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1.
J Clin Biochem Nutr ; 58(3): 216-22, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-27257347

RESUMO

Okara, a food by-product from the production of tofu and soy milk, is rich in three beneficial components: insoluble dietary fiber, ß-conglycinin, and isoflavones. Although isoflavones and ß-conglycinin have recently been shown to improve glucose tolerance, the effects of okara have not yet been elucidated. Therefore, we herein investigated the effects of okara on glucose tolerance in Goto-Kakizaki (GK) rats, a representative animal model of Japanese type 2 diabetes. Male GK rats were fed a 10% lard diet with or without 5% dry okara powder for 2 weeks and an oral glucose tolerance test was performed. Rats were then fed each diet for another week and sacrificed. The expression of genes that are the master regulators of glucose metabolism in adipose tissue was subsequently examined. No significant differences were observed in body weight gain or food intake between the two groups of GK rats. In the oral glucose tolerance test, increases in plasma glucose levels were suppressed by the okara diet. The mRNA expression levels of PPARγ, adiponectin, and GLUT4, which up-regulate the effects of insulin, were increased in epididymal adipose tissue by the okara diet. These results suggest that okara provides a useful means for treating type 2 diabetes.

2.
Biochem Biophys Res Commun ; 460(4): 1047-52, 2015 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-25843797

RESUMO

Metformin, one of the most commonly used drugs for patients with type 2 diabetes, recently has received much attention regarding its anti-cancer action. It is thought that the suppression of mTOR signaling is involved in metformin's anti-cancer action. Although liver cancer is one of the most responsive types of cancer for reduction of incidence by metformin, the molecular mechanism of the suppression of mTOR in liver remains unknown. In this study, we investigated the mechanism of the suppressing effect of metformin on mTOR signaling and cell proliferation using human liver cancer cells. Metformin suppressed phosphorylation of p70-S6 kinase, and ribosome protein S6, downstream targets of mTOR, and suppressed cell proliferation. We found that DEPTOR, an endogenous substrate of mTOR suppression, is involved in the suppressing effect of metformin on mTOR signaling and cell proliferation in human liver cancer cells. Metformin increases the protein levels of DEPTOR, intensifies binding to mTOR, and exerts a suppressing effect on mTOR signaling. This increasing effect of DEPTOR by metformin is regulated by the proteasome degradation system; the suppressing effect of metformin on mTOR signaling and cell proliferation is in a DEPTOR-dependent manner. Furthermore, metformin exerts a suppressing effect on proteasome activity, DEPTOR-related mTOR signaling, and cell proliferation in an AMPK-dependent manner. We conclude that DEPTOR-related mTOR suppression is involved in metformin's anti-cancer action in liver, and could be a novel target for anti-cancer therapy.


Assuntos
Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Neoplasias Hepáticas/tratamento farmacológico , Metformina/uso terapêutico , Serina-Treonina Quinases TOR/metabolismo , Sequência de Bases , Linhagem Celular Tumoral , Primers do DNA , Humanos , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Fosforilação , Reação em Cadeia da Polimerase , Proteínas Quinases S6 Ribossômicas/metabolismo , Transdução de Sinais
3.
J Clin Biochem Nutr ; 57(2): 140-4, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26388672

RESUMO

The isomaltulose based liquid formula (MHN-01), suppresses postprandial plasma glucose and insulin levels in healthy persons and patients with impaired glucose tolerance (IGT) or type 2 diabetes. MHN-01 intake as a part of breakfast also suppresses glucose and insulin levels after lunch, suggesting second meal effect. The objective of this study was to investigate the effects of nutritional counseling and long-term (24 weeks) MHN-01 ingestion on biomarkers of metabolic syndrome. Forty-one subjects with criteria of metabolic syndrome participated in this study composed with the control period (0-12 week) followed by nutritional counseling and the experimental period (12-36 week) followed by 200 kcal (837 kJ) of MHN-01 or dextrin-based standard balanced liquid formula (SBF) loading as a part of breakfast. In 16 of 41 subjects became to out of criteria for liquid formula loading study during control period (unqualified group). In the unqualified group, several biomarkers were improved. In experimental period, serum HbA1c levels significantly increased in SBF group (n = 12) but did not change in MHN-01 group (n = 10). Thus, intake of 837 kJ MHN-01 as a part of breakfast may be effective for suppression of deteriorating glucose metabolism in metabolic syndrome.

