褪黑素保护卵母细胞应对热应激损伤的研究

Melatonin protects mouse oocyte from heat stress damage

目的探讨褪黑素对热激条件下小鼠卵母细胞体外成熟的潜在影响。方法采用小鼠卵母细胞成熟的热激模型,将卵母细胞随机分成3组,分别是对照组、热激组和热激+褪黑素组,测定1×10-9 mol/L褪黑素对热激后卵母细胞质量的改善作用。结果与对照组相比,热激组小鼠卵母细胞成熟率显著下降[(33.00±0.07)%vs.(85.00±0.03)%,P<0.01],纺锤体组装异常,早期凋亡比率显著增加[(59.7±4.5)%vs.(22.0±3.5)%,P<0.01];热激+褪黑素组与热激组相比,卵母细胞成熟率显著上升[(70.00±0.05)%vs.(33.00±0.07)%,P<0.01],纺锤体异常比率显著下降,发生早期凋亡的卵母细胞比率亦显著下降[(37.3±6.1)%vs.(59.7±4.5)%,P<0.01]。热激+褪黑素组热休克蛋白70的表达水平与对照组和热激组相比显著上调(P<0.01)。结论褪黑素能通过调节热激后热休克蛋白70过表达来改善热激对卵母细胞造成的成熟率下降、纺锤体组装异常和早期凋亡比率的增加。

Objective:To explore the potential effect of melatonin on the in vitro maturation of mouse oocytes under heat shock condition.Methods:This study used a heat shock model of mouse oocyte maturation.The oocytes were randomly divided into three groups:control group,heat shock group and heat shock plus melatonin group.The effect of 1×10^-9 mol/L melatonin on the quality of oocytes after heat shock was measured.Results:The maturation rate of mouse oocytes was significantly decreased under heat shock condition compared the control group[(33.00±0.07)% vs.(85.00±0.03)%,P<0.01].The assembly of spindle was abnormal and the early apoptosis rate was significantly increased[(59.7±4.5)% vs.(22.0±3.5)%,P<0.01].After adding melatonin,the oocytes maturation rate was significantly increased compared with the heat shock group[(70.00±0.05)% vs.(33.00±0.07)%,P<0.01],and the abnormal rate of spindle assembly and the early apoptosis rate were significantly decreased[(37.3±6.1)%vs.(59.7±4.5)%,P<0.01].The expression level of heat shock protein 70 was significantly up-regulated in the heat shock plus melatonin group compared with the other two groups(P<0.01).Conclusions:Melatonin can improve the decline of maturation rate on oocytes,the abnormality of spindle assembly,and the increase of early apoptosis rate caused by heat shock by regulating the expression of heat shock protein 70.