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Shang ZZ, Ye HY, Gao X, Wang HY, Li QM, Hu JM, Zhang FY, Luo JP. An acidic polysaccharide promoting GLP-1 secretion from Dendrobium huoshanense protocorm-like bodies: Structure validation and activity exploration. Int J Biol Macromol 2024; 278:134783. [PMID: 39153673 DOI: 10.1016/j.ijbiomac.2024.134783] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2024] [Revised: 06/20/2024] [Accepted: 08/14/2024] [Indexed: 08/19/2024]
Abstract
Glucagon-like peptide-1 (GLP-1) as a multifunctional hormone is secreted mainly from enteroendocrine L-cells, and enhancing its endogenous secretion has potential benefits of regulating glucose homeostasis and controlling body weight gain. In the present study, a novel polysaccharide (h-DHP) with high ability to enhance plasma GLP-1 level in mice was isolated from Dendrobium huoshanense protocorm-like bodies under the guidance of activity evaluation. Structural identification showed that h-DHP was an acidic polysaccharide with the molecular weight of 1.38 × 105 Da, and was composed of galactose, glucose, arabinose and glucuronic acid at a molar ratio of 15.7: 11.2: 4.5: 1.0 with a backbone consisting of →5)-α-L-Araf-(1→, →3)-α-D-Galp-(1→, →6)-α-D-Galp-(1→, →3,6)-α-D-Galp-(1→, →6)-β-D-Glcp-(1→ and →4,6)-β-D-Glcp-(1→ along with branches consisting of α-L-Araf-(1→, α-D-Galp-(1→, α-D-GlcAp-(1→, β-D-Glcp-(1→ and →4)-β-D-Glcp-(1→. Animal experiments with different administration routes demonstrated that h-DHP-enhanced plasma GLP-1 level was attributed to h-DHP-promoted GLP-1 secretion in the enteroendocrine L-cells, which was supported by h-DHP-enhanced extracellular GLP-1 level in STC-1 cells. Inhibition of adenylate cyclase and phospholipase C indicated that cAMP and cAMP-triggered intracellular Ca2+ increase participated in h-DHP-promoted GLP-1 secretion. These results suggested that h-DHP has the potential of enhancing endogenous GLP-1 level through h-DHP-promoted and cAMP-mediated GLP-1 secretion from enteroendocrine cells.
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Affiliation(s)
- Zhen-Zi Shang
- School of Food and Biological Engineering, Hefei University of Technology, Hefei 230601, People's Republic of China
| | - Hui-Yu Ye
- School of Food and Biological Engineering, Hefei University of Technology, Hefei 230601, People's Republic of China
| | - Xin Gao
- School of Food and Biological Engineering, Hefei University of Technology, Hefei 230601, People's Republic of China
| | - Hong-Yan Wang
- State Key Laboratory of Tea Plant Biology and Utilization, School of Tea and Food Science and Technology, Anhui Agricultural University, Hefei, Anhui 230036, People's Republic of China
| | - Qiang-Ming Li
- School of Food and Biological Engineering, Hefei University of Technology, Hefei 230601, People's Republic of China.
| | - Jiang-Miao Hu
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, Yunnan, People's Republic of China
| | - Feng-Yun Zhang
- School of Basic Medical Sciences, Anhui Medical University, Hefei 230032, People's Republic of China
| | - Jian-Ping Luo
- School of Food and Biological Engineering, Hefei University of Technology, Hefei 230601, People's Republic of China.
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2
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Mastos C, Xu X, Keen AC, Halls ML. Signalling of Adrenoceptors: Canonical Pathways and New Paradigms. Handb Exp Pharmacol 2024. [PMID: 38227198 DOI: 10.1007/164_2023_704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2024]
Abstract
The concept of G protein-coupled receptors initially arose from studies of the β-adrenoceptor, adenylyl cyclase, and cAMP signalling pathway. Since then both canonical G protein-coupled receptor signalling pathways and emerging paradigms in receptor signalling have been defined by experiments focused on adrenoceptors. Here, we discuss the evidence for G protein coupling specificity of the nine adrenoceptor subtypes. We summarise the ability of each of the adrenoceptors to activate proximal signalling mediators including cAMP, calcium, mitogen-activated protein kinases, and protein kinase C pathways. Finally, we highlight the importance of precise spatial and temporal control of adrenoceptor signalling that is controlled by the localisation of receptors at intracellular membranes and in larger protein complexes.
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Affiliation(s)
- Chantel Mastos
- Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
| | - Xiaomeng Xu
- Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
| | - Alastair C Keen
- Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
| | - Michelle L Halls
- Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia.
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3
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Schmidt G, Rienas G, Müller S, Edinger F, Sander M, Koch C, Henrich M. A 20:1 synergetic mixture of cafedrine/theodrenaline accelerates particle transport velocity in murine tracheal epithelium via IP 3 receptor-associated calcium release. Front Pharmacol 2023; 14:1155930. [PMID: 37654612 PMCID: PMC10466409 DOI: 10.3389/fphar.2023.1155930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Accepted: 07/26/2023] [Indexed: 09/02/2023] Open
Abstract
Background: Mucociliary clearance is a pivotal physiological mechanism that protects the lung by ridding the lower airways of pollution and colonization by pathogens, thereby preventing infections. The fixed 20:1 combination of cafedrine and theodrenaline has been used to treat perioperative hypotension or hypotensive states due to emergency situations since the 1960s. Because mucociliary clearance is impaired during mechanical ventilation and critical illness, the present study aimed to evaluate the influence of cafedrine/theodrenaline on mucociliary clearance. Material and Methods: The particle transport velocity (PTV) of murine trachea preparations was measured as a surrogate for mucociliary clearance under the influence of cafedrine/theodrenaline, cafedrine alone, and theodrenaline alone. Inhibitory substances were applied to elucidate relevant signal transduction cascades. Results: All three applications of the combination of cafedrine/theodrenaline, cafedrine alone, or theodrenaline alone induced a sharp increase in PTV in a concentration-dependent manner with median effective concentrations of 0.46 µM (consisting of 9.6 µM cafedrine and 0.46 µM theodrenaline), 408 and 4 μM, respectively. The signal transduction cascades were similar for the effects of both cafedrine and theodrenaline at the murine respiratory epithelium. While PTV remained at its baseline value after non-selective inhibition of β-adrenergic receptors and selective inhibition of β1 receptors, cafedrine/theodrenaline, cafedrine alone, or theodrenaline alone increased PTV despite the inhibition of the protein kinase A. However, IP3 receptor activation was found to be the pivotal mechanism leading to the increase in murine PTV, which was abolished when IP3 receptors were inhibited. Depleting intracellular calcium stores with caffeine confirmed calcium as another crucial messenger altering the PTV after the application of cafedrine/theodrenaline. Discussion: Cafedrine/theodrenaline, cafedrine alone, and theodrenaline alone exert their effects via IP3 receptor-associated calcium release that is ultimately triggered by β1-adrenergic receptor stimulation. Synergistic effects at the β1-adrenergic receptor are highly relevant to alter the PTV of the respiratory epithelium at clinically relevant concentrations. Further investigations are needed to assess the value of cafedrine/theodrenaline-mediated alterations in mucociliary function in clinical practice.
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Affiliation(s)
- Götz Schmidt
- Department of Anesthesiology, Operative Intensive Care Medicine and Pain Therapy, Justus Liebig University Giessen, Giessen, Germany
| | - Gerrit Rienas
- Department of Anesthesiology, Operative Intensive Care Medicine and Pain Therapy, Justus Liebig University Giessen, Giessen, Germany
| | - Sabrina Müller
- Department of Anesthesiology, Operative Intensive Care Medicine and Pain Therapy, Justus Liebig University Giessen, Giessen, Germany
| | - Fabian Edinger
- Department of Anesthesiology, Operative Intensive Care Medicine and Pain Therapy, Justus Liebig University Giessen, Giessen, Germany
| | - Michael Sander
- Department of Anesthesiology, Operative Intensive Care Medicine and Pain Therapy, Justus Liebig University Giessen, Giessen, Germany
| | - Christian Koch
- Department of Anesthesiology, Operative Intensive Care Medicine and Pain Therapy, Justus Liebig University Giessen, Giessen, Germany
| | - Michael Henrich
- Department of Anesthesiology, Intensive Care Medicine, Emergency Medicine, Vidia St. Vincentius-Clinic Karlsruhe gAG, Karlsruhe, Germany
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4
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Pandey S, Mangmool S, Madreiter-Sokolowski CT, Wichaiyo S, Luangmonkong T, Parichatikanond W. Exendin-4 protects against high glucose-induced mitochondrial dysfunction and oxidative stress in SH-SY5Y neuroblastoma cells through GLP-1 receptor/Epac/Akt signaling. Eur J Pharmacol 2023:175896. [PMID: 37391007 DOI: 10.1016/j.ejphar.2023.175896] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 06/16/2023] [Accepted: 06/28/2023] [Indexed: 07/02/2023]
Abstract
Mitochondrial dysfunction under diabetic condition leads to the development and progression of neurodegenerative complications. Recently, the beneficial effects of glucagon-like peptide-1 (GLP-1) receptor agonists on diabetic neuropathies have been widely recognized. However, molecular mechanisms underlying the neuroprotective effects of GLP-1 receptor agonists against high glucose (HG)-induced neuronal damages is not completely elucidated. Here, we investigated the underlying mechanisms of GLP-1 receptor agonist treatment against oxidative stress, mitochondrial dysfunction, and neuronal damages under HG-conditions mimicking a diabetic hyperglycemic state in SH-SY5Y neuroblastoma cells. We revealed that treatment with exendin-4, a GLP-1 receptor agonist, not only increased the expression of survival markers, phospho-Akt/Akt and Bcl-2, but also decreased the expression of pro-apoptotic marker, Bax, and reduced the levels of reactive oxygen species (ROS) defense markers (catalase, SOD-2, and HO-1) under HG conditions. The expressions of mitochondrial function associated genes, MCU and UCP3, and mitochondrial fission genes, DRP1 and FIS1, were decreased by exendin-4 compared to non-treated levels, while the protein expression levels of mitochondrial homeostasis regulators, Parkin and PINK1, were enhanced. In addition, blockade of Epac and Akt activities was able to antagonize these neuroprotective effects of exendin-4. Collectively, we demonstrated that stimulation of GLP-1 receptor propagates a neuroprotective cascade against the oxidative stresses and mitochondrial dysfunctions as well as augments survival through the Epac/Akt-dependent pathway. Therefore, the revealed mechanisms underlying GLP-1 receptor pathway by preserving mitochondrial homeostasis would be a therapeutic candidate to alleviate neuronal dysfunctions and delay the progression of diabetic neuropathies.
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Affiliation(s)
- Sudhir Pandey
- Department of Pharmacology, Faculty of Pharmacy, Mahidol University, Bangkok, 10400, Thailand
| | - Supachoke Mangmool
- Department of Pharmacology, Faculty of Science, Mahidol University, Bangkok, 10400, Thailand
| | - Corina T Madreiter-Sokolowski
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Graz, 8010, Austria
| | - Surasak Wichaiyo
- Department of Pharmacology, Faculty of Pharmacy, Mahidol University, Bangkok, 10400, Thailand
| | - Theerut Luangmonkong
- Department of Pharmacology, Faculty of Pharmacy, Mahidol University, Bangkok, 10400, Thailand
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5
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Wang XT, Zhou L, Dong BB, Xu FX, Wang DJ, Shen EW, Cai XY, Wang Y, Wang N, Ji SJ, Chen W, Schonewille M, Zhu JJ, De Zeeuw CI, Shen Y. cAMP-EPAC-PKCε-RIM1α signaling regulates presynaptic long-term potentiation and motor learning. eLife 2023; 12:e80875. [PMID: 37159499 PMCID: PMC10171863 DOI: 10.7554/elife.80875] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 04/25/2023] [Indexed: 05/11/2023] Open
Abstract
The cerebellum is involved in learning of fine motor skills, yet whether presynaptic plasticity contributes to such learning remains elusive. Here, we report that the EPAC-PKCε module has a critical role in a presynaptic form of long-term potentiation in the cerebellum and motor behavior in mice. Presynaptic cAMP-EPAC-PKCε signaling cascade induces a previously unidentified threonine phosphorylation of RIM1α, and thereby initiates the assembly of the Rab3A-RIM1α-Munc13-1 tripartite complex that facilitates docking and release of synaptic vesicles. Granule cell-specific blocking of EPAC-PKCε signaling abolishes presynaptic long-term potentiation at the parallel fiber to Purkinje cell synapses and impairs basic performance and learning of cerebellar motor behavior. These results unveil a functional relevance of presynaptic plasticity that is regulated through a novel signaling cascade, thereby enriching the spectrum of cerebellar learning mechanisms.
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Affiliation(s)
- Xin-Tai Wang
- Department of Physiology and Department of Psychiatry, Sir Run Run Shaw Hospital, Zhejiang University School of MedicineHangzhouChina
- Institute of Life Sciences, College of Life and Environmental Sciences, Hangzhou Normal UniversityHangzhouChina
| | - Lin Zhou
- Department of Physiology and Department of Psychiatry, Sir Run Run Shaw Hospital, Zhejiang University School of MedicineHangzhouChina
| | - Bin-Bin Dong
- Department of Physiology and Department of Psychiatry, Sir Run Run Shaw Hospital, Zhejiang University School of MedicineHangzhouChina
| | - Fang-Xiao Xu
- Department of Physiology and Department of Psychiatry, Sir Run Run Shaw Hospital, Zhejiang University School of MedicineHangzhouChina
| | - De-Juan Wang
- Department of Physiology and Department of Psychiatry, Sir Run Run Shaw Hospital, Zhejiang University School of MedicineHangzhouChina
| | - En-Wei Shen
- Department of Physiology and Department of Psychiatry, Sir Run Run Shaw Hospital, Zhejiang University School of MedicineHangzhouChina
| | - Xin-Yu Cai
- Department of Physiology and Department of Psychiatry, Sir Run Run Shaw Hospital, Zhejiang University School of MedicineHangzhouChina
| | - Yin Wang
- Key Laboratory of Cranial Cerebral Diseases, Department of Neurobiology of Basic Medical College, Ningxia Medical UniversityYinchuanChina
| | - Na Wang
- Department of Physiology and Department of Psychiatry, Sir Run Run Shaw Hospital, Zhejiang University School of MedicineHangzhouChina
| | - Sheng-Jian Ji
- Department of Biology, Southern University of Science and TechnologyShenzhenChina
| | - Wei Chen
- Department of Physiology and Department of Psychiatry, Sir Run Run Shaw Hospital, Zhejiang University School of MedicineHangzhouChina
| | | | - J Julius Zhu
- Department of Pharmacology, University of VirginiaCharlottesvilleUnited States
| | - Chris I De Zeeuw
- Department of Neuroscience, Erasmus MCRotterdamNetherlands
- Netherlands Institute for Neuroscience, Royal Academy of SciencesAmsterdamNetherlands
| | - Ying Shen
- Department of Physiology and Department of Psychiatry, Sir Run Run Shaw Hospital, Zhejiang University School of MedicineHangzhouChina
- International Institutes of Medicine, the Fourth Affiliated Hospital, Zhejiang University School of MedicineYiwuChina
- Key Laboratory of Medical Neurobiology of Zhejiang Province, Zhejiang University School of MedicineHangzhouChina
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6
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Morales A, Mohan R, Chen X, Coffman BL, Bendahmane M, Watch L, West JL, Bakshi S, Traynor JR, Giovannucci DR, Kammermeier PJ, Axelrod D, Currie KP, Smrcka AV, Anantharam A. PACAP and acetylcholine cause distinct Ca2+ signals and secretory responses in chromaffin cells. J Gen Physiol 2023; 155:e202213180. [PMID: 36538657 PMCID: PMC9770323 DOI: 10.1085/jgp.202213180] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 09/22/2022] [Accepted: 11/18/2022] [Indexed: 12/24/2022] Open
Abstract
The adrenomedullary chromaffin cell transduces chemical messages into outputs that regulate end organ function throughout the periphery. At least two important neurotransmitters are released by innervating preganglionic neurons to stimulate exocytosis in the chromaffin cell-acetylcholine (ACh) and pituitary adenylate cyclase activating polypeptide (PACAP). Although PACAP is widely acknowledged as an important secretagogue in this system, the pathway coupling PACAP stimulation to chromaffin cell secretion is poorly understood. The goal of this study is to address this knowledge gap. Here, it is shown that PACAP activates a Gαs-coupled pathway that must signal through phospholipase C ε (PLCε) to drive Ca2+ entry and exocytosis. PACAP stimulation causes a complex pattern of Ca2+ signals in chromaffin cells, leading to a sustained secretory response that is kinetically distinct from the form stimulated by ACh. Exocytosis caused by PACAP is associated with slower release of peptide cargo than exocytosis stimulated by ACh. Importantly, only the secretory response to PACAP, not ACh, is eliminated in cells lacking PLCε expression. The data show that ACh and PACAP, acting through distinct signaling pathways, enable nuanced and variable secretory outputs from chromaffin cells.
