Management of non-obstructive azoospermia

Association of testicular histopathology with sperm retrieval success rates in men with idiopathic non-obstructive azoospermia

INTRODUCTION

Infertility is a major public health issue, with male factors alone contributing to 20-30% of cases. Non-obstructive azoospermia (NOA) is the most severe form, and although techniques like microdissection testicular sperm extraction (mTESE) offer hope, it remains challenging due to its uncertain causes. This study investigates the correlation between testicular histopathology and clinical parameters to enhance sperm retrieval (SR) prediction.

MATERIALS AND METHODS

We reviewed 57 azoospermic men from Hanoi Medical University Hospital, recruited between January 2021 and September 2023. Inclusion criteria were confirmed azoospermia and exclusion of known NOA causes. All underwent mTESE with testicular biopsies classified into four histopathological patterns.

RESULTS

The patients' mean age was 31.75 ± 5.19 years. SR was successful in 19.3% (11/57). Higher follicle-stimulating hormone (FSH) levels were noted in SR-positive men (p = 0.02). Sertoli cell-only syndrome (SCOS) was the most common pattern. While we found a significant difference in SR rate between testicular histopathology, multivariate analysis showed no strong association. However, FSH levels were predictive of histopathology patterns.

CONCLUSIONS

Idiopathic NOA (iNOA) represents over 60% of azoospermia cases. mTESE remains the gold standard, and FSH levels may help predict testicular histopathology patterns and improving patients prognosis of SR outcomes.

Profiling of circulating extracellular vesicle microRNAs reveals diagnostic potential and pathways in non-obstructive and obstructive azoospermia†

The accurate diagnosis of non-obstructive azoospermia and obstructive azoospermia is crucial for selecting appropriate clinical treatments. This study aimed to investigate the pivotal role of microRNAs in circulating plasma extracellular vesicles in distinguishing between non-obstructive azoospermia and obstructive azoospermia, as well as uncovering the signaling pathways involved in azoospermia pathogenesis. In this study, differential expression of extracellular vesicle miR-513c-5p and miR-202-5p was observed between non-obstructive azoospermia and obstructive azoospermia patients, while the selenocompound metabolism pathway could be affected in azoospermia through Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analysis. The predictive power of these microRNAs was evaluated using receiver characteristic operator-area under the curve analysis, demonstrating promising sensitivity, specificity, and area under the curve values. A binomial regression equation incorporating circulating plasma levels of extracellular vesicles miR-202-5p and miR-513c-5p along with follicle-stimulating hormone was calculated to provide a clinically applicable method for diagnosing non-obstructive azoospermia and obstructive azoospermia. This study presents a potentially non-invasive testing approach for distinguishing between non-obstructive azoospermia and obstructive azoospermia, offering a possibly valuable tool for clinical practice.

Harnessing the potential of tissue engineering to target male infertility: Insights into testicular regeneration

Male infertility is among one of the most challenging health concerns in the world. Traditional therapeutic interventions such as semen and testicular tissue cryopreservation aim to restore or preserve male fertility. However, these methods are subject to limitations that impact their efficacy and are infeasible in cases such as patients who cannot produce mature sperm due to genetic or pathological disorders. Moreover, with the number of cases of prepubertal boys who must undergo gonadotoxic treatments rising, alternatives have been sought for fertility preservation to enhance reproductive rates in vitro and in vivo. Tissue engineering is a promising area that can address aspects that current therapies may not fully encompass through the creation of bioartificial testicular structures or 3D culture systems that allow the establishment of the essential conditions for sperm production. This study aims to first give a brief overview of stem cell therapy in treating male infertility and then go more in-depth regarding the novel methods and procedures based on tissue engineering that have the potential to offer new treatments for infertility caused by testicular disorders and defects.

Future prospects for the advancement of treatment of men with NOA: focus on gene editing, artificial sperm, stem cells, and use of imaging

Nonobstructive azoospermia (NOA) affects about 60% of men with azoospermia, representing a severe form of male infertility. The current approach to manage NOA primarily involves testicular sperm retrieval methods such as conventional testicular sperm extraction (c-TESE) and microdissection testicular sperm extraction (micro-TESE). While combining testicular sperm retrieval with intracytoplasmic sperm injection (ICSI) offers hope for patients, the overall sperm retrieval rate (SRR) stands at around 50%. In cases where micro-TESE fails to retrieve sperm, limited options, like donor sperm or adoption, can be problematic in certain cultural contexts. This paper delves into prospective treatments for NOA management. Gene editing technologies, particularly clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated (Cas) protein 9 (CRISPR/Cas9), hold potential for correcting genetic mutations underlying testicular dysfunction. However, these technologies face challenges due to their complexity, potential off-target effects, ethical concerns, and affordability. This calls for research to address key challenges associated with NOA management within the clinical settings. This also necessitate ongoing research essential for developing more sensitive diagnostic tests, validating novel treatments, and customizing current treatment strategies for individual patients. This review concluded that the future of NOA management may entail a combination of these treatment options, tailored to each patient's unique circumstances, providing a comprehensive approach to address NOA challenges.

The effect of intratesticular autologous platelet-rich plasma injection on sperm retrieval rates and in vitro fertilization outcomes in couples with non-obstructive azoospermia

AIM

To assess the efficacy of intratesticular injection of autologous platelet-rich plasma (PRP) in men with non-obstructive azoospermia (NOA) and a history of failed microdissection-testicular sperm extraction (mTESE) procedures.

METHODS

A prospective case series of a cohort study was conducted involving couples diagnosed with NOA. Patients with at least one failed mTESE procedure were included. Intratesticular PRP injection was performed using a standardized protocol. Follow-up assessments included sperm analysis, hormonal evaluation, and in vitro fertilization (IVF) outcomes.

RESULTS

Data from 177 men with NOA were analyzed, with 135 patients meeting eligibility criteria. PRP treatment resulted in positive sperm retrieval rates of 27.5% in patients with one prior failed mTESE procedure and 16.4% in patients with two or more failed attempts. IVF outcomes showed fertilization rates of 86.4% and 100.0% in respective groups, with pregnancy rates of 36.8% and 22.2% per embryo transfer. Histopathological examination post-mTESE revealed varied patterns, including Sertoli cell-only syndrome and maturation arrest.

CONCLUSIONS

Intratesticular PRP injection shows promise as a potential therapeutic approach for NOA patients with prior failed mTESE procedures, demonstrating improved sperm retrieval rates and favorable IVF outcomes. Further randomized controlled trials are warranted to validate these findings and refine the technique's efficacy in male infertility management to answer the question of whether PRP could significantly improve the second attempt retrieval rate.

Identification and validation of SHC1 and FGFR1 as novel immune-related oxidative stress biomarkers of non-obstructive azoospermia

Background

Non-obstructive azoospermia (NOA) is a major contributor of male infertility. Herein, we used existing datasets to identify novel biomarkers for the diagnosis and prognosis of NOA, which could have great significance in the field of male infertility.

Methods

NOA datasets were obtained from the Gene Expression Omnibus (GEO) database. CIBERSORT was utilized to analyze the distributions of 22 immune cell populations. Hub genes were identified by applying weighted gene co-expression network analysis (WGCNA), machine learning methods, and protein-protein interaction (PPI) network analysis. The expression of hub genes was verified in external datasets and was assessed by receiver operating characteristic (ROC) curve analysis. Gene set enrichment analysis (GSEA) was applied to explore the important functions and pathways of hub genes. The mRNA-microRNA (miRNA)-transcription factors (TFs) regulatory network and potential drugs were predicted based on hub genes. Single-cell RNA sequencing data from the testes of patients with NOA were applied for analyzing the distribution of hub genes in single-cell clusters. Furthermore, testis tissue samples were obtained from patients with NOA and obstructive azoospermia (OA) who underwent testicular biopsy. RT-PCR and Western blot were used to validate hub gene expression.

