1
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Eileen L, Peterson M. High-Fat Diets Fed during Pregnancy Cause Changes to Pancreatic Tissue DNA Methylation and Protein Expression in the Offspring: A Multi-Omics Approach. Int J Mol Sci 2024; 25:7317. [PMID: 39000422 PMCID: PMC11242410 DOI: 10.3390/ijms25137317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2024] [Revised: 06/28/2024] [Accepted: 06/29/2024] [Indexed: 07/16/2024] Open
Abstract
Maternal obesity, caused by diets rich in fats and sugars during pregnancy, can predispose offspring to metabolic diseases such as diabetes. We hypothesized that obesity during pregnancy leads to increased DNA methylation and reduced protein expression in factors regulating β-cell function and apoptosis. Female C57BL/6J mice were fed a high-fat diet (HFD; 42% fat content; n = 3) or a control diet (CON; 16% fat content; n = 3) for fourteen weeks before and during pregnancy. Offspring were euthanized at 8 weeks and pancreatic tissue was collected. Isolated DNA was analyzed using whole-genome bisulfite sequencing. Protein expression was quantified using LC-MS. No significant differences in body weight were observed between HFD and control pups (p = 0.10). Whole-genome bisulfite sequencing identified 91,703 and 88,415 differentially methylated regions (DMRs) in CON vs. HFD male and female offspring. A total of 34 and 4 proteins were determined to have changes in expression that correlated with changes in DNA methylation in CON vs. HFD males and females, respectively. The majority of these factors were grouped into the metabolic function category via pathway analyses. This study illustrates the complex relationship between epigenetics, diet, and sex-specific responses, therefore offering insights into potential therapeutic targets and areas for further research.
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Affiliation(s)
| | - Maria Peterson
- Department of Fisheries, Veterinary, and Animal Science, University of Rhode Island, 45 Upper College Rd., Kingston, RI 02881, USA;
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2
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Reed J, Higginbotham V, Bain S, Kanamarlapudi V. Comparative Analysis of Orthosteric and Allosteric GLP-1R Agonists' Effects on Insulin Secretion from Healthy, Diabetic, and Recovered INS-1E Pancreatic Beta Cells. Int J Mol Sci 2024; 25:6331. [PMID: 38928038 PMCID: PMC11203424 DOI: 10.3390/ijms25126331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Revised: 06/01/2024] [Accepted: 06/03/2024] [Indexed: 06/28/2024] Open
Abstract
Despite the availability of different treatments for type 2 diabetes (T2D), post-diagnosis complications remain prevalent; therefore, more effective treatments are desired. Glucagon-like peptide (GLP)-1-based drugs are currently used for T2D treatment. They act as orthosteric agonists for the GLP-1 receptor (GLP-1R). In this study, we analyzed in vitro how the GLP-1R orthosteric and allosteric agonists augment glucose-stimulated insulin secretion (GSIS) and intracellular cAMP production (GSICP) in INS-1E pancreatic beta cells under healthy, diabetic, and recovered states. The findings from this study suggest that allosteric agonists have a longer duration of action than orthosteric agonists. They also suggest that the GLP-1R agonists do not deplete intracellular insulin, indicating they can be a sustainable and safe treatment option for T2D. Importantly, this study demonstrates that the GLP-1R agonists variably augment GSIS through GSICP in healthy, diabetic, and recovered INS-1E cells. Furthermore, we find that INS-1E cells respond differentially to the GLP-1R agonists depending on both glucose concentration during and before treatment and/or whether the cells have been previously exposed to these drugs. In conclusion, the findings described in this manuscript will be useful in determining in vitro how pancreatic beta cells respond to T2D drug treatments in healthy, diabetic, and recovered states.
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Affiliation(s)
| | | | | | - Venkateswarlu Kanamarlapudi
- Institute of Life Science, Medical School, Swansea University, Singleton Park, Swansea SA2 8PP, UK; (J.R.); (V.H.); (S.B.)
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3
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Fontcuberta-PiSunyer M, García-Alamán A, Prades È, Téllez N, Alves-Figueiredo H, Ramos-Rodríguez M, Enrich C, Fernandez-Ruiz R, Cervantes S, Clua L, Ramón-Azcón J, Broca C, Wojtusciszyn A, Montserrat N, Pasquali L, Novials A, Servitja JM, Vidal J, Gomis R, Gasa R. Direct reprogramming of human fibroblasts into insulin-producing cells using transcription factors. Commun Biol 2023; 6:256. [PMID: 36964318 PMCID: PMC10039074 DOI: 10.1038/s42003-023-04627-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 02/24/2023] [Indexed: 03/26/2023] Open
Abstract
Direct lineage reprogramming of one somatic cell into another without transitioning through a progenitor stage has emerged as a strategy to generate clinically relevant cell types. One cell type of interest is the pancreatic insulin-producing β cell whose loss and/or dysfunction leads to diabetes. To date it has been possible to create β-like cells from related endodermal cell types by forcing the expression of developmental transcription factors, but not from more distant cell lineages like fibroblasts. In light of the therapeutic benefits of choosing an accessible cell type as the cell of origin, in this study we set out to analyze the feasibility of transforming human skin fibroblasts into β-like cells. We describe how the timed-introduction of five developmental transcription factors (Neurog3, Pdx1, MafA, Pax4, and Nkx2-2) promotes conversion of fibroblasts toward a β-cell fate. Reprogrammed cells exhibit β-cell features including β-cell gene expression and glucose-responsive intracellular calcium mobilization. Moreover, reprogrammed cells display glucose-induced insulin secretion in vitro and in vivo. This work provides proof-of-concept of the capacity to make insulin-producing cells from human fibroblasts via transcription factor-mediated direct reprogramming.
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Affiliation(s)
| | - Ainhoa García-Alamán
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
- CIBER de Diabetes y Enfermedades Metabólicas Asociadas, Instituto de Salud Carlos III, Madrid, Spain
| | - Èlia Prades
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Noèlia Téllez
- CIBER de Diabetes y Enfermedades Metabólicas Asociadas, Instituto de Salud Carlos III, Madrid, Spain
- Faculty of Medicine of University of Vic, Central University of Catalonia (UVic-UCC), Vic, Spain
- Institute of Health Research and Innovation at Central Catalonia (IRIS-CC), Vic, Spain
| | - Hugo Alves-Figueiredo
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
- Tecnológico de Monterrey, Escuela de Medicina y Ciencias de la Salud, Monterrey, N.L., México
| | | | - Carlos Enrich
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
- Faculty of Medicine and Health Sciences, Universitat de Barcelona, Barcelona, Spain
| | - Rebeca Fernandez-Ruiz
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
- CIBER de Diabetes y Enfermedades Metabólicas Asociadas, Instituto de Salud Carlos III, Madrid, Spain
| | - Sara Cervantes
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Laura Clua
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Technology (BIST), Barcelona, Spain
| | - Javier Ramón-Azcón
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Technology (BIST), Barcelona, Spain
- Catalan Institution for Research and Advanced Studies (ICREA), Barcelona, Spain
| | - Christophe Broca
- CHU Montpellier, Laboratory of Cell Therapy for Diabetes (LTCD), Hospital St-Eloi, Montpellier, France
| | - Anne Wojtusciszyn
- CHU Montpellier, Laboratory of Cell Therapy for Diabetes (LTCD), Hospital St-Eloi, Montpellier, France
- Service of Endocrinology, Diabetes and Metabolism, Lausanne University Hospital, Lausanne, Switzerland
| | - Nuria Montserrat
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Technology (BIST), Barcelona, Spain
- Catalan Institution for Research and Advanced Studies (ICREA), Barcelona, Spain
- CIBER de Bioingeniería, Biomateriales y Nanomedicina, Instituto de Salud Carlos III, Madrid, Spain
| | - Lorenzo Pasquali
- Department of Medicine and Life Sciences, Universitat Pompeu Fabra, Barcelona, Spain
| | - Anna Novials
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
- CIBER de Diabetes y Enfermedades Metabólicas Asociadas, Instituto de Salud Carlos III, Madrid, Spain
| | - Joan-Marc Servitja
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
- CIBER de Diabetes y Enfermedades Metabólicas Asociadas, Instituto de Salud Carlos III, Madrid, Spain
| | - Josep Vidal
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
- CIBER de Diabetes y Enfermedades Metabólicas Asociadas, Instituto de Salud Carlos III, Madrid, Spain
- Faculty of Medicine and Health Sciences, Universitat de Barcelona, Barcelona, Spain
- Endocrinology and Nutrition Department, Hospital Clinic of Barcelona, Barcelona, Spain
| | - Ramon Gomis
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
- CIBER de Diabetes y Enfermedades Metabólicas Asociadas, Instituto de Salud Carlos III, Madrid, Spain
- Faculty of Medicine and Health Sciences, Universitat de Barcelona, Barcelona, Spain
| | - Rosa Gasa
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.
- CIBER de Diabetes y Enfermedades Metabólicas Asociadas, Instituto de Salud Carlos III, Madrid, Spain.
