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.

A bi-allelic REC114 loss-of-function variant causes meiotic arrest and nonobstructive azoospermia

Nonobstructive azoospermia (NOA), the most severe manifestation of male infertility, lacks a comprehensive understanding of its genetic etiology. Here, a bi-allelic loss-of-function variant in REC114 (c.568C > T: p.Gln190*) were identified through whole exome sequencing (WES) in a Chinese NOA patient. Testicular histopathological analysis and meiotic chromosomal spread analysis were conducted to assess the stage of spermatogenesis arrested. Co-immunoprecipitation (Co-IP) and Western blot (WB) were used to investigate the influence of variant in vitro. In addition, our results revealed that the variant resulted in truncated REC114 protein and impaired interaction with MEI4, which was essential for meiotic DNA double-strand break (DSB) formation. As far as we know, this study presents the first report that identifies REC114 as the causative gene for male infertility. Furthermore, our study demonstrated indispensability of the REC114-MEI4 complex in maintaining DSB homoeostasis, and highlighted that the disruption of the complex due to the REC114 variant may underline the mechanism of NOA.

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.

Scrutinizing the human TEX genes in the context of human male infertility

BACKGROUND

Infertility affects around 15% of all couples worldwide and is increasingly linked to variants in genes specifically expressed in the testis. Well-established causes of male infertility include pathogenic variants in the genes TEX11, TEX14, and TEX15, while few studies have recently reported variants in TEX13B, TEX13C, FAM9A (TEX39A), and FAM9B (TEX39B).

OBJECTIVES

We aimed at screening for novel potential candidate genes among the human TEX ("testis expressed") genes as well as verifying previously described disease associations in this set of genes.

MATERIALS AND METHODS

To this end, we screened the exome sequencing data of 1305 men, including 1056 crypto- and azoospermic individuals, and determined cell-specific expression by analyzing testis-specific single-cell RNA sequencing data for genes with identified variants. To investigate the overarching role in male fertility, we generated testis-specific knockdown (KD) models of all 10 orthologous TEX genes in Drosophila melanogaster.

RESULTS

We detected rare potential disease-causing variants in TEX10, TEX13A, TEX13B, TEX13C, TEX13D, ZFAND3 (TEX27), TEX33, FAM9A (TEX39A), and FAM9B (TEX39B), in 28 infertile men, of which 15 men carried variants in TEX10, TEX27, and TEX33. The KD of TEX2, TEX9, TEX10, TEX13, ZFAND3 (TEX27), TEX28, TEX30, NFX1 (TEX42), TEX261, and UTP4 (TEX292) in Drosophila resulted in normal fertility.

DISCUSSION

Based on our findings, the autosomal dominant predicted genes TEX10 and ZFAND3 (TEX27) and the autosomal recessive predicted gene TEX33, which all three are conceivably required for germ cell maturation, were identified as novel potential candidate genes for human non-obstructive azoospermia. We additionally identified hemizygous loss-of-function (LoF) variants in TEX13B, TEX13C, and FAM9A (TEX39A) as unlikely monogenic culprits of male infertility as LoF variants were also found in control men.

CONCLUSION

Our findings concerning the X-linked genes TEX13B, TEX13C, and FAM9A (TEX39A) contradict previous reports and will decrease false-positive reports in genetic diagnostics of azoospermic men.

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.

Primary azoospermia factor C duplication associated with spermatogenic impariment: a case-control study based on Y-chromosome haplogrouping in a Han Chinese population

BACKGROUND

Azoospermia factor C (AZFc) in the male-specific region of Y-chromosome (MSY) presents wide structure variation mainly due to frequent non-allele homologous recombination, leading to significant copy number variation of the AZFc-linked coding sequences involving in spermatogenesis. A large number of studies had been conducted to investigate the association between AZFc deletions and male infertility in certain Y chromosome genetic backgrounds, however, the influence of primary AZFc duplication on spermatogenesis remained controversial and the cause of the discrepant outcomes is unknown.

METHODS

In the present study, a total of 1,102 unrelated Han Chinese males without any detectable AZF deletions were recruited from 2014 to 2019, including 411 controls with normozoospermia and 691 patients with idiopathic spermatogenic failure. Using multiple paralog ratio tests (PRTs), the structure duplications were classified by the copy number of the AZFc-linked amplicons and genes. The Y-chromosome haplogroup (Y-hg) was categorized by genetyping of MSY-linked polymorphism loci. The association of primary AZFc duplication with spermatogenic phenotype was investigated in males with the same Y-hg.

RESULTS

Within Y-hg O3* group, the frequency of the gr/gr duplication in patients is significantly higher than that of controls (P = 1.29×10-3 , odds ratio (OR) 7.64, 95% confidence interval (CI) 1.79-32.57). Moreover, Y-hg O3* males with the gr/gr duplication presented a significantly lower sperm production compared with non-AZFc duplicated ones (sperm concentration: P = 1.46×10-3 ; total sperm count: P = 1.82 ×10-3 ). The b2/b3 duplication were identified clustered in Y-hg Cα2*, and the significant difference in the distribution was not observed between patients with spermatogenic failure and controls.

CONCLUSION

The results suggest that, in the Han Chinese population, the gr/gr duplication is a predisposing genetic factor for spermatogenic impairment in males harboring Y-hg O3* . Meanwhile, the b2/b3 duplication may be fixed on a yet-unidentified subbranch of Y-hg Cα2* without significantly deleterious effect on spermatogenesis. Our findings provide evidence that the difference in the Y-hg composition may cause the discrepancy on the association of AZFc duplication with spermatogenic failure among the studied populations.

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.

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.

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.

[Not unusual case of male genetic infertility]

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..

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.

Dysregulation of MTFR2, ATP5IF1 and BAK1 in Sertoli cells relates to idiopathic non-obstructive azoospermia via inhibiting mitochondrial fission and inducing mitochondrial dysfunction†

Non-obstructive azoospermia affects more than 10% of infertile men with over 70% patients are idiopathic with uncharacterized molecular mechanisms, which is referred as idiopathic non-obstructive azoospermia. In this study, we checked the morphology of Sertoli cell mitochondria in testis biopsies from patients with idiopathic non-obstructive azoospermia and patients with obstructive azoospermia who have normal spermiogenesis. The expression of 104 genes controlling mitochondria fission and fusion were analyzed in three gene expression datasets including a total of 60 patients with non-obstructive azoospermia. The levels of 7 candidate genes were detected in testis biopsies from 38 patients with idiopathic non-obstructive azoospermia and 24 patients with obstructive azoospermia who have normal spermatogenesis by RT-qPCR. Cell viability, apoptosis, mitochondria membrane potential, adenosine triphosphate production, oxygen consumption, and mitochondria morphology were examined in primary human Sertoli cells. Mouse spermatogonial stem cells were used to detect the cell supporting capacity of Sertoli cells. We observed that patients with idiopathic non-obstructive azoospermia had elongated mitochondria. MTFR2 and ATP5IF1 were downregulated, whereas BAK1 was upregulated in idiopathic non-obstructive azoospermia testis and Sertoli cells. Sertoli cells from patients with idiopathic non-obstructive azoospermia had reduced viability, mitochondria membrane potential, adenosine triphosphate production, oxygen consumption rate, glycolysis and increased apoptosis. Knockdown MTFR2 in Sertoli cells increased the mitochondria size. Knockdown ATP5IF1 did not change mitochondrial morphology but increased adenosine triphosphate hydrolysis. Overexpression of BAK1 reduced membrane potential and upregulated cell apoptosis. The dysregulation of all these three genes contributed to the dysfunction of Sertoli cells, which provides a clue for idiopathic non-obstructive azoospermia treatment.

