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Neukam M, Sala P, Brunner AD, Ganß K, Palladini A, Grzybek M, Topcheva O, Vasiljević J, Broichhagen J, Johnsson K, Kurth T, Mann M, Coskun Ü, Solimena M. Purification of time-resolved insulin granules reveals proteomic and lipidomic changes during granule aging. Cell Rep 2024; 43:113836. [PMID: 38421874 DOI: 10.1016/j.celrep.2024.113836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 12/29/2023] [Accepted: 02/05/2024] [Indexed: 03/02/2024] Open
Abstract
Endocrine cells employ regulated exocytosis of secretory granules to secrete hormones and neurotransmitters. Secretory granule exocytosis depends on spatiotemporal variables such as proximity to the plasma membrane and age, with newly generated granules being preferentially released. Despite recent advances, we lack a comprehensive view of the molecular composition of insulin granules and associated changes over their lifetime. Here, we report a strategy for the purification of insulin secretory granules of distinct age from insulinoma INS-1 cells. Tagging the granule-resident protein phogrin with a cleavable CLIP tag, we obtain intact fractions of age-distinct granules for proteomic and lipidomic analyses. We find that the lipid composition changes over time, along with the physical properties of the membrane, and that kinesin-1 heavy chain (KIF5b) as well as Ras-related protein 3a (RAB3a) associate preferentially with younger granules. Further, we identify the Rho GTPase-activating protein (ARHGAP1) as a cytosolic factor associated with insulin granules.
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Affiliation(s)
- Martin Neukam
- Molecular Diabetology, University Hospital and Faculty of Medicine Carl Gustav Carus, TU Dresden, 01307 Dresden, Germany; Paul Langerhans Institute Dresden (PLID) of the Helmholtz Center Munich at the University Hospital Carl Gustav Carus and Faculty of Medicine of the TU Dresden, 01307 Dresden, Germany; German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany.
| | - Pia Sala
- Paul Langerhans Institute Dresden (PLID) of the Helmholtz Center Munich at the University Hospital Carl Gustav Carus and Faculty of Medicine of the TU Dresden, 01307 Dresden, Germany; German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany; Center of Membrane Biochemistry and Lipid Research, University Hospital and Faculty of Medicine Carl Gustav Carus, TU Dresden, 01307 Dresden, Germany
| | | | - Katharina Ganß
- Molecular Diabetology, University Hospital and Faculty of Medicine Carl Gustav Carus, TU Dresden, 01307 Dresden, Germany; Paul Langerhans Institute Dresden (PLID) of the Helmholtz Center Munich at the University Hospital Carl Gustav Carus and Faculty of Medicine of the TU Dresden, 01307 Dresden, Germany; German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany
| | - Alessandra Palladini
- Paul Langerhans Institute Dresden (PLID) of the Helmholtz Center Munich at the University Hospital Carl Gustav Carus and Faculty of Medicine of the TU Dresden, 01307 Dresden, Germany; German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany; Center of Membrane Biochemistry and Lipid Research, University Hospital and Faculty of Medicine Carl Gustav Carus, TU Dresden, 01307 Dresden, Germany
| | - Michal Grzybek
- Paul Langerhans Institute Dresden (PLID) of the Helmholtz Center Munich at the University Hospital Carl Gustav Carus and Faculty of Medicine of the TU Dresden, 01307 Dresden, Germany; German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany; Center of Membrane Biochemistry and Lipid Research, University Hospital and Faculty of Medicine Carl Gustav Carus, TU Dresden, 01307 Dresden, Germany
| | - Oleksandra Topcheva
- Molecular Diabetology, University Hospital and Faculty of Medicine Carl Gustav Carus, TU Dresden, 01307 Dresden, Germany; Paul Langerhans Institute Dresden (PLID) of the Helmholtz Center Munich at the University Hospital Carl Gustav Carus and Faculty of Medicine of the TU Dresden, 01307 Dresden, Germany; German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany
| | - Jovana Vasiljević
- Molecular Diabetology, University Hospital and Faculty of Medicine Carl Gustav Carus, TU Dresden, 01307 Dresden, Germany; Paul Langerhans Institute Dresden (PLID) of the Helmholtz Center Munich at the University Hospital Carl Gustav Carus and Faculty of Medicine of the TU Dresden, 01307 Dresden, Germany; German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany
| | - Johannes Broichhagen
- Department of Chemical Biology, Max Planck Institute for Medical Research, 69120 Heidelberg, Germany
| | - Kai Johnsson
- Department of Chemical Biology, Max Planck Institute for Medical Research, 69120 Heidelberg, Germany
| | - Thomas Kurth
- TU Dresden, Center for Molecular and Cellular Bioengineering (CMCB), Technology Platform, Electron Microscopy and Histology Facility, 01307 Dresden, Saxony, Germany
| | - Matthias Mann
- Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Ünal Coskun
- Paul Langerhans Institute Dresden (PLID) of the Helmholtz Center Munich at the University Hospital Carl Gustav Carus and Faculty of Medicine of the TU Dresden, 01307 Dresden, Germany; German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany; Center of Membrane Biochemistry and Lipid Research, University Hospital and Faculty of Medicine Carl Gustav Carus, TU Dresden, 01307 Dresden, Germany
| | - Michele Solimena
- Molecular Diabetology, University Hospital and Faculty of Medicine Carl Gustav Carus, TU Dresden, 01307 Dresden, Germany; Paul Langerhans Institute Dresden (PLID) of the Helmholtz Center Munich at the University Hospital Carl Gustav Carus and Faculty of Medicine of the TU Dresden, 01307 Dresden, Germany; German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany.
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Umbayev B, Saliev T, Safarova (Yantsen) Y, Yermekova A, Olzhayev F, Bulanin D, Tsoy A, Askarova S. The Role of Cdc42 in the Insulin and Leptin Pathways Contributing to the Development of Age-Related Obesity. Nutrients 2023; 15:4964. [PMID: 38068822 PMCID: PMC10707920 DOI: 10.3390/nu15234964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 11/22/2023] [Accepted: 11/26/2023] [Indexed: 12/18/2023] Open
Abstract
Age-related obesity significantly increases the risk of chronic diseases such as type 2 diabetes, cardiovascular diseases, hypertension, and certain cancers. The insulin-leptin axis is crucial in understanding metabolic disturbances associated with age-related obesity. Rho GTPase Cdc42 is a member of the Rho family of GTPases that participates in many cellular processes including, but not limited to, regulation of actin cytoskeleton, vesicle trafficking, cell polarity, morphology, proliferation, motility, and migration. Cdc42 functions as an integral part of regulating insulin secretion and aging. Some novel roles for Cdc42 have also been recently identified in maintaining glucose metabolism, where Cdc42 is involved in controlling blood glucose levels in metabolically active tissues, including skeletal muscle, adipose tissue, pancreas, etc., which puts this protein in line with other critical regulators of glucose metabolism. Importantly, Cdc42 plays a vital role in cellular processes associated with the insulin and leptin signaling pathways, which are integral elements involved in obesity development if misregulated. Additionally, a change in Cdc42 activity may affect senescence, thus contributing to disorders associated with aging. This review explores the complex relationships among age-associated obesity, the insulin-leptin axis, and the Cdc42 signaling pathway. This article sheds light on the vast molecular web that supports metabolic dysregulation in aging people. In addition, it also discusses the potential therapeutic implications of the Cdc42 pathway to mitigate obesity since some new data suggest that inhibition of Cdc42 using antidiabetic drugs or antioxidants may promote weight loss in overweight or obese patients.
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Affiliation(s)
- Bauyrzhan Umbayev
- National Laboratory Astana, Nazarbayev University, Astana 010000, Kazakhstan; (Y.S.); (A.Y.); (F.O.); (A.T.); (S.A.)
| | - Timur Saliev
- S.D. Asfendiyarov Kazakh National Medical University, Almaty 050012, Kazakhstan;
| | - Yuliya Safarova (Yantsen)
- National Laboratory Astana, Nazarbayev University, Astana 010000, Kazakhstan; (Y.S.); (A.Y.); (F.O.); (A.T.); (S.A.)
| | - Aislu Yermekova
- National Laboratory Astana, Nazarbayev University, Astana 010000, Kazakhstan; (Y.S.); (A.Y.); (F.O.); (A.T.); (S.A.)
| | - Farkhad Olzhayev
- National Laboratory Astana, Nazarbayev University, Astana 010000, Kazakhstan; (Y.S.); (A.Y.); (F.O.); (A.T.); (S.A.)
| | - Denis Bulanin
- Department of Biomedical Sciences, School of Medicine, Nazarbayev University, Astana 010000, Kazakhstan;
| | - Andrey Tsoy
- National Laboratory Astana, Nazarbayev University, Astana 010000, Kazakhstan; (Y.S.); (A.Y.); (F.O.); (A.T.); (S.A.)
| | - Sholpan Askarova
- National Laboratory Astana, Nazarbayev University, Astana 010000, Kazakhstan; (Y.S.); (A.Y.); (F.O.); (A.T.); (S.A.)
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Ghimire K, Kale A, Li J, Julovi SM, O'Connell P, Grey ST, Hawthorne WJ, Gunton JE, Rogers NM. A metabolic role for CD47 in pancreatic β cell insulin secretion and islet transplant outcomes. Sci Transl Med 2023; 15:eadd2387. [PMID: 37820008 DOI: 10.1126/scitranslmed.add2387] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Accepted: 09/18/2023] [Indexed: 10/13/2023]
Abstract
Diabetes is a global public health burden and is characterized clinically by relative or absolute insulin deficiency. Therapeutic agents that stimulate insulin secretion and improve insulin sensitivity are in high demand as treatment options. CD47 is a cell surface glycoprotein implicated in multiple cellular functions including recognition of self, angiogenesis, and nitric oxide signaling; however, its role in the regulation of insulin secretion remains unknown. Here, we demonstrate that CD47 receptor signaling inhibits insulin release from human as well as mouse pancreatic β cells and that it can be pharmacologically exploited to boost insulin secretion in both models. CD47 depletion stimulated insulin granule exocytosis via activation of the Rho GTPase Cdc42 in β cells and improved glucose clearance and insulin sensitivity in vivo. CD47 blockade enhanced syngeneic islet transplantation efficiency and expedited the return to euglycemia in streptozotocin-induced diabetic mice. Further, anti-CD47 antibody treatment delayed the onset of diabetes in nonobese diabetic (NOD) mice and protected them from overt diabetes. Our findings identify CD47 as a regulator of insulin secretion, and its manipulation in β cells offers a therapeutic opportunity for diabetes and islet transplantation by correcting insulin deficiency.
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Affiliation(s)
- Kedar Ghimire
- Centre for Transplant and Renal Research, Westmead Institute for Medical Research (WIMR), University of Sydney, Sydney, NSW 2145, Australia
- Westmead Clinical School, Faculty of Medicine and Health, University of Sydney, Sydney, NSW 2145, Australia
| | - Atharva Kale
- Centre for Transplant and Renal Research, Westmead Institute for Medical Research (WIMR), University of Sydney, Sydney, NSW 2145, Australia
| | - Jennifer Li
- Centre for Transplant and Renal Research, Westmead Institute for Medical Research (WIMR), University of Sydney, Sydney, NSW 2145, Australia
| | - Sohel M Julovi
- Centre for Transplant and Renal Research, Westmead Institute for Medical Research (WIMR), University of Sydney, Sydney, NSW 2145, Australia
| | - Philip O'Connell
- Centre for Transplant and Renal Research, Westmead Institute for Medical Research (WIMR), University of Sydney, Sydney, NSW 2145, Australia
- Westmead Clinical School, Faculty of Medicine and Health, University of Sydney, Sydney, NSW 2145, Australia
| | - Shane T Grey
- Transplantation Immunology Laboratory, Garvan Institute of Medical Research, Darlinghurst, NSW 2010, Australia
- School of Biotechnology and Biomolecular Sciences, Faculty of Science, University of New South Wales, Sydney, NSW 2052, Australia
| | - Wayne J Hawthorne
- Centre for Transplant and Renal Research, Westmead Institute for Medical Research (WIMR), University of Sydney, Sydney, NSW 2145, Australia
- Westmead Clinical School, Faculty of Medicine and Health, University of Sydney, Sydney, NSW 2145, Australia
| | - Jenny E Gunton
- Westmead Clinical School, Faculty of Medicine and Health, University of Sydney, Sydney, NSW 2145, Australia
- Centre for Diabetes, Obesity and Endocrinology, WIMR, University of Sydney, Sydney, NSW 2145, Australia
| | - Natasha M Rogers
- Centre for Transplant and Renal Research, Westmead Institute for Medical Research (WIMR), University of Sydney, Sydney, NSW 2145, Australia
- Westmead Clinical School, Faculty of Medicine and Health, University of Sydney, Sydney, NSW 2145, Australia
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Harada K, Takashima M, Kitaguchi T, Tsuboi T. F-actin determines the time-dependent shift in docking dynamics of glucagon-like peptide-1 granules upon stimulation of secretion. FEBS Lett 2023; 597:657-671. [PMID: 36694275 DOI: 10.1002/1873-3468.14580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 01/09/2023] [Accepted: 01/09/2023] [Indexed: 01/26/2023]
Abstract
Although exocytosis can be categorized into several forms based on docking dynamics, temporal regulatory mechanisms of the exocytotic forms are unclear. We explored the dynamics of glucagon-like peptide-1 (GLP-1) exocytosis in murine GLUTag cells (GLP-1-secreting enteroendocrine L-cells) upon stimulation with deoxycholic acid (DCA) or high K+ to elucidate the mechanisms regulating the balance between the different types of exocytotic forms (pre-docked with the plasma membrane before stimulation; docked after stimulation and subsequently fused; or rapidly recruited and fused after stimulation, without stable docking). GLP-1 exocytosis showed a biphasic pattern, and we found that most exocytosis was from the pre-docked granules with the plasma membrane before stimulation, or granules rapidly fused to the plasma membrane without docking after stimulation. In contrast, granules docked with the plasma membrane after stimuli and eventually fused were predominant thereafter. Inhibition of actin polymerization suppressed exocytosis of the pre-docked granules. These results suggest that the docking dynamics of GLP-1 granules shows a time-dependent biphasic shift, which is determined by interaction with F-actin.
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Affiliation(s)
- Kazuki Harada
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Japan
| | - Maoko Takashima
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Japan
| | - Tetsuya Kitaguchi
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan
| | - Takashi Tsuboi
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Japan
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Dissanayake WC, Shepherd PR. β-cells retain a pool of insulin-containing secretory vesicles regulated by adherens junctions and the cadherin binding protein p120 catenin. J Biol Chem 2022; 298:102240. [PMID: 35809641 PMCID: PMC9358467 DOI: 10.1016/j.jbc.2022.102240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 06/16/2022] [Accepted: 06/17/2022] [Indexed: 11/03/2022] Open
Abstract
The β-cells of the islets of Langerhans are the sole producers of insulin in the human body. In response to rising glucose levels, insulin-containing vesicles inside β-cells fuse with the plasma membrane and release their cargo. However, the mechanisms regulating this process are only partly understood. Previous evidence indicated reductions in α-catenin elevate insulin release, while reductions in β-catenin decrease insulin release. α- and β-catenin contribute to cellular regulation in a range of ways but one is as members of the adherens junction complex and these contribute to the development of cell polarity in b-cells. Therefore, we investigated the effects of adherens junctions on insulin release. We show in INS-1E β-cells knockdown of either E- or N-cadherin had only small effects on insulin secretion, but simultaneous knockout of both cadherins resulted in a significant increase in basal insulin release to the same level as glucose-stimulated release. This double knockdown also significantly attenuated levels of p120 catenin, a cadherin binding partner involved in regulating cadherin turnover. Conversely, reducing p120 catenin levels with siRNA destabilized both E- and N-cadherin, and this was also associated with an increase in levels of insulin secreted from INS-1E cells. Furthermore, there were also changes in these cells consistent with higher insulin release, namely reductions in levels of F-actin and increased intracellular free Ca2+ levels in response to KCl-induced membrane depolarization. Taken together, these data provide evidence that adherens junctions play important roles in retaining a pool of insulin secretory vesicles within the cell and establish a role for p120 catenin in regulating this process.
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Affiliation(s)
- Waruni C Dissanayake
- Department of Molecular Medicine and Pathology, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand; Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand
| | - Peter R Shepherd
- Department of Molecular Medicine and Pathology, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand; Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand.
