1
|
Hone AJ, Rueda-Ruzafa L, Gordon TJ, Gajewiak J, Christensen S, Dyhring T, Albillos A, McIntosh JM. Expression of α3β2β4 nicotinic acetylcholine receptors by rat adrenal chromaffin cells determined using novel conopeptide antagonists. J Neurochem 2020; 154:158-176. [PMID: 31967330 DOI: 10.1111/jnc.14966] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 12/17/2019] [Accepted: 01/13/2020] [Indexed: 01/07/2023]
Abstract
Adrenal chromaffin cells release neurotransmitters in response to stress and may be involved in conditions such as post-traumatic stress and anxiety disorders. Neurotransmitter release is triggered, in part, by activation of nicotinic acetylcholine receptors (nAChRs). However, despite decades of use as a model system for studying exocytosis, the nAChR subtypes involved have not been pharmacologically identified. Quantitative real-time PCR of rat adrenal medulla revealed an abundance of mRNAs for α3, α7, β2, and β4 subunits. Whole-cell patch-clamp electrophysiology of chromaffin cells and subtype-selective ligands were used to probe for nAChRs derived from the mRNAs found in adrenal medulla. A novel conopeptide antagonist, PeIA-5469, was created that is highly selective for α3β2 over other nAChR subtypes heterologously expressed in Xenopus laevis oocytes. Experiments using PeIA-5469 and the α3β4-selective α-conotoxin TxID revealed that rat adrenal medulla contain two populations of chromaffin cells that express either α3β4 nAChRs alone or α3β4 together with the α3β2β4 subtype. Conclusions were derived from observations that acetylcholine-gated currents in some cells were sensitive to inhibition by PeIA-5469 and TxID, while in other cells, currents were sensitive only to TxID. Expression of functional α7 nAChRs was determined using three α7-selective ligands: the agonist PNU282987, the positive allosteric modulator PNU120596, and the antagonist α-conotoxin [V11L,V16D]ArIB. The results of these studies identify for the first time the expression of α3β2β4 nAChRs as well as functional α7 nAChRs by rat adrenal chromaffin cells.
Collapse
Affiliation(s)
- Arik J Hone
- George E. Whalen Veterans Affairs Medical Center, Salt Lake City, Utah, USA.,School of Biological Sciences and University of Utah, Salt Lake City, Utah, USA.,Departament of Pharmacology and Therapeutics, Universidad Autónoma de Madrid, Madrid, Spain
| | - Lola Rueda-Ruzafa
- Departament of Pharmacology and Therapeutics, Universidad Autónoma de Madrid, Madrid, Spain.,Biomedical Research Center (CINBIO), University of Vigo, Vigo, Spain
| | - Thomas J Gordon
- School of Biological Sciences and University of Utah, Salt Lake City, Utah, USA
| | - Joanna Gajewiak
- School of Biological Sciences and University of Utah, Salt Lake City, Utah, USA
| | - Sean Christensen
- School of Biological Sciences and University of Utah, Salt Lake City, Utah, USA
| | | | - Almudena Albillos
- Departament of Pharmacology and Therapeutics, Universidad Autónoma de Madrid, Madrid, Spain
| | - J Michael McIntosh
- George E. Whalen Veterans Affairs Medical Center, Salt Lake City, Utah, USA.,School of Biological Sciences and University of Utah, Salt Lake City, Utah, USA.,Department of Psychiatry, University of Utah, Salt Lake City, Utah, USA
| |
Collapse
|
2
|
Carbone E, Borges R, Eiden LE, García AG, Hernández‐Cruz A. Chromaffin Cells of the Adrenal Medulla: Physiology, Pharmacology, and Disease. Compr Physiol 2019; 9:1443-1502. [DOI: 10.1002/cphy.c190003] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
|
3
|
Sanz-Lázaro S, Jiménez-Pompa A, Carmona-Hidalgo B, Ubeda M, Muñoz L, Caba-González JC, Hernández-Vivanco A, López-García S, Albillos A, Albillos A. The firing frequency of spontaneous action potentials and their corresponding evoked exocytosis are increased in chromaffin cells of CCl 4 -induced cirrhotic rats with respect to control rats. J Neurochem 2018; 148:359-372. [PMID: 30347483 DOI: 10.1111/jnc.14618] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Revised: 10/09/2018] [Accepted: 10/18/2018] [Indexed: 11/29/2022]
Abstract
High catecolamine plasma levels because of sympathetic nervous system over-activity contribute to cirrhosis progression. The aim of this study was to investigate whether chromaffin cells of the adrenal gland might potentiate the deleterious effect exerted by this over-activity. Electrophysiological patch-clamp and amperometric experiments with carbon-fibre electrodes were conducted in single chromaffin cells of control and CCl4 -induced cirrhotic rats. The spontaneous action potential firing frequency was increased in chromaffin cells of cirrhotic rats with respect to control rats. The exocytosis evoked by that firing was also increased. However, exocytosis elicited by ACh did not vary between control and cirrhotic rats. Exocytosis triggered by depolarizing pulses