Ultrastructure and mechanical property of angiotensin II-stimulated tubular cells pretreated with angiotensin II type 1 receptor blocker

Atomic force microscopy (AFM) has become an important device to visualize various cells and biological materials for non-invasive imaging. The major advantage of AFM compared to the conventional optical and electron microscopes is its convenience. Sample preparation for AFM does not need special coating or vacuum as a procedure. AFM can detect samples even under the aqueous condition. Although the AFM is originally used to obtain surface topography of sample, it can measure precisely the interactions between its probe tip and the sample surface from force-distance measurements. Epithelial- to-mesenchymal transformation of tubular cells into myofibroblastic phenotype is an important mediator of renal injury in chronic nephropathy. It is generally known that angiotensin II plays a direct profibrotic role in the kidney, but the mechanism is unclear. In this study, we observed structural and mechanical changes in tubular epithelial cell after angiotensin II and angiotensin II receptor inhibitor treatment using AFM.