11-deoxyprostaglandin-e1 and butaprost

Prostaglandin E2 (PGE2) exerts its biological actions via EP receptors, which are divided into four subtypes of EP1, EP2, EP3 and EP4. In the present study, we investigated whether PGE2 regulated interleukin (IL)-6 production in human gingival fibroblasts (HGF) stimulated with IL-1beta and if so, which subtype(s) of PGE2 receptors were involved. Indomethacin, a cyclooxygenase inhibitor, significantly enhanced IL-1beta-induced IL-6 production by HGF, although it completely inhibited IL-1beta-induced PGE2 production. Exogenous PGE2 suppressed the IL-1beta-induced IL-6 production. Reverse transcription-polymerase chain reaction analysis demonstrated that mRNA of EP1, EP2 and EP4, but not EP3 mRNA, was expressed in unstimulated and IL-1beta-stimulated HGF. 11-deoxy-PGE1, a selective EP2/EP3/EP4 agonist, and butaprost, a selective EP2 agonist, inhibited IL-1beta-induced IL-6 production, although butaprost was less potent than 11-deoxy-PGE1. 17-phenyl-omega-trinor PGE2, an EP1 agonist, enhanced IL-1beta-induced IL-6 production. Based on these data, we suggest that PGE2 can up- or downregulate IL-1beta-induced IL-6 production via EP1 receptors or via EP2/EP4 receptors in HGF, respectively. Expression and function of EP1, EP2 and EP4 receptors in HGF may play critical roles in controlling inflammatory periodontal conditions.

Topics: Alprostadil; Analysis of Variance; Cells, Cultured; Cyclooxygenase Inhibitors; Dinoprostone; Down-Regulation; Fibroblasts; Gingiva; Humans; Indomethacin; Interleukin-1; Interleukin-6; Prostaglandins E, Synthetic; Receptors, Prostaglandin E; Receptors, Prostaglandin E, EP1 Subtype; Receptors, Prostaglandin E, EP2 Subtype; Receptors, Prostaglandin E, EP3 Subtype; Receptors, Prostaglandin E, EP4 Subtype; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Statistics as Topic; Up-Regulation

The purpose of these studies was to investigate the pharmacology of E-series and selected prostaglandins of other classes on adenylyl cyclase activity in Chinese hamster ovary (CHO) cells expressing an endogenous prostanoid receptor and to compare these responses with those from immortalized human non-pigmented ciliary epithelial (NPE) cells containing the EP2 receptor. 11-deoxy-PGE2 was the most potent of the 16 prostanoid agonists tested for stimulating cAMP formation with a potency (EC50) value of 26 +/- 6 nM in the CHO cells. The endogenous ligand, PGE2, exhibited potencies of 40 +/- 7 nM (n = 24) in the CHO cells and 67 +/- 9 nM (n = 46) in the NPE cells. The EP2 receptor agonist, butaprost, produced an EC50 value of 212 +/- 58 nM (n = 4) in the NPE cells while being inactive (EC50 > 10,000 nM, n = 6) in the CHO cells. The EP4 receptor selective antagonists, AH22921 and AH23848B, at a concentration of 30 microM, caused a 2.2 +/- 0.5 (n = 4) and 8.2 +/- 2.7 (n = 4) fold rightward shift in the PGE2 concentration-response curves in the CHO cells, yielding apparent pKb values of 4.6 +/- 0.6 and 5.3 +/- 0.2 (n = 4), respectively. AH22921 and AH23848B were non-competitive antagonists at the CHO cell EP4 receptor, but did not shift the PGE2 concentration-response curves in the NPE cells containing the EP2 receptor. These studies have characterized the functional prostaglandin receptors in CHO cells pharmacologically and shown them to be consistent with the EP4 subtype.

Topics: Adenylyl Cyclases; Alprostadil; Animals; Biphenyl Compounds; Cell Line, Transformed; CHO Cells; Cricetinae; Cyclic AMP; Dinoprostone; Humans; Misoprostol; Prostaglandins E, Synthetic; Receptors, Prostaglandin E; Receptors, Prostaglandin E, EP4 Subtype

High glucose reportedly stimulates prostaglandin (PG) E2 production and DNA synthesis in mesangial cells (MCs). However, the pathophysiological significance of PGE2 in MCs has remained unclear.. The effects of prostanoids on [3H]-thymidine uptake and cAMP production in rat MCs cultured with 5.6 mM glucose, 25 mM glucose, or 5.6 mM glucose supplemented with 19.4 mM mannitol were examined. The gene expression of PGE2 receptor (EP) subtypes in MCs was analyzed with Northern blotting techniques.. Northern blotting indicated EP1 and EP4 gene expression in MCs. EP1 agonists and PGE2 stimulated [3H]-thymidine uptake in MCs. EP1 antagonists dose dependently attenuated high-glucose-induced [3H]-thymidine uptake, which suggests EP1 involvement, by an increase in intracellular Ca2+, in DNA synthesis of MCs. On the other hand, forskolin, db-cAMP, and 11-deoxy-PGE1, an EP4/EP3/EP2 agonist, significantly decreased DNA synthesis in MCs. These inhibitory effects are thought to be mediated via EP4 as a result of an increase in cAMP synthesis. The effects via EP4 seem to be particularly important because PGE2-induced cAMP synthesis was significantly attenuated in the high-glucose group compared with the mannitol group, in which [3H]-thymidine uptake did not increase in spite of augmented PGE2 production.. The increase in DNA synthesis in MCs under high-glucose conditions can be explained, at least in part, by the high-glucose-induced inhibition of cAMP production via EP4, which augments EP1 function in conjunction with the overproduction of PGE2.

