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Santana Nunez D, Malik AB, Lee Q, Ahn SJ, Coctecon-Murillo A, Lazarko D, Levitan I, Mehta D, Komarova YA. Piezo1 induces endothelial responses to shear stress via soluble adenylyl Cyclase-IP 3R2 circuit. iScience 2023; 26:106661. [PMID: 37168565 PMCID: PMC10164902 DOI: 10.1016/j.isci.2023.106661] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 01/30/2023] [Accepted: 04/07/2023] [Indexed: 05/13/2023] Open
Abstract
Endothelial cells (ECs) continuously sense and adapt to changes in shear stress generated by blood flow. Here, we show that the activation of the mechanosensitive channel Piezo1 by defined shear forces induces Ca2+ entry into the endoplasmic reticulum (ER) via the ER Ca2+ ATPase pump. This entry is followed by inositol trisphosphate receptor 2 (IP3R2)-elicited ER Ca2+ release into the cytosol. The mechanism of ER Ca2+ release involves the generation of cAMP by soluble adenylyl cyclase (sAC), leading to IP3R2-evoked Ca2+ gating. Depleting sAC or IP3R2 prevents ER Ca2+ release and blocks EC alignment in the direction of flow. Overexpression of constitutively active Akt1 restores the shear-induced alignment of ECs lacking Piezo1 or IP3R2, as well as the flow-induced vasodilation in endothelial restricted Piezo1 knockout mice. These studies describe an unknown Piezo1-cAMP-IP3R2 circuit as an essential mechanism activating Akt signaling and inducing adaptive changes in ECs to laminar flow.
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Affiliation(s)
- Dianicha Santana Nunez
- Department of Pharmacology and Regenerative Medicine, the Center for Lung and Vascular Biology, University of Illinois College of Medicine, Chicago, IL, USA
| | - Asrar B. Malik
- Department of Pharmacology and Regenerative Medicine, the Center for Lung and Vascular Biology, University of Illinois College of Medicine, Chicago, IL, USA
| | - Quinn Lee
- Department of Pharmacology and Regenerative Medicine, the Center for Lung and Vascular Biology, University of Illinois College of Medicine, Chicago, IL, USA
| | - Sang Joon Ahn
- Department of Medicine, University of Illinois College of Medicine, Chicago, IL, USA
| | - Arnold Coctecon-Murillo
- Department of Pharmacology and Regenerative Medicine, the Center for Lung and Vascular Biology, University of Illinois College of Medicine, Chicago, IL, USA
| | - Dana Lazarko
- Department of Medicine, University of Illinois College of Medicine, Chicago, IL, USA
| | - Irena Levitan
- Department of Medicine, University of Illinois College of Medicine, Chicago, IL, USA
| | - Dolly Mehta
- Department of Pharmacology and Regenerative Medicine, the Center for Lung and Vascular Biology, University of Illinois College of Medicine, Chicago, IL, USA
| | - Yulia A. Komarova
- Department of Pharmacology and Regenerative Medicine, the Center for Lung and Vascular Biology, University of Illinois College of Medicine, Chicago, IL, USA
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2
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Davies A, Tomas A. Appreciating the potential for GPCR crosstalk with ion channels. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2023; 195:101-120. [PMID: 36707150 DOI: 10.1016/bs.pmbts.2022.06.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
G protein-coupled receptors (GPCRs) are expressed by most tissues in the body and are exploited pharmacologically in a variety of pathological conditions including diabetes, cardiovascular disease, neurological diseases, and cancers. Numerous cell signaling pathways can be regulated by GPCR activation, depending on the specific GPCR, ligand and cell type. Ion channels are among the many effector proteins downstream of these signaling pathways. Saliently, ion channels are also recognized as druggable targets, and there is evidence that their activity may regulate GPCR function via membrane potential and cytoplasmic ion concentration. Overall, there appears to be a large potential for crosstalk between ion channels and GPCRs. This might have implications not only for targeting GPCRs for drug development, but also opens the possibility of co-targeting them with ion channels to achieve improved therapeutic outcomes. In this review, we highlight the large variety of possible GPCR-ion channel crosstalk modes.
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Affiliation(s)
- Amy Davies
- Section of Cell Biology and Functional Genomics, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, United Kingdom
| | - Alejandra Tomas
- Section of Cell Biology and Functional Genomics, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, United Kingdom.
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3
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Leo KT, Chou CL, Yang CR, Park E, Raghuram V, Knepper MA. Bayesian analysis of dynamic phosphoproteomic data identifies protein kinases mediating GPCR responses. Cell Commun Signal 2022; 20:80. [PMID: 35659261 PMCID: PMC9164474 DOI: 10.1186/s12964-022-00892-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 04/28/2022] [Indexed: 11/18/2022] Open
Abstract
Background A major goal in the discovery of cellular signaling networks is to identify regulated phosphorylation sites (“phosphosites”) and map them to the responsible protein kinases. The V2 vasopressin receptor is a G-protein coupled receptor (GPCR) that is responsible for regulation of renal water excretion through control of aquaporin-2-mediated osmotic water transport in kidney collecting duct cells. Genome editing experiments have demonstrated that virtually all vasopressin-triggered phosphorylation changes are dependent on protein kinase A (PKA), but events downstream from PKA are still obscure. Methods Here, we used: 1) Tandem mass tag-based quantitative phosphoproteomics to experimentally track phosphorylation changes over time in native collecting ducts isolated from rat kidneys; 2) a clustering algorithm to classify time course data based on abundance changes and the amino acid sequences surrounding the phosphosites; and 3) Bayes’ Theorem to integrate the dynamic phosphorylation data with multiple prior “omic” data sets covering expression, subcellular location, known kinase activity, and characteristic surrounding sequences to identify a set of protein kinases that are regulated secondary to PKA activation. Results Phosphoproteomic studies revealed 185 phosphosites regulated by vasopressin over 15 min. The resulting groups from the cluster algorithm were integrated with Bayes’ Theorem to produce corresponding ranked lists of kinases likely responsible for each group. The top kinases establish three PKA-dependent protein kinase modules whose regulation mediate the physiological effects of vasopressin at a cellular level. The three modules are 1) a pathway involving several Rho/Rac/Cdc42-dependent protein kinases that control actin cytoskeleton dynamics; 2) mitogen-activated protein kinase and cyclin-dependent kinase pathways that control cell proliferation; and 3) calcium/calmodulin-dependent signaling. Conclusions Our findings identify a novel set of downstream small GTPase effectors and calcium/calmodulin-dependent kinases with potential roles in the regulation of water permeability through actin cytoskeleton rearrangement and aquaporin-2 trafficking. The proposed signaling network provides a stronger hypothesis for the kinases mediating V2 vasopressin receptor responses, encouraging future targeted examination via reductionist approaches. Furthermore, the Bayesian analysis described here provides a template for investigating signaling via other biological systems and GPCRs. Video abstract
Supplementary Information The online version contains supplementary material available at 10.1186/s12964-022-00892-6.
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Arige V, Terry LE, Malik S, Knebel TR, Wagner II LE, Yule DI. CREB regulates the expression of type 1 inositol 1,4,5-trisphosphate receptors. J Cell Sci 2021; 134:jcs258875. [PMID: 34533188 PMCID: PMC8601716 DOI: 10.1242/jcs.258875] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 09/13/2021] [Indexed: 12/16/2022] Open
Abstract
Inositol 1,4,5-trisphosphate (IP3) receptors (IP3Rs) play a central role in regulating intracellular Ca2+ signals in response to a variety of internal and external cues. Dysregulation of IP3R signaling is the underlying cause for numerous pathological conditions. It is well established that the activities of IP3Rs are governed by several post-translational modifications, including phosphorylation by protein kinase A (PKA). However, the long-term effects of PKA activation on expression of IP3R subtypes remains largely unexplored. In this report, we investigate the effects of chronic stimulation and tonic activity of PKA on the expression of IP3R subtypes. We demonstrate that expression of the type 1 IP3R (IP3R1) is augmented upon prolonged activation of PKA or upon ectopic overexpression of cyclic AMP-response element-binding protein (CREB) without altering IP3R2 and IP3R3 abundance. By contrast, inhibition of PKA or blocking CREB diminished IP3R1 expression. We also demonstrate that agonist-induced Ca2+-release mediated by IP3R1 is significantly attenuated upon blocking of CREB. Moreover, CREB - by regulating the expression of KRAS-induced actin-interacting protein (KRAP) - ensures correct localization and licensing of IP3R1. Overall, we report a crucial role for CREB in governing both the expression and correct localization of IP3R1. This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
| | | | | | | | | | - David I. Yule
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY 14642, USA
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5
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Lee Y, Park J, Lee G, Yoon S, Min CK, Kim TG, Yamamoto T, Kim DH, Lee KW, Eom SH. S92 phosphorylation induces structural changes in the N-terminus domain of human mitochondrial calcium uniporter. Sci Rep 2020; 10:9131. [PMID: 32499574 PMCID: PMC7272466 DOI: 10.1038/s41598-020-65994-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Accepted: 05/08/2020] [Indexed: 01/07/2023] Open
Abstract
The mitochondrial calcium uniporter (MCU) plays essential roles in mitochondrial calcium homeostasis and regulates cellular functions, such as energy synthesis, cell growth, and development. Thus, MCU activity is tightly controlled by its regulators as well as post-translational modification, including phosphorylation by protein kinases such as proline-rich tyrosine kinase 2 (Pyk2) and AMP-activated protein kinase (AMPK). In our in vitro kinase assay, the MCU N-terminal domain (NTD) was phosphorylated by protein kinase C isoforms (PKCβII, PKCδ, and PKCε) localized in the mitochondrial matrix. In addition, we found the conserved S92 was phosphorylated by the PKC isoforms. To reveal the structural effect of MCU S92 phosphorylation (S92p), we determined crystal structures of the MCU NTD of S92E and D119A mutants and analysed the molecular dynamics simulation of WT and S92p. We observed conformational changes of the conserved loop2-loop4 (L2-L4 loops) in MCU NTDS92E, NTDD119A, and NTDS92p due to the breakage of the S92-D119 hydrogen bond. The results suggest that the phosphorylation of S92 induces conformational changes as well as enhancements of the negative charges at the L2-L4 loops, which may affect the dimerization of two MCU-EMRE tetramers.
