Effects of the insulin degrading enzyme silencing on the transcriptome of HepG2 cells
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE61142 | GEO | 2014/09/06
SECONDARY ACCESSION(S): PRJNA260342
REPOSITORIES: GEO
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Project description:Insulin degrading enzyme (IDE) is a major enzyme responsible for insulin degradation in the liver. The modulation of insulin degrading enzyme activity is hypothesized to be a link between T2DM and liver cancer. Results provide insight into role of IDE in proliferation and other cell functions. HepG2 cells were transfected with 96nM siRNA for IDE or AllStars Negative Control siRNA (Qiagen) using Lipofectamine 2000 (Invitrogen). 16 h after transfection, cells were treated with 10 nM insulin (Sigma Aldrich) or vehicle for 24 h in serum starvation condition. Total RNA was extracted. For each of the 4 conditions, 3 biological replicates were included.
2014-09-06 | E-GEOD-61142 | biostudies-arrayexpress
Project description:Oxidative stress has a ubiquitous role in neurodegenerative diseases and oxidative damage in specific regions of the brain is associated with selective neurodegeneration. We previously reported that Alzheimer disease (AD) model mice showed decreased insulin-degrading enzyme (IDE) levels in the cerebrum and accelerated phenotypic features of AD when crossbred with alpha-tocopherol transfer protein knockout (Ttpa-/-) mice. To further investigate the role of chronic oxidative stress in AD pathophysiology, we performed DNA microarray analysis using young and aged wild-type mice and aged Ttpa-/- mice. Among the genes whose expression changed dramatically was Phospholipase A2 group 3 (Pla2g3); Pla2g3 was identified because of its expression profile of cerebral specific up-regulation by chronic oxidative stress in silico and in aged Ttpa-/- mice. Immunohistochemical studies also demonstrated that human astrocytic Pla2g3 expression was significantly increased in human AD brains compared with control brains. Moreover, transfection of HEK293 cells with human Pla2g3 decreased endogenous IDE expression in a dose-dependent manner. Our findings show a key role of Pla2g3 on the reduction of IDE, and suggest that cerebrum specific increase of Pla2g3 is involved in the initiation and/or progression of AD.
2015-11-20 | GSE75047 | GEO
Project description:Oxidative stress has a ubiquitous role in neurodegenerative diseases and oxidative damage in specific regions of the brain is associated with selective neurodegeneration. We previously reported that Alzheimer disease (AD) model mice showed decreased insulin-degrading enzyme (IDE) levels in the cerebrum and accelerated phenotypic features of AD when crossbred with alpha-tocopherol transfer protein knockout (Ttpa-/-) mice. To further investigate the role of chronic oxidative stress in AD pathophysiology, we performed DNA microarray analysis using young and aged wild-type mice and aged Ttpa-/- mice. Among the genes whose expression changed dramatically was Phospholipase A2 group 3 (Pla2g3); Pla2g3 was identified because of its expression profile of cerebral specific up-regulation by chronic oxidative stress in silico and in aged Ttpa-/- mice. Immunohistochemical studies also demonstrated that human astrocytic Pla2g3 expression was significantly increased in human AD brains compared with control brains. Moreover, transfection of HEK293 cells with human Pla2g3 decreased endogenous IDE expression in a dose-dependent manner. Our findings show a key role of Pla2g3 on the reduction of IDE, and suggest that cerebrum specific increase of Pla2g3 is involved in the initiation and/or progression of AD. Gene expression in cerebral cortex and cerebellum of mice were determined using Agilent chips. To ensure higher quality results in gene expression data, we conducted microarrays on 4 mice per group. Young mice were 2 months old and the other aged mice were 29 months old at the time of use. Data were standardized using global normalization and pro-cessed by R-program. An absolute fold change threshold of greater than 1.5 was required to be considered for further analyses. Expression values were in log2 scale.
