On the presence of C2-ceramide in mammalian tissues: possible relationship to etherphospholipids and phosphorylation by ceramide kinase

Biol Chem. 2007 Mar;388(3):315-24. doi: 10.1515/BC.2007.035.

Abstract

C(2)-ceramide (N-acetyl-sphingenine) is often used as an analog to study ceramide-mediated cellular processes. According to Lee et al. [J. Biol. Chem. 271 (1996), 209-217], C(2)-ceramide is formed by an acetyl transfer from platelet-activating factor (PAF, 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine) to sphingenine. To substantiate these unconfirmed findings, we (i) developed a method to quantify C(2)-ceramide and (ii) analyzed C(2)-ceramide levels in Pex5(-/-) mice, a model for Zellweger syndrome, in which the synthesis of ether lipids such as PAF is impaired. The presence of C(2)-ceramide could be established in brain (+/-10 pmol/g) and liver (+/-25 pmol/g) from control mice, and was approximately 5000-fold less than the main long-chain ceramide species. In Pex5(-/-) mice, C(2)-ceramide levels did not differ significantly compared to control tissues. Given the presence of a ceramide kinase in mammals, phosphorylation of C(2)-ceramide by human ceramide kinase (HsCERK) was tested. C(2)-ceramide appears to be a good substrate when albumin is used as carrier. In CHO cells overexpressing HsCERK, phosphorylation of exogenously added C(2)-ceramide could also be demonstrated. Our data indicate that C(2)-ceramide is present in mammalian tissues and can be converted to C(2)-ceramide-1-phosphate, in addition to other documented metabolic alterations, but does not seem to be linked to ether lipid metabolism.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • CHO Cells
  • Ceramides / isolation & purification
  • Ceramides / metabolism
  • Cricetinae
  • Cricetulus
  • Mice
  • Phospholipid Ethers / metabolism*
  • Phosphorylation
  • Phosphotransferases (Alcohol Group Acceptor) / metabolism*
  • Platelet Activating Factor / metabolism
  • Sphingosine / analogs & derivatives*
  • Sphingosine / analysis
  • Sphingosine / metabolism

Substances

  • Ceramides
  • N-acetylsphingosine
  • Phospholipid Ethers
  • Platelet Activating Factor
  • ceramide 1-phosphate
  • Phosphotransferases (Alcohol Group Acceptor)
  • ceramide kinase
  • Sphingosine