Pyruvate prevents aging of mouse oocytes.
Inhibiting oocyte aging is important not only for healthy reproduction but also for the success of assisted reproduction techniques. Although our previous studies showed that cumulus cells accelerated aging of mouse oocytes, the underlying mechanism is unknown. The objective of this paper was to study the effects of pyruvate and cumulus cells on mouse oocyte aging. Freshly ovulated mouse cumulus-oocyte complexes (COCs) or cumulus-denuded oocytes (DOs) were cultured in Chatot-Ziomek-Bavister (CZB) medium or COC-conditioned CZB medium supplemented with different concentrations of pyruvate before being examined for aging signs and developmental potential. Pyruvate supplementation to CZB medium decreased rates of ethanol-induced activation in both COCs and DOs by maintaining their maturation-promoting factor activities, but more pyruvate was needed for COCs than for DOs. Addition of pyruvate to the COC-conditioned CZB also alleviated aging of DOs. Observations on cortical granules, level of BCL2 proteins, histone acetylation, intracellular concentration of glutathione, and embryo development all confirmed that pyruvate supplementation inhibited aging of mouse oocytes. It is concluded that the aging of mouse oocytes, facilitated by culture in COCs, can be partially prevented by the addition of pyruvate to the culture medium.
Liu
Na
N
Laboratory for Animal Reproduction and Embryology, College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Tai-An City, Shandong Province, PR China.
Wu
Yan-Guang
YG
Lan
Guo-Cheng
GC
Sui
Hong-Shu
HS
Ge
Li
L
Wang
Jun-Zuo
JZ
Liu
Yong
Y
Qiao
Tian-Wu
TW
Tan
Jing-He
JH
D000107:Acetylation; D000818:Animals; D015415:Biomarkers / Q000032:analysis; D018929:Cell Culture Techniques; D002478:Cells, Cultured; D016922:Cellular Senescence / Q000187:drug effects; D017077:Culture Media, Conditioned; D054885:Cumulus Cells / Q000166:cytology* / Q000187:drug effects; D005260:Female; D005307:Fertilization in Vitro; D005978:Glutathione / Q000032:analysis / Q000378:metabolism; D006657:Histones / Q000032:analysis / Q000378:metabolism; D016200:Maturation-Promoting Factor / Q000032:analysis / Q000378:metabolism; D051379:Mice; D008815:Mice, Inbred Strains; D018613:Microscopy, Confocal; D009865:Oocytes / Q000187:drug effects / Q000502:physiology*; D011518:Proto-Oncogene Proteins / Q000032:analysis / Q000378:metabolism; D019253:Proto-Oncogene Proteins c-bcl-2; D019289:Pyruvic Acid / Q000494:pharmacology*
D015415:Biomarkers; D017077:Culture Media, Conditioned; D006657:Histones; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; C052617:Bcl2 protein, mouse; D019289:Pyruvic Acid; D016200:Maturation-Promoting Factor; D005978:Glutathione