1
|
Wu L, Chen J. Type 3 IP3 receptor: Its structure, functions, and related disease implications. Channels (Austin) 2023; 17:2267416. [PMID: 37818548 PMCID: PMC10569359 DOI: 10.1080/19336950.2023.2267416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2023] [Accepted: 10/02/2023] [Indexed: 10/12/2023] Open
Abstract
Cell-fate decisions depend on the precise and strict regulation of multiple signaling molecules and transcription factors, especially intracellular Ca2+ homeostasis and dynamics. Type 3 inositol 1,4,5-triphosphate receptor (IP3R3) is an a tetrameric channel that can mediate the release of Ca2+ from the endoplasmic reticulum (ER) in response to extracellular stimuli. The gating of IP3R3 is regulated not only by ligands but also by other interacting proteins. To date, extensive research conducted on the basic structure of IP3R3, as well as its regulation by ligands and interacting proteins, has provided novel perspectives on its biological functions and pathogenic mechanisms. This review aims to discuss recent advancements in the study of IP3R3 and provides a comprehensive overview of the relevant literature pertaining to its structure, biological functions, and pathogenic mechanisms.
Collapse
Affiliation(s)
- Lvying Wu
- Institute of Clinical Medicine, The Second Affiliated Hospital of Hainan Medical University, Haikou, China
| | - Jin Chen
- Institute of Clinical Medicine, The Second Affiliated Hospital of Hainan Medical University, Haikou, China
| |
Collapse
|
2
|
Smith HA, Thillaiappan NB, Rossi AM. IP 3 receptors: An "elementary" journey from structure to signals. Cell Calcium 2023; 113:102761. [PMID: 37271052 DOI: 10.1016/j.ceca.2023.102761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 05/15/2023] [Accepted: 05/18/2023] [Indexed: 06/06/2023]
Abstract
Inositol 1,4,5-trisphosphate receptors (IP3Rs) are large tetrameric channels which sit mostly in the membrane of the endoplasmic reticulum (ER) and mediate Ca2+ release from intracellular stores in response to extracellular stimuli in almost all cells. Dual regulation of IP3Rs by IP3 and Ca2+ itself, upstream "licensing", and the arrangement of IP3Rs into small clusters in the ER membrane, allow IP3Rs to generate spatially and temporally diverse Ca2+ signals. The characteristic biphasic regulation of IP3Rs by cytosolic Ca2+ concentration underpins regenerative Ca2+ signals by Ca2+-induced Ca2+-release, while also preventing uncontrolled explosive Ca2+ release. In this way, cells can harness a simple ion such as Ca2+ as a near-universal intracellular messenger to regulate diverse cellular functions, including those with conflicting outcomes such as cell survival and cell death. High-resolution structures of the IP3R bound to IP3 and Ca2+ in different combinations have together started to unravel the workings of this giant channel. Here we discuss, in the context of recently published structures, how the tight regulation of IP3Rs and their cellular geography lead to generation of "elementary" local Ca2+ signals known as Ca2+ "puffs", which form the fundamental bottleneck through which all IP3-mediated cytosolic Ca2+ signals must first pass.
Collapse
Affiliation(s)
- Holly A Smith
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, United Kingdom
| | | | - Ana M Rossi
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, United Kingdom.
| |
Collapse
|
3
|
Atakpa-Adaji P, Ivanova A. IP 3R at ER-Mitochondrial Contact Sites: Beyond the IP 3R-GRP75-VDAC1 Ca 2+ Funnel. CONTACT (THOUSAND OAKS (VENTURA COUNTY, CALIF.)) 2023; 6:25152564231181020. [PMID: 37426575 PMCID: PMC10328019 DOI: 10.1177/25152564231181020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 05/23/2023] [Indexed: 07/11/2023]
Abstract
Membrane contact sites (MCS) circumvent the topological constraints of functional coupling between different membrane-bound organelles by providing a means of communication and exchange of materials. One of the most characterised contact sites in the cell is that between the endoplasmic reticulum and the mitochondrial (ERMCS) whose function is to couple cellular Ca2+ homeostasis and mitochondrial function. Inositol 1,4,5-trisphosphate receptors (IP3Rs) on the ER, glucose-regulated protein 75 (GRP 75) and voltage-dependent anion channel 1 (VDAC1) on the outer mitochondrial membrane are the canonical component of the Ca2+ transfer unit at ERMCS. These are often reported to form a Ca2+ funnel that fuels the mitochondrial low-affinity Ca2+ uptake system. We assess the available evidence on the IP3R subtype selectivity at the ERMCS and consider if IP3Rs have other roles at the ERMCS beyond providing Ca2+. Growing evidence suggests that all three IP3R subtypes can localise and regulate Ca2+ signalling at ERMCS. Furthermore, IP3Rs may be structurally important for assembly of the ERMCS in addition to their role in providing Ca2+ at these sites. Evidence that various binding partners regulate the assembly and Ca2+ transfer at ERMCS populated by IP3R-GRP75-VDAC1, suggesting that cells have evolved mechanisms that stabilise these junctions forming a Ca2+ microdomain that is required to fuel mitochondrial Ca2+ uptake.
Collapse
Affiliation(s)
- Peace Atakpa-Adaji
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1PD, UK
| | - Adelina Ivanova
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1PD, UK
| |
Collapse
|
4
|
Means RE, Katz SG. Balancing life and death: BCL-2 family members at diverse ER-mitochondrial contact sites. FEBS J 2022; 289:7075-7112. [PMID: 34668625 DOI: 10.1111/febs.16241] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 10/11/2021] [Accepted: 10/19/2021] [Indexed: 01/13/2023]
Abstract
The outer mitochondrial membrane is a busy place. One essential activity for cellular survival is the regulation of membrane integrity by the BCL-2 family of proteins. Another critical facet of the outer mitochondrial membrane is its close approximation with the endoplasmic reticulum. These mitochondrial-associated membranes (MAMs) occupy a significant fraction of the mitochondrial surface and serve as key signaling hubs for multiple cellular processes. Each of these pathways may be considered as forming their own specialized MAM subtype. Interestingly, like membrane permeabilization, most of these pathways play critical roles in regulating cellular survival and death. Recently, the pro-apoptotic BCL-2 family member BOK has been found within MAMs where it plays important roles in their structure and function. This has led to a greater appreciation that multiple BCL-2 family proteins, which are known to participate in numerous functions throughout the cell, also have roles within MAMs. In this review, we evaluate several MAM subsets, their role in cellular homeostasis, and the contribution of BCL-2 family members to their functions.
Collapse
Affiliation(s)
- Robert E Means
- Department of Pathology, Yale University School of Medicine, New Haven, CT, USA
| | - Samuel G Katz
- Department of Pathology, Yale University School of Medicine, New Haven, CT, USA
| |
Collapse
|
5
|
Gao J, Gao A, Zhou H, Chen L. The role of metal ions in the Golgi apparatus. Cell Biol Int 2022; 46:1309-1319. [PMID: 35830695 DOI: 10.1002/cbin.11848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2022] [Revised: 05/19/2022] [Accepted: 05/28/2022] [Indexed: 11/09/2022]
Abstract
The Golgi apparatus is a membrane-bound organelle that functions as a central role in the secretory pathway. Since the discovery of the Golgi apparatus, its structure and function have attracted ever-increasing attention from researchers. Recently, it has been demonstrated that metal ions are necessary for the Golgi apparatus to maintain its proper structure and functions. Given that metal ions play an important role in various biological processes, their abnormal homeostasis is related to many diseases. Therefore, in this paper, we reviewed the uptake and release mechanisms of the Golgi apparatus Ca2+ , Cu, and Zn2+ . Furthermore, we describe the diseases associated with Golgi apparatus Ca2+ , Cu, and Zn2+ imbalance.
Collapse
Affiliation(s)
- Jiayin Gao
- Institute of Pharmacy and Pharmacology, Learning Key Laboratory for Pharmacoproteomics, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China
| | - Anbo Gao
- Institute of Pharmacy and Pharmacology, Learning Key Laboratory for Pharmacoproteomics, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China
| | - Hong Zhou
- Department of Radiology of the First Affiliated Hospital of University of South China, Hengyang, China
| | - Linxi Chen
- Institute of Pharmacy and Pharmacology, Learning Key Laboratory for Pharmacoproteomics, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, China
| |
Collapse
|
6
|
Preparation and Characterization of Calcium-Incorporated Rosa roxburghii Tratt and Its Efficacy on Bone Mineral Density in Rats. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2022; 2022:5122396. [PMID: 35497912 PMCID: PMC9045994 DOI: 10.1155/2022/5122396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 03/16/2022] [Indexed: 11/25/2022]
Abstract
The deficiency of traditional calcium preparation will gradually be replaced by the new type of calcium preparation. Rosa roxburghii fruit (R. roxburghii) is popular for its rich nutrients and functional ingredients. The fermentation broth of R. roxburghii, involving amino acids, flavonoids, triterpenes, polysaccharides, and other compounds, is favorable for calcium chelation. Thus, this study fabricated calcium-incorporated R. roxburghii (FECa) and further illustrated its efficacy on bone mineral density (BMD) in rats. The calcium holding capacity of FECa was identified and confirmed using AAS. Ion complexation of FECa was characterized using 1H-NMR, UV, SEM and EDS, and FTIR. The calcium contents of femurs were increased by 36%, and the bone trabeculae of femurs were significantly increased. Net calcium balance was enhanced to further improve BMD by oral administration of FECa. The above results indicate that FECa can be a potential and efficient calcium supplementation agent.
Collapse
|
7
|
Jackson WF. Calcium-Dependent Ion Channels and the Regulation of Arteriolar Myogenic Tone. Front Physiol 2021; 12:770450. [PMID: 34819877 PMCID: PMC8607693 DOI: 10.3389/fphys.2021.770450] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Accepted: 10/11/2021] [Indexed: 11/25/2022] Open
Abstract
Arterioles in the peripheral microcirculation regulate blood flow to and within tissues and organs, control capillary blood pressure and microvascular fluid exchange, govern peripheral vascular resistance, and contribute to the regulation of blood pressure. These important microvessels display pressure-dependent myogenic tone, the steady state level of contractile activity of vascular smooth muscle cells (VSMCs) that sets resting arteriolar internal diameter such that arterioles can both dilate and constrict to meet the blood flow and pressure needs of the tissues and organs that they perfuse. This perspective will focus on the Ca2+-dependent ion channels in the plasma and endoplasmic reticulum membranes of arteriolar VSMCs and endothelial cells (ECs) that regulate arteriolar tone. In VSMCs, Ca2+-dependent negative feedback regulation of myogenic tone is mediated by Ca2+-activated K+ (BKCa) channels and also Ca2+-dependent inactivation of voltage-gated Ca2+ channels (VGCC). Transient receptor potential subfamily M, member 4 channels (TRPM4); Ca2+-activated Cl− channels (CaCCs; TMEM16A/ANO1), Ca2+-dependent inhibition of voltage-gated K+ (KV) and ATP-sensitive K+ (KATP) channels; and Ca2+-induced-Ca2+ release through inositol 1,4,5-trisphosphate receptors (IP3Rs) participate in Ca2+-dependent positive-feedback regulation of myogenic tone. Calcium release from VSMC ryanodine receptors (RyRs) provide negative-feedback through Ca2+-spark-mediated control of BKCa channel activity, or positive-feedback regulation in cooperation with IP3Rs or CaCCs. In some arterioles, VSMC RyRs are silent. In ECs, transient receptor potential vanilloid subfamily, member 4 (TRPV4) channels produce Ca2+ sparklets that activate IP3Rs and intermediate and small conductance Ca2+ activated K+ (IKCa and sKCa) channels causing membrane hyperpolarization that is conducted to overlying VSMCs producing endothelium-dependent hyperpolarization and vasodilation. Endothelial IP3Rs produce Ca2+ pulsars, Ca2+ wavelets, Ca2+ waves and increased global Ca2+ levels activating EC sKCa and IKCa channels and causing Ca2+-dependent production of endothelial vasodilator autacoids such as NO, prostaglandin I2 and epoxides of arachidonic acid that mediate negative-feedback regulation of myogenic tone. Thus, Ca2+-dependent ion channels importantly contribute to many aspects of the regulation of myogenic tone in arterioles in the microcirculation.
