Remodeling of cell adhesion molecules and cytoskeleton is important in regulating cell shape and migration. In our laboratory, we have focused on the cell adhesion molecule integrin and the actin-binding adapter molecule filamin, which plays a role in the intracellular skeleton. Melnick-Needles syndrome, which has a gene mutation in filamin-A, has the characteristic findings of congenital tooth deficiency, enamel hypoplasia, and root abnormalities (brachial teeth). It has been reported so far that filamin-A is essential for cell migration and is considered to coexist with actin filaments. Double staining of odontogenic epithelial cells (SF2 cells) showed that filamin-A overlapped on the cell membrane side of F-actin and showed a characteristic pattern. In addition, SF2 cells in which the expression of the endogenous filamin-A gene was suppressed by overexpressing shRNA-filamin-A were prepared, and cell proliferation and cell migration ability were examined.

Expression of filamin-A in tooth germ development was analyzed by immunohistostaining. Immunohistolocalization of filamin-A in cultured dental epithelial cell line SF2 cells was analyzed by immunostaining with anti-filamin-A antibody. Melnick-needles syndrome (MNS) which one of the OPD spectrum disorder that localized mutation filamin-A was reported. This patient had shortened root of primary teeth with thin enamel. To observe in detail the dynamics of actin filaments, the cells expressing GFP label F-actin was prepared and observed by Time-laps recording. Actin polymerization and movement of actin filaments in SF2-FLNA shRNA cells is inhibited has been revealed. In SF2-FLNA shRNA cells, the movement distance of actin filaments was the half degree of the SF2 cells.

Analysis of tooth development is important to understand the pathogenic mechanism of disease with tooth agenesis and dysplasia.Filamin-A is a molecule regulate the cytoskeletal organization of cells.Mutations of filamin-A gene lead to localized neuronal migration disorder.Our group discovered a patient with Melnick-Needles syndrome with enamel hypoplasia and short root caused mutation of filamin-A gene. To analyze the role of Filamin-A in cell migration, dental epithelial cells SF2 were plated and scratched to 3 mm width non-cell area. Further, to knockdown endogenous filamin-A, SF2 cells was transfected with shRNA to filamin-A.This result suggested that filamin-A is important for dental epithelial cell migration.