101
|
Tritschler S, Theis FJ, Lickert H, Böttcher A. Systematic single-cell analysis provides new insights into heterogeneity and plasticity of the pancreas. Mol Metab 2017; 6:974-990. [PMID: 28951822 PMCID: PMC5605721 DOI: 10.1016/j.molmet.2017.06.021] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Revised: 06/13/2017] [Accepted: 06/19/2017] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Diabetes mellitus is characterized by loss or dysfunction of insulin-producing β-cells in the pancreas, resulting in failure of blood glucose regulation and devastating secondary complications. Thus, β-cells are currently the prime target for cell-replacement and regenerative therapy. Triggering endogenous repair is a promising strategy to restore β-cell mass and normoglycemia in diabetic patients. Potential strategies include targeting specific β-cell subpopulations to increase proliferation or maturation. Alternatively, transdifferentiation of pancreatic islet cells (e.g. α- or δ-cells), extra-islet cells (acinar and ductal cells), hepatocytes, or intestinal cells into insulin-producing cells might improve glycemic control. To this end, it is crucial to systematically characterize and unravel the transcriptional program of all pancreatic cell types at the molecular level in homeostasis and disease. Furthermore, it is necessary to better determine the underlying mechanisms of β-cell maturation, maintenance, and dysfunction in diabetes, to identify and molecularly profile endocrine subpopulations with regenerative potential, and to translate the findings from mice to man. Recent approaches in single-cell biology started to illuminate heterogeneity and plasticity in the pancreas that might be targeted for β-cell regeneration in diabetic patients. SCOPE OF REVIEW This review discusses recent literature on single-cell analysis including single-cell RNA sequencing, single-cell mass cytometry, and flow cytometry of pancreatic cell types in the context of mechanisms of endogenous β-cell regeneration. We discuss new findings on the regulation of postnatal β-cell proliferation and maturation. We highlight how single-cell analysis recapitulates described principles of functional β-cell heterogeneity in animal models and adds new knowledge on the extent of β-cell heterogeneity in humans as well as its role in homeostasis and disease. Furthermore, we summarize the findings on cell subpopulations with regenerative potential that might enable the formation of new β-cells in diseased state. Finally, we review new data on the transcriptional program and function of rare pancreatic cell types and their implication in diabetes. MAJOR CONCLUSION Novel, single-cell technologies offer high molecular resolution of cellular heterogeneity within the pancreas and provide information on processes and factors that govern β-cell homeostasis, proliferation, and maturation. Eventually, these technologies might lead to the characterization of cells with regenerative potential and unravel disease-associated changes in gene expression to identify cellular and molecular targets for therapy.
Collapse
Affiliation(s)
- Sophie Tritschler
- Institute of Diabetes and Regeneration Research, Helmholtz Zentrum München, Am Parkring 11, 85748 Garching-Hochbrück, Germany
- German Center for Diabetes Research, 85764 Neuherberg, Germany
- Institute of Computational Biology, Helmholtz Zentrum München, 85764 Neuherberg, Germany
| | - Fabian J. Theis
- Institute of Computational Biology, Helmholtz Zentrum München, 85764 Neuherberg, Germany
| | - Heiko Lickert
- Institute of Diabetes and Regeneration Research, Helmholtz Zentrum München, Am Parkring 11, 85748 Garching-Hochbrück, Germany
- German Center for Diabetes Research, 85764 Neuherberg, Germany
- Institute of Stem Cell Research, Helmholtz Zentrum München, 85764 Neuherberg, Germany
| | - Anika Böttcher
- Institute of Diabetes and Regeneration Research, Helmholtz Zentrum München, Am Parkring 11, 85748 Garching-Hochbrück, Germany
- German Center for Diabetes Research, 85764 Neuherberg, Germany
- Institute of Stem Cell Research, Helmholtz Zentrum München, 85764 Neuherberg, Germany
| |
Collapse
|
102
|