Collapse
Affiliation(s)
- William F Jackson
- Department of Pharmacology and Toxicology, College of Osteopathic Medicine, Michigan State University, East Lansing, MI, United States
| |
Collapse
|
8
|
Fomina AF. Neglected wardens: T lymphocyte ryanodine receptors. J Physiol 2021; 599:4415-4426. [PMID: 34411300 DOI: 10.1113/jp281722] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Accepted: 06/22/2021] [Indexed: 12/14/2022] Open
Abstract
Ryanodine receptors (RyRs) are intracellular Ca2+ release channels ubiquitously expressed in various cell types. RyRs were extensively studied in striated muscle cells due to their crucial role in muscle contraction. In contrast, the role of RyRs in Ca2+ signalling and functions in non-excitable cells, such as T lymphocytes, remains poorly understood. Expression of different isoforms of RyRs was shown in primary T cells and T cell lines. In T cells, RyRs co-localize with the plasmalemmal store-operated Ca2+ channels of the Orai family and endoplasmic reticulum Ca2+ sensing Stim family proteins and are activated by store-operated Ca2+ entry and pyridine nucleotide metabolites, the intracellular second messengers generated upon stimulation of T cell receptors. Experimental data indicate that together with d-myo-inositol 1,4,5-trisphosphate receptors, RyRs regulate intercellular Ca2+ dynamics by controlling Ca2+ concentration within the lumen of the endoplasmic reticulum and, consequently, store-operated Ca2+ entry. Gain-of-function mutations, genetic deletion or pharmacological inhibition of RyRs alters T cell Ca2+ signalling and effector functions. The picture emerging from the collective data shows that RyRs are the essential regulators of T cell Ca2+ signalling and can be potentially used as molecular targets for immunomodulation or T cell-based diagnostics of the disorders associated with RyRs dysregulation.
Collapse
Affiliation(s)
- Alla F Fomina
- Department of Physiology and Membrane Biology, University of California, Davis, CA, USA
| |
Collapse
|
9
|
Ahumada-Castro U, Bustos G, Silva-Pavez E, Puebla-Huerta A, Lovy A, Cárdenas C. In the Right Place at the Right Time: Regulation of Cell Metabolism by IP3R-Mediated Inter-Organelle Ca 2+ Fluxes. Front Cell Dev Biol 2021; 9:629522. [PMID: 33738285 PMCID: PMC7960657 DOI: 10.3389/fcell.2021.629522] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Accepted: 01/19/2021] [Indexed: 12/18/2022] Open
Abstract
In the last few years, metabolism has been shown to be controlled by cross-organelle communication. The relationship between the endoplasmic reticulum and mitochondria/lysosomes is the most studied; here, inositol 1,4,5-triphosphate (IP3) receptor (IP3R)-mediated calcium (Ca2+) release plays a central role. Recent evidence suggests that IP3R isoforms participate in synthesis and degradation pathways. This minireview will summarize the current findings in this area, emphasizing the critical role of Ca2+ communication on organelle function as well as catabolism and anabolism, particularly in cancer.
Collapse
Affiliation(s)
- Ulises Ahumada-Castro
- Geroscience Center for Brain Health and Metabolism, Center for Integrative Biology, Faculty of Sciences, Universidad Mayor, Santiago, Chile
| | - Galdo Bustos
- Geroscience Center for Brain Health and Metabolism, Center for Integrative Biology, Faculty of Sciences, Universidad Mayor, Santiago, Chile
| | - Eduardo Silva-Pavez
- Geroscience Center for Brain Health and Metabolism, Center for Integrative Biology, Faculty of Sciences, Universidad Mayor, Santiago, Chile
| | - Andrea Puebla-Huerta
- Geroscience Center for Brain Health and Metabolism, Center for Integrative Biology, Faculty of Sciences, Universidad Mayor, Santiago, Chile
| | - Alenka Lovy
- Geroscience Center for Brain Health and Metabolism, Center for Integrative Biology, Faculty of Sciences, Universidad Mayor, Santiago, Chile.,Department of Neuroscience, Center for Neuroscience Research, Tufts University School of Medicine, Boston, MA, United States
| | - César Cárdenas
- Geroscience Center for Brain Health and Metabolism, Center for Integrative Biology, Faculty of Sciences, Universidad Mayor, Santiago, Chile.,Buck Institute for Research on Aging, Novato, CA, United States.,Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, CA, United States
| |
Collapse
|
10
|
IP3R Channels in Male Reproduction. Int J Mol Sci 2020; 21:ijms21239179. [PMID: 33276427 PMCID: PMC7730405 DOI: 10.3390/ijms21239179] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 11/25/2020] [Accepted: 11/30/2020] [Indexed: 12/12/2022] Open
Abstract
As a second messenger in cellular signal transduction, calcium signaling extensively participates in various physiological activities, including spermatogenesis and the regulation of sperm function. Abnormal calcium signaling is highly correlated with male infertility. Calcium signaling is mainly regulated by both extracellular calcium influx and the release of calcium stores. Inositol 1,4,5-trisphosphate receptor (IP3R) is a widely expressed channel for calcium stores. After being activated by inositol 1,4,5-trisphosphate (IP3) and calcium signaling at a lower concentration, IP3R can regulate the release of Ca2+ from stores into cytoplasm, and eventually trigger downstream events. The closure of the IP3R channel caused by a rise in intracellular calcium signals and the activation of the calcium pump jointly restores the calcium store to a normal level. In this review, we aim to discuss structural features of IP3R channels and the underlying mechanism of IP3R channel-mediated calcium signaling and further focus on the research progress of IP3R expression and function in the male reproductive system. Finally, we propose key directions and strategies for research of IP3R in spermatogenesis and the regulation of sperm function to provide more understanding of the function and mechanism of IP3R channel actions in male reproduction.
Collapse
|
11
|
Danese A, Marchi S, Vitto VAM, Modesti L, Leo S, Wieckowski MR, Giorgi C, Pinton P. Cancer-Related Increases and Decreases in Calcium Signaling at the Endoplasmic Reticulum-Mitochondria Interface (MAMs). Rev Physiol Biochem Pharmacol 2020; 185:153-193. [PMID: 32789789 DOI: 10.1007/112_2020_43] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Endoplasmic reticulum (ER)-mitochondria regions are specialized subdomains called also mitochondria-associated membranes (MAMs). MAMs allow regulation of lipid synthesis and represent hubs for ion and metabolite signaling. As these two organelles can module both the amplitude and the spatiotemporal patterns of calcium (Ca2+) signals, this particular interaction controls several Ca2+-dependent pathways well known for their contribution to tumorigenesis, such as metabolism, survival, sensitivity to cell death, and metastasis. Mitochondria-mediated apoptosis arises from mitochondrial Ca2+ overload, permeabilization of the mitochondrial outer membrane, and the release of mitochondrial apoptotic factors into the cytosol. Decreases in Ca2+ signaling at the ER-mitochondria interface are being studied in depth as failure of apoptotic-dependent cell death is one of the predominant characteristics of cancer cells. However, some recent papers that linked MAMs Ca2+ crosstalk-related upregulation to tumor onset and progression have aroused the interest of the scientific community.In this review, we will describe how different MAMs-localized proteins modulate the effectiveness of Ca2+-dependent apoptotic stimuli by causing both increases and decreases in the ER-mitochondria interplay and, specifically, by modulating Ca2+ signaling.
Collapse
Affiliation(s)
- Alberto Danese
- Department of Medical Sciences, Laboratory for Technologies of Advanced Therapies (LTTA), University of Ferrara, Ferrara, Italy
| | - Saverio Marchi
- Department of Clinical and Molecular Sciences, Marche Polytechnic University, Ancona, Italy
| | - Veronica Angela Maria Vitto
- Department of Medical Sciences, Laboratory for Technologies of Advanced Therapies (LTTA), University of Ferrara, Ferrara, Italy
| | - Lorenzo Modesti
- Department of Medical Sciences, Laboratory for Technologies of Advanced Therapies (LTTA), University of Ferrara, Ferrara, Italy
| | - Sara Leo
- Department of Medical Sciences, Laboratory for Technologies of Advanced Therapies (LTTA), University of Ferrara, Ferrara, Italy
| | - Mariusz R Wieckowski
- Laboratory of Mitochondrial Biology and Metabolism, Nencki Institute of Experimental Biology of Polish Academy of Sciences, Warsaw, Poland
| | - Carlotta Giorgi
- Department of Medical Sciences, Laboratory for Technologies of Advanced Therapies (LTTA), University of Ferrara, Ferrara, Italy
| | - Paolo Pinton
- Department of Medical Sciences, Laboratory for Technologies of Advanced Therapies (LTTA), University of Ferrara, Ferrara, Italy.
| |
Collapse
|
12
|
Denizot A, Arizono M, Nägerl UV, Soula H, Berry H. Simulation of calcium signaling in fine astrocytic processes: Effect of spatial properties on spontaneous activity. PLoS Comput Biol 2019; 15:e1006795. [PMID: 31425510 PMCID: PMC6726244 DOI: 10.1371/journal.pcbi.1006795] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Revised: 09/04/2019] [Accepted: 07/08/2019] [Indexed: 12/20/2022] Open
Abstract
Astrocytes, a glial cell type of the central nervous system, have emerged as detectors and regulators of neuronal information processing. Astrocyte excitability resides in transient variations of free cytosolic calcium concentration over a range of temporal and spatial scales, from sub-microdomains to waves propagating throughout the cell. Despite extensive experimental approaches, it is not clear how these signals are transmitted to and integrated within an astrocyte. The localization of the main molecular actors and the geometry of the system, including the spatial organization of calcium channels IP3R, are deemed essential. However, as most calcium signals occur in astrocytic ramifications that are too fine to be resolved by conventional light microscopy, most of those spatial data are unknown and computational modeling remains the only methodology to study this issue. Here, we propose an IP3R-mediated calcium signaling model for dynamics in such small sub-cellular volumes. To account for the expected stochasticity and low copy numbers, our model is both spatially explicit and particle-based. Extensive simulations show that spontaneous calcium signals arise in the model via the interplay between excitability and stochasticity. The model reproduces the main forms of calcium signals and indicates that their frequency crucially depends on the spatial organization of the IP3R channels. Importantly, we show that two processes expressing exactly the same calcium channels can display different types of calcium signals depending on the spatial organization of the channels. Our model with realistic process volume and calcium concentrations successfully reproduces spontaneous calcium signals that we measured in calcium micro-domains with confocal microscopy and predicts that local variations of calcium indicators might contribute to the diversity of calcium signals observed in astrocytes. To our knowledge, this model is the first model suited to investigate calcium dynamics in fine astrocytic processes and to propose plausible mechanisms responsible for their variability.