was also unchanged. Amperometric recordings confirmed the lack of increased catecholamine charge released in cirrhosis after ACh or depolarization stimuli. However, the amperometric spikes exhibited faster kinetics of release. The overall Ca2+ entry through voltage-dependent Ca2+ channels (VDCC), or in particular through Cav1 channels, did not vary between chromaffin cells of control and cirrhotic rats. The inhibition of VDCC by methionine-enkephaline or ATP was not either altered, but it was increased by adrenaline in cells of cirrhotic rats. When a cocktail composed by the three neurotransmitters was tested in order to approach a situation closer to the physiological condition, the inhibition of VDCC was similar between both types of cells. In summary, chromaffin cells of the adrenal gland might contribute to exacerbate the sympathetic nervous system over-activity in cirrhosis because of an increased exocytosis elicited by an enhanced spontaneous electrical activity.
Collapse
Affiliation(s)
- Sara Sanz-Lázaro
- Departamento de Farmacología y Terapéutica, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain
| | - Amanda Jiménez-Pompa
- Departamento de Farmacología y Terapéutica, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain
| | - Beatriz Carmona-Hidalgo
- Departamento de Farmacología y Terapéutica, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain
| | - María Ubeda
- Laboratorio de Enfermedades del Sistema Inmune, Departamento de Medicina, Universidad de Alcalá, Alcalá de Henares, Madrid, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Instituto de Salud Carlos III, Madrid, Spain
| | - Leticia Muñoz
- Laboratorio de Enfermedades del Sistema Inmune, Departamento de Medicina, Universidad de Alcalá, Alcalá de Henares, Madrid, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Instituto de Salud Carlos III, Madrid, Spain
| | - Jose Carlos Caba-González
- Departamento de Farmacología y Terapéutica, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain
| | - Alicia Hernández-Vivanco
- Departamento de Farmacología y Terapéutica, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain
| | - Sarai López-García
- Departamento de Farmacología y Terapéutica, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain
| | - Agustín Albillos
- Departamento de Farmacología y Terapéutica, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain.,Laboratorio de Enfermedades del Sistema Inmune, Departamento de Medicina, Universidad de Alcalá, Alcalá de Henares, Madrid, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Instituto de Salud Carlos III, Madrid, Spain.,Servicio de Gastroenterología y Hepatología, Hospital Universitario Ramón y Cajal, IRYCIS, Madrid, Spain
| | - Almudena Albillos
- Departamento de Farmacología y Terapéutica, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain
| |
Collapse
|
4
|
Albillos A, McIntosh JM. Human nicotinic receptors in chromaffin cells: characterization and pharmacology. Pflugers Arch 2017; 470:21-27. [PMID: 29058146 DOI: 10.1007/s00424-017-2073-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Revised: 09/14/2017] [Accepted: 09/19/2017] [Indexed: 02/03/2023]
Abstract
During the last 10 years, we have been working on human chromaffin cells obtained from the adrenal gland of organ donors that suffered encephalic or cardiac death. We first electrophysiologically characterized the nicotinic acetylcholine receptors (nAChRs) activated by acetylcholine, and their contribution to the exocytosis of chromaffin vesicles and release of catecholamines. We have shown that these cells possess an adrenergic phenotype. This phenotype may contribute to an increased expression of α7 nAChRs in these cells, allowing for recording of α7 nAChR currents, something that had previously not been achieved in non-human species. The use of α-conotoxins allowed us to characterize non-α7 nAChR subtypes and, together with molecular biology experiments, conclude that the predominant nAChR subtype in human chromaffin cells is α3β4* (asterisk indicates the posible presence of additional subunits). In addition, there is a minor population of αxβ2 nAChRs. Both α7 and non-α7 nAChR subtypes contribute to the exocytotic process. Exocytosis mediated by nAChRs could be as large in magnitude as that elicited by calcium entry through voltage-dependent calcium channels. Finally, we have also investigated the effect of nAChR-targeted tobacco cessation drugs on catecholamine release in chromaffin cells. We have concluded that at therapeutic concentrations, varenicline alone does not increase the frequency of action potentials evoked by ACh. However, varenicline in the presence of nicotine does increase this frequency, and thus, in the presence of both drugs, the probability of increased catecholamine release in human chromaffin cells is high.
