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Ghiasi SM, Christensen NM, Pedersen PA, Skovhøj EZ, Novak I. Imaging of extracellular and intracellular ATP in pancreatic beta cells reveals correlation between glucose metabolism and purinergic signalling. Cell Signal 2024; 117:111109. [PMID: 38373668 DOI: 10.1016/j.cellsig.2024.111109] [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: 12/01/2023] [Revised: 01/24/2024] [Accepted: 02/15/2024] [Indexed: 02/21/2024]
Abstract
Adenosine triphosphate (ATP) is a universal energy molecule and yet cells release it and extracellular ATP is an important signalling molecule between cells. Monitoring of ATP levels outside of cells is important for our understanding of physiological and pathophysiological processes in cells/tissues. Here, we focus on pancreatic beta cells (INS-1E) and test the hypothesis that there is an association between intra- and extracellular ATP levels which depends on glucose provision. We imaged real-time changes in extracellular ATP in pancreatic beta cells using two sensors tethered to extracellular aspects of the plasma membrane (eATeam3.10, iATPSnFR1.0). Increase in glucose induced fast micromolar ATP release to the cell surface, depending on glucose concentrations. Chronic pre-treatment with glucose increased the basal ATP signal. In addition, we co-expressed intracellular ATP sensors (ATeam1.30, PercevalHR) in the same cultures and showed that glucose induced fast increases in extracellular and intracellular ATP. Glucose and extracellular ATP stimulated glucose transport monitored by the glucose sensor (FLII12Pglu-700uDelta6). In conclusion, we propose that in beta cells there is a dynamic relation between intra- and extracellular ATP that depends on glucose transport and metabolism and these processes may be tuned by purinergic signalling. Future development of ATP sensors for imaging may aid development of novel approaches to target extracellular ATP in, for example, type 2 diabetes mellitus therapy.
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Affiliation(s)
- Seyed M Ghiasi
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Denmark
| | - Nynne M Christensen
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Denmark
| | - Per A Pedersen
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Denmark
| | - Emil Z Skovhøj
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Denmark
| | - Ivana Novak
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Denmark.
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2
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Mateus Gonçalves L, Fahd Qadir MM, Boulina M, Makhmutova M, Pereira E, Almaça J. Pericyte dysfunction and impaired vasomotion are hallmarks of islets during the pathogenesis of type 1 diabetes. Cell Rep 2023; 42:112913. [PMID: 37531253 PMCID: PMC10529889 DOI: 10.1016/j.celrep.2023.112913] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 05/26/2023] [Accepted: 07/16/2023] [Indexed: 08/04/2023] Open
Abstract
Pancreatic islets are endocrine organs that depend on their microvasculature to function. Along with endothelial cells, pericytes comprise the islet microvascular network. These mural cells are crucial for microvascular stability and function, but it is not known if/how they are affected during the development of type 1 diabetes (T1D). Here, we investigate islet pericyte density, phenotype, and function using living pancreas slices from donors without diabetes, donors with a single T1D-associated autoantibody (GADA+), and recent onset T1D cases. Our data show that islet pericyte and capillary responses to vasoactive stimuli are impaired early on in T1D. Microvascular dysfunction is associated with a switch in the phenotype of islet pericytes toward myofibroblasts. Using publicly available RNA sequencing (RNA-seq) data, we further found that transcriptional alterations related to endothelin-1 signaling and vascular and extracellular matrix (ECM) remodeling are hallmarks of single autoantibody (Aab)+ donor pancreata. Our data show that microvascular dysfunction is present at early stages of islet autoimmunity.
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Affiliation(s)
- Luciana Mateus Gonçalves
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Mirza Muhammad Fahd Qadir
- Section of Endocrinology and Metabolism, John W. Deming Department of Medicine, Tulane University School of Medicine, New Orleans, LA, USA; Southeast Louisiana Veterans Health Care System, New Orleans, LA, USA; Tulane Center of Excellence in Sex-Based Biology & Medicine, New Orleans, LA, USA
| | - Maria Boulina
- Diabetes Research Institute, University of Miami, Miami, FL, USA
| | - Madina Makhmutova
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Elizabeth Pereira
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL, USA; Department of Physiology and Biophysics, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Joana Almaça
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL, USA; Department of Physiology and Biophysics, University of Miami Miller School of Medicine, Miami, FL, USA; Molecular and Cellular Pharmacology Graduate Program, University of Miami Miller School of Medicine, Miami, FL, USA.
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3
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Senfeld J, Peng Q, Shi Y, Qian S, Shen J. A purinergic mechanism underlying metformin regulation of hyperglycemia. iScience 2023; 26:106898. [PMID: 37378329 PMCID: PMC10291329 DOI: 10.1016/j.isci.2023.106898] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 03/01/2023] [Accepted: 05/12/2023] [Indexed: 06/29/2023] Open
Abstract
Metformin, created in 1922, has been the first-line therapy for treating type 2 diabetes mellitus for almost 70 years; however, its mechanism of action remains controversial, partly because most prior studies used supratherapeutic concentrations exceeding 1 mM despite therapeutical blood concentrations of metformin being less than 40 μM. Here we report metformin, at 10-30 μM, blocks high glucose-stimulated ATP secretion from hepatocytes mediating its antihyperglycemic action. Following glucose administration, mice demonstrate increased circulating ATP, which is prevented by metformin. Extracellular ATP through P2Y2 receptors (P2Y2R) suppresses PIP3 production, compromising insulin-induced AKT activation while promoting hepatic glucose production. Furthermore, metformin-dependent improvements in glucose tolerance are abolished in P2Y2R-null mice. Thus, removing the target of extracellular ATP, P2Y2R, mimics the effects of metformin, revealing a new purinergic antidiabetic mechanism for metformin. Besides unraveling long-standing questions in purinergic control of glucose homeostasis, our findings provide new insights into the pleiotropic actions of metformin.
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Affiliation(s)
- Jared Senfeld
- Department of Drug Discovery and Development, Harrison College of Pharmacy, Auburn University, Auburn, AL 36849, USA
| | - Qianman Peng
- Department of Drug Discovery and Development, Harrison College of Pharmacy, Auburn University, Auburn, AL 36849, USA
| | - Yi Shi
- Department of Drug Discovery and Development, Harrison College of Pharmacy, Auburn University, Auburn, AL 36849, USA
| | - Shenqi Qian
- Department of Drug Discovery and Development, Harrison College of Pharmacy, Auburn University, Auburn, AL 36849, USA
| | - Jianzhong Shen
- Department of Drug Discovery and Development, Harrison College of Pharmacy, Auburn University, Auburn, AL 36849, USA
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Xiao X, Luo Y, Peng D. Updated Understanding of the Crosstalk Between Glucose/Insulin and Cholesterol Metabolism. Front Cardiovasc Med 2022; 9:879355. [PMID: 35571202 PMCID: PMC9098828 DOI: 10.3389/fcvm.2022.879355] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2022] [Accepted: 04/07/2022] [Indexed: 12/19/2022] Open
Abstract
Glucose and cholesterol engage in almost all human physiological activities. As the primary energy substance, glucose can be assimilated and converted into diverse essential substances, including cholesterol. Cholesterol is mainly derived from de novo biosynthesis and the intestinal absorption of diets. It is evidenced that glucose/insulin promotes cholesterol biosynthesis and uptake, which have been targeted by several drugs for lipid-lowering, e.g., bempedoic acid, statins, ezetimibe, and proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors. Inversely, these lipid-lowering drugs may also interfere with glucose metabolism. This review would briefly summarize the mechanisms of glucose/insulin-stimulated cholesterol biosynthesis and uptake, and discuss the effect and mechanisms of lipid-lowering drugs and genetic mutations on glucose homeostasis, aiming to help better understand the intricate relationship between glucose and cholesterol metabolism.
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The Purinergic Landscape of Type 2 Diabetes Mellitus. Molecules 2022; 27:molecules27061838. [PMID: 35335211 PMCID: PMC8951306 DOI: 10.3390/molecules27061838] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 03/08/2022] [Accepted: 03/08/2022] [Indexed: 12/20/2022] Open
Abstract
Adenosine triphosphate (ATP) is the key energy intermediate of cellular metabolic processes and a ubiquitous extracellular messenger. As an extracellular messenger, ATP acts at plasma membrane P2 receptors (P2Rs). The levels of extracellular ATP (eATP) are set by both passive and active release mechanisms and degradation processes. Under physiological conditions, eATP concentration is in the low nanomolar range but can rise to tens or even hundreds of micromoles/L at inflammatory sites. A dysregulated eATP homeostasis is a pathogenic factor in several chronic inflammatory diseases, including type 2 diabetes mellitus (T2DM). T2DM is characterized by peripheral insulin resistance and impairment of insulin production from pancreatic β-cells in a landscape of systemic inflammation. Although various hypoglycemic drugs are currently available, an effective treatment for T2DM and its complications is not available. However, counteracting systemic inflammation is anticipated to be beneficial. The postulated eATP increase in T2DM is understood to be a driver of inflammation via P2X7 receptor (P2X7R) activation and the release of inflammatory cytokines. Furthermore, P2X7R stimulation is thought to trigger apoptosis of pancreatic β-cells, thus further aggravating hyperglycemia. Targeting eATP and the P2X7R might be an appealing novel approach to T2DM therapy.
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Lysosomal ATP Transporter SLC17A9 Controls Cell Viability via Regulating Cathepsin D. Cells 2022; 11:cells11050887. [PMID: 35269509 PMCID: PMC8909234 DOI: 10.3390/cells11050887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2021] [Revised: 02/26/2022] [Accepted: 02/28/2022] [Indexed: 12/04/2022] Open
Abstract
SLC17A9 (solute carrier family 17 member 9) functions as an ATP transporter in lysosomes as well as other secretory vesicles. SLC17A9 inhibition or silence leads to cell death. However, the molecular mechanisms causing cell death are unclear. In this study, we report that cell death induced by SLC17A9 deficiency is rescued by the transcription factor EB (TFEB), a master gene for lysosomal protein expression, suggesting that SLC17A9 deficiency may be the main cause of lysosome dysfunction, subsequently leading to cell death. Interestingly, Cathepsin D, a lysosomal aspartic protease, is inhibited by SLC17A9 deficiency. Heterologous expression of Cathepsin D successfully rescues lysosomal dysfunction and cell death induced by SLC17A9 deficiency. On the other hand, the activity of Cathepsin B, a lysosomal cysteine protease, is not altered by SLC17A9 deficiency, and Cathepsin B overexpression does not rescue lysosomal dysfunction and cell death induced by SLC17A9 deficiency. Our data suggest that lysosomal ATP and SLC17A9 play critical roles in lysosomal function and cell viability by regulating Cathepsin D activity.
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Pulukool SK, Srimadh Bhagavatham SK, Kannan V, Parim B, Challa S, Karnatam V, V.M DD, Ahmad Mir I, Sukumar P, Venkateshan V, Sharma A, Sivaramakrishnan V. Elevated ATP, cytokines and potential microglial inflammation distinguish exfoliation glaucoma from exfoliation syndrome. Cytokine 2022; 151:155807. [DOI: 10.1016/j.cyto.2022.155807] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Revised: 12/19/2021] [Accepted: 01/11/2022] [Indexed: 12/27/2022]
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Hasuzawa N, Moriyama S, Wang L, Nagayama A, Ashida K, Moriyama Y, Nomura M. Quinacrine is not a vital fluorescent probe for vesicular ATP storage. Purinergic Signal 2021; 17:725-735. [PMID: 34713379 DOI: 10.1007/s11302-021-09820-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 09/27/2021] [Indexed: 10/20/2022] Open
Abstract
Quinacrine, a fluorescent amphipathic amine, has been used as a vital fluorescent probe to visualize vesicular storage of ATP in the field of purinergic signaling. However, the mechanism(s) by which quinacrine represents vesicular ATP storage remains to be clarified. The present study investigated the validity of the use of quinacrine as a vial fluorescent probe for ATP-storing organelles. Vesicular nucleotide transporter (VNUT), an essential component for vesicular storage and ATP release, is present in very low density lipoprotein (VLDL)-containing secretory vesicles in hepatocytes. VNUT gene knockout (Vnut-/-) or clodronate treatment, a VNUT inhibitor, disappeared vesicular ATP release (Tatsushima et al., Biochim Biophys Acta Molecular Basis of Disease 2021, e166013). Upon incubation of mice's primary hepatocytes, quinacrine accumulates in a granular pattern into the cytoplasm, sensitive to 0.1-μM bafilomycin A1, a vacuolar ATPase (V-ATPase) inhibitor. Neither Vnut-/- nor treatment of clodronate affected quinacrine granular accumulation. In vitro, quinacrine is accumulated into liposomes upon imposing inside acidic transmembranous pH gradient (∆pH) irrespective of the presence or absence of ATP. Neither ATP binding on VNUT nor VNUT-mediated uptake of ATP was affected by quinacrine. Consistently, VNUT-mediated uptake of quinacrine was negligible or under the detection limit. From these results, it is concluded that vesicular quinacrine accumulation is not due to a consequence of its interaction with ATP but due to ∆pH-driven concentration across the membranes as an amphipathic amine. Thus, quinacrine is not a vital fluorescent probe for vesicular ATP storage.
