Expression of the Stem Cell Marker Nestin in Response to Tissue Injuries of Parotid Acinar Cells

Abstract

Since saliva is essential for maintenance of a healthy oral environment, the secretory function of the salivary gland is important in clinical dentistry. Although tissue injuries result in a decrease in acinar cells and consequent dysfunction of saliva secretion, the number of acinar cells recovers if the damage is not too severe. The origin of the regenerated acinar cells is unclear. One hypothesis is that acinar cells that are atrophied in response to tissue injuries can re-differentiate. We have previously established a primary culture of parotid acinar cells to study the mechanism of dysfunction and regeneration of salivary glands. During the culture, the expression levels of acinar markers decreased,whereas immature ductal markers increased, suggesting that the cells changed to immature duct-like cells. In this study, to clarify the properties of the cultured cells, the expression of nestin, a stem cell marker of the pancreas, was examined. It was found that nestin began to be expressed and increased during the culture. On immunofluorescence microscopy, nestin-expressing cells had secretory granules, indicating that the cells were derived from acinar cells. Src family kinase inhibitor PP1 suppressed the expression of nestin. It is possible that nestin expression is a programmed response to survive cellular stresses and to acquire re-differentiation potential.