Cardio-ankle vascular index is more closely associated than brachial-ankle pulse wave velocity with arterial damage and risk of cardiovascular disease in patients with diabetes.

BACKGROUND: This study aimed to compare the usefulness of arterial stiffness parameters, cardio-ankle vascular index (CAVI) and brachial-ankle pulse wave velocity (baPWV), for evaluating arterial damage and risk of cardiovascular disease (CVD) in subjects with diabetes. METHODS: The study subjects were 277 patients with type 1 or type 2 diabetes. All subjects were evaluated for vascular stiffness using CAVI (n = 154) or baPWV (n = 123). Carotid intima-media thickness (IMT) and the Suita score were also measured because these are established risk factors for future CVD. Associations of both CAVI and baPWV with these established parameters were evaluated in all subjects, and then in 174 subjects with adjustment for covariates by using propensity score matching. RESULTS: In all subjects, CAVI and baPWV correlated significantly with both IMT (r = 0.462, P < 0.001, and r = 0.212, P = 0.019, respectively) and the Suita score (r = 0.573, P < 0.001, and r = 0.373, P < 0.001, respectively). The correlation between CAVI and IMT was more significant than that between baPWV and IMT (Z = 2.33, P = 0.020). Similarly, the correlation between CAVI and the Suita score was more significant than that between baPWV and the Suita score (Z = 2.13, P = 0.033). After adjustment by propensity score matching, significant correlations between CAVI and IMT (r = 0.432 P < 0.001) and between CAVI and the Suita score (r = 0.544, P < 0.001) were preserved, though only the association between baPWV and the Suita score was significant (r = 0.289, P = 0.007) while that between baPWV and IMT showed no significance. Again, CAVI showed a significant association with the Suita score than baPWV (Z = 2.02, P = 0.043). CONCLUSIONS: CAVI is more closely associated than baPWV with arterial damage and risk of CVD in patients with diabetes.

Aortic arch calcification with pericardial fat mass detected on a single chest X-ray image is closely associated with the predictive variables of future cardiovascular disease.

This study evaluated the associations between aortic arch calcification (AAC) with pericardial fat (PF) mass detected on a single chest X-ray image and predictive variables of future cardiovascular disease (CVD). The subjects were 353 patients treated with at least one of the hypertension, dyslipidemia or diabetes. All subjects were evaluated for AAC; divided into 3 groups with AAC grades of 0, 1, or 2; and examined for the presence of PF. Carotid intima-media thickness (IMT, n = 353), cardio-ankle vascular index (CAVI, n = 218), the Suita score (n = 353), and cardiovascular risk points defined in the Hisayama study (n = 353), an assessment of the risk of future cardiovascular disease, were measured. The relationship of AAC grades, with or without PF, and CVD risks was evaluated. The IMT (1.62 ± 0.74 mm, 2.33 ± 1.26, and 2.43 ± 0.89 in patients with AAC grade 0, 1 and 2, respectively, p < 0.001), CAVI (8.09 ± 1.32, 8.71 ± 1.32, and 9.37 ± 1.17, respectively, p < 0.001), the Suita score (46.6 ± 10.7, 51.8 ± 8.3, and 54.2 ± 8.2, respectively, p < 0.001), and cardiovascular risk points (8.5 ± 2.6, 10.6 ± 2.3, and 11.5 ± 2.3, respectively, p < 0.001) were significantly elevated with AAC progression. Multinomial logistic regression analysis adjusted for clinical characteristics showed that the relative risk ratios of the Suita score or cardiovascular risk points were elevated according to the progress of AAC grade with PF. Therefore, aortic arch calcification with pericardial mass detected on a single chest X-ray image is closely associated with the predictive variables of future CVD.

Effects of GLP-1RA and SGLT2i, Alone or in Combination, on Mouse Models of Type 2 Diabetes Representing Different Disease Stages.

