Inhibition of Local Macrophage Growth Ameliorates Focal Inflammation and Suppresses Atherosclerosis.

OBJECTIVE: Macrophages play a central role in various stages of atherosclerotic plaque formation and progression. The local macrophages reportedly proliferate during atherosclerosis, but the pathophysiological significance of macrophage proliferation in this context remains unclear. Here, we investigated the involvement of local macrophage proliferation during atherosclerosis formation and progression using transgenic mice, in which macrophage proliferation was specifically suppressed. APPROACH AND RESULTS: Inhibition of macrophage proliferation was achieved by inducing the expression of cyclin-dependent kinase inhibitor 1B, also known as p27kip, under the regulation of a scavenger receptor promoter/enhancer. The macrophage-specific human p27kip Tg mice were subsequently crossed with apolipoprotein E-deficient mice for the atherosclerotic plaque study. Results showed that a reduced number of local macrophages resulted in marked suppression of atherosclerotic plaque formation and inflammatory response in the plaque. Moreover, fewer local macrophages in macrophage-specific human p27kip Tg mice helped stabilize the plaque, as evidenced by a reduced necrotic core area, increased collagenous extracellular matrix, and thickened fibrous cap. CONCLUSIONS: These results provide direct evidence of the involvement of local macrophage proliferation in formation and progression of atherosclerotic plaques and plaque stability. Thus, control of macrophage proliferation might represent a therapeutic target for treating atherosclerotic diseases.

Why do people with dementia pretend to know the correct answer? A qualitative study on the behaviour of toritsukuroi to keep up appearances.

BACKGROUND: Toritsukuroi is a particular type of behaviour intended to save face or preserve appearances. Clinicians often observe toritsukuroi in people with dementia, but current knowledge about this behaviour is based on clinicians' empirical knowledge rather than on observational studies. This study was designed to clarify which behaviours are related to toritsukuroi based on neuropsychological examinations. METHODS: The subjects were 91 outpatients with dementia. Verbal responses, with the exceptions of 'I don't know' and erroneous answers, were recorded by certificated clinical psychologists and analyzed by qualitative study procedures. A qualitative study was separately conducted by two researchers to identify themes and types of reactions. The themes found through content analysis were organized and labelled by a senior psychiatrist. RESULTS: Among the patients, 41.8% verbally responded in way to 'keep up appearances'. Six distinct thematic categories were identified through conventional content analysis: (i) refuting sudden questions; (ii) disclosing trait; (iii) disclosing experience; (iv) demonstrating slight hesitation; (v) appealing to indifference; and (vi) other. CONCLUSIONS: All the responses that we defined as being toritsukuroi reflect a denial of acquired cognitive impairment. Further study is needed to clarify the association between toritsukuroi and either cognitive function or disease specificity.

Insulin requirement profiles in Japanese hospitalized subjects with type 2 diabetes treated with basal-bolus insulin therapy.

To assess the total daily inulin dose (TDD) and contribution of basal insulin to TDD and to identify the predictive factors for insulin requirement profiles in subjects with type 2 diabetes, we retrospectively examined insulin requirement profiles of 275 hospitalized subjects treated with basal-bolus insulin therapy (BBT) (mean age, 60.1 ± 12.9 years; HbA1c, 10.2 ± 4.5%). Target plasma glucose level was set between 80 and 129 mg/dL before breakfast and between 80 and 179 mg/dL at 2-hour after each meal without causing hypoglycemia. We also analyzed the relationship between the insulin requirement profiles (TDD and basal/total daily insulin ratio [B/TD ratio]) and insulin-associated clinical parameters. The mean TDD was 0.463 ± 0.190 unit/kg/day (range, 0.16-1.13 unit/kg/day). The mean B/TD ratio was 0.300 ± 0.099 (range, 0.091-0.667). A positive correlation of TDD with B/TD ratio was revealed by linear regression analysis (r=0.129, p=0.03). Stepwise multiple regression analysis identified post-breakfast glucose levels before titrating insulin as an independent determinant of the insulin requirement profile [Std ß (standard regression coefficient) = 0.228, p<0.01 for TDD, Std ß = -0.189, p<0.01 for B/TD ratio]. The TDD was <0.6 unit/kg/day and the B/TD ratio was <0.4 in the majority (70.2%) of subjects in the present study. These findings may have relevance in improving glycemic control and decreasing the risk of hypoglycemia and weight gain in subjects with type 2 diabetes treated with BBT.

