Sphingosylphosphorylcholine induces mitochondria-mediated apoptosis in neuro 2a cells: involvement of protein kinase C.
We demonstrate that sphingosylphosphorylcholine-mediated cell death involves the activation of different protein kinase C isozymes in different manners. Treating cells with sphingosylphosphorylcholine resulted in activation of protein kinase C delta, which is necessary, together with elevation of Ca2+ for sphingosylphosphorylcholine-induced apoptosis. A rapid translocation from cytosol to membrane, and a proteolytic protein kinase C delta cleavage was found, probably due to activation of caspase-3, to give a catalytically active fragment involved in cellular apoptosis. Moreover, sphingosylphosphorylcholine also induced translocation of protein kinase C zeta, resulting in an anti-apoptotic effect. To explore whether a mitochondrial pathway is involved in sphingosylphosphorylcholine-induced apoptosis, we analyzed the effect of sphingosylphosphorylcholine on cytochrome c release and caspase-3 activity. We must point out that the sphingolipid caused an increase of cytochrome c release from mitochondria to cytosol concomitantly with an increase of caspase-3 activity. Furthermore, a translocation of Bax was found, after sphingosylphosphorylcholine treatment.
Miguel
Begońa G
BG
Departamento de Bioquímica y Biología Molecular I, Facultad de Química, Universidad Complutense de Madrid, 28040 Madrid, Spain.
Fernández
Inmaculada
I
Toboso
Inmaculada
I
Agudo-López
Alba
A
Catalán
Edgardo
E
Martínez
Ana M
AM
D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D053148:Caspase 3 / Q000378:metabolism; D002460:Cell Line; D053938:DNA Fragmentation / Q000187:drug effects; D005434:Flow Cytometry; D007527:Isoenzymes / Q000502:physiology; D051379:Mice; D008928:Mitochondria / Q000187:drug effects* / Q000201:enzymology; D009474:Neurons / Q000187:drug effects* / Q000201:enzymology; D010767:Phosphorylcholine / Q000031:analogs & derivatives* / Q000494:pharmacology; D011493:Protein Kinase C / Q000502:physiology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000502:physiology; D013110:Sphingosine / Q000031:analogs & derivatives* / Q000494:pharmacology; D013347:Subcellular Fractions / Q000378:metabolism
D007527:Isoenzymes; C005356:sphingosine phosphorylcholine; D010767:Phosphorylcholine; D011493:Protein Kinase C; D053148:Caspase 3; D013110:Sphingosine