Cerium and Yttrium Oxide Nanoparticles and Nano-selenium Produce Protective Effects Against H2O2-induced Oxidative Stress in Pancreatic Beta Cells by Modulating Mitochondrial Dysfunction

2020 ◽  
Vol 8 (1) ◽  
pp. 63-75 ◽  
Author(s):  
Shima Tavoosi ◽  
Amir Hossein Baghsheikhi ◽  
Seyed Vahid Shetab-Boushehri ◽  
Mona Navaei-Nigjeh ◽  
Nazanin Namazi Sarvestani ◽  
...  

Background: Type 1 diabetes mellitus is characterized by the destruction of insulin- producing Beta cells in the pancreas. Researchers hope that islet transplantation will help to patients with insulin-dependent diabetes mellitus (IDDM). Oxidative stress is the most important challenge that beta cells face to it after isolation, and mitochondrial dysfunction is a crucial mediator in beta cells death. Hence, therapeutic approaches can shift to antioxidants through the application of nanoparticles such as cerium and yttrium oxide nanoparticles (Cer and Ytt Ox NPs) and nano-selenium (Nan Se). Objectives: This study evaluates the effects of Cer and Ytt Ox NPs and Nan Se on H2O2- induced oxidative stress in pancreatic beta cells with focus on mitochondrial dysfunction pathway. Methods: CRI-D2 beta-cell line were pretreated with Cer Ox NPs (200 µM) + Ytt Ox NPs (0.5 µg/mL) for 3 days and/or Nan Se (0.01 µM) for 1 day. Then markers of oxidative stress, mitochondrial dysfunction, insulin and glucagon secretion were measured. Results: We reported a decrease in H2O2-induced reactive oxygen species (ROS) level and glucagon secretion, and an increase in H2O2-reduced ATP/ADP ratio, MMP, as well as UCP2 protein expression, and insulin secretion by pretreatment of CRI-D2 cells with Cer and Ytt Ox NPs and/or Nan Se. Conclusion: We found maximum protective effect with Cer and Ytt Ox NPs on CRI-D2 beta-cell line exposed by H2O2 for keeping beta cells alive until transplant whereas combination of Cer and Ytt Ox NPs and Nan Se had very little protective effect in this condition.

2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Xiang Kong ◽  
Chong-xiao Liu ◽  
Guo-dong Wang ◽  
Hui Yang ◽  
Xin-ming Yao ◽  
...  

Type 2 diabetes mellitus is a chronic metabolic disorder characterized by elevated blood glucose and/or high serum free fatty acids. Chronic hyperlipidemia causes the dysfunction of pancreatic beta cells, which is aggravated in the presence of hyperglycemia (glucolipotoxicity). Long noncoding RNAs (lncRNAs) have been suggested to play key roles in type 1 diabetes mellitus development. However, their roles in glucolipotoxicity-induced beta cell dysfunction are not fully understood. In the present study, we identified the differentially expressed lncRNAs in INS-1 cells exposed to high glucose and palmitate (HG/PA). Among the dysregulated lncRNAs, NONRATT003679.2 (low expression in glucolipotoxicity-treated beta cells (LEGLTBC)) was involved in glucolipotoxicity-evoked rat islet beta cell damage. LEGLTBC functioned as a molecular sponge of miR-34a in INS-1 cells. Additionally, SIRT1 was identified as a target of miR-34a and LEGLTBC promoted SIRT1 expression by sponging miR-34a. The upregulation of LEGLTBC attenuated HG/PA-induced INS-1 cell injury through the promotion of SIRT1-mediated suppression of ROS accumulation and apoptosis. This is the first study to comprehensively identify the lncRNA expression profiling of HG/PA-treated INS-1 beta cells and to demonstrate that LEGLTBC functions as a competing endogenous RNA and regulates miR-34a/SIRT1-mediated oxidative stress and apoptosis in INS-1 cells undergoing glucolipotoxicity.


