Andrology最新文献

This review summarizes the molecular and cellular mechanisms underlying busulfan-induced male infertility and evaluates the translational potential of current and emerging therapeutic strategies. Evidence indicates that busulfan induces germ cell DNA alkylation damage, triggers sustained oxidative stress, and activates multiple cell death pathways. These events are accompanied by supporting cell dysfunction, disruption of the blood-testis barrier (BTB), and endocrine imbalance, collectively driving progressive impairment of spermatogenesis. In response to these pathological processes, various interventions have been explored, including antioxidant molecules, natural extracts, epigenetic modulation, and stem cell-related approaches, many of which show partial improvement of spermatogenic function in experimental models. In addition, clinical strategies used for other forms of male infertility, such as gonadotropin supplementation and antioxidant supportive therapy, provide relevant reference frameworks for chemotherapy-associated fertility impairment. However, most studies on busulfan-induced infertility remain preclinical, and their benefits largely reflect supportive modulation of the testicular microenvironment rather than definitive restoration of spermatogonial stem cells (SSCs) or repair of genotoxic damage. Based on an integrated assessment of current evidence, this review highlights key unresolved challenges, including the lack of a defined therapeutic safety window, limitations in targeted delivery, and difficulties in achieving fundamental reconstruction of the spermatogenic system. Accordingly, future studies should place greater emphasis on more effective isolation and protection of testicular tissue, development of targeted drug delivery systems, and strategies aimed at spermatogenic system reconstruction.

Background: The RXFP2 receptor plays a key role in testicular descent, mediating the action of relaxin on gubernaculum development. The T222P polymorphism in the RXFP2 gene has previously been investigated in relation to cryptorchidism, but reported associations have been inconsistent across populations.

Objectives: The aim of this meta-analysis was to assess the association of the T222P variant in the RXFP2 gene with the risk of cryptorchidism and to analyze effect-modifying factors, including population structure and allele frequencies in control groups.

Materials and methods: A systematic literature review was conducted in PubMed, Embase, Web of Science, Scopus, and supplementary sources. Five studies with genotypic data for the T222P variant in case and control populations were selected. Allele and genotype frequencies were calculated, followed by cumulative OR values with 95% confidence intervals. Between-study heterogeneity was assessed using the I² statistic, and moderator analyses (Italy vs. other countries and P allele frequency in controls) as well as leave-one-out sensitivity analyses were performed. Study quality was assessed using the Newcastle-Ottawa Scale.

Results: Carriers of the T222P variant showed a trend toward increased odds of cryptorchidism, with a more pronounced effect observed in Italian cohorts. Heterogeneity was moderate (I² ≈ 50%), and moderator analysis suggested that population differences and P allele frequency in controls may contribute to variability in effect estimates. Sensitivity analyses and alternative genotype models supported the consistency of the findings across analytical approaches.

Discussion: The results support a potential association between the RXFP2 T222P variant and cryptorchidism risk, with population-specific effects likely reflecting underlying genetic background.

Conclusion: The RXFP2 T222P variant may be associated with an increased risk of cryptorchidism, but current evidence remains hypothesis-generating. Further studies in larger, ethnically diverse samples, with full genotyping and functional analysis, are needed to confirm and elucidate the mechanisms underlying the observed effect.

Background: There is growing interest in the relationship between sleep disorders and erectile dysfunction. We present the results from a 2015 follow-up study in relation to the 2007 edition of Epidemiologic Sleep Study (EPISONO), a population-based sleep study conducted in São Paulo, Brazil, and from the 4th edition of EPISONO (2018), with respect to the incidence and prevalence of erectile dysfunction, and the associated risk factors. We hypothesized that the presence of erectile dysfunction would be associated with total testosterone levels and obstructive sleep apnea in both longitudinal and cross-sectional analyses.

Method: The participants underwent polysomnography, and testosterone assays were performed. They also completed a range of health questionnaires. The sample comprised men aged 20‒80 years. In the longitudinal analysis, incidence the (N = 256) and prevalence (N = 300) of erectile dysfunction were calculated, and a generalized estimating equation model was constructed. For the analysis of the data from 2018, prevalence (N = 314), binomial logistic regression, and mediation-moderation models were calculated.

