Program in Developmental Neurobiology, Institute of Molecular Medicine and Genetics, Georgia Regents University, Augusta, Georgia, United States of America.
PLoS One. 2013 Nov 29;8(11):e80841. doi: 10.1371/journal.pone.0080841. eCollection 2013.
Ceramide is a precursor for complex sphingolipids in vertebrates, while plants contain phytoceramide. By using a novel chromatography purification method we show that phytoceramide comprises a significant proportion of animal sphingolipids. Total ceramide including phytoceramide from mouse tissue (brain, heart, liver) lipid extracts and cell culture (mouse primary astrocytes, human oligodendroglioma cells) was eluted as a single homogenous fraction, and then analyzed by thin layer chromatography, and further characterized by gas chromatography-mass spectrometry (GC-MS). We detected a unique band that migrated between non-hydroxy fatty acyl ceramide and hydroxy fatty acyl ceramide, and identified it as phytoceramide. Using RT-PCR, we confirmed that mouse tissues expressed desaturase 2, an enzyme that has been reported to generate phytoceramide from dihydroceramide. Previously, only trace amounts of phytoceramide were reported in vertebrate intestine, kidney, and skin. While its function is still elusive, this is the first report of phytoceramide characterization in glial cells and vertebrate brain, heart, and liver.
神经酰胺是脊椎动物中复杂鞘脂类的前体，而植物中含有植物神经酰胺。通过使用一种新颖的色谱纯化方法，我们表明植物神经酰胺构成了动物鞘脂类的重要组成部分。来自小鼠组织（脑、心、肝）脂质提取物和细胞培养（原代小鼠星形胶质细胞、人少突胶质细胞瘤细胞）的总神经酰胺（包括植物神经酰胺）作为单一同质级分洗脱，并通过薄层色谱法进行分析，然后通过气相色谱-质谱法（GC-MS）进一步表征。我们检测到一个在非羟基脂肪酸酰神经酰胺和羟基脂肪酸酰神经酰胺之间迁移的独特条带，并将其鉴定为植物神经酰胺。通过 RT-PCR，我们证实小鼠组织表达了去饱和酶 2，该酶已被报道可从二氢神经酰胺生成植物神经酰胺。此前，仅在脊椎动物的肠道、肾脏和皮肤中报道了痕量的植物神经酰胺。虽然其功能尚不清楚，但这是植物神经酰胺在神经胶质细胞和脊椎动物脑、心和肝中的特征的首次报道。
