Male infertility

A systematic review of interventions to improve male knowledge of fertility and fertility-related risk factors

Male infertility is a global health concern. The effectiveness of interventions developed to improve males' knowledge of fertility regulation and fertility-related risk factors remains unclear. This systematic review aimed to synthesize and evaluate the evidence for these interventions. Four databases were searched from inception to June 2023. Eligible studies examined interventions to increase fertility knowledge among presumed fertile males aged ≥16 years of age. Conference abstracts, protocols and studies without sex-disaggregated results for males were excluded. A narrative synthesis without meta-analysis was performed. A total of 4884 records were identified. Five studies (reported in six publications), all conducted in high-income countries, were included. Two were randomized control trials, and three were experimental studies. Interventions were delivered in person by a health professional (n = 3), online and via a mobile app. All studies showed a significant improvement in knowledge of fertility or fertility-related risk factors from baseline to follow-up. The largest improvement was observed for secondary and vocational students. A moderate, long-term retainment of knowledge was observed at two-year follow-up in one study. Available evidence suggests interventions to improve males' fertility knowledge are effective, particularly for younger, less educated males.

Study of the genomics and transcriptomics profiles of male-infertility genes in human prostate cancer: an in silico analysis

The World Health Organization has considered the infertility as an international public health problem. Infertility affect nearly 1 in 7 couples and male component contributes to 50% of infertility cases. There is a clear link between male infertility and some cancers such as testicular germ cell, prostate and colon cancers. Two possibilities support this finding: 1) Cancer treatments can affect the fertility factors 2) Genetic profile of infertility genes have been altered in cancer patients. Although the previously published researches have mostly focused on the first factor, no article has yet confirmed the role of genetic factors. In this in silico study, we collected the large number of genes (n = 17703) involved in infertility. These genes were collected from NGS panel tests of male infertility and comprehensive literature review or online data base. The Prostate Adenocarcinoma genomic and transcriptomics raw data were downloaded from the cBioPortal Cancer dataset. This included with 494 patients of Prostate Cancer with 494 mutation data, 489 with CNA and 493 with RNA seqV2 data. TCGA RNA-Seq raw data was extracted in R using the cgdsr extension package with a threshold of ±2 relative to normal samples. The observed data showed that male infertility genes have been distributed through the human genome. Among the 17703 analyzed genes of this study, the genomic profile of three genes including OR9Q1, H4C6 and PSG7 were changed approximately in 100% of (n = 493) patients. In most of patients (>98%), genetic alteration was related to change in gene expression. In conclusion, this study showed that the genomic and transcriptomics patterns of some male-infertility genes are notably altered in patients of prostate cancer and suggested a possible role of genetic factors in occurrence of infertility in cancer patients. Our information can be used as a source for the design of genetic database of male-infertility.

Transcriptomic and multi-cytokines profile analysis revealed new insights into the integrating mechanisms of cyanidin-3-O-glucoside on male reproductive damage amelioration

Ulcerative colitis is a public health issue with a rising worldwide incidence. It has been found that current medications for treating UC may cause varying degrees of damage to male fertility. Our previous study demonstrated that cyanidin-3-O-glucoside (C3G) treatment could effectively restore reproductive damage in a mouse model of DSS induced colitis. However, the underlying mechanism of C3G alleviates UC induced male reproductive disorders remain scarce. The aim of this study is to discover the molecular mechanisms of C3G on the amelioration of UC stimulated reproductive disorders. The targeted genes toward UC-induced reproductive injury upon C3G treatments were explored by transcriptomic analysis. Hematological analysis, histopathological examination, and real time transcription-polymerase chain reaction (RT-PCR) analysis were applied for conjoined identification. Results showed that C3G may effectively target for reducing pro-inflammatory cytokine IL-6 in testis through cytokine-cytokine receptor interaction pathway. Transcriptome sequencing found that a series of genetic pathways involved in the protective effects of C3G on male reproduction were identified by gene ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. Further results presented that C3G could effectively restore mRNA expression levels of Ly6a and Col1a1, closely linked with UC induced male reproductive damage pathways. Sufficient results implied that Ly6a and Col1a1 may be treated as the promising therapeutic targets for the mechanism of C3G in treating UC induced reproductive impairment. C3G administration might be an effective dietary supplementation strategy for male reproduction improvement.

Sirt1 m6A modification-evoked Leydig cell senescence promotes Cd-induced testosterone decline

Diminished testosterone levels have been documented as a key factor in numerous male health disorders. Both human and animal studies have consistently demonstrated that cadmium (Cd), a pervasive environmental heavy metal, results in decreased testosterone levels. However, the exact mechanism through which Cd interferes with testosterone synthesis remains incompletely elucidated. This research sought to examine the impact of cellular senescence on Cd-suppressed testosterone synthesis. We also investigated the related m6A modification mechanism. The results demonstrated that Cd (100 mg/L) led to a decrease in testosterone levels, along with downregulated expression of testosterone synthase in C57BL/6 N male mice. Furthermore, Cd significantly increased β-galactosidase staining intensity, senescence-related proteins, and senescence-related secretory phenotypes in mouse testicular Leydig cells. Subsequent investigations revealed that Cd decreased the mRNA and protein levels of NAD-dependent deacetylase Sirtuin-1 (SIRT1) in Leydig cells. Mechanistically, mice treated with resveratrol (50 mg/kg), a specific SIRT1 activator, mitigated Leydig cell senescence and reversed Cd-reduced testosterone levels in mouse testes. These effects were also restored by SIRT1 overexpression in Leydig cells. Additionally, we found that Cd increased the level of methyltransferase enzyme METTL3 and Sirt1 m6A modification in Leydig cells. Mettl3 siRNA effectively restored Cd-enhanced Sirt1 m6A level and reversed Cd-downregulated Sirt1 mRNA expression in Leydig cells. Overall, our findings suggest that Cd exposure inhibits testosterone synthesis via Sirt1 m6A modification-mediated senescence in mouse testes. These results offer an experimental basis for investigating the causes and potential treatments of hypotestosteronemia induced by environmental factors.

Shilajit mitigates chemotherapeutic drug-induced testicular toxicity: Study on testicular germ cell dynamics, steroidogenesis modulation, and Nrf-2/Keap-1 signaling

BACKGROUND

Medications, including chemotherapeutic drugs, contribute to male infertility as external factors by inducing oxidative stress in testicular cells. Shilajit is a naturally occurring bioactive antioxidant used in Ayurvedic medicine to treat a variety of ailments.

OBJECTIVE

This study examines the potential of Shilajit to counteract the negative effects of the chemotherapeutic drug cyclophosphamide (CPA) on testicular germ cell dynamics.

MATERIAL AND METHODS

Male Parkes mice received single intraperitoneal CPA injection (200 mg/kg BW) on day one, followed by daily supplementation of Shilajit (100 and 200 mg/kg BW) for one spermatogenic cycle.

RESULTS

CPA adversely affected testicular germ cell dynamics by inhibiting the conversion of spermatogonia-to-spermatids, altering testicular histoarchitecture, impairing Sertoli cell function and testicular steroidogenesis, and disturbing the testicular oxido-apoptotic balance. Shilajit supplementation restores testicular germ cell dynamics in CPA-exposed mice, as evidenced by improved histoarchitecture of the testis. Shilajit improves testicular daily production and sperm quality by promoting the conversion of spermatogonia (2C) into spermatids (1C), stimulating germ cell proliferation (PCNA), improving Sertoli cell function (N-Cadherin and β-Catenin), and maintaining the Bax/Bcl2 ratio. Additionally, Shilajit enhances testosterone biosynthesis by activating enzymes like 3β-HSD, and 17β-HSD. Shilajit also reduces testicular oxidative stress by increasing antioxidant enzyme activity (SOD) and decreasing lipid peroxidation (LPO). These effects are mediated by upregulation of the antioxidant protein Nrf-2 and downregulation of Keap-1.

CONCLUSION

The findings underscore the potent androgenic and antioxidant characteristics of Shilajit, as well as its ability to enhance fertility in cases of testicular damage caused by chemotherapeutic drugs.

Isoliquiritigenin: a potential drug candidate for the management of erectile dysfunction

OBJECTIVE

This study aimed to assess the erectogenic properties of isoliquiritigenin taking sildenafil (SDF) as the standard.

METHODS

The binding affinity of isoliquiritigenin (ISL) with the erectile marker proteins (endothelial nitric oxide synthase [eNOS] and enzyme phosphodiesterase type 5 [PDE5]) was investigated using Autodock Vina, which was validated using molecular dynamics simulation. Furthermore, the effect of ISL on the eNOS and PDE5 messenger ribonucleic acid (mRNA) expression and the sexual behavior of mice was investigated, along with the assessment of the pharmacokinetics of ISL.

KEY FINDINGS

The results revealed that the binding affinity of ISL-eNOS/PDE5 and SDF-eNOS/PDE5 was in the range of -7.5 to -8.6 kcal/mol. The ISL-eNOS/PDE5 complexes remained stable throughout the 100 ns simulation period. Root mean square deviation, Rg, SASA, hydrogen, and hydrophobic interactions were similar between ISL-eNOS/PDE5 and SDF-eNOS/PDE5. Analysis of mRNA expressions in paroxetine (PRX)-induced ED mice showed that the co-administration of PRX with ISL reduced PDE5 and increased eNOS mRNA expression, similar to the co-administered group (PRX+SDF). The sexual behavior study revealed that the results of PRX+ISL were better than those of the PRX+SDF group. Pharmacokinetic evaluation further demonstrated that ISL possesses drug-like properties.