Results

Two immune-related oxidative stress hub genes (SHC1 and FGFR1) were identified. Both hub genes were highly expressed in NOA samples compared to control samples. ROC curve analysis showed a remarkable prediction ability (AUCs > 0.8). GSEA revealed that hub genes were predominantly enriched in toll-like receptor and Wnt signaling pathways. A total of 24 TFs, 82 miRNAs, and 111 potential drugs were predicted based on two hub genes. Single-cell RNA sequencing data in NOA patients indicated that SHC1 and FGFR1 were highly expressed in endothelial cells and Leydig cells, respectively. RT-PCR and Western blot results showed that mRNA and protein levels of both hub genes were significantly upregulated in NOA testis tissue samples, which agree with the findings from analysis of the microarray data.

Conclusion

It appears that SHC1 and FGFR1 could be significant immune-related oxidative stress biomarkers for detecting and managing patients with NOA. Our findings provide a novel viewpoint for illustrating potential pathogenesis in men suffering from infertility.

Human sperm RNA in male infertility

The function and value of specific sperm RNAs in apparently idiopathic male infertility are currently poorly understood. Whether differences exist in the sperm RNA profile between patients with infertility and fertile men needs clarification. Similarly, the utility of sperm RNAs in predicting successful sperm retrieval and assisted reproductive technique (ART) outcome is unknown. Patients with infertility and fertile individuals seem to have differences in the expression of non-coding RNAs that regulate genes controlling spermatogenesis. Several RNAs seem to influence embryo quality and development. Also, RNA types seem to predict successful sperm retrieval in patients with azoospermia. These findings suggest that sperm RNAs could influence decision-making during the management of patients with infertility. This evidence might help to identify possible therapeutic approaches aimed at modulating the expression of dysregulated genes in patients with infertility. Performing prospective studies with large sample sizes is necessary to investigate cost-effective panels consisting of proven molecular targets to ensure that this evidence can be translated to clinical practice.

A review of testicular histopathology in nonobstructive azoospermia

One major challenge in male factor infertility is nonobstructive azoospermia (NOA), which is characterized by spermatozoa-deficient semen without physical duct blockage. This review offers a thorough overview of the histopathology of the testes in NOA cases, clarifying its complex etiology and emphasizing the possible value of histopathology inspection for both diagnosis and treatment. Variable histopathological findings have been linked to NOA, such as tubular hyalinization, Sertoli cell-only syndrome, hypospermatogenesis, and germ cell arrest. Understanding the pathophysiology and forecasting the effectiveness of treatment are further enhanced by both morphometric and ultrastructural analyses. The potential significance of testicular biopsy in forecasting reproductive outcomes is assessed, especially concerning assisted reproductive technologies like intracytoplasmic sperm injection (ICSI). Besides, testicular microlithiasis, serum hormone profiles, and testicular size are investigated concerning NOA histopathology. It is concluded that understanding the histopathological patterns in NOA is crucial for its accurate diagnosis and appropriate management. Further research is still warranted to improve understanding of the complex pathophysiology underlying NOA.

Improving Fertility in Non-obstructive Azoospermia: Results from an Autologous Bone Mar-row-Derived Mesenchymal Stromal/Stem Cell Phase I Clinical Trial

BACKGROUND

In this phase I clinical trial, our primary objective was to develop an innovative therapeutic approach utilizing autologous bone marrow-derived mesenchymal stromal/stem cells (BM-MSCs) for the treatment of nonobstructive azoospermia (NOA). Additionally, we aimed to assess the feasibility and safety of this approach.

MATERIALS AND METHODS

We recruited 80 participants in this non-randomized, open-label clinical trial, including patients undergoing NOA treatment using autologous BM-MSCs (n=40) and those receiving hormone therapy as a control group (n=40). Detailed participant characteristics, such as age, baseline hormonal profiles, etiology of NOA, and medical history, were thoroughly documented. Autotransplantation of BM-MSCs into the testicular network was achieved using microsurgical testicular sperm extraction (microTESE). Semen analysis and hormonal assessments were performed both before and six months after treatment. Additionally, we conducted an in-silico analysis to explore potential protein-protein interactions between exosomes secreted from BM-MSCs and receptors present in human seminiferous tubule cells.

RESULTS

Our results revealed significant improvements following treatment, including increased testosterone and inhibin B levels, elevated sperm concentration, and reduced levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH), and prolactin. Notably, in nine patients (22.5%) previously diagnosed with secondary infertility and exhibiting azoospermia before treatment, the proposed approach yielded successful outcomes, as indicated by hormonal profile changes over six months. Importantly, these improvements were achieved without complications. Additionally, our in-silico analysis identified potential binding interactions between the protein content of BM-MSC-derived exosomes and receptors integral to spermatogenesis.

CONCLUSION

Autotransplantation of BM-MSCs into the testicular network using microTESE in NOA patients led to the regeneration of seminiferous tubules and the regulation of hormonal profiles governing spermatogenesis. Our findings support the safety and effectiveness of autologous BM-MSCs as a promising treatment modality for NOA, with a particular focus on the achieved outcomes in patients with secondary infertility (registration number: IRCT20190519043634N1).

APHRODITE criteria: addressing male patients with hypogonadism and/or infertility owing to altered idiopathic testicular function

RESEARCH QUESTION

Can a novel classification system of the infertile male - 'APHRODITE' (Addressing male Patients with Hypogonadism and/or infeRtility Owing to altereD, Idiopathic TEsticular function) - stratify different subgroups of male infertility to help scientists to design clinical trials on the hormonal treatment of male infertility, and clinicians to counsel and treat the endocrinological imbalances in men and, ultimately, increase the chances of natural and assisted conception?

DESIGN

A collaboration between andrologists, reproductive urologists and gynaecologists, with specialization in reproductive medicine and expertise in male infertility, led to the development of the APHRODITE criteria through an iterative consensus process based on clinical patient descriptions and the results of routine laboratory tests, including semen analysis and hormonal testing.

RESULTS

Five patient groups were delineated according to the APHRODITE criteria; (1) Hypogonadotrophic hypogonadism (acquired and congenital); (2) Idiopathic male infertility with lowered semen analysis parameters, normal serum FSH and normal serum total testosterone concentrations; (3) A hypogonadal state with lowered semen analysis parameters, normal FSH and reduced total testosterone concentrations; (4) Lowered semen analysis parameters, elevated FSH concentrations and reduced or normal total testosterone concentrations; and (5) Unexplained male infertility in the context of unexplained couple infertility.

CONCLUSION

The APHRODITE criteria offer a novel and standardized patient stratification system for male infertility independent of aetiology and/or altered spermatogenesis, facilitating communication among clinicians, researchers and patients to improve reproductive outcomes following hormonal therapy. APHRODITE is proposed as a basis for future trials of the hormonal treatment of male infertility.

Molecular mechanisms of cellular dysfunction in testes from men with non-obstructive azoospermia

Male factor infertility affects 50% of infertile couples worldwide; the most severe form, non-obstructive azoospermia (NOA), affects 10-15% of infertile males. Treatment for individuals with NOA is limited to microsurgical sperm extraction paired with in vitro fertilization intracytoplasmic sperm injection. Unfortunately, spermatozoa are only retrieved in ~50% of patients, resulting in live birth rates of 21-46%. Regenerative therapies could provide a solution; however, understanding the cell-type-specific mechanisms of cellular dysfunction is a fundamental necessity to develop precision medicine strategies that could overcome these abnormalities and promote regeneration of spermatogenesis. A number of mechanisms of cellular dysfunction have been elucidated in NOA testicular cells. These mechanisms include abnormalities in both somatic cells and germ cells in NOA testes, such as somatic cell immaturity, aberrant growth factor signalling, increased inflammation, increased apoptosis and abnormal extracellular matrix regulation. Future cell-type-specific investigations in identifying modulators of cellular transcription and translation will be key to understanding upstream dysregulation, and these studies will require development of in vitro models to functionally interrogate spermatogenic niche dysfunction in both somatic and germ cells.