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Affiliation(s)
- Nao Hasuzawa
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Kurume University School of Medicine, 67 Asahi-machi, Kurume, 830-0011, Japan
| | - Sawako Moriyama
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Kurume University School of Medicine, 67 Asahi-machi, Kurume, 830-0011, Japan
| | - Lixiang Wang
- Department of Medical Biochemistry, Kurume University School of Medicine, Kurume, 830-0011, Japan
| | - Ayako Nagayama
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Kurume University School of Medicine, 67 Asahi-machi, Kurume, 830-0011, Japan
| | - Kenji Ashida
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Kurume University School of Medicine, 67 Asahi-machi, Kurume, 830-0011, Japan
| | - Yoshinori Moriyama
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Kurume University School of Medicine, 67 Asahi-machi, Kurume, 830-0011, Japan.
| | - Masatoshi Nomura
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Kurume University School of Medicine, 67 Asahi-machi, Kurume, 830-0011, Japan
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Tsuchida K, Nakamura A, Miyoshi H, Yang K, Yamauchi Y, Kawata S, Omori K, Takahashi K, Kitao N, Nomoto H, Kameda H, Cho KY, Seino Y, Terauchi Y, Atsumi T. Glucokinase is required for high-starch diet-induced β-cell mass expansion in mice. J Diabetes Investig 2021; 12:1545-1554. [PMID: 33638884 PMCID: PMC8409809 DOI: 10.1111/jdi.13532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 01/27/2021] [Accepted: 02/14/2021] [Indexed: 11/19/2022] Open
Abstract
AIMS/INTRODUCTION We aimed to determine whether glucokinase is required for β-cell mass expansion induced by high-starch diet (HSTD)-feeding, as has been shown in its high-fat diet-induced expansion. MATERIALS AND METHODS Eight-week-old male wild-type (Gck+/+ ) or glucokinase haploinsufficient (Gck+/- ) mice were fed either a normal chow (NC) or an HSTD for 15 weeks. The bodyweight, glucose tolerance, insulin sensitivity, insulin secretion and β-cell mass were assessed. RESULTS Both HSTD-fed Gck+/+ and Gck+/- mice had significantly higher bodyweight than NC-fed mice. Insulin and oral glucose tolerance tests revealed that HSTD feeding did not affect insulin sensitivity nor glucose tolerance in either the Gck+/+ or Gck+/- mice. However, during the oral glucose tolerance test, the 15-min plasma insulin concentration after glucose loading was significantly higher in the HSTD group than that in the NC group for Gck+/+ , but not for Gck+/- mice. β-Cell mass was significantly larger in HSTD-fed Gck+/+ mice than that in NC-fed Gck+/+ mice. In contrast, the β-cell mass of the HSTD-fed Gck+/- mice was not different from that of the NC-fed Gck+/- mice. CONCLUSIONS The results showed that HSTD feeding would increase pancreatic β-cell mass and insulin secretion in Gck+/+ , but not Gck+/- mice. This observation implies that glucokinase in β-cells would be required for the increase in β-cell mass induced by HSTD feeding.
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Affiliation(s)
- Kazuhisa Tsuchida
- Department of Rheumatology, Endocrinology and NephrologyFaculty of Medicine and Graduate School of MedicineHokkaido UniversitySapporoJapan
| | - Akinobu Nakamura
- Department of Rheumatology, Endocrinology and NephrologyFaculty of Medicine and Graduate School of MedicineHokkaido UniversitySapporoJapan
| | - Hideaki Miyoshi
- Division of Diabetes and ObesityFaculty of Medicine and Graduate School of MedicineHokkaido UniversitySapporoJapan
| | - Kelaier Yang
- Department of Rheumatology, Endocrinology and NephrologyFaculty of Medicine and Graduate School of MedicineHokkaido UniversitySapporoJapan
| | - Yuki Yamauchi
- Department of Rheumatology, Endocrinology and NephrologyFaculty of Medicine and Graduate School of MedicineHokkaido UniversitySapporoJapan
| | - Shinichiro Kawata
- Department of Rheumatology, Endocrinology and NephrologyFaculty of Medicine and Graduate School of MedicineHokkaido UniversitySapporoJapan
| | - Kazuno Omori
- Department of Rheumatology, Endocrinology and NephrologyFaculty of Medicine and Graduate School of MedicineHokkaido UniversitySapporoJapan
| | - Kiyohiko Takahashi
- Department of Rheumatology, Endocrinology and NephrologyFaculty of Medicine and Graduate School of MedicineHokkaido UniversitySapporoJapan
| | - Naoyuki Kitao
- Department of Rheumatology, Endocrinology and NephrologyFaculty of Medicine and Graduate School of MedicineHokkaido UniversitySapporoJapan
| | - Hiroshi Nomoto
- Department of Rheumatology, Endocrinology and NephrologyFaculty of Medicine and Graduate School of MedicineHokkaido UniversitySapporoJapan
| | - Hiraku Kameda
- Department of Rheumatology, Endocrinology and NephrologyFaculty of Medicine and Graduate School of MedicineHokkaido UniversitySapporoJapan
| | - Kyu Yong Cho
- Department of Rheumatology, Endocrinology and NephrologyFaculty of Medicine and Graduate School of MedicineHokkaido UniversitySapporoJapan
- Clinical Research and Medical Innovation CenterHokkaido University HospitalSapporoJapan
| | - Yusuke Seino
- Department of Endocrinology and MetabolismGraduate School of MedicineFujita Health UniversityToyoakeJapan
| | - Yasuo Terauchi
- Department of Endocrinology and MetabolismGraduate School of MedicineYokohama City UniversityYokohamaJapan
| | - Tatsuya Atsumi
- Department of Rheumatology, Endocrinology and NephrologyFaculty of Medicine and Graduate School of MedicineHokkaido UniversitySapporoJapan
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Germanos M, Gao A, Taper M, Yau B, Kebede MA. Inside the Insulin Secretory Granule. Metabolites 2021; 11:metabo11080515. [PMID: 34436456 PMCID: PMC8401130 DOI: 10.3390/metabo11080515] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 08/03/2021] [Accepted: 08/03/2021] [Indexed: 12/19/2022] Open
Abstract
The pancreatic β-cell is purpose-built for the production and secretion of insulin, the only hormone that can remove glucose from the bloodstream. Insulin is kept inside miniature membrane-bound storage compartments known as secretory granules (SGs), and these specialized organelles can readily fuse with the plasma membrane upon cellular stimulation to release insulin. Insulin is synthesized in the endoplasmic reticulum (ER) as a biologically inactive precursor, proinsulin, along with several other proteins that will also become members of the insulin SG. Their coordinated synthesis enables synchronized transit through the ER and Golgi apparatus for congregation at the trans-Golgi network, the initiating site of SG biogenesis. Here, proinsulin and its constituents enter the SG where conditions are optimized for proinsulin processing into insulin and subsequent insulin storage. A healthy β-cell is continually generating SGs to supply insulin in vast excess to what is secreted. Conversely, in type 2 diabetes (T2D), the inability of failing β-cells to secrete may be due to the limited biosynthesis of new insulin. Factors that drive the formation and maturation of SGs and thus the production of insulin are therefore critical for systemic glucose control. Here, we detail the formative hours of the insulin SG from the luminal perspective. We do this by mapping the journey of individual members of the SG as they contribute to its genesis.
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Wu Z, Xu J, Liang C, Meng Q, Hua J, Wang W, Zhang B, Liu J, Yu X, Shi S. Emerging roles of the solute carrier family in pancreatic cancer. Clin Transl Med 2021; 11:e356. [PMID: 33783998 PMCID: PMC7989705 DOI: 10.1002/ctm2.356] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 02/25/2021] [Accepted: 03/01/2021] [Indexed: 02/06/2023] Open
Abstract
Pancreatic cancer is a gastrointestinal tumor with a high mortality rate, and advances in surgical procedures have only resulted in limited improvements in the prognosis of patients. Solute carriers (SLCs), which rank second among membrane transport proteins in terms of abundance, regulate cellular functions, including tumor biology. An increasing number of studies focusing on the role of SLCs in tumor biology have indicated their relationship with pancreatic cancer. The mechanism of SLC transporters in tumorigenesis has been explored to identify more effective therapies and improve survival outcomes. These transporters are significant biomarkers for pancreatic cancer, the functions of which include mainly proliferative signaling, cell death, angiogenesis, tumor invasion and metastasis, energy metabolism, chemotherapy sensitivity and other functions in tumor biology. In this review, we summarize the different roles of SLCs and explain their potential applications in pancreatic cancer treatment.
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Affiliation(s)
- Zijian Wu
- Department of Pancreatic SurgeryFudan University Shanghai Cancer CenterShanghaiChina
- Department of OncologyShanghai Medical CollegeFudan UniversityShanghaiChina
- Shanghai Pancreatic Cancer InstituteShanghaiChina
- Pancreatic Cancer InstituteFudan UniversityShanghaiChina
| | - Jin Xu
- Department of Pancreatic SurgeryFudan University Shanghai Cancer CenterShanghaiChina
- Department of OncologyShanghai Medical CollegeFudan UniversityShanghaiChina
- Shanghai Pancreatic Cancer InstituteShanghaiChina
- Pancreatic Cancer InstituteFudan UniversityShanghaiChina
| | - Chen Liang
- Department of Pancreatic SurgeryFudan University Shanghai Cancer CenterShanghaiChina
- Department of OncologyShanghai Medical CollegeFudan UniversityShanghaiChina
- Shanghai Pancreatic Cancer InstituteShanghaiChina
- Pancreatic Cancer InstituteFudan UniversityShanghaiChina
| | - Qingcai Meng
- Department of Pancreatic SurgeryFudan University Shanghai Cancer CenterShanghaiChina
- Department of OncologyShanghai Medical CollegeFudan UniversityShanghaiChina
- Shanghai Pancreatic Cancer InstituteShanghaiChina
- Pancreatic Cancer InstituteFudan UniversityShanghaiChina
| | - Jie Hua
- Department of Pancreatic SurgeryFudan University Shanghai Cancer CenterShanghaiChina
- Department of OncologyShanghai Medical CollegeFudan UniversityShanghaiChina
- Shanghai Pancreatic Cancer InstituteShanghaiChina
- Pancreatic Cancer InstituteFudan UniversityShanghaiChina
| | - Wei Wang
- Department of Pancreatic SurgeryFudan University Shanghai Cancer CenterShanghaiChina
- Department of OncologyShanghai Medical CollegeFudan UniversityShanghaiChina
- Shanghai Pancreatic Cancer InstituteShanghaiChina
- Pancreatic Cancer InstituteFudan UniversityShanghaiChina
| | - Bo Zhang
- Department of Pancreatic SurgeryFudan University Shanghai Cancer CenterShanghaiChina
- Department of OncologyShanghai Medical CollegeFudan UniversityShanghaiChina
- Shanghai Pancreatic Cancer InstituteShanghaiChina
- Pancreatic Cancer InstituteFudan UniversityShanghaiChina
| | - Jiang Liu
- Department of Pancreatic SurgeryFudan University Shanghai Cancer CenterShanghaiChina
- Department of OncologyShanghai Medical CollegeFudan UniversityShanghaiChina
- Shanghai Pancreatic Cancer InstituteShanghaiChina
- Pancreatic Cancer InstituteFudan UniversityShanghaiChina
| | - Xianjun Yu
- Department of Pancreatic SurgeryFudan University Shanghai Cancer CenterShanghaiChina
- Department of OncologyShanghai Medical CollegeFudan UniversityShanghaiChina
- Shanghai Pancreatic Cancer InstituteShanghaiChina
- Pancreatic Cancer InstituteFudan UniversityShanghaiChina
| | - Si Shi
- Department of Pancreatic SurgeryFudan University Shanghai Cancer CenterShanghaiChina
- Department of OncologyShanghai Medical CollegeFudan UniversityShanghaiChina
- Shanghai Pancreatic Cancer InstituteShanghaiChina
- Pancreatic Cancer InstituteFudan UniversityShanghaiChina
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12
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Bhat S, El-Kasaby A, Freissmuth M, Sucic S. Functional and Biochemical Consequences of Disease Variants in Neurotransmitter Transporters: A Special Emphasis on Folding and Trafficking Deficits. Pharmacol Ther 2020; 222:107785. [PMID: 33310157 PMCID: PMC7612411 DOI: 10.1016/j.pharmthera.2020.107785] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 12/02/2020] [Indexed: 01/30/2023]
Abstract
Neurotransmitters, such as γ-aminobutyric acid, glutamate, acetyl choline, glycine and the monoamines, facilitate the crosstalk within the central nervous system. The designated neurotransmitter transporters (NTTs) both release and take up neurotransmitters to and from the synaptic cleft. NTT dysfunction can lead to severe pathophysiological consequences, e.g. epilepsy, intellectual disability, or Parkinson’s disease. Genetic point mutations in NTTs have recently been associated with the onset of various neurological disorders. Some of these mutations trigger folding defects in the NTT proteins. Correct folding is a prerequisite for the export of NTTs from the endoplasmic reticulum (ER) and the subsequent trafficking to their pertinent site of action, typically at the plasma membrane. Recent studies have uncovered some of the key features in the molecular machinery responsible for transporter protein folding, e.g., the role of heat shock proteins in fine-tuning the ER quality control mechanisms in cells. The therapeutic significance of understanding these events is apparent from the rising number of reports, which directly link different pathological conditions to NTT misfolding. For instance, folding-deficient variants of the human transporters for dopamine or GABA lead to infantile parkinsonism/dystonia and epilepsy, respectively. From a therapeutic point of view, some folding-deficient NTTs are amenable to functional rescue by small molecules, known as chemical and pharmacological chaperones.
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Affiliation(s)
- Shreyas Bhat
- Institute of Pharmacology and the Gaston H. Glock Research Laboratories for Exploratory Drug Development, Center of Physiology and Pharmacology, Medical University of Vienna, A-1090 Vienna, Austria
| | - Ali El-Kasaby
- Institute of Pharmacology and the Gaston H. Glock Research Laboratories for Exploratory Drug Development, Center of Physiology and Pharmacology, Medical University of Vienna, A-1090 Vienna, Austria
| | - Michael Freissmuth
- Institute of Pharmacology and the Gaston H. Glock Research Laboratories for Exploratory Drug Development, Center of Physiology and Pharmacology, Medical University of Vienna, A-1090 Vienna, Austria
| | - Sonja Sucic
- Institute of Pharmacology and the Gaston H. Glock Research Laboratories for Exploratory Drug Development, Center of Physiology and Pharmacology, Medical University of Vienna, A-1090 Vienna, Austria.