CONCLUSIONS

The results showed that ISL is equally potent as SDF in terms of binding affinity, specific pharmacological properties, and modulating sexual behavior.

Impact of chronic sleep deprivation on male reproductive health: Insights from testicular and epididymal responses in mice

BACKGROUND

Sleep deprivation (SD) can cause damage to the male reproductive system. However, the duration required for such damage and the specific sequence and severity of damage to the testis and epididymis remain unclear.

OBJECTIVE

To investigate the effects of different durations of SD on different parts of the testis and epididymis caput, corpus, and cauda.

METHODS

Adult ICR mice were randomly assigned to five groups: the SD group (SD for 18 h/day for 1, 2, 3, or 4 weeks), the SD + Vit E group (supplemented with Vit E 50 mg/kg/d during 4 weeks of SD, the SD+NS group (saline supplementation during 4 weeks of SD), the SD + RS group (5 weeks of recovery sleep after 4 weeks of SD), and a normal sleep control (Ctrl) group. Following the interventions, sperm parameters, testicular and epididymal histopathology, inflammatory response, and oxidative stress markers were compared between the groups.

RESULTS

Compared to the Ctrl group, the SD group showed a decrease in sperm motility and concentration from SD 2 W and SD 3 W, respectively. Decreases in sperm concentration and motility were more pronounced in the cauda compared to the caput and corpus. Pathological damage was less severe in the epididymis caput than in the corpus and cauda. After 4 weeks of SD, inflammation and oxidative stress increased in both testes and epididymis. Both sleep recovery and vitamin E supplementation showed significant improvements, though they did not fully reach the level of the Ctrl group.

CONCLUSION

Chronic SD for more than 2 weeks causes varying degrees of damage to the testis, epididymis caput, corpus, and cauda in male mice. This damage is not fully reversible after 5 weeks of sleep recovery and antioxidant stress treatment. These findings help us to identify and prevent SD damage to the male reproduction at an early stage.

Intracerebroventricular injection of spexin stimulates the hypothalamic-pituitary-testicular axis and increases the secretion of male reproductive hormones in rats

BACKGROUND

Male reproductive functions are regulated in the hypothalamic-pituitary-gonadal (HPG) axis. Any problem in this axis would lead to the deterioration of reproductive functions. The present study aimed to investigate the effects of intracerebroventricular (icv) Spexin (SPX) infusion on the HPG axis in detail.

METHODS

40 Wistar albino rats were divided into four groups: control, sham, SPX 30 nmol and SPX 100 nmol (n=10). 30 nmol/1 µl/hour SPX was administered icv to the rats in the SPX 30 nmol group for 7 days, while rats in the SPX 100 nmol group were administered 100 nmol/1 µl/hour SPX. On the 7th day, the rats were decapitated, blood and tissue samples were collected. Serum LH, FSH and testosterone levels were determined with the ELISA method, GnRH mRNA expression level was determined in hypothalamus with the RT-PCR method. Seminiferous tubule diameter and epithelial thickness were determined with the hematoxylin-eosin staining method.

RESULTS

SPX infusion was increased GnRH mRNA expression in the hypothalamus tissue independent of the dose (p<0.05). Serum LH, FSH and testosterone levels in the SPX groups were increased when compared to the control and sham groups independent of the dose (p <0.05). Histological analysis revealed that SPX infusion did not lead to any changes in seminiferous epithelial thickness, while the tubule diameter increased in the SPX groups (p<0.05).

CONCLUSION

The study findings demonstrated that icv SPX infusion stimulated the HPG axis and increased the secretion of male reproductive hormones.

Hydrogen sulfide protects against toxicant acrolein-induced ferroptotic cell death in Sertoli cells

Acrolein (ACR) is a ubiquitous environmental pollutant and byproduct of lipid peroxidation that has been implicated in male infertility. However, the molecular mechanisms underlying ACR-induced toxicity in Sertoli cells remain unclear. Given its role in inducing oxidative stress, we examined whether ferroptosis, an iron-dependent form of regulated cell death, could mediate ACR toxicity in Sertoli cells. We also tested if hydrogen sulfide (H2S), which has antioxidant and ACR detoxifying properties, could protect Sertoli cells from ACR-induced ferroptosis. ACR exposure decreased Sertoli cell viability, increased protein carbonylation and p38 MAPK phosphorylation, indicating oxidative injury. ACR also depleted glutathione (GSH), downregulated the cystine importer SLC7A11, increased intracellular ferrous iron (Fe2+) and lipid peroxidation, suggesting activation of ferroptosis. Consistently, the ferroptosis inhibitor deferoxamine (DFO) markedly attenuates ACR-induced cell death. Further studies revealed that ACR-induced ferroptotic changes were prevented by exogenous H2S and exaggerated by inhibition of endogenous H2S production. Furthermore, H2S also suppressed GPX4 inhibitor RSL3-induced intracellular ACR accumulation and ferroptosis. In summary, our study demonstrates that ACR induces ferroptotic cell death in Sertoli cells, which can be prevented by H2S through multiple mechanisms. Targeting the H2S pathway may represent a therapeutic strategy to mitigate ACR-induced Sertoli cell injury and preserve male fertility.

Thiacloprid impairs reproductive functions of male Wistar rats

Global male infertility correlated to the rise of endocrine-disrupting chemicals, including insecticides, has grown into a pressing problem. Thiacloprid is one of the most commonly used neonicotinoids that accounts for more than 25% of the global pesticide industry. However, its impact on the reproductive system and male fertility has not been fully elucidated. The object of this study was to explore the adverse effects of thiacloprid on male Wistar rats' reproductive system. Thirty healthy male rats were separated into one of three groups: control group, and two groups that were orally administered with low (22.5 mg/kg) and high dose (62.1 mg/kg) of thiacloprid for 56 days. Thiacloprid significantly (p<0.05) reduced body weight and relative testicular weight, as well as sperm quality (count, motility, viability, and morphology), in a dose-dependent manner. THIA-treated groups revealed a large effect (d > 0.8) on semen quality with Cohen's d of (6.57, 8.82), (20.14, 23.54), and (2.81, 9.10) for count, motility, and viability respectively. Meanwhile, the serum testosterone level dropped while the levels of luteinizing and follicle-stimulating hormones increased. 17ꞵ-hydroxy steroid dehydrogenase and 3ꞵ-hydroxy steroid dehydrogenase levels were significantly decreased in a dose-dependent manner. The activity of the tested antioxidant enzymes catalase (CAT), glutathione reduced (GSH), and superoxide dismutase (SOD) exhibited a considerable decrease compared to the control group with a significant elevation in the lipid peroxidation activity as indicated by malondialdehyde (MDA) level. The testicular histology revealed degenerative changes in spermatogenic cells and interstitial tissue. Comet assay revealed DNA fragmentation in treated groups' testicular tissue. Thiacloprid exposure interferes with reproductive function and impairs male Wistar rat fertility. Such harmful consequences may also develop in humans frequently exposed to thiacloprid.

Male Reproduction in Spinal Muscular Atrophy (SMA) and the Potential Impact of Oral Survival of Motor Neuron 2 (SMN2) Pre-mRNA Splicing Modifiers

Spinal muscular atrophy (SMA) is a neuromuscular disease caused by deletions or mutations in the survival of motor neuron 1 (SMN1) gene resulting in reduced levels of SMN protein. SMN protein is produced by cells throughout the body, and evidence suggests that low SMN protein can have systemic implications, including in male reproductive organs. However, a paucity of research exists on this important topic. This article will discuss findings from non-clinical studies on the role of SMN in the male reproductive system; additionally, real-world observational reports of individuals with SMA will be examined. Furthermore, we will review the non-clinical reproductive findings of risdiplam, a small-molecule SMN2 splicing modifier approved for the treatment of SMA, which has widespread distribution in both the central nervous system and peripheral organs. Specifically, the available non-clinical evidence of the effect of risdiplam on male reproductive organs and spermatogenesis is examined. Lastly, the article will highlight available capabilities to assess male fertility as well as the advanced reproductive technologies utilized to treat male infertility. This article demonstrates the need for further research to better understand the impacts of SMA on male fertility and reproduction.

A 2-step remote TUNEL approach for sperm DNA fragmentation assessment. Analysis in donors and patients

OBJECTIVES

Infertility is a disease of the male or female reproductive systems. Male reproductive workup is based on routine semen analysis, although of limited value. The 2021 WHO Manual incorporated Sperm DNA Fragmentation (SDF) assessment, and highlighted the need for individual laboratories to define suitable thresholds. This study aimed to present an alternative to address this issue, determine an SDF cut-off value with fertile donors, and characterize SDF in a patient cohort and their relationship with semen parameters.

STUDY DESIGN

A service unit was established to remotely perform TUNEL assay in a 2 step-process. Semen samples were received at andrology laboratories, subjected to routine semen analysis (WHO, 2010), partially processed and transported to the service unit for SDF evaluation. Using this setting, studies were done in fertile donors (n = 15) to define the cut-off value, and in men undergoing infertility workup (n = 318).

RESULTS

A cut-off value of 9.17 % was determined with the fertile donor cohort. With this cut-off, a 64.46 % abnormal SDF incidence was determined in the patient cohort. SDF negatively correlated with sperm number, vitality and motility, and positively with abnormal morphology and male age (P < 0.05). TUNEL-positive cases depicted lower sperm quality and higher male age (P < 0.05). A similar abnormal SDF incidence was determined among patients with semen abnormalities. Asthenozoospermic and ≥40 years patient samples depicted higher (P < 0.05) SDF than those of the general population. SDF incidence was also high in normozoospermic patients.

