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1.
Cytotherapy ; 25(11): 1229-1235, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37486281

RESUMO

BACKGROUND AIMS: With the aim of strengthening the scientific evidence of immune-cell therapy for cancer and further examining its safety, in October 2015, our hospital jointly established the Cancer Immune-Cell Therapy Evaluation Group (CITEG) with 39 medical facilities nationwide. METHODS: Medical information, such as patients' background characteristics, clinical efficacy and therapeutic cell types obtained from each facility, has been accumulated, analyzed and evaluated by CITEG. In this prospective study, we analyzed the adverse events associated with immune-cell therapy until the end of September 2022, and we presented our interim safety evaluation. RESULTS: A total of 3839 patients with malignant tumor were treated with immune-cell therapy, with a median age of 64 years (range, 13-97 years) and a male-to-female ratio of 1:1.08 (1846:1993). Most patients' performance status was 0 or 1 (86.8%) at the first visit, and 3234 cases (84.2%) were advanced or recurrent cases, which accounted for the majority. The total number of administrations reported in CITEG was 31890, of which 960 (3.0%) showed adverse events. The numbers of adverse events caused by treatment were 363 (1.8%) of 19661 administrations of αßT cell therapy, 9 of 845 administrations of γδT-cell therapy (1.1%) and 10 of 626 administrations of natural killer cell therapy (1.6%). The number of adverse events caused by dendritic cell (DC) vaccine therapy was 578 of 10748 administrations (5.4%), which was significantly larger than those for other treatments. Multivariate analysis revealed that αßT cell therapy had a significantly greater risk of adverse events at performance status 1 or higher, and patients younger than 64 years, women or adjuvant immune-cell therapy had a greater risk of adverse events in DC vaccine therapy. Injection-site reactions were the most frequently reported adverse events, with 449 events, the majority of which were associated with DC vaccine therapy. Among all other adverse events, fever (228 events), fatigue (141 events) and itching (131 events) were frequently reported. In contrast, three patients had adverse events (fever, abdominal pain and interstitial pneumonia) that required hospitalization, although they were weakly related to this therapy; rather, it was considered to be the effect of treatment for the primary disease. CONCLUSIONS: Immune-cell therapy for cancer was considered to be a safe treatment without serious adverse events.


Assuntos
Neoplasias , Humanos , Masculino , Feminino , Adolescente , Adulto Jovem , Adulto , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Estudos Prospectivos , Neoplasias/terapia , Imunoterapia Adotiva , Resultado do Tratamento
2.
Protein Pept Lett ; 29(12): 1082-1087, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36173053

RESUMO

BACKGROUND: Previously, AF-956, which contains S356 of FAM83G and an N-terminal antenna peptide for entry into colon cancer cells, is markedly antiproliferative compared to a control peptide (AF-859), which lacks the N-terminal antenna peptide, by inducing apoptosis via the inhibition of HSP27 phosphorylation at residues S15 and S82. OBJECTIVE: Because FAM83G-derived peptides are promising lead compounds for colon cancer treatment, we reanalyzed the effect of AG-066, which contains S356 of FAM83G and an N-terminal antenna peptide for entry into the liver cancer cells. METHODS: HepG2 liver cancer cells were incubated with either AF-859 or AG-066 at a concentration of 54 µM at 37 °C for 24, 48, and 72 h. The effects of AF-859 and AG-066 on the cultured HepG2 cells were estimated using an inverted light microscope. Furthermore, the DNA ladder method and the dead cell assay were performed by applying Live/Dead Cell Staining Kit II. Erk phosphorylation was estimated by western blotting. RESULTS: Treatment with AG-066 markedly reduced HepG2 viable cell counts compared to the AF- 859-treated HepG2 cells, as evident from the significantly increased number of dead cells in the culture medium. Additionally, AG-066 treatment increased cellular DNA laddering. We found no difference in Erk phosphorylation status between the AG-066- and AF-859-treated groups. CONCLUSION: This study illustrated that the peptide with a structure based on FAM83G functions as a spontaneous apoptosis inducer for liver cancer cells. Hence, it is a promising lead compound for the treatment of liver cancer.


