1
|
Bany Bakar R, Reimann F, Gribble FM. The intestine as an endocrine organ and the role of gut hormones in metabolic regulation. Nat Rev Gastroenterol Hepatol 2023; 20:784-796. [PMID: 37626258 DOI: 10.1038/s41575-023-00830-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 07/25/2023] [Indexed: 08/27/2023]
Abstract
Gut hormones orchestrate pivotal physiological processes in multiple metabolically active tissues, including the pancreas, liver, adipose tissue, gut and central nervous system, making them attractive therapeutic targets in the treatment of obesity and type 2 diabetes mellitus. Most gut hormones are derived from enteroendocrine cells, but bioactive peptides that are derived from other intestinal epithelial cell types have also been implicated in metabolic regulation and can be considered gut hormones. A deeper understanding of the complex inter-organ crosstalk mediated by the intestinal endocrine system is a prerequisite for designing more effective drugs that are based on or target gut hormones and their receptors, and extending their therapeutic potential beyond obesity and diabetes mellitus. In this Review, we present an overview of gut hormones that are involved in the regulation of metabolism and discuss their action in the gastrointestinal system and beyond.
Collapse
Affiliation(s)
- Rula Bany Bakar
- Wellcome Trust-MRC Institute of Metabolic Science Metabolic Research Laboratories, University of Cambridge, Cambridge, UK
| | - Frank Reimann
- Wellcome Trust-MRC Institute of Metabolic Science Metabolic Research Laboratories, University of Cambridge, Cambridge, UK
| | - Fiona M Gribble
- Wellcome Trust-MRC Institute of Metabolic Science Metabolic Research Laboratories, University of Cambridge, Cambridge, UK.
| |
Collapse
|
2
|
Sionov RV, Ahdut-HaCohen R. A Supportive Role of Mesenchymal Stem Cells on Insulin-Producing Langerhans Islets with a Specific Emphasis on The Secretome. Biomedicines 2023; 11:2558. [PMID: 37761001 PMCID: PMC10527322 DOI: 10.3390/biomedicines11092558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 09/06/2023] [Accepted: 09/14/2023] [Indexed: 09/29/2023] Open
Abstract
Type 1 Diabetes (T1D) is a chronic autoimmune disease characterized by a gradual destruction of insulin-producing β-cells in the endocrine pancreas due to innate and specific immune responses, leading to impaired glucose homeostasis. T1D patients usually require regular insulin injections after meals to maintain normal serum glucose levels. In severe cases, pancreas or Langerhans islet transplantation can assist in reaching a sufficient β-mass to normalize glucose homeostasis. The latter procedure is limited because of low donor availability, high islet loss, and immune rejection. There is still a need to develop new technologies to improve islet survival and implantation and to keep the islets functional. Mesenchymal stem cells (MSCs) are multipotent non-hematopoietic progenitor cells with high plasticity that can support human pancreatic islet function both in vitro and in vivo and islet co-transplantation with MSCs is more effective than islet transplantation alone in attenuating diabetes progression. The beneficial effect of MSCs on islet function is due to a combined effect on angiogenesis, suppression of immune responses, and secretion of growth factors essential for islet survival and function. In this review, various aspects of MSCs related to islet function and diabetes are described.
Collapse
Affiliation(s)
- Ronit Vogt Sionov
- The Institute of Biomedical and Oral Research (IBOR), Faculty of Dental Medicine, The Hebrew University of Jerusalem, Jerusalem 9112102, Israel
| | - Ronit Ahdut-HaCohen
- Department of Medical Neurobiology, Institute of Medical Research, Hadassah Medical School, The Hebrew University of Jerusalem, Jerusalem 9112102, Israel;
- Department of Science, The David Yellin Academic College of Education, Jerusalem 9103501, Israel
| |
Collapse
|
3
|
Zang P, Yang C, Lei H, Guo Q, Wang W, Shao J. Ghrelin regulates the proliferation and apoptosis of high glucose-induced islet cells through the PI3K-Akt signaling pathway. Cell Biol Int 2023; 47:768-775. [PMID: 36718083 DOI: 10.1002/cbin.11981] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 12/09/2022] [Accepted: 12/15/2022] [Indexed: 02/01/2023]
Abstract
Ghrelin may have therapeutic value in mitigating insulin resistance and type 2 diabetes, based on which we further explore the action mechanism of ghrelin on islet cells in this research. In the course of experiments, MIN6 cells were induced by glucose and then treated with acylated or unacylated ghrelin. The effects of ghrelin on the viability, proliferation, apoptosis, and insulin release of high glucose-induced islet cells were detected by Cell Counting Kit-8, 5-ethynyl-2'-deoxyuridine, flow cytometry, and enzyme-linked immunosorbent assays, respectively. Meanwhile, cells were treated with LY294002 to explore whether and how the inhibited phosphoinositide 3-kinase-protein kinase B (PI3K-AKT) signaling pathway participated in the internal mechanism of ghrelin-regulating islet cells. Western blotting was performed to quantify the expression levels of Bcl-2, Bax, Cleaved caspase-3, PI3K, and AKT. As a result, ghrelin alleviated high glucose-induced suppression of viability and proliferation and promotion on apoptosis of MIN6 cells. Ghrelin also attenuated the inhibitory effects of high glucose on expression levels of PI3K-Akt signaling axis-related proteins and insulin release in MIN6 cells. Besides, ghrelin weakened the impacts of high glucose on boosting MIN6 cell apoptosis and hindering proliferation through the PI3K-Akt signaling axis. Collectively, ghrelin regulates the proliferation and apoptosis of high glucose-induced islet cells through the PI3K-Akt signaling pathway.
Collapse
Affiliation(s)
- Pu Zang
- Department of Endocrinology, Jinling Hospital, School of Medicine, Nanjing University, Nanjing, China
| | - Cuihua Yang
- Department of Endocrinology, Jinling Hospital, School of Medicine, Nanjing University, Nanjing, China
| | - Haiyan Lei
- Department of Endocrinology, Jinling Hospital, School of Medicine, Nanjing University, Nanjing, China
| | - Qingyu Guo
- Department of Endocrinology, Jinling Hospital, School of Medicine, Nanjing University, Nanjing, China
| | - Wei Wang
- Department of Endocrinology, Jinling Hospital, School of Medicine, Nanjing University, Nanjing, China
| | - Jiaqing Shao
- Department of Endocrinology, Jinling Hospital, School of Medicine, Nanjing University, Nanjing, China
| |
Collapse
|
4
|
Kim HT, Desouza AH, Umhoefer H, Han J, Anzia L, Sacotte SJ, Williams RA, Blumer JT, Bartosiak JT, Fontaine DA, Baan M, Kibbe CR, Davis DB. Cholecystokinin attenuates β-cell apoptosis in both mouse and human islets. Transl Res 2022; 243:1-13. [PMID: 34740874 PMCID: PMC9504967 DOI: 10.1016/j.trsl.2021.10.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 09/23/2021] [Accepted: 10/24/2021] [Indexed: 11/17/2022]
Abstract
Loss of functional pancreatic β-cell mass and increased β-cell apoptosis are fundamental to the pathophysiology of type 1 and type 2 diabetes. Pancreatic islet transplantation has the potential to cure type 1 diabetes but is often ineffective due to the death of the islet graft within the first few years after transplant. Therapeutic strategies to directly target pancreatic β-cell survival are needed to prevent and treat diabetes and to improve islet transplant outcomes. Reducing β-cell apoptosis is also a therapeutic strategy for type 2 diabetes. Cholecystokinin (CCK) is a peptide hormone typically produced in the gut after food intake, with positive effects on obesity and glucose metabolism in mouse models and human subjects. We have previously shown that pancreatic islets also produce CCK. The production of CCK within the islet promotes β-cell survival in rodent models of diabetes and aging. We demonstrate a direct effect of CCK to reduce cytokine-mediated apoptosis in a β-cell line and in isolated mouse islets in a receptor-dependent manner. However, whether CCK can protect human β-cells was previously unknown. Here, we report that CCK can also reduce cytokine-mediated apoptosis in isolated human islets and CCK treatment in vivo decreases β-cell apoptosis in human islets transplanted into the kidney capsule of diabetic NOD/SCID mice. Collectively, these data identify CCK as a novel therapy that can directly promote β-cell survival in human islets and has therapeutic potential to preserve β-cell mass in diabetes and as an adjunct therapy after transplant.
Collapse
Affiliation(s)
- Hung Tae Kim
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Wisconsin-Madison, Madison, Wisconsin
| | - Arnaldo H Desouza
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Wisconsin-Madison, Madison, Wisconsin
| | - Heidi Umhoefer
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Wisconsin-Madison, Madison, Wisconsin
| | - Jeeyoung Han
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Wisconsin-Madison, Madison, Wisconsin
| | - Lucille Anzia
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Wisconsin-Madison, Madison, Wisconsin
| | - Steven J Sacotte
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Wisconsin-Madison, Madison, Wisconsin
| | - Rashaun A Williams
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Wisconsin-Madison, Madison, Wisconsin
| | - Joseph T Blumer
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Wisconsin-Madison, Madison, Wisconsin
| | - Jacob T Bartosiak
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Wisconsin-Madison, Madison, Wisconsin
| | - Danielle A Fontaine
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Wisconsin-Madison, Madison, Wisconsin
| | - Mieke Baan
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Wisconsin-Madison, Madison, Wisconsin
| | - Carly R Kibbe
- Department of Human Biology, University of Wisconsin-Green Bay, Green Bay, Wisconsin.
| | - Dawn Belt Davis
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Wisconsin-Madison, Madison, Wisconsin; William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin.
| |
Collapse
|
5
|
Ko J, Jang S, Kwon W, Kim SY, Jang S, Kim E, Ji YR, Park S, Kim MO, Choi SK, Cho DH, Lee HS, Lim SG, Ryoo ZY. Protective Effect of GIP against Monosodium Glutamate-Induced Ferroptosis in Mouse Hippocampal HT-22 Cells through the MAPK Signaling Pathway. Antioxidants (Basel) 2022; 11:antiox11020189. [PMID: 35204073 PMCID: PMC8868324 DOI: 10.3390/antiox11020189] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 01/10/2022] [Accepted: 01/17/2022] [Indexed: 02/08/2023] Open
Abstract
The effect of glucose-dependent insulinotropic polypeptide (GIP) on cells under oxidative stress induced by glutamate, a neurotransmitter, and the underlying molecular mechanisms were assessed in the present study. We found that in the pre-treatment of HT-22 cells with glutamate in a dose-dependent manner, intracellular ROS were excessively generated, and additional cell damage occurred in the form of lipid peroxidation. The neurotoxicity caused by excessive glutamate was found to be ferroptosis and not apoptosis. Other factors (GPx-4, Nrf2, Nox1 and Hspb1) involved in ferroptosis were also identified. In other words, it was confirmed that GIP increased the activity of sub-signalling molecules in the process of suppressing ferroptosis as an antioxidant and maintained a stable cell cycle even under glutamate-induced neurotoxicity. At the same time, in HT-22 cells exposed to ferroptosis as a result of excessive glutamate accumulation, GIP sustained cell viability by activating the mitogen-activated protein kinase (MAPK) signalling pathway. These results suggest that the overexpression of the GIP gene increases cell viability by regulating mechanisms related to cytotoxicity and reactive oxygen species production in hippocampal neuronal cell lines.
Collapse
Affiliation(s)
- Jiwon Ko
- BK21 FOUR KNU Creative BioResearch Group, School of Life Sciences, Kyungpook National University, Daegu 41566, Korea; (J.K.); (S.J.); (S.-Y.K.); (S.J.); (Y.-R.J.); (D.-H.C.); (H.-S.L.)
| | - Soyoung Jang
- BK21 FOUR KNU Creative BioResearch Group, School of Life Sciences, Kyungpook National University, Daegu 41566, Korea; (J.K.); (S.J.); (S.-Y.K.); (S.J.); (Y.-R.J.); (D.-H.C.); (H.-S.L.)
| | - Wookbong Kwon
- Core Protein Resources Center, DGIST, Daegu 42988, Korea; (W.K.); (S.-K.C.)
- Division of Biotechnology, DGIST, Daegu 42988, Korea
| | - Si-Yong Kim
- BK21 FOUR KNU Creative BioResearch Group, School of Life Sciences, Kyungpook National University, Daegu 41566, Korea; (J.K.); (S.J.); (S.-Y.K.); (S.J.); (Y.-R.J.); (D.-H.C.); (H.-S.L.)
| | - Soyeon Jang
- BK21 FOUR KNU Creative BioResearch Group, School of Life Sciences, Kyungpook National University, Daegu 41566, Korea; (J.K.); (S.J.); (S.-Y.K.); (S.J.); (Y.-R.J.); (D.-H.C.); (H.-S.L.)
| | - Eungyung Kim
- Department of Animal Science and Biotechnology, Kyungpook National University, Sangju-si 37224, Korea; (E.K.); (M.-O.K.)
| | - Young-Rae Ji
- BK21 FOUR KNU Creative BioResearch Group, School of Life Sciences, Kyungpook National University, Daegu 41566, Korea; (J.K.); (S.J.); (S.-Y.K.); (S.J.); (Y.-R.J.); (D.-H.C.); (H.-S.L.)
