Stress stimulates AMP-Activated protein kinase and meiotic resumption in mouse oocytes
Stress stimulates AMP-Activated protein kinase and meiotic resumption in mouse oocytes
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DOI：
10.1095/biolreprod.105.046524
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发表时间：
2006-03-01
影响因子：
3.6
通讯作者：
Downs, SM
中科院分区：
文献类型：
--
作者：
LaRosa, C;Downs, SM
本研究考察了三种不同的细胞应激对减数分裂阻滞小鼠卵母细胞成熟的影响。将未成熟小鼠的卵母细胞卵母细胞（CEO）或剥去卵母细胞（DO）在含有dbcamp的培养基中培养17-18小时，并增加代谢毒物亚砷酸钠或自由基生成剂甲萘醌的浓度。或者，卵母细胞通过山梨醇脉冲暴露于渗透胁迫下，并在培养期间恢复到控制抑制条件。亚砷酸盐和甲萘酮剂量依赖性诱导DO和CEO的生发囊泡破裂（GVB）。用500 mM山梨醇刺激DO（而不是CEO）脉冲60分钟以恢复成熟。在CEO中缺乏作用表明，积云细胞可能在渗透应激诱导的GVB中起保护作用。amp激活的蛋白激酶（PRKA，以前称为AMPK）抑制剂，化合物C和araA，完全阻断了所有测试应激的减数分裂刺激作用。Western blot结果显示，PRKA的重要底物乙酰辅酶a羧化酶在GVB前被磷酸化，支持PRKA在应激诱导成熟中的作用。总之，这些数据表明，在体外，多种应激刺激减数分裂阻滞的小鼠卵母细胞中的GVB，并表明这种作用是通过激活PRKA介导的。
This study examined the effects of three different cellular stresses on oocyte maturation in meiotically arrested mouse oocytes. Cumulus-cell enclosed oocytes (CEO) or denuded oocytes (DO) from immature, eCG-primed mice were cultured for 17-18 h in dbcAMP-containing medium plus increasing concentrations of the metabolic poison, sodium arsenite, or the free radical-generating agent, menadione. Alternatively, oocytes were exposed to osmotic stress by pulsing with sorbitol and returned to control inhibitory conditions for the duration of culture. Arsenite and menadione each dose-dependently induced germinal vesicle breakdown (GVB) in both DO and CEO. DO, but not CEO, pulsed for 60 min with 500 mM sorbitol were stimulated to resume maturation. The lack of effect in CEO suggests that the cumulus cells may be playing a protective role in osmotic stress-induced GVB. The AMP-activated protein kinase (PRKA; formerly known as AMPK) inhibitors, compound C and araA, completely blocked the meiosis-stimulating effects of all the tested stresses. Western blots showed that acetyl-CoA carboxylase, an important substrate of PRKA, was phosphorylated before GVB, supporting a role for PRKA in stress-induced maturation. Together, these data show that a variety of stresses stimulate GVB in meiotically arrested mouse oocytes in vitro and suggest that this effect is mediated through activation of PRKA.