The Role of Nuclear Envelope Proteins in Differentiating Uniaxial Versus Biaxial Strain

Mechanical strain has profound effects on the development and survival of tissues. The ability of cells to sense and respond to mechanical forces is essential in key biological processes including development, proliferation and migration. Disruption of the ability to respond to mechanical forces has proven to be a critical factor in many diseases, such as cardiovascular disease, progeria and cancer. Due to the complexity of the human cell, it has been difficult to mimic the response of mechanical stimuli in vitro. This study demonstrates the use of uniaxial and biaxial cell stretching devices to investigate the differences in nuclear and cellular response to mechanical strain. Here, we compare lamins A/C, B1 and B2 expression in uniaxial versus biaxial stretching systems as nuclear lamin proteins are important factors that can sense and respond to mechanical forces. Uniaxially stretched cells display cellular re-orientation to redistribute the mechanical force, and upregulate nuclear lamins in order to increase stiffness. By contrast, biaxially stretched cells do not upregulate lamin A/C, B1 or B2 and do not re-orient in response to strain. In fact, we see a downregulation of all lamins when compared to not only uniaxially stretched cells, but also un-stretched cells.