Biochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism最新文献

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Hypocholesterolemic properties of nitric oxide. In vivo and in vitro studies using nitric oxide donors 一氧化氮的降胆固醇特性。使用一氧化氮供体的体内和体外研究
Biochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism Pub Date : 1998-05-20 DOI: 10.1016/S0005-2760(97)00215-4
E.M Kurowska, K.K Carroll
{"title":"Hypocholesterolemic properties of nitric oxide. In vivo and in vitro studies using nitric oxide donors","authors":"E.M Kurowska,&nbsp;K.K Carroll","doi":"10.1016/S0005-2760(97)00215-4","DOIUrl":"10.1016/S0005-2760(97)00215-4","url":null,"abstract":"<div><p>Previous results suggested that changes in the activity of nitric oxide (NO) can influence metabolism of apo B-containing lipoproteins. Therefore, we studied effects of exogenous NO donors and physiological NO precursors on metabolism of these lipoproteins. In rabbits, addition of 0.03% sodium nitroprusside (NaNP) to a semipurified, cholesterol-free, casein diet counteracted the elevation of LDL cholesterol induced by this diet but did not alter liver lipids after 4 weeks of feeding. In HepG2 cells, addition of nontoxic concentrations of another NO donor, <em>S</em>-nitroso-<em>N</em>-acetylpenicillamine (SNAP) to culture medium caused a dose-dependent reduction of medium apo B after 24 h. At the concentration 0.5 mM, SNAP significantly decreased medium apo B by 50% without altering total synthesis and secretion of proteins and without altering rates of cellular sterol synthesis. In cells incubated with <span>l</span>-arginine, reduction of medium apo B was not associated with increased NO production whereas in those exposed to N–OH–Arg medium apo B levels were not altered. We concluded that synthetic NO donors can reduce hypercholesterolemia by affecting apo B metabolism directly in the liver, via the sterol-independent mechanism.</p></div>","PeriodicalId":100162,"journal":{"name":"Biochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1998-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0005-2760(97)00215-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20513872","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}
引用次数: 27
A comparative study of the metabolism of n-9, n-6 and n-3 fatty acids in testicular cells from immature rat 未成熟大鼠睾丸细胞n-9、n-6和n-3脂肪酸代谢的比较研究
Biochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism Pub Date : 1998-05-20 DOI: 10.1016/S0005-2760(98)00021-6
Kjetil Retterstøl , Trine B. Haugen , Berit Woldseth , Bjørn O. Christophersen
{"title":"A comparative study of the metabolism of n-9, n-6 and n-3 fatty acids in testicular cells from immature rat","authors":"Kjetil Retterstøl ,&nbsp;Trine B. Haugen ,&nbsp;Berit Woldseth ,&nbsp;Bjørn O. Christophersen","doi":"10.1016/S0005-2760(98)00021-6","DOIUrl":"10.1016/S0005-2760(98)00021-6","url":null,"abstract":"<div><p>Dietary 18 and 20-carbon fatty acids of the <em>n</em>-6 and the <em>n</em>-3 families are metabolized to 22:5,<em>n</em>-6 and 22:6,<em>n</em>-3 by a sequence of specific desaturases and chain elongation via 24-carbon intermediates. This pathway is regulated so that more 22:6,<em>n</em>-3 than 22:5,<em>n</em>-6 is found in the tissues. Rat testis is an exception since 22:5,<em>n</em>-6 is present in large proportions in this organ. Therefore rat testis appears to be interesting for studies of the detailed synthesis of 22:5,<em>n</em>-6 compared with that of 22:6,<em>n</em>-3. By using fresh preparations of rat testicular cells from 19-day-old rats enriched in Sertoli cells, we compared the metabolism of 1-<sup>14</sup>C-labelled <em>n</em>-3, <em>n</em>-6 and <em>n</em>-9 fatty acids. The testicular cells actively synthesized 22:6,<em>n</em>-3 and 22:5,<em>n</em>-6, but not 22:4,<em>n</em>-9 from the 18 and 20-carbon precursors. Of 200 mol <sup>14</sup>C-labelled C<sub>18</sub> and C<sub>20</sub> fatty acids added initially, approximately 20-40 mol were found as 24-carbon intermediates after 24 h of incubation. This indicates that the balanced capacity of elongation, desaturation and chain shortening favours the accumulation of 24-carbon intermediates in these cells. One exception was [1-<sup>14</sup>C]20:3,<em>n</em>-9 which was efficiently elongated to 22:3,<em>n</em>-9 but not to C<sub>24</sub> fatty acids. Our data suggests that the poor elongation of <em>n</em>-9 fatty acids from C<sub>22<sup>−</sup></sub> to C<sub>24</sub> may be an important hindrance in the synthesis of 22:4,<em>n</em>-9. The efficient synthesis of 22:5,<em>n</em>-6 may also partly explain why this is the major 22-carbon fatty acid in rat testis.