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Jiang H, Jiang FX. Human pluripotent stem cell-derived β cells: Truly immature islet β cells for type 1 diabetes therapy? World J Stem Cells 2023; 15:182-195. [PMID: 37180999 PMCID: PMC10173812 DOI: 10.4252/wjsc.v15.i4.182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Revised: 01/30/2023] [Accepted: 03/20/2023] [Indexed: 04/26/2023] Open
Abstract
A century has passed since the Nobel Prize winning discovery of insulin, which still remains the mainstay treatment for type 1 diabetes mellitus (T1DM) to this day. True to the words of its discoverer Sir Frederick Banting, “insulin is not a cure for diabetes, it is a treatment”, millions of people with T1DM are dependent on daily insulin medications for life. Clinical donor islet transplantation has proven that T1DM is curable, however due to profound shortages of donor islets, it is not a mainstream treatment option for T1DM. Human pluripotent stem cell derived insulin-secreting cells, pervasively known as stem cell-derived β cells (SC-β cells), are a promising alternative source and have the potential to become a T1DM treatment through cell replacement therapy. Here we briefly review how islet β cells develop and mature in vivo and several types of reported SC-β cells produced using different ex vivo protocols in the last decade. Although some markers of maturation were expressed and glucose stimulated insulin secretion was shown, the SC-β cells have not been directly compared to their in vivo counterparts, generally have limited glucose response, and are not yet fully matured. Due to the presence of extra-pancreatic insulin-expressing cells, and ethical and technological issues, further clarification of the true nature of these SC-β cells is required.
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Affiliation(s)
- Helen Jiang
- Sir Charles Gairdner Hospital, University of Western Australia, Perth 6009, Australia
| | - Fang-Xu Jiang
- School of Biomedical Sciences, University of Western Australia, Perth 6009, Australia
- School of Health and Medical Sciences, Edith Cowan University, Perth 6027, Australia
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2
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Abstract
The ability to maintain normoglycaemia, through glucose-sensitive insulin release, is a key aspect of postnatal beta cell function. However, terminally differentiated beta cell identity does not necessarily imply functional maturity. Beta cell maturation is therefore a continuation of beta cell development, albeit a process that occurs postnatally in mammals. Although many important features have been identified in the study of beta cell maturation, as of yet no unified mechanistic model of beta cell functional maturity exists. Here, we review recent findings about the underlying mechanisms of beta cell functional maturation. These findings include systemic hormonal and nutritional triggers that operate through energy-sensing machinery shifts within beta cells, resulting in primed metabolic states that allow for appropriate glucose trafficking and, ultimately, insulin release. We also draw attention to the expansive synergistic nature of these pathways and emphasise that beta cell maturation is dependent on overlapping regulatory and metabolic networks.
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Affiliation(s)
- Tom Barsby
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland.
| | - Timo Otonkoski
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland.
- Children's Hospital, Helsinki University Hospital and University of Helsinki, Helsinki, Finland.
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3
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Scrt1, a transcriptional regulator of β-cell proliferation identified by differential chromatin accessibility during islet maturation. Sci Rep 2021; 11:8800. [PMID: 33888791 PMCID: PMC8062533 DOI: 10.1038/s41598-021-88003-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 03/25/2021] [Indexed: 12/12/2022] Open
Abstract
Glucose-induced insulin secretion, a hallmark of mature β-cells, is achieved after birth and is preceded by a phase of intense proliferation. These events occurring in the neonatal period are decisive for establishing an appropriate functional β-cell mass that provides the required insulin throughout life. However, key regulators of gene expression involved in functional maturation of β-cells remain to be elucidated. Here, we addressed this issue by mapping open chromatin regions in newborn versus adult rat islets using the ATAC-seq assay. We obtained a genome-wide picture of chromatin accessible sites (~ 100,000) among which 20% were differentially accessible during maturation. An enrichment analysis of transcription factor binding sites identified a group of transcription factors that could explain these changes. Among them, Scrt1 was found to act as a transcriptional repressor and to control β-cell proliferation. Interestingly, Scrt1 expression was controlled by the transcriptional repressor RE-1 silencing transcription factor (REST) and was increased in an in vitro reprogramming system of pancreatic exocrine cells to β-like cells. Overall, this study led to the identification of several known and unforeseen key transcriptional events occurring during β-cell maturation. These findings will help defining new strategies to induce the functional maturation of surrogate insulin-producing cells.
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4
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Insulin/Glucose-Responsive Cells Derived from Induced Pluripotent Stem Cells: Disease Modeling and Treatment of Diabetes. Cells 2020; 9:cells9112465. [PMID: 33198288 PMCID: PMC7696367 DOI: 10.3390/cells9112465] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 11/03/2020] [Accepted: 11/09/2020] [Indexed: 12/21/2022] Open
Abstract
Type 2 diabetes, characterized by dysfunction of pancreatic β-cells and insulin resistance in peripheral organs, accounts for more than 90% of all diabetes. Despite current developments of new drugs and strategies to prevent/treat diabetes, there is no ideal therapy targeting all aspects of the disease. Restoration, however, of insulin-producing β-cells, as well as insulin-responsive cells, would be a logical strategy for the treatment of diabetes. In recent years, generation of transplantable cells derived from stem cells in vitro has emerged as an important research area. Pluripotent stem cells, either embryonic or induced, are alternative and feasible sources of insulin-secreting and glucose-responsive cells. This notwithstanding, consistent generation of robust glucose/insulin-responsive cells remains challenging. In this review, we describe basic concepts of the generation of induced pluripotent stem cells and subsequent differentiation of these into pancreatic β-like cells, myotubes, as well as adipocyte- and hepatocyte-like cells. Use of these for modeling of human disease is now feasible, while development of replacement therapies requires continued efforts.
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5
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Helman A, Cangelosi AL, Davis JC, Pham Q, Rothman A, Faust AL, Straubhaar JR, Sabatini DM, Melton DA. A Nutrient-Sensing Transition at Birth Triggers Glucose-Responsive Insulin Secretion. Cell Metab 2020; 31:1004-1016.e5. [PMID: 32375022 PMCID: PMC7480404 DOI: 10.1016/j.cmet.2020.04.004] [Citation(s) in RCA: 95] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 01/14/2020] [Accepted: 03/31/2020] [Indexed: 12/31/2022]
Abstract
A drastic transition at birth, from constant maternal nutrient supply in utero to intermittent postnatal feeding, requires changes in the metabolic system of the neonate. Despite their central role in metabolic homeostasis, little is known about how pancreatic β cells adjust to the new nutritional challenge. Here, we find that after birth β cell function shifts from amino acid- to glucose-stimulated insulin secretion in correlation with the change in the nutritional environment. This adaptation is mediated by a transition in nutrient sensitivity of the mTORC1 pathway, which leads to intermittent mTORC1 activity. Disrupting nutrient sensitivity of mTORC1 in mature β cells reverts insulin secretion to a functionally immature state. Finally, manipulating nutrient sensitivity of mTORC1 in stem cell-derived β cells in vitro strongly enhances their glucose-responsive insulin secretion. These results reveal a mechanism by which nutrients regulate β cell function, thereby enabling a metabolic adaptation for the newborn.
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Affiliation(s)
- Aharon Helman
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138, USA.
| | - Andrew L Cangelosi
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA; Howard Hughes Medical Institute, Cambridge, MA 02139, USA; Koch Institute for Integrative Cancer Research, Cambridge, MA 02139, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Jeffrey C Davis
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138, USA
| | - Quan Pham
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138, USA
| | - Arielle Rothman
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138, USA
| | - Aubrey L Faust
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138, USA
| | - Juerg R Straubhaar
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138, USA
| | - David M Sabatini
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA; Howard Hughes Medical Institute, Cambridge, MA 02139, USA; Koch Institute for Integrative Cancer Research, Cambridge, MA 02139, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA.
| | - Douglas A Melton
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138, USA; Howard Hughes Medical Institute, Cambridge, MA 02139, USA.
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6
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Wortham M, Benthuysen JR, Wallace M, Savas JN, Mulas F, Divakaruni AS, Liu F, Albert V, Taylor BL, Sui Y, Saez E, Murphy AN, Yates JR, Metallo CM, Sander M. Integrated In Vivo Quantitative Proteomics and Nutrient Tracing Reveals Age-Related Metabolic Rewiring of Pancreatic β Cell Function. Cell Rep 2019; 25:2904-2918.e8. [PMID: 30517875 PMCID: PMC6317899 DOI: 10.1016/j.celrep.2018.11.031] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Revised: 09/06/2018] [Accepted: 11/05/2018] [Indexed: 01/02/2023] Open
Abstract
Pancreatic β cell physiology changes substantially throughout life, yet the mechanisms that drive these changes are poorly understood. Here, we performed comprehensive in vivo quantitative proteomic profiling of pancreatic islets from juvenile and 1-year-old mice. The analysis revealed striking differences in abundance of enzymes controlling glucose metabolism. We show that these changes in protein abundance are associated with higher activities of glucose metabolic enzymes involved in coupling factor generation as well as increased activity of the coupling factor-dependent amplifying pathway of insulin secretion. Nutrient tracing and targeted metabolomics demonstrated accelerated accumulation of glucose-derived metabolites and coupling factors in islets from 1-year-old mice, indicating that age-related changes in glucose metabolism contribute to improved glucose-stimulated insulin secretion with age. Together, our study provides an in-depth characterization of age-related changes in the islet proteome and establishes metabolic rewiring as an important mechanism for age-associated changes in β cell function. Organismal age impacts fundamental aspects of β cell physiology. Wortham et al. apply proteomics and targeted metabolomics to islets from juvenile and adult mice, revealing age-related changes in metabolic enzyme abundance and production of coupling factors that enhance insulin secretion. This work provides insight into age-associated changes to the β cell.
