A novel mechanism for inflammation-induced preterm birth via PR-A phosphorylation

通过 PR-A 磷酸化炎症诱导早产的新机制

• 批准号: 10096304
• 负责人: Sam Antonio MESIANO
• 金额: $ 55.89万
• 依托单位: CASE WESTERN RESERVE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-04-01 至 2026-03-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10096304
• 关键词: Address; Affect; Anti-Inflammatory Agents; Antiinflammatory Effect; Binding; Biological Assay; Biological Models; Birth; Cell Line; Cells; Cesarean section; Complex; Data; Development; Discipline of obstetrics; Environment; Fetal Development; Freezing; Generations; Genes; Genetic Transcription; Goals; Gravid; Hormonal; Hormone Receptor; Human; Human Biology; IL8 gene; In Vitro; Induced Labor; Infection; Inflammation; Inflammatory; Interleukin-1 beta; Knowledge; Labor Onset; Lead; Link; Macaca mulatta; Maps; Mediating; Mitogen-Activated Protein Kinases; Modeling; Molecular; Mus; Myometrial; Neonatal Intensive Care Units; Neonatal Mortality; Nuclear; PTGS2 gene; Pathway interactions; Phase; Phosphorylation; Play; Pregnancy; Premature Birth; Premature Labor; Process; Progesterone; Progesterone Receptors; Protein Isoforms; Protein Kinase; Publishing; Reagent; Receptor Signaling; Regulation; Relaxation; Research; Response Elements; Risk; Role; Serine; Signal Pathway; Signal Transduction; Stimulus; Testing; Tissues; Transcription Factor AP-1; Uterus; Withdrawal; Woman; Work; base; clinically significant; effective therapy; experimental study; in vivo; innovation; intrauterine infection; mouse model; myometrium; neonatal morbidity; new therapeutic target; novel; premature; prevent; promoter; receptor; response; socioeconomics; steroid hormone; stressor; transcription factor; uterine smooth muscle cell

Preterm birth (PTB) affects 10-15% of pregnancies in the US and causes the majority of neonatal mortality and morbidity. To prevent PTB a clearer understanding is needed of the hormonal control of human parturition. In this regard, the steroid hormone progesterone (P4) acting via the nuclear P4 receptor (PR) isoforms, PR-A and PR-B, is a critical factor. For most of pregnancy P4/PR promotes uterine quiescence and blocks labor, and disruption of P4/PR signaling triggers parturition. The mechanism for these critical P4/PR actions are, however, unclear. Infection/inflammation in the uterine and gestational tissues are major drivers of term and preterm parturition, but the mechanism for these effects are also uncertain. The proposed research addresses these major knowledge gaps by exploring a mechanism linking inflammation and P4/PR signaling in myometrial cells via a phosphorylated form of PR-A that we hypothesize plays a central role in the causal pathway for inflammation-induced parturition. Our published and preliminary data suggest that P4/PR-B inhibits myometrial cell responsiveness to pro-inflammatory stimuli by interacting with and repressing the transcriptional activity of the activator protein 1 (AP-1) transcription factors at promotors of a subset of IL-1ß-responsive genes. Our data also suggest that P4/PR-A upon phosphorylation at the serine-344/345 locus (pSer344/345-PRA) interacts with AP-1 to disrupt P4/PR-B anti-inflammatory activity. We also found that generation of pSer344/345-PRA in myometrial cells is catalyzed by mitogen activated protein kinases (MAPKs) in response to pro-inflammatory stimuli. Based on those data we hypothesize that: 1) P4/PR-B exerts anti-inflammatory activity in myometrial cells by binding to AP-1 to inhibit transcription at a subset of inflammatory gene promoters; 2) pSer344/345-PRA inhibits P4/PR-B anti-inflammatory activity by disrupting the PR-B/AP-1 interaction, and 3) generation of pSer344/345-PRA in myometrial cells is catalyzed by specific MAPKs in response to pro-inflammation stimuli. This hypothesis will be tested in human myometrial cell lines and human myometrium obtained from c-section deliveries, and Rhesus macaque and mouse models of inflammation induced parturition. Two Specific Aims will be achieved: Specific Aim 1: Determine the mechanism by which P4/PR-B exerts anti-inflammatory activity in myometrial cells and how this is affected by pSer344/345-PRA; and Specific Aim 2: Determine how pSer344/345- PRA generation is controlled in myometrial cells. The proposed research is novel and groundbreaking and will advance understanding of the fundamental biology of human parturition and contribute to the development of effective P4/PR-based anti-inflammatory therapies to promote uterine quiescence and prevent preterm birth.

在美国，早产 (PTB) 影响 10-15% 的妊娠，并导致大部分新生儿死亡和发病。为了预防 PTB，需要更清楚地了解人类分娩的激素控制。在这方面，通过核 P4 受体 (PR) 亚型 PR-A 和 PR-B 发挥作用的类固醇激素孕酮 (P4) 是一个关键因素。在妊娠的大部分时间里，P4/PR 会促进子宫静止并阻止分娩，P4/PR 信号传导的破坏会触发分娩。然而，这些关键 P4/PR 作用的机制尚不清楚。子宫和妊娠组织的感染/炎症是足月和早产的主要驱动因素，但这些影响的机制也不确定。拟议的研究通过探索一种通过磷酸化形式的 PR-A 将炎症与子宫肌层细胞中的 P4/PR 信号传导联系起来的机制来解决这些主要的知识空白，我们假设 PR-A 在炎症诱导的分娩的因果途径中发挥着核心作用。我们发表的初步数据表明，P4/PR-B 通过与 IL-1β 反应基因子集启动子处的激活蛋白 1 (AP-1) 转录因子相互作用并抑制其转录活性，从而抑制子宫肌层细胞对促炎刺激的反应。我们的数据还表明，P4/PR-A 在丝氨酸 344/345 位点 (pSer344/345-PRA) 磷酸化后与 AP-1 相互作用，破坏 P4/PR-B 抗炎活性。我们还发现，子宫肌层细胞中 pSer344/345-PRA 的生成是由丝裂原激活蛋白激酶 (MAPK) 催化的，以响应促炎刺激。基于这些数据，我们假设：1) P4/PR-B 通过与 AP-1 结合抑制炎症基因启动子子集的转录，从而在子宫肌层细胞中发挥抗炎活性； 2) pSer344/345-PRA 通过破坏 PR-B/AP-1 相互作用来抑制 P4/PR-B 抗炎活性，3) 子宫肌层细胞中 pSer344/345-PRA 的生成是由响应促炎症刺激的特定 MAPK 催化的。这一假设将在人类子宫肌细胞系和剖腹产获得的人类子宫肌层以及炎症诱导分娩的恒河猴和小鼠模型中进行测试。将实现两个具体目标： 具体目标 1：确定 P4/PR-B 在子宫肌层细胞中发挥抗炎活性的机制以及 pSer344/345-PRA 如何影响这一机制；具体目标 2：确定子宫肌层细胞中如何控制 pSer344/345-PRA 的生成。拟议的研究是新颖且具有开创性的，将增进对人类分娩基本生物学的理解，并有助于开发基于 P4/PR 的有效抗炎疗法，以促进子宫静止并预防早产。