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Fleming T, Tachizawa M, Nishiike Y, Koiwa A, Homan Y, Okubo K. Estrogen-dependent expression and function of secretogranin 2a in female-specific peptidergic neurons. PNAS NEXUS 2023; 2:pgad413. [PMID: 38111823 PMCID: PMC10726998 DOI: 10.1093/pnasnexus/pgad413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Accepted: 11/13/2023] [Indexed: 12/20/2023]
Abstract
Secretogranin 2 (Scg2) is a member of the secretogranin/chromogranin family of proteins that is involved in neuropeptide and hormone packaging to secretory granules and serves as a precursor for several secreted pleiotropic peptides. A recent study in zebrafish showed that the teleost Scg2 orthologs, scg2a and scg2b, play an important role in mating behavior, but its modes of action and regulatory mechanisms remain unclear. In this study, we identify scg2a in another teleost species, medaka, by transcriptomic analysis as a gene that is expressed in an ovarian secretion-dependent manner in a group of neurons relevant to female sexual receptivity, termed FeSP neurons. Investigation of scg2a expression in the FeSP neurons of estrogen receptor (Esr)-deficient medaka revealed that it is dependent on estrogen signaling through Esr2b, the major determinant of female-typical mating behavior. Generation and characterization of scg2a-deficient medaka showed no overt changes in secretory granule packaging in FeSP neurons. This, along with the observation that Scg2a and neuropeptide B, a major neuropeptide produced by FeSP neurons, colocalize in a majority of secretory granules, suggests that Scg2a mainly serves as a precursor for secreted peptides that act in conjunction with neuropeptide B. Further, scg2a showed sexually biased expression in several brain nuclei implicated in mating behavior. However, we found no significant impact of scg2a deficiency on the performance of mating behavior in either sex. Collectively, our results indicate that, although perhaps not essential for mating behavior, scg2a acts in an estrogen/Esr2b signaling-dependent manner in neurons that are relevant to female sexual receptivity.
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Affiliation(s)
- Thomas Fleming
- Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan
| | - Masaya Tachizawa
- Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan
| | - Yuji Nishiike
- Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan
| | - Ai Koiwa
- Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan
| | - Yuki Homan
- Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan
| | - Kataaki Okubo
- Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan
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2
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Štepihar D, Florke Gee RR, Hoyos Sanchez MC, Fon Tacer K. Cell-specific secretory granule sorting mechanisms: the role of MAGEL2 and retromer in hypothalamic regulated secretion. Front Cell Dev Biol 2023; 11:1243038. [PMID: 37799273 PMCID: PMC10548473 DOI: 10.3389/fcell.2023.1243038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Accepted: 08/31/2023] [Indexed: 10/07/2023] Open
Abstract
Intracellular protein trafficking and sorting are extremely arduous in endocrine and neuroendocrine cells, which synthesize and secrete on-demand substantial quantities of proteins. To ensure that neuroendocrine secretion operates correctly, each step in the secretion pathways is tightly regulated and coordinated both spatially and temporally. At the trans-Golgi network (TGN), intrinsic structural features of proteins and several sorting mechanisms and distinct signals direct newly synthesized proteins into proper membrane vesicles that enter either constitutive or regulated secretion pathways. Furthermore, this anterograde transport is counterbalanced by retrograde transport, which not only maintains membrane homeostasis but also recycles various proteins that function in the sorting of secretory cargo, formation of transport intermediates, or retrieval of resident proteins of secretory organelles. The retromer complex recycles proteins from the endocytic pathway back to the plasma membrane or TGN and was recently identified as a critical player in regulated secretion in the hypothalamus. Furthermore, melanoma antigen protein L2 (MAGEL2) was discovered to act as a tissue-specific regulator of the retromer-dependent endosomal protein recycling pathway and, by doing so, ensures proper secretory granule formation and maturation. MAGEL2 is a mammalian-specific and maternally imprinted gene implicated in Prader-Willi and Schaaf-Yang neurodevelopmental syndromes. In this review, we will briefly discuss the current understanding of the regulated secretion pathway, encompassing anterograde and retrograde traffic. Although our understanding of the retrograde trafficking and sorting in regulated secretion is not yet complete, we will review recent insights into the molecular role of MAGEL2 in hypothalamic neuroendocrine secretion and how its dysregulation contributes to the symptoms of Prader-Willi and Schaaf-Yang patients. Given that the activation of many secreted proteins occurs after they enter secretory granules, modulation of the sorting efficiency in a tissue-specific manner may represent an evolutionary adaptation to environmental cues.
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Affiliation(s)
- Denis Štepihar
- School of Veterinary Medicine, Texas Tech University, Amarillo, TX, United States
- Texas Center for Comparative Cancer Research (TC3R), Amarillo, TX, United States
- Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - Rebecca R. Florke Gee
- School of Veterinary Medicine, Texas Tech University, Amarillo, TX, United States
- Texas Center for Comparative Cancer Research (TC3R), Amarillo, TX, United States
| | - Maria Camila Hoyos Sanchez
- School of Veterinary Medicine, Texas Tech University, Amarillo, TX, United States
- Texas Center for Comparative Cancer Research (TC3R), Amarillo, TX, United States
| | - Klementina Fon Tacer
- School of Veterinary Medicine, Texas Tech University, Amarillo, TX, United States
- Texas Center for Comparative Cancer Research (TC3R), Amarillo, TX, United States
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3
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Maneu V, Borges R, Gandía L, García AG. Forty years of the adrenal chromaffin cell through ISCCB meetings around the world. Pflugers Arch 2023; 475:667-690. [PMID: 36884064 DOI: 10.1007/s00424-023-02793-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 01/20/2023] [Accepted: 01/28/2023] [Indexed: 03/09/2023]
Abstract
This historical review focuses on the evolution of the knowledge accumulated during the last two centuries on the biology of the adrenal medulla gland and its chromaffin cells (CCs). The review emerged in the context of a series of meetings that started on the Spanish island of Ibiza in 1982 with the name of the International Symposium on Chromaffin Cell Biology (ISCCB). Hence, the review is divided into two periods namely, before 1982 and from this year to 2022, when the 21st ISCCB meeting was just held in Hamburg, Germany. The first historical period extends back to 1852 when Albert Kölliker first described the fine structure and function of the adrenal medulla. Subsequently, the adrenal staining with chromate salts identified the CCs; this was followed by the establishment of the embryological origin of the adrenal medulla, and the identification of adrenaline-storing vesicles. By the end of the nineteenth century, the basic morphology, histochemistry, and embryology of the adrenal gland were known. The twentieth century began with breakthrough findings namely, the experiment of Elliott suggesting that adrenaline was the sympathetic neurotransmitter, the isolation of pure adrenaline, and the deciphering of its molecular structure and chemical synthesis in the laboratory. In the 1950s, Blaschko isolated the catecholamine-storing vesicles from adrenal medullary extracts. This switched the interest in CCs as models of sympathetic neurons with an explosion of studies concerning their functions, i.e., uptake of catecholamines by chromaffin vesicles through a specific coupled transport system; the identification of several vesicle components in addition to catecholamines including chromogranins, ATP, opioids, and other neuropeptides; the calcium-dependence of the release of catecholamines; the underlying mechanism of exocytosis of this release, as indicated by the co-release of proteins; the cross-talk between the adrenal cortex and the medulla; and the emission of neurite-like processes by CCs in culture, among other numerous findings. The 1980s began with the introduction of new high-resolution techniques such as patch-clamp, calcium probes, marine toxins-targeting ion channels and receptors, confocal microscopy, or amperometry. In this frame of technological advances at the Ibiza ISCCB meeting in 1982, 11 senior researchers in the field predicted a notable increase in our knowledge in the field of CCs and the adrenal medulla; this cumulative knowledge that occurred in the last 40 years of history of the CC is succinctly described in the second part of this historical review. It deals with cell excitability, ion channel currents, the exocytotic fusion pore, the handling of calcium ions by CCs, the kinetics of exocytosis and endocytosis, the exocytotic machinery, and the life cycle of secretory vesicles. These concepts together with studies on the dynamics of membrane fusion with super-resolution imaging techniques at the single-protein level were extensively reviewed by top scientists in the field at the 21st ISCCB meeting in Hamburg in the summer of 2022; this frontier topic is also briefly reviewed here. Many of the concepts arising from those studies contributed to our present understanding of synaptic transmission. This has been studied in physiological or pathophysiological conditions, in CCs from animal disease models. In conclusion, the lessons we have learned from CC biology as a peripheral model for brain and brain disease pertain more than ever to cutting-edge research in neurobiology. In the 22nd ISCCB meeting in Israel in 2024 that Uri Asheri is organizing, we will have the opportunity of seeing the progress of the questions posed in Ibiza, and on other questions that undoubtedly will arise.
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Affiliation(s)
- Victoria Maneu
- Departamento de Óptica, Farmacología y Anatomía, Universidad de Alicante, Alicante, Spain
| | - Ricardo Borges
- Unidad de Farmacología, Departamento de Medicina Física y Farmacología, Facultad de Medicina, Universidad de La Laguna, Tenerife, Spain
| | - Luis Gandía
- Instituto Fundación Teófilo Hernando, Madrid, Spain.,Departamento de Farmacología y Terapéutica, Universidad Autónoma de Madrid, Madrid, Spain
| | - Antonio G García
- Instituto Fundación Teófilo Hernando, Madrid, Spain. .,Departamento de Farmacología y Terapéutica, Universidad Autónoma de Madrid, Madrid, Spain. .,Facultad de Medicina, Instituto de Investigación Sanitaria del Hospital Universitario La Princesa, Universidad Autónoma de Madrid, Madrid, Spain.
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4
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Parchure A, Tian M, Stalder D, Boyer CK, Bearrows SC, Rohli KE, Zhang J, Rivera-Molina F, Ramazanov BR, Mahata SK, Wang Y, Stephens SB, Gershlick DC, von Blume J. Liquid-liquid phase separation facilitates the biogenesis of secretory storage granules. J Cell Biol 2022; 221:e202206132. [PMID: 36173346 PMCID: PMC9526250 DOI: 10.1083/jcb.202206132] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 08/30/2022] [Accepted: 09/01/2022] [Indexed: 02/03/2023] Open
Abstract
Insulin is synthesized by pancreatic β-cells and stored into secretory granules (SGs). SGs fuse with the plasma membrane in response to a stimulus and deliver insulin to the bloodstream. The mechanism of how proinsulin and its processing enzymes are sorted and targeted from the trans-Golgi network (TGN) to SGs remains mysterious. No cargo receptor for proinsulin has been identified. Here, we show that chromogranin (CG) proteins undergo liquid-liquid phase separation (LLPS) at a mildly acidic pH in the lumen of the TGN, and recruit clients like proinsulin to the condensates. Client selectivity is sequence-independent but based on the concentration of the client molecules in the TGN. We propose that the TGN provides the milieu for converting CGs into a "cargo sponge" leading to partitioning of client molecules, thus facilitating receptor-independent client sorting. These findings provide a new receptor-independent sorting model in β-cells and many other cell types and therefore represent an innovation in the field of membrane trafficking.
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Affiliation(s)
- Anup Parchure
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT
| | - Meng Tian
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT
| | - Danièle Stalder
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, UK
| | - Cierra K. Boyer
- Departments of Pharmacology and Neuroscience, Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Iowa City, IA
- Internal Medicine, Division of Endocrinology and Metabolism, University of Iowa, Iowa City, IA
| | - Shelby C. Bearrows
- Departments of Pharmacology and Neuroscience, Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Iowa City, IA
- Internal Medicine, Division of Endocrinology and Metabolism, University of Iowa, Iowa City, IA
| | - Kristen E. Rohli
- Departments of Pharmacology and Neuroscience, Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Iowa City, IA
- Internal Medicine, Division of Endocrinology and Metabolism, University of Iowa, Iowa City, IA
| | - Jianchao Zhang
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI
- Department of Neurology, University of Michigan School of Medicine, Ann Arbor, MI
| | - Felix Rivera-Molina
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT
| | - Bulat R. Ramazanov
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT
| | - Sushil K. Mahata
- Department of Medicine, University of California San Diego, La Jolla, CA
- VA San Diego Healthcare System, San Diego, CA
| | - Yanzhuang Wang
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI
- Department of Neurology, University of Michigan School of Medicine, Ann Arbor, MI
| | - Samuel B. Stephens
- Departments of Pharmacology and Neuroscience, Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Iowa City, IA
| | - David C. Gershlick
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, UK
| | - Julia von Blume
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT
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5
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Lin Z, Li Y, Hang Y, Wang C, Liu B, Li J, Yin L, Jiang X, Du X, Qiao Z, Zhu F, Zhang Z, Zhang Q, Zhou Z. Tuning the Size of Large Dense-Core Vesicles and Quantal Neurotransmitter Release via Secretogranin II Liquid-Liquid Phase Separation. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2202263. [PMID: 35896896 PMCID: PMC9507364 DOI: 10.1002/advs.202202263] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 06/12/2022] [Indexed: 06/15/2023]
Abstract
Large dense-core vesicles (LDCVs) are larger in volume than synaptic vesicles, and are filled with multiple neuropeptides, hormones, and neurotransmitters that participate in various physiological processes. However, little is known about the mechanism determining the size of LDCVs. Here, it is reported that secretogranin II (SgII), a vesicle matrix protein, contributes to LDCV size regulation through its liquid-liquid phase separation in neuroendocrine cells. First, SgII undergoes pH-dependent polymerization and the polymerized SgII forms phase droplets with Ca2+ in vitro and in vivo. Further, the Ca2+ -induced SgII droplets recruit reconstituted bio-lipids, mimicking the LDCVs biogenesis. In addition, SgII knockdown leads to significant decrease of the quantal neurotransmitter release by affecting LDCV size, which is differently rescued by SgII truncations with different degrees of phase separation. In conclusion, it is shown that SgII is a unique intravesicular matrix protein undergoing liquid-liquid phase separation, and present novel insights into how SgII determines LDCV size and the quantal neurotransmitter release.
