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

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

Current Updates on Involvement of Artificial Intelligence and Machine Learning in Semen Analysis.

Background and Objectives: Infertility rates and the number of couples undergoing reproductive care have both increased substantially during the last few decades. Semen analysis is a crucial step in both the diagnosis and the treatment of male infertility. The accuracy of semen analysis results remains quite poor despite years of practice and advancements. Artificial intelligence (AI) algorithms, which can analyze and synthesize large amounts of data, can address the unique challenges involved in semen analysis due to the high objectivity of current methodologies. This review addresses recent AI advancements in semen analysis. Materials and Methods: A systematic literature search was performed in the PubMed database. Non-English articles and studies not related to humans were excluded. We extracted data related to AI algorithms or models used to evaluate semen parameters from the original studies, excluding abstracts, case reports, and meeting reports. Results: Of the 306 articles identified, 225 articles were rejected in the preliminary screening. The evaluation of the full texts of the remaining 81 publications resulted in the exclusion of another 48 articles, with a final inclusion of 33 original articles in this review. Conclusions: AI and machine learning are becoming increasingly popular in biomedical applications. The examination and selection of sperm by andrologists and embryologists may benefit greatly from using these algorithms. Furthermore, when bigger and more reliable datasets become accessible for training, these algorithms may improve over time.

Clomiphene Citrate in the Management of Infertility in Oligospermic Obese Men with Hypogonadism: Retrospective Pilot Study.

Background and Objectives: Obesity is a significant risk factor for hypogonadism and infertility that is further associated with reduced semen quality. The aim of this study is to evaluate the effect of clomiphene citrate (CC), prescribed for treating infertility, on serum testosterone and semen parameters, particularly in oligospermic obese hypogonadal men. Materials and Methods: A retrospective analysis of data related to men (n = 53) who underwent CC treatment for infertility and hypogonadism (testosterone < 300 ng/dL) was performed. Patients with obesity (BMI ≥ 30 kg/m2) and sperm concentration ≤ 15 × 106/mL were included for analysis. Results: The overall results showed that, in oligospermic obese men (n = 31), treatment with CC significantly improved baseline sperm concentration (4.5 ± 6.8 × 106/mL vs. 11.4 ± 15.5 × 106/mL, p < 0.05) and motility (31.5% ± 21.5% vs. 42.6% ± 14.7%, p < 0.05). Furthermore, subsequent examination of oligospermic hypogonadal obese men treated with CC (n = 13) revealed substantial improvements in baseline serum testosterone levels (193.8 ± 59.3 ng/dL vs. 332.7 ± 114.8 ng/dL, p < 0.05) along with an increase in sperm concentration, total motility, and normal morphology. Conclusions: The results of this retrospective study suggest that CC treatment not only improves chances of fertility outcomes by substantially improving semen parameters but also increases total serum testosterone levels in oligospermic obese men without any supplemental and expensive testosterone replacement therapy.

Male infertility.

It is estimated that infertility affects 8-12% of couples globally, with a male factor being a primary or contributing cause in approximately 50% of couples. Causes of male subfertility vary highly, but can be related to congenital, acquired, or idiopathic factors that impair spermatogenesis. Many health conditions can affect male fertility, which underscores the need for a thorough evaluation of patients to identify treatable or reversible lifestyle factors or medical conditions. Although semen analysis remains the cornerstone for evaluating male infertility, advanced diagnostic tests to investigate sperm quality and function have been developed to improve diagnosis and management. The use of assisted reproductive techniques has also substantially improved the ability of couples with infertility to have biological children. This Seminar aims to provide a comprehensive overview of the assessment and management of men with infertility, along with current controversies and future endeavours.

Molecular Interactions Associated with Oxidative Stress-Mediated Male Infertility: Sperm and Seminal Plasma Proteomics.

