scholarly journals Reducing sugars trigger oxidative modification and apoptosis in pancreatic β-cells by provoking oxidative stress through the glycation reaction

1996 ◽  
Vol 320 (3) ◽  
pp. 855-863 ◽  
Author(s):  
Hideaki KANETO ◽  
Junichi FUJII ◽  
Theingi MYINT ◽  
Nobuko MIYAZAWA ◽  
Kazi N. ISLAM ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Dna Cleavage ◽  
Reducing Sugars ◽  
Islet Cells ◽  
Chromatin Condensation ◽  
Oxidative Modification ◽  
Lipid Peroxidation Product ◽  
Β Cells ◽  
Pancreatic Β Cells ◽  
Peroxidation Product

Several reducing sugars brought about apoptosis in isolated rat pancreatic islet cells and in the pancreatic β-cell-derived cell line HIT. This apoptosis was characterized biochemically by internucleosomal DNA cleavage and morphologically by nuclear shrinkage, chromatin condensation and apoptotic body formation. N-Acetyl-l-cysteine, an antioxidant, and aminoguanidine, an inhibitor of the glycation reaction, inhibited this apoptosis. We also showed directly that proteins in β-cells were actually glycated by using an antibody which can specifically recognize proteins glycated by fructose, but not by glucose. Furthermore, fluorescence-activated cell sorting analysis using dichlorofluorescein diacetate showed that reducing sugars increased intracellular peroxide levels prior to the induction of apoptosis. Levels of carbonyl, an index of oxidative modification, and of malondialdehyde, a lipid peroxidation product, were also increased. Taken together, these results suggest that reducing sugars trigger oxidative modification and apoptosis in pancreatic β-cells by provoking oxidative stress mainly through the glycation reaction, which may explain the deterioration of β-cells under conditions of diabetes.

scholarly journals GLP1-derived nonapeptide GLP1(28–36)amide protects pancreatic β-cells from glucolipotoxicity

2012 ◽  
Vol 213 (2) ◽  
pp. 143-154 ◽  
Author(s):  
Zhengu Liu ◽  
Violeta Stanojevic ◽  
Luke J Brindamour ◽  
Joel F Habener
Keyword(s):  
Oxidative Stress ◽  
Insulin Resistance ◽  
Insulin Secretion ◽  
Islet Cells ◽  
Blood Levels ◽  
Β Cells ◽  
Β Cell ◽  
Pancreatic Β Cells ◽  
Cell Functions

Type 2 diabetes, often associated with obesity, results from a deficiency of insulin production and action manifested in increased blood levels of glucose and lipids that further promote insulin resistance and impair insulin secretion. Glucolipotoxicity caused by elevated plasma glucose and lipid levels is a major cause of impaired glucose-stimulated insulin secretion from pancreatic β-cells, due to increased oxidative stress, and insulin resistance. Glucagon-like peptide-1 (GLP1), an insulinotropic glucoincretin hormone, is known to promote β-cell survival via its actions on its G-protein-coupled receptor on β-cells. Here, we report that a nonapeptide, GLP1(28–36)amide, derived from the C-terminal domain of the insulinotropic GLP1, exerts cytoprotective actions on INS-1 β-cells and on dispersed human islet cells in vitro in conditions of glucolipotoxicity and increased oxidative stress independently of the GLP1 receptor. The nonapeptide appears to enter preferably stressed, glucolipotoxic cells compared with normal unstressed cells. It targets mitochondria and improves impaired mitochondrial membrane potential, increases cellular ATP levels, inhibits cytochrome c release, caspase activation, and apoptosis, and enhances the viability and survival of INS-1 β-cells. We propose that GLP1(28–36)amide might be useful in alleviating β-cell stress and might improve β-cell functions and survival.

scholarly journals Synergistic Effects of Milk-Derived Exosomes and Galactose on α-Synuclein Pathology in Parkinson’s Disease and Type 2 Diabetes Mellitus