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Affiliation(s)
- Youngjin Lee
- 0000 0001 1033 9831grid.61221.36School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Buk-gu, Gwangju 61005 Republic of Korea ,0000 0001 1033 9831grid.61221.36Steitz Center for Structural Biology, Gwangju Institute of Science and Technology (GIST), Buk-gu, Gwangju 61005 Republic of Korea ,0000 0004 0636 3099grid.249967.7Infection and Immunity Research Laboratory, Metabolic Regulation Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, 34141 Republic of Korea
| | - Jongseo Park
- 0000 0001 1033 9831grid.61221.36School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Buk-gu, Gwangju 61005 Republic of Korea ,0000 0001 1033 9831grid.61221.36Steitz Center for Structural Biology, Gwangju Institute of Science and Technology (GIST), Buk-gu, Gwangju 61005 Republic of Korea
| | - Gihwan Lee
- 0000 0001 0661 1492grid.256681.eDivision of Life Science, Division of Applied Life Science (BK21 Plus), Plant Molecular Biology and Biotechnology Research Center (PMBBRC), Research Institute of Natural Science (RINS), Gyeongsang National University (GNU), 501 Jinju-daero, Jinju, 52828 Republic of Korea
| | - Sanghwa Yoon
- 0000 0001 0661 1492grid.256681.eDivision of Life Science, Division of Applied Life Science (BK21 Plus), Plant Molecular Biology and Biotechnology Research Center (PMBBRC), Research Institute of Natural Science (RINS), Gyeongsang National University (GNU), 501 Jinju-daero, Jinju, 52828 Republic of Korea
| | - Choon Kee Min
- 0000 0001 1033 9831grid.61221.36School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Buk-gu, Gwangju 61005 Republic of Korea ,0000 0001 1033 9831grid.61221.36Systems Biology Research Center, Gwangju Institute of Science and Technology (GIST), Buk-gu, Gwangju 61005 Republic of Korea
| | - Tae Gyun Kim
- 0000 0001 1033 9831grid.61221.36School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Buk-gu, Gwangju 61005 Republic of Korea ,0000 0001 1033 9831grid.61221.36Steitz Center for Structural Biology, Gwangju Institute of Science and Technology (GIST), Buk-gu, Gwangju 61005 Republic of Korea ,0000 0000 9805 2626grid.250464.1Present Address: Molecular Cryo-Electron Microscopy Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna, Kunigami 904-0495 Japan
| | - Takenori Yamamoto
- 0000 0001 1092 3579grid.267335.6Institute for Genome Research, Tokushima University, Kuramotocho-3, Tokushima, 770-8503 Japan ,0000 0001 1092 3579grid.267335.6Faculty of Pharmaceutical Sciences, Tokushima University, Shomachi-1, Tokushima, 770-8505 Japan
| | - Do Han Kim
- 0000 0001 1033 9831grid.61221.36School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Buk-gu, Gwangju 61005 Republic of Korea ,0000 0001 1033 9831grid.61221.36Systems Biology Research Center, Gwangju Institute of Science and Technology (GIST), Buk-gu, Gwangju 61005 Republic of Korea
| | - Keun Woo Lee
- 0000 0001 0661 1492grid.256681.eDivision of Life Science, Division of Applied Life Science (BK21 Plus), Plant Molecular Biology and Biotechnology Research Center (PMBBRC), Research Institute of Natural Science (RINS), Gyeongsang National University (GNU), 501 Jinju-daero, Jinju, 52828 Republic of Korea
| | - Soo Hyun Eom
- 0000 0001 1033 9831grid.61221.36School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Buk-gu, Gwangju 61005 Republic of Korea ,0000 0001 1033 9831grid.61221.36Steitz Center for Structural Biology, Gwangju Institute of Science and Technology (GIST), Buk-gu, Gwangju 61005 Republic of Korea
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6
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Type 3 inositol 1,4,5-trisphosphate receptor: A calcium channel for all seasons. Cell Calcium 2019; 85:102132. [PMID: 31790953 DOI: 10.1016/j.ceca.2019.102132] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 11/21/2019] [Accepted: 11/22/2019] [Indexed: 12/18/2022]
Abstract
Inositol 1,4,5 trisphosphate receptors (ITPRs) are a family of endoplasmic reticulum Ca2+ channels essential for the control of intracellular Ca2+ levels in virtually every mammalian cell type. The three isoforms (ITPR1, ITPR2 and ITPR3) are highly homologous in amino acid sequence, but they differ considerably in terms of biophysical properties, subcellular localization, and tissue distribution. Such differences underscore the variety of cellular responses triggered by each isoform and suggest that the expression/activity of specific isoforms might be linked to particular pathophysiological states. Indeed, recent findings demonstrate that changes in expression of ITPR isoforms are associated with a number of human diseases ranging from fatty liver disease to cancer. ITPR3 is emerging as the isoform that is particularly important in the pathogenesis of various human diseases. Here we review the physiological and pathophysiological roles of ITPR3 in various tissues and the mechanisms by which the expression of this isoform is modulated in health and disease.
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7
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Lock JT, Alzayady KJ, Yule DI, Parker I. All three IP 3 receptor isoforms generate Ca 2+ puffs that display similar characteristics. Sci Signal 2018; 11:11/561/eaau0344. [PMID: 30563861 DOI: 10.1126/scisignal.aau0344] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Inositol 1,4,5-trisphosphate (IP3) evokes Ca2+ release through IP3 receptors (IP3Rs) to generate both local Ca2+ puffs arising from concerted openings of clustered IP3Rs and cell-wide Ca2+ waves. Imaging Ca2+ puffs with single-channel resolution yields information on the localization and properties of native IP3Rs in intact cells, but interpretation has been complicated because cells express varying proportions of three structurally and functionally distinct isoforms of IP3Rs. Here, we used TIRF and light-sheet microscopy to image Ca2+ puffs in HEK-293 cell lines generated by CRISPR-Cas9 technology to express exclusively IP3R type 1, 2, or 3. Photorelease of the IP3 analog i-IP3 in all three cell lines evoked puffs with largely similar mean amplitudes, temporal characteristics, and spatial extents. Moreover, the single-channel Ca2+ flux was similar among isoforms, indicating that clusters of different IP3R isoforms contain comparable numbers of active channels. Our results show that all three IP3R isoforms cluster to generate local Ca2+ puffs and, contrary to findings of divergent properties from in vitro electrophysiological studies, display similar conductances and gating kinetics in intact cells.
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Affiliation(s)
- Jeffrey T Lock
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA 92697, USA.
| | - Kamil J Alzayady
- Department of Pharmacology and Physiology, School of Medicine and Dentistry, University of Rochester Medical Center, 601 Elmwood Avenue, Box 711, Rochester, NY 14642, USA
| | - David I Yule
- Department of Pharmacology and Physiology, School of Medicine and Dentistry, University of Rochester Medical Center, 601 Elmwood Avenue, Box 711, Rochester, NY 14642, USA
| | - Ian Parker
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA 92697, USA.,Department of Physiology and Biophysics, University of California, Irvine, Irvine, CA 92697, USA
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8
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Activation of cyclic GMP-dependent protein kinase blocks alcohol-mediated cell death and calcium disruption in cerebellar granule neurons. Neurosci Lett 2018; 676:108-112. [PMID: 29679679 DOI: 10.1016/j.neulet.2018.04.026] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 04/09/2018] [Accepted: 04/16/2018] [Indexed: 01/10/2023]
Abstract
Alcohol during brain development leads to the widespread neuronal death observed in fetal alcohol spectrum disorders (FASD). In comparison, the mature brain is less vulnerable to alcohol. Studies into maturation-acquired alcohol resistance uncovered a protective mechanism that reduces alcohol-induced neuronal death through nitric oxide-cGMP-cyclic GMP-dependent protein kinase (NO-cGMP-cGK) signaling. However, the downstream processes underlying this neuroprotection remain unclear. Alcohol can disrupt levels of intracellular calcium ([Ca2+]i) in vulnerable neuronal populations to trigger cell death in both in vivo and in vitro models of FASD. Since cGK has been demonstrated to regulate and inhibit intracellular Ca2+ release, we examined the hypothesis that cGK confers alcohol resistance by preventing [Ca2+]i disruptions. Alcohol resistance, determined by neuronal survival after 24 h of alcohol exposure, was examined in primary cerebellar granule neuron (CGN) cultures derived from 5 to 7 day-old neonatal mice with an activator, 8-Br-cGMP, and/or an inhibitor, Rp-8-pCPT-cGMPS, of cGK signaling. Intracellular Ca2+ responses to alcohol were measured by ratiometric Ca2+ imaging in Fura-2-loaded CGN cultures after 8-Br-cGMP treatment. Our results indicate that activating cGK with 8-Br-cGMP before alcohol administration provided neuroprotection, which the cGK inhibitor, Rp-8-pCPT-cGMPS, blocked. Alcohol exposure elevated [Ca2+]i, whereas 8-Br-cGMP pretreatment reduced both the level of the alcohol-induced rise in [Ca2+]i as well as the number of cells that responded to alcohol by increasing [Ca2+]i. These findings associate alcohol resistance, mediated by cGK signaling, to reduction of the persistent and toxic increase in [Ca2+]i from alcohol exposure.
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9
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Ujita S, Sasaki T, Asada A, Funayama K, Gao M, Mikoshiba K, Matsuki N, Ikegaya Y. cAMP-Dependent Calcium Oscillations of Astrocytes: An Implication for Pathology. Cereb Cortex 2018; 27:1602-1614. [PMID: 26803165 DOI: 10.1093/cercor/bhv310] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Astrocytes in various brain regions exhibit spontaneous intracellular calcium elevations both in vitro and in vivo; however, neither the temporal pattern underlying this activity nor its function has been fully evaluated. Here, we utilized a long-term optical imaging technique to analyze the calcium activity of more than 4000 astrocytes in acute hippocampal slices as well as in the neocortex and hippocampus of head-restrained mice. Although astrocytic calcium activity was largely sparse and irregular, we observed a subset of cells in which the fluctuating calcium oscillations repeated at a regular interval of ∼30 s. These intermittent oscillations i) depended on type 2 inositol 1,4,5-trisphosphate receptors; ii) consisted of a complex reverberatory interaction between the soma and processes of individual astrocytes; iii) did not synchronize with those of other astrocytes; iv) did not require neuronal firing; v) were modulated through cAMP-protein kinase A signaling; vi) were facilitated under pathological conditions, such as energy deprivation and epileptiform hyperexcitation; and vii) were associated with enhanced hypertrophy in astrocytic processes, an early hallmark of reactive gliosis, which is observed in ischemia and epilepsy. Therefore, calcium oscillations appear to be associated with a pathological state in astrocytes.
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Affiliation(s)
- Sakiko Ujita
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Takuya Sasaki
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Akiko Asada
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Kenta Funayama
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Mengxuan Gao
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Katsuhiko Mikoshiba
- Laboratory for Developmental Neurobiology, Riken Brain Science Institute, Saitama, Japan
| | - Norio Matsuki
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Yuji Ikegaya
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan.,Center for Information and Neural Networks, Suita City, Osaka, Japan
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10
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Liu X, Wu X, Wang Y, Li Y, Chen X, Yang W, Jiang L. CD47 Promotes Human Glioblastoma Invasion Through Activation of the PI3K/Akt Pathway. Oncol Res 2018; 27:415-422. [PMID: 29321087 PMCID: PMC7848455 DOI: 10.3727/096504018x15155538502359] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Cluster of differentiation 47 (CD47) overexpression is common in various malignancies. This study investigated whether CD47 promotes human glioblastoma invasion and, if so, the underlying mechanisms involved. CD47 expression was found to be stronger in tissues of patients with glioblastoma and in various cancer cell lines than in normal controls. CD47 downregulation via siRNA suppressed invasion in vitro, whereas CD47 overexpression through plasmid transfection exerted the opposite effect. However, overexpression or knocking down of CD47 had no effect on cell proliferation. Moreover, CD47 expression was related to Akt phosphorylation at the cellular molecular level. Suppression of Akt with a specific inhibitor impaired the invasion ability of CD47-overexpressing cells, indicating that stimulation of the PI3K/Akt pathway served as the downstream regulator of CD47-triggered invasion. These results suggest that CD47 might be a useful predictor of poor prognosis and metastasis and a potential target for treating glioblastomas.
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Affiliation(s)
- Xuejian Liu
- Department of Oncology, Linyi Third People's Hospital, Linyi, Shandong, P.R. China
| | - Xia Wu
- Department of Oncology, Linyi Third People's Hospital, Linyi, Shandong, P.R. China
| | - Yanming Wang
- Department of Radiotherapy, Jinan Military Region General Hospital, Jinan, Shandong, P.R. China
| | - Yuhua Li
- Department of Oncology, Linyi Third People's Hospital, Linyi, Shandong, P.R. China
| | - Xiangli Chen
- Department of Oncology, Linyi Third People's Hospital, Linyi, Shandong, P.R. China
| | - Wenchuan Yang
- Department of Oncology, Linyi Third People's Hospital, Linyi, Shandong, P.R. China
| | - Lihua Jiang
- Department of Oncology, Linyi Third People's Hospital, Linyi, Shandong, P.R. China
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11
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Huang X, Jin M, Chen YX, Wang J, Zhai K, Chang Y, Yuan Q, Yao KT, Ji G. ERP44 inhibits human lung cancer cell migration mainly via IP3R2. Aging (Albany NY) 2017; 8:1276-86. [PMID: 27347718 PMCID: PMC4931832 DOI: 10.18632/aging.100984] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 06/10/2016] [Indexed: 12/21/2022]
Abstract
Cancer cell migration is involved in tumour metastasis. However, the relationship between calcium signalling and cancer migration is not well elucidated. In this study, we used the human lung adenocarcinoma A549 cell line to examine the role of endoplasmic reticulum protein 44 (ERP44), which has been reported to regulate calcium release inside of the endoplasmic reticulum (ER), in cell migration. We found that the inositol 1,4,5-trisphosphate receptors (IP3Rs/ITPRs) inhibitor 2-APB significantly inhibited A549 cell migration by inhibiting cell polarization and pseudopodium protrusion, which suggests that Ca2+ is necessary for A549 cell migration. Similarly, the overexpression of ERP44 reduced intracellular Ca2+ release via IP3Rs, altered cell morphology and significantly inhibited the migration of A549 cells. These phenomena were primarily dependent on IP3R2 because wound healing in A549 cells with IP3R2 rather than IP3R1 or IP3R3 siRNA was markedly inhibited. Moreover, the overexpression of ERP44 did not affect the migration of the human neuroblastoma cell line SH-SY5Y, which mainly expresses IP3R1. Based on the above observations, we conclude that ERP44 regulates A549 cell migration mainly via an IP3R2-dependent pathway.