2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Faer Morrison ◽  
Karen Johnstone ◽  
Anna Murray ◽  
Jonathan Locke ◽  
Lorna W. Harries

Altered expression of oxidative metabolism genes has been described in the skeletal muscle of individuals with type 2 diabetes. Pancreatic beta cells contain low levels of antioxidant enzymes and are particularly susceptible to oxidative stress. In this study, we explored the effect of hyperglycemia-induced oxidative stress on a panel of oxidative metabolism genes in a rodent beta cell line. We exposed INS-1 rodent beta cells to low (5.6 mmol/L), ambient (11 mmol/L), and high (28 mmol/L) glucose conditions for 48 hours. Increases in oxidative stress were measured using the fluorescent probe dihydrorhodamine 123. We then measured the expression levels of a panel of 90 oxidative metabolism genes by real-time PCR. Elevated reactive oxygen species (ROS) production was evident in INS-1 cells after 48 hours (P<0.05). TLDA analysis revealed a significant (P<0.05) upregulation of 16 of the 90 genes under hyperglycemic conditions, although these expression differences did not reflect differences in ROS. We conclude that although altered glycemia may influence the expression of some oxidative metabolism genes, this effect is probably not mediated by increased ROS production. The alterations to the expression of oxidative metabolism genes previously observed in human diabetic skeletal muscle do not appear to be mirrored in rodent pancreatic beta cells.


2018 ◽  
Vol 52 (1) ◽  
pp. 21-26 ◽  
Author(s):  
Eiji Yamato

Abstract Objective. Histone deacytylase inhibitors (HDACis) inhibit the deacetylation of the lysine residue of proteins, including histones, and regulate the transcription of a variety of genes. Recently, HDACis have been used clinically as anti-cancer drugs and possible anti-diabetic drugs. Even though HDACis have been proven to protect the cytokine-induced damage of pancreatic beta cells, evidence also shows that high doses of HDACis are cytotoxic. In the present study, we, therefore, investigated the eff ect of HDACis on insulin secretion in a pancreatic beta cell line. Methods. Pancreatic beta cells MIN6 were treated with selected HDACis (trichostatin A, TSA; valproic acid, VPA; and sodium butyrate, NaB) in medium supplemented with 25 mM glucose and 13% heat-inactivated fetal bovine serum (FBS) for indicated time intervals. Protein expression of Pdx1 and Mafa in MIN6 cells was demonstrated by immunohistochemistry and immunocytochemistry, expression of Pdx1 and Mafa genes was measured by quantitative RT-PCR method. Insulin release from MIN6 cells and insulin cell content were estimated by ELISA kit. Superoxide production in MIN6 cells was measured using a Total ROS/Superoxide Detection System. Results. TSA, VPA, and NaB inhibited the expression of Pdx1 and Mafa genes and their products. TSA treatment led to beta cell malfunction, characterized by enhanced insulin secretion at 3 and 9 mM glucose, but impaired insulin secretion at 15 and 25 mM glucose. Th us, TSA induced dysregulation of the insulin secretion mechanism. TSA also enhanced reactive oxygen species production in pancreatic beta cells. Conclusions. Our results showed that HDACis caused failure to suppress insulin secretion at low glucose concentrations and enhance insulin secretion at high glucose concentrations. In other words, when these HDACis are used clinically, high doses of HDACis may cause hypoglycemia in the fasting state and hyperglycemia in the fed state. When using HDACis, physicians should, therefore, be aware of the capacity of these drugs to modulate the insulin secretory capacity of pancreatic beta cells.


1989 ◽  
Vol 257 (6) ◽  
pp. C1171-C1176 ◽  
Author(s):  
H. H. Keahey ◽  
A. E. Boyd ◽  
D. L. Kunze

The mechanisms by which norepinephrine and epinephrine activate alpha 2-adrenergic receptors and inhibit insulin release from the pancreatic beta-cell (19, 21, 23) are not yet clear but may involve modulation at several sites. Because intracellular calcium has been implicated in the secretory process, it has been suggested that catecholamines may inhibit secretion by blocking calcium influx, thus reducing the free cytosolic calcium concentration (23). The present study examines the effects of epinephrine, norepinephrine, and clonidine on calcium current in an SV40-transformed hamster beta-cell line (HIT cells). Under voltage-clamp conditions, calcium currents were reversibly inhibited by norepinephrine, epinephrine, and clonidine in the low nanomolar range. The effects were blocked by 1) the alpha 2-antagonist yohimbine, 2) preincubation of the cells with pertussis toxin (PTX), and 3) guanosine 5'-O-(2-thiodiphosphate) (GDP beta S), the nonhydrolyzable GDP analogue that competitively inhibits the interaction of GTP with G proteins. In contrast, guanosine 5'-O-(3-thiotriphosphate) (GTP gamma S) caused irreversible blockade by catecholamines. These effects could not be overcome by adenosine 3',5'-cyclic monophosphate (cAMP), suggesting that the adenylate cyclase pathway is not involved in the G protein coupling with the channels. These studies show that catecholamines inhibit calcium currents in beta-cells through an alpha 2-adrenoreceptor PTX-sensitive G protein pathway and could inhibit insulin secretion by this mechanism.