Male factor issues are responsible for 50% of couples infertility. Seminal oxidative stress is one of the major factors that affect the normal physiological aspects of sperm function such as motility and progression, hyperactivation, capacitation, acrosome reaction and zona-pellucida penetration prior to fertilization. In recent times, high-throughput proteomic platforms are used to identify the proteins associated with these aspects of sperm function as associated with oxidative stress. In this review, we have provided a workflow that includes an overview of advanced proteomic techniques and bioinformatic tools used to interpret proteomic results. Furthermore, we have highlighted proteins associated with dysregulated molecular pathways in sperm and seminal plasma due to oxidative stress. We have also described the molecular interactions between proteins associated with oxidative stress and their potential role in male infertility.

Eurycoma longifolia (Jack) Improves Serum Total Testosterone in Men: A Systematic Review and Meta-Analysis of Clinical Trials.

Background and Objectives: Male hypogonadism is a clinical disorder characterized by reduced serum testosterone in men. Although treatment using herbal medicines, including Eurycoma longifolia, has been investigated, the benefits remain unclear. This study aims to investigate the efficacy of E. longifolia as a sole intervention to increase testosterone levels in males. Materials and Methods: We conducted a systematic review and meta-analysis of randomized clinical trials (RCTs) according to the PRISMA guidelines. Relevant articles were retrieved from the databases PubMed, Scopus, Web of Science, Cochrane, Ovid/Embase, and Google Scholar. Results: After literature screening, a total of nine studies was included in the systematic review. Five RCTs were included in the meta-analysis. A significant improvement in total testosterone levels after E. longifolia treatment was mostly reported in both healthy volunteers and hypogonadal men. The random model effect revealed a significant increase (SMD = 1.352, 95% CI 0.565 to 2.138, p = 0.001) in the total testosterone levels in men receiving E. longifolia supplementation, which was confirmed in the hypogonadism subgroup. Conclusions: This systematic review and meta-analysis of the literature supports the possible use of E. longifolia supplementation for enhancing testosterone production. Although more research is required before its use in clinical practice, this may represent a safe and promising therapeutic option, particularly in hypogonadal men.

Protein profiling in unlocking the basis of varicocele-associated infertility.

Varicocele is one of the major causes of male infertility and has a negative impact on spermatogenesis. The conventional semen analysis does not reveal the underlying subcellular mechanisms associated with defects in spermatozoa. Proteomics and bioinformatics analysis can be used to identify the molecular aetiologies associated with poor semen quality in varicocele patients. Mitochondrial dysfunction has been identified as the main factor affecting normal physiological functions of spermatozoa. This article discusses the proteomic studies of spermatozoa and seminal plasma in varicocele patients. Proteomics can identify potential spermatozoa and seminal plasma biomarkers in varicocele-mediated male infertility. In future, these protein biomarkers can be useful in the development of noninvasive diagnostic and therapeutic strategies for varicocele patients.

Etiologies of sperm DNA damage and its impact on male infertility.

Male factor is responsible for up to 50% of infertility cases in the world. Semen analysis is considered the cornerstone of laboratory evaluation of male infertility, but it has its own drawbacks and fails to predict the male fertility potential with high sensitivity and specificity. Different etiologies have been linked with male infertility, of which sperm DNA damage has gained significant attention with extensive research on sperm function tests. The associations between sperm DNA damage and a variety of disorders such as varicocele, obesity, cancer, radiation and lifestyle factors are explored in this review. Furthermore, we discuss the mechanisms of DNA damage as well as its impact in different scenarios of male infertility, associated with spontaneous and assisted reproduction. Finally, we review the clinical applicability of sperm DNA fragmentation testing in the management of male infertility.

Evaluation of seminal oxidation-reduction potential in male infertility.

