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Charlick JN, Bozadzhieva D, Butler AS, Wilkinson KA, Marrion NV. A single coiled-coil domain mutation in hIKCa channel subunits disrupts preferential formation of heteromeric hSK1:hIKCa channels. Eur J Neurosci 2024; 59:3-16. [PMID: 38018635 PMCID: PMC10952195 DOI: 10.1111/ejn.16189] [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: 02/09/2023] [Revised: 09/22/2023] [Accepted: 10/25/2023] [Indexed: 11/30/2023]
Abstract
The expression of IKCa (SK4) channel subunits overlaps with that of SK channel subunits, and it has been proposed that the two related subunits prefer to co-assemble to form heteromeric hSK1:hIKCa channels. This implicates hSK1:hIKCa heteromers in physiological roles that might have been attributed to activation of SK channels. We have used a mutation approach to confirm formation of heterometric hSK1:hIKCa channels. Introduction of residues within hSK1 that were predicted to impart sensitivity to the hIKCa current blocker TRAM-34 changed the pharmacology of functional heteromers. Heteromeric channels formed between wildtype hIKCa and mutant hSK1 subunits displayed a significantly higher sensitivity and maximum block to addition of TRAM-34 than heteromers formed between wildtype subunits. Heteromer formation was disrupted by a single point mutation within one COOH-terminal coiled-coil domain of the hIKCa channel subunit. This mutation only disrupted the formation of hSK1:hIKCa heteromeric channels, without affecting the formation of homomeric hIKCa channels. Finally, the Ca2+ gating sensitivity of heteromeric hSK1:hIKCa channels was found to be significantly lower than the Ca2+ gating sensitivity of homomeric hIKCa channels. These data confirmed the preferred formation of heteromeric channels that results from COOH-terminal interactions between subunits. The distinct sensitivity of the heteromer to activation by Ca2+ suggests that heteromeric channels fulfil a distinct function within those neurons that express both subunits.
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Affiliation(s)
- James N. Charlick
- School of Physiology, Pharmacology and NeuroscienceUniversity of BristolBristolUK
| | - Daniella Bozadzhieva
- School of Physiology, Pharmacology and NeuroscienceUniversity of BristolBristolUK
| | - Andrew S. Butler
- School of Physiology, Pharmacology and NeuroscienceUniversity of BristolBristolUK
| | - Kevin A. Wilkinson
- School of Physiology, Pharmacology and NeuroscienceUniversity of BristolBristolUK
| | - Neil V. Marrion
- School of Physiology, Pharmacology and NeuroscienceUniversity of BristolBristolUK
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2
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Bocian R, Broncel A, Konopacki J. Noradrenergic α1, α2, and β1receptors mediate VNS-induced theta oscillations. Brain Res 2023; 1804:148266. [PMID: 36717012 DOI: 10.1016/j.brainres.2023.148266] [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: 11/27/2022] [Revised: 01/24/2023] [Accepted: 01/25/2023] [Indexed: 01/30/2023]
Abstract
Although vagal nerve stimulation (VNS) has been employed with success for almost four decades in many central nervous system disturbances, the physiological and pharmacological processes underlying this therapy are still unclear. Searching for central mechanisms of VNS is clinically limited. Hence, in many experiments, VNS technique is tested on the model of laboratory animals. In the present study we proceed with the experiments to verify some central effects of VNS. Specifically, we focussed on the hippocampal formation (HPC) noradrenergic profile which underlines the VNS-induced theta oscillations in anesthetized rats (Broncel et al., 2017; 2021). The effects of noradrenaline (NE) and selective noradrenergic α and β agonists and antagonists were tested in experiments organized in three stages. Initially, a nonspecific noradrenergic agonist, noradrenaline, was administrated. In the second stage, noradrenergic α and β agonists were applied. In the last stage, the administration of selected agonists was pretreated by specific antagonists. The results of the present study provide evidence that the selective activation of HPC α1, α2, and β1 noradrenergic receptors produce the inhibition of VNS-induced theta oscillations. Hippocampal β2 and β3 receptors were found not to be involved in the modulation of oscillations produced by the vagal nerve stimulation. The obtained outcomes are discussed in light of the effects of increased exogenous NE and induced release of endogenous NE.
