title: The 2-arachidonoylglycerol effect on myosin light chain phosphorylation in human platelets.
abstract: In human platelets the endocannabinoid 2-arachidonoylglycerol (2-AG) stimulates some important pathways leading to thromboxane B2 formation, calcium intracellular elevation, ATP secretion and actin polymerisation. The aim of the present study was to examine the 2-AG effect on myosin light chain (MLC) phosphorylation and to investigate the mechanisms involved. We demonstrated that 2-AG induced a rapid MLC phosphorylation, stimulating both the RhoA kinase (ROCK) and MLC kinase (MLCK) in a dose and time-dependent manner. In addition MLC phosphorylation was strengthened through the MLC phosphatase inhibition. MLC phosphatase inhibition was accomplished through the RhoA/ROCK and protein kinase C mediated phosphorylation of MLC phosphatase inhibiting subunits MYPT1 and CPI-17. The presence of CB1 receptor in human platelets and the involvement of CB1 receptor in MLC phosphorylation and MLC phosphatase inhibition was shown.
authors.affiliation: Department of Pharmacy, Biochemistry Lab, University of Genoa, Viale Benedetto XV 3, Genoa, Italy.
authors.forename: Maria Grazia
authors.initials: MG
authors.lastname: Signorello
authors.forename: Enrica
authors.initials: E
authors.lastname: Giacobbe
authors.forename: Mario
authors.initials: M
authors.lastname: Passalacqua
authors.forename: Giuliana
authors.initials: G
authors.lastname: Leoncini
mesh_terms: D001095:Arachidonic Acids / Q000494:pharmacology*; D001792:Blood Platelets / Q000737:chemistry / Q000187:drug effects*; D048430:Cell Shape; D048429:Cell Size; D063388:Endocannabinoids / Q000494:pharmacology*; D005455:Fluorescent Antibody Technique; D005989:Glycerides / Q000494:pharmacology*; D006801:Humans; D018613:Microscopy, Confocal; D018994:Myosin Light Chains / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects*; D043884:Receptor, Cannabinoid, CB1 / Q000737:chemistry
chemical_list: D001095:Arachidonic Acids; D063388:Endocannabinoids; D005989:Glycerides; D018994:Myosin Light Chains; D043884:Receptor, Cannabinoid, CB1; C094503:glyceryl 2-arachidonate