Assuntos
Carcinoma Hepatocelular , Neoplasias do Colo , Neoplasias Hepáticas , Humanos , Neoplasias Hepáticas/tratamento farmacológico , Apoptose , Células Hep G2 , Peptídeos/farmacologia , Proliferação de Células
3.
Biomed Res ; 42(3): 95-102, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34092754

RESUMO

Overexpressed TBC1D8B, a GTPase-activating protein, significantly reduced cultured HCT116 human colon cancer cell number. We tested N-terminal TBC1D8B, which is identical to wild type TBC1D8B from amino acid positions 1 to 427 and possesses a modified sequence from position 428 to 435 (ECGGLFLL) because of the introduction of a premature stop codon at position 436 to narrow down the minimum requirement element. The N-terminal TBC1D8B contains two GRAM domains but not the TBC domain essential for Rab-GTPase activity. The N-terminal TBC1D8B overexpression significantly reduced the cultured HCT116 cell number. When we tested C-terminal TBC1D8B, containing the portion of TBC1D8B absent in the N-terminal TBC1D8B, the cell number reduction was not observed. The N-terminal TBC1D8B overexpression significantly increased the coronin 1B expression and reduced the phosphorylation of serine 51 in eIF2α, respective markers of apoptosis and cell death/survival. Also, caspase 3 and poly ADP-ribose polymerase increased cleavage in suspended cells overexpressing the N-terminal TBC1D8B. Taken together, it is not the TBC domain for Rab-GTPase activity, but amino acids 1 to 435, including the two GRAM domains, that is enough for TBC1D8B to cause spontaneous apoptosis. TBC1D8B could be a potential anticancer therapeutic molecule.


Assuntos
Apoptose , Proteínas de Ligação ao Cálcio/fisiologia , Proteínas de Transporte Vesicular/fisiologia , Antineoplásicos/farmacologia , Morte Celular , Clonagem Molecular , Códon de Terminação , Fator de Iniciação 2 em Eucariotos/química , Proteínas Ativadoras de GTPase/química , Células HCT116 , Humanos , Fosforilação , Domínios Proteicos , Transfecção
4.
Endocr J ; 61(5): 523-7, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24705589

RESUMO

Previously we reported that the phosphorylation of Synip on serine 99 is required for Synip dissociation from Syntaxin4 and insulin-stimulated Glut4 translocation in cultured 3T3-L1 adipocytes. We also reported that the dissociated Synip remains anchored to the plasma membrane by binding to Phosphatidylinositol (3,4,5)-triphosphate. Recently Synip was reported to arrest SNARE-dependent membrane fusion as a selective t-SNARE binding inhibitor. In this study, we have found that Synip is expressed in podocytes although at a somewhat lower level than in adipocytes. To determine whether phosphorylation of Synip on serine 99 is required for insulin-stimulated Glut4 translocation and glucose uptake in podocytes we expressed a phosphorylation deficient Synip mutant (S99A-Synip) that inhibited insulin-stimulated Glut4 translocation and 2-deoxyglucose uptake in adipocytes. We conclude that serine 99 phosphorylation of Synip is required for Glut4 translocation and glucose uptake in both adipocytes and podocytes, suggesting that defects in Synip phosphorylation may underlie insulin resistance and associated diabetic nephropathy.


Assuntos
Transportador de Glucose Tipo 4/metabolismo , Glucose/metabolismo , Insulina/farmacologia , Podócitos/efeitos dos fármacos , Podócitos/metabolismo , Proteínas de Transporte Vesicular/metabolismo , Células 3T3-L1 , Adipócitos/efeitos dos fármacos , Adipócitos/metabolismo , Animais , Células Cultivadas , Camundongos , Proteína Oncogênica v-akt/metabolismo , Fosforilação , Processamento de Proteína Pós-Traducional , Transporte Proteico/efeitos dos fármacos , Proteínas de Transporte Vesicular/genética
5.
Tohoku J Exp Med ; 230(2): 87-91, 2013 06.
Artigo em Inglês | MEDLINE | ID: mdl-23759899

