title: Sphingosine 1-phosphate inhibits cell migration in C2C12 myoblasts.
abstract: This study shows that sphingosine 1-phosphate (S1P) exerts an anti-migratory action in C2C12 myoblasts by reducing directional cell motility and fully abrogating the chemotactic response to insulin-like growth factor-1. The anti-migratory response to S1P required ligation to S1P(2), being attenuated in myoblasts where the receptor was down-regulated by specific antisense oligodeoxyribonucleotides or small interfering RNA (siRNA) and conversely potentiated in S1P(2)-overexpressing myoblasts. The investigation of RhoA and Rac GTPases, critically implicated in cell motility regulation, demonstrated that RhoA was rapidly activated by S1P, while Rac1 was unaffected within the first 5 min but stimulated thereafter. RhoA, but not Rac activation, was identified as a S1P(2)-dependent pathway in experiments in which receptor expression was attenuated by siRNA treatment or up-regulated by S1P(2)-encoding plasmid transfection. Finally, by expression of the dominant negative mutant of RhoA, the GTPase was found implicated in the anti-migratory action of S1P, whereas modulation of Rac1 functionality unaffected the anti-chemotactic effect of S1P, ruling out a role for this protein in the biological response. Since S1P was previously shown to inhibit myoblast proliferation and stimulate myogenesis, the here identified novel biological activity is in favour of a complex physiological role of the sphingolipid in the process of muscle repair.
authors.affiliation: Dipartimento di Scienze Biochimiche, Università degli Studi di Firenze, Viale G.B. Morgagni 50, 50134 Firenze, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Becciolini
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Meacci
authors.forename: Chiara
authors.initials: C
authors.lastname: Donati
authors.forename: Francesca
authors.initials: F
authors.lastname: Cencetti
authors.forename: Elena
authors.initials: E
authors.lastname: Rapizzi
authors.forename: Paola
authors.initials: P
authors.lastname: Bruni
mesh_terms: D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D002465:Cell Movement / Q000187:drug effects*; D008246:Lysophospholipids / Q000494:pharmacology*; D051379:Mice; D032446:Myoblasts / Q000187:drug effects / Q000502:physiology*; D009838:Oligodeoxyribonucleotides; D016133:Polymerase Chain Reaction; D049349:Receptors, Lysosphingolipid / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D013110:Sphingosine / Q000031:analogs & derivatives* / Q000494:pharmacology; D014162:Transfection
chemical_list: D008246:Lysophospholipids; D009838:Oligodeoxyribonucleotides; D049349:Receptors, Lysosphingolipid; C060506:sphingosine 1-phosphate; D013110:Sphingosine