Fertility in the male is dependent on the proper production of sperm cells. This process, called spermatogenesis is very complex and involves the synchronization of numerous factors. The presence of pro–inflammatory cytokines, tumor necrosis factor-alpha (TNF–α), interleukin–1 alpha (IL–1 α) and interleukin 1 beta (IL–1 β) cytokines in the male reproductive tract (testis, epididymis and sperm) may have certain physiological functions. However, when the levels of these cytokines are higher than normal, as seen in conditions of inflammation, they become very harmful to sperm production. Moreover, inflammation is also associated with oxidative stress and the latter is well known to impair sperm function. Epidemiological studies regarding male infertility have revealed that more and more infertile men suffer from acute or chronic inflammation of the genitourinary tract, which often occurs without any symptoms. The inflammatory reactions within the male genital tract are inevitably connected with oxidative stress. Oxidative stress, especially in sperm, is harmful because it damages sperm DNA and causes apoptosis in sperm. This article reviewed the suggested mechanisms and contribution of inflammation to male infertility. In addition, the review was further strengthened by discussing how inflammation affects both fertility and assisted reproductive technologies (ART).
The precise temporal and spatial expressions of specific transcription regulation factors (TRF) have long been considered essential for spermatogenesis. Recently, it has been speculated that mammals have evolved more specialised TRF genes. In the human, the TAF7L gene may be essential for maintenance of spermatogenesis. In this study, we investigated the possible role of the TAF7L gene located on the X chromosome in testicular function and spermatogenic failure. In a case‐controlled retrospective study, we recruited 16 infertile males with consistent, nonobstructive azoospermia and with normal serum follicle‐stimulating hormone (FSH) levels. Twenty age‐matched men with normal spermatogenesis with the same ethnic background (Caucasian) were recruited as controls. Their genomic DNA was screened for sequence changes in the coding regions and part of the flanking introns of the TAF7L gene by direct sequencing. Amino acid sequence was compared with the NCBI standard sequence (BC043391). Semen analysis and hormone evaluation were performed. We observed six sequence variations in four patients, consisting of two point mutations, one each in exon 9 and 13 and one six‐basepair deletion in exon 13 with concomitant changes in amino acid. One additional nucleotide exchange was observed in intron 8. Most of these changes were also found in eight controls with the exception of changes in exon 13. A meta‐analysis including the present study and literature data suggests a possible association of the point mutation in exon 13 with infertility. There was no association or relationship with reproductive hormones. In conclusion, the sequence variants in the cDNA sequence observed are common polymorphisms. The changes in intron 8 appear novel. We report for the first time that most of the alterations are not associated with gonadal dysfunction, while the sequence variant in exon 13 may represent a risk factor for spermatogenic failure.