Expression of keratinocyte biomarkers is governed by environmental biomechanics

In solid body tissues, environmental biomechanics is indispensable for tissue homeostasis. While characteristics of homeostasis include morphogenesis, proliferation and differentiation, the influences through biomechanics in corneal keratinocytes are poorly understood. Here we show for the first time that corneal keratinocytes, established in a defined biomechanical microenvironment of micropatterned soft pillars, exhibit favoritism of late and terminal differentiation at large pillar patterns of 11 μm with matched small 5 μm arrays. At 11 μm, epithelial cells expressed decreased levels of early differentiation marker cytokeratin 19 (KRT19), which was antagonized by an increase in biomarkers of late and terminal differentiation, i.e. cytokeratin 12 (KRT12), involucrin and filaggrin. Keratinocytes showed proper morphogenesis on 5 μm arrays, whereas 11 μm yielded in morphological disorders. While the propensity of keratinocyte proliferation appeared attenuated at large pillar patterns, stem cell marker ABCG2 was weak though homogeneous at 5 μm, but strong at 11 μm. Thus, corneal keratinocytes reveal interference of biomarker expression, morphogenesis and proliferation, which are at least in part characteristics of tissue homeostasis by mechanisms, depending on environmental biomechanics of micropattern-allocated cell adhesion points in vitro.