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.

项目摘要 作为德克萨斯州儿童医院的一名儿科外科医生，德克萨斯州儿童医院是全国最大的儿童医院，也是 先天性巨结肠（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，我不仅努力提供出色的外科护理，而且还努力破译背后的机制。 疾病病因学在我的实践中，我删除异常，无神经节的肠和拉通过“正常” 但仍被近50%的术后肠梗阻发生率所困扰 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这种结果的产后机制。 术后效果不佳K 08计划是开发技术和 我需要的科学技能来对我的病人产生转化的影响。本申请提出了一个为期五年的 教育和研究计划的重点是确定持续性术后功能障碍的驱动因素， 神经节HSCR结肠微环境。肠神经元长期以来被认为是机械的 对外力（轴向拉伸和径向扩张）和内在力学（组织硬度）敏感， 在HSCR手术之前和之后存在。尚不清楚这些力如何影响ENS表型， 功能，这就提出了一个问题，即是否已知的机械敏感离子通道和/或局部粘附 FAK信号可能是ENS对张力反应的病理生理介质。符合我们 逻辑上，离子通道Piezo 1和粘着斑分子FAK普遍存在于胃肠道中 束，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。我的数据显示 HSCR肠道在基线时具有失调的ECM，这导致组织硬度的变化， 外力进一步使ECM失调。尽管如此，目前仍不清楚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 Piezo 1-FAK对ENS的依赖性作用，并以支配ENS的方式调节ECM成分 微环境，其最终导致HSCR中的肠道功能障碍。我将回答这个研究问题 在我的导师Keswani博士和专家科学顾问委员会的指导下，在目标1中， 我将定义在正常和HSCR肠道中ENS上的临床相关外在机械力的作用。 这将使我能够在活细胞钙成像，离体组织培养和生物医学方面发展新的技术专长。 体内张力模型，以评估Piezo 1-FAK在ENS对外部机械力响应中的信号传导。 目标2将侧重于测试生物力学力如何调节ECM以改变ENS微环境， HSCR，以及ECM的变化是否指示HSCR的手术后预后。为此，我将 使用新的生物力学和水凝胶模型研究ENS和ECM之间的相互作用， 并利用人类HSCR组织特征开发了一种新的风险预测模型。实现这些目标将 开始我作为外科医生科学家的职业生涯，对我的病人的护理产生有意义的影响。