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Affiliation(s)
- Matthew Wortham
- Departments of Pediatrics and Cellular & Molecular Medicine, Pediatric Diabetes Research Center, University of California, San Diego, La Jolla, CA 92093, USA
| | - Jacqueline R Benthuysen
- Departments of Pediatrics and Cellular & Molecular Medicine, Pediatric Diabetes Research Center, University of California, San Diego, La Jolla, CA 92093, USA
| | - Martina Wallace
- Department of Bioengineering, University of California, San Diego, La Jolla, CA 92037, USA
| | - Jeffrey N Savas
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Francesca Mulas
- Departments of Pediatrics and Cellular & Molecular Medicine, Pediatric Diabetes Research Center, University of California, San Diego, La Jolla, CA 92093, USA
| | - Ajit S Divakaruni
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92037, USA
| | - Fenfen Liu
- Departments of Pediatrics and Cellular & Molecular Medicine, Pediatric Diabetes Research Center, University of California, San Diego, La Jolla, CA 92093, USA
| | - Verena Albert
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Brandon L Taylor
- Departments of Pediatrics and Cellular & Molecular Medicine, Pediatric Diabetes Research Center, University of California, San Diego, La Jolla, CA 92093, USA
| | - Yinghui Sui
- Departments of Pediatrics and Cellular & Molecular Medicine, Pediatric Diabetes Research Center, University of California, San Diego, La Jolla, CA 92093, USA
| | - Enrique Saez
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Anne N Murphy
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92037, USA
| | - John R Yates
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Christian M Metallo
- Department of Bioengineering, University of California, San Diego, La Jolla, CA 92037, USA
| | - Maike Sander
- Departments of Pediatrics and Cellular & Molecular Medicine, Pediatric Diabetes Research Center, University of California, San Diego, La Jolla, CA 92093, USA.
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7
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Aguayo-Mazzucato C, Andle J, Lee TB, Midha A, Talemal L, Chipashvili V, Hollister-Lock J, van Deursen J, Weir G, Bonner-Weir S. Acceleration of β Cell Aging Determines Diabetes and Senolysis Improves Disease Outcomes. Cell Metab 2019; 30:129-142.e4. [PMID: 31155496 PMCID: PMC6610720 DOI: 10.1016/j.cmet.2019.05.006] [Citation(s) in RCA: 316] [Impact Index Per Article: 52.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Revised: 02/28/2019] [Accepted: 05/01/2019] [Indexed: 12/18/2022]
Abstract
Type 2 diabetes (T2D) is an age-related disease. Although changes in function and proliferation of aged β cells resemble those preceding the development of diabetes, the contribution of β cell aging and senescence remains unclear. We generated a β cell senescence signature and found that insulin resistance accelerates β cell senescence leading to loss of function and cellular identity and worsening metabolic profile. Senolysis (removal of senescent cells), using either a transgenic INK-ATTAC model or oral ABT263, improved glucose metabolism and β cell function while decreasing expression of markers of aging, senescence, and senescence-associated secretory profile (SASP). Beneficial effects of senolysis were observed in an aging model as well as with insulin resistance induced both pharmacologically (S961) and physiologically (high-fat diet). Human senescent β cells also responded to senolysis, establishing the foundation for translation. These novel findings lay the framework to pursue senolysis of β cells as a preventive and alleviating strategy for T2D.
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Affiliation(s)
| | - Joshua Andle
- Joslin Diabetes Center, Harvard Medical School, Boston, MA 02215, USA
| | - Terrence B Lee
- Joslin Diabetes Center, Harvard Medical School, Boston, MA 02215, USA
| | - Ayush Midha
- Joslin Diabetes Center, Harvard Medical School, Boston, MA 02215, USA
| | - Lindsay Talemal
- Joslin Diabetes Center, Harvard Medical School, Boston, MA 02215, USA
| | - Vaja Chipashvili
- Joslin Diabetes Center, Harvard Medical School, Boston, MA 02215, USA
| | | | - Jan van Deursen
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN 55905, USA
| | - Gordon Weir
- Joslin Diabetes Center, Harvard Medical School, Boston, MA 02215, USA
| | - Susan Bonner-Weir
- Joslin Diabetes Center, Harvard Medical School, Boston, MA 02215, USA
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8
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Aguayo-Mazzucato C, Lee TB, Matzko M, DiIenno A, Rezanejad H, Ramadoss P, Scanlan T, Zavacki AM, Larsen PR, Hollenberg A, Colton C, Sharma A, Bonner-Weir S. T 3 Induces Both Markers of Maturation and Aging in Pancreatic β-Cells. Diabetes 2018; 67:1322-1331. [PMID: 29625991 PMCID: PMC6014556 DOI: 10.2337/db18-0030] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Accepted: 03/29/2018] [Indexed: 12/25/2022]
Abstract
Previously, we showed that thyroid hormone (TH) triiodothyronine (T3) enhanced β-cell functional maturation through induction of Mafa High levels of T3 have been linked to decreased life span in mammals and low levels to lengthened life span, suggesting a relationship between TH and aging. Here, we show that T3 increased p16Ink4a (a β-cell senescence marker and effector) mRNA in rodent and human β-cells. The kinetics of Mafa and p16Ink4a induction suggested both genes as targets of TH via TH receptors (THRs) binding to specific response elements. Using specific agonists CO23 and GC1, we showed that p16Ink4a expression was controlled by THRA and Mafa by THRB. Using chromatin immunoprecipitation and a transient transfection yielding biotinylated THRB1 or THRA isoforms to achieve specificity, we determined that THRA isoform bound to p16Ink4a , whereas THRB1 bound to Mafa but not to p16Ink4a On a cellular level, T3 treatment accelerated cell senescence as shown by increased number of β-cells with acidic β-galactosidase activity. Our data show that T3 can simultaneously induce both maturation (Mafa) and aging (p16Ink4a ) effectors and that these dichotomous effects are mediated through different THR isoforms. These findings may be important for further improving stem cell differentiation protocols to produce functional β-cells for replacement therapies in diabetes.
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Affiliation(s)
| | - Terence B Lee
- Joslin Diabetes Center, Harvard Medical School, Boston, MA
| | | | - Amanda DiIenno
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA
| | | | - Preeti Ramadoss
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, MA
| | - Thomas Scanlan
- Department of Physiology & Pharmacology, Oregon Health & Science University, Portland, OR
| | - Ann Marie Zavacki
- Thyroid Section, Division of Endocrinology, Diabetes and Hypertension, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA
| | - P Reed Larsen
- Thyroid Section, Division of Endocrinology, Diabetes and Hypertension, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA
| | - Anthony Hollenberg
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, MA
| | - Clark Colton
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA
| | - Arun Sharma
- Joslin Diabetes Center, Harvard Medical School, Boston, MA
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9
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Kropp PA, Dunn JC, Carboneau BA, Stoffers DA, Gannon M. Cooperative function of Pdx1 and Oc1 in multipotent pancreatic progenitors impacts postnatal islet maturation and adaptability. Am J Physiol Endocrinol Metab 2018; 314:E308-E321. [PMID: 29351489 PMCID: PMC5966755 DOI: 10.1152/ajpendo.00260.2017] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The transcription factors pancreatic and duodenal homeobox 1 (Pdx1) and onecut1 (Oc1) are coexpressed in multipotent pancreatic progenitors (MPCs), but their expression patterns diverge in hormone-expressing cells, with Oc1 expression being extinguished in the endocrine lineage and Pdx1 being maintained at high levels in β-cells. We previously demonstrated that cooperative function of these two factors in MPCs is necessary for proper specification and differentiation of pancreatic endocrine cells. In those studies, we observed a persistent decrease in expression of the β-cell maturity factor MafA. We therefore hypothesized that Pdx1 and Oc1 cooperativity in MPCs impacts postnatal β-cell maturation and function. Here our model of Pdx1-Oc1 double heterozygosity was used to investigate the impact of haploinsufficiency for both of these factors on postnatal β-cell maturation, function, and adaptability. Examining mice at postnatal day (P) 14, we observed alterations in pancreatic insulin content in both Pdx1 heterozygotes and double heterozygotes. Gene expression analysis at this age revealed significantly decreased expression of many genes important for glucose-stimulated insulin secretion (e.g., Glut2, Pcsk1/2, Abcc8) exclusively in double heterozygotes. Analysis of P14 islets revealed an increase in the number of mixed islets in double heterozygotes. We predicted that double-heterozygous β-cells would have an impaired ability to respond to stress. Indeed, we observed that β-cell proliferation fails to increase in double heterozygotes in response to either high-fat diet or placental lactogen. We thus report here the importance of cooperation between regulatory factors early in development for postnatal islet maturation and adaptability.
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Affiliation(s)
- Peter A Kropp
- Department of Molecular Physiology and Biophysics, Vanderbilt University , Nashville, Tennessee
| | - Jennifer C Dunn
- Department of Veterans Affairs, Tennessee Valley Health Authority, Vanderbilt University , Nashville, Tennessee
- Department of Medicine, Vanderbilt University , Nashville, Tennessee
| | - Bethany A Carboneau
- Department of Veterans Affairs, Tennessee Valley Health Authority, Vanderbilt University , Nashville, Tennessee
- Department of Molecular Physiology and Biophysics, Vanderbilt University , Nashville, Tennessee
| | - Doris A Stoffers
- Department of Medicine, Institute for Diabetes, Obesity, and Metabolism, Perelman School of Medicine, University of Pennsylvania , Philadelphia, Pennsylvania
| | - Maureen Gannon
- Department of Veterans Affairs, Tennessee Valley Health Authority, Vanderbilt University , Nashville, Tennessee
- Department of Molecular Physiology and Biophysics, Vanderbilt University , Nashville, Tennessee
- Department of Medicine, Vanderbilt University , Nashville, Tennessee
- Department of Cell and Developmental Biology, Vanderbilt University , Nashville, Tennessee
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10
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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.
