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1
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Pala K, Sun KX, Krogvold L, Dahl-Jørgensen K, Reddy S. Distribution of glutathione peroxidase-1 immunoreactive cells in pancreatic islets from type 1 diabetic donors and non-diabetic donors with and without islet cell autoantibodies is variable and independent of disease. Cell Tissue Res 2025; 400:255-271. [PMID: 40059238 DOI: 10.1007/s00441-025-03955-5] [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: 11/01/2024] [Accepted: 01/30/2025] [Indexed: 04/03/2025]
Abstract
During type 1 diabetes (T1D), oxidative stress in beta cells may cause early beta cell dysfunction and initiate autoimmunity. Mouse islets express lower levels of reactive oxygen species (ROS) clearing enzymes, such as glutathione peroxidase (GPX), superoxide dismutase (SOD) and catalase than several other tissues. It remains unclear if human beta cells show a similar deficiency during T1D or exhibit a higher degree of intrinsic resistance to oxidative stress. We compared islet cell distributions and determined graded intensities of glutathione peroxidase1 (GPX1), a key enzymatic mediator involved in detoxifying hydrogen peroxide, by applying combined immunohistochemistry for GPX1, insulin and glucagon, in pancreatic sections from new-onset T1D (group 1), non-diabetic autoantibody-negative (group 2), non-diabetic autoantibody-positive (group 3) and long-term diabetic (group 4) donors. Islets from all study groups demonstrated either uniform but graded staining intensities for GPX1 in almost all islet cells or strong staining in selective islet cells with weaker intensities in the remaining cells. GPX1 was present in selective glucagon cells and insulin cells, including in cells negative for both hormones, with stronger intensities in a higher percentage of glucagon than insulin cells. It was absent in a higher percentage of beta cells than glucagon cells independent of disease or autoantibody positivity. We conclude that a proportion of human beta cells and glucagon cells express GPX1 but show heterogeneity in its distribution and intensities, independent of disease or autoantibody status. Our studies highlight important differences in the expression of GPX1 in islet cell-types between mice and humans.
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Affiliation(s)
- Kaaj Pala
- Department of Molecular Medicine and Pathology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, 1023, New Zealand
| | - Kevin Xueying Sun
- Department of Molecular Medicine and Pathology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, 1023, New Zealand
| | - Lars Krogvold
- Division of Paediatric and Adolescent Medicine, Oslo University Hospital, Oslo, Norway
- Faculty of Dentistry, University of Oslo, Oslo, Norway
| | - Knut Dahl-Jørgensen
- Faculty of Dentistry, University of Oslo, Oslo, Norway
- Faculty of Medicine, University of Oslo, Oslo, Norway
- Oslo University Hospital, Oslo, Norway
| | - Shiva Reddy
- Department of Molecular Medicine and Pathology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, 1023, New Zealand.
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2
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Shahraki ZS, Karbalaei N, Nemati M. Improving effect of combined inorganic nitrate and nitric oxide synthase inhibitor on pancreatic oxidative stress and impaired insulin secretion in streptozotocin induced-diabetic rats. J Diabetes Metab Disord 2020; 19:353-362. [PMID: 32550186 DOI: 10.1007/s40200-020-00516-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Accepted: 03/11/2020] [Indexed: 12/16/2022]
Abstract
Purpose The aim of this study was to evaluate the effect of dietary nitrate on secretory function of pancreatic islet and oxidative stress status in streptozotocin (STZ) induced type 1 diabetes in absence or presence of nitric oxide synthase inhibitor (L-NAME). Methods Fifty adult male sprague-dawly rats were divided into 5 groups: controls (C), diabetes (D), diabetes+nitrate (DN), diabetes +L-NAME (D + Ln), and diabetes+nitrate+L-NAME (DN + Ln) for 45 days. The concentrations of sodium nitrate and L-NAME were respectively 80 mg/L in drinking water and 5 mg/kg intraperitoneally. Body weight gain, plasma levels of glucose and insulin, islet insulin secretion and content, lipid peroxidation and antioxidant status in the pancreas of rats were determined. Results Compared to control group, the body weight gain and plasma insulin level were significantly decreased and plasma glucose and pancreatic NO and MDA concentrations and antioxidant enzymes activities were significantly increased in the STZ diabetic rats. In the diabetic rats, nitrate alone significantly reduced plasma glucose and increased pancreatic SOD and GPx activity. Reduced plasma glucose, pancreatic MDA and NO concentrations and increased plasma insulin level and pancreatic islet insulin secretion were observed in D + Ln and DN + Ln groups. Antioxidant enzymes activities were increased in diabetic rats which received combination of nitrate and L-NAME. Conclusions Our results showed that nitrate without effect on pancreatic islet insulin content and secretion decreased the blood glucose and slightly moderate oxidative stress and its effects in the presence of L-NAME on glucose hemostasis and pancreatic insulin secretion higher than those of nitrate alone.
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Affiliation(s)
- Zahra Shabgard Shahraki
- Department of Physiology, Faculty of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Narges Karbalaei
- Department of Physiology, Faculty of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran.,Histomorphometry and Stereology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Marzieh Nemati
- Department of Physiology, Faculty of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
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3
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Wang Y, Xue J, Li Y, Zhou X, Qiao S, Han D. Telmisartan protects against high glucose/high lipid‐induced apoptosis and insulin secretion by reducing the oxidative and ER stress. Cell Biochem Funct 2019; 37:161-168. [PMID: 30907023 DOI: 10.1002/cbf.3383] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 01/14/2019] [Accepted: 01/29/2019] [Indexed: 12/17/2022]
Affiliation(s)
- Yan Wang
- Department of EndocrinologyThe First Hospital of Shanxi Medical University Taiyuan Shan Xi China
| | - Jingjing Xue
- Department of EndocrinologyThe First Hospital of Shanxi Medical University Taiyuan Shan Xi China
| | - Yan Li
- Department of EndocrinologyThe First Hospital of Shanxi Medical University Taiyuan Shan Xi China
| | - Xin Zhou
- Department of PathophysiologyShanxi Medical University Taiyuan Shan Xi China
| | - Shun Qiao
- Department of EndocrinologyThe First Hospital of Shanxi Medical University Taiyuan Shan Xi China
| | - Dewu Han
- Department of PathophysiologyShanxi Medical University Taiyuan Shan Xi China
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4
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Tyka K, Jörns A, Turatsinze JV, Eizirik DL, Lenzen S, Gurgul-Convey E. MCPIP1 regulates the sensitivity of pancreatic beta-cells to cytokine toxicity. Cell Death Dis 2019; 10:29. [PMID: 30631045 PMCID: PMC6328635 DOI: 10.1038/s41419-018-1268-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Revised: 10/29/2018] [Accepted: 12/05/2018] [Indexed: 12/20/2022]
Abstract
The autoimmune-mediated beta-cell death in type 1 diabetes (T1DM) is associated with local inflammation (insulitis). We examined the role of MCPIP1 (monocyte chemotactic protein–induced protein 1), a novel cytokine-induced antiinflammatory protein, in this process. Basal MCPIP1 expression was lower in rat vs. human islets and beta-cells. Proinflammatory cytokines stimulated MCPIP1 expression in rat and human islets and in insulin-secreting cells. Moderate overexpression of MCPIP1 protected insulin-secreting INS1E cells against cytokine toxicity by a mechanism dependent on the presence of the PIN/DUB domain in MCPIP1. It also reduced cytokine-induced Chop and C/ebpβ expression and maintained MCL-1 expression. The shRNA-mediated suppression of MCPIP1 led to the potentiation of cytokine-mediated NFκB activation and cytokine toxicity in human EndoC-βH1 beta-cells. MCPIP1 expression was very high in infiltrated beta-cells before and after diabetes manifestation in the LEW.1AR1-iddm rat model of human T1DM. The extremely high expression of MCPIP1 in clonal beta-cells was associated with a failure of the regulatory feedback-loop mechanism, ER stress induction and high cytokine toxicity. In conclusion, our data indicate that the expression level of MCPIP1 affects the susceptibility of insulin-secreting cells to cytokines and regulates the mechanism of beta-cell death in T1DM.
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Affiliation(s)
- Karolina Tyka
- Institute of Clinical Biochemistry, Hannover Medical School, 30625, Hannover, Germany
| | - Anne Jörns
- Institute of Clinical Biochemistry, Hannover Medical School, 30625, Hannover, Germany
| | - Jean-Valery Turatsinze
- ULB Center for Diabetes Research, Medical Faculty, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - Decio L Eizirik
- ULB Center for Diabetes Research, Medical Faculty, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - Sigurd Lenzen
- Institute of Clinical Biochemistry, Hannover Medical School, 30625, Hannover, Germany.,Institute of Experimental Diabetes Research, Hannover Medical School, Hannover, Germany
| | - Ewa Gurgul-Convey
- Institute of Clinical Biochemistry, Hannover Medical School, 30625, Hannover, Germany.
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5
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Danobeitia JS, Chlebeck PJ, Shokolenko I, Ma X, Wilson G, Fernandez LA. Novel Fusion Protein Targeting Mitochondrial DNA Improves Pancreatic Islet Functional Potency and Islet Transplantation Outcomes. Cell Transplant 2018; 26:1742-1754. [PMID: 29338388 PMCID: PMC5784523 DOI: 10.1177/0963689717727542] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Long-term graft survival is an ongoing challenge in the field of islet transplantation. With the growing demand for transplantable organs, therapies to improve organ quality and reduce the incidence of graft dysfunction are of paramount importance. We evaluated the protective role of a recombinant DNA repair protein targeted to mitochondria (Exscien I-III), as a therapeutic agent using a rodent model of pancreatic islet transplantation. We first investigated the effect of therapy on isolated rat islets cultured with pro-inflammatory cytokines (interleukin-1 β, interferon γ, and tumor necrosis factor α) for 48 h and documented a significant reduction in apoptosis by flow cytometry, improved viability by immunofluorescence, and conserved functional potency in vitro and in vivo in Exscien I-III-treated islets. We then tested the effect of therapy in systemic inflammation using a rat model of donor brain death (BD) sustained for a 6-h period. Donor rats were allocated to 4 groups: (non-BD + vehicle, non-BD + Exscien I-III, BD + vehicle, and BD + Exscien I-III) and treated with Exscien I-III (4 mg/kg) or vehicle 30 min after BD induction. Sham (non-BD)-operated animals receiving either Exscien I-III or vehicle served as controls. Islets purified from BD + Exscien I-III-treated donors showed a significant increase in glucose-stimulated insulin release in vitro when compared to islets from vehicle-treated counterparts. In addition, donor treatment with Exscien I-III attenuated the effects of BD and significantly improved the functional potency of transplanted islets in vivo. Our data indicate that mitochondrially targeted antioxidant therapy is a novel strategy to protect pancreas and islet quality from the deleterious effects of cytokines in culture and during the inflammatory response associated with donation after BD. The potential for rapid translation into clinical practice makes Exscien I-III an attractive therapeutic option for the management of brain-dead donors or as an additive to islets in culture after isolation setting.
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Affiliation(s)
- Juan S Danobeitia
- Division of Transplantation Madison, Department of Surgery, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA
| | - Peter J Chlebeck
- Division of Transplantation Madison, Department of Surgery, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA
| | - Inna Shokolenko
- Department of Allied Health, University of South Alabama, Mobile, Alabama, USA
| | - Xiaobo Ma
- Division of Transplantation Madison, Department of Surgery, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA
| | - Glenn Wilson
- Exscien Corporation, Mobile, Alabama, USA.,College of Medicine, University of South Alabama, Mobile, Alabama, USA
| | - Luis A Fernandez
- Division of Transplantation Madison, Department of Surgery, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA
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Xia EQ, Zhu SS, He MJ, Luo F, Fu CZ, Zou TB. Marine Peptides as Potential Agents for the Management of Type 2 Diabetes Mellitus-A Prospect. Mar Drugs 2017; 15:md15040088. [PMID: 28333091 PMCID: PMC5408234 DOI: 10.3390/md15040088] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 03/17/2017] [Accepted: 03/20/2017] [Indexed: 01/09/2023] Open
Abstract
An increasing prevalence of diabetes is known as a main risk for human health in the last future worldwide. There is limited evidence on the potential management of type 2 diabetes mellitus using bioactive peptides from marine organisms, besides from milk and beans. We summarized here recent advances in our understanding of the regulation of glucose metabolism using bioactive peptides from natural proteins, including regulation of insulin-regulated glucose metabolism, such as protection and reparation of pancreatic β-cells, enhancing glucose-stimulated insulin secretion and influencing the sensitivity of insulin and the signaling pathways, and inhibition of bioactive peptides to dipeptidyl peptidase IV, α-amylase and α-glucosidase activities. The present paper tried to understand the underlying mechanism involved and the structure characteristics of bioactive peptides responsible for its antidiabetic activities to prospect the utilization of rich marine organism proteins.