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Affiliation(s)
- R Bocian
- Department of Neurobiology, Faculty of Biology and Environmental Protection, The University of Lodz, Pomorska St. No 141/143, 90-236 Lodz, Poland.
| | - A Broncel
- Neuromedical Ltd., Research Department, Natolin 15, 92-701 Lodz, Poland.
| | - J Konopacki
- Department of Neurobiology, Faculty of Biology and Environmental Protection, The University of Lodz, Pomorska St. No 141/143, 90-236 Lodz, Poland.
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3
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Cammalleri M, Amato R, Dal Monte M, Filippi L, Bagnoli P. The β3 adrenoceptor in proliferative retinopathies: "Cinderella" steps out of its family shadow. Pharmacol Res 2023; 190:106713. [PMID: 36863427 DOI: 10.1016/j.phrs.2023.106713] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 02/14/2023] [Accepted: 02/27/2023] [Indexed: 03/04/2023]
Abstract
In the retina, hypoxic condition leads to overgrowing leaky vessels resulting in altered metabolic supply that may cause impaired visual function. Hypoxia-inducible factor-1 (HIF-1) is a central regulator of the retinal response to hypoxia by activating the transcription of numerous target genes, including vascular endothelium growth factor, which acts as a major player in retinal angiogenesis. In the present review, oxygen urge by the retina and its oxygen sensing systems including HIF-1 are discussed in respect to the role of the beta-adrenergic receptors (β-ARs) and their pharmacologic manipulation in the vascular response to hypoxia. In the β-AR family, β1- and β2-AR have long been attracting attention because their pharmacology is intensely used for human health, while β3-AR, the third and last cloned receptor is no longer increasingly emerging as an attractive target for drug discovery. Here, β3-AR, a main character in several organs including the heart, the adipose tissue and the urinary bladder, but so far a supporting actor in the retina, has been thoroughly examined in respect to its function in retinal response to hypoxia. In particular, its oxygen dependence has been taken as a key indicator of β3-AR involvement in HIF-1-mediated responses to oxygen. Hence, the possibility of β3-AR transcription by HIF-1 has been discussed from early circumstantial evidence to the recent demonstration that β3-AR acts as a novel HIF-1 target gene by playing like a putative intermediary between oxygen levels and retinal vessel proliferation. Thus, targeting β3-AR may implement the therapeutic armamentarium against neovascular pathologies of the eye.
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Affiliation(s)
| | - Rosario Amato
- Department of Biology, University of Pisa, Pisa, Italy
| | | | - Luca Filippi
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Paola Bagnoli
- Department of Biology, University of Pisa, Pisa, Italy.
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4
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Tau isoform-specific enhancement of L-type calcium current and augmentation of afterhyperpolarization in rat hippocampal neurons. Sci Rep 2022; 12:15231. [PMID: 36075936 PMCID: PMC9458744 DOI: 10.1038/s41598-022-18648-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Accepted: 08/17/2022] [Indexed: 11/08/2022] Open
Abstract
Accumulation of tau is observed in dementia, with human tau displaying 6 isoforms grouped by whether they display either 3 or 4 C-terminal repeat domains (3R or 4R) and exhibit no (0N), one (1N) or two (2N) N terminal repeats. Overexpression of 4R0N-tau in rat hippocampal slices enhanced the L-type calcium (Ca2+) current-dependent components of the medium and slow afterhyperpolarizations (AHPs). Overexpression of both 4R0N-tau and 4R2N-tau augmented CaV1.2-mediated L-type currents when expressed in tsA-201 cells, an effect not observed with the third 4R isoform, 4R1N-tau. Current enhancement was only observed when the pore-forming subunit was co-expressed with CaVβ3 and not CaVβ2a subunits. Non-stationary noise analysis indicated that enhanced Ca2+ channel current arose from a larger number of functional channels. 4R0N-tau and CaVβ3 were found to be physically associated by co-immunoprecipitation. In contrast, the 4R1N-tau isoform that did not augment expressed macroscopic L-type Ca2+ current exhibited greatly reduced binding to CaVβ3. These data suggest that physical association between tau and the CaVβ3 subunit stabilises functional L-type channels in the membrane, increasing channel number and Ca2+ influx. Enhancing the Ca2+-dependent component of AHPs would produce cognitive impairment that underlie those seen in the early phases of tauopathies.