2021 ◽  
Vol 22 (3) ◽  
pp. 1059
Author(s):  
Bodo C. Melnik
Keyword(s):  
Oxidative Stress ◽  
Diabetes Mellitus ◽  
Type 2 Diabetes ◽  
Type 2 Diabetes Mellitus ◽  
Dopaminergic Neurons ◽  
Vagal Nerve ◽  
Β Cells ◽  
Pancreatic Β Cells ◽  
The Brain

Epidemiological studies associate milk consumption with an increased risk of Parkinson’s disease (PD) and type 2 diabetes mellitus (T2D). PD is an α-synucleinopathy associated with mitochondrial dysfunction, oxidative stress, deficient lysosomal clearance of α-synuclein (α-syn) and aggregation of misfolded α-syn. In T2D, α-syn promotes co-aggregation with islet amyloid polypeptide in pancreatic β-cells. Prion-like vagal nerve-mediated propagation of exosomal α-syn from the gut to the brain and pancreatic islets apparently link both pathologies. Exosomes are critical transmitters of α-syn from cell to cell especially under conditions of compromised autophagy. This review provides translational evidence that milk exosomes (MEX) disturb α-syn homeostasis. MEX are taken up by intestinal epithelial cells and accumulate in the brain after oral administration to mice. The potential uptake of MEX miRNA-148a and miRNA-21 by enteroendocrine cells in the gut, dopaminergic neurons in substantia nigra and pancreatic β-cells may enhance miRNA-148a/DNMT1-dependent overexpression of α-syn and impair miRNA-148a/PPARGC1A- and miRNA-21/LAMP2A-dependent autophagy driving both diseases. MiRNA-148a- and galactose-induced mitochondrial oxidative stress activate c-Abl-mediated aggregation of α-syn which is exported by exosome release. Via the vagal nerve and/or systemic exosomes, toxic α-syn may spread to dopaminergic neurons and pancreatic β-cells linking the pathogenesis of PD and T2D.

Abstract 5702: Oxidative Stress in Patients with Lone Atrial Fibrillation

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Kengo Kusano ◽  
Kazufumi Nakamura ◽  
Tohru Ohe
Keyword(s):  
Oxidative Stress ◽  
Atrial Fibrillation ◽  
Immunohistochemical Analysis ◽  
Lipid Peroxidation Product ◽  
Lone Atrial Fibrillation ◽  
Activated T Cells ◽  
Mhc I ◽  
Mhc Ii ◽  
Peroxidation Product ◽  
Ros Formation

Background: Lone atrial fibrillation (LAF) is a common arrhythmia, but its mechanism and the aggravated factor of arrhythmia are poorly understood. Oxidative stress has been implicated in the pathogenesis of heart failure. We have previously demonstrated that the amount of 4-hydroxy-2-nonenal (HNE) modified protein, which is a major lipid peroxidation product and a cytotoxic aldehyde, causes intracellular Ca2+ overload via reactive oxygen species (ROS) formation in cardiomyocytes and leads to develop arrhythmia. Accordingly we examined the levels of HNE and major histocompatibility complex (MHC) with the disease severity in LAF patients. Method: Atrial and ventricular myocardial samples were obtained from twelve patients (11 men and 1 woman, mean 48±14 years old) by endomyocardial biopsy in 10, autopsy sample in 1 and surgical resection sample in 1. Histological assessments and immunohistochemical analysis for HNE modified protein, MHC class-I and -II antigens (grade 0 to 3) were performed and compared with LAF severity. Results: Histological assessment showed that increased number of interstitial cells (mainly activated T cells) was observed only in the atrium but not in the ventricle. Moderate to severe expression of MHC antigens (grade 2 or 3) was more observed in the atrium than the ventricle (MHC-I: seven in atrium and three in ventricle; MHC-II: ten in atrium and four in ventricle). Atrial myocarditis was detected in 6 out of 11 samples. HNE modified protein was also more observed in the atrium than that in the ventricle. In addition, more severe expression of HNE staining was observed in the samples from persistent/chronic LAF than that in paroxysmal LAF. Conclusion: These data indicates that oxidative stress plays an important role as an aggravating factor in LAF patients.