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Affiliation(s)
- Zhaohan Lin
- State Key Laboratory of Membrane Biology and Beijing Key Laboratory of Cardiometabolic Molecular MedicineInstitute of Molecular MedicineCollege of Future TechnologyPeking‐Tsinghua Center for Life Sciences, and PKU‐IDG/McGovern Institute for Brain ResearchPeking UniversityBeijing100871China
| | - Yinglin Li
- State Key Laboratory of Membrane Biology and Beijing Key Laboratory of Cardiometabolic Molecular MedicineInstitute of Molecular MedicineCollege of Future TechnologyPeking‐Tsinghua Center for Life Sciences, and PKU‐IDG/McGovern Institute for Brain ResearchPeking UniversityBeijing100871China
| | - Yuqi Hang
- State Key Laboratory of Membrane Biology and Beijing Key Laboratory of Cardiometabolic Molecular MedicineInstitute of Molecular MedicineCollege of Future TechnologyPeking‐Tsinghua Center for Life Sciences, and PKU‐IDG/McGovern Institute for Brain ResearchPeking UniversityBeijing100871China
| | - Changhe Wang
- State Key Laboratory of Membrane Biology and Beijing Key Laboratory of Cardiometabolic Molecular MedicineInstitute of Molecular MedicineCollege of Future TechnologyPeking‐Tsinghua Center for Life Sciences, and PKU‐IDG/McGovern Institute for Brain ResearchPeking UniversityBeijing100871China
| | - Bing Liu
- State Key Laboratory of Membrane Biology and Beijing Key Laboratory of Cardiometabolic Molecular MedicineInstitute of Molecular MedicineCollege of Future TechnologyPeking‐Tsinghua Center for Life Sciences, and PKU‐IDG/McGovern Institute for Brain ResearchPeking UniversityBeijing100871China
| | - Jie Li
- State Key Laboratory of Membrane Biology and Beijing Key Laboratory of Cardiometabolic Molecular MedicineInstitute of Molecular MedicineCollege of Future TechnologyPeking‐Tsinghua Center for Life Sciences, and PKU‐IDG/McGovern Institute for Brain ResearchPeking UniversityBeijing100871China
| | - Lili Yin
- State Key Laboratory of Membrane Biology and Beijing Key Laboratory of Cardiometabolic Molecular MedicineInstitute of Molecular MedicineCollege of Future TechnologyPeking‐Tsinghua Center for Life Sciences, and PKU‐IDG/McGovern Institute for Brain ResearchPeking UniversityBeijing100871China
| | - Xiaohan Jiang
- State Key Laboratory of Membrane Biology and Beijing Key Laboratory of Cardiometabolic Molecular MedicineInstitute of Molecular MedicineCollege of Future TechnologyPeking‐Tsinghua Center for Life Sciences, and PKU‐IDG/McGovern Institute for Brain ResearchPeking UniversityBeijing100871China
| | - Xingyu Du
- State Key Laboratory of Membrane Biology and Beijing Key Laboratory of Cardiometabolic Molecular MedicineInstitute of Molecular MedicineCollege of Future TechnologyPeking‐Tsinghua Center for Life Sciences, and PKU‐IDG/McGovern Institute for Brain ResearchPeking UniversityBeijing100871China
| | - Zhongjun Qiao
- State Key Laboratory of Membrane Biology and Beijing Key Laboratory of Cardiometabolic Molecular MedicineInstitute of Molecular MedicineCollege of Future TechnologyPeking‐Tsinghua Center for Life Sciences, and PKU‐IDG/McGovern Institute for Brain ResearchPeking UniversityBeijing100871China
| | - Feipeng Zhu
- State Key Laboratory of Membrane Biology and Beijing Key Laboratory of Cardiometabolic Molecular MedicineInstitute of Molecular MedicineCollege of Future TechnologyPeking‐Tsinghua Center for Life Sciences, and PKU‐IDG/McGovern Institute for Brain ResearchPeking UniversityBeijing100871China
| | - Zhe Zhang
- State Key Laboratory of Membrane Biology and Beijing Key Laboratory of Cardiometabolic Molecular MedicineInstitute of Molecular MedicineCollege of Future TechnologyPeking‐Tsinghua Center for Life Sciences, and PKU‐IDG/McGovern Institute for Brain ResearchPeking UniversityBeijing100871China
| | - Quanfeng Zhang
- State Key Laboratory of Membrane Biology and Beijing Key Laboratory of Cardiometabolic Molecular MedicineInstitute of Molecular MedicineCollege of Future TechnologyPeking‐Tsinghua Center for Life Sciences, and PKU‐IDG/McGovern Institute for Brain ResearchPeking UniversityBeijing100871China
| | - Zhuan Zhou
- State Key Laboratory of Membrane Biology and Beijing Key Laboratory of Cardiometabolic Molecular MedicineInstitute of Molecular MedicineCollege of Future TechnologyPeking‐Tsinghua Center for Life Sciences, and PKU‐IDG/McGovern Institute for Brain ResearchPeking UniversityBeijing100871China
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6
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Ishii J, Sato-Yazawa H, Kashiwagi K, Nakadate K, Iwamoto M, Kohno K, Miyata-Hiramatsu C, Masawa M, Onozaki M, Noda S, Miyazawa T, Takagi M, Yazawa T. Endocrine secretory granule production is caused by a lack of REST and intragranular secretory content and accelerated by PROX1. J Mol Histol 2022; 53:437-448. [PMID: 35094211 PMCID: PMC9117388 DOI: 10.1007/s10735-021-10055-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Accepted: 12/23/2021] [Indexed: 12/30/2022]
Abstract
Endocrine secretory granules (ESGs) are morphological characteristics of endocrine/neuroendocrine cells and store peptide hormones/neurotransmitters. ESGs contain prohormones and ESG-related molecules, mainly chromogranin/secretogranin family proteins. However, the precise mechanism of ESG formation has not been elucidated. In this study, we experimentally induced ESGs in the non-neuroendocrine lung cancer cell line H1299. Since repressive element 1 silencing transcription factor (REST) and prospero homeobox 1 (PROX1) are closely associated with the expression of ESG-related molecules, we edited the REST gene and/or transfected PROX1 and then performed molecular biology, immunocytochemistry, and electron and immunoelectron microscopy assays to determine whether ESG-related molecules and ESGs were induced in H1299 cells. Although chromogranin/secretogranin family proteins were induced in H1299 cells by knockout of REST and the induction was accelerated by the PROX1 transgene, the ESGs could not be defined by electron microscopy. However, a small number of ESGs were detected in the H1299 cells lacking REST and expressing pro-opiomelanocortin (POMC) by electron microscopy. Furthermore, many ESGs were produced in the REST-lacking and PROX1- and POMC-expressing H1299 cells. These findings suggest that a lack of REST and the expression of genes related to ESG content are indispensable for ESG production and that PROX1 accelerates ESG production. Trial registration: Not applicable.
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Affiliation(s)
- Jun Ishii
- Department of Pathology, Dokkyo Medical University School of Medicine and Graduate School of Medicine, Mibu-machi, Tochigi, Japan
| | - Hanako Sato-Yazawa
- Department of Pathology, Dokkyo Medical University School of Medicine and Graduate School of Medicine, Mibu-machi, Tochigi, Japan
| | - Korehito Kashiwagi
- Department of Pathology, Dokkyo Medical University School of Medicine and Graduate School of Medicine, Mibu-machi, Tochigi, Japan
| | - Kazuhiko Nakadate
- Education Research Center, Meiji Pharmaceutical University, Kiyose-shi, Tokyo, Japan
| | - Masami Iwamoto
- Department of Pathology, Dokkyo Medical University School of Medicine and Graduate School of Medicine, Mibu-machi, Tochigi, Japan
- Department of Pathology, The Jikei University, Minato-ku, Tokyo, Japan
| | - Kakeru Kohno
- Department of Pathology, Dokkyo Medical University School of Medicine and Graduate School of Medicine, Mibu-machi, Tochigi, Japan
- Institute of Life Innovation Studies, Toyo University, Itakura-machi, Gunma, Japan
| | - Chie Miyata-Hiramatsu
- Department of Pathology, Dokkyo Medical University School of Medicine and Graduate School of Medicine, Mibu-machi, Tochigi, Japan
| | - Meitetsu Masawa
- Department of Respiratory Medicine, Dokkyo Medical University School of Medicine and Graduate School of Medicine, Mibu-machi, Tochigi, Japan
| | - Masato Onozaki
- Department of Diagnostic Pathology, Dokkyo Medical University School of Medicine and Graduate School of Medicine, Mibu-machi, Tochigi, Japan
| | - Shuhei Noda
- Department of Diagnostic Pathology, Dokkyo Medical University School of Medicine and Graduate School of Medicine, Mibu-machi, Tochigi, Japan
| | - Tadasuke Miyazawa
- Department of Pathology, Dokkyo Medical University School of Medicine and Graduate School of Medicine, Mibu-machi, Tochigi, Japan
| | - Megumi Takagi
- Department of Pathology, Dokkyo Medical University School of Medicine and Graduate School of Medicine, Mibu-machi, Tochigi, Japan
| | - Takuya Yazawa
- Department of Pathology, Dokkyo Medical University School of Medicine and Graduate School of Medicine, Mibu-machi, Tochigi, Japan.
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7
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Reck J, Beuret N, Demirci E, Prescianotto-Baschong C, Spiess M. Small disulfide loops in peptide hormones mediate self-aggregation and secretory granule sorting. Life Sci Alliance 2022; 5:5/5/e202101279. [PMID: 35086936 PMCID: PMC8807871 DOI: 10.26508/lsa.202101279] [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: 10/27/2021] [Revised: 01/12/2022] [Accepted: 01/14/2022] [Indexed: 11/24/2022] Open
Abstract
Unlike constitutively secreted proteins, peptide hormones are stored in densely packed secretory granules, before regulated release upon stimulation. Secretory granules are formed at the TGN by self-aggregation of prohormones as functional amyloids. The nonapeptide hormone vasopressin, which forms a small disulfide loop, was shown to be responsible for granule formation of its precursor in the TGN as well as for toxic fibrillar aggregation of unfolded mutants in the ER. Several other hormone precursors also contain similar small disulfide loops suggesting their function as a general device to mediate aggregation for granule sorting. To test this hypothesis, we studied the capacity of small disulfide loops of different hormone precursors to mediate aggregation in the ER and the TGN. They indeed induced ER aggregation in Neuro-2a and COS-1 cells. Fused to a constitutively secreted reporter protein, they also promoted sorting into secretory granules, enhanced stimulated secretion, and increased Lubrol insolubility in AtT20 cells. These results support the hypothesis that small disulfide loops act as novel signals for sorting into secretory granules by self-aggregation.
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8
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Wang H, Yin J, Hong Y, Ren A, Wang H, Li M, Zhao Q, Jiang C, Liu L. SCG2 is a Prognostic Biomarker Associated With Immune Infiltration and Macrophage Polarization in Colorectal Cancer. Front Cell Dev Biol 2022; 9:795133. [PMID: 35047505 PMCID: PMC8763391 DOI: 10.3389/fcell.2021.795133] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Accepted: 12/01/2021] [Indexed: 12/24/2022] Open
Abstract
Colorectal cancer (CRC) is the second most lethal malignancy around the world. Limited efficacy of immunotherapy creates an urgent need for development of novel treatment targets. Secretogranin II (SCG2) is a member of the chromogranin family of acidic secretory proteins, has a role in tumor microenvironment (TME) of lung adenocarcinoma and bladder cancer. Besides, SCG2 is a stroma-related gene in CRC, its potential function in regulating tumor immune infiltration of CRC needs to be fully elucidated. In this study, we used western blot, real-time PCR, immunofluorescence and public databases to evaluate SCG2 expression levels and distribution. Survival analysis and functional enrichment analysis were performed. We examined TME and tumor infiltrating immune cells using ESTIMATE and CIBERSORT algorithm. The results showed that SCG2 expression was significantly decreased in CRC tumor tissues, and differentially distributed between tumor and adjacent normal tissues. SCG2 was an independent prognostic predictor in CRC. High expression of SCG2 correlated with poor survival and advanced clinical stage in CRC patients. SCG2 might regulate multiple tumor- and immune-related pathways in CRC, influence tumor immunity by regulating infiltration of immune cells and macrophage polarization in CRC.