Derivation of human primordial germ cell-like cells in an embryonic-like culture

Primordial germ cells (PGCs) are the embryonic precursors of sperm and eggs. They transmit genetic and epigenetic information across generations. Given the prominent role of germline defects in diseases such as infertility, detailed understanding of human PGC (hPGC) development has important implications in reproductive medicine and studying human evolution. Yet, hPGC specification remains an elusive process. Here, we report the induction of hPGC-like cells (hPGCLCs) in a bioengineered human pluripotent stem cell (hPSC) culture that mimics peri-implantation human development. In this culture, amniotic ectoderm-like cells (AMLCs), derived from hPSCs, induce hPGCLC specification from hPSCs through paracrine signaling downstream of ISL1. Our data further show functional roles of NODAL, WNT, and BMP signaling in hPGCLC induction. hPGCLCs are successfully derived from eight non-obstructive azoospermia (NOA) participant-derived hPSC lines using this biomimetic platform, demonstrating its promise for screening applications.

A Rare 46,X,t(Y;10)(q12;p14) Balanced Translocation in Non-Obstructive Azoospermic Patient with Elevated FSH and LH Levels

Structural chromosomal aberrations like translocations have been shown to cause spermatogenic failure. We report a rare 46,X,t(Y;10)(q12;p14) balanced translocation in an otherwise healthy non-obstructive azoospermic male with high follicle-stimulating hormone (26.65 IU/L) and high luteinizing hormone (13.58 IU/L). The patient was referred to us after clinical, hormonal, and histopathological investigations to identify chromosomal abnormalities by karyotyping and fluorescence in situ hybridization (FISH). Analysis of the banding pattern by karyotyping followed by FISH confirmed reciprocal translocation and identified the breakpoints at Yq heterochromatin (Yq12) and 10p14. Further molecular tests including AZF microdeletion assay were done, and the results, which showed no mutations in the analyzed genes, were provided by the referring doctor. Thus, our study points to the importance of conventional cytogenetic techniques in the preliminary evaluation of a genetic abnormality in cases of infertility and would help the patient make an informed decision before pursuing assisted reproductive technology.

Microdissection Testicular Sperm Extraction

Nonobstructive azoospermia (NOA) is among the most common causes of male infertility. For men with NOA seeking fertility treatment, microdissection testicular sperm extraction (microTESE) is the best option for retrieving sperm, which can be used with in vitro fertilization-intracytoplasmic sperm injection to achieve pregnancy in their partner. With the aid of the operating microscope, microTESE allows for thorough evaluation of the testis tissue and selection of seminiferous tubules that appear most capable of sperm production. Rates of success with microTESE vary depending on the underlying cause of NOA and the center at which the procedure is performed. Not all patients are candidates for microTESE, and those who are candidates should be counseled on the likelihood of sperm retrieval and the potential for changes in postoperative testis function.

Current Progress in Stem Cell Therapy for Male Infertility

Infertility has become one of the most common issues worldwide, which has negatively affected society and infertile couples. Meanwhile, male infertility is responsible for about 50% of infertility. Accordingly, a great number of researchers have focused on its treatment during the last few years; however, current therapies such as assisted reproductive technology (ART) are not effective enough in treating male infertility. Because of their self-renewal and differentiation capabilities and unlimited sources, stem cells have recently raised great hope in the treatment of reproductive system disorders. Stem cells are undifferentiated cells that can induce different numbers of specific cells, such as male and female gametes, demonstrating their potential application in the treatment of infertility. The present review aimed at identifying the causes and potential factors that influence male fertility. Besides, we highlighted the recent studies that investigated the efficiency of stem cells such as spermatogonial stem cells (SSCs), embryonic stem cells (ESCs), very small embryonic-like stem cells (VSELs), induced pluripotent stem cells (iPSCs), and mesenchymal stem cells (MSCs) in the treatment of various types of male infertility.

Evaluating the Predictive Value of Diagnostic Testicular Biopsy for Sperm Retrieval Outcomes in Men with Non-Obstructive Azoospermia

BACKGROUND

Non-obstructive azoospermia (NOA) presents a challenge in male infertility management. This study aimed to assess the efficacy of diagnostic testicular biopsy (DTB) in predicting sperm retrieval success via therapeutic testicular biopsy (TTB) and to understand the role of systemic inflammation in microdissection testicular sperm extraction (mTESE) outcomes.

METHODS

A retrospective analysis was conducted on 50 NOA males who underwent mTESE at the University of Ioannina's Department of Urology from January 2017 to December 2019. All participants underwent thorough medical evaluations, including semen analyses and endocrinological assessments.

RESULTS

DTB did not detect spermatozoa in half of the patients who later showed positive sperm findings in TTB. Preoperative variables, such as age, plasma levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH), total testosterone (TT), prolactin (PRL), estradiol (E2), and inflammation biomarkers (neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), monocyte-eosinophil ratio (MER)), were not consistently predictive of sperm retrieval success. Notably, TTB-negative patients had elevated NLR and PLR values, suggesting a possible link between systemic inflammation and reduced sperm retrieval during mTESE.

CONCLUSIONS

The findings question the necessity of an initial DTB, which might provide misleading results. A negative DTB should not deter further TTB or intracytoplasmic sperm injection (ICSI) attempts. The study emphasizes the need for further research to refine diagnostic approaches and deepen the understanding of factors influencing sperm retrieval in NOA patients, ultimately enhancing their prospects of biological parenthood.

QTLs and Candidate Genes Associated with Semen Traits in Merino Sheep

Ram semen traits play a significant role in conception outcomes, which in turn may influence reproductive efficiency and the overall productivity and profitability of sheep enterprises. Since hundreds of ewes may be inseminated from a single ejaculate, it is important to evaluate semen quality prior to use in sheep breeding programs. Given that semen traits have been found to be heritable, genetic variation likely contributes to the variability observed in these traits. Identifying such genetic variants could provide novel insights into the molecular mechanisms underlying variability in semen traits. Therefore, this study aimed to identify quantitative trait loci (QTLs) associated with semen traits in Merino sheep. A genome-wide association study (GWAS) was undertaken using 4506 semen collection records from 246 Merino rams collected between January 2002 and May 2021. The R package RepeatABEL was used to perform a GWAS for semen volume, gross motility, concentration, and percent post-thaw motility. A total of 35 QTLs, located on 16 Ovis aries autosomes (OARs), were significantly associated with either of the four semen traits in this study. A total of 89, 95, 33, and 73 candidate genes were identified, via modified Bonferroni, within the QTLs significantly associated with volume, gross motility, concentration, and percent post-thaw motility, respectively. Among the candidate genes identified, SORD, SH2B1, and NT5E have been previously described to significantly influence spermatogenesis, spermatozoal motility, and high percent post-thaw motility, respectively. Several candidate genes identified could potentially influence ram semen traits based on existing evidence in the literature. As such, validation of these putative candidates may offer the potential to develop future strategies to improve sheep reproductive efficiency. Furthermore, Merino ram semen traits are lowly heritable (0.071-0.139), and thus may be improved by selective breeding.

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.