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Affiliation(s)
- En-Qin Xia
- Dongguan Key Laboratory of Environmental Medicine, School of Public Health, Guangdong Medical University, Dongguan 523808, China.
| | - Shan-Shan Zhu
- Dongguan Key Laboratory of Environmental Medicine, School of Public Health, Guangdong Medical University, Dongguan 523808, China.
| | - Min-Jing He
- Dongguan Key Laboratory of Environmental Medicine, School of Public Health, Guangdong Medical University, Dongguan 523808, China.
| | - Fei Luo
- Dongguan Key Laboratory of Environmental Medicine, School of Public Health, Guangdong Medical University, Dongguan 523808, China.
| | - Cheng-Zhan Fu
- Dongguan Key Laboratory of Environmental Medicine, School of Public Health, Guangdong Medical University, Dongguan 523808, China.
| | - Tang-Bin Zou
- Dongguan Key Laboratory of Environmental Medicine, School of Public Health, Guangdong Medical University, Dongguan 523808, China.
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7
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Jo HS, Cha HJ, Kim SJ, Yeo HJ, Cho SB, Park JH, Lee CH, Yeo EJ, Choi YJ, Eum WS, Choi SY. Tat-DJ-1 inhibits oxidative stress-mediated RINm5F cell death through suppression of NF-κB and MAPK activation. Med Chem Res 2016; 25:2589-2598. [PMID: 27818604 PMCID: PMC5075024 DOI: 10.1007/s00044-016-1698-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Accepted: 07/22/2016] [Indexed: 11/10/2022]
Abstract
Oxidative stress is highly involved in the development of diabetes mellitus by destruction of pancreatic β-cells. DJ-1 is an antioxidant protein and DJ-1 expression levels are known to be reduced in diabetes mellitus. Thus, we examined the effects of DJ-1 protein against oxidative stress-induced pancreatic β-cell (RINm5F) death using cell permeable wild-type and mutant-type (C106A) Tat-DJ-1 proteins, which both efficiently transduced into RINm5F cells. Intracellular stability of wild-type Tat-DJ-1 persisted two times longer than C106A Tat-DJ-1. Wild-type Tat-DJ-1 protein markedly protected cells from hydrogen peroxide-induced toxicities such as cell death, reactive oxygen species generation, and DNA fragmentation. Further, wild-type Tat-DJ-1 protein significantly inhibited hydrogen peroxide-induced activation of mitogen-activated protein kinases and NF-κB signaling. On the other hand, C106A Tat-DJ-1 protein did not show the same protective effects. These results indicate that wild-type Tat-DJ-1 inhibits oxidative stress-induced cellular toxicity and activation of mitogen-activated protein kinases and NF-κB signals in RINm5F cells. These results suggest that wild-type Tat-DJ-1 protein may be a potential therapeutic agent against diabetes mellitus or toward the prevention of pancreatic β-cell destruction.
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Affiliation(s)
- Hyo Sang Jo
- Department of Biomedical Science and Research Institute of Bioscience and Biotechnology, Hallym University, Chuncheon, 24252 Korea
| | - Hyun Ju Cha
- Department of Biomedical Science and Research Institute of Bioscience and Biotechnology, Hallym University, Chuncheon, 24252 Korea
| | - Sang Jin Kim
- Department of Biomedical Science and Research Institute of Bioscience and Biotechnology, Hallym University, Chuncheon, 24252 Korea
| | - Hyeon Ji Yeo
- Department of Biomedical Science and Research Institute of Bioscience and Biotechnology, Hallym University, Chuncheon, 24252 Korea
| | - Su Bin Cho
- Department of Biomedical Science and Research Institute of Bioscience and Biotechnology, Hallym University, Chuncheon, 24252 Korea
| | - Jung Hwan Park
- Department of Biomedical Science and Research Institute of Bioscience and Biotechnology, Hallym University, Chuncheon, 24252 Korea
| | - Chi Hern Lee
- Department of Biomedical Science and Research Institute of Bioscience and Biotechnology, Hallym University, Chuncheon, 24252 Korea
| | - Eun Ji Yeo
- Department of Biomedical Science and Research Institute of Bioscience and Biotechnology, Hallym University, Chuncheon, 24252 Korea
| | - Yeon Joo Choi
- Department of Biomedical Science and Research Institute of Bioscience and Biotechnology, Hallym University, Chuncheon, 24252 Korea
| | - Won Sik Eum
- Department of Biomedical Science and Research Institute of Bioscience and Biotechnology, Hallym University, Chuncheon, 24252 Korea
| | - Soo Young Choi
- Department of Biomedical Science and Research Institute of Bioscience and Biotechnology, Hallym University, Chuncheon, 24252 Korea
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8
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Chokeberry Anthocyanin Extract as Pancreatic β-Cell Protectors in Two Models of Induced Oxidative Stress. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2015; 2015:429075. [PMID: 26113953 PMCID: PMC4465716 DOI: 10.1155/2015/429075] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/30/2014] [Revised: 04/29/2015] [Accepted: 05/03/2015] [Indexed: 01/30/2023]
Abstract
The aim of this study was to investigate the protective effects of a chokeberry anthocyanin extract (CAE) on pancreatic β-cells (βTC3) exposed to hydrogen peroxide- (H2O2-) and high glucose- (HG-) induced oxidative stress conditions. In order to quantify individual anthocyanins high performance liquid chromatography (HPLC) coupled to photodiode array (PDA) was used. The identification of the fragment ion pattern of anthocyanins was carried out by electrospray ionization mass spectrometry (LC-ESI-MS). The results showed that physiologically achievable concentrations of CAE (1, 5, and 10 μM) protect βTC3 against H2O2- and HG-induced cytotoxicity. Antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) were increased in pancreatic β-cells pretreated with CAE compared to cells exposed to the prooxidant agents. GSH levels initially reduced after exposure to H2O2 and HG were restored by pretreatment with CAE. Insulin secretion in βTC3 cells was enhanced by CAE pretreatment. CAE restored the insulin pool and diminished the intracellular reactive oxygen species level in glucose-induced stress condition in βTC3 cells. These results demonstrate that anthocyanins from CAE were biologically active, showing a secretagogue potential and an antioxidative protection of enzymatic systems, conferring protection against H2O2 and glucose toxicity in βTC3 cells.
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9
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Pacifici F, Arriga R, Sorice GP, Capuani B, Scioli MG, Pastore D, Donadel G, Bellia A, Caratelli S, Coppola A, Ferrelli F, Federici M, Sconocchia G, Tesauro M, Sbraccia P, Della-Morte D, Giaccari A, Orlandi A, Lauro D. Peroxiredoxin 6, a novel player in the pathogenesis of diabetes. Diabetes 2014; 63:3210-3220. [PMID: 24947358 DOI: 10.2337/db14-0144] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Enhanced oxidative stress contributes to the pathogenesis of diabetes and its complications. Peroxiredoxin 6 (PRDX6) is a key regulator of cellular redox balance, with the peculiar ability to neutralize peroxides, peroxynitrite, and phospholipid hydroperoxides. In the current study, we aimed to define the role of PRDX6 in the pathophysiology of type 2 diabetes (T2D) using PRDX6 knockout (-/-) mice. Glucose and insulin responses were evaluated respectively by intraperitoneal glucose and insulin tolerance tests. Peripheral insulin sensitivity was analyzed by euglycemic-hyperinsulinemic clamp, and molecular tools were used to investigate insulin signaling. Moreover, inflammatory and lipid parameters were evaluated. We demonstrated that PRDX6(-/-) mice developed a phenotype similar to early-stage T2D caused by both reduced glucose-dependent insulin secretion and increased insulin resistance. Impaired insulin signaling was present in PRDX6(-/-) mice, leading to reduction of muscle glucose uptake. Morphological and ultrastructural changes were observed in islets of Langerhans and livers of mutant animals, as well as altered plasma lipid profiles and inflammatory parameters. In conclusion, we demonstrated that PRDX6 is a key mediator of overt hyperglycemia in T2D glucose metabolism, opening new perspectives for targeted therapeutic strategies in diabetes care.
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Affiliation(s)
- Francesca Pacifici
- Department of System Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Roberto Arriga
- Department of System Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Gian Pio Sorice
- Division of Endocrinology and Metabolic Diseases, Università Cattolica del Sacro Cuore, Rome, Italy Diabetic Care Clinics, Associazione dei Cavalieri Italiani Sovrano Militare Ordine di Malta, Rome, Italy
| | - Barbara Capuani
- Department of System Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Maria Giovanna Scioli
- Anatomic Pathology, Department of Biomedicine and Prevention, University of Rome Tor Vergata, Rome, Italy
| | - Donatella Pastore
- Department of System Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Giulia Donadel
- Department of System Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Alfonso Bellia
- Department of System Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Sara Caratelli
- Department of System Medicine, University of Rome Tor Vergata, Rome, Italy Institute of Translational Pharmacology, National Research Council, Rome, Italy
| | - Andrea Coppola
- Department of System Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Francesca Ferrelli
- Department of System Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Massimo Federici
- Department of System Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Giuseppe Sconocchia
- Department of System Medicine, University of Rome Tor Vergata, Rome, Italy Institute of Translational Pharmacology, National Research Council, Rome, Italy
| | - Manfredi Tesauro
- Department of System Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Paolo Sbraccia
- Department of System Medicine, University of Rome Tor Vergata, Rome, Italy
| | - David Della-Morte
- Department of System Medicine, University of Rome Tor Vergata, Rome, Italy Istituto di Ricovero e Cura a Carattere Scientifico San Raffaele Pisana, Rome, Italy
| | - Andrea Giaccari
- Division of Endocrinology and Metabolic Diseases, Università Cattolica del Sacro Cuore, Rome, Italy Fondazione Don Carlo Gnocchi, Milan, Italy
| | - Augusto Orlandi
- Anatomic Pathology, Department of Biomedicine and Prevention, University of Rome Tor Vergata, Rome, Italy
| | - Davide Lauro
- Department of System Medicine, University of Rome Tor Vergata, Rome, Italy
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10
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Yadav R, Samuni Y, Abramson A, Zeltser R, Casap N, Kabiraj TK, L Banach M, Samuni U. Pro-oxidative synergic bactericidal effect of NO: kinetics and inhibition by nitroxides. Free Radic Biol Med 2014; 67:248-54. [PMID: 24140438 DOI: 10.1016/j.freeradbiomed.2013.10.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2013] [Revised: 09/20/2013] [Accepted: 10/08/2013] [Indexed: 11/20/2022]
Abstract
NO plays diverse roles in physiological and pathological processes, occasionally resulting in opposing effects, particularly in cells subjected to oxidative stress. NO mostly protects eukaryotes against oxidative injury, but was demonstrated to kill prokaryotes synergistically with H2O2. This could be a promising therapeutic avenue. However, recent conflicting findings were reported describing dramatic protective activity of NO. The previous studies of NO effects on prokaryotes applied a transient oxidative stress while arbitrarily checking the residual bacterial viability after 30 or 60min and ignoring the process kinetics. If NO-induced synergy and the oxidative stress are time-dependent, the elucidation of the cell killing kinetics is essential, particularly for survival curves exhibiting a "shoulder" sometimes reflecting sublethal damage as in the linear-quadratic survival models. We studied the kinetics of NO synergic effects on H2O2-induced killing of microbial pathogens. A synergic pro-oxidative activity toward gram-negative and gram-positive cells is demonstrated even at sub-μM/min flux of NO. For certain strains, the synergic effect progressively increased with the duration of cell exposure, and the linear-quadratic survival model best fit the observed survival data. In contrast to the failure of SOD to affect the bactericidal process, nitroxide SOD mimics abrogated the pro-oxidative synergy of NO/H2O2. These cell-permeative antioxidants, which hardly react with diamagnetic species and react neither with NO nor with H2O2, can detoxify redox-active transition metals and catalytically remove intracellular superoxide and nitrogen-derived reactive species such as (•)NO2 or peroxynitrite. The possible mechanism underlying the bactericidal NO synergy under oxidative stress and the potential therapeutic gain are discussed.
