Sonnino S, Chigorno V
Study Center for the Functional Biochemistry of Brain Lipids, Department of Medical Chemistry and Biochemistry, LITA-Segrate, The Medical School, University of Milan, Via Fratelli Cervi 93, (Milan), 20090 Segrate, Italy.
Biochim Biophys Acta. 2000 Sep 18;1469(2):63-77. doi: 10.1016/s0005-2736(00)00210-8.
Gangliosides exist as a very complex mixture of species differing in both the hydrophilic and hydrophobic moieties. They are particularly abundant in the central nervous system (CNS), where they have been associated with development and maturation of the brain, neuritogenesis, synaptic transmission, memory formation and synaptic aging. Today, many data suggest that some of the effects exerted by gangliosides are due to interactions with proteins that participate in the transduction of signals through the membrane in membrane microdomains. A specific characteristic of CNS gangliosides is the structure of their long-chain base (LCB). In fact, considering all the mammalian cell sphingolipids, gangliosides, sulphatides, neutral glycosphingolipids, sphingomyelin and ceramides, it would seem that while the LCB with 18 carbons is the main component of all sphingolipids, only CNS gangliosides contain significant amounts of LCB with 20 carbons. C18-Sphingosine is always present in cell gangliosides; the individual ganglioside species containing C18-sphingosine increase during cell differentiation then remain constant during cell aging. Gangliosides containing C20-sphingosine are absent, or present only in traces, in undifferentiated cells but with the onset of cell differentiation they appear, their content slowly but continuously increasing throughout the life span. In this review we discuss the chemistry, physico-chemistry and metabolism of ganglioside species differing in LCB length and introduce the hypothesis that the varying ratio between C18- and C20-gangliosides during CNS development and aging can be instrumental in modulating membrane domain organisation and cell properties.
神经节苷脂以一种非常复杂的混合物形式存在，其亲水和疏水部分均有差异。它们在中枢神经系统（CNS）中尤为丰富，在那里它们与大脑的发育和成熟、神经突发生、突触传递、记忆形成以及突触老化有关。如今，许多数据表明，神经节苷脂产生的一些效应是由于与参与膜微区中跨膜信号转导的蛋白质相互作用所致。中枢神经系统神经节苷脂的一个特定特征是其长链碱基（LCB）的结构。事实上，考虑到所有哺乳动物细胞中的鞘脂，包括神经节苷脂、硫脂、中性糖鞘脂、鞘磷脂和神经酰胺，虽然含18个碳原子的LCB是所有鞘脂的主要成分，但似乎只有中枢神经系统神经节苷脂含有大量含20个碳原子的LCB。C18 - 鞘氨醇总是存在于细胞神经节苷脂中；含有C18 - 鞘氨醇的单个神经节苷脂种类在细胞分化过程中增加，然后在细胞衰老过程中保持恒定。含有C20 - 鞘氨醇的神经节苷脂在未分化细胞中不存在或仅微量存在，但随着细胞分化的开始它们出现，其含量在整个生命周期中缓慢但持续增加。在这篇综述中，我们讨论了LCB长度不同的神经节苷脂种类的化学、物理化学和代谢，并提出假说，即在中枢神经系统发育和衰老过程中，C18 - 和C20 - 神经节苷脂之间变化的比例可能有助于调节膜结构域组织和细胞特性。
