Expression of Grhl2 and Its Target Gene Products in Developing Mouse Submandibular Gland

Development of the salivary gland is characterized by extensive branching morphogenesis and lumen formation as well as differentiation into acinar and ductal cells. Although various molecules have been implicated in salivary gland development, transcription factors regulating the expression of those molecules and salivary gland development are largely unknown. The GRHL2 transcription factor and its target gene product SPINT1 as well as the SPINT1-regualted protease matriptase play crucial roles in epithelial development in several organs. Here we examined the expression of these epithelial regulators in developing mouse SMG. Of the three Grhl gene members, Grhl2 was the most abundant in embryonic SMG. The expression levels of GRHL2, SPINT1 and matriptase were increased during development of the gland. All of these molecules were expressed exclusively in the epithelial tissue. The present data may suggest the involvement of these molecules in SMG development and give a clue to developing a regenerative therapy of damaged salivary glands.