The role of oxidative stress in male infertility has been broadly recognised, and the search for a new marker to determine the redox environment in semen has gained considerable interest. Oxidation-reduction potential (ORP) or redox potential, is a measure of the electron transfer from antioxidants to oxidants and provides information on the redox balance. In this review, the benefits of ORP as a new oxidative stress marker, the protocol for its evaluation and the importance of its measurement in the context of male infertility are discussed. In association with the standard semen analysis, seminal ORP has been analysed to evaluate semen quality and male fertility status. However, further studies are required to establish its use in assisted reproductive techniques (ART) practice.

Proteomics and metabolomics - Current and future perspectives in clinical andrology.

Proteomics and metabolomics are emerging as promising tools to investigate the molecular mechanisms associated with male infertility. Proteins and metabolites play a pivotal role in regulating the molecular pathways associated with physiological functions of spermatozoa. Semen analysis, physical examination and laboratory work up cannot identify the etiology of infertility in 30%-40% of cases, which are classified as idiopathic. Therefore, the application of proteomics and metabolomics in the field of andrology will aid to overcome the limitations of the standard semen analysis. Understanding the molecular pathways associated with male infertility will help in planning ad hoc treatments, contributing to the clinical management of infertile patients. In this review, proteomics and metabolomics studies on spermatozoa and seminal plasma are discussed with a focus on molecular biomarkers associated with male infertility-related conditions.

A scientometric analysis of research publications on male infertility and assisted reproductive technology.

Assisted reproductive technologies (ART) are considered as one of the primary management options to address severe male factor infertility. The purpose of this study was to identify the research trends in the field of male infertility and ART over the past 20 years (2000-2019) by analysing scientometric data (the number of publications per year, authors, author affiliations, journals, countries, type of documents, subject area and number of citations) retrieved using the Scopus database. We used VOS viewer software to generate a network map on international collaborations as well as a heat map of the top scientists in this field. Our results revealed a total of 2,148 publications during this period with Cleveland Clinic Foundation contributing the most (n = 69). The current scientometric analysis showed that the research trend on ART has been stable over the past two decades. Further in-depth analysis revealed that density gradient centrifugation (46%) and intracytoplasmic sperm injection (59.2%) are the most reported techniques for sperm separation and ART, respectively. Additionally, azoospermia was the most studied clinical scenario (60.6%), with majority of articles reporting pregnancy rate (47.25%) as the primary reproductive outcome for ART. This study provides insight into the current focus of research in the area of male infertility and ART as well as the areas that require further research in future.

An online educational model in andrology for student training in the art of scientific writing in the COVID-19 pandemic.

In 2020, the COVID-19 pandemic led to the suspension of the annual Summer Internship at the American Center for Reproductive Medicine (ACRM). To transit it into an online format, an inaugural 6-week 2020 ACRM Online Mentorship Program was developed focusing on five core pillars of andrology research: scientific writing, scientific methodology, plagiarism understanding, soft skills development and mentee basic andrology knowledge. This study aims to determine mentee developmental outcomes based on student surveys and discuss these within the context of the relevant teaching and learning methodology. The mentorship was structured around scientific writing projects established by the team using a student-centred approach, with one-on-one expert mentorship through weekly formative assessments. Furthermore, weekly online meetings were conducted, including expert lectures, formative assessments and social engagement. Data were collected through final assessments and mentee surveys on mentorship outcomes. Results show that mentees (n = 28) reported a significant (p < .0001) improvement in all criteria related to the five core pillars. These results illustrate that the aims of the online mentorship program were achieved through a unique and adaptive online educational model and that our model has demonstrated its effectiveness as an innovative structured educational experience through the COVID-19 crisis.

Dysregulation of Key Proteins Associated with Sperm Motility and Fertility Potential in Cancer Patients.