</p></div>","PeriodicalId":100162,"journal":{"name":"Biochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1998-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0005-2760(98)00021-6","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20513806","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}
引用次数: 27
Role of protein kinase C α in endothelin-1 stimulation of cytosolic phospholipase A2 and arachidonic acid release in cultured cat iris sphincter smooth muscle cells 蛋白激酶C α在内皮素-1刺激培养猫虹膜括约肌平滑肌细胞胞质磷脂酶A2和花生四烯酸释放中的作用
Biochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism Pub Date : 1998-05-20 DOI: 10.1016/S0005-2760(98)00011-3
Shahid Husain, Ata A Abdel-Latif
{"title":"Role of protein kinase C α in endothelin-1 stimulation of cytosolic phospholipase A2 and arachidonic acid release in cultured cat iris sphincter smooth muscle cells","authors":"Shahid Husain,&nbsp;Ata A Abdel-Latif","doi":"10.1016/S0005-2760(98)00011-3","DOIUrl":"10.1016/S0005-2760(98)00011-3","url":null,"abstract":"<div><p>We have investigated the role and mechanism of protein kinase C (PKC) isoforms in endothelin-1 (ET-1)-induced arachidonic acid (AA) release in cat iris sphincter smooth muscle (CISM) cells. ET-1 increased AA release in a concentration (EC<sub>50</sub>=8 nM) and time-dependent (<em>t</em><sub>1/2</sub>=1.2 min) manner. Cytosolic phospholipase A<sub>2</sub> (cPLA<sub>2</sub>), but not phospholipase C (PLC), is involved in the liberation of AA in the stimulated cells. This conclusion is supported by the findings that ET-1-induced AA release is inhibited by AACOCF<sub>3</sub>, quinacrine and manoalide, PLA<sub>2</sub> inhibitors, but not by U-73122, a PLC inhibitor, or by RHC-80267, a diacylglycerol lipase inhibitor. A role for PKC in ET-1-induced AA release is supported by the findings that the phorbol ester, PDBu, increased AA release by 96%, that prolonged treatment of the cells with PDBu resulted in the selective down regulation of PKC<em>α</em> and the complete inhibition of ET-1-induced AA release, and that pretreatment of the cells with staurosporine or RO 31-8220, PKC inhibitors, blocked the ET-1-induced AA release. Gö-6976, a compound that inhibits PKC<em>α</em> and <em>β</em> specifically, blocked ET-1-induced AA release in a concentration-dependent manner with an IC<sub>50</sub> value of 8 nM. Thymeatoxin (0.1 <em>μ</em>M), a specific activator of PKC<em>α</em>, <em>β</em>, and <em>γ</em> induced a 150% increase in AA release. Treatment of the cells with ET-1 caused significant translocation of PKC<em>α</em>, but not PKC<em>β</em>, from cytosol to the particulate fraction. These results suggest that PKC<em>α</em> plays a critical role in ET-1-induced AA release in these cells. Immunochemical analysis revealed the presence of cPLA<sub>2</sub>, p42<sup>mapk</sup> and p44<sup>mapk</sup> in the CISM cells. The data presented are consistent with a role for PKC<em>α</em>, but not for p42/p44 mitogen-activated protein kinase (MAPK), in cPLA<sub>2</sub> activation and AA release in ET-1-stimulated CISM cells since: (i) the PKC inhibitor, RO 31-8220, inhibited ET-1-induced AA release, cPLA<sub>2</sub> phosphorylation and cPLA<sub>2</sub> activity, but had no inhibitory effect on p42/p44 MAPK activation, (ii) genistein, a tyrosine kinase inhibitor, inhibited ET-1-stimulated MAPK activity but had no inhibitory effect on AA release in the ET-1-stimulated cells. We conclude that in CISM cells, ET-1 activates PKC<em>α</em>, which activates cPLA<sub>2</sub>, which liberates AA for prostaglandin synthesis.</p></div>","PeriodicalId":100162,"journal":{"name":"Biochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1998-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0005-2760(98)00011-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20514121","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}