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13
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Kreutzberger AJB, Kiessling V, Doyle CA, Schenk N, Upchurch CM, Elmer-Dixon M, Ward AE, Preobraschenski J, Hussein SS, Tomaka W, Seelheim P, Kattan I, Harris M, Liang B, Kenworthy AK, Desai BN, Leitinger N, Anantharam A, Castle JD, Tamm LK. Distinct insulin granule subpopulations implicated in the secretory pathology of diabetes types 1 and 2. eLife 2020; 9:e62506. [PMID: 33164744 PMCID: PMC7738183 DOI: 10.7554/elife.62506] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 11/06/2020] [Indexed: 12/12/2022] Open
Abstract
Insulin secretion from β-cells is reduced at the onset of type-1 and during type-2 diabetes. Although inflammation and metabolic dysfunction of β-cells elicit secretory defects associated with type-1 or type-2 diabetes, accompanying changes to insulin granules have not been established. To address this, we performed detailed functional analyses of insulin granules purified from cells subjected to model treatments that mimic type-1 and type-2 diabetic conditions and discovered striking shifts in calcium affinities and fusion characteristics. We show that this behavior is correlated with two subpopulations of insulin granules whose relative abundance is differentially shifted depending on diabetic model condition. The two types of granules have different release characteristics, distinct lipid and protein compositions, and package different secretory contents alongside insulin. This complexity of β-cell secretory physiology establishes a direct link between granule subpopulation and type of diabetes and leads to a revised model of secretory changes in the diabetogenic process.
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Affiliation(s)
- Alex J B Kreutzberger
- Center for Membrane and Cell Physiology, University of VirginiaCharlottesvilleUnited States
- Department for Molecular Physiology and Biological Physics, University of VirginiaCharlottesvilleUnited States
| | - Volker Kiessling
- Center for Membrane and Cell Physiology, University of VirginiaCharlottesvilleUnited States
- Department for Molecular Physiology and Biological Physics, University of VirginiaCharlottesvilleUnited States
| | - Catherine A Doyle
- Department of Pharmacology, University of VirginiaCharlottesvilleUnited States
| | - Noah Schenk
- Department of Pharmacology, University of MichiganAnn ArborUnited States
| | - Clint M Upchurch
- Department of Pharmacology, University of VirginiaCharlottesvilleUnited States
| | - Margaret Elmer-Dixon
- Center for Membrane and Cell Physiology, University of VirginiaCharlottesvilleUnited States
- Department for Molecular Physiology and Biological Physics, University of VirginiaCharlottesvilleUnited States
| | - Amanda E Ward
- Center for Membrane and Cell Physiology, University of VirginiaCharlottesvilleUnited States
- Department for Molecular Physiology and Biological Physics, University of VirginiaCharlottesvilleUnited States
| | - Julia Preobraschenski
- Department of Neurobiology, Max Planck Institute for Biophysical ChemistryGöttingenGermany
- Cluster of Excellence in Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells and Institute for Auditory Neuroscience, University of GöttingenGöttingenGermany
| | - Syed S Hussein
- Department of Microbiology, University of VirginiaCharlottesvilleUnited States
| | - Weronika Tomaka
- Center for Membrane and Cell Physiology, University of VirginiaCharlottesvilleUnited States
- Department for Molecular Physiology and Biological Physics, University of VirginiaCharlottesvilleUnited States
| | - Patrick Seelheim
- Center for Membrane and Cell Physiology, University of VirginiaCharlottesvilleUnited States
- Department for Molecular Physiology and Biological Physics, University of VirginiaCharlottesvilleUnited States
| | - Iman Kattan
- Department of Neurobiology, Max Planck Institute for Biophysical ChemistryGöttingenGermany
| | - Megan Harris
- Department of Cell Biology, University of VirginiaCharlottesvilleUnited States
| | - Binyong Liang
- Center for Membrane and Cell Physiology, University of VirginiaCharlottesvilleUnited States
- Department for Molecular Physiology and Biological Physics, University of VirginiaCharlottesvilleUnited States
| | - Anne K Kenworthy
- Center for Membrane and Cell Physiology, University of VirginiaCharlottesvilleUnited States
- Department for Molecular Physiology and Biological Physics, University of VirginiaCharlottesvilleUnited States
| | - Bimal N Desai
- Center for Membrane and Cell Physiology, University of VirginiaCharlottesvilleUnited States
- Department of Pharmacology, University of VirginiaCharlottesvilleUnited States
| | - Norbert Leitinger
- Department of Pharmacology, University of VirginiaCharlottesvilleUnited States
| | - Arun Anantharam
- Department of Pharmacology, University of MichiganAnn ArborUnited States
| | - J David Castle
- Center for Membrane and Cell Physiology, University of VirginiaCharlottesvilleUnited States
- Department of Cell Biology, University of VirginiaCharlottesvilleUnited States
| | - Lukas K Tamm
- Center for Membrane and Cell Physiology, University of VirginiaCharlottesvilleUnited States
- Department for Molecular Physiology and Biological Physics, University of VirginiaCharlottesvilleUnited States
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14
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Takata-Tsuji F, Chounlamountri N, Do LD, Philippot C, Novion Ducassou J, Couté Y, Ben Achour S, Honnorat J, Place C, Pascual O. Microglia modulate gliotransmission through the regulation of VAMP2 proteins in astrocytes. Glia 2020; 69:61-72. [PMID: 32633839 DOI: 10.1002/glia.23884] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Revised: 06/12/2020] [Accepted: 06/15/2020] [Indexed: 12/31/2022]
Abstract
Vesicular release is one of the release mechanisms of various signaling molecules. In neurons, the molecular machinery involved in vesicular release has been designed through evolution to trigger fast and synchronous release of neurotransmitters. Similar machinery with a slower kinetic and a slightly different molecular assembly allows astrocytes to release various transmitters such as adenosine triphosphate (ATP), glutamate, and D-serine. Astrocytes are important modulators of neurotransmission through gliotransmitter release. We recently demonstrated that microglia, another type of glia, release ATP to modulate synaptic transmission using astrocytes as intermediate. We now report that microglia regulate astrocytic gliotransmission through the regulation of SNARE proteins in astrocytes. Indeed, we found that gliotransmission triggered by P2Y1 agonist is impaired in slices from transgenic mice devoid of microglia. Using total internal reflection fluorescence imaging, we found that the vesicular release of gliotransmitter by astrocytes was different in cultures lacking microglia compared to vesicular release in astrocytes cocultured with microglia. Quantification of the kinetic of vesicular release indicates that the overall release appears to be faster in pure astrocyte cultures with more vesicles close to the membrane when compared to astrocytes cocultured with microglia. Finally, biochemical investigation of SNARE protein expression indicates an upregulation of VAMP2 in absence of microglia. Altogether, these results indicate that microglia seems to be involved in the regulation of an astrocytic phenotype compatible with proper gliotransmission. The mechanisms described in this study could be of importance for central nervous system diseases where microglia are activated.
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Affiliation(s)
- Fuyuko Takata-Tsuji
- INSERM U1217, CNRS UMR5310, Institut NeuroMyoGène, Lyon, France.,Université Claude Bernard Lyon 1 Lyon, Université de Lyon, Lyon, France.,Department of Pharmaceutical Care and Health Sciences, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan
| | - Naura Chounlamountri
- INSERM U1217, CNRS UMR5310, Institut NeuroMyoGène, Lyon, France.,Université Claude Bernard Lyon 1 Lyon, Université de Lyon, Lyon, France
| | - Le-Duy Do
- INSERM U1217, CNRS UMR5310, Institut NeuroMyoGène, Lyon, France.,Université Claude Bernard Lyon 1 Lyon, Université de Lyon, Lyon, France
| | - Camille Philippot
- INSERM U1217, CNRS UMR5310, Institut NeuroMyoGène, Lyon, France.,Université Claude Bernard Lyon 1 Lyon, Université de Lyon, Lyon, France
| | | | - Yohann Couté
- Université Grenoble Alpes, CEA, INSERM, IRIG, BGE, Grenoble, France
| | - Sarrah Ben Achour
- Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, Université PSL, CNRS, INSERM, Paris, France
| | - Jérôme Honnorat
- INSERM U1217, CNRS UMR5310, Institut NeuroMyoGène, Lyon, France.,Université Claude Bernard Lyon 1 Lyon, Université de Lyon, Lyon, France.,Centre maladies rares sur les syndromes neurologiques paranéoplasiques, hospices Civils de Lyon, Lyon, France
| | - Christophe Place
- ENS de Lyon, CNRS, Laboratoire de Physique, Université de Lyon, Lyon, France
| | - Olivier Pascual
- INSERM U1217, CNRS UMR5310, Institut NeuroMyoGène, Lyon, France.,Université Claude Bernard Lyon 1 Lyon, Université de Lyon, Lyon, France
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15
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Statin Treatment-Induced Development of Type 2 Diabetes: From Clinical Evidence to Mechanistic Insights. Int J Mol Sci 2020; 21:ijms21134725. [PMID: 32630698 PMCID: PMC7369709 DOI: 10.3390/ijms21134725] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 06/29/2020] [Accepted: 06/30/2020] [Indexed: 12/17/2022] Open
Abstract
Statins are the gold-standard treatment for the prevention of primary and secondary cardiovascular disease, which is the leading cause of mortality worldwide. Despite the safety and relative tolerability of statins, observational studies, clinical trials and meta-analyses indicate an increased risk of developing new-onset type 2 diabetes mellitus (T2DM) after long-term statin treatment. It has been shown that statins can impair insulin sensitivity and secretion by pancreatic β-cells and increase insulin resistance in peripheral tissues. The mechanisms involved in these processes include, among others, impaired Ca2+ signaling in pancreatic β-cells, down-regulation of GLUT-4 in adipocytes and compromised insulin signaling. In addition, it has also been described that statins’ impact on epigenetics may also contribute to statin-induced T2DM via differential expression of microRNAs. This review focuses on the evidence and mechanisms by which statin therapy is associated with the development of T2DM. This review describes the multifactorial combination of effects that most likely contributes to the diabetogenic effects of statins. Clinically, these findings should encourage clinicians to consider diabetes monitoring in patients receiving statin therapy in order to ensure early diagnosis and appropriate management.
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16
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Fluorescent Labeling and Quantification of Vesicular ATP Release Using Live Cell Imaging. Methods Mol Biol 2020; 2041:209-221. [PMID: 31646491 DOI: 10.1007/978-1-4939-9717-6_15] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Adenosine triphosphate (ATP) is actively transported into vesicles for purinergic neurotransmission by the vesicular nucleotide transporter, VNUT, encoded by the gene, solute carrier 17, member 9 (SLC17A9). In this chapter, methods are described for fluorescent labeling of VNUT positive cells and quantification of vesicular ATP release using live cell imaging. Directions for preparation of viable dissociated neurons and cellular labeling with an antibody against VNUT and for ATP containing synaptic vesicles with fluorescent ATP markers, quinacrine or MANT-ATP, are detailed. Using confocal microscope live cell imaging, cells positive for VNUT can be observed colocalized with fluorescent ATP vesicular markers, which occur as discrete puncta near the cell membrane. Vesicular release, stimulated with a depolarizing, high potassium physiological saline solution induces ATP marker fluorescence reduction at the cell membrane and this can be quantified over time to assess ATP release. Pretreatment with the voltage gated calcium channel blocker, cadmium, blocks depolarization-induced membrane fluorescence changes, suggesting that VNUT-positive neurons release ATP via calcium-dependent exocytosis. This technique may be applied for quantifying vesicular ATP release across the peripheral and central nervous system and is useful for unveiling the intricacies of purinergic neurotransmission.
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17
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Wei L, Mousawi F, Li D, Roger S, Li J, Yang X, Jiang LH. Adenosine Triphosphate Release and P2 Receptor Signaling in Piezo1 Channel-Dependent Mechanoregulation. Front Pharmacol 2019; 10:1304. [PMID: 31780935 PMCID: PMC6853025 DOI: 10.3389/fphar.2019.01304] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Accepted: 10/15/2019] [Indexed: 12/16/2022] Open
Abstract
Organs and tissues and their constituent cells are physiologically submitted to diverse types of mechanical forces or stress, one common sequence of which is release of intracellular ATP into extracellular space. Extracellular ATP is a well-established autocrine or paracrine signaling molecule that regulates multiple cell functions and mediates cell-to-cell communications via activating the purinergic P2 receptors, more specifically, ligand-gated ion channel P2X receptors and some of the G-protein-coupled P2Y receptors. The molecular mechanisms that sense mechanical and transduce forces to trigger ATP release are poorly understood. The Piezo1, a newly identified mechanosensing ion channel, shows widespread expression and confers mechanosensitivity in many different types of cells. In this mini-review, we briefly introduce the Piezo1 channel and discuss the evidence that supports its important role in the mechanoregulation of diverse cell functions and, more specifically, critical engagement of ATP release and subsequent P2 receptor activation in Piezo1 channel-dependent mechanoregulation. Such ATP release-mediated coupling of the Piezo1 channel and P2 receptors may serve a signaling mechanism that is more common than we currently understand in transducing mechanical information to regulation of the attendant cell functions in various organs and tissues.