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Affiliation(s)
- Xue Huang
- Cancer Research Institute of Southern Medical University, Guangzhou, China
| | - Meng Jin
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Ying-Xiao Chen
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.,Current address: Department of Molecular and Medical Genetics, Oregon Health and Science University, Portland, OR 97239, USA
| | - Jun Wang
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Kui Zhai
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Yan Chang
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Qi Yuan
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Kai-Tai Yao
- Cancer Research Institute of Southern Medical University, Guangzhou, China
| | - Guangju Ji
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
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12
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Systems-level identification of PKA-dependent signaling in epithelial cells. Proc Natl Acad Sci U S A 2017; 114:E8875-E8884. [PMID: 28973931 DOI: 10.1073/pnas.1709123114] [Citation(s) in RCA: 86] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
G protein stimulatory α-subunit (Gαs)-coupled heptahelical receptors regulate cell processes largely through activation of protein kinase A (PKA). To identify signaling processes downstream of PKA, we deleted both PKA catalytic subunits using CRISPR-Cas9, followed by a "multiomic" analysis in mouse kidney epithelial cells expressing the Gαs-coupled V2 vasopressin receptor. RNA-seq (sequencing)-based transcriptomics and SILAC (stable isotope labeling of amino acids in cell culture)-based quantitative proteomics revealed a complete loss of expression of the water-channel gene Aqp2 in PKA knockout cells. SILAC-based quantitative phosphoproteomics identified 229 PKA phosphorylation sites. Most of these PKA targets are thus far unannotated in public databases. Surprisingly, 1,915 phosphorylation sites with the motif x-(S/T)-P showed increased phosphooccupancy, pointing to increased activity of one or more MAP kinases in PKA knockout cells. Indeed, phosphorylation changes associated with activation of ERK2 were seen in PKA knockout cells. The ERK2 site is downstream of a direct PKA site in the Rap1GAP, Sipa1l1, that indirectly inhibits Raf1. In addition, a direct PKA site that inhibits the MAP kinase kinase kinase Map3k5 (ASK1) is upstream of JNK1 activation. The datasets were integrated to identify a causal network describing PKA signaling that explains vasopressin-mediated regulation of membrane trafficking and gene transcription. The model predicts that, through PKA activation, vasopressin stimulates AQP2 exocytosis by inhibiting MAP kinase signaling. The model also predicts that, through PKA activation, vasopressin stimulates Aqp2 transcription through induction of nuclear translocation of the acetyltransferase EP300, which increases histone H3K27 acetylation of vasopressin-responsive genes (confirmed by ChIP-seq).
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Ren G, Zhou Y, Liang G, Yang B, Yang M, King A, Wei H. General Anesthetics Regulate Autophagy via Modulating the Inositol 1,4,5-Trisphosphate Receptor: Implications for Dual Effects of Cytoprotection and Cytotoxicity. Sci Rep 2017; 7:12378. [PMID: 28959036 PMCID: PMC5620053 DOI: 10.1038/s41598-017-11607-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 08/23/2017] [Indexed: 02/07/2023] Open
Abstract
General anesthetics are both neuroprotective and neurotoxic with unclear mechanisms. General anesthetics may control cell survival via their effects on autophagy by activation of type 1 inositol triphosphate receptor (InsP3R-1). DT40 or SH-SY5Y cells with only or over 99% expression of InsP3R-1 were treated with isoflurane or propofol. Cell viability was determined by MTT reduction or LDH release assays. Apoptosis was determined by measuring Caspase-3 or by TUNEL assay. Autophagy activity was determined by measuring LC3 II and P62. We evaluated mitochondrial integrity using MitoTracker Green and cytosolic ATP levels. Fura2-AM was used to measure the concentrations of cytosolic calcium ([Ca2+]c). Propofol significantly increased peak and integrated calcium response (P < 0.001) in cells with InsP3R-1 but not in cells with triple knockout of InsP3R. Both propofol and isoflurane increased autophagy induction (P < 0.05) in an mTOR- and InsP3R- activity dependent manner. Short exposure to propofol adequately activated InsP3-1 to provide sufficient autophagy for cytoprotection, while prolonged exposure to propofol induced cell apoptosis via impairment of autophagy flux through over activation of InsP3-1. Propofol damaged mitochondria and decreased cytosolic ATP. The effects of general anesthetics on apoptosis and autophagy are closely integrated; both are caused by differential activation of the type 1 InsP3R.
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Affiliation(s)
- Gongyi Ren
- Department of Anesthesiology and Critical Care, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Yachun Zhou
- Department of Anesthesiology and Critical Care, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA.,Department of Anesthesiology, Shanghai General Hospital, Shanghai Jiaotong University, Shanghai, China
| | - Ge Liang
- Department of Anesthesiology and Critical Care, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Bin Yang
- Department of Anesthesiology and Critical Care, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA.,Department of Anesthesiology, Shanghai General Hospital, Shanghai Jiaotong University, Shanghai, China
| | - Meirong Yang
- Department of Anesthesiology and Critical Care, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA.,Department of Anesthesiology, Shanghai General Hospital, Shanghai Jiaotong University, Shanghai, China
| | - Alexander King
- Department of Anesthesiology and Critical Care, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Huafeng Wei
- Department of Anesthesiology and Critical Care, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA.
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Li Z, Xu X, Huang W, Qian H. Free Fatty Acid Receptor 1 (FFAR1) as an Emerging Therapeutic Target for Type 2 Diabetes Mellitus: Recent Progress and Prevailing Challenges. Med Res Rev 2017; 38:381-425. [DOI: 10.1002/med.21441] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Revised: 01/23/2017] [Accepted: 02/14/2017] [Indexed: 12/19/2022]
Affiliation(s)
- Zheng Li
- Center of Drug Discovery, State Key Laboratory of Natural Medicines; China Pharmaceutical University; 24 Tongjiaxiang Nanjing 210009 P.R. China
| | - Xue Xu
- Key Laboratory of Drug Quality Control and Pharmacovigilance; China Pharmaceutical University; 24 Tongjiaxiang Nanjing 210009 P.R. China
| | - Wenlong Huang
- Center of Drug Discovery, State Key Laboratory of Natural Medicines; China Pharmaceutical University; 24 Tongjiaxiang Nanjing 210009 P.R. China
- Jiangsu Key Laboratory of Drug Discovery for Metabolic Disease; China Pharmaceutical University; 24 Tongjiaxiang Nanjing 210009 P.R. China
| | - Hai Qian
- Center of Drug Discovery, State Key Laboratory of Natural Medicines; China Pharmaceutical University; 24 Tongjiaxiang Nanjing 210009 P.R. China
- Jiangsu Key Laboratory of Drug Discovery for Metabolic Disease; China Pharmaceutical University; 24 Tongjiaxiang Nanjing 210009 P.R. China
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ISOBE K, YOKOYAMA T, MORIGUCHI-MORI K, KUMAGAI M, SATOH YI, KUJI A, SAINO T. Role of pituitary adenylyl cyclase-activating polypeptide in intracellular calcium dynamics of neurons and satellite cells in rat superior cervical ganglia . Biomed Res 2017; 38:99-109. [DOI: 10.2220/biomedres.38.99] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Kanako ISOBE
- Department of Anatomy (Cell Biology), Iwate Medical University
- Division of Special Care Dentistry, Department of Developmental Oral Health Science, School of Dentistry, Iwate Medical University
| | - Takuya YOKOYAMA
- Department of Anatomy (Cell Biology), Iwate Medical University
| | - Kasumi MORIGUCHI-MORI
- Division of Special Care Dentistry, Department of Developmental Oral Health Science, School of Dentistry, Iwate Medical University
| | - Miho KUMAGAI
- Division of Special Care Dentistry, Department of Developmental Oral Health Science, School of Dentistry, Iwate Medical University
| | - Yoh-ichi SATOH
- Department of Anatomy (Cell Biology), Iwate Medical University
- Department of Medical Education, Iwate Medical University
| | - Akiyoshi KUJI
- Division of Special Care Dentistry, Department of Developmental Oral Health Science, School of Dentistry, Iwate Medical University
| | - Tomoyuki SAINO
- Department of Anatomy (Cell Biology), Iwate Medical University
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Wang X, Wang M, Jia Z, Wang H, Jiang S, Chen H, Wang L, Song L. Ocean acidification stimulates alkali signal pathway: A bicarbonate sensing soluble adenylyl cyclase from oyster Crassostrea gigas mediates physiological changes induced by CO 2 exposure. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2016; 181:124-135. [PMID: 27837685 DOI: 10.1016/j.aquatox.2016.11.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Revised: 10/26/2016] [Accepted: 11/02/2016] [Indexed: 06/06/2023]
Abstract
Ocean acidification (OA) has been demonstrated to have severe effects on marine organisms, especially marine calcifiers. However, the impacts of OA on the physiology of marine calcifiers and the underlying mechanisms remain unclear. Soluble adenylyl cyclase (sAC) is an acid-base sensor in response to [HCO3-] and an intracellular source of cyclic AMP (cAMP). In the present study, an ortholog of sAC was identified from pacific oyster Crassostrea gigas (designated as CgsAC) and the catalytic region of CgsAC was cloned and expressed. Similar to the native CgsAC from gill tissues, the recombinant CgsAC protein (rCgsAC) exhibited [HCO3-] mediated cAMP-forming activity, which could be inhibited by a small molecule KH7. After 16days of CO2 exposure (pH=7.50), the mRNA transcripts of CgsAC increased in muscle, mantle, hepatopancreas, gill, male gonad and haemocytes, and two truncated CgsAC forms of 45kD and 20kD were produced. Cytosolic CgsAC could be translocated from the cytoplasm and nuclei to the membrane in response to CO2 exposure. Besides, CO2 exposure could increase the production of cAMP and intracellular pH of haemocytes, which was regulated by CgsAC (p<0.05), suggesting the existence of a [HCO3-]/CgsAC/cAMP signal pathway in oyster. The elevated CO2 could induce an increase of ROS level (p<0.05) and a decrease of phagocytic rate of haemocytes (p<0.05), which could be inhibited by KH7. The results collectively suggest that CgsAC is an important acid-base sensor in oyster and the [HCO3-]/CgsAC/cAMP signal pathway might be responsible for intracellular alkalization effects on oxidative phosphorylation and innate immunity under CO2 exposure. The changes of intracellular pH, ROS, and phagocytosis mediated by CgsAC might help us to further understand the effects of ocean acidification on marine calcifiers.
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Affiliation(s)
- Xiudan Wang
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Mengqiang Wang
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
| | - Zhihao Jia
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hao Wang
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
| | - Shuai Jiang
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
| | - Hao Chen
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Lingling Wang
- Key Laboratory of Mariculture & Stock Enhancement in North China's Sea, Ministry of Agriculture, Dalian Ocean University, Dalian 116023, China
| | - Linsheng Song
- Key Laboratory of Mariculture & Stock Enhancement in North China's Sea, Ministry of Agriculture, Dalian Ocean University, Dalian 116023, China.
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Chandrasekhar R, Alzayady KJ, Wagner LE, Yule DI. Unique Regulatory Properties of Heterotetrameric Inositol 1,4,5-Trisphosphate Receptors Revealed by Studying Concatenated Receptor Constructs. J Biol Chem 2016; 291:4846-60. [PMID: 26755721 DOI: 10.1074/jbc.m115.705301] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Indexed: 02/02/2023] Open
Abstract
The ability of inositol 1,4,5-trisphosphate receptors (IP3R) to precisely initiate and generate a diverse variety of intracellular Ca(2+) signals is in part mediated by the differential regulation of the three subtypes (R1, R2, and R3) by key functional modulators (IP3, Ca(2+), and ATP). However, the contribution of IP3R heterotetramerization to Ca(2+) signal diversity has largely been unexplored. In this report, we provide the first definitive biochemical evidence of endogenous heterotetramer formation. Additionally, we examine the contribution of individual subtypes within defined concatenated heterotetramers to the shaping of Ca(2+) signals. Under conditions where key regulators of IP3R function are optimal for Ca(2+) release, we demonstrate that individual monomers within heteromeric IP3Rs contributed equally toward generating a distinct 'blended' sensitivity to IP3 that is likely dictated by the unique IP3 binding affinity of the heteromers. However, under suboptimal conditions where [ATP] were varied, we found that one subtype dictated the ATP regulatory properties of heteromers. We show that R2 monomers within a heterotetramer were both necessary and sufficient to dictate the ATP regulatory properties. Finally, the ATP-binding site B in R2 critical for ATP regulation was mutated and rendered non-functional to address questions relating to the stoichiometry of IP3R regulation. Two intact R2 monomers were sufficient to maintain ATP regulation in R2 homotetramers. In summary, we demonstrate that heterotetrameric IP3R do not necessarily behave as the sum of the constituent subunits, and these properties likely extend the versatility of IP3-induced Ca(2+) signaling in cells expressing multiple IP3R isoforms.
