scholarly journals Spatiotemporal Regulators for Insulin-Stimulated GLUT4 Vesicle Exocytosis

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Xiaoxu Zhou ◽  
Ping Shentu ◽  
Yingke Xu
Keyword(s):  
Insulin Signaling ◽  
Signaling Molecules ◽  
Regulatory Proteins ◽  
Peripheral Insulin Resistance ◽  
Spatiotemporal Regulation ◽  
Storage Vesicles ◽  
Vesicle Exocytosis ◽  
And Storage ◽  
Adipose Cells

Insulin increases glucose uptake and storage in muscle and adipose cells, which is accomplished through the mobilization of intracellular GLUT4 storage vesicles (GSVs) to the cell surface upon stimulation. Importantly, the dysfunction of insulin-regulated GLUT4 trafficking is strongly linked with peripheral insulin resistance and type 2 diabetes in human. The insulin signaling pathway, key signaling molecules involved, and precise trafficking itinerary of GSVs are largely identified. Understanding the interaction between insulin signaling molecules and key regulatory proteins that are involved in spatiotemporal regulation of GLUT4 vesicle exocytosis is of great importance to explain the pathogenesis of diabetes and may provide new potential therapeutic targets.

Regulating insulin signaling and β-cell function through IRS proteinsThis paper is one of a selection of papers published in this Special Issue, entitled Second Messengers and Phosphoproteins—12th International Conference.

2006 ◽  
Vol 84 (7) ◽  
pp. 725-737 ◽  
Author(s):  
Morris F. White
Keyword(s):  
Insulin Resistance ◽  
Type 2 Diabetes ◽  
Insulin Signaling ◽  
Cell Function ◽  
Second Messengers ◽  
Glucose Sensing ◽  
Β Cell ◽  
Peripheral Insulin Resistance ◽  
Chronic Hyperglycemia

Diabetes mellitus is a complex disorder that arises from various causes, including dysregulated glucose sensing and impaired insulin secretion (maturity onset diabetes of youth, MODY), autoimmune-mediated β-cell destruction (type 1), or insufficient compensation for peripheral insulin resistance (type 2). Type 2 diabetes is the most prevalent form that usually occurs at middle age; it afflicts more than 30 million people over the age of 65, but is appearing with greater frequency in children and adolescents. Dysregulated insulin signaling exacerbated by chronic hyperglycemia promotes a cohort of systemic disorders—including dyslipidemia, hypertension, cardiovascular disease, and female infertility. Understanding the molecular basis of insulin resistance can prevent these disorders and their inevitable progression to type 2 diabetes.

scholarly journals Isolation and Proteomics of the Insulin Secretory Granule

Metabolites ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 288
Author(s):  
Nicholas Norris ◽  
Belinda Yau ◽  
Melkam Alamerew Kebede
Keyword(s):  
Pancreatic Beta Cells ◽  
Secretory Granules ◽  
Future Directions ◽  
Isolation And Purification ◽  
Peripheral Insulin Resistance ◽  
Beta Cell Compensation ◽  
Insulin Secretory Granule ◽  
And Storage ◽  
Rat Insulinoma

Insulin, a vital hormone for glucose homeostasis is produced by pancreatic beta-cells and when secreted, stimulates the uptake and storage of glucose from the blood. In the pancreas, insulin is stored in vesicles termed insulin secretory granules (ISGs). In Type 2 diabetes (T2D), defects in insulin action results in peripheral insulin resistance and beta-cell compensation, ultimately leading to dysfunctional ISG production and secretion. ISGs are functionally dynamic and many proteins present either on the membrane or in the lumen of the ISG may modulate and affect different stages of ISG trafficking and secretion. Previously, studies have identified few ISG proteins and more recently, proteomics analyses of purified ISGs have uncovered potential novel ISG proteins. This review summarizes the proteins identified in the current ISG proteomes from rat insulinoma INS-1 and INS-1E cell lines. Here, we also discuss techniques of ISG isolation and purification, its challenges and potential future directions.

scholarly journals Dual-mode of insulin action controls GLUT4 vesicle exocytosis

2011 ◽  
Vol 193 (4) ◽  
pp. 643-653 ◽  
Author(s):  
Yingke Xu ◽  
Bradley R. Rubin ◽  
Charisse M. Orme ◽  
Alexander Karpikov ◽  
Chenfei Yu ◽  
...  
Keyword(s):  
Phospholipase D ◽  
Insulin Signaling ◽  
Insulin Action ◽  
Fusion Pore ◽  
Dual Mode ◽  
Vesicle Traffic ◽  
Storage Vesicles ◽  
Vesicle Exocytosis ◽  
Single Vesicle ◽  
Pore Expansion

