Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 28
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
J Prim Care Community Health ; 12: 21501327211030817, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34238053

RESUMO

INTRODUCTION: Providing self-management education for residents with cardiometabolic conditions in remote islands is a challenge due to the shortage of primary care practitioners (PCPs), specialist physicians, and nurses. Therefore, we applied telenursing with lifestyle-related chronic diseases in remote island residents in Japan. This project aimed to improve the self-management behavior, cardiometabolic indicators, self-efficacy, and quality of life (QoL) of residents with cardiometabolic risks. METHODS: We chose Osakikamijima Island, Hiroshima Prefecture, Japan, which is designated under the Remote Islands Development Act. The project was conducted from 2013 to 2014. The residents aged over 40 and under 75 years old, selected from the annual specific health check-up examination and from PCPs for screening cardiometabolic risks (urinary protein, glycohemoglobin A1c, systolic and diastolic blood pressure (BP), Low-density lipoprotein cholesterol, High-density lipoprotein cholesterol, and triglyceride) were included. The effectiveness of telenursing for self-management education was 6-month-long with a 6-month follow-up and evaluated by a single-group pre-and post-test design. Face-to-face health education was applied at the initial interview followed by telenursing (biweekly telephone calls till third-month, and a monthly telephone call during the fourth and fifth-month) by the trained nurses outside the island. To enhance participants' self-monitoring health behavior changes, the nurses used motivational interviewing and behavior change techniques based on the transtheoretical model. RESULTS: A total of 130 residents, 42 agreed to participate, 41 finished the 6-month program, and 33 completed the 12-month follow-up. Most of their behavior changes like self-management behaviors, cardiometabolic indicators, and self-efficacy at 6-month were improved significantly except QoL. Among the 12-month study periods, self-management behaviors, body mass index, systolic BP, diastolic BP, and self-efficacy (sense of control), (all P < .05) showed significant improvement. CONCLUSION: This study results indicated that telenursing might be effective to improve the lifestyles-related behaviors in chronic diseases on the remote island of Osakikamijima, Japan.


Assuntos
Doenças Cardiovasculares , Autogestão , Telenfermagem , Idoso , Doenças Cardiovasculares/prevenção & controle , Humanos , Japão , Projetos Piloto , Qualidade de Vida
2.
J Infect Chemother ; 27(7): 1080-1083, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33563526

RESUMO

Campylobacter jejuni and Campylobacter coli are the leading causes of bacterial intestinal infections worldwide, while Campylobacter fetus subsp. fetus (C. fetus) has been reported to cause extraintestinal infections, including medical device implant infections. However, breast implant infections have rarely been reported. We describe the case of a 64-year-old woman with breast implant infection and vertebral osteomyelitis due to C. fetus. The patient recovered by surgical removal of the infected left implant and was treated with antibiotics for 6 weeks. However, two weeks after the completion of antibiotics, she experienced an infection in the right implant due to C. fetus, which had developed quinolone resistance with a G91T mutation during the treatment course. This case showed that C. fetus can cause breast implant infections, and although the infection may appear to be unilateral initially, the possibility of sequential contralateral infection should be considered.


Assuntos
Implantes de Mama , Infecções por Campylobacter , Campylobacter , Implantes de Mama/efeitos adversos , Infecções por Campylobacter/diagnóstico , Infecções por Campylobacter/tratamento farmacológico , Campylobacter fetus/genética , Feminino , Humanos , Pessoa de Meia-Idade
3.
Metabolism ; 118: 154726, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33581131

RESUMO

BACKGROUND & AIMS: The physiological regulation and contribution of the multiple phosphorylation sites of insulin receptor substrate 1 (IRS1) to the pathogenesis of insulin resistance is unknown. Our aims were to map the phosphorylated motifs of IRS1 in skeletal muscle from people with normal glucose tolerance (NGT; n = 11) or type 2 diabetes mellitus (T2DM; n = 11). METHODS: Skeletal muscle biopsies were obtained under fasted conditions or during a euglycemic clamp and IRS1 phosphorylation sites were identified by mass spectrometry. RESULTS: We identified 33 phosphorylation sites in biopsies from fasted individuals, including 2 previously unreported sites ([Ser393] and [Thr1017]). In men with NGT and T2DM, insulin increased phosphorylation of 5 peptides covering 10 serine or threonine sites and decreased phosphorylation of 6 peptides covering 9 serine, threonine or tyrosine sites. Insulin-stimulation increased phosphorylation of 2 peptides, and decreased phosphorylation of 2 peptides only in men with NGT. Insulin increased phosphorylation of 2 peptides only in men with T2DM. CONCLUSIONS: Despite severe skeletal muscle insulin resistance, the pattern of IRS1 phosphorylation was not uniformly altered in T2DM. Our results contribute to the evolving understanding of the physiological regulation of insulin signaling and complement the comprehensive map of IRS1 phosphorylation in T2DM.


