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Fameli N, van Breemen C, Groschner K. Nanojunctions: Specificity of Ca 2+ signaling requires nano-scale architecture of intracellular membrane contact sites. Cell Calcium 2024; 117:102837. [PMID: 38011822 DOI: 10.1016/j.ceca.2023.102837] [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: 07/25/2023] [Revised: 10/31/2023] [Accepted: 11/17/2023] [Indexed: 11/29/2023]
Abstract
Spatio-temporal definition of Ca2+ signals involves the assembly of signaling complexes within the nano-architecture of contact sites between the sarco/endoplasmic reticulum (SR/ER) and the plasma membrane (PM). While the requirement of precise spatial assembly and positioning of the junctional signaling elements is well documented, the role of the nano-scale membrane architecture itself, as an ion-reflecting confinement of the signalling unit, remains as yet elusive. Utilizing the Na+/Ca2+ Exchanger-1 / SR/ER Ca2+ ATPase-2-mediated ER Ca2+ refilling process as a junctional signalling paradigm, we provide here the first evidence for an indispensable cellular function of the junctional membrane architecture. Our stochastic modeling approach demonstrates that junctional ER Ca2+ refilling operates exclusively at nano-scale membrane spacing, with a strong inverse relationship between junctional width and signaling efficiency. Our model predicts a breakdown of junctional Ca2+ signaling with loss of reflecting membrane confinement. In addition we consider interactions between Ca2+ and the phospholipid membrane surface, which may support interfacial Ca2+ transport and promote receptor targeting. Alterations in the molecular and nano-scale membrane organization at organelle-PM contacts are suggested as a new concept in pathophysiology.
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Affiliation(s)
| | - Cornelis van Breemen
- Department of Anesthesiology, Pharmacology, and Therapeutics, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Klaus Groschner
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Medical University of Graz, Graz, Austria.
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2
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The Molecular Heterogeneity of Store-Operated Ca 2+ Entry in Vascular Endothelial Cells: The Different roles of Orai1 and TRPC1/TRPC4 Channels in the Transition from Ca 2+-Selective to Non-Selective Cation Currents. Int J Mol Sci 2023; 24:ijms24043259. [PMID: 36834672 PMCID: PMC9967124 DOI: 10.3390/ijms24043259] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 01/31/2023] [Accepted: 02/03/2023] [Indexed: 02/11/2023] Open
Abstract
Store-operated Ca2+ entry (SOCE) is activated in response to the inositol-1,4,5-trisphosphate (InsP3)-dependent depletion of the endoplasmic reticulum (ER) Ca2+ store and represents a ubiquitous mode of Ca2+ influx. In vascular endothelial cells, SOCE regulates a plethora of functions that maintain cardiovascular homeostasis, such as angiogenesis, vascular tone, vascular permeability, platelet aggregation, and monocyte adhesion. The molecular mechanisms responsible for SOCE activation in vascular endothelial cells have engendered a long-lasting controversy. Traditionally, it has been assumed that the endothelial SOCE is mediated by two distinct ion channel signalplexes, i.e., STIM1/Orai1 and STIM1/Transient Receptor Potential Canonical 1(TRPC1)/TRPC4. However, recent evidence has shown that Orai1 can assemble with TRPC1 and TRPC4 to form a non-selective cation channel with intermediate electrophysiological features. Herein, we aim at bringing order to the distinct mechanisms that mediate endothelial SOCE in the vascular tree from multiple species (e.g., human, mouse, rat, and bovine). We propose that three distinct currents can mediate SOCE in vascular endothelial cells: (1) the Ca2+-selective Ca2+-release activated Ca2+ current (ICRAC), which is mediated by STIM1 and Orai1; (2) the store-operated non-selective current (ISOC), which is mediated by STIM1, TRPC1, and TRPC4; and (3) the moderately Ca2+-selective, ICRAC-like current, which is mediated by STIM1, TRPC1, TRPC4, and Orai1.
