S Narumiya, N Hirata, T Namba, Y Hayashi, F Ushikubi, Y Sugimoto, M Negishi, A Ichikawa
We have recently cloned cDNAs for the human and mouse TXA2/PGH2 receptors and a cDNA for the mouse PGE receptor. Sequencing, homology and hydrophobicity analyses revealed that they are proteins of 343, 341 and 365 amino acid residues, respectively, and all are rhodopsin-type receptors with putative seven transmembrane domains. Homology between the human and mouse TXA2 receptors is 76% in total and that between the human TXA2 and mouse PGE receptors is 38%. The homology increases in the putative transmembrane regions to 85 and 45%, respectively, and there observed several features common to the three receptors. These results indicate that the prostanoid receptors constitute a family of receptors of similar structure. The cloned PGE receptor showed binding activity specific to so-called EP3 agonists, which verified for the first time that pharmacologically defined PGE receptor subtypes consist of different molecules. This receptor also displayed different efficiency in signal transduction to an EP3 agonist, M & B-28767, and PGE2, providing an interesting model for the analysis of receptor-G protein coupling. In addition to the above biochemical results, these studies have revealed the characteristic tissue distribution of these receptors, which will open up a new biology of these prostanoids.
{"title":"Structure and function of prostanoid receptors.","authors":"S Narumiya, N Hirata, T Namba, Y Hayashi, F Ushikubi, Y Sugimoto, M Negishi, A Ichikawa","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>We have recently cloned cDNAs for the human and mouse TXA2/PGH2 receptors and a cDNA for the mouse PGE receptor. Sequencing, homology and hydrophobicity analyses revealed that they are proteins of 343, 341 and 365 amino acid residues, respectively, and all are rhodopsin-type receptors with putative seven transmembrane domains. Homology between the human and mouse TXA2 receptors is 76% in total and that between the human TXA2 and mouse PGE receptors is 38%. The homology increases in the putative transmembrane regions to 85 and 45%, respectively, and there observed several features common to the three receptors. These results indicate that the prostanoid receptors constitute a family of receptors of similar structure. The cloned PGE receptor showed binding activity specific to so-called EP3 agonists, which verified for the first time that pharmacologically defined PGE receptor subtypes consist of different molecules. This receptor also displayed different efficiency in signal transduction to an EP3 agonist, M & B-28767, and PGE2, providing an interesting model for the analysis of receptor-G protein coupling. In addition to the above biochemical results, these studies have revealed the characteristic tissue distribution of these receptors, which will open up a new biology of these prostanoids.</p>","PeriodicalId":16323,"journal":{"name":"Journal of lipid mediators","volume":"6 1-3","pages":"155-61"},"PeriodicalIF":0.0,"publicationDate":"1993-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19380649","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Narumiya, N. Hirata, T. Namba, Y. Hayashi, F. Ushikubi, Y. Sugimoto, M. Negishi, A. Ichikawa
We have recently cloned cDNAs for the human and mouse TXA2/PGH2 receptors and a cDNA for the mouse PGE receptor. Sequencing, homology and hydrophobicity analyses revealed that they are proteins of 343, 341 and 365 amino acid residues, respectively, and all are rhodopsin-type receptors with putative seven transmembrane domains. Homology between the human and mouse TXA2 receptors is 76% in total and that between the human TXA2 and mouse PGE receptors is 38%. The homology increases in the putative transmembrane regions to 85 and 45%, respectively, and there observed several features common to the three receptors. These results indicate that the prostanoid receptors constitute a family of receptors of similar structure. The cloned PGE receptor showed binding activity specific to so-called EP3 agonists, which verified for the first time that pharmacologically defined PGE receptor subtypes consist of different molecules. This receptor also displayed different efficiency in signal transduction to an EP3 agonist, M & B-28767, and PGE2, providing an interesting model for the analysis of receptor-G protein coupling. In addition to the above biochemical results, these studies have revealed the characteristic tissue distribution of these receptors, which will open up a new biology of these prostanoids.