Glucagon-like peptide-1 receptor agonist (GLP-1RA) and sodium-dependent glucose transporter 2 inhibitor (SGLT2i), in addition to lowering glucose, have pleiotropic effects on the heart, kidneys, and liver. These drugs have thus come into widespread use for treating type 2 diabetes (T2DM). However, mechanistic comparisons and effects of combining these drugs have not been adequately studied. Employing diet-induced obese (DIO) mice and db/db mice as models of the early and advanced stages of T2DM, we evaluated effects of single or combined use of liraglutide (a GLP-1RA) and ipragliflozin (a SGLT2i). Treatments with liraglutide and/or ipragliflozin for 28 days improved glycemic control and reduced hepatic lipid accumulation similarly in DIO mice. In contrast, in db/db mice, despite similar favorable effects on fatty liver, liraglutide exerted no beneficial effects on glycemic control. Improved glycemic control in db/db mice treated with ipragliflozin was accompanied by increased pancreatic ß-cell area and insulin content, both of which tended to rise further when ipragliflozin was combined with liraglutide. Our data suggest that liraglutide is more efficient at an earlier stage and ipragliflozin can be effective in both stages. In addition, their combined use is a potential option for treating advanced stage diabetes with fatty liver disease.

Comparison of tofogliflozin versus glimepiride as the third oral agent added to metformin plus a dipeptidyl peptidase-4 inhibitor in Japanese patients with type 2 diabetes: A randomized, 24-week, open-label, controlled trial (STOP-OB).

Metformin plus a dipeptidyl peptidase-4 inhibitor (DPP-4i) is the most common therapy for Japanese patients with type 2 diabetes. This 24-week, multicentre, open-label, parallel-group trial randomized patients on dual therapy to add-on tofogliflozin (20 mg/day, n = 33) or glimepiride (0.5 mg/day, n = 31). The primary outcome was change in body fat percentage. The secondary outcomes included changes in HbA1c, fat mass, fat-free mass, liver function variables and uric acid. Tofogliflozin and glimepiride reduced HbA1c to a similar extent. Body fat percentage did not change from baseline in either group. Fat mass was reduced by tofogliflozin but was increased by glimepiride (by -2.0 ± 1.7 kg and +1.6 ± 1.6 kg, P = .002). Fat-free mass was also reduced by tofogliflozin and increased by glimepiride (by -1.3 ± 1.3 kg and +0.9 ± 2.0 kg, P < .001). Alanine aminotransferase and uric acid levels were reduced by tofogliflozin (P = .006 and P < .001, respectively). These data provide novel information useful for selecting the third oral agent for patients whose diabetes is inadequately controlled with metformin plus DPP-4i dual therapy.

A rare case of fulminant type 1 diabetes mellitus accompanied by both acute pancreatitis and myocarditis - case report.

BACKGROUND: Fulminant type 1 diabetes mellitus (FT1D) is a newly established subtype of type 1 diabetes. Its etiology has not been fully elucidated. Several cases with FT1D have exhibited pancreatitis or myocarditis. CASE PRESENTATION: We report a 31-year-old Japanese woman who showed upper abdominal pain and was admitted to a local hospital. She was initially diagnosed with acute pancreatitis based on serum amylase elevation and swelling of the pancreas on computed tomography. Four days after admission, she developed diabetic ketoacidosis and was transferred to our hospital. Her symptoms and laboratory findings met the FT1D criteria. On the 3rd hospital day, electrocardiography (ECG) showed ST-segment elevation, and serum cardiac enzymes were markedly elevated. Because she exhibited late gadolinium enhancement in the apical wall on contrast-enhanced cardiac magnetic resonance imaging, she was diagnosed as acute myocarditis. Abnormal ECG findings and elevations of biomarkers associated with myocarditis showed improvement on the next day. CONCLUSIONS: This is the first case of FT1D accompanied by both pancreatitis and myocarditis and suggests that the pathophysiology of FT1D is related to the common etiology of acute pancreatitis and myocarditis.

Hemichorea after hypoglycemic episodes with negative MRI findings in an elderly woman with poorly controlled type 2 diabetes mellitus: a case report.

