title: V1a vasopressin receptor expression is modulated during myogenic differentiation.
abstract: Neurohypophyseal peptides potently stimulate myogenic differentiation by acting through different receptors of the same family. Here, we show that L6C5 myogenic cells express, at a high density, a single class of V1a Arg8-vasopressin (AVP) receptor. The expression of the vasopressin receptor of type 1a (V1aR) is significantly higher in proliferating myoblasts than in differentiated myotubes. The differentiation-related decrease of V1aR expression was evident both at the mRNA and at the protein level as shown by the reduction of [(3)H]-AVP binding. However, in L6C5 cells transfected with a synthetic construct containing the luciferase gene driven by the 2 kb upstream region of V1aR, we observed a stimulation of the activity of the promoter when the cells were cultured in differentiative medium. The down-regulation of the V1aR correlated with a decreased half-life of its mRNA (half-life 5.86+/-0.74 hr in 10% fetal bovine serum [FBS] versus 3.53+/-0.72 hr in 1% FBS). Cyclosporine A and dexamethasone, but not 5'-azacytidine, treatments of cells in differentiation medium restored the V1aR level to that measured in proliferating L6C5 cells, thus confirming the role of post-transcriptional mechanisms in the modulation of V1aR expression. Taken together, these data show that mRNA stability plays a role in modulating protein expression during the myogenic differentiation process.
authors.affiliation: Dipartimento di Istologia ed Embriologia Medica Università di Roma La Sapienza Via Scarpa 16, 00161 Roma, Italy.
authors.forename: Monica
authors.initials: M
authors.lastname: Alvisi
authors.forename: Valeria
authors.initials: V
authors.lastname: De Arcangelis
authors.forename: Letizia
authors.initials: L
authors.lastname: Ciccone
authors.forename: Valeria
authors.initials: V
authors.lastname: Palombi
authors.forename: Marta
authors.initials: M
authors.lastname: Alessandrini
authors.forename: Georges
authors.initials: G
authors.lastname: Nemoz
authors.forename: Mario
authors.initials: M
authors.lastname: Molinaro
authors.forename: Sergio
authors.initials: S
authors.lastname: Adamo
authors.forename: Fabio
authors.initials: F
authors.lastname: Naro
mesh_terms: D000818:Animals; D001374:Azacitidine / Q000494:pharmacology; D001483:Base Sequence; D015152:Blotting, Northern; D002454:Cell Differentiation; D002478:Cells, Cultured; D016572:Cyclosporine / Q000494:pharmacology; D017931:DNA Primers; D003907:Dexamethasone / Q000494:pharmacology; D015870:Gene Expression / Q000187:drug effects; D006207:Half-Life; D007150:Immunohistochemistry; D009132:Muscles / Q000166:cytology* / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D017483:Receptors, Vasopressin / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D017931:DNA Primers; D012333:RNA, Messenger; D017483:Receptors, Vasopressin; D003907:Dexamethasone; D016572:Cyclosporine; D001374:Azacitidine