scholarly journals USP1 deubiquitinates protein kinase Akt to inhibit PI3K-Akt-FoxO signaling

2019 ◽  
Author(s):  
Dana Goldbraikh ◽  
Danielle Neufeld ◽  
Yara Mutlak-Eid ◽  
Inbal Lasry ◽  
Anna Parnis ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Insulin Resistance ◽  
Protein Synthesis ◽  
Protein Kinase ◽  
Glucose Uptake ◽  
Tuberous Sclerosis Complex ◽  
Polyubiquitin Chains ◽  
Protein Levels ◽  
Screening Platform ◽  
Protein Kinase Akt

ABSTRACTPI3K-Akt-FoxO-mTOR signaling is the central pathway controlling growth and metabolism in all cells. Activation of this pathway requires ubiquitination of Akt prior to its activation by phosphorylation. Here, we found that the deubiquitinating (DUB) enzyme USP1 removes K63-linked polyubiquitin chains on Akt to sustain PI3K-Akt-FoxO signaling low during prolonged starvation. DUB screening platform identified USP1 as a direct DUB for Akt, and USP1 depletion in atrophying muscle increased Akt ubiquitination, PI3K-Akt-FoxO signaling, and glucose uptake during fasting. Co-immunoprecipitation and mass spectrometry identified Disabled-2 (Dab2) and the tuberous sclerosis complex TSC1/TSC2 as USP1 bound proteins. During starvation, Dab2 was essential for Akt recruitment to USP1/UAF1 complex, and for PI3K-Akt-FoxO inhibition. Additionally, to maintain its own protein levels high, USP1 limits TSC1 levels to sustain mTOR-mediated basal protein synthesis rates. This USP1-mediated suppression of PI3K-Akt-FoxO signaling probably contributes to insulin resistance in catabolic diseases and perhaps to malignancies seen with USP1 mutations.

scholarly journals Muscle Adaptation to Short-Term Fasting in Healthy Lean Humans

2008 ◽  
Vol 93 (7) ◽  
pp. 2900-2903 ◽  
Author(s):  
Maarten R. Soeters ◽  
Hans P. Sauerwein ◽  
Peter F. Dubbelhuis ◽  
Johanna E. Groener ◽  
Mariëtte T. Ackermans ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Protein Kinase ◽  
Glucose Uptake ◽  
Protein Kinase B ◽  
Muscle Adaptation ◽  
Short Term ◽  
Akt Phosphorylation ◽  
Induce Insulin Resistance ◽  
Before And After ◽  
Muscle Biopsies

Abstract Context: It has been demonstrated repeatedly that short-term fasting induces insulin resistance, although the exact mechanism in humans is unknown to date. Intramyocellular sphingolipids (i.e. ceramide) have been suggested to induce insulin resistance by interfering with the insulin signaling cascade in obesity. Objective: Our objective was to study peripheral insulin sensitivity together with muscle ceramide concentrations and protein kinase B/AKT phosphorylation after short-term fasting. Main Outcome Measures and Design: After 14- and 62-h fasting, glucose fluxes were measured before and after a hyperinsulinemic euglycemic clamp. Muscle biopsies were performed in the basal state and during the clamp to assess muscle ceramide and protein kinase B/AKT. Results: Insulin-mediated peripheral glucose uptake was significantly lower after 62-h fasting compared with 14-h fasting. Intramuscular ceramide concentrations tended to increase during fasting. During the clamp the phosphorylation of protein kinase B/AKT at serine473 in proportion to the total amount of protein kinase B/AKT was significantly lower. Muscle ceramide did not correlate with plasma free fatty acids. Conclusions: Fasting for 62 h decreases insulin-mediated peripheral glucose uptake with lower phosphorylation of AKT at serine473. AKT may play a regulatory role in fasting-induced insulin resistance. Whether the decrease in AKT can be attributed to the trend to higher muscle ceramide remains unanswered.

scholarly journals Interleukin-1β-Induced Insulin Resistance in Adipocytes through Down-Regulation of Insulin Receptor Substrate-1 Expression

