Participation of PI3-kinase/Akt signalling in insulin stimulation of p34cdc2 activation in zebrafish oocyte: Phosphodiesterase 3 as a potential downstream target
Participation of PI3-kinase/Akt signalling in insulin stimulation of p34cdc2 activation in zebrafish oocyte: Phosphodiesterase 3 as a potential downstream target
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DOI：
10.1016/j.mce.2013.04.007
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发表时间：
2013-07-15
影响因子：
4.1
通讯作者：
Maitra, Sudipta
中科院分区：
文献类型：
--
作者：
Das, Debabrata;Khan, Pragya Paramita;Maitra, Sudipta
将完全生长的卵母细胞暴露于生长因子（胰岛素/IGFs）启动各种信号传导级联，最终达到卵母细胞成熟的最后阶段。在生长因子诱导的减数分裂恢复鱼类的信号通路的调节还没有得到很好的表征。研究了PI 3 K/Akt信号通路在重组人胰岛素（rh-insulin）诱导斑马鱼（Danio rerio）卵母细胞减数分裂成熟过程中的作用。在体外用rh-insulin引发去卵泡卵母细胞以剂量和时间依赖的方式促进生殖囊泡破裂（GVBD），这种效应对翻译敏感，但对转录抑制不敏感。超过80%的卵母细胞经历GVBD由于0.8 IU/ml的rh-insulin孵育10小时内和p34 cdc 2激酶激活的动力学与GVBD数据相对应。PI 3 K抑制剂渥曼青霉素和LY 294002阻断胰岛素，但不能阻断17 α，20 β-DHP诱导的GVBD。卵母细胞提取物的免疫印迹分析显示，磷酸-PI 3 K（p85 α）上调胰岛素刺激后，磷酸-Akt（Ser 473）在60-120分钟内。虽然PI 3 K/Akt磷酸化在很大程度上不受影响，预孵育磷酸二酯酶（PDE）抑制剂，IBMX和西洛酰胺，但不是咯利普兰完全阻断了rh-insulin诱导的p34 cdc 2激活和GVBD。这些结果表明，PDE 3可能是一个潜在的下游目标，PI 3 K/Akt信号所必需的rh-insulin诱导的GVBD在斑马鱼。(c)2013爱思唯尔爱尔兰有限公司版权所有。
Exposure of fully grown oocytes to growth factors (insulin/IGFs) initiates various signalling cascades that culminate to final stages of oocyte maturation. Regulation of signalling pathways during growth factor-induced meiosis resumption in fish is not well characterized. Here we studied the participation of PI3K/Akt signalling pathway during recombinant human insulin (rh-insulin)-induced meiotic maturation in zebrafish (Danio rerio) oocytes. Priming of defolliculated oocytes in vitro with rh-insulin promotes germinal vesicle breakdown (GVBD) in a dose- and time-dependent manner, an effect sensitive to translation but not transcription inhibition. More than 80% of the oocytes underwent GVBD due to 0.8 IU/ml rh-insulin within 10 h of incubation and the kinetics of p34cdc2 kinase activation corresponded well with GVBD data. PI3K inhibitors, wortmannin and LY294002 blocked insulin, but not 17 alpha, 20 beta-DHP-induced GVBD. Immunoblot analyses of oocyte extract revealed that phospho-PI3K (p85 alpha) was up regulated within 30-60 min of insulin stimulation followed by phospho-Akt (Ser473) at 60-120 min. Though PI3K/Akt phosphorylation was largely unaffected, pre-incubation with phosphodiesterase (PDE) inhibitors, IBMX and cilostamide, but not rolipram completely blocked rh-insulin-induced p34cdc2 activation and GVBD. These results suggest that PDE3 may be one potential downstream target to PI3K/Akt signalling necessary for rh-insulin-induced GVBD in zebrafish. (c) 2013 Elsevier Ireland Ltd. All rights reserved.