title: The role of lysophosphatidic acid receptors in phenotypic modulation of vascular smooth muscle cells.
abstract: Lysophosphatidic acid (LPA) is a bioactive lipid with diverse physiological effects via activation of G protein-coupled receptors (GPCRs). It has been implicated as a specific dedifferentiation factors that can promote phenotypic modulation of cultured vascular smooth muscle cells (VSMCs) which is critically involved in various vascular disease. However, the role of LPA receptors and details of their signaling in LPA induced phenotypic modulation are largely unexplored. In this study we detect the expression of LPA1 and LPA3 in rat aortic smooth muscle cells (RASMCs). LPA promoted RASMCs phenotypic modulation in a dose-dependent manner and coordinated induced the phosphorylation of p38 mitogen-activated protein kinase (p38MAPK) and extracellular signal-regulated kinase (ERK). LPA-induced cell phenotypic modulation was significantly inhibited by specific LPA1/LPA3-receptor antagonist dioctyl-glycerol pyrophosphate (DGPP8:0) at concentration, but this inhibitive effect was lost when the antagonist was coadministered with a highly selective LPA3 agonist,1-oleoyl-2-Omethyl-rac-glycero-phosphothionate (OMPT). In addition, pertussis toxin (PTX), a Gi protein inhibitor had little affect on the LPA-induced phenotypic modulation in RASMC. These data suggest that LPA-induced phenotypic modulation is mediated through the PTX-insensitive G-protein(s), possibly Gq-coupled LPA3 receptor.
authors.affiliation: School of Clinical Medicine, Southeast University, Nanjing 21009, China.
authors.forename: Zhibin
authors.initials: Z
authors.lastname: Zhou
authors.forename: Jianping
authors.initials: J
authors.lastname: Niu
authors.forename: Zhijun
authors.initials: Z
authors.lastname: Zhang
mesh_terms: D000818:Animals; D001011:Aorta / Q000166:cytology; D011756:Diphosphates / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D019204:GTP-Binding Proteins / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects; D005990:Glycerol / Q000031:analogs & derivatives / Q000494:pharmacology; D008246:Lysophospholipids / Q000494:pharmacology; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D009131:Muscle, Smooth, Vascular / Q000166:cytology*; D032389:Myocytes, Smooth Muscle / Q000166:cytology / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D037342:Pertussis Toxin / Q000494:pharmacology; D010641:Phenotype; D010766:Phosphorylation / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D049368:Receptors, Lysophosphatidic Acid / Q000235:genetics / Q000378:metabolism*
chemical_list: D011756:Diphosphates; D008246:Lysophospholipids; D049368:Receptors, Lysophosphatidic Acid; C408642:diacylglycerol pyrophosphate; D037342:Pertussis Toxin; D020928:Mitogen-Activated Protein Kinases; D019204:GTP-Binding Proteins; D005990:Glycerol; C032881:lysophosphatidic acid