4.
Biochem Biophys Res Commun ; 404(1): 115-20, 2011 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-21095180

RESUMO

Gastric inhibitory polypeptide (GIP) is released from the small intestine upon meal ingestion and increases insulin secretion from pancreatic ß cells. Although the GIP receptor is known to be expressed in small intestine, the effects of GIP in small intestine are not fully understood. This study was designed to clarify the effect of GIP on intestinal glucose absorption and intestinal motility. Intestinal glucose absorption in vivo was measured by single-pass perfusion method. Incorporation of [(14)C]-glucose into everted jejunal rings in vitro was used to evaluate the effect of GIP on sodium-glucose co-transporter (SGLT). Motility of small intestine was measured by intestinal transit after oral administration of a non-absorbed marker. Intraperitoneal administration of GIP inhibited glucose absorption in wild-type mice in a concentration-dependent manner, showing maximum decrease at the dosage of 50 nmol/kg body weight. In glucagon-like-peptide-1 (GLP-1) receptor-deficient mice, GIP inhibited glucose absorption as in wild-type mice. In vitro examination of [(14)C]-glucose uptake revealed that 100 nM GIP did not change SGLT-dependent glucose uptake in wild-type mice. After intraperitoneal administration of GIP (50 nmol/kg body weight), small intestinal transit was inhibited to 40% in both wild-type and GLP-1 receptor-deficient mice. Furthermore, a somatostatin receptor antagonist, cyclosomatostatin, reduced the inhibitory effect of GIP on both intestinal transit and glucose absorption in wild-type mice. These results demonstrate that exogenous GIP inhibits intestinal glucose absorption by reducing intestinal motility through a somatostatin-mediated pathway rather than through a GLP-1-mediated pathway.


Assuntos
Polipeptídeo Inibidor Gástrico/farmacologia , Motilidade Gastrointestinal/efeitos dos fármacos , Glucose/metabolismo , Absorção Intestinal/efeitos dos fármacos , Jejuno/efeitos dos fármacos , Animais , Receptor do Peptídeo Semelhante ao Glucagon 1 , Jejuno/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Mutantes , Perfusão , Receptores de Glucagon/genética , Somatostatina/farmacologia
5.
Pharmacogenet Genomics ; 20(2): 135-8, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20016398

RESUMO

Multidrug and toxin extrusions (MATE1/SLC47A1 and MATE2-K/SLC47A2) play important roles in the renal excretion of metformin. We have previously identified the nonsynonymous MATE variants with functional defects at low allelic frequencies. The purpose of this study was to evaluate the effects of heterozygous MATE variants on the disposition of metformin in mice and humans. Pharmacokinetic parameters of metformin in Mate1(+ or -) heterozygous mice were comparable with those in Mate1(+ or +) wild-type mice. Among 48 Japanese diabetic patients, seven patients carried heterozygous MATE variant and no patient carried homozygous MATE variant. There was no significant difference in oral clearance of metformin with or without heterozygous MATE variants. In addition, creatinine clearance, but not heterozygous MATE variants, significantly improved the model fit of metformin clearance by statistical analysis using the nonlinear mixed-effects modeling program. In conclusion, heterozygous MATE variants could not influence the disposition of metformin in diabetic patients.


Assuntos
Antiporters/genética , Diabetes Mellitus/genética , Heterozigoto , Metformina/farmacocinética , Proteínas de Transporte de Cátions Orgânicos/genética , Animais , Linhagem Celular , Diabetes Mellitus/tratamento farmacológico , Feminino , Humanos , Masculino , Metformina/sangue , Metformina/uso terapêutico , Camundongos , Pessoa de Meia-Idade , Mutação/genética
6.
Biochem Biophys Res Commun ; 393(1): 73-8, 2010 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-20097174

RESUMO

SIR2 protein, an NAD-dependent deacetylase, is localized to nucleus and is involved in life span extension by calorie restriction in yeast. In mammals, among the seven SIR2 homologues (SIRT1-7), SIRT3, 4, and 5 are localized to mitochondria. As SIRT5 mRNA levels in liver are increased by fasting, the physiological role of SIRT5 was investigated in liver of SIRT5-overexpressing transgenic (SIRT5 Tg) mice. We identified carbamoyl phosphate synthetase 1 (CPS1), a key enzyme of the urea cycle that catalyzes condensation of ammonia with bicarbonate to form carbamoyl phosphate, as a target of SIRT5 by two-dimensional electrophoresis comparing mitochondrial proteins in livers of SIRT5 Tg and wild-type mice. CPS1 protein was more deacetylated and activated in liver of SIRT5 Tg mice than in wild-type. In addition, urea production was upregulated in hepatocytes of SIRT5 Tg mice. These results agree with those of a previous study using SIRT5 knockout (KO) mice. Because ammonia generated during fasting is toxic, SIRT5 protein might play a protective role by converting ammonia to non-toxic urea through deacetylation and activation of CPS1.


