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Gonuguntla S, Humphrey RK, Gorantla A, Hao E, Jhala US. Stress-induced pseudokinase TRB3 augments IL1β signaling by interacting with Flightless homolog 1. J Biol Chem 2023; 299:104803. [PMID: 37172723 PMCID: PMC10432976 DOI: 10.1016/j.jbc.2023.104803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 04/20/2023] [Accepted: 04/22/2023] [Indexed: 05/15/2023] Open
Abstract
Interleukin-1β is one of the most potent inducers of beta cell inflammation in the lead-up to type 1 diabetes. We have previously reported that IL1β-stimulated pancreatic islets from mice with genetic ablation of stress-induced pseudokinase TRB3(TRB3KO) show attenuated activation kinetics for the MAP3K MLK3 and JNK stress kinases. However, JNK signaling constitutes only a portion of the cytokine-induced inflammatory response. Here we report that TRB3KO islets also show a decrease in amplitude and duration of IL1β-induced phosphorylation of TAK1 and IKK, kinases that drive the potent NF-κB proinflammatory signaling pathway. We observed that TRB3KO islets display decreased cytokine-induced beta cell death, preceded by a decrease in select downstream NF-κB targets, including iNOS/NOS2 (inducible nitric oxide synthase), a mediator of beta cell dysfunction and death. Thus, loss of TRB3 attenuates both pathways required for a cytokine-inducible, proapoptotic response in beta cells. In order to better understand the molecular basis of TRB3-enhanced, post-receptor IL1β signaling, we interrogated the TRB3 interactome using coimmunoprecipitation followed by mass spectrometry to identify immunomodulatory protein Flightless homolog 1 (Fli1) as a novel, TRB3-interacting protein. We show that TRB3 binds and disrupts Fli1-dependent sequestration of MyD88, thereby increasing availability of this most proximal adaptor required for IL1β receptor-dependent signaling. Fli1 sequesters MyD88 in a multiprotein complex resulting in a brake on the assembly of downstream signaling complexes. By interacting with Fli1, we propose that TRB3 lifts the brake on IL1β signaling to augment the proinflammatory response in beta cells.
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Affiliation(s)
- Sumati Gonuguntla
- Pediatric Diabetes Research Center, University of California San Diego, La Jolla, California, USA
| | - Rohan K Humphrey
- Pediatric Diabetes Research Center, University of California San Diego, La Jolla, California, USA
| | - Akshita Gorantla
- Pediatric Diabetes Research Center, University of California San Diego, La Jolla, California, USA
| | - Ergeng Hao
- Pediatric Diabetes Research Center, University of California San Diego, La Jolla, California, USA
| | - Ulupi S Jhala
- Pediatric Diabetes Research Center, University of California San Diego, La Jolla, California, USA.
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2
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Wang W, An LP, Li YF, An R, Bian Z, Liu WZ, Song QH, Li AY. Alpha-lipoic acid ameliorates H 2O 2-induced human vein endothelial cells injury via suppression of inflammation and oxidative stress. Biosci Biotechnol Biochem 2020; 84:2253-2263. [PMID: 32787513 DOI: 10.1080/09168451.2020.1802221] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The study was aimed to investigate the effect of alpha-lipoic acid (ALA) on human umbilical vein endothelial cells (HUVECs) injury induced by hydrogen peroxide (H2O2) and to explore its possible mechanisms. We established the H2O2-induced HUVECs injury model and the ALA treatment groups in which HUVECs were co-incubated with H2O2 (250 μmol/L) and different final concentrations of ALA (100,200,400 μmol/L) for 48 h. Cell survival rate assay and LDH activity assay were carried out. The levels of related proteins were performed by Western Blot. We observed that H2O2 administration resulted in an increase in the LDH activity and a decrease in cell survival rate. The expression levels of Nox4, Bax, NF-κB p65, Caspase-9, Caspase-3, iNOS, VCAM-1 and ICAM-1 were up-regulated, while the expression level of Bcl-2 was down-regulated. All these factors were significantly improved by ALA treatment. In brief, ALA treatment ameliorates H2O2-induced HUVECs damage by inhibiting inflammation and oxidative stress.