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Affiliation(s)
- Linyu Wei
- Sino-UK Joint Laboratory of Brain Function and Injury and Department of Physiology and Neurobiology, Xinxiang Medical University, Xinxiang, China
| | - Fatema Mousawi
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - Dongliang Li
- Department of Physiology, Sanquan College of Xinxiang Medical University, Xinxiang, China
| | - Sébastien Roger
- EA4245, Transplantation, Immunology and Inflammation, Faculty of Medicine, University of Tours, Tours, France
| | - Jing Li
- Lingnan Medical Research Centre, School of Medicine, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Xuebin Yang
- Department of Oral Biology, Faculty of Medicine and Health, University of Leeds, Leeds, United Kingdom
| | - Lin-Hua Jiang
- Sino-UK Joint Laboratory of Brain Function and Injury and Department of Physiology and Neurobiology, Xinxiang Medical University, Xinxiang, China
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
- EA4245, Transplantation, Immunology and Inflammation, Faculty of Medicine, University of Tours, Tours, France
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18
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Yin Y, Hong J, Phạm TL, Shin J, Gwon DH, Kwon HH, Shin N, Shin HJ, Lee SY, Lee WH, Kim DW. Evans Blue Reduces Neuropathic Pain Behavior by Inhibiting Spinal ATP Release. Int J Mol Sci 2019; 20:ijms20184443. [PMID: 31505901 PMCID: PMC6770806 DOI: 10.3390/ijms20184443] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 08/19/2019] [Accepted: 09/05/2019] [Indexed: 12/21/2022] Open
Abstract
Upon peripheral nerve injury, vesicular ATP is released from damaged primary afferent neurons. This extracellular ATP subsequently activates purinergic receptors of the spinal cord, which play a critical role in neuropathic pain. As an inhibitor of the vesicular nucleotide transporter (VNUT), Evans blue (EB) inhibits the vesicular storage and release of ATP in neurons. Thus, we tested whether EB could attenuate neuropathic pain behavior induced by spinal nerve ligation (SNL) in rats by targeting VNUT. An intrathecal injection of EB efficiently attenuated mechanical allodynia for five days in a dose-dependent manner and enhanced locomotive activity in an SNL rat model. Immunohistochemical analysis showed that EB was found in VNUT immunoreactivity on neurons in the dorsal root ganglion and the spinal dorsal horn. The level of ATP in cerebrospinal fluid in rats with SNL-induced neuropathic pain decreased upon administration of EB. Interestingly, EB blocked ATP release from neurons, but not glial cells in vitro. Eventually, the loss of ATP decreased microglial activity in the ipsilateral dorsal horn of the spinal cord, followed by a reduction in reactive oxygen species and proinflammatory mediators, such as interleukin (IL)-1β and IL-6. Finally, a similar analgesic effect of EB was demonstrated in rats with monoiodoacetate-induced osteoarthritis (OA) pain. Taken together, these data demonstrate that EB prevents ATP release in the spinal dorsal horn and reduces the ATP/purinergic receptor-induced activation of spinal microglia followed by a decline in algogenic substances, thereby relieving neuropathic pain in rats with SNL.
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Affiliation(s)
- Yuhua Yin
- Department of Medical Science, Chungnam National University School of Medicine, Daejeon 35015, Korea.
- Department of Anesthesiology and Pain Medicine, Chungnam National University Hospital, Daejeon 35015, Korea.
| | - Jinpyo Hong
- Department of Anatomy, Brain Research Institute, Chungnam National University School of Medicine, Daejeon 35015, Korea.
| | - Thuỳ Linh Phạm
- Department of Medical Science, Chungnam National University School of Medicine, Daejeon 35015, Korea.
| | - Juhee Shin
- Department of Medical Science, Chungnam National University School of Medicine, Daejeon 35015, Korea.
| | - Do Hyeong Gwon
- Department of Medical Science, Chungnam National University School of Medicine, Daejeon 35015, Korea.
| | - Hyeok Hee Kwon
- Department of Medical Science, Chungnam National University School of Medicine, Daejeon 35015, Korea.
| | - Nara Shin
- Department of Medical Science, Chungnam National University School of Medicine, Daejeon 35015, Korea.
| | - Hyo Jung Shin
- Department of Medical Science, Chungnam National University School of Medicine, Daejeon 35015, Korea.
| | - Sun Yeul Lee
- Department of Anesthesiology and Pain Medicine, Chungnam National University Hospital, Daejeon 35015, Korea.
| | - Won-Hyung Lee
- Department of Anesthesiology and Pain Medicine, Chungnam National University Hospital, Daejeon 35015, Korea.
| | - Dong Woon Kim
- Department of Medical Science, Chungnam National University School of Medicine, Daejeon 35015, Korea.
- Department of Anatomy, Brain Research Institute, Chungnam National University School of Medicine, Daejeon 35015, Korea.
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19
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Mederos S, Hernández-Vivanco A, Ramírez-Franco J, Martín-Fernández M, Navarrete M, Yang A, Boyden ES, Perea G. Melanopsin for precise optogenetic activation of astrocyte-neuron networks. Glia 2019; 67:915-934. [PMID: 30632636 DOI: 10.1002/glia.23580] [Citation(s) in RCA: 74] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 11/28/2018] [Accepted: 11/30/2018] [Indexed: 12/11/2022]
Abstract
Optogenetics has been widely expanded to enhance or suppress neuronal activity and it has been recently applied to glial cells. Here, we have used a new approach based on selective expression of melanopsin, a G-protein-coupled photopigment, in astrocytes to trigger Ca2+ signaling. Using the genetically encoded Ca2+ indicator GCaMP6f and two-photon imaging, we show that melanopsin is both competent to stimulate robust IP3-dependent Ca2+ signals in astrocyte fine processes, and to evoke an ATP/Adenosine-dependent transient boost of hippocampal excitatory synaptic transmission. Additionally, under low-frequency light stimulation conditions, melanopsin-transfected astrocytes can trigger long-term synaptic changes. In vivo, melanopsin-astrocyte activation enhances episodic-like memory, suggesting melanopsin as an optical tool that could recapitulate the wide range of regulatory actions of astrocytes on neuronal networks in behaving animals. These results describe a novel approach using melanopsin as a precise trigger for astrocytes that mimics their endogenous G-protein signaling pathways, and present melanopsin as a valuable optical tool for neuron-glia studies.
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Affiliation(s)
- Sara Mederos
- Department of Functional and Systems Neurobiology, Instituto Cajal, CSIC, Madrid, Spain
| | | | - Jorge Ramírez-Franco
- Department of Functional and Systems Neurobiology, Instituto Cajal, CSIC, Madrid, Spain
| | | | - Marta Navarrete
- Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Madrid, Spain
| | - Aimei Yang
- Media Lab, Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - Edward S Boyden
- Media Lab, Massachusetts Institute of Technology, Cambridge, Massachusetts.,McGovern Institute, Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - Gertrudis Perea
- Department of Functional and Systems Neurobiology, Instituto Cajal, CSIC, Madrid, Spain
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20
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Tezza S, Ben Nasr M, D'Addio F, Vergani A, Usuelli V, Falzoni S, Bassi R, Dellepiane S, Fotino C, Rossi C, Maestroni A, Solini A, Corradi D, Giani E, Mameli C, Bertuzzi F, Pezzolesi MG, Wasserfall CH, Atkinson MA, Füchtbauer EM, Ricordi C, Folli F, Di Virgilio F, Pileggi A, Dhe-Paganon S, Zuccotti GV, Fiorina P. Islet-Derived eATP Fuels Autoreactive CD8 + T Cells and Facilitates the Onset of Type 1 Diabetes. Diabetes 2018; 67:2038-2053. [PMID: 30065030 PMCID: PMC6905486 DOI: 10.2337/db17-1227] [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: 10/11/2017] [Accepted: 07/06/2018] [Indexed: 01/13/2023]
Abstract
Extracellular ATP (eATP) activates T cells by engaging the P2X7R receptor. We identified two loss-of-function P2X7R mutations that are protective against type 1 diabetes (T1D) and thus hypothesized that eATP/P2X7R signaling may represent an early step in T1D onset. Specifically, we observed that in patients with newly diagnosed T1D, P2X7R is upregulated on CD8+ effector T cells in comparison with healthy control subjects. eATP is released at high levels by human/murine islets in vitro in high-glucose/inflammatory conditions, thus upregulating P2X7R on CD8+ T cells in vitro. P2X7R blockade with oxidized ATP reduces the CD8+ T cell-mediated autoimmune response in vitro and delays diabetes onset in NOD mice. Autoreactive CD8+ T-cell activation is highly dependent upon eATP/P2X7R-mediated priming, while a novel sP2X7R recombinant protein abrogates changes in metabolism and the autoimmune response associated with CD8+ T cells. eATP/P2X7R signaling facilitates the onset of autoimmune T1D by fueling autoreactive CD8+ cells and therefore represents a novel targeted therapeutic for the disorder.
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Affiliation(s)
- Sara Tezza
- Division of Nephrology, Boston Children's Hospital, Harvard Medical School, Boston, MA
| | - Moufida Ben Nasr
- Division of Nephrology, Boston Children's Hospital, Harvard Medical School, Boston, MA
- International Center for Type 1 Diabetes, Pediatric Clinical Romeo and Enrica Invernizzi Research Center, and L. Sacco Department of Biomedical and Clinical Science, University of Milan, Milan, Italy
| | - Francesca D'Addio
- Division of Nephrology, Boston Children's Hospital, Harvard Medical School, Boston, MA
- International Center for Type 1 Diabetes, Pediatric Clinical Romeo and Enrica Invernizzi Research Center, and L. Sacco Department of Biomedical and Clinical Science, University of Milan, Milan, Italy
| | - Andrea Vergani
- Division of Nephrology, Boston Children's Hospital, Harvard Medical School, Boston, MA
| | - Vera Usuelli
- Division of Nephrology, Boston Children's Hospital, Harvard Medical School, Boston, MA
- International Center for Type 1 Diabetes, Pediatric Clinical Romeo and Enrica Invernizzi Research Center, and L. Sacco Department of Biomedical and Clinical Science, University of Milan, Milan, Italy
| | - Simonetta Falzoni
- Department of Morphology, Surgery and Experimental Medicine, University of Ferrara, Ferrara, Italy
| | - Roberto Bassi
- Division of Nephrology, Boston Children's Hospital, Harvard Medical School, Boston, MA
| | - Sergio Dellepiane
- Division of Nephrology, Boston Children's Hospital, Harvard Medical School, Boston, MA
| | - Carmen Fotino
- Diabetes Research Institute, University of Miami, FL
| | - Chiara Rossi
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Anna Maestroni
- International Center for Type 1 Diabetes, Pediatric Clinical Romeo and Enrica Invernizzi Research Center, and L. Sacco Department of Biomedical and Clinical Science, University of Milan, Milan, Italy
| | - Anna Solini
- Department of Surgical, Medical and Molecular Pathology and Critical Care Medicine, University of Pisa, Pisa, Italy
| | - Domenico Corradi
- Pathology and Laboratory Medicine, University of Parma, Parma, Italy
| | - Elisa Giani
- Pediatric Clinical Romeo and Enrica Invernizzi Research Center, L. Sacco Department of Biomedical and Clinical Science, University of Milan, and Department of Pediatrics, Children's Hospital Buzzi, Milan, Italy
| | - Chiara Mameli
- Pediatric Clinical Romeo and Enrica Invernizzi Research Center, L. Sacco Department of Biomedical and Clinical Science, University of Milan, and Department of Pediatrics, Children's Hospital Buzzi, Milan, Italy
| | - Federico Bertuzzi
- Diabetology Unit, ASST Grande Ospedale Metropolitano Niguarda, Milan, Italy
| | - Marcus G Pezzolesi
- Division of Nephrology & Hypertension and Diabetes & Metabolism Research Center, University of Utah, Salt Lake City, UT
| | - Clive H Wasserfall
- Department of Pathology, Immunology and Laboratory Medicine, University of Florida, Gainesville, FL
| | - Mark A Atkinson
- Department of Pathology, Immunology and Laboratory Medicine, University of Florida, Gainesville, FL
| | | | | | - Franco Folli
- Endocrinology and Metabolism, Department of Health Science, University of Milan, Milan, Italy
- ASST Santi Paolo e Carlo, Ospedali San Paolo e San Carlo Borromeo, Milan, Italy
| | - Francesco Di Virgilio
- Department of Morphology, Surgery and Experimental Medicine, University of Ferrara, Ferrara, Italy
| | | | | | - Gian Vincenzo Zuccotti
- International Center for Type 1 Diabetes, Pediatric Clinical Romeo and Enrica Invernizzi Research Center, and L. Sacco Department of Biomedical and Clinical Science, University of Milan, Milan, Italy
- Pediatric Clinical Romeo and Enrica Invernizzi Research Center, L. Sacco Department of Biomedical and Clinical Science, University of Milan, and Department of Pediatrics, Children's Hospital Buzzi, Milan, Italy
| | - Paolo Fiorina
- Division of Nephrology, Boston Children's Hospital, Harvard Medical School, Boston, MA
- International Center for Type 1 Diabetes, Pediatric Clinical Romeo and Enrica Invernizzi Research Center, and L. Sacco Department of Biomedical and Clinical Science, University of Milan, Milan, Italy
- Division of Endocrinology, ASST Fatebenefratelli-Sacco, Milan, Italy
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21
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Tozzi M, Larsen AT, Lange SC, Giannuzzo A, Andersen MN, Novak I. The P2X7 receptor and pannexin-1 are involved in glucose-induced autocrine regulation in β-cells. Sci Rep 2018; 8:8926. [PMID: 29895988 PMCID: PMC5997690 DOI: 10.1038/s41598-018-27281-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 05/31/2018] [Indexed: 01/02/2023] Open
Abstract
Extracellular ATP is an important short-range signaling molecule that promotes various physiological responses virtually in all cell types, including pancreatic β-cells. It is well documented that pancreatic β-cells release ATP through exocytosis of insulin granules upon glucose stimulation. We hypothesized that glucose might stimulate ATP release through other non-vesicular mechanisms. Several purinergic receptors are found in β-cells and there is increasing evidence that purinergic signaling regulates β-cell functions and survival. One of the receptors that may be relevant is the P2X7 receptor, but its detailed role in β-cell physiology is unclear. In this study we investigated roles of the P2X7 receptor and pannexin-1 in ATP release, intracellular ATP, Ca2+ signals, insulin release and cell proliferation/survival in β-cells. Results show that glucose induces rapid release of ATP and significant fraction of release involves the P2X7 receptor and pannexin-1, both expressed in INS-1E cells, rat and mouse β-cells. Furthermore, we provide pharmacological evidence that extracellular ATP, via P2X7 receptor, stimulates Ca2+ transients and cell proliferation in INS-1E cells and insulin secretion in INS-1E cells and rat islets. These data indicate that the P2X7 receptor and pannexin-1 have important functions in β-cell physiology, and should be considered in understanding and treatment of diabetes.
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Affiliation(s)
- Marco Tozzi
- Section for Cell Biology and Physiology, August Krogh Building, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Anna T Larsen
- Section for Cell Biology and Physiology, August Krogh Building, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Sofie C Lange
- Section for Cell Biology and Physiology, August Krogh Building, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Andrea Giannuzzo
- Section for Cell Biology and Physiology, August Krogh Building, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Martin N Andersen
- Section for Cell Biology and Physiology, August Krogh Building, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Ivana Novak
- Section for Cell Biology and Physiology, August Krogh Building, Department of Biology, University of Copenhagen, Copenhagen, Denmark.
