Rho kinase-induced nuclear translocation of ERK1/ERK2 in smooth muscle cell mitogenesis caused by serotonin.
There is now considerable evidence supporting a mitogenic action of serotonin (5-HT) on vascular smooth muscle cells (SMC) that might participate in pulmonary hypertension (PH). Our previous studies have demonstrated that 5-HT-induced proliferation depends on the generation of reactive oxygen species and activation of extracellular signal-regulated kinase (ERK) 1/ERK2. Activation of Rho kinase (ROCK) in SMC also may be important in PH. We undertook the present study to assess the role of Rho A/ROCK and its possible relation to ERK1/ERK2 in 5-HT-induced pulmonary artery SMC proliferation. We found that this stimulation of SMC proliferation requires Rho A/ROCK as inhibition with Y27632, a ROCK inhibitor, or dominant negative (DN) mutant Rho A blocks 5-HT-induced proliferation, cyclin D1 expression, phosphorylation of Elk, and the DNA binding of transcription factors, Egr-1 and GATA-4. 5-HT activated ROCK, and the activation was blocked by GR 55562 and GR127935, 5-HT 1B/1D receptor antagonists, but not by serotonin transport (SERT) inhibitors. Activation of Rho kinase by 5-HT was independent of activation of ERK1/ERK2, and 5-HT activated ERK1/ERK2 independently of ROCK. Treatment of SMC with Y27632 and expression of DNRho A in cells blocked translocation of ERK1/ERK2 to the cellular nucleus. Depolymerization of actin with cytochalasin D (CD) and latrunculin B (latB) failed to block the translocation of ERK, suggesting that the actin cytoskeleton does not participate in the translocation. The studies show for the first time to our knowledge combinational action of SERT and a 5-HT receptor in SMC growth and Rho A/ROCK participation in 5-HT receptor 1B/1D-mediated mitogenesis of vascular SMCs through an effect on cytoplasmic to nuclear translocation of ERK1/ERK2.
Tufts-New England Medical Center, Pulmonary, Critical Care and Sleep Division, Tupper Research Institute, Boston, Mass 02111, USA.
Yinglin
Y
Liu
Yuichiro J
YJ
Suzuki
Regina M
RM
Day
Barry L
BL
Fanburg
D021581:Active Transport, Cell Nucleus; D000577:Amides / Q000494:pharmacology; D000818:Animals; D001549:Benzamides / Q000494:pharmacology; D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000494:pharmacology; D002417:Cattle; D002455:Cell Division; D002478:Cells, Cultured / Q000187:drug effects / Q000378:metabolism; D015638:Cytochalasin D / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D047908:Intracellular Signaling Peptides and Proteins; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism*; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism*; D009131:Muscle, Smooth, Vascular / Q000166:cytology*; D032389:Myocytes, Smooth Muscle / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D043263:Myosin-Light-Chain Phosphatase / Q000378:metabolism; D010069:Oxadiazoles / Q000494:pharmacology; D010750:Phosphoproteins / Q000378:metabolism; D010766:Phosphorylation; D010879:Piperazines / Q000494:pharmacology; D011499:Protein Processing, Post-Translational; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000502:physiology*; D021122:Protein Subunits / Q000378:metabolism; D021381:Protein Transport / Q000502:physiology*; D011651:Pulmonary Artery; D011725:Pyridines / Q000494:pharmacology; D044302:Receptor, Serotonin, 5-HT1B / Q000187:drug effects / Q000502:physiology*; D044346:Receptor, Serotonin, 5-HT1D / Q000187:drug effects / Q000502:physiology*; D011993:Recombinant Fusion Proteins / Q000502:physiology; D012701:Serotonin / Q000502:physiology*; D058829:Serotonin 5-HT1 Receptor Antagonists; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology*; D013844:Thiazoles / Q000494:pharmacology; D053778:Thiazolidines; D014157:Transcription Factors / Q000378:metabolism; D054460:rho-Associated Kinases
D000577:Amides; D001549:Benzamides; D019086:Bridged Bicyclo Compounds, Heterocyclic; D047908:Intracellular Signaling Peptides and Proteins; D010069:Oxadiazoles; D010750:Phosphoproteins; D010879:Piperazines; D021122:Protein Subunits; D011725:Pyridines; D044302:Receptor, Serotonin, 5-HT1B; D044346:Receptor, Serotonin, 5-HT1D; D011993:Recombinant Fusion Proteins; D058829:Serotonin 5-HT1 Receptor Antagonists; D013844:Thiazoles; D053778:Thiazolidines; D014157:Transcription Factors; C108830:Y 27632; C103477:3-(3-(dimethylamino)propyl)-4-hydroxy-N-(4-(4-pyridinyl)phenyl)benzamide; D015638:Cytochalasin D; C090701:GR 127935; D012701:Serotonin; D017346:Protein Serine-Threonine Kinases; D054460:rho-Associated Kinases; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D043263:Myosin-Light-Chain Phosphatase; C037068:latrunculin B