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4
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Svikle Z, Peterfelde B, Sjakste N, Baumane K, Verkauskiene R, Jeng CJ, Sokolovska J. Ubiquitin-proteasome system in diabetic retinopathy. PeerJ 2022; 10:e13715. [PMID: 35873915 PMCID: PMC9306563 DOI: 10.7717/peerj.13715] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 06/21/2022] [Indexed: 01/22/2023] Open
Abstract
Diabetic retinopathy (DR) is the most common complication of diabetes, being the most prevalent reason for blindness among the working-age population in the developed world. Despite constant improvement of understanding of the pathogenesis of DR, identification of novel biomarkers of DR is needed for improvement of patient risk stratification and development of novel prevention and therapeutic approaches. The ubiquitin-proteasome system (UPS) is the primary protein quality control system responsible for recognizing and degrading of damaged proteins. This review aims to summarize literature data on modifications of UPS in diabetes and DR. First, we briefly review the structure and functions of UPS in physiological conditions. We then describe how UPS is involved in the development and progression of diabetes and touch upon the association of UPS genetic factors with diabetes and its complications. Further, we focused on the effect of diabetes-induced hyperglycemia, oxidative stress and hypoxia on UPS functioning, with examples of studies on DR. In other sections, we discussed the association of several other mechanisms of DR (endoplasmic reticulum stress, neurodegeneration etc) with UPS modifications. Finally, UPS-affecting drugs and remedies are reviewed. This review highlights UPS as a promising target for the development of therapies for DR prevention and treatment and identifies gaps in existing knowledge and possible future study directions.
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Affiliation(s)
- Zane Svikle
- Faculty of Medicine, University of Latvia, Riga, Latvia
| | - Beate Peterfelde
- Faculty of Medicine, University of Latvia, Riga, Latvia,Ophthalmology Department, Riga East University Hospital, Riga, Latvia
| | | | - Kristine Baumane
- Faculty of Medicine, University of Latvia, Riga, Latvia,Ophthalmology Department, Riga East University Hospital, Riga, Latvia
| | - Rasa Verkauskiene
- Institute of Endocrinology, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Chi-Juei Jeng
- Ophthalmology Department, Taipei Medical University Shuang Ho Hospital, Ministry of Health and Welfare, Taipei, The Republic of China (Taiwan),College of Medicine, Graduate Institute of Clinical Medicine, National Taiwan University, Taipei, Taiwan
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5
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Liu QR, Aseer KR, Yao Q, Zhong X, Ghosh P, O’Connell JF, Egan JM. Anti-Inflammatory and Pro-Autophagy Effects of the Cannabinoid Receptor CB2R: Possibility of Modulation in Type 1 Diabetes. Front Pharmacol 2022; 12:809965. [PMID: 35115945 PMCID: PMC8804091 DOI: 10.3389/fphar.2021.809965] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Accepted: 12/21/2021] [Indexed: 11/13/2022] Open
Abstract
Type 1 diabetes mellitus (T1DM) is an autoimmune disease resulting from loss of insulin-secreting β-cells in islets of Langerhans. The loss of β-cells is initiated when self-tolerance to β-cell-derived contents breaks down, which leads to T cell-mediated β-cell damage and, ultimately, β-cell apoptosis. Many investigations have demonstrated the positive effects of antagonizing cannabinoid receptor 1 (CB1R) in metabolic diseases such as fatty liver disease, obesity, and diabetes mellitus, but the role of cannabinoid receptor 2 (CB2R) in such diseases is relatively unknown. Activation of CB2R is known for its immunosuppressive roles in multiple sclerosis, rheumatoid arthritis, Crohn’s, celiac, and lupus diseases, and since autoimmune diseases can share common environmental and genetic factors, we propose CB2R specific agonists may also serve as disease modifiers in diabetes mellitus. The CNR2 gene, which encodes CB2R protein, is the result of a gene duplication of CNR1, which encodes CB1R protein. This ortholog evolved rapidly after transitioning from invertebrates to vertebrate hundreds of million years ago. Human specific CNR2 isoforms are induced by inflammation in pancreatic islets, and a CNR2 nonsynonymous SNP (Q63R) is associated with autoimmune diseases. We collected evidence from the literature and from our own studies demonstrating that CB2R is involved in regulating the inflammasome and especially release of the cytokine interleukin 1B (IL-1β). Furthermore, CB2R activation controls intracellular autophagy and may regulate secretion of extracellular vesicles from adipocytes that participate in recycling of lipid droplets, dysregulation of which induces chronic inflammation and obesity. CB2R activation may play a similar role in islets of Langerhans. Here, we will discuss future strategies to unravel what roles, if any, CB2R modifiers potentially play in T1DM.
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Affiliation(s)
- Qing-Rong Liu
- Laboratory of Clinical Investigation, National Institute on Aging, NIH, Baltimore, MD, United States
- *Correspondence: Qing-Rong Liu, ; Josephine M. Egan,
| | - Kanikkai Raja Aseer
- Laboratory of Clinical Investigation, National Institute on Aging, NIH, Baltimore, MD, United States
| | - Qin Yao
- Laboratory of Clinical Investigation, National Institute on Aging, NIH, Baltimore, MD, United States
| | - Xiaoming Zhong
- Ben May Department for Cancer Research, The University of Chicago, Chicago, IL, United States
| | - Paritosh Ghosh
- Laboratory of Clinical Investigation, National Institute on Aging, NIH, Baltimore, MD, United States
| | - Jennifer F. O’Connell
- Laboratory of Clinical Investigation, National Institute on Aging, NIH, Baltimore, MD, United States
| | - Josephine M. Egan
- Laboratory of Clinical Investigation, National Institute on Aging, NIH, Baltimore, MD, United States
- *Correspondence: Qing-Rong Liu, ; Josephine M. Egan,
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6
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You S, Zheng J, Chen Y, Huang H. Research progress on the mechanism of beta-cell apoptosis in type 2 diabetes mellitus. Front Endocrinol (Lausanne) 2022; 13:976465. [PMID: 36060972 PMCID: PMC9434279 DOI: 10.3389/fendo.2022.976465] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Accepted: 08/01/2022] [Indexed: 11/23/2022] Open
Abstract
Type 2 diabetes mellitus(T2DM) is regarded as one of the most severe chronic metabolic diseases worldwide, which poses a great threat to human safety and health. The main feature of T2DM is the deterioration of pancreatic beta-cell function. More and more studies have shown that the decline of pancreatic beta-cell function in T2DM can be attributable to beta-cell apoptosis, but the exact mechanisms of beta-cell apoptosis in T2DM are not yet fully clarified. Therefore, in this review, we will focus on the current status and progress of research on the mechanism of pancreatic beta-cell apoptosis in T2DM, to provide new ideas for T2DM treatment strategies.
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Affiliation(s)
- SuFang You
- The Second Clinical Medical College of Fujian Medical University, Quanzhou, China
- Department of Endocrinology, The Second Affiliated Hospital of Fujian Medical University, Quanzhou, China
| | - JingYi Zheng
- Department of Endocrinology, The Second Affiliated Hospital of Fujian Medical University, Quanzhou, China
| | - YuPing Chen
- Department of Endocrinology, The Second Affiliated Hospital of Fujian Medical University, Quanzhou, China
| | - HuiBin Huang
- Department of Endocrinology, The Second Affiliated Hospital of Fujian Medical University, Quanzhou, China
- *Correspondence: HuiBin Huang,
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7
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Blood Immunoproteasome Activity Is Regulated by Sex, Age and in Chronic Inflammatory Diseases: A First Population-Based Study. Cells 2021; 10:cells10123336. [PMID: 34943847 PMCID: PMC8699521 DOI: 10.3390/cells10123336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 11/21/2021] [Accepted: 11/25/2021] [Indexed: 11/30/2022] Open
Abstract
Dysfunction of the immunoproteasome has been implicated in cardiovascular and pulmonary diseases. Its potential as a biomarker for predicting disease stages, however, has not been investigated so far and population-based analyses on the impact of sex and age are missing. We here analyzed the activity of all six catalytic sites of the proteasome in isolated peripheral blood mononuclear cells obtained from 873 study participants of the KORA FF4 study using activity-based probes. The activity of the immuno- and standard proteasome correlated clearly with elevated leukocyte counts of study participants. Unexpectedly, we observed a strong sex dimorphism for proteasome activity with significantly lower immunoproteasome activity in women. In aging, almost all catalytic activities of the proteasome were activated in aged women while maintained upon aging in men. We also noted distinct sex-related activation patterns of standard and immunoproteasome active sites in chronic inflammatory diseases such as diabetes, cardiovascular diseases, asthma, or chronic obstructive pulmonary disease as determined by multiple linear regression modeling. Our data thus provides a conceptual framework for future analysis of immunoproteasome function as a bio-marker for chronic inflammatory disease development and progression.