Discovery of INT131: a selective PPARγ modulator that enhances insulin sensitivity.

PPARγ is a member of the nuclear hormone receptor family and plays a key role in the regulation of glucose homeostasis. This Letter describes the discovery of a novel chemical class of diarylsulfonamide partial agonists that act as selective PPARγ modulators (SPPARγMs) and display a unique pharmacological profile compared to the thiazolidinedione (TZD) class of PPARγ full agonists. Herein we report the initial discovery of partial agonist 4 and the structure-activity relationship studies that led to the selection of clinical compound INT131 (3), a potent PPARγ partial agonist that displays robust glucose-lowering activity in rodent models of diabetes while exhibiting a reduced side-effects profile compared to marketed TZDs.

Efficacy and safety of sitagliptin as add-on therapy on glycemic control and blood glucose fluctuation in Japanese type 2 diabetes subjects ongoing with multiple daily insulin injections therapy.

To assess the efficacy and safety of adding sitagliptin, an oral dipeptidyl peptidase-4 inhibitor, in subjects with type 2 diabetes inadequately controlled with multiple daily insulin injections therapy (MDI). HbA1c, 1,5-anhydroglucitol (1,5-AG), body mass index (BMI), insulin doses, six-point self-measured plasma glucose (SMPG) profiles were assessed before, after 12 weeks, and after 24 weeks of MDI with 50 mg/day of sitagliptin in 40 subjects with type 2 diabetes. Safety endpoints included hypoglycemia and any adverse events. HbA1c significantly decreased during the first 12 weeks ( -0.64±0.60%), and was sustained over 24 weeks ( -0.69±0.85%). 1,5-AG increased significantly from 7.5±4.5 µg/mL at baseline to 9.6±5.5 µg/mL after 24 weeks. The bolus insulin dose at 12 weeks was decreased, and the mean plasma glucose, the SD of daily glucose, M-value, and the mean amplitude of glycemic excursions (MAGE) also decreased significantly as compared with baseline values. BMI and frequency of hypoglycemia were not changed significantly. Univariate linear regression analyses revealed that % change in HbA1c was significantly associated with BMI, and % changes in the indexes of glycemic instability (SD of daily glucose and MAGE) were significantly associated with age. In conclusion, adding sitagliptin to MDI significantly improved glycemic control and decreased the daily glucose fluctuation in subjects with type 2 diabetes inadequately controlled with MDI, without weight gain or an increase in the incidence of hypoglycemia. This trial was registered with UMIN (no. UMIN000010157).

[Type 2 diabetes and impaired glucose tolerance].

Due to the changes of lifestyle in Japan, the number of subjects with type 2 diabetes due to obesity has been increasing. Obesity usually accompanies with an increase of the size of fat cells, which causes the changes of adipokines, such as the decrease of adiponectin and the increase of TNFalpha and free fatty acids, and leads to insulin resistance. As it has been suggested that the capacity of insulin secretion in pancreatic beta cells of Japanese is lower than that of Caucasian, the Japanese likely to develop diabetes with mild obesity. In the treatment of type 2 diabetes accompanied with obesity, more strict diet therapy and exercise are required. In drug therapy of such patients, the drugs to improve insulin resistance, such as biguanides, thiazolidine derivatives, DPP-4 inhibitors and GLP-1 analogues should be selected.

Updates of incretin-related drugs for the treatment of type 2 diabetes.

Mechanisms of dipeptidyl peptidase-4 inhibitors, glucagon-like peptide-1 receptor agonists and glucagon-like peptide-1 receptor/glucose-dependent insulinotropic polypeptide receptor dual-agonist in glycemic control and/or weight loss.

