title: AM966, an Antagonist of Lysophosphatidic Acid Receptor 1, Increases Lung Microvascular Endothelial Permeability through Activation of Rho Signaling Pathway and Phosphorylation of VE-Cadherin.
abstract: Maintenance of pulmonary endothelial barrier integrity is important for reducing severity of lung injury. Lysophosphatidic acid (LPA) regulates cell motility, cytoskeletal rearrangement, and cell growth. Knockdown of LPA receptor 1 (LPA1) has been shown to mitigate lung injury and pulmonary fibrosis. AM966, an LPA1 antagonist exhibiting an antifibrotic property, has been considered to be a future antifibrotic medicine. Here, we report an unexpected effect of AM966, which increases lung endothelial barrier permeability. An electric cell-substrate sensing (ECIS) system was used to measure permeability in human lung microvascular endothelial cells (HLMVECs). AM966 decreased the transendothelial electrical resistance (TEER) value immediately in a dose-dependent manner. VE-cadherin and f-actin double immunostaining reveals that AM966 increases stress fibers and gap formation between endothelial cells. AM966 induced phosphorylation of myosin light chain (MLC) through activation of RhoA/Rho kinase pathway. Unlike LPA treatment, AM966 had no effect on phosphorylation of extracellular signal-regulated kinases (Erk). Further, in LPA1 silencing cells, we observed that AM966-increased lung endothelial permeability as well as phosphorylation of VE-cadherin and focal adhesion kinase (FAK) were attenuated. This study reveals that AM966 induces lung endothelial barrier dysfunction, which is regulated by LPA1-mediated activation of RhoA/MLC and phosphorylation of VE-cadherin.
authors.affiliation: Acute Lung Injury Center of Excellence, Division of Pulmonary, Asthma, and Critical Care Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, PA 15213, USA; Third Affiliated Hospital of Xiangya Medical School, Changsha, Hunan 410013, China.
authors.forename: Junting
authors.initials: J
authors.lastname: Cai
authors.affiliation: Acute Lung Injury Center of Excellence, Division of Pulmonary, Asthma, and Critical Care Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, PA 15213, USA.
authors.forename: Jianxin
authors.identifier: 0000-0003-0385-440X
authors.initials: J
authors.lastname: Wei
authors.affiliation: Acute Lung Injury Center of Excellence, Division of Pulmonary, Asthma, and Critical Care Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, PA 15213, USA; Department of General Surgery, The First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning 116011, China.
authors.forename: Shuang
authors.identifier: 0000-0002-5698-0146
authors.initials: S
authors.lastname: Li
authors.affiliation: Acute Lung Injury Center of Excellence, Division of Pulmonary, Asthma, and Critical Care Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, PA 15213, USA.
authors.forename: Tomeka
authors.initials: T
authors.lastname: Suber
authors.affiliation: Acute Lung Injury Center of Excellence, Division of Pulmonary, Asthma, and Critical Care Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, PA 15213, USA.
authors.forename: Jing
authors.identifier: 0000-0002-0211-9289
authors.initials: J
authors.lastname: Zhao
mesh_terms: D015703:Antigens, CD / Q000378:metabolism*; D015820:Cadherins / Q000378:metabolism*; D002199:Capillary Permeability / Q000187:drug effects*; D002219:Carbamates / Q000494:pharmacology*; D002460:Cell Line; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D051416:Focal Adhesion Protein-Tyrosine Kinases / Q000378:metabolism; D006801:Humans; D008168:Lung / Q000098:blood supply*; D010648:Phenylacetates / Q000494:pharmacology*; D010766:Phosphorylation / Q000187:drug effects; D049368:Receptors, Lysophosphatidic Acid / Q000037:antagonists & inhibitors* / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects; D020742:rhoA GTP-Binding Protein / Q000378:metabolism*; D000099152:Cadherin 5; D001713:Biphenyl Compounds
chemical_list: D015703:Antigens, CD; D015820:Cadherins; D002219:Carbamates; D048049:Extracellular Signal-Regulated MAP Kinases; D051416:Focal Adhesion Protein-Tyrosine Kinases; D010648:Phenylacetates; D049368:Receptors, Lysophosphatidic Acid; D020742:rhoA GTP-Binding Protein; D000099152:Cadherin 5; C553744:(4'-(4-(1-(2-chlorophenyl)ethoxycarbonylamino)-3-methylisoxazol-5-yl)biphenyl-4-yl)acetic acid; D001713:Biphenyl Compounds