- Section on Sensory Cell Regeneration and Development, Laboratory of Molecular Biology, National Institutes of Health, Bethesda, MD 20892, USA
| | - Sijun Park
- School of Life Science, Kyungpook National University, Daegu 42988, Korea;
| | - Myoung-Ok Kim
- Department of Animal Science and Biotechnology, Kyungpook National University, Sangju-si 37224, Korea; (E.K.); (M.-O.K.)
| | - Seong-Kyoon Choi
- Core Protein Resources Center, DGIST, Daegu 42988, Korea; (W.K.); (S.-K.C.)
- Division of Biotechnology, DGIST, Daegu 42988, Korea
| | - Dong-Hyung Cho
- BK21 FOUR KNU Creative BioResearch Group, School of Life Sciences, Kyungpook National University, Daegu 41566, Korea; (J.K.); (S.J.); (S.-Y.K.); (S.J.); (Y.-R.J.); (D.-H.C.); (H.-S.L.)
- Brain Science and Engineering Institute, Kyungpook National University, Daegu 42988, Korea
| | - Hyun-Shik Lee
- BK21 FOUR KNU Creative BioResearch Group, School of Life Sciences, Kyungpook National University, Daegu 41566, Korea; (J.K.); (S.J.); (S.-Y.K.); (S.J.); (Y.-R.J.); (D.-H.C.); (H.-S.L.)
| | - Su-Geun Lim
- School of Life Science, Kyungpook National University, Daegu 42988, Korea;
- Correspondence: (S.-G.L.); (Z.-Y.R.)
| | - Zae-Young Ryoo
- BK21 FOUR KNU Creative BioResearch Group, School of Life Sciences, Kyungpook National University, Daegu 41566, Korea; (J.K.); (S.J.); (S.-Y.K.); (S.J.); (Y.-R.J.); (D.-H.C.); (H.-S.L.)
- Correspondence: (S.-G.L.); (Z.-Y.R.)
| |
Collapse
|
6
|
Conlon JM, O'Harte FPM, Flatt PR. Dual-agonist incretin peptides from fish with potential for obesity-related Type 2 diabetes therapy - A review. Peptides 2022; 147:170706. [PMID: 34861327 DOI: 10.1016/j.peptides.2021.170706] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 11/28/2021] [Accepted: 11/29/2021] [Indexed: 12/25/2022]
Abstract
The long-acting glucagon-like peptide-1 receptor (GLP1R) agonist, semaglutide and the unimolecular glucose-dependent insulinotropic polypeptide receptor (GIPR)/GLP1R dual-agonist, tirzepatide have been successfully introduced as therapeutic options for patients with Type-2 diabetes (T2DM) and obesity. Proglucagon-derived peptides from phylogenetically ancient fish act as naturally occurring dual agonists at the GLP1R and the glucagon receptor (GCGR) with lamprey GLP-1 and paddlefish glucagon being the most potent and effective in stimulating insulin release from BRIN-BD11 clonal β-cells. These peptides were also the most effective in lowering blood glucose and elevating plasma insulin concentrations when administered intraperitoneally to overnight-fasted mice together with a glucose load. Zebrafish GIP acts as a dual agonist at the GIPR and GLP1R receptors. Studies with the high fat-fed mouse, an animal model with obesity, impaired glucose-tolerance and insulin-resistance, have shown that twice-daily administration of the long-acting analogs [D-Ala2]palmitoyl-lamprey GLP-1 and [D-Ser2]palmitoyl-paddlefish glucagon over 21 days improves glucose tolerance and insulin sensitivity. This was associated with β-cell proliferation, protection of β-cells against apoptosis, decreased pancreatic glucagon content, improved lipid profile, reduced food intake and selective alteration in the expression of genes involved in β-cell stimulus-secretion coupling. In insulin-deficient GluCreERT2;ROSA26-eYFP transgenic mice, the peptides promoted an increase in β-cell mass with positive effects on transdifferentiation of glucagon-producing to insulin-producing cells. Naturally occurring fish dual agonist peptides, particularly lamprey GLP-1 and paddlefish glucagon, provide templates for development into therapeutic agents for obesity-related T2DM.
Collapse
Affiliation(s)
- J Michael Conlon
- Diabetes Research Group, School of Biomedical Sciences, Ulster University, Cromore Road, Coleraine, BT52 1SA, Northern Ireland, UK.
| | - Finbarr P M O'Harte
- Diabetes Research Group, School of Biomedical Sciences, Ulster University, Cromore Road, Coleraine, BT52 1SA, Northern Ireland, UK
| | - Peter R Flatt
- Diabetes Research Group, School of Biomedical Sciences, Ulster University, Cromore Road, Coleraine, BT52 1SA, Northern Ireland, UK
| |
Collapse
|
7
|
Bosma KJ, Andrei SR, Katz LS, Smith AA, Dunn JC, Ricciardi VF, Ramirez MA, Baumel-Alterzon S, Pace WA, Carroll DT, Overway EM, Wolf EM, Kimple ME, Sheng Q, Scott DK, Breyer RM, Gannon M. Pharmacological blockade of the EP3 prostaglandin E 2 receptor in the setting of type 2 diabetes enhances β-cell proliferation and identity and relieves oxidative damage. Mol Metab 2021; 54:101347. [PMID: 34626853 PMCID: PMC8529552 DOI: 10.1016/j.molmet.2021.101347] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 09/02/2021] [Accepted: 09/23/2021] [Indexed: 12/27/2022] Open
Abstract
OBJECTIVE Type 2 diabetes is characterized by hyperglycemia and inflammation. Prostaglandin E2, which signals through four G protein-coupled receptors (EP1-4), is a mediator of inflammation and is upregulated in diabetes. We have shown previously that EP3 receptor blockade promotes β-cell proliferation and survival in isolated mouse and human islets ex vivo. Here, we analyzed whether systemic EP3 blockade could enhance β-cell mass and identity in the setting of type 2 diabetes using mice with a spontaneous mutation in the leptin receptor (Leprdb). METHODS Four- or six-week-old, db/+, and db/db male mice were treated with an EP3 antagonist daily for two weeks. Pancreata were analyzed for α-cell and β-cell proliferation and β-cell mass. Islets were isolated for transcriptomic analysis. Selected gene expression changes were validated by immunolabeling of the pancreatic tissue sections. RESULTS EP3 blockade increased β-cell mass in db/db mice through enhanced β-cell proliferation. Importantly, there were no effects on α-cell proliferation. EP3 blockade reversed the changes in islet gene expression associated with the db/db phenotype and restored the islet architecture. Expression of the GLP-1 receptor was slightly increased by EP3 antagonist treatment in db/db mice. In addition, the transcription factor nuclear factor E2-related factor 2 (Nrf2) and downstream targets were increased in islets from db/db mice in response to treatment with an EP3 antagonist. The markers of oxidative stress were decreased. CONCLUSIONS The current study suggests that EP3 blockade promotes β-cell mass expansion in db/db mice. The beneficial effects of EP3 blockade may be mediated through Nrf2, which has recently emerged as a key mediator in the protection against cellular oxidative damage.
Collapse
Affiliation(s)
- Karin J Bosma
- Dept. of Veterans Affairs Tennessee Valley Authority, Nashville, TN, USA; Dept. of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Spencer R Andrei
- Dept. of Veterans Affairs Tennessee Valley Authority, Nashville, TN, USA; Dept. of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Liora S Katz
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Ashley A Smith
- Dept. of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA
| | - Jennifer C Dunn
- Dept. of Veterans Affairs Tennessee Valley Authority, Nashville, TN, USA; Dept. of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | | | - Marisol A Ramirez
- Center for Quantitative Sciences, Vanderbilt University Medical Center, Nashville, TN, USA; Dept. of Biostatistics, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Sharon Baumel-Alterzon
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - William A Pace
- Dept. of Biomedical Engineering, Vanderbilt University, Nashville, TN, USA
| | - Darian T Carroll
- Dept. of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA
| | - Emily M Overway
- Dept. of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA
| | - Elysa M Wolf
- Program in Cancer Biology, Vanderbilt University, Nashville, TN, USA
| | - Michelle E Kimple
- Dept. of Medicine, University of Wisconsin, Madison, WI, USA; William S. Middleton Memorial Veterans Hospital, Madison, WI, USA
| | - Quanhu Sheng
- Center for Quantitative Sciences, Vanderbilt University Medical Center, Nashville, TN, USA; Dept. of Biostatistics, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Donald K Scott
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Richard M Breyer
- Dept. of Veterans Affairs Tennessee Valley Authority, Nashville, TN, USA; Dept. of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Maureen Gannon
- Dept. of Veterans Affairs Tennessee Valley Authority, Nashville, TN, USA; Dept. of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA; Dept. of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA.
| |
Collapse
|
8
|
Karras SN, Koufakis T, Mustafa OG, Kotsa K. Anti-incretin effect: The other face of Janus in human glucose homeostasis. Obes Rev 2019; 20:1597-1607. [PMID: 31347774 DOI: 10.1111/obr.12917] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 06/26/2019] [Accepted: 07/02/2019] [Indexed: 02/06/2023]
Abstract
The provocative idea that type 2 diabetes (T2D) may be a surgically treated disorder is based on accumulating evidence suggesting impressive remission rates of obesity and diabetes following bariatric surgery interventions. According to the "anti-incretin" theory, ingestion of food in the gastrointestinal (GI) tract, apart from activating the well-described incretin effect, also results in the parallel stimulation of a series of negative feedback mechanisms (anti-incretin effect). The primary goal of these regulations is to counteract the effects of incretins and other postprandial glucose-lowering adaptive mechanisms. Disruption of the equilibrium between incretins and anti-incretins could be an additional pathway leading to the development of insulin resistance and hyperglycemia. This theory provides an alternative theoretical framework to explain the mechanisms behind the optimal effects of metabolic surgery on T2D and underlines the importance of the GI tract in the homeostatic regulation of energy balance in humans. The anti-incretin concept is currently based on a limited amount of evidence and certainly requires further validation by additional studies. The aim of the present review is to discuss and critically evaluate recent evidence on the anti-incretin theory, providing an insight into current state and future perspectives.
Collapse
Affiliation(s)
- Spyridon N Karras
- Division of Endocrinology and Metabolism and Diabetes Center, First Department of Internal Medicine, Medical School, Aristotle University of Thessaloniki, AHEPA University Hospital, Thessaloniki, Greece
| | - Theocharis Koufakis
- Division of Endocrinology and Metabolism and Diabetes Center, First Department of Internal Medicine, Medical School, Aristotle University of Thessaloniki, AHEPA University Hospital, Thessaloniki, Greece
| | - Omar G Mustafa
- Department of Diabetes, King's College Hospital, London, UK
| | - Kalliopi Kotsa
- Division of Endocrinology and Metabolism and Diabetes Center, First Department of Internal Medicine, Medical School, Aristotle University of Thessaloniki, AHEPA University Hospital, Thessaloniki, Greece
| |
Collapse
|
9
|
Koltes JE, Arora I, Gupta R, Nguyen DC, Schaid M, Kim JA, Kimple ME, Bhatnagar S. A gene expression network analysis of the pancreatic islets from lean and obese mice identifies complement 1q like-3 secreted protein as a regulator of β-cell function. Sci Rep 2019; 9:10119. [PMID: 31300714 PMCID: PMC6626003 DOI: 10.1038/s41598-019-46219-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Accepted: 06/24/2019] [Indexed: 12/29/2022] Open
Abstract
Secreted proteins are important metabolic regulators. Identifying and characterizing the role of secreted proteins from small tissue depots such as islets of Langerhans, which are required for the proper control of whole-body energy metabolism, remains challenging. Our objective was to identify islet-derived secreted proteins that affect islet function in obesity. Lean and obese mouse islet expression data were analyzed by weighted gene co-expression network analysis (WGCNA) to identify trait-associated modules. Subsequently, genes within these modules were filtered for transcripts that encode for secreted proteins based on intramodular connectivity, module membership, and differential expression. Complement 1q like-3 (C1ql3) secreted protein was identified as a hub gene affecting islet function in obesity. Co-expression network, hierarchal clustering, and gene-ontology based approaches identified a putative role for C1ql3 in regulating β-cell insulin secretion. Biological validation shows that C1ql3 is expressed in β-cells, it inhibits insulin secretion and key genes that are involved in β-cell function. Moreover, the increased expression of C1ql3 is correlated with the reduced insulin secretion in islets of obese mice. Herein, we demonstrate a streamlined approach to effectively screen and determine the function of secreted proteins in islets, and identified C1ql3 as a putative contributor to reduced insulin secretion in obesity, linking C1ql3 to an increased susceptibility to type 2 diabetes.