scholarly journals Cytoprotective Effects of N-Acetylcysteine on Streptozotocin- Induced Oxidative Stress and Apoptosis in RIN-5F Pancreatic β-Cells

2018 ◽  
Vol 51 (1) ◽  
pp. 201-216 ◽  
Author(s):  
Arwa M.T. Al-Nahdi ◽  
Annie John ◽  
Haider  Raza
Keyword(s):  
Oxidative Stress ◽  
Insulin Secretion ◽  
Molecular Mechanisms ◽  
Protective Action ◽  
Mitochondrial Enzymes ◽  
Partial Recovery ◽  
Β Cells ◽  
Pancreatic Β Cells ◽  
Mitochondrial Energy Metabolism ◽  
Mitochondrial Functions

Background/Aims: Numerous studies have reported overproduction of reactive oxygen species (ROS) and alterations in mitochondrial energy metabolism in the development of diabetes and its complications. The potential protective effects of N-acetylcysteine (NAC) in diabetes have been reported in many therapeutic studies. NAC has been shown to reduce oxidative stress and enhance redox potential in tissues protecting them against oxidative stress associated complications in diabetes. In the current study, we aimed to investigate the molecular mechanisms of the protective action of NAC on STZ-induced toxicity in insulin secreting Rin-5F pancreatic β-cells. Methods: Rin-5F cells were grown to 80% confluence and then treated with 10mM STZ for 24h in the presence or absence of 10mM NAC. After sub-cellular fractionation, oxidative stress, GSH-dependent metabolism and mitochondrial respiratory functions were studied using spectrophotometric, flow cytometric and Western blotting techniques. Results: Our results showed that STZ-induced oxidative stress and apoptosis caused inhibition in insulin secretion while NAC treatment restored the redox homeostasis, enhanced insulin secretion in control cells and prevented apoptosis in STZ-treated cells. Moreover, NAC attenuated the inhibition of mitochondrial functions induced by STZ through partial recovery of the mitochondrial enzymes and restoration of membrane potential. STZ-induced DNA damage and expression of apoptotic proteins were significantly inhibited in NAC-treated cells. Conclusion: Our results suggest that the cytoprotective action of NAC is mediated via suppression of oxidative stress and apoptosis and restoration of GSH homeostasis and mitochondrial bioenergetics. This study may, thus, help in better understanding the cellular defense mechanisms of pancreatic β-cells against STZ-induced cytotoxicity.

scholarly journals Carotid intima-media thickness and oxidative stress markers for assessment of atherosclerosis in children with β thalassemia major

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Geetanjali Jindal ◽  
Prashant Chavan ◽  
Ravinder Kaur ◽  
Shivani Jaswal ◽  
Kamal Kumar Singhal ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Lipid Peroxidation ◽  
Oxidized Ldl ◽  
Thalassemia Major ◽  
Lipid Peroxidation Product ◽  
Oxidative Stress Markers ◽  
Lipoprotein A ◽  
Stress Markers ◽  
Total Antioxidant ◽  
Peroxidation Product