Results: An overall incidence of 10.55% of erectile dysfunction was found in the follow-up, which was higher in men older than 50 years. In the longitudinal model, older age (odds ratio = 1.09), more depression symptoms (odds ratio = 1.05), and low total testosterone concentration (odds ratio = 2.69) were significant predictors of erectile dysfunction. Psychological well-being (World Health Organization Quality of Life) was a predictor of lowered odds of having erectile dysfunction (odds ratio = 0.87). In EPISONO 2018, a 20.06% general prevalence of erectile dysfunction was identified, and this prevalence was higher in age groups over 50 years. The odds of having erectile dysfunction were increased by age (odds ratio = 1.07), and the psychological domain of World Health Organization Quality of Life was associated with lowered odds of having erectile dysfunction (odds ratio = 0.65). Mediation models revealed a statistically significant mediation of apnea‒hypopnea index between the effect of age on total testosterone. The model that included age as the independent variable, apnea‒hypopnea index as a mediator and erectile dysfunction as the outcome resulted in significant effects of age but not apnea‒hypopnea index.

Conclusions: This study highlights the importance of aging, psychological quality of life, testosterone concentration, and depressive symptoms in the context of erectile dysfunction. An association between obstructive sleep apnea and erectile dysfunction was observed, but it was not independent of age. The longitudinal results emphasize that, besides aging, these are modifiable factors that can be the subject of interventions to mitigate the development of erectile dysfunction over time.

Background: Sperm sexing is a technique that enables the selection of offspring sex by sorting spermatozoa based on their sex chromosomes. This technology has gained increasing attention due to its potential applications in both animal breeding and human-assisted reproduction.

Applications: In livestock production, sperm sexing offers substantial economic and genetic benefits, including increased milk production in dairy cattle, improved meat yields in beef cattle, and the prevention of sex-linked genetic diseases. In human reproduction, sex selection techniques may support family balancing and reduce the risk of transmitting hereditary disorders. Commonly used methods, such as flow cytometry and density gradient centrifugation, have been progressively refined to enhance sorting efficiency and accuracy.

Challenges: Despite its advantages, sperm sexing presents technical limitations and raises ethical concerns, particularly regarding its societal implications and the welfare of embryos selected through assisted reproductive technologies.

Conclusions and future perspectives: This review summarizes current sperm sexing methods and their applications in animals and humans, highlights existing challenges, and discusses future directions for technological advancement. The development of safer, more effective, and ethically acceptable approaches may further expand the role of sperm sexing in sustainable animal production and personalized reproductive medicine.

Background: Fluorescence-activated cell sorting (FACS) has emerged as a powerful tool for selecting spermatozoa of a desired population of fluorescent biomarkers, offering potential applications in reproductive biology and agriculture. However, concerns remain regarding sorting-induced physiological alterations that could compromise spermatozoa and/or their ability to capacitate.

Objectives: Our objective was to determine whether catch media composition influences sperm recovery rate and physiological responses post-sort, before and after in vitro capacitation (IVC).

Materials and methods: Five million spermatozoa per treatment were sorted and assessed immediately (0 h) and after 4 h of in vitro capacitation (4 h) using computer-aided sperm analysis (CASA) and Image-Based Flow Cytometry (IBFC). Treatments included six FACS-sorted groups across three media types with BSA or PVA supplementation, and one unsorted control. Functional parameters, including motility, zinc efflux, oxidative stress, membrane remodeling, and mitochondrial activity, were quantitatively assessed.

Results: We found that catch media without PVA or BSA had a near 10%-24% sperm recovery compared to 88%-92% with supplementation (p < 0.05). Immediately post-sort, spermatozoa exhibited minimal alterations relative to controls; however, after 4 h IVC, sorted groups demonstrated significant shifts in zinc efflux (p < 0.05), increased plasma membrane remodeling (p < 0.05), and reduced mitochondrial activity (p < 0.05). While LTX-based media preserved motility, differential responses in membrane integrity and zinc signature distribution were observed between treatments, suggesting that catch media can modulate capacitation outcomes. Notably, mitochondrial and membrane changes became more evident after capacitation incubation, indicating a delayed effect of sorting stress.

Conclusion: These findings highlight the importance of optimizing catch media and incubation conditions to maintain post-sorting sperm functionality and inform the refinement of FACS protocols for agricultural and assisted reproductive technologies. By minimizing sorting-associated stress through media composition, sperm quality and fertilization potential may be better preserved.

Background: Non-obstructive azoospermia (NOA) is a major cause of male infertility, frequently associated with congenital factors. Nevertheless, the genetic underpinnings of NOA remain largely unclear.

Objectives: This study aimed to identify and characterize novel genetic variants contributing to NOA, with a focus on TEX14, a gene critical for intercellular bridge (ICB) formation during meiosis.

Materials/methods: Exome sequencing was performed on genomic DNA from a cohort of 673 patients with NOA, 143 individuals with oligozoospermia, and 100 fertile controls. Potentially pathogenic TEX14 variants were identified and confirmed by Sanger sequencing. Functional analysis, including qPCR and Western blot, was performed to assess TEX14 expression levels in patient and mouse testicular samples and the effects of TEX14 variants on spermatogenesis and ICB formation in both mice and humans.