Cancer has adverse effects on male reproductive health. Conventional semen analysis does not explain the molecular changes in the spermatozoa of cancer patients. Currently, proteomics is being widely used to identify the fertility-associated molecular pathways affected in spermatozoa. The objective of this study was to evaluate the sperm proteome of patients with various types of cancer. Cryopreserved semen samples from patients (testicular cancer, n = 40; Hodgkin's disease, n = 32; lymphoma, n = 20; leukemia, n = 17) before starting therapy were used for proteomic analysis, while samples from fertile donors (n = 19) were included as controls. The proteomic profiling of sperm was carried out by liquid chromatography-tandem mass spectrometry, and differentially expressed proteins involved in the reproductive processes were validated by Western blotting. Bioinformatic analysis revealed that proteins associated with mitochondrial dysfunction, oxidative phosphorylation, and Sirtuin signaling pathways were dysregulated in cancer patients, while oxidative phosphorylation and tricarboxylic acid cycle were predicted to be deactivated. Furthermore, the analysis revealed dysregulation of key proteins associated with sperm fertility potential and motility (NADH:Ubiquinone oxidoreductase core subunit S1, superoxide dismutase 1, SERPINA5, and cytochrome b-c1 complex subunit 2) in the cancer group, which were further validated by Western blot. Dysfunctional molecular mechanisms essential for fertility in cancer patients prior to therapy highlight the potential impact of cancer phenotype on male fertility.

Functional Analysis of Differentially Expressed Acetylated Spermatozoal Proteins in Infertile Men with Unilateral and Bilateral Varicocele.

Sperm proteins undergo post-translational modifications, such as phosphorylation, acetylation, and ubiquitination, which in turn play a key role in determining their fertilizing ability. In the current study, we examined the sperm proteome of men with unilateral and bilateral varicocele to identify the key proteins affected by acetylation to gain an insight into the difference in the severity of affected sperm function in the latter. An LTQ-Orbitrap Elite hybrid mass spectrometer system was used to profile the sperm proteome in pooled unilateral and bilateral varicocele patients. Bioinformatics database and tools, such as UniProtKB, Ingenuity Pathway Analysis Software (IPA) and Metacore, were used to identify the differentially expressed proteins (DEPs) involved in the acetylation process. A total of 135 DEPs in the spermatozoa of unilateral and bilateral varicocele patients were found to be affected by acetylation. The majority of these DEPs found were regulated by key transcription factors such as androgen receptor, p53, and NRF2. Furthermore, the DEPs predicted to be affected by the acetylation process were associated with fertilization, acrosome reaction, mitochondrial dysfunction and oxidative stress. Aberrant expression of proteins and their differential acetylation process may affect the normal physiological functions of spermatozoa. Protein-protein interactions identified dysregulation of the proteasome complex in the bilateral varicocele group. Damage to the proteasome complex may result in aggregation of the misfolded proteins, which in turn increase sperm DNA damage and apoptosis in patients with bilateral varicocele.

Proteomic Analyses of Human Sperm Cells: Understanding the Role of Proteins and Molecular Pathways Affecting Male Reproductive Health.

Human sperm proteomics research has gained increasing attention lately, which provides complete information about the functional state of the spermatozoa. Changes in the sperm proteome are evident in several male infertility associated conditions. Global proteomic tools, such as liquid chromatography tandem mass spectrometry and matrix-assisted laser desorption/ionization time-of-flight, are used to profile the sperm proteins to identify the molecular pathways that are defective in infertile men. This review discusses the use of proteomic techniques to analyze the spermatozoa proteome. It also highlights the general steps involved in global proteomic approaches including bioinformatic analysis of the sperm proteomic data. Also, we have presented the findings of major proteomic studies and possible biomarkers in the diagnosis and therapeutics of male infertility. Extensive research on sperm proteome will help in understanding the role of fertility associated sperm proteins. Validation of the sperm proteins as biomarkers in different male infertility conditions may aid the physician in better clinical management.

Distinct Proteomic Profile of Spermatozoa from Men with Seminomatous and Non-Seminomatous Testicular Germ Cell Tumors.