BACKGROUND: Diabetic chorea appears during the course of poorly-controlled diabetes. While chorea associated with diabetes mellitus usually occurs during hyperglycemic episodes, hypoglycemia can also cause diabetic chorea. Brain magnetic resonance imaging (MRI) is useful for evaluating the pathogenesis of diabetic chorea. However, several diabetic chorea cases have reportedly not shown abnormal high-intensity in the putamen and striatum on T1-weighted images. CASE PRESENTATION: We report a 74-year-old woman who was admitted to our hospital for treatment of poorly-controlled type 2 diabetes mellitus. Intensified insulin treatment gradually normalizeed blood glucose, but on the 19th hospital day, after a blood glucose measurement of 49 mg/dL, she showed hemichorea of the left face, shoulder, arm and leg. MRI revealed no abnormalities of either the putamen or the striatum on T1-weighted images. She was treated with dopamine receptor antagonists, which alleviated her hemichorea symptoms and allowed discharge from the hospital. 1 year after the first hospitalization, she had to be readmitted because her glycemic control had markedly deteriorated. Glycemic control improved rapidly, and, because hemichorea did not recur, the dopamine receptor antagonists were stopped. 1 month later, however, hemichorea recurred. She resumed taking the dopamine receptor antagonists, resulting in immediate disappearance of the hemichorea. CONCLUSIONS: We herein describe a rare case of diabetes-associated hemichorea occurring after hypoglycemic episodes without abnormal high-intensity findings in the basal ganglia on T1-weighted images. The hemichorea relapsed with cessation of dopamine receptor antagonists. This case also underscores the importance of longitudinal assessment and treatment for hemichorea after hypoglycemic episodes, even in the absence of MRI findings, in elderly diabetic patients.

The prolyl isomerase Pin1 increases ß-cell proliferation and enhances insulin secretion.

The prolyl isomerase Pin1 binds to the phosphorylated Ser/Thr-Pro motif of target proteins and enhances their cis-trans conversion. This report is the first to show that Pin1 expression in pancreatic ß cells is markedly elevated by high-fat diet feeding and in ob/ob mice. To elucidate the role of Pin1 in pancreatic ß cells, we generated ß-cell-specific Pin1 KO (ßPin1 KO) mice. These mutant mice showed exacerbation of glucose intolerance but had normal insulin sensitivity. We identified two independent factors underlying impaired insulin secretion in the ßPin1 KO mice. Pin1 enhanced pancreatic ß-cell proliferation, as indicated by a reduced ß-cell mass in ßPin1 KO mice compared with control mice. Moreover, a diet high in fat and sucrose failed to increase pancreatic ß-cell growth in the ßPin1 KO mice, an observation to which up-regulation of the cell cycle protein cyclin D appeared to contribute. The other role of Pin1 was to activate the insulin-secretory step: Pin1 KO ß cells showed impairments in glucose- and KCl-induced elevation of the intracellular Ca2+ concentration and insulin secretion. We also identified salt-inducible kinase 2 (SIK2) as a Pin1-binding protein that affected the regulation of Ca2+ influx and found Pin1 to enhance SIK2 kinase activity, resulting in a decrease in p35 protein, a negative regulator of Ca2+ influx. Taken together, our observations demonstrate critical roles of Pin1 in pancreatic ß cells and that Pin1 both promotes ß-cell proliferation and activates insulin secretion.

Diabetes mellitus not an unfavorable factor on the prognosis of hepatitis C virus-related hepatocellular carcinoma.

AIM: Diabetes mellitus (DM) is a potential risk factor for hepatocarcinogenesis, especially in patients with hepatitis C virus (HCV) infection. We aimed to elucidate whether DM influences the surgical outcomes of patients with hepatocellular carcinoma (HCC). METHODS: Our patients were routinely controlled to keep urinary glucose excretion to less than 3.0 g/day before surgery, and the serum glucose level under 200 mg/dL after surgery. The surgical outcomes and postoperative complications of 112 patients with HCV-related HCC with DM (DM group) were compared to those of 112 propensity-matched patients without DM (non-DM group). RESULTS: After a median follow-up of 3.2 years (range, 0.2-11.3 years), the median overall (5.2 years; 95% confidence interval, 3.8-6.5 years) and recurrence-free survival (2.2 years; 1.7-2.9 years) in the DM group were not significantly different from those (6.3 years; 5.4-7.1 years, P = 0.337; and 2.2 years; 1.7-3.6 years, P = 0.613) in the non-DM group. The independent factors related to overall survival were the background liver (hazard ratio, 2.06; 95% confidence interval, 1.27-3.39, P = 0.014) and tumor differentiation grade (2.07; 1.14-4.05, P = 0.015). Thirty-two patients (28.5%) in the DM group and 32 patients (28.5%) in the non-DM group had morbidities after operation, with no significant difference between the groups (P = 1.000). Furthermore, postoperative control status of DM did not affect the prognostic outcome. CONCLUSION: Diabetes mellitus does not affect the surgical outcomes of patients with HCV-related HCC, and it is not an unfavorable factor when selecting candidates for liver resection of HCC.