Deciphering the Molecular Characteristics of Human Idiopathic Nonobstructive Azoospermia from the Perspective of Germ Cells

Nonobstructive azoospermia (NOA) is one of the most important causes of male infertility, accounting for 10-15% of infertile men worldwide. Among these, more than 70% of cases are idiopathic NOA (iNOA), whose pathogenesis and molecular basis remain unknown. This work profiles 3696 human testicular single-cell transcriptomes from 17 iNOA patients, which are classified into four classes with different arrest periods and variable cell proportions based on the gene expression patterns and pathological features. Genes related to the cell cycle, energy production, and gamete generation show obvious abnormalities in iNOA germ cells. This work identifies several candidate causal genes for iNOA, including CD164, LELP1, and TEX38, which are significantly downregulated in iNOA germ cells. Notably, CD164 knockdown promotes apoptosis in spermatogonia. Cellular communications between spermatogonial stem cells and Sertoli cells are disturbed in iNOA patients. Moreover, BOD1L2, C1orf194, and KRTCAP2 are found to indicate testicular spermatogenic capacity in a variety of testicular diseases, such as Y-chromosome microdeletions and Klinefelter syndrome. In general, this study analyzes the pathogenesis of iNOA from the perspective of germ cell development, transcription factor (TF) regulatory networks, as well as germ cell and somatic cell interactions, which provides new ideas for clinical diagnosis.

STK33 phosphorylates fibrous sheath protein AKAP3/4 to regulate sperm flagella assembly in spermiogenesis

Spermatogenesis defects are important for male infertility; however, the etiology and pathogenesis are still unknown. Herein, we identified two loss of function mutations of STK33 in 7 individuals with non-obstructive azoospermia. Further functional studies of these frameshift and nonsense mutations revealed that Stk33^-/KI male mice were sterile, and Stk33^-/KI sperm were abnormal with defects in the mitochondrial sheath (MS), fibrous sheath (FS), outer dense fiber (ODF) and axoneme. Stk33^KI/KI male mice were subfertile and had oligoasthenozoospermia. Differential phosphoproteomic analysis and in vitro kinase assay identified novel phosphorylation substrates of STK33, fibrous sheath components AKAP3 and AKAP4, whose expression levels decreased in testis after deletion of Stk33. STK33 regulated the phosphorylation of AKAP3/4, affected the assembly of fibrous sheath in the sperm, and played an essential role in spermiogenesis and male infertility.

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.

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.

Transcriptomic analysis of the Non-Obstructive Azoospermia (NOA) to address gene expression regulation in human testis

There is a need to understand the molecular basis of testes under Non-Obstructive Azoospermia (NOA), a state of failed spermatogenesis. There has been a lack of attention to the transcriptome at the level of alternatively spliced mRNAs (iso-mRNAs) and the mechanism of gene expression regulation. Hence, we aimed to establish a reliable iso-mRNA profile of NOA-testes, and explore molecular mechanisms - especially those related to gene expression regulation. We sequenced mRNAs from testicular samples of donors with complete spermatogenesis (control samples) and a failure of spermatogenesis (NOA samples). We identified differentially expressed genes and their iso-mRNAs via standard NGS data analyses. We then listed these iso-mRNAs hierarchically based on the extent of consistency of differential quantities across samples and groups, and validated the lists via RT-qPCRs (for 80 iso-mRNAs). In addition, we performed extensive bioinformatic analysis of the splicing features, domains, interactions, and functions of differentially expressed genes and iso-mRNAs. Many top-ranking down-regulated genes and iso-mRNAs, i.e., those down-regulated more consistently across the NOA samples, are associated with mitosis, replication, meiosis, cilium, RNA regulation, and post-translational modifications such as ubiquitination and phosphorylation. Most down-regulated iso-mRNAs correspond to full-length proteins that include all expected domains. The predominance of alternative promoters and termination sites in these iso-mRNAs indicate their gene expression regulation via promoters and UTRs. We compiled a new, comprehensive list of human transcription factors (TFs) and used it to identify TF-'TF gene' interactions with potential significance in down-regulating genes under the NOA condition. The results indicate that RAD51 suppression by HSF4 prevents SP1-activation, and SP1, in turn, could regulate multiple TF genes. This potential regulatory axis and other TF interactions identified in this study could explain the down-regulation of multiple genes in NOA-testes. Such molecular interactions may also have key regulatory roles during normal human spermatogenesis.

IVF outcomes following ICSI cycles using testicular sperm in obstructive (OA) vs. non-obstructive azoospermia (NOA) and the impact of maternal and paternal age: a SART CORS data registry

PURPOSE

To assess the differences in IVF outcomes between couples with obstructive azoospermia (OA), non-obstructive azoospermia (NOA), and male factor (MF).

METHODS

Using the SART CORS data from 2016 to 2017, we included all initial autologous cycles with a diagnosis of male factor with ejaculated and surgically obtained sperm. We analyzed 71,121 cycles, including 3467 with a diagnosis of azoospermia and 67,654 with other non-azoospermic MF. Using a multivariate binomial regression, we estimated adjusted risk ratios comparing outcomes for ICSI cycles using surgically acquired (OA and NOA) versus ejaculated sperm (MF). Outcomes reported per initial cycle included clinical pregnancy, live birth, biochemical pregnancy, and miscarriage. Outcomes reported per singleton pregnancy included full-term delivery (≥ 37 weeks), normal birth weight (≥ 2500 g), and delivery method.

RESULTS

After frozen embryo transfers (FET), patients with NOA had 7% higher odds of live birth compared to MF (aOR 1.23 (0.94-1.74)), and those with OA had 2.6% lower chance of live birth compared to MF (aOR 0.73 (95%CI 0.5-1.05)). After fresh ET, patients with NOA had 5% higher chance of live birth (aOR 1.11 (0.9-1.36)), and those with OA had a 2.5% higher chance of live birth (aOR 1.10 (95%CI 0.89-1.34)) compared to MF. All three subgroups had lower fresh live birth rates (LBR) compared to FETs.

CONCLUSION

Couples with either NOA or OA have overall comparable ART and perinatal outcomes to couples with MF, and their success is primarily dependent on both patient's and partner's age.

Human in vitro spermatogenesis as a regenerative therapy - where do we stand?

Spermatogenesis involves precise temporal and spatial gene expression and cell signalling to reach a coordinated balance between self-renewal and differentiation of spermatogonial stem cells through various germ cell states including mitosis, and meiosis I and II, which result in the generation of haploid cells with a unique genetic identity. Subsequently, these round spermatids undergo a series of morphological changes to shed excess cytoplast, develop a midpiece and tail, and undergo DNA repackaging to eventually form millions of spermatozoa. The goal of recreating this process in vitro has been pursued since the 1920s as a tool to treat male factor infertility in patients with azoospermia. Continued advances in reproductive bioengineering led to successful generation of mature, functional sperm in mice and, in the past 3 years, in humans. Multiple approaches to study human in vitro spermatogenesis have been proposed, but technical and ethical obstacles have limited the ability to complete spermiogenesis, and further work is needed to establish a robust culture system for clinical application.

The use of hormone stimulation in male infertility

Infertility affects 15% of couples worldwide and in approximately 50% of cases the cause is secondary to an abnormality of the sperm. However, treatment options for male infertility are limited and empirical use of hormone stimulation has been utilised. We review the contemporary data regarding the application of hormone stimulation to treat male infertility. There is strong evidence supporting the use of hormone stimulation in hypogonadotropic hypogonadism but there is inadequate evidence for all other indications.

Micro-TESE surgery combined with ICSI regimen in the treatment of non-obstructive azoospermia patients and its effect analysis

This study aimed to analyze the clinical effects of microdissection testicular sperm extraction (micro-TESE) surgery combined with an intracytoplasmic sperm injection (ICSI) regimen in the treatment of non-obstructive azoospermia (NOA) patients with different etiologies. In total, 128 NOA patients participated in this study, in which they received infertility treatment by micro-TESE surgery combined with an ICSI regimen, and all patients were divided into three groups [the Klinefelter syndrome (KS), the idiopathic and the secondary NOA groups]. In addition, the sperm retrieval rate (SRR), fertilization rate, embryo development status and clinical treatment effects were analyzed. Among the 128 NOA patients, the SRR of KS NOA patients was 48.65%, those of idiopathic and the secondary patients were 33.82% and 73.91%, respectively. Regardless of etiologies, there was no correlation with age, hormone value or testicular volume. Further analysis showed that the SRR of the KS group was positively related with testosterone (T) values, and the SRR of the secondary group had a positive relationship with follicle-stimulating hormone or luteinizing hormone values. In the subsequent clinical treatment, the retrieved sperm was subjected to ICSI and achieved good treatment effects, especially in the secondary group, and the implantation rate (55.56%) and clinical pregnancy rate (68.42%) were both higher than those of the idiopathic group (28.75% and 40.00%) and KS group (22.05% and 30.77%). Micro-TESE surgery combined with ICSI insemination is the most effective treatment regimen for NOA patients. The SRR of NOA patients with different etiologies are related to certain specific factors, and micro-TESE surgery seems to be the ideal and only way to have biological children.

