Transcription factor EB influences invasion and migration in oral squamous cell carcinomas.

OBJECTIVE: Transcription factor EB (TFEB) is a master regulator of lysosomal biogenesis and plays an important role in various cancers. However, the function of TFEB in oral squamous cell carcinomas has not been examined. The aim of this study was to elucidate the role of TFEB in oral squamous cell carcinomas. MATERIALS AND METHODS: Expression levels of TFEB were examined in six different human oral squamous carcinoma cells: HSC2, HSC3, HSC4, SAS, OSC20, and SCC25. Knockdown of TFEB using small interfering RNA in HSC2 and HSC4 cells was performed. Cell morphology was observed by immunofluorescence microscopy. Cell proliferation, invasion, and adhesion were analyzed. RESULTS: Expression levels of TFEB were high in HSC2, moderate in HSC4 and SCC25, and low in HSC3 and OSC20 cells. Knockdown of TFEB did not affect proliferation of HSC2 and HSC4 cells, but did induced enlargement of lysosomes and endosomes in HSC4 cells. TFEB silencing reduced invasion and migration of these HSC cell squamous carcinoma cells; however, increased cell adhesion was also observed. CONCLUSION: TFEB knockdown reduces invasion and migration of cancer cells, likely through lysosomal regulation. Taken together, TFEB influences cell invasion and migration of oral squamous cell carcinomas.

A case of insulin allergy successfully managed using multihexamer-forming insulin degludec combined with liraglutide.

BACKGROUND: Insulin allergy, one of insulin's adverse effects, is rare, especially in patients with Type 2 diabetes, but management is difficult and no effective strategy has yet been established. We experienced an insulin allergy case successfully managed with a novel combination of insulins. CASE REPORT: A 38-year-old woman started insulin therapy when diabetes was diagnosed at age 19 years. Despite poorly controlled diabetes because of poor adherence, she hoped to conceive a child and continuous subcutaneous insulin infusion was introduced using insulin aspart at age 32 years. One month thereafter, she developed skin reactions at the subcutaneous insulin infusion catheter insertion site. The patient was then tested for all rapid-acting insulin formulations, all of which triggered local reactions. She decided to continue the continuous subcutaneous infusion of human regular insulin, accompanied by oral cetirizine hydrochloride and betamethasone valerate ointment. The patient was admitted to our hospital at age 38 years with high HbA1c levels. She was tested for all long-acting insulin analogues. All results, except for insulin degludec, were positive. She discontinued continuous subcutaneous insulin infusion and switched to insulin degludec combined with liraglutide. The allergic reactions had completely disappeared and her blood glucose was well controlled by the time of discharge. CONCLUSION: Our patient was allergic to all insulin formulations except insulin degludec. Her allergic reactions completely disappeared after switching to insulin degludec. The crystallized structure of this insulin might mask its skin allergen antigenicity. Furthermore, her postprandial hyperglycaemia was successfully controlled with liraglutide. We propose multihexamer-forming ultra-long-acting insulin plus glucagon-like peptide-1 analogues as a therapeutic option for patients with insulin allergy.

A novel and selective sodium-glucose cotransporter-2 inhibitor, tofogliflozin, improves glycaemic control and lowers body weight in patients with type 2 diabetes mellitus.

AIM: To assess the efficacy, safety and tolerability of different doses of tofogliflozin, a novel, highly selective sodium-glucose cotransporter 2 (SGLT2) inhibitor, in patients with type 2 diabetes mellitus (T2DM). METHODS: In a 12-week, multicentre, multinational, randomized, double-blind, parallel-group, placebo-controlled, dose-finding study, patients with inadequate glycaemic control from diet and exercise alone, or from diet and exercise plus a stable dose of metformin, were randomized to one of five doses of tofogliflozin (2.5, 5, 10, 20, or 40 mg) or placebo. The primary efficacy endpoint was absolute change at week 12 from baseline in glycated haemoglobin (HbA1c), minus the change in the placebo group. RESULTS: Statistically significant dose-dependent reductions in HbA1c were shown in all treated groups except the 2.5-mg dose group, with a maximum reduction of 0.56% (placebo-subtracted) at the 40-mg dose, along with increased urinary glucose excretion. Metformin treatment had no substantial influence on tofogliflozin efficacy. Dose-dependent reductions in fasting plasma glucose and body weight were observed, and glucose intolerance was improved, with a trend towards blood pressure reduction. Slight increases were observed for mean ketone bodies with no abnormal change in ketone body ratio. No deaths or treatment-related serious adverse events were reported. The incidence of adverse events was similar in the placebo (37.9%) to that in the tofogliflozin group (35.9-46.3%). Withdrawal because of adverse events was rare (≤2 patients per treatment group), with similar rates of withdrawal in the placebo and tofogliflozin groups. CONCLUSIONS: A once-daily dose of tofogliflozin for 12 weeks was an effective, safe and well-tolerated treatment for T2DM.

