Past studies have observed that BHPF induces multi-organ toxicity, however, whether it induces damage to male reproductive system and the specific mechanism remains unclear. In the present study, male mice were given 0, 2, 10 or 50 mg/kg/day of BHPF by gavage for 35 days to observe its effect on reproductive organ and sperm quality. The results indicated that BHPF decreased sperm count and sperm motility in a dose-dependent manner. Besides, our results demonstrated that BHPF triggered the proliferation inhibition and cell death of germ cells in vivo and in vitro. Also, BHPF reduced the expression of function markers for germ cells, Sertoli cells, and Leydig cells, indicating its damage to function of testis cells. Simultaneously, testicular microenvironment was found to be altered by BHPF, as presented with declined testosterone level and decreased expression of local microenvironment regulators. Overall, our findings indicated the detrimental effects of BHPF on male reproductive function in mice, suggesting testicular function and local microenvironment disturbance as mechanism underlying testicular damage.

Among the many factors with a proven relation to semen quality and male fertility, the determination of seminal plasma cytokines provides a promising direction for research into the identification of factors connected with male infertility. The interleukins: IL-1α, -1β, -2, -4, -6, -8, -10, -12p40, -12p70, -18, IFNγ, and GM-CSF, total oxidant (TOS) and antioxidant (TAS) status, were simultaneously examined in seminal plasmas and blood sera in terato- (n = 32), asthenoterato- (n = 33), and oligoasthenoteratozoospermic (n = 29) infertile men and in normozoospermic fertile men (n = 20). Our research shows different cytokine composition of the sera and seminal plasmas in all studied groups, along with much higher concentrations of seminal plasma GM-CSF, IFNγ, IL-1α, IL-4, IL-6, and IL-8 and lower IL-18 and TOS in the comparison to their sera levels. The seminal plasma concentrations of GM-CSF, IFNγ, IL-1α, -4, and -6 differ significantly between fertile and infertile as well as between teratozoospermic, asthenoteratozoospermic, and oligoasthenoteratozoospermic groups. The indication of the cause of different concentrations of cytokines in seminal plasmas of infertile men, and their associations with semen parameters and oxidative status, may be a promising direction for the search for new therapeutic targets that would directly affect the cells and tissues of male reproductive organs.

Semen analysis is essentially used to check the fertility of a man, especially when couples are having difficulties conceiving. Studies concerning male fertility, testicular factors, and seminal characteristics have been under investigation for the last few decades. In 1980, the World Health Organization (WHO) started reaching out to scientists in order to set standards for high-quality semen and develop a semen manual. From this point to the present, six editions of this manual have been produced, delineating the characteristics of semen and reporting protocols for semen analysis. Sperm morphology is analyzed as per WHO norms to measure the biological capacity of a male for reproduction. Both national and international manuals have been developed, with the latest, the sixth edition, produced in July 2021. This review paper conveys the current WHO publication\'s updates and identifies the clinical recommendations for proper evaluations. The publication considers the characteristics of semen in order to discuss the content of the previous editions of the WHO. It is also utilized to assess the method applied to determine the DNA presence of sperm fragmentation.

Inner dynein arms (IDAs) are formed from a protein complex that is essential for appropriate flagellar bending and beating. IDA defects have previously been linked to the incidence of asthenozoospermia (AZS) and male infertility. The testes-enriched ZMYND12 protein is homologous with an IDA component identified in Chlamydomonas. ZMYND12 deficiency has previously been tied to infertility in males, yet the underlying mechanism remains uncertain. Here, a CRISPR/Cas9 approach was employed to generate Zmynd12 knockout (Zmynd12-/-) mice. These Zmynd12-/- mice exhibited significant male subfertility, reduced sperm motile velocity, and impaired capacitation. Through a combination of co-immunoprecipitation and mass spectrometry, ZMYND12 was found to interact with TTC29 and PRKACA. Decreases in the levels of PRKACA were evident in the sperm of these Zmynd12-/- mice, suggesting that this change may account for the observed drop in male fertility. Moreover, in a cohort of patients with AZS, one patient carrying a ZMYND12 variant was identified, expanding the known AZS-related variant spectrum. Together, these findings demonstrate that ZMYND12 is essential for flagellar beating, capacitation, and male fertility.

With the improvement of medical devices for diagnosis and radiotherapy, concerns about the effects of low doses of ionizing radiation are also growing. There is no consensus among scientists on whether they might have beneficial effects on humans in certain cases or pose more risks, making the exposure unreasonable. While the damaging consequences of high-dose radiation have been known since the discovery of radioactivity, low-dose effects present a much bigger investigative challenge. They are highly specific and include radio-adaptive responses, bystander effects, and genomic instability. Current data regarding the consequences of exposure to low-dose radiation on the quality of male gametes and fertility potential are contradictory. The reports suggest two directions: indirect impact on male gametes-through spermatogenesis-or direct effects at low doses on already mature spermatozoa. Although mature gametes are used for observation in both models, they are fundamentally different, leading to varied results. Due to their unique physiological characteristics, in certain cases, exposure of spermatozoa to low-dose ionizing radiation could have positive effects. Despite the findings indicating no beneficial effects of low-dose exposure on male fertility, it is essential to research its impact on mature spermatozoa, as well.