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3
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Klapczyńska K, Aleksandrowicz M, Koźniewska E. Role of the endothelial reverse mode sodium-calcium exchanger in the dilation of the rat middle cerebral artery during hypoosmotic hyponatremia. Pflugers Arch 2023; 475:381-390. [PMID: 36394650 PMCID: PMC9908729 DOI: 10.1007/s00424-022-02770-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 10/22/2022] [Accepted: 11/04/2022] [Indexed: 11/18/2022]
Abstract
A decrease in serum sodium ion concentration below 135 mmol L-1 is usually accompanied by a decrease in plasma osmolality (hypoosmotic hyponatremia) and leads to the disorder of intracranial homeostasis mainly due to cellular swelling. Recently, using an in vitro model of hypoosmotic hyponatremia, we have found that a decrease in sodium ion concentration in the perfusate to 121 mmol L-1 relaxes the isolated rat middle cerebral artery (MCA). The aim of the present study was to explore the mechanism responsible for this relaxation. Isolated, pressurized, and perfused MCAs placed in a vessel chamber were subjected to a decrease in sodium ion concentration to 121 mmol L-1. Changes in the diameter of the vessels were monitored with a video camera. The removal of the endothelium and inhibition of nitric oxide-dependent signaling or the reverse mode sodium-calcium exchanger (NCX) were used to study the mechanism of the dilation of the vessel during hyponatremia. The dilation of the MCA (19 ± 5%, p < 0.005) in a low-sodium buffer was absent after removal of the endothelium or administration of the inhibitor of the reverse mode of sodium-calcium exchange and was reversed to constriction after the inhibition of nitric oxide (NO)/cGMP signaling. The dilation of the middle cerebral artery of the rat in a 121 mmol L-1 Na+ buffer depends on NO signaling and reverse mode of sodium-calcium exchange. These results suggest that constriction of large cerebral arteries with impaired NO-dependent signaling may be observed in response to hypoosmotic hyponatremia.
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Affiliation(s)
- Katarzyna Klapczyńska
- grid.79757.3b0000 0000 8780 7659Institute of Physical Culture Sciences, Faculty of Health and Physical Education, University of Szczecin, Szczecin, Poland
| | - Marta Aleksandrowicz
- grid.413454.30000 0001 1958 0162Laboratory of Experimental and Clinical Neurosurgery, Mossakowski Medical Research Institute Polish Academy of Sciences, Warsaw, Poland
| | - Ewa Koźniewska
- Laboratory of Experimental and Clinical Neurosurgery, Mossakowski Medical Research Institute Polish Academy of Sciences, Warsaw, Poland.
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Curcic S, Erkan-Candag H, Pilic J, Malli R, Wiedner P, Tiapko O, Groschner K. TRPC3 governs the spatiotemporal organization of cellular Ca 2+ signatures by functional coupling to IP 3 receptors. Cell Calcium 2022; 108:102670. [PMID: 36375273 DOI: 10.1016/j.ceca.2022.102670] [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: 09/08/2022] [Revised: 10/12/2022] [Accepted: 10/31/2022] [Indexed: 11/06/2022]
Abstract
Communication between TRPC channels and IP3 receptors (IP3R) is considered pivotal in the generation of spatiotemporal Ca2+signaling patterns. Here we revisited the role of TRPC3-IP3R coupling for local Ca2+ signaling within TRPC3-harbouring micro/nanodomains using R-GECO as a reporter, fused to the channel´s C-terminus. Cytoplasmic Ca2+ changes at TRPC3 originated from both the entry of Ca2+ through the TRPC channel and Ca2+ mobilization via IP3R. Local Ca2+ changes at TRPC3 channels expressed in HEK293 cells were predominantly biphasic with IP3R-dependent initial Ca2+ transients, while exclusively monophasic signals were recorded when all three IP3R isoforms were lacking. Abrogation of Ca2+ entry through TRPC3 by point mutations, which impair Ca2+ permeability (E630Q), cation permeation (E630K), or DAG sensitivity (G652A), promoted microdomain Ca2+ oscillations. Ca2+ signals at E630Q, E630K, and G652A channels featured initial Ca2+ transients along with oscillatory activity. Similarly, when extracellular Ca2+ was omitted, IP3R-mediated Ca2+ transients and Ca2+ oscillations were promoted at the cytoplasmic face of wild-type TRPC3 channels. By contrast, oscillations, as well as initial Ca2+ transients, were virtually lacking, when the TRPC3 channels were sensitized by preexposure to low-level PLC activity. TIRF imaging provided evidence for dynamic colocalization of TRPC3 and IP3R. We suggest that TRPC3-mediated Ca2+ entry controls IP3R activity at ER-PM junctions to determine Ca2+ signaling signatures and enable specificity of downstream signaling.
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Affiliation(s)
- Sanja Curcic
- Gottfried-Schatz Research Center (Biophysics), Medical University of Graz, Austria.
| | - Hazel Erkan-Candag
- Gottfried-Schatz Research Center (Biophysics), Medical University of Graz, Austria
| | - Johannes Pilic
- Gottfried-Schatz Research Center (Molecular Biology and Biochemistry), Medical University of Graz, Austria
| | - Roland Malli
- Gottfried-Schatz Research Center (Molecular Biology and Biochemistry), Medical University of Graz, Austria
| | - Patrick Wiedner
- Gottfried-Schatz Research Center (Biophysics), Medical University of Graz, Austria
| | - Oleksandra Tiapko
- Gottfried-Schatz Research Center (Biophysics), Medical University of Graz, Austria
| | - Klaus Groschner
- Gottfried-Schatz Research Center (Biophysics), Medical University of Graz, Austria.
