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1.
Epidemiol Infect ; 148: e17, 2020 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-32014073

RESUMO

In Hungary, between February 2017 and July 2019, 70 confirmed measles cases were reported, raising questions about the adequacy of population-level immunity. Although the assumed vaccination coverage is ≥99%, in a recent study, we detected potential gaps in the anti-measles humoral immunity. In Hungary, according to a decree by the Ministry of Public Welfare, beginning from 2021, the healthcare provider should conduct a serosurvey of anti-measles protection levels of healthcare professionals. To facilitate the compliance with this requirement, we developed a quick 'three-in-one' or 'triple' MMR (measles, mumps and rubella) indirect ELISA (IgG); an assay format that is currently not available commercially. High throughput applicability of the 'three-in-one' ELISA was verified using 1736 sera from routine laboratory residual samples, using an automated platform (Siemens BEP 2000 Advance). Assay verification was performed by comparing the full antigen repertoire-based 'target' assay with in-house 'control' assays using recombinant viral antigen coatings, and by validated commercially available kits. Indirect immunofluorescence was used as an independent reference method. Data were analysed using OriginLab, IBM SPSS, RStudio and MedCalc. In case of measles, we combined our current results with previously published data (Ntotal measles = 3523). Evaluation of anti-mumps and anti-rubella humoral antibody levels was based on the measurement of 1736 samples. The lowest anti-measles seropositivity (79.3%) was detected in sera of individuals vaccinated between 1978 and 1987. Considering the antigen-specific seropositivity ratios of all samples measured, anti-measles, -mumps and -rubella IgG antibody titres were adequate in 89.84%, 91.82% and 92.28%, respectively. Based on the virus-specific herd immunity threshold (HIT) values (HITMeasles = 92-95%, HITMumps = 75-86%, HITRubella = 83-86), it can be stated that regarding anti-measles immunity, certain age clusters of the population may have inadequate levels of humoral immunity. Despite the potential gaps in herd immunity, the use of MMR vaccine remains an effective and low-cost approach for the prevention of measles, mumps and rubella infections.


Assuntos
Anticorpos Antivirais/sangue , Análise Custo-Benefício , Ensaio de Imunoadsorção Enzimática/economia , Ensaio de Imunoadsorção Enzimática/métodos , Imunidade Humoral , Vacina contra Sarampo-Caxumba-Rubéola/imunologia , Adolescente , Automação Laboratorial/economia , Automação Laboratorial/métodos , Criança , Pré-Escolar , Feminino , Humanos , Hungria , Imunoglobulina G/sangue , Lactente , Recém-Nascido , Masculino , Vacina contra Sarampo-Caxumba-Rubéola/administração & dosagem , Resultado do Tratamento , Adulto Jovem
2.
Clin Exp Immunol ; 193(1): 55-63, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29573404

RESUMO

Our previous studies showed that anti-citrate synthase (anti-CS) immunoglobulin (Ig)M natural autoantibodies are present in healthy individuals without previous antigen stimulation, but no studies have investigated their presence in the pericardial fluid (PF). Therefore, we detected the natural anti-CS IgG/M autoantibody levels in plasma and PF of cardiac surgery patients and investigated their relationship with cardiovascular disease-associated bacterial pathogens. PF and blood samples of 22 coronary artery bypass graft (CABG) and 10 aortic valve replacement (AVR) patients were tested for total Ig levels, natural autoantibodies and infection-related antibodies using enzyme-linked immunosorbent assay (ELISA) and Luminex methods. The B cell subsets were measured by flow cytometry. The total Ig subclass levels were four to eight times lower in PF than in plasma, but the natural anti-CS IgM autoantibodies showed a relative increase in PF. The frequency of CD19+ B lymphocytes was significantly lower in PF than in blood (P = 0·01), with a significant relative increase of B1 cells (P = 0·005). Mycoplasma pneumoniae antibody-positive patients had significantly higher anti-CS IgM levels. In CABG patients we found a correlation between anti-CS IgG levels and M. pneumoniae, Chlamydia pneumoniae and Borrelia burgdorferi antibody titres. Our results provide the first evidence that natural autoantibodies are present in the PF, and they show a significant correlation with certain anti-bacterial antibody titres in a disease-specific manner.


