Ceramide and sphingomyelin species of fibroblasts and neurons in culture.
The ceramide (Cer) and sphingomyelin (SM) species of cultured differentiated rat cerebellar granule cells and human fibroblasts were characterized by electrospray ionization-mass spectrometry. We identified 35 different species of Cer and 18 species of SM in human fibroblasts, and 35 different species of Cer and 9 species of SM were characterized in rat neurons. The main Cer species of rat cerebellar granule cells contained d18:1 sphingosine linked with palmitic, stearic, or nervonic fatty acid, and the two main SM species were d18:1,16:0 and d18:1,18:0. Both sphingolipids were enriched in detergent-resistant membranes (DRMs; or lipid rafts), and significant differences were found in the sphingolipid patterns of DRMs and of detergent-soluble fractions (DSF) from these cells. In human fibroblasts, the main Cer species were d18:1,16:0, d18:2,16:0, d18:1,24:0, d18:2,24:0, d18:1,24:1, and d18:2,24:1; the most represented species of SM were d18:1,16:0, d18:1,24:0, and d18:1,24:1. In these cells, SM was highly enriched in DRMs and Cer was mainly associated with DSF, and the species found in DRMs were markedly different from those found in DSF.
Valsecchi
Manuela
M
Department of Medical Chemistry, Biochemistry, and Biotechnology, Center of Excellence on Neurodegenerative Diseases, University of Milan, 20090 Segrate, Italy.
Mauri
Laura
L
Casellato
Riccardo
R
Prioni
Simona
S
Loberto
Nicoletta
N
Prinetti
Alessandro
A
Chigorno
Vanna
V
Sonnino
Sandro
S
D000818:Animals; D002478:Cells, Cultured; D002518:Ceramides / Q000032:analysis* / Q000737:chemistry; D005347:Fibroblasts / Q000737:chemistry*; D006801:Humans; D013058:Mass Spectrometry; D015394:Molecular Structure; D009474:Neurons / Q000737:chemistry*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012867:Skin / Q000166:cytology; D013045:Species Specificity; D013109:Sphingomyelins / Q000032:analysis* / Q000737:chemistry
D002518:Ceramides; D013109:Sphingomyelins