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8
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Metabolic impacts of cordycepin on hepatic proteomic expression in streptozotocin-induced type 1 diabetic mice. PLoS One 2021; 16:e0256140. [PMID: 34388207 PMCID: PMC8363009 DOI: 10.1371/journal.pone.0256140] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Accepted: 07/29/2021] [Indexed: 12/12/2022] Open
Abstract
Type 1 Diabetes mellitus (T1DM) is associated with abnormal liver function, but the exact mechanism is unclear. Cordycepin improves hepatic metabolic pathways leading to recovery from liver damage. We investigated the effects of cordycepin in streptozotocin-induced T1DM mice via the expression of liver proteins. Twenty-four mice were divided into four equal groups: normal (N), normal mice treated with cordycepin (N+COR), diabetic mice (DM), and diabetic mice treated with cordycepin (DM+COR). Mice in each treatment group were intraperitoneally injection of cordycepin at dose 24 mg/kg for 14 consecutive days. Body weight, blood glucose, and the tricarboxylic acid cycle intermediates were measured. Liver tissue protein profiling was performed using shotgun proteomics, while protein function and protein-protein interaction were predicted using PANTHER and STITCH v.5.0 software, respectively. No significant difference was observed in fasting blood glucose levels between DM and DM+COR for all time intervals. However, a significant decrease in final body weight, food intake, and water intake in DM+COR was found. Hepatic oxaloacetate and citrate levels were significantly increased in DM+COR compared to DM. Furthermore, 11 and 36 proteins were only expressed by the N+COR and DM+COR groups, respectively. Three unique proteins in DM+COR, namely, Nfat3, Flcn, and Psma3 were correlated with the production of ATP, AMPK signaling pathway, and ubiquitin proteasome system (UPS), respectively. Interestingly, a protein detected in N+COR and DM+COR (Gli3) was linked with the insulin signaling pathway. In conclusion, cordycepin might help in preventing hepatic metabolism by regulating the expression of energy-related protein and UPS to maintain cell survival. Further work on predicting the performance of metabolic mechanisms regarding the therapeutic applications of cordycepin will be performed in future.
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Mechanisms of Beta-Cell Apoptosis in Type 2 Diabetes-Prone Situations and Potential Protection by GLP-1-Based Therapies. Int J Mol Sci 2021; 22:ijms22105303. [PMID: 34069914 PMCID: PMC8157542 DOI: 10.3390/ijms22105303] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 05/07/2021] [Accepted: 05/13/2021] [Indexed: 12/22/2022] Open
Abstract
Type 2 diabetes (T2D) is characterized by chronic hyperglycemia secondary to the decline of functional beta-cells and is usually accompanied by a reduced sensitivity to insulin. Whereas altered beta-cell function plays a key role in T2D onset, a decreased beta-cell mass was also reported to contribute to the pathophysiology of this metabolic disease. The decreased beta-cell mass in T2D is, at least in part, attributed to beta-cell apoptosis that is triggered by diabetogenic situations such as amyloid deposits, lipotoxicity and glucotoxicity. In this review, we discussed the molecular mechanisms involved in pancreatic beta-cell apoptosis under such diabetes-prone situations. Finally, we considered the molecular signaling pathways recruited by glucagon-like peptide-1-based therapies to potentially protect beta-cells from death under diabetogenic situations.
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10
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Milardi D, Gazit E, Radford SE, Xu Y, Gallardo RU, Caflisch A, Westermark GT, Westermark P, Rosa CL, Ramamoorthy A. Proteostasis of Islet Amyloid Polypeptide: A Molecular Perspective of Risk Factors and Protective Strategies for Type II Diabetes. Chem Rev 2021; 121:1845-1893. [PMID: 33427465 DOI: 10.1021/acs.chemrev.0c00981] [Citation(s) in RCA: 116] [Impact Index Per Article: 38.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The possible link between hIAPP accumulation and β-cell death in diabetic patients has inspired numerous studies focusing on amyloid structures and aggregation pathways of this hormone. Recent studies have reported on the importance of early oligomeric intermediates, the many roles of their interactions with lipid membrane, pH, insulin, and zinc on the mechanism of aggregation of hIAPP. The challenges posed by the transient nature of amyloid oligomers, their structural heterogeneity, and the complex nature of their interaction with lipid membranes have resulted in the development of a wide range of biophysical and chemical approaches to characterize the aggregation process. While the cellular processes and factors activating hIAPP-mediated cytotoxicity are still not clear, it has recently been suggested that its impaired turnover and cellular processing by proteasome and autophagy may contribute significantly toward toxic hIAPP accumulation and, eventually, β-cell death. Therefore, studies focusing on the restoration of hIAPP proteostasis may represent a promising arena for the design of effective therapies. In this review we discuss the current knowledge of the structures and pathology associated with hIAPP self-assembly and point out the opportunities for therapy that a detailed biochemical, biophysical, and cellular understanding of its aggregation may unveil.
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Affiliation(s)
- Danilo Milardi
- Istituto di Cristallografia, Consiglio Nazionale delle Ricerche, Via P. Gaifami 18, 95126 Catania, Italy
| | - Ehud Gazit
- Department of Molecular Microbiology and Biotechnology, The Shmunis School of Biomedicine and Cancer Research, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Sheena E Radford
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Yong Xu
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Rodrigo U Gallardo
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Amedeo Caflisch
- Department of Biochemistry, University of Zürich, Zürich CH-8057, Switzerland
| | - Gunilla T Westermark
- Department of Medical Cell Biology, Uppsala University, SE-751 23 Uppsala, Sweden
| | - Per Westermark
- Department of Immunology, Genetics and Pathology, Uppsala University, SE-751 85 Uppsala, Sweden
| | - Carmelo La Rosa
- Dipartimento di Scienze Chimiche, Università degli Studi di Catania, Viale Andrea Doria 6, 95125 Catania, Italy
| | - Ayyalusamy Ramamoorthy
- Biophysics, Department of Chemistry, Biomedical Engineering, Macromolecular Science and Engineering, University of Michigan, Ann Arbor, Michigan 41809-1055, United States
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11
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Shared Blood Transcriptomic Signatures between Alzheimer's Disease and Diabetes Mellitus. Biomedicines 2021; 9:biomedicines9010034. [PMID: 33406707 PMCID: PMC7823888 DOI: 10.3390/biomedicines9010034] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 12/29/2020] [Accepted: 12/30/2020] [Indexed: 12/29/2022] Open
Abstract
Alzheimer’s disease (AD) and diabetes mellitus (DM) are known to have a shared molecular mechanism. We aimed to identify shared blood transcriptomic signatures between AD and DM. Blood expression datasets for each disease were combined and a co-expression network was used to construct modules consisting of genes with similar expression patterns. For each module, a gene regulatory network based on gene expression and protein-protein interactions was established to identify hub genes. We selected one module, where COPS4, PSMA6, GTF2B, GTF2F2, and SSB were identified as dysregulated transcription factors that were common between AD and DM. These five genes were also differentially co-expressed in disease-related tissues, such as the brain in AD and the pancreas in DM. Our study identified gene modules that were dysregulated in both AD and DM blood samples, which may contribute to reveal common pathophysiology between two diseases.
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12
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Wisp1 is a circulating factor that stimulates proliferation of adult mouse and human beta cells. Nat Commun 2020; 11:5982. [PMID: 33239617 PMCID: PMC7689468 DOI: 10.1038/s41467-020-19657-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Accepted: 10/16/2020] [Indexed: 12/12/2022] Open
Abstract
Expanding the mass of pancreatic insulin-producing beta cells through re-activation of beta cell replication has been proposed as a therapy to prevent or delay the appearance of diabetes. Pancreatic beta cells exhibit an age-dependent decrease in their proliferative activity, partly related to changes in the systemic environment. Here we report the identification of CCN4/Wisp1 as a circulating factor more abundant in pre-weaning than in adult mice. We show that Wisp1 promotes endogenous and transplanted adult beta cell proliferation in vivo. We validate these findings using isolated mouse and human islets and find that the beta cell trophic effect of Wisp1 is dependent on Akt signaling. In summary, our study reveals the role of Wisp1 as an inducer of beta cell replication, supporting the idea that the use of young blood factors may be a useful strategy to expand adult beta cell mass. The proliferation of pancreatic beta cells decreases with age, partly due to systemic changes. Here the authors identify Wisp1 as a circulating factor enriched in young serum that induces adult beta cell proliferation, supporting the idea that young blood factors may be useful to expand beta cell mass.
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13
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Schepici G, Bramanti P, Mazzon E. Efficacy of Sulforaphane in Neurodegenerative Diseases. Int J Mol Sci 2020; 21:ijms21228637. [PMID: 33207780 PMCID: PMC7698208 DOI: 10.3390/ijms21228637] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2020] [Revised: 11/10/2020] [Accepted: 11/14/2020] [Indexed: 12/14/2022] Open
Abstract
Sulforaphane (SFN) is a phytocompound belonging to the isothiocyanate family. Although it was also found in seeds and mature plants, SFN is mainly present in sprouts of many cruciferous vegetables, including cabbage, broccoli, cauliflower, and Brussels sprouts. SFN is produced by the conversion of glucoraphanin through the enzyme myrosinase, which leads to the formation of this isothiocyanate. SFN is especially characterized by antioxidant, anti-inflammatory, and anti-apoptotic properties, and for this reason, it aroused the interest of researchers. The aim of this review is to summarize the experimental studies present on Pubmed that report the efficacy of SFN in the treatment of neurodegenerative disease, including Alzheimer’s disease (AD), Parkinson’s disease (PD), and multiple sclerosis (MS). Therefore, thanks to its beneficial effects, SFN could be useful as a supplement to counteracting neurodegenerative diseases.
