Diagnosis of Male Infertility and Hypogonadism

Activation of C-C motif chemokine receptor 2 modulates testicular macrophages number, steroidogenesis, and spermatogenesis progression

The monocyte chemoattractant protein 1 (MCP-1) belongs to the CC chemokine family and acts in the recruitment of C-C motif chemokine receptor 2 (CCR2)-positive immune cell types to inflammation sites. In testis, the MCP-1/CCR2 axis has been associated with the macrophage population's functional regulation, which presents significant functions supporting germ cell development. In this context, herein, we aimed to investigate the role of the chemokine receptor CCR2 in mice testicular environment and its impact on male sperm production. Using adult transgenic mice strain that had the CCR2 gene replaced by a red fluorescent protein gene, we showed a stage-dependent expression of CCR2 in type B spermatogonia and early primary spermatocytes. Several parameters related to sperm production were reduced in the absence of CCR2 protein, such as Sertoli cell efficiency, meiotic index, and overall yield of spermatogenesis. Daily sperm production decreased by almost 40%, and several damages in the seminiferous tubules were observed. Significant reduction in the expression of important genes related to the Sertoli cell function (Cnx43, Vim, Ocln, Spna2) and meiosis initiation (Stra8, Pcna, Prdm9, Msh5) occurred in comparison to controls. Also, the number of macrophages significantly decreased in the absence of CCR2 protein, along with a disturbance in Leydig cell steroidogenic activity. In summary, our results show that the non-activation of the MCP-1/CCR2 axis disturbs the testicular homeostasis, interfering in macrophage population, meiosis initiation, blood-testis barrier function, and androgen synthesis, leading to the malfunction of seminiferous tubules, decreased testosterone levels, defective sperm production, and lower fertility index.

Gestational exposure to low-dose zearalenone disrupting offspring spermatogenesis might be through epigenetic modifications

Zearalenone (ZEA), a F-2 mycotoxin produced by Fusarium, has been found to be an endocrine disruptor through oestrogen receptor signalling pathway to impair spermatogenesis. The disruption on reproductive systems by ZEA exposure might be transgenerational. In our previous report, we have found that low dose (lower than no-observed effect level, NOEL) of ZEA impaired mouse spermatogenesis and decreased mouse semen quality. The purpose of the current investigation was to explore the impacts of low-dose ZEA on spermatogenesis in the offspring after prenatal exposure and the underlying mechanisms. And it demonstrated that prenatal low-dose ZEA exposure disrupted the meiosis process to inhibit the spermatogenesis in offspring and even to diminish the semen quality by the decrease in spermatozoa motility and concentration. The DNA methylation marker 5hmC was decreased, the histone methylation markers H3K9 and H3K27 were elevated, and oestrogen receptor alpha was reduced in the offspring testis after prenatal low-dose ZEA exposure. The data suggest that the disruption in spermatogenesis by prenatal low-dose ZEA exposure may be through the modifications on epigenetic pathways (DNA methylation and histone methylation) and the interactions with oestrogen receptor signalling pathway. Moreover, in the current study, the male offspring were indirectly exposed to low-dose ZEA through placenta and the spermatogenesis in offspring was disrupted which suggested that the toxicity of ZEA on reproductive systems was very severe. Therefore, we strongly recommend that greater attention should be paid to this mycotoxin to minimize its adverse impact on human spermatogenesis.

Chronic epididymitis and Grade III varicocele and their associations with semen characteristics in men consulting for couple infertility

Chronic epididymitis and varicocele are frequently observed genital disorders in men consulting for couple infertility, but their impact on semen characteristics at the time of infertility consultation is still a matter of debate. We investigated 652 male partners of couples who had their first infertility consultation between 1999 and 2015 in Argentina. Men with chronic epididymitis (n = 253), Grade III varicocele (n = 106), and both conditions (n = 125) were compared with a control group (n = 168) composed of men without these disorders or any other recognized causes of male infertility. We showed that men who presented isolated chronic epididymitis were more likely to have high percentages of low sperm motility and abnormal sperm morphology as well as a high number of white blood cells. Men with isolated Grade III varicocele had low sperm production and motility and an increased percentage of abnormal sperm morphology. Finally, men who simultaneously presented chronic epididymitis with Grade III varicocele had a low sperm motility and increased percentage of abnormal sperm morphology as well as a high number of white blood cells. Physical examination of the genital organs may identify common disorders, potentially involved as causal factors of patient's infertility. These disorders are associated with specific seminal profiles that should help in identifying the best treatment from the available therapeutic options, effectiveness, safety, and allowing as much as possible natural conception.