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1.
Traffic Inj Prev ; 24(sup1): S68-S74, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37267017

RESUMO

OBJECTIVE: In this research, body technology was established for side collisions with new IIHS MDB as a representative case. In the conventional body structure, most of the load received from the barrier is absorbed by bending deformation of the door beam and B-pillar, etc. For that reason, the body is subjected to large deformation before reaching the maximum load, and the deformation increases further when subjected to a high-energy collision. Therefore, the objective of this research is to create a structure that increases the load from the initiation of impact and suppresses the deformation of the car body. METHOD: An arched door beam was developed to reduce the bending moment by the axial load in the longitudinal direction generated during the deformation and to increase the load in the lateral direction. A principle equation was developed that uses the shape of the door beam as a variable. A prototype of the arched door beam was fabricated, and its performance was evaluated by an impactor test. A full-car simulation was conducted using a mass-produced sedan as a base, to which the arched door beam was added to verify the performance of the complete vehicle. RESULTS: The results of the impactor tests were evaluated using the load gradient, which was defined as the generated load divided by the amount of deformation. Compared to conventional straight door beams, the load gradient was 7.1 times higher. Full-car simulation results showed that for a gasoline-powered vehicle body weight, the body load gradient of the proposed structure was 4.7 times higher, and the body deformation adjacent to the dummy shoulder was reduced by 210 mm. Spine acceleration of the dummy was reduced by 56%. CONCLUSION: The body structure proposed in this research has the effect of increasing the load gradient and reducing body deformation and spine acceleration. It is expected to be applicable to EVs and FCVs, which require more energy absorption due to their increased vehicle weight.


Assuntos
Aceleração , Acidentes de Trânsito , Humanos , Acidentes de Trânsito/prevenção & controle , Simulação por Computador , Coluna Vertebral , Ombro
2.
J Hypertens ; 39(12): 2521-2526, 2021 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-34738993

RESUMO

OBJECTIVE: An association between the Moyamoya disease susceptible gene ring finger protein 213 (RNF213) variant and ischemic stroke and coronary artery disease has been suggested in case-control studies. We aimed to investigate the possible association between the RNF213 variant and the incidence of cardiovascular disease in a general population. METHODS: The study participants consisted of 9153 Japanese community residents without history of cardiovascular disease. The clinical parameters employed in this analysis were observed at baseline between 2008 and 2010. The RNF213 p.R4859K variant was determined by TaqMan probe assay and then confirmed by Sanger sequencing. RESULTS: During 8.52 years follow-up period, we observed 214 incident cases of cardiovascular diseases (99 total stroke cases, 119 major adverse cardiac event cases, including 4 cases of both). The incidence rate was higher for the variant allele carriers (120 cases; incidence rate, 71.0 per 10 000 person-years) than for the homozygotes of the wild-type allele (26.9), and the group differences achieved statistical significance (P = 0.009). Although the RNF213 variant was also associated with systolic blood pressure (dominant model: coefficient of 8.19 mmHg; P < 0.001), the Cox regression analysis adjusted for major covariates including systolic blood pressure identified the RNF213 variant as an independent determinant for cardiovascular disease (hazard ratio of 3.41, P = 0.002) and major adverse cardiac event (hazard ratio of 3.80, P = 0.010) but not with total stroke (P = 0.102). CONCLUSION: The Moyamoya disease susceptible RNF213 variant was associated with blood pressure and the incidence of cardiovascular disease in a Japanese general population.


