Catalytic site inhibition of insulin-degrading enzyme by a small molecule induces glucose intolerance in mice.
Ontology highlight
ABSTRACT:
SUBMITTER: Deprez-Poulain R
PROVIDER: S-EPMC4580987 | biostudies-literature |
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:The role of insulin-degrading enzyme (IDE), a metalloprotease with high affinity for insulin, in insulin clearance remains poorly understood.ObjectiveThis study aimed to clarify whether IDE is a major mediator of insulin clearance, and to define its role in the etiology of hepatic insulin resistance.MethodsWe generated mice with liver-specific deletion of Ide (L-IDE-KO) and assessed insulin clearance and action.ResultsL-IDE-KO mice exhibited higher (~20%) fasting and non-fasting plasma glucose levels, glucose intolerance and insulin resistance. This phenotype was associated with ~30% lower plasma membrane insulin receptor levels in liver, as well as ~55% reduction in insulin-stimulated phosphorylation of the insulin receptor, and its downstream signaling molecules, AKT1 and AKT2 (reduced by ~40%). In addition, FoxO1 was aberrantly distributed in cellular nuclei, in parallel with up-regulation of the gluconeogenic genes Pck1 and G6pc. Surprisingly, L-IDE-KO mice showed similar plasma insulin levels and hepatic insulin clearance as control mice, despite reduced phosphorylation of the carcinoembryonic antigen-related cell adhesion molecule 1, which upon its insulin-stimulated phosphorylation, promotes receptor-mediated insulin uptake to be degraded.ConclusionIDE is not a rate-limiting regulator of plasma insulin levels in vivo.
| S-EPMC6185772 | biostudies-literature
Project description:Insulin-degrading enzyme (IDE) (insulysin) is a zinc metallopeptidase that metabolizes several bioactive peptides, including insulin and the amyloid β peptide. IDE is an unusual metallopeptidase in that it is allosterically activated by both small peptides and anions, such as ATP. Here, we report that the ATP-binding site is located on a portion of the substrate binding chamber wall arising largely from domain 4 of the four-domain IDE. Two variants having residues in this site mutated, IDEK898A,K899A,S901A and IDER429S, both show greatly decreased activation by the polyphosphate anions ATP and PPPi. IDEK898A,K899A,S901A is also deficient in activation by small peptides, suggesting a possible mechanistic link between the two types of allosteric activation. Sodium chloride at high concentrations can also activate IDE. There are no observable differences in average conformation between the IDE-ATP complex and unliganded IDE, but regions of the active site and C-terminal domain do show increased crystallographic thermal factors in the complex, suggesting an effect on dynamics. Activation by ATP is shown to be independent of the ATP hydrolysis activity reported for the enzyme. We also report that IDEK898A,K899A,S901A has reduced intracellular function relative to unmodified IDE, consistent with a possible role for anion activation of IDE activity in vivo. Together, the data suggest a model in which the binding of anions activates by reducing the electrostatic attraction between the two halves of the enzyme, shifting the partitioning between open and closed conformations of IDE toward the open form.
| S-EPMC3249101 | biostudies-literature
Project description:The insulin-degrading enzyme (IDE) cleaves numerous small peptides, including biologically active hormones and disease-related peptides. The propensity of IDE to degrade neurotoxic A? peptides marks IDE as a potential therapeutic target for Alzheimer disease. Using a synthetic reporter based on the yeast a-factor mating pheromone precursor, which is cleaved by multiple IDE orthologs, we identified seven small molecules that stimulate rat IDE activity in vitro. Half-maximal activation of IDE by the compounds is observed in vitro in the range of 43 to 198 µM. All compounds decrease the K(m) of IDE. Four compounds activate IDE in the presence of the competing substrate insulin, which disproportionately inhibits IDE activity. Two compounds stimulate rat IDE activity in a cell-based assay, indicating that they are cell permeable. The compounds demonstrate specificity for rat IDE since they do not enhance the activities of IDE orthologs, including human IDE, and they appear specific for a-factor-based reporters since they do not enhance rat IDE-mediated cleavage of A?-based reporters. Our results suggest that IDE activators function in the context of specific enzyme-substrate pairs, indicating that the choice of substrate must be considered in addition to target validation in IDE activator screens.