Assuntos
Amônia/metabolismo , Carbamoil-Fosfato Sintase (Amônia)/metabolismo , Jejum/metabolismo , Hepatócitos/enzimologia , Sirtuínas/biossíntese , Ureia/metabolismo , Acetilação , Sequência de Aminoácidos , Animais , Ativação Enzimática , Hepatócitos/ultraestrutura , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Mitocôndrias Hepáticas/enzimologia , Dados de Sequência Molecular , Peptídeos/genética , Peptídeos/metabolismo , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Sirtuínas/genética , Regulação para Cima
7.
J Nutr Sci Vitaminol (Tokyo) ; 64(4): 284-286, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30175792

RESUMO

The semi-solidified nutrition supplemented with soluble dietary fiber, xanthan gum (XG), inhibited postprandial glycemia in rats. The purpose of the present study is to examine whether XG exerts the same effects in humans. Subjects fasted for 12 h and then ingested the enteral nutrient, Meibalance with or without XG at 9 AM. Blood glucose levels were measured 0, 20, 40, 60, and 120 min after its ingestion. Postprandial blood glucose levels were lower in the XG group than in the control group. At 20 min, postprandial blood glucose levels were significantly lower in the XG group (84±5.3 mg/dL) than in the control group (107±7.8 mg/dL) (p<0.05). A significant difference was also observed in ΔAUC between the two groups. These results demonstrate that XG exerts inhibitory effects on glucose excursion in humans.


Assuntos
Nutrição Enteral/efeitos adversos , Aditivos Alimentares/uso terapêutico , Hiperglicemia/prevenção & controle , Polissacarídeos Bacterianos/uso terapêutico , Prebióticos , Adulto , Glicemia/análise , Feminino , Aditivos Alimentares/administração & dosagem , Aditivos Alimentares/química , Alimentos Formulados/efeitos adversos , Humanos , Hiperglicemia/sangue , Hipoglicemiantes/administração & dosagem , Hipoglicemiantes/química , Hipoglicemiantes/uso terapêutico , Masculino , Polissacarídeos Bacterianos/administração & dosagem , Polissacarídeos Bacterianos/química , Período Pós-Prandial , Prebióticos/administração & dosagem , Solubilidade , Adulto Jovem
8.
Diabetes Res Clin Pract ; 75(2): 127-34, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16959364

RESUMO

The spontaneously diabetic Torii (SDT) rat was recently recognized as a new animal model of non-obese type 2 diabetes. As the severe diabetic ocular complications seen in SDT rats already have been investigated, we examined another common diabetic complication, gastroenteropathy. Male SDT rats developed diabetes at 20 weeks and diarrhea at 28 weeks of age. Gastrointestinal motility was evaluated at 28 weeks by measuring the distance of small intestinal transit by oral administration of the non-absorbed marker, arabic gum. SDT rats exhibited greater intestinal transit distance than control SD rats (54.1+/-2.6% versus 43.0+/-1.2%). Insulin treatment of SDT rats begun at 20 weeks of age produced improved stool and reduced intestinal transit distance (41.4+/-0.3%). Morphologically, the SDT rats exhibited longer villi and heavier weight of intestine compared to control SD rats. These results suggest that the SDT rat may be a useful animal model for studies of diabetic gastroenteropathy.


Assuntos
Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/fisiopatologia , Gastroenteropatias/complicações , Gastroenteropatias/fisiopatologia , Motilidade Gastrointestinal , Animais , Glicemia/metabolismo , Tamanho Corporal , Peso Corporal , Diabetes Mellitus Tipo 2/sangue , Modelos Animais de Doenças , Fezes/química , Mucosa Gástrica/anatomia & histologia , Mucosa Gástrica/fisiopatologia , Mucosa Intestinal/anatomia & histologia , Mucosa Intestinal/fisiopatologia , Intestino Delgado/anatomia & histologia , Intestino Delgado/fisiopatologia , Lipídeos/análise , Masculino , Ratos , Ratos Mutantes , Ratos Sprague-Dawley , Estômago/anatomia & histologia , Estômago/fisiopatologia
9.
J Diabetes Investig ; 2017 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-28804981