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22
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Novak I, Solini A. P2X receptor-ion channels in the inflammatory response in adipose tissue and pancreas — potential triggers in onset of type 2 diabetes? Curr Opin Immunol 2018. [DOI: 10.1016/j.coi.2018.02.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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23
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Almaça J, Weitz J, Rodriguez-Diaz R, Pereira E, Caicedo A. The Pericyte of the Pancreatic Islet Regulates Capillary Diameter and Local Blood Flow. Cell Metab 2018; 27:630-644.e4. [PMID: 29514070 PMCID: PMC5876933 DOI: 10.1016/j.cmet.2018.02.016] [Citation(s) in RCA: 108] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Revised: 12/15/2017] [Accepted: 02/15/2018] [Indexed: 12/20/2022]
Abstract
Efficient insulin secretion requires a well-functioning pancreatic islet microvasculature. The dense network of islet capillaries includes the islet pericyte, a cell that has barely been studied. Here we show that islet pericytes help control local blood flow by adjusting islet capillary diameter. Islet pericytes cover 40% of the microvasculature, are contractile, and are innervated by sympathetic axons. Sympathetic adrenergic input increases pericyte activity and reduces capillary diameter and local blood flow. By contrast, activating beta cells by increasing glucose concentration inhibits pericytes, dilates islet capillaries, and increases local blood flow. These effects on pericytes are mediated by endogenous adenosine, which is likely derived from ATP co-released with insulin. Pericyte coverage of islet capillaries drops drastically in type 2 diabetes, suggesting that, under diabetic conditions, islets lose this mechanism to control their own blood supply. This may lead to inadequate insulin release into the circulation, further deteriorating glycemic control.
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Affiliation(s)
- Joana Almaça
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL 33136, USA.
| | - Jonathan Weitz
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL 33136, USA; Molecular Cell and Developmental Biology Program, Miller School of Medicine, University of Miami, Miami, FL 33136, USA
| | - Rayner Rodriguez-Diaz
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Elizabeth Pereira
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL 33136, USA; Department of Physiology and Biophysics, Miller School of Medicine, University of Miami, Miami, FL 33136, USA
| | - Alejandro Caicedo
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL 33136, USA; Department of Physiology and Biophysics, Miller School of Medicine, University of Miami, Miami, FL 33136, USA; Program in Neuroscience, Miller School of Medicine, University of Miami, Miami, FL 33136, USA.
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24
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Weitz JR, Makhmutova M, Almaça J, Stertmann J, Aamodt K, Brissova M, Speier S, Rodriguez-Diaz R, Caicedo A. Mouse pancreatic islet macrophages use locally released ATP to monitor beta cell activity. Diabetologia 2018; 61:182-192. [PMID: 28884198 PMCID: PMC5868749 DOI: 10.1007/s00125-017-4416-y] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Accepted: 07/14/2017] [Indexed: 12/19/2022]
Abstract
AIMS/HYPOTHESIS Tissue-resident macrophages sense the microenvironment and respond by producing signals that act locally to maintain a stable tissue state. It is now known that pancreatic islets contain their own unique resident macrophages, which have been shown to promote proliferation of the insulin-secreting beta cell. However, it is unclear how beta cells communicate with islet-resident macrophages. Here we hypothesised that islet macrophages sense changes in islet activity by detecting signals derived from beta cells. METHODS To investigate how islet-resident macrophages respond to cues from the microenvironment, we generated mice expressing a genetically encoded Ca2+ indicator in myeloid cells. We produced living pancreatic slices from these mice and used them to monitor macrophage responses to stimulation of acinar, neural and endocrine cells. RESULTS Islet-resident macrophages expressed functional purinergic receptors, making them exquisite sensors of interstitial ATP levels. Indeed, islet-resident macrophages responded selectively to ATP released locally from beta cells that were physiologically activated with high levels of glucose. Because ATP is co-released with insulin and is exclusively secreted by beta cells, the activation of purinergic receptors on resident macrophages facilitates their awareness of beta cell secretory activity. CONCLUSIONS/INTERPRETATION Our results indicate that islet macrophages detect ATP as a proxy signal for the activation state of beta cells. Sensing beta cell activity may allow macrophages to adjust the secretion of factors to promote a stable islet composition and size.
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Affiliation(s)
- Jonathan R Weitz
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Miami Miller School of Medicine, 1580 NW 10th Ave, Miami, FL, 33136, USA
- Molecular Cell and Developmental Biology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Madina Makhmutova
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Miami Miller School of Medicine, 1580 NW 10th Ave, Miami, FL, 33136, USA
- Program in Neuroscience, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Joana Almaça
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Miami Miller School of Medicine, 1580 NW 10th Ave, Miami, FL, 33136, USA
| | - Julia Stertmann
- Paul Langerhans Institute Dresden (PLID) of Helmholtz Center Munich at the University Clinic Carl Gustav Carus of Technische Universität Dresden, Helmholtz Zentrum München, Neuherberg, Germany
- DFG-Center for Regenerative Therapies Dresden (CRTD), Faculty of Medicine, Technische Universität Dresden, Dresden, Germany
- German Center for Diabetes Research (DZD), München-Neuherberg, Germany
| | - Kristie Aamodt
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Marcela Brissova
- Division of Diabetes, Endocrinology, and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Stephan Speier
- Paul Langerhans Institute Dresden (PLID) of Helmholtz Center Munich at the University Clinic Carl Gustav Carus of Technische Universität Dresden, Helmholtz Zentrum München, Neuherberg, Germany
- DFG-Center for Regenerative Therapies Dresden (CRTD), Faculty of Medicine, Technische Universität Dresden, Dresden, Germany
- German Center for Diabetes Research (DZD), München-Neuherberg, Germany
| | - Rayner Rodriguez-Diaz
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Miami Miller School of Medicine, 1580 NW 10th Ave, Miami, FL, 33136, USA.
| | - Alejandro Caicedo
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Miami Miller School of Medicine, 1580 NW 10th Ave, Miami, FL, 33136, USA.
- Molecular Cell and Developmental Biology, University of Miami Miller School of Medicine, Miami, FL, USA.
- Program in Neuroscience, University of Miami Miller School of Medicine, Miami, FL, USA.
- Department of Physiology and Biophysics, Miller School of Medicine, University of Miami, Miami, FL, USA.
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25
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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: 443] [Impact Index Per Article: 73.8] [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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26
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Fois G, Winkelmann VE, Bareis L, Staudenmaier L, Hecht E, Ziller C, Ehinger K, Schymeinsky J, Kranz C, Frick M. ATP is stored in lamellar bodies to activate vesicular P2X 4 in an autocrine fashion upon exocytosis. J Gen Physiol 2017; 150:277-291. [PMID: 29282210 PMCID: PMC5806682 DOI: 10.1085/jgp.201711870] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Revised: 10/12/2017] [Accepted: 11/17/2017] [Indexed: 12/14/2022] Open
Abstract
P2X4 receptor activation facilitates secretion of pulmonary surfactant from secretory vesicles called lamellar bodies in alveolar epithelial cells. Fois et al. reveal that P2X4 receptors on the lamellar body membranes are activated by ATP stored within the vesicles themselves upon vesicle exocytosis. Vesicular P2X4 receptors are known to facilitate secretion and activation of pulmonary surfactant in the alveoli of the lungs. P2X4 receptors are expressed in the membrane of lamellar bodies (LBs), large secretory lysosomes that store lung surfactant in alveolar type II epithelial cells, and become inserted into the plasma membrane after exocytosis. Subsequent activation of P2X4 receptors by adenosine triphosphate (ATP) results in local fusion-activated cation entry (FACE), facilitating fusion pore dilation, surfactant secretion, and surfactant activation. Despite the importance of ATP in the alveoli, and hence lung function, the origin of ATP in the alveoli is still elusive. In this study, we demonstrate that ATP is stored within LBs themselves at a concentration of ∼1.9 mM. ATP is loaded into LBs by the vesicular nucleotide transporter but does not activate P2X4 receptors because of the low intraluminal pH (5.5). However, the rise in intravesicular pH after opening of the exocytic fusion pore results in immediate activation of vesicular P2X4 by vesicular ATP. Our data suggest a new model in which agonist (ATP) and receptor (P2X4) are located in the same intracellular compartment (LB), protected from premature degradation (ATP) and activation (P2X4), and ideally placed to ensure coordinated and timely receptor activation as soon as fusion occurs to facilitate surfactant secretion.
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Affiliation(s)
- Giorgio Fois
- Institute of General Physiology, Ulm University, Ulm, Germany
| | | | - Lara Bareis
- Institute of General Physiology, Ulm University, Ulm, Germany
| | | | - Elena Hecht
- Institute of General Physiology, Ulm University, Ulm, Germany
| | - Charlotte Ziller
- Institute of Analytical and Bioanalytical Chemistry, Ulm University, Ulm, Germany
| | | | - Jürgen Schymeinsky
- Immunology and Respiratory Research, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riß, Germany
| | - Christine Kranz
- Institute of Analytical and Bioanalytical Chemistry, Ulm University, Ulm, Germany
| | - Manfred Frick
- Institute of General Physiology, Ulm University, Ulm, Germany
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27
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Vesicular nucleotide transporter (VNUT): appearance of an actress on the stage of purinergic signaling. Purinergic Signal 2017; 13:387-404. [PMID: 28616712 DOI: 10.1007/s11302-017-9568-1] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 05/05/2017] [Indexed: 12/17/2022] Open
Abstract
Vesicular storage of ATP is one of the processes initiating purinergic chemical transmission. Although an active transport mechanism was postulated to be involved in the processes, a transporter(s) responsible for the vesicular storage of ATP remained unidentified for some time. In 2008, SLC17A9, the last identified member of the solute carrier 17 type I inorganic phosphate transporter family, was found to encode the vesicular nucleotide transporter (VNUT) that is responsible for the vesicular storage of ATP. VNUT transports various nucleotides in a membrane potential-dependent fashion and is expressed in the various ATP-secreting cells. Mice with knockout of the VNUT gene lose vesicular storage and release of ATP from neurons and neuroendocrine cells, resulting in blockage of the initiation of purinergic chemical transmission. Thus, VNUT plays an essential role in the vesicular storage and release of ATP. The VNUT knockout mice exhibit resistance for neuropathic pain and a therapeutic effect against diabetes by way of increased insulin sensitivity. Thus, VNUT inhibitors and suppression of VNUT gene expression may be used for therapeutic purposes through suppression of purinergic chemical transmission. This review summarizes the studies to date on VNUT and discusses what we have learned about the relevance of vesicular ATP release as a potential drug target.
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28
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Guo D, Liu H, Ruzi A, Gao G, Nasir A, Liu Y, Yang F, Wu F, Xu G, Li YX. Modeling Congenital Hyperinsulinism with ABCC8-Deficient Human Embryonic Stem Cells Generated by CRISPR/Cas9. Sci Rep 2017; 7:3156. [PMID: 28600547 PMCID: PMC5466656 DOI: 10.1038/s41598-017-03349-w] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Accepted: 04/27/2017] [Indexed: 02/08/2023] Open
Abstract
Congenital hyperinsulinism (CHI) is a rare genetic disorder characterized by excess insulin secretion, which results in hypoglycemia. Mutation of sulfonylurea receptor 1 (SUR1), encoded by the ABCC8 gene, is the main cause of CHI. Here, we captured the phenotype of excess insulin secretion through pancreatic differentiation of ABCC8-deficient stem cells generated by the CRISPR/Cas9 system. ABCC8-deficient insulin-producing cells secreted higher insulin than their wild-type counterparts, and the excess insulin secretion was rescued by nifedipine, octreotide and nicorandil. Further, we tested the role of SUR1 in response to different potassium levels and found that dysfunction of SUR1 decreased the insulin secretion rate in low and high potassium environments. Hence, pancreatic differentiation of ABCC8-deficient cells recapitulated the CHI disease phenotype in vitro, which represents an attractive model to further elucidate the function of SUR1 and to develop and screen for novel therapeutic drugs.
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Affiliation(s)
- Dongsheng Guo
- Institute of Public Health, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China.,University of Chinese Academy of Sciences, Beijing, China.,Key Laboratory of Regenerative Biology, South China Institute for Stem Cell Biology and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China.,Guangdong Provincial Key Laboratory of Biocomputing, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China
| | - Haikun Liu
- Institute of Public Health, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China.,Key Laboratory of Regenerative Biology, South China Institute for Stem Cell Biology and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China.,Guangdong Provincial Key Laboratory of Biocomputing, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China
| | - Aynisahan Ruzi
- Institute of Public Health, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China.,University of Chinese Academy of Sciences, Beijing, China.,Key Laboratory of Regenerative Biology, South China Institute for Stem Cell Biology and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China.,Guangdong Provincial Key Laboratory of Biocomputing, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China
| | - Ge Gao
- Institute of Public Health, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China.,Key Laboratory of Regenerative Biology, South China Institute for Stem Cell Biology and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China.,Guangdong Provincial Key Laboratory of Biocomputing, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China
| | - Abbas Nasir
- Institute of Public Health, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China.,University of Chinese Academy of Sciences, Beijing, China.,Key Laboratory of Regenerative Biology, South China Institute for Stem Cell Biology and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China.,Guangdong Provincial Key Laboratory of Biocomputing, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China
| | - Yanli Liu
- Institute of Public Health, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China.,University of Chinese Academy of Sciences, Beijing, China.,Key Laboratory of Regenerative Biology, South China Institute for Stem Cell Biology and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China.,Guangdong Provincial Key Laboratory of Biocomputing, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China
| | - Fan Yang
- Institute of Public Health, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China.,Key Laboratory of Regenerative Biology, South China Institute for Stem Cell Biology and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China.,Guangdong Provincial Key Laboratory of Biocomputing, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China
| | - Feima Wu
- Institute of Public Health, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China.,University of Chinese Academy of Sciences, Beijing, China.,Key Laboratory of Regenerative Biology, South China Institute for Stem Cell Biology and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China.,Guangdong Provincial Key Laboratory of Biocomputing, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China
| | - Guosheng Xu
- Institute of Public Health, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China.,University of Chinese Academy of Sciences, Beijing, China.,Key Laboratory of Regenerative Biology, South China Institute for Stem Cell Biology and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China.,Guangdong Provincial Key Laboratory of Biocomputing, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China
| | - Yin-Xiong Li
- Institute of Public Health, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China. .,University of Chinese Academy of Sciences, Beijing, China. .,Key Laboratory of Regenerative Biology, South China Institute for Stem Cell Biology and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China. .,Guangdong Provincial Key Laboratory of Biocomputing, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China.