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Chatterjee Bhowmick D, Aslamy A, Bhattacharya S, Oh E, Ahn M, Thurmond DC. DOC2b Enhances β-Cell Function via a Novel Tyrosine Phosphorylation-Dependent Mechanism. Diabetes 2022; 71:1246-1260. [PMID: 35377441 PMCID: PMC9163558 DOI: 10.2337/db21-0681] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 03/13/2022] [Indexed: 11/13/2022]
Abstract
Double C2 domain Β (DOC2b) protein is required for glucose-stimulated insulin secretion (GSIS) in β-cells, the underlying mechanism of which remains unresolved. Our biochemical analysis using primary human islets and human and rodent clonal β-cells revealed that DOC2b is tyrosine phosphorylated within 2 min of glucose stimulation, and Src family kinase member YES is required for this process. Biochemical and functional analysis using DOC2bY301 mutants revealed the requirement of Y301 phosphorylation for the interaction of DOC2b with YES kinase and increased content of VAMP2, a protein on insulin secretory granules, at the plasma membrane (PM), concomitant with DOC2b-mediated enhancement of GSIS in β-cells. Coimmunoprecipitation studies demonstrated an increased association of DOC2b with ERM family proteins in β-cells following glucose stimulation or pervanadate treatment. Y301 phosphorylation-competent DOC2b was required to increase ERM protein activation, and ERM protein knockdown impaired DOC2b-mediated boosting of GSIS, suggesting that tyrosine-phosphorylated DOC2b regulates GSIS via ERM-mediated granule localization to the PM. Taken together, these results demonstrate the glucose-induced posttranslational modification of DOC2b in β-cells, pinpointing the kinase, site of action, and downstream signaling events and revealing a regulatory role of YES kinase at various steps in GSIS. This work will enhance the development of novel therapeutic strategies to restore glucose homeostasis in diabetes.
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Affiliation(s)
- Diti Chatterjee Bhowmick
- Department of Molecular and Cellular Endocrinology, Diabetes and Metabolic Research Institute, Beckman Research Institute of City of Hope, Duarte, CA
| | - Arianne Aslamy
- Department of Medicine, Cedars-Sinai Medical Center, West Hollywood, CA
| | | | - Eunjin Oh
- Department of Molecular and Cellular Endocrinology, Diabetes and Metabolic Research Institute, Beckman Research Institute of City of Hope, Duarte, CA
| | - Miwon Ahn
- Department of Molecular and Cellular Endocrinology, Diabetes and Metabolic Research Institute, Beckman Research Institute of City of Hope, Duarte, CA
| | - Debbie C. Thurmond
- Department of Molecular and Cellular Endocrinology, Diabetes and Metabolic Research Institute, Beckman Research Institute of City of Hope, Duarte, CA
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Kowluru A, Gleason NF. Underappreciated roles for Rho GDP dissociation inhibitors (RhoGDIs) in cell function: Lessons learned from the pancreatic islet β-cell. Biochem Pharmacol 2022; 197:114886. [PMID: 34968495 PMCID: PMC8858860 DOI: 10.1016/j.bcp.2021.114886] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 12/10/2021] [Accepted: 12/13/2021] [Indexed: 11/02/2022]
Abstract
Rho subfamily of G proteins (e.g., Rac1) have been implicated in glucose-stimulated insulin secretion from the pancreatic β-cell. Interestingly, metabolic stress (e.g., chronic exposure to high glucose) results in sustained activation of Rac1 leading to increased oxidative stress, impaired insulin secretion and β-cell dysfunction. Activation-deactivation of Rho G proteins is mediated by three classes of regulatory proteins, namely the guanine nucleotide exchange factors (GEFs), which facilitate the conversion of inactive G proteins to their active conformations; the GTPase-activating proteins (GAPs), which convert the active G proteins to their inactive forms); and the GDP-dissociation inhibitors (GDIs), which prevent the dissociation of GDP from G proteins. Contrary to a large number of GEFs (82 members) and GAPs (69 members), only three members of RhoGDIs (RhoGDIα, RhoGDIβ and RhoGDIγ) are expressed in mammalian cells.Even though relatively smaller in number, the GDIs appear to play essential roles in G protein function (e.g., subcellular targeting) for effector activation and cell regulation. Emerging evidence also suggests that the GDIs are functionally regulated via post-translational modification (e.g., phosphorylation) and by lipid second messengers, lipid kinases and lipid phosphatases. We highlight the underappreciated regulatory roles of RhoGDI-Rho G protein signalome in islet β-cell function in health and metabolic stress. Potential knowledge gaps in the field, and directions for future research for the identification of novel therapeutic targets to loss of functional β-cell mass under the duress of metabolic stress are highlighted.
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Affiliation(s)
- Anjaneyulu Kowluru
- Biomedical Research Service, John D. Dingell VA Medical Center and Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, MI 48201, USA.
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Sørensen AE, van Poppel MNM, Desoye G, Simmons D, Damm P, Jensen DM, Dalgaard LT. The Temporal Profile of Circulating miRNAs during Gestation in Overweight and Obese Women with or without Gestational Diabetes Mellitus. Biomedicines 2022; 10:biomedicines10020482. [PMID: 35203692 PMCID: PMC8962411 DOI: 10.3390/biomedicines10020482] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 02/10/2022] [Accepted: 02/14/2022] [Indexed: 12/12/2022] Open
Abstract
Circulating non-coding microRNAs (miRNAs) are important for placentation, but their expression profiles across gestation in pregnancies, which are complicated by gestational diabetes mellitus (GDM), have not been fully established. Investigating a single time point is insufficient, as pregnancy is dynamic, involving several processes, including placenta development, trophoblast proliferation and differentiation and oxygen sensing. Thus, the aim of this study was to compare the temporal expression of serum miRNAs in pregnant women with and without GDM. This is a nested case-control study of longitudinal data obtained from a multicentric European study (the ‘DALI’ study). All women (n = 82) were overweight/obese (BMI ≥ 29 kg/m2) and were normal glucose tolerant (NGT) at baseline (before 20 weeks of gestation). We selected women (n = 41) who were diagnosed with GDM at 24–28 weeks, according to the IADPSG/WHO2013 criteria. They were matched with 41 women who remained NGT in their pregnancy. miRNA (miR-16-5p, -29a-3p, -103-3p, -134-5p, -122-5p, -223-3p, -330-3p and miR-433-3p) were selected based on their suggested importance for placentation, and measurements were performed at baseline and at 24–28 and 35–37 weeks of gestation. Women with GDM presented with overall miRNA levels above those observed for women remaining NGT. In both groups, levels of miR-29a-3p and miR-134-5p increased consistently with progressing gestation. The change over time only differed for miR-29a-3p when comparing women with GDM with those remaining NGT (p = 0.044). Our findings indicate that among overweight/obese women who later develop GDM, miRNA levels are already elevated early in pregnancy and remain above those of women who remain NGT during their pregnancy. Maternal circulating miRNAs may provide further insight into placentation and the cross talk between the maternal and fetal compartments.
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Affiliation(s)
- Anja Elaine Sørensen
- Department of Science and Environment, Roskilde University, 4000 Roskilde, Denmark;
- Correspondence: ; Tel.: +45-4674-3994
| | - Mireille N. M. van Poppel
- Faculty of Environmental and Regional Sciences and Education, Institute of Human Movement Science, Sport and Health, University of Graz, 8010 Graz, Austria;
| | - Gernot Desoye
- Department of Obstetrics and Gynecology, Medical University of Graz, 8036 Graz, Austria;
- Center for Pregnant Women with Diabetes, Department of Obstetrics, Rigshospitalet, 2100 Copenhagen, Denmark;
| | - David Simmons
- Macarthur Clinical School, School of Medicine, Western Sydney University, Campbelltown, NSE 2560, Australia;
| | - Peter Damm
- Center for Pregnant Women with Diabetes, Department of Obstetrics, Rigshospitalet, 2100 Copenhagen, Denmark;
- Department of Clinical Medicine, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Dorte Møller Jensen
- Department of Gynecology and Obstetrics, Odense University Hospital, 5000 Odense, Denmark;
- Department of Clinical Research, Faculty of Health Sciences, University of Southern Denmark, 5000 Odense, Denmark
- Steno Diabetes Center Odense, Department of Gynecology and Obstetrics, Odense University Hospital, 5000 Odense, Denmark
| | - Louise Torp Dalgaard
- Department of Science and Environment, Roskilde University, 4000 Roskilde, Denmark;
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Jiang S, Xu CM, Yao S, Zhang R, Li XZ, Zhang RZ, Xie TY, Xing YQ, Zhang Q, Zhou XJ, Liao L, Dong JJ. Cdc42 upregulation under high glucose induces podocyte apoptosis and impairs β-cell insulin secretion. Front Endocrinol (Lausanne) 2022; 13:905703. [PMID: 36034435 PMCID: PMC9399854 DOI: 10.3389/fendo.2022.905703] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Accepted: 07/15/2022] [Indexed: 01/19/2023] Open
Abstract
OBJECTIVES The progressive impairment of β-cell function results in prolonged deterioration in patients with type 2 diabetes mellitus (T2DM). Interestingly, the finding on pancreatitis secondary to renal injury suggests that potential communication exists between kidney and pancreas. Therefore, we aimed to investigate cell division cycle 42 (Cdc42)-mediated podocyte apoptosis and its effect on insulin secretion in islet β-cells. METHODS Type 2 diabetic nephropathy mouse models were established to identify the expression of Cdc42 in podocytes by immunohistochemistry. An in vitro co-culture of mouse podocyte MPC5 and β-TC6 cells was preliminarily established. Subsequently, podocyte apoptosis induced by high glucose and Cdc42 was detected by TUNEL staining and western blotting. In addition, the JNK pathway was examined to determine the mechanism of apoptosis in MPC5 cells. Finally, insulin secretion and expression in β-TC6 cells as well as malondialdehyde (MDA) and superoxide dismutase (SOD) levels in both cell types were examined after the regulation of Cdc42 in MPC5 cells. RESULTS Cdc42 was highly expressed in the podocytes of diabetic nephropathy mice. Exposure to 25 mM glucose for 48 h induced a significant upregulation of Cdc42, Bax, and cleaved caspase-3 as well as a decreased Bcl-2 expression. In addition, marked apoptosis of MPC5 cells was observed compared to normal glucose treatment. After transfection with Cdc42 plasmid, apoptosis of MPC5 cells was enhanced with an increased expression of p-JNK, whereas inhibition of Cdc42 significantly alleviated podocyte apoptosis accompanied by a downregulation of p-JNK. The glucose-stimulated insulin secretion level of β-TC6 cells decreased after the upregulation of Cdc42 in MPC5 cells. Immunofluorescence staining for insulin showed that co-culture with MPC5 cells carrying the Cdc42 plasmid significantly reduced insulin expression, whereas inhibition of Cdc42 in MPC5 cells alleviated the above-mentioned abnormality of β-TC6 cells. The expression of Cdc42 and p-p38 in β-TC6 cells increased following the upregulation of Cdc42 in MPC5 cells; this was concurrent with augmented MDA levels and decreased SOD activity. The opposite result was observed for Cdc42 knockdown in MPC5 cells. CONCLUSIONS Cdc42 in podocytes plays a crucial role in insulin secretion by β-cells, which may provide a new therapeutic target to prevent the vicious cycle of β-cell dysfunction in T2DM.
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Affiliation(s)
- Shan Jiang
- Department of Endocrinology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Chun-mei Xu
- Department of Endocrinology, Shandong Provincial Hospital affiliated to Shandong University, Jinan, China
| | - Shuai Yao
- Department of Endocrinology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Rui Zhang
- Department of Endocrinology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Xian-zhi Li
- Shandong Key Laboratory of Rheumatic Disease and Translational Medicine, Department of Endocrinology and Metabology, The First Affiliated Hospital of Shandong First Medical University & Shandong Provincial Qian Foshan Hospital, Shandong Institute of Nephrology, Jinan, China
- Department of Endocrinology and Metabology, Shandong Provincial Qianfoshan Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Ru-zhen Zhang
- Shandong Key Laboratory of Rheumatic Disease and Translational Medicine, Department of Endocrinology and Metabology, The First Affiliated Hospital of Shandong First Medical University & Shandong Provincial Qian Foshan Hospital, Shandong Institute of Nephrology, Jinan, China
- Department of Endocrinology and Metabology, Shandong Provincial Qianfoshan Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Tian-yue Xie
- Department of Endocrinology, Shandong Provincial Qianfoshan Hospital, Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Yi-qian Xing
- Department of Endocrinology, Shandong Provincial Qianfoshan Hospital, Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Qian Zhang
- Department of Pharmacology, Key Laboratory of Chemical Biology, School of Pharmaceutical Sciences, Shandong University, Jinan, China
| | - Xiao-jun Zhou
- Shandong Key Laboratory of Rheumatic Disease and Translational Medicine, Department of Endocrinology and Metabology, The First Affiliated Hospital of Shandong First Medical University & Shandong Provincial Qian Foshan Hospital, Shandong Institute of Nephrology, Jinan, China
- Department of Endocrinology and Metabology, Shandong Provincial Qianfoshan Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
- *Correspondence: Lin Liao, ; Jian-jun Dong, ; Xiao-jun Zhou,
| | - Lin Liao
- Department of Endocrinology, Shandong Provincial Hospital affiliated to Shandong University, Jinan, China
- Shandong Key Laboratory of Rheumatic Disease and Translational Medicine, Department of Endocrinology and Metabology, The First Affiliated Hospital of Shandong First Medical University & Shandong Provincial Qian Foshan Hospital, Shandong Institute of Nephrology, Jinan, China
- *Correspondence: Lin Liao, ; Jian-jun Dong, ; Xiao-jun Zhou,
| | - Jian-jun Dong
- Department of Endocrinology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
- *Correspondence: Lin Liao, ; Jian-jun Dong, ; Xiao-jun Zhou,
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10
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Gendaszewska-Darmach E, Garstka MA, Błażewska KM. Targeting Small GTPases and Their Prenylation in Diabetes Mellitus. J Med Chem 2021; 64:9677-9710. [PMID: 34236862 PMCID: PMC8389838 DOI: 10.1021/acs.jmedchem.1c00410] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
![]()
A fundamental role
of pancreatic β-cells to maintain proper
blood glucose level is controlled by the Ras superfamily of small
GTPases that undergo post-translational modifications, including prenylation.
This covalent attachment with either a farnesyl or a geranylgeranyl
group controls their localization, activity, and protein–protein
interactions. Small GTPases are critical in maintaining glucose homeostasis
acting in the pancreas and metabolically active tissues such as skeletal
muscles, liver, or adipocytes. Hyperglycemia-induced upregulation
of small GTPases suggests that inhibition of these pathways deserves
to be considered as a potential therapeutic approach in treating T2D.
This Perspective presents how inhibition of various points in the
mevalonate pathway might affect protein prenylation and functioning
of diabetes-affected tissues and contribute to chronic inflammation
involved in diabetes mellitus (T2D) development. We also demonstrate
the currently available molecular tools to decipher the mechanisms
linking the mevalonate pathway’s enzymes and GTPases with diabetes.
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Affiliation(s)
- Edyta Gendaszewska-Darmach
- Institute of Molecular and Industrial Biotechnology, Faculty of Biotechnology and Food Sciences, Lodz University of Technology, Stefanowskiego Street 4/10, 90-924 Łódź, Poland
| | - Malgorzata A Garstka
- Core Research Laboratory, Department of Endocrinology, Department of Tumor and Immunology, Precision Medical Institute, Western China Science and Technology Innovation Port, School of Medicine, the Second Affiliated Hospital of Xi'an Jiaotong University, DaMingGong, Jian Qiang Road, Wei Yang district, Xi'an 710016, China
| | - Katarzyna M Błażewska
- Institute of Organic Chemistry, Faculty of Chemistry, Lodz University of Technology, Żeromskiego Street 116, 90-924 Łódź, Poland
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11
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Gamage S, Hali M, Kowluru A. CARD9 mediates glucose-stimulated insulin secretion in pancreatic beta cells. Biochem Pharmacol 2021; 192:114670. [PMID: 34233162 DOI: 10.1016/j.bcp.2021.114670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 06/30/2021] [Accepted: 07/01/2021] [Indexed: 11/15/2022]
Abstract
Caspase recruitment domain containing protein 9 (CARD9) plays key regulatory role(s) in innate and adaptive immune responses. Recent evidence implicates CARD9 in the onset of metabolic diseases including insulin resistance. However, potential contributory roles of CARD9 in glucose-stimulated insulin secretion (GSIS) remain unknown. Herein, we report that CARD9 is expressed in human islets, rat islets, mouse islets and clonal INS-1 832/13 cells. Subcellularly, CARD9 is predominantly cytosolic (~75%) in INS-1 832/13 cells. siRNA-mediated depletion of CARD9 expression significantly (~50%) suppressed GSIS in INS-1 832/13 cells. Interestingly, glucose-induced activation of Rac1, a small G-protein, which is a requisite for GSIS to occur, is unaffected in CARD9-si transfected cells, suggesting that CARD9-mediates GSIS in a Rac1-independent fashion. Furthermore, insulin secretion promoted by KCl or mastoparan (a global G protein activator), remained resistant to CARD9 depletion in INS-1 832/13 cells. In addition, pharmacological inhibition (BRD5529) of interaction between CARD9 and TRIM62, its ubiquitin ligase, exerted no significant effects on GSIS. Lastly, depletion of CARD9 prevented glucose-induced p38, not ERK1/2 phosphorylation in beta cells. Based on these observations, we propose that CARD9 might regulate GSIS via a Rac1-independent and p38-dependent signaling module.
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Affiliation(s)
- Suhadinie Gamage
- Biomedical Research Service, John D. Dingell VA Medical Center, and Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, MI 48201, United States
| | - Mirabela Hali
- Biomedical Research Service, John D. Dingell VA Medical Center, and Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, MI 48201, United States
| | - Anjaneyulu Kowluru
- Biomedical Research Service, John D. Dingell VA Medical Center, and Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, MI 48201, United States.
