Secretory Type II PLA2Immunoreactivity and PLA2Enzymatic Activity in Human Gestational Tissues Before, During and After Spontaneous-onset Labour at Term

Munns, Melinda J; Farrugia, William; King, Roger G; Rice, Gregory E.

doi:10.1053/plac.1998.0341

Cited by 14 publications

(5 citation statements)

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“…However, information is still scarce as to the signaling mechanisms involved in COX-2 regulation during labor. Previous reports have demonstrated that COX-2 induction by IL-1␤ is mediated by PKC (Lin et al, 2000;Molina-Holgado et al, 2000), PLA 2 (Hansen et al, 1999;Munns et al, 1999) and tyrosine kinase (Akarasereenont and Thiemermann, 1996;Yucel-Lindberg et al, 1999). In addition, it has been suggested that PLD is one of the regulators of COX-2 expression.…”

Section: Pld As a Mediator Of Il-1␤-induced Cox-2 Expression 617mentioning

confidence: 96%

“…IL-1␤ is also a known promoter of PGE 2 production in amnion cells (Albert et al, 1994). Previously, it was suggested that the secretory PLA 2 is the primary phospholipase involved in PG production (Munns et al, 1999). Other groups have documented that the cytosolic PLA 2 is the predominant phospholipase involved in PG production (Hansen et al, 1999;Wang et al, 2001).…”

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confidence: 99%

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Regulation of Cyclooxygenase-2 Expression by Phospholipase D in Human Amnion-Derived WISH Cells

Park

Bae²,

Nam³

et al. 2002

Mol Pharmacol

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Prostaglandins (PGs) are known to play a key role in the initiation of labor, but the mechanisms regulating their synthesis in amnion are largely unknown. In this study, the regulatory mechanisms for PGE 2 production during phospholipase D (PLD) and p38-dependent activation of WISH cells were investigated. We found that the stimulation of WISH cells with interleukin (IL)-1␤ elicited dose-dependent synthesis of cyclooxygenase-2 (COX-2) mRNA, protein, and their products, PGE 2 . Moreover, the treatment of [ 3 H]myristate-labeled cells in the presence of 1-butanol caused the dose-dependent formation of [ 3 H]phosphatidylbutanol (PBt), a product specific to PLD activity. Pretreating the cells with 1-butanol and Ro 31-8220 inhibited the IL-1␤-induced COX-2 expression, but 3-butanol did not affect this response. In addition, evidence that PLD was involved in the stimulation of COX-2 expression was provided by the observations that COX-2 expression was stimulated by the dioctanoyl phosphatidic acid (PA) and that the prevention of PA dephosphorylation by 1-propranolol potentiated COX-2 expression by IL-1␤. Moreover, IL-1␤ stimulation of the cells caused the phosphorylation of p38 and extracellular signalregulated kinase (ERK), and IL-1␤-induced COX-2 expression was inhibited by the pretreatment of WISH cells with a p38 inhibitor, in contrast ERK upstream inhibitor had no effect. Furthermore, Ro 31-8220 inhibited IL-1␤-induced p38 phosphorylation but not ERK phosphorylation. The results of this study indicate that in human amnion cells, IL-1␤ might activate PLD through an upstream protein kinase C to elicit p38 and finally induce COX-2 expression.

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Section: Pld As a Mediator Of Il-1␤-induced Cox-2 Expression 617mentioning

confidence: 96%

mentioning

confidence: 99%

Regulation of Cyclooxygenase-2 Expression by Phospholipase D in Human Amnion-Derived WISH Cells

Park

Bae²,

Nam³

et al. 2002

Mol Pharmacol

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“…20,21 To our knowledge, only 3 of the known PLA 2 enzymes have been identified and partially characterized in the pregnant human uterus, including sPLA 2 -IIA, sPLA 2 -V, and cPLA 2 -IV. 22,23 These isoforms are differentially expressed and regulated throughout pregnancy and parturition, [24][25][26][27][28][29] suggesting different downstream cellular effects. However, these changes do not account for the overall increase in PLA 2 activity observed during pregnancy, suggesting the presence of other PLA 2 enzymes within the pregnant uterus.…”