Identification of biomarkers associated with macrophage infiltration in non-obstructive azoospermia using single-cell transcriptomic and microarray data

Background

Non-obstructive azoospermia (NOA) is a common clinical cause of male infertility. Research suggests that macrophages are linked to testicular function; however, their involvement in NOA remains unknown.

Methods

To evaluate the importance of macrophages infiltration in NOA and identify the macrophage-related biomarkers, the gene-expression microarray data GSE45885 and the single-cell transcriptomic data GSE149512 were utilized from the Gene Expression Omnibus (GEO). A single-sample gene set enrichment analysis (ssGSEA) was conducted to investigate immune cell proliferation. The Seurat package was used for the single-cell data analysis, and the limma package was used to identify the differentially expressed genes between the NOA and normal samples. Moreover, we conducted a weighted gene co-expression network analysis (WGCNA) to identify the macrophage-related key modules and genes, and conducted Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) analyses for the functional exploration. To identify the macrophage-related biomarkers, we conducted least absolute shrinkage and selection operator (LASSO) and support vector machine-recursive feature elimination (SVM-RFE) analyses. Real-time quantitative polymerase chain reaction (RT-qPCR) was used to verify the marker genes present in NOA.

Results

We confirmed that open reading frame 72 gene on chromosome 9 (C9orf72) [area under the curve (AUC) =0.861] and cartilage-associated protein (CRTAP) (AUC =0.917) were the hub genes of NOA, and the RT-qPCR analysis revealed the critical expression of both genes in NOA.

Conclusions

Through the combination of tissue transcriptomic and single-cell RNA-sequencing analyses, we concluded that macrophage infiltration is significant in different subtypes of NOA, and we hypothesized that C9orf72 and CRTAP play critical roles in NOA due to their high expression in macrophages.

Down-Regulation of Neogenin Decreases Proliferation and Differentiation of Spermatogonia during the Early Phase of Spermatogenesis

Non-obstructive azoospermia is a major clinical issue associated with male infertility that remains to be addressed. Although neogenin is reportedly abundantly expressed in the testis, its role in mammalian spermatogenesis is unknown. We systematically investigated the role of neogenin during spermatogenesis by performing loss-of-function studies. Testis-specific neogenin conditional knock-out (cKO) mice were generated using CRISPR/Cas9 and neogenin-targeting guide RNAs. We analyzed the expression profiles of germ cell factors by RT-PCR and Western blotting. Neogenin localized mainly to spermatogonia in seminiferous tubules of mouse testes. RT-PCR and Western blot analyses further demonstrated that neogenin expression varied during spermatogenesis and was dramatically increased at postnatal day 12-25 during the pubertal stage. In neogenin-cKO mouse testes, the ratio of primary and secondary spermatocytes was significantly decreased compared with the control, while the number of apoptotic testicular cells was significantly increased. Taken together, these results suggest that neogenin plays a pivotal role in the maintenance and proliferation of spermatogonia during the early stage of spermatogenesis in mice.

Whole-genome sequencing identifies new candidate genes for nonobstructive azoospermia

BACKGROUND

Genetic causes that lead to spermatogenetic failure in patients with nonobstructive azoospermia (NOA) have not been yet completely established.

OBJECTIVE

To identify low-frequency NOA-associated single nucleotide variants (SNVs) using whole-genome sequencing (WGS).

MATERIALS AND METHODS

Men with various types of NOA (n = 39), including samples that had been previously tested with whole-exome sequencing (WES; n = 6) and did not result in diagnostic conclusions. Variants were annotated using the Ensembl Variant Effect Predictor, utilizing frequencies from GnomAD and other databases to provide clinically relevant information (ClinVar), conservation scores (phyloP), and effect predictions (i.e., MutationTaster). Structural protein modeling was also performed.

RESULTS

Using WGS, we revealed potential NOA-associated SNVs, such as: TKTL1, IGSF1, ZFPM2, VCX3A (novel disease causing variants), ESX1, TEX13A, TEX14, DNAH1, FANCM, QRICH2, FSIP2, USP9Y, PMFBP1, MEI1, PIWIL1, WDR66, ZFX, KCND1, KIAA1210, DHRSX, ZMYM3, FAM47C, FANCB, FAM50B (genes previously known to be associated with infertility) and ALG13, BEND2, BRWD3, DDX53, TAF4, FAM47B, FAM9B, FAM9C, MAGEB6, MAP3K15, RBMXL3, SSX3 and FMR1NB genes, which may be involved in spermatogenesis.

DISCUSSION AND CONCLUSION

In this study, we identified novel potential candidate NOA-associated genes in 29 individuals out of 39 azoospermic males. Note that in 5 out of 6 patients subjected previously to WES analysis, which did not disclose potentially causative variants, the WGS analysis was successful with NOA-associated gene findings.

The Fate of Leydig Cells in Men with Spermatogenic Failure

The steroidogenic cells in the testicle, Leydig cells, located in the interstitial compartment, play a vital role in male reproductive tract development, maintenance of proper spermatogenesis, and overall male reproductive function. Therefore, their dysfunction can lead to all sorts of testicular pathologies. Spermatogenesis failure, manifested as azoospermia, is often associated with defective Leydig cell activity. Spermatogenic failure is the most severe form of male infertility, caused by disorders of the testicular parenchyma or testicular hormone imbalance. This review covers current progress in knowledge on Leydig cells origin, structure, and function, and focuses on recent advances in understanding how Leydig cells contribute to the impairment of spermatogenesis.

Circulatory exosomal tRF-Glu-CTC-005 and tRF-Gly-GCC-002 serve as predictive factors of successful microdissection testicular sperm extraction in patients with nonobstructive azoospermia

OBJECTIVE

To identify circulating plasma exosomal transfer RNA-derived fragments (tRFs) as the predictive factors of successful microdissection testicular sperm extraction (micro-TESE) in patients with nonobstructive azoospermia (NOA).

DESIGN

Case and control prospective study.

SETTING

Academic research laboratory.

PATIENT(S)

Twelve patients with NOA with successful sperm retrieval by micro-TESE, 18 patients with NOA with failed sperm retrieval by micro-TESE, and 12 normozoospermic fertile controls.

INTERVENTION(S)

Blood samples were collected from participants.

MAIN OUTCOME MEASURE(S)

The abundance of tRFs normalized as counts per million of the total aligned reads with the next-generation sequencing system; candidate tRF levels were validated through quantitative reverse transcription polymerase chain reaction; predictive accuracy was evaluated by the receiver operating characteristic area under the curve analysis. The nomogram was built for ranking.

RESULT(S)

The plasma circulating exosomal tRF-Gly-GCC-002 and tRF-Glu-CTC-005 manifested the most confident differential expression between patients with NOA with successful sperm retrieval by micro-TESE and patients with NOA with failed sperm retrieval by micro-TESE. The target gene prediction of these 2 tRFs followed by the Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analysis indicated the functional enrichment of neuroendocrine protein metabolism and striatum/subpallium development. The herpes simplex virus 1 infection pathway was also involved. The receiver operating characteristic area under the curve (AUC) analysis demonstrated a promising predictive accuracy: tRF-Gly-GCC-002, AUC of 0.921, and tRF-Glu-CTC-005, AUC of 0.954. A regression model was built and presented with the nomogram for further assessment.

