哺乳动物雷帕霉素靶蛋白(mTOR)在小鼠卵母细胞成熟过程中的表达及作用  

The Expression and Effect of mTOR During Mouse Oocyte Maturation

作　　者：杨彩荣[1] 魏延昌[1] 张岩[1] 郑可佳[1] 李宁[1] 严云勤[1] 

机构地区：[1]东北农业大学动物细胞与发育生物学教研室,哈尔滨150030

出　　处：《生物化学与生物物理进展》2009年第10期1334-1339,共6页Progress In Biochemistry and Biophysics

摘　　要：哺乳动物雷帕霉素靶蛋白(mammalian target of rapamycin,mTOR)是一种Ser/Thr激酶,属于PIKK超家族,对调节细胞周期、蛋白质合成等具有重要作用,是细胞生长、增殖、分化、凋亡的中心调控器,但在哺乳动物卵母细胞中的研究还未见报道.以小鼠卵母细胞为研究对象,采用免疫荧光为主要研究方法,对mTOR在小鼠卵母细胞中的表达进行研究,并通过mTOR的特异性抑制剂雷帕霉素(rapamycin,RAPA)对卵母细胞进行处理,对mTOR在卵母细胞成熟过程中的作用进行研究.结果显示:小鼠卵母细胞成熟过程中,生发泡(germinal vesicle,GV)期mTOR主要集中在核膜处表达,生发泡破裂(germinal vesicle breakdown,GVBD)后mTOR伴随染色体分布,第二次减数分裂中期(second metaphase,MⅡ期)mTOR伴随纺锤体分布;雷帕霉素处理后,小鼠卵母细胞的成熟受到抑制,且这种抑制作用具有浓度依赖性,同时其mTOR的表达部位和形态也发生变化.研究表明,在小鼠卵母细胞成熟过程中,mTOR在各个时期的表达及分布具有阶段特异性,并对小鼠卵母细胞GVBD的发生和第一极体的排放都具有重要作用.The mammalian target ofrapamycin （mTOR） is a serine-threonine kinase downstream in the PI3K-Akt pathway, which belongs to the phosphatidylinositol kinase-related kinase （PIKK） family. The mTOR palys an important role in cell cycle regulation and protein synthesis, mTOR signaling pathway is evolutionarily conserved, which can integrate and converge a wide range of signals, including intracellular and extracellular nutrients, growth factors, energy and stress conditions, and has a crucial role in vertebrate growth control. The upstream regulation and downstream effects mediated by mTOR form a network of critical growth signaling pathways. Hence, dysregulation of components within mTOR signaling network result in impaired intemal environment conditions, and first meiotic division can also be influenced if occurring during starfish and sea urchin oocyte maturation. However, its functions in mammalian meiosis are unclear. The localization and function of mTOR during mouse oocyte meiotic maturation were investigated with the oocytes of Kunming mouse. Location of mTOR was examined in Germinal vesicle （GV） stage, Germinal vesicle breakdown （GVBD） stage and second metaphase （M II ） stage during mouse oocyte maturation by immunofluorescence technology. The rate of GVBD and polar body extrusion （PB1） during mouse oocytes maturation was also detected by treatment with different concentration rapamycin （0.5 g/L, 2.5 g/L, 3.3 g/L, 5.0 g/L, 10 g/L ）. Immunofluorescent staining showed that mTOR mainly is located on nuclear membrane during GV stage, distributed with the chromosome after GVBD, and distributed with the spindle apparatus during M II stage. The oocyte maturation was inhibited by treatment with rapamycin, and the inhibitory action was concentration dependent, when the drug concentration reached to 3.3 g/L, the disparity was significant （P 〈 0.05）. Meanwhile, the location and morphous of mTOR were changed： under treatment with 3.3 g/L rapamycin, mTOR protein expression became obvious

关 键 词：雷帕霉素靶蛋白(mTOR) 小鼠卵母细胞 雷帕霉素 免疫荧光 

分 类 号：Q2[生物学—细胞生物学]