Modulation of pro-inflammatory gene expression by nuclear lysophosphatidic acid receptor type-1
| Title | Modulation of pro-inflammatory gene expression by nuclear lysophosphatidic acid receptor type-1 |
| Publication Type | Journal Article |
| Year of Publication | 2003 |
| Authors | Gobeil, F., J, Bernier SG, Vazquez-Tello A, Brault S, Beauchamp MH, Quiniou C, Marrache AM, Checchin D, Sennlaub F, Hou X, Nader M, Bkaily G, Ribeiro-da-Silva A, Goetzl EJ, Chemtob S |
| Journal | J Biol Chem |
| Volume | 278 |
| Pagination | 38875-83 |
| Date Published | Oct 3 |
| ISBN Number | 0021-9258 (Print)0021-9258 (Linking) |
| Accession Number | 12847111 |
| Keywords | *Gene Expression Regulation, *Receptors, G-Protein-Coupled, Androstadienes/pharmacology, Animals, Blotting, Western, Calcium/metabolism, Caveolin 1, Caveolins/metabolism, Cell Nucleus/*metabolism, Cell-Free System/metabolism, Cells, Cultured, Chelating Agents/pharmacology, Clathrin/metabolism, Egtazic Acid/pharmacology, Endothelium, Vascular/cytology, Enzyme Inhibitors/pharmacology, Immunoblotting, Liver/metabolism, Microcirculation, Microscopy, Electron, Microscopy, Fluorescence, Nitric Oxide Synthase Type II, Nitric Oxide Synthase/metabolism, Pertussis Toxin/pharmacology, Phosphatidylinositol 3-Kinases/antagonists & inhibitors, Phospholipases A/metabolism, Phospholipases A2, Precipitin Tests, Protein Binding, Protein-Tyrosine Kinases/metabolism, Rats, Receptors, Cell Surface/*metabolism/*physiology, Receptors, Lysophosphatidic Acid, Subcellular Fractions/metabolism, Swine, Time Factors, Transfection, Tumor Cells, Cultured |
| Abstract | Lysophosphatidic acid (LPA) is a bioactive molecule involved in inflammation, immunity, wound healing, and neoplasia. Its pleiotropic actions arise presumably by interaction with their cell surface G protein-coupled receptors. Herein, the presence of the specific nuclear lysophosphatidic acid receptor-1 (LPA1R) was revealed in unstimulated porcine cerebral microvascular endothelial cells (pCMVECs), LPA1R stably transfected HTC4 rat hepatoma cells, and rat liver tissue using complementary approaches, including radioligand binding experiments, electron- and cryomicroscopy, cell fractionation, and immunoblotting with three distinct antibodies. Coimmunoprecipitation studies in enriched plasmalemmal fractions of unstimulated pCMVEC showed that LPA1Rs are dually sequestrated in caveolin-1 and clathrin subcompartments, whereas in nuclear fractions LPA1R appeared primarily in caveolae. Immunofluorescent assays using a cell-free isolated nuclear system confirmed LPA1R and caveolin-1 co-localization. In pCMVEC, LPA-stimulated increases in cyclooxygenase-2 and inducible nitric-oxide synthase RNA and protein expression were insensitive to caveolea-disrupting agents but sensitive to LPA-generating phospholipase A2 enzyme and tyrosine kinase inhibitors. Moreover, LPA-induced increases in Ca2+ transients and/or iNOS expression in highly purified rat liver nuclei were prevented by pertussis toxin, phosphoinositide 3-kinase/Akt inhibitor wortmannin and Ca2+ chelator and channel blockers EGTA and SK&F96365, respectively. This study describes for the first time the nucleus as a potential organelle for LPA intracrine signaling in the regulation of pro-inflammatory gene expression. |
| URL | http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=12847111 |