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Filipowska J, Cisneros Z, Leon-Rivera N, Wang P, Kang R, Lu G, Yuan YC, Bhattacharya S, Dhawan S, Garcia-Ocaña A, Kondegowda NG, Vasavada RC. LGR4 is essential for maintaining β-cell homeostasis through suppression of RANK. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.10.593645. [PMID: 38798561 PMCID: PMC11118322 DOI: 10.1101/2024.05.10.593645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Pancreatic β-cell stress contributes to diabetes progression. This study demonstrates that Leucine-rich repeat-containing G-protein-coupled-receptor-4 (LGR4) is critical for maintaining β-cell health and is modulated by stressors. In vitro , Lgr4 knockdown decreases proliferation and survival in rodent β-cells, while overexpression protects against cytokine-induced cell death in rodent and human β-cells. Mechanistically, LGR4 suppresses Receptor Activator of Nuclear Factor Kappa B (NFκB) (RANK) and its subsequent activation of NFκB to protect β-cells. β-cell-specific Lgr4 -conditional knockout (cko) mice exhibit normal glucose homeostasis but increased β-cell death in both sexes and decreased proliferation only in females. Male Lgr4 cko mice under stress display reduced β-cell proliferation and a further increase in β-cell death. Upon aging, both male and female Lgr4 cko mice display impaired β-cell homeostasis, however, only female mice are glucose intolerant with decreased plasma insulin. We show that LGR4 is required for maintaining β-cell health under basal and stress-induced conditions, through suppression of RANK. Teaser LGR4 receptor is critical for maintaining β-cell health under basal and stressed conditions, through suppression of RANK.
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Bourgeois S, Coenen S, Degroote L, Willems L, Van Mulders A, Pierreux J, Heremans Y, De Leu N, Staels W. Harnessing beta cell regeneration biology for diabetes therapy. Trends Endocrinol Metab 2024:S1043-2760(24)00082-1. [PMID: 38644094 DOI: 10.1016/j.tem.2024.03.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2024] [Revised: 03/21/2024] [Accepted: 03/21/2024] [Indexed: 04/23/2024]
Abstract
The pandemic scale of diabetes mellitus is alarming, its complications remain devastating, and current treatments still pose a major burden on those affected and on the healthcare system as a whole. As the disease emanates from the destruction or dysfunction of insulin-producing pancreatic β-cells, a real cure requires their restoration and protection. An attractive strategy is to regenerate β-cells directly within the pancreas; however, while several approaches for β-cell regeneration have been proposed in the past, clinical translation has proven challenging. This review scrutinizes recent findings in β-cell regeneration and discusses their potential clinical implementation. Hereby, we aim to delineate a path for innovative, targeted therapies to help shift from 'caring for' to 'curing' diabetes.
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Affiliation(s)
- Stephanie Bourgeois
- Genetics, Reproduction, and Development (GRAD), Beta Cell Neogenesis (BENE) Research Unit, Vrije Universiteit Brussel (VUB), 1090 Brussels, Belgium
| | - Sophie Coenen
- Genetics, Reproduction, and Development (GRAD), Beta Cell Neogenesis (BENE) Research Unit, Vrije Universiteit Brussel (VUB), 1090 Brussels, Belgium
| | - Laure Degroote
- Genetics, Reproduction, and Development (GRAD), Beta Cell Neogenesis (BENE) Research Unit, Vrije Universiteit Brussel (VUB), 1090 Brussels, Belgium
| | - Lien Willems
- Genetics, Reproduction, and Development (GRAD), Beta Cell Neogenesis (BENE) Research Unit, Vrije Universiteit Brussel (VUB), 1090 Brussels, Belgium
| | - Annelore Van Mulders
- Genetics, Reproduction, and Development (GRAD), Beta Cell Neogenesis (BENE) Research Unit, Vrije Universiteit Brussel (VUB), 1090 Brussels, Belgium
| | - Julie Pierreux
- Genetics, Reproduction, and Development (GRAD), Beta Cell Neogenesis (BENE) Research Unit, Vrije Universiteit Brussel (VUB), 1090 Brussels, Belgium
| | - Yves Heremans
- Genetics, Reproduction, and Development (GRAD), Beta Cell Neogenesis (BENE) Research Unit, Vrije Universiteit Brussel (VUB), 1090 Brussels, Belgium
| | - Nico De Leu
- Genetics, Reproduction, and Development (GRAD), Beta Cell Neogenesis (BENE) Research Unit, Vrije Universiteit Brussel (VUB), 1090 Brussels, Belgium; Endocrinology, Universiteit Ziekenhuis Brussel (UZ Brussel), 1090 Brussels, Belgium; Endocrinology, ASZ Aalst, 9300 Aalst, Belgium.
| | - Willem Staels
- Genetics, Reproduction, and Development (GRAD), Beta Cell Neogenesis (BENE) Research Unit, Vrije Universiteit Brussel (VUB), 1090 Brussels, Belgium; Pediatric Endocrinology, Department of Pediatrics, KidZ Health Castle, Universiteit Ziekenhuis Brussel (UZ Brussel), 1090 Brussels, Belgium.
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3
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Silva IBB, Kimura CH, Colantoni VP, Sogayar MC. Stem cells differentiation into insulin-producing cells (IPCs): recent advances and current challenges. Stem Cell Res Ther 2022; 13:309. [PMID: 35840987 PMCID: PMC9284809 DOI: 10.1186/s13287-022-02977-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2021] [Accepted: 06/19/2022] [Indexed: 11/10/2022] Open
Abstract
Type 1 diabetes mellitus (T1D) is a chronic disease characterized by an autoimmune destruction of insulin-producing β-pancreatic cells. Although many advances have been achieved in T1D treatment, current therapy strategies are often unable to maintain perfect control of glycemic levels. Several studies are searching for new and improved methodologies for expansion of β-cell cultures in vitro to increase the supply of these cells for pancreatic islets replacement therapy. A promising approach consists of differentiation of stem cells into insulin-producing cells (IPCs) in sufficient number and functional status to be transplanted. Differentiation protocols have been designed using consecutive cytokines or signaling modulator treatments, at specific dosages, to activate or inhibit the main signaling pathways that control the differentiation of induced pluripotent stem cells (iPSCs) into pancreatic β-cells. Here, we provide an overview of the current approaches and achievements in obtaining stem cell-derived β-cells and the numerous challenges, which still need to be overcome to achieve this goal. Clinical translation of stem cells-derived β-cells for efficient maintenance of long-term euglycemia remains a major issue. Therefore, research efforts have been directed to the final steps of in vitro differentiation, aiming at production of functional and mature β-cells and integration of interdisciplinary fields to generate efficient cell therapy strategies capable of reversing the clinical outcome of T1D.
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Affiliation(s)
- Isaura Beatriz Borges Silva
- Cell and Molecular Therapy Center (NUCEL), School of Medicine, University of São Paulo, São Paulo, SP, 05360-130, Brazil.,Department of Biochemistry, Chemistry Institute, University of São Paulo, São Paulo, SP, 05508-000, Brazil
| | - Camila Harumi Kimura
- Cell and Molecular Therapy Center (NUCEL), School of Medicine, University of São Paulo, São Paulo, SP, 05360-130, Brazil
| | - Vitor Prado Colantoni
- Cell and Molecular Therapy Center (NUCEL), School of Medicine, University of São Paulo, São Paulo, SP, 05360-130, Brazil.,Department of Biochemistry, Chemistry Institute, University of São Paulo, São Paulo, SP, 05508-000, Brazil
| | - Mari Cleide Sogayar
- Cell and Molecular Therapy Center (NUCEL), School of Medicine, University of São Paulo, São Paulo, SP, 05360-130, Brazil. .,Department of Biochemistry, Chemistry Institute, University of São Paulo, São Paulo, SP, 05508-000, Brazil.
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4
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Salazar-Petres ER, Sferruzzi-Perri AN. Pregnancy-induced changes in β-cell function: what are the key players? J Physiol 2021; 600:1089-1117. [PMID: 33704799 DOI: 10.1113/jp281082] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Accepted: 02/17/2021] [Indexed: 12/11/2022] Open
Abstract
Maternal metabolic adaptations during pregnancy ensure appropriate nutrient supply to the developing fetus. This is facilitated by reductions in maternal peripheral insulin sensitivity, which enables glucose to be available in the maternal circulation for transfer to the fetus for growth. To balance this process and avoid excessive hyperglycaemia and glucose intolerance in the mother during pregnancy, maternal pancreatic β-cells undergo remarkable changes in their function including increasing their proliferation and glucose-stimulated insulin secretion. In this review we examine how placental and maternal hormones work cooperatively to activate several signalling pathways, transcription factors and epigenetic regulators to drive adaptations in β-cell function during pregnancy. We also explore how adverse maternal environmental conditions, including malnutrition, obesity, circadian rhythm disruption and environmental pollutants, may impact the endocrine and molecular mechanisms controlling β-cell adaptations during pregnancy. The available data from human and experimental animal studies highlight the need to better understand how maternal β-cells integrate the various environmental, metabolic and endocrine cues and thereby determine appropriate β-cell adaptation during gestation. In doing so, these studies may identify targetable pathways that could be used to prevent not only the development of pregnancy complications like gestational diabetes that impact maternal and fetal wellbeing, but also more generally the pathogenesis of other metabolic conditions like type 2 diabetes.
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Affiliation(s)
- Esteban Roberto Salazar-Petres
- Centre for Trophoblast Research, Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge, CB2 3EG, UK
| | - Amanda Nancy Sferruzzi-Perri
- Centre for Trophoblast Research, Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge, CB2 3EG, UK
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5
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Li H, Park HM, Ji HS, Han J, Kim SK, Park HY, Jeong TS. Phenolic-enriched blueberry-leaf extract attenuates glucose homeostasis, pancreatic β-cell function, and insulin sensitivity in high-fat diet–induced diabetic mice. Nutr Res 2020; 73:83-96. [DOI: 10.1016/j.nutres.2019.09.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 09/11/2019] [Accepted: 09/16/2019] [Indexed: 12/26/2022]
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6
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Levasseur EM, Yamada K, Piñeros AR, Wu W, Syed F, Orr KS, Anderson-Baucum E, Mastracci TL, Maier B, Mosley AL, Liu Y, Bernal-Mizrachi E, Alonso LC, Scott D, Garcia-Ocaña A, Tersey SA, Mirmira RG. Hypusine biosynthesis in β cells links polyamine metabolism to facultative cellular proliferation to maintain glucose homeostasis. Sci Signal 2019; 12:eaax0715. [PMID: 31796630 PMCID: PMC7202401 DOI: 10.1126/scisignal.aax0715] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Deoxyhypusine synthase (DHPS) uses the polyamine spermidine to catalyze the hypusine modification of the mRNA translation factor eIF5A and promotes oncogenesis through poorly defined mechanisms. Because germline deletion of Dhps is embryonically lethal, its role in normal postnatal cellular function in vivo remains unknown. We generated a mouse model that enabled the inducible, postnatal deletion of Dhps specifically in postnatal islet β cells, which function to maintain glucose homeostasis. Removal of Dhps did not have an effect under normal physiologic conditions. However, upon development of insulin resistance, which induces β cell proliferation, Dhps deletion caused alterations in proteins required for mRNA translation and protein secretion, reduced production of the cell cycle molecule cyclin D2, impaired β cell proliferation, and induced overt diabetes. We found that hypusine biosynthesis was downstream of protein kinase C-ζ and was required for c-Myc-induced proliferation. Our studies reveal a requirement for DHPS in β cells to link polyamines to mRNA translation to effect facultative cellular proliferation and glucose homeostasis.
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Affiliation(s)
- Esther M Levasseur
- Center for Diabetes and Metabolic Diseases, Indiana University School of Medicine, Indianapolis, IN 46202, USA
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Kentaro Yamada
- Center for Diabetes and Metabolic Diseases, Indiana University School of Medicine, Indianapolis, IN 46202, USA
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Annie R Piñeros
- Center for Diabetes and Metabolic Diseases, Indiana University School of Medicine, Indianapolis, IN 46202, USA
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Wenting Wu
- Center for Diabetes and Metabolic Diseases, Indiana University School of Medicine, Indianapolis, IN 46202, USA
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Farooq Syed
- Center for Diabetes and Metabolic Diseases, Indiana University School of Medicine, Indianapolis, IN 46202, USA
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Kara S Orr
- Center for Diabetes and Metabolic Diseases, Indiana University School of Medicine, Indianapolis, IN 46202, USA
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | | | - Teresa L Mastracci
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
- Indiana Biosciences Research Institute, Indianapolis, IN 46202, USA
| | - Bernhard Maier
- Department of Medicine, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Amber L Mosley
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Yunlong Liu
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | | | - Laura C Alonso
- Department of Medicine, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Donald Scott
- Diabetes, Obesity, and Metabolism Institute and the Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Adolfo Garcia-Ocaña
- Diabetes, Obesity, and Metabolism Institute and the Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Sarah A Tersey
- Center for Diabetes and Metabolic Diseases, Indiana University School of Medicine, Indianapolis, IN 46202, USA
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Raghavendra G Mirmira
- Center for Diabetes and Metabolic Diseases, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN 46202, USA
- Department of Medicine, Indiana University School of Medicine, Indianapolis, IN 46202, USA
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7
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Banerjee RR. Piecing together the puzzle of pancreatic islet adaptation in pregnancy. Ann N Y Acad Sci 2019; 1411:120-139. [PMID: 29377199 DOI: 10.1111/nyas.13552] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Revised: 10/18/2017] [Accepted: 10/24/2017] [Indexed: 12/20/2022]
Abstract
Pregnancy places acute demands on maternal physiology, including profound changes in glucose homeostasis. Gestation is characterized by an increase in insulin resistance, counterbalanced by an adaptive increase in pancreatic β cell production of insulin. Failure of normal adaptive responses of the islet to increased maternal and fetal demands manifests as gestational diabetes mellitus (GDM). The gestational changes and rapid reversal of islet adaptations following parturition are at least partly driven by an anticipatory program rather than post-factum compensatory adaptations. Here, I provide a comprehensive review of the cellular and molecular mechanisms underlying normal islet adaptation during pregnancy and how dysregulation may lead to GDM. Emerging areas of interest and understudied areas worthy of closer examination in the future are highlighted.
