Unraveling the molecular machinery that promotes pancreatic β-cell dysfunction during oxidative stress: focus on “Phagocyte-like NADPH oxidase promotes cytokine-induced mitochondrial dysfunction in pancreatic β-cells: evidence for regulation by Rac1”

2011 ◽  
Vol 300 (1) ◽  
pp. R9-R11 ◽  
Author(s):  
Martin Jastroch
Keyword(s):  
Oxidative Stress ◽  
Nadph Oxidase ◽  
Mitochondrial Dysfunction ◽  
Pancreatic Β Cell ◽  
Β Cells ◽  
Β Cell ◽  
Pancreatic Β Cells ◽  
Cell Dysfunction ◽  
Molecular Machinery

scholarly journals mTORC in β cells: more Than Only Recognizing Comestibles

2017 ◽  
Vol 216 (7) ◽  
pp. 1883-1885 ◽  
Author(s):  
Kathrin Maedler ◽  
Amin Ardestani
Keyword(s):  
Oxidative Stress ◽  
Mitochondrial Dysfunction ◽  
Cell Survival ◽  
Pancreatic Β Cell ◽  
Β Cells ◽  
Β Cell ◽  
Pancreatic Β Cells ◽  
Cell Biol

The pathways regulating pancreatic β cell survival in diabetes are poorly understood. Here, Chau et al. (2017. J. Cell Biol. https://doi.org/10.1083/jcb.201701085) demonstrate that mTOR regulates the apoptotic machinery through binding to the ChREBP–Mlx complex to suppress TXNIP, thereby protecting pancreatic β cells in the diabetic setting by inhibiting oxidative stress and mitochondrial dysfunction.

Effects of pharmacological inhibition of NADPH oxidase or iNOS on pro-inflammatory cytokine, palmitic acid or H2O2-induced mouse islet or clonal pancreatic β-cell dysfunction

2010 ◽  
Vol 30 (6) ◽  
pp. 445-453 ◽  
Author(s):  
Marta Michalska ◽  
Gabriele Wolf ◽  
Reinhard Walther ◽  
Philip Newsholme
Keyword(s):  
Fatty Acids ◽  
Insulin Secretion ◽  
Nadph Oxidase ◽  
Inflammatory Cytokine ◽  
Pancreatic Β Cell ◽  
Β Cells ◽  
Β Cell ◽  
Cell Dysfunction ◽  
Mouse Islets ◽  
Pro Inflammatory Cytokines

Various pancreatic β-cell stressors including cytokines and saturated fatty acids are known to induce oxidative stress, which results in metabolic disturbances and a reduction in insulin secretion. However, the key mechanisms underlying dysfunction are unknown. We investigated the effects of prolonged exposure (24 h) to pro-inflammatory cytokines, H2O2 or PA (palmitic acid) on β-cell insulin secretion, ATP, the NADPH oxidase (nicotinamide adenine dinucleotide phosphate oxidase) component p47phox and iNOS (inducible nitric oxide synthase) levels using primary mouse islets or clonal rat BRIN-BD11 β-cells. Addition of a pro-inflammatory cytokine mixture [IL-1β (interleukin-1β), TNF-α (tumour necrosis factor-α) and IFN-γ (interferon-γ)] or H2O2 (at sub-lethal concentrations) inhibited chronic (24 h) levels of insulin release by at least 50% (from islets and BRIN-BD11 cells), while addition of the saturated fatty acid palmitate inhibited acute (20 min) stimulated levels of insulin release from mouse islets. H2O2 decreased ATP levels in the cell line, but elevated p47phox and iNOS levels as did cytokine addition. Similar effects were observed in mouse islets with respect to elevation of p47phox and iNOS levels. Addition of antioxidants SOD (superoxide dismutase), Cat (catalase) and NAC (N-acetylcysteine) attenuated H2O2 or the saturated fatty acid palmitate-dependent effects, but not cytokine-induced dysfunction. However, specific chemical inhibitors of NADPH oxidase and/or iNOS appear to significantly attenuate the effects of cytokines, H2O2 or fatty acids in islets. While pro-inflammatory cytokines are known to increase p47phox and iNOS levels in β-cells, we now report that H2O2 can increase levels of the latter two proteins, suggesting a key role for positive-feedback redox sensitive regulation of β-cell dysfunction.

scholarly journals The Role of Oxidative Stress in Pancreatic β Cell Dysfunction in Diabetes

