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Parveen N, Dhawan S. DNA Methylation Patterning and the Regulation of Beta Cell Homeostasis. Front Endocrinol (Lausanne) 2021; 12:651258. [PMID: 34025578 PMCID: PMC8137853 DOI: 10.3389/fendo.2021.651258] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2021] [Accepted: 04/21/2021] [Indexed: 12/14/2022] Open
Abstract
Pancreatic beta cells play a central role in regulating glucose homeostasis by secreting the hormone insulin. Failure of beta cells due to reduced function and mass and the resulting insulin insufficiency can drive the dysregulation of glycemic control, causing diabetes. Epigenetic regulation by DNA methylation is central to shaping the gene expression patterns that define the fully functional beta cell phenotype and regulate beta cell growth. Establishment of stage-specific DNA methylation guides beta cell differentiation during fetal development, while faithful restoration of these signatures during DNA replication ensures the maintenance of beta cell identity and function in postnatal life. Lineage-specific transcription factor networks interact with methylated DNA at specific genomic regions to enhance the regulatory specificity and ensure the stability of gene expression patterns. Recent genome-wide DNA methylation profiling studies comparing islets from diabetic and non-diabetic human subjects demonstrate the perturbation of beta cell DNA methylation patterns, corresponding to the dysregulation of gene expression associated with mature beta cell state in diabetes. This article will discuss the molecular underpinnings of shaping the islet DNA methylation landscape, its mechanistic role in the specification and maintenance of the functional beta cell phenotype, and its dysregulation in diabetes. We will also review recent advances in utilizing beta cell specific DNA methylation patterns for the development of biomarkers for diabetes, and targeting DNA methylation to develop translational approaches for supplementing the functional beta cell mass deficit in diabetes.
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Affiliation(s)
| | - Sangeeta Dhawan
- Department of Translational Research and Cellular Therapeutics, Arthur Riggs Diabetes and Metabolism Research Institute, City of Hope, Duarte, CA, United States
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2
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Henquin JC. Glucose-induced insulin secretion in isolated human islets: Does it truly reflect β-cell function in vivo? Mol Metab 2021; 48:101212. [PMID: 33737253 PMCID: PMC8065218 DOI: 10.1016/j.molmet.2021.101212] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 03/03/2021] [Accepted: 03/09/2021] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Diabetes always involves variable degrees of β-cell demise and malfunction leading to insufficient insulin secretion. Besides clinical investigations, many research projects used rodent islets to study various facets of β-cell pathophysiology. Their important contributions laid the foundations of steadily increasing numbers of experimental studies resorting to isolated human islets. SCOPE OF REVIEW This review, based on an analysis of data published over 60 years of clinical investigations and results of more recent studies in isolated islets, addresses a question of translational nature. Does the information obtained in vitro with human islets fit with our knowledge of insulin secretion in man? The aims are not to discuss specificities of pathways controlling secretion but to compare qualitative and quantitative features of glucose-induced insulin secretion in isolated human islets and in living human subjects. MAJOR CONCLUSIONS Much of the information gathered in vitro can reliably be translated to the in vivo situation. There is a fairly good, though not complete, qualitative and quantitative coherence between insulin secretion rates measured in vivo and in vitro during stimulation with physiological glucose concentrations, but the concordance fades out under extreme conditions. Perplexing discrepancies also exist between insulin secretion in subjects with Type 2 diabetes and their islets studied in vitro, in particular concerning the kinetics. Future projects should ascertain that the experimental conditions are close to physiological and do not alter the function of normal and diabetic islets.
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Affiliation(s)
- Jean-Claude Henquin
- Unit of Endocrinology and Metabolism, Faculty of Medicine, University of Louvain, Brussels, Belgium.
