PI/PLC FUNCTION IN PREGNANT RAT MYOMETRIUM

初步供资期间的研究表明， 磷脂酰肌醇信号通路（PSP）的激活导致 在胞浆钙振荡（CCO）驱动的阶段性子宫肌层中， 宫缩 重复的胞质钙瞬变产生 通过释放储存的细胞内钙，沿着内流 细胞外钙的浓度。其他研究表明， 参与PSP的信号转导蛋白的几种同种型 在大鼠子宫肌层组织中表达，包括五种亚型， 磷脂酶C（PLC）。 同时性的生理意义 这些多种PLC亚型在子宫肌层组织中的表达尚不清楚。 然而，似乎不同的亚型 是通过不同的膜受体介导PSP激活所必需的 类别（即G蛋白偶联对酪氨酸激酶偶联）。 的 本修订版竞争法中提出的研究的总体目标 继续申请是为了检验一个（或两个） 在子宫肌层中表达的PLC-γ同种型是 响应酪氨酸激活剂的阶段性收缩的产生 激酶（TK），包括凝血酶和血小板活化因子（PAF）。 具体目的是检验以下假设：1） 过钒酸盐（一种酪氨酸磷酸酶抑制剂）产生增加的PLC- γ磷酸化，肌醇磷酸（IP）的生产， CCO的产生和阶段性子宫肌收缩，2） 凝血酶引起的子宫肌层收缩由TK介导 激活，增加PLC-γ磷酸化，IP产生，以及 产生CCO，3）PAF产生阶段性子宫肌层收缩 由TK活化介导，PLC-γ磷酸化增加，IP 生产和CCO的产生，以及4）其中一个（或两个） PLC-γ异构体对于过钒酸盐、凝血酶和PAF是必需的 刺激PSP的活化和胞浆钙的产生 临时工 后一项研究将使用反义核酸进行。 用于原发性子宫内膜癌的PLC-γ 1和PLC-γ 2的寡核苷酸 肌细胞培养 这些拟议的研究将继续改善我们的 了解子宫肌层的分子机制 收缩，并最终提高我们的能力， 治疗临床上重要的子宫收缩活动障碍， 尤其是早产，这对 美国早产率过高

Studies during the initial funding period have demonstrated that activation of the phosphatidylinositol signaling pathway (PSP) results in cytosolic calcium oscillation (CCO) driven phasic myometrial contractions. The repetitive cytosolic calcium transients are produced by the release of stored intracellular calcium, along with the influx of extracellular calcium. Additional studies have demonstrated that several isoforms of the signal transduction proteins involved in the PSP are expressed in rat myometrial tissue, including five isoforms for phospholipase C (PLC). The physiologic significance of the simultaneous expression of these multiple PLC isoforms in myometrial tissue is yet to be completely defined; however, it appears that different isoforms are necessary to mediate PSP activation via different membrane receptor classes (i.e. G-protein coupled v. tyrosine kinase coupled). The overall goal of the studies being proposed in this revised Competing Continuation Application is to test the hypothesis that one (or both) of the PLC-gamma isoforms expressed in myometrium are required for the generation of phasic contractions in response to activators of tyrosine kinase (TK), including thrombin and platelet activating factor (PAF). The specific aims are to test the following hypotheses: 1) that pervanadate (a tyrosine phosphatase inhibitor) produces increased PLC- gamma phosphorylation, inositol phosphate (IP) production, the generation of CCOs, and phasic myometrial contractions, 2) that myometrial contractions in response to thrombin are mediated by TK activation, increased PLC-gamma phosphorylation, IP production, and the generation of CCOs, 3) that PAF produces phasic myometrial contractions mediated by TK activation, increased PLC-gamma phosphorylation, IP production, and the generation of CCOs and 4) that one (or both) of the PLC-gamma isoforms are essential for the pervanadate, thrombin and PAF stimulated activation of the PSP and the generation of cytosolic calcium transients. The latter studies will be performed utilizing antisense oligonucleotides for PLC-gamma1 and PLC-gamma2 with primary uterine myocytes cultures. These proposed studies will continue to improve our understanding of the molecular mechanisms underlying myometrial contractions, and ultimately improve our ability to more effectively treat clinically important disturbances of uterine contractile activity, especially premature labor which contributes substantially to the excessive preterm delivery rate in the U.S.