scholarly journals Reduced insulin clearance and lower insulin-degrading enzyme expression in the liver might contribute to the thrifty phenotype of protein-restricted mice

2014 ◽  
Vol 112 (6) ◽  
pp. 900-907 ◽  
Author(s):  
Luiz F. Rezende ◽  
Rafael L. Camargo ◽  
Renato C. S. Branco ◽  
Ana P. G. Cappelli ◽  
Antonio C. Boschero ◽  
...  
Keyword(s):  
Insulin Secretion ◽  
Protein Kinase ◽  
Glucose Tolerance ◽  
Glucose Homeostasis ◽  
Insulin Clearance ◽  
Protein Diet ◽  
Restricted Diet ◽  
Insulin Degrading Enzyme ◽  
Degrading Enzyme ◽  
Thrifty Phenotype

Nutrient restriction during the early stages of life usually leads to alterations in glucose homeostasis, mainly insulin secretion and sensitivity, increasing the risk of metabolic disorders in adulthood. Despite growing evidence regarding the importance of insulin clearance during glucose homeostasis in health and disease, no information exists about this process in malnourished animals. Thus, in the present study, we aimed to determine the effect of a nutrient-restricted diet on insulin clearance using a model in which 30-d-old C57BL/6 mice were exposed to a protein-restricted diet for 14 weeks. After this period, we evaluated many metabolic variables and extracted pancreatic islet, liver, gastrocnemius muscle (GCK) and white adipose tissue samples from the control (normal-protein diet) and restricted (low-protein diet, LP) mice. Insulin concentrations were determined using RIA and protein expression and phosphorylation by Western blot analysis. The LP mice exhibited lower body weight, glycaemia, and insulinaemia, increased glucose tolerance and altered insulin dynamics after the glucose challenge. The improved glucose tolerance could partially be explained by an increase in insulin sensitivity through the phosphorylation of the insulin receptor/protein kinase B and AMP-activated protein kinase/acetyl-CoA carboxylase in the liver, whereas the changes in insulin dynamics could be attributed to reduced insulin secretion coupled with reduced insulin clearance and lower insulin-degrading enzyme (IDE) expression in the liver and GCK. In summary, protein-restricted mice not only produce and secrete less insulin, but also remove and degrade less insulin. This phenomenon has the double benefit of sparing insulin while prolonging and potentiating its effects, probably due to the lower expression of IDE in the liver, possibly with long-term consequences.

scholarly journals Vagotomy Reduces Insulin Clearance in Obese Mice Programmed by Low-Protein Diet in the Adolescence

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Camila Lubaczeuski ◽  
Luciana Mateus Gonçalves ◽  
Jean Franciesco Vettorazzi ◽  
Mirian Ayumi Kurauti ◽  
Junia Carolina Santos-Silva ◽  
...  
Keyword(s):  
Insulin Secretion ◽  
Insulin Sensitivity ◽  
Glucose Tolerance ◽  
High Fat Diet ◽  
Insulin Clearance ◽  
Protein Diet ◽  
Low Protein Diet ◽  
High Fat ◽  
Insulin Degrading Enzyme ◽  
Low Protein

The aim of this study was to investigate the effect of subdiaphragmatic vagotomy on insulin sensitivity, secretion, and degradation in metabolic programmed mice, induced by a low-protein diet early in life, followed by exposure to a high-fat diet in adulthood. Weaned 30-day-old C57Bl/6 mice were submitted to a low-protein diet (6% protein). After 4 weeks, the mice were distributed into three groups: LP group, which continued receiving a low-protein diet; LP + HF group, which started to receive a high-fat diet; and LP + HFvag group, which underwent vagotomy and also was kept at a high-fat diet. Glucose-stimulated insulin secretion (GSIS) in isolated islets, ipGTT, ipITT, in vivo insulin clearance, and liver expression of the insulin-degrading enzyme (IDE) was accessed. Vagotomy improved glucose tolerance and reduced insulin secretion but did not alter adiposity and insulin sensitivity in the LP + HFvag, compared with the LP + HF group. Improvement in glucose tolerance was accompanied by increased insulinemia, probably due to a diminished insulin clearance, as judged by the lower C-peptide : insulin ratio, during the ipGTT. Finally, vagotomy also reduced liver IDE expression in this group. In conclusion, when submitted to vagotomy, the metabolic programmed mice showed improved glucose tolerance, associated with an increase of plasma insulin concentration as a result of insulin clearance reduction, a phenomenon probably due to diminished liver IDE expression.