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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
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11
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Sinagoga KL, Stone WJ, Schiesser JV, Schweitzer JI, Sampson L, Zheng Y, Wells JM. Distinct roles for the mTOR pathway in postnatal morphogenesis, maturation and function of pancreatic islets. Development 2017; 144:2402-2414. [PMID: 28576773 DOI: 10.1242/dev.146316] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Accepted: 05/26/2017] [Indexed: 02/03/2023]
Abstract
While much is known about the molecular pathways that regulate embryonic development and adult homeostasis of the endocrine pancreas, little is known about what regulates early postnatal development and maturation of islets. Given that birth marks the first exposure to enteral nutrition, we investigated how nutrient-regulated signaling pathways influence postnatal islet development in mice. We performed loss-of-function studies of mechanistic target of rapamycin (mTOR), a highly conserved kinase within a nutrient-sensing pathway known to regulate cellular growth, morphogenesis and metabolism. Deletion of Mtor in pancreatic endocrine cells had no significant effect on their embryonic development. However, within the first 2 weeks after birth, mTOR-deficient islets became dysmorphic, β-cell maturation and function were impaired, and animals lost islet mass. Moreover, we discovered that these distinct functions of mTOR are mediated by separate downstream branches of the pathway, in that mTORC1 (with adaptor protein Raptor) is the main complex mediating the maturation and function of islets, whereas mTORC2 (with adaptor protein Rictor) impacts islet mass and architecture. Taken together, these findings suggest that nutrient sensing may be an essential trigger for postnatal β-cell maturation and islet development.
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Affiliation(s)
- Katie L Sinagoga
- Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave, Cincinnati, OH 45229-3039, USA
| | - William J Stone
- Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave, Cincinnati, OH 45229-3039, USA
| | - Jacqueline V Schiesser
- Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave, Cincinnati, OH 45229-3039, USA
| | - Jamie I Schweitzer
- Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave, Cincinnati, OH 45229-3039, USA
| | - Leesa Sampson
- Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave, Cincinnati, OH 45229-3039, USA
| | - Yi Zheng
- Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave, Cincinnati, OH 45229-3039, USA
| | - James M Wells
- Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave, Cincinnati, OH 45229-3039, USA .,Division of Endocrinology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave, Cincinnati, OH 45229-3039, USA
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12
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β Cell Aging Markers Have Heterogeneous Distribution and Are Induced by Insulin Resistance. Cell Metab 2017; 25:898-910.e5. [PMID: 28380379 PMCID: PMC5471618 DOI: 10.1016/j.cmet.2017.03.015] [Citation(s) in RCA: 151] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Revised: 01/10/2017] [Accepted: 03/21/2017] [Indexed: 01/09/2023]
Abstract
We hypothesized that the known heterogeneity of pancreatic β cells was due to subpopulations of β cells at different stages of their life cycle with different functional capacities and that further changes occur with metabolic stress and aging. We identified new markers of aging in β cells, including IGF1R. In β cells IGF1R expression correlated with age, dysfunction, and expression of known age markers p16ink4a, p53BP1, and senescence-associated β-galactosidase. The new markers showed striking heterogeneity both within and between islets in both mouse and human pancreas. Acute induction of insulin resistance with an insulin receptor antagonist or chronic ER stress resulted in increased expression of aging markers, providing insight into how metabolic stress might accelerate dysfunction and decline of β cells. These novel findings about β cell and islet heterogeneity, and how they change with age, open up an entirely new set of questions about the pathogenesis of type 2 diabetes.
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13
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Quiclet C, Siti F, Dubouchaud H, Vial G, Berthon P, Fontaine E, Batandier C, Couturier K. Short-term and long-term effects of submaximal maternal exercise on offspring glucose homeostasis and pancreatic function. Am J Physiol Endocrinol Metab 2016; 311:E508-18. [PMID: 27382034 DOI: 10.1152/ajpendo.00126.2016] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Accepted: 07/01/2016] [Indexed: 12/22/2022]
Abstract
Only a few studies have explored the effects of maternal exercise during gestation on adult offspring metabolism. We set out to test whether maternal controlled submaximal exercise maintained troughout all gestational periods induces persistant metabolic changes in the offspring. We used a model of 15-wk-old nulliparous female Wistar rats that exercised (trained group) before and during gestation at a submaximal intensity or remained sedentary (control group). At weaning, male offspring from trained dams showed reduced basal glycemia (119.7 ± 2.4 vs. 130.5 ± 4.1 mg/dl, P < 0.05), pancreas relative weight (3.96 ± 0.18 vs. 4.54 ± 0.14 g/kg body wt, P < 0.05), and islet mean area (22,822 ± 4,036 vs. 44,669 ± 6,761 μm(2), P < 0.05) compared with pups from control dams. Additionally, they had better insulin secretory capacity when stimulated by 2.8 mM glucose + 20 mM arginine compared with offspring from control dams (+96%, P < 0.05). At 7 mo of age, offspring from trained mothers displayed altered glucose tolerance (AUC = 15,285 ± 527 vs. 11,898 ± 988 mg·dl(-1)·120 min, P < 0.05) and decreased muscle insulin sensitivity estimated by the phosphorylated PKB/total PKB ratio (-32%, P < 0.05) and tended to have a reduced islet insulin secretory capacity compared with rats from control dams. These results suggest that submaximal maternal exercise modifies short-term male offspring pancreatic function and appears to have rather negative long-term consequences on sedentary adult offspring glucose handling.
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Affiliation(s)
- Charline Quiclet
- Laboratory of Fundamental and Applied Bioenergetics, University Grenoble Alpes, Grenoble, France; Institut National de la Santé et de la Recherche Médicale (INSERM), U1055, Grenoble, France; Unité de Formation et de Recherche en Activités Physiques et Sportives, Structure Fédérative de Recherche Sport Exercice Motricité, University Grenoble Alpes, Grenoble, France;
| | - Farida Siti
- Laboratory of Fundamental and Applied Bioenergetics, University Grenoble Alpes, Grenoble, France; Institut National de la Santé et de la Recherche Médicale (INSERM), U1055, Grenoble, France; Faculty of Universitas Indonesia, Jakarta, Indonesia
| | - Hervé Dubouchaud
- Laboratory of Fundamental and Applied Bioenergetics, University Grenoble Alpes, Grenoble, France; Institut National de la Santé et de la Recherche Médicale (INSERM), U1055, Grenoble, France; Unité de Formation et de Recherche en Activités Physiques et Sportives, Structure Fédérative de Recherche Sport Exercice Motricité, University Grenoble Alpes, Grenoble, France
| | - Guillaume Vial
- INSERM, U1060,Faculté de Médecine Lyon-Sud, Oullins, France; Center for European Nutrition and Health, Centre Hospitalier Lyon-Sud, Pierre-Bénite, France
| | - Phanélie Berthon
- Laboratoire Interuniversitaire de Biologie de la Motricité, University Savoie Mont Blanc, Le Bourget du Lac, France
| | - Eric Fontaine
- Laboratory of Fundamental and Applied Bioenergetics, University Grenoble Alpes, Grenoble, France; Institut National de la Santé et de la Recherche Médicale (INSERM), U1055, Grenoble, France; Grenoble University Hospital, Grenoble, France; and
| | - Cécile Batandier
- Laboratory of Fundamental and Applied Bioenergetics, University Grenoble Alpes, Grenoble, France; Institut National de la Santé et de la Recherche Médicale (INSERM), U1055, Grenoble, France
| | - Karine Couturier
- Laboratory of Fundamental and Applied Bioenergetics, University Grenoble Alpes, Grenoble, France; Institut National de la Santé et de la Recherche Médicale (INSERM), U1055, Grenoble, France; Unité de Formation et de Recherche en Activités Physiques et Sportives, Structure Fédérative de Recherche Sport Exercice Motricité, University Grenoble Alpes, Grenoble, France
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Abstract
After birth the endocrine pancreas continues its development, a complex process that involves both the maturation of islet cells and a marked expansion of their numbers. New beta cells are formed both by duplication of pre-existing cells and by new differentiation (neogenesis) across the first postnatal weeks, with the result of beta cells of different stages of maturation even after weaning. Improving our understanding of this period of beta cell expansion could provide valuable therapeutic insights.
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Affiliation(s)
- Susan Bonner-Weir
- CONTACT Susan Bonner-Weir Joslin Diabetes Center, Harvard Medical School, Boston, MA 02215, USA
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15
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Yoshihara E, Wei Z, Lin CS, Fang S, Ahmadian M, Kida Y, Tseng T, Dai Y, Yu RT, Liddle C, Atkins AR, Downes M, Evans RM. ERRγ Is Required for the Metabolic Maturation of Therapeutically Functional Glucose-Responsive β Cells. Cell Metab 2016; 23:622-34. [PMID: 27076077 PMCID: PMC4832237 DOI: 10.1016/j.cmet.2016.03.005] [Citation(s) in RCA: 144] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Revised: 02/23/2016] [Accepted: 03/10/2016] [Indexed: 12/31/2022]
Abstract
Pancreatic β cells undergo postnatal maturation to achieve maximal glucose-responsive insulin secretion, an energy intensive process. We identify estrogen-related receptor γ (ERRγ) expression as a hallmark of adult, but not neonatal β cells. Postnatal induction of ERRγ drives a transcriptional network activating mitochondrial oxidative phosphorylation, the electron transport chain, and ATP production needed to drive glucose-responsive insulin secretion. Mice deficient in β cell-specific ERRγ expression are glucose intolerant and fail to secrete insulin in response to a glucose challenge. Notably, forced expression of ERRγ in iPSC-derived β-like cells enables glucose-responsive secretion of human insulin in vitro, obviating in vivo maturation to achieve functionality. Moreover, these cells rapidly rescue diabetes when transplanted into β cell-deficient mice. These results identify a key role for ERRγ in β cell metabolic maturation, and offer a reproducible, quantifiable, and scalable approach for in vitro generation of functional human β cell therapeutics.
