Intrinsic mitotic activity supports the human salivary gland acinar cell population.

To develop treatments for salivary gland dysfunction, it is important to understand how human salivary glands are maintained under normal homeostasis. Previous data from our lab demonstrated that murine salivary acinar cells maintain the acinar cell population through self-duplication under conditions of homeostasis, as well as after injury. Early studies suggested that human acinar cells are mitotically active, but the identity of the resultant daughter cells was not clear. Using markers of cell cycle activity and mitosis, as well as an ex vivo 5-Ethynyl-2´-deoxyuridine assay, we show that human salivary gland acinar cells divide to generate daughter acinar cells. As in mouse, our data indicate that human salivary gland homeostasis is supported by the intrinsic mitotic capacity of acinar cells.