scholarly journals Cafeteria diet inhibits insulin clearance by reduced insulin-degrading enzyme expression and mRNA splicing

2013 ◽  
Vol 219 (2) ◽  
pp. 173-182 ◽  
Author(s):  
P Brandimarti ◽  
J M Costa-Júnior ◽  
S M Ferreira ◽  
A O Protzek ◽  
G J Santos ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Insulin Secretion ◽  
Alternative Splicing ◽  
Insulin Sensitivity ◽  
Glucose Homeostasis ◽  
Insulin Clearance ◽  
Cafeteria Diet ◽  
Mrna Levels ◽  
Insulin Degrading Enzyme ◽  
Diet Induced Obesity

Insulin clearance plays a major role in glucose homeostasis and insulin sensitivity in physiological and/or pathological conditions, such as obesity-induced type 2 diabetes as well as diet-induced obesity. The aim of the present work was to evaluate cafeteria diet-induced obesity-induced changes in insulin clearance and to explain the mechanisms underlying these possible changes. Female Swiss mice were fed either a standard chow diet (CTL) or a cafeteria diet (CAF) for 8 weeks, after which we performed glucose tolerance tests, insulin tolerance tests, insulin dynamics, and insulin clearance tests. We then isolated pancreatic islets for ex vivo glucose-stimulated insulin secretion as well as liver, gastrocnemius, visceral adipose tissue, and hypothalamus for subsequent protein analysis by western blot and determination of mRNA levels by real-time RT-PCR. The cafeteria diet induced insulin resistance, glucose intolerance, and increased insulin secretion and total insulin content. More importantly, mice that were fed a cafeteria diet demonstrated reduced insulin clearance and decay rate as well as reduced insulin-degrading enzyme (IDE) protein and mRNA levels in liver and skeletal muscle compared with the control animals. Furthermore, the cafeteria diet reduced IDE expression and alternative splicing in the liver and skeletal muscle of mice. In conclusion, a cafeteria diet impairs glucose homeostasis by reducing insulin sensitivity, but it also reduces insulin clearance by reducing IDE expression and alternative splicing in mouse liver; however, whether this mechanism contributes to the glucose intolerance or helps to ameliorate it remains unclear.

Vitamin E supplementation and caloric restriction promotes regulation of insulin secretion and glycemic homeostasis by different mechanisms in rats

2018 ◽  
Vol 96 (6) ◽  
pp. 777-785
Author(s):  
Paula R. Venturini ◽  
Bruna Fontana Thomazini ◽  
Camila Andréa Oliveira ◽  
Armindo A. Alves ◽  
Thaís Furtado Camargo ◽  
...  
Keyword(s):  
Insulin Secretion ◽  
Vitamin E ◽  
Insulin Receptor ◽  
Caloric Restriction ◽  
Glucose Homeostasis ◽  
Control Group ◽  
Insulin Degrading Enzyme ◽  
Degrading Enzyme ◽  
Food Quantity ◽  
Vitamin E Supplementation