Topics: 1-Methyl-3-isobutylxanthine; Alprostadil; Animals; Anti-Ulcer Agents; Blotting, Northern; Calcium; Cells, Cultured; Colforsin; Cyclic AMP; Dinoprostone; Gene Expression; Glomerular Mesangium; Glucose; Male; Menstruation-Inducing Agents; Phosphodiesterase Inhibitors; Prostaglandins E, Synthetic; Rats; Rats, Inbred WKY; Receptors, Prostaglandin E; Receptors, Prostaglandin E, EP1 Subtype; RNA, Messenger; Thymidine; Tritium

Of various PGs, PGE1 and PGE2 are shown to be the most potent stimulators of osteoclastogenesis in vitro. PGE receptors have been classified into four subtypes, EP1-EP4. Little is known about PGE receptors functioning in bone cells. In this study, using mouse marrow culture, we investigated which PGE receptors are important in osteoclast-like cell (OCL) formation induced by PGE. 11-deoxy-PGE1 (EP2, EP3 and EP4 agonist) stimulated OCL formation potently. Butaprost (EP2 agonist) stimulated it slightly, while sulprostone (EP1 and EP3 agonist) and ONO-AP-324-01 (EP3 agonist) did not. AH23848B (EP4 antagonist) inhibited PGE2-induced OCL formation in a dose-dependent manner. The expression of EP4 mRNA in mouse bone marrow was confirmed by RT-PCR. The results indicate an important role of EP4 in PGE2-induced OCL formation in marrow cultures and suggest therapeutic potential of EP4 antagonists in some clinical conditions with accelerated bone resorption.

Topics: Alprostadil; Animals; Anti-Arrhythmia Agents; Anti-Ulcer Agents; Biphenyl Compounds; Bone Marrow Cells; Cell Differentiation; Cells, Cultured; Depression, Chemical; Dinoprostone; Dose-Response Relationship, Drug; Male; Mice; Osteoclasts; Polymerase Chain Reaction; Prostaglandins E, Synthetic; Receptors, Prostaglandin E; Receptors, Prostaglandin E, EP4 Subtype; RNA, Messenger

1. Prostanoids induce a wide range of biological actions which are mediated by specific membrane-bound receptors. We have recently shown that the E-type prostaglandins, PGE1 and PGE2, effectively inhibit eosinophil aggregation induced by platelet-activating factor (PAF). In an attempt to determine which prostanoid receptor(s) were involved, we investigated the effects of a range of selective prostanoid agonists and antagonists on eosinophil homotypic aggregation induced by PAF. 2. Both PGE1 and PGE2 (10(-10) to 10(-6) M) induced a concentration-related inhibition of the aggregation response induced by PAF. PGE1 was more effective than PGE2 but PGE2 was slightly more potent than PGE1 (approximate IC50 values for PGE1 and PGE2 of 1.5 x 10(-8) M and 5 x 10(-9) M, respectively). 3. The EP2-selective agonists, 11-deoxy-PGE1, butaprost and AH13205, and the EP2/EP3-selective agonist, misoprostol, also inhibited PAF-induced aggregation. The rank order of potency for EP2-selective agonists was 11-deoxy-PGE1 > misoprostol > butaprost = AH13205. The protein kinase A inhibitor, KT5720 (10(-6) M), reversed the inhibitory effects of 11-deoxy-PGE1 (10(-6) M) and AH13205 (10(-5) M). 4. The EP1/EP3-selective agonist, sulprostone, and the EP1-selective agonist, 17-phenyl-omega-trinor PGE2, had no significant inhibitory activity when tested at concentrations up to 10(-6) M. The EP4-receptor antagonist, AH23848B, had no effect on PAF-induced aggregation and did affect the inhibitory activity of PGE1. 5. The IP-selective agonist, cicaprost (up to 10(-6) M), and the IP/EP1-receptor agonist, iloprost (up to 10(-5) M), had no significant effect on PAF-induced eosinophil aggregation. However, iloprost significantly augmented the inhibitory effects of a maximally inhibitory concentration of PGE2. 6. PGD2 (10(-5) M) had no effect on eosinophil aggregation and the inhibitory activity of PGE1 on PAF-induced eosinophil aggregation was not altered by the DP-selective receptor antagonist, BWA868C. 7. The results presented here suggest that the inhibition of PAF-induced eosinophil aggregation by prostanoids is mediated by the occupation of EP2-receptors. It is important to note that the effects of naturally occurring prostanoids, such as PGE2, on eosinophil aggregation occur at low concentrations highlighting a potential role for EP2 receptors in regulating eosinophil function in vivo.