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12
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Karanth SS, Sun S, Bi H, Ye K, Jin S. Angiopoietins stimulate pancreatic islet development from stem cells. Sci Rep 2021; 11:13558. [PMID: 34193893 PMCID: PMC8245566 DOI: 10.1038/s41598-021-92922-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2020] [Accepted: 06/09/2021] [Indexed: 12/19/2022] Open
Abstract
In vitro differentiation of human induced pluripotent stem cells (iPSCs) into functional islets holds immense potential to create an unlimited source of islets for diabetes research and treatment. A continuous challenge in this field is to generate glucose-responsive mature islets. We herein report a previously undiscovered angiopoietin signal for in vitro islet development. We revealed, for the first time, that angiopoietins, including angiopoietin-1 (Ang1) and angiopoietin-2 (Ang2) permit the generation of islets from iPSCs with elevated glucose responsiveness, a hallmark of mature islets. Angiopoietin-stimulated islets exhibited glucose synchronized calcium ion influx in repetitive glucose challenges. Moreover, Ang2 augmented the expression of all islet hormones, including insulin, glucagon, somatostatin, and pancreatic polypeptide; and β cell transcription factors, including NKX6.1, MAFA, UCN3, and PDX1. Furthermore, we showed that the Ang2 stimulated islets were able to regulate insulin exocytosis through actin-filament polymerization and depolymerization upon glucose challenge, presumably through the CDC42-RAC1-gelsolin mediated insulin secretion signaling pathway. We also discovered the formation of endothelium within the islets under Ang2 stimulation. These results strongly suggest that angiopoietin acts as a signaling molecule to endorse in vitro islet development from iPSCs.
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Affiliation(s)
- Soujanya S Karanth
- Department of Biomedical Engineering, Binghamton University, State University of New York (SUNY), Binghamton, NY, 13902, USA
| | - Shuofei Sun
- Department of Biomedical Engineering, Binghamton University, State University of New York (SUNY), Binghamton, NY, 13902, USA
| | - Huanjing Bi
- Department of Biomedical Engineering, Binghamton University, State University of New York (SUNY), Binghamton, NY, 13902, USA
| | - Kaiming Ye
- Department of Biomedical Engineering, Binghamton University, State University of New York (SUNY), Binghamton, NY, 13902, USA.,Center of Biomanufacturing for Regenerative Medicine, Binghamton University, State University of New York (SUNY), Binghamton, NY, 13902, USA
| | - Sha Jin
- Department of Biomedical Engineering, Binghamton University, State University of New York (SUNY), Binghamton, NY, 13902, USA. .,Center of Biomanufacturing for Regenerative Medicine, Binghamton University, State University of New York (SUNY), Binghamton, NY, 13902, USA.
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13
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Duan X, Perveen R, Dandamudi A, Adili R, Johnson J, Funk K, Berryman M, Davis AK, Holinstat M, Zheng Y, Akbar H. Pharmacologic targeting of Cdc42 GTPase by a small molecule Cdc42 activity-specific inhibitor prevents platelet activation and thrombosis. Sci Rep 2021; 11:13170. [PMID: 34162972 PMCID: PMC8222210 DOI: 10.1038/s41598-021-92654-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Accepted: 05/27/2021] [Indexed: 01/14/2023] Open
Abstract
Gene targeting of Cdc42 GTPase has been shown to inhibit platelet activation. In this study, we investigated a hypothesis that inhibition of Cdc42 activity by CASIN, a small molecule Cdc42 Activity-Specific INhibitor, may down regulate platelet activation and thrombus formation. We investigated the effects of CASIN on platelet activation in vitro and thrombosis in vivo. In human platelets, CASIN, but not its inactive analog Pirl7, blocked collagen induced activation of Cdc42 and inhibited phosphorylation of its downstream effector, PAK1/2. Moreover, addition of CASIN to washed human platelets inhibited platelet spreading on immobilized fibrinogen. Treatment of human platelets with CASIN inhibited collagen or thrombin induced: (a) ATP secretion and platelet aggregation; and (b) phosphorylation of Akt, ERK and p38-MAPK. Pre-incubation of platelets with Pirl7, an inactive analog of CASIN, failed to inhibit collagen induced aggregation. Washing of human platelets after incubation with CASIN eliminated its inhibitory effect on collagen induced aggregation. Intraperitoneal administration of CASIN to wild type mice inhibited ex vivo aggregation induced by collagen but did not affect the murine tail bleeding times. CASIN administration, prior to laser-induced injury in murine cremaster muscle arterioles, resulted in formation of smaller and unstable thrombi compared to control mice without CASIN treatment. These data suggest that pharmacologic targeting of Cdc42 by specific and reversible inhibitors may lead to the discovery of novel antithrombotic agents.
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Affiliation(s)
- Xin Duan
- Division of Experimental Hematology and Cancer Biology, Children's Hospital Medical Center, University of Cincinnati, Cincinnati, OH, 45229, USA
| | - Rehana Perveen
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH, 45701, USA
| | - Akhila Dandamudi
- Division of Experimental Hematology and Cancer Biology, Children's Hospital Medical Center, University of Cincinnati, Cincinnati, OH, 45229, USA
| | - Reheman Adili
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI, 48109, USA
| | - James Johnson
- Division of Experimental Hematology and Cancer Biology, Children's Hospital Medical Center, University of Cincinnati, Cincinnati, OH, 45229, USA
| | - Kevin Funk
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH, 45701, USA
| | - Mark Berryman
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH, 45701, USA
| | - Ashley Kuenzi Davis
- Division of Experimental Hematology and Cancer Biology, Children's Hospital Medical Center, University of Cincinnati, Cincinnati, OH, 45229, USA
| | - Michael Holinstat
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI, 48109, USA
| | - Yi Zheng
- Division of Experimental Hematology and Cancer Biology, Children's Hospital Medical Center, University of Cincinnati, Cincinnati, OH, 45229, USA.
| | - Huzoor Akbar
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH, 45701, USA.
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14
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Veluthakal R, Thurmond DC. Emerging Roles of Small GTPases in Islet β-Cell Function. Cells 2021; 10:1503. [PMID: 34203728 PMCID: PMC8232272 DOI: 10.3390/cells10061503] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 06/08/2021] [Accepted: 06/08/2021] [Indexed: 12/16/2022] Open
Abstract
Several small guanosine triphosphatases (GTPases) from the Ras protein superfamily regulate glucose-stimulated insulin secretion in the pancreatic islet β-cell. The Rho family GTPases Cdc42 and Rac1 are primarily involved in relaying key signals in several cellular functions, including vesicle trafficking, plasma membrane homeostasis, and cytoskeletal dynamics. They orchestrate specific changes at each spatiotemporal region within the β-cell by coordinating with signal transducers, guanine nucleotide exchange factors (GEFs), GTPase-activating factors (GAPs), and their effectors. The Arf family of small GTPases is involved in vesicular trafficking (exocytosis and endocytosis) and actin cytoskeletal dynamics. Rab-GTPases regulate pre-exocytotic and late endocytic membrane trafficking events in β-cells. Several additional functions for small GTPases include regulating transcription factor activity and mitochondrial dynamics. Importantly, defects in several of these GTPases have been found associated with type 2 diabetes (T2D) etiology. The purpose of this review is to systematically denote the identities and molecular mechanistic steps in the glucose-stimulated insulin secretion pathway that leads to the normal release of insulin. We will also note newly identified defects in these GTPases and their corresponding regulatory factors (e.g., GDP dissociation inhibitors (GDIs), GEFs, and GAPs) in the pancreatic β-cells, which contribute to the dysregulation of metabolism and the development of T2D.
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Affiliation(s)
- Rajakrishnan Veluthakal
- Department of Molecular and Cellular Endocrinology, Arthur Riggs Diabetes & Metabolism Research Institute, City of Hope Beckman Research Institute, Duarte, CA 91010, USA
| | - Debbie C. Thurmond
- Department of Molecular and Cellular Endocrinology, Arthur Riggs Diabetes & Metabolism Research Institute, City of Hope Beckman Research Institute, Duarte, CA 91010, USA
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15
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Conventional and Unconventional Mechanisms by which Exocytosis Proteins Oversee β-cell Function and Protection. Int J Mol Sci 2021; 22:ijms22041833. [PMID: 33673206 PMCID: PMC7918544 DOI: 10.3390/ijms22041833] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 02/02/2021] [Accepted: 02/08/2021] [Indexed: 02/06/2023] Open
Abstract
Type 2 diabetes (T2D) is one of the prominent causes of morbidity and mortality in the United States and beyond, reaching global pandemic proportions. One hallmark of T2D is dysfunctional glucose-stimulated insulin secretion from the pancreatic β-cell. Insulin is secreted via the recruitment of insulin secretory granules to the plasma membrane, where the soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) and SNARE regulators work together to dock the secretory granules and release insulin into the circulation. SNARE proteins and their regulators include the Syntaxins, SNAPs, Sec1/Munc18, VAMPs, and double C2-domain proteins. Recent studies using genomics, proteomics, and biochemical approaches have linked deficiencies of exocytosis proteins with the onset and progression of T2D. Promising results are also emerging wherein restoration or enhancement of certain exocytosis proteins to β-cells improves whole-body glucose homeostasis, enhances β-cell function, and surprisingly, protection of β-cell mass. Intriguingly, overexpression and knockout studies have revealed novel functions of certain exocytosis proteins, like Syntaxin 4, suggesting that exocytosis proteins can impact a variety of pathways, including inflammatory signaling and aging. In this review, we present the conventional and unconventional functions of β-cell exocytosis proteins in normal physiology and T2D and describe how these insights might improve clinical care for T2D.
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16
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Ahn M, Oh E, McCown EM, Wang X, Veluthakal R, Thurmond DC. A requirement for PAK1 to support mitochondrial function and maintain cellular redox balance via electron transport chain proteins to prevent β-cell apoptosis. Metabolism 2021; 115:154431. [PMID: 33181191 PMCID: PMC8123936 DOI: 10.1016/j.metabol.2020.154431] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 11/04/2020] [Accepted: 11/07/2020] [Indexed: 01/05/2023]
Abstract
OBJECTIVE p21 (Cdc42/Rac1) activated Kinase 1 (PAK1) is a candidate susceptibility factor for type 2 diabetes (T2D). PAK1 is depleted in the islets from T2D donors, compared to control individuals. In addition, whole-body PAK1 knock out (PAK1-KO) in mice worsens the T2D-like effects of high-fat diet. The current study tested the effects of modulating PAK1 levels only in β-cells. MATERIALS/METHODS β-cell-specific inducible PAK1 KO (βPAK1-iKO) mice were generated and used with human β-cells and T2D islets to evaluate β-cell function. RESULTS βPAK1-iKO mice exhibited glucose intolerance and elevated β-cell apoptosis, but without peripheral insulin resistance. β-cells from βPAK-iKO mice also contained fewer mitochondria per cell. At the cellular level, human PAK1-deficient β-cells showed blunted glucose-stimulated insulin secretion and reduced mitochondrial function. Mitochondria from human PAK1-deficient β-cells were deficient in the electron transport chain (ETC) subunits CI, CIII, and CIV; NDUFA12, a CI complex protein, was identified as a novel PAK1 binding partner, and was significantly reduced with PAK1 knockdown. PAK1 knockdown disrupted the NAD+/NADH and NADP+/NADPH ratios, and elevated ROS. An imbalance of the redox state due to mitochondrial dysfunction leads to ER stress in β-cells. PAK1 replenishment in the β-cells of T2D human islets ameliorated levels of ER stress markers. CONCLUSIONS These findings support a protective function for PAK1 in β-cells. The results support a new model whereby the PAK1 in the β-cell plays a required role upstream of mitochondrial function, via maintaining ETC protein levels and averting stress-induced β-cell apoptosis to retain healthy functional β-cell mass.
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Affiliation(s)
- Miwon Ahn
- Department of Molecular and Cellular Endocrinology, Diabetes and Metabolism Research Institute and Beckman Research Institute at the City of Hope, Duarte, CA 91010, United States of America
| | - Eunjin Oh
- Department of Molecular and Cellular Endocrinology, Diabetes and Metabolism Research Institute and Beckman Research Institute at the City of Hope, Duarte, CA 91010, United States of America
| | - Erika M McCown
- Department of Molecular and Cellular Endocrinology, Diabetes and Metabolism Research Institute and Beckman Research Institute at the City of Hope, Duarte, CA 91010, United States of America
| | - Xin Wang
- Faculty of Biology, Medicine and Health, University of Manchester, UK
| | - Rajakrishnan Veluthakal
- Department of Molecular and Cellular Endocrinology, Diabetes and Metabolism Research Institute and Beckman Research Institute at the City of Hope, Duarte, CA 91010, United States of America
| | - Debbie C Thurmond
- Department of Molecular and Cellular Endocrinology, Diabetes and Metabolism Research Institute and Beckman Research Institute at the City of Hope, Duarte, CA 91010, United States of America.
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17
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Liu ZN, Jiang Y, Liu XQ, Yang MM, Chen C, Zhao BH, Huang HF, Luo Q. MiRNAs in Gestational Diabetes Mellitus: Potential Mechanisms and Clinical Applications. J Diabetes Res 2021; 2021:4632745. [PMID: 34869778 PMCID: PMC8635917 DOI: 10.1155/2021/4632745] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2021] [Revised: 06/08/2021] [Accepted: 10/19/2021] [Indexed: 12/12/2022] Open
Abstract
Gestational diabetes mellitus (GDM) is a common pregnancy complication which is normally diagnosed in the second trimester of gestation. With an increasing incidence, GDM poses a significant threat to maternal and offspring health. Therefore, we need a deeper understanding of GDM pathophysiology and novel investigation on the diagnosis and treatment for GDM. MicroRNAs (miRNAs), a class of endogenic small noncoding RNAs with a length of approximately 19-24 nucleotides, have been reported to exert their function in gene expression by binding to proteins or being enclosed in membranous vesicles, such as exosomes. Studies have investigated the roles of miRNAs in the pathophysiological mechanism of GDM and their potential as noninvasive biological candidates for the management of GDM, including diagnosis and treatment. This review is aimed at summarizing the pathophysiological significance of miRNAs in GDM development and their potential function in GDM clinical diagnosis and therapeutic approach. In this review, we summarized an integrated expressional profile and the pathophysiological significance of placental exosomes and associated miRNAs, as well as other plasma miRNAs such as exo-AT. Furthermore, we also discussed the practical application of exosomes in GDM postpartum outcomes and the potential function of several miRNAs as therapeutic target in the GDM pathological pathway, thus providing a novel clinical insight of these biological signatures into GDM therapeutic approach.
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Affiliation(s)
- Zhao-Nan Liu
- Department of Reproductive Genetics, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou 310006, China
| | - Ying Jiang
- Department of Obstetrics, Women's Hospital, School of Medicine, Zhejiang University, China
| | - Xuan-Qi Liu
- Department of Reproductive Genetics, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou 310006, China
| | - Meng-Meng Yang
- Department of Obstetrics, Women's Hospital, School of Medicine, Zhejiang University, China
| | - Cheng Chen
- Department of Obstetrics, Women's Hospital, School of Medicine, Zhejiang University, China
| | - Bai-Hui Zhao
- Department of Obstetrics, Women's Hospital, School of Medicine, Zhejiang University, China
| | - He-Feng Huang
- Department of Reproductive Genetics, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou 310006, China
| | - Qiong Luo
- Department of Obstetrics, Women's Hospital, School of Medicine, Zhejiang University, China
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18
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He XQ, Wang N, Zhao JJ, Wang D, Wang CJ, Xie L, Zheng HY, Shi SZ, He J, Zhou J, Xin HB, Deng KY. Specific deletion of CDC42 in pancreatic β cells attenuates glucose-induced insulin expression and secretion in mice. Mol Cell Endocrinol 2020; 518:111004. [PMID: 32871224 DOI: 10.1016/j.mce.2020.111004] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 08/15/2020] [Accepted: 08/20/2020] [Indexed: 12/22/2022]
Abstract
Insulin is a key hormone for maintaining glucose homeostasis in organisms. In general, deficiency of insulin synthesis and secretion results in type I diabetes, whereas insulin resistance leads to type 2 diabetes. Cell division cycle 42 (CDC42), a member of Rho GTPases family, has been shown as an essential regulator in the second phase of glucose-induced insulin secretion in pancreatic islets β cells in vitro. However, the effect of CDC42 on insulin expression has not been explored. Here we reported that the glucose-induced insulin expression and secretion were significantly inhibited in mice lacking CDC42 gene in pancreatic β cells (Rip-CDC42cKO) in vivo and in vitro. Deletion of CDC42 gene in pancreatic β cells did not affect survival or reproduction in mice. However, the Rip-CDC42cKO mice showed the systemic glucose intolerance and the decrease of glucose-induced insulin secretion without apparent alterations of peripheral tissues insulin sensitivity and the morphology of islets. Furthermore, we demonstrated that deletion of CDC42 gene in pancreatic β cells significantly attenuated the insulin expression through inhibiting the ERK1/2-NeuroD1 signaling pathway. Taken together, our study presents novel evidence that CDC42 is an important modulator in glucose-induced insulin expression as well as insulin secretion in pancreatic β cells.