Vitamin E and caloric restriction have antioxidant effects in mammals. The aim of this study was to evaluate effects of vitamin E supplementation and caloric restriction upon insulin secretion and glucose homeostasis in rats. Male Wistar rats were distributed among the following groups: C, control group fed ad libitum; R, food quantity reduction of 40%; CV, control group supplemented with vitamin E [30 mg·kg–1·day–1]; and RV, food-restricted group supplemented with vitamin E. The experiments ran for 21 days. Glucose tolerance and insulin sensitivity was higher in the CV, R, and RV groups. Insulin secretion stimulated with different glucose concentrations was lower in the R and RV groups, compared with C and CV. In the presence of glucose and secretagogues, insulin secretion was higher in the CV group and was lower in the R and RV groups. An increase in insulin receptor occurred in the fat pad and muscle tissue of groups CV, R, and RV. Levels of hepatic insulin receptor and phospho-Akt protein were higher in groups R and RV, compared with C and CV, while muscle phospho-Akt was increased in the CV group. There was a reduction in hepatic RNA levels of the hepatocyte growth factor gene and insulin degrading enzyme in the R group, and increased levels of insulin degrading enzyme in the CV and RV groups. Thus, vitamin E supplementation and caloric restriction modulate insulin secretion by different mechanisms to maintain glucose homeostasis.

Antecedent protein restriction exacerbates development of impaired insulin action after high-fat feeding

1999 ◽  
Vol 276 (1) ◽  
pp. E85-E93 ◽  
Author(s):  
Mark J. Holness ◽  
Mary C. Sugden
Keyword(s):  
Insulin Secretion ◽  
Glucose Tolerance ◽  
Insulin Action ◽  
Protein Restriction ◽  
Protein Diet ◽  
Glucose Disposal ◽  
High Fat ◽  
Impaired Insulin ◽  
Impaired Insulin Action ◽  
Fat Feeding

The study investigated whether a persistent impairment of insulin secretion resulting from mild protein restriction predisposes to loss of glucoregulatory control and impaired insulin action after the subsequent imposition of the diabetogenic challenge of high-fat feeding. Offspring of dams provided with either control (20% protein) diet (C) or an isocaloric restricted (8%) protein diet (PR) were weaned onto the maintenance diet with which their mothers had been provided. At 20 wk of age, protein restriction enhanced glucose tolerance despite impaired insulin secretion and an augmented and sensitized lipolytic response to norepinephrine in adipocytes. C and PR rats were then transferred to a high-fat diet (HF, 19% protein, 22% lipid, 34% carbohydrate) and sampled after 8 wk. These groups are termed C-HF and PR-HF. Glucose tolerance was impaired in PR-HF, but not C-HF, rats. Insulin-stimulated glucose disposal rates were significantly lower (by 30%; P < 0.01) in the PR-HF group than in the C-HF group, and a specific impairment of antilipolytic response of insulin was unmasked in adipocytes from PR-HF, but not C-HF, rats. The study demonstrates that antecedent protein restriction accelerates and augments the development of impaired glucoregulation and insulin resistance after high-fat feeding.

ID: 79: INSULIN TREATMENT INCREASES MICROVESICULAR INSULIN-DEGRADING ENZYME IN DIABETES

2016 ◽  
Vol 64 (4) ◽  
pp. 926.2-927
Author(s):  
MV Purbaugh ◽  
CV Desouza ◽  
R Heineman ◽  
RG Bennett ◽  
FG Hamel
Keyword(s):  
Insulin Resistance ◽  
Western Blot ◽  
Insulin Treatment ◽  
Statistical Significance ◽  
Diabetic Group ◽  
Insulin Clearance ◽  
Diabetic Patients ◽  
Insulin Degrading Enzyme ◽  
Healthy Group ◽  
Degrading Enzyme

