RIKEN Center for Brain Science, Wako, Saitama, 351-0198, Japan.
Cellular Informatics Laboratory, RIKEN, Wako, Saitama, 351-0198, Japan.
Biochem Biophys Res Commun. 2021 Jan 15;536:73-79. doi: 10.1016/j.bbrc.2020.12.051. Epub 2020 Dec 24.
Cerebrospinal fluid (CSF) contains glycosphingolipids, including lactosylceramide (LacCer, Galβ(1,4)Glcβ-ceramide). LacCer and its structural isomer, galabiosylceramide (Gb, Galα(1,4)Galβ-ceramide), are classified as ceramide dihexosides (CDH). Gb is degraded by α-galactosidase A (GLA) in lysosomes, and genetic GLA deficiency causes Fabry disease, an X-linked lysosomal storage disorder. In patients with Fabry disease, Gb accumulates in organs throughout the body. While Gb has been reported to be in the liver, kidney, and urine of healthy individuals, its presence in CSF has not been reported, either in patients with Fabry disease or healthy controls. Here, we isolated CDH fractions from CSF of patients with idiopathic normal pressure hydrocephalus. Purified CDH fractions showed positive reaction with Shiga toxin, which specifically binds to the Galα(1,4)Galβ structure. The isolated CDH fractions were analyzed by hydrophilic interaction chromatography (HILIC)-electrospray ionization tandem mass spectrometry (ESI-MS/MS). HILIC-ESI-MS/MS separated LacCer and Gb and revealed the presence of Gb and LacCer in the fractions. We also found Gb in CSF from neurologically normal control subjects. This is the first report to show Gb exists in human CSF.
脑脊液 (CSF) 中含有糖脂，包括乳糖基神经酰胺 (LacCer，Galβ(1,4)Glcβ-神经酰胺)。LacCer 和其结构异构体半乳糖基神经酰胺 (Gb，Galα(1,4)Galβ-神经酰胺) 被归类为神经酰胺二己糖苷 (CDH)。Gb 在溶酶体中被α-半乳糖苷酶 A (GLA) 降解，而遗传 GLA 缺乏会导致 Fabry 病，这是一种 X 连锁溶酶体贮积症。在 Fabry 病患者中，Gb 会在全身各器官中积累。虽然已经报道 Gb 存在于健康个体的肝脏、肾脏和尿液中，但在 Fabry 病患者或健康对照者的 CSF 中，尚未有其存在的报道。在这里，我们从特发性正常压力脑积水患者的 CSF 中分离出 CDH 馏分。纯化的 CDH 馏分与特异性结合 Galα(1,4)Galβ 结构的志贺毒素呈阳性反应。分离的 CDH 馏分通过亲水作用色谱 (HILIC)-电喷雾串联质谱 (ESI-MS/MS) 进行分析。HILIC-ESI-MS/MS 将 LacCer 和 Gb 分离，并显示出这些物质存在于馏分中。我们还在神经正常的对照组 CSF 中发现了 Gb。这是首次报道 Gb 存在于人 CSF 中。