Section: Introductionmentioning

confidence: 99%

Regulation of sPLA2-IID in Human Decidua: Insights Into the Complexity of the Prostaglandin Pathway in Labor

et al. 2014

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Prostaglandins are implicated in the labor process, yet the precise role and regulation of the prostaglandin pathway remains to be elucidated. The first step in the pathway is cleavage of membrane phospholipids by phospholipase A 2 (PLA 2 ). Previous work demonstrated upregulation of secretory PLA 2 (sPLA 2 )-IIA with labor in human myometrium, and recent evidence shows that there are numerous PLA 2 isoforms. The present study investigates the potential of additional sPLA 2 isoforms during pregnancy and labor. Real-time reverse transcriptase-polymerase chain reaction (RT-PCR), Western blotting, and immunohistochemistry were used to determine sPLA 2 expression and localization. Results show the presence of sPLA 2 -IID in amnion, chorion, placenta, decidua, and myometrium. Expression of sPLA 2 -IID in decidua was significantly decreased in term labor compared to nonlabor patients, whereas no significant labor-associated changes were observed in other gestational tissues. Secretory PLA 2 -IID was localized within chorion fibroblasts, placenta trophoblasts, decidual cells, and in myometrial smooth muscle cells. In primary decidual cell cultures, interleukin (IL) 10 (IL-10) increased sPLA 2 -IID messenger RNA (mRNA) expression, while IL-1b had no effect on sPLA 2 -IID mRNA expression. In conclusion, decreased expression of sPLA 2 -IID in the decidua at labor indicates that it is unlikely to contribute to increased prostaglandin production during labor. However, increased expression of sPLA 2 -IID, induced by IL-10, suggests that sPLA 2 -IID may play an important anti-inflammatory role at the maternal-fetal interface. Nevertheless, precise functions of sPLA 2 -IID within the human uterus remain to be determined.

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“…The regulatory factors involved in maintaining the gestational uterine environment and the events leading to parturition are complex, interdependent, and species-specific. However, common components to the onset of parturition in both humans and rodents involve the mobilization of arachidonic acid from glycerophospholipids [1,2]. Arachidonic acid and several of its eicosanoid metabolites are capable of stimulating uterine function [2][3][4].…”

Section: Introductionmentioning

confidence: 99%

“…However, common components to the onset of parturition in both humans and rodents involve the mobilization of arachidonic acid from glycerophospholipids [1,2]. Arachidonic acid and several of its eicosanoid metabolites are capable of stimulating uterine function [2][3][4]. Phospholipase A2 (PLA2) enzymes catalyze this rate-limiting step in eicosanoid formation.…”

Section: Introductionmentioning

confidence: 99%

Gestation Age-Related Increase in 50-kDa Rat Uterine Calcium-Independent Phospholipase A2 Expression Influences Uterine Sensitivity to Polychlorinated Biphenyl Stimulation1

Brant

Guan

Tithof

et al. 2006

Biology of Reproduction

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Phospholipase A2 (PLA2) enzymes catalyze the rate-limiting step in eicosanoid production by liberating arachidonic acid from membrane phospholipids. There is limited information regarding the expression pattern and activity of uterine PLA2 enzymes during pregnancy. Polychlorinated biphenyls (PCBs) are a group of persistent environmental toxicants previously associated with decreased gestation length that are capable of activating PLA2. The purpose of the present study was to determine whether uterine sensitivity to PCB stimulation is dependent on PLA2 expression, comparing rat uterine PLA2 expression in Gestational Day (gd) 10 versus gd20. Western blot analysis revealed a significant increase in the expression of calcium-dependent PLA2G2A and a 50-kDa protein immunoreactive to calcium-independent PLA2G6 antibody in gd20 compared to gd10 rat uterine tissue. The increased expression of the 50-kDa PLA2G6 was associated with a gestational age-related increase in endometrial calcium-independent PLA2 activity that was sensitive to inhibition by bromoenol lactone (P < 0.05). Longitudinal uterine strips isolated from gd10 or gd20 rat were suspended in muscle baths to evaluate uterine contractions following exposure to the ortho substituted congener PCB 50. Exposure to 50 and 100 microM PCB 50 significantly increased the frequency of gd20, but not gd10, uteri compared to solvent (dimethyl sulfoxide) controls (P < 0.05). Pharmacologic inhibition of PLA2G6, but not PLA2G2A, attenuated PCB-induced stimulation of gd20 uterine contractions (P < 0.05). These data suggest that PCB 50 stimulates uterine contractions by activating endometrial PLA2G6. Furthermore, gestation age-related sensitivity to PCB is associated with an increase in the expression of a previously unidentified 50-kDa PLA2G6 in rat uterus.

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Secretory Type II PLA2Immunoreactivity and PLA2Enzymatic Activity in Human Gestational Tissues Before, During and After Spontaneous-onset Labour at Term

Cited by 14 publications

References 0 publications

Regulation of Cyclooxygenase-2 Expression by Phospholipase D in Human Amnion-Derived WISH Cells

Regulation of Cyclooxygenase-2 Expression by Phospholipase D in Human Amnion-Derived WISH Cells

Regulation of sPLA2-IID in Human Decidua: Insights Into the Complexity of the Prostaglandin Pathway in Labor

Gestation Age-Related Increase in 50-kDa Rat Uterine Calcium-Independent Phospholipase A2 Expression Influences Uterine Sensitivity to Polychlorinated Biphenyl Stimulation1

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