USP11 regulates proliferation and apoptosis of human spermatogonial stem cells via HOXC5-mediated canonical WNT/ß-catenin signaling pathway.

Spermatogonial stem cells (SSCs) are capable of transmitting genetic information to the next generations and they are the initial cells for spermatogenesis. Nevertheless, it remains largely unknown about key genes and signaling pathways that regulate fate determinations of human SSCs and male infertility. In this study, we explored the expression, function, and mechanism of USP11 in controlling the proliferation and apoptosis of human SSCs as well as the association between its abnormality and azoospermia. We found that USP11 was predominantly expressed in human SSCs as shown by database analysis and immunohistochemistry. USP11 silencing led to decreases in proliferation and DNA synthesis and an enhancement in apoptosis of human SSCs. RNA-sequencing identified HOXC5 as a target of USP11 in human SSCs. Double immunofluorescence, Co-immunoprecipitation (Co-IP), and molecular docking demonstrated an interaction between USP11 and HOXC5 in human SSCs. HOXC5 knockdown suppressed the growth of human SSCs and increased apoptosis via the classical WNT/ß-catenin pathway. In contrast, HOXC5 overexpression reversed the effect of proliferation and apoptosis induced by USP11 silencing. Significantly, lower levels of USP11 expression were observed in the testicular tissues of patients with spermatogenic disorders. Collectively, these results implicate that USP11 regulates the fate decisions of human SSCs through the HOXC5/WNT/ß-catenin pathway. This study thus provides novel insights into understanding molecular mechanisms underlying human spermatogenesis and the etiology of azoospermia and it offers new targets for gene therapy of male infertility.

[Frequency and characteristics of Y chromosome microdeletions and karyotypic abnormalities among 4 278 infertile male patients from southwest China].

OBJECTIVE: To determine the frequency and characteristics of AZF microdeletions of Y chromosome and karyotypic abnormalities among infertile male patients from southwest China. METHODS: 4 278 infertile male patients treated at West China Second University Hospital of Sichuan University from September 2018 to July 2023 were selected as the study subjects. Results of Y chromosome microdeletion detection and G-banded karyotyping analysis were retrospectively reviewed. RESULTS: Clinical data of the patients were collected, which have included 2 048 patients with azoospermia, 1 536 patients with oligozoospermia, 310 patients with mild to moderate oligozoospermia, and 384 patients with infertility but normal sperm concentration. An abnormal karyotype was found in 213 (8.80%) of 2 421 patients who had undergone karyotyping analysis. The frequency of Y chromosome microdeletions was 9.86% (422/4 278), which had occurred in 10.4%, 13.28%, 0.97% and 0.52% of the cases with azoospermia, severe oligozoospermia, mild to moderate oligozoospermia, and infertility with normal sperm concentration, respectively. CONCLUSION: Y chromosome microdeletion detection and karyotyping analysis are crucial for assessing the cause of male infertility. Early diagnosis can facilitate the selection of reproductive methods.

Toward clinical exomes in diagnostics and management of male infertility.

Infertility, affecting ∼10% of men, is predominantly caused by primary spermatogenic failure (SPGF). We screened likely pathogenic and pathogenic (LP/P) variants in 638 candidate genes for male infertility in 521 individuals presenting idiopathic SPGF and 323 normozoospermic men in the ESTAND cohort. Molecular diagnosis was reached for 64 men with SPGF (12%), with findings in 39 genes (6%). The yield did not differ significantly between the subgroups with azoospermia (20/185, 11%), oligozoospermia (18/181, 10%), and primary cryptorchidism with SPGF (26/155, 17%). Notably, 19 of 64 LP/P variants (30%) identified in 28 subjects represented recurrent findings in this study and/or with other male infertility cohorts. NR5A1 was the most frequently affected gene, with seven LP/P variants in six SPGF-affected men and two normozoospermic men. The link to SPGF was validated for recently proposed candidate genes ACTRT1, ASZ1, GLUD2, GREB1L, LEO1, RBM5, ROS1, and TGIF2LY. Heterozygous truncating variants in BNC1, reported in female infertility, emerged as plausible causes of severe oligozoospermia. Data suggested that several infertile men may present congenital conditions with less pronounced or pleiotropic phenotypes affecting the development and function of the reproductive system. Genes regulating the hypothalamic-pituitary-gonadal axis were affected in >30% of subjects with LP/P variants. Six individuals had more than one LP/P variant, including five with two findings from the gene panel. A 4-fold increased prevalence of cancer was observed in men with genetic infertility compared to the general male population (8% vs. 2%; p = 4.4 × 10-3). Expanding genetic testing in andrology will contribute to the multidisciplinary management of SPGF.

Sox9 downregulation in non-obstructive azoospermia by UTF1 and mediator role of POU5F1.