Assuntos
Adenosina Trifosfatases , Doenças Cardiovasculares , Doença de Moyamoya , Ubiquitina-Proteína Ligases , Adenosina Trifosfatases/genética , Alelos , Doenças Cardiovasculares/epidemiologia , Doenças Cardiovasculares/genética , Predisposição Genética para Doença , Humanos , Japão , Doença de Moyamoya/epidemiologia , Doença de Moyamoya/genética , Ubiquitina-Proteína Ligases/genética
3.
J Med Chem ; 63(17): 9003-9019, 2020 09 10.
Artigo em Inglês | MEDLINE | ID: mdl-32407089

RESUMO

Formyl peptide receptor 2 (FPR2) agonists can stimulate resolution of inflammation and may have utility for treatment of diseases caused by chronic inflammation, including heart failure. We report the discovery of a potent and selective FPR2 agonist and its evaluation in a mouse heart failure model. A simple linear urea with moderate agonist activity served as the starting point for optimization. Introduction of a pyrrolidinone core accessed a rigid conformation that produced potent FPR2 and FPR1 agonists. Optimization of lactam substituents led to the discovery of the FPR2 selective agonist 13c, BMS-986235/LAR-1219. In cellular assays 13c inhibited neutrophil chemotaxis and stimulated macrophage phagocytosis, key end points to promote resolution of inflammation. Cardiac structure and functional improvements were observed in a mouse heart failure model following treatment with BMS-986235/LAR-1219.


Assuntos
Pirrolidinonas/química , Receptores de Formil Peptídeo/agonistas , Receptores de Lipoxinas/agonistas , Animais , Quimiotaxia/efeitos dos fármacos , Modelos Animais de Doenças , Avaliação Pré-Clínica de Medicamentos , Células HEK293 , Insuficiência Cardíaca/patologia , Insuficiência Cardíaca/prevenção & controle , Humanos , Macrófagos/citologia , Macrófagos/imunologia , Macrófagos/metabolismo , Camundongos , Microssomos Hepáticos/metabolismo , Neutrófilos/citologia , Neutrófilos/fisiologia , Fagocitose/efeitos dos fármacos , Pirrolidinonas/metabolismo , Pirrolidinonas/farmacologia , Pirrolidinonas/uso terapêutico , Receptores de Formil Peptídeo/genética , Receptores de Formil Peptídeo/metabolismo , Receptores de Lipoxinas/genética , Receptores de Lipoxinas/metabolismo , Relação Estrutura-Atividade
4.
Artigo em Inglês | MEDLINE | ID: mdl-26262228

RESUMO

In Japan, most of all the university and advanced hospitals have implemented both electronic order entry systems and electronic charting. In addition, all medical records are subjected to inspector audit for quality assurance. The record of informed consent (IC) is very important as this provides evidence of consent from the patient or patient's family and health care provider. Therefore, we developed an automatic audit system for a hospital information system (HIS) that is able to evaluate IC automatically using machine learning.


Assuntos
Consentimento Livre e Esclarecido , Aprendizado de Máquina , Auditoria Médica/métodos , Registros Eletrônicos de Saúde , Humanos , Sistemas Computadorizados de Registros Médicos
5.
Sci Rep ; 4: 4828, 2014 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-24797416

RESUMO

Periodontitis has been implicated as a risk factor for metabolic disorders such as type 2 diabetes, atherosclerotic vascular diseases, and non-alcoholic fatty liver disease. Although bacteremias from dental plaque and/or elevated circulating inflammatory cytokines emanating from the inflamed gingiva are suspected mechanisms linking periodontitis and these diseases, direct evidence is lacking. We hypothesize that disturbances of the gut microbiota by swallowed bacteria induce a metabolic endotoxemia leading metabolic disorders. To investigate this hypothesis, changes in the gut microbiota, insulin and glucose intolerance, and levels of tissue inflammation were analysed in mice after oral administration of Porphyromonas gingivalis, a representative periodontopathogens. Pyrosequencing revealed that the population belonging to Bacteroidales was significantly elevated in P. gingivalis-administered mice which coincided with increases in insulin resistance and systemic inflammation. In P. gingivalis-administered mice blood endotoxin levels tended to be higher, whereas gene expression of tight junction proteins in the ileum was significantly decreased. These results provide a new paradigm for the interrelationship between periodontitis and systemic diseases.