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14
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Figueiredo H, Figueroa ALC, Garcia A, Fernandez-Ruiz R, Broca C, Wojtusciszyn A, Malpique R, Gasa R, Gomis R. Targeting pancreatic islet PTP1B improves islet graft revascularization and transplant outcomes. Sci Transl Med 2020; 11:11/497/eaar6294. [PMID: 31217339 DOI: 10.1126/scitranslmed.aar6294] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Revised: 01/16/2019] [Accepted: 05/23/2019] [Indexed: 12/12/2022]
Abstract
Deficient vascularization is a major driver of early islet graft loss and one of the primary reasons for the failure of islet transplantation as a viable treatment for type 1 diabetes. This study identifies the protein tyrosine phosphatase 1B (PTP1B) as a potential modulator of islet graft revascularization. We demonstrate that grafts of pancreatic islets lacking PTP1B exhibit increased revascularization, which is accompanied by improved graft survival and function, and recovery of normoglycemia and glucose tolerance in diabetic mice transplanted with PTP1B-deficient islets. Mechanistically, we show that the absence of PTP1B leads to activation of hypoxia-inducible factor 1α-independent peroxisome proliferator-activated receptor γ coactivator 1α/estrogen-related receptor α signaling and enhanced expression and production of vascular endothelial growth factor A (VEGF-A) by β cells. These observations were reproduced in human islets. Together, these findings reveal that PTP1B regulates islet VEGF-A production and suggest that this phosphatase could be targeted to improve islet transplantation outcomes.
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Affiliation(s)
- Hugo Figueiredo
- Diabetes and Obesity Research Laboratory, August Pi i Sunyer Biomedical Research Institute (IDIBAPS), 08036 Barcelona, Spain.,University of Barcelona, 08036 Barcelona, Spain.,Escuela de Medicina y Ciencias de la Salud, Dept. Medicina Cardiovascular y Metabolómica, Tecnológico de Monterrey, 66278 San Pedro Garza García, Nuevo León, Mexico
| | - Ana Lucia C Figueroa
- Diabetes and Obesity Research Laboratory, August Pi i Sunyer Biomedical Research Institute (IDIBAPS), 08036 Barcelona, Spain.,University of Barcelona, 08036 Barcelona, Spain
| | - Ainhoa Garcia
- Diabetes and Obesity Research Laboratory, August Pi i Sunyer Biomedical Research Institute (IDIBAPS), 08036 Barcelona, Spain.,Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 28029 Madrid, Spain
| | - Rebeca Fernandez-Ruiz
- Diabetes and Obesity Research Laboratory, August Pi i Sunyer Biomedical Research Institute (IDIBAPS), 08036 Barcelona, Spain.,Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 28029 Madrid, Spain
| | - Christophe Broca
- CHU Montpellier, Laboratory of Cell Therapy for Diabetes (LTCD), Hospital St-Eloi, 34295 Montpellier, France
| | - Anne Wojtusciszyn
- CHU Montpellier, Laboratory of Cell Therapy for Diabetes (LTCD), Hospital St-Eloi, 34295 Montpellier, France.,Department of Endocrinology, Diabetes and Nutrition, University Hospital of Montpellier, Lapeyronie Hospital, 34295 Montpellier, France.,Service of Endocrinology, Diabetes and Metabolism, Lausanne University Hospital, 1011 Lausanne, Switzerland
| | - Rita Malpique
- Diabetes and Obesity Research Laboratory, August Pi i Sunyer Biomedical Research Institute (IDIBAPS), 08036 Barcelona, Spain
| | - Rosa Gasa
- Diabetes and Obesity Research Laboratory, August Pi i Sunyer Biomedical Research Institute (IDIBAPS), 08036 Barcelona, Spain. .,Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 28029 Madrid, Spain
| | - Ramon Gomis
- Diabetes and Obesity Research Laboratory, August Pi i Sunyer Biomedical Research Institute (IDIBAPS), 08036 Barcelona, Spain. .,University of Barcelona, 08036 Barcelona, Spain.,Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), 28029 Madrid, Spain.,Universitat Oberta de Catalunya (UOC), 08018 Barcelona, Spain.,Department of Endocrinology and Nutrition, Hospital Clinic of Barcelona, 08036 Barcelona, Spain
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15
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Homma T, Fujii J. Emerging connections between oxidative stress, defective proteolysis, and metabolic diseases. Free Radic Res 2020; 54:931-946. [DOI: 10.1080/10715762.2020.1734588] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Takujiro Homma
- Department of Biochemistry and Molecular Biology, Graduate School of Medical Science, Yamagata University, Yamagata, Japan
| | - Junichi Fujii
- Department of Biochemistry and Molecular Biology, Graduate School of Medical Science, Yamagata University, Yamagata, Japan
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16
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Doumatey AP, Adeyemo A, Zhou J, Lei L, Adebamowo SN, Adebamowo C, Rotimi CN. Gut Microbiome Profiles Are Associated With Type 2 Diabetes in Urban Africans. Front Cell Infect Microbiol 2020; 10:63. [PMID: 32158702 PMCID: PMC7052266 DOI: 10.3389/fcimb.2020.00063] [Citation(s) in RCA: 78] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Accepted: 02/07/2020] [Indexed: 01/04/2023] Open
Abstract
Gut dysbiosis has been associated with several disease outcomes including diabetes in human populations. Currently, there are no studies of the gut microbiome composition in relation to type 2 diabetes (T2D) in Africans. Here, we describe the profile of the gut microbiome in non-diabetic adults (controls) and investigate the association between gut microbiota and T2D in urban West Africans. Gut microbiota composition was determined in 291 Nigerians (98 cases, 193 controls) using fecal 16S V4 rRNA gene sequencing done on the Illumina MiSeq platform. Data analysis of operational taxonomic units (OTU) was conducted to describe microbiome composition and identify differences between T2D and controls. The most abundant phyla were Firmicutes, Actinobacteria, and Bacteroidetes. Clostridiaceae, and Peptostreptococcaceaea were significantly lower in cases than controls (p < 0.001). Feature selection analysis identified a panel of 18 OTUs enriched in cases that included Desulfovibrio piger, Prevotella, Peptostreptococcus, and Eubacterium. A panel of 17 OTUs that was enriched in the controls included Collinsella, Ruminococcus lactaris, Anaerostipes, and Clostridium. OTUs with strain-level annotation showing the largest fold-change included Cellulosilyticum ruminicola (log2FC = −3.1; p = 4.2 × 10−5), Clostridium paraputrificum (log2FC = −2.5; p = 0.005), and Clostridium butyricum (log2FC = −1.76; p = 0.01), all lower in cases. These findings are notable because supplementation with Clostridium butyricum and Desulfovibrio piger has been shown to improve hyperglycemia and reduce insulin resistance in murine models. This first investigation of gut microbiome and diabetes in urban Africans shows that T2D is associated with compositional changes in gut microbiota highlighting the possibility of developing strategies to improve glucose control by modifying bacterial composition in the gut.
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Affiliation(s)
- Ayo P Doumatey
- Center for Research on Genomics and Global Health, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, United States
| | - Adebowale Adeyemo
- Center for Research on Genomics and Global Health, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, United States
| | - Jie Zhou
- Center for Research on Genomics and Global Health, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, United States
| | - Lin Lei
- Center for Research on Genomics and Global Health, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, United States
| | - Sally N Adebamowo
- Department of Epidemiology and Public Health and Greenebaum Comprehensive Cancer Center, University of Maryland School of Medicine, Baltimore, MD, United States.,Center for Bioethics and Research, Ibadan, Nigeria
| | - Clement Adebamowo
- Department of Epidemiology and Public Health and Greenebaum Comprehensive Cancer Center, University of Maryland School of Medicine, Baltimore, MD, United States.,Center for Bioethics and Research, Ibadan, Nigeria.,Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Charles N Rotimi
- Center for Research on Genomics and Global Health, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, United States
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17
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Duvigneau JC, Esterbauer H, Kozlov AV. Role of Heme Oxygenase as a Modulator of Heme-Mediated Pathways. Antioxidants (Basel) 2019; 8:antiox8100475. [PMID: 31614577 PMCID: PMC6827082 DOI: 10.3390/antiox8100475] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 09/27/2019] [Accepted: 10/07/2019] [Indexed: 02/07/2023] Open
Abstract
The heme oxygenase (HO) system is essential for heme and iron homeostasis and necessary for adaptation to cell stress. HO degrades heme to biliverdin (BV), carbon monoxide (CO) and ferrous iron. Although mostly beneficial, the HO reaction can also produce deleterious effects, predominantly attributed to excessive product formation. Underrated so far is, however, that HO may exert effects additionally via modulation of the cellular heme levels. Heme, besides being an often-quoted generator of oxidative stress, plays also an important role as a signaling molecule. Heme controls the anti-oxidative defense, circadian rhythms, activity of ion channels, glucose utilization, erythropoiesis, and macrophage function. This broad spectrum of effects depends on its interaction with proteins ranging from transcription factors to enzymes. In degrading heme, HO has the potential to exert effects also via modulation of heme-mediated pathways. In this review, we will discuss the multitude of pathways regulated by heme to enlarge the view on HO and its role in cell physiology. We will further highlight the contribution of HO to pathophysiology, which results from a dysregulated balance between heme and the degradation products formed by HO.