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29
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Kim M, Deacon P, Tirona RG, Kim RB, Pin CL, Meyer zu Schwabedissen HE, Wang R, Schwarz UI. Characterization of OATP1B3 and OATP2B1 transporter expression in the islet of the adult human pancreas. Histochem Cell Biol 2017; 148:345-357. [DOI: 10.1007/s00418-017-1580-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/04/2017] [Indexed: 12/19/2022]
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30
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Abstract
The pancreatic β-cell secretes insulin in response to elevated plasma glucose. This review applies an external bioenergetic critique to the central processes of glucose-stimulated insulin secretion, including glycolytic and mitochondrial metabolism, the cytosolic adenine nucleotide pool, and its interaction with plasma membrane ion channels. The control mechanisms responsible for the unique responsiveness of the cell to glucose availability are discussed from bioenergetic and metabolic control standpoints. The concept of coupling factor facilitation of secretion is critiqued, and an attempt is made to unravel the bioenergetic basis of the oscillatory mechanisms controlling secretion. The need to consider the physiological constraints operating in the intact cell is emphasized throughout. The aim is to provide a coherent pathway through an extensive, complex, and sometimes bewildering literature, particularly for those unfamiliar with the field.
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Affiliation(s)
- David G Nicholls
- Buck Institute for Research on Aging, Novato, California; and Department of Clinical Sciences, Unit of Molecular Metabolism, Lund University Diabetes Centre, Malmo, Sweden
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31
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Guzman-Aranguez A, Pérez de Lara MJ, Pintor J. Hyperosmotic stress induces ATP release and changes in P2X7 receptor levels in human corneal and conjunctival epithelial cells. Purinergic Signal 2017; 13:249-258. [PMID: 28176024 DOI: 10.1007/s11302-017-9556-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Accepted: 01/25/2017] [Indexed: 12/31/2022] Open
Abstract
Tear hyperosmolarity is a key event in dry eye. In this work, we analyzed whether hyperosmolar challenge induces ATP release on the ocular surface. Moreover, as extracellular ATP can activate P2X7 receptor, the changes in P2X7 protein levels and its involvement in pathological process triggered by hypertonic treatment were also examined. High-performance liquid chromatography analysis revealed that ATP levels significantly increased in human corneal and conjunctival epithelial cells exposed to hyperosmotic challenge as well as in dry eye patients as compared to control subjects. A significant reduction in cell viability was detected after hyperosmolar treatment, indicating that the rise in ATP release was mainly due to cell lysis/death. Additionally, vesicular nucleotide transporter was identified in both cell lines and their protein expression was upregulated in hypertonic media. P2X7 receptor truncated form together with the full-length form was identified in both cell lines, and experiments using specific antagonist and agonist for P2X7 indicated that this receptor did not mediate cell death induced by hyperosmolar stress. In conclusion, hyperosmotic stress induces ATP release. Extracellular ATP can activate P2X7 receptor leading to cytotoxicity in many cells/tissues; however, this does not occur in human corneal and conjunctival epithelial cells. In these cells, the presence of P2X7 receptor truncated form together with the full-length form hinders a P2X7 apoptotic behavior on the ocular surface.
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Affiliation(s)
- Ana Guzman-Aranguez
- Department of Biochemistry and Molecular Biology IV, Faculty of Optics and Optometry, Universidad Complutense de Madrid, C/Arcos de Jalón 118, 28037, Madrid, Spain.
| | - María J Pérez de Lara
- Department of Biochemistry and Molecular Biology IV, Faculty of Optics and Optometry, Universidad Complutense de Madrid, C/Arcos de Jalón 118, 28037, Madrid, Spain
| | - Jesús Pintor
- Department of Biochemistry and Molecular Biology IV, Faculty of Optics and Optometry, Universidad Complutense de Madrid, C/Arcos de Jalón 118, 28037, Madrid, Spain
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32
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Peters TW, Miller AW, Tourette C, Agren H, Hubbard A, Hughes RE. Genomic Analysis of ATP Efflux in Saccharomyces cerevisiae. G3 (BETHESDA, MD.) 2015; 6:161-70. [PMID: 26585826 PMCID: PMC4704715 DOI: 10.1534/g3.115.023267] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Accepted: 11/06/2015] [Indexed: 01/12/2023]
Abstract
Adenosine triphosphate (ATP) plays an important role as a primary molecule for the transfer of chemical energy to drive biological processes. ATP also functions as an extracellular signaling molecule in a diverse array of eukaryotic taxa in a conserved process known as purinergic signaling. Given the important roles of extracellular ATP in cell signaling, we sought to comprehensively elucidate the pathways and mechanisms governing ATP efflux from eukaryotic cells. Here, we present results of a genomic analysis of ATP efflux from Saccharomyces cerevisiae by measuring extracellular ATP levels in cultures of 4609 deletion mutants. This screen revealed key cellular processes that regulate extracellular ATP levels, including mitochondrial translation and vesicle sorting in the late endosome, indicating that ATP production and transport through vesicles are required for efflux. We also observed evidence for altered ATP efflux in strains deleted for genes involved in amino acid signaling, and mitochondrial retrograde signaling. Based on these results, we propose a model in which the retrograde signaling pathway potentiates amino acid signaling to promote mitochondrial respiration. This study advances our understanding of the mechanism of ATP secretion in eukaryotes and implicates TOR complex 1 (TORC1) and nutrient signaling pathways in the regulation of ATP efflux. These results will facilitate analysis of ATP efflux mechanisms in higher eukaryotes.
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Affiliation(s)
| | - Aaron W Miller
- The Buck Institute for Research on Aging, Novato, California 94945
| | | | - Hannah Agren
- The Buck Institute for Research on Aging, Novato, California 94945
| | - Alan Hubbard
- School of Public Health, Division of Biostatistics, University of California, Berkeley, California 94729-7358
| | - Robert E Hughes
- The Buck Institute for Research on Aging, Novato, California 94945
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33
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Omote H, Miyaji T, Hiasa M, Juge N, Moriyama Y. Structure, Function, and Drug Interactions of Neurotransmitter Transporters in the Postgenomic Era. Annu Rev Pharmacol Toxicol 2015; 56:385-402. [PMID: 26514205 DOI: 10.1146/annurev-pharmtox-010814-124816] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Vesicular neurotransmitter transporters are responsible for the accumulation of neurotransmitters in secretory vesicles and play essential roles in chemical transmission. The SLC17 family contributes to sequestration of anionic neurotransmitters such as glutamate, aspartate, and nucleotides. Identification and subsequent cellular and molecular biological studies of SLC17 transporters unveiled the principles underlying the actions of these transporters. Recent progress in reconstitution methods in combination with postgenomic approaches has advanced studies on neurotransmitter transporters. This review summarizes the molecular properties of SLC17-type transporters and recent findings regarding the novel SLC18 transporter.
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Affiliation(s)
- Hiroshi Omote
- Department of Membrane Biochemistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8530, Japan; ,
| | - Takaaki Miyaji
- Advanced Science Research Center, Okayama University, Okayama 700-8530, Japan
| | - Miki Hiasa
- Department of Membrane Biochemistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8530, Japan; ,
| | - Narinobu Juge
- Advanced Science Research Center, Okayama University, Okayama 700-8530, Japan
| | - Yoshinori Moriyama
- Department of Membrane Biochemistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8530, Japan; , .,Advanced Science Research Center, Okayama University, Okayama 700-8530, Japan
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34
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Ho T, Jobling AI, Greferath U, Chuang T, Ramesh A, Fletcher EL, Vessey KA. Vesicular expression and release of ATP from dopaminergic neurons of the mouse retina and midbrain. Front Cell Neurosci 2015; 9:389. [PMID: 26500494 PMCID: PMC4593860 DOI: 10.3389/fncel.2015.00389] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Accepted: 09/17/2015] [Indexed: 12/20/2022] Open
Abstract
Vesicular nucleotide transporter (VNUT) is required for active accumulation of adenosine tri-phosphate (ATP) into vesicles for purinergic neurotransmission, however, the cell types that express VNUT in the central nervous system remain unknown. This study characterized VNUT expression within the mammalian retina and brain and assessed a possible functional role in purinergic signaling. Two native isoforms of VNUT were detected in mouse retina and brain based on RNA transcript and protein analysis. Using immunohistochemistry, VNUT was found to co-localize with tyrosine hydroxylase (TH) positive, dopaminergic (DA) neurons of the substantia nigra and ventral tegmental area, however, VNUT expression in extranigral non-DA neurons was also observed. In the retina, VNUT labeling was found to co-localize solely with TH-positive DA-cells. In the outer retina, VNUT-positive interplexiform cell processes were in close contact with horizontal cells and cone photoreceptor terminals, which are known to express P2 purinergic-receptors. In order to assess function, dissociated retinal neurons were loaded with fluorescent ATP markers (Quinacrine or Mant-ATP) and the DA marker FFN102, co-labeled with a VNUT antibody and imaged in real time. Fluorescent ATP markers and FFN102 puncta were found to co-localize in VNUT positive neurons and upon stimulation with high potassium, ATP marker fluorescence at the cell membrane was reduced. This response was blocked in the presence of cadmium. These data suggest DA neurons co-release ATP via calcium dependent exocytosis and in the retina this may modulate the visual response by activating purine receptors on closely associated neurons.
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Affiliation(s)
- Tracy Ho
- Visual Neuroscience Laboratory, Department of Anatomy and Neuroscience, The University of Melbourne Parkville, VIC, Australia
| | - Andrew I Jobling
- Visual Neuroscience Laboratory, Department of Anatomy and Neuroscience, The University of Melbourne Parkville, VIC, Australia
| | - Ursula Greferath
- Visual Neuroscience Laboratory, Department of Anatomy and Neuroscience, The University of Melbourne Parkville, VIC, Australia
| | - Trinette Chuang
- Polyclonal Antibody Development, R&D Antibody Development, EMD Millipore Temecula, CA, USA
| | - Archana Ramesh
- Polyclonal Antibody Development, R&D Antibody Development, EMD Millipore Temecula, CA, USA
| | - Erica L Fletcher
- Visual Neuroscience Laboratory, Department of Anatomy and Neuroscience, The University of Melbourne Parkville, VIC, Australia
| | - Kirstan A Vessey
- Visual Neuroscience Laboratory, Department of Anatomy and Neuroscience, The University of Melbourne Parkville, VIC, Australia
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Biochemical characterization of Arabidopsis APYRASE family reveals their roles in regulating endomembrane NDP/NMP homoeostasis. Biochem J 2015; 472:43-54. [PMID: 26338998 DOI: 10.1042/bj20150235] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Accepted: 09/03/2015] [Indexed: 12/27/2022]
Abstract
Plant apyrases are nucleoside triphosphate (NTP) diphosphohydrolases (NTPDases) and have been implicated in an array of functions within the plant including the regulation of extracellular ATP. Arabidopsis encodes a family of seven membrane bound apyrases (AtAPY1-7) that comprise three distinct clades, all of which contain the five conserved apyrase domains. With the exception of AtAPY1 and AtAPY2, the biochemical and the sub-cellular characterization of the other members are currently unavailable. In this research, we have shown all seven Arabidopsis apyrases localize to internal membranes comprising the cis-Golgi, endoplasmic reticulum (ER) and endosome, indicating an endo-apyrase classification for the entire family. In addition, all members, with the exception of AtAPY7, can function as endo-apyrases by complementing a yeast double mutant (Δynd1Δgda1) which lacks apyrase activity. Interestingly, complementation of the mutant yeast using well characterized human apyrases could only be accomplished by using a functional ER endo-apyrase (NTPDase6), but not the ecto-apyrase (NTPDase1). Furthermore, the substrate specificity analysis for the Arabidopsis apyrases AtAPY1-6 indicated that each member has a distinct set of preferred substrates covering various NDPs (nucleoside diphosphates) and NTPs. Combining the biochemical analysis and sub-cellular localization of the Arabidopsis apyrases family, the data suggest their possible roles in regulating endomembrane NDP/NMP (nucleoside monophosphate) homoeostasis.
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Menéndez-Méndez A, Díaz-Hernández JI, Miras-Portugal MT. The vesicular nucleotide transporter (VNUT) is involved in the extracellular ATP effect on neuronal differentiation. Purinergic Signal 2015; 11:239-49. [PMID: 25847073 PMCID: PMC4425722 DOI: 10.1007/s11302-015-9449-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Accepted: 03/25/2015] [Indexed: 12/12/2022] Open
Abstract
Before being released, nucleotides are stored in secretory vesicles through the vesicular nucleotide transporter (VNUT). Once released, extracellular ATP participates in neuronal differentiation processes. Thus, the expression of a functional VNUT could be an additional component of the purinergic system which regulates neuronal differentiation and axonal elongation. In vitro expression of VNUT decreases neuritogenesis in N2a cells differentiated by retinoic acid treatment, whereas silencing of VNUT expression increases the number and length of neurites in these cells. These results highlight the role of VNUT in the neuritogenic process because this transporter regulates the ATP content in neurosecretory vesicles.