Results: We identified six novel TEX14 variants in four unrelated infertile Chinese men, including three frameshift mutations (c.2908dupC, p.Arg970Profs5; c.1881dupA, p.Gly628Argfs8; c.1728_1729del, p.Leu577Argfs*58), two missense mutations (c.1121A>G, p.Tyr374Cys; c.865G>A, p.Glu289Lys), and one splicing mutation (c.417+2T>C). To functionally validate the pathogenicity of the frameshift variant c.2908dupC, a mouse model carrying an analogous mutation (Tex14^MT1/MT1) was generated. These mice recapitulated the human NOA phenotype, showing a complete loss of TEX14 expression in the testis. Immunofluorescence and histological analyses revealed that spermatogenesis in Tex14^MT1/MT1 mice was arrested at the zygotene stage due to a complete failure of the ICB formation. Consistent with this, testicular histology from the patient carrying the c.2908dupC variant also showed meiotic arrest at zygotene and absent ICBs. Furthermore, mass spectrometry analysis of purified ICBs indicated that ICB-associated proteins are predominantly involved in RNA processing and ribonucleoprotein complex biogenesis.

Discussion and conclusion: Our results demonstrate that loss-of-function mutations in TEX14 disrupt meiotic ICB formation, leading to zygotene arrest and NOA in both mice and humans, expand the spectrum of pathogenic variants associated with NOA, and establish the essential role of TEX14 in meiotic progression, underscoring the functional importance of TEX14 in male fertility.

Background: Ionizing radiation is widely used in medical diagnostics and cancer therapy, notably radioiodine therapy for thyroid carcinoma. While high or repeated ionizing radiation doses are known to impair male fertility, the impact of clinically relevant single-dose exposures on sperm functional and nuclear integrity is less understood.

Objectives: This study aimed to evaluate the in vitro effects of ionizing radiation doses corresponding to standard therapeutic and diagnostic exposures on human sperm parameters.

Materials and methods: Using a computed tomography scan, ejaculated sperm samples (n = 96) were exposed in vitro to 14 mGy of ionizing radiation (equivalent to single abdominal-pelvic computed tomography scan, n = 35), 70 mGy (five computed tomography scans, n = 39), and 140 mGy (one radioiodine therapy with 3.7 GBq of [131I]iodine, n = 86). For each of the three dose conditions, normozoospermic and non-normozoospermic samples (WHO 2021) were included. Functional (vitality, motility) and nuclear biomarkers (chromatin deprotamination, DNA fragmentation, and sperm telomere length), oxidative stress markers (MDA-TBARS), and capacitation parameters (AMPc concentration, phosphotyrosine profiles, velocity, and acrosome integrity) were assessed against paired controls.

Results: Exposure to 14, 70, and 140 mGy of ionizing radiation induced significant reductions in sperm vitality (p < 0.01 for 14 mGy and p < 0.001 for 70 and 140 mGy), as well as in total and progressive motility (p < 0.001 for 140 mGy). However, sperm vitality and motility values remained within the WHO 2021 reference ranges. Absorbed doses of 70 and 140 mGy increased deprotamination (p < 0.05 and 0.01, respectively). Effect sizes were mostly small, except for a medium to large effect for vitality at the highest dose. DNA fragmentation, telomere length, oxidative stress, and capacitation-associated markers remained unaffected. These effects were consistent across normozoospermic and non-normozoospermic samples.

Discussion and conclusion: Clinically relevant low-doses of ionizing radiation produced modest impairments in sperm functional and chromatin integrity without detectable DNA breakage or oxidative injury. These findings support the relative safety of low-dose therapeutic exposures on mature spermatozoa. This in vitro model also offers a platform for further exploration of sperm radiosensitivity.

Background: Oligoasthenozoospermia is a leading cause of male infertility and has been increasingly associated with the global surge in obesity and exposure to reproductive toxicants. Despite extensive research on each factor individually, their combined pathological effects remain poorly understood.

Objectives: This study aimed to investigate how obesity and reproductive toxicants independently and synergistically impair male reproductive function by establishing and comparing rat models of oligoasthenozoospermia induced by each factor and their combination.

Materials and methods: We constructed three etiologically distinct oligoasthenozoospermia male Sprague-Dawley rat models: a reproductive toxicity model induced by glycosides of Tripterygium wilfordii Hook. f. (GTW), a metabolic dysfunction model induced by a high-fat diet (HFD), and a combined model (HFD + GTW). Animals were randomly assigned and subjected to 12 weeks of treatment. Body weight, metabolic indices, serum sex hormone levels, sperm quality parameters, and histopathological analysis of the testes and epididymis, as well as gut microbiota composition and testicular transcriptome profiles, were systematically evaluated. We also performed quantitative real-time polymerase chain reaction.