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5
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Broncel A, Bocian R, Kłos-Wojtczak P, Konopacki J. Noradrenergic Profile of Hippocampal Formation Theta Rhythm in Anaesthetized Rats. Neuroscience 2021; 473:13-28. [PMID: 34418519 DOI: 10.1016/j.neuroscience.2021.08.008] [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: 02/24/2021] [Revised: 08/11/2021] [Accepted: 08/12/2021] [Indexed: 10/20/2022]
Abstract
The present study was undertaken to identify the noradrenergic receptors underlying the production of hippocampal formation (HPC) type 2 theta rhythm. The experiments were performed on urethanized rats wherein type 2 theta is the only rhythm present. In three independent stages of experiments, the effects of noradrenaline (NE) and selective noradrenergic α and β agonists and antagonists were tested. We indicate that the selective activation of three HPC noradrenergic receptors, α1, α2 and β1, induced a similar effect (i.e., inhibition) on type 2 theta rhythm. The remaining HPC β2 and β3 noradrenergic receptors do not seem to be directly involved in the pharmacological mechanism responsible for the suppression of theta rhythm in anaesthetized rats. Obtained results provide evidence for the suppressant effect of exogenous NE on HPC type 2 theta rhythm and show the crucial role of α1, α2 and β1 noradrenergic receptors in the modulation of HPC mechanisms of oscillations and synchrony. This finding is in contrast to the effects of endogenous NE produced by electrical stimulation of the locus coeruleus (LC) and procaine injection into the LC (Broncel et al., 2020).
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Affiliation(s)
- A Broncel
- Neuromedical, Research Department, Natolin 15, 92-701 Lodz, Poland.
| | - R Bocian
- Department of Neurobiology, Faculty of Biology and Environmental Protection, The University of Lodz, Pomorska St. No 141/143, 90-236 Lodz, Poland.
| | - P Kłos-Wojtczak
- Neuromedical, Research Department, Natolin 15, 92-701 Lodz, Poland.
| | - J Konopacki
- Department of Neurobiology, Faculty of Biology and Environmental Protection, The University of Lodz, Pomorska St. No 141/143, 90-236 Lodz, Poland.
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6
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Wang Y, Xu L, Liu MZ, Hu DD, Fang F, Xu DJ, Zhang R, Hua XX, Li JB, Zhang L, Huang LN, Mu D. Norepinephrine modulates wakefulness via α1 adrenoceptors in paraventricular thalamic nucleus. iScience 2021; 24:103015. [PMID: 34522858 PMCID: PMC8426266 DOI: 10.1016/j.isci.2021.103015] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 07/10/2021] [Accepted: 08/18/2021] [Indexed: 11/26/2022] Open
Abstract
Norepinephrine (NE) neurons in the locus coeruleus (LC) play key roles in modulating sleep and wakefulness. Recent studies have revealed that the paraventricular thalamic nucleus (PVT) is a critical wakefulness-controlling nucleus in mice. However, the effects of NE on PVT neurons remain largely unknown. Here, we investigated the mechanisms of NE modulating wakefulness in the PVT by using viral tracing, behavioral tests, slice electrophysiology, and optogenetics techniques. We found that the PVT-projecting LC neurons had few collateral projections to other brain nuclei. Behavioral tests showed that specific activation of the LC-PVT projections or microinjection of NE into the PVT accelerated emergence from general anesthesia and enhanced locomotion activity. Moreover, brain slice recording results indicated that NE increased the activity of the PVT neurons mainly by increasing the frequency of spontaneous excitatory postsynaptic currents via α1 adrenoceptors. Thus, our results demonstrate that NE modulates wakefulness via α1 adrenoceptors in the PVT.
