Tubulointerstitial fibrosis represents the major underlying pathology of diabetic nephropathy where loss of
cell-to-
cell adhesion is a critical step. To date, research has predominantly focussed on the loss of
cell surface molecular binding events that include altered protein ligation. 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-β1 treated kidney
cells of the
human proximal tubule (HK2). AFM indentation of TGF-β1 treated HK2
cells showed a significant increase (42%) in the elastic modulus (stiffness) compared to control. Fluorescence microscopy confirmed that increased
cell stiffness is accompanied by reorganization of the cytoskeleton. The corresponding changes in stiffness, due to F-actin rearrangement, affected the work of detachment by changing the separation distance between two adherent
cells. Overall, our novel data quantitatively demonstrate a correlation between
cellular elasticity, adhesion and early morphologic/phenotypic changes associated with
tubular injury.
From the Clinical Editor
Diabetes affects many patients worldwide. One of the long term problems is diabetic nephropathy. Here, the authors utilized atomic force microscopy single cell force spectroscopy (AFM- SCFS) to study cellular stiffness and cell adhesion after TGF1 treatment in human proximal tubule kidney cells. The findings would help further understand the overall disease mechanism in diabetic patients.