Morphological and nanomechanical changes in mechanosensitive endothelial cells induced by colloidal AFM probes

Abstract

Mechanotransduction is one of the main properties of endothelial cells (ECs) phenotype. Hemodynamic forces like flow-generated endothelial shear stress play a fundamental role in ECs cytoskeletal remodeling and activate signaling cascades in ECs. AFM methods are widely used to characterize morphology as well as mechanical properties of cells. In both cases AFM probes directly interact with cell surface exerting mechanical forces on the cellular membrane, which in turn may stimulate mechanosensitive receptors present in EC. This article presents examples of how the colloidal AFM probes influence ECs during multiple scans. The results revealed that multiple scans of the ECs significantly influenced the morphology and elasticity of cells. Moreover, changes in the cell shape and mechanical properties were dependent on the scan direction (across or along the main axis of the cell). Multiple scans with a colloidal probe leaded to reorientation of the cell main axis and this effect was similar to the action of the shear stress induced by flow conditions. Furthermore, the correlation between the tip-induced modification of the cell properties and the remodeling of the cell's glycocalyx was observed. SCANNING 38:654-664, 2016. © 2016 Wiley Periodicals, Inc.

AFM-based detection of glycocalyx degradation and endothelial stiffening in the db/db mouse model of diabetes

“…For the control db/+ mice, the age-averaged value of the endothelium elastic modulus was E EC = 862 ± 16 Pa. This value is in agreement with the modulus value of the cytoplasm in endothelial cells measured in a glass microplate compression experiment 56 and with our previous in vitro studies 61 . For db/db mice, we observed a significant increase in the age-averaged value of the endothelium elastic modulus to 1449 ± 18 Pa. Our recent in vitro study revealed similar changes for EA.hy926 endothelial cells in response to chronic hyperglycaemia 31 .…”

Tracking Fenestrae Dynamics in Live Murine Liver Sinusoidal Endothelial Cells

“…However, in situ AFM studies on fresh and vital liver tissue biopsies will be more likely in the near future—i.e., similar to the AFM studies reported on breast biopsies—as this might bridge the gap between our present in vitro observations and in vivo observations. In case of future shear stress studies, it has been found using AFM that the endothelium presented different morphologies and nanomechanical properties when shear stress or hydrostatic pressure was applied. It is likely, therefore, that the number and dynamics of fenestrae could be affected by such conditions.…”

Biophysical nanocharacterization of liver sinusoidal endothelial cells through atomic force microscopy

“…The migration of cells remains random and does not depend on the direction of scanning. In another report, it was shown that continuous scanning in contact mode AFM resulted in an endothelial cell's remodelling and orientation in the scanning direction (Targosz-Korecka et al 2016). In QI mode, the contact time between the tip and the cell is vastly reduced and the loading force 2-3 times smaller than in the mentioned report.…”