2015-11-20 | E-GEOD-75047 | biostudies-arrayexpress
Project description:Appropriate tuning of protein homeostasis through mobilization of the unfolded protein response (UPR) is key to the capacity of pancreatic beta cells to cope with highly variable demand for insulin synthesis. An efficient UPR ensures a sufficient beta cell mass and secretory output but can also affect beta cell resilience to autoimmune aggression. However, the factors regulating protein homeostasis in the face of metabolic and immune challenges are insufficie tly understood. We examined beta cell adaptation to stress in mice deficient for insulin-degrading enzyme (IDE), a ubiquitous protease with high affinity for insulin, a putative ill-defined role in protein homeostasis, and genetic association with type 2 diabetes. IDE deficiency induces a low-level UPR in both standard and autoimmune non-obese diabetic (NOD) mice, associated with rapamycin-sensitive beta cell proliferation, as well as protection from diabetes in NOD mice. Moreover, in NOD islets, IDE deficiency specifically induces strong upregulation of regenerating islet-derived protein 2, a protein attenuating inflammation and protecting from autoimmunity. Our findings establish a role of IDE in islet cell protein homeostasis, corroborate the link between low-level UPR and proliferation, and identify an anti-inflammatory islet cell response uncovered in the absence of IDE of potential interest in autoimmune diabetes.
2024-06-16 | PXD034826 | Pride
Project description:Basic helix loop helix enhancer 40 (Bhlhe40) is a transcription factor expressed in rodent hippocampus, however, its role in neuronal function is not well understood. Here, we used Bhlhe40 null mice on a congenic C57Bl6/J background (Bhlhe40 KO) to investigate the impact of Bhlhe40 on neuronal excitability and synaptic plasticity. A whole genome expression array predicted that Bhlhe40 KO mice have up-regulated insulin-related pathways and down-regulated neuronal signaling-related pathways in the hippocampus. We validated that insulin degrading enzyme mRNA (Ide) and IDE protein are significantly downregulated in Bhlhe40 KO hippocampi. No significant difference was observed in hippocampal insulin levels. In hippocampal slices, we found CA1 neurons have increased miniature excitatory post-synaptic current (mEPSC) amplitude and decreased inhibitory post-synaptic current (IPSC) amplitude, indicating hyper-excitability in CA1 neurons in Bhlhe40 KO mice. At CA1 synapses, we found a reduction in long term potentiation (LTP) and long term depression (LTD), indicating an impairment in hippocampal synaptic plasticity in Bhlhe40 KO hippocampal slices. Bhlhe40 KO mice displayed no difference in seizure response to the convulsant kainic acid (KA) relative to controls. We found that while Bhlhe40 KO mice have decreased exploratory behavior they do not display alterations in spatial learning and memory. Together this suggests that Bhlhe40 plays a role in modulating neuronal excitability and synaptic plasticity ex vivo, however, Bhlhe40 alone does not play a significant role in seizure susceptibility and learning and memory in vivo. In addition, based on the reduction in IDE protein levels in these mice, there may be dysregulation of other known IDE substrates, namely insulin growth factor (Igf)-1, Igf-2, and Amyloid beta (Aβ).
2018-05-03 | GSE85959 | GEO
Project description:Although aging is a physiological process to which all organisms are subject, the presence of obesity and type 2 diabetes accelerates biological aging. Recent studies have demonstrated the causal relationships between dietary interventions suppressing obesity and type 2 diabetes and delaying the onset of age-related endocrine changes. Curcumin, a natural antioxidant, has putative therapeutic properties such as reinstating insulin sensitivity in obese mice. However, how curcumin contributes to maintaining insulin homeostasis in aged organisms largely remains unclear. Thus, the objective of this study is to examine the pleiotropic effect of dietary curcumin on insulin homeostasis in a diet-induced obese (DIO) aged mouse model. Aged (18-20 months old) male mice given a high-fat high-sugar diet supplemented with curcumin displayed a different metabolic phenotype compared to mice given a high-fat high-sugar diet alone. Furthermore, curcumin supplementation altered hepatic gene expression profiling, especially insulin signaling and senescence pathways. We then mechanistically investigated how curcumin functions to fine-tune insulin sensitivity. We found that curcumin supplementation increased hepatic insulin degrading enzyme (IDE) expression levels and preserved islet integrity, both of which are beneficial during aging. Our findings suggest that the multifaceted therapeutic potential of curcumin can be used as a protective agent for age-induced metabolic diseases.