Assuntos
Diabetes Mellitus Tipo 2/metabolismo , Teste de Tolerância a Glucose , Proteínas Substratos do Receptor de Insulina/metabolismo , Músculo Esquelético/metabolismo , Fosfoproteínas/metabolismo , Proteômica/métodos , Sequência de Aminoácidos , Biópsia , Estudos de Casos e Controles , Humanos , Insulina/metabolismo , Masculino , Pessoa de Meia-Idade , Músculo Esquelético/patologia , Fosforilação , Transdução de Sinais
4.
Nat Metab ; 2(4): 307-317, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32601609

RESUMO

Aging impairs tissue repair. This is pronounced in skeletal muscle, whose regeneration by muscle stem cells (MuSCs) is robust in young adult animals but inefficient in older organisms. Despite this functional decline, old MuSCs are amenable to rejuvenation through strategies that improve the systemic milieu, such as heterochronic parabiosis. One such strategy, exercise, has long been appreciated for its benefits on healthspan, but its effects on aged stem cell function in the context of tissue regeneration are incompletely understood. Here we show that exercise in the form of voluntary wheel running accelerates muscle repair in old animals and improves old MuSC function. Through transcriptional profiling and genetic studies, we discovered that the restoration of old MuSC activation ability hinges on restoration of Cyclin D1, whose expression declines with age in MuSCs. Pharmacologic studies revealed that Cyclin D1 maintains MuSC activation capacity by repressing TGFß signaling. Taken together, these studies demonstrate that voluntary exercise is a practicable intervention for old MuSC rejuvenation. Furthermore, this work highlights the distinct role of Cyclin D1 in stem cell quiescence.


Assuntos
Ciclina D1/metabolismo , Músculo Esquelético/citologia , Condicionamento Físico Animal , Células-Tronco/citologia , Animais , Separação Celular , Transplante de Células , Citometria de Fluxo , Camundongos , Músculo Esquelético/metabolismo , Células-Tronco/metabolismo
5.
Int J Mol Sci ; 19(5)2018 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-29695130

RESUMO

Keloids occur after failure of the wound healing process; inflammation persists, and various treatments are ineffective. Keloid pathogenesis is still unclear. We have previously analysed the gene expression profiles in keloid tissue and found that HtrA1 was markedly up-regulated in the keloid lesions. HtrA1 is a serine protease suggested to play a role in the pathogenesis of various diseases, including age-related macular degeneration and osteoarthritis, by modulating extracellular matrix or cell surface proteins. We analysed HtrA1 localization and its role in keloid pathogenesis. Thirty keloid patients and twelve unrelated patients were enrolled for in situ hybridization, immunohistochemical, western blot, and cell proliferation analyses. Fibroblast-like cells expressed more HtrA1 in active keloid lesions than in surrounding lesions. The proportion of HtrA1-positive cells in keloids was significantly higher than that in normal skin, and HtrA1 protein was up-regulated relative to normal skin. Silencing HtrA1 gene expression significantly suppressed cell proliferation. HtrA1 was highly expressed in keloid tissues, and the suppression of the HtrA1 gene inhibited the proliferation of keloid-derived fibroblasts. HtrA1 may promote keloid development by accelerating cell proliferation and remodelling keloid-specific extracellular matrix or cell surface molecules. HtrA1 is suggested to have an important role in keloid pathogenesis.


Assuntos
Regulação da Expressão Gênica , Serina Peptidase 1 de Requerimento de Alta Temperatura A/genética , Queloide/genética , Queloide/patologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores , Biópsia , Proliferação de Células , Células Cultivadas , Feminino , Fibroblastos/metabolismo , Técnicas de Silenciamento de Genes , Humanos , Imuno-Histoquímica , Queloide/metabolismo , Masculino , Pessoa de Meia-Idade , RNA Mensageiro/genética , Pele/metabolismo , Pele/patologia , Regulação para Cima , Adulto Jovem
6.
Bioorg Med Chem Lett ; 23(9): 2560-5, 2013 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-23528296

RESUMO

The discovery and optimization of a novel series of FATP1 inhibitors are described. Through the derivatization process, arylpiperazine derivatives 5k and 12a were identified as possessing potent in vitro activity against human and mouse FATP1s as well as excellent pharmacokinetic properties. In vivo evaluation of triglyceride accumulation in the liver, white gastrocnemius muscle and soleus is also described.