{"title":"Structure and function of prostanoid receptors.","authors":"S. Narumiya, N. Hirata, T. Namba, Y. Hayashi, F. Ushikubi, Y. Sugimoto, M. Negishi, A. Ichikawa","doi":"10.2492/JSIR1981.18.393","DOIUrl":"https://doi.org/10.2492/JSIR1981.18.393","url":null,"abstract":"We have recently cloned cDNAs for the human and mouse TXA2/PGH2 receptors and a cDNA for the mouse PGE receptor. Sequencing, homology and hydrophobicity analyses revealed that they are proteins of 343, 341 and 365 amino acid residues, respectively, and all are rhodopsin-type receptors with putative seven transmembrane domains. Homology between the human and mouse TXA2 receptors is 76% in total and that between the human TXA2 and mouse PGE receptors is 38%. The homology increases in the putative transmembrane regions to 85 and 45%, respectively, and there observed several features common to the three receptors. These results indicate that the prostanoid receptors constitute a family of receptors of similar structure. The cloned PGE receptor showed binding activity specific to so-called EP3 agonists, which verified for the first time that pharmacologically defined PGE receptor subtypes consist of different molecules. This receptor also displayed different efficiency in signal transduction to an EP3 agonist, M & B-28767, and PGE2, providing an interesting model for the analysis of receptor-G protein coupling. In addition to the above biochemical results, these studies have revealed the characteristic tissue distribution of these receptors, which will open up a new biology of these prostanoids.","PeriodicalId":16323,"journal":{"name":"Journal of lipid mediators","volume":"11 1","pages":"155-61"},"PeriodicalIF":0.0,"publicationDate":"1993-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73163839","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We have previously shown that human polymorphonuclear leukocytes (PMNL) convert 6-trans isomers of leukotriene B4 (LTB4) to 6,11-dihydro metabolites (Powell and Gravelle (1988) J. Biol. Chem. 263, 2170-2177). In the present study, we have shown that the first step in the formation of these dihydro metabolites is oxidation of the 5-hydroxyl group to a 5-oxo group, which is catalyzed by an NADP(+)-dependent microsomal dehydrogenase enzyme. All the dihydroxyeicosanoids we investigated which contained a 5(S)-hydroxyl group followed by a 6-trans double bond were good substrates for this reaction. However, LTB4, which contains a 6-cis double bond, was not metabolized to any detectable 5-oxo products. The preferred substrate for the dehydrogenase reaction is 5(S)-hydroxy-6,8,11,14-eicosatetraenoic acid (5(S)-HETE), which has a Km of about 0.2 microM, compared to approx. 0.9 microM for 12-epi-6-trans-LTB4. In contrast to 5(S)-HETE, 5(R)-HETE as well as a variety of positional isomers of 5(S)-HETE are not metabolized to significant extents by the PMNL dehydrogenase. 5-Oxo-ETE and 5-oxo-15-hydroxy-ETE, which are formed from 5(S)-HETE and 5,15-diHETE, respectively, by this pathway, are potent chemotactic agents for human neutrophils, and raise intracellular calcium levels in these cells.
我们之前已经证明,人类多态核白细胞(PMNL)将白三烯B4 (LTB4)的6-反式异构体转化为6,11-二氢代谢物(Powell and Gravelle (1988) J. Biol.)。化学。263,2170-2177)。在目前的研究中,我们已经证明形成这些二氢代谢物的第一步是5-羟基氧化为5-氧基,这是由NADP(+)依赖性微粒体脱氢酶催化的。我们所研究的所有含有5(S)-羟基和6-反式双键的二羟基二醇类化合物都是该反应的良好底物。然而,含有6-顺式双键的LTB4没有代谢成任何可检测到的5-氧产物。脱氢酶反应的首选底物是5(S)-羟基-6,8,11,14-二十碳四烯酸(5(S)-HETE),其Km约为0.2微米。0.9微米的12-epi-6-trans-LTB4。与5(S)-HETE相反,5(R)-HETE以及5(S)-HETE的各种位置异构体在很大程度上不被PMNL脱氢酶代谢。5-oxo- ete和5-oxo-15-羟基- ete分别由5(S)-HETE和5,15-二hete通过该途径形成,它们是人类中性粒细胞的有效趋化剂,可以提高这些细胞的细胞内钙水平。
{"title":"Metabolism of 5(S)-hydroxyeicosanoids by a specific dehydrogenase in human neutrophils.","authors":"W S Powell, F Gravelle, S Gravel, M Hashefi","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>We have previously shown that human polymorphonuclear leukocytes (PMNL) convert 6-trans isomers of leukotriene B4 (LTB4) to 6,11-dihydro metabolites (Powell and Gravelle (1988) J. Biol. Chem. 263, 2170-2177). In the present study, we have shown that the first step in the formation of these dihydro metabolites is oxidation of the 5-hydroxyl group to a 5-oxo group, which is catalyzed by an NADP(+)-dependent microsomal dehydrogenase enzyme. All the dihydroxyeicosanoids we investigated which contained a 5(S)-hydroxyl group followed by a 6-trans double bond were good substrates for this reaction. However, LTB4, which contains a 6-cis double bond, was not metabolized to any detectable 5-oxo products. The preferred substrate for the dehydrogenase reaction is 5(S)-hydroxy-6,8,11,14-eicosatetraenoic acid (5(S)-HETE), which has a Km of about 0.2 microM, compared to approx. 