CONCLUSIONS

Using a 2-step remote approach with a standardized procedure and an SDF cut-off value established with fertile donors, high SDF incidence in semen samples depicting normal and abnormal quality were identified in men consulting for infertility, highlighting the relevance of its evaluation as part of the male fertility workup.

Plasma Proteomics Analysis of Early Biomarkers for Predicting Female Fecundability: A Nested Case-Control Study

The present study aimed to identify and verify new plasma protein markers to predict the female fecundability level. A nested case-control study was conducted involving couples who participated in the Chinese National Free Preconception Check-up Project. Women who successfully conceive within one year were defined as the high fecundability group, and those unable to conceive were defined as the low fecundability group. In the training cohort, potential protein biomarkers were identified using proteomics technology and were further tested in a validation cohort by the Western blotting assay, enzyme-linked immunosorbent assay, and biochemical tests. Meanwhile, receiver operating characteristic curve analysis were used to evaluate the predictive value. Cox proportional hazard regression analyses were conducted to calculate hazard ratios; restricted cubic spline analysis was used to assess the linear relationship between the the protein level and hazard ratios for fecundability. Pyruvate, a key product of glycolysis, was significantly increased in the high fecundability group (P < 0.01) compared to the low fecundability group, and its area under the curve value was 0.68 (P < 0.05). There was a linear positive dose-response association between the pyruvate level and fecundability possibility (hazard ratios = 1.66, 95% CI: 1.07-2.59, p for trend = 0.025, nonlinearity, p-value = 0.2927).

Role of pyridoxine and oxidative stress in asthenozoospermia

Purpose

Infertility is a worldwide concern, and recent research indicates that vitamin B6 deficiency may play a role in male infertility, primarily by inducing hyperhomocysteinemia and oxidative stress. These processes can have a detrimental effect on semen quality, ultimately affecting male fertility. Here, we aim to evaluate the biochemical status of pyridoxine (vitamin B6) in relation to total glutathione and total antioxidant capacity.

Materials and methods

A case control study samples were collected of asthenozoospermic (n = 63) and normospermic (n = 43) cases, with average men age 30.35 ± 7.03 years old. Semen plasma specimens representing both fertile and sub-fertile men visiting two different secondary care health institute in Irbid province, Jordan. All samples were assessed according to WHO guidelines (2021) and by using spectrophotometry to evaluate the semen plasma levels of vitamin B6, glutathione (GSH) and total antioxidant capacity (TAC).

Results

Our main finding is there is significant positive correlations between the seminal plasma concentration of GSH (p < 0.0001) and TAC (p < 0.0073) are significantly correlated with vitamin B6 deficiency in asthenozoospermia group in comparison to normozoospermia cases. A significant decrease (p < 0.0001) the levels of vitamin B6 in men with asthenozoospermia compared to normozoospermic men (control) with an approximate 80 % percent reduction in the mean levels between groups.

Conclusions

These findings suggest that pyridoxine deficiency may very well alter the GSH system, in so doing affecting the antioxidant defense mechanism against reactive oxygen species to sperm, impacting sperm development and maturation. leading to asthenozoospermia.

Correlation between viral infections in male semen and infertility: a literature review

Infertility affects approximately one-sixth of couples globally, with the incidence of male infertility steadily increasing. However, our understanding of the impact of viral infections on fertility remains limited. This review consolidates findings from previous studies, outlining 40 viruses identified in human semen and summarizing their key characteristics, modes of transmission, and their effects on both the reproductive and endocrine systems. Furthermore, it elucidates potential pathogenic mechanisms and treatment prospects of viruses strongly associated with male infertility. This synthesis will enhance our comprehension of how viral infections influence male reproductive health, offering valuable insights for future research as well as the diagnosis and treatment of infectious infertility.

Interpretable machine learning models for predicting clinical pregnancies associated with surgical sperm retrieval from testes of different etiologies: a retrospective study

BACKGROUND

The relationship between surgical sperm retrieval of different etiologies and clinical pregnancy is unclear. We aimed to develop a robust and interpretable machine learning (ML) model for predicting clinical pregnancy using the SHapley Additive exPlanation (SHAP) association of surgical sperm retrieval from testes of different etiologies.

METHODS

A total of 345 infertile couples who underwent intracytoplasmic sperm injection (ICSI) treatment with surgical sperm retrieval due to different etiologies from February 2020 to March 2023 at the reproductive center were retrospectively analyzed. The six machine learning (ML) models were used to predict the clinical pregnancy of ICSI. After evaluating the performance characteristics of the six ML models, the Extreme Gradient Boosting model (XGBoost) was selected as the best model, and SHAP was utilized to interpret the XGBoost model for predicting clinical pregnancies and to reveal the decision-making process of the model.

RESULTS

Combining the area under the receiver operating characteristic curve (AUROC), accuracy, precision, recall, F1 score, brier score, and the area under the precision-recall (P-R) curve (AP), the XGBoost model has the best performance (AUROC: 0.858, 95% confidence interval (CI): 0.778-0.936, accuracy: 79.71%, brier score: 0.151). The global summary plot of SHAP values shows that the female age is the most important feature influencing the model output. The SHAP plot showed that younger age in females, bigger testicular volume (TV), non-tobacco use, higher anti-müllerian hormone (AMH), lower follicle-stimulating hormone (FSH) in females, lower FSH in males, the temporary ejaculatory disorders (TED) group, and not the non-obstructive azoospermia (NOA) group all resulted in an increased probability of clinical pregnancy.

CONCLUSIONS

The XGBoost model predicts clinical pregnancies associated with testicular sperm retrieval of different etiologies with high accuracy, reliability, and robustness. It can provide clinical counseling decisions for patients with surgical sperm retrieval of various etiologies.

Metabolomics analysis of human spermatozoa reveals impaired metabolic pathways in asthenozoospermia

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.

Further evidence from DNAH12 supports favorable fertility outcomes of infertile males with dynein axonemal heavy chain gene family variants

Male infertility is a major concern affecting reproductive health. Biallelic deleterious variants of most DNAH gene family members have been linked to male infertility, with intracytoplasmic sperm injection (ICSI) being an efficacious way to achieve offspring. However, the association between DNAH12 and male infertility is still limited. Here, we identified one homozygous variant and two compound heterozygous variants in DNAH12 from three infertile Chinese men. Semen analysis revealed severe asthenozoospermia, abnormal morphology, and structure of sperm flagella. Furthermore, the Dnah12 knock-out mouse revealed severe spermatogenesis failure and validated the same male infertility phenotype. Favorable fertility outcomes were achieved through ICSI in three human individuals and Dnah12 knock-out mice. Collectively, our study indicated that biallelic variants of DNAH12 can induce male infertility in both human beings and mice. Notably, evidence from DNAH12 enhanced that ICSI was an optimal intervention to achieve favorable fertility outcomes for infertile males with DNAH gene family variants.

Current treatment for male infertility: an umbrella review of systematic reviews and meta-analyses

This umbrella review aimed to summarize and provide a general evaluation of the effectiveness of current treatments for male infertility and assess the quality of evidence and possible biases. An umbrella review of systematic reviews and meta-analyses available in PubMed, Web of Science, and Scopus, covering studies published up to October 2023, was conducted. Sperm concentration, morphology, and motility were used as endpoints to evaluate the effectiveness of the treatments. Of 2998 studies, 18 published meta-analyses were extracted, yielding 90 summary effects on sperm concentration (n = 36), sperm morphology (n = 26), and sperm motility (n = 28) on 28 interventions. None of the meta-analyses were classified as having low methodological quality, whereas 12 (66.7%) and 6 (33.3%) had high and moderate quality, respectively. Of the 90 summary effects, none were rated high-evidence quality, whereas 53.3% (n = 48), 25.6% (n = 23), and 21.1% (n = 19) were rated moderate, low, and very low, respectively. Significant improvements in sperm concentration, morphology, and motility were observed with pharmacological interventions (N-acetyl-cysteine, antioxidant therapy, aromatase inhibitors, selective estrogen receptor modulators, hormones, supplements, and alpha-lipoic acid) and nonpharmacological interventions (varicocele repair and redo varicocelectomy). In addition, vitamin supplementation had no significant positive effects on sperm concentration, motility, or morphology. Treatments for male infertility are increasingly diverse; however, the current evidence is poor because of the limited number of patients. Further well-designed studies on single treatment and high-quality meta-analysis of intertreatment comparisons are recommended.

Male infertility is associated with differential DNA methylation signatures of the imprinted gene GNAS and the non-imprinted gene CEP41

PURPOSE

To investigate whether the DNA methylation profiles of GNAS(20q13.32), MEST(7q32.2), MESTIT1(7q32.2), IGF2(11p15.5), H19 (7q32.2), and CEP41(7q32.2) genes are related to the transcriptomic and epigenomic etiology of male infertility.

METHODS

The DNA methylation levels of spermatozoa were obtained from fertile (n = 30), oligozoospermic (n = 30), and men with normal sperm count (n = 30). The methylation status of each CpG site was categorized as hypermethylated or hypomethylated. Expression levels of target gene transcripts were determined using real-time PCR.