BACKGROUND: Spermatogenesis is the process of producing mature sperm from Spermatogonial stem cells (SSCs) and this process requires a complex cooperation of different types of somatic and germ cells. Undifferentiated spermatogonia initiate the spermatogenesis and Sertoli cells as the only somatic cells inside of the seminiferous tubule play a key role in providing chemical and physical requirements for normal spermatogenesis, here, we investigated the dysfunction of these cells in non-obstructive azoospermia. MATERIAL AND METHOD: In this study, we analyzed the expression of sox9 and UTF1 in the non-obstructive human testis by immunohistochemistry. Moreover, we used the KEGG pathway and bioinformatics analysis to reveal the connection between our object genes and protein. RESULTS: The immunohistochemistry analysis of the non-obstructive human seminiferous tubule showed low expression of Sox9 and UTF1 that was detected out of the main location of the responsible cells for these expressions. Our bioinformatics analysis clearly and strongly indicated the relation between UTF1 in undifferentiated spermatogonia and Sox9 in Sertoli cells mediated by POU5F1. CONCLUSION: Generally, this study showed the negative effect of POU5F1 as a mediator between Sertoli cells as the somatic cells within seminiferous tubules and undifferentiated spermatogonia as the spermatogenesis initiator germ cells in non-obstructive conditions.

Systematic molecular analyses for 115 karyotypically normal men with isolated non-obstructive azoospermia.

STUDY QUESTION: Do copy-number variations (CNVs) in the azoospermia factor (AZF) regions and monogenic mutations play a major role in the development of isolated (non-syndromic) non-obstructive azoospermia (NOA) in Japanese men with a normal 46, XY karyotype? SUMMARY ANSWER: Deleterious CNVs in the AZF regions and damaging sequence variants in eight genes likely constitute at least 8% and approximately 8% of the genetic causes, respectively, while variants in other genes play only a minor role. WHAT IS KNOWN ALREADY: Sex chromosomal abnormalities, AZF-linked microdeletions, and monogenic mutations have been implicated in isolated NOA. More than 160 genes have been reported as causative/susceptibility/candidate genes for NOA. STUDY DESIGN, SIZE, DURATION: Systematic molecular analyses were conducted for 115 patients with isolated NOA and a normal 46, XY karyotype, who visited our hospital between 2017 and 2021. PARTICIPANTS/MATERIALS, SETTING, METHODS: We studied 115 unrelated Japanese patients. AZF-linked CNVs were examined using sequence-tagged PCR and multiplex ligation-dependent probe amplification, and nucleotide variants were screened using whole exome sequencing (WES). An optimized sequence kernel association test (SKAT-O), a gene-based association study using WES data, was performed to identify novel disease-associated genes in the genome. The results were compared to those of previous studies and our in-house control data. MAIN RESULTS AND THE ROLE OF CHANCE: Thirteen types of AZF-linked CNVs, including the hitherto unreported gr/gr triplication and partial AZFb deletion, were identified in 63 (54.8%) cases. When the gr/gr deletion, a common polymorphism in Japan, was excluded from data analyses, the total frequency of CNVs was 23/75 (30.7%). This frequency is higher than that of the reference data in Japan and China (11.1% and 14.7%, respectively). Known NOA-causative AZF-linked CNVs were found in nine (7.8%) cases. Rare damaging variants in known causative genes (DMRT1, PLK4, SYCP2, TEX11, and USP26) and hemizygous/multiple-heterozygous damaging variants in known spermatogenesis-associated genes (TAF7L, DNAH2, and DNAH17) were identified in nine cases (7.8% in total). Some patients carried rare damaging variants in multiple genes. SKAT-O detected no genes whose rare damaging variants were significantly accumulated in the patient group. LIMITATIONS, REASONS FOR CAUTION: The number of participants was relatively small, and the clinical information of each patient was fragmentary. Moreover, the pathogenicity of identified variants was assessed only by in silico analyses. WIDER IMPLICATIONS OF THE FINDINGS: This study showed that various AZF-linked CNVs are present in more than half of Japanese NOA patients. These results broadened the structural variations of AZF-linked CNVs, which should be considered for the molecular diagnosis of spermatogenic failure. Furthermore, the results of this study highlight the etiological heterogeneity and possible oligogenicity of isolated NOA. STUDY FUNDING/COMPETING INTEREST(S): This study was supported by Grants from the Japan Society for the Promotion of Science (21K19283 and 21H0246), the Japan Agency for Medical Research and Development (22ek0109464h0003), the National Center for Child Health and Development, the Canon Foundation, the Japan Endocrine Society, and the Takeda Science Foundation. The results of this study were based on samples and patient data obtained from the International Center for Reproductive Medicine, Dokkyo Medical University Saitama Medical Center, Koshigaya, Japan. The authors have no conflicts of interest to disclose. TRIAL REGISTRATION NUMBER: N/A.

Genetic profiling of azoospermic men to identify the etiology and predict reproductive potential.