RESUMO

Screening of medical students and international students for tuberculosis (TB) at the time of admission is a key strategy to control and prevent the spread of infection on university campus and teaching hospitals because of the high risk of exposure to TB patients. The Mycobacterium tuberculosis antigen-specific T-cell interferon-γ release assays (IGRAs) are specific latent tuberculosis detection methods used in such groups. Currently, in Japan, there are no guidelines and no baseline data on IGRAs to evaluate the risk of TB in these high-risk groups. In order to evaluate TB risk at the time of admission in university campus and medical schools in Japan, a retrospective study was conducted. A total of 969 students (585 Japanese students and 384 international students) were screened for TB using the IGRAs at the time of admission. Eight Japanese students (0.9%) were positive for IGRAs, but none were diagnosed with active TB at the follow-up. In contrast, 30 international students (7.8%) were positive for IGRAs, including two students diagnosed with active TB during follow up. Positive ratio of IGRAs in international students was significantly higher than that of medical students at the time of admission. Here we propose a standard approach for TB screening with IGRAs at the time of admission for medical students and international students in Japan.


Assuntos
Testes de Liberação de Interferon-gama , Interferon gama/sangue , Tuberculose/sangue , Tuberculose/diagnóstico , Adolescente , Adulto , Emigrantes e Imigrantes , Feminino , Humanos , Internacionalidade , Japão , Masculino , Programas de Rastreamento/métodos , Estudos Retrospectivos , Fatores de Risco , Faculdades de Medicina , Estudantes , Estudantes de Medicina , Tuberculose/etnologia , Adulto Jovem
6.
Protein Pept Lett ; 19(9): 997-1004, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22486620

RESUMO

Nucleobindin-2 is a 420 amino acid EF-hand Ca²âº binding protein that can be further processed to generate an 82 amino terminal peptide termed Nesfatin-1. To examine the function of secreted Nucleobindin-2 in adipocyte differentiation, cultured 3T3-L1 cells were incubated with either 0 or 100 nM of GST, GST-Nucleobindin-2, prior to and during the initiation of adipocyte differentiation. Nucleobindin-2 treatment decreased neutral lipid accumulation (Oil-Red O staining) and expression of several marker genes for adipocyte differentiation (PPARγ, aP2, and adipsin). When Nucleobindin- 2 was constitutively secreted into cultured medium, cAMP content and insulin stimulated CREB phosphorylation were significantly reduced. On the other hand, intracellularly overexpressed Nucleobindin-2 failed to affect cAMP content and CREB phosphorylation. Taken together, these data indicate that secreted Nucleobindin-2 is a suppressor of adipocyte differentiation through inhibition of cAMP production and insulin signal.


Assuntos
Adipócitos/citologia , Adipogenia , Proteínas de Ligação ao Cálcio/metabolismo , Proteínas de Ligação a DNA/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Células 3T3-L1 , Adipócitos/metabolismo , Animais , Proteínas de Ligação ao Cálcio/sangue , Proteínas de Ligação ao Cálcio/química , AMP Cíclico/metabolismo , Proteínas de Ligação a DNA/sangue , Proteínas de Ligação a DNA/química , Humanos , Insulina/metabolismo , Camundongos , Proteínas do Tecido Nervoso/sangue , Proteínas do Tecido Nervoso/química , Nucleobindinas , Ratos
7.
Endocrinology ; 153(7): 3308-19, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22514047

RESUMO

Nucleobindin-2 is a 420-amino-acid EF-hand calcium-binding protein that undergoes proteolytic processing to generate an 82-amino-acid amino-terminal peptide termed nesfatin-1. To determine whether nucleobindin-2 has any biological function, nucleobindin-2 was either overexpressed or knocked down by short hairpin RNA in cultured CHO cells expressing the human insulin and epidermal growth factor (EGF) receptors (CHO/IE) and in 3T3-L1 cells. Reduction in nucleobindin-2 expression inhibited EGF-stimulated MAPK kinase (S217/S221) and Erk phosphorylation (T202/Y204). In contrast, there was no significant effect on EGF-stimulated EGF receptor phosphorylation, EGF receptor internalization, or 52-kDa Shc and c-Raf phosphorylation. Although kinase suppressor of Ras-1 and protein phosphatase 2A expression was not changed, intracellular calcium concentrations and PP2A activity was significantly increased in nucleobindin-2 knocked-down cells. Concomitant with these alterations in EGF-stimulated signaling, cell proliferation was significantly reduced in nucleobindin-2 knocked-down cells. Moreover, reduced nucleobindin-2 expression in 3T3-L1 preadipocytes resulted in a greater extent of 3T3-L1 cell adipocyte differentiation. Taken together, these data indicate that nucleobindin-2 regulates EGF-stimulated MAPK kinase/Erk signaling, cell proliferation, and adipocyte differentiation.