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Affiliation(s)
- Reeta Yadav
- Department of Chemistry and Biochemistry, Queens College, City University of New York, Flushing, NY 11367, USA
| | - Yuval Samuni
- Department of Oral and Maxillofacial Surgery, Barzilai Medical Center, Ashkelon, Israel; School of Medicine, Barwon Health, Deakin University, Geelong, VIC 3220, Australia
| | - Alex Abramson
- Department of Oral and Maxillofacial Surgery, Barzilai Medical Center, Ashkelon, Israel
| | - Rephael Zeltser
- Department of Oral and Maxillofacial Surgery, Hebrew University-Hadassah Medical Center, Jerusalem 91120, Israel
| | - Nardi Casap
- Department of Oral and Maxillofacial Surgery, Hebrew University-Hadassah Medical Center, Jerusalem 91120, Israel
| | - Tonmoy K Kabiraj
- Department of Chemistry and Biochemistry, Queens College, City University of New York, Flushing, NY 11367, USA
| | - Maureen L Banach
- Department of Chemistry and Biochemistry, Queens College, City University of New York, Flushing, NY 11367, USA
| | - Uri Samuni
- Department of Chemistry and Biochemistry, Queens College, City University of New York, Flushing, NY 11367, USA.
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11
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Azzi J, Geara AS, El-Sayegh S, Abdi R. Immunological aspects of pancreatic islet cell transplantation. Expert Rev Clin Immunol 2014; 6:111-24. [DOI: 10.1586/eci.09.67] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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12
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Steinbrenner H. Interference of selenium and selenoproteins with the insulin-regulated carbohydrate and lipid metabolism. Free Radic Biol Med 2013; 65:1538-1547. [PMID: 23872396 DOI: 10.1016/j.freeradbiomed.2013.07.016] [Citation(s) in RCA: 112] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2013] [Revised: 07/08/2013] [Accepted: 07/09/2013] [Indexed: 01/26/2023]
Abstract
An assumed link between supranutritional intake of the micronutrient selenium (Se) and type 2 diabetes mellitus is discussed controversially. Se concentrations in the habitual diet and in dietary supplements are probably not sufficient to induce overt diabetes in healthy individuals. On the other hand, high plasma Se and selenoprotein P (Sepp1) levels have been found to be associated with biomarkers of an impaired carbohydrate and lipid homeostasis in humans. Moreover, abundant expression of antioxidant selenoproteins due to dietary Se oversupply resulted in hyperinsulinemia and decreased insulin sensitivity in animal models. This review discusses findings from animal and cell culture studies in search of molecular mechanisms underlying an interference of Se and selenproteins such as the Se transport and supply protein Sepp1 and the hydrogen peroxide-reducing selenoenzyme glutathione peroxidase 1 (GPx1) with insulin-controlled metabolic pathways. A probable rationale derives from the positive and negative regulation of both glucose-induced insulin secretion and insulin-induced signaling by hydrogen peroxide. Se status and GPx1 expression have been reported to affect the activity of insulin-antagonistic phosphatases that are regulated by hydrogen peroxide-mediated reversible oxidation of catalytic cysteine residues. GPx1 and/or Sepp1 inhibited phosphorylation (activation) of key mediators in energy metabolism such as protein kinase B (Akt) and AMP-activated protein kinase (AMPK) in liver and/or skeletal muscle. Conversely, a dys-regulated carbohydrate metabolism in diabetes might affect plasma Se and Sepp1 levels, as the hepatic biosynthesis of Sepp1 is suppressed by insulin and stimulated under hyperglycemic conditions.
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Affiliation(s)
- Holger Steinbrenner
- Institute for Biochemistry and Molecular Biology I, Heinrich-Heine-Universität, Düsseldorf, Germany.
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13
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Yoo YM. Melatonin-mediated insulin synthesis during endoplasmic reticulum stress involves HuD expression in rat insulinoma INS-1E cells. J Pineal Res 2013; 55:207-20. [PMID: 23711134 DOI: 10.1111/jpi.12064] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2013] [Accepted: 04/26/2013] [Indexed: 01/12/2023]
Abstract
In this study, we investigated how melatonin mediates insulin synthesis through endoplasmic reticulum (ER) via HuD expression in rat insulinoma INS-1E cells. Under ER stress condition (thapsigargin with/without melatonin, tunicamycin with/without melatonin), phosphorylation of AMP-activated protein kinase (p-AMPK) was significantly increased when compared with only with/without melatonin (control/melatonin). Insulin receptor substrate (IRS) two protein was significantly reduced under conditions of ER stress when compared with control/melatonin, but no expression of IRS1 protein was observed. In thapsigargin treatment, melatonin (10, 50 μm) increased IRS2 protein expression in a dose-dependent manner. p-Akt (Ser473) expression significantly decreased under ER stress condition prior to control/melatonin. Melatonin (10, 50 μm) significantly reduced nuclear and cellular p85α expressions in a dose-dependent manner when compared with only thapsigargin or tunicamycin. These results indicate the activation of the aforementioned expressions under regulation of the pathway, AMPK → IRS2 → Akt/PKB → PI3K (p85α). However, mammalian target of rapamycin and raptor protein, mTORC1, was found to be independent of the ER stress response. In thapsigargin treatment, melatonin increased nuclear mammalian RNA-binding protein (HuD) expression and reduced cellular HuD expression and subsequently resulted in a decrease in cellular insulin level and rise in insulin secretion in a dose-dependent manner. In tunicamycin treatment, HuD and insulin proteins showed similar expression tendencies. These results indicate that ER stress/melatonin, especially thapsigargin/melatonin, increased nuclear HuD expression and subsequently resulted in a decrease in intracellular biosynthesis; it is hypothesized that extracellular secretion of insulin may be regulated by melatonin.
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Affiliation(s)
- Yeong-Min Yoo
- Department of Biomedical Engineering, College of Health Science, Yonsei University, Wonju, Gangwon-do 220-710, Korea.
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14
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Abstract
The importance of K(ATP) channels in stimulus-secretion coupling of β-cells is well established, although they are not indispensable for the maintenance of glycaemic control. This review article depicts a new role for K(ATP) channels by showing that genetic or pharmacological ablation of these channels protects β-cells against oxidative stress. Increased production of oxidants is a crucial factor in the pathogenesis of type 2 diabetes mellitus (T2DM). T2DM develops when β-cells can no longer compensate for the high demand of insulin resulting from excess fuel intake. Instead β-cells start to secrete less insulin and β-cell mass is diminished by apoptosis. Both, reduction of insulin secretion and β-cell mass induced by oxidative stress, are prevented by deletion or inhibition of K(ATP) channels. These findings may open up new insights into the early treatment of T2DM.
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Affiliation(s)
- G Drews
- Department of Pharmacology, Institute of Pharmacy, University of Tübingen, Tübingen, Germany.
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15
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Abstract
Mimitin, a novel mitochondrial protein, has been shown to act as a molecular chaperone for the mitochondrial complex I and to regulate ATP synthesis. During Type 1 diabetes development, pro-inflammatory cytokines induce mitochondrial damage in pancreatic β-cells, inhibit ATP synthesis and reduce glucose-induced insulin secretion. Mimitin was expressed in rat pancreatic islets including β-cells and decreased by cytokines. In the ob/ob mouse, a model of insulin resistance and obesity, mimitin expression was down-regulated in liver and brain, up-regulated in heart and kidney, but not affected in islets. To further analyse the impact of mimitin on β-cell function, two β-cell lines, one with a low (INS1E) and another with a higher (MIN6) mimitin expression were studied. Mimitin overexpression protected INS1E cells against cytokine-induced caspase 3 activation, mitochondrial membrane potential reduction and ATP production inhibition, independently from the NF-κB (nuclear factor κB)-iNOS (inducible NO synthase) pathway. Mimitin overexpression increased basal and glucose-induced insulin secretion and prevented cytokine-mediated suppression of insulin secretion. Mimitin knockdown in MIN6 cells had opposite effects to those observed after overexpression. Thus mimitin has the capacity to modulate pancreatic islet function and to reduce cytokine toxicity.
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16
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Laschak M, Spindler KD, Schrader AJ, Hessenauer A, Streicher W, Schrader M, Cronauer MV. JS-K, a glutathione/glutathione S-transferase-activated nitric oxide releasing prodrug inhibits androgen receptor and WNT-signaling in prostate cancer cells. BMC Cancer 2012; 12:130. [PMID: 22462810 PMCID: PMC3376035 DOI: 10.1186/1471-2407-12-130] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2011] [Accepted: 03/30/2012] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Nitric oxide (NO) and its oxidative reaction products have been repeatedly shown to block steroid receptor function via nitrosation of zinc finger structures in the DNA-binding domain (DBD). In consequence NO-donors could be of special interest for the treatment of deregulated androgen receptor(AR)-signaling in castration resistant prostate cancer (CRPC). METHODS Prostate cancer (PCa) cells were treated with JS-K, a diazeniumdiolate derivate capable of generating large amounts of intracellular NO following activation by glutathione S-transferase. Generation of NO was determined indirectly by the detection of nitrate in tissue culture medium or by immunodetection of nitrotyrosine in the cytoplasm. Effects of JS-K on intracellular AR-levels were determined by western blotting. AR-dimerization was analyzed by mammalian two hybrid assay, nuclear translocation of the AR was visualized in PCa cells transfected with a green fluorescent AR-Eos fusion protein using fluorescence microscopy. Modulation of AR- and WNT-signalling by JS-K was investigated using reporter gene assays. Tumor cell proliferation following JS-K treatment was measured by MTT-Assay. RESULTS The NO-releasing compound JS-K was shown to inhibit AR-mediated reporter gene activity in 22Rv1 CRPC cells. Inhibition of AR signaling was neither due to an inhibition of nuclear import nor to a reduction in AR-dimerization. In contrast to previously tested NO-donors, JS-K was able to reduce the intracellular concentration of functional AR. This could be attributed to the generation of extremely high intracellular levels of the free radical NO as demonstrated indirectly by high levels of nitrotyrosine in JS-K treated cells. Moreover, JS-K diminished WNT-signaling in AR-positive 22Rv1 cells. In line with these observations, castration resistant 22Rv1 cells were found to be more susceptible to the growth inhibitory effects of JS-K than the androgen dependent LNCaP which do not exhibit an active WNT-signaling pathway. CONCLUSIONS Our results suggest that small molecules able to inhibit WNT- and AR-signaling via NO-release represent a promising platform for the development of new compounds for the treatment of CRPC.