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Affiliation(s)
- Ronadip R Banerjee
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, and the Comprehensive Diabetes Center, University of Alabama at Birmingham School of Medicine, Birmingham, Alabama
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8
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Lin CM, Titchenell PM, Keil JM, Garcia-Ocaña A, Bolinger MT, Abcouwer SF, Antonetti DA. Inhibition of Atypical Protein Kinase C Reduces Inflammation-Induced Retinal Vascular Permeability. THE AMERICAN JOURNAL OF PATHOLOGY 2018; 188:2392-2405. [PMID: 30220554 DOI: 10.1016/j.ajpath.2018.06.020] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Revised: 06/01/2018] [Accepted: 06/13/2018] [Indexed: 01/14/2023]
Abstract
Changes in permeability of retinal blood vessels contribute to macular edema and the pathophysiology of numerous ocular diseases, including diabetic retinopathy, retinal vein occlusions, and macular degeneration. Vascular endothelial growth factor (VEGF) induces retinal permeability and macular thickening in these diseases. However, inflammatory agents, such as tumor necrosis factor-α (TNF-α), also may drive vascular permeability, specifically in patients unresponsive to anti-VEGF therapy. Recent evidence suggests VEGF and TNF-α induce permeability through distinct mechanisms; however, both require the activation of atypical protein kinase C (aPKC). We provide evidence, using genetic mouse models and therapeutic intervention with small molecules, that inhibition of aPKC prevented or reduced vascular permeability in animal models of retinal inflammation. Expression of a kinase-dead aPKC transgene, driven by a vascular and hematopoietic restricted promoter, reduced retinal vascular permeability in an ischemia-reperfusion model of retinal injury. This effect was recapitulated with a small-molecule inhibitor of aPKC. Expression of the kinase-dead aPKC transgene dramatically reduced the expression of inflammatory factors and blocked the attraction of inflammatory monocytes and granulocytes after ischemic injury. Coinjection of VEGF with TNF-α was sufficient to induce permeability, edema, and retinal inflammation, and treatment with an aPKC inhibitor prevented VEGF/TNF-α-induced permeability. These data suggest that aPKC contributes to inflammation-driven retinal vascular pathology and may be an attractive target for therapeutic intervention.
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Affiliation(s)
- Cheng-Mao Lin
- Kellogg Eye Center, Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan
| | - Paul M Titchenell
- The Institute for Diabetes, Obesity and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Jason M Keil
- Molecular and Behavioral Neuroscience Institute, Department of Human Genetics and Medical Scientist Training Program, University of Michigan, Ann Arbor, Michigan
| | - Adolfo Garcia-Ocaña
- Diabetes, Obesity and Metabolism Institute, Division of Endocrinology, Diabetes and Bone Diseases, The Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Mark T Bolinger
- Kellogg Eye Center, Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan
| | - Steven F Abcouwer
- Kellogg Eye Center, Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan
| | - David A Antonetti
- Kellogg Eye Center, Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan.
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10
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Yeo MK, Kim JY, Seong IO, Kim JM, Kim KH. Phosphorylated Protein Kinase C (Zeta/Lambda) Expression in Colorectal Adenocarcinoma and Its Correlation with Clinicopathologic Characteristics and Prognosis. J Cancer 2017; 8:3371-3377. [PMID: 29158810 PMCID: PMC5665054 DOI: 10.7150/jca.20983] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Accepted: 08/29/2017] [Indexed: 12/29/2022] Open
Abstract
Background: Protein kinase C zeta/lambda (PKCζ/λ) is a family of protein kinase enzymes that contributes to cell proliferation and regulation, which are important for cancer development. PKCζ/λ has been shown to be an important regulator of tumorigenesis in intestinal cancer. The phosphorylated form of PKCζ/λ, p-PKCζ/λ, is suggested as an active form of PKCζ/λ. However, p-PKCζ/λ expression and its clinicopathologic implication in colorectal adenocarcinoma (CRAC) are unclear. Methods: Seven whole-tissue sections of malignant polyps containing both non-neoplastic and neoplastic mucosa, 11 adenomas with low-grade dysplasia, and 173 CRACs were examined by immunohistochemistry and western blot assay for p-PKCζ/λ protein expression. The association of p-PKCζ/λ expression with clinicopathologic factors including patient survival was studied. Results: In non-neoplastic epithelia, p-PKCζ/λ showed a weak cytoplasmic immunostaining. Adenomas and CRACs demonstrated up-regulated p-PKCζ/λ detection. Cytoplasmic p-PKCζ/λ expression was higher in CRAC than in adenoma. In CRACs, p-PKCζ/λ expression was inversely correlated with pathologic TNM stage (I-II versus III-IV) and poor differentiation. Statistical correlations between low expression of p-PKCζ/λ with shortened overall survival and disease-free survival were seen (p=0.004 and p=0.034, respectively). Conclusions: P-PKCζ/λ overexpression is implicated in tumorigenesis but down-regulation was a poor prognostic factor in CRAC.
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Affiliation(s)
- Min-Kyung Yeo
- Department of Pathology, Cancer Research Institute, Chungnam National University School of Medicine, Daejeon, Republic of Korea
| | - Ji Yeon Kim
- Department of Surgery, Chungnam National University Hospital, Daejeon, Republic of Korea
| | - In-Ock Seong
- Department of Pathology, Cancer Research Institute, Chungnam National University School of Medicine, Daejeon, Republic of Korea
| | - Jin-Man Kim
- Department of Pathology and Medical Science, Chungnam National University School of Medicine, Daejeon, Republic of Korea
| | - Kyung-Hee Kim
- Department of Pathology, Cancer Research Institute, Chungnam National University School of Medicine, Daejeon, Republic of Korea
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11
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Brelje TC, Bhagroo NV, Stout LE, Sorenson RL. Prolactin and oleic acid synergistically stimulate β-cell proliferation and growth in rat islets. Islets 2017; 9:e1330234. [PMID: 28686504 PMCID: PMC5510617 DOI: 10.1080/19382014.2017.1330234] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Islet adaptation to pregnancy is largely influenced by prolactin and placental lactogens. In addition serum lipids are significantly increased. Here, we report the novel observation that prolactin and oleic acid synergistically stimulate islet cell proliferation and islet growth. In neonatal rat islets, prolactin increased proliferation 6-fold, oleic acid 3.5-fold, and their combination 15-fold. The expression of insulin in these dividing cells establishes them as β-cells. Similar changes were seen in islet growth. This synergy is restricted to monounsaturated fatty acids and does not occur with other islet growth factors. Oleic acid increases prolactin-induced STAT5 phosphorylation, even though by itself it is unable to induce STAT5 phosphorylation. Their effects on Erk1/2 phosphorylation are additive. Some of the synergy requires the formation of oleoyl CoA and/or its metabolites. Unexpectedly, methyl oleic acid, a non-metabolizable analog of oleic acid, also shows synergy with prolactin. In summary, prolactin and oleic acid synergistically stimulate islet cell proliferation and islet growth in rat islets, oleic acid increases prolactin-induced STAT5 activation, and requires both the metabolism of oleic acid and non-metabolized oleic acid. Since oleic acid is the most abundant monounsaturated fatty acid in serum that is elevated during pregnancy, it may contribute to increased β-cell proliferation seen during pregnancy.
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Affiliation(s)
- Todd Clark Brelje
- Department of Genetics, Cell Biology, and Development, University of Minnesota Medical School, Minneapolis, MN, USA
| | - Nicholas V. Bhagroo
- Department of Genetics, Cell Biology, and Development, University of Minnesota Medical School, Minneapolis, MN, USA
| | - Laurence E. Stout
- Department of Genetics, Cell Biology, and Development, University of Minnesota Medical School, Minneapolis, MN, USA
| | - Robert L. Sorenson
- Department of Genetics, Cell Biology, and Development, University of Minnesota Medical School, Minneapolis, MN, USA
- CONTACT Robert L. Sorenson Department of Genetics, Cell Biology, and Development, University of Minnesota Medical School, 6–160 Jackson Hall, 321 Church Street SE, Minneapolis, MN 55455, USA
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Datta T, Przyklenk K, Datta NS. Parathyroid Hormone-Related Peptide: A Novel Endocrine Cardioprotective "Conditioning Mimetic". J Cardiovasc Pharmacol Ther 2017; 22:529-537. [PMID: 28403647 DOI: 10.1177/1074248417702976] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
An as-yet limited body of evidence suggests that calcium-regulating endocrine hormones-in particular, parathyroid hormone-related peptide (PTHrP)-may have unappreciated cardioprotective effects. The current review focuses on the concept that PTHrP may, via modulation of classic cardioprotective signaling pathways, provide a novel strategy to attenuate myocardial ischemia-reperfusion injury.
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Affiliation(s)
- Tanuka Datta
- 1 Department of Internal Medicine, George Washington University, Washington, DC, USA
| | - Karin Przyklenk
- 2 Cardiovascular Research Institute, Wayne State University School of Medicine, Detroit, MI, USA.,3 Department of Physiology, Wayne State University School of Medicine, Detroit, MI, USA.,4 Department of Emergency Medicine, Wayne State University School of Medicine, Detroit, MI, USA
| | - Nabanita S Datta
- 2 Cardiovascular Research Institute, Wayne State University School of Medicine, Detroit, MI, USA.,5 Department of Internal Medicine, Wayne State University School of Medicine, Detroit, MI, USA
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Benthuysen JR, Carrano AC, Sander M. Advances in β cell replacement and regeneration strategies for treating diabetes. J Clin Invest 2016; 126:3651-3660. [PMID: 27694741 DOI: 10.1172/jci87439] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
In the past decade, new approaches have been explored that are aimed at restoring functional β cell mass as a treatment strategy for diabetes. The two most intensely pursued strategies are β cell replacement through conversion of other cell types and β cell regeneration by enhancement of β cell replication. The approach closest to clinical implementation is the replacement of β cells with human pluripotent stem cell-derived (hPSC-derived) cells, which are currently under investigation in a clinical trial to assess their safety in humans. In addition, there has been success in reprogramming developmentally related cell types into β cells. Reprogramming approaches could find therapeutic applications by inducing β cell conversion in vivo or by reprogramming cells ex vivo followed by implantation. Finally, recent studies have revealed novel pharmacologic targets for stimulating β cell replication. Manipulating these targets or the pathways they regulate could be a strategy for promoting the expansion of residual β cells in diabetic patients. Here, we provide an overview of progress made toward β cell replacement and regeneration and discuss promises and challenges for clinical implementation of these strategies.
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Mozar A, Lin H, Williams K, Chin C, Li R, Kondegowda NG, Stewart AF, Garcia-Ocaña A, Vasavada RC. Parathyroid Hormone-Related Peptide (1-36) Enhances Beta Cell Regeneration and Increases Beta Cell Mass in a Mouse Model of Partial Pancreatectomy. PLoS One 2016; 11:e0158414. [PMID: 27391423 PMCID: PMC4938460 DOI: 10.1371/journal.pone.0158414] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Accepted: 06/15/2016] [Indexed: 12/26/2022] Open
Abstract
AIMS/HYPOTHESIS Finding ways to stimulate the regeneration of endogenous pancreatic beta cells is an important goal in the treatment of diabetes. Parathyroid hormone-related protein (PTHrP), the full-length (1-139) and amino-terminal (1-36) peptides, enhance beta cell function, proliferation, and survival. Therefore, we hypothesize that PTHrP(1-36) has the potential to regenerate endogenous beta cells. METHODS The partial pancreatectomy (PPx) mouse model of beta cell injury was used to test this hypothesis. Male Balb/c mice underwent either sham-operation or PPx, and were subsequently injected with PTHrP(1-36) (160μg/kg) or vehicle (veh), for 7, 30, or 90 days. The four groups of mice, sham-veh, sham-PTHrP, PPx-veh, and PPx-PTHrP were assessed for PTHrP and receptor expression, and glucose and beta cell homeostasis. RESULTS PTHrP-receptor, but not the ligand, was significantly up-regulated in islets from mice that underwent PPx compared to sham-operated mice. This suggests that exogenous PTHrP could further enhance beta cell regeneration after PPx. PTHrP did not significantly affect body weight, blood glucose, plasma insulin, or insulin sensitivity, in either sham or PPx mice. Glucose tolerance improved in the PPx-PTHrP versus PPx-veh mice only in the early stages of treatment. As hypothesized, there was a significant increase in beta cell proliferation in PPx-PTHrP mice at days 7 and 30; however, this was normalized by day 90, compared to PPx-veh mice. Enhanced beta cell proliferation translated to a marked increase in beta cell mass at day 90, in PPx-PTHrP versus PPx-veh mice. CONCLUSIONS PTHrP(1-36) significantly enhances beta cell regeneration through increased beta cell proliferation and beta cell mass after PPx. Future studies will determine the potential of PTHrP to enhance functional beta cell mass in the setting of diabetes.