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Affiliation(s)
- Eiji Yoshihara
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Zong Wei
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Chun Shi Lin
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Sungsoon Fang
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA; College of Life Sciences, Sejong University, Seoul 143-762, Korea
| | - Maryam Ahmadian
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Yasuyuki Kida
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA; Research Center for Stem Cell Engineering, National Institute of Advanced Industrial Science and Technology, Central 4, 1-1-4 Higashi, Tsukuba 305-8562, Japan
| | - Tiffany Tseng
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Yang Dai
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Ruth T Yu
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Christopher Liddle
- Storr Liver Centre, Westmead Millennium Institute, Sydney Medical School, University of Sydney, NSW 2006, Australia
| | - Annette R Atkins
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Michael Downes
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA.
| | - Ronald M Evans
- Gene Expression Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA; Howard Hughes Medical Institute, Salk Institute for Biological Studies, La Jolla, CA 92037, USA.
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16
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El Khattabi I, Sharma A. Proper activation of MafA is required for optimal differentiation and maturation of pancreatic β-cells. Best Pract Res Clin Endocrinol Metab 2015; 29:821-31. [PMID: 26696512 PMCID: PMC4690007 DOI: 10.1016/j.beem.2015.09.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
A key therapeutic approach for the treatment of Type 1 diabetes (T1D) is transplantation of functional islet β-cells. Despite recent advances in generating stem cell-derived glucose-responsive insulin(+) cells, their further maturation to fully functional adult β-cells still remains a daunting task. Conquering this hurdle will require a better understanding of the mechanisms driving maturation of embryonic insulin(+) cells into adult β-cells, and the implementation of that knowledge to improve current differentiation protocols. Here, we will review our current understanding of β-cell maturation, and discuss the contribution of key β-cell transcription factor MafA, to this process. The fundamental importance of MafA in regulating adult β-cell maturation and function indicates that enhancing MafA expression may improve the generation of definitive β-cells for transplantation. Additionally, we suggest that the temporal control of MafA induction at a specific stage of β-cell differentiation will be the next critical challenge for achieving optimum maturation of β-cells.
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Affiliation(s)
| | - Arun Sharma
- Cardiovascular and Metabolic Diseases, MedImmune, Gaithersburg, MD 20878, USA.
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17
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Aguayo-Mazzucato C, DiIenno A, Hollister-Lock J, Cahill C, Sharma A, Weir G, Colton C, Bonner-Weir S. MAFA and T3 Drive Maturation of Both Fetal Human Islets and Insulin-Producing Cells Differentiated From hESC. J Clin Endocrinol Metab 2015; 100. [PMID: 26207953 PMCID: PMC4596039 DOI: 10.1210/jc.2015-2632] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
CONTEXT Human embryonic stem cells (hESCs) differentiated toward β-cells and fetal human pancreatic islet cells resemble each other transcriptionally and are characterized by immaturity with a lack of glucose responsiveness, low levels of insulin content, and impaired proinsulin-to-insulin processing. However, their response to stimuli that promote functionality have not been compared. OBJECTIVE The objective of the study was to evaluate the effects of our previous strategies for functional maturation developed in rodents in these two human models of β-cell immaturity and compare their responses. Design, Settings, Participants, and Interventions: In proof-of-principle experiments using either adenoviral-mediated overexpression of V-Maf avian musculoaponeurotic fibrosarcoma oncogene homolog A (MAFA) or the physiologically driven path via thyroid hormone (T3) and human fetal islet-like cluster (ICC) functional maturity was evaluated. Then the effects of T3 were evaluated upon the functional maturation of hESCs differentiated toward β-cells. MAIN OUTCOME MEASURES Functional maturation was evaluated by the following parameters: glucose responsiveness, insulin content, expression of the mature β-cell transcription factor MAFA, and proinsulin-to-insulin processing. RESULTS ICCs responded positively to MAFA overexpression and T3 treatment as assessed by two different maturation parameters: increased insulin secretion at 16.8 mM glucose and increased proinsulin-to-insulin processing. In hESCs differentiated toward β-cells, T3 enhanced MAFA expression, increased insulin content (probably mediated by the increased MAFA), and increased insulin secretion at 16.8 mM glucose. CONCLUSION T3 is a useful in vitro stimulus to promote human β-cell maturation as shown in both human fetal ICCs and differentiated hESCs. The degree of maturation induced varied in the two models, possibly due to the different developmental status at the beginning of the study.
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Affiliation(s)
- Cristina Aguayo-Mazzucato
- Joslin Diabetes Center (C.A.-M., J.H.-L., C.Ca., A.S., G.W., S.B.-W.), Harvard Medical School, Boston, Massachusetts 02215; and Department of Chemical Engineering (A.D., C.Co.), Massachusetts Institute of Technology, Cambridge, Massachusetts 02139-4307
| | - Amanda DiIenno
- Joslin Diabetes Center (C.A.-M., J.H.-L., C.Ca., A.S., G.W., S.B.-W.), Harvard Medical School, Boston, Massachusetts 02215; and Department of Chemical Engineering (A.D., C.Co.), Massachusetts Institute of Technology, Cambridge, Massachusetts 02139-4307
| | - Jennifer Hollister-Lock
- Joslin Diabetes Center (C.A.-M., J.H.-L., C.Ca., A.S., G.W., S.B.-W.), Harvard Medical School, Boston, Massachusetts 02215; and Department of Chemical Engineering (A.D., C.Co.), Massachusetts Institute of Technology, Cambridge, Massachusetts 02139-4307
| | - Christopher Cahill
- Joslin Diabetes Center (C.A.-M., J.H.-L., C.Ca., A.S., G.W., S.B.-W.), Harvard Medical School, Boston, Massachusetts 02215; and Department of Chemical Engineering (A.D., C.Co.), Massachusetts Institute of Technology, Cambridge, Massachusetts 02139-4307
| | - Arun Sharma
- Joslin Diabetes Center (C.A.-M., J.H.-L., C.Ca., A.S., G.W., S.B.-W.), Harvard Medical School, Boston, Massachusetts 02215; and Department of Chemical Engineering (A.D., C.Co.), Massachusetts Institute of Technology, Cambridge, Massachusetts 02139-4307
| | - Gordon Weir
- Joslin Diabetes Center (C.A.-M., J.H.-L., C.Ca., A.S., G.W., S.B.-W.), Harvard Medical School, Boston, Massachusetts 02215; and Department of Chemical Engineering (A.D., C.Co.), Massachusetts Institute of Technology, Cambridge, Massachusetts 02139-4307
| | - Clark Colton
- Joslin Diabetes Center (C.A.-M., J.H.-L., C.Ca., A.S., G.W., S.B.-W.), Harvard Medical School, Boston, Massachusetts 02215; and Department of Chemical Engineering (A.D., C.Co.), Massachusetts Institute of Technology, Cambridge, Massachusetts 02139-4307
| | - Susan Bonner-Weir
- Joslin Diabetes Center (C.A.-M., J.H.-L., C.Ca., A.S., G.W., S.B.-W.), Harvard Medical School, Boston, Massachusetts 02215; and Department of Chemical Engineering (A.D., C.Co.), Massachusetts Institute of Technology, Cambridge, Massachusetts 02139-4307
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18
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Human fetal pancreatic islet-like structures as source material to treat type 1 diabetes. Stem Cell Res Ther 2014; 4:159. [PMID: 24377429 PMCID: PMC4054946 DOI: 10.1186/scrt389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
The incidence of type 1 diabetes is increasing worldwide. Current therapy continues to be suboptimal. An exciting therapeutic advance in the short term is closed loop technology development and application. However, cell and tissue therapy continues to be an unmet need for the disorder. Human islets isolated from deceased donors will be clinically available to treat type 1 diabetes within the next 1 to 2 years. Other approaches such as xenotransplantation and islet products derived from human embryonic stem cells and induced pluripotent stem cells are currently being pursued. The current commentary provides context and discusses future endeavors for transplantation of islet-like structures derived from fetal pancreas.
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Zhou Y, Waanders LF, Holmseth S, Guo C, Berger UV, Li Y, Lehre AC, Lehre KP, Danbolt NC. Proteome analysis and conditional deletion of the EAAT2 glutamate transporter provide evidence against a role of EAAT2 in pancreatic insulin secretion in mice. J Biol Chem 2013; 289:1329-44. [PMID: 24280215 DOI: 10.1074/jbc.m113.529065] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Islet function is incompletely understood in part because key steps in glutamate handling remain undetermined. The glutamate (excitatory amino acid) transporter 2 (EAAT2; Slc1a2) has been hypothesized to (a) provide islet cells with glutamate, (b) protect islet cells against high extracellular glutamate concentrations, (c) mediate glutamate release, or (d) control the pH inside insulin secretory granules. Here we floxed the EAAT2 gene to produce the first conditional EAAT2 knock-out mice. Crossing with Nestin-cyclization recombinase (Cre) eliminated EAAT2 from the brain, resulting in epilepsy and premature death, confirming the importance of EAAT2 for brain function and validating the genetic construction. Crossing with insulin-Cre lines (RIP-Cre and IPF1-Cre) to obtain pancreas-selective deletion did not appear to affect survival, growth, glucose tolerance, or β-cell number. We found (using TaqMan RT-PCR, immunoblotting, immunocytochemistry, and proteome analysis) that the EAAT2 levels were too low to support any of the four hypothesized functions. The proteome analysis detected more than 7,000 islet proteins of which more than 100 were transporters. Although mitochondrial glutamate transporters and transporters for neutral amino acids were present at high levels, all other transporters with known ability to transport glutamate were strikingly absent. Glutamate-metabolizing enzymes were abundant. The level of glutamine synthetase was 2 orders of magnitude higher than that of glutaminase. Taken together this suggests that the uptake of glutamate by islets from the extracellular fluid is insignificant and that glutamate is intracellularly produced. Glutamine synthetase may be more important for islets than assumed previously.