Assuntos
Anticorpos Antibacterianos/sangue , Autoanticorpos/sangue , Subpopulações de Linfócitos B/citologia , Doenças Cardiovasculares/cirurgia , Citrato (si)-Sintase/imunologia , Líquido Pericárdico/imunologia , Anticorpos Antibacterianos/imunologia , Valva Aórtica/cirurgia , Autoanticorpos/imunologia , Borrelia burgdorferi/imunologia , Doenças Cardiovasculares/imunologia , Chlamydophila pneumoniae/imunologia , Ponte de Artéria Coronária , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Imunoglobulina M/sangue , Imunoglobulina M/imunologia , Masculino , Pessoa de Meia-Idade , Mycoplasma pneumoniae/imunologia
3.
Gene Ther ; 20(2): 143-50, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22402322

RESUMO

Medulloblastoma is a heterogeneous diffuse neoplasm that can be highly disseminated, and is the most common malignant childhood brain tumor. Although multimodal treatments have improved survival rates for patients with medulloblastoma, these tumors are associated with high morbidity and mortality. New treatment strategies are urgently needed to improve cure rates and, importantly, to spare normal brain tissue from neurotoxicity and patients from life-long cognitive and functional deficits associated with current therapies. In numerous preclinical brain tumor models, neural stem cells (NSCs) have shown great promise as delivery vehicles for therapeutic genes. Here, we have used an established, genetically modified human NSC line (HB1.F3.CD) to deliver carboxylesterase (CE) to cerebellar tumor foci and locally activate the prodrug camptothecin-11 (CPT-11) (Irinotecan) to the potent topoisomerase I inhibitor SN-38. HB1.F3.CD NSC tumor tropism, intratumoral distribution and therapeutic efficacy were investigated in clinically relevant experimental models. Magnetic resonance imaging was used for in vivo tracking of iron nanoparticle-labeled NSCs, and to assess the therapeutic efficacy of CE-expressing HB1.F3.CD cells. As compared with controls, a significant decrease in tumor growth rate was seen in mice that received both NSCs and CPT-11 as their treatment regimen. Thus, this study provides proof-of-concept for NSC-mediated CE/CPT-11 treatment of medulloblastoma, and serves as a foundation for further studies toward potential clinical application.


Assuntos
Carboxilesterase/genética , Neoplasias Cerebelares/terapia , Terapia Genética , Meduloblastoma/terapia , Pró-Fármacos/uso terapêutico , Animais , Antineoplásicos Fitogênicos/uso terapêutico , Camptotecina/análogos & derivados , Camptotecina/uso terapêutico , Linhagem Celular Tumoral , Neoplasias Cerebelares/enzimologia , Neoplasias Cerebelares/genética , Técnicas de Transferência de Genes , Humanos , Irinotecano , Meduloblastoma/enzimologia , Meduloblastoma/genética , Camundongos , Camundongos Nus , Camundongos Transgênicos , Células-Tronco Neurais/enzimologia , Transplante de Células-Tronco , Resultado do Tratamento
4.
Gene Ther ; 15(10): 739-52, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18369324

RESUMO

The poor prognosis for patients with aggressive or metastatic tumors and the toxic side effects of currently available treatments necessitate the development of more effective tumor-selective therapies. Stem/progenitor cells display inherent tumor-tropic properties that can be exploited for targeted delivery of anticancer genes to invasive and metastatic tumors. Therapeutic genes that have been inserted into stem cells and delivered to tumors with high selectivity include prodrug-activating enzymes (cytosine deaminase, carboxylesterase, thymidine kinase), interleukins (IL-2, IL-4, IL-12, IL-23), interferon-beta, apoptosis-promoting genes (tumor necrosis factor-related apoptosis-inducing ligand) and metalloproteinases (PEX). We and others have demonstrated that neural and mesenchymal stem cells can deliver therapeutic genes to elicit a significant antitumor response in animal models of intracranial glioma, medulloblastoma, melanoma brain metastasis, disseminated neuroblastoma and breast cancer lung metastasis. Most studies reported reduction in tumor volume (up to 90%) and increased survival of tumor-bearing animals. Complete cures have also been achieved (90% disease-free survival for >1 year of mice bearing disseminated neuroblastoma tumors). As we learn more about the biology of stem cells and the molecular mechanisms that mediate their tumor-tropism and we identify efficacious gene products for specific tumor types, the clinical utility of cell-based delivery strategies becomes increasingly evident.