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5
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Piccialli I, Ciccone R, Secondo A, Boscia F, Tedeschi V, de Rosa V, Cepparulo P, Annunziato L, Pannaccione A. The Na +/Ca 2+ Exchanger 3 Is Functionally Coupled With the Na V1.6 Voltage-Gated Channel and Promotes an Endoplasmic Reticulum Ca 2+ Refilling in a Transgenic Model of Alzheimer's Disease. Front Pharmacol 2021; 12:775271. [PMID: 34955845 PMCID: PMC8692738 DOI: 10.3389/fphar.2021.775271] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 11/22/2021] [Indexed: 01/15/2023] Open
Abstract
The remodelling of neuronal ionic homeostasis by altered channels and transporters is a critical feature of the Alzheimer's disease (AD) pathogenesis. Different reports converge on the concept that the Na+/Ca2+ exchanger (NCX), as one of the main regulators of Na+ and Ca2+ concentrations and signalling, could exert a neuroprotective role in AD. The activity of NCX has been found to be increased in AD brains, where it seemed to correlate with an increased neuronal survival. Moreover, the enhancement of the NCX3 currents (INCX) in primary neurons treated with the neurotoxic amyloid β 1-42 (Aβ1-42) oligomers prevented the endoplasmic reticulum (ER) stress and neuronal death. The present study has been designed to investigate any possible modulation of the INCX, the functional interaction between NCX and the NaV1.6 channel, and their impact on the Ca2+ homeostasis in a transgenic in vitro model of AD, the primary hippocampal neurons from the Tg2576 mouse, which overproduce the Aβ1-42 peptide. Electrophysiological studies, carried in the presence of siRNA and the isoform-selective NCX inhibitor KB-R7943, showed that the activity of a specific NCX isoform, NCX3, was upregulated in its reverse, Ca2+ influx mode of operation in the Tg2576 neurons. The enhanced NCX activity contributed, in turn, to increase the ER Ca2+ content, without affecting the cytosolic Ca2+ concentrations of the Tg2576 neurons. Interestingly, our experiments have also uncovered a functional coupling between NCX3 and the voltage-gated NaV1.6 channels. In particular, the increased NaV1.6 currents appeared to be responsible for the upregulation of the reverse mode of NCX3, since both TTX and the Streptomyces griseolus antibiotic anisomycin, by reducing the NaV1.6 currents, counteracted the increase of the INCX in the Tg2576 neurons. In agreement, our immunofluorescence analyses revealed that the NCX3/NaV1.6 co-expression was increased in the Tg2576 hippocampal neurons in comparison with the WT neurons. Collectively, these findings indicate that NCX3 might intervene in the Ca2+ remodelling occurring in the Tg2576 primary neurons thus emerging as a molecular target with a neuroprotective potential, and provide a new outcome of the NaV1.6 upregulation related to the modulation of the intracellular Ca2+ concentrations in AD neurons.
