Quantifying cellular mechanics and adhesion in renal tubular injury using single cell force spectroscopy

<p>AbstractTubulointerstitial fibrosis represents the major underlying pathology of diabetic nephropathywhere loss of cell-to-cell adhesion is a critical step. To date, research has predominantlyfocussed on the loss of cell surface molecular binding events that include altered proteinligation. In the current study, atomic force microscopy single cell force spectroscopy (AFM-SCFS) was used to quantify changes in cellular stiffness and cell adhesion in TGF-?1treated kidney cells of the human proximal tubule (HK2). AFM indentation of TGF-?1 treatedHK2 cells showed a significant increase (42%) in the Elastic modulus (stiffness) compared tocontrol. Fluorescence microscopy confirmed that increased cell stiffness is accompanied byreorganization of the cytoskeleton. The corresponding changes in stiffness, due to F-actinrearrangement, affected the work of detachment by changing the separation distancebetween two adherent cells. Overall, our novel data quantitatively demonstrate a correlationbetween cellular elasticity, adhesion and early morphologic/phenotypic changes associatedwith tubular injury.</p>