Assuntos
Terapia Genética/métodos , Transplante de Células-Tronco Mesenquimais/métodos , Neoplasias/terapia , Animais , Linhagem Celular , Técnicas de Transferência de Genes , Engenharia Genética , Humanos , Células-Tronco Mesenquimais/fisiologia , Células-Tronco/fisiologia
5.
J Comp Neurol ; 433(1): 4-22, 2001 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-11283945

RESUMO

Active caspase-3 immunoreactivity was detected in the rat forebrain proliferative regions at birth and remained high in these areas for about 2 weeks, during which period labeled cells were present centroperipherally across the olfactory bulb. By the end of the third postnatal week, only a small number of immunolabeled cells remained in these forebrain structures. Active caspase-3 immunolabeling was localized mostly to cell nuclei and co-localized partially with TuJ1 and NeuN immunoreactivity, but not with glial fibrially acidic protein, OX-42, gamma-aminobutyric acid, or terminal deoxynucleotidyl transferase-mediated nick end labeling (TUNEL)-positive labeling. Active caspase-3 and 5-bromo-2'-deoxyuridine (BrdU) double-labeled nuclei were seen in the proliferative regions after 2 hours and in the periglomerular region of the bulb after 7 days following BrdU injections. Examination of the cells with electron microscopy confirmed that the active caspase-3-containing nuclei in the proliferative regions often had infoldings and appeared to be undergoing division. Some of the cells with active caspase-3-labeled nuclei in the bulb had synapses on their somata or dendrites. Labeled dendritic spines and a few axon terminals were also observed in the olfactory bulb. Taken together, it appears that a wave of active caspase-3-positive cells are dividing in the proliferative zones and then migrating to the bulb as they differentiate into neurons. Therefore, active caspase-3 may play a role in cellular processes such as neuronal differentiation, migration, and plasticity, in addition to its role in cell death.


Assuntos
Caspases/metabolismo , Mitose/fisiologia , Neurônios/enzimologia , Bulbo Olfatório/citologia , Ratos Wistar/metabolismo , Animais , Anticorpos , Antimetabólitos , Bromodesoxiuridina , Caspase 3 , Caspases/análise , Caspases/imunologia , Divisão Celular/fisiologia , Imunofenotipagem , Marcação In Situ das Extremidades Cortadas , Masculino , Microscopia Eletrônica , Neurônios/ultraestrutura , Bulbo Olfatório/crescimento & desenvolvimento , Ratos , Células-Tronco/enzimologia , Células-Tronco/ultraestrutura
6.
Neuroscience ; 99(1): 107-17, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10924956

RESUMO

Aspirin (acetylsalicylic acid), and its main metabolite sodium salicylate, have been shown to protect neurons from excitotoxic cell death in vitro. The objective of our study was to investigate the possible neuroprotective effects of sodium salicylate in vivo in rats with kainic acid-induced seizures, a model for temporal lobe epilepsy in human patients. Male Sprague-Dawley rats received intraperitoneal injections of kainic acid either alone, or with sodium salicylate given before and for 40h after kainic acid injections. The control group received either phosphate-buffered saline or sodium salicylate without co-administration of kainic acid. Animals developed status epilepticus, which was aborted 1.5-2h later with diazepam. On day 3 following kainic acid-induced seizures, animals received bromodeoxyuridine to measure cellular proliferation, and were killed under anesthesia 24h later. Brains were removed, sectioned, and analysed for gross histological changes, evidence of hemorrhage, DNA fragmentation, cellular proliferation, and microglial immunohistochemistry. We report that sodium salicylate did not protect neurons from seizure-induced cell death, and to the contrary, it caused focal hemorrhage and cell death in the hippocampal formation and the entorhinal/piriform cortex of rats with kainic acid-induced seizures. Hemorrhage was never observed in animals that received vehicle, kainic acid or sodium salicylate only, which indicated that sodium salicylate exerted its effect only in animals with seizures, and was confined to select regions of the brain that undergo seizure activity. Large numbers of cells displaying DNA fragmentation were detected in the hippocampal formation, entorhinal/piriform cortex and the dorsomedial thalamic nucleus of rats that received kainic acid or kainic acid in combination with sodium salicylate. Bromodeoxyuridine immunohistochemistry revealed large numbers of proliferating cells in and around the areas with most severe neural injury induced by kainic acid or kainic acid co-administered with sodium salicylate. These same brain regions displayed intense staining with a microglia-specific marker, an indication of microglial activation in response to brain damage. In all cases, the degree of cell death, cell proliferation and microglia staining was more severe in animals that received the combination of kainic acid and sodium salicylate when compared to animals that received kainic acid alone. We hypothesize that our findings are attributable to sodium salicylate-induced blockade of cellular mechanisms that protect cells from calcium-mediated injury. These initial observations may have important clinical implications for patients with epilepsy who take aspirin while affected by these conditions, and should promote further investigation of this relationship.


Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Hemorragia Cerebral/induzido quimicamente , Hipocampo/efeitos dos fármacos , Microglia/efeitos dos fármacos , Convulsões , Salicilato de Sódio/farmacologia , Animais , Aspirina/metabolismo , Morte Celular/efeitos dos fármacos , Morte Celular/fisiologia , Contraindicações , Agonistas de Aminoácidos Excitatórios , Hipocampo/citologia , Hipocampo/lesões , Ácido Caínico , Masculino , Microglia/fisiologia , Neurônios/efeitos dos fármacos , Neurônios/fisiologia , Fármacos Neuroprotetores , Ratos , Ratos Sprague-Dawley , Convulsões/induzido quimicamente
7.
Biochemistry ; 35(16): 5183-90, 1996 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-8611502

RESUMO

The formation of isoaspartyl sites during aging of rat tubulin in vitro and in vivo has been studied. When incubated in vitro at pH 7.4, 37 degrees C, purified rat brain tubulin accumulated isoaspartyl sites at a rate > or = 2.4 isoaspartyl sites per 100 tubulin subunits (50 kDa) per day for 30 days. Isoaspartate levels were estimated by the transfer of radiolabeled methyl groups from S-adenosyl-L-[methyl-3H]-methionine in a reaction catalyzed by protein-L-isoaspartyl methyltransferase. isoaspartate formation occurred in parallel with, but was not dependent upon, extensive cross-linking of tubulin via formation of intermolecular disulfide bonds. When rat PC12 cells were incubated for 24 or 72 h in the presence of adenosine dialdehyde, a potent methyltransferase inhibitor, a substantial and consistent increase in the isoaspartate content of tubulin was observed. This suggests that tubulin constantly undergoes isoaspartate formation in vivo, but that the levels are normally kept low by methylation-dependent repair. These findings support the hypothesis that protein-isoaspartyl methyltransferase plays a key role in countering spontaneous damage reactions to proteins associated with cell aging. These results also suggest that tubulin is an important target for protein-isoaspartyl methyltransferase in vivo.


Assuntos
Ácido Aspártico/biossíntese , Tubulina (Proteína)/metabolismo , Animais , Senescência Celular , Isomerismo , Células PC12 , Conformação Proteica , Proteína D-Aspartato-L-Isoaspartato Metiltransferase , Proteínas Metiltransferases/metabolismo , Ratos , Ratos Sprague-Dawley , S-Adenosilmetionina/metabolismo , Especificidade por Substrato
8.
Neuroreport ; 7(1): 197-200, 1995 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-8742450

RESUMO

The effect of olfactory deprivation on cellular expression of the Bcl-2 gene in the olfactory bulb of young rats was investigated. Restriction of olfactory stimuli caused an overall increase in Bcl-2 mRNA expression, with increases seen in the lateral aspects of glomerular, external plexiform, mitral and granule cell layers, as well as the medial aspects of external plexiform layer. No differences were found in the unoperated control group. In addition, we found an inverse relationship between the incidence of apoptosis induced by olfactory deprivation and the magnitude of increase in Bcl-2 mRNA expression in the glomerular layer. These data raise the possibility that Bcl-2 may be involved in olfactory experience-related neural plasticity by regulating cell survival.


Assuntos
Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Proteínas do Tecido Nervoso/genética , Bulbo Olfatório/metabolismo , Proteínas Proto-Oncogênicas/genética , Olfato/fisiologia , Animais , Apoptose/fisiologia , Hibridização In Situ , Masculino , Proteínas Proto-Oncogênicas c-bcl-2 , Ratos , Ratos Wistar
9.
Brain Res ; 674(2): 245-51, 1995 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-7796103

RESUMO

Early sensory stimulation plays a key role in shaping the structure and function of the developing olfactory system. Here, we provide the first direct evidence for apoptotic cell death in the olfactory bulbs of rat pups during normal development and we also demonstrate that olfactory deprivation by unilateral naris occlusion causes a dramatic increase in apoptotic cell death in the glomerular and granule cell layers of the deprived bulb. The accessory olfactory bulbs displayed a remarkably high basal level of apoptosis but the occluded accessory bulb did not differ in that regard from the control accessory bulb. These results suggest that apoptosis may be an important mechanism by which the olfactory system can adjust its cell numbers in response in sensory stimuli experienced in early life, thereby underlying one form of plasticity in the developing olfactory system.