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Affiliation(s)
- Alina Morales
- Department of Neurosciences, University of Toledo, Toledo, OH, USA
- Department of Pharmacology, University of Michigan, Ann Arbor, MI, USA
| | - Ramkumar Mohan
- Department of Pharmacology, University of Michigan, Ann Arbor, MI, USA
| | - Xiaohuan Chen
- Department of Neurosciences, University of Toledo, Toledo, OH, USA
| | | | | | - Lester Watch
- Department of Obstetrics and Gynecology, Duke University School of Medicine, Durham, NC, USA
| | - Joshua L. West
- Department of Pharmacology, University of Michigan, Ann Arbor, MI, USA
| | - Shreeya Bakshi
- Department of Pharmacology, University of Michigan, Ann Arbor, MI, USA
| | - John R. Traynor
- Department of Pharmacology, University of Michigan, Ann Arbor, MI, USA
| | | | - Paul J. Kammermeier
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY, USA
| | - Daniel Axelrod
- Department of Physics and LSA Biophysics, University of Michigan, Ann Arbor, MI, USA
| | - Kevin P.M. Currie
- Department of Biomedical Sciences, Cooper Medical School of Rowan University, Camden, NJ, USA
| | - Alan V. Smrcka
- Department of Pharmacology, University of Michigan, Ann Arbor, MI, USA
| | - Arun Anantharam
- Department of Neurosciences, University of Toledo, Toledo, OH, USA
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7
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Botten N, Hodges RR, Bair J, Utheim TP, Serhan CN, Yang M, Dartt DA. Resolvin D2 uses multiple Ca 2+ -dependent signaling pathways to stimulate mucin secretion in rat and human conjunctival goblet cells. J Cell Physiol 2022; 237:3816-3833. [PMID: 36066128 PMCID: PMC9560994 DOI: 10.1002/jcp.30854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 06/28/2022] [Accepted: 07/01/2022] [Indexed: 11/11/2022]
Abstract
The mucin layer of the tear film is produced by goblet cells in the conjunctiva to protect the ocular surface and maintain homeostasis. The pro-resolving lipid mediator resolvin D2 (RvD2) biosynthesized from an omega 3 fatty acid actively terminates inflammation and regulates mucin secretion from conjunctival goblet cells. Our objective was to determine which Ca2+ -dependent signaling pathways RvD2 uses to stimulate conjunctival goblet cell function (CGC). We hypothesize that RvD2 activates multiple intracellular Ca2+ signaling pathways to stimulate CGC secretion. Rat and human CGCs were cultured from conjunctival explants. The amount of RvD2 receptor GPR18/DRV2 message and protein were determined. The intracellular concentration of Ca2+ ([Ca2+ ]i ) was measured in CGCs using a fluorescent Ca2+ dye and mucin secretion was determined by measuring protein secretion enzymatically with a lectin. Goblet cells were incubated with signaling pathway inhibitors before stimulation with RvD2 and [Ca2+ ]i or secretion was measured. In rat and human CGCs RvD2 receptor and in rat CGCs IP3 (a molecule that releases Ca2+ from intracellular organelles) receptors 1-3 were detected. In both species of CGC RvD2 increased [Ca2+ ]i similarly to RvD1. In rat CGCs, the increase in [Ca2+ ]i and secretion stimulated by RvD2 was significantly blocked by inhibitors to phospholipase (PL-) C and IP3 -receptor, but not protein kinase C. Increase in [Ca2+ ]i was blocked by the PLD inhibitor, but not the PLA2 inhibitor. Secretion was blocked by PLA2 inhibitor, but not the PLD inhibitor. An inhibitor of the epidermal growth factor receptor blocked the increase in [Ca2+ ]i by RvD2 in both species of CGCs. In CGCs RvD2 activates multiple intracellular signaling pathways that are Ca2+ -dependent, along with one Ca2+ -independent and one cAMP/protein kinase A-dependent pathway. Activation of these pathways stimulate mucin secretion from rat and human CGCs into the tear film contributing to ocular surface homeostasis and health.
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Affiliation(s)
- Nora Botten
- Schepens Eye Research Institute, Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts, USA
- Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, USA
- Department of Medical Biochemistry, Oslo University Hospital, Oslo, Norway
- Department of Plastic and Reconstructive Surgery, Oslo University Hospital, Oslo, Norway
- Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Robin R. Hodges
- Schepens Eye Research Institute, Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts, USA
- Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, USA
| | - Jeffrey Bair
- Schepens Eye Research Institute, Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts, USA
- Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, USA
| | - Tor P. Utheim
- Schepens Eye Research Institute, Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts, USA
- Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, USA
- Department of Medical Biochemistry, Oslo University Hospital, Oslo, Norway
- Department of Plastic and Reconstructive Surgery, Oslo University Hospital, Oslo, Norway
| | - Charles N. Serhan
- Center for Experimental Therapeutics and Reperfusion Injury, Harvard Medical School, Boston, Massachusetts, USA
- Department of Anesthesiology, Perioperative, and Pain Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Menglu Yang
- Schepens Eye Research Institute, Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts, USA
- Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, USA
| | - Darlene A. Dartt
- Schepens Eye Research Institute, Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts, USA
- Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, USA
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8
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Huang ST, Chen BB, Song ZJ, Tang HL, Hua R, Zhang YM. Unraveling the role of Epac1-SOCS3 signaling in the development of neonatal-CRD-induced visceral hypersensitivity in rats. CNS Neurosci Ther 2022; 28:1393-1408. [PMID: 35702948 PMCID: PMC9344090 DOI: 10.1111/cns.13880] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 05/18/2022] [Accepted: 05/20/2022] [Indexed: 11/28/2022] Open
Abstract
Aims Visceral hypersensitivity in irritable bowel syndrome (IBS) is widespread, but effective therapies for it remain elusive. As a canonical anti‐inflammatory protein, suppressor of cytokine signaling 3 (SOCS3) reportedly relays exchange protein 1 directly activated by cAMP (Epac1) signaling and inhibits the intracellular response to inflammatory cytokines. Despite the inhibitory effect of SOCS3 on the pro‐inflammatory response and neuroinflammation in PVN, the systematic investigation of Epac1‐SOCS3 signaling involved in visceral hypersensitivity remains unknown. This study aimed to explore Epac1‐SOCS3 signaling in the activity of hypothalamic paraventricular nucleus (PVN) corticotropin‐releasing factor (CRF) neurons and visceral hypersensitivity in adult rats experiencing neonatal colorectal distension (CRD). Methods Rats were subjected to neonatal CRD to simulate visceral hypersensitivity to investigate the effect of Epac1‐SOCS3 signaling on PVN CRF neurons. The expression and activity of Epac1 and SOCS3 in nociceptive hypersensitivity were determined by western blot, RT‐PCR, immunofluorescence, radioimmunoassay, electrophysiology, and pharmacology. Results In neonatal‐CRD‐induced visceral hypersensitivity model, Epac1 and SOCS3 expressions were downregulated and IL‐6 levels elevated in PVN. However, infusion of Epac agonist 8‐pCPT in PVN reduced CRF neuronal firing rates, and overexpression of SOCS3 in PVN by AAV‐SOCS3 inhibited the activation of PVN neurons, reduced visceral hypersensitivity, and precluded pain precipitation. Intervention with IL‐6 neutralizing antibody also alleviated the visceral hypersensitivity. In naïve rats, Epac antagonist ESI‐09 in PVN increased CRF neuronal firing. Consistently, genetic knockdown of Epac1 or SOCS3 in PVN potentiated the firing rate of CRF neurons, functionality of HPA axis, and sensitivity of visceral nociception. Moreover, pharmacological intervention with exogenous IL‐6 into PVN simulated the visceral hypersensitivity. Conclusions Inactivation of Epac1‐SOCS3 pathway contributed to the neuroinflammation accompanied by the sensitization of CRF neurons in PVN, precipitating visceral hypersensitivity and pain in rats experiencing neonatal CRD.
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Affiliation(s)
- Si-Ting Huang
- Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, China.,Jiangsu Province Key Laboratory of Anesthesia and Analgesia Application Technology, Xuzhou Medical University, Xuzhou, China.,NMPA Key Laboratory for Research and Evaluation of Narcotic and Psychotropic Drugs, Xuzhou, China
| | - Bin-Bin Chen
- Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, China.,Jiangsu Province Key Laboratory of Anesthesia and Analgesia Application Technology, Xuzhou Medical University, Xuzhou, China.,NMPA Key Laboratory for Research and Evaluation of Narcotic and Psychotropic Drugs, Xuzhou, China
| | - Zhi-Jing Song
- Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, China.,Jiangsu Province Key Laboratory of Anesthesia and Analgesia Application Technology, Xuzhou Medical University, Xuzhou, China.,NMPA Key Laboratory for Research and Evaluation of Narcotic and Psychotropic Drugs, Xuzhou, China
| | - Hui-Li Tang
- Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, China.,Jiangsu Province Key Laboratory of Anesthesia and Analgesia Application Technology, Xuzhou Medical University, Xuzhou, China.,NMPA Key Laboratory for Research and Evaluation of Narcotic and Psychotropic Drugs, Xuzhou, China
| | - Rong Hua
- Department of Emergency, The Affiliated Hospital of Xuzhou Medical University, Xuzhou, China
| | - Yong-Mei Zhang
- Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, China.,Jiangsu Province Key Laboratory of Anesthesia and Analgesia Application Technology, Xuzhou Medical University, Xuzhou, China.,NMPA Key Laboratory for Research and Evaluation of Narcotic and Psychotropic Drugs, Xuzhou, China
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9
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Silva RCMC, Ribeiro JS, da Silva GPD, da Costa LJ, Travassos LH. Autophagy Modulators in Coronavirus Diseases: A Double Strike in Viral Burden and Inflammation. Front Cell Infect Microbiol 2022; 12:845368. [PMID: 35433503 PMCID: PMC9010404 DOI: 10.3389/fcimb.2022.845368] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 03/02/2022] [Indexed: 12/12/2022] Open
Abstract
Coronaviruses are the etiologic agents of several diseases. Coronaviruses of critical medical importance are characterized by highly inflammatory pathophysiology, involving severe pulmonary impairment and infection of multiple cell types within the body. Here, we discuss the interplay between coronaviruses and autophagy regarding virus life cycle, cell resistance, and inflammation, highlighting distinct mechanisms by which autophagy restrains inflammatory responses, especially those involved in coronavirus pathogenesis. We also address different autophagy modulators available and the rationale for drug repurposing as an attractive adjunctive therapy. We focused on pharmaceuticals being tested in clinical trials with distinct mechanisms but with autophagy as a common target. These autophagy modulators act in cell resistance to virus infection and immunomodulation, providing a double-strike to prevent or treat severe disease development and death from coronaviruses diseases.
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Affiliation(s)
- Rafael Cardoso Maciel Costa Silva
- Laboratório de Imunoreceptores e Sinalização Celular, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Jhones Sousa Ribeiro
- Laboratório de Imunoreceptores e Sinalização Celular, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Gustavo Peixoto Duarte da Silva
- Laboratório de Genética e Imunologia das Infecções Virais, Departamento de Virologia, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Luciana Jesus da Costa
- Laboratório de Genética e Imunologia das Infecções Virais, Departamento de Virologia, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Leonardo Holanda Travassos
- Laboratório de Imunoreceptores e Sinalização Celular, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
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10
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Deng K, Thorn P. Presynaptic-like mechanisms and the control of insulin secretion in pancreatic β-cells. Cell Calcium 2022; 104:102585. [DOI: 10.1016/j.ceca.2022.102585] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 03/24/2022] [Accepted: 03/26/2022] [Indexed: 12/18/2022]
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11
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Ni Z, Cheng X. Origin and Isoform Specific Functions of Exchange Proteins Directly Activated by cAMP: A Phylogenetic Analysis. Cells 2021; 10:cells10102750. [PMID: 34685730 PMCID: PMC8534922 DOI: 10.3390/cells10102750] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 10/09/2021] [Accepted: 10/09/2021] [Indexed: 12/21/2022] Open
Abstract
Exchange proteins directly activated by cAMP (EPAC1 and EPAC2) are one of the several families of cellular effectors of the prototypical second messenger cAMP. To understand the origin and molecular evolution of EPAC proteins, we performed a comprehensive phylogenetic analysis of EPAC1 and EPAC2. Our study demonstrates that unlike its cousin PKA, EPAC proteins are only present in multicellular Metazoa. Within the EPAC family, EPAC1 is only associated with chordates, while EPAC2 spans the entire animal kingdom. Despite a much more contemporary origin, EPAC1 proteins show much more sequence diversity among species, suggesting that EPAC1 has undergone more selection and evolved faster than EPAC2. Phylogenetic analyses of the individual cAMP binding domain (CBD) and guanine nucleotide exchange (GEF) domain of EPACs, two most conserved regions between the two isoforms, further reveal that EPAC1 and EPAC2 are closely clustered together within both the larger cyclic nucleotide receptor and RAPGEF families. These results support the notion that EPAC1 and EPAC2 share a common ancestor resulting from a fusion between the CBD of PKA and the GEF from RAPGEF1. On the other hand, the two terminal extremities and the RAS-association (RA) domains show the most sequence diversity between the two isoforms. Sequence diversities within these regions contribute significantly to the isoform-specific functions of EPACs. Importantly, unique isoform-specific sequence motifs within the RA domain have been identified.
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Affiliation(s)
- Zhuofu Ni
- Department of Integrative Biology & Pharmacology, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX 77030, USA;
| | - Xiaodong Cheng
- Department of Integrative Biology & Pharmacology, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX 77030, USA;
- Texas Therapeutics Institute, Institute of Molecular Medicine, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
- Correspondence: ; Tel.: +1-713-500-7487
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12
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Nishi H, Niyonsaba F, Pelleg A, Schulman ES. Enhancement of Mast Cell Degranulation Mediated by Purinergic Receptors' Activation and PI3K Type δ. THE JOURNAL OF IMMUNOLOGY 2021; 207:1001-1008. [PMID: 34330752 DOI: 10.4049/jimmunol.2001002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 05/28/2021] [Indexed: 11/19/2022]
Abstract
Mast cells express multiple metabotropic purinergic P2Y receptor (P2YR) subtypes. Few studies have evaluated their role in human mast cell (HMC) allergic response as quantified by degranulation induced by cross-linking the high-affinity IgE receptor (FcεRI). We have previously shown that extracellular nucleotides modify the FcεRI activation-dependent degranulation in HMCs derived from human lungs, but the mechanism of this action has not been fully delineated. This study was undertaken to determine the mechanism of activation of P2YRs on the degranulation of HMCs and elucidate the specific postreceptor pathways involved. Sensitized LAD2 cells, a human-derived mast cell line, were subjected to a weak allergic stimulation (WAS) using a low concentration of Ag in the absence and presence of P2YR agonists. Only the metabotropic purinergic P2Y11 receptor (P2Y11R) agonist, adenosine 5'-(3-thio)triphosphate (ATPγS), enhanced WAS-induced degranulation resulting in a net 7-fold increase in release (n = 4; p < 0.01). None of the P2YR agonists tested, including high concentrations of ATPγS (1000 μM), enhanced WAS-induced intracellular Ca2+ mobilization, an essential component of activated FcεRI-induced degranulation. Both a PI3K inhibitor and the relevant gene knockout decreased the ATPγS-induced enhancement. The effect of ATPγS was associated with enhanced phosphorylation of PI3K type δ and protein kinase B, but not the phosphoinositide-dependent kinase-1. The effects of ATPγS were dose dependently inhibited by NF157, a P2Y11R antagonist. To our knowledge, these data indicate for the first time that P2YR is linked to enhancement of allergic degranulation in HMC via the PI3K/protein kinase B pathway.
