Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 57
Filtrar
1.
Dev Growth Differ ; 60(2): 87-96, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29471585

RESUMO

During tissue development, the morphogenesis of epithelial sheets is regulated by many factors, including mechanical force, although the underlying mechanisms remain largely unknown. In the pharyngeal region of the vertebrate embryo, endodermal epithelium is reiteratively folded outward to form pharyngeal pouches, making partitions between the pharyngeal arches. Ripply3, encoding a member of the Ripply family of adaptor proteins, is required for the pouch formation posterior to the 2nd pharyngeal pouch. In this study, we found that the expression of mouse Ripply3 was specifically activated in accordance with the bending of the endodermal epithelium during the pouch formation. In Ripply3-deficient embryos, a continuous monolayer of the endodermal epithelium was not maintained posterior to the 2nd pharyngeal pouch. Corresponding to the endodermal region of the deformed epithelium, the activated form of Integrin ß1, which was localized at the basal side of the epithelial cells in the wild-type embryos, was not persistently observed in the mutants. On the other hand, cell proliferation and apoptotic cell death in the endoderm were not obviously affected by the Ripply3 deficiency. Significantly, Ripply3 expressed in cultured cells was found to be preferentially accumulated in the focal adhesions, which are Integrin-mediated adhesive contact sites transmitting mechanical force between the extracellular matrix and attached cells. Furthermore, Ripply3 promoted the maturation of focal adhesions in these cells. Thus, Ripply3 appears to have been activated to enhance the connection between the extracellular matrix and endodermal epithelial cells, as a mechanism to resist the mechanical stress generated during the bending of the epithelial sheets.


Assuntos
Região Branquial/embriologia , Endoderma/embriologia , Epitélio/embriologia , Morfogênese/genética , Proteínas Repressoras/genética , Animais , Apoptose/genética , Padronização Corporal/fisiologia , Células COS , Linhagem Celular , Proliferação de Células/genética , Chlorocebus aethiops , Adesões Focais/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Cadeias beta de Integrinas/metabolismo , Camundongos , Camundongos Knockout , Morfogênese/fisiologia , Proteínas Repressoras/biossíntese , Estresse Mecânico
2.
Mol Cell ; 39(4): 570-82, 2010 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-20797629

RESUMO

Proinflammatory cytokines activate NF-kappaB using the IkappaB kinase (IKK) complex that phosphorylates inhibitory proteins (IkappaBs) at N-terminal sites resulting in their ubiquitination and degradation in the cytoplasm. Although ultraviolet (UV) irradiation does not lead to IKK activity, it activates NF-kappaB by an unknown mechanism through IkappaBalpha degradation without N-terminal phosphorylation. Here, we describe an adaptor function of nuclear IKKbeta in UV-induced IkappaBalpha degradation. UV irradiation induces the nuclear translocation of IkappaBalpha and association with IKKbeta, which constitutively interacts with beta-TrCP through heterogeneous ribonucleoprotein-U (hnRNP-U) leading to IkappaBalpha ubiquitination and degradation. Furthermore, casein kinase 2 (CK2) and p38 associate with IKKbeta and promote IkappaBalpha degradation by phosphorylation at C-terminal sites. Thus, nuclear IKKbeta acts as an adaptor protein for IkappaBalpha degradation in UV-induced NF-kappaB activation. NF-kappaB activated by the nuclear IKKbeta adaptor protein suppresses anti-apoptotic gene expression and promotes UV-induced cell death.


Assuntos
Núcleo Celular/efeitos da radiação , Quinase I-kappa B/metabolismo , Proteínas I-kappa B/metabolismo , NF-kappa B/metabolismo , Processamento de Proteína Pós-Traducional/efeitos da radiação , Raios Ultravioleta , Transporte Ativo do Núcleo Celular , Animais , Apoptose/efeitos da radiação , Caseína Quinase II/metabolismo , Linhagem Celular , Núcleo Celular/metabolismo , Núcleo Celular/patologia , Fibroblastos/metabolismo , Fibroblastos/efeitos da radiação , Ribonucleoproteínas Nucleares Heterogêneas Grupo U/metabolismo , Humanos , Quinase I-kappa B/deficiência , Quinase I-kappa B/genética , Proteínas I-kappa B/deficiência , Proteínas I-kappa B/genética , Camundongos , Camundongos Knockout , Mutação , Inibidor de NF-kappaB alfa , NF-kappa B/genética , Fosforilação , Fatores de Tempo , Fator de Transcrição RelA/genética , Fator de Transcrição RelA/metabolismo , Transfecção , Ubiquitinação , Proteínas Contendo Repetições de beta-Transducina/genética , Proteínas Contendo Repetições de beta-Transducina/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
3.
Am J Physiol Endocrinol Metab ; 309(3): E214-23, 2015 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-26015438

