scholarly journals TCONS_00230836 silencing restores stearic acid-induced β-cell dysfunction through alleviating endoplasmic reticulum stress via a PERK/eIF2α-dependent pathway rather than apoptosis

2020 ◽  
Author(s):  
Rui Guo ◽  
Yunjin Zhang ◽  
Yue Yu ◽  
Shenghan Su ◽  
Qingrui Zhao ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Endoplasmic Reticulum Stress ◽  
Stearic Acid ◽  
Β Cells ◽  
Β Cell ◽  
Cell Dysfunction ◽  
Acid Diet ◽  
High Stearic Acid ◽  
Mouse Islets ◽  
Dependent Pathway

Abstract Background: Chronic exposure of pancreatic β cells to high levels of stearic acid (C18:0) leads to impaired insulin secretion, which accelerates the progression of type 2 diabetes mellitus (T2DM). Recently, long noncoding RNAs (lncRNAs) were found to participate in saturated fatty acid-induced metabolism dysfunction. However, their contribution to stearic acid-induced β-cell dysfunction remains largely unknown. This study evaluated the possible role of the lncRNA TCONS_00230836 in stearic acid-stimulated lipotoxicity to β cells. Method: Using high-throughput RNA-sequencing, TCONS_00230836 was screened out as being exclusively differentially expressed in stearic acid-treated mouse β-TC6 cells. Co-expression network was constructed to reveal the potential mRNAs targeted for lncRNA TCONS_00230836. Changes in this lncRNA’s and candidate mRNAs’levels were further assessed by real-time PCR in stearic acid-treated β-TC6 cells and islets of mice fed a high-stearic-acid diet (HSD). The localization of TCONS_00230836 was detected by fluorescent in situ hybridization. The endogenous lncRNA TCONS_00230836 in β-TC6 cells was abrogated by its Smart Silencer. Results: The lncRNA TCONS_00230836 was enriched in mouse islets and mainly localized in the cytoplasm. Its expression was significantly increased in stearic acid-treated β-TC6 cells and HSD-fed mouse islets. Knockdown of TCONS_00230836 apparently restored stearic acid-impaired GSIS through alleviating endoplasmic reticulum stress via a PERK/eIF2α-dependent pathway. However, stearic acid-induced β-cell apoptosis was not obviously recovered. Conclusion: Our findings suggest the involvement of the lncRNA TCONS_00230836 in stearic acid-induced β-cell dysfunction, which provides novel insight into stearic acid-induced lipotoxicity to β cells. Anti-lncRNA TCONS_00230836 might be a new therapeutic strategy for alleviating stearic acid-induced β-cell dysfunction in the progression of T2DM.

scholarly journals TCONS_00230836 silencing restores stearic acid-induced β cell dysfunction through alleviating endoplasmic reticulum stress rather than apoptosis

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Rui Guo ◽  
Yunjin Zhang ◽  
Yue Yu ◽  
Shenghan Su ◽  
Qingrui Zhao ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Insulin Secretion ◽  
Endoplasmic Reticulum Stress ◽  
Stearic Acid ◽  
Β Cells ◽  
Β Cell ◽  
Cell Dysfunction ◽  
Acid Diet ◽  
High Stearic Acid ◽  
Mouse Islets

Abstract Background Chronic exposure of pancreatic β cells to high levels of stearic acid (C18:0) leads to impaired insulin secretion, which accelerates the progression of type 2 diabetes mellitus (T2DM). Recently, long noncoding RNAs (lncRNAs) were found to participate in saturated fatty acid-induced metabolism dysfunction. However, their contribution to stearic acid-induced β-cell dysfunction remains largely unknown. This study evaluated the possible role of the lncRNA TCONS_00230836 in stearic acid-stimulated lipotoxicity to β cells. Method Using high-throughput RNA-sequencing, TCONS_00230836 was screened out as being exclusively differentially expressed in stearic acid-treated mouse β-TC6 cells. Co-expression network was constructed to reveal the potential mRNAs targeted for lncRNA TCONS_00230836. Changes in this lncRNA’s and candidate mRNAs’ levels were further assessed by real-time PCR in stearic acid-treated β-TC6 cells and islets of mice fed a high-stearic-acid diet (HSD). The localization of TCONS_00230836 was detected by fluorescent in situ hybridization. The endogenous lncRNA TCONS_00230836 in β-TC6 cells was abrogated by its Smart Silencer. Results TCONS_00230836 was enriched in mouse islets and mainly localized in the cytoplasm. Its expression was significantly increased in stearic acid-treated β-TC6 cells and HSD-fed mouse islets. Knockdown of TCONS_00230836 significantly restored stearic acid-impaired glucose-stimulated insulin secretion through alleviating endoplasmic reticulum stress. However, stearic acid-induced β cell apoptosis was not obviously recovered. Conclusion Our findings suggest the involvement of TCONS_00230836 in stearic acid-induced β-cell dysfunction, which provides novel insight into stearic acid-induced lipotoxicity to β cells. Anti-lncRNA TCONS_00230836 might be a new therapeutic strategy for alleviating stearic acid-induced β-cell dysfunction in the progression of T2DM.

