Adenoviral Transduction of a FRET-Based Sensor for Measuring Intracellular Tension in Primary Rat Mesenchymal Stem Cells

Abstract

Cytoskeletal tension changes play a key role in cellular responses to physical and mechanical cues. The FRET tension sensor Actinin-sst-FRET GR is a powerful tool for studying intracellular tension changes, offering the advantage of measuring intracellular mechanics in situ under culture conditions. However, its application faces challenges of low transfection efficiency and poor protein expression levels, particularly in primary cells. In this study, we developed an adenovirus vector for Actinin-sst-FRET GR and validated its expression in rat bone marrow mesenchymal stem cells (rMSCs). The adenoviral transduction approach significantly improved the efficiency of gene delivery and protein expression levels compared to chemical transfection methods. The sensor introduced via adenoviral infection exhibited FRET activity and normally responded to changes in actin cytoskeletal tension. Our findings demonstrate that adenoviral transduction is a highly effective gene delivery method for intramolecular FRET biosensors in stem cells, addressing key limitations of traditional methods. This approach provides a promising platform for in vitro investigations of intracellular mechanics across diverse cell types, including primary and stem cells, and serves as an alternative to animal experiments.