Cell Migration Control through Modulation of Multiple Directional Cues

摘要 该项目的目标是使用工程化的细胞外基质环境，利用结构和代谢， 细胞外基质的化学控制，以检查细胞对多种细胞因子的反应机制。 定向迁移线索细胞迁移在许多生理和病理过程中起着重要作用， 如伤口愈合、发展和癌症侵袭。移民往往不是随机的， 而是通过识别排列的细胞外基质纤维或硬度梯度而导向靶， 分别产生接触引导和硬旋转。在许多生物学背景下， 同时，迫使细胞整合这些信息。例如，刚度梯度和对齐的胶原蛋白， 在伤口床内产生Gen以引导真皮成纤维细胞迁移。类似的纤维结构和gra- 肿瘤微环境刺激癌细胞迁移出肿瘤微环境和正常细胞，包括基质细胞， 和免疫细胞向肿瘤微环境迁移。虽然人们对细胞如何再生有了明确的认识， 尽管细胞会对单个方向性线索产生反应，但实际上对细胞如何整合多种线索并 基于这种集成做出迁移决策。此外，还有一种假设， 和硬旋转是重叠的定向细胞迁移机制，但这还没有经过严格的测试。 多线索定向迁移的机制理解将需要对F- 肌动蛋白和微管网络起作用。事实上，一些证据表明，接触指导和durotax- 它可能使用稍微不同的F-肌动蛋白网络结构，因为接触指导被认为是由F-肌动蛋白控制的。 肌动蛋白纤维结构，但硬脊膜不是。将采用工程方法设计体外环境 其允许在2D和3D环境中对接触引导和硬旋转进行独立调整。此外─ 更重要的是，F-肌动蛋白的分支，集束和收缩的作用，使细胞更喜欢排列的胶原纤维， 将测试刚度的梯度。这将揭示涉及的共享或竞争分子途径 当这两个方向性迁移线索单独或一起出现时。了解细胞如何- 响应多个线索的光栅在包括组织工程在内的几个生物医学领域具有广泛的影响 和疾病治疗学。确定细胞如何在体外对多种线索作出反应将使我们能够预测细胞 在伤口愈合、发展、癌症侵袭和免疫应答中的反应，导致候选药物 如癌症或增强伤口愈合和免疫反应的策略。

ABSTRACT The goal of this project is to use engineered extracellular matrix environments leveraging structural and me- chanical control over the extracellular matrix to examine the mechanisms by which cells respond to multiple directional migration cues. Cell migration plays an important role in many physiological and pathological pro- cesses such as wound healing, development and cancer invasion. Frequently migration is not simply random, but directed towards targets through recognition of aligned extracellular matrix fibers or gradients in stiffness, generating contact guidance and durotaxis, respectively. In many biological contexts these cues are presented simultaneously, forcing cells to integrate this information. For instance, gradients of stiffness and aligned colla- gen are generated within the wound bed to direct dermal fibroblast migration. Similar fiber structures and gra- dients stimulate cancer cell migration out of the tumor microenvironment and normal cells including stromal and immune cells towards the tumor microenvironment. While there is a firm understanding of how cells re- spond to individual directional cues, virtually nothing is known about how cells integrate multiple cues and make migrational decisions based on that integration. Furthermore, there is a hypothesis that contact guidance and durotaxis are overlapping directional cell migration mechanisms, but this has not been rigorously tested. Mechanistic understanding of multi-cue directional migration will require a refined understanding of how the F- actin and microtubule networks operates. Indeed, some evidence suggests that contact guidance and durotax- is may use slightly different F-actin network structures, since contact guidance is thought to be governed by F- actin fiber structures, but durotaxis is not. Engineering approaches will be taken to design in vitro environments that allow for independent tuning of contact guidance and durotaxis in both 2D and 3D environments. Further- more, the effect of F-actin branching, bundling and contraction in allowing cells to prefer aligned fibers of colla- gen or gradients of stiffness will be tested. This will uncover shared or competing molecular pathways involved when these two directional migration cues are present in isolation and together. Understanding how cells mi- grate in response to multiple cues has broad impact on several biomedical fields including tissue engineering and disease therapeutics. Determining how cells respond to multiple cues in vitro will allow us to predict cell responses in wound healing, development, cancer invasion and immune response leading to drug candidates as in cancer or strategies to enhance wound healing and immune response.