1
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Li J, Zhu J, Deng Y, Reck EC, Walker EM, Sidarala V, Hubers DL, Pasmooij MB, Shin CS, Bandesh K, Motakis E, Nargund S, Kursawe R, Basrur V, Nesvizhskii AI, Stitzel ML, Chan DC, Soleimanpour SA. LONP1 regulation of mitochondrial protein folding provides insight into beta cell failure in type 2 diabetes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.03.597215. [PMID: 38895283 PMCID: PMC11185607 DOI: 10.1101/2024.06.03.597215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/21/2024]
Abstract
Proteotoxicity is a contributor to the development of type 2 diabetes (T2D), but it is unknown whether protein misfolding in T2D is generalized or has special features. Here, we report a robust accumulation of misfolded proteins within the mitochondria of human pancreatic islets in T2D and elucidate its impact on β cell viability. Surprisingly, quantitative proteomics studies of protein aggregates reveal that human islets from donors with T2D have a signature more closely resembling mitochondrial rather than ER protein misfolding. The matrix protease LonP1 and its chaperone partner mtHSP70 were among the proteins enriched in protein aggregates. Deletion of LONP1 in mice yields mitochondrial protein misfolding and reduced respiratory function, ultimately leading to β cell apoptosis and hyperglycemia. Intriguingly, LONP1 gain of function ameliorates mitochondrial protein misfolding and restores human β cell survival following glucolipotoxicity via a protease-independent effect requiring LONP1-mtHSP70 chaperone activity. Thus, LONP1 promotes β cell survival and prevents hyperglycemia by facilitating mitochondrial protein folding. These observations may open novel insights into the nature of impaired proteostasis on β cell loss in the pathogenesis of T2D that could be considered as future therapeutic targets.
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2
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Wang Y, Zhai Y, Zhang M, Song C, Zhang Y, Zhang G. Escaping from CRISPR-Cas-mediated knockout: the facts, mechanisms, and applications. Cell Mol Biol Lett 2024; 29:48. [PMID: 38589794 PMCID: PMC11003099 DOI: 10.1186/s11658-024-00565-x] [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: 10/01/2023] [Accepted: 03/21/2024] [Indexed: 04/10/2024] Open
Abstract
Clustered regularly interspaced short palindromic repeats and associated Cas protein (CRISPR-Cas), a powerful genome editing tool, has revolutionized gene function investigation and exhibits huge potential for clinical applications. CRISPR-Cas-mediated gene knockout has already become a routine method in research laboratories. However, in the last few years, accumulating evidences have demonstrated that genes knocked out by CRISPR-Cas may not be truly silenced. Functional residual proteins could be generated in such knockout organisms to compensate the putative loss of function, termed herein knockout escaping. In line with this, several CRISPR-Cas-mediated knockout screenings have discovered much less abnormal phenotypes than expected. How does knockout escaping happen and how often does it happen have not been systematically reviewed yet. Without knowing this, knockout results could easily be misinterpreted. In this review, we summarize these evidences and propose two main mechanisms allowing knockout escaping. To avoid the confusion caused by knockout escaping, several strategies are discussed as well as their advantages and disadvantages. On the other hand, knockout escaping also provides convenient tools for studying essential genes and treating monogenic disorders such as Duchenne muscular dystrophy, which are discussed in the end.
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Affiliation(s)
- Ying Wang
- The Cancer Institute, The Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, China
- School of Public Health, Qingdao University, Qingdao, China
| | - Yujing Zhai
- The Cancer Institute, The Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, China
- School of Public Health, Qingdao University, Qingdao, China
| | - Mingzhe Zhang
- The Cancer Institute, The Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, China
| | - Chunlin Song
- The Cancer Institute, The Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, China
| | - Yuqing Zhang
- The Cancer Institute, The Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, China
| | - Gang Zhang
- The Cancer Institute, The Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, China.
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3
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Ghiasi SM, Marchetti P, Piemonti L, Nielsen JH, Porse BT, Mandrup-Poulsen T, Rutter GA. Proinflammatory cytokines suppress nonsense-mediated RNA decay to impair regulated transcript isoform processing in pancreatic β cells. Front Endocrinol (Lausanne) 2024; 15:1359147. [PMID: 38586449 PMCID: PMC10995974 DOI: 10.3389/fendo.2024.1359147] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Accepted: 03/05/2024] [Indexed: 04/09/2024] Open
Abstract
Introduction Proinflammatory cytokines are implicated in pancreatic ß cell failure in type 1 and type 2 diabetes and are known to stimulate alternative RNA splicing and the expression of nonsense-mediated RNA decay (NMD) components. Here, we investigate whether cytokines regulate NMD activity and identify transcript isoforms targeted in ß cells. Methods A luciferase-based NMD reporter transiently expressed in rat INS1(832/13), human-derived EndoC-ßH3, or dispersed human islet cells is used to examine the effect of proinflammatory cytokines (Cyt) on NMD activity. The gain- or loss-of-function of two key NMD components, UPF3B and UPF2, is used to reveal the effect of cytokines on cell viability and function. RNA-sequencing and siRNA-mediated silencing are deployed using standard techniques. Results Cyt attenuate NMD activity in insulin-producing cell lines and primary human ß cells. These effects are found to involve ER stress and are associated with the downregulation of UPF3B. Increases or decreases in NMD activity achieved by UPF3B overexpression (OE) or UPF2 silencing raise or lower Cyt-induced cell death, respectively, in EndoC-ßH3 cells and are associated with decreased or increased insulin content, respectively. No effects of these manipulations are observed on glucose-stimulated insulin secretion. Transcriptomic analysis reveals that Cyt increases alternative splicing (AS)-induced exon skipping in the transcript isoforms, and this is potentiated by UPF2 silencing. Gene enrichment analysis identifies transcripts regulated by UPF2 silencing whose proteins are localized and/or functional in the extracellular matrix (ECM), including the serine protease inhibitor SERPINA1/α-1-antitrypsin, whose silencing sensitizes ß-cells to Cyt cytotoxicity. Cytokines suppress NMD activity via UPR signaling, potentially serving as a protective response against Cyt-induced NMD component expression. Conclusion Our findings highlight the central importance of RNA turnover in ß cell responses to inflammatory stress.
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Affiliation(s)
- Seyed M. Ghiasi
- Section of Cell Biology and Functional Genomics, Division of Diabetes, Endocrinology and Metabolism, Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, London, United Kingdom
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
- Development and Aging Program, and Human Genetics Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, United States
| | - Piero Marchetti
- Department of Clinical and Experimental Medicine, Islet Cell Laboratory, University of Pisa, Pisa, Italy
| | - Lorenzo Piemonti
- Diabetes Research Institute, Istituto Di Ricovero e Cura a Carattere Scientifico (IRCCS) Ospedale San Raffaele, Milano, Italy
| | - Jens H. Nielsen
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Bo T. Porse
- Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Copenhagen, Denmark
- The Finsen Laboratory, Rigshospitalet, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
- Danish Stem Cell Center (DanStem) Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | - Guy A. Rutter
- Section of Cell Biology and Functional Genomics, Division of Diabetes, Endocrinology and Metabolism, Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, London, United Kingdom
- Centre Hospitalier de l'Université de Montréal (CHUM) Research Centre (CRCHUM) and Faculty of Medicine, University of Montreal, Montreal, QC, Canada
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
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4
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Ghiasi SM, Marchetti P, Piemonti L, Nielsen JH, Porse BT, Mandrup-Poulsen T, Rutter GA. Proinflammatory Cytokines Suppress Nonsense-Mediated RNA Decay to Impair Regulated Transcript Isoform Processing in Pancreatic β-Cells. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.12.20.572623. [PMID: 38187722 PMCID: PMC10769295 DOI: 10.1101/2023.12.20.572623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
Proinflammatory cytokines are implicated in pancreatic β-cell failure in type 1 and type 2 diabetes and are known to stimulate alternative RNA splicing and the expression of Nonsense-Mediated RNA Decay (NMD) components. Here, we investigate whether cytokines regulate NMD activity and identify transcript isoforms targeted in β-cells. A luciferase-based NMD reporter transiently expressed in rat INS1(832/13), human-derived EndoC-βH3 or dispersed human islet cells is used to examine the effect of proinflammatory cytokines (Cyt) on NMD activity. Gain- or loss-of function of two key NMD components UPF3B and UPF2 is used to reveal the effect of cytokines on cell viability and function. RNA-sequencing and siRNA-mediated silencing are deployed using standard techniques. Cyt attenuate NMD activity in insulin-producing cell lines and primary human β-cells. These effects are found to involve ER stress and are associated with downregulation of UPF3B. Increases or decreases in NMD activity achieved by UPF3B overexpression (OE) or UPF2 silencing, raises or lowers Cyt-induced cell death, respectively, in EndoC-βH3 cells, and are associated with decreased or increased insulin content, respectively. No effects of these manipulations are observed on glucose-stimulated insulin secretion. Transcriptomic analysis reveals that Cyt increase alternative splicing (AS)-induced exon skipping in the transcript isoforms, and this is potentiated by UPF2 silencing. Gene enrichment analysis identifies transcripts regulated by UPF2 silencing whose proteins are localized and/or functional in extracellular matrix (ECM) including the serine protease inhibitor SERPINA1/α-1-antitrypsin, whose silencing sensitises β-cells to Cyt cytotoxicity. Cytokines suppress NMD activity via UPR signalling, potentially serving as a protective response against Cyt-induced NMD component expression. Our findings highlight the central importance of RNA turnover in β-cell responses to inflammatory stress.
