생쥐 치아발생과정 중 상아모세포에서 Dynamin II의 발현

Abstract

The Dynamin II was known as a GTPase protein and it has been contributed a variety of vesicular budding events such as endocytotic membrane fission, caveolae internalization and protein trafficking in the Golgi apparatus. The tooth development proceeds sequentially bud, cap and bell stage. Odontobalsts exhibit a tall columnar shape and establish a continuous single layer with a clear epithelioid appearance. They orchestrate a series of complex mechanism that result in mineralization of dentin. Odontobalst cells secrete a collagen-based matrix and release numerous membrane-bound matrix vesicle. The vesicles surrounding organic matrix initiate the mineral deposition in dentin. The expression and function of Dynamin II in odontoblast differentiation has not yet been reported. Therefore, we investigate the expression and possible role of the Dynamin II in odontoblast during developing tooth and mineralization. The Dynamin II mRNA and protein expressed during differentiation in MDPC-23 cells. The expression level of mRNA and protein were significantly high at early stage of differentiation and then gradually decreased after that. Also, the result of immunohistochemisty showed that Dynamin II not localized embryonic day 17 (E17) and 21 (E21) under early bell stage. However, Dynamin II was expressed strongly in the odontoblast layer at postnatal day 1 (PN1) and gradually decreased at postnatal day 3 (PN3) and 5 (PN5). Also, Dynamin II protein was expressed also in odontoblastic process as well as in adjacent the nuclear region at postnatal day 15 (PN15) on the functional stage. The length of odontoblast was increased gradually from PN1 to PN15 and decreased at postnatal day 21 (PN21). In conclusion, Dynamin II may relate with transport the vesicle containing collageneous and non-collageneous protein for formation of dentin in odontoblast.

Key Words: Dynamin II, Tooth development, Odontoblast Differentiation, MDPC-23 cell