Assuntos
Adipócitos/citologia , Proteínas de Ligação ao Cálcio/biossíntese , Proteínas de Ligação a DNA/biossíntese , Fator de Crescimento Epidérmico/metabolismo , Receptores ErbB/metabolismo , Proteínas do Tecido Nervoso/biossíntese , Células 3T3-L1 , Animais , Células CHO , Cálcio/metabolismo , Diferenciação Celular , Proliferação de Células , Cricetinae , Eletroporação , Humanos , Camundongos , Nucleobindinas , Proteína Fosfatase 2/metabolismo , Receptor de Insulina/metabolismo , Transdução de Sinais
8.
J Biol Chem ; 286(38): 33457-65, 2011 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-21813649

RESUMO

The mechanism of TNF-α-induced insulin resistance has remained unresolved with evidence for down-regulation of insulin effector targets effects or blockade of proximal as well as distal insulin signaling events depending upon the dose, time, and cell type examined. To address this issue we examined the acute actions of TNF-α in differentiated 3T3L1 adipocytes. Acute (5-15 min) treatment with 20 ng/ml (~0.8 nm) TNF-α had no significant effect on IRS1-associated phosphatidylinositol 3-kinase. In contrast, TNF-α increased insulin-stimulated cyclin-dependent kinase-5 (CDK5) phosphorylation on tyrosine residue 15 through an Erk-dependent pathway and up-regulated the expression of the CDK5 regulator protein p35. In parallel, TNF-α stimulation also resulted in the phosphorylation and GTP loading of the Rho family GTP-binding protein, TC10α. TNF-α enhanced the depolymerization of cortical F-actin and inhibited insulin-stimulated glucose transporter-4 (GLUT4) translocation. Treatment with the MEK inhibitor, PD98059, blocked the TNF-α-induced increase in CDK5 phosphorylation and the depolymerization of cortical F-actin. Conversely, siRNA-mediated knockdown of CDK5 or treatment with the MEK inhibitor restored the impaired insulin-stimulated GLUT4 translocation induced by TNF-α. Furthermore, siRNA-mediated knockdown of p44/42 Erk also rescued the TNF-α inhibition of insulin-stimulated GLUT4 translocation. Together, these data demonstrate that TNF-α-mediated insulin resistance of glucose uptake can occur through a MEK/Erk-dependent activation of CDK5.


Assuntos
Quinase 5 Dependente de Ciclina/metabolismo , Resistência à Insulina , Fator de Necrose Tumoral alfa/farmacologia , Células 3T3-L1 , Actinas/metabolismo , Animais , Flavonoides/farmacologia , Transportador de Glucose Tipo 4/metabolismo , Guanosina Difosfato/metabolismo , Guanosina Trifosfato/metabolismo , Proteínas Substratos do Receptor de Insulina/metabolismo , Camundongos , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Fosforilação/efeitos dos fármacos , Polimerização/efeitos dos fármacos , Interferência de RNA/efeitos dos fármacos , Receptor de Insulina/metabolismo , Proteínas rho de Ligação ao GTP/metabolismo
9.
J Biol Chem ; 283(51): 35455-63, 2008 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-18948252

RESUMO

Insulin stimulation results in the activation of cyclin-dependent kinase-5 (CDK5) in lipid raft domains via a Fyn-dependent phosphorylation on tyrosine residue 15. In turn, activated CDK5 phosphorylates the Rho family GTP-binding protein TC10alpha on threonine 197 that is sensitive to the CDK5 inhibitor olomoucine and blocked by small interfering RNA-mediated knockdown of CDK5. The phosphorylation deficient mutant T197A-TC10alpha was not phosphorylated and excluded from the lipid raft domain, whereas the phosphorylation mimetic mutant (T197D-TC10alpha) was lipid raft localized. Insulin resulted in the GTP loading of T197D-TC10alpha but not T197A-TC10alpha and in parallel, T197D-TC10alpha but not T197A-TC10alpha depolymerized cortical actin and inhibited insulin-stimulated GLUT4 translocation. These data demonstrate that CDK5-dependent phosphorylation maintains TC10alpha in lipid raft compartments thereby disrupting cortical actin, whereas subsequent dephosphorylation of TC10alpha through inactivation of CDK5 allows for the re-assembly of F-actin. Because cortical actin reorganization is required for insulin-stimulated GLUT4 translocation, these data are consistent with a CDK5-dependent TC10alpha cycling between lipid raft and non-lipid raft compartments.