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Zammit NW, Seeberger KL, Zamerli J, Walters SN, Lisowski L, Korbutt GS, Grey ST. Selection of a novel AAV2/TNFAIP3 vector for local suppression of islet xenograft inflammation. Xenotransplantation 2020; 28:e12669. [PMID: 33316848 DOI: 10.1111/xen.12669] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 08/24/2020] [Accepted: 11/26/2020] [Indexed: 12/16/2022]
Abstract
BACKGROUND Neonatal porcine islets (NPIs) can restore glucose control in mice, pigs, and non-human primates, representing a potential abundant alternative islet supply for clinical beta cell replacement therapy. However, NPIs are vulnerable to inflammatory insults that could be overcome with genetic modifications. Here, we demonstrate in a series of proof-of-concept experiments the potential of the cytoplasmic ubiquitin-editing protein A20, encoded by the TNFAIP3 gene, as an NPI cytoprotective gene. METHODS We forced A20 expression in NPI grafts using a recombinant adenovirus 5 (Ad5) vector and looked for impact on TNF-stimulated NF-κB activation and NPI graft function. As adeno-associated vectors (AAV) are clinically preferred vectors but exhibit poor transduction efficacy in NPIs, we next screened a series of AAV serotypes under different transduction protocols for their ability achieve high transduction efficiency and suppress NPI inflammation without impacting NPI maturation. RESULTS Forcing the expression of A20 in NPI with Ad5 vector blocked NF-κB activation by inhibiting IκBα phosphorylation and degradation, and reduced the induction of pro-inflammatory genes Cxcl10 and Icam1. A20-expressing NPIs also exhibited superior functional capacity when transplanted into diabetic immunodeficient recipient mice, evidenced by a more rapid return to euglycemia and improved GTT compared to unmodified NPI grafts. We found AAV2 combined with a 14-day culture period maximized NPI transduction efficiency (>70% transduction rate), and suppressed NF-κB-dependent gene expression without adverse impact upon NPI maturation. CONCLUSION We report a new protocol that allows for high-efficiency genetic modification of NPIs, which can be utilized to introduce candidate genes without the need for germline engineering. This approach would be suitable for preclinical and clinical testing of beneficial molecules. We also report for the first time that A20 is cytoprotective for NPI, such that A20 gene therapy could aid the clinical development of NPIs for beta cell replacement.
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Affiliation(s)
- Nathan W Zammit
- Immunology Department, Garvan Institute of Medical Research, Darlinghurst, NSW, Australia.,St Vincent's Clinical School, Faculty of Medicine, University of New South Wales Sydney, Sydney, NSW, Australia
| | | | - Jad Zamerli
- Immunology Department, Garvan Institute of Medical Research, Darlinghurst, NSW, Australia
| | - Stacey N Walters
- Immunology Department, Garvan Institute of Medical Research, Darlinghurst, NSW, Australia
| | - Leszek Lisowski
- Translational Vectorology Unit, Children's Medical Research Institute, The University of Sydney, Westmead, NSW, Australia.,Military Institute of Medicine, Laboratory of Molecular Oncology and Innovative Therapies, Warsaw, Poland
| | | | - Shane T Grey
- Immunology Department, Garvan Institute of Medical Research, Darlinghurst, NSW, Australia.,St Vincent's Clinical School, Faculty of Medicine, University of New South Wales Sydney, Sydney, NSW, Australia
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Zammit NW, Walters SN, Seeberger KL, O'Connell PJ, Korbutt GS, Grey ST. A20 as an immune tolerance factor can determine islet transplant outcomes. JCI Insight 2019; 4:131028. [PMID: 31581152 DOI: 10.1172/jci.insight.131028] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Accepted: 09/25/2019] [Indexed: 01/05/2023] Open
Abstract
Islet transplantation can restore lost glycemic control in type 1 diabetes subjects but is restricted in its clinical application by a limiting supply of islets and the need for heavy immune suppression to prevent rejection. TNFAIP3, encoding the ubiquitin editing enzyme A20, regulates the activation of immune cells by raising NF-κB signaling thresholds. Here, we show that increasing A20 expression in allogeneic islet grafts resulted in permanent survival for ~45% of recipients, and > 80% survival when combined with subtherapeutic rapamycin. Allograft survival was dependent upon Tregs and was antigen specific, and grafts showed reduced expression of inflammatory factors. Transplantation of islets with A20 containing a loss-of-function variant (I325N) resulted in increased RIPK1 ubiquitination and NF-κB signaling, graft hyperinflammation, and acute allograft rejection. Overexpression of A20 in human islets potently reduced expression of inflammatory mediators, with no impact on glucose-stimulated insulin secretion. Therapeutic administration of A20 raises inflammatory signaling thresholds to favor immune tolerance and promotes islet allogeneic survival. Clinically, this would allow for reduced immunosuppression and support the use of alternate islet sources.
