Investigating the role of biomechanical forces on the enteric nervous system in Hirschsprung disease

研究生物力学力对先天性巨结肠症肠神经系统的作用

• 批准号: 10975058
• 负责人: Lily S Cheng
• 金额: $ 16.55万
• 依托单位: UNIVERSITY OF VIRGINIA
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-30 至 2027-07-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10975058
• 关键词: Investigating; role; biomechanical; forces; enteric

PROJECT SUMMARY As a pediatric surgeon at Texas Children’s Hospital, the nation’s largest children’s hospital and a central hub for the treatment of Hirschsprung’s disease (HSCR)—a disorder caused by defective enteric nervous system (ENS) development, I strive not only to deliver excellent surgical care, but also to decipher the mechanisms behind disease etiology. In my practice, I remove the abnormal, aganglionic intestine and pull-through “normal” ganglionated intestine but continue to be perplexed by the nearly 50% incidence of postoperative bowel dysfunction. Thus, my goal as an aspiring surgeon-scientist is to investigate the postnatal mechanisms that result in these poor postoperative outcomes. The K08 program is an ideal foundation to develop the technical and scientific skills I need to make translational impact for my patients. The present application lays out a five-year educational and research plan focused on identifying drivers of persistent postoperative dysfunction in the ganglionated HSCR colon microenvironment. Enteric neurons have long been recognized as mechanically sensitive to extrinsic force (axial stretch and radial distention) and intrinsic mechanics (tissue stiffness), both of which are present before and after HSCR surgery. It is not known how these forces affect ENS phenotype and function, which raises the question of whether known mechanosensitive ion channels and/or focal adhesion kinase (FAK) signaling could be pathophysiological mediators of ENS responses to tension. Consistent with our logic, the ion channel Piezo1 and focal adhesion molecule FAK are ubiquitously present in the gastrointestinal tract, but their role in ENS response to biomechanical forces requires further investigation. My data demonstrates that HSCR intestine at baseline has a dysregulated ECM, which leads to changes in tissue stiffness, and that extrinsic force further dysregulates the ECM. Still, it remains unclear how these changes in the ECM microenvironment regulate the ENS. Therefore, we hypothesize that biomechanical forces on the intestine have Piezo1-FAK dependent effects on the ENS and regulate ECM composition in a manner that governs the ENS microenvironment, which ultimately contributes to gut dysfunction in HSCR. I will address this research question in two aims, under the guidance of my mentor, Dr. Keswani, and expert scientific advisory committee. In Aim 1, I will define the role of clinically relevant, extrinsic mechanical forces on the ENS in normal and HSCR intestine. This will allow me to develop new technical expertise in live cell calcium imaging, ex vivo tissue culture, and in vivo tension models to evaluate the signaling of Piezo1-FAK in ENS responses to extrinsic mechanical forces. Aim 2 will focus on testing how biomechanical forces regulate the ECM to alter the ENS microenvironment in HSCR, and whether changes in the ECM are indicative of post-surgical prognosis in HSCR. In this aim, I will work with novel biomechanical and hydrogel models to investigate the interaction between the ENS and ECM, and develop a novel risk prediction model using human HSCR tissue features. Completion of these aims will launch my career as a surgeon-scientist with meaningful impact for the care for my patients.

项目总结 作为德克萨斯儿童医院的儿科外科医生，德克萨斯儿童医院是美国最大的儿童医院，也是 先天性巨结肠(HSCR)的治疗--一种由肠道神经系统(ENS)缺陷引起的疾病 为了发展，我不仅努力提供优质的外科护理，而且还努力破译背后的机制 疾病病因学。在我的实践中，我切除了不正常的、无神经节的肠子，并拉出了“正常”。 肠神经节样变，但仍为近50%的术后肠病发生率所困扰 功能障碍。因此，作为一名有抱负的外科医生兼科学家，我的目标是研究导致 在这些糟糕的术后结果中。K08计划是开发技术和 我需要的科学技能为我的病人带来翻译上的影响。本申请列出了一个为期五年的 教育和研究计划的重点是确定持续的术后功能障碍的驱动因素 神经节细胞HSCR结肠微环境。肠神经元长时间以来一直被认为是机械的 对外力(轴向拉伸和径向扩张)和内在力学(组织硬度)都很敏感 它们在HSCR手术前后都存在。目前尚不清楚这些因素是如何影响ENS表型和 功能，这提出了一个问题，即是否已知的机械敏感离子通道和/或焦点粘连 激酶(FAK)信号转导通路可能是ENS对张力反应的病理生理介质。与我们的 逻辑上，离子通道Piezo1和焦点黏附分子FAK在胃肠道中普遍存在 但它们在ENS对生物机械力的反应中所起的作用还需要进一步研究。我的数据显示 HSCR肠在基线时有一个失调的ECM，这会导致组织僵硬的变化，而且 外力进一步扰乱了细胞外基质。尽管如此，尚不清楚ECM的这些变化是如何发生的 微环境对ENS起着调节作用。因此，我们假设肠道上的生物力学作用力 PIEZO1-FAK对ENS的依赖作用及以调控ENS的方式调节ECM组成 微环境，这最终导致HSCR的肠道功能障碍。我将回答这个研究问题 在我的导师科斯瓦尼博士和专家科学咨询委员会的指导下，有两个目标。在目标1中， 我将确定临床上相关的外在机械力在正常和HSCR肠道中对ENS的作用。 这将使我在活细胞钙成像、体外组织培养和 活体张力模型评估Piezo1-FAK在ENS对外力反应中的信号转导。 目标2将重点测试生物力学如何调节ECM以改变ENS的微环境。 HSCR，以及ECM的变化是否预示着HSCR手术后的预后。为了这个目标，我将 使用新的生物力学和水凝胶模型来研究ENS和ECM之间的相互作用， 并开发了一种新的利用人类HSCR组织特征的风险预测模型。完成这些目标将 作为一名外科科学家，我开始了我的职业生涯，对我的病人护理产生了有意义的影响。