Collapse
Affiliation(s)
- Audrey Denizot
- INRIA, F-69603, Villeurbanne, France
- Univ Lyon, LIRIS, UMR5205 CNRS, F-69621, Villeurbanne, France
| | - Misa Arizono
- Interdisciplinary Institute for Neuroscience, Université de Bordeaux, Bordeaux, France
- Interdisciplinary Institute for Neuroscience, CNRS UMR 5297, Bordeaux, France
| | - U. Valentin Nägerl
- Interdisciplinary Institute for Neuroscience, Université de Bordeaux, Bordeaux, France
- Interdisciplinary Institute for Neuroscience, CNRS UMR 5297, Bordeaux, France
| | - Hédi Soula
- INRIA, F-69603, Villeurbanne, France
- Univ P&M Curie, CRC, INSERM UMRS 1138, F-75006, Paris, France
| | - Hugues Berry
- INRIA, F-69603, Villeurbanne, France
- Univ Lyon, LIRIS, UMR5205 CNRS, F-69621, Villeurbanne, France
| |
Collapse
|
13
|
Ashhad S, Narayanan R. Stores, Channels, Glue, and Trees: Active Glial and Active Dendritic Physiology. Mol Neurobiol 2019; 56:2278-2299. [PMID: 30014322 PMCID: PMC6394607 DOI: 10.1007/s12035-018-1223-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Accepted: 07/03/2018] [Indexed: 02/07/2023]
Abstract
Glial cells and neuronal dendrites were historically assumed to be passive structures that play only supportive physiological roles, with no active contribution to information processing in the central nervous system. Research spanning the past few decades has clearly established this assumption to be far from physiological realities. Whereas the discovery of active channel conductances and their localized plasticity was the turning point for dendritic structures, the demonstration that glial cells release transmitter molecules and communicate across the neuroglia syncytium through calcium wave propagation constituted path-breaking discoveries for glial cell physiology. An additional commonality between these two structures is the ability of calcium stores within their endoplasmic reticulum (ER) to support active propagation of calcium waves, which play crucial roles in the spatiotemporal integration of information within and across cells. Although there have been several demonstrations of regulatory roles of glial cells and dendritic structures in achieving common physiological goals such as information propagation and adaptability through plasticity, studies assessing physiological interactions between these two active structures have been few and far. This lacuna is especially striking given the strong connectivity that is known to exist between these two structures through several complex and tightly intercoupled mechanisms that also recruit their respective ER structures. In this review, we present brief overviews of the parallel literatures on active dendrites and active glial physiology and make a strong case for future studies to directly assess the strong interactions between these two structures in regulating physiology and pathophysiology of the brain.
Collapse
Affiliation(s)
- Sufyan Ashhad
- Department of Neurobiology, University of California at Los Angeles, Los Angeles, CA, 90095, USA
| | - Rishikesh Narayanan
- Cellular Neurophysiology Laboratory, Molecular Biophysics Unit, Indian Institute of Science, Bangalore, 560012, India.
| |
Collapse
|
14
|
Infection by the parasitic helminth Trichinella spiralis activates a Tas2r-mediated signaling pathway in intestinal tuft cells. Proc Natl Acad Sci U S A 2019; 116:5564-5569. [PMID: 30819885 PMCID: PMC6431192 DOI: 10.1073/pnas.1812901116] [Citation(s) in RCA: 130] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Intestinal tuft cells are sentinels monitoring the luminal contents and play a critical role in type 2 immunity. In this work, Trichinella spiralis excretion–secretion and extract were shown to directly induce interleukin 25 (IL-25) release from the intestinal villi, evoke calcium responses in tuft cells, and activate Tas2r bitter-taste receptors, whereas the bitter compound salicin was shown to activate and induce tuft cells to release IL-25. Gα-gustducin/Gβ1γ13 and/or Gαo/Gβ1γ13, Plcβ2, Ip3r2, and Trpm5 comprise the signal transduction pathways that tuft cells utilize to initiate type 2 immune responses. Potentiation of Trpm5 by a natural sweet compound, stevioside, can enhance the tuft cell–ILC2 circuit’s activity, indicating that modulating these signaling components can help devise new means of combating parasites. The parasitic helminth Trichinella spiralis, which poses a serious health risk to animals and humans, can be found worldwide. Recent findings indicate that a rare type of gut epithelial cell, tuft cells, can detect the helminth, triggering type 2 immune responses. However, the underlying molecular mechanisms remain to be fully understood. Here we show that both excretory–secretory products (E–S) and extract of T. spiralis can stimulate the release of the cytokine interleukin 25 (IL-25) from the mouse small intestinal villi and evoke calcium responses from tuft cells in the intestinal organoids, which can be blocked by a bitter-taste receptor inhibitor, allyl isothiocyanate. Heterologously expressed mouse Tas2r bitter-taste receptors, the expression of which is augmented during tuft-cell hyperplasia, can respond to the E–S and extract as well as to the bitter compound salicin whereas salicin in turn can induce IL-25 release from tuft cells. Furthermore, abolishment of the G-protein γ13 subunit, application of the inhibitors for G-protein αo/i, Gβγ subunits, and phospholipase Cβ2 dramatically reduces the IL-25 release. Finally, tuft cells are found to utilize the inositol triphosphate receptor type 2 (Ip3r2) to regulate cytosolic calcium and thus Trpm5 activity, while potentiation of Trpm5 by a sweet-tasting compound, stevioside, enhances tuft cell IL-25 release and hyperplasia in vivo. Taken together, T. spiralis infection activates a signaling pathway in intestinal tuft cells similar to that of taste-bud cells, but with some key differences, to initiate type 2 immunity.
Collapse
|
15
|
Research Progress on the Relationship Between Acute Pancreatitis and Calcium Overload in Acinar Cells. Dig Dis Sci 2019; 64:25-38. [PMID: 30284136 DOI: 10.1007/s10620-018-5297-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Accepted: 09/01/2018] [Indexed: 02/07/2023]
Abstract
Acute pancreatitis is a human disease with multiple causes that leads to autodigestion of the pancreas. There is sufficient evidence to support the key role of sustained increase in cytosolic calcium concentrations in the early pathogenesis of the disease. To clarify the mechanism of maintaining calcium homeostasis in the cell and pathological processes caused by calcium overload would help to research directly targeted therapeutic agents. We will specifically review the following: intracellular calcium homeostasis and regulation, the occurrence of calcium overload in acinar cells, the role of calcium overload in the pathogenesis of AP, the treatment strategy proposed for calcium overload.
Collapse
|
16
|
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.
Collapse
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
| |
Collapse
|
17
|
Zuccolo E, Laforenza U, Negri S, Botta L, Berra-Romani R, Faris P, Scarpellino G, Forcaia G, Pellavio G, Sancini G, Moccia F. Muscarinic M5 receptors trigger acetylcholine-induced Ca 2+ signals and nitric oxide release in human brain microvascular endothelial cells. J Cell Physiol 2018; 234:4540-4562. [PMID: 30191989 DOI: 10.1002/jcp.27234] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 07/24/2018] [Indexed: 12/13/2022]
Abstract
Basal forebrain neurons control cerebral blood flow (CBF) by releasing acetylcholine (Ach), which binds to endothelial muscarinic receptors to induce nitric (NO) release and vasodilation in intraparenchymal arterioles. Nevertheless, the mechanism whereby Ach stimulates human brain microvascular endothelial cells to produce NO is still unknown. Herein, we sought to assess whether Ach stimulates NO production in a Ca2+ -dependent manner in hCMEC/D3 cells, a widespread model of human brain microvascular endothelial cells. Ach induced a dose-dependent increase in intracellular Ca2+ concentration ([Ca2+ ]i ) that was prevented by the genetic blockade of M5 muscarinic receptors (M5-mAchRs), which was the only mAchR isoform coupled to phospholipase Cβ (PLCβ) present in hCMEC/D3 cells. A comprehensive real-time polymerase chain reaction analysis revealed the expression of the transcripts encoding for type 3 inositol-1,4,5-trisphosphate receptors (InsP3 R3), two-pore channels 1 and 2 (TPC1-2), Stim2, Orai1-3. Pharmacological manipulation showed that the Ca2+ response to Ach was mediated by InsP3 R3, TPC1-2, and store-operated Ca2+ entry (SOCE). Ach-induced NO release, in turn, was inhibited in cells deficient of M5-mAchRs. Likewise, Ach failed to increase NO levels in the presence of l-NAME, a selective NOS inhibitor, or BAPTA, a membrane-permeant intracellular Ca2+ buffer. Moreover, the pharmacological blockade of the Ca2+ response to Ach also inhibited the accompanying NO production. These data demonstrate for the first time that synaptically released Ach may trigger NO release in human brain microvascular endothelial cells by stimulating a Ca2+ signal via M5-mAchRs.
Collapse
Affiliation(s)
- Estella Zuccolo
- Department of Biology and Biotechnology, "Lazzaro Spallanzani," Laboratory of General Physiology, University of Pavia, Pavia, Italy
| | - Umberto Laforenza
- Department of Molecular Medicine, Human Physiology Unit, University of Pavia, Pavia, Italy
| | - Sharon Negri
- Department of Biology and Biotechnology, "Lazzaro Spallanzani," Laboratory of General Physiology, University of Pavia, Pavia, Italy
| | - Laura Botta
- Department of Biology and Biotechnology, "Lazzaro Spallanzani," Laboratory of General Physiology, University of Pavia, Pavia, Italy
| | - Roberto Berra-Romani
- Department of Biomedicine, School of Medicine, Benemérita Universidad Autónoma de Puebla, Puebla, Mexico
| | - Pawan Faris
- Department of Biology and Biotechnology, "Lazzaro Spallanzani," Laboratory of General Physiology, University of Pavia, Pavia, Italy.,Department of Biology, College of Science, Salahaddin University, Erbil, Iraq
| | - Giorgia Scarpellino
- Department of Biology and Biotechnology, "Lazzaro Spallanzani," Laboratory of General Physiology, University of Pavia, Pavia, Italy
| | - Greta Forcaia
- Department of Experimental Medicine, University of Milano-Bicocca, Monza, Italy
| | - Giorgia Pellavio
- Department of Molecular Medicine, Human Physiology Unit, University of Pavia, Pavia, Italy
| | - Giulio Sancini
- Department of Experimental Medicine, University of Milano-Bicocca, Monza, Italy
| | - Francesco Moccia
- Department of Biology and Biotechnology, "Lazzaro Spallanzani," Laboratory of General Physiology, University of Pavia, Pavia, Italy
| |
Collapse
|
18
|
Roest G, La Rovere RM, Bultynck G, Parys JB. IP 3 Receptor Properties and Function at Membrane Contact Sites. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 981:149-178. [PMID: 29594861 DOI: 10.1007/978-3-319-55858-5_7] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The inositol 1,4,5-trisphosphate (IP3) receptor (IP3R) is a ubiquitously expressed Ca2+-release channel localized in the endoplasmic reticulum (ER). The intracellular Ca2+ signals originating from the activation of the IP3R regulate multiple cellular processes including the control of cell death versus cell survival via their action on apoptosis and autophagy. The exact role of the IP3Rs in these two processes does not only depend on their activity, which is modulated by the cytosolic composition (Ca2+, ATP, redox status, …) and by various types of regulatory proteins, including kinases and phosphatases as well as by a number of oncogenes and tumor suppressors, but also on their intracellular localization, especially at the ER-mitochondrial and ER-lysosomal interfaces. At these interfaces, Ca2+ microdomains are formed, in which the Ca2+ concentration is finely regulated by the different ER, mitochondrial and lysosomal Ca2+-transport systems and also depends on the functional and structural interactions existing between them. In this review, we therefore discuss the most recent insights in the role of Ca2+ signaling in general, and of the IP3R in particular, in the control of basal mitochondrial bioenergetics, apoptosis, and autophagy at the level of inter-organellar contact sites.