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Affiliation(s)
- Hao Wang
- Department of Oncology, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, China.,Hubei Clinical Center and Key Lab of Intestinal and Colorectal Diseases, Wuhan, China
| | - Jinwen Yin
- Hubei Clinical Center and Key Lab of Intestinal and Colorectal Diseases, Wuhan, China.,Department of Gastroenterology, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Yuntian Hong
- Hubei Clinical Center and Key Lab of Intestinal and Colorectal Diseases, Wuhan, China.,Department of Colorectal and Anal Surgery, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Anli Ren
- Hubei Clinical Center and Key Lab of Intestinal and Colorectal Diseases, Wuhan, China.,Department of Gastroenterology, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Haizhou Wang
- Hubei Clinical Center and Key Lab of Intestinal and Colorectal Diseases, Wuhan, China.,Department of Gastroenterology, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Mengting Li
- Hubei Clinical Center and Key Lab of Intestinal and Colorectal Diseases, Wuhan, China.,Department of Gastroenterology, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Qiu Zhao
- Hubei Clinical Center and Key Lab of Intestinal and Colorectal Diseases, Wuhan, China.,Department of Gastroenterology, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Congqing Jiang
- Hubei Clinical Center and Key Lab of Intestinal and Colorectal Diseases, Wuhan, China.,Department of Colorectal and Anal Surgery, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Lan Liu
- Hubei Clinical Center and Key Lab of Intestinal and Colorectal Diseases, Wuhan, China.,Department of Gastroenterology, Zhongnan Hospital of Wuhan University, Wuhan, China
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9
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Ford C, Parchure A, von Blume J, Burd CG. Cargo sorting at the trans-Golgi network at a glance. J Cell Sci 2021; 134:jcs259110. [PMID: 34870705 PMCID: PMC8714066 DOI: 10.1242/jcs.259110] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The Golgi functions principally in the biogenesis and trafficking of glycoproteins and lipids. It is compartmentalized into multiple flattened adherent membrane sacs termed cisternae, which each contain a distinct repertoire of resident proteins, principally enzymes that modify newly synthesized proteins and lipids sequentially as they traffic through the stack of Golgi cisternae. Upon reaching the final compartments of the Golgi, the trans cisterna and trans-Golgi network (TGN), processed glycoproteins and lipids are packaged into coated and non-coated transport carriers derived from the trans Golgi and TGN. The cargoes of clathrin-coated vesicles are chiefly residents of endo-lysosomal organelles, while uncoated carriers ferry cargo to the cell surface. There are outstanding questions regarding the mechanisms of protein and lipid sorting within the Golgi for export to different organelles. Nonetheless, conceptual advances have begun to define the key molecular features of cargo clients and the mechanisms underlying their sorting into distinct export pathways, which we have collated in this Cell Science at a Glance article and the accompanying poster.
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Affiliation(s)
| | | | - Julia von Blume
- Department of Cell Biology, Yale School of Medicine, Yale University, New Haven, CT 06520, USA
| | - Christopher G. Burd
- Department of Cell Biology, Yale School of Medicine, Yale University, New Haven, CT 06520, USA
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10
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Abeyratne-Perera HK, Basu S, Chandran PL. Shells of compacted DNA as nanocontainers transporting proteins in multiplexed delivery. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2021; 127:112184. [PMID: 34225845 DOI: 10.1016/j.msec.2021.112184] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 05/04/2021] [Accepted: 05/07/2021] [Indexed: 11/24/2022]
Abstract
Polyethyleneimine (PEI) polymers are known to compact DNA strands into spheroid, toroid, or rod structures. A formulation with mannose-grafted PEI (PEIm), however, was reported to compact DNA into ~100 nm spheroids that indented like thin-walled pressurized shells. The goal of the study is to understand why mannose bristles divert the traditional pathway of PEI-DNA compaction to produce shell-like structures, and to manipulate the process so that proteins can be packed into the core of the assembling shells for co-delivering DNA and proteins into cells. DLS, AFM, and TEM imaging provide a consistent picture that BSA proteins can be packed into the shells without altering the shell architecture, as long as the proteins were added during the time course of shell assembly. Force spectroscopy studies reveal that DNA shells that buckle also have a rich surface-coating of mannose, indicating that a micelle-like partitioning of hydrophobic and hydrophilic layers governs shell assembly. When HEK293T cells are spiked with BSA-laden DNA shells, co-transfection of DNA and BSA is observed at higher levels than control formulations. Distinct micron-sized features appear having both green fluorescence from BSA-FITC and blue fluorescence from NucBlue DNA stain, suggesting BSA release in nucleus and secretory granules. With DNA nanocontainers, proteins can take advantage of the efficiency of PEI-based DNA transfection for hitchhiking into cells while being shielded from the challenges of the intracellular route. DNA nanocontainers are rapid to assemble, not dependent on the DNA sequence, and can be adapted for different protein types; thereby having potential to serve as a high-throughput platform in scenarios where DNA and protein have to be released at the same site and time within cells (e.g., theranostics, multiplexed co-delivery, gene editing).
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Affiliation(s)
- Hashanthi K Abeyratne-Perera
- Biochemistry and Molecular Biology Department, College of Medicine, Howard University, Washington, DC, United States of America
| | - Saswati Basu
- Chemical Engineering Department, College of Engineering and Architecture, Howard University, Washington, DC, United States of America
| | - Preethi L Chandran
- Biochemistry and Molecular Biology Department, College of Medicine, Howard University, Washington, DC, United States of America; Chemical Engineering Department, College of Engineering and Architecture, Howard University, Washington, DC, United States of America.
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11
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Ma CIJ, Burgess J, Brill JA. Maturing secretory granules: Where secretory and endocytic pathways converge. Adv Biol Regul 2021; 80:100807. [PMID: 33866198 DOI: 10.1016/j.jbior.2021.100807] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 03/10/2021] [Accepted: 03/18/2021] [Indexed: 10/21/2022]
Abstract
Secretory granules (SGs) are specialized organelles responsible for the storage and regulated release of various biologically active molecules from the endocrine and exocrine systems. Thus, proper SG biogenesis is critical to normal animal physiology. Biogenesis of SGs starts at the trans-Golgi network (TGN), where immature SGs (iSGs) bud off and undergo maturation before fusing with the plasma membrane (PM). How iSGs mature is unclear, but emerging studies have suggested an important role for the endocytic pathway. The requirement for endocytic machinery in SG maturation blurs the line between SGs and another class of secretory organelles called lysosome-related organelles (LROs). Therefore, it is important to re-evaluate the differences and similarities between SGs and LROs.
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Affiliation(s)
- Cheng-I Jonathan Ma
- Cell Biology Program, The Hospital for Sick Children, PGCRL Building, Room 15.9716, 686 Bay Street, Toronto, Ontario, M5G 0A4, Canada; Institute of Medical Science, University of Toronto, Medical Sciences Building, Room 2374, 1 King's College Circle, Toronto, Ontario, M5S 1A8, Canada
| | - Jason Burgess
- Cell Biology Program, The Hospital for Sick Children, PGCRL Building, Room 15.9716, 686 Bay Street, Toronto, Ontario, M5G 0A4, Canada; Department of Molecular Genetics, University of Toronto, Medical Sciences Building, Room 4396, 1 King's College Circle, Toronto, Ontario, M5S 1A8, Canada
| | - Julie A Brill
- Cell Biology Program, The Hospital for Sick Children, PGCRL Building, Room 15.9716, 686 Bay Street, Toronto, Ontario, M5G 0A4, Canada; Institute of Medical Science, University of Toronto, Medical Sciences Building, Room 2374, 1 King's College Circle, Toronto, Ontario, M5S 1A8, Canada; Department of Molecular Genetics, University of Toronto, Medical Sciences Building, Room 4396, 1 King's College Circle, Toronto, Ontario, M5S 1A8, Canada.
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12
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Insulin granule biogenesis and exocytosis. Cell Mol Life Sci 2020; 78:1957-1970. [PMID: 33146746 PMCID: PMC7966131 DOI: 10.1007/s00018-020-03688-4] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 09/11/2020] [Accepted: 10/19/2020] [Indexed: 02/06/2023]
Abstract
Insulin is produced by pancreatic β-cells, and once released to the blood, the hormone stimulates glucose uptake and suppresses glucose production. Defects in both the availability and action of insulin lead to elevated plasma glucose levels and are major hallmarks of type-2 diabetes. Insulin is stored in secretory granules that form at the trans-Golgi network. The granules undergo extensive modifications en route to their release sites at the plasma membrane, including changes in both protein and lipid composition of the granule membrane and lumen. In parallel, the insulin molecules also undergo extensive modifications that render the hormone biologically active. In this review, we summarize current understanding of insulin secretory granule biogenesis, maturation, transport, docking, priming and eventual fusion with the plasma membrane. We discuss how different pools of granules form and how these pools contribute to insulin secretion under different conditions. We also highlight the role of the β-cell in the development of type-2 diabetes and discuss how dysregulation of one or several steps in the insulin granule life cycle may contribute to disease development or progression.
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13
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Fujita-Yoshigaki J, Yokoyama M, Katsumata-Kato O. Switching of cargo sorting from the constitutive to regulated secretory pathway by the addition of cystatin D sequence in salivary acinar cells. Am J Physiol Gastrointest Liver Physiol 2020; 319:G74-G86. [PMID: 32538138 DOI: 10.1152/ajpgi.00103.2020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The mechanism for segregation of cargo proteins into the regulated and constitutive secretory pathways in exocrine cells remains to be elucidated. We examined the transport of HaloTag proteins fused with full-length cystatin D (fCst5-Halo) or only its signal peptide (ssCst5-Halo) in parotid acinar cells. Although both fusion proteins were observed to be colocalized with amylase in the secretory granules, the coefficients for overlapping and correlation of fCst5-Halo with amylase were higher than those of ssCst5-Halo. The secretion of both the proteins was enhanced by the addition of the β-adrenergic receptor agonist isoproterenol as well as endogenous amylase. In contrast, unstimulated secretion of ssCst5-Halo without isoproterenol was significantly higher than that of fCst5-Halo and amylase. Simulation analysis using a mathematical model revealed that a large proportion of ssCst5-Halo was secreted through the constitutive pathway, whereas fCst5-Halo was transported into the secretory granules more efficiently. Precipitation of fCst5-Halo from cell lysates was increased at a low pH, which may mimic the milieu of the trans-Golgi networks. These data suggest that the addition of a full-length sequence of cystatin D facilitates efficient selective transport into the regulated pathway by aggregation at low pH in the trans-Golgi network.NEW & NOTEWORTHY The mechanism underlying the segregation of cargo proteins to the regulated and constitutive secretory pathways in exocrine cells remains to be solved. We analyzed unstimulated secretion in salivary acinar cells by performing double-labeling experiments using HaloTag technology and computer simulation. It revealed that the majority of HaloTag with only signal peptide sequence was secreted through the constitutive pathway and that the addition of a full-length cystatin D sequence changed its sorting to the regulated pathway.
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Affiliation(s)
- Junko Fujita-Yoshigaki
- Department of Physiology, Nihon University School of Dentistry at Matsudo, Matsudo, Chiba, Japan.,Research Institute of Oral Science, Nihon University School of Dentistry at Matsudo, Matsudo, Chiba, Japan
| | - Megumi Yokoyama
- Department of Physiology, Nihon University School of Dentistry at Matsudo, Matsudo, Chiba, Japan.,Research Institute of Oral Science, Nihon University School of Dentistry at Matsudo, Matsudo, Chiba, Japan
| | - Osamu Katsumata-Kato
- Department of Physiology, Nihon University School of Dentistry at Matsudo, Matsudo, Chiba, Japan.,Research Institute of Oral Science, Nihon University School of Dentistry at Matsudo, Matsudo, Chiba, Japan
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14
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Newly Identified Regulators of Ovarian Folliculogenesis and Ovulation. Int J Mol Sci 2020; 21:ijms21124565. [PMID: 32604954 PMCID: PMC7349727 DOI: 10.3390/ijms21124565] [Citation(s) in RCA: 80] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 06/19/2020] [Accepted: 06/23/2020] [Indexed: 02/06/2023] Open
Abstract
Each follicle represents the basic functional unit of the ovary. From its very initial stage of development, the follicle consists of an oocyte surrounded by somatic cells. The oocyte grows and matures to become fertilizable and the somatic cells proliferate and differentiate into the major suppliers of steroid sex hormones as well as generators of other local regulators. The process by which a follicle forms, proceeds through several growing stages, develops to eventually release the mature oocyte, and turns into a corpus luteum (CL) is known as “folliculogenesis”. The task of this review is to define the different stages of folliculogenesis culminating at ovulation and CL formation, and to summarize the most recent information regarding the newly identified factors that regulate the specific stages of this highly intricated process. This information comprises of either novel regulators involved in ovarian biology, such as Ube2i, Phoenixin/GPR73, C1QTNF, and α-SNAP, or recently identified members of signaling pathways previously reported in this context, namely PKB/Akt, HIPPO, and Notch.
