Aurora激酶是肿瘤研究领域的热点,近年来有研究表明该激酶家族在卵母细胞减数分裂中也起着重要的调节作用,但对于其在哺乳动物早期胚胎发育中的研究鲜有报道.本研究通过实时荧光定量PCR、免疫印迹、免疫荧光检测了Aurora激酶B(Aurora kinaseB,AURKB)在小鼠受精卵中的表达和定位,运用RNA干扰技术观察了AURKB功能缺失后对小鼠受精卵发育早期的影响,并检测丝裂原激活蛋白激酶(mitogen-activated protein kinase,MAPK)通路抑制后小鼠受精卵卵裂及AURKB表达、活性变化.结果表明,在小鼠受精卵第一次卵裂进程中,G2/M期为AURKB的稳定表达时相,其蛋白在G1/S期少量分布于细胞浆,G2期聚集于染色质周围,进入有丝分裂后分布于全细胞.AURKB的功能缺失可导致受精卵发生异常分裂.MAPK通路的抑制亦可破坏受精卵的正常卵裂,并下调AURKB的蛋白表达及活性.结果提示,Aurora激酶B是小鼠受精卵早期发育所必需的,并与MAPK通路的激活相关.
Aurora激酶是参与细胞周期调节的重要激酶,已成为肿瘤研究领域的热点.近年来有研究表明,Aurora激酶A(Aurora kinase A,AURKA)对卵母细胞减数分裂也起到重要的调节作用,但对其在哺乳动物早期胚胎发育中的研究鲜有报道.本研究利用显微注射向受精卵中导入干扰AURKA表达的质粒,观察了AURKA表达敲低对小鼠受精卵早期发育的影响,并检测丝裂原活化蛋白激酶(mitogen-activated protein kinase,MAPK)通路抑制后,小鼠受精卵卵裂及AURKA表达与活性变化.实验结果表明,干扰AURKA的表达可导致受精卵发育停滞和异常分裂.MAPK通路的抑制亦可破坏受精卵正常卵裂,并下调AURKA的蛋白表达及活性.实验结果提示,AURKA是小鼠受精卵早期发育所必需的,并与MAPK通路的激活相关.
Aurora kinases have become a hot topic for research as they have been found to play an important role in various stages of mitotic cell division and to participate in malignant conversions of tumors. The participation of Aurora kinases in the regulation of oocyte meiosis has been recently reported, but their participation in mammalian early embryonic development remained unclear. The object of our study was to establish the spatio-temporal expression pattern of Aurora kinase B (AURKB) in mouse zygotes during the first cleavage, to reveal its functions in the early development of mouse zygotes, and to define the involvement of AURKB in mitogen-activated protein kinase (MAPK) signaling. Our results showed that in mouse zygotes AURKB expression increased in G1 phase and peaked in M phase. AURKB protein distribution was found to be in association with nuclei and distributed throughout the cytoplasm in a cell cycle-dependent manner. Functional disruption of AURKB resulted in abnormal division phenotypes or mitotic impairments. U0126, a specific mitogen-activated protein kinase kinase (MEK) inhibitor, caused significantly altered morphologies of early embryos together with a decrease in protein expression and kinase activity of AURKB. Our results indicated that the activity of AURKB was required for regulating multiple stages of mitotic progression in the early development of mouse zygotes and was correlated with the activation of the MAPK pathway.
XU LinLIU TongHAN FengZONG ZhiHongWANG GuoLiYU BingZhiZHANG Jie
Objective To investigate the expression and localization of Aurora kinase A （A URKA ） and Aurora kinase B （A URKB） in mouse zygotes during the process of the first mitosis. Methods Quantitative real-time RT-PCR and Western blotting were performed to analyze the expression of AURKA and AURKB. The subcellular location of AURKA and A URKB was studied by confocal microscopy. Results A URKA and A URKB were increasingly expressed from phase G1 and peaked at phase M. After the entrance into mitosis A URKB became the predominant form both in mRNA and protein levels. The proteins of A URKA and A URKB both distributed in the cytoplasm and were associated with nucleus during the first mitosis of mouse zygotes, with some details in different. Conclusion The expression and localization of Aurora kinases A and B was in a cell- cycle regulated manner during the process of the cleavage of mouse zygotes. This discovery will aid in future investigations on their specific roles and molecular mecha- nisms in the regulation of mammalian early embryonic development.
Jie ZHANGLin XUGuo-li WANGDivya RANATong LIUDi-di WUBing-zhi YU
