Secretory Phospholipase A2 Mediates Cooperative Prostaglandin Generation by Growth Factor and Cytokine Independently of Preceding Cytosolic Phospholipase A2 Expression in Rat Gastric Epithelial Cells

Akiba, Suminori; Hatazawa, Ryo; Ono, Kyoko; Kitatani, Kazuyuki; Hayama, Misako; Sato, Takashi

doi:10.1074/jbc.m010201200

Cited by 40 publications

(26 citation statements)

References 57 publications

(89 reference statements)

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“…It is well recognized that cPLA 2 is a central regulator of stimulus-coupled cellular AA release, whereas the role of sPLA 2 in the metabolism of AA has remained ambiguous. Nevertheless, different studies have suggested that sPLA 2 IIA, or related sPLA 2 isozymes, could participate in immediate and delayed phases of cellular AA release and PG generation (Pfeilschifter et al 1993, Akiba et al 2001. However, little is known regarding how the expression and the activity of uterine PLA 2 enzymes change during pregnancy.…”

Section: Discussionmentioning

confidence: 99%

Secretory and cytosolic phospholipase A2 activities and expression are regulated by oxytocin and estradiol during labor

Farina¹,

Billi²,

Leguizamón³

et al. 2007

Reproduction

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The release of arachidonic acid from membrane glycerophospholipids through the action of phospholipases (PLs) is the first step in the biosynthesis of prostaglandins (PGs). In reproductive tissues, the most important PLs are cytosolic PLA 2 (cPLA 2 ) and types IIA and V of the secretory isoform (sPLA 2 ). The aim of this work was to investigate the role of ovarian steroid hormones and oxytocin (OT) in the regulation of rat uterine PLA 2 activity and expression during pregnancy and labor. The activity of sPLA 2 increased near labor, whereas cPLA 2 activity augmented towards the end of gestation. The levels of sPLA 2 IIA and cPLA 2 mRNA showed an increase before labor (P!0.05, day 21), whereas sPLA 2 V mRNA was not regulated during pregnancy. The administration of atosiban (synthetic OT antagonist) together with tamoxifen (antagonist of estrogen receptors) was able to decrease cytosolic and secretory PLA 2 activities, diminish the expression of sPLA 2 IIA and cPLA 2 , as well as decrease PGF 2a production before the onset of labor (P!0.01). The ovarian steroid did not affect PLA 2 during pregnancy. Collectively, these findings indicate that in the rat uterus, both 17b-estradiol and OT could be regulating the activity and the expression of the secretory and the cytosolic isoforms of PLA 2 , thus controlling PGF 2a synthesis prior to the onset of labor. Reproduction (2007) 134 355-364

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Section: Discussionmentioning

confidence: 99%

Secretory and cytosolic phospholipase A2 activities and expression are regulated by oxytocin and estradiol during labor

Farina¹,

Billi²,

Leguizamón³

et al. 2007

Reproduction

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“…The cells were cultured for 24 h, and then the cells were treated with various doses of the prostaglandins with/without NGF or PGE 2 and PGD 2 antagonists in the presence of [ 3 H]arachidonic acid (0.4 Ci/ml; PerkinElmer Life Sciences, Boston, MA) for 48 h. The generation of prostaglandins was determined in the medium and cells as described by Akiba et al (2001). In brief, prostaglandins were extracted and separated by thin-layer chromatography on a Silica Gel G plate using development solution [ethyl acetate/isooctane/acetic acid/water (110:50:20:100, v/v)].…”

Section: Methodsmentioning

confidence: 99%

Activation of p38 Mitogen-Activated Protein Kinase and Activator Protein-1 during the Promotion of Neurite Extension of PC-12 Cells by 15-Deoxy-Δ^12,14-prostaglandin J₂

Jung

Park²,

Oh³

et al. 2003

Mol Pharmacol

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15-Deoxy-⌬12,14 -prostaglandin J 2 (15-deoxy-PGJ 2 ), a naturally occurring ligand, activates the peroxisome proliferator-activated receptor-␥ (PPAR-␥). Activation of PPAR-␥ has been found to induce cell differentiation in such cells as adipose cells and macrophages. Herein, we investigated whether 15-deoxy-PGJ 2 has neuronal cell differentiation and possible underlying molecular mechanisms. Dopaminergic differentiating PC-12 cells treated with 15-deoxy-PGJ 2 (0.2 to 1.6 M) alone showed measurable neurite extension and expression of neurofilament, a marker of cell differentiation. However, a much greater extent of neurite extension and expression of neurofilament was observed in the presence of NGF (50 ng/ml). In parallel with its increasing effect on the neurite extension and expression of neurofilament, 15-deoxy-PGJ 2 enhanced NGF-induced p38 MAP kinase expression and its phosphorylation in addition to the activation of transcription factor AP-1 in a dose-dependent manner. Moreover, pretreatment of 4-(4-fluorophenyl)-2-(4-methylsulfinylphenyl)-5-(pyridyl)1H-imidazole (SB203580), a specific inhibitor of p38 MAP kinase, inhibited the promoting effect of 15-deoxy-PGJ 2 (0.8 M) on NGF-induced neurite extension. This inhibition correlated well with the ability of SB203580 to inhibit the enhancing effect of 15-deoxy-PGJ 2 on the expression of p38 MAP kinase and activation of AP-1. The promoting ability of 15-deoxy-PGJ 2 did not occur through PPAR-␥ because synthetic PPAR-␥ agonist and antagonist did not change the neurite-promoting effect of 15-deoxy-PGJ 2 . In addition, contrast to other cells (embryonic midbrain and neuroblastoma SK-N-MC cells), PPAR-␥ was not expressed in PC-12 cells. Other structure-related prostaglandins (PGD 2 and PGE 2 ) acting via a cell surface G-protein-coupled receptor (GPCR) did not increase basal or NGF-induced neurite extension. Moreover, GPCR (PGE 2 and PGD 2 receptors) antagonists did not alter the promoting effect of 15-deoxy-PGJ 2 on neurite extension and activation of p38 MAP kinase, suggesting that the promoting effect of 15-deoxy-PGJ 2 may not be mediated by GPCR either. These data demonstrate that activation of p38

