Takaha N, Taira E, Taniura H, Nagino T, Tsukamoto Y, Matsumoto T, Kotani T, Sakuma S, Miki N
Department of Pharmacology 1, Osaka University School of Medicine, Japan.
Differentiation. 1995 Jun;58(5):313-20. doi: 10.1046/j.1432-0436.1995.5850313.x.
Neurite outgrowth factor, which promotes neurite extension from neuronal cells, is an extracellular matrix glycoprotein belonging to the laminin family. Gicerin is a protein that binds neurite outgrowth factor. Its cDNA cloning has revealed that it is a novel cell adhesion molecule belonging to the immunoglobulin super-family. Functional analysis demonstrates that gicerin possesses homophilic binding activity as well as heterophilic binding activity with neurite outgrowth factor. We examined the role and expression of neurite outgrowth factor and gicerin in chick kidney during development. In the embryonic kidney, gicerin was found to be highly expressed both on ureteric bud cells and metanephrogenic mesenchymal cells, when the mesenchymal cells become condensed to be converted into polarized epithelial cells. In the adult kidney, the expression of gicerin was decreased and restricted to the glomerulus, proximal tubule and medullary loop. On the other hand, neurite outgrowth factor was constitutively expressed in the basement membranes of tubules and the matrices of glomeruli during development. As some molecules which are expressed during embryogenesis and suppressed after maturation are re-expressed in tumor cells or tissues during regeneration, we also examined the expression of gicerin in chicken Wilms' tumor and regenerating kidney in interstitial nephritis. Gicerin was remarkably upregulated in Wilms' tumor and re-expressed in collecting ducts recovering from interstitial nephritis. These findings suggest that gicerin could play a role not only in normal renal development but also in oncogenesis and regeneration.
神经突生长因子可促进神经元细胞的神经突延伸，是一种属于层粘连蛋白家族的细胞外基质糖蛋白。Gicerin是一种能结合神经突生长因子的蛋白质。其cDNA克隆表明它是一种属于免疫球蛋白超家族的新型细胞粘附分子。功能分析表明，Gicerin具有同源结合活性以及与神经突生长因子的异源结合活性。我们研究了神经突生长因子和Gicerin在鸡肾脏发育过程中的作用和表达。在胚胎肾脏中，当间充质细胞浓缩转化为极化上皮细胞时，发现Gicerin在输尿管芽细胞和后肾间充质细胞上均高度表达。在成年肾脏中，Gicerin的表达下降并局限于肾小球、近端小管和髓袢。另一方面，神经突生长因子在发育过程中在肾小管的基底膜和肾小球的基质中持续表达。由于一些在胚胎发生期间表达而在成熟后受到抑制的分子在肿瘤细胞或组织再生期间会重新表达，我们还研究了Gicerin在鸡肾母细胞瘤和间质性肾炎再生肾脏中的表达。Gicerin在肾母细胞瘤中显著上调，并在从间质性肾炎恢复的集合管中重新表达。这些发现表明，Gicerin不仅可能在正常肾脏发育中发挥作用，而且在肿瘤发生和再生中也发挥作用。