RESUMO

Dipeptidyl peptidase IV (DPP-IV) expression in visceral adipose tissue is reportedly increased in obese patients, suggesting an association of DPP-IV with inflammation. In this study, first, lipopolysaccharide (LPS)- or palmitate-induced elevations of inflammatory cytokine mRNA expressions in RAW264.7 macrophages were shown to be significantly suppressed by coincubation with a DPP-IV inhibitor, anagliptin (10 µM), despite low DPP-IV expression in the RAW264.7 cells. Regarding the molecular mechanism, LPS-induced degradation of IκBα and phosphorylations of p65, JNK, and p38, as well as NF-κB and AP-1 promoter activities, were revealed to be suppressed by incubation with anagliptin, indicating suppressive effects of anagliptin on both NF-κB and AP-1 signaling pathways. Anagliptin also acted on 3T3-L1 adipocytes, weakly suppressing the inflammatory cytokine expressions induced by LPS and TNFα. When 3T3-L1 and RAW cells were cocultured and stimulated with LPS, the effects of anagliptin on the suppression of cytokine expressions in 3T3-L1 adipocytes were more marked and became evident at the 10 µM concentration. Anti-inflammatory effects of anagliptin were also observed in vivo on the elevated hepatic and adipose expressions and serum concentrations of inflammatory cytokines in association with the suppression of hepatic NF-κB transcriptional activity in LPS-infused mice. Taking these observations together, the anti-inflammatory properties of anagliptin may be beneficial in terms of preventing exacerbation of diabetes and cardiovascular events.


Assuntos
Adipócitos Brancos/efeitos dos fármacos , Anti-Inflamatórios não Esteroides/farmacologia , Inibidores da Dipeptidil Peptidase IV/farmacologia , Fígado/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , NF-kappa B/antagonistas & inibidores , Pirimidinas/farmacologia , Células 3T3-L1 , Adipócitos Brancos/imunologia , Adipócitos Brancos/metabolismo , Animais , Anti-Inflamatórios não Esteroides/uso terapêutico , Linhagem Celular Transformada , Técnicas de Cocultura , Citocinas/agonistas , Citocinas/antagonistas & inibidores , Citocinas/genética , Citocinas/metabolismo , Dipeptidil Peptidase 4/química , Dipeptidil Peptidase 4/genética , Dipeptidil Peptidase 4/metabolismo , Inibidores da Dipeptidil Peptidase IV/uso terapêutico , Regulação da Expressão Gênica/efeitos dos fármacos , Genes Reporter/efeitos dos fármacos , Fígado/imunologia , Fígado/metabolismo , Macrófagos/imunologia , Macrófagos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , NF-kappa B/agonistas , NF-kappa B/genética , NF-kappa B/metabolismo , Fosforilação/efeitos dos fármacos , Processamento de Proteína Pós-Traducional/efeitos dos fármacos , Pirimidinas/uso terapêutico , Elementos de Resposta/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Síndrome de Resposta Inflamatória Sistêmica/sangue , Síndrome de Resposta Inflamatória Sistêmica/imunologia , Síndrome de Resposta Inflamatória Sistêmica/metabolismo , Síndrome de Resposta Inflamatória Sistêmica/prevenção & controle
4.
Mediators Inflamm ; 2015: 125380, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26170532

RESUMO

Nonalcoholic steatohepatitis (NASH) is a disorder characterized by hepatic lipid accumulation followed by the inflammation-induced death of hepatocytes and fibrosis. In this process, oxidative stress contributes to the induction of several inflammatory cytokines including TNF-α andIL-1ß in macrophages, while, in hepatocytes, NF-κB reportedly induces the expressions of cell survival genes for protection from apoptosis. Recently, it was reported that the new ubiquitin ligase complex termed linear ubiquitin chain assembly complex (LUBAC), composed of SHARPIN (SHANK-associated RH domain-interacting protein), HOIL-1L (longer isoform of heme-oxidized iron-regulatory protein 2 ubiquitin ligase-1), and HOIP (HOIL-1L interacting protein), forms linear ubiquitin on NF-κB essential modulator (NEMO) and thereby induces NF-κB pathway activation. In this study, we demonstrated the formation of LUBAC to be impaired in the livers of NASH rodent models produced by methionine and choline deficient (MCD) diet feeding, first by either gel filtration or Blue Native-PAGE, with subsequent confirmation by western blotting. The reduction of LUBAC is likely to be attributable to markedly reduced expression of SHARPIN, one of its components. Thus, impaired LUBAC formation, which would result in insufficient NF-κB activation, may be one of the molecular mechanisms underlying the enhanced apoptotic response of hepatocytes in MCD diet-induced NASH livers.


Assuntos
Deficiência de Colina/metabolismo , Fígado/metabolismo , Metionina/deficiência , Hepatopatia Gordurosa não Alcoólica/metabolismo , Ubiquitina/metabolismo , Animais , Proteínas de Transporte/análise , Proteínas de Transporte/genética , Peptídeos e Proteínas de Sinalização Intracelular , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Palmitatos/farmacologia , Ubiquitina-Proteína Ligases/análise
5.
J Biol Chem ; 288(28): 20692-701, 2013 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-23720771

