Correlation between Sperm Parameters and Protein Expression of Antioxidative Defense Enzymes in Seminal Plasma: A Pilot Study

Abstract

Background. Semen analysis is the cornerstone in the evaluation of male (in)fertility. However, there are men with normal semen tests but with impaired fertilizing ability, as well as fertile men with poor sperm characteristics. Thus, there is rising interest to find novel parameters that will help to predict and define the functional capacity of spermatozoa. Methods. We examined whether there is a correlation between semen parameters (count, progressive motility, and morphology) and protein expression/activity of antioxidative defense enzymes in seminal plasma from 10 normospermic subjects. Results. Sperm progressive motility was in positive correlation with seminal plasma protein expression of both superoxide dismutase (SOD) isoforms (MnSOD and CuZnSOD) and catalase. Also, positive correlation was observed between sperm count and MnSOD protein expression, as well as between sperm morphology and protein expression of catalase in seminal plasma. In contrast, protein expression of glutathione peroxidase was not in correlation with any sperm parameter, while its activity negatively correlated with sperm morphology and motility. Conclusions. These data suggest that evaluation of protein expression of antioxidative defense enzymes in seminal plasma might be of importance in the evaluation of male fertility status and that could be used as an additional biomarker along with classic semen analysis in assessment of semen quality.

Physiological and Pathological Roles of Free Radicals in Male Reproduction

“…Also, positive correlations were observed between sperm morphology and protein expression of CAT in seminal plasma [98,99]. Furthermore, CAT supplementation to fresh, processed and cryopreserved semen resulted in a higher sperm vitality, progressive motility and DNA integrity [100].…”

Reactive oxygen, nitrogen, and sulfur species in human male fertility. A crossroad of cellular signaling and pathology

“…In mitochondria, spermatozoa possess manganese superoxide dismutase (MnSOD), glutathione peroxidase 4 (GSH‐Px 4), peroxiredoxin 2–6 (PRDX 2–6), thioredoxin 2 (TRX 2), TR, while in nuclei has been detected GSH‐Px 4, PRDX 1–6 and TRX 1 . Low spermatozoa's antioxidative capacity is compensated by antioxidative system in seminal plasma consisting of GSH‐Px 1, catalase, SODs and a variety of non‐enzymatic antioxidants . During the early phases of spermatogenesis GSH‐Px 4 is enzymatically active and functions as a peroxidase directly reducing peroxidized phospholipids produced in cell membranes .…”

“…25 Low spermatozoa's antioxidative capacity is compensated by antioxidative system in seminal plasma consisting of GSH-Px 1, catalase, SODs and a variety of non-enzymatic antioxidants. 3 During the early phases of spermatogenesis GSH-Px 4 is enzymatically active and functions as a peroxidase directly reducing peroxidized phospholipids produced in cell membranes. 26 However, in mature spermatozoa GSH-Px 4 uses hydroperoxides for the formation of a structural element of the spermatozoa that is essential for male fertility.…”

“…Current lifestyle and environmental factors significantly affect human reproduction by decreasing quality of male reproductive cells. 1,3 This clearly points out the importance of finding a new approach to improve male fertility. The growing interest and extent of research in this field have made it evident that redox signaling is important for spermatozoa functioning.…”

“…It has been recognized that nearly in a half of these cases, infertility is attributable to a male factor. Current lifestyle and environmental factors significantly affect human reproduction by decreasing quality of male reproductive cells . This clearly points out the importance of finding a new approach to improve male fertility.…”