Collapse
Affiliation(s)
- James E Koltes
- Department of Animal Science, Iowa State University, Ames, IA, 50011, USA
| | - Itika Arora
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine and Comprehensive Diabetes Center, University of Alabama, Birmingham, AL, 35294, USA
| | - Rajesh Gupta
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine and Comprehensive Diabetes Center, University of Alabama, Birmingham, AL, 35294, USA
| | - Dan C Nguyen
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine and Comprehensive Diabetes Center, University of Alabama, Birmingham, AL, 35294, USA
| | - Michael Schaid
- Interdisciplinary Graduate Program in Nutritional Sciences, University of Wisconsin-Madison College of Agriculture and Life Sciences, Madison, WI, 53706, USA.,Research Service, William S Middleton Memorial VA Hospital, Madison, WI, 53705, USA
| | - Jeong-A Kim
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine and Comprehensive Diabetes Center, University of Alabama, Birmingham, AL, 35294, USA
| | - Michelle E Kimple
- Interdisciplinary Graduate Program in Nutritional Sciences, University of Wisconsin-Madison College of Agriculture and Life Sciences, Madison, WI, 53706, USA.,Divison of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, 53705, USA.,Department of Cell and Regenerative Biology, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, 53705, USA.,Department of Academic Affairs, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, 53705, USA.,Research Service, William S Middleton Memorial VA Hospital, Madison, WI, 53705, USA
| | - Sushant Bhatnagar
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine and Comprehensive Diabetes Center, University of Alabama, Birmingham, AL, 35294, USA.
| |
Collapse
|
10
|
Abstract
PURPOSE OF REVIEW Pancreatic β-cells play a critical role in whole-body glucose homeostasis by regulating the release of insulin in response to minute by minute alterations in metabolic demand. As such, β-cells are staunchly resilient but there are circumstances where they can become functionally compromised or physically lost due to pathophysiological changes which culminate in overt hyperglycemia and diabetes. RECENT FINDINGS In humans, β-cell mass appears to be largely defined in the postnatal period and this early replicative and generative phase is followed by a refractory state which persists throughout life. Despite this, efforts to identify physiological and pharmacological factors which might re-initiate β-cell replication (or cause the replenishment of β-cells by neogenesis or transdifferentiation) are beginning to bear fruit. Controlled manipulation of β-cell mass in humans still represents a holy grail for therapeutic intervention in diabetes, but progress is being made which may lead to ultimate success.
Collapse
Affiliation(s)
- Giorgio Basile
- Islet Cell and Regenerative Biology, Joslin Diabetes Center, Department of Medicine, Harvard Medical School, Harvard Stem Cell Institute, Boston, MA 02215, USA
| | - Rohit N. Kulkarni
- Islet Cell and Regenerative Biology, Joslin Diabetes Center, Department of Medicine, Harvard Medical School, Harvard Stem Cell Institute, Boston, MA 02215, USA
| | - Noel G. Morgan
- Institute of Biomedical & Clinical Science, University of Exeter Medical School, Exeter EX2 5DW, UK
| |
Collapse
|
11
|
Chen X, Huang T, Shi Y, Wang L, Li W, Shen F, Gu X. A GLP‑1 receptor agonist attenuates human islet amyloid polypeptide‑induced autophagy and apoptosis in MIN6 cells. Mol Med Rep 2018; 19:1365-1371. [PMID: 30569165 DOI: 10.3892/mmr.2018.9741] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Accepted: 09/21/2018] [Indexed: 11/06/2022] Open
Abstract
Type 2 diabetes mellitus (T2DM) is characterized by the dysfunction and loss of pancreatic islet β‑cells, in part due to islet amyloid deposits derived from islet amyloid polypeptide (IAPP). The glucagon‑like peptide‑1 (GLP‑1) receptor agonist exendin‑4 enhances the insulin secretory response by increasing β‑cell mass in T2DM. However, it is unknown whether exendin‑4 protects β‑cells from IAPP‑mediated autophagy and apoptosis. In the present study, reverse transcription‑quantitative polymerase chain reaction, ELISA and western blotting were used to detected the mRNA and protein expression of insulin/hIAPP and other signaling molecules, while the mechanisms underlying these effects were also determined. Exendin‑4 increased the level of insulin secretion, which was greater than that of IAPP, leading to a beneficial IAPP/insulin secretion pattern. In MIN6 cells incubated with 25 mM glucose, exendin‑4 decreased the ratio of light chain 3 (LC3)‑II/I, which was accompanied by an increase in p62 protein. In a hIAPP‑overexpressing MIN6 cell model, exendin‑4 prevented the hIAPP‑induced increase in the LC3II/I ratio and decrease in p62 expression. In addition, exendin‑4 pretreatment reduced hIAPP‑induced activation of cleaved caspase‑3, suggesting that exendin‑4 may protect MIN6 cells against apoptosis. Taken together, the results highlight hIAPP as a critical mediator of β‑cell loss and suggest that the GLP‑1 receptor agonist exendin‑4 may be a potential therapeutic agent for hIAPP‑induced β‑cell damage.
Collapse
Affiliation(s)
- Xiong Chen
- Department of Endocrinology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325000, P.R. China
| | - Tingting Huang
- Department of Endocrinology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325000, P.R. China
| | - Yujuan Shi
- Department of Endocrinology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325000, P.R. China
| | - Luyin Wang
- Department of Endocrinology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325000, P.R. China
| | - Wei Li
- Department of Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang 325000, P.R. China
| | - Feixia Shen
- Department of Endocrinology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325000, P.R. China
| | - Xuemei Gu
- Department of Endocrinology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325000, P.R. China
| |
Collapse
|
12
|
Lautenbach A, Wernecke M, Riedel N, Veigel J, Yamamura J, Keller S, Jung R, Busch P, Mann O, Knop FK, Holst JJ, Meier JJ, Aberle J. Adaptive changes in pancreas post Roux-en-Y gastric bypass induced weight loss. Diabetes Metab Res Rev 2018; 34:e3025. [PMID: 29768729 DOI: 10.1002/dmrr.3025] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Revised: 03/03/2018] [Accepted: 05/07/2018] [Indexed: 12/12/2022]
Abstract
BACKGROUND Obesity has been shown to trigger adaptive increases in pancreas parenchymal and fat volume. Consecutively, pancreatic steatosis may lead to beta-cell dysfunction. However, it is not known whether the pancreatic tissue components decrease with weight loss and pancreatic steatosis is reversible following Roux-en-Y gastric bypass (RYGB). Therefore, the objective of the study was to investigate the effects of RYGB-induced weight loss on pancreatic volume and glucose homeostasis. METHODS Eleven patients were recruited in the Obesity Centre of the University Medical Centre Hamburg-Eppendorf. Before and 6 months after RYGB, total GLP-1 levels were measured during oral glucose tolerance test. To assess changes in visceral adipose tissue and pancreatic volume, MRI was performed. Measures of glucose homeostasis and insulin indices were assessed. Fractional beta-cell area was estimated by correlation with the C-peptide-to-glucose ratio; beta-cell mass was calculated by the product of beta-cell area and pancreas parenchymal weight. RESULTS Pancreas volume decreased from 83.8 (75.7-92.0) to 70.5 (58.8-82.3) cm3 (mean [95% CI], P = .001). The decrease in total volume was associated with a significant decrease in fat volume. Fasting insulin and C-peptide were lower post RYGB. HOMA-IR levels decreased, whereas insulin sensitivity increased (P = .03). This was consistent with a reduction in the estimated beta-cell area and mass. CONCLUSIONS Following RYGB, pancreatic volume and steatosis adaptively decreased to "normal" levels with accompanying improvement in glucose homeostasis. Moreover, obesity-driven beta-cell expansion seems to be reversible; however, future studies must define a method to more accurately estimate functional beta-cell mass to increase our understanding of glucose homeostasis after RYGB.
Collapse
Affiliation(s)
- A Lautenbach
- Department for Endocrinology and Diabetology, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany
| | - M Wernecke
- Department for Endocrinology and Diabetology, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany
| | - N Riedel
- Department for Endocrinology and Diabetology, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany
| | - J Veigel
- Department for Endocrinology and Diabetology, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany
| | - J Yamamura
- Department for Diagnostic and Interventional Radiology, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany
| | - S Keller
- Department for Diagnostic and Interventional Radiology, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany
| | - R Jung
- Institute for Clinical Chemistry and Laboratory Medicine, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany
| | - P Busch
- General, Visceral and Thoracic Surgery Department, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany
| | - O Mann
- General, Visceral and Thoracic Surgery Department, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany
| | - F K Knop
- Centre for Diabetes Research, Gentofte Hospital, University of Copenhagen, Hellerup, Denmark
| | - J J Holst
- NNF Centre for Basic Metabolic Research and Department of Biomedical Sciences, The Panum Institute, University of Copenhagen, Copenhagen, Denmark
| | - J J Meier
- Diabetes Division, Department of Medicine I, St Josef Hospital, Ruhr University Bochum, Bochum, Germany
| | - J Aberle
- Department for Endocrinology and Diabetology, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany
| |
Collapse
|
13
|
Jiang WJ, Peng YC, Yang KM. Cellular signaling pathways regulating β-cell proliferation as a promising therapeutic target in the treatment of diabetes. Exp Ther Med 2018; 16:3275-3285. [PMID: 30233674 PMCID: PMC6143874 DOI: 10.3892/etm.2018.6603] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Accepted: 07/27/2018] [Indexed: 12/30/2022] Open
Abstract
It is established that a decrease in β-cell number and deficiency in the function of existing β-cells contribute to type 1 and type 2 diabetes mellitus. Therefore, a major focus of current research is to identify novel methods of improving the number and function of β-cells, so as to prevent and/or postpone the development of diabetes mellitus and potentially reverse diabetes mellitus. Based on prior knowledge of the above-mentioned causes, promising therapeutic approaches may include direct transplantation of islets, implantation and subsequent induced differentiation of progenitors/stem cells to β-cells, replication of pre-existing β-cells, or activation of endogenous β-cell progenitors. More recently, with regards to cell replacement and regenerative treatment for diabetes patients, the identification of cellular signaling pathways with related genes or corresponding proteins involved in diabetes has become a topic of interest. However, the majority of pathways and molecules associated with β-cells remain unresolved, and the specialized functions of known pathways remain unclear, particularly in humans. The current article has evaluated the progress of research on pivotal cellular signaling pathways involved with β-cell proliferation and survival, and their validity for therapeutic adult β-cell regeneration in diabetes. More efforts are required to elucidate the cellular events involved in human β-cell proliferation in terms of the underlying mechanisms and functions.
Collapse
Affiliation(s)
- Wen-Juan Jiang
- Institute of Anatomy, Basic Medical College of Dali University, Dali, Yunnan 671000, P.R. China
| | - Yun-Chuan Peng
- Institute of Anatomy, Basic Medical College of Dali University, Dali, Yunnan 671000, P.R. China
| | - Kai-Ming Yang
- Institute of Anatomy, Basic Medical College of Dali University, Dali, Yunnan 671000, P.R. China
| |
Collapse
|
14
|
Yang X, Yue R, Zhang J, Zhang X, Liu Y, Chen C, Wang X, Luo H, Wang WE, Chen X, Wang HJ, Jose PA, Wang H, Zeng C. Gastrin Protects Against Myocardial Ischemia/Reperfusion Injury via Activation of RISK (Reperfusion Injury Salvage Kinase) and SAFE (Survivor Activating Factor Enhancement) Pathways. J Am Heart Assoc 2018; 7:e005171. [PMID: 30005556 PMCID: PMC6064830 DOI: 10.1161/jaha.116.005171] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Accepted: 05/16/2018] [Indexed: 12/27/2022]
Abstract
BACKGROUND Ischemia/reperfusion injury (IRI) is one of the most predominant complications of ischemic heart disease. Gastrin has emerged as a regulator of cardiovascular function, playing a key protective role in hypoxia. Serum gastrin levels are increased in patients with myocardial infarction, but the pathophysiogical significance of this finding is unknown. The purpose of this study was to determine whether and how gastrin protects cardiac myocytes from IRI. METHODS AND RESULTS Adult male Sprague-Dawley rats were used in the experiments. The hearts in living rats or isolated Langendorff-perfused rat hearts were subjected to ischemia followed by reperfusion to induce myocardial IRI. Gastrin, alone or with an antagonist, was administered before the induction of myocardial IRI. We found that gastrin improved myocardial function and reduced the expression of myocardial injury markers, infarct size, and cardiomyocyte apoptosis induced by IRI. Gastrin increased the phosphorylation levels of ERK1/2 (extracellular signal-regulated kinase 1/2), AKT (protein kinase B), and STAT3 (signal transducer and activator of transcription 3), indicating its ability to activate the RISK (reperfusion injury salvage kinase) and SAFE (survivor activating factor enhancement) pathways. The presence of inhibitors of ERK1/2, AKT, or STAT3 abrogated the gastrin-mediated protection. The protective effect of gastrin was via CCK2R (cholecystokinin 2 receptor) because the CCK2R blocker CI988 prevented the gastrin-mediated protection of the heart with IRI. Moreover, we found a negative correlation between serum levels of cardiac troponin I and gastrin in patients with unstable angina pectoris undergoing percutaneous coronary intervention, suggesting a protective effect of gastrin in human cardiomyocytes. CONCLUSIONS These results indicate that gastrin can reduce myocardial IRI by activation of the RISK and SAFE pathways.