引用次数: 52
The role of platelet activating factor and other lipid mediators in inflammatory angiogenesis 血小板活化因子及其他脂质介质在炎性血管生成中的作用
Biochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism Pub Date : 1998-05-20 DOI: 10.1016/S0005-2760(98)00012-5
Jeffrey R Jackson , Brian Bolognese , Clare A Mangar , Walter C Hubbard , Lisa A Marshall , James D Winkler
{"title":"The role of platelet activating factor and other lipid mediators in inflammatory angiogenesis","authors":"Jeffrey R Jackson ,&nbsp;Brian Bolognese ,&nbsp;Clare A Mangar ,&nbsp;Walter C Hubbard ,&nbsp;Lisa A Marshall ,&nbsp;James D Winkler","doi":"10.1016/S0005-2760(98)00012-5","DOIUrl":"10.1016/S0005-2760(98)00012-5","url":null,"abstract":"<div><p>Chronic inflammatory diseases are often accompanied by intense angiogenesis. A model of inflammatory angiogenesis is the murine air pouch granuloma which has a hyperangiogenic component. Proinflammatory lipid mediator generation is also a hallmark of chronic inflammation and the role of endogenous production of these mediators in angiogenesis is not known. The 14 kDa phospholipase A<sub>2</sub> (PLA<sub>2</sub>) deacylates phospholipid, liberating arachidonic acid, which is used for leukotriene production, and lysophospholipid, which can drive the production of platelet-activating factor (PAF). Therefore, SB 203347, an inhibitor of the 14 kDa PLA<sub>2</sub>, zileuton, an inhibitor of 5-lipoxygenase, and Ro 24-4736 a PAF receptor antagonist were evaluated for their effects in the murine air pouch granuloma. SB 203347 reduced both LTB<sub>4</sub> and PAF, but not PGD<sub>2</sub> levels measured in the day 6 granuloma. This correlated with a significant reduction in angiogenesis. Zileuton reduced LTB<sub>4</sub> levels as expected, but did not significantly inhibit angiogenesis, whereas Ro 24-4736 potently reduced angiogenesis. These data support the hypothesis that PAF, and to a lesser extent leukotrienes contribute to the angiogenic phenotype in chronic inflammation.</p></div>","PeriodicalId":100162,"journal":{"name":"Biochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1998-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0005-2760(98)00012-5","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20514045","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 37
Continuous spectrophotometric assay of mammalian phosphoinositide-specific phospholipase Cδ1 with a thiophosphate substrate analog 用硫代磷酸盐底物类似物连续分光光度法测定哺乳动物磷酸肌醇特异性磷脂酶Cδ1
Biochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism Pub Date : 1998-05-20 DOI: 10.1016/S0005-2760(98)00025-3
H.Stewart Hendrickson
{"title":"Continuous spectrophotometric assay of mammalian phosphoinositide-specific phospholipase Cδ1 with a thiophosphate substrate analog","authors":"H.Stewart Hendrickson","doi":"10.1016/S0005-2760(98)00025-3","DOIUrl":"https://doi.org/10.1016/S0005-2760(98)00025-3","url":null,"abstract":"<div><p>1,2-Dimyristoyloxypropane-3-thiophospho(1<span>d</span>-1-<em>myo</em>-inositol) (<span>d</span>-thio-DMPI) was used as a substrate for the continuous assay of phosphoinositide-specific phospholipase C (PI-PLC). Its activity with a <em>Δ</em>(1–132) deletion mutant of mammalian PI-PLC<em>δ</em><sub>1</sub> is about one-fourth that with PI under similar conditions. Optimal conditions for the assay include 0.2 mM substrate, 0.2 mM Ca<sup>2+</sup>, and a mole ratio of hexadecylphosphocholine detergent to substrate of 2.0. A minimum of about 60 ng of pure enzyme can be detected. The apparent bulk <em>K</em><sub>m</sub> for PI-PLC with <span>d</span>-thio-DMPI under these conditions is about 6 <em>μ</em>M. Enzyme activity as a function of surface concentration of substrate shows no sign of saturation up to the maximum mole fraction.</p></div>","PeriodicalId":100162,"journal":{"name":"Biochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1998-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0005-2760(98)00025-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91688493","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}