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15
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Amyloid-like aggregation of provasopressin. VITAMINS AND HORMONES 2020. [PMID: 32138954 DOI: 10.1016/bs.vh.2019.08.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/09/2023]
Abstract
The antidiuretic hormone vasopressin is synthesized as a longer precursor protein. After folding in the endoplasmic reticulum (ER), provasopressin is transported through the secretory pathway, forms secretory granules in the trans-Golgi network (TGN), is processed, and finally secreted into the circulation. Mutations in provasopressin cause autosomal dominant diabetes insipidus. They prevent native protein folding and cause fibrillar, amyloid-like aggregation in the ER, which eventually results in cell death. Secretory granules of peptide hormones were proposed to constitute functional amyloids and thus might be the cause of amyloid formation of misfolded mutant protein in the ER. Indeed, the same two segments in the precursor-vasopressin and a C-terminal glycopeptide-were found to be responsible for pathological aggregation in the ER and physiological aggregation in granule formation in the TGN. Furthermore, even wild-type provasopressin tends to aggregate in the ER, but is controlled by ER-associated degradation. When essential components thereof, Sel1L or Hrd1, were inactivated, wild-type provasopressin accumulated as fibrillar aggregates in vasopressinergic neurons in mice, causing diabetes insipidus. Evolution of amyloidogenic sequences for granule formation thus made provasopressin dependent on ER quality control mechanisms. These principles may similarly apply to other peptide hormones.
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16
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Abstract
When protein/peptides aggregate, they usually form the amyloid state consisting of cross β-sheet structure built by repetitively stacked β-strands forming long fibrils. Amyloids are usually associated with disease including Alzheimer's. However, amyloid has many useful features. It efficiently transforms protein from the soluble to the insoluble state in an essentially two-state process, while its repetitive structure provides high stability and a robust prion-like replication mechanism. Accordingly, amyloid is used by nature in multifaceted and ingenious ways of life, ranging from bacteria and fungi to mammals. These include (1) Structure: Templating for small chemical molecules (Pmel17), biofilm formation in bacteria (curli), assisting aerial hyphae formation in streptomycetes (chaplins) or monolayer formation at a surface (hydrophobins). (2) Reservoirs: A storage state for peptide/proteins to protect them from their surroundings or vice versa (storage of peptide hormones in mammalian secretory granules or major basic protein in eosinophils). (3) Information carriers: The fungal immune system (HET-s prion in Podospora anserina, yeast prions) or long-term memory (e.g., mnemons in yeast, cytoplasmic polyadenylation element-binding protein in aplysia). Aggregation is also used to (4) "suppress" the function of the soluble protein (e.g., Cdc19 in yeast stress granules), or (5) "signaling" through formation of oligomers (e.g., HET-s prion, necroptosis-related proteins RIP1/RIP3). This review summarizes current knowledge on functional amyloids with a focus on the amyloid systems curli in bacteria, HET-s prion in P. anserina, and peptide hormone storage in mammals together with an attempt to highlight differences between functional and disease-associated amyloids.
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Affiliation(s)
- Daniel Otzen
- iNANO, Aarhus University, DK-8000 Aarhus C, Denmark
| | - Roland Riek
- Laboratory of Physical Chemistry, Swiss Federal Institute of Technology, CH-8093 Zürich, Switzerland
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17
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Hannon PR, Duffy DM, Rosewell KL, Brännström M, Akin JW, Curry TE. Ovulatory Induction of SCG2 in Human, Nonhuman Primate, and Rodent Granulosa Cells Stimulates Ovarian Angiogenesis. Endocrinology 2018; 159:2447-2458. [PMID: 29648638 PMCID: PMC6287591 DOI: 10.1210/en.2018-00020] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Accepted: 04/02/2018] [Indexed: 02/06/2023]
Abstract
The luteinizing hormone (LH) surge is essential for ovulation, but the intrafollicular factors induced by LH that mediate ovulatory processes (e.g., angiogenesis) are poorly understood, especially in women. The role of secretogranin II (SCG2) and its cleaved bioactive peptide, secretoneurin (SN), were investigated as potential mediators of ovulation by testing the hypothesis that SCG2/SN is induced in granulosa cells by human chorionic gonadotropin (hCG), via a downstream LH receptor signaling mechanism, and stimulates ovarian angiogenesis. Humans, nonhuman primates, and rodents were treated with hCG in vivo resulting in a significant increase in the messenger RNA and protein levels of SCG2 in granulosa cells collected early during the periovulatory period and just prior to ovulation (humans: 12 to 34 hours; monkeys: 12 to 36 hours; rodents: 4 to 12 hours post-hCG). This induction by hCG was recapitulated in an in vitro culture system utilizing granulosa-lutein cells from in vitro fertilization patients. Using this system, inhibition of downstream LH receptor signaling pathways revealed that the initial induction of SCG2 is regulated, in part, by epidermal growth factor receptor signaling. Further, human ovarian microvascular endothelial cells were treated with SN (1 to 100 ng/mL) and subjected to angiogenesis assays. SN significantly increased endothelial cell migration and new sprout formation, suggesting induction of ovarian angiogenesis. These results establish that SCG2 is increased in granulosa cells across species during the periovulatory period and that SN may mediate ovulatory angiogenesis in the human ovary. These findings provide insight into the regulation of human ovulation and fertility.
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Affiliation(s)
- Patrick R Hannon
- Department of Obstetrics and Gynecology, University of Kentucky, Lexington,
Kentucky
| | - Diane M Duffy
- Department of Physiological Sciences, Eastern Virginia Medical School, Norfolk,
Virginia
| | - Katherine L Rosewell
- Department of Obstetrics and Gynecology, University of Kentucky, Lexington,
Kentucky
| | - Mats Brännström
- Department of Obstetrics and Gynecology, Sahlgrenska Academy, University of
Gothenburg, Gothenburg, Sweden
| | | | - Thomas E Curry
- Department of Obstetrics and Gynecology, University of Kentucky, Lexington,
Kentucky
- Correspondence: Thomas E. Curry, Jr., PhD, Department of Obstetrics and Gynecology, University of
Kentucky, 800 Rose Street, Room C351, Lexington, Kentucky 40536. E-mail:
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18
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Ohshima H. Oral biosciences: The annual review 2017. J Oral Biosci 2018. [DOI: 10.1016/j.job.2017.12.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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19
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Ohta A, Tsunoda Y, Tamura Y, Iino K, Nishimura N, Nishihara H, Takanashi H, Yoshida S, Kato T, Kato Y. Construction and expression of vectors encoding biologically active rodent gonadotropins. J Reprod Dev 2017; 63:605-609. [PMID: 29033405 PMCID: PMC5735272 DOI: 10.1262/jrd.2017-091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The gonadotropins, luteinizing hormone (LH) and follicle-stimulating hormone (FSH), are important hormones in vertebrate reproduction. The isolation of gonadotropins from the pituitary gland is sub-optimal, as the cross-contamination of one hormone with another is common and often results in the variation in the measured activity of LH and FSH. The production of recombinant hormones is, therefore, a viable approach to solve this problem. This study aimed to express recombinant rat, mouse, and mastomys FSH and LH in Chinese hamster ovary (CHO) cells. Their common α-subunits along with their hormone-specific β-subunits were encoded in a single mammalian expression vector. FSH from all three species was expressed, whereas expression was achieved only for the mouse LH. Immunohistochemistry for rat alpha subunit of glycoprotein hormone (αGSU) and LHβ and FSHβ subunits confirmed the production of the dimeric hormone in CHO cells. The recombinant rodent gonadotropins were confirmed to be biologically active; estradiol production was increased by recombinant FSH in granulosa cells, while recombinant LH increased testosterone production in Leydig cells.
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Affiliation(s)
- Akihiko Ohta
- Division of Life Science, Graduate School of Agriculture, Meiji University, Kanagawa 214-8571, Japan.,Institute for Reproduction and Endocrinology, Meiji University, Kanagawa 214-8571, Japan.,Department of Life Science, Meiji University, Kanagawa 214-8571, Japan
| | - Yuichiro Tsunoda
- Division of Life Science, Graduate School of Agriculture, Meiji University, Kanagawa 214-8571, Japan
| | - Yoshihiko Tamura
- Division of Life Science, Graduate School of Agriculture, Meiji University, Kanagawa 214-8571, Japan
| | - Kayoko Iino
- Division of Life Science, Graduate School of Agriculture, Meiji University, Kanagawa 214-8571, Japan
| | - Naoto Nishimura
- Division of Life Science, Graduate School of Agriculture, Meiji University, Kanagawa 214-8571, Japan
| | - Hiroto Nishihara
- Division of Life Science, Graduate School of Agriculture, Meiji University, Kanagawa 214-8571, Japan
| | - Haruka Takanashi
- Division of Life Science, Graduate School of Agriculture, Meiji University, Kanagawa 214-8571, Japan
| | - Saishu Yoshida
- Division of Life Science, Graduate School of Agriculture, Meiji University, Kanagawa 214-8571, Japan.,Institute for Reproduction and Endocrinology, Meiji University, Kanagawa 214-8571, Japan
| | - Takako Kato
- Institute for Reproduction and Endocrinology, Meiji University, Kanagawa 214-8571, Japan
| | - Yukio Kato
- Division of Life Science, Graduate School of Agriculture, Meiji University, Kanagawa 214-8571, Japan.,Institute for Reproduction and Endocrinology, Meiji University, Kanagawa 214-8571, Japan.,Department of Life Science, Meiji University, Kanagawa 214-8571, Japan
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20
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Determinants for selective transport of exogenously expressed cargo proteins into regulated and constitutive secretory pathways. J Oral Biosci 2017. [DOI: 10.1016/j.job.2017.01.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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21
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Zhao Y, Zhong X, Ou X, Cai H, Wu X, Huang R. Cotransfecting norepinephrine transporter and vesicular monoamine transporter 2 genes for increased retention of metaiodobenzylguanidine labeled with iodine 131 in malignant hepatocarcinoma cells. Front Med 2017; 11:120-128. [PMID: 28213878 DOI: 10.1007/s11684-017-0501-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Accepted: 11/24/2016] [Indexed: 02/05/2023]
Abstract
Norepinephrine transporter (NET) transfection leads to significant uptake of iodine-131-labeled metaiodobenzylguanidine (131I-MIBG) in non-neuroendocrine tumors. However, the use of 131I-MIBG is limited by its short retention time in target cells. To prolong the retention of 131I-MIBG in target cells, we infected hepatocarcinoma (HepG2) cells with Lentivirus-encoding human NET and vesicular monoamine transporter 2 (VMAT2) genes to obtain NET-expressing, NET-VMAT2-coexpressing, and negative-control cell lines. We evaluated the uptake and efflux of 131I-MIBG both in vitro and in vivo in mice bearing transfected tumors. NET-expressing and NET-VMAT2-coexpressing cells respectively showed 2.24 and 2.22 times higher 131I-MIBG uptake than controls. Two hours after removal of 131I-MIBG-containing medium, 25.4% efflux was observed in NET-VMAT2-coexpressing cells and 38.6% in NET-expressing cells. In vivo experiments were performed in nude mice bearing transfected tumors; results revealed that NET-VMAT2-coexpressing tumors had longer 131I-MIBG retention time than NET-expressing tumors. Meanwhile, NET-VMAT2-coexpressing and NET-expressing tumors displayed 0.54% and 0.19%, respectively, of the injected dose per gram of tissue 24 h after 131I-MIBG administration. Cotransfection of HepG2 cells with NET and VMAT2 resulted in increased 131I-MIBG uptake and retention. However, the degree of increase was insufficient to be therapeutically effective in target cells.
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Affiliation(s)
- Yanlin Zhao
- Department of Nuclear Medicine, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Xiao Zhong
- Department of Nuclear Medicine, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Xiaohong Ou
- Department of Nuclear Medicine, West China Hospital, Sichuan University, Chengdu, 610041, China.
| | - Huawei Cai
- Department of Nuclear Medicine, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Xiaoai Wu
- Department of Nuclear Medicine, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Rui Huang
- Department of Nuclear Medicine, West China Hospital, Sichuan University, Chengdu, 610041, China
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22
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Beuret N, Hasler F, Prescianotto-Baschong C, Birk J, Rutishauser J, Spiess M. Amyloid-like aggregation of provasopressin in diabetes insipidus and secretory granule sorting. BMC Biol 2017; 15:5. [PMID: 28122547 PMCID: PMC5267430 DOI: 10.1186/s12915-017-0347-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Accepted: 01/04/2017] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND Aggregation of peptide hormone precursors in the trans-Golgi network is an essential process in the biogenesis of secretory granules in endocrine cells. It has recently been proposed that this aggregation corresponds to the formation of functional amyloids. Our previous finding that dominant mutations in provasopressin, which cause cell degeneration and diabetes insipidus, prevent native folding and produce fibrillar aggregates in the endoplasmic reticulum (ER) might thus reflect mislocalized amyloid formation by sequences that evolved to mediate granule sorting. RESULTS Here we identified two sequences responsible for fibrillar aggregation of mutant precursors in the ER: the N-terminal vasopressin nonapeptide and the C-terminal glycopeptide. To test their role in granule sorting, the glycopeptide was deleted and/or vasopressin mutated to inactivate ER aggregation while still permitting precursor folding and ER exit. These mutations strongly reduced sorting into granules and regulated secretion in endocrine AtT20 cells. CONCLUSION The same sequences - vasopressin and the glycopeptide - mediate physiological aggregation of the wild-type hormone precursor into secretory granules and the pathological fibrillar aggregation of disease mutants in the ER. These findings support the amyloid hypothesis for secretory granule biogenesis.
