Qin Ellen C, Ahmed Syeda T, Sehgal Poonam, Vu Vinh H, Kong Hyunjoon, Leckband Deborah E
Department of Materials Science and Engineering, University of Illinois, Urbana Champaign, USA.
Department of Chemical and Biomolecular Engineering, University of Illinois, Urbana Champaign, USA.
Biomaterials. 2020 May;239:119846. doi: 10.1016/j.biomaterials.2020.119846. Epub 2020 Feb 10.
The recent interest in exploiting cadherin-derived fragments to mimic intercellular adhesion in engineered hybrid biomaterials raises questions about which cadherin constructs effectively mimic cadherin interactions. This study compared the biophysical properties of and signaling initiated by three different, immobilized N-cadherin-derived fragments, in order to identify a minimal construct that mimics intercellular adhesion in biomaterials. Specifically, we compared: i) the full N-cadherin extracellular region with all five ectodomains (EC1-5), ii) the first two ectodomains (EC1-2) of N-cadherin, and iii) a peptide containing the histidine-alanine-valine-aspartic acid-valine (HAVDI) sequence in the first extracellular domain. Comparisons of the binding kinetics and affinities between each of these ligands and N-cadherin expressed on mesenchymal stem cells (MSCs) revealed quantitative differences. Nevertheless, MSCs exhibited similar, rigidity-dependent spreading and traction forces when cultured on gels displaying any of these N-cadherin ligands. There were, however, differences in cell signaling and secretory activities. MSCs cultured on the full N-cadherin extracellular domain (EC1-5) exhibited stiffness-dependent changes in nuclear YAP/TAZ localization and significantly higher secretion of vascular endothelial growth factor and insulin growth factor 1, compared to cells cultured on hydrogels displaying either EC1-2 or the HAVDI peptide. The increased paracrine secretion also enhanced myogenic differentiation. These findings reveal functional differences between N-cadherin derived ligands important for the design of biomaterials that mimic intercellular adhesion.
最近，利用钙黏蛋白衍生片段来模拟工程化混合生物材料中的细胞间黏附引起了人们的关注，这也引发了关于哪些钙黏蛋白构建体能够有效模拟钙黏蛋白相互作用的问题。本研究比较了三种不同的、固定化的N-钙黏蛋白衍生片段的生物物理特性以及它们引发的信号传导，以确定一种能够模拟生物材料中细胞间黏附的最小构建体。具体而言，我们比较了：i）包含所有五个胞外结构域（EC1-5）的完整N-钙黏蛋白胞外区域，ii）N-钙黏蛋白的前两个胞外结构域（EC1-2），以及iii）在第一个胞外结构域中包含组氨酸-丙氨酸-缬氨酸-天冬氨酸-缬氨酸（HAVDI）序列的肽段。对这些配体与间充质干细胞（MSC）上表达的N-钙黏蛋白之间的结合动力学和亲和力进行比较，揭示了定量差异。然而，当在展示这些N-钙黏蛋白配体的任何一种凝胶上培养时，MSC表现出相似的、刚性依赖性的铺展和牵引力。然而，细胞信号传导和分泌活性存在差异。与在展示EC1-2或HAVDI肽的水凝胶上培养的细胞相比，在完整的N-钙黏蛋白胞外区域（EC1-5）上培养的MSC在核YAP/TAZ定位上表现出刚性依赖性变化，并且血管内皮生长因子和胰岛素生长因子1的分泌显著增加。旁分泌分泌的增加也增强了肌源性分化。这些发现揭示了N-钙黏蛋白衍生配体之间的功能差异，这对于设计模拟细胞间黏附的生物材料很重要。