Assuntos
Proteínas de Transporte de Ácido Graxo/antagonistas & inibidores , Piperazinas/química , Animais , Proteínas de Transporte de Ácido Graxo/metabolismo , Meia-Vida , Humanos , Fígado/metabolismo , Camundongos , Músculo Esquelético/metabolismo , Piperazinas/síntese química , Piperazinas/farmacocinética , Ligação Proteica , Relação Estrutura-Atividade , Triglicerídeos/metabolismo
7.
J Dermatol ; 40(5): 380-3, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23451938

RESUMO

Keloids are a proliferative fibrotic disease characterized by abnormal accumulation of extracellular matrix in the dermis. Keloid lesions lack skin plasticity due to deficiencies in elastic fiber formation in the extracellular matrix. The loss of elastic fiber is caused by excessive accumulation of chondroitin sulfate (CS), a sulfated glycosaminoglycan. However, there is no radical cure for keloids. Using a model system, we show herein that treatment of keloid tissues with chondroitinase ABC, an enzyme that specifically digests CS, improves clinical features of keloids. Keloid tissues obtained from patients were grafted on nude mice, and chondroitinase ABC was injected into the grafted keloid tissues. Chondroitinase ABC treatment significantly reduced the volume of keloid implants concomitant with recovery of elastic fiber formation. These results suggest that chondroitinase ABC injection is an effective therapy for keloid.


Assuntos
Condroitina ABC Liase/administração & dosagem , Queloide/tratamento farmacológico , Adolescente , Adulto , Idoso , Animais , Avaliação Pré-Clínica de Medicamentos , Tecido Elástico/patologia , Matriz Extracelular/efeitos dos fármacos , Feminino , Humanos , Injeções Intralesionais , Queloide/patologia , Masculino , Camundongos Endogâmicos BALB C , Camundongos Nus , Regeneração/efeitos dos fármacos
8.
PLoS One ; 7(10): e48443, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23144763

RESUMO

Plant activators are agrochemicals that activate the plant immune system, thereby enhancing disease resistance. Due to their prophylactic and durable effects on a wide spectrum of diseases, plant activators can provide synergistic crop protection when used in combination with traditional pest controls. Although plant activators have achieved great success in wet-rice farming practices in Asia, their use is still limited. To isolate novel plant activators applicable to other crops, we screened a chemical library using a method that can selectively identify immune-priming compounds. Here, we report the isolation and characterization of three diuretics, bumetanide, bendroflumethiazide and clopamide, as immune-priming compounds. These drugs upregulate the immunity-related cell death of Arabidopsis suspension-cultured cells induced with an avirulent strain of Pseudomonas syringae pv. tomato in a concentration-dependent manner. The application of these compounds to Arabidopsis plants confers disease resistance to not only the avirulent but also a virulent strain of the pathogen. Unlike salicylic acid, an endogenous phytohormone that governs disease resistance in response to biotrophic pathogens, the three diuretic compounds analyzed here do not induce PR1 or inhibit plant growth, showing potential as lead compounds in a practical application.


Assuntos
Arabidopsis/imunologia , Resistência à Doença/efeitos dos fármacos , Diuréticos/farmacologia , Imunidade Vegetal/efeitos dos fármacos , Arabidopsis/citologia , Arabidopsis/microbiologia , Proteínas de Arabidopsis/genética , Bendroflumetiazida/química , Bendroflumetiazida/farmacologia , Bumetanida/química , Bumetanida/farmacologia , Morte Celular/efeitos dos fármacos , Morte Celular/genética , Morte Celular/imunologia , Células Cultivadas , Clopamida/química , Clopamida/farmacologia , Resistência à Doença/genética , Resistência à Doença/imunologia , Diuréticos/química , Relação Dose-Resposta a Droga , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Interações Hospedeiro-Patógeno/efeitos dos fármacos , Interações Hospedeiro-Patógeno/imunologia , Estrutura Molecular , Doenças das Plantas/genética , Doenças das Plantas/imunologia , Doenças das Plantas/microbiologia , Imunidade Vegetal/genética , Pseudomonas syringae/efeitos dos fármacos , Pseudomonas syringae/imunologia , Pseudomonas syringae/fisiologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Transcrição/genética
9.
Front Plant Sci ; 3: 245, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23118736