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Affiliation(s)
- Ilaria Piccialli
- Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, Federico II University of Naples, Naples, Italy
| | - Roselia Ciccone
- Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, Federico II University of Naples, Naples, Italy
| | - Agnese Secondo
- Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, Federico II University of Naples, Naples, Italy
| | - Francesca Boscia
- Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, Federico II University of Naples, Naples, Italy
| | - Valentina Tedeschi
- Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, Federico II University of Naples, Naples, Italy
| | - Valeria de Rosa
- Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, Federico II University of Naples, Naples, Italy
| | - Pasquale Cepparulo
- Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, Federico II University of Naples, Naples, Italy
| | | | - Anna Pannaccione
- Division of Pharmacology, Department of Neuroscience, Reproductive and Dentistry Sciences, School of Medicine, Federico II University of Naples, Naples, Italy
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Negri S, Faris P, Moccia F. Reactive Oxygen Species and Endothelial Ca 2+ Signaling: Brothers in Arms or Partners in Crime? Int J Mol Sci 2021; 22:ijms22189821. [PMID: 34575985 PMCID: PMC8465413 DOI: 10.3390/ijms22189821] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 09/08/2021] [Accepted: 09/08/2021] [Indexed: 12/20/2022] Open
Abstract
An increase in intracellular Ca2+ concentration ([Ca2+]i) controls virtually all endothelial cell functions and is, therefore, crucial to maintain cardiovascular homeostasis. An aberrant elevation in endothelial can indeed lead to severe cardiovascular disorders. Likewise, moderate amounts of reactive oxygen species (ROS) induce intracellular Ca2+ signals to regulate vascular functions, while excessive ROS production may exploit dysregulated Ca2+ dynamics to induce endothelial injury. Herein, we survey how ROS induce endothelial Ca2+ signals to regulate vascular functions and, vice versa, how aberrant ROS generation may exploit the Ca2+ handling machinery to promote endothelial dysfunction. ROS elicit endothelial Ca2+ signals by regulating inositol-1,4,5-trisphosphate receptors, sarco-endoplasmic reticulum Ca2+-ATPase 2B, two-pore channels, store-operated Ca2+ entry (SOCE), and multiple isoforms of transient receptor potential (TRP) channels. ROS-induced endothelial Ca2+ signals regulate endothelial permeability, angiogenesis, and generation of vasorelaxing mediators and can be exploited to induce therapeutic angiogenesis, rescue neurovascular coupling, and induce cancer regression. However, an increase in endothelial [Ca2+]i induced by aberrant ROS formation may result in endothelial dysfunction, inflammatory diseases, metabolic disorders, and pulmonary artery hypertension. This information could pave the way to design alternative treatments to interfere with the life-threatening interconnection between endothelial ROS and Ca2+ signaling under multiple pathological conditions.
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7
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Kaimachnikov NP, Kotova PD, Kochkina EN, Rogachevskaja OA, Khokhlov AA, Bystrova MF, Kolesnikov SS. Modeling of Ca2+ transients initiated by GPCR agonists in mesenchymal stromal cells. BBA ADVANCES 2021; 1:100012. [PMID: 37082025 PMCID: PMC10074909 DOI: 10.1016/j.bbadva.2021.100012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 04/05/2021] [Accepted: 04/11/2021] [Indexed: 10/21/2022] Open
Abstract
The integrative study that included experimentation and mathematical modeling was carried out to analyze dynamic aspects of transient Ca2+ signaling induced by brief pulses of GPCR agonists in mesenchymal stromal cells from the human adipose tissue (AD-MSCs). The experimental findings argued for IP3/Ca2+-regulated Ca2+ release via IP3 receptors (IP3Rs) as a key mechanism mediating agonist-dependent Ca2+ transients. The consistent signaling circuit was proposed to formalize coupling of agonist binding to Ca2+ mobilization for mathematical modeling. The model properly simulated the basic phenomenology of agonist transduction in AD-MSCs, which mostly produced single Ca2+ spikes upon brief stimulation. The spike-like responses were almost invariantly shaped at different agonist doses above a threshold, while response lag markedly decreased with stimulus strength. In AD-MSCs, agonists and IP3 uncaging elicited similar Ca2+ transients but IP3 pulses released Ca2+ without pronounced delay. This suggested that IP3 production was rate-limiting in agonist transduction. In a subpopulation of AD-MSCs, brief agonist pulses elicited Ca2+ bursts crowned by damped oscillations. With properly adjusted parameters of IP3R inhibition by cytosolic Ca2+, the model reproduced such oscillatory Ca2+ responses as well. GEM-GECO1 and R-CEPIA1er, the genetically encoded sensors of cytosolic and reticular Ca2+, respectively, were co-expressed in HEK-293 cells that also responded to agonists in an "all-or-nothing" manner. The experimentally observed Ca2+ signals triggered by ACh in both compartments were properly simulated with the suggested signaling circuit. Thus, the performed modeling of the transduction process provides sufficient theoretical basis for deeper interpretation of experimental findings on agonist-induced Ca2+ signaling in AD-MSCs.