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Affiliation(s)
- Yun Zhou
- From The Neurotransporter Group, Department of Anatomy, Institute of Basic Medical Sciences, University of Oslo, 0317 Oslo, Norway
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20
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Guo L, Inada A, Aguayo-Mazzucato C, Hollister-Lock J, Fujitani Y, Weir GC, Wright CV, Sharma A, Bonner-Weir S. PDX1 in ducts is not required for postnatal formation of β-cells but is necessary for their subsequent maturation. Diabetes 2013; 62:3459-68. [PMID: 23775765 PMCID: PMC3781453 DOI: 10.2337/db12-1833] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Pancreatic duodenal homeobox-1 (Pdx1), a transcription factor required for pancreatic development and maintenance of β-cell function, was assessed for a possible role in postnatal β-cell formation from progenitors in the pancreatic ducts by selectively deleting Pdx1 from the ducts. Carbonic anhydrase II (CAII)(Cre);Pdx1(Fl) mice were euglycemic for the first 2 postnatal weeks but showed moderate hyperglycemia from 3 to 7 weeks of age. By 10 weeks, they had near-normal morning fed glucose levels but showed severely impaired glucose tolerance and insulin secretion. Yet the loss of Pdx1 did not result in decreased islet and β-cell mass at 4 and 10 weeks of age. Within the same pancreas, there was a mixed population of islets, with PDX1 and MAFA protein expression normal in some cells and severely diminished in others. Even at 10 weeks, islets expressed immaturity markers. Thus, we conclude that Pdx1 is not necessary for the postnatal formation of β-cells but is essential for their full maturation to glucose-responsive β-cells.
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Affiliation(s)
- Lili Guo
- Section of Islet Cell and Regenerative Biology, Joslin Diabetes Center, Department of Medicine, Harvard Medical School, Boston, Massachusetts
| | - Akari Inada
- Section of Islet Cell and Regenerative Biology, Joslin Diabetes Center, Department of Medicine, Harvard Medical School, Boston, Massachusetts
- Diabetes and Genes, Advanced Medical Initiatives, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Cristina Aguayo-Mazzucato
- Section of Islet Cell and Regenerative Biology, Joslin Diabetes Center, Department of Medicine, Harvard Medical School, Boston, Massachusetts
| | - Jennifer Hollister-Lock
- Section of Islet Cell and Regenerative Biology, Joslin Diabetes Center, Department of Medicine, Harvard Medical School, Boston, Massachusetts
| | - Yoshio Fujitani
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Gordon C. Weir
- Section of Islet Cell and Regenerative Biology, Joslin Diabetes Center, Department of Medicine, Harvard Medical School, Boston, Massachusetts
| | - Christopher V.E. Wright
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Arun Sharma
- Section of Islet Cell and Regenerative Biology, Joslin Diabetes Center, Department of Medicine, Harvard Medical School, Boston, Massachusetts
| | - Susan Bonner-Weir
- Section of Islet Cell and Regenerative Biology, Joslin Diabetes Center, Department of Medicine, Harvard Medical School, Boston, Massachusetts
- Corresponding author: Susan Bonner-Weir,
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21
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Abstract
This commentary discusses the concept of β-cell dedifferentiation in diabetes, which is important but not well defined. A broad interpretation is that a state of differentiation has been lost, which means changes in gene expression as well as in structural and functional elements. Thus, a fully mature healthy β cell will have its unique differentiation characteristics, but maturing cells and old β cells will have different patterns of gene expression and might therefore be considered as dedifferentiated. The meaning of dedifferentiation is now being debated because β cells in the diabetic state lose components of their differentiated state, which results in severe dysfunction of insulin secretion. The major cause of this change is thought to be glucose toxicity (glucotoxicity) and that lowering glucose levels with treatment results in some restoration of function. An issue to be discussed is whether dedifferentiated β cells return to a multipotent precursor cell phenotype or whether they follow a different pathway of dedifferentiation.
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22
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El Khattabi I, Sharma A. Preventing p38 MAPK-mediated MafA degradation ameliorates β-cell dysfunction under oxidative stress. Mol Endocrinol 2013; 27:1078-90. [PMID: 23660596 PMCID: PMC3706838 DOI: 10.1210/me.2012-1346] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2012] [Accepted: 04/30/2013] [Indexed: 12/19/2022] Open
Abstract
The reduction in the expression of glucose-responsive insulin gene transcription factor MafA accompanies the development of β-cell dysfunction under oxidative stress/diabetic milieu. Humans with type 2 diabetes have reduced MafA expression, and thus preventing this reduction could overcome β-cell dysfunction and diabetes. We previously showed that p38 MAPK, but not glycogen synthase kinase 3 (GSK3), is a major regulator of MafA degradation under oxidative stress. Here, we examined the mechanisms of this degradation and whether preventing MafA degradation under oxidative stress will overcome β-cell dysfunction. We show that under oxidative and nonoxidative conditions p38 MAPK directly binds to MafA and triggers MafA degradation via ubiquitin proteasomal pathway. However, unlike nonoxidative conditions, MafA degradation under oxidative stress depended on p38 MAPK-mediated phosphorylation at threonine (T) 134, and not T57. Furthermore the expression of alanine (A) 134-MafA, but not A57-MafA, reduced the oxidative stress-mediated loss of glucose-stimulated insulin secretion, which was independent of p38 MAPK action on protein kinase D, a regulator of insulin secretion. Interestingly, the expression of proteasomal activator PA28γ that degrades GSK3-phosphorylated (including T57) MafA was reduced under oxidative stress, explaining the dominance of p38 MAPK over the GSK3 pathway in regulating MafA stability under oxidative stress. These results identify two distinct pathways mediating p38 MAPK-dependent MafA degradation under oxidative and nonoxidative conditions and show that inhibiting MafA degradation under oxidative stress ameliorates β-cell dysfunction and could lead to novel therapies for diabetes.
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Affiliation(s)
- Ilham El Khattabi
- Section of Islet Cell and Regenerative Biology, Joslin Diabetes Center, Harvard Medical School, Boston, Massachusetts 02215, USA
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23
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Aguayo-Mazzucato C, Zavacki AM, Marinelarena A, Hollister-Lock J, El Khattabi I, Marsili A, Weir GC, Sharma A, Larsen PR, Bonner-Weir S. Thyroid hormone promotes postnatal rat pancreatic β-cell development and glucose-responsive insulin secretion through MAFA. Diabetes 2013; 62:1569-80. [PMID: 23305647 PMCID: PMC3636623 DOI: 10.2337/db12-0849] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Neonatal β cells do not secrete glucose-responsive insulin and are considered immature. We previously showed the transcription factor MAFA is key for the functional maturation of β cells, but the physiological regulators of this process are unknown. Here we show that postnatal rat β cells express thyroid hormone (TH) receptor isoforms and deiodinases in an age-dependent pattern as glucose responsiveness develops. In vivo neonatal triiodothyronine supplementation and TH inhibition, respectively, accelerated and delayed metabolic development. In vitro exposure of immature islets to triiodothyronine enhanced the expression of Mafa, the secretion of glucose-responsive insulin, and the proportion of responsive cells, all of which are effects that were abolished in the presence of dominant-negative Mafa. Using chromatin immunoprecipitation and electrophoretic mobility shift assay, we show that TH has a direct receptor-ligand interaction with the Mafa promoter and, using a luciferase reporter, that this interaction was functional. Thus, TH can be considered a physiological regulator of functional maturation of β cells via its induction of Mafa.
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Affiliation(s)
- Cristina Aguayo-Mazzucato
- Section of Islet Cell and Regenerative Biology, Joslin Diabetes Center, Harvard Medical School, Boston, Massachusetts
| | - Ann Marie Zavacki
- Thyroid Section, Division of Endocrinology, Diabetes and Hypertension, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts
| | - Alejandra Marinelarena
- Section of Islet Cell and Regenerative Biology, Joslin Diabetes Center, Harvard Medical School, Boston, Massachusetts
| | - Jennifer Hollister-Lock
- Section of Islet Cell and Regenerative Biology, Joslin Diabetes Center, Harvard Medical School, Boston, Massachusetts
| | - Ilham El Khattabi
- Section of Islet Cell and Regenerative Biology, Joslin Diabetes Center, Harvard Medical School, Boston, Massachusetts
| | - Alessandro Marsili
- Thyroid Section, Division of Endocrinology, Diabetes and Hypertension, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts
| | - Gordon C. Weir
- Section of Islet Cell and Regenerative Biology, Joslin Diabetes Center, Harvard Medical School, Boston, Massachusetts
| | - Arun Sharma
- Section of Islet Cell and Regenerative Biology, Joslin Diabetes Center, Harvard Medical School, Boston, Massachusetts
| | - P. Reed Larsen
- Thyroid Section, Division of Endocrinology, Diabetes and Hypertension, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts
| | - Susan Bonner-Weir
- Section of Islet Cell and Regenerative Biology, Joslin Diabetes Center, Harvard Medical School, Boston, Massachusetts
- Corresponding author: Susan Bonner-Weir,
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24
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Katsuta H, Aguayo-Mazzucato C, Katsuta R, Akashi T, Hollister-Lock J, Sharma AJ, Bonner-Weir S, Weir GC. Subpopulations of GFP-marked mouse pancreatic β-cells differ in size, granularity, and insulin secretion. Endocrinology 2012; 153:5180-7. [PMID: 22919061 PMCID: PMC3473214 DOI: 10.1210/en.2012-1257] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
There is growing information about the heterogeneity of pancreatic β-cells and how it relates to insulin secretion. This study used the approach of flow cytometry to sort and analyze β-cells from transgenic mice expressing green fluorescent protein (GFP) under the control of the mouse insulin I gene promoter. Three populations of β-cells with differing GFP brightness could be identified, which were classified as GFP-low, GFP-medium, and GFP-bright. The GFP-medium population comprised about 70% of the total. The GFP-low population had less insulin secretion as determined by the reverse hemolytic plaque assay and reduced insulin gene expression. Additionally, all three subpopulations of β-cells were found in mice of varying ages (embryonic d 15.5 and postnatal wk 1-9). The three populations from the youngest had larger cells (forward scatter) and less granularity (side scatter) than those from the adults. This approach opens up new ways to advance knowledge about β-cell heterogeneity.