Insulin stimulates translocation of GLUT4 storage vesicles (GSVs) to the surface of adipocytes, but precisely where insulin acts is controversial. Here we quantify the size, dynamics, and frequency of single vesicle exocytosis in 3T3-L1 adipocytes. We use a new GSV reporter, VAMP2-pHluorin, and bypass insulin signaling by disrupting the GLUT4-retention protein TUG. Remarkably, in unstimulated TUG-depleted cells, the exocytic rate is similar to that in insulin-stimulated control cells. In TUG-depleted cells, insulin triggers a transient, twofold burst of exocytosis. Surprisingly, insulin promotes fusion pore expansion, blocked by acute perturbation of phospholipase D, which reflects both properties intrinsic to the mobilized vesicles and a novel regulatory site at the fusion pore itself. Prolonged stimulation causes cargo to switch from ∼60 nm GSVs to larger exocytic vesicles characteristic of endosomes. Our results support a model whereby insulin promotes exocytic flux primarily by releasing an intracellular brake, but also by accelerating plasma membrane fusion and switching vesicle traffic between two distinct circuits.

scholarly journals Insulin Resistance and Diabetes Mellitus in Alzheimer’s Disease

Cells ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1236
Author(s):  
Jesús Burillo ◽  
Patricia Marqués ◽  
Beatriz Jiménez ◽  
Carlos González-Blanco ◽  
Manuel Benito ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Alzheimer’S Disease ◽  
Insulin Resistance ◽  
Type 2 Diabetes ◽  
Alzheimer's Disease ◽  
Type 2 Diabetes Mellitus ◽  
Insulin Signaling ◽  
Molecular Mechanisms ◽  
Progressive Disease

Type 2 diabetes mellitus is a progressive disease that is characterized by the appearance of insulin resistance. The term insulin resistance is very wide and could affect different proteins involved in insulin signaling, as well as other mechanisms. In this review, we have analyzed the main molecular mechanisms that could be involved in the connection between type 2 diabetes and neurodegeneration, in general, and more specifically with the appearance of Alzheimer’s disease. We have studied, in more detail, the different processes involved, such as inflammation, endoplasmic reticulum stress, autophagy, and mitochondrial dysfunction.

Does impaired mitochondrial function affect insulin signaling and action in cultured human skeletal muscle cells?

2008 ◽  
Vol 294 (1) ◽  
pp. E97-E102 ◽  
Author(s):  
Audrey E. Brown ◽  
Matthias Elstner ◽  
Stephen J. Yeaman ◽  
Douglass M. Turnbull ◽  
Mark Walker
Keyword(s):  
Skeletal Muscle ◽  
Glucose Uptake ◽  
Insulin Signaling ◽  
Mitochondrial Respiration ◽  
Respiratory Function ◽  
Insulin Action ◽  
Human Skeletal Muscle ◽  
Human Skeletal Muscle Cells ◽  
Basal Glucose Uptake

Insulin-resistant type 2 diabetic patients have been reported to have impaired skeletal muscle mitochondrial respiratory function. A key question is whether decreased mitochondrial respiration contributes directly to the decreased insulin action. To address this, a model of impaired cellular respiratory function was established by incubating human skeletal muscle cell cultures with the mitochondrial inhibitor sodium azide and examining the effects on insulin action. Incubation of human skeletal muscle cells with 50 and 75 μM azide resulted in 48 ± 3% and 56 ± 1% decreases, respectively, in respiration compared with untreated cells mimicking the level of impairment seen in type 2 diabetes. Under conditions of decreased respiratory chain function, insulin-independent (basal) glucose uptake was significantly increased. Basal glucose uptake was 325 ± 39 pmol/min/mg (mean ± SE) in untreated cells. This increased to 669 ± 69 and 823 ± 83 pmol/min/mg in cells treated with 50 and 75 μM azide, respectively (vs. untreated, both P < 0.0001). Azide treatment was also accompanied by an increase in basal glycogen synthesis and phosphorylation of AMP-activated protein kinase. However, there was no decrease in glucose uptake following insulin exposure, and insulin-stimulated phosphorylation of Akt was normal under these conditions. GLUT1 mRNA expression remained unchanged, whereas GLUT4 mRNA expression increased following azide treatment. In conclusion, under conditions of impaired mitochondrial respiration there was no evidence of impaired insulin signaling or glucose uptake following insulin exposure in this model system.

