title: The endocannabinoid 2-AG controls skeletal muscle cell differentiation via CB1 receptor-dependent inhibition of Kv7 channels.
abstract: Little is known of the involvement of endocannabinoids and cannabinoid receptors in skeletal muscle cell differentiation. We report that, due to changes in the expression of genes involved in its metabolism, the levels of the endocannabinoid 2-arachidonoylglycerol (2-AG) are decreased both during myotube formation in vitro from murine C2C12 myoblasts and during mouse muscle growth in vivo. The endocannabinoid, as well as the CB1 agonist arachidonoyl-2-chloroethylamide, prevent myotube formation in a manner antagonized by CB1 knockdown and by CB1 antagonists, which, per se, instead stimulate differentiation. Importantly, 2-AG also inhibits differentiation of primary human satellite cells. Muscle fascicles from CB1 knockout embryos contain more muscle fibers, and postnatal mice show muscle fibers of an increased diameter relative to wild-type littermates. Inhibition of Kv7.4 channel activity, which plays a permissive role in myogenesis and depends on phosphatidylinositol 4,5-bisphosphate (PIP2), underlies the effects of 2-AG. We find that CB1 stimulation reduces both total and Kv7.4-bound PIP2 levels in C2C12 cells and inhibits Kv7.4 currents in transfected CHO cells. We suggest that 2-AG is an endogenous repressor of myoblast differentiation via CB1-mediated inhibition of Kv7.4 channels.
authors.affiliation: Endocannabinoid Research Group, Institute of Biomolecular Chemistry, National Council of Research (Consiglio Nazionale delle Ricerche), 80078 Pozzuoli, Italy;
authors.forename: Fabio A
authors.initials: FA
authors.lastname: Iannotti
authors.affiliation: Endocannabinoid Research Group, Institute of Biomolecular Chemistry, National Council of Research (Consiglio Nazionale delle Ricerche), 80078 Pozzuoli, Italy;
authors.forename: Cristoforo
authors.initials: C
authors.lastname: Silvestri
authors.affiliation: Endocannabinoid Research Group, Institute of Biomolecular Chemistry, National Council of Research (Consiglio Nazionale delle Ricerche), 80078 Pozzuoli, Italy;
authors.forename: Enrico
authors.initials: E
authors.lastname: Mazzarella
authors.affiliation: Endocannabinoid Research Group, Institute of Biomolecular Chemistry, National Council of Research (Consiglio Nazionale delle Ricerche), 80078 Pozzuoli, Italy;
authors.forename: Andrea
authors.initials: A
authors.lastname: Martella
authors.affiliation: Department of Medical Biochemistry and Biophysics, Karolinska Institutet, SE-17177 Stockholm, Sweden;Department of Molecular Neurosciences, Center for Brain Research, Medical University of Vienna, A-1090 Vienna, Austria;
authors.forename: Daniela
authors.initials: D
authors.lastname: Calvigioni
authors.affiliation: Endocannabinoid Research Group, Institute of Biomolecular Chemistry, National Council of Research (Consiglio Nazionale delle Ricerche), 80078 Pozzuoli, Italy;
authors.forename: Fabiana
authors.initials: F
authors.lastname: Piscitelli
authors.affiliation: Department of Medicine and Health Sciences, University of Molise, 86100 Campobasso, Italy; and.
authors.forename: Paolo
authors.initials: P
authors.lastname: Ambrosino
authors.affiliation: Endocannabinoid Research Group, Institute of Biomolecular Chemistry, National Council of Research (Consiglio Nazionale delle Ricerche), 80078 Pozzuoli, Italy;
authors.forename: Stefania
authors.initials: S
authors.lastname: Petrosino
authors.affiliation: Department of Physiology and Cell Physiology Research Group of the Hungarian Academy of Sciences, University Medical School of Debrecen, 4032, Debrecen, Hungary.
authors.forename: Gabriella
authors.initials: G
authors.lastname: Czifra
authors.affiliation: Department of Physiology and Cell Physiology Research Group of the Hungarian Academy of Sciences, University Medical School of Debrecen, 4032, Debrecen, Hungary.
authors.forename: Tamás
authors.initials: T
authors.lastname: Bíró
authors.affiliation: Department of Medical Biochemistry and Biophysics, Karolinska Institutet, SE-17177 Stockholm, Sweden;Department of Molecular Neurosciences, Center for Brain Research, Medical University of Vienna, A-1090 Vienna, Austria;
authors.forename: Tibor
authors.initials: T
authors.lastname: Harkany
authors.affiliation: Department of Medicine and Health Sciences, University of Molise, 86100 Campobasso, Italy; and.
authors.forename: Maurizio
authors.initials: M
authors.lastname: Taglialatela
authors.affiliation: Endocannabinoid Research Group, Institute of Biomolecular Chemistry, National Council of Research (Consiglio Nazionale delle Ricerche), 80078 Pozzuoli, Italy; vdimarzo@icb.cnr.it.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Di Marzo
mesh_terms: D000818:Animals; D001095:Arachidonic Acids / Q000737:chemistry*; D016466:CHO Cells; D002454:Cell Differentiation; D049109:Cell Proliferation; D006224:Cricetinae; D003412:Cricetulus; D063388:Endocannabinoids / Q000737:chemistry*; D020868:Gene Silencing; D005989:Glycerides / Q000737:chemistry*; D006801:Humans; D007295:Inositol Phosphates / Q000378:metabolism; D051656:KCNQ Potassium Channels / Q000378:metabolism*; D051379:Mice; D024510:Muscle Development / Q000235:genetics; D018485:Muscle Fibers, Skeletal / Q000378:metabolism; D018482:Muscle, Skeletal / Q000166:cytology / Q000378:metabolism; D032448:Myoblasts, Skeletal / Q000166:cytology*; D043884:Receptor, Cannabinoid, CB1 / Q000378:metabolism*; D043885:Receptor, Cannabinoid, CB2 / Q000378:metabolism; D015398:Signal Transduction; D012826:Silicone Elastomers / Q000737:chemistry; D014162:Transfection
chemical_list: D001095:Arachidonic Acids; D063388:Endocannabinoids; D005989:Glycerides; D007295:Inositol Phosphates; D051656:KCNQ Potassium Channels; C117367:KCNQ4 protein, human; C492167:Kcnq4 protein, mouse; D043884:Receptor, Cannabinoid, CB1; D043885:Receptor, Cannabinoid, CB2; D012826:Silicone Elastomers; C424442:noladin ether; C006194:aminoethyl-aminopropyl-trimethoxysilane; C094503:glyceryl 2-arachidonate; C066454:inositol 4,5-bisphosphate