Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 11 de 11
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Mol Biol Rep ; 50(10): 8201-8212, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37561325

RESUMO

PURPOSE: We aimed to study insertion/deletion (I/D) variation (rs4646994) of ACE gene in a group of SLE patients in west of Iran and its possible relationship with oxidative stress. METHOD AND RESULTS: Genotypes and allele frequencies related to ACE (I/D) variation were determined in 108 SLE patients and 110 gender and age-matched healthy controls using PCR. Neopterin, malondialdehyde (MDA), and serum lipid concentrations were determined by HPLC and enzyme assay respectively. The overall distribution of ACE I/D genotypes in SLE patients was different from that of the control group (P = 0.005). DD genotype compared to ID genotype increased the risk of SLE (OR = 2.57, 95% CI 1.4-4.8, P = 0.003). ID genotype compared to the II genotype decreased the risk of disease (OR = 0.45, 95% CI 0.2-0.99, p = 0.042). SLE patients with DD, ID, and II genotypes had lower paraoxonase (PON) activity and higher serum levels of MDA and neopterin versus control patients. We also detected a significant protective effect against SLE in presence of ACE I alleles and lack of angiotensin II receptor, type 1 (AGTR1) A1166C (NCBI reference SNP id: rs5186), C alleles in this study (OR = 0.31, 95% CI 0.14-0.68, P = 0.002). CONCLUSIONS: Carriers of the DD genotype of ACE gene with higher serum concentrations of neopterin and MDA, and lower PON activity had a high risk to develop SLE, while ID genotype decreased the risk of disease development by 2.22 times compared to II genotype.


Assuntos
Lúpus Eritematoso Sistêmico , Humanos , Angiotensinas , Genótipo , Irã (Geográfico) , Lúpus Eritematoso Sistêmico/genética , Neopterina/genética , Estresse Oxidativo , Peptidil Dipeptidase A/genética
2.
Nutr Metab Cardiovasc Dis ; 32(6): 1502-1510, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35450790

RESUMO

BACKGROUND AND AIM: Childhood obesity is an emerging problem often leading to earlier onset of non-communicable diseases in later life. Biomarkers to identify individual risk scores are insufficient in routine clinical practice, which is related to the need for easily sampled, non-invasive survey methods in children. We aimed to investigate and strengthen possible pro-inflammatory markers and epigenetic risk factors in saliva of obese children compared to lean controls. METHODS AND RESULTS: 19 overweight/obese (OC, 10.1 ± 1.9 years, BMI 27.7 ± 3.2 kg/m2) and 19 lean control children (CC, 9.7 ± 2.5 years, BMI 16.4 ± 1.8 kg/m2) participated in this explorative pilot study. Anthropometric measures, saliva and cheek swab samples were taken. Saliva profiles were examined for acute phase proteins (CRP and neopterin) and pro-inflammatory cytokines (IL-17a/IL-1ß/IL-6). Cheek swabs were analyzed to investigate DNA methylation differences with subsequent hierarchical cluster and principal component analyses (PCA). Saliva analysis showed significant increased CRP concentrations in OC compared to CC (p < 0.001). There were no significant differences, but high intra-individual values in neopterin, IL-17a, IL-1ß and IL-6. An unsupervised PCA of CpG loci with high variance (σ/σmax > 0.2) clearly separated OC and CC according to their methylation pattern. Furthermore, a supervised approach revealed 7125 significantly differentially methylated loci, whose corresponding genes were significantly enriched for genes playing roles in e.g., cellular signalling, cytoskeleton organization and cell motility. CONCLUSIONS: CRP and methylation status determinations in saliva are suitable as non-invasive methods for early detection of risks for non-communicable diseases in children/adolescents and might be a useful supplementary approach in the routine clinical practice/monitoring.