Sitagliptin improves glycaemic excursion after a meal or after an oral glucose load in Japanese subjects with impaired glucose tolerance.

AIMS: To evaluate the efficacy and tolerability of sitagliptin in subjects with impaired glucose tolerance (IGT). METHODS: In a double-blind, parallel-group study, 242 Japanese subjects with IGT, determined by a 75-g oral glucose tolerance test (OGTT) at week -1, were randomized (1 : 1 : 1) to placebo (n = 83), sitagliptin 25 mg (n = 82) or 50 mg (n = 77) once daily for 8 weeks. Glycaemic variables were assessed using another OGTT at week 7 and meal tolerance tests (MTTs) at weeks 0 and 8. Primary and secondary endpoints were percent change from baseline in glucose total area under the curve 0-2 h (AUC(0 -2 h)) during the MTT and OGTT, respectively. RESULTS: Least squares mean percent change from baseline in glucose AUC(0 -2 h) during the MTT were -2.4, -9.5 and -11.5%, and during the OGTT were -3.7, -21.4 and -20.1% with placebo, sitagliptin 25 mg once daily, and 50 mg once daily, respectively (p < 0.001 for either sitagliptin dose vs placebo in both tests). Sitagliptin treatment enhanced early insulin response during the OGTT and decreased total insulin response, assessed as the total AUC(0 -2 h) during the MTT. Sitagliptin treatment also suppressed glucagon response during the MTT. The incidence of adverse events, including hypoglycaemia, was low and generally similar in all treatment groups. CONCLUSIONS: Treatment with sitagliptin significantly reduced glucose excursions during both an MTT and an OGTT; this effect was associated with an increase in early insulin secretion after oral glucose loading as well as a blunted glucagon response during an MTT. Sitagliptin was generally well tolerated in subjects with IGT.

Evaluation of cutoff scores for the Parkinson's disease sleep scale-2.

BACKGROUND: The Parkinson's Disease Sleep Scale (PDSS)-2 is a recently developed tool for evaluating disease-related nocturnal disturbances in patients with Parkinson's disease (PD). However, its cutoff score has not been clinically assessed. We determined the optimal cutoff score of the Japanese version of the PDSS-2. METHODS: Patients with PD (n = 146) and controls (n = 100) completed the PDSS-2 and the Pittsburgh Sleep Quality Index (PSQI). Poor sleepers were defined as having global PSQI scores >5. Optimal cutoff scores for determining poor sleepers were assessed using the receiver operating characteristic curve. RESULTS: A PDSS-2 total score ≥ 14 exhibited 82.0% sensitivity and 70.6% specificity, whereas a PDSS-2 total score ≥ 15 provided 72.1% sensitivity and 72.9% specificity in distinguishing poor sleepers (PSQI score >5) from good sleepers (PSQI ≤ 5). Nocturnal disturbances were more frequently observed in patients with PD than in controls (PDSS-2 total score ≥ 14 or ≥ 15; 51.4% vs 20%; 45.9% vs 19%). Nocturnal disturbances were associated with higher Hoehn and Yahr stages and Unified Parkinson's Disease Rating Scale motor scores, impaired quality of life, daytime sleepiness, and depressive symptoms. CONCLUSION: We suggest that PDSS-2 total scores ≥ 15 are useful for detecting poor sleepers among patients with PD.

Visceral, subcutaneous abdominal adiposity and liver fat content distribution in normal glucose tolerance, impaired fasting glucose and/or impaired glucose tolerance.