RESUMO

Plant activators are agrochemicals that protect crops from diseases by activating the plant immune system. To isolate lead compounds for use as practical plant activators, we screened two different chemical libraries composed of various bioactive substances by using an established screening procedure that can selectively identify immune-priming compounds. We identified and characterized a group of sulfonamide compounds - sulfameter, sulfamethoxypyridazine, sulfabenzamide, and sulfachloropyridazine - among the various isolated candidate molecules. These sulfonamide compounds enhanced the avirulent Pseudomonas-induced cell death of Arabidopsis suspension cell cultures and increased disease resistance in Arabidopsis plants against both avirulent and virulent strains of the bacterium. These compounds did not prevent the growth of pathogenic bacteria in minimal liquid media at 200 µM. They also did not induce the expression of defense-related genes in Arabidopsis seedlings, at least not at 24 and 48 h after treatment, suggesting that they do not act as salicylic acid analogs. In addition, although sulfonamides are known to be folate biosynthesis inhibitors, the application of folate did not restore the potentiation effects of the sulfonamides on pathogen-induced cell death. Our data suggest that sulfonamides potentiate Arabidopsis disease resistance by their novel chemical properties.

10.
Bioorg Med Chem Lett ; 22(15): 5067-70, 2012 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-22749869

RESUMO

The discovery, optimization and structure-activity relationship of novel FATP1 inhibitors have been described. The detailed SAR studies of each moiety of the inhibitors combined with metabolite analysis led to the identification of the potent inhibitors 11p and 11q with improved blood stability.


Assuntos
Benzoxazóis/química , Proteínas de Transporte de Ácido Graxo/antagonistas & inibidores , Triazóis/química , Administração Oral , Animais , Benzoxazóis/síntese química , Benzoxazóis/farmacocinética , Avaliação Pré-Clínica de Medicamentos , Proteínas de Transporte de Ácido Graxo/metabolismo , Humanos , Injeções Intravenosas , Camundongos , Ratos , Relação Estrutura-Atividade , Triazóis/síntese química , Triazóis/farmacocinética
11.
J Biosci Bioeng ; 110(3): 351-8, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20547352

RESUMO

The chicken B cell line DT40 undergoes hypermutation of immunoglobulin variable region (IgV) genes during culture, thereby constituting an antibody (Ab) library. We previously established an in vitro Ab generation system using an engineered line DT40-SW whose hypermutation machinery can be switched on and off. Abs for various antigens (Ags) can be obtained from the DT40-SW library and the specificity of the Ag-specific clones can be stabilized by stopping hypermutation. Furthermore, the affinity of obtained monoclonal Abs (mAbs) can be improved through further mutation followed by selection, a process analogous to "affinity maturation" that occurs in vivo. Although gene conversion dominantly diversifies the IgV genes in DT40 cells, point mutation is considered to be more favorable for fine-tuning Ab properties during affinity maturation. Here, we examined whether affinity maturation occurs more efficiently when the hypermutation pattern was transformed from gene conversion into point mutation in DT40-SW cells. To this end, we disrupted the XRCC3 gene that is essential for gene conversion. It was found that hemizygous disruption of the XRCC3 gene was sufficient to increase the point mutation frequency. Since hemizygous disruption is conducted more easily, we tested whether the XRCC3 (+/-) mutant generates high-affinity Abs through affinity maturation more efficiently than the wild type. Using this affinity maturation technique, we generated an improved 4-hydroxy-3-nitrophenylacetyl-specific mAb with approximately 600-fold lower K(D) than that of the original mAb. Taken together, hemizygous disruption of the XRCC3 gene is considered to be useful for obtaining high-affinity mAbs from DT40-SW cells though affinity maturation.