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Affiliation(s)
- Martin Laschak
- Department of Urology, Ulm University, Prittwitzstrasse 43, 89075, Ulm, Germany
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Honey supplementation in spontaneously hypertensive rats elicits antihypertensive effect via amelioration of renal oxidative stress. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2012; 2012:374037. [PMID: 22315654 PMCID: PMC3270456 DOI: 10.1155/2012/374037] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/01/2011] [Revised: 09/05/2011] [Accepted: 09/25/2011] [Indexed: 02/07/2023]
Abstract
Oxidative stress is implicated in the pathogenesis and/or maintenance of elevated blood pressure in hypertension. This study investigated the effect of honey on elevated systolic blood pressure (SBP) in spontaneously hypertensive rats (SHR). It also evaluated the effect of honey on the amelioration of oxidative stress in the kidney of SHR as a possible mechanism of its antihypertensive effect. SHR and Wistar Kyoto (WKY) rats were randomly divided into 2 groups and administered distilled water or honey by oral gavage once daily for 12 weeks. The control SHR had significantly higher SBP and renal malondialdehyde (MDA) levels than did control WKY. The mRNA expression levels of nuclear factor erythroid 2-related factor 2 (Nrf2) and glutathione S-transferase (GST) were significantly downregulated while total antioxidant status (TAS) and activities of GST and catalase (CAT) were higher in the kidney of control SHR. Honey supplementation significantly reduced SBP and MDA levels in SHR. Honey significantly reduced the activities of GST and CAT while it moderately but insignificantly upregulated the Nrf2 mRNA expression level in the kidney of SHR. These results indicate that Nrf2 expression is impaired in the kidney of SHR. Honey supplementation considerably reduces elevated SBP via amelioration of oxidative stress in the kidney of SHR.
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Lee EM, Lee YE, Lee E, Ryu GR, Ko SH, Moon SD, Song KH, Ahn YB. Protective Effect of Heme Oxygenase-1 on High Glucose-Induced Pancreatic β-Cell Injury. Diabetes Metab J 2011; 35:469-79. [PMID: 22111038 PMCID: PMC3221022 DOI: 10.4093/dmj.2011.35.5.469] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2011] [Accepted: 10/19/2011] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND Glucose toxicity that is caused by chronic exposure to a high glucose concentration leads to islet dysfunction and induces apoptosis in pancreatic β-cells. Heme oxygenase-1 (HO-1) has been identified as an anti-apoptotic and cytoprotective gene. The purpose of this study is to investigate whether HO-1 up-regulation when using metalloprotophyrin (cobalt protoporphyrin, CoPP) could protect pancreatic β-cells from high glucose-induced apoptosis. METHODS Reverse transcription-polymerase chain reaction was performed to analyze the CoPP-induced mRNA expression of HO-1. Cell viability of INS-1 cells cultured in the presence of CoPP was examined by acridine orange/propidium iodide staining. The generation of intracellular reactive oxygen species (ROS) was measured using flow cytometry. Glucose stimulated insulin secretion (GSIS) was determined following incubation with CoPP in different glucose concentrations. RESULTS CoPP increased HO-1 mRNA expression in both a dose- and time-dependent manner. Overexpression of HO-1 inhibited caspase-3, and the number of dead cells in the presence of CoPP was significantly decreased when exposed to high glucose conditions (HG). CoPP also decreased the generation of intracellular ROS by 50% during 72 hours of culture with HG. However, decreased GSIS was not recovered even in the presence of CoPP. CONCLUSION Our data suggest that CoPP-induced HO-1 up-regulation results in protection from high glucose-induced apoptosis in INS-1 cells; however, glucose stimulated insulin secretion is not restored.
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Affiliation(s)
- Eun-Mi Lee
- Division of Endocrinology and Metabolism, Department of Internal Medicine, The Catholic University of Korea College of Medicine, Seoul, Korea
| | - Young-Eun Lee
- Division of Endocrinology and Metabolism, Department of Internal Medicine, The Catholic University of Korea College of Medicine, Seoul, Korea
| | - Esder Lee
- Division of Endocrinology and Metabolism, Department of Internal Medicine, The Catholic University of Korea College of Medicine, Seoul, Korea
| | - Gyeong Ryul Ryu
- Division of Endocrinology and Metabolism, Department of Internal Medicine, The Catholic University of Korea College of Medicine, Seoul, Korea
| | - Seung-Hyun Ko
- Division of Endocrinology and Metabolism, Department of Internal Medicine, The Catholic University of Korea College of Medicine, Seoul, Korea
| | - Sung-Dae Moon
- Division of Endocrinology and Metabolism, Department of Internal Medicine, The Catholic University of Korea College of Medicine, Seoul, Korea
| | - Ki-Ho Song
- Division of Endocrinology and Metabolism, Department of Internal Medicine, The Catholic University of Korea College of Medicine, Seoul, Korea
| | - Yu-Bae Ahn
- Division of Endocrinology and Metabolism, Department of Internal Medicine, The Catholic University of Korea College of Medicine, Seoul, Korea
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Vaithilingam V, Tuch BE. Islet transplantation and encapsulation: an update on recent developments. Rev Diabet Stud 2011; 8:51-67. [PMID: 21720673 DOI: 10.1900/rds.2011.8.51] [Citation(s) in RCA: 114] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Human islet transplantation can provide good glycemic control in diabetic recipients without exogenous insulin. However, a major factor limiting its application is the recipient's need to adhere to life-long immunosuppression, something that has serious side effects. Microencapsulating human islets is a strategy that should prevent rejection of the grafted tissue without the need for anti-rejection drugs. Despite promising studies in various animal models, the encapsulated human islets so far have not made an impact in the clinical setting. Many non-immunological and immunological factors such as biocompatibility, reduced immunoprotection, hypoxia, pericapsular fibrotic overgrowth, effects of the encapsulation process and post-transplant inflammation hamper the successful application of this promising technology. In this review, strategies are discussed to overcome the above-mentioned factors and to enhance the survival and function of encapsulated insulin-producing cells, whether in islets or surrogate β-cells. Studies at our center show that barium alginate microcapsules are biocompatible in rodents, but not in humans, raising concerns over the use of rodents to predict outcomes. Studies at our center also show that the encapsulation process had little or no effect on the cellular transcriptome of human islets and on their ability to function either in vitro or in vivo. New approaches incorporating further modifications to the microcapsule surface to prevent fibrotic overgrowth are vital, if encapsulated human islets or β-cell surrogates are to become a viable therapy option for type 1 diabetes in humans.
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Differential effects of proinflammatory cytokines on cell death and ER stress in insulin-secreting INS1E cells and the involvement of nitric oxide. Cytokine 2011; 55:195-201. [PMID: 21531147 DOI: 10.1016/j.cyto.2011.04.002] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2010] [Revised: 03/18/2011] [Accepted: 04/05/2011] [Indexed: 12/22/2022]
Abstract
Proinflammatory cytokines produced by immune cells destroy pancreatic beta cells in type 1 diabetes. The aim of this study was to investigate the cytokine network and its effects in insulin-secreting cells. INS1E cells were exposed to different combinations of proinflammatory cytokines. Cytokine toxicity was estimated by MTT assay and caspase activation measurements. The NFκB-iNOS pathway was analyzed by a SEAP reporter gene assay, Western-blotting and nitrite measurements. Gene expression analyses of ER stress markers, Chop and Bip, were performed by real-time RT-PCR. Cytokines tested in this study, namely IL-1β, TNFα and IFNγ, had deleterious effects on beta cell viability. The most potent toxicity exhibited IL-1β and its combinations with other cytokines. The toxic effects of IL-1β towards cell viability, caspase activation and iNOS activity were dependent on nitric oxide and abolished by an iNOS blocker. IL-1β was the strongest inducer of the NFκB activation. An iNOS blocker inhibited IL-1β-mediated NFκB activation in the first, initial phase of cytokine action, but did not affect significantly NFκB activation after prolonged incubation. Interestingly iNOS protein expression was induced predominantly by IL-1β and decreased in the presence of an iNOS blocker in the case of a short time exposure. The changes in the expression of ER stress markers were also almost exclusively dependent on the IL-1β presence and counteracted by iNOS blockade. Thus cytokine-induced beta cell death is primarily IL-1β mediated with a NO-independent enhancement by TNFα and IFNγ. The deleterious effects on cell viability and function are crucially dependent on IL-1β-induced nitric oxide formation.
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Frey AD, Schmid VH, Kallio PT. Genetic engineering of the pancreatic β-cell line MIN6 to express bacterial globin proteins protects cells from nitrosative stress. Biotechnol Appl Biochem 2011. [DOI: 10.1002/bab.4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Cytokine toxicity in insulin-producing cells is mediated by nitro-oxidative stress-induced hydroxyl radical formation in mitochondria. J Mol Med (Berl) 2011; 89:785-98. [PMID: 21487676 DOI: 10.1007/s00109-011-0747-1] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2010] [Revised: 02/22/2011] [Accepted: 03/07/2011] [Indexed: 01/27/2023]
Abstract
Although nitric oxide (NO) and oxidative stress both contribute to proinflammatory cytokine toxicity in pancreatic β-cells during type 1 diabetes mellitus (T1DM) development, the interactions between NO and reactive oxygen species (ROS) in cytokine-mediated β-cell death have not been clarified. Exposure of insulin-producing RINm5F cells to IL-1β generated NO, while exposure to a combination of IL-1β, TNF-α, and IFN-γ, which simulates T1DM conditions, generated both NO and ROS. In theory, two reactions between NO and ROS are possible, one with the superoxide radical yielding peroxynitrite, and the other with hydrogen peroxide (H(2)O(2)) yielding hydroxyl radicals. Results of the present work exclude peroxynitrite involvement in cytokine toxicity to β-cells because its generation did not correlate with the toxic action of cytokines. On the other hand, we show that H(2)O(2), produced upon exposure of insulin-producing cell clones and primary rat islet cells to cytokines almost exclusively in the mitochondria, reacted in the presence of trace metal (Fe(++)) with NO forming highly toxic hydroxyl radicals, thus explaining the severe toxicity that causes apoptotic β-cell death. Expression of the H(2)O(2)-inactivating enzyme catalase in mitochondria protected against cytokine toxicity by preventing hydroxyl radical formation. We therefore conclude that proinflammatory cytokine-mediated β-cell death is due to nitro-oxidative stress-mediated hydroxyl radical formation in the mitochondria.
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23
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Erejuwa OO, Sulaiman SA, Wahab MSA, Sirajudeen KNS, Salleh MSM, Gurtu S. Differential responses to blood pressure and oxidative stress in streptozotocin-induced diabetic Wistar-Kyoto rats and spontaneously hypertensive rats: effects of antioxidant (honey) treatment. Int J Mol Sci 2011; 12:1888-907. [PMID: 21673929 PMCID: PMC3111640 DOI: 10.3390/ijms12031888] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2010] [Revised: 12/29/2010] [Accepted: 01/05/2011] [Indexed: 01/10/2023] Open
Abstract
Oxidative stress is implicated in the pathogenesis and/or complications of hypertension and/or diabetes mellitus. A combination of these disorders increases the risk of developing cardiovascular events. This study investigated the effects of streptozotocin (60 mg/kg; ip)-induced diabetes on blood pressure, oxidative stress and effects of honey on these parameters in the kidneys of streptozotocin-induced diabetic Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHR). Diabetic WKY and SHR were randomized into four groups and received distilled water (0.5 mL) and honey (1.0 g/kg) orally once daily for three weeks. Control SHR had reduced malondialdehyde (MDA) and increased systolic blood pressure (SBP), catalase (CAT) activity, and total antioxidant status (TAS). SBP, activities of glutathione peroxidase (GPx) and glutathione reductase (GR) were elevated while TAS was reduced in diabetic WKY. In contrast, SBP, TAS, activities of GPx and GR were reduced in diabetic SHR. Antioxidant (honey) treatment further reduced SBP in diabetic SHR but not in diabetic WKY. It also increased TAS, GSH, reduced glutathione (GSH)/oxidized glutathione (GSSG) ratio, activities of GPx and GR in diabetic SHR. These data suggest that differences in types, severity, and complications of diseases as well as strains may influence responses to blood pressure and oxidative stress.
