精子功能的生理机制及研究进展

Research Progress in the Physiological Mechanism of Sperm Activition

启动及激活精子功能是一个复杂的过程,涉及多种信号分子及信号通路。精子在睾丸中生成、附睾中获得运动能力后,进入雌性生殖道后发生超活化,为精子获能提供前提条件,随后精子在环磷酸腺苷-蛋白激酶A(cAMP-PKA)、细胞外信号调节激酶-丝裂原活化蛋白激酶(ERK-MAPK)、内源性大麻素等通路的介导下完成获能,并快速移动至卵子处。此时顶体反应启动,复杂的级联信号通路介导精子完成膜融合,释放顶体酶,帮助精子穿越卵丘细胞团间隙和透明带。成功进入卵周膜间隙的精子,识别并结合卵子细胞膜表面的蛋白,在热休克蛋白、精子赤道片段蛋白、半胱氨酸分泌蛋白以及整联蛋白金属蛋白酶-整合素(ADAM-Integrin)、Izumo1-Juno蛋白对的协助下,完成精卵膜融合。本文就精子获能、顶体反应、受精的生理机制进行综述。

The initiation and activation of sperm function is a complex process,involving multiple signaling molecules and pathways.Sperm undergo the activation in epididymis after generated in testis and the hyperactivation in female reproductive tract,which is a prerequisite for sperm capacitation.Subsequently,spermatozoa achieve capacitation under the mediations of cAMP-PKA,ERK-MAPK,endocannabinoid and other pathways,and quickly move to the egg.At this point,the acrosomal reaction starts,and a complex cascade of signaling pathways mediates the fusion of membrane and the release of acrosomal enzymes,in which sperm cross the cumulus interstitial and zona pellucida.The sperm recognize and bind the proteins on the membrane surface of the egg after successfully entered the perioocyte space.With the assistance of heat shock protein,sperm equatorial segment proteins,cysteine-rich secretory proteins and some protein pairs such as ADAM-Integrin,Izumo1-Juno,the sperm-egg fusion was completed.In this paper,we reviewed the mechanisms of sperm capacitation,acrosomal reaction and fertilization.