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1.
Genes Cells ; 27(2): 113-123, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34921694

RESUMO

Neural functions are known to decline during normal aging and neurodegenerative diseases. However, the mechanisms of functional impairment owing to the normal aging of the brain are poorly understood. Previously, we reported that caspase-3-like protease, the protease responsible for inducing apoptosis, is activated in a subset of olfactory receptor neurons (ORNs), especially in Drosophila Or42b neurons, during normal aging. Herein, we investigated the molecular mechanism underlying age-related caspase-3-like protease activation and cell death in Or42b neurons. Gene expression profiling of young and aged fly antenna showed that the expression of antimicrobial peptides was significantly upregulated, suggesting an activated innate immune response. Consistent with this observation, inhibition or activation of the innate immune pathway caused delayed or precocious cell death, respectively, in Or42b neurons. Accordingly, autonomous cell activation of the innate immune pathway in Or42b neurons is not likely required for their age-related death, whereas the systemic innate immune response induces caspase-3-like protease activation in Or42b neurons; this indicated that the death of these neurons is regulated non-cell autonomously. We propose a possible link between the innate immune response and the death of olfactory neurons during normal aging.


Assuntos
Proteínas de Drosophila , Neurônios Receptores Olfatórios , Animais , Apoptose , Drosophila/metabolismo , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Imunidade Inata , Neurônios Receptores Olfatórios/metabolismo
2.
Sci Rep ; 10(1): 11798, 2020 07 16.
Artigo em Inglês | MEDLINE | ID: mdl-32678126

RESUMO

Polyunsaturated fatty acids (PUFAs) play crucial roles in adaptation to cold environments in a wide variety of animals and plants. However, the mechanisms by which PUFAs affect thermoregulatory behaviour remain elusive. Thus, we investigated the roles of PUFAs in thermoregulatory behaviour of Drosophila melanogaster. To this end, we generated transgenic flies expressing Caenorhabditis elegans Δ12 fatty acid desaturase (FAT-2), which converts mono-unsaturated fatty acids to PUFAs such as linoleic acid [C18:2 (n-6)] and linolenic acid [C18:3 (n-3)]. Neuron-specific expression of FAT-2 using the GAL4/UAS expression system led to increased contents of C18:2 (n-6)-containing phospholipids in central nerve system (CNS) and caused significant decreases in preferred temperature of third instar larvae. In genetic screening and calcium imaging analyses of thermoreceptor-expressing neurons, we demonstrated that ectopic expression of FAT-2 in TRPA1-expressing neurons led to decreases in preferred temperature by modulating neuronal activity. We conclude that functional expression of FAT-2 in a subset of neurons changes the thermoregulatory behaviour of D. melanogaster, likely by modulating quantities of PUFA-containing phospholipids in neuronal cell membranes.


Assuntos
Regulação da Temperatura Corporal , Proteínas de Caenorhabditis elegans/genética , Drosophila/fisiologia , Ácidos Graxos Dessaturases/genética , Expressão Gênica , Deleção de Sequência , Aclimatação , Animais , Animais Geneticamente Modificados , Ácidos Graxos Dessaturases/metabolismo , Ácidos Graxos/metabolismo , Neurônios/metabolismo , Fosfolipídeos , Canal de Cátion TRPA1/genética , Canal de Cátion TRPA1/metabolismo
3.
J Infect Chemother ; 25(9): 657-668, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31196772

RESUMO

The nationwide surveillance on antimicrobial susceptibility of bacterial respiratory pathogens from the patients in Japan was conducted by Japanese Society of Chemotherapy, the Japanese Association for Infectious Diseases, and the Japanese Society for Clinical Microbiology in 2014. The isolates were collected from clinical specimens obtained from well-diagnosed adult patients with respiratory tract infections during the period between January 2014 and April 2015 by three societies. Antimicrobial susceptibility testing was conducted at the central reference laboratory according to the method recommended by Clinical Laboratory Standards Institute. Susceptibility testing was evaluated in 1534 strains (335 Staphylococcus aureus, 264 Streptococcus pneumoniae, 29 Streptococcus pyogenes, 281 Haemophilus influenzae, 164 Moraxella catarrhalis, 207 Klebsiella pneumoniae, and 254 Pseudomonas aeruginosa). Ratio of methicillin-resistant S. aureus was 43.6%, and those of penicillin-susceptible S. pneumoniae was 100%. Among H. influenzae, 8.2% of them were found to be ß-lactamase-producing ampicillin-resistant strains, and 49.1% to be ß-lactamase-non-producing ampicillin-resistant strains. Extended spectrum ß-lactamase-producing K. pneumoniae and multi-drug resistant P. aeruginosa with metallo ß-lactamase were 9.2% and 0.4%, respectively.