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Affiliation(s)
- Nathan W Zammit
- Immunology Department, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia
| | - Stacey N Walters
- Immunology Department, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia
| | - Karen L Seeberger
- Department of Surgery, University of Alberta, Edmonton, Alberta, Canada
| | - Philip J O'Connell
- Centre for Transplant and Renal Research, Westmead Institute for Medical Research, University of Sydney at Westmead Hospital, NSW Australia
| | - Gregory S Korbutt
- Department of Surgery, University of Alberta, Edmonton, Alberta, Canada
| | - Shane T Grey
- Immunology Department, Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia
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5
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Functional Maturation and In Vitro Differentiation of Neonatal Porcine Islet Grafts. Transplantation 2018; 102:e413-e423. [DOI: 10.1097/tp.0000000000002354] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Henquin JC, Nenquin M. Dynamics and Regulation of Insulin Secretion in Pancreatic Islets from Normal Young Children. PLoS One 2016; 11:e0165961. [PMID: 27806105 PMCID: PMC5091846 DOI: 10.1371/journal.pone.0165961] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Accepted: 10/20/2016] [Indexed: 11/30/2022] Open
Abstract
Insulin secretion has only exceptionally been investigated in pancreatic islets from healthy young children. It remains unclear whether those islets behave like adult islets despite substantial differences in cellular composition and higher β-cell replication rates. Islets were isolated from 5 infants/toddlers (11–36 month-old) and perifused to characterize their dynamics of insulin secretion when subjected to various stimuli and inhibitors. Their insulin responses were compared to those previously reported for similarly treated adult islets. Qualitatively, infant islets responded like adult islets to stimulation by glucose, tolbutamide, forskolin (to increase cAMP), arginine and the combination of leucine and glutamine, and to inhibition by diazoxide and CaCl2 omission. This similarity included the concentration-dependency and biphasic pattern of glucose-induced insulin secretion, the dynamics of the responses to non-glucose stimuli and metabolic amplification of these responses. The insulin content was not different, but fractional insulin secretion rates were lower in infant than adult islets irrespective of the stimulus. However, the stimulation index was similar because basal secretion rates were also lower in infant islets. In conclusion, human β-cells are functionally mature by the age of one year, before expansion of their mass is complete. Their responsiveness (stimulation index) to all stimuli is not smaller than that of adult β-cells. Yet, under basal and stimulated conditions, they secrete smaller proportions of their insulin stores in keeping with smaller in vivo insulin needs during infancy.
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Affiliation(s)
- Jean-Claude Henquin
- Unit of Endocrinology and Metabolism, Faculty of Medicine, University of Louvain, Brussels, Belgium
- * E-mail:
| | - Myriam Nenquin
- Unit of Endocrinology and Metabolism, Faculty of Medicine, University of Louvain, Brussels, Belgium
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7
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Beamish CA, Strutt BJ, Arany EJ, Hill DJ. Insulin-positive, Glut2-low cells present within mouse pancreas exhibit lineage plasticity and are enriched within extra-islet endocrine cell clusters. Islets 2016; 8:65-82. [PMID: 27010375 PMCID: PMC4987018 DOI: 10.1080/19382014.2016.1162367] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Revised: 02/25/2016] [Accepted: 03/01/2016] [Indexed: 01/01/2023] Open
Abstract
Regeneration of insulin-producing β-cells from resident pancreas progenitors requires an understanding of both progenitor identity and lineage plasticity. One model suggested that a rare β-cell sub-population within islets demonstrated multi-lineage plasticity. We hypothesized that β-cells from young mice (postnatal day 7, P7) exhibit such plasticity and used a model of islet dedifferentiation toward a ductal epithelial-cell phenotype to test this theory. RIPCre;Z/AP(+/+) mice were used to lineage trace the fate of β-cells during dedifferentiation culture by a human placental alkaline phosphatase (HPAP) reporter. There was a significant loss of HPAP-expressing β-cells in culture, but remaining HPAP(+) cells lost insulin expression while gaining expression of the epithelial duct cell marker cytokeratin-19 (Ck19). Flow cytometry and recovery of β-cell subpopulations from whole pancreas vs. islets suggest that the HPAP(+)Ck19(+) cells had derived from insulin-positive, glucose-transporter-2-low (Ins(+)Glut2(LO)) cells, representing 3.5% of all insulin-expressing cells. The majority of these cells were found outside of islets within clusters of <5 β-cells. These insulin(+)Glut2(LO) cells demonstrated a greater proliferation rate in vivo and in vitro as compared to insulin(+)Glut2(+) cells at P7, were retained into adulthood, and a subset differentiated into endocrine, ductal, and neural lineages, illustrating substantial plasticity. Results were confirmed using RIPCre;ROSA- eYFP mice. Quantitative PCR data indicated these cells possess an immature β-cell phenotype. These Ins(+)Glut2(LO) cells may represent a resident population of cells capable of forming new, functional β-cells, and which may be potentially exploited for regenerative therapies in the future.