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Affiliation(s)
- Rahul Chandrasekhar
- From the Department of Pharmacology and Physiology, University of Rochester, Rochester, New York 14642
| | - Kamil J Alzayady
- From the Department of Pharmacology and Physiology, University of Rochester, Rochester, New York 14642
| | - Larry E Wagner
- From the Department of Pharmacology and Physiology, University of Rochester, Rochester, New York 14642
| | - David I Yule
- From the Department of Pharmacology and Physiology, University of Rochester, Rochester, New York 14642
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18
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Activation of Phosphatidylinositol-Linked Dopamine Receptors Induces a Facilitation of Glutamate-Mediated Synaptic Transmission in the Lateral Entorhinal Cortex. PLoS One 2015; 10:e0131948. [PMID: 26133167 PMCID: PMC4489908 DOI: 10.1371/journal.pone.0131948] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Accepted: 06/08/2015] [Indexed: 11/19/2022] Open
Abstract
The lateral entorhinal cortex receives strong inputs from midbrain dopamine neurons that can modulate its sensory and mnemonic function. We have previously demonstrated that 1 µM dopamine facilitates synaptic transmission in layer II entorhinal cortex cells via activation of D1-like receptors, increased cAMP-PKA activity, and a resulting enhancement of AMPA-receptor mediated currents. The present study assessed the contribution of phosphatidylinositol (PI)-linked D1 receptors to the dopaminergic facilitation of transmission in layer II of the rat entorhinal cortex, and the involvement of phospholipase C activity and release of calcium from internal stores. Whole-cell patch-clamp recordings of glutamate-mediated evoked excitatory postsynaptic currents were obtained from pyramidal and fan cells. Activation of D1-like receptors using SKF38393, SKF83959, or 1 µM dopamine induced a reversible facilitation of EPSCs which was abolished by loading cells with either the phospholipase C inhibitor U-73122 or the Ca2+ chelator BAPTA. Neither the L-type voltage-gated Ca2+ channel blocker nifedipine, nor the L/N-type channel blocker cilnidipine, blocked the facilitation of synaptic currents. However, the facilitation was blocked by blocking Ca2+ release from internal stores via inositol 1,4,5-trisphosphate (InsP3) receptors or ryanodine receptors. Follow-up studies demonstrated that inhibiting CaMKII activity with KN-93 failed to block the facilitation, but that application of the protein kinase C inhibitor PKC(19-36) completely blocked the dopamine-induced facilitation. Overall, in addition to our previous report indicating a role for the cAMP-PKA pathway in dopamine-induced facilitation of synaptic transmission, we demonstrate here that the dopaminergic facilitation of synaptic responses in layer II entorhinal neurons also relies on a signaling cascade dependent on PI-linked D1 receptors, PLC, release of Ca2+ from internal stores, and PKC activation which is likely dependent upon both DAG and enhanced intracellular Ca2+. These signaling pathways may collaborate to enhance sensory and mnemonic function in the entorhinal cortex during tonic release of dopamine.
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19
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Vainio I, Abu Khamidakh A, Paci M, Skottman H, Juuti-Uusitalo K, Hyttinen J, Nymark S. Computational Model of Ca2+ Wave Propagation in Human Retinal Pigment Epithelial ARPE-19 Cells. PLoS One 2015; 10:e0128434. [PMID: 26070134 PMCID: PMC4466493 DOI: 10.1371/journal.pone.0128434] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Accepted: 04/27/2015] [Indexed: 12/21/2022] Open
Abstract
Objective Computational models of calcium (Ca2+) signaling have been constructed for several cell types. There are, however, no such models for retinal pigment epithelium (RPE). Our aim was to construct a Ca2+ signaling model for RPE based on our experimental data of mechanically induced Ca2+ wave in the in vitro model of RPE, the ARPE-19 monolayer. Methods We combined six essential Ca2+ signaling components into a model: stretch-sensitive Ca2+ channels (SSCCs), P2Y2 receptors, IP3 receptors, ryanodine receptors, Ca2+ pumps, and gap junctions. The cells in our epithelial model are connected to each other to enable transport of signaling molecules. Parameterization was done by tuning the above model components so that the simulated Ca2+ waves reproduced our control experimental data and data where gap junctions were blocked. Results Our model was able to explain Ca2+ signaling in ARPE-19 cells, and the basic mechanism was found to be as follows: 1) Cells near the stimulus site are likely to conduct Ca2+ through plasma membrane SSCCs and gap junctions conduct the Ca2+ and IP3 between cells further away. 2) Most likely the stimulated cell secretes ligand to the extracellular space where the ligand diffusion mediates the Ca2+ signal so that the ligand concentration decreases with distance. 3) The phosphorylation of the IP3 receptor defines the cell’s sensitivity to the extracellular ligand attenuating the Ca2+ signal in the distance. Conclusions The developed model was able to simulate an array of experimental data including drug effects. Furthermore, our simulations predict that suramin may interfere ligand binding on P2Y2 receptors or accelerate P2Y2 receptor phosphorylation, which may partially be the reason for Ca2+ wave attenuation by suramin. Being the first RPE Ca2+ signaling model created based on experimental data on ARPE-19 cell line, the model offers a platform for further modeling of native RPE functions.
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Affiliation(s)
- Iina Vainio
- Department of Electronics and Communications Engineering, Tampere University of Technology, Tampere, Finland
- Institute of Biosciences and Medical Technology, Tampere University of Technology, Tampere, Finland
- * E-mail:
| | - Amna Abu Khamidakh
- Department of Electronics and Communications Engineering, Tampere University of Technology, Tampere, Finland
- Institute of Biosciences and Medical Technology, Tampere University of Technology, Tampere, Finland
| | - Michelangelo Paci
- Department of Electronics and Communications Engineering, Tampere University of Technology, Tampere, Finland
- Institute of Biosciences and Medical Technology, Tampere University of Technology, Tampere, Finland
| | - Heli Skottman
- Institute of Biosciences and Medical Technology, University of Tampere, Tampere, Finland
| | - Kati Juuti-Uusitalo
- Institute of Biosciences and Medical Technology, University of Tampere, Tampere, Finland
| | - Jari Hyttinen
- Department of Electronics and Communications Engineering, Tampere University of Technology, Tampere, Finland
- Institute of Biosciences and Medical Technology, Tampere University of Technology, Tampere, Finland
| | - Soile Nymark
- Department of Electronics and Communications Engineering, Tampere University of Technology, Tampere, Finland
- Institute of Biosciences and Medical Technology, Tampere University of Technology, Tampere, Finland
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20
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Shah SZA, Zhao D, Khan SH, Yang L. Regulatory Mechanisms of Endoplasmic Reticulum Resident IP3 Receptors. J Mol Neurosci 2015; 56:938-948. [PMID: 25859934 DOI: 10.1007/s12031-015-0551-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Accepted: 03/23/2015] [Indexed: 11/25/2022]
Abstract
Dysregulated calcium signaling and accumulation of aberrant proteins causing endoplasmic reticulum stress are the early sign of intra-axonal pathological events in many neurodegenerative diseases, and apoptotic signaling is initiated when the stress goes beyond the maximum threshold level of endoplasmic reticulum. The fate of the cell to undergo apoptosis is controlled by Ca2(+) signaling and dynamics at the level of the endoplasmic reticulum. Endoplasmic reticulum resident inositol 1,4,5-trisphosphate receptors (IP3R) play a pivotal role in cell death signaling by mediating Ca2(+) flux from the endoplasmic reticulum into the cytosol and mitochondria. Hence, many prosurvival and prodeath signaling pathways and proteins affect Ca2(+) signaling by directly targeting IP3R channels, which can happen in an IP3R-isoform-dependent manner. Here, in this review, we summarize the regulatory mechanisms of inositol triphosphate receptors in calcium regulation and initiation of apoptosis during unfolded protein response.
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Affiliation(s)
- Syed Zahid Ali Shah
- State Key Laboratories for Agrobiotechnology, Key Lab of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China
| | - Deming Zhao
- State Key Laboratories for Agrobiotechnology, Key Lab of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China
| | - Sher Hayat Khan
- State Key Laboratories for Agrobiotechnology, Key Lab of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China
| | - Lifeng Yang
- State Key Laboratories for Agrobiotechnology, Key Lab of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, 100193, China.
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Carbonic anhydrase-8 regulates inflammatory pain by inhibiting the ITPR1-cytosolic free calcium pathway. PLoS One 2015; 10:e0118273. [PMID: 25734498 PMCID: PMC4347988 DOI: 10.1371/journal.pone.0118273] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Accepted: 01/12/2015] [Indexed: 01/01/2023] Open
Abstract
Calcium dysregulation is causally linked with various forms of neuropathology including seizure disorders, multiple sclerosis, Huntington’s disease, Alzheimer’s, spinal cerebellar ataxia (SCA) and chronic pain. Carbonic anhydrase-8 (Car8) is an allosteric inhibitor of inositol trisphosphate receptor-1 (ITPR1), which regulates intracellular calcium release fundamental to critical cellular functions including neuronal excitability, neurite outgrowth, neurotransmitter release, mitochondrial energy production and cell fate. In this report we test the hypothesis that Car8 regulation of ITPR1 and cytoplasmic free calcium release is critical to nociception and pain behaviors. We show Car8 null mutant mice (MT) exhibit mechanical allodynia and thermal hyperalgesia. Dorsal root ganglia (DRG) from MT also demonstrate increased steady-state ITPR1 phosphorylation (pITPR1) and cytoplasmic free calcium release. Overexpression of Car8 wildtype protein in MT nociceptors complements Car8 deficiency, down regulates pITPR1 and abolishes thermal and mechanical hypersensitivity. We also show that Car8 nociceptor overexpression alleviates chronic inflammatory pain. Finally, inflammation results in downregulation of DRG Car8 that is associated with increased pITPR1 expression relative to ITPR1, suggesting a possible mechanism of acute hypersensitivity. Our findings indicate Car8 regulates the ITPR1-cytosolic free calcium pathway that is critical to nociception, inflammatory pain and possibly other neuropathological states. Car8 and ITPR1 represent new therapeutic targets for chronic pain.
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22
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Song W, Jin XA. Cyclic AMP inhibits neuromuscular junction maturation mediated by intracellular Ca2+. Neurosci Lett 2015; 589:104-9. [PMID: 25596442 DOI: 10.1016/j.neulet.2015.01.025] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2014] [Revised: 01/09/2015] [Accepted: 01/12/2015] [Indexed: 11/18/2022]
Abstract
The neuromuscular junction (NMJ) is established through initial contact of motor neuron axon with a skeletal muscle cell and the subsequent synaptic maturation. Previous studies have shown that cyclic AMP (cAMP) enhanced spinal neurons' survival and growth but inhibited synaptogenesis. Here, we find that elevating intracellular cAMP level of presynaptic neurons prevented NMJs from maturation both physiologically and morphologically. Importantly, cytosolic Ca(2+) is essential for the inhibitory effects of cAMP on NMJ maturation. We show that depletion of intracellular Ca(2+) store, rather than extracellular Ca(2+), abolished the cAMP-dependent inhibition of synaptic maturation. Taken together, we demonstrate that Ca(2+) released from intracellular Ca(2+) stores regulates neurotrophic actions on NMJ maturation.
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Affiliation(s)
- Wei Song
- Peking University Health Science Center, Beijing 100191, China; Division of Life Science, Hong Kong University of Science and Technology, Hong Kong, China.
| | - Xiwan Albert Jin
- Division of Life Science, Hong Kong University of Science and Technology, Hong Kong, China.