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.

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.

An overview of CFTR mutation profiles and assisted reproductive technology outcomes in Chinese patients with congenital obstructive azoospermia

PURPOSE

The cystic fibrosis transmembrane conductance regulator (CFTR) is the most common causative gene attributed to congenital obstructive azoospermia (OA). The aim of this study was to conduct an epidemiological survey of congenital OA patients, to screen for CFTR mutations, and to follow their pregnancy outcomes in assisted reproductive technology (ART).

METHODS

This cohort study enrolled congenital OA patients undergoing ART and whole-exome sequencing from January 2018 to September 2023. Semen parameters, sex hormones, and seminal plasma biochemistry were evaluated. CFTR mutations identified in OA patients were analyzed. In addition, the laboratory outcomes, clinical outcomes, and neonatal outcomes were compared between OA patients carrying two CFTR mutations and the others after surgical sperm extraction-intracytoplasmic sperm injection (ICSI) treatment.

RESULTS

A total of 76 patients with congenital OA were enrolled. CFTR mutations were identified in 35 (46.1%) congenital OA patients. A total of 60 CFTR mutation sites of 27 types were identified, and 10 of them were novel. The average frequency was 1.71 (60/35) per person. The most common mutation was c.1210-11T > G (25%, 15/60). After ICSI treatment, there were no statistically significant differences in laboratory outcomes, clinical outcomes, and neonatal outcomes between OA patients carrying two CFTR mutations (n = 25) and other OA patients (n = 51).

CONCLUSION

Apart from the IVS9-5T mutation, the genetic mutation pattern of CFTR in Chinese OA patients is heterogeneous, which is significantly different from that of Caucasians. Although carrying two CFTR mutations or not had no effect on the pregnancy outcomes in OA patients after ICSI, genetic counseling is still recommended for such patients.

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.

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.

Azoospermia factor c microdeletions and outcomes of assisted reproductive technology: a systematic review and meta-analysis

OBJECTIVE

To investigate whether Azoospermia Factor c (AZFc) microdeletions affect Assisted Reproductive Technology (ART) outcomes.

DESIGN

Systematic review and meta-analysis.

SETTING

Not applicable.

PATIENTS

Infertile men with and without AZFc microdeletions.

INTERVENTION(S)

Electronic databases were searched for case-control studies reporting sperm retrieval rates and outcomes of ART in infertile men with and without AZFc microdeletions from inception to April 2023. Study quality was assessed using the Newcastle-Ottawa Scale. Summary effect sizes (odds ratio [OR] with 95% confidence interval [CI]) were calculated for both categories of infertile men.

MAIN OUTCOME MEASURES

The primary outcome was successful sperm retrieval and the secondary outcomes were outcomes of ART.

RESULTS

Case-control studies reporting sperm retrieval rates and ART outcomes in men with AZFa and AZFb deletions were unavailable. On the basis of the data from 3,807 men, sperm retrieval rates were found to be higher in men with AZFc microdeletions compared to their non-deleted counterparts [OR = 1.82, 95% CI 0.97, 3.41], but the difference was not statistically significant. A significantly lower fertilization rate (OR = 0.61, 95% CI [0.50, 0.74]), clinical pregnancy rate (OR = 0.61, 95% CI [0.42, 0.89]), and live birth rate (OR = 0.54, 95% CI [0.40, 0.72]) were observed in men with AZFc deletions compared with men without deletions. There was no statistically significant difference in rates of embryo cleavage, blastocyst formation, good-quality embryos, implantation, and miscarriage between the two groups. On correcting for female factors, the fertilization rate (OR = 0.76, 95% CI [0.71, 0.82]), cleavage rate (OR = 0.54, 95% CI [0.41, 0.72]), clinical pregnancy rate (OR = 0.39, 95% CI [0.30, 0.52]), and live birth rate (OR = 0.48, 95% CI [0.35, 0.65]) were significantly lower in men with AZFc deletions compared with controls.

CONCLUSIONS

Presence of AZFc microdeletions adversely affects outcomes of ART in infertile men. Further in-depth studies delineating the role of the AZF genes in embryonic development are necessary to understand the full-impact of this finding.

CLINICAL TRIAL REGISTRATION NUMBER

CRD42022311738.

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.

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.

Novel MEIOB pathogenic variants including a homozygous non-canonical splicing variant, cause meiotic arrest and human non-obstructive azoospermia

Non-obstructive azoospermia (NOA) is the most severe form of human male infertility, and the genetic causes of NOA with meiotic arrest remain largely unclear. In this study, we identified novel compound heterozygous MEIOB variants (c.814C > T: p.R272X and c.976G > A: p.A326T) and a previously undescribed homozygous non-canonical splicing variant of MEIOB (c.528 + 3A > C) in two NOA-affected individuals from two irrelevant Chinese families. MEIOB missense variant (p.A326T) significantly reduced protein abundance and nonsense variant (p.R272X) produced a truncated protein. Both of two variants impaired the MEIOB-SPATA22 interaction. The MEIOB non-canonical splicing variant resulted in whole Exon 6 skipping by minigene assay, which was predicted to produce a frameshift truncated protein (p.S111Rfs*32). Histological and immunostaining analysis indicated that both patients exhibited a similar phenotype as we previously reported in Meiob mutant mice, that is, absence of spermatids in seminiferous tubules and meiotic arrest. Our study identified three novel pathogenic variants of MEIOB in NOA patients, extending the mutation spectrum of the MEIOB and highlighting the contribution of meiotic recombination related genes in human fertility.

DNM3OS Enhances the Apoptosis and Senescence of Spermatogonia Associated with Nonobstructive Azoospermia by Providing miR-214-5p and Decreasing E2F2 Expression

Background

Nonobstructive azoospermia (NOA) is a complex disease characterized by the spermatogenic dysfunction of testicular tissues. The roles played by long noncoding RNAs (lncRNAs) in NOA pathogenesis have not been extensively studied.

Methods

Microarray assays were performed on samples of testicular biopsy tissue obtained from patients with NOA for the purpose of identifying differentially expressed lncRNAs and messenger RNA (mRNA) transcripts, and the results were verified by quantitative real-time polymerase chain reaction. Mouse-derived GC-1 spermatogonia (spg) cells undergoing treatment with Adriamycin (ADR) were used to investigate the biological functions of the selected lncRNAs in vitro. The target microRNAs (miRNAs) of lncRNAs and the target mRNAs of miRNAs were predicted by a bioinformatics analysis. Functional studies performed using the CCK-8 assay, EdU incorporation assay, apoptosis detection, and senescence-associated β-galactosidase (SA-β-Gal) staining were conducted using GC-1 spg cells.