RESUMO

AIMS/INTRODUCTION: Bacterial septicemia has diverse clinical symptoms including severe hypoglycemia. However, sepsis-induced hypoglycemia has not yet been examined in detail. The aim of the present study was to investigate the mechanisms underlying hypoglycemia in sepsis. MATERIALS AND METHODS: We induced endotoxin shock in rats using lipopolysaccharide (LPS). After an intraperitoneal injection of LPS, we measured gluconeogenesis using the pyruvate tolerance test. The effects of LPS on glucose metabolism were investigated in perfused livers and isolated hepatocytes. Furthermore, its effects on the production of inflammatory cytokines were examined in isolated splenocytes. The interaction between splenocytes and hepatocytes in response to LPS was investigated in vitro using a co-culture of splenocytes and hepatocytes. RESULTS: In the pyruvate tolerance test, the pretreatment with LPS decreased gluconeogenesis. The in vivo pretreatment of rats with LPS did not inhibit glucose production in perfused livers. The in vitro treatment of isolated hepatocytes with LPS did not decrease hepatic gluconeogenesis. Although LPS increased the production of inflammatory cytokines (tumor necrosis factor-α, interferon-γ, interleukin-1ß, interleukin-6 and interleukin-10) and nitric oxide in isolated splenocytes, only nitric oxide significantly inhibited gluconeogenesis in isolated hepatocytes. When splenocytes and hepatocytes were co-cultured in medium containing LPS, the messenger ribonucleic acid expression of glucose-6-phosphatase in hepatocytes was suppressed. CONCLUSIONS: LPS reduced hepatic gluconeogenesis, at least in part, by stimulating the production of nitric oxide in splenocytes. This effect could contribute to the mechanisms responsible for septicemia-induced hypoglycemia.

10.
JCI Insight ; 2(9)2017 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-28469071

RESUMO

Brown adipose tissue (BAT) is a central organ that acts to increase energy expenditure; its regulatory factors could be clinically useful in the treatment of obesity. Tetrahydrobiopterin (BH4) is an essential cofactor of tyrosine hydroxylase and nitric oxide synthase (NOS). Although BH4 regulates the known regulatory factors of BAT, such as noradrenaline (NA) and NO, participation of BH4 in BAT function remains unclear. In the present study, we investigate the role of BH4 in the regulation of BAT. Hph-1 mice, a mouse model of BH4 deficiency, exhibit obesity, adiposity, glucose intolerance, insulin resistance, and impaired BAT function. Impaired BAT function was ameliorated together with systemic metabolic disturbances by BAT transplantation from BH4-sufficient mice (control mice) into BH4-deficient mice, strongly suggesting that BH4-induced BAT has a critical role in the regulation of systemic energy metabolism. Both NA derived from the sympathetic nerve and NO derived from endothelial NOS in the blood vessels participate in the regulation of BH4. In addition, a direct effect of BH4 in the stimulation of brown adipocytes via NO is implicated. Taken together, BH4 activates BAT and regulates systemic energy metabolism; this suggests an approach for metabolic disorders, such as obesity and diabetes.

11.
Endocrinology ; 147(9): 4067-78, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16777972

RESUMO

Activation of the peroxisome proliferator-activated receptor (PPAR)-alpha increases lipid catabolism and lowers the concentration of circulating lipid, but its role in the control of glucose metabolism is not as clearly established. Here we compared PPARalpha knockout mice with wild type and confirmed that the former developed hypoglycemia during fasting. This was associated with only a slight increase in insulin sensitivity but a dramatic increase in whole-body and adipose tissue glucose use rates in the fasting state. The white sc and visceral fat depots were larger due to an increase in the size and number of adipocytes, and their level of GLUT4 expression was higher and no longer regulated by the fed-to-fast transition. To evaluate whether these adipocyte deregulations were secondary to the absence of PPARalpha from liver, we reexpresssed this transcription factor in the liver of knockout mice using recombinant adenoviruses. Whereas more than 90% of the hepatocytes were infected and PPARalpha expression was restored to normal levels, the whole-body glucose use rate remained elevated. Next, to evaluate whether brain PPARalpha could affect glucose homeostasis, we activated brain PPARalpha in wild-type mice by infusing WY14643 into the lateral ventricle and showed that whole-body glucose use was reduced. Hence, our data show that PPARalpha is involved in the regulation of glucose homeostasis, insulin sensitivity, fat accumulation, and adipose tissue glucose use by a mechanism that does not require PPARalpha expression in the liver. By contrast, activation of PPARalpha in the brain stimulates peripheral glucose use. This suggests that the alteration in adipocyte glucose metabolism in the knockout mice may result from the absence of PPARalpha in the brain.


