Corneal epithelial cells exposed to shear stress show altered cytoskeleton and migratory behaviour

Abstract

Cells that form the corneal epithelium, the outermost layer of the cornea, are exposed to shear stress through blinking during waking hours. In this in vitro study, the effect of fluid shear stress on human corneal epithelial cells (HCECs) was investigated. Following exposure to shear stresses of 4 and 8 dyn/cm2, HCECs showed cytoskeletal rearrangement with more prominent, organized and elongated filamentous actin. Cytoskeletal changes were time-dependent, and were most significant after 24 hours of shear stress. Higher rates of migration and proliferation, as evaluated by a scratch assay, were also observed following 24 hours of low shear stress exposure (4 dyn/cm2). This result contrasted the poor migration observed in samples scratched before shear exposure, indicating that shear-induced cytoskeletal changes played a key role in improved wound healing and must therefore precede any damage to the cell layer. HCEC cytoskeletal changes were accompanied by an upregulation in integrin β1 and downregulation of ICAM-1. These results demonstrate that HCECs respond favourably to flow-induced shear stress, impacting their proliferation and migration properties as well as phenotype.

A novel patient‐oriented numerical procedure for glaucoma drainage devices

“…These vortex patterns induce higher velocity gradient at surface of ocular tissues (cornea and iris) and consequently influence the wall shear stress. It is important to analyse the wall shear stress at the ocular tissues since values beyond the threshold limit can cause detachment of ocular cells, affecting the normal biological function of eye …”

“…In the current numerical study, the largest skin friction coefficient is calculated for the case of iris, standing position, in the presence of SSD (black dashed lines), and is around 1.6, which corresponds to a wall shear stress value of 8 ⋅ 10 −7 Pa. Based on the study of Molladavoodi et al and Gerlach et al, wall shear stress in the range of 0.8 to 1.5 Pa is required for the detachment of ocular cells; therefore, no risk is encountered based on the present simulations.…”

Keratinocytes are mechanoresponsive to the microflow‐induced shear stress

“…Thus, we checked the actin distribution in the keratinocytes exposed to various shear stressed. We observed a thin actin network at the cellular periphery maintained at the static condition Molladavoodi et al, 2017;Orr et al, 2006). Notably, Kim et al (2012) showed that shear stress as low as 0.02 dyne/cm 2 was sufficient to induce cytoskeletal remodeling in the human Caco-2 intestinal epithelial cells.…”

“…Flow-induced mechanoresponsiveness has widely been studied in various epithelial cell types (Duan et al, 2008;Kim et al, 2012;Maggiorani et al, 2015;Molladavoodi et al, 2017). With this perspective, we analyzed the effects of shear stress on skin keratinocytes.…”

“…Fluid flow‐induced shear stress has been recognized as mechanostimuli for various epithelial cell types including corneal epithelial cells (Kang et al, ; Molladavoodi, Robichaud, Wulff, & Gorbet, ), renal epithelial cell (Duan et al, ; Maggiorani et al, ; Verma, Ye, & Hua, ; Wang, Heo, & Hua, ), alveolar epithelial cell (Flitney, Kuczmarski, Adam, & Goldman, ), and intestinal epithelial cells (Chi et al, ; Kim et al, ; Kim, Huh, Hamilton, & Ingber, ). However, the impact of the flow‐induced shear stress on the skin epithelial cells (keratinocytes) has not been explored yet.…”