Endocrinology ◽  
2007 ◽  
Vol 148 (1) ◽  
pp. 241-251 ◽  
Author(s):  
Jennifer Jager ◽  
Thierry Grémeaux ◽  
Mireille Cormont ◽  
Yannick Le Marchand-Brustel ◽  
Jean-François Tanti
Keyword(s):  
Insulin Resistance ◽  
Protein Kinase ◽  
Insulin Receptor ◽  
Glucose Uptake ◽  
Insulin Signaling ◽  
Protein Kinase B ◽  
Transcriptional Level ◽  
Insulin Receptor Substrate ◽  
Down Regulation ◽  
Glut 4

Inflammation is associated with obesity and insulin resistance. Proinflammatory cytokines produced by adipose tissue in obesity could alter insulin signaling and action. Recent studies have shown a relationship between IL-1β level and metabolic syndrome or type 2 diabetes. However, the ability of IL-1β to alter insulin signaling and action remains to be explored. We demonstrated that IL-1β slightly increased Glut 1 translocation and basal glucose uptake in 3T3-L1 adipocytes. Importantly, we found that prolonged IL-1β treatment reduced the insulin-induced glucose uptake, whereas an acute treatment had no effect. Chronic treatment with IL-1β slightly decreased the expression of Glut 4 and markedly inhibited its translocation to the plasma membrane in response to insulin. This inhibitory effect was due to a decrease in the amount of insulin receptor substrate (IRS)-1 but not IRS-2 expression in both 3T3-L1 and human adipocytes. The decrease in IRS-1 amount resulted in a reduction in its tyrosine phosphorylation and the alteration of insulin-induced protein kinase B activation and AS160 phosphorylation. Pharmacological inhibition of ERK totally inhibited IL-1β-induced down-regulation of IRS-1 mRNA. Moreover, IRS-1 protein expression and insulin-induced protein kinase B activation, AS160 phosphorylation, and Glut 4 translocation were partially recovered after treatment with the ERK inhibitor. These results demonstrate that IL-1β reduces IRS-1 expression at a transcriptional level through a mechanism that is ERK dependent and at a posttranscriptional level independently of ERK activation. By targeting IRS-1, IL-1β is capable of impairing insulin signaling and action, and could thus participate in concert with other cytokines, in the development of insulin resistance in adipocytes.

scholarly journals Resveratrol Ameliorates High-Fat-Diet-Induced Abnormalities in Hepatic Glucose Metabolism in Mice via the AMP-Activated Protein Kinase Pathway

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Caiping Lu ◽  
Hanying Xing ◽  
Linquan Yang ◽  
Kaiting Chen ◽  
Linyi Shu ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Protein Kinase ◽  
Glucose Metabolism ◽  
Glucose Uptake ◽  
High Fat Diet ◽  
Blood Glucose Concentration ◽  
Glycogen Synthesis ◽  
Liver Fat ◽  
High Fat ◽  
Amp Activated Protein Kinase

Diabetes mellitus is highly prevalent worldwide. High-fat-diet (HFD) consumption can lead to liver fat accumulation, impair hepatic glycometabolism, and cause insulin resistance and the development of diabetes. Resveratrol has been shown to improve the blood glucose concentration of diabetic mice, but its effect on the abnormal hepatic glycometabolism induced by HFD-feeding and the mechanism involved are unknown. In this study, we determined the effects of resveratrol on the insulin resistance of high-fat-diet-fed mice and a hepatocyte model by measuring serum biochemical indexes, key indicators of glycometabolism, glucose uptake, and glycogen synthesis in hepatocytes. We found that resveratrol treatment significantly ameliorated the HFD-induced abnormalities in glucose metabolism in mice, increased glucose absorption and glycogen synthesis, downregulated protein phosphatase 2A (PP2A) and activated Ca2+/CaM-dependent protein kinase kinase β (CaMKKβ), and increased the phosphorylation of AMP-activated protein kinase (AMPK). In insulin-resistant HepG2 cells, the administration of a PP2A activator or CaMKKβ inhibitor attenuated the effects of resveratrol, but the administration of an AMPK inhibitor abolished the effects of resveratrol. Resveratrol significantly ameliorates abnormalities in glycometabolism induced by HFD-feeding and increases glucose uptake and glycogen synthesis in hepatocytes. These effects are mediated through the activation of AMPK by PP2A and CaMKKβ.