scholarly journals Overexpression of miR-297b-5p protects against stearic acid-induced pancreatic β-cell apoptosis by targeting LATS2

2020 ◽  
Vol 318 (3) ◽  
pp. E430-E439 ◽  
Author(s):  
Rui Guo ◽  
Yue Yu ◽  
Yunjin Zhang ◽  
Yinling Li ◽  
Xia Chu ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Stearic Acid ◽  
Palmitic Acid ◽  
Cell Apoptosis ◽  
Control Group ◽  
Β Cell ◽  
Cell Dysfunction ◽  
High Stearic Acid ◽  
Mouse Islets

Chronic exposure to high concentrations of stearic acid (C18:0) can result in β -cell dysfunction, leading to development of type 2 diabetes. However, the molecular mechanisms underlying the destructive effects of stearic acid on β-cells remain largely unknown. In this study, we aimed to investigate the role of miR-297b-5p on stearic acid-induced β-cell apoptosis. Differential expression of microRNAs (miRNAs) was assessed in a β-TC6 cell line exposed to stearic acid, palmitic acid, or a normal culture medium by high-throughput sequencing. The apoptosis rate was measured by flow cytometry after miR-297b-5p mimic/inhibitor transfection, and large-tumor suppressor kinase 2 (LATS2) was identified as a target of miR-297b-5p using a luciferase activity assay. In vivo, C57BL/6 mice were fed with normal and high-stearic-acid diet, respectively. Mouse islets were used for similar identification of miR-297b-5p and Lats2 in β-TC6 cell. We selected two differentially expressed miRNAs in stearic acid compared with those in the palmitic acid and control groups. miR-297b-5p expression was significantly lower in β-TC6 cells and mouse islets in stearic acid than in control group. Upregulation of miR-297b-5p alleviated the stearic acid-induced cell apoptosis and reduction in insulin secretion by inhibiting Lats2 expression in vitro. Meanwhile, silencing Lats2 significantly reversed the stearic acid-stimulated β-cell dysfunction in both β-TC6 cells and islets. Our findings indicate a suppressive role for miR-297b-5p in stearic acid-induced β-cell apoptosis, which may reveal a potential target for the treatment of β-cell dysfunction in the pathogenesis of type 2 diabetes.

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 Orphan Nuclear Receptor NR4A1 Protects Pancreatic β-Cells from Endoplasmic Reticulum (ER) Stress-mediated Apoptosis

2015 ◽  
Vol 290 (34) ◽  
pp. 20687-20699 ◽  
Author(s):  
Cong Yu ◽  
Shang Cui ◽  
Chen Zong ◽  
Weina Gao ◽  
Tongfu Xu ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Er Stress ◽  
Β Cells ◽  
Β Cell ◽  
Pancreatic Β Cells ◽  
Survivin Promoter ◽  
Min6 Cells ◽  
Chop Expression ◽  
Mouse Islets

The role of NR4A1 in apoptosis is controversial. Pancreatic β-cells often face endoplasmic reticulum (ER) stress under adverse conditions such as high free fatty acid (FFA) concentrations and sustained hyperglycemia. Severe ER stress results in β-cell apoptosis. The aim of this study was to analyze the role of NR4A1 in ER stress-mediated β-cell apoptosis and to characterize the related mechanisms. We confirmed that upon treatment with the ER stress inducers thapsigargin (TG) or palmitic acid (PA), the mRNA and protein levels of NR4A1 rapidly increased in both MIN6 cells and mouse islets. NR4A1 overexpression in MIN6 cells conferred resistance to cell loss induced by TG or PA, as assessed by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, and TUNEL assays indicated that NR4A1 overexpression also protected against ER stress-induced apoptosis. This conclusion was further confirmed by experiments exploiting siRNA to knockdown NR4A1 expression in MIN6 cells or exploiting NR4A1 knock-out mice. NR4A1 overexpression in MIN6 cells reduced C/EBP homologous protein (CHOP) expression and Caspase3 activation induced by TG or PA. NR4A1 overexpression in MIN6 cells or mouse islets resulted in Survivin up-regulation. A critical regulatory element was identified in Survivin promoter (−1872 bp to −1866 bp) with a putative NR4A1 binding site; ChIP assays demonstrated that NR4A1 physically associates with the Survivin promoter. In conclusion, NR4A1 protects pancreatic β-cells against ER stress-mediated apoptosis by up-regulating Survivin expression and down-regulating CHOP expression, which we termed as “positive and negative regulation.”