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Affiliation(s)
- Christine A. Beamish
- Department of Physiology and Pharmacology, Western University, London, ON, Canada
- Children's Health Research Institute, London, ON, Canada
- Lawson Health Research Institute, St Joseph Health Care, London, ON, Canada
| | - Brenda J. Strutt
- Department of Medicine, Western University, London, ON, Canada
- Lawson Health Research Institute, St Joseph Health Care, London, ON, Canada
| | - Edith J. Arany
- Department of Medicine, Western University, London, ON, Canada
- Department of Pathology, Western University, London, ON, Canada
- Children's Health Research Institute, London, ON, Canada
- Lawson Health Research Institute, St Joseph Health Care, London, ON, Canada
| | - David J. Hill
- Department of Physiology and Pharmacology, Western University, London, ON, Canada
- Department of Medicine, Western University, London, ON, Canada
- Children's Health Research Institute, London, ON, Canada
- Lawson Health Research Institute, St Joseph Health Care, London, ON, Canada
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Wills QF, Boothe T, Asadi A, Ao Z, Warnock GL, Kieffer TJ, Johnson JD. Statistical approaches and software for clustering islet cell functional heterogeneity. Islets 2016; 8:48-56. [PMID: 26909740 PMCID: PMC4878268 DOI: 10.1080/19382014.2016.1150664] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Worldwide efforts are underway to replace or repair lost or dysfunctional pancreatic β-cells to cure diabetes. However, it is unclear what the final product of these efforts should be, as β-cells are thought to be heterogeneous. To enable the analysis of β-cell heterogeneity in an unbiased and quantitative way, we developed model-free and model-based statistical clustering approaches, and created new software called TraceCluster. Using an example data set, we illustrate the utility of these approaches by clustering dynamic intracellular Ca(2+) responses to high glucose in ∼300 simultaneously imaged single islet cells. Using feature extraction from the Ca(2+) traces on this reference data set, we identified 2 distinct populations of cells with β-like responses to glucose. To the best of our knowledge, this report represents the first unbiased cluster-based analysis of human β-cell functional heterogeneity of simultaneous recordings. We hope that the approaches and tools described here will be helpful for those studying heterogeneity in primary islet cells, as well as excitable cells derived from embryonic stem cells or induced pluripotent cells.
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Affiliation(s)
- Quin F Wills
- a Wellcome Trust Center for Human Genetics, University of Oxford , Oxford , United Kingdom
- b Weatherall Institute of Molecular Medicine, University of Oxford , Oxford , United Kingdom
| | - Tobias Boothe
- c Department of Cellular and Physiological Sciences , Life Sciences Center, University of British Columbia , Vancouver , Canada
| | - Ali Asadi
- c Department of Cellular and Physiological Sciences , Life Sciences Center, University of British Columbia , Vancouver , Canada
| | - Ziliang Ao
- d Department of Surgery , University of British Columbia , Vancouver , Canada
| | - Garth L Warnock
- d Department of Surgery , University of British Columbia , Vancouver , Canada
| | - Timothy J Kieffer
- c Department of Cellular and Physiological Sciences , Life Sciences Center, University of British Columbia , Vancouver , Canada
- d Department of Surgery , University of British Columbia , Vancouver , Canada
| | - James D Johnson
- c Department of Cellular and Physiological Sciences , Life Sciences Center, University of British Columbia , Vancouver , Canada
- d Department of Surgery , University of British Columbia , Vancouver , Canada
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Lyon J, Manning Fox JE, Spigelman AF, Kim R, Smith N, O'Gorman D, Kin T, Shapiro AMJ, Rajotte RV, MacDonald PE. Research-Focused Isolation of Human Islets From Donors With and Without Diabetes at the Alberta Diabetes Institute IsletCore. Endocrinology 2016; 157:560-9. [PMID: 26653569 DOI: 10.1210/en.2015-1562] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Recent years have seen an increased focus on human islet biology, and exciting findings in the stem cell and genomic arenas highlight the need to define the key features of mature human islets and β-cells. Donor and organ procurement parameters impact human islet yield, although for research purposes islet yield may be secondary in importance to islet function. We examined the feasibility of a research-only human islet isolation, distribution, and biobanking program and whether key criteria such as cold ischemia time (CIT) and metabolic status may be relaxed and still allow successful research-focused isolations, including from donors with type 1 diabetes and type 2 diabetes. Through 142 isolations over approximately 5 years, we confirm that CIT and glycated hemoglobin each have a weak negative impacts on isolation purity and yield, and extending CIT beyond the typical clinical isolation cutoff of 12 hours (to ≥ 18 h) had only a modest impact on islet function. Age and glycated hemoglobin/type 2 diabetes status negatively impacted secretory function; however, these and other biological (sex, body mass index) and procurement/isolation variables (CIT, time in culture) appear to make only a small contribution to the heterogeneity of human islet function. This work demonstrates the feasibility of extending acceptable CIT for research-focused human islet isolation and highlights the biological variation in function of human islets from donors with and without diabetes.