The impact of Ca²âº/calmodulin-dependent protein kinase II on insulin gene expression in MIN6 cells.

Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) is expressed in insulin-secreting ß cells. However, the effects of CaMKII on insulin synthesis are unknown. Although Ser133 phosphorylation of cyclic AMP-responsive element-binding protein (CREB) typically increases CREB transcriptional activity, CaMKII phosphorylates CREB at Ser142 and at Ser133 to exert a dominant inhibitory effect. Our objective was to characterize the role of CaMKII in insulin gene expression. In MIN6 cells, insulin gene promoter activity was significantly down-regulated by wild-type (WT) CaMKIIδ2, but was significantly upregulated after small interfering RNA (siRNA) knockdown of CaMKIIδ expression. These results were independent of glucose concentrations and membrane depolarization. Insulin mRNA levels were also decreased by WT CaMKIIδ2 and increased by CaMKIIδ siRNA. Downregulation of insulin gene promoter activity by WT CaMKIIδ2 was partly mediated via cyclic AMP-responsive element 2 (CRE2). WT CaMKIIδ2 significantly increased CREB phosphorylation at Ser142 and significantly decreased binding to CREB binding protein (CBP), whereas kinase dead CaMKIIδ2 did not. Our results indicate that CaMKIIδ2 downregulates insulin gene expression by Ser142 phosphorylation of CREB and reducing binding of CREB to CBP.

The role of class I histone deacetylase (HDAC) on gluconeogenesis in liver.

Hepatic gluconeogenesis is crucial for glucose homeostasis. Although sirtuin 1 (Sirt1) is implicated in the regulation of gluconeogenesis in the liver, the effects of other histone deacetylases (HDAC) on gluconeogenesis are unclear. The aim of this study was to identify the role of class I HDACs in hepatic gluconeogenesis. In HepG2 cells and the liver of mice, the expressions of phosphoenol pyruvate carboxykinase (PEPCK) and hepatocyte nuclear factor 4α (HNF4α) were significantly decreased by treatment with a newly designed class I HDAC inhibitor, Ky-2. SiRNA knockdown of HDAC1 expression, but not of HDAC2 or HDAC3, in HepG2 cells decreased PEPCK and HNF4α expression. In HepG2 cells, insulin-stimulated phosphorylation of Akt and forkhead box O 1 (FoxO1) was increased by Ky-2. Pyruvate tolerance tests in Ky-2-treated high-fat-diet (HFD)-fed mice showed a marked reduction in blood glucose compared with vehicle-treated HFD mice. These data suggest that class I HDACs increase HNF4α protein expression and the transcriptional activity of FoxO1, followed by the induction of PEPCK mRNA expression and gluconeogenesis in liver.

Caloric restriction decreases ER stress in liver and adipose tissue in ob/ob mice.

Endoplasmic reticulum (ER) stress plays a crucial role in the development of insulin resistance and diabetes. Although caloric restriction (CR) improves obesity-related disorders, the effects of CR on ER stress in obesity remain unknown. To investigate how CR affects ER stress in obesity, ob/ob mice were assigned to either ad libitum (AL) (ob-AL) or CR (ob-CR) feeding (2 g food/day) for 1-4 weeks. The body weight (BW) of ob-CR mice decreased to the level of lean AL-fed littermates (lean-AL) within 2 weeks. BW of lean-AL and ob-CR mice was less than that of ob-AL mice. The ob-CR mice showed improved glucose tolerance and hepatic insulin action compared with ob-AL mice. Levels of ER stress markers such as phosphorylated PKR-like ER kinase (PERK) and eukaryotic translation initiation factor 2α and the mRNA expression of activating transcription factor 4 were significantly higher in the liver and epididymal fat from ob-AL mice compared with lean-AL mice. CR for 2 and 4 weeks significantly reduced all of these markers to less than 35% and 50%, respectively, of the levels in ob-AL mice. CR also significantly reduced the phosphorylation of insulin receptor substrate (IRS)-1 and c-Jun NH(2)-terminal kinase (JNK) in ob/ob mice. The CR-mediated decrease in PERK phosphorylation was similar to that induced by 4-phenyl butyric acid, which reduces ER stress in vivo. In conclusion, CR reduced ER stress and improved hepatic insulin action by suppressing JNK-mediated IRS-1 serine-phosphorylation in ob/ob mice.