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Affiliation(s)
- Wei Wang
- Hebei Key Laboratory of Chinese Medicine Research on Cardio-Cerebrovascular Disease and Department of Biochemistry and Molecular Biology, College of Basic Medicine, Hebei University of Chinese Medicine , Shijiazhuang, PR China
| | - Li-Ping An
- Hebei Key Laboratory of Chinese Medicine Research on Cardio-Cerebrovascular Disease and Department of Biochemistry and Molecular Biology, College of Basic Medicine, Hebei University of Chinese Medicine , Shijiazhuang, PR China
| | - Yun-Feng Li
- Hebei Key Laboratory of Chinese Medicine Research on Cardio-Cerebrovascular Disease and Department of Biochemistry and Molecular Biology, College of Basic Medicine, Hebei University of Chinese Medicine , Shijiazhuang, PR China
| | - Ran An
- Hebei Key Laboratory of Chinese Medicine Research on Cardio-Cerebrovascular Disease and Department of Biochemistry and Molecular Biology, College of Basic Medicine, Hebei University of Chinese Medicine , Shijiazhuang, PR China
| | - Zhe Bian
- Experiment Center, Hebei University of Chinese Medicine , Shijiazhuang, P. R. China
| | - Wei-Zhe Liu
- Hebei Key Laboratory of Chinese Medicine Research on Cardio-Cerebrovascular Disease and Department of Biochemistry and Molecular Biology, College of Basic Medicine, Hebei University of Chinese Medicine , Shijiazhuang, PR China
| | - Qiu-Hang Song
- Hebei Key Laboratory of Chinese Medicine Research on Cardio-Cerebrovascular Disease and Department of Biochemistry and Molecular Biology, College of Basic Medicine, Hebei University of Chinese Medicine , Shijiazhuang, PR China
| | - Ai-Ying Li
- Hebei Key Laboratory of Chinese Medicine Research on Cardio-Cerebrovascular Disease and Department of Biochemistry and Molecular Biology, College of Basic Medicine, Hebei University of Chinese Medicine , Shijiazhuang, PR China.,Hebei Higher Education Institute Applied Technology Research Center on TCM Formula Preparation , Shijiazhuang, PR China
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Baena-Nieto G, Lomas-Romero IM, Mateos RM, Leal-Cosme N, Perez-Arana G, Aguilar-Diosdado M, Segundo C, Lechuga-Sancho AM. Ghrelin mitigates β-cell mass loss during insulitis in an animal model of autoimmune diabetes mellitus, the BioBreeding/Worcester rat. Diabetes Metab Res Rev 2017; 33. [PMID: 27103341 DOI: 10.1002/dmrr.2813] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Revised: 03/06/2016] [Accepted: 04/07/2016] [Indexed: 12/24/2022]
Abstract
BACKGROUND Ghrelin is a peptide hormone with pleiotropic effects. It stimulates cell proliferation and inhibits apoptosis-mediated cell death. It prevents diabetes mellitus in several models of chemical, surgical and biological toxic insults to pancreas in both in vivo and in vitro models and promotes glucose-stimulated insulin secretion under cytotoxic conditions. It has not yet been tested in vivo in an autoimmune model of diabetes with a persistent insult to the β-cell. Given the immunomodulating effects of ghrelin and its trophic effects on β-cells, we hypothesized that ghrelin treatment during the early stages of insulitis would delay diabetes onset. METHODS BioBreeding/Worcester male rats received ghrelin (10 ng/kg/day) before insulitis development. Glucose metabolism was characterized by glucose and insulin tolerance tests. β-cell mass, islet area, islet number, β-cell clusters, proliferation and apoptosis and degree of insulitis were analysed by histomorphometry. A Kaplan-Meier survival curve was plotted and analysed applying the log-rank (Mantel-Cox) test. RESULTS Ghrelin treatment significantly reduced the probability of developing diabetes in our model (p < 0.0001). It decreased islet infiltration and partially prevented β-cell mass loss, enabling the maintenance of β-cell neogenesis and proliferation rates. Furthermore, ghrelin treatment did not induce any metabolic perturbations. CONCLUSIONS These findings support the hypothesis that ghrelin delays the development of autoimmune diabetes by attenuating insulitis and supporting β-cell mass. GENERAL SIGNIFICANCE Ghrelin promotes β-cell viability and function through diverse mechanisms that may have significant implications for diabetes prevention, therapy and also transplant success of both islets and complete pancreas. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- Gloria Baena-Nieto
- Department of Endocrinology and Nutrition, Puerta del Mar University Hospital, Cadiz, Spain
- Research Unit, Puerta del Mar University Hospital, Cadiz, Spain
| | - Isabel M Lomas-Romero
- Research Unit, Puerta del Mar University Hospital, Cadiz, Spain
- Andalusian Cellular Reprogramming Laboratory, Sevilla, Spain
| | - Rosa M Mateos
- Research Unit, Puerta del Mar University Hospital, Cadiz, Spain
- Department of Biotechnology, Biomedicine and Public Health, Cadiz University Medical School, Cadiz, Spain
| | - Noelia Leal-Cosme
- Department of Child and Mother Health and Radiology, Cadiz University Medical School, Cadiz, Spain
| | | | | | - Carmen Segundo
- "Salus Infirmorum" Faculty of Nursing, Cadiz University, Cadiz, Spain
| | - Alfonso M Lechuga-Sancho
- Research Unit, Puerta del Mar University Hospital, Cadiz, Spain
- Department of Child and Mother Health and Radiology, Cadiz University Medical School, Cadiz, Spain
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Protective Effects of Lactobacillus plantarum NDC 75017 Against Lipopolysaccharide-Induced Liver Injury in Mice. Inflammation 2014; 37:1599-607. [DOI: 10.1007/s10753-014-9886-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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5