RESUMO

Pin1 and Par14 are parvulin-type peptidyl-prolyl cis/trans isomerases. Although numerous proteins have been identified as Pin1 substrates, the target proteins of Par14 remain largely unknown. Par14 expression levels are increased in the livers and embryonic fibroblasts of Pin1 KO mice, suggesting a compensatory relationship between the functions of Pin1 and Par14. In this study, the association of Par14 with insulin receptor substrate 1 (IRS-1) was demonstrated in HepG2 cells overexpressing both as well as endogenously in the mouse liver. The analysis using deletion-mutated Par14 and IRS-1 constructs revealed the N-terminal portion containing the basic domain of Par14 and the two relatively C-terminal portions of IRS-1 to be involved in these associations, in contrast to the WW domain of Pin1 and the SAIN domain of IRS-1. Par14 overexpression in HepG2 markedly enhanced insulin-induced IRS-1 phosphorylation and its downstream events, PI3K binding with IRS-1 and Akt phosphorylation. In contrast, treating HepG2 cells with Par14 siRNA suppressed these events. In addition, overexpression of Par14 in the insulin-resistant ob/ob mouse liver by adenoviral transfer significantly improved hyperglycemia with normalization of hepatic PEPCK and G6Pase mRNA levels, and gene suppression of Par14 using shRNA adenovirus significantly exacerbated the glucose intolerance in Pin1 KO mice. Therefore, although Pin1 and Par14 associate with different portions of IRS-1, the prolyl cis/trans isomerization in multiple sites of IRS-1 by these isomerases appears to be critical for efficient insulin receptor-induced IRS-1 phosphorylation. This process is likely to be one of the major mechanisms regulating insulin sensitivity and also constitutes a potential therapeutic target for novel insulin-sensitizing agents.


Assuntos
Proteínas Substratos do Receptor de Insulina/metabolismo , Insulina/farmacologia , Peptidilprolil Isomerase/metabolismo , Animais , Sítios de Ligação/genética , Intolerância à Glucose/genética , Células HEK293 , Células Hep G2 , Humanos , Hiperglicemia/genética , Hiperglicemia/terapia , Hipoglicemiantes/farmacologia , Immunoblotting , Proteínas Substratos do Receptor de Insulina/genética , Fígado/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Obesos , Mutação , Peptidilprolil Isomerase de Interação com NIMA , Obesidade/sangue , Obesidade/genética , Peptidilprolil Isomerase/genética , Fosfatidilinositol 3-Quinases/metabolismo , Fosforilação/efeitos dos fármacos , Ligação Proteica , Proteínas Proto-Oncogênicas c-akt/metabolismo , Interferência de RNA
6.
Trop Med Health ; 52(1): 9, 2024 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-38212868

RESUMO

BACKGROUND: Weak acids, such as acetic acid, show virucidal effects against viruses, and disinfectants are considered effective virucidal agents possibly because of their low pH, depending on the proton concentration. This study aimed to evaluate the efficacy of different weak acids (acetic, oxalic, and citric acids) and eligible vinegars under different pH conditions by comparing their inactivation efficacies against enveloped and non-enveloped viruses. METHODS: Acetic, oxalic, and citric acids were adjusted to pH values of 2, 4 and 6, respectively. They were also diluted from 1 M to 0.001 M with distilled water. Enveloped influenza A virus (FulV) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and non-enveloped feline calicivirus (FCV) were treated with adjusted weak acids for up to 30 min. These viruses were also reacted with white distilled vinegar (WDV) and grain-flavored distilled vinegar (GV) for up to 30 min. Infectious viral titers after the reactions were expressed as plaque-forming units per mL. RESULTS: Acetic acid showed virucidal effects against FulV at pH 4, whereas citric and oxalic acids did not. Acetic and citric acids inactivated SARS-CoV-2 at pH 2, whereas oxalic acid did not. All acids showed virucidal effects against FVC at pH 2; however, not at pH 4. The virucidal effects of the serially diluted weak acids were also reflected in the pH-dependent results. WDV and GV significantly reduced FulV titers after 1 min. SARS-CoV-2 was also susceptible to the virucidal effects of WDV and GV; however, the incubation period was extended to 30 min. In contrast, WDV and GV did not significantly inactivate FCV. CONCLUSIONS: The inactivation efficacy of weak acids is different even under the same pH conditions, suggesting that the virucidal effect of weak acids is not simply determined by pH, but that additional factors may also influence these effects. Moreover, eligible vinegars, the main component of which is acetic acid, may be potential sanitizers for some enveloped viruses, such as FulV, in the domestic environment.