OBJECTIVES: To examine the specific distribution of liver fat content, visceral and subcutaneous adiposity in normal glucose tolerance (NGT/NGT), isolated impaired fasting glucose (iIFG), isolated impaired glucose tolerance (iIGT) and combined conditions (IFG+IGT), as well as with newly diagnosed type 2 diabetes (nT2D). DESIGN: Multicenter, international observational study: cross-sectional analysis. SUBJECTS: Two thousand five hundred and fifteen patients (50.0% women, 54.5% non-Caucasian) without previously known diabetes were recruited from 29 countries. Abdominal fat distribution was measured by computed tomography (CT). Liver fat was estimated using the CT-liver mean attenuation. RESULTS: Compared with NGT/NGT patients, increased visceral adiposity was found in iIFG, iIGT, IFG+IGT and nT2D; estimated liver fat progressively increased across these conditions. A one-s.d. increase in visceral adiposity was associated with an increased risk of having iIFG (men: odds ratio (OR) 1.41 (95% confidence interval (CI) 1.15-1.74), women: OR 1.62 (1.29-2.04)), iIGT (men: OR 1.59 (1.15-2.01), women: OR 1.30 (0.96-1.76)), IFG+IGT (men: OR 1.64 (1.27-2.13), women: OR 1.83 (1.36-2.48)) and nT2D (men: OR 1.80 (1.35-2.42), women: OR 1.73 (1.25-2.41)). A one-s.d. increase in estimated liver fat was associated with iIGT (men: OR 1.46 (1.12-1.90), women: OR 1.81 (1.41-2.35)), IFG+IGT (men: OR 1.42 (1.14-1.77), women: OR 1.74 (1.35-2.26)) and nT2D (men: OR 1.77 (1.40-2.27), women: OR 2.38 (1.81-3.18)). Subcutaneous abdominal adipose tissue showed an inverse relationship with nT2D in women (OR 0.63 (0.45-0.88)). CONCLUSIONS: Liver fat was associated with iIGT but not with iIFG, whereas visceral adiposity was associated with both. Liver fat and visceral adiposity were associated with nT2D, whereas subcutaneous adiposity showed an inverse relationship with nT2D in women.

Evi1 defines leukemia-initiating capacity and tyrosine kinase inhibitor resistance in chronic myeloid leukemia.

Relapse of chronic myeloid leukemia (CML) is triggered by stem cells with a reconstituting capacity similar to that of hematopoietic stem cells (HSCs) and CML stem cells are a source of resistance in drug therapy with tyrosine kinase inhibitors (TKIs). Ecotropic viral integration site 1 (EVI1), a key transcription factor in HSC regulation, is known to predict poor outcomes in myeloid malignancies, however, incapability of prospective isolation of EVI1-high leukemic cells precludes the functional evaluation of intraindividual EVI1-high cells. Introduction of CML into Evi1-internal ribosomal entry site (IRES)-green fluorescent protein (GFP) knock-in mice, a versatile HSC-reporter strain, enables us to separate Evi1-high CML cells from the individual. Evi1-IRES-GFP allele models of CML in chronic phase (CML-CP), by retroviral overexpression of BCR-ABL and by crossing BCR-ABL transgenic mice, revealed that Evi1 is predominantly enriched in the stem cell fraction and associated with an enhanced proliferative as well as a leukemia-initiating capacity and that Evi1-high CML-CP cells exhibit resistance to TKIs. Overexpressing BCR-ABL and NUP98-HOXA9 in Evi1-IRES-GFP knock-in mice to model CML in blast crisis (CML-BC), in which Evi1-high cells turned to be a major population as opposed to a minor population in CML-CP models, showed that Evi1-high CML-BC cells have a greater potential to recapitulate the disease and appear resistant to TKIs. Furthermore, given that Evi1 heterozygosity ameliorates CML-CP and CML-BC development and that the combination of Evi1 and BCR-ABL causes acute myeloid leukemia resembling CML-BC, Evi1 could regulate CML development as a potent driver. In addition, in human CML-CP cases, we show that EVI1 is highly expressed in stem cell-enriched CD34+CD38-CD90+ fraction at single-cell level. This is the first report to clarify directly that Evi1-high leukemic cells themselves possess the superior potential to Evi1-low cells in oncogenic self-renewal, which highlights the role of Evi1 as a valuable and a functional marker of CML stem cells.