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Cheng G, Zhao Y, Li H, Wu Y, Li X, Han Q, Dai C, Li Y. Forsythiaside attenuates lipopolysaccharide-induced inflammatory responses in the bursa of Fabricius of chickens by downregulating the NF-κB signaling pathway. Exp Ther Med 2013; 7:179-184. [PMID: 24348786 PMCID: PMC3861409 DOI: 10.3892/etm.2013.1378] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2013] [Accepted: 10/23/2013] [Indexed: 12/27/2022] Open
Abstract
Forsythiaside, a phenylethanoside product isolated from air-dried fruits of Forsythia suspensa, has been demonstrated to exhibit antioxidant, antibacterial and anti-inflammatory activities in vitro. However, its mechanism and the effects of lipopolysaccharide (LPS)-induced injury on the bursa of Fabricius (BF) of chickens are poorly understood. The present study aimed to investigate the anti-inflammatory effects of forsythiaside on LPS-induced acute inflammation. In addition, the potential molecular mechanisms of forsythiaside were analyzed in the BF, a special immune organ in chickens. Forty 15-day-old chickens were randomly divided into control, LPS and LPS plus forsythiaside (30 or 60 mg/kg) groups (n=10 for each group). In the LPS plus forsythiaside (30 or 60 mg/kg) groups, the chickens were orally administered with forsythiaside at doses of 30 and 60 mg/kg for seven days. At 21 days old, the chickens were intravenously injected with 200 μg/kg body weight LPS. Chickens in the control and LPS groups were only administered with vehicle or LPS, respectively, at day 21. At 3 h post-injection, the body temperature and nitric oxide (NO) levels were analyzed. In addition, the levels and mRNA expression of pro-inflammatory cytokines, including tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and IL-1β, and the mRNA expression of nuclear factor-κB (NF-κB), cyclooxygenase-2 (COX-2) and inducible NO synthase (iNOS), were examined in the BFs isolated from the chickens. The results revealed that forsythiaside was able to attenuate the LPS-induced inflammatory responses in the BFs of the chickens. The mechanisms by which forsythiaside exerted its anti-inflammatory effect were found to correlate with the inhibition of IL-6, IL-1β, TNF-α and COX-2 production, via the inactivation of NF-κB, indicating that the NF-κB-iNOS-NO signaling pathway may be important in this process.
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Affiliation(s)
- Guangdong Cheng
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, Heilongjiang 150030, P.R. China ; College of Life Science, Jiamusi University, Jiamusi, Heilongjiang 154007, P.R. China
| | - Yulian Zhao
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, Heilongjiang 150030, P.R. China
| | - He Li
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, Heilongjiang 150030, P.R. China
| | - Yue Wu
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, Heilongjiang 150030, P.R. China
| | - Xianxian Li
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, Heilongjiang 150030, P.R. China
| | - Qiang Han
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, Heilongjiang 150030, P.R. China
| | - Chongshan Dai
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, Heilongjiang 150030, P.R. China
| | - Yanhua Li
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, Heilongjiang 150030, P.R. China
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Cumaoğlu A, Ari N, Kartal M, Karasu Ç. Polyphenolic extracts from Olea europea L. protect against cytokine-induced β-cell damage through maintenance of redox homeostasis. Rejuvenation Res 2011; 14:325-34. [PMID: 21745095 DOI: 10.1089/rej.2010.1111] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Various pancreatic β-cell stressors, including cytokines, are known to induce oxidative stress, resulting in apoptotic/necrotic cell death and inhibition of insulin secretion. Traditionally, olive leaves or fruits are used for treating diabetes, but the cellular mechanism(s) of their effects are not known. We examined the effects of Olea europea L. (olive) leaf and fruit extracts and their component oleuropein on cytokine-induced β-cell toxicity. INS-1, an insulin-producing β-cell line, was preincubated with or without increasing concentrations of olive leaf or fruit extract or oleuropein for 24 hr followed by exposure to a cytokine cocktail containing 0.15 ng/mL interleukin-1β (IL-1β), 1 ng/mL interferon-γ (IFN-γ), and 1 ng/mL tumor necrosis factor-α (TNF-α) for 6 hr. The cytotoxicity was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) testing. Apoptosis was quantified by detecting acridine orange/ethidium bromide-stained condensed nuclei under a fluorescent microscope. The cells exposed to cytokines had a higher apoptotic rate, a decreased viability (MTT), and an increased caspase 3/7 activity. Both extracts and oleuropein partially increased the proportion of living cells and improved the viability of cells after cytokines. The protective effects of extracts on live cell viability were mediated through the suppression of caspase 3/7 activity. Oleuropein did not decrease the amount of both apoptotic and necrotic cells, whereas extracts significantly protected cells against cytokine-induced death. Cytokines led to an increase in reactive oxygen species (ROS) generation and inhibited glutathione level, superoxide dismutase activity, and insulin secretion in INS-1. Insulin secretion was almost completely protected by leaf extract, but was partially affected by fruit extract or oleuropein. Neither cytokines nor olive derivatives had a significant effect on cellular cytochrome c release and catalase activity. Moreover, the cells incubated with each extract or oleuropein showed a significant reduction in cytokine-induced ROS production and ameliorated abnormal antioxidant defense. The molecular mechanism by which olive polyphenols inhibit cytokine-mediated β-cell toxicity appears to be involving the maintenance of redox homeostasis.