Collapse
Affiliation(s)
- Gemma Roest
- Laboratory for Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine & Leuven Kanker Instituut, KU Leuven, Leuven, Belgium
| | - Rita M La Rovere
- Laboratory for Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine & Leuven Kanker Instituut, KU Leuven, Leuven, Belgium
| | - Geert Bultynck
- Laboratory for Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine & Leuven Kanker Instituut, KU Leuven, Leuven, Belgium.
| | - Jan B Parys
- Laboratory for Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine & Leuven Kanker Instituut, KU Leuven, Leuven, Belgium.
| |
Collapse
|
19
|
Eid AH, El-Yazbi AF, Zouein F, Arredouani A, Ouhtit A, Rahman MM, Zayed H, Pintus G, Abou-Saleh H. Inositol 1,4,5-Trisphosphate Receptors in Hypertension. Front Physiol 2018; 9:1018. [PMID: 30093868 PMCID: PMC6071574 DOI: 10.3389/fphys.2018.01018] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Accepted: 07/09/2018] [Indexed: 12/21/2022] Open
Abstract
Chronic hypertension remains a major cause of global mortality and morbidity. It is a complex disease that is the clinical manifestation of multiple genetic, environmental, nutritional, hormonal, and aging-related disorders. Evidence supports a role for vascular aging in the development of hypertension involving an impairment in endothelial function together with an alteration in vascular smooth muscle cells (VSMCs) calcium homeostasis leading to increased myogenic tone. Changes in free intracellular calcium levels ([Ca2+] i ) are mediated either by the influx of Ca2+ from the extracellular space or release of Ca2+ from intracellular stores, mainly the sarcoplasmic reticulum (SR). The influx of extracellular Ca2+ occurs primarily through voltage-gated Ca2+ channels (VGCCs), store-operated Ca2+ channels (SOC), and Ca2+ release-activated channels (CRAC), whereas SR-Ca2+ release occurs through inositol trisphosphate receptor (IP3R) and ryanodine receptors (RyRs). IP3R-mediated SR-Ca2+ release, in the form of Ca2+ waves, not only contributes to VSMC contraction and regulates VGCC function but is also intimately involved in structural remodeling of resistance arteries in hypertension. This involves a phenotypic switch of VSMCs as well as an alteration of cytoplasmic Ca2+ signaling machinery, a phenomena tightly related to the aging process. Several lines of evidence implicate changes in expression/function levels of IP3R isoforms in the development of hypertension, VSMC phenotypic switch, and vascular aging. The present review discusses the current knowledge of these mechanisms in an integrative approach and further suggests potential new targets for hypertension management and treatment.
Collapse
Affiliation(s)
- Ali H Eid
- Department of Pharmacology and Toxicology, Faculty of Medicine, American University of Beirut, Beirut, Lebanon.,Department of Biological and Environmental Sciences, College of Arts and Sciences, Qatar University, Doha, Qatar
| | - Ahmed F El-Yazbi
- Department of Pharmacology and Toxicology, Faculty of Medicine, American University of Beirut, Beirut, Lebanon.,Department of Pharmacology and Toxicology, Faculty of Pharmacy, Alexandria University, Alexandria, Egypt
| | - Fouad Zouein
- Department of Pharmacology and Toxicology, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
| | - Abdelilah Arredouani
- Qatar Biomedical Research Institute, Hamad Bin Khalifa University, Qatar Foundation, Doha, Qatar
| | - Allal Ouhtit
- Department of Biological and Environmental Sciences, College of Arts and Sciences, Qatar University, Doha, Qatar
| | - Md M Rahman
- Department of Biological and Environmental Sciences, College of Arts and Sciences, Qatar University, Doha, Qatar
| | - Hatem Zayed
- Department of Biomedical Sciences, College of Health Sciences, Qatar University, Doha, Qatar
| | - Gianfranco Pintus
- Department of Biomedical Sciences, College of Health Sciences, Qatar University, Doha, Qatar
| | - Haissam Abou-Saleh
- Department of Biological and Environmental Sciences, College of Arts and Sciences, Qatar University, Doha, Qatar
| |
Collapse
|
20
|
Decrock E, Hoorelbeke D, Ramadan R, Delvaeye T, De Bock M, Wang N, Krysko DV, Baatout S, Bultynck G, Aerts A, Vinken M, Leybaert L. Calcium, oxidative stress and connexin channels, a harmonious orchestra directing the response to radiotherapy treatment? BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2017; 1864:1099-1120. [DOI: 10.1016/j.bbamcr.2017.02.007] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 02/02/2017] [Accepted: 02/04/2017] [Indexed: 02/07/2023]
|
21
|
Tykocki NR, Boerman EM, Jackson WF. Smooth Muscle Ion Channels and Regulation of Vascular Tone in Resistance Arteries and Arterioles. Compr Physiol 2017; 7:485-581. [PMID: 28333380 DOI: 10.1002/cphy.c160011] [Citation(s) in RCA: 212] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Vascular tone of resistance arteries and arterioles determines peripheral vascular resistance, contributing to the regulation of blood pressure and blood flow to, and within the body's tissues and organs. Ion channels in the plasma membrane and endoplasmic reticulum of vascular smooth muscle cells (SMCs) in these blood vessels importantly contribute to the regulation of intracellular Ca2+ concentration, the primary determinant of SMC contractile activity and vascular tone. Ion channels provide the main source of activator Ca2+ that determines vascular tone, and strongly contribute to setting and regulating membrane potential, which, in turn, regulates the open-state-probability of voltage gated Ca2+ channels (VGCCs), the primary source of Ca2+ in resistance artery and arteriolar SMCs. Ion channel function is also modulated by vasoconstrictors and vasodilators, contributing to all aspects of the regulation of vascular tone. This review will focus on the physiology of VGCCs, voltage-gated K+ (KV) channels, large-conductance Ca2+-activated K+ (BKCa) channels, strong-inward-rectifier K+ (KIR) channels, ATP-sensitive K+ (KATP) channels, ryanodine receptors (RyRs), inositol 1,4,5-trisphosphate receptors (IP3Rs), and a variety of transient receptor potential (TRP) channels that contribute to pressure-induced myogenic tone in resistance arteries and arterioles, the modulation of the function of these ion channels by vasoconstrictors and vasodilators, their role in the functional regulation of tissue blood flow and their dysfunction in diseases such as hypertension, obesity, and diabetes. © 2017 American Physiological Society. Compr Physiol 7:485-581, 2017.
Collapse
Affiliation(s)
- Nathan R Tykocki
- Department of Pharmacology, University of Vermont, Burlington, Vermont, USA
| | - Erika M Boerman
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri, USA
| | - William F Jackson
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, Michigan, USA
| |
Collapse
|
22
|
From Stores to Sinks: Structural Mechanisms of Cytosolic Calcium Regulation. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 981:215-251. [PMID: 29594864 DOI: 10.1007/978-3-319-55858-5_10] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/08/2022]
Abstract
All eukaryotic cells have adapted the use of the calcium ion (Ca2+) as a universal signaling element through the evolution of a toolkit of Ca2+ sensor, buffer and effector proteins. Among these toolkit components, integral and peripheral proteins decorate biomembranes and coordinate the movement of Ca2+ between compartments, sense these concentration changes and elicit physiological signals. These changes in compartmentalized Ca2+ levels are not mutually exclusive as signals propagate between compartments. For example, agonist induced surface receptor stimulation can lead to transient increases in cytosolic Ca2+ sourced from endoplasmic reticulum (ER) stores; the decrease in ER luminal Ca2+ can subsequently signal the opening surface channels which permit the movement of Ca2+ from the extracellular space to the cytosol. Remarkably, the minuscule compartments of mitochondria can function as significant cytosolic Ca2+ sinks by taking up Ca2+ in a coordinated manner. In non-excitable cells, inositol 1,4,5 trisphosphate receptors (IP3Rs) on the ER respond to surface receptor stimulation; stromal interaction molecules (STIMs) sense the ER luminal Ca2+ depletion and activate surface Orai1 channels; surface Orai1 channels selectively permit the movement of Ca2+ from the extracellular space to the cytosol; uptake of Ca2+ into the matrix through the mitochondrial Ca2+ uniporter (MCU) further shapes the cytosolic Ca2+ levels. Recent structural elucidations of these key Ca2+ toolkit components have improved our understanding of how they function to orchestrate precise cytosolic Ca2+ levels for specific physiological responses. This chapter reviews the atomic-resolution structures of IP3R, STIM1, Orai1 and MCU elucidated by X-ray crystallography, electron microscopy and NMR and discusses the mechanisms underlying their biological functions in their respective compartments within the cell.
Collapse
|
23
|
Kerkhofs M, Giorgi C, Marchi S, Seitaj B, Parys JB, Pinton P, Bultynck G, Bittremieux M. Alterations in Ca 2+ Signalling via ER-Mitochondria Contact Site Remodelling in Cancer. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 997:225-254. [PMID: 28815534 DOI: 10.1007/978-981-10-4567-7_17] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Inter-organellar contact sites establish microdomains for localised Ca2+-signalling events. One of these microdomains is established between the ER and the mitochondria. Importantly, the so-called mitochondria-associated ER membranes (MAMs) contain, besides structural proteins and proteins involved in lipid exchange, several Ca2+-transport systems, mediating efficient Ca2+ transfer from the ER to the mitochondria. These Ca2+ signals critically control several mitochondrial functions, thereby impacting cell metabolism, cell death and survival, proliferation and migration. Hence, the MAMs have emerged as critical signalling hubs in physiology, while their dysregulation is an important factor that drives or at least contributes to oncogenesis and tumour progression. In this book chapter, we will provide an overview of the role of the MAMs in cell function and how alterations in the MAM composition contribute to oncogenic features and behaviours.
Collapse
Affiliation(s)
- Martijn Kerkhofs
- Laboratory Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine and Leuven Kanker Instituut (LKI), KU Leuven, Campus Gasthuisberg O&N 1 Box 802, Herestraat 49, 3000, Leuven, Belgium
| | - Carlotta Giorgi
- Laboratory for Technologies of Advanced Therapies (LTTA), Department of Morphology, Surgery and Experimental Medicine, Section of Pathology, Oncology and Experimental Biology, University of Ferrara, Ferrara, Italy
| | - Saverio Marchi
- Laboratory for Technologies of Advanced Therapies (LTTA), Department of Morphology, Surgery and Experimental Medicine, Section of Pathology, Oncology and Experimental Biology, University of Ferrara, Ferrara, Italy
| | - Bruno Seitaj
- Laboratory Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine and Leuven Kanker Instituut (LKI), KU Leuven, Campus Gasthuisberg O&N 1 Box 802, Herestraat 49, 3000, Leuven, Belgium
| | - Jan B Parys
- Laboratory Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine and Leuven Kanker Instituut (LKI), KU Leuven, Campus Gasthuisberg O&N 1 Box 802, Herestraat 49, 3000, Leuven, Belgium
| | - Paolo Pinton
- Laboratory for Technologies of Advanced Therapies (LTTA), Department of Morphology, Surgery and Experimental Medicine, Section of Pathology, Oncology and Experimental Biology, University of Ferrara, Ferrara, Italy
| | - Geert Bultynck
- Laboratory Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine and Leuven Kanker Instituut (LKI), KU Leuven, Campus Gasthuisberg O&N 1 Box 802, Herestraat 49, 3000, Leuven, Belgium.
| | - Mart Bittremieux
- Laboratory Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine and Leuven Kanker Instituut (LKI), KU Leuven, Campus Gasthuisberg O&N 1 Box 802, Herestraat 49, 3000, Leuven, Belgium
| |
Collapse
|
24
|
Fedorenko YA. Conductance of Channels of IP3 Receptors of the Nuclear Envelope in Purkinje Neurons. NEUROPHYSIOLOGY+ 2016. [DOI: 10.1007/s11062-016-9573-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
25
|
Neymotin SA, McDougal RA, Bulanova AS, Zeki M, Lakatos P, Terman D, Hines ML, Lytton WW. Calcium regulation of HCN channels supports persistent activity in a multiscale model of neocortex. Neuroscience 2016; 316:344-66. [PMID: 26746357 PMCID: PMC4724569 DOI: 10.1016/j.neuroscience.2015.12.043] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Revised: 12/16/2015] [Accepted: 12/21/2015] [Indexed: 01/08/2023]
Abstract
Neuronal persistent activity has been primarily assessed in terms of electrical mechanisms, without attention to the complex array of molecular events that also control cell excitability. We developed a multiscale neocortical model proceeding from the molecular to the network level to assess the contributions of calcium (Ca(2+)) regulation of hyperpolarization-activated cyclic nucleotide-gated (HCN) channels in providing additional and complementary support of continuing activation in the network. The network contained 776 compartmental neurons arranged in the cortical layers, connected using synapses containing AMPA/NMDA/GABAA/GABAB receptors. Metabotropic glutamate receptors (mGluR) produced inositol triphosphate (IP3) which caused the release of Ca(2+) from endoplasmic reticulum (ER) stores, with reuptake by sarco/ER Ca(2+)-ATP-ase pumps (SERCA), and influence on HCN channels. Stimulus-induced depolarization led to Ca(2+) influx via NMDA and voltage-gated Ca(2+) channels (VGCCs). After a delay, mGluR activation led to ER Ca(2+) release via IP3 receptors. These factors increased HCN channel conductance and produced firing lasting for ∼1min. The model displayed inter-scale synergies among synaptic weights, excitation/inhibition balance, firing rates, membrane depolarization, Ca(2+) levels, regulation of HCN channels, and induction of persistent activity. The interaction between inhibition and Ca(2+) at the HCN channel nexus determined a limited range of inhibition strengths for which intracellular Ca(2+) could prepare population-specific persistent activity. Interactions between metabotropic and ionotropic inputs to the neuron demonstrated how multiple pathways could contribute in a complementary manner to persistent activity. Such redundancy and complementarity via multiple pathways is a critical feature of biological systems. Mediation of activation at different time scales, and through different pathways, would be expected to protect against disruption, in this case providing stability for persistent activity.
