title: Role of region-distinctive expression of Rac1 in regulating fibronectin arrangement during palatal shelf elevation.
abstract: Palatal shelf elevation is a crucial process in palate development, with the contribution of various factors. Disturbances in any factor during this process result in cleft palate. Prior to palatal shelf elevation starting from embryonic day 12.5, the Rac1 expression level in the bend region of the mid-palatal shelf progressively increases and the cell densities in the bend and groove regions gradually become higher than those in the middle region. The comparative decrease of cell density in the middle region is correlated with a gradual alteration of the arrangement of fibronectin (FN) fibers, whereas the bend and groove regions with higher cell densities maintain ring-like FN arrangements. Rac1 overexpression alters the fibrillar FN arrangement in the middle region to the ring-like arrangement by increasing cell density. This alteration is sufficient to induce the failure of palatal shelf elevation, ultimately leading to cleft palate. Furthermore, the inhibition of FN delays palatal shelf elevation. Thus, the spatiotemporal expression of Rac1 plays an impressive role in palatal shelf elevation by regulating FN arrangement within the palatal shelf.
authors.affiliation: Division in Anatomy and Developmental Biology, Department of Oral Biology, Oral Science Research Center, BK21 PLUS Project, Yonsei University College of Dentistry, Seoul, South Korea.
authors.forename: Qinghuang
authors.initials: Q
authors.lastname: Tang
authors.forename: Liwen
authors.initials: L
authors.lastname: Li
authors.forename: Chengri
authors.initials: C
authors.lastname: Jin
authors.forename: Jong-Min
authors.initials: JM
authors.lastname: Lee
authors.forename: Han-Sung
authors.initials: HS
authors.lastname: Jung
mesh_terms: D051378:Actin-Related Protein 3 / Q000378:metabolism; D000818:Animals; D002454:Cell Differentiation / Q000502:physiology*; D002972:Cleft Palate / Q000196:embryology*; D005353:Fibronectins / Q000378:metabolism*; D007150:Immunohistochemistry / Q000379:methods; D051379:Mice; D009479:Neuropeptides / Q000378:metabolism*; D010159:Palate / Q000196:embryology*; D020830:rac1 GTP-Binding Protein / Q000378:metabolism*
chemical_list: D051378:Actin-Related Protein 3; C495929:Actr3 protein, mouse; D005353:Fibronectins; D009479:Neuropeptides; C484602:Rac1 protein, mouse; D020830:rac1 GTP-Binding Protein