New approaches to male infertility: Forum introduction

Excerpt

It has been shown that reproductive potential of human population has a tendency to diminish. Approximately, 20% couples can be threatened by infertility out of those, male partners can be suspected for a leading reason of this disorder accounting for 40–60% cases. At the same time, modern techniques of assisted reproduction (ART) although quite aggressive, cannot exceed 1/3 part of couples who wish to be succesful in procedures of in vitro fertilization. An increased sensitivity of males to spermatogenetic disorders became one of the hot issues, intensively studied throughout the world. Therefore, it has been of great interest to look at intragonadal germ cells differentiation, looking at the network of molecular signaling in order to better understand spermatogenic disturbances that may even arise in pre-puberty [1]. It has been shown that several factors may put into question the fertilization potential of prepubertal boys. There can be procedures due to malignant diseases provoking chemo- and radiotherapy with severe consequences for the future fertility status. On the other hand, abnormalities in the male reproductive tract (uni- or bilateral cryptorchidism, testicular torsion, inguinal hernia, physical injuries of testis) may induce anti-sperm antibodies with severe consequences that can be visible only at reproductive age. Once developed antisperm antibodies may be sustained and enhanced through bacterial or viral infections and subsequently may stop or severely alter spermatogenesis [2]. On the other hand, inflammatory process in the testis may be perpetuated to that level (by pro-inflammatory cytokines) that may completely inhibit spermatogenesis in sexually mature individuals through enhanced oxygen metabolism (ROS – reactive oxygen species) which in turn may mediate germ cells apoptosis. The first paper of our Forum (by J. Lysiak) is addressing this problem describing different pathways of apoptotic mediation through IL-1, TNF-alpha and IL-18. In our recent studies, we have detected in the male gonad (on mRNA level) possibilityfor IL-18 auto-regulation through IL-18 accessory protein in heterodimeric receptor for IL-18. It is question of intensity (or type) of inflammatory factor that may drive to one of the three-mediated apoptotic pathways directed through the mentioned cytokines. …