Collapse
Affiliation(s)
- Xiaoli Yang
- Department of Cardiology, Chongqing Institute of Cardiology, Daping Hospital, Third Military Medical University, Chongqing, China
| | - Rongchuan Yue
- Department of Cardiology, North Sichuan Medical College First Affiliated Hospital, Nanchong, Sichuan, China
| | - Jun Zhang
- Department of Cardiology, Chongqing Institute of Cardiology, Daping Hospital, Third Military Medical University, Chongqing, China
| | - Xiaoqun Zhang
- Department of Cardiology, Chongqing Institute of Cardiology, Daping Hospital, Third Military Medical University, Chongqing, China
| | - Yukai Liu
- Department of Cardiology, Chongqing Institute of Cardiology, Daping Hospital, Third Military Medical University, Chongqing, China
| | - Caiyu Chen
- Department of Cardiology, Chongqing Institute of Cardiology, Daping Hospital, Third Military Medical University, Chongqing, China
| | - Xinquan Wang
- Department of Cardiology, Chongqing Institute of Cardiology, Daping Hospital, Third Military Medical University, Chongqing, China
| | - Hao Luo
- Department of Cardiology, Chongqing Institute of Cardiology, Daping Hospital, Third Military Medical University, Chongqing, China
| | - Wei Eric Wang
- Department of Cardiology, Chongqing Institute of Cardiology, Daping Hospital, Third Military Medical University, Chongqing, China
| | - Xiongwen Chen
- Department of Cardiology, Chongqing Institute of Cardiology, Daping Hospital, Third Military Medical University, Chongqing, China
- Cardiovascular Research Center & Department of Physiology, Temple University School of Medicine, Philadelphia, PA
| | - Huixia Judy Wang
- Department of Statistics, The George Washington University, Washington, DC
| | - Pedro A Jose
- Division of Renal Disease & Hypertension, The George Washington University School of Medicine & Health Sciences, Washington, DC
| | - Hongyong Wang
- Department of Cardiology, Chongqing Institute of Cardiology, Daping Hospital, Third Military Medical University, Chongqing, China
| | - Chunyu Zeng
- Department of Cardiology, Chongqing Institute of Cardiology, Daping Hospital, Third Military Medical University, Chongqing, China
| |
Collapse
|
15
|
Arden C. A role for Glucagon-Like Peptide-1 in the regulation of β-cell autophagy. Peptides 2018; 100:85-93. [PMID: 29412836 DOI: 10.1016/j.peptides.2017.12.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 12/04/2017] [Accepted: 12/04/2017] [Indexed: 12/11/2022]
Abstract
Autophagy is a highly conserved intracellular recycling pathway that serves to recycle damaged organelles/proteins or superfluous nutrients during times of nutritional stress to provide energy to maintain intracellular homeostasis and sustain core metabolic functions. Under these conditions, autophagy functions as a cell survival mechanism but impairment of this pathway can lead to pro-death stimuli. Due to their role in synthesising and secreting insulin, pancreatic β-cells have a high requirement for robust degradation pathways. Recent research suggests that functional autophagy is required to maintain β-cell survival and function in response to high fat diet suggesting a pro-survival role. However, a role for autophagy has also been implicated in the pathogenesis of type 2 diabetes. Thus, the pro-survival vs pro-death role of autophagy in regulating β-cell mass requires discussion. Emerging evidence suggests that Glucagon-Like Peptide-1 (GLP-1) may exert beneficial effects on glucose homeostasis via autophagy-dependent pathways both in pancreatic β-cells and in other cell types. The aim of the current review is to: i) summarise the literature surrounding β-cell autophagy and its pro-death vs pro-survival role in regulating β-cell mass; ii) review the literature describing the impact of GLP-1 on β-cell autophagy and in other cell types; iii) discuss the potential underlying mechanisms.
Collapse
Affiliation(s)
- Catherine Arden
- Institute of Cellular Medicine, The Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, UK.
| |
Collapse
|
16
|
Khan D, Moffet CR, Flatt PR, Kelly C. Role of islet peptides in beta cell regulation and type 2 diabetes therapy. Peptides 2018; 100:212-218. [PMID: 29412821 DOI: 10.1016/j.peptides.2017.11.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Revised: 11/22/2017] [Accepted: 11/22/2017] [Indexed: 12/25/2022]
Abstract
The endocrine pancreas is composed of islets of Langerhans, which secrete a variety of peptide hormones critical for the maintenance of glucose homeostasis. Insulin is the primary regulator of glucose and its secretion from beta-cells is tightly regulated in response to physiological demands. Direct cell-cell communication within islets is essential for glucose-induced insulin secretion. Emerging data suggest that islet connectivity is also important in the regulating the release of other islet hormones including glucagon and somatostatin. Autocrine and paracrine signals exerted by secreted peptides within the islet also play a key role. A great deal of attention has focused on classical islet peptides, namely insulin, glucagon and somatostatin. Recently, it has become clear that islets also synthesise and secrete a range of non-classical peptides, which regulate beta-cell function and insulin release. The current review summarises the roles of islet cell connectivity and islet peptide-driven autocrine and paracrine signalling in beta-cell function and survival. The potential to harness the paracrine effects of non-classical islet peptides for the treatment of type 2 diabetes is also briefly discussed.
Collapse
Affiliation(s)
- Dawood Khan
- Northern Ireland Centre for Stratified Medicine, Biomedical Sciences Research Institute, University of Ulster, C-TRIC Building, Altnagelvin Area Hospital, Glenshane Road, L/Derry, BT47 6SB, Northern Ireland, UK
| | - Charlotte R Moffet
- SAAD Centre for Pharmacy and Diabetes, School of Biomedical Sciences, University of Ulster, Coleraine, Northern Ireland, UK
| | - Peter R Flatt
- SAAD Centre for Pharmacy and Diabetes, School of Biomedical Sciences, University of Ulster, Coleraine, Northern Ireland, UK
| | - Catriona Kelly
- Northern Ireland Centre for Stratified Medicine, Biomedical Sciences Research Institute, University of Ulster, C-TRIC Building, Altnagelvin Area Hospital, Glenshane Road, L/Derry, BT47 6SB, Northern Ireland, UK.
| |
Collapse
|
17
|
Aamodt KI, Powers AC. Signals in the pancreatic islet microenvironment influence β-cell proliferation. Diabetes Obes Metab 2017; 19 Suppl 1:124-136. [PMID: 28880471 PMCID: PMC5679109 DOI: 10.1111/dom.13031] [Citation(s) in RCA: 98] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Revised: 05/22/2017] [Accepted: 06/01/2017] [Indexed: 12/31/2022]
Abstract
The progressive loss of pancreatic β-cell mass that occurs in both type 1 and type 2 diabetes is a primary factor driving efforts to identify strategies for effectively increasing, enhancing or restoring β-cell mass. While factors that seem to influence β-cell proliferation in specific contexts have been described, reliable stimulation of human β-cell proliferation has remained a challenge. Importantly, β-cells exist in the context of a complex, integrated pancreatic islet microenvironment where they interact with other endocrine cells, vascular endothelial cells, extracellular matrix, neuronal projections and islet macrophages. This review highlights different components of the pancreatic microenvironment, and reviews what is known about how signaling that occurs between β-cells and these other components influences β-cell proliferation. Future efforts to further define the role of the pancreatic islet microenvironment on β-cell proliferation may lead to the development of successful approaches to increase or restore β-cell mass in diabetes.
Collapse
Affiliation(s)
- Kristie I. Aamodt
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Alvin C. Powers
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN, USA
- Division of Diabetes, Endocrinology, and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
- VA Tennessee Valley Healthcare System, Nashville, TN, USA
| |
Collapse
|
18
|
Guida C, Stephen S, Guitton R, Ramracheya RD. The Role of PYY in Pancreatic Islet Physiology and Surgical Control of Diabetes. Trends Endocrinol Metab 2017; 28:626-636. [PMID: 28533020 DOI: 10.1016/j.tem.2017.04.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Accepted: 04/27/2017] [Indexed: 12/30/2022]
Abstract
Bariatric surgery in obese individuals leads to rapid and lasting remission of type 2 diabetes (T2D). This phenomenon occurs independently of weight loss possibly via a combination of factors. The incretin hormone GLP-1 has so far been recognised as a critical factor. However, recent data have indicated that elevation in another gut hormone, peptide tyrosine tyrosine (PYY), may drive the beneficial effects of surgery. Here we discuss recent findings on PYY-mediated control of glucose homeostasis and its role in diabetes, in the context of what is known for GLP-1. Identification of factors that increase the expression of PYY following bariatric surgery and elucidation of its role in diabetes reversal may have clinical relevance as a nonsurgical therapy for T2D.
Collapse
Affiliation(s)
- Claudia Guida
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, OX37LJ Oxford, UK
| | - Sam Stephen
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, OX37LJ Oxford, UK
| | - Romain Guitton
- Angers University Hospital, 18 Avenue du Général Patton, 49000 Angers, France
| | - Reshma D Ramracheya
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, OX37LJ Oxford, UK.
| |
Collapse
|
19
|
Zummo FP, Cullen KS, Honkanen-Scott M, Shaw JAM, Lovat PE, Arden C. Glucagon-Like Peptide 1 Protects Pancreatic β-Cells From Death by Increasing Autophagic Flux and Restoring Lysosomal Function. Diabetes 2017; 66:1272-1285. [PMID: 28232493 DOI: 10.2337/db16-1009] [Citation(s) in RCA: 88] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Accepted: 02/15/2017] [Indexed: 11/13/2022]
Abstract
Studies in animal models of type 2 diabetes have shown that glucagon-like peptide 1 (GLP-1) receptor agonists prevent β-cell loss. Whether GLP-1 mediates β-cell survival via the key lysosomal-mediated process of autophagy is unknown. In this study, we report that treatment of INS-1E β-cells and primary islets with glucolipotoxicity (0.5 mmol/L palmitate and 25 mmol/L glucose) increases LC3 II, a marker of autophagy. Further analysis indicates a blockage in autophagic flux associated with lysosomal dysfunction. Accumulation of defective lysosomes leads to lysosomal membrane permeabilization and release of cathepsin D, which contributes to cell death. Our data further demonstrated defects in autophagic flux and lysosomal staining in human samples of type 2 diabetes. Cotreatment with the GLP-1 receptor agonist exendin-4 reversed the lysosomal dysfunction, relieving the impairment in autophagic flux and further stimulated autophagy. Small interfering RNA knockdown showed the restoration of autophagic flux is also essential for the protective effects of exendin-4. Collectively, our data highlight lysosomal dysfunction as a critical mediator of β-cell loss and shows that exendin-4 improves cell survival via restoration of lysosomal function and autophagic flux. Modulation of autophagy/lysosomal homeostasis may thus define a novel therapeutic strategy for type 2 diabetes, with the GLP-1 signaling pathway as a potential focus.