Insulin-degrading enzyme (IDE) in the blood may play a role in insulin clearance, thus decreased IDE activity could contribute to hyperinsulinemia and possibly type 2 diabetes mellitus (T2DM). We hypothesized that decreased IDE in plasma may be associated with obesity and/or T2DM. We recruited non-obese (BMI<30, no significant disease), obese (BMI>30) and diabetic (T2DM; ICD-9 code) patients and obtained fasting blood samples. Microvesicular (containing exosomes) and soluble fractions were isolated from plasma by ultracentrifugation Insulin degrading activity was assayed by trichloroacetic acid precipitation of 125I-iodoinsulin (TCA assay), while IDE protein was detected by Western blotting. Differences were analyzed by ANOVA with a Bonferroni posttest. There was no IDE present in the soluble fraction as confirmed by both the TCA assay and Western blot. IDE activity was present in the microvesicular fraction, and the Western blot intensity correlated significantly with activity (p=.01). However, there were no significant differences in IDE activity or protein levels among the 3 groups. We then conducted a post hoc analysis byseparating the non-obese and obese patients into two groups: a healthy group (HbA1c<6) and a pre-diabetic group (HbA1c of 6.0–6.4). We also separated the diabetic patients into two groups: a diabetic group and an insulin-treated group. Although there was no statistical difference in IDE activity among the healthy group, pre-diabetic and diabetic groups, the latter two groups showed a trend toward decreased IDE activity. Interestingly, in patients receiving insulin treatment, the effect of diabetes was reversed, with, increased microvesicular degrading activity compared to the pre-diabetic group (p<0.05) and the diabetic group (p<0.05). The increased IDE activity in the insulin-treated diabetics roughly correlated with the patient's insulin dose, but did not reach statistical significance (r2=.38; p=0.14). We saw no statistically significant correlations of degrading activity with a number of clinical parameters including: fasting glucose; triglycerides, LDL, HDL, age, eGFR, and HbA1c by linear regression. This shows that the microvesicular IDE is not affected by glucose or lipid control. We conclude: A) IDE is present in the blood, but does not significantly contribute to insulin clearance because the microvesicular fraction showed no insulin clearance unless they were first frozen and thawed. This freezing and thawing process most likely allowed the microvesicular membranes to rupture releasing the enzyme. B) enzymatically active IDE is associated with a fraction consistent with exosomes and may be decreased in pre-diabetes and diabetes; and C) insulin treatment increases microvesicular IDE. IDE in the exosomes may serve as a marker for the progression of the pre-diabetic and diabetic disease states independent of glucose control. One could speculate that inflammation and/or insulin resistance result in a decrease of vesicular IDE activity and that insulin treatment reverses this through its anti-inflammatory properties, or by overcoming insulin resistance and increasing insulin signaling.

scholarly journals GPR119 Regulates Murine Glucose Homeostasis Through Incretin Receptor-Dependent and Independent Mechanisms

Endocrinology ◽  
2010 ◽  
Vol 152 (2) ◽  
pp. 374-383 ◽  
Author(s):  
Grace Flock ◽  
Dianne Holland ◽  
Yutaka Seino ◽  
Daniel J. Drucker
Keyword(s):  
Insulin Secretion ◽  
Gastric Emptying ◽  
Glucose Tolerance ◽  
Glucose Homeostasis ◽  
Peptide Yy ◽  
Cell Receptor ◽  
Dependent Manner ◽  
Glucagon Like Peptide 1

Abstract G protein-coupled receptor 119 (GPR119) was originally identified as a β-cell receptor. However, GPR119 activation also promotes incretin secretion and enhances peptide YY action. We examined whether GPR119-dependent control of glucose homeostasis requires preservation of peptidergic pathways in vivo. Insulin secretion was assessed directly in islets, and glucoregulation was examined in wild-type (WT), single incretin receptor (IR) and dual IR knockout (DIRKO) mice. Experimental endpoints included plasma glucose, insulin, glucagon, glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic peptide (GIP), and peptide YY. Gastric emptying was assessed in WT, Glp1r−/−, DIRKO, Glp2r−/−, and GPR119−/− mice treated with the GPR119 agonist AR231453. AR231453 stimulated insulin secretion from WT and DIRKO islets in a glucose-dependent manner, improved glucose homeostasis, and augmented plasma levels of GLP-1, GIP, and insulin in WT and Gipr−/−mice. In contrast, although AR231453 increased levels of GLP-1, GIP, and insulin, it failed to lower glucose in Glp1r−/− and DIRKO mice. Furthermore, AR231453 did not improve ip glucose tolerance and had no effect on insulin action in WT and DIRKO mice. Acute GPR119 activation with AR231453 inhibited gastric emptying in Glp1r−/−, DIRKO, Glp2r−/−, and in WT mice independent of the Y2 receptor (Y2R); however, AR231453 did not control gastric emptying in GPR119−/− mice. Our findings demonstrate that GPR119 activation directly stimulates insulin secretion from islets in vitro, yet requires intact IR signaling and enteral glucose exposure for optimal control of glucose tolerance in vivo. In contrast, AR231453 inhibits gastric emptying independent of incretin, Y2R, or Glp2 receptors through GPR119-dependent pathways. Hence, GPR119 engages multiple complementary pathways for control of glucose homeostasis.