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Affiliation(s)
- Seyed. M. Ghiasi
- Section of Cell Biology and Functional Genomics, Division of Diabetes, Endocrinology and Metabolism, Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London Du Cane Road, London W12 0NN, United Kingdom
- Department of Biomedical Sciences, University of Copenhagen, 3 Blegdamsvej, 2200 Copenhagen N, Denmark
- Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - Piero Marchetti
- Department of Clinical and Experimental Medicine, Islet Cell Laboratory, University of Pisa, 56126, Pisa, Italy
| | - Lorenzo Piemonti
- Diabetes Research Institute, IRCCS Ospedale San Raffaele, Milano, Italy
| | - Jens H. Nielsen
- Department of Biomedical Sciences, University of Copenhagen, 3 Blegdamsvej, 2200 Copenhagen N, Denmark
| | - Bo T. Porse
- Biotech Research and Innovation Centre (BRIC), University of Copenhagen, 3 Blegdamsvej, 2200 Copenhagen N, Denmark
- The Finsen Laboratory, Rigshospitalet, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
- Danish Stem Cell Center (DanStem) Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Thomas Mandrup-Poulsen
- Department of Biomedical Sciences, University of Copenhagen, 3 Blegdamsvej, 2200 Copenhagen N, Denmark
| | - Guy A. Rutter
- Section of Cell Biology and Functional Genomics, Division of Diabetes, Endocrinology and Metabolism, Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London Du Cane Road, London W12 0NN, United Kingdom
- CHUM Research Centre (CRCHUM) and Faculty of Medicine, University of Montreal, 900 Rue St. Denis, Montreal, QC, Canada
- Lee Kong Chian School of Medicine, Nanyang Technological University, 637553, Singapore
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5
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Tao Y, Zhang Q, Wang H, Yang X, Mu H. Alternative splicing and related RNA binding proteins in human health and disease. Signal Transduct Target Ther 2024; 9:26. [PMID: 38302461 PMCID: PMC10835012 DOI: 10.1038/s41392-024-01734-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2023] [Revised: 12/18/2023] [Accepted: 12/27/2023] [Indexed: 02/03/2024] Open
Abstract
Alternative splicing (AS) serves as a pivotal mechanism in transcriptional regulation, engendering transcript diversity, and modifications in protein structure and functionality. Across varying tissues, developmental stages, or under specific conditions, AS gives rise to distinct splice isoforms. This implies that these isoforms possess unique temporal and spatial roles, thereby associating AS with standard biological activities and diseases. Among these, AS-related RNA-binding proteins (RBPs) play an instrumental role in regulating alternative splicing events. Under physiological conditions, the diversity of proteins mediated by AS influences the structure, function, interaction, and localization of proteins, thereby participating in the differentiation and development of an array of tissues and organs. Under pathological conditions, alterations in AS are linked with various diseases, particularly cancer. These changes can lead to modifications in gene splicing patterns, culminating in changes or loss of protein functionality. For instance, in cancer, abnormalities in AS and RBPs may result in aberrant expression of cancer-associated genes, thereby promoting the onset and progression of tumors. AS and RBPs are also associated with numerous neurodegenerative diseases and autoimmune diseases. Consequently, the study of AS across different tissues holds significant value. This review provides a detailed account of the recent advancements in the study of alternative splicing and AS-related RNA-binding proteins in tissue development and diseases, which aids in deepening the understanding of gene expression complexity and offers new insights and methodologies for precision medicine.
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Affiliation(s)
- Yining Tao
- Department of Orthopedics, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, 200000, Shanghai, China
- Shanghai Bone Tumor Institution, 200000, Shanghai, China
| | - Qi Zhang
- Department of Biochemistry and Molecular Cell Biology, Shanghai Key Laboratory for Tumor Microenvironment and Inflammation, Shanghai Jiao Tong University School of Medicine, 200000, Shanghai, China
| | - Haoyu Wang
- Department of Orthopedics, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, 200000, Shanghai, China
- Shanghai Bone Tumor Institution, 200000, Shanghai, China
| | - Xiyu Yang
- Department of Orthopedics, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, 200000, Shanghai, China
- Shanghai Bone Tumor Institution, 200000, Shanghai, China
| | - Haoran Mu
- Department of Orthopedics, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, 200000, Shanghai, China.
- Shanghai Bone Tumor Institution, 200000, Shanghai, China.
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6
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Piron A, Szymczak F, Papadopoulou T, Alvelos MI, Defrance M, Lenaerts T, Eizirik DL, Cnop M. RedRibbon: A new rank-rank hypergeometric overlap for gene and transcript expression signatures. Life Sci Alliance 2024; 7:e202302203. [PMID: 38081640 PMCID: PMC10709657 DOI: 10.26508/lsa.202302203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 11/28/2023] [Accepted: 11/29/2023] [Indexed: 12/18/2023] Open
Abstract
High-throughput omics technologies have generated a wealth of large protein, gene, and transcript datasets that have exacerbated the need for new methods to analyse and compare big datasets. Rank-rank hypergeometric overlap is an important threshold-free method to combine and visualize two ranked lists of P-values or fold-changes, usually from differential gene expression analyses. Here, we introduce a new rank-rank hypergeometric overlap-based method aimed at gene level and alternative splicing analyses at transcript or exon level, hitherto unreachable as transcript numbers are an order of magnitude larger than gene numbers. We tested the tool on synthetic and real datasets at gene and transcript levels to detect correlation and anticorrelation patterns and found it to be fast and accurate, even on very large datasets thanks to an evolutionary algorithm-based minimal P-value search. The tool comes with a ready-to-use permutation scheme allowing the computation of adjusted P-values at low time cost. The package compatibility mode is a drop-in replacement to previous packages. RedRibbon holds the promise to accurately extricate detailed information from large comparative analyses.
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Affiliation(s)
- Anthony Piron
- https://ror.org/01r9htc13 ULB Center for Diabetes Research, Medical Faculty, Université Libre de Bruxelles, Brussels, Belgium
- Interuniversity Institute of Bioinformatics in Brussels (IB2), Brussels, Belgium
- https://ror.org/01r9htc13 Machine Learning Group, Université Libre de Bruxelles, Brussels, Belgium
| | - Florian Szymczak
- https://ror.org/01r9htc13 ULB Center for Diabetes Research, Medical Faculty, Université Libre de Bruxelles, Brussels, Belgium
- Interuniversity Institute of Bioinformatics in Brussels (IB2), Brussels, Belgium
| | - Theodora Papadopoulou
- https://ror.org/01r9htc13 ULB Center for Diabetes Research, Medical Faculty, Université Libre de Bruxelles, Brussels, Belgium
- Interuniversity Institute of Bioinformatics in Brussels (IB2), Brussels, Belgium
| | - Maria Inês Alvelos
- https://ror.org/01r9htc13 ULB Center for Diabetes Research, Medical Faculty, Université Libre de Bruxelles, Brussels, Belgium
| | - Matthieu Defrance
- Interuniversity Institute of Bioinformatics in Brussels (IB2), Brussels, Belgium
- https://ror.org/01r9htc13 Machine Learning Group, Université Libre de Bruxelles, Brussels, Belgium
| | - Tom Lenaerts
- Interuniversity Institute of Bioinformatics in Brussels (IB2), Brussels, Belgium
- https://ror.org/01r9htc13 Machine Learning Group, Université Libre de Bruxelles, Brussels, Belgium
- Artificial Intelligence Lab, Vrije Universiteit Brussel, Brussels, Belgium
| | - Décio L Eizirik
- https://ror.org/01r9htc13 ULB Center for Diabetes Research, Medical Faculty, Université Libre de Bruxelles, Brussels, Belgium
| | - Miriam Cnop
- https://ror.org/01r9htc13 ULB Center for Diabetes Research, Medical Faculty, Université Libre de Bruxelles, Brussels, Belgium
- https://ror.org/01r9htc13 Division of Endocrinology, Erasmus Hospital, Université Libre de Bruxelles, Brussels, Belgium
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7
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Xiong L, Gong Y, Liu H, Huang L, Zeng Z, Zheng X, Li W, Liang Z, Kang L. circGlis3 promotes β-cell dysfunction by binding to heterogeneous nuclear ribonucleoprotein F and encoding Glis3-348aa protein. iScience 2024; 27:108680. [PMID: 38226164 PMCID: PMC10788204 DOI: 10.1016/j.isci.2023.108680] [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: 04/17/2023] [Revised: 10/12/2023] [Accepted: 12/05/2023] [Indexed: 01/17/2024] Open
Abstract
Circular RNAs (circRNAs) are crucial regulators of β-cell function and are involved in lipotoxicity-induced β-cell damage in type 2 diabetes mellitus (T2DM). We previously identified that circGlis3, a circRNA derived from exon 4 of the diabetes susceptibility gene Glis3, was upregulated in lipotoxic β cells. However, the functional role and molecular mechanism of circGlis3 in β cells remain largely unknown. Here, we revealed that the splicing factor CUGBP Elav-Like Family Member 1 (CELF1) facilitated the biogenesis of circGlis3. Moreover, we established a transgenic mouse model and confirmed that the overexpression of circGlis3 impaired β-cell function. Mechanistically, circGlis3 bound to heterogeneous nuclear ribonucleoprotein F (hnRNPF) and blocked its nuclear translocation, thereby reducing Sirt1 levels. Additionally, circGlis3 encoded a 348aa protein that interacted with GLIS3 and inhibited its transcriptional activity. Our data uncover a critical role of circGlis3 in β-cell dysfunction, suggesting that circGlis3 may be a potential therapeutic target for T2DM.
