iloprost and butaprost

Interleukin-1 (IL-1alpha) induced inflammatory and pro-fibrotic responses in human lung fibroblasts are mediated by activation of MAPK and NFkappaB pathways. The purpose of the present study was to broadly profile the activity of a variety of compounds which function as inhibitors of these key signaling pathways that may affect IL-1alpha mediated gene changes. A reference set of genes was derived from microarray analysis of IL-1alpha stimulated cells. The genes were chosen to provide a range of expression profiles which serve to represent the actions of the underlying signaling network. We show that G(s)-coupled receptor agonists have a unique pattern of activity as represented by their impact on IL-1alpha dependent gene changes. These effects were not mimicked by direct inhibitors of p38, JNK, MEK or IKK but were mimicked by forskolin and cAMP analogs. These findings indicate that cAMP/PKA serves as a point of convergence for regulation of IL-1alpha responses by multiple G(s)-coupled receptors and regulates IL-1alpha responses by a distinct mechanism that does not solely involve direct inhibition of p38, JNK, MEK or IKK. The data also point to a potentially useful paradigm wherein monitoring of a small subset of genes is sufficient to identify pathway activity of novel compounds.

Topics: Alprostadil; Anti-Ulcer Agents; Calcium; Cells, Cultured; Cyclic AMP; Cyclic AMP-Dependent Protein Kinases; Enzyme Inhibitors; Fibroblasts; Gene Expression Profiling; Humans; Hydantoins; I-kappa B Kinase; Iloprost; Interleukin-1alpha; JNK Mitogen-Activated Protein Kinases; Lung; MAP Kinase Kinase Kinases; Misoprostol; Oligonucleotide Array Sequence Analysis; p38 Mitogen-Activated Protein Kinases; Platelet Aggregation Inhibitors; Prostaglandins E, Synthetic; Receptors, G-Protein-Coupled; Receptors, Prostaglandin; Signal Transduction

There is concern that cyclooxygenase (COX)-2 inhibitors may promote atherothrombosis by inhibiting vascular formation of prostacyclin (PGI2) and an increased thrombotic risk of COX-2 inhibitors has been reported. It is widely accepted that the prothrombotic effects of COX-2 inhibitors can be explained by the removal of platelet-inhibitory PGI2. Using microarray chip technology, we have previously demonstrated that thrombomodulin (TM) mRNA is upregulated in cultured human coronary artery smooth muscle cells by the stable prostacyclin mimetic iloprost. This study is the first to demonstrate a stimulation of the expression of functionally active thrombomodulin in human smooth muscle cells by prostaglandins, endogenously formed via the COX-2 pathway. Because TM is an important inhibitor of blood coagulation, these findings provide a novel platelet-independent mechanism to explain the prothrombotic effects of COX-2 inhibitors. The full text of this article is available online at http://circres.ahajournals.org.

Topics: Alprostadil; Blood Coagulation; Bucladesine; Carotid Artery Diseases; Carotid Artery, Internal; Cells, Cultured; Colforsin; Coronary Vessels; Culture Media, Serum-Free; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Cyclooxygenase Inhibitors; Diclofenac; Dinoprostone; Epoprostenol; Etoricoxib; Gene Expression Profiling; Gene Expression Regulation; Humans; Iloprost; Isoquinolines; Mammary Arteries; Membrane Proteins; Models, Biological; Myocytes, Smooth Muscle; Oligonucleotide Array Sequence Analysis; Prostaglandin-Endoperoxide Synthases; Prostaglandins; Pyridines; Receptors, Prostaglandin; Receptors, Prostaglandin E; Receptors, Prostaglandin E, EP3 Subtype; RNA, Messenger; Saphenous Vein; Second Messenger Systems; Sulfonamides; Sulfones; Tetradecanoylphorbol Acetate; Thrombomodulin; Thrombophilia; Vasodilator Agents

