SIGNALING AND UTERINE CONTRACTILITY DURING PREGNANCY

描述(由申请人提供)：早产发生在高达10%的新生儿，占新生儿死亡的75%。对正常妊娠期间收缩静止的机制有更多的了解是非常必要的。这项建议的总体目标是检验这一假说，即在正常和异常妊娠和分娩期间，基础细(肌动蛋白)和粗(肌球蛋白)细丝调节机制会长期改变。其具体目的是：(1)研究Caldesmon(CAD)肌动蛋白结合蛋白(Caldesmon，CAD)蛋白水平或磷酸化水平的变化对妊娠依赖性收缩的影响的假说：(2)在大鼠和人类的妊娠和分娩过程中，细胞外调节蛋白(ERK1/2)信号的变化有助于改变：(A)CAD活性；和/或(B)子宫肌层的收缩；(3)研究肌球蛋白磷酸酶调节参与大鼠和人妊娠依赖性收缩能力改变的假说；(4)研究导致妊娠依赖性收缩改变的信号转导的协调至少部分是由支架蛋白小窝蛋白的作用所介导的假说。由于人体组织供应有限，将使用一个定时的大鼠模型来详细绘制信号通路图，并计划进行体内药物研究。然而，人类样本将被并行收集，并将在更长的时间基础上用于测试在大鼠组织中获得的关键结果。将使用多学科方法，结合收缩功能评估、生化测量、定量共聚焦显微镜、器官培养、反义实验和体内药物治疗来验证上述假设。人们希望，如果能够识别和定义新的机制，所涉及的途径将代表早产和功能障碍病例治疗干预的新的潜在靶点。

DESCRIPTION (provided by applicant): Preterm delivery occurs in up to 10% of births and accounts for 75% of neonatal deaths. A greater understanding of the mechanisms of contractile quiescence during normal pregnancy is sorely needed. The general aim of this proposal is to test the hypothesis that basal thin (actin) and thick (myosin) filament regulatory mechanisms are chronically altered during normal and abnormal pregnancy and labor. The specific aims are: (1) To investigate the hypothesis that changes in either the protein levels or phosphorylation levels of the actin binding protein, Caldesmon (CaD) contribute to gestation dependent contractility changes in both a timed pregnant rat model and in human tissue samples; (2) To investigate the hypothesis that changes in Extracellular Regulated Kinase (ERK1/2) signaling contribute to changes: (a) in CaD activity; and/or (b) in the contractility of myometrium during pregnancy and labor in the rat and human; (3) To investigate the hypothesis that regulation of Myosin Phosphatase is involved in gestation-dependent changes in contractility in the rat and human; and (4) To investigate the hypothesis that coordination of signal transduction that leads to gestation-dependent changes in contractility is, at least in part, mediated by the action of the scaffolding protein, caveolin. Because of the limited supply of human tissue, a timed rat model will be used for the detailed mapping of signaling pathways and the planned in vivo drug studies. However, human samples will be collected in parallel and, on a longer time base, will be used to test critical results obtained with the rat tissue. A multidisciplinary approach will be used, combining functional assessment of contractility, biochemical measurements, quantitative confocal microscopy, organ culture, antisense experiments, and in vivo drug treatment to test the above hypotheses. It is hoped that if novel mechanisms can be identified and defined, the pathways involved will represent new potential targets for therapeutic intervention in cases of preterm and dysfunctional labor.