Collapse
Affiliation(s)
- Francesco P Zummo
- Institute of Cellular Medicine, Newcastle University, Newcastle-upon-Tyne, U.K
| | - Kirsty S Cullen
- Institute of Cellular Medicine, Newcastle University, Newcastle-upon-Tyne, U.K
| | | | - James A M Shaw
- Institute of Cellular Medicine, Newcastle University, Newcastle-upon-Tyne, U.K
| | - Penny E Lovat
- Institute of Cellular Medicine, Newcastle University, Newcastle-upon-Tyne, U.K
| | - Catherine Arden
- Institute of Cellular Medicine, Newcastle University, Newcastle-upon-Tyne, U.K.
| |
Collapse
|
20
|
Carboneau BA, Allan JA, Townsend SE, Kimple ME, Breyer RM, Gannon M. Opposing effects of prostaglandin E 2 receptors EP3 and EP4 on mouse and human β-cell survival and proliferation. Mol Metab 2017; 6:548-559. [PMID: 28580285 PMCID: PMC5444094 DOI: 10.1016/j.molmet.2017.04.002] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Revised: 03/30/2017] [Accepted: 04/03/2017] [Indexed: 01/02/2023] Open
Abstract
OBJECTIVE Hyperglycemia and systemic inflammation, hallmarks of Type 2 Diabetes (T2D), can induce the production of the inflammatory signaling molecule Prostaglandin E2 (PGE2) in islets. The effects of PGE2 are mediated by its four receptors, E-Prostanoid Receptors 1-4 (EP1-4). EP3 and EP4 play opposing roles in many cell types due to signaling through different G proteins, Gi and GS, respectively. We previously found that EP3 and EP4 expression are reciprocally regulated by activation of the FoxM1 transcription factor, which promotes β-cell proliferation and survival. Our goal was to determine if EP3 and EP4 regulate β-cell proliferation and survival and, if so, to elucidate the downstream signaling mechanisms. METHODS β-cell proliferation was assessed in mouse and human islets ex vivo treated with selective agonists and antagonists for EP3 (sulprostone and DG-041, respectively) and EP4 (CAY10598 and L-161,982, respectively). β-cell survival was measured in mouse and human islets treated with the EP3- and EP4-selective ligands in conjunction with a cytokine cocktail to induce cell death. Changes in gene expression and protein phosphorylation were analyzed in response to modulation of EP3 and EP4 activity in mouse islets. RESULTS Blockade of EP3 enhanced β-cell proliferation in young, but not old, mouse islets in part through phospholipase C (PLC)-γ1 activity. Blocking EP3 also increased human β-cell proliferation. EP4 modulation had no effect on ex vivo proliferation alone. However, blockade of EP3 in combination with activation of EP4 enhanced human, but not mouse, β-cell proliferation. In both mouse and human islets, EP3 blockade or EP4 activation enhanced β-cell survival in the presence of cytokines. EP4 acts in a protein kinase A (PKA)-dependent manner to increase mouse β-cell survival. In addition, the positive effects of FoxM1 activation on β-cell survival are inhibited by EP3 and dependent on EP4 signaling. CONCLUSIONS Our results identify EP3 and EP4 as novel regulators of β-cell proliferation and survival in mouse and human islets ex vivo.
Collapse
Key Words
- COX-2, cyclooxygenase-2
- Cell death
- DAG, diacylglycerol
- EP1-4, E-Prostanoid Receptors 1-4
- GPCR, G protein-coupled receptor
- IP3, inositol 1,4,5-trisphosphate
- PGE2, prostaglandin E2
- PKA, protein kinase A
- PL, placental lactogen
- PLC, phospholipase C
- PT, pertussis toxin
- Pancreatic β-cell
- Proliferation
- Prostaglandin E2
Collapse
Affiliation(s)
- Bethany A Carboneau
- Department of Veterans Affairs, Tennessee Valley Health Authority, Nashville, TN, USA.,Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA.,Program in Developmental Biology, Vanderbilt University, Nashville, TN, USA
| | - Jack A Allan
- School of Medicine, Virginia Commonwealth University, Richmond, VA, USA
| | - Shannon E Townsend
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA
| | - Michelle E Kimple
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin-Madison, Madison, WI, USA.,William S. Middleton Memorial Veterans Hospital, Madison, WI, USA
| | - Richard M Breyer
- Department of Veterans Affairs, Tennessee Valley Health Authority, Nashville, TN, USA.,Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Maureen Gannon
- Department of Veterans Affairs, Tennessee Valley Health Authority, Nashville, TN, USA.,Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA.,Program in Developmental Biology, Vanderbilt University, Nashville, TN, USA.,Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA.,Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN, USA
| |
Collapse
|
21
|
Linnemann AK, Davis DB. Glucagon-like peptide-1 and cholecystokinin production and signaling in the pancreatic islet as an adaptive response to obesity. J Diabetes Investig 2016; 7 Suppl 1:44-9. [PMID: 27186355 PMCID: PMC4854504 DOI: 10.1111/jdi.12465] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Accepted: 12/21/2015] [Indexed: 12/22/2022] Open
Abstract
Precise control of blood glucose is dependent on adequate β‐cell mass and function. Thus, reductions in β‐cell mass and function lead to insufficient insulin production to meet demand, and result in diabetes. Recent evidence suggests that paracrine signaling in the islet might be important in obesity, and disruption of this signaling could play a role in the pathogenesis of diabetes. For example, we recently discovered a novel islet incretin axis where glucagon‐like peptide‐1 regulates β‐cell production of another classic gut hormone, cholecystokinin. This axis is stimulated by obesity, and plays a role in enhancing β‐cell survival. In the present review, we place our observations in the wider context of the literature on incretin regulation in the islet, and discuss the potential for therapeutic targeting of these pathways.
Collapse
Affiliation(s)
- Amelia K Linnemann
- Department of Medicine Division of Endocrinology University of Wisconsin-Madison Madison Wisconsin USA
| | - Dawn Belt Davis
- Department of MedicineDivision of EndocrinologyUniversity of Wisconsin-MadisonMadisonWisconsinUSA; William S Middleton Memorial Veterans HospitalMadisonWisconsinUSA
| |
Collapse
|
22
|
Lavine JA, Kibbe CR, Baan M, Sirinvaravong S, Umhoefer HM, Engler KA, Meske LM, Sacotte KA, Erhardt DP, Davis DB. Cholecystokinin expression in the β-cell leads to increased β-cell area in aged mice and protects from streptozotocin-induced diabetes and apoptosis. Am J Physiol Endocrinol Metab 2015; 309:E819-28. [PMID: 26394663 PMCID: PMC4652070 DOI: 10.1152/ajpendo.00159.2015] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2015] [Accepted: 09/15/2015] [Indexed: 12/23/2022]
Abstract
Cholecystokinin (CCK) is a peptide hormone produced in the gut and brain with beneficial effects on digestion, satiety, and insulin secretion. CCK is also expressed in pancreatic β-cells, but only in models of obesity and insulin resistance. Whole body deletion of CCK in obese mice leads to reduced β-cell mass expansion and increased apoptosis. We hypothesized that islet-derived CCK is important in protection from β-cell apoptosis. To determine the specific role of β-cell-derived CCK in β-cell mass dynamics, we generated a transgenic mouse that expresses CCK in the β-cell in the lean state (MIP-CCK). Although this transgene contains the human growth hormone minigene, we saw no expression of human growth hormone protein in transgenic islets. We examined the ability of MIP-CCK mice to maintain β-cell mass when subjected to apoptotic stress, with advanced age, and after streptozotocin treatment. Aged MIP-CCK mice have increased β-cell area. MIP-CCK mice are resistant to streptozotocin-induced diabetes and exhibit reduced β-cell apoptosis. Directed CCK overexpression in cultured β-cells also protects from cytokine-induced apoptosis. We have identified an important new paracrine/autocrine effect of CCK in protection of β-cells from apoptotic stress. Understanding the role of β-cell CCK adds to the emerging knowledge of classic gut peptides in intraislet signaling. CCK receptor agonists are being investigated as therapeutics for obesity and diabetes. While these agonists clearly have beneficial effects on body weight and insulin sensitivity in peripheral tissues, they may also directly protect β-cells from apoptosis.
Collapse
Affiliation(s)
- Jeremy A Lavine
- School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin
| | - Carly R Kibbe
- Department of Medicine, Division of Endocrinology, University of Wisconsin-Madison, Madison, Wisconsin
| | - Mieke Baan
- Department of Medicine, Division of Endocrinology, University of Wisconsin-Madison, Madison, Wisconsin
| | - Sirinart Sirinvaravong
- Department of Medicine, Division of Endocrinology, University of Wisconsin-Madison, Madison, Wisconsin
| | - Heidi M Umhoefer
- Department of Medicine, Division of Endocrinology, University of Wisconsin-Madison, Madison, Wisconsin
| | - Kimberly A Engler
- Department of Medicine, Division of Endocrinology, University of Wisconsin-Madison, Madison, Wisconsin
| | - Louise M Meske
- Department of Medicine, Division of Endocrinology, University of Wisconsin-Madison, Madison, Wisconsin
| | - Kaitlyn A Sacotte
- Department of Medicine, Division of Endocrinology, University of Wisconsin-Madison, Madison, Wisconsin
| | - Daniel P Erhardt
- Department of Medicine, Division of Endocrinology, University of Wisconsin-Madison, Madison, Wisconsin
| | - Dawn Belt Davis
- Department of Medicine, Division of Endocrinology, University of Wisconsin-Madison, Madison, Wisconsin; Geriatric Research Education and Clinical Centers, William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin
| |
Collapse
|
23
|
Ning SL, Zheng WS, Su J, Liang N, Li H, Zhang DL, Liu CH, Dong JH, Zhang ZK, Cui M, Hu QX, Chen CC, Liu CH, Wang C, Pang Q, Chen YX, Yu X, Sun JP. Different downstream signalling of CCK1 receptors regulates distinct functions of CCK in pancreatic beta cells. Br J Pharmacol 2015; 172:5050-67. [PMID: 26248680 DOI: 10.1111/bph.13271] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Revised: 07/18/2015] [Accepted: 07/26/2015] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND AND PURPOSE Cholecystokinin (CCK) is secreted by intestinal I cells and regulates important metabolic functions. In pancreatic islets, CCK controls beta cell functions primarily through CCK1 receptors, but the signalling pathways downstream of these receptors in pancreatic beta cells are not well defined. EXPERIMENTAL APPROACH Apoptosis in pancreatic beta cell apoptosis was evaluated using Hoechst-33342 staining, TUNEL assays and Annexin-V-FITC/PI staining. Insulin secretion and second messenger production were monitored using ELISAs. Protein and phospho-protein levels were determined by Western blotting. A glucose tolerance test was carried out to examine the functions of CCK-8s in streptozotocin-induced diabetic mice. KEY RESULTS The sulfated carboxy-terminal octapeptide CCK26-33 amide (CCK-8s) activated CCK1 receptors and induced accumulation of both IP3 and cAMP. Whereas Gq -PLC-IP3 signalling was required for the CCK-8s-induced insulin secretion under low-glucose conditions, Gs -PKA/Epac signalling contributed more strongly to the CCK-8s-mediated insulin secretion in high-glucose conditions. CCK-8s also promoted formation of the CCK1 receptor/β-arrestin-1 complex in pancreatic beta cells. Using β-arrestin-1 knockout mice, we demonstrated that β-arrestin-1 is a key mediator of both CCK-8s-mediated insulin secretion and of its the protective effect against apoptosis in pancreatic beta cells. The anti-apoptotic effects of β-arrestin-1 occurred through cytoplasmic late-phase ERK activation, which activates the 90-kDa ribosomal S6 kinase-phospho-Bcl-2-family protein pathway. CONCLUSIONS AND IMPLICATIONS Knowledge of different CCK1 receptor-activated downstream signalling pathways in the regulation of distinct functions of pancreatic beta cells could be used to identify biased CCK1 receptor ligands for the development of new anti-diabetic drugs.