RESULTS

The oligozoospermia showed a higher frequency of hypermethylation at GNASAS 1st, 3rd, and 5th CpG dinucleotides (66.7%, 73.3%, 73.3%) compared to the fertile group (33.3%, 33.3%, 40%, respectively). The normal sperm count exhibited a higher frequency of hypermethylation at the 3rd CpG of CEP41 (46.7%) than the fertile group (16.7%). Normal sperm count was predicted by CEP41 hypermethylation (OR = 1.750, 95%CI 1.038-2.950) and hypermethylation of both CEP41 and GNASAS (OR = 2.389, 95%CI 1.137-5.021). Oligozoospermia was predicted solely by GNASAS hypermethylation (OR = 2.460, 95%CI 1.315-4.603). In sperms with decreased IGF2 expression in the fertile group, we observed hypomethylation in the 2nd CpG of IGF2 antisense (IFG2AS), and hypermethylation in the 1st, 2nd, and 4th CpGs of H19. No significant relationship was found between IGF2 expression and methylation status of IGF2AS and H19 in infertile groups.

CONCLUSION

The disappearance of the relationship between IGF2 expression and IGF2AS and H19 methylations in the infertile group provides new information regarding the disruption of epigenetic programming during spermatogenesis. A better understanding of sperm GNASAS and CEP41 hypermethylation could advance innovative diagnostic markers for male infertility.

Oral exposure to phenanthrene during gestation disorders endocrine and spermatogenesis in F1 adult male mice

Phenanthrene (Phe), a typical low-molecular-weight polycyclic aromatic hydrocarbon (PAH) of three benzene rings, is one of the most abundant PAHs detected in daily diets. Pregnant women and infants are at great risk of Phe exposure. In the present study, Phe was administered to pregnant mice at a dose of 0, 60, or 600 μg/kg body weight six times, and the F1 male mice showed significant reproductive disorders: the testicular weight and testis somatic index were significantly reduced; the levels of serum testosterone, GnRH and SHBG were increased, while the FSH levels were reduced; histological analysis showed that the amount of Sertoli cells and primary spermatocytes in seminiferous tubules was increased, while the amount of secondary spermatocytes and spermatids were decreased in Phe groups. The protein levels of PCNA and androgen receptor were reduced. Differently expressed genes in the testis screened by RNA sequence were enriched in antioxidant capacity, reproduction et al.. Further biochemical tests confirmed that the antioxidant capacity in the F1 testis was significantly inhibited by treatment with Phe during pregnancy. Those results suggested that gestational Phe exposure disordered hypothalamic-pituitary-gonadal (HPG) hormones on the one hand, and on the other hand reduced testicular antioxidant capacity and further arrested cell cycle in F1 adult male mice, which co-caused the inhibition of spermatogenesis.

Understanding testicular single cell transcriptional atlas: from developmental complications to male infertility

Spermatogenesis is a multi-step biological process where mitotically active diploid (2n) spermatogonia differentiate into haploid (n) spermatozoa via regulated meiotic programming. The alarming rise in male infertility has become a global concern during the past decade thereby demanding an extensive profiling of testicular gene expression. Advancements in Next-Generation Sequencing (NGS) technologies have revolutionized our empathy towards complex biological events including spermatogenesis. However, despite multiple attempts made in the past to reveal the testicular transcriptional signature(s) either with bulk tissues or at the single-cell, level, comprehensive reviews on testicular transcriptomics and associated disorders are limited. Notably, technologies explicating the genome-wide gene expression patterns during various stages of spermatogenic progression provide the dynamic molecular landscape of testicular transcription. Our review discusses the advantages of single-cell RNA-sequencing (Sc-RNA-seq) over bulk RNA-seq concerning testicular tissues. Additionally, we highlight the cellular heterogeneity, spatial transcriptomics, dynamic gene expression and cell-to-cell interactions with distinct cell populations within the testes including germ cells (Gc), Sertoli cells (Sc), Peritubular cells (PTc), Leydig cells (Lc), etc. Furthermore, we provide a summary of key finding of single-cell transcriptomic studies that have shed light on developmental mechanisms implicated in testicular disorders and male infertility. These insights emphasize the pivotal roles of Sc-RNA-seq in advancing our knowledge regarding testicular transcriptional landscape and may serve as a potential resource to formulate future clinical interventions for male reproductive health.

Influence of BMI, Cigarette Smoking and Cryopreservation on Tyrosine Phosphorylation during Sperm Capacitation

Capacitation involves tyrosine phosphorylation (TP) as a key marker. Lifestyle-related factors, such as obesity and smoking, are recognized for their adverse effects on semen quality and male fertility, yet the underlying mechanisms, including their potential impact on TP, remain unclear. Moreover, the effect of sperm cryopreservation on TP at the human sperm population level is unexplored. Flow cytometry analysis of global TP was performed on pre-capacitated, post-capacitated and 1- and 3-hours' incubated fresh and frozen-thawed samples from sperm donors (n = 40). Neither being overweight nor smoking (or both) significantly affected the percentage of sperm showing TP. However, elevated BMI and smoking intensity correlated with heightened basal TP levels (r = 0.226, p = 0.003) and heightened increase in TP after 3 h of incubation (r = 0.185, p = 0.017), respectively. Cryopreservation resulted in increased global TP levels after capacitation but not immediately after thawing. Nonetheless, most donors' thawed samples showed increased TP levels before and after capacitation as well as after incubation. Additionally, phosphorylation patterns in fresh and frozen-thawed samples were similar, indicating consistent sample response to capacitation stimuli despite differences in TP levels. Overall, this study sheds light on the potential impacts of lifestyle factors and cryopreservation on the dynamics of global TP levels during capacitation.

The application of mean number of DNA breakpoints in sperm cryopreservation

Growing concerns over declining male semen quality and rising infertility have shifted attention to male fertility. Sperm cryopreservation emerges as a crucial tool in preserving male fertility, especially for patients who need proactive preservation, such as cancer patients before undergoing radiation or chemotherapy. Although cryopreservation does not directly address infertility, effective preservation can support future fertility. However, the process may compromise sperm DNA integrity. Despite their impairment, damaged sperm often retain vitality and may still have the potential to fertilize an egg. Nonetheless, if damaged sperm fertilize an egg, excessive DNA damage could impede embryo implantation and development, despite the egg's repair capabilities. Consequently, precise detection of sperm DNA damage is crucial and urgent. To better address the issue of sperm DNA damage detection, we have introduced a novel fluorescence biosensor technology known as the TDT/SD Probe. This technology utilizes terminal deoxynucleotidyl transferase (TdT) and strand displacement probes to accurately detect the number of sperm DNA breakage points during the cryopreservation process. Experimental results reveal that the number of sperm DNA breakpoints significantly increases after both sperm vitrification (8.17 × 105) and conventional slow freezing (10.80 × 105), compared to the DNA breakpoints of fresh semen samples (5.19 × 105). However, sperm vitrification has the least impact on sperm breakage points. This research provides innovative means for further optimizing sperm preservation techniques by offering a novel DNA damage detection method, enabling more precise assessment of sperm DNA damage during the freezing process.

A novel murine model mimicking male genital Neisseria species infection using Neisseria musculi†

With ~78 million cases yearly, the sexually transmitted bacterium Neisseria gonorrhoeae is an urgent threat to global public health due to continued emergence of antimicrobial resistance. In the male reproductive tract, untreated infections may cause permanent damage, poor sperm quality, and subsequently subfertility. Currently, few animal models exist for N. gonorrhoeae infection, which has strict human tropism, and available models have limited translatability to human disease. The absence of appropriate models inhibits the development of vital new diagnostics and treatments. However, the discovery of Neisseria musculi, a mouse oral cavity bacterium, offers much promise. This bacterium has already been used to develop an oral Neisseria infection model, but the feasibility of establishing urogenital gonococcal models is unexplored. We inoculated mice via the intrapenile route with N. musculi. We assessed bacterial burden throughout the male reproductive tract, the systemic and tissue-specific immune response 2-weeks postinfection, and the effect of infection on sperm health. Neisseria musculi was found in penis (2/5) and vas deferens (3/5) tissues. Infection altered immune cell counts: CD19+ (spleen, lymph node, penis), F4/80+ (spleen, lymph node, epididymus), and Gr1+ (penis) compared with noninfected mice. This culminated in sperm from infected mice having poor viability, motility, and morphology. We hypothesize that in the absence of testis infection, infection and inflammation in other reproductive is sufficient to damage sperm quality. Many results herein are consistent with outcomes of gonorrhoea infection, indicating the potential of this model as a tool for enhancing the understanding of Neisseria infections of the human male reproductive tract.