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Affiliation(s)
- Li Xiong
- Department of Colorectal Surgery, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
- Department of General Surgery, Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor Diseases, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Yingying Gong
- Department of Geriatrics, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Huashan Liu
- Department of Colorectal Surgery, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
- Department of General Surgery, Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor Diseases, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Liang Huang
- Department of Colorectal Surgery, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
- Department of General Surgery, Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor Diseases, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Ziwei Zeng
- Department of Colorectal Surgery, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
- Department of General Surgery, Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor Diseases, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Xiaobin Zheng
- Department of Colorectal Surgery, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
- Department of General Surgery, Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor Diseases, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Wenxin Li
- Department of Colorectal Surgery, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
- Department of General Surgery, Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor Diseases, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Zhenxing Liang
- Department of Colorectal Surgery, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
- Department of General Surgery, Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor Diseases, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Liang Kang
- Department of Colorectal Surgery, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
- Department of General Surgery, Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor Diseases, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
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8
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Puri S, Maachi H, Nair G, Russ HA, Chen R, Pulimeno P, Cutts Z, Ntranos V, Hebrok M. Sox9 regulates alternative splicing and pancreatic beta cell function. Nat Commun 2024; 15:588. [PMID: 38238288 PMCID: PMC10796970 DOI: 10.1038/s41467-023-44384-8] [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: 06/01/2021] [Accepted: 12/12/2023] [Indexed: 01/22/2024] Open
Abstract
Despite significant research, mechanisms underlying the failure of islet beta cells that result in type 2 diabetes (T2D) are still under investigation. Here, we report that Sox9, a transcriptional regulator of pancreas development, also functions in mature beta cells. Our results show that Sox9-depleted rodent beta cells have defective insulin secretion, and aging animals develop glucose intolerance, mimicking the progressive degeneration observed in T2D. Using genome editing in human stem cells, we show that beta cells lacking SOX9 have stunted first-phase insulin secretion. In human and rodent cells, loss of Sox9 disrupts alternative splicing and triggers accumulation of non-functional isoforms of genes with key roles in beta cell function. Sox9 depletion reduces expression of protein-coding splice variants of the serine-rich splicing factor arginine SRSF5, a major splicing enhancer that regulates alternative splicing. Our data highlight the role of SOX9 as a regulator of alternative splicing in mature beta cell function.
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Affiliation(s)
- Sapna Puri
- Diabetes Center, Department of Medicine, University of California, San Francisco, CA, USA
- Minutia Inc., Oakland, CA, USA
| | - Hasna Maachi
- Diabetes Center, Department of Medicine, University of California, San Francisco, CA, USA
- Center for Organoid Systems, Klinikum Rechts der Isar (MRI) and Technical University Munich, 85748, Garching, Germany
- Institute for Diabetes Organoid Technology, Helmholtz Munich, Helmholtz Diabetes Center, Ingolstädter Landstraße 1, 85764, Neuherberg, Germany
- Munich Institute of Biomedical Engineering (MIBE), Technical University Munich, Munich, Germany
- German Center for Diabetes Research (DZD), Ingolstaedter Landstrasse 1, 85764, Neuherberg, Germany
| | - Gopika Nair
- Diabetes Center, Department of Medicine, University of California, San Francisco, CA, USA
- Eli Lilly, Indianapolis, IN, USA
| | - Holger A Russ
- Diabetes Center, Department of Medicine, University of California, San Francisco, CA, USA
- Diabetes Institute, University of Florida, Gainesville, FL, USA
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL, USA
| | - Richard Chen
- Diabetes Center, Department of Medicine, University of California, San Francisco, CA, USA
| | - Pamela Pulimeno
- Diabetes Center, Department of Medicine, University of California, San Francisco, CA, USA
| | - Zachary Cutts
- Graduate Program in Bioinformatics, University of California, San Francisco, CA, USA
| | - Vasilis Ntranos
- Diabetes Center, Department of Medicine, University of California, San Francisco, CA, USA
| | - Matthias Hebrok
- Diabetes Center, Department of Medicine, University of California, San Francisco, CA, USA.
- Center for Organoid Systems, Klinikum Rechts der Isar (MRI) and Technical University Munich, 85748, Garching, Germany.
- Institute for Diabetes Organoid Technology, Helmholtz Munich, Helmholtz Diabetes Center, Ingolstädter Landstraße 1, 85764, Neuherberg, Germany.
- Munich Institute of Biomedical Engineering (MIBE), Technical University Munich, Munich, Germany.
- German Center for Diabetes Research (DZD), Ingolstaedter Landstrasse 1, 85764, Neuherberg, Germany.
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9
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Atkinson MA, Mirmira RG. The pathogenic "symphony" in type 1 diabetes: A disorder of the immune system, β cells, and exocrine pancreas. Cell Metab 2023; 35:1500-1518. [PMID: 37478842 PMCID: PMC10529265 DOI: 10.1016/j.cmet.2023.06.018] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 06/22/2023] [Accepted: 06/28/2023] [Indexed: 07/23/2023]
Abstract
Type 1 diabetes (T1D) is widely considered to result from the autoimmune destruction of insulin-producing β cells. This concept has been a central tenet for decades of attempts seeking to decipher the disorder's pathogenesis and prevent/reverse the disease. Recently, this and many other disease-related notions have come under increasing question, particularly given knowledge gained from analyses of human T1D pancreas. Perhaps most crucial are findings suggesting that a collective of cellular constituents-immune, endocrine, and exocrine in origin-mechanistically coalesce to facilitate T1D. This review considers these emerging concepts, from basic science to clinical research, and identifies several key remaining knowledge voids.
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Affiliation(s)
- Mark A Atkinson
- Department of Pathology, Immunology, and Laboratory Medicine, College of Medicine, University of Florida, Gainesville, FL 32610, USA.
| | - Raghavendra G Mirmira
- Departments of Medicine and Pediatrics, The University of Chicago, Chicago, IL 60637, USA
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10
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Lodde V, Floris M, Zoroddu E, Zarbo IR, Idda ML. RNA-binding proteins in autoimmunity: From genetics to molecular biology. WILEY INTERDISCIPLINARY REVIEWS. RNA 2023; 14:e1772. [PMID: 36658783 DOI: 10.1002/wrna.1772] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 11/18/2022] [Accepted: 12/05/2022] [Indexed: 01/21/2023]
Abstract
Autoimmune diseases (ADs) are chronic pathologies generated by the loss of immune tolerance to the body's own cells and tissues. There is growing recognition that RNA-binding proteins (RBPs) critically govern immunity in healthy and pathological conditions by modulating gene expression post-transcriptionally at all levels: nuclear mRNA splicing and modification, export to the cytoplasm, as well as cytoplasmic mRNA transport, storage, editing, stability, and translation. Despite enormous efforts to identify new therapies for ADs, definitive solutions are not yet available in many instances. Recognizing that many ADs have a strong genetic component, we have explored connections between the molecular biology and the genetics of RBPs in ADs. Here, we review the genetics and molecular biology of RBPs in four major ADs, multiple sclerosis (MS), type 1 diabetes mellitus (T1D), systemic lupus erythematosus (SLE), and rheumatoid arthritis (RA). We anticipate that gaining insights into the genetics and biology of ADs can facilitate the discovery of new therapies. This article is categorized under: RNA in Disease and Development > RNA in Disease.
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Affiliation(s)
- Valeria Lodde
- Department of Biomedical Sciences, University of Sassari, Sassari, Italy
| | - Matteo Floris
- Department of Biomedical Sciences, University of Sassari, Sassari, Italy
| | - Enrico Zoroddu
- Department of Biomedical Sciences, University of Sassari, Sassari, Italy
| | - Ignazio Roberto Zarbo
- Department of Medical, Surgical and Experimental Sciences, University of Sassari - Neurology Unit Azienza Ospedaliera Universitaria (AOU), Sassari, Italy
| | - Maria Laura Idda
- Institute for Genetic and Biomedical Research - National Research Council (IRGB-CNR), Sassari, Italy
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11
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Szymczak F, Alvelos MI, Marín-Cañas S, Castela Â, Demine S, Colli ML, Op de Beeck A, Thomaidou S, Marselli L, Zaldumbide A, Marchetti P, Eizirik DL. Transcription and splicing regulation by NLRC5 shape the interferon response in human pancreatic β cells. SCIENCE ADVANCES 2022; 8:eabn5732. [PMID: 36103539 PMCID: PMC9473574 DOI: 10.1126/sciadv.abn5732] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 07/27/2022] [Indexed: 06/15/2023]
Abstract
IFNα is a key regulator of the dialogue between pancreatic β cells and the immune system in early type 1 diabetes (T1D). IFNα up-regulates HLA class I expression in human β cells, fostering autoantigen presentation to the immune system. We observed by bulk and single-cell RNA sequencing that exposure of human induced pluripotent-derived islet-like cells to IFNα induces expression of HLA class I and of other genes involved in antigen presentation, including the transcriptional activator NLRC5. We next evaluated the global role of NLRC5 in human insulin-producing EndoC-βH1 and human islet cells by RNA sequencing and targeted gene/protein determination. NLRC5 regulates expression of HLA class I, antigen presentation-related genes, and chemokines. NLRC5 also mediates the effects of IFNα on alternative splicing, a generator of β cell neoantigens, suggesting that it is a central player of the effects of IFNα on β cells that contribute to trigger and amplify autoimmunity in T1D.