Efficacy and safety of teneligliptin added to glimepiride in Japanese patients with type 2 diabetes mellitus: a randomized, double-blind, placebo-controlled study with an open-label, long-term extension.

AIMS: To assess the efficacy and safety of teneligliptin in combination with glimepiride in Japanese patients with type 2 diabetes mellitus (T2DM) inadequately controlled with glimepiride monotherapy. METHODS: In the initial 12-week, double-blind, placebo-controlled, parallel-group period, 194 patients [haemoglobin A1c (HbA1c): 8.4 ± 0.8%; fasting plasma glucose (FPG): 164.2 ± 28.1 mg/dl] were randomized to either teneligliptin 20 mg or placebo once daily while continuing stable glimepiride therapy. This randomized period was then followed by a 40-week, open-label period, where all patients received teneligliptin once daily. The primary endpoint was the change in HbA1c from baseline to week 12. RESULTS: Teneligliptin reduced HbA1c significantly compared with placebo at week 12. The placebo-subtracted change in HbA1c was -1.0 ± 0.1% [least-squares (LS) mean ± s.e., p < 0.001]. Teneligliptin also significantly reduced FPG and 2-h postprandial glucose (PPG) as compared with placebo at week 12; the placebo-subtracted changes were -27.1 ± 3.2 and -49.1 ± 6.2 mg/dl (LS mean ± s.e., both p < 0.001), respectively. The blood glucose-lowering effects were sustained throughout the 40-week open-label period. The incidence rates of adverse events and adverse drug reactions, including hypoglycaemia, during the double-blind randomized period were similar in both groups. Therefore, teneligliptin was generally well tolerated when used in combination with glimepiride. CONCLUSIONS: The addition of teneligliptin was effective and generally well tolerated in Japanese patients with T2DM inadequately controlled with glimepiride monotherapy. The improvements in glycaemic control were maintained for up to 52 weeks.

Teneligliptin for the treatment of type 2 diabetes.

Teneligliptin, characterized by a "J-shaped" structure formed by five consecutive rings, is a novel dipeptidyl peptidase 4 (DPP IV) inhibitor for the treatment of type 2 diabetes. Teneligliptin is eliminated via excretion with a half-life of 24.2 hours in human plasma from the kidney and metabolism involving certain enzymes. Hence, dose adjustment is not required in patients with renal impairment. A pharmacokinetic/pharmacodynamic study revealed that teneligliptin inhibits DPP IV activity over 24 hours, with elevation of activated glucagon-like peptide 1 (GLP-1) levels and the resulting suppression of postprandial hyperglycemia at all three daily meals. Monotherapy for 12 weeks significantly decreased hemoglobin A1c (HbA1c), fasting blood glucose, and 2-hour postprandial blood glucose levels in patients with type 2 diabetes. The therapeutic efficacy of teneligliptin over 52 weeks was confirmed not only as monotherapy but also as add-on therapy in patients with inadequately controlled blood glucose levels with sulfonylureas or thiazolidinediones. The incidence of adverse drug reactions was approximately 10% in all clinical studies of patients with type 2 diabetes conducted in Japan. The incidence of hypoglycemia was comparable in patients receiving teneligliptin or placebo, and no serious hypoglycemia was observed. Thus, teneligliptin is a novel antihyperglycemic agent with a preferable profile in terms of long-term efficacy and safety in patients with type 2 diabetes.

Efficacy, safety and dose-response relationship of teneligliptin, a dipeptidyl peptidase-4 inhibitor, in Japanese patients with type 2 diabetes mellitus.

AIM: To assess the efficacy, safety and dose-response relationship of once-daily teneligliptin, a novel dipeptidyl peptidase-4 inhibitor, in Japanese patients with type 2 diabetes mellitus (T2DM) inadequately controlled with diet and exercise. METHODS: In this randomized, double-blind, placebo-controlled, parallel-group study, patients (n = 324) were randomized to receive teneligliptin 10, 20 or 40 mg, or placebo, once daily before breakfast for 12 weeks. The primary endpoint was the change in haemoglobin (Hb)A1c from baseline to week 12. RESULTS: All teneligliptin-treated groups showed significantly greater reductions in HbA1c and fasting plasma glucose (FPG) than did the placebo group. The differences between the teneligliptin 10, 20 or 40 mg groups and the placebo group for the change in HbA1c were -0.9 [least-squares (LS) mean; 95% confidence interval: -1.0, -0.7], -0.9 (-1.1, -0.7) and -1.0 (-1.2, -0.9)%, respectively (all, p < 0.001). The respective LS means for FPG were -17.8 (-23.4, -12.1), -16.9 (-22.6, -11.2) and -20.0 (-25.7, -14.3) mg/dl (all, p < 0.001). There were no significant differences in HbA1c among the three doses of teneligliptin. The incidence of adverse events and adverse drug reactions was similar in each group. The incidence of hypoglycaemia was not significantly different among the four groups. CONCLUSIONS: Treatment with teneligliptin for 12 weeks provided significant and clinically meaningful reductions in HbA1c and FPG across the dose range studied and was generally well tolerated in Japanese patients with T2DM.