Assuntos
Antibacterianos/uso terapêutico , Farmacorresistência Bacteriana , Monitoramento Epidemiológico , Infecções Respiratórias/prevenção & controle , Gestão de Antimicrobianos , Haemophilus influenzae/efeitos dos fármacos , Humanos , Japão/epidemiologia , Klebsiella pneumoniae/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Moraxella catarrhalis/efeitos dos fármacos , Pseudomonas aeruginosa/efeitos dos fármacos , Infecções Respiratórias/microbiologia , Streptococcus pneumoniae/efeitos dos fármacos , Streptococcus pyogenes/efeitos dos fármacos
4.
J Infect Chemother ; 23(9): 587-597, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28669567

RESUMO

The nationwide surveillance on antimicrobial susceptibility of bacterial respiratory pathogens from the patients in Japan was conducted by Japanese Society of Chemotherapy, Japanese association for infectious diseases and Japanese society for Clinical Microbiology in 2012. The isolates were collected from clinical specimens obtained from well-diagnosed adult patients with respiratory tract infections during the period between January and December in 2012 by three societies. Antimicrobial susceptibility testing was conducted at the central reference laboratory according to the method recommended by Clinical Laboratory Standard Institutes. Susceptibility testing was evaluated in 1236 strains (232 Staphylococcus aureus, 225 Streptococcus pneumoniae, 16 Streptococcus pyogenes, 231 Haemophilus influenzae, 147 Moraxella catarrhalis, 167 Klebsiella pneumoniae and 218 Pseudomonas aeruginosa). Ratio of methicillin-resistant S. aureus was 51.3%, and those of penicillin-intermediate S. pneumoniae was 0.4%. Among H. influenzae, 5.6% of them were found to be ß-lactamase-producing ampicillin-resistant strains, and 37.2% to be ß-lactamase-non-producing ampicillin-resistant strains. Extended spectrum ß-lactamase-producing K. pneumoniae and multi-drug resistant P. aeruginosa with metallo ß-lactamase were 4.2% and 3.2%, respectively. Continuous national surveillance is important to determine the actual situation of the resistance shown by bacterial respiratory pathogens to antimicrobial agents.


Assuntos
Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Bactérias/isolamento & purificação , Sistema Respiratório/microbiologia , Infecções Respiratórias/microbiologia , Farmacorresistência Bacteriana , Haemophilus influenzae/efeitos dos fármacos , Haemophilus influenzae/isolamento & purificação , Humanos , Japão , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/isolamento & purificação , Testes de Sensibilidade Microbiana , Moraxella catarrhalis/efeitos dos fármacos , Moraxella catarrhalis/isolamento & purificação , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/isolamento & purificação , Vigilância em Saúde Pública , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/isolamento & purificação , Streptococcus pneumoniae/efeitos dos fármacos , Streptococcus pneumoniae/isolamento & purificação , Streptococcus pyogenes/efeitos dos fármacos , Streptococcus pyogenes/isolamento & purificação , beta-Lactamases/análise
5.
J Infect Chemother ; 21(6): 410-20, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25817352

RESUMO

The nationwide surveillance on antimicrobial susceptibility of bacterial respiratory pathogens from patients in Japan, was conducted by Japanese Society of Chemotherapy, Japanese Association for Infectious Diseases and Japanese Society for Clinical Microbiology in 2010. The isolates were collected from clinical specimens obtained from well-diagnosed adult patients with respiratory tract infections during the period from January and April 2010 by three societies. Antimicrobial susceptibility testing was conducted at the central reference laboratory according to the method recommended by Clinical and Laboratory Standard Institutes using maximum 45 antibacterial agents. Susceptibility testing was evaluable with 954 strains (206 Staphylococcus aureus, 189 Streptococcus pneumoniae, 4 Streptococcus pyogenes, 182 Haemophilus influenzae, 74 Moraxella catarrhalis, 139 Klebsiella pneumoniae and 160 Pseudomonas aeruginosa). Ratio of methicillin-resistant S. aureus was as high as 50.5%, and those of penicillin-intermediate and -resistant S. pneumoniae were 1.1% and 0.0%, respectively. Among H. influenzae, 17.6% of them were found to be ß-lactamase-non-producing ampicillin (ABPC)-intermediately resistant, 33.5% to be ß-lactamase-non-producing ABPC-resistant and 11.0% to be ß-lactamase-producing ABPC-resistant strains. Extended spectrum ß-lactamase-producing K. pneumoniae and multi-drug resistant P. aeruginosa with metallo ß-lactamase were 2.9% and 0.6%, respectively. Continuous national surveillance of antimicrobial susceptibility of respiratory pathogens is crucial in order to monitor changing patterns of susceptibility and to be able to update treatment recommendations on a regular basis.