7.
J Biol Chem ; 287(53): 44526-35, 2012 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-23112047

RESUMO

Nonalcoholic steatohepatitis (NASH) is a disorder characterized by simultaneous fat accumulation and chronic inflammation in the liver. In this study, Pin1 expression was revealed to be markedly increased in the livers of mice with methionine choline-deficient (MCD) diet-induced NASH, a rodent model of NASH. In addition, Pin1 KO mice were highly resistant to MCD-induced NASH, based on a series of data showing simultaneous fat accumulation, chronic inflammation, and fibrosis in the liver. In terms of Pin1-induced fat accumulation, it was revealed that the expression levels of peroxisome proliferator-activated receptor α and its target genes were higher in the livers of Pin1 KO mice than in controls. Thus, resistance of Pin1 KO mice to hepatic steatosis is partially attributable to the lack of Pin1-induced down-regulation of peroxisome proliferator-activated receptor α, although multiple other mechanisms are apparently involved. Another mechanism involves the enhancing effect of hematopoietic Pin1 on the expressions of inflammatory cytokines such as tumor necrosis factor and monocyte chemoattractant protein 1 through NF-κB activation, eventually leading to hepatic fibrosis. Finally, to distinguish the roles of hematopoietic or nonhematopoietic Pin1 in NASH development, mice lacking Pin1 in either nonhematopoietic or hematopoietic cells were produced by bone marrow transplantation between wild-type and Pin1 KO mice. The mice having nonhematopoietic Pin1 exhibited fat accumulation without liver fibrosis on the MCD diet. Thus, hepatic Pin1 appears to be directly involved in the fat accumulation in hepatocytes, whereas Pin1 in hematopoietic cells contributes to inflammation and fibrosis. In summary, this is the first study to demonstrate that Pin1 plays critical roles in NASH development. This report also raises the possibility that hepatic Pin1 inhibition to the appropriate level might provide a novel therapeutic strategy for NASH.


Assuntos
Fígado Gorduroso/enzimologia , Peptidilprolil Isomerase/metabolismo , Animais , Modelos Animais de Doenças , Fígado Gorduroso/genética , Fígado Gorduroso/patologia , Feminino , Humanos , Fígado/enzimologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Peptidilprolil Isomerase de Interação com NIMA , Hepatopatia Gordurosa não Alcoólica , Peptidilprolil Isomerase/genética
8.
Biochem Biophys Res Commun ; 434(2): 197-202, 2013 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-23523797

RESUMO

The dynamic process of adipose differentiation involves stepwise expressions of transcription factors and proteins specific to the mature fat cell phenotype. In this study, it was revealed that expression levels of IntS6 and IntS11, subunits of the Integrator complex, were increased in 3T3-L1 cells in the period when the cells reached confluence and differentiated into adipocytes, while being reduced to basal levels after the completion of differentiation. Suppression of IntS6 or IntS11 expression using siRNAs in 3T3-L1 preadipocytes markedly inhibited differentiation into mature adipocytes, based on morphological findings as well as mRNA analysis of adipocyte-specific genes such as Glut4, perilipin and Fabp4. Although Pparγ2 protein expression was suppressed in IntS6 or IntS11-siRNA treated cells, adenoviral forced expression of Pparγ2 failed to restore the capacity for differentiation into mature adipocytes. Taken together, these findings demonstrate that increased expression of Integrator complex subunits is an indispensable event in adipose differentiation. Although further study is necessary to elucidate the underlying mechanism, the processing of U1, U2 small nuclear RNAs may be involved in cell differentiation steps.


Assuntos
Adipócitos/citologia , Adipogenia , RNA Helicases DEAD-box/metabolismo , Complexos Multiproteicos/metabolismo , Células 3T3-L1 , Adenoviridae/metabolismo , Adipócitos/metabolismo , Animais , Western Blotting , RNA Helicases DEAD-box/genética , Proteínas de Ligação a Ácido Graxo/genética , Proteínas de Ligação a Ácido Graxo/metabolismo , Fibroblastos/citologia , Fibroblastos/metabolismo , Regulação da Expressão Gênica , Transportador de Glucose Tipo 4/genética , Transportador de Glucose Tipo 4/metabolismo , Camundongos , Complexos Multiproteicos/genética , PPAR gama/genética , PPAR gama/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Proteínas de Ligação a RNA , Fatores de Tempo , Transfecção , Proteínas Supressoras de Tumor
9.
Nutrients ; 15(2)2023 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-36678153

RESUMO

Salt and carbohydrates, two causes of elevated blood glucose, are essential components for survival; however, excessive intake of either is a known health risk. In a previous study, we reported the usefulness of pasta prepared from yellow pea (YPP) as a functional staple food that is beneficial for blood sugar control. In this study, we investigated the usefulness of YPP in reducing health risks by examining its effects on saltiness, postprandial satisfaction, and second meal. The results showed that YPP tasted saltier than conventional pasta made from semolina wheat when prepared with a 0.75% salt concentration. In addition, we examined blood glucose levels, insulin secretion, and postprandial hunger over a longer period than in previous studies. We observed that when the same amount of YPP and wheat pasta were eaten, the elevation in blood glucose and insulin secretion was lower after YPP consumption while maintaining a similar level of satiety. Furthermore, YPP was also observed to be able to suppress elevated insulin levels at the second meal.


Assuntos
Glicemia , Pisum sativum , Estudos Cross-Over , Fome , Insulina , Período Pós-Prandial , Saciação , Cloreto de Sódio na Dieta , Triticum , Humanos
10.
PLoS One ; 18(2): e0276578, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36753524