Differential Impairment Mechanism of Sperm Production via Induction of miR-34c-Activated Apoptosis and Spermatogenesis Pathway in Diet-Induced Obesity and Resistant Mice and GC-1 Spg Cells

Male reproductive dysfunction is a clinical disease, with a large number of cases being idiopathic. Reproductive disorders have been found in obese (diet-induced obesity and diet-induced obesity-resistant) mice, but the mechanism behind the male reproductive dysfunction between them may be different. The purpose of this study was to explore the possible role and mechanism of miR-34c on sperm production in high-fat-diet-induced obesity-resistant (DIO-R) mice and GC-1 spg cells, which may differ from those in high-fat-diet-induced obesity (DIO) mice. In vivo and in vitro experiments were performed. C57BL/6J mice were fed a high-fat diet for 10 weeks to establish the DIO and DIO-R mouse model. GC-1 spg cells were used to verify the mechanism of miR-34c on sperm production. During in vivo experiments, sperm production damage was found in both DIO and DIO-R male mice. Compared to the control mice, significantly decreased levels of testosterone, LH, activities of acrosome enzyme (ACE), HAse, and activating transcription factor 1 (ATF1) were found in both DIO and DIO-R male mice (p < 0.05). Compared with the control group, the ratio of B-cell lymphoma-2 (Bcl-2)/bcl-2-associated X protein (Bax) in the DIO group was significantly decreased, and the expression level of cleaved caspase-3 was significantly increased (p < 0.05). Compared with the control group, the Bcl-2 protein expression level in the testes of the DIO-R group significantly decreased (p < 0.05). However, the Bax expression level increased. Thus, the Bcl-2/Bax ratio significantly decreased (p < 0.01); however, the factor-related apoptosis (Fas), Fas ligand (FasLG), cleaved caspase-8, caspase-8, cleaved caspase-3, and caspase-3 protein expression levels significantly increased (p < 0.05). Compared with the DIO group, in DIO-R mice, the activities of ACE, ATF1, Bcl-2, and Bcl-2/Bax's spermatogenesis protein expression decreased, while the apoptosis-promoting protein expression significantly increased (p < 0.05). During the in vitro experiment, the late and early apoptotic ratio in the miR-34c over-expression group increased. MiR-34c over-expression enhanced the expression of apoptosis-related proteins Fas/FasLG and Bax/Bcl-2 while inhibiting the expression of ATF1 and the sperm-associated protein in GC-1 spg cells. DIO and DIO-R could harm sperm production. DIO-R could impair sperm production by inducing the miR-34c-activated apoptosis and spermatogenesis pathway, which may be different from that of DIO.

Prevalence of anxiety symptoms in infertile men: a systematic review and meta-analysis

BACKGROUND

Infertility in men causes problems in various aspects of their lives, including personal, family and social life. One of the most important of these problems is anxiety. Anxiety in infertile men can affect their health, quality of life, and response to treatment, highlighting the significance of anxiety in these men. Thus, this systematic review and meta-analysis was conducted to investigate the prevalence of anxiety symptoms in infertile men.

METHODS

To conduct this review study, two researchers independently searched international databases such as PubMed, Cochrane Library, Web of sciences, Scopus, PsyINFO, and the Google scholar search engine in English without considering any time limit until January 2, 2024. Keywords such as "anxiety," "infertility," "prevalence," and "epidemiology" were used, taking into account the specific search method of each database. Using the Newcastle-Ottawa Scale (NOS), the quality of the articles was evaluated by two researchers independently.

RESULTS

In the systematic part of the study, 27 studies were included, and given the variety of measurement tools (8 different tools) used to investigate anxiety symptoms in infertile men, 24 studies were analyzed in five subgroups of tools. The pooled prevalence of anxiety symptoms in infertile men was 21.37% (95% CI: 15.73-27.02). The lowest and highest prevalence of anxiety in infertile men were related to the Beck anxiety inventory (BAI) and Depression Anxiety Stress Scales (DASS), accounting for 7.08% (95% CI: 3.27-10.90) and 34.90% (95%CI: 28.90-40.90) values respectively. This prevalence was 19.80% (95%CI: 9.01-30.59) for the Hospital Anxiety and Depression Scale (HADS), 30.06% (95%CI: 18.59-41.52) for the Spielberger Trait Anxiety Inventory (STAI-T), and 18.52% (95%CI: 7.76-29.29) for the Self-Rating Anxiety Scale (SAS).

CONCLUSION

The results of this systematic review and meta-analysis indicated that the prevalence of anxiety symptoms in infertile men requires special attention to healthcare planning. The healthcare system of different countries should evaluate the symptoms of anxiety in infertile men and take appropriate measures to reduce them according to the culture of the countries. It is recommended that all infertile couples be assessed for anxiety symptoms using a standardized tool during their initial evaluation.

Mechanism of LncRNA Gm2044 in germ cell development

Germ cell development in mammals is a complex physiological process that involves the proliferation of primordial germ cells, meiosis, and the formation of male and female gametes. Long non-coding RNA (lncRNA) is a type of RNA with more than 200 nucleotides that does not code for proteins. A small number of lncRNAs have been shown to participate in spermatogenesis in the testes and in follicular development in the ovaries, but the role of the vast majority of lncRNAs and their molecular mechanisms still need further study. LncRNA Gm2044 was identified as a differentially expressed lncRNA in mouse spermatogenesis by microarray technology. In mouse testis, lncRNA Gm2044 can act as competing endogenous RNA to regulate SYCP1 expression in GC-2 cells derived from mouse spermatocyte cells, and it can also act as a host gene for miR-202 to regulate RBFOX2 protein expression. In female mouse ovaries, lncRNA Gm2044 regulates 17β-estradiol synthesis through the miRNA-138-5p-Nr5a1 pathway or by interacting with EEF2. In addition, studies suggest that lncRNA Gm2044 is also involved in the progression of reproductive system diseases such as male nonobstructive azoospermia. Here, we summarize the roles and molecular mechanisms of lncRNA Gm2044 in male and female gametogenesis and its potential role in some infertility disorders.

Homozygous ACTL9 mutations cause irregular mitochondrial sheath arrangement and abnormal flagellum assembly in spermatozoa and male infertility

PURPOSE

To identify novel variants in ACTL9 and new phenotypes responsible for male infertility.

METHODS

Genomic DNA was extracted from peripheral blood samples for whole-exome sequencing (WES). Computer-assisted sperm analysis (CASA) was used to test the motility of spermatozoa. The ultrastructure of flagella and the mitochondrial sheath were assessed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Immunostaining was used to validate the localization and expression of ACTL9 and ACTL7A. An Actl9-mutated mouse model was used to validate the phenotypes by CASA and TEM.

RESULTS

We identified novel homozygous variants in ACTL9 in two independent Chinese families. Spermatozoa with ACTL9 mutations showed decreased CASA parameters and a higher proportion of spermatozoa with abnormal morphology, exhibiting coiled flagella and a thickened midpiece. The spermatozoa were characterized by chaotic or irregular '9+2' structures and irregular mitochondrial sheath arrangements in the flagellum. Actl9 knock-in mice also showed abnormal CASA parameters and irregular '9+2' structures in flagella.

CONCLUSIONS

Our study expands the mutation spectrum and phenotypic spectrum of ACTL9.

In Vitro Generation of Haploid Germ Cells from Human XY and XXY Immature Testes in a 3D Organoid System

Increasing survival rates of children following cancer treatment have resulted in a significant population of adult survivors with the common side effect of infertility. Additionally, the availability of genetic testing has identified Klinefelter syndrome (classic 47,XXY) as the cause of future male infertility for a significant number of prepubertal patients. This study explores new spermatogonia stem cell (SSC)-based fertility therapies to meet the needs of these patients. Testicular cells were isolated from cryopreserved human testes tissue stored from XY and XXY prepubertal patients and propagated in a two-dimensional culture. Cells were then incorporated into a 3D human testicular organoid (HTO) system. During a 3-week culture period, HTOs maintained their structure, viability, and metabolic activity. Cell-specific PCR and flow cytometry markers identified undifferentiated spermatogonia, Sertoli, Leydig, and peritubular cells within the HTOs. Testosterone was produced by the HTOs both with and without hCG stimulation. Upregulation of postmeiotic germ cell markers was detected after 23 days in culture. Fluorescence in situ hybridization (FISH) of chromosomes X, Y, and 18 identified haploid cells in the in vitro differentiated HTOs. Thus, 3D HTOs were successfully generated from isolated immature human testicular cells from both euploid (XY) and Klinefelter (XXY) patients, supporting androgen production and germ cell differentiation in vitro.

Risk Assessment and Optimization for Pregnancy in Patients with Rheumatic Diseases

Patients with rheumatic diseases frequently operate with incomplete or incorrect information while planning for and experiencing pregnancy, often due to variability in provider care and knowledge. Risk assessment at each stage of pregnancy-pre-conception, during pregnancy, and postpartum-is focused on reducing maternal and neonatal complications. This review aims to compile updated, evidence-based guidance on how to minimize risk factors contributing to adverse pregnancy outcomes (APOs). Mitigation of known causes of infertility, appropriate testing and monitoring, achieving low disease activity on pregnancy-safe disease-modifying antirheumatic drugs (DMARDs) prior to conception, controlling hypertension (a frequent comorbidity among patients with certain rheumatic diseases), and the use of appropriate adjunctive medications (such as low-dose aspirin when preeclampsia risk is high) can optimize fertility and prevent adverse maternal and neonatal outcomes.