0.9 microM for 12-epi-6-trans-LTB4. In contrast to 5(S)-HETE, 5(R)-HETE as well as a variety of positional isomers of 5(S)-HETE are not metabolized to significant extents by the PMNL dehydrogenase. 5-Oxo-ETE and 5-oxo-15-hydroxy-ETE, which are formed from 5(S)-HETE and 5,15-diHETE, respectively, by this pathway, are potent chemotactic agents for human neutrophils, and raise intracellular calcium levels in these cells.</p>","PeriodicalId":16323,"journal":{"name":"Journal of lipid mediators","volume":"6 1-3","pages":"361-8"},"PeriodicalIF":0.0,"publicationDate":"1993-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19379906","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The production of platelet-activating factor (PAF), an alkyl ether phospholipid, was previously shown to occur in the brain upon various stimuli, and binding sites for PAF have been reported. We have recently demonstrated the existence of functional mRNA for PAF receptor in the brain by using a Xenopus oocyte expression system (Bito et al. (1992) Neuron 9, 285-294). In this review, we have analyzed the binding characteristics of PAF receptor in the rat brain and show that PAF receptor is ubiquitously distributed in the rat central nervous system, with an emphasis to the hypothalamus, cerebral cortex, and olfactory bulb. PAF was also found to mobilize intracellular Ca2+ in rat hippocampus.
血小板活化因子(PAF)是一种烷基醚磷脂,先前已被证明在各种刺激下发生在大脑中,并且已报道了PAF的结合位点。我们最近通过使用爪蟾卵细胞表达系统证明了PAF受体在大脑中功能性mRNA的存在(Bito et al. (1992) Neuron 9,285 -294)。本文分析了PAF受体在大鼠脑中的结合特性,发现PAF受体广泛分布于大鼠中枢神经系统,主要分布在下丘脑、大脑皮层和嗅球。PAF还能调动大鼠海马细胞内Ca2+。
{"title":"Characterization of platelet-activating factor (PAF) receptor in the rat brain.","authors":"H Bito, Y Kudo, T Shimizu","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>The production of platelet-activating factor (PAF), an alkyl ether phospholipid, was previously shown to occur in the brain upon various stimuli, and binding sites for PAF have been reported. We have recently demonstrated the existence of functional mRNA for PAF receptor in the brain by using a Xenopus oocyte expression system (Bito et al. (1992) Neuron 9, 285-294). In this review, we have analyzed the binding characteristics of PAF receptor in the rat brain and show that PAF receptor is ubiquitously distributed in the rat central nervous system, with an emphasis to the hypothalamus, cerebral cortex, and olfactory bulb. PAF was also found to mobilize intracellular Ca2+ in rat hippocampus.</p>","PeriodicalId":16323,"journal":{"name":"Journal of lipid mediators","volume":"6 1-3","pages":"169-74"},"PeriodicalIF":0.0,"publicationDate":"1993-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19380651","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
L C Hsi, A L Tsai, R J Kulmacz, D G English, A O Siefker, J C Otto, W L Smith
The active site sequence 385-YHWH-388 of ovine prostaglandin endoperoxide synthase-1 (PGHS-1) has residues critical for cyclooxygenase and peroxidase catalysis. Tyr385 is essential for cyclooxygenase activity, His386, for peroxidase activity, and His388, for both activities. To determine the importance of Trp387, we used site-directed mutagenesis to replace Trp387 of PGHS-1 with arginine, phenylalanine, and serine. W387R and W387S lacked significant activity. W387F retained both cyclooxygenase and peroxidase activities. Thus, we conclude that Trp387 is not essential for catalysis by PGHS-1. Purified PGHS-1 is a homodimer. There are two putative leucine zipper regions in ovine PGHS-1 involving residues 345-366 and 487-508. We tested for a role of these leucine zippers as determinants of dimer formation. Helix-breaking proline mutations were introduced at Leu359 or Leu501. Neither of these residues proved to be essential for peroxidase activity; but, mutations at each residue greatly reduced or eliminated cyclooxygenase activity. Both mutant proteins chromatographed as dimers on Sephacryl G-200. Thus, neither of these putative leucine zipper regions alone is responsible for PGHS-1 dimer formation.