scholarly journals Protein kinase‐D1 overexpression in mice prevents lipid‐induced insulin resistance and cardiomyopathy by upregulation of glucose uptake

2011 ◽  
Vol 25 (S1) ◽  
Author(s):  
Ellen Dirkx ◽  
Robert W. Schwenk ◽  
Laura KM Steinbusch ◽  
Nicole Hoebers ◽  
Ben J Janssen ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Protein Kinase ◽  
Glucose Uptake ◽  
Protein Kinase D1

Abstract 543: Myeloperoxidase Induces Endothelial Dysfunction via Activation of Calpain

2017 ◽  
Vol 37 (suppl_1) ◽  
Author(s):  
Zienab Etwebi ◽  
Gavin Landesberg ◽  
Rosario Scalia
Keyword(s):  
Insulin Resistance ◽  
Protein Kinase ◽  
Endothelial Dysfunction ◽  
Mouse Lung ◽  
Calpain Inhibitor ◽  
Adhesion Assay ◽  
Primary Role ◽  
Protein Levels ◽  
Ampk Phosphorylation ◽  
Enos Phosphorylation

Myeloperoxidase (MPO) is a peroxidase enzyme secreted by activated leukocytes, which has been associated with endothelial dysfunction and insulin resistance. The calcium dependent protease calpain has also been linked to vascular disease in insulin resistance and type 2 diabetes. Accordingly, we tested the hypothesis that endothelial expressed calpains play a role in MPO-induced endothelial dysfunction and vascular inflammation. Mouse lung microvascular endothelial cells (MMVEC) were stimulated with 10 nM MPO for 30, 60, 120, 180, and 240 minutes. Expression levels of Vascular Cell Adhesion Molecule 1 (VCAM-1), 5’ AMP Activated Protein Kinase (AMPK), Protein Kinase B (PKB) (Akt), endothelial Nitric Oxide (eNOS) phosphorylation at serine 1177 (Se1177), Protein Phosphatase 2 (PP2A), and calpains were measured by immunoblot analyses. MPO time dependently activated μ-calpain (P<0.0001 vs control) but not m-calpain. MPO also significantly increased PP2A protein levels (P<0.001), decreased AMPK phosphorylation (P<0.01), AKT phosphorylation (P<0.05), and eNOS phosphorylation at (Se1177) (P<0.01), while significantly increased VCAM-1 protein levels (P<0.01). Pretreatment of MMVECs with the selective calpain inhibitor ZLLal (100 μM) prevent MPO-induced calpain activation (P<0.0001 vs MPO alone). Inhibition of calpain activity also preserved AMPK phosphorylation, eNOS phosphorylation, and PP2A levels, in the face of MPO (P<0.001 versus MPO alone). Calpain inhibition also prevented upregulation of VCAM-1. Using an ex vivo leukocyte adhesion assay we also found leukocytes failed to adhere to the vascular endothelium of MPO treated aortas isolated from μ-calpain deficient mice (p<0.001 versus aortas isolated from WT mice). Taken together, our data first demonstrate a primary role for μ-calpain in endothelial dysfunction induced by leukocyte derived MPO.

scholarly journals Treatment with TNF-α and IFN-γ alters the activation of SER/THR protein kinases and the metabolic response to IGF-I in mouse c2c12 myogenic cells

2010 ◽  
Vol 15 (1) ◽  
Author(s):  
Katarzyna Grzelkowska-Kowalczyk ◽  
Wioletta Wieteska-Skrzeczyńska
Keyword(s):  
Protein Synthesis ◽  
Protein Kinase ◽  
Glucose Uptake ◽  
Fold Increase ◽  
C2c12 Myotubes ◽  
Myogenic Cells ◽  
Tnf Α ◽  
Igf I ◽  
Ifn Γ ◽  
C2c12 Myogenic Cells