Assuntos
Tecido Adiposo/metabolismo , Encéfalo/fisiologia , Transportador de Glucose Tipo 4/análise , Glucose/metabolismo , Fígado/fisiologia , PPAR alfa/deficiência , Adipócitos/citologia , Adipócitos/metabolismo , Tecido Adiposo/química , Animais , Glicemia/análise , Composição Corporal , Encéfalo/efeitos dos fármacos , Tamanho Celular , Jejum , Feminino , Hepatócitos/metabolismo , Hipotálamo/química , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Neuropeptídeos/genética , PPAR alfa/fisiologia , Proliferadores de Peroxissomos/administração & dosagem , Pirimidinas/administração & dosagem , RNA Mensageiro/análise , Reação em Cadeia da Polimerase Via Transcriptase Reversa
12.
Diabetes Res Clin Pract ; 74(3): 222-6, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16707190

RESUMO

Evaluation of a patient's pancreatic beta-cell function is important in both diagnosis and treatment of diabetes. We sought to determine beta-cell function with a single sampling of blood. Examination of fasting blood glucose (F-BG, mM) and C-peptide (F-CPR, nM) levels in seven post-islet-transplanted states of four patients revealed a linear relationship between F-BG and F-CPR. Assuming that normal subjects aged <40 years have 100% pancreatic beta-cell function, we developed the secretory units of islets in transplantation (SUIT) as an index of beta-cell function by the formula: 250 x F-CPR/(F-BG-3.43). The SUIT index was correlated with the stimulated C-peptide levels not only in islet-transplanted patients (R2 = 0.68, P < 0.05) but also in type 2 patients (R2 = 0.34, P < 0.001). Since the SUIT index can be calculated from data obtained at a single fasting blood sampling and predict the pancreatic beta-cell function, the formula may be a useful tool in clinical management of diabetes.


Assuntos
Diabetes Mellitus Tipo 2/terapia , Transplante das Ilhotas Pancreáticas , Ilhotas Pancreáticas/metabolismo , Glicemia , Humanos , Insulina/uso terapêutico
13.
J Clin Endocrinol Metab ; 90(6): 3174-8, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15784703

RESUMO

CONTEXT: Known genes in maturity-onset diabetes of the young account for only a fraction of families with dominantly inherited diabetes in Japan. There should be as-yet-unidentified genes that account for the rest of the patients. OBJECTIVE: To identify and characterize the mutation responsible for a Japanese family with dominantly inherited diabetes mellitus. SUBJECTS: Members of a four-generation family with dominantly inherited diabetes mellitus observed in three generations. None of the patients in this family had permanent neonatal diabetes. One had transient neonatal diabetes, one had childhood diabetes, and the others had adult-onset diabetes without autoantibodies or insulin resistance. METHODS: Screening of the chromosomal location of the gene by a genome-wide linkage analysis followed by candidate gene sequencing. Confirmation of the functional significance of the identified mutation by the population survey and the physiological analysis. RESULTS: We identified a novel mutation (C42R) in the KCNJ11 gene coding for the Kir6.2 subunit of the pancreatic ATP-sensitive potassium channel. The patch-clamp experiments using the mutated KCNJ11 showed that the mutation causes increased spontaneous open probability and reduced ATP sensitivity. The effect, however, was partially compensated by the reduction of functional ATP-sensitive potassium channel expression at the cell surface, which could account for the milder phenotype of our patients. CONCLUSIONS: These results broaden the spectrum of diabetes phenotypes caused by mutations of KCNJ11 and suggest that mutations in this gene should be taken into consideration for not only permanent neonatal diabetes but also other forms of diabetes with milder phenotypes and later onset.


Assuntos
Diabetes Mellitus Tipo 2/genética , Canais de Potássio Corretores do Fluxo de Internalização/genética , Substituição de Aminoácidos , Sequência de Bases , DNA/sangue , DNA/genética , DNA/isolamento & purificação , Primers do DNA , Condutividade Elétrica , Feminino , Genes Dominantes , Humanos , Recém-Nascido , Ativação do Canal Iônico/fisiologia , Masculino , Mutação de Sentido Incorreto , Linhagem , Canais de Potássio Corretores do Fluxo de Internalização/fisiologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transfecção
14.
Diabetes ; 51(5): 1409-18, 2002 May.
Artigo em Inglês | MEDLINE | ID: mdl-11978637

RESUMO

Mutations in the hepatocyte nuclear factor (HNF)-1alpha gene have been linked to subtype 3 of maturity-onset diabetes of the young (MODY), a disease characterized by a primary defect in insulin secretion. Here we show that the human GLUT2 gene is closely regulated by HNF-1alpha via sequences downstream of the transcriptional start site by interaction with transcriptional co-activator p300. The promoter region of the human GLUT2 gene was subcloned into luciferase expression plasmids that were transfected together with HNF-1alpha expression plasmid into a pancreatic beta-cell line, HIT-T15, to evaluate transcriptional activities. HNF-1alpha enhanced human GLUT2 promoter activity sixfold. Site-direct mutagenesis and footprint analyses showed that the HNF-1alpha binding site (+200 to +218) is critical in human GLUT2 gene expression. Furthermore, mammalian two-hybrid and immunoprecipitation studies revealed the transactivation domain of HNF-1alpha (amino acids 391-540) to interact with both the NH(2)-terminal region (amino acids 180-662) and the COOH-terminal region (amino acids 1,818-2,079) of p300. These findings demonstrated that HNF-1alpha binds to the 5'-untranslated region of GLUT2 and that p300 acts as a transcriptional co-activator for HNF-1alpha. In addition, these results provided new insight into the regulatory function of HNF-1alpha by suggesting a molecular basis for human GLUT2 gene expression.