Collapse
Affiliation(s)
- S A Neymotin
- Department of Physiology & Pharmacology, SUNY Downstate, 450 Clarkson Avenue, Brooklyn, NY 11203, USA; Department of Neuroscience, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA.
| | - R A McDougal
- Department of Neuroscience, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA.
| | - A S Bulanova
- Department of Physiology & Pharmacology, SUNY Downstate, 450 Clarkson Avenue, Brooklyn, NY 11203, USA; Department of Neuroscience, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA.
| | - M Zeki
- Department of Mathematics, Zirve University, 27260 Gaziantep, Turkey.
| | - P Lakatos
- Nathan Kline Institute for Psychiatric Research, 140 Old Orangeburg Road, Orangeburg, NY 10962, USA.
| | - D Terman
- Department of Mathematics, The Ohio State University, 231 W 18th Avenue, Columbus, OH 43210, USA.
| | - M L Hines
- Department of Neuroscience, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA.
| | - W W Lytton
- Department of Physiology & Pharmacology, SUNY Downstate, 450 Clarkson Avenue, Brooklyn, NY 11203, USA; Department of Neurology, SUNY Downstate, 450 Clarkson Avenue, Brooklyn, NY 11203, USA; Department Neurology, Kings County Hospital Center, 451 Clarkson Avenue, Brooklyn, NY 11203, USA.
| |
Collapse
|
26
|
Toussaint F, Charbel C, Blanchette A, Ledoux J. CaMKII regulates intracellular Ca²⁺ dynamics in native endothelial cells. Cell Calcium 2015; 58:275-85. [PMID: 26100947 DOI: 10.1016/j.ceca.2015.06.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2014] [Revised: 05/15/2015] [Accepted: 06/06/2015] [Indexed: 01/11/2023]
Abstract
Localized endothelial Ca(2+) signalling, such as Ca(2+) pulsars, can modulate the contractile state of the underlying vascular smooth muscle cell through specific endothelial targets. In addition to K(Ca)3.1 as a target, Ca(2+) pulsars, an IP3R-dependent pulsatile Ca(2+) release from the endoplasmic reticulum (ER) could activate a frequency-sensitive Ca(2+)-dependent kinase such as CaMKII. In the absence of extracellular Ca(2+), acetylcholine increased endothelial CaMKII phosphorylation and activation, thereby suggesting CaMKII activation independently of Ca(2+) influx. Herein, a reciprocal relation where CaMKII controls endothelial Ca(2+) dynamics has been investigated in mesenteric arteries. Both CaMKIIα and β isoforms have been identified in endothelial cells and close proximity (<40 nm) suggests their association in heteromultimers. Intracellular Ca(2+) monitoring with high speed confocal microscopy then showed that inhibition of CaMKII with KN-93 significantly increased the population of Ca(2+) pulsars active sites (+89%), suggesting CaMKII as a major regulator of Ca(2+) pulsars in native endothelium. Mechanistic insights were then sought through the elucidation of the impact of CaMKII on ER Ca(2+) store. ER Ca(2+) emptying was accelerated by CaMKII inhibition and ER Ca(2+) content was assessed using ionomycin. Exposure to KN-93 strongly diminished ER Ca(2+) content (-61%) by relieving CaMKII-dependent inhibition of IP3 receptors (IP3R). Moreover, in situ proximity ligation assay suggested CaMKII-IP3R promiscuity, essential condition for a protein-protein interaction. Interestingly, segregation of IP3R within myoendothelial projection (MEP) appears to be isoform-specific. Hence, only IP3R type 1 and type 2 are detected within fenestrations of the internal elastic lamina, sites of MEP, whilst type 3 is absent from these structures. In summary, CaMKII seems to act as a Ca(2+)-sensitive switch of a negative feedback loop regulating endothelial Ca(2+) homeostasis, including Ca(2+) pulsars.
Collapse
Affiliation(s)
- Fanny Toussaint
- Research Center, Montreal Heart Institute, Montréal, Québec, Canada; Department of Physiology, Université de Montréal, Québec, Canada
| | - Chimène Charbel
- Research Center, Montreal Heart Institute, Montréal, Québec, Canada; Department of Pharmacology, Université de Montréal, Québec, Canada
| | | | - Jonathan Ledoux
- Research Center, Montreal Heart Institute, Montréal, Québec, Canada; Department of Physiology, Université de Montréal, Québec, Canada; Department of Pharmacology, Université de Montréal, Québec, Canada; Department of Medicine, Université de Montréal, Québec, Canada.
| |
Collapse
|
27
|
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.
Collapse
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.
| |
Collapse
|
28
|
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.
Collapse
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.
| |
Collapse
|
29
|
Properties of Inositol 1,4,5-Trisphosphate Receptors in the Nuclei of CNS Neurons in Rats. NEUROPHYSIOLOGY+ 2014. [DOI: 10.1007/s11062-014-9439-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
30
|
Means SA, Cheng LK. Mitochondrial calcium handling within the interstitial cells of Cajal. Am J Physiol Gastrointest Liver Physiol 2014; 307:G107-21. [PMID: 24789203 PMCID: PMC4080165 DOI: 10.1152/ajpgi.00380.2013] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The interstitial cells of Cajal (ICC) drive rhythmic pacemaking contractions in the gastrointestinal system. The ICC generate pacemaking signals by membrane depolarizations associated with the release of intracellular calcium (Ca(2+)) in the endoplasmic reticulum (ER) through inositol-trisphosphate (IP3) receptors (IP3R) and uptake by mitochondria (MT). This Ca(2+) dynamic is hypothesized to generate pacemaking signals by calibrating ER Ca(2+) store depletions and membrane depolarization with ER store-operated Ca(2+) entry mechanisms. Using a biophysically based spatio-temporal model of integrated Ca(2+) transport in the ICC, we determined the feasibility of ER depletion timescale correspondence with experimentally observed pacemaking frequencies while considering the impact of IP3R Ca(2+) release and MT uptake on bulk cytosolic Ca(2+) levels because persistent elevations of free intracellular Ca(2+) are toxic to the cell. MT densities and distributions are varied in the model geometry to observe MT influence on free cytosolic Ca(2+) and the resulting frequencies of ER Ca(2+) store depletions, as well as the sarco-endoplasmic reticulum Ca(2+) ATP-ase (SERCA) and IP3 agonist concentrations. Our simulations show that high MT densities observed in the ICC are more relevant to ER establishing Ca(2+) depletion frequencies than protection of the cytosol from elevated free Ca(2+), whereas the SERCA pump is more relevant to containing cytosolic Ca(2+) elevations. Our results further suggest that the level of IP3 agonist stimulating ER Ca(2+) release, subsequent MT uptake, and eventual activation of ER store-operated Ca(2+) entry may determine frequencies of rhythmic pacemaking exhibited by the ICC across species and tissue types.
Collapse
Affiliation(s)
- Shawn A. Means
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
| | - Leo K. Cheng
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
| |
Collapse
|
31
|
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.
Collapse
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.
| |
Collapse
|
32
|
Fedorenko OA, Popugaeva E, Enomoto M, Stathopulos PB, Ikura M, Bezprozvanny I. Intracellular calcium channels: inositol-1,4,5-trisphosphate receptors. Eur J Pharmacol 2013; 739:39-48. [PMID: 24300389 DOI: 10.1016/j.ejphar.2013.10.074] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Revised: 09/28/2013] [Accepted: 10/17/2013] [Indexed: 01/13/2023]
Abstract
The inositol-1,4,5-trisphosphate receptors (InsP3Rs) are the major intracellular Ca(2+)-release channels in cells. Activity of InsP3Rs is essential for elementary and global Ca(2+) events in the cell. There are three InsP3Rs isoforms that are present in mammalian cells. In this review we will focus primarily on InsP3R type 1. The InsP3R1 is a predominant isoform in neurons and it is the most extensively studied isoform. Combination of biophysical and structural methods revealed key mechanisms of InsP3R function and modulation. Cell biological and biochemical studies lead to identification of a large number of InsP3R-binding proteins. InsP3Rs are involved in the regulation of numerous physiological processes, including learning and memory, proliferation, differentiation, development and cell death. Malfunction of InsP3R1 play a role in a number of neurodegenerative disorders and other disease states. InsP3Rs represent a potentially valuable drug target for treatment of these disorders and for modulating activity of neurons and other cells. Future studies will provide better understanding of physiological functions of InsP3Rs in health and disease.
Collapse
Affiliation(s)
- Olena A Fedorenko
- Department of Brain Physiology, Bogomoletz Institute of Physiology, 01024 Kiev, Ukraine; State Key Laboratory of Molecular and Cellular Biology, 01024 Kiev, Ukraine
| | - Elena Popugaeva
- Laboratory of Molecular Neurodegeneration, Department of Medical Physics, St. Petersburg State Polytechnical University, 195251 St. Petersburg, Russia
| | - Masahiro Enomoto
- Princess Margaret Cancer Centre, Department of Medical Biophysics, University of Toronto, M5G1L7 Toronto, Ontario, Canada
| | - Peter B Stathopulos
- Princess Margaret Cancer Centre, Department of Medical Biophysics, University of Toronto, M5G1L7 Toronto, Ontario, Canada
| | - Mitsuhiko Ikura
- Princess Margaret Cancer Centre, Department of Medical Biophysics, University of Toronto, M5G1L7 Toronto, Ontario, Canada
| | - Ilya Bezprozvanny
- Laboratory of Molecular Neurodegeneration, Department of Medical Physics, St. Petersburg State Polytechnical University, 195251 St. Petersburg, Russia; Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
| |
Collapse
|
33
|
Mauban JRH, Zacharia J, Zhang J, Wier WG. Vascular tone and Ca(2+) signaling in murine cremaster muscle arterioles in vivo. Microcirculation 2013; 20:269-77. [PMID: 23140521 DOI: 10.1111/micc.12025] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2012] [Accepted: 11/02/2012] [Indexed: 12/12/2022]
Abstract
OBJECTIVES We sought to determine some of the molecular requirements for basal state "tone" of skeletal muscle arterioles in vivo, and whether asynchronous Ca(2+) waves are involved or not. METHODS Cremaster muscles of anesthetized exMLCK and smGCaMP2 biosensor mice were exteriorized, and the fluorescent arterioles were visualized with wide-field, confocal or multiphoton microscopy to observe Ca(2+) signaling and arteriolar diameter. RESULTS Basal state tone of the arterioles was ~50%. Local block of Ang-II receptors (AT1 ) or α1 -adrenoceptors (α1 -AR) had no effect on diameter, nor did complete block of sympathetic nerve activity (SNA). Inhibition of phospholipase C caused dilation nearly to the Ca(2+) -free (passive) diameter, as did exposure to nifedipine or 2-APB. Arterioles were also dilated when treated with SKF96365. High-resolution imaging of exMLCK fluorescence (ratio) or GCaMP2 fluorescence in smooth muscle cells failed to reveal Ca(2+) waves (although Ca(2+) waves/transients were readily detected by both biosensors in small arteries, ex vivo). CONCLUSIONS Arterioles of cremaster muscle have vascular tone of ~ 50%, which is not due to α1 -AR, AT1 R, or SNA. PLC activity, L-type Ca(2+) channels, 2-APB- and SKF96365-sensitive channels are required. Propagating Ca(2+) waves are not present. A key role for PLC and InsP3 R in vascular tone in vivo, other than producing Ca(2+) waves, is suggested.
