolares/metabolismo , Deficiência de Magnésio/metabolismo , Óxido Nítrico/biossíntese , Animais , Sinalização do Cálcio , Células Cultivadas , Meios de Cultura , Lipopolissacarídeos/farmacologia , Masculino , NG-Nitroarginina Metil Éster/farmacologia , Óxido Nítrico Sintase/genética , Óxido Nítrico Sintase Tipo II , Ratos
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