Evaluating the role of human cervical smooth muscle cells in normal and premature cervical remodeling

摘要： 自发性早产（sPTB）仍然是一个重大的产科困境，给美国带来了巨大的成本。 健康护理sPTB的病因各不相同，但最终共同途径涉及过早的宫颈重塑 (PCR)缩短和扩张。尽管这一健康问题的重要性，正常和 人类的PCR还不太清楚。例如，子宫颈平滑肌细胞（CSMCs）在 宫颈重塑仍不清楚。在过去的五年里，在我杰出的指导下， 导师们，我从事了宫颈重塑的研究，并帮助建立了协作宫颈研究中心。 研究小组（CCRG）在哥伦比亚大学。CCRG的目标是解决以下复杂问题： PCR从真正的多学科方法。我最初的工作确定了内部操作系统的CSMC是 环周定向的（类似于“括约肌”）和来自内口的宫颈组织响应收缩 催产素。我建议，CSMCs可能有两个关键功能：收缩和/或ECM重塑。作为 随着怀孕的增长，来自胎儿的压力会对子宫颈产生拉伸作用。我假设CSMC 牵拉诱导收缩（以维持括约肌张力）和/或ECM重塑。此外，我假设， 患有PCR的妇女表现出异常的宫颈拉伸反应、收缩力和/或ECM重塑。在 目的1，我将拉伸妊娠宫颈组织活检和CSMCs从妇女（研究组）和没有 PCR（对照，CTL）以确定1）拉伸是否诱导宫颈收缩，2）宫颈和CSMC是否来自 患有PCR的女性表现出异常的收缩力和3）潜在的收缩机制，这可能解释了 收缩性缺陷在目标2中，我将研究来自PCR女性的宫颈组织和CSMCs是否表现出 异常牵张反应导致MMP活化增加，胶原蛋白周转/ECM重塑 和2）如果炎症进一步增强这种牵张诱导的MMP活化/ECM 重塑在目标3中，我将评估在转录组中是否存在牵张诱导的分子表型变化 来自PCR与CTL女性的CSMC水平，特别关注收缩性和ECM重塑 途径。为了实现这个目标，我一直在收集有PCR病史的孕妇的组织， 使用IRB批准的方案从胎龄匹配的CTL中获得。如果患有PCR的女性有1）CSMC， 不能响应拉伸而收缩和维持“括约肌样”张力和/或2）表现出异常ECM 重塑对拉伸的反应，导致机械上较弱的宫颈，这可能解释了为什么宫颈 最终失败导致sPTB。在我的导师和CCRG团队的指导下，这个奖项将使我能够 扩大我的实验知识基础和调查技能，使我可以实现我的最终目标， 成为一个成功的和独立的临床科学家，其重点是防止PCR和PTB。

ABSTRACT: Spontaneous preterm birth (sPTB) remains a significant obstetric dilemma with enormous costs to U.S. healthcare. The etiology of sPTB varies, but the final common pathway involves premature cervical remodeling (PCR), shortening and dilation. Despite the importance of this health issue, the pathophysiology of normal and PCR in humans is not well understood. For instance, the role of cervical smooth muscle cells (CSMCs) in cervical remodeling remains unknown. Over the last five years, under the guidance of my outstanding mentors, I have engaged in studies of cervical remodeling and helped to establish the Collaborative Cervix Research Group (CCRG) at Columbia University. The goal of the CCRG is to tackle the complex problem of PCR from a truly multidisciplinary approach. My initial work established that CSMCs at the internal os are circumferentially oriented (similar to a “sphincter”) and cervical tissue from the internal os contracts in response to oxytocin. I propose that CSMCs may have two key functions: contraction and/or ECM remodeling. As pregnancy grows, the pressure from the growing fetus applies stretch to cervix. I hypothesize that CSMC stretch induces contraction (to maintain sphincter tone) and/or ECM remodeling. Further, I hypothesize that women with PCR exhibit abnormal cervical stretch responses, contractile force and/or ECM remodeling. In Aim 1, I will stretch pregnant cervical tissue biopsies and CSMCs from women with (study group) and without PCR (controls, CTL) to establish 1) if stretch induces cervical contractility, 2) if cervices and CSMCs from women with PCR exhibit aberrant contractility and 3) potential contractile mechanisms which may explain the contractility defect. In Aim 2, I will investigate if cervical tissue and CSMCs from women with PCR 1) exhibit abnormal stretch responses resulting in increased MMP activation, collagen turnover/ECM remodeling compared to CTLs and 2) if inflammation further enhances this stretch-induced MMP activation/ECM remodeling. In Aim 3, I will evaluate if stretch-induced molecular phenotypic changes exist at the transcriptome level in CSMC from women with PCR vs CTL with particular attention to contractility and ECM remodeling pathways. Toward this goal, I have been collecting tissue from pregnant women with a history of PCR and from gestational age-matched CTLs using IRB approved protocols. If women with PCR have 1) CSMCs that cannot contract and maintain “sphincter-like” tone in response to stretch and/or 2) exhibit abnormal ECM remodeling responses to stretch resulting in a mechanically weaker cervix, this may explain why the cervix ultimately fails leading to sPTB. With the guidance of my mentors and CCRG team, this award will allow me to expand my experimental knowledge base and investigational skills so I may achieve my ultimate goal of becoming a successful and independent clinician scientist whose focus is to prevent PCR and PTB.