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Affiliation(s)
- Aida Menéndez-Méndez
- Facultad de Veterinaria, Departamento de Bioquímica y Biología Molecular IV, Universidad Complutense de Madrid, Madrid, Spain
| | - Juan Ignacio Díaz-Hernández
- Facultad de Veterinaria, Departamento de Bioquímica y Biología Molecular IV, Universidad Complutense de Madrid, Madrid, Spain
| | - M. Teresa Miras-Portugal
- Facultad de Veterinaria, Departamento de Bioquímica y Biología Molecular IV, Universidad Complutense de Madrid, Madrid, Spain
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37
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Harada Y, Hiasa M. Immunological identification of vesicular nucleotide transporter in intestinal L cells. Biol Pharm Bull 2015; 37:1090-5. [PMID: 24989000 DOI: 10.1248/bpb.b14-00275] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
It is well established that vesicular nucleotide transporter (VNUT) is responsible for vesicular storage of nucleotides such as ATP, and that VNUT-expressing cells can secrete nucleotides upon exocytosis, playing an important role in purinergic chemical transmission. In the present study, we show that VNUT is expressed in intestinal L cells. Immunohistochemical evidence indicated that VNUT is present in glucagon-like peptide 1 (GLP-1) containing cells in rat intestine. VNUT immunoreactivity is not co-localized with GLP-1, a marker for secretory granules, and synaptophysin, a marker for synaptic-like microvesicles (SLMVs). Essentially the same results were obtained for GLUTag clonal L cells. Sucrose density gradient analysis confirmed that VNUT is present the light fraction, unlike secretory granules. These results demonstrate that intestinal L cells express VNUT in either the unidentified organelles at light density other than secretory granules and SLMVs or a subpopulation of SLMVs, and suggest that L cells are purinergic in nature and secrete nucleotides independent of GLP-1 secretion.
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Affiliation(s)
- Yuika Harada
- Department of Membrane Biochemistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences
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Tengholm A. Purinergic P2Y1 receptors take centre stage in autocrine stimulation of human beta cells. Diabetologia 2014; 57:2436-9. [PMID: 25277952 DOI: 10.1007/s00125-014-3392-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Accepted: 09/10/2014] [Indexed: 12/20/2022]
Abstract
Insulin secretory vesicles contain high concentrations of adenine nucleotides, which are co-released with insulin during exocytosis. There is strong evidence that ATP and ADP serve as autocrine messengers in pancreatic beta cells, but the functional effects and detailed mechanisms of action are under debate. In this issue of Diabetologia, Khan and colleagues (DOI: 10.1007/s00125-014-3368-8 ) present the results of their study of autocrine purinergic signalling in isolated human beta cells. Using a combination of electrophysiological techniques, Ca(2+) imaging and measurements of insulin secretion, it is demonstrated that voltage-dependent Ca(2+) influx triggers release of ATP/ADP, which activates purinergic receptors of the Gq/11-coupled P2Y1 isoform. Activation of these receptors leads to membrane depolarisation and phospholipase C-mediated mobilisation of Ca(2+) from endoplasmic reticulum stores, which amplifies the exocytosis-triggering Ca(2+) signal. In contrast, there is little evidence for involvement of ionotropic P2X receptors in the autocrine stimulation of human beta cells. This commentary discusses these findings as well as various functional and therapeutic implications of the complex purinergic signalling network in the pancreatic islet.
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Affiliation(s)
- Anders Tengholm
- Department of Medical Cell Biology, Uppsala University, Biomedical Centre, Box 571, SE-751 23, Uppsala, Sweden,
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Khan S, Yan-Do R, Duong E, Wu X, Bautista A, Cheley S, MacDonald PE, Braun M. Autocrine activation of P2Y1 receptors couples Ca (2+) influx to Ca (2+) release in human pancreatic beta cells. Diabetologia 2014; 57:2535-45. [PMID: 25208758 DOI: 10.1007/s00125-014-3368-8] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Accepted: 08/13/2014] [Indexed: 01/26/2023]
Abstract
AIMS/HYPOTHESIS There is evidence that ATP acts as an autocrine signal in beta cells but the receptors and pathways involved are incompletely understood. Here we investigate the receptor subtype(s) and mechanism(s) mediating the effects of ATP on human beta cells. METHODS We examined the effects of purinergic agonists and antagonists on membrane potential, membrane currents, intracellular Ca(2+) ([Ca(2+)]i) and insulin secretion in human beta cells. RESULTS Extracellular application of ATP evoked small inward currents (3.4 ± 0.7 pA) accompanied by depolarisation of the membrane potential (by 14.4 ± 2.4 mV) and stimulation of electrical activity at 6 mmol/l glucose. ATP increased [Ca(2+)]i by stimulating Ca(2+) influx and evoking Ca(2+) release via InsP3-receptors in the endoplasmic reticulum (ER). ATP-evoked Ca(2+) release was sufficient to trigger exocytosis in cells voltage-clamped at -70 mV. All effects of ATP were mimicked by the P2Y(1/12/13) agonist ADP and the P2Y1 agonist MRS-2365, whereas the P2X(1/3) agonist α,β-methyleneadenosine-5-triphosphate only had a small effect. The P2Y1 antagonists MRS-2279 and MRS-2500 hyperpolarised glucose-stimulated beta cells and lowered [Ca(2+)]i in the absence of exogenously added ATP and inhibited glucose-induced insulin secretion by 35%. In voltage-clamped cells subjected to action potential-like stimulation, MRS-2279 decreased [Ca(2+)]i and exocytosis without affecting Ca(2+) influx. CONCLUSIONS/INTERPRETATION These data demonstrate that ATP acts as a positive autocrine signal in human beta cells by activating P2Y1 receptors, stimulating electrical activity and coupling Ca(2+) influx to Ca(2+) release from ER stores.
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Affiliation(s)
- Shara Khan
- Department of Pharmacology, University of Alberta, Edmonton, AB, Canada
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Szkudelski T, Szkudelska K. Regulatory role of adenosine in insulin secretion from pancreatic β-cells--action via adenosine A₁ receptor and beyond. J Physiol Biochem 2014; 71:133-40. [PMID: 25432862 DOI: 10.1007/s13105-014-0371-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Accepted: 11/17/2014] [Indexed: 01/04/2023]
Abstract
Under physiological conditions, insulin secretion from pancreatic β-cells is tightly regulated by different factors, including nutrients, nervous system, and other hormones. Pancreatic β-cells are also influenced by paracrine and autocrine interactions. The results of rodent studies indicate that adenosine is present within pancreatic islets and is implicated in the regulation of insulin secretion; however, effects depend on adenosine and glucose concentrations. Moreover, species differences in adenosine action were found. In rat islets, low adenosine was demonstrated to decrease glucose-induced insulin secretion and this effect is mediated via adenosine A1 receptor. In the presence of high adenosine concentrations, other mechanisms are activated and glucose-induced insulin secretion is increased. It is also well established that suppression of adenosine action increases insulin-secretory response of β-cells to glucose. In mouse islets, low adenosine concentrations do not significantly affect insulin secretion. However, in the presence of higher adenosine concentrations, potentiation of glucose-induced insulin secretion was demonstrated. It is also known that upon stimulation of insulin secretion, both rat and mouse islets release ATP. In rat islets, ATP undergoes extracellular conversion to adenosine. However, mouse islets are unable to convert extracellularly ATP to adenosine and adenosine arises from intracellular ATP degradation.
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Affiliation(s)
- Tomasz Szkudelski
- Department of Animal Physiology and Biochemistry, Poznan University of Life Sciences, Wolynska 35, 60-637, Poznan, Poland,
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Mutafova-Yambolieva VN, Durnin L. The purinergic neurotransmitter revisited: a single substance or multiple players? Pharmacol Ther 2014; 144:162-91. [PMID: 24887688 PMCID: PMC4185222 DOI: 10.1016/j.pharmthera.2014.05.012] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2014] [Accepted: 05/23/2014] [Indexed: 12/20/2022]
Abstract
The past half century has witnessed tremendous advances in our understanding of extracellular purinergic signaling pathways. Purinergic neurotransmission, in particular, has emerged as a key contributor in the efficient control mechanisms in the nervous system. The identity of the purine neurotransmitter, however, remains controversial. Identifying it is difficult because purines are present in all cell types, have a large variety of cell sources, and are released via numerous pathways. Moreover, studies on purinergic neurotransmission have relied heavily on indirect measurements of integrated postjunctional responses that do not provide direct information for neurotransmitter identity. This paper discusses experimental support for adenosine 5'-triphosphate (ATP) as a neurotransmitter and recent evidence for possible contribution of other purines, in addition to or instead of ATP, in chemical neurotransmission in the peripheral, enteric and central nervous systems. Sites of release and action of purines in model systems such as vas deferens, blood vessels, urinary bladder and chromaffin cells are discussed. This is preceded by a brief discussion of studies demonstrating storage of purines in synaptic vesicles. We examine recent evidence for cell type targets (e.g., smooth muscle cells, interstitial cells, neurons and glia) for purine neurotransmitters in different systems. This is followed by brief discussion of mechanisms of terminating the action of purine neurotransmitters, including extracellular nucleotide hydrolysis and possible salvage and reuptake in the cell. The significance of direct neurotransmitter release measurements is highlighted. Possibilities for involvement of multiple purines (e.g., ATP, ADP, NAD(+), ADP-ribose, adenosine, and diadenosine polyphosphates) in neurotransmission are considered throughout.
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Affiliation(s)
| | - Leonie Durnin
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, NV 89557, United States
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Sakamoto S, Miyaji T, Hiasa M, Ichikawa R, Uematsu A, Iwatsuki K, Shibata A, Uneyama H, Takayanagi R, Yamamoto A, Omote H, Nomura M, Moriyama Y. Impairment of vesicular ATP release affects glucose metabolism and increases insulin sensitivity. Sci Rep 2014; 4:6689. [PMID: 25331291 PMCID: PMC4204045 DOI: 10.1038/srep06689] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Accepted: 09/17/2014] [Indexed: 12/04/2022] Open
Abstract
Neuroendocrine cells store ATP in secretory granules and release it along with hormones that may trigger a variety of cellular responses in a process called purinergic chemical transmission. Although the vesicular nucleotide transporter (VNUT) has been shown to be involved in vesicular storage and release of ATP, its physiological relevance in vivo is far less well understood. In Vnut knockout (Vnut(-/-)) mice, we found that the loss of functional VNUT in adrenal chromaffin granules and insulin granules in the islets of Langerhans led to several significant effects. Vesicular ATP accumulation and depolarization-dependent ATP release were absent in the chromaffin granules of Vnut(-/-) mice. Glucose-responsive ATP release was also absent in pancreatic β-cells in Vnut(-/-) mice, while glucose-responsive insulin secretion was enhanced to a greater extent than that in wild-type tissue. Vnut(-/-) mice exhibited improved glucose tolerance and low blood glucose upon fasting due to increased insulin sensitivity. These results demonstrated an essential role of VNUT in vesicular storage and release of ATP in neuroendocrine cells in vivo and suggest that vesicular ATP and/or its degradation products act as feedback regulators in catecholamine and insulin secretion, thereby regulating blood glucose homeostasis.
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Affiliation(s)
- Shohei Sakamoto
- Department of Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, JAPAN
| | - Takaaki Miyaji
- Advanced Research Science Center, Okayama University, Okayama 700-8530, JAPAN
| | - Miki Hiasa
- Department of Membrane Biochemistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8530, JAPAN
| | - Reiko Ichikawa
- Institute for Innovation, Ajinomoto Co., Inc. Kawasaki 210-5893, JAPAN
| | - Akira Uematsu
- Institute for Innovation, Ajinomoto Co., Inc. Kawasaki 210-5893, JAPAN
| | - Ken Iwatsuki
- Institute for Innovation, Ajinomoto Co., Inc. Kawasaki 210-5893, JAPAN
| | - Atsushi Shibata
- Department of Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, JAPAN
| | - Hisayuki Uneyama
- Institute for Innovation, Ajinomoto Co., Inc. Kawasaki 210-5893, JAPAN
| | - Ryoichi Takayanagi
- Department of Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, JAPAN
| | - Akitsugu Yamamoto
- Faculty of Bioscience, Nagahama Institute of Bio-science and Technology, Nagahama 526-0829, JAPAN
| | - Hiroshi Omote
- Department of Membrane Biochemistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8530, JAPAN
| | - Masatoshi Nomura
- Department of Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, JAPAN
| | - Yoshinori Moriyama
- Advanced Research Science Center, Okayama University, Okayama 700-8530, JAPAN
- Department of Membrane Biochemistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8530, JAPAN
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Cao Q, Zhao K, Zhong XZ, Zou Y, Yu H, Huang P, Xu TL, Dong XP. SLC17A9 protein functions as a lysosomal ATP transporter and regulates cell viability. J Biol Chem 2014; 289:23189-23199. [PMID: 24962569 DOI: 10.1074/jbc.m114.567107] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Lysosomes contain abundant ATP, which is released through lysosomal exocytosis following exposure to various stimuli. However, the molecular mechanisms underlying lysosomal ATP accumulation remain unknown. The vesicular nucleotide transporter, also known as solute carrier family 17 member 9 (SLC17A9), has been shown to function in ATP transport across secretory vesicles/granules membrane in adrenal chromaffin cells, T cells, and pancreatic cells. Here, using mammalian cell lines, we report that SLC17A9 is highly enriched in lysosomes and functions as an ATP transporter in those organelles. SLC17A9 deficiency reduced lysosome ATP accumulation and compromised lysosome function, resulting in cell death. Our data suggest that SLC17A9 activity mediates lysosomal ATP accumulation and plays an important role in lysosomal physiology and cell viability.
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Affiliation(s)
- Qi Cao
- Department of Physiology and Biophysics, Dalhousie University, Halifax B3H 4R2, Nova Scotia, Canada and
| | - Kexin Zhao
- Department of Physiology and Biophysics, Dalhousie University, Halifax B3H 4R2, Nova Scotia, Canada and
| | - Xi Zoë Zhong
- Department of Physiology and Biophysics, Dalhousie University, Halifax B3H 4R2, Nova Scotia, Canada and
| | - Yuanjie Zou
- Department of Physiology and Biophysics, Dalhousie University, Halifax B3H 4R2, Nova Scotia, Canada and
| | - Haichuan Yu
- Department of Physiology and Biophysics, Dalhousie University, Halifax B3H 4R2, Nova Scotia, Canada and
| | - Peng Huang
- Department of Physiology and Biophysics, Dalhousie University, Halifax B3H 4R2, Nova Scotia, Canada and
| | - Tian-Le Xu
- Shanghai Key Laboratory for Tumor Microenvironment and Inflammation, Institute of Medical Sciences, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Xian-Ping Dong
- Department of Physiology and Biophysics, Dalhousie University, Halifax B3H 4R2, Nova Scotia, Canada and.
