Novel pathways regulating calcium mediated contractility in the pregnant uterus

在怀孕期间，子宫肌层必须首先保持静止，以允许胎儿生长，然后成为 被激活，以强大的收缩和驱逐成熟的胎儿独立的生活。不完全的理解 在调节肌层静止和激活之间的转换的机制中， 缺乏预防早产的有效战略，早产是导致儿童死亡的唯一最大原因 在全球范围内还不到5岁。我们最近发现了瞬时受体电位香草素4 通道(TRPV4)作为子宫肌层收缩的调节器。我们证明了钙，最关键的 子宫肌层收缩能力的决定因素，可通过TRPV4途径进入子宫肌层平滑肌细胞(MSMC) 这与L式的钙通道完全不同。有了一个协调的多学科团队，这项提案 是否会从机械上探索激活TRPV4促进子宫肌层收缩的假说 和炎症，是治疗早产的新的潜在靶点。关于TRPV4 AS的离散焦点 一种治疗早产的新治疗靶点具有很高的创新性和重大意义，正如所提议的 研究将提供基本的概念验证和机械数据，以允许开发定向治疗 针对TRPV4，这是一个以前没有在早产背景下解决的目标。我们最近证明了TRPV4 妊娠期动态调节TRPV4促进子宫肌层的表达和定位 在两种不同的早产小鼠模型中，阻断TRPV4可延长妊娠。新的 初步数据支持这样的假设，即TRPV4也促进子宫肌层炎症，这是一个关键的起始事件 在早产中。因此，靶向TRPV4可以同时抑制子宫肌层收缩和 炎症，一种可能比针对单个过程更有效的策略，从而代表了 创新和前所未有的战略。在一系列互补的目标中，我们将使用 分子、细胞、动物和人类研究的结合。我们首先计划确定 利用野生型基因调控TRPV4在子宫肌层静止和激活过程中的表达和活性 相关基因敲除小鼠探索TRPV4结合伙伴、激活、细胞转运和微观调控 RNA。其次，使用分子、细胞和小鼠早产模型，我们将检验这一假设 TRPV4增强子宫肌层炎症。第三个目标是展示我们之间的忠诚 在小鼠模型和人类怀孕中的发现。对人体的研究将提供基本的证据 妊娠期和月经初期TRPV4通道调节和激活的概念和机制 劳力。这些研究的完成将确立TRPV4在调节子宫肌层之间的转换中的作用 静止和激活，并提供特定于细胞和上下文的数据，这些数据可以转化为 选择性靶向子宫肌层中的TRPV4。总而言之，这些数据将使TRPV4通道成为一个可行的、 合理和新颖的目标，以解决早产，这是全球婴儿发病率和死亡率的主要原因。

During pregnancy, the myometrium must first remain quiescent to permit fetal growth, and then become activated to powerfully contract and expel the mature fetus for independent life. An incomplete understanding of the mechanisms that regulate the switch between myometrial quiescence and activation is highlighted by the absence of effective strategies to prevent preterm delivery, the single greatest cause of mortality in children less than 5 years of age across the globe. We recently identified the transient receptor potential vanilloid 4 channel (TRPV4) as a modulator of myometrial contractility. We showed that calcium, the most critical determinate of myometrial contractility, can enter myometrial smooth muscle cells (mSMC) via TRPV4, a route that is entirely distinct from L-type calcium channels. With a coordinated, multidisciplinary team, this proposal will mechanistically explore the hypothesis that activation of TRPV4 promotes myometrial contractility and inflammation, and is a new potential target to treat preterm labor. The discrete focus upon TRPV4 as a novel therapeutic target for the treatment of preterm labor is highly innovative and significant, as the proposed studies will provide essential proof-of-concept and mechanistic data to permit the development of therapies directed against TRPV4, a target not previously addressed in the context of preterm labor. We recently showed that TRPV4 expression and localization is dynamically regulated during pregnancy, that TRPV4 promotes myometrial contractility, and that blocking TRPV4 prolongs pregnancy in two distinct murine models of preterm labor. New preliminary data support the hypothesis that TRPV4 also promotes myometrial inflammation, a key initiating event in preterm labor. Thus, targeting TRPV4 may simultaneously suppress both myometrial contractility and inflammation, a strategy likely to be more efficacious than targeting a single process, thereby representing an innovative and unprecedented strategy. In a series of complementary aims, we will test our hypothesis using a combination of molecular, cellular, animal, and human studies. We first plan to identify the mechanisms that regulate TRPV4 expression and activity during myometrial quiescence and activation using wild type and relevant knock-out mice to explore TRPV4 binding partners, activation, cell trafficking, and regulation by micro RNAs. Second, using molecular, cellular, and murine models of preterm labor, we will test the hypothesis that TRPV4 enhances myometrial inflammation. The third aim is designed to demonstrate fidelity between our findings in murine models and human pregnancy. Studies in human subjects will provide essential proof of concept and mechanistic insight into TRPV4 channel regulation and activation during pregnancy and at the onset of labor. The completion of these studies will establish a role for TRPV4 in regulating the switch between myometrial quiescence and activation, and provide cell- and context-specific data that can be translated into therapies that selectively target TRPV4 in the myometrium. Together, these data will establish the TRPV4 channel as a viable, rational and novel target to address preterm labor, the major cause of infant morbidity and mortality worldwide.