Role of Rho-kinase in regulation of insulin action and glucose homeostasis.

Accumulating evidence indicates an important role for serine phosphorylation of IRS-1 in the regulation of insulin action. Recent studies suggest that Rho-kinase (ROK) is a mediator of insulin signaling, via interaction with IRS-1. Here we show that insulin stimulation of glucose transport is impaired when ROK is chemically or biologically inhibited in cultured adipocytes and myotubes and in isolated soleus muscle ex vivo. Inactivation of ROK also reduces insulin-stimulated IRS-1 tyrosine phosphorylation and PI3K activity. Moreover, inhibition of ROK activity in mice causes insulin resistance by reducing insulin-stimulated glucose uptake in skeletal muscle in vivo. Mass spectrometry analysis identifies IRS-1 Ser632/635 as substrates of ROK in vitro, and mutation of these sites inhibits insulin signaling. These results strongly suggest that ROK regulates insulin-stimulated glucose transport in vitro and in vivo. Thus, ROK is an important regulator of insulin signaling and glucose metabolism.

An acylic polyisoprenoid derivative, geranylgeranylacetone protects against visceral adiposity and insulin resistance in high-fat-fed mice.

Induction of heat shock protein (HSP)72 improves insulin resistance and obesity in diabetic animal models. Geranylgeranylacetone (GGA), known as an antiulcer drug, induces HSP72 and protects organs against several cellular stresses. This study investigated whether GGA administration would induce HSP72 in liver and render physiological protection against high-fat feeding in mice. A single and 4-wk oral administration of 200 mg/kg GGA was performed in high-fat diet (HFD)-fed mice. Metabolic parameters, cytokines, and gene expressions related to insulin signaling were evaluated. A single administration of GGA induced HSP72 in liver of normal chow-fed and HFD-fed mice. Insulin resistance after HFD was slightly ameliorated. Four weeks of GGA administration also increased HSP72 in liver and significantly improved insulin resistance and glucose homeostasis upon glucose challenge. Activation of c-jun NH2-terminal kinase (JNK) was attenuated, and insulin signaling was improved in the liver of HFD mice. Visceral adiposity was decreased in GGA-treated mice, accompanied by reduced leptin and increased adiponectin levels. GGA can be a novel therapeutic approach to treat metabolic syndrome as well as type 2 diabetes by improving insulin signaling and reducing adiposity. These beneficial effects of GGA could be mediated through HSP72 induction and JNK inactivation in the liver.

AMP-kinase regulates food intake by responding to hormonal and nutrient signals in the hypothalamus.

Obesity is an epidemic in Western society, and causes rapidly accelerating rates of type 2 diabetes and cardiovascular disease. The evolutionarily conserved serine/threonine kinase, AMP-activated protein kinase (AMPK), functions as a 'fuel gauge' to monitor cellular energy status. We investigated the potential role of AMPK in the hypothalamus in the regulation of food intake. Here we report that AMPK activity is inhibited in arcuate and paraventricular hypothalamus (PVH) by the anorexigenic hormone leptin, and in multiple hypothalamic regions by insulin, high glucose and refeeding. A melanocortin receptor agonist, a potent anorexigen, decreases AMPK activity in PVH, whereas agouti-related protein, an orexigen, increases AMPK activity. Melanocortin receptor signalling is required for leptin and refeeding effects on AMPK in PVH. Dominant negative AMPK expression in the hypothalamus is sufficient to reduce food intake and body weight, whereas constitutively active AMPK increases both. Alterations of hypothalamic AMPK activity augment changes in arcuate neuropeptide expression induced by fasting and feeding. Furthermore, inhibition of hypothalamic AMPK is necessary for leptin's effects on food intake and body weight, as constitutively active AMPK blocks these effects. Thus, hypothalamic AMPK plays a critical role in hormonal and nutrient-derived anorexigenic and orexigenic signals and in energy balance.