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Affiliation(s)
- Hitoshi Katsuta
- Section on Islet Cell and Regenerative Biology, Research Division, Joslin Diabetes Center, Department of Medicine, Harvard Medical School, Boston, Massachusetts 02215, USA
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25
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Veldhuis JD, Liu PY, Takahashi PY, Keenan DM. Dynamic testosterone responses to near-physiological LH pulses are determined by the time pattern of prior intravenous LH infusion. Am J Physiol Endocrinol Metab 2012; 303:E720-8. [PMID: 22811471 PMCID: PMC3468430 DOI: 10.1152/ajpendo.00200.2012] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The long-lived glycoprotein hormone, human chorionic gonadotropin (hCG), downregulates testosterone (T) biosynthesis in vitro and in vivo in animals and humans. The degree to which short-lived pulses of pituitary luteinizing hormone (LH) do so, particularly at physiological concentrations, is not known. We test the hypothesis that continuous LH infusion compared with bolus injections of LH every 1 h or every 2 h overnight downregulates T secretory responses to a subsequent fixed template of three consecutive intravenous pulses of a physiological amount of recombinant human (rh) LH (triple stimulus). Nineteen healthy men ages 18-49 yr each underwent four separate randomly ordered overnight gonadotropin-releasing hormone-receptor antagonist treatments with superimposed intravenous infusions of saline or rhLH (1-h pulses, 2-h pulses, or continuously). Each 12-h infusion protocol was followed by the triple rhLH-pulse stimulus the next morning. During the triple stimulus, basal (nonpulsatile) as well as total (basal plus pulsatile) T secretion was higher after overnight 2- and 1-h rhLH pulses than after continuous rhLH or saline delivery. Approximate entropy, a probabilistic measure of feedforward-induced irregularity of T concentration time series, was higher after 1-h rhLH pulses than after continuous rhLH. Analytical estimation of pulsatile rhLH-T dose-response measures revealed higher T secretory sensitivity and greater rhLH potency (lower EC₅₀) after exposure to 1-h than 2-h rhLH pulses. Collectively, these data indicate that in vivo dynamics of LH-stimulated T secretion under standardized conditions in men depend on the prior time mode of LH delivery in the bloodstream.
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Affiliation(s)
- Johannes D Veldhuis
- Endocrine Research Unit, Mayo School of Graduate Medical Education, Center for Translational Science Activities, Mayo Clinic, Rochester, MN, USA.
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Aguayo-Mazzucato C, Koh A, El Khattabi I, Li WC, Toschi E, Jermendy A, Juhl K, Mao K, Weir GC, Sharma A, Bonner-Weir S. Mafa expression enhances glucose-responsive insulin secretion in neonatal rat beta cells. Diabetologia 2011; 54:583-93. [PMID: 21190012 PMCID: PMC3047400 DOI: 10.1007/s00125-010-2026-z] [Citation(s) in RCA: 129] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2010] [Accepted: 11/25/2010] [Indexed: 12/21/2022]
Abstract
AIM/HYPOTHESIS Neonatal beta cells lack glucose-stimulated insulin secretion and are thus functionally immature. We hypothesised that this lack of glucose responsiveness results from a generalised low expression of genes characteristic of mature functional beta cells. Important glucose-responsive transcription factors, Mafa and Pdx1, regulate genes involved in insulin synthesis and secretion, and have been implicated in late beta cell development. The aim of this study was to assess whether Mafa and/or Pdx1 regulates the postnatal functional maturation of beta cells. METHODS By quantitative PCR we evaluated expression of these and other beta cell genes over the first month compared with adult. After infection with adenovirus expressing MAFA, Pdx1 or green fluorescent protein (Gfp), P2 rat islets were evaluated by RT-PCR and insulin secretion with static incubation and reverse haemolytic plaque assay (RHPA). RESULTS At P2 most beta cell genes were expressed at about 10% of adult, but by P7 Pdx1 and Neurod1 no longer differ from adult; by contrast, Mafa expression remained significantly lower than adult through P21. Overexpression of Pdx1 increased Mafa, Neurod1, glucokinase (Gck) mRNA and insulin content but failed to enhance glucose responsiveness. Similar overexpression of MAFA resulted in increased Neurod1, Nkx6-1, Gck and Glp1r mRNAs and no change in insulin content but, importantly, acquisition of glucose-responsive insulin secretion. Both the percentage of secreting beta cells and the amount of insulin secreted per beta cell increased, approaching that of adult beta cells. CONCLUSIONS/INTERPRETATION In the process of functional maturation acquiring glucose-responsive insulin secretion, neonatal beta cells undergo a coordinated gene expression programme in which Mafa plays a crucial role.
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Affiliation(s)
- C. Aguayo-Mazzucato
- Section of Islet Cell and Regenerative Biology, Joslin Diabetes Center, Harvard Medical School, One Joslin Place, Boston, MA 02215, USA
| | - A. Koh
- Section of Islet Cell and Regenerative Biology, Joslin Diabetes Center, Harvard Medical School, One Joslin Place, Boston, MA 02215, USA
| | - I. El Khattabi
- Section of Islet Cell and Regenerative Biology, Joslin Diabetes Center, Harvard Medical School, One Joslin Place, Boston, MA 02215, USA
| | - W.-C. Li
- Section of Islet Cell and Regenerative Biology, Joslin Diabetes Center, Harvard Medical School, One Joslin Place, Boston, MA 02215, USA
| | - E. Toschi
- Section of Islet Cell and Regenerative Biology, Joslin Diabetes Center, Harvard Medical School, One Joslin Place, Boston, MA 02215, USA
| | - A. Jermendy
- Section of Islet Cell and Regenerative Biology, Joslin Diabetes Center, Harvard Medical School, One Joslin Place, Boston, MA 02215, USA
| | - K. Juhl
- Section of Islet Cell and Regenerative Biology, Joslin Diabetes Center, Harvard Medical School, One Joslin Place, Boston, MA 02215, USA
| | - K. Mao
- Section of Islet Cell and Regenerative Biology, Joslin Diabetes Center, Harvard Medical School, One Joslin Place, Boston, MA 02215, USA
| | - G. C. Weir
- Section of Islet Cell and Regenerative Biology, Joslin Diabetes Center, Harvard Medical School, One Joslin Place, Boston, MA 02215, USA
| | - A. Sharma
- Section of Islet Cell and Regenerative Biology, Joslin Diabetes Center, Harvard Medical School, One Joslin Place, Boston, MA 02215, USA
| | - S. Bonner-Weir
- Section of Islet Cell and Regenerative Biology, Joslin Diabetes Center, Harvard Medical School, One Joslin Place, Boston, MA 02215, USA
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Jermendy A, Toschi E, Aye T, Koh A, Aguayo-Mazzucato C, Sharma A, Weir GC, Sgroi D, Bonner-Weir S. Rat neonatal beta cells lack the specialised metabolic phenotype of mature beta cells. Diabetologia 2011; 54:594-604. [PMID: 21240476 PMCID: PMC3045081 DOI: 10.1007/s00125-010-2036-x] [Citation(s) in RCA: 104] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2010] [Accepted: 11/25/2010] [Indexed: 01/01/2023]
Abstract
AIMS/HYPOTHESIS Fetal and neonatal beta cells have poor glucose-induced insulin secretion and only gain robust glucose responsiveness several weeks after birth. We hypothesise that this unresponsiveness is due to a generalised immaturity of the metabolic pathways normally found in beta cells rather than to a specific defect. METHODS Using laser-capture microdissection we excised beta cell-enriched cores of pancreatic islets from day 1 (P1) neonatal and young adult Sprague-Dawley rats in order to compare their gene-expression profiles using Affymetrix U34A microarrays (neonatal, n = 4; adult, n = 3). RESULTS Using dChip software for analysis, 217 probe sets for genes/38 expressed sequence tags (ESTs) were significantly higher and 345 probe sets for genes/33 ESTs significantly lower in beta cell-enriched cores of neonatal islets compared with those of adult islets. Among the genes lower in the neonatal beta cells were key metabolic genes including mitochondrial shuttles (malate dehydrogenase, glycerol-3-phosphate dehydrogenase and glutamate oxalacetate transaminase), pyruvate carboxylase and carnitine palmitoyl transferase 2. Differential expression of these enzyme genes was confirmed by quantitative PCR on RNA from isolated neonatal (P2 until P28) and adult islets and with immunostaining of pancreas. Even by 28 days of age some of these genes were still expressed at lower levels than in adults. CONCLUSIONS/INTERPRETATION The lack of glucose responsiveness in neonatal islets is likely to be due to a generalised immaturity of the metabolic specialisation of pancreatic beta cells.
