Microflow induced mechanotransduction in hacat cells: a mechanistic study

Abstract

In recent years, fluid flow has been recognized as an important mechanical morphoregulator that governs cell fate in-vitro and in-vivo. Mechanisms underlying such cellular responses include flow induced shear stress, hydrodynamic pressure or formation of real time morphogen gradient inside the tissue. The epidermal keratinocytes are known to elict mechanosensitive response when exposed to cyclic strain and mechanical stretching; however influence of fluid flow induced shear stress on these cells still remains unexplored. In this regard, we used biomicrofluidics approach to evaluate to influence of flow induced shear stress on cytoskeletal reorganization of HaCaT cells (human keratinocytes) and to understand the mechanism underlying it. The study was carried out in shear stress range of 0.06 dyne/cm2 to 6.0 dyne/cm2. The study showed that a low shear stress of 0.06 dyne/cm2 caused the cellular spreading while the higher shear stress (6 dyne/cm2) resulted in cytoskeletal damage. It is important to mention that the shear stress of 0.06 dyne/cm2 elicited the cellular response via ERK1/2 > GSK3â > â catenin pathway. â catenin induces the transcription of proliferative gene, which was confirmed by the expression and nuclear localization of PCNA, proliferation marker. The scanning electron microscopic images of the confluent cell layer exposed to shear stress showed better integrity in comparison to the static control. In reality, though the skin keratinocytes are never exposed to the fluid flow, but these results propose a possible application of fluid flow induced shear stress in the cell sheet engineering in vitro.