Assuntos
Anticorpos Monoclonais/isolamento & purificação , Anticorpos Monoclonais/metabolismo , Galinhas/fisiologia , Mutação Puntual/genética , Engenharia de Proteínas/métodos , Animais , Anticorpos Monoclonais/genética , Linhagem Celular , Melhoramento Genético , Humanos
12.
Biochem Biophys Res Commun ; 396(2): 353-8, 2010 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-20416279

RESUMO

Chicken B cell line DT40 continuously accumulates mutations in the immunoglobulin variable region (IgV) gene by gene conversion and point mutation, both of which are mediated by activation-induced cytidine deaminase (AID), thereby producing an antibody (Ab) library that is useful for screening monoclonal Abs (mAbs) in vitro. We previously generated an engineered DT40 line named DT40-SW, whose AID expression can be reversibly switched on or off, and developed an in vitro Ab generation system using DT40-SW cells. To efficiently create an Ab library with sufficient diversity, higher hypermutation frequency is advantageous. To this end, we generated a novel cell line DT40-SWDeltaC, which conditionally expresses a C-terminus-truncated AID mutant lacking the nuclear export signal. The transcription level of the mutant AID gene in DT40-SWDeltaC cells was similar to that of the wild-type gene in DT40-SW cells. However, the protein level of the truncated AID mutant was less than that of the wild type. The mutant protein was enriched in the nuclei of DT40-SWDeltaC cells, although the protein might be highly susceptible to degradation. In DT40-SWDeltaC cells, both gene conversion and point mutation occurred in the IgV gene with over threefold higher frequency than in DT40-SW cells, suggesting that a lower level of the mutant AID protein was sufficient to increase mutation frequency. Thus, DT40-SWDeltaC cells may be useful for constructing Ab libraries for efficient screening of mAbs in vitro.


Assuntos
Anticorpos Monoclonais/genética , Linfócitos B/imunologia , Linhagem Celular , Região Variável de Imunoglobulina/genética , Biblioteca de Peptídeos , Hipermutação Somática de Imunoglobulina , Animais , Galinhas , Citidina Desaminase/genética
13.
Biochem Biophys Res Commun ; 390(4): 1221-8, 2009 Dec 25.
Artigo em Inglês | MEDLINE | ID: mdl-19879246

RESUMO

Keloid is a fibrotic disease characterized by abnormal accumulation of extracellular matrix in the dermis. The keloid matrix contains excess collagen and glycosaminoglycans (GAGs), but lacks elastic fiber. However, the roles of these matrix components in the pathogenesis of keloid are largely unknown. Here, we show that elastin and DANCE (also known as fibulin-5), a protein required for elastic fiber formation, are not deposited in the extracellular matrix of keloids, due to excess accumulation of chondoitin sulfate (CS), although the expression of elastin and DANCE is not affected. Amount of CS accumulated in the keloid legion was 6.9-fold higher than in normal skin. Fibrillin-1, a scaffold protein for elastic fiber assembly, was abnormally distributed in the keloid matrix. Addition of purified CS to keloid fibroblast culture resulted in abnormal deposition of fibrillin-1, concomitant with significantly decreased accumulation of elastin and DANCE in the extracellular matrix. We propose that CS plays a crucial role in the development of keloid lesions through inhibition of elastic fiber assembly.


Assuntos
Sulfatos de Condroitina/metabolismo , Tecido Elástico/patologia , Queloide/patologia , Dermatopatias/patologia , Adolescente , Adulto , Idoso , Criança , Tecido Elástico/metabolismo , Feminino , Humanos , Queloide/metabolismo , Masculino , Pessoa de Meia-Idade , Dermatopatias/metabolismo , Adulto Jovem
14.
J Biosci Bioeng ; 107(2): 206-9, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19217561

RESUMO

We developed a novel in vitro antibody (Ab) generation system using a hypermutating chicken B cell line (DT40-SW). We suppressed the expression of the Pax5 transcription factor by targeted disruption of the gene to increase Ab production in isolated clones and produce the desired Abs. This single genetic manipulation resulted in a significant enhancement of Ab production without significantly affecting maximum cell density.


Assuntos
Formação de Anticorpos , Fator de Transcrição PAX5/metabolismo , Animais , Sequência de Bases , Linhagem Celular , Galinhas , Primers do DNA , Fator de Transcrição PAX5/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa
15.
FEBS Lett ; 582(16): 2435-40, 2008 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-18554506

RESUMO

Very long-chain fatty acids are produced through a four-step cycle. However, the 3-hydroxyacyl-CoA dehydratase catalyzing the third step in mammals has remained unidentified. Mammals have four candidates, HACD1-4, based on sequence similarities to the recently identified yeast Phs1, although HACD3 and HACD4 share relatively weak similarity. We demonstrate that all four of these human proteins are indeed 3-hydroxyacyl-CoA dehydratases, in growth suppression experiments using a PHS1-shut off yeast strain and/or in vitro 3-hydroxypalmitoyl-CoA dehydratase assays. HACD proteins exhibit distinct tissue-expression patterns. We also establish that HACD proteins interact with the condensation enzymes ELOVL1-7, with some preferences.