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23
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Vervloessem T, Yule DI, Bultynck G, Parys JB. The type 2 inositol 1,4,5-trisphosphate receptor, emerging functions for an intriguing Ca²⁺-release channel. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2014; 1853:1992-2005. [PMID: 25499268 DOI: 10.1016/j.bbamcr.2014.12.006] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2014] [Revised: 12/02/2014] [Accepted: 12/03/2014] [Indexed: 12/19/2022]
Abstract
The inositol 1,4,5-trisphosphate (IP3) receptor (IP3R) type 2 (IP3R2) is an intracellular Ca²⁺-release channel located on the endoplasmic reticulum (ER). IP3R2 is characterized by a high sensitivity to both IP3 and ATP and is biphasically regulated by Ca²⁺. Furthermore, IP3R2 is modulated by various protein kinases. In addition to its regulation by protein kinase A, IP3R2 forms a complex with adenylate cyclase 6 and is directly regulated by cAMP. Finally, in the ER, IP3R2 is less mobile than the other IP3R isoforms, while its functional properties appear dominant in heterotetramers. These properties make the IP3R2 a Ca²⁺ channel with exquisite properties for setting up intracellular Ca²⁺ signals with unique characteristics. IP3R2 plays a crucial role in the function of secretory cell types (e.g. pancreatic acinar cells, hepatocytes, salivary gland, eccrine sweat gland). In cardiac myocytes, the role of IP3R2 appears more complex, because, together with IP3R1, it is needed for normal cardiogenesis, while its aberrant activity is implicated in cardiac hypertrophy and arrhythmias. Most importantly, its high sensitivity to IP3 makes IP3R2 a target for anti-apoptotic proteins (e.g. Bcl-2) in B-cell cancers. Disrupting IP3R/Bcl-2 interaction therefore leads in those cells to increased Ca²⁺ release and apoptosis. Intriguingly, IP3R2 is not only implicated in apoptosis but also in the induction of senescence, another tumour-suppressive mechanism. These results were the first to unravel the physiological and pathophysiological role of IP3R2 and we anticipate that further progress will soon be made in understanding the function of IP3R2 in various tissues and organs.
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Affiliation(s)
- Tamara Vervloessem
- KU Leuven, Laboratory of Molecular and Cellular Signalling, Department of Cellular and Molecular Medicine, Leuven, Belgium
| | - David I Yule
- University of Rochester, Department of Pharmacology and Physiology, Rochester, NY, USA
| | - Geert Bultynck
- KU Leuven, Laboratory of Molecular and Cellular Signalling, Department of Cellular and Molecular Medicine, Leuven, Belgium
| | - Jan B Parys
- KU Leuven, Laboratory of Molecular and Cellular Signalling, Department of Cellular and Molecular Medicine, Leuven, Belgium.
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Signore S, Sorrentino A, Ferreira-Martins J, Kannappan R, Shafaie M, Del Ben F, Isobe K, Arranto C, Wybieralska E, Webster A, Sanada F, Ogórek B, Zheng H, Liu X, del Monte F, D'Alessandro DA, Wunimenghe O, Michler RE, Hosoda T, Goichberg P, Leri A, Kajstura J, Anversa P, Rota M. Response to letter regarding article "Inositol 1,4,5-trisphosphate receptors and human left ventricular myocytes". Circulation 2014; 129:e510-1. [PMID: 24868002 DOI: 10.1161/circulationaha.114.009347] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Sergio Signore
- Departments of Anesthesia and Medicine and Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Andrea Sorrentino
- Departments of Anesthesia and Medicine and Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - João Ferreira-Martins
- Departments of Anesthesia and Medicine and Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Ramaswamy Kannappan
- Departments of Anesthesia and Medicine and Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Mehrdad Shafaie
- Departments of Anesthesia and Medicine and Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Fabio Del Ben
- Departments of Anesthesia and Medicine and Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Kazuya Isobe
- Departments of Anesthesia and Medicine and Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Christian Arranto
- Departments of Anesthesia and Medicine and Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Ewa Wybieralska
- Departments of Anesthesia and Medicine and Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Andrew Webster
- Departments of Anesthesia and Medicine and Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Fumihiro Sanada
- Departments of Anesthesia and Medicine and Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Barbara Ogórek
- Departments of Anesthesia and Medicine and Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Hanqiao Zheng
- Departments of Anesthesia and Medicine and Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Xiaoxia Liu
- Departments of Anesthesia and Medicine and Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Federica del Monte
- Cardiovascular Institute, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA
| | - David A D'Alessandro
- Department of Cardiovascular and Thoracic Surgery, Montefiore Medical Center, Albert Einstein College of Medicine, New York, NY
| | - Oriyanhan Wunimenghe
- Department of Cardiovascular and Thoracic Surgery, Montefiore Medical Center, Albert Einstein College of Medicine, New York, NY
| | - Robert E Michler
- Department of Cardiovascular and Thoracic Surgery, Montefiore Medical Center, Albert Einstein College of Medicine, New York, NY
| | - Toru Hosoda
- Departments of Anesthesia and Medicine and Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Polina Goichberg
- Departments of Anesthesia and Medicine and Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Annarosa Leri
- Departments of Anesthesia and Medicine and Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Jan Kajstura
- Departments of Anesthesia and Medicine and Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Piero Anversa
- Departments of Anesthesia and Medicine and Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Marcello Rota
- Departments of Anesthesia and Medicine and Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
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Potentiation of insulin secretion and improvement of glucose intolerance by combining a novel G protein-coupled receptor 40 agonist DS-1558 with glucagon-like peptide-1 receptor agonists. Eur J Pharmacol 2014; 737:194-201. [PMID: 24858371 DOI: 10.1016/j.ejphar.2014.05.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Revised: 05/14/2014] [Accepted: 05/14/2014] [Indexed: 11/21/2022]
Abstract
G protein-coupled receptor 40 (GPR40) is a Gq-coupled receptor for free fatty acids predominantly expressed in pancreatic β-cells. In recent years, GPR40 agonists have been investigated for use as novel therapeutic agents in the treatment of type 2 diabetes. We discovered a novel small molecule GPR40 agonist, (3S)-3-ethoxy-3-(4-{[(1R)-4-(trifluoromethyl)-2,3-dihydro-1H-inden-1-yl]oxy}phenyl)propanoic acid (DS-1558). The GPR40-mediated effects of DS-1558 on glucose-stimulated insulin secretion were evaluated in isolated islets from GPR40 knock-out and wild-type (littermate) mice. The GPR40-mediated effects on glucose tolerance and insulin secretion were also confirmed by an oral glucose tolerance test in these mice. Furthermore, oral administration of DS-1558 (0.03, 0.1 and 0.3mg/kg) significantly and dose-dependently improved hyperglycemia and increased insulin secretion during the oral glucose tolerance test in Zucker fatty rats, the model of insulin resistance and glucose intolerance. Next, we examined the combination effects of DS-1558 with glucagon like peptide-1 (GLP-1). DS-1558 not only increased the glucose-stimulated insulin secretion by GLP-1 but also potentiated the maximum insulinogenic effects of GLP-1 after an intravenous glucose injection in normal Sprague Dawley rats. Furthermore, the glucose lowering effects of exendin-4, a GLP-1 receptor agonist, were markedly potentiated by the DS-1558 (3mg/kg) add-on in diabetic db/db mice during an intraperitoneal glucose tolerance test. In conclusion, our results indicate that add-on GPR40 agonists to GLP-1 related agents might be a potential treatment compared to single administration of these compounds. Therefore the combinations of these agents are a novel therapeutic option for type 2 diabetes.
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Ivanova H, Vervliet T, Missiaen L, Parys JB, De Smedt H, Bultynck G. Inositol 1,4,5-trisphosphate receptor-isoform diversity in cell death and survival. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2014; 1843:2164-83. [PMID: 24642269 DOI: 10.1016/j.bbamcr.2014.03.007] [Citation(s) in RCA: 139] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Revised: 03/06/2014] [Accepted: 03/09/2014] [Indexed: 01/22/2023]
Abstract
Cell-death and -survival decisions are critically controlled by intracellular Ca(2+) homeostasis and dynamics at the level of the endoplasmic reticulum (ER). Inositol 1,4,5-trisphosphate (IP3) receptors (IP3Rs) play a pivotal role in these processes by mediating Ca(2+) flux from the ER into the cytosol and mitochondria. Hence, it is clear that many pro-survival and pro-death signaling pathways and proteins affect Ca(2+) signaling by directly targeting IP3R channels, which can happen in an IP3R-isoform-dependent manner. In this review, we will focus on how the different IP3R isoforms (IP3R1, IP3R2 and IP3R3) control cell death and survival. First, we will present an overview of the isoform-specific regulation of IP3Rs by cellular factors like IP3, Ca(2+), Ca(2+)-binding proteins, adenosine triphosphate (ATP), thiol modification, phosphorylation and interacting proteins, and of IP3R-isoform specific expression patterns. Second, we will discuss the role of the ER as a Ca(2+) store in cell death and survival and how IP3Rs and pro-survival/pro-death proteins can modulate the basal ER Ca(2+) leak. Third, we will review the regulation of the Ca(2+)-flux properties of the IP3R isoforms by the ER-resident and by the cytoplasmic proteins involved in cell death and survival as well as by redox regulation. Hence, we aim to highlight the specific roles of the various IP3R isoforms in cell-death and -survival signaling. This article is part of a Special Issue entitled: Calcium signaling in health and disease. Guest Editors: Geert Bultynck, Jacques Haiech, Claus W. Heizmann, Joachim Krebs, and Marc Moreau.
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Affiliation(s)
- Hristina Ivanova
- KU Leuven Lab. of Molecular and Cellular Signaling, Dept. of Cellular and Molecular Medicine, Campus Gasthuisberg O&N I Box 802, Herestraat 49, BE-3000 Leuven, Belgium
| | - Tim Vervliet
- KU Leuven Lab. of Molecular and Cellular Signaling, Dept. of Cellular and Molecular Medicine, Campus Gasthuisberg O&N I Box 802, Herestraat 49, BE-3000 Leuven, Belgium
| | - Ludwig Missiaen
- KU Leuven Lab. of Molecular and Cellular Signaling, Dept. of Cellular and Molecular Medicine, Campus Gasthuisberg O&N I Box 802, Herestraat 49, BE-3000 Leuven, Belgium
| | - Jan B Parys
- KU Leuven Lab. of Molecular and Cellular Signaling, Dept. of Cellular and Molecular Medicine, Campus Gasthuisberg O&N I Box 802, Herestraat 49, BE-3000 Leuven, Belgium
| | - Humbert De Smedt
- KU Leuven Lab. of Molecular and Cellular Signaling, Dept. of Cellular and Molecular Medicine, Campus Gasthuisberg O&N I Box 802, Herestraat 49, BE-3000 Leuven, Belgium.
| | - Geert Bultynck
- KU Leuven Lab. of Molecular and Cellular Signaling, Dept. of Cellular and Molecular Medicine, Campus Gasthuisberg O&N I Box 802, Herestraat 49, BE-3000 Leuven, Belgium.
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Frégeau MO, Carrier M, Guillemette G. Mechanism of dopamine D2 receptor-induced Ca(2+) release in PC-12 cells. Cell Signal 2013; 25:2871-7. [PMID: 24055909 DOI: 10.1016/j.cellsig.2013.08.021] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Accepted: 08/23/2013] [Indexed: 01/06/2023]
Abstract
Intracellular Ca(2+) levels are tightly regulated in the neuronal system. The loss of Ca(2+) homeostasis is associated with many neurological diseases and neuropsychiatric disorders such as Parkinson's, Alzheimer's, and schizophrenia. We investigated the mechanisms involved in intracellular Ca(2+) signaling in PC-12 cells. The stimulation of NGF-differentiated PC-12 cells with 3μM ATP caused an early Ca(2+) release followed by a delayed Ca(2+) release. The delayed Ca(2+) release was dependent on prior ATP priming and on dopamine secretion by PC-12 cells. Delayed Ca(2+) release was abolished in the presence of spiperone, suggesting that it is due to the activation of D2 dopamine receptors (D2R) by dopamine secreted by PC-12 cells. This was shown to be independent of PKA activation but dependent on PLC activity. An endocytosis step was required for inducing the delayed Ca(2+) release. Given the importance of calcyon in clathrin-mediated endocytosis, we verified the role of this protein in the delayed Ca(2+) release phenomenon. siRNA targeting of calcyon blocked the delayed Ca(2+) release, decreased ATP-evoked IP3R-mediated Ca(2+) release, and impaired subsequent Ca(2+) oscillations. Our results suggested that calcyon is involved in an unknown mechanism that causes a delayed IP3R-mediated Ca(2+) release in PC-12 cells. In schizophrenia, Ca(2+) dysregulation may depend on the upregulation of calcyon, which maintains elevated Ca(2+) levels as well as dopamine signaling.
