Department of Cell Biology, Charles University, Vinicna 7, Prague 2, 128 44, Czech Republic.
Reproduction. 2012 Mar;143(3):297-307. doi: 10.1530/REP-11-0326. Epub 2011 Dec 5.
In order for mammalian sperm to obtain a fertilizing ability, they must undergo a complex of molecular changes, called capacitation. During capacitation, steroidal compounds can exert a fast nongenomic response in sperm through their interaction with plasma membrane receptors, and activate crucial signaling pathways leading to time-dependent protein tyrosine phosphorylation (TyrP). Estrogen receptor beta was detected in epididymal mouse sperm; therefore, the effect of 17B-estradiol, estrone, estriol, and 17A-ethynylestradiol on mouse sperm capacitation in vitro was investigated. The effect was evaluated by positive TyrP in sperm heads and in the whole sperm lysates. Simultaneously, the state of the acrosome after the calcium ionophore-induced acrosome reaction was assessed. Generally, estrogens displayed a time and concentration-dependent stimulatory effect on sperm TyrP during capacitation. In contrast, the number of sperm that underwent the acrosome reaction was lower in the experimental groups. It has been demonstrated that both natural and synthetic estrogens can modify the physiological progress of mouse sperm capacitation. The potential risk in the procapacitation effect of estrogens can also be seen in the decreased ability of sperm to undergo the acrosome reaction. In conclusion, the capacitating ability of sperm can be significantly lowered by increasing the level of estrogens in the environment.
为了使哺乳动物精子获得受精能力，它们必须经历一系列复杂的分子变化，称为获能。在获能过程中，甾体化合物可以通过与质膜受体相互作用，在精子中产生快速的非基因组反应，并激活导致时间依赖性蛋白酪氨酸磷酸化（TyrP）的关键信号通路。在附睾中的小鼠精子中检测到了雌激素受体β；因此，研究了 17β-雌二醇、雌酮、雌三醇和 17α-乙炔雌二醇对体外培养的小鼠精子获能的影响。通过精子头部和整个精子裂解物中的阳性 TyrP 来评估效果。同时，评估了钙离子载体诱导顶体反应后顶体的状态。总的来说，雌激素在精子获能过程中表现出时间和浓度依赖性的 TyrP 刺激作用。相比之下，实验组中发生顶体反应的精子数量较少。已经证明，天然和合成雌激素都可以改变小鼠精子获能的生理过程。在雌激素的预获能作用中也可以看到潜在的风险，即精子发生顶体反应的能力降低。总之，环境中雌激素水平的增加会显著降低精子的获能能力。
