Laboratory of Cell Biology, Research Institute for Biosciences, Research Institute for Health Sciences and Technology, University of Mons, Place du Parc 23, 7000 Mons, Belgium.
Evolutionary Biology & Ecology, Université Libre de Bruxelles, Avenue Paul Héger-CP 160/12, 1000 Brussels, Belgium.
Int J Mol Sci. 2022 Jun 10;23(12):6497. doi: 10.3390/ijms23126497.
HSP70s constitute a family of chaperones, some isoforms of which appear to play a role in sperm function. Notably, global proteomic studies analyzing proteins deregulated in asthenozoospermia, a main cause of male infertility characterized by low sperm motility, showed the dysregulation of some HSP70 isoforms. However, to date, no clear trend has been established since the variations in the abundance of HSP70 isoforms differed between studies. The HSPA2 isoform has been reported to play a key role in fertilization, but its dysregulation and possible relocation during capacitation, a maturation process making the spermatozoon capable of fertilizing an oocyte, is debated in the literature. The aim of the present study was to investigate the fate of all sperm HSP70 isoforms during capacitation and in relation to sperm motility. Using Multiple-Reaction Monitoring (MRM) mass spectrometry, we showed that the relative abundance of all detected isoforms was stable between non-capacitated and capacitated spermatozoa. Immunofluorescence using two different antibodies also demonstrated the stability of HSP70 isoform localization during capacitation. We also investigated spermatozoa purified from 20 sperm samples displaying various levels of total and progressive sperm motility. We showed that the abundance of HSP70 isoforms is not correlated to sperm total or progressive motility.
热休克蛋白 70 家族构成伴侣蛋白，其中一些同工型似乎在精子功能中发挥作用。值得注意的是，对导致男性不育的主要原因——弱精子症中失调蛋白进行的全局蛋白质组学研究表明，一些 HSP70 同工型失调。然而，迄今为止，由于不同研究中 HSP70 同工型丰度的变化不同，尚未建立明确的趋势。HSPA2 同工型被报道在受精中起关键作用，但关于其在获能过程中的失调和可能重定位存在争议，获能是使精子能够受精卵子的成熟过程。本研究旨在调查所有精子 HSP70 同工型在获能过程中的命运及其与精子运动性的关系。使用多重反应监测 (MRM) 质谱法，我们表明，在非获能和获能精子之间，所有检测到的同工型的相对丰度是稳定的。使用两种不同抗体的免疫荧光也证明了 HSP70 同工型在获能过程中的定位稳定性。我们还研究了从 20 个显示不同总活力和前向运动活力的精子样本中纯化的精子。我们表明，HSP70 同工型的丰度与精子总活力或前向运动活力无关。