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“…Dexamethasone, a glucocorticoid, reduced cPLA 2 ␣ activity by up-regulation of p11 in human epithelial cells (39). It was also reported that transforming growth factor-␣ inhibited A23187-induced AA release by increasing p11-cPLA 2 ␣ binding (40,41). Collectively, these data suggest that p11 may play a role in regulating cPLA 2 ␣ activity and AA release.…”

mentioning

confidence: 69%

Mechanism of Regulation of Group IVA Phospholipase A2 Activity by Ser727 Phosphorylation

Tian

Wijewickrama

Kim

et al. 2008

Journal of Biological Chemistry

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Although group IVA cytosolic phospholipase A 2 (cPLA 2 ␣) has been reported to be phosphorylated at multiple Ser residues, the mechanisms by which phosphorylation at different sites regulates cPLA 2 ␣ activities are not fully understood. To explore the possibility that phosphorylation of Ser 727 modulates cellular protein-protein interactions, we measured the effect of Ser 727 mutations on the interaction of cPLA 2 ␣ with a reported cPLA 2 ␣-binding protein, p11. In vitro activity assays and membrane binding measurements by surface plasmon resonance analysis showed that a heterotetramer (A2t) of p11 and annexin A2, but not p11 or annexin A2 alone, directly binds cPLA 2 ␣ via Ser 727 , which keeps the enzyme from binding the membrane and catalyzing the phospholipid hydrolysis. Phosphorylation of Ser 727 disrupts this inhibitory cPLA 2 ␣-A2t interaction, thereby activating cPLA 2 ␣. Subcellular translocation and activity measurements in HEK293 cells cotransfected with cPLA 2 ␣ and p11 also showed that p11, in the form of A2t, inhibits cPLA 2 ␣ by the same mechanism and that phosphorylation of Ser 727 activates cPLA 2 ␣ by interfering with the inhibitory cPLA 2 ␣-A2t interaction. Collectively, these studies provide new insight into the regulatory mechanism of cPLA 2 ␣ through Ser 727 phosphorylation.

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Secretory Phospholipase A2 Mediates Cooperative Prostaglandin Generation by Growth Factor and Cytokine Independently of Preceding Cytosolic Phospholipase A2 Expression in Rat Gastric Epithelial Cells

Cited by 40 publications

References 57 publications

Secretory and cytosolic phospholipase A2 activities and expression are regulated by oxytocin and estradiol during labor

Secretory and cytosolic phospholipase A2 activities and expression are regulated by oxytocin and estradiol during labor

Activation of p38 Mitogen-Activated Protein Kinase and Activator Protein-1 during the Promotion of Neurite Extension of PC-12 Cells by 15-Deoxy-Δ^12,14-prostaglandin J₂

Mechanism of Regulation of Group IVA Phospholipase A2 Activity by Ser727 Phosphorylation

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Secretory Phospholipase A2 Mediates Cooperative Prostaglandin Generation by Growth Factor and Cytokine Independently of Preceding Cytosolic Phospholipase A2 Expression in Rat Gastric Epithelial Cells

Cited by 40 publications

References 57 publications

Secretory and cytosolic phospholipase A2 activities and expression are regulated by oxytocin and estradiol during labor

Secretory and cytosolic phospholipase A2 activities and expression are regulated by oxytocin and estradiol during labor

Activation of p38 Mitogen-Activated Protein Kinase and Activator Protein-1 during the Promotion of Neurite Extension of PC-12 Cells by 15-Deoxy-Δ12,14-prostaglandin J2

Mechanism of Regulation of Group IVA Phospholipase A2 Activity by Ser727 Phosphorylation

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Activation of p38 Mitogen-Activated Protein Kinase and Activator Protein-1 during the Promotion of Neurite Extension of PC-12 Cells by 15-Deoxy-Δ^12,14-prostaglandin J₂