引用次数: 3
Expression of an active phytoene synthase from Erwinia uredovora and biochemical properties of the enzyme 一种活性植物烯合成酶的表达及酶的生化特性
Biochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism Pub Date : 1998-05-20 DOI: 10.1016/S0005-2760(98)00017-4
Ute Neudert , Isabel M Martı́nez-Férez , Paul D Fraser , Gerhard Sandmann
{"title":"Expression of an active phytoene synthase from Erwinia uredovora and biochemical properties of the enzyme","authors":"Ute Neudert ,&nbsp;Isabel M Martı́nez-Férez ,&nbsp;Paul D Fraser ,&nbsp;Gerhard Sandmann","doi":"10.1016/S0005-2760(98)00017-4","DOIUrl":"10.1016/S0005-2760(98)00017-4","url":null,"abstract":"<div><p>The <em>crtB</em> gene encoding phytoene synthase from the carotenogenic enterobacterium <em>Erwinia uredovora</em> was overexpressed to about 20% of the total cellular protein in <em>Escherichia coli</em>. Formation of the active phytoene synthase had the effect of suppressing the growth of the expressing strain. Presumably inhibition of growth arose from the depletion of the substrate geranylgeranyl pyrophosphate (GGPP) which, in <em>E. coli</em>, is necessary for the synthesis of essential prenylpyrophosphate derivatives. In order to overcome the poor growth characteristics of the phytoene synthase expressing strain, GGPP levels were increased by co-expressing the isoprenoid biosynthetic genes <em>crtE</em> and <em>idi</em>, encoding the <em>Erwinia</em> GGPP synthase and <em>Rhodobacter</em> isopentenyl pyrophosphate isomerase, respectively. The crude enzyme preparation was partially purified 15-fold by chromatography on a DEAE column. A non-radioactive assay was developed that enabled the conversion of GGPP to phytoene. The reaction product was identified by co-chromatography with authentic standards on HPLC systems and comparison of spectral characteristics. The phytoene formed in vitro was present in both a 15-<em>cis</em> and all-<em>trans</em> isomeric configuration. The essential cofactors required were ATP in combinations with either Mn<sup>2+</sup> or Mg<sup>2+</sup>. The <em>K</em><sub>m</sub> value for GGPP was determined as 41 <em>μ</em>M. Phytoene synthesis was inhibited by phosphate ions and squalestatin. The <em>I</em><sub>50</sub> value for the latter inhibitor was 15 <em>μ</em>M. Lineweaver–Burk plots showed constant <em>K</em><sub>m</sub> values in the presence or absence of squalestatin.</p></div>","PeriodicalId":100162,"journal":{"name":"Biochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1998-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0005-2760(98)00017-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20513802","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}
引用次数: 34
Apolipoprotein-mediated cellular cholesterol efflux 载脂蛋白介导的细胞胆固醇外排
Biochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism Pub Date : 1998-05-20 DOI: 10.1016/S0005-2760(98)00032-0
Shinji Yokoyama
{"title":"Apolipoprotein-mediated cellular cholesterol efflux","authors":"Shinji Yokoyama","doi":"10.1016/S0005-2760(98)00032-0","DOIUrl":"10.1016/S0005-2760(98)00032-0","url":null,"abstract":"","PeriodicalId":100162,"journal":{"name":"Biochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1998-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0005-2760(98)00032-0","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20514038","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}
引用次数: 104
Physiological properties and functions of intracellular fatty acid-binding proteins 细胞内脂肪酸结合蛋白的生理特性和功能
Biochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism Pub Date : 1998-04-22 DOI: 10.1016/S0005-2760(97)00205-1
Natalie Ribarik Coe, David A. Bernlohr