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Affiliation(s)
- Anaïs Mozar
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Hugo Lin
- Division of Endocrinology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Katoura Williams
- Division of Endocrinology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Connie Chin
- Division of Endocrinology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Rosemary Li
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Nagesha Guthalu Kondegowda
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Andrew F. Stewart
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Adolfo Garcia-Ocaña
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Rupangi Chhaya Vasavada
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
- * E-mail:
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15
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Guan B, Li W, Li F, Xie Y, Ni Q, Gu Y, Li X, Wang Q, Zhang H, Ning G. Sfrp5 mediates glucose-induced proliferation in rat pancreatic β-cells. J Endocrinol 2016; 229:73-83. [PMID: 26869333 DOI: 10.1530/joe-15-0535] [Citation(s) in RCA: 13] [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: 02/07/2016] [Accepted: 02/11/2016] [Indexed: 01/07/2023]
Abstract
The cellular and molecular mechanisms of glucose-stimulated β-cell proliferation are poorly understood. Recently, secreted frizzled-related protein 5 (encoded by Sfrp5; a Wnt signaling inhibitor) has been demonstrated to be involved in β-cell proliferation in obesity. A previous study demonstrated that glucose enhanced Wnt signaling to promote cell proliferation. We hypothesized that inhibition of SFRP5 contributes to glucose-stimulated β-cell proliferation. In this study, we found that the Sfrp5 level was significantly reduced in high glucose-treated INS-1 cells, primary rat β-cells, and islets isolated from glucose-infused rats. Overexpression of SFRP5 diminished glucose-stimulated proliferation in both INS-1 cells and primary β-cells, with a concomitant inhibition of the Wnt signaling pathway and decreased cyclin D2 expression. In addition, we showed that glucose-induced Sfrp5 suppression was modulated by the PI3K/AKT pathway. Therefore, we conclude that glucose inhibits Sfrp5 expression via the PI3K/AKT pathway and hence promotes rat pancreatic β-cell proliferation.
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Affiliation(s)
- Binbin Guan
- Shanghai Institute of Endocrine and Metabolic DiseasesShanghai Clinical Center for Endocrine and Metabolic Diseases, Department of Endocrinology and Metabolic Diseases, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, P R China Department of EndocrinologyFuJian Union hospital, Fuzhou, P R China
| | - Wenyi Li
- Shanghai Institute of Endocrine and Metabolic DiseasesShanghai Clinical Center for Endocrine and Metabolic Diseases, Department of Endocrinology and Metabolic Diseases, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, P R China
| | - Fengying Li
- Shanghai Institute of Endocrine and Metabolic DiseasesShanghai Clinical Center for Endocrine and Metabolic Diseases, Department of Endocrinology and Metabolic Diseases, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, P R China
| | - Yun Xie
- Shanghai Institute of Endocrine and Metabolic DiseasesShanghai Clinical Center for Endocrine and Metabolic Diseases, Department of Endocrinology and Metabolic Diseases, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, P R China
| | - Qicheng Ni
- Shanghai Institute of Endocrine and Metabolic DiseasesShanghai Clinical Center for Endocrine and Metabolic Diseases, Department of Endocrinology and Metabolic Diseases, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, P R China
| | - Yanyun Gu
- Shanghai Institute of Endocrine and Metabolic DiseasesShanghai Clinical Center for Endocrine and Metabolic Diseases, Department of Endocrinology and Metabolic Diseases, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, P R China
| | - Xiaoying Li
- Shanghai Institute of Endocrine and Metabolic DiseasesShanghai Clinical Center for Endocrine and Metabolic Diseases, Department of Endocrinology and Metabolic Diseases, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, P R China
| | - Qidi Wang
- Shanghai Institute of Endocrine and Metabolic DiseasesShanghai Clinical Center for Endocrine and Metabolic Diseases, Department of Endocrinology and Metabolic Diseases, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, P R China
| | - Hongli Zhang
- Shanghai Institute of Endocrine and Metabolic DiseasesShanghai Clinical Center for Endocrine and Metabolic Diseases, Department of Endocrinology and Metabolic Diseases, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, P R China
| | - Guang Ning
- Shanghai Institute of Endocrine and Metabolic DiseasesShanghai Clinical Center for Endocrine and Metabolic Diseases, Department of Endocrinology and Metabolic Diseases, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, P R China
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16
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Lakshmipathi J, Alvarez-Perez JC, Rosselot C, Casinelli GP, Stamateris RE, Rausell-Palamos F, O'Donnell CP, Vasavada RC, Scott DK, Alonso LC, Garcia-Ocaña A. PKCζ Is Essential for Pancreatic β-Cell Replication During Insulin Resistance by Regulating mTOR and Cyclin-D2. Diabetes 2016; 65:1283-96. [PMID: 26868297 PMCID: PMC4839210 DOI: 10.2337/db15-1398] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Accepted: 02/06/2016] [Indexed: 12/23/2022]
Abstract
Adaptive β-cell replication occurs in response to increased metabolic demand during insulin resistance. The intracellular mediators of this compensatory response are poorly defined and their identification could provide significant targets for β-cell regeneration therapies. Here we show that glucose and insulin in vitro and insulin resistance in vivo activate protein kinase C ζ (PKCζ) in pancreatic islets and β-cells. PKCζ is required for glucose- and glucokinase activator-induced proliferation of rodent and human β-cells in vitro. Furthermore, either kinase-dead PKCζ expression (KD-PKCζ) or disruption of PKCζ in mouse β-cells blocks compensatory β-cell replication when acute hyperglycemia/hyperinsulinemia is induced. Importantly, KD-PKCζ inhibits insulin resistance-mediated mammalian target of rapamycin (mTOR) activation and cyclin-D2 upregulation independent of Akt activation. In summary, PKCζ activation is key for early compensatory β-cell replication in insulin resistance by regulating the downstream signals mTOR and cyclin-D2. This suggests that alterations in PKCζ expression or activity might contribute to inadequate β-cell mass expansion and β-cell failure leading to type 2 diabetes.
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Affiliation(s)
- Jayalakshmi Lakshmipathi
- Diabetes, Obesity and Metabolism Institute, Division of Endocrinology, Diabetes and Bone Diseases, The Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Juan Carlos Alvarez-Perez
- Diabetes, Obesity and Metabolism Institute, Division of Endocrinology, Diabetes and Bone Diseases, The Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Carolina Rosselot
- Diabetes, Obesity and Metabolism Institute, Division of Endocrinology, Diabetes and Bone Diseases, The Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Gabriella P Casinelli
- Division of Pediatric Hematology/Oncology and Blood and Marrow Transplantation, Department of Pediatrics, Children's Hospital of Pittsburgh, Pittsburgh, PA
| | - Rachel E Stamateris
- Department of Medicine, University of Massachusetts Medical School, Worcester, MA
| | - Francisco Rausell-Palamos
- Diabetes, Obesity and Metabolism Institute, Division of Endocrinology, Diabetes and Bone Diseases, The Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Christopher P O'Donnell
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, PA
| | - Rupangi C Vasavada
- Diabetes, Obesity and Metabolism Institute, Division of Endocrinology, Diabetes and Bone Diseases, The Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Donald K Scott
- Diabetes, Obesity and Metabolism Institute, Division of Endocrinology, Diabetes and Bone Diseases, The Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Laura C Alonso
- Department of Medicine, University of Massachusetts Medical School, Worcester, MA
| | - Adolfo Garcia-Ocaña
- Diabetes, Obesity and Metabolism Institute, Division of Endocrinology, Diabetes and Bone Diseases, The Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, New York, NY
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17
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Saunders D, Powers AC. Replicative capacity of β-cells and type 1 diabetes. J Autoimmun 2016; 71:59-68. [PMID: 27133598 DOI: 10.1016/j.jaut.2016.03.014] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Accepted: 03/28/2016] [Indexed: 12/16/2022]
Abstract
Efforts to restore β-cell number or mass in type 1 diabetes (T1D) must combine an intervention to stimulate proliferation of remaining β-cells and an intervention to mitigate or control the β-cell-directed autoimmunity. This review highlights features of the β-cell, including it being part of a pancreatic islet, a mini-organ that is highly vascularized and highly innervated, and efforts to promote β-cell proliferation. In addition, the β-cell in T1D exists in a microenvironment with interactions and input from other islet cell types, extracellular matrix, vascular endothelial cells, neuronal projections, and immune cells, all of which likely influence the β-cell's capacity for replication. Physiologic β-cell proliferation occurs in human and rodents in the neonatal period and early in life, after which there is an age-dependent decline in β-cell proliferation, and also as part of the β-cell's compensatory response to the metabolic challenges of pregnancy and insulin resistance. This review reviews the molecular pathways involved in this β-cell proliferation and highlights recent work in two areas: 1) Investigators, using high-throughput screening to discover small molecules that promote human β-cell proliferation, are now focusing on the dual-specificity tyrosine-regulated kinase-1a and cell cycle-dependent kinase inhibitors CDKN2C/p18 or CDKN1A/p21as targets of compounds to stimulate adult human β-cell proliferation. 2) Local inflammation, macrophages, and the local β-cell microenvironment promote β-cell proliferation. Future efforts to harness the responsible mechanisms may lead to new approaches to promote β-cell proliferation in T1D.
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Affiliation(s)
- Diane Saunders
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Alvin C Powers
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN, United States; Division of Diabetes, Endocrinology, and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States; VA Tennessee Valley Healthcare System, Nashville, TN, United States.
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18
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Stamateris RE, Sharma RB, Kong Y, Ebrahimpour P, Panday D, Ranganath P, Zou B, Levitt H, Parambil NA, O'Donnell CP, García-Ocaña A, Alonso LC. Glucose Induces Mouse β-Cell Proliferation via IRS2, MTOR, and Cyclin D2 but Not the Insulin Receptor. Diabetes 2016; 65:981-95. [PMID: 26740601 PMCID: PMC5314707 DOI: 10.2337/db15-0529] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2015] [Accepted: 12/29/2015] [Indexed: 12/21/2022]
Abstract
An important goal in diabetes research is to understand the processes that trigger endogenous β-cell proliferation. Hyperglycemia induces β-cell replication, but the mechanism remains debated. A prime candidate is insulin, which acts locally through the insulin receptor. Having previously developed an in vivo mouse hyperglycemia model, we tested whether glucose induces β-cell proliferation through insulin signaling. By using mice lacking insulin signaling intermediate insulin receptor substrate 2 (IRS2), we confirmed that hyperglycemia-induced β-cell proliferation requires IRS2 both in vivo and ex vivo. Of note, insulin receptor activation was not required for glucose-induced proliferation, and insulin itself was not sufficient to drive replication. Glucose and insulin caused similar acute signaling in mouse islets, but chronic signaling differed markedly, with mammalian target of rapamycin (MTOR) and extracellular signal-related kinase (ERK) activation by glucose and AKT activation by insulin. MTOR but not ERK activation was required for glucose-induced proliferation. Cyclin D2 was necessary for glucose-induced β-cell proliferation. Cyclin D2 expression was reduced when either IRS2 or MTOR signaling was lost, and restoring cyclin D2 expression rescued the proliferation defect. Human islets shared many of these regulatory pathways. Taken together, these results support a model in which IRS2, MTOR, and cyclin D2, but not the insulin receptor, mediate glucose-induced proliferation.
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Affiliation(s)
- Rachel E Stamateris
- Diabetes Center of Excellence, Department of Medicine, University of Massachusetts Medical School, Worcester, MA
| | - Rohit B Sharma
- Diabetes Center of Excellence, Department of Medicine, University of Massachusetts Medical School, Worcester, MA
| | - Yahui Kong
- Diabetes Center of Excellence, Department of Medicine, University of Massachusetts Medical School, Worcester, MA
| | - Pantea Ebrahimpour
- Diabetes Center of Excellence, Department of Medicine, University of Massachusetts Medical School, Worcester, MA
| | - Deepika Panday
- Diabetes Center of Excellence, Department of Medicine, University of Massachusetts Medical School, Worcester, MA
| | - Pavana Ranganath
- Diabetes Center of Excellence, Department of Medicine, University of Massachusetts Medical School, Worcester, MA
| | - Baobo Zou
- Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA
| | - Helena Levitt
- Division of Endocrinology, University of Pittsburgh School of Medicine, Pittsburgh, PA
| | | | - Christopher P O'Donnell
- Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA
| | - Adolfo García-Ocaña
- Diabetes, Obesity and Metabolism Institute, Division of Endocrinology, Diabetes and Bone Disease, The Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Laura C Alonso
- Diabetes Center of Excellence, Department of Medicine, University of Massachusetts Medical School, Worcester, MA
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19
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Noor NM, Banim PJ, Luben RN, Khaw KT, Hart AR. Investigating Physical Activity in the Etiology of Pancreatic Cancer: The Age at Which This Is Measured Is Important and Is Independent of Body Mass Index. Pancreas 2016; 45:388-93. [PMID: 26390426 PMCID: PMC4743065 DOI: 10.1097/mpa.0000000000000494] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
OBJECTIVES There are plausible biological mechanisms for how increased physical activity (PA) may prevent pancreatic cancer, although findings from epidemiological studies are inconsistent. We investigated whether the risk is dependent on the age at which PA is measured and if independent of body mass index (BMI). METHODS A total of 23,639 participants, aged 40 to 74 years, were recruited into the EPIC-Norfolk (European Prospective Investigation of Cancer) cohort study between 1993 and 1997 and completed validated questionnaires on PA. The cohort was monitored for pancreatic cancer development, and hazard ratios (HRs) were estimated and adjusted for covariates. RESULTS Within 17 years, 88 participants developed pancreatic cancer (55% female). There was no association between PA and risk in the cohort (HR trend, 1.06; 95% confidence interval [CI], 0.86-1.29). However, in participants younger than 60 years, higher PA was associated with decreased risk (highest vs lowest category HR, 0.27; 95% CI, 0.07-0.99). Higher PA was not inversely associated when older than 60 years (HR trend, 1.23; 95% CI, 0.96-1.57). Including BMI in all models produced similar estimates. CONCLUSIONS The reasons why PA in younger, but not older, people may prevent pancreatic cancer need to be investigated. Physical activity may operate through mechanisms independent of BMI. If this association is causal, 1 in 6 cases might be prevented by encouraging more PA.