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Hiasa M, Togawa N, Miyaji T, Omote H, Yamamoto A, Moriyama Y. Essential role of vesicular nucleotide transporter in vesicular storage and release of nucleotides in platelets. Physiol Rep 2014; 2:2/6/e12034. [PMID: 24907298 PMCID: PMC4208647 DOI: 10.14814/phy2.12034] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Nucleotides are stored in the dense granules of platelets. The release of nucleotides triggers one of the first steps in a series of cascades responsible for blood coagulation. However, the mechanism of how the nucleotides are accumulated in the granules is still far less understood. The transporter protein responsible for storage of nucleotides in the neuroendocrine cells has been identified and characterized. We hypothesized that the vesicular nucleotide transporter (VNUT) is also involved in the vesicular storage of nucleotides in platelets. In this article, we present three lines of evidence that VNUT is responsible for the vesicular storage of nucleotides in platelets and that vesicular ATP transport is crucial for platelet function, detection and characterization of VNUT activity in platelets isolated from healthy humans and MEG‐01 cells, RNA interference experiments on MEG‐01 cells, and studies on nucleotide transport and release with a selective inhibitor. VNUT is highly expressed and associated with dense granules in platelets. VNUT plays an essential role in vesicular storage of nucleotide in platelets.
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Affiliation(s)
- Miki Hiasa
- Department of Membrane Biochemistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Natsuko Togawa
- Department of Membrane Biochemistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Takaaki Miyaji
- Advanced Science Research Center, Okayama University, Okayama, Japan
| | - Hiroshi Omote
- Department of Membrane Biochemistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Akitsugu Yamamoto
- Department of Cell Biology, Nagahama Institute of Technology, Nagahama, Japan
| | - Yoshinori Moriyama
- Department of Membrane Biochemistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan Advanced Science Research Center, Okayama University, Okayama, Japan
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Yamada Y, Tabata M, Yasuzaki Y, Nomura M, Shibata A, Ibayashi Y, Taniguchi Y, Sasaki S, Harashima H. A nanocarrier system for the delivery of nucleic acids targeted to a pancreatic beta cell line. Biomaterials 2014; 35:6430-8. [PMID: 24816283 DOI: 10.1016/j.biomaterials.2014.04.017] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2014] [Accepted: 04/05/2014] [Indexed: 11/25/2022]
Abstract
Pancreatic β cells secrete insulin in response to glucose levels and thus are involved in controlling blood glucose levels. A line of pancreatic β cells "MIN6" has been used in studies related to the function of β cells and diabetes therapy. Regulating gene expression in MIN6 cells could accelerate these studies, but an efficient method for the transfection of nucleic acids targeted to MIN6 cells is required. We report here on a liposome-based carrier targeted to pancreatic β cells (Multifunctional envelope-type nano device for pancreatic β cells, β-MEND). We identified a lipid composition for use in preparing the β-MEND, which permits the particles to be efficiently internalized into MIN6, as evidenced by flow cytometry analyses. Intracellular observation by confocal laser scanning microscopy showed that the β-MEND efficiently delivered the oligo nucleic acids to the cytosol of MIN6 cells. Moreover, using a β-MEND encapsulating a 2'-O-Methyl RNA complementary to a microRNA that suppresses insulin secretion, the knockdown of the targeted microRNA and an up-regulation of insulin secretion were observed in MIN6. Thus, the β-MEND holds promise as an efficient system for delivering nucleic acids targeted to MIN6 and can contribute to research and therapy aimed at diabetes.
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Affiliation(s)
- Yuma Yamada
- Laboratory for Molecular Design of Pharmaceutics, Faculty of Pharmaceutical Sciences, Hokkaido University, Kita-12, Nishi-6, Kita-ku, Sapporo 060-0812, Japan
| | - Mai Tabata
- Laboratory for Molecular Design of Pharmaceutics, Faculty of Pharmaceutical Sciences, Hokkaido University, Kita-12, Nishi-6, Kita-ku, Sapporo 060-0812, Japan
| | - Yukari Yasuzaki
- Laboratory for Molecular Design of Pharmaceutics, Faculty of Pharmaceutical Sciences, Hokkaido University, Kita-12, Nishi-6, Kita-ku, Sapporo 060-0812, Japan
| | - Masatoshi Nomura
- Department of Endocrine and Metabolic Diseases/Diabetes Mellitus, Kyushu University Hospital, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Atsushi Shibata
- Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Yuta Ibayashi
- Department of Endocrine and Metabolic Diseases/Diabetes Mellitus, Kyushu University Hospital, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Yosuke Taniguchi
- Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Shigeki Sasaki
- Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Hideyoshi Harashima
- Laboratory for Molecular Design of Pharmaceutics, Faculty of Pharmaceutical Sciences, Hokkaido University, Kita-12, Nishi-6, Kita-ku, Sapporo 060-0812, Japan.
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Lazarenko R, Geisler J, Bayliss D, Larner J, Li C. D-chiro-inositol glycan stimulates insulin secretion in pancreatic β cells. Mol Cell Endocrinol 2014; 387:1-7. [PMID: 24530497 PMCID: PMC4366192 DOI: 10.1016/j.mce.2014.02.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Revised: 01/30/2014] [Accepted: 02/07/2014] [Indexed: 12/25/2022]
Abstract
Insulin has been shown to act on pancreatic β cells to regulate its own secretion. Currently the mechanism underlying this effect is unclear. INS-2, a novel inositol glycan pseudo-disaccharide containing D-chiro-inositol and galactosamine, has been shown to function as an insulin mimetic and a putative insulin mediator. In the present study we found that INS-2 stimulates insulin secretion in MIN6 β cells and potentiates glucose stimulated insulin secretion in isolated mouse islets. Importantly, INS-2 failed to potentiate insulin secretion induced by tolbutamide, which stimulates insulin release by closing ATP sensitive potassium channels (KATP). Electrophysiological studies showed that INS-2 inhibited sulfonylurea-sensitive KATP conductance. The effect of INS-2 on inhibiting KATP channel is mediated by protein phosphatase 2C (PP2C), as knocking down PP2C expression in MIN6 cells by PP2C small hairpin RNA completely abolished the effect of INS-2 on KATP and consequently attenuated INS-2 induced insulin secretion. In conclusion, the present study identifies a novel mechanism involving PP2C in regulating KATP channel activity and consequently insulin secretion.
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Affiliation(s)
- Roman Lazarenko
- Department of Pharmacology, University of Virginia Health System, Charlottesville, VA, United States
| | - Jessica Geisler
- Department of Pharmacology, University of Virginia Health System, Charlottesville, VA, United States
| | - Douglas Bayliss
- Department of Pharmacology, University of Virginia Health System, Charlottesville, VA, United States
| | - Joseph Larner
- Department of Pharmacology, University of Virginia Health System, Charlottesville, VA, United States
| | - Chien Li
- Department of Pharmacology, University of Virginia Health System, Charlottesville, VA, United States.
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Burnstock G. Purinergic signalling in endocrine organs. Purinergic Signal 2014; 10:189-231. [PMID: 24265070 PMCID: PMC3944044 DOI: 10.1007/s11302-013-9396-x] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Accepted: 10/24/2013] [Indexed: 01/08/2023] Open
Abstract
There is widespread involvement of purinergic signalling in endocrine biology. Pituitary cells express P1, P2X and P2Y receptor subtypes to mediate hormone release. Adenosine 5'-triphosphate (ATP) regulates insulin release in the pancreas and is involved in the secretion of thyroid hormones. ATP plays a major role in the synthesis, storage and release of catecholamines from the adrenal gland. In the ovary purinoceptors mediate gonadotrophin-induced progesterone secretion, while in the testes, both Sertoli and Leydig cells express purinoceptors that mediate secretion of oestradiol and testosterone, respectively. ATP released as a cotransmitter with noradrenaline is involved in activities of the pineal gland and in the neuroendocrine control of the thymus. In the hypothalamus, ATP and adenosine stimulate or modulate the release of luteinising hormone-releasing hormone, as well as arginine-vasopressin and oxytocin. Functionally active P2X and P2Y receptors have been identified on human placental syncytiotrophoblast cells and on neuroendocrine cells in the lung, skin, prostate and intestine. Adipocytes have been recognised recently to have endocrine function involving purinoceptors.
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Affiliation(s)
- Geoffrey Burnstock
- Autonomic Neuroscience Centre, University College Medical School, Rowland Hill Street, London, NW3 2PF, UK,
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Miklavc P, Thompson KE, Frick M. A new role for P2X4 receptors as modulators of lung surfactant secretion. Front Cell Neurosci 2013; 7:171. [PMID: 24115920 PMCID: PMC3792447 DOI: 10.3389/fncel.2013.00171] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Accepted: 09/12/2013] [Indexed: 12/17/2022] Open
Abstract
In recent years, P2X receptors have attracted increasing attention as regulators of exocytosis and cellular secretion. In various cell types, P2X receptors have been found to stimulate vesicle exocytosis directly via Ca(2+) influx and elevation of the intracellular Ca(2+) concentration. Recently, a new role for P2X4 receptors as regulators of secretion emerged. Exocytosis of lamellar bodies (LBs), large storage organelles for lung surfactant, results in a local, fusion-activated Ca(2+) entry (FACE) in alveolar type II epithelial cells. FACE is mediated via P2X4 receptors that are located on the limiting membrane of LBs and inserted into the plasma membrane upon exocytosis of LBs. The localized Ca(2+) influx at the site of vesicle fusion promotes fusion pore expansion and facilitates surfactant release. In addition, this inward-rectifying cation current across P2X4 receptors mediates fluid resorption from lung alveoli. It is hypothesized that the concomitant reduction in the alveolar lining fluid facilitates insertion of surfactant into the air-liquid interphase thereby "activating" it. These findings constitute a novel role for P2X4 receptors in regulating vesicle content secretion as modulators of the secretory output during the exocytic post-fusion phase.
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Affiliation(s)
- Pika Miklavc
- Institute of General Physiology, University of Ulm Ulm, Germany
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49
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Sesma JI, Kreda SM, Okada SF, van Heusden C, Moussa L, Jones LC, O'Neal WK, Togawa N, Hiasa M, Moriyama Y, Lazarowski ER. Vesicular nucleotide transporter regulates the nucleotide content in airway epithelial mucin granules. Am J Physiol Cell Physiol 2013; 304:C976-84. [PMID: 23467297 DOI: 10.1152/ajpcell.00371.2012] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Nucleotides within the airway surface liquid promote fluid secretion via activation of airway epithelial purinergic receptors. ATP is stored within and released from mucin granules as co-cargo with mucins, but the mechanism by which ATP, and potentially other nucleotides, enter the lumen of mucin granules is not known. We assessed the contribution of the recently identified SLC17A9 vesicle nucleotide transporter (VNUT) to the nucleotide availability within isolated mucin granules and further examined the involvement of VNUT in mucin granule secretion-associated nucleotide release. RT-PCR and Western blot analyses indicated that VNUT is abundantly expressed in airway epithelial goblet-like Calu-3 cells, migrating as a duplex with apparent mobility of 55 and 60 kDa. Subcellular fractionation studies indicated that VNUT55 was associated with high-density mucin granules, whereas VNUT60 was associated with low-density organelles. Immunofluorescence studies showed that recombinant VNUT localized to mucin granules and other organelles. Mucin granules isolated from VNUT short hairpin RNA-expressing cells exhibited a marked reduction of ATP, ADP, AMP, and UTP levels within granules. Ca(2+)-regulated vesicular ATP release was markedly reduced in these cells, but mucin secretion was not affected. These results suggest that VNUT is the relevant nucleotide transporter responsible for the uptake of cytosolic nucleotides into mucin granules. By controlling the entry of nucleotides into mucin granules, VNUT contributes to the release of purinergic signaling molecules necessary for the proper hydration of co-released mucins.
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Affiliation(s)
- Juliana I Sesma
- Cystic Fibrosis/Pulmonary Research and Treatment Center, University of North Carolina, Chapel Hill, NC 27599, USA
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50
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Stojilkovic SS, Zemkova H. P2X receptor channels in endocrine glands. WILEY INTERDISCIPLINARY REVIEWS. MEMBRANE TRANSPORT AND SIGNALING 2013; 2:173-180. [PMID: 24073387 PMCID: PMC3780426 DOI: 10.1002/wmts.89] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The endocrine system is the system of ductless glands and single cells that synthetize hormones and release them directly into the bloodstream. Regulation of endocrine system is very complex and ATP and its degradable products ADP and adenosine contribute to its regulation acting as extracellular messengers for purinergic receptors. These include P2X receptors, a family of ligand-gated ion channels which expression and roles in endocrine tissues are reviewed here. There are seven mammalian purinergic receptor subunits, denoted P2X1 through P2X7, and the majority of these subunits are also expressed in secretory and non-secretory cells of endocrine system. Functional channels have been identified in the neuroendocrine hypothalamus, the posterior and anterior pituitary, the thyroid gland, the adrenals, the endocrine pancreas, the gonads and the placenta. Native channels are capable of promoting calcium influx through its pore in both excitable and non-excitable cells, as well as of increasing electrical activity in excitable cells by membrane depolarization. This leads to generation of calcium transients and stimulation of hormone release. The pattern of expression and action of P2XRs in endocrine system suggests that locally produced ATP amplifies and synchronizes the secretory responses of individual cells.
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Affiliation(s)
- Stanko S. Stojilkovic
- Section on Cellular Signaling, Program in Developmental Neuroscience, The Eunice Kennedy Shiver National Institutes of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892-4510
| | - Hana Zemkova
- Department of Cellular and Molecular Neuroendocrinology, Institute of Physiology of the Academy of Sciences, Prague, Czech Republic
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