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Affiliation(s)
- Omotayo O. Erejuwa
- Department of Pharmacology, School of Medical Sciences, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan, Malaysia; E-Mails: (S.A.S.); (M.S.A.W.)
| | - Siti A. Sulaiman
- Department of Pharmacology, School of Medical Sciences, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan, Malaysia; E-Mails: (S.A.S.); (M.S.A.W.)
| | - Mohd Suhaimi Ab Wahab
- Department of Pharmacology, School of Medical Sciences, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan, Malaysia; E-Mails: (S.A.S.); (M.S.A.W.)
| | - Kuttulebbai N. S. Sirajudeen
- Department of Chemical Pathology, School of Medical Sciences, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan, Malaysia; E-Mail:
| | - Md Salzihan Md Salleh
- Department of Pathology, School of Medical Sciences, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan, Malaysia; E-Mail:
| | - Sunil Gurtu
- Monash University Sunway Campus, Jeffrey Cheah School of Medicine and Health Sciences, Jalan Lagoon Selatan, 46150, Bandar Sunway, Selangor, Malaysia; E-Mail:
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Comparison of antioxidant effects of honey, glibenclamide, metformin, and their combinations in the kidneys of streptozotocin-induced diabetic rats. Int J Mol Sci 2011; 12:829-43. [PMID: 21340016 PMCID: PMC3039982 DOI: 10.3390/ijms12010829] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2010] [Revised: 12/07/2010] [Accepted: 12/21/2010] [Indexed: 11/30/2022] Open
Abstract
Hyperglycemia-induced increase in oxidative stress is implicated in diabetic complications. This study investigated the effect of metformin and/or glibenclamide in combination with honey on antioxidant enzymes and oxidative stress markers in the kidneys of streptozotocin (60 mg/kg; intraperitoneal)-induced diabetic rats. Diabetic rats were randomized into eight groups of five to seven rats and received distilled water (0.5 mL); honey (1.0 g/kg); metformin (100 mg/kg); metformin (100 mg/kg) and honey (1.0 g/kg); glibenclamide (0.6 mg/kg); glibenclamide (0.6 mg/kg) and honey (1.0 g/kg); metformin (100 mg/kg) and glibenclamide (0.6 mg/kg); or metformin (100 mg/kg), glibenclamide (0.6 mg/kg) and honey (1.0 g/kg) orally once daily for four weeks. Malondialdehyde (MDA) levels, glutathione peroxidase (GPx) and superoxide dismutase (SOD) activities were significantly elevated while catalase (CAT) activity, total antioxidant status (TAS), reduced glutathione (GSH), and GSH:oxidized glutathione (GSSG) ratio was significantly reduced in the diabetic kidneys. CAT, glutathione reductase (GR), TAS, and GSH remained significantly reduced in the diabetic rats treated with metformin and/or glibenclamide. In contrast, metformin or glibenclamide combined with honey significantly increased CAT, GR, TAS, and GSH. These results suggest that combination of honey with metformin or glibenclamide might offer additional antioxidant effect to these drugs. This might reduce oxidative stress-mediated damage in diabetic kidneys.
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Bae UJ, Lee DY, Song MY, Lee SM, Park JW, Ryu JH, Park BH. A Prenylated Flavan from Broussonetia kazinoki Prevents Cytokine-Induced .BETA.-Cell Death through Suppression of Nuclear Factor-.KAPPA.B Activity. Biol Pharm Bull 2011; 34:1026-31. [DOI: 10.1248/bpb.34.1026] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Ui-Jin Bae
- Department of Biochemistry, Research Institute for Endocrine Sciences, and Diabetes Research Center, Chonbuk National University Medical School
| | - Da Yeon Lee
- College of Pharmacy, Sookmyung Women's University
| | - Mi-Young Song
- Department of Biochemistry, Research Institute for Endocrine Sciences, and Diabetes Research Center, Chonbuk National University Medical School
| | - Sang-Myeong Lee
- Division of Biotechnology, College of Environmental and Bioresource Sciences, Chonbuk National University
| | - Jin-Woo Park
- Department of Biochemistry, Research Institute for Endocrine Sciences, and Diabetes Research Center, Chonbuk National University Medical School
| | - Jae-Ha Ryu
- College of Pharmacy, Sookmyung Women's University
| | - Byung-Hyun Park
- Department of Biochemistry, Research Institute for Endocrine Sciences, and Diabetes Research Center, Chonbuk National University Medical School
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Bloch K, Bloch O, Tarasenko I, Lazard D, Rapoport M, Vardi P. A strategy for the engineering of insulin producing cells with a broad spectrum of defense properties. Biomaterials 2010; 32:1816-25. [PMID: 21144579 DOI: 10.1016/j.biomaterials.2010.11.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2010] [Accepted: 11/01/2010] [Indexed: 11/26/2022]
Abstract
Insulin-producing pancreatic beta cells are known to be extremely susceptible to the oxidative stress and hypoxia generated following islet transplantation in diabetic patients. We hereby present a novel in vivo selection strategy based on the isolation of insulin-producing cells with enhanced protection after repeated rounds of encapsulation and xenotransplantation. Rat insulinoma INS-1 cells were encapsulated in alginate macrobeads and transplanted in the peritoneal cavity of mice. After 2 days the beads were retrieved and cells were recovered from alginate and propagated in vitro until submitted to a second round of encapsulation and transplantation. Three days later, the surviving cells, named INS-1m2, were isolated from the alginate beads and their protection and functional activity examined. Compared to parental INS-1 cells, the selected INS-1m2 cells were more resistant to hydrogen peroxide, nitric oxide, alloxan and hypoxia. This enhanced protection of the selected cells correlated with the increased level of catalase and poly (ADP-ribose) polymerase expression. Although selected cells expressed more insulin than parental cells, no change in their insulin response to glucose was observed. We conclude that the in vivo selection strategy is a powerful tool for the engineering of insulin producing cells with a broad spectrum of defense properties.
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Affiliation(s)
- Konstantin Bloch
- Diabetes and Obesity Research Laboratory, Felsenstein Medical Research Center, Sackler Faculty of Medicine, Tel-Aviv University, Beilinson Campus, Petah Tikva 49100, Israel.
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Xiang FL, Lu X, Strutt B, Hill DJ, Feng Q. NOX2 deficiency protects against streptozotocin-induced beta-cell destruction and development of diabetes in mice. Diabetes 2010; 59:2603-11. [PMID: 20627937 PMCID: PMC3279537 DOI: 10.2337/db09-1562] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
OBJECTIVE The role of NOX2-containing NADPH oxidase in the development of diabetes is not fully understood. We hypothesized that NOX2 deficiency decreases reactive oxygen species (ROS) production and immune response and protects against streptozotocin (STZ)-induced β-cell destruction and development of diabetes in mice. RESEARCH DESIGN AND METHODS Five groups of mice--wild-type (WT), NOX2(-/-), WT treated with apocynin, and WT adoptively transferred with NOX2(-/-) or WT splenocytes--were treated with multiple-low-dose STZ. Blood glucose and insulin levels were monitored, and an intraperitoneal glucose tolerance test was performed. Isolated WT and NOX2(-/-) pancreatic islets were treated with cytokines for 48 h. RESULTS Significantly lower blood glucose levels, higher insulin levels, and better glucose tolerance was observed in NOX2(-/-) mice and in WT mice adoptively transferred with NOX2(-/-) splenocytes compared with the respective control groups after STZ treatment. Compared with WT, β-cell apoptosis, as determined by TUNEL staining, and insulitis were significantly decreased, whereas β-cell mass was significantly increased in NOX2(-/-) mice. In response to cytokine stimulation, ROS production was significantly decreased, and insulin secretion was preserved in NOX2(-/-) compared with WT islets. Furthermore, proinflammatory cytokine release induced by concanavalin A was significantly decreased in NOX2(-/-) compared with WT splenocytes. CONCLUSIONS NOX2 deficiency decreases β-cell destruction and preserves islet function in STZ-induced diabetes by reducing ROS production, immune response, and β-cell apoptosis.
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Affiliation(s)
- Fu-Li Xiang
- From the Departments of Medicine, Physiology, and Pharmacology, University of Western Ontario, Lawson Health Research Institute, London, Ontario, Canada
| | - Xiangru Lu
- From the Departments of Medicine, Physiology, and Pharmacology, University of Western Ontario, Lawson Health Research Institute, London, Ontario, Canada
| | - Brenda Strutt
- From the Departments of Medicine, Physiology, and Pharmacology, University of Western Ontario, Lawson Health Research Institute, London, Ontario, Canada
| | - David J. Hill
- From the Departments of Medicine, Physiology, and Pharmacology, University of Western Ontario, Lawson Health Research Institute, London, Ontario, Canada
| | - Qingping Feng
- From the Departments of Medicine, Physiology, and Pharmacology, University of Western Ontario, Lawson Health Research Institute, London, Ontario, Canada
- Corresponding author: Qingping Feng,
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Tse HM, Thayer TC, Steele C, Cuda CM, Morel L, Piganelli JD, Mathews CE. NADPH oxidase deficiency regulates Th lineage commitment and modulates autoimmunity. THE JOURNAL OF IMMUNOLOGY 2010; 185:5247-58. [PMID: 20881184 DOI: 10.4049/jimmunol.1001472] [Citation(s) in RCA: 122] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Reactive oxygen species are used by the immune system to eliminate infections; however, they may also serve as signaling intermediates to coordinate the efforts of the innate and adaptive immune systems. In this study, we show that by eliminating macrophage and T cell superoxide production through the NADPH oxidase (NOX), T cell polarization was altered. After stimulation with immobilized anti-CD3 and anti-CD28 or priming recall, T cells from NOX-deficient mice exhibited a skewed Th17 phenotype, whereas NOX-intact cells produced cytokines indicative of a Th1 response. These findings were corroborated in vivo by studying two different autoimmune diseases mediated by Th17 or Th1 pathogenic T cell responses. NOX-deficient NOD mice were Th17 prone with a concomitant susceptibility to experimental allergic encephalomyelitis and significant protection against type 1 diabetes. These data validate the role of superoxide in shaping Th responses and as a signaling intermediate to modulate Th17 and Th1 T cell responses.
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Affiliation(s)
- Hubert M Tse
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15224, USA
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29
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Antioxidant protection of Malaysian tualang honey in pancreas of normal and streptozotocin-induced diabetic rats. ANNALES D'ENDOCRINOLOGIE 2010; 71:291-6. [PMID: 20398890 DOI: 10.1016/j.ando.2010.03.003] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2009] [Revised: 02/27/2010] [Accepted: 03/08/2010] [Indexed: 11/21/2022]
Abstract
Glucotoxicity contributes to beta-cell dysfunction through oxidative stress. Our previous study demonstrated that tualang honey ameliorated renal oxidative stress and produced hypoglycemic effect in streptozotocin (STZ)-induced diabetic rats. This present study investigated the hypothesis that hypoglycemic effect of tualang honey might partly be due to protection of pancreas against oxidative stress. Diabetes was induced by a single dose of STZ (60 mg/kg; ip). Diabetic rats were randomly divided into two groups and administered distilled water (0.5 ml/d) and tualang honey (1.0 g/kg/d). Similarly, two groups of non-diabetic rats received distilled water (0.5 ml/d) and tualang honey (1.0 g/kg/d). The animals were treated orally for 28 days. At the end of the treatment period, the honey-treated diabetic rats had significantly (p<0.05) reduced blood glucose levels [8.8 (5.8)mmol/L; median (interquartile range)] compared with the diabetic control rats [17.9 (2.6)mmol/L]. The pancreas of diabetic control rats showed significantly increased levels of malondialdehyde (MDA) and up-regulation of superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities. Catalase (CAT) activity was significantly reduced while glutathione-S-transferase (GST) and glutathione reductase (GR) activities remained unchanged in the pancreas of diabetic rats. Tualang honey significantly (p<0.05) reduced elevated MDA levels. Honey treatment also restored SOD and CAT activities. These results suggest that hypoglycemic effect of tualang honey might be attributed to its antioxidative effect on the pancreas.