PURPOSE: To identify germline mutations related to azoospermia etiology and reproductive potential of surgically retrieved spermatozoa, and to investigate the feasibility of predicting seminiferous tubule function of nonobstructive azoospermic men by transcriptomic profiling of ejaculates. MATERIALS AND METHODS: Sperm specimens were obtained from 30 men (38.4 ± 6 years) undergoing epididymal sperm aspiration for obstructive azoospermia (OA, n = 19) acquired by vasectomy, or testicular biopsy for nonobstructive azoospermia (NOA, n = 11). To evaluate for a correlation with azoospermia etiology, DNAseq was performed on surgically retrieved spermatozoa, and cell-free RNAseq on seminal fluid (n = 23) was performed to predict spermatogenesis in the seminiferous tubule. RESULTS: Overall, surgically retrieved sperm aneuploidy rates were 1.7% and 1.8% among OA and NOA cohorts, respectively. OA men carried housekeeping-related gene mutations, while NOA men displayed mutations on genes involved in crucial spermiogenic functions (AP1S2, AP1G2, APOE). We categorized couples within each cohort according to ICSI clinical outcomes to investigate genetic causes that may affect reproductive potential. All OA-fertile men (n = 9) carried mutations in ZNF749 (sperm production), whereas OA-infertile men (n = 10) harbored mutations in PRB1, which is essential for DNA replication. NOA-fertile men (n = 8) carried mutations in MPIG6B (stem cell lineage differentiation), whereas NOA-infertile individuals (n = 3) harbored mutations in genes involved in spermato/spermio-genesis (ADAM29, SPATA31E1, MAK, POLG, IFT43, ATG9B) and early embryonic development (MBD5, CCAR1, PMEPA1, POLK, REC8, REPIN1, MAPRE3, ARL4C). Transcriptomic assessment of cell-free RNAs in seminal fluid from NOA men allowed the prediction of residual spermatogenic foci. CONCLUSIONS: Sperm genome profiling provides invaluable information on azoospermia etiology and identifies gene-related mechanistic links to reproductive performance. Moreover, RNAseq assessment of seminal fluid from NOA men can help predict sperm retrieval during testicular biopsies.

Describing patterns of familial cancer risk in subfertile men using population pedigree data.

STUDY QUESTION: Can we simultaneously assess risk for multiple cancers to identify familial multicancer patterns in families of azoospermic and severely oligozoospermic men? SUMMARY ANSWER: Distinct familial cancer patterns were observed in the azoospermia and severe oligozoospermia cohorts, suggesting heterogeneity in familial cancer risk by both type of subfertility and within subfertility type. WHAT IS KNOWN ALREADY: Subfertile men and their relatives show increased risk for certain cancers including testicular, thyroid, and pediatric. STUDY DESIGN, SIZE, DURATION: A retrospective cohort of subfertile men (N = 786) was identified and matched to fertile population controls (N = 5674). Family members out to third-degree relatives were identified for both subfertile men and fertile population controls (N = 337 754). The study period was 1966-2017. Individuals were censored at death or loss to follow-up, loss to follow-up occurred if they left Utah during the study period. PARTICIPANTS/MATERIALS, SETTING, METHODS: Azoospermic (0 × 106/mL) and severely oligozoospermic (<1.5 × 106/mL) men were identified in the Subfertility Health and Assisted Reproduction and the Environment cohort (SHARE). Subfertile men were age- and sex-matched 5:1 to fertile population controls and family members out to third-degree relatives were identified using the Utah Population Database (UPDB). Cancer diagnoses were identified through the Utah Cancer Registry. Families containing ≥10 members with ≥1 year of follow-up 1966-2017 were included (azoospermic: N = 426 families, 21 361 individuals; oligozoospermic: N = 360 families, 18 818 individuals). Unsupervised clustering based on standardized incidence ratios for 34 cancer phenotypes in the families was used to identify familial multicancer patterns; azoospermia and severe oligospermia families were assessed separately. MAIN RESULTS AND THE ROLE OF CHANCE: Compared to control families, significant increases in cancer risks were observed in the azoospermia cohort for five cancer types: bone and joint cancers hazard ratio (HR) = 2.56 (95% CI = 1.48-4.42), soft tissue cancers HR = 1.56 (95% CI = 1.01-2.39), uterine cancers HR = 1.27 (95% CI = 1.03-1.56), Hodgkin lymphomas HR = 1.60 (95% CI = 1.07-2.39), and thyroid cancer HR = 1.54 (95% CI = 1.21-1.97). Among severe oligozoospermia families, increased risk was seen for three cancer types: colon cancer HR = 1.16 (95% CI = 1.01-1.32), bone and joint cancers HR = 2.43 (95% CI = 1.30-4.54), and testis cancer HR = 2.34 (95% CI = 1.60-3.42) along with a significant decrease in esophageal cancer risk HR = 0.39 (95% CI = 0.16-0.97). Thirteen clusters of familial multicancer patterns were identified in families of azoospermic men, 66% of families in the azoospermia cohort showed population-level cancer risks, however, the remaining 12 clusters showed elevated risk for 2-7 cancer types. Several of the clusters with elevated cancer risks also showed increased odds of cancer diagnoses at young ages with six clusters showing increased odds of adolescent and young adult (AYA) diagnosis [odds ratio (OR) = 1.96-2.88] and two clusters showing increased odds of pediatric cancer diagnosis (OR = 3.64-12.63). Within the severe oligozoospermia cohort, 12 distinct familial multicancer clusters were identified. All 12 clusters showed elevated risk for 1-3 cancer types. An increase in odds of cancer diagnoses at young ages was also seen in five of the severe oligozoospermia familial multicancer clusters, three clusters showed increased odds of AYA diagnosis (OR = 2.19-2.78) with an additional two clusters showing increased odds of a pediatric diagnosis (OR = 3.84-9.32). LIMITATIONS, REASONS FOR CAUTION: Although this study has many strengths, including population data for family structure, cancer diagnoses and subfertility, there are limitations. First, semen measures are not available for the sample of fertile men. Second, there is no information on medical comorbidities or lifestyle risk factors such as smoking status, BMI, or environmental exposures. Third, all of the subfertile men included in this study were seen at a fertility clinic for evaluation. These men were therefore a subset of the overall population experiencing fertility problems and likely represent those with the socioeconomic means for evaluation by a physician. WIDER IMPLICATIONS OF THE FINDINGS: This analysis leveraged unique population-level data resources, SHARE and the UPDB, to describe novel multicancer clusters among the families of azoospermic and severely oligozoospermic men. Distinct overall multicancer risk and familial multicancer patterns were observed in the azoospermia and severe oligozoospermia cohorts, suggesting heterogeneity in cancer risk by type of subfertility and within subfertility type. Describing families with similar cancer risk patterns provides a new avenue to increase homogeneity for focused gene discovery and environmental risk factor studies. Such discoveries will lead to more accurate risk predictions and improved counseling for patients and their families. STUDY FUNDING/COMPETING INTEREST(S): This work was funded by GEMS: Genomic approach to connecting Elevated germline Mutation rates with male infertility and Somatic health (Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD): R01 HD106112). The authors have no conflicts of interest relevant to this work. TRIAL REGISTRATION NUMBER: N/A.