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Affiliation(s)
- Xiang-Qin He
- The National Engineering Research Center for Bioengineering Drugs and the Technologies, Institute of Translational Medicine, Nanchang University, Nanchang, Jiangxi, China; College of Life Science, Nanchang University, Nanchang, Jiangxi, China
| | - Ning Wang
- The National Engineering Research Center for Bioengineering Drugs and the Technologies, Institute of Translational Medicine, Nanchang University, Nanchang, Jiangxi, China
| | - Juan-Juan Zhao
- The National Engineering Research Center for Bioengineering Drugs and the Technologies, Institute of Translational Medicine, Nanchang University, Nanchang, Jiangxi, China
| | - Dan Wang
- The National Engineering Research Center for Bioengineering Drugs and the Technologies, Institute of Translational Medicine, Nanchang University, Nanchang, Jiangxi, China; Institute for Metabolic and Neuropsychiatric Disorders, Binzhou Medical University, Binzhou, Shandong, China
| | - Cai-Ji Wang
- The National Engineering Research Center for Bioengineering Drugs and the Technologies, Institute of Translational Medicine, Nanchang University, Nanchang, Jiangxi, China
| | - Lin Xie
- The National Engineering Research Center for Bioengineering Drugs and the Technologies, Institute of Translational Medicine, Nanchang University, Nanchang, Jiangxi, China; College of Life Science, Nanchang University, Nanchang, Jiangxi, China
| | - Huai-Yu Zheng
- The National Engineering Research Center for Bioengineering Drugs and the Technologies, Institute of Translational Medicine, Nanchang University, Nanchang, Jiangxi, China
| | - Shui-Zhen Shi
- The National Engineering Research Center for Bioengineering Drugs and the Technologies, Institute of Translational Medicine, Nanchang University, Nanchang, Jiangxi, China
| | - Jing He
- The National Engineering Research Center for Bioengineering Drugs and the Technologies, Institute of Translational Medicine, Nanchang University, Nanchang, Jiangxi, China
| | - Jiliang Zhou
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, GA, 30912, USA
| | - Hong-Bo Xin
- The National Engineering Research Center for Bioengineering Drugs and the Technologies, Institute of Translational Medicine, Nanchang University, Nanchang, Jiangxi, China; College of Life Science, Nanchang University, Nanchang, Jiangxi, China.
| | - Ke-Yu Deng
- The National Engineering Research Center for Bioengineering Drugs and the Technologies, Institute of Translational Medicine, Nanchang University, Nanchang, Jiangxi, China; College of Life Science, Nanchang University, Nanchang, Jiangxi, China.
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19
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The adaptor protein APPL2 controls glucose-stimulated insulin secretion via F-actin remodeling in pancreatic β-cells. Proc Natl Acad Sci U S A 2020; 117:28307-28315. [PMID: 33122440 DOI: 10.1073/pnas.2016997117] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Filamentous actin (F-actin) cytoskeletal remodeling is critical for glucose-stimulated insulin secretion (GSIS) in pancreatic β-cells, and its dysregulation causes type 2 diabetes. The adaptor protein APPL1 promotes first-phase GSIS by up-regulating soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) protein expression. However, whether APPL2 (a close homology of APPL1 with the same domain organization) plays a role in β-cell functions is unknown. Here, we show that APPL2 enhances GSIS by promoting F-actin remodeling via the small GTPase Rac1 in pancreatic β-cells. β-cell specific abrogation of APPL2 impaired GSIS, leading to glucose intolerance in mice. APPL2 deficiency largely abolished glucose-induced first- and second-phase insulin secretion in pancreatic islets. Real-time live-cell imaging and phalloidin staining revealed that APPL2 deficiency abolished glucose-induced F-actin depolymerization in pancreatic islets. Likewise, knockdown of APPL2 expression impaired glucose-stimulated F-actin depolymerization and subsequent insulin secretion in INS-1E cells, which were attributable to the impairment of Ras-related C3 botulinum toxin substrate 1 (Rac1) activation. Treatment with the F-actin depolymerization chemical compounds or overexpression of gelsolin (a F-actin remodeling protein) rescued APPL2 deficiency-induced defective GSIS. In addition, APPL2 interacted with Rac GTPase activating protein 1 (RacGAP1) in a glucose-dependent manner via the bin/amphiphysin/rvs-pleckstrin homology (BAR-PH) domain of APPL2 in INS-1E cells and HEK293 cells. Concomitant knockdown of RacGAP1 expression reverted APPL2 deficiency-induced defective GSIS, F-actin remodeling, and Rac1 activation in INS-1E cells. Our data indicate that APPL2 interacts with RacGAP1 and suppresses its negative action on Rac1 activity and F-actin depolymerization thereby enhancing GSIS in pancreatic β-cells.
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Gene Expression Profiling of Type 2 Diabetes Mellitus by Bioinformatics Analysis. COMPUTATIONAL AND MATHEMATICAL METHODS IN MEDICINE 2020; 2020:9602016. [PMID: 33149760 PMCID: PMC7603564 DOI: 10.1155/2020/9602016] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 07/22/2020] [Accepted: 08/03/2020] [Indexed: 02/07/2023]
Abstract
Objective The aim of this study was to identify the candidate genes in type 2 diabetes mellitus (T2DM) and explore their potential mechanisms. Methods The gene expression profile GSE26168 was downloaded from the Gene Expression Omnibus (GEO) database. The online tool GEO2R was used to obtain differentially expressed genes (DEGs). Gene Ontology (GO) term enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were performed by using Metascape for annotation, visualization, and comprehensive discovery. The protein-protein interaction (PPI) network of DEGs was constructed by using Cytoscape software to find the candidate genes and key pathways. Results A total of 981 DEGs were found in T2DM, including 301 upregulated genes and 680 downregulated genes. GO analyses from Metascape revealed that DEGs were significantly enriched in cell differentiation, cell adhesion, intracellular signal transduction, and regulation of protein kinase activity. KEGG pathway analysis revealed that DEGs were mainly enriched in the cAMP signaling pathway, Rap1 signaling pathway, regulation of lipolysis in adipocytes, PI3K-Akt signaling pathway, MAPK signaling pathway, and so on. On the basis of the PPI network of the DEGs, the following 6 candidate genes were identified: PIK3R1, RAC1, GNG3, GNAI1, CDC42, and ITGB1. Conclusion Our data provide a comprehensive bioinformatics analysis of genes, functions, and pathways, which may be related to the pathogenesis of T2DM.
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Hormones Secretion and Rho GTPases in Neuroendocrine Tumors. Cancers (Basel) 2020; 12:cancers12071859. [PMID: 32664294 PMCID: PMC7408961 DOI: 10.3390/cancers12071859] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 07/03/2020] [Accepted: 07/06/2020] [Indexed: 12/14/2022] Open
Abstract
Neuroendocrine tumors (NETs) belong to a heterogeneous group of neoplasms arising from hormone secreting cells. These tumors are often associated with a dysfunction of their secretory activity. Neuroendocrine secretion occurs through calcium-regulated exocytosis, a process that is tightly controlled by Rho GTPases family members. In this review, we compiled the numerous mutations and modification of expression levels of Rho GTPases or their regulators (Rho guanine nucleotide-exchange factors and Rho GTPase-activating proteins) that have been identified in NETs. We discussed how they might regulate neuroendocrine secretion.
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Miklavc P, Frick M. Actin and Myosin in Non-Neuronal Exocytosis. Cells 2020; 9:cells9061455. [PMID: 32545391 PMCID: PMC7348895 DOI: 10.3390/cells9061455] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 06/03/2020] [Accepted: 06/06/2020] [Indexed: 12/18/2022] Open
Abstract
Cellular secretion depends on exocytosis of secretory vesicles and discharge of vesicle contents. Actin and myosin are essential for pre-fusion and post-fusion stages of exocytosis. Secretory vesicles depend on actin for transport to and attachment at the cell cortex during the pre-fusion phase. Actin coats on fused vesicles contribute to stabilization of large vesicles, active vesicle contraction and/or retrieval of excess membrane during the post-fusion phase. Myosin molecular motors complement the role of actin. Myosin V is required for vesicle trafficking and attachment to cortical actin. Myosin I and II members engage in local remodeling of cortical actin to allow vesicles to get access to the plasma membrane for membrane fusion. Myosins stabilize open fusion pores and contribute to anchoring and contraction of actin coats to facilitate vesicle content release. Actin and myosin function in secretion is regulated by a plethora of interacting regulatory lipids and proteins. Some of these processes have been first described in non-neuronal cells and reflect adaptations to exocytosis of large secretory vesicles and/or secretion of bulky vesicle cargoes. Here we collate the current knowledge and highlight the role of actomyosin during distinct phases of exocytosis in an attempt to identify unifying molecular mechanisms in non-neuronal secretory cells.
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Affiliation(s)
- Pika Miklavc
- School of Science, Engineering & Environment, University of Salford, Manchester M5 4WT, UK
- Correspondence: (P.M.); (M.F.); Tel.: +44-0161-295-3395 (P.M.); +49-731-500-23115 (M.F.); Fax: +49-731-500-23242 (M.F.)
| | - Manfred Frick
- Institute of General Physiology, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany
- Correspondence: (P.M.); (M.F.); Tel.: +44-0161-295-3395 (P.M.); +49-731-500-23115 (M.F.); Fax: +49-731-500-23242 (M.F.)
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Non-Coding RNA: Role in Gestational Diabetes Pathophysiology and Complications. Int J Mol Sci 2020; 21:ijms21114020. [PMID: 32512799 PMCID: PMC7312670 DOI: 10.3390/ijms21114020] [Citation(s) in RCA: 67] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 05/30/2020] [Accepted: 06/02/2020] [Indexed: 12/12/2022] Open
Abstract
Gestational Diabetes Mellitus (GDM) is defined as glucose intolerance that develops in the second or third trimester of pregnancy. GDM can lead to short-term and long-term complications both in the mother and in the offspring. Diagnosing and treating this condition is therefore of great importance to avoid poor pregnancy outcomes. There is increasing interest in finding new markers with potential diagnostic, prognostic and therapeutic utility in GDM. Non-coding RNAs (ncRNAs), including microRNAs, long non-coding RNAs and circular RNAs, are critically involved in metabolic processes and their dysregulated expression has been reported in several pathological contexts. The aberrant expression of several circulating or placenta-related ncRNAs has been linked to insulin resistance and β-cell dysfunction, the key pathophysiological features of GDM. Furthermore, significant associations between altered ncRNA profiles and GDM-related complications, such as macrosomia or trophoblast dysfunction, have been observed. Remarkably, the deregulation of ncRNAs, which might be linked to a detrimental intrauterine environment, can lead to changes in the expression of target genes in the offspring, possibly contributing to the development of long-term GDM-related complications, such as metabolic and cardiovascular diseases. In this review, all the recent findings on ncRNAs and GDM are summarized, particularly focusing on the molecular aspects and the pathophysiological implications of this complex relationship.
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Abstract
The environment within the Endoplasmic Reticulum (ER) influences Insulin biogenesis. In particular, ER stress may contribute to the development of Type 2 Diabetes (T2D) and Cystic Fibrosis Related Diabetes (CFRD), where evidence of impaired Insulin processing, including elevated secreted Proinsulin/Insulin ratios, are observed. Our group has established the role of a novel ER chaperone ERp29 (ER protein of 29 kDa) in the biogenesis of the Epithelial Sodium Channel, ENaC. The biogenesis of Insulin and ENaC share may key features, including their potential association with COP II machinery, their cleavage into a more active form in the Golgi or later compartments, and their ability to bypass such cleavage and remain in a less active form. Given these similarities we hypothesized that ERp29 is a critical factor in promoting the efficient conversion of Proinsulin to Insulin. Here, we confirmed that Proinsulin associates with the COP II vesicle cargo recognition component, Sec24D. When Sec24D expression was decreased, we observed a corresponding decrease in whole cell Proinsulin levels. In addition, we found that Sec24D associates with ERp29 in co-precipitation experiments and that ERp29 associates with Proinsulin in co-precipitation experiments. When ERp29 was overexpressed, a corresponding increase in whole cell Proinsulin levels was observed, while depletion of ERp29 decreased whole cell Proinsulin levels. Together, these data suggest a potential role for ERp29 in regulating Insulin biosynthesis, perhaps in promoting the exit of Proinsulin from the ER via Sec24D/COPII vesicles.
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25
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Lawlor N, Márquez EJ, Orchard P, Narisu N, Shamim MS, Thibodeau A, Varshney A, Kursawe R, Erdos MR, Kanke M, Gu H, Pak E, Dutra A, Russell S, Li X, Piecuch E, Luo O, Chines PS, Fuchbserger C, Sethupathy P, Aiden AP, Ruan Y, Aiden EL, Collins FS, Ucar D, Parker SCJ, Stitzel ML. Multiomic Profiling Identifies cis-Regulatory Networks Underlying Human Pancreatic β Cell Identity and Function. Cell Rep 2020; 26:788-801.e6. [PMID: 30650367 PMCID: PMC6389269 DOI: 10.1016/j.celrep.2018.12.083] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Revised: 10/26/2018] [Accepted: 12/18/2018] [Indexed: 12/22/2022] Open
Abstract
EndoC-βH1 is emerging as a critical human β cell model to study the genetic and environmental etiologies of β cell (dys)function and diabetes. Comprehensive knowledge of its molecular landscape is lacking, yet required, for effective use of this model. Here, we report chromosomal (spectral karyotyping), genetic (genotyping), epigenomic (ChIP-seq and ATAC-seq), chromatin interaction (Hi-C and Pol2 ChIA-PET), and transcriptomic (RNA-seq and miRNA-seq) maps of EndoC-βH1. Analyses of these maps define known (e.g., PDX1 and ISL1) and putative (e.g., PCSK1 and mir-375) β cell-specific transcriptional cis-regulatory networks and identify allelic effects on cis-regulatory element use. Importantly, comparison with maps generated in primary human islets and/or β cells indicates preservation of chromatin looping but also highlights chromosomal aberrations and fetal genomic signatures in EndoC-βH1. Together, these maps, and a web application we created for their exploration, provide important tools for the design of experiments to probe and manipulate the genetic programs governing β cell identity and (dys)function in diabetes. EndoC-βH1 is becoming an important cellular model to study genes and pathways governing human β cell identity and function, but its (epi)genomic similarity to primary human islets is unknown. Lawlor et al. complete and compare extensive EndoC and primary human islet multiomic maps to identify shared and distinct genomic circuitry.
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Affiliation(s)
- Nathan Lawlor
- The Jackson Laboratory for Genomic Medicine, Farmington, CT 06032, USA
| | - Eladio J Márquez
- The Jackson Laboratory for Genomic Medicine, Farmington, CT 06032, USA
| | - Peter Orchard
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI 48109, USA
| | - Narisu Narisu
- National Human Genome Research Institute, NIH, Bethesda, MD 20892, USA
| | - Muhammad Saad Shamim
- Center for Genome Architecture, Baylor College of Medicine, Houston, TX 77030, USA; Medical Scientist Training Program, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Department of Computer Science, Department of Computational and Applied Mathematics, Rice University, Houston, TX 77030, USA; Department of Bioengineering, Rice University, Houston, TX 77030, USA
| | - Asa Thibodeau
- The Jackson Laboratory for Genomic Medicine, Farmington, CT 06032, USA
| | - Arushi Varshney
- Department of Human Genetics, University of Michigan, Ann Arbor, MI 48109, USA
| | - Romy Kursawe
- The Jackson Laboratory for Genomic Medicine, Farmington, CT 06032, USA
| | - Michael R Erdos
- National Human Genome Research Institute, NIH, Bethesda, MD 20892, USA
| | - Matt Kanke
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
| | - Huiya Gu
- Center for Genome Architecture, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Evgenia Pak
- National Human Genome Research Institute, NIH, Bethesda, MD 20892, USA
| | - Amalia Dutra
- National Human Genome Research Institute, NIH, Bethesda, MD 20892, USA
| | - Sheikh Russell
- Center for Genome Architecture, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Department of Computer Science, Department of Computational and Applied Mathematics, Rice University, Houston, TX 77030, USA
| | - Xingwang Li
- The Jackson Laboratory for Genomic Medicine, Farmington, CT 06032, USA
| | - Emaly Piecuch
- The Jackson Laboratory for Genomic Medicine, Farmington, CT 06032, USA; Department of Genetics and Genome Sciences, University of Connecticut, Farmington, CT 06032, USA
| | - Oscar Luo
- The Jackson Laboratory for Genomic Medicine, Farmington, CT 06032, USA
| | - Peter S Chines
- National Human Genome Research Institute, NIH, Bethesda, MD 20892, USA
| | - Christian Fuchbserger
- Department of Biostatistics and Center for Statistical Genetics, School of Public Health, University of Michigan, Ann Arbor, MI 48109, USA
| | | | - Praveen Sethupathy
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
| | - Aviva Presser Aiden
- Center for Genome Architecture, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Department of Bioengineering, Rice University, Houston, TX 77030, USA; Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Yijun Ruan
- The Jackson Laboratory for Genomic Medicine, Farmington, CT 06032, USA
| | - Erez Lieberman Aiden
- Center for Genome Architecture, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Department of Computer Science, Department of Computational and Applied Mathematics, Rice University, Houston, TX 77030, USA; Center for Theoretical Biological Physics, Rice University, Houston, TX 77005, USA; Broad Institute of Harvard and Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Francis S Collins
- National Human Genome Research Institute, NIH, Bethesda, MD 20892, USA
| | - Duygu Ucar
- The Jackson Laboratory for Genomic Medicine, Farmington, CT 06032, USA; Department of Genetics and Genome Sciences, University of Connecticut, Farmington, CT 06032, USA; Institute for Systems Genomics, University of Connecticut, Farmington, CT 06032, USA
| | - Stephen C J Parker
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI 48109, USA; Department of Human Genetics, University of Michigan, Ann Arbor, MI 48109, USA
| | - Michael L Stitzel
- The Jackson Laboratory for Genomic Medicine, Farmington, CT 06032, USA; Department of Genetics and Genome Sciences, University of Connecticut, Farmington, CT 06032, USA; Institute for Systems Genomics, University of Connecticut, Farmington, CT 06032, USA.