{"title":"Trp387 and the putative leucine zippers of PGH synthases-1 and -2.","authors":"L C Hsi, A L Tsai, R J Kulmacz, D G English, A O Siefker, J C Otto, W L Smith","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>The active site sequence 385-YHWH-388 of ovine prostaglandin endoperoxide synthase-1 (PGHS-1) has residues critical for cyclooxygenase and peroxidase catalysis. Tyr385 is essential for cyclooxygenase activity, His386, for peroxidase activity, and His388, for both activities. To determine the importance of Trp387, we used site-directed mutagenesis to replace Trp387 of PGHS-1 with arginine, phenylalanine, and serine. W387R and W387S lacked significant activity. W387F retained both cyclooxygenase and peroxidase activities. Thus, we conclude that Trp387 is not essential for catalysis by PGHS-1. Purified PGHS-1 is a homodimer. There are two putative leucine zipper regions in ovine PGHS-1 involving residues 345-366 and 487-508. We tested for a role of these leucine zippers as determinants of dimer formation. Helix-breaking proline mutations were introduced at Leu359 or Leu501. Neither of these residues proved to be essential for peroxidase activity; but, mutations at each residue greatly reduced or eliminated cyclooxygenase activity. Both mutant proteins chromatographed as dimers on Sephacryl G-200. Thus, neither of these putative leucine zipper regions alone is responsible for PGHS-1 dimer formation.</p>","PeriodicalId":16323,"journal":{"name":"Journal of lipid mediators","volume":"6 1-3","pages":"131-8"},"PeriodicalIF":0.0,"publicationDate":"1993-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19343769","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Inflammation, prostaglandins, and loss of function.","authors":"D A Willoughby, P R Colville-Nash, M P Seed","doi":"","DOIUrl":"","url":null,"abstract":"","PeriodicalId":16323,"journal":{"name":"Journal of lipid mediators","volume":"6 1-3","pages":"287-93"},"PeriodicalIF":0.0,"publicationDate":"1993-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19344401","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Control mechanisms for the ductus arteriosus and the perinatal pulmonary circulation.","authors":"F Coceani","doi":"","DOIUrl":"","url":null,"abstract":"","PeriodicalId":16323,"journal":{"name":"Journal of lipid mediators","volume":"6 1-3","pages":"473-6"},"PeriodicalIF":0.0,"publicationDate":"1993-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19344983","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
D L Simmons, W Xie, G Evett, J Merrill, D L Robertson, W S Bradshaw
Prostaglandin G/H synthase isoenzyme 2 (PGHS-2) was identified as an immediate-early gene product induced by Rous sarcoma virus, serum, phorbol ester and a wide variety of other mitogens. Induction of PGHS-2 occurs through an increase in PGHS-2 gene transcription. Dexamethasone inhibits both the basal and induced levels of PGHS-2 mRNA. In contrast, PGHS-1 gene transcription rate, mRNA, and protein levels are unaffected by mitogens and dexamethasone. Post-transcriptional down-regulation of PGHS-2 mRNA plays a significant role in causing dexamethasone's effect. Specific cell systems have been identified which allow selective analysis of PGHS-1 and PGHS-2 at the nucleic acid and protein levels. These cell systems indicate that PGHS-1 and PGHS-2 may have different sensitivities to non-steroidal anti-inflammatory drugs. Furthermore, inhibition of PGHS activity correlates well with suppression of the transformed phenotype in an in vitro cell model.