Collapse
Affiliation(s)
- Almudena Albillos
- Departamento de Farmacología y Terapéutica, Facultad de Medicina, Universidad Autónoma de Madrid, Calle Arzobispo Morcillo 4, 28029, Madrid, Spain.
| | - J Michael McIntosh
- George E. Whalen Veterans Affairs Medical Center, Salt Lake City, UT, USA.,Department of Biology, University of Utah, Salt Lake City, UT, USA.,Department of Psychiatry, University of Utah, Salt Lake City, UT, USA
| |
Collapse
|
5
|
Roles of Na +, Ca 2+, and K + channels in the generation of repetitive firing and rhythmic bursting in adrenal chromaffin cells. Pflugers Arch 2017; 470:39-52. [PMID: 28776261 DOI: 10.1007/s00424-017-2048-1] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Accepted: 07/23/2017] [Indexed: 12/30/2022]
Abstract
Adrenal chromaffin cells (CCs) are the main source of circulating catecholamines (CAs) that regulate the body response to stress. Release of CAs is controlled neurogenically by the activity of preganglionic sympathetic neurons through trains of action potentials (APs). APs in CCs are generated by robust depolarization following the activation of nicotinic and muscarinic receptors that are highly expressed in CCs. Bovine, rat, mouse, and human CCs also express a composite array of Na+, K+, and Ca2+ channels that regulate the resting potential, shape the APs, and set the frequency of AP trains. AP trains of increasing frequency induce enhanced release of CAs. If the primary role of CCs is simply to relay preganglionic nerve commands to CA secretion, why should they express such a diverse set of ion channels? An answer to this comes from recent observations that, like in neurons, CCs undergo complex firing patterns of APs suggesting the existence of an intrinsic CC excitability (non-neurogenically controlled). Recent work has shown that CCs undergo occasional or persistent burst firing elicited by altered physiological conditions or deletion of pore-regulating auxiliary subunits. In this review, we aim to give a rationale to the role of the many ion channel types regulating CC excitability. We will first describe their functional properties and then analyze how they contribute to pacemaking, AP shape, and burst waveforms. We will also furnish clear indications on missing ion conductances that may be involved in pacemaking and highlight the contribution of the crucial channels involved in burst firing.
Collapse
|
6
|
Human native Ca v1 channels in chromaffin cells: contribution to exocytosis and firing of spontaneous action potentials. Eur J Pharmacol 2017; 796:115-121. [PMID: 27988286 DOI: 10.1016/j.ejphar.2016.12.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Revised: 12/02/2016] [Accepted: 12/05/2016] [Indexed: 01/31/2023]
Abstract
The present study was performed to evaluate the Cav1 channel subtypes expressed in human chromaffin cells and the role that these channels play in exocytosis and cell excitability. Here we show that human chromaffin cells obtained from organ donors express Cav1.2 and Cav1.3 subtypes using molecular and pharmacological techniques. Immunocytochemical data demonstrated the presence of Cav1.2 and Cav1.3 subtypes, but not Cav1.1 or Cav1.4. Electrophysiological experiments were conducted to investigate the contribution of Cav1 channels to the exocytotic process and cell excitability. Cav1 channels contribute to the exocytosis of secretory vesicles, evidenced by the block of 3μM nifedipine (36.5±2%) of membrane capacitance increment elicited by 200ms depolarizing pulses. These channels show a minor contribution to the initiation of spontaneous action potential firing, as shown by the 2.5 pA of current at the threshold potential (-34mV), which elicits 10.4mV of potential increment. In addition, we found that only 8% of human chromaffin cells exhibit spontaneous action potentials. These data offer novel information regarding human chromaffin cells and the role of human native Cav1 channels in exocytosis and cell excitability.