Assuntos
Quinase 5 Dependente de Ciclina/metabolismo , Transportador de Glucose Tipo 4/metabolismo , Insulina/farmacologia , Microdomínios da Membrana/metabolismo , Proteínas rho de Ligação ao GTP/metabolismo , Células 3T3-L1 , Actinas/genética , Actinas/metabolismo , Animais , Quinase 5 Dependente de Ciclina/antagonistas & inibidores , Quinase 5 Dependente de Ciclina/genética , Inibidores Enzimáticos/farmacologia , Transportador de Glucose Tipo 4/genética , Insulina/genética , Insulina/metabolismo , Cinetina/farmacologia , Microdomínios da Membrana/genética , Camundongos , Fosforilação/efeitos dos fármacos , Fosforilação/genética , Transporte Proteico/efeitos dos fármacos , Transporte Proteico/genética , Proteínas Proto-Oncogênicas c-fyn/genética , Proteínas Proto-Oncogênicas c-fyn/metabolismo , RNA Interferente Pequeno/genética , Proteínas rho de Ligação ao GTP/antagonistas & inibidores , Proteínas rho de Ligação ao GTP/genética
10.
Nihon Eiseigaku Zasshi ; 61(3): 332-9, 2006 May.
Artigo em Japonês | MEDLINE | ID: mdl-16768164

RESUMO

OBJECTIVES: To determine the relationship between lifestyle and hemorheology among young people, a study was conducted among healthy university students. Because few investigations have been reported on the relationship between lifestyle factors and hemorheology by gender in young people, we analyzed the effects of lifestyle on hemorheology by administering an assessment questionnaire and by measuring whole blood passage time using MC-FAN (Micro Channel array Flow ANalyzer) and hematological and blood biochemical variables for female and male university students. METHODS: The study was conducted with 40 healthy nonathlete subjects (20 females aged 19.9+/-1.3 years and 20 healthy males aged 20.6+/-1.4 years) who volunteered to participate in the study. The smoking, alcohol drinking, eating, and other habits of the subjects were investigated using a questionnaire. Blood was obtained to determine whole blood passage time and hematological and blood biochemical variables. RESULTS: The mean value of whole blood passage time was significantly shorter in females (43.4+/-5.2 sec/100 microl) than in males (58.2+/-13.6 sec/100 microl). The mean values of RBC, Hb, Ht, MCHC, Alb, TG, Cr, UA, K, Ca, Fe, AST and ALT were significantly lower in females than in males, and the mean value of HDL-C was significantly higher in females than in males. In females, Spearman's correlation coefficient showed a positive correlation between whole blood passage time and RBC, and a negative correlation between whole blood passage time and TG It also showed a positive correlation between whole blood passage time and Plt, and a negative correlation between whole blood passage time and Alb in males. Among the lifestyle factors, the mean value of whole blood passage time in females who consumed salt lightly was significantly longer than that in females who consumed salt moderately. The mean value of whole blood passage time in males who liked sweets was significantly longer than that in males who were neutral to sweets. CONCLUSIONS: The present study showed that whole blood passage time is shorter in females than in males for young people. This conforms to the pattern shown in previous studies which investigated blood passage time among the elderly and people in their prime of life. It is conceivable that females have a higher fluidity than males in all age brackets. Regarding the effects of lifestyle on hemorheology, the present study suggests that several lifestyle factors are related to whole blood passage time and their effects differ according to gender.


