The Role of Seminal Oxidative Stress Scavenging System in the Pathogenesis of Sperm DNA Damage in Men Exposed and Not Exposed to Genital Heat Stress

Monika Fraczek,Marzena Kamieniczna,Jozef Nakonechnyy,Anna Havrylyuk,Angelika Lewandowska,Maciej Kurpisz,Marta Budzinska,Andrij Nakonechnyy,Michal Kups,Malgorzata Piasecka,Valentina Chopyak,Kamil Gill,Lukasz Wojnar

doi:10.3390/ijerph19052713

Abstract

Responding to the need for the verification of some experimental animal studies showing the involvement of oxidative stress in germ cell damage in the heat-induced testis, we investigated the possibility of a direct relationship between seminal oxidative stress markers (total antioxidant capacity, catalase activity, superoxide dismutase activity, and malondialdehyde concentration) and ejaculated sperm chromatin/DNA integrity (DNA fragmentation and chromatin condensation abnormalities) in distinct groups of men exposed and not exposed to prolonged scrotal hyperthermia. A statistical increase in the proportion of sperm with DNA fragmentation was observed in all the studied subgroups compared to the fertile men. In turn, the groups subjected to heat stress as professional drivers or infertile men with varicocele presented greater disturbances in the oxidative stress scavenging system than men not exposed to genital heat stress. Based on the comparative analysis of the studied parameters, we can conclude that alterations in the seminal oxidative stress scavenging system are directly engaged in the pathogenesis of ejaculated sperm DNA damage regardless of the intensity of the impact of thermal insult. To the best of our knowledge, this study, for the first time, revealed the co-existence of oxidative stress and sperm DNA damage in the semen of professional drivers.

Highlights

It is well established that the production and maturation of mammalian sperm are highly dependent on the scrotal temperature and run efficiently at a minimum of 2 ◦ C below that of the body core
The total antioxidant capacity was significantly reduced only in the groups exposed to genital heat stress compared to the control group (p < 0.001 for professional drivers and p < 0.01 for infertile men with varicocele)
As spermatozoa are characterized by an extremely high susceptibility to oxidative damage, seminal plasma released from accessory glands contains an abundant antioxidant system, which includes both enzymatic and nonenzymatic factors for effectively protecting spermatozoa against reactive oxygen species (ROS) attack

Summary

Introduction

It is well established that the production and maturation of mammalian sperm are highly dependent on the scrotal temperature and run efficiently at a minimum of 2 ◦ C below that of the body core. In this context, the dysfunction of local thermoregulatory systems is considered to be one of the main risk factors for male subfertility/infertility [1]. There are many different factors and situations associated with a raised scrotal temperature that induce genital heat stress. Everyday behavior such as a sedentary lifestyle, hot bath or sauna, tight clothing, or occupations performed in high temperatures are examples of.

Methods

Results

Conclusion