CONCLUSION(S)

This study described the exosomal tRF-Gly-GCC-002 and tRF-Glu-CTC-005 expression values, indicated a promising predictive effect for accessibility of sperm retrieval through micro-TESE from patients with NOA, and highlighted tRF-Gly-GCC-002 and tRF-Glu-CTC-005 as useful biomarkers in patients with NOA seeking in vitro conception with their residual sperm.

Semen analysis: a workflow for an appropriate assessment of the male fertility status

Infertility is a worldwide problem that affects 9-15% of couples of reproductive age. In about half of the cases, it recognizes, alone or in combination, a male cause. In addition to a reproductive problem, male infertility can result from a systemic disease. Consequently, semen analysis, a fundamental test in the diagnosis of male infertility, represents a useful indicator not only of a man's reproductive capacity but also of his health and lifestyle. Given the key role of semen analysis, only accredited laboratories should perform it and experienced clinicians should be called into play in its interpretation. In this article, we have extensively examined how the macroscopic and microscopic parameters of semen analysis, alone or associated with each other, allow clinicians to orient towards specific diagnoses that can be confirmed by further ad hoc tests. On this basis, we also proposed a diagnostic flowchart focused on the results of the semen analysis.

Technological Advancements in Male Infertility Microsurgery

There have been significant advancements in male infertility microsurgery over time, and there continues to be significant promise for new and emerging techniques, technologies, and methodologies. In this review, we discuss the history of male infertility and the evolution of microsurgery, the essential role of education and training in male infertility microsurgery, and new technologies in this space. We also review the potentially important role of artificial intelligence (AI) in male infertility and microsurgery.

A pathogenic DMC1 frameshift mutation causes nonobstructive azoospermia but not primary ovarian insufficiency in humans

Nonobstructive azoospermia (NOA) and diminished ovarian reserve (DOR) are two disorders that can lead to infertility in males and females. Genetic factors have been identified to contribute to NOA and DOR. However, the same genetic factor that can cause both NOA and DOR remains largely unknown. To explore the candidate pathogenic gene that causes both NOA and DOR, we conducted whole-exome sequencing (WES) in a non-consanguineous family with two daughters with DOR and a son with NOA. We detected one pathogenic frameshift variant (NM_007068:c.28delG, p. Glu10Asnfs*31) following a recessive inheritance mode in a meiosis gene DMC1 (DNA meiotic recombinase 1). Clinical analysis showed reduced antral follicle number in both daughters with DOR, but metaphase II oocytes could be retrieved from one of them. For the son with NOA, no spermatozoa were found after microsurgical testicular sperm extraction. A further homozygous Dmc1 knockout mice study demonstrated total failure of follicle development and spermatogenesis. These results revealed a discrepancy of DMC1 action between mice and humans. In humans, DMC1 is required for spermatogenesis but is dispensable for oogenesis, although the loss of function of this gene may lead to DOR. To our knowledge, this is the first report on the homozygous frameshift mutation as causative for both NOA and DOR and demonstrating that DMC1 is dispensable in human oogenesis.

Role of microRNAs in etiology of azoospermia and their application as non-invasive biomarkers in diagnosis of azoospermic patients

Azoospermia is a common cause of male infertility without any sperm in the semen and consists of ∼1% of all males and ∼15% of infertile ones. Currently, no accurate non-invasive diagnostic method exists for patients with azoospermia and testis biopsy is mandatory to determine if any spermatozoa exist in the testes. Studies have clarified that the expression of some distinct microRNAs shows alterations in azoospermic patients. MicroRNAs play critical roles during spermatogenesis and their dysregulation can defect this process. Here, we review studied microRNAs involved in the pathogenesis of azoospermia and their target genes. Moreover, we will imply the utility of seminal plasma microRNAs as non-invasive diagnostic biomarkers for azoospermia. We hope such studies could help patients with azoospermia in both diagnosis and treatment, in order that they could father their own biological children.

Germ Cell Derivation from Pluripotent Stem Cells for Understanding In Vitro Gametogenesis

Assisted reproductive technologies (ARTs) have developed considerably in recent years; however, they cannot rectify germ cell aplasia, such as non-obstructive azoospermia (NOA) and oocyte maturation failure syndrome. In vitro gametogenesis is a promising technology to overcome infertility, particularly germ cell aplasia. Early germ cells, such as primordial germ cells, can be relatively easily derived from pluripotent stem cells (PSCs); however, further progression to post-meiotic germ cells usually requires a gonadal niche and signals from gonadal somatic cells. Here, we review the recent advances in in vitro male and female germ cell derivation from PSCs and discuss how this technique is used to understand the biological mechanism of gamete development and gain insight into its application in infertility.

Visualization of Spatial Distribution of Spermatogenesis in Mouse Testes Using Creatine Chemical Exchange Saturation Transfer Imaging

BACKGROUND

When determining treatment strategies for male infertility, it is important to evaluate spermatogenesis and its spatial distribution in the testes.

PURPOSE

To investigate the usefulness of creatine chemical exchange saturation transfer (CrCEST) imaging for evaluating spermatogenesis and its spatial distribution.

STUDY TYPE

Prospective.

ANIMAL MODEL

C57BL/6 control mice (n = 5) and model mice of male infertility induced by whole testis X-ray irradiation (n = 11) or localized X-ray irradiation to lower regions of testes (n = 3).

FIELD STRENGTH/SEQUENCE

A 11.7-T vertical-bore magnetic resonance imaging (MRI)/segmented fast low-angle shot acquisition for CEST.

ASSESSMENT

The magnetization transfer ratio for the CrCEST effect (MTR_Cr* ) was calculated in each testis of the control mice and X-ray irradiation model mice at 10, 15, 20, and 30 days after irradiation. Correlation analysis was performed between MTR_Cr* and Johnsen's score, a histological score for spermatogenesis. In the localized X-ray irradiation model, regional MTR_Cr* and Johnsen's score were calculated for correlation analysis.

STATISTICAL TESTS

Unpaired t-test, one-way analysis of variance with Tukey's HSD test and Pearson's correlation analysis. A P value < 0.05 was considered statistically significant.

RESULTS

In the irradiation model, CrCEST imaging revealed a significant linear decrease of MTR_Cr* after irradiation (control, 8.7 ± 0.6; 10 days, 7.9 ± 0.8; 15 days, 6.5 ± 0.6; 20 days, 5.4 ± 1.0; 30 days, 4.4 ± 0.8). A significant linear correlation was found between MTR_Cr* and Johnsen's score (Pearson's correlation coefficient (r) = 0.79). In the localized irradiation model, CrCEST imaging visualized a significant regional decrease of MTR_Cr* in the unshielded region (shielded, 6.9 ± 0.7; unshielded, 4.9 ± 1.0), and a significant linear correlation was found between regional MTR_Cr* and Johnsen's score (r = 0.78).

DATA CONCLUSION

Testicular CrCEST effects correlated well with spermatogenesis. CrCEST imaging was useful for evaluating spermatogenesis and its spatial distribution.