Chen C, Cohrs CM, Stertmann J, Bozsak R, Speier S. Human beta cell mass and function in diabetes: Recent advances in knowledge and technologies to understand disease pathogenesis. Mol Metab 2017; 6:943-957. [PMID: 28951820 PMCID: PMC5605733 DOI: 10.1016/j.molmet.2017.06.019] [Citation(s) in RCA: 288] [Impact Index Per Article: 41.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Revised: 05/31/2017] [Accepted: 06/07/2017] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Plasma insulin levels are predominantly the product of the morphological mass of insulin producing beta cells in the pancreatic islets of Langerhans and the functional status of each of these beta cells. Thus, deficiency in either beta cell mass or function, or both, can lead to insufficient levels of insulin, resulting in hyperglycemia and diabetes. Nonetheless, the precise contribution of beta cell mass and function to the pathogenesis of diabetes as well as the underlying mechanisms are still unclear. In the past, this was largely due to the restricted number of technologies suitable for studying the scarcely accessible human beta cells. However, in recent years, a number of new platforms have been established to expand the available techniques and to facilitate deeper insight into the role of human beta cell mass and function as cause for diabetes and as potential treatment targets. SCOPE OF REVIEW This review discusses the current knowledge about contribution of human beta cell mass and function to different stages of type 1 and type 2 diabetes pathogenesis. Furthermore, it highlights standard and newly developed technological platforms for the study of human beta cell biology, which can be used to increase our understanding of beta cell mass and function in human glucose homeostasis. MAJOR CONCLUSIONS In contrast to early disease models, recent studies suggest that in type 1 and type 2 diabetes impairment of beta cell function is an early feature of disease pathogenesis while a substantial decrease in beta cell mass occurs more closely to clinical manifestation. This suggests that, in addition to beta cell mass replacement for late stage therapies, the development of novel strategies for protection and recovery of beta cell function could be most promising for successful diabetes treatment and prevention. The use of today's developing and wide range of technologies and platforms for the study of human beta cells will allow for a more detailed investigation of the underlying mechanisms and will facilitate development of treatment approaches to specifically target human beta cell mass and function.
Collapse
Affiliation(s)
- Chunguang Chen
- Paul Langerhans Institute Dresden (PLID) of Helmholtz Zentrum München at the University Clinic Carl Gustav Carus of Technische Universität Dresden, Helmholtz Zentrum München, München-Neuherberg, Germany
- German Center for Diabetes Research (DZD), München-Neuherberg, Germany
| | - Christian M. Cohrs
- Paul Langerhans Institute Dresden (PLID) of Helmholtz Zentrum München at the University Clinic Carl Gustav Carus of Technische Universität Dresden, Helmholtz Zentrum München, München-Neuherberg, Germany
- German Center for Diabetes Research (DZD), München-Neuherberg, Germany
| | - Julia Stertmann
- Paul Langerhans Institute Dresden (PLID) of Helmholtz Zentrum München at the University Clinic Carl Gustav Carus of Technische Universität Dresden, Helmholtz Zentrum München, München-Neuherberg, Germany
- German Center for Diabetes Research (DZD), München-Neuherberg, Germany
| | - Robert Bozsak
- Paul Langerhans Institute Dresden (PLID) of Helmholtz Zentrum München at the University Clinic Carl Gustav Carus of Technische Universität Dresden, Helmholtz Zentrum München, München-Neuherberg, Germany
- German Center for Diabetes Research (DZD), München-Neuherberg, Germany
| | - Stephan Speier
- Paul Langerhans Institute Dresden (PLID) of Helmholtz Zentrum München at the University Clinic Carl Gustav Carus of Technische Universität Dresden, Helmholtz Zentrum München, München-Neuherberg, Germany
- German Center for Diabetes Research (DZD), München-Neuherberg, Germany
| |
Collapse
|
103
|
Abstract
Following differentiation during fetal development, β cells further adapt to their postnatal role through functional maturation. While adult islets are thought to contain functionally mature β cells, recent analyses of transgenic rodent and human pancreata reveal a number of novel heterogeneity markers in mammalian β cells. The marked heterogeneity long after maturation raises the prospect that diverse populations harbor distinct roles aside from glucose-stimulated insulin secretion. In this review, we outline our current understanding of the β-cell maturation process, emphasize recent literature on novel heterogeneity markers, and offer perspectives on reconciling the findings from these two areas.