Collapse
Affiliation(s)
- Joseph R H Mauban
- Department of Physiology, School of Medicine, University of Maryland Baltimore, Baltimore, Maryland 21201, USA
| | | | | | | |
Collapse
|
34
|
Bezprozvanny I. Bilayer measurement of endoplasmic reticulum Ca2+ channels. Cold Spring Harb Protoc 2013; 2013:2013/11/pdb.top066225. [PMID: 24184754 DOI: 10.1101/pdb.top066225] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Reconstitution of ion channels into planar lipid bilayers (also called black lipid membranes or BLM) is the most widely used method to conduct physiological studies of intracellular ion channels, including endoplasmic reticulum (ER) calcium (Ca(2+)) channels. The two main types of Ca(2+) release channels in the ER membrane are ryanodine receptors (RyanRs) and inositol(1,4,5)-trisphosphate receptors (InsP3Rs). Use of the BLM reconstitution technique enabled the initial description of the functional properties of InsP3R and RyanR at the single-channel level more than 20 years ago. Since then, BLM reconstitution methods have been used to study physiological modulation and to perform structure-function analysis of these channels, and to study pathological changes in the function of InsP3R and RyanR in various disease states. The BLM technique has also been useful for studies of other intracellular Ca(2+) channels, such as ER Ca(2+) leak presenilin channels and NAADP-gated lysosomal Ca(2+) channels encoded by TPC2. In this article, basic protocols used for BLM studies of ER Ca(2+) channels are introduced.
Collapse
Affiliation(s)
- Ilya Bezprozvanny
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, Texas 75390
| |
Collapse
|
35
|
Ashmole I, Bradding P. Ion channels regulating mast cell biology. Clin Exp Allergy 2013; 43:491-502. [PMID: 23600539 DOI: 10.1111/cea.12043] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2012] [Revised: 07/06/2012] [Accepted: 08/28/2012] [Indexed: 11/28/2022]
Abstract
Mast cells play a central role in the pathophysiology of asthma and related allergic conditions. Mast cell activation leads to the degranulation of preformed mediators such as histamine and the secretion of newly synthesised proinflammatory mediators such as leukotrienes and cytokines. Excess release of these mediators contributes to allergic disease states. An influx of extracellular Ca2+ is essential for mast cell mediator release. From the Ca2+ channels that mediate this influx, to the K+ , Cl- and transient receptor potential channels that set the cell membrane potential and regulate Ca2+ influx, ion channels play a critical role in mast cell biology. In this review we provide an overview of our current knowledge of ion channel expression and function in mast cells with an emphasis on how channels interact to regulate Ca2+ signalling.
Collapse
Affiliation(s)
- I Ashmole
- Department of Infection, Immunity and Inflammation, Institute for Lung Heath, Glenfield Hospital, University of Leicester, Leicester, LE3 9QP, UK
| | | |
Collapse
|
36
|
Alzayady KJ, Wagner LE, Chandrasekhar R, Monteagudo A, Godiska R, Tall GG, Joseph SK, Yule DI. Functional inositol 1,4,5-trisphosphate receptors assembled from concatenated homo- and heteromeric subunits. J Biol Chem 2013; 288:29772-84. [PMID: 23955339 DOI: 10.1074/jbc.m113.502203] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Vertebrate genomes code for three subtypes of inositol 1,4,5-trisphosphate (IP3) receptors (IP3R1, -2, and -3). Individual IP3R monomers are assembled to form homo- and heterotetrameric channels that mediate Ca(2+) release from intracellular stores. IP3R subtypes are regulated differentially by IP3, Ca(2+), ATP, and various other cellular factors and events. IP3R subtypes are seldom expressed in isolation in individual cell types, and cells often express different complements of IP3R subtypes. When multiple subtypes of IP3R are co-expressed, the subunit composition of channels cannot be specifically defined. Thus, how the subunit composition of heterotetrameric IP3R channels contributes to shaping the spatio-temporal properties of IP3-mediated Ca(2+) signals has been difficult to evaluate. To address this question, we created concatenated IP3R linked by short flexible linkers. Dimeric constructs were expressed in DT40-3KO cells, an IP3R null cell line. The dimeric proteins were localized to membranes, ran as intact dimeric proteins on SDS-PAGE, and migrated as an ∼1100-kDa band on blue native gels exactly as wild type IP3R. Importantly, IP3R channels formed from concatenated dimers were fully functional as indicated by agonist-induced Ca(2+) release. Using single channel "on-nucleus" patch clamp, the channels assembled from homodimers were essentially indistinguishable from those formed by the wild type receptor. However, the activity of channels formed from concatenated IP3R1 and IP3R2 heterodimers was dominated by IP3R2 in terms of the characteristics of regulation by ATP. These studies provide the first insight into the regulation of heterotetrameric IP3R of defined composition. Importantly, the results indicate that the properties of these channels are not simply a blend of those of the constituent IP3R monomers.
Collapse
Affiliation(s)
- Kamil J Alzayady
- From the Department of Pharmacology and Physiology, University of Rochester, Rochester, New York 14642
| | | | | | | | | | | | | | | |
Collapse
|
37
|
De Bock M, Wang N, Decrock E, Bol M, Gadicherla AK, Culot M, Cecchelli R, Bultynck G, Leybaert L. Endothelial calcium dynamics, connexin channels and blood-brain barrier function. Prog Neurobiol 2013; 108:1-20. [PMID: 23851106 DOI: 10.1016/j.pneurobio.2013.06.001] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2013] [Revised: 06/12/2013] [Accepted: 06/18/2013] [Indexed: 01/11/2023]
Abstract
Situated between the circulation and the brain, the blood-brain barrier (BBB) protects the brain from circulating toxins while securing a specialized environment for neuro-glial signaling. BBB capillary endothelial cells exhibit low transcytotic activity and a tight, junctional network that, aided by the cytoskeleton, restricts paracellular permeability. The latter is subject of extensive research as it relates to neuropathology, edema and inflammation. A key determinant in regulating paracellular permeability is the endothelial cytoplasmic Ca(2+) concentration ([Ca(2+)]i) that affects junctional and cytoskeletal proteins. Ca(2+) signals are not one-time events restricted to a single cell but often appear as oscillatory [Ca(2+)]i changes that may propagate between cells as intercellular Ca(2+) waves. The effect of Ca(2+) oscillations/waves on BBB function is largely unknown and we here review current evidence on how [Ca(2+)]i dynamics influence BBB permeability.
Collapse
Affiliation(s)
- Marijke De Bock
- Dept. of Basic Medical Sciences, Ghent University, Ghent, Belgium.
| | | | | | | | | | | | | | | | | |
Collapse
|
38
|
Lock JT, Sinkins WG, Schilling WP. Protein S-glutathionylation enhances Ca2+-induced Ca2+ release via the IP3 receptor in cultured aortic endothelial cells. J Physiol 2013. [PMID: 22855054 DOI: 10.1113/jphysiol.2012.230656] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
In non-excitable cells, thiol-oxidizing agents have been shown to evoke oscillations in cytosolic free Ca(2+) concentration ([Ca(2+)](i)) by increasing the sensitivity of the inositol 1,4,5-trisphosphate (IP(3)) receptor (IP(3)R) to IP(3). Although thiol modification of the IP(3)R is implicated in this response, the molecular nature of the modification(s) responsible for changes in channel activity is still not well understood. Diamide is a chemical oxidant that selectively converts reduced glutathione (GSH) to its disulfide (GSSG) and promotes the formation of protein–glutathione (P-SSG) mixed disulfide, i.e. glutathionylation. In the present study, we examined the effect of diamide, and the model oxidant hydrogen peroxide (H(2)O(2)), on oscillations in [Ca(2+)](i) in fura-2-loaded bovine (BAECs) and human (HAECs) aortic endo-thelial cells using time-lapse fluorescence video microscopy. In the absence of extracellular Ca(2+), acute treatment with either diamide or H(2)O(2) increased the number of BAECs exhibiting asynchronous Ca(2+) oscillations, whereas HAECs were unexpectedly resistant. Diamide pretreatment increased the sensitivity of HAECs to histamine-stimulated Ca(2+) oscillations and BAECs to bradykinin-stimulated Ca(2+) oscillations. Moreover, in both HAECs and BAECs, diamide dramatically increased both the rate and magnitude of the thapsigargin-induced Ca(2+) transient suggesting that Ca(2+)-induced Ca(2+) release (CICR) via the IP(3)R is enhanced by glutathionylation. Similar to diamide, H(2)O(2) increased the sensitivity of HAECs to both histamine and thapsigargin. Lastly, biochemical studies showed that glutathionylation of native IP(3)R(1) is increased in cells challenged with H(2)O(2). Collectively our results reveal that thiol-oxidizing agents primarily increase the sensitivity of the IP(3)R to Ca(2+), i.e. enhanced CICR, and suggest that glutathionylation may represent a fundamental mechanism for regulating IP(3)R activity during physiological redox signalling and during pathologicalical oxidative stress.
Collapse
Affiliation(s)
- Jeffrey T Lock
- W. P. Schilling: Rammelkamp Center, Rm R-322, MetroHealth Medical Center, 2500 MetroHealth Drive, Cleveland, OH 44109, USA
| | | | | |
Collapse
|
39
|
Lock JT, Sinkins WG, Schilling WP. Protein S-glutathionylation enhances Ca2+-induced Ca2+ release via the IP3 receptor in cultured aortic endothelial cells. J Physiol 2013; 590:3631-2. [PMID: 22855054 DOI: 10.1113/jphysiol.2012.232645] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
In non-excitable cells, thiol-oxidizing agents have been shown to evoke oscillations in cytosolic free Ca(2+) concentration ([Ca(2+)](i)) by increasing the sensitivity of the inositol 1,4,5-trisphosphate (IP(3)) receptor (IP(3)R) to IP(3). Although thiol modification of the IP(3)R is implicated in this response, the molecular nature of the modification(s) responsible for changes in channel activity is still not well understood. Diamide is a chemical oxidant that selectively converts reduced glutathione (GSH) to its disulfide (GSSG) and promotes the formation of protein–glutathione (P-SSG) mixed disulfide, i.e. glutathionylation. In the present study, we examined the effect of diamide, and the model oxidant hydrogen peroxide (H(2)O(2)), on oscillations in [Ca(2+)](i) in fura-2-loaded bovine (BAECs) and human (HAECs) aortic endo-thelial cells using time-lapse fluorescence video microscopy. In the absence of extracellular Ca(2+), acute treatment with either diamide or H(2)O(2) increased the number of BAECs exhibiting asynchronous Ca(2+) oscillations, whereas HAECs were unexpectedly resistant. Diamide pretreatment increased the sensitivity of HAECs to histamine-stimulated Ca(2+) oscillations and BAECs to bradykinin-stimulated Ca(2+) oscillations. Moreover, in both HAECs and BAECs, diamide dramatically increased both the rate and magnitude of the thapsigargin-induced Ca(2+) transient suggesting that Ca(2+)-induced Ca(2+) release (CICR) via the IP(3)R is enhanced by glutathionylation. Similar to diamide, H(2)O(2) increased the sensitivity of HAECs to both histamine and thapsigargin. Lastly, biochemical studies showed that glutathionylation of native IP(3)R(1) is increased in cells challenged with H(2)O(2). Collectively our results reveal that thiol-oxidizing agents primarily increase the sensitivity of the IP(3)R to Ca(2+), i.e. enhanced CICR, and suggest that glutathionylation may represent a fundamental mechanism for regulating IP(3)R activity during physiological redox signalling and during pathologicalical oxidative stress.