Reproductive toxicity and related mechanisms of micro(nano)plastics in terrestrial mammals: Review of current evidence

Micro(nano)plastics (MNPs) have been detected in various ecological environments and are widely used due to their stable properties, raising widespread concern about their potential human reproductive toxicity. Currently, infertility affects approximately 10-30% of couples of reproductive age globally. MNPs, as environmental pollutants, have been shown to exhibit reproductive toxicity through intrinsic mechanisms or as carriers of other hazardous substances. Numerous studies have established that MNPs of varying sizes and types can penetrate biological barriers, and enter tissues and even organelles of organisms through four main routes: dietary ingestion, inhalation, dermal contact, and medical interventions. However, historical research on the toxic effects of MNPs on reproduction mainly focused on lower and aquatic species. We conducted an inclusive review of studies involving terrestrial mammals, revealing that MNPs can induce reproductive toxicity via various mechanisms such as oxidative stress, inflammation, fibrosis, apoptosis, autophagy, disruption of intestinal flora, endocrine disruption, endoplasmic reticulum stress, and DNA damage. In terrestrial mammals, reproductive toxicity predominantly manifests as disruption in the blood-testis barrier (BTB), impaired spermatogenesis, sperm malformation, sperm DNA damage, reduced sperm fertilizing capacity, compromised oocyte maturation, impaired follicular growth, granulosa cell apoptosis, diminished ovarian reserve function, uterine and ovarian fibrosis, and endocrine disruption, among other effects. Furthermore, MNPs can traverse the maternal-fetal interface, potentially impacting offspring reproductive health. To gain a comprehensive understanding of the potential reproductive toxicity and underlying mechanisms of MNPs with different sizes, polymer types, shapes, and carried toxins, as well as to explore effective protective interventions for mitigating reproductive damage, further in-depth animal studies, clinical trials, and large-scale epidemiological studies are urgently required.

The therapeutic effect and metabolic mechanism analysis of Guilingji on idiopathic oligo-asthenoteratozoospermia

Introduction

Guilingji, a famous traditional Chinese medicine (TCM) formula, has been used to combat aging and male sexual dysfunction in China for centuries. To date, there has been little evidence-based clinical research on the use of Guilingji to treat idiopathic oligo-asthenoteratozoospermia (OAT), and the therapeutic mechanism from a metabolic perspective needs to be investigated further.

Methods

This was a multicenter, double-blind, randomized controlled clinical study of 240 patients with idiopathic OAT recruited from four hospitals between January 2020 and January 2022. Patients were randomly assigned in a 1꞉1 ratio to receive oral Guilingji capsules or placebo for 12 weeks. The total progressive motile sperm count (TPMSC) was considered the primary outcome, and the other sperm parameters, seminal plasma parameters and serum hormones were considered the secondary outcome. A nontargeted metabolomics analysis of serum from OAT patients before and after Guilingji administration was performed by HPLC-MS to identify key metabolites. Furthermore, we used a rat model to show spermatogenesis phenotypes to validate the effect of the key metabolites screened from the patients.

Results

At weeks 4, 8 and 12, TPMSC and other sperm parameters were significantly improved in the Guilingji group compared with the placebo group (P < 0.05 for all comparisons). At week 4, superoxide dismutase (SOD) and acrosomal enzyme activity of seminal plasma were significantly elevated in the Guilingji group compared with the placebo group, while reactive oxygen species (ROS) levels were significantly reduced (P < 0.05). Lactate dehydrogenase-X (LDHX) levels appeared to be significantly increased after 12 weeks continuous medication compared with Placebo group (P = 0.032). The metabolomics analysis of serum from OAT patients before and after Guilingji administration showed that the glucose-6-phosphate (G6P) concentration in patients' serum was significantly elevated after Guilingji treatment. Compared to the control, when Kidney-Yang deficiency model rats were treated with Guilingji or its key intermediate metabolite G6P, their sperm concentration and spermatozoic activity were improved similarly, and their structural damage of rat's testicular and epididymal tissues were recovered.

Conclusion

This study provided valuable clinical evidence for the utility of Guilingji as a treatment for OAT. These findings thus demonstrate that G6P is involved in the therapeutic mechanism of Guilingji in OAT treatment based on clinical and rat intervention studies.

Testicular volume is a noninvasive predictor of sperm retrieval failure in idiopathic nonobstructive azoospermia

We investigated the prognostic importance of noninvasive factors in predicting sperm retrieval failure in idiopathic nonobstructive azoospermia (iNOA). We studied 193 patients with nonobstructive azoospermia who underwent microsurgical testicular sperm extraction. The Chi-square test and Mann-Whitney U tests for clinical parameters and seminiferous tubule distribution were used for between-group comparisons. A logistic regression analysis was conducted to identify predictors of retrieval failure. Area under the receiver operating characteristic curve for each variable was evaluated, and the net clinical benefit was calculated using a clinical decision curve. Patients with iNOA had a lower sperm retrieval rate than those with known causes. Moreover, testicular volume was an independent factor affecting sperm extraction outcomes (odds ratio = 0.79, P < 0.05). The testicular volume cut-off value was 6.5 ml (area under the curve: 0.694). The patients with iNOA were categorized into two groups on the basis of the distribution of seminiferous tubules observed. The sperm retrieval rate and testicular volume were significantly different between the groups with a uniform or heterogeneous tubule distribution. There was also a significant association between a uniform tubule distribution and testicular volume. In conclusion, a testicular volume of more than 6.5 ml effectively predicts microsurgical testicular sperm extraction failure due to a uniform tubule distribution in patients with iNOA.

Idiopathic secondary azoospermia occurrence in men with oligospermia over time

PURPOSE

To investigate the occurrence of idiopathic secondary azoospermia (ISA) in men with oligospermia over time and identify risk factors for ISA in this population.

METHODS

This was a retrospective cohort study conducted in a university-affiliated male infertility clinic. A total of 1056 oligospermic men (concentration < 15 million/ml (M/ml) and no azoospermia) with at least two SA done between 2000 and 2019 were included. The primary outcome was the occurrence of ISA by oligospermia severity.

RESULTS

In the entire cohort, 31 patients (2.9%) eventually became azoospermic with time. The ≤ 1 M/ml extremely severe oligospermia (ESO) group (283 patients) had significantly higher rates of ISA in each time period compared to the 1-5 M/ml severe oligospermia (SO) (310 patients) and 5-15 M/ml mild oligospermia (MO) (463 patients) groups (p < 0.05 for all comparisons), with rates of 21.1% in the ESO, 4.8% in the SO, and 0% in the MO group (p = 0.02) after 3-5 years, reaching 32% after 5 years in the ESO group compared to no cases in the other two groups (p = 0.006). Parameters shown to predict ISA were initial concentration < 1 M/ml (OR 22.12, p < 0.001) and time interval of > 3 and 5 years (OR 4.83 and 6.84, p = 0.009 and < 0.001, respectively), whereas testosterone levels were negatively associated with ISA (OR 0.88, p = 0.03).

CONCLUSIONS

Men with ≤ 1 M/ml, especially those with low testosterone levels, have a dramatically increased chance of becoming azoospermic with time. Therefore, sperm banking should be recommended in these cases. Men with a sperm concentration above 1 M/ml have low chances of becoming azoospermic, even after 3 or more years.

Genetic Insights into Azoospermia and Severe Oligozoospermia: Discovering Seven SNPs through GWAS and In Silico Analysis

Azoospermia and severe oligozoospermia represent the most extreme forms of male infertility. Despite their prevalence, the genetic foundations of these conditions are not well understood, with only a limited number of genetic factors identified so far. This study aimed to identify single-nucleotide polymorphisms (SNPs) linked to both azoospermia and severe oligozoospermia. We conducted a genome-wide association study (GWAS) involving 280 Greek males with normal semen parameters and 85 Greek males diagnosed with either azoospermia or severe oligozoospermia. Following rigorous quality control measures, our analysis identified seven SNPs associated with azoospermia/severe oligozoospermia. An in silico functional annotation was subsequently used to further investigate their role. These SNPs, found in regions not previously associated with male reproductive disorders, suggest novel genetic pathways that may contribute to these forms of infertility and pave the way for future studies. Additionally, this study sheds light on the significant role of noncoding RNAs in the pathogenesis of male infertility, with three of the identified SNPs situated in long intergenic non-coding RNAs (lincRNAs). Our findings highlight the intricate genetic landscape of azoospermia and severe oligozoospermia, underlining the necessity for more detailed studies to fully grasp the underlying mechanisms and their potential for informing diagnostic and therapeutic strategies.

Deficiency of MFSD6L, an acrosome membrane protein, causes oligoasthenoteratozoospermia in humans and mice

Oligoasthenoteratozoospermia is an important factor affecting male fertility and has been found to be associated with genetic factors. However, there are still a proportion of oligoasthenoteratozoospermia cases that cannot be explained by known pathogenic genetic variants. Here, we perform genetic analyses and identify bi-allelic loss-of-function variants of MFSD6L from an oligoasthenoteratozoospermia-affected family. Mfsd6l knock-out male mice also present male subfertility with reduced sperm concentration, motility, and deformed acrosomes. Further mechanistic analyses reveal that MFSD6L, as an acrosome membrane protein, plays an important role in the formation of acrosome by interacting with the inner acrosomal membrane protein SPACA1. Moreover, poor embryonic development is consistently observed after intracytoplasmic sperm injection treatment using spermatozoa from the MFSD6L-deficient man and male mice. Collectively, our findings reveal that MFSD6L is required for the anchoring of sperm acrosome and head shaping. The deficiency of MFSD6L affects male fertility and causes oligoasthenoteratozoospermia in humans and mice.

Oxidative Stress-Associated Male Infertility: Current Diagnostic and Therapeutic Approaches

Infertility is a prevalent global issue affecting approximately 17.5% of adults, with sole male factor contributing to 20-30% of cases. Oxidative stress (OS) is a critical factor in male infertility, disrupting the balance between reactive oxygen species (ROS) and antioxidants. This imbalance detrimentally affects sperm function and viability, ultimately impairing fertility. OS also triggers molecular changes in sperm, including DNA damage, lipid peroxidation, and alterations in protein expression, further compromising sperm functionality and potential fertilization. Diagnostic tools discussed in this review offer insights into OS markers, antioxidant levels, and intracellular ROS concentrations. By accurately assessing these parameters, clinicians can diagnose male infertility more effectively and thus tailor treatment plans to individual patients. Additionally, this review explores various treatment options for males with OS-associated infertility, such as empirical drugs, antioxidants, nanoantioxidants, and lifestyle modifications. By addressing the root causes of male infertility and implementing targeted interventions, clinicians can optimize treatment outcomes and enhance the chances of conception for couples struggling with infertility.