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Affiliation(s)
- Florian Szymczak
- ULB Center for Diabetes Research, Medical Faculty, Université Libre De Bruxelles (ULB), Brussels, Belgium
- Interuniversity Institute of Bioinformatics in Brussels, Université Libre de Bruxelles-Vrije Universiteit Brussel, Brussels, Belgium
| | - Maria Inês Alvelos
- ULB Center for Diabetes Research, Medical Faculty, Université Libre De Bruxelles (ULB), Brussels, Belgium
| | - Sandra Marín-Cañas
- ULB Center for Diabetes Research, Medical Faculty, Université Libre De Bruxelles (ULB), Brussels, Belgium
| | - Ângela Castela
- ULB Center for Diabetes Research, Medical Faculty, Université Libre De Bruxelles (ULB), Brussels, Belgium
| | - Stéphane Demine
- Indiana Biosciences Research Institute, Indianapolis, IN, USA
| | - Maikel Luis Colli
- ULB Center for Diabetes Research, Medical Faculty, Université Libre De Bruxelles (ULB), Brussels, Belgium
| | - Anne Op de Beeck
- ULB Center for Diabetes Research, Medical Faculty, Université Libre De Bruxelles (ULB), Brussels, Belgium
| | - Sofia Thomaidou
- Department of Cell and Chemical Biology, Leiden University Medical Center, Leiden, Netherlands
| | - Lorella Marselli
- Department of Clinical and Experimental Medicine, Islet Cell Laboratory, University of Pisa, Pisa, Italy
| | - Arnaud Zaldumbide
- Department of Cell and Chemical Biology, Leiden University Medical Center, Leiden, Netherlands
| | - Piero Marchetti
- Department of Clinical and Experimental Medicine, Islet Cell Laboratory, University of Pisa, Pisa, Italy
| | - Décio L. Eizirik
- ULB Center for Diabetes Research, Medical Faculty, Université Libre De Bruxelles (ULB), Brussels, Belgium
- Welbio, Medical Faculty, Université Libre De Bruxelles (ULB), Brussels, Belgium
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12
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Chen X, Wu J, Li Z, Han J, Xia P, Shen Y, Ma J, Liu X, Zhang J, Yu P. Advances in The Study of RNA-binding Proteins in Diabetic Complications. Mol Metab 2022; 62:101515. [PMID: 35597446 PMCID: PMC9168169 DOI: 10.1016/j.molmet.2022.101515] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 04/21/2022] [Accepted: 05/12/2022] [Indexed: 12/18/2022] Open
Abstract
Background It has been reported that diabetes mellitus affects 435 million people globally as a primary health care problem. Despite many therapies available, many diabetes remains uncontrolled, giving rise to irreversible diabetic complications that pose significant risks to patients’ wellbeing and survival. Scope of Review In recent years, as much effort is put into elucidating the posttranscriptional gene regulation network of diabetes and diabetic complications; RNA binding proteins (RBPs) are found to be vital. RBPs regulate gene expression through various post-transcriptional mechanisms, including alternative splicing, RNA export, messenger RNA translation, RNA degradation, and RNA stabilization. Major Conclusions Here, we summarized recent studies on the roles and mechanisms of RBPs in mediating abnormal gene expression in diabetes and its complications. Moreover, we discussed the potential and theoretical basis of RBPs to treat diabetes and its complications. • Mechanisms of action of RBPs involved in diabetic complications are summarized and elucidated. • We discuss the theoretical basis and potential of RBPs for the treatment of diabetes and its complications. • We summarize the possible effective drugs for diabetes based on RBPs promoting the development of future therapeutic drugs.
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Affiliation(s)
- Xinyue Chen
- The Second Clinical Medical College of Nanchang University, the Second Affiliated Hospital of Nanchang University, Nanchang, China
| | - Jiaqiang Wu
- The Second Clinical Medical College of Nanchang University, the Second Affiliated Hospital of Nanchang University, Nanchang, China
| | - Zhangwang Li
- The Second Clinical Medical College of Nanchang University, the Second Affiliated Hospital of Nanchang University, Nanchang, China
| | - Jiashu Han
- Department of Thoracic Surgery, Peking Union Medical College Hospital, Beijing 100730, China
| | - Panpan Xia
- Department of Metabolism and Endocrinology, the Second Affiliated Hospital of Nanchang University, Nanchang, China
| | - Yunfeng Shen
- Department of Metabolism and Endocrinology, the Second Affiliated Hospital of Nanchang University, Nanchang, China
| | - Jianyong Ma
- Department of Pharmacology and Systems Physiology, University of Cincinnati College of Medicine, USA
| | - Xiao Liu
- Department of Cardiology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - Jing Zhang
- The Second Clinical Medical College of Nanchang University, the Second Affiliated Hospital of Nanchang University, Nanchang, China; Department of Anesthesiology, The Second Affiliated Hospital of Nanchang University, Jiangxi, Nanchang 330006, China.
| | - Peng Yu
- The Second Clinical Medical College of Nanchang University, the Second Affiliated Hospital of Nanchang University, Nanchang, China; Department of Metabolism and Endocrinology, the Second Affiliated Hospital of Nanchang University, Nanchang, China.
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13
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He J, Shu Y, Dai Y, Gao Y, Liu S, Wang W, Jiang H, Zhang H, Hong P, Wu H. Microcystin-leucine arginine exposure induced intestinal lipid accumulation and MC-LR efflux disorder in Lithobates catesbeianus tadpoles. Toxicology 2022; 465:153058. [PMID: 34863901 DOI: 10.1016/j.tox.2021.153058] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 11/05/2021] [Accepted: 11/30/2021] [Indexed: 12/18/2022]
Abstract
Few studies exist on the toxic effects of chronic exposure to microcystins (MCs) on amphibian intestines, and the toxicity mechanisms are unclear. Here, we evaluated the impact of subchronic exposure (30 days) to environmentally realistic microcystin-leucine arginine (MC-LR) concentrations (0 μg/L, 0.5 μg/L and 2 μg/L) on tadpole (Lithobates catesbeianus) intestines by analyzing the histopathological and subcellular microstructural damage, the antioxidative and oxidative enzyme activities, and the transcriptome levels. Histopathological results showed severe damage accompanied by inflammation to the intestinal tissues as the MC-LR exposure concentration increased from 0.5 μg/L to 2 μg/L. RNA-sequencing analysis identified 634 and 1,147 differentially expressed genes (DEGs) after exposure to 0.5 μg/L and 2 μg/L MC-LR, respectively, compared with those of the control group (0 μg/L). Biosynthesis of unsaturated fatty acids and the peroxisome proliferator-activated receptor (PPAR) signaling pathway were upregulated in the intestinal tissues of the exposed groups, with many lipid droplets being observed on transmission electron microscopy, implying that MC-LR may induce lipid accumulation in frog intestines. Moreover, 2 μg/L of MC-LR exposure inhibited the xenobiotic and toxicant biodegradation related to detoxification, implying that the tadpoles' intestinal detoxification ability was weakened after exposure to 2 μg/L MC-LR, which may aggravate intestinal toxicity. Lipid accumulation and toxin efflux disorder may be caused by MC-LR-induced endoplasmic reticular stress. This study presents new evidence that MC-LR harms amphibians by impairing intestinal lipid metabolism and toxin efflux, providing a theoretical basis for evaluating the health risks of MC-LR to amphibians.
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Affiliation(s)
- Jun He
- Collaborative Innovation Center of Recovery and Reconstruction of Degraded Ecosystem in Wanjiang Basin Co-founded by Anhui Province and Ministry of Education, School of Ecology and Environment, Anhui Normal University, Wuhu 241002, Anhui Province, China.
| | - Yilin Shu
- Collaborative Innovation Center of Recovery and Reconstruction of Degraded Ecosystem in Wanjiang Basin Co-founded by Anhui Province and Ministry of Education, School of Ecology and Environment, Anhui Normal University, Wuhu 241002, Anhui Province, China.
| | - Yue Dai
- Collaborative Innovation Center of Recovery and Reconstruction of Degraded Ecosystem in Wanjiang Basin Co-founded by Anhui Province and Ministry of Education, School of Ecology and Environment, Anhui Normal University, Wuhu 241002, Anhui Province, China.
| | - Yuxin Gao
- Collaborative Innovation Center of Recovery and Reconstruction of Degraded Ecosystem in Wanjiang Basin Co-founded by Anhui Province and Ministry of Education, School of Ecology and Environment, Anhui Normal University, Wuhu 241002, Anhui Province, China.
| | - Shuyi Liu
- Collaborative Innovation Center of Recovery and Reconstruction of Degraded Ecosystem in Wanjiang Basin Co-founded by Anhui Province and Ministry of Education, School of Ecology and Environment, Anhui Normal University, Wuhu 241002, Anhui Province, China.
| | - Wenchao Wang
- Collaborative Innovation Center of Recovery and Reconstruction of Degraded Ecosystem in Wanjiang Basin Co-founded by Anhui Province and Ministry of Education, School of Ecology and Environment, Anhui Normal University, Wuhu 241002, Anhui Province, China.
| | - Huiling Jiang
- Collaborative Innovation Center of Recovery and Reconstruction of Degraded Ecosystem in Wanjiang Basin Co-founded by Anhui Province and Ministry of Education, School of Ecology and Environment, Anhui Normal University, Wuhu 241002, Anhui Province, China.
| | - Huijuan Zhang
- Collaborative Innovation Center of Recovery and Reconstruction of Degraded Ecosystem in Wanjiang Basin Co-founded by Anhui Province and Ministry of Education, School of Ecology and Environment, Anhui Normal University, Wuhu 241002, Anhui Province, China.
| | - Pei Hong
- Collaborative Innovation Center of Recovery and Reconstruction of Degraded Ecosystem in Wanjiang Basin Co-founded by Anhui Province and Ministry of Education, School of Ecology and Environment, Anhui Normal University, Wuhu 241002, Anhui Province, China; State Key Laboratory of Marine Pollution, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, China.
| | - Hailong Wu
- Collaborative Innovation Center of Recovery and Reconstruction of Degraded Ecosystem in Wanjiang Basin Co-founded by Anhui Province and Ministry of Education, School of Ecology and Environment, Anhui Normal University, Wuhu 241002, Anhui Province, China.
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14
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Luce S, Guinoiseau S, Gadault A, Letourneur F, Nitschke P, Bras M, Vidaud M, Charneau P, Larger E, Colli ML, Eizirik DL, Lemonnier F, Boitard C. A Humanized Mouse Strain That Develops Spontaneously Immune-Mediated Diabetes. Front Immunol 2021; 12:748679. [PMID: 34721418 PMCID: PMC8551915 DOI: 10.3389/fimmu.2021.748679] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 09/22/2021] [Indexed: 12/03/2022] Open
Abstract
To circumvent the limitations of available preclinical models for the study of type 1 diabetes (T1D), we developed a new humanized model, the YES-RIP-hB7.1 mouse. This mouse is deficient of murine major histocompatibility complex class I and class II, the murine insulin genes, and expresses as transgenes the HLA-A*02:01 allele, the diabetes high-susceptibility HLA-DQ8A and B alleles, the human insulin gene, and the human co-stimulatory molecule B7.1 in insulin-secreting cells. It develops spontaneous T1D along with CD4+ and CD8+ T-cell responses to human preproinsulin epitopes. Most of the responses identified in these mice were validated in T1D patients. This model is amenable to characterization of hPPI-specific epitopes involved in T1D and to the identification of factors that may trigger autoimmune response to insulin-secreting cells in human T1D. It will allow evaluating peptide-based immunotherapy that may directly apply to T1D in human and complete preclinical model availability to address the issue of clinical heterogeneity of human disease.