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Affiliation(s)
- James Lyon
- Alberta Diabetes Institute IsletCore (J.L., J.E.M.F., P.E.M.) and Departments of Pharmacology (J.E.M.F., A.F.S., R.K., N.S., P.E.M.) and Surgery (D.O., T.K., A.M.J.S., R.V.R.), University of Alberta, Edmonton, Canada T6G 2E1
| | - Jocelyn E Manning Fox
- Alberta Diabetes Institute IsletCore (J.L., J.E.M.F., P.E.M.) and Departments of Pharmacology (J.E.M.F., A.F.S., R.K., N.S., P.E.M.) and Surgery (D.O., T.K., A.M.J.S., R.V.R.), University of Alberta, Edmonton, Canada T6G 2E1
| | - Aliya F Spigelman
- Alberta Diabetes Institute IsletCore (J.L., J.E.M.F., P.E.M.) and Departments of Pharmacology (J.E.M.F., A.F.S., R.K., N.S., P.E.M.) and Surgery (D.O., T.K., A.M.J.S., R.V.R.), University of Alberta, Edmonton, Canada T6G 2E1
| | - Ryekjang Kim
- Alberta Diabetes Institute IsletCore (J.L., J.E.M.F., P.E.M.) and Departments of Pharmacology (J.E.M.F., A.F.S., R.K., N.S., P.E.M.) and Surgery (D.O., T.K., A.M.J.S., R.V.R.), University of Alberta, Edmonton, Canada T6G 2E1
| | - Nancy Smith
- Alberta Diabetes Institute IsletCore (J.L., J.E.M.F., P.E.M.) and Departments of Pharmacology (J.E.M.F., A.F.S., R.K., N.S., P.E.M.) and Surgery (D.O., T.K., A.M.J.S., R.V.R.), University of Alberta, Edmonton, Canada T6G 2E1
| | - Doug O'Gorman
- Alberta Diabetes Institute IsletCore (J.L., J.E.M.F., P.E.M.) and Departments of Pharmacology (J.E.M.F., A.F.S., R.K., N.S., P.E.M.) and Surgery (D.O., T.K., A.M.J.S., R.V.R.), University of Alberta, Edmonton, Canada T6G 2E1
| | - Tatsuya Kin
- Alberta Diabetes Institute IsletCore (J.L., J.E.M.F., P.E.M.) and Departments of Pharmacology (J.E.M.F., A.F.S., R.K., N.S., P.E.M.) and Surgery (D.O., T.K., A.M.J.S., R.V.R.), University of Alberta, Edmonton, Canada T6G 2E1
| | - A M James Shapiro
- Alberta Diabetes Institute IsletCore (J.L., J.E.M.F., P.E.M.) and Departments of Pharmacology (J.E.M.F., A.F.S., R.K., N.S., P.E.M.) and Surgery (D.O., T.K., A.M.J.S., R.V.R.), University of Alberta, Edmonton, Canada T6G 2E1
| | - Raymond V Rajotte
- Alberta Diabetes Institute IsletCore (J.L., J.E.M.F., P.E.M.) and Departments of Pharmacology (J.E.M.F., A.F.S., R.K., N.S., P.E.M.) and Surgery (D.O., T.K., A.M.J.S., R.V.R.), University of Alberta, Edmonton, Canada T6G 2E1
| | - Patrick E MacDonald
- Alberta Diabetes Institute IsletCore (J.L., J.E.M.F., P.E.M.) and Departments of Pharmacology (J.E.M.F., A.F.S., R.K., N.S., P.E.M.) and Surgery (D.O., T.K., A.M.J.S., R.V.R.), University of Alberta, Edmonton, Canada T6G 2E1
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Ferdaoussi M, Dai X, Jensen MV, Wang R, Peterson BS, Huang C, Ilkayeva O, Smith N, Miller N, Hajmrle C, Spigelman AF, Wright RC, Plummer G, Suzuki K, Mackay JP, van de Bunt M, Gloyn AL, Ryan TE, Norquay LD, Brosnan MJ, Trimmer JK, Rolph TP, Kibbey RG, Manning Fox JE, Colmers WF, Shirihai OS, Neufer PD, Yeh ETH, Newgard CB, MacDonald PE. Isocitrate-to-SENP1 signaling amplifies insulin secretion and rescues dysfunctional β cells. J Clin Invest 2015; 125:3847-60. [PMID: 26389676 DOI: 10.1172/jci82498] [Citation(s) in RCA: 133] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Accepted: 07/24/2015] [Indexed: 01/02/2023] Open
Abstract
Insulin secretion from β cells of the pancreatic islets of Langerhans controls metabolic homeostasis and is impaired in individuals with type 2 diabetes (T2D). Increases in blood glucose trigger insulin release by closing ATP-sensitive K+ channels, depolarizing β cells, and opening voltage-dependent Ca2+ channels to elicit insulin exocytosis. However, one or more additional pathway(s) amplify the secretory response, likely at the distal exocytotic site. The mitochondrial export of isocitrate and engagement with cytosolic isocitrate dehydrogenase (ICDc) may be one key pathway, but the mechanism linking this to insulin secretion and its role in T2D have not been defined. Here, we show that the ICDc-dependent generation of NADPH and subsequent glutathione (GSH) reduction contribute to the amplification of insulin exocytosis via sentrin/SUMO-specific protease-1 (SENP1). In human T2D and an in vitro model of human islet dysfunction, the glucose-dependent amplification of exocytosis was impaired and could be rescued by introduction of signaling intermediates from this pathway. Moreover, islet-specific Senp1 deletion in mice caused impaired glucose tolerance by reducing the amplification of insulin exocytosis. Together, our results identify a pathway that links glucose metabolism to the amplification of insulin secretion and demonstrate that restoration of this axis rescues β cell function in T2D.
