Hierarchical Micro-Nano Topography Promotes Cell Adhesion and Osteogenic Differentiation via Integrin α2-PI3K-AKT Signaling Axis

• Main Authors: Huimin Zheng, Yujuan Tian, Qian Gao, Yingjie Yu, Xianyou Xia, Zhipeng Feng, Feng Dong, Xudong Wu, Lei Sui
• Format: Article
• Language: English
• Published: Frontiers Media S.A. 2020-05-01
• Series: Frontiers in Bioengineering and Biotechnology
• Subjects: topography; adhesion; osteogenic differentiation; integrin α2; PI3K-AKT
• Online Access: https://www.frontiersin.org/article/10.3389/fbioe.2020.00463/full

Surface topography dictates important aspects of cell biological behaviors. In our study, hierarchical micro-nano topography (SLM-AHT) with micro-scale grooves and nano-scale pores was fabricated and compared with smooth topography (S) and irregular micro-scale topography (SLA) surfaces to investigate mechanism involved in cell-surface interactions. Integrin α2 had a higher expression level on SLM-AHT surface compared with S and SLA surfaces, and the expression levels of osteogenic markers icluding Runx2, Col1a1, and Ocn were concomitantly upregulated on SLM-AHT surface. Moreover, formation of mature focal adhesions were significantly enhanced in SLM-AHT group. Noticablely, silencing integrin α2 could wipe out the difference of osteogenic gene expression among surfaces with different topography, indicating a crucial role of integrin α2 in topography induced osteogenic differentiation. In addition, PI3K-AKT signaling was proved to be regulated by integrin α2 and consequently participate in this process. Taken together, our findings illustrated that integrin α2-PI3K-AKT signaling axis plays a key role in hierarchical micro-nano topography promoting cell adhesion and osteogenic differentiation.