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Affiliation(s)
- Nurulamin M. Noor
- Department of Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Paul J.R. Banim
- Department of Gastroenterology, James Paget University Hospital, Great Yarmouth, United Kingdom
| | - Robert N. Luben
- Institute of Public Health, University of Cambridge, Cambridge, United Kingdom
| | - Kay-Tee Khaw
- Institute of Public Health, University of Cambridge, Cambridge, United Kingdom
| | - Andrew R. Hart
- Department of Medicine, Norwich Medical School, University of East Anglia, Norwich, United Kingdom
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20
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Bedinger DH, Adams SH. Metabolic, anabolic, and mitogenic insulin responses: A tissue-specific perspective for insulin receptor activators. Mol Cell Endocrinol 2015; 415:143-56. [PMID: 26277398 DOI: 10.1016/j.mce.2015.08.013] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 08/05/2015] [Accepted: 08/09/2015] [Indexed: 12/17/2022]
Abstract
Insulin acts as the major regulator of the fasting-to-fed metabolic transition by altering substrate metabolism, promoting energy storage, and helping activate protein synthesis. In addition to its glucoregulatory and other metabolic properties, insulin can also act as a growth factor. The metabolic and mitogenic responses to insulin are regulated by divergent post-receptor signaling mechanisms downstream from the activated insulin receptor (IR). However, the anabolic and growth-promoting properties of insulin require tissue-specific inter-relationships between the two pathways, and the nature and scope of insulin-regulated processes vary greatly across tissues. Understanding the nuances of this interplay between metabolic and growth-regulating properties of insulin would have important implications for development of novel insulin and IR modulator therapies that stimulate insulin receptor activation in both pathway- and tissue-specific manners. This review will provide a unique perspective focusing on the roles of "metabolic" and "mitogenic" actions of insulin signaling in various tissues, and how these networks should be considered when evaluating selective pharmacologic approaches to prevent or treat metabolic disease.
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Affiliation(s)
| | - Sean H Adams
- Arkansas Children's Nutrition Center and University of Arkansas for Medical Sciences, Department of Pediatrics, Little Rock, AR, USA
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21
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Tiwari S, Roel C, Wills R, Casinelli G, Tanwir M, Takane KK, Fiaschi-Taesch NM. Early and Late G1/S Cyclins and Cdks Act Complementarily to Enhance Authentic Human β-Cell Proliferation and Expansion. Diabetes 2015; 64:3485-98. [PMID: 26159177 PMCID: PMC4876788 DOI: 10.2337/db14-1885] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Accepted: 06/20/2015] [Indexed: 12/20/2022]
Abstract
β-Cell regeneration is a key goal of diabetes research. Progression through the cell cycle is associated with retinoblastoma protein (pRb) inactivation via sequential phosphorylation by the "early" cyclins and cyclin-dependent kinases (cdks) (d-cyclins cdk4/6) and the "late" cyclins and cdks (cyclin A/E and cdk1/2). In β-cells, activation of either early or late G1/S cyclins and/or cdks is an efficient approach to induce cycle entry, but it is unknown whether the combined expression of early and late cyclins and cdks might have synergistic or additive effects. Thus, we explored whether a combination of both early and late cyclins and cdks might more effectively drive human β-cell cell cycle entry than either group alone. We also sought to determine whether authentic replication with the expansion of adult human β-cells could be demonstrated. Late cyclins and cdks do not traffic in response to the induction of replication by early cyclins and cdks in human β-cells but are capable of nuclear translocation when overexpressed. Early plus late cyclins and cdks, acting via pRb phosphorylation on distinct residues, complementarily induce greater proliferation in human β-cells than either group alone. Importantly, the combination of early and late cyclins and cdks clearly increased human β-cell numbers in vitro. These findings provide additional insight into human β-cell expansion. They also provide a novel tool for assessing β-cell expansion in vitro.
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Affiliation(s)
- Shiwani Tiwari
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Chris Roel
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Rachel Wills
- Division of Endocrinology and Metabolism, University of Pittsburgh School of Medicine, Pittsburgh, PA
| | - Gabriella Casinelli
- Division of Endocrinology and Metabolism, University of Pittsburgh School of Medicine, Pittsburgh, PA
| | - Mansoor Tanwir
- Division of Endocrinology and Metabolism, University of Pittsburgh School of Medicine, Pittsburgh, PA
| | - Karen K Takane
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Nathalie M Fiaschi-Taesch
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, New York, NY Division of Endocrinology and Metabolism, University of Pittsburgh School of Medicine, Pittsburgh, PA
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22
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Seed Ahmed M, Ahmed MS, Pelletier J, Leumann H, Gu HF, Östenson CG. Expression of Protein Kinase C Isoforms in Pancreatic Islets and Liver of Male Goto-Kakizaki Rats, a Model of Type 2 Diabetes. PLoS One 2015; 10:e0135781. [PMID: 26398746 PMCID: PMC4580567 DOI: 10.1371/journal.pone.0135781] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Accepted: 07/27/2015] [Indexed: 02/03/2023] Open
Abstract
Protein kinase C (PKC) is a family of protein kinases controlling protein phosphorylation and playing important roles in the regulation of metabolism. We have investigated expression levels of PKC isoforms in pancreatic islets and liver of diabetic Goto-Kakizaki (GK) rats with and without insulin treatment to evaluate their association with glucose homeostasis. mRNA and protein expression levels of PKC isoforms were assessed in pancreatic islets and liver of Wistar rats and GK rats with or without insulin treatment. PKCα and PKCζ mRNA expressions were down-regulated in islets of GK compared with Wistar rats. PKCα and phosphorylated PKCα (p-PKCα) protein expressions were decreased in islets of GK compared with insulin-treated GK and Wistar rats. PKCζ protein expression in islets was reduced in GK and insulin-treated GK compared with Wistar rats, but p-PKCζ was decreased only in GK rats. Islet PKCε mRNA and protein expressions were lower in GK compared with insulin-treated GK and Wistar rats. In liver, PKCδ and PKCζ mRNA expressions were decreased in both GK and insulin-treated GK compared with Wistar rats. Hepatic PKCζ protein expression was diminished in both GK rats with and without insulin treatment compared with Wistar rats. Hepatic PKCε mRNA expression was down-regulated in insulin-treated GK compared with GK and Wistar rats. PKCα, PKCε, and p-PKCζ expressions were secondary to hyperglycaemia in GK rat islets. Hepatic PKCδ and PKCζ mRNA expressions were primarily linked to hyperglycaemia. Additionally, hepatic PKCε mRNA expression could be under control of insulin.
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Affiliation(s)
- Mohammed Seed Ahmed
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Karolinska University Hospital, Solna, Stockholm, Sweden; Department of Physiology, Faculty of Medicine, University of Khartoum, Khartoum, Sudan
| | | | - Julien Pelletier
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Karolinska University Hospital, Solna, Stockholm, Sweden
| | - Hannes Leumann
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Karolinska University Hospital, Solna, Stockholm, Sweden
| | - Harvest F Gu
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Karolinska University Hospital, Solna, Stockholm, Sweden
| | - Claes-Göran Östenson
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Karolinska University Hospital, Solna, Stockholm, Sweden
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TRPV6 channel modulates proliferation of insulin secreting INS-1E beta cell line. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1853:3202-10. [PMID: 26384871 DOI: 10.1016/j.bbamcr.2015.09.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Revised: 09/10/2015] [Accepted: 09/11/2015] [Indexed: 12/21/2022]
Abstract
Transient receptor potential channel vanilloid type 6 (TRPV6) is a non-selective cation channel with high permeability for Ca²⁺ ions. So far, the role of TRPV6 in pancreatic beta cells is unknown. In the present study, we characterized the role of TRPV6 in controlling calcium signaling, cell proliferation as well as insulin expression, and secretion in experimental INS-1E beta cell model. TRPV6 protein production was downregulated using siRNA by approx. 70%, as detected by Western blot. Intracellular free Ca²⁺ ([Ca²⁺]i) was measured by fluorescence Ca²⁺ imaging using fura-2. Calcineurin/NFAT signaling was analyzed using a NFAT reporter assay as well as a calcineurin activity assay. TRPV6 downregulation resulted in impaired cellular calcium influx. Its downregulation also reduced cell proliferation and decreased insulin mRNA expression. These changes were companied by the inhibition of the calcineurin/NFAT signaling. In contrast, insulin exocytosis was not affected by TRPV6 downregulation. In conclusion, this study demonstrates for the first time the expression of TRPV6 in INS-1E cells and rat pancreatic beta cells and describes its role in modulating calcium signaling, beta cell proliferation and insulin mRNA expression. In contrast, TRPV6 fails to influence insulin secretion.
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24
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Alvarez-Perez JC, Rosa TC, Casinelli GP, Valle SR, Lakshmipathi J, Rosselot C, Rausell-Palamos F, Vasavada RC, García-Ocaña A. Hepatocyte growth factor ameliorates hyperglycemia and corrects β-cell mass in IRS2-deficient mice. Mol Endocrinol 2015; 28:2038-48. [PMID: 25361392 DOI: 10.1210/me.2014-1207] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Insulin resistance, when combined with decreased β-cell mass and relative insufficient insulin secretion, leads to type 2 diabetes. Mice lacking the IRS2 gene (IRS2(-/-) mice) develop diabetes due to uncompensated insulin resistance and β-cell failure. Hepatocyte growth factor (HGF) activates the phosphatidylinositol 3-kinase/Akt signaling pathway in β-cells without recruitment of IRS1 or IRS2 and increases β-cell proliferation, survival, mass, and function when overexpressed in β-cells of transgenic (TG) mice. We therefore hypothesized that HGF may protect against β-cell failure in IRS2 deficiency. For that purpose, we cross-bred TG mice overexpressing HGF in β-cells with IRS2 knockout (KO) mice. Glucose homeostasis analysis revealed significantly reduced hyperglycemia, compensatory hyperinsulinemia, and improved glucose tolerance in TG/KO mice compared with those in KO mice in the context of similar insulin resistance. HGF overexpression also increased glucose-stimulated insulin secretion in IRS2(-/-) islets. To determine whether this glucose homeostasis improvement correlated with alterations in β-cells, we measured β-cell mass, proliferation, and death in these mice. β-Cell proliferation was increased and death was decreased in TG/KO mice compared with those in KO mice. As a result, β-cell mass was significantly increased in TG/KO mice compared with that in KO mice, reaching levels similar to those in wild-type mice. Analysis of the intracellular targets involved in β-cell failure in IRS2 deficiency showed Pdx-1 up-regulation, Akt/FoxO1 phosphorylation, and p27 down-regulation in TG/KO mouse islets. Taken together, these results indicate that HGF can compensate for IRS2 deficiency and subsequent insulin resistance by normalizing β-cell mass and increasing circulating insulin. HGF may be of value as a therapeutic agent against β-cell failure.
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Affiliation(s)
- Juan C Alvarez-Perez
- Diabetes, Obesity and Metabolism Institute (J.C.A.-P., J.L., C.R., F.R.-P., R.C.V., A.G.-O.), Division of Endocrinology, Diabetes and Bone Diseases, The Mindich Child Health and Development Institute, Icahn School of Medicine at Mt Sinai, New York, New York 10029; and Department of Medicine (T.C.R., G.P.C., S.R.V.), Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania 15261
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DeFronzo RA, Ferrannini E, Groop L, Henry RR, Herman WH, Holst JJ, Hu FB, Kahn CR, Raz I, Shulman GI, Simonson DC, Testa MA, Weiss R. Type 2 diabetes mellitus. Nat Rev Dis Primers 2015; 1:15019. [PMID: 27189025 DOI: 10.1038/nrdp.2015.19] [Citation(s) in RCA: 982] [Impact Index Per Article: 109.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Type 2 diabetes mellitus (T2DM) is an expanding global health problem, closely linked to the epidemic of obesity. Individuals with T2DM are at high risk for both microvascular complications (including retinopathy, nephropathy and neuropathy) and macrovascular complications (such as cardiovascular comorbidities), owing to hyperglycaemia and individual components of the insulin resistance (metabolic) syndrome. Environmental factors (for example, obesity, an unhealthy diet and physical inactivity) and genetic factors contribute to the multiple pathophysiological disturbances that are responsible for impaired glucose homeostasis in T2DM. Insulin resistance and impaired insulin secretion remain the core defects in T2DM, but at least six other pathophysiological abnormalities contribute to the dysregulation of glucose metabolism. The multiple pathogenetic disturbances present in T2DM dictate that multiple antidiabetic agents, used in combination, will be required to maintain normoglycaemia. The treatment must not only be effective and safe but also improve the quality of life. Several novel medications are in development, but the greatest need is for agents that enhance insulin sensitivity, halt the progressive pancreatic β-cell failure that is characteristic of T2DM and prevent or reverse the microvascular complications. For an illustrated summary of this Primer, visit: http://go.nature.com/V2eGfN.
