Insulin-like growth factor I promotes oocyte maturation through increasing the expression and phosphorylation of epidermal growth factor receptor in the zebrafish ovary
Insulin-like growth factor I promotes oocyte maturation through increasing the expression and phosphorylation of epidermal growth factor receptor in the zebrafish ovary
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DOI：
10.1016/j.mce.2015.10.018
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发表时间：
2016-01-05
影响因子：
4.1
通讯作者：
Chen, Lianyi
中科院分区：
文献类型：
--
作者：
Xie, Lin;Tang, Qiongyan;Chen, Lianyi
卵母细胞减数分裂的恢复是卵母细胞发育的关键步骤，需要多种激素和生长因子的密切配合。胰岛素样生长因子I（IGF-I）和表皮生长因子（EGF）家族被公认为促进卵母细胞成熟。然而，它们协调这一进程的机制仍不清楚。本研究表明，IGF-I可以增加卵泡细胞培养或完整卵泡中EGFR mRNA和蛋白水平。IGF-IR特异性抑制剂NVP-ADW 742可显著抑制这种刺激。对磷脂酰肌醇1 -3-激酶（PI 3 K），磷酸肌醇依赖性蛋白激酶1（PDK 1）和Akt的抑制剂也显着消除IGF-I诱导的EGFR的表达，表明经典的PI 3 K/Akt途径介导的IGF-I在这种调节的作用。我们进一步发现IGF-I不仅使Egfr的蛋白水平增加，而且使其磷酸化水平增强。与EGFR不同，IGF-I未能刺激EGF样配体的表达，而降低了蛋白酪氨酸磷酸酶，受体类型，κ（ptprk），一种蛋白酪氨酸磷酸酶的水平。卵母细胞成熟试验进一步证实IGF-I通过卵泡细胞中的同源受体启动这种调节。总之，IGF-I促进卵母细胞成熟，至少部分地，通过Egf-like ligands/Egfr途径。本研究揭示了斑马鱼卵巢中两种重要生长因子之间的相互作用以及IGF-I诱导卵母细胞成熟的机制。(C)2015爱思唯尔爱尔兰有限公司版权所有。
The resumption of oocyte meiosis is a critical step for the progression of oocyte development, which requires an intimate collaboration of a variety of hormones and growth factors. Insulin-like growth factor I (IGF-I) and epidermal growth factor (EGF) family are well recognized to promote oocyte maturation. However, the mechanism by which they coordinate this process remains unknown. The present study demonstrated that IGF-I can increase egfr mRNA and protein levels in follicle cell culture or intact follicles. This stimulation can be significantly inhibited by IGF-IR specific inhibitor, NVP-ADW742. The inhibitors against phosphatidylinosito1-3-kinase (PI3K), phosphoinositide-dependent protein kinase 1 (PDK1) and Akt also dramatically abolished IGF-I-induced egfr expression, suggesting that the classical PI3K/Akt pathway mediated the action of IGF-I in this regulation. We further found that not only was the protein level of Egfr increased, but also the phosphorylation level was enhanced by IGF-I. Unlike egfr, IGF-I failed to stimulate the expression of Egf-like ligands whereas decreased the level of protein-tyrosine phosphatase, receptor type, kappa (ptprk), a protein tyrosine phosphatase. The oocyte maturation assay further confirmed that IGF-I initiates this regulation through its cognate receptor in the follicle cells. Taken together, IGF-I promoted oocyte maturation, in part at least, through Egf-like ligands/Egfr pathway. This study sheds light on the cross-talk between two important growth factors in the zebrafish ovary and the mechanism underlying the IGF-I induction on oocyte maturation. (C) 2015 Elsevier Ireland Ltd. All rights reserved.