Detection of AZF microdeletions and analysis of reproductive hormonal profiles in Hainan men undergoing assisted reproductive technology

BACKGROUND

Male infertility has become a global health problem, and genetic factors are one of the essential causes. Y chromosome microdeletion is the leading genetic factor cause of male infertility. The objective of this study is to investigate the correlation between male infertility and Y chromosome microdeletions in Hainan, the sole tropical island province of China.

METHODS

We analyzed the semen of 897 infertile men from Hainan in this study. Semen analysis was measured according to WHO criteria by professionals at the Department of Reproductive Medicine, the First Affiliated Hospital of Hainan Medical University, where samples were collected. Y chromosome AZF microdeletions were confirmed by detecting six STS markers using multiple polymerase chain reactions on peripheral blood DNA. The levels of reproductive hormones, including FSH, LH, PRL, T, and E2, were quantified using the enzyme-linked immunosorbent assay (ELISA).

RESULTS

The incidence of Y chromosome microdeletion in Hainan infertile men was 7.13%. The occurrence rate of Y chromosome microdeletion was 6.69% (34/508) in the oligozoospermia group and 7.71% (30/389) in the azoospermia group. The deletion of various types in the AZF subregion was observed in the group with azoospermia, whereas no AZFb deletion was detected in the oligozoospermia group. Among all patients with microdeletions, the deletion rate of the AZFc region was the higher at 68.75% (44 out of 64), followed by a deletion rate of 6.25% (4 out of 64) for the AZFa region and a deletion rate of 4.69% (3 out of 64) for the AZFb region. The deletion rate of the AZFa region was significantly higher in patients with azoospermia than in patients with oligozoospermia (0.51% vs. 0.39%, p < 0.001). In comparison, the deletion rate of the AZFc region was significantly higher in patients with oligozoospermia (3.08% vs. 6.30%, p < 0.001). Additionally, the AZFb + c subregion association deletion was observed in the highest proportion among all patients (0.89%, 8/897), followed by AZFa + b + c deletion (0.56%, 5/897), and exclusively occurred in patients with azoospermia. Hormone analysis revealed FSH (21.63 ± 2.01 U/L vs. 10.15 ± 0.96 U/L, p = 0.001), LH (8.96 ± 0.90 U/L vs. 4.58 ± 0.42 U/L, p < 0.001) and PRL (263.45 ± 21.84 mIU/L vs. 170.76 ± 17.10 mIU/L, p = 0.002) were significantly increased in azoospermia patients with microdeletions. Still, P and E2 levels were not significantly different between the two groups.

CONCLUSIONS

The incidence of AZF microdeletion can reach 7.13% in infertile men in Hainan province, and the deletion of the AZFc subregion is the highest. Although the Y chromosome microdeletion rate is distinct in different regions or populations, the regions mentioned above of the Y chromosome may serve an indispensable role in regulating spermatogenesis. The analysis of Y chromosome microdeletion plays a crucial role in the clinical assessment and diagnosis of male infertility.

pH Homeodynamics and Male Fertility: A Coordinated Regulation of Acid-Based Balance during Sperm Journey to Fertilization

pH homeostasis is crucial for spermatogenesis, sperm maturation, sperm physiological function, and fertilization in mammals. HCO3- and H+ are the most significant factors involved in regulating pH homeostasis in the male reproductive system. Multiple pH-regulating transporters and ion channels localize in the testis, epididymis, and spermatozoa, such as HCO3- transporters (solute carrier family 4 and solute carrier family 26 transporters), carbonic anhydrases, and H+-transport channels and enzymes (e.g., Na+-H+ exchangers, monocarboxylate transporters, H+-ATPases, and voltage-gated proton channels). Hormone-mediated signals impose an influence on the production of some HCO3- or H+ transporters, such as NBCe1, SLC4A2, MCT4, etc. Additionally, ion channels including sperm-specific cationic channels for Ca2+ (CatSper) and K+ (SLO3) are directly or indirectly regulated by pH, exerting specific actions on spermatozoa. The slightly alkaline testicular pH is conducive to spermatogenesis, whereas the epididymis's low HCO3- concentration and acidic lumen are favorable for sperm maturation and storage. Spermatozoa pH increases substantially after being fused with seminal fluid to enhance motility. In the female reproductive tract, sperm are subjected to increasing concentrations of HCO3- in the uterine and fallopian tube, causing a rise in the intracellular pH (pHi) of spermatozoa, leading to hyperpolarization of sperm plasma membranes, capacitation, hyperactivation, acrosome reaction, and ultimately fertilization. The physiological regulation initiated by SLC26A3, SLC26A8, NHA1, sNHE, and CFTR localized in sperm is proven for certain to be involved in male fertility. This review intends to present the key factors and characteristics of pHi regulation in the testes, efferent duct, epididymis, seminal fluid, and female reproductive tract, as well as the associated mechanisms during the sperm journey to fertilization, proposing insights into outstanding subjects and future research trends.

A novel missense mutation of CCDC34 causes male infertility with oligoasthenoteratozoospermia in a consanguineous Pakistani family

ABSTRACT

Male infertility is a worldwide health issue, affecting 8%-12% of the global population. Oligoasthenoteratozoospermia (OAT) represents a severe type of male infertility, characterized by reduced sperm count and motility and an increased frequency of sperm with aberrant morphology. Using whole-exome sequencing, this study identified a novel missense mutation (c.848C>A, p.A283E) in the coiled-coil domain-containing 34 gene (CCDC34) in a consanguineous Pakistani family. This rare mutation was predicted to be deleterious and to affect the protein stability. Hematoxylin and eosin staining of spermatozoa from the patient with OAT revealed multiple morphological abnormalities of the flagella and transmission electron microscopy indicated axonemal ultrastructural defects with a lack of outer dynein arms. These findings indicated that CCDC34 plays a role in maintaining the axonemal ultrastructure and the assembly or stability of the outer dynein arms, thus expanding the phenotypic spectrum of CCDC34 missense mutations.

Sperm epigenetics and male infertility: unraveling the molecular puzzle

BACKGROUND

The prevalence of infertility among couples is estimated to range from 8 to 12%. A paradigm shift has occurred in understanding of infertility, challenging the notion that it predominantly affects women. It is now acknowledged that a significant proportion, if not the majority, of infertility cases can be attributed to male-related factors. Various elements contribute to male reproductive impairments, including aberrant sperm production caused by pituitary malfunction, testicular malignancies, aplastic germ cells, varicocele, and environmental factors.

MAIN BODY

The epigenetic profile of mammalian sperm is distinctive and specialized. Various epigenetic factors regulate genes across different levels in sperm, thereby affecting its function. Changes in sperm epigenetics, potentially influenced by factors such as environmental exposures, could contribute to the development of male infertility.

CONCLUSION

In conclusion, this review investigates the latest studies pertaining to the mechanisms of epigenetic changes that occur in sperm cells and their association with male reproductive issues.

Unraveling the Genetic Basis of Combined Deafness and Male Infertility Phenotypes through High-Throughput Sequencing in a Unique Cohort from South India

The co-occurrence of sensorineural hearing loss and male infertility has been reported in several instances, suggesting potential shared genetic underpinnings. One such example is the contiguous gene deletion of CATSPER2 and STRC genes, previously associated with deafness-infertility syndrome (DIS) in males. Fifteen males with both hearing loss and infertility from southern India after exclusion for the DIS contiguous gene deletion and the FOXI1 gene mutations are subjected to exome sequencing. This resolves the genetic etiology in four probands for both the phenotypes; In the remaining 11 probands, two each conclusively accounted for deafness and male infertility etiologies. Genetic heterogeneity is well reflected in both phenotypes. Four recessive (TRIOBP, SLC26A4, GJB2, COL4A3) and one dominant (SOX10) for the deafness; six recessive genes (LRGUK, DNAH9, ARMC4, DNAH2, RSPH6A, and ACE) for male infertility can be conclusively ascribed. LRGUK and RSPH6A genes are implicated earlier only in mice models, while the ARMC4 gene is implicated in chronic destructive airway diseases due to primary ciliary dyskinesia. This study would be the first to document the role of these genes in the male infertility phenotype in humans. The result suggests that deafness and infertility are independent events and do not segregate together among the probands.

Intrauterine insemination: prognostic factors

OBJECTIVE

To evaluate the impact of possible maternal and paternal prognostic factors and ovarian stimulation protocols on clinical pregnancy and live birth rates in intrauterine insemination (IUI) cycles.

METHODS

Retrospective observational study of 341 IUI cycles performed from January 2016 to November 2020 at the Assisted Reproduction Service of the Clinics Hospital of the Ribeirão Preto Medical School, University of São Paulo. Clinical pregnancy and live birth rates and their potential prognostic factors were evaluated. Wilcoxon's non-parametric test was used to compare quantitative variables, and the chi-square test to compare qualitative variables, adopting a significance level of p<0.05. A logistic regression model was performed to verify which exploratory variables are predictive factors for pregnancy outcome.

