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

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Addendum to ‘Modulation of cell signalling by ceramides’ “神经酰胺调节细胞信号传导”附录
Biochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism Pub Date : 1998-11-02 DOI: 10.1016/S0005-2760(98)00116-7
Antonio Gómez-Muñoz
{"title":"Addendum to ‘Modulation of cell signalling by ceramides’","authors":"Antonio Gómez-Muñoz","doi":"10.1016/S0005-2760(98)00116-7","DOIUrl":"10.1016/S0005-2760(98)00116-7","url":null,"abstract":"","PeriodicalId":100162,"journal":{"name":"Biochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1998-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0005-2760(98)00116-7","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73568906","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: 2
Effect of methylglyoxal on the physico-chemical and biological properties of low-density lipoprotein 甲基乙二醛对低密度脂蛋白理化及生物学特性的影响
Biochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism Pub Date : 1998-11-02 DOI: 10.1016/S0005-2760(98)00112-X
Casper G. Schalkwijk , Mario A. Vermeer , Coen D.A. Stehouwer , Johan te Koppele , Hans M.G. Princen , Victor W.M. van Hinsbergh
{"title":"Effect of methylglyoxal on the physico-chemical and biological properties of low-density lipoprotein","authors":"Casper G. Schalkwijk ,&nbsp;Mario A. Vermeer ,&nbsp;Coen D.A. Stehouwer ,&nbsp;Johan te Koppele ,&nbsp;Hans M.G. Princen ,&nbsp;Victor W.M. van Hinsbergh","doi":"10.1016/S0005-2760(98)00112-X","DOIUrl":"10.1016/S0005-2760(98)00112-X","url":null,"abstract":"<div><p>In patients with diabetes, non-enzymatic glycation of low-density lipoprotein (LDL) has been suggested to be involved in the development of atherosclerosis. α-Dicarbonyl compounds were identified as intermediates in the non-enzymatic glycation and increased levels were reported in patients with diabetes. We studied the effect of the α-dicarbonyl compound methylglyoxal (MG) on the physicochemical and biological properties of LDL. MG dose-dependently modifies LDL, as indicated by the formation of fluorescent products and the increase of a net negative charge. MG (10 mmol/l) induced major modifications of arginine residues (up to 85%) and minor lysine modifications (less than 6%). MG-LDL preparations generated small amounts of superoxide anion radicals as measured by the reduction of cytochrome <em>c</em>, but this was not accompanied by peroxidation of the polyunsaturated fatty acids of MG-LDL. MG-LDL showed diminished recognition and uptake by the human LDL receptor in cultured cells and a markedly increased plasma clearance rate in vivo in rats. The reduced association and degradation of <sup>125</sup>I-oxidised LDL by murine macrophages indicates recognition of MG-LDL by a scavenger receptor. Surprisingly, MG-LDL caused significantly less cholesteryl ester synthesis in murine macrophages, as compared to native LDL and oxidised or acetylated LDL. Highly modified MG-LDL did not induce activation of human endothelial cells, as measured by the expression of monocyte chemoattractant protein-1 and vascular cell adhesion molecule-1.</p></div>","PeriodicalId":100162,"journal":{"name":"Biochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1998-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0005-2760(98)00112-X","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20706470","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: 24
Elevation of cyclic AMP decreases phosphoinositide turnover and inhibits thrombin-induced secretion in human platelets 升高的环AMP减少磷酸肌肽的周转和抑制人血小板中凝血酶诱导的分泌
Biochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism Pub Date : 1998-11-02 DOI: 10.1016/S0005-2760(98)00106-4
Anita Ryningen, Baard Olav Jensen, Holm Holmsen