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Faris P, Ferulli F, Vismara M, Tanzi M, Negri S, Rumolo A, Lefkimmiatis K, Maestri M, Shekha M, Pedrazzoli P, Guidetti GF, Montagna D, Moccia F. Hydrogen Sulfide-Evoked Intracellular Ca 2+ Signals in Primary Cultures of Metastatic Colorectal Cancer Cells. Cancers (Basel) 2020; 12:cancers12113338. [PMID: 33187307 PMCID: PMC7696676 DOI: 10.3390/cancers12113338] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 11/05/2020] [Accepted: 11/06/2020] [Indexed: 02/07/2023] Open
Abstract
Simple Summary Colorectal cancer (CRC) is the most common type of gastrointestinal cancer and the third most predominant cancer in the world. CRC is potentially curable with surgical resection of the primary tumor. The clinical problem of colorectal cancer, however, is the spread and outgrowth of metastases, which are difficult to eradicate and lead to a patient’s death. The failure of conventional treatment to significantly improved outcomes in mCRC has prompted the search for alternative molecular targets with the goal of ameliorating the prognosis of these patients. The present investigation revealed that exogenous delivery of hydrogen sulfide (H2S) suppresses proliferation in metastatic colorectal cancer cells by inducing an increase in intracellular Ca2+ concentration. H2S was effective on metastatic, but not normal, cells. Therefore, we propose that exogenous administration of H2S to patients affected by metastatic colorectal carcinoma could represent a promising therapeutic alternative. Abstract Exogenous administration of hydrogen sulfide (H2S) is emerging as an alternative anticancer treatment. H2S-releasing compounds have been shown to exert a strong anticancer effect by suppressing proliferation and/or inducing apoptosis in several cancer cell types, including colorectal carcinoma (CRC). The mechanism whereby exogenous H2S affects CRC cell proliferation is yet to be clearly elucidated, but it could involve an increase in intracellular Ca2+ concentration ([Ca2+]i). Herein, we sought to assess for the first time whether (and how) sodium hydrosulfide (NaHS), one of the most widely employed H2S donors, induced intracellular Ca2+ signals in primary cultures of human metastatic CRC (mCRC) cells. We provided the evidence that NaHS induced extracellular Ca2+ entry in mCRC cells by activating the Ca2+-permeable channel Transient Receptor Potential Vanilloid 1 (TRPV1) followed by the Na+-dependent recruitment of the reverse-mode of the Na+/Ca2+ (NCX) exchanger. In agreement with these observations, TRPV1 protein was expressed and capsaicin, a selective TRPV1 agonist, induced Ca2+ influx by engaging both TRPV1 and NCX in mCRC cells. Finally, NaHS reduced mCRC cell proliferation, but did not promote apoptosis or aberrant mitochondrial depolarization. These data support the notion that exogenous administration of H2S may prevent mCRC cell proliferation through an increase in [Ca2+]i, which is triggered by TRPV1.
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Affiliation(s)
- Pawan Faris
- Laboratory of General Physiology, Department of Biology and Biotechnology “L. Spallanzani”, University of Pavia, 27100 Pavia, Italy; (P.F.); (S.N.)
- Department of Biology, Cihan University-Erbil, 44001 Erbil, Iraq
| | - Federica Ferulli
- Laboratory of Immunology Transplantation, Foundation IRCCS Policlinico San Matteo, 27100 Pavia, Italy; (F.F.); (M.T.); (A.R.)
| | - Mauro Vismara
- Laboratory of Biochemistry, Department of Biology and Biotechnology “L. Spallanzani”, University of Pavia, 27100 Pavia, Italy; (M.V.); (G.F.G.)
| | - Matteo Tanzi
- Laboratory of Immunology Transplantation, Foundation IRCCS Policlinico San Matteo, 27100 Pavia, Italy; (F.F.); (M.T.); (A.R.)
| | - Sharon Negri
- Laboratory of General Physiology, Department of Biology and Biotechnology “L. Spallanzani”, University of Pavia, 27100 Pavia, Italy; (P.F.); (S.N.)
| | - Agnese Rumolo
- Laboratory of Immunology Transplantation, Foundation IRCCS Policlinico San Matteo, 27100 Pavia, Italy; (F.F.); (M.T.); (A.R.)
| | - Kostantinos Lefkimmiatis
- Department of Molecular Medicine, University of Pavia, 27100 Pavia, Italy;
- Veneto Institute of Molecular Medicine, Foundation for Advanced Biomedical Research, 35131 Padua, Italy
| | - Marcello Maestri
- Medical Surgery, Foundation IRCCS Policlinico San Matteo, 27100 Pavia, Italy;
| | - Mudhir Shekha
- Faculty of Science, Department of Medical Analysis, Tishk International University-Erbil, 44001 Erbil, Iraq;
| | - Paolo Pedrazzoli
- Medical Oncology, Foundation IRCCS Policlinico San Matteo, 27100 Pavia, Italy;
| | - Gianni Francesco Guidetti
- Laboratory of Biochemistry, Department of Biology and Biotechnology “L. Spallanzani”, University of Pavia, 27100 Pavia, Italy; (M.V.); (G.F.G.)
| | - Daniela Montagna
- Laboratory of Immunology Transplantation, Foundation IRCCS Policlinico San Matteo, 27100 Pavia, Italy; (F.F.); (M.T.); (A.R.)
