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.

项目概要 作为德克萨斯儿童医院的儿科医生，该医院是美国最大的儿童医院，也是儿童医疗中心 先天性巨结肠症 (HSCR) 的治疗——一种由肠神经系统 (ENS) 缺陷引起的疾病 在发展过程中，我不仅致力于提供出色的手术护理，而且还致力于破译背后的机制 疾病病因学。在我的实践中，我切除了异常的无神经节肠并拉通了“正常” 节状肠道，但仍对近 50% 的术后肠道发生率感到困惑 功能障碍。因此，作为一名有抱负的外科医生科学家，我的目标是研究导致的产后机制 在这些不良的术后结果中。 K08 计划是开发技术和知识的理想基础 我需要科学技能来为我的患者带来转化影响。本申请列出了五年 教育和研究计划的重点是确定术后持续功能障碍的驱动因素 神经节化 HSCR 结肠微环境。肠神经元长期以来被认为是机械性的 对外力（轴向拉伸和径向膨胀）和内在力学（组织刚度）敏感，两者 HSCR 手术前后均存在。目前尚不清楚这些力如何影响 ENS 表型和 功能，这就提出了是否已知机械敏感离子通道和/或粘着斑的问题 激酶 (FAK) 信号传导可能是 ENS 对张力反应的病理生理学介质。与我们一致 从逻辑上讲，离子通道 Piezo1 和粘着斑分子 FAK 普遍存在于胃肠道中 道，但它们在 ENS 对生物力学力的反应中的作用需要进一步研究。我的数据表明 HSCR 肠道在基线时 ECM 失调，导致组织硬度变化，并且 外力进一步使 ECM 失调。尽管如此，目前还不清楚 ECM 中的这些变化是如何发生的。 微环境调节 ENS。因此，我们假设肠道上的生物力学力 Piezo1-FAK 对 ENS 的影响依赖于 ENS，并以控制 ENS 的方式调节 ECM 成分 微环境，最终导致 HSCR 肠道功能障碍。我将解决这个研究问题 在我的导师 Keswani 博士和专家科学顾问委员会的指导下，我们实现了两个目标。在目标 1 中， 我将定义临床相关的外在机械力对正常肠道和 HSCR 肠道中 ENS 的作用。 这将使我能够在活细胞钙成像、离体组织培养和 体内张力模型，用于评估 ENS 对外在机械力的响应中 Piezo1-FAK 的信号传导。 目标 2 将重点测试生物力学力如何调节 ECM 以改变 ENS 微环境 HSCR，以及 ECM 的变化是否预示 HSCR 的术后预后。为了这个目标，我将 使用新型生物力学和水凝胶模型来研究 ENS 和 ECM 之间的相互作用， 并利用人类 HSCR 组织特征开发一种新型风险预测模型。完成这些目标将 开启我作为一名外科医生科学家的职业生涯，对患者的护理产生有意义的影响。