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Affiliation(s)
- Ahmet Cumaoğlu
- Department of Medical Biochemistry, Gazi University, Ankara, Turkey
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Impaired mitochondrial respiratory functions and oxidative stress in streptozotocin-induced diabetic rats. Int J Mol Sci 2011; 12:3133-47. [PMID: 21686174 PMCID: PMC3116180 DOI: 10.3390/ijms12053133] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2011] [Revised: 04/11/2011] [Accepted: 04/29/2011] [Indexed: 12/19/2022] Open
Abstract
We have previously shown a tissue-specific increase in oxidative stress in the early stages of streptozotocin (STZ)-induced diabetic rats. In this study, we investigated oxidative stress-related long-term complications and mitochondrial dysfunctions in the different tissues of STZ-induced diabetic rats (>15 mM blood glucose for 8 weeks). These animals showed a persistent increase in reactive oxygen and nitrogen species (ROS and RNS, respectively) production. Oxidative protein carbonylation was also increased with the maximum effect observed in the pancreas of diabetic rats. The activities of mitochondrial respiratory enzymes ubiquinol: cytochrome c oxidoreductase (Complex III) and cytochrome c oxidase (Complex IV) were significantly decreased while that of NADH:ubiquinone oxidoreductase (Complex I) and succinate:ubiquinone oxidoreductase (Complex II) were moderately increased in diabetic rats, which was confirmed by the increased expression of the 70 kDa Complex II sub-unit. Mitochondrial matrix aconitase, a ROS sensitive enzyme, was markedly inhibited in the diabetic rat tissues. Increased expression of oxidative stress marker proteins Hsp-70 and HO-1 was also observed along with increased expression of nitric oxide synthase. These results suggest that mitochondrial respiratory complexes may play a critical role in ROS/RNS homeostasis and oxidative stress related changes in type 1 diabetes and may have implications in the etiology of diabetes and its complications.
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Abstract
Cytoprotective gene transfer to pancreatic islet β cell s may prove useful in preventing their destruction and prolonging islet graft survival after transplantation in patients with type 1 diabetes mellitus. A host of therapeutically relevant transgenes may potentially be incorporated into an appropriate gene delivery vehicle and used for islet modification. To examine this, we utilised a robust model of cytokine-induced β cell pathophysiology. Using this model, it is clear that antioxidant gene transfer confers no cytoprotective benefit. In contrast, we demonstrated that gene-based approaches to inhibit the activation of NF-κBNF-κB following cytokine exposure harbours therapeutic utility in preserving islet β cell viability in the face of cytokine toxicity. We identified that NF-κB-dependent induction of iNOSiNOS is a critical determinant of β cell fate following cytokine exposure. Having identified the pivotal role of iNOS activation in cytokine-induced β cell pathophysiology, lentiviral vectors may be used to efficiently deliver small interfering RNARNA molecules to confer efficient iNOS gene silencing. We have shown that lentiviral vector-based shRNA delivery holds significant promise in preserving β cell viability following cytotoxic cytokine exposure.