AbstractThe aim of this study was to compare the effects of TNF-α, IL-1β and IFN-γ on the activation of protein kinase B (PKB), p70S6k, mitogen-activated protein kinase (MAPK) and p90rsk, and on IGF-I-stimulated glucose uptake and protein synthesis in mouse C2C12 myotubes. 100 nmol/l IGF-I stimulated glucose uptake in C2C12 myotubes by 198.1% and 10 ng/ml TNF-α abolished this effect. Glucose uptake in cells differentiated in the presence of 10 ng/ml IFN-γ increased by 167.2% but did not undergo significant further modification upon the addition of IGF-I. IGF-I increased the rate of protein synthesis by 249.8%. Neither TNF-α nor IFN-γ influenced basal protein synthesis, but both cytokines prevented the IGF-I effect. 10 ng/ml IL-1β did not modify either the basal or IGF-I-dependent glucose uptake and protein synthesis. With the exception of TNF-α causing an 18% decrease in the level of PKB protein, the cellular levels of PKB, p70S6k, p42MAPK, p44MAPK and p90rsk were not affected by the cytokines. IGF-I caused the phosphorylation of PKB (an approximate 8-fold increase above the basal value after 40 min of IGF-I treatment), p42MAPK (a 2.81-fold increase after 50 min), and the activation of p70S6k and p90rsk, manifesting as gel mobility retardation. In cells differentiated in the presence of TNF-α or IFN-γ, this IGF-I-mediated PKB and p70S6k phosphorylation was significantly diminished, and the increase in p42MAPK and p90rsk phosphorylation was prevented. The basal p42MAPK phosphorylation in C2C12 cells treated with IFN-γ was high and comparable with the activation of this kinase by IGF-I. Pretreatment of myogenic cells with IL-1β did not modify the IGF-I-stimulated phosphorylation of PKB, p70S6k, p42MAPK and p90rsk. In conclusion: i) TNF-α and IFN-γ, but not IL-1β, if present in the extracellular environment during C2C12 myoblast differentiation, prevent the stimulatory action of IGF-I on protein synthesis. ii) TNF-α- and IFN-γ-induced IGF-I resistance of protein synthesis could be associated with the decreased phosphorylation of PKB and p70S6k. iii) The activation of glucose uptake in C2C12 myogenic cells treated with IFN-γ is PKB independent. iv) The similar effects of TNF-α and IFN-γ on the signalling and action of IGF-I on protein synthesis in myogenic cells could suggest the involvement of both of these cytokines in protein loss in skeletal muscle.

scholarly journals Dexamethasone impairs insulin signalling and glucose transport by depletion of insulin receptor substrate-1, phosphatidylinositol 3-kinase and protein kinase B in primary cultured rat adipocytes

2002 ◽  
pp. 419-429 ◽  
Author(s):  
J Buren ◽  
HX Liu ◽  
J Jensen ◽  
JW Eriksson
Keyword(s):  
Insulin Resistance ◽  
Protein Kinase ◽  
Glucose Uptake ◽  
Glucose Transport ◽  
Insulin Signalling ◽  
Protein Kinase B ◽  
Insulin Binding ◽  
Insulin Receptor Substrate ◽  
Phosphatidylinositol 3 Kinase ◽  
Rat Adipocytes

