The elucidation of the mechanism of abortion/ premature birth by the key enzymes (PLA2 and COX) in the arachidonic acid cascade

我把注意力集中在磷脂酶A2(PLA2)上，它被认为是与子宫收缩和炎症反应相关的关键酶。作者研制了一种高灵敏度的高速层析酶活性测定系统，并测定了一例临床早产患者血清、羊水和羊膜中磷脂酶A2的活性。此外，我还用该酶的特异性单抗(Shionogi Pharmtics Gift)用放射免疫法测定了该酶免疫反应阳性的PLA2的浓度。结果表明，1例早产患者血清和羊水中有大量的PLA2分泌，II组PLA2主要由早产患者的羊水细胞分泌。免疫反应阳性的第II组PLA2在血清和羊膜中的浓度与酶活性相关，并建立了检测体系。由于该测量系统被证明具有非常高的**灵敏度…与高效液相色谱法比较，作为早产的生物传感器，这种酶活性测量结果比其他炎症蛋白更优越。此外，我还发现了一例无临床炎症的早产患者的PLA2表现。提示炎症相似或花生四烯酸级联酶群异常参与了早产的发病机制，在考虑胎盘感染和早产机制时，有必要考虑引导花生四烯酸代谢(磷脂酶和环氧合酶)的氧化应激的影响。HNE(4-羟基-2-壬烯醛)是一种具有代表性的脂质过氧化降解产物。含有HNE的烷基修饰蛋白因其难于消化而容易在组织中蓄积，可能是氧化应激的良好标志。我发现HNE在临床炎症性疾病的胎盘组织中有较强的表达，RY-PCR检测到HNE阳性的绒毛组织中也有COX-2的表达。我还证明了在绒毛组织培养上清液中加入HNE后，前列腺素E_2明显升高。较少

I have focused attention to phospholipase A2 (PLA2) which has been thought to be the key enzyme associated uterine contractions and an inflammatory reaction. I developed high sensitive an enzyme activity measurement system with high-speed chromatography and measured the activity of PLA2 in serum, amniotic fluid and amniotic membrane of a clinical premature labor patient. In addition, I measured the concentration of immunoreactive PLA2 with RIA method by a specific monoclonal antibody of this enzyme (gift from Shionogi Pharmaceutical). As a result, a large quantity of PLA2 was secreted in serum and amniotic fluid of a premature labor patient and group II PLA2 principally was proved to be secreted from amniotic cells of a premature labor patient in large quantities. The concentration of the immunoreactive group II PLA2 in serum and amnion related to the enzymatic activity and the system of measurement was able to be established. Since this measurement system proved very high **ensitivity … More with HPLC, this enzyme activity measurement corollary was more superior than other inflammatory protein as a biosensor of premature labor. Furthermore, I identified manifestation of PLA2 to a premature labor patient without clinical inflammation. This result suggests that inflammation resemblance or abnormality of enzyme groups of the arachidonic acid cascade participates in onset mechanism of premature labor.It is necessary to consider influence of the oxidation stress which guides arachidonic acid metabolism (phospholipase and cyclooxygenase) when thinking about placental infection and mechanism of premature labor. HNE (4-hydroxy-2-nonenal) is a representative lipid peroxide degradation product. Alkyl modified protein with HNE is easy to be accumulated in the tissue because of its difficulty of digestion and it might be a good marker of oxidative stress. I demonstrated that HNE is strongly expressed in the placenta with clinical inflammatory diseases and manifestation of Cox-2 mRNA in the chorionic villi was observed in addition with HNE by RY-PCR. I also demonstrated that prostaglandine E2 was clearly elevated in the culture media of chorionic tissue by the addition of HNE. Less