Pesheva P, Kuklinski S, Schmitz B, Probstmeier R
Department of Physiology, Neurophysiology, University of Bonn, Germany.
J Neurosci Res. 1998 Dec 1;54(5):639-54. doi: 10.1002/(SICI)1097-4547(19981201)54:5<639::AID-JNR9>3.0.CO;2-2.
Galectin-3 is a member of the galectin family and belongs to a group of soluble beta-galactoside-binding animal lectins. The molecule is expressed by neural and nonneural cells intra- (cytoplasm and nucleus) as well as extra-cellularly (plasma membrane and extracellular space). By using an in vitro cell-substratum adhesion assay, we have addressed the question whether galectin-3 present in the extracellular milieu may support the adhesion and/or neurite outgrowth of neural cells in a manner analogous to cell adhesion molecules. Galectin-3 was immobilized as a substratum and various cell types, N2A (neuroblastoma), PC12 (pheochromocytoma), and TSC (transformed Schwann cells) cell lines, neural cells from early postnatal mouse cerebellum, and dorsal root ganglion neurons from newborn mice were allowed to adhere to the lectin. Here we show that all cell types studied specifically adhered to galectin-3 by the following criteria: 1) the number of adherent cells was dependent on the galectin-3 concentration used for coating; 2) adhesion of cells to galectin-3, but not to collagen type I or laminin was inhibited by polyclonal antibodies to galectin-3; 3) upon addition of asialofetuin (a polyvalent carrier of terminal beta-galactosides) to the cell suspension prior to the adhesion assay, cell adhesion to galectin-3 was inhibited in a dose-dependent manner; and 4) cell adhesion to galectin-3 was abolished by treatment of cells with endo-beta-galactosidase. In addition, the adhesion of dorsal root ganglion neurons to galectin-3 could be inhibited by lactose. Notably, substratum-bound galectin-3 promoted the outgrowth of neurites from dorsal root ganglia explants and this neurite outgrowth promoting activity could be inhibited by polyclonal antibodies to galectin-3.
半乳糖凝集素-3是半乳糖凝集素家族的成员，属于一组可溶性β-半乳糖苷结合动物凝集素。该分子在细胞内（细胞质和细胞核）以及细胞外（质膜和细胞外空间）由神经细胞和非神经细胞表达。通过使用体外细胞-基质粘附试验，我们研究了细胞外环境中存在的半乳糖凝集素-3是否可能以类似于细胞粘附分子的方式支持神经细胞的粘附和/或神经突生长。将半乳糖凝集素-3固定为基质，使各种细胞类型，N2A（神经母细胞瘤）、PC12（嗜铬细胞瘤）和TSC（转化的雪旺细胞）细胞系、出生后早期小鼠小脑的神经细胞以及新生小鼠的背根神经节神经元粘附于该凝集素。在此我们表明，所有研究的细胞类型均通过以下标准特异性粘附于半乳糖凝集素-3：1）粘附细胞的数量取决于用于包被的半乳糖凝集素-3浓度；2）半乳糖凝集素-3多克隆抗体可抑制细胞与半乳糖凝集素-3的粘附，但不抑制与I型胶原或层粘连蛋白的粘附；3）在粘附试验前向细胞悬液中加入去唾液酸胎球蛋白（末端β-半乳糖苷的多价载体），细胞与半乳糖凝集素-3的粘附呈剂量依赖性抑制；4）用内切β-半乳糖苷酶处理细胞可消除细胞与半乳糖凝集素-3的粘附。此外，乳糖可抑制背根神经节神经元与半乳糖凝集素-3的粘附。值得注意的是，基质结合的半乳糖凝集素-3促进了背根神经节外植体神经突的生长，并且这种神经突生长促进活性可被半乳糖凝集素-3多克隆抗体抑制。