Collapse
Affiliation(s)
- Jeffrey T Lock
- W. P. Schilling: Rammelkamp Center, Rm R-322, MetroHealth Medical Center, 2500 MetroHealth Drive, Cleveland, OH 44109, USA
| | | | | |
Collapse
|
40
|
Dabertrand F, Nelson MT, Brayden JE. Ryanodine receptors, calcium signaling, and regulation of vascular tone in the cerebral parenchymal microcirculation. Microcirculation 2013; 20:307-16. [PMID: 23216877 PMCID: PMC3612564 DOI: 10.1111/micc.12027] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2012] [Accepted: 11/21/2012] [Indexed: 11/27/2022]
Abstract
The cerebral blood supply is delivered by a surface network of pial arteries and arterioles from which arise (parenchymal) arterioles that penetrate into the cortex and terminate in a rich capillary bed. The critical regulation of CBF, locally and globally, requires precise vasomotor regulation of the intracerebral microvasculature. This vascular region is anatomically unique as illustrated by the presence of astrocytic processes that envelope almost the entire basolateral surface of PAs. There are, moreover, notable functional differences between pial arteries and PAs. For example, in pial VSMCs, local calcium release events ("calcium sparks") through ryanodine receptor (RyR) channels in SR membrane activate large conductance, calcium-sensitive potassium channels to modulate vascular diameter. In contrast, VSMCs in PAs express functional RyR and BK channels, but under physiological conditions, these channels do not oppose pressure-induced vasoconstriction. Here, we summarize the roles of ryanodine receptors in the parenchymal microvasculature under physiologic and pathologic conditions, and discuss their importance in the control of CBF.
Collapse
Affiliation(s)
- Fabrice Dabertrand
- Department of Pharmacology, College of Medicine, University of Vermont, Burlington, Vermont, USA.
| | | | | |
Collapse
|
41
|
Amador FJ, Stathopulos PB, Enomoto M, Ikura M. Ryanodine receptor calcium release channels: lessons from structure-function studies. FEBS J 2013; 280:5456-70. [PMID: 23413940 DOI: 10.1111/febs.12194] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Revised: 01/24/2013] [Accepted: 02/04/2013] [Indexed: 11/28/2022]
Abstract
Ryanodine receptors (RyRs) are the largest known ion channels. They are Ca(2+) release channels found primarily on the sarcoplasmic reticulum of myocytes. Several hundred mutations in RyRs are associated with skeletal or cardiomyocyte disease in humans. Many of these mutations can now be mapped onto the high resolution structures of individual RyR domains and on full-length tetrameric cryo-electron microscopy structures. A closely related Ca(2+) release channel, the inositol 1,4,5-trisphospate receptor (IP3 R), shows a conserved structural architecture at the N-terminus, suggesting that both channels evolved from an ancestral unicellular RyR/IP3 R. The functional insights provided by recent structural studies for both channels will aid in the development of rationale treatments for a myriad of Ca(2+)-signaled malignancies.
Collapse
Affiliation(s)
- Fernando J Amador
- Ontario Cancer Institute and Department of Medical Biophysics, University of Toronto, Canada
| | | | | | | |
Collapse
|
42
|
Decrock E, De Bock M, Wang N, Gadicherla AK, Bol M, Delvaeye T, Vandenabeele P, Vinken M, Bultynck G, Krysko DV, Leybaert L. IP3, a small molecule with a powerful message. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2013; 1833:1772-86. [PMID: 23291251 DOI: 10.1016/j.bbamcr.2012.12.016] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2012] [Revised: 12/18/2012] [Accepted: 12/19/2012] [Indexed: 12/22/2022]
Abstract
Research conducted over the past two decades has provided convincing evidence that cell death, and more specifically apoptosis, can exceed single cell boundaries and can be strongly influenced by intercellular communication networks. We recently reported that gap junctions (i.e. channels directly connecting the cytoplasm of neighboring cells) composed of connexin43 or connexin26 provide a direct pathway to promote and expand cell death, and that inositol 1,4,5-trisphosphate (IP3) diffusion via these channels is crucial to provoke apoptosis in adjacent healthy cells. However, IP3 itself is not sufficient to induce cell death and additional factors appear to be necessary to create conditions in which IP3 will exert proapoptotic effects. Although IP3-evoked Ca(2+) signaling is known to be required for normal cell survival, it is also actively involved in apoptosis induction and progression. As such, it is evident that an accurate fine-tuning of this signaling mechanism is crucial for normal cell physiology, while a malfunction can lead to cell death. Here, we review the role of IP3 as an intracellular and intercellular cell death messenger, focusing on the endoplasmic reticulum-mitochondrial synapse, followed by a discussion of plausible elements that can convert IP3 from a physiological molecule to a killer substance. Finally, we highlight several pathological conditions in which anomalous intercellular IP3/Ca(2+) signaling might play a role. This article is part of a Special Issue entitled:12th European Symposium on Calcium.
Collapse
Affiliation(s)
- Elke Decrock
- Department of Basic Medical Sciences, Ghent University, Ghent, Belgium
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
43
|
Escobar AL, Perez CG, Reyes ME, Lucero SG, Kornyeyev D, Mejía-Alvarez R, Ramos-Franco J. Role of inositol 1,4,5-trisphosphate in the regulation of ventricular Ca(2+) signaling in intact mouse heart. J Mol Cell Cardiol 2012; 53:768-79. [PMID: 22960455 PMCID: PMC3496050 DOI: 10.1016/j.yjmcc.2012.08.019] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2012] [Revised: 07/25/2012] [Accepted: 08/23/2012] [Indexed: 11/27/2022]
Abstract
Inositol 1,4,5-trisphosphate (InsP(3)R)-mediated Ca(2+) signaling is a major pathway regulating multiple cellular functions in excitable and non-excitable cells. Although InsP(3)-mediated Ca(2+) signaling has been extensively described, its influence on ventricular myocardium activity has not been addressed in contracting hearts at the whole-organ level. In this work, InsP(3)-sensitive intracellular Ca(2+) signals were studied in intact hearts using laser scanning confocal microscopy and pulsed local-field fluorescence microscopy. Intracellular [InsP(3)] was rapidly increased by UV flash photolysis of membrane-permeant caged InsP(3). Our results indicate that the basal [Ca(2+)] increased after the flash photolysis of caged InsP(3) without affecting the action potential (AP)-induced Ca(2+) transients. The amplitude of the basal [Ca(2+)] elevation depended on the intracellular [InsP(3)] reached after the UV flash. Pretreatment with ryanodine failed to abolish the InsP(3)-induced Ca(2+) release (IICR), indicating that this response was not mediated by ryanodine receptors (RyR). Thapsigargin prevented Ca(2+) release from both RyR- and InsP(3)R-containing Ca(2+) stores, suggesting that these pools have similar Ca(2+) reuptake mechanisms. These results were reproduced in acutely isolated cells where photorelease of InsP(3) was able to induce changes in endothelial cells but not in AP-induced transients from cardiomyocytes. Taken together, these results suggest that IICR does not directly regulate cardiac excitation-contraction coupling. To our knowledge, this is the first demonstration of IICR in intact hearts. Consequently, our work provides a reference framework of the spatiotemporal attributes of the IICR under physiological conditions.
Collapse
Affiliation(s)
- Ariel L. Escobar
- School of Engineering, University of California Merced, Merced, CA 95344
| | - Claudia G. Perez
- Department of Molecular Biophysics and Physiology, Rush University Medical Center, Chicago, IL. 60612
| | - Mariano E. Reyes
- School of Engineering, University of California Merced, Merced, CA 95344
| | - Sarah G. Lucero
- Department of Molecular Biophysics and Physiology, Rush University Medical Center, Chicago, IL. 60612
| | - Dmytro Kornyeyev
- School of Engineering, University of California Merced, Merced, CA 95344
| | | | - Josefina Ramos-Franco
- Department of Molecular Biophysics and Physiology, Rush University Medical Center, Chicago, IL. 60612
| |
Collapse
|
44
|
Abstract
Intercellular calcium (Ca(2+)) waves (ICWs) represent the propagation of increases in intracellular Ca(2+) through a syncytium of cells and appear to be a fundamental mechanism for coordinating multicellular responses. ICWs occur in a wide diversity of cells and have been extensively studied in vitro. More recent studies focus on ICWs in vivo. ICWs are triggered by a variety of stimuli and involve the release of Ca(2+) from internal stores. The propagation of ICWs predominately involves cell communication with internal messengers moving via gap junctions or extracellular messengers mediating paracrine signaling. ICWs appear to be important in both normal physiology as well as pathophysiological processes in a variety of organs and tissues including brain, liver, retina, cochlea, and vascular tissue. We review here the mechanisms of initiation and propagation of ICWs, the key intra- and extracellular messengers (inositol 1,4,5-trisphosphate and ATP) mediating ICWs, and the proposed physiological functions of ICWs.
Collapse
Affiliation(s)
- Luc Leybaert
- Department of Basic Medical Sciences, Physiology Group, Faculty of Medicine & Health Sciences, Ghent University, Ghent, Belgium.
| | | |
Collapse
|
45
|
Brown SA, Loew LM. Computational analysis of calcium signaling and membrane electrophysiology in cerebellar Purkinje neurons associated with ataxia. BMC SYSTEMS BIOLOGY 2012; 6:70. [PMID: 22703638 PMCID: PMC3468360 DOI: 10.1186/1752-0509-6-70] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/11/2012] [Accepted: 05/16/2012] [Indexed: 11/10/2022]
Abstract
Background Mutations in the smooth endoplasmic reticulum (sER) calcium channel Inositol Trisphosphate Receptor type 1 (IP3R1) in humans with the motor function coordination disorders Spinocerebellar Ataxia Types 15 and 16 (SCA15/16) and in a corresponding mouse model, the IP3R1delta18/delta18 mice, lead to reduced IP3R1 levels. We posit that increasing IP3R1 sensitivity to IP3 in ataxias with reduced IP3R1 could restore normal calcium response. On the other hand, in mouse models of the human polyglutamine (polyQ) ataxias, SCA2, and SCA3, the primary finding appears to be hyperactive IP3R1-mediated calcium release. It has been suggested that the polyQ SCA1 mice may also show hyperactive IP3R1. Yet, SCA1 mice show downregulated gene expression of IP3R1, Homer, metabotropic glutamate receptor (mGluR), smooth endoplasmic reticulum Ca-ATP-ase (SERCA), calbindin, parvalbumin, and other calcium signaling proteins. Results We create a computational model of pathological alterations in calcium signaling in cerebellar Purkinje neurons to investigate several forms of spinocerebellar ataxia associated with changes in the abundance, sensitivity, or activity of the calcium channel IP3R1. We find that increasing IP3R1 sensitivity to IP3 in computational models of SCA15/16 can restore normal calcium response if IP3R1 abundance is not too low. The studied range in IP3R1 levels reflects variability found in human and mouse ataxic models. Further, the required fold increases in sensitivity are within experimental ranges from experiments that use IP3R1 phosphorylation status to adjust its sensitivity to IP3. Results from our simulations of polyglutamine SCAs suggest that downregulation of some calcium signaling proteins may be partially compensatory. However, the downregulation of calcium buffer proteins observed in the SCA1 mice may contribute to pathology. Finally, our model suggests that the calcium-activated voltage-gated potassium channels may provide an important link between calcium metabolism and membrane potential in Purkinje cell function. Conclusion Thus, we have established an initial platform for computational evaluation and prediction of ataxia pathophysiology. Specifically, the model has been used to investigate SCA15/16, SCA1, SCA2, and SCA3. Results suggest that experimental studies treating mouse models of any of these ataxias with appropriately chosen peptides resembling the C-terminal of IP3R1 could adjust receptor sensitivity, and thereby modulate calcium release and normalize IP3 response. In addition, the model supports the hypothesis of IP3R1 supersensitivity in SCA1.