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Ma W, Chang J, Tong J, Ho U, Yau B, Kebede MA, Thorn P. Arp2/3 nucleates F-actin coating of fusing insulin granules in pancreatic β cells to control insulin secretion. J Cell Sci 2020; 133:jcs236794. [PMID: 32079655 DOI: 10.1242/jcs.236794] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Accepted: 02/05/2020] [Indexed: 01/11/2023] Open
Abstract
F-actin dynamics are known to control insulin secretion, but the point of intersection with the stimulus-secretion cascade is unknown. Here, using multiphoton imaging of β cells isolated from Lifeact-GFP transgenic mice, we show that glucose stimulation does not cause global changes in subcortical F-actin. Instead, we observe spatially discrete and transient F-actin changes around each fusing granule. This F-actin remodelling is dependent on actin nucleation and is observed for granule fusion induced by either glucose or high potassium stimulation. Using GFP-labelled proteins, we identify local enrichment of Arp3, dynamin 2 and clathrin, all occurring after granule fusion, suggesting early recruitment of an endocytic complex to the fusing granules. Block of Arp2/3 activity with drugs or shRNA inhibits F-actin coating, traps granules at the cell membrane and reduces insulin secretion. Block of formin-mediated actin nucleation also blocks F-actin coating, but has no effect on insulin secretion. We conclude that local Arp2/3-dependent actin nucleation at the sites of granule fusion plays an important role in post-fusion granule dynamics and in the regulation of insulin secretion.
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Affiliation(s)
- Wei Ma
- Discipline of Physiology, School of Medical Sciences, Charles Perkins Centre, University of Sydney, Camperdown 2006, Australia
| | - Jenny Chang
- School of Biomedical Sciences, University of Queensland, St Lucia 4072, Australia
| | - Jason Tong
- Discipline of Physiology, School of Medical Sciences, Charles Perkins Centre, University of Sydney, Camperdown 2006, Australia
| | - Uda Ho
- School of Biomedical Sciences, University of Queensland, St Lucia 4072, Australia
| | - Belinda Yau
- Discipline of Physiology, School of Medical Sciences, Charles Perkins Centre, University of Sydney, Camperdown 2006, Australia
| | - Melkam A Kebede
- Discipline of Physiology, School of Medical Sciences, Charles Perkins Centre, University of Sydney, Camperdown 2006, Australia
| | - Peter Thorn
- Discipline of Physiology, School of Medical Sciences, Charles Perkins Centre, University of Sydney, Camperdown 2006, Australia
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27
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Abstract
Glucose-induced (physiological) insulin secretion from the islet β-cell involves interplay between cationic (i.e., changes in intracellular calcium) and metabolic (i.e., generation of hydrophobic and hydrophilic second messengers) events. A large body of evidence affirms support for novel regulation, by G proteins, of specific intracellular signaling events, including actin cytoskeletal remodeling, transport of insulin-containing granules to the plasma membrane for fusion, and secretion of insulin into the circulation. This article highlights the following aspects of GPCR-G protein biology of the islet. First, it overviews our current understanding of the identity of a wide variety of G protein regulators and their modulatory roles in GPCR-G protein-effector coupling, which is requisite for optimal β-cell function under physiological conditions. Second, it describes evidence in support of novel, noncanonical, GPCR-independent mechanisms of activation of G proteins in the islet. Third, it highlights the evidence indicating that abnormalities in G protein function lead to islet β-cell dysregulation and demise under the duress of metabolic stress and diabetes. Fourth, it summarizes observations of potential beneficial effects of GPCR agonists in preventing/halting metabolic defects in the islet β-cell under various pathological conditions (e.g., metabolic stress and inflammation). Lastly, it identifies knowledge gaps and potential avenues for future research in this evolving field of translational islet biology. Published 2020. Compr Physiol 10:453-490, 2020.
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Affiliation(s)
- Anjaneyulu Kowluru
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Center for Translational Research in Diabetes, Biomedical Research Service, John D. Dingell VA Medical Center, Wayne State University, Detroit, Michigan, USA
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28
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Kimura T, Yamaoka M, Terabayashi T, Kaibuchi K, Ishikawa T, Ishizaki T. GDP-Bound Rab27a Dissociates from the Endocytic Machinery in a Phosphorylation-Dependent Manner after Insulin Secretion. Biol Pharm Bull 2020; 42:1532-1537. [PMID: 31474712 DOI: 10.1248/bpb.b19-00242] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Glucose-stimulated insulin secretion is controlled by both exocytosis and endocytosis in pancreatic β-cells. Although endocytosis is a fundamental step to maintain cellular responses to the secretagogue, the molecular mechanism of endocytosis remains poorly defined. We have previously shown that in response to high concentrations of glucose, guanosine 5'-diphosphate (GDP)-bound Rab27a is recruited to the plasma membrane where IQ motif-containing guanosine 5'-triphosphatase (GTPase)-activating protein 1 (IQGAP1) is expressed, and that complex formation promotes endocytosis of secretory membranes after insulin secretion. In the present study, the regulatory mechanisms of dissociation of the complex were investigated. Phosphorylation of IQGAP1 on serine (Ser)-1443, a site recognized by protein kinase Cε (PKCε), inhibited the interaction of GDP-bound Rab27a with IQGAP1 in a Cdc42-independent manner. Glucose stimulation caused a translocation of PKCε from the cytosol to the plasma membrane. In addition, glucose-induced endocytosis was inhibited by the knockdown of IQGAP1 with small interfering RNA (siRNA). However, the expression of the non-phosphorylatable or phosphomimetic form of IQGAP1 could not rescue the inhibition, suggesting that a phosphorylation-dephosphorylation cycle of IQGAP1 is required for endocytosis. These results suggest that IQGAP1 phosphorylated by PKCε promotes the dissociation of the IQGAP1-GDP-bound Rab27a complex in pancreatic β-cells, thereby regulating endocytosis of secretory membranes following insulin secretion.
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Affiliation(s)
- Toshihide Kimura
- Department of Pharmacology, School of Pharmaceutical Sciences, University of Shizuoka.,Department of Pharmacology, Oita University Faculty of Medicine
| | - Mami Yamaoka
- Department of Pharmacology, Oita University Faculty of Medicine
| | | | - Kozo Kaibuchi
- Department of Cell Pharmacology, Graduate School of Medicine, Nagoya University.,Institute for Comprehensive Medical Science, Fujita Health University
| | - Tomohisa Ishikawa
- Department of Pharmacology, School of Pharmaceutical Sciences, University of Shizuoka
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29
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Pfeiffer S, Sánchez-Lechuga B, Donovan P, Halang L, Prehn JHM, Campos-Caro A, Byrne MM, López-Tinoco C. Circulating miR-330-3p in Late Pregnancy is Associated with Pregnancy Outcomes Among Lean Women with GDM. Sci Rep 2020; 10:908. [PMID: 31969632 PMCID: PMC6976655 DOI: 10.1038/s41598-020-57838-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Accepted: 12/30/2019] [Indexed: 02/07/2023] Open
Abstract
Gestational Diabetes Mellitus (GDM) is characterised by insulin resistance accompanied by reduced beta-cell compensation to increased insulin demand, typically observed in the second and third trimester and associated with adverse pregnancy outcomes. There is a need for a biomarker that can accurately monitor status and predict outcome in GDM, reducing foetal-maternal morbidity and mortality risks. To this end, circulating microRNAs (miRNAs) present themselves as promising candidates, stably expressed in serum and known to play crucial roles in regulation of glucose metabolism. We analysed circulating miRNA profiles in a cohort of GDM patients (n = 31) and nondiabetic controls (n = 29) during the third trimester for miRNA associated with insulin-secretory defects and glucose homeostasis. We identified miR-330-3p as being significantly upregulated in lean women with GDM compared to nondiabetic controls. Furthermore, increased levels of miR-330-3p were associated with better response to treatment (diet vs. insulin), with lower levels associated with exogenous insulin requirement. We observed miR-330-3p to be significantly related to the percentage of caesarean deliveries, with miR-330-3p expression significantly higher in spontaneously delivered GDM patients. We report this strong novel association of circulating miR-330-3p with risk of primary caesarean delivery as a pregnancy outcome linked with poor maternal glycaemic control, strengthening the growing body of evidence for roles of diabetes-associated miRNAs in glucose homeostasis and adaptation to the complex changes related to pregnancy.
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Affiliation(s)
- Shona Pfeiffer
- Centre for Systems Medicine, Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, 123 St. Stephen's Green, Dublin, 2, Ireland
| | - Begoña Sánchez-Lechuga
- Servicio de Endocrinología y Nutrición, Hospital Universitario Puerta del Mar, Cádiz, Spain
| | - Paul Donovan
- Centre for Systems Medicine, Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, 123 St. Stephen's Green, Dublin, 2, Ireland
| | - Luise Halang
- Centre for Systems Medicine, Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, 123 St. Stephen's Green, Dublin, 2, Ireland
| | - Jochen H M Prehn
- Centre for Systems Medicine, Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, 123 St. Stephen's Green, Dublin, 2, Ireland
| | - Antonio Campos-Caro
- Servicio de Endocrinología y Nutrición, Hospital Universitario Puerta del Mar, Cádiz, Spain
| | - Maria M Byrne
- Centre for Systems Medicine, Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, 123 St. Stephen's Green, Dublin, 2, Ireland.,Department of Endocrinology, Mater Misericordiae University Hospital, Eccles Street, Dublin, 7, Ireland
| | - Cristina López-Tinoco
- Servicio de Endocrinología y Nutrición, Hospital Universitario Puerta del Mar, Cádiz, Spain.
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30
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Tomas A, Jones B, Leech C. New Insights into Beta-Cell GLP-1 Receptor and cAMP Signaling. J Mol Biol 2019; 432:1347-1366. [PMID: 31446075 DOI: 10.1016/j.jmb.2019.08.009] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2019] [Revised: 08/06/2019] [Accepted: 08/13/2019] [Indexed: 12/14/2022]
Abstract
Harnessing the translational potential of the GLP-1/GLP-1R system in pancreatic beta cells has led to the development of established GLP-1R-based therapies for the long-term preservation of beta cell function. In this review, we discuss recent advances in the current research on the GLP-1/GLP-1R system in beta cells, including the regulation of signaling by endocytic trafficking as well as the application of concepts such as signal bias, allosteric modulation, dual agonism, polymorphic receptor variants, spatial compartmentalization of cAMP signaling and new downstream signaling targets involved in the control of beta cell function.
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Affiliation(s)
- Alejandra Tomas
- Section of Cell Biology and Functional Genomics, Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Imperial College London, London, W12 0NN, UK.
| | - Ben Jones
- Section of Investigative Medicine, Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Imperial College London, London, W12 0NN, UK
| | - Colin Leech
- Department of Surgery, State University of New York, Upstate Medical University, Syracuse, NY, 13210, USA
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31
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Gilleron J, Gerdes JM, Zeigerer A. Metabolic regulation through the endosomal system. Traffic 2019; 20:552-570. [PMID: 31177593 PMCID: PMC6771607 DOI: 10.1111/tra.12670] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 06/05/2019] [Accepted: 06/05/2019] [Indexed: 12/13/2022]
Abstract
The endosomal system plays an essential role in cell homeostasis by controlling cellular signaling, nutrient sensing, cell polarity and cell migration. However, its place in the regulation of tissue, organ and whole body physiology is less well understood. Recent studies have revealed an important role for the endosomal system in regulating glucose and lipid homeostasis, with implications for metabolic disorders such as type 2 diabetes, hypercholesterolemia and non-alcoholic fatty liver disease. By taking insights from in vitro studies of endocytosis and exploring their effects on metabolism, we can begin to connect the fields of endosomal transport and metabolic homeostasis. In this review, we explore current understanding of how the endosomal system influences the systemic regulation of glucose and lipid metabolism in mice and humans. We highlight exciting new insights that help translate findings from single cells to a wider physiological level and open up new directions for endosomal research.
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Affiliation(s)
- Jerome Gilleron
- Université Côte d'Azur, Institut National de la Santé et de la Recherche Médicale (INSERM), Mediterranean Center of Molecular Medicine (C3M)NiceFrance
| | - Jantje M. Gerdes
- Institute for Diabetes and RegenerationHelmholtz Center MunichNeuherbergGermany
- German Center for Diabetes Research (DZD)NeuherbergGermany
| | - Anja Zeigerer
- German Center for Diabetes Research (DZD)NeuherbergGermany
- Institute for Diabetes and CancerHelmholtz Center MunichNeuherbergGermany
- Joint Heidelberg‐IDC Translational Diabetes ProgramHeidelberg University HospitalHeidelbergGermany
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Joseph GA, Hung M, Goel AJ, Hong M, Rieder MK, Beckmann ND, Serasinghe MN, Chipuk JE, Devarakonda PM, Goldhamer DJ, Aldana-Hernandez P, Curtis J, Jacobs RL, Krauss RS. Late-onset megaconial myopathy in mice lacking group I Paks. Skelet Muscle 2019; 9:5. [PMID: 30791960 PMCID: PMC6383276 DOI: 10.1186/s13395-019-0191-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 02/12/2019] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Group I Paks are serine/threonine kinases that function as major effectors of the small GTPases Rac1 and Cdc42, and they regulate cytoskeletal dynamics, cell polarity, and transcription. We previously demonstrated that Pak1 and Pak2 function redundantly to promote skeletal myoblast differentiation during postnatal development and regeneration in mice. However, the roles of Pak1 and Pak2 in adult muscle homeostasis are unknown. Choline kinase β (Chk β) is important for adult muscle homeostasis, as autosomal recessive mutations in CHKβ are associated with two human muscle diseases, megaconial congenital muscular dystrophy and proximal myopathy with focal depletion of mitochondria. METHODS We analyzed mice conditionally lacking Pak1 and Pak2 in the skeletal muscle lineage (double knockout (dKO) mice) over 1 year of age. Muscle integrity in dKO mice was assessed with histological stains, immunofluorescence, electron microscopy, and western blotting. Assays for mitochondrial respiratory complex function were performed, as was mass spectrometric quantification of products of choline kinase. Mice and cultured myoblasts deficient for choline kinase β (Chk β) were analyzed for Pak1/2 phosphorylation. RESULTS dKO mice developed an age-related myopathy. By 10 months of age, dKO mouse muscles displayed centrally-nucleated myofibers, fibrosis, and signs of degeneration. Disease severity occurred in a rostrocaudal gradient, hindlimbs more strongly affected than forelimbs. A distinctive feature of this myopathy was elongated and branched intermyofibrillar (megaconial) mitochondria, accompanied by focal mitochondrial depletion in the central region of the fiber. dKO muscles showed reduced mitochondrial respiratory complex I and II activity. These phenotypes resemble those of rmd mice, which lack Chkβ and are a model for human diseases associated with CHKβ deficiency. Pak1/2 and Chkβ activities were not interdependent in mouse skeletal muscle, suggesting a more complex relationship in regulation of mitochondria and muscle homeostasis. CONCLUSIONS Conditional loss of Pak1 and Pak2 in mice resulted in an age-dependent myopathy with similarity to mice and humans with CHKβ deficiency. Protein kinases are major regulators of most biological processes but few have been implicated in muscle maintenance or disease. Pak1/Pak2 dKO mice offer new insights into these processes.