Assuntos
Íleo/metabolismo , Íleo/microbiologia , Inflamação/metabolismo , Inflamação/microbiologia , Doenças Metabólicas/metabolismo , Doenças Metabólicas/microbiologia , Animais , Citocinas/metabolismo , Placa Dentária/microbiologia , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/microbiologia , Diabetes Mellitus Tipo 2/patologia , Modelos Animais de Doenças , Endotoxemia/metabolismo , Endotoxemia/microbiologia , Endotoxemia/patologia , Gengiva/metabolismo , Gengiva/microbiologia , Gengiva/patologia , Intolerância à Glucose/metabolismo , Intolerância à Glucose/microbiologia , Intolerância à Glucose/patologia , Íleo/patologia , Inflamação/patologia , Insulina/metabolismo , Resistência à Insulina/fisiologia , Masculino , Doenças Metabólicas/patologia , Camundongos , Camundongos Endogâmicos C57BL , Microbiota , Periodontite/metabolismo , Periodontite/microbiologia , Periodontite/patologia , Porphyromonas gingivalis , Proteínas de Junções Íntimas/metabolismo
6.
Mod Rheumatol ; 24(1): 120-8, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24261768

RESUMO

OBJECTIVES: Various inflammatory cytokines, including tumor necrosis factor-α (TNF-α), have been reported to play roles in Kawasaki disease (KD). Recently, anti-TNF-α therapy was reported to show efficacy in patients who do not respond to high-dose intravenous immunoglobulin therapy. However, there are many gaps in our understanding of the role that TNF-α plays in the development of KD arteritis as well as whether anti-TNF-α therapy causes any histological changes in the arteritis. Accordingly, the present histopathological study was carried out to elucidate the inhibitory effect of anti-TNF-α therapy on vasculitis as well as the role of TNF-α in the development of vasculitis in a murine model of KD vasculitis. METHODS: We used two anti-TNF-α drugs (etanercept and infliximab) to treat a Candida albicans-induced murine model of KD vasculitis. We investigated the histopathological changes in terms of the incidence of vasculitis, the scope of lesions and the degree of inflammation. RESULTS: Administration of etanercept to the mice reduced not only the incidence of vasculitis but also the scope of lesions and the degree of inflammation. CONCLUSION: Based on the histological findings, TNF-α is deeply involved in the development of vasculitis.


Assuntos
Anticorpos Monoclonais/uso terapêutico , Arterite/tratamento farmacológico , Imunoglobulina G/uso terapêutico , Síndrome de Linfonodos Mucocutâneos/tratamento farmacológico , Receptores do Fator de Necrose Tumoral/uso terapêutico , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Animais , Arterite/induzido quimicamente , Arterite/patologia , Candida albicans , Modelos Animais de Doenças , Etanercepte , Infliximab , Camundongos , Síndrome de Linfonodos Mucocutâneos/induzido quimicamente , Síndrome de Linfonodos Mucocutâneos/patologia , Miocárdio/patologia , Polissacarídeos , Fator de Necrose Tumoral alfa/metabolismo
7.
Chem Commun (Camb) ; 49(95): 11221-3, 2013 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-24150697

RESUMO

Tagetitoxin is an unusually densely functionalized natural product, consisting of an unprecedented oxathiabicyclo[3.3.1]nonane ring system possessing acetate, phosphate, amide, carboxylic acid, and amine groups with six contiguous asymmetric centers. A fully functionalized core structure of tagetitoxin was synthesized from tri-O-acetyl-D-galactal in a highly stereoselective manner.