| S-EPMC5901702 | biostudies-literature
Project description:The insulin-degrading enzyme (IDE) is a metalloendopeptidase with a high affinity for insulin. Human genetic polymorphisms in Ide have been linked to increased risk for T2DM. In mice, hepatic Ide ablation causes glucose intolerance and insulin resistance when mice are fed a regular diet.ObjectiveThese studies were undertaken to further investigate its regulatory role in glucose homeostasis and insulin sensitivity in diet-induced obesity.MethodsTo this end, we have compared the metabolic effects of loss versus gain of IDE function in mice fed a high-fat diet (HFD).ResultsWe demonstrate that loss of IDE function in liver (L-IDE-KO mouse) exacerbates hyperinsulinemia and insulin resistance without changes in insulin clearance but in parallel to an increase in pancreatic β-cell function. Insulin resistance was associated with increased FoxO1 activation and a ~2-fold increase of GLUT2 protein levels in the liver of HFD-fed mice in response to an intraperitoneal injection of insulin. Conversely, gain of IDE function (adenoviral delivery) improves glucose tolerance and insulin sensitivity, in parallel to a reciprocal ~2-fold reduction in hepatic GLUT2 protein levels. Furthermore, in response to insulin, IDE co-immunoprecipitates with the insulin receptor in liver lysates of mice with adenoviral-mediated liver overexpression of IDE.ConclusionsWe conclude that IDE regulates hepatic insulin action and whole-body glucose metabolism in diet-induced obesity via insulin receptor levels.
| S-EPMC8616598 | biostudies-literature
Project description:BackgroundHypocatabolism of the amyloid beta-protein (Abeta) by insulin-degrading enzyme (IDE) is implicated in the pathogenesis of Alzheimer disease (AD), making pharmacological activation of IDE an attractive therapeutic strategy. However, it has not been established whether the proteolytic activity of IDE can be enhanced by drug-like compounds.Methodology/principal findingsBased on the finding that ATP and other nucleotide polyphosphates modulate IDE activity at physiological concentrations, we conducted parallel high-throughput screening campaigns in the absence or presence of ATP and identified two compounds--designated Ia1 and Ia2--that significantly stimulate IDE proteolytic activity. Both compounds were found to interfere with the crosslinking of a photoaffinity ATP analogue to IDE, suggesting that they interact with a bona fide ATP-binding domain within IDE. Unexpectedly, we observed highly synergistic activation effects when the activity of Ia1 or Ia2 was tested in the presence of ATP, a finding that has implications for the mechanisms underlying ATP-mediated activation of IDE. Notably, Ia1 and Ia2 activated the degradation of Abeta by approximately 700% and approximately 400%, respectively, albeit only when Abeta was presented in a mixture also containing shorter substrates.Conclusions/significanceThis study describes the first examples of synthetic small-molecule activators of IDE, showing that pharmacological activation of this important protease with drug-like compounds is achievable. These novel activators help to establish the putative ATP-binding domain as a key modulator of IDE proteolytic activity and offer new insights into the modulatory action of ATP. Several larger lessons abstracted from this screen will help inform the design of future screening campaigns and facilitate the eventual development of IDE activators with therapeutic utility.
| S-EPMC2668070 | biostudies-literature
Project description:Insulin is a hormone vital for glucose homeostasis, and insulin-degrading enzyme (IDE) plays a key role in its clearance. IDE exhibits a remarkable specificity to degrade insulin without breaking the disulfide bonds that hold the insulin A and B chains together. Using Fourier transform ion cyclotron resonance (FTICR) mass spectrometry to obtain high mass accuracy, and electron capture dissociation (ECD) to selectively break the disulfide bonds in gas phase fragmentation, we determined the cleavage sites and composition of human insulin fragments generated by human IDE. Our time-dependent analysis of IDE-digested insulin fragments reveals that IDE is highly processive in its initial cleavage at the middle of both the insulin A and B chains. This ensures that IDE effectively splits insulin into inactive N- and C-terminal halves without breaking the disulfide bonds. To understand the molecular basis of the recognition and unfolding of insulin by IDE, we determined a 2.6-A resolution insulin-bound IDE structure. Our structure reveals that IDE forms an enclosed catalytic chamber that completely engulfs and intimately interacts with a partially unfolded insulin molecule. This structure also highlights how the unique size, shape, charge distribution, and exosite of the IDE catalytic chamber contribute to its high affinity ( approximately 100 nm) for insulin. In addition, this structure shows how IDE utilizes the interaction of its exosite with the N terminus of the insulin A chain as well as other properties of the catalytic chamber to guide the unfolding of insulin and allowing for the processive cleavages.
| S-EPMC2682866 | biostudies-literature
Project description:Diabetes is a metabolic disease that may lead to different life-threatening complications. While insulin constitutes a beneficial treatment, its use may be limited due to increased degradation and an increase in side effects such as weight gain and hypoglycemia. Small molecule inhibitors to insulin-degrading enzyme (IDE) have been previously suggested as a potential treatment for diabetes through their ability to reduce insulin degradation and thus increase insulin activity. Nevertheless, their tendency to bind to the zinc ion in the catalytic site of IDE may affect other important metalloproteases and limit their clinical use. Here, we describe the isolation of an IDE-specific antibody that specifically inhibits insulin degradation by IDE. Using phage display, we generated a human IDE-specific antibody that binds human and mouse IDE with high affinity and specificity and can differentiate between active IDE to a mutated IDE with reduced catalytic activity in the range of 30 nM. We further assessed the ability of that IDE-inhibiting antibody to improve insulin activity in vivo in an STZ-induced diabetes mouse model. Since human antibodies may stimulate the mouse immune response to generate anti-human antibodies, we reformatted our inhibitory antibody to a "reverse chimeric" antibody that maintained the ability to inhibit IDE in vitro, but consisted of mouse constant regions, for reduced immunogenicity. We discovered that one intraperitoneal (IP) administration of the IDE-specific antibody in STZ-induced diabetic mice improved insulin activity in an insulin tolerance test (ITT) assay and reduced blood glucose levels. Our results suggest that antibody-mediated inhibition of IDE may be beneficial on improving insulin activity in a diabetic environment.