Topics: Alprostadil; Analysis of Variance; Animals; Anti-Ulcer Agents; Carbazoles; Cell Aggregation; Dinoprostone; Dose-Response Relationship, Drug; Eosinophils; Female; Guinea Pigs; Indoles; Misoprostol; Oxytocics; Platelet Activating Factor; Platelet Aggregation Inhibitors; Prostaglandin D2; Prostaglandins E, Synthetic; Prostanoic Acids; Protein Kinase C; Pyrroles; Receptors, Prostaglandin; Structure-Activity Relationship

PGE2 is one of the key molecules in the osteoblast. It is the major prostanoid in the bone, and its production is under the control of both systemic and local factors. PGE2 has been reported to have multiple actions in the osteoblast, such as growth promotion and cell differentiation. To better understand the action of PGE2 in the osteoblast, we determined the PGE receptor subtypes in MC3T3-E1, an osteoblastic cell line derived from the normal mouse calvaria. Northern blot analysis revealed that EP1 and EP4 subtypes are expressed in MC3T3-E1. In contrast, EP3 subtype was not detected by either Northern blot analysis or RT-PCR. The contribution of each subtype was evaluated by studying the effects of subtype-specific analogs on osteoblastic function at confluency and 5 days after confluency. An EP1 agonist, 17-phenyl-omega-trinor PGE2, increased DNA synthesis and decreased alkaline phosphatase activity. 11-Deoxy-PGE1, and EP2 and EP4 agonist, decreased DNA synthesis and increased alkaline phosphatase activity at both stages. Butaprost, an EP2-selective agonist, showed effects similar to those of 11-deoxy-PGE1 only at confluency. Another and more differentiated osteoblastic marker, osteocalcin production, was detectable and was stimulated by 11-deoxy-PGE1 only 5 days after confluency. The exposure of these cells to EP1 agonist changed the cell shape to a more fibroblastic appearance. These results indicate that EP1, EP4, and probably EP2 are present in MC3T3-E1 cells; EP1 promotes cell growth, and EP2 and EP4 mediate differentiation of the osteoblast. Furthermore, the decreased response to EP2-specific agonist 5 days after confluency suggests that the expression of PGE receptor subtype is dependent on the stage of osteoblastic differentiation. This is the first report to determine PGE receptor subtypes in the bone.

Topics: Alprostadil; Animals; Base Sequence; Blotting, Southern; Bucladesine; Cell Line; Dinoprostone; DNA; Mice; Molecular Sequence Data; Osteoblasts; Polymerase Chain Reaction; Prostaglandins E, Synthetic; Receptors, Prostaglandin E; RNA, Messenger

A fourth PGE receptor subtype, the EP4 receptor, has recently been described in the pig saphenous vein (PSV). Similar to the EP2 receptor, it mediates relaxation and is linked to stimulation of adenylate cyclase. The aim of this study was to determine whether or not the EP receptor present in the rabbit jugular vein (RJV), currently classified as an atypical EP2 receptor, is of the EP4 subtype. The relaxant activities of four EP2 agonists, 11-deoxy PGE1, 16,16-dimethyl PGE2, butaprost, and AH 13205, on the RJV and PSV have been examined, and the effect of the EP4 receptor antagonist AH 23,848B studied. The EP2 agonists showed a similar order of potency on the two preparations. 11-Deoxy PGE1 and 16,16-dimethyl PGE2 were potent agonists on the EP4 receptors of the PSV and on the RJV giving approximately equi-effective concentration ratios (EECs) of 2.0-6.6 and 2.8-9.9, respectively, compared to PGE2 (EEC = 1), and so do not discriminate between EP2 and EP4 receptors. Butaprost was less active on these preparations (EEC 42-43) than on classical EP2 receptors, and AH 13205 was much less active (EEC 3100-2780). While these results suggest that the EP receptors on the RJV are of the EP4 subtype, this was not confirmed using the EP4 receptors antagonist AH 23,848B.

Topics: 16,16-Dimethylprostaglandin E2; Alprostadil; Animals; Biphenyl Compounds; Endothelium, Vascular; Jugular Veins; Male; Muscle Relaxation; Muscle, Smooth, Vascular; Prostaglandins F, Synthetic; Prostanoic Acids; Rabbits; Receptors, Prostaglandin E; Saphenous Vein; Swine

Topics: Alprostadil; Animals; Bradykinin; Capillary Permeability; Dinoprostone; Drug Synergism; Inflammation; Rabbits; Receptors, Prostaglandin; Receptors, Prostaglandin E; Skin; Vasodilation