{"title":"Physiological properties and functions of intracellular fatty acid-binding proteins","authors":"Natalie Ribarik Coe,&nbsp;David A. Bernlohr","doi":"10.1016/S0005-2760(97)00205-1","DOIUrl":"10.1016/S0005-2760(97)00205-1","url":null,"abstract":"","PeriodicalId":100162,"journal":{"name":"Biochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1998-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0005-2760(97)00205-1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20476486","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}
引用次数: 309
Neuromedin B activates phospholipase D through both PKC-dependent and PKC-independent mechanisms Neuromedin B通过pkc依赖性和pkc非依赖性机制激活磷脂酶D
Biochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism Pub Date : 1998-04-22 DOI: 10.1016/S0005-2760(98)00014-9
Wei Hou, Takaharu Tsuda, Robert T Jensen
{"title":"Neuromedin B activates phospholipase D through both PKC-dependent and PKC-independent mechanisms","authors":"Wei Hou,&nbsp;Takaharu Tsuda,&nbsp;Robert T Jensen","doi":"10.1016/S0005-2760(98)00014-9","DOIUrl":"10.1016/S0005-2760(98)00014-9","url":null,"abstract":"<div><p>The actions of neuromedin B (NMB), a recently discovered mammalian bombesin-related peptide, are mediated by interacting with a distinct receptor; however, little is known about its cellular basis of action. Recent studies show activation of phospholipase D (PLD) is an important transduction cascade for a number of GI hormones, especially for stimulation of growth and protein sorting. The purpose of the present study was to determine whether activation of the NMB receptor causes activation of PLD and to explore whether this activation was coupled to PLC activation. Rat C6 glioblastoma cells (C6 cells), which contain a low density of native NMB receptors and BALB 3T3 cells stably transfected with rat NMB receptors, were used. NMB caused a 3-fold increase in C6 cells and an 11-fold increase in rNMB-R transfected cells in PLD activity. Increases in PLD activity were rapid and NMB was 100-fold more potent than gastrin-releasing peptide (GRP). NMB caused a half-maximal increase in [Ca<sup>2+</sup>]<sub>i</sub> at 0.2 nM, in [<sup>3</sup>H]IP and PLD at 1 nM, and half-maximal receptor occupation at 1.2 nM. TPA increased PLD dose-dependently with a half-maximal effect at 60 nM. The calcium ionophore A23187 (1 <em>μ</em>M) alone did not increase PLD activity but potentiated the effect of TPA. The Ca<sup>2+</sup>-ATPase inhibitor, thapsigargin, did not affect NMB- or TPA-stimulated PLD activities, although it blocked completely the NMB-induced increase in [Ca<sup>2+</sup>]<sub>i</sub>. The PKC inhibitor GF109203X completely abolished TPA-induced PLD activity, however, it only inhibited NMB-induced PLD activity by 20%. The combination of thapsigargin and GF109203X had the same effect as GF109203X alone. These data indicate that NMB receptor activation is coupled to both PLC and PLD. In contrast to a number of other phospholipase C-coupled receptors, NMB receptor stimulated changes in [Ca<sup>2+</sup>]<sub>i</sub> do not contribute to PLD activation. Both PKC-dependent and PKC-independent mechanisms are involved in the NMB-stimulated PLD activation with the PKC-independent pathway predominating.</p></div>","PeriodicalId":100162,"journal":{"name":"Biochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1998-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0005-2760(98)00014-9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20477658","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}
引用次数: 15
Cloning and expression of a group IV cytosolic Ca2+-dependent phospholipase A2 from rat pancreatic islets. Comparison of the expressed activity with that of an islet group VI cytosolic Ca2+-independent phospholipase A2 大鼠胰岛细胞内Ca2+依赖性磷脂酶A2的克隆和表达。与胰岛组胞浆Ca2+非依赖性磷脂酶A2表达活性的比较
Biochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism Pub Date : 1998-04-22 DOI: 10.1016/S0005-2760(98)00027-7
Zhongmin Ma, Sasanka Ramanadham, Zhiqing Hu, John Turk
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引用次数: 54
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