Collapse
Affiliation(s)
- Shang-lei Ning
- Department of Biochemistry and Molecular Biology and Key Laboratory Experimental Teratology of the Ministry of Education, Jinan, Shandong, China.,Qilu Hospital, Shandong University, Jinan, Shandong, China.,Department of Biochemistry and Molecular Biology, Shandong University School of Medicine, Jinan, Shandong, China
| | - Wen-shuai Zheng
- Shandong Provincial School Key laboratory for Protein Science of Chronic degenerative diseases, Jinan, Shandong, China.,Department of Physiology, Shandong University School of Medicine, Jinan, Shandong, China
| | - Jing Su
- Shandong Provincial School Key laboratory for Protein Science of Chronic degenerative diseases, Jinan, Shandong, China.,Department of Physiology, Shandong University School of Medicine, Jinan, Shandong, China
| | - Nan Liang
- Department of Biochemistry and Molecular Biology and Key Laboratory Experimental Teratology of the Ministry of Education, Jinan, Shandong, China.,Department of Biochemistry and Molecular Biology, Shandong University School of Medicine, Jinan, Shandong, China
| | - Hui Li
- Shandong Provincial School Key laboratory for Protein Science of Chronic degenerative diseases, Jinan, Shandong, China.,Department of Physiology, Shandong University School of Medicine, Jinan, Shandong, China
| | - Dao-lai Zhang
- Department of Biochemistry and Molecular Biology and Key Laboratory Experimental Teratology of the Ministry of Education, Jinan, Shandong, China.,Shandong Provincial School Key laboratory for Protein Science of Chronic degenerative diseases, Jinan, Shandong, China
| | - Chun-hua Liu
- Shandong Provincial School Key laboratory for Protein Science of Chronic degenerative diseases, Jinan, Shandong, China.,Department of Physiology, Shandong University School of Medicine, Jinan, Shandong, China
| | - Jun-hong Dong
- Department of Biochemistry and Molecular Biology and Key Laboratory Experimental Teratology of the Ministry of Education, Jinan, Shandong, China.,Department of Physiology, Shandong University School of Medicine, Jinan, Shandong, China
| | - Zheng-kui Zhang
- Department of Physiology, Shandong University School of Medicine, Jinan, Shandong, China
| | - Min Cui
- Department of Physiology, Shandong University School of Medicine, Jinan, Shandong, China
| | - Qiao-Xia Hu
- Department of Biochemistry and Molecular Biology and Key Laboratory Experimental Teratology of the Ministry of Education, Jinan, Shandong, China.,Department of Biochemistry and Molecular Biology, Shandong University School of Medicine, Jinan, Shandong, China
| | - Chao-chao Chen
- Shandong Provincial School Key laboratory for Protein Science of Chronic degenerative diseases, Jinan, Shandong, China.,Department of Physiology, Shandong University School of Medicine, Jinan, Shandong, China
| | - Chang-hong Liu
- Shandong Provincial Qianfoshan, Shandong University, Jinan, Shandong, China
| | - Chuan Wang
- Department of Pharmacology, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Qi Pang
- Shandong Provincial Hospital, Shandong University, Jinan, Shandong, China
| | - Yu-xin Chen
- Qilu Hospital, Shandong University, Jinan, Shandong, China
| | - Xiao Yu
- Department of Biochemistry and Molecular Biology and Key Laboratory Experimental Teratology of the Ministry of Education, Jinan, Shandong, China.,Qilu Hospital, Shandong University, Jinan, Shandong, China.,Shandong Provincial School Key laboratory for Protein Science of Chronic degenerative diseases, Jinan, Shandong, China.,Department of Physiology, Shandong University School of Medicine, Jinan, Shandong, China
| | - Jin-peng Sun
- Department of Biochemistry and Molecular Biology and Key Laboratory Experimental Teratology of the Ministry of Education, Jinan, Shandong, China.,Shandong Provincial School Key laboratory for Protein Science of Chronic degenerative diseases, Jinan, Shandong, China.,Department of Biochemistry and Molecular Biology, Shandong University School of Medicine, Jinan, Shandong, China.,Shandong Provincial Hospital, Shandong University, Jinan, Shandong, China
| |
Collapse
|
24
|
Rathmann W, Haastert B, Oscarsson J, Berglind N, Wareham NJ. Inverse association of HbA1c with faecal elastase 1 in people without diabetes. Pancreatology 2015; 15:620-5. [PMID: 26601880 DOI: 10.1016/j.pan.2015.09.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Revised: 09/28/2015] [Accepted: 09/29/2015] [Indexed: 12/11/2022]
Abstract
BACKGROUND/OBJECTIVES Faecal elastase 1 (FE1) was inversely correlated with diabetes duration and HbA1c in type 2 diabetes. The association of FE1 and HbA1c has not been investigated in people without diabetes. METHODS Type 2 diabetes patients (oral antidiabetic drugs or insulin: n = 391; medically untreated: n = 145) and matched (age, sex, practice) people without diabetes (n = 529) from general practices in Cambridgeshire (UK) were included. FE1 measurements (μg/g stool) were performed centrally (ScheBo-Tech Institute, Wettenberg, Germany). Linear regression models were fitted using FE1 as dependent variable and HbA1c, diabetes (no, untreated diabetes, treated diabetes) and interactions as independent variables. Potential confounders were sex, age, BMI, current alcohol consumption, smoking, triglycerides, and amylase. RESULTS In univariate linear regression models, HbA1c was significantly inversely related to FE1 in controls (β-coefficient: -108.74, p < 0.0001), whereas no significant associations were found for the diabetes groups. The inverse relationship of HbA1c with FE1 concentrations in people without diabetes persisted after adjusting for potential confounders in multivariate regression (β-coefficient: -109.18, p < 0.0001). In people without diabetes, there were lower FE1 concentrations among those with increased diabetes risk (HbA1c 5.7%-6.4% [38.8-46.4 mmol/mol]: 395 ± 204 μg/g vs. HbA1c ≤ 5.6% [≤37.7 mmol/mol]: 476 ± 219 μg/g; p < 0.0001). The prevalence of FE1<100 μg/g was significantly increased among persons with an HbA1c of 5.7%-6.4% (38.8-46.4 mmol/mol) compared with those with a normal HbA1c ≤ 5.6% (≤37.7 mmol/mol) (6.1% vs. 1.4%; p = 0.004). CONCLUSION/INTERPRETATION The present study suggests that pancreatic exocrine dysfunction might be an early disturbance that develops in parallel with hyperglycemia.
Collapse
Affiliation(s)
- Wolfgang Rathmann
- Institute for Biometrics and Epidemiology, German Diabetes Center, Düsseldorf, Germany.
| | | | | | | | | |
Collapse
|
25
|
Takebayashi K, Inukai T. Effect of proton pump inhibitors on glycemic control in patients with diabetes. World J Diabetes 2015; 6:1122-1131. [PMID: 26322158 PMCID: PMC4549663 DOI: 10.4239/wjd.v6.i10.1122] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Revised: 07/06/2015] [Accepted: 07/27/2015] [Indexed: 02/05/2023] Open
Abstract
Gastrin is a linear peptide hormone which is secreted mostly in the stomach pyloric antrum G cells. Although the main role of this hormone is the promotion of the secretion of gastric acid from the stomach parietal cells, gastrin can also behave as a growth factor and stimulate gastric cell proliferation. It is also reported that gastrin promotes β cell neogenesis in the pancreatic ductal complex, modest pancreatic β cell replication, and improvement of glucose tolerance in animal models, in which the remodeling of pancreatic tissues is promoted. These findings suggest the possibility that gastrin has the potential to promote an increase of β cell mass in pancreas, and therefore that gastrin may improve glucose tolerance. Proton pump inhibitors (PPIs) are wildly used clinically for the therapy of gastro-esophageal reflex disease, gastritis due to excess stomach acid, and gastric ulcers. PPIs indirectly elevate serum gastrin levels via a negative feedback effect. Recent evidence has revealed the beneficial effect of PPIs on glycemic control especially in patients with type 2 diabetes mellitus (T2DM), probably via the elevation of the levels of serum gastrin, although the detailed mechanism remains unclear. In addition, the beneficial effects of a combination therapy of gastrin or a PPI with a glucagon-like peptide-1 receptor agonist on glycemic control in animal models have been demonstrated. Although PPIs may be possible candidates for a new approach in the therapy of diabetes, a prospective, long-term, randomized, double-blind, placebo-controlled study is needed to establish the effect of PPIs on glycemic control in a large number of patients with T2DM.
Collapse
|
26
|
Stewart AF, Hussain MA, García-Ocaña A, Vasavada RC, Bhushan A, Bernal-Mizrachi E, Kulkarni RN. Human β-cell proliferation and intracellular signaling: part 3. Diabetes 2015; 64:1872-85. [PMID: 25999530 PMCID: PMC4439562 DOI: 10.2337/db14-1843] [Citation(s) in RCA: 108] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
This is the third in a series of Perspectives on intracellular signaling pathways coupled to proliferation in pancreatic β-cells. We contrast the large knowledge base in rodent β-cells with the more limited human database. With the increasing incidence of type 1 diabetes and the recognition that type 2 diabetes is also due in part to a deficiency of functioning β-cells, there is great urgency to identify therapeutic approaches to expand human β-cell numbers. Therapeutic approaches might include stem cell differentiation, transdifferentiation, or expansion of cadaver islets or residual endogenous β-cells. In these Perspectives, we focus on β-cell proliferation. Past Perspectives reviewed fundamental cell cycle regulation and its upstream regulation by insulin/IGF signaling via phosphatidylinositol-3 kinase/mammalian target of rapamycin signaling, glucose, glycogen synthase kinase-3 and liver kinase B1, protein kinase Cζ, calcium-calcineurin-nuclear factor of activated T cells, epidermal growth factor/platelet-derived growth factor family members, Wnt/β-catenin, leptin, and estrogen and progesterone. Here, we emphasize Janus kinase/signal transducers and activators of transcription, Ras/Raf/extracellular signal-related kinase, cadherins and integrins, G-protein-coupled receptors, and transforming growth factor β signaling. We hope these three Perspectives will serve to introduce these pathways to new researchers and will encourage additional investigators to focus on understanding how to harness key intracellular signaling pathways for therapeutic human β-cell regeneration for diabetes.
Collapse
Affiliation(s)
- Andrew F Stewart
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Mehboob A Hussain
- Departments of Medicine and Pediatrics, Johns Hopkins School of Medicine, Baltimore, MD
| | - Adolfo García-Ocaña
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Rupangi C Vasavada
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Anil Bhushan
- Diabetes Center, University of California, San Francisco, San Francisco, CA
| | - Ernesto Bernal-Mizrachi
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan, Ann Arbor, MI, and VA Ann Arbor Healthcare System, Ann Arbor, MI
| | - Rohit N Kulkarni
- Section of Islet Cell and Regenerative Biology, Joslin Diabetes Center, Harvard Medical School, Boston, MA
| |
Collapse
|
27
|
Linnemann AK, Neuman JC, Battiola TJ, Wisinski JA, Kimple ME, Davis DB. Glucagon-Like Peptide-1 Regulates Cholecystokinin Production in β-Cells to Protect From Apoptosis. Mol Endocrinol 2015; 29:978-87. [PMID: 25984632 DOI: 10.1210/me.2015-1030] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Cholecystokinin (CCK) is a classic gut hormone that is also expressed in the pancreatic islet, where it is highly up-regulated with obesity. Loss of CCK results in increased β-cell apoptosis in obese mice. Similarly, islet α-cells produce increased amounts of another gut peptide, glucagon-like peptide 1 (GLP-1), in response to cytokine and nutrient stimulation. GLP-1 also protects β-cells from apoptosis via cAMP-mediated mechanisms. Therefore, we hypothesized that the activation of islet-derived CCK and GLP-1 may be linked. We show here that both human and mouse islets secrete active GLP-1 as a function of body mass index/obesity. Furthermore, GLP-1 can rapidly stimulate β-cell CCK production and secretion through direct targeting by the cAMP-modulated transcription factor, cAMP response element binding protein (CREB). We find that cAMP-mediated signaling is required for Cck expression, but CCK regulation by cAMP does not require stimulatory levels of glucose or insulin secretion. We also show that CREB directly targets the Cck promoter in islets from obese (Leptin(ob/ob)) mice. Finally, we demonstrate that the ability of GLP-1 to protect β-cells from cytokine-induced apoptosis is partially dependent on CCK receptor signaling. Taken together, our work suggests that in obesity, active GLP-1 produced in the islet stimulates CCK production and secretion in a paracrine manner via cAMP and CREB. This intraislet incretin loop may be one mechanism whereby GLP-1 protects β-cells from apoptosis.
Collapse
Affiliation(s)
- Amelia K Linnemann
- Department of Medicine (A.K.L., T.J.B., J.A.W., M.E.K., D.B.D.), Division of Endocrinology, University of Wisconsin-Madison, Madison, Wisconsin 53705; Department of Nutritional Sciences (J.C.N.), University of Wisconsin-Madison, Madison, Wisconsin 53706; and William S. Middleton Memorial Veterans Hospital (D.B.D.), Madison, Wisconsin 53705
| | - Joshua C Neuman
- Department of Medicine (A.K.L., T.J.B., J.A.W., M.E.K., D.B.D.), Division of Endocrinology, University of Wisconsin-Madison, Madison, Wisconsin 53705; Department of Nutritional Sciences (J.C.N.), University of Wisconsin-Madison, Madison, Wisconsin 53706; and William S. Middleton Memorial Veterans Hospital (D.B.D.), Madison, Wisconsin 53705
| | - Therese J Battiola
- Department of Medicine (A.K.L., T.J.B., J.A.W., M.E.K., D.B.D.), Division of Endocrinology, University of Wisconsin-Madison, Madison, Wisconsin 53705; Department of Nutritional Sciences (J.C.N.), University of Wisconsin-Madison, Madison, Wisconsin 53706; and William S. Middleton Memorial Veterans Hospital (D.B.D.), Madison, Wisconsin 53705
| | - Jaclyn A Wisinski
- Department of Medicine (A.K.L., T.J.B., J.A.W., M.E.K., D.B.D.), Division of Endocrinology, University of Wisconsin-Madison, Madison, Wisconsin 53705; Department of Nutritional Sciences (J.C.N.), University of Wisconsin-Madison, Madison, Wisconsin 53706; and William S. Middleton Memorial Veterans Hospital (D.B.D.), Madison, Wisconsin 53705
| | - Michelle E Kimple
- Department of Medicine (A.K.L., T.J.B., J.A.W., M.E.K., D.B.D.), Division of Endocrinology, University of Wisconsin-Madison, Madison, Wisconsin 53705; Department of Nutritional Sciences (J.C.N.), University of Wisconsin-Madison, Madison, Wisconsin 53706; and William S. Middleton Memorial Veterans Hospital (D.B.D.), Madison, Wisconsin 53705
| | - Dawn Belt Davis
- Department of Medicine (A.K.L., T.J.B., J.A.W., M.E.K., D.B.D.), Division of Endocrinology, University of Wisconsin-Madison, Madison, Wisconsin 53705; Department of Nutritional Sciences (J.C.N.), University of Wisconsin-Madison, Madison, Wisconsin 53706; and William S. Middleton Memorial Veterans Hospital (D.B.D.), Madison, Wisconsin 53705
| |
Collapse
|
28
|
González-Ortiz M, Martínez-Abundis E, Mercado-Sesma AR, Álvarez-Carrillo R. Effect of pantoprazole on insulin secretion in drug-naïve patients with type 2 diabetes. Diabetes Res Clin Pract 2015; 108:e11-3. [PMID: 25704601 DOI: 10.1016/j.diabres.2015.01.039] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Revised: 01/14/2015] [Accepted: 01/29/2015] [Indexed: 02/09/2023]
Abstract
To evaluate the effect of pantoprazole during 45 days on insulin secretion in drug-naïve patients with type 2 diabetes, a randomized, double blind, placebo control clinical trial was performed in 14 drug-naïve volunteers. Significant increases in late insulin phase and total insulin secretion, and decreases in HbA1c levels were found.
