title: Induction of intracellular ceramide by interleukin-1 beta in oligodendrocytes.
abstract: The sphingomyelin pathway has been implicated in mediating the effect of several extracellular agents leading to important biochemical and cellular changes. The aim of this investigation is to study interleukin-1 beta (IL-1 beta) signaling in oligodendrocytes. For this purpose, the CG4 oligodendrocyte cells were differentiated and incubated with IL-1 beta. This treatment induced a time- and dose-dependent increase of the endocellular ceramide. To mimic the effect of the elevation of endogenous ceramide, the CG4 cells were treated with the ceramide analogue C2-ceramide. Cell survival, measured with the MTT assay, showed that, by increasing the concentration of ceramide, up to 40% of CG4 cells were dying within 6 h, similar data were obtained with the primary differentiated oligodendrocytes. Condensation of chromatin, nuclear fragmentation, and formation of apoptotic bodies indicated that apoptosis was the cause of death. Surprisingly, long-term exposure (72 h) to increasing concentrations of IL-1 beta, which increases intracellular ceramide, did not induce oligodendroglial cell death. These results show that an increase of intracellular ceramide is not sufficient to induce apoptosis in oligodendrocytes and that IL-1 beta signaling through the ceramide pathway in these cells can mediate functions other than programmed cell death.
authors.affiliation: Istituto Biologia Generale Università di Siena, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Brogi
authors.forename: M
authors.initials: M
authors.lastname: Strazza
authors.forename: M
authors.initials: M
authors.lastname: Melli
authors.forename: E
authors.initials: E
authors.lastname: Costantino-Ceccarini
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000502:physiology; D002467:Cell Nucleus / Q000737:chemistry / Q000502:physiology; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D002518:Ceramides / Q000378:metabolism*; D002843:Chromatin / Q000737:chemistry / Q000502:physiology; D004396:Coloring Agents; D004305:Dose-Response Relationship, Drug; D007375:Interleukin-1 / Q000494:pharmacology*; D007424:Intracellular Fluid / Q000737:chemistry; D008722:Methods; D009836:Oligodendroglia / Q000737:chemistry / Q000166:cytology* / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011994:Recombinant Proteins / Q000494:pharmacology; D013109:Sphingomyelins / Q000378:metabolism; D013194:Staining and Labeling; D013778:Tetrazolium Salts / Q000032:analysis; D013844:Thiazoles / Q000032:analysis; D013997:Time Factors
chemical_list: D002518:Ceramides; D002843:Chromatin; D004396:Coloring Agents; D007375:Interleukin-1; D011994:Recombinant Proteins; D013109:Sphingomyelins; D013778:Tetrazolium Salts; D013844:Thiazoles; C065576:ceramide 1-phosphate; C022616:thiazolyl blue