Abstract
The data presented here pertain to a research article entitled "Structural characterization and dynamics of globotetraosylceramide in vascular endothelial cells under TNF-α stimulation" (Okuda et al., 2010). The present article provides additional structural and gene expression data for the characterization of a TNF-α-inducible glycosphingolipid, globotetraosylceramide (Gb4), in vascular endothelial cells. (i) Structural details of Gb4 in lipid raft-enriched cell membranes were determined by MALDI-TOF MS. These analyses identified Gb4 with very-long-chain fatty acids as the major molecular species in this fraction, and the expression levels of whole molecular species of Gb4 with different fatty acid structures in the membrane are uniformly upregulated by TNF-α stimulation. (ii) The expression levels of genes encoding enzymes for synthesis of the ceramide portion of Gb4 were analyzed by real-time PCR. These assays revealed that TNF-α stimulation promotes transcription of the Elovl1 and Cers5 genes, which are involving in the synthesis of Gb4 with very-long-chain fatty acids. Collectively, these results indicate that TNF-α regulates glycosphingolipid synthesis and lipid raft formation in vascular endothelial cells via transcriptional up-regulation of related genes. These data thus provide new insights useful for understanding the molecular basis of inflammation-associated pathology in vascular endothelia.