title: Mitochondrial peroxiredoxin-5 as potential modulator of mitochondria-ER crosstalk in MPP+-induced cell death.
abstract: Peroxiredoxin-5 (PRDX5) is an antioxidant enzyme which differs from the other peroxiredoxins with regards to its enzymatic mechanism, its high affinity for organic peroxides and peroxynitrite and its wide subcellular distribution. In particular, the mitochondrial isoform of PRDX5 confers a remarkable cytoprotection toward oxidative stress to mammalian cells. Mitochondrial dysfunction and disruption of Ca²⁺ homeostasis are implicated in neurodegeneration. Growing evidence supports that endoplasmic reticulum (ER) could operate in tandem with mitochondria to regulate intracellular Ca²⁺ fluxes in neurodegenerative processes. Here, we overexpressed mitochondrial PRDX5 in SH-SY5Y cells to dissect the role of this enzyme in 1-methyl-4-phenylpyridinium (MPP)⁺-induced cell death. Our data show that mitochondria-dependent apoptosis triggered by MPP⁺, assessed by the measurement of caspase-9 activation and mitochondrial DNA damage, is prevented by mitochondrial PRDX5 overexpression. Moreover, PRDX5 overexpression blocks the increase in intracellular Ca²⁺, Ca²⁺-dependent activation of calpains and Bax cleavage. Finally, using Ca²⁺ channel inhibitors (Nimodipine, Dantrolene and 2-APB), we show that Ca²⁺ release arises essentially from ER stores through 1,4,5-inositol-trisphosphate receptors (IP3 R). Altogether, our results suggest that the MPP⁺ mitochondrial pathway of apoptosis is regulated by mitochondrial PRDX5 in a process that could involve redox modulation of Ca²⁺ transporters via a crosstalk between mitochondria and ER.
authors.affiliation: Group of Cell Biology, Institut des Sciences de la Vie, Université catholique de Louvain, Louvain-la-Neuve, Belgium.
authors.forename: Stéphanie
authors.initials: S
authors.lastname: De Simoni
authors.forename: Dominique
authors.initials: D
authors.lastname: Linard
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Hermans
authors.forename: Bernard
authors.initials: B
authors.lastname: Knoops
authors.forename: Julie
authors.initials: J
authors.lastname: Goemaere
mesh_terms: D015632:1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine / Q000494:pharmacology*; D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D001896:Boron Compounds / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D002154:Calpain / Q000378:metabolism; D053148:Caspase 3 / Q000378:metabolism; D053453:Caspase 9 / Q000378:metabolism; D045744:Cell Line, Tumor; D004272:DNA, Mitochondrial / Q000235:genetics / Q000378:metabolism; D015259:Dopamine Agents / Q000494:pharmacology*; D004721:Endoplasmic Reticulum / Q000187:drug effects / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects / Q000235:genetics; D006801:Humans; D006836:Hydro-Lyases / Q000378:metabolism; D051379:Mice; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism*; D009447:Neuroblastoma / Q000473:pathology; D054464:Peroxiredoxins / Q000235:genetics / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D013347:Subcellular Fractions / Q000187:drug effects / Q000378:metabolism; D014162:Transfection; D014443:Tyrosine / Q000031:analogs & derivatives / Q000378:metabolism
chemical_list: D001896:Boron Compounds; D004272:DNA, Mitochondrial; D015259:Dopamine Agents; D004791:Enzyme Inhibitors; D034741:RNA, Small Interfering; D017382:Reactive Oxygen Species; C002744:3-nitrotyrosine; D014443:Tyrosine; D000255:Adenosine Triphosphate; D015632:1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine; C109986:2-aminoethoxydiphenyl borate; C515974:PRDX5 protein, human; D054464:Peroxiredoxins; D002154:Calpain; D053148:Caspase 3; D053453:Caspase 9; D006836:Hydro-Lyases; C045581:lactate dehydratase; D002118:Calcium