- Diagnostic and Pediatric, Department of Sciences Clinic-Surgical, University of Pavia, 27100 Pavia, Italy
- Correspondence: (D.M.); (F.M.); Tel.: +39-382-987-619 (F.M.)
| | - Francesco Moccia
- Laboratory of General Physiology, Department of Biology and Biotechnology “L. Spallanzani”, University of Pavia, 27100 Pavia, Italy; (P.F.); (S.N.)
- Correspondence: (D.M.); (F.M.); Tel.: +39-382-987-619 (F.M.)
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9
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Resveratrol Stimulates the Na+–Ca2+ Exchanger on the Plasma Membrane to Reduce Cytosolic Ca2+ in Rat Aortic Smooth Muscle Cells. J Cardiovasc Pharmacol 2020; 76:610-616. [DOI: 10.1097/fjc.0000000000000897] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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10
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Anand P, Harper AGS. Human platelets use a cytosolic Ca 2+ nanodomain to activate Ca 2+-dependent shape change independently of platelet aggregation. Cell Calcium 2020; 90:102248. [PMID: 32629299 DOI: 10.1016/j.ceca.2020.102248] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 06/14/2020] [Accepted: 06/22/2020] [Indexed: 10/24/2022]
Abstract
Human platelets use a rise in cytosolic Ca2+ concentration to activate all stages of thrombus formation, however, how they are able to decode cytosolic Ca2+ signals to trigger each of these independently is unknown. Other cells create local Ca2+ signals to activate Ca2+-sensitive effectors specifically localised to these subcellular regions. However, no previous study has demonstrated that agonist-stimulated human platelets can generate a local cytosolic Ca2+ signal. Platelets possess a structure called the membrane complex (MC) where the main intracellular calcium store, the dense tubular system (DTS), is coupled tightly to an invaginated portion of the plasma membrane called the open canalicular system (OCS). Here we hypothesised that human platelets use a Ca2+ nanodomain created within the MC to control the earliest phases of platelet activation. Dimethyl-BAPTA-loaded human platelets were stimulated with thrombin in the absence of extracellular Ca2+ to isolate a cytosolic Ca2+ nanodomain created by Ca2+ release from the DTS. In the absence of any detectable rise in global cytosolic Ca2+ concentration, thrombin stimulation triggered Na+/Ca2+ exchanger (NCX)-dependent Ca2+ removal into the extracellular space, as well as Ca2+-dependent shape change in the absence of platelet aggregation. The NCX-mediated Ca2+ removal was dependent on the normal localisation of the DTS, and immunofluorescent staining of NCX3 demonstrated its localisation to the OCS, consistent with this Ca2+ nanodomain being formed within the MC. These results demonstrated that human platelets possess a functional Ca2+ nanodomain contained within the MC that can control shape change independently of platelet aggregation.
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Affiliation(s)
- Peterson Anand
- School of Pharmacy and Bioengineering, Keele University, Guy Hilton Research Centre, Thornburrow Drive, Hartshill, Stoke-on-Trent, ST4 7QB, UK
| | - Alan G S Harper
- School of Medicine, Keele University, Keele, Staffordshire, ST5 5BG, UK.
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11
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Berra-Romani R, Guzmán-Silva A, Vargaz-Guadarrama A, Flores-Alonso JC, Alonso-Romero J, Treviño S, Sánchez-Gómez J, Coyotl-Santiago N, García-Carrasco M, Moccia F. Type 2 Diabetes Alters Intracellular Ca 2+ Handling in Native Endothelium of Excised Rat Aorta. Int J Mol Sci 2019; 21:ijms21010250. [PMID: 31905880 PMCID: PMC6982087 DOI: 10.3390/ijms21010250] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 12/24/2019] [Accepted: 12/25/2019] [Indexed: 02/03/2023] Open
Abstract
An increase in intracellular Ca2+ concentration ([Ca2+]i) plays a key role in controlling endothelial functions; however, it is still unclear whether endothelial Ca2+ handling is altered by type 2 diabetes mellitus, which results in severe endothelial dysfunction. Herein, we analyzed for the first time the Ca2+ response to the physiological autacoid ATP in native aortic endothelium of obese Zucker diabetic fatty (OZDF) rats and their lean controls, which are termed LZDF rats. By loading the endothelial monolayer with the Ca2+-sensitive fluorophore, Fura-2/AM, we found that the endothelial Ca2+ response to 20 µM and 300 µM ATP exhibited a higher plateau, a larger area under the curve and prolonged duration in OZDF rats. The “Ca2+ add-back” protocol revealed no difference in the inositol-1,4,5-trisphosphate-releasable endoplasmic reticulum (ER) Ca2+ pool, while store-operated Ca2+ entry was surprisingly down-regulated in OZDF aortae. Pharmacological manipulation disclosed that sarco-endoplasmic reticulum Ca2+-ATPase (SERCA) activity was down-regulated by reactive oxygen species in native aortic endothelium of OZDF rats, thereby exaggerating the Ca2+ response to high agonist concentrations. These findings shed new light on the mechanisms by which type 2 diabetes mellitus may cause endothelial dysfunction by remodeling the intracellular Ca2+ toolkit.
