Parkinson Disease Protein 7 (PARK7) Is Related to the Ability of Mammalian Sperm to Undergo In Vitro Capacitation

Abstract

Parkinson disease protein 7 (PARK7) is a multifunctional protein known to be involved in the regulation of sperm motility, mitochondrial function, and oxidative stress response in mammalian sperm. While ROS generation is needed to activate the downstream signaling pathways required for sperm to undergo capacitation, oxidative stress has detrimental effects for sperm cells and a precise balance between ROS levels and antioxidant activity is needed. Considering the putative antioxidant role of PARK7, the present work sought to determine whether this protein is related to the sperm ability to withstand in vitro capacitation. To this end, and using the pig as a model, semen samples were incubated in capacitation medium for 300 min; the acrosomal exocytosis was triggered by the addition of progesterone after 240 min of incubation. At each relevant time point (0, 120, 240, 250, and 300 min), sperm motility, acrosome and plasma membrane integrity, membrane lipid disorder, mitochondrial membrane potential, intracellular calcium and ROS were evaluated. In addition, localization and protein levels of PARK7 were also assessed through immunofluorescence and immunoblotting. Based on the relative content of PARK7, two groups of samples were set. As early as 120 min of incubation, sperm samples with larger PARK7 content showed higher percentages of viable and acrosome-intact sperm, lipid disorder and superoxide levels, and lower intracellular calcium levels when compared to sperm samples with lower PARK7. These data suggest that PARK7 could play a role in preventing sperm from undergoing premature capacitation, maintaining sperm viability and providing a better ability to keep ROS homeostasis, which is needed to elicit sperm capacitation. Further studies are required to elucidate the antioxidant properties of PARK7 during in vitro capacitation and acrosomal exocytosis of mammalian sperm, and the relationship between PARK7 and sperm motility.

Identification and Validation of Yak (Bos grunniens) Frozen–Thawed Sperm Proteins Associated with Capacitation and the Acrosome Reaction

“…GSEA analyses revealed significant MAPK and cAMP pathway gene set downregulation in the AR samples relative to the FTH sperm samples, in line with prior data indicating that these MAPK and cAMP pathways can regulate capacitation and AR induction in sperm . Parkinson’s disease protein 7 (PARK7) is an essential regulator of sperm motility, oxidative stress responses, mitochondrial function, and fertility. − PARK7, also known as DJ-1, localizes to the head, anterior midpiece, and principal piece of human sperm, while it has also been observed on the surface of the equatorial segment in sperm from mammalian species including sheep, horses, rats, hamsters, rabbits, and cattle . While the exact role that PARK7 plays in sperm has yet to be fully clarified, it is believed to be linked to the oxidative stress response. , A positive correlation between PARK7 levels and sperm plasma membrane integrity, total motility, and SOD activity has been reported in humans .…”

“…Given that spermatozoa are largely transcriptionally and translationally inactive, increases in gene expression are unlikely to explain observed differences in protein levels in these cells, instead suggesting that these changes are attributable to processes such as translocation, degradation, or protein modification. 27,62 More proteins were found to be downregulated following sperm incubation in the capacitation medium, and the requirement for protein degradation during the sperm capacitation process was regulated by Tyr-P levels, 25,63 with similar findings having been reported in the context of cattle sperm capacitation. 19 In addition, studies have shown that the abundance of three serine protein inhibitor (SERPINE) family members (SERPINA3-3, SERPINA3-3, and SERPINB6) was reduced in cattle fresh sperm under capacitation conditions, 19 whereas no changes in SERPINE expression were observed in the present study in the context of frozen−thawed sperm capacitation.…”

“…128−130 PARK7, also known as DJ-1, localizes to the head, anterior midpiece, and principal piece of human sperm, 131 while it has also been observed on the surface of the equatorial segment in sperm from mammalian species including sheep, horses, rats, hamsters, rabbits, and cattle. 63 While the exact role that PARK7 plays in sperm has yet to be fully clarified, it is believed to be linked to the oxidative stress response. 129,130 A positive correlation between PARK7 levels and sperm plasma membrane integrity, 132 total motility, and SOD activity has been reported in humans.…”

“…While the exact role that PARK7 plays in sperm has yet to be fully clarified, it is believed to be linked to the oxidative stress response. , A positive correlation between PARK7 levels and sperm plasma membrane integrity, total motility, and SOD activity has been reported in humans . Even so, the link between PARK7 and sperm capacitation has only been evaluated in pigs, and there have been no reports detailing the link between this protein and AR induction. Here, PPI network predictions suggested that PARK7 is a central mediator of sperm maturation, with PARK7 levels dynamically decreasing through sequential incubation in capacitation and AR induction medium, consistent with prior evidence, , As noted previously, high levels of ROS can adversely impact sperm cells, necessitating efforts to precisely control these levels in the context of capacitation and AR.…”

“…Even so, the link between PARK7 and sperm capacitation has only been evaluated in pigs, and there have been no reports detailing the link between this protein and AR induction. Here, PPI network predictions suggested that PARK7 is a central mediator of sperm maturation, with PARK7 levels dynamically decreasing through sequential incubation in capacitation and AR induction medium, consistent with prior evidence, , As noted previously, high levels of ROS can adversely impact sperm cells, necessitating efforts to precisely control these levels in the context of capacitation and AR. Antioxidant compounds and enzymes can thereby regulate sperm capacitation and AR status. − Thus, PARK7 may also act as a modulator of ROS levels over the course of these critical sperm maturation processes.…”