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30
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Lee BR, Lee YP, Kim DW, Song HY, Yoo KY, Won MH, Kang TC, Lee KJ, Kim KH, Joo JH, Ham HJ, Hur JH, Cho SW, Han KH, Lee KS, Park J, Eum WS, Choi SY. Amelioration of streptozotocin-induced diabetes by Agrocybe chaxingu polysaccharide. Mol Cells 2010; 29:349-54. [PMID: 20213314 DOI: 10.1007/s10059-010-0044-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2009] [Revised: 12/27/2009] [Accepted: 01/04/2010] [Indexed: 10/19/2022] Open
Abstract
The aim of this study was to investigate the preventive effect of Agrocybe chaxingu polysaccharide on streptozocin (STZ)-induced pancreatic beta-cells destruction. Agrocybe chaxingu polysaccharide markedly reduced nitric oxide (NO) production and iNOS expression levels in RINm5F cells in a dose-dependent manner. In addition, Agrocybe chaxingu polysaccharide significantly inhibited iNOS expression and blood glucose levels in STZ-induced diabetic mice. Moreover, immunohistochemical analysis revealed that it enhanced pancreatic beta-cells resistance to destruction by STZ. These results suggest that Agrocybe chaxingu polysaccharide may have value as a therapeutic agent against diabetes mellitus.
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Affiliation(s)
- Byung Ryong Lee
- Department of Biomedical Science and Research Institute for Bioscience and Biotechnology, Hallym University, Chunchon, 200-702, Korea
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31
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Gurgul-Convey E, Lenzen S. Protection against cytokine toxicity through endoplasmic reticulum and mitochondrial stress prevention by prostacyclin synthase overexpression in insulin-producing cells. J Biol Chem 2010; 285:11121-8. [PMID: 20159982 DOI: 10.1074/jbc.m109.054775] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Proinflammatory cytokines play a crucial role in the pathogenesis of type 1 diabetes mellitus. One of the cytokine-regulated pathways mediating inflammation in this autoimmune disease is the arachidonic acid metabolism pathway, comprising both the induction of cyclooxygenases and the production of different prostaglandins. Cytokine toxicity is mediated in many cell types, including pancreatic beta cells through this pathway. Interestingly, some cell types have been shown to be insensitive to such toxicity, and this correlated with a high expression of prostacyclin synthase (PGIS). Using insulin-producing RINm5F cells as a model for pancreatic beta cells, PGIS was overexpressed and exhibited a large protective effect against cytokine toxicity. This protective effect of PGIS against cytokine toxicity correlated with a decreased activation of the transcription factor NFkappaB and the inducible NO synthase promoter as well as a reduced inducible NO synthase protein expression and nitrite production. A reduction in the cytokine-stimulated endoplasmic reticulum and mitochondrial stress was also found in the PGIS-overexpressing cells. Moreover, cytokine-induced caspase-3 activation and reduction of glucose oxidation and cell proliferation were suppressed. Thus, PGIS overexpression apparently protects insulin-producing cells against cytokine toxicity via suppression of endoplasmic reticulum and mitochondrial stress-mediated cell death pathways.
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Affiliation(s)
- Ewa Gurgul-Convey
- Institute of Clinical Biochemistry, Hannover Medical School, 30625 Hannover, Germany.
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32
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Gier B, Krippeit-Drews P, Sheiko T, Aguilar-Bryan L, Bryan J, Düfer M, Drews G. Suppression of KATP channel activity protects murine pancreatic beta cells against oxidative stress. J Clin Invest 2009; 119:3246-56. [PMID: 19805912 DOI: 10.1172/jci38817] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2009] [Accepted: 07/29/2009] [Indexed: 12/21/2022] Open
Abstract
The enhanced oxidative stress associated with type 2 diabetes mellitus contributes to disease pathogenesis. We previously identified plasma membrane-associated ATP-sensitive K+ (KATP) channels of pancreatic beta cells as targets for oxidants. Here, we examined the effects of genetic and pharmacologic ablation of KATP channels on loss of mouse beta cell function and viability following oxidative stress. Using mice lacking the sulfonylurea receptor type 1 (Sur1) subunit of KATP channels, we found that, compared with insulin secretion by WT islets, insulin secretion by Sur1-/- islets was less susceptible to oxidative stress induced by the oxidant H2O2. This was likely, at least in part, a result of the reduced ability of H2O2 to hyperpolarize plasma membrane potential and reduce cytosolic free Ca2+ concentration ([Ca2+]c) in the Sur1-/- beta cells. Remarkably, Sur1-/- beta cells were less prone to apoptosis induced by H2O2 or an NO donor than WT beta cells, despite an enhanced basal rate of apoptosis. This protective effect was attributed to upregulation of the antioxidant enzymes SOD, glutathione peroxidase, and catalase. Upregulation of antioxidant enzymes and reduced sensitivity of Sur1-/- cells to H2O2-induced apoptosis were mimicked by treatment with the sulfonylureas tolbutamide and gliclazide. Enzyme upregulation and protection against oxidant-induced apoptosis were abrogated by agents lowering [Ca2+]c. Sur1-/- mice were less susceptible than WT mice to streptozotocin-induced beta cell destruction and subsequent hyperglycemia and death, which suggests that loss of KATP channel activity may protect against streptozotocin-induced diabetes in vivo.
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Affiliation(s)
- Belinda Gier
- Institute of Pharmacy, Department of Pharmacology, University of Tübingen, Tübingen, Germany
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33
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Sartori A, Garay-Malpartida HM, Forni MF, Schumacher RI, Dutra F, Sogayar MC, Bechara EJH. Aminoacetone, a putative endogenous source of methylglyoxal, causes oxidative stress and death to insulin-producing RINm5f cells. Chem Res Toxicol 2008; 21:1841-50. [PMID: 18729331 DOI: 10.1021/tx8001753] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Aminoacetone (AA), triose phosphates, and acetone are putative endogenous sources of potentially cytotoxic and genotoxic methylglyoxal (MG), which has been reported to be augmented in the plasma of diabetic patients. In these patients, accumulation of MG derived from aminoacetone, a threonine and glycine catabolite, is inferred from the observed concomitant endothelial overexpression of circulating semicarbazide-sensitive amine oxidases. These copper-dependent enzymes catalyze the oxidation of primary amines, such as AA and methylamine, by molecular oxygen, to the corresponding aldehydes, NH4(+) ion and H2O2. We recently reported that AA aerobic oxidation to MG also takes place immediately upon addition of catalytic amounts of copper and iron ions. Taking into account that (i) MG and H2O2 are reportedly cytotoxic to insulin-producing cell lineages such as RINm5f and that (ii) the metal-catalyzed oxidation of AA is propagated by O2(*-) radical anion, we decided to investigate the possible pro-oxidant action of AA on these cells taken here as a reliable model system for pancreatic beta-cells. Indeed, we show that AA (0.10-5.0 mM) administration to RINm5f cultures induces cell death. Ferrous (50-300 microM) and Fe(3+) ion (100 microM) addition to the cell cultures had no effect, whereas Cu(2+) (5.0-100 microM) significantly increased cell death. Supplementation of the AA- and Cu(2+)-containing culture medium with antioxidants, such as catalase (5.0 microM), superoxide dismutase (SOD, 50 U/mL), and N-acetylcysteine (NAC, 5.0 mM) led to partial protection. mRNA expression of MnSOD, CuZnSOD, glutathione peroxidase, and glutathione reductase, but not of catalase, is higher in cells treated with AA (0.50-1.0 mM) plus Cu(2+) ions (10-50 microM) relative to control cultures. This may imply higher activity of antioxidant enzymes in RINm5f AA-treated cells. In addition, we have found that AA (0.50-1.0 mM) plus Cu(2+) (100 microM) (i) increase RINm5f cytosolic calcium; (ii) promote DNA fragmentation; and (iii) increase the pro-apoptotic (Bax)/antiapoptotic (Bcl-2) ratio at the level of mRNA expression. In conclusion, although both normal and pathological concentrations of AA are probably much lower than those used here, it is tempting to propose that excess AA in diabetic patients may drive oxidative damage and eventually the death of pancreatic beta-cells.
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Affiliation(s)
- Adriano Sartori
- Departamento de Bioquimica, Instituto de Quimica, Universidade de Sao Paulo, SP, Brazil
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Newly weaned nonobese diabetic mice show heightened early diabetes sensitivity to multiple low doses of streptozotocin than nondiabetes-prone CD-1 mice: initial beta-cell damage a key trigger for type 1 diabetes? Pancreas 2008; 37:e8-e19. [PMID: 18580436 DOI: 10.1097/mpa.0b013e3181661b1b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
OBJECTIVES We determined if newly weaned female nonobese diabetic (NOD) mice show greater diabetes sensitivity to dose-adjusted regimens of multiple low doses of streptozotocin (Stz) than nondiabetes-prone CD-1 mice. METHODS Female NOD mice received 5 daily doses of Stz from day 21 (0, 5, 10, 15, 20, 30, and 40 mg/kg body weight) and CD-1 mice 20, 30, and 40 mg. RESULTS : Streptozotocin, at the 15-, 20-, 30-, and 40-mg dose, induced rapid diabetes in NOD mice. By day 100, 90% to 95% of NOD mice became diabetic after the 40- and 30-mg dose and 33% to 40% with the 15- and 20-mg dose. In comparison, only about 50% and 33% of CD-1 mice developed diabetes with the 40- and 30-mg dose, respectively, and 5.5% with the 20-mg dose. In NOD mice, the 20-mg dose also partially suppressed spontaneous diabetes. All diabetic mice displayed insulitis, variable immunostaining for insulin, and redistribution of glucagon and somatostatin cells. Glucose transporter-2 was markedly attenuated in selective beta cells. CONCLUSIONS Newly weaned female NOD mice show heightened early sensitivity to low doses of Stz than CD-1 mice. At diabetes, several beta cells remain and show variable immunostaining for insulin and an attenuated expression for glucose transporter-2. Specific low doses of Stz may also suppress spontaneous diabetes.
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35
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Won KC, Yoon JS. Glucose Toxicity and Pancreatic Beta Cell Dysfunction in Type 2 Diabetes. KOREAN DIABETES JOURNAL 2008. [DOI: 10.4093/kdj.2008.32.3.175] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Kyu Chang Won
- Department of Internal Medicine, College of Medicine, Yeungnam University, Korea
| | - Ji Sung Yoon
- Department of Internal Medicine, College of Medicine, Yeungnam University, Korea
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36
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Abstract
Melatonin influences insulin secretion both in vivo and in vitro. (i) The effects are MT(1)-and MT(2)-receptor-mediated. (ii) They are specific, high-affinity, pertussis-toxin-sensitive, G(i)-protein-coupled, leading to inhibition of the cAMP-pathway and decrease of insulin release. [Correction added after online publication 4 December 2007: in the preceding sentence, 'increase of insulin release' was changed to 'decrease of insulin release'.] Furthermore, melatonin inhibits the cGMP-pathway, possibly mediated by MT(2) receptors. In this way, melatonin likely inhibits insulin release. A third system, the IP(3)-pathway, is mediated by G(q)-proteins, phospholipase C and IP(3), which mobilize Ca(2+) from intracellular stores, with a resultant increase in insulin. (iii) Insulin secretion in vivo, as well as from isolated islets, exhibits a circadian rhythm. This rhythm, which is apparently generated within the islets, is influenced by melatonin, which induces a phase shift in insulin secretion. (iv) Observation of the circadian expression of clock genes in the pancreas could possibly be an indication of the generation of circadian rhythms in the pancreatic islets themselves. (v) Melatonin influences diabetes and associated metabolic disturbances. The diabetogens, alloxan and streptozotocin, lead to selective destruction of beta-cells through their accumulation in these cells, where they induce the generation of ROS. Beta-cells are very susceptible to oxidative stress because they possess only low-antioxidative capacity. Results suggest that melatonin in pharmacological doses provides protection against ROS. (vi) Finally, melatonin levels in plasma, as well as the arylalkylamine-N-acetyltransferase (AANAT) activity, are lower in diabetic than in nondiabetic rats and humans. In contrast, in the pineal gland, the AANAT mRNA is increased and the insulin receptor mRNA is decreased, which indicates a close interrelationship between insulin and melatonin.
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Affiliation(s)
- Elmar Peschke
- Institute of Anatomy and Cell Biology, Martin Luther University Halle-Wittenberg, Germany.