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Affiliation(s)
- J Catharina Duvigneau
- Institute for Medical Biochemistry, University of Veterinary Medicine, Veterinaerplatz 1, 1210 Vienna, Austria.
| | - Harald Esterbauer
- Department of Laboratory Medicine, Medical University of Vienna, 1210 Vienna, Austria.
| | - Andrey V Kozlov
- Ludwig Boltzmann Institute for Experimental and Clinical Traumatology, 1200 Vienna, Austria.
- Laboratory of Navigational Redox Lipidomics, Department of Human Pathology, IM Sechenov Moscow State Medical University, 119992 Moscow, Russia.
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18
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Thomaidou S, Zaldumbide A, Roep BO. Islet stress, degradation and autoimmunity. Diabetes Obes Metab 2018; 20 Suppl 2:88-94. [PMID: 30230178 PMCID: PMC6174957 DOI: 10.1111/dom.13387] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Revised: 05/18/2018] [Accepted: 05/30/2018] [Indexed: 12/15/2022]
Abstract
β-cell destruction in type 1 diabetes (T1D) results from the effect of inflammation and autoimmunity. In response to inflammatory signals, islet cells engage adaptive mechanisms to restore and maintain cellular homeostasis. Among these mechanisms, the unfolded protein response (UPR) leads to a reduction of the general protein translation rate, increased production of endoplasmic reticulum chaperones and the initiation of degradation by activation of the ER associated degradation pathway (ERAD) in which newly synthetized proteins are ubiquitinylated and processed through the proteasome. This adaptive phase is also believed to play a critical role in the development of autoimmunity by the generation of neoantigens. While we have previously investigated the effect of stress on transcription, translation and post-translational events as possible source for neoantigens, the participation of the degradation machinery, yet crucial in the generation of antigenic peptides, remains to be investigated in the context of T1D pathology. In this review, we will describe the relation between the unfolded protein response and the Ubiquitin Proteasome System (UPS) and address the role of the cellular degradation machinery in the generation of antigens. Learning from tumour immunology, we propose how these processes may unmask β-cells by triggering the generation of aberrant peptides recognized by the immune cells.
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Affiliation(s)
- Sofia Thomaidou
- Department of Cell and Chemical BiologyLeiden University Medical CenterLeidenThe Netherlands
| | - Arnaud Zaldumbide
- Department of Cell and Chemical BiologyLeiden University Medical CenterLeidenThe Netherlands
| | - Bart O. Roep
- Department of Immunohematology and Blood bank Leiden University Medical CenterLeiden University Medical CenterLeidenThe Netherlands
- Department of Diabetes ImmunologyDiabetes & Metabolism Research Institute at the Beckman Research InstituteDuarteCalifornia
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19
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Chatterjee Bhowmick D, Jeremic A. Functional proteasome complex is required for turnover of islet amyloid polypeptide in pancreatic β-cells. J Biol Chem 2018; 293:14210-14223. [PMID: 30012886 DOI: 10.1074/jbc.ra118.002414] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 07/02/2018] [Indexed: 12/16/2022] Open
Abstract
Human islet amyloid polypeptide (hIAPP) is the principal constituent of amyloid deposits and toxic oligomers in the pancreatic islets. Together with hyperglycemia, hIAPP-derived oligomers and aggregates are important culprits in type 2 diabetes mellitus (T2DM). Here, we explored the role of the cell's main proteolytic complex, the proteasome, in hIAPP turnover in normal and stressed β-cells evoked by chronic hyperglycemia. Moderate inhibition (10-35%) of proteasome activity/function in cultured human islets by the proteasome inhibitor lactacystin enhanced intracellular accumulation of hIAPP. Unexpectedly, prolonged (>1 h) and marked (>50%) impairment of proteasome activity/function had a strong inhibitory effect on hIAPP transcription and secretion from normal and stressed β-cells. This negative compensatory feedback mechanism for controlling IAPP turnover was also observed in the lactacystin-treated rat insulinoma β-cell line (INS 832/13), demonstrating the presence of an evolutionarily conserved mechanism for IAPP production. In line with these in situ studies, our current ex vivo data showed that proteasome activity and hIAPP expression are also down-regulated in islets isolated from T2DM subjects. Gene expression and promoter activity studies demonstrated that the functional proteasome complex is required for efficient activation of the hIAPP promoter and for full expression of IAPP's essential transcription factor, FOXA2. ChIP studies revealed that promoter occupancy of FoxA2 at the rat IAPP promoter region is an important and limiting factor for amylin expression in proteasome-impaired murine cells. This study suggests a novel regulatory pathway in β-cells involving proteasome, FOXA2, and IAPP, which can be possibly targeted to regulate hIAPP levels and islet amyloidosis in T2DM.
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Affiliation(s)
- Diti Chatterjee Bhowmick
- From the Departments of Biological Sciences and Biomedical Sciences, George Washington University, Washington, D. C. 20052
| | - Aleksandar Jeremic
- From the Departments of Biological Sciences and Biomedical Sciences, George Washington University, Washington, D. C. 20052
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20
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An SCF FBXO28 E3 Ligase Protects Pancreatic β-Cells from Apoptosis. Int J Mol Sci 2018; 19:ijms19040975. [PMID: 29587369 PMCID: PMC5979299 DOI: 10.3390/ijms19040975] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Revised: 03/21/2018] [Accepted: 03/22/2018] [Indexed: 01/09/2023] Open
Abstract
Loss of pancreatic β-cell function and/or mass is a central hallmark of all forms of diabetes but its molecular basis is incompletely understood. β-cell apoptosis contributes to the reduced β-cell mass in diabetes. Therefore, the identification of important signaling molecules that promote β-cell survival in diabetes could lead to a promising therapeutic intervention to block β-cell decline during development and progression of diabetes. In the present study, we identified F-box protein 28 (FBXO28), a substrate-recruiting component of the Skp1-Cul1-F-box (SCF) ligase complex, as a regulator of pancreatic β-cell survival. FBXO28 was down-regulated in β-cells and in isolated human islets under diabetic conditions. Consistently, genetic silencing of FBXO28 impaired β-cell survival, and restoration of FBXO28 protected β-cells from the harmful effects of the diabetic milieu. Although FBXO28 expression positively correlated with β-cell transcription factor NEUROD1 and FBXO28 depletion also reduced insulin mRNA expression, neither FBXO28 overexpression nor depletion had any significant impact on insulin content, glucose-stimulated insulin secretion (GSIS) or on other genes involved in glucose sensing and metabolism or on important β-cell transcription factors in isolated human islets. Consistently, FBXO28 overexpression did not further alter insulin content and GSIS in freshly isolated islets from patients with type 2 diabetes (T2D). Our data show that FBXO28 improves pancreatic β-cell survival under diabetogenic conditions without affecting insulin secretion, and its restoration may be a novel therapeutic tool to promote β-cell survival in diabetes.
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21
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Gorrepati KDD, Lupse B, Annamalai K, Yuan T, Maedler K, Ardestani A. Loss of Deubiquitinase USP1 Blocks Pancreatic β-Cell Apoptosis by Inhibiting DNA Damage Response. iScience 2018; 1:72-86. [PMID: 30227958 PMCID: PMC6135944 DOI: 10.1016/j.isci.2018.02.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 01/31/2018] [Accepted: 02/01/2018] [Indexed: 01/09/2023] Open
Abstract
Impaired pancreatic β-cell survival contributes to the reduced β-cell mass in diabetes, but underlying regulatory mechanisms and key players in this process remain incompletely understood. Here, we identified the deubiquitinase ubiquitin-specific protease 1 (USP1) as an important player in the regulation of β-cell apoptosis under diabetic conditions. Genetic silencing and pharmacological suppression of USP1 blocked β-cell death in several experimental models of diabetes in vitro and ex vivo without compromising insulin content and secretion and without impairing β-cell maturation/identity genes in human islets. Our further analyses showed that USP1 inhibition attenuated DNA damage response (DDR) signals, which were highly elevated in diabetic β-cells, suggesting a USP1-dependent regulation of DDR in stressed β-cells. Our findings highlight a novel function of USP1 in the control of β-cell survival, and its inhibition may have a potential therapeutic relevance for the suppression of β-cell death in diabetes. Genetic and chemical inhibition of USP1 promoted β-cell survival USP1 inhibitors blocked β-cell death in human islets without affecting β-cell function USP1 inhibition reduced DDR signals in stressed β-cells
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Affiliation(s)
- Kanaka Durga Devi Gorrepati
- Islet Biology Laboratory, University of Bremen, Centre for Biomolecular Interactions Bremen, Leobener Straße NW2, Room B2080, 28359 Bremen, Germany
| | - Blaz Lupse
- Islet Biology Laboratory, University of Bremen, Centre for Biomolecular Interactions Bremen, Leobener Straße NW2, Room B2080, 28359 Bremen, Germany
| | - Karthika Annamalai
- Islet Biology Laboratory, University of Bremen, Centre for Biomolecular Interactions Bremen, Leobener Straße NW2, Room B2080, 28359 Bremen, Germany
| | - Ting Yuan
- Islet Biology Laboratory, University of Bremen, Centre for Biomolecular Interactions Bremen, Leobener Straße NW2, Room B2080, 28359 Bremen, Germany
| | - Kathrin Maedler
- Islet Biology Laboratory, University of Bremen, Centre for Biomolecular Interactions Bremen, Leobener Straße NW2, Room B2080, 28359 Bremen, Germany.
| | - Amin Ardestani
- Islet Biology Laboratory, University of Bremen, Centre for Biomolecular Interactions Bremen, Leobener Straße NW2, Room B2080, 28359 Bremen, Germany.
