Regulation of GVBD in mouse oocytes by miR-125a-3p and Fyn kinase through modulation of actin filaments.
Regulation of GVBD in mouse oocytes by miR-125a-3p and Fyn kinase through modulation of actin filaments.
复制标题
DOI：
10.1038/s41598-017-02071-x
复制
发表时间：
2017-05-22
影响因子：
4.6
通讯作者：
Shalgi R
中科院分区：
文献类型：
--
作者：
Grossman H;Har-Paz E;Gindi N;Levi M;Miller I;Nevo N;Galiani D;Dekel N;Shalgi R
减数分裂停止的卵母细胞的特征是存在称为生发囊泡（GV）的核结构，其破裂（GVBD）与减数分裂的恢复有关。Fyn是恢复第一次减数分裂的关键因素；其抑制作用显著降低了发生GVBD的卵母细胞的比例。在这里，我们发现在小鼠卵母细胞中，Fyn受miR-125a-3p的转录后调控。我们证明，在恢复减数分裂的卵母细胞中，miR-125a-3p和Fyn表现出相互的表达模式；miR-125a-3p随着Fyn表达的增加而降低。微量注射miR-125a-3p抑制GVBD，这种作用因Fyn过表达而明显减弱，并损害核周围肌动蛋白边缘的组织。暴露于细胞松弛素d或blebbistatin的卵母细胞中，GVBD的发生率也较低，这两种物质分别干扰肌动蛋白的聚合和肌动蛋白束的收缩。miR-125a-3p通过下调HEK-293T细胞中的Fyn，降低了肌动蛋白与构成核层的a型层蛋白之间的相互作用。我们的研究结果提示了一种机制，即在卵母细胞成熟过程中miR-125a-3p的减少通过允许Fyn上调以及由此导致的肌动蛋白和a型层蛋白之间相互作用的稳定来促进GVBD。
Meiotically arrested oocytes are characterized by the presence of the nuclear structure known as germinal-vesicle (GV), the breakdown of which (GVBD) is associated with resumption of meiosis. Fyn is a pivotal factor in resumption of the first meiotic division; its inhibition markedly decreases the fraction of oocytes undergoing GVBD. Here, we reveal that in mouse oocytes Fyn is post-transcriptionally regulated by miR-125a-3p. We demonstrate that in oocytes resuming meiosis miR-125a-3p and Fyn exhibit a reciprocal expression pattern; miR-125a-3p decreases alongside with an increase in Fyn expression. Microinjection of miR-125a-3p inhibits GVBD, an effect that is markedly reduced by Fyn over-expression, and impairs the organization of the actin rim surrounding the nucleus. Lower rate of GVBD is also observed in oocytes exposed to cytochalasin-D or blebbistatin, which interfere with actin polymerization and contractility of actin bundles, respectively. By down-regulating Fyn in HEK-293T cells, miR-125a-3p reduces the interaction between actin and A-type lamins, which constitute the nuclear-lamina. Our findings suggest a mechanism, by which a decrease in miR-125a-3p during oocyte maturation facilitates GVBD by allowing Fyn up-regulation and the resulting stabilization of the interaction between actin and A-type lamins.