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Affiliation(s)
- Sandrine Luce
- Laboratory Immunology of Diabetes, INSERMU1016, Department EMD, Cochin Institute, Paris, France.,Medical Faculty, Paris University, Paris, France
| | - Sophie Guinoiseau
- Laboratory Immunology of Diabetes, INSERMU1016, Department EMD, Cochin Institute, Paris, France.,Medical Faculty, Paris University, Paris, France
| | - Alexis Gadault
- Laboratory Immunology of Diabetes, INSERMU1016, Department EMD, Cochin Institute, Paris, France.,Medical Faculty, Paris University, Paris, France
| | - Franck Letourneur
- Laboratory Immunology of Diabetes, INSERMU1016, Department EMD, Cochin Institute, Paris, France
| | | | - Marc Bras
- Medical Faculty, Paris University, Paris, France
| | - Michel Vidaud
- Biochemistry and Molecular Genetics Department, Cochin Hospital, Paris, France
| | - Pierre Charneau
- Molecular Virology and Vaccinology, Pasteur Institute, Paris, France
| | - Etienne Larger
- Laboratory Immunology of Diabetes, INSERMU1016, Department EMD, Cochin Institute, Paris, France.,Diabetology Department, Cochin Hospital, Paris, France
| | - Maikel L Colli
- Université Libre de Bruxelles (ULB) Center for Diabetes Research, Medical Faculty, Université Libre de Bruxelles, Brussels, Belgium
| | - Decio L Eizirik
- Université Libre de Bruxelles (ULB) Center for Diabetes Research, Medical Faculty, Université Libre de Bruxelles, Brussels, Belgium.,Diabetes Center, Indiana Biosciences Research Institute (IBRI), Indianapolis, IN, United States
| | - François Lemonnier
- Laboratory Immunology of Diabetes, INSERMU1016, Department EMD, Cochin Institute, Paris, France.,Medical Faculty, Paris University, Paris, France
| | - Christian Boitard
- Laboratory Immunology of Diabetes, INSERMU1016, Department EMD, Cochin Institute, Paris, France.,Medical Faculty, Paris University, Paris, France.,Diabetology Department, Cochin Hospital, Paris, France
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15
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Wu W, Syed F, Simpson E, Lee CC, Liu J, Chang G, Dong C, Seitz C, Eizirik DL, Mirmira RG, Liu Y, Evans-Molina C. The Impact of Pro-Inflammatory Cytokines on Alternative Splicing Patterns in Human Islets. Diabetes 2021; 71:db200847. [PMID: 34697029 PMCID: PMC8763875 DOI: 10.2337/db20-0847] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Accepted: 10/18/2021] [Indexed: 01/05/2023]
Abstract
Alternative splicing (AS) within the β cell has been proposed as one potential pathway that may exacerbate autoimmunity and unveil novel immunogenic epitopes in type 1 diabetes (T1D). We employed a computational strategy to prioritize pathogenic splicing events in human islets treated with IL-1β + IFN-γ as an ex vivo model of T1D and coupled this analysis with a k-mer based approach to predict RNA binding proteins involved in AS. In total, 969 AS events were identified in cytokine-treated islets, with the majority (44.8%) involving a skipped exon. ExonImpact identified 129 events predicted to impact protein structure. AS occurred with high frequency in MHC Class II-related mRNAs, and targeted qPCR validated reduced inclusion of Exon5 in the MHC Class II gene HLA-DMB. Single molecule RNA FISH confirmed increased HLA-DMB splicing in pancreatic sections from human donors with established T1D and autoantibody positivity. Serine and Arginine Rich Splicing Factor 2 was implicated in 37.2% of potentially pathogenic events, including Exon5 exclusion in HLA-DMB. Together, these data suggest that dynamic control of AS plays a role in the β cell response to inflammatory signals during T1D evolution.
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Affiliation(s)
- Wenting Wu
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, USA
- Center for Diabetes and Metabolic Diseases, Indiana University School of Medicine, Indianapolis, Indiana
| | - Farooq Syed
- Center for Diabetes and Metabolic Diseases, Indiana University School of Medicine, Indianapolis, Indiana
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN, USA
- Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Edward Simpson
- Department of BioHealth Informatics, Indiana University School of Informatics and Computing, Indianapolis, IN, USA
| | - Chih-Chun Lee
- Center for Diabetes and Metabolic Diseases, Indiana University School of Medicine, Indianapolis, Indiana
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN, USA
- Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Jing Liu
- Department of Physics, Indiana University-Purdue University Indianapolis, Indianapolis, IN, USA
| | - Garrick Chang
- Department of Physics, Indiana University-Purdue University Indianapolis, Indianapolis, IN, USA
| | - Chuanpeng Dong
- Department of BioHealth Informatics, Indiana University School of Informatics and Computing, Indianapolis, IN, USA
| | - Clayton Seitz
- Department of Physics, Indiana University-Purdue University Indianapolis, Indianapolis, IN, USA
| | - Decio L Eizirik
- ULB Center for Diabetes Research, Medical Faculty, Universitê Libre de Bruxelles (ULB), Brussels, Belgium
- Indiana Biosciences Research Institute (IBRI), Indianapolis, Indiana, USA
| | - Raghavendra G Mirmira
- Kovler Diabetes Center and Department of Medicine, The University of Chicago, Chicago, IL, USA
| | - Yunlong Liu
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Carmella Evans-Molina
- Center for Diabetes and Metabolic Diseases, Indiana University School of Medicine, Indianapolis, Indiana
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN, USA
- Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN, USA
- Richard L. Roudebush VA Medical Center, Indiana University School of Informatics and Computing, Indianapolis, IN, USA
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16
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Eizirik DL, Szymczak F, Alvelos MI, Martin F. From Pancreatic β-Cell Gene Networks to Novel Therapies for Type 1 Diabetes. Diabetes 2021; 70:1915-1925. [PMID: 34417266 PMCID: PMC8576417 DOI: 10.2337/dbi20-0046] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Accepted: 06/10/2021] [Indexed: 12/14/2022]
Abstract
Completion of the Human Genome Project enabled a novel systems- and network-level understanding of biology, but this remains to be applied for understanding the pathogenesis of type 1 diabetes (T1D). We propose that defining the key gene regulatory networks that drive β-cell dysfunction and death in T1D might enable the design of therapies that target the core disease mechanism, namely, the progressive loss of pancreatic β-cells. Indeed, many successful drugs do not directly target individual disease genes but, rather, modulate the consequences of defective steps, targeting proteins located one or two steps downstream. If we transpose this to the T1D situation, it makes sense to target the pathways that modulate the β-cell responses to the immune assault-in relation to signals that may stimulate the immune response (e.g., HLA class I and chemokine overexpression and/or neoantigen expression) or inhibit the invading immune cells (e.g., PDL1 and HLA-E expression)-instead of targeting only the immune system, as it is usually proposed. Here we discuss the importance of a focus on β-cells in T1D, lessons learned from other autoimmune diseases, the "alternative splicing connection," data mining, and drug repurposing to protect β-cells in T1D and then some of the initial candidates under testing for β-cell protection.
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Affiliation(s)
- Decio L Eizirik
- Indiana Biosciences Research Institute, Indianapolis, IN
- ULB Center for Diabetes Research and Welbio, Medical Faculty, Université Libre de Bruxelles, Brussels, Belgium
| | - Florian Szymczak
- ULB Center for Diabetes Research and Welbio, Medical Faculty, Université Libre de Bruxelles, Brussels, Belgium
| | - Maria Inês Alvelos
- ULB Center for Diabetes Research and Welbio, Medical Faculty, Université Libre de Bruxelles, Brussels, Belgium
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17
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Dudek KD, Osipovich AB, Cartailler JP, Gu G, Magnuson MA. Insm1, Neurod1, and Pax6 promote murine pancreatic endocrine cell development through overlapping yet distinct RNA transcription and splicing programs. G3-GENES GENOMES GENETICS 2021; 11:6358139. [PMID: 34534285 PMCID: PMC8527475 DOI: 10.1093/g3journal/jkab303] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 08/19/2021] [Indexed: 11/13/2022]
Abstract
Insm1, Neurod1, and Pax6 are essential for the formation and function of pancreatic endocrine cells. Here, we report comparative immunohistochemical, transcriptomic, functional enrichment, and RNA splicing analyses of these genes using gene knock-out mice. Quantitative immunohistochemical analysis confirmed that elimination of each of these three factors variably impairs the proliferation, survival, and differentiation of endocrine cells. Transcriptomic analysis revealed that each factor contributes uniquely to the transcriptome although their effects were overlapping. Functional enrichment analysis revealed that genes downregulated by the elimination of Insm1, Neurod1, and Pax6 are commonly involved in mRNA metabolism, chromatin organization, secretion, and cell cycle regulation, and upregulated genes are associated with protein degradation, autophagy, and apoptotic process. Elimination of Insm1, Neurod1, and Pax6 impaired expression of many RNA-binding proteins thereby altering RNA splicing events, including for Syt14 and Snap25, two genes required for insulin secretion. All three factors are necessary for normal splicing of Syt14, and both Insm1 and Pax6 are necessary for the processing of Snap25. Collectively, these data provide new insights into how Insm1, Neurod1, and Pax6 contribute to the formation of functional pancreatic endocrine cells.