Collapse
|
7
|
Gil A, Torregrosa-Hetland CJ, González-Vélez V, Villanueva J, Garcia-Martinez V, Viniegra S, Segura J, Gutiérrez LM. Neurite extensions in chromaffin cells: study of the influence of the cytoskeletal structure on calcium dynamics and secretion. FRONTIERS IN LIFE SCIENCE 2012. [DOI: 10.1080/21553769.2012.745452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
8
|
Pérez-Alvarez A, Hernández-Vivanco A, Alonso Y Gregorio S, Tabernero A, McIntosh JM, Albillos A. Pharmacological characterization of native α7 nicotinic ACh receptors and their contribution to depolarization-elicited exocytosis in human chromaffin cells. Br J Pharmacol 2012; 165:908-21. [PMID: 21790533 DOI: 10.1111/j.1476-5381.2011.01596.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND AND PURPOSE Expression of α7 nicotinic acetylcholine receptors (nAChRs) and their role in exocytosis have not yet been examined in human chromaffin cells. EXPERIMENTAL APPROACH To characterize these receptors and investigate their function, patch-clamp experiments were performed in human chromaffin cells from organ donors. KEY RESULTS The nicotinic current provoked by 300µM ACh in voltage-clamped cells was blocked by the nicotinic receptor antagonists α-bungarotoxin (α-Bgtx; 1µM; 6 ± 1.7%) or methyllycaconitine (MLA; 10nM; 7 ± 1.6%), respectively, in an irreversible and reversible manner, without affecting exocytosis. Choline (10mM) pulses induced a biphasic current with an initial quickly activated (5.5 ± 0.4ms rise time) and inactivated component (8.5 ± 0.4ms time constant) (termed α7), which was blocked by α-Bgtx or MLA, followed by a slower component (non-α7). α7 nAChR currents were dissected by blocking the non-α7 nAChR current component of the ACh and choline response with the α6* nAChR blocker α-conotoxin (α-Ctx) MII[S4A, E11A, L15A]. PNU-282987, an α7 nAChR-specific agonist, elicited rapidly activated and rapidly inactivated currents. α7 nAChR-positive allosteric modulators, such as 5-hydroxyindole (1mM) and PNU-120596 (10µM), potentiated responses that were blocked by α-Bgtx or MLA. Exocytosis was evoked by depolarization-elicited α7 nAChR currents, using choline in the presence of α-Ctx MII[MS4A, E11A, L15A] or PNU-282987 as agonists. CONCLUSIONS AND IMPLICATIONS Our electrophysiological recordings of pure α7 nAChR currents elicited by rapid application of agonists demonstrated that functional α7 nAChRs are expressed and contribute to depolarization-elicited exocytosis in human chromaffin cells.
Collapse
Affiliation(s)
- Alberto Pérez-Alvarez
- Departamento de Farmacología y Terapéutica, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain.
| | | | | | | | | | | |
Collapse
|
9
|
Hernández-Vivanco A, Pérez-Alvarez A, Caba-González JC, Alonso MT, Moreno-Ortega AJ, Cano-Abad M, Ruiz-Nuño A, Carmona-Hidalgo B, Albillos A. Selectivity of Action of Pregabalin on Ca2+ Channels but Not on Fusion Pore, Exocytotic Machinery, or Mitochondria in Chromaffin Cells of the Adrenal Gland. J Pharmacol Exp Ther 2012; 342:263-72. [DOI: 10.1124/jpet.111.190652] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
|
10
|
Pérez-Alvarez A, Hernández-Vivanco A, McIntosh JM, Albillos A. Native α6β4* nicotinic receptors control exocytosis in human chromaffin cells of the adrenal gland. FASEB J 2011; 26:346-54. [PMID: 21917987 DOI: 10.1096/fj.11-190223] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
In the present study, we have electrophysiologically characterized native nicotinic acetylcholine receptors (nAChRs) in human chromaffin cells of the adrenal gland as well as their contribution to the exocytotic process. α-Conotoxin AuIB blocked by 14 ± 1% the acetylcholine (ACh)-induced nicotinic current. α-Conotoxin MII (α-Ctx MII) exhibited an almost full blockade of the nicotinic current at nanomolar concentrations (IC(50)=21.6 nM). The α6*-preferring α-Ctx MII mutant analogs, α-Ctx MII[H9A,L15A] and α-Ctx MII[S4A,E11A,L15A], blocked nAChR currents with an IC(50) of 217.8 and 33 nM, respectively. These data reveal that nAChRs in these cells include the α6* subtype. The washout of the blockade exerted by α-conotoxin BuIA (α-Ctx BuIA; 1 μM) on ACh-evoked currents was slight and slow, arguing in favor of the presence of a β4 subunit in the nAChR composition. Exocytosis was almost fully blocked by 1 μM α-Ctx MII, its mutant analogs, or α-Ctx BuIA. Finally, the fluorescent analog Alexa Fluor 546-BuIA showed distinct staining in these cells. Our results reveal that α6β4* nAChRs are expressed and contribute to exocytosis in human chromaffin cells of the adrenal gland, the main source of adrenaline under stressful situations.