Assuntos
Compostos Bicíclicos com Pontes/química , Ácidos Dicarboxílicos/química , Compostos Organofosforados/química , Ácidos Dicarboxílicos/síntese química , Galactose/análogos & derivados , Galactose/química , Hidroxilação , Compostos Organofosforados/síntese química , Estereoisomerismo
8.
Chem Asian J ; 8(7): 1428-35, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23670825

RESUMO

The total synthesis of polygalolide A, a secondary metabolite that was isolated from a Chinese medicinal plant, is reported. A key issue in this synthesis was construction of an oxabicyclo[3.2.1] skeleton, which was solved by the development of an intramolecular Ferrier-type C-glycosylation of a glucal with siloxyfuran as an internal nucleophile. The substrate was prepared from D-glucal by the introduction of trimethylsilylacetylene and siloxyfuran groups. Although C-glycosylation did not occur under the conditions found from model experiments, further examination revealed that the combination of trimethylsilyl trifluoromethanesulfonate (TMSOTf) and 2,4,6-collidine successfully afforded the desired product as a single diastereomer. The siloxy group at the C3 position played a crucial role in the stereocontrol of this reaction. The product was further transformed into a tetracyclic compound as follows: The vinyl ether and acetylenic moieties were reduced and the siloxy group was removed with a Barton-McCombie reaction. The construction of the six-membered ether and the γ-lactone provided the tetracyclic compound. Finally, a phenolic moiety was introduced by using a Mukaiyama aldol reaction to furnish polygalolide A.


Assuntos
Fenóis/síntese química , Alcenos/química , Cristalografia por Raios X , Glicosilação , Conformação Molecular , Fenóis/química , Plantas Medicinais/química , Polygala/química , Estereoisomerismo
9.
Org Lett ; 14(17): 4510-3, 2012 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-22900799

RESUMO

The acid-catalyzed condensation reaction of resorcinol and bisdimethoxyacetals gave rise to rim-to-rim connected bisresorcinarenes in good yields. In the presence of ethanol, the homoditopic bisresorcinarenes assembled to form supramolecular polymers via hydrogen bonding interactions. The fibrous morphologies of the supramolecular polymers were confirmed by atomic force microscopy and scanning electron microscopy.

10.
Circ J ; 76(4): 964-70, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22313802

RESUMO

BACKGROUND: The objectives of this study were to clarify the details of pediatric vasculitic diseases on the basis of Japanese autopsy reports and determine whether there were cases of probable Kawasaki disease (KD) even before KD came to be widely recognized as a disease entity. METHODS AND RESULTS: Systemic vasculitis autopsy cases aged 15 years or less were selected from the total of 1,335,045 autopsy cases listed in the Annual of Pathological Autopsy Cases in Japan from 1958 through 2008. Those cases were classified into 14 disease groups and then analyzed with regard to various details. There were 380 autopsy cases of vasculitis in children (0.03% of the total autopsy cases). More than half were KD, and other diseases included unclassified vasculitis, polyarteritis nodosa, purpuric vasculitis, Takayasu arteritis, etc. The first recorded case of KD autopsy occurred in 1969. Up until 1976 there was a great difference in the number of autopsies between pediatric vasculitis and KD. However, after 1977 their numbers were in close agreement. The autopsy findings for 24 of 125 child vasculitis autopsies performed before 1976 and diagnosed as non-KD were consistent with KD. CONCLUSIONS: Although autopsies of pediatric vasculitis cases are extremely rare, the majority consists of KD. Moreover, it is likely that autopsy cases that were probably KD first appeared in the early 1960s.


Assuntos
Síndrome de Linfonodos Mucocutâneos/epidemiologia , Vasculite/epidemiologia , Adolescente , Fatores Etários , Autopsia , Criança , Pré-Escolar , Feminino , Humanos , Incidência , Lactente , Recém-Nascido , Japão/epidemiologia , Masculino , Síndrome de Linfonodos Mucocutâneos/classificação , Síndrome de Linfonodos Mucocutâneos/patologia , Fatores de Tempo , Vasculite/classificação , Vasculite/patologia
11.
Org Lett ; 14(1): 114-7, 2012 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-22126279

RESUMO

Two possible diastereomers of the indole moiety of sespendole were synthesized from 3-hydroxy-4-nitrobenzaldehyde in a highly stereoselective manner. Comparison of (1)H and (13)C NMR spectra of the two synthetic materials with those sespendole leads us to propose that the relative stereochemistry of the epoxyalcohol is syn.