{"title":"Elevation of cyclic AMP decreases phosphoinositide turnover and inhibits thrombin-induced secretion in human platelets","authors":"Anita Ryningen,&nbsp;Baard Olav Jensen,&nbsp;Holm Holmsen","doi":"10.1016/S0005-2760(98)00106-4","DOIUrl":"10.1016/S0005-2760(98)00106-4","url":null,"abstract":"<div><p>Elevation of cyclic AMP (cAMP) in platelets inhibits agonist-induced, G protein-mediated responses and activation of polyphosphoinositide-specific phospholipase C (PLC) by ill-defined mechanism(s). Signal transduction steps downstream of PLC are inhibited by elevated cAMP, suggesting an inhibitory effect of cAMP, via protein kinase A, on PLC. In [<sup>32</sup>P]<sub>i</sub>-prelabeled platelets, forskolin increased intracellular cAMP (104 nmol/10<sup>11</sup> cells at 10<sup>−5</sup> M forskolin) and [<sup>32</sup>P]phosphatidylinositol 4-phosphate (Δ[<sup>32</sup>P]PIP) (30% at 10<sup>−7</sup>–10<sup>−6</sup> M forskolin). The thrombin-induced (0.1 U/ml) increase in production of [<sup>32</sup>P]PA, ‘overshoots’ in [<sup>32</sup>P]PIP and [<sup>32</sup>P]PIP<sub>2</sub> ([<sup>32</sup>P]phosphatidylinositol 4,5-bisphosphate), and the increase in [<sup>32</sup>P]PI and secretion of ADP+ATP were abolished by forskolin (10<sup>−7</sup> M). Forskolin stimulated total [<sup>32</sup>P]P<sub>i</sub> uptake in resting platelets (48%), increased <sup>32</sup>P incorporation into PIP (110%), and inhibited <sup>32</sup>P incorporation into PI (50%). The latter inhibition was most likely considerably greater due to the forskolin-induced stimulation of [<sup>32</sup>P]P<sub>i</sub> uptake. The changes in radioactive PA, PIP and PIP<sub>2</sub> are regarded as being proportional with their masses in the prelabeled platelets, while the increase in PI (phosphatidylinositol) is regarded as a change in specific radioactivity, and hence in its synthesis. The results suggest that cAMP elevation inhibits the flux in the polyphosphoinositide cycle through both inhibition of PIP 5-kinase and PI synthesis. The inverse relation between forskolin-produced ΔPIP and [<sup>32</sup>P]PA production suggests that the PLC reaction is inhibited by elevated cAMP through reduction of substrate (PIP<sub>2</sub>) resynthesis, and not by inhibition of the PLC enzyme.</p></div>","PeriodicalId":100162,"journal":{"name":"Biochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1998-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0005-2760(98)00106-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20707463","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: 35
Anandamide synthesis is induced by arachidonate mobilizing agonists in cells of the immune system 花生四烯酸动员激动剂在免疫系统细胞中诱导阿南达胺合成
Biochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism Pub Date : 1998-11-02 DOI: 10.1016/S0005-2760(98)00110-6
Vasumati K. Pestonjamasp , Sumner H. Burstein
{"title":"Anandamide synthesis is induced by arachidonate mobilizing agonists in cells of the immune system","authors":"Vasumati K. Pestonjamasp ,&nbsp;Sumner H. Burstein","doi":"10.1016/S0005-2760(98)00110-6","DOIUrl":"10.1016/S0005-2760(98)00110-6","url":null,"abstract":"<div><p>The hypothesis that the capability of agents to mobilize arachidonic acid (AA) could predict increased anandamide (ANA) synthesis in a macrophage cell line has been examined. Lipopolysaccharide (LPS), platelet-activating factor (PAF) and cannabinoids such as Δ<sup>9</sup>-tetrahydrocannabinol (THC) and anandamide were all found to be agonists for the release of AA and led to increased ANA synthesis in RAW264.7 mouse macrophage cells. Nitric oxide, in contrast, stimulated AA release without raising ANA levels. ANA stimulation of its own synthesis indicates the existence of a positive feedback mechanism. The possible involvement of the CB2 receptor in THC-mediated AA release and ANA synthesis is addressed using the antagonist SR144528. ANA synthesis is also increased by the combination of calcium ionophore and indomethacin, suggesting that ANA is metabolized by a cyclooxygenase in this system. The data imply that ANA could play a role in the response of the immune system to cannabinoids and bacterial endotoxins and that AA mobilization is a predictor for increased ANA synthesis.</p></div>","PeriodicalId":100162,"journal":{"name":"Biochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1998-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0005-2760(98)00110-6","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20707467","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: 114
UDP-glucuronosyltransferases in human intestinal mucosa 人肠黏膜udp -葡萄糖醛酸转移酶
Biochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism Pub Date : 1998-11-02 DOI: 10.1016/S0005-2760(98)00115-5
Anna Radominska-Pandya , Joanna M. Little , Jay T. Pandya , Thomas R. Tephly , Christopher D. King , Gary W. Barone , Jean-Pierre Raufman
{"title":"UDP-glucuronosyltransferases in human intestinal mucosa","authors":"Anna Radominska-Pandya ,&nbsp;Joanna M. Little ,&nbsp;Jay T. Pandya ,&nbsp;Thomas R. Tephly ,&nbsp;Christopher D. King ,&nbsp;Gary W. Barone ,&nbsp;Jean-Pierre Raufman","doi":"10.1016/S0005-2760(98)00115-5","DOIUrl":"10.1016/S0005-2760(98)00115-5","url":null,"abstract":"<div><p>While UDP-glucuronosyltransferases (UGTs) are known to be expressed at high levels in human liver, relatively little is known about extrahepatic expression. In the present study, UGT2B family isoforms involved in the glucuronidation of steroid hormones and bile acids have been characterized in microsomes prepared from jejunum, ileum and colon from six human subjects. Glucuronidation of androsterone and testosterone was highly significant and increased from proximal to distal intestine. In contrast, hyodeoxycholic acid was glucuronidated at a low level in jejunum and ileum and activity was barely detectable in colon. No significant glucuronidation of lithocholic acid was found. Small phenols were glucuronidated with much lower activity than found in liver. High levels of UGT protein were detected with polyclonal anti-rat androsterone- and testosterone-UGT antibodies, whereas UGT2B4, a major hepatic hyodeoxycholic acid-specific UGT, was undetectable using a highly specific anti-human UGT2B4 antibody. Screening for RNA expression by RT-PCR confirmed the absence of UGT2B4 and UGT1A6 and showed expression of UGT2B7, a hepatic isoform shown to glucuronidate androsterone, in all intestinal segments. To our knowledge, the presence of functional androsterone and testosterone directed isoforms in human intestine is a novel finding which supports the idea that the intestinal tract functions as a steroid-metabolizing organ and plays a significant role in steroid hormone biotransformation.</p></div>","PeriodicalId":100162,"journal":{"name":"Biochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1998-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0005-2760(98)00115-5","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20707605","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: 120
Cholesterol synthesis is increased in mixed hyperlipidaemia 混合性高脂血症中胆固醇合成增加
Biochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism Pub Date : 1998-11-02 DOI: 10.1016/S0005-2760(98)00103-9
R.P. Naoumova , K.-D. Kim , C. Neuwirth , S. Niththyananthan , N.B. Rendell , G.W. Taylor , G.R. Thompson
{"title":"Cholesterol synthesis is increased in mixed hyperlipidaemia","authors":"R.P. Naoumova ,&nbsp;K.-D. Kim ,&nbsp;C. Neuwirth ,&nbsp;S. Niththyananthan ,&nbsp;N.B. Rendell ,&nbsp;G.W. Taylor ,&nbsp;G.R. Thompson","doi":"10.1016/S0005-2760(98)00103-9","DOIUrl":"10.1016/S0005-2760(98)00103-9","url":null,"abstract":"<div><p>We showed previously that hypertriglyceridaemia, but not hypercholesterolaemia, is correlated with increases in cholesterol synthesis and apolipoprotein B secretion in patients with secondary hypertriglyceridaemia. The aim of the present study was to compare the rate of cholesterol synthesis, using fasting plasma mevalonic acid (MVA) as an index, in patients with primary mixed hyperlipidaemia (type IIb phenotype, <em>n</em>=45) and primary hypercholesterolaemia (type IIa phenotype, <em>n</em>=92). LDL cholesterol was significantly higher in types IIa (6.38±0.18 mmol/l) and IIb (5.89±0.25 mmol/l) compared to 40 normolipidaemic controls (2.99±0.1 mmol/l, <em>P</em>&lt;0.0001), whereas serum triglyceride was higher in type IIb (2.62 (range 2.2–3.0) mmol/l) than type IIa (1.22 (range 0.85–1.60) mmol/l, <em>P</em>&lt;0.001) and controls (0.90 (range 0.68–1.24) mmol/l, <em>P</em>&lt;0.001). Similarly, MVA was higher in type IIb (7.0±0.46 ng/ml) than IIa (5.6±0.23 ng/ml, <em>P</em>&lt;0.0) and controls (5.6±0.36 ng/ml, <em>P</em>&lt;0.05). Plasma MVA correlated positively with serum triglyceride (<em>r</em>=0.22, <em>P</em>=0.004) and negatively with LDL cholesterol (<em>r</em>=−0.21, <em>P</em>=0.014). These results are in accordance with previous observations that VLDL-apolipoprotein B secretion and cholesterol synthesis are linked and demonstrate that the latter is increased in mixed hyperlipidaemia.</p></div>","PeriodicalId":100162,"journal":{"name":"Biochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1998-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0005-2760(98)00103-9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20706613","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
