脑源性神经营养因子及其受体在小鼠卵母细胞第一极体释放中的作用

The role of brain-derived neurotrophic factor and its receptor tyrosine protein kinase B in the first polar body release of mouse oocytes

目的:探讨脑源性神经营养因子(BDNF)及其受体酪氨酸蛋白激酶受体B(TrkB)在卵母细胞第一极体释放中的作用。方法:用Affymetrix基因芯片分析在模拟卵母细胞成熟过程中BDNF及其受体TrkB在卵巢组织中的表达变化,用实时定量荧光PCR(RT-PCR)分析卵泡组织中BDNF及其受体TrkB的表达,并利用TrkB抑制剂K252a探讨BDNF在卵母细胞释放第一极体中作用。结果:在模拟卵母细胞成熟过程中,BDNF的表达出现2个峰值,第2个峰值比第1个峰值显著;TrkB的表达同样也出现2个峰值,但峰值均非常低。BDNF在卵丘细胞、壁层颗粒细胞和卵母细胞中均有表达,而TrkB仅在卵母细胞中表达。不同浓度(1,3,10,30ng/ml)BDNF均促使卵母细胞第一极体释放率升高(P<0.05),以3ng/ml组升高更显著。体内实验发现不同剂量K252a均能抑制卵母细胞第一极体释放率(P<0.05),但不同剂量组无统计学差异。结论:BDNF在卵母细胞的第一极体的释放过程中发挥重要作用。

Objective:To investigate the role of brain-derived neurotrophic factor(BDNF)and its receptor tyrosine protein kinase B(TrkB)in the release of the first polar body of oocytes.Methods:The expression of BDNF and its receptor TrkB in ovarian tissue during oocyte maturation was analyzed by gene microarray of Affymetrix,and the expressions of BDNF and its receptor TrkB in follicular tissue were analyzed by real-time quantitative PCR(RT-PCR).TrkB inhibitor K252a was used to study the role of BDNF in the first pole of oocyte release.Results:During the simulated maturation of oocytes,the expression of BDNF showed two peaks,the second peak was more significant than the first one.TrkB expression also showed two peaks,but both of them were very low.BDNF was expressed in cumulus cells,parietal granulosa cells,and oocytes,while TrkB was only expressed in oocytes.Different concentrations of BDNF(1,3,10,30 ng/ml)increased the rate of the first polar body released from oocytes,and the concentration of BDNF(3ng/ml)increased the rate of the first polar body released from oocytes more significantly.In vivo experiments showed that different doses of K252a could inhibit the rate of the first polar body released of oocyte(P<0.05),but different concentrations of K252a inhibitor had no significant difference in the rate of the first polar body released of oocyte.Conclusion:BDNF plays an important role in the release of the first polar body of oocytes.