[Not unusual case of male genetic infertility]. / Infertilité masculine d'origine génétique : un cas pas si inhabituel.

Following a year of regular unprotected intercourse with his partner, and without achieving pregnancy, Mr. L. turned to his general practitioner. A semen analysis was carried out and no spermatozoa was found. After being referred to a male infertility specialist, the patient underwent a second test and a comprehensive assessment of his azoospermia. The azoospermia was confirmed and the genetic investigation revealed aneuploidy..

Changes in environmental exposures over decades may influence the genetic architecture of severe spermatogenic failure.

STUDY QUESTION: Do the genetic determinants of idiopathic severe spermatogenic failure (SPGF) differ between generations? SUMMARY ANSWER: Our data support that the genetic component of idiopathic SPGF is impacted by dynamic changes in environmental exposures over decades. WHAT IS KNOWN ALREADY: The idiopathic form of SPGF has a multifactorial etiology wherein an interaction between genetic, epigenetic, and environmental factors leads to the disease onset and progression. At the genetic level, genome-wide association studies (GWASs) allow the analysis of millions of genetic variants across the genome in a hypothesis-free manner, as a valuable tool for identifying susceptibility risk loci. However, little is known about the specific role of non-genetic factors and their influence on the genetic determinants in this type of conditions. STUDY DESIGN, SIZE, DURATION: Case-control genetic association analyses were performed including a total of 912 SPGF cases and 1360 unaffected controls. PARTICIPANTS/MATERIALS, SETTING, METHODS: All participants had European ancestry (Iberian and German). SPGF cases were diagnosed during the last decade either with idiopathic non-obstructive azoospermia (n = 547) or with idiopathic non-obstructive oligozoospermia (n = 365). Case-control genetic association analyses were performed by logistic regression models considering the generation as a covariate and by in silico functional characterization of the susceptibility genomic regions. MAIN RESULTS AND THE ROLE OF CHANCE: This analysis revealed 13 novel genetic association signals with SPGF, with eight of them being independent. The observed associations were mostly explained by the interaction between each lead variant and the age-group. Additionally, we established links between these loci and diverse non-genetic factors, such as toxic or dietary habits, respiratory disorders, and autoimmune diseases, which might potentially influence the genetic architecture of idiopathic SPGF. LARGE SCALE DATA: GWAS data are available from the authors upon reasonable request. LIMITATIONS, REASONS FOR CAUTION: Additional independent studies involving large cohorts in ethnically diverse populations are warranted to confirm our findings. WIDER IMPLICATIONS OF THE FINDINGS: Overall, this study proposes an innovative strategy to achieve a more precise understanding of conditions such as SPGF by considering the interactions between a variable exposome through different generations and genetic predisposition to complex diseases. STUDY FUNDING/COMPETING INTEREST(S): This work was supported by the "Plan Andaluz de Investigación, Desarrollo e Innovación (PAIDI 2020)" (ref. PY20_00212, P20_00583), the Spanish Ministry of Economy and Competitiveness through the Spanish National Plan for Scientific and Technical Research and Innovation (ref. PID2020-120157RB-I00 funded by MCIN/ AEI/10.13039/501100011033), and the 'Proyectos I+D+i del Programa Operativo FEDER 2020' (ref. B-CTS-584-UGR20). ToxOmics-Centre for Toxicogenomics and Human Health, Genetics, Oncology and Human Toxicology, is also partially supported by the Portuguese Foundation for Science and Technology (Projects: UIDB/00009/2020; UIDP/00009/2020). The authors declare no competing interests. TRIAL REGISTRATION NUMBER: N/A.

