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: 7661141
• 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 2011-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7661141
• 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（由申请人提供）：在包括人类在内的大多数物种中，怀孕期间的血浆水平17beta-雌二醇和孕酮增加。伴随妊娠晚期的雌性类固醇激素的升高与肌层平滑肌的电重塑有关。这些观察结果表明，雌性类固醇激素可以影响子宫平滑肌兴奋性涉及的离子电导的活性和/或表达。尽管据报道，递送机制与女性激素水平的降低有关，但劳动收缩的机制尚未根据离子通道表达清楚地研究。在怀孕期间，肌层的质量急剧增加，宫内压力的增加最小。为此，在怀孕期间必须放松子宫肌的平滑肌。因此，质膜拉伸激活的K+电导可能会贡献子宫中肌源性反应的重要组成部分。几个K+通道参与了子宫肌层中静止膜电位的调节和作用电位的重极化。最近，据报道，唯一的K+通道包括四个跨膜段和两孔域（K2P）。在K2P通道中，Trek-1，Trek-2和Traak具有独特的功能特性，并代表了第一个克隆的拉伸激活的K+通道。先前的研究表明，雌性类固醇激素会影响许多K+通道的转录表达。我们将在此提案中解决以下特定目的：AIM 1，我们将使用贴片钳方法识别鼠肌层中的SDK通道功能表达，并通过一氧化氮及其细胞内信号传导机制来表征这些通道的调节。 AIM 2，我们将使用常规的微电极记录，等轴测力测量和Ca2+成像分析来表征依赖拉伸性超极化和完整子宫内弛豫的弛豫。 AIM 3，我们将使用分子和蛋白质技术来研究与天然SDK通道有关的鼠肌层中的TREK-1表达。 AIM 4，我们将表征非妊娠，怀孕，产后和卵巢切除鼠模型中TREK-1表达的变化，以了解不同水平的女性激素下天然SDK通道的功能表达。特别是，这项研究将扩大TREK-1通道的雌激素调节的分子机制，从而导致肌层依从性的不同水平。了解这种机制可以允许在调节劳动和分娩的调节中进行临床干预，从而减少早产和随后的疾病的数量。公共卫生相关性：在过去的20年中，早产率增长了30％以上。在所有早产案例中，大约有40％的早产原因是未知的。该提案中概述的实验旨在评估伴随女性类固醇激素水平的急性和慢性变化的子宫TREK-1通道的变化，以研究与妊娠和递送机制的潜在功能关系。