Collapse
Affiliation(s)
- Jennifer S E Liu
- Diabetes Center, Department of Medicine, University of California at San Francisco, San Francisco, California 94143, USA
| | - Matthias Hebrok
- Diabetes Center, Department of Medicine, University of California at San Francisco, San Francisco, California 94143, USA
| |
Collapse
|
104
|
Avrahami D, Klochendler A, Dor Y, Glaser B. Beta cell heterogeneity: an evolving concept. Diabetologia 2017; 60:1363-1369. [PMID: 28597073 PMCID: PMC5554543 DOI: 10.1007/s00125-017-4326-z] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 05/02/2017] [Indexed: 10/19/2022]
Abstract
Beta cells are primarily defined by their ability to produce insulin and secrete it in response to appropriate stimuli. It has been known for some time, however, that beta cells are not functionally identical to each other and that the rates of insulin synthesis and release differ from cell to cell, although the functional significance of this variability remains unclear. Recent studies have used heterogeneous gene expression to isolate and evaluate different subpopulations of beta cells and to demonstrate alterations in these subpopulations in diabetes. In the last few years, novel technologies have emerged that permit the detailed evaluation of the proteome (e.g. time-of-flight mass spectroscopy, [CyTOF]) and transcriptome (e.g. massively parallel RNA sequencing) at the single-cell level, and tools for single beta cell metabolomics and epigenomics are quickly maturing. The first wave of single beta cell proteome and transcriptome studies were published in 2016, giving a glimpse into the power, but also the limitations, of these approaches. Despite this progress, it remains unclear if the observed heterogeneity of beta cells represents stable, distinct beta cell types or, alternatively, highly dynamic beta cell states. Here we provide a concise overview of recent developments in the emerging field of beta cell heterogeneity and the implications for our understanding of beta cell biology and pathology.
Collapse
Affiliation(s)
- Dana Avrahami
- Endocrinology and Metabolism Service, Department of Internal Medicine, Hadassah-Hebrew University Medical Center, POB 12000, 91120, Jerusalem, Israel
| | - Agnes Klochendler
- Department of Developmental Biology and Cancer Research, The Institute for Medical Research Israel-Canada, Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Yuval Dor
- Department of Developmental Biology and Cancer Research, The Institute for Medical Research Israel-Canada, Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Benjamin Glaser
- Endocrinology and Metabolism Service, Department of Internal Medicine, Hadassah-Hebrew University Medical Center, POB 12000, 91120, Jerusalem, Israel.
| |
Collapse
|
105
|
Li C, Ackermann AM, Boodhansingh KE, Bhatti TR, Liu C, Schug J, Doliba N, Han B, Cosgrove KE, Banerjee I, Matschinsky FM, Nissim I, Kaestner KH, Naji A, Adzick NS, Dunne MJ, Stanley CA, De León DD. Functional and Metabolomic Consequences of K ATP Channel Inactivation in Human Islets. Diabetes 2017; 66:1901-1913. [PMID: 28442472 PMCID: PMC5482088 DOI: 10.2337/db17-0029] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Accepted: 04/15/2017] [Indexed: 12/17/2022]
Abstract
Loss-of-function mutations of β-cell KATP channels cause the most severe form of congenital hyperinsulinism (KATPHI). KATPHI is characterized by fasting and protein-induced hypoglycemia that is unresponsive to medical therapy. For a better understanding of the pathophysiology of KATPHI, we examined cytosolic calcium ([Ca2+] i ), insulin secretion, oxygen consumption, and [U-13C]glucose metabolism in islets isolated from the pancreases of children with KATPHI who required pancreatectomy. Basal [Ca2+] i and insulin secretion were higher in KATPHI islets compared with controls. Unlike controls, insulin secretion in KATPHI islets increased in response to amino acids but not to glucose. KATPHI islets have an increased basal rate of oxygen consumption and mitochondrial mass. [U-13C]glucose metabolism showed a twofold increase in alanine levels and sixfold increase in 13C enrichment of alanine in KATPHI islets, suggesting increased rates of glycolysis. KATPHI islets also exhibited increased serine/glycine and glutamine biosynthesis. In contrast, KATPHI islets had low γ-aminobutyric acid (GABA) levels and lacked 13C incorporation into GABA in response to glucose stimulation. The expression of key genes involved in these metabolic pathways was significantly different in KATPHI β-cells compared with control, providing a mechanism for the observed changes. These findings demonstrate that the pathophysiology of KATPHI is complex, and they provide a framework for the identification of new potential therapeutic targets for this devastating condition.