OBJECTIVE: Glucocorticoid excess leads to insulin resistance. This study explores the effects of glucocorticoids on the glucose transport system and insulin signalling in rat adipocytes. The interaction between glucocorticoids and high levels of insulin and glucose is also addressed. DESIGN AND METHODS: Isolated rat adipocytes were cultured for 24 h at different glucose concentrations (5 and 15 mmol/l) with or without the glucocorticoid analogue dexamethasone (0.3 micromol/l) and insulin (10(4) microU/ml). After the culture period, the cells were washed and then basal and insulin-stimulated glucose uptake, insulin binding and lipolysis as well as cellular content of insulin signalling proteins (insulin receptor substrate-1 (IRS-1), IRS-2, phosphatidylinositol 3-kinase (PI3-K) and protein kinase B (PKB)) and glucose transporter isoform GLUT4 were measured. RESULTS: Dexamethasone in the medium markedly decreased both basal and insulin-stimulated glucose uptake at both 5 and 15 mmol/l glucose (by approximately 40-50%, P<0.001 and P<0.05 respectively). Combined long-term treatment with insulin and dexamethasone exerted additive effects in decreasing basal, and to a lesser extent insulin-stimulated, glucose uptake capacity (P<0.05) compared with dexamethasone alone, but this was seen only at high glucose (15 mmol/l). Insulin binding was decreased (by approximately 40%, P<0.05) in dexamethasone-treated cells independently of surrounding glucose concentration. Following dexamethasone treatment a approximately 75% decrease (P<0.001) in IRS-1 expression and an increase in IRS-2 (by approximately 150%, P<0.001) was shown. Dexamethasone also induced a subtle decrease in PI3-K (by approximately 20%, P<0.01) and a substantial decrease in PKB content (by approximately 45%, P<0.001). Insulin-stimulated PKB phosphorylation was decreased (by approximately 40%, P<0.01) in dexamethasone-treated cells. Dexamethasone did not alter the amount of total cellular membrane-associated GLUT4 protein. The effects of dexamethasone per se on glucose transport and insulin signalling proteins were mainly unaffected by the surrounding glucose and insulin levels. Dexamethasone increased the basal lipolytic rate (approximately 4-fold, P<0.05), but did not alter the antilipolytic effect of insulin. CONCLUSIONS: These results suggest that glucocorticoids, independently of the surrounding glucose and insulin concentration, impair glucose transport capacity in fat cells. This is not due to alterations in GLUT4 abundance. Instead dexamethasone-induced insulin resistance may be mediated via reduced cellular content of IRS-1 and PKB accompanied by a parallel reduction in insulin-stimulated activation of PKB.

scholarly journals Leukocyte antigen-related inhibition attenuates palmitate-induced insulin resistance in muscle cells

2012 ◽  
Vol 215 (1) ◽  
pp. 71-77 ◽  
Author(s):  
Sattar Gorgani-Firuzjaee ◽  
Salar Bakhtiyari ◽  
Abolfazl Golestani ◽  
Reza Meshkani
Keyword(s):  
Insulin Resistance ◽  
Glucose Uptake ◽  
Cell Line ◽  
C2c12 Cell ◽  
Muscle Cells ◽  
C2c12 Cells ◽  
Stable Cell Line ◽  
Protein Levels ◽  
Induce Insulin Resistance ◽  
And Control

Palmitate has been shown to induce insulin resistance in skeletal muscle cells. The aim of this study was to investigate the role of the leukocyte common antigen-related (LAR) gene in palmitate-induced insulin resistance in C2C12 cells. A stable C2C12 cell line was generated using LAR short hairpin RNA. The levels of LAR protein and phosphorylation of insulin receptor substrate-1 (IRS1) and Akt were detected by western blot analysis. 2-Deoxyglucose uptake was measured in LAR knockdown and control cells using d-[2-3H]glucose. LAR protein level was decreased by 65% in the stable cell line compared with the control cells. Palmitate (0.5 mM) significantly induced LAR mRNA (65%) and protein levels (40%) in myotubes compared with untreated cells. Palmitate significantly reduced insulin-stimulated glucose uptake in both the control and LAR knockdown cells by 33 and 51% respectively. However, LAR depletion improved insulin-stimulated glucose uptake in myotubes treated with palmitate. Furthermore, the inhibition of LAR prevented palmitate-induced decreases in phosphorylation of IRS1Tyr632 and AktSer473 in C2C12 cells. In conclusion, these results reveal that palmitate induces LAR expression in C2C12 cells. We also provided evidence that the inhibition of LAR attenuates palmitate-induced insulin resistance in myotubes.