Assuntos
Diterpenos/química , Indóis/síntese química , Indóis/química , Estrutura Molecular , Estereoisomerismo
12.
Org Lett ; 13(24): 6532-5, 2011 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-22092027

RESUMO

The total synthesis of polygalolide A was accomplished through intramolecular C-glycosylation of glucal modified with siloxyfuran. The siloxyfuran group and siloxy substituent at the C-3 position played crucial roles in allowing direct access to the highly substituted oxabicyclo[3.2.1] core skeleton with correct quaternary stereogenic centers.


Assuntos
Fenóis/síntese química , Glicosilação , Estrutura Molecular , Fenóis/química , Estereoisomerismo
13.
Pediatr Rheumatol Online J ; 9(1): 30, 2011 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-21958311

RESUMO

UNLABELLED: The incidence of panvasculitis in the coronary arteries and aortic root was 100% in the control group. The incidence of panvasculitis in the MZR group decreased to 50%. Moreover, the scope and severity of the inflammation of those sites were significantly reduced in the MZR group as well as the IgG group. On the other hand, increased cytokines and chemokines, such as IL-1α, TNF-α, KC, MIP-1α, GM-CSF, and IL-13, in the nontreatment group were significantly suppressed by treatment with MZR, but the MCP-1 level increased. In addition, IL-1α, TNF-α, IL-10, IL-13, and MIP-1α were suppressed by treatment in the IgG group. BACKGROUND: Intravenous immunoglobulin (IVIg) treatment results in an effective response from patients with acute-phase Kawasaki disease (KD), but 16.5% of them remain nonresponsive to IVIg. To address this therapeutic challenge, we tried a new therapeutic drug, mizoribine (MZR), in a mouse model of KD, which we have established using injections of Candida albicans water-soluble fractions (CAWS). METHODS: CAWS (4 mg/mouse) were injected intraperitoneally into C57BL/6N mice for 5 consecutive days. MZR or IgG was administered for 5 days. After 4 weeks, the mice were sacrificed and autopsied, the hearts were fixed in 10% neutral formalin, and plasma was taken to measure cytokines and chemokines using the Bio-Plex system. RESULTS: The incidence of panvasculitis in the coronary arteries and aortic root was 100% in the control group. The incidence of panvasculitis in the MZR group decreased to 50%. Moreover, the scope and severity of the inflammation of those sites were significantly reduced in the MZR group as well as the IgG group. On the other hand, increased cytokines and chemokines, such as IL-1α TNF-α, KC, MIP-1α, GM-CSF, and IL-13, in the nontreatment group were significantly suppressed by treatment with MZR, but the MCP-1 level increased. In addition, IL-1α, TNF-α, IL-10, IL-13, and MIP-1α were suppressed by treatment in the IgG group. CONCLUSION: MZR treatment suppressed not only the incidence, range, and degree of vasculitis, but also inflammatory cytokines and chemokines in the plasma of the KD vasculitis model mice, suggesting that MZR may be useful for treatment of KD.

14.
Stud Health Technol Inform ; 164: 117-21, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21335697

RESUMO

Document management systems (DMS) have widespread in major hospitals in Japan as a platform to digitize the paper-based records being out of coverage by EPR. This study aimed to examine longitudinal trends of actual use of DMS in a hospital in which EPR had been in operation, which would be conducive to planning the further information management system in the hospital. Degrees of utilization of electronic documents and templates with DMS were analyzed based on data extracted from a university-affiliated hospital with EPR. As a result, it was found that the number of electronic documents as well as scanned documents circulating at the hospital tended to increase. The result indicated that replacement of paper-based documents with electronic documents did not occur. Therefore it was anticipated that the need for DMS would continue to increase in the hospital. The methods used this study to analyze the trend of DMS utilization would be applicable to other hospitals with with a variety of DMS implementation, such as electronic storage by scanning documents or paper preservation that is compatible with EPR.