This comprehensive review explores the existing literature on the effects of radiotherapy on testicular function, focusing mainly on spermatogenic effects, but also with a brief report on endocrine abnormalities. Data from animal experiments as well as results on humans either from clinical studies or from accidental radiation exposure are included to demonstrate a complete perspective on the level of vulnerability of the testes and their various cellular components to irradiation. Even relatively low doses of radiation, produced either from direct testicular irradiation or more commonly from scattered doses, may often lead to detrimental effects on sperm count and quality. Leydig cells are more radioresistant; however, they can still be influenced by the doses used in clinical practice. The potential resultant fertility complications of cancer radiotherapy should be always discussed with the patient before treatment initiation, and all available and appropriate fertility preservation measures should be taken to ensure the future reproductive potential of the patient. The topic of potential hereditary effects of germ cell irradiation remains a controversial field with ethical implications, requiring future research.

BACKGROUND: Infertility is a major health issue, affecting 15% of reproductive-age couples with male factors contributing to 50% of cases. Asthenozoospermia (AS), or low sperm motility, is a common cause of male infertility with complex aetiology, involving genetic and metabolic alterations, inflammation and oxidative stress. However, the molecular mechanisms behind low motility are unclear. In this study, we used a metabolomics approach to identify metabolic biomarkers and pathways involved in sperm motility.
METHODS: We compared the metabolome and lipidome of spermatozoa of men with normozoospermia (n = 44) and AS (n = 22) using untargeted LC-MS and the metabolome of seminal fluid using 1H-NMR. Additionally, we evaluated the seminal fluid redox status to assess the oxidative stress in the ejaculate.
RESULTS: We identified 112 metabolites and 209 lipids in spermatozoa and 27 metabolites in the seminal fluid of normozoospermic and asthenozoospermic men. PCA analysis of the spermatozoa\'s metabolomics and lipidomics data showed a clear separation between groups. Spermatozoa of asthenozoospermic men presented lower levels of several amino acids, and increased levels of energetic substrates and lysophospholipids. However, the metabolome and redox status of the seminal fluid was not altered inAS.
CONCLUSIONS: Our results indicate impaired metabolic pathways associated with redox homeostasis and amino acid, energy and lipid metabolism in AS. Taken together, these findings suggest that the metabolome and lipidome of human spermatozoa are key factors influencing their motility and that oxidative stress exposure during spermatogenesis or sperm maturation may be in the aetiology of decreased motility in AS.

Infertility is a global health problem affecting one in six couples, with 50% of cases attributed to male infertility. Spermatozoa are male gametes, specialized cells that can be divided into two parts: the head and the flagellum. The head contains a vesicle called the acrosome that undergoes exocytosis and the flagellum is a motility apparatus that propels the spermatozoa forward and can be divided into two components, axonemes and accessory structures. For spermatozoa to fertilize oocytes, the acrosome and flagellum must be formed correctly. In this Review, we describe comprehensively how functional spermatozoa develop in mammals during spermiogenesis, including the formation of acrosomes, axonemes and accessory structures by focusing on analyses of mouse models.

Regulation of gene expression through histone modifications underlies cell homeostasis and differentiation. Kdm4d and Kdm4dl exhibited a high degree of similarity and demethylated H3K9me3. However, the physiological functions of these proteins remain unclear. In this study, we generated Kdm4dl mutant mice and found that Kdm4dl was dispensable for mouse development. However, through the generation of Kdm4d mutant mice, we unexpectedly found that Kdm4d mutant male mice were subfertile because of impaired sperm motility. The absence of Kdm4d was associated with an altered distribution of H3K9me3 in round spermatids, suggesting that the Kdm4d-mediated adjustment of H3K9me3 levels is required to generate motile sperm. Further analysis revealed that the absence of Kdm4d did not affect the functionality of sperm nuclei in generating offspring. As KDM4D is specifically expressed in the human testes, our results suggest that KDM4D expression may be a risk factor for human infertility.

Male infertility is a serious ongoing problem, whose causes have not yet been clearly identified. However, since human exposure to silver nanoparticles (AgNPs) has recently increased due to their beneficial properties, the present study aimed to determine the impact of small-size AgNPs on mouse spermatogonia (GC-1 spg) and spermatocytes [GC-2 spd(ts)] in vitro models as well as the ability of these nanostructures to induce inflammation. The results showed a significant dose- and time-dependent decrease in the metabolic activity in both cell models, which was correlated with an increase in the intracellular ROS level. Moreover, increased activity of caspase-9 and -3, together with enhanced expression of CASP3 and p(S15)-p53 proteins, was detected. Further studies indicated a decrease in ΔΨm after the AgNP-treatment, which proves induction of apoptosis with engagement of an intrinsic pathway. The PARP1 protein expression, the activity and protein expression of antioxidant enzymes, the GSH level, and the increased level of p-ERK1/2 indicate not only the engagement of DNA damage but also the occurrence of oxidative stress. The small-size AgNPs were able to induce inflammation, proved by increased protein expression of NF-κB, p-IκBα, and NLRP3, which indicate damage to spermatogonia and spermatocyte cells. Moreover, the PGC-1α/PPARγ and NRF2/Keap1 pathways were engaged in the observed effect. The spermatogonial cells were characterized by a stronger inflammation-based response to AgNPs, which may be correlated with the TNFα/TRAF2-based pathway. Summarizing, the obtained results prove that AgNPs impair the function of testis-derived cells by inducing the redox imbalance and inflammation process; therefore, these NPs should be carefully implemented in the human environment.