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22
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Miao X, Gu Z, Liu Y, Jin M, Lu Y, Gong Y, Li L, Li C. The glucagon-like peptide-1 analogue liraglutide promotes autophagy through the modulation of 5'-AMP-activated protein kinase in INS-1 β-cells under high glucose conditions. Peptides 2018; 100:127-139. [PMID: 28712893 DOI: 10.1016/j.peptides.2017.07.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 07/04/2017] [Accepted: 07/07/2017] [Indexed: 01/07/2023]
Abstract
Glucagon-like peptide-1 (GLP-1) is a potent therapeutic agent for the treatment of diabetes and has been proven to protect pancreatic β-cells from glucotoxicity; however, its mechanisms of action are not entirely understood. Autophagy is a dynamic lysosomal degradation process that can protect organisms against metabolic stress. Studies have shown that autophagy plays a protective role in the survival of pancreatic β-cells under high glucose conditions. In the present study, we explored the role of autophagy in GLP-1-induced protection of pancreatic β-cells exposed to high glucose. We demonstrated that the GLP-1 analogue liraglutide increased autophagy in rat INS-1 β-cells, and inhibition of autophagy abated the anti-apoptosis effect of liraglutide under high glucose conditions. Our results also showed that activation of 5'-AMP-activated protein kinase (AMPK) reduced liraglutide-induced autophagy enhancement and inhibited liraglutide-induced protection of INS-1 β-cells from high glucose. These data suggest that GLP-1 may protect β-cells from glucotoxicity through promoting autophagy by the modulation of AMPK. Deeper insight into the molecular mechanisms linking autophagy and GLP-1-induced β-cell protection may reveal novel therapeutic targets to preserve β-cell mass.
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Affiliation(s)
- Xinyu Miao
- Department of Geriatric Endocrinology, General Hospital of PLA, Beijing, China
| | - Zhaoyan Gu
- Department of Geriatric Endocrinology, General Hospital of PLA, Beijing, China
| | - Yu Liu
- Department of Geriatric Endocrinology, General Hospital of PLA, Beijing, China
| | - Mengmeng Jin
- Department of Geriatric Endocrinology, General Hospital of PLA, Beijing, China
| | - Yanhui Lu
- Department of Geriatric Endocrinology, General Hospital of PLA, Beijing, China
| | - Yanping Gong
- Department of Geriatric Endocrinology, General Hospital of PLA, Beijing, China
| | - Lin Li
- Department of Endocrinology, General Hospital of The PLA Rocket Force, Beijing, China
| | - Chunlin Li
- Department of Geriatric Endocrinology, General Hospital of PLA, Beijing, China.
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Rojas J, Bermudez V, Palmar J, Martínez MS, Olivar LC, Nava M, Tomey D, Rojas M, Salazar J, Garicano C, Velasco M. Pancreatic Beta Cell Death: Novel Potential Mechanisms in Diabetes Therapy. J Diabetes Res 2018; 2018:9601801. [PMID: 29670917 PMCID: PMC5836465 DOI: 10.1155/2018/9601801] [Citation(s) in RCA: 98] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Revised: 11/15/2017] [Accepted: 12/06/2017] [Indexed: 02/07/2023] Open
Abstract
PURPOSE OF REVIEW Describing the diverse molecular mechanisms (particularly immunological) involved in the death of the pancreatic beta cell in type 1 and type 2 diabetes mellitus. RECENT FINDINGS Beta cell death is the final event in a series of mechanisms that, up to date, have not been entirely clarified; it represents the pathophysiological mechanism in the natural history of diabetes mellitus. These mechanisms are not limited to an apoptotic process only, which is characteristic of the immune-mediated insulitis in type 1 diabetes mellitus. They also include the action of proinflammatory cytokines, the production of reactive oxygen species, DNA fragmentation (typical of necroptosis in type 1 diabetic patients), excessive production of islet amyloid polypeptide with the consequent endoplasmic reticulum stress, disruption in autophagy mechanisms, and protein complex formation, such as the inflammasome, capable of increasing oxidative stress produced by mitochondrial damage. SUMMARY Necroptosis, autophagy, and pyroptosis are molecular mechanisms that modulate the survival of the pancreatic beta cell, demonstrating the importance of the immune system in glucolipotoxicity processes and the potential role for immunometabolism as another component of what once known as the "ominous octet."
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Affiliation(s)
- Joselyn Rojas
- Pulmonary and Critical Care Medicine Department, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
- Endocrine and Metabolic Research Center, University of Zulia, Maracaibo, Venezuela
| | - Valmore Bermudez
- Endocrine and Metabolic Research Center, University of Zulia, Maracaibo, Venezuela
- Grupo de Investigación Altos Estudios de Frontera (ALEF), Universidad Simón Bolívar, Cúcuta, Colombia
| | - Jim Palmar
- Endocrine and Metabolic Research Center, University of Zulia, Maracaibo, Venezuela
| | - María Sofía Martínez
- Endocrine and Metabolic Research Center, University of Zulia, Maracaibo, Venezuela
| | - Luis Carlos Olivar
- Endocrine and Metabolic Research Center, University of Zulia, Maracaibo, Venezuela
| | - Manuel Nava
- Endocrine and Metabolic Research Center, University of Zulia, Maracaibo, Venezuela
| | - Daniel Tomey
- Endocrine and Metabolic Research Center, University of Zulia, Maracaibo, Venezuela
| | - Milagros Rojas
- Endocrine and Metabolic Research Center, University of Zulia, Maracaibo, Venezuela
| | - Juan Salazar
- Endocrine and Metabolic Research Center, University of Zulia, Maracaibo, Venezuela
| | - Carlos Garicano
- Grupo de Investigación Altos Estudios de Frontera (ALEF), Universidad Simón Bolívar, Cúcuta, Colombia
| | - Manuel Velasco
- Clinical Pharmacology Unit. School of Medicine José María Vargas, Central University of Venezuela, Caracas, Venezuela
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Oxidative Stress-Responsive Apoptosis Inducing Protein (ORAIP) Plays a Critical Role in High Glucose-Induced Apoptosis in Rat Cardiac Myocytes and Murine Pancreatic β-Cells. Cells 2017; 6:cells6040035. [PMID: 29057797 PMCID: PMC5755494 DOI: 10.3390/cells6040035] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Revised: 10/13/2017] [Accepted: 10/15/2017] [Indexed: 12/30/2022] Open
Abstract
We previously identified a novel apoptosis-inducing humoral factor in the conditioned medium of hypoxic/reoxygenated-cardiac myocytes. We named this novel post-translationally-modified secreted-form of eukaryotic translation initiation factor 5A Oxidative stress-Responsive Apoptosis-Inducing Protein (ORAIP). We confirmed that myocardial ischemia/reperfusion markedly increased plasma ORAIP levels and rat myocardial ischemia/reperfusion injury was clearly suppressed by neutralizing anti-ORAIP monoclonal antibodies (mAbs) in vivo. In this study, to investigate the mechanism of cell injury of cardiac myocytes and pancreatic β-cells involved in diabetes mellitus (DM), we analyzed plasma ORAIP levels in DM model rats and the role of ORAIP in high glucose-induced apoptosis of cardiac myocytes in vitro. We also examined whether recombinant-ORAIP induces apoptosis in pancreatic β-cells. Plasma ORAIP levels in DM rats during diabetic phase were about 18 times elevated as compared with non-diabetic phase. High glucose induced massive apoptosis in cardiac myocytes (66.2 ± 2.2%), which was 78% suppressed by neutralizing anti-ORAIP mAb in vitro. Furthermore, recombinant-ORAIP clearly induced apoptosis in pancreatic β-cells in vitro. These findings strongly suggested that ORAIP plays a pivotal role in hyperglycemia-induced myocardial injury and pancreatic β-cell injury in DM. ORAIP will be a biomarker and a critical therapeutic target for cardiac injury and progression of DM itself.