Efficacy and safety of ipragliflozin as add-on therapy to insulin in Japanese patients with type 2 diabetes mellitus (IOLITE): a multi-centre, randomized, placebo-controlled, double-blind study.

AIMS: To examine the efficacy and safety of add-on ipragliflozin in Japanese patients with type 2 diabetes in the early stage of insulin therapy. METHODS: Patients treated with insulin (bolus component <30% of total daily dose) with/without a dipeptidyl peptidase-4 (DPP-4) inhibitor were randomized to receive placebo (n = 87) or ipragliflozin (n = 175) for 16 weeks. The primary endpoint was the change in glycated haemoglobin (HbA1c) from baseline. Secondary endpoints included changes in fasting plasma glucose (FPG) and metabolic hormones. Safety endpoints were also examined. RESULTS: The changes in HbA1c were 0.27% and -0.79% (2.9 and -8.7 mmol/mol) in the placebo and ipragliflozin groups, respectively (baseline: 8.62% vs 8.67% [70.8 vs 71.2 mmol/mol]), corresponding to an adjusted mean difference of -1.07% (95% confidence interval -1.24, -0.91) or -11.7 mmol/mol (-13.5, -9.9), p < .001. Ipragliflozin reduced FPG and serum C-peptide levels and body weight (all p < .001), and increased serum adiponectin levels (p = .022). There was a statistically significant interaction for use/non-use of a DPP-4 inhibitor × treatment group for the change in HbA1c (p = .042). Hypoglycaemia was the only treatment-related adverse event reported in >5% of patients (14.9% vs 29.1%). Events consistent with urinary tract infection (placebo 1.1% vs ipragliflozin 2.3%) or genital infection (0.0% and 4.0%, respectively) occurred in <5% of patients. CONCLUSION: Ipragliflozin was well tolerated and effective in insulin-treated patients, especially when used with a DPP-4 inhibitor.

DPP-IV inhibitor anagliptin exerts anti-inflammatory effects on macrophages, adipocytes, and mouse livers by suppressing NF-κB activation.

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

Addition of sitagliptin or metformin to insulin monotherapy improves blood glucose control via different effects on insulin and glucagon secretion in hyperglycemic Japanese patients with type 2 diabetes.

This study aimed to explore the effects of the dipeptidyl peptidase-4 inhibitor sitagliptin and the biguanide metformin on the secretion of insulin and glucagon, as well as incretin levels, in Japanese subjects with type 2 diabetes mellitus poorly controlled with insulin monotherapy. This was a single-center, randomized, open-label, parallel group study, enrolling 25 subjects. Eleven patients (hemoglobin A1c [HbA1c] 8.40 ± 0.96%) and 10 patients (8.10 ± 0.54%) on insulin monotherapy completed 12-week treatment with sitagliptin (50 mg) and metformin (750 mg), respectively. Before and after treatment, each subject underwent a meal tolerance test. The plasma glucose, glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), C-peptide, and glucagon responses to a meal challenge were measured. HbA1c reductions were similar in patients treated with sitagliptin (0.76 ± 0.18%) and metformin (0.77 ± 0.17%). In the sitagliptin group, glucose excursion during a meal tolerance test was reduced and accompanied by elevations in active GLP-1 and active GIP concentrations. C-peptide levels were unaltered despite reduced glucose responses, while glucagon responses were significantly suppressed (-7.93 ± 1.95% of baseline). In the metformin group, glucose excursion and incretin responses were unaltered. C-peptide levels were slightly increased but glucagon responses were unchanged. Our data indicate that sitagliptin and metformin exert different effects on islet hormone secretion in Japanese type 2 diabetic patients on insulin monotherapy. A glucagon suppressing effect of sitagliptin could be one of the factors improving blood glucose control in patients inadequately controlled with insulin therapy.