Assuntos
Antibacterianos/uso terapêutico , Bactérias/efeitos dos fármacos , Infecções Bacterianas/tratamento farmacológico , Farmacorresistência Bacteriana/efeitos dos fármacos , Infecções Respiratórias/tratamento farmacológico , Infecções Respiratórias/microbiologia , Doenças Transmissíveis/tratamento farmacológico , Doenças Transmissíveis/microbiologia , Humanos , Japão , Testes de Sensibilidade Microbiana
6.
Asian Spine J ; 8(5): 680-3, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25346823

RESUMO

The diagnosis of pituitary carcinoma cannot be made easily histologically, and most cases of pituitary carcinoma are diagnosed only after the clinical detection of metastasis. Distant metastasis of pituitary tumor occurs in 0.1% to 0.2% of cases and has been reported in the liver, bone and central nervous system, with only one case of metastasis to the cauda equine reported. This study describes a rare case of the drop metastasis of adrenocorticotropic hormone-producing pituitary adenocarcinoma to the cauda equina, causing cauda equina syndrome.

7.
PLoS Genet ; 10(6): e1004437, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24967585

RESUMO

Sensory and cognitive performance decline with age. Neural dysfunction caused by nerve death in senile dementia and neurodegenerative disease has been intensively studied; however, functional changes in neural circuits during the normal aging process are not well understood. Caspases are key regulators of cell death, a hallmark of age-related neurodegeneration. Using a genetic probe for caspase-3-like activity (DEVDase activity), we have mapped age-dependent neuronal changes in the adult brain throughout the lifespan of Drosophila. Spatio-temporally restricted caspase activation was observed in the antennal lobe and ellipsoid body, brain structures required for olfaction and visual place memory, respectively. We also found that caspase was activated in an age-dependent manner in specific subsets of Drosophila olfactory receptor neurons (ORNs), Or42b and Or92a neurons. These neurons are essential for mediating innate attraction to food-related odors. Furthermore, age-induced impairments of neural transmission and attraction behavior could be reversed by specific inhibition of caspase in these ORNs, indicating that caspase activation in Or42b and Or92a neurons is responsible for altering animal behavior during normal aging.


Assuntos
Caspase 3/genética , Quimiotaxia/genética , Neurônios Receptores Olfatórios , Olfato/genética , Transmissão Sináptica/genética , Envelhecimento/genética , Envelhecimento/fisiologia , Animais , Animais Geneticamente Modificados , Apoptose/efeitos dos fármacos , Comportamento Animal/fisiologia , Mapeamento Encefálico , Caspase 3/biossíntese , Dendritos/efeitos dos fármacos , Dendritos/genética , Proteínas de Drosophila , Drosophila melanogaster/genética , Drosophila melanogaster/crescimento & desenvolvimento , Malus , Receptores Odorantes
8.
J Infect Chemother ; 17(4): 510-23, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21409533

