6-Hydroxydopamine (6-OHDA) induces Drp1-dependent mitochondrial fragmentation in SH-SY5Y cells.
Mitochondrial alterations have been associated with the cytotoxic effect of 6-hydroxydopamine (6-OHDA), a widely used neurotoxin to study Parkinson's disease. Herein we studied the potential effects of 6-OHDA on mitochondrial morphology in SH-SY5Y neuroblastoma cells. By immunofluorescence and time-lapse fluorescence microscopy we demonstrated that 6-OHDA induced profound mitochondrial fragmentation in SH-SY5Y cells, an event that was similar to mitochondrial fission induced by overexpression of Fis1p, a membrane adaptor for the dynamin-related protein 1 (DLP1/Drp1). 6-OHDA failed to induce any changes in peroxisome morphology. Biochemical experiments revealed that 6-OHDA-induced mitochondrial fragmentation is an early event preceding the collapse of the mitochondrial membrane potential and cytochrome c release in SH-SY5Y cells. Silencing of DLP1/Drp1, which is involved in mitochondrial and peroxisomal fission, prevented 6-OHDA-induced fragmentation of mitochondria. Furthermore, in cells silenced for Drp1, 6-OHDA-induced cell death was reduced, indicating that a block in mitochondrial fission protects SH-SY5Y cells against 6-OHDA toxicity. Experiments in mouse embryonic fibroblasts deficient in Bax or p53 revealed that both proteins are not essential for 6-OHDA-induced mitochondrial fragmentation. Our data demonstrate for the first time an involvement of mitochondrial fragmentation and Drp1 function in 6-OHDA-induced apoptosis.
Gomez-Lazaro
Maria
M
Grupo de Neurofarmacología, Department Ciencias Médicas, Facultad de Medicina, Universidad de Castilla-La Mancha-Centro Regional de Investigaciones Biomédicas, Albacete, Spain.
Bonekamp
Nina A
NA
Galindo
Maria F
MF
Jordán
Joaquin
J
Schrader
Michael
M
D000818:Animals; D017209:Apoptosis / Q000187:drug effects* / Q000502:physiology; D045744:Cell Line, Tumor; D045304:Cytochromes c / Q000378:metabolism; D034281:Dynamins; D004622:Embryo, Mammalian / Q000187:drug effects / Q000378:metabolism; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D020558:GTP Phosphohydrolases / Q000378:metabolism*; D006801:Humans; D006892:Hydroxydopamines / Q000494:pharmacology*; D053078:Membrane Potential, Mitochondrial; D051379:Mice; D018345:Mice, Knockout; D008869:Microtubule-Associated Proteins / Q000378:metabolism*; D008928:Mitochondria / Q000378:metabolism*; D024101:Mitochondrial Proteins / Q000378:metabolism*; D009447:Neuroblastoma / Q000378:metabolism* / Q000473:pathology; D016159:Tumor Suppressor Protein p53 / Q000502:physiology; D051028:bcl-2-Associated X Protein / Q000502:physiology
C494827:Bax protein, mouse; D006892:Hydroxydopamines; D008869:Microtubule-Associated Proteins; D024101:Mitochondrial Proteins; D016159:Tumor Suppressor Protein p53; D051028:bcl-2-Associated X Protein; D045304:Cytochromes c; D020558:GTP Phosphohydrolases; C110768:DNM1L protein, human; D034281:Dynamins