title: Sphingosine kinase-1/S1P1 signalling axis negatively regulates mitogenic response elicited by PDGF in mouse myoblasts.
abstract: PDGF is known to be critically implicated in skeletal muscle repair; however its molecular mechanism of action has been only marginally investigated. In this study we show that in mouse myoblasts PDGF transactivates S1P(1) receptor via sphingosine kinase (SK)-1 activation and that this molecular event exerts a negative regulation of the mitogenic effect elicited by this growth factor. Indeed, pharmacological inhibition of S1P(1), or its specific silencing increased PDGF-dependent cell proliferation, whereas S1P(1) overexpression diminished the biological effect. Moreover, the mitogenic response to PDGF was enhanced by pharmacological inhibition of SK activity as well as specific silencing of SK1 but not SK2. Furthermore, ERK1/2 signalling pathway was found to be upstream of the observed attenuation of PDGF-induced cell proliferation. Interestingly, PDGF-directed engagement of S1P(1) exerted also a positive modulatory action of the growth factor-dependent cell motility. The here highlighted dual role of S1P(1)-mediated signalling in response to myoblast challenge with PDGF is likely important to guarantee the fine control of the biological response to this growth factor, finalized to efficient repopulation of skeletal muscle after damage, where a tight balance between proliferation and migration of tissue progenitor cells is required.
authors.affiliation: Dipartimento di Scienze Biochimiche, Universita; di Firenze, 50134 Firenze, Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Nincheri
authors.forename: Caterina
authors.initials: C
authors.lastname: Bernacchioni
authors.forename: Francesca
authors.initials: F
authors.lastname: Cencetti
authors.forename: Chiara
authors.initials: C
authors.lastname: Donati
authors.forename: Paola
authors.initials: P
authors.lastname: Bruni
mesh_terms: D000818:Animals; D002460:Cell Line; D002465:Cell Movement; D049109:Cell Proliferation; D051379:Mice; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D008938:Mitosis; D032446:Myoblasts / Q000166:cytology / Q000378:metabolism*; D010766:Phosphorylation; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D010982:Platelet-Derived Growth Factor / Q000494:pharmacology*; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000378:metabolism; D020797:Receptor, Platelet-Derived Growth Factor beta / Q000378:metabolism; D049349:Receptors, Lysosphingolipid / Q000378:metabolism*; D015398:Signal Transduction; D000099157:Sphingosine Kinase
chemical_list: D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D017853:Phosphotransferases (Alcohol Group Acceptor); D010982:Platelet-Derived Growth Factor; D034741:RNA, Small Interfering; D020797:Receptor, Platelet-Derived Growth Factor beta; D049349:Receptors, Lysosphingolipid; D000099157:Sphingosine Kinase