Therapy Combining Glucagon-Like Peptide-1 Receptor Agonist with Sodium-Glucose Cotransporter 2 Inhibitor Suppresses Atherosclerosis in Diabetic ApoE-Deficient Mice.

BACKGROUND: Glucagon-like peptide-1 receptor agonists (GLP-1RAs) and sodium-glucose cotransporter 2 inhibitors (SGLT2i) have beneficial effects on cardiovascular disease in addition to their glucose-lowering effects. In this study, the effects of these drugs, when used individually or in combination, on cardiovascular atherosclerotic lesion development were compared in diabetic ApoE-deficient (ApoE KO) hyperlipidemic mice. METHODS: ApoE-KO mice were treated with streptozotocin and nicotinamide, generating a type 2 diabetes model. The mice were randomly divided into four groups: vehicle-treated (untreated), liraglutide (LIRA), ipragliflozin (IPRA), and combination therapy (combo). These mice, as well as non-diabetic controls, were fed a high-fat diet. After 8 weeks of drug administration, the heart and aorta were removed and analyzed. RESULTS: Atherosclerotic lesions evaluated by oil red O (ORO) staining were significantly larger in the untreated group (13.4±0.8% of the total aortic area) than in the non-diabetic controls (4.4±0.5%, p<0.01), while being reduced in the combo group (6.0±1.0%, p<0.01) as compared with the untreated group. The ORO stain-positive area in the LIRA and IPRA groups tended to be reduced but their differences were not statistically significant. Transcript levels of Mcp1 and Sirt1 were significantly reduced and increased, respectively, in the combo compared with the untreated group, while no significant changes were observed in the monotherapy groups. CONCLUSIONS: The data suggest that combination therapy with liraglutide and ipragliflozin may be an efficient regimen for preventing the development of atherosclerosis in diabetic mice deficient in ApoE.

Trk-fused gene plays a critical role in diet-induced adipose tissue expansion and is also involved in thyroid hormone action.

Mutations in the Trk-fused gene (TFG) cause hereditary motor and sensory neuropathy with proximal dominant involvement, which reportedly has high co-incidences with diabetes and dyslipidemia, suggesting critical roles of the TFG in metabolism as well. We found that TFG expression levels in white adipose tissues (WATs) were elevated in both genetically and diet-induced obese mice and that TFG deletion in preadipocytes from the stromal vascular fraction (SVF) markedly inhibited adipogenesis. To investigate its role in vivo, we generated tamoxifen-inducible adipocyte-specific TFG knockout (AiTFG KO) mice. While a marked down-regulation of the peroxisome proliferator-activated receptor gamma target, de novo lipogenesis (DNL), and mitochondria-related gene expressions were observed in subcutaneous WAT (scWAT) from AiTFG KO mice, these effects were blunted in SVF-derived adipocytes when the TFG was deleted after differentiation into adipocytes, implying cell nonautonomous effects. Intriguingly, expressions of thyroid hormone receptors, as well as carbohydrate responsive element-binding protein ß, which mediates the metabolic actions of thyroid hormone, were drastically down-regulated in scWAT from AiTFG KO mice. Reduced DNL and thermogenic gene expressions in AiTFG KO mice might be attributable to impaired thyroid hormone action in vivo. Finally, when adipocyte TFG was deleted in either the early or the late phase of high-fat diet feeding, the former brought about an impaired expansion of epididymal WAT, whereas the latter caused prominent adipocyte cell death. TFG deletion in adipocytes markedly exacerbated hepatic steatosis in both experimental settings. Collectively, these observations indicate that the TFG plays essential roles in maintaining normal adipocyte functions, including an enlargement of adipose tissue, thyroid hormone function, and thermogenic gene expressions, and in preserving hypertrophic adipocytes.