EVIDENCE LEVEL

2 TECHNICAL EFFICACY: Stage 2.

A microfluidic approach to rapid sperm recovery from heterogeneous cell suspensions

The isolation of sperm cells from background cell populations and debris is an essential step in all assisted reproductive technologies. Conventional techniques for sperm recovery from testicular sperm extractions stagnate at the sample processing stage, where it can take several hours to identify viable sperm from a background of collateral cells such as white bloods cells (WBCs), red blood cells (RBCs), epithelial cells (ECs) and in some cases cancer cells. Manual identification of sperm from contaminating cells and debris is a tedious and time-consuming operation that can be suitably addressed through inertial microfluidics. Microfluidics has proven an effective technology for high-quality sperm selection based on motility. However, motility-based selection methods cannot cater for viable, non-motile sperm often present in testicular or epididymal sperm extractions and aspirations. This study demonstrates the use of a 3D printed inertial microfluidic device for the separation of sperm cells from a mixed suspension of WBCs, RBCs, ECs, and leukemic cancer cells. This technology presents a 36-fold time improvement for the recovery of sperm cells (> 96%) by separating sperm, RBCS, WBCs, ECs and cancer cells into tight bands in less than 5 min. Furthermore, microfluidic processing of sperm has no impact on sperm parameters; vitality, motility, morphology, or DNA fragmentation of sperm. Applying inertial microfluidics for non-motile sperm recovery can greatly improve the current processing procedure of testicular sperm extractions, simplifying the fertility outcomes for severe forms of male infertility that warrant the surgery.

Genetic counseling prior to assisted reproductive technology

BACKGROUND

Reproductive medicine deals with fertility and is closely related to heredity. In reproductive medicine, it is necessary to provide genetic information for the patients prior to assisted reproductive technology (ART). Japan Society for Reproductive Medicine (JSRM) requires doctors involved in reproductive medicine to have standard knowledge of reproductive genetics and knowledge of reproductive medicine, which is covered in their publication, "required knowledge of reproductive medicine."

METHODS

With the aim of providing straightforward explanations to patients in the clinical situation at pre-ART counseling, we provide the following five topics, such as (a) risk of birth defects in children born with ART, (b) chromosomal abnormalities, (c) Y chromosome microdeletions (YCMs), (d) possible chromosomal abnormal pregnancy in oligospermatozoa requiring ICSI (intracytoplasmic sperm injection), and (e) epigenetic alterations.

MAIN FINDINGS

The frequency of chromosome abnormalities in infertile patients is 0.595%-0.64%. YCMs are observed in 2%-10% of severe oligospermic men. High incidence of spermatozoa with chromosomal abnormalities has been reported in advanced oligospermia and asthenozoospermia that require ICSI. Some epigenetic alterations were reported in the children born with ART.

CONCLUSION

Certain genetic knowledge is important for professionals involved in reproductive medicine, even if they are not genetic experts.

Evaluating the quality of reported outcomes for microsurgical TESE in men with non-obstructive azoospermia: A methodological analysis

BACKGROUND

Publications of microsurgical testicular sperm extraction (mTESE) techniques and outcomes are heterogeneous, which may limit creation of best surgical practices.

OBJECTIVE

To study the quality and heterogeneity of published mTESE outcomes via a methodological analysis.

MATERIALS/METHODS

A systematic methodological analysis of all published literature on the use of mTESE in men with non-obstructive azoospermia from 1999 to the July 2020 was performed. PubMed and MEDLINE searches were performed using the search terms "microdissection TESE OR microsurgical TESE." Publications were evaluated on their reporting of pre-operative factors, intraoperative techniques, surgical and clinical outcomes, and adverse events.

RESULTS

Fifty-five studies met inclusion criteria. Surgical technique and sperm retrieval rates were the most reported criteria. Reporting on the presence of an embryologist intraoperatively was observed in approximately 30% of articles, while other procedural details including method of sperm quantification, quantity retrieved, and number of cryopreserved vials were observed in fewer than 10% of articles. Clinical outcomes, including pregnancy rates and live birth rates, were reported in fewer than 40% of the articles. Fetal outcomes including fetal and neonatal anomalies were rarely reported. Fetal growth restriction, preterm delivery, small or large for gestational age, and NICU admissions were never reported.

CONCLUSION

There are inconsistencies in reporting quality of mTESE outcomes, specifically a lack of information on the quantity and quality of sperm retrieved, the role of embryology intraoperatively, and clinical outcomes, such as live birth rate and fetal anomalies. These gaps may guide development of standardized reporting guidelines to better assess and compare clinical outcomes across institutions and maintain focus on couples-centric fertility outcomes in future mTESE studies.

The impact of fresh and frozen testicular tissue quality on embryological and clinical outcomes

Our ability to predict the potential of testicular spermatozoa to support embryonic development is still limited. Although motility of testicular spermatozoa is associated with embryo development, the impact of morphology and the presence of spermatozoa in the testicular sample has not been previously researched. Moreover, while the majority of data indicate no effect of cryopreservation, there are studies reporting impaired clinical outcomes due to testicular cryopreservation. In a retrospective study, 118 ICSI-TESE cycles were analysed to study the impact of (a) total quality of testicular tissue, (b) testicular tissue cryopreservation and (c) presence/motility/morphology of testicular spermatozoa in fertilisation rate, embryonic development, clinical pregnancy (CPR), ongoing pregnancy (OPR) and live birth rate (LBR). Results showed that fertilisation rate was significantly affected by both total quality of testicular tissue (p < .05) and rare presence of spermatozoa (p < .01). Moreover, total tissue quality (p < .01), cryopreservation of low-quality samples (p < .01), absence of motile testicular spermatozoa (p < .01) and poor spermatozoa morphology (p < .05) had a negative impact on the number of good quality day 3 embryos. CPR, OPR or LBR was not affected by any parameters examined. Our data suggest that the quality of testicular tissue influences both fertilisation rate and embryo development. Moreover, cryopreservation of low-quality testicular samples has a negative impact on the number of available embryos for transfer.

Y-Chromosome Microdeletions: A Review of Prevalence, Screening, and Clinical Considerations

Deletions within the male-specific region of the Y-chromosome, known as Y-Chromosome Microdeletions (YCMs), are present in as many as 5% and 10% of severe oligospermic and azoospermic men, respectively. These microdeletions are distinguished by which segment of the Y chromosome is absent, identified as AZFa (the most proximal segment), AZFb (middle), and AZFc (distal). The reported prevalence of YCMs within the world’s populations of infertile men displays vast heterogeneity, ranging from less than 2% to over 24% based on region and ethnicity. AZFc is the most commonly identified YCM, and its phenotypic presentation provides for the highest chance for fertility through artificial reproductive techniques. Conversely, deletions identified in the subregions of AZFa, AZFb, or any combination of regions containing these segments, are associated with low probabilities of achieving pregnancy. A putative mechanism explaining this discrepancy lies within the expression of autosomal, DAZ-like genes which could serve to “rescue” wild type AZFc gene expression and hence spermatogenesis. Nevertheless, recent reports challenge this dogma and stress the importance of further analysis when an AZFb deletion is detected. The screening thresholds to determine which oligospermic and azoospermic men are tested for potential YCMs has been recently contested. More recent literature supports lowering the threshold from 5 million sperm/mL of ejaculate to 1 million/mL as the frequency of YCMs in men with sperm concentrations between 1 and 5 million sperm/mL is very low (~0.8%). As such, subsequent guidelines should recommend a lower screening threshold. While YCMs are extremely common globally, the understanding of their clinical significance in the field remains scattered and without consensus. Furthermore, very little is currently known about partial deletions within the AZFc region, such as b1/b3, b2/b3, and gr/gr. Hence, this review aimed to summarize and discuss modern trends in the epidemiology, screening guidelines, and clinical considerations pertaining to YCMs.