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11
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Postnatal β-cell maturation is associated with islet-specific microRNA changes induced by nutrient shifts at weaning. Nat Commun 2015; 6:8084. [PMID: 26330140 PMCID: PMC4569696 DOI: 10.1038/ncomms9084] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Accepted: 07/16/2015] [Indexed: 12/21/2022] Open
Abstract
Glucose-induced insulin secretion is an essential function of pancreatic β-cells that is partially lost in individuals affected by Type 2 diabetes. This unique property of β-cells is acquired through a poorly understood postnatal maturation process involving major modifications in gene expression programs. Here we show that β-cell maturation is associated with changes in microRNA expression induced by the nutritional transition that occurs at weaning. When mimicked in newborn islet cells, modifications in the level of specific microRNAs result in a switch in the expression of metabolic enzymes and cause the acquisition of glucose-induced insulin release. Our data suggest microRNAs have a central role in postnatal β-cell maturation and in the determination of adult functional β-cell mass. A better understanding of the events governing β-cell maturation may help understand why some individuals are predisposed to developing diabetes and could lead to new strategies for the treatment of this common metabolic disease. Pancreatic β-cells are less responsive to changes in glucose concentration in newborn than in adult rats. Here, the authors show that functional β-cell maturation is associated with changes in miRNA expression induced by nutritional shifts at the suckling-to-weaning transition.
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Manning Fox JE, Lyon J, Dai XQ, Wright RC, Hayward J, van de Bunt M, Kin T, Shapiro AMJ, McCarthy MI, Gloyn AL, Ungrin MD, Lakey JR, Kneteman NM, Warnock GL, Korbutt GS, Rajotte RV, MacDonald PE. Human islet function following 20 years of cryogenic biobanking. Diabetologia 2015; 58:1503-12. [PMID: 25930156 PMCID: PMC4472956 DOI: 10.1007/s00125-015-3598-4] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Accepted: 04/07/2015] [Indexed: 02/07/2023]
Abstract
AIMS/HYPOTHESIS There are potential advantages to the low-temperature (-196 °C) banking of isolated islets, including the maintenance of viable islets for future research. We therefore assessed the in vitro and in vivo function of islets cryopreserved for nearly 20 years. METHODS Human islets were cryopreserved from 1991 to 2001 and thawed between 2012 and 2014. These were characterised by immunostaining, patch-clamp electrophysiology, insulin secretion, transcriptome analysis and transplantation into a streptozotocin (STZ)-induced mouse model of diabetes. RESULTS The cryopreservation time was 17.6 ± 0.4 years (n = 43). The thawed islets stained positive with dithizone, contained insulin-positive and glucagon-positive cells, and displayed levels of apoptosis and transcriptome profiles similar to those of freshly isolated islets, although their insulin content was lower. The cryopreserved beta cells possessed ion channels and exocytotic responses identical to those of freshly isolated beta cells. Cells from a subset of five donors demonstrated similar perifusion insulin secretion profiles pre- and post-cryopreservation. The transplantation of cryopreserved islets into the diabetic mice improved their glucose tolerance but did not completely normalise their blood glucose levels. Circulating human insulin and insulin-positive grafts were detectable at 10 weeks post-transplantation. CONCLUSIONS/INTERPRETATION We have demonstrated the potential for long-term banking of human islets for research, which could enable the use of tissue from a large number of donors with future technologies to gain new insight into diabetes.