Assuntos
Ácidos Graxos/biossíntese , Hidroliases/metabolismo , Acetiltransferases/metabolismo , Linhagem Celular , Retículo Endoplasmático/enzimologia , Elongases de Ácidos Graxos , Ácidos Graxos/química , Células HeLa , Humanos , RNA Mensageiro/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Distribuição Tecidual
16.
J Biol Chem ; 283(17): 11199-209, 2008 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-18272525

RESUMO

Yeast Phs1 is the 3-hydroxyacyl-CoA dehydratase that catalyzes the third reaction of the four-step cycle in the elongation of very long-chain fatty acids (VLCFAs). In yeast, the hydrophobic backbone of sphingolipids, ceramide, consists of a long-chain base and an amide-linked C26 VLCFA. Therefore, defects in VLCFA synthesis would be expected to greatly affect sphingolipid synthesis. In fact, in this study we found that reduced Phs1 levels result in significant impairment of the conversion of ceramide to inositol phosphorylceramide. Phs1 proteins are conserved among eukaryotes, constituting a novel protein family. Phs1 family members exhibit no sequence similarity to other dehydratase families, so their active site sequence and catalytic mechanism have been completely unknown. Here, by mutating 22 residues conserved among Phs1 family members, we identified six amino acid residues important in Phs1 function, two of which (Tyr-149 and Glu-156) are indispensable. We also examined the membrane topology of Phs1 using an N-glycosylation reporter assay. Our results suggest that Phs1 is a membrane-spanning protein that traverses the membrane six times and has an N terminus and C terminus facing the cytosol. The important amino acids are concentrated in or near two of the six proposed transmembrane regions. Thus, we also propose a catalytic mechanism for Phs1 that is not unlike mechanisms used by other hydratases active in lipid synthesis.


Assuntos
Membrana Celular/metabolismo , Ácidos Graxos/metabolismo , Proteínas Fúngicas/química , Hidroliases/metabolismo , Proteínas de Saccharomyces cerevisiae/fisiologia , Saccharomyces cerevisiae/enzimologia , Sequência de Aminoácidos , Citosol/metabolismo , Primers do DNA/química , Regulação Fúngica da Expressão Gênica , Hidroliases/química , Hidroliases/fisiologia , Modelos Biológicos , Modelos Químicos , Dados de Sequência Molecular , Mutação , Estrutura Terciária de Proteína , Proteínas de Saccharomyces cerevisiae/química , Esfingolipídeos/metabolismo
17.
Mol Biol Cell ; 19(5): 1922-31, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18287536

RESUMO

Biological membranes consist of lipid bilayers. The lipid compositions between the two leaflets of the plasma membrane differ, generating lipid asymmetry. Maintenance of proper lipid asymmetry is physiologically quite important, and its collapse induces several cellular responses including apoptosis and platelet coagulation. Thus, a change in lipid asymmetry must be restored to maintain "lipid asymmetry homeostasis." However, to date no lipid asymmetry-sensing proteins or any related downstream signaling pathways have been identified. We recently demonstrated that expression of the putative yeast sphingoid long-chain base transporter/translocase Rsb1 is induced when glycerophospholipid asymmetry is altered. Using mutant screening, we determined that the pH-responsive Rim101 pathway, the protein kinase Mck1, and the transcription factor Mot3 all act in lipid asymmetry signaling, and that the Rim101 pathway was activated in response to a change in lipid asymmetry. The activated transcription factor Rim101 induces Rsb1 expression via repression of another transcription repressor, Nrg1. Changes in lipid asymmetry are accompanied by cell surface exposure of negatively charged phospholipids; we speculate that the Rim101 pathway recognizes the surface charges.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Metabolismo dos Lipídeos , Proteínas de Membrana/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Membrana Celular/metabolismo , Regulação Fúngica da Expressão Gênica , Concentração de Íons de Hidrogênio , Proteínas de Membrana/genética , Modelos Biológicos , Proteínas Mutantes/isolamento & purificação , Proteínas Mutantes/metabolismo , Mutação/genética , Fosfatidiletanolaminas/metabolismo , Proteínas Repressoras , Saccharomyces cerevisiae/citologia , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/genética , Transdução de Sinais
18.
Biochem Biophys Res Commun ; 357(1): 212-7, 2007 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-17418101