Assuntos
Hemorreologia , Estilo de Vida , Estudantes , Universidades , Adulto , Feminino , Humanos , Masculino , Descanso/fisiologia , Caracteres Sexuais , Inquéritos e Questionários
11.
J Cell Biol ; 168(6): 921-8, 2005 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-15753124

RESUMO

We have identified an unusual potential dual Akt/protein kinase B consensus phosphorylation motif in the protein Synip (RxKxRS(97)xS(99)). Surprisingly, serine 97 is not appreciably phosphorylated, whereas serine 99 is only a specific substrate for Akt2 but not Akt1 or Akt3. Although wild-type Synip (WT-Synip) undergoes an insulin-stimulated dissociation from Syntaxin4, the Synip serine 99 to phenylalanine mutant (S99F-Synip) is resistant to Akt2 phosphorylation and fails to display insulin-stimulated Syntaxin4 dissociation. Furthermore, overexpression of WT-Synip in 3T3L1 adipocytes had no effect on insulin-stimulated recruitment of glucose transporter 4 (GLUT4) to the plasma membrane, whereas overexpression of S99F-Synip functioned in a dominant-interfering manner by preventing insulin-stimulated GLUT4 recruitment and plasma membrane fusion. These data demonstrate that insulin activation of Akt2 specifically regulates the docking/fusion step of GLUT4-containing vesicles at the plasma membrane through the regulation of Synip phosphorylation and Synip-Syntaxin4 interaction.


Assuntos
Fusão de Membrana , Proteínas de Transporte de Monossacarídeos/metabolismo , Proteínas Musculares/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Vesículas Transportadoras/metabolismo , Proteínas de Transporte Vesicular/metabolismo , Células 3T3 , Adipócitos/efeitos dos fármacos , Adipócitos/metabolismo , Animais , Anticorpos Monoclonais/metabolismo , Western Blotting , Células CHO , Cricetinae , Cricetulus , Desoxiglucose/metabolismo , Transportador de Glucose Tipo 4 , Proteínas de Fluorescência Verde/metabolismo , Insulina/metabolismo , Cinética , Camundongos , Microscopia Confocal , Fosforilação , Testes de Precipitina , Proteínas Proto-Oncogênicas c-akt , Fatores de Tempo
12.
Endocrinology ; 145(9): 4232-43, 2004 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-15192046

RESUMO

To determine the downstream signaling pathways regulated by betacellulin (BTC) in comparison with epidermal growth factor (EGF), we used Chinese hamster ovary cells overexpressing the human EGF receptor (ErbB1/EGFR). The overall time-dependent activation of EGFR autophosphorylation was identical in cells treated with 1 nm BTC or 1.5 nm EGF. Analysis of site-specific EGFR phosphorylation demonstrated that the BTC and EGF tyrosine phosphorylation of Y1086 was not significantly different. In contrast, the autophosphorylation of Y1173 was markedly reduced in BTC-stimulated cells, compared with EGF stimulation that directly correlated with a reduced BTC stimulation of Shc tyrosine phosphorylation, Ras, and Raf-1 activation. On the other hand, Y1068 phosphorylation was significantly increased after BTC stimulation, compared with EGF in parallel with a greater extent of Erk phosphorylation. Expression of a dominant interfering MEK kinase 1 (MEKK1) and Y1068F EGFR more efficiently blocked the enhanced Erk activation by BTC, compared with EGF. Interestingly BTC had a greater inhibitory effect on apoptosis, compared with EGF, and expression of Y1068F EGFR abolished this enhanced inhibitory effect. Together, these data indicated that although BTC and EGF share overlapping signaling properties, the ability of BTC to enhance Erk activation occurs independent of Ras. The increased BTC activation results from a greater extent of Y1068 EGFR tyrosine phosphorylation and subsequent increased recruitment of the Grb2-MEKK1 complex to the plasma membrane, compared with EGF stimulation. The increased Erk activation by BTC associated with antiapoptotic function.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal , Fator de Crescimento Epidérmico/farmacologia , Receptores ErbB/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/farmacologia , MAP Quinase Quinase Quinase 1 , Transdução de Sinais/efeitos dos fármacos , Animais , Apoptose/efeitos dos fármacos , Betacelulina , Células CHO , Cricetinae , Fator de Crescimento Epidérmico/metabolismo , Receptores ErbB/genética , Proteína Adaptadora GRB2 , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Ligantes , MAP Quinase Quinase 1 , MAP Quinase Quinase 2 , MAP Quinase Quinase Quinases/metabolismo , Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Fosforilação/efeitos dos fármacos , Proteínas Tirosina Quinases/metabolismo , Proteínas/metabolismo , Proteínas Proto-Oncogênicas c-raf/metabolismo , Transdução de Sinais/fisiologia , Proteínas Son Of Sevenless/metabolismo , Tirosina/metabolismo , Proteínas ras/metabolismo , Domínios de Homologia de src/fisiologia
13.
Endocr J ; 50(5): 643-50, 2003 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-14614222