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Affiliation(s)
- Yan Wang
- Department of Anesthesiology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, No. 650 Xin Song Jiang Road, Shanghai 201620, China
| | - Ling Xu
- Department of Anesthesiology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, No. 650 Xin Song Jiang Road, Shanghai 201620, China
| | - Ming-Zhe Liu
- Department of Respiratory, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou 510120, China
| | - Dan-Dan Hu
- Tongji University School of Medicine, Shanghai, China
| | - Fang Fang
- Department of Endocrinology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 201620, China
| | - Dao-Jie Xu
- Department of Anesthesiology, Huashan Hospital, Fudan University, Shanghai 200040, China
| | - Rui Zhang
- Department of Anesthesiology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, No. 650 Xin Song Jiang Road, Shanghai 201620, China
| | - Xiao-Xiao Hua
- Tongji University School of Medicine, Shanghai, China
| | - Jin-Bao Li
- Department of Anesthesiology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, No. 650 Xin Song Jiang Road, Shanghai 201620, China
| | - Ling Zhang
- Tongji University School of Medicine, Shanghai, China
| | - Li-Na Huang
- Department of Anesthesiology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, No. 650 Xin Song Jiang Road, Shanghai 201620, China
| | - Di Mu
- Department of Anesthesiology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, No. 650 Xin Song Jiang Road, Shanghai 201620, China
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7
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Septotemporal variation in beta-adrenergic modulation of short-term dynamics in the hippocampus. IBRO Neurosci Rep 2021; 11:64-72. [PMID: 34409401 PMCID: PMC8363828 DOI: 10.1016/j.ibneur.2021.07.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Accepted: 07/31/2021] [Indexed: 12/15/2022] Open
Abstract
Recent evidence shows a greater facilitating effect of beta-adrenergic receptors (β-ARs) on long-term synaptic plasticity in the ventral versus the dorsal hippocampus. Here, using field potentials from the CA1 area and a ten-pulse stimulation train of varying frequency we show that activation of β-ARs by isoproterenol preferentially facilitates the output from the dorsal hippocampus at the frequency range of 3–40 Hz without affecting short-term synaptic plasticity. Furthermore, isoproterenol increases basal synaptic transmission in the dorsal hippocampus only and enhances basal neuronal excitation more in the dorsal than the ventral hippocampus. These results suggest that β-AR-modulation of short-term neuronal dynamics differs along the longitudinal axis of the hippocampus, thereby contributing to functional specialization along the same axis. We studied the effects of isoproterenol (ISO) in dorsal (DH) and ventral (VH) hippocampus. ISO increased synaptic transmission and population spike more in DH than VH. ISO modulated short-term changes of population spike in the dorsal hippocampus only. ISO did not affect short-term changes of synaptic transmission in DH or VH. β adrenergic receptors modulate short-term changes in excitation in DH only.
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8
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Yu L, Chu C, Yuan Y, Guo X, Lei C, Sheng H, Yang L, Cui D, Lai B, Zheng P. Activity in projection neurons from prelimbic cortex to the PVT is necessary for retrieval of morphine withdrawal memory. Cell Rep 2021; 35:108958. [PMID: 33826893 DOI: 10.1016/j.celrep.2021.108958] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 12/28/2020] [Accepted: 03/17/2021] [Indexed: 11/25/2022] Open
Abstract
Previous work has shown that the paraventricular nucleus of the thalamus (PVT) is an important region that is involved in the conditioned context-induced retrieval of morphine withdrawal memory. However, the upstream neural circuits that activate the PVT to participate in the conditioned context-induced retrieval of morphine withdrawal memory remain unknown. In the present work, we find that the conditioned context activates projection neurons from the prelimbic cortex (PrL) to the PVT, and the inhibition of PrL-PVT projection neurons inhibits the conditioned context-induced retrieval of morphine withdrawal memory; the conditioned context induces an increase in Arc expression, intrinsic excitability, and glutamate output in PrL-PVT projection neurons in morphine-withdrawn mice. These results suggest that the activity of PrL-PVT projection neurons is necessary for the retrieval of morphine withdrawal memory, and the conditioned context causes a plastic change in the activity in these projection neurons during the withdrawal memory retrieval.
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Affiliation(s)
- Lanfang Yu
- State Key Laboratory of Medical Neurobiology, Institutes of Brain Science, Fudan University, Shanghai 200032, China
| | - Chenshan Chu
- State Key Laboratory of Medical Neurobiology, Institutes of Brain Science, Fudan University, Shanghai 200032, China
| | - Yu Yuan
- State Key Laboratory of Medical Neurobiology, Institutes of Brain Science, Fudan University, Shanghai 200032, China
| | - Xinli Guo
- State Key Laboratory of Medical Neurobiology, Institutes of Brain Science, Fudan University, Shanghai 200032, China
| | - Chao Lei
- State Key Laboratory of Medical Neurobiology, Institutes of Brain Science, Fudan University, Shanghai 200032, China
| | - Huan Sheng
- State Key Laboratory of Medical Neurobiology, Institutes of Brain Science, Fudan University, Shanghai 200032, China
| | - Li Yang
- State Key Laboratory of Medical Neurobiology, Institutes of Brain Science, Fudan University, Shanghai 200032, China
| | - Dongyang Cui
- State Key Laboratory of Medical Neurobiology, Institutes of Brain Science, Fudan University, Shanghai 200032, China
| | - Bin Lai
- State Key Laboratory of Medical Neurobiology, Institutes of Brain Science, Fudan University, Shanghai 200032, China.
| | - Ping Zheng
- State Key Laboratory of Medical Neurobiology, Institutes of Brain Science, Fudan University, Shanghai 200032, China; Department of Neurology of Zhongshan Hospital, MOE Frontier Center for Brain Science, School of Basic Medical Sciences, Shanghai, China.