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Affiliation(s)
- Haruhisa Nishi
- Department of Pharmacology, Jikei University School of Medicine, Tokyo, Japan;
| | - François Niyonsaba
- Atopy (Allergy) Research Center, Juntendo University Graduate School of Medicine, Tokyo, Japan.,Faculty of International Liberal Arts, Juntendo University, Tokyo, Japan
| | - Amir Pelleg
- Danmir Therapeutics, LLC, Haverford, PA; and
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13
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Zhen Y, McGaha TL, Finkelman FD, Shao WH. The Akt-mTORC1 pathway mediates Axl receptor tyrosine kinase-induced mesangial cell proliferation. J Leukoc Biol 2021; 111:563-571. [PMID: 34218441 DOI: 10.1002/jlb.2a1220-850rrr] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Glomerulonephritis (GN), an important pathologic feature of many renal diseases, is frequently characterized by mesangial cell proliferation. We and others have previously shown that the TAM family receptor tyrosine kinases Axl, Mer, and Tyro-3 contribute to cell survival, proliferation, migration, and clearance of apoptotic cells (ACs); that Axl contributes to GN by promoting mesangial cell proliferation; and that small molecule inhibition of Axl ameliorates nephrotoxic serum-induced GN in mice. We now show that stimulation of renal mesangial cell Axl causes a modest increase in intracellular Ca2+ and activates NF-κB, mTOR, and the mTOR-containing mTORC1 complex, which phosphorylates the ribosomal protein S6. Axl-induction of Akt activation is upstream of NF-κB and mTOR activation, which are mutually codependent. Axl-induced NF-κB activation leads to Bcl-xl up-regulation. Axl is more important than Mer at mediating AC phagocytosis by mesangial cells, but less important than Mer at mediating phagocytosis of ACs by peritoneal macrophages. Taken together, our data suggest the possibility that Axl mediates mesangial cell phagocytosis of ACs and promotes mesangial cell proliferation by activating NF-κB and mTORC1.
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Affiliation(s)
- Yuxuan Zhen
- Division of Immunology, Allergy and Rheumatology, Department of Internal Medicine, University of Cincinnati, Cincinnati, Ohio, USA
| | - Tracy L McGaha
- Princess Margaret Cancer Center, Tumor Immunotherapy Program, University Health Network, Toronto, ONT, M5G 2M9, Canada.,Department of Immunology, University of Toronto, Toronto, Ontario, Canada
| | - Fred D Finkelman
- Division of Immunology, Allergy and Rheumatology, Department of Internal Medicine, University of Cincinnati, Cincinnati, Ohio, USA.,Division of Immunobiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
| | - Wen-Hai Shao
- Division of Immunology, Allergy and Rheumatology, Department of Internal Medicine, University of Cincinnati, Cincinnati, Ohio, USA
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14
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Acreman S, Zhang Q. Regulation of α-cell glucagon secretion: The role of second messengers. Chronic Dis Transl Med 2021; 8:7-18. [PMID: 35620162 PMCID: PMC9128566 DOI: 10.1016/j.cdtm.2021.06.001] [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: 04/19/2021] [Accepted: 06/15/2021] [Indexed: 11/30/2022] Open
Abstract
Glucagon is a potent glucose‐elevating hormone that is secreted by pancreatic α‐cells. While well‐controlled glucagon secretion plays an important role in maintaining systemic glucose homeostasis and preventing hypoglycaemia, it is increasingly apparent that defects in the regulation of glucagon secretion contribute to impaired counter‐regulation and hyperglycaemia in diabetes. It has therefore been proposed that pharmacological interventions targeting glucagon secretion/signalling can have great potential in improving glycaemic control of patients with diabetes. However, despite decades of research, a consensus on the precise mechanisms of glucose regulation of glucagon secretion is yet to be reached. Second messengers are a group of small intracellular molecules that relay extracellular signals to the intracellular signalling cascade, modulating cellular functions. There is a growing body of evidence that second messengers, such as cAMP and Ca2+, play critical roles in α‐cell glucose‐sensing and glucagon secretion. In this review, we discuss the impact of second messengers on α‐cell electrical activity, intracellular Ca2+ dynamics and cell exocytosis. We highlight the possibility that the interaction between different second messengers may play a key role in the glucose‐regulation of glucagon secretion.
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15
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Cross-Talk Between the Adenylyl Cyclase/cAMP Pathway and Ca 2+ Homeostasis. Rev Physiol Biochem Pharmacol 2021; 179:73-116. [PMID: 33398503 DOI: 10.1007/112_2020_55] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Cyclic AMP and Ca2+ are the first second or intracellular messengers identified, unveiling the cellular mechanisms activated by a plethora of extracellular signals, including hormones. Cyclic AMP generation is catalyzed by adenylyl cyclases (ACs), which convert ATP into cAMP and pyrophosphate. By the way, Ca2+, as energy, can neither be created nor be destroyed; Ca2+ can only be transported, from one compartment to another, or chelated by a variety of Ca2+-binding molecules. The fine regulation of cytosolic concentrations of cAMP and free Ca2+ is crucial in cell function and there is an intimate cross-talk between both messengers to fine-tune the cellular responses. Cancer is a multifactorial disease resulting from a combination of genetic and environmental factors. Frequent cases of cAMP and/or Ca2+ homeostasis remodeling have been described in cancer cells. In those tumoral cells, cAMP and Ca2+ signaling plays a crucial role in the development of hallmarks of cancer, including enhanced proliferation and migration, invasion, apoptosis resistance, or angiogenesis. This review summarizes the cross-talk between the ACs/cAMP and Ca2+ intracellular pathways with special attention to the functional and reciprocal regulation between Orai1 and AC8 in normal and cancer cells.
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16
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Herraiz C, Martínez-Vicente I, Maresca V. The α-melanocyte-stimulating hormone/melanocortin-1 receptor interaction: A driver of pleiotropic effects beyond pigmentation. Pigment Cell Melanoma Res 2021; 34:748-761. [PMID: 33884776 DOI: 10.1111/pcmr.12980] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 03/25/2021] [Accepted: 04/13/2021] [Indexed: 12/21/2022]
Abstract
Melanocortin-1 Receptor (MC1R), when stimulated by alpha-melanocyte-stimulating hormone (α-MSH), is a driver of eumelanogenesis. Brown/black eumelanin is an effective filter against ultraviolet radiation (UVR) and is a scavenger of free radicals. Several polymorphic variants of MC1R are frequent in red-head people. These polymorphisms reduce the ability of MC1R to promote eumelanogenesis after its activation and spontaneous pheomelanogenesis take place. Since pheomelanin can act as an endogenous photosensitizer, people carrying MC1R polymorphisms are more susceptible to skin cancer. Here, we summarize current knowledge on the biology of MC1R beyond its ability to drive eumelanogenesis. We analyze its capacity to cope with oxidative insult and consequent DNA damage. We describe its ability to transduce through different pathways. We start from the canonical pathway, the cAMP/protein kinase A (PKA) pathway mainly involved in promoting eumelanogenesis, and protection from oxidative damage, and we then move on to describe more recent knowledge concerning ERK pathways, phosphoinositide 3-kinase (PI3K) pathway/AKT, and α-MSH/Peroxisome proliferators activated receptor-γ (PPAR-γ) connection. We describe MC1R polymorphic variants associated with melanoma risk which represent an open window of clinical relevance.
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Affiliation(s)
- Cecilia Herraiz
- Department of Biochemistry, Molecular Biology and Immunology, School of Medicine, University of Murcia and Instituto Murciano de Investigación Biosanitaria (IMIB), Murcia, Spain
| | - Idoya Martínez-Vicente
- Department of Biochemistry, Molecular Biology and Immunology, School of Medicine, University of Murcia and Instituto Murciano de Investigación Biosanitaria (IMIB), Murcia, Spain
| | - Vittoria Maresca
- Laboratory of Cutaneous Physiopathology, San Gallicano Dermatological Institute IRCCS, Rome, Italy
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17
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Losada-Barragán M. Physiological effects of nutrients on insulin release by pancreatic beta cells. Mol Cell Biochem 2021; 476:3127-3139. [PMID: 33844157 DOI: 10.1007/s11010-021-04146-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2020] [Accepted: 03/31/2021] [Indexed: 10/21/2022]
Abstract
Obesity and type 2 diabetes (T2D) are growing health problems associated with a loss of insulin sensitivity. Both conditions arise from a long-term energy imbalance, and frequently, lifestyle measures can be useful in its prevention, including physical activity and a healthy diet. Pancreatic β-cells are determinant nutrient sensors that participate in energetic homeostasis needs. However, when pancreatic β-cells are incapable of secreting enough insulin to counteract the reduced sensitivity, the pathology evolves to an insulin resistance condition. The primary nutrient that stimulates insulin secretion is glucose, but also, there are multiple dietary and hormonal factors influencing that response. Many studies of the physiology of β-cells have highlighted the importance of glucose, fructose, amino acids, and free fatty acids on insulin secretion. The present review summarizes recent research on how β-cells respond to the most abundant nutrients that influence insulin secretion. Taken together, understand the subjacent mechanisms of each nutrient on β-cells can help to unravel the effects of mixed variables and complexity in the context of β-cell pathology.
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Affiliation(s)
- Monica Losada-Barragán
- Grupo de investigación en Biología celular y funcional e ingeniería de biomoléculas, Universidad Antonio Nariño-Sede Circunvalar. Cra, 3 Este # 47A - 15, Bl 5, Bogotá, Colombia.
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18
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Chen W, McRoberts JA, Ennes HS, Marvizon JC. cAMP signaling through protein kinase A and Epac2 induces substance P release in the rat spinal cord. Neuropharmacology 2021; 189:108533. [PMID: 33744339 DOI: 10.1016/j.neuropharm.2021.108533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 03/01/2021] [Accepted: 03/11/2021] [Indexed: 11/18/2022]
Abstract
Using neurokinin 1 receptor (NK1R) internalization to measure of substance P release in rat spinal cord slices, we found that it was induced by the adenylyl cyclase (AC) activator forskolin, by the protein kinase A (PKA) activators 6-Bnz-cAMP and 8-Br-cAMP, and by the activator of exchange protein activated by cAMP (Epac) 8-pCPT-2-O-Me-cAMP (CPTOMe-cAMP). Conversely, AC and PKA inhibitors decreased substance P release induced by electrical stimulation of the dorsal root. Therefore, the cAMP signaling pathway mediates substance P release in the dorsal horn. The effects of forskolin and 6-Bnz-cAMP were not additive with NMDA-induced substance P release and were decreased by the NMDA receptor blocker MK-801. In cultured dorsal horn neurons, forskolin increased NMDA-induced Ca2+ entry and the phosphorylation of the NR1 and NR2B subunits of the NMDA receptor. Therefore, cAMP-induced substance P release is mediated by the activating phosphorylation by PKA of NMDA receptors. Voltage-gated Ca2+ channels, but not by TRPV1 or TRPA1, also contributed to cAMP-induced substance P release. Activation of PKA was required for the effects of forskolin and the three cAMP analogs. Epac2 contributed to the effects of forskolin and CPTOMe-cAMP, signaling through a Raf - mitogen-activated protein kinase pathway to activate Ca2+ channels. Epac1 inhibitors induced NK1R internalization independently of substance P release. In rats with latent sensitization to pain, the effect of 6-Bnz-cAMP was unchanged, whereas the effect of forskolin was decreased due to the loss of the stimulatory effect of Epac2. Hence, substance P release induced by cAMP decreases during pain hypersensitivity.
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Affiliation(s)
- Wenling Chen
- Vatche and Tamar Manoukian Division of Digestive Diseases, Department of Medicine, David Geffen School of Medicine at the University of California Los Angeles, Los Angeles, CA, 90095, USA; Veteran Affairs Greater Los Angeles Healthcare System, Los Angeles, CA, 90073, USA
| | - James A McRoberts
- Vatche and Tamar Manoukian Division of Digestive Diseases, Department of Medicine, David Geffen School of Medicine at the University of California Los Angeles, Los Angeles, CA, 90095, USA
| | - Helena S Ennes
- Vatche and Tamar Manoukian Division of Digestive Diseases, Department of Medicine, David Geffen School of Medicine at the University of California Los Angeles, Los Angeles, CA, 90095, USA
| | - Juan Carlos Marvizon
- Vatche and Tamar Manoukian Division of Digestive Diseases, Department of Medicine, David Geffen School of Medicine at the University of California Los Angeles, Los Angeles, CA, 90095, USA; Veteran Affairs Greater Los Angeles Healthcare System, Los Angeles, CA, 90073, USA.
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19
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Chen Y, Fan X, Zhao X, Shen Y, Xu X, Wei L, Wang W, Wei D. cAMP activates calcium signalling via phospholipase C to regulate cellulase production in the filamentous fungus Trichoderma reesei. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:62. [PMID: 33685506 PMCID: PMC7941909 DOI: 10.1186/s13068-021-01914-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Accepted: 02/21/2021] [Indexed: 05/15/2023]
Abstract
BACKGROUND The filamentous fungus Trichoderma reesei is one of the best producers of cellulase and has been widely studied for the production of cellulosic ethanol and bio-based products. We previously reported that Mn2+ and N,N-dimethylformamide (DMF) can stimulate cellulase overexpression via Ca2+ bursts and calcium signalling in T. reesei under cellulase-inducing conditions. To further understand the regulatory networks involved in cellulase overexpression in T. reesei, we characterised the Mn2+/DMF-induced calcium signalling pathway involved in the stimulation of cellulase overexpression. RESULTS We found that Mn2+/DMF stimulation significantly increased the intracellular levels of cAMP in an adenylate cyclase (ACY1)-dependent manner. Deletion of acy1 confirmed that cAMP is crucial for the Mn2+/DMF-stimulated cellulase overexpression in T. reesei. We further revealed that cAMP elevation induces a cytosolic Ca2+ burst, thereby initiating the Ca2+ signal transduction pathway in T. reesei, and that cAMP signalling causes the Ca2+ signalling pathway to regulate cellulase production in T. reesei. Furthermore, using a phospholipase C encoding gene plc-e deletion strain, we showed that the plc-e gene is vital for cellulase overexpression in response to stimulation by both Mn2+ and DMF, and that cAMP induces a Ca2+ burst through PLC-E. CONCLUSIONS The findings of this study reveal the presence of a signal transduction pathway in which Mn2+/DMF stimulation produces cAMP. Increase in the levels of cAMP activates the calcium signalling pathway via phospholipase C to regulate cellulase overexpression under cellulase-inducing conditions. These findings provide insights into the molecular mechanism of the cAMP-PLC-calcium signalling pathway underlying cellulase expression in T. reesei and highlight the potential applications of signal transduction in the regulation of gene expression in fungi.
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Affiliation(s)
- Yumeng Chen
- State Key Lab of Bioreactor Engineering, New World Institute of Biotechnology, East China University of Science and Technology, 130 Meilong Road , P.O.B. 311, Shanghai, 200237, China
| | - Xingjia Fan
- State Key Lab of Bioreactor Engineering, New World Institute of Biotechnology, East China University of Science and Technology, 130 Meilong Road , P.O.B. 311, Shanghai, 200237, China
| | - Xinqing Zhao
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Yaling Shen
- State Key Lab of Bioreactor Engineering, New World Institute of Biotechnology, East China University of Science and Technology, 130 Meilong Road , P.O.B. 311, Shanghai, 200237, China
| | - Xiangyang Xu
- Zaozhuang Jie Nuo Enzyme Co. Ltd., Shandong, China
| | - Liujing Wei
- State Key Lab of Bioreactor Engineering, New World Institute of Biotechnology, East China University of Science and Technology, 130 Meilong Road , P.O.B. 311, Shanghai, 200237, China
| | - Wei Wang
- State Key Lab of Bioreactor Engineering, New World Institute of Biotechnology, East China University of Science and Technology, 130 Meilong Road , P.O.B. 311, Shanghai, 200237, China.
| | - Dongzhi Wei
- State Key Lab of Bioreactor Engineering, New World Institute of Biotechnology, East China University of Science and Technology, 130 Meilong Road , P.O.B. 311, Shanghai, 200237, China
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GRKs and Epac1 Interaction in Cardiac Remodeling and Heart Failure. Cells 2021; 10:cells10010154. [PMID: 33466800 PMCID: PMC7830799 DOI: 10.3390/cells10010154] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 01/06/2021] [Accepted: 01/08/2021] [Indexed: 12/25/2022] Open
Abstract
β-adrenergic receptors (β-ARs) play a major role in the physiological regulation of cardiac function through signaling routes tightly controlled by G protein-coupled receptor kinases (GRKs). Although the acute stimulation of β-ARs and the subsequent production of cyclic AMP (cAMP) have beneficial effects on cardiac function, chronic stimulation of β-ARs as observed under sympathetic overdrive promotes the development of pathological cardiac remodeling and heart failure (HF), a leading cause of mortality worldwide. This is accompanied by an alteration in cAMP compartmentalization and the activation of the exchange protein directly activated by cAMP 1 (Epac1) signaling. Among downstream signals of β-ARs, compelling evidence indicates that GRK2, GRK5, and Epac1 represent attractive therapeutic targets for cardiac disease. Here, we summarize the pathophysiological roles of GRK2, GRK5, and Epac1 in the heart. We focus on their signalosome and describe how under pathological settings, these proteins can cross-talk and are part of scaffolded nodal signaling systems that contribute to a decreased cardiac function and HF development.