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Affiliation(s)
- Giselle A Joseph
- Department of Cell, Developmental, and Regenerative Biology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1020, New York, NY, 10029, USA.,Graduate School of Biological Sciences, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1020, New York, NY, 10029, USA.,Present address: Novartis Institutes for BioMedical Research, 181 Massachusetts Ave, Cambridge, MA, 02139, USA
| | - Margaret Hung
- Department of Cell, Developmental, and Regenerative Biology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1020, New York, NY, 10029, USA.,Graduate School of Biological Sciences, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1020, New York, NY, 10029, USA
| | - Aviva J Goel
- Department of Cell, Developmental, and Regenerative Biology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1020, New York, NY, 10029, USA.,Graduate School of Biological Sciences, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1020, New York, NY, 10029, USA
| | - Mingi Hong
- Department of Cell, Developmental, and Regenerative Biology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1020, New York, NY, 10029, USA
| | - Marysia-Kolbe Rieder
- Department of Cell, Developmental, and Regenerative Biology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1020, New York, NY, 10029, USA
| | - Noam D Beckmann
- Graduate School of Biological Sciences, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1020, New York, NY, 10029, USA.,Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1020, New York, NY, 10029, USA
| | - Madhavika N Serasinghe
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Jerry E Chipuk
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Parvathi M Devarakonda
- Department of Molecular & Cell Biology, University of Connecticut, Storrs, CT, 06269, USA
| | - David J Goldhamer
- Department of Molecular & Cell Biology, University of Connecticut, Storrs, CT, 06269, USA
| | - Paulina Aldana-Hernandez
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, T6G 2E1, Canada
| | - Jonathan Curtis
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, T6G 2E1, Canada
| | - René L Jacobs
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, T6G 2E1, Canada
| | - Robert S Krauss
- Department of Cell, Developmental, and Regenerative Biology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1020, New York, NY, 10029, USA. .,Graduate School of Biological Sciences, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1020, New York, NY, 10029, USA.
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Huang QY, Lai XN, Qian XL, Lv LC, Li J, Duan J, Xiao XH, Xiong LX. Cdc42: A Novel Regulator of Insulin Secretion and Diabetes-Associated Diseases. Int J Mol Sci 2019; 20:ijms20010179. [PMID: 30621321 PMCID: PMC6337499 DOI: 10.3390/ijms20010179] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2018] [Revised: 12/26/2018] [Accepted: 12/29/2018] [Indexed: 02/07/2023] Open
Abstract
Cdc42, a member of the Rho GTPases family, is involved in the regulation of several cellular functions including cell cycle progression, survival, transcription, actin cytoskeleton organization and membrane trafficking. Diabetes is a chronic and metabolic disease, characterized as glycometabolism disorder induced by insulin deficiency related to β cell dysfunction and peripheral insulin resistance (IR). Diabetes could cause many complications including diabetic nephropathy (DN), diabetic retinopathy and diabetic foot. Furthermore, hyperglycemia can promote tumor progression and increase the risk of malignant cancers. In this review, we summarized the regulation of Cdc42 in insulin secretion and diabetes-associated diseases. Organized researches indicate that Cdc42 is a crucial member during the progression of diabetes, and Cdc42 not only participates in the process of insulin synthesis but also regulates the insulin granule mobilization and cell membrane exocytosis via activating a series of downstream factors. Besides, several studies have demonstrated Cdc42 as participating in the pathogenesis of IR and DN and even contributing to promote cancer cell proliferation, survival, invasion, migration, and metastasis under hyperglycemia. Through the current review, we hope to cast light on the mechanism of Cdc42 in diabetes and associated diseases and provide new ideas for clinical diagnosis, treatment, and prevention.
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Affiliation(s)
- Qi-Yuan Huang
- Department of Pathophysiology, Medical College, Nanchang University, Jiangxi Province Key Laboratory of Tumor Pathogenesis and Molecular Pathology, 461 Bayi Road, Nanchang 330006, China.
| | - Xing-Ning Lai
- Department of Pathophysiology, Medical College, Nanchang University, Jiangxi Province Key Laboratory of Tumor Pathogenesis and Molecular Pathology, 461 Bayi Road, Nanchang 330006, China.
| | - Xian-Ling Qian
- Department of Pathophysiology, Medical College, Nanchang University, Jiangxi Province Key Laboratory of Tumor Pathogenesis and Molecular Pathology, 461 Bayi Road, Nanchang 330006, China.
| | - Lin-Chen Lv
- Department of Pathophysiology, Medical College, Nanchang University, Jiangxi Province Key Laboratory of Tumor Pathogenesis and Molecular Pathology, 461 Bayi Road, Nanchang 330006, China.
| | - Jun Li
- Department of Pathophysiology, Medical College, Nanchang University, Jiangxi Province Key Laboratory of Tumor Pathogenesis and Molecular Pathology, 461 Bayi Road, Nanchang 330006, China.
| | - Jing Duan
- Department of Pathophysiology, Medical College, Nanchang University, Jiangxi Province Key Laboratory of Tumor Pathogenesis and Molecular Pathology, 461 Bayi Road, Nanchang 330006, China.
| | - Xing-Hua Xiao
- Department of Pathophysiology, Medical College, Nanchang University, Jiangxi Province Key Laboratory of Tumor Pathogenesis and Molecular Pathology, 461 Bayi Road, Nanchang 330006, China.
| | - Li-Xia Xiong
- Department of Pathophysiology, Medical College, Nanchang University, Jiangxi Province Key Laboratory of Tumor Pathogenesis and Molecular Pathology, 461 Bayi Road, Nanchang 330006, China.
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Duan J, Qian XL, Li J, Xiao XH, Lu XT, Lv LC, Huang QY, Ding W, Zhang HY, Xiong LX. miR-29a Negatively Affects Glucose-Stimulated Insulin Secretion and MIN6 Cell Proliferation via Cdc42/ β-Catenin Signaling. Int J Endocrinol 2019; 2019:5219782. [PMID: 31662747 PMCID: PMC6735210 DOI: 10.1155/2019/5219782] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Accepted: 06/13/2019] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Diabetes is a progressive metabolic disease characterized by hyperglycemia. Functional impairment of islet β cells can occur to varying degrees. This impairment can initially be compensated for by proliferation and metabolic changes of β cells. Cell division control protein 42 (Cdc42) and the microRNA (miRNA) miR-29 have important roles in β-cell proliferation and glucose-stimulated insulin secretion (GSIS), which we further explored using the mouse insulinoma cell line MIN6. METHODS Upregulation and downregulation of miR-29a and Cdc42 were accomplished using transient transfection. miR-29a and Cdc42 expression was detected by real-time PCR and western blotting. MIN6 proliferation was detected using a cell counting kit assay. GSIS under high-glucose (20.0 mM) or basal-glucose (5.0 mM) stimulation was detected by enzyme-linked immunosorbent assay. The miR-29a binding site in the Cdc42 mRNA 3'-untranslated region (UTR) was determined using bioinformatics and luciferase reporter assays. RESULTS miR-29a overexpression inhibited proliferation (P < 0.01) and GSIS under high-glucose stimulation (P < 0.01). Cdc42 overexpression promoted proliferation (P < 0.05) and GSIS under high-glucose stimulation (P < 0.05). miR-29a overexpression decreased Cdc42 expression (P < 0.01), whereas miR-29a downregulation increased Cdc42 expression (P < 0.01). The results showed that the Cdc42 mRNA 3'-UTR is a direct target of miR-29a in vitro. Additionally, Cdc42 reversed miR-29a-mediated inhibition of proliferation and GSIS (P < 0.01). Furthermore, miR-29a inhibited β-catenin expression (P < 0.01), whereas Cdc42 promoted β-catenin expression (P < 0.01). CONCLUSION By negatively regulating Cdc42 and the downstream molecule β-catenin, miR-29a inhibits MIN6 proliferation and insulin secretion.
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Affiliation(s)
- Jing Duan
- Department of Pathophysiology, Medical College, Nanchang University, 461 Bayi Road, Nanchang 330006, China
| | - Xian-Ling Qian
- Department of Pathophysiology, Medical College, Nanchang University, 461 Bayi Road, Nanchang 330006, China
| | - Jun Li
- Department of Pathophysiology, Medical College, Nanchang University, 461 Bayi Road, Nanchang 330006, China
| | - Xing-Hua Xiao
- Department of Pathophysiology, Medical College, Nanchang University, 461 Bayi Road, Nanchang 330006, China
| | - Xiang-Tong Lu
- Department of Pathology, Second Affiliated Hospital, Nanchang University, No. 1 Mingde Road, Nanchang 330006, China
| | - Lin-Chen Lv
- Department of Pathophysiology, Medical College, Nanchang University, 461 Bayi Road, Nanchang 330006, China
| | - Qing-Yun Huang
- Department of Pathophysiology, Medical College, Nanchang University, 461 Bayi Road, Nanchang 330006, China
| | - Wen Ding
- Department of Pathophysiology, Medical College, Nanchang University, 461 Bayi Road, Nanchang 330006, China
| | - Hong-Yan Zhang
- Department of Burn, The First Affiliated Hospital, Nanchang University, 17 Yongwaizheng Road, Nanschang 330066, China
| | - Li-Xia Xiong
- Department of Pathophysiology, Medical College, Nanchang University, 461 Bayi Road, Nanchang 330006, China
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Zhao J, Cai CK, Xie M, Liu JN, Wang BZ. Investigation of the therapy targets of Yi-Qi-Yang-Yin-Hua-Tan-Qu-Yu recipe on type 2 diabetes by serum proteome labeled with iTRAQ. JOURNAL OF ETHNOPHARMACOLOGY 2018; 224:1-14. [PMID: 29654829 DOI: 10.1016/j.jep.2018.03.027] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Revised: 02/28/2018] [Accepted: 03/22/2018] [Indexed: 06/08/2023]
Abstract
ETHNOPHARMACOLOGY RELEVANCE Based on basic theories of Chinese medicine, Yi-Qi-Yang-Yin-Hua-Tan-Qu-Yu (YQYYHTQY) recipe was constituted by eleven kinds of Chinese herbs and effective in treatment of type 2 diabetes (T2DM). But the therapy target was unclear. OBJECTIVE In this study, we used the serum proteome labeled by iTRAQ to find therapy target of YQYYHTQY recipe on T2DM. MATERIALS AND METHODS The rat model was induced by high-fat diet (HFD) and streptozotocin (STZ, 30 mg/kg). Drugs were administered to rats once daily for 14 days. Related laboratory parameters were observed. Serum proteome were compared between T2DM and YQYYHTQY group using the iTRAQ labeling quantitative proteomics technique. Functional differential proteins were analysis by STRING software. Target proteins were confirmed by ELISA kits. RESULTS Hyperglycemia, hyperinsulinemia, insulin resistance, decrease of glucose transporter, depilation, less activity, flock together, depression, ecchymosis of tongue and tail appearance, the typical diabetic patients "a little more than three" symptoms, as well as the decrease of grip strength, serum cyclic adenosine monophosphate (cAMP)/ cyclic guanosine monophosphate (cGMP) ratio, serum high density lipoprotein-cholesterol (HDL-C) and the increase of serum triglyceride (TG), total cholesterol (TC), low density lipoprotein-cholesterol (LDL-C), thromboxane B2 (TXB2)/ 6-keto prostaglandin F1α (6-keto PGF1α) ratio, endothelin-1 (ET-1) levels were found in T2DM group. After drugs treatment, all the above indexes almost were improved in different degrees and effect of YQYYHTQY recipe was superior to pioglitazone hydrochloride. In addition, there were 23 differential proteins, 5 up-regulated and 18 down-regulated proteins. Of them, there were 4 proteins related with diabetes, blood and behavior. Cell division control protein 42 homolog (CDC42) and Ras homolog gene family member A (RhoA) were the therapy targets of YQYYHTQY recipe on T2DM. CONCLUSIONS YQYYHTQY recipe showed therapy effect on T2DM. CDC42 and RhoA proteins were the therapy targets of YQYYHTQY recipe.
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Affiliation(s)
- Jing Zhao
- Department of Formula, Preclinical Medicine, Beijing University of Chinese Medicine, Beijing 100029, China; Institute of Integrated Bioinfomedicine & Translational Science, HKBU Shenzhen Research and Continuing Education, Shenzhen 518057, China.
| | - Cheng-Ke Cai
- School of Traditional Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing 100029, China
| | - Ming Xie
- Department of Formula, Preclinical Medicine, Beijing University of Chinese Medicine, Beijing 100029, China.
| | - Jin-Na Liu
- Department of Formula, Preclinical Medicine, Beijing University of Chinese Medicine, Beijing 100029, China; Shool of Combination of Chinese traditional and Western medicine, Hebei Medical University, Hebei 050017, China.
| | - Bang-Zhong Wang
- Department of Formula, Preclinical Medicine, Beijing University of Chinese Medicine, Beijing 100029, China.
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Veluthakal R, Chepurny OG, Leech CA, Schwede F, Holz GG, Thurmond DC. Restoration of Glucose-Stimulated Cdc42-Pak1 Activation and Insulin Secretion by a Selective Epac Activator in Type 2 Diabetic Human Islets. Diabetes 2018; 67:1999-2011. [PMID: 29986926 PMCID: PMC6152341 DOI: 10.2337/db17-1174] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 06/29/2018] [Indexed: 12/20/2022]
Abstract
Glucose metabolism stimulates cell division control protein 42 homolog (Cdc42)-p21-activated kinase (Pak1) activity and initiates filamentous actin (F-actin) cytoskeleton remodeling in pancreatic β-cells so that cytoplasmic secretory granules can translocate to the plasma membrane where insulin exocytosis occurs. Since glucose metabolism also generates cAMP in β-cells, the cross talk of cAMP signaling with Cdc42-Pak1 activation might be of fundamental importance to glucose-stimulated insulin secretion (GSIS). Previously, the type-2 isoform of cAMP-regulated guanine nucleotide exchange factor 2 (Epac2) was established to mediate a potentiation of GSIS by cAMP-elevating agents. Here we report that nondiabetic human islets and INS-1 832/13 β-cells treated with the selective Epac activator 8-pCPT-2'-O-Me-cAMP-AM exhibited Cdc42-Pak1 activation at 1 mmol/L glucose and that the magnitude of this effect was equivalent to that which was measured during stimulation with 20 mmol/L glucose in the absence of 8-pCPT-2'-O-Me-cAMP-AM. Conversely, the cAMP antagonist Rp-8-Br-cAMPS-pAB prevented glucose-stimulated Cdc42-Pak1 activation, thereby blocking GSIS while also increasing cellular F-actin content. Although islets from donors with type 2 diabetes had profound defects in glucose-stimulated Cdc42-Pak1 activation and insulin secretion, these defects were rescued by the Epac activator so that GSIS was restored. Collectively, these findings indicate an unexpected role for cAMP as a permissive or direct metabolic coupling factor in support of GSIS that is Epac2 and Cdc42-Pak1 regulated.
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Affiliation(s)
- Rajakrishnan Veluthakal
- Department of Molecular and Cellular Endocrinology, Diabetes and Metabolism Research Institute, Beckman Research Institute of City of Hope, Duarte, CA
| | - Oleg G Chepurny
- Department of Medicine, State University of New York, Upstate Medical University, Syracuse, NY
| | - Colin A Leech
- Department of Medicine, State University of New York, Upstate Medical University, Syracuse, NY
- Department of Surgery, State University of New York, Upstate Medical University, Syracuse, NY
| | | | - George G Holz
- Department of Medicine, State University of New York, Upstate Medical University, Syracuse, NY
- Department of Pharmacology, State University of New York, Upstate Medical University, Syracuse, NY
| | - Debbie C Thurmond
- Department of Molecular and Cellular Endocrinology, Diabetes and Metabolism Research Institute, Beckman Research Institute of City of Hope, Duarte, CA
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Nie J, Sun C, Chang Z, Musi N, Shi Y. SAD-A Promotes Glucose-Stimulated Insulin Secretion Through Phosphorylation and Inhibition of GDIα in Male Islet β Cells. Endocrinology 2018; 159:3036-3047. [PMID: 29873699 PMCID: PMC6693047 DOI: 10.1210/en.2017-03243] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 05/26/2018] [Indexed: 02/06/2023]
Abstract
Rho GDP-dissociation inhibitor (GDIα) inhibits glucose-stimulated insulin secretion (GSIS) in part by locking Rho GTPases in an inactive GDP-bound form. The onset of GSIS causes phosphorylation of GDIα at Ser174, a critical inhibitory site for GDIα, leading to the release of Rho GTPases and their subsequent activation. However, the kinase regulator(s) that catalyzes the phosphorylation of GDIα in islet β cells remains elusive. We propose that SAD-A, a member of AMP-activated protein kinase-related kinases that promotes GSIS as an effector kinase for incretin signaling, interacts with and inhibits GDIα through phosphorylation of Ser174 during the onset GSIS from islet β cells. Coimmunoprecipitation and phosphorylation analyses were carried out to identify the physical interaction and phosphorylation site of GDIα by SAD-A in the context of GSIS from INS-1 β cells and primary islets. We identified GDIα directly binds to SAD-A kinase domain and phosphorylated by SAD-A on Ser174, leading to dissociation of Rho GTPases from GDIα complexes. Accordingly, overexpression of SAD-A significantly stimulated GDIα phosphorylation at Ser174 in response to GSIS, which is dramatically potentiated by glucagonlike peptide-1, an incretin hormone. Conversely, SAD-A deficiency, which is mediated by short hairpin RNA transfection in INS-1 cells, significantly attenuated endogenous GDIα phosphorylation at Ser174. Consequently, coexpression of SAD-A completely prevented the inhibitory effect of GDIα on insulin secretion in islets. In summary, glucose and incretin stimulate insulin secretion through the phosphorylation of GDIα at Ser174 by SAD-A, which leads to the activation of Rho GTPases, culminating in insulin exocytosis.