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Affiliation(s)
- Nicole Beuret
- Biozentrum, University of Basel, Klingelbergstrasse 70, CH-4056, Basel, Switzerland
| | - Franziska Hasler
- Biozentrum, University of Basel, Klingelbergstrasse 70, CH-4056, Basel, Switzerland
| | | | - Julia Birk
- Biozentrum, University of Basel, Klingelbergstrasse 70, CH-4056, Basel, Switzerland
| | - Jonas Rutishauser
- Biozentrum, University of Basel, Klingelbergstrasse 70, CH-4056, Basel, Switzerland
| | - Martin Spiess
- Biozentrum, University of Basel, Klingelbergstrasse 70, CH-4056, Basel, Switzerland.
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23
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Yamamoto H, Ramos-Molina B, Lick AN, Prideaux M, Albornoz V, Bonewald L, Lindberg I. Posttranslational processing of FGF23 in osteocytes during the osteoblast to osteocyte transition. Bone 2016; 84:120-130. [PMID: 26746780 PMCID: PMC4755901 DOI: 10.1016/j.bone.2015.12.055] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Revised: 12/04/2015] [Accepted: 12/09/2015] [Indexed: 11/29/2022]
Abstract
FGF23 is an O-glycosylated circulating peptide hormone with a critical role in phosphate homeostasis; it is inactivated by cellular proprotein convertases in a pre-release degradative pathway. We have here examined the metabolism of FGF23 in a model bone cell line, IDG-SW3, prior to and following differentiation, as well as in regulated secretory cells. Labeling experiments showed that the majority of (35)S-labeled FGF23 was cleaved to smaller fragments which were constitutively secreted by all cell types. Intact FGF23 was much more efficiently stored in differentiated than in undifferentiated IDG-SW3 cells. The prohormone convertase PC2 has recently been implicated in FGF23 degradation; however, FGF23 was not targeted to forskolin-stimulatable secretory vesicles in a regulated cell line, suggesting that it lacks a targeting signal to PC2-containing compartments. In vitro, PC1/3 and PC2, but not furin, efficiently cleaved glycosylated FGF23; surprisingly, PC5/6 accomplished a small amount of conversion. FGF23 has recently been shown to be phosphorylated by the kinase FAM20C, a process which was shown to reduce FGF23 glycosylation and promote its cleavage; our in vitro data, however, show that phosphorylation does not directly impact cleavage, as both PC5/6 and furin were able to efficiently cleave unglycosylated, phosphorylated FGF23. Using qPCR, we found that the expression of FGF23 and PC5/6, but not PC2 or furin, increased substantially following osteoblast to osteocyte differentiation. Western blotting confirmed the large increase in PC5/6 expression upon differentiation. FGF23 has been linked to a variety of bone disorders ranging from autosomal dominant hypophosphatemic rickets to chronic kidney disease. A better understanding of the biosynthetic pathway of this hormone may lead to new treatments for these diseases.
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Affiliation(s)
- Hiroyuki Yamamoto
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Bruno Ramos-Molina
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Adam N Lick
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Matthew Prideaux
- School of Dentistry, Department of Oral and Craniofacial Sciences, University of Missouri-Kansas City, Kansas City, MO 64108, USA
| | - Valeria Albornoz
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Lynda Bonewald
- School of Dentistry, Department of Oral and Craniofacial Sciences, University of Missouri-Kansas City, Kansas City, MO 64108, USA
| | - Iris Lindberg
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
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Differential Reovirus-Specific and Herpesvirus-Specific Activator Protein 1 Activation of Secretogranin II Leads to Altered Virus Secretion. J Virol 2015; 89:11954-64. [PMID: 26378181 DOI: 10.1128/jvi.01639-15] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Accepted: 09/10/2015] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Viruses utilize host cell machinery for propagation and manage to evade cellular host defense mechanisms in the process. Much remains unknown regarding how the host responds to viral infection. We recently performed global proteomic screens of mammalian reovirus TIL- and T3D-infected and herpesvirus (herpes simplex virus 1 [HSV-1])-infected HEK293 cells. The nonenveloped RNA reoviruses caused an upregulation, whereas the enveloped DNA HSV-1 caused a downregulation, of cellular secretogranin II (SCG2). SCG2, a member of the granin family that functions in hormonal peptide sorting into secretory vesicles, has not been linked to virus infections previously. We confirmed SCG2 upregulation and found SCG2 phosphorylation by 18 h postinfection (hpi) in reovirus-infected cells. We also found a decrease in the amount of reovirus secretion from SCG2 knockdown cells. Similar analyses of cells infected with HSV-1 showed an increase in the amount of secreted virus. Analysis of the stress-activated protein kinase (SAPK)/Jun N-terminal protein kinase (JNK) pathway indicated that each virus activates different pathways leading to activator protein 1 (AP-1) activation, which is the known SCG2 transcription activator. We conclude from these experiments that the negative correlation between SCG2 quantity and virus secretion for both viruses indicates a virus-specific role for SCG2 during infection. IMPORTANCE Mammalian reoviruses affect the gastrointestinal system or cause respiratory infections in humans. Recent work has shown that all mammalian reovirus strains (most specifically T3D) may be useful oncolytic agents. The ubiquitous herpes simplex viruses cause common sores in mucosal areas of their host and have coevolved with hosts over many years. Both of these virus species are prototypical representatives of their viral families, and investigation of these viruses can lead to further knowledge of how they and the other more pathogenic members of their respective families interact with the host. Here we show that secretogranin II (SCG2), a protein not previously studied in the context of virus infections, alters virus output in a virus-specific manner and that the quantity of SCG2 is inversely related to amounts of infectious-virus secretion. Herpesviruses may target this protein to facilitate enhanced virus release from the host.
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25
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Hadžić T, Park D, Abruzzi KC, Yang L, Trigg JS, Rohs R, Rosbash M, Taghert PH. Genome-wide features of neuroendocrine regulation in Drosophila by the basic helix-loop-helix transcription factor DIMMED. Nucleic Acids Res 2015; 43:2199-215. [PMID: 25634895 PMCID: PMC4344488 DOI: 10.1093/nar/gku1377] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Neuroendocrine (NE) cells use large dense core vesicles (LDCVs) to traffic, process, store and secrete neuropeptide hormones through the regulated secretory pathway. The dimmed (DIMM) basic helix-loop-helix transcription factor of Drosophila controls the level of regulated secretory activity in NE cells. To pursue its mechanisms, we have performed two independent genome-wide analyses of DIMM's activities: (i) in vivo chromatin immunoprecipitation (ChIP) to define genomic sites of DIMM occupancy and (ii) deep sequencing of purified DIMM neurons to characterize their transcriptional profile. By this combined approach, we showed that DIMM binds to conserved E-boxes in enhancers of 212 genes whose expression is enriched in DIMM-expressing NE cells. DIMM binds preferentially to certain E-boxes within first introns of specific gene isoforms. Statistical machine learning revealed that flanking regions of putative DIMM binding sites contribute to its DNA binding specificity. DIMM's transcriptional repertoire features at least 20 LDCV constituents. In addition, DIMM notably targets the pro-secretory transcription factor, creb-A, but significantly, DIMM does not target any neuropeptide genes. DIMM therefore prescribes the scale of secretory activity in NE neurons, by a systematic control of both proximal and distal points in the regulated secretory pathway.
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Affiliation(s)
- Tarik Hadžić
- Department of Anatomy and Neurobiology, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, USA
| | - Dongkook Park
- Department of Anatomy and Neurobiology, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, USA
| | - Katharine C Abruzzi
- Howard Hughes Medical Institute, National Center for Behavioral Genomics, Department of Biology, Brandeis University, Waltham, MA 02454, USA
| | - Lin Yang
- Molecular and Computational Biology Program, Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA
| | - Jennifer S Trigg
- Department of Anatomy and Neurobiology, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, USA
| | - Remo Rohs
- Molecular and Computational Biology Program, Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA
| | - Michael Rosbash
- Howard Hughes Medical Institute, National Center for Behavioral Genomics, Department of Biology, Brandeis University, Waltham, MA 02454, USA
| | - Paul H Taghert
- Department of Anatomy and Neurobiology, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, USA
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Pereda D, Pardo MR, Morales Y, Dominguez N, Arnau MR, Borges R. Mice lacking chromogranins exhibit increased aggressive and depression-like behaviour. Behav Brain Res 2014; 278:98-106. [PMID: 25257107 DOI: 10.1016/j.bbr.2014.09.022] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Revised: 09/10/2014] [Accepted: 09/15/2014] [Indexed: 12/14/2022]
Abstract
Chromogranins are acidic proteins; both chromogranins A and B constitute the main protein component in the vesicular matrix of large dense core vesicles. Chromogranins are a natural source of peptides with different physiological activities that have been associated with vascular and neurological diseases. We have used three different genetic mutant models of mice lacking chromogranin A, chromogranin B and both all on the same C57BL/6J background, to characterize the physiological roles of these proteins using metabolic, cardiovascular and behavioural tests. In mice from 3 to 18 months of age, the lack of any chromogranin promoted age-dependent hypersensitivity to insulin, while the lack of both chromogranins provoked progressive lack of response to stress, as restriction did not promote tachycardia in old mice. Moreover, the lack of chromogranin B produced a depressive-like and aggressive phenotype, while the lack either or both chromogranins increased barbering behaviour. In addition, we observed no effects on light-dark box or RotaRod tests. Mice lacking chromogranin B exhibited lower exploratory activity. Based on this extensive phenotyping with more than 2800 mice, these findings support roles of chromogranins, or the peptides derived from them, in the control of aggressive behaviour along with changes in their metabolic profile beyond their previously described activities in the secretory pathway.
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Affiliation(s)
- Daniel Pereda
- Pharmacology Unit, Medical School, University of La Laguna, Tenerife, Spain
| | - Marta R Pardo
- Pharmacology Unit, Medical School, University of La Laguna, Tenerife, Spain
| | - Yezer Morales
- Pharmacology Unit, Medical School, University of La Laguna, Tenerife, Spain
| | - Natalia Dominguez
- Pharmacology Unit, Medical School, University of La Laguna, Tenerife, Spain
| | - Maria Rosa Arnau
- Pharmacology Unit, Medical School, University of La Laguna, Tenerife, Spain
| | - Ricardo Borges
- Pharmacology Unit, Medical School, University of La Laguna, Tenerife, Spain.
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Wampfler PB, Tosevski V, Nanni P, Spycher C, Hehl AB. Proteomics of secretory and endocytic organelles in Giardia lamblia. PLoS One 2014; 9:e94089. [PMID: 24732305 PMCID: PMC3986054 DOI: 10.1371/journal.pone.0094089] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Accepted: 03/10/2014] [Indexed: 11/20/2022] Open
Abstract
Giardia lamblia is a flagellated protozoan enteroparasite transmitted as an environmentally resistant cyst. Trophozoites attach to the small intestine of vertebrate hosts and proliferate by binary fission. They access nutrients directly via uptake of bulk fluid phase material into specialized endocytic organelles termed peripheral vesicles (PVs), mainly on the exposed dorsal side. When trophozoites reach the G2/M restriction point in the cell cycle they can begin another round of cell division or encyst if they encounter specific environmental cues. They induce neogenesis of Golgi-like organelles, encystation-specific vesicles (ESVs), for regulated secretion of cyst wall material. PVs and ESVs are highly simplified and thus evolutionary diverged endocytic and exocytic organelle systems with key roles in proliferation and transmission to a new host, respectively. Both organelle systems physically and functionally intersect at the endoplasmic reticulum (ER) which has catabolic as well as anabolic functions. However, the unusually high degree of sequence divergence in Giardia rapidly exhausts phylogenomic strategies to identify and characterize the molecular underpinnings of these streamlined organelles. To define the first proteome of ESVs and PVs we used a novel strategy combining flow cytometry-based organelle sorting with in silico filtration of mass spectrometry data. From the limited size datasets we retrieved many hypothetical but also known organelle-specific factors. In contrast to PVs, ESVs appear to maintain a strong physical and functional link to the ER including recruitment of ribosomes to organelle membranes. Overall the data provide further evidence for the formation of a cyst extracellular matrix with minimal complexity. The mass spectrometry proteomics data have been deposited to the ProteomeXchange Consortium with the dataset identifier PXD000694.