Assuntos
Doenças não Transmissíveis , Obesidade Infantil , Adolescente , Biomarcadores/metabolismo , Criança , Marcadores Genéticos , Humanos , Interleucina-17/genética , Interleucina-17/metabolismo , Interleucina-6/genética , Interleucina-6/metabolismo , Neopterina/genética , Neopterina/metabolismo , Obesidade Infantil/diagnóstico , Obesidade Infantil/epidemiologia , Obesidade Infantil/genética , Projetos Piloto , Saliva/metabolismo
3.
J Neuroimmunol ; 360: 577715, 2021 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-34536787

RESUMO

This post-hoc analysis evaluated candidate biomarkers of long-term efficacy of subcutaneous interferon beta-1a (sc IFN ß-1a) in REFLEX/REFLEXION studies of clinically isolated syndrome. Samples from 507 REFLEX and 287 REFLEXION study participants were analyzed. All investigated biomarkers were significantly upregulated 1.5-4-fold in response to sc IFN ß-1a treatment versus baseline (p ≤ 0.008). The validity of MX1, 2'5'OAS, and IL-1RA as biomarkers of response to sc IFN ß-1a was confirmed in this large patient cohort, with biomarkers consistently upregulated in a dose-dependent manner. Neopterin, TRAIL, and IP-10 were confirmed as biomarkers associated with long-term sc IFN ß-1a treatment efficacy over 5 years.


Assuntos
Interferon beta-1a/uso terapêutico , Esclerose Múltipla/tratamento farmacológico , 2',5'-Oligoadenilato Sintetase/biossíntese , 2',5'-Oligoadenilato Sintetase/sangue , 2',5'-Oligoadenilato Sintetase/genética , Biomarcadores , Quimiocina CXCL10/biossíntese , Quimiocina CXCL10/sangue , Quimiocina CXCL10/genética , Relação Dose-Resposta a Droga , Método Duplo-Cego , Seguimentos , Humanos , Injeções Subcutâneas , Interferon beta-1a/administração & dosagem , Interferon beta-1a/farmacocinética , Proteína Antagonista do Receptor de Interleucina 1/biossíntese , Proteína Antagonista do Receptor de Interleucina 1/sangue , Proteína Antagonista do Receptor de Interleucina 1/genética , Estudos Multicêntricos como Assunto , Esclerose Múltipla/sangue , Proteínas de Resistência a Myxovirus/biossíntese , Proteínas de Resistência a Myxovirus/sangue , Proteínas de Resistência a Myxovirus/genética , Neopterina/biossíntese , Neopterina/sangue , Neopterina/genética , Ensaios Clínicos Controlados Aleatórios como Assunto/estatística & dados numéricos , Ligante Indutor de Apoptose Relacionado a TNF/biossíntese , Ligante Indutor de Apoptose Relacionado a TNF/sangue , Ligante Indutor de Apoptose Relacionado a TNF/genética , Regulação para Cima
4.
Can J Vet Res ; 84(3): 230-234, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32801459

RESUMO

The objective of this study was to determine serum concentrations of interferon-gamma (INF-γ) and neopterin (Np) in dogs with pyometra admitted for surgical treatment and to compare these concentrations to healthy dogs admitted for elective spay. The effects of the surgical procedure were also evaluated by measuring these markers in both groups of dogs before and after ovariohysterectomy. Our study indicates that pre-surgery concentrations of INF-γ (57.4 ± 26.0 pg/mL) and Np (5.6 ± 0.8 nmol/L) in healthy dogs were significantly lower compared to dogs with pyometra (124.3 ± 87.6 pg/mL for INF-γ; 7.0 ± 1.5 nmol/L for Np) (P < 0.05 in both cases). Furthermore, Np was lower in dogs with pyometra 3 days after surgery compared to healthy controls (P < 0.001). During the post-operative period, INF-γ showed no statistically significant changes in any of the groups, while Np showed lower serum concentration on day 3 than on day 0 in the pyometra group (P < 0.001). No statistically significant correlation was detected between serum concentrations of INF-γ and Np. These results indicate that pyometra causes alterations in serum concentrations of INF-γ and Np in female dogs compared to physiological levels before surgery and during the postoperative period.