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Zhang X, Wang Z, Huang Y, Wang J. Effects of chronic administration of alogliptin on the development of diabetes and β-cell function in high fat diet/streptozotocin diabetic mice. Diabetes Obes Metab 2011; 13:337-47. [PMID: 21205126 DOI: 10.1111/j.1463-1326.2010.01354.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
AIM Alogliptin is a potent and highly selective dipeptidyl peptidase-4 (DPP-4) inhibitor. The aim of this study was to determine its effects on glucose control and pancreas islet function and to identify the underlying molecular mechanisms after chronic administration, in a non-genetic mouse model of type 2 diabetes. METHODS Alogliptin (5, 15 and 45 mg/kg) was orally administered to high fat diet/streptozotocin (HFD/STZ) diabetic mice daily for 10 weeks. Postprandial and 6-h fasting blood glucose levels, blood A1C level, oral glucose tolerance and pancreas insulin content were measured during or after the treatment period. Alogliptin plasma concentration was determined by an LC/MS/MS method. Islet morphology and architectural changes were evaluated with immunohistochemical analysis. Islet endocrine secretion ability was assessed by measuring insulin release from isolated islets which were challenged with 16 mM glucose and 30 mM potassium chloride, respectively. Gene expression profiles of the pancreas were analysed using the mouse diabetes RT(2) Profiler PCR array which contains 84 genes related to the onset, development and progression of diabetes. RESULTS Alogliptin showed dose-dependent reduction of postprandial and fasting blood glucose levels and blood A1C levels. Glucose clearance ability and pancreas insulin content were both increased. Alogliptin significantly restored the β-cell mass and islet morphology, thus preserving islet function of insulin secretion. Expression of 10 genes including Ins1 was significantly changed in the pancreas of diabetic mice. Chronic alogliptin treatment completely or partially reversed the abnormalities in gene expression. CONCLUSIONS Chronic treatment of alogliptin improved glucose control and facilitated restoration of islet architecture and function in HFD/STZ diabetic mice. The gene expression profiles suggest that the underlying molecular mechanisms of β-cell protection by alogliptin may involve alleviating endoplasmic reticulum burden and mitochondria oxidative stress, increasing β-cell differentiation and proliferation, enhancing islet architecture remodelling and preserving islet function.
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Affiliation(s)
- X Zhang
- Department of Pharmaceutical Sciences, College of Pharmacy, Western University of Health Sciences, 309 E. Second Street, Pomona, CA 91766, USA
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10
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Roeske-Nielsen A, Dalgaard LT, Månsson JE, Buschard K. The glycolipid sulfatide protects insulin-producing cells against cytokine-induced apoptosis, a possible role in diabetes. Diabetes Metab Res Rev 2010; 26:631-8. [PMID: 20886661 DOI: 10.1002/dmrr.1130] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/09/2009] [Revised: 06/23/2010] [Accepted: 08/19/2010] [Indexed: 12/13/2022]
Abstract
AIMS/HYPOTHESIS Cytokine-induced apoptosis is recognised as a major cause of the decline in β-cell mass that ultimately leads to type 1 diabetes mellitus. Interleukin-1β, interferon-γ and tumour necrosis factor-α in conjunction initiate a series of events that lead to β-cell apoptosis; important among these is NO production. The glycosphingolipid sulfatide is present in β-cells in the secretory granules in varying amounts and is secreted together with insulin. We now investigate whether sulfatide is able to protect insulin-producing cells against the pro-apoptotic effect of interleukin-1β, interferon-γ and tumour necrosis factor-α. METHODS INS-1E cells and genuine rat islets were incubated for 24 h exposed to interleukin-1β, interferon-γ and tumour necrosis factor-α with or without sulfatide. The production of NO was monitored and the number of apoptotic cells was determined using terminal deoxynucleotidyl transferase-mediated dUTP Nick-End labelling and caspase-3/7 activity assays. In addition, the amount of iNOS mRNA was determined using real-time quantitative polymerase chain reaction. RESULTS Cytokine-induced apoptosis was reduced to 27% of cytokine-treated controls with 30 µmol/L sulfatide treatment (p < 0.01). Likewise, sulfatide in concentrations of 3-30 µmol/L decreased NO production in a dose-dependent manner to 19-40% of cytokine-treated controls (overall p = 0.0007). The level of iNOS mRNA after cytokine exposure was reduced to 55% of cytokine-treated controls with 30 µmol/L of sulfatide. CONCLUSIONS/INTERPRETATION In the present study, we report the ability of sulfatide to significantly reduce apoptosis, cellular leakage and NO production in insulin-producing cells. Data suggest this is not due to induction of β-cell rest. Our findings indicate a possible implication for sulfatide in the pathogenesis of diabetes.
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Affiliation(s)
- A Roeske-Nielsen
- Bartholin Institute, Rigshospitalet, Blegdamsvej 9, Copenhagen, Denmark.