Collapse
Affiliation(s)
- Alberto Pérez-Alvarez
- Departamento de Farmacología y Terapéutica, Universidad Autónoma de Madrid, Madrid, Spain.
| | | | | | | |
Collapse
|
11
|
Rosa JM, Torregrosa-Hetland CJ, Colmena I, Gutiérrez LM, García AG, Gandía L. Calcium entry through slow-inactivating L-type calcium channels preferentially triggers endocytosis rather than exocytosis in bovine chromaffin cells. Am J Physiol Cell Physiol 2011; 301:C86-98. [PMID: 21451100 DOI: 10.1152/ajpcell.00440.2010] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Calcium (Ca(2+))-dependent endocytosis has been linked to preferential Ca(2+) entry through the L-type (α(1D), Ca(V)1.3) of voltage-dependent Ca(2+) channels (VDCCs). Considering that the Ca(2+)-dependent exocytotic release of neurotransmitters is mostly triggered by Ca(2+) entry through N-(α(1B), Ca(V)2.2) or PQ-VDCCs (α(1A), Ca(V)2.1) and that exocytosis and endocytosis are coupled, the supposition that the different channel subtypes are specialized to control different cell functions is attractive. Here we have explored this hypothesis in primary cultures of bovine adrenal chromaffin cells where PQ channels account for 50% of Ca(2+) current (I(Ca)), 30% for N channels, and 20% for L channels. We used patch-clamp and fluorescence techniques to measure the exo-endocytotic responses triggered by long depolarizing stimuli, in 1, 2, or 10 mM concentrations of extracellular Ca(2+) ([Ca(2+)](e)). Exo-endocytotic responses were little affected by ω-conotoxin GVIA (N channel blocker), whereas ω-agatoxin IVA (PQ channel blocker) caused 80% blockade of exocytosis as well as endocytosis. In contrast, nifedipine (L channel blocker) only caused 20% inhibition of exocytosis but as much as 90% inhibition of endocytosis. Conversely, FPL67146 (an activator of L VDCCs) notably augmented endocytosis. Photoreleased caged Ca(2+) caused substantially smaller endocytotic responses compared with those produced by K(+) depolarization. Using fluorescence antibodies, no colocalization between L, N, or PQ channels with clathrin was found; a 20-30% colocalization was found between dynamin and all three channel antibodies. This is incompatible with the view that L channels are coupled to the endocytotic machine. Data rather support a mechanism implying the different inactivation rates of L (slow-inactivating) and N/PQ channels (fast-inactivating). Thus a slow but more sustained Ca(2+) entry through L channels could be a requirement to trigger endocytosis efficiently, at least in bovine chromaffin cells.
Collapse
Affiliation(s)
- Juliana M Rosa
- Instituto Teófilo Hernando, IIS del Hospital Universitario de Princesa, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain
| | | | | | | | | | | |
Collapse
|
12
|
Pérez-Alvarez A, Hernández-Vivanco A, Albillos A. Past, Present and Future of Human Chromaffin Cells: Role in Physiology and Therapeutics. Cell Mol Neurobiol 2010; 30:1407-15. [DOI: 10.1007/s10571-010-9582-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2010] [Accepted: 09/02/2010] [Indexed: 12/26/2022]
|