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21
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Grebert C, Becq F, Vandebrouck C. Phospholipase C controls chloride-dependent short-circuit current in human bronchial epithelial cells. Am J Physiol Lung Cell Mol Physiol 2020; 320:L205-L219. [PMID: 33236921 DOI: 10.1152/ajplung.00437.2019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Chloride secretion by airway epithelial cells is primordial for water and ion homeostasis and airways surface prevention of infections. This secretion is impaired in several human diseases, including cystic fibrosis, a genetic pathology due to CFTR gene mutations leading to chloride channel defects. A potential therapeutic approach is aiming at increasing chloride secretion either by correcting the mutated CFTR itself or by stimulating non-CFTR chloride channels at the plasma membrane. Here, we studied the role of phospholipase C in regulating the transepithelial chloride secretion in human airway epithelial 16HBE14o- and CFBE cells over-expressing wild type (WT)- or F508del-CFTR. Western blot analysis shows expression of the three endogenous phospholipase C (PLC) isoforms, namely, PLCδ1, PLCγ1, and PLCβ3 in 16HBE14o- cells. In 16HBE14o- cells, we performed Ussing chamber experiments after silencing each of these PLC isoforms or using the PLC inhibitor U73122 or its inactive analogue U73343. Our results show the involvement of PLCβ3 and PLCγ1 in CFTR-dependent short-circuit current activated by forskolin, but not of PLCδ1. In CFBE-WT CFTR and corrected CFBE-F508del CFTR cells, PLCβ3 silencing also inhibits CFTR-dependent current activated by forskolin and UTP-activated calcium-dependent chloride channels (CaCC). Our study supports the importance of PLC in maintaining CFTR-dependent chloride secretion over time, getting maximal CFTR-dependent current and increasing CaCC activation in bronchial epithelial cells.
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Affiliation(s)
- Chloé Grebert
- Laboratoire Signalisation et Transports Ioniques Membranaires, Université de Poitiers, Poitiers, France
| | - Frédéric Becq
- Laboratoire Signalisation et Transports Ioniques Membranaires, Université de Poitiers, Poitiers, France
| | - Clarisse Vandebrouck
- Laboratoire Signalisation et Transports Ioniques Membranaires, Université de Poitiers, Poitiers, France
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22
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Katan M, Cockcroft S. Phospholipase C families: Common themes and versatility in physiology and pathology. Prog Lipid Res 2020; 80:101065. [PMID: 32966869 DOI: 10.1016/j.plipres.2020.101065] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 08/14/2020] [Accepted: 09/17/2020] [Indexed: 12/20/2022]
Abstract
Phosphoinositide-specific phospholipase Cs (PLCs) are expressed in all mammalian cells and play critical roles in signal transduction. To obtain a comprehensive understanding of these enzymes in physiology and pathology, a detailed structural, biochemical, cell biological and genetic information is required. In this review, we cover all these aspects to summarize current knowledge of the entire superfamily. The families of PLCs have expanded from 13 enzymes to 16 with the identification of the atypical PLCs in the human genome. Recent structural insights highlight the common themes that cover not only the substrate catalysis but also the mechanisms of activation. This involves the release of autoinhibitory interactions that, in the absence of stimulation, maintain classical PLC enzymes in their inactive forms. Studies of individual PLCs provide a rich repertoire of PLC function in different physiologies. Furthermore, the genetic studies discovered numerous mutated and rare variants of PLC enzymes and their link to human disease development, greatly expanding our understanding of their roles in diverse pathologies. Notably, substantial evidence now supports involvement of different PLC isoforms in the development of specific cancer types, immune disorders and neurodegeneration. These advances will stimulate the generation of new drugs that target PLC enzymes, and will therefore open new possibilities for treatment of a number of diseases where current therapies remain ineffective.
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Affiliation(s)
- Matilda Katan
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, Gower Street, London WC1E 6BT, UK
| | - Shamshad Cockcroft
- Department of Neuroscience, Physiology and Pharmacology, Division of Biosciences, University College London, 21 University Street, London WC1E 6JJ, UK.
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23
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Robichaux WG, Mei FC, Yang W, Wang H, Sun H, Zhou Z, Milewicz DM, Teng BB, Cheng X. Epac1 (Exchange Protein Directly Activated by cAMP 1) Upregulates LOX-1 (Oxidized Low-Density Lipoprotein Receptor 1) to Promote Foam Cell Formation and Atherosclerosis Development. Arterioscler Thromb Vasc Biol 2020; 40:e322-e335. [PMID: 33054390 DOI: 10.1161/atvbaha.119.314238] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
OBJECTIVE The cAMP second messenger system, a major stress-response pathway, plays essential roles in normal cardiovascular functions and in pathogenesis of heart diseases. Here, we test the hypothesis that the Epac1 (exchange protein directly activated by cAMP 1) acts as a major downstream effector of cAMP signaling to promote atherogenesis and represents a novel therapeutic target. Approach and Results: To ascertain Epac1's function in atherosclerosis development, a triple knockout mouse model (LTe) was generated by crossing Epac1-/- mice with atherosclerosis-prone LDb mice lacking both Ldlr and Apobec1. Deletion of Epac1 led to a significant reduction of atherosclerotic lesion formation as measured by postmortem staining, accompanied by attenuated macrophage/foam cell infiltrations within atherosclerotic plaques as determined by immunofluorescence staining in LTe animals compared with LDb littermates. Primary bone marrow-derived macrophages were isolated from Epac1-null and wild-type mice to investigate the role of Epac1 in lipid uptake and foam cell formation. ox-LDLs (oxidized low-density lipoproteins) stimulation of bone marrow-derived macrophages led to elevated intracellular cAMP and Epac1 levels, whereas an Epac-specific agonist, increased lipid accumulation in wild-type, but not Epac1-null, bone marrow-derived macrophages. Mechanistically, Epac1 acts through PKC (protein kinase C) to upregulate LOX-1 (ox-LDL receptor 1), a major scavenger receptor for ox-LDL uptake, exerting a feedforward mechanism with ox-LDL to increase lipid uptake and propel foam cell formation and atherogenesis. CONCLUSIONS Our study demonstrates a fundamental role of cAMP/Epac1 signaling in vascular remodeling by promoting ox-LDL uptake and foam cell formation during atherosclerosis lesion development. Therefore, Epac1 represents a promising, unexplored therapeutic target for atherosclerosis.
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Affiliation(s)
- William G Robichaux
- Department of Integrative Biology and Pharmacology (W.G.R., F.C.M., W.Y., H.W., X.C.), McGovern Medical School, The University of Texas Health Science Center, Houston.,Texas Therapeutics Institute (W.G.R., F.C.M., W.Y., H.W., X.C.), McGovern Medical School, The University of Texas Health Science Center, Houston.,Brown Foundation Institute of Molecular Medicine (W.G.R., F.C.M., W.Y., H.W., H.S., B.-B.T.), McGovern Medical School, The University of Texas Health Science Center, Houston
| | - Fang C Mei
- Department of Integrative Biology and Pharmacology (W.G.R., F.C.M., W.Y., H.W., X.C.), McGovern Medical School, The University of Texas Health Science Center, Houston.,Texas Therapeutics Institute (W.G.R., F.C.M., W.Y., H.W., X.C.), McGovern Medical School, The University of Texas Health Science Center, Houston.,Brown Foundation Institute of Molecular Medicine (W.G.R., F.C.M., W.Y., H.W., H.S., B.-B.T.), McGovern Medical School, The University of Texas Health Science Center, Houston
| | - Wenli Yang
- Department of Integrative Biology and Pharmacology (W.G.R., F.C.M., W.Y., H.W., X.C.), McGovern Medical School, The University of Texas Health Science Center, Houston.,Texas Therapeutics Institute (W.G.R., F.C.M., W.Y., H.W., X.C.), McGovern Medical School, The University of Texas Health Science Center, Houston.,Brown Foundation Institute of Molecular Medicine (W.G.R., F.C.M., W.Y., H.W., H.S., B.-B.T.), McGovern Medical School, The University of Texas Health Science Center, Houston
| | - Hui Wang
- Department of Integrative Biology and Pharmacology (W.G.R., F.C.M., W.Y., H.W., X.C.), McGovern Medical School, The University of Texas Health Science Center, Houston.,Texas Therapeutics Institute (W.G.R., F.C.M., W.Y., H.W., X.C.), McGovern Medical School, The University of Texas Health Science Center, Houston.,Brown Foundation Institute of Molecular Medicine (W.G.R., F.C.M., W.Y., H.W., H.S., B.-B.T.), McGovern Medical School, The University of Texas Health Science Center, Houston
| | - Hua Sun
- Brown Foundation Institute of Molecular Medicine (W.G.R., F.C.M., W.Y., H.W., H.S., B.-B.T.), McGovern Medical School, The University of Texas Health Science Center, Houston
| | - Zhen Zhou
- Division of Medical Genetics, Department of Internal Medicine (Z.Z., D.M.M.), McGovern Medical School, The University of Texas Health Science Center, Houston
| | - Dianna M Milewicz
- Division of Medical Genetics, Department of Internal Medicine (Z.Z., D.M.M.), McGovern Medical School, The University of Texas Health Science Center, Houston
| | - Ba-Bie Teng
- Brown Foundation Institute of Molecular Medicine (W.G.R., F.C.M., W.Y., H.W., H.S., B.-B.T.), McGovern Medical School, The University of Texas Health Science Center, Houston
| | - Xiaodong Cheng
- Department of Integrative Biology and Pharmacology (W.G.R., F.C.M., W.Y., H.W., X.C.), McGovern Medical School, The University of Texas Health Science Center, Houston.,Texas Therapeutics Institute (W.G.R., F.C.M., W.Y., H.W., X.C.), McGovern Medical School, The University of Texas Health Science Center, Houston
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β-Adrenergic Receptors/Epac Signaling Increases the Size of the Readily Releasable Pool of Synaptic Vesicles Required for Parallel Fiber LTP. J Neurosci 2020; 40:8604-8617. [PMID: 33046543 DOI: 10.1523/jneurosci.0716-20.2020] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 09/25/2020] [Accepted: 10/01/2020] [Indexed: 01/10/2023] Open
Abstract
The second messenger cAMP is an important determinant of synaptic plasticity that is associated with enhanced neurotransmitter release. Long-term potentiation (LTP) at parallel fiber (PF)-Purkinje cell (PC) synapses depends on a Ca2+-induced increase in presynaptic cAMP that is mediated by Ca2+-sensitive adenylyl cyclases. However, the upstream signaling and the downstream targets of cAMP involved in these events remain poorly understood. It is unclear whether cAMP generated by β-adrenergic receptors (βARs) is required for PF-PC LTP, although noradrenergic varicosities are apposed in PF-PC contacts. Guanine nucleotide exchange proteins directly activated by cAMP [Epac proteins (Epac 1-2)] are alternative cAMP targets to protein kinase A (PKA) and Epac2 is abundant in the cerebellum. However, whether Epac proteins participate in PF-PC LTP is not known. Immunoelectron microscopy demonstrated that βARs are expressed in PF boutons. Moreover, activation of these receptors through their agonist isoproterenol potentiated synaptic transmission in cerebellar slices from mice of either sex, an effect that was insensitive to the PKA inhibitors (H-89, KT270) but that was blocked by the Epac inhibitor ESI 05. Interestingly, prior activation of these βARs occluded PF-PC LTP, while the β1AR antagonist metoprolol blocked PF-PC LTP, which was also absent in Epac2 -/- mice. PF-PC LTP is associated with an increase in the size of the readily releasable pool (RRP) of synaptic vesicles, consistent with the isoproterenol-induced increase in vesicle docking in cerebellar slices. Thus, the βAR-mediated modulation of the release machinery and the subsequent increase in the size of the RRP contributes to PF-PC LTP.SIGNIFICANCE STATEMENT G-protein-coupled receptors modulate the release machinery, causing long-lasting changes in synaptic transmission that influence synaptic plasticity. Nevertheless, the mechanisms underlying synaptic responses to β-adrenergic receptor (βAR) activation remain poorly understood. An increase in the number of synaptic vesicles primed for exocytosis accounts for the potentiation of neurotransmitter release driven by βARs. This effect is not mediated by the canonical protein kinase A pathway but rather, through direct activation of the guanine nucleotide exchange protein Epac by cAMP. Interestingly, this βAR signaling via Epac is involved in long term potentiation at cerebellar granule cell-to-Purkinje cell synapses. Thus, the pharmacological activation of βARs modulates synaptic plasticity and opens therapeutic opportunities to control this phenomenon.
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25
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Formoso K, Lezoualc'h F, Mialet-Perez J. Role of EPAC1 Signalosomes in Cell Fate: Friends or Foes? Cells 2020; 9:E1954. [PMID: 32854274 PMCID: PMC7563956 DOI: 10.3390/cells9091954] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 08/21/2020] [Accepted: 08/22/2020] [Indexed: 02/06/2023] Open
Abstract
The compartmentation of signaling processes is accomplished by the assembly of protein complexes called signalosomes. These signaling platforms colocalize enzymes, substrates, and anchoring proteins into specific subcellular compartments. Exchange protein directly activated by cAMP 1 (EPAC1) is an effector of the second messenger, 3',5'-cyclic adenosine monophosphate (cAMP) that is associated with multiple roles in several pathologies including cardiac diseases. Both EPAC1 intracellular localization and molecular partners are key players in the regulation of cell fate, which may have important therapeutic potential. In this review, we summarize the recent findings on EPAC1 structure, regulation, and pharmacology. We describe the importance of EPAC1 subcellular distribution in its biological action, paying special attention to its nuclear localization and mechanism of action leading to cardiomyocyte hypertrophy. In addition, we discuss the role of mitochondrial EPAC1 in the regulation of cell death. Depending on the cell type and stress condition, we present evidence that supports either a protective or detrimental role of EPAC1 activation.