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11
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Drews G, Krippeit-Drews P, Düfer M. Oxidative stress and beta-cell dysfunction. Pflugers Arch 2010; 460:703-18. [PMID: 20652307 DOI: 10.1007/s00424-010-0862-9] [Citation(s) in RCA: 188] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2010] [Revised: 06/23/2010] [Accepted: 06/25/2010] [Indexed: 12/11/2022]
Abstract
Diabetes mellitus type 1 and 2 (T1DM and T2DM) are complex multifactorial diseases. Loss of beta-cell function caused by reduced secretory capacity and enhanced apoptosis is a key event in the pathogenesis of both diabetes types. Oxidative stress induced by reactive oxygen and nitrogen species is critically involved in the impairment of beta-cell function during the development of diabetes. Because of their low antioxidant capacity, beta-cells are extremely sensitive towards oxidative stress. In beta-cells, important targets for an oxidant insult are cell metabolism and K(ATP) channels. The oxidant-evoked alterations of K(ATP) channel activity seem to be critical for oxidant-induced dysfunction because genetic ablation of K(ATP) channels attenuates the effects of oxidative stress on beta-cell function. Besides the effects on metabolism, interference of oxidants with mitochondria induces key events in apoptosis. Consequently, increasing antioxidant defence is a promising strategy to delay beta cell failure in (pre)-diabetic patients or during islet transplantation. Knock-out of K(ATP) channels has beneficial effects on oxidant-induced inhibition of insulin secretion and cell death. Interestingly, these effects can be mimicked by sulfonylureas that have been used in the treatment of T2DM for many years. Loss of functional K(ATP) channels leads to up-regulation of antioxidant enzymes, a process that depends on cytosolic Ca(2+). These observations are of great importance for clinical intervention because they show a possibility to protect beta-cells at an early stage before dramatic changes of the secretory capacity and loss of cell mass become manifest and lead to glucose intolerance or even overt diabetes.
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Affiliation(s)
- Gisela Drews
- Department of Pharmacology and Clinical Pharmacy, University of Tübingen, Auf der Morgenstelle 8, Tübingen, Germany.
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12
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Lacraz G, Figeac F, Movassat J, Kassis N, Portha B. Diabetic GK/Par rat beta-cells are spontaneously protected against H2O2-triggered apoptosis. A cAMP-dependent adaptive response. Am J Physiol Endocrinol Metab 2010; 298:E17-27. [PMID: 19843875 DOI: 10.1152/ajpendo.90871.2008] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The alteration of the beta-cell population in the Goto-Kakizaki rat (GK/Par line), a model of spontaneous type 2 diabetes, has been ascribed to significantly decreased beta-cell replication and neogenesis, while beta-cell apoptosis is surprisingly not enhanced and remains in the normal range. To gain insight into the mechanisms by which those beta-cells are protected from death, we studied ex vivo the apoptotic activity and the expression of a large set of pro/antiapoptotic and pro/antioxidant genes in GK/Par islet cells. This was done in vitro in freshly isolated islets as well as in response to culture conditions and calibrated reactive oxygen species (ROS) exposure (i.e., H2O2). We also investigated the intracellular mechanisms of the diabetic beta-cell response to ROS, the role if any of the intracellular cAMP metabolism, and finally the kinetic of ROS response, taking advantage of the GK/Par rat normoglycemia until weaning. Our results show that the peculiar GK/Par beta-cell phenotype was correlated with an increased expression of a large panel of antioxidant genes as well as pro/antiapoptotic genes. We demonstrate that such combination confers resistance to cytotoxic H2O2 exposure in vitro, raising the possibility that at least some of the activated stress/defense genes have protective effects against H2O2-triggered beta-cell death. We also present some evidence that the GK/Par beta-cell resistance to H2O2 is at least partly cAMP dependent. Finally, we show that such a phenotype is not innate but is spontaneously acquired after diabetes onset as the result of an adaptive response to the diabetic environment.
