| Autor: |
Jia Wei, Wang, Elaine, Kelly, Samuel, Sullards, Cameron, Merrill, Alfred |
| Předmět: |
|
| Zdroj: |
FASEB Journal; Apr2007, Vol. 21 Issue 5, pA240-A240, 1/5p |
| Abstrakt: |
Utilizing the uniform protocols established by the LIPID MAPS Consortium (www.lipidmaps.org), RAW 264.7 cells were treated with Kdo2-Lipid A, a defined endotoxin that activates macrophages via TLR-4, then the composition of the major sphingolipids were analyzed by electrospray tandem mass spectrometry. Approximately 4 h after Kdo2-Lipid A addition, there were large increases in ceramides, sphingomyelins and glycosphingolipids comprised of various sphingoid base (i.e., sphingosine and sphinganine) and fatty acid backbones. The increases were confirmed to be due to elevated de novo sphingolipid biosynthesis by analysis of the incorporation of [U-13C]palmitate into sphingolipids as well as inhibition by ISP1 (myriocin), a serine palmitoyltransferase (SPT) inhibitor. Microarray analysis by the Macrophage Biology/Functional Genomics Core (C. Glass, Director) determined that SPT mRNA was increased by Kdo2-Lipid A treatment; however, analysis of SPT activity and protein amount by Western blot indicated that there are several mechanisms for SPT up-regulation. One of the factors that may account for this complexity is that SPT is also induced by TNF-α, which is secreted by the RAW 264.7 cells after induction by Kdo2-Lipid A. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
|
Plný text