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Affiliation(s)
- Marc-Olivier Frégeau
- Faculty of Medicine and Health sciences, Department of Pharmacology, Université de Sherbrooke, Sherbrooke, Québec, J1H 5N4 Canada
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28
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Li D, Jiao J, Shatos MA, Hodges RR, Dartt DA. Effect of VIP on intracellular [Ca2+], extracellular regulated kinase 1/2, and secretion in cultured rat conjunctival goblet cells. Invest Ophthalmol Vis Sci 2013; 54:2872-84. [PMID: 23518767 DOI: 10.1167/iovs.12-11264] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
PURPOSE To determine the intracellular signaling pathways that vasoactive intestinal peptide (VIP) uses to stimulate high molecular weight glycoconjugate secretion from cultured rat conjunctival goblet cells. METHODS Goblet cells from rat bulbar and forniceal conjunctiva were grown in organ culture. Presence and localization of VIP receptors (VPAC1 and 2) were determined by RT-PCR, immunofluorescence microscopy and Western blot analysis. Intracellular [Ca(2+)] ([Ca(2+)]i) was measured using fura-2. Extracellular signal-regulated kinase (ERK)-1/2 activity was determined by Western blot analysis. High molecular weight glycoconjugate secretion was measured with an enzyme-linked lectin assay on cultured goblet cells that were serum-starved for 2 hours before stimulation with VIP, VPAC1-, or VPAC2-specific agonists. Inhibitors were added 30 minutes prior to VIP. Activation of epidermal growth factor receptor (EGFR) was measured by immunoprecipitation using an antibody against pTyr followed by Western blot analysis with an antibody against EGFR. RESULTS Both VIP receptors were present in rat conjunctiva and cultured goblet cells. VIP- and VPAC-specific agonists increased [Ca(2+)]i and secretion in a concentration-dependent manner. VIP also increased ERK1/2 activity, VIP-stimulated increase in [Ca(2+)]i. Secretion, but not ERK1/2 activity, was inhibited by the protein kinase A inhibitor, H89. VIP-stimulated secretion was inhibited by siRNA for ERK2 but not by siRNA for EGFR. VIP did not increase the phosphorylation of the EGFR. CONCLUSIONS In conclusion, in cultured rat conjunctival goblet cells, VPAC1 and 2 receptors are functional. VIP stimulates a cAMP-dependent increase in [Ca(2+)]i and glycoconjugate secretion, but not ERK1/2 activation. VIP does not activate with EGFR.
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Affiliation(s)
- Dayu Li
- Schepens Eye Research Institute, Massachusetts Eye and Ear and Department of Ophthalmology, Harvard Medical School, Boston, MA 02114, USA
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29
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FK506 binding proteins: Cellular regulators of intracellular Ca2+ signalling. Eur J Pharmacol 2013; 700:181-93. [DOI: 10.1016/j.ejphar.2012.12.029] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2012] [Revised: 12/04/2012] [Accepted: 12/18/2012] [Indexed: 02/04/2023]
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30
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Fechner L, Baumann O, Walz B. Activation of the cyclic AMP pathway promotes serotonin-induced Ca2+ oscillations in salivary glands of the blowfly Calliphora vicina. Cell Calcium 2012; 53:94-101. [PMID: 23131569 DOI: 10.1016/j.ceca.2012.10.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2012] [Revised: 10/12/2012] [Accepted: 10/12/2012] [Indexed: 11/28/2022]
Abstract
Ca(2+) and cAMP signalling pathways interact in a complex manner at multiple sites. This crosstalk fine-tunes the spatiotemporal patterns of Ca(2+) and cAMP signals. In salivary glands of the blowfly Calliphora vicina fluid secretion is stimulated by serotonin (5-hydroxytryptamine, 5-HT) via activation of two different 5-HT receptors coupled to the InsP(3)/Ca(2+) (Cv5-HT(2α)) or the cAMP pathway (Cv5-HT(7)), respectively. We have shown recently in permeabilized gland cells that cAMP sensitizes InsP(3)-induced Ca(2+) release to InsP(3). Here we study the effects of the cAMP signalling pathway on 5-HT-induced oscillations in transepithelial potential (TEP) and in intracellular [Ca(2+)]. We show: (1) Blocking the activation of the cAMP pathway by cinanserin suppresses the generation of TEP and Ca(2+) oscillations, (2) application of 8-CPT-cAMP in the presence of cinanserin restores 5-HT-induced TEP and Ca(2+) oscillations, (3) 8-CPT-cAMP sensitizes the InsP(3)/Ca(2+) signalling pathway to 5-HT and the Cv5-HT(2α) receptor agonist 5-MeOT, (4) 8-CPT-cAMP induces Ca(2+) oscillations in cells loaded with subthreshold concentrations of InsP(3), (5) inhibition of protein kinase A by H-89 abolishes 5-HT-induced TEP and Ca(2+) spiking and mimics the effect of cinanserin. These results suggest that activation of the cyclic AMP pathway promotes the generation of 5-HT-induced Ca(2+) oscillations in blowfly salivary glands.
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Affiliation(s)
- Lennart Fechner
- Institute of Biochemistry and Biology, Department of Animal Physiology, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam, Germany
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Abstract
Ca2+ transfer from endoplasmic reticulum (ER) to mitochondria can trigger apoptotic pathways by inducing release of mitochondrial pro-apoptotic factors. Three different types of inositol 1,4,5-trisphosphate receptor (IP3R) serve to discharge Ca2+ from ER, but possess some peculiarities, especially in apoptosis induction. The anti-apoptotic protein Akt can phosphorylate all IP3R isoforms and protect cells from apoptosis, reducing ER Ca2+ release. However, it has not been elucidated which IP3R subtypes mediate these effects. Here, we show that Akt activation in COS7 cells, which lack of IP3R I, strongly suppresses IP3-mediated Ca2+ release and apoptosis. Conversely, in SH-SY 5Y cells, which are type III-deficient, Akt is unable to modulate ER Ca2+ flux, losing its anti-apoptotic activity. In SH-SY 5Y-expressing subtype III, Akt recovers its protective function on cell death, by reduction of Ca2+ release. Moreover, regulating Ca2+ flux to mitochondria, Akt maintains the mitochondrial integrity and delays the trigger of apoptosis, in a type III-dependent mechanism. These results demonstrate a specific activity of Akt on IP3R III, leading to diminished Ca2+ transfer to mitochondria and protection from apoptosis, suggesting an additional level of cell death regulation mediated by Akt.
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Béliveau È, Lapointe F, Guillemette G. The activation state of the inositol 1,4,5-trisphosphate receptor regulates the velocity of intracellular Ca2+ waves in bovine aortic endothelial cells. J Cell Biochem 2012; 112:3722-31. [PMID: 21815194 DOI: 10.1002/jcb.23301] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Ca(2+) is a highly versatile second messenger that plays a key role in the regulation of many cell processes. This versatility resides in the fact that different signals can be encoded spatio-temporally by varying the frequency and amplitude of the Ca(2+) response. A typical example of an organized Ca(2+) signal is a Ca(2+) wave initiated in a given area of a cell that propagates throughout the entire cell or within a specific subcellular region. In non-excitable cells, the inositol 1,4,5-trisphosphate receptor (IP(3) R) is responsible for the release of Ca(2+) from the endoplasmic reticulum. IP(3) R activity can be directly modulated in many ways, including by interacting molecules, proteins, and kinases such as PKA, PKC, and mTOR. In the present study, we used a videomicroscopic approach to measure the velocity of Ca(2+) waves in bovine aortic endothelial cells under various conditions that affect IP(3) R function. The velocity of the Ca(2+) waves increased with the intensity of the stimulus while extracellular Ca(2+) had no significant impact on wave velocity. Forskolin increased the velocity of IP(3) R-dependent Ca(2+) waves whereas PMA and rapamycin decreased the velocity. We used scatter plots and Pearson's correlation test to visualize and quantify the relationship between the Ca(2+) peak amplitude and the velocity of Ca(2+) waves. The velocity of IP(3) R-dependent Ca(2+) waves poorly correlated with the amplitude of the Ca(2+) response elicited by agonists in all the conditions evaluated, indicating that the velocity depended on the activation state of IP(3) R, which can be modulated in many ways.
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Affiliation(s)
- Èric Béliveau
- Faculty of Medicine and Health Sciences, Department of Pharmacology, Université de Sherbrooke, Sherbrooke, Quebec, J1H 5N4, Canada
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33
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Meyer D, Voigt A, Widmayer P, Borth H, Huebner S, Breit A, Marschall S, de Angelis MH, Boehm U, Meyerhof W, Gudermann T, Boekhoff I. Expression of Tas1 taste receptors in mammalian spermatozoa: functional role of Tas1r1 in regulating basal Ca²⁺ and cAMP concentrations in spermatozoa. PLoS One 2012; 7:e32354. [PMID: 22427794 PMCID: PMC3303551 DOI: 10.1371/journal.pone.0032354] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2011] [Accepted: 01/25/2012] [Indexed: 12/03/2022] Open
Abstract
BACKGROUND During their transit through the female genital tract, sperm have to recognize and discriminate numerous chemical compounds. However, our current knowledge of the molecular identity of appropriate chemosensory receptor proteins in sperm is still rudimentary. Considering that members of the Tas1r family of taste receptors are able to discriminate between a broad diversity of hydrophilic chemosensory substances, the expression of taste receptors in mammalian spermatozoa was examined. METHODOLOGY/PRINCIPAL FINDINGS The present manuscript documents that Tas1r1 and Tas1r3, which form the functional receptor for monosodium glutamate (umami) in taste buds on the tongue, are expressed in murine and human spermatozoa, where their localization is restricted to distinct segments of the flagellum and the acrosomal cap of the sperm head. Employing a Tas1r1-deficient mCherry reporter mouse strain, we found that Tas1r1 gene deletion resulted in spermatogenic abnormalities. In addition, a significant increase in spontaneous acrosomal reaction was observed in Tas1r1 null mutant sperm whereas acrosomal secretion triggered by isolated zona pellucida or the Ca²⁺ ionophore A23187 was not different from wild-type spermatozoa. Remarkably, cytosolic Ca²⁺ levels in freshly isolated Tas1r1-deficient sperm were significantly higher compared to wild-type cells. Moreover, a significantly higher basal cAMP concentration was detected in freshly isolated Tas1r1-deficient epididymal spermatozoa, whereas upon inhibition of phosphodiesterase or sperm capacitation, the amount of cAMP was not different between both genotypes. CONCLUSIONS/SIGNIFICANCE Since Ca²⁺ and cAMP control fundamental processes during the sequential process of fertilization, we propose that the identified taste receptors and coupled signaling cascades keep sperm in a chronically quiescent state until they arrive in the vicinity of the egg - either by constitutive receptor activity and/or by tonic receptor activation by gradients of diverse chemical compounds in different compartments of the female reproductive tract.