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Affiliation(s)
- Karina Formoso
- INSERM UMR-1048, Institute of Metabolic and Cardiovascular Diseases, and Université de Toulouse III-Paul Sabatier, 31432 Toulouse, France
| | - Frank Lezoualc'h
- INSERM UMR-1048, Institute of Metabolic and Cardiovascular Diseases, and Université de Toulouse III-Paul Sabatier, 31432 Toulouse, France
| | - Jeanne Mialet-Perez
- INSERM UMR-1048, Institute of Metabolic and Cardiovascular Diseases, and Université de Toulouse III-Paul Sabatier, 31432 Toulouse, France
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26
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Itzhakov D, Nitzan Y, Breitbart H. Protein kinase A inhibition induces EPAC-dependent acrosomal exocytosis in human sperm. Asian J Androl 2020; 21:337-344. [PMID: 30632486 PMCID: PMC6628745 DOI: 10.4103/aja.aja_99_18] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
To interact with the egg, the spermatozoon must undergo several biochemical and motility modifications in the female reproductive tract, collectively called capacitation. Only capacitated sperm can undergo acrosomal exocytosis, near or on the egg, a process that allows the sperm to penetrate and fertilize the egg. In the present study, we investigated the involvement of cyclic adenosine monophosphate (cAMP)-dependent processes on acrosomal exocytosis. Inhibition of protein kinase A (PKA) at the end of capacitation induced acrosomal exocytosis. This process is cAMP-dependent; however, the addition of relatively high concentration of the membrane-permeable 8-bromo-cAMP (8Br-cAMP, 0.1 mmol l−1) analog induced significant inhibition of the acrosomal exocytosis. The induction of acrosomal exocytosis by PKA inhibition was significantly inhibited by an exchange protein directly activated by cAMP (EPAC) ESI09 inhibitor. The EPAC selective substrate activated AE at relatively low concentrations (0.02–0.1 μmol l−1), whereas higher concentrations (>5 μmol l−1) were inhibitory to the AE induced by PKA inhibition. Inhibition of PKA revealed about 50% increase in intracellular cAMP levels, conditions under which EPAC can be activated to induce the AE. Induction of AE by activating the actin severing-protein, gelsolin, which causes F-actin dispersion, was inhibited by the EPAC inhibitor. The AE induced by PKA inhibition was mediated by phospholipase C activity but not by the Ca2+-channel, CatSper. Thus, inhibition of PKA at the end of the capacitation process induced EPAC/phospholipase C-dependent acrosomal exocytosis. EPAC mediates F-actin depolymerization and/or activation of effectors downstream to F-actin breakdown that lead to acrosomal exocytosis.
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Affiliation(s)
- Diana Itzhakov
- The Mina and Everard Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel
| | - Yeshayahu Nitzan
- Department of Clinical Laboratory Science, Zefat Academic College, Zefat 1320611, Israel
| | - Haim Breitbart
- The Mina and Everard Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel
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27
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Integration of Rap1 and Calcium Signaling. Int J Mol Sci 2020; 21:ijms21051616. [PMID: 32120817 PMCID: PMC7084553 DOI: 10.3390/ijms21051616] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 02/24/2020] [Accepted: 02/25/2020] [Indexed: 02/07/2023] Open
Abstract
Ca2+ is a universal intracellular signal. The modulation of cytoplasmic Ca2+ concentration regulates a plethora of cellular processes, such as: synaptic plasticity, neuronal survival, chemotaxis of immune cells, platelet aggregation, vasodilation, and cardiac excitation–contraction coupling. Rap1 GTPases are ubiquitously expressed binary switches that alternate between active and inactive states and are regulated by diverse families of guanine nucleotide exchange factors (GEFs) and GTPase-activating proteins (GAPs). Active Rap1 couples extracellular stimulation with intracellular signaling through secondary messengers—cyclic adenosine monophosphate (cAMP), Ca2+, and diacylglycerol (DAG). Much evidence indicates that Rap1 signaling intersects with Ca2+ signaling pathways to control the important cellular functions of platelet activation or neuronal plasticity. Rap1 acts as an effector of Ca2+ signaling when activated by mechanisms involving Ca2+ and DAG-activated (CalDAG-) GEFs. Conversely, activated by other GEFs, such as cAMP-dependent GEF Epac, Rap1 controls cytoplasmic Ca2+ levels. It does so by regulating the activity of Ca2+ signaling proteins such as sarcoendoplasmic reticulum Ca2+-ATPase (SERCA). In this review, we focus on the physiological significance of the links between Rap1 and Ca2+ signaling and emphasize the molecular interactions that may offer new targets for the therapy of Alzheimer’s disease, hypertension, and atherosclerosis, among other diseases.
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28
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Bai T, Yang H, Wang H, Zhi L, Liu T, Cui L, Liu W, Wang Y, Zhang M, Liu Y, Zhang Y. Inhibition of voltage-gated K+ channels mediates docosahexaenoic acid-stimulated insulin secretion in rat pancreatic β-cells. Food Funct 2020; 11:8893-8904. [DOI: 10.1039/d0fo01891k] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Kv channels play a vital role in DHA-augmented insulin secretion through GPR40/AC/cAMP/PLC signaling pathway in rat pancreatic β-cells.
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29
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Abstract
Phospholipase C (PLC) family members constitute a family of diverse enzymes. Thirteen different family members have been cloned. These family members have unique structures that mediate various functions. Although PLC family members all appear to signal through the bi-products of cleaving phospholipids, it is clear that each family member, and at times each isoform, contributes to unique cellular functions. This chapter provides a review of the current literature on PLC. In addition, references have been provided for more in-depth information regarding areas that are not discussed including tyrosine kinase activation of PLC. Understanding the roles of the individual PLC enzymes, and their distinct cellular functions, will lead to a better understanding of the physiological roles of these enzymes in the development of diseases and the maintenance of homeostasis.
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30
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Aktories K, Gierschik P, Heringdorf DMZ, Schmidt M, Schultz G, Wieland T. cAMP guided his way: a life for G protein-mediated signal transduction and molecular pharmacology-tribute to Karl H. Jakobs. Naunyn Schmiedebergs Arch Pharmacol 2019; 392:887-911. [PMID: 31101932 DOI: 10.1007/s00210-019-01650-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Accepted: 04/02/2019] [Indexed: 12/14/2022]
Abstract
Karl H. Jakobs, former editor-in-chief of Naunyn-Schmiedeberg's Archives of Pharmacology and renowned molecular pharmacologist, passed away in April 2018. In this article, his scientific achievements regarding G protein-mediated signal transduction and regulation of canonical pathways are summarized. Particularly, the discovery of inhibitory G proteins for adenylyl cyclase, methods for the analysis of receptor-G protein interactions, GTP supply by nucleoside diphosphate kinases, mechanisms in phospholipase C and phospholipase D activity regulation, as well as the development of the concept of sphingosine-1-phosphate as extra- and intracellular messenger will presented. His seminal scientific and methodological contributions are put in a general and timely perspective to display and honor his outstanding input to the current knowledge in molecular pharmacology.
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Affiliation(s)
- Klaus Aktories
- Institute for Experimental and Clinical Pharmacology and Toxicology, Faculty of Medicine, Albert Ludwigs University, 79104, Freiburg, Germany
| | - Peter Gierschik
- Institute of Pharmacology and Toxicology, Ulm University Medical Center, 89070, Ulm, Germany
| | - Dagmar Meyer Zu Heringdorf
- Institute of General Pharmacology and Toxicology, University Hospital Frankfurt am Main, Goethe University, 60590, Frankfurt am Main, Germany
| | - Martina Schmidt
- Department of Molecular Pharmacology, University of Groningen, 9713AV, Groningen, The Netherlands
| | - Günter Schultz
- Department of Pharmacology, Charité University Medical Center Berlin, Campus Benjamin Franklin, 14195, Berlin, Germany
| | - Thomas Wieland
- Experimental Pharmacology Mannheim (EPM), European Center for Angioscience (ECAS), Medical Faculty Mannheim, Heidelberg University, Ludolf-Krehl-Str. 13 - 17, 68167, Mannheim, Germany.
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31
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Zeng M, Liu J, Yang W, Zhang S, Liu F, Dong Z, Peng Y, Sun L, Xiao L. Identification of key biomarkers in diabetic nephropathy via bioinformatic analysis. J Cell Biochem 2019; 120:8676-8688. [PMID: 30485525 DOI: 10.1002/jcb.28155] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Accepted: 11/09/2018] [Indexed: 01/24/2023]
Abstract
Diabetic nephropathy (DN) is a major cause of end-stage renal disease. Although intense efforts have been made to elucidate the pathogenesis, the molecular mechanisms of DN remain to be clarified. To identify the candidate genes in the progression of DN, microarray datasets GSE30122, GSE30528, and GSE47183 were downloaded from the Gene Expression Omnibus database. The differentially expressed genes (DEGs) were identified, and function enrichment analyses were performed. The protein-protein interaction network was constructed and the module analysis was performed using the Search Tool for the Retrieval of Interacting Genes and Cytoscape. A total of 61 DEGs were identified. The enriched functions and pathways of the DEGs included glomerulus development, extracellular exosome, collagen binding, and the PI3K-Akt signaling pathway. Fifteen hub genes were identified and biological process analysis revealed that these genes were mainly enriched in acute inflammatory response, inflammatory response, and blood vessel development. Correlation analysis between unexplored hub genes and clinical features of DN suggested that COL6A3, MS4A6A,PLCE1, TNNC1, TNNI1, TNN2, and VSIG4 may involve in the progression of DN. In conclusion, DEGs and hub genes identified in this study may deepen our understanding of molecular mechanisms underlying the progression of DN, and provide candidate targets for diagnosis and treatment of DN.
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Affiliation(s)
- Mengru Zeng
- Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Jialu Liu
- Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Wenxia Yang
- Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Shumin Zhang
- Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Fuyou Liu
- Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Zheng Dong
- Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China.,Department of Cellular Biology and Anatomy, Medical College of Georgia at Augusta University and Charlie Norwood VA Medical Center, Augusta, Georgia
| | - Youming Peng
- Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Lin Sun
- Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Li Xiao
- Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
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32
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Botten N, Hodges RR, Li D, Bair JA, Shatos MA, Utheim TP, Serhan CN, Dartt DA. Resolvin D2 elevates cAMP to increase intracellular [Ca 2+] and stimulate secretion from conjunctival goblet cells. FASEB J 2019; 33:8468-8478. [PMID: 31013438 DOI: 10.1096/fj.201802467r] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Under physiologic conditions, conjunctival goblet cells (CGCs) secrete mucins into the tear film to preserve ocular surface homeostasis. Specialized proresolving mediators (SPMs), like resolvins (Rvs), regulate secretion from CGCs and actively terminate inflammation. The purpose of this study was to determine if RvD2 stimulated mucin secretion and to investigate the cellular signaling components. Goblet cells were cultured from rat conjunctiva. Secretion was measured by an enzyme-linked lectin assay, change in intracellular [Ca2+] ([Ca2+]i) using Fura-2, and cellular cAMP levels by ELISA. RvD2 (10-11-10-8 M) stimulated secretion, increased cellular cAMP levels and the [Ca2+]i. RvD2-stimulated increase in [Ca2+]i and secretion was blocked by Ca2+ chelator 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid tetrakis and the PKA inhibitor N-[2-(p-bromocinnamylamino)ethyl]-5-isoquinolinesulfonamide dihydrochloride but not by the cAMP exchange protein inhibitor α-[2-(3-chlorophenyl)hydrazinylidene]-5-(1,1-dimethylethyl)-b-oxo-3-isoxazolepropanenitrile. Forskolin, 3-isobutyl-1-methylxanthine, and 8-bromo-cAMP (8-Br-cAMP) increased [Ca2+]i. Increasing cAMP with 8-Br-cAMP inhibited the increase in [Ca2+]i stimulated by the cAMP-independent agonist cholinergic agonist carbachol. In conclusion, RvD2 uses both cellular cAMP and [Ca2+]i to stimulate glycoconjugate secretion from CGCs, but the interaction of cAMP and [Ca2+]i is context dependent. Thus RvD2 likely assists in the maintenance of the mucous layer of the tear film to sustain ocular surface homeostasis and has potential as a novel treatment for dry eye disease.-Botten, N., Hodges, R. R., Li, D., Bair, J. A., Shatos, M. A., Utheim, T. P., Serhan, C. N., Dartt, D. A. Resolvin D2 elevates cAMP to increase intracellular [Ca2+] and stimulate secretion from conjunctival goblet cells.
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Affiliation(s)
- Nora Botten
- Schepens Eye Research Institute, Massachusetts Eye and Ear-Harvard Medical School, Boston, Massachusetts, USA.,Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, USA.,Department of Medical Biochemistry, Oslo University Hospital, Oslo, Norway.,Department of Plastic and Reconstructive Surgery, Oslo University Hospital, Oslo, Norway.,Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Robin R Hodges
- Schepens Eye Research Institute, Massachusetts Eye and Ear-Harvard Medical School, Boston, Massachusetts, USA.,Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, USA
| | - Dayu Li
- Schepens Eye Research Institute, Massachusetts Eye and Ear-Harvard Medical School, Boston, Massachusetts, USA.,Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, USA
| | - Jeffrey A Bair
- Schepens Eye Research Institute, Massachusetts Eye and Ear-Harvard Medical School, Boston, Massachusetts, USA.,Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, USA
| | - Marie A Shatos
- Schepens Eye Research Institute, Massachusetts Eye and Ear-Harvard Medical School, Boston, Massachusetts, USA.,Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, USA
| | - Tor P Utheim
- Schepens Eye Research Institute, Massachusetts Eye and Ear-Harvard Medical School, Boston, Massachusetts, USA.,Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, USA.,Department of Medical Biochemistry, Oslo University Hospital, Oslo, Norway.,Department of Plastic and Reconstructive Surgery, Oslo University Hospital, Oslo, Norway
| | - Charles N Serhan
- Center for Experimental Therapeutics and Reperfusion Injury, Harvard Medical School, Boston, Massachusetts, USA.,Department of Anesthesiology, Perioperative, and Pain Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Darlene A Dartt
- Schepens Eye Research Institute, Massachusetts Eye and Ear-Harvard Medical School, Boston, Massachusetts, USA.,Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, USA
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33
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Phospho-substrate profiling of Epac-dependent protein kinase C activity. Mol Cell Biochem 2019; 456:167-178. [PMID: 30739223 DOI: 10.1007/s11010-019-03502-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Accepted: 01/22/2019] [Indexed: 02/07/2023]
Abstract
Exchange protein directly activated by cAMP (Epac) and protein kinase A are effectors for cAMP with distinct actions and regulatory mechanisms. Epac is a Rap guanine nucleotide exchange factor that activates Rap1; protein kinase C (PKC) is a major downstream target of Epac-Rap1 signaling that has been implicated in a variety of pathophysiological processes, including cardiac hypertrophy, cancer, and nociceptor sensitization leading to chronic pain. Despite the implication of both Epac and PKC in these processes, few downstream targets of Epac-PKC signaling have been identified. This study characterized the regulation of PKC activity downstream of Epac activation. Using an antibody that recognizes phospho-serine residues within the consensus sequence phosphorylated by PKC, we analyzed the 1-dimensional banding profile of PKC substrate protein phosphorylation from the Neuro2A mouse neuroblastoma cell line. Activation of Epac either indirectly by prostaglandin PGE2, or directly by 8-pCPT-2-O-Me-cAMP-AM (8pCpt), produced distinct PKC phospho-substrate protein bands that were suppressed by co-administration of the Epac inhibitor ESI09. Different PKC isoforms contributed to the induction of individual phospho-substrate bands, as determined using isoform-selective PKC inhibitors. Moreover, the banding profile after Epac activation was altered by disruption of the cytoskeleton, suggesting that the orchestration of Epac-dependent PKC signaling is regulated in part by interactions with the cytoskeleton. The approach described here provides an effective means to characterize Epac-dependent PKC activity.
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34
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Caron-Beaudoin É, Viau R, Sanderson JT. Effects of Neonicotinoid Pesticides on Promoter-Specific Aromatase (CYP19) Expression in Hs578t Breast Cancer Cells and the Role of the VEGF Pathway. ENVIRONMENTAL HEALTH PERSPECTIVES 2018; 126:047014. [PMID: 29701941 PMCID: PMC6071809 DOI: 10.1289/ehp2698] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Revised: 03/23/2018] [Accepted: 03/26/2018] [Indexed: 05/06/2023]
Abstract
BACKGROUND Aromatase (CYP19) is a key enzyme in estrogens biosynthesis. In the mammary gland, CYP19 gene is expressed at low levels under the regulation of its I.4 promoter. In hormone-dependent breast cancer, fibroblast cells surrounding the tumor express increased levels of CYP19 mRNA due to a decrease of I.4 promoter activity and an increase of PII, I.3, and I.7 promoter activity. Little is known about the effects of environmental chemicals on the promoter-specific CYP19 expression. OBJECTIVE We aimed to determine the effects of two neonicotinoids (thiacloprid and imidacloprid) on promoter-specific CYP19 expression in Hs578t breast cancer cells and understand the signaling pathways involved. METHODS Hs578t cells were exposed to various signaling pathway stimulants or neonicotinoids for 24 h. Promoter-specific expression of CYP19 was determined by real-time quantitative polymerase chain reaction and catalytic activity of aromatase by tritiated water release assay. RESULTS To our knowledge, we are the first to demonstrate that the normal I.4 promoter and the breast cancer-relevant PII, I.3, and I.7 promoters of CYP19 are active in these cells. We found that the expression of CYP19 via promoters PII, I.3, and I.7 in Hs578t cells was, in part, dependent on the activation of two VEGF signaling pathways: mitogen-activated protein kinase (MAPK) 1/3 and phospholipase C (PLC). Exposure of Hs578t cells to environmental concentrations of imidacloprid and thiacloprid resulted in a switch in CYP19 promoter usage, involving inhibition of I.4 promoter activity and an increase of PII, I.3, and I.7 promoter-mediated CYP19 expression and aromatase catalytic activity. Greater effects were seen at lower concentrations. Our results suggest that thiacloprid and imidacloprid exert their effects at least partially by inducing the MAPK 1/3 and/or PLC pathways. CONCLUSIONS We demonstrated in vitro that neonicotinoids may stimulate a change in CYP19 promoter usage similar to that observed in patients with hormone-dependent breast cancer. https://doi.org/10.1289/EHP2698.