Assessment of cardiometabolic risk and prevalence of meeting treatment guidelines among patients with type 2 diabetes stratified according to their use of insulin and/or other diabetic medications: results from INSPIRE ME IAA.

AIM: Visceral adipose tissue (VAT) and liver fat (LF) are strongly associated with type 2 diabetes. It is not known, however, how diabetes treatment and/or risk factor management modulates the association between VAT, LF and diabetes. The aim was to determine the level of VAT and LF in patients with type 2 diabetes according to their treatment status and achievement of the American Diabetes Association's (ADA) diabetes management goals. METHODS: We performed a cross-sectional analysis of the baseline data of the International Study of the Prediction of Intra-Abdominal Adiposity and its Relationship with Cardiometabolic risk/Intra-Abdominal Adiposity (INSPIRE ME IAA), a 3-year prospective cardiometabolic imaging study conducted in 29 countries. Patients (n = 3991) were divided into four groups: (i) those without type 2 diabetes (noT2D n = 1003 men, n = 1027 women); (ii) those with type 2 diabetes but not treated with diabetes medications (T2Dnomeds n = 248 men, n = 198 women); (iii) those with type 2 diabetes and treated with diabetes medications but not yet using insulin (T2Dmeds-ins n = 591 men, n = 484 women) and (iv) those with type 2 diabetes and treated with insulin (T2Dmeds+ins n = 233 men, n = 207 women). Abdominal and liver adiposity were measured by computed tomography. RESULTS: Fewer patients with high VAT or LF achieved the ADA's goals for high-density lipoprotein cholesterol (HDL-C) or triglycerides compared to patients with low VAT or LF. Visceral adiposity (p = 0.02 men, p = 0.003 women) and LF (p = 0.0002 men, p = 0.0004 women) increased among patients who met fewer of the ADA treatment criteria, regardless of type 2 diabetes treatment. CONCLUSION: Residual cardiometabolic risk exists among patients with type 2 diabetes characterized by elevated VAT and LF.

Analysis of gene alterations of mitochondrial DNA D-loop regions to determine breast cancer clonality.

BACKGROUND: It has been a challenge to determine breast cancer clonality accurately. The aim of the present study was to assess methods using formalin-fixed paraffin-embedded (FFPE) tissue to differentiate new primary tumours from true recurrences that are associated with poorer prognoses and often require more aggressive treatment. METHODS: We investigated the novel method of analysing gene alterations of mitochondrial DNA D-loop region (GAMDDL) and compared it with the conventional method of analysing the X-chromosome-linked human androgen receptor (HUMARA). The FFPE sections of primary and secondary breast cancers, the non-neoplastic mammary gland, and lymph nodes were examined. RESULTS: Informative rates for HUMARA, GAMDDL, and combined analyses were 42.1%, 76.9%, and 89.5%, respectively. All of the 10 contralateral breast cancers were determined to be non-clonal. In contrast, 3 out of 8 (37.5%) of the ipsilateral secondary tumours shared a clonal origin with the primary tumour and were classified as true recurrences, whereas 4 out of 8 (50%) were classified as new primary tumours. CONCLUSION: GAMDDL analysis represents a novel and useful molecular method for examining the precise cell lineages of primary and secondary tumours, and was more accurate than HUMARA in determining clonality.

Depletion of homeodomain-interacting protein kinase 3 impairs insulin secretion and glucose tolerance in mice.