Angptl 4 deficiency improves lipid metabolism, suppresses foam cell formation and protects against atherosclerosis.

Angiopoietin-like protein family 4 (Angptl 4) has been shown to regulate lipoprotein metabolism through the inhibition of lipoprotein lipase (LPL). We generated ApoE(-/-)Angptl 4(-/-) mice to study the effect of Angptl 4 deficiency on lipid metabolism and atherosclerosis. Fasting and postolive oil-loaded triglyceride (TG) levels were largely decreased in ApoE(-/-)Angptl 4(-/-) mice compared with and ApoE(-/-)Angptl 4(+/+) mice. There was a significant (75+/-12%) reduction in atherosclerotic lesion size in ApoE(-/-)Angptl 4(-/-) mice compared with ApoE(-/-) Angptl 4(+/+) mice. Peritoneal macrophages, isolated from Angptl 4(-/-) mice to investigate the foam cell formation, showed a significant decrease in newly synthesized cholesteryl ester (CE) accumulation induced by acetyl low-density lipoprotein (acLDL) compared with those from Angptl 4(+/+) mice. Thus, genetic knockout of Angptl 4 protects ApoE(-/-) mice against development and progression of atherosclerosis and strongly suppresses the ability of the macrophages to become foam cells in vitro.

Impacts of the 2016 Kumamoto Earthquake on glycemic control in patients with diabetes.

AIMS/INTRODUCTION: On April 14 and 16 2016, the Kumamoto area was severely damaged by several massive magnitude 7 class earthquakes. MATERIALS AND METHODS: To examine the effects of these earthquakes on glycemic control and stress factors, glycated hemoglobin, glycated albumin, other biochemical parameters, a self-administered lifestyle-associated questionnaire and disaster-associated stress scores were analyzed. A total of 557 patients with diabetes were enrolled, and data were collected at 13 months before to 13 months after the earthquakes. RESULTS: In patients with type 1 diabetes and specific types of diabetes due to other causes, glycemic control was not altered during the observational period. This glycemic stability in type 1 diabetes might result from self-management of insulin doses. In patients with type 2 diabetes, glycated hemoglobin decreased by 0.11% (from 7.33 to 7.22%) at 1-2 months after the earthquakes, and increased thereafter. The reduction of glycated hemoglobin after 1-2 months in type 2 diabetes was associated with 'early restoration of lifelines' and 'sufficient sleep.' The glycemic deterioration at a later stage was related to 'shortage of antidiabetic agents,' 'insufficient amount of food,' 'largely destroyed houses' and 'changes in working environments.' Disaster-associated stress levels were positively correlated with 'age,' 'delayed restoration of lifelines,' 'self-management of antidiabetic agents' and 'increased amount of physical activity/exercise,' and negatively associated with 'early restoration of lifelines' and 'sufficient sleep.' CONCLUSIONS: Glycemic control, associated factors and stress levels are altered in chronological order. Post-disaster diabetic medical care must consider these corresponding points in accordance with the time-period.

Rottlerin activates AMPK possibly through LKB1 in vascular cells and tissues.

AMP-activated protein kinase (AMPK) is a cellular energy sensor involved in multiple cell signaling pathways that has become an attractive therapeutic target for vascular diseases. It is not clear whether rottlerin, an inhibitor of protein kinase Cdelta, activates AMPK in vascular cells and tissues. In the present study, we have examined the effect of rottlerin on AMPK in vascular smooth muscle cells (VSMCs) and isolated rabbit aorta. Rottlerin reduced cellular ATP and activated AMPK in VSMCs and rabbit aorta; however, inhibition of PKCdelta by three different methods did not activate AMPK. Both VSMCs and rabbit aorta expressed the upstream AMPK kinase LKB1 protein, and rottlerin-induced AMPK activation was decreased in VSMCs by overexpression of dominant-negative LKB1, suggesting that LKB1 is involved in the upstream regulation of AMPK stimulated by rottlerin. These data suggest for the first time that LKB1 mediates rottlerin-induced activation of AMPK in vascular cells and tissues.