RESUMO

Effective measures are needed to prevent the spread and infectivity of SARS-CoV-2 that causes COVID-19. Chemical inactivation may help to prevent the spread and transmission of this and other viruses. Hence, we tested the SARS-CoV-2 antiviral activity of acetic acid, the main component of vinegar, in vitro. Inactivation and binding assays suggest that acetic acid is virucidal. We found that 6% acetic acid, a concentration typically found in white distilled vinegar, effectively inactivated SARS-CoV-2 after 15-min incubation with a complete loss of replication of competent virus as measured by TCID50. Transmission electron microscopy further demonstrated that 6% acetic acid disrupts SARS-CoV-2 virion structure. In addition, 6% acetic acid significantly inhibits and disrupts the binding of SARS-CoV-2 spike protein binding to ACE2, the primary SARS-CoV-2 cell receptor, after contact with spike protein for 5, 10, 30 and 60 minutes incubation. Taken together, our findings demonstrate that acetic acid possesses inactivating activity against SARS-CoV-2 and may represent a safe alternative to commonly used chemical disinfectants to effectively control the spread of SARS-CoV-2.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , SARS-CoV-2/fisiologia , Ácido Acético/farmacologia , Enzima de Conversão de Angiotensina 2/química , Glicoproteína da Espícula de Coronavírus/química
11.
J Biol Chem ; 286(23): 20812-22, 2011 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-21454638

RESUMO

Peptidyl-prolyl cis/trans isomerase NIMA-interacting 1 (Pin1) is a unique enzyme that associates with the pSer/Thr-Pro motif and catalyzes cis-trans isomerization. We identified Pin1 in the immunoprecipitates of overexpressed IRS-1 with myc and FLAG tags in mouse livers and confirmed the association between IRS-1 and Pin1 by not only overexpression experiments but also endogenously in the mouse liver. The analysis using deletion- and point-mutated Pin1 and IRS-1 constructs revealed the WW domain located in the N terminus of Pin1 and Ser-434 in the SAIN (Shc and IRS-1 NPXY binding) domain of IRS-1 to be involved in their association. Subsequently, we investigated the role of Pin1 in IRS-1 mediation of insulin signaling. The overexpression of Pin1 in HepG2 cells markedly enhanced insulin-induced IRS-1 phosphorylation and its downstream events: phosphatidylinositol 3-kinase binding with IRS-1 and Akt phosphorylation. In contrast, the treatment of HepG2 cells with Pin1 siRNA or the Pin1 inhibitor Juglone suppressed these events. In good agreement with these in vitro data, Pin1 knock-out mice exhibited impaired insulin signaling with glucose intolerance, whereas adenoviral gene transfer of Pin1 into the ob/ob mouse liver mostly normalized insulin signaling and restored glucose tolerance. In addition, it was also demonstrated that Pin1 plays a critical role in adipose differentiation, making Pin1 knock-out mice resistant to diet-induced obesity. Importantly, Pin1 expression was shown to be up-regulated in accordance with nutrient conditions such as food intake or a high-fat diet. Taken together, these observations indicate that Pin1 binds to IRS-1 and thereby markedly enhances insulin action, essential for adipogenesis.


Assuntos
Adipogenia/fisiologia , Proteínas Substratos do Receptor de Insulina/metabolismo , Insulina/metabolismo , Fígado/metabolismo , Peptidilprolil Isomerase/metabolismo , Animais , Intolerância à Glucose/genética , Intolerância à Glucose/metabolismo , Células Hep G2 , Humanos , Proteínas Substratos do Receptor de Insulina/genética , Camundongos , Camundongos Knockout , Camundongos Obesos , Peptidilprolil Isomerase de Interação com NIMA , Peptidilprolil Isomerase/genética , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Fosforilação/fisiologia , Ligação Proteica/fisiologia , Estrutura Terciária de Proteína , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/fisiologia
12.
Am J Physiol Endocrinol Metab ; 302(3): E286-96, 2012 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-22045314

RESUMO

Macrophages are integrated into adipose tissues and interact with adipocytes in obese subjects, thereby exacerbating adipose insulin resistance. This study aimed to elucidate the molecular mechanism underlying the insulin-sensitizing effect of the angiotensin II receptor blocker (ARB) valsartan, as demonstrated in clinical studies. Insulin signaling, i.e., insulin receptor substrate-1 and Akt phosphorylations, in 3T3-L1 adipocytes was impaired markedly by treatment with tumor necrosis factor-α (TNFα) or in the culture medium of lipopolysaccharide (LPS)-stimulated RAW 264.7 murine macrophages, and valsartan had no effects on these impairments. However, in contrast, when cocultured with RAW 264.7 cells using a transwell system, the LPS-induced insulin signaling impairment in 3T3-L1 adipocytes showed almost complete normalization with coaddition of valsartan. Furthermore, valsartan strongly suppressed LPS-induced productions of cytokines such as interleukin (IL)-1ß, IL-6, and TNFα with nuclear factor-κB activation and c-Jun NH(2)-terminal kinase phosphorylation in RAW 264.7 and primary murine macrophages. Very interestingly, this effect of valsartan was also observed in THP-1 cells treated with angiotensin II type 1 (AT1) siRNA or a peroxisome proliferator-activated receptor-γ (PPARγ) antagonist as well as macrophages from AT1a receptor-knockout mice. We conclude that valsartan suppresses the inflammatory response of macrophages, albeit not via PPARγ or the AT1a receptor. This suppression appears to secondarily improve adipose insulin resistance.


