Despite being cloned several years ago, the expression of functional nicotinic acetylcholine receptors containing the human alpha6 subunit in recombinant mammalian cell lines has yet to be demonstrated. The resulting lack of selective ligands has hindered the evaluation of the role of alpha6-containing nicotinic receptors. We report that functional channels were recorded following co-transfection of human embryonic kidney (HEK-293) cells with a chimeric alpha6/alpha4 subunit and the beta4 nicotinic receptor subunit. They displayed an agonist rank order potency of epibatidinez.>>1,1-dimethyl-4-phenylpiperazinium (DMPP)>/=cytisine>acetylcholine>nicotine measured in a fluorescent imaging plate reader assay. Nicotine, cytisine, DMPP and epibatidine displayed partial agonist properties whilst alpha-conotoxin MII and methyllycaconitine blocked the functional responses elicited by acetylcholine stimulation. Co-transfection of the alpha6/alpha4 chimera with the beta2 nicotinic receptor subunit did not result in functional receptors. The human alpha6/alpha4beta4 chimeric nicotinic receptor expressed in HEK-293 cells may provide a valuable tool for the generation of subtype specific ligands.
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http://dx.doi.org/10.1016/s0014-2999(03)01540-1 | DOI Listing |
J Physiol
December 2024
Université Paris Cité, CNRS, ENS Paris Saclay, Centre Borelli UMR 9010, Paris, France.
Terminal Schwann cells (TSCs) are capable of regulating acetylcholine (ACh) release at the neuromuscular junction (NMJ). We have identified GABA as a gliotransmitter at mouse NMJs. When ACh activates α7 nicotinic ACh receptor (nAChRs) on TSCs, GABA is released and activates GABA receptors on the nerve terminal that subsequently reduce ACh release.
View Article and Find Full Text PDFConnect Tissue Res
December 2024
Arthroscopic Surgery Unit, Hospital Vithas Vitoria, Vitoria-Gasteiz, Spain.
Purpose: After peripheral nerve injury (PNI), prolonged denervation of the target muscle prevents adequate reinnervation even if the nerve is repaired. The aim of this work is to analyze the effect of intramuscular Platelet-Rich Plasma (PRP) in a denervated muscle due to PNI.Materials and.
View Article and Find Full Text PDFJ Orofac Orthop
December 2024
Department of Orthodontics, Beijing Stomatological Hospital, Capital Medical University, 100050, Beijing, China.
Purpose: We aimed to investigate early effects of regulating alpha‑7 nicotinic acetylcholine receptor (α7nAChR) agonists and antagonists on maxillary expansion in mice.
Methods: We allocated 36 six-week-old male C57BL/6J mice into three group: 1) expansion alone, 2) expansion plus the α7nAChR-specific agonist 3‑(2,4-dimethoxybenzylidene)-anabaseine dihydrochloride (GTS-21), and 3) expansion plus alpha-bungarotoxin (α-BTX), a competitive antagonist of α7nAChR. The groups were daily injected with saline, GTS-21 (4 mg/kg/day) or α‑BTX (1 mg/kg/day), respectively, from days 0-7.
Toxins (Basel)
November 2024
Institut des Neurosciences Paris-Saclay, UMR 9197, CNRS/Université Paris-Sud, 91198 Gif-sur-Yvette, Cedex, France.
Botulinum neurotoxin type-A (BoNT/A), which blocks quantal acetylcholine (ACh) release at the neuromuscular junction (NMJ), has demonstrated its efficacy in the symptomatic treatment of blepharospasm. In 3.89% of patients treated for blepharospasm at Tenon Hospital, BoNT/A was no longer effective in relieving the patient's symptoms, and a partial upper myectomy of the muscle was performed.
View Article and Find Full Text PDFCell Mol Life Sci
December 2024
Univ Angers, INSERM, CNRS, MITOVASC, Équipe CARME, SFR ICAT, F-49000 Angers, France.
Chronic elevated blood pressure impinges on the functioning of multiple organs and therefore harms body homeostasis. Elucidating the protective mechanisms whereby the organism copes with sustained or repetitive blood pressure rises is therefore a topical challenge. Here we address this issue in the adrenal medulla, the master neuroendocrine tissue involved in the secretion of catecholamines, influential hormones in blood pressure regulation.
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