<p>The present study evaluates carotid intimamedia thickness (CIMT) in children with β thalassemia major to assess atherosclerosis and its relation to the underlying proposed causative mechanisms <em>via</em> lipid peroxidation product malondialdehyde (MDA), oxidized lowdensity lipoproteins (LDL), total antioxidant level, and lipid profile. A cross sectional study was conducted on 62 children (31 cases and 31 controls). CIMT by high resolution ultrasound and biochemical parameters <em>i.e.</em>, total cholesterol, triglycerides, high-density lipoproteins, LDL, Oxidized LDL, lipoprotein (a), lipid peroxidation product MDA and total antioxidant were measured in enrolled subjects and compared. In our study, CIMT was significantly increased in β thalassemia major patients’ as compared to healthy controls. Mean CIMT in cases was 0.69±0.11 mm and in controls 0.51±0.07 mm. Mean oxidized LDL (EU/mL) in cases 39.3±34.4 (range 14.4 to 160) was significantly raised (P=0.02, t test) as compared to controls 23.9±13.4 (range 12 to 70). In our study we found MDA levels (nmol/mL) to be increased in β thalassemia patients as compared to controls. Mean MDA was 10.0±3.27 (4.41 to 17.48) in cases while in controls was 6.87±4.55 (1.5 to 17.9). Our study results show CIMT as an early marker of atherogenesis in β thalassemia major. Oxidative stress markers are also increased in β thalassemia major patients and lipoprotein (a) shows a positive correlation with CIMT. The present study points towards various atherogenetic mechanisms in β thalassemia major.</p><p> </p><p>本研究评价β重型地中海贫血患儿颈动脉内膜中层厚度（CIMT），以评估动脉粥样硬化，以及与潜在通过血脂过氧化反应产物丙二醛（MDA）、氧化低密度脂蛋白（LDL）、总抗氧化水平和血脂谱所提出致病机制之间的关系。 在62名儿童（31例病例和31例对照）中进行了一项横断面研究。 在入组受试者中通过高分辨率超声和生化指标（即总胆固醇、甘油三酯、高密度脂蛋白、LDL、氧化LDL，脂蛋白（a）、血脂过氧化产物MDA和总抗氧化剂）测量CIMT并进行比较。 在我们的研究中，CIMT在β重型地中海贫血患者中比健康对照组显著增加。 病例组中的平均CIMT为0.69±0.11 mm，对照组0.51±0.07 mm。病例组中平均氧化LDL（EU/mL）为39.3±34.4（从14.4到160的范围）与对照组的23.9±13.4（12至70的范围）相比显著升高（P = 0.02，t检验）。 在我们的研究中，我们发现β地中海贫血患者中的MDA水平（nmol/mL）比对照组更高。 病例组中的平均MDA为10.0±3.27（4.41至17.48），而对照组为6.87±4.55（1.5到17.9）。 我们的研究结果表明，CIMT是β重型地中海贫血动脉粥样硬化的早期标记物。 氧化应激标记物在β重型地中海贫血患者中也有增加，脂蛋白（a）显示出与CIMT呈正相关。 本研究针对β重型地中海贫血中的各种动脉粥样硬化机制。</p>

scholarly journals Differential cell autonomous responses determine the outcome of coxsackievirus infections in murine pancreatic α and β cells

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Laura Marroqui ◽  
Miguel Lopes ◽  
Reinaldo S dos Santos ◽  
Fabio A Grieco ◽  
Merja Roivainen ◽  
...  
Keyword(s):  
Gene Networks ◽  
Viral Infections ◽  
Islet Cells ◽  
Global Gene Expression ◽  
Cell Types ◽  
Autoimmune Response ◽  
Β Cells ◽  
Pancreatic Β Cells ◽  
Antiviral Responses ◽  
Different Cell Types

Type 1 diabetes (T1D) is an autoimmune disease caused by loss of pancreatic β cells via apoptosis while neighboring α cells are preserved. Viral infections by coxsackieviruses (CVB) may contribute to trigger autoimmunity in T1D. Cellular permissiveness to viral infection is modulated by innate antiviral responses, which vary among different cell types. We presently describe that global gene expression is similar in cytokine-treated and virus-infected human islet cells, with up-regulation of gene networks involved in cell autonomous immune responses. Comparison between the responses of rat pancreatic α and β cells to infection by CVB5 and 4 indicate that α cells trigger a more efficient antiviral response than β cells, including higher basal and induced expression of STAT1-regulated genes, and are thus better able to clear viral infections than β cells. These differences may explain why pancreatic β cells, but not α cells, are targeted by an autoimmune response during T1D.

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