2021 ◽  
Author(s):  
kevin Saitoski ◽  
Maria Ryaboshapkina ◽  
Ghaith Hamza ◽  
Andrew F Jarnuczak ◽  
claire berthault ◽  
...  

Aims/hypothesis: Proprotein convertase subtilisin/kexin 9 (PCSK9) is involved in the degradation of LDLR. However, PCSK9 can target other proteins in a cell-type specific manner. While PCSK9 has been detected in pancreatic islets, its expression in insulin-producing pancreatic beta cells is debated. Herein, we studied PCSK9 expression, regulation and function in the human pancreatic beta cell line EndoC-βH1. Methods: We assessed PCSK9 expression in mouse and human pancreatic islets, and in the pancreatic beta cell line EndoC-βH1. We also studied PCSK9 regulation by cholesterol, lipoproteins, Mevastatin, and by SREBPs transcription factors. To evaluate PCSK9 function in pancreatic beta cells, we performed PCSK9 gain-and loss-of-function experiments in EndoC-βH1 using siPCSK9 or recombinant PCSK9 treatments, respectively. Results: We demonstrate that PCSK9 is expressed and secreted by pancreatic beta cells. In EndoC-βH1 cells, PCSK9 expression is regulated by cholesterol and by SREBPs transcription factors. Importantly, PCSK9 knockdown results in multiple transcriptome, proteome and secretome deregulations and impaired insulin secretion. By gain- and loss-of- function experiments, we observed that PCSK9 regulates the expression levels of LDLR and VLDLR through an extracellular mechanism while CD36, PD-L1 and HLA-ABC are regulated through an intracellular mechanism. Conclusions/interpretation: Collectively, these results highlight PCSK9 as an important regulator of CD36, PD-L1 and HLA-ABC cell surface expression in pancreatic beta cells. Data availability: RNA-seq data have been deposited to GEO database with accession number GSE182016. Mass spectrometry proteomics data have been deposited to the ProteomeXchange Consortium via the PRIDE partner repository with the following identifiers: PXD027921, PXD027911 and PXD027913.


Antioxidants ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 658 ◽  
Author(s):  
Ming-Shih Lee ◽  
Charng-Cherng Chyau ◽  
Chi-Ping Wang ◽  
Ting-Hsuan Wang ◽  
Jing-Hsien Chen ◽  
...  

Oxidative stress is highly associated with the development of diabetes mellitus (DM), especially pancreatic beta-cell injury. Flavonoids derived from plants have caused important attention in the prevention or treatment of DM. Lotus seedpod belongs to a traditional Chinese herbal medicine and has been indicated to possess antioxidant, anti-age, anti-glycative, and hepatoprotective activities. The purpose of this study was to demonstrate the pancreatic beta-cell protective effects of lotus seedpod aqueous extracts (LSE) against oxidative injury. According to HPLC/ESI-MS-MS method, LSE was confirmed to have flavonoids derivatives, especially quercetin-3-glucuronide (Q3G). In vitro, LSE dose-dependently improved the survival and function of rat pancreatic beta-cells (RIN-m5F) from hydrogen peroxide (H2O2)-mediated loss of cell viability, impairment of insulin secretion, and promotion of oxidative stress. LSE showed potential in decreasing the H2O2-induced occurrence of apoptosis. In addition, H2O2-triggered acidic vesicular organelle formation and microtubule-associated protein light chain 3 (LC3)-II upregulation, markers of autophagy, were increased by LSE. Molecular data explored that antiapoptotic and autophagic effects of LSE, comparable to that of Q3G, might receptively be mediated via phospho-Bcl-2-associated death promoter (p-Bad)/B-cell lymphoma 2 (Bcl-2) and class III phosphatidylinositol-3 kinase (PI3K)/LC3-II signal pathway. In vivo, LSE improved the DM symptoms and pancreatic cell injury better than metformin, a drug that is routinely prescribed to treat DM. These data implied that LSE induces the autophagic signaling, leading to protect beta-cells from oxidative stress-related apoptosis and injury.