L'objectif de la présente étude était de déterminer les concentrations sériques d'interféron gamma (INF-γ) et de néoptérine (Np) chez des chiens avec pyomètre admis pour traitement chirurgical et de comparer ces concentrations à celles de chiens en santé admis pour stérilisation élective. Les effets de la procédure chirurgicale furent également évalués en mesurant ces marqueurs dans les deux groupes de chiens avant et après ovariohystérectomie. Notre étude indique que les concentrations pré-chirurgie d'IFN-γ (57,4 ± 26,0 pg/mL) et de NP (5,6 ± 0,8 nmol/L) chez les chiens en santé étaient significativement inférieures comparativement aux chiens avec pyomètre (124,3 ± 87,6 pg/mL pour INF-γ; 7,0 ± 1,5 nmol/L pour Np) (P < 0,05 dans les deux cas). De plus, Np était plus bas chez les chiens avec pyomètre trois jours après la chirurgie comparativement aux témoins en santé (P < 0,001). Durant la période post-chirurgicale, INF-γ ne montra aucun changement statistiquement significatif dans aucun des trois groupes, alors que Np a présenté des concentrations sériques plus faibles au jour 3 qu'au jour 0 dans le groupe avec pyomètre (P < 0,001). Aucune corrélation statistiquement significative ne fut détectée entre les concentrations sériques d'INF-γ et de Np. Ces résultats indiquent que le pyomètre cause une altération des concentrations sériques d'INF-γ et de Np chez les chiennes comparativement aux niveaux physiologiques avant la chirurgie et durant la période post-opératoire.(Traduit par Docteur Serge Messier).


Assuntos
Doenças do Cão/cirurgia , Histerectomia/veterinária , Interferon gama/metabolismo , Neopterina/metabolismo , Ovariectomia/veterinária , Animais , Biomarcadores , Cães , Feminino , Regulação da Expressão Gênica , Interferon gama/genética , Neopterina/genética
5.
Stroke ; 48(12): 3223-3231, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-29114094

RESUMO

BACKGROUND AND PURPOSE: Established risk factors do not fully identify patients at risk for recurrent stroke. The SPARCL trial (Stroke Prevention by Aggressive Reduction in Cholesterol Levels) evaluated the effect of atorvastatin on stroke risk in patients with a recent stroke or transient ischemic attack and no known coronary heart disease. This analysis explored the relationships between 13 plasma biomarkers assessed at trial enrollment and the occurrence of outcome strokes. METHODS: We conducted a case-cohort study of 2176 participants; 562 had outcome strokes and 1614 were selected randomly from those without outcome strokes. Time to stroke was evaluated by Cox proportional hazards models. RESULTS: There was no association between time to stroke and lipoprotein-associated phospholipase A2, monocyte chemoattractant protein-1, resistin, matrix metalloproteinase-9, N-terminal fragment of pro-B-type natriuretic peptide, soluble vascular cell adhesion molecule-1, soluble intercellular adhesion molecule-1, or soluble CD40 ligand. In adjusted analyses, osteopontin (hazard ratio per SD change, 1.362; P<0.0001), neopterin (hazard ratio, 1.137; P=0.0107), myeloperoxidase (hazard ratio, 1.177; P=0.0022), and adiponectin (hazard ratio, 1.207; P=0.0013) were independently associated with outcome strokes. After adjustment for the Stroke Prognostic Instrument-II and treatment, osteopontin, neopterin, and myeloperoxidase remained independently associated with outcome strokes. The addition of these 3 biomarkers to Stroke Prognostic Instrument-II increased the area under the receiver operating characteristic curve by 0.023 (P=0.015) and yielded a continuous net reclassification improvement (29.1%; P<0.0001) and an integrated discrimination improvement (42.3%; P<0.0001). CONCLUSIONS: Osteopontin, neopterin, and myeloperoxidase were independently associated with the risk of recurrent stroke and improved risk classification when added to a clinical risk algorithm. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique Identifier: NCT00147602.