Assuntos
Adipócitos Brancos/efeitos dos fármacos , Anti-Inflamatórios não Esteroides/farmacologia , Resistência à Insulina , Ativação de Macrófagos/efeitos dos fármacos , PPAR gama/metabolismo , Receptor Tipo 1 de Angiotensina/metabolismo , Tetrazóis/farmacologia , Valina/análogos & derivados , Células 3T3-L1 , Adipócitos Brancos/imunologia , Adipócitos Brancos/metabolismo , Bloqueadores do Receptor Tipo 1 de Angiotensina II/farmacologia , Animais , Linhagem Celular , Células Cultivadas , Técnicas de Cocultura , Humanos , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Macrófagos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , PPAR gama/antagonistas & inibidores , Interferência de RNA , RNA Interferente Pequeno , Receptor Tipo 1 de Angiotensina/química , Receptor Tipo 1 de Angiotensina/genética , Valina/farmacologia , Valsartana
13.
Dig Dis Sci ; 57(10): 2555-61, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22610882

RESUMO

BACKGROUND AND AIMS: Endotoxin/lipopolysaccharide (LPS) alters gastrointestinal functions. However, little is known as to whether LPS could change gastric antral contractility in freely moving conscious animals. We tried to clarify this problem and the associated mechanisms. METHODS: In this study, we recorded intraluminal gastric pressure waves in freely moving conscious rats by manometric catheter located in the antrum. Area under the manometric trace was evaluated as motor index (MI). RESULTS: Intraperitoneal injection of LPS at doses of 0.2 mg/kg or more significantly inhibited MI. The inhibition started immediately after the administration of LPS and lasted over 1 h. Intraperitoneal injection of IL-1ß potently decreased MI while neither IL-6 nor TNF-α inhibited gastric motility, suggesting IL-1ß specifically reduced gastric motility. Next, we examined the hypothesis that endogenous IL-1 mediates the LPS-induced inhibition of gastric motility. To address the speculation, an IL-1 receptor antagonist (IL-1Ra) was used to block IL-1 signaling. Pretreatment with IL-1Ra at a dose of 20 mg/kg significantly blocked the inhibition of gastric contractility by LPS at a dose of 0.2 mg/kg. CONCLUSIONS: These results suggest for the first time that LPS or IL-1ß is capable of inhibiting gastric motility in conscious rats and that endogenously released IL-1 may mediate the LPS-evoked inhibition of gastric antral motility. This evidence also led us to speculate that IL-1Ra may be a therapeutic tool for patients with disturbed gastrointestinal functions under septic conditions.


Assuntos
Motilidade Gastrointestinal/efeitos dos fármacos , Lipopolissacarídeos/toxicidade , Receptores de Interleucina-1/antagonistas & inibidores , Animais , Estado de Consciência , Relação Dose-Resposta a Droga , Proteína Antagonista do Receptor de Interleucina 1/farmacologia , Interleucina-1/farmacologia , Interleucina-1beta/farmacologia , Lipopolissacarídeos/administração & dosagem , Masculino , Ratos , Ratos Sprague-Dawley , Fator de Necrose Tumoral alfa/farmacologia
14.
Am J Physiol Cell Physiol ; 300(5): C1047-54, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21270293

RESUMO

Glucose transporter 1 (GLUT1) is widely distributed throughout various tissues and contributes to insulin-independent basal glucose uptake. Using a split-ubiquitin membrane yeast two-hybrid system, we newly identified 4F2 heavy chain (4F2hc) as a membrane protein interacting with GLUT1. Though 4F2hc reportedly forms heterodimeric complexes between amino acid transporters, such as LAT1 and LAT2, and regulates amino acid uptake, we investigated the effects of 4F2hc on GLUT1 expression and the associated glucose uptake. First, FLAG-tagged 4F2hc and hemagglutinin-tagged GLUT1 were overexpressed in human embryonic kidney 293 cells and their association was confirmed by coimmunoprecipitation. The green fluorescent protein-tagged 4F2hc and DsRed-tagged GLUT1 showed significant, but incomplete, colocalization at the plasma membrane. In addition, an endogenous association between GLUT1 and 4F2hc was demonstrated using mouse brain tissue and HeLa cells. Interestingly, overexpression of 4F2hc increased the amount of GLUT1 protein in HeLa and HepG2 cells with increased glucose uptake. In contrast, small interfering RNA (siRNA)-mediated 4F2hc gene suppression markedly reduced GLUT1 protein in both cell types, with reduced glucose uptake. While GLUT1 mRNA levels were not affected by overexpression or gene silencing of 4F2hc, GLUT1 degradation after the addition of cycloheximide was significantly suppressed by 4F2hc overexpression and increased by 4F2hc siRNA treatment. Taken together, these observations indicate that 4F2hc is likely to be involved in GLUT1 stabilization and to contribute to the regulation of not only amino acid but also glucose metabolism.


