Regulation of Prostaglandin E Synthases in Parturition

描述（由申请人提供）：子宫内前列腺素（PG）在足月和早产分娩过程中起近端介质的作用。妊娠组织内子宫收缩性PG（特别是PGE 2）的产生主要通过涉及诱导酶环氧合酶-2（考克斯-2）的转录上调的途径发生。直到最近，从考克斯-2反应产物PGH 2产生末端前列腺素被认为是快速发生的，并且没有特别的控制。这种观点随着最近对具有PGH至POE异构酶活性的两种酶的表征而改变。已经发现，这些酶，微粒体前列腺素E合酶（PGES）和胞质PGES，在炎症条件下对PGE 2的产生的贡献不相等。在这个提议中，我们打算表征这两种PGES亚型与考克斯-2相关的表达模式。这将在模拟炎症条件下使用人羊膜衍生的WISH细胞和人羊膜的原代培养物进行。我们建议结合免疫细胞化学，在信使RNA水平和蛋白质水平（在全细胞裂解物和亚细胞组分中）表征微粒体和胞质PGES的表达模式。我们希望支持这一假设，即在其他系统中，微粒体PGES在子宫收缩的POE 2的产生中与考克斯-2功能相关。

DESCRIPTION (provided by applicant): Intrauterine prostaglandins (PGs) act proximal mediators in the process of parturition, both at term and preterm. The production of uterotonic PGs (particularly PGE2) within gestational tissues occurs primarily via a pathway involving transcriptional up-regulation of the inducible enzyme, cyclooxygenase-2 (COX-2). Until recently, the generation of terminal prostanoids from the COX-2 reaction product, PGH2, was thought to occur rapidly and under no particular control. This view has changed with the recent characterization of two enzymes possessing PGH to POE isomerase activity, It has been discovered that these enzymes, microsomal prostaglandin E synthase (PGES) and cytosolic PGES, contribute unequally to the generation of PGE2 under inflammatory conditions. In this proposal, we intend to characterize the expression patterns of these two PGES isoforms in relation to COX-2. This will be done using human amnion-derived WISH cells and primary cultures of human amnion, under simulated inflammatory conditions. We propose to characterize the expression patterns of microsomal and cytosolic PGES at the messenger RNA level and at the and at the protein level (in both whole cell lysates and subcellular fractions), combined with immunocytochemistry. We hope to support the hypothesis that, as in other systems, microsomal PGES is functionally linked to COX-2 in the generation of uterotonic POE2.