AIMS/HYPOTHESIS: Insufficient insulin secretion and reduced pancreatic beta cell mass are hallmarks of type 2 diabetes. Here, we focused on a family of serine-threonine kinases known as homeodomain-interacting protein kinases (HIPKs). HIPKs are implicated in the modulation of Wnt signalling, which plays a crucial role in transcriptional activity, and in pancreas development and maintenance. The aim of the present study was to characterise the role of HIPKs in glucose metabolism. METHODS: We used RNA interference to characterise the role of HIPKs in regulating insulin secretion and transcription activity. We conducted RT-PCR and western blot analyses to analyse the expression and abundance of HIPK genes and proteins in the islets of high-fat diet-fed mice. Glucose-induced insulin secretion and beta cell proliferation were measured in islets from Hipk3 ( -/- ) mice, which have impaired glucose tolerance owing to an insulin secretion deficiency. The abundance of pancreatic duodenal homeobox (PDX)-1 and glycogen synthase kinase (GSK)-3ß phosphorylation in Hipk3 ( -/- ) islets was determined by immunohistology and western blot analyses. RESULTS: We found that HIPKs regulate insulin secretion and transcription activity. Hipk3 expression was most significantly increased in the islets of high-fat diet-fed mice. Furthermore, glucose-induced insulin secretion and beta cell proliferation were decreased in the islets of Hipk3 ( -/- ) mice. Levels of PDX1 and GSK-3ß phosphorylation were significantly decreased in Hipk3 ( -/- ) islets. CONCLUSIONS/INTERPRETATION: Depletion of HIPK3 impairs insulin secretion and glucose tolerance. Decreased levels of HIPK3 may play a substantial role in the pathogenesis of type 2 diabetes.

Monocyte chemoattractant protein-1 (MCP-1) deficiency enhances alternatively activated M2 macrophages and ameliorates insulin resistance and fatty liver in lipoatrophic diabetic A-ZIP transgenic mice.

AIMS/HYPOTHESIS: Monocyte chemoattractant protein-1 (MCP-1)/chemokine (C-C motif) ligand (CCL) 2 (CCL2) secreted from white adipose tissue (WAT) in obesity has been reported to contribute to tissue macrophage accumulation and insulin resistance by inducing a chronic inflammatory state. MCP-1 has been shown to be elevated in the fatty liver of lipoatrophic A-ZIP-transgenic (A-ZIP-Tg) mice. Treatment of these mice with the CC chemokine receptor (CCR) 2 antagonist has been shown to ameliorate the hyperglycaemia, hyperinsulinaemia and hepatomegaly, in conjunction with reducing liver inflammation. However, since CCR2 antagonists can block not only MCP-1 but also MCP-2 (CCL8) and MCP-3 (CCL7), it remains unclear whether MCP-1 secreted from the liver could contribute to hyperglycaemia, hyperinsulinaemia and hepatomegaly in conjunction with liver inflammation, as well as to the M1 and M2 states of macrophage polarisation. METHODS: To address these issues, we analysed the effects of targeted disruption of MCP-1 in A-ZIP-Tg mice. RESULTS: MCP-1 deficiency alone or per se resulted in a significant amelioration of insulin resistance in A-ZIP-Tg mice, which was associated with a suppression of extracellular signal-regulated protein kinase (ERK)-1/2 and p38 mitogen-activated protein kinase (p38MAPK) phosphorylation in liver. Although MCP-1 deficiency did not reduce the expression of macrophage markers, it increased the expression of the genes encoding M2 macrophage markers such as Arg1 and Chi3l3, as well as significantly reducing the triacylglycerol content of livers from A-ZIP-Tg mice. CONCLUSIONS/ INTERPRETATION: Our data clearly indicated that MCP-1 deficiency improved insulin resistance and hepatic steatosis in A-ZIP-Tg mice and was associated with switching macrophage polarisation and suppressing ERK-1/2 and p38MAPK phosphorylation.

Protection from non-alcoholic steatohepatitis and liver tumourigenesis in high fat-fed insulin receptor substrate-1-knockout mice despite insulin resistance.