RESUMO

For the purpose of nationwide surveillance of the antimicrobial susceptibility of bacterial respiratory pathogens collected from patients in Japan, the Japanese Society of Chemotherapy conducted a third year of nationwide surveillance during the period from January to April 2008. A total of 1,097 strains were collected from clinical specimens obtained from well-diagnosed adult patients with respiratory tract infections. Susceptibility testing was evaluable with 987 strains (189 Staphylococcus aureus, 211 Streptococcus pneumoniae, 6 Streptococcus pyogenes, 187 Haemophilus influenzae, 106 Moraxella catarrhalis, 126 Klebsiella pneumoniae, and 162 Pseudomonas aeruginosa). A total of 44 antibacterial agents, including 26 ß-lactams (four penicillins, three penicillins in combination with ß-lactamase inhibitors, four oral cephems, eight parenteral cephems, one monobactam, five carbapenems, and one penem), three aminoglycosides, four macrolides (including a ketolide), one lincosamide, one tetracycline, two glycopeptides, six fluoroquinolones, and one oxazolidinone were used for the study. Analysis was conducted at the central reference laboratory according to the method recommended by the Clinical and Laboratory Standard Institute (CLSI). The incidence of methicillin-resistant S. aureus (MRSA) was as high as 59.8%, and those of penicillin-intermediate and penicillin-resistant S. pneumoniae (PISP and PRSP) were 35.5 and 11.8%, respectively. Among H. influenzae, 13.9% of them were found to be ß-lactamase-non-producing ampicillin (ABPC)-intermediately resistant (BLNAI), 26.7% to be ß-lactamase-non-producing ABPC-resistant (BLNAR), and 5.3% to be ß-lactamase-producing ABPC-resistant (BLPAR) strains. A high frequency (76.5%) of ß-lactamase-producing strains was suspected in Moraxella catarrhalis isolates. Four (3.2%) extended-spectrum ß-lactamase-producing K. pneumoniae were found among 126 strains. Four isolates (2.5%) of P. aeruginosa were found to be metallo ß-lactamase-producing strains, including three (1.9%) suspected multidrug-resistant strains showing resistance to imipenem, amikacin, and ciprofloxacin. Continual national surveillance of the antimicrobial susceptibility of respiratory pathogens is crucial in order to monitor changing patterns of susceptibility and to be able to update treatment recommendations on a regular basis.


Assuntos
Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Infecções Bacterianas/microbiologia , Infecções Respiratórias/microbiologia , Adulto , Bactérias/isolamento & purificação , Infecções Bacterianas/epidemiologia , Farmacorresistência Bacteriana , Haemophilus influenzae/efeitos dos fármacos , Humanos , Concentração Inibidora 50 , Japão/epidemiologia , Klebsiella pneumoniae/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Moraxella catarrhalis/efeitos dos fármacos , Vigilância da População , Pseudomonas aeruginosa/efeitos dos fármacos , Infecções Respiratórias/epidemiologia , Streptococcus pneumoniae/efeitos dos fármacos
9.
Mod Rheumatol ; 21(3): 320-4, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21174143

RESUMO

A 69-year-old man presented shortness of breath and acute renal failure. He had undergone pulmonary partial resection for lung cancer 5 months prior. On examination, severe hypertension, skin sclerosis of his forearms, and anticentromere antibody were observed. A renal biopsy specimen showed characteristic findings for scleroderma renal crisis, and a right heart catheterization revealed severe pulmonary arterial hypertension. Re-examination of the resected lung specimen revealed sclerodermatous vascular involvement was present.


Assuntos
Injúria Renal Aguda/patologia , Hipertensão Pulmonar/patologia , Fibrose Pulmonar/patologia , Escleroderma Sistêmico/patologia , Idoso , Biópsia , Humanos , Hipertensão Pulmonar/diagnóstico por imagem , Rim/patologia , Pulmão/diagnóstico por imagem , Pulmão/patologia , Masculino , Fibrose Pulmonar/diagnóstico por imagem , Fatores de Tempo , Tomografia Computadorizada por Raios X
10.
Chem Commun (Camb) ; (23): 3363-5, 2009 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-19503871

RESUMO

The stereocontrolled synthetic procedure for the preparation of 2,4,5-trisubstituted 2,5-chiral 1,2,5,6-tetrahydropyridines was established using a one-pot asymmetric azaelectrocyclization protocol; the generality of this protocol was demonstrated by synthesizing the title compounds with various aryl and alkenyl substituents at the C-2 position.

11.
Science ; 323(5922): 1740-3, 2009 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-19325118

RESUMO

Temperature affects the physiology, behavior, and evolution of organisms. We conducted mutagenesis and screens for mutants with altered temperature preference in Drosophila melanogaster and identified a cryophilic (cold-seeking) mutant, named atsugari (atu). Reduced expression of the Drosophila ortholog of dystroglycan (DmDG) induced tolerance to cold as well as preference for the low temperature. A sustained increase in mitochondrial oxidative metabolism caused by the reduced expression of DmDG accounted for the cryophilic phenotype of the atu mutant. Although most ectothermic animals do not use metabolically produced heat to regulate body temperature, our results indicate that their thermoregulatory behavior is closely linked to rates of mitochondrial oxidative metabolism and that a mutation in a single gene can induce a sustained change in energy homeostasis and the thermal responses.


