Mechanisms by which the myometrial ECM modulates myometrial cell function

摘要 早产是婴儿死亡的主要原因，可能会给幸存者带来长期的健康挑战。 全球每年有1500万儿童早产。确定风险因素和 开发预防早产的治疗方法需要更好地理解分子 促使足月分娩的过程。在怀孕的过程中，子宫生长和重塑以 适应正在生长的胎儿，但在子宫收缩的足月前仍保持静止 表示成功交付的状态。胎儿、机械、激素和炎症信号共同调节 通过我们对分子细节的理解，子宫肌层静止和收缩之间的平衡 仍然不完整。年中啮齿动物细胞外基质(ECM)蛋白合成增加 妊娠支持细胞外基质在调节可能调节表型变化的机械信号中的作用 子宫肌层细胞。这项应用的重点是了解子宫肌层ECM的调节作用 妊娠期子宫肌层细胞表型和功能的结构。带着这个目标，我们将研究这个角色 以及赖氨酰氧化酶(LOX)的调节，这是一种针对ECM成分胶原和弹性的关键酶 纤维调节ECM的硬度和强度。我们提供的证据表明：1)LOX表达是 在小鼠子宫肌层合成期(妊娠12天和15天)的暂时性诱导 重塑；2)抑制妊娠中的LOX活性可防止分娩的开始和诱导 收缩相关基因，如连接蛋白43、催产素受体和前列腺素内过氧化产物 我们将确定LOX是否调节细胞外基质的结构变化和细胞外基质的功能变化。 肌层在重塑的合成阶段导致肌层强度增加。我们 还将调查LOX介导的组织僵硬增加是否提供了一种机械信号，即 将子宫肌层细胞从合成期的静止期转变为足月的收缩细胞所必需的。 这些研究将拓宽我们对机械信号的理解，机械信号调节着 子宫的静止和收缩，从而确定预防高血压的治疗靶点 子宫过早收缩和早产。此外，这些研究将整合各种不同的专业知识 申请人并提供成功所需的必要培训和职业发展 制定一个强有力的独立研究计划，解决一个重要而未被充分研究的领域 子宫生物学的研究。

ABSTRACT Preterm birth is a leading cause of infant mortality and can lead to long term health challenges in survivors. Fifteen million children are born prematurely worldwide on an annual basis. Identification of risk factors and development of preventative therapies against preterm birth require improved understanding of the molecular processes that drive parturition at term. Over the course of pregnancy the uterus grows and remodels to accommodate the growing fetus yet remains quiescent until term when the uterus transforms to a contractile state for successful delivery. Fetal, mechanical, hormonal and inflammatory signals collectively regulate the balance between myometrial quiescence and contractility though our understanding of the molecular details remains incomplete. Increased synthesis of extracellular matrix (ECM) proteins noted in rodents in mid- pregnancy support a role for ECM in regulating mechanical signals that may regulate phenotypic changes in the myometrial cell. The focus of this application is to understand the regulatory role of myometrial ECM structure on myometrial cell phenotype and function in pregnancy. With this goal in mind, we will study the role and regulation of lysyl oxidase (LOX), a key enzyme that targets the ECM components collagen and elastic fibers to regulate the stiffness and strength of the ECM. We provide evidence that 1) LOX expression is temporally induced in the mouse myometrium in the synthetic phase (gestation days12 and 15) of myometrial remodeling; 2) inhibition of LOX activity in pregnancy prevents onset of parturition and prevents the induction of contraction associated genes such as connexin 43, oxytocin receptor and prostaglandin endoperoxide synthase 2. We will determine if LOX regulates structural changes in the ECM and functional changes in the myometrium that result in increased strength of the myometrium during the synthetic phase of remodeling. We will also investigate whether LOX-mediated increases in tissue stiffness provides a mechanical signal that is required to transition myometrial cells from quiescence in the synthetic phase to a contractile cell at term. These studies will broaden our understanding of the mechanical signals that regulate the balance between uterine quiescence and contractility and thus lead to identification of therapeutic targets for prevention of premature uterine contractions and preterm birth. In addition these studies will integrate the varied expertise of the applicant and provide the requisite training and career development required for his successful development of a strong independent research program that will address an important and understudied area of uterine biology.