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Affiliation(s)
- Élyse Caron-Beaudoin
- INRS – Institut Armand-Frappier, Université du Québec, Laval, Quebec, Canada
- Department of Occupational and Environmental Health, School of Public Health, Université de Montréal, Montreal, Quebec, Canada
| | - Rachel Viau
- INRS – Institut Armand-Frappier, Université du Québec, Laval, Quebec, Canada
| | - J Thomas Sanderson
- INRS – Institut Armand-Frappier, Université du Québec, Laval, Quebec, Canada
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Robichaux WG, Cheng X. Intracellular cAMP Sensor EPAC: Physiology, Pathophysiology, and Therapeutics Development. Physiol Rev 2018; 98:919-1053. [PMID: 29537337 PMCID: PMC6050347 DOI: 10.1152/physrev.00025.2017] [Citation(s) in RCA: 138] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Revised: 09/05/2017] [Accepted: 09/06/2017] [Indexed: 12/13/2022] Open
Abstract
This review focuses on one family of the known cAMP receptors, the exchange proteins directly activated by cAMP (EPACs), also known as the cAMP-regulated guanine nucleotide exchange factors (cAMP-GEFs). Although EPAC proteins are fairly new additions to the growing list of cAMP effectors, and relatively "young" in the cAMP discovery timeline, the significance of an EPAC presence in different cell systems is extraordinary. The study of EPACs has considerably expanded the diversity and adaptive nature of cAMP signaling associated with numerous physiological and pathophysiological responses. This review comprehensively covers EPAC protein functions at the molecular, cellular, physiological, and pathophysiological levels; and in turn, the applications of employing EPAC-based biosensors as detection tools for dissecting cAMP signaling and the implications for targeting EPAC proteins for therapeutic development are also discussed.
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Affiliation(s)
- William G Robichaux
- Department of Integrative Biology and Pharmacology, Texas Therapeutics Institute, The Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center , Houston, Texas
| | - Xiaodong Cheng
- Department of Integrative Biology and Pharmacology, Texas Therapeutics Institute, The Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center , Houston, Texas
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36
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Motiani RK, Tanwar J, Raja DA, Vashisht A, Khanna S, Sharma S, Srivastava S, Sivasubbu S, Natarajan VT, Gokhale RS. STIM1 activation of adenylyl cyclase 6 connects Ca 2+ and cAMP signaling during melanogenesis. EMBO J 2018; 37:embj.201797597. [PMID: 29311116 DOI: 10.15252/embj.201797597] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Revised: 11/29/2017] [Accepted: 12/06/2017] [Indexed: 11/09/2022] Open
Abstract
Endoplasmic reticulum (ER)-plasma membrane (PM) junctions form functionally active microdomains that connect intracellular and extracellular environments. While the key role of these interfaces in maintenance of intracellular Ca2+ levels has been uncovered in recent years, the functional significance of ER-PM junctions in non-excitable cells has remained unclear. Here, we show that the ER calcium sensor protein STIM1 (stromal interaction molecule 1) interacts with the plasma membrane-localized adenylyl cyclase 6 (ADCY6) to govern melanogenesis. The physiological stimulus α-melanocyte-stimulating hormone (αMSH) depletes ER Ca2+ stores, thus recruiting STIM1 to ER-PM junctions, which in turn activates ADCY6. Using zebrafish as a model system, we further established STIM1's significance in regulating pigmentation in vivo STIM1 domain deletion studies reveal the importance of Ser/Pro-rich C-terminal region in this interaction. This mechanism of cAMP generation creates a positive feedback loop, controlling the output of the classical αMSH-cAMP-MITF axis in melanocytes. Our study thus delineates a signaling module that couples two fundamental secondary messengers to drive pigmentation. Given the central role of calcium and cAMP signaling pathways, this module may be operative during various other physiological processes and pathological conditions.
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Affiliation(s)
- Rajender K Motiani
- Systems Biology Group, CSIR-Institute of Genomics and Integrative Biology, New Delhi, India
| | - Jyoti Tanwar
- Systems Biology Group, CSIR-Institute of Genomics and Integrative Biology, New Delhi, India
| | - Desingu Ayyappa Raja
- Systems Biology Group, CSIR-Institute of Genomics and Integrative Biology, New Delhi, India.,Academy of Scientific and Innovative Research, New Delhi, India
| | - Ayushi Vashisht
- Systems Biology Group, CSIR-Institute of Genomics and Integrative Biology, New Delhi, India
| | - Shivangi Khanna
- Systems Biology Group, CSIR-Institute of Genomics and Integrative Biology, New Delhi, India.,Academy of Scientific and Innovative Research, New Delhi, India
| | - Sachin Sharma
- Systems Biology Group, CSIR-Institute of Genomics and Integrative Biology, New Delhi, India.,Academy of Scientific and Innovative Research, New Delhi, India
| | - Sonali Srivastava
- Systems Biology Group, CSIR-Institute of Genomics and Integrative Biology, New Delhi, India
| | - Sridhar Sivasubbu
- Systems Biology Group, CSIR-Institute of Genomics and Integrative Biology, New Delhi, India.,Academy of Scientific and Innovative Research, New Delhi, India
| | - Vivek T Natarajan
- Systems Biology Group, CSIR-Institute of Genomics and Integrative Biology, New Delhi, India.,Academy of Scientific and Innovative Research, New Delhi, India
| | - Rajesh S Gokhale
- Systems Biology Group, CSIR-Institute of Genomics and Integrative Biology, New Delhi, India
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Yang W, Mei FC, Cheng X. EPAC1 regulates endothelial annexin A2 cell surface translocation and plasminogen activation. FASEB J 2018; 32:2212-2222. [PMID: 29217666 DOI: 10.1096/fj.201701027r] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Annexins, a family of highly conserved calcium- and phospholipid-binding proteins, play important roles in a wide range of physiologic functions. Among the 12 known annexins in humans, annexin A2 (AnxA2) is one of the most extensively studied and has been implicated in various human diseases. AnxA2 can exist as a monomer or a heterotetrameric complex with S100A10 (P11) and plays a critical role in many cellular processes, including exocytosis, endocytosis, and membrane organization. At the endothelial cell surface, the (AnxA2⋅P11)2 tetramer-acting as a coreceptor for plasminogen and tissue plasminogen activator (tPA)-accelerates tPA-dependent activation of the fibrinolytic protease, plasmin, the enzyme that is responsible for thrombus dissolution and the degradation of fibrin. This study demonstrates that EPAC1 (exchange proteins directly activated by cAMP isoform 1) interacts with AnxA2 and regulates its biologic functions by modulating its membrane translocation in endothelial cells. By using genetic and pharmacologic approaches, we demonstrate that EPAC1-acting via the PLCε-PKC pathway-inhibits AnxA2 surface translocation and plasminogen activation. These results suggest that EPAC1 plays a role in the regulation of fibrinolysis in endothelial cells and may represent a novel therapeutic target for disorders of fibrinolysis.-Yang, W., Mei, F. C., Cheng, X. EPAC1 regulates endothelial annexin A2 cell surface translocation and plasminogen activation.
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Affiliation(s)
- Wenli Yang
- Department of Integrative Biology and Pharmacology, Texas Therapeutics Institute, University of Texas Health Science Center, Houston, Texas, USA
| | - Fang C Mei
- Department of Integrative Biology and Pharmacology, Texas Therapeutics Institute, University of Texas Health Science Center, Houston, Texas, USA
| | - Xiaodong Cheng
- Department of Integrative Biology and Pharmacology, Texas Therapeutics Institute, University of Texas Health Science Center, Houston, Texas, USA
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38
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Sellers ZM, Illek B, Figueira MF, Hari G, Joo NS, Sibley E, Souza-Menezes J, Morales MM, Fischer H, Wine JJ. Impaired PGE2-stimulated Cl- and HCO3- secretion contributes to cystic fibrosis airway disease. PLoS One 2017; 12:e0189894. [PMID: 29281691 PMCID: PMC5744969 DOI: 10.1371/journal.pone.0189894] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2017] [Accepted: 12/04/2017] [Indexed: 12/15/2022] Open
Abstract
Background Airway mucociliary clearance (MCC) is an important defense mechanism against pulmonary infections and is compromised in cystic fibrosis (CF). Cl- and HCO3- epithelial transport are integral to MCC. During pulmonary infections prostaglandin E2 (PGE2) production is abundant. Aim To determine the effect of PGE2 on airway Cl- and HCO3- secretion and MCC in normal and CF airways. Methods We examined PGE2 stimulated MCC, Cl- and HCO3- secretion using ferret trachea, human bronchial epithelial cell cultures (CFBE41o- with wildtype CFTR (CFBE41 WT) or homozygous F508del CFTR (CFBE41 CF) and human normal bronchial submucosal gland cell line (Calu-3) in Ussing chambers with or without pH-stat. Results PGE2 stimulated MCC in a dose-dependent manner and was partially impaired by CFTRinh-172. PGE2-stimulated Cl- current in ferret trachea was partially inhibited by CFTRinh-172, with niflumic acid eliminating the residual current. CFBE41 WT cell monolayers produced a robust Cl- and HCO3- secretory response to PGE2, both of which were completely inhibited by CFTRinh-172. CFBE41 CF cells exhibited no response to PGE2. In Calu-3 cells, PGE2 stimulated Cl- and HCO3- secretion. Cl- secretion was partially inhibited by CFTRinh-172, with additional inhibition by niflumic acid. HCO3- secretion was completely inhibited by CFTRinh-172. Conclusions PGE2 stimulates bronchotracheal MCC and this response is decreased in CF. In CF airway, PGE2-stimulated Cl- and HCO3- conductance is impaired and may contribute to decreased MCC. There remains a CFTR-independent Cl- current in submucosal glands, which if exploited, could represent a means of improving airway Cl- secretion and MCC in CF.
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Affiliation(s)
- Zachary M. Sellers
- Division of Pediatric Gastroenterology, Hepatolfifogy, and Nutrition, Stanford University, Palo Alto, CA, United States of America
- Cystic Fibrosis Research Laboratory, Stanford University, Palo Alto, CA, United States of America
- * E-mail:
| | - Beate Illek
- Children’s Hospital Oakland Research Institute, Oakland, CA, United States of America
| | - Miriam Frankenthal Figueira
- Carlos Chagas Filho Biophysics Institute, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil
- Core for Ecology and Socio Environmental Development, Federal University of Rio de Janeiro, Macaé, RJ, Brazil
| | - Gopika Hari
- Children’s Hospital Oakland Research Institute, Oakland, CA, United States of America
| | - Nam Soo Joo
- Cystic Fibrosis Research Laboratory, Stanford University, Palo Alto, CA, United States of America
| | - Eric Sibley
- Division of Pediatric Gastroenterology, Hepatolfifogy, and Nutrition, Stanford University, Palo Alto, CA, United States of America
| | - Jackson Souza-Menezes
- Carlos Chagas Filho Biophysics Institute, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil
- Core for Ecology and Socio Environmental Development, Federal University of Rio de Janeiro, Macaé, RJ, Brazil
| | - Marcelo M. Morales
- Carlos Chagas Filho Biophysics Institute, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Horst Fischer
- Children’s Hospital Oakland Research Institute, Oakland, CA, United States of America
| | - Jeffrey J. Wine
- Cystic Fibrosis Research Laboratory, Stanford University, Palo Alto, CA, United States of America
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Alenkvist I, Gandasi NR, Barg S, Tengholm A. Recruitment of Epac2A to Insulin Granule Docking Sites Regulates Priming for Exocytosis. Diabetes 2017; 66:2610-2622. [PMID: 28679628 DOI: 10.2337/db17-0050] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Accepted: 06/20/2017] [Indexed: 11/13/2022]
Abstract
Epac is a cAMP-activated guanine nucleotide exchange factor that mediates cAMP signaling in various types of cells, including β-cells, where it is involved in the control of insulin secretion. Upon activation, the protein redistributes to the plasma membrane, but the underlying molecular mechanisms and functional consequences are unclear. Using quantitative high-resolution microscopy, we found that cAMP elevation caused rapid binding of Epac2A to the β-cell plasma membrane, where it accumulated specifically at secretory granules and rendered them more prone to undergo exocytosis. cAMP-dependent membrane binding required the high-affinity cyclic nucleotide-binding (CNB) and Ras association domains, but not the disheveled-Egl-10-pleckstrin domain. Although the N-terminal low-affinity CNB domain (CNB-A) was dispensable for the translocation to the membrane, it was critical for directing Epac2A to the granule sites. Epac1, which lacks the CNB-A domain, was recruited to the plasma membrane but did not accumulate at granules. We conclude that Epac2A controls secretory granule release by binding to the exocytosis machinery, an effect that is enhanced by prior cAMP-dependent accumulation of the protein at the plasma membrane.
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Affiliation(s)
- Ida Alenkvist
- Department of Medical Cell Biology, Uppsala University Biomedical Centre, Uppsala, Sweden
| | - Nikhil R Gandasi
- Department of Medical Cell Biology, Uppsala University Biomedical Centre, Uppsala, Sweden
| | - Sebastian Barg
- Department of Medical Cell Biology, Uppsala University Biomedical Centre, Uppsala, Sweden
| | - Anders Tengholm
- Department of Medical Cell Biology, Uppsala University Biomedical Centre, Uppsala, Sweden
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40
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PACAP signaling in stress: insights from the chromaffin cell. Pflugers Arch 2017; 470:79-88. [PMID: 28965274 DOI: 10.1007/s00424-017-2062-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Revised: 08/21/2017] [Accepted: 08/22/2017] [Indexed: 10/18/2022]
Abstract
Pituitary adenylate cyclase-activating polypeptide (PACAP) was first identified in hypothalamus, based on its ability to elevate cyclic AMP in the anterior pituitary. PACAP has been identified as the adrenomedullary neurotransmitter in stress through a combination of ex vivo, in vivo, and in cellula experiments over the past two decades. PACAP causes catecholamine secretion, and activation of catecholamine biosynthetic enzymes, during episodes of stress in mammals. Features of PACAP signaling allowing stress transduction at the splanchnicoadrenomedullary synapse have yielded insights into the contrasting roles of acetylcholine's and PACAP's actions as first messengers at the chromaffin cell, via differential release at low and high rates of splanchnic nerve firing, and differential signaling pathway engagement leading to catecholamine secretion and chromaffin cell gene transcription. Secretion stimulated by PACAP, via calcium influx independent of action potential generation, is under active investigation in several laboratories both at the chromaffin cell and within autonomic ganglia of both the parasympathetic and sympathetic nervous systems. PACAP is a neurotransmitter important in stress transduction in the central nervous system as well, and is found at stress-transduction nuclei in brain including the paraventricular nucleus of hypothalamus, the amygdala and extended amygdalar nuclei, and the prefrontal cortex. The current status of PACAP as a master regulator of stress signaling in the nervous system derives fundamentally from the establishment of its role as the splanchnicoadrenomedullary transmitter in stress. Experimental elucidation of PACAP action at this synapse remains at the forefront of understanding PACAP's role in stress signaling throughout the nervous system.
