A multiplexed tension sensor reveals the distinct levels of integrin-mediated forces in adherent cells†

Integrins are crucial for cell adhesion, spreading, and cell–cell interactions, contributing significantly to cellular functions. Various tension sensors have been developed to measure integrin tensions across different cell types and conditions. However, there is a lack of tools to accurately calibrate the high-level force range of integrins required for cell adhesion. In this study, we engineered a multiplexed tension sensor (TS) by combining a yellow fluorescence protein tension sensor (YFP TS) with a DNA integrative tension sensor (ITS) previously used. This innovative approach enabled us to detect integrin-mediated forces in adherent cells. Our findings revealed that high-motile fish keratocytes exhibited integrin-mediated forces ranging from 44 to 100 pN, whereas low-motile 3T3L1 and NRK cells generated integrin-mediated forces exceeding 100 pN. This difference may be attributed to the shorter dwelling time or interaction time between an integrin and a RGD ligand in keratocytes, suggesting a need to examine the loading rate information for the integrin and the ligand in focal adhesions.