Collapse
Affiliation(s)
- Sherry-Ann Brown
- Richard D, Berlin Center for Cell Analysis & Modeling, University of Connecticut Health Center, Farmington, CT 06030, USA
| | | |
Collapse
|
46
|
Riera J, Hatanaka R, Ozaki T, Kawashima R. Modeling the spontaneous Ca2+ oscillations in astrocytes: Inconsistencies and usefulness. J Integr Neurosci 2012; 10:439-73. [PMID: 22262535 DOI: 10.1142/s0219635211002877] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2011] [Accepted: 11/09/2011] [Indexed: 12/07/2022] Open
Abstract
Spontaneous calcium (Ca2+) oscillations (SCOs) in astrocytes might be a crucial signaling for the multipurpose role of this type of cell in several brain functions. To interpret experimental data of astrocytic SCOs, which has been largely observed in the last decade, several groups have attempted to accommodate biophysical models that were developed in the past for Ca2+ signaling in other cell types. In most of the cases, only predictive strategies were used to estimate specific parameters of these modified models from actual experiments. In this study, we discuss the most remarkable models used to describe Ca2+ signaling in astrocytes. At the same time, we aim to revise the particulars of applying these models to interpret epifluorescent time series obtained from large regions of interest. Specially, we developed a detailed model for global Ca2+ signaling in the somata of astrocytes. In order to estimate some of the parameters in our model, we propose a deductive reasoning strategy, i.e., a statistical inference method that results from combining a filtering technique and a maximum likelihood principle. By means of computer simulations, we evaluate the accuracy of this estimation's strategy. Finally, we use the new model, in combination with a recent experimental findings by our group, to estimate the degree of cluster coupling inside the soma during the genesis of global Ca2+ events.
Collapse
Affiliation(s)
- J Riera
- Department of Functional Brain Imaging, Institute for Development, Aging and Cancer, Tohoku University, 4-1 Seiryocho, Aobaku, Sendai 980-8575, Japan.
| | | | | | | |
Collapse
|
47
|
Wagner LE, Yule DI. Differential regulation of the InsP₃ receptor type-1 and -2 single channel properties by InsP₃, Ca²⁺ and ATP. J Physiol 2012; 590:3245-59. [PMID: 22547632 DOI: 10.1113/jphysiol.2012.228320] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
An elevation of intracellular Ca2+ levels as a result of InsP3 receptor (InsP3R) activity represents a ubiquitous signalling pathway controlling a wide variety of cellular events. InsP3R activity is tightly controlled by the levels of the primary ligands, InsP3, Ca2+ and ATP. Importantly, InsP3Rs are regulated by Ca2+ i in a biphasic manner. Ca2+ release through all InsP3R family members is also modulated dramatically by ATP, albeit with sub-type-specific properties. To ascertain if a common mechanism can account for ATP and Ca2+ regulation of these InsP3R family members, we examined the effects of [ATP] on the Ca2+ dependency of rat InsP3R-1 (rInsP3R-1) and mouse InsP3R-2 (mInsP3R-2) activity expressed in DT40-3KO cells. We used the on-nucleus patch clamp recording technique with various [ATP], [InsP3] and [Ca2+] in the patch pipette and measured single InsP3R channel activity in stably transfected DT40 cells. Under identical conditions, at saturating [InsP3] and [ATP], the activity of rInsP3R-1 and mInsP3R-2 was essentially identical in terms of single channel conductance, maximal achievable open probability (Po) and the [Ca2+] required for activation and inhibition of activity. However, in contrast to rInsP3R-1 at saturating [InsP3], the activity of mInsP3R-2 was unaffected by [ATP]. At lower [InsP3], ATP had dramatic effects on mInsP3R-2 Po, but unlike the rInsP3R-1, this did not occur by altering the relative Ca2+ dependency, but by simply increasing the maximally achievable Po at a particular [InsP3] and [Ca2+]. [InsP3] did not alter the biphasic regulation of activity by Ca2+ in either rInsP3R-1 or mInsP3R-2. Analysis of the single channel kinetics indicated that Ca2+ and ATP modulate the Po predominately by facilitating extended bursting activity of the channel but the underlying biophysical mechanism appears to be distinct for each receptor. Subtype-specific regulation of InsP3R channel activity probably contributes to the fidelity of Ca2+ signalling in cells expressing these receptor subtypes.
Collapse
Affiliation(s)
- Larry E Wagner
- Department of Pharmacology, School of Medicine and Dentistry, University of Rochester Medical Center, Rochester, NY, USA
| | | |
Collapse
|
48
|
De Bock M, Wang N, Bol M, Decrock E, Ponsaerts R, Bultynck G, Dupont G, Leybaert L. Connexin 43 hemichannels contribute to cytoplasmic Ca2+ oscillations by providing a bimodal Ca2+-dependent Ca2+ entry pathway. J Biol Chem 2012; 287:12250-66. [PMID: 22351781 PMCID: PMC3320976 DOI: 10.1074/jbc.m111.299610] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2011] [Revised: 02/16/2012] [Indexed: 11/06/2022] Open
Abstract
Many cellular functions are driven by changes in the intracellular Ca(2+) concentration ([Ca(2+)](i)) that are highly organized in time and space. Ca(2+) oscillations are particularly important in this respect and are based on positive and negative [Ca(2+)](i) feedback on inositol 1,4,5-trisphosphate receptors (InsP(3)Rs). Connexin hemichannels are Ca(2+)-permeable plasma membrane channels that are also controlled by [Ca(2+)](i). We aimed to investigate how hemichannels may contribute to Ca(2+) oscillations. Madin-Darby canine kidney cells expressing connexin-32 (Cx32) and Cx43 were exposed to bradykinin (BK) or ATP to induce Ca(2+) oscillations. BK-induced oscillations were rapidly (minutes) and reversibly inhibited by the connexin-mimetic peptides (32)Gap27/(43)Gap26, whereas ATP-induced oscillations were unaffected. Furthermore, these peptides inhibited the BK-triggered release of calcein, a hemichannel-permeable dye. BK-induced oscillations, but not those induced by ATP, were dependent on extracellular Ca(2+). Alleviating the negative feedback of [Ca(2+)](i) on InsP(3)Rs using cytochrome c inhibited BK- and ATP-induced oscillations. Cx32 and Cx43 hemichannels are activated by <500 nm [Ca(2+)](i) but inhibited by higher concentrations and CT9 peptide (last 9 amino acids of the Cx43 C terminus) removes this high [Ca(2+)](i) inhibition. Unlike interfering with the bell-shaped dependence of InsP(3)Rs to [Ca(2+)](i), CT9 peptide prevented BK-induced oscillations but not those triggered by ATP. Collectively, these data indicate that connexin hemichannels contribute to BK-induced oscillations by allowing Ca(2+) entry during the rising phase of the Ca(2+) spikes and by providing an OFF mechanism during the falling phase of the spikes. Hemichannels were not sufficient to ignite oscillations by themselves; however, their contribution was crucial as hemichannel inhibition stopped the oscillations.
Collapse
Affiliation(s)
- Marijke De Bock
- From the Department of Basic Medical Sciences, Physiology Group, Ghent University 9000 Ghent, Belgium
| | - Nan Wang
- From the Department of Basic Medical Sciences, Physiology Group, Ghent University 9000 Ghent, Belgium
| | - Melissa Bol
- From the Department of Basic Medical Sciences, Physiology Group, Ghent University 9000 Ghent, Belgium
| | - Elke Decrock
- From the Department of Basic Medical Sciences, Physiology Group, Ghent University 9000 Ghent, Belgium
| | - Raf Ponsaerts
- Department of Molecular Cell Biology, Laboratory of Molecular and Cellular Signaling, KULeuven, 3000 Leuven, Belgium, and
| | - Geert Bultynck
- Department of Molecular Cell Biology, Laboratory of Molecular and Cellular Signaling, KULeuven, 3000 Leuven, Belgium, and
| | - Geneviève Dupont
- Theoretical Chronobiology Unit, Université Libre de Bruxelles, 1050 Brussels, Belgium
| | - Luc Leybaert
- From the Department of Basic Medical Sciences, Physiology Group, Ghent University 9000 Ghent, Belgium
| |
Collapse
|
49
|
Narayanan D, Adebiyi A, Jaggar JH. Inositol trisphosphate receptors in smooth muscle cells. Am J Physiol Heart Circ Physiol 2012; 302:H2190-210. [PMID: 22447942 DOI: 10.1152/ajpheart.01146.2011] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Inositol 1,4,5-trisphosphate receptors (IP(3)Rs) are a family of tetrameric intracellular calcium (Ca(2+)) release channels that are located on the sarcoplasmic reticulum (SR) membrane of virtually all mammalian cell types, including smooth muscle cells (SMC). Here, we have reviewed literature investigating IP(3)R expression, cellular localization, tissue distribution, activity regulation, communication with ion channels and organelles, generation of Ca(2+) signals, modulation of physiological functions, and alterations in pathologies in SMCs. Three IP(3)R isoforms have been identified, with relative expression and cellular localization of each contributing to signaling differences in diverse SMC types. Several endogenous ligands, kinases, proteins, and other modulators control SMC IP(3)R channel activity. SMC IP(3)Rs communicate with nearby ryanodine-sensitive Ca(2+) channels and mitochondria to influence SR Ca(2+) release and reactive oxygen species generation. IP(3)R-mediated Ca(2+) release can stimulate plasma membrane-localized channels, including transient receptor potential (TRP) channels and store-operated Ca(2+) channels. SMC IP(3)Rs also signal to other proteins via SR Ca(2+) release-independent mechanisms through physical coupling to TRP channels and local communication with large-conductance Ca(2+)-activated potassium channels. IP(3)R-mediated Ca(2+) release generates a wide variety of intracellular Ca(2+) signals, which vary with respect to frequency, amplitude, spatial, and temporal properties. IP(3)R signaling controls multiple SMC functions, including contraction, gene expression, migration, and proliferation. IP(3)R expression and cellular signaling are altered in several SMC diseases, notably asthma, atherosclerosis, diabetes, and hypertension. In summary, IP(3)R-mediated pathways control diverse SMC physiological functions, with pathological alterations in IP(3)R signaling contributing to disease.
Collapse
Affiliation(s)
- Damodaran Narayanan
- Department of Physiology, University of Tennessee Health Science Center, Memphis, 38163, USA
| | | | | |
Collapse
|
50
|
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.
Collapse
Affiliation(s)
- Benoit Chaloux
- Department of Pharmacology, Faculty of Medicine and Health Sciences, University of Sherbrooke, Sherbrooke, Quebec, Canada
| | | | | |
Collapse
|