The level of 7-dehydrocholesterol in plasma reflects the activity of 3-hydroxy-3-methylglutaryl coenzyme A reductase in the human liver 血浆中7-脱氢胆固醇的水平反映了肝脏中3-羟基-3-甲基戊二酰辅酶A还原酶的活性
Biochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism Pub Date : 1998-11-02 DOI: 10.1016/S0005-2760(98)00104-0
Magnus Axelson , Bo Angelin , Carl-Gustaf Hillebrant , Eva Reihnér , Curt Einarsson
{"title":"The level of 7-dehydrocholesterol in plasma reflects the activity of 3-hydroxy-3-methylglutaryl coenzyme A reductase in the human liver","authors":"Magnus Axelson ,&nbsp;Bo Angelin ,&nbsp;Carl-Gustaf Hillebrant ,&nbsp;Eva Reihnér ,&nbsp;Curt Einarsson","doi":"10.1016/S0005-2760(98)00104-0","DOIUrl":"10.1016/S0005-2760(98)00104-0","url":null,"abstract":"<div><p>Plasma levels of the cholesterol precursor 7-dehydrocholesterol (7-DHC) were compared with activities of the rate-limiting enzyme in cholesterol biosynthesis, 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase assayed in liver biopsies from patients undergoing cholecystectomy. Some patients were treated with cholestyramine, deoxycholic acid or chenodeoxycholic acid prior to surgery in order to alter the activity of the enzyme. The median level of 7-DHC and the activity of HMG-CoA reductase in the untreated group were 55 ng/ml and 98 pmol/min/mg protein, respectively. The sterol levels and enzyme activities were increased in patients treated with cholestyramine (85 ng/ml and 439 pmol/min/mg protein) and deoxycholic acid (86 ng/ml and 173 pmol/min/mg protein) and decreased in patients treated with chenodeoxycholic acid (38 ng/ml and 51 pmol/min/mg protein). There was a strong positive correlation (<em>r</em><sub>s</sub>=0.75, <em>P</em>&lt;0.0005) between the plasma levels of 7-DHC and the activities of hepatic HMG-CoA reductase in these patients. This correlation was further improved when the plasma levels of 7-DHC were expressed relative to those of cholesterol (<em>r</em><sub>s</sub>=0.90, <em>P</em>&lt;0.0001). The results show that the level of 7-DHC in plasma reflects the activity of HMG-CoA reductase in the liver.</p></div>","PeriodicalId":100162,"journal":{"name":"Biochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1998-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0005-2760(98)00104-0","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20706615","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: 8
Inductive electron-withdrawal from ammonium ion headgroups of cationic lipids and the influence on DNA transfection 阳离子脂质铵离子头基的诱导电子抽离及其对DNA转染的影响
Biochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism Pub Date : 1998-11-02 DOI: 10.1016/S0005-2760(98)00114-3
Michael H. Nantz , Ling Li , Ji Zhu , Kim L. Aho-Sharon , Debora Lim , Kent L. Erickson
{"title":"Inductive electron-withdrawal from ammonium ion headgroups of cationic lipids and the influence on DNA transfection","authors":"Michael H. Nantz ,&nbsp;Ling Li ,&nbsp;Ji Zhu ,&nbsp;Kim L. Aho-Sharon ,&nbsp;Debora Lim ,&nbsp;Kent L. Erickson","doi":"10.1016/S0005-2760(98)00114-3","DOIUrl":"10.1016/S0005-2760(98)00114-3","url":null,"abstract":"<div><p>We have prepared a panel of lipidic ammonium tetrafluoroborate salts that contain trifluoromethyl, trichloromethyl, and methyl groups attached to the headgroup. <sup>19</sup>F-NMR analyses of the cationic lipid panel revealed that the differences in electron-withdrawal from the ammonium ion headgroup accounted for differences in ion-pairing. Exchange of the tetrafluoroborate counterion by complexation to DNA-phosphate of a reporter gene enabled us to probe the influence of inductive electron-withdrawal in cationic lipid-mediated DNA transfection. We tested the lipid panel for transfection activity in two cell lines. The results indicate that the inductive effects of electron-withdrawing functionality diminish transfection activity in modest (2–4-fold) increments. The present study suggests that the mechanism whereby poly(alcohol)- or poly(ether)-substituted headgroups improve DNA transfection is not based on electronic activation of the ammonium ion.