Mechanobiology of Acinar Stability

在项目二中，我们探讨了力如何调节粘附分子的亚细胞组织以促进腺泡形态发生。虽然还原论的方法通常用于阐明驱动发育和维持稳态的分子机制，但我们认为细胞和组织行为是表型可塑的，由粘附介导并由机械力修饰。我们正在测试这样一种观点，即力在亚细胞水平上调节蛋白质的组织，从而在组织水平上改变细胞组织，但多细胞组织的涌现特性和反馈机制改变了细胞对机械信号的反应。我们将通过研究机械力调节腺泡形态发生和稳定性的机制来验证这一观点。我们将测试力是否调节整联蛋白聚集，以驱动粪便粘连和增强生长因子受体信号传导，从而改变腺泡极性和形态。我们将使用细胞生物学方法，通过使用工程基质和施加的剪切力，并通过整合素聚类的PALM和TIRF成像，并响应于细胞表面糖蛋白，配体密度和细胞骨架操作的修饰，来测定信号传导和腺泡行为。我们还将量化机械力如何通过“正常”腺泡结构传播，以了解新细胞对组织内的力的响应和传递，并研究通过细胞-细胞和细胞-ECM相互作用介导的新信号传导机制协同调节组织稳态。这将通过使用生物物理技术来机械扰动系统（AFM和亚细胞激光消融），然后使用遗传导向的力敏光学探针观察系统的反应来实现。最后，我们将建立模型来测试细胞对力表现出综合反应的概念，这种反应是由多细胞组织的涌现特性决定的。这将通过修改现有的化学粘附模型来实现，并建立一个集成但简化的模型，由分子细节提供信息，模拟整个系统并跨越多个空间和时间尺度。

In project two we explore how force regulates subcellular organization of adhesion molecules to promote acini morphogenesis. While a reductionist approach is typically used to clarify the molecular mechanisms that drive development and maintain homeostasis, we take the view that cell and tissue behavior are phenotypically plastic, mediated by adhesion and modified by mechanical force. We are testing the idea that force regulates the organization of proteins at the subcellular level to alter cellular organization at the tissue level but that emergent properties of multi cellular tissues and feedback mechanisms alter the responsiveness of cells to mechanical cues. We will test this idea by investigating the mechanisms by which mechanical force regulates acinar morphogenesis and stability. We will test whether force modulates integrin clustering, to drive fecal adhesions and enhance growth factor receptor signaling to modify acinar polarity and morphology. We will achieve this using cell biological approaches that assay signaling and acini behavior, through the use of engineered matrices and applied shear force and through PALM and TIRF imaging of integrin clustering and in response to modifications in cell surface glycoproteins, ligand density and cytoskeletal manipulations. We will also quantify how mechanical forces spread though 'normal' acinar structures te understand hew cells respond to and transmit forces within at tissue and investigate hew signaling mechanisms mediated through cell-cell and cell-ECM interactions synergize to regulate tissue homeostasis. This will be achieved by using biophysical techniques to mechanically perturb the system (AFM and subcellular laser ablation) and by then watching the system respond using genetically directed force-sensitive optical probes. Finally we will build models to test the concept that cells exhibit an integrated response to force and that this response is governed by emergent properties of multi cellular tissues. This will be achieved by modifying existing chemical-adhesion models and also building an integrated but simplified model, informed by molecular details, that simulates the whole system and that spans multiple spatial and temporal scales.