Assuntos
Proteínas de Ligação a DNA , Proteínas de Transporte de Monossacarídeos/genética , Proteínas Nucleares/genética , Transativadores/genética , Fatores de Transcrição/genética , Regiões 5' não Traduzidas/fisiologia , Animais , Sítios de Ligação/genética , Linhagem Celular , Cricetinae , Regulação da Expressão Gênica/fisiologia , Genes Reporter , Transportador de Glucose Tipo 2 , Fator 1 Nuclear de Hepatócito , Fator 1-alfa Nuclear de Hepatócito , Fator 1-beta Nuclear de Hepatócito , Humanos , Ilhotas Pancreáticas/fisiologia , Proteínas Nucleares/metabolismo , Regiões Promotoras Genéticas/fisiologia , Transativadores/metabolismo , Fatores de Transcrição/metabolismo , Ativação Transcricional/fisiologia
15.
Metabolism ; 54(10): 1297-301, 2005 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16154427

RESUMO

The aim of the present study was to investigate the relationship between insulin resistance and tumor necrosis factor alpha (TNF-alpha) as well as soluble TNF receptors (sTNF-R), body mass index (BMI), leptin, adiponectin, and serum lipid profile including triglycerides in nonobese Japanese patients with type 2 diabetes. A total of 88 nonobese Japanese type 2 diabetic patients were studied. The duration of diabetes was 11.0 +/- 0.8 years. In conjunction with BMI, glycosylated hemoglobin (HbA1c), fasting concentrations of plasma glucose, serum lipids (triglycerides, high-density lipoprotein cholesterol, and total cholesterol), serum leptin, serum adiponectin, serum TNF-alpha, and soluble TNF receptors (sTNF-R1 and sTNF-R2) were also measured. Insulin resistance was estimated by the insulin resistance index of homeostasis model assessment. Insulin resistance was positively correlated with BMI, triglycerides, leptin, and total cholesterol and negatively correlated with adiponectin and high-density lipoprotein cholesterol. In contrast, insulin resistance was not associated with TNF-alpha, nor sTNF-R (sTNF-R1 and sTNF-R2) in our diabetic patients. There was no significant relationship between the 3 measures of TNF-alpha system (TNF-alpha, sTNF-R1, and sTNF-R2) and BMI, serum triglycerides, leptin, or adiponectin in these patients. From these results, it can be concluded that peripheral levels of TNF-alpha system activity are not a major factor responsible for insulin resistance in nonobese Japanese type 2 diabetic patients.


Assuntos
Diabetes Mellitus Tipo 2/metabolismo , Resistência à Insulina , Receptores Tipo II do Fator de Necrose Tumoral/sangue , Receptores Tipo I de Fatores de Necrose Tumoral/sangue , Fator de Necrose Tumoral alfa/análise , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Leptina/sangue , Masculino , Pessoa de Meia-Idade
16.
FEBS Lett ; 524(1-3): 199-203, 2002 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-12135767

RESUMO

When expressed in Xenopus oocytes, GLUT1, 2 and 4 transport glucosamine with V(max) values that are three- to four-fold lower than for glucose. The K(m)s for glucosamine and glucose of GLUT1 and GLUT4 were similar. In contrast, GLUT2 had a much higher apparent affinity for glucosamine than for glucose (K(m)=0.8+/-0.1 mM vs. approximately 17-20 mM). Glucosamine transport by GLUT2 was confirmed in mammalian cells and, using hepatocytes from control or GLUT2-null mice, HgCl(2)-inhibitable glucosamine uptake by liver was shown to be exclusively through GLUT2. These data have implications for glucosamine effects on impaired glucose metabolism and for structure-function studies of transporter sugar binding sites.