scholarly journals Activation of Nicotinic Acetylcholine Receptors Decreases Apoptosis in Human and Female Murine Pancreatic Islets

Endocrinology ◽  
2016 ◽  
Vol 157 (10) ◽  
pp. 3800-3808 ◽  
Author(s):  
Philippe Klee ◽  
Domenico Bosco ◽  
Audrey Guérardel ◽  
Emmanuel Somm ◽  
Audrey Toulotte ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Cell Death ◽  
Endoplasmic Reticulum Stress ◽  
Nicotinic Acetylcholine Receptors ◽  
Acetylcholine Receptors ◽  
B Cell Lymphoma ◽  
Β Cells ◽  
Β Cell ◽  
Nicotinic Acetylcholine ◽  
Mitochondrial Outer Membrane Permeabilization

Type 1 diabetes (T1DM) results from destruction of most insulin-secreting pancreatic β-cells. The persistence of β-cells decades after the onset of the disease indicates that the resistance of individual cells to the autoimmune insult is heterogeneous and might depend on the metabolic status of a cell at a given moment. The aim of this study is to investigate whether activation of nicotinic acetylcholine receptors (nACh-Rs) could increase β-cell resistance against the adverse environment prevailing at the onset of T1DM. Here, we show that nACh-R activation by nicotine and choline, 2 agonists of the receptor, decreases murine and human β-cell apoptosis induced by proinflammatory cytokines known to be present in the islet environment at the onset of T1DM. The protective mechanism activated by nicotine and choline involves attenuation of mitochondrial outer membrane permeabilization via modulation of endoplasmic reticulum stress, of the activity of B-cell lymphoma 2 family proteins and cytoplasmic calcium levels. Local inflammation and endoplasmic reticulum stress being key determinants of β-cell death in T1DM, we conclude that pharmacological activation of nACh-R could represent a valuable therapeutic option in the modulation of β-cell death in T1DM.

scholarly journals Oxidative and endoplasmic reticulum stress in β-cell dysfunction in diabetes

2015 ◽  
Vol 56 (2) ◽  
pp. R33-R54 ◽  
Author(s):  
Sumaira Z Hasnain ◽  
Johannes B Prins ◽  
Michael A McGuckin
Keyword(s):  
Oxidative Stress ◽  
Endoplasmic Reticulum ◽  
Er Stress ◽  
Inflammatory Cytokines ◽  
Cell Stress ◽  
Insulin Biosynthesis ◽  
Central Feature ◽  
Β Cells ◽  
Β Cell ◽  
Cell Dysfunction

The inability of pancreatic β-cells to make sufficient insulin to control blood sugar is a central feature of the aetiology of most forms of diabetes. In this review we focus on the deleterious effects of oxidative stress and endoplasmic reticulum (ER) stress on β-cell insulin biosynthesis and secretion and on inflammatory signalling and apoptosis with a particular emphasis on type 2 diabetes (T2D). We argue that oxidative stress and ER stress are closely entwined phenomena fundamentally involved in β-cell dysfunction by direct effects on insulin biosynthesis and due to consequences of the ER stress-induced unfolded protein response. We summarise evidence that, although these phenomenon can be driven by intrinsic β-cell defects in rare forms of diabetes, in T2D β-cell stress is driven by a range of local environmental factors including increased drivers of insulin biosynthesis, glucolipotoxicity and inflammatory cytokines. We describe our recent findings that a range of inflammatory cytokines contribute to β-cell stress in diabetes and our discovery that interleukin 22 protects β-cells from oxidative stress regardless of the environmental triggers and can correct much of diabetes pathophysiology in animal models. Finally we summarise evidence that β-cell dysfunction is reversible in T2D and discuss therapeutic opportunities for relieving oxidative and ER stress and restoring glycaemic control.