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41
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Di J, Tang J, Qian H, Franklin DA, Deisenroth C, Itahana Y, Zheng J, Zhang Y. p53 upregulates PLCε-IP3-Ca 2+ pathway and inhibits autophagy through its target gene Rap2B. Oncotarget 2017; 8:64657-64669. [PMID: 29029384 PMCID: PMC5630284 DOI: 10.18632/oncotarget.18112] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Accepted: 05/08/2017] [Indexed: 01/04/2023] Open
Abstract
The tumor suppressor p53 plays a pivotal role in numerous cellular responses as it regulates cell proliferation, metabolism, cellular growth, and autophagy. In order to identify novel p53 target genes, we utilized an unbiased microarray approach and identified Rap2B as a robust candidate, which belongs to the Ras-related GTP-binding protein superfamily and exhibits increased expression in various human cancers. We demonstrated that p53 increases the intracellular IP3 and Ca2+ levels and decreases the LC3 protein levels through its target gene Rap2B, suggesting that p53 can inhibit the autophagic response triggered by starvation via upregulation of the Rap2B-PLCε-IP3-Ca2+ pathway. As a confirmed target gene of p53, we believe that further investigating potential functions of Rap2B in autophagy and tumorigenesis will provide a novel strategy for cancer therapy.
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Affiliation(s)
- Jiehui Di
- Cancer Institute, Xuzhou Medical University, Xuzhou, Jiangsu, P.R. China
- Department of Radiation Oncology and Lineberger Comprehensive Cancer Center, School of Medicine, the University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Juanjuan Tang
- Cancer Institute, Xuzhou Medical University, Xuzhou, Jiangsu, P.R. China
- Department of Oncology, The Affiliated Hospital of Xuzhou Medical University, Xuzhou Medical University, Xuzhou, Jiangsu, P.R. China
| | - Heya Qian
- Cancer Institute, Xuzhou Medical University, Xuzhou, Jiangsu, P.R. China
| | - Derek A. Franklin
- Department of Radiation Oncology and Lineberger Comprehensive Cancer Center, School of Medicine, the University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Chad Deisenroth
- Department of Radiation Oncology and Lineberger Comprehensive Cancer Center, School of Medicine, the University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- The Hamner Institutes for Health Sciences, Institute for Chemical Safety Sciences, Research Triangle Park, NC, USA
| | - Yoko Itahana
- Department of Radiation Oncology and Lineberger Comprehensive Cancer Center, School of Medicine, the University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Cancer & Stem Cell Biology Program, Duke-NUS Graduate Medical School, Singapore
| | - Junnian Zheng
- Cancer Institute, Xuzhou Medical University, Xuzhou, Jiangsu, P.R. China
- Jiangsu Center for the Collaboration and Innovation of Cancer Biotherapy, Cancer Institute, Xuzhou Medical University, Xuzhou, Jiangsu, P.R. China
- Center of Clinical Oncology and Affiliated Hospital of Xuzhou Medical University, Xuzhou Medical University, Xuzhou, Jiangsu, P.R. China
| | - Yanping Zhang
- Cancer Institute, Xuzhou Medical University, Xuzhou, Jiangsu, P.R. China
- Jiangsu Center for the Collaboration and Innovation of Cancer Biotherapy, Cancer Institute, Xuzhou Medical University, Xuzhou, Jiangsu, P.R. China
- Department of Radiation Oncology and Lineberger Comprehensive Cancer Center, School of Medicine, the University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
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Seino S, Sugawara K, Yokoi N, Takahashi H. β-Cell signalling and insulin secretagogues: A path for improved diabetes therapy. Diabetes Obes Metab 2017; 19 Suppl 1:22-29. [PMID: 28880474 DOI: 10.1111/dom.12995] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Revised: 04/24/2017] [Accepted: 04/27/2017] [Indexed: 12/26/2022]
Abstract
Insulin secretagogues including sulfonylureas, glinides and incretin-related drugs such as dipeptidyl peptidase 4 (DPP-4) inhibitors and glucagon-like peptide-1 receptor agonists are widely used for treatment of type 2 diabetes. In addition, glucokinase activators and G-protein-coupled receptor 40 (GPR40) agonists also have been developed, although the drugs are not clinically usable. These different drugs exert their effects on insulin secretion by different mechanisms. Recent advances in β-cell signalling studies have not only deepened our understanding of insulin secretion but also revealed novel mechanisms of insulin secretagogues. Clarification of the signalling mechanisms of the insulin secretagogues will contribute to improved drug therapy for diabetes.
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Affiliation(s)
- Susumu Seino
- Division of Molecular and Metabolic Medicine, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Kenji Sugawara
- Division of Molecular and Metabolic Medicine, Kobe University Graduate School of Medicine, Kobe, Japan
- Division of Diabetes and Endocrinology, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Norihide Yokoi
- Division of Molecular and Metabolic Medicine, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Harumi Takahashi
- Division of Molecular and Metabolic Medicine, Kobe University Graduate School of Medicine, Kobe, Japan
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da Silva Junior ED, Sato M, Merlin J, Broxton N, Hutchinson DS, Ventura S, Evans BA, Summers RJ. Factors influencing biased agonism in recombinant cells expressing the human α 1A -adrenoceptor. Br J Pharmacol 2017; 174:2318-2333. [PMID: 28444738 DOI: 10.1111/bph.13837] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 04/06/2017] [Accepted: 04/12/2017] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND AND PURPOSE Agonists acting at GPCRs promote biased signalling via Gα or Gβγ subunits, GPCR kinases and β-arrestins. Since the demonstration of biased agonism has implications for drug discovery, it is essential to consider confounding factors contributing to bias. We have examined bias at human α1A -adrenoceptors stably expressed at low levels in CHO-K1 cells, identifying off-target effects at endogenous receptors that contribute to ERK1/2 phosphorylation in response to the agonist oxymetazoline. EXPERIMENTAL APPROACH Intracellular Ca2+ mobilization was monitored in a Flexstation® using Fluo 4-AM. The accumulation of cAMP and ERK1/2 phosphorylation were measured using AlphaScreen® proximity assays, and mRNA expression was measured by RT-qPCR. Ligand bias was determined using the operational model of agonism. KEY RESULTS Noradrenaline, phenylephrine, methoxamine and A61603 increased Ca2+ mobilization, cAMP accumulation and ERK1/2 phosphorylation. However, oxymetazoline showed low efficacy for Ca+2 mobilization, no effect on cAMP generation and high efficacy for ERK1/2 phosphorylation. The apparent functional selectivity of oxymetazoline towards ERK1/2 was related to off-target effects at 5-HT1B receptors endogenously expressed in CHO-K1 cells. Phenylephrine and methoxamine showed genuine bias towards ERK1/2 phosphorylation compared to Ca2+ and cAMP pathways, whereas A61603 displayed bias towards cAMP accumulation compared to ERK1/2 phosphorylation. CONCLUSION AND IMPLICATIONS We have shown that while adrenergic agonists display bias at human α1A -adrenoceptors, the marked bias of oxymetazoline for ERK1/2 phosphorylation originates from off-target effects. Commonly used cell lines express a repertoire of endogenous GPCRs that may confound studies on biased agonism at recombinant receptors.
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Affiliation(s)
| | - Masaaki Sato
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
| | - Jon Merlin
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
| | - Natalie Broxton
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
| | - Dana S Hutchinson
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
| | - Sabatino Ventura
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
| | - Bronwyn A Evans
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
| | - Roger J Summers
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
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Alonso B, Bartolomé-Martín D, Ferrero JJ, Ramírez-Franco J, Torres M, Sánchez-Prieto J. CB1 receptors down-regulate a cAMP/Epac2/PLC pathway to silence the nerve terminals of cerebellar granule cells. J Neurochem 2017; 142:350-364. [PMID: 28445587 DOI: 10.1111/jnc.14059] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Revised: 04/19/2017] [Accepted: 04/19/2017] [Indexed: 01/06/2023]
Abstract
Cannabinoid receptors mediate short-term retrograde inhibition of neurotransmitter release, as well as long-term depression of synaptic transmission at excitatory synapses. The responses of individual nerve terminals in VGLUT1-pHluorin transfected cerebellar granule cells to cannabinoids have shown that prolonged activation of cannabinoid type 1 receptors (CB1Rs) silences a subpopulation of previously active synaptic boutons. Adopting a combined pharmacological and genetic approach to study the molecular mechanisms of CB1R-induced silencing, we found that adenylyl cyclase inhibition decreases cAMP levels while it increases the number of silent synaptic boutons and occludes the induction of further silencing by the cannabinoid agonist HU-210. Guanine nucleotide exchange proteins directly activated by cAMP (Epac proteins) mediate some of the presynaptic effects of cAMP in the potentiation of synaptic transmission. ESI05, a selective Epac2 inhibitor, and U-73122, the specific inhibitor of phospholipase C (PLC), both augment the number of silent synaptic boutons. Moreover, they abolish the capacity of the Epac activator, 8-(4-chlorophenylthio)-2'-O-methyladenosine 3',5'-cyclic monophosphate monosodium hydrate, to prevent HU-210-induced silencing consistent with PLC signaling lying downstream of Epac2 proteins. Furthermore, Rab3-interacting molecule (RIM)1α KO cells have many more basally silent synaptic boutons (12.9 ± 3.5%) than wild-type cells (1.1 ± 0.5%). HU-210 induced further silencing in these mutant cells, although 8-(4-chlorophenylthio)-2'-O-methyladenosine 3',5'-cyclic monophosphate monosodium hydrate only awoke the HU-210-induced silence and not the basally silent synaptic boutons. This behavior can be rescued by expressing RIM1α in RIM1α KO cells, these cells behaving very much like wild-type cells. These findings support the hypothesis that a cAMP/Epac/PLC signaling pathway targeting the release machinery appears to mediate cannabinoid-induced presynaptic silencing.
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Affiliation(s)
- Beatris Alonso
- Departamento de Bioquímica, Facultad de Veterinaria, Universidad Complutense, Madrid, Spain.,Instituto de Investigación Sanitaria del Hospital Clínico San Carlos, Madrid, Spain
| | - David Bartolomé-Martín
- Departamento de Bioquímica, Facultad de Veterinaria, Universidad Complutense, Madrid, Spain.,Instituto de Investigación Sanitaria del Hospital Clínico San Carlos, Madrid, Spain
| | - José Javier Ferrero
- Departamento de Bioquímica, Facultad de Veterinaria, Universidad Complutense, Madrid, Spain.,Instituto de Investigación Sanitaria del Hospital Clínico San Carlos, Madrid, Spain
| | - Jorge Ramírez-Franco
- Departamento de Bioquímica, Facultad de Veterinaria, Universidad Complutense, Madrid, Spain.,Instituto de Investigación Sanitaria del Hospital Clínico San Carlos, Madrid, Spain
| | - Magdalena Torres
- Departamento de Bioquímica, Facultad de Veterinaria, Universidad Complutense, Madrid, Spain.,Instituto de Investigación Sanitaria del Hospital Clínico San Carlos, Madrid, Spain
| | - José Sánchez-Prieto
- Departamento de Bioquímica, Facultad de Veterinaria, Universidad Complutense, Madrid, Spain.,Instituto de Investigación Sanitaria del Hospital Clínico San Carlos, Madrid, Spain
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Galaz-Montoya M, Wright SJ, Rodriguez GJ, Lichtarge O, Wensel TG. β 2-Adrenergic receptor activation mobilizes intracellular calcium via a non-canonical cAMP-independent signaling pathway. J Biol Chem 2017; 292:9967-9974. [PMID: 28442571 DOI: 10.1074/jbc.m117.787119] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 04/24/2017] [Indexed: 11/06/2022] Open
Abstract
Beta adrenergic receptors (βARs) are G-protein-coupled receptors essential for physiological responses to the hormones/neurotransmitters epinephrine and norepinephrine which are found in the nervous system and throughout the body. They are the targets of numerous widely used drugs, especially in the case of the most extensively studied βAR, β2AR, whose ligands are used for asthma and cardiovascular disease. βARs signal through Gαs G-proteins and via activation of adenylyl cyclase and cAMP-dependent protein kinase, but some alternative downstream pathways have also been proposed that could be important for understanding normal physiological functioning of βAR signaling and its disruption in disease. Using fluorescence-based Ca2+ flux assays combined with pharmacology and gene knock-out methods, we discovered a previously unrecognized endogenous pathway in HEK-293 cells whereby β2AR activation leads to robust Ca2+ mobilization from intracellular stores via activation of phospholipase C and opening of inositol trisphosphate (InsP3) receptors. This pathway did not involve cAMP, Gαs, or Gαi or the participation of the other members of the canonical β2AR signaling cascade and, therefore, constitutes a novel signaling mechanism for this receptor. This newly uncovered mechanism for Ca2+ mobilization by β2AR has broad implications for adrenergic signaling, cross-talk with other signaling pathways, and the effects of βAR-directed drugs.
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Affiliation(s)
- Monica Galaz-Montoya
- From the Verna and Marrs McLean Department of Biochemistry and Molecular Biology and
| | - Sara J Wright
- From the Verna and Marrs McLean Department of Biochemistry and Molecular Biology and
| | - Gustavo J Rodriguez
- From the Verna and Marrs McLean Department of Biochemistry and Molecular Biology and
| | - Olivier Lichtarge
- From the Verna and Marrs McLean Department of Biochemistry and Molecular Biology and.,the Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030
| | - Theodore G Wensel
- From the Verna and Marrs McLean Department of Biochemistry and Molecular Biology and
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Park SJ, Ahmad F, Um JH, Brown AL, Xu X, Kang H, Ke H, Feng X, Ryall J, Philp A, Schenk S, Kim MK, Sartorelli V, Chung JH. Specific Sirt1 Activator-mediated Improvement in Glucose Homeostasis Requires Sirt1-Independent Activation of AMPK. EBioMedicine 2017; 18:128-138. [PMID: 28396013 PMCID: PMC5405165 DOI: 10.1016/j.ebiom.2017.03.019] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Revised: 03/10/2017] [Accepted: 03/10/2017] [Indexed: 12/15/2022] Open
Abstract
The specific Sirt1 activator SRT1720 increases mitochondrial function in skeletal muscle, presumably by activating Sirt1. However, Sirt1 gain of function does not increase mitochondrial function, which raises a question about the central role of Sirt1 in SRT1720 action. Moreover, it is believed that the metabolic effects of SRT1720 occur independently of AMP-activated protein kinase (AMPK), an important metabolic regulator that increases mitochondrial function. Here, we show that SRT1720 activates AMPK in a Sirt1-independent manner and SRT1720 activates AMPK by inhibiting a cAMP degrading phosphodiesterase (PDE) in a competitive manner. Inhibiting the cAMP effector protein Epac prevents SRT1720 from activating AMPK or Sirt1 in myotubes. Moreover, SRT1720 does not increase mitochondrial function or improve glucose tolerance in AMPKα2 knockout mice. Interestingly, weight loss induced by SRT1720 is not sufficient to improve glucose tolerance. Therefore, contrary to current belief, the metabolic effects produced by SRT1720 require AMPK, which can be activated independently of Sirt1. SRT1720 activates AMPK in a Sirt1-independent manner. SRT1720 activates AMPK by inhibiting cAMP phosphodiesterase. SRT1720-mediated improvement in glucose homeostasis requires AMPK. Weight loss due to SRT1720 is not sufficient for improved glucose homeostasis.
Obesity has become an epidemic and obesity-related diseases such as type 2 diabetes are on the rise. Therefore, discovering novel therapies for these diseases will have great public health impact. Sirt1 activating compounds such as SRT1720 protect against obesity and glucose intolerance, but the mechanism by which they confer these health benefits has been unclear. We discovered that SRT1720 activates energy sensor AMPK, independent of Sirt1, and increases mitochondrial function and glucose tolerance in an AMPK-dependent manner. SRT1720 activates AMPK by directly inhibiting cAMP phosphodiesterases, suggesting that cAMP phosphodiesterases may be potential drug targets for obesity-related diseases.
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Affiliation(s)
- Sung-Jun Park
- Laboratory of Obesity and Aging Research, Genetics and Developmental Biology Center, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Faiyaz Ahmad
- Translational Medicine Branch, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Jee-Hyun Um
- Laboratory of Obesity and Aging Research, Genetics and Developmental Biology Center, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Alexandra L Brown
- Laboratory of Obesity and Aging Research, Genetics and Developmental Biology Center, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Xihui Xu
- Laboratory of Obesity and Aging Research, Genetics and Developmental Biology Center, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Hyeog Kang
- Laboratory of Obesity and Aging Research, Genetics and Developmental Biology Center, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Hengming Ke
- Department of Biochemistry and Biophysics, The University of North Carolina, Chapel Hill, NC 27599, USA
| | - Xuesong Feng
- Laboratory of Muscle Stem Cells and Gene Regulation, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - James Ryall
- Laboratory of Muscle Stem Cells and Gene Regulation, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Andrew Philp
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom
| | - Simon Schenk
- Department of Orthopedic Surgery, University of California San Diego, La Jolla, CA 92093, USA
| | - Myung K Kim
- Laboratory of Obesity and Aging Research, Genetics and Developmental Biology Center, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Vittorio Sartorelli
- Laboratory of Muscle Stem Cells and Gene Regulation, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Jay H Chung
- Laboratory of Obesity and Aging Research, Genetics and Developmental Biology Center, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA.