Assuntos
Glucosamina/metabolismo , Proteínas de Transporte de Monossacarídeos/metabolismo , Animais , Transporte Biológico , Linhagem Celular , Transportador de Glucose Tipo 2 , Hepatócitos/metabolismo , Humanos , Camundongos , Camundongos Knockout , Proteínas de Transporte de Monossacarídeos/genética , Oócitos , Transfecção , Xenopus
17.
Eur J Endocrinol ; 151(3): 407-12, 2004 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-15362972

RESUMO

OBJECTIVE: ATP-sensitive K(+) (K(ATP)) channels in pancreatic beta-cells are crucial in the regulation of glucose-induced insulin secretion. Recently, K(ATP) channel-deficient mice were generated by genetic disruption of Kir6.2, the pore-forming component of K(ATP) channels, but the mice still showed a significant insulin response after oral glucose loading in vivo. Gastric inhibitory polypeptide (GIP) is a physiological incretin that stimulates insulin release upon ingestion of nutrients. To determine if GIP is the insulinotropic factor in insulin secretion in K(ATP) channel-deficient mice, we generated double-knockout Kir6.2 and GIP receptor null mice and compared them with Kir6.2 knockout mice. METHODS: Double-knockout mice were generated by intercrossing Kir6.2-knockout mice with GIP receptor-knockout mice. An oral glucose tolerance test, insulin tolerance test and batch incubation study of pancreatic islets were performed on double-knockout mice and Kir6.2-knockout mice. RESULTS: Fasting glucose and insulin levels were similar in both groups. After oral glucose loading, blood glucose levels of double-knockout mice became elevated compared with Kir6.2-knockout mice, especially at 15 min (345+/-10 mg/dl vs 294+/-20 mg/dl, P<0.05) and 30 min (453+/-20 mg/dl vs 381+/-26 mg/dl, P<0.05). The insulin response was almost completely lost in double-knockout mice, although insulin secretion from isolated islets was stimulated by another incretin, glucagon-like peptide-1 in the double-knockout mice. Double-knockout mice and Kir6.2-knockout mice were similarly insulin sensitive as assessed by the insulin tolerance test. CONCLUSION: GIP is the major insulinotropic factor in the secretion of insulin in response to glucose load in K(ATP) channel-deficient mice.


Assuntos
Polipeptídeo Inibidor Gástrico/metabolismo , Hipoglicemiantes/metabolismo , Insulina/metabolismo , Canais de Potássio Corretores do Fluxo de Internalização/genética , Receptores dos Hormônios Gastrointestinais/genética , Animais , Glicemia , Glucose/farmacocinética , Intolerância à Glucose/metabolismo , Intolerância à Glucose/fisiopatologia , Hipoglicemiantes/farmacologia , Insulina/farmacologia , Secreção de Insulina , Ilhotas Pancreáticas/metabolismo , Jejuno/metabolismo , Camundongos , Camundongos Knockout
18.
Diabetes Res Clin Pract ; 64(3): 213-9, 2004 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15126010

RESUMO

Previous studies have established that impaired glucose tolerance (IGT) patients with fasting hyperglycemia (IGT/FH: fasting plasma glucose (FPG) level 6.1-7.0 mmol/l and 2 h PG level of 7.8-11.1 mmol/l) exhibit higher insulin resistance than those with isolated IGT (FPG level <6.1 mmol/l and 2 h PG level of 7.8-11.1 mmol/l), but the association with microalbuminuria has not been determined. Here, we evaluate the prevalence of microalbuminuria in non-diabetic Japanese males 20-70 years of age. The subjects were classified into four groups based on the results of OGTT: normal glucose tolerance (NGT: n=71), impaired fasting glucose (IFG: n=24), isolated IGT (n=36), and IGT/FH (n=23). A urinary albumin-to-creatinine ratio (ACR) from 30 to 300 microg/mg creatinine was counted as microalbuminuria. The prevalence of microalbuminuria was higher in subjects with IGT/FH than in subjects with isolated IGT (26% versus 14%). Logistic regression analysis showed microalbuminuria to be more significantly associated with IGT/FH (OR=3.82, 95% CI 1.09-13.36) than with isolated IGT (OR=1.75, 95% CI 0.50-6.17). While insulin resistance (HOMA-IR) in isolated IGT was not significantly different from that in NGT, insulin resistance in IGT/FH was significantly higher (P<0.01). Regression analysis of ACR in IGT showed a significant correlation with insulin resistance (P=0.012). Accordingly, microalbuminuria is more strongly associated with IGT/FH than with isolated IGT, most likely due to the higher insulin resistance.