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MESH Headings
- Adaptation, Physiological/physiology
- Animals
- Apoptosis/drug effects
- Apoptosis/physiology
- Apoptosis Regulatory Proteins/genetics
- Apoptosis Regulatory Proteins/metabolism
- Cell Division/physiology
- Cells, Cultured
- Cyclic AMP/metabolism
- Cyclin D1/genetics
- Cyclin D1/metabolism
- Diabetes Mellitus, Type 2/metabolism
- Diabetes Mellitus, Type 2/pathology
- Disease Models, Animal
- Heme Oxygenase-1/genetics
- Heme Oxygenase-1/metabolism
- Hydrogen Peroxide/pharmacology
- Hypoxia-Inducible Factor 1, alpha Subunit/genetics
- Hypoxia-Inducible Factor 1, alpha Subunit/metabolism
- Insulin-Secreting Cells/metabolism
- Insulin-Secreting Cells/pathology
- Male
- Oxidants/pharmacology
- Proto-Oncogene Proteins c-myc/genetics
- Proto-Oncogene Proteins c-myc/metabolism
- RNA, Messenger/metabolism
- Rats
- Rats, Mutant Strains
- Rats, Wistar
- Reactive Oxygen Species/metabolism
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Affiliation(s)
- Grégory Lacraz
- Laboratoire Biologie et Pathologie du Pancréas Endocrine, Unité Biologie Fonctionnelle et Adaptive, Equipe 1, Université Paris-Diderot et CNRS EAC-4413, Paris, France
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13
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Inducible nitric oxide synthase immunoreactivity in healthy rat pancreas. Folia Histochem Cytobiol 2008; 46:213-7. [DOI: 10.2478/v10042-008-0032-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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Inducible nitric oxide synthase-nitric oxide plays an important role in acute and severe hypoxic injury to pancreatic beta cells. Transplantation 2008; 85:323-30. [PMID: 18301327 DOI: 10.1097/tp.0b013e31816168f9] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
BACKGROUND Islet transplantation is a potential strategy to cure type 1 diabetes mellitus. However, a substantial part of the islet graft becomes nonfunctional due to several factors including hypoxia. However, the precise mechanism of cell damage is largely unknown in hypoxic exposure to pancreatic beta cells. The aim of the present study was to investigate whether acute and severe hypoxic injury could involve inducible nitric oxide synthase (iNOS)-nitric oxide (NO) signaling in beta cells. METHODS The rat beta cell line (INS-1) and primary rat islets were incubated in an anoxic chamber. Cell viability was determined by propium iodide staining or cell counting kit. The expression of iNOS mRNA and protein was examined using reverse-transcription polymerase chain reaction and Western blot analysis. NO production was measured as nitrite accumulation by Griess reagent method. RESULTS After hypoxic exposure, marked cell death occurred in INS-1 cells and rat islets, accompanied by increase in activated caspase-3 expression. NO production was increased in the culture medium in a time-dependent manner. Increase in expression of iNOS mRNA and protein was found. Pretreatment with a selective iNOS inhibitor, 1400W, significantly prevented cell death during hypoxia. In addition, hypoxia activated c-Jun N-terminal kinase (JNK) significantly, but the addition of 1400W inhibited hypoxia-induced JNK phosphorylation. CONCLUSIONS Our data suggest that iNOS-NO plays an important role in acute and severe hypoxic injury to pancreatic beta cells. Therefore, iNOS-NO might be a potential therapeutic target for preserving beta cell survival in islet transplantation through prevention of hypoxia-mediated cell death.
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Li F, Mahato RI. iNOS Gene Silencing Prevents Inflammatory Cytokine-Induced β-Cell Apoptosis. Mol Pharm 2008; 5:407-17. [DOI: 10.1021/mp700145f] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Feng Li
- Department of Pharmaceutical Sciences, University of Tennessee Health Science Center, Memphis, Tennessee
| | - Ram I. Mahato
- Department of Pharmaceutical Sciences, University of Tennessee Health Science Center, Memphis, Tennessee
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Holohan C, Szegezdi E, Ritter T, O'Brien T, Samali A. Cytokine-induced beta-cell apoptosis is NO-dependent, mitochondria-mediated and inhibited by BCL-XL. J Cell Mol Med 2007; 12:591-606. [PMID: 18081694 PMCID: PMC3822546 DOI: 10.1111/j.1582-4934.2007.00191.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Pro-inflammatory cytokines are implicated as the main mediators of beta-cell death during type 1 diabetes but the exact mechanisms remain unknown. This study examined the effects of interleukin-1beta (IL-1beta), interferon-gamma (IFNgamma) and tumour necrosis factor alpha (TNFalpha) on a rat insulinoma cell line (RIN-r) in order to identify the core mechanism of cytokine-induced beta-cell death. Treatment of cells with a combination of IL-1beta and IFNgamma (IL-1beta/IFNgamma)induced apoptotic cell death. TNFalpha neither induced beta-cell death nor did it potentiate the effects of IL-1beta, IFNgamma or IL-1beta/IFNgamma . The cytotoxic effect of IL-1beta/IFNgamma was associated with the expression of inducible nitric oxide synthase (iNOS) and production of nitric oxide. Adenoviral-mediated expression of iNOS (AdiNOS) alone was sufficient to induce caspase activity and apoptosis. The broad range caspase inhibitor, Boc-D-fmk, blocked IL-1beta/IFNgamma -induced caspase activity, but not nitric oxide production nor cell death. However, pre-treatment with L-NIO, a NOS inhibitor, prevented nitric oxide production, caspase activity and reduced apoptosis. IL-1beta/IFNgamma -induced apoptosis was accompanied by loss of mitochondrial membrane potential, release of cytochrome c and cleavage of pro-caspase-9, -7 and -3. Transduction of cells with Ad-Bcl-X(L) blocked both iNOS and cytokine-mediated mitochondrial changes and subsequent apoptosis, downstream of nitric oxide. We conclude that cytokine-induced nitric oxide production is both essential and sufficient for caspase activation and beta-cell death, and have identified Bcl-X(L) as a potential target to combat beta-cell apoptosis.