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Stallaert W, van der Westhuizen ET, Schönegge AM, Plouffe B, Hogue M, Lukashova V, Inoue A, Ishida S, Aoki J, Le Gouill C, Bouvier M. Purinergic Receptor Transactivation by the β2-Adrenergic Receptor Increases Intracellular Ca 2+ in Nonexcitable Cells. Mol Pharmacol 2017; 91:533-544. [PMID: 28280061 DOI: 10.1124/mol.116.106419] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2016] [Accepted: 03/06/2017] [Indexed: 12/11/2022] Open
Abstract
The β2 adrenergic receptor (β2AR) increases intracellular Ca2+ in a variety of cell types. By combining pharmacological and genetic manipulations, we reveal a novel mechanism through which the β2AR promotes Ca2+ mobilization (pEC50 = 7.32 ± 0.10) in nonexcitable human embryonic kidney (HEK)293S cells. Downregulation of Gs with sustained cholera toxin pretreatment and the use of Gs-null HEK293 (∆Gs-HEK293) cells generated using the clustered regularly interspaced short palindromic repeat-associated protein-9 nuclease (CRISPR/Cas9) system, combined with pharmacological modulation of cAMP formation, revealed a Gs-dependent but cAMP-independent increase in intracellular Ca2+ following β2AR stimulation. The increase in cytoplasmic Ca2+ was inhibited by P2Y purinergic receptor antagonists as well as a dominant-negative mutant form of Gq, a Gq-selective inhibitor, and an inositol 1,4,5-trisphosphate (IP3) receptor antagonist, suggesting a role for this Gq-coupled receptor family downstream of the β2AR activation. Consistent with this mechanism, β2AR stimulation promoted the extracellular release of ATP, and pretreatment with apyrase inhibited the β2AR-promoted Ca2+ mobilization. Together, these data support a model whereby the β2AR stimulates a Gs-dependent release of ATP, which transactivates Gq-coupled P2Y receptors through an inside-out mechanism, leading to a Gq- and IP3-dependent Ca2+ mobilization from intracellular stores. Given that β2AR and P2Y receptors are coexpressed in various tissues, this novel signaling paradigm could be physiologically important and have therapeutic implications. In addition, this study reports the generation and validation of HEK293 cells deleted of Gs using the CRISPR/Cas9 genome editing technology that will undoubtedly be powerful tools to study Gs-dependent signaling.
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Affiliation(s)
- Wayne Stallaert
- Department of Biochemistry (W.S., E.T.v.d.W., A.-M.S., B.P., M.B.) and Institute for Research in Immunology and Cancer (W.S., E.T.v.d.W., A.-M.S., B.P., M.H., V.L., C.L.G., M.B.), Université de Montréal, Montréal, QC, Canada; Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Miyagi, Japan (A.I., S.I., J.A.); Japan Science and Technology Agency, Precursory Research for Embryonic Science and Technology, Kawaguchi, Saitama, Japan (A.I.); and Japan Agency for Medical Research and Development, Core Research for Evolutional Science and Technology, Chiyoda-ku, Tokyo, Japan (J.A.)
| | - Emma T van der Westhuizen
- Department of Biochemistry (W.S., E.T.v.d.W., A.-M.S., B.P., M.B.) and Institute for Research in Immunology and Cancer (W.S., E.T.v.d.W., A.-M.S., B.P., M.H., V.L., C.L.G., M.B.), Université de Montréal, Montréal, QC, Canada; Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Miyagi, Japan (A.I., S.I., J.A.); Japan Science and Technology Agency, Precursory Research for Embryonic Science and Technology, Kawaguchi, Saitama, Japan (A.I.); and Japan Agency for Medical Research and Development, Core Research for Evolutional Science and Technology, Chiyoda-ku, Tokyo, Japan (J.A.)
| | - Anne-Marie Schönegge
- Department of Biochemistry (W.S., E.T.v.d.W., A.-M.S., B.P., M.B.) and Institute for Research in Immunology and Cancer (W.S., E.T.v.d.W., A.-M.S., B.P., M.H., V.L., C.L.G., M.B.), Université de Montréal, Montréal, QC, Canada; Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Miyagi, Japan (A.I., S.I., J.A.); Japan Science and Technology Agency, Precursory Research for Embryonic Science and Technology, Kawaguchi, Saitama, Japan (A.I.); and Japan Agency for Medical Research and Development, Core Research for Evolutional Science and Technology, Chiyoda-ku, Tokyo, Japan (J.A.)
| | - Bianca Plouffe
- Department of Biochemistry (W.S., E.T.v.d.W., A.-M.S., B.P., M.B.) and Institute for Research in Immunology and Cancer (W.S., E.T.v.d.W., A.-M.S., B.P., M.H., V.L., C.L.G., M.B.), Université de Montréal, Montréal, QC, Canada; Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Miyagi, Japan (A.I., S.I., J.A.); Japan Science and Technology Agency, Precursory Research for Embryonic Science and Technology, Kawaguchi, Saitama, Japan (A.I.); and Japan Agency for Medical Research and Development, Core Research for Evolutional Science and Technology, Chiyoda-ku, Tokyo, Japan (J.A.)
| | - Mireille Hogue
- Department of Biochemistry (W.S., E.T.v.d.W., A.-M.S., B.P., M.B.) and Institute for Research in Immunology and Cancer (W.S., E.T.v.d.W., A.-M.S., B.P., M.H., V.L., C.L.G., M.B.), Université de Montréal, Montréal, QC, Canada; Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Miyagi, Japan (A.I., S.I., J.A.); Japan Science and Technology Agency, Precursory Research for Embryonic Science and Technology, Kawaguchi, Saitama, Japan (A.I.); and Japan Agency for Medical Research and Development, Core Research for Evolutional Science and Technology, Chiyoda-ku, Tokyo, Japan (J.A.)
| | - Viktoria Lukashova
- Department of Biochemistry (W.S., E.T.v.d.W., A.-M.S., B.P., M.B.) and Institute for Research in Immunology and Cancer (W.S., E.T.v.d.W., A.-M.S., B.P., M.H., V.L., C.L.G., M.B.), Université de Montréal, Montréal, QC, Canada; Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Miyagi, Japan (A.I., S.I., J.A.); Japan Science and Technology Agency, Precursory Research for Embryonic Science and Technology, Kawaguchi, Saitama, Japan (A.I.); and Japan Agency for Medical Research and Development, Core Research for Evolutional Science and Technology, Chiyoda-ku, Tokyo, Japan (J.A.)
| | - Asuka Inoue
- Department of Biochemistry (W.S., E.T.v.d.W., A.-M.S., B.P., M.B.) and Institute for Research in Immunology and Cancer (W.S., E.T.v.d.W., A.-M.S., B.P., M.H., V.L., C.L.G., M.B.), Université de Montréal, Montréal, QC, Canada; Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Miyagi, Japan (A.I., S.I., J.A.); Japan Science and Technology Agency, Precursory Research for Embryonic Science and Technology, Kawaguchi, Saitama, Japan (A.I.); and Japan Agency for Medical Research and Development, Core Research for Evolutional Science and Technology, Chiyoda-ku, Tokyo, Japan (J.A.)
| | - Satoru Ishida
- Department of Biochemistry (W.S., E.T.v.d.W., A.-M.S., B.P., M.B.) and Institute for Research in Immunology and Cancer (W.S., E.T.v.d.W., A.-M.S., B.P., M.H., V.L., C.L.G., M.B.), Université de Montréal, Montréal, QC, Canada; Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Miyagi, Japan (A.I., S.I., J.A.); Japan Science and Technology Agency, Precursory Research for Embryonic Science and Technology, Kawaguchi, Saitama, Japan (A.I.); and Japan Agency for Medical Research and Development, Core Research for Evolutional Science and Technology, Chiyoda-ku, Tokyo, Japan (J.A.)
| | - Junken Aoki
- Department of Biochemistry (W.S., E.T.v.d.W., A.-M.S., B.P., M.B.) and Institute for Research in Immunology and Cancer (W.S., E.T.v.d.W., A.-M.S., B.P., M.H., V.L., C.L.G., M.B.), Université de Montréal, Montréal, QC, Canada; Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Miyagi, Japan (A.I., S.I., J.A.); Japan Science and Technology Agency, Precursory Research for Embryonic Science and Technology, Kawaguchi, Saitama, Japan (A.I.); and Japan Agency for Medical Research and Development, Core Research for Evolutional Science and Technology, Chiyoda-ku, Tokyo, Japan (J.A.)
| | - Christian Le Gouill
- Department of Biochemistry (W.S., E.T.v.d.W., A.-M.S., B.P., M.B.) and Institute for Research in Immunology and Cancer (W.S., E.T.v.d.W., A.-M.S., B.P., M.H., V.L., C.L.G., M.B.), Université de Montréal, Montréal, QC, Canada; Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Miyagi, Japan (A.I., S.I., J.A.); Japan Science and Technology Agency, Precursory Research for Embryonic Science and Technology, Kawaguchi, Saitama, Japan (A.I.); and Japan Agency for Medical Research and Development, Core Research for Evolutional Science and Technology, Chiyoda-ku, Tokyo, Japan (J.A.)
| | - Michel Bouvier
- Department of Biochemistry (W.S., E.T.v.d.W., A.-M.S., B.P., M.B.) and Institute for Research in Immunology and Cancer (W.S., E.T.v.d.W., A.-M.S., B.P., M.H., V.L., C.L.G., M.B.), Université de Montréal, Montréal, QC, Canada; Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Miyagi, Japan (A.I., S.I., J.A.); Japan Science and Technology Agency, Precursory Research for Embryonic Science and Technology, Kawaguchi, Saitama, Japan (A.I.); and Japan Agency for Medical Research and Development, Core Research for Evolutional Science and Technology, Chiyoda-ku, Tokyo, Japan (J.A.)
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The Epac-Phospholipase Cε Pathway Regulates Endocannabinoid Signaling and Cocaine-Induced Disinhibition of Ventral Tegmental Area Dopamine Neurons. J Neurosci 2017; 37:3030-3044. [PMID: 28209735 DOI: 10.1523/jneurosci.2810-16.2017] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2016] [Revised: 01/26/2017] [Accepted: 02/06/2017] [Indexed: 11/21/2022] Open
Abstract
Exchange protein directly activated by cAMP (Epac) is a direct effector for the ubiquitous second messenger cAMP. Epac activates the phospholipase Cε (PLCε) pathway. PLCβ has been linked to the synthesis of the endocannabinoid 2-arachidonoylglycerol (2-AG). Here, we report that Epac facilitates endocannabinoid-mediated retrograde synaptic depression through activation of PLCε. Intracellular loading of a selective Epac agonist 8-CPT-2Me-cAMP into ventral tegmental area (VTA) dopamine neurons enabled previously ineffective stimuli to induce depolarization-induced suppression of inhibition (DSI) and long-term depression of IPSCs (I-LTD) in the VTA. DSI and I-LTD are mediated by 2-AG since they were blocked by a diacylglycerol lipase inhibitor. The effects of 8-CPT-2Me-cAMP on DSI and I-LTD were absent in Epac2 and PLCε knock-out mice, but remained intact in Epac1 knock-out mice. These results identify a novel mechanism for on-demand synthesis of retrograde signaling 2-AG by the Epac2-PLCε pathway. We investigated the functional significance of Epac2-PLCε-2-AG signaling in regulating inhibitory synaptic plasticity in VTA dopamine neurons induced by in vivo cocaine exposure. We showed that cocaine place conditioning led to a decrease in the frequency and amplitude of spontaneous IPSCs and an increase in action potential firing in wild-type mice, but not in Epac2 or PLCε knock-out mice. Together, these results indicate that the Epac2-PLCε-2-AG signaling cascade contributes to cocaine-induced disinhibition of VTA dopamine neurons.SIGNIFICANCE STATEMENT 2-arachidonoylglycerol (2-AG) is an endogenous cannabinoid that depresses synaptic transmission through stimulation of CB1 receptors. Among the six isoforms of phospholipase C (PLC; PLCβ, PLCγ, PLCδ, PLCε, PLCζ, PLCη), only PLCβ has been linked to 2-AG synthesis. Here we demonstrate that 8-CPT-2Me-cAMP, a selective agonist of the cAMP sensor protein Epac, enhances 2-AG-mediated synaptic depression in ventral tegmental area (VTA) dopamine neurons via activation of PLCε. These results identify a novel mechanism for 2-AG synthesis via activation of the Epac-PLCε pathway. Furthermore, we show that cocaine-induced conditioned place preference and disinhibition of VTA dopamine neurons were impaired in mice lacking Epac or PLCε. Thus, the Epac-PLCε signaling pathway contributes to cocaine-induced disinhibition of VTA dopamine neurons and formation of drug-associated memories.
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49
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Fujita T, Umemura M, Yokoyama U, Okumura S, Ishikawa Y. The role of Epac in the heart. Cell Mol Life Sci 2017; 74:591-606. [PMID: 27549789 PMCID: PMC11107744 DOI: 10.1007/s00018-016-2336-5] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Revised: 07/21/2016] [Accepted: 08/09/2016] [Indexed: 02/08/2023]
Abstract
As one of the most important second messengers, 3',5'-cyclic adenosine monophosphate (cAMP) mediates various extracellular signals including hormones and neurotransmitters, and induces appropriate responses in diverse types of cells. Since cAMP was formerly believed to transmit signals through only two direct target molecules, protein kinase A and the cyclic nucleotide-gated channel, the sensational discovery in 1998 of another novel direct effecter of cAMP [exchange proteins directly activated by cAMP (Epac)] attracted a great deal of scientific interest in cAMP signaling. Numerous studies on Epac have since disclosed its important functions in various tissues in the body. Recently, observations of genetically manipulated mice in various pathogenic models have begun to reveal the in vivo significance of previous in vitro or cellular-level findings. Here, we focused on the function of Epac in the heart. Accumulating evidence has revealed that both Epac1 and Epac2 play important roles in the structure and function of the heart under physiological and pathological conditions. Accordingly, developing the ability to regulate cAMP-mediated signaling through Epac may lead to remarkable new therapies for the treatment of cardiac diseases.
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Affiliation(s)
- Takayuki Fujita
- Cardiovascular Research Institute, Yokohama City University Graduate School of Medicine, Yokohama, Japan.
| | - Masanari Umemura
- Cardiovascular Research Institute, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Utako Yokoyama
- Cardiovascular Research Institute, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Satoshi Okumura
- Cardiovascular Research Institute, Yokohama City University Graduate School of Medicine, Yokohama, Japan
- Tsurumi University School of Dental Medicine, Yokohama, Japan
| | - Yoshihiro Ishikawa
- Cardiovascular Research Institute, Yokohama City University Graduate School of Medicine, Yokohama, Japan.
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50
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Taylor CW. Regulation of IP 3 receptors by cyclic AMP. Cell Calcium 2016; 63:48-52. [PMID: 27836216 PMCID: PMC5471599 DOI: 10.1016/j.ceca.2016.10.005] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Revised: 10/27/2016] [Accepted: 10/27/2016] [Indexed: 01/01/2023]
Abstract
Ca2+ and cAMP are ubiquitous intracellular messengers and interactions between them are commonplace. Here the effects of cAMP on inositol 1,4,5-trisphosphate receptors (IP3Rs) are briefly reviewed. All three subtypes of IP3R are phosphorylated by cAMP-dependent protein kinase (PKA). This potentiates IP3-evoked Ca2+ release through IP3R1 and IP3R2, but probably has little effect on IP3R3. In addition, cAMP can directly sensitize all three IP3R subtypes to IP3. The high concentrations of cAMP required for this PKA-independent modulation of IP3Rs is delivered to them within signalling junctions that include type 6 adenylyl cyclase and IP3R2.
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Affiliation(s)
- Colin W Taylor
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, UK.
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