Impacts of tight multifactorial intervention in patients with type 2 diabetes: Implications from the Japan Diabetes Outcome Intervention Trial 3.

Effects of intensive versus conventional therapy on the primary and secondary outcomes.

Are saving appearance responses typical communication patterns in Alzheimer's disease?

INTRODUCTION: To keep up appearances, people with dementia sometimes pretend to know the correct answer, as seen during administration of neuropsychological tests such as the Mini-Mental State Examination (MMSE). These saving appearance responses (SARs) of people with dementia often lead to caregivers and/or medical staff underestimating the severity of dementia and impede proper early initiation of treatment. However, most descriptions of SARs are based on empirical knowledge of clinicians. In this study, we investigated whether SARs are typical communication patterns in people with Alzheimer's disease (AD), compared with mild cognitive impairment (MCI) or dementia with Lewy bodies (DLB). METHODS: The participants were 107 outpatients with AD, 16 with mixed AD with cerebrovascular dementia, 55 with MCI, and 30 with DLB. We assessed the occurrence of SARs during the MMSE. The relationships between the SARs and AD were examined by the χ2 test and logistic regression analysis. RESULTS: People with AD who showed SARs were 57.9%, whereas those with MCI were 18.2% and DLB were 20.0% (P with Bonferroni correction < 0.05). Although there were significant differences in some variables in each group of diagnosis, logistic regression analysis showed that people with AD were more likely to show SARs than those with MCI (Odds ratio = 3.48, 95% Confidential Interval = 1.18-10.28) and DLB (Odds ratio = 4.24, 95% Confidential Interval = 1.50-12.01), even after controlling for sex, estimated disease duration, MMSE, and frontal assessment battery scores. CONCLUSION: The occurrence of SARs could be found most frequently in people with AD. Clinicians should develop a respectful attitude toward dementia patients with SARs because SARs imply conflicted feelings about questions that patients cannot answer correctly.

Identification of microRNA that represses IRS-1 expression in liver.

MicroRNAs (miRNAs) are short, non-coding RNAs that post-transcriptionally regulate gene expression and have been shown to participate in almost every cellular process. Several miRNAs have recently been implicated in glucose metabolism, but the roles of miRNAs in insulin-resistant conditions, such as obesity or type 2 diabetes, are largely unknown. Herein, we focused on miR-222, the expression of which was increased in the livers of high fat/high sucrose diet-fed mice injected with gold thioglucose (G+HFHSD). Overexpression of miR-222 in primary mouse hepatocytes attenuated Akt phosphorylation induced by insulin, indicating that miR-222 negatively regulates insulin signaling. As per in silico analysis, miR-222 potentially binds to the 3' untranslated region (3' UTR) of the IRS-1 gene, a key insulin signaling molecule. In fact, IRS-1 protein expression was decreased in the livers of G+HFHSD-fed mice. We further confirmed a direct interaction between miR-222 and the 3' UTR of IRS-1 via luciferase assays. Our findings suggest that up-regulation of miR-222 followed by reduction in IRS-1 expression may be a viable mechanism of insulin resistance in the liver.

IRS-1 transgenic mice show increased epididymal fat mass and insulin resistance.

Insulin receptor substrate-1 (IRS-1) is the major substrate of both the insulin receptor and the IGF-1 receptor. In this study, we created IRS-1 transgenic (IRS-1-Tg) mice which express human IRS-1 cDNA under control of the mouse IRS-1 gene promoter. In the IRS-1-Tg mice, IRS-1 mRNA expression was significantly increased in almost all tissues, but its protein expression was increased in very limited tissues (epididymal fat and skeletal muscle). IRS-1-Tg mice showed glucose intolerance and significantly enlarged epididymal fat mass, as well as elevated serum TNF-alpha concentrations. Importantly insulin signaling was significantly attenuated in the liver of IRS-1-Tg mice, which may contribute to the glucose intolerance. Our results suggest that excess IRS-1 expression may not provide a beneficial impact on glucose homeostasis in vivo.