Assuntos
Registros Eletrônicos de Saúde/estatística & dados numéricos , Sistemas de Informação Hospitalar , Humanos , Japão , Estudos Longitudinais
15.
J Agric Food Chem ; 53(4): 1022-30, 2005 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-15713015

RESUMO

To reveal the signal transduction mechanism of the response to stress in the form of active oxygen species, we used a microarray system to analyze gene expression patterns 2 or 24 h after gamma-irradiation of Arabidopsis. gamma-Irradiation induces several signal transduction and metabolite genes. By analysis of cis-elements located on the promoter region of the gamma-responsive genes, we have also found several cis-elements related to various signal transduction systems. We also analyzed the pleiotropic mutant ttg1-1, which has a dramatically altered physiological response to gamma-irradiation. By comparing the gene expression patterns of wild-type (Ler) and ttg1-1 mutant plants after gamma-irradiation, we identified various TTG1-regulated gamma-response genes. Analysis of the cis-elements in the promoter region of the gamma-responsive genes also revealed that the many transcription factors interacting with TTG1 protein (WD40 protein) are related to the gamma-responsive gene expression.


Assuntos
Arabidopsis/genética , Raios gama , Expressão Gênica/efeitos da radiação , Genes de Plantas/efeitos da radiação , Análise de Sequência com Séries de Oligonucleotídeos , Proteínas de Arabidopsis/genética , Mutação , RNA de Plantas/análise
16.
Science ; 301(5631): 376-9, 2003 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-12869764

RESUMO

We collected and completely sequenced 28,469 full-length complementary DNA clones from Oryza sativa L. ssp. japonica cv. Nipponbare. Through homology searches of publicly available sequence data, we assigned tentative protein functions to 21,596 clones (75.86%). Mapping of the cDNA clones to genomic DNA revealed that there are 19,000 to 20,500 transcription units in the rice genome. Protein informatics analysis against the InterPro database revealed the existence of proteins presented in rice but not in Arabidopsis. Sixty-four percent of our cDNAs are homologous to Arabidopsis proteins.


Assuntos
Genoma de Planta , Oryza/genética , Análise de Sequência de DNA , Processamento Alternativo , Sequência de Aminoácidos , Clonagem Molecular , Biologia Computacional , DNA Complementar , Bases de Dados de Ácidos Nucleicos , Bases de Dados de Proteínas , Genes de Plantas , Dados de Sequência Molecular , Fases de Leitura Aberta , Proteínas de Plantas/química , Proteínas de Plantas/genética , Proteínas de Plantas/fisiologia , Estrutura Terciária de Proteína , RNA Antissenso/genética , Homologia de Sequência de Aminoácidos , Homologia de Sequência do Ácido Nucleico , Fatores de Transcrição/química , Fatores de Transcrição/genética , Transcrição Gênica
17.
Genome Biol ; 5(1): R5, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-14709177

RESUMO

BACKGROUND: Natural antisense transcripts control gene expression through post-transcriptional gene silencing by annealing to the complementary sequence of the sense transcript. Because many genome and mRNA sequences have become available recently, genome-wide searches for sense-antisense transcripts have been reported, but few plant sense-antisense transcript pairs have been studied. The Rice Full-Length cDNA Sequencing Project has enabled computational searching of a large number of plant sense-antisense transcript pairs. RESULTS: We identified sense-antisense transcript pairs from 32,127 full-length rice cDNA sequences produced by this project and public rice mRNA sequences by aligning the cDNA sequences with rice genome sequences. We discovered 687 bidirectional transcript pairs in rice, including sense-antisense transcript pairs. Both sense and antisense strands of 342 pairs (50%) showed homology to at least one expressed sequence tag other than that of the pair. Microarray analysis showed 82 pairs (32%) out of 258 pairs on the microarray were more highly expressed than the median expression intensity of 21,938 rice transcriptional units. Both sense and antisense strands of 594 pairs (86%) had coding potential. CONCLUSIONS: The large number of plant sense-antisense transcript pairs suggests that gene regulation by antisense transcripts occurs in plants and not only in animals. On the basis of our results, experiments should be carried out to analyze the function of plant antisense transcripts.


