Deciphering the Molecular Dynamics of Cell Adhesion and the Role of Biomechanics in Ehlers-Danlos Syndrome

细胞与环境形成的联系是生物体最基本的过程之一，异常联系会导致病理状况的发展。整合素是通过形成对组织完整性至关重要的黏附部位来调节这些连接到周围的细胞外基质(ECM)的。根据病理情况，整合素异构体的表达水平会发生变化，这可能发生在结缔组织疾病Ehler-Danlos综合征(EDS)中。EDS细胞显示纤维连接蛋白受体整合素的表达减少，随之而来的是替代受体整合素的募集。然而，人们也假设这些黏附位点的分子组成也决定了它们的强度和稳定性，最终影响肌动蛋白细胞骨架和细胞的生物力学特性，这在EDS中还没有研究过。这些粘附点形成的机械力化学细节也仍然知之甚少。我们建议使用一种新开发的检测方法，使用功能化弹性体来模拟ECM，从而允许控制细胞培养所在的机械和生化环境。这使得研究黏附蛋白类型和混合物在黏附部位形成中的作用。弹性体与单轴细胞拉伸器的组合还允许在细胞黏附过程中施加应力。活细胞显微镜与图像分析工具相结合来量化成像数据，将提供对细胞黏附动力学的更深层次的洞察。通过这一点，我们试图了解整合素图谱的改变如何影响细胞的机械性能，黏附位置和肌动球蛋白动力学如何随着机械刺激的反应而变化，以及这是否会在EDS中受到影响。该项目的结果将为我们理解在EDS等条件下维持组织完整性所涉及的过程提供重大进展。

The connections a cell forms with its environment underlies one of the most fundamental processes of organisms, with aberrant connections leading to the development of pathological conditions. Integrins are essential for mediating these connections to the surrounding Extracellular Matrix (ECM) through formation of adhesion sites which are crucial for tissue integrity. Depending on pathological condition, the expression level of integrin isoforms change, which may be occurring in the connective tissue disorder Ehlers-Danlos Syndrome (EDS). EDS cells display a reduced expression of the fibronectin receptor integrin with the consequent recruitment of the alternative receptor integrin. However, it is also assumed the molecular composition of these adhesion sites also sets their strength and stability, ultimately influencing the actin cytoskeleton and a cell's biomechanical properties which has not been studied in EDS. The mechanochemical details of the formation of these adhesion sites also remain poorly understood. We propose using a newly developed assay that employs functionalised elastomers to mimic the ECM, allowing control of the mechanical and biochemical environment into which cells are cultured. This allows to study the role of adhesion protein type and mixture in adhesion site formation. Combination of the elastomer to a uniaxial cell-stretcher also allows for stresses to be applied during cell adhesion. Live cell microscopy combined with image analysis tools to quantify imaging data will then provide deeper insights into the dynamics of cell adhesion. Through this, we seek to understand how an altered integrin profile can affect the mechanical properties of the cell, how adhesion site and actomyosin dynamics change in response to mechanical stimuli, and if this is affected in EDS. The results of this project will provide major advances in our understanding of the processes involved in maintaining tissue integrity in conditions like EDS.