1990 ◽  
Vol 259 (2) ◽  
pp. E216-E224 ◽  
Author(s):  
K. Thermos ◽  
M. D. Meglasson ◽  
J. Nelson ◽  
K. M. Lounsbury ◽  
T. Reisine

The characteristics of somatostatin (SRIF) receptors in rat pancreatic beta-cells were investigated using rat islets and the beta-cell line HIT-T15 (HIT). The biochemical properties of the SRIF receptors were examined with 125I-labeled des-Ala-1,Gly-2-desamino-Cys-3-[Tyr-11]- dicarba3,14-somatostatin (CGP 23996). 125I-CGP 23996 bound to SRIF receptors in HIT cells with high affinity and in a saturable manner. The binding of 125I-CGP 23996 to SRIF receptors was blocked by SRIF analogues with a rank order of potency of somatostatin 28 (SRIF-28) greater than D-Trp-8-somatostatin greater than somatostatin 14 (SRIF-14). To investigate the physical properties of the HIT cell SRIF receptor, the receptor was covalently labeled with 125I-CGP 23996 using photo-cross-linking techniques. 125I-CGP 23996 specifically labeled a protein of 55 kDa in HIT cell membranes. The size of the SRIF receptor in HIT cells is similar to the size of the SRIF receptor labeled with 125I-CGP 23996 in membranes of freshly isolated islets, suggesting that the physical properties of SRIF receptors in HIT cells and rat islet cells are similar. The binding studies suggest that beta-cells predominantly express a SRIF-28-preferring receptor. In freshly isolated islets, glucose- and arginine-stimulated insulin release was effectively blocked by SRIF-28 but not by SRIF-14. SRIF-14 did inhibit arginine-stimulated glucagon secretion from freshly isolated islets. The dissociation of the inhibitory effects of SRIF-28 and SRIF-14 on insulin and glucagon release from freshly isolated islets suggests that the two peptides act through different receptors in islets to regulate hormone secretion.


1976 ◽  
Vol 143 (5) ◽  
pp. 1170-1185 ◽  
Author(s):  
J W Yoon ◽  
A L Notkins

Beta cells were isolated from strains of mice that were susceptible and resistant to encephalomyocarditis (EMC) viral-induced diabetes mellitus. Beta cells from susceptible mice that were infected in vivo with EMC virus showed higher viral titers, more severe degranulation, and lower concentrations of immunoreactive insulin than beta cells from resistant mice. Immunofluorescence and infectious center assays revealed that pancreas from susceptible mice contained at least 10 times more infected cells than pancreas from resistant mice. Beta cell cultures prepared from susceptible mice and infected in vitro also showed higher viral titers and more severe cytopathologic changes than beta cell cultures from resistant mice. In contrast to beta cell cultures, virus replicated equally well in primary embryo and kidney cell cultures from susceptible and resistant strains of mice. It is concluded that the development of EMC virus-induced diabetes is related to genetically determined host differences in the capacity of the virus to infect beta cells.


2021 ◽  
Author(s):  
Gabriel Brawerman ◽  
Peter J. Thompson

Pancreatic beta cells are essential endocrine cells in the islets of Langerhans that respond to increases in blood glucose by secreting insulin and their dysfunction and death drives the development of diabetes. Beta cell senescence involving a DNA damage response (DDR) was recently shown to contribute to the pathogenesis of Type 1 Diabetes (T1D), however, a basic mechanistic understanding of how senescence develops in beta cells is lacking. Here, we investigated senescent phenotypes arising in the mouse beta cell line NIT1 derived from the T1D susceptible nonobese diabetic (NOD) mouse strain and the transcriptome response in human islets after induction of DNA damage. Sub-lethal DNA damage in NIT1 cells led to several classical hallmarks of senescence including the DDR, growth arrest, enlarged flattened morphology and a senescence-associated secretory phenotype (SASP) resembling what occurs during T1D. RNA-seq analysis on human islets with DNA double-strand break damage revealed a coordinated p53-p21 transcriptional response and upregulation of genes involved in prosurvival signaling and SASP. Taken together, these findings suggest that some of the phenotypes of mouse and human beta cell senescence during T1D can be induced by DNA damage in NIT1 cells and human islets in culture.


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