Department of Cell and Molecular Biology and Pathogenic Bioagents, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Avenida Bandeirantes 3900, Ribeirão Preto, SP, Brazil.
J Histochem Cytochem. 2010 Jan;58(1):83-93. doi: 10.1369/jhc.2009.954776. Epub 2009 Sep 28.
Gangliosides are known to be important in many biological processes. However, details concerning the exact function of these glycosphingolipids in cell physiology are poorly understood. In this study, the role of gangliosides present on the surface of rodent mast cells in maintaining cell structure was examined using RBL-2H3 mast cells and two mutant cell lines (E5 and D1) deficient in the gangliosides, GM(1) and the alpha-galactosyl derivatives of the ganglioside GD(1b). The two deficient cell lines were morphologically different from each other as well as from the parental RBL-2H3 cells. Actin filaments in RBL-2H3 and E5 cells were under the plasma membrane following the spindle shape of the cells, whereas in D1 cells, they were concentrated in large membrane ruffles. Microtubules in RBL-2H3 and E5 cells radiated from the centrosome and were organized into long, straight bundles. The bundles in D1 cells were thicker and organized circumferentially under the plasma membrane. The endoplasmic reticulum, the Golgi complex, and the secretory granule matrix were also altered in the mutant cell lines. These results suggest that the mast cell-specific alpha-galactosyl derivatives of ganglioside GD(1b) and GM(1) are important in maintaining normal cell morphology.
神经节苷脂在许多生物过程中起着重要作用。然而，关于这些糖脂在细胞生理学中的确切功能的细节还了解甚少。在这项研究中，使用 RBL-2H3 肥大细胞和两种缺乏神经节苷脂 GM(1)和 GD(1b)的α-半乳糖基衍生物的突变细胞系（E5 和 D1），研究了存在于啮齿动物肥大细胞表面的神经节苷脂在维持细胞结构中的作用。这两个缺陷细胞系在形态上彼此不同，也与亲本 RBL-2H3 细胞不同。RBL-2H3 和 E5 细胞中的肌动蛋白丝位于细胞膜下，跟随细胞的纺锤形，而在 D1 细胞中，它们集中在大的膜皱襞中。RBL-2H3 和 E5 细胞中的微管从中心体辐射，并组织成长而直的束。D1 细胞中的束更厚，并在细胞膜下呈圆周状排列。内质网、高尔基体和分泌颗粒基质在突变细胞系中也发生了改变。这些结果表明，肥大细胞特异性的神经节苷脂 GD(1b)和 GM(1)的α-半乳糖基衍生物在维持正常细胞形态中起着重要作用。