Assuntos
Temperatura Baixa , Proteínas de Drosophila/fisiologia , Drosophila melanogaster/fisiologia , Distroglicanas/fisiologia , Metabolismo Energético , Trifosfato de Adenosina/metabolismo , Animais , Animais Geneticamente Modificados , Regulação da Temperatura Corporal , Cálcio/metabolismo , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Distroglicanas/genética , Homeostase , Mitocôndrias/metabolismo , Proteínas Mutantes , Mutação , Consumo de Oxigênio , Fenótipo , Complexo Piruvato Desidrogenase/metabolismo , Temperatura
12.
Nihon Kokyuki Gakkai Zasshi ; 45(11): 836-43, 2007 Nov.
Artigo em Japonês | MEDLINE | ID: mdl-18051784

RESUMO

We evaluated the usefulness of domestic and foreign guidelines for the diagnosis and treatment of patients with community-acquired-pneumonia at 23 institutions in 6 prefectures of the Tohoku Area, from December 2003 to November 2004. Based on the old and new Japanese Respiratory Society (JRS) guidelines, we evaluated severity, clinical efficacy and detection of atypical pneumonia. As for severity, the old guidelines led to the diagnosis of an excessive number of 'severe' cases. On the other hand, patients were appropriately diagnosed as having mild, moderate, severe, or very severe disease based on the new JRS guidelines (2005). The severity classification often correlated with the Pneumonia Severity Index (PSI) of the IDSA guidelines. The efficacy rate for patients who were prescribed the recommended drug according to the old JRS guidelines was 85.7% and for those who did not use the recommended drug it was 68.7% (p < 0.001).


Assuntos
Infecções Comunitárias Adquiridas , Guias como Assunto , Pneumonia Bacteriana , Infecções Comunitárias Adquiridas/diagnóstico , Infecções Comunitárias Adquiridas/terapia , Feminino , Humanos , Japão , Masculino , Pneumonia Bacteriana/diagnóstico , Pneumonia Bacteriana/terapia , Sociedades Médicas
13.
FEBS Lett ; 565(1-3): 43-7, 2004 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-15135050

RESUMO

Drosophila PTEN (dPTEN) plays indispensable roles in the development of Drosophila melanogaster by controlling cell size and number. Although three potential spliced forms of dPTEN have been isolated, functional distinction among these forms remains elusive. In this study, we demonstrate that all spliced forms of dPTEN dephosphorylate phosphatidylinositol 3,4,5-trisphosphate (PI(3,4,5)P(3)); however, PI(3,4,5)P(3)-dependent activation of Drosophila Akt is suppressed specifically by one of three spliced forms, dPTEN3. Further, dPTEN3 dramatically changes its expression during the Drosophila development, while the other forms are expressed throughout the development. Our results suggest that dPTEN3 is the predominant spliced form that participates in PI(3,4,5)P(3)-mediated signaling pathways.


Assuntos
Processamento Alternativo , Proteínas de Drosophila/química , Inibidores de Fosfoinositídeo-3 Quinase , Monoéster Fosfórico Hidrolases/química , Transdução de Sinais , Animais , Linhagem Celular , DNA Complementar/metabolismo , Proteínas de Drosophila/metabolismo , Drosophila melanogaster , Glutationa Transferase/metabolismo , Microscopia Confocal , Mutação , PTEN Fosfo-Hidrolase , Fosfatidilinositol 3-Quinases/metabolismo , Fosfatos de Fosfatidilinositol/metabolismo , Monoéster Fosfórico Hidrolases/metabolismo , Fosforilação , Plasmídeos/metabolismo , RNA Mensageiro/metabolismo , Proteínas Recombinantes/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Tempo , Transfecção
14.
J Neurochem ; 82(5): 1018-28, 2002 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12358749