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Affiliation(s)
- Ralph A DeFronzo
- Diabetes Division, Department of Medicine, University of Texas Health Science Center, South Texas Veterans Health Care System and Texas Diabetes Institute, 701 S. Zarzamoro, San Antonio, Texas 78207, USA
| | | | - Leif Groop
- Department of Clinical Science Malmoe, Diabetes &Endocrinology, Lund University Diabetes Centre, Lund, Sweden
| | - Robert R Henry
- University of California, San Diego, Section of Diabetes, Endocrinology &Metabolism, Center for Metabolic Research, VA San Diego Healthcare System, San Diego, California, USA
| | | | | | - Frank B Hu
- Department of Nutrition, Harvard T.H. Chan School of Public Health and Department of Epidemiology, Harvard T.H. Chan School of Public Health and Channing Division of Network Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - C Ronald Kahn
- Harvard Medical School and Joslin Diabetes Center, Boston, Massachusetts, USA
| | - Itamar Raz
- Diabetes Unit, Division of Internal Medicine, Hadassah Hebrew University Hospital, Jerusalem, Israel
| | - Gerald I Shulman
- Howard Hughes Medical Institute and the Departments of Internal Medicine and Cellular &Molecular Physiology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Donald C Simonson
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Marcia A Testa
- Department of Biostatistics, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
| | - Ram Weiss
- Department of Human Metabolism and Nutrition, Braun School of Public Health, Hebrew University, Jerusalem, Israel
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Kondegowda NG, Fenutria R, Pollack IR, Orthofer M, Garcia-Ocaña A, Penninger JM, Vasavada RC. Osteoprotegerin and Denosumab Stimulate Human Beta Cell Proliferation through Inhibition of the Receptor Activator of NF-κB Ligand Pathway. Cell Metab 2015; 22:77-85. [PMID: 26094891 PMCID: PMC4597781 DOI: 10.1016/j.cmet.2015.05.021] [Citation(s) in RCA: 105] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Revised: 03/18/2015] [Accepted: 05/22/2015] [Indexed: 01/06/2023]
Abstract
Diabetes results from a reduction of pancreatic β-cells. Stimulating replication could normalize β-cell mass. However, adult human β-cells are recalcitrant to proliferation. We identified osteoprotegerin, a bone-related decoy receptor, as a β-cell mitogen. Osteoprotegerin was induced by and required for lactogen-mediated rodent β-cell replication. Osteoprotegerin enhanced β-cell proliferation in young, aged, and diabetic mice. This resulted in increased β-cell mass in young mice and significantly delayed hyperglycemia in diabetic mice. Osteoprotegerin stimulated replication of adult human β-cells, without causing dedifferentiation. Mechanistically, osteoprotegerin induced human and rodent β-cell replication by modulating CREB and GSK3 pathways, through binding Receptor Activator of NF-κB (RANK) Ligand (RANKL), a brake in β-cell proliferation. Denosumab, an FDA-approved osteoporosis drug, and RANKL-specific antibody induced human β-cell proliferation in vitro, and in vivo, in humanized mice. Thus, osteoprotegerin and Denosumab prevent RANKL/RANK interaction to stimulate β-cell replication, highlighting the potential for repurposing an osteoporosis drug to treat diabetes.
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Affiliation(s)
- Nagesha Guthalu Kondegowda
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Division of Endocrinology and Bone Disease, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Rafael Fenutria
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Division of Endocrinology and Bone Disease, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Ilana R Pollack
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Division of Endocrinology and Bone Disease, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Michael Orthofer
- IMBA, Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Dr. Bohrgasse 3,1030 Vienna, Austria
| | - Adolfo Garcia-Ocaña
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Division of Endocrinology and Bone Disease, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Josef M Penninger
- IMBA, Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Dr. Bohrgasse 3,1030 Vienna, Austria
| | - Rupangi C Vasavada
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Division of Endocrinology and Bone Disease, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.
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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.
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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
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Wang P, Fiaschi-Taesch NM, Vasavada RC, Scott DK, García-Ocaña A, Stewart AF. Diabetes mellitus--advances and challenges in human β-cell proliferation. Nat Rev Endocrinol 2015; 11:201-12. [PMID: 25687999 DOI: 10.1038/nrendo.2015.9] [Citation(s) in RCA: 157] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The treatment of diabetes mellitus represents one of the greatest medical challenges of our era. Diabetes results from a deficiency or functional impairment of insulin-producing β cells, alone or in combination with insulin resistance. It logically follows that the replacement or regeneration of β cells should reverse the progression of diabetes and, indeed, this seems to be the case in humans and rodents. This concept has prompted attempts in many laboratories to create new human β cells using stem-cell strategies to transdifferentiate or reprogramme non-β cells into β cells or to discover small molecules or other compounds that can induce proliferation of human β cells. This latter approach has shown promise, but has also proven particularly challenging to implement. In this Review, we discuss the physiology of normal human β-cell replication, the molecular mechanisms that regulate the cell cycle in human β cells, the upstream intracellular signalling pathways that connect them to cell surface receptors on β cells, the epigenetic mechanisms that control human β-cell proliferation and unbiased approaches for discovering novel molecules that can drive human β-cell proliferation. Finally, we discuss the potential and challenges of implementing strategies that replace or regenerate β cells.
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Affiliation(s)
- Peng Wang
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, Atran 5, Box 1152, 1 Gustave L. Levy Place, New York, NY 10029, USA
| | - Nathalie M Fiaschi-Taesch
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, Atran 5, Box 1152, 1 Gustave L. Levy Place, New York, NY 10029, USA
| | - Rupangi C Vasavada
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, Atran 5, Box 1152, 1 Gustave L. Levy Place, New York, NY 10029, USA
| | - Donald K Scott
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, Atran 5, Box 1152, 1 Gustave L. Levy Place, New York, NY 10029, USA
| | - Adolfo García-Ocaña
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, Atran 5, Box 1152, 1 Gustave L. Levy Place, New York, NY 10029, USA
| | - Andrew F Stewart
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, Atran 5, Box 1152, 1 Gustave L. Levy Place, New York, NY 10029, USA
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Xu X, Wang G, Zhou T, Chen L, Chen J, Shen X. Novel approaches to drug discovery for the treatment of type 2 diabetes. Expert Opin Drug Discov 2014; 9:1047-58. [PMID: 25054271 DOI: 10.1517/17460441.2014.941352] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
INTRODUCTION Type 2 diabetes mellitus (T2DM) is a chronic, complex and multifactorial metabolic disorder, which has become a serious global health problem. The side effects of known drugs and the deficiency of long-term safety data, in addition to the already determined adverse effects for the current preclinical drugs against T2DM, have largely called upon the urgent exploration of novel therapeutic and preventative strategies against this disease. AREAS COVERED The authors highlight the potential approaches for anti-T2DM drug discovery by focusing on: the restoration of pancreatic β-cell mass, the promotion of insulin secretion, the regulation of oxidative stress and endoplasmic reticulum (ER) stress and the modulation of autophagy. EXPERT OPINION T2DM is based on the gradual development of insulin resistance and β-cell dysfunction. Thus, the restoration of β-cell function is considered as one of the promising therapeutic strategies against T2DM. The stress factors, such as oxidative stress, ER stress and autophagy, play potent roles in the regulation of β-cell apoptosis, insulin secretion and sensitivity in the development of T2DM involving complicated cross-talks. Based on multiplex stress-involved regulatory networks, more and more novel potential targets have been discovered and the multi-targeted drug leads are expected to help develop more effective clinical agents for the treatment of T2DM.
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Affiliation(s)
- Xing Xu
- Shanghai Institute of Materia Medica, Key Laboratory of Receptor Research, Chinese Academy of Sciences , 555 Zuchongzhi Road, Shanghai 201203 , China ; ;
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Mozar A, Kondegowda NG, Pollack I, Fenutria R, Vasavada RC. The Role of PTHrP in Pancreatic Beta-Cells and Implications for Diabetes Pathophysiology and Treatment. Clin Rev Bone Miner Metab 2014. [DOI: 10.1007/s12018-014-9168-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Boras-Granic K, Dann P, VanHouten J, Karaplis A, Wysolmerski J. Deletion of the nuclear localization sequences and C-terminus of PTHrP impairs embryonic mammary development but also inhibits PTHrP production. PLoS One 2014; 9:e90418. [PMID: 24785493 PMCID: PMC4006745 DOI: 10.1371/journal.pone.0090418] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Accepted: 01/29/2014] [Indexed: 12/18/2022] Open
Abstract
Parathyroid hormone-related protein (PTHrP) can be secreted from cells and interact with its receptor, the Type 1 PTH/PTHrP Receptor (PTHR1) in an autocrine, paracrine or endocrine fashion. PTHrP can also remain inside cells and be transported into the nucleus, where its functions are unclear, although recent experiments suggest that it may broadly regulate cell survival and senescence. Disruption of either the PTHrP or PTHR1 gene results in many abnormalities including a failure of embryonic mammary gland development in mice and in humans. In order to examine the potential functions of nuclear PTHrP in the breast, we examined mammary gland development in PTHrP (1-84) knock-in mice, which express a mutant form of PTHrP that lacks the C-terminus and nuclear localization signals and which can be secreted but cannot enter the nucleus. Interestingly, we found that PTHrP (1-84) knock-in mice had defects in mammary mesenchyme differentiation and mammary duct outgrowth that were nearly identical to those previously described in PTHrP-/- and PTHR1-/- mice. However, the mammary buds in PTHrP (1-84) knock-in mice had severe reductions in mutant PTHrP mRNA levels, suggesting that the developmental defects were due to insufficient production of PTHrP by mammary epithelial cells and not loss of PTHrP nuclear function. Examination of the effects of nuclear PTHrP in the mammary gland in vivo will require the development of alternative animal models.
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Affiliation(s)
- Kata Boras-Granic
- Section of Endocrinology and Metabolism, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Pamela Dann
- Section of Endocrinology and Metabolism, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Joshua VanHouten
- Section of Endocrinology and Metabolism, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Andrew Karaplis
- Lady Davis Institute for Medical Research, Jewish General Hospital, McGill University, Montreal, Canada
| | - John Wysolmerski
- Section of Endocrinology and Metabolism, Yale University School of Medicine, New Haven, Connecticut, United States of America
- * E-mail:
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Affiliation(s)
- Aaron Bender
- Diabetes, Obesity and Metabolism Institute, The Icahn School of Medicine at Mount Sinai, Atran 5, 1 Gustave L. Levy Place, Box 1152, New York, NY, 10029, USA
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Abstract
The islets of Langerhans is the endocrine function region of pancreas, which exist in five cell types. The majority of endocrine cells are insulin-secreting β cells, mixed up with glucagon-secreting α-cells. The islets of Langerhans are highly vascularized, and the capillary network around the islet is about five times denser than that in the exocrine tissues. It guarantees endocrine cells adequately contact with the capillary networks. Above mentioned is the basis of deep study the interaction between β cells and capillary. Increasing number of studies contribute to the consensus that endothelial cells have positive effects in the islet microenvironment. Endothelial cells can act as endocrine cells which release many active substances, such as hepatocyte growth factors (HGF), thrombospondin-1(TSP-1), laminins, and collagens by means of different molecule pathways, inducing β cells differentiation, proliferation, survivor, and insulin release next to the vessels. Apart from the effect of endothelial cells on β cells by paracrine fashion, the islets can utilize VEGF-A, angiopoietin-1 and insulin signaling to increase the interaction with endothelial cells. As the endocrine role of endothelial cells to β cells, it may be a novel target to stimulate β cells regeneration, promote vascularization post islet transplantation strategy in the treatment of diabetes mellitus.