Collapse
Affiliation(s)
- Changhong Li
- Division of Endocrinology and Diabetes, Department of Pediatrics, The Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Amanda M Ackermann
- Division of Endocrinology and Diabetes, Department of Pediatrics, The Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Kara E Boodhansingh
- Division of Endocrinology and Diabetes, Department of Pediatrics, The Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Tricia R Bhatti
- Department of Pathology, The Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Chengyang Liu
- Department of Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Jonathan Schug
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Nicolai Doliba
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Bing Han
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, U.K
| | - Karen E Cosgrove
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, U.K
| | - Indraneel Banerjee
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, U.K
| | - Franz M Matschinsky
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Itzhak Nissim
- Division of Metabolism, The Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Klaus H Kaestner
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Ali Naji
- Department of Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - N Scott Adzick
- Department of Surgery, The Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Mark J Dunne
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, U.K
| | - Charles A Stanley
- Division of Endocrinology and Diabetes, Department of Pediatrics, The Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Diva D De León
- Division of Endocrinology and Diabetes, Department of Pediatrics, The Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
- Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| |
Collapse
|
106
|
Huang L, Michael SA, Chen Y, Wu H. Current Advances in Highly Multiplexed Antibody-Based Single-Cell Proteomic Measurements. Chem Asian J 2017; 12:1680-1691. [PMID: 28493387 DOI: 10.1002/asia.201700404] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Revised: 05/08/2017] [Indexed: 12/29/2022]
Abstract
Single-cell measurements have played a critical role in revealing the complex signaling dynamics and heterogeneity present in cells, but there is still much to learn. Measuring samples from bulk populations of cells often masks the information and dynamics present in subsets of cells. Common single-cell protein studies rely on fluorescent microscopy and flow cytometry but are limited in multiplexing ability owing to spectral overlap. Recently, technology advancements in single-cell proteomics have allowed highly multiplexed measurement of multiple parameters simultaneously by using barcoded microfluidic enzyme-linked immunosorbent assays and mass cytometry techniques. In this review, we will describe recent work around multiparameter single-cell protein measurements and critically analyze the techniques.
Collapse
Affiliation(s)
- Lu Huang
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
| | - Sean A Michael
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
| | - Yangfan Chen
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
| | - Hongkai Wu
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
| |
Collapse
|
107
|
Golson ML, Kaestner KH. Epigenetics in formation, function, and failure of the endocrine pancreas. Mol Metab 2017; 6:1066-1076. [PMID: 28951829 PMCID: PMC5605720 DOI: 10.1016/j.molmet.2017.05.015] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Revised: 05/16/2017] [Accepted: 05/22/2017] [Indexed: 01/17/2023] Open
Abstract
Background Epigenetics, in the broadest sense, governs all aspects of the life of any multicellular organism, as it controls how differentiated cells arrive at their unique phenotype during development and differentiation, despite having a uniform (with some exceptions such as T-cells and germ cells) genetic make-up. The endocrine pancreas is no exception. Transcriptional regulators and epigenetic modifiers shape the differentiation of the five major endocrine cell types from their common precursor in the fetal pancreatic bud. Beyond their role in cell differentiation, interactions of the organism with the environment are also often encoded into permanent or semi-permanent epigenetic marks and affect cellular behavior and organismal health. Epigenetics is defined as any heritable – at least through one mitotic cell division – change in phenotype or trait that is not the result of a change in genomic DNA sequence, and it forms the basis that mediates the environmental impact on diabetes susceptibility and islet function. Scope of review We will summarize the impact of epigenetic regulation on islet cell development, maturation, function, and pathophysiology. We will briefly recapitulate the major epigenetic marks and their relationship to gene activity, and outline novel strategies to employ targeted epigenetic modifications as a tool to improve islet cell function. Major conclusions The improved understanding of the epigenetic underpinnings of islet cell differentiation, function and breakdown, as well as the development of innovative tools for their manipulation, is key to islet cell biology and the discovery of novel approaches to therapies for islet cell failure.
