Naresh Sai, Atreja Suresh Kumar
Reproductive Biochemistry Laboratory, Animal Biochemistry Division, National Dairy Research Institute, Karnal, Haryana 132001, India.
Cryobiology. 2015 Jun;70(3):211-6. doi: 10.1016/j.cryobiol.2015.03.008. Epub 2015 Mar 28.
Before the process of fertilization, spermatozoa necessitate a period of residence in the female reproductive environment, and undergo a sequence of physiological and biochemical changes collectively referred to as capacitation. Accumulated evidences from several laboratories indicated that the protein tyrosine phosphorylation (PTP) is one of the most important intracellular signaling events regulating sperm function, and is a meaningful indicator of capacitation. Different factors that affect PTP are cholesterol efflux, influx of HCO3(-), increased intracellular Ca(2+), cAMP and reactive oxygen species (ROS). cAMP/PKA and extracellular signal regulated kinases (ERKs) are the known important signaling pathways primarily involved in PTP. Advanced proteomics approaches have revealed several proteins that undergo tyrosine phosphorylation during capacitation. Semen cryopreservation subjects spermatozoa to frequent stressors, which result in capacitation like changes (cryo-capacitation). The cryo-capacitated spermatozoa usually show different patterns of PTP than the normal in vitro capacitated spermatozoa. In the current manuscript, we have summarized some information about the proteins undergoing tyrosine phosphorylation during capacitation and the effect of cryopreservation on PTP as well as the possibilities to reduce the changes associated with cryopreservation process.
在受精过程之前，精子需要在雌性生殖环境中停留一段时间，并经历一系列生理和生化变化，这些变化统称为获能。多个实验室积累的证据表明，蛋白质酪氨酸磷酸化（PTP）是调节精子功能的最重要的细胞内信号事件之一，也是获能的一个有意义的指标。影响PTP的不同因素有胆固醇外流、HCO3(-)内流、细胞内Ca(2+)增加、cAMP和活性氧（ROS）。cAMP/PKA和细胞外信号调节激酶（ERK）是已知主要参与PTP的重要信号通路。先进的蛋白质组学方法已经揭示了几种在获能过程中发生酪氨酸磷酸化的蛋白质。精液冷冻保存使精子频繁受到应激源的影响，从而导致类似获能的变化（冷冻获能）。冷冻获能的精子通常显示出与正常体外获能精子不同的PTP模式。在本手稿中，我们总结了一些关于获能过程中发生酪氨酸磷酸化的蛋白质的信息、冷冻保存对PTP的影响以及减少与冷冻保存过程相关变化的可能性。