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Affiliation(s)
- C Holohan
- Department of Biochemistry, National University of Ireland Galway, Galway, Ireland
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McCabe C, O'Brien T. The Rational Design of β Cell Cytoprotective Gene Transfer Strategies: Targeting Deleterious iNOS Expression. Mol Biotechnol 2007; 37:38-47. [PMID: 17914162 DOI: 10.1007/s12033-007-0049-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/1999] [Revised: 11/30/1999] [Accepted: 11/30/1999] [Indexed: 12/27/2022]
Abstract
Islet transplantation represents a promising therapeutic strategy for the treatment of type 1 diabetes mellitus (T1DM) [Hakim and Papalois (Ann Ital Chir 75:1-7, 2004); Jaeckel et al. (Internist (Berl) 45:1268-1280, 2004); Sutherland et al. (Transplant Proc 36:1697-1699, 2004)]. The insulin-secreting pancreatic beta cells of the islet allograft are, however, subject to recurrent immune-mediated damage. Principal among the molecular culprits involved in this destructive process is the proinflammatory cytokine IL-1beta. IL-1beta-induced beta cell destruction may be mediated by the generation of NO and/or ROS, although the relative importance of NO and ROS in this process remains unclear. This study broadly encompassed three arms of investigation: the first of these was geared toward the establishment of a robust in vitro cell system for the study of IL-1beta-induced pathophysiology; the second arm aimed to provide a comparative analysis of the gene transfer profiles of the three most commonly used gene transfer vehicles, namely plasmid vectors, adenoviral vectors, and lentiviral vectors, in the aforementioned cell system; the final arm aimed to screen an array of potentially cytoprotective gene transfer strategies incorporating the optimal gene transfer vectors. Briefly, we established an in vitro beta cell system that accurately reflected primary beta cell cytokine-induced pathophysiology. That is, IL-1beta exposure (100 U/ml) induced a time-dependent decrease in rat insulinoma (RIN) cell viability, which coincided with an induction in iNOS expression and nitrite accumulation. Gene transfer studies using plasmid, adenoviral, or lentiviral vectors underscored the superiority of viral vector-based gene transfer strategies for the manipulation of this beta cell line. Using these vectors, we provide evidence that NF-kappaB-based iNOS inhibition confers significant protection against IL-1beta-induced damage whereas antioxidant overexpression fails to provide protection. Conferred cytoprotection was associated with a suppression of iNOS expression and nitrite accumulation. From a therapeutic standpoint, gene transfer strategies employing efficient viral vectors to target iNOS activation may harbour therapeutic potential in preserving beta cell survival against proinflammatory cytokine exposure.
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Affiliation(s)
- Cillian McCabe
- Regenerative Medicine Institute, National Centre for Biomedical Engineering Sciences, National University of Ireland, Galway, Ireland
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McCabe C, O'Brien T. Beta cell cytoprotection using lentiviral vector-based iNOS-specific shRNA delivery. Biochem Biophys Res Commun 2007; 357:75-80. [PMID: 17407761 DOI: 10.1016/j.bbrc.2007.03.115] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2007] [Accepted: 03/13/2007] [Indexed: 12/22/2022]
Abstract
Cytokine-induced beta cell pathophysiology is characterised by the induction of iNOS expression. Inhibition of iNOS expression protects beta cells from cytokine-mediated destruction. The development of vector-based shRNA strategies capable of stably suppressing iNOS expression may provide a novel platform to protect beta cells from cytokine toxicity. In this report the utility of lentiviral shRNA vectors to silence iNOS expression was evaluated with respect to insulinoma cell viability, the induction of iNOS expression and the accumulation of nitrite in a cytokine-induced beta cell toxicity model. Here, we report for the first time on the use of lentiviral vector-based shRNA delivery to efficiently suppress the IL-1beta-mediated induction of iNOS expression, the accumulation of nitrite and provide significant protection against the cytotoxic effects of IL-1beta exposure. Moreover, non-specific knockdown of endogenous beta cell nNOS did not occur.
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