Caspase-2(L), caspase-9, and caspase-3 during in vitro maturation and fragmentation of the mouse oocyte.
Several studies have shown that apoptotic pathways control fragmentation of unfertilized ovulated oocyte, induced by doxorubicin. But very few have investigated the basis of this process, from prophase I to later stages. Our results revealed the presence of caspase-2(L), caspase-9, and caspase-3 in their zymogen and cleaved forms in the oocyte before meiosis resumption. Caspase-2(L) and caspase-9 were detected in the nucleus of GV-oocytes in a distribution related to chromatin configuration. The inhibition of caspase activity by Z-VAD-fmk accelerated the transition from metaphase I to metaphase II, and caspase-9 and caspase-3 were detected along the meiotic spindle. Surprisingly, Western blot analysis revealed that the three cleaved caspases were present in similar amounts in healthy and fragmented oocytes and caspase inhibition did not prevent doxorubicin-induced apoptosis. Our results suggest that, if cleaved, caspases may be dispensable for final oocyte death and they could be involved in regulating the maturation process.
Arnault
Emilie
E
UMR-S 566, CEA, DSV/iRCM/SCSR/LGAG, INSERM, Université Denis Diderot-Paris 7, Université Paris-Sud, Fontenay aux Roses, France.
Tosca
Lucie
L
Courtot
Anne-Marie
AM
Doussau
Mireille
M
Pesty
Arlette
A
Finaz
Catherine
C
Allemand
Isabelle
I
Lefèvre
Brigitte
B
D000590:Amino Acid Chloromethyl Ketones / Q000494:pharmacology; D000595:Amino Acid Sequence; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D053143:Caspase 2 / Q000235:genetics / Q000378:metabolism*; D053148:Caspase 3 / Q000235:genetics / Q000378:metabolism*; D053453:Caspase 9 / Q000235:genetics / Q000378:metabolism*; D061945:Caspase Inhibitors; D002454:Cell Differentiation; D002478:Cells, Cultured; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D007700:Kinetics; D051379:Mice; D009865:Oocytes / Q000166:cytology* / Q000201:enzymology*; D010455:Peptides / Q000737:chemistry / Q000494:pharmacology; D014158:Transcription, Genetic / Q000235:genetics
D000590:Amino Acid Chloromethyl Ketones; D061945:Caspase Inhibitors; D004791:Enzyme Inhibitors; D010455:Peptides; C096713:benzyloxycarbonylvalyl-alanyl-aspartyl fluoromethyl ketone; D053143:Caspase 2; D053148:Caspase 3; D053453:Caspase 9