Hyaluronic acid (HA) is a prominent constituent of the extracellular matrix of atherosclerotic vascular lesions in humans known to modulate vascular smooth muscle phenotype. The regulation of HA synthesis by vasodilatory prostaglandins was analyzed in human arterial smooth muscle cells (SMCs). The prostacyclin analogue, iloprost (100 nmol/L), markedly increased pericellular formation of HA coats and HA secretion into the cell culture medium in human arterial SMCs (8.7+/-1.6-fold). Expression of HA synthase 2 (HAS2) was determined by semiquantitative RT-PCR and found to be strongly upregulated at concentrations of iloprost between 1 and 100 nmol/L after 3 hours. Furthermore, endogenous cyclooxygenase-2 (COX2) activity was required for basal expression of HAS2 mRNA in SMCs in vitro. Total HA secretion in response to iloprost was markedly decreased by RNA interference (RNAi), specific for HAS2. In addition, siRNA targeting HAS2 strongly increased the spreading of human SMCs compared with mock-transfected cells. HAS2 mRNA levels were also stimulated by a selective prostacyclin receptor (IP) agonist, cicaprost (10 nmol/L), prostaglandin E(2) (10 nmol/L), and the EP(2) receptor agonist, butaprost (1 micromol/L). Induction of HAS2 mRNA and HA synthesis by prostaglandins was mimicked by stable cAMP analogues and forskolin. In human atherectomy specimens from the internal carotid artery, HA deposits and COX2 expression colocalized frequently. In addition, strong EP(2) receptor expression was detected in SMCs in HA-rich areas. Therefore, upregulation of HAS2 expression via EP(2) and IP receptors might contribute to the accumulation of HA during human atherosclerosis, thereby mediating proatherosclerotic functions of COX2.

Topics: 6-Ketoprostaglandin F1 alpha; Acetophenones; Alprostadil; Arteriosclerosis; Becaplermin; Benzopyrans; Bucladesine; Carotid Artery Diseases; Carotid Artery, Internal; Cells, Cultured; Colforsin; Cyclic AMP; Cyclooxygenase 2; Enzyme Induction; Epoprostenol; Extracellular Matrix; Glucuronosyltransferase; Humans; Hyaluronan Synthases; Hyaluronic Acid; Iloprost; Indoles; Isoenzymes; Isoquinolines; Macrophages; Maleimides; Membrane Proteins; Muscle Cells; Muscle, Smooth, Vascular; Pertussis Toxin; Platelet-Derived Growth Factor; Prostaglandin-Endoperoxide Synthases; Proto-Oncogene Proteins c-sis; Receptors, Prostaglandin E; Receptors, Prostaglandin E, EP2 Subtype; RNA, Messenger; RNA, Small Interfering; Sulfonamides; Vasodilator Agents

1. Since the role of prostanoid receptors in intestinal peristalsis is largely unknown, the peristaltic motor effects of some prostaglandin (DP, EP, IP), thromboxane (TP) and leukotriene (LT) receptor agonists and antagonists were investigated. 2. Propulsive peristalsis in fluid-perfused segments from the guinea-pig small intestine was triggered by a rise of the intraluminal pressure and recorded via the intraluminal pressure changes associated with the peristaltic waves. Alterations of distension sensitivity were deduced from alterations of the peristaltic pressure threshold and modifications of peristaltic performance were reflected by modifications of the amplitude, maximal acceleration and residual baseline pressure of the peristaltic waves. 3. Four categories of peristaltic motor effects became apparent: a decrease in distension sensitivity and peristaltic performance as induced by the EP1/EP3 receptor agonist sulprostone and the TP receptor agonist U-46619 (1-1000 nM); a decrease in distension sensitivity without a major change in peristaltic performance as induced by PGD(2) (3-300 nM) and LTD(4) (10-100 nM); a decrease in peristaltic performance without a major change in distension sensitivity as induced by PGE(1), PGE(2) (1-1000 nM) and the EP1/IP receptor agonist iloprost (1-100 nM); and a decrease in peristaltic performance associated with an increase in distension sensitivity as induced by the EP2 receptor agonist butaprost (1-1000 nM). The DP receptor agonist BW-245 C (1-1000 nM) was without effect. 4. The peristaltic motor action of sulprostone remained unchanged by the EP1 receptor antagonist SC-51089 (1 micro M) and the DP/EP1/EP2 receptor antagonist AH-6809 (30 micro M), whereas that of U-46619 and LTD(4) was prevented by the TP receptor antagonist SQ-29548 (10 micro M) and the cysteinyl-leukotriene(1) (cysLT(1)) receptor antagonist tomelukast (10 micro M), respectively. 5. These observations and their pharmacological analysis indicate that activation of EP2, EP3, IP, TP and cysLT(1) receptors, but not DP receptors, modulate intestinal peristalsis in a receptor-selective manner, whereas activation of EP1 seems to be without influence on propulsive peristalsis. In a wider perspective it appears as if the effect of prostanoid receptor agonists to induce diarrhoea is due to their prosecretory but not peristaltic motor action.