RESULTS

The ovulation induction protocol using gonadotropins plus letrozole (p=0.0097; OR 4.3286, CI 1.3040 - 14.3684) and post-capacitation progressive sperm ≥ 5million/mL (p=0.0253) showed a statistically significant correlation with the live birth rate. Female and male age, etiology of infertility, obesity, multifollicular growth, endometrial thickness ≥ 7 mm, and time between human chorionic gonadotropin administration and IUI performance were not associated with the primary outcomes. In the group of patients with ideal characteristics (women aged< 40 years, BMI < 30 kg/m2, antral follicle count ≥ 5, partner aged< 45 years, and post-capacitation semen with progressive spermatozoa ≥ 5 million/mL), the rate of clinical pregnancy was 14.8%, while that of live birth, 9.9%.

CONCLUSIONS

In this study, the ovulation induction protocol with gonadotropins plus letrozole and post-capacitation progressive sperm ≥ 5 million/mL were the only variables that significantly correlated with intrauterine insemination success.

Obesity and male fertility disorders

Often associated with obesity, male infertility represents a widespread condition that challenges the wellbeing of the couple. In this article, we provide a comprehensive and critical analysis of studies exploring the association between obesity and male reproductive function, to evaluate the frequency of this association, and establish the effects of increased body weight on conventional and biofunctional sperm parameters and infertility. In an attempt to find possible molecular markers of infertility in obese male patients, the numerous mechanisms responsible for infertility in overweight/obese patients are reviewed in depth. These include obesity-related functional hypogonadism, insulin resistance, hyperinsulinemia, chronic inflammation, adipokines, irisin, gut hormones, gut microbiome, and sperm transcriptome. According to meta-analytic evidence, excessive body weight negatively influences male reproductive health. This can occurr through a broad array of molecular mechanisms. Some of these are not yet fully understood and need to be further elucidated in the future. A better understanding of the effects of metabolic disorders on spermatogenesis and sperm fertilizing capacity is very useful for identifying new diagnostic markers and designing therapeutic strategies for better clinical management of male infertility.

Possible Impact of Human β-defensin 1 on sperm motility in infertile men with abnormal sperm parameters

Human β-defensins and interleukins may be auxiliary in sperm maturation. This cross-sectional study aimed to evaluate the expression of Human β-defensins 1 and 2, interleukins (ILs)- 10 and -18 genes in sperm, as well as seminal plasma levels of these two cytokines in subfertile men with different types of sperm abnormalities compared to those with normozoospermic men. Participants were separated into two experimental groups: the control group (n = 25) and the group with sperm abnormalities (SA) (n = 45). SA participants were further subdivided into the following groups with n = 15 individuals each: Teratozoospermia (T), Asthenoteratozoospermia (AT), and Oligoasthenoteratozoospermia (OAT) groups. The quantitative real-time polymerase chain reaction was used to quantify the mRNA levels of hBDs 1 and 2, IL-10, and IL-18 in sperm. The seminal plasma concentrations of IL-10 and IL-18 were measured by using the enzyme-linked immunosorbent assay technique. The mRNA expression of hBD-1 and IL-10 showed a significant decrease in the OAT compared to the controls (P < 0.0001 and P = 0.02, respectively). The lowest seminal plasma concentration of IL-10 belonged to the OAT (P = 0.04). ROC curve analysis showed a sensitivity, specificity, and cutoff value of 82.35%, 86.67%, and 0.63 for hBD-1 levels, respectively. A positive and significant correlation was found between hBD-1 expression and sperm motility and IL-10 expression rate and normal sperm morphology.Therefore, hBD-1 could be considered as the alternative biomaterial to pre-treatments of infertile men with abnormal sperm parameters, specifically OAT men, which led to improving the assisted reproduction success rate.

Ameliorative effects of zinc and vitamin E against phthalates-induced reproductive toxicity in male rats

OBJECTIVE

Phthalates (PEs) could cause reproductive harm to males. A mixture of three widely used PEs (MPEs) was used to investigate the ameliorative effects of zinc (Zn) and vitamin E (VE) against male reproductive toxicity.

METHODS

Fifty male SD rats were randomly divided into five groups (n = 10). Rats in MPEs group were orally treated with 160 mg/kg/d MPEs, while rats in MPEs combined Zn and/or VE groups were treated with 160 mg/kg/d MPEs plus 25 mg/kg/d Zn and/or 25 mg/kg/d VE. After intervention for 70 days, it's was measured of male reproductive organs' weight, histopathological observation of sperms and testes, serum hormones, PIWI proteins and steroidogenic proteins.

RESULTS

Compared with control, anogenital distance, testes weight, epididymides weight, and sex hormones were significantly decreased, while the sperm malformation rate was markedly increased in MPEs group (p < .05); the testicular tissues were injured in MPEs group with disordered and decreased spermatids, and arrested spermatogenesis. PIWIL1, PIWIL2, StAR, CYP11A1 and CYP19A1 were down-regulated in MPEs group (p < .05). However, the alterations of these parameters were restored in MPEs combined Zn and/or VE groups (p < .05).

CONCLUSION

Zn and/or VE improved steroid hormone metabolism, and inhibited MPEs' male reproductive toxicity.

Changes in Sperm Parameters with Time in Men with Normal and Abnormal Baseline Semen Analysis

The association between paternal age and sperm quality in the population level has been previously studied. Only limited data exists regarding the intra-personal variations in semen parameters among fertile and infertile men over time. We aimed to assess trends over time in semen parameters among men with normal and abnormal baseline sperm parameters and investigate potential risk factors for sperm quality deterioration. This retrospective cohort study was conducted at a university-affiliated medical center in vitro fertilization (IVF) unit. Patients with at least two semen analyses (SA) performed > 1 year apart, with the last SA done between 2017 and 2021, were included. The study consisted of two main analyses-comparison of intra-patient's sperm parameters changes in men with normal and abnormal baseline SA (BSA) and analysis of risk factors for developing abnormal semen parameters over time in men who had normal BSA parameters. This study included a total of 902 men assessed for infertility with normal and abnormal BSA. The average time interval between tests was 1015 days (range 366-7709 days). Among individuals with normal BSA, there was a mild decline in most parameters-concentration (- 6.53 M/ml), motility (- 7.74%), and total motile count (TMC) (- 21.80 M) (p < 0.05 for all parameters). In contrast, a slight improvement in most parameters, except for concentration, was noted in men with abnormal BSA-volume (+ 0.21 ml), motility (+ 8.72%), and TMC (+ 14.38 M) (p < 0.05 for all parameters). Focusing on men with normal BSA, 33.5% of individuals developed abnormality in one or more of their sperm parameters over time, within a mean time of 1013 ± 661 days. We also found that only time between tests emerged as an independent prognostic factor for the development of abnormal SA later. Interestingly, sperm deterioration in participants in their third, fourth, and fifth decades of life with normal initial semen analysis was similar. Our study provides evidence of a decline in semen quality over time in individuals with normal BSA, in contrast to men with abnormal BSA. Longer time intervals between tests independently increase the risk of sperm abnormalities.

Lower malathion concentrations reduce testosterone biosynthesis by Leydig TM3 cells in vitro by altering cellular redox profile and inducing oxidative damage

Malathion is an organophosphate pesticide used in agriculture and control of the Aedes aegypti mosquito. As previous reports have indicated the potential of malathion to compromise testosterone production in in vivo models, the objective of this study was to elucidate the mechanisms underlying the impairment of Leydig cell function, considering its critical role in male reproductive function. To this end, murine Leydig TM3 cells were exposed to concentrations of 1, 10, 100 or 1000 μM malathion for 24 h for evaluation of the compound on cell viability. Subsequently, concentrations of 1, 10, and 100 μM malathion were employed for a 24-h period to assess testosterone biosynthesis, levels of cytokines IL-1β, IL-6, IL-10, and TNF-α, as well as the redox profile. Malathion exerted a concentration-dependent impact on cell viability. Notably, the lower concentrations of malathion (1 and 10 μM) were found to impair testosterone biosynthesis in TM3 cells. While there were changes in IL-1 and TNF-α levels at specific concentrations, no direct correlation with altered hormone production was established. Our investigation revealed that varied malathion concentrations induced oxidative stress by increase in superoxide anion and a compensatory rise in antioxidants. In conclusion, the observed changes in the oxidative profile of TM3 cells were linked to functional impairment, evidenced by reduced testosterone biosynthesis at lower malathion concentrations.

Gut-Derived Exosomes Mediate the Microbiota Dysbiosis-Induced Spermatogenesis Impairment by Targeting Meioc in Mice

Diseases like obesity and intestinal inflammation diseases are accompanied by dysbiosis of the gut microbiota (DSGM), which leads to various complications, including systemic metabolic disorders. DSGM reportedly impairs the fertility of male mice; however, the regulatory mechanism is unclear. Exosomes are molecular mediators of intercellular communication, but the regulation of spermatogenesis by non-reproductive tissue-originated exosomes remains unknown. The present study shows that DSGM altered the miRNA expression profile of mouse circulating exosomes and impaired spermatogenesis. Moreover, the single-cell sequencing results indicate that circulating exosomes from mice with DSGM impaired spermatogenesis, while circulating exosomes from wild mice improved spermatogenesis by promoting meiosis. Further study demonstrates that DSGM leads to abnormal upregulation of miR-211-5p in gut-derived circulating exosomes, which inhibited the expression of meiosis-specific with coiled-coil domain (Meioc) in the testes and impaired spermatogenesis by disturbing meiosis process. In summary, this study defines the important role of gut-derived exosomes in connecting the "gut-testis" axis.