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Affiliation(s)
- Zilong Cao
- School of Medicine, Shandong University, Shandong 250012, P.R.China
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Ludwig B, Barthel A, Reichel A, Block NL, Ludwig S, Schally AV, Bornstein SR. Modulation of the pancreatic islet-stress axis as a novel potential therapeutic target in diabetes mellitus. VITAMINS AND HORMONES 2014; 95:195-222. [PMID: 24559919 DOI: 10.1016/b978-0-12-800174-5.00008-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Loss of pancreatic islet function and insulin-producing beta cell mass is a central hallmark in the pathogenesis of both type 1 and type 2 diabetes. While in type 1 diabetes this phenomenon is due to an extensive destruction of beta cells caused by an autoimmune process, the mechanisms resulting in beta cell failure in type 2 diabetes are different and less clear. Also, beta cell destruction in type 1 diabetes occurs early and is the initial step in the pathogenetic process, while beta cell loss in type 2 diabetes after an initial phase of hyperinsulinemia due to the underlying insulin resistance occurs relatively late and it is less pronounced. Since diabetes mellitus is the most frequent endocrine disease, with an increasing high prevalence worldwide, huge efforts have been made over the past many decades to identify predisposing genetic, environmental, and nutritional factors in order to develop effective strategies to prevent the disease. In parallel, extensive studies in different cell systems and animal models have helped to elucidate our understanding of the physiologic function of islets and to gain insight into the immunological and non-immunological mechanisms of beta cell destruction and failure. Furthermore, currently emerging concepts of beta cell regeneration (e.g., the restoration of the beta cell pool by regenerative, proliferative and antiapoptotic processes, and recovery of physiologic islet function) apparently is yielding the first promising results. Recent insights into the complex endocrine and paracrine mechanisms regulating the physiologic function of pancreatic islets, as well as beta cell life and death, constitute an essential part of this new and exciting area of diabetology. For example, understanding of the physiological role of glucagon-like peptide 1 has resulted in the successful clinical implementation of incretin-based therapies over the last years. Further, recent data suggesting paracrine effects of growth hormone-releasing hormone and corticotropin-releasing hormone on the regulation of pancreatic islet function, survival, and proliferation as well as on local glucocorticoid metabolism provide evidence for a potential role of the pancreatic islet-stress axis in the pathophysiology of diabetes mellitus. In this chapter, we provide a comprehensive overview of current preventive and regenerative concepts as a basis for the development of novel therapeutic approaches to the treatment of diabetes mellitus. A particular focus is given on the potential of the pancreatic islet-stress axis in the development of novel regenerative strategies.
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Affiliation(s)
- Barbara Ludwig
- Department of Medicine III, University Hospital Carl Gustav Carus, Dresden, Germany; The Paul Langerhans Institute, Dresden, Germany; Center for Regenerative Therapies Dresden, Dresden University of Technology, Dresden, Germany.
| | - Andreas Barthel
- Department of Medicine III, University Hospital Carl Gustav Carus, Dresden, Germany; Endokrinologikum Ruhr, Bochum, Germany
| | - Andreas Reichel
- Department of Medicine III, University Hospital Carl Gustav Carus, Dresden, Germany
| | - Norman L Block
- Department of Pathology, University of Miami Miller School of Medicine, Miami, Florida, USA; Department of Medicine, Division of Hematology-Oncology, University of Miami Miller School of Medicine, Miami, Florida, USA; Veterans Administration Medical Center, Miami, Florida, USA
| | - Stefan Ludwig
- Department of Visceral, Thorax and Vascular Surgery, University Hospital Carl Gustav Carus, Dresden, Germany
| | - Andrew V Schally
- Department of Pathology, University of Miami Miller School of Medicine, Miami, Florida, USA; Department of Medicine, Division of Endocrinology, University of Miami Miller School of Medicine, Miami, Florida, USA; Department of Medicine, Division of Hematology-Oncology, University of Miami Miller School of Medicine, Miami, Florida, USA; Veterans Administration Medical Center, Miami, Florida, USA
| | - Stefan R Bornstein
- Department of Medicine III, University Hospital Carl Gustav Carus, Dresden, Germany; The Paul Langerhans Institute, Dresden, Germany; Center for Regenerative Therapies Dresden, Dresden University of Technology, Dresden, Germany
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Alvarez-Perez JC, Ernst S, Demirci C, Casinelli GP, Mellado-Gil JMD, Rausell-Palamos F, Vasavada RC, Garcia-Ocaña A. Hepatocyte growth factor/c-Met signaling is required for β-cell regeneration. Diabetes 2014; 63:216-23. [PMID: 24089510 PMCID: PMC3868042 DOI: 10.2337/db13-0333] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Hepatocyte growth factor (HGF) is a mitogen required for β-cell replication during pregnancy. To determine whether HGF/c-Met signaling is required for β-cell regeneration, we characterized mice with pancreatic deletion of the HGF receptor, c-Met (PancMet KO mice), in two models of reduced β-cell mass and regeneration: multiple low-dose streptozotocin (MLDS) and partial pancreatectomy (Ppx). We also analyzed whether HGF administration could accelerate β-cell regeneration in wild-type (WT) mice after Ppx. Mouse islets obtained 7 days post-Ppx displayed significantly increased c-Met, suggesting a potential role for HGF/c-Met in β-cell proliferation in situations of reduced β-cell mass. Indeed, adult PancMet KO mice displayed markedly reduced β-cell replication compared with WT mice 7 days post-Ppx. Similarly, β-cell proliferation was decreased in PancMet KO mice in the MLDS mouse model. The decrease in β-cell proliferation post-Ppx correlated with a striking decrease in D-cyclin levels. Importantly, PancMet KO mice showed significantly diminished β-cell mass, decreased glucose tolerance, and impaired insulin secretion compared with WT mice 28 days post-Ppx. Conversely, HGF administration in WT Ppx mice further accelerated β-cell regeneration. These results indicate that HGF/c-Met signaling is critical for β-cell proliferation in situations of diminished β-cell mass and suggest that activation of this pathway can enhance β-cell regeneration.
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Affiliation(s)
- Juan Carlos Alvarez-Perez
- Diabetes, Obesity and Metabolism Institute, Division of Endocrinology, Diabetes and Bone Diseases, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Sara Ernst
- Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh, Pittsburgh, PA
| | - Cem Demirci
- Department of Pediatrics, University of Pittsburgh, Pittsburgh, PA
| | - Gabriella P. Casinelli
- Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh, Pittsburgh, PA
| | - Jose Manuel D. Mellado-Gil
- Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh, Pittsburgh, PA
| | - Francisco Rausell-Palamos
- Diabetes, Obesity and Metabolism Institute, Division of Endocrinology, Diabetes and Bone Diseases, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Rupangi C. Vasavada
- Diabetes, Obesity and Metabolism Institute, Division of Endocrinology, Diabetes and Bone Diseases, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Adolfo Garcia-Ocaña
- Diabetes, Obesity and Metabolism Institute, Division of Endocrinology, Diabetes and Bone Diseases, Icahn School of Medicine at Mount Sinai, New York, NY
- Corresponding author: Adolfo Garcia-Ocaña,
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Leslie KL, Song GJ, Barrick S, Wehbi VL, Vilardaga JP, Bauer PM, Bisello A. Ezrin-radixin-moesin-binding phosphoprotein 50 (EBP50) and nuclear factor-κB (NF-κB): a feed-forward loop for systemic and vascular inflammation. J Biol Chem 2013; 288:36426-36. [PMID: 24196963 DOI: 10.1074/jbc.m113.483339] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The interaction between vascular cells and macrophages is critical during vascular remodeling. Here we report that the scaffolding protein, ezrin-binding phosphoprotein 50 (EBP50), is a central regulator of macrophage and vascular smooth muscle cells (VSMC) function. EBP50 is up-regulated in intimal VSMC following endoluminal injury and promotes neointima formation. However, the mechanisms underlying these effects are not fully understood. Because of the fundamental role that inflammation plays in vascular diseases, we hypothesized that EBP50 mediates macrophage activation and the response of vessels to inflammation. Indeed, EBP50 expression increased in primary macrophages and VSMC, and in the aorta of mice, upon treatment with LPS or TNFα. This increase was nuclear factor-κB (NF-κB)-dependent. Conversely, activation of NF-κB was impaired in EBP50-null VSMC and macrophages. We found that inflammatory stimuli promote the formation of an EBP50-PKCζ complex at the cell membrane that induces NF-κB signaling. Macrophage activation and vascular inflammation after acute LPS treatment were reduced in EBP50-null cells and mice as compared with WT. Furthermore, macrophage recruitment to vascular lesions was significantly reduced in EBP50 knock-out mice. Thus, EBP50 and NF-κB participate in a feed-forward loop leading to increased macrophage activation and enhanced response of vascular cells to inflammation.
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López-Acosta JF, Moreno-Amador JL, Jiménez-Palomares M, Díaz-Marrero AR, Cueto M, Perdomo G, Cózar-Castellano I. Epoxypukalide induces proliferation and protects against cytokine-mediated apoptosis in primary cultures of pancreatic β-cells. PLoS One 2013; 8:e52862. [PMID: 23300997 PMCID: PMC3534672 DOI: 10.1371/journal.pone.0052862] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2012] [Accepted: 11/23/2012] [Indexed: 01/09/2023] Open
Abstract
There is an urgency to find new treatments for the devastating epidemic of diabetes. Pancreatic β-cells viability and function are impaired in the two most common forms of diabetes, type 1 and type 2. Regeneration of pancreatic β-cells has been proposed as a potential therapy for diabetes. In a preliminary study, we screened a collection of marine products for β-cell proliferation. One unique compound (epoxypukalide) showed capability to induce β-cell replication in the cell line INS1 832/13 and in primary rat cell cultures. Epoxypukalide was used to study β-cell proliferation by [3H]thymidine incorporation and BrdU incorporation followed by BrdU/insulin staining in primary cultures of rat islets. AKT and ERK1/2 signalling pathways were analyzed. Cell cycle activators, cyclin D2 and cyclin E, were detected by western-blot. Apoptosis was studied by TUNEL and cleaved caspase 3. β-cell function was measured by glucose-stimulated insulin secretion. Epoxypukalide induced 2.5-fold increase in β-cell proliferation; this effect was mediated by activation of ERK1/2 signalling pathway and upregulation of the cell cycle activators, cyclin D2 and cyclin E. Interestingly, epoxypukalide showed protection from basal (40% lower versus control) and cytokine-induced apoptosis (80% lower versus control). Finally, epoxypukalide did not impair β-cell function when measured by glucose-stimulated insulin secretion. In conclusion, epoxypukalide induces β-cell proliferation and protects against basal and cytokine-mediated β-cell death in primary cultures of rat islets. These findings may be translated into new treatments for diabetes.
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Affiliation(s)
- José Francisco López-Acosta
- Instituto de Genética y Biología Molecular (IBGM)-Universidad de Valladolid, Valladolid, Spain
- Unidad de Investigación, Hospital Universitario Puerta del Mar, Cádiz, Spain
| | | | | | - Ana R. Díaz-Marrero
- Instituto de Productos Naturales y Agrobiología del CSIC, La Laguna, Tenerife, Spain
| | - Mercedes Cueto
- Instituto de Productos Naturales y Agrobiología del CSIC, La Laguna, Tenerife, Spain
| | - Germán Perdomo
- Unidad de Investigación, Hospital Universitario Puerta del Mar, Cádiz, Spain
| | - Irene Cózar-Castellano
- Instituto de Genética y Biología Molecular (IBGM)-Universidad de Valladolid, Valladolid, Spain
- Unidad de Investigación, Hospital Universitario Puerta del Mar, Cádiz, Spain
- * E-mail:
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Abstract
PTHrP was identified as a cause of hypercalcemia in cancer patients 25 yr ago. In the intervening years, we have learned that PTHrP and PTH are encoded by related genes that are part of a larger "PTH gene family." This evolutionary relationship permits them to bind to the same type 1 PTH/PTHrP receptor, which explains why humoral hypercalcemia of malignancy resembles hyperparathyroidism. This review will outline basic facts about PTHrP biology and its normal physiological functions, with an emphasis on new findings of the past 5-10 yr. The medical and research communities first became aware of PTHrP because of its involvement in a common paraneoplastic syndrome. Now, research into the basic biology of PTHrP has suggested previously unrecognized connections to a variety of disease states such as osteoporosis, osteoarthritis, and breast cancer and has highlighted how PTHrP itself might be used in therapy for osteoporosis and diabetes. Therefore, the story of this remarkable protein is a paradigm for translational research, having gone from bedside to bench and now back to bedside.
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Affiliation(s)
- John J Wysolmerski
- Section of Endocrinology and Metabolism, Department of Internal Medicine, Yale School of Medicine, TAC S131, Box 208020, New Haven, Connecticut 06520-8020, USA.
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Kulkarni RN, Mizrachi EB, Ocana AG, Stewart AF. Human β-cell proliferation and intracellular signaling: driving in the dark without a road map. Diabetes 2012; 61:2205-13. [PMID: 22751699 PMCID: PMC3425429 DOI: 10.2337/db12-0018] [Citation(s) in RCA: 190] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
A major goal in diabetes research is to find ways to enhance the mass and function of insulin secreting β-cells in the endocrine pancreas to prevent and/or delay the onset or even reverse overt diabetes. In this Perspectives in Diabetes article, we highlight the contrast between the relatively large body of information that is available in regard to signaling pathways, proteins, and mechanisms that together provide a road map for efforts to regenerate β-cells in rodents versus the scant information in human β-cells. To reverse the state of ignorance regarding human β-cell signaling, we suggest a series of questions for consideration by the scientific community to construct a human β-cell proliferation road map. The hope is that the knowledge from the new studies will allow the community to move faster towards developing therapeutic approaches to enhance human β-cell mass in the long-term goal of preventing and/or curing type 1 and type 2 diabetes.