Assuntos
Apoptose/fisiologia , Bulbo Olfatório/crescimento & desenvolvimento , Bulbo Olfatório/fisiologia , Privação Sensorial/fisiologia , Olfato/fisiologia , Animais , Histocitoquímica , Masculino , Obstrução Nasal/fisiopatologia , Plasticidade Neuronal/fisiologia , Bulbo Olfatório/citologia , Ratos , Ratos Wistar
10.
J Biol Chem ; 268(14): 10501-9, 1993 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-7683681

RESUMO

Several proteins that interact with RNA, e.g. the heterogenous ribonucleoprotein particle A and B proteins, fibrillarin and nucleolin, contain the modified amino acid NG,NG-dimethylarginine. Here, we report that two synthetic peptides, Ac-GGRGGFGGRGGFGGRGGFG-NH2 (R3) and GGFGGRGGFG-NH2 (R1), which are based on methylated sequences in fibrillarin and nucleolin, inhibit the methylation of a large majority of the methyl-accepting proteins observed in extracts of adenosine dialdehyde-treated PC12 cells. Concomitantly, the peptides themselves become methylated, suggesting that they compete for the same enzyme that carries out the bulk of N-methylation in PC12 cells. R3 potently inhibits formation of NG,NG-dimethylarginine in PC12 substrates, with a lesser effect on NG-monomethylarginine and NG,N'G-dimethylarginine. Bovine brain contains an activity that methylates PC12 methyl acceptors. After partial purification, the bovine methyltransferase efficiently modifies R3 and R1, yielding half-maximal rates of methylation at approximately 0.2 and approximately 2 microM peptide, respectively. A search of the GenPept database for the FGGRGGF motif revealed 13 candidate methyl acceptors containing arginine and at most two similar substitutions or one mismatch. Of these, 10 are known or presumed to interact with RNA. These findings are consistent with the hypothesis that a majority of proteins containing NG,NG-dimethylarginine interact with RNA.


Assuntos
Proteínas Cromossômicas não Histona/metabolismo , Metiltransferases/metabolismo , Proteínas Nucleares/metabolismo , Peptídeos/metabolismo , Fosfoproteínas/metabolismo , Proteínas de Ligação a RNA , RNA/metabolismo , Ribonucleoproteínas/metabolismo , Sequência de Aminoácidos , Animais , Arginina/análogos & derivados , Arginina/metabolismo , Encéfalo/enzimologia , Bovinos , Glicina , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Cinética , Metilação , Dados de Sequência Molecular , Células PC12 , Peptídeos/síntese química , Peptídeos/farmacologia , Proteína-Arginina N-Metiltransferases , Homologia de Sequência de Aminoácidos , Especificidade por Substrato
11.
J Biol Chem ; 268(9): 6174-81, 1993 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-8454593

RESUMO

Protein isoaspartyl methyltransferase is implicated in the repair of age-damaged proteins containing atypical, isoaspartyl linkages. To test the prediction that isoaspartyl proteins would accumulate during methyltransferase inhibition, rat PC12 cells were treated with the indirect methylation inhibitor, adenosine dialdehyde. We observed a marked, dose- and time-dependent, reversible accumulation of substrates for the enzyme that closely paralleled the elevation of its competitive inhibitor, S-adenosylhomocysteine. The accumulation of substrates also paralleled a cytostatic action of adenosine dialdehyde; however, 30 microM 3-deazaadenosine, another indirect methylation inhibitor, also caused an accumulation of substrates without affecting cell division, and other cytostatic agents did not affect substrate levels. Acidic gel electrophoresis revealed increased methyl-accepting capacity in a broad spectrum of proteins, with predominant increases in discrete bands of M(r) 46,000 and 110,000. A major substrate (M(r) 17,400) in untreated cells did not increase in methyl-accepting capacity during treatment. Methyl groups at the accumulated sites did not survive conventional electrophoresis, indicating the lability characteristic of isoaspartyl methyl esters in damaged proteins. These results are consistent with an involvement of the methyltransferase in the metabolism of damaged proteins, and they provide a basis for the characterization of physiological substrates for the enzyme.


Assuntos
Adenosina/análogos & derivados , Proteínas Metiltransferases/metabolismo , Adenosina/metabolismo , Adenosina/farmacologia , Sequência de Aminoácidos , Animais , Divisão Celular , Cinética , Metilação , Dados de Sequência Molecular , Oxirredução , Células PC12 , Proteína D-Aspartato-L-Isoaspartato Metiltransferase , Proteínas/metabolismo , Especificidade por Substrato
12.
Arch Biochem Biophys ; 293(1): 85-92, 1992 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-1731643