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Affiliation(s)
- Petra B. Wampfler
- Institute of Parasitology, University of Zurich, Zurich, Switzerland
| | - Vinko Tosevski
- Institute of Experimental Immunology, University of Zurich, Zurich, Switzerland
| | - Paolo Nanni
- Functional Genomics Center Zurich, Zurich, Switzerland
| | - Cornelia Spycher
- Institute of Parasitology, University of Zurich, Zurich, Switzerland
- Institute of Parasitology, University of Bern, Bern, Switzerland
- * E-mail: (ABH); (CS)
| | - Adrian B. Hehl
- Institute of Parasitology, University of Zurich, Zurich, Switzerland
- * E-mail: (ABH); (CS)
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28
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Wang H, Xu S, Sun L, Pan X, Yang S, Wang L. Functional characterization of two low-density lipoprotein receptor gene mutations in two Chinese patients with familial hypercholesterolemia. PLoS One 2014; 9:e92703. [PMID: 24671153 PMCID: PMC3966815 DOI: 10.1371/journal.pone.0092703] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Accepted: 02/24/2014] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Familial hypercholesterolemia (FH) is an autosomal dominant disease that primarily results from mutations in the low-density lipoprotein receptor (LDLR) gene. We investigated two unrelated Chinese FH patients using gene screening and functional analysis to reveal the pathogenicity and the mechanism by which these mutations cause FH. METHODS First, the LDLR gene was sequenced in these patients. Then, mutant receptors were transfected into human embryo kidney 293 (HEK-293) cells, and a confocal laser-scanning microscope was used to observe the localization of mutant proteins. Further, the expression and the internalization activity were analyzed by flow cytometry. Finally, LDLR protein expression and stability was detected by western blot. RESULTS Two different LDLR class 2B mutations were detected in two patients. The C201F mutation is a known mutation. However, the G615V mutation is novel. Flow cytometry showed that the expression and internalization activity of the mutant LDLRs were reduced to 73.6% and 82.6% for G615V and 33.2% and 33.5% for C201F, respectively. CONCLUSIONS This study identified two LDLR mutations in Chinese patients with FH and analyzed the relationship between the genotype and phenotype of these patients. We found that these mutant LDLRs were defective in transport, which led to a reduction in cholesterol clearance. These results increase our understanding of the mutational spectrum of FH in the Chinese population.
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Affiliation(s)
- Haihong Wang
- Department of Atherosclerosis, Beijing Institute of Heart Lung and Blood Vessel Disease, Beijing Anzhen Hospital Affiliated with Capital Medical University, Beijing, China
| | - Shengyuan Xu
- Department of Atherosclerosis, Beijing Institute of Heart Lung and Blood Vessel Disease, Beijing Anzhen Hospital Affiliated with Capital Medical University, Beijing, China
| | - Liyuan Sun
- Department of Atherosclerosis, Beijing Institute of Heart Lung and Blood Vessel Disease, Beijing Anzhen Hospital Affiliated with Capital Medical University, Beijing, China
| | - Xiaodong Pan
- Department of Atherosclerosis, Beijing Institute of Heart Lung and Blood Vessel Disease, Beijing Anzhen Hospital Affiliated with Capital Medical University, Beijing, China
| | - Shiwei Yang
- Department of Atherosclerosis, Beijing Institute of Heart Lung and Blood Vessel Disease, Beijing Anzhen Hospital Affiliated with Capital Medical University, Beijing, China
| | - Luya Wang
- Department of Atherosclerosis, Beijing Institute of Heart Lung and Blood Vessel Disease, Beijing Anzhen Hospital Affiliated with Capital Medical University, Beijing, China
- * E-mail:
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Fargali S, Garcia AL, Sadahiro M, Jiang C, Janssen WG, Lin WJ, Cogliani V, Elste A, Mortillo S, Cero C, Veitenheimer B, Graiani G, Pasinetti GM, Mahata SK, Osborn JW, Huntley GW, Phillips GR, Benson DL, Bartolomucci A, Salton SR. The granin VGF promotes genesis of secretory vesicles, and regulates circulating catecholamine levels and blood pressure. FASEB J 2014; 28:2120-33. [PMID: 24497580 DOI: 10.1096/fj.13-239509] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Secretion of proteins and neurotransmitters from large dense core vesicles (LDCVs) is a highly regulated process. Adrenal LDCV formation involves the granin proteins chromogranin A (CgA) and chromogranin B (CgB); CgA- and CgB-derived peptides regulate catecholamine levels and blood pressure. We investigated function of the granin VGF (nonacronymic) in LDCV formation and the regulation of catecholamine levels and blood pressure. Expression of exogenous VGF in nonendocrine NIH 3T3 fibroblasts resulted in the formation of LDCV-like structures and depolarization-induced VGF secretion. Analysis of germline VGF-knockout mouse adrenal medulla revealed decreased LDCV size in noradrenergic chromaffin cells, increased adrenal norepinephrine and epinephrine content and circulating plasma epinephrine, and decreased adrenal CgB. These neurochemical changes in VGF-knockout mice were associated with hypertension. Germline knock-in of human VGF1-615 into the mouse Vgf locus rescued the hypertensive knockout phenotype, while knock-in of a truncated human VGF1-524 that lacks several C-terminal peptides, including TLQP-21, resulted in a small but significant increase in systolic blood pressure compared to hVGF1-615 mice. Finally, acute and chronic administration of the VGF-derived peptide TLQP-21 to rodents decreased blood pressure. Our studies establish a role for VGF in adrenal LDCV formation and the regulation of catecholamine levels and blood pressure.
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Affiliation(s)
- Samira Fargali
- 1Department of Neuroscience, Box 1065, Ichan School of Medicine at Mt. Sinai, 1 Gustave L. Levy Pl., New York, NY 10029, USA.
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30
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Secretion of SerpinB2 from endothelial cells activated with inflammatory stimuli. Exp Cell Res 2013; 319:1213-9. [DOI: 10.1016/j.yexcr.2013.02.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2013] [Revised: 02/18/2013] [Accepted: 02/21/2013] [Indexed: 11/19/2022]
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31
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Blanco EH, Lagos CF, Andrés ME, Gysling K. An amphipathic alpha-helix in the prodomain of cocaine and amphetamine regulated transcript peptide precursor serves as its sorting signal to the regulated secretory pathway. PLoS One 2013; 8:e59695. [PMID: 23527253 PMCID: PMC3602189 DOI: 10.1371/journal.pone.0059695] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2012] [Accepted: 02/17/2013] [Indexed: 11/18/2022] Open
Abstract
Cocaine and Amphetamine Regulated Transcript (CART) peptides are anorexigenic neuropeptides. The L34F mutation in human CART peptide precursor (proCART) has been linked to obesity (Yanik et al. Endocrinology 147: 39, 2006). Decrease in CART peptide levels in individuals carrying the L34F mutation was attributed to proCART subcellular missorting. We studied proCART features required to enter the regulated secretory pathway. The subcellular localization and the secretion mode of monomeric EGFP fused to the full-length or truncated forms of human proCART transiently transfected in PC12 cells were analyzed. Our results showed that the N-terminal 1-41 fragment of proCART was necessary and sufficient to sort proCART to the regulated secretory pathway. In silico modeling predicted an alpha-helix structure located between residues 24-37 of proCART. Helical wheel projection of proCART alpha-helix showed an amphipathic configuration. The L34F mutation does not modify the amphipathicity of proCART alpha-helix and consistently proCARTL34F was efficiently sorted to the regulated secretory pathway. However, four additional mutations to proCARTL34F that reduced its alpha-helix amphipathicity resulted in the missorting of the mutated proCART toward the constitutive secretory pathway. These findings show that an amphipathic alpha-helix is a key cis-structure for the proCART sorting mechanism. In addition, our results indicate that the association between L34F mutation and obesity is not explained by proCART missorting.
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Affiliation(s)
- Elías H. Blanco
- Millennium Science Nucleus in Stress and Addiction, Department of Cell and Molecular Biology, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
- * E-mail: (EHB); (KG)
| | - Carlos F. Lagos
- Department of Pharmacy, Faculty of Chemistry, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - María Estela Andrés
- Millennium Science Nucleus in Stress and Addiction, Department of Cell and Molecular Biology, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Katia Gysling
- Millennium Science Nucleus in Stress and Addiction, Department of Cell and Molecular Biology, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
- * E-mail: (EHB); (KG)
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Modulating zymogen granule formation in pancreatic AR42J cells. Exp Cell Res 2012; 318:1855-66. [PMID: 22683857 DOI: 10.1016/j.yexcr.2012.05.025] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2011] [Revised: 05/11/2012] [Accepted: 05/24/2012] [Indexed: 01/07/2023]
Abstract
Zymogen granules (ZG) are specialized organelles in the exocrine pancreas which allow digestive enzyme storage and regulated secretion. To investigate ZG biogenesis, cargo sorting and packaging, suitable cellular model systems are required. Here, we demonstrate that granule formation in pancreatic AR42J cells, an acinar model system, can be modulated by altering the growth conditions in cell culture. We find that cultivation of AR42J cells in Panserin™ 401, a serum-free medium, enhances the induction of granule formation in the presence or absence of dexamethasone when compared to standard conditions including serum. Biochemical and morphological studies revealed an increase in ZG markers on the mRNA and protein level, as well as in granule size compared to standard conditions. Our data indicate that this effect is related to pronounced differentiation of AR42J cells. To address if enhanced expression of ZG proteins promotes granule formation, we expressed several zymogens and ZG membrane proteins in unstimulated AR42J cells and in constitutively secreting COS-7 cells. Neither single expression nor co-expression was sufficient to initiate granule formation in AR42J cells or the formation of granule-like structures in COS-7 cells as described for neuroendocrine cargo proteins. The importance of our findings for granule formation in exocrine cells is discussed.
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Dannies PS. Prolactin and growth hormone aggregates in secretory granules: the need to understand the structure of the aggregate. Endocr Rev 2012; 33:254-70. [PMID: 22357343 DOI: 10.1210/er.2011-1002] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Prolactin and GH form reversible aggregates in the trans-Golgi lumen that become the dense cores of secretory granules. Aggregation is an economical means of sorting, because self-association removes the hormones from other possible pathways. Secretory granules containing different aggregates show different behavior, such as the reduction in stimulated release of granules containing R183H-GH compared with release of those containing wild-type hormone. Aggregates may facilitate localization of membrane proteins necessary for transport and exocytosis of secretory granules, and therefore understanding their properties is important. Three types of self-association have been characterized: dimers of human GH that form with Zn(2+), low-affinity self-association of human prolactin caused by acidic pH and Zn(2+) with macromolecular crowding, and amyloid fibers of prolactin. The best candidate for the form in most granules may be low-affinity self-association because it occurs rapidly at Zn(2+) concentrations that are likely to be in granules and reverses rapidly in neutral pH. Amyloid may form in older granules. Determining differences between aggregates of wild type and those of R183H-GH should help to understand why granules containing the mutant behave differently from those containing wild-type hormone. If reversible aggregation of other hormones, including those that are proteolytically processed, is the crucial act in forming granules, rather than use of a sorting signal, then prohormones should form reversible aggregates in solution in conditions that resemble those of the trans-Golgi lumen, including macromolecular crowding.
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Affiliation(s)
- Priscilla S Dannies
- Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut 06520-8066, USA.
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35
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Domínguez N, Estévez-Herrera J, Pardo MR, Pereda D, Machado JD, Borges R. The Functional Role of Chromogranins in Exocytosis. J Mol Neurosci 2012; 48:317-22. [DOI: 10.1007/s12031-012-9736-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2011] [Accepted: 02/24/2012] [Indexed: 10/28/2022]
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36
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Yoo SH, Hur YS. Enrichment of the inositol 1,4,5-trisphosphate receptor/Ca2+ channels in secretory granules and essential roles of chromogranins. Cell Calcium 2012; 51:342-50. [DOI: 10.1016/j.ceca.2011.12.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2011] [Revised: 12/07/2011] [Accepted: 12/10/2011] [Indexed: 11/26/2022]
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37
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Borges R, Domínguez N, Estévez-Herrera J, Pereda D, Machado JD. Vesicular Ca(2+) mediates granule motion and exocytosis. Cell Calcium 2012; 51:338-41. [PMID: 22222091 DOI: 10.1016/j.ceca.2011.12.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2011] [Revised: 12/05/2011] [Accepted: 12/08/2011] [Indexed: 10/14/2022]
Abstract
Secretory vesicles of chromaffin cells are acidic organelles that maintain an increasing pH gradient towards the cytosol (5.5 vs. 7.3) that is mediated by V-ATPase activity. This gradient is primarily responsible for the accumulation of large concentrations of amines and Ca(2+), although the mechanisms mediating Ca(2+) uptake and release from granules, and the physiological relevance of these processes, remain unclear. The presence of a vesicular matrix appears to create a bi-compartmentalised medium in which the major fractions of solutes, including catecholamines, nucleotides and Ca(2+), are strongly associated with vesicle proteins, particularly chromogranins. This association appears to be favoured at acidic pH values. It has been demonstrated that disrupting the pH gradient of secretory vesicles reduces their rate of exocytosis and promotes the leakage of vesicular amines and Ca(2+), dramatically increasing the movement of secretory vesicles and triggering exocytosis. In this short review, we will discuss the data available that highlights the importance of pH in regulating the association between chromogranins, vesicular amines and Ca(2+). We will also address the potential role of vesicular Ca(2+) in two major processes in secretory cells, vesicle movement and exocytosis.
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Affiliation(s)
- Ricardo Borges
- Unidad de Farmacología, Facultad de Medicina, Universidad de La Laguna, Tenerife, Spain.