AIMS/HYPOTHESIS: Epidemiological studies have revealed that obesity and diabetes mellitus are independent risk factors for the development of non-alcoholic steatohepatitis (NASH) and hepatocellular carcinoma. However, the debate continues on whether insulin resistance as such is directly associated with NASH and liver tumourigenesis. Here, we investigated the incidence of NASH and liver tumourigenesis in Irs1 ( -/- ) mice subjected to a long-term high-fat (HF) diet. Our hypothesis was that hepatic steatosis, rather than insulin resistance may be related to the pathophysiology of these conditions. METHODS: Mice (8 weeks old, C57Bl/6J) were given free access to standard chow (SC) or an HF diet. The development of NASH and liver tumourigenesis was evaluated after mice had been on the above-mentioned diets for 60 weeks. Similarly, Irs1 ( -/- ) mice were also subjected to an HF diet for 60 weeks. RESULTS: Long-term HF diet loading, which causes obesity and insulin resistance, was sufficient to induce NASH and liver tumourigenesis in the C57Bl/6J mice. Obesity and insulin resistance were reduced by switching mice from the HF diet to SC, which also protected these mice against the development of NASH and liver tumourigenesis. However, compared with wild-type mice fed the HF diet, Irs1 ( -/- ) mice fed the HF diet were dramatically protected against NASH and liver tumourigenesis despite the presence of severe insulin resistance and marked postprandial hyperglycaemia. CONCLUSIONS/INTERPRETATION: IRS-1 inhibition might protect against HF diet-induced NASH and liver tumourigenesis, despite the presence of insulin resistance.

Effects of once-daily teneligliptin on 24-h blood glucose control and safety in Japanese patients with type 2 diabetes mellitus: a 4-week, randomized, double-blind, placebo-controlled trial.

AIM: To assess blood glucose control over 24 h and the safety of teneligliptin 10 and 20 mg, a novel dipeptidyl peptidase-4 inhibitor, in Japanese patients with type 2 diabetes mellitus inadequately controlled with diet and exercise. METHODS: Ninety-nine patients were administered teneligliptin 10 or 20 mg or placebo before breakfast for 4 weeks in a randomized, double-blind, placebo-controlled, parallel-group study. RESULTS: Both teneligliptin-treated groups showed significantly smaller 2-h postprandial glucose (2-h PPG), 24-h mean glucose and fasting plasma glucose values than the placebo group. The differences between the teneligliptin 10 mg and placebo groups in changes in 2-h PPG after each meal were -50.7 ± 7.8, -34.8 ± 9.2 and -37.5 ± 7.5 mg/dl at breakfast, lunch and dinner, respectively [least-squares (LS) means ± standard error (s.e.), all, p < 0.001]. The corresponding LS means ± s.e. for teneligliptin 20 mg versus placebo were -38.1 ± 7.8, -28.6 ± 9.2 and -36.1 ± 7.5 mg/dl, respectively (p < 0.001, p < 0.01, p < 0.001, respectively). Both doses of teneligliptin increased postprandial plasma active glucagon-like peptide-1 concentrations compared with placebo. The incidence of adverse events and drug-related adverse events was similar among groups. There were no hypoglycaemic symptoms or serious adverse events. CONCLUSIONS: Once-daily teneligliptin improved blood glucose levels over 24 h without hypoglycaemia.

Control of beta cell function and proliferation in mice stimulated by small-molecule glucokinase activator under various conditions.

AIMS/HYPOTHESIS: We investigated changes in the expression of genes involved in beta cell function and proliferation in mouse islets stimulated with glucokinase activator (GKA) in order to elucidate the mechanisms by which GKA stimulates beta cell function and proliferation. METHODS: Islets isolated from mice were used to investigate changes in the expression of genes related to beta cell function and proliferation stimulated by GKA. In addition, Irs2 knockout (Irs2 (-/-)) mice on a high-fat diet or a high-fat diet containing GKA were used to investigate the effects of GKA on beta cell proliferation in vivo. RESULTS: In wild-type mice, Irs2 and Pdx1 expression was increased by GKA. In Irs2 (-/-) mice, GKA administration increased the glucose-stimulated secretion of insulin and Pdx1 expression, but not beta cell proliferation. It was particularly noteworthy that oxidative stress inhibited the upregulation of the Irs2 and Pdx1 genes induced by GKA. Moreover, whereas neither GKA alone nor exendin-4 alone upregulated the expression of Irs2 and Pdx1 in the islets of db/db mice, prior administration of exendin-4 to the mice caused GKA to increase the expression of these genes. CONCLUSIONS/INTERPRETATION: GKA-stimulated IRS2 production affected beta cell proliferation but not beta cell function. Oxidative stress diminished the effects of GKA on the changes in expression of genes involved in beta cell function and proliferation. A combination of GKA and an incretin-related agent might therefore be effective in therapy.