Stress-Associated Endoplasmic Reticulum Protein 1 Protected High Glucose-Induced Islet β Cells from Apoptosis by Attenuating Endoplasmic Reticulum Stress

2019 ◽  
Vol 9 (12) ◽  
pp. 1731-1738
Author(s):  
Shulong Guo ◽  
Shaoya Wang ◽  
Youxiao Zeng ◽  
Qiaosheng Hu
Keyword(s):  
Endoplasmic Reticulum ◽  
Endoplasmic Reticulum Stress ◽  
Western Blotting ◽  
High Glucose ◽  
Islet Cell ◽  
Β Cells ◽  
Β Cell ◽  
Tnf Α ◽  
Endoplasmic Reticulum Protein ◽  
Related Proteins

The incidence of type II diabetes caused by islet cell injury is increasing in recent years. Endoplasmic reticulum stress is one of the crucial causes of islet β cell damage, and stress-associated endoplasmic reticulum protein 1 (SERP1) could inhibit the occurrence and development of endoplasmic reticulum stress. But whether SERP1 could inhibit the damage of islet β cell caused by endoplasmic reticulum stress is unclear. In this study, we detected the levels of SERP1 and endoplasmic reticulum stress related proteins (p-PERK, p-Eif2 α, ATF-4 and CHOP) by western blotting. Next the lentivirus was used to construct the islet cell line which was stable overexpressed SERP1. Then the expression of endoplasmic reticulum stress related proteins and inflammatory factors was determined with western blotting. At last the apoptosis rates of islet β cells were detected by flow cytometry. We found that high glucose medium promoted the expression of p-PERK, p-Eif2 α, ATF-4 and CHOP while downregulated the levels of SERP1 in isletβ cells. Moreover, overexpression of SERP1 induced the downregulation of levels of p-PERK, p-Eif2 α, ATF-4, CHOP, TNF-α , IL-1β and IL-6 and alleviated the apoptosis of islet cells. At last, the overexpression of CHOP rescued the apoptosis rates and the expression of TNF-α, IL-1β and IL-6. These results indicated SERP1 relieved the inflammation response and apoptosis of islet β cells by inhibiting the expression of CHOP and alleviating the endoplasmic reticulum stress induced damage.

scholarly journals Inhibition of lncRNA TCONS_00077866 Ameliorates the High Stearic Acid Diet-Induced Mouse Pancreatic β-Cell Inflammatory Response by Increasing miR-297b-5p to Downregulate SAA3 Expression

2021 ◽  
Author(s):  
Huimin Lu ◽  
Rui Guo ◽  
Yunjin Zhang ◽  
Shenghan Su ◽  
Qingrui Zhao ◽  
...  
Keyword(s):  
Stearic Acid ◽  
Molecular Mechanisms ◽  
High Throughput Sequencing ◽  
Luciferase Reporter ◽  
Sequencing Analysis ◽  
Protective Effects ◽  
Β Cells ◽  
Β Cell ◽  
Shrna Expression ◽  
High Stearic Acid

Long-term consumption of a high-fat diet increases the circulating concentration of stearic acid (SA), which has a potent toxic effect on β-cells, but the underlying molecular mechanisms of this action have not been fully elucidated. Here, we evaluated the role of lncRNA TCONS_00077866 (lnc866) in SA-induced β<i>-</i>cell inflammation. lnc866 was selected for study because lncRNA high-throughput sequencing analysis demonstrated it to have the largest fold-difference in expression of five lncRNAs that were affected by SA treatment. Knockdown of lnc866 by virus-mediated shRNA expression in mice or by Smart Silencer in mouse pancreatic β-TC6 cells significantly inhibited the SA-induced reduction in insulin secretion and β-cell inflammation. According to lncRNA-microRNA (miRNAs)-mRNA co-expression network analysis and luciferase reporter assays, lnc866 directly bound to miR-297b-5p, thereby preventing it from reducing the expression of its target serum amyloid A3 (SAA3). Furthermore, overexpression of miR-297b-5p or inhibition of SAA3 also had marked protective effects against the deleterious effects of SA in β-TC6 cells and mouse islets. In conclusion, lnc866 silencing ameliorates SA-induced β<i>-</i>cell inflammation by targeting the miR-297b-5p/SAA3 axis. lnc866 inhibition may represent a new strategy to protect β-cells against the effects of SA during the development of type 2 diabetes.

Sign in / Sign up

Export Citation Format

Share Document