Ultrastructural Aspects of Rat Renal Tubular Epithelium <i>in Vitro</i>: Scanning Electron Microscopy （SEM） Analyses at Various Stages of Culture

Abstract

Renal tubular epithelial cells are capable of regenerating themselves after severe injury. In cellular regeneration, cell migration plays a crucial role. Previous studies have demonstrated that changes in cellular morphology, including the formation of lamellipodia, are very important in cell migration. However, the ultrastructure of a migrating cell largely remains undescribed. In the present study, we applied scanning electron microscopy techniques to cultured cells, and observed fine ultrastructural changes in cultured renal tubular epithelium during migration. We found that there were small sphere-like structures and/or microvilli on the cell surface of floating epithelia, that leaf-like structures closely resembling lamellipodia developed circumferentially in the early stages of culture, and that long and branched filopodia developed that were much larger in diameter compared to filopodia at earlier stages. To the best of our knowledge, these findings are new, and may contribute to the development of a new therapeutic strategy for severe tubular damage of the kidney.