Oh Jeongah, Muralidharan Sneha, Zhao Qing, Scholz Johannes, Zelnik Iris D, Blumenreich Shani, Joseph Tammar, Dingjan Tamir, Narayanaswamy Pradeep, Choi Hyungwon, Hayen Heiko, Torta Federico, Futerman Anthony H
Precision Medicine Translational Research Programme and Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; SLING, Singapore Lipidomics Incubator, Life Sciences Institute, National University of Singapore, Singapore.
Cardiovascular-Metabolic Disease Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
J Lipid Res. 2025 Jul;66(7):100832. doi: 10.1016/j.jlr.2025.100832. Epub 2025 May 29.
The sphingolipidome contains thousands of structurally distinct sphingolipid (SL) species. This enormous diversity is generated by the combination of different long-chain bases (LCBs), N-acyl chains and head groups. In mammals, LCBs are N-acylated with different fatty acids (from C14 to C32, with different degrees of saturation) by six ceramide synthases (CerS1-6) to generate dihydroceramides (DHCer), with each CerS exhibiting specificity toward acyl-Coenzyme As of defined chain length. CerS2 synthesizes very-long chain dihydroceramide, and mice in which CerS2 has been deleted display a number of pathologies. We now expand previous analyses of the mouse sphingolipidome by examining 259 individual SL species in 18 different tissues, building an extensive SL tissue atlas of WT and CerS2 null mice. Although many of the changes in SL levels were similar to those reported earlier, a number of unexpected findings in CerS2 null mouse tissues were observed, such as the decrease in ceramide 1-phosphate levels in the brain, the increase in C26-SL levels in the lung, and no changes in levels of ceramides containing t18:0-LCBs (phytosphinganine). Furthermore, analysis of levels of other metabolites revealed changes in at least six major metabolic pathways, including some that impinge upon the SL metabolism. Together, these data highlight the complex changes that occur in the lipidome and metabolome upon depletion of CerS2, indicating how sphingolipids are connected to many other pathways and that care must be taken when assigning a relationship between tissue pathology and one or other specific SL species.
鞘脂组包含数千种结构不同的鞘脂(SL)种类。这种巨大的多样性是由不同的长链碱基(LCB)、N-酰基链和头部基团组合而成的。在哺乳动物中,六种神经酰胺合酶(CerS1 - 6)将LCB与不同的脂肪酸(碳链长度从C14到C32,饱和度不同)进行N-酰化,生成二氢神经酰胺(DHCer),每种CerS对特定链长的酰基辅酶A具有特异性。CerS2合成极长链二氢神经酰胺,CerS2基因缺失的小鼠表现出多种病理症状。我们现在通过检测18种不同组织中的259种个体SL种类,扩展了先前对小鼠鞘脂组的分析,构建了野生型和CerS2基因敲除小鼠的广泛鞘脂组织图谱。尽管许多鞘脂水平的变化与先前报道的相似,但在CerS2基因敲除小鼠组织中观察到了一些意外发现,例如大脑中神经酰胺1-磷酸水平的降低、肺中C26-SL水平的升高,以及含有t18:0-LCB(植物鞘氨醇)的神经酰胺水平没有变化。此外,对其他代谢物水平的分析揭示了至少六种主要代谢途径的变化,包括一些影响鞘脂代谢的途径。总之,这些数据突出了CerS2缺失后脂质组和代谢组中发生的复杂变化,表明鞘脂如何与许多其他途径相互关联,并且在确定组织病理学与一种或其他特定鞘脂种类之间的关系时必须谨慎。