{"title":"Drug inhibition and cellular regulation of prostaglandin G/H synthase isoenzyme 2.","authors":"D L Simmons, W Xie, G Evett, J Merrill, D L Robertson, W S Bradshaw","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Prostaglandin G/H synthase isoenzyme 2 (PGHS-2) was identified as an immediate-early gene product induced by Rous sarcoma virus, serum, phorbol ester and a wide variety of other mitogens. Induction of PGHS-2 occurs through an increase in PGHS-2 gene transcription. Dexamethasone inhibits both the basal and induced levels of PGHS-2 mRNA. In contrast, PGHS-1 gene transcription rate, mRNA, and protein levels are unaffected by mitogens and dexamethasone. Post-transcriptional down-regulation of PGHS-2 mRNA plays a significant role in causing dexamethasone's effect. Specific cell systems have been identified which allow selective analysis of PGHS-1 and PGHS-2 at the nucleic acid and protein levels. These cell systems indicate that PGHS-1 and PGHS-2 may have different sensitivities to non-steroidal anti-inflammatory drugs. Furthermore, inhibition of PGHS activity correlates well with suppression of the transformed phenotype in an in vitro cell model.</p>","PeriodicalId":16323,"journal":{"name":"Journal of lipid mediators","volume":"6 1-3","pages":"113-7"},"PeriodicalIF":0.0,"publicationDate":"1993-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19343768","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
(1) Human cartilage, both non-arthritic (N) and arthritic, is extremely sensitive to inhibition of glycosaminoglycan (GAG) synthesis by low concentrations of interleukin 1 (IL1). Local episodic synthesis and secretion of sub-nanogram concentrates of the cytokine is considered to play a significant role in the pathogenesis of osteoarthritis (OA) by preventing matrix repair. (2) The synthesis of IL1 can be controlled by prostaglandins (PGs), which may explain why the inhibitory action can be at least partially overcome by the action of the PG analogue Misoprostol in the dose range 10-100 ng/ml. It is suggested that this action is due to the suppression of a positive feedback loop for local IL1 synthesis and secretion. (3) Certain non-steroidal anti-inflammatory drugs (NSAIDs), in particular Indomethacin, Ibuprofen and Naproxen, cause inhibition of GAG synthesis, and hence may diminish the potentiality for repair in arthritic cartilage. It is suggested that these NSAIDs induce IL1 synthesis by diminishing PG levels. Misoprostol is able to reverse this effect at least partially. (4) Some cartilages in the presence of other NSAIDs, such as Diclofenac, which do not greatly inhibit chondrocyte matrix metabolism, nevertheless respond to the presence of Misoprostol by increased GAG synthetic activity. (5) The low mean matrix synthetic activity of human OA cartilages was significantly increased by Misoprostol. (6) Taken together, these studies substantiate the suggestion that Misoprostol is able to increase the repair potentiality of human OA cartilage, particularly during treatment with NSAIDs.
(1)人类软骨,无论是非关节炎软骨(N)还是关节炎软骨,都对低浓度的白细胞介素1 (IL1)抑制糖胺聚糖(GAG)合成极为敏感。局部偶发性合成和分泌亚纳克浓度的细胞因子被认为通过阻止基质修复在骨关节炎(OA)的发病机制中发挥重要作用。(2) il -1的合成可以由前列腺素(PG)控制,这可能解释了为什么PG类似物米索前列醇在10-100 ng/ml剂量范围内的作用至少可以部分克服抑制作用。这表明这种作用是由于抑制了局部il - 1合成和分泌的正反馈回路。(3)某些非甾体抗炎药(NSAIDs),特别是吲哚美辛、布洛芬和萘普生,会抑制GAG合成,因此可能会降低关节炎软骨修复的潜力。这些非甾体抗炎药通过降低PG水平诱导il - 1合成。米索前列醇能够至少部分地逆转这种影响。(4)一些软骨在存在其他非甾体抗炎药(如双氯芬酸)的情况下,对软骨细胞基质代谢没有很大的抑制作用,但对米索前列醇的存在有反应,通过增加GAG合成活性。(5)米索前列醇可显著提高人OA软骨的低平均基质合成活性。(6)综上所述,这些研究证实了米索前列醇能够增加人OA软骨的修复潜力,特别是在非甾体抗炎药治疗期间。
{"title":"Prostaglandins in human cartilage metabolism.","authors":"J T Dingle","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>(1) Human cartilage, both non-arthritic (N) and arthritic, is extremely sensitive to inhibition of glycosaminoglycan (GAG) synthesis by low concentrations of interleukin 1 (IL1). Local episodic synthesis and secretion of sub-nanogram concentrates of the cytokine is considered to play a significant role in the pathogenesis of osteoarthritis (OA) by preventing matrix repair. (2) The synthesis of IL1 can be controlled by prostaglandins (PGs), which may explain why the inhibitory action can be at least partially overcome by the action of the PG analogue Misoprostol in the dose range 10-100 ng/ml. It is suggested that this action is due to the suppression of a positive feedback loop for local