Assuntos
Cadeia Pesada da Proteína-1 Reguladora de Fusão/metabolismo , Transportador de Glucose Tipo 1/metabolismo , Animais , Transporte Biológico/efeitos dos fármacos , Transporte Biológico/fisiologia , Cicloeximida/farmacologia , Células HEK293 , Células HeLa , Humanos , Masculino , Camundongos , Inibidores da Síntese de Proteínas/farmacologia , RNA Interferente Pequeno/farmacologia , Técnicas do Sistema de Duplo-Híbrido
15.
J Biol Chem ; 285(43): 33018-33027, 2010 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-20675384

RESUMO

Pin1 is a unique regulator, which catalyzes the conversion of a specific phospho-Ser/Thr-Pro-containing motif in target proteins. Herein, we identified CRTC2 as a Pin1-binding protein by overexpressing Pin1 with Myc and FLAG tags in mouse livers and subsequent purification of the complex containing Pin1. The association between Pin1 and CRTC2 was observed not only in overexpression experiments but also endogenously in the mouse liver. Interestingly, Ser(136) in the nuclear localization signal of CRTC2 was shown to be involved in the association with Pin1. Pin1 overexpression in HepG2 cells attenuated forskolin-induced nuclear localization of CRTC2 and cAMP-responsive element (CRE) transcriptional activity, whereas gene knockdown of Pin1 by siRNA enhanced both. Pin1 also associated with CRTC1, leading to their cytosol localization, essentially similar to the action of CRTC2. Furthermore, it was shown that CRTC2 associated with Pin1 did not bind to CREB. Taken together, these observations indicate the association of Pin1 with CRTC2 to decrease the nuclear CBP·CRTC·CREB complex. Indeed, adenoviral gene transfer of Pin1 into diabetic mice improved hyperglycemia in conjunction with normalizing phosphoenolpyruvate carboxykinase mRNA expression levels, which is regulated by CRE transcriptional activity. In conclusion, Pin1 regulates CRE transcriptional activity, by associating with CRTC1 or CRTC2.


Assuntos
Núcleo Celular/metabolismo , AMP Cíclico/metabolismo , Sinais de Localização Nuclear/metabolismo , Peptidilprolil Isomerase/metabolismo , Transativadores/metabolismo , Fatores de Transcrição/metabolismo , Transcrição Gênica/fisiologia , Transporte Ativo do Núcleo Celular/efeitos dos fármacos , Transporte Ativo do Núcleo Celular/fisiologia , Animais , Proteína de Ligação a CREB/genética , Proteína de Ligação a CREB/metabolismo , Núcleo Celular/genética , Colforsina/farmacologia , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/genética , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Citosol/metabolismo , Técnicas de Silenciamento de Genes , Células Hep G2 , Humanos , Fígado/metabolismo , Camundongos , Peptidilprolil Isomerase de Interação com NIMA , Sinais de Localização Nuclear/genética , Peptidilprolil Isomerase/genética , Transativadores/genética , Fatores de Transcrição/genética , Transcrição Gênica/efeitos dos fármacos
16.
Circ J ; 75(4): 791-9, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21427500

RESUMO

BACKGROUND: It is not yet clear whether glycemic control affects the clinical outcome of percutaneous coronary intervention (PCI) in diabetic patients. METHODS AND RESULTS: This study compared the effects of glycemic control on the clinical outcome in 2 groups of patients with diabetes mellitus (DM) who underwent PCI: a poor-glycemic-control group, who showed greater than 6.9% HbA(1c) at the time of PCI (Pre-HbA(1c)) (`≥6.9 group', n=334 patients) and a good-glycemic-control group, who showed less than <6.9% at Pre-HbA(1c) (`<6.9 group', n=212 patients). The patients in the ≥6.9 group were further divided into 2 groups for further comparisons: a `DM control group' and a `Poor control group'. At follow-up (300 days), the incidence of major adverse cardiac event (MACE) was significantly (P<0.05) lower in the <6.9 group (18.4% vs. 26.2%). However, there was no difference in MACE between the DM control group and the Poor control group. In a multivariate analysis, there was no relationship between the incidence of MACE and Pre-HbA(1c), Pre-HbA(1c)≥6.9% or the HbA(1c) difference (Pre-HbA(1c)-HbA(1c) at follow-up). CONCLUSIONS: Clinical outcomes in the <6.9 group were superior to those in the ≥6.9 group as pre-PCI glycemic control affected the baseline characteristics. The results suggested that glycemic control started at PCI was not associated with an improvement in the clinical outcome at follow-up.


Assuntos
Angioplastia Coronária com Balão , Glicemia , Angiopatias Diabéticas/terapia , Índice Glicêmico , Idoso , Angiopatias Diabéticas/sangue , Feminino , Seguimentos , Hemoglobinas Glicadas/análise , Hemoglobinas Glicadas/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade
17.
J Oleo Sci ; 70(3): 417-430, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33658470

RESUMO

Ceramide plays an important role in maintaining the skin barrier function. Aging and atopic dermatitis are known to reduce the levels of ceramide. Application of exogenous ceramide to the skin can restore the barrier function. In recent years, the effect of oral intake of ceramide has been demonstrated to improve the skin barrier function, and it has been marketed as a food supplement. Therefore, it is important to provide information on the safety of unintentional overdose of ceramide. This randomized, double-blind, placebo-controlled study was conducted in 30 healthy adults, aged between 20 and 60 years of age (both female and male). The subjects consumed either dietary supplement, comprising 1197 mg of acetic acid bacteria containing 9.06 mg of ceramide, or placebo for four consecutive weeks. Safety was evaluated based on physical measurements, blood test, urinalysis, adverse events, and side effects. The results showed several significant differences in physical measures and blood tests between the two groups. However, these differences were considered to be unrelated to the intake of the ceramide-containing acetic acid bacteria or placebo. Thus, no adverse effects or clinically concerning changes in physical, blood, and urine parameters were observed due to the excessive intake of the ceramide-containing acetic acid bacteria in the present study.TRIAL REGISTRATION: UMIN000035481.