RNA m6A modification regulates L1 retrotransposons in human spermatogonial stem cell differentiation in vitro and in vivo.

The maintenance of genome integrity in the germline is crucial for mammalian development. Long interspersed element type 1 (LINE-1, L1) is a mobile genetic element that makes up about 17% of the human genome and poses a threat to genome integrity. N6-methyl-adenosine (m6A) plays an essential role in regulating various biological processes. However, the function of m6A modification in L1 retrotransposons and human germline development remains largely unknown. Here we knocked out the m6A methyltransferase METTL3 or the m6A reader YTHDF2 in human embryonic stem cells (hESCs) and discovered that METTL3 and YTHDF2 are crucial for inducing human spermatogonial stem cells (hSSCs) from hESCs in vitro. The removal of METTL3 or YTHDF2 resulted in increased L1 retrotransposition and reduced the efficiency of SSC differentiation in vitro. Further analysis showed that YTHDF2 recognizes the METTL3-catalyzed m6A modification of L1 retrotransposons and degrades L1 mRNA through autophagy, thereby blocking L1 retrotransposition. Moreover, the study confirmed that m6A modification in human fetal germ cells promotes the degradation of L1 retrotransposon RNA, preventing the insertion of new L1 retrotransposons into the genome. Interestingly, L1 retrotransposon RNA was highly expressed while METTL3 was significantly downregulated in the seminal plasma of azoospermic patients with meiotic arrest compared to males with normal fertility. Additionally, we identified some potentially pathogenic variants in m6A-related genes in azoospermic men with meiotic arrest. In summary, our study suggests that m6A modification serves as a guardian of genome stability during human germline development and provides novel insights into the function and regulatory mechanisms of m6A modification in restricting L1 retrotransposition.

Y chromosome polymorphisms contribute to an increased risk of non-obstructive azoospermia: a retrospective study of 32,055 Chinese men.

PURPOSE: To investigate the prevalence of Y chromosome polymorphisms in Chinese men and analyze their associations with male infertility and female adverse pregnancy outcomes. METHODS: The clinical data of 32,055 Chinese men who underwent karyotype analysis from October 2014 to September 2019 were collected. Fisher's exact test, chi-square test, or Kruskal-Wallis test was used to analyze the effects of Y chromosome polymorphism on semen parameters, azoospermia factor (AZF) microdeletions, and female adverse pregnancy outcomes. RESULTS: The incidence of Y chromosome polymorphic variants was 1.19% (381/32,055) in Chinese men. The incidence of non-obstructive azoospermia (NOA) was significantly higher in men with the Yqh- variant than that in men with normal karyotype and other Y chromosome polymorphic variants (p < 0.050). The incidence of AZF microdeletions was significantly different among the normal karyotype and different Y chromosome polymorphic variant groups (p < 0.001). The detection rate of AZF microdeletions was 28.92% (24/83) in the Yqh- group and 2.50% (3/120) in the Y ≤ 21 group. The AZFb + c region was the most common AZF microdeletion (78.57%, 22/28), followed by AZFc microdeletion (7.14%,2/28) in NOA patients with Yqh- variants. There was no significant difference in the distribution of female adverse pregnancy outcomes among the normal karyotype and different Y chromosome polymorphic variant groups (p = 0.528). CONCLUSIONS: Patients with 46,XYqh- variant have a higher incidence of NOA and AZF microdeletions than patients with normal karyotype and other Y chromosome polymorphic variants. Y chromosome polymorphic variants do not affect female adverse pregnancy outcomes.

A report of two homozygous TERB1 protein-truncating variants in two unrelated women with primary infertility.

PURPOSE: To investigate the genetic etiology of patients with female infertility. METHODS: Whole Exome Sequencing was performed on genomic DNA extracted from the patient's blood. Exome data were filtered for damaging rare biallelic variants in genes with possible roles in reproduction. Sanger sequencing was used to validate the selected variants and segregate them in family members. RESULTS: A novel homozygous likely pathogenic variant, c.626G>A, p.Trp209*, was identified in the TERB1 gene of the patient. Additionally, we report a second homozygous pathogenic TERB1 variant, c.1703C>G, p.Ser568*, in an infertile woman whose azoospermic brother was previously described to be homozygous for her variant. CONCLUSIONS: Here, we report for the first time two homozygous likely pathogenic and pathogenic TERB1 variants, c.626G>A, p.Trp209* and c.1703C>G, p.Ser568*, respectively, in two unrelated women with primary infertility. TERB1 is known to play an essential role in homologous chromosome movement, synapsis, and recombination during the meiotic prophase I and has an established role in male infertility in humans. Our data add TERB1 to the shortlist of Meiosis I genes associated with human infertility in both sexes.