Topics: 15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; Alprostadil; Animals; Bridged Bicyclo Compounds, Heterocyclic; Dinoprostone; Dose-Response Relationship, Drug; Fatty Acids, Unsaturated; Female; Guinea Pigs; Hydantoins; Hydrazines; Iloprost; In Vitro Techniques; Intestine, Small; Leukotriene Antagonists; Leukotriene D4; Male; Oxazepines; Peristalsis; Prostaglandin D2; Prostaglandins A; Receptors, Leukotriene; Receptors, Prostaglandin; Xanthenes; Xanthones; Yohimbine

Using monolayers of bovine aortic endothelial cells (BAEC) in modified Boyden chambers, we examined the role of prostaglandins (PGs) in the bradykinin (BK)-induced increase of albumin permeability. BK induced a concentration-dependent increase of the permeability of BAEC, which reached 49.9 +/- 1% at the concentration of 10(-8) M. Two inhibitors of the prostaglandin G/H synthase, indomethacin (2.88 microM) and ibuprofen (10 microM), potentiated BK-induced permeability 1.8- and 3.9-fold, respectively. Exogenously administered PGE2 and iloprost, a stable analog of prostacyclin, attenuated the effect of BK in a concentration-dependent manner. Butaprost equally reduced the effect of BK, suggesting the participation of the EP2 receptor in this phenomenon. However, the EP4-selective antagonist AH-23848 did not significantly inhibit the protective effect of PGE2. The inhibitory effect of PGE2 was reversed by the adenylate cyclase inhibitor MDL-12330A (10 microM). These results suggest that BK-induced increase of permeability of BAEC monolayer to (125)I-labeled albumin is negatively regulated by PGs. This postulated autocrine activity of PGs may involve an increase in the intracellular level of cAMP.

Topics: Adrenergic beta-Agonists; Albuterol; Alprostadil; Animals; Bradykinin; Capillary Permeability; Cattle; Cyclic AMP; Cyclooxygenase Inhibitors; Dinoprostone; Endothelium, Vascular; Iloprost; Prostaglandins; Serum Albumin

Isolated smooth muscle cells from the circular layer of pig and guinea-pig ileum were used to study the effect of prostaglandin E2 (PGE2) and three PGE2 receptor (EP) agonists; iloprost (EP1), butaprost (EP2) and enprostil (EP3). In pig cells, PGE2 and enprostil induced cell contraction (22.1 and 21.5% shortening of cell length, obtained at 10 nM for PGE2 and 1 nM for enprostil, respectively). Iloprost and butaprost had no contractile effect. However, the cholecystokinin octapeptide (CCK-8; 10 nM)-induced contraction was inhibited when cells were preincubated with iloprost or butaprost. In guinea-pig cells, PGE2, butaprost and iloprost induced cell contraction, whereas enprostil had no effect (23.1% for 10 nM PGE2, 22.8% for 1 nM butaprost and 22.6% for 10 nM iloprost). Preincubation with SC19220 (EP1 antagonist) inhibited the PGE2-, butaprost- and iloprost-induced contractions. When the contractile effect of PGE2, butaprost and iloprost was inhibited by addition of SC19220, these agents inhibited the cell contraction induced by CCK-8 (1 nM). Smooth muscle cells from guinea-pig and pig ileum express two PGE2 receptor subtypes that induce opposite effect. EP1 and EP3 receptors mediate cell contraction in guinea-pig and pig, respectively, whereas EP2 receptors mediate cell relaxation in both species.

Topics: Alprostadil; Animals; Dibenz(b,f)(1,4)oxazepine-10(11H)-carboxylic acid, 8-chloro-, 2-acetylhydrazide; Dinoprostone; Enprostil; Guinea Pigs; Ileum; Iloprost; In Vitro Techniques; Male; Muscle Contraction; Muscle, Smooth; Prostaglandins E, Synthetic; Receptors, Prostaglandin; Sincalide; Swine