Biomechanical Regulation in Human Neural Induction

神经管缺陷是最常见的出生缺陷之一，每年影响全球50多万婴儿。神经管缺陷会导致严重的健康问题，包括腿部瘫痪，脑损伤，甚至死亡。为了开发预防和诊断神经管缺陷的新方法，需要对中枢神经系统的发育有基本的了解。使用动物模型，调节神经诱导（中枢神经系统发育的第一阶段）的遗传和生化因素已部分解开。最近的研究表明，神经诱导过程中细胞命运的决定是由生物力学线索调节的。 这种机械机制知之甚少，很难使用动物模型进行研究。本研究将建立一系列新的细胞培养工具，以研究神经诱导过程中的遗传、生化和生物力学相互作用。这些新工具将提供以较低成本进行实验的能力，并且不使用动物受试者来确定对神经管形成的机械影响。将收集关于细胞的机械环境如何在神经管发育期间改变其行为的基本数据。 主要研究者将吸引来自不同种族背景和性别的K-12，本科生和研究生参与这项跨学科的生物工程研究，并鼓励他们追求科学和工程事业。该项目将测试机械相互作用决定神经发育中的形态发生事件的假设。已知微图案化的细胞培养环境导致人类细胞模仿神经板的神经上皮细胞和神经板边缘细胞的空间图案化，因此将用于模拟神经诱导。药物治疗和一种新的装置，局部扩大位于指定区域的微图案的细胞，以动态调节细胞的形状和力，将被用来研究如何在体外神经诱导模型中的细胞空间图案调节细胞的形状和力。将研究神经诱导中的机械转导途径，重点关注雅普、BMP和Wnt信号的功能参与。最后，将开发与微图案化平台集成的径向化学梯度生成装置，以询问生化梯度是否也可以在神经诱导期间诱导细胞空间图案化，以及细胞形状和力是否在生化梯度的下游作用或独立工作以确定谱系规范。使用具有微调化学和机械环境能力的集成微系统，这项研究首次提供了神经发育中生物化学和生物力学线索之间相互作用的定量分析。

Neural tube defects are among the most common birth defects and affect more than 500,000 infants worldwide each year. Neural tube defects can result in severe health problems, including paralysis of legs, brain damage, and even death. To develop novel approaches for the prevention and diagnosis of neural tube defects, a fundamental understanding of the development of the central nervous system is required. Using animal models, genetic and biochemical factors that regulate neural induction, the first stage of the central nervous system development, have been partially unraveled. Recent studies suggest that the cell fate decision in the neural induction is regulated by biomechanical cues. This mechanical mechanism is poorly understood and very difficult to study using animal models. This research will build a series of novel cell culture tools to investigate the genetic, biochemical and biomechanical interactions during neural induction. These new tools will provide the ability to perform experiments with lower costs and not using animal subjects to determine the mechanical effects on neural tube formation. Fundamental data on how the mechanical environment of the cells changes their behavior during neural tube development will be collected. The principal investigator will engage K-12, undergraduate and graduate students with diverse ethnic backgrounds and genders with this interdisciplinary bioengineering research, and encourage them to pursue science and engineering careers.This project will test the hypothesis that mechanical interactions dictate morphogenic events in neural development. Micropatterned cell culture environments are known to cause human cells to mimic the spatial patterning of neuroepithelial cells and neural plate border cells of the neural plate, and thus will be used to model neural induction. Drug treatment and a novel device which locally expands the cells located in the designated regions of micropatterns to dynamically regulate cell shape and force will be used to investigate how cell spatial patterning in the in vitro neural induction model regulates cell shape and force. The mechanotransduction pathways in neural induction will be investigated, focusing on the functional involvement of YAP, BMP and Wnt signals. Lastly, a radial chemical gradient generation device integrated with the micropatterning platform will be developed to interrogate whether biochemical gradient can also induce cell spatial patterning during neural induction, and whether cell shape and force act downstream of biochemical gradient or work independently to determine lineage specification. Using integrative microsystems with the capability to fine-tune chemical and mechanical environment, this research provides for the first time a quantitative analysis of the interactions between biochemical and biomechanical cues in neural development.