A novel homozygote nonsense variant of MSH4 leads to primary ovarian insufficiency and non-obstructive azoospermia.

BACKGROUND: Both non-obstructive azoospermia (NOA) and primary ovarian insufficiency (POI) are pathological conditions characterized by premature and frequently complete gametogenesis failure. Considering that the conserved meiosis I steps are the same between oogenesis and spermatogenesis, inherited defects in meiosis I may result in common causes for both POI and NOA. The present research is a retrospective investigation on an Iranian family with four siblings of both genders who were affected by primary gonadal failure. METHODS: Proband, an individual with NOA, was subjected to clinical examination, hormonal assessment, and genetic consultation. After reviewing the medical history of other infertile members of the family, patients with NOA went through genetic investigations including karyotyping and assessment of Y chromosome microdeletions, followed by Whole exome sequencing (WES) on the proband. After analyzing WES data, the candidate variant was validated using Sanger sequencing and traced in the family. RESULTS: WES analysis of the proband uncovered a novel homozygote nonsense variant, namely c.118C>T in MSH4. This variant resulted in the occurrence of a premature stop codon in residue 40 of MSH4. Notably, the variant was absent in all public exome databases and in the exome data of 400 fertile Iranian individuals. Additionally, the variant was found to co-segregate with infertility in the family. It was also observed that all affected members had homozygous mutations, while their parents were heterozygous and the fertile sister had no mutant allele, corresponding to autosomal recessive inheritance. In addition, we conducted a review of variants reported so far in MSH4, as well as available clinical features related to these variants. The results show that the testicular sperm retrieval and ovarian stimulation cycles have not been successful yet. CONCLUSION: Overall, the results of this study indicate that the identification of pathogenic variants in this gene will be beneficial in selecting proper therapeutic strategies. Also, the findings of this study demonstrate that clinicians should obtain the history of other family members of the opposite sex when diagnosing for POI and/or NOA.

An analysis of Y-chromosome microdeletion in infertile Korean men with severe oligozoospermia or azoospermia.

PURPOSE: Infertility affects 10% to 15% of couples, and male factor accounts for 50% of the cases. The relevant male genetic factors, which account for at least 15% of male infertility, include Y-chromosome microdeletions. We investigated clinical data and patterns of Y-chromosome microdeletions in Korean infertile men. MATERIALS AND METHODS: A total of 919 infertile men whose sperm concentration was ≤5 million/mL in two consecutive analyses were investigated for Y-chromosome microdeletion. Among them, 130 infertile men (14.1%) demonstrated Y-chromosome microdeletions. Medical records were retrospectively reviewed. RESULTS: In 130 men with Y-chromosome microdeletions, 90 (69.2%) had azoospermia and 40 (30.8%) had severe oligozoospermia. The most frequent microdeletions were in the azoospermia factor (AZF) c region (77/130, 59.2%), followed by the AZFb+c (30/130, 23.1%), AZFa (8/130, 6.2%), AZFb (7/130, 5.4%), AZFa+b+c (7/130, 5.4%), and AZFa+c (1/130, 0.7%) regions. In men with oligozoospermia, 37 (92.5%) had AZFc microdeletion. Chromosomal abnormalities were detected in 30 patients (23.1%). Higher follicle-stimulating hormone level (23.2±13.5 IU/L vs. 15.1±9.0 IU/L, p<0.001), higher luteinizing hormone level (9.7±4.6 IU/L vs. 6.0±2.2 IU/L, p<0.001), and lower testis volume (10.6±4.8 mL vs. 13.3±3.8 mL, p<0.001) were observed in azoospermia patients compared to severe oligozoospermia patients. CONCLUSIONS: Y-chromosome microdeletion is a common genetic cause of male infertility. Therefore, Y-chromosome microdeletion test is recommended for the accurate diagnosis of men with azoospermia or severe oligozoospermia. Appropriate genetic counseling is mandatory before the use of assisted reproduction technique in men with Y-chromosome microdeletion.

Deleterious variants in X-linked RHOXF1 cause male infertility with oligo- and azoospermia.

Oligozoospermia and azoospermia are two common phenotypes of male infertility characterized by massive sperm defects owing to failure of spermatogenesis. The deleterious impact of candidate variants with male infertility is to be explored. In our study, we identified three hemizygous missense variants (c.388G>A: p.V130M, c.272C>T: p.A91V, and c.467C>T: p.A156V) and one hemizygous nonsense variant (c.478C>T: p.R160X) in the Rhox homeobox family member 1 gene (RHOXF1) in four unrelated cases from a cohort of 1201 infertile Chinese men with oligo- and azoospermia using whole-exome sequencing and Sanger sequencing. RHOXF1 was absent in the testicular biopsy of one patient (c.388G>A: p.V130M) whose histological analysis showed a phenotype of Sertoli cell-only syndrome. In vitro experiments indicated that RHOXF1 mutations significantly reduced the content of RHOXF1 protein in HEK293T cells. Specifically, the p.V130M, p.A156V, and p.R160X mutants of RHOXF1 also led to increased RHOXF1 accumulation in cytoplasmic particles. Luciferase assays revealed that p.V130M and p.R160X mutants may disrupt downstream spermatogenesis by perturbing the regulation of doublesex and mab-3 related transcription factor 1 (DMRT1) promoter activity. Furthermore, ICSI treatment could be beneficial in the context of oligozoospermia caused by RHOXF1 mutations. In conclusion, our findings collectively identified mutated RHOXF1 to be a disease-causing X-linked gene in human oligo- and azoospermia.

