title: Mitochondrial biogenesis and degradation are induced by CCCP treatment of porcine oocytes.
abstract: In this study, we investigated the mitochondrial quality control system in porcine oocytes during meiotic maturation. Cumulus cell oocyte complexes (COCs) collected from gilt ovaries were treated with 10  μM carbonyl cyanide-m-chlorophenylhydrazone (CCCP; a mitochondrial uncoupler) for 2  h. The CCCP treatment was found to significantly reduce ATP content, increase the amount of phosphorylated AMP-activated protein kinase and elevate reactive oxygen species levels in oocytes. When the CCCP-treated COCs were cultured further for 44  h in maturation medium, the ATP levels were restored and the parthenogenetic developmental rate of oocytes to the blastocyst stage was comparable with that of untreated COCs. To examine the effects of CCCP treatment of oocytes on the kinetics of mitochondrial DNA copy number (Mt number), COCs treated with 0 or 10  μM CCCP were cultured for 44  h, after which the Mt number was determined by RT-PCR. CCCP treatment was found to increase the Mt number in the modified maturation medium in which mitochondrial degradation was inhibited by MG132, whereas CCCP treatment did not affect the Mt number in the maturation medium lacking MG132. The relative gene expression of TFAM was furthermore shown to be significantly higher in CCCP-treated oocytes than in untreated oocytes. Taken together, the finding presented here suggest that when the mitochondria are injured, mitochondrial biogenesis and degradation are induced, and that these processes may contribute to the recuperation of oocytes.
authors.affiliation: Department of Animal ReproductionTokyo University of Agriculture, Funako 1737, Atsugi, Kanagawa, 243-0034, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Itami
authors.affiliation: Department of Animal ReproductionTokyo University of Agriculture, Funako 1737, Atsugi, Kanagawa, 243-0034, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Shiratsuki
authors.affiliation: Department of Animal ReproductionTokyo University of Agriculture, Funako 1737, Atsugi, Kanagawa, 243-0034, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Shirasuna
authors.affiliation: Department of Animal ReproductionTokyo University of Agriculture, Funako 1737, Atsugi, Kanagawa, 243-0034, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Kuwayama
authors.affiliation: Department of Animal ReproductionTokyo University of Agriculture, Funako 1737, Atsugi, Kanagawa, 243-0034, Japan h1iwata@nodai.ac.jp.
authors.forename: H
authors.initials: H
authors.lastname: Iwata
mesh_terms: D055372:AMP-Activated Protein Kinases / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone / Q000633:toxicity*; D054885:Cumulus Cells / Q000187:drug effects; D005260:Female; D018628:Gene Dosage; D015870:Gene Expression / Q000187:drug effects; D066298:In Vitro Techniques; D008928:Mitochondria / Q000187:drug effects* / Q000378:metabolism; D009865:Oocytes / Q000187:drug effects*; D001678:Organelle Biogenesis; D010312:Parthenogenesis / Q000187:drug effects; D017382:Reactive Oxygen Species / Q000378:metabolism; D013552:Swine; D014475:Uncoupling Agents / Q000633:toxicity*
chemical_list: D017382:Reactive Oxygen Species; D014475:Uncoupling Agents; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone; D000255:Adenosine Triphosphate; D055372:AMP-Activated Protein Kinases