Assuntos
DNA Antissenso/genética , DNA Complementar/genética , Oryza/genética , DNA Antissenso/química , DNA Antissenso/classificação , DNA Complementar/química , DNA Complementar/classificação , DNA de Plantas/química , DNA de Plantas/classificação , DNA de Plantas/genética , Perfilação da Expressão Gênica/métodos , Regulação da Expressão Gênica de Plantas/genética , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Interferência de RNA/fisiologia , RNA Antissenso/classificação , RNA Antissenso/genética , RNA Mensageiro/química , RNA Mensageiro/classificação , RNA Mensageiro/genética , RNA de Plantas/química , RNA de Plantas/classificação , RNA de Plantas/genética , Homologia de Sequência do Ácido Nucleico , Transcrição Gênica/fisiologia
18.
Int J Exp Diabetes Res ; 3(2): 131-44, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-11991199

RESUMO

Hyperinsulinemia has been shown to be associated with diabetic angiopathy. Migration and proliferation of vascular smooth muscle cells (VSMC) are the processes required for the development of atherosclerosis. In this study, we attempted to determine whether insulin affects mitogenic signaling induced by platelet-derived growth factor (PDGF) in a rat VSMC cell line (A10 cells). PDGF stimulated DNA synthesis which was totally dependent on Ras, because transfection of dominant negative Ras resulted in complete loss of PDGF-stimulated DNA synthesis. Initiation of DNA synthesis was preceded by activation of Raf-1, MEK and MAP kinases (Erk 1 and Erk2). Treatment of the cells with PD98059, an inhibitor of MAPK kinase (MEK) attenuated but did not abolish PDGF-stimulated DNA synthesis, suggesting that MAPK is required but not essential for DNA synthesis. PDGF also stimulated phosphorylation of protein kinase B (Akt/PKB) and p70 S6Kinase (p70S6K) in a wortmannin-sensitive manner. Rapamycin, an inhibitor of p70S6K, markedly suppressed DNA synthesis. Low concentrations of insulin (1-10 nmol/l) alone showed little mitogenic activity and no significant effect on MAPK activity. However, the presence of insulin enhanced both DNA synthesis and MAPK activation by PDGF. The enhancing effect of insulin was not seen in cells treated with PD98059. Insulin was without effect on PDGF-stimulated activations of protein kinase B (Akt/PKB) and p70S6K. We conclude that insulin, at pathophysiologically relevant concentrations, potentiates the PDGF-stimulated DNA synthesis, at least in part, by potentiating activation of the MAPK cascade. These results are consistent with the notion that hyperinsulinemia is a risk factor for the development of atherosclerosis.


Assuntos
Sistema de Sinalização das MAP Quinases/fisiologia , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Músculo Liso Vascular/fisiologia , Fator de Crescimento Derivado de Plaquetas/farmacologia , Animais , Aorta Torácica/citologia , Aorta Torácica/efeitos dos fármacos , Aorta Torácica/fisiologia , Becaplermina , Divisão Celular/efeitos dos fármacos , Células Cultivadas , DNA/biossíntese , DNA/efeitos dos fármacos , Humanos , Insulina/farmacologia , Cinética , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Músculo Liso Vascular/citologia , Músculo Liso Vascular/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-sis , Ratos , Proteínas Recombinantes/farmacologia , Suínos , Fatores de Tempo
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