Comprehensive Review on Neuro-Degenerative Type 3DM

2021 ◽  
Vol 18 ◽  
Author(s):  
Chandani V. Chandarana ◽  
Salona Roy
Keyword(s):  
Type 2 Diabetes ◽  
Insulin Signaling ◽  
Insulin Signalling ◽  
Amyloid Β ◽  
Diabetes Mellitus Type 1 ◽  
Current Data ◽  
The Body ◽  
Type I ◽  
Therapeutic Benefits

: Alzheimer disease (AD) is thought to be the metabolic illness raised by defective insulin signaling, insulin resistance, and low insulin levels in the brain, according to a growing body of research. The "Type 3 diabetes" has been postulated for AD because reduced insulin signalling has molecular and physiological consequences that are comparable to Type I and Type 2 diabetes mellitus (Type 1 DM and Type 2 DM, respectively). The similarities between type 2 diabetes and Alzheimer's disease suggest that these clinical trials might yield therapeutic benefits. However, it's important to note that lowering your risk of Alzheimer's dementia, whether you have diabetes or not, is still a multidimensional process involving factors like exercise, smoking, alcohol, food, and mental challenge. The current aim is to show the relationship between T3D and AD being based on both the processing of amyloid-β (Aβ) precursor protein toxicity and the clearance of Aβ are the result of an impaired insulin signaling. The brain's metabolism with its high lipid content and energy needs, places excess demands on mitochondria and appears more susceptible to oxidative damage than the rest of the body. Current data suggests that increased oxidative stress relates to amyloid-β (Aβ) pathology and onset of AD.

scholarly journals Zsírsavtúltengés – inzulinrezisztencia és β-sejt-halál

2016 ◽  
Vol 157 (19) ◽  
pp. 733-739 ◽  
Author(s):  
Miklós Csala
Keyword(s):  
Fatty Acids ◽  
Insulin Signaling ◽  
Cell Damage ◽  
Local Inflammation ◽  
Cellular Functions ◽  
Β Cell ◽  
The Metabolic Syndrome ◽  
Rapid Spread ◽  
New Strategies

The increasing prevalence of type 2 diabetes correlates with the rapid spread of obesity worldwide. Adipocytes are strained by the demand of excessive storage, and the local inflammation accelerates triglyceride turnover, which elevates the plasma levels of free fatty acids. Sustained hyper-free fatty acidemia leads to disturbances in cellular functions (lipotoxicity) or even to programmed cell death. Activated stress kinases interfere with insulin signaling, and often facilitate apoptosis. Hyper-free fatty acidemia, therefore, links obesity to diabetes through insulin resistance and β-cell damage. Lipotoxicity research – including the comparison of the effects exerted by saturated, unsaturated and trans fatty acids – provides explanations for long-known phenomena. Our widening knowledge in the field offers new strategies for prevention and treatment of the metabolic syndrome and diabetes. Orv. Hetil., 2016, 157(19), 733–739.

scholarly journals Phenylalanine Impairs Insulin Signaling and Inhibits Glucose Uptake by Modifying IRβ

2021 ◽  
Author(s):  
Qian Zhou ◽  
Wan-Wan Sun ◽  
Jia-Cong Chen ◽  
Huilu Zhang ◽  
Jie Liu ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Type 2 Diabetes ◽  
Amino Acids ◽  
Insulin Receptor ◽  
Glucose Uptake ◽  
Insulin Signaling ◽  
Trna Synthetase ◽  
Blood Samples ◽  
Receptor Beta

Abstract Although elevated circulating amino acids are associated with the onset of type 2 diabetes (T2D), how amino acids act on cell insulin signaling and glucose uptake remains unclear. Herein, we report that phenylalanine modifies insulin receptor beta (IRβ) and inactivates insulin signaling and glucose uptake. Mice fed phenylalanine-rich chow or overexpressing human phenylalanyl-tRNA synthetase (hFARS) developed insulin resistance and symptoms of T2D. Mechanistically, FARS phenylalanylated lysine 1057/1079 of IRβ (F-K1057/1079) inactivated IRβ and prevented insulin from generating insulin signaling to promote glucose uptake by cells. SIRT1 reversed F-K1057/1079 and counteracted the insulin-inactivating effects of hFARS and phenylalanine. F-K1057/1079 and SIRT1 levels of white cells of T2D patients’ blood samples were positively and negatively correlated with T2D onset, respectively. Blocking F-K1057/1079 with phenylalaninol sensitized insulin signaling and relieved T2D symptoms in hFARS-transgenic and db/db mice. We revealed mechanisms of how phenylalanylation inactivates insulin signaling that may be employed to control T2D.

Sign in / Sign up

Export Citation Format

Share Document