2021 ◽  
Vol 22 (4) ◽  
pp. 1509
Author(s):  
Natsuki Eguchi ◽  
Nosratola D. Vaziri ◽  
Donald C. Dafoe ◽  
Hirohito Ichii
Keyword(s):  
Oxidative Stress ◽  
Cell Function ◽  
Pancreatic Β Cell ◽  
Antioxidative Capacity ◽  
Β Cells ◽  
Β Cell ◽  
Glucose Levels ◽  
Cell Dysfunction ◽  
Elevated Glucose ◽  
Β Cell Function

Diabetes is a chronic metabolic disorder characterized by inappropriately elevated glucose levels as a result of impaired pancreatic β cell function and insulin resistance. Extensive studies have been conducted to elucidate the mechanism involved in the development of β cell failure and death under diabetic conditions such as hyperglycemia, hyperlipidemia, and inflammation. Of the plethora of proposed mechanisms, endoplasmic reticulum (ER) stress, mitochondrial dysfunction, and oxidative stress have been shown to play a central role in promoting β cell dysfunction. It has become more evident in recent years that these 3 factors are closely interrelated and importantly aggravate each other. Oxidative stress in particular is of great interest to β cell health and survival as it has been shown that β cells exhibit lower antioxidative capacity. Therefore, this review will focus on discussing factors that contribute to the development of oxidative stress in pancreatic β cells and explore the downstream effects of oxidative stress on β cell function and health. Furthermore, antioxidative capacity of β cells to counteract these effects will be discussed along with new approaches focused on preserving β cells under oxidative conditions.

scholarly journals Inhibition of the Keap1/Nrf2 Signaling Pathway Significantly Promotes the Progression of Type 1 Diabetes Mellitus

2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Yanmei Lou ◽  
Muyan Kong ◽  
Leyan Li ◽  
Yu Hu ◽  
Wenjun Zhai ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Signaling Pathway ◽  
Cell Damage ◽  
Pancreatic Β Cell ◽  
Β Cells ◽  
Β Cell ◽  
Pancreatic Β Cells ◽  
Min6 Cells ◽  
Nrf2 Signaling Pathway

Type 1 diabetes mellitus (T1DM) is an autoimmune disease characterized by insulin deficiency due to pancreatic β-cell damage and leads to hyperglycemia. The precise molecular mechanisms of the etiology of T1DM are not completely understood. Oxidative stress and the antioxidant status of pancreatic β-cells play a vital role in the pathogenesis and progression of T1DM. The Keap1/Nrf2 signaling pathway plays a critical role in cellular resistance to oxidative stress. This study is aimed at investigating the role of the Keap1/Nrf2 signaling pathway in the progression of T1DM. An alloxan- (ALX-) stimulated T1DM animal model in wild-type (WT) and Nrf2 knockout (Nrf2-/-) C57BL/6J mice and a mouse pancreatic β-cell line (MIN6) were established. Compared with the tolerant (ALX exposure, nondiabetic) WT mice, the sensitive (ALX exposure, diabetic) WT mice exhibited higher blood glucose levels and lower plasma insulin levels. The Keap1/Nrf2 signaling pathway was significantly inhibited in the sensitive WT mice, which was reflected by overexpression of Keap1 and low expression of Nrf2, accompanied by a marked decrease in the expression of the antioxidative enzymes. Compared with WT mice, the Nrf2-/- mice had an increased incidence of T1DM and exhibited more severe pancreatic β-cell damage. The results of in vitro experiments showed that ALX significantly inhibited the viability and proliferation and promoted the apoptosis of MIN6 cells. ALX also markedly increased intracellular ROS production and caused DNA damage in MIN6 cells. In addition, the Keap1/Nrf2 signaling pathway was significantly inhibited in the damaged MIN6 cells. Moreover, Nrf2 silencing by transfection with Nrf2 siRNA markedly exacerbated ALX-induced MIN6 cell injury. Conclusively, this study demonstrates that inhibition of the Keap1/Nrf2 signaling pathway could significantly promote the incidence of T1DM. This study indicates that activation of Keap1/Nrf2 signaling in pancreatic β-cells may be a useful pharmacological strategy for the clinical prevention and treatment of T1DM.

scholarly journals NADPH Oxidase (NOX) Targeting in Diabetes: A Special Emphasis on Pancreatic β-Cell Dysfunction