Results: Both GTW and HFD independently impaired reproductive function, leading to decreased sperm count and motility, hormonal disturbances, and moderate testicular damage. The combined model exhibited significantly exacerbated reproductive impairment, including extensive spermatogenic cell loss, disrupted testicular architecture, and the lowest sperm quality indices. Multiomics analysis revealed coordinated alterations in gut microbiota composition and testicular transcriptomes, suggesting crosstalk between metabolic and inflammatory signaling pathways. Quantitative real-time polymerase chain reaction confirmed these transcriptomic patterns, showing upregulation of Ahnak, C1r, S1pr1, and Steap4, alongside downregulation of Alkbh7, Tbpl1, Tent5b, and Ldhal6b in the models.

Conclusion: This study successfully establishes reliable rat models that mimic both individual and combined etiologies of oligoasthenozoospermia. The interaction between obesity and GTW-induced reproductive toxicity aggravates testicular injury through metabolic disruption and inflammatory pathways, offering an integrative platform for mechanistic and therapeutic research.

Testicular germ cell tumors (TGCTs) are the most common malignancies in young men. The clinical management largely relies on classical serum tumor markers. However, these markers offer limited sensitivity and specificity, underscoring the need for more reliable biomarkers. In recent years, members of the miR-371∼373 microRNA (miR) cluster, particularly miR-371a-3p, have emerged as superior alternatives, showing excellent diagnostic performance in various clinical settings. While most of the research efforts regarding miR-371∼373 have focused on its clinical utility, recent studies suggest that miR-371a-3p is more than just a diagnostic marker. In this narrative mini-review, we highlight five recent studies all of which provide novel insights into its broader biological roles. The key issues are as follows: (1) the release of miR-371a-3p from cancer cells is accomplished via extracellular vesicles; (2) the miRNA plays an important role in intercellular communication between tumor cells and the tumor microenvironment. (3) There are strong analogies between the human miR-371∼373 cluster and the murine miR-290∼295 cluster, which support the relevance of the gPAK mouse model for preclinical research. (4) miR-371a-3p contributes to cisplatin resistance in TGCTs, and antagomir-based inhibition of this miRNA might be an emerging potential therapeutic strategy. (5) The detection of miR-371a-3p in serum of pregnant women suggests a functional role in feto-maternal signaling. This concise review aims to bridge the gap between clinical and experimental research, positioning miR-371a-3p as both a superior biomarker and a pivotal molecule in TGCT biology with potential therapeutic implications.

Background: Microdissection testicular sperm extraction is the preferred method for sperm retrieval in men with non-obstructive azoospermia. However, the effects of sperm retrieval quantity and freezing on intracytoplasmic sperm injection outcomes remain incompletely understood.

Objectives: To evaluate the impact of sperm quantity and freezing status on fertilization and cumulative live birth rate following intracytoplasmic sperm injection using microdissection testicular sperm extraction spermatozoa in non-obstructive azoospermia patients.

Materials and methods: We retrospectively analyzed 1394 microdissection testicular sperm extraction-intracytoplasmic sperm injection cycles performed between 2017 and 2022 at a single tertiary center. Sperm retrieval yield was stratified into three groups: sufficient sperm count (> 10 spermatozoa/100 fields), low sperm count (6-10/100), and extremely low sperm count (1-5/100). Fertilization rate (two pronuclei) and cumulative live birth rate were compared across sperm retrieval yield and freezing subgroups. Multivariable regression and interaction models assessed the independent and combined effects of sperm quantity and freezing status.

Results: Fertilization and cumulative live birth rate declined significantly with reduced sperm counts (two pronuclei: 53.6%→32.2%; cumulative live birth rate: 49.8%→21.8%; p < 0.001). Frozen spermatozoa yielded comparable outcomes to fresh spermatozoa overall, but in the extremely low sperm count group, frozen spermatozoa were associated with a significantly lower cumulative live birth rate than fresh spermatozoa (12.3% vs. 29.3%; p = 0.015). Interaction analysis confirmed this adverse effect (OR = 0.39; 95% CI 0.16-0.95; p = 0.038). No significant freezing effect was observed in the other groups.

Conclusion: Sperm retrieval quantity is an important predictor of intracytoplasmic sperm injection success in men with non-obstructive azoospermia. Freezing generally does not affect outcomes, but may significantly reduce live birth rates when sperm availability is extremely limited. Prioritizing the use of fresh spermatozoa in such cases may improve clinical outcomes.