Results

Totals of 2,652 lncRNAs and 2,625 mRNAs were found to be differentially expressed in the testicular tissue of NOA patients when compared with patients in a control group. Dynamin 3 opposite strand (DNM3OS) was a provider of pe-miR-214-5p that positively regulates miR-214-5p expression in GC-1 spg cells. The E2 factor (E2F) family of transcription factor 2 (E2F2) was initially predicted and subsequently verified to be a downstream gene of miR-214-5p. E2F2 expression was upregulated after DNM3OS knockdown in ADR-treated GC-1 spg cells. Moreover, knockdown of either DNM3OS or miR-214-5p significantly alleviated ADR-induced decreases in cellular activity and proliferation, as well as increases in apoptosis and senescence of mouse spermatogonial GC-1 spg cells.

Conclusions

DNM3OS was found to regulate the apoptosis and senescence of spermatogonia by providing miR-214-5p and decreasing E2F2 expression, suggesting it as a novel target for gene therapy of male infertility.

Identification of ITPR1 gene as a novel target for hsa-miR-34b-5p in non-obstructive azoospermia: a Ca2+/apoptosis pathway cross-talk

MiR-34b-5p has been reported as a non-invasive diagnostic biomarker for infertility. However, no gene targets regulating the mechanism of cation of this miRNA are known. In this study, using gene set enrichment analysis the Inositol 1,4,5-Trisphosphate Receptor Type 1 (ITPR1) gene was identified as the sole target for hsa-miR-34b-5p, and found significantly overexpressed in non-obstructive azoospermia (NOA) patients. This finding was confirmed by qRT-PCR on fresh testicular tissues from NOA patients. Then, pathway enrichment analysis as well as the diagnostic value analysis of hsa-miR-34b-5p/ITPR1 indicated ITPR1 as a hub gene in the calcium (Ca2+)-apoptosis pathway, and a valuable predictive biomarker for NOA. Moreover, gene expression and histological assays showed the association of the effects of ITPR1's increased expression on spermatogenesis failure through induction of apoptosis in NOA patients. These data suggested that the hsa-miR-34b-5p/ITPR1 axis could serve as a potential regulatory predictive biomarker for human spermatogenesis through the Ca2+-apoptosis pathway cross-talk.

AZF microdeletion affects semen parameters, sex hormone levels, and chromosome karyotypes in infertile men in Xinjiang

This study aimed to analyze the correlation between the microdeletion of different regions of the azoospermia factor (AZF) gene and semen parameters, sex hormone levels, and karyotypes in infertile males by retrospective study. This was performed to obtain a comprehensive understanding of the clinical data of AZF microdeletion in infertile males, to guide clinical diagnoses and treatments, and to improve the efficacy and safety of assisted reproductive technology. For this purpose, Fifty-seven patients with AZF microdeletions and complete data were selected from 1916 patients with AZF microdeletions in our hospital from January 2020 to August 2022. The correlation between semen parameters, sex hormone levels, and chromosome karyotypes of these 57 patients was analyzed. Results showed that among the 57 patients with AZF microdeletions, the region with the highest microdeletion rate was AZFc with 57.89%; single or combined deletions in AZFa and AZFb regions resulted in azoospermia. The deletion frequency of AZFc in the oligospermia group was significantly higher than that in the azoospermia group, and the deletion frequencies of AZFb and AZFb + c in the azoospermia group were significantly higher than those in the oligospermia group (P<0.05). There were statistically significant differences in follicle-stimulating hormone (FSH) and luteinizing hormone (LH) levels, and chromosome karyotypes between patients with azoospermia and oligospermia (P<0.05). Statistically significant differences were observed in prolactin (PRL), FSH, testosterone (T), LH levels, and chromosome karyotypes of patients in different AZF microdeletion regions (P<0.05). In conclusion, AZF microdeletions can lead to a decline in semen quality in men, and different types of deletions have different effects on semen parameters, sex hormone levels, and karyotype analysis. Further treatments should be selected based on the AZF microdeletion area.

Y chromosome microdeletions in Chinese men with infertility: prevalence, phenotypes, and intracytoplasmic sperm injection outcomes

BACKGROUND

The incidence of Y chromosome microdeletions varies among men with infertility across regions and ethnicities worldwide. However, comprehensive epidemiological studies on Y chromosome microdeletions in Chinese men with infertility are lacking. We aimed to investigate Y chromosome microdeletions prevalence among Chinese men with infertility and its correlation with intracytoplasmic sperm injection (ICSI) outcomes.

METHODS

This single-center retrospective study included 4,714 men with infertility who were evaluated at the Reproductive Center of the First Affiliated Hospital of Sun Yat-sen University between May 2017 and January 2021. Semen analysis and Y-chromosome microdeletion via multiplex polymerase chain reaction were conducted on the men. The study compared outcomes of 36 ICSI cycles from couples with male azoospermia factor (AZF)cd deletions with those of a control group, which included 72 ICSI cycles from couples without male Y chromosome microdeletions, during the same period. Both groups underwent ICSI treatment using ejaculated sperm.

RESULTS

Among 4,714 Chinese men with infertility, 3.31% had Y chromosome microdeletions. The combined deletion of sY254 and sY255 in the AZFc region and sY152 in the AZFd region was the prevalent pattern of Y chromosome microdeletion, with 3.05% detection rate. The detection rates of AZF deletions in patients with normal total sperm count, mild oligozoospermia, severe oligozoospermia, cryptozoospermia, and azoospermia were 0.17%, 1.13%, 5.53%, 71.43%, and 7.54%, respectively. Compared with the control group, the AZFcd deletion group exhibited no significant difference in the laboratory results or pregnancy outcomes of ICSI cycles using ejaculated sperm.

CONCLUSIONS

This is the largest epidemiological study on Y chromosome microdeletions in Chinese men with infertility. The study results underline the necessity for detecting Y chromosome microdeletion in men with infertility and severe sperm count abnormalities, especially those with cryptozoospermia. The combined deletion of sY254 and sY255 in the AZFc region and sY152 in the AZFd region was the most prevalent Y chromosome microdeletion pattern. Among patients with AZFcd deletion and ejaculated sperm, ICSI treatment can result in pregnancy outcomes, similar to those without AZFcd deletion.

Reduced expression of miR-221 is associated with the pro-apoptotic pathways in spermatozoa of oligospermia men

Oligospermia and asthenozoospermia, both frequent, can lead to male infertility. Oligospermia might be viewed as a milder form of azoospermia because the same mutations that produce azoospermia in some individuals also create oligospermia in other individuals. In this, we looked at different characteristics of oligospermia men, counting the level of apoptosis and a few related apoptotic and oxidative stress components, and compared them to solid controls. In this study, semen samples from healthy fertile men (n = 35) and oligospermia (n = 35) were collected, and sperm death rates in both groups were examined using flow cytometry. Also, gene expression of apoptotic and anti-apoptotic markers and miR-221 were investigated (Real-Time PCR). Moreover, for the evaluation of catalase and SOD activity and anti-inflammatory cytokines, including IL-10 and TGF-β, the specific ELISA kits and procedures were applied. As a result, higher gene and protein expression levels of PTEN, P27, and P57 were observed in patients with oligospermia. In contrast, lower mRNA expression of AKT and miR-221 was detected in this group. In addition, IL-10, TGF-β, and catalase activity were suppressed in the oligospermia group compared with healthy men samples. Moreover, the frequency of apoptosis of sperm cells is induced in patients. In conclusion, apoptosis-related markers, PTEN, and the measurement of significant and efficient oxidative stress markers like SOD and catalase in semen plasma could be considered as the critical diagnostic markers for oligospermia. Future studies will be better able to treat oligospermia by showing whether these indicators are rising or falling.