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Affiliation(s)
- A. Jermendy
- Section on Islet Cell and Regenerative Biology, Research Division, Joslin Diabetes Center, Department of Medicine, Harvard Medical School, One Joslin Place, Boston, MA 02215, USA; 1st Department of Pediatrics, Semmelweis University, Budapest, Hungary
| | - E. Toschi
- Section on Islet Cell and Regenerative Biology, Research Division, Joslin Diabetes Center, Department of Medicine, Harvard Medical School, One Joslin Place, Boston, MA 02215, USA
| | - T. Aye
- Section on Islet Cell and Regenerative Biology, Research Division, Joslin Diabetes Center, Department of Medicine, Harvard Medical School, One Joslin Place, Boston, MA 02215, USA
| | - A. Koh
- Section on Islet Cell and Regenerative Biology, Research Division, Joslin Diabetes Center, Department of Medicine, Harvard Medical School, One Joslin Place, Boston, MA 02215, USA
| | - C. Aguayo-Mazzucato
- Section on Islet Cell and Regenerative Biology, Research Division, Joslin Diabetes Center, Department of Medicine, Harvard Medical School, One Joslin Place, Boston, MA 02215, USA
| | - A. Sharma
- Section on Islet Cell and Regenerative Biology, Research Division, Joslin Diabetes Center, Department of Medicine, Harvard Medical School, One Joslin Place, Boston, MA 02215, USA
| | - G. C. Weir
- Section on Islet Cell and Regenerative Biology, Research Division, Joslin Diabetes Center, Department of Medicine, Harvard Medical School, One Joslin Place, Boston, MA 02215, USA
| | - D. Sgroi
- Molecular Pathology Unit, Massachusetts General Hospital, Department of Pathology, Harvard Medical School, Boston, MA, USA
| | - S. Bonner-Weir
- Section on Islet Cell and Regenerative Biology, Research Division, Joslin Diabetes Center, Department of Medicine, Harvard Medical School, One Joslin Place, Boston, MA 02215, USA
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Aye T, Toschi E, Sharma A, Sgroi D, Bonner-Weir S. Identification of markers for newly formed beta-cells in the perinatal period: a time of recognized beta-cell immaturity. J Histochem Cytochem 2010; 58:369-76. [PMID: 20051380 DOI: 10.1369/jhc.2009.954909] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Markers of beta-cell maturity would be useful in staging the differentiation of stem/progenitor cells to beta-cells whether in vivo or in vitro. We previously identified markers for newly formed beta-cells in regenerating rat pancreases after 90% partial pancreatectomy. To test the generality of these markers of newly formed beta-cells, we examined their expression during the perinatal period, a time of recognized beta-cell immaturity. We show by semiquantitative RT-PCR and immunostaining over the time course from embryonic day 18/20 to birth, 1 day, 2 days, 3 days, 7 days, and adult that MMP-2, CK-19, and SPD are truly markers of new and immature beta-cells and that their expression transiently peaks in the perinatal period and is not entirely synchronous. The shared expression of these markers among fetal, newborn, and newly regenerated beta-cells, but not adult, strongly supports their use as potential markers for new beta-cells in the assessment of both the maturity of stem cell-derived insulin-producing cells and the presence of newly formed islets (neogenesis) in the adult pancreas.
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Affiliation(s)
- Tandy Aye
- Section of Islet Transplantation and Cell Biology, Joslin Diabetes Center, Boston, Massachusetts 02215, USA
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Katsuta H, Akashi T, Katsuta R, Nagaya M, Kim D, Arinobu Y, Hara M, Bonner-Weir S, Sharma AJ, Akashi K, Weir GC. Single pancreatic beta cells co-express multiple islet hormone genes in mice. Diabetologia 2010; 53:128-138. [PMID: 19851748 PMCID: PMC2789931 DOI: 10.1007/s00125-009-1570-x] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2009] [Accepted: 09/08/2009] [Indexed: 11/24/2022]
Abstract
AIMS/HYPOTHESIS It is widely accepted that production of insulin, glucagon, somatostatin and pancreatic polypeptide in islet cells is specific to beta, alpha, delta and pancreatic polypeptide cells, respectively. We examined whether beta cells express other genes encoding islet hormones. METHODS Nested RT-PCR was performed on single beta cells of transgenic mice with green fluorescent protein (GFP) driven by mouse insulin I promoter (MIP-GFP). RESULTS Only 55% of adult beta cells expressed the insulin gene alone, while others expressed two or more islet hormone genes; 4% expressed all four hormone genes. In embryonic and neonatal cells, 60% to 80% of GFP(+) cells co-expressed pancreatic polypeptide and insulin genes in contrast to 29% in adult. To clarify cell fate, we conducted lineage tracing using rat insulin II promoter-cre mice crossed with reporter mice Gt(ROSA)26Sor-loxP-flanked STOP-cassette-GFP. All GFP(+) cells expressed insulin I and II genes, and showed similar heterogeneity of co-expression to that seen in MIP-GFP mice. Although we report expression of other hormone genes in a significant proportion of beta cells, our lineage tracing results demonstrate that after inducing InsII (also known as Ins2) expression, beta cell progenitors do not redifferentiate to non-beta cells. CONCLUSIONS/INTERPRETATION This study shows co-expression of multiple hormone genes in beta cells of adult mice as well as in embryos and neonates. This finding could: (1) represent residual expression from beta cell precursors; (2) result from alternative developmental pathways for beta cells; or (3) denote the differentiation potential of these cells. It may be linked to functional heterogeneity. This heterogeneity in gene expression may provide a means to characterise the functional, cellular and developmental heterogeneity seen in beta cells.
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Affiliation(s)
- H. Katsuta
- Section on Islet Transplantation and Cell Biology, Joslin Diabetes Center, One Joslin Place, Boston, MA 02215 USA
| | - T. Akashi
- Section on Islet Transplantation and Cell Biology, Joslin Diabetes Center, One Joslin Place, Boston, MA 02215 USA
| | - R. Katsuta
- Section on Islet Transplantation and Cell Biology, Joslin Diabetes Center, One Joslin Place, Boston, MA 02215 USA
| | - M. Nagaya
- Section on Islet Transplantation and Cell Biology, Joslin Diabetes Center, One Joslin Place, Boston, MA 02215 USA
| | - D. Kim
- Section on Islet Transplantation and Cell Biology, Joslin Diabetes Center, One Joslin Place, Boston, MA 02215 USA
| | - Y. Arinobu
- Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, Boston, MA USA
| | - M. Hara
- Department of Medicine, University of Chicago, Chicago, IL USA
| | - S. Bonner-Weir
- Section on Islet Transplantation and Cell Biology, Joslin Diabetes Center, One Joslin Place, Boston, MA 02215 USA
| | - A. J. Sharma
- Section on Islet Transplantation and Cell Biology, Joslin Diabetes Center, One Joslin Place, Boston, MA 02215 USA
| | - K. Akashi
- Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, Boston, MA USA
| | - G. C. Weir
- Section on Islet Transplantation and Cell Biology, Joslin Diabetes Center, One Joslin Place, Boston, MA 02215 USA
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Cole L, Anderson M, Antin PB, Limesand SW. One process for pancreatic beta-cell coalescence into islets involves an epithelial-mesenchymal transition. J Endocrinol 2009; 203:19-31. [PMID: 19608613 PMCID: PMC3071757 DOI: 10.1677/joe-09-0072] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Islet replacement is a promising therapy for treating diabetes mellitus, but the supply of donor tissue for transplantation is limited. To overcome this limitation, endocrine tissue can be expanded, but this requires an understanding of normal developmental processes that regulate islet formation. In this study, we compare pancreas development in sheep and human, and provide evidence that an epithelial-mesenchymal transition (EMT) is involved in beta-cell differentiation and islet formation. Transcription factors know to regulate pancreas formation, pancreatic duodenal homeobox factor 1, neurogenin 3, NKX2-2, and NKX6-1, which were expressed in the appropriate spatial and temporal pattern to coordinate pancreatic bud outgrowth and direct endocrine cell specification in sheep. Immunofluorescence staining of the developing pancreas was used to co-localize insulin and epithelial proteins (cytokeratin, E-cadherin, and beta-catenin) or insulin and a mesenchymal protein (vimentin). In sheep, individual beta-cells become insulin-positive in the progenitor epithelium, then lose epithelial characteristics, and migrate out of the epithelial layer to form islets. As beta-cells exit the epithelial progenitor cell layer, they acquire mesenchymal characteristics, shown by their acquisition of vimentin. In situ hybridization expression analysis of the SNAIL family members of transcriptional repressors (SNAIL1, -2, and -3; listed as SNAI1, -2, -3 in the HUGO Database) showed that each of the SNAIL genes was expressed in the ductal epithelium during development, and SNAIL-1 and -2 were co-expressed with insulin. Our findings provide strong evidence that the movement of beta-cells from the pancreatic ductal epithelium involves an EMT.
