Effects of fibroblasts on the function of acinar cells from the same human parotid gland

Background. Artificial salivary gland replacement would be an ideal treatment for xerostomia. In vivo, salivary gland cells are surrounded by a complex stromal environment in which fibroblasts are the main cell type in proximity to the gland cells. However, very little is known about the relationship between these fibroblasts and the gland cells. Methods. Parotid gland acinar cells (PGACs) and fibroblasts from the same human gland were cocultured. PGAC function-related protein expression was investigated. Results. The expression of alpha-amylase in PGACs was increased in a fibroblast ratio-dependent manner. Both fibroblast-conditioned medium and direct coculture also significantly enhanced the PGAC expression of alpha-amylase. Basic fibroblast growth factor (bFGF) seems to be a regulator of alpha-amylase expression in PGACs. Conclusion. An appropriate number of fibroblasts in contact with the PGACs is necessary to promote PGAC function. Fibroblast-secreted bFGF may play a paracrine signaling role in the regulation of alpha-amylase expression in PGACs. (C) 2015 Wiley Periodicals, Inc.