Y-chromosome haplogroups and Azoospermia Factor (AZF) analysis in Tunisian infertile male

The aim of the present study was to clarify the implication of Y chromosome genetic variations and haplogroups in Tunisian infertile men. A total of 27 Y-chromosomal binary markers partial microdeletions (gr/gr, b1/b3 and b2/b3) and copy number variation of DAZ and CDY genes in the AZFc region were analysed in 131 Tunisian infertile men with spermatogenic failure and severe reduced sperm concentrations and in 85 normospermic men as controls. Eleven different haplogroups in the overall population study (E3b2; J1J*, E1, E3b*, F, G, K, P/Q, R*, R1* and R1a1) were found. Interestingly, the J1J* haplogroup was significantly more frequent in azoo/oligospermic patients than in normospermic men (35.1% and 22.3%, respectively (p value = 0.04)). Results showed also that patients without DAZ/CDY1 copies loss and without partial microdeletions belonged to the R1 haplogroup. The relative high frequencies of two haplogroups, E3b2 (35.1%) and J (30%) was confirmed in Tunisia. We reported in the present study and for the first time, that J1J* haplogroup may confer a risk factor for infertility in the Tunisian population and we suggested that R1 haplogroup may ensure certain stability to Y-chromosome in Tunisian men.

Identification of ferroptotic genes and phenotypes in idiopathic nonobstructive azoospermia

Effective treatments for nonobstructive azoospermia (NOA), which affects 1% of all men globally, are limited by undefined pathogenic mechanisms, especially in idiopathic NOA (iNOA). Here, we tried to identify the functional ferroptosis-related genes and phenotypes involved in iNOA. Differentially expressed ferroptotic genes were identified from iNOA mRNA microarray datasets by bioinformatic analyses, and these ferroptotic genes were subsequently filtered by various algorithms. Then, receiver operating characteristic (ROC) curves were generated to evaluate the diagnostic ability of the abovementioned genes for iNOA. Generally, 11 differentially expressed ferroptotic genes were downregulated, and five genes were upregulated in iNOA samples. Four genes, including DUSP1, GPX4, HSD17B11, and SLC2A8, were technically selected and determined to be potential biomarkers for iNOA. Subsequently, similar expression levels were validated at both the RNA and protein levels in the iNOA specimens. Finally, morphologic and biochemical assays were applied to define the ferroptotic phenotypes in testes. The ferroptotic features, like shrunken mitochondria with electron-dense membranes and a reduction in cristae were observed across various cell types within iNOA patients, accompanied by the overload of ferrous ions and increased lipid peroxidation production. Our findings demonstrated that these ferroptosis genes could be involved in the underlying pathogenesis mechanisms of iNOA by regulating ferroptosis and serve as potential diagnostic biomarkers. Also, the ferroptotic phenotypes were identified in iNOA patients.

A novel missense variant in CDK5RAP2 associated with non-obstructive azoospermia

OBJECTIVE

The most severe type of male infertility is non-obstructive azoospermia (NOA), where there is no sperm in the ejaculate due to failure of spermatogenesis, affecting 10%-20% of infertile men with azoospermia. Genetic studies have identified dozens of NOA genes. The main aim of the present study is to identify a novel monogenic mutation that may cause NOA.

MATERIALS AND METHODS

We studied the pedigree of a consanguineous family with three NOA and one fertile brother by a family-based exome-sequencing, segregation analysis, insilico protein modeling and single-cell RNA sequencing data analysis.

RESULTS

Bioinformatics analysis followed by sanger sequencing revealed that three NOA brothers were homozygous for a rare missense variant in Cyclin Dependent Kinase Regulatory Subunit Associated Protein 2 (Centrosomin) CDK5RAP2 (NM_018249:exon26:c.A4003T:p.R1335W, rs761196443). Protein modeling demonstrated that CDK5RAP2, Arg1335Trp resided nearby the Microtubule Associated Protein RP/EB Family Member 1 (EB1/MAPRE1) interaction site. As a consequence of the R1335W mutation, the positively charged Arginine was replaced by to the hydrophobic tryptophan residue, possibly leading to local instability in the structure and perturbation in the CDK5RAP2-MAPRE1 interaction.

CONCLUSION

Our study reports a novel missense variant of CDK5RAP2 that segregates in homozygosity with male infertility and NOA in a consanguineous family. In silico structural predictions and gene expression data indicate a potential role of the CDK5RAP2 variant in causing defective centrosomic maturation during spermatogenesis.

A homozygous frameshift variant in SYCP2 caused meiotic arrest and non-obstructive azoospermia

Genetic causation for the majority of non-obstructive azoospermia (NOA) remains unclear. Mutations in synaptonemal complex (SC)-associated genes could cause meiotic arrest and NOA. Previous studies showed that heterozygous truncating variants in SYCP2 encoding a protein essential for SC formation, are associated with non-obstructive azoospermia and severe oligozoospermia. Herein, we showed a homozygous loss-of-function variant in SYCP2 (c.2689_2690insT) in an NOA-affected patient. And this variant was inherited from heterozygous parental carriers by natural reproduction. HE, IF, and meiotic chromosomal spread analyses demonstrated that spermatogenesis was arrested at the zygotene stage in the proband with NOA. Thus, this study revealed that SYCP2 associated with NOA segregates in an autosomal recessive inheritance pattern, rather than an autosomal dominant pattern. Furthermore, our study expanded the knowledge of variants in SYCP2 and provided new insight into understanding the genetic etiology of NOA.

Compound heterozygous variants in CFTR with potentially reducing ATP-binding ability identified in Chinese infertile brothers with isolated congenital bilateral absence of vas deferens

BACKGROUND

Isolated congenital bilateral absence of vas deferens (iCBAVD) in men results in obstructive azoospermia and is mainly caused by pathogenic variants in cystic fibrosis transmembrane conductance regulator (CFTR) or adhesion G protein-coupled receptor G2 (ADGRG2).

METHODS

The next-generation sequencing (NGS) was used to screen the mutations in the proband, and Sanger sequencings were performed to validate the compound heterozygous variant of CFTR in his family members. Protein structure simulation was performed to discover the potential pathological mechanism.

RESULTS

This study reported novel compound heterozygous CFTR mutations (NM:000492.4, Intron: 5T; c.3965_3969dupTTGGG: p.R1325Gfs*5) in two brothers with obstructive azoospermia. The compound heterozygous CFTR mutations were first screened out by NGS in an infertile male patient who exhibited iCBAVD from a nonconsanguineous Chinese family. Histological analysis of the testicular biopsy from this patient revealed normal spermatogenesis and mature spermatozoa were observed in the seminiferous tubules. Surprisingly, the same compound heterozygous CFTR mutations were also observed in his brothers who also exhibited iCBAVD, with their parents being a heterozygous carrier for the mutations, as verified by Sanger sequencing. Protein structure simulation revealed that these mutations potentially led to impaired ATP-binding ability of CFTR.

CONCLUSION

We identified novel compound heterozygous CFTR mutations in two brothers and summarized the literature regarding CFTR mutation and male infertility. Our study may contribute to the genetic diagnosis of iCBAVD and future genetic counseling.