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Affiliation(s)
- Karrie D Dudek
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37232, USA.,Center for Stem Cell Biology, Vanderbilt University, Nashville, TN 37232, USA
| | - Anna B Osipovich
- Center for Stem Cell Biology, Vanderbilt University, Nashville, TN 37232, USA.,Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232, USA
| | | | - Guoquing Gu
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37232, USA.,Center for Stem Cell Biology, Vanderbilt University, Nashville, TN 37232, USA
| | - Mark A Magnuson
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37232, USA.,Center for Stem Cell Biology, Vanderbilt University, Nashville, TN 37232, USA.,Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232, USA
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18
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Enriched Alternative Splicing in Islets of Diabetes-Susceptible Mice. Int J Mol Sci 2021; 22:ijms22168597. [PMID: 34445304 PMCID: PMC8395343 DOI: 10.3390/ijms22168597] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 07/28/2021] [Accepted: 08/05/2021] [Indexed: 12/30/2022] Open
Abstract
Dysfunctional islets of Langerhans are a hallmark of type 2 diabetes (T2D). We hypothesize that differences in islet gene expression alternative splicing which can contribute to altered protein function also participate in islet dysfunction. RNA sequencing (RNAseq) data from islets of obese diabetes-resistant and diabetes-susceptible mice were analyzed for alternative splicing and its putative genetic and epigenetic modulators. We focused on the expression levels of chromatin modifiers and SNPs in regulatory sequences. We identified alternative splicing events in islets of diabetes-susceptible mice amongst others in genes linked to insulin secretion, endocytosis or ubiquitin-mediated proteolysis pathways. The expression pattern of 54 histones and chromatin modifiers, which may modulate splicing, were markedly downregulated in islets of diabetic animals. Furthermore, diabetes-susceptible mice carry SNPs in RNA-binding protein motifs and in splice sites potentially responsible for alternative splicing events. They also exhibit a larger exon skipping rate, e.g., in the diabetes gene Abcc8, which might affect protein function. Expression of the neuronal splicing factor Srrm4 which mediates inclusion of microexons in mRNA transcripts was markedly lower in islets of diabetes-prone compared to diabetes-resistant mice, correlating with a preferential skipping of SRRM4 target exons. The repression of Srrm4 expression is presumably mediated via a higher expression of miR-326-3p and miR-3547-3p in islets of diabetic mice. Thus, our study suggests that an altered splicing pattern in islets of diabetes-susceptible mice may contribute to an elevated T2D risk.
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19
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Rehman SU, Schallschmidt T, Rasche A, Knebel B, Stermann T, Altenhofen D, Herwig R, Schürmann A, Chadt A, Al-Hasani H. Alternative exon splicing and differential expression in pancreatic islets reveals candidate genes and pathways implicated in early diabetes development. Mamm Genome 2021; 32:153-172. [PMID: 33880624 PMCID: PMC8128753 DOI: 10.1007/s00335-021-09869-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Accepted: 04/03/2021] [Indexed: 12/29/2022]
Abstract
Type 2 diabetes (T2D) has a strong genetic component. Most of the gene variants driving the pathogenesis of T2D seem to target pancreatic β-cell function. To identify novel gene variants acting at early stage of the disease, we analyzed whole transcriptome data to identify differential expression (DE) and alternative exon splicing (AS) transcripts in pancreatic islets collected from two metabolically diverse mouse strains at 6 weeks of age after three weeks of high-fat-diet intervention. Our analysis revealed 1218 DE and 436 AS genes in islets from NZO/Hl vs C3HeB/FeJ. Whereas some of the revealed genes present well-established markers for β-cell failure, such as Cd36 or Aldh1a3, we identified numerous DE/AS genes that have not been described in context with β-cell function before. The gene Lgals2, previously associated with human T2D development, was DE as well as AS and localizes in a quantitative trait locus (QTL) for blood glucose on Chr.15 that we reported recently in our N2(NZOxC3H) population. In addition, pathway enrichment analysis of DE and AS genes showed an overlap of only half of the revealed pathways, indicating that DE and AS in large parts influence different pathways in T2D development. PPARG and adipogenesis pathways, two well-established metabolic pathways, were overrepresented for both DE and AS genes, probably as an adaptive mechanism to cope for increased cellular stress. Our results provide guidance for the identification of novel T2D candidate genes and demonstrate the presence of numerous AS transcripts possibly involved in islet function and maintenance of glucose homeostasis.
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Affiliation(s)
- Sayeed Ur Rehman
- Institute for Clinical Biochemistry and Pathobiochemistry, German Diabetes Center (DDZ), Leibniz Center for Diabetes Research at Heinrich Heine University, Medical Faculty, Duesseldorf, Germany.,German Center for Diabetes Research (DZD), München-Neuherberg, Germany.,Department of Biochemistry, School of Chemical and Life Sciences, Jamia Hamdard, New Delhi, 110062, India
| | - Tanja Schallschmidt
- Institute for Clinical Biochemistry and Pathobiochemistry, German Diabetes Center (DDZ), Leibniz Center for Diabetes Research at Heinrich Heine University, Medical Faculty, Duesseldorf, Germany.,German Center for Diabetes Research (DZD), München-Neuherberg, Germany
| | - Axel Rasche
- Department of Computational Molecular Biology, Max Planck Institute for Molecular Genetics, Berlin, Germany
| | - Birgit Knebel
- Institute for Clinical Biochemistry and Pathobiochemistry, German Diabetes Center (DDZ), Leibniz Center for Diabetes Research at Heinrich Heine University, Medical Faculty, Duesseldorf, Germany.,German Center for Diabetes Research (DZD), München-Neuherberg, Germany
| | - Torben Stermann
- Institute for Clinical Biochemistry and Pathobiochemistry, German Diabetes Center (DDZ), Leibniz Center for Diabetes Research at Heinrich Heine University, Medical Faculty, Duesseldorf, Germany.,German Center for Diabetes Research (DZD), München-Neuherberg, Germany
| | - Delsi Altenhofen
- Institute for Clinical Biochemistry and Pathobiochemistry, German Diabetes Center (DDZ), Leibniz Center for Diabetes Research at Heinrich Heine University, Medical Faculty, Duesseldorf, Germany.,German Center for Diabetes Research (DZD), München-Neuherberg, Germany
| | - Ralf Herwig
- Department of Computational Molecular Biology, Max Planck Institute for Molecular Genetics, Berlin, Germany
| | - Annette Schürmann
- German Center for Diabetes Research (DZD), München-Neuherberg, Germany.,German Institute of Human Nutrition, Potsdam, Germany
| | - Alexandra Chadt
- Institute for Clinical Biochemistry and Pathobiochemistry, German Diabetes Center (DDZ), Leibniz Center for Diabetes Research at Heinrich Heine University, Medical Faculty, Duesseldorf, Germany.,German Center for Diabetes Research (DZD), München-Neuherberg, Germany
| | - Hadi Al-Hasani
- Institute for Clinical Biochemistry and Pathobiochemistry, German Diabetes Center (DDZ), Leibniz Center for Diabetes Research at Heinrich Heine University, Medical Faculty, Duesseldorf, Germany. .,German Center for Diabetes Research (DZD), München-Neuherberg, Germany.
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20
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Rodriguez-Calvo T, Johnson JD, Overbergh L, Dunne JL. Neoepitopes in Type 1 Diabetes: Etiological Insights, Biomarkers and Therapeutic Targets. Front Immunol 2021; 12:667989. [PMID: 33953728 PMCID: PMC8089389 DOI: 10.3389/fimmu.2021.667989] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Accepted: 03/29/2021] [Indexed: 12/12/2022] Open
Abstract
The mechanisms underlying type 1 diabetes (T1D) pathogenesis remain largely unknown. While autoantibodies to pancreatic beta-cell antigens are often the first biological response and thereby a useful biomarker for identifying individuals in early stages of T1D, their role in T1D pathogenesis is not well understood. Recognition of these antigenic targets by autoreactive T-cells plays a pathological role in T1D development. Recently, several beta-cell neoantigens have been described, indicating that both neoantigens and known T1D antigens escape central or peripheral tolerance. Several questions regarding the mechanisms by which tolerance is broken in T1D remain unanswered. Further delineating the timing and nature of antigenic responses could allow their use as biomarkers to improve staging, as targets for therapeutic intervention, and lead to a better understanding of the mechanisms leading to loss of tolerance. Multiple factors that contribute to cellular stress may result in the generation of beta-cell derived neoepitopes and contribute to autoimmunity. Understanding the cellular mechanisms that induce beta-cells to produce neoantigens has direct implications on development of therapies to intercept T1D disease progression. In this perspective, we will discuss evidence for the role of neoantigens in the pathogenesis of T1D, including antigenic responses and cellular mechanisms. We will additionally discuss the pathways leading to neoepitope formation and the cross talk between the immune system and the beta-cells in this regard. Ultimately, delineating the timing of neoepitope generation in T1D pathogenesis will determine their role as biomarkers as well as therapeutic targets.
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Affiliation(s)
- Teresa Rodriguez-Calvo
- Institute of Diabetes Research, Helmholtz Zentrum Muenchen, German Research Center for Environmental Health, Munich, Germany
| | - James D. Johnson
- Diabetes Research Group, Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
| | - Lut Overbergh
- Laboratory Clinical and Experimental Endocrinology, KU Leuven, Leuven, Belgium
| | - Jessica L. Dunne
- Janssen Research and Development, LLC, Raritan, NJ, United States
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21
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Ghiasi SM, Rutter GA. Consequences for Pancreatic β-Cell Identity and Function of Unregulated Transcript Processing. Front Endocrinol (Lausanne) 2021; 12:625235. [PMID: 33763030 PMCID: PMC7984428 DOI: 10.3389/fendo.2021.625235] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 01/26/2021] [Indexed: 12/25/2022] Open
Abstract
Mounting evidence suggests a role for alternative splicing (AS) of transcripts in the normal physiology and pathophysiology of the pancreatic β-cell. In the apparent absence of RNA repair systems, RNA decay pathways are likely to play an important role in controlling the stability, distribution and diversity of transcript isoforms in these cells. Around 35% of alternatively spliced transcripts in human cells contain premature termination codons (PTCs) and are targeted for degradation via nonsense-mediated decay (NMD), a vital quality control process. Inflammatory cytokines, whose levels are increased in both type 1 (T1D) and type 2 (T2D) diabetes, stimulate alternative splicing events and the expression of NMD components, and may or may not be associated with the activation of the NMD pathway. It is, however, now possible to infer that NMD plays a crucial role in regulating transcript processing in normal and stress conditions in pancreatic β-cells. In this review, we describe the possible role of Regulated Unproductive Splicing and Translation (RUST), a molecular mechanism embracing NMD activity in relationship to AS and translation of damaged transcript isoforms in these cells. This process substantially reduces the abundance of non-functional transcript isoforms, and its dysregulation may be involved in pancreatic β-cell failure in diabetes.