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Affiliation(s)
- Jocelyn E. Manning Fox
- Alberta Diabetes Institute, University of Alberta, LKS Centre, Edmonton, AB Canada T6G 2R3
- Department of Pharmacology, University of Alberta, Edmonton, Canada
| | - James Lyon
- Alberta Diabetes Institute, University of Alberta, LKS Centre, Edmonton, AB Canada T6G 2R3
- Department of Pharmacology, University of Alberta, Edmonton, Canada
| | - Xiao Qing Dai
- Alberta Diabetes Institute, University of Alberta, LKS Centre, Edmonton, AB Canada T6G 2R3
- Department of Pharmacology, University of Alberta, Edmonton, Canada
| | - Robert C. Wright
- Alberta Diabetes Institute, University of Alberta, LKS Centre, Edmonton, AB Canada T6G 2R3
- Department of Pharmacology, University of Alberta, Edmonton, Canada
| | - Julie Hayward
- Alberta Diabetes Institute, University of Alberta, LKS Centre, Edmonton, AB Canada T6G 2R3
- Department of Surgery, University of Alberta, Edmonton, Canada
| | - Martijn van de Bunt
- Oxford Centre for Diabetes, Endocrinology, and Metabolism, University of Oxford, Oxford, UK
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Tatsuya Kin
- Alberta Diabetes Institute, University of Alberta, LKS Centre, Edmonton, AB Canada T6G 2R3
- Department of Surgery, University of Alberta, Edmonton, Canada
| | - A. M. James Shapiro
- Alberta Diabetes Institute, University of Alberta, LKS Centre, Edmonton, AB Canada T6G 2R3
- Department of Surgery, University of Alberta, Edmonton, Canada
| | - Mark I. McCarthy
- Oxford Centre for Diabetes, Endocrinology, and Metabolism, University of Oxford, Oxford, UK
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
- Oxford NIHR Biomedical Research Centre, Churchill Hospital, Oxford, UK
| | - Anna L. Gloyn
- Oxford Centre for Diabetes, Endocrinology, and Metabolism, University of Oxford, Oxford, UK
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, UK
- Oxford NIHR Biomedical Research Centre, Churchill Hospital, Oxford, UK
| | - Mark D. Ungrin
- Faculty of Veterinary Medicine, University of Calgary, Calgary, Canada
| | - Jonathan R. Lakey
- Departments of Surgery and Biomedical Engineering, University of California, Irvine, USA
| | | | - Garth L. Warnock
- Department of Surgery, University of British Columbia, Vancouver, Canada
| | - Gregory S. Korbutt
- Alberta Diabetes Institute, University of Alberta, LKS Centre, Edmonton, AB Canada T6G 2R3
- Department of Surgery, University of Alberta, Edmonton, Canada
| | - Raymond V. Rajotte
- Alberta Diabetes Institute, University of Alberta, LKS Centre, Edmonton, AB Canada T6G 2R3
- Department of Surgery, Surgical Medical Research Institute, HMRC, University of Alberta, Edmonton, AB Canada T6G 2S2
| | - Patrick E. MacDonald
- Alberta Diabetes Institute, University of Alberta, LKS Centre, Edmonton, AB Canada T6G 2R3
- Department of Pharmacology, University of Alberta, Edmonton, Canada
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Dolenšek J, Rupnik MS, Stožer A. Structural similarities and differences between the human and the mouse pancreas. Islets 2015; 7:e1024405. [PMID: 26030186 PMCID: PMC4589993 DOI: 10.1080/19382014.2015.1024405] [Citation(s) in RCA: 191] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Revised: 02/20/2015] [Accepted: 02/23/2015] [Indexed: 02/08/2023] Open
Abstract
Mice remain the most studied animal model in pancreas research. Since the findings of this research are typically extrapolated to humans, it is important to understand both similarities and differences between the 2 species. Beside the apparent difference in size and macroscopic organization of the organ in the 2 species, there are a number of less evident and only recently described differences in organization of the acinar and ductal exocrine tissue, as well as in the distribution, composition, and architecture of the endocrine islets of Langerhans. Furthermore, the differences in arterial, venous, and lymphatic vessels, as well as innervation are potentially important. In this article, the structure of the human and the mouse pancreas, together with the similarities and differences between them are reviewed in detail in the light of conceivable repercussions for basic research and clinical application.