A novel homozygous mutation in the meiotic gene MSH4 leading to male infertility due to non-obstructive azoospermia

Non-obstructive azoospermia (NOA) is the most severe form of male infertility. Although some causes have been established, including genetic causes, the etiology in most cases remains idiopathic. Mutations in MSH4 (OMIM: 602105), an important gene involved in meiosis, may be related to female infertility due to primary ovarian insufficiency (POI) and male NOA. Here, we report a novel homozygous stop-gain mutation of MSH4 associated with NOA. Whole exome sequencing (WES) and bioinformatic analysis were performed in a patient with NOA from a consanguineous family (F1 II-1). A rare homozygous MSH4 stop-gain mutation (c.1552C>T:p.Q518X) was observed in the patient, and his parents were heterozygous carriers, as verified by Sanger sequencing. Testicular biopsy and hematoxylin and eosin staining of testicular tissue suggested meiotic arrest (MA), and no sperm were observed. MSH4 was detected in other 50 separate cases with same pathological results of MA using the same procedures, but only one heterozygous mutation was observed. Subsequent real-time quantitative polymerase chain reaction and immunohistochemistry were performed to examine mRNA expression levels and the localization of the MSH4 protein in the testicular tissue. Furthermore, the expression of MSH4 mRNA was significantly decreased compared with normal control. MSH4 protein was highly expressed in spermatocytes in the seminiferous tubules of the normal control, while no obvious expression was observed in F1 II-1. In this present study, MSH4 was identified as a candidate gene of male infertility causing NOA. A novel mutation of MSH4 (c.1552C>T:p.Q518X) is associated with the MA phenotype during spermatogenesis.

The benefits of varicocele repair for achieving pregnancy in male infertility: A systematic review and meta-analysis

Introduction

Varicocele is one of the most common treatable causes of male infertility. However, the decision to perform varicocelectomy before starting a fertility program remains controversial. This study aimed to thoroughly review and analyze the benefit of varicocele repair and its impact on the success rate of a fertility program.

Materials and methods

A systematic literature search was performed using MEDLINE, Cochrane Library, and Wiley Library. The primary outcome was the pregnancy rate, and the secondary outcomes were live birth rate and surgical sperm retrieval success rate. Outcomes were compared between men who underwent treatment for a varicocele and those that did not. The pooled analysis data are presented as odds ratios with 95% confidence intervals.

Results

A total of 31 articles were included in the meta-analysis. The pregnancy rate was significantly higher in the treated group (odds ratio = 1.82; 95% confidence interval: 1.37-2.41; P < 0.0001) along with the live birth rate (odds ratio = 2.80; 95% confidence interval: 1.67-4.72; P = 0.0001). The further subgroup analysis revealed a higher pregnancy rate in treated men with azoospermia, subnormal semen parameters, and normozoospermia (P = 0.04, P = 0.0005, and P = 0.002, respectively), while the live birth rate was only significantly higher in the treated men with subnormal semen parameters and normozoospermia (P = 0.001 and P < 0.0001). Treated varicocele also led to a higher sperm retrieval rate in azoospermic patients (odds ratio = 1.69; 95% confidence interval: 1.16-2.45; P = 0.006).

Conclusions

Varicocele repair increased the pregnancy and live birth rates regardless the semen analysis result, along with the sperm retrieval success rate in azoospermic men. Thus, varicocele repair may be beneficial prior to joining a fertility program.

Complex Y chromosome anomalies in an infertile male

Y chromosome anomalies are closely associated with non-obstructive azoospermia (NOA), a major etiology in male infertility. Klinefelter syndrome (KS) and Y chromosome microdeletions are some of the well-identified genetic defects in this regard, while Y chromosome aneuploidies have been reported to be susceptive. We report the rare case of a patient presenting with three complex genetic defects: mosaic Y chromosome aneuploidy; loss of the heterochromatin region in the q arm of the Y chromosome (Yqh-); and azoospermia factor C subregion (AZFc) microdeletion. The patient reported he had been subfertile for five years. Semen analysis confirmed total azoospermia along with an unaffected hormonal profile for serum follicle stimulating hormone (FSH), luteinizing hormone (LH), and prolactin levels. Since the microdeletion analysis of azoospermia factor (AZF) region revealed the presence of three microdeletions in the AZFc region, the patient was offered intracytoplasmic sperm injection (ICSI) upon the retrieval of sperm by testicular sperm extraction (TESE) as the best possible assisted reproductive treatment (ART) option. It was further suggested to carry out pre-implantation genetic screening (PGS) in order to facilitate the transfer of only female embryos, thus preventing the dissemination of Y chromosomal anomalies.

Applying Single-Cell Analysis to Gonadogenesis and DSDs (Disorders/Differences of Sex Development)

The gonads are unique among the body's organs in having a developmental choice: testis or ovary formation. Gonadal sex differentiation involves common progenitor cells that form either Sertoli and Leydig cells in the testis or granulosa and thecal cells in the ovary. Single-cell analysis is now shedding new light on how these cell lineages are specified and how they interact with the germline. Such studies are also providing new information on gonadal maturation, ageing and the somatic-germ cell niche. Furthermore, they have the potential to improve our understanding and diagnosis of Disorders/Differences of Sex Development (DSDs). DSDs occur when chromosomal, gonadal or anatomical sex are atypical. Despite major advances in recent years, most cases of DSD still cannot be explained at the molecular level. This presents a major pediatric concern. The emergence of single-cell genomics and transcriptomics now presents a novel avenue for DSD analysis, for both diagnosis and for understanding the molecular genetic etiology. Such -omics datasets have the potential to enhance our understanding of the cellular origins and pathogenesis of DSDs, as well as infertility and gonadal diseases such as cancer.

Does varicocelectomy improve semen in men with azoospermia and clinically palpable varicocele?

The effectiveness of varicocelectomy in nonobstructive azoospermia is controversial. The current study assessed the efficacy of microsurgical subinguinal varicocelectomy in nonobstructive azoospermic men with palpable varicocele and to evaluate predictive parameters of outcome. We reviewed the records of 723 patients who had microsurgical varicocelectomy and diagnostic testicular biopsy between 2012 and 2016 at a tertiary medical centre. Data pertaining to the physical, laboratory (semen analysis and hormonal profile) and histopathology features were examined, exploring the predictors of improvement in semen analysis post-varicocelectomy. In total, 42 patients with mean age 35.71 ± 6.35 years were included. After a mean varicocelectomy follow-up of 6.7 months, motile spermatozoa in the ejaculate could be observed in 11 patients (26.2). Out of all the factors examined, only testicular histopathology significantly predicted post-varicocelectomy outcome, where 8/11 patients exhibited hypospermatogenesis, and 3/11 Sertoli cell-only regained spermatozoa in semen. Microsurgical varicocelectomy in nonobstructive azoospermic men with clinically palpable varicocele can result in sperm appearance in the ejaculate with the highest success expected in hypospermatogenesis.

Effects of medical comorbidity on male infertility and comorbidity treatment on spermatogenesis

OBJECTIVE

To investigate the prevalence and effects of medical comorbidities on spermatogenesis and to determine whether the treatment of medical comorbidities effectively improves spermatogenesis.

DESIGN

Single-center case-control study.

SETTING

University hospital.

PATIENT(S)

A total of 3,328 infertile men and 452 men with normal results on semen examination, with mean age of 35 years.

INTERVENTION(S)

Hormonal and spermatogenic parameters were compared between the men with and without medical comorbidities. For the men diagnosed with medical comorbidities during the infertility evaluation, semen parameters were compared between those who did and did not undergo treatment of the comorbidities.

MAIN OUTCOME MEASURE(S)

Rate of comorbidity, relationship between infertility and comorbidity, comorbidity treatment on total motile sperm count.

RESULT(S)

The prevalence of comorbidities was significantly higher in the infertile men (21.7%) than in the fertile men (9.1%), particularly for hypertension (17.8%), hyperlipidemia (5.9%), hyperuricemia (5.2%), and skin disease (3.0%). Among the infertile men, the reproductive functions were aberrant in the men with comorbidity compared with those without comorbidity. After treatment for comorbidities, a significant increase was observed in the total motile sperm count compared with both the baseline values and with the poorly controlled men. A multivariate analysis showed that varicocele and comorbidity treatments were independent predictors of an improved total motile sperm count, with odds ratios of 2.895 and 2.057, respectively.

CONCLUSION(S)

Medical comorbidities are associated with impaired sperm production. Male infertility evaluation offers not only specific therapy to improve semen parameters but also therapy for nonspecific medical comorbidities, which may benefit general health status and spermatogenesis restoration.