Collapse
Affiliation(s)
- Maria L Golson
- University of Pennsylvania, Department of Genetics and Institute for Diabetes, Obesity, and Metabolism, Philadelphia, PA, USA
| | - Klaus H Kaestner
- University of Pennsylvania, Department of Genetics and Institute for Diabetes, Obesity, and Metabolism, Philadelphia, PA, USA
| |
Collapse
|
108
|
Carrano AC, Mulas F, Zeng C, Sander M. Interrogating islets in health and disease with single-cell technologies. Mol Metab 2017; 6:991-1001. [PMID: 28951823 PMCID: PMC5605723 DOI: 10.1016/j.molmet.2017.04.012] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2017] [Revised: 04/10/2017] [Accepted: 04/11/2017] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Blood glucose levels are tightly controlled by the coordinated actions of hormone-producing endocrine cells that reside in pancreatic islets. Islet cell malfunction underlies diabetes development and progression. Due to the cellular heterogeneity within islets, it has been challenging to uncover how specific islet cells contribute to glucose homeostasis and diabetes pathogenesis. Recent advances in single-cell technologies and computational methods have opened up new avenues to resolve islet heterogeneity and study islet cell states in health and disease. SCOPE OF REVIEW In the past year, a multitude of studies have been published that used single-cell approaches to interrogate the transcriptome and proteome of the different islet cell types. Here, we summarize the conclusions of these studies, as well as discuss the technologies used and the challenges faced with computational analysis of single-cell data from islet studies. MAJOR CONCLUSIONS By analyzing single islet cells from rodents and humans at different ages and disease states, the studies reviewed here have provided new insight into endocrine cell function and facilitated a high resolution molecular characterization of poorly understood processes, including regeneration, maturation, and diabetes pathogenesis. Gene expression programs and pathways identified in these studies pave the way for the discovery of new targets and approaches to prevent, monitor, and treat diabetes.
Collapse
Affiliation(s)
- Andrea C Carrano
- Departments of Pediatrics and Cellular & Molecular Medicine, Pediatric Diabetes Research Center, University of California, San Diego, 2880 Torrey Pines Scenic Drive, La Jolla, CA 92037, USA
| | - Francesca Mulas
- Departments of Pediatrics and Cellular & Molecular Medicine, Pediatric Diabetes Research Center, University of California, San Diego, 2880 Torrey Pines Scenic Drive, La Jolla, CA 92037, USA
| | - Chun Zeng
- Departments of Pediatrics and Cellular & Molecular Medicine, Pediatric Diabetes Research Center, University of California, San Diego, 2880 Torrey Pines Scenic Drive, La Jolla, CA 92037, USA
| | - Maike Sander
- Departments of Pediatrics and Cellular & Molecular Medicine, Pediatric Diabetes Research Center, University of California, San Diego, 2880 Torrey Pines Scenic Drive, La Jolla, CA 92037, USA
| |
Collapse
|
109
|
Wang W, Liu C, Jimenez-Gonzalez M, Song WJ, Hussain MA. The undoing and redoing of the diabetic β-cell. J Diabetes Complications 2017; 31:912-917. [PMID: 28242267 PMCID: PMC5450161 DOI: 10.1016/j.jdiacomp.2017.01.028] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Revised: 12/23/2016] [Accepted: 01/31/2017] [Indexed: 02/08/2023]
Abstract
A hallmark of type 2 diabetes (T2DM) is the reduction in functional β-cell mass, which is considered at least in part to result from an imbalance of β-cell renewal and apoptosis, with the latter being accelerated during metabolic stress. More recent studies, however, suggest that the loss of functional β-cell mass is not as much due to β-cell death but rather to de-differentiation of β-cells when these cells are exposed to metabolic stressors, opening the possibility to re-differentiate and restore functional β-cell mass by therapeutic intervention. In parallel, clinical observations suggest that temporary intensive insulin therapy in early diagnosed humans with T2DM, so as to "rest" endogenous β-cells, allows these patients to regain adequate insulin secretion and to maintain euglycemia for prolonged periods free of continued pharmacotherapy. Whether observations made in (mostly rodent) models of diabetes mellitus and in clinical trials are revealing identical mechanisms and therapeutic opportunities remains a tantalizing possibility. Our intention is for this review to serve as an overview of the field and commentary of this particularly exciting field of research.