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Affiliation(s)
- Jurij Dolenšek
- Institute of Physiology; Faculty of Medicine; University of Maribor; Maribor, Slovenia
| | - Marjan Slak Rupnik
- Institute of Physiology; Faculty of Medicine; University of Maribor; Maribor, Slovenia
- Centre for Open Innovations and Research Core@UM; University of Maribor; Maribor, Slovenia
- Institute of Physiology; Center for Physiology and Pharmacology; Medical University of Vienna; Vienna, Austria
| | - Andraž Stožer
- Institute of Physiology; Faculty of Medicine; University of Maribor; Maribor, Slovenia
- Centre for Open Innovations and Research Core@UM; University of Maribor; Maribor, Slovenia
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Abstract
PURPOSE OF REVIEW We highlight some of the major recent advances in characterizing human pancreas development and endocrine cell differentiation. RECENT FINDINGS Extensive research efforts have helped to define crucial events in the mouse pancreas organogenesis. Information gained from these studies was used to develop human embryonic stem cell (hESC) differentiation protocols with the goal of generating functional glucose-responsive, insulin-producing human β-cells. In spite of remarkable progress in hESC differentiation, current protocols based on mouse developmental biology can produce human β-cells only in vivo. New differentiation markers and recently generated reagents may provide an unprecedented opportunity to develop a high-density expression map of human fetal pancreas and pancreatic islets that could serve as a reference point for in vitro hESC differentiation. SUMMARY Integrating an increased knowledge of human pancreas development into hESC differentiation protocols has the potential to greatly advance our ability to generate functional insulin-producing cells for β-cell replacement therapy.
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Affiliation(s)
- Fong Cheng Pan
- Department of Cell and Developmental Biology and Vanderbilt University Program in Developmental Biology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Marcela Brissova
- Division of Diabetes, Endocrinology, and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
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Seeberger KL, Anderson SJ, Ellis CE, Yeung TY, Korbutt GS. Identification and differentiation of PDX1 β-cell progenitors within the human pancreatic epithelium. World J Diabetes 2014; 5:59-68. [PMID: 24567802 PMCID: PMC3932428 DOI: 10.4239/wjd.v5.i1.59] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Revised: 11/27/2013] [Accepted: 12/16/2013] [Indexed: 02/05/2023] Open
Abstract
AIM: To minimize the expansion of pancreatic mesenchymal cells in vitro and confirm that β-cell progenitors reside within the pancreatic epithelium.
METHODS: Due to mesenchymal stem cell (MSC) expansion and overgrowth, progenitor cells within the pancreatic epithelium cannot be characterized in vitro, though β-cell dedifferentiation and expansion of MSC intermediates via epithelial-mesenchymal transition (EMT) may generate β-cell progenitors. Pancreatic epithelial cells from endocrine and non-endocrine tissue were expanded and differentiated in a novel pancreatic epithelial expansion medium supplemented with growth factors known to support epithelial cell growth (dexamethasone, epidermal growth factor, 3,5,3’-triiodo-l-thyronine, bovine brain extract). Cells were also infected with a single and dual lentiviral reporter prior to cell differentiation. Enhanced green fluorescent protein was controlled by the rat Insulin 1 promoter and the monomeric red fluorescent protein was controlled by the mouse PDX1 promoter. In combination with lentiviral tracing, cells expanded and differentiated in the pancreatic medium were characterized by flow cytometry (BD fluorescence activated cell sorting), immunostaining and real-time polymerase chain reaction (PCR) (7900HT Fast Realtime PCR System).
RESULTS: In the presence of 10% serum MSCs rapidly expand in vitro while the epithelial cell population declines. The percentage of vimentin+ cells increased from 22% ± 5.83% to 80.43% ± 3.24% (14 d) and 99.00% ± 0.0% (21 d), and the percentage of epithelial cells decreased from 74.71% ± 8.34% to 26.57% ± 9.75% (14 d) and 4.00% ± 1.53% (21 d), P < 0.01 for all time points. Our novel pancreatic epithelial expansion medium preserved the epithelial cell phenotype and minimized epithelial cell dedifferentiation and EMT. Cells expanded in our epithelial medium contained significantly less mesenchymal cells (vimentin+) compared to controls (44.87% ± 4.93% vs 95.67% ± 1.36%; P < 0.01). During cell differentiation lentiviral reporting demonstrated that, PDX1+ and insulin+ cells were localized within adherent epithelial cell aggregates compared to controls. Compared to starting islets differentiated cells had at least two fold higher gene expression of PDX1, insulin, PAX4 and RFX (P < 0.05).
CONCLUSION: PDX1+ cells were confined to adherent epithelial cell aggregates and not vimentin+ cells (mesenchymal), suggesting that EMT is not a mechanism for generating pancreatic progenitor cells.
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