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Shruthi K, Reddy SS, Reddy GB. Ubiquitin-proteasome system and ER stress in the retina of diabetic rats. Arch Biochem Biophys 2017; 627:10-20. [PMID: 28606465 DOI: 10.1016/j.abb.2017.06.006] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Revised: 06/02/2017] [Accepted: 06/08/2017] [Indexed: 12/29/2022]
Abstract
PURPOSE Diabetic retinopathy (DR) is the most frequently occurring complication of diabetes. Alterations in ubiquitin-proteasome system (UPS) have been associated with several degenerative disorders. Hence, in this study, we investigated the status and role of UPS and ER stress in the retina of diabetic rats. METHODS Diabetes was induced in rats by streptozotocin. Retinal markers, ER stress markers, components of UPS, ERAD, and autophagy were analyzed after 2- and 4-months of diabetes. Apoptosis was analyzed by TUNEL Assay. RESULTS There were increased acellular capillaries and pericyte loss in diabetic rat retina. Decreased protein expression of UPS components - ubiquitin activating enzyme (E1), deubiquitinating enzymes (UCHL1 and UCHL5), SIAH1 (E3 ligase) and free ubiquitin were observed in the diabetic rats. Increased ER stress markers (ATF6, XBP1, and CHOP), decreased expression of HRD1, declined autophagy (LC3B) and increased apoptosis were observed in diabetic rats. Interestingly, treatment of diabetic rats with a chemical chaperone (4-PBA) restored the levels of DUBs and ameliorated ER stress-induced retinal cell death in type 1 diabetic rats. CONCLUSION The declined UPS components: E1 and HRD1 in the retina of diabetic rats could elicit ER stress, and the prolonged ER stress may trigger CHOP-mediated neuronal apoptosis.
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Affiliation(s)
- Karnam Shruthi
- Biochemistry Division, National Institute of Nutrition, Hyderabad, India
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Lundh M, Bugliani M, Dahlby T, Chou DHC, Wagner B, Ghiasi SM, De Tata V, Chen Z, Lund MN, Davies MJ, Marchetti P, Mandrup-Poulsen T. The immunoproteasome is induced by cytokines and regulates apoptosis in human islets. J Endocrinol 2017; 233:369-379. [PMID: 28438776 PMCID: PMC5501413 DOI: 10.1530/joe-17-0110] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Accepted: 04/24/2017] [Indexed: 12/11/2022]
Abstract
In addition to degrading misfolded and damaged proteins, the proteasome regulates the fate of cells in response to stress. The role of the proteasome in pro-inflammatory cytokine-induced human beta-cell apoptosis is unknown. Using INS-1, INS-1E and human islets exposed to combinations of IFNγ, IL-1β and TNFα with or without addition of small molecules, we assessed the role of the immunoproteasome in pancreatic beta-cell demise. Here, we show that cytokines induce the expression and activity of the immuno-proteasome in INS-1E cells and human islets. Cytokine-induced expression of immuno-proteasome subunits, but not activity, depended upon histone deacetylase 3 activation. Inhibition of JAK1/STAT1 signaling did not affect proteasomal activity. Inhibition of the immuno-proteasome subunit PSMB8 aggravated cytokine-induced human beta-cell apoptosis while reducing intracellular levels of oxidized proteins in INS-1 cells. While cytokines increased total cellular NFκB subunit P50 and P52 levels and reduced the cytosolic NFκB subunit P65 and IκB levels, these effects were unaffected by PSMB8 inhibition. We conclude that beta cells upregulate immuno-proteasome expression and activity in response to IFNγ, likely as a protective response to confine inflammatory signaling.
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Affiliation(s)
- Morten Lundh
- Department of Biomedical SciencesUniversity of Copenhagen, Copenhagen, Denmark
- Chemical Biology and Therapeutics ProgramBroad Institute of Harvard and MIT, Boston, Massachusetts, USA
| | - Marco Bugliani
- Department of Clinical and Experimental MedicineUniversity of Pisa, Pisa, Italy
| | - Tina Dahlby
- Department of Biomedical SciencesUniversity of Copenhagen, Copenhagen, Denmark
| | - Danny Hung-Chieh Chou
- Chemical Biology and Therapeutics ProgramBroad Institute of Harvard and MIT, Boston, Massachusetts, USA
| | - Bridget Wagner
- Chemical Biology and Therapeutics ProgramBroad Institute of Harvard and MIT, Boston, Massachusetts, USA
| | | | - Vincenzo De Tata
- Department of Biomedical SciencesUniversity of Copenhagen, Copenhagen, Denmark
| | - Zhifei Chen
- Department of Biomedical SciencesUniversity of Copenhagen, Copenhagen, Denmark
| | - Marianne Nissan Lund
- Department of Biomedical SciencesUniversity of Copenhagen, Copenhagen, Denmark
- Department of Food ScienceUniversity of Copenhagen, Copenhagen, Denmark
| | - Michael J Davies
- Department of Biomedical SciencesUniversity of Copenhagen, Copenhagen, Denmark
| | - Piero Marchetti
- Department of Clinical and Experimental MedicineUniversity of Pisa, Pisa, Italy
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Sjakste T, Paramonova N, Osina K, Dokane K, Sokolovska J, Sjakste N. Genetic variations in the PSMA3, PSMA6 and PSMC6 genes are associated with type 1 diabetes in Latvians and with expression level of number of UPS-related and T1DM-susceptible genes in HapMap individuals. Mol Genet Genomics 2015; 291:891-903. [PMID: 26661414 DOI: 10.1007/s00438-015-1153-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Accepted: 11/28/2015] [Indexed: 01/04/2023]
Abstract
The ubiquitin-proteasome system (UPS), a key player of proteostasis network in the body, was implicated in type 1 diabetes mellitus (T1DM) pathogenesis. Polymorphisms in genes encoding proteasome subunits may potentially affect system efficiency. However, data in this field are still limited. To fulfil this gap, single nucleotide polymorphisms in the PSMB5 (rs11543947), PSMA6 (rs2277460, rs1048990), PSMC6 (rs2295826, rs2295827) and PSMA3 (rs2348071) genes were genotyped on susceptibility to T1DM in Latvians. The rs11543947 was found to be neutral and other loci manifested disease susceptibility, with rs1048990 and rs2348071 being the most significantly associated (P < 0.001; OR 2.042 [1.376-3.032] and OR 2.096 [1.415-3.107], respectively). Risk effect was associated with female phenotype for rs2277460 and family history for rs2277460, rs2295826 and rs2295827. Five-locus genotypes being at risk simultaneously at any two or more loci showed strong (P < 0.0001) T1DM association. The T1DM protective effects (P < 0.001) were shown for five-locus genotype and haplotype homozygous on common alleles and composed of common alleles, respectively. Using SNPexp data set, correlations have been revealed between the rs1048990, rs2295826, rs2295827 and rs2348071 T1DM risk genotypes and expression levels of 14 genes related to the UPS and 42 T1DM-susceptible genes encoding proteins involved in innate and adaptive immunity, antiviral response, insulin signalling, glucose-energy metabolism and other pathways implicated in T1DM pathogenesis. Genotype-phenotype and genotype-genotype clusterings support genotyping results. Our results provide evidence on new T1DM-susceptible loci in the PSMA3, PSMA6 and PSMC6 proteasome genes and give a new insight into the T1DM pathogenesis.
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Affiliation(s)
- Tatjana Sjakste
- Genomics and Bioinformatics, Institute of Biology of the University of Latvia, Salaspils, Latvia.
| | - Natalia Paramonova
- Genomics and Bioinformatics, Institute of Biology of the University of Latvia, Salaspils, Latvia
| | - Kristine Osina
- Genomics and Bioinformatics, Institute of Biology of the University of Latvia, Salaspils, Latvia
| | - Kristine Dokane
- Genomics and Bioinformatics, Institute of Biology of the University of Latvia, Salaspils, Latvia
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28
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Liu L, Jiang L, Ding XD, Liu JF, Zhang Q. The regulation of glucose on milk fat synthesis is mediated by the ubiquitin-proteasome system in bovine mammary epithelial cells. Biochem Biophys Res Commun 2015; 465:59-63. [DOI: 10.1016/j.bbrc.2015.07.129] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Accepted: 07/25/2015] [Indexed: 10/23/2022]
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Wang C, Zou S, Cui Z, Guo P, Meng Q, Shi X, Gao Y, Yang G, Han Z. Zerumbone protects INS-1 rat pancreatic beta cells from high glucose-induced apoptosis through generation of reactive oxygen species. Biochem Biophys Res Commun 2015; 460:205-9. [DOI: 10.1016/j.bbrc.2015.03.009] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Accepted: 03/03/2015] [Indexed: 02/08/2023]
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Sahraoui A, Winzell MS, Gorman T, Smith DM, Skrtic S, Hoeyem M, Abadpour S, Johansson L, Korsgren O, Foss A, Scholz H. The effects of exendin-4 treatment on graft failure: an animal study using a novel re-vascularized minimal human islet transplant model. PLoS One 2015; 10:e0121204. [PMID: 25793295 PMCID: PMC4368803 DOI: 10.1371/journal.pone.0121204] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Accepted: 01/28/2015] [Indexed: 12/16/2022] Open
Abstract
Islet transplantation has become a viable clinical treatment, but is still compromised by long-term graft failure. Exendin-4, a glucagon-like peptide 1 receptor agonist, has in clinical studies been shown to improve insulin secretion in islet transplanted patients. However, little is known about the effect of exendin-4 on other metabolic parameters. We therefore aimed to determine what influence exendin-4 would have on revascularized minimal human islet grafts in a state of graft failure in terms of glucose metabolism, body weight, lipid levels and graft survival. Introducing the bilateral, subcapsular islet transplantation model, we first transplanted diabetic mice with a murine graft under the left kidney capsule sufficient to restore normoglycemia. After a convalescent period, we performed a second transplantation under the right kidney capsule with a minimal human islet graft and allowed for a second recovery. We then performed a left-sided nephrectomy, and immediately started treatment with exendin-4 with a low (20μg/kg/day) or high (200μg/kg/day) dose, or saline subcutaneously twice daily for 15 days. Blood was sampled, blood glucose and body weight monitored. The transplanted human islet grafts were collected at study end point and analyzed. We found that exendin-4 exerts its effect on failing human islet grafts in a bell-shaped dose-response curve. Both doses of exendin-4 equally and significantly reduced blood glucose. Glucagon-like peptide 1 (GLP-1), C-peptide and pro-insulin were conversely increased. In the course of the treatment, body weight and cholesterol levels were not affected. However, immunohistochemistry revealed an increase in beta cell nuclei count and reduced TUNEL staining only in the group treated with a low dose of exendin-4 compared to the high dose and control. Collectively, these results suggest that exendin-4 has a potential rescue effect on failing, revascularized human islets in terms of lowering blood glucose, maintaining beta cell numbers, and improving metabolic parameters during hyperglycemic stress.