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38
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Cellular Mechanisms for the Biogenesis and Transport of Synaptic and Dense-Core Vesicles. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2012; 299:27-115. [DOI: 10.1016/b978-0-12-394310-1.00002-3] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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Vázquez-Martínez R, Díaz-Ruiz A, Almabouada F, Rabanal-Ruiz Y, Gracia-Navarro F, Malagón MM. Revisiting the regulated secretory pathway: from frogs to human. Gen Comp Endocrinol 2012; 175:1-9. [PMID: 21907200 DOI: 10.1016/j.ygcen.2011.08.017] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2011] [Revised: 08/16/2011] [Accepted: 08/20/2011] [Indexed: 01/01/2023]
Abstract
The regulated secretory pathway is a hallmark of endocrine and neuroendocrine cells. This process comprises different sequential steps, including ER-associated protein synthesis, ER-to-Golgi protein transport, Golgi-associated posttranslational modification, sorting and packing of secretory proteins into carrier granules, cytoskeleton-based granule transport towards the plasma membrane and tethering, docking and fusion of granules with specialized releasing zones in the plasma membrane. Each one of these steps is tightly regulated by a large number of factors that function in a spatially and temporarily coordinated fashion. During the past three decades, much effort has been devoted to characterize the precise role of the yet-known proteins participating in the different steps of this process and to identify new regulatory factors in order to obtain a unifying picture of the secretory pathway. In spite of this and given the enormous complexity of the process, certain steps are not fully understood yet and many players remain to be identified. In this review, we offer a summary of the current knowledge on the main molecular mechanisms that govern and ensure the correct release of secretory proteins. In addition, we have integrated the advance on the field made possible by studies carried out in non-mammalian vertebrates, which, although not very numerous, have substantially contributed to acquire a mechanistic understanding of the regulated secretory pathway.
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Affiliation(s)
- Rafael Vázquez-Martínez
- Department of Cell Biology, Physiology and Immunology, Instituto Maimónides de Investigación Biomédica, University of Córdoba, 14014-Córdoba, Spain.
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Bartolomucci A, Possenti R, Mahata SK, Fischer-Colbrie R, Loh YP, Salton SRJ. The extended granin family: structure, function, and biomedical implications. Endocr Rev 2011; 32:755-97. [PMID: 21862681 PMCID: PMC3591675 DOI: 10.1210/er.2010-0027] [Citation(s) in RCA: 228] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The chromogranins (chromogranin A and chromogranin B), secretogranins (secretogranin II and secretogranin III), and additional related proteins (7B2, NESP55, proSAAS, and VGF) that together comprise the granin family subserve essential roles in the regulated secretory pathway that is responsible for controlled delivery of peptides, hormones, neurotransmitters, and growth factors. Here we review the structure and function of granins and granin-derived peptides and expansive new genetic evidence, including recent single-nucleotide polymorphism mapping, genomic sequence comparisons, and analysis of transgenic and knockout mice, which together support an important and evolutionarily conserved role for these proteins in large dense-core vesicle biogenesis and regulated secretion. Recent data further indicate that their processed peptides function prominently in metabolic and glucose homeostasis, emotional behavior, pain pathways, and blood pressure modulation, suggesting future utility of granins and granin-derived peptides as novel disease biomarkers.
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Affiliation(s)
- Alessandro Bartolomucci
- Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, Minnesota 55455, USA
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Koshimizu H, Cawley NX, Kim T, Yergey AL, Loh YP. Serpinin: a novel chromogranin A-derived, secreted peptide up-regulates protease nexin-1 expression and granule biogenesis in endocrine cells. Mol Endocrinol 2011; 25:732-44. [PMID: 21436258 DOI: 10.1210/me.2010-0124] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Previously we demonstrated that chromogranin A (CgA) promoted secretory granule biogenesis in endocrine cells by stabilizing and preventing granule protein degradation in the Golgi, through up-regulation of expression of the protease inhibitor, protease nexin-1 (PN-1). However, the mechanism by which CgA signals the increase of PN-1 expression is unknown. Here we identified a 2.9-kDa CgA-C-terminus peptide, which we named serpinin, in conditioned media from AtT-20 cells, a corticotroph cell line, which up-regulated PN-1 mRNA expression. Serpinin was secreted from AtT-20 cells upon high potassium stimulation and increased PN-1 mRNA transcription in these cells, in an actinomycin D-inhibitable manner. CgA itself and other CgA-derived peptides, when added to AtT-20 cell media, had no effect on PN-1 expression. Treatment of AtT-20 cells with 10 nm serpinin elevated cAMP levels and PN-1 mRNA expression, and this effect was inhibited by a protein kinase A inhibitor, 6-22 amide. Serpinin and a cAMP analog, 8-bromo-cAMP, promoted the translocation of the transcription factor Sp1 into the nucleus, which is known to drive PN-1 expression. Additionally, an Sp1 inhibitor, mithramycin A inhibited the serpinin-induced PN-1 mRNA up-regulation. Furthermore, a luciferase reporter assay demonstrated serpinin-induced up-regulation of PN-1 promoter activity in an Sp1-dependent manner. When added to CgB-transfected 6T3 cells, a mutant AtT20 cell line, serpinin induced granule biogenesis as evidenced by the presence of CgB puncta accumulation in the processes and tips. Our findings taken together show that serpinin, a novel CgA-derived peptide, is secreted upon stimulation of corticotrophs and plays an important autocrine role in up-regulating PN-1-dependent granule biogenesis via a cAMP-protein kinase A-Sp1 pathway to replenish released granules.
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Affiliation(s)
- Hisatsugu Koshimizu
- Section on Cellular Neurobiology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA
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Zhang K, Chen Y, Wen G, Mahata M, Rao F, Fung MM, Vaingankar S, Biswas N, Gayen JR, Friese RS, Mahata SK, Hamilton BA, O’Connor DT. Catecholamine storage vesicles: role of core protein genetic polymorphisms in hypertension. Curr Hypertens Rep 2011; 13:36-45. [PMID: 21104344 PMCID: PMC3016145 DOI: 10.1007/s11906-010-0170-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Hypertension is a complex trait with deranged autonomic control of the circulation. The sympathoadrenal system exerts minute-to-minute control over cardiac output and vascular tone. Catecholamine storage vesicles (or chromaffin granules) of the adrenal medulla contain remarkably high concentrations of chromogranins/secretogranins (or "granins"), catecholamines, neuropeptide Y, adenosine triphosphate (ATP), and Ca(2+). Within secretory granules, granins are co-stored with catecholamine neurotransmitters and co-released upon stimulation of the regulated secretory pathway. The principal granin family members, chromogranin A (CHGA), chromogranin B (CHGB), and secretogranin II (SCG2), may have evolved from shared ancestral exons by gene duplication. This article reviews human genetic variation at loci encoding the major granins and probes the effects of such polymorphisms on blood pressure, using twin pairs to probe heritability and individuals with the most extreme blood pressure values in the population to study hypertension.
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Affiliation(s)
- Kuixing Zhang
- Department of Medicine and Institute for Genomic Medicine (IGM), University of California at San Diego School of Medicine, 9500 Gilman Drive, La Jolla, CA 92093-0838 USA
| | - Yuqing Chen
- Department of Medicine and Institute for Genomic Medicine (IGM), University of California at San Diego School of Medicine, 9500 Gilman Drive, La Jolla, CA 92093-0838 USA
| | - Gen Wen
- Department of Medicine and Institute for Genomic Medicine (IGM), University of California at San Diego School of Medicine, 9500 Gilman Drive, La Jolla, CA 92093-0838 USA
| | - Manjula Mahata
- Department of Medicine and Institute for Genomic Medicine (IGM), University of California at San Diego School of Medicine, 9500 Gilman Drive, La Jolla, CA 92093-0838 USA
| | - Fangwen Rao
- Department of Medicine and Institute for Genomic Medicine (IGM), University of California at San Diego School of Medicine, 9500 Gilman Drive, La Jolla, CA 92093-0838 USA
| | - Maple M. Fung
- Department of Medicine and Institute for Genomic Medicine (IGM), University of California at San Diego School of Medicine, 9500 Gilman Drive, La Jolla, CA 92093-0838 USA
- VA San Diego Healthcare System, San Diego, CA USA
| | - Sucheta Vaingankar
- Department of Medicine and Institute for Genomic Medicine (IGM), University of California at San Diego School of Medicine, 9500 Gilman Drive, La Jolla, CA 92093-0838 USA
| | - Nilima Biswas
- Department of Medicine and Institute for Genomic Medicine (IGM), University of California at San Diego School of Medicine, 9500 Gilman Drive, La Jolla, CA 92093-0838 USA
| | - Jiaur R. Gayen
- Department of Medicine and Institute for Genomic Medicine (IGM), University of California at San Diego School of Medicine, 9500 Gilman Drive, La Jolla, CA 92093-0838 USA
| | - Ryan S. Friese
- Department of Medicine and Institute for Genomic Medicine (IGM), University of California at San Diego School of Medicine, 9500 Gilman Drive, La Jolla, CA 92093-0838 USA
| | - Sushil K. Mahata
- Department of Medicine and Institute for Genomic Medicine (IGM), University of California at San Diego School of Medicine, 9500 Gilman Drive, La Jolla, CA 92093-0838 USA
- VA San Diego Healthcare System, San Diego, CA USA
| | - Bruce A. Hamilton
- Department of Medicine and Institute for Genomic Medicine (IGM), University of California at San Diego School of Medicine, 9500 Gilman Drive, La Jolla, CA 92093-0838 USA
| | - Daniel T. O’Connor
- Department of Medicine and Institute for Genomic Medicine (IGM), University of California at San Diego School of Medicine, 9500 Gilman Drive, La Jolla, CA 92093-0838 USA
- Department of Pharmacology, University of California at San Diego, San Diego, CA USA
- VA San Diego Healthcare System, San Diego, CA USA
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Yoo SH. Role of secretory granules in inositol 1,4,5-trisphosphate-dependent Ca(2+) signaling: from phytoplankton to mammals. Cell Calcium 2010; 50:175-83. [PMID: 21176957 DOI: 10.1016/j.ceca.2010.11.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2010] [Revised: 11/30/2010] [Accepted: 11/30/2010] [Indexed: 01/20/2023]
Abstract
The majority of secretory cell calcium is stored in secretory granules that serve as the major IP(3)-dependent intracellular Ca(2+) store. Even in unicellular phytoplankton secretory granules are responsible for the IP(3)-induced Ca(2+) release that triggers exocytosis. The number of secretory granules in the cell is directly related not only to the magnitude of IP(3)-induced Ca(2+) release, which accounts for the majority of the IP(3)-induced cytoplasmic Ca(2+) release in neuroendocrine cells, but also to the IP(3) sensitivity of the cytoplasmic IP(3) receptor (IP(3)R)/Ca(2+) channels. Moreover, secretory granules contain the highest IP(3)R concentrations and the largest amounts of IP(3)Rs in any subcellular organelles in neuroendocrine cells. Secretory granules from phytoplankton to mammals contain large amounts of polyanionic molecules, chromogranins being the major molecules in mammals, in addition to acidic intragranular pH and high Ca(2+) concentrations. The polyanionic molecules undergo pH- and Ca(2+)-dependent conformational changes that serve as a molecular basis for condensation-decondensation phase transitions of the intragranular matrix. Likewise, chromogranins undergo pH- and Ca(2+)-dependent conformational changes with increased exposure of the structure and increased interactions with Ca(2+) and other granule components at acidic pH. The unique physico-chemical properties of polyanionic molecules appear to be at the center of biogenesis, and physiological functions of secretory granules in living organisms from primitive to advanced species.
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Affiliation(s)
- Seung Hyun Yoo
- Department of Biochemistry, Inha University School of Medicine, Jung Gu, Incheon 400-712, Republic of Korea.
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Elias S, Delestre C, Courel M, Anouar Y, Montero-Hadjadje M. Chromogranin A as a crucial factor in the sorting of peptide hormones to secretory granules. Cell Mol Neurobiol 2010; 30:1189-95. [PMID: 21046450 DOI: 10.1007/s10571-010-9595-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2010] [Accepted: 09/02/2010] [Indexed: 12/14/2022]
Abstract
Chromogranin A (CgA) is a soluble glycoprotein stored along with hormones and neuropeptides in secretory granules of endocrine cells. In the last four decades, intense efforts have been concentrated to characterize the structure and the biological function of CgA. Besides, CgA has been widely used as a diagnostic marker for tumors of endocrine origin, essential hypertension, various inflammatory diseases, and neurodegenerative disorders such as amyotrophic lateral sclerosis and Alzheimer's disease. CgA displays peculiar structural features, including numerous multibasic cleavage sites for prohormone convertases as well as a high proportion of acidic residues. Thus, it has been proposed that CgA represents a precursor of biologically active peptides, and a "granulogenic protein" that plays an important role as a chaperone for catecholamine storage in adrenal chromaffin cells. The widespread distribution of CgA throughout the neuroendocrine system prompted several groups to investigate the role of CgA in peptide hormone sorting to the regulated secretory pathway. This review summarizes the findings and theoretical concepts around the molecular machinery used by CgA to exert this putative intracellular function. Since CgA terminal regions exhibited strong sequence conservation through evolution, our work focused on the implication of these domains as potential functional determinants of CgA. Characterization of the molecular signals implicating CgA in the intracellular traffic of hormones represents a major biological issue that may contribute to unraveling the mechanisms defining the secretory competence of neuroendocrine cells.
