Detection of Mesenchymal Stem Cell Aging Using an Integrin Mechano‐Probe

Mesenchymal stem cells (MSCs) play a crucial role in cell therapy, but their efficacy diminishes with age. While biochemical methods like flow cytometry, immunoblotting, β-galactosidase labeling, and gene profiling are effective for screening MSC aging, mechanical factors also change with aging. After analyzing the transcriptomes of young and aged MSCs, we observed downregulation of adhesion-related genes and, based on those data, developed an integrin mechano-probe to measure integrin forces in MSCs. The probe's effectiveness was validated by mapping integrin forces in young and aged MSCs, revealing reduced integrin force signals in aged cells that correlated with downregulated expression of β1 integrins. This finding was further confirmed by flow cytometry and β-galactosidase staining. Overexpression of integrin β1 in aged MSCs restored mechanical signaling and increased p-ERK production, suggesting that the integrin β1/ERK pathway plays a role in rescuing the contractility of aged MSCs. Our mechano-probe enables distinguishing aged MSCs in a mixed pool of young and aged MSCs and identifying aged MSCs taken from mouse tissue. Integrin tension signals, as measured by a mechano-probe, may thus complement biochemical markers in assessing MSC aging.