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Meghana K, Sanjeev G, Ramesh B. Curcumin prevents streptozotocin-induced islet damage by scavenging free radicals: a prophylactic and protective role. Eur J Pharmacol 2007; 577:183-91. [PMID: 17900558 DOI: 10.1016/j.ejphar.2007.09.002] [Citation(s) in RCA: 120] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2007] [Revised: 08/28/2007] [Accepted: 09/03/2007] [Indexed: 11/23/2022]
Abstract
Pancreatic islet cell death is the cause of deficient insulin production in diabetes mellitus. Approaches towards prevention of cell death are of prophylactic importance in control and management of hyperglycemia. Generation of oxidative stress is implicated in streptozotocin, a beta cell specific toxin-induced islet cell death. In this context, antioxidants raise an interest for therapeutic purposes. Curcumin, a common dietary spice is a well known antioxidant and hence we investigated its effect on streptozotocin-induced islet damage in vitro. Isolated islets from C57/BL6J mice were incubated with curcumin for 24 h and later exposed to streptozotocin for 8 h. The effect of streptozotocin exposure to islets was determined with respect to islet viability and functionality, cellular reactive oxygen species concentrations and levels of activated poly (ADP-ribose) polymerase-1. Cellular antioxidant potential (Cu/Zn superoxide dismutase) and advanced glycation end-product related damage was assessed to determine the metabolic status of treated and untreated islets. Islet viability and secreted insulin in curcumin pretreated islets were significantly higher than islets exposed to streptozotocin alone. Curcumin retarded generation of islet reactive oxygen species along with inhibition of Poly ADP-ribose polymerase-1 activation. Although curcumin did not cause overexpression of Cu/Zn superoxide dismutase, it prevented reduction in levels of cellular free radical scavenging enzymes. Our data shows that curcumin protects islets against streptozotocin-induced oxidative stress by scavenging free radicals. We show here for the first time, that prophylactic use of curcumin may effectively rescue islets from damage without affecting the normal function of these cellular structures.
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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: 0.3] [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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39
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Shah S, Iqbal M, Karam J, Salifu M, McFarlane SI. Oxidative stress, glucose metabolism, and the prevention of type 2 diabetes: pathophysiological insights. Antioxid Redox Signal 2007; 9:911-29. [PMID: 17508914 DOI: 10.1089/ars.2007.1629] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
With the rising epidemic of type 2 diabetes worldwide, including the United States, the death and disability due to the suboptimal control of cardiovascular disease associated with this epidemic has made prevention of type 2 diabetes emerge as a primary strategic intervention. Several modalities have been assessed in large randomized controlled trials for diabetes prevention such as lifestyle interventions and various pharmacologic agents. Included in these agents are metformin, thiazolidinediones, acarbose, angiotensin converting enzyme inhibitors, as well as angiotensin receptor blockers. Abrogation of oxidative stress appears to be a common soil hypothesis that explains the favorable effects of these agents on glucose metabolism, including the prevention of diabetes and its complications. This comprehensive review highlights the role of oxidative stress in the pathogenesis of diabetes, with emphasis on the major clinical trials conducted on prevention of type 2 diabetes.
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Affiliation(s)
- Syed Shah
- Division of Endocrinology, Diabetes and Hypertension, Department of Internal Medicine, SUNY Downstate and Kings County Hospital Center, Brooklyn, NY 11203, USA
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40
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Moriscot C, Candel S, Sauret V, Kerr-Conte J, Richard MJ, Favrot MC, Benhamou PY. MnTMPyP, a metalloporphyrin-based superoxide dismutase/catalase mimetic, protects INS-1 cells and human pancreatic islets from an in vitro oxidative challenge. DIABETES & METABOLISM 2007; 33:44-53. [PMID: 17258921 DOI: 10.1016/j.diabet.2006.09.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2006] [Accepted: 09/02/2006] [Indexed: 11/17/2022]
Abstract
AIMS Pancreatic islets can be lost early following allotransplantation from oxidative stress. Antioxidant enzyme overexpression could confer a beneficial effect on islets exposed to reactive oxygen species (ROS) and nitrogen species. Here, we tested the effect of MnTMPyP, a superoxide dismutase/catalase mimetic. METHODS INS-1 insulin-secreting cells or human islets were cultured with MnTMPyP and exposed to a superoxide donor (the hypoxanthine/xanthine oxidase (HX/XO) system), a nitric oxide donor [3-morpholinosydnonimine (SIN-1)] or menadione. Viability of INS-1 cells was assessed by WST-1 colorimetric assay and FACS analysis (Live/Dead test). ROS production was determined using fluorescent probes. Islet viability was estimated by WST-1 assay and endocrine function by static incubation. RESULTS Following MnTMPyP treatment, ROS production in INS-1 cells was reduced by 4- to 20-fold upon HX/XO challenge and up to 2-fold upon SIN-1 stress. This phenomenon correlated with higher viability measured by WST-1 or Live/Dead test. MnTMPyP preserved islet viability upon exposure to SIN-1 or menadione but not upon an HX/XO challenge. Similarly, decrease in insulin secretion tended to be less pronounced in MnTMPyP-treated islets than in control islet when exposed to SIN-1, but no changes were noticed during an HX/XO stress. CONCLUSIONS MnTMPyP was able to improve the viability of INS-1 cells and human islets exposed to oxidative challenges in vitro. Protection of INS-1 cells could be as high as 90%. This agent is therefore potentially attractive in situations involving the overproduction of ROS, such as islet transplantation.
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Affiliation(s)
- C Moriscot
- Institut national de la santé et de la recherche médicale (Inserm), unité 578, Grenoble, France
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Reddy S, Chang M, Robinson E. Young NOD mice show increased diabetes sensitivity to low doses of streptozotocin. Ann N Y Acad Sci 2007; 1079:109-13. [PMID: 17130539 DOI: 10.1196/annals.1375.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
In type 1 diabetes, environmentally induced early-limited beta cell damage may pre-empt the subsequent immune-mediated beta cell destruction. Low doses of streptozotocin (Stz), given early to diabetes-prone mice, may cause limited beta cell destruction during the early phase and precipitate diabetes. Here, we aimed to see if young NOD mice are more diabetes-sensitive to various multiple low doses of Stz than non-diabetes-prone mice. We also determined the molecular pathology of islets following administration of the diabetogen. Female NOD and CD-1 mice received 5 daily doses of Stz at day 21 (20, 30, and 40 mg/kg body weight; 18 mice per group) or diluent, and diabetes was monitored. Pancreas were studied histochemically and immunohistochemically at various time points after Stz administration. Following administration of Stz, NOD mice showed a much earlier onset and increased diabetes rate, at all three doses, than CD-1 mice. By day 80, the final diabetes rates following the 40, 30, and 20 mg dose in NOD mice were 95%, 85%, and 33%, respectively, compared with 33%, 28%, and 5.5%, respectively, in CD-1 mice. However, following the 20 mg dose, only 2 of the 12 remaining NOD mice developed the disease between 90 and 250 days compared with 19 of 24 NOD mice that did not receive Stz at day 21. Stz-administered NOD and CD-1 mice showed an initial loss of beta cells, with redistribution of islet endocrine cells, early macrophage infiltration, and increasing insulitis.
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MESH Headings
- Animals
- Diabetes Mellitus, Experimental/chemically induced
- Diabetes Mellitus, Experimental/genetics
- Diabetes Mellitus, Experimental/metabolism
- Diabetes Mellitus, Type 1/epidemiology
- Diabetes Mellitus, Type 1/etiology
- Diabetes Mellitus, Type 1/immunology
- Diabetes Mellitus, Type 1/metabolism
- Diabetes Mellitus, Type 1/pathology
- Dose-Response Relationship, Drug
- Female
- Glucagon/metabolism
- Histocytochemistry
- Immunohistochemistry
- Incidence
- Insulin/metabolism
- Islets of Langerhans/immunology
- Islets of Langerhans/pathology
- Mice
- Mice, Inbred NOD
- Mice, Inbred Strains
- Streptozocin/administration & dosage
- Streptozocin/toxicity
- Time Factors
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Affiliation(s)
- Shiva Reddy
- School of Biological Sciences, University of Auckland, Auckland, New Zealand.
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42
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Kim EK, Kwon KB, Lee JH, Park BH, Park JW, Lee HK, Jhee EC, Yang JY. Inhibition of Cytokine-Mediated Nitric Oxide Synthase Expression in Rat Insulinoma Cells by Scoparone. Biol Pharm Bull 2007; 30:242-6. [PMID: 17268059 DOI: 10.1248/bpb.30.242] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Cytokines produced by immune cells infiltrating pancreatic islets are important mediators of beta-cell destruction in insulin-dependent diabetes mellitus. Scoparone (6,7-dimethoxycoumarin) is known to have a wide range of pharmacological properties in vitro. In this study, the effects of scoparone on cytokine-induced beta-cell dysfunction were examined. Presence of scoparone significantly protected interleukin-1beta (IL-1beta) and interferon-gamma (IFN-gamma)-mediated cytotoxicity of RINm5F, a rat insulinoma cell line, and preserved glucose-stimulated insulin secretion in rat pancreatic islets. Scoparone also resulted in a significant reduction in IL-1beta and IFN-gamma-induced nitric oxide (NO) production, a finding that correlated well with reduced levels of the inducible form of NO synthase (iNOS) mRNA and protein. The molecular mechanism by which scoparone inhibited iNOS gene expression appeared to involve the inhibition of NF-kappaB activation. These results revealed the possible therapeutic value of scoparone for the prevention of diabetes mellitus progression.
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Affiliation(s)
- Eun Kyung Kim
- Department of Biochemistry, Medical School, Chonbuk National University, Jeonju, Korea
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43
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Bloch K, Shichman E, Vorobeychik M, Bloch D, Vardi P. Catalase expression in pancreatic alpha cells of diabetic and non-diabetic mice. Histochem Cell Biol 2006; 127:227-32. [PMID: 17102991 DOI: 10.1007/s00418-006-0248-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/16/2006] [Indexed: 10/23/2022]
Abstract
The pancreatic islet beta cells are very sensitive to oxidative stress, probably due to the extremely low level of anti-oxidant enzymes, particularly catalase. In contrast to beta cells, pancreatic alpha cells are significantly more resistant to diabetogenic toxins. However, whether alpha cells express a different level of catalase is not known. The aim of this study was to evaluate catalase expression in alpha cells of diabetic and non-diabetic mice. Diabetes was induced by a single injection of streptozotocin. After 3 weeks of persistent hyperglycemia, pancreatic tissues were collected. Catalase localization in alpha cells was identified by a dual-immunofluorescence staining with anti-glucagon and anti-catalase antibodies. In intact mice, intensive catalase and glucagon immunostaining was found in the peripheral area of islets. Merged images of glucagon and catalase show their localization in the same cell type, namely, alpha cells. Confocal microscopy indicated that the glucagon and catalase staining was distributed throughout the cytoplasm. Similar co-expression of catalase and glucagon was found in the alpha cells of diabetic animals. The results of this study show the intensive catalase expression in alpha cells of diabetic and non-diabetic mice. This knowledge may be useful to better understand the defense mechanisms of pancreatic alpha cells against oxidative stress.
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Affiliation(s)
- Konstantin Bloch
- Diabetes and Obesity Research Laboratory, Felsenstein Medical Research Center, Sackler Faculty of Medicine, Tel-Aviv University, Petah Tikva, 49100, Israel.
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44
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Kwon KB, Kim EK, Jeong ES, Lee YH, Lee YR, Park JW, Ryu DG, Park BH. Cortex cinnamomi extract prevents streptozotocin- and cytokine-induced β-cell damage by inhibiting NF-κB. World J Gastroenterol 2006; 12:4331-7. [PMID: 16865774 PMCID: PMC4087743 DOI: 10.3748/wjg.v12.i27.4331] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To clarify the mechanism underlying the anti-diabetic activities of cortex cinnamomi extract (CCE).