Assuntos
Ataque Isquêmico Transitório/epidemiologia , Ataque Isquêmico Transitório/genética , Neopterina/genética , Osteopontina/genética , Peroxidase/genética , Acidente Vascular Cerebral/epidemiologia , Acidente Vascular Cerebral/genética , Idoso , Anticolesterolemiantes/uso terapêutico , Biomarcadores/sangue , Estudos de Coortes , Feminino , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Masculino , Pessoa de Meia-Idade , Neopterina/sangue , Osteopontina/sangue , Peroxidase/sangue , Prognóstico , Curva ROC , Recidiva , Fatores de Risco , Acidente Vascular Cerebral/prevenção & controle
6.
J Neuroimmunol ; 307: 37-41, 2017 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-28495136

RESUMO

BACKGROUND: We examined the heritability of neopterin, a biomarker for cell-mediated immunity and oxidative stress, and potentially for psychiatric disorders, in the Old Order Amish. METHODS: Plasma neopterin levels were determined in 2015 Old Order Amish adults. Quantitative genetic procedures were used to estimate heritability of neopterin. RESULTS: Heritability of log-neopterin was estimated at 0.07 after adjusting for age, gender, and household (p=0.03). The shared household effect was 0.06 (p<0.02). CONCLUSIONS: We found a low heritability of neopterin and small household effect, suggesting that non-household environmental factors are more important determinants of variance of neopterin levels in the Amish.


Assuntos
Envelhecimento/sangue , Amish/estatística & dados numéricos , Neopterina/sangue , Adulto , Envelhecimento/imunologia , Meio Ambiente , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neopterina/genética , Estudos Retrospectivos
7.
J Neurovirol ; 23(2): 250-259, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-27882497

RESUMO

HIV in the central nervous system (CNS) mainly infects microglial cells which are known to express toll-like receptors (TLRs). This paper aimed to study the role of soluble TLR2 (sTLR2), sTLR4, and other inflammatory markers in cerebrospinal fluid (CSF) in HIV/Simian immunodeficiency virus (SIV)-related neurological sequelae. We determined sTLR2 and sTLR4 levels in CSF and serum/plasma of SIV-infected rhesus macaques with and without neurological sequelae, as well as in HIV-infected patients with and without cognitive impairments and Alzheimer's disease (AD) patients and matched controls. CSF cytokines and chemokines levels were analyzed in macaques as markers of neuroinflammation, while neopterin and S100B CSF concentrations were measured in HIV-infected patients as microglial and astrocyte marker, respectively. We found detectable levels of sTLR2 and sTLR4 in CSF of macaques and humans. Furthermore, CSF sTLR2 and sTLR4 concentrations were higher in SIV-infected macaques with neurological sequelae compared to those without neurological complications (p = 0.0003 and p = 0.0006, respectively). CSF IL-8 and monocyte chemoattractant protein-1 (MCP-1) levels were elevated in macaques with neurological sequelae, and a positive correlation was found between CSF levels of sTLR2/4 and IL-8 and MCP-1. Also in humans, elevated CSF sTLR4 levels were found in HIV-infected patients with cognitive impairments compared to HIV-infected patients with normal cognition (p = 0.019). Unlike CSF S100B levels, neopterin correlated positively with sTLR2 and sTLR4. No difference was found in plasma and CSF sTLR2 and sTLR4 levels between AD patients and control subjects (p = 0.26). In conclusion, CSF sTLR2 and sTLR4 may play a role in HIV/SIV-related neuroinflammation and subsequent neuropathology.