A Comprehensive Genetic Study of Microtubule-Associated Gene Clusters for Male Infertility in a Taiwanese Cohort

Advanced reproductive technologies are utilized to identify the genetic mutations that lead to spermatogenic impairment, and allow informed genetic counseling to patients to prevent the transmission of genetic defects to offspring. The purpose of this study was to identify potential single nucleotide polymorphisms (SNPs) associated with male infertility. Genetic variants that may cause infertility are identified by combining the targeted next-generation sequencing (NGS) panel and whole exome sequencing (WES). The validation step of Sanger sequencing adds confidence to the identified variants. Our analysis revealed five distinct affected genes covering seven SNPs based on the targeted NGS panel and WES data: SPATA16 (rs16846616, 1515442, 1515441), CFTR (rs213950), KIF6 (rs2273063), STPG2 (r2903150), and DRC7 (rs3809611). Infertile men have a higher mutation rate than fertile men, especially those with azoospermia. These findings strongly support the hypothesis that the dysfunction of microtubule-related and spermatogenesis-specific genes contributes to idiopathic male infertility. The SPATA16, CFTR, KIF6, STPG2, and DRC7 mutations are associated with male infertility, specifically azoospermia, and a further examination of this genetic function is required.

X-linked RBBP7 mutation causes maturation arrest and testicular tumors

Maturation arrest (MA) is a subtype of non-obstructive azoospermia, and male infertility is a known risk factor for testicular tumors. However, the genetic basis for many affected individuals remains unknown. Here, we identified a deleterious hemizygous variant of X-linked retinoblastoma-binding protein 7 (RBBP7) as a potential key cause of MA, which was also found to be associated with the development of Leydig cell tumors. This mutation resulted in premature protein translation termination, affecting the sixth WD40 domain of the RBBP7 and the interaction of the mutated RBBP7 with histone H4. Decreased BRCA1 and increased γH2AX were observed in the proband. In mouse spermatogonial and pachytene spermatocyte-derived cells, deprivation of rbbp7 led to cell cycle arrest and apoptosis. In Drosophila, knockdown of RBBP7/Caf1-55 in germ cells resulted in complete absence of germ cells and reduced testis size, whereas knockdown of RBBP7/Caf1-55 in cyst cells resulted in hyperproliferative testicular cells. Interestingly, male infertility caused by Caf1-55 deficiency was rescued by ectopic expression of wild-type human RBBP7 but not mutant variants, suggesting the importance of RBBP7 in spermatogenesis. Our study provides insights into the mechanisms underlying the co-occurrence of MA and testicular tumors and may pave the way for innovative genetic diagnostics of these 2 diseases.

Identifying potential biomarkers for non-obstructive azoospermia using WGCNA and machine learning algorithms

Objective

The cause and mechanism of non-obstructive azoospermia (NOA) is complicated; therefore, an effective therapy strategy is yet to be developed. This study aimed to analyse the pathogenesis of NOA at the molecular biological level and to identify the core regulatory genes, which could be utilised as potential biomarkers.

Methods

Three NOA microarray datasets (GSE45885, GSE108886, and GSE145467) were collected from the GEO database and merged into training sets; a further dataset (GSE45887) was then defined as the validation set. Differential gene analysis, consensus cluster analysis, and WGCNA were used to identify preliminary signature genes; then, enrichment analysis was applied to these previously screened signature genes. Next, 4 machine learning algorithms (RF, SVM, GLM, and XGB) were used to detect potential biomarkers that are most closely associated with NOA. Finally, a diagnostic model was constructed from these potential biomarkers and visualised as a nomogram. The differential expression and predictive reliability of the biomarkers were confirmed using the validation set. Furthermore, the competing endogenous RNA network was constructed to identify the regulatory mechanisms of potential biomarkers; further, the CIBERSORT algorithm was used to calculate immune infiltration status among the samples.

Results

A total of 215 differentially expressed genes (DEGs) were identified between NOA and control groups (27 upregulated and 188 downregulated genes). The WGCNA results identified 1123 genes in the MEblue module as target genes that are highly correlated with NOA positivity. The NOA samples were divided into 2 clusters using consensus clustering; further, 1027 genes in the MEblue module, which were screened by WGCNA, were considered to be target genes that are highly correlated with NOA classification. The 129 overlapping genes were then established as signature genes. The XGB algorithm that had the maximum AUC value (AUC=0.946) and the minimum residual value was used to further screen the signature genes. IL20RB, C9orf117, HILS1, PAOX, and DZIP1 were identified as potential NOA biomarkers. This 5 biomarker model had the highest AUC value, of up to 0.982, compared to other single biomarker models; additionally, the results of this biomarker model were verified in the validation set.

Conclusions

As IL20RB, C9orf117, HILS1, PAOX, and DZIP1 have been determined to possess the strongest association with NOA, these five genes could be used as potential therapeutic targets for NOA patients. Furthermore, the model constructed using these five genes, which possessed the highest diagnostic accuracy, may be an effective biomarker model that warrants further experimental validation.

ESX1 gene as a potential candidate responsible for male infertility in nonobstructive azoospermia

Infertility is a problem that affects approximately 15% of couples, and male infertility is responsible for 40-50% of these cases. The cause of male infertility is still poorly diagnosed and treated. One of the prominent causes of male infertility is disturbed spermatogenesis, which can lead to nonobstructive azoospermia (NOA). Whole-genome sequencing (WGS) allows us to identify novel rare variants in potentially NOA-associated genes, among others, in the ESX1 gene. The aim of this study was to activate the ESX1 gene using CRISPRa technology in human germ cells (testicular seminoma cells-TCam-2). Successful activation of the ESX1 gene in TCam-2 cells using the CRISPRa system was achieved, and the expression level of the ESX1 gene was significantly higher in modified TCam-2 cells than in WT cells or the negative control with nontargeted gRNA (p < 0.01). Using RNA-seq, a network of over 50 genes potentially regulated by the ESX1 gene was determined. Finally, 6 genes, NANOG, CXCR4, RPS6KA5, CCND1, PDE1C, and LINC00662, participating in cell proliferation and differentiation were verified in azoospermic patients with and without a mutation in the ESX1 gene as well as in men with normal spermatogenesis, where inverse correlations in the expression levels of the observed genes were noted.

Altered G-Protein Transduction Protein Gene Expression in the Testis of Infertile Patients with Nonobstructive Azoospermia

Recent studies have shown that several members of the G-protein-coupled receptors (GPCR) superfamily play crucial roles in the maintenance of ion-water homeostasis of the sperm and Sertoli cells, development of the germ cells, formation of the blood barrier, and maturation of sperm. The GPCR, guanyl-nucleotide exchange factor, membrane traffic protein, and small GTPase genes were analyzed by microarray and bioinformatics (3513 sperm and Sertoli cell genes). In the microarray analyses of three human cases with different nonobstructive azoospermia sperm, the expression of GOLGA8IP, OR2AT4, PHKA1, A2M, OR56A1, SEMA3G, LRRC17, APP, ARHGAP33, RABGEF1, NPY2R, GHRHR, LTB4R2, GRIK5, OR6K6, NAPG, OR6C65, VPS35, FPR3, and ARL4A was upregulated, while expression of MARS, SIRPG, OGFR, GPR150, LRRK1, and NGEF was downregulated. There was an increase in GBP3, GBP3, TNF, TGFB3, and CLTC expression in the Sertoli cells of three human cases with NOA, whereas expression of PAQR4, RRAGD, RAC2, SERPINB8, IRPB1, MRGPRF, RASA2, SIRPG, RGS2, RAP2A, RAB2B, ARL17, SERINC4, XIAP, DENND4C, ANKRA2, CSTA, STX18, and SNAP23 were downregulated. A combined analysis of Enrich Shiny Gene Ontology (GO), STRING, and Cytoscape was used to predict proteins' molecular interactions and then to recognize master pathways. Functional enrichment analysis showed that the biological process (BP), regulation of protein metabolic process, regulation of small GTPase-mediated signal transduction were significantly expressed in up-/downregulated differentially expressed genes (DEGs) in sperm. In molecular function (MF) experiments of DEGs that were up-/downregulated, it was found that GPCR activity, guanyl ribonucleotide binding, GTPase activity and nucleoside-triphosphatase activity were overexpressed. An analysis of GO enrichment findings of Sertoli cells showed BP and MF to be common DEGs. When these gene mutations have been validated, they can be used to create new GPCR antagonists or agonists that are receptor-selective.