RESUMO

It was demonstrated recently that substrates for protein N-methyltransferases (J. Najbauer and D. W. Aswad, 1990, J. Biol. Chem. 265, 12,717-12,721) and protein carboxyl methyltransferases (J. Najbauer, B. A. Johnson, and D. W. Aswad, 1991, Anal. Biochem. 197, 412-420) accumulate when rat PC12 cells are cultured in the presence of the methylation inhibitor, adenosine dialdehyde. In the present report, we have further characterized this phenomenon in PC12 cells and in two other, widely used cell types. Adenosine dialdehyde was found to increase the methyl-accepting capacity of proteins in human skin fibroblasts and mouse Sp2/0 myeloma cells. However, both the level of methyl incorporation in untreated cells and the amount of stimulation afforded by inhibitor treatment were substantially lower in these cells than in PC12 cells. All three cell lines accumulated methyl acceptor(s) at 17-21 kDa. The PC12 cells and the fibroblasts also exhibited stimulation of three apparently similar proteins in the 33- to 38-kDa region, where several arginine-methylated proteins involved in RNA processing would be expected. The optimal conditions for methylation of PC12 cell extracts with regard to pH, time of methylation, and S-[methyl-3H]adenosyl-L-methionine concentration were characterized. Increased methyl incorporation was detected after adenosine dialdehyde treatments as short as 2 h, and methylation of most substrates continued to increase as the time of treatment was extended to 72 h. The kinetics of accumulation varied from substrate to substrate. Fluorograms of two-dimensional gels of extracts from untreated PC12 cells incubated in the presence of S-[methyl-3H]adenosyl-L-methionine revealed patterns of methyl incorporation similar to those of treated cells, but longer exposure times were necessary (e.g., 35 days vs 7 days). These findings suggest that the inhibitor treatment works mainly by inhibiting the post- or cotranslational methylation of a "normal" array of cellular proteins.


Assuntos
Histona-Lisina N-Metiltransferase/metabolismo , Proteína-Arginina N-Metiltransferases/metabolismo , Proteínas/metabolismo , Adenosina/análogos & derivados , Adenosina/farmacologia , Animais , Eletroforese em Gel Bidimensional , Concentração de Íons de Hidrogênio , Técnicas In Vitro , Metilação , Células PC12 , Processamento de Proteína Pós-Traducional , Ratos
13.
Anal Biochem ; 197(2): 412-20, 1991 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-1785697

RESUMO

A strategy that facilitates the identification of substrates for protein carboxyl methyltransferases that form "stable" methyl esters, i.e., those that remain largely intact during conventional polyacrylamide gel electrophoresis is described. Rat PC12 cells were cultured in the presence of adenosine dialdehyde (a methylation inhibitor) to promote the accumulation of hypomethylated proteins. Nonidet P-40 cell extracts were then incubated in the presence of S-[methyl-3H]adenosyl-L-methionine to label methyl-accepting sites via endogenous methyltransferases. After labeled proteins were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, gel slices were incubated in 4 N methanesulfonic acid or 6 N HCl to hydrolyze methyl esters. The resulting [3H]methanol was detected by trapping in liquid scintillation fluid. Seven carboxyl methylated proteins were observed with masses ranging from 18 to 96 kDa. Detection of five of these proteins required prior treatment of cells with adenosine dialdehyde, while methyl incorporation into one protein at 18 kDa was substantially enhanced by the treatment. The use of acidic conditions for methyl ester hydrolysis has an important advantage over assays that utilize alkaline hydrolysis conditions. In PC12 cells, and possibly other cell types where there are significant levels of arginine methylation, the methanol signal becomes obscured by high levels of volatile methylamines generated under the alkaline conditions. Carrying out diffusion assays under acidic conditions eliminates this interference. Adenosine dialdehyde, by virtue of increasing the methyl-accepting capacity of substrates for protein carboxyl methyltransferases, in combination with a more selective assay for carboxyl methylation, should prove useful in the isolation and characterization of new protein carboxyl methyltransferases and their substrates.


Assuntos
Adenosina/análogos & derivados , Metiltransferases/metabolismo , Proteínas/metabolismo , Adenosina/farmacologia , Animais , Linhagem Celular , Cromatografia Líquida de Alta Pressão , Eletroforese em Gel de Poliacrilamida , Hidrólise , Técnicas In Vitro , Metanol/análise , Metilação , Metiltransferases/antagonistas & inibidores , Proteínas/análise , Ratos , S-Adenosilmetionina/metabolismo
14.
Acta Physiol Hung ; 77(1): 85-92, 1991.
Artigo em Inglês | MEDLINE | ID: mdl-1719745