Assuntos
Doença de Alzheimer/líquido cefalorraquidiano , Disfunção Cognitiva/líquido cefalorraquidiano , Infecções por HIV/líquido cefalorraquidiano , Síndrome de Imunodeficiência Adquirida dos Símios/líquido cefalorraquidiano , Receptor 2 Toll-Like/imunologia , Receptor 4 Toll-Like/imunologia , Adulto , Doença de Alzheimer/sangue , Doença de Alzheimer/complicações , Doença de Alzheimer/virologia , Animais , Astrócitos/imunologia , Astrócitos/patologia , Astrócitos/virologia , Biomarcadores/sangue , Biomarcadores/líquido cefalorraquidiano , Estudos de Casos e Controles , Quimiocina CCL2/líquido cefalorraquidiano , Quimiocina CCL2/genética , Quimiocina CCL2/imunologia , Disfunção Cognitiva/sangue , Disfunção Cognitiva/complicações , Disfunção Cognitiva/virologia , Feminino , Expressão Gênica , HIV/imunologia , HIV/patogenicidade , Infecções por HIV/sangue , Infecções por HIV/complicações , Infecções por HIV/virologia , Humanos , Interleucina-8/líquido cefalorraquidiano , Interleucina-8/genética , Interleucina-8/imunologia , Macaca mulatta , Masculino , Microglia/imunologia , Microglia/patologia , Microglia/virologia , Pessoa de Meia-Idade , Neopterina/líquido cefalorraquidiano , Neopterina/genética , Neopterina/imunologia , Subunidade beta da Proteína Ligante de Cálcio S100/líquido cefalorraquidiano , Subunidade beta da Proteína Ligante de Cálcio S100/genética , Subunidade beta da Proteína Ligante de Cálcio S100/imunologia , Síndrome de Imunodeficiência Adquirida dos Símios/sangue , Síndrome de Imunodeficiência Adquirida dos Símios/virologia , Vírus da Imunodeficiência Símia/imunologia , Vírus da Imunodeficiência Símia/patogenicidade , Solubilidade , Receptor 2 Toll-Like/genética , Receptor 4 Toll-Like/genética
8.
Am J Med Genet A ; 167A(10): 2430-4, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26059403

RESUMO

We report on a boy who presented with hypophosphatemic rickets with elevated serum fibroblast growth factor 23 (FGF23) and polyostotic osteolytic lesions at age 2 years. Tumor-induced hypophosphatemic rickets was suspected; however, bone biopsy for osteolytic changes revealed no tumorous change, except for irregularly dilated vessels associated with osteoclasts and fibrous proliferation. Venous sampling failed to point to FGF23-producing foci. After alfacalcidol and phosphate supplementation, the rachitic skeletal changes improved, but FGF23 increased and new osteolytic lesions developed. Serum levels of neopterin and a few cytokines, including plasma transforming growth factor-ß and soluble tumor necrosis factor receptor type II, were elevated. At age 4 years, high doses of phosphate resulted in increased serum phosphate levels, decreased neopterin and cytokines, decreased FGF23, and stabilization of osteolysis. We excluded germline mutations in PHEX, FGF23, DMP1, and ENPP1 (genes for hereditary hypophosphatemic rickets) and somatic mutations in the GNAS and HRAS/KRAS (the disease-causing genes for McCune-Albright syndrome and linear nevus sebaceous syndrome, respectively). We could not perform octreotide scintigraphy or fluorodeoxyglucose-positron emission tomography, and thus could not completely exclude occult FGF23-producing tumors. However, considering the course of the disease, it is intriguing to assume that dysregulation of osteoclast-macrophage lineage may have induced increased neopterin levels, increased cytokine levels, osteolytic process, and possibly FGF23 overproduction.


Assuntos
Fatores de Crescimento de Fibroblastos/genética , Displasia Fibrosa Poliostótica/genética , Osteólise/genética , Raquitismo Hipofosfatêmico/genética , Proliferação de Células , Pré-Escolar , Citocinas/sangue , Citocinas/genética , Fator de Crescimento de Fibroblastos 23 , Fatores de Crescimento de Fibroblastos/sangue , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Fibroblastos/patologia , Displasia Fibrosa Poliostótica/sangue , Displasia Fibrosa Poliostótica/tratamento farmacológico , Displasia Fibrosa Poliostótica/patologia , Regulação da Expressão Gênica , Humanos , Hidroxicolecalciferóis/uso terapêutico , Masculino , Neopterina/sangue , Neopterina/genética , Osteoclastos/efeitos dos fármacos , Osteoclastos/metabolismo , Osteoclastos/patologia , Osteólise/sangue , Osteólise/tratamento farmacológico , Osteólise/patologia , Fosfatos/uso terapêutico , Receptores Tipo II do Fator de Necrose Tumoral/sangue , Receptores Tipo II do Fator de Necrose Tumoral/genética , Raquitismo Hipofosfatêmico/sangue , Raquitismo Hipofosfatêmico/tratamento farmacológico , Raquitismo Hipofosfatêmico/patologia , Fator de Crescimento Transformador beta/sangue , Fator de Crescimento Transformador beta/genética
9.
ACS Chem Biol ; 7(1): 197-209, 2012 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-21999246