2021-11-04 | GSE186971 | GEO
Project description:Glucagon and insulin are counter-regulatory pancreatic hormones that precisely control blood glucose homeostasis1. Type 2 diabetes mellitus (T2DM) is characterized by inappropriately elevated blood glucagon2-5 levels as well as insufficient glucose stimulated insulin secretion (GSIS) by pancreatic ß-cells6. Early in the pathogenesis of T2DM, hyperglucagonemia is observable antecedent to ß-cell dysfunction7-9; and in mice, liver-specific activation of glucagon receptor-dependent signaling results in impaired GSIS10. However, the mechanistic relationship between hyperglucagonemia, hepatic glucagon action, and ß-cell dysfunction remains poorly understood. Here we show that glucagon action stimulates hepatic production of the neuropeptide kisspeptin1, which acts in an endocrine manner on ß-cells to suppress GSIS. In vivo glucagon administration acutely stimulates hepatic kisspeptin1 production, and kisspeptin1 is increased in livers from humans with T2DM and from mouse models of diabetes mellitus. Synthetic kisspeptin1 potently suppresses GSIS in vivo and in vitro from normal isolated islets, which express the kisspeptin1 receptor Kiss1R. Administration of a Kiss1R antagonist in diabetic Leprdb/db mice potently augments GSIS and reduces glycemia. Our observations indicate in the pathogenesis of T2DM an endocrine mechanism sequentially linking hyperglucagonemia via hepatic kisspeptin1 production to impaired insulin secretion. In addition, our findings suggest Kiss1R antagonism as a therapeutic avenue to improve ß-cell function in T2DM. Total RNA from L-Δprkar1a KO mice compared to control D-glucose mice
2014-04-01 | E-GEOD-48815 | biostudies-arrayexpress
Project description:Vascular endothelial growth factor B (VEGFB) plays a crucial role in glucolipid metabolism and is highly associated with type 2 diabetes mellitus (T2DM). The role of VEGFB in the insulin secretion of β cells remains unverified. Thus, this study aims to discuss the effect of VEGFB on regulating insulin secretion in T2DM development, and its underlying mechanism. A high-fat diet and streptozocin were used for inducing T2DM in mice model, and VEGFB gene in islet cells of T2DM mice was knocked out by CRISPR Cas9 and overexpressed by Adeno-Associated Virus (AAV) injection. The effect of VEGFB and its underlying mechanism was assessed by light microscope, electron microscope, fluorescence confocal microscope, enzyme-linked immunosorbent assay, mass spectrometer, and western blot. The decrement of insulin secretion in islet β cell of T2DM mice are aggravated and blood glucose remains at a high level after VEGFB deletion. However, glucose tolerance and insulin sensitivity of T2DM mice were improved after the AAV-VEGFB186 injection. VEGFB knockout or overexpression can inhibit or activate PLCγ/IP3R in a VEGFR1-dependent manner. Then, the change of PLCγ/IP3R caused by VEGFB/VEGFR1 will alter the expression of key factors on the Ca2+/CaMK2 signal pathway such as PPP3CA. Moreover, VEGFB can cause altered insulin secretion by changing the calcium concentration in β cells of T2DM mice. These findings indicated that VEGFB activated the Ca2+/CaMK2 pathway via VEGFR1-PLCγ and IP3R pathway to regulate insulin secretion, which provides new insight into the regulatory mechanism of abnormal insulin secretion in T2DM.
2023-10-24 | PXD043843 | Pride
Project description:The use of proteasome inhibitors (PIs) is the backbone of multiple myeloma (MM) treatment. However, almost all MM patients who initially respond to PIs eventually develop resistance to these drugs. The discovery of a pharmacological intervention that increase the potency of PIs in order to reduce their dose and/or restore the sensitivity of MM cells to PIs is an important avenue in MM research. Insulin Degrading Enzyme (IDE) is a druggable protease known to modulate proteasome. We show here that, in two independent cohorts, a high expression of IDE in cells from MM patients is associated with shorter overall survival. Likewise, we designed specific, cell permeable, IDE inihibitors and showed that full pharmacological engagement of IDE is associated with enhanced sensitivity to PIs of MM cell lines, as well as of primary patient MM cells. Furthermore, treatment of PI-resistant MM cells with the inhibitor overcomes their resistance to PI. Finally we designed an improved IDE inhibitor suitable for in vivo pharmacology. This inhibitor which develops multiple interactions with IDE at the catalytic site and display good pharmacocinetic properties, boosts the anti-myeloma potency of bortezomib in a syngenic mouse model of MM. In vitro, it appears that IDE inhibition reduces the residual proteasome activty in PI-treated cells and increases the apoptotic potency of carfilzomib through induction of an Integrated Stress Response associated with strongly reduced IGF1 and IGF1R expressions. The pharmacological profile of this new combination appears highly desirable for the treatment of MM.
2024-09-15 | GSE184310 | GEO