RESUMO

Nadrin is a GTPase-activating protein (GAP) for the rho family of GTPases that controls Ca2+-dependent exocytosis in nerve endings. In this study, three novel splice variants of nadrin were identified and the variants were designated as nadrin-102, -104, -116 and -126 according to their relative molecular masses. All nadrin variants share the GAP domain, coiled-coil domain, serine/threonine/proline-rich domain, SH3-binding motif, and a successive repeat of 29 glutamines. Tissue distribution analyses using polyclonal antibodies that can discriminate each variant showed that the expression of nadrin-102, -104 and -116 was dominant in neuronal tissues and correlates well with the differentiation of neurons while nadrin-126 was strongly expressed in embryonic brain. Expression of nadrin-116 in PC12 cells strongly inhibited NGF-dependent neurite outgrowth and this effect was dependent on its GAP activity. In contrast, no significant effect on either cell morphology or neurite outgrowth was observed with other variants. All variants showed punctate appearance throughout the cytoplasm, while the 66-kDa carboxyl-terminal fragment of nadrin-102 and/or nadrin-116 was localized to the nucleus and its nuclear translocation was accelerated by NGF-induced differentiation of the cells. These results suggested that nadrin variants are different in their ability to regulate rho-mediated signaling and that, in addition to being a GTPase-activating protein, nadrin-102 and -116 have other distinct functions in the nucleus of the cell, implying a possible role in the cross-talk between the cytoskeleton and the nucleus.


Assuntos
Proteínas Ativadoras de GTPase/genética , Proteínas Ativadoras de GTPase/metabolismo , Proteínas rho de Ligação ao GTP/metabolismo , Processamento Alternativo , Sequência de Aminoácidos , Animais , Clonagem Molecular , Feminino , Proteínas Ativadoras de GTPase/farmacologia , Immunoblotting , Dados de Sequência Molecular , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Proteínas do Tecido Nervoso/farmacologia , Neuritos/efeitos dos fármacos , Especificidade de Órgãos , Células PC12 , Feocromocitoma/metabolismo , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Isoformas de Proteínas/farmacologia , RNA Mensageiro/metabolismo , Ratos , Ratos Wistar , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Homologia de Sequência de Aminoácidos , Frações Subcelulares/química , Transfecção
15.
Eur J Biochem ; 269(18): 4524-32, 2002 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12230564

RESUMO

The alpha 3 beta 1 integrin is an adhesion receptor for extracellular matrix proteins including isoforms of laminin, and the changes of its expression level in various cancer cells are thought to cause their malignant phenotypes. We have cloned an approximately 4 kb DNA fragment of the 5'-flanking region of the murine alpha 3 integrin gene and analyzed its promoter activity. Transfection of MKN1 gastric carcinoma cells with serially truncated segments of the 5'-flanking region linked to a luciferase gene indicated that a 537-bp SalI/SacI fragment upstream of exon 1 was sufficient to promote high level gene expression. By 5'-rapid amplification of cDNA ends (5'-RACE) using a cap site-labeled cDNA library, we determined one major and one minor transcription start sites in this region. The murine alpha 3 integrin gene was found to contain a CCAAT box, but to lack a TATA box. Luciferase assay following transfection with a series of deletion constructs of the SalI/SacI fragment revealed that the sequence between positions -260 and -119 bp (relative to the major transcription start site) is required for efficient transcription in gastric carcinoma cells. The sequence analysis of this segment showed the presence of several consensus sequences for transcription factors including Ets, GATA and MyoD/E-box binding factors. The introduction of mutation in one of the Ets-binding sequences greatly decreased its promoter activity, suggesting that the transcription of the alpha 3 integrin gene in these cells is regulated by the Ets-family of transcription factors.


Assuntos
Regulação Neoplásica da Expressão Gênica , Integrina alfa3beta1/genética , Regiões Promotoras Genéticas , Fatores de Transcrição/metabolismo , Região 5'-Flanqueadora , Sequência de Aminoácidos , Animais , Sequência de Bases , DNA de Neoplasias , Eletroforese em Gel de Poliacrilamida , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Dados de Sequência Molecular , Mutação , Análise de Sequência de DNA , Deleção de Sequência , Sítio de Iniciação de Transcrição , Células Tumorais Cultivadas
16.
J Org Chem ; 67(17): 5981-6, 2002 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-12182632