A rare ring chromosome 21 abnormality is associated with azoospermia in two different phenotypically normal cases

Azoospermia can be diagnosed with spermiogram analysis, and karyotyping is the golden standard to explain the etiology. In this study, we investigated two male cases with azoospermia and male infertility for chromosomal abnormalities. Their phenotypes and physical and hormonal examinations were both normal. In karyotyping G-banding and NOR staining, a rare ring chromosome 21 abnormality was detected in the cases and no microdeletion in chromosome Y. Ring abnormality, deletion size, and deleted regions were shown with subtelomeric FISH (.ish r(21)(p13q22.3?)(D21S1446-)) and array CGH analyses. Due to the findings, bioinformatics, protein, and pathway analyses were done to detect a candidate gene through common genes in two cases' deleted regions or ring chromosome 21.

[Exploring the mechanisms of ferroptosis in non-obstructive azoospermia based on bioinformatics and machine learning]

OBJECTIVE

To explor the potential mechanisms of ferroptosis involvement in non-obstructive azoospermia based on bioinformatics and machine learning methods.

METHODS

To obtain disease-related datasets and ferroptosis-related genes, we utilized the GEO database and FerrDb database, respectively. Using the R software, the disease dataset was subjected to normalization, differential analysis, and GO and KEGG enrichment analysis. The differentially expressed genes from the disease dataset were then intersected with the ferroptosis-related genes to identify common genes. Core genes were selected using three machine learning algorithms, namely LASSO, SVM-RFE, and random forest. Further analysis included exploring immune infiltration correlation, predicting target drugs, and conducting molecular docking simulations.

RESULTS

The differential analysis of the GSE45885 dataset yielded 1751 differentially expressed genes, while the GSE145467 dataset yielded 4358 differentially expressed genes. The intersection of these two gene sets resulted in a disease-related gene set consisting of 508 genes. Taking the intersection of the disease-related gene set and the ferroptosis-related gene set, we obtained 17 disease-related ferroptosis genes. After machine learning-based screening, three core genes were identified: GPX4, HSF1, and KLHDC3.

CONCLUSION

The mechanism underlying the involvement of ferroptosis in non-obstructive azoospermia may be linked to the downregulation of GPX4, HSF1, and KLHDC3 expression. This finding provides a basis for subsequent in-depth mechanistic and therapeutic studies.

[Analysis of copy number variation in AZF region of Y chromosome in patients with spermatogenic failure]

OBJECTIVE

To explore the characteristics of copy number variation (CNV) within the Y chromosome azoospermia factor (AZF) region in patients with spermatogenesis disorders in the Shenzhen area.

METHODS

A total of 123 patients with spermatogenesis disorders who had visited Shenzhen People's Hospital from January 2016 to October 2022 (including 73 patients with azoospermia and 50 patients with oligozoospermia) and 100 normal semen males were selected as the study subjects. The AZF region was detected with multiplex ligation-dependent probe amplification (MLPA), and the correlation between the CNV in the AZF region and spermatogenesis disorders was analyzed using the chi-square test or Fisher's exact test.

RESULTS

19 CNV were detected among 53 patients from the 223 samples, including 20 cases (27.40%, 20/73) from the azoospermia group, 19 cases (38%, 19/50) from the oligozoospermia group, and 14 cases (14%, 14/100) from the normal control group. In the azoospermia, oligozoospermia, and normal control groups, the detection rates for CNV related to the AZFa region (including AZFab and AZFabc) were 5.48% (4/73), 2.00% (1/50), and 0 (0/100), respectively. The detection rates for the AZFb region (including the AZFbc region) were 6.85% (5/73), 0 (0/50), and 0 (0/100), respectively. The detection rates for gr/gr deletions in the AZFc region were 2.74% (2/73), 6.00% (3/50), and 9.00% (9/100), respectively, and those for b2/b4 deletions in the AZFc region were 2.74% (2/73), 10.00% (5/50), and 0 (0/100), respectively. The detection rates for complex rearrangements in the AZFc region were 6.85% (5/73), 18.00% (9/50), and 3.00% (3/100), respectively. Statistical analysis showed no significant difference in the detection rate of gr/gr deletions between the three groups (Fisher's Exact Test value = 2.712, P = 0.249); the differences in the detection rate of b2/b4 deletions between the three groups were statistically significant (Fisher's Exact Test value = 9.489, P = 0.002); the differences in the detection rate of complex rearrangements in the AZFc region between the three groups were statistically significant (Fisher's Exact Test value = 9.493, P = 0.006). In this study, a rare AZFa region ARSLP1 gene deletion (involving SY86 deletion) was detected in a patient with oligozoospermia.

CONCLUSION

CNV in the AZFa and AZFb regions have a severe impact on spermatogenesis, but partial deletion in the AZFa region (ARSLP1 gene deletion) has a minor impact on spermatogenesis. The b2/b4 deletion and complex rearrangement in the AZFc region may be risk factors for male infertility. The gr/gr deletion may not serve as a risk factor for male infertility in the Shenzhen area.

Copy number variations (CNVs) and karyotyping analysis in males with azoospermia and oligospermia

BACKGROUND

Considering the essential roles that genetic factors play in azoospermia and oligospermia, this study aims to identify abnormal chromosomes using karyotyping and CNVs and elucidate the associated genes in patients.

METHODS

A total of 1157 azoospermia and oligospermia patients were recruited, of whom, 769 and 674 underwent next-generation sequencing (NGS) to identify CNVs and routine G-band karyotyping, respectively.

RESULTS

First, 286 patients were co-analyzed using CNV sequencing (CNV-seq) and karyotyping. Of the 725 and 432 patients with azoospermia and oligospermia, 33.8% and 48.9% had abnormal karyotypes and CNVs, respectively. In particular, 47,XXY accounted for 44.18% and 26.33% of abnormal karyotypes and CNVs, respectively, representing the most frequent genetic aberration in azoospermia and oligospermia patients. Nevertheless, big Y and small Y accounted for 7.46% and 16.67% of abnormal karyotypes, respectively. We also identified high-frequency CNVs-loci, such as Xp22.31 and 2p24.3, in azoospermia and oligospermia patients.

CONCLUSION

Sex chromosome and autosomal CNV loci, such as Xp22.31 and 2p24.3, as well as the associated genes, such as VCX and NACAP9, could be candidate spermatogenesis genes. The high-frequency abnormal karyotypes, CNV loci, and hot genes represent new targets for future research.

