GD3 ganglioside directly targets mitochondria in a bcl-2-controlled fashion

Maria Rita Rippo, Florence Malisan, Luigi Ravagnan, Barbara Tomassini, Ivano Condo, Paola Costantini, Santos A. Susin, Alessandra Rufini, Matilde Todaro, Guido Kroemer, Roberto Testi

Résultats de recherche: Contribution à un journalArticleRevue par des pairs

172 Citations (Scopus)

Résumé

Lipid and glycolipid diffusible mediators are involved in the intracellular progression and amplification of apoptotic signals. GD3 ganglioside is rapidly synthesized from accumulated ceramide after the clustering of death-inducing receptors and triggers apoptosis. Here we show that GD3 induces dissipation of ΔΨ(m) and swelling of isolated mitochondria, which results in the mitochondrial release of cytochrome c, apoptosis inducing factor, and caspase 9. Soluble factors released from GD3-treated mitochondria are sufficient to trigger DNA fragmentation in isolated nuclei. All these effects can be blocked by cyclosporin A, suggesting that GD3 is acting at the level of the permeability transition pore complex. We found that endogenous GD3 accumulates within mitochondria of cells undergoing apoptosis after ceramide exposure. Accordingly, suppression of GD3 synthase (ST8) expression in intact cells substantially prevents ceramide-induced ΔΨ(m) dissipation, indicating that endogenously synthesized GD3 induces mitochondrial changes in vivo. Finally, enforced expression of bcl-2 significantly prevents GD3-induced mitochondrial changes, caspase 9 activation, and apoptosis. These results show that mitochondria are a key destination for apoptogenic GD3 ganglioside along the lipid pathway to programmed cell death and indicate that relevant GD3 targets are under bcl-2 control.

langue originaleAnglais
Pages (de - à)2047-2054
Nombre de pages8
journalFASEB Journal
Volume14
Numéro de publication13
Les DOIs
étatPublié - 1 janv. 2000
Modification externeOui

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