ATF4-mediated induction of 4E-BP1 contributes to pancreatic beta cell survival under endoplasmic reticulum stress.

Endoplasmic reticulum (ER) stress-mediated apoptosis may play a crucial role in loss of pancreatic beta cell mass, contributing to the development of diabetes. Here we show that induction of 4E-BP1, the suppressor of the mRNA 5' cap-binding protein eukaryotic initiation factor 4E (eIF4E), is involved in beta cell survival under ER stress. 4E-BP1 expression was increased in islets under ER stress in several mouse models of diabetes. The Eif4ebp1 gene encoding 4E-BP1 was revealed to be a direct target of the transcription factor ATF4. Deletion of the Eif4ebp1 gene increased susceptibility to ER stress-mediated apoptosis in MIN6 beta cells and mouse islets, which was accompanied by deregulated translational control. Furthermore, Eif4ebp1 deletion accelerated beta cell loss and exacerbated hyperglycemia in mouse models of diabetes. Thus, 4E-BP1 induction contributes to the maintenance of beta cell homeostasis during ER stress and is a potential therapeutic target for diabetes.

Efficacy and Safety of Switching from Sitagliptin to Ipragliflozin in Obese Japanese Patients with Type 2 Diabetes Mellitus: A Single-Arm Multicenter Interventional Study.

BACKGROUND: Dipeptidyl peptidase-4 inhibitors have limited efficacy in improving glycemic control for obese Japanese patients with type 2 diabetes mellitus. Sodium-glucose co-transporter 2 inhibitors are recommended for use in patients with type 2 diabetes with obesity. Nevertheless, there has been no previously published study on the effect of switching from dipeptidyl peptidase-4 inhibitors to sodium-glucose co-transporter 2 inhibitors on the systemic and organic effects in obese Japanese patients with type 2 diabetes. OBJECTIVES: We evaluated the efficacy and safety of switching from sitagliptin to ipragliflozin for 24 weeks in obese Japanese patients with inadequately controlled type 2 diabetes. METHODS: Fifty-one obese patients with type 2 diabetes (body mass index > 25 kg/m2) treated with sitagliptin (50 mg) and metformin but with inadequate glycemic control (glycosylated hemoglobin [HbA1c] > 7.5% and < 9.0%) were enrolled. After a 4-week observation period, sitagliptin was switched to ipragliflozin (50 mg) for 24 weeks. The primary outcome was the change in HbA1c from baseline to the end of treatment. The secondary outcomes were changes in clinical characteristics and other biochemical variables. RESULTS: Fifty-one patients with an average HbA1c of 8.37 ± 0.48% and body mass index of 28.8 ± 3.8 kg/m2 were enrolled. Fifty patients completed the study, one patient stopped ipragliflozin at 4 weeks because of the development of hyperosmolar hyperglycemic syndrome. No significant change in HbA1c from baseline to the end of treatment was observed (- 0.02 ± 0.75%). However, fasting plasma glucose was reduced (- 16.2 ± 28.4 mg/dL, p < 0.001), and biochemical variables associated with insulin resistance, oxidative stress, and hepatic and renal functions showed significant improvements. No severe adverse effects were observed, except in the one aforementioned case. CONCLUSIONS: Switching from sitagliptin to ipragliflozin did not alter HbA1c in obese patients with type 2 diabetes, while improving parameters related to organ homeostasis. These data provide novel information useful for selecting oral anti-diabetic agents for patients with type 2 diabetes with obesity, a risk factor for developing various complications of diabetes. CLINICAL TRIAL REGISTRATION: Japan Registry of Clinical Trials identifier: jRCT#031190022.

A large-scale functional analysis of genes expressed differentially in insulin secreting MIN6 sublines with high versus mildly reduced glucose-responsiveness.