RESUMO

The effect of immunization with neural and nonneural antigens on hypothalamic and mesencephalic neurotransmission and antibody response have been investigated. Treatment of SJL/N mice with bovine myelin basic protein (BMBP), mouse spinal cord homogenate (MSCH) or bovine serum albumin (BSA) produced no significant changes in the average hypothalamic and mesencephalic noradrenaline (NA) or serotonin (5-HT) content. In Balb/c mice, however, treatment with BMBP caused a significant increase in mesencephalic NA, and treatment with MSCH caused a significant increase in hypothalamic 5-HT 3 weeks after the first antigenic challenge. The SJL/N strain showed a high antibody response to BMBP and BSA, and a moderate one to MSCH, while in Balb/c mice, there was a low response to BMBP, a moderate one to MSCH and a high response to BSA. Significant, positive correlations were found between the level of antigen-specific serum antibodies and the following neurotransmitters: hypothalamic NA in the BMBP and MSCH-treated groups, hypothalamic 5-HT in the MSCH-treated group, mesencephalic NA and 5-HT in the BMBP-treated group, and mesencephalic 5-HT in the MSCH-treated SJL/N animals. No significant correlations between the levels of antibodies and neurotransmitters have been found either in the BSA-immunized SJL/N animals, or in any of the groups of Balb/c mice treated with BMBP, MSCH or BSA.


Assuntos
Encéfalo/metabolismo , Proteína Básica da Mielina/farmacologia , Norepinefrina/metabolismo , Serotonina/metabolismo , Animais , Formação de Anticorpos , Variação Antigênica/imunologia , Encéfalo/imunologia , Ensaio de Imunoadsorção Enzimática , Feminino , Estudos Longitudinais , Camundongos , Camundongos Endogâmicos BALB C , Soroalbumina Bovina/farmacologia , Especificidade da Espécie , Medula Espinal/imunologia
15.
J Biol Chem ; 265(21): 12717-21, 1990 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-2373708

RESUMO

Protein N-methylation is a widespread modification whose functions are poorly understood. To overcome the inherent technical difficulties in identification of N-methylated proteins, we cultured PC12 cells with a methylation inhibitor, in expectation that proteins would accumulate in a hypomethylated state. Cell extracts were then incubated with [methyl-3H]S-adenosyl-L-methionine to label methyl-accepting sites via endogenous methyltransferases. Using two-dimensional gel electrophoresis we detected over 50 methyl acceptors, ranging from 18 to 120 kDa. Most had isoelectric points greater than 7.0. NG,NG-Dimethylarginine and NG-monomethylarginine accounted for about 90% of the methyl-3H-amino acids recovered after acid hydrolysis and thin-layer chromatography. The production of hypomethylated proteins should prove useful, not only in the identification of new methyl acceptors, but also in the isolation and characterization of new methyltransferases.


Assuntos
Adenosina/análogos & derivados , Desoxiadenosinas , Proteínas de Neoplasias/metabolismo , Feocromocitoma/metabolismo , Adenosina/farmacologia , Neoplasias das Glândulas Suprarrenais/metabolismo , Animais , Eletroforese em Gel Bidimensional , Metilação , Peso Molecular , Proteínas do Tecido Nervoso/metabolismo , Ratos , S-Adenosilmetionina/metabolismo , Tionucleosídeos/farmacologia , Tubercidina/farmacologia , Células Tumorais Cultivadas
16.
Acta Med Hung ; 47(3-4): 129-33, 1990.
Artigo em Inglês | MEDLINE | ID: mdl-1966628

RESUMO

The non-specific peroxidase (donor: H2O2-oxidoreductase, EC 1.11.1.7) activity of red blood cells in patients with multiple sclerosis, patients with other neurological diseases, and healthy control individuals was investigated. To this end, a simple method was developed. No significant difference was found in the non-specific peroxidase activity of red blood cells from patients with multiple sclerosis and controls.


Assuntos
Eritrócitos/enzimologia , Esclerose Múltipla/enzimologia , Peroxidase/sangue , Adulto , Feminino , Humanos , Masculino , Esclerose Múltipla/sangue , Doenças do Sistema Nervoso/sangue , Doenças do Sistema Nervoso/enzimologia , Valores de Referência
17.
Acta Neurol Scand ; 79(6): 476-81, 1989 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-2782028

RESUMO

Autoradiography of brain slices from 4 multiple sclerosis (MS) and 9 control patients was performed. After 6 weeks of exposure the exact picture of the white matter appeared on the X-ray films in all cases with MS, but only in one of the controls. The high level of autoradiographic signal from MS white matter suggests that an abnormal accumulation of radioactive trace elements takes place within the brains of MS victims.