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Affiliation(s)
- Afaf Sahraoui
- Institute for Surgical Research and Section for Transplantation Surgery, Oslo University Hospital, Oslo, Norway
- * E-mail:
| | | | - Tracy Gorman
- AstraZeneca, Alderley Park, Cheshire, United Kingdom
| | | | | | - Merete Hoeyem
- Institute for Surgical Research and Section for Transplantation Surgery, Oslo University Hospital, Oslo, Norway
| | - Shadab Abadpour
- Institute for Surgical Research and Section for Transplantation Surgery, Oslo University Hospital, Oslo, Norway
| | - Lars Johansson
- Department of Radiology, Oncology and Radiation Sciences, Uppsala University Hospital, Uppsala, Sweden
| | - Olle Korsgren
- Department of Immunology, Genetics and Pathology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Aksel Foss
- Institute for Surgical Research and Section for Transplantation Surgery, Oslo University Hospital, Oslo, Norway
- Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | - Hanne Scholz
- Institute for Surgical Research and Section for Transplantation Surgery, Oslo University Hospital, Oslo, Norway
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Litwak SA, Wali JA, Pappas EG, Saadi H, Stanley WJ, Varanasi LC, Kay TWH, Thomas HE, Gurzov EN. Lipotoxic Stress Induces Pancreatic β-Cell Apoptosis through Modulation of Bcl-2 Proteins by the Ubiquitin-Proteasome System. J Diabetes Res 2015; 2015:280615. [PMID: 26064977 PMCID: PMC4438180 DOI: 10.1155/2015/280615] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2015] [Revised: 04/17/2015] [Accepted: 04/20/2015] [Indexed: 01/09/2023] Open
Abstract
Pancreatic β-cell loss induced by saturated free fatty acids (FFAs) is believed to contribute to type 2 diabetes. Previous studies have shown induction of endoplasmic reticulum (ER) stress, increased ubiquitinated proteins, and deregulation of the Bcl-2 family in the pancreas of type 2 diabetic patients. However, the precise mechanism of β-cell death remains unknown. In the present study we demonstrate that the FFA palmitate blocks the ubiquitin-proteasome system (UPS) and causes apoptosis through induction of ER stress and deregulation of Bcl-2 proteins. We found that palmitate and the proteasome inhibitor MG132 induced ER stress in β-cells, resulting in decreased expression of the prosurvival proteins Bcl-2, Mcl-1, and Bcl-XL, and upregulation of the prodeath BH3-only protein PUMA. On the other hand, pharmacological activation of the UPS by sulforaphane ameliorated ER stress, upregulated prosurvival Bcl-2 proteins, and protected β-cells from FFA-induced cell death. Furthermore, transgenic overexpression of Bcl-2 protected islets from FFA-induced cell death in vitro and improved glucose-induced insulin secretion in vivo. Together our results suggest that targeting the UPS and Bcl-2 protein expression may be a valuable strategy to prevent β-cell demise in type 2 diabetes.
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Affiliation(s)
- Sara A. Litwak
- St Vincent's Institute of Medical Research, Melbourne, VIC 3065, Australia
| | - Jibran A. Wali
- St Vincent's Institute of Medical Research, Melbourne, VIC 3065, Australia
- Department of Medicine, St. Vincent's Hospital, The University of Melbourne, Melbourne, VIC 3065, Australia
| | - Evan G. Pappas
- St Vincent's Institute of Medical Research, Melbourne, VIC 3065, Australia
- Department of Medicine, St. Vincent's Hospital, The University of Melbourne, Melbourne, VIC 3065, Australia
| | - Hamdi Saadi
- St Vincent's Institute of Medical Research, Melbourne, VIC 3065, Australia
- Department of Medicine, St. Vincent's Hospital, The University of Melbourne, Melbourne, VIC 3065, Australia
| | - William J. Stanley
- St Vincent's Institute of Medical Research, Melbourne, VIC 3065, Australia
- Department of Medicine, St. Vincent's Hospital, The University of Melbourne, Melbourne, VIC 3065, Australia
| | - L. Chitra Varanasi
- St Vincent's Institute of Medical Research, Melbourne, VIC 3065, Australia
- Department of Medicine, St. Vincent's Hospital, The University of Melbourne, Melbourne, VIC 3065, Australia
| | - Thomas W. H. Kay
- St Vincent's Institute of Medical Research, Melbourne, VIC 3065, Australia
- Department of Medicine, St. Vincent's Hospital, The University of Melbourne, Melbourne, VIC 3065, Australia
| | - Helen E. Thomas
- St Vincent's Institute of Medical Research, Melbourne, VIC 3065, Australia
- Department of Medicine, St. Vincent's Hospital, The University of Melbourne, Melbourne, VIC 3065, Australia
| | - Esteban N. Gurzov
- St Vincent's Institute of Medical Research, Melbourne, VIC 3065, Australia
- Department of Medicine, St. Vincent's Hospital, The University of Melbourne, Melbourne, VIC 3065, Australia
- *Esteban N. Gurzov:
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Bhatnagar S, Soni MS, Wrighton LS, Hebert AS, Zhou AS, Paul PK, Gregg T, Rabaglia ME, Keller MP, Coon JJ, Attie AD. Phosphorylation and degradation of tomosyn-2 de-represses insulin secretion. J Biol Chem 2014; 289:25276-86. [PMID: 25002582 DOI: 10.1074/jbc.m114.575985] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The abundance and functional activity of proteins involved in the formation of the SNARE complex are tightly regulated for efficient exocytosis. Tomosyn proteins are negative regulators of exocytosis. Tomosyn causes an attenuation of insulin secretion by limiting the formation of the SNARE complex. We hypothesized that glucose-dependent stimulation of insulin secretion from β-cells must involve reversing the inhibitory action of tomosyn. Here, we show that glucose increases tomosyn protein turnover. Within 1 h of exposure to 15 mM glucose, ~50% of tomosyn was degraded. The degradation of tomosyn in response to high glucose was blocked by inhibitors of the proteasomal pathway. Using (32)P labeling and mass spectrometry, we showed that tomosyn-2 is phosphorylated in response to high glucose, phorbol esters, and analogs of cAMP, all key insulin secretagogues. We identified 11 phosphorylation sites in tomosyn-2. Site-directed mutagenesis was used to generate phosphomimetic (Ser → Asp) and loss-of-function (Ser → Ala) mutants. The Ser → Asp mutant had enhanced protein turnover compared with the Ser → Ala mutant and wild type tomosyn-2. Additionally, the Ser → Asp tomosyn-2 mutant was ineffective at inhibiting insulin secretion. Using a proteomic screen for tomosyn-2-binding proteins, we identified Hrd-1, an E3-ubiquitin ligase. We showed that tomosyn-2 ubiquitination is increased by Hrd-1, and knockdown of Hrd-1 by short hairpin RNA resulted in increased abundance in tomosyn-2 protein levels. Taken together, our results reveal a mechanism by which enhanced phosphorylation of a negative regulator of secretion, tomosyn-2, in response to insulin secretagogues targets it to degradation by the Hrd-1 E3-ubiquitin ligase.
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Affiliation(s)
| | | | | | - Alexander S Hebert
- Chemistry and Biomolecular Chemistry, University of Wisconsin, Madison, Wisconsin 53706
| | | | | | | | | | | | - Joshua J Coon
- Chemistry and Biomolecular Chemistry, University of Wisconsin, Madison, Wisconsin 53706
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Broca C, Varin E, Armanet M, Tourrel-Cuzin C, Bosco D, Dalle S, Wojtusciszyn A. Correction: proteasome dysfunction mediates high glucose-induced apoptosis in rodent Beta cells and human islets. PLoS One 2014; 9:e102652. [PMID: 25000098 PMCID: PMC4085027 DOI: 10.1371/journal.pone.0102652] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
[This corrects the article DOI: 10.1371/journal.pone.0092066.].
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