Molecular mechanisms of glucose-stimulated insulin secretion (GSIS) from pancreatic ß-cells are not fully understood. GSIS deteriorations are believed to underlie the pathogenesis of type 2 diabetes mellitus. By comparing transcript levels of 3 insulin secreting MIN6 cell sublines with strong glucose-responsiveness and 3 with mildly reduced responsiveness, we identified 630 differentially expressed genes. Using our recently developed system based on recombinase-mediated cassette exchange, we conducted large-scale generation of stable clones overexpressing such genes in the doxycycline-regulated manner. We found that overexpressions of 18, out of 83, genes altered GSIS. Sox11 ((sex determining region Y)-box 11) was selected to confirm its roles in regulating insulin secretion, and the gene was subjected to shRNA-mediated suppression. While Sox11 overexpression decreased GSIS, its suppression increased GSIS, confirming the role of Sox11 as a negative regulator of insulin secretion. Furthermore, metabolic experiments using radiolabelled glucose showed Sox11 to participate in regulating glucose metabolism. Our data suggested that overexpression screening is a feasible option for systemic functional testing to identify important genes in GSIS.

Association of Glycated Hemoglobin Level with Self-Reported Chewing Problems in Elderly Community-Dwelling Individuals in Japan.

Purpose: Chewing problems are associated with increased mortality, geriatric syndromes and poor activities of daily living. Starting in 2018, in Japan, a self-reported questionnaire investigating chewing status was implemented in the annual health checkup program. Considering the bidirectional association between hyperglycemia and poor oral health, it is hypothesized that people with self-reported chewing problems will have relatively poor glycemic profiles. We investigated the metabolic characteristics of elderly community dwellers with self-reported chewing problems, as well as the association between the problems and HbA1c levels. Patients and Methods: This was a retrospective, cross-sectional study. We reviewed the data of 1018 adults ≥ 65 years of age who had undergone an annual health checkup at Nihon University Hospital during the period from January 2019 through December 2019. The presence of chewing problems was investigated using a self-reported questionnaire constructed based on guidance provided by the Japanese government. Results: In the 1018 participants, the overall prevalence of chewing problems was 10.4%. Participants with chewing problems showed significantly higher levels and worse categories of HbA1c than those without such problems (HbA1c < 6.0%, 42.5% vs 54.8%; HbA1c 6.0-6.9%, 41.5% vs 37.0%; HbA1c ≥ 7.0%, 16.0% vs 8.2%, p = 0.008). Participants with HbA1c ≥ 7.0% have a significantly increased risk of chewing problems as compared to those with HbA1c < 6.0% (odds ratio 2.76, p = 0.002), even after adjusting for the effects of age, sex, body mass index, eating behaviors, and history of diabetes mellitus. Conclusion: HbA1c ≥ 7.0% is associated with self-reported chewing problems in elderly Japanese community-dwellers. We thus recommend a proactive assessment of oral conditions for this population.

Identification of serum metabolome signatures associated with retinal and renal complications of type 2 diabetes.

BACKGROUND: Type 2 diabetes is a common disease around the world and its major complications are diabetic retinopathy (DR) and diabetic kidney disease (DKD). Persons with type 2 diabetes with complications, especially who have both DR and DKD, have poorer prognoses than those without complications. Therefore, prevention and early identification of the complications of type 2 diabetes are necessary to improve the prognosis of persons with type 2 diabetes. The aim of this study is to identify factors associated with the development of multiple complications of type 2 diabetes. METHODS: We profiled serum metabolites of persons with type 2 diabetes with both DR and DKD (N = 141) and without complications (N = 159) using a comprehensive non-targeted metabolomics approach with mass spectrometry. Based on the serum metabolite profiles, case-control comparisons and metabolite set enrichment analysis (MSEA) were performed. RESULTS: Here we show that five metabolites (cyclohexylamine, P = 4.5 × 10-6; 1,2-distearoyl-glycero-3-phosphocholine, P = 7.3 × 10-6; piperidine, P = 4.8 × 10-4; N-acetylneuraminic acid, P = 5.1 × 10-4; stearoyl ethanolamide, P = 6.8 × 10-4) are significantly increased in those with the complications. MSEA identifies fatty acid biosynthesis as the type 2 diabetes complications-associated biological pathway (P = 0.0020). CONCLUSIONS: Our metabolome analysis identifies the serum metabolite features of the persons with type 2 diabetes with multiple complications, which could potentially be used as biomarkers.