</p></div>","PeriodicalId":100162,"journal":{"name":"Biochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1998-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0005-2760(98)00114-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20706964","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: 10
Differential activation of human neutrophil cytosolic phospholipase A2 and secretory phospholipase A2 during priming by 1,2-diacyl- and 1-O-alkyl-2-acylglycerols 1,2-二酰基和1- o -烷基-2-酰基甘油在启动过程中对人中性粒细胞胞浆磷脂酶A2和分泌磷脂酶A2的差异激活
Biochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism Pub Date : 1998-11-02 DOI: 10.1016/S0005-2760(98)00111-8
Michael C. Seeds , Andrew B. Nixon , Robert L. Wykle , David A. Bass
{"title":"Differential activation of human neutrophil cytosolic phospholipase A2 and secretory phospholipase A2 during priming by 1,2-diacyl- and 1-O-alkyl-2-acylglycerols","authors":"Michael C. Seeds ,&nbsp;Andrew B. Nixon ,&nbsp;Robert L. Wykle ,&nbsp;David A. Bass","doi":"10.1016/S0005-2760(98)00111-8","DOIUrl":"10.1016/S0005-2760(98)00111-8","url":null,"abstract":"<div><p>We have shown previously that both 1,2-diacylglycerol (AAG) and 1-<em>O</em>-alkyl-2-acylglycerol (EAG) prime neutrophil release of arachidonic acid via uncharacterized phospholipases A<sub>2</sub>. Therefore, we investigated the actions of EAG and AAG specifically on neutrophil cytosolic (cPLA<sub>2</sub>) and secretory (sPLA<sub>2</sub>) phospholipase A<sub>2</sub>s. We hypothesized that AAG as a protein kinase activator would activate cPLA<sub>2</sub> via phosphorylation events. EAG is antagonistic to the AAG activation of PKC, thus it was not expected to act via phosphorylation of cPLA<sub>2</sub>. Neutrophils were primed with either AAG or EAG and then stimulated with fMLP. When neutrophils were primed with 5–20 μM 1,2-diacylglycerol, a shift was observed in cPLA<sub>2</sub> migration on SDS-PAGE gels, consistent with phosphorylation of the protein. This gel shift was not seen after exposure to EAG. AAG also caused a parallel increase in enzymatic activity of cPLA<sub>2</sub> that was not seen with EAG. We also investigated whether either diglyceride would cause similar priming or direct secretion of sPLA<sub>2</sub>. Both AAG and EAG directly caused significant secretion of neutrophil sPLA<sub>2</sub>. EAG also increased the release of sPLA<sub>2</sub> in cells subsequently stimulated with fMLP. Thus, AAG activated cPLA<sub>2</sub> and stimulated secretion of sPLA<sub>2</sub>. In contrast, EAG did not activate cPLA<sub>2</sub>, but directly activated secretion of sPLA<sub>2</sub>. We also demonstrated that human synovial fluid sPLA<sub>2</sub> increased AA release from resting and fMLP-stimulated neutrophils. Given that diglycerides prime for release of AA, PAF, and LTB<sub>4</sub>, these current data support the hypothesis that such priming may be mediated by phosphorylation dependent (cPLA<sub>2</sub>) or phosphorylation independent (e.g. secretion of sPLA<sub>2</sub>) events.</p></div>","PeriodicalId":100162,"journal":{"name":"Biochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1998-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0005-2760(98)00111-8","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20706966","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: 11
Alterations in the biosynthesis of cholesterol, dolichol and dolichyl-P in the genetic cholesterol homeostasis disorder, Niemann–Pick type C disease 遗传胆固醇稳态紊乱,尼曼-匹克C型病中胆固醇、多酚和多酚- p生物合成的改变
Biochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism Pub Date : 1998-11-02 DOI: 10.1016/S0005-2760(98)00108-8
Sophia Schedin , Maria Nilsson , Tadeusz Chojnacki , Gustav Dallner
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引用次数: 11
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