A novel molecular mechanism for stimulating uterine contractility by oxytocin

催产素刺激子宫收缩的新分子机制

• 批准号: 10703507
• 负责人: Sarah K. England
• 金额: $ 51.74万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-04-01 至 2027-08-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10703507
• 关键词: Address; Calcium; Calcium Channel; Cell Separation; Cells; Charge; Clustered Regularly Interspaced Short Palindromic Repeats; Complex; Data; Dyes; Fetus; Flow Cytometry; Frequencies; Funding; Future; Goals; Human; Image; In Vitro; Ion Channel; Knowledge; Measures; Membrane; Membrane Potentials; Molecular; Mus; Myometrial; Oxytocin; Pathway interactions; Potassium; Potassium Channel; Pregnancy; Premature Labor; Proteins; Proteomics; Public Health; Publishing; Regulation; Relaxation; Reporting; Reproductive Health; Role; Signal Transduction; Smooth Muscle; Smooth Muscle Myocytes; Sodium; Testing; Therapeutic; Time; Uterus; Work; conditional knockout; human tissue; improved; in vivo; knock-down; mRNA Expression; member; myometrium; novel; patch clamp; prevent; protein expression; uterine contractility; voltage sensitive dye

Project Summary During pregnancy, the uterus gradually transitions from a quiescent state characterized by weak, asynchronous, regional contractions to an activated state in which contractions increase in force, frequency, and synchrony to expel the fetus at term. A major driver of this transition is gradual depolarization of the myometrial smooth muscle cell (MSMC) membrane potential. As the inside of the membrane becomes less negatively charged, the myometrium becomes more excitable. However, the molecular pathways controlling this transition are unknown, hampering our ability to develop strategies to regulate uterine contractility to prevent pre- or post-term labor. Here, we propose to test the central hypothesis that a sodium (Na+) signaling complex formed by the Na+- activated potassium (K+) channel SLO2.1 and the Na+ leak channel NALCN regulates this transition. This hypothesis is founded on published and preliminary data we obtained with funding from our previous R01. In primary human MSMCs isolated at term, we showed that Na+ entry through NALCN activated K+ efflux through SLO2.1 and hyperpolarized the membrane. Next, we showed that activation of this complex reduced tension in uterine strips. Finally, we reported that inhibiting this complex induced MSMC depolarization, triggering calcium (Ca2+) entry through voltage-dependent Ca2+ channels and promoting contractility. Together, these data indicate that the NALCN/SLO2.1 complex is a strong candidate to control the MSMC membrane potential. However, because we used human tissues, we could not determine the role of this complex in the gradual depolarization of the MSMC membrane potential over pregnancy. To address this limitation and fully test our hypothesis, our objective is to define the function and regulation of the NALCN/SLO2.1 complex across pregnancy in mouse MSMCs. The goals of this project are to: 1) Define NALCN/SLO2.1 complex activity across pregnancy, 2) Assess the effects of NALCN/SLO2.1 complex activity on intracellular Ca2+ and uterine contractility and 3) Identify additional members of the NALCN/SLO2.1 complex in MSMCs and determine their effects on functionality of the complex. In completing these aims, we will define the main regulators of MSMC membrane potential and how they change as pregnancy progresses. This work will facilitate future efforts aimed at developing therapeutics to inhibit the NALCN/SLO2.1 complex to promote labor or to activate the complex to promote quiescence and prevent preterm labor.

项目摘要 在怀孕期间，子宫逐渐从静态状态逐渐过渡，其特征是弱，异步， 区域收缩到激活状态，在该状态下，宫缩的力，频率和同步增加到 在学期开除胎儿。这种过渡的主要驱动力是肌层平滑肌的逐渐去极化 细胞（MSMC）膜电位。随着膜的内部变得不那么负电动， 肌层变得更加兴奋。但是，控制此转变的分子途径是未知的， 阻碍我们制定策略来规范子宫收缩力以防止前或后劳动的能力。 在这里，我们建议测试中心假设，即由Na+ - 形成的钠（Na+）信号传导复合物 活化的钾（K+）通道Slo2.1和Na+泄漏通道NALCN调节了这一转变。这 假设建立在我们从以前的R01资金中获得的已发表和初步数据。在 在学期分离的主要人类MSMC，我们表明Na+通过NALCN激活了K+外排 Slo2.1并超极化膜。接下来，我们表明这种复合物的激活减少了张力 子宫条。最后，我们报告说，抑制这种复合物诱导的MSMC去极化，触发钙 （CA2+）通过电压依赖的Ca2+通道和促进收缩性进入。这些数据一起表示 NALCN/SLO2.1复合物是控制MSMC膜电位的有力候选者。然而， 因为我们使用了人体组织，所以我们无法确定该复合物在逐渐去极化中的作用 MSMC膜在怀孕期间的潜力。为了解决这一限制并充分检验我们的假设，我们 目的是定义小鼠整个怀孕期间NALCN/SLO2.1复合物的功能和调节 MSMCS。该项目的目标是：1）定义NALCN/SLO2.1整个怀孕的复杂活动，2）评估 NALCN/SLO2.1复合活性对细胞内Ca2+和子宫收缩力的影响，3） MSMC中NALCN/SLO2.1复合物的其他成员，并确定其对功能的影响 复杂的。在完成这些目标时，我们将定义MSMC膜潜力的主要调节剂以及如何 随着怀孕的进展，它们会发生变化。这项工作将促进旨在开发治疗剂的未来努力 抑制NALCN/SLO2.1复合物以促进劳动或激活配合物以促进静止和 防止早产。

项目成果

Na+-Leak Channel, Non-Selective (NALCN) Regulates Myometrial Excitability and Facilitates Successful Parturition.

• DOI: 10.1159/000491805
• 发表时间: 2018
• 期刊: Cellular physiology and biochemistry : international journal of experimental cellular physiology, biochemistry, and pharmacology

SLO2.1/NALCN a sodium signaling complex that regulates uterine activity.

• DOI: 10.1016/j.isci.2021.103210
• 发表时间: 2021-11-19
• 期刊: iScience
• 影响因子: 5.8
• 作者: Ferreira JJ;Amazu C;Puga-Molina LC;Ma X;England SK;Santi CM
• 通讯作者: Santi CM