Significant inverse association of marine n-3 fatty acids with plasma fibrinogen levels in Japanese in Japan but not in whites or Japanese Americans.

BACKGROUND/OBJECTIVES: Numerous studies reported beneficial effects of marine n-3 fatty acids (n-3 FAs) on cardiovascular disease (CVD) and its risk factors. However, the association of marine n-3 FAs with plasma fibrinogen, a risk factor for CVD, remains uncertain. SUBJECTS/METHODS: In a population-based, cross-sectional study of 795 men aged 40-49 without CVD (262 whites in Allegheny County, Pennsylvania, USA, 302 Japanese in Kusatsu, Japan and 229 Japanese Americans in Honolulu, Hawaii, USA), we examined the association of marine n-3 FAs with plasma fibrinogen. Serum FAs were measured by capillary gas-liquid chromatography. Marine n-3 FAs were defined as the sum of docosahexaenoic, eicosapentaenoic and docosapentaenoic acids. Plasma fibrinogen was measured by an automated clot-rate assay. Multiple linear regression analyses were performed to assess the association. RESULTS: White, Japanese and Japanese-American men had mean marine n-3 FAs levels of 3.47%, 8.78% and 4.46%, respectively. Japanese men had a significant inverse association of marine n-3 FAs with fibrinogen (standardized regression coefficient of -0.11, P=0.049), after adjusting for age, body-mass index and current smoking. The significant inverse association remained after further adjusting for diabetes, C-reactive protein, triglycerides and other variables. White or Japanese-American men did not show a significant association. CONCLUSIONS: We observed the significant inverse association of marine n-3 FAs with fibrinogen in Japanese, but not in whites or Japanese Americans. The observation suggests that marine n-3 FAs at very high levels, as seen in the Japanese, may decrease plasma fibrinogen levels.

The diabetogenic VPS13C/C2CD4A/C2CD4B rs7172432 variant impairs glucose-stimulated insulin response in 5,722 non-diabetic Danish individuals.

AIMS/HYPOTHESIS: A genome-wide association study in the Japanese population reported two genome-wide significant loci associated with type 2 diabetes of which the VPS13C/C2CD4A/C2CD4B locus was replicated in Europeans. We looked for potential associations between the diabetogenic VPS13C/C2CD4A/C2CD4B rs7172432 variant and diabetes-related intermediary traits. METHODS: We genotyped the rs7172432 variant in the population-based Inter99 cohort (n = 6,784) and analysed quantitative diabetes-related traits in 5,722 non-diabetic participants who all were examined by an OGTT. RESULTS: The diabetes-associated A allele was associated with 0.60 cm higher waist circumference (p = 0.004), 0.037 mmol/l higher fasting plasma glucose (p = 4 × 10(-5)) and 0.11 mmol/l higher plasma glucose at 30 min during an OGTT (p = 4 × 10(-4)). In analyses adjusted for concomitant insulin sensitivity levels the diabetogenic allele was associated with a lower acute glucose-stimulated insulin response (GSIR) as estimated by 30 min serum insulin (ß = -0.039, p = 2 × 10(-7)), insulinogenic index (ß = -0.057, p = 1 × 10(-8)) and BIGTT-acute insulin release (ß = -0.041, p = 9 × 10(-9)). As rs7172432 is situated in a region previously associated with glycaemic traits, we tested linkage disequilibrium (LD) with the reported regional lead single-nucleotide polymorphisms for fasting (rs11071657) and 2 h plasma glucose (rs17271305), and performed conditional analyses of rs7172432. Rs7172432 showed moderate LD with rs11071657 and rs17271305 (R (2) < 0.34) and we found strong association by almost unchanged effect sizes of rs7172432 with plasma glucose and estimates of GSIR in analyses conditional on rs11071657 and rs17271305. CONCLUSIONS/INTERPRETATION: The diabetogenic VPS13C/C2CD4A/C2CD4B rs7172432 A allele associates with GSIR in non-diabetic individuals from the general population, suggesting an impaired beta cell function as an intermediary diabetes-related trait.