RESUMO

The biosynthesis of GTP derived metabolites such as tetrahydrofolate (THF), biopterin (BH(4)), and the modified tRNA nucleosides queuosine (Q) and archaeosine (G(+)) relies on several enzymes of the Tunnel-fold superfamily. A subset of these proteins includes the 6-pyruvoyltetrahydropterin (PTPS-II), PTPS-III, and PTPS-I homologues, all members of the COG0720 family that have been previously shown to transform 7,8-dihydroneopterin triphosphate (H(2)NTP) into different products. PTPS-II catalyzes the formation of 6-pyruvoyltetrahydropterin in the BH(4) pathway, PTPS-III catalyzes the formation of 6-hydroxylmethyl-7,8-dihydropterin in the THF pathway, and PTPS-I catalyzes the formation of 6-carboxy-5,6,7,8-tetrahydropterin in the Q pathway. Genes of these three enzyme families are often misannotated as they are difficult to differentiate by sequence similarity alone. Using a combination of physical clustering, signature motif, phylogenetic codistribution analyses, in vivo complementation studies, and in vitro enzymatic assays, a complete reannotation of the COG0720 family was performed in prokaryotes. Notably, this work identified and experimentally validated dual function PTPS-I/III enzymes involved in both THF and Q biosynthesis. Both in vivo and in vitro analyses showed that the PTPS-I family could tolerate a translation of the active site cysteine and was inherently promiscuous, catalyzing different reactions on the same substrate or the same reaction on different substrates. Finally, the analysis and experimental validation of several archaeal COG0720 members confirmed the role of PTPS-I in archaeosine biosynthesis and resulted in the identification of PTPS-III enzymes with variant signature sequences in Sulfolobus species. This study reveals an expanded versatility of the COG0720 family members and illustrates that for certain protein families extensive comparative genomic analysis beyond homology is required to correctly predict function.


Assuntos
Proteínas Arqueais/metabolismo , Biopterinas/metabolismo , Guanosina Trifosfato/metabolismo , Neopterina/análogos & derivados , Fósforo-Oxigênio Liases/metabolismo , Sulfolobus/enzimologia , Motivos de Aminoácidos , Proteínas Arqueais/genética , Biopterinas/genética , Teste de Complementação Genética , Guanosina/análogos & derivados , Guanosina/metabolismo , Cinética , Modelos Moleculares , Dados de Sequência Molecular , Neopterina/genética , Neopterina/metabolismo , Nucleosídeo Q/metabolismo , Fósforo-Oxigênio Liases/genética , Filogenia , Estrutura Terciária de Proteína/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Homologia de Sequência de Aminoácidos , Especificidade por Substrato , Sulfolobus/genética , Tetra-Hidrofolatos/metabolismo
10.
J Bacteriol ; 192(2): 475-82, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19897652