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Affiliation(s)
- Seyed M. Ghiasi
- Section of Cell Biology and Functional Genomics, Division of Diabetes, Endocrinology and Metabolism, Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Guy A. Rutter
- Section of Cell Biology and Functional Genomics, Division of Diabetes, Endocrinology and Metabolism, Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, London, United Kingdom
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22
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Roep BO, Thomaidou S, van Tienhoven R, Zaldumbide A. Type 1 diabetes mellitus as a disease of the β-cell (do not blame the immune system?). Nat Rev Endocrinol 2021; 17:150-161. [PMID: 33293704 PMCID: PMC7722981 DOI: 10.1038/s41574-020-00443-4] [Citation(s) in RCA: 233] [Impact Index Per Article: 77.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/04/2020] [Indexed: 02/07/2023]
Abstract
Type 1 diabetes mellitus is believed to result from destruction of the insulin-producing β-cells in pancreatic islets that is mediated by autoimmune mechanisms. The classic view is that autoreactive T cells mistakenly destroy healthy ('innocent') β-cells. We propose an alternative view in which the β-cell is the key contributor to the disease. By their nature and function, β-cells are prone to biosynthetic stress with limited measures for self-defence. β-Cell stress provokes an immune attack that has considerable negative effects on the source of a vital hormone. This view would explain why immunotherapy at best delays progression of type 1 diabetes mellitus and points to opportunities to use therapies that revitalize β-cells, in combination with immune intervention strategies, to reverse the disease. We present the case that dysfunction occurs in both the immune system and β-cells, which provokes further dysfunction, and present the evidence leading to the consensus that islet autoimmunity is an essential component in the pathogenesis of type 1 diabetes mellitus. Next, we build the case for the β-cell as the trigger of an autoimmune response, supported by analogies in cancer and antitumour immunity. Finally, we synthesize a model ('connecting the dots') in which both β-cell stress and islet autoimmunity can be harnessed as targets for intervention strategies.
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Affiliation(s)
- Bart O Roep
- Department of Diabetes Immunology, Diabetes & Metabolism Research Institute, Beckman Research Institute at City of Hope, Los Angeles, CA, USA.
- Department of Internal Medicine, Leiden University Medical Center, Leiden, Netherlands.
| | - Sofia Thomaidou
- Department of Cell and Chemical Biology, Leiden University Medical Center, Leiden, Netherlands
| | - René van Tienhoven
- Department of Diabetes Immunology, Diabetes & Metabolism Research Institute, Beckman Research Institute at City of Hope, Los Angeles, CA, USA
| | - Arnaud Zaldumbide
- Department of Cell and Chemical Biology, Leiden University Medical Center, Leiden, Netherlands
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23
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Alvelos MI, Brüggemann M, Sutandy FXR, Juan-Mateu J, Colli ML, Busch A, Lopes M, Castela Â, Aartsma-Rus A, König J, Zarnack K, Eizirik DL. The RNA-binding profile of the splicing factor SRSF6 in immortalized human pancreatic β-cells. Life Sci Alliance 2021; 4:e202000825. [PMID: 33376132 PMCID: PMC7772782 DOI: 10.26508/lsa.202000825] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 12/15/2020] [Accepted: 12/15/2020] [Indexed: 12/16/2022] Open
Abstract
In pancreatic β-cells, the expression of the splicing factor SRSF6 is regulated by GLIS3, a transcription factor encoded by a diabetes susceptibility gene. SRSF6 down-regulation promotes β-cell demise through splicing dysregulation of central genes for β-cells function and survival, but how RNAs are targeted by SRSF6 remains poorly understood. Here, we define the SRSF6 binding landscape in the human pancreatic β-cell line EndoC-βH1 by integrating individual-nucleotide resolution UV cross-linking and immunoprecipitation (iCLIP) under basal conditions with RNA sequencing after SRSF6 knockdown. We detect thousands of SRSF6 bindings sites in coding sequences. Motif analyses suggest that SRSF6 specifically recognizes a purine-rich consensus motif consisting of GAA triplets and that the number of contiguous GAA triplets correlates with increasing binding site strength. The SRSF6 positioning determines the splicing fate. In line with its role in β-cell function, we identify SRSF6 binding sites on regulated exons in several diabetes susceptibility genes. In a proof-of-principle, the splicing of the susceptibility gene LMO7 is modulated by antisense oligonucleotides. Our present study unveils the splicing regulatory landscape of SRSF6 in immortalized human pancreatic β-cells.
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Affiliation(s)
- Maria Inês Alvelos
- ULB Center for Diabetes Research, Medical Faculty, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - Mirko Brüggemann
- Buchman Institute for Molecular Life Sciences (BMLS), Goethe University Frankfurt, Frankfurt am Main, Germany
- Faculty of Biological Sciences, Goethe University Frankfurt, Frankfurt am Main, Germany
| | | | - Jonàs Juan-Mateu
- ULB Center for Diabetes Research, Medical Faculty, Université Libre de Bruxelles (ULB), Brussels, Belgium
- Centre for Genomic Regulation, The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Maikel Luis Colli
- ULB Center for Diabetes Research, Medical Faculty, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - Anke Busch
- Institute of Molecular Biology gGmbH, Mainz, Germany
| | - Miguel Lopes
- ULB Center for Diabetes Research, Medical Faculty, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - Ângela Castela
- ULB Center for Diabetes Research, Medical Faculty, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | | | - Julian König
- Institute of Molecular Biology gGmbH, Mainz, Germany
| | - Kathi Zarnack
- Buchman Institute for Molecular Life Sciences (BMLS), Goethe University Frankfurt, Frankfurt am Main, Germany
- Faculty of Biological Sciences, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Décio L Eizirik
- ULB Center for Diabetes Research, Medical Faculty, Université Libre de Bruxelles (ULB), Brussels, Belgium
- Welbio, Medical Faculty, Université Libre de Bruxelles (ULB), Brussels, Belgium
- Indiana Biosciences Research Institute, Indianapolis, IN, USA
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24
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Szymczak F, Colli ML, Mamula MJ, Evans-Molina C, Eizirik DL. Gene expression signatures of target tissues in type 1 diabetes, lupus erythematosus, multiple sclerosis, and rheumatoid arthritis. SCIENCE ADVANCES 2021; 7:7/2/eabd7600. [PMID: 33523973 PMCID: PMC7787485 DOI: 10.1126/sciadv.abd7600] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Accepted: 11/16/2020] [Indexed: 05/05/2023]
Abstract
Autoimmune diseases are typically studied with a focus on the immune system, and less attention is paid to responses of target tissues exposed to the immune assault. We presently evaluated, based on available RNA sequencing data, whether inflammation induces similar molecular signatures at the target tissues in type 1 diabetes, systemic lupus erythematosus, multiple sclerosis, and rheumatoid arthritis. We identified confluent signatures, many related to interferon signaling, indicating pathways that may be targeted for therapy, and observed a high (>80%) expression of candidate genes for the different diseases at the target tissue level. These observations suggest that future research on autoimmune diseases should focus on both the immune system and the target tissues, and on their dialog. Discovering similar disease-specific signatures may allow the identification of key pathways that could be targeted for therapy, including the repurposing of drugs already in clinical use for other diseases.
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Affiliation(s)
- F Szymczak
- ULB Center for Diabetes Research, Medical Faculty, Université Libre de Bruxelles (ULB), Brussels, Belgium
- Interuniversity Institute of Bioinformatics in Brussels, Université Libre de Bruxelles-Vrije Universiteit Brussel, Brussels, Belgium
| | - M L Colli
- ULB Center for Diabetes Research, Medical Faculty, Université Libre de Bruxelles (ULB), Brussels, Belgium.
| | - M J Mamula
- Section of Rheumatology, Yale University School of Medicine, New Haven, CT, USA
| | - C Evans-Molina
- Center for Diabetes and Metabolic Diseases, Indiana University School of Medicine, Indianapolis, IN, USA
| | - D L Eizirik
- ULB Center for Diabetes Research, Medical Faculty, Université Libre de Bruxelles (ULB), Brussels, Belgium.
- Indiana Biosciences Research Institute (IBRI), Indianapolis, IN, USA
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25
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Demine S, Schulte ML, Territo PR, Eizirik DL. Beta Cell Imaging-From Pre-Clinical Validation to First in Man Testing. Int J Mol Sci 2020; 21:E7274. [PMID: 33019671 PMCID: PMC7582644 DOI: 10.3390/ijms21197274] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 09/21/2020] [Accepted: 09/28/2020] [Indexed: 12/14/2022] Open
Abstract
There are presently no reliable ways to quantify human pancreatic beta cell mass (BCM) in vivo, which prevents an accurate understanding of the progressive beta cell loss in diabetes or following islet transplantation. Furthermore, the lack of beta cell imaging hampers the evaluation of the impact of new drugs aiming to prevent beta cell loss or to restore BCM in diabetes. We presently discuss the potential value of BCM determination as a cornerstone for individualized therapies in diabetes, describe the presently available probes for human BCM evaluation, and discuss our approach for the discovery of novel beta cell biomarkers, based on the determination of specific splice variants present in human beta cells. This has already led to the identification of DPP6 and FXYD2ga as two promising targets for human BCM imaging, and is followed by a discussion of potential safety issues, the role for radiochemistry in the improvement of BCM imaging, and concludes with an overview of the different steps from pre-clinical validation to a first-in-man trial for novel tracers.
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Affiliation(s)
- Stephane Demine
- Indiana Biosciences Research Institute, Indianapolis, IN 46202, USA;
| | - Michael L. Schulte
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN 46202, USA; (M.L.S.); (P.R.T.)
| | - Paul R. Territo
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN 46202, USA; (M.L.S.); (P.R.T.)