A novel SNP in HUWE1 promoter confers increased risk of NOA by affecting the RA/RARα pathway in Chinese individuals.

BACKGROUND: The ubiquitin ligase HECT, UBA, and WWE domain-containing E3 ubiquitin protein ligase 1 is essential for the establishment and maintenance of spermatogonia. However, the role of HECT, UBA, and WWE domain-containing E3 ubiquitin protein ligase 1 in regulating germ cell differentiation remains unclear, and clinical evidence linking HECT, UBA, and WWE domain-containing E3 ubiquitin protein ligase 1 to male infertility pathogenesis is lacking. OBJECTIVE: This study aims to investigate the role of HUWE1 in germ cell differentiation and the mechanism by which a HUWE1 single nucleotide polymorphism increases male infertility risk. MATERIALS AND METHODS: We analyzed HUWE1 single nucleotide polymorphisms in 190 non-obstructive azoospermia patients of Han Chinese descent. We evaluated HECT, UBA, and WWE domain-containing E3 ubiquitin protein ligase 1 regulation by retinoic acid receptor alpha using chromatin immunoprecipitation assays, electrophoretic mobility shift assays, and siRNA-mediated RARα knockdown. Using C18-4 spermatogonial cells, we determined whether HECT, UBA, and WWE domain-containing E3 ubiquitin protein ligase 1 participated in retinoic acid-mediated retinoic acid receptor alpha signaling. We performed luciferase assays, cell counting kit-8 assays, immunofluorescence, quantitative real-time polymerase chain reaction, and western blotting. We quantified HUWE1 and retinoic acid receptor alpha in testicular biopsies from non-obstructive azoospermia and obstructive azoospermia patients using quantitative real-time polymerase chain reaction and immunofluorescence. RESULTS: Three HUWE1 single nucleotide polymorphisms were significantly associated with spermatogenic failure in 190 non-obstructive azoospermia patients; one (rs34492591) was in the HUWE1 promoter. Retinoic acid receptor alpha regulates HUWE1 gene expression by binding to its promoter. HECT, UBA, and WWE domain-containing E3 ubiquitin protein ligase 1 participates in retinoic acid/retinoic acid receptor alpha signaling pathway and regulates the expression of germ cell differentiation genes STRA8 and SCP3 to inhibit cell proliferation and reduce γH2AX accumulation. Notably, significantly lower levels of HUWE1 and RARα were detected in testicular biopsy samples from non-obstructive azoospermia patients. CONCLUSIONS: An HUWE1 promoter single nucleotide polymorphism significantly downregulates its expression in non-obstructive azoospermia patients. Mechanistically, HECT, UBA, and WWE domain-containing E3 ubiquitin protein ligase 1 regulates germ cell differentiation during meiotic prophase through its participation in retinoic acid/retinoic acid receptor alpha signaling and subsequent modulation of γH2AX. Taken together, these results strongly suggest that the genetic polymorphisms of HUWE1 are closely related to spermatogenesis and non-obstructive azoospermia pathogenesis.

Seminal extracellular vesicle sncRNA sequencing reveals altered miRNA/isomiR profiles as sperm retrieval biomarkers for azoospermia.

