Stimulation of plasminogen activator activity by free radicals in boar spermatozoa

Fertilization outcome could be regulated by binding of oviductal plasminogen to oocytes and by releasing of plasminogen activators during interplay between gametes

“…Previous studies have shown that plasminogen in the IVF medium increases penetration rate in mouse (21), decreases penetration rate in rat (19), has no effect on penetration rate in cow (23) or pig (22), or even induces a slight increase in penetration rate in the pig with doses 10 times lower than those used in the present study (40). Our results, tested in two species, either with the zymogen (plasminogen) or the active enzyme (plasmin), at concentrations similar to those found in the oviduct, consistently produced a reduction in sperm penetration.…”

“…Altogether, these studies suggest that the plasminogen/plasmin system may have a role during gamete interaction in the oviduct, but the results so far are controversial. Although an increased level of fertilization when plasminogen is added to the culture medium was first proposed in mouse (21), its participation in the regulation of polyspermy, hampering the sperm entry into the oocyte has also been shown in rats (19), as well as a lack of effect in pig and cattle (22,23). The main objective of the present study was to clarify this controversy.…”

Dietary omega-3 polyunsaturated fatty acids induce plasminogen activator activity and DNA damage in rabbit spermatozoa

“…However, in that study none of the diets had an effect on PAI-1 levels or on tPA activity. In boar spermatozoa, free radicals induce PAA, an effect blocked by superoxide dismutase (Kim et al, 2009). On the other hand, plasminogen activator activity (PAA) is modulated by ROS and antioxidants (Lavrentiadou et al, 2013;Oszajca et al, 2008).…”

“…On the other hand, plasminogen activator activity (PAA) is modulated by ROS and antioxidants (Lavrentiadou et al, 2013;Oszajca et al, 2008). In boar spermatozoa, free radicals induce PAA, an effect blocked by superoxide dismutase (Kim et al, 2009). Therefore, it was intriguing to investigate the potential modulation of PAA following incorporation of PUFA in the membranes of spermatozoa.…”

How Is Plasminogen/Plasmin System Contributing to Regulate Sperm Entry Into the Oocyte?

“…Second, tPA and uPA activity in spermatozoa or seminal plasma has also been demonstrated in different mammalian species. 14 –16 Bearing this in mind, it is plausible that plasminogen added into the IVF medium could be converted into plasmin by tPA or uPA from sperm origin and that such plasmin could be negatively affecting the sperm functionality under the experimental conditions used in the study by Mondéjar et al 4 This hypothesis is contrary to the data from Kim et al 17 showing that plasminogen increases the number of spermatozoa bound to oocytes and the percentage of oocytes with male pronucleus after fertilization. However, it is necessary to test it in the species (bovine and porcine) and conditions where the reduction in sperm penetration was observed 5 before discarding it.…”