Collapse
Affiliation(s)
- Manuel González-Ortiz
- Institute of Experimental and Clinical Therapeutics, Physiology Department, Health Science University Center, University of Guadalajara, Guadalajara, Mexico; Medical Research Unit in Clinical Epidemiology, Specialties Hospital, Medical Unit of High Specialty, West National Medical Center, Mexican Institute of Social Security, Guadalajara, Mexico.
| | - Esperanza Martínez-Abundis
- Institute of Experimental and Clinical Therapeutics, Physiology Department, Health Science University Center, University of Guadalajara, Guadalajara, Mexico
| | - Arieh R Mercado-Sesma
- Medical Research Unit in Clinical Epidemiology, Specialties Hospital, Medical Unit of High Specialty, West National Medical Center, Mexican Institute of Social Security, Guadalajara, Mexico
| | - Rebeca Álvarez-Carrillo
- Medical Research Unit in Clinical Epidemiology, Specialties Hospital, Medical Unit of High Specialty, West National Medical Center, Mexican Institute of Social Security, Guadalajara, Mexico
| |
Collapse
|
29
|
Coon SD, Rajendran VM, Schwartz JH, Singh SK. Glucose-dependent insulinotropic polypeptide-mediated signaling pathways enhance apical PepT1 expression in intestinal epithelial cells. Am J Physiol Gastrointest Liver Physiol 2015; 308:G56-62. [PMID: 25377315 PMCID: PMC4281688 DOI: 10.1152/ajpgi.00168.2014] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
We have shown recently that glucose-dependent insulinotropic polypeptide (GIP), but not glucagon-like peptide 1 (GLP-1) augments H(+) peptide cotransporter (PepT1)-mediated peptide absorption in murine jejunum. While we observed that inhibiting cAMP production decreased this augmentation of PepT1 activity by GIP, it was unclear whether PKA and/or other regulators of cAMP signaling pathway(s) were involved. This study utilized tritiated glycyl-sarcosine [(3)H-glycyl-sarcosine (Gly-Sar), a relatively nonhydrolyzable dipeptide] uptake to measure PepT1 activity in CDX2-transfected IEC-6 (IEC-6/CDX2) cells, an absorptive intestinal epithelial cell model. Similar to our earlier observations with mouse jejunum, GIP but not GLP-1 augmented Gly-Sar uptake (control vs. +GIP: 154 ± 22 vs. 454 ± 39 pmol/mg protein; P < 0.001) in IEC-6/CDX2 cells. Rp-cAMP (a PKA inhibitor) and wortmannin [phosophoinositide-3-kinase (PI3K) inhibitor] pretreatment completely blocked, whereas neither calphostin C (a potent PKC inhibitor) nor BAPTA (an intracellular Ca(2+) chelator) pretreatment affected the GIP-augmented Gly-Sar uptake in IEC-6/CDX2 cells. The downstream metabolites Epac (control vs. Epac agonist: 287 ± 22 vs. 711 ± 80 pmol/mg protein) and AKT (control vs. AKT inhibitor: 720 ± 50 vs. 75 ± 19 pmol/mg protein) were shown to be involved in GIP-augmented PepT1 activity as well. Western blot analyses revealed that both GIP and Epac agonist pretreatment enhance the PepT1 expression on the apical membranes, which is completely blocked by wortmannin in IEC-6/CDX2 cells. These observations demonstrate that both cAMP and PI3K signaling pathways augment GIP-induced peptide uptake through Epac and AKT-mediated pathways in intestinal epithelial cells, respectively. In addition, these observations also indicate that both Epac and AKT-mediated signaling pathways increase apical membrane expression of PepT1 in intestinal absorptive epithelial cells.
Collapse
Affiliation(s)
- Steven D. Coon
- 1Department of Medicine, Boston University School of Medicine, Boston, Massachusetts; ,2Department of Medicine, Boston Veterans Affairs Healthcare System, Boston, Massachusetts; ,3Department of Medicine, Boston University Clinical & Translational Science Institute, Boston, Massachusetts; and
| | - Vazhaikkurichi M. Rajendran
- 4Department of Biochemistry and Molecular Biology, West Virginia University School of Medicine, Morgantown, West Virginia
| | - John H. Schwartz
- 1Department of Medicine, Boston University School of Medicine, Boston, Massachusetts;
| | - Satish K. Singh
- 1Department of Medicine, Boston University School of Medicine, Boston, Massachusetts; ,2Department of Medicine, Boston Veterans Affairs Healthcare System, Boston, Massachusetts;
| |
Collapse
|
30
|
Comparative analysis of maple syrup to other natural sweeteners and evaluation of their metabolic responses in healthy rats. J Funct Foods 2014. [DOI: 10.1016/j.jff.2014.10.001] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
|
31
|
Mezza T, Kulkarni RN. The regulation of pre- and post-maturational plasticity of mammalian islet cell mass. Diabetologia 2014; 57:1291-303. [PMID: 24824733 DOI: 10.1007/s00125-014-3251-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2013] [Accepted: 03/24/2014] [Indexed: 12/17/2022]
Abstract
Regeneration of mature cells that produce functional insulin represents a major focus and a challenge of current diabetes research aimed at restoring beta cell mass in patients with most forms of diabetes, as well as in ageing. The capacity to adapt to diverse physiological states during life and the consequent ability to cope with increased metabolic demands in the normal regulation of glucose homeostasis is a distinctive feature of the endocrine pancreas in mammals. Both beta and alpha cells, and presumably other islet cells, are dynamically regulated via nutrient, neural and/or hormonal activation of growth factor signalling and the post-transcriptional modification of a variety of genes or via the microbiome to continually maintain a balance between regeneration (e.g. proliferation, neogenesis) and apoptosis. Here we review key regulators that determine islet cell mass at different ages in mammals. Understanding the chronobiology and the dynamics and age-dependent processes that regulate the relationship between the different cell types in the overall maintenance of an optimally functional islet cell mass could provide important insights into planning therapeutic approaches to counter and/or prevent the development of diabetes.
Collapse
Affiliation(s)
- Teresa Mezza
- Islet Cell Biology and Regenerative Medicine, Joslin Diabetes Center, 1 Joslin Place, Boston, MA, 02215, USA
| | | |
Collapse
|
32
|
Affiliation(s)
- Francesco Rubino
- Diabetes and Nutrition Science Division, King's College London, London, U.K.
| | - Stephanie A Amiel
- Diabetes and Nutrition Science Division, King's College London, London, U.K
| |
Collapse
|
33
|
Jia J, Liu X, Chen Y, Zheng X, Tu L, Huang X, Wang X. Establishment of a pancreatic β cell proliferation model in vitro and a platform for diabetes drug screening. Cytotechnology 2013; 66:687-97. [PMID: 23979319 DOI: 10.1007/s10616-013-9622-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Accepted: 07/19/2013] [Indexed: 01/13/2023] Open
Abstract
Diabetes, a disease resulting from loss of functional β cells, is globally an increasingly important condition. Based on the islet-differentiation ability of ductal epithelial cells and stimulating β cell proliferation ability of the Reg Iα gene, we aimed to establish an in vitro pancreatic β cell proliferation model for screening therapeutic drugs of diabetes in the future. Pancreatic ductal epithelial cells were isolated from male Wistar rats, and induced to differentiate into pancreatic β cells. Immunofluorescence staining assay, western blot, RT-PCR analysis, and dithizone staining were used to characterize the cells. Rat Reg Iα protein was transiently expressed in vitro by transfection of HEK 293 cells with the PCMV6-entry-REG Ia plasmid, and expression was verified by RT-PCR analysis, proliferation assay, and apoptosis assay. The pancreatic β cell proliferation model was further validated by a proliferation assay using differentiated pancreatic β cells treated with transfection supernatant. Finally, we have successfully established an in vitro pancreatic β cells proliferation model using transiently expressed rat Reg Iα protein and differentiated pancreatic β cells from pancreatic ductal epithelial cells. This model could be used as a platform to screen new drugs for islet neogenesis to cure diabetes, especially Chinese herbal drugs in the future.
Collapse
Affiliation(s)
- Jing Jia
- Center for Molecular Medicine, Zhejiang Academy of Medical Sciences, Hangzhou, 310013, Zhejiang Province, People's Republic of China
| | | | | | | | | | | | | |
Collapse
|
34
|
Stein J, Milewski WM, Dey A. The negative cell cycle regulators, p27(Kip1), p18(Ink4c), and GSK-3, play critical role in maintaining quiescence of adult human pancreatic β-cells and restrict their ability to proliferate. Islets 2013; 5:156-69. [PMID: 23896637 PMCID: PMC4049839 DOI: 10.4161/isl.25605] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Adult human pancreatic β-cells are primarily quiescent (G0) yet the mechanisms controlling their quiescence are poorly understood. Here, we demonstrate, by immunofluorescence and confocal microscopy, abundant levels of the critical negative cell cycle regulators, p27(Kip1) and p18(Ink4c), 2 key members of cyclin-dependent kinase (CDK) inhibitor family, and glycogen synthase kinase-3 (GSK-3), a serine-threonine protein kinase, in islet β-cells of adult human pancreatic tissue. Our data show that p27(Kip1) localizes primarily in β-cell nuclei, whereas, p18(Ink4c) is mostly present in β-cell cytosol. Additionally, p-p27(S10), a phosphorylated form of p27(Kip1), which was shown to interact with and to sequester cyclinD-CDK4/6 in the cytoplasm, is present in substantial amounts in β-cell cytosol. Our immunofluorescence analysis displays similar distribution pattern of p27(Kip1), p-p27(S10), p18(Ink4c) and GSK-3 in islet β-cells of adult mouse pancreatic tissue. We demonstrate marked interaction of p27(Kip1) with cyclin D3, an abundant D-type cyclin in adult human islets, and vice versa as well as with its cognate kinase partners, CDK4 and CDK6. Likewise, we show marked interaction of p18(Ink4c) with CDK4. The data collectively suggest that inhibition of CDK function by p27(Kip1) and p18(Ink4c) contributes to human β-cell quiescence. Consistent with this, we have found by BrdU incorporation assay that combined treatments of small molecule GSK-3 inhibitor and mitogen/s lead to elevated proliferation of human β-cells, which is caused partly due to p27(Kip1) downregulation. The results altogether suggest that ex vivo expansion of human β-cells is achievable via increased proliferation for β-cell replacement therapy in diabetes.