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Affiliation(s)
- Rohit N. Kulkarni
- Islet Cell Biology and Regenerative Medicine, Joslin Diabetes Center, Harvard Medical School, Boston, Massachusetts
- Department of Medicine, Harvard Medical School, Boston, Massachusetts
- Corresponding authors: Rohit N. Kulkarni, , and Andrew F. Stewart,
| | - Ernesto-Bernal Mizrachi
- Division of Metabolism, Endocrinology, and Diabetes, University of Michigan, Ann Arbor, Michigan
| | - Adolfo Garcia Ocana
- Division of Endocrinology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Andrew F. Stewart
- Division of Endocrinology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
- Corresponding authors: Rohit N. Kulkarni, , and Andrew F. Stewart,
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Metukuri MR, Zhang P, Basantani MK, Chin C, Stamateris RE, Alonso LC, Takane KK, Gramignoli R, Strom SC, O’Doherty RM, Stewart AF, Vasavada RC, Garcia-Ocaña A, Scott DK. ChREBP mediates glucose-stimulated pancreatic β-cell proliferation. Diabetes 2012; 61:2004-15. [PMID: 22586588 PMCID: PMC3402328 DOI: 10.2337/db11-0802] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Glucose stimulates rodent and human β-cell replication, but the intracellular signaling mechanisms are poorly understood. Carbohydrate response element-binding protein (ChREBP) is a lipogenic glucose-sensing transcription factor with unknown functions in pancreatic β-cells. We tested the hypothesis that ChREBP is required for glucose-stimulated β-cell proliferation. The relative expression of ChREBP was determined in liver and β-cells using quantitative RT-PCR (qRT-PCR), immunoblotting, and immunohistochemistry. Loss- and gain-of-function studies were performed using small interfering RNA and genetic deletion of ChREBP and adenoviral overexpression of ChREBP in rodent and human β-cells. Proliferation was measured by 5-bromo-2'-deoxyuridine incorporation, [(3)H]thymidine incorporation, and fluorescence-activated cell sorter analysis. In addition, the expression of cell cycle regulatory genes was measured by qRT-PCR and immunoblotting. ChREBP expression was comparable with liver in mouse pancreata and in rat and human islets. Depletion of ChREBP decreased glucose-stimulated proliferation in β-cells isolated from ChREBP(-/-) mice, in INS-1-derived 832/13 cells, and in primary rat and human β-cells. Furthermore, depletion of ChREBP decreased the glucose-stimulated expression of cell cycle accelerators. Overexpression of ChREBP amplified glucose-stimulated proliferation in rat and human β-cells, with concomitant increases in cyclin gene expression. In conclusion, ChREBP mediates glucose-stimulated proliferation in pancreatic β-cells.
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Affiliation(s)
- Mallikarjuna R. Metukuri
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania
- Laboratory of Signal Transduction, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina
| | - Pili Zhang
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Mahesh K. Basantani
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Connie Chin
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Rachel E. Stamateris
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Laura C. Alonso
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Karen K. Takane
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Roberto Gramignoli
- Department of Pathology, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Stephen C. Strom
- Department of Pathology, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Robert M. O’Doherty
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Andrew F. Stewart
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Rupangi C. Vasavada
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Adolfo Garcia-Ocaña
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Donald K. Scott
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania
- Corresponding author: Donald K. Scott,
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Kondegowda NG, Mozar A, Chin C, Otero A, Garcia-Ocaña A, Vasavada RC. Lactogens protect rodent and human beta cells against glucolipotoxicity-induced cell death through Janus kinase-2 (JAK2)/signal transducer and activator of transcription-5 (STAT5) signalling. Diabetologia 2012; 55:1721-32. [PMID: 22382519 DOI: 10.1007/s00125-012-2501-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2011] [Accepted: 01/11/2012] [Indexed: 01/09/2023]
Abstract
AIMS/HYPOTHESIS A leading cause of type 2 diabetes is a reduction in functional beta cell mass partly due to increased beta cell death, triggered by stressors such as glucolipotoxicity (GLT). This study evaluates the hypothesis that lactogens can protect beta cells against GLT and examines the mechanism behind the pro-survival effect. METHODS The effect of exogenous treatment or endogenous expression of lactogens on GLT-induced beta cell death was examined in INS-1 cells, and in rodent and human islets. The mechanism behind the pro-survival effect of lactogens was determined using an inhibitor, siRNAs, a dominant negative (DN) mutant, and Cre-lox-mediated gene deletion analysis. RESULTS Lactogens significantly protect INS-1 and primary rodent beta cells against GLT-induced cell death. The pro-survival effect of lactogens in rodent beta cells is mediated through activation of the Janus kinase-2 (JAK2)/signal transducer and activator of transcription-5 (STAT5) signalling pathway. Lactogen-induced increase in the anti-apoptotic B cell lymphoma-extra large (BCLXL) protein is required to mediate its pro-survival effects in both INS-1 cells and primary rodent beta cells. Most importantly, lactogens significantly protect human beta cells against GLT-induced cell death, and their pro-survival effect is also mediated through the JAK2/STAT5 pathway. CONCLUSIONS/INTERPRETATION These studies, together with previous work, clearly demonstrate the pro-survival nature of lactogens and identify the JAK2/STAT5 pathway as an important mediator of this effect in both rodent and human beta cells. Future studies will determine the effectiveness of this peptide in vivo in the pathophysiology of type 2 diabetes.
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Affiliation(s)
- N Guthalu Kondegowda
- Division of Endocrinology, University of Pittsburgh, 200 Lothrop St, BST-E1157, Pittsburgh, PA 15261, USA
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Molè D, Gentilin E, Gagliano T, Tagliati F, Bondanelli M, Pelizzo MR, Rossi M, Filieri C, Pansini G, degli Uberti EC, Zatelli MC. Protein kinase C: a putative new target for the control of human medullary thyroid carcinoma cell proliferation in vitro. Endocrinology 2012; 153:2088-98. [PMID: 22374978 DOI: 10.1210/en.2011-1988] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
We investigate the role of protein kinase C (PKC) in the control of medullary thyroid carcinoma (MTC) cell proliferation by a PKC inhibitor, Enzastaurin, in human MTC primary cultures and in the TT cell line. We found that PKC inhibition reduces cell proliferation by inducing caspase-mediated apoptosis and blocks the stimulatory effect of IGF-I on calcitonin secretion. Enzastaurin reduces PKCβII (Thr500) phosphorylation, indicating a direct involvement of this isoform as well as the phosphorylated levels of Akt (Ser 473) and glycogen synthase kinase (Ser9), PKC pathway downstream targets and pharmacodynamic markers for PKC inhibition. PKCβII and PKCδ enzyme isoforms expression and localization were investigated. These data indicate that in vitro PKC is involved in the control of human MTC proliferation and survival by modulating apoptosis, with a mechanism that implicates PKCβII inhibition and translocation in different subcellular compartments. Targeting PKC may represent a useful therapeutic approach for controlling MTC proliferation.
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Affiliation(s)
- Daniela Molè
- Section of Endocrinology, Department of Biomedical Sciences and Advanced Therapies, University of Ferrara, Via Savonarola 9, 44121 Ferrara, Italy
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Demirci C, Ernst S, Alvarez-Perez JC, Rosa T, Valle S, Shridhar V, Casinelli GP, Alonso LC, Vasavada RC, García-Ocana A. Loss of HGF/c-Met signaling in pancreatic β-cells leads to incomplete maternal β-cell adaptation and gestational diabetes mellitus. Diabetes 2012; 61:1143-52. [PMID: 22427375 PMCID: PMC3331762 DOI: 10.2337/db11-1154] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Hepatocyte growth factor (HGF) is a mitogen and insulinotropic agent for the β-cell. However, whether HGF/c-Met has a role in maternal β-cell adaptation during pregnancy is unknown. To address this issue, we characterized glucose and β-cell homeostasis in pregnant mice lacking c-Met in the pancreas (PancMet KO mice). Circulating HGF and islet c-Met and HGF expression were increased in pregnant mice. Importantly, PancMet KO mice displayed decreased β-cell replication and increased β-cell apoptosis at gestational day (GD)15. The decreased β-cell replication was associated with reductions in islet prolactin receptor levels, STAT5 nuclear localization and forkhead box M1 mRNA, and upregulation of p27. Furthermore, PancMet KO mouse β-cells were more sensitive to dexamethasone-induced cytotoxicity, whereas HGF protected human β-cells against dexamethasone in vitro. These detrimental alterations in β-cell proliferation and death led to incomplete maternal β-cell mass expansion in PancMet KO mice at GD19 and early postpartum periods. The decreased β-cell mass was accompanied by increased blood glucose, decreased plasma insulin, and impaired glucose tolerance. PancMet KO mouse islets failed to upregulate GLUT2 and pancreatic duodenal homeobox-1 mRNA, insulin content, and glucose-stimulated insulin secretion during gestation. These studies indicate that HGF/c-Met signaling is essential for maternal β-cell adaptation during pregnancy and that its absence/attenuation leads to gestational diabetes mellitus.
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Affiliation(s)
- Cem Demirci
- Department of Pediatrics, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Sara Ernst
- Division of Endocrinology and Metabolism Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Juan C. Alvarez-Perez
- Division of Endocrinology and Metabolism Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Taylor Rosa
- Division of Endocrinology and Metabolism Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Shelley Valle
- Division of Endocrinology and Metabolism Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Varsha Shridhar
- Division of Endocrinology and Metabolism Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Gabriella P. Casinelli
- Division of Endocrinology and Metabolism Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Laura C. Alonso
- Division of Endocrinology and Metabolism Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Rupangi C. Vasavada
- Division of Endocrinology and Metabolism Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Adolfo García-Ocana
- Division of Endocrinology and Metabolism Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
- Corresponding author: Adolfo Garcia-Ocaña,
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Huang S, Ouyang N, Lin L, Chen L, Wu W, Su F, Yao Y, Yao H. HGF-induced PKCζ activation increases functional CXCR4 expression in human breast cancer cells. PLoS One 2012; 7:e29124. [PMID: 22242160 PMCID: PMC3252308 DOI: 10.1371/journal.pone.0029124] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2011] [Accepted: 11/21/2011] [Indexed: 12/31/2022] Open
Abstract
The chemokine receptor CXCR4 and its ligand CXCL12 have been shown to mediate the metastasis of many malignant tumors including breast carcinoma. Interaction between hepatocyte growth factor (HGF) and the Met receptor tyrosine kinase mediates development and progression of cancers. HGF is able to induce CXCR4 expression and contributes to tumor cell invasiveness in breast carcinoma. However, the mechanism of the CXCR4 expression modulated by c-Met-HGF axis to enhance the metastatic behavior of breast cancer cells is still unclear. In this study, we found that HGF induced functional CXCR4 receptor expression in breast cancer cells. The effect of HGF was specifically mediated by PKCζ activity. After transfection with PKCζ-siRNA, the phosphorylation of PKCζ and CXCR4 was abrogated in breast cancer cells. Interference with the activation of Rac1, a downstream target of HGF, prevented the HGF-induced increase in PKCζ activity and CXCR4 levels. The HGF-induced, LY294002-sensitive translocation of PKCζ from cytosol to plasma membrane indicated that HGF was capable of activating PKCζ, probably via phosphoinositide (PI) 3-kinases. HGF treatment also increased MT1-MMP secretion. Inhibition of PKCζ, Rac-1 and phosphatidylinositol 3-kinase may attenuate MT1-MMP expression in cells exposed to HGF. Functional manifestation of the effects of HGF revealed an increased ability for migration, chemotaxis and metastasis in MDA-MB-436 cells in vitro and in vivo. Our findings thus provided evidence that the process of HGF-induced functional CXCR4 expression may involve PI 3-kinase and atypical PKCζ. Moreover, HGF may promote the invasiveness and metastasis of breast tumor xenografts in BALB/c-nu mice via the PKCζ-mediated pathway, while suppression of PKCζ by RNA interference may abrogate cancer cell spreading.
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Affiliation(s)
- Songyin Huang
- Department of Laboratory, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China
| | - Nengyong Ouyang
- Department of Gynaecology and Obstetrics, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China
| | - Ling Lin
- Breast Tumor Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China
- Department of Rheumatology, The First Affiliated Hospital, Shantou University Medical College, Shantou City, Guangdong, China
| | - Lili Chen
- Breast Tumor Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China
| | - Wei Wu
- Breast Tumor Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China
| | - Fengxi Su
- Breast Tumor Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China
| | - Yandan Yao
- Breast Tumor Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China
| | - Herui Yao
- Breast Tumor Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China
- Department of Oncology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China
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Williams K, Abanquah D, Joshi-Gokhale S, Otero A, Lin H, Guthalu NK, Zhang X, Mozar A, Bisello A, Stewart AF, Garcia-Ocaña A, Vasavada RC. Systemic and acute administration of parathyroid hormone-related peptide(1-36) stimulates endogenous beta cell proliferation while preserving function in adult mice. Diabetologia 2011; 54:2867-77. [PMID: 21800111 DOI: 10.1007/s00125-011-2260-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2011] [Accepted: 06/03/2011] [Indexed: 11/25/2022]
Abstract
AIMS/HYPOTHESIS A major focus in the treatment of diabetes is to identify factors that stimulate endogenous beta cell growth while preserving function. The first 36 amino acids of parathyroid hormone-related protein (PTHrP) are sufficient to enhance proliferation and function in rodent and human beta cells in vitro. This study examined whether acute and systemic administration of the amino-terminal PTHrP(1-36) peptide can achieve similar effects in rodent beta cells in vivo. METHODS Adult male mice were injected with 40, 80 or 160 μg of PTHrP(1-36) per kg body weight or with vehicle for 25 days. Glucose and beta cell homeostasis, as well as expression of differentiation markers and cell cycle genes were analysed. RESULTS All three doses of PTHrP(1-36) significantly enhanced beta cell proliferation in vivo at day 25, with 160 μg/kg PTHrP(1-36) increasing proliferation as early as day 5. Importantly, the two higher doses of PTHrP(1-36) caused a significant 30% expansion of beta cell mass, with a short-term improvement in glucose tolerance. PTHrP(1-36) did not cause hypercalcaemia, or change islet number, beta cell size, beta cell death or expression of differentiation markers. Analysis of islet G1/S cell cycle proteins revealed that chronic overabundance of PTHrP(1-139) in the beta cell significantly increased the cell cycle activator cyclin D2 and decreased levels of cyclin-dependent kinase 4 inhibitor (p16( Ink4a ) [Ink4a also known as Cdkn2a]), but acute treatment with PTHrP(1-36) did not. CONCLUSIONS/INTERPRETATION Acute and systemic administration of PTHrP(1-36) increases rodent beta cell proliferation and mass without negatively affecting function or survival. These findings highlight the future potential therapeutic effectiveness of this peptide under diabetes-related pathophysiological conditions.