Collapse
Affiliation(s)
- Wei Wang
- Metabolism Division, Departments of Pediatrics, Medicine and Biological Chemistry, Johns Hopkins University School of Medicine, 600 N Wolfe Street, CMSC 10-113, Baltimore, MD 21287
| | - Chune Liu
- Metabolism Division, Departments of Pediatrics, Medicine and Biological Chemistry, Johns Hopkins University School of Medicine, 600 N Wolfe Street, CMSC 10-113, Baltimore, MD 21287
| | - Maria Jimenez-Gonzalez
- Metabolism Division, Departments of Pediatrics, Medicine and Biological Chemistry, Johns Hopkins University School of Medicine, 600 N Wolfe Street, CMSC 10-113, Baltimore, MD 21287
| | - Woo-Jin Song
- Metabolism Division, Departments of Pediatrics, Medicine and Biological Chemistry, Johns Hopkins University School of Medicine, 600 N Wolfe Street, CMSC 10-113, Baltimore, MD 21287
| | - Mehboob A Hussain
- Metabolism Division, Departments of Pediatrics, Medicine and Biological Chemistry, Johns Hopkins University School of Medicine, 600 N Wolfe Street, CMSC 10-113, Baltimore, MD 21287.
| |
Collapse
|
110
|
Abstract
PURPOSE OF REVIEW This report examines recent publications identifying phenotypic and functional heterogeneity among pancreatic β cells and investigating their potential roles in normal and abnormal islet function. The development of new methods and tools for the study of individual islet cells has produced a surge of interest in this topic. RECENT FINDINGS Studies of β cell maturation and pregnancy-induced proliferation have identified changes in serotonin and transcription factors SIX2/3 expression as markers of temporal heterogeneity. Structural and functional heterogeneity in the form of functionally distinct 'hub' and 'follower' β cells was found in mouse islets. Heterogeneous expression of Fltp (in mouse β cells) and ST8SIA1 and CD9 (in human β cells) were associated with distinct functional potential. Several impressive reports describing the transcriptomes of individual β cells were also published in recent months. Some of these reveal previously unknown β cell subpopulations. SUMMARY A wealth of information on functional and phenotypic heterogeneity has been collected recently, including the transcriptomes of individual β cells and the identities of functionally distinct β cell subpopulations. Several studies suggest the existence of two broad categories: a more proliferative but less functional and a less proliferative but more functional β cell type. The identification of functionally distinct subpopulations and their association with type 2 diabetes underlines the potential clinical importance of these investigations.
Collapse
Affiliation(s)
- Chaoxing Yang
- Program in Molecular Medicine, Diabetes Center of Excellence, University of Massachusetts Medical School, Worcester, Massachusetts
| | - Feorillo Galivo
- Oregon Stem Cell Center, Papé Family Pediatric Institute, Oregon Health & Science University, Portland, Oregon, USA
| | - Craig Dorrell
- Oregon Stem Cell Center, Papé Family Pediatric Institute, Oregon Health & Science University, Portland, Oregon, USA
| |
Collapse
|
111
|
Hunter CS, Stein RW. Evidence for Loss in Identity, De-Differentiation, and Trans-Differentiation of Islet β-Cells in Type 2 Diabetes. Front Genet 2017; 8:35. [PMID: 28424732 PMCID: PMC5372778 DOI: 10.3389/fgene.2017.00035] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Accepted: 03/13/2017] [Indexed: 01/31/2023] Open
Abstract
The two main types of diabetes mellitus have distinct etiologies, yet a similar outcome: loss of islet β-cell function that is solely responsible for the secretion of the insulin hormone to reduce elevated plasma glucose toward euglycemic levels. Type 1 diabetes (T1D) has traditionally been characterized by autoimmune-mediated β-cell death leading to insulin-dependence, whereas type 2 diabetes (T2D) has hallmarks of peripheral insulin resistance, β-cell dysfunction, and cell death. However, a growing body of evidence suggests that, especially during T2D, key components of β-cell failure involves: (1) loss of cell identity, specifically proteins associated with mature cell function (e.g., insulin and transcription factors like MAFA, PDX1, and NKX6.1), as well as (2) de-differentiation, defined by regression to a progenitor or stem cell-like state. New technologies have allowed the field to compare islet cell characteristics from normal human donors to those under pathophysiological conditions by single cell RNA-Sequencing and through epigenetic analysis. This has revealed a remarkable level of heterogeneity among histologically defined "insulin-positive" β-cells. These results not only suggest that these β-cell subsets have different responses to insulin secretagogues, but that defining their unique gene expression and epigenetic modification profiles will offer opportunities to develop cellular therapeutics to enrich/maintain certain subsets for correcting pathological glucose levels. In this review, we will summarize the recent literature describing how β-cell heterogeneity and plasticity may be influenced in T2D, and various possible avenues of therapeutic intervention.