scholarly journals Acute Exercise Improves Insulin Clearance and Increases the Expression of Insulin-Degrading Enzyme in the Liver and Skeletal Muscle of Swiss Mice

PLoS ONE ◽  
2016 ◽  
Vol 11 (7) ◽  
pp. e0160239 ◽  
Author(s):  
Mirian A. Kurauti ◽  
Ricardo Freitas-Dias ◽  
Sandra M. Ferreira ◽  
Jean F. Vettorazzi ◽  
Tarlliza R. Nardelli ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Acute Exercise ◽  
Insulin Clearance ◽  
Insulin Degrading Enzyme ◽  
Degrading Enzyme ◽  
Swiss Mice

scholarly journals Bile acid TUDCA improves insulin clearance by increasing the expression of insulin-degrading enzyme in the liver of obese mice

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Jean Franciesco Vettorazzi ◽  
Mirian Ayumi Kurauti ◽  
Gabriela Moreira Soares ◽  
Patricia Cristine Borck ◽  
Sandra Mara Ferreira ◽  
...  
Keyword(s):  
Bile Acid ◽  
Insulin Clearance ◽  
Obese Mice ◽  
Insulin Degrading Enzyme ◽  
Degrading Enzyme

scholarly journals Hepatic Insulin Clearance: Mechanism and Physiology

Physiology ◽  
2019 ◽  
Vol 34 (3) ◽  
pp. 198-215 ◽  
Author(s):  
Sonia M. Najjar ◽  
Germán Perdomo
Keyword(s):  
Insulin Resistance ◽  
Insulin Secretion ◽  
Insulin Receptor ◽  
Hepatic Steatosis ◽  
Insulin Clearance ◽  
Hepatic Insulin Resistance ◽  
Insulin Degrading Enzyme ◽  
Insulin Receptor Tyrosine Kinase ◽  
Impaired Insulin ◽  
Hepatic Insulin Clearance

Upon its secretion from pancreatic β-cells, insulin reaches the liver through the portal circulation to exert its action and eventually undergo clearance in the hepatocytes. In addition to insulin secretion, hepatic insulin clearance regulates the homeostatic level of insulin that is required to reach peripheral insulin target tissues to elicit proper insulin action. Receptor-mediated insulin uptake followed by its degradation constitutes the basic mechanism of insulin clearance. Upon its phosphorylation by the insulin receptor tyrosine kinase, carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) takes part in the insulin-insulin receptor complex to increase the rate of its endocytosis and targeting to the degradation pathways. This review summarizes how this process is regulated and how it is associated with insulin-degrading enzyme in the liver. It also discusses the physiological implications of impaired hepatic insulin clearance: Whereas reduced insulin clearance cooperates with increased insulin secretion to compensate for insulin resistance, it can also cause hepatic insulin resistance. Because chronic hyperinsulinemia stimulates hepatic de novo lipogenesis, impaired insulin clearance also causes hepatic steatosis. Thus impaired insulin clearance can underlie the link between hepatic insulin resistance and hepatic steatosis. Delineating these regulatory pathways should lead to building more effective therapeutic strategies against metabolic syndrome.

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