Slim Christiaan L, van IJzendoorn Sven C D, Lázaro-Diéguez Francisco, Müsch Anne
Department of Cell Biology; University of Groningen; University Medical Center Groningen; Groningen, The Netherlands.
Department of Developmental and Molecular Biology; Albert Einstein College of Medicine; The Bronx, NY, USA.
Bioarchitecture. 2014 Mar-Apr;4(2):47-52. doi: 10.4161/bioa.29012. Epub 2014 Apr 25.
Columnar epithelia (e.g., kidney, intestine) and hepatocytes embody the two major organizational phenotypes of non-stratified epithelial cells. Columnar epithelia establish their apical and basal domains at opposing poles and organize in monolayered cysts and tubules, in which their apical surfaces form a single continuous lumen whereas hepatocytes establish their apical domains in the midst of their basolateral domains and organize a highly branched capillary luminal network, the bile canaliculi, in which a single hepatocyte can engage in lumen formation with multiple neighbors. To maintain their distinct tissue architectures, columnar epithelial cells bisect their luminal domains during symmetric cell divisions, while the cleavage furrow in dividing hepatocytes avoids bisecting the bile canalicular domains. We discuss recently discovered molecular mechanisms that underlie the different cell division phenotypes in columnar and hepatocytic model cell lines. The serine/threonine kinase Par1b determines both the epithelial lumen polarity and cell division phenotype via cell adhesion signaling that converges on the small GTPase RhoA.
柱状上皮细胞（如肾、肠）和肝细胞体现了非分层上皮细胞的两种主要组织表型。柱状上皮细胞在相对的两极建立其顶端和基底结构域，并组织形成单层囊肿和小管，其中它们的顶端表面形成一个单一的连续管腔，而肝细胞在其基底外侧结构域中间建立其顶端结构域，并组织形成高度分支的毛细血管管腔网络，即胆小管，单个肝细胞可与多个相邻细胞参与管腔形成。为维持其独特的组织结构，柱状上皮细胞在对称细胞分裂过程中将其管腔结构域二等分，而分裂中的肝细胞的分裂沟则避免二等分胆小管结构域。我们讨论了最近发现的分子机制，这些机制是柱状和肝细胞模型细胞系中不同细胞分裂表型的基础。丝氨酸/苏氨酸激酶Par1b通过汇聚于小GTP酶RhoA的细胞黏附信号，决定上皮管腔极性和细胞分裂表型。