DAG accumulation from saturated fatty acids desensitizes insulin stimulation of glucose uptake in muscle cells

2001 ◽  
Vol 280 (2) ◽  
pp. E229-E237 ◽  
Author(s):  
Eulàlia Montell ◽  
Marco Turini ◽  
Mario Marotta ◽  
Matthew Roberts ◽  
Véronique Noé ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Fatty Acids ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Glucose Uptake ◽  
Insulin Response ◽  
Insulin Stimulation ◽  
Kinase C ◽  
Basal Glucose Uptake ◽  
Stimulation Of

The increased availability of saturated lipids has been correlated with development of insulin resistance, although the basis for this impairment is not defined. This work examined the interaction of saturated and unsaturated fatty acids (FA) with insulin stimulation of glucose uptake and its relation to the FA incorporation into different lipid pools in cultured human muscle. It is shown that basal or insulin-stimulated 2-deoxyglucose uptake was unaltered in cells preincubated with oleate, whereas basal glucose uptake was increased and insulin response was impaired in palmitate- and stearate-loaded cells. Analysis of the incorporation of FA into different lipid pools showed that palmitate, stearate, and oleate were similarly incorporated into phospholipids (PL) and did not modify the FA profile. In contrast, differences were observed in the total incorporation of FA into triacylglycerides (TAG): unsaturated FA were readily diverted toward TAG, whereas saturated FA could accumulate as diacylglycerol (DAG). Treatment with palmitate increased the activity of membrane-associated protein kinase C, whereas oleate had no effect. Mixture of palmitate with oleate diverted the saturated FA toward TAG and abolished its effect on glucose uptake. In conclusion, our data indicate that saturated FA-promoted changes in basal glucose uptake and insulin response were not correlated to a modification of the FA profile in PL or TAG accumulation. In contrast, these changes were related to saturated FA being accumulated as DAG and activating protein kinase C. Therefore, our results suggest that accumulation of DAG may be a molecular link between an increased availability of saturated FA and the induction of insulin resistance.

Statin reverses reduction of adiponectin receptor expression in infarcted heart and in TNF-α-treated cardiomyocytes in association with improved glucose uptake

2007 ◽  
Vol 293 (6) ◽  
pp. H3490-H3497 ◽  
Author(s):  
Yukio Saito ◽  
Daisuke Fujioka ◽  
Ken-ichi Kawabata ◽  
Tsuyoshi Kobayashi ◽  
Toshiaki Yano ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Glucose Uptake ◽  
Cultured Cells ◽  
Myocardial Dysfunction ◽  
Statin Treatment ◽  
Receptor Expression ◽  
Expression Levels ◽  
Protein Levels ◽  
Tnf Α ◽  
Cultured Cardiomyocytes

Statin treatment improves insulin resistance in skeletal muscle. Thus this study assessed whether statin may affect the myocardial expression levels of AdipoR1 and AdipoR2, receptors of adiponectin that enhance insulin sensitivity, and whether statin may improve insulin resistance in cardiomyocytes. Myocardial infarction (MI) was created by the ligation of the left coronary artery in male mice. Expression levels of mRNA and protein levels of AdipoR1 but not of AdipoR2 were significantly decreased in the remote area as well as in the healed infarcted area in the left ventricles 4 wk after MI. Oral administration of pravastatin (50 mg·kg−1·day−1 for 4 wk after MI) reversed the decrease in myocardial expression levels of AdipoR1 independently of changes in serum lipid profiles and insulin levels. With the use of cultured cardiomyocytes, incubation with tumor necrosis factor (TNF)-α, a mediator of postinfarction myocardial dysfunction, inhibited AdipoR1 mRNA and protein expression levels. Coincubation of the cells with pravastatin reversed the inhibitory effects of TNF-α on AdipoR1 expression. In parallel, pravastatin reversed the TNF-α-induced decrease in globular adiponectin-induced 2-deoxy-d-[3H]glucose uptake in insulin-treated cultured cells. Moreover, this effect of pravastatin was inhibited by the suppression of AdipoR1 expression by small-interfering RNA specific for AdipoR1. Incubation with H2O2 reduced AdipoR1 expression in cultured cardiomyocytes that were attenuated by N-acetyl-l-cysteine or pravastatin. Pravastatin suppressed TNF-α-induced intracellular oxidants in cultured cardiomyocytes. In conclusion, pravastatin reversed the reduction of AdipoR1 expression in postinfarction mouse myocardium and in TNF-α-treated cardiomyocytes partly through an antioxidative mechanism in association with improved glucose uptake.

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