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Affiliation(s)
- Lori Cole
- Department of Animal Sciences, Agricultural Research Complex, University of Arizona, 1650 East Limberlost Drive, Tucson, Arizona 85719, USA
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Chen J, Jeppesen PB, Nordentoft I, Hermansen K. Stevioside Counteracts Beta-Cell Lipotoxicity without Affecting Acetyl CoA Carboxylase. Rev Diabet Stud 2007; 3:178-88. [PMID: 17487342 PMCID: PMC1828288 DOI: 10.1900/rds.2006.3.178] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Chronic exposure to high levels of free fatty acids impairs beta-cell function (lipotoxicity). Then basal insulin secretion (BIS) is increased and glucose-stimulated insulin secretion (GSIS) is inhibited. Acetyl CoA carboxylase (ACC) acts as the sensor for insulin secretion in pancreatic beta-cells in response to glucose and other nutrients. Stevioside (SVS), a diterpene glycoside, has recently been shown to prevent glucotoxic effect by regulating ACC activity. The aim of this study was to investigate whether SVS can alleviate impaired beta-cell function by regulating ACC activity. We exposed isolated rat islets and the clonal beta-cell line, INS-1E, to palmitate concentrations of 1.0 or 0.6 mM, respectively, for a period of 24 h to 120 h. The results showed that lipotoxicity occurred in rat islets after 72 h exposure to 1.0 mM palmitate. The lipotoxicity was counteracted by 10(-6) M SVS (n = 8, p < 0.001). Similar results were obtained in INS-1E cells. Neither SVS nor palmitate had any effect on the gene expression of ACC, insulin 2, and glucose transporter 2 in INS-1E cells. In contrast, palmitate significantly increased the gene expression of carnitine palmitoyl transporter 1 (n = 6, p = 0.003). However, the addition of SVS to palmitate did not counteract this effect (n = 6, p = 1.0). During lipotoxicity, SVS did not alter levels of ACC protein, phosphorylated-ACC, ACC activity or glucose uptake. Our results showed that SVS counteracts the impaired insulin secretion during lipotoxicity in rat islets as well as in INS-1E cells without affecting ACC activity.
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Affiliation(s)
- Jianguo Chen
- Address correspondence to: Jianguo Chen, e-mail:
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Liu YJ, Cheng H, Drought H, MacDonald MJ, Sharp GWG, Straub SG. Activation of the KATP channel-independent signaling pathway by the nonhydrolyzable analog of leucine, BCH. Am J Physiol Endocrinol Metab 2003; 285:E380-9. [PMID: 12709398 DOI: 10.1152/ajpendo.00008.2003] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Leucine and glutamine were used to elicit biphasic insulin release in rat pancreatic islets. Leucine did not mimic the full biphasic response of glucose. Glutamine was without effect. However, the combination of the two did mimic the biphasic response. When the ATP-sensitive K+ (KATP) channel-independent pathway was studied in the presence of diazoxide and KCl, leucine and its nonmetabolizable analog 2-aminobicyclo[2,2,1]heptane-2-carboxylic acid (BCH) both stimulated insulin secretion to a greater extent than glucose. Glutamine and dimethyl glutamate had no effect. Because the only known action of BCH is stimulation of glutamate dehydrogenase, this is sufficient to develop the full effect of the KATP channel-independent pathway. Glucose, leucine, and BCH had no effect on intracellular citrate levels. Leucine and BCH both decreased glutamate levels, whereas glucose was without effect. Glucose and leucine decreased palmitate oxidation and increased esterification. Strikingly, BCH had no effect on palmitate oxidation or esterification. Thus BCH activates the KATP channel-independent pathway of glucose signaling without raising citrate levels, without decreasing fatty acid oxidation, and without mimicking the effects of glucose and leucine on esterification. The results indicate that increased flux through the TCA cycle is sufficient to activate the KATP channel-independent pathway.
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Affiliation(s)
- Yi-Jia Liu
- Dept. of Molecular Medicine, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853-6401, USA.
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Rubí B, Antinozzi PA, Herrero L, Ishihara H, Asins G, Serra D, Wollheim CB, Maechler P, Hegardt FG. Adenovirus-mediated overexpression of liver carnitine palmitoyltransferase I in INS1E cells: effects on cell metabolism and insulin secretion. Biochem J 2002; 364:219-26. [PMID: 11988095 PMCID: PMC1222564 DOI: 10.1042/bj3640219] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Lipid metabolism in the beta-cell is critical for the regulation of insulin secretion. Pancreatic beta-cells chronically exposed to fatty acids show higher carnitine palmitoyltransferase I (CPT I) protein levels, higher palmitate oxidation rates and an altered insulin response to glucose. We examined the effect of increasing CPT I levels on insulin secretion in cultured beta-cells. We prepared a recombinant adenovirus containing the cDNA for the rat liver isoform of CPT I. The overexpression of CPT I in INS1E cells caused a more than a 5-fold increase in the levels of CPT I protein (detected by Western blotting), a 6-fold increase in the CPT activity, and an increase in fatty acid oxidation at 2.5 mM glucose (1.7-fold) and 15 mM glucose (3.1-fold). Insulin secretion was stimulated in control cells by 15 mM glucose or 30 mM KCl. INS1E cells overexpressing CPT I showed lower insulin secretion on stimulation with 15 mM glucose (-40%; P<0.05). This decrease depended on CPT I activity, since the presence of etomoxir, a specific inhibitor of CPT I, in the preincubation medium normalized the CPT I activity, the fatty-acid oxidation rate and the insulin secretion in response to glucose. Exogenous palmitate (0.25 mM) rescued glucose-stimulated insulin secretion (GSIS) in CPT I-overexpressing cells, indicating that the mechanism of impaired GSIS was through the depletion of a critical lipid. Depolarizing the cells with KCl or intermediary glucose concentrations (7.5 mM) elicited similar insulin secretion in control cells and cells overexpressing CPT I. Glucose-induced ATP increase, glucose metabolism and the triacylglycerol content remained unchanged. These results provide further evidence that CPT I activity regulates insulin secretion in the beta-cell. They also indicate that up-regulation of CPT I contributes to the loss of response to high glucose in beta-cells exposed to fatty acids.
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Affiliation(s)
- Blanca Rubí
- Department of Biochemistry and Molecular Biology, University of Barcelona, School of Pharmacy, Diagonal 643, E-08028 Barcelona, Spain
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Hughes SJ. The role of reduced glucose transporter content and glucose metabolism in the immature secretory responses of fetal rat pancreatic islets. Diabetologia 1994; 37:134-40. [PMID: 8163046 DOI: 10.1007/s001250050083] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Isolated fetal islets show an immature or poor secretory response to nutrient secretagogues which may result from impaired mitochondrial oxidative processes. Insulin secretion, glucose metabolism and detection of metabolic enzymes by radiolabelling and immunoprecipitation were compared in islets isolated from neonatal (aged 5 days) and fetal rats (at 20 days gestation). The insulin secretory dynamics of fetal islets were abnormal in response to stimulation by glucose (10 mmol/l); a rapid release of insulin reaching a maximum 6 min after stimulation was observed with no rising second phase release. However, when the data were expressed as percentage of islet insulin content released, fetal islets released significantly more insulin than neonatal islets in response to glucose (4.86 +/- 0.45% vs 1.81 +/- 0.62%, p < 0.01) or 100 nmol/l glibenclamide (2.49 +/- 0.17% vs 0.25 +/- 0.06%, p < 0.001). Fetal islets however, failed to release insulin in response to stimulation by glyceraldehyde (10 mmol/l) unlike neonatal islets. Both glucose utilisation (as measured by the formation of [3H] H2O from 5-[3H] glucose) and glucose oxidation (as measured by the formation of [14C] CO2 from U-[14C] glucose) did not increase significantly in response to increasing the medium glucose concentration to 10 mmol/l whereas in neonatal islets, glucose utilisation and glucose oxidation were significantly increased 2.5- and 2.7-fold, respectively. When islets were incubated with both radiolabelled glucoses simultaneously, the rate of glucose oxidation was shown to be directly proportional to the rate of glucose utilisation. The relationship between glucose utilisation and glucose oxidation was similar in fetal and neonatal islets.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- S J Hughes
- Division of Basic Medical Science, St. Mary's Hospital Medical School, Imperial College, London, UK
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35
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Zhou YP, Grill VE. Long-term exposure of rat pancreatic islets to fatty acids inhibits glucose-induced insulin secretion and biosynthesis through a glucose fatty acid cycle. J Clin Invest 1994; 93:870-6. [PMID: 8113418 PMCID: PMC293952 DOI: 10.1172/jci117042] [Citation(s) in RCA: 500] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
UNLABELLED We tested effects of long-term exposure of pancreatic islets to free fatty acids (FFA) in vitro on B cell function. Islets isolated from male Sprague-Dawley rats were exposed to palmitate (0.125 or 0.25 mM), oleate (0.125 mM), or octanoate (2.0 mM) during culture. Insulin responses were subsequently tested in the absence of FFA. After a 48-h exposure to FFA, insulin secretion during basal glucose (3.3 mM) was several-fold increased. However, during stimulation with 27 mM glucose, secretion was inhibited by 30-50% and proinsulin biosynthesis by 30-40%. Total protein synthesis was similarly affected. Conversely, previous palmitate did not impair alpha-ketoisocaproic acid (5 mM)-induced insulin release. Induction and reversibility of the inhibitory effect on glucose-induced insulin secretion required between 6 and 24 h. Addition of the carnitine palmitoyltransferase I inhibitor etomoxir (1 microM) partially reversed (by > 50%) FFA-associated decrease in secretory as well as proinsulin biosynthetic responses to 27 mM glucose. The inhibitory effect of previous palmitate was similar when co-culture was performed with 5.5, 11, or 27 mM glucose. Exposure to palmitate or oleate reduced the production of 14CO2 from D-[U-14C]glucose, and of 14CO2 from D-[3,4-14C]-glucose, both effects being reversed by etomoxir. CONCLUSIONS long-term exposure to FFA inhibits glucose-induced insulin secretion and biosynthesis probably through a glucose fatty acid cycle.
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Affiliation(s)
- Y P Zhou
- Department of Endocrinology, Karolinska Hospital, Karolinska Institute, Stockholm, Sweden
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