RESUMO

Tetrahydromonapterin is a major pterin in Escherichia coli and is hypothesized to be the cofactor for phenylalanine hydroxylase (PhhA) in Pseudomonas aeruginosa, but neither its biosynthetic origin nor its cofactor role has been clearly demonstrated. A comparative genomics analysis implicated the enigmatic folX and folM genes in tetrahydromonapterin synthesis via their phyletic distribution and chromosomal clustering patterns. folX encodes dihydroneopterin triphosphate epimerase, which interconverts dihydroneopterin triphosphate and dihydromonapterin triphosphate. folM encodes an unusual short-chain dehydrogenase/reductase known to have dihydrofolate and dihydrobiopterin reductase activity. The roles of FolX and FolM were tested experimentally first in E. coli, which lacks PhhA and in which the expression of P. aeruginosa PhhA plus the recycling enzyme pterin 4a-carbinolamine dehydratase, PhhB, rescues tyrosine auxotrophy. This rescue was abrogated by deleting folX or folM and restored by expressing the deleted gene from a plasmid. The folX deletion selectively eliminated tetrahydromonapterin production, which far exceeded folate production. Purified FolM showed high, NADPH-dependent dihydromonapterin reductase activity. These results were substantiated in P. aeruginosa by deleting tyrA (making PhhA the sole source of tyrosine) and folX. The DeltatyrA strain was, as expected, prototrophic for tyrosine, whereas the DeltatyrA DeltafolX strain was auxotrophic. As in E. coli, the folX deletant lacked tetrahydromonapterin. Collectively, these data establish that tetrahydromonapterin formation requires both FolX and FolM, that tetrahydromonapterin is the physiological cofactor for PhhA, and that tetrahydromonapterin can outrank folate as an end product of pterin biosynthesis.


Assuntos
Proteínas de Bactérias/fisiologia , Proteínas de Escherichia coli/fisiologia , Escherichia coli/metabolismo , Pseudomonas aeruginosa/metabolismo , Pterinas/metabolismo , Racemases e Epimerases/fisiologia , Tetra-Hidrofolato Desidrogenase/fisiologia , Proteínas de Bactérias/genética , Biologia Computacional , Escherichia coli/genética , Proteínas de Escherichia coli/genética , Ácido Fólico/metabolismo , Regulação Bacteriana da Expressão Gênica/genética , Regulação Bacteriana da Expressão Gênica/fisiologia , Teste de Complementação Genética , Modelos Genéticos , Mutação , Neopterina/genética , Neopterina/metabolismo , Pseudomonas aeruginosa/genética , Racemases e Epimerases/genética , Tetra-Hidrofolato Desidrogenase/genética
11.
J Neurol Neurosurg Psychiatry ; 79(1): 57-62, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17911184

RESUMO

BACKGROUND: Development of neutralising antibodies (NAbs) against recombinant interferon-beta (IFNbeta) is a significant clinical problem in the treatment of multiple sclerosis (MS). Several methods are available to assess NAbs, but there is a lack of consensus on how the different NAb titre levels interfere with the efficacy of the drug, especially in the individual patient. METHODS: NAb titres were measured with an in vitro MxA induction assay and the in vivo IFNbeta response was assessed by measuring MxA mRNA expression using real-time PCR. RESULTS: We identified titre levels of NAbs at which the IFNbeta biological activity was reduced or abrogated. Patients with NAb titres of up to 150 TRU/ml (ten times reduction units per ml) still had retained IFNbeta bioactivity, whereas greatly reduced levels of IFNbeta bioactivity were found in patients with NAbs of 150-600 TRU/ml. Titres above 600 TRU/ml were associated with loss of IFNbeta bioactivity. Similar results were obtained when TRAIL mRNA was used as a marker of the in vivo response to IFNbeta. CONCLUSION: There is a stepwise loss of IFNbeta bioactivity with increasing NAb titres and it is possible to identify functionally critical NAb titre levels that are useful to support treatment decisions at the individual patient level.


Assuntos
Anticorpos/imunologia , Antivirais/uso terapêutico , Interferon Tipo I/imunologia , Interferon Tipo I/uso terapêutico , Esclerose Múltipla Recidivante-Remitente/tratamento farmacológico , Esclerose Múltipla Recidivante-Remitente/imunologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Antivirais/farmacologia , Encéfalo/patologia , Avaliação da Deficiência , Feminino , Proteínas de Ligação ao GTP/efeitos dos fármacos , Proteínas de Ligação ao GTP/genética , Humanos , Interferon Tipo I/farmacologia , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Esclerose Múltipla Recidivante-Remitente/diagnóstico , Proteínas de Resistência a Myxovirus , Neopterina/genética , Neopterina/farmacologia , RNA Mensageiro/efeitos dos fármacos , RNA Mensageiro/genética , Proteínas Recombinantes , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Titulometria
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...