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Affiliation(s)
- K Williams
- Division of Endocrinology, University of Pittsburgh, 200 Lothrop St, BST-E1157, Pittsburgh, PA 15261, USA
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Velazquez-Garcia S, Valle S, Rosa TC, Takane KK, Demirci C, Alvarez-Perez JC, Mellado-Gil JM, Ernst S, Scott DK, Vasavada RC, Alonso LC, Garcia-Ocaña A. Activation of protein kinase C-ζ in pancreatic β-cells in vivo improves glucose tolerance and induces β-cell expansion via mTOR activation. Diabetes 2011; 60:2546-59. [PMID: 21911744 PMCID: PMC3178296 DOI: 10.2337/db10-1783] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
OBJECTIVE PKC-ζ activation is a key signaling event for growth factor-induced β-cell replication in vitro. However, the effect of direct PKC-ζ activation in the β-cell in vivo is unknown. In this study, we examined the effects of PKC-ζ activation in β-cell expansion and function in vivo in mice and the mechanisms associated with these effects. RESEARCH DESIGN AND METHODS We characterized glucose homeostasis and β-cell phenotype of transgenic (TG) mice with constitutive activation of PKC-ζ in the β-cell. We also analyzed the expression and regulation of signaling pathways, G1/S cell cycle molecules, and β-cell functional markers in TG and wild-type mouse islets. RESULTS TG mice displayed increased plasma insulin, improved glucose tolerance, and enhanced insulin secretion with concomitant upregulation of islet insulin and glucokinase expression. In addition, TG mice displayed increased β-cell proliferation, size, and mass compared with wild-type littermates. The increase in β-cell proliferation was associated with upregulation of cyclins D1, D2, D3, and A and downregulation of p21. Phosphorylation of D-cyclins, known to initiate their rapid degradation, was reduced in TG mouse islets. Phosphorylation/inactivation of GSK-3β and phosphorylation/activation of mTOR, critical regulators of D-cyclin expression and β-cell proliferation, were enhanced in TG mouse islets, without changes in Akt phosphorylation status. Rapamycin treatment in vivo eliminated the increases in β-cell proliferation, size, and mass; the upregulation of cyclins Ds and A in TG mice; and the improvement in glucose tolerance-identifying mTOR as a novel downstream mediator of PKC-ζ-induced β-cell replication and expansion in vivo. CONCLUSIONS PKC:-ζ, through mTOR activation, modifies the expression pattern of β-cell cycle molecules leading to increased β-cell replication and mass with a concomitant enhancement in β-cell function. Approaches to enhance PKC-ζ activity may be of value as a therapeutic strategy for the treatment of diabetes.
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Affiliation(s)
- Silvia Velazquez-Garcia
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Shelley Valle
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Taylor C. Rosa
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Karen K. Takane
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Cem Demirci
- Department of Pediatrics, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Juan C. Alvarez-Perez
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Jose M. Mellado-Gil
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Sara Ernst
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Donald K. Scott
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Rupangi C. Vasavada
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Laura C. Alonso
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Adolfo Garcia-Ocaña
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania
- Corresponding author: Adolfo Garcia-Ocaña,
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Ohtani M, Ohura K, Oka T. Involvement of P2X receptors in the regulation of insulin secretion, proliferation and survival in mouse pancreatic β-cells. Cell Physiol Biochem 2011; 28:355-66. [PMID: 21865744 DOI: 10.1159/000331752] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/30/2011] [Indexed: 12/18/2022] Open
Abstract
In order to clarify the functional role of ionotropic purinergic (P2X) receptors in pancreatic β-cells, we examined the effect of several P2 receptor agonists and antagonists on insulin secretion by mouse pancreatic islets, mouse Beta-TC6 cell proliferation and survival of dispersed islet cells in culture. Reverse transcription-polymerase chain reaction (RT-PCR) analysis showed the expression of mRNAs of P2X(4) receptor in mouse islets and P2X(1), P2X(2), P2X(3), P2X(4), P2X(5) and P2X(7) receptors in Beta-TC6 cells. The presence of P2X(4) receptor proteins in islets and Beta-TC6 cells was confirmed by immunofluorescent staining and Western blot analysis. We have previously found that the functional P2Y(1) receptor but not P2Y(2) and P2Y(4) receptors was present in islets. In this study we found that a nonspecific P2 receptor agonist, ATP (1 μM) stimulated insulin secretion by islets in the presence of high glucose (20 mM) in culture. The effect of ATP was partially inhibited by a P2 receptor antagonist PPADS as well as a P2Y(1) receptor antagonist MRS2179. In addition, a P2X(4) receptor potentiator ivermectin per se augmented glucose-induced insulin secretion and slightly potentiated the effect of ATP. These results suggested the involvement of P2Y(1)and P2X receptors. We also found that ATP inhibited proliferation of Beta-TC6 cells in a concentration-dependent manner during 72 h culture. The inhibitory effect of ATP was completely reversed by PPADS and partially by treating cells with small interfering RNA targeted for P2X(4) receptor mRNA. Furthermore, we found that the phosphorylation of the extracellular signal-regulated kinase 1 and 2 (ERK1/2) was suppressed by treatment with ATP in Beta-TC6 cells. In addition, we found that ATP reduced the cell viability and DNA synthesis of islet cells in culture. The effect of ATP on the cell viability was blocked by PPADS or MRS2179. These results suggested that P2X receptors as well as the P2Y(1) receptor played a role in the modulation of insulin secretion, proliferation and cell viability in mouse pancreatic β-cells.
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Affiliation(s)
- Masahiro Ohtani
- Department of Pharmacology, Osaka Dental University, Hirakata, Japan
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Ernst S, Demirci C, Valle S, Velazquez-Garcia S, Garcia-Ocaña A. Mechanisms in the adaptation of maternal β-cells during pregnancy. ACTA ACUST UNITED AC 2011; 1:239-248. [PMID: 21845205 DOI: 10.2217/dmt.10.24] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Pancreatic β-cell mass adapts to changing insulin demands in the body. One of the most amazing reversible β-cell adaptations occurs during pregnancy and postpartum conditions. During pregnancy, the increase in maternal insulin resistance is compensated by maternal β-cell hyperplasia and hyperfunctionality to maintain normal blood glucose. Although the cellular mechanisms involved in maternal β-cell expansion have been studied in detail in rodents, human studies are very sparse. A summary of these studies in rodents and humans is described below. Since β-cell mass expands during pregnancy, unraveling the endocrine/paracrine/autocrine molecular mechanisms responsible for these effects can be of great importance for predicting and treating gestational diabetes and for finding new cues that induce β-cell regeneration in diabetes. In addition to the well known implication of lactogens during maternal β-cell expansion, additional participants are being discovered such as serotonin and HGF. Transcription factors, such as hepatocyte nuclear factor-4α and the forkhead box protein-M1, and cell cycle regulators, such as menin, p27 and p18, are important intracellular signals responsible for these effects. In this article, we summarize and discuss novel studies uncovering molecular mechanisms involved in the maternal β-cell adaptive expansion during pregnancy.
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Affiliation(s)
- Sara Ernst
- Department of Medicine, Division of Endocrinology & Metabolism, University of Pittsburgh, 200 Lothrop St. BST-E1140, Pittsburgh, PA 15261, USA
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Mellado-Gil J, Rosa TC, Demirci C, Gonzalez-Pertusa JA, Velazquez-Garcia S, Ernst S, Valle S, Vasavada RC, Stewart AF, Alonso LC, Garcia-Ocaña A. Disruption of hepatocyte growth factor/c-Met signaling enhances pancreatic beta-cell death and accelerates the onset of diabetes. Diabetes 2011; 60:525-36. [PMID: 20980460 PMCID: PMC3028352 DOI: 10.2337/db09-1305] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
OBJECTIVE To determine the role of hepatocyte growth factor (HGF)/c-Met on β-cell survival in diabetogenic conditions in vivo and in response to cytokines in vitro. RESEARCH DESIGN AND METHODS We generated pancreas-specific c-Met-null (PancMet KO) mice and characterized their response to diabetes induced by multiple low-dose streptozotocin (MLDS) administration. We also analyzed the effect of HGF/c-Met signaling in vitro on cytokine-induced β-cell death in mouse and human islets, specifically examining the role of nuclear factor (NF)-κB. RESULTS Islets exposed in vitro to cytokines or from MLDS-treated mice displayed significantly increased HGF and c-Met levels, suggesting a potential role for HGF/c-Met in β-cell survival against diabetogenic agents. Adult PancMet KO mice displayed normal glucose and β-cell homeostasis, indicating that pancreatic c-Met loss is not detrimental for β-cell growth and function under basal conditions. However, PancMet KO mice were more susceptible to MLDS-induced diabetes. They displayed higher blood glucose levels, marked hypoinsulinemia, and reduced β-cell mass compared with wild-type littermates. PancMet KO mice showed enhanced intraislet infiltration, islet nitric oxide (NO) and chemokine production, and β-cell apoptosis. c-Met-null β-cells were more sensitive to cytokine-induced cell death in vitro, an effect mediated by NF-κB activation and NO production. Conversely, HGF treatment decreased p65/NF-κB activation and fully protected mouse and, more important, human β-cells against cytokines. CONCLUSIONS These results show that HGF/c-Met is critical for β-cell survival by attenuating NF-κB signaling and suggest that activation of the HGF/c-Met signaling pathway represents a novel strategy for enhancing β-cell protection.
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Affiliation(s)
- Jose Mellado-Gil
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Taylor C. Rosa
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Cem Demirci
- Department of Pediatrics, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Jose A. Gonzalez-Pertusa
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Silvia Velazquez-Garcia
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Sara Ernst
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Shelley Valle
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Rupangi C. Vasavada
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Andrew F. Stewart
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Laura C. Alonso
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Adolfo Garcia-Ocaña
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania
- Corresponding author: Adolfo Garcia-Ocaña,
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Guthalu Kondegowda N, Joshi-Gokhale S, Harb G, Williams K, Zhang XY, Takane KK, Zhang P, Scott DK, Stewart AF, Garcia-Ocaña A, Vasavada RC. Parathyroid hormone-related protein enhances human ß-cell proliferation and function with associated induction of cyclin-dependent kinase 2 and cyclin E expression. Diabetes 2010; 59:3131-8. [PMID: 20876711 PMCID: PMC2992775 DOI: 10.2337/db09-1796] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE Inducing human β-cell growth while enhancing function is a major goal in the treatment of diabetes. Parathyroid hormone-related protein (PTHrP) enhances rodent β-cell growth and function through the parathyroid hormone-1 receptor (PTH1R). Based on this, we hypothesized that PTH1R is expressed in human β-cells and that PTHrP has the potential to enhance human β-cell proliferation and/or function. RESEARCH DESIGN AND METHODS PTH1R expression, β-cell proliferation, glucose-stimulated insulin secretion (GSIS), and expression of differentiation and cell-cycle genes were analyzed in human islets transduced with adenoviral PTHrP constructs or treated with PTHrP peptides. The effect of overexpression of late G1/S cell cycle molecules was also assessed on human β-cell proliferation. RESULTS We found that human β-cells express PTH1R. More importantly, overexpression of PTHrP causes a significant approximately threefold increase in human β-cell proliferation. Furthermore, the amino terminus PTHrP(1-36) peptide is sufficient to increase replication as well as expression of the late G1/S cell-cycle proteins cyclin E and cyclin-dependent kinase 2 (cdk2) in human islets. Notably, PTHrP(1-36) also enhances GSIS. Finally, overexpression of cyclin E alone, but not cdk2, augments human β-cell proliferation, and when both molecules are expressed simultaneously there is a further marked synergistic increase in replication. CONCLUSIONS PTHrP(1-36) peptide enhances human β-cell proliferation as well as function, with associated upregulation of two specific cell-cycle activators that together can induce human β-cell proliferation several fold. The future therapeutic potential of PTHrP(1-36) for the treatment of diabetes is especially relevant given the complementary therapeutic efficacy of PTHrP(1-36) in postmenopausal osteoporosis.
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