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Affiliation(s)
- Roberto Berra-Romani
- Laboratory of Cardiovascular Physiology, Biomedicine School, Faculty of Medicine, Benemérita Universidad Autónoma de Puebla, Puebla 72410, Mexico; (A.G.-S.); (J.A.-R.); (N.C.-S.)
- Correspondence: (R.B.-R.); (F.M.)
| | - Alejandro Guzmán-Silva
- Laboratory of Cardiovascular Physiology, Biomedicine School, Faculty of Medicine, Benemérita Universidad Autónoma de Puebla, Puebla 72410, Mexico; (A.G.-S.); (J.A.-R.); (N.C.-S.)
| | - Ajelet Vargaz-Guadarrama
- Faculty of Medicine, Benemérita Universidad Autónoma de Puebla, Puebla 72410, Mexico; (A.V.-G.); (J.S.-G.); (M.G.-C.)
| | - Juan Carlos Flores-Alonso
- Centro de Investigación Biomédica de Oriente, Instituto Mexicano del Seguro Social, Puebla 74360, Mexico;
| | - José Alonso-Romero
- Laboratory of Cardiovascular Physiology, Biomedicine School, Faculty of Medicine, Benemérita Universidad Autónoma de Puebla, Puebla 72410, Mexico; (A.G.-S.); (J.A.-R.); (N.C.-S.)
| | - Samuel Treviño
- Facultad de Ciencias Químicas, Benemérita Universidad Autónoma de Puebla, Puebla 72540, Mexico;
| | - Josué Sánchez-Gómez
- Faculty of Medicine, Benemérita Universidad Autónoma de Puebla, Puebla 72410, Mexico; (A.V.-G.); (J.S.-G.); (M.G.-C.)
| | - Nayeli Coyotl-Santiago
- Laboratory of Cardiovascular Physiology, Biomedicine School, Faculty of Medicine, Benemérita Universidad Autónoma de Puebla, Puebla 72410, Mexico; (A.G.-S.); (J.A.-R.); (N.C.-S.)
| | - Mario García-Carrasco
- Faculty of Medicine, Benemérita Universidad Autónoma de Puebla, Puebla 72410, Mexico; (A.V.-G.); (J.S.-G.); (M.G.-C.)
| | - Francesco Moccia
- Laboratory of General Physiology, Department of Biology and Biotechnology “Lazzaro Spallanzani”, University of Pavia, 27100 Pavia, Italy
- Correspondence: (R.B.-R.); (F.M.)
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12
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Agonist-evoked endothelial Ca 2+ signalling microdomains. Curr Opin Pharmacol 2019; 45:8-15. [PMID: 30986569 DOI: 10.1016/j.coph.2019.03.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 03/03/2019] [Accepted: 03/15/2019] [Indexed: 01/14/2023]
Abstract
Localized, oscillating Ca2+ signals have been identified in discrete microdomains of vascular endothelial cells. At myoendothelial contacts (between endothelial and smooth muscle cells), both endothelial Ca2+ pulsars (IP3-mediated release of intracellular Ca2+) and Ca2+ sparklets (extracellular Ca2+ entry via TRP channels) contribute to endothelium-dependent hyperpolarization of smooth muscle, vasodilation, and feedback control of vasoconstriction. Ca2+ sparklets occurring at close-contact domains between endothelial cells are possibly involved in conducted hyperpolarization and spreading vasodilation in arterial networks. This review summarizes these Ca2+ signalling phenomena, examines the proposed mechanisms leading to their generation by G-protein-coupled receptor agonists, and explores the proposed physiological roles of these localized and specialized Ca2+ signals.