RESUMO

Glucose-dependent insulinotropic polypeptide (GIP), a peptide released from the intestines after meals, is thought to stimulate insulin secretion. GIP receptor cDNA has recently been cloned and its mRNA has been recognized in several organs including the pituitary, but the physiological roles of GIP receptors of the pituitary have yet to be determined. We have demonstrated the possibility that GIP stimulates GH secretions from the pituitary adenoma cells of acromegalics. GIP-stimulated GH responses were studied in four acromegalics. In two acromegalics whose GH showed paradoxical secretion to oral glucose tolerance test (OGTT), GIP infusion (0.6 microg/kg/h) drove GH secretion (13.7 to 68.1, 22.5 to 76.2 ng/ml, respectively). However, in the other two acromegalics whose GH showed no paradoxical response to OGTT, GIP infusion did not induce GH secretion. One of the patients who was studied extensively had a GH that responded to OGTT. This patient's serum GH levels increased after meals while adenomectomy abolished both the paradoxical GH secretions by OGTT and GH responses to the GIP infusion. These data suggested that some somatotroph adenoma cells have an aberrant response to GIP which may go toward explaining paradoxical GH secretions to OGTT in acromegalics.


Assuntos
Acromegalia/metabolismo , Polipeptídeo Inibidor Gástrico/farmacologia , Hormônio do Crescimento Humano/metabolismo , Idoso , Feminino , Polipeptídeo Inibidor Gástrico/administração & dosagem , Teste de Tolerância a Glucose , Humanos , Injeções Intravenosas , Pessoa de Meia-Idade , Período Pós-Prandial
14.
J Biol Chem ; 278(38): 36718-25, 2003 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-12855681

RESUMO

Although syntaxin 1 is generally thought to function as the primary target-N-ethylmaleimide-sensitive factor attachment protein receptor required for pancreatic beta cell insulin secretion, we have observed that overexpression of a dominant-interfering syntaxin 4 mutant (syntaxin 4/DeltaTM) attenuated glucose-stimulated insulin secretion in betaHC-9 cells. Furthermore, these cells express the selective syntaxin 4-binding protein Synip (syntaxin 4 interacting protein), and Synip was specifically co-immunoprecipitated with syntaxin 4 but not syntaxin 1. Overexpression of the full-length Synip protein (Synip/wild type) inhibited VAMP2 association with syntaxin 4 and decreased glucose-stimulated insulin secretion. This did not occur with a Synip mutant (Synip/ DeltaEF) that was incapable of binding syntaxin 4. Consistent with a functional role of syntaxin 4 in this process, expression of syntaxin 4/DeltaTM also inhibited glucose-stimulated insulin secretion. Furthermore, analysis of first and second phase insulin secretion demonstrated that syntaxin 4/DeltaTM mainly suppressed the second phase of insulin secretion. In contrast, overexpression of Synip resulted in an inhibition of both the first and second phase of glucose-stimulated insulin secretion. These data demonstrate that syntaxin 4 plays a functional role on insulin release and granule fusion in beta cells and that this process is regulated by the syntaxin 4-specific binding protein Synip.


Assuntos
Proteínas de Transporte/metabolismo , Insulina/metabolismo , Proteínas de Membrana/metabolismo , Pâncreas/citologia , Proteínas de Transporte Vesicular , Antígenos de Superfície/metabolismo , Northern Blotting , Western Blotting , Proteínas de Transporte/química , Linhagem Celular , Linhagem Celular Tumoral , DNA Complementar/metabolismo , Genes Dominantes , Glucose/metabolismo , Humanos , Secreção de Insulina , Proteínas de Membrana/química , Mutação , Proteínas do Tecido Nervoso/metabolismo , Pâncreas/metabolismo , Perfusão , Testes de Precipitina , Ligação Proteica , Estrutura Terciária de Proteína , Proteínas Qa-SNARE , Proteínas R-SNARE , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sintaxina 1 , Fatores de Tempo , Transfecção , beta-Galactosidase/metabolismo
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