A Novel Frameshift Microdeletion of the TEX12 Gene Caused Infertility in Two Brothers with Nonobstructive Azoospermia

Male infertility is a growing health problem, which affects approximately 7% of the global male population. Nonobstructive azoospermia (NOA) is one of the most severe forms of male infertility caused by genetic defects, including chromosome structural abnormalities, Y chromosome microdeletions, or single-gene alterations. However, the etiology of up to 40% of NOA cases is unidentified. By whole-exome sequencing, we detected a homozygous 5-bp-deletion variant in exon 4 of the TEX12 gene (c.196-200del, p.L66fs, NM_031275.4) in two brothers with NOA of a nonconsanguineous Vietnamese family. This deletion variant of 5 nucleotides (ATTAG) results in a premature stop codon in exon 4 and truncation of the C-terminal. Segregation analysis by Sanger sequencing confirmed that the deletion variant was inherited in an autosomal recessive pattern. The 1st and 3rd infertile sons were homozygous for the deletion, whereas the 2nd fertile son and both parents were heterozygous. The new deletion mutation identified in TEX12 gene caused loss of function of TEX12 gene. The loss of TEX12 function has already caused infertility in male mice. Therefore, we concluded that the loss of TEX12 function may cause infertility in men. To our knowledge, this is the first case reported so far indicating disruption of human TEX12, which leads to infertility in men.

Integrated molecular-network analysis reveals infertility-associated key genes and transcription factors in the non-obstructive azoospermia

BACKGROUND

Male infertility is a multifactorial reproductive health problem with complex causes. Non-obstructive azoospermia (NOA) is characterized by failure of spermatogenesis, leading to the absence of spermatozoa in ejaculates. The molecular mechanism underlying the NOA is still not well understood.

OBJECTIVES

This study aims to identify the key genes involved in male infertility that could be a potential biomarker in the diagnosis and prognosis of azoospermia.

STUDY DESIGN

The microarray expression profiles dataset GSE45885 and GSE45887 were downloaded from the NCBI's Gene Expression Omnibus (GEO) database and analyzed for male infertility-associated differentially expressed genes (DEGs) using the GEO2R tool. The common DEGs between the two datasets were combined and their protein-protein interaction (PPI) network was constructed using Cytoscape to reveal the hub genes by topology and module analysis. In addition, transcription factors (TFs) and protein kinases regulating the hub genes were identified using the X2K tool. Then, the expression of the hub genes was validated by analyzing the GSE190752 microarray dataset. Further, the PPI network was screened for biological roles and enriched pathways using DAVID software.

RESULTS

About 256 DEGs associated with NOA were identified and constructed the PPI network to find the infertility-associated proteins. The biological processes linked with these proteins were spermatogenesis, cell differentiation, flagellated sperm motility, and spermatid development. The topology and module analysis of the infertility-associated protein network identified the hub genes TEX38, FAM71F, PRR30, FAM166A, LYZL6, TPPP2, ARMC12, SPACA4, and FAM205A, which were found to be upregulated in the non-obstructive azoospermia. In addition, a total of 23 transcription factors and 3 protein kinases that are regulating these key hub genes were identified. Further these hub genes expression was validated using the microarray data and found that their expression was increased in the testicular biopsies obtained from NOA subjects, compared to healthy individuals.

CONCLUSION

The identified key genes and its associated transcription factors are known to regulate the infertility-related processes in the non-obstructive azoospermia. Also, the clinical sample-based microarray data validation for the expression of these key hub genes indicates their potentiality to develop them as diagnostic or prognostic biomarkers for NOA.

Next-generation sequencing analysis of semen microbiome taxonomy in men with nonobstructive azoospermia vs. fertile controls: a pilot study

OBJECTIVES

To study how the semen microbiome profile in men with nonobstructive azoospermia (NOA) differs from that of fertile controls (FCs).

DESIGN

Using quantitative polymerase chain reaction and 16S ribosomal RNA, we sequenced semen samples from men with NOA (follicle-stimulating hormone >10 IU/mL, testis volume <10 mL) and FCs and performed a comprehensive taxonomic microbiome analysis.

SETTING

All patients were identified during evaluation at the outpatient male andrology clinic at the University of Miami.

PATIENTS

In total, 33 adult men, including 14 diagnosed with NOA and 19 with proven paternity undergoing vasectomy, were enrolled.

MAIN OUTCOME MEASURES

Bacterial species in the semen microbiome were identified.

RESULTS

Alpha-diversity was similar between the groups, suggesting similar diversity within samples, whereas beta-diversity was different, suggesting differences in taxa between samples. In the NOA men, the phyla Proteobacteria and Firmicutes were underrepresented, and Actinobacteriota were overrepresented compared with FC men. At the genus level, Enterococcus was the most common amplicon sequence variant in both groups, whereas 5 genera differed significantly between the groups, including Escherichia and Shigella, Sneathia, and Raoutella.

CONCLUSION

Our study showed significant differences in the seminal microbiome between men with NOA and fertile men. These results suggest a loss of functional symbiosis may be associated with NOA. Further research into the characterization and clinical utility of the semen microbiome and its causal role in male infertility is necessary.

Hormonal, clinical, and genetic profile of infertile patients with azoospermia in Morocco

Introduction

azoospermia affects more than 10%-15% of infertile male subjects attending the infertility center. In Morocco, there have been no studies on male infertility with azoospermia. Thereby, our objective was to evaluate the clinical, hormonal, and genetic characteristics of infertile men with azoospermia in Morocco.

Methods

we conducted a retrospective descriptive study performed with a convenience sample of 80 infertile men from 2021 to 2022, in the Assisted Reproductive Technology Unit of the Mohammed VI University Hospital Center in Oujda-Morocco. All patients with azoospermia were subjected to a quantitative hormone assay to evaluate the functionality of the sertolic and leydigial compartments. Human karyotyping and AZF microdeletion analysis are routinely performed in azoospermic patients.

Results

the results show that the mean age of patients in the study was 45.7 ± 3.5 years. Primary infertility accounts for the majority, with a rate of 96% (n=77). There were 12 cases of azoospermia of secretory origin, 22 cases of excretory origin, and 3 of undetermined origin. Azoospermia was associated with hydrocele in 29% (n=27) of cases. The average levels of FSH, LH, testosterone, and inhibin B were 15.54 ± 5.5 mIU/mL, 7.71 ± 2.7 mIU/mL, 405.09 ± 6.13 ng/dl and 38.44 ± 5.13 pg/ml, respectively. The prevalence of chromosomal abnormalities was 30.7%. Of these, the sex chromosome aneuploidy with 47, XXY karyotype (Klinefelter syndrome) accounted for 11% (n=9). The incidence of microdeletions of azoospermia factors (AZF) was 9%, and AZFc deletion was the most common at the rate of 3%.

Conclusion

our research shows that hydrocele, varicocele, and chromosomal abnormalities are the leading causes of azoospermia. In the Moroccan population, azoospermia is essentially of excretory origin.