Assuntos
Ácido Acético , Bactérias , Ceramidas/administração & dosagem , Suplementos Nutricionais , Administração Oral , Adulto , Ceramidas/efeitos adversos , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Segurança , Fenômenos Fisiológicos da Pele , Fatores de Tempo , Adulto Jovem
18.
Clin Exp Hypertens ; 32(1): 21-8, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20144069

RESUMO

The study aim was to examine the effect of combination therapy comprising angiotensin receptor blocker plus calcium antagonist on post-treatment plasma adiponectin levels compared to pretreatment levels. There was a significant gender difference in the relationship between preadiponectin level and age. In the search for contributing factors for treatment-based changes in adiponectin levels, these effects of gender and age were considered in statistical analysis. The adiponectin level in the combination therapy group was further increased compared to that in each of the monotherapy groups, despite there being no significant difference in antihypertensive effect, indicating that the combined medication provided an effect beyond that of lowering blood pressure.


Assuntos
Bloqueadores do Receptor Tipo 1 de Angiotensina II/administração & dosagem , Bloqueadores dos Canais de Cálcio/administração & dosagem , Hipertensão/sangue , Hipertensão/tratamento farmacológico , Adiponectina/sangue , Fatores Etários , Idoso , Ácido Azetidinocarboxílico/administração & dosagem , Ácido Azetidinocarboxílico/análogos & derivados , Benzimidazóis/administração & dosagem , Benzoatos/administração & dosagem , Estudos de Coortes , Di-Hidropiridinas/administração & dosagem , Quimioterapia Combinada , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Caracteres Sexuais , Telmisartan
19.
J Oleo Sci ; 69(11): 1497-1508, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-33055441

RESUMO

The barrier function of the skin protects it from external stresses to which it is constantly exposed, such as dryness, ultraviolet rays, and chemicals. Lipids, in particular a type of sphingolipid known as ceramides, play a central role in the barrier function of the skin by preventing dryness. The number of ceramides in the skin is known to decrease with age, which has led to the development of a large number of anti-aging cosmetic products that contain ceramides. Recently, it has become evident that oral intake of ceramides can also improve the quality of the skin. To elucidate the effects of oral ceramide intake on skin moisture content, we conducted a randomized, double-blinded, placebo-controlled parallel comparative study in which males and females between 20 and 60 years of age who were worried about dry skin ingested a food with acetic acid bacteria containing 0.8 mg of dihydroceramide or a placebo for 12 weeks. Concurrently, we investigated the safety of continuous ingestion of the ceramide-containing food over 12 weeks. Oral intake of ceramide over the 12 weeks significantly improved stratum corneum hydration, i.e. the moisture content of the skin, and did not result in harmful effects in any of the participants.


Assuntos
Acetobacter , Água Corporal/metabolismo , Ceramidas/administração & dosagem , Epiderme/metabolismo , Estado de Hidratação do Organismo/efeitos dos fármacos , Pele/metabolismo , Administração Oral , Adulto , Ceramidas/farmacologia , Suplementos Nutricionais , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Envelhecimento da Pele/efeitos dos fármacos , Adulto Jovem
20.
Biochem Biophys Res Commun ; 382(2): 348-52, 2009 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-19281795

RESUMO

Lipin-1 is a multifunctional metabolic regulator, involving in triacylglycerol and bioactive glycerolipids synthesis as an enzyme, transcriptional regulation as a coactivator, and adipogenesis. In obesity, adipose lipin-1 expression is decreased. Although lipin-1 is implicated in the pathogenesis of obesity, the mechanism is still not clear. Since TNF-alpha is deeply involved in the pathogenesis of obesity, insulin resistance, and diabetes, here we investigated the role of TNF-alpha on lipin-1 expression in adipocytes. Quantitative PCR studies showed that TNF-alpha suppressed both lipin-1A and -1B isoform expression in time- and dose-dependent manners in mature 3T3-L1 adpocytes. A Jak2 inhibitor, AG490, reversed the suppressive effect of TNF-alpha on both lipin-1A and -1B. In contrast, NF-kappaB, MAPKs, ceramide, and beta-catenin pathway tested were not involved in the mechanism. These results suggest that TNF-alpha could be involved in obesity-induced lipin-1 suppression in adipocytes and Jak2 may play an important role in the mechanism.


Assuntos
Janus Quinase 2/antagonistas & inibidores , Proteínas Nucleares/biossíntese , Obesidade/metabolismo , Fator de Necrose Tumoral alfa/fisiologia , Células 3T3-L1 , Animais , Camundongos , Fosfatidato Fosfatase , Inibidores de Proteínas Quinases/farmacologia , RNA Mensageiro/biossíntese , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Fator de Necrose Tumoral alfa/farmacologia , Tirfostinas/farmacologia
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa