Effects of adenosine monophosphate-activated kinase activators on bovine oocyte nuclear maturation in vitro
Effects of adenosine monophosphate-activated kinase activators on bovine oocyte nuclear maturation in vitro
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DOI：
10.1002/mrd.20574
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发表时间：
2007-08-01
影响因子：
2.5
通讯作者：
Richard, Francois J.
中科院分区：
文献类型：
--
作者：
Bilodeau-Goeseels, Sylvie;Sasseville, Maxime;Richard, Francois J.
本研究的目的是检测 AMPK 激活剂（5-氨基咪唑-4-甲酰胺 1-β-D-呋喃核苷 (AICAR)）对体外牛卵母细胞核成熟的影响。培养 7 小时后，AICAR (1 mM) 显着增加了保留在生发囊阶段的卵丘封闭卵母细胞 (CEO) 和裸露卵母细胞 (DO) 的百分比。培养 22 小时后，AICAR 显着降低了达到中期 II (MII) 的 CEO 百分比。 1.0 mM 的 AICAR 还增强了腺苷酸环化酶激活剂毛喉素对 CEO 的抑制作用；然而，与单独使用毛喉素相比，0.05 mM 的 AICAR 在培养 22 小时后增加了 MII 卵母细胞的百分比。腺苷激酶抑制剂 5'-氨基脱氧腺苷逆转了 AICAR 在 CEO 和 DO 中的作用，表明腺苷激酶对 AICAR 的磷酸化是其抑制活性所必需的。 GMP（而非 AMP）抑制 CEO 和 DO 的减数分裂；然而，鸟苷酸和腺苷酸合成的抑制并没有逆转 AICAR 的作用，这表明 AICAR 的抑制作用不是由于这些核苷酸的合成增加所致。另一种 AMPK 激活剂二甲双胍也能抑制 CEO 和 DO 的 GVBD。在卵母细胞和卵母细胞中检测到 AMPK 催化亚基的 α-1 异构体，逆转录聚合酶链反应实验表明卵母细胞和卵母细胞中存在调节亚基的 α-1、α-2、β-1 和 γ-3 异构体的转录本。这些数据表明，AMPK 激活剂 AICAR 由于 AMPK 的激活而抑制牛卵母细胞的核成熟。
The purpose of this study was to examine the effects of an activator of AMPK (5-aminoimidazole-4-carboxamide 1-beta-D-ribofuranoside (AICAR)) on bovine oocyte nuclear maturation in vitro. After 7 hr of culture, AICAR (1 mM) significantly increased the percentages of cumulus-enclosed oocytes (CEO) and denuded oocytes (DO) remaining at the germinal vesicle stage. After 22 hr of culture, AICAR significantly reduced the percentage of CEO reaching metaphase II (MII). AICAR at 1.0 mM also increased the inhibitory effect of the adenylate cyclase activator forskolin in CEO; however, at 0.05 mM, AICAR increased the percentage of oocytes at MII after 22 hr of culture compared to forskolin alone. The adenosine kinase inhibitor 5'-aminodeoxyadenosine reversed the effect of AICAR in CEO and DO showing that phosphorylation of AICAR by adenosine kinase is required for its inhibitory activity. GMP, but not AMP, inhibited meiosis in CEO and DO; however, inhibition of guanyl and adenyl nucleotides synthesis did not reverse the effect of AICAR suggesting that the inhibitory effect of AICAR is not due to increased synthesis of these nucleotides. Metformin, another activator of AMPK, also inhibited GVBD in CEO and DO. The alpha-1 isoform of the catalytic subunit of AMPK was detected in oocytes and cumulus cells, and reverse transcription-polymerase chain reaction experiments showed the presence of transcripts for alpha-1, alpha-2, beta-1, and gamma-3 isoforms of the regulatory subunits in cumulus cells and oocytes. These data show that the AMPK activator AICAR is inhibitory to nuclear maturation in bovine oocytes due to activation of AMPK.