Research groups such as Kyoto Sangyo University and the National University of Singapore have elucidated the mechanism by which dying epithelial cells in epithelial tissue undergo 'cell shedding'.
As the process of cell shedding known so far, it is known that cells that have reached the end of life are extruded from the tissue and leave the space, and neighboring cells quickly invade the space.However, the details of the complex and delicate coordination between deciduous cells and neighboring cells have not been elucidated. The role of 'apoptotic bodies' was also poorly understood.
In this study, using mammalian epithelial cells, we investigated the mechanism that drives cell shedding by live imaging and mathematical model analysis.In shedding epithelial cells, the enzyme scramblase replaces lipids in the lipid bilayer of the cell membrane, exposing phosphatidylserine to the outer layer.They found that this part was torn off to form an apoptotic body, creating a space for neighboring cells to invade, and that the deciduous cells were quickly extruded.
In addition, the formation of apoptotic bodies has been observed from mammals to insects.Therefore, cell loss through the formation of apoptotic bodies is considered to be a universal mechanism that transcends species.
Furthermore, it was clarified that inhibition of the formation of apoptotic bodies in the experimental system prevented cell loss and disrupted the homeostasis of the epithelial tissue.It has been thought that when abnormal epithelial cell shedding occurs, the barrier function of the epithelium is lowered and is involved in inflammatory diseases such as enteritis.This strongly suggests the relationship between the failure of the cell shedding mechanism and the disease.
The results of this research are expected to lead to new understanding of inflammatory diseases and development of treatment methods.
Paper information:[Developmental Cell] Apoptotic extracellular vesicle formation via local phosphatidylserine exposure drives efficient cell extrusion