- Division of Clinical Pharmacology, Department of Medicine, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Decio L. Eizirik
- Indiana Biosciences Research Institute, Indianapolis, IN 46202, USA;
- ULB Center for Diabetes Research, Medical Faculty, Université Libre de Bruxelles (ULB), 1070 Brussels, Belgium
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26
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Moss ND, Sussel L. mRNA Processing: An Emerging Frontier in the Regulation of Pancreatic β Cell Function. Front Genet 2020; 11:983. [PMID: 33088281 PMCID: PMC7490333 DOI: 10.3389/fgene.2020.00983] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Accepted: 08/03/2020] [Indexed: 01/04/2023] Open
Abstract
Robust endocrine cell function, particularly β cell function, is required to maintain blood glucose homeostasis. Diabetes can result from the loss or dysfunction of β cells. Despite decades of clinical and basic research, the precise regulation of β cell function and pathogenesis in diabetes remains incompletely understood. In this review, we highlight RNA processing of mRNAs as a rapidly emerging mechanism regulating β cell function and survival. RNA-binding proteins (RBPs) and RNA modifications are primed to be the next frontier to explain many of the poorly understood molecular processes that regulate β cell formation and function, and provide an exciting potential for the development of novel therapeutics. Here we outline the current understanding of β cell specific functions of several characterized RBPs, alternative splicing events, and transcriptome wide changes in RNA methylation. We also highlight several RBPs that are dysregulated in both Type 1 and Type 2 diabetes, and discuss remaining knowledge gaps in the field.
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Affiliation(s)
- Nicole D Moss
- Cell, Stem Cells, and Development Graduate Program, Department of Pediatrics, Barbara Davis Center, University of Colorado Denver Anschutz Medical Campus, Aurora, CO, United States
| | - Lori Sussel
- Cell, Stem Cells, and Development Graduate Program, Department of Pediatrics, Barbara Davis Center, University of Colorado Denver Anschutz Medical Campus, Aurora, CO, United States
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27
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An integrated multi-omics approach identifies the landscape of interferon-α-mediated responses of human pancreatic beta cells. Nat Commun 2020; 11:2584. [PMID: 32444635 PMCID: PMC7244579 DOI: 10.1038/s41467-020-16327-0] [Citation(s) in RCA: 67] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Accepted: 04/23/2020] [Indexed: 12/12/2022] Open
Abstract
Interferon-α (IFNα), a type I interferon, is expressed in the islets of type 1 diabetic individuals, and its expression and signaling are regulated by T1D genetic risk variants and viral infections associated with T1D. We presently characterize human beta cell responses to IFNα by combining ATAC-seq, RNA-seq and proteomics assays. The initial response to IFNα is characterized by chromatin remodeling, followed by changes in transcriptional and translational regulation. IFNα induces changes in alternative splicing (AS) and first exon usage, increasing the diversity of transcripts expressed by the beta cells. This, combined with changes observed on protein modification/degradation, ER stress and MHC class I, may expand antigens presented by beta cells to the immune system. Beta cells also up-regulate the checkpoint proteins PDL1 and HLA-E that may exert a protective role against the autoimmune assault. Data mining of the present multi-omics analysis identifies two compound classes that antagonize IFNα effects on human beta cells. The cytokine IFNα is expressed in the islets of individuals with type 1 diabetes and contributes to local inflammation and destruction of beta cells. Here, the authors provide a global multiomics view of IFNα-induced changes in human beta cells at the level of chromatin, mRNA and protein expression.
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28
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Li N, Zhang S, Xiong F, Eizirik DL, Wang CY. SUMOylation, a multifaceted regulatory mechanism in the pancreatic beta cells. Semin Cell Dev Biol 2020; 103:51-58. [PMID: 32331991 DOI: 10.1016/j.semcdb.2020.03.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2019] [Revised: 01/03/2020] [Accepted: 03/23/2020] [Indexed: 12/19/2022]
Abstract
SUMOylation is an evolutionarily conserved post-translational modification (PTM) that regulates protein subcellular localization, stability, conformation, transcription and enzymatic activity. Recent studies indicate that SUMOylation plays a key role in insulin gene expression, glucose metabolism and insulin exocytosis under physiological conditions in the pancreatic beta cells. Furthermore, SUMOylation is implicated in beta cell survival and recovery following exposure to oxidative stress, ER stress and inflammatory mediators under pathological situations. SUMOylation is closely regulated by the cellular redox status, and it collaborates with other PTMs such as phosphorylation, ubiquitination, and NEDDylation, to maintain beta cellular homeostasis. We hereby provide an update on recent findings regarding the role of SUMOylation in the regulation of pancreatic beta cell viability and function, and discuss its potential implication in beta cell senescence and RNA processing (e.g., pre-mRNA splicing and mRNA methylation). Through which we intend to provide novel insights into this fundamental biological process regarding both maintenance of beta cell viability and functionality, and beta cell dysfunction in diabetes mellitus.
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Affiliation(s)
- Na Li
- The Center for Biomedical Research, Key Laboratory of Organ Transplantation, Ministry of Education, NHC Key Laboratory of Organ Transplantation, Key Laboratory of Organ Transplantation, Chinese Academy of Medical Sciences, Tongji Hospital, Wuhan, China
| | - Shu Zhang
- The Center for Biomedical Research, Key Laboratory of Organ Transplantation, Ministry of Education, NHC Key Laboratory of Organ Transplantation, Key Laboratory of Organ Transplantation, Chinese Academy of Medical Sciences, Tongji Hospital, Wuhan, China
| | - Fei Xiong
- The Center for Biomedical Research, Key Laboratory of Organ Transplantation, Ministry of Education, NHC Key Laboratory of Organ Transplantation, Key Laboratory of Organ Transplantation, Chinese Academy of Medical Sciences, Tongji Hospital, Wuhan, China
| | - Decio L Eizirik
- ULB Center for Diabetes Research, Université Libre de Bruxelles, 808 Route de Lennik, B-1070, Brussels, Belgium; Indiana Biosciences Research Institute (IBRI), Indianapolis, IN, USA.
| | - Cong-Yi Wang
- The Center for Biomedical Research, Key Laboratory of Organ Transplantation, Ministry of Education, NHC Key Laboratory of Organ Transplantation, Key Laboratory of Organ Transplantation, Chinese Academy of Medical Sciences, Tongji Hospital, Wuhan, China.
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29
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Colli ML, Szymczak F, Eizirik DL. Molecular Footprints of the Immune Assault on Pancreatic Beta Cells in Type 1 Diabetes. Front Endocrinol (Lausanne) 2020; 11:568446. [PMID: 33042023 PMCID: PMC7522353 DOI: 10.3389/fendo.2020.568446] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Accepted: 08/17/2020] [Indexed: 12/25/2022] Open
Abstract
Type 1 diabetes (T1D) is a chronic disease caused by the selective destruction of the insulin-producing pancreatic beta cells by infiltrating immune cells. We presently evaluated the transcriptomic signature observed in beta cells in early T1D and compared it with the signatures observed following in vitro exposure of human islets to inflammatory or metabolic stresses, with the aim of identifying "footprints" of the immune assault in the target beta cells. We detected similarities between the beta cell signatures induced by cytokines present at different moments of the disease, i.e., interferon-α (early disease) and interleukin-1β plus interferon-γ (later stages) and the beta cells from T1D patients, identifying biological process and signaling pathways activated during early and late stages of the disease. Among the first responses triggered on beta cells was an enrichment in antiviral responses, pattern recognition receptors activation, protein modification and MHC class I antigen presentation. During putative later stages of insulitis the processes were dominated by T-cell recruitment and activation and attempts of beta cells to defend themselves through the activation of anti-inflammatory pathways (i.e., IL10, IL4/13) and immune check-point proteins (i.e., PDL1 and HLA-E). Finally, we mined the beta cell signature in islets from T1D patients using the Connectivity Map, a large database of chemical compounds/drugs, and identified interesting candidates to potentially revert the effects of insulitis on beta cells.
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Affiliation(s)
- Maikel L. Colli
- ULB Center for Diabetes Research, Medical Faculty, Université Libre de Bruxelles (ULB), Brussels, Belgium
- *Correspondence: Maikel L. Colli
| | - Florian Szymczak
- 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
- Welbio, Medical Faculty, Université Libre de Bruxelles (ULB), Brussels, Belgium
- Indiana Biosciences Research Institute, Indianapolis, IN, United States
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30
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Nakayasu ES, Qian WJ, Evans-Molina C, Mirmira RG, Eizirik DL, Metz TO. The role of proteomics in assessing beta-cell dysfunction and death in type 1 diabetes. Expert Rev Proteomics 2019; 16:569-582. [PMID: 31232620 PMCID: PMC6628911 DOI: 10.1080/14789450.2019.1634548] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Accepted: 06/18/2019] [Indexed: 12/17/2022]
Abstract
Introduction: Type 1 diabetes (T1D) is characterized by autoimmune-induced dysfunction and destruction of the pancreatic beta cells. Unfortunately, this process is poorly understood, and the current best treatment for type 1 diabetes is the administration of exogenous insulin. To better understand these mechanisms and to develop new therapies, there is an urgent need for biomarkers that can reliably predict disease stage. Areas covered: Mass spectrometry (MS)-based proteomics and complementary techniques play an important role in understanding the autoimmune response, inflammation and beta-cell death. MS is also a leading technology for the identification of biomarkers. This, and the technical difficulties and new technologies that provide opportunities to characterize small amounts of sample in great depth and to analyze large sample cohorts will be discussed in this review. Expert opinion: Understanding disease mechanisms and the discovery of disease-associated biomarkers are highly interconnected goals. Ideal biomarkers would be molecules specific to the different stages of the disease process that are released from beta cells to the bloodstream. However, such molecules are likely to be present in trace amounts in the blood due to the small number of pancreatic beta cells in the human body and the heterogeneity of the target organ and disease process.
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Affiliation(s)
- Ernesto S. Nakayasu
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, USA
| | - Wei-Jun Qian
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, USA
| | - Carmella Evans-Molina
- Center for Diabetes and Metabolic Diseases, Herman B. Wells Center for Pediatric Research, Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Raghavendra G. Mirmira
- Center for Diabetes and Metabolic Diseases, Herman B. Wells Center for Pediatric Research, Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Decio L. Eizirik
- ULB Center for Diabetes Research, Medical Faculty, Université Libre de Bruxelles, Brussels, Belgium
| | - Thomas O. Metz
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, USA
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