The Effects on Flow-induced Shear Stress on the Maintenance of Stemness of Limbal Stem Cells

In this study we examined the effect of flow-induced shear stress in maintaining stem ness of limbal stem cells (LSCs). For this, the isolated LSCs from New Zealand white rabbits were subjected to flow-induced shear stress by a custom designed bioreactor. In isolating LSCs from the eye-balls the neighboring cells were not eliminated. Then two types of flow were adopted: steady and intermittent flow. The LSCs were cultured for up to 14 days. We conducted various biological analyses such as real-time PCR, immunofluorescence staining, Rhoda mine B staining. As results, the groups under flow-induced shear stresses exhibited changes in colony morphology, becoming larger and rounder, and forming dense populations regardless of flow type. In addition, LSC marker expression was enhanced. Cells under steady flow showed steady proliferation and higher expression of LSC markers, while epithelial cell marker expression was similar to that at an earlier stage. From this study, we concluded that engagement of flow-induced shear stress may even contribute to maintenance of stem ness. This study provides the first step of evidence that shear stress can be used for maintenance of LSCs, presenting a new source for mechanical stimulation in culture or maintaining LSCs´ characteristics.