Cadherins and Cell Stiffening

 描述(申请人提供)：细胞之间的黏附和细胞外基质是所有多细胞生物体的基本特征。最近的工作表明，施加在细胞黏附受体上的机械力，包括钙粘附素和整合素，可以影响Rho家族GTP酶的活性，从而影响细胞骨架的组织和细胞的僵硬。这项资助旨在了解钙粘附素信号如何产生细胞僵硬所需的细胞骨架重排，重点是了解细胞从哪里获得支持细胞僵硬所需的能量。在我们的初步研究中，我们发现对E-钙粘附素施加作用力可以刺激葡萄糖摄取，并增加质膜上的葡萄糖转运蛋白。利用分子、生物化学和细胞生物学方法，目标1将确定E-钙粘附素如何刺激葡萄糖摄取的分子机制。目标2将确定葡萄糖摄取增加如何促进僵硬所需的细胞骨架重排。在这里，我们的目标是确定RhoA激活剂和涉及的信号通路。使用磁性镊子和涂有E-钙粘蛋白胞外区的珠子，我们将确定力量诱导的葡萄糖摄取如何导致钙粘附素介导的粘连的加强。最终目的是研究压力诱导的葡萄糖如何影响肌动蛋白细胞骨架及其对体内细胞生长和转移的调节。将利用乳腺癌的小鼠模型来探索促进E-钙粘素介导力传递对疾病的影响。当这项提案中的工作完成后，我们希望建立一个新的范例，说明葡萄糖摄取是如何被力刺激并促进细胞僵硬的。这一范例可以应用于更好地理解其他蛋白质的力量传递，并将为理解E-钙粘素力量传递是否以及如何防止癌症的发展奠定基础。

 DESCRIPTION (provided by applicant): Adhesion of cells to one another and the extracellular matrix is a fundamental characteristic of all multicellular organisms. Recent work has shown that mechanical force applied to cell adhesion receptors, including the cadherins and integrins, can affect the activities of Rho family GTPases, thereby influencing the organization of the cytoskeleton and the stiffness of cells. This grant is aimed at understanding how signals from cadherins produce the cytoskeletal rearrangements necessary for cell stiffening, with an emphasis on understanding where the cell derives the energy required to support cell stiffening. In our preliminary studies, we discovered that application of force to E-cadherin stimulates glucose uptake and increases glucose transporters on the plasma membrane. Using molecular, biochemical and cell biological approaches, Aim 1 will define the molecular mechanism for how E-cadherin stimulates glucose uptake. Aim 2 will determine how increased glucose uptake facilitates the cytoskeletal rearrangements required for stiffening. Here we aim to identify the RhoA activator and signaling pathways involved. Using magnetic tweezers and beads coated with the extracellular domain of E-cadherin we will determine how force-induced glucose uptake leads to the strengthening of cadherin-mediated adhesions. The final aim will investigate how the force-induced glucose impacts the actin cytoskeleton and its regulation of cell growth and metastasis in vivo. Mouse models of breast cancer will be employed to explore the consequence that promoting E-cadherin mediated force transmission has on disease. When the work in this proposal is complete, we expect to establish a new paradigm for how glucose uptake is stimulated by force and facilitates cell stiffening. This paradigm can be applied to better understand force transmission by other proteins and will lay the groundwork for understanding if and how E- cadherin force transmission protects against the development of cancer.