BACKGROUND: Non-invasive molecular biomarkers for classifying azoospermia by origin into either obstructive or non-obstructive/secretory azoospermia, as well as for inferring the spermatogenic reserve of the testis of non-obstructive/secretory azoospermia patients, are of great interest for testicular sperm retrieval outcome prediction for assisted reproduction. Prior analyses of semen small non-coding RNA expression in azoospermia have focused on microRNAs, but there has been a lack of attention on other regulatory small RNA species. In this regard, studying more in-depth expression changes of small non-coding RNA subtypes in small extracellular vesicles from semen of azoospermic individuals could be useful to select additional non-invasive biomarkers with diagnostic/prognostic purposes. MATERIAL AND METHODS: A high-throughput small RNA profiling analysis to determine the expression pattern of seminal small extracellular vesicle microRNAs (analyzed at the isomiR level), PIWI-interacting RNAs, and transfer RNA-derived small RNAs in normozoospermic (n = 4) and azoospermic (obstructive azoospermia because of pathological occurring obstruction in the genital tract, n = 4; secretory azoospermic individuals with positive testicular sperm extraction value, n = 5; secretory azoospermic individuals with negative testicular sperm extraction value, n = 4) individuals was carried out. Reverse transcriptase-quantitative real-time polymerase chain reaction validation analysis of selected microRNAs was additionally performed in a larger number of individuals. RESULTS AND DISCUSSION: Clinically relevant quantitative changes in the small non-coding RNA levels contained in semen small extracellular vesicles can be used as biomarkers for the origin of azoospermia and for predicting the presence of residual spermatogenesis. In this regard, canonical isoform microRNAs (n = 185) but also other isomiR variants (n = 238) stand out in terms of numbers and fold-change differences in expression, underlining the need to consider isomiRs when investigating microRNA-based regulation. Conversely, although transfer RNA-derived small RNAs are shown in our study to represent a high proportion of small non-coding RNA sequences in seminal small extracellular vesicle samples, they are not able to discriminate the origin of azoospermia. PIWI-interacting RNA cluster profiles and individual PIWI-interacting RNAs with significant differential expression were also not able to discriminate. Our study demonstrated that expression values of individual and/or combined canonical isoform microRNAs (miR-10a-5p, miR-146a-5p, miR-31-5p, miR-181b-5p; area under the receiver operating characteristic curve >0.8) in small extracellular vesicles provide considerable clinical value in identifying samples with a high likelihood of sperm retrieval while discriminating azoospermia by origin. Although no individual microRNA showed sufficient discriminating power on its own to identify severe spermatogenic disorders with focal spermatogenesis, multivariate microRNA models in semen small extracellular vesicles have the potential to identify those individuals with residual spermatogenesis. Availability and adoption of such non-invasive molecular biomarkers would represent a great improvement in reproductive treatment decision protocols for azoospermia in clinical practice.

EAA/EMQN best practice guidelines for molecular diagnosis of Y-chromosomal microdeletions: State of the art 2023.

Testing for AZoospermia Factor (AZF) deletions of the Y chromosome is a key component of the diagnostic workup of azoospermic and severely oligozoospermic men. This revision of the 2013 European Academy of Andrology (EAA) and EMQN CIC (previously known as the European Molecular Genetics Quality Network) laboratory guidelines summarizes recent clinically relevant advances and provides an update on the results of the external quality assessment program jointly offered by both organizations. A basic multiplex PCR reaction followed by a deletion extension analysis remains the gold-standard methodology to detect and correctly interpret AZF deletions. Recent data have led to an update of the sY84 reverse primer sequence, as well as to a refinement of what were previously considered as interchangeable border markers for AZFa and AZFb deletion breakpoints. More specifically, sY83 and sY143 are no longer recommended for the deletion extension analysis, leaving sY1064 and sY1192, respectively, as first-choice markers. Despite the transition, currently underway in several countries, toward a diagnosis based on certified kits, it should be noted that many of these commercial products are not recommended due to an unnecessarily high number of tested markers, and none of those currently available are, to the best of our knowledge, in accordance with the new first-choice markers for the deletion extension analysis. The gr/gr partial AZFc deletion remains a population-specific risk factor for impaired sperm production and a predisposing factor for testicular germ cell tumors. Testing for this deletion type is, as before, left at the discretion of the diagnostic labs and referring clinicians. Annual participation in an external quality control program is strongly encouraged, as the 22-year experience of the EMQN/EAA scheme clearly demonstrates a steep decline in diagnostic errors and an improvement in reporting practice.

Whole-Exome Sequencing Analysis of Idiopathic Hypogonadotropic Hypogonadism: Comparison of Varicocele and Nonobstructive Azoospermia.

As a rare disease leading to male infertility, idiopathic hypogonadotropic hypogonadism (IHH) has strong heterogeneity of clinical phenotype and gene mutation. At present, there is no effective diagnosis and treatment method for this disease. This study is to explore the possible new pathogenic gene of idiopathic hypogonadotrophic hypogonadism and the pathological mechanism affecting its occurrence. We performed a whole-exome sequencing on 9 patients with normosmic idiopathic hypogonadotropic hypogonadism (nIHH), 19 varicocele patients with asthenospermia, oligospermia, or azoospermia, 5 patients with simple nonobstructive azoospermia, and 13 normal healthy adult males and carried out comparative analysis, channel analysis, etc. After preliminary sequencing screening, 309-431 genes harbouring variants, including SNPs and indels, were predicted to be harmful per single patient in each group. In genetic variations of nIHH patients' analysis, variants were detected in 10 loci and nine genes in nine patients. And in co-analysis of the three patient groups, nine nIHH patients, 19 VC patients, and five SN patients shared 116 variants, with 28 variant-harbouring genes detected in five or more patients. We found that the NEFH, CCDC177, and PCLO genes and the Gene Ontology pathways GO:0051301: cell division and GO:0090066: regulation of anatomical structure size may be key factors in the pathogenic mechanism of IHH. Our results suggest that the pathogenic mechanism of IHH is not limited to the central nervous system effects of GnRH but may involve other heterogeneous pathogenic genetic variants that affect peripheral organs.