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Affiliation(s)
- Salah Elias
- Laboratory of Neuronal and Neuroendocrine Differentiation and Communication, INSERM U982, University of Rouen, Mont-St-Aignan Cedex, France
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Yoo SH, Huh YH, Hur YS. Inositol 1,4,5-trisphosphate receptor in chromaffin secretory granules and its relation to chromogranins. Cell Mol Neurobiol 2010; 30:1155-61. [PMID: 21046461 DOI: 10.1007/s10571-010-9564-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2010] [Accepted: 09/02/2010] [Indexed: 09/29/2022]
Abstract
The inositol 1,4,5-trisphosphate (IP(3))-mediated intracellular Ca(2+) releases in secretory cells play vital roles in controlling not only the intracellular Ca(2+) concentrations but also the Ca(2+)-dependent exocytotic processes. Of intracellular organelles that release Ca(2+) in response to IP(3), secretory granules stand out as the most prominent organelle and are responsible for the majority of IP(3)-dependent Ca(2+) releases in the cytoplasm of chromaffin cells. Bovine chromaffin granules were the first granules that demonstrated the IP(3)-mediated Ca(2+) release as well as the presence of the IP(3) receptor (IP(3)R) in granule membranes. Secretory granules contain all three (type 1, 2, and 3) IP(3)R isoforms, and 58-69% of total cellular IP(3)R isoforms are expressed in bovine chromaffin granules. Moreover, secretory granules contain large amounts (2-4 mM) of chromogranins and secretogranins; chromogranins A and B, and secretogranin II being the major species. Chromogranins A and B, and secretogranin II are high-capacity, low-affinity Ca(2+) binding proteins, binding 30-93 mol of Ca(2+)/mol of protein with dissociation constants of 1.5-4.0 mM. Due to this high Ca(2+) storage properties of chromogranins secretory granules contain ~40 mM Ca(2+). Furthermore, chromogranins A and B directly interact with the IP(3)Rs and modulate the IP(3)R/Ca(2+) channels, i.e., increasing the open probability and the mean open time of the channels 8- to 16-fold and 9- to 42-fold, respectively. Coupled chromogranins change the IP(3)R/Ca(2+) channels to a more ordered, release-ready state, whereby making the IP(3)R/Ca(2+) channels significantly more sensitive to IP(3).
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Affiliation(s)
- Seung Hyun Yoo
- Department of Biochemistry, Inha University School of Medicine, Jung Gu, Incheon 400-712, Korea.
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Koshimizu H, Kim T, Cawley NX, Loh YP. Reprint of: Chromogranin A: a new proposal for trafficking, processing and induction of granule biogenesis. ACTA ACUST UNITED AC 2010; 165:95-101. [PMID: 20920534 DOI: 10.1016/j.regpep.2010.09.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Chromogranin A (CgA), a member of the granin family serves several important cell biological roles in (neuro)endocrine cells which are summarized in this review. CgA is a "prohormone" that is synthesized at the rough endoplasmic reticulum and transported into the cisternae of this organelle via its signal peptide. It is then trafficked to the Golgi complex and then to the trans-Golgi network (TGN) where CgA aggregates at low pH in the presence of calcium. The CgA aggregates provide the physical driving force to induce budding of the TGN membrane resulting in dense core granule (DCG) formation. Within the granule, a small amount of the CgA is processed to bioactive peptides, including a predicted C-terminal peptide, serpinin. Upon stimulation, DCGs undergo exocytosis and CgA and its derived peptides are released. Serpinin, acting extracellularly is able to signal the increase in transcription of a serine protease inhibitor, protease nexin-1 (PN-1) that protects DCG proteins against degradation in the Golgi complex, which then enhances DCG biogenesis to replenish those that were released. Thus CgA and its derived peptide, serpinin, plays a significant role in granule formation and regulation of granule biogenesis, respectively, in (neuro) endocrine cells.
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Affiliation(s)
- Hisatsugu Koshimizu
- Section on Cellular Neurobiology, Program on Developmental Neuroscience, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health Bethesda, MD 20892, USA
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Courel M, Soler-Jover A, Rodriguez-Flores JL, Mahata SK, Elias S, Montero-Hadjadje M, Anouar Y, Giuly RJ, O'Connor DT, Taupenot L. Pro-hormone secretogranin II regulates dense core secretory granule biogenesis in catecholaminergic cells. J Biol Chem 2010; 285:10030-10043. [PMID: 20061385 PMCID: PMC2843166 DOI: 10.1074/jbc.m109.064196] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2009] [Revised: 12/16/2009] [Indexed: 11/06/2022] Open
Abstract
Processes underlying the formation of dense core secretory granules (DCGs) of neuroendocrine cells are poorly understood. Here, we present evidence that DCG biogenesis is dependent on the secretory protein secretogranin (Sg) II, a member of the granin family of pro-hormone cargo of DCGs in neuroendocrine cells. Depletion of SgII expression in PC12 cells leads to a decrease in both the number and size of DCGs and impairs DCG trafficking of other regulated hormones. Expression of SgII fusion proteins in a secretory-deficient PC12 variant rescues a regulated secretory pathway. SgII-containing dense core vesicles share morphological and physical properties with bona fide DCGs, are competent for regulated exocytosis, and maintain an acidic luminal pH through the V-type H(+)-translocating ATPase. The granulogenic activity of SgII requires a pH gradient along this secretory pathway. We conclude that SgII is a critical factor for the regulation of DCG biogenesis in neuroendocrine cells, mediating the formation of functional DCGs via its pH-dependent aggregation at the trans-Golgi network.
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Affiliation(s)
- Maïté Courel
- Department of Medicine, University of California San Diego, La Jolla, California 92093-0838.
| | - Alex Soler-Jover
- Department of Medicine, University of California San Diego, La Jolla, California 92093-0838
| | | | - Sushil K Mahata
- Department of Medicine, University of California San Diego, La Jolla, California 92093-0838; Veteran Affairs San Diego Healthcare System, San Diego, California 92093
| | - Salah Elias
- INSERM U982, University of Rouen, 76821 Mont-St.-Aignan Cedex, France
| | | | - Youssef Anouar
- INSERM U982, University of Rouen, 76821 Mont-St.-Aignan Cedex, France
| | - Richard J Giuly
- National Center for Microscopy and Imaging Research, University of California San Diego, La Jolla, California 92093
| | - Daniel T O'Connor
- Department of Medicine, University of California San Diego, La Jolla, California 92093-0838; Veteran Affairs San Diego Healthcare System, San Diego, California 92093.
| | - Laurent Taupenot
- Department of Medicine, University of California San Diego, La Jolla, California 92093-0838; Veteran Affairs San Diego Healthcare System, San Diego, California 92093.
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Obermüller S, Calegari F, King A, Lindqvist A, Lundquist I, Salehi A, Francolini M, Rosa P, Rorsman P, Huttner WB, Barg S. Defective secretion of islet hormones in chromogranin-B deficient mice. PLoS One 2010; 5:e8936. [PMID: 20126668 PMCID: PMC2812483 DOI: 10.1371/journal.pone.0008936] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2009] [Accepted: 01/11/2010] [Indexed: 12/21/2022] Open
Abstract
Granins are major constituents of dense-core secretory granules in neuroendocrine cells, but their function is still a matter of debate. Work in cell lines has suggested that the most abundant and ubiquitously expressed granins, chromogranin A and B (CgA and CgB), are involved in granulogenesis and protein sorting. Here we report the generation and characterization of mice lacking chromogranin B (CgB-ko), which were viable and fertile. Unlike neuroendocrine tissues, pancreatic islets of these animals lacked compensatory changes in other granins and were therefore analyzed in detail. Stimulated secretion of insulin, glucagon and somatostatin was reduced in CgB-ko islets, in parallel with somewhat impaired glucose clearance and reduced insulin release, but normal insulin sensitivity in vivo. CgB-ko islets lacked specifically the rapid initial phase of stimulated secretion, had elevated basal insulin release, and stored and released twice as much proinsulin as wildtype (wt) islets. Stimulated release of glucagon and somatostatin was reduced as well. Surprisingly, biogenesis, morphology and function of insulin granules were normal, and no differences were found with regard to beta-cell stimulus-secretion coupling. We conclude that CgB is not required for normal insulin granule biogenesis or maintenance in vivo, but is essential for adequate secretion of islet hormones. Consequentially CgB-ko animals display some, but not all, hallmarks of human type-2 diabetes. However, the molecular mechanisms underlying this defect remain to be determined.
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Affiliation(s)
| | - Federico Calegari
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
- CNR Institute of Neuroscience, Department of Medical Pharmacology, University of Milan, Milan, Italy
| | - Angus King
- Department of Neurobiology, University of Heidelberg, Heidelberg, Germany
| | - Anders Lindqvist
- Department of Clinical Sciences-Malmö, Lund University, Malmö, Sweden
| | - Ingmar Lundquist
- Department of Clinical Sciences-Malmö, Lund University, Malmö, Sweden
| | - Albert Salehi
- Department of Clinical Sciences-Malmö, Lund University, Malmö, Sweden
| | - Maura Francolini
- CNR Institute of Neuroscience, Department of Medical Pharmacology, University of Milan, Milan, Italy
| | - Patrizia Rosa
- CNR Institute of Neuroscience, Department of Medical Pharmacology, University of Milan, Milan, Italy
| | - Patrik Rorsman
- Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), University of Oxford, Churchill Hospital, Oxford, United Kingdom
| | - Wieland B. Huttner
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
- Department of Neurobiology, University of Heidelberg, Heidelberg, Germany
- * E-mail: (WBH); (SB)
| | - Sebastian Barg
- Department of Clinical Sciences-Malmö, Lund University, Malmö, Sweden
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
- * E-mail: (WBH); (SB)
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Pearl CA, Jablonka-Shariff A, Boime I. Rerouting of a follicle-stimulating hormone analog to the regulated secretory pathway. Endocrinology 2010; 151:388-93. [PMID: 19887562 PMCID: PMC2803143 DOI: 10.1210/en.2009-0939] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
LH and FSH are produced by the same gonadotrope cells of the anterior pituitary but differ in their mode of secretion. This coordinated secretion of LH and FSH is essential for normal follicular development and ovulation in females and for spermatogenesis in males. The structural signals encoded in the LH and FSH subunits that govern the intracellular sorting of LH through the regulated secretory pathway and FSH through the constitutive pathway are largely unknown. Our laboratory recently identified the seven amino acid carboxy tail of LH beta as a sorting signal for LH in GH(3) cells. Here we compared the morphological features of GH(3) cells expressing an FSH analog containing the heptapeptide (FL7AA) with wild-type FSH using confocal microscopy. These experiments were performed to develop a rerouting model for examining structure-function links between secretion pathways of FSH/LH and their biological action. Both FSH- and LH-expressing cells exhibit a fluorescence pattern of randomly dispersed cytoplasmic puncta. FL7AA expressing cells have more intracellular accumulation compared with wild-type FSH and display a unique halo pattern of fluorescence near the plasma membrane. Such a pattern was not observed in cells expressing FSH or LH. Our results demonstrate that this FSH analog containing the carboxy heptapeptide of LH beta is rerouted to the regulated secretory pathway in GH(3) cells. This rerouted gonadotropin provides a unique model to study the trafficking, regulation, and function of LH and FSH.
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Affiliation(s)
- Christopher A Pearl
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, Missouri 63110, USA
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50
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Hamanaka Y, Park D, Yin P, Annangudi SP, Edwards TN, Sweedler J, Meinertzhagen IA, Taghert PH. Transcriptional orchestration of the regulated secretory pathway in neurons by the bHLH protein DIMM. Curr Biol 2009; 20:9-18. [PMID: 20045330 DOI: 10.1016/j.cub.2009.11.065] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2009] [Revised: 11/19/2009] [Accepted: 11/24/2009] [Indexed: 10/20/2022]
Abstract
BACKGROUND The Drosophila basic helix-loop-helix (bHLH) gene dimmed (dimm) promotes a neurosecretory/neuroendocrine phenotype in cells but is not associated with specific neuropeptides or neurohormones. Rather, it is expressed by those peptidergic neurons that project long axons and appear to produce large amounts of secretory peptides. Here, we genetically transform nonpeptidergic neurons in Drosophila to study DIMM's action mechanisms. RESULTS Nonpeptidergic neurons normally fail to accumulate ectopic neuropeptides. We now show that they will do so when they are also forced to express ectopic DIMM. Furthermore, mass spectrometry shows that photoreceptors, which are normally nonpeptidergic, fail to process an ectopic neuropeptide precursor to make bioactive peptides but will do so efficiently when DIMM is co-misexpressed. Likewise, photoreceptors, which normally package the fast neurotransmitter histamine within small clear synaptic vesicles, produce numerous large dense-core vesicles (LDCVs) when they misexpress DIMM. These novel LDCVs accumulate ectopic neuropeptide when photoreceptors co-misexpress a neuropeptide transgene. DIMM-expressing photoreceptors no longer accumulate histamine and lose synaptic organelles critical to their normal physiology. CONCLUSIONS These findings indicate that DIMM suppresses conventional fast neurotransmission and promotes peptidergic neurosecretory properties. We conclude that DIMM normally provides a comprehensive transcriptional control to direct the differentiation of dedicated neuroendocrine neurons.
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Affiliation(s)
- Yoshitaka Hamanaka
- Department of Psychology, Life Sciences Centre, Dalhousie University, Halifax, NS B3H 4J1, Canada
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