RESUMO

Platelets are known to store a large amount of the bioactive lipid molecule sphingosine 1-phosphate (S1P) and to release it into the plasma in a stimuli-dependent manner. Erythrocytes can also release S1P, independently from any stimuli. We measured the S1P and sphingosine (Sph) levels in erythrocytes by HPLC and found that the contribution of erythrocyte S1P to whole blood S1P levels is actually higher than that of platelets. In vitro assays demonstrated that erythrocytes possess much weaker Sph kinase activity compared to platelets but lack the S1P-degrading activities of either S1P lyase or S1P phosphohydrolase. This combination may enable erythrocytes to maintain a high S1P content relative to Sph. The absence of both S1P-degrading enzymes has not been reported for other cell types. Thus, erythrocytes may be specialized cells for storing and supplying plasma S1P.


Assuntos
Aldeído Liases/metabolismo , Plaquetas/metabolismo , Eritrócitos/metabolismo , Lisofosfolipídeos/metabolismo , Proteínas de Membrana/metabolismo , Monoéster Fosfórico Hidrolases/metabolismo , Esfingosina/análogos & derivados , Células Cultivadas , Humanos , Esfingosina/metabolismo
19.
Immunopharmacol Immunotoxicol ; 28(3): 491-500, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16997797

RESUMO

A nasal formulation of mometasone furoate (MF) is advantageous in avoiding systemic activity characteristic of glucocorticoids when it is applied topically. To confirm antiallergic effects of this glucocorticoid formulation elaborately, we investigated whether the drug can suppress the production of IgE antibodies and related cytokines. It we showed that IgE production induced in mice immunized via intranasal route was significantly reduced when the mice were administered MF intranasally. Further, MF was effective in inhibiting production of type-2 helper T cell cytokines in vivo and in vitro. These results provide a immunopharmacological basis for clinical efficacy of this drug.


Assuntos
Formação de Anticorpos/efeitos dos fármacos , Imunoglobulina E/imunologia , Interleucina-4/biossíntese , Pregnadienodiois/farmacologia , Administração Intranasal , Animais , Antialérgicos/administração & dosagem , Antialérgicos/imunologia , Antialérgicos/farmacologia , Formação de Anticorpos/imunologia , Linhagem Celular , Hipersensibilidade a Drogas/imunologia , Hipersensibilidade a Drogas/metabolismo , Hipersensibilidade a Drogas/prevenção & controle , Imunização/métodos , Imunoglobulina E/metabolismo , Imunoglobulina G/imunologia , Imunoglobulina G/metabolismo , Injeções Subcutâneas , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Furoato de Mometasona , Nitrocompostos/administração & dosagem , Nitrocompostos/imunologia , Ovalbumina/administração & dosagem , Ovalbumina/imunologia , Pregnadienodiois/administração & dosagem , Pregnadienodiois/imunologia , Células Th2/efeitos dos fármacos , Células Th2/imunologia , Células Th2/metabolismo
20.
Biol Pharm Bull ; 29(8): 1542-6, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16880601

RESUMO

Biological membranes are composed of lipid bilayers. Major lipid components of the eukaryotic plasma membrane include glycerophospholipids, sphingolipids, and cholesterol. Lipids are irregularly distributed between the two leaflets, thus causing lipid asymmetry, or within the same leaflet, forming a lipid microdomain. Glycerophospholipids and sphingolipids both contribute to the lipid asymmetry, whereas cholesterol and sphingolipids form lipid microdomains. Maintenance of proper lipid asymmetry is required for the mechanical stability of the membrane and for vesicular transport. On the other hand, local or global changes in lipid asymmetry are important for cell cycle progression, apoptosis, and platelet coagulation. Three classes of lipid translocases, P-type ATPases, ABC transporters, and scramblases, are known to be involved in the regulation of lipid asymmetry. In this review, we describe the physiological and pathological functions of lipid asymmetry and the current knowledge of lipid translocases.


Assuntos
Membrana Celular/metabolismo , Glicerofosfolipídeos/metabolismo , Transportadores de Cassetes de Ligação de ATP/metabolismo , Adenosina Trifosfatases/metabolismo , Transporte Biológico , Membrana Celular/enzimologia , Células Eucarióticas/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...