Genetic variants underlying spermatogenic arrests in men with non-obstructive azoospermia

Spermatogenic arrest is a severe form of non-obstructive azoospermia (NOA), which occurs in 10-15% of infertile men. Interruption in spermatogenic progression at premeiotic, meiotic, or postmeiotic stage can lead to arrest in men with NOA. Recent studies have intensively focused on defining genetic variants underlying these spermatogenic arrests by making genome/exome sequencing. A number of variants were discovered in the genes involving in mitosis, meiosis, germline differentiation and other basic cellular events. Herein, defined variants in NOA cases with spermatogenic arrests and created knockout mouse models for the related genes are comprehensively reviewed. Also, importance of gene panel-based screening for NOA cases was discussed. Screening common variants in these infertile men with spermatogenic arrests may contribute to elucidating the molecular background and designing novel treatment strategies.

An artificial neural network model to diagnose non-obstructive azoospermia based on RNA-binding protein-related genes

Non-obstructive azoospermia (NOA) is a severe form of male infertility, but its pathological mechanisms and diagnostic biomarkers remain obscure. Since the dysregulation of RNA-binding proteins (RBPs) had nonnegligible effects on spermatogenesis, we aimed to investigate the functions and diagnosis values of RBPs in NOA. 58 testicular samples (control = 11, NOA = 47) from Gene Expression Omnibus (GEO) were set as the training cohort. Three public datasets, containing GSE45885 (control = 4, NOA = 27), GSE45887 (control = 4, NOA = 16), and GSE145467 (control = 10, NOA = 10), and 44 clinical samples from the local hospital (control = 27, NOA = 17) were used for validation. Through a series of bioinformatical analyses and machine learning algorithms, including genomic difference detection, protein-protein interaction network analysis, LASSO, SVM-RFE, and Boruta, DDX20 and NCBP2 were determined as significant predictors of NOA. Single-cell RNA sequencing of 432 testicular cell samples from NOA patients indicated that DDX20 and NCBP2 were associated with spermatogenesis (false discovery rate < 0.05). Based on the transcriptome expressions of DDX20 and NCBP2, we constructed multiple diagnosis models using logistic regression, random forest, and artificial neural network (ANN). The ANN model exhibited the most reliable predictive performance in the training cohort (AUC = 0.840), GSE45885 (AUC = 0.731), GSE45887 (AUC = 0.781), GSE145467 (AUC = 0.850), and local cohort (AUC = 0.623). Totally, an ANN diagnosis model based on RBP DDX20 and NCBP2 was developed and externally validated in NOA, functioning as a promising tool in clinical practice.

Constructing a seventeen-gene signature model for non-obstructive azoospermia based on integrated transcriptome analyses and WGCNA

BACKGROUND

Non-obstructive azoospermia (NOA) affects approximately 1% of the male population worldwide. The underlying mechanism and gene transcription remain unclear. This study aims to explore the potential pathogenesis for the detection and management of NOA.

METHODS

Based on four microarray datasets from the Gene Expression Omnibus database, integrated analysis and weighted correlation network analysis (WGCNA) were used to obtain the intersected common differentially expressed genes (DESs). Differential signaling pathways were identified via GO and GSVA-KEGG analyses. We constructed a seventeen-gene signature model using least absolute shrinkage and selection operation (LASSO) regression, and validated its efficacy in another two GEO datasets. Three patients with NOA and three patients with obstructive azoospermia were recruited. The mRNA levels of seven key genes were measured in testicular samples, and the gene expression profile was evaluated in the Human Protein Atlas (HPA) database.

RESULTS

In total, 388 upregulated and 795 downregulated common DEGs were identified between the NOA and control groups. ATPase activity, tubulin binding, microtubule binding, and metabolism- and immune-associated signaling pathways were significantly enriched. A seventeen-gene signature predictive model was constructed, and receiver operating characteristic (ROC) analysis showed that the area under the curve (AUC) values were 1.000 (training group), 0.901 (testing group), and 0.940 (validation set). The AUCs of seven key genes (REC8, CPS1, DHX57, RRS1, GSTA4, SI, and COX7B) were all > 0.8 in both the testing group and the validation set. The qRT-PCR results showed that consistent with the sequencing data, the mRNA levels of RRS1, GSTA4, and COX7B were upregulated, while CPS1, DHX57, and SI were downregulated in NOA. Four genes (CPS1, DHX57, RRS1, and SI) showed significant differences. Expression data from the HPA database showed the localization characteristics and trajectories of seven key genes in spermatogenic cells, Sertoli cells, and Leydig cells.

CONCLUSIONS

Our findings suggest a novel seventeen-gene signature model with a favorable predictive power, and identify seven key genes with potential as NOA-associated marker genes. Our study provides a new perspective for exploring the underlying pathological mechanism in male infertility.

Integrative bioinformatics analysis to identify novel biomarkers associated with non-obstructive azoospermia

Aim

This study aimed to identify autophagy-related genes (ARGs) associated with non-obstructive azoospermia and explore the underlying molecular mechanisms.

Methods

Two datasets associated with azoospermia were downloaded from the Gene Expression Omnibus database, and ARGs were obtained from the Human Autophagy-dedicated Database. Autophagy-related differentially expressed genes were identified in the azoospermia and control groups. These genes were subjected to Gene Ontology and Kyoto Encyclopedia of Genes and Genomes, protein–protein interaction (PPI) network, and functional similarity analyses. After identifying the hub genes, immune infiltration and hub gene–RNA-binding protein (RBP)–transcription factor (TF)–miRNA–drug interactions were analyzed.

Results

A total 46 differentially expressed ARGs were identified between the azoospermia and control groups. These genes were enriched in autophagy-associated functions and pathways. Eight hub genes were selected from the PPI network. Functional similarity analysis revealed that HSPA5 may play a key role in azoospermia. Immune cell infiltration analysis revealed that activated dendritic cells were significantly decreased in the azoospermia group compared to those in the control groups. Hub genes, especially ATG3, KIAA0652, MAPK1, and EGFR were strongly correlated with immune cell infiltration. Finally, a hub gene–miRNA–TF–RBP–drug network was constructed.

Conclusion

The eight hub genes, including EGFR, HSPA5, ATG3, KIAA0652, and MAPK1, may serve as biomarkers for the diagnosis and treatment of azoospermia. The study findings suggest potential targets and mechanisms for the occurrence and development of this disease.

[Ion Torrent PGM sequencing for detection of Y chromosome microdeletion in 87 cases of azoospermia]

OBJECTIVE

To explore the feasibility of Ion Torrent PGM sequencing in detection of Y chromosome microdeletion.

METHODS

We enrolled 87 infertility patients with non-obstructive azoospermia (NOA) in this study and analyzed their routine semen parameters, reproductive hormone levels and chromosomal karyotypes. We detected Y chromosome microdeletion in the patients by Ion Torrent PGM sequencing and multiplex PCR, and compared the detection rates between the two methods.

RESULTS

Ion Torrent PGM sequencing achieved a significantly higher detection rate of Y chromosome microdeletion than multiplex PCR (49.4% vs 12.6%, P < 0.05). The cases of AZF deletion detected by Ion Torrent PGM sequencing included all those detected by multiplex PCR, and the deletion sites were completely consistent. In addition, 14 male infertility-related gene mutations were detected in 24 of the 87 patients, with a total positive rate of 27.59%.

CONCLUSION

Ion Torrent PGM sequencing can significantly improve the detection rate of Y chromosome microdeletion in infertility patients with NOA, detect a variety of male infertility-related gene mutations, and therefore contribute to the diagnosis of azoospermia.