| S-EPMC8958001 | biostudies-literature
Project description:Although obesity is associated with overactivation of the white adipose tissue (WAT) renin-angiotensin system (RAS), a causal link between the latter and systemic insulin resistance is not established. We tested the hypothesis that overexpression of angiotensinogen (Agt) from WAT causes systemic insulin resistance via modulation of adipose inflammation. Glucose tolerance, systemic insulin sensitivity, and WAT inflammatory markers were analyzed in mice overexpressing Agt in the WAT (aP2-Agt mice). Proteomic studies and in vitro studies using 3T3-L1 adipocytes were performed to build a mechanistic framework. Male aP2-Agt mice exhibited glucose intolerance, insulin resistance, and lower insulin-stimulated glucose uptake by the skeletal muscle. The difference in glucose tolerance between genotypes was normalized by high-fat (HF) feeding, and was significantly improved by treatment with angiotensin-converting enzyme (ACE) inhibitor captopril. aP2-Agt mice also had higher monocyte chemotactic protein-1 (MCP-1) and lower interleukin-10 (IL-10) in the WAT, indicating adipose inflammation. Proteomic studies in WAT showed that they also had higher monoglyceride lipase (MGL) and glycerol-3-phosphate dehydrogenase levels. Treatment with angiotensin II (Ang II) increased MCP-1 and resistin secretion from adipocytes, which was prevented by cotreating with inhibitors of the nuclear factor-?B (NF-?B) pathway or nicotinamide adenine dinucleotide phosphate (NADPH) oxidase. In conclusion, we show for the first time that adipose RAS overactivation causes glucose intolerance and systemic insulin resistance. The mechanisms appear to be via reduced skeletal muscle glucose uptake, at least in part due to Ang II-induced, NADPH oxidase and NF?B-dependent increases in WAT inflammation.
| S-EPMC4465436 | biostudies-literature
Project description:Insulin-degrading enzyme (IDE) is a highly conserved and ubiquitously expressed metalloprotease that degrades insulin and several other intermediate-size peptides. For many decades, IDE had been assumed to be involved primarily in hepatic insulin clearance, a key process that regulates availability of circulating insulin levels for peripheral tissues. Emerging evidence, however, suggests that IDE has several other important physiological functions relevant to glucose and insulin homeostasis, including the regulation of insulin secretion from pancreatic β-cells. Investigation of mice with tissue-specific genetic deletion of Ide in the liver and pancreatic β-cells (L-IDE-KO and B-IDE-KO mice, respectively) has revealed additional roles for IDE in the regulation of hepatic insulin action and sensitivity. In this review, we discuss current knowledge about IDE's function as a regulator of insulin secretion and hepatic insulin sensitivity, both evaluating the classical view of IDE as an insulin protease and also exploring evidence for several non-proteolytic functions. Insulin proteostasis and insulin sensitivity have both been highlighted as targets controlling blood sugar levels in type 2 diabetes, so a clearer understanding the physiological functions of IDE in pancreas and liver could led to the development of novel therapeutics for the treatment of this disease.
| S-EPMC7830943 | biostudies-literature
Project description:Insulin-degrading enzyme (IDE) is a human mononuclear Zn2+ -dependent metalloenzyme that is widely regarded as the primary peptidase responsible for insulin degradation. Despite its name, IDE is also critically involved in the hydrolysis of several other disparate peptide hormones, including glucagon, amylin, and the amyloid β-protein. As such, the study of IDE inhibition is highly relevant to deciphering the role of IDE in conditions such as type-2 diabetes mellitus and Alzheimer disease. There have been few reported IDE inhibitors, and of these, inhibitors that directly target the active-site Zn2+ ion have yet to be fully explored. In an effort to discover new, zinc-targeting inhibitors of IDE, a library of ∼350 metal-binding pharmacophores was screened against IDE, resulting in the identification of 1-hydroxypyridine-2-thione (1,2-HOPTO) as an effective Zn2+ -binding scaffold. Screening a focused library of HOPTO compounds identified 3-sulfonamide derivatives of 1,2-HOPTO as inhibitors of IDE (Ki values of ∼50 μM). Further structure-activity relationship studies yielded several thiophene-sulfonamide HOPTO derivatives with good, broad-spectrum activity against IDE that have the potential to be useful pharmacological tools for future studies of IDE.
| S-EPMC8627785 | biostudies-literature