Collapse
Affiliation(s)
- Chad S Hunter
- Division of Endocrinology, Diabetes and Metabolism, Comprehensive Diabetes Center and Department of Medicine, University of Alabama at BirminghamBirmingham, AL, USA
| | - Roland W Stein
- Department of Molecular Physiology and Biophysics, Vanderbilt UniversityNashville, TN, USA
| |
Collapse
|
112
|
Gutierrez GD, Gromada J, Sussel L. Heterogeneity of the Pancreatic Beta Cell. Front Genet 2017; 8:22. [PMID: 28321233 PMCID: PMC5337801 DOI: 10.3389/fgene.2017.00022] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Accepted: 02/14/2017] [Indexed: 01/06/2023] Open
Abstract
The pancreatic beta cell functions as a key regulator of blood glucose levels by integrating a variety of signals in response to changing metabolic demands. Variations in beta cell identity that translate into functionally different subpopulations represent an interesting mechanism to allow beta cells to efficiently respond to diverse physiological and pathophysiological conditions. Recently, there is emerging evidence that morphological and functional differences between beta cells exist. Furthermore, the ability of novel single cell technologies to characterize the molecular identity of individual beta cells has created a new era in the beta cell field. These studies are providing important novel information about the origin of beta cell heterogeneity, the type and proportions of the different beta cell subpopulations, as well as their intrinsic properties. Furthermore, characterization of different beta cell subpopulations that could variably offer protection from or drive progression of diabetes has important clinical implications in diabetes prevention, beta cell regeneration and stem cell treatments. In this review, we will assess the evidence that supports the existence of heterogeneous populations of beta cells and the factors that could influence their formation. We will also address novel studies using islet single cell analysis that have provided important information toward understanding beta cell heterogeneity and discuss the caveats that may be associated with these new technologies.
Collapse
Affiliation(s)
| | | | - Lori Sussel
- Barbara Davis Center for Diabetes, University of Colorado, Denver CO, USA
| |
Collapse
|
113
|
Affiliation(s)
- Anne Grapin-Botton
- From the Danish Stem Cell Center (DanStem), Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen
| | - Palle Serup
- From the Danish Stem Cell Center (DanStem), Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen
| |
Collapse
|
114
|
Lawlor N, Khetan S, Ucar D, Stitzel ML. Genomics of Islet (Dys)function and Type 2 Diabetes. Trends Genet 2017; 33:244-255. [PMID: 28245910 DOI: 10.1016/j.tig.2017.01.010] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Accepted: 01/30/2017] [Indexed: 12/28/2022]
Abstract
Pancreatic islet dysfunction and beta cell failure are hallmarks of type 2 diabetes mellitus (T2DM) pathogenesis. In this review, we discuss how genome-wide association studies (GWASs) and recent developments in islet (epi)genome and transcriptome profiling (particularly single cell analyses) are providing novel insights into the genetic, environmental, and cellular contributions to islet (dys)function and T2DM pathogenesis. Moving forward, study designs that interrogate and model genetic variation [e.g., allelic profiling and (epi)genome editing] will be critical to dissect the molecular genetics of T2DM pathogenesis, to build next-generation cellular and animal models, and to develop precision medicine approaches to detect, treat, and prevent islet (dys)function and T2DM.
Collapse
Affiliation(s)
- Nathan Lawlor
- The Jackson Laboratory for Genomic Medicine, Farmington, CT 06032, USA
| | - Shubham Khetan
- The Jackson Laboratory for Genomic Medicine, Farmington, CT 06032, USA; Department of Genetics & Genome Sciences, University of Connecticut, Farmington, CT 06032, USA
| | - Duygu Ucar
- The Jackson Laboratory for Genomic Medicine, Farmington, CT 06032, USA; Institute for Systems Genomics, University of Connecticut, Farmington, CT 06032, USA
| | - Michael L Stitzel
- The Jackson Laboratory for Genomic Medicine, Farmington, CT 06032, USA; Department of Genetics & Genome Sciences, University of Connecticut, Farmington, CT 06032, USA; Institute for Systems Genomics, University of Connecticut, Farmington, CT 06032, USA.
| |
Collapse
|