IL1 synthesis and secretion. (3) Certain non-steroidal anti-inflammatory drugs (NSAIDs), in particular Indomethacin, Ibuprofen and Naproxen, cause inhibition of GAG synthesis, and hence may diminish the potentiality for repair in arthritic cartilage. It is suggested that these NSAIDs induce IL1 synthesis by diminishing PG levels. Misoprostol is able to reverse this effect at least partially. (4) Some cartilages in the presence of other NSAIDs, such as Diclofenac, which do not greatly inhibit chondrocyte matrix metabolism, nevertheless respond to the presence of Misoprostol by increased GAG synthetic activity. (5) The low mean matrix synthetic activity of human OA cartilages was significantly increased by Misoprostol. (6) Taken together, these studies substantiate the suggestion that Misoprostol is able to increase the repair potentiality of human OA cartilage, particularly during treatment with NSAIDs.</p>","PeriodicalId":16323,"journal":{"name":"Journal of lipid mediators","volume":"6 1-3","pages":"303-12"},"PeriodicalIF":0.0,"publicationDate":"1993-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19344403","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Biosynthesis of thromboxane A2 (TxA2) during cell-cell interactions between platelets and alveolar macrophages, eosinophils and natural killer cells from guinea pigs has been investigated. The stimulation of platelets incubated with varying numbers of macrophages or eosinophils or NK cells with 5 microM ionophore A23187 has induced an increase of TxA2 synthesis in comparison to the sum of TxA2 production by each cell population stimulated alone. These results suggest that transcellular biosynthesis of TxA2 or cell cooperation occurred between platelets and the other cell population studied, which could correspond to cell-cell interactions of type IA and/or type III, according to the classification proposed by Marcus ((1986) Prog. Hemost. Thromb. 28, 127-42). When varying concentrations of platelets were incubated with the supernatant of cells previously stimulated with the ionophore A23187, an enhancement of TxA2 release was also observed. However, the supernatant of platelets stimulated with the ionophore A23187 did not induce a significant increase of TxA2 synthesis by the other cell populations. It is suggested that the biosynthesis of TxA2 during cell-cell interactions could account for the large amount recovered in biological fluid in various pathological conditions such as inflammatory and hypersensitivity reactions.
{"title":"Cell-cell interactions between platelets, macrophages, eosinophils and natural killer cells in thromboxane A2 biosynthesis.","authors":"K Maghni, J Carrier, S Cloutier, P Sirois","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Biosynthesis of thromboxane A2 (TxA2) during cell-cell interactions between platelets and alveolar macrophages, eosinophils and natural killer cells from guinea pigs has been investigated. The stimulation of platelets incubated with varying numbers of macrophages or eosinophils or NK cells with 5 microM ionophore A23187 has induced an increase of TxA2 synthesis in comparison to the sum of TxA2 production by each cell population stimulated alone. These results suggest that transcellular biosynthesis of TxA2 or cell cooperation occurred between platelets and the other cell population studied, which could correspond to cell-cell interactions of type IA and/or type III, according to the classification proposed by Marcus ((1986) Prog. Hemost. Thromb. 28, 127-42). When varying concentrations of platelets were incubated with the supernatant of cells previously stimulated with the ionophore A23187, an enhancement of TxA2 release was also observed. However, the supernatant of platelets stimulated with the ionophore A23187 did not induce a significant increase of TxA2 synthesis by the other cell populations. It is suggested that the biosynthesis of TxA2 during cell-cell interactions could account for the large amount recovered in biological fluid in various pathological conditions such as inflammatory and hypersensitivity reactions.</p>","PeriodicalId":16323,"journal":{"name":"Journal of lipid mediators","volume":"6 1-3","pages":"321-32"},"PeriodicalIF":0.0,"publicationDate":"1993-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19344406","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}