In the management of type 2 diabetes, prevention and early identification of diabetes complications are important. In particular, people with type 2 diabetes with diabetic retinopathy (DR), affecting the eye, and diabetic kidney disease (DKD), have poorer outcomes than those without complications and need early intervention. Here, we comprehensively profiled blood metabolites, or breakdown products of the biological processes occurring in the body, of people with type 2 diabetes with both DR and DKD and those without complications. We found that five metabolites were significantly increased in those with complications, and we identified a specific metabolic pathway associated with having complications. Our analysis identified the blood metabolite features of people with type 2 diabetes with multiple complications, which could potentially be used as markers in the future.

Hepatic nuclear factor 1alpha (HNF1alpha) dysfunction down-regulates X-box-binding protein 1 (XBP1) and sensitizes beta-cells to endoplasmic reticulum stress.

Correct endoplasmic reticulum (ER) function is critical for the health of secretory cells, such as the pancreatic ß-cell, and ER stress is often a contributory factor to ß-cell death in type 2 diabetes. We have used an insulin-secreting cell line with inducible expression of dominant negative (DN) HNF1α, a transcription factor vital for correct ß-cell development and function, to show that HNF1α is required for Xbp1 transcription and maintenance of the normal ER stress response. DN HNF1α expression sensitizes the ß-cell to ER stress by directly down-regulating Xbp1 transcription, whereas Atf6 is unaffected. Furthermore, DN HNF1α alters calcium homeostasis, resulting in elevated cytoplasmic calcium and increased store-operated calcium entry, whereas mitochondrial calcium uptake is normal. Loss of function of XBP1 is toxic to the ß-cell and decreases production of the ER chaperone BiP, even in the absence of ER stress. DN HNF1α-induced sensitivity to cyclopiazonic acid can be partially rescued with the chemical chaperone tauroursodeoxycholate. Rat insulin 2 promoter-DN HNF1α mouse islets express lower levels of BiP mRNA, synthesize less insulin, and are sensitized to ER stress relative to matched control mouse islets, suggesting that this mechanism is also operating in vivo.

Involvement of endoplasmic stress protein C/EBP homologous protein in arteriosclerosis acceleration with augmented biological stress responses.

BACKGROUND: The processes of arteriosclerosis, including atherosclerosis and vascular remodeling, are affected by interactions among numerous biological pathways such as responses to inflammation, oxidative stress, and endoplasmic reticulum stress. C/EBP homologous protein (CHOP), which is well known to induce cellular apoptosis in response to severe endoplasmic reticulum stress, is reportedly upregulated in plaque lesions. METHODS AND RESULTS: We examined the effects of CHOP deficiency on 2 types of arteriosclerosis: cuff injury-induced neointimal formation and hypercholesterolemia-induced atherosclerosis. Cuff injury-induced neointimal formation was markedly inhibited in CHOP(-/-) mice with suppressed aortic expression of inflammatory factors and smooth muscle cell proliferation-related proteins. A CHOP deficiency also inhibited aortic plaque formation in hypercholesterolemic apolipoprotein E(-/-) mice with suppressed aortic expression of inflammatory factors and oxidative stress markers. Bone marrow transplantation experiments revealed that recipient CHOP deficiency significantly suppressed both cuff injury-induced neointimal formation and hypercholesterolemia-induced atherosclerotic plaque formation to a greater extent than donor CHOP deficiency, suggesting the importance of CHOP in vascular cells for arteriosclerosis progression. Furthermore, in our in vitro experiments, in not only macrophages but also endothelial and smooth muscle cell lines, endoplasmic reticulum stress inducers upregulated inflammation-, adhesion-, or smooth muscle cell proliferation-related proteins, whereas decreased CHOP expression remarkably suppressed endoplasmic reticulum stress-induced upregulation of these proteins. CONCLUSIONS: In addition to the well-known signaling for apoptosis induction, CHOP may play important roles in augmenting potentially pathological biological stress responses. This noncanonical role of CHOP, especially that expressed in vascular cells, may contribute to the progression of vascular remodeling and atherosclerosis.