Pulmonary endothelial cell barrier enhancement by novel FTY720 analogs: methoxy-FTY720, fluoro-FTY720, and β-glucuronide-FTY720.

TitlePulmonary endothelial cell barrier enhancement by novel FTY720 analogs: methoxy-FTY720, fluoro-FTY720, and β-glucuronide-FTY720.
Publication TypeJournal Article
Year of Publication2015
AuthorsCamp SM, Chiang ET, Sun C, Usatyuk PV, Bittman R, Natarajan V, Garcia JGN, Dudek SM
JournalChem Phys Lipids
Date Published2015 Oct
ISSN Number1873-2941
KeywordsCalcium, Cell Line, Endothelial Cells, Extracellular Signal-Regulated MAP Kinases, Fingolimod Hydrochloride, Fluorides, Glucuronides, Humans, Lysophospholipids, Microscopy, Fluorescence, Permeability, Phosphorylation, Pulmonary Artery, Signal Transduction, Sphingosine

<p>Effective therapeutic agents are lacking for the prevention and reversal of vascular leak, a frequent pathophysiologic result of inflammatory processes such as acute respiratory distress syndrome (ARDS) and sepsis. We previously demonstrated the potent barrier-enhancing effects of related compounds sphingosine 1-phosphate (S1P), the pharmaceutical agent FTY720, and its analog (S)-FTY720 phosphonate (Tys) in models of inflammatory lung injury. In this study, we characterize additional novel FTY720 analogs for their potential to reduce vascular leak as well as utilize them as tools to better understand the mechanisms by which this class of agents modulates permeability. Transendothelial resistance (TER) and labeled dextran studies demonstrate that (R)-methoxy-FTY720 ((R)-OMe-FTY), (R)/(S)-fluoro-FTY720 (FTY-F), and β-glucuronide-FTY720 (FTY-G) compounds display in vitro barrier-enhancing properties comparable or superior to FTY720 and S1P. In contrast, the (S)-methoxy-FTY720 ((S)-OMe-FTY) analog disrupts lung endothelial cell (EC) barrier integrity in TER studies in association with actin stress fiber formation and robust intracellular calcium release, but independent of myosin light chain or ERK phosphorylation. Additional mechanistic studies with (R)-OMe-FTY, FTY-F, and FTY-G suggest that lung EC barrier enhancement is mediated through lipid raft signaling, Gi-linked receptor coupling to downstream tyrosine phosphorylation events, and S1PR1-dependent receptor ligation. These results provide important mechanistic insights into modulation of pulmonary vascular barrier function by FTY720-related compounds and highlight common signaling events that may assist the development of novel therapeutic tools in the prevention or reversal of the pulmonary vascular leak that characterizes ARDS.</p>

Alternate JournalChem. Phys. Lipids
PubMed ID26272033
PubMed Central IDPMC4655823
Grant ListP01 HL058064 / HL / NHLBI NIH HHS / United States
P01 HL098050 / HL / NHLBI NIH HHS / United States
P01HL 58064 / HL / NHLBI NIH HHS / United States
P01HL 98050 / HL / NHLBI NIH HHS / United States