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Maldifassi MC, Guerra-Fernández MJ, Ponce D, Alfonso-Bueno S, Maripillán J, Vielma AH, Báez-Matus X, Marengo FD, Acuña-Castillo C, Sáez JC, Martínez AD, Cárdenas AM. Autocrine activation of P2X7 receptors mediates catecholamine secretion in chromaffin cells. Br J Pharmacol 2024. [PMID: 38679932 DOI: 10.1111/bph.16371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 02/23/2024] [Accepted: 03/04/2024] [Indexed: 05/01/2024] Open
Abstract
BACKGROUND AND PURPOSE ATP is highly accumulated in secretory vesicles and secreted upon exocytosis from neurons and endocrine cells. In adrenal chromaffin granules, intraluminal ATP reaches concentrations over 100 mM. However, how these large amounts of ATP contribute to exocytosis has not been investigated. EXPERIMENTAL APPROACH Exocytotic events in bovine and mouse adrenal chromaffin cells were measured with single cell amperometry. Cytosolic Ca2+ measurements were carried out in Fluo-4 loaded cells. Submembrane Ca2+ was examined in PC12 cells transfected with a membrane-tethered Ca2+ indicator Lck-GCaMP3. ATP release was measured using the luciferin/luciferase assay. Knockdown of P2X7 receptors was induced with short interfering RNA (siRNA). Direct Ca2+ influx through this receptor was measured using a P2X7 receptor-GCamp6 construct. KEY RESULTS ATP induced exocytosis in chromaffin cells, whereas the ectonucleotidase apyrase reduced the release events induced by the nicotinic agonist dimethylphenylpiperazinium (DMPP), high KCl, or ionomycin. The purinergic agonist BzATP also promoted a secretory response that was dependent on extracellular Ca2+. A740003, a P2X7 receptor antagonist, abolished secretory responses of these secretagogues. Exocytosis was also diminished in chromaffin cells when P2X7 receptors were silenced using siRNAs and in cells of P2X7 receptor knockout mice. In PC12 cells, DMPP induced ATP release, triggering Ca2+ influx through P2X7 receptors. Furthermore, BzATP, DMPP, and KCl allowed the formation of submembrane Ca2+ microdomains inhibited by A740003. CONCLUSION AND IMPLICATIONS Autocrine activation of P2X7 receptors constitutes a crucial feedback system that amplifies the secretion of catecholamines in chromaffin cells by favouring submembrane Ca2+ microdomains.
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Affiliation(s)
- María Constanza Maldifassi
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - María José Guerra-Fernández
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Daniela Ponce
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Samuel Alfonso-Bueno
- Instituto de Fisiología, Biología Molecular y Neurociencias. CONICET. Departamento de Fisiología y Biología Molecular y Celular. Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Jaime Maripillán
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Alex H Vielma
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Ximena Báez-Matus
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Fernando D Marengo
- Instituto de Fisiología, Biología Molecular y Neurociencias. CONICET. Departamento de Fisiología y Biología Molecular y Celular. Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Claudio Acuña-Castillo
- Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, USACH, Santiago, Chile
| | - Juan C Sáez
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Agustín D Martínez
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Ana M Cárdenas
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
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Gandini MA, Zamponi GW. Voltage‐gated calcium channel nanodomains: molecular composition and function. FEBS J 2021; 289:614-633. [DOI: 10.1111/febs.15759] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 02/05/2021] [Accepted: 02/10/2021] [Indexed: 12/16/2022]
Affiliation(s)
- Maria A. Gandini
- Department of Physiology and Pharmacology Alberta Children’s Hospital Research Institute Hotchkiss Brain Institute Cumming School of Medicine University of Calgary AB Canada
| | - Gerald W. Zamponi
- Department of Physiology and Pharmacology Alberta Children’s Hospital Research Institute Hotchkiss Brain Institute Cumming School of Medicine University of Calgary AB Canada
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Morachevskaya EA, Sudarikova AV. Actin dynamics as critical ion channel regulator: ENaC and Piezo in focus. Am J Physiol Cell Physiol 2021; 320:C696-C702. [PMID: 33471624 DOI: 10.1152/ajpcell.00368.2020] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Ion channels in plasma membrane play a principal role in different physiological processes, including cell volume regulation, signal transduction, and modulation of membrane potential in living cells. Actin-based cytoskeleton, which exists in a dynamic balance between monomeric and polymeric forms (globular and fibrillar actin), can be directly or indirectly involved in various cellular responses including modulation of ion channel activity. In this mini-review, we present an overview of the role of submembranous actin dynamics in the regulation of ion channels in excitable and nonexcitable cells. Special attention is focused on the important data about the involvement of actin assembly/disassembly and some actin-binding proteins in the control of the epithelial Na+ channel (ENaC) and mechanosensitive Piezo channels whose integral activity has a potential impact on membrane transport and multiple coupled cellular reactions. Growing evidence suggests that actin elements of the cytoskeleton can represent a "converging point" of various signaling pathways modulating the activity of ion transport proteins in cell membranes.
