Vijayakumar Soundarapandian, Takito Jiro, Gao XiaoBo, Schwartz George J, Al-Awqati Qais
Department of Medicine, College of Physicians and Surgeons of Columbia University, 630 W 168th St, New York, NY 10032, USA.
J Cell Sci. 2006 Dec 1;119(Pt 23):4797-801. doi: 10.1242/jcs.03269.
Epithelia, the most common variety of cells in complex organisms exist in many shapes. They are sheets of polarized cells that separate two compartments and selectively transport materials from one to the other. After acquiring these general characteristics, they differentiate to become specialized types such as squamous columnar or transitional epithelia. High density seeding converts a kidney-derived cell line from flat ;generic' epithelial cells to columnar cells. The cells acquire all the characteristics of differentiated columnar cells, including microvilli, and the capacity for apical endocytosis. The high seeding density induces the deposition of a new protein termed hensin and polymerization of hensin is the crucial event that dictates changes in epithelial phenotype. Hensin is widely expressed in most epithelia. Its deletion in mice leads to embryonic lethality at the time of generation of the first columnar epithelium, the visceral endoderm. Moreover many human cancers have deletions in the hensin gene, which indicates that it is a tumor suppressor.
上皮细胞是复杂生物体中最常见的细胞类型，有多种形态。它们是极化细胞片层，分隔两个腔室，并选择性地将物质从一个腔室运输到另一个腔室。在获得这些一般特征后，它们分化成为特殊类型，如鳞状、柱状或移行上皮细胞。高密度接种可将源自肾脏的细胞系从扁平的“普通”上皮细胞转变为柱状细胞。这些细胞获得了分化柱状细胞的所有特征，包括微绒毛和顶端内吞作用的能力。高接种密度诱导一种名为hensin的新蛋白质沉积，hensin的聚合是决定上皮细胞表型变化的关键事件。Hensin在大多数上皮细胞中广泛表达。在小鼠中删除该基因会导致在第一个柱状上皮即脏内胚层形成时胚胎致死。此外，许多人类癌症中hensin基因存在缺失，这表明它是一种肿瘤抑制因子。
