Functional and molecular identification of TREK-1 channel in myometrium in relati

子宫肌层TREK-1通道的功能及分子鉴定

• 批准号: 7843550
• 负责人: SANG Don KOH
• 金额: $ 17.56万
• 依托单位: UNIVERSITY OF NEVADA RENO
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-05-15 至 2012-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7843550
• 关键词: Action Potentials; Acute; Address; Cell membrane; Cells; Chronic; Clinical; Data; Disease; Estradiol; Estrogens; Family; Female; Hormones; Human; Image Analysis; Intervention; Investigation; Ion Channel; Isometric Exercise; Link; Measurement; Mediating; Membrane; Membrane Potentials; Methods; Microelectrodes; Modeling; Molecular; Monitor; Mus; Muscle Cells; Myometrial; Nitric Oxide; Plasma; Postpartum Period; Potassium Channel; Pregnancy; Premature Birth; Premature Labor; Progesterone; Property; Proteins; Regulation; Relaxation; Reporting; Rest; Role; Signal Transduction; Smooth Muscle; Staging; Stretching; Swelling; TRAAK channel; Techniques; Uterine Smooth Muscle Excitability; Uterus; design; insight; member; myometrium; novel; patch clamp; potassium channel protein TREK-1; pregnant; pressure; public health relevance; research study; response; shear stress; steroid hormone; therapeutic development; uterine smooth muscle cell

DESCRIPTION (provided by applicant): In most species, including humans, plasma levels of 17beta-estradiol and progesterone increase during pregnancy. The elevation of female steroid hormones that accompanies the late stages of pregnancy has been linked to electrical remodeling of myometrial smooth muscle. These observations suggest that female steroid hormones can influence the activity and/or expression of ionic conductances involved in uterine smooth muscle excitability. Although it has been reported that the delivery mechanism is related to a decrease in female hormone levels, the mechanism of labor contraction has not been clearly studied in terms of ion channel expression. During pregnancy, the mass of myometrium increases dramatically, with only minimal increases in intrauterine pressure. To accomplish this, the smooth muscle of the myometrium must remain relaxed during pregnancy. Therefore, K+ conductances activated by stretch of the plasma membrane may contribute an important component of the myogenic response in the uterus. Several K+ channels participate in the regulation of resting membrane potential and repolarization of action potentials in the myometrium. Recently unique K+ channels have been reported that consist of four transmembrane segments and two-pore domains (K2P). Among K2P channels, TREK-1, TREK-2 and TRAAK have unique functional properties and represent the first cloned stretch-activated K+ channels. Previous studies suggest that female steroid hormones influence the transcriptional expression of a number of K+ channels. We will address the following specific aims in this proposal: Aim 1, we will identify SDK channel functional expression in the murine myometrium using patch-clamp methods and will characterize the regulation of these channels by nitric oxide and its intracellular signaling mechanisms. Aim 2, we will characterize stretch-dependent hyperpolarization and relaxation in intact myometrium using conventional microelectrode recordings, isometric force measurements and Ca2+ imaging analysis. Aim 3, we will use molecular and protein techniques to investigate TREK-1 expression in murine myometrium in relation to native SDK channels. Aim 4, we will characterize changes in TREK-1 expression in non-pregnant, pregnant, postpartum and ovariectomized murine models to understand the functional expression of native SDK channels under various levels of female hormones. In particular this investigation will expand the molecular mechanism of estrogen regulation of TREK-1 channels that leads to the different levels of myometrial compliance. Understanding this mechanism may allow for clinical intervention in the modulation of labor and delivery, reducing the number of premature births and subsequent disorders. PUBLIC HEALTH RELEVANCE: The rate of premature birth has grown by more than 30 percent in the last 20 years. In about 40 percent of all cases of preterm birth, the causes of preterm labor are unknown. Experiments outlined in this proposal are designed to evaluate changes in uterine TREK-1 channels that accompany acute and chronic changes in female steroid hormone levels to study a potential functional relationship with pregnancy and delivery mechanisms.

描述（由申请方提供）：在大多数物种中，包括人类，17 β-雌二醇和孕酮的血浆水平在妊娠期间增加。妊娠晚期女性类固醇激素水平的升高与子宫肌层平滑肌的电重构有关。这些观察结果表明，女性类固醇激素可以影响子宫平滑肌兴奋性所涉及的离子电导的活性和/或表达。尽管有报道称分娩机制与女性激素水平的降低有关，但就离子通道表达而言，尚未明确研究分娩收缩的机制。怀孕期间，子宫肌层质量急剧增加，宫内压仅略有增加。为了实现这一点，子宫肌层的平滑肌在怀孕期间必须保持松弛。因此，由质膜拉伸激活的K+电导可能是子宫肌源性反应的重要组成部分。几种K+通道参与调节静息膜电位和子宫肌层动作电位的复极化。最近报道了由四个跨膜段和两个孔结构域（K2 P）组成的独特的K+通道。在K2 P通道中，TREK-1、TREK-2和TRAAK具有独特的功能特性，代表了第一个克隆的牵张激活的K+通道。以往的研究表明，女性类固醇激素影响的转录表达的K+通道的数量。我们将解决以下具体目标，在这个建议：目的1，我们将确定SDK通道的功能性表达在小鼠子宫肌层使用膜片钳方法，并将这些通道的一氧化氮和其细胞内信号转导机制的调节的特点。目的2，我们将使用传统的微电极记录，等长力测量和Ca 2+成像分析来表征完整子宫肌层的牵张依赖性超极化和松弛。目的3，我们将利用分子和蛋白质技术研究TREK-1在小鼠子宫肌层中的表达与天然SDK通道的关系。目的4，我们将表征TREK-1在非妊娠、妊娠、产后和卵巢切除小鼠模型中的表达变化，以了解天然SDK通道在不同水平的雌性激素下的功能表达。特别是这项研究将扩大雌激素调节TREK-1通道的分子机制，导致不同水平的子宫肌层的顺应性。了解这一机制可能有助于临床干预分娩和分娩的调节，减少早产和后续疾病的数量。公共卫生相关性：在过去20年中，早产率增长了30%以上。在大约40%的早产病例中，早产的原因是未知的。本提案中概述的实验旨在评估伴随女性类固醇激素水平急性和慢性变化的子宫TREK-1通道的变化，以研究与妊娠和分娩机制的潜在功能关系。