Thrombin-Stimulated Intrauterine Signaling Pathway

描述（由申请人提供）：在美国，早产使8-10%的妊娠复杂化，导致显著的新生儿和儿科发病率，并造成约75%的新生儿死亡。早产发生的潜在机制尚不清楚;然而，迄今为止的研究表明，早产通常与生殖道感染相关，如升高的促炎细胞因子（例如IL 2、ILa、TNF-α和IFN-γ）所示。尽管已经表明这些细胞因子导致子宫内组织产生的前列腺素增加，但尚不清楚这是否是这些促炎细胞因子导致刺激早产收缩的唯一机制。在该RO 1申请中描述的研究将检验假设：内毒素（LPS）刺激增加的促炎细胞因子，特别是IL-2、TNF-α和IFN-γ，导致“凝血酶刺激的子宫内信号传导途径”的激活;即增强型磷脂乱序酶（PLS），组织凝血酶原酶（Fg 12），凝血酶原和凝血酶受体（PAR 1）的表达和活化导致早产收缩和分娩。我们的初步研究已经证实了该途径的所有组成部分在近期大鼠子宫内的分子表达。使用LPS诱导的定时妊娠大鼠早产模型，我们将完成以下具体目标：1）确定早产大鼠子宫中Fgl 2表达和活化是否增加，导致凝血酶原酶活性，2）确定早产大鼠子宫中磷脂乱序酶表达和功能活性是否增加，导致Fgl 2活性增强，4）确定子宫PAR-1表达和活化是否增加，从而导致子宫肌层收缩、蜕膜坏死和子宫内出血，和5）检验上述现象平行发生并在导致大鼠LPS刺激的早产和分娩的事件中有助于胡枝子素的作用的假设。这些研究有望显著提高我们对宫内感染引起早产的机制的理解。

DESCRIPTION (provided by applicant): Preterm delivery, which complicates 8-10% of pregnancies in the United States, results in significant neonatal and pediatric morbidity, and is responsible for about 75% of the neonatal mortality. The mechanisms underlying the onset of preterm labor are unclear; however, studies to date suggest that preterm delivery is often associated with genital tract infection, as suggested by elevated proinflammatory cytokines (e.g. IL2, ILa, TNF-a, and IFN-g). Although it has been shown that these cytokines lead to increased prostaglandin production by intrauterine tissues, it is unclear whether this is the only mechanism by which these pro-inflammatory cytokines lead to the stimulation of preterm contractions. The research described in this RO1 application will test the hypothesis: endotoxin (LPS) stimulates increased proinflammatory cytokines, especially IL-2, TNF-a and IFN-g resulting in activation of the "thrombin stimulated intrauterine signaling pathway"; i.e. enhanced phospholipid scramblase (PLS), tissue prothrombinase (Fgl2), prothrombin and thrombin receptor (PAR1) expression and activation leading to preterm contractions and delivery. Our preliminary studies have confirmed the molecular expression of all of the components of this pathway within the near term rat uterus. Using the LPS-induced preterm delivery model in the timed-pregnant rat, we will complete the following specific aims: 1) determine if Fgl2 expression and activation are increased in the preterm rat uterus, leading to prothrombinase activity, 2) determine if phospholipid scramblase expression and functional activity increase in the preterm rat uterus, leading to enhanced Fgl2 activity, 3) determine if increased intrauterine prothrombin expression occurs, leading to enhanced thrombin generation, 4) determine if uterine PAR-1 expression and activation are increased, leading to myometrial contractions, decidual necrosis, and intrauterine bleeding, and 5) test the hypothesis that the above phenomena occur in parallel and contribute to the role of prostaglandins during the events leading to LPS-stimulated preterm labor and delivery in the rat. These studies are anticipated to significantly improve our understanding of the mechanisms underlying preterm labor in the presence of intrauterine infection.