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Behringer EJ, Hakim MA. Functional Interaction among K Ca and TRP Channels for Cardiovascular Physiology: Modern Perspectives on Aging and Chronic Disease. Int J Mol Sci 2019; 20:ijms20061380. [PMID: 30893836 PMCID: PMC6471369 DOI: 10.3390/ijms20061380] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Revised: 03/07/2019] [Accepted: 03/15/2019] [Indexed: 12/16/2022] Open
Abstract
Effective delivery of oxygen and essential nutrients to vital organs and tissues throughout the body requires adequate blood flow supplied through resistance vessels. The intimate relationship between intracellular calcium ([Ca2+]i) and regulation of membrane potential (Vm) is indispensable for maintaining blood flow regulation. In particular, Ca2+-activated K+ (KCa) channels were ascertained as transducers of elevated [Ca2+]i signals into hyperpolarization of Vm as a pathway for decreasing vascular resistance, thereby enhancing blood flow. Recent evidence also supports the reverse role for KCa channels, in which they facilitate Ca2+ influx into the cell interior through open non-selective cation (e.g., transient receptor potential; TRP) channels in accord with robust electrical (hyperpolarization) and concentration (~20,000-fold) transmembrane gradients for Ca2+. Such an arrangement supports a feed-forward activation of Vm hyperpolarization while potentially boosting production of nitric oxide. Furthermore, in vascular types expressing TRP channels but deficient in functional KCa channels (e.g., collecting lymphatic endothelium), there are profound alterations such as downstream depolarizing ionic fluxes and the absence of dynamic hyperpolarizing events. Altogether, this review is a refined set of evidence-based perspectives focused on the role of the endothelial KCa and TRP channels throughout multiple experimental animal models and vascular types. We discuss the diverse interactions among KCa and TRP channels to integrate Ca2+, oxidative, and electrical signaling in the context of cardiovascular physiology and pathology. Building from a foundation of cellular biophysical data throughout a wide and diverse compilation of significant discoveries, a translational narrative is provided for readers toward the treatment and prevention of chronic, age-related cardiovascular disease.
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Affiliation(s)
- Erik J Behringer
- Department of Basic Sciences, 11041 Campus Street, Risley Hall, Loma Linda University, Loma Linda, CA 92350, USA.
| | - Md A Hakim
- Department of Basic Sciences, 11041 Campus Street, Risley Hall, Loma Linda University, Loma Linda, CA 92350, USA.
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Svobodova B, Lichtenegger M, Platzer D, Di Giuro CML, de la Cruz GG, Glasnov T, Schreibmayer W, Groschner K. A single point mutation in the TRPC3 lipid-recognition window generates supersensitivity to benzimidazole channel activators. Cell Calcium 2019; 79:27-34. [PMID: 30798155 DOI: 10.1016/j.ceca.2019.02.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 02/15/2019] [Accepted: 02/15/2019] [Indexed: 12/27/2022]
Abstract
Mutation of a single residue within the recently identified lipid (diacylglycerol) recognition window of TRPC3 (G652A) was found to abolish channel activation via endogenous lipid mediators while retaining sensitivity to the non-lipid activator GSK1702934A (abb. GSK). The mechanism of this change in chemical sensing by TRPC3 was analysed by whole-cell and single channel electrophysiology as well as Ca2+ imaging. Currents initiated by GSK or the structural (benzimidazole) analog BI-2 were significantly larger in cells expressing the G652A mutant as compared to wild type (WT) channels. Whole cell patch-clamp experiments revealed that enhanced sensitivity to benzimidazoles was not due to augmented potency but reflected enhanced efficacy of benzimidazoles. Single channel analysis demonstrated that neither unitary conductance nor I-V characteristics were altered by the G652A mutation, precluding altered pore architecture as the basis of enhanced efficacy. These experiments uncovered a distinct gating pattern of BI-2-activated G652A mutant channels, featuring a unique, long-lived open state. Moreover, G652A mutant channels lacked PLC/diacylglycerol mediated cross-desensitization for GSK activation as typically observed for TRPC3. Lack of desensitization in G652A channels enabled large GSK/BI-2-induced Ca2+ signals in conditions that fully desensitized TRPC3 WT channels. We demonstrate that the lipid-recognition window of TRPC3 determines both sensitivity to lipid mediators and chemical gating by benzimidazoles. TRPC3 mutations within this lipid interaction site are suggested as a basis for chemogenetic targeting of TRPC3-signaling.
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Affiliation(s)
- Barbora Svobodova
- Gottfried-Schatz Research Center (Biophysics), Medical University of Graz, Austria
| | | | - Dieter Platzer
- Gottfried-Schatz Research Center (Biophysics), Medical University of Graz, Austria
| | | | | | - Toma Glasnov
- Institute of Chemistry, University of Graz, Austria
| | | | - Klaus Groschner
- Gottfried-Schatz Research Center (Biophysics), Medical University of Graz, Austria.
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