Mechanobiology of Acinar Stability

在第二个项目中，我们探索力如何调节黏附分子的亚细胞组织以促进腺泡的形态发生。虽然通常使用简化论的方法来阐明驱动发育和维持动态平衡的分子机制，但我们认为细胞和组织的行为是典型的可塑性，由粘附力介导，并由机械力改变。我们正在测试力在亚细胞水平上调节蛋白质的组织以改变组织水平上的细胞组织的想法，但多细胞组织的紧急性质和反馈机制改变了细胞对机械提示的反应。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检验这一观点。我们将测试力量是否调节整合素聚集，以驱动粪便粘连，并增强生长因子受体信号以改变腺泡的极性和形态。我们将使用细胞生物学方法来分析信号和腺泡的行为，通过使用工程基质和施加的剪切力，通过整合素簇的Palm和TIRF成像，以及对细胞表面糖蛋白、配体密度和细胞骨架操作的修改做出反应，来实现这一点。我们还将量化机械力如何通过正常的腺泡结构传播，了解HEW细胞对AT组织内的力的反应和传递力，并研究通过细胞-细胞和细胞-ECM相互作用协同调节组织稳态的HEW信号机制。这将通过使用生物物理技术对系统进行机械扰动(AFM和亚细胞激光消融)来实现，然后使用遗传指向力敏感光学探针观察系统的反应。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，以及这种反应是由多细胞组织的紧急属性控制的。这将通过修改现有的化学附着模型并建立一个集成但简化的模型来实现，该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.