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9
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Fong Z, Griffin CS, Hollywood MA, Thornbury KD, Sergeant GP. β 3-Adrenoceptor agonists inhibit purinergic receptor-mediated contractions of the murine detrusor. Am J Physiol Cell Physiol 2019; 317:C131-C142. [PMID: 31042424 DOI: 10.1152/ajpcell.00488.2018] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
β3-Adrenoceptor (β3-AR) agonists are used to treat overactive bladder syndrome; however, their mechanism of action has not been determined. The aims of this study were to compare the effects of β3-AR agonists on cholinergic versus purinergic receptor-mediated contractions of the detrusor and to examine the mechanisms underlying inhibition of the purinergic responses by β3-AR agonists. Isometric tension recordings were made from strips of murine detrusor and whole cell current recordings were made from freshly isolated detrusor myocytes using the patch-clamp technique. Transcriptional expression of exchange protein directly activated by cAMP (EPAC) subtypes in detrusor strips was assessed using RT-PCR and real-time quantitative PCR. The β3-AR agonists BRL37344 and CL316243 (100 nM) inhibited cholinergic nerve-mediated contractions of the detrusor by 19 and 23%, respectively, but did not reduce contractions induced by the cholinergic agonist carbachol (300 nM). In contrast, BRL37344 and CL316243 inhibited purinergic nerve-mediated responses by 55 and 56%, respectively, and decreased the amplitude of contractions induced by the P2X receptor agonist α,β-methylene ATP by 40 and 45%, respectively. The adenylate cyclase activator forskolin inhibited purinergic responses, and these effects were mimicked by a combination of the PKA activator N6-monobutyryl-cAMP and the EPAC activator 8-pCPT-2'-O-methyl-cAMP-AM (007-AM). Application of ATP (1 μM) evoked reproducible P2X currents in isolated detrusor myocytes voltage-clamped at -60 mV. These responses were reduced in amplitude in the presence of BRL37344 and also by 007-AM. This study demonstrates that β3-AR agonists reduce postjunctional purinergic responses in the detrusor via a pathway involving activation of the cAMP effector EPAC.
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Affiliation(s)
- Zhihui Fong
- Smooth Muscle Research Centre, Dundalk Institute of Technology , Dundalk , Ireland
| | - Caoimhín S Griffin
- Smooth Muscle Research Centre, Dundalk Institute of Technology , Dundalk , Ireland
| | - Mark A Hollywood
- Smooth Muscle Research Centre, Dundalk Institute of Technology , Dundalk , Ireland
| | - Keith D Thornbury
- Smooth Muscle Research Centre, Dundalk Institute of Technology , Dundalk , Ireland
| | - Gerard P Sergeant
- Smooth Muscle Research Centre, Dundalk Institute of Technology , Dundalk , Ireland
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Everything You Always Wanted to Know about β 3-AR * (* But Were Afraid to Ask). Cells 2019; 8:cells8040357. [PMID: 30995798 PMCID: PMC6523418 DOI: 10.3390/cells8040357] [Citation(s) in RCA: 76] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 03/26/2019] [Accepted: 04/12/2019] [Indexed: 12/22/2022] Open
Abstract
The beta-3 adrenergic receptor (β3-AR) is by far the least studied isotype of the beta-adrenergic sub-family. Despite its study being long hampered by the lack of suitable animal and cellular models and inter-species differences, a substantial body of literature on the subject has built up in the last three decades and the physiology of β3-AR is unraveling quickly. As will become evident in this work, β3-AR is emerging as an appealing target for novel pharmacological approaches in several clinical areas involving metabolic, cardiovascular, urinary, and ocular disease. In this review, we will discuss the most recent advances regarding β3-AR signaling and function and summarize how these findings translate, or may do so, into current clinical practice highlighting β3-AR’s great potential as a novel therapeutic target in a wide range of human conditions.
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