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Affiliation(s)
- Jia Nie
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, San Antonio, Texas
- Correspondence: Jia Nie, PhD, Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, 15355 Lambda Drive, San Antonio, Texas 78245. E-mail:
| | - Chao Sun
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, San Antonio, Texas
| | - Zhijie Chang
- State Key Laboratory of Biomembrane and Membrane Biotechnology, School of Medicine, Tsinghua University, Beijing, China
| | - Nicolas Musi
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, San Antonio, Texas
| | - Yuguang Shi
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, San Antonio, Texas
- School of Basic Medical Sciences, Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing, Jiangsu, China
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Matsumura K, Tamasawa N, Daimon M. Possible Insulinotropic Action of Apolipoprotein A-I Through the ABCA1/Cdc42/cAMP/PKA Pathway in MIN6 Cells. Front Endocrinol (Lausanne) 2018; 9:645. [PMID: 30425683 PMCID: PMC6218629 DOI: 10.3389/fendo.2018.00645] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 10/11/2018] [Indexed: 01/07/2023] Open
Abstract
Aims/Introduction: We studied the mechanisms for the possible insulinotropic action of apolipoprotein (Apo) A-I in mouse insulinoma (MIN6) cells. Materials and Methods: The effects of ApoA-I on cAMP production and glucose-stimulated insulin secretion (GSIS), and the dose dependency (ApoA-I at 5, 10, 25, and 50 μg/ml) were determined using MIN6 cells. The effects of the small-interference ribonucleic acid (siRNA) of ATP-binding cassette transporter A1(ABCA1) and Cell division control protein 42 homolog (Cdc42) on the insulinotropic action of ApoA-I was studied, as well as mRNA and protein levels of ABCA1 and Cdc42. Then, the influence of cAMP inhibitor SQ22536, and the cAMP-dependent protein kinase inhibitor Rp-cAMPS on ApoA-I action were studied. Results: Addition of ApoA-I produced cAMP and increased insulin secretion, dose-dependently in high glucose concentration (25 mmmol/l). and ABCA1 protein and Cdc42 mRNA and protein were also enhanced. Specific ABCA1 and Cdc42 siRNA significantly decreased the effects of ApoA-I on insulin secretion compared with negative controls. Manifestations of ABCA1 and Cdc42 mRNA and protein were less than that of the negative control group. Both cAMP inhibiror (SQ22536) and protein kinases inhibitor (Rp-cAMPS) strongly inhibited the effects of ApoA-I on insulin secretion. Conclusions: We demonstrated that ApoA-I enhances glucose-stimulated insulin release in high glucose at least partially through the ABCA1/Cdc42/cAMP/ Protein kinase A (PKA) pathway.
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Affiliation(s)
- Koki Matsumura
- Graduate School of Medicine and School of Medicine, Hirosaki University, Hirosaki, Japan
- *Correspondence: Koki Matsumura
| | | | - Makoto Daimon
- Graduate School of Medicine and School of Medicine, Hirosaki University, Hirosaki, Japan
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Rorsman P, Ashcroft FM. Pancreatic β-Cell Electrical Activity and Insulin Secretion: Of Mice and Men. Physiol Rev 2018; 98:117-214. [PMID: 29212789 PMCID: PMC5866358 DOI: 10.1152/physrev.00008.2017] [Citation(s) in RCA: 433] [Impact Index Per Article: 72.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Revised: 05/30/2017] [Accepted: 06/18/2017] [Indexed: 12/14/2022] Open
Abstract
The pancreatic β-cell plays a key role in glucose homeostasis by secreting insulin, the only hormone capable of lowering the blood glucose concentration. Impaired insulin secretion results in the chronic hyperglycemia that characterizes type 2 diabetes (T2DM), which currently afflicts >450 million people worldwide. The healthy β-cell acts as a glucose sensor matching its output to the circulating glucose concentration. It does so via metabolically induced changes in electrical activity, which culminate in an increase in the cytoplasmic Ca2+ concentration and initiation of Ca2+-dependent exocytosis of insulin-containing secretory granules. Here, we review recent advances in our understanding of the β-cell transcriptome, electrical activity, and insulin exocytosis. We highlight salient differences between mouse and human β-cells, provide models of how the different ion channels contribute to their electrical activity and insulin secretion, and conclude by discussing how these processes become perturbed in T2DM.
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Affiliation(s)
- Patrik Rorsman
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford, United Kingdom; Department of Neuroscience and Physiology, Metabolic Research Unit, Göteborg, Sweden; and Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Frances M Ashcroft
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford, United Kingdom; Department of Neuroscience and Physiology, Metabolic Research Unit, Göteborg, Sweden; and Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
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Ottosson-Laakso E, Krus U, Storm P, Prasad RB, Oskolkov N, Ahlqvist E, Fadista J, Hansson O, Groop L, Vikman P. Glucose-Induced Changes in Gene Expression in Human Pancreatic Islets: Causes or Consequences of Chronic Hyperglycemia. Diabetes 2017; 66:3013-3028. [PMID: 28882899 DOI: 10.2337/db17-0311] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2017] [Accepted: 08/30/2017] [Indexed: 11/13/2022]
Abstract
Dysregulation of gene expression in islets from patients with type 2 diabetes (T2D) might be causally involved in the development of hyperglycemia, or it could develop as a consequence of hyperglycemia (i.e., glucotoxicity). To separate the genes that could be causally involved in pathogenesis from those likely to be secondary to hyperglycemia, we exposed islets from human donors to normal or high glucose concentrations for 24 h and analyzed gene expression. We compared these findings with gene expression in islets from donors with normal glucose tolerance and hyperglycemia (including T2D). The genes whose expression changed in the same direction after short-term glucose exposure, as in T2D, were considered most likely to be a consequence of hyperglycemia. Genes whose expression changed in hyperglycemia but not after short-term glucose exposure, particularly those that also correlated with insulin secretion, were considered the strongest candidates for causal involvement in T2D. For example, ERO1LB, DOCK10, IGSF11, and PRR14L were downregulated in donors with hyperglycemia and correlated positively with insulin secretion, suggesting a protective role, whereas TMEM132C was upregulated in hyperglycemia and correlated negatively with insulin secretion, suggesting a potential pathogenic role. This study provides a catalog of gene expression changes in human pancreatic islets after exposure to glucose.
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Affiliation(s)
- Emilia Ottosson-Laakso
- Lund University Diabetes Centre, Department of Clinical Sciences, Lund University, Malmö, Sweden
| | - Ulrika Krus
- Lund University Diabetes Centre, Department of Clinical Sciences, Lund University, Malmö, Sweden
| | - Petter Storm
- Lund University Diabetes Centre, Department of Clinical Sciences, Lund University, Malmö, Sweden
| | - Rashmi B Prasad
- Lund University Diabetes Centre, Department of Clinical Sciences, Lund University, Malmö, Sweden
| | - Nikolay Oskolkov
- Lund University Diabetes Centre, Department of Clinical Sciences, Lund University, Malmö, Sweden
| | - Emma Ahlqvist
- Lund University Diabetes Centre, Department of Clinical Sciences, Lund University, Malmö, Sweden
| | - João Fadista
- Department of Epidemiology Research, Statens Serum Institut, Copenhagen, Denmark
| | - Ola Hansson
- Lund University Diabetes Centre, Department of Clinical Sciences, Lund University, Malmö, Sweden
| | - Leif Groop
- Lund University Diabetes Centre, Department of Clinical Sciences, Lund University, Malmö, Sweden
- Finnish Institute of Molecular Medicine, University of Helsinki, Helsinki, Finland
| | - Petter Vikman
- Lund University Diabetes Centre, Department of Clinical Sciences, Lund University, Malmö, Sweden
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Shimada H, Kogure N, Noro E, Kudo M, Sugawara K, Sato I, Shimizu K, Kobayashi M, Suzuki D, Parvin R, Saito-Ito T, Uruno A, Saito-Hakoda A, Rainey WE, Ito S, Yokoyama A, Sugawara A. High glucose stimulates expression of aldosterone synthase ( CYP11B2) and secretion of aldosterone in human adrenal cells. FEBS Open Bio 2017; 7:1410-1421. [PMID: 28904869 PMCID: PMC5586344 DOI: 10.1002/2211-5463.12277] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2016] [Revised: 06/11/2017] [Accepted: 07/26/2017] [Indexed: 11/09/2022] Open
Abstract
Aldosterone synthase is the key rate‐limiting enzyme in adrenal aldosterone production, and induction of its gene (CYP11B2) results in the progression of hypertension. As hypertension is a frequent complication among patients with diabetes, we set out to elucidate the link between diabetes mellitus and hypertension. We examined the effects of high glucose on CYP11B2 expression and aldosterone production using human adrenal H295R cells and a stable H295R cell line expressing a CYP11B2 5′‐flanking region/luciferase cDNA chimeric construct. d‐glucose (d‐glu), but not its enantiomer l‐glucose, dose dependently induced CYP11B2 transcription and mRNA expression. A high concentration (450 mg·dL−1) of d‐glu time dependently induced CYP11B2 transcription and mRNA expression. Moreover, high glucose stimulated secretion of aldosterone into the media. Transient transfection studies using deletion mutants/nerve growth factor‐induced clone B (NGFIB) response element 1 (NBRE‐1) point mutant of CYP11B2 5′‐flanking region revealed that the NBRE‐1 element, known to be activated by transcription factors NGFIB and NURR1, was responsible for the high glucose‐mediated effect. High glucose also induced the mRNA expression of these transcription factors, especially that of NURR1, but NURR1 knockdown using its siRNA did not affect high glucose‐induced CYP11B2 mRNA expression. Taken together, it is speculated that high glucose may induce CYP11B2 transcription via the NBRE‐1 element in its 5′‐flanking region, resulting in the increase in aldosterone production although high glucose‐induced NURR1 is not directly involved in the effect. Additionally, glucose metabolism and calcium channels were found to be involved in the high glucose effect. Our observations suggest one possible explanation for the high incidence of hypertension in patients with diabetes.
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Affiliation(s)
- Hiroki Shimada
- Department of Molecular Endocrinology Tohoku University Graduate School of Medicine Sendai Miyagi Japan
| | - Naotaka Kogure
- Department of Molecular Endocrinology Tohoku University Graduate School of Medicine Sendai Miyagi Japan
| | - Erika Noro
- Department of Molecular Endocrinology Tohoku University Graduate School of Medicine Sendai Miyagi Japan
| | - Masataka Kudo
- Division of Nephrology, Endocrinology and Vascular Medicine Tohoku University Graduate School of Medicine Sendai Miyagi Japan
| | - Kaori Sugawara
- Department of Molecular Endocrinology Tohoku University Graduate School of Medicine Sendai Miyagi Japan
| | - Ikuko Sato
- Department of Molecular Endocrinology Tohoku University Graduate School of Medicine Sendai Miyagi Japan
| | - Kyoko Shimizu
- Department of Molecular Endocrinology Tohoku University Graduate School of Medicine Sendai Miyagi Japan
| | - Makoto Kobayashi
- Department of Molecular Endocrinology Tohoku University Graduate School of Medicine Sendai Miyagi Japan
| | - Dai Suzuki
- Department of Pediatrics Tohoku University Graduate School of Medicine Sendai Miyagi Japan
| | - Rehana Parvin
- Department of Molecular Endocrinology Tohoku University Graduate School of Medicine Sendai Miyagi Japan
| | - Takako Saito-Ito
- Department of Molecular Endocrinology Tohoku University Graduate School of Medicine Sendai Miyagi Japan
| | - Akira Uruno
- Department of Medical Biochemistry Tohoku University Graduate School of Medicine Sendai Miyagi Japan
| | - Akiko Saito-Hakoda
- Department of Molecular Endocrinology Tohoku University Graduate School of Medicine Sendai Miyagi Japan
| | - William E Rainey
- Department of Molecular and Integrative Physiology University of Michigan Medical School Ann Arbor MI USA
| | - Sadayoshi Ito
- Division of Nephrology, Endocrinology and Vascular Medicine Tohoku University Graduate School of Medicine Sendai Miyagi Japan
| | - Atsushi Yokoyama
- Department of Molecular Endocrinology Tohoku University Graduate School of Medicine Sendai Miyagi Japan
| | - Akira Sugawara
- Department of Molecular Endocrinology Tohoku University Graduate School of Medicine Sendai Miyagi Japan
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Sebastiani G, Guarino E, Grieco GE, Formichi C, Delli Poggi C, Ceccarelli E, Dotta F. Circulating microRNA (miRNA) Expression Profiling in Plasma of Patients with Gestational Diabetes Mellitus Reveals Upregulation of miRNA miR-330-3p. Front Endocrinol (Lausanne) 2017; 8:345. [PMID: 29312141 PMCID: PMC5732927 DOI: 10.3389/fendo.2017.00345] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Accepted: 11/27/2017] [Indexed: 12/20/2022] Open
Abstract
Gestational diabetes mellitus (GDM) is characterized by insulin resistance accompanied by low/absent beta-cell compensatory adaptation to the increased insulin demand. Although the molecular mechanisms and factors acting on beta-cell compensatory response during pregnancy have been partially elucidated and reported, those inducing an impaired beta-cell compensation and function, thus evolving in GDM, have yet to be fully addressed. MicroRNAs (miRNAs) are a class of small endogenous non-coding RNAs, which negatively modulate gene expression through their sequence-specific binding to 3'UTR of mRNA target. They have been described as potent modulators of cell survival and proliferation and, furthermore, as orchestrating molecules of beta-cell compensatory response and function in diabetes. Moreover, it has been reported that miRNAs can be actively secreted by cells and found in many biological fluids (e.g., serum/plasma), thus representing both optimal candidate disease biomarkers and mediators of tissues crosstalk(s). Here, we analyzed the expression profiles of circulating miRNAs in plasma samples obtained from n = 21 GDM patients and from n = 10 non-diabetic control pregnant women (24-33 weeks of gestation) using TaqMan array microfluidics cards followed by RT-real-time PCR single assay validation. The results highlighted the upregulation of miR-330-3p in plasma of GDM vs non-diabetics. Furthermore, the analysis of miR-330-3p expression levels revealed a bimodally distributed GDM patients group characterized by high or low circulating miR-330 expression and identified as GDM-miR-330high and GDM-miR-330low. Interestingly, GDM-miR-330high subgroup retained lower levels of insulinemia, inversely correlated to miR-330-3p expression levels, and a significant higher rate of primary cesarean sections. Finally, miR-330-3p target genes analysis revealed major modulators of beta-cell proliferation and of insulin secretion, such as the experimentally validated genes E2F1 and CDC42 as well as AGT2R2, a gene involved in the differentiation of mature beta-cells. In conclusion, we demonstrated that plasma miR-330-3p could be of help in identifying GDM patients with potential worse gestational diabetes outcome; in GDM, miR-330-3p may directly be transferred from plasma to beta-cells thus modulating key target genes involved in proliferation, differentiation, and insulin secretion.
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Affiliation(s)
- Guido Sebastiani
- Diabetes Unit, Department of Medicine, Surgery and Neurosciences, University of Siena, Siena, Italy
- Fondazione Umberto di Mario, Toscana Life Sciences, Siena, Italy
| | - Elisa Guarino
- Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | - Giuseppina Emanuela Grieco
- Diabetes Unit, Department of Medicine, Surgery and Neurosciences, University of Siena, Siena, Italy
- Fondazione Umberto di Mario, Toscana Life Sciences, Siena, Italy
| | - Caterina Formichi
- Diabetes Unit, Department of Medicine, Surgery and Neurosciences, University of Siena, Siena, Italy
- Fondazione Umberto di Mario, Toscana Life Sciences, Siena, Italy
| | - Chiara Delli Poggi
- Diabetes Unit, Department of Medicine, Surgery and Neurosciences, University of Siena, Siena, Italy
- Fondazione Umberto di Mario, Toscana Life Sciences, Siena, Italy
| | - Elena Ceccarelli
- Diabetes Unit, Department of Medicine, Surgery and Neurosciences, University of Siena, Siena, Italy
| | - Francesco Dotta
- Diabetes Unit, Department of Medicine, Surgery and Neurosciences, University of Siena, Siena, Italy
- Fondazione Umberto di Mario, Toscana Life Sciences, Siena, Italy
- Azienda Ospedaliera Universitaria Senese, Siena, Italy
- *Correspondence: Francesco Dotta,
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Pingitore A, Caroleo MC, Cione E, Castañera Gonzalez R, Huang GC, Persaud SJ. Fine tuning of insulin secretion by release of nerve growth factor from mouse and human islet β-cells. Mol Cell Endocrinol 2016; 436:23-32. [PMID: 27424144 DOI: 10.1016/j.mce.2016.07.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Revised: 06/13/2016] [Accepted: 07/11/2016] [Indexed: 11/21/2022]
Abstract
Nerve growth factor (NGF) is a protein required for neuronal development that also has regulatory functions in non-neuronal cells. Both NGF and its membrane receptors trkA and p75(NTR) are expressed by islet β-cells. In this study we dynamically profiled NGF secretion from islets and used selective trkA and p75(NTR) inhibitors to identify the role of endogenous NGF in β-cell stimulus-secretion coupling. NGF secretion from mouse islets was transient and did not accompany the sustained second phase of glucose-induced insulin secretion. Despite being present in human islets, NGF was not released at sufficient levels to be quantified. Inhibition of NGF signaling through trkA and p75(NTR) increased basal insulin secretion from both human and mouse islets, but impaired glucose-stimulated insulin secretion. These data support a role for islet NGF in fine-tuning insulin secretion, to both maintain a low basal level of insulin output and contribute to the biphasic secretory response to glucose.