Assuntos
Autorradiografia , Encéfalo/patologia , Esclerose Múltipla/patologia , Adolescente , Adulto , Idoso , Animais , Cães , Humanos , Intoxicação por Chumbo/complicações , Masculino , Pessoa de Meia-Idade , Esclerose Múltipla/etiologia
18.
Immunol Lett ; 20(4): 317-22, 1989 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-2541082

RESUMO

The effect of 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) was investigated in single cell cytotoxicity assays, using K-562 target cells. The action of vitamin D3 sulfate (VD3S) in natural cytotoxicity assays as well as its effect on the antigen-specific adherence of hybridoma cells has also been studied. In the single cell cytotoxicity assay 1,25(OH)2D3 dose-dependently and significantly increased the binding of PBMC to target, the number of lysed target cells and NK activity. RU486, a compound known as a potent blocker of progesterone and glucocorticoid receptors, suppressed the effect of 1,25(OH)2D3 in all systems. VD3S dose-dependently decreased the natural cytotoxicity of PBMC and the binding of hybridoma cells to antigen immobilized on plastic surfaces. The results suggest that both 1,25(OH)2D3 and VD3S are potent modulatory agents in cell-cell and cell-antigen interactions.


Assuntos
Calcitriol/farmacologia , Colecalciferol/farmacologia , Citotoxicidade Imunológica/efeitos dos fármacos , Adulto , Linhagem Celular , Células Cultivadas , Testes Imunológicos de Citotoxicidade , Estrenos/metabolismo , Feminino , Fibroblastos/metabolismo , Humanos , Hibridomas/imunologia , Técnicas In Vitro , Células Matadoras Naturais/metabolismo , Linfócitos/metabolismo , Mifepristona , Gravidez
19.
J Neurochem ; 50(5): 1469-77, 1988 May.
Artigo em Inglês | MEDLINE | ID: mdl-2452236

RESUMO

We report the development of a simple and reliable method for the study of demyelination in vitro based on the measurement of 2':3'-cyclic nucleotide 3'-phosphodiesterase in isolated myelin. Using only small quantities of myelin (equivalent to 100 micrograms of myelin protein) the system was tested under conditions that are believed to approximate those found at the site of an inflammatory demyelinating lesion. Treatment with a combination of trypsin, phospholipase A2, and lysophosphatidylcholine was used to evaluate the method. This microsystem has the potential not only for testing the myelinotoxicity of soluble factors but also for investigating the involvement of inflammatory cells in the demyelinating process. Myelin degradation by elicited peritoneal macrophages could be demonstrated at relatively high densities of these cells. Nylon wool purified lymph node T cells from myelin basic protein-primed SJL/J mice, after selective expansion with antigen and interleukin 2, failed to induce any significant myelin breakdown unless a limited number of syngeneic activated macrophages were also present. T cells from mice that had been inoculated with keyhole limpet haemocyanin failed to show any effect. The advantages of this technique over other in vitro systems are that it enables the study of demyelination using syngeneic sources of myelin and defined cell populations.


Assuntos
Doenças Desmielinizantes/metabolismo , Bainha de Mielina/metabolismo , 2',3'-Nucleotídeo Cíclico Fosfodiesterases/metabolismo , Animais , Antígenos/imunologia , Doenças Desmielinizantes/patologia , Feminino , Hemocianinas/imunologia , Técnicas In Vitro , Lisofosfatidilcolinas/farmacologia , Macrófagos/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Proteína Básica da Mielina/metabolismo , Bainha de Mielina/efeitos dos fármacos , Bainha de Mielina/imunologia , Bainha de Mielina/ultraestrutura , Fagocitose , Fosfolipases A/farmacologia , Fosfolipases A2 , Sulfoglicoesfingolipídeos/metabolismo , Linfócitos T/imunologia , Tripsina/farmacologia
20.
Acta Neurol Scand ; 76(3): 172-5, 1987 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-2446461

RESUMO

Red blood cells (RBC) and white blood cells (WBC) of patients with multiple sclerosis (MS) show decreased adherence to myelin basic protein (MBP) immobilized on plastic surfaces compared to the binding of cells from patients with other neurological diseases (OND), or such other autoimmune diseases as psoriasis (PS), and to that of healthy controls (HC). No similar phenomenon occurred to basic and non-basic type proteins other than MBP, for example, to histone (HIS), lysozyme (LYS) and ovalbumin (OVA). Thus, decreased adherence of RBC and WBC in MS patients to MBP appears to be a unique feature of the disease if compared with OND or PS.


Assuntos
Eritrócitos/fisiologia , Leucócitos/fisiologia , Esclerose Múltipla/sangue , Proteína Básica da Mielina , Adesão Celular , Eritrócitos/citologia , Humanos , Leucócitos/citologia , Valores de Referência , Relação Estrutura-Atividade
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