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Maldifassi MC, Momboisse F, Guerra MJ, Vielma AH, Maripillán J, Báez-Matus X, Flores-Muñoz C, Cádiz B, Schmachtenberg O, Martínez AD, Cárdenas AM. The interplay between α7 nicotinic acetylcholine receptors, pannexin-1 channels and P2X7 receptors elicit exocytosis in chromaffin cells. J Neurochem 2020; 157:1789-1808. [PMID: 32931038 DOI: 10.1111/jnc.15186] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 08/18/2020] [Accepted: 09/04/2020] [Indexed: 12/20/2022]
Abstract
Pannexin-1 (Panx1) forms plasma membrane channels that allow the exchange of small molecules between the intracellular and extracellular compartments, and are involved in diverse physiological and pathological responses in the nervous system. However, the signaling mechanisms that induce their opening still remain elusive. Here, we propose a new mechanism for Panx1 channel activation through a functional crosstalk with the highly Ca2+ permeable α7 nicotinic acetylcholine receptor (nAChR). Consistent with this hypothesis, we found that activation of α7 nAChRs induces Panx1-mediated dye uptake and ATP release in the neuroblastoma cell line SH-SY5Y-α7. Using membrane permeant Ca2+ chelators, total internal reflection fluorescence microscopy in SH-SY5Y-α7 cells expressing a membrane-tethered GCAMP3, and Src kinase inhibitors, we further demonstrated that Panx1 channel opening depends on Ca2+ signals localized in submembrane areas, as well as on Src kinases. In turn, Panx1 channels amplify cytosolic Ca2+ signals induced by the activation of α7 nAChRs, by a mechanism that seems to involve ATP release and P2X7 receptor activation, as hydrolysis of extracellular ATP with apyrase or blockage of P2X7 receptors with oxidized ATP significantly reduces the α7 nAChR-Ca2+ signal. The physiological relevance of this crosstalk was also demonstrated in neuroendocrine chromaffin cells, wherein Panx1 channels and P2X7 receptors contribute to the exocytotic release of catecholamines triggered by α7 nAChRs, as measured by amperometry. Together these findings point to a functional coupling between α7 nAChRs, Panx1 channels and P2X7 receptors with physiological relevance in neurosecretion.
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Affiliation(s)
- María C Maldifassi
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | | | - María J Guerra
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Alex H Vielma
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Jaime Maripillán
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Ximena Báez-Matus
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Carolina Flores-Muñoz
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile.,Programa de Doctorado en Ciencias, Universidad de Valparaíso, Chile
| | - Bárbara Cádiz
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile.,Programa de Magister en Ciencias Biológicas, Universidad de Valparaíso, Chile
| | - Oliver Schmachtenberg
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Agustín D Martínez
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Ana M Cárdenas
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
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