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MESH Headings
- Animals
- Blotting, Western
- Calcium/metabolism
- Cyclic AMP/metabolism
- Female
- Gene Expression
- Humans
- Luminescent Proteins/genetics
- Luminescent Proteins/metabolism
- Male
- Mice
- Mice, 129 Strain
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Mice, Knockout
- Mice, Transgenic
- Microscopy, Confocal
- Models, Biological
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Rats
- Rats, Wistar
- Receptors, G-Protein-Coupled/genetics
- Receptors, G-Protein-Coupled/metabolism
- Receptors, G-Protein-Coupled/physiology
- Reverse Transcriptase Polymerase Chain Reaction
- Sperm Head/metabolism
- Spermatozoa/metabolism
- Testis/cytology
- Testis/metabolism
- Red Fluorescent Protein
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Affiliation(s)
- Dorke Meyer
- Walther-Straub Institute of Pharmacology and
Toxicology, Ludwig-Maximilians-University, Munich, Germany
| | - Anja Voigt
- German Institute of Nutrition,
Potsdam-Rehbruecke, Germany
- Institute for Neural Signal Transduction,
Center for Molecular Neurobiology, Hamburg, Germany
| | - Patricia Widmayer
- Institute of Physiology, University of
Hohenheim, Stuttgart, Germany
| | - Heike Borth
- Walther-Straub Institute of Pharmacology and
Toxicology, Ludwig-Maximilians-University, Munich, Germany
| | - Sandra Huebner
- German Institute of Nutrition,
Potsdam-Rehbruecke, Germany
| | - Andreas Breit
- Walther-Straub Institute of Pharmacology and
Toxicology, Ludwig-Maximilians-University, Munich, Germany
| | - Susan Marschall
- Institute of Experimental Genetics,
Helmholtz-Zentrum, Munich, Germany
| | | | - Ulrich Boehm
- Institute for Neural Signal Transduction,
Center for Molecular Neurobiology, Hamburg, Germany
| | | | - Thomas Gudermann
- Walther-Straub Institute of Pharmacology and
Toxicology, Ludwig-Maximilians-University, Munich, Germany
| | - Ingrid Boekhoff
- Walther-Straub Institute of Pharmacology and
Toxicology, Ludwig-Maximilians-University, Munich, Germany
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Chaloux B, Caron AZ, Guillemette G. Protein kinase A increases the binding affinity and the Ca2+ release activity of the inositol 1,4,5-trisphosphate receptor type 3 in RINm5F cells. Biol Cell 2012; 99:379-88. [PMID: 17373911 DOI: 10.1042/bc20060121] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND INFORMATION In endocrine cells, IP(3)R (inositol 1,4,5-trisphosphate receptor), a ligand-gated Ca2+ channel, plays an important role in the control of intracellular Ca2+ concentration. There are three subtypes of IP(3)R that are distributed differentially among cell types. RINm5F cells express almost exclusively the IP(3)R-3 subtype. The purpose of the present study was to investigate the effect of PKA (protein kinase A) on the activity of IP(3)R-3 in RINm5F cells. RESULTS We show that immunoprecipitated IP(3)R-3 is a good substrate for PKA. Using a back-phosphorylation approach, we show that endogenous PKA phosphorylates IP(3)R-3 in intact RINm5F cells. [(3)H]IP(3) (inositol 1,4,5-trisphosphate) binding affinity and IP(3)-induced Ca2+ release activity were enhanced in permeabilized cells that were pre-treated with forskolin or PKA. The PKA-induced enhancement of IP(3)R-3 activity was also observed in intact RINm5F cells stimulated with carbachol and epidermal growth factor, two agonists that use different receptor types to activate phospholipase C. CONCLUSION The results of the present study reveal a converging step where the cAMP and the Ca2+ signalling systems act co-operatively in endocrine cell responses to external stimuli.
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Affiliation(s)
- Benoit Chaloux
- Department of Pharmacology, Faculty of Medicine and Health Sciences, University of Sherbrooke, Sherbrooke, Quebec, Canada
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35
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Hagenston AM, Bading H. Calcium signaling in synapse-to-nucleus communication. Cold Spring Harb Perspect Biol 2011; 3:a004564. [PMID: 21791697 DOI: 10.1101/cshperspect.a004564] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Changes in the intracellular concentration of calcium ions in neurons are involved in neurite growth, development, and remodeling, regulation of neuronal excitability, increases and decreases in the strength of synaptic connections, and the activation of survival and programmed cell death pathways. An important aspect of the signals that trigger these processes is that they are frequently initiated in the form of glutamatergic neurotransmission within dendritic trees, while their completion involves specific changes in the patterns of genes expressed within neuronal nuclei. Accordingly, two prominent aims of research concerned with calcium signaling in neurons are determination of the mechanisms governing information conveyance between synapse and nucleus, and discovery of the rules dictating translation of specific patterns of inputs into appropriate and specific transcriptional responses. In this article, we present an overview of the avenues by which glutamatergic excitation of dendrites may be communicated to the neuronal nucleus and the primary calcium-dependent signaling pathways by which synaptic activity can invoke changes in neuronal gene expression programs.
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Affiliation(s)
- Anna M Hagenston
- CellNetworks-Cluster of Excellence, Department of Neurobiology, Interdisciplinary Center for Neurosciences, University of Heidelberg, 69120 Heidelberg, Germany
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36
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37
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Inositol 1,4,5-trisphosphate receptor subtype-specific regulation of calcium oscillations. Neurochem Res 2011; 36:1175-85. [PMID: 21479917 PMCID: PMC3111726 DOI: 10.1007/s11064-011-0457-7] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/18/2011] [Indexed: 11/18/2022]
Abstract
Oscillatory fluctuations in the cytosolic concentration of free calcium ions (Ca2+) are considered a ubiquitous mechanism for controlling multiple cellular processes. Inositol 1,4,5-trisphosphate (IP3) receptors (IP3R) are intracellular Ca2+ release channels that mediate Ca2+ release from endoplasmic reticulum (ER) Ca2+ stores. The three IP3R subtypes described so far exhibit differential structural, biophysical, and biochemical properties. Subtype specific regulation of IP3R by the endogenous modulators IP3, Ca2+, protein kinases and associated proteins have been thoroughly examined. In this article we will review the contribution of each IP3R subtype in shaping cytosolic Ca2+ oscillations.
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Masuda W, Betzenhauser MJ, Yule DI. InsP3R-associated cGMP kinase substrate determines inositol 1,4,5-trisphosphate receptor susceptibility to phosphoregulation by cyclic nucleotide-dependent kinases. J Biol Chem 2010; 285:37927-38. [PMID: 20876535 DOI: 10.1074/jbc.m110.168989] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Ca(2+) release through inositol 1,4,5-trisphosphate receptors (InsP(3)R) can be modulated by numerous factors, including input from other signal transduction cascades. These events shape the spatio-temporal characteristics of the Ca(2+) signal and provide fidelity essential for the appropriate activation of effectors. In this study, we investigate the regulation of Ca(2+) release via InsP(3)R following activation of cyclic nucleotide-dependent kinases in the presence and absence of expression of a binding partner InsP(3)R-associated cGMP kinase substrate (IRAG). cGMP-dependent kinase (PKG) phosphorylation of only the S2+ InsP(3)R-1 subtype resulted in enhanced Ca(2+) release in the absence of IRAG expression. In contrast, IRAG bound to each InsP(3)R subtype, and phosphorylation of IRAG by PKG attenuated Ca(2+) release through all InsP(3)R subtypes. Surprisingly, simply the expression of IRAG attenuated phosphorylation and inhibited the enhanced Ca(2+) release through InsP(3)R-1 following cAMP-dependent protein kinase (PKA) activation. In contrast, IRAG expression did not influence the PKA-enhanced activity of the InsP(3)R-2. Phosphorylation of IRAG resulted in reduced Ca(2+) release through all InsP(3)R subtypes during concurrent activation of PKA and PKG, indicating that IRAG modulation is dominant under these conditions. These studies yield mechanistic insight into how cells with various complements of proteins integrate and prioritize signals from ubiquitous signaling pathways.
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Affiliation(s)
- Wataru Masuda
- Department of Pharmacology and Physiology, University of Rochester Medical School, Rochester, New York 14642, USA
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Betzenhauser MJ, Yule DI. Regulation of inositol 1,4,5-trisphosphate receptors by phosphorylation and adenine nucleotides. CURRENT TOPICS IN MEMBRANES 2010; 66:273-98. [PMID: 22353484 DOI: 10.1016/s1063-5823(10)66012-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Affiliation(s)
- Matthew J Betzenhauser
- Department of Physiology and Cellular Biophysics, Columbia University Medical School, New York City, New York, USA
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Abstract
Genetic and environmental factors contribute to a substantial variation in platelet function seen among normal persons. Candidate gene association studies represent a valiant effort to define the genetic component in an era where genetic tools were limited, but the single nucleotide polymorphisms identified in those studies need to be validated by more objective, comprehensive approaches, such as genome-wide association studies (GWASs) of quantitative functional traits in much larger cohorts of more carefully selected normal subjects. During the past year, platelet count and mean platelet volume, which indirectly affect platelet function, were the subjects of GWAS. The majority of the GWAS signals were located to noncoding regions, a consistent outcome of all GWAS to date, suggesting a major role for mechanisms that alter phenotype at the level of transcription or posttranscriptional modifications. Of 15 quantitative trait loci associated with mean platelet volume and platelet count, one located at 12q24 is also a risk locus for coronary artery disease. In most cases, the effect sizes of individual quantitative trait loci are admittedly small, but the results of these studies have led to new insight into regulators of hematopoiesis and megakaryopoiesis that would otherwise be unapparent and difficult to define.
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41
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Undieh AS. Pharmacology of signaling induced by dopamine D(1)-like receptor activation. Pharmacol Ther 2010; 128:37-60. [PMID: 20547182 DOI: 10.1016/j.pharmthera.2010.05.003] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2010] [Accepted: 05/19/2010] [Indexed: 12/30/2022]
Abstract
Dopamine D(1)-like receptors consisting of D(1) and D(5) subtypes are intimately implicated in dopaminergic regulation of fundamental neurophysiologic processes such as mood, motivation, cognitive function, and motor activity. Upon stimulation, D(1)-like receptors initiate signal transduction cascades that are mediated through adenylyl cyclase or phosphoinositide metabolism, with subsequent enhancement of multiple downstream kinase cascades. The latter actions propagate and further amplify the receptor signals, thus predisposing D(1)-like receptors to multifaceted interactions with various other mediators and receptor systems. The adenylyl cyclase response to dopamine or selective D(1)-like receptor agonists is reliably associated with the D(1) subtype, while emerging evidence indicates that the phosphoinositide responses in native brain tissues may be preferentially mediated through stimulation of the D(5) receptor. Besides classic coupling of each receptor subtype to specific G proteins, additional biophysical models are advanced in attempts to account for differential subcellular distribution, heteromolecular oligomerization, and activity-dependent selectivity of the receptors. It is expected that significant advances in understanding of dopamine neurobiology will emerge from current and anticipated studies directed at uncovering the molecular mechanisms of D(5) coupling to phosphoinositide signaling, the structural features that might enhance pharmacological selectivity for D(5) versus D(1) subtypes, the mechanism by which dopamine may modulate phosphoinositide synthesis, the contributions of the various responsive signal mediators to D(1) or D(5) interactions with D(2)-like receptors, and the spectrum of dopaminergic functions that may be attributed to each receptor subtype and signaling pathway.
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Affiliation(s)
- Ashiwel S Undieh
- Laboratory of Integrative Neuropharmacology, Department of Pharmaceutical Sciences, Thomas Jefferson University School of Pharmacy, 130 South 9th Street, Suite 1510, Philadelphia, PA 19107, USA.
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Yule DI, Betzenhauser MJ, Joseph SK. Linking structure to function: Recent lessons from inositol 1,4,5-trisphosphate receptor mutagenesis. Cell Calcium 2010; 47:469-79. [PMID: 20510450 DOI: 10.1016/j.ceca.2010.04.005] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2010] [Revised: 04/21/2010] [Accepted: 04/22/2010] [Indexed: 12/12/2022]
Abstract
Great insight has been gained into the structure and function of the inositol 1,4,5 trisphosphate receptor (InsP(3)R) by studies employing mutagenesis of the cDNA encoding the receptor. Notably, early studies using this approach defined the key constituents required for InsP(3) binding in the N-terminus and the membrane spanning regions in the C-terminal domain responsible for channel formation, targeting and function. In this article we evaluate recent studies which have used a similar approach to investigate key residues underlying the in vivo modulation by select regulatory factors. In addition, we review studies defining the structural requirements in the channel domain which comprise the conduction pathway and are suggested to be involved in the gating of the channel.
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Affiliation(s)
- David I Yule
- Department of Pharmacology and Physiology, University of Rochester, NY, United States.
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Tovey SC, Dedos SG, Rahman T, Taylor EJA, Pantazaka E, Taylor CW. Regulation of inositol 1,4,5-trisphosphate receptors by cAMP independent of cAMP-dependent protein kinase. J Biol Chem 2010; 285:12979-89. [PMID: 20189985 PMCID: PMC2857138 DOI: 10.1074/jbc.m109.096016] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2009] [Revised: 02/11/2010] [Indexed: 12/02/2022] Open
Abstract
In HEK cells stably expressing type 1 receptors for parathyroid hormone (PTH), PTH causes a sensitization of inositol 1,4,5-trisphosphate receptors (IP(3)R) to IP(3) that is entirely mediated by cAMP and requires cAMP to pass directly from type 6 adenylyl cyclase (AC6) to IP(3)R2. Using DT40 cells expressing single subtypes of mammalian IP(3)R, we demonstrate that high concentrations of cAMP similarly sensitize all IP(3)R isoforms to IP(3) by a mechanism that does not require cAMP-dependent protein kinase (PKA). IP(3) binding to IP(3)R2 is unaffected by cAMP, and sensitization is not mediated by the site through which ATP potentiates responses to IP(3). In single channel recordings from excised nuclear patches of cells expressing IP(3)R2, cAMP alone had no effect, but it increased the open probability of IP(3)R2 activated by a submaximal concentration of IP(3) alone or in combination with a maximally effective concentration of ATP. These results establish that cAMP itself increases the sensitivity of all IP(3)R subtypes to IP(3). For IP(3)R2, this sensitization results from cAMP binding to a novel site that increases the efficacy of IP(3). Using stably expressed short hairpin RNA to reduce expression of the G-protein, G alpha(s), we demonstrate that attenuation of AC activity by loss of G alpha(s) more substantially reduces sensitization of IP(3)R by PTH than does comparable direct inhibition of AC. This suggests that G alpha(s) may also specifically associate with each AC x IP(3)R complex. We conclude that all three subtypes of IP(3)R are regulated by cAMP independent of PKA. In HEK cells, where IP(3)R2 selectively associates with AC6, G alpha(s) also associates with the AC x IP(3)R signaling junction.