Assuntos
Albuminúria/complicações , Jejum/sangue , Intolerância à Glucose/complicações , Hiperglicemia/sangue , Hiperglicemia/complicações , Adulto , Idoso , Albuminúria/diagnóstico , Albuminúria/urina , Povo Asiático/etnologia , Glicemia/química , HDL-Colesterol/sangue , Creatinina/urina , Estudos Transversais , Intolerância à Glucose/sangue , Intolerância à Glucose/diagnóstico , Teste de Tolerância a Glucose/métodos , Hemoglobinas Glicadas/química , Humanos , Hiperglicemia/diagnóstico , Resistência à Insulina , Japão/epidemiologia , Japão/etnologia , Masculino , Pessoa de Meia-Idade , Análise de Regressão , Triglicerídeos/sangue
19.
J Atheroscler Thromb ; 21(7): 730-8, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24717758

RESUMO

AIM: Chronic kidney disease (CKD) is associated with cardiovascular events. Tumor necrosis factor (TNF) and/or its receptors have been postulated to be involved in renal pathophysiology. It is unclear whether an increased TNF system activity is present before the development of apparent CKD. METHODS: Four hundred and twenty non-diabetic Japanese subjects with an estimated GFR (eGFR) greater than 60 ml/min/1.73 m(2) were recruited for measurement of the HbA1c, insulin, TNF system activity (TNF-α, soluble TNF receptor 1 (sTNF-R1) and sTNF-R2) levels and various parameters, including the lipid, high-sensitivity C-reactive protein (hsCRP), high-molecular-weight (HMW) adiponectin and leptin levels. The subjects were stratified according to the eGFR: the G1 level (eGFR ≧90 ml/min/1.73 m(2)) and the G2 level (90 >eGFR ≧60 ml/min/1.73 m(2)). RESULTS: Whereas no significant differences were observed in gender, body mass index (BMI), blood pressure, insulin, TNF-α, hsCRP, HMW adiponectin or leptin between the two groups, the values for age, HbA1c, triglycerides, sTNF-R1 and sTNF-R2 were significantly higher in the subjects with a G2 level of eGFR than in those with a G1 level. In contrast, the HDL cholesterol levels were significantly lower in the subjects with a G2 level than in those with a G1 level. Linear negative correlations were also observed between eGFR and age, BMI, HbA1c, triglycerides, sTNF-R1 and sTNFR2, respectively. A multiple logistic regression analysis revealed that only sTNF-R2 was associated with the presence of a G2 level of eGFR (Odds ratio 1.092, 95% CI 1.013-1.177, P=0.021). CONCLUSIONS: The circulating sTNF-R2 level is closely associated with the kidney function in non-diabetic Japanese subjects.


Assuntos
Biomarcadores/sangue , Nefropatias/sangue , Nefropatias/diagnóstico , Receptores Tipo II do Fator de Necrose Tumoral/sangue , Receptores Tipo I de Fatores de Necrose Tumoral/sangue , Fator de Necrose Tumoral alfa/sangue , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Seguimentos , Taxa de Filtração Glomerular , Humanos , Mediadores da Inflamação/sangue , Masculino , Pessoa de Meia-Idade , Prognóstico , Triglicerídeos/sangue
20.
Intern Med ; 52(21): 2409-15, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24190144

RESUMO

OBJECTIVE: The management of diabetes mellitus includes controlling the blood glucose level, body weight, blood pressure and serum lipid level. The coexistence of diabetes and a high low-density lipoprotein cholesterol (LDL-C) level promotes atherosclerosis of the coronary arteries and increases the risk of coronary artery disease (CAD). We compared the rates of attainment of LDL-C goals in type 2 diabetes patients receiving primary and secondary prevention therapy, the former without a history of CAD and the latter with a history of CAD. Because patients receiving secondary prevention are at greater risk of coronary events, LDL-C management is especially important in this group. This study was designed to determine how frequently diabetic patients attain their LDL-C goals and identify the reasons for the lack of attainment. METHODS: The groups were distinguished according to the patients' medical records. Contributory factors for the patients not achieving their goals were recorded in a questionnaire filled out by each patient's physician. RESULTS: The overall attainment rate in both groups was 61%. The most frequent impediment in both groups was "an LDL-C level above or below the goal at every hospital visit" followed by "continuously sufficient effects of dietary therapy only" and the "management of LDL-C by other departments or hospitals," the latter reflecting the increasing problems of polydisease and polypharmacy in diabetes care. CONCLUSION: Polydisease and polypharmacy issues in diabetes patients with a history of CAD constitute a growing barrier to medication adherence and the attainment of treatment goals.


Assuntos
LDL-Colesterol/sangue , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/tratamento farmacológico , Idoso , Doença da Artéria Coronariana/sangue , Doença da Artéria Coronariana/etiologia , Doença da Artéria Coronariana/prevenção & controle , Diabetes Mellitus Tipo 2/complicações , Cardiomiopatias Diabéticas/sangue , Cardiomiopatias Diabéticas/etiologia , Cardiomiopatias Diabéticas/prevenção & controle , Feminino , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Hipoglicemiantes/uso terapêutico , Japão , Masculino , Prevenção Primária , Fatores de Risco , Prevenção Secundária , Inquéritos e Questionários , Resultado do Tratamento
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