RESUMO

The Grignard coupling of 2,2-dibromo-1-phenyladamantane gave trans-2,2'-bi(1-phenyladamantylidene) (1-Ph). Single-crystal X-ray analysis indicated that 1-Ph has a 23.2 degrees twisted double bond, which is much more distorted than that of parent 2,2'-biadamantylidene (1-H) and that of the ethyl-substituted derivative (1-Et). A cyclic voltammogram showed a reversible electron oxidation wave at 0.87 V vs Fc/Fc(+), which is 0.19 V lower than 1-H, indicating a significant increase in the HOMO energy level due to the distortion. The reaction of 1-Ph with 0.9 equiv of bromine gave an intramolecular Friedel-Crafts alkylation product, while bromination of 1-H and 1-Me has been reported to give a bridged bromonium ion and a rearranged product, 2-(1-methyl-2-adamantylidene)-4-bromotricyclo[5,3,1,0(3.9)]undec-4-ene, respectively.

17.
Clin Exp Metastasis ; 19(2): 127-34, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-11964076

RESUMO

We evaluated the role of soluble factors produced from epidermal cells in melanoma cell motility by using the Boyden chamber chemoinvasion system. The migration of two melanoma cell lines, A375 and Mewo, was potentiated by conditioned media of A431 epidermoid cells in a concentration-dependent manner. The enhancement of A375 melanoma cell motility induced by the conditioned medium was blocked by antibodies against either alpha3 or beta1 integrin subunit. The motility-stimulating activity was recovered in the same fraction as the alpha3 integrin-dependent adhesion-promoting activity in a high-molecular-weight (>200 kDa) fraction on Superose 12 gel chromatography, and adsorbed with an anti-laminin-5 antibody. Purified laminin-5 was capable of potentiating melanoma cell migration as measured in either the chemotaxis assay with a soluble form of laminin-5 or the haptotaxis assay with membranes coated with a mixture of laminin-5 and Matrigel. Furthermore, immobilized laminin-5 induced A375 melanoma cells to secrete matrix metalloproteinase-9 (type IV collagenase) into the culture medium. These results strongly suggest that the interaction of laminin-5 produced in the epidermis with alpha3beta1 integrin on melanoma cells is involved in cell migration, invasion, and degradation of extracellular matrix proteins.


Assuntos
Moléculas de Adesão Celular/metabolismo , Movimento Celular/fisiologia , Integrinas/metabolismo , Melanoma/metabolismo , Neoplasias Cutâneas/metabolismo , Moléculas de Adesão Celular/farmacologia , Colágeno/química , Meios de Cultivo Condicionados , Combinação de Medicamentos , Citometria de Fluxo , Gelatina/metabolismo , Humanos , Integrina alfa3beta1 , Laminina/química , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Melanoma/patologia , Invasividade Neoplásica , Proteoglicanas/química , Proteínas Recombinantes/metabolismo , Neoplasias Cutâneas/patologia , Células Tumorais Cultivadas/efeitos dos fármacos , Células Tumorais Cultivadas/patologia , Calinina
18.
Chem Commun (Camb) ; (24): 3062-3, 2002 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-12536817

RESUMO

Thermodynamic stabilities of alkylated C60 cations (RC60+) were determined based on the activation free energies of SN1 solvolysis of the title compounds, indicating that these cations have stabilities comparable to that of the tert-butyl cation.

20.
J Org Chem ; 64(8): 2821-2829, 1999 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-11674351

RESUMO

The structure and the stability of various cyclopentadienides, which involve 6pi, 10pi, 14pi, and 22pi electrons, are investigated from computations at various levels of theory as well as from orbital interaction analyses. The reason that some of the cyclopentadienides are stabilized and others are destabilized by the introduction of aromatic rings is discussed in terms of absolute hardness and orbital interaction. Cyclopentadienide, a special 6pi-electron system, has the largest value of absolute hardness among the condensed cyclopentadienides investigated; thus this carbanion resists both oxidation and reduction most strongly. The absolute hardness decreases when aromatic rings are introduced to cyclopentadienide to form condensed cyclopentadienides, depending on the way they are connected. Computed values of the ionization potential and oxidation potentials measured in solution have a linear correlation within isomers of the same size, but are not in agreement for different sets of isomers. Solvent effects on the ionization potential are assessed by performing self-consistent reaction field calculations, the results being in excellent agreement with experiments. It is demonstrated that the solvent effects are significant in small cyclopentadienides of 6pi- and 10pi-electron systems, compared to larger ones and that addition of condensed aromatic rings intrinsically stabilizes the formed condensed cyclopentadienides with respect to ionization potential.

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