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MESH Headings
- Adenylyl Cyclases/genetics
- Adenylyl Cyclases/metabolism
- Animals
- Cell Line
- Cyclic AMP/genetics
- Cyclic AMP/metabolism
- Cyclic AMP-Dependent Protein Kinases/genetics
- Cyclic AMP-Dependent Protein Kinases/metabolism
- GTP-Binding Protein alpha Subunits/genetics
- GTP-Binding Protein alpha Subunits/metabolism
- Humans
- Inositol 1,4,5-Trisphosphate/genetics
- Inositol 1,4,5-Trisphosphate/metabolism
- Inositol 1,4,5-Trisphosphate Receptors/genetics
- Inositol 1,4,5-Trisphosphate Receptors/metabolism
- Protein Isoforms/genetics
- Protein Isoforms/metabolism
- Rats
- Receptor, Parathyroid Hormone, Type 1/genetics
- Receptor, Parathyroid Hormone, Type 1/metabolism
- Signal Transduction/physiology
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Affiliation(s)
- Stephen C. Tovey
- From the Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, United Kingdom
| | - Skarlatos G. Dedos
- From the Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, United Kingdom
| | - Taufiq Rahman
- From the Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, United Kingdom
| | - Emily J. A. Taylor
- From the Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, United Kingdom
| | - Evangelia Pantazaka
- From the Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, United Kingdom
| | - Colin W. Taylor
- From the Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, United Kingdom
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Control of intracellular calcium signaling as a neuroprotective strategy. Molecules 2010; 15:1168-95. [PMID: 20335972 PMCID: PMC2847496 DOI: 10.3390/molecules15031168] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2009] [Revised: 02/05/2010] [Accepted: 03/02/2010] [Indexed: 12/13/2022] Open
Abstract
Both acute and chronic degenerative diseases of the nervous system reduce the viability and function of neurons through changes in intracellular calcium signaling. In particular, pathological increases in the intracellular calcium concentration promote such pathogenesis. Disease involvement of numerous regulators of intracellular calcium signaling located on the plasma membrane and intracellular organelles has been documented. Diverse groups of chemical compounds targeting ion channels, G-protein coupled receptors, pumps and enzymes have been identified as potential neuroprotectants. The present review summarizes the discovery, mechanisms and biological activity of neuroprotective molecules targeting proteins that control intracellular calcium signaling to preserve or restore structure and function of the nervous system. Disease relevance, clinical applications and new technologies for the identification of such molecules are being discussed.
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45
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Betzenhauser MJ, Fike JL, Wagner LE, Yule DI. Protein kinase A increases type-2 inositol 1,4,5-trisphosphate receptor activity by phosphorylation of serine 937. J Biol Chem 2009; 284:25116-25. [PMID: 19608738 DOI: 10.1074/jbc.m109.010132] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Protein kinase A (PKA) phosphorylation of inositol 1,4,5-trisphosphate receptors (InsP(3)Rs) represents a mechanism for shaping intracellular Ca(2+) signals following a concomitant elevation in cAMP. Activation of PKA results in enhanced Ca(2+) release in cells that express predominantly InsP(3)R2. PKA is known to phosphorylate InsP(3)R2, but the molecular determinants of this effect are not known. We have expressed mouse InsP(3)R2 in DT40-3KO cells that are devoid of endogenous InsP(3)R and examined the effects of PKA phosphorylation on this isoform in unambiguous isolation. Activation of PKA increased Ca(2+) signals and augmented the single channel open probability of InsP(3)R2. A PKA phosphorylation site unique to the InsP(3)R2 was identified at Ser(937). The enhancing effects of PKA activation on this isoform required the phosphorylation of Ser(937), since replacing this residue with alanine eliminated the positive effects of PKA activation. These results provide a mechanism responsible for the enhanced Ca(2+) signaling following PKA activation in cells that express predominantly InsP(3)R2.
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Affiliation(s)
- Matthew J Betzenhauser
- Department of Pharmacology and Physiology, School of Medicine and Dentistry, University of Rochester Medical Center, Rochester, New York 14642, USA
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46
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A novel variant on chromosome 7q22.3 associated with mean platelet volume, counts, and function. Blood 2009; 113:3831-7. [PMID: 19221038 DOI: 10.1182/blood-2008-10-184234] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Mean platelet volume (MPV) and platelet count (PLT) are highly heritable and tightly regulated traits. We performed a genome-wide association study for MPV and identified one SNP, rs342293, as having highly significant and reproducible association with MPV (per-G allele effect 0.016 +/- 0.001 log fL; P < 1.08 x 10(-24)) and PLT (per-G effect -4.55 +/- 0.80 10(9)/L; P < 7.19 x 10(-8)) in 8586 healthy subjects. Whole-genome expression analysis in the 1-MB region showed a significant association with platelet transcript levels for PIK3CG (n = 35; P = .047). The G allele at rs342293 was also associated with decreased binding of annexin V to platelets activated with collagen-related peptide (n = 84; P = .003). The region 7q22.3 identifies the first QTL influencing platelet volume, counts, and function in healthy subjects. Notably, the association signal maps to a chromosome region implicated in myeloid malignancies, indicating this site as an important regulatory site for hematopoiesis. The identification of loci regulating MPV by this and other studies will increase our insight in the processes of megakaryopoiesis and proplatelet formation, and it may aid the identification of genes that are somatically mutated in essential thrombocytosis.
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47
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Vanderheyden V, Devogelaere B, Missiaen L, De Smedt H, Bultynck G, Parys JB. Regulation of inositol 1,4,5-trisphosphate-induced Ca2+ release by reversible phosphorylation and dephosphorylation. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2008; 1793:959-70. [PMID: 19133301 DOI: 10.1016/j.bbamcr.2008.12.003] [Citation(s) in RCA: 151] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2008] [Revised: 11/27/2008] [Accepted: 12/03/2008] [Indexed: 12/12/2022]
Abstract
The inositol 1,4,5-trisphosphate (IP3) receptor (IP3R) is a universal intracellular Ca2+-release channel. It is activated after cell stimulation and plays a crucial role in the initiation and propagation of the complex spatio-temporal Ca2+ signals that control cellular processes as different as fertilization, cell division, cell migration, differentiation, metabolism, muscle contraction, secretion, neuronal processing, and ultimately cell death. To achieve these various functions, often in a single cell, exquisite control of the Ca2+ release is needed. This review aims to highlight how protein kinases and protein phosphatases can interact with the IP3R or with associated proteins and so provide a large potential for fine tuning the Ca2+-release activity and for creating efficient Ca2+ signals in subcellular microdomains.
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Affiliation(s)
- Veerle Vanderheyden
- Laboratory of Molecular and Cellular Signalling, Department Molecular and Cellular Biology, Campus Gasthuisberg O/N1-K. U. Leuven, Herestraat 49-Bus 802, B-3000 Leuven, Belgium
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48
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Hwang JY, Duncan RS, Madry C, Singh M, Koulen P. Progesterone potentiates calcium release through IP3 receptors by an Akt-mediated mechanism in hippocampal neurons. Cell Calcium 2008; 45:233-42. [PMID: 19081133 DOI: 10.1016/j.ceca.2008.10.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2008] [Revised: 08/29/2008] [Accepted: 10/26/2008] [Indexed: 12/19/2022]
Abstract
Progesterone (P4) is a steroid hormone that plays multiple roles in the central nervous system (CNS) including promoting neuroprotection. However, the precise mechanisms involved in its neuroprotective effects are still unknown. Given that the regulation of the intracellular calcium (Ca(2+)) concentration is critical for cell survival, we determined if inositol 1, 4, 5-trisphosphate receptors (IP(3)Rs) are relevant targets of P4. Using primary hippocampal neurons, we tested the hypothesis that P4 controls the gain of IP3R-mediated intracellular Ca(2+) signaling in neurons and characterized the subcellular distribution and phosphorylation of potential signaling intermediates involved in P4s actions. Our results reveal that P4 treatment altered the intensity and distribution of IP3R immunoreactivity and induced the nuclear translocation of phosphorylated Akt. Further, P4 potentiated IP(3)R-mediated intracellular Ca(2+) responses. These results suggest a potential involvement of P4 in particular and of steroid hormone signaling pathways in general in the control of intracellular Ca(2+) signaling and its related functions.
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Affiliation(s)
- Ji-yeon Hwang
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center at Fort Worth, 3500 Camp Bowie Blvd., Fort Worth, TX 76107-2699, USA
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49
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Studying isoform-specific inositol 1,4,5-trisphosphate receptor function and regulation. Methods 2008; 46:177-82. [PMID: 18929664 DOI: 10.1016/j.ymeth.2008.09.014] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2008] [Accepted: 09/12/2008] [Indexed: 11/23/2022] Open
Abstract
Inositol 1,4,5-trisphosphate receptors (InsP3R) are a family of ubiquitously expressed intracellular Ca2+ channels. Isoform-specific properties of the three family members may play a prominent role in defining the rich diversity of the spatial and temporal characteristics of intracellular Ca2+ signals. Studying the properties of the particular family members is complicated because individual receptor isoforms are typically never expressed in isolation. In this article, we discuss strategies for studying Ca2+ release through individual InsP3R family members with particular reference to methods applicable following expression of recombinant InsP3R and mutant constructs in the DT40-3KO cell line, an unambiguously null InsP3R expression system.
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50
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Park HS, Betzenhauser MJ, Won JH, Chen J, Yule DI. The type 2 inositol (1,4,5)-trisphosphate (InsP3) receptor determines the sensitivity of InsP3-induced Ca2+ release to ATP in pancreatic acinar cells. J Biol Chem 2008; 283:26081-8. [PMID: 18658132 DOI: 10.1074/jbc.m804184200] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Calcium release through inositol (1,4,5)-trisphosphate receptors (InsP(3)R) is the primary signal driving digestive enzyme and fluid secretion from pancreatic acinar cells. The type 2 (InsP(3)R2) and type 3 (InsP(3)R3) InsP(3)R are the predominant isoforms expressed in acinar cells and are required for proper exocrine gland function. Both InsP(3)R2 and InsP(3)R3 are positively regulated by cytosolic ATP, but InsP(3)R2 is 10-fold more sensitive than InsP(3)R3 to this form of modulation. In this study, we examined the role of InsP(3)R2 in setting the sensitivity of InsP(3)-induced Ca(2+) release (IICR) to ATP in pancreatic acinar cells. IICR was measured in permeabilized acinar cells from wild-type (WT) and InsP(3)R2 knock-out (KO) mice. ATP augmented IICR from WT pancreatic cells with an EC(50) of 38 microm. However, the EC(50) was 10-fold higher in acinar cells isolated from InsP(3)R2-KO mice, indicating a role for InsP(3)R2 in setting the sensitivity of IICR to ATP. Consistent with this idea, heterologous expression of InsP(3)R2 in RinM5F cells, which natively express predominately InsP(3)R3, increased the sensitivity of IICR to ATP. Depletion of ATP attenuated agonist-induced Ca(2+) signaling in WT pancreatic acinar cells. This effect was more profound in acinar cells prepared from InsP(3)R2-KO mice. These data suggest that the sensitivity of IICR to ATP depletion is regulated by the particular complement of InsP(3)R expressed in an individual cell. The effects of metabolic stress on intracellular Ca(2+) signals can therefore be determined by the relative amount of InsP(3)R2 expressed in cells.
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Affiliation(s)
- Hyung Seo Park
- Department of Pharmacology and Physiology, School of Medicine and Dentistry, University of Rochester Medical Center, Rochester, New York 14642, USA
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