METHODS: To induce in vivo diabetes, mice were injected with streptozotocin (STZ) via a tail vein (100 mg STZ/kg body weight). To determine the effects of CCE, mice were administered CCE twice daily for 7 d by oral gavage starting 1 wk before the STZ injection. Blood glucose and plasma insulin concentration were measured as an index of diabetes. Also, to induce cytotoxicity of RINm5F cells, we treated with cytokines (IL-1β (2.0 ng/mL) and IFN-γ (100 U/mL)). Cell viability and nitric oxide production were measured colorimetrically. Inducible nitric oxide synthase (iNOS) mRNA and protein expression were determined by RT-PCR and Western blotting, respectively. The activation of NF-κB was assayed by using gel mobility shift assays of nuclear extracts.
RESULTS: Treatment of mice with STZ resulted in hyperglycemia and hypoinsulinemia, which was further evidenced by immunohistochemical staining of islets. However, the diabetogenic effects of STZ were completely prevented when mice were pretreated with CCE. The inhibitory effect of CCE on STZ-induced hyperglycemia was mediated through the suppression of iNOS expression. In rat insulinoma RINm5F cells, CCE completely protected against interleukin-1β and interferon-γ-mediated cytotoxicity. Moreover, RINm5F cells incubated with CCE showed significant reductions in interleukin-1β and interferon-γ-induced nitric oxide production and in iNOS mRNA and protein expression, and these findings correlated well with in vivo observations.
CONCLUSION: The molecular mechanism by which CCE inhibits iNOS gene expression appears to involve the inhibition of NF-κB activation. These results reveal the possible therapeutic value of CCE for the prevention of diabetes mellitus progression.
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Affiliation(s)
- Kang-Beom Kwon
- Department of Physiology, School of Oriental Medicine, Wonkwang University, Iksan 570-749, South Korea
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45
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Won KC, Moon JS, Eun MJ, Yoon JS, Chun KA, Cho IH, Kim YW, Lee HW. A protective role for heme oxygenase-1 in INS-1 cells and rat islets that are exposed to high glucose conditions. J Korean Med Sci 2006; 21:418-24. [PMID: 16778382 PMCID: PMC2729944 DOI: 10.3346/jkms.2006.21.3.418] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/05/2022] Open
Abstract
Heme oxygenase-1 (HO-1) has been described as an inducible protein that is capable of cytoprotection via radical scavenging and the prevention of apoptosis. Chronic exposure to hyperglycemia can lead to cellular dysfunction that may become irreversible over time, and this process has been termed glucose toxicity. Yet little is known about the relation between glucose toxicity and HO-1 in the islets. The purposes of the present study were to determine whether prolonged exposure of pancreatic islets to a supraphysiologic glucose concentration disrupts the intracellular balance between reactive oxygen species (ROS) and HO-1, and so this causes defective insulin secretion; we also wanted to evaluate a protective role for HO-1 in pancreatic islets against high glucose levels. The intracellular peroxide levels of the pancreatic islets (INS-1 cell, rat islet) were increased in the high glucose media (30 mM glucose or 50 mM ribose). The HO-1 expression was induced in the INS-1 cells by the high glucose levels. Both the HO-1 expression and glucose stimulated insulin secretion (GSIS) was decreased simultaneously in the islets by treatment of the HO-1 antisense. The HO-1 was upregulated in the INS-1 cells by hemin, an inducer of HO-1. And, HO-1 upregulation induced by hemin reversed the GSIS in the islets at a high glucose condition. These results suggest HO-1 seems to mediate the protective response of pancreatic islets against the oxidative stress that is due to high glucose conditions.
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Affiliation(s)
- Kyu Chang Won
- Department of Internal Medicine, College of Medicine, Yeungnam University, Daegu, Korea.
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46
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Zraika S, Aston-Mourney K, Laybutt DR, Kebede M, Dunlop ME, Proietto J, Andrikopoulos S. The influence of genetic background on the induction of oxidative stress and impaired insulin secretion in mouse islets. Diabetologia 2006; 49:1254-63. [PMID: 16570159 DOI: 10.1007/s00125-006-0212-9] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2005] [Accepted: 12/23/2005] [Indexed: 10/24/2022]
Abstract
AIMS/HYPOTHESIS We determined whether high-glucose-induced beta cell dysfunction is associated with oxidative stress in the DBA/2 mouse, a mouse strain susceptible to islet failure. MATERIALS AND METHODS Glucose- and non-glucose-mediated insulin secretion from the islets of DBA/2 and control C57BL/6 mice was determined following a 48-h exposure to high glucose. Flux via the hexosamine biosynthesis pathway was assessed by determining O-glycosylated protein levels. Oxidative stress was determined by measuring hydrogen peroxide levels and the expression of anti-oxidant enzymes. RESULTS Exposure to high glucose levels impaired glucose-stimulated insulin secretion in DBA/2 islets but not C57BL/6 islets, and this was associated with reduced islet insulin content and lower ATP levels than in C57BL/6 islets. Exposure of islets to glucosamine for 48 h mimicked the effects of high glucose on insulin secretion in the DBA/2 islets. High glucose exposure elevated O-glycosylated proteins; however, this occurred in islets from both strains, excluding a role for O-glycosylation in the impairment of DBA/2 insulin secretion. Additionally, both glucosamine and high glucose caused an increase in hydrogen peroxide in DBA/2 islets but not in C57BL/6 islets, an effect prevented by the antioxidant N-acetyl-L: -cysteine. Interestingly, while glutathione peroxidase and catalase expression was comparable between the two strains, the antioxidant enzyme manganese superoxide dismutase, which converts superoxide to hydrogen peroxide, was increased in DBA/2 islets, possibly explaining the increase in hydrogen peroxide levels. CONCLUSIONS/INTERPRETATION Chronic high glucose culture caused an impairment in glucose-stimulated insulin secretion in DBA/2 islets, which have a genetic predisposition to failure, and this may be the result of oxidative stress.
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Affiliation(s)
- S Zraika
- Department of Medicine (AH/NH), University of Melbourne, Heidelberg Repatriation Hospital, Heidelberg Heights, VIC 3081, Australia
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47
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Yoshioka Y, Kitao T, Kishino T, Yamamuro A, Maeda S. Nitric oxide protects macrophages from hydrogen peroxide-induced apoptosis by inducing the formation of catalase. THE JOURNAL OF IMMUNOLOGY 2006; 176:4675-81. [PMID: 16585560 DOI: 10.4049/jimmunol.176.8.4675] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
We investigated the cytoprotective effect of NO on H2O2-induced cell death in mouse macrophage-like cell line RAW264. H2O2-treated cells showed apoptotic features, such as activation of caspase-9 and caspase-3, nuclear fragmentation, and DNA fragmentation. These apoptotic features were significantly inhibited by pretreatment for 24 h with NO donors, sodium nitroprusside and 1-hydroxy-2-oxo-3,3-bis-(2-aminoethyl)-1-triazene, at a low nontoxic concentration. The cytoprotective effect of NO was abrogated by the catalase inhibitor 3-amino-1,2,4-triazole but was not affected by a glutathione synthesis inhibitor, L-buthionine-(S,R)-sulfoximine. NO donors increased the level of catalase and its activity in a concentration-dependent manner. Cycloheximide, a protein synthesis inhibitor, inhibited both the NO-induced increase in the catalase level and the cytoprotective effect of NO. These results indicate that NO at a low concentration protects macrophages from H2O2-induced apoptosis by inducing the production of catalase.
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Affiliation(s)
- Yasuhiro Yoshioka
- Department of Pharmacotherapeutics, Faculty of Pharmaceutical Sciences, Setsunan University, Hirakata, Osaka, Japan.
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48
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McCabe C, Samali A, O'Brien T. Cytoprotection of beta cells: rational gene transfer strategies. Diabetes Metab Res Rev 2006; 22:241-52. [PMID: 16397906 DOI: 10.1002/dmrr.615] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Gene transfer to pancreatic islets may prove useful in preventing islet cell destruction and prolonging islet graft survival after transplantation in patients with type 1 diabetes mellitus (T1DM). Potentially, a host of therapeutically relevant transgenes may be incorporated into an appropriate gene delivery vehicle and used for islet modification. An increasing understanding of the molecular pathogenesis of immune-mediated beta cell death has served to highlight molecules which have become suitable candidates for promoting islet cell survival in the face of oxidative stress. This review aims to give an overview of some conventional gene transfer strategies aimed at promoting islet cell survival in the face of cytokine onslaught. These strategies target three aspects of islet cell physiology: redox status and antioxidant defence, anti-apoptotic gene expression and mediators of cytokine signal transduction pathways.
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Affiliation(s)
- Cillian McCabe
- Regenerative Medicine Institute, National Centre for Biomedical Engineering Sciences, National University of Ireland Galway, Galway, Ireland
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49
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McCabe C, Samali A, O'brien T. beta cell cytoprotective strategies: establishing the relative roles for iNOS and ROS. Biochem Biophys Res Commun 2006; 342:1240-8. [PMID: 16516156 DOI: 10.1016/j.bbrc.2006.02.092] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2006] [Accepted: 02/16/2006] [Indexed: 11/21/2022]
Abstract
Cytokine-induced beta cell destruction may be mediated by the generation of nitric oxide and/or reactive oxygen species. The relative importance of NO and ROS in cytokine-induced beta cell pathophysiology remains unclear. This investigation evaluates and contrasts the cytoprotective potential of antioxidant gene transfer, versus NF-kappaB inhibition, using a degradation-resistant mutant of IkappaBalpha. NF-kappaB inhibition conferred significant protection against cytokine-induced damage whereas antioxidant overexpression failed to provide protection. Conferred cytoprotection was associated with a suppression of iNOS activation and nitrite accumulation. Our data implicates iNOS, as opposed to ROS, as the pivotal player in cytokine-induced beta cell damage. From a therapeutic standpoint, strategies aimed at targeting the activation of iNOS may harbor therapeutic potential in preserving beta cell survival in the face of 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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50
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Bekris LM, Shephard C, Peterson M, Hoehna J, Van Yserloo B, Rutledge E, Farin F, Kavanagh TJ, Lernmark A. Glutathione-s-transferase M1 and T1 polymorphisms and associations with type 1 diabetes age-at-onset. Autoimmunity 2006; 38:567-75. [PMID: 16390810 DOI: 10.1080/08916930500407238] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Type 1 diabetes (T1D) is an autoimmune disease characterized by pancreatic beta cell destruction involving auto-reactive T-cells, pro-inflammatory cytokines, reactive oxygen species (ROS) and loss of insulin. Monozygotic twin studies show a 20-60% concordance with T1D indicating there may be an environmental component to the disease. Glutathione (GSH) is the major endogenous antioxidant produced by the cell. GSH participates directly in the neutralization of free radicals and plays a role in the immune response. Glutathione-s-transferases (GSTs) conjugate GSH to free-radicals or xenobiotics. GST activity depletes GSH levels and may either detoxify or enhance the toxicity of a compound. Glutathione-s-transferase mu 1 (GSTM1) and glutathione-s-transferase theta 1 (GSTT1) have polymorphic homozygous deletion (null) genotypes resulting in complete absence of enzyme activity. GSTM1 and GSTT1 null genotypes in Caucasian populations have frequencies of approximately 40-60% and 15-20%, respectively. GST null genotypes have been associated with susceptibility to cancer and protection against chronic pancreatitis. The aim of this study was to investigate associations with GSTM1 and GSTT1 polymorphisms in a group T1D patients and control subjects 0-35 years old who participated in the Combined Swedish Childhood Diabetes Registry and Diabetes Incidence Study (1986-1988). Results show that the presence of the GSTM1 and not the null genotype (OR, 2.13 95% CI, 1.23-3.70, p-value, 0.007, Bonferroni corrected p-value, 0.035) may be a susceptibility factor in T1D 14-20 years old. These results suggest that the GSTM1 null genotype is associated with T1D protection and T1D age-at-onset and that susceptibility to T1D may involve GST conjugation.
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Affiliation(s)
- Lynn M Bekris
- Department of Environmental and Occupational Health Sciences, University of Washington, Box 357710, Seattle, WA 98195, USA.
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