Cells ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1573
Author(s):  
Suma Elumalai ◽  
Udayakumar Karunakaran ◽  
Jun-Sung Moon ◽  
Kyu-Chang Won
Keyword(s):  
Nadph Oxidase ◽  
Cell Function ◽  
Negative Impact ◽  
Redox Homeostasis ◽  
Metabolic Stress ◽  
Pancreatic Β Cell ◽  
Β Cells ◽  
Β Cell ◽  
Cell Dysfunction ◽  
Therapeutic Benefits

In type 2 diabetes, metabolic stress has a negative impact on pancreatic β-cell function and survival (T2D). Although the pathogenesis of metabolic stress is complex, an imbalance in redox homeostasis causes abnormal tissue damage and β-cell death due to low endogenous antioxidant expression levels in β-cells. Under diabetogenic conditions, the susceptibility of β-cells to oxidative damage by NADPH oxidase has been related to contributing to β-cell dysfunction. Here, we consider recent insights into how the redox response becomes deregulated under diabetic conditions by NADPH oxidase, as well as the therapeutic benefits of NOX inhibitors, which may provide clues for understanding the pathomechanisms and developing strategies aimed at the treatment or prevention of metabolic stress associated with β-cell failure.

Glucolipotoxicity-induced oxidative stress is related to mitochondrial dysfunction and apoptosis of pancreatic β-cell

2020 ◽  
Vol 16 ◽  
Author(s):  
Jorge E. Vela-Guajardo ◽  
Salvador Garza-González ◽  
Noemí García
Keyword(s):  
Oxidative Stress ◽  
Cell Death ◽  
Insulin Secretion ◽  
Mitochondrial Dysfunction ◽  
Mitochondrial Dynamics ◽  
Atp Synthesis ◽  
Β Cells ◽  
Β Cell ◽  
Pancreatic Β Cells ◽  
Diabetes Development

: Glucolipotoxicity-induced oxidative stress and mitochondrial dysfunction of pancreatic β-cells are one of the mechanisms that have been related to the low insulin secretion and cell death during diabetes development. In early or non-chronic stages, the pancreatic β-cells respond to hyperglycemia or hyperlipidemia, stimulating insulin secretion. However, the chronic effect of both leads to the establishment of glucolipotoxicity which induces constant overstimulation of pancreatic β-cells, a condition that leads to cell death by apoptosis. The mechanism described, at this moment, is the accelerated mitochondrial dysfunction triggered by the high production of reactive oxygen species (ROS) due to excess nutrients. At first, mitochondria respond to over-nutrition accelerating oxygen consumption and consequently increasing the ATP synthesis. A permanent increase of ATP/ADP ratio leads to a constant inhibition of K+ ATP-channel and therefore a continuous insulin secretion accompanied by an increase in ROS. Finally, ROS accumulation compromises mitochondrial function due to the uncontrolled oxidation of proteins, lipids, and DNA generating functional alterations such as a drop of membrane potential, deregulation of mitochondrial dynamics, low rate of ATP synthesis and consequently the cell death. This review aims to describe the effect of glucolipotoxicity-induced oxidative stress and its relationship with mitochondrial dysfunction in β-cell during type 2 diabetes development.

scholarly journals Antioxidant N-Acetylcysteine Protects Pancreatic β-Cells Against Aldosterone-Induced Oxidative Stress and Apoptosis in Female db/db Mice and Insulin-Producing MIN6 Cells

Endocrinology ◽  
2013 ◽  
Vol 154 (11) ◽  
pp. 4068-4077 ◽  
Author(s):  
Hui Min Jin ◽  
Dong Chi Zhou ◽  
Hui Fang Gu ◽  
Qing Yan Qiao ◽  
Shun Kun Fu ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Mineralocorticoid Receptor ◽  
Oxidative Stress Marker ◽  
Oral Glucose ◽  
Β Cells ◽  
Β Cell ◽  
Pancreatic Β Cells ◽  
Mineralocorticoid Receptor Antagonist ◽  
Min6 Cells ◽  
Cell Dysfunction