Collapse
Affiliation(s)
- Jeffrey Stein
- Section of Endocrinology; Diabetes and Metabolism; Department of Medicine; University of Chicago; Chicago, IL USA
| | - Wieslawa M Milewski
- Section of Endocrinology; Diabetes and Metabolism; Department of Medicine; University of Chicago; Chicago, IL USA
| | - Arunangsu Dey
- Section of Endocrinology; Diabetes and Metabolism; Department of Medicine; University of Chicago; Chicago, IL USA
- College of Medicine; Department of Biochemistry and Molecular Genetics; University of Illinois at Chicago; Chicago, IL USA
- Correspondence to: Arunangsu Dey,
| |
Collapse
|
35
|
Ravassa S, Zudaire A, Díez J. Glucagon-like peptide 1 and cardiac cell survival. ACTA ACUST UNITED AC 2012; 59:561-9. [PMID: 23031433 DOI: 10.1016/j.endonu.2012.07.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2012] [Revised: 07/05/2012] [Accepted: 07/10/2012] [Indexed: 12/25/2022]
Abstract
During myocardial infarction (MI), a variety of mechanisms contribute to activation of cell death processes in cardiomyocytes, which determines the final MI size, subsequent mortality, and post-MI remodeling. The deleterious mechanisms activated during the ischemia and reperfusion phases in MI include oxygen deprival, decreased availability of nutrients and survival factors, accumulation of waste products, generation of oxygen free radicals, calcium overload, neutrophil infiltration in the ischemic area, depletion of energy stores, and opening of the mitochondrial permeability transition pore, all of them contributing to activation of apoptosis and necrosis in cardiomyocytes. Glucagon-like peptide-1 [GLP-1 (7-36) amide] has gained relevance in recent years for metabolic treatment of patients with type 2 diabetes mellitus. Cytoprotection of different cell types, including cardiomyocytes, is among the pleiotropic actions reported for GLP-1. This paper reviews the most relevant experimental studies that have contributed to a better understanding of the molecular mechanisms and intracellular pathways involved in cardioprotection induced by GLP-1 and analyzes in depth its potential role as a therapeutic target both in the ischemic and reperfused myocardium and in other conditions that are associated with myocardial remodeling and heart failure.
Collapse
Affiliation(s)
- Susana Ravassa
- Área de Ciencias Cardiovasculares, Centro para la Investigación Médica Aplicada, Universidad de Navarra, Pamplona, España.
| | | | | |
Collapse
|
36
|
Sam AH, Gunner DJ, King A, Persaud SJ, Brooks L, Hostomska K, Ford HE, Liu B, Ghatei MA, Bloom SR, Bewick GA. Selective ablation of peptide YY cells in adult mice reveals their role in beta cell survival. Gastroenterology 2012; 143:459-68. [PMID: 22562022 DOI: 10.1053/j.gastro.2012.04.047] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2011] [Revised: 03/31/2012] [Accepted: 04/24/2012] [Indexed: 12/29/2022]
Abstract
BACKGROUND AND AIMS In the pancreas, peptide YY (PYY) is expressed by a subpopulation of nonbeta cells in the islets of Langerhans. We investigated the function of these cells in the pancreas of adult mice. METHODS We generated mice in which administration of diphtheria toxin (DT) led to specific ablation of PYY-expressing cells. We investigated the effects of loss of PYY cells on glucose homeostasis. RESULTS Loss of PYY cells in adult mice resulted in severe hyperglycemia, which was associated with significant loss of pancreatic insulin and disruption of islet morphology. In vitro administration of DT to isolated islets significantly reduced numbers of PYY-expressing cells and levels of insulin. Administration of either pancreatic polypeptide (a strong agonist of the receptor Y(4)) or PYY(3-36) (a selective agonist of the receptor Y(2)) did not restore loss of pancreatic insulin following administration of DT. However, a long-acting PYY analogue reduced the loss of insulin, and administration of this analogue reduced the hyperglycemia and insulin loss induced by streptozotocin in mice. CONCLUSIONS PYY appears to regulate beta cell function and survival via the receptor Y(1/2). These findings might be developed to treat and prevent loss of beta cells in patients with diabetes mellitus.
Collapse
|
37
|
Andersson O, Adams BA, Yoo D, Ellis GC, Gut P, Anderson RM, German MS, Stainier DYR. Adenosine signaling promotes regeneration of pancreatic β cells in vivo. Cell Metab 2012; 15:885-94. [PMID: 22608007 PMCID: PMC3372708 DOI: 10.1016/j.cmet.2012.04.018] [Citation(s) in RCA: 149] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2011] [Revised: 02/07/2012] [Accepted: 04/18/2012] [Indexed: 11/29/2022]
Abstract
Diabetes can be controlled with insulin injections, but a curative approach that restores the number of insulin-producing β cells is still needed. Using a zebrafish model of diabetes, we screened ~7,000 small molecules to identify enhancers of β cell regeneration. The compounds we identified converge on the adenosine signaling pathway and include exogenous agonists and compounds that inhibit degradation of endogenously produced adenosine. The most potent enhancer of β cell regeneration was the adenosine agonist 5'-N-ethylcarboxamidoadenosine (NECA), which, acting through the adenosine receptor A2aa, increased β cell proliferation and accelerated restoration of normoglycemia in zebrafish. Despite markedly stimulating β cell proliferation during regeneration, NECA had only a modest effect during development. The proliferative and glucose-lowering effect of NECA was confirmed in diabetic mice, suggesting an evolutionarily conserved role for adenosine in β cell regeneration. With this whole-organism screen, we identified components of the adenosine pathway that could be therapeutically targeted for the treatment of diabetes.
Collapse
Affiliation(s)
- Olov Andersson
- Department of Biochemistry and Biophysics, Program in Developmental and Stem Cell Biology and Program in Genetics and Human Genetics, Diabetes Center, Institute for Regeneration Medicine and Liver Center, University of California, San Francisco, 1550 4th Street, San Francisco, CA 94158, USA.
| | | | | | | | | | | | | | | |
Collapse
|
38
|
Karadimos MJ, Kapoor A, El Khattabi I, Sharma A. β-cell preservation and regeneration for diabetes treatment: where are we now? ACTA ACUST UNITED AC 2012; 2:213-222. [PMID: 23049620 DOI: 10.2217/dmt.12.21] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Over the last decade, our knowledge of β-cell biology has expanded with the use of new scientific techniques and strategies. Growth factors, hormones and small molecules have been shown to enhance β-cell proliferation and function. Stem cell technology and research into the developmental biology of the pancreas have yielded new methods for in vivo and in vitro regeneration of β cells from stem cells and endogenous progenitors as well as transdifferentiation of non-β cells. Novel pharmacological approaches have been developed to preserve and enhance β-cell function. Strategies to increase expression of insulin gene transcription factors in dysfunctional and immature β cells have ameliorated these impairments. Hence, we suggest that strategies to minimize β-cell loss and to increase their function and regeneration will ultimately lead to therapy for both Type 1 and 2 diabetes.
Collapse
Affiliation(s)
- Michael J Karadimos
- Section of Islet Cell & Regenerative Biology, Joslin Diabetes Center, Boston, MA 02215, USA ; Department of Medicine, Harvard Medical School, Boston, MA 02215, USA
| | | | | | | |
Collapse
|
39
|
Abstract
During myocardial infarction (MI), a variety of mechanisms contribute to the activation of cell death processes in cardiomyocytes, determining the final MI size, subsequent mortality, and post-MI remodelling. The deleterious mechanisms accompanying the ischaemic and reperfusion phases in MI include deprivation of oxygen, nutrients, and survival factors, accumulation of waste products, generation of oxygen free radicals, calcium overload, neutrophil infiltration of the ischaemic area, depletion of energy stores, and opening of the mitochondrial permeability transition pore, all of which contribute to the activation of apoptosis and necrosis in cardiomyocytes. During the last few years, glucagon-like peptide-1 (GLP-1) (7-36)-based therapeutic strategies have been incorporated into the treatment of patients with type 2 diabetes mellitus. Cytoprotection is among the pleiotropic actions described for GLP-1 in different cell types, including cardiomyocytes. This paper reviews the most relevant experimental and clinical studies that have contributed to a better understanding of the molecular mechanisms and intracellular pathways involved in the cardioprotection induced by GLP-1, analysing in depth its potential role as a therapeutic target in the ischaemic and reperfused myocardium as well as in other pathologies that are associated with myocardial remodelling and heart failure.
Collapse
|
40
|
Kuse M, Wang YF, Kalasannavar V, Khan M, Rajpoot N. Local isotropic phase symmetry measure for detection of beta cells and lymphocytes. J Pathol Inform 2012; 2:S2. [PMID: 22811958 PMCID: PMC3312708 DOI: 10.4103/2153-3539.92028] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2011] [Accepted: 10/20/2011] [Indexed: 11/04/2022] Open
Abstract
Diabetes can be associated with a reduction in functional β cell mass, which must be restored if the disease is to be cured or progress is to be arrested. To study the cell count, it is also necessary to determine the number of nuclei within the insulin stained area. It can take a single experimentalist several months to complete a single study of this kind, results of which may still be quite subjective. In this paper, we propose a framework based on a novel measure of local symmetry for detection of cells. The local isotropic phase symmetry measure (LIPSyM) is designed to give high values at or near the cell centers. We demonstrate the effectiveness of our algorithm for detection of two types of specific cells in histology images, cells in mouse pancreatic sections and lymphocytes in human breast tissue. Experimental results for these two problems show that our algorithm performs better than human experts for the former problem, and outperforms the best reported results for the latter.
Collapse
Affiliation(s)
- Manohar Kuse
- The LNM Institute of Information Technology, Jaipur, India
| | - Yi-Fang Wang
- School of Life Sciences, University of Warwick, Coventry, UK
| | | | - Michael Khan
- School of Life Sciences, University of Warwick, Coventry, UK
| | - Nasir Rajpoot
- Department of Computer Science, University of Warwick, Coventry, UK
| |
Collapse
|
41
|
Abstract
Abstract The endocrine cells of the gastrointestinal (GI) tract and the pancreas, referred to as the enteroendocrine cells, secrete a large variety of peptides and amines that regulate functions of the digestive tract itself and of distant organs. Taken together, the enteroendocrine cells form the largest system of endocrine cells in the body, presently comprising 16 cell types. Many of them have been named after letters of the alphabet, but the names are only occasionally related to morphological or functional characteristics of the cell. In this review of the normal, adult, mammalian enteroendocrine cells, we summarize synonyms, functions, locations, structure, stored hormones/amines, receptors, and other cellular expressions. We propose that the enteroendocrine cells should be renamed after their most well-known hormone/amine and, when applicable, their anatomical location, with opportunities for future revisions.
Collapse
Affiliation(s)
- Herbert F Helander
- Department of Gastrosurgical Research and Education, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
| | | |
Collapse
|
42
|
Aston-Mourney K, Hull RL, Zraika S, Udayasankar J, Subramanian SL, Kahn SE. Exendin-4 increases islet amyloid deposition but offsets the resultant beta cell toxicity in human islet amyloid polypeptide transgenic mouse islets. Diabetologia 2011; 54:1756-65. [PMID: 21484213 PMCID: PMC3220951 DOI: 10.1007/s00125-011-2143-3] [Citation(s) in RCA: 49] [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: 01/14/2011] [Accepted: 03/17/2011] [Indexed: 12/14/2022]
Abstract
AIMS/HYPOTHESIS In type 2 diabetes, aggregation of islet amyloid polypeptide (IAPP) into amyloid is associated with beta cell loss. As IAPP is co-secreted with insulin, we hypothesised that IAPP secretion is necessary for amyloid formation and that treatments that increase insulin (and IAPP) secretion would thereby increase amyloid formation and toxicity. We also hypothesised that the unique properties of the glucagon-like peptide-1 (GLP-1) receptor agonist exendin-4 to maintain or increase beta cell mass would offset the amyloid-induced toxicity. METHODS Islets from amyloid-forming human IAPP transgenic and control non-transgenic mice were cultured for 48 h in 16.7 mmol/l glucose alone (control) or with exendin-4, potassium chloride (KCl), diazoxide or somatostatin. Human IAPP and insulin release, amyloid deposition, beta cell area/islet area, apoptosis and AKT phosphorylation levels were determined. RESULTS In control human IAPP transgenic islets, amyloid formation was associated with increased beta cell apoptosis and beta cell loss. Increasing human IAPP release with exendin-4 or KCl increased amyloid deposition. However, while KCl further increased beta cell apoptosis and beta cell loss, exendin-4 did not. Conversely, decreasing human IAPP release with diazoxide or somatostatin limited amyloid formation and its toxic effects. Treatment with exendin-4 was associated with an increase in AKT phosphorylation compared with control and KCl-treated islets. CONCLUSIONS/INTERPRETATION IAPP release is necessary for islet amyloid formation and its toxic effects. Thus, use of insulin secretagogues to treat type 2 diabetes may result in increased islet amyloidogenesis and beta cell death. However, the AKT-associated anti-apoptotic effects of GLP-1 receptor agonists such as exendin-4 may limit the toxic effects of increased islet amyloid.
Collapse
Affiliation(s)
- K Aston-Mourney
- Division of Metabolism, Endocrinology and Nutrition, VA Puget Sound Health Care System (151), 1660 South Columbian Way, Seattle, WA 98108, USA.
| | | | | | | | | | | |
Collapse
|
43
|
Hormonal status and regulation of glycemia in neonatal calves during the first hours of postnatal life. ACTA VETERINARIA 2011. [DOI: 10.2298/avb1104349k] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|