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Affiliation(s)
- Attilio Pingitore
- Diabetes Research Group, Diabetes & Nutritional Sciences Division, King's College London, Guy's Campus, SE1 1UL, London, United Kingdom
| | - Maria Cristina Caroleo
- Department of Pharmacy, Nutritional and Health Sciences, University of Calabria, Via Savinio, 87036, Rende, Italy
| | - Erika Cione
- Department of Pharmacy, Nutritional and Health Sciences, University of Calabria, Via Savinio, 87036, Rende, Italy
| | - Ramon Castañera Gonzalez
- Department of General Surgery, Rio Carrión Hospital, University Hospital Complex of Palencia, 34005, Palencia, Spain
| | - Guo Cai Huang
- Diabetes Research Group, Diabetes & Nutritional Sciences Division, King's College London, Guy's Campus, SE1 1UL, London, United Kingdom
| | - Shanta J Persaud
- Diabetes Research Group, Diabetes & Nutritional Sciences Division, King's College London, Guy's Campus, SE1 1UL, London, United Kingdom.
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Bergeron V, Ghislain J, Poitout V. The P21-activated kinase PAK4 is implicated in fatty-acid potentiation of insulin secretion downstream of free fatty acid receptor 1. Islets 2016; 8:157-164. [PMID: 27700527 PMCID: PMC5161145 DOI: 10.1080/19382014.2016.1243191] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
Free fatty acid receptor 1 (FFA1/GPR40) plays a key role in the potentiation of glucose-stimulated insulin secretion by fatty acids in pancreatic β cells. We previously demonstrated that GPR40 signaling leads to cortical actin remodeling and potentiates the second phase of insulin secretion. In this study, we examined the role of p21 activated kinase 4 (PAK4), a known regulator of cytoskeletal dynamics, in GPR40-dependent potentiation of insulin secretion. The fatty acid oleate induced PAK4 phosphorylation in human islets, in isolated mouse islets and in the insulin secreting cell line INS832/13. However, oleate-induced PAK4 phosphorylation was not observed in GPR40-null mouse islets. siRNA-mediated knockdown of PAK4 in INS832/13 cells abrogated the potentiation of insulin secretion by oleate, whereas PAK7 knockdown had no effect. Our results indicate that PAK4 plays an important role in the potentiation of insulin secretion by fatty acids downstream of GPR40.
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Affiliation(s)
- Valérie Bergeron
- Montreal Diabetes Research Center, CRCHUM, QC, Canada
- Department of Medicine, University of Montreal, QC, Canada
| | | | - Vincent Poitout
- Montreal Diabetes Research Center, CRCHUM, QC, Canada
- Department of Medicine, University of Montreal, QC, Canada
- CONTACT Vincent Poitout CRCHUM, 900 Saint-Denis Street, Montreal, QC, Canada, H2X 0A9
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Tsompanidis A, Vafiadaki E, Blüher S, Kalozoumi G, Sanoudou D, Mantzoros CS. Ciliary neurotrophic factor upregulates follistatin and Pak1, causes overexpression of muscle differentiation related genes and downregulation of established atrophy mediators in skeletal muscle. Metabolism 2016; 65:915-25. [PMID: 27173470 DOI: 10.1016/j.metabol.2016.03.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/01/2016] [Revised: 03/01/2016] [Accepted: 03/09/2016] [Indexed: 10/22/2022]
Abstract
INTRODUCTION The Ciliary Neurotrophic Factor (CNTF) is a pluripotent cytokine with anorexigenic actions in the hypothalamus that improves insulin sensitivity, increases energy expenditure and induces weight loss. Since CNTF also has an established myotrophic role, we sought to examine whether skeletal muscle contributes to the CNTF-induced metabolic improvement and identify the molecular mechanisms mediating these effects. METHODS We used a mouse model of diet-induced obesity, to which high or low CNTF doses were administered for 7days. Whole transcriptome expression levels were analyzed in dissected soleus muscles using microarrays and data were then confirmed using qRT-PCR. RESULTS We demonstrate that CNTF administration significantly downregulates leptin, while it upregulates follistatin and Pak1; a molecule associated with insulin sensitization in skeletal muscle. A significant overexpression of muscle differentiation related genes and downregulation of established atrophy mediators was observed. CONCLUSIONS The overall gene expression changes suggest an indirect, beneficial effect of CNTF on metabolism, energy expenditure and insulin sensitivity, exerted by the pronounced stimulation of muscle growth, with similarities to the described effect of follistatin and the activation of the Akt pathway in skeletal muscle.
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Affiliation(s)
- Alexandros Tsompanidis
- Clinical Genomics and Pharmacogenomics Unit, 4th Department of Internal Medicine, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Elizabeth Vafiadaki
- Molecular Biology Division, Biomedical Research Foundation of the Academy of Athens, Athens, Greece
| | - Susann Blüher
- Division of Endocrinology, Diabetes, and Metabolism, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Georgia Kalozoumi
- Clinical Genomics and Pharmacogenomics Unit, 4th Department of Internal Medicine, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Despina Sanoudou
- Clinical Genomics and Pharmacogenomics Unit, 4th Department of Internal Medicine, Medical School, National and Kapodistrian University of Athens, Athens, Greece; Molecular Biology Division, Biomedical Research Foundation of the Academy of Athens, Athens, Greece.
| | - Christos S Mantzoros
- Division of Endocrinology, Diabetes, and Metabolism, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
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Yamaoka M, Ando T, Terabayashi T, Okamoto M, Takei M, Nishioka T, Kaibuchi K, Matsunaga K, Ishizaki R, Izumi T, Niki I, Ishizaki T, Kimura T. PI3K regulates endocytosis after insulin secretion by mediating signaling crosstalk between Arf6 and Rab27a. J Cell Sci 2015; 129:637-49. [PMID: 26683831 DOI: 10.1242/jcs.180141] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Accepted: 12/03/2015] [Indexed: 01/12/2023] Open
Abstract
In secretory cells, endocytosis is coupled to exocytosis to enable proper secretion. Although endocytosis is crucial to maintain cellular homeostasis before and after secretion, knowledge about secretagogue-induced endocytosis in secretory cells is still limited. Here, we searched for proteins that interacted with the Rab27a GTPase-activating protein (GAP) EPI64 (also known as TBC1D10A) and identified the Arf6 guanine-nucleotide-exchange factor (GEF) ARNO (also known as CYTH2) in pancreatic β-cells. We found that the insulin secretagogue glucose promotes phosphatidylinositol (3,4,5)-trisphosphate (PIP3) generation through phosphoinositide 3-kinase (PI3K), thereby recruiting ARNO to the intracellular side of the plasma membrane. Peripheral ARNO promotes clathrin assembly through its GEF activity for Arf6 and regulates the early stage of endocytosis. We also found that peripheral ARNO recruits EPI64 to the same area and that the interaction requires glucose-induced endocytosis in pancreatic β-cells. Given that GTP- and GDP-bound Rab27a regulate exocytosis and the late stage of endocytosis, our results indicate that the glucose-induced activation of PI3K plays a pivotal role in exocytosis-endocytosis coupling, and that ARNO and EPI64 regulate endocytosis at distinct stages.
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Affiliation(s)
- Mami Yamaoka
- Department of Pharmacology, Oita University Faculty of Medicine, 1-1 Idaigaoka, Hasama, Yufu, Oita 879-5593, Japan
| | - Tomomi Ando
- Department of Pharmacology, Oita University Faculty of Medicine, 1-1 Idaigaoka, Hasama, Yufu, Oita 879-5593, Japan
| | - Takeshi Terabayashi
- Department of Pharmacology, Oita University Faculty of Medicine, 1-1 Idaigaoka, Hasama, Yufu, Oita 879-5593, Japan
| | - Mitsuhiro Okamoto
- Department of Pharmacology, Oita University Faculty of Medicine, 1-1 Idaigaoka, Hasama, Yufu, Oita 879-5593, Japan
| | - Masahiro Takei
- Department of Pharmacology, Oita University Faculty of Medicine, 1-1 Idaigaoka, Hasama, Yufu, Oita 879-5593, Japan
| | - Tomoki Nishioka
- Department of Cell Pharmacology, Graduate School of Medicine, Nagoya University, 65 Tsurumai, Showa, Nagoya, Aichi 466-8550, Japan
| | - Kozo Kaibuchi
- Department of Cell Pharmacology, Graduate School of Medicine, Nagoya University, 65 Tsurumai, Showa, Nagoya, Aichi 466-8550, Japan JST, CREST, 4-1-8 Honcho, Kawaguchi 332-0012, Japan
| | - Kohichi Matsunaga
- Laboratory of Molecular Endocrinology and Metabolism, Department of Molecular Medicine, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi, Gunma 371-8512, Japan
| | - Ray Ishizaki
- Laboratory of Molecular Endocrinology and Metabolism, Department of Molecular Medicine, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi, Gunma 371-8512, Japan
| | - Tetsuro Izumi
- Laboratory of Molecular Endocrinology and Metabolism, Department of Molecular Medicine, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi, Gunma 371-8512, Japan
| | - Ichiro Niki
- Department of Pharmacology, Oita University Faculty of Medicine, 1-1 Idaigaoka, Hasama, Yufu, Oita 879-5593, Japan
| | - Toshimasa Ishizaki
- Department of Pharmacology, Oita University Faculty of Medicine, 1-1 Idaigaoka, Hasama, Yufu, Oita 879-5593, Japan
| | - Toshihide Kimura
- Department of Pharmacology, Oita University Faculty of Medicine, 1-1 Idaigaoka, Hasama, Yufu, Oita 879-5593, Japan
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Veluthakal R, Tunduguru R, Arora DK, Sidarala V, Syeda K, Vlaar CP, Thurmond DC, Kowluru A. VAV2, a guanine nucleotide exchange factor for Rac1, regulates glucose-stimulated insulin secretion in pancreatic beta cells. Diabetologia 2015. [PMID: 26224100 PMCID: PMC4591202 DOI: 10.1007/s00125-015-3707-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
AIMS/HYPOTHESIS Rho GTPases (Ras-related C3 botulinum toxin substrate 1 [Rac1] and cell division cycle 42 [Cdc42]) have been shown to regulate glucose-stimulated insulin secretion (GSIS) via cytoskeletal remodelling, trafficking and fusion of insulin-secretory granules with the plasma membrane. GTP loading of these G proteins, which is facilitated by GDP/GTP exchange factors, is a requisite step in the regulation of downstream effector proteins. Guanine nucleotide exchange factor VAV2 (VAV2), a member of the Dbl family of proteins, has been identified as one of the GDP/GTP exchange factors for Rac1. Despite recent evidence on the regulatory roles of VAV2 in different cell types, roles of this guanine nucleotide exchange factor in the signalling events leading to GSIS remain undefined. Using immunological, short interfering RNA (siRNA), pharmacological and microscopic approaches we investigated the role of VAV2 in GSIS from islet beta cells. METHODS Co-localisation of Rac1 and VAV2 was determined by Triton X-114 phase partition and confocal microscopy. Glucose-induced actin remodelling was quantified by live cell imaging using the LifeAct-GFP fluorescent biosensor. Rac1 activation was determined by G protein linked immunosorbent assay (G-LISA). RESULTS Western blotting indicated that VAV2 is expressed in INS-1 832/13 beta cells, normal rat islets and human islets. Vav2 siRNA markedly attenuated GSIS in INS-1 832/13 cells. Ehop-016, a newly discovered small molecule inhibitor of the VAV2-Rac1 interaction, or siRNA-mediated knockdown of VAV2 markedly attenuated glucose-induced Rac1 activation and GSIS in INS-1 832/13 cells. Pharmacological findings were recapitulated in primary rat islets. A high glucose concentration promoted co-localisation of Rac1 and VAV2. Real-time imaging in live cells indicated a significant inhibition of glucose-induced cortical actin remodelling by Ehop-016. CONCLUSIONS/INTERPRETATION Our data provide the first evidence to implicate VAV2 in glucose-induced Rac1 activation, actin remodelling and GSIS in pancreatic beta cells.
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Affiliation(s)
- Rajakrishnan Veluthakal
- Beta Cell Biochemistry Laboratory, John D. Dingell VA Medical Center, 4646 John R, Detroit, MI, 48201, USA
- Department of Pediatrics, Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Ragadeepthi Tunduguru
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Daleep Kumar Arora
- Immunobiology and Cancer Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Vaibhav Sidarala
- Beta Cell Biochemistry Laboratory, John D. Dingell VA Medical Center, 4646 John R, Detroit, MI, 48201, USA
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy, Wayne State University, Detroit, MI, USA
| | - Khadija Syeda
- Beta Cell Biochemistry Laboratory, John D. Dingell VA Medical Center, 4646 John R, Detroit, MI, 48201, USA
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy, Wayne State University, Detroit, MI, USA
| | - Cornelis P Vlaar
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Puerto Rico, Medical Sciences Campus, San Juan, Puerto Rico
| | - Debbie C Thurmond
- Department of Pediatrics, Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN, USA
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Anjaneyulu Kowluru
- Beta Cell Biochemistry Laboratory, John D. Dingell VA Medical Center, 4646 John R, Detroit, MI, 48201, USA.
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy, Wayne State University, Detroit, MI, USA.
- B-4237 Research Service, John D. Dingell VA Medical Center, 4646 John R, Detroit, MI, 48201, USA.
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48
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Fan F, Ji C, Wu Y, Ferguson SM, Tamarina N, Philipson LH, Lou X. Dynamin 2 regulates biphasic insulin secretion and plasma glucose homeostasis. J Clin Invest 2015; 125:4026-41. [PMID: 26413867 DOI: 10.1172/jci80652] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Accepted: 08/20/2015] [Indexed: 12/18/2022] Open
Abstract
Alterations in insulin granule exocytosis and endocytosis are paramount to pancreatic β cell dysfunction in diabetes mellitus. Here, using temporally controlled gene ablation specifically in β cells in mice, we identified an essential role of dynamin 2 GTPase in preserving normal biphasic insulin secretion and blood glucose homeostasis. Dynamin 2 deletion in β cells caused glucose intolerance and substantial reduction of the second phase of glucose-stimulated insulin secretion (GSIS); however, mutant β cells still maintained abundant insulin granules, with no signs of cell surface expansion. Compared with control β cells, real-time capacitance measurements demonstrated that exocytosis-endocytosis coupling was less efficient but not abolished; clathrin-mediated endocytosis (CME) was severely impaired at the step of membrane fission, which resulted in accumulation of clathrin-coated endocytic intermediates on the plasma membrane. Moreover, dynamin 2 ablation in β cells led to striking reorganization and enhancement of actin filaments, and insulin granule recruitment and mobilization were impaired at the later stage of GSIS. Together, our results demonstrate that dynamin 2 regulates insulin secretory capacity and dynamics in vivo through a mechanism depending on CME and F-actin remodeling. Moreover, this study indicates a potential pathophysiological link between endocytosis and diabetes mellitus.
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49
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Sugawara K, Shibasaki T, Takahashi H, Seino S. Structure and functional roles of Epac2 (Rapgef4). Gene 2015; 575:577-83. [PMID: 26390815 DOI: 10.1016/j.gene.2015.09.029] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Revised: 08/13/2015] [Accepted: 09/15/2015] [Indexed: 10/24/2022]
Abstract
Epac (exchange protein activated by cyclic-AMP) 2 is a direct target of 3'-5'-cyclic adenosine monophosphate (cAMP) and is involved in cAMP-mediated signal transduction through activation of the Ras-like small GTPase Rap. Crystallographic analyses revealed that activation of Epac2 by cAMP is accompanied by dynamic structural changes. Epac2 is expressed mainly in brain, neuroendocrine and endocrine tissues, and is involved in diverse cellular functions in the tissues. In this review, we summarize the structure and function of Epac2. We also discuss the physiological and pathophysiological roles of Epac2, and the possibility of Epac2 as a therapeutic target.
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Affiliation(s)
- Kenji Sugawara
- Division of Diabetes and Endocrinology, Kobe University Graduate School of Medicine, Kobe, Japan; Division of Molecular and Metabolic Medicine, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Tadao Shibasaki
- Division of Molecular and Metabolic Medicine, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Harumi Takahashi
- Division of Molecular and Metabolic Medicine, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Susumu Seino
- Division of Molecular and Metabolic Medicine, Kobe University Graduate School of Medicine, Kobe, Japan.
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da Silva Lippo BR, Batista TM, de Rezende LF, Cappelli AP, Camargo RL, Branco RCS, Barbosa Sampaio HC, Protzek AOP, Wanderley MI, Arantes VC, Corat MAF, Carneiro EM, Udrisar DP, Wanderley AG, Ferreira F. Low-protein diet disrupts the crosstalk between the PKA and PKC signaling pathways in isolated pancreatic islets. J Nutr Biochem 2015; 26:556-62. [DOI: 10.1016/j.jnutbio.2014.12.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Revised: 11/26/2014] [Accepted: 12/10/2014] [Indexed: 10/24/2022]
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