Previous studies have shown that primary aldosteronism is associated with glucose-related metabolic disorders. However, the mechanisms by which aldosterone (ALDO) triggers β-cell dysfunction remains unclear. This study aimed to investigate whether oxidative stress is involved in and whether the antioxidant N-acetylcysteine (NAC) or the mineralocorticoid receptor antagonist spironolactone (SPL) could prevent or delay β-cell damage in vivo and in vitro. As expected, 8 weeks after ALDO treatment, 12-week-old female diabetic db/db mice exhibited impaired oral glucose tolerance, decreased β-cell mass, and heightened levels of oxidative stress marker (urinary 8-hydroxy-2′-deoxyguanosine). NAC reversed these symptoms completely, whereas SPL treatment did so only partially. After exposure to ALDO, the mouse pancreatic β-cell line MIN6 exhibited decreased viability and increased caspase-3 activity, as well as reduced expression of Bcl-2/Bax and p-AKT, even if mineralocorticoid receptor was completely suppressed with small interfering RNA. NAC, but not SPL, suppressed oxidative stress in MIN6 cells, as revealed by the decrease in inducible NOS levels and expression of the proteins p22-phox and p67-phox. These findings suggest that oxidative stress may be involved in ALDO-induced β-cell dysfunction and that NAC, but not SPL, may protect pancreatic β-cells of mice from ALDO-induced oxidative stress and apoptosis in a manner independent of its receptor.

scholarly journals Augmented Rac1 Expression and Activity are Associated with Oxidative Stress and Decline of β Cell Function in Obesity

2015 ◽  
Vol 35 (6) ◽  
pp. 2135-2148 ◽  
Author(s):  
Shutong Zhou ◽  
Dongni Yu ◽  
Shangyong Ning ◽  
Heli Zhang ◽  
Lei Jiang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Nadph Oxidase ◽  
Cell Function ◽  
Β Cells ◽  
Β Cell ◽  
Cell Dysfunction ◽  
Insulin Mrna ◽  
Rac1 Expression

Background: The aim of this study was to clarify the relationship among Rac1 expression and activation, oxidative stress and β cell dysfunction in obesity. Methods: In vivo, serum levels of glucose, insulin, oxidative stress markers and Rac1 expression were compared between ob/ob mice and C57BL/6J controls. Then, these variables were rechecked after the administration of the specific Rac1 inhibitor-NSC23766 in ob/ob mice. In vitro, NIT-1 β cells were cultured in a hyperglycemic and/or hyperlipidemic state with or without NSC23766, and the differences of Rac1 expression and translocation, NADPH oxidase(Nox) enzyme activity, reactive oxygen species (ROS) and insulin mRNA were observed. Results: ob/ob mice displayed abnormal glycometabolism, oxidative stress and excessive expression of Rac1 in the pancreas. NSC23766 injection inhibited the expression of Rac1 in the pancreas, along with amelioration of oxidative stress and glycometabolism in obese mice. Under hyperglycemic and/or hyperlipidemic conditions, Rac1 translocated to the cellular membrane, induced activation of the NADPH oxidase enzyme and oxidative stress, and simultaneously reduced the insulin mRNA expression in NIT-1 β cells. Inhibiting Rac1 activity could alleviate oxidative stress and meliorate the decline of insulin mRNA in β cells. Conclusions: Rac1 might contribute to oxidative stress systemically and locally in the pancreas in obesity. The excessive activation and expression of Rac1 in obesity were associated with β cell dysfunction through ROS production.

Molecular aspects of pancreatic β‐cell dysfunction: Oxidative stress, microRNA, and long noncoding RNA

2018 ◽  
Vol 234 (6) ◽  
pp. 8411-8425 ◽  
Author(s):  
Mohammad Javad Saeedi Borujeni ◽  
Ebrahim Esfandiary ◽  
Azar Baradaran ◽  
Ali Valiani ◽  
Mustafa Ghanadian ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Long Noncoding Rna ◽  
Noncoding Rna ◽  
Pancreatic Β Cell ◽  
Β Cell ◽  
Cell Dysfunction ◽  
Molecular Aspects

Chlorogenic acid and β-glucan from highland barley grain ameliorate β cell dysfunction via inhibiting apoptosis and improving cell proliferation

2021 ◽  
Author(s):  
Zehua Liu ◽  
Bo Li
Keyword(s):  
Cell Proliferation ◽  
Chlorogenic Acid ◽  
Barley Grain ◽  
Whole Grain ◽  
Β Cells ◽  
Β Cell ◽  
Pancreatic Β Cells ◽  
Active Compounds ◽  
Cell Dysfunction ◽  
Highland Barley

Recent studies support the view that highland barley as whole grain diet showed anti-hyperglycemic effects, while little information is available about the active compounds that could ameliorate pancreatic β cells...

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