Testicular germ cell tumors (TGCTs) are predominant in young males (15-44 years). Seminomatous and non-seminomatous TGCTs account for about 98% of all TGCTs cases. In this study, we aimed to compare the sperm proteome of patients with seminomatous and non-seminomatous TGCTs to identify possible protein biomarkers that could help distinguish between them in a non-invasive manner. We analyzed semen samples from patients with seminomatous or non-seminomatous TGCTs (n = 15/group) that were cryopreserved before the start of cancer treatment. Quantitative proteomic analysis was conducted on pooled samples (n = 3/group) and a total of 258 differentially expressed proteins (DEPs) were identified. The overexpression of acrosin precursor (ACR) and chaperonin containing TCP1 subunit 6B (CCT6B) as well as the underexpression of S100 calcium-binding protein A9 (S100A9) in the spermatozoa of patients with non-seminomatous TGCTs were validated by western blotting conducted on individual samples (n = 6 for seminomatous group and n = 6 for non-seminomatous group). Our overall results suggest an association between the higher and faster invasiveness of non-seminomatous TGCTs and the altered protein expressions, providing important information for future studies.

Molecular Pathways Associated with Sperm Biofunction Are Not Affected by the Presence of Round Cell and Leukocyte Proteins in Human Sperm Proteome.

In human sperm proteomic experiments, leukocyte and round cell proteins may contaminate the sperm proteome and affect the bioinformatic results. The main objective of this study was to identify the possible interference of these proteins, especially from leukocytes, in identification of sperm functional pathways through proteomic and bioinformatic tools. We have evaluated the sperm proteome by liquid chromatography-tandem mass spectrometry (LC-MS/MS) in four groups: (1) neat semen with round cells and leukocytes ≥1 × 106/mL; (2) samples with round cells and leukocytes ≥1 × 106/mL processed by 65% density gradient centrifugation; (3) neat semen with round cells <1 × 106/mL; and (4) samples with round cells <1 × 106/mL processed by 65% density gradient centrifugation. Pure leukocyte culture was used as a control group. The difference in the conserved DEPs (common to both sperm and leukocytes) between the sperm samples with leukocytes ≥1 × 106/mL and round cells <1 × 106/mL was negligible. Comparative analysis between groups 1, 2, 3, and 4 with the control group revealed that the presence of leukocyte proteins does not significantly alter the activation z-score of the identified canonical pathways or biological functions in sperm proteome. Our experimental results demonstrate that the presence of round cell and leukocyte proteins do not affect the identification of the molecular pathways associated with human spermatozoa protein function. Hence, the use of neat frozen semen samples for proteomic studies showed no significant impact on the downstream bioinformatic analysis.

Tracking research trends and hotspots in sperm DNA fragmentation testing for the evaluation of male infertility: a scientometric analysis.

BACKGROUND: This article describes the research trends in sperm DNA fragmentation (SDF) over the past 20 years (1999-2018) using a scientometric approach. METHODS: A stepwise approach was adopted to retrieve scientometric data (articles per year, authors, affiliations, journals, countries) from Scopus and analyze the publication pattern of SDF with reference to key areas of research in the field of Andrology. RESULTS: A total of 2121 articles were retrieved related to SDF. Our data revealed an increasing research trend in SDF (n = 33 to n = 173) over the past 20 years (R2 = 0.894). Most productive country in publications was the USA (n = 450), while Agarwal A. (n = 129) being the most productive author. Most of the articles in SDF were primarily focused on lifestyle (n = 157), asthenozoospermia (n = 135) and varicocele (130). Mechanistic studies on SDF were published twice as much as prognostic/diagnostic studies, with significant emphasis on oxidative stress. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) was the most widely used technique to evaluate SDF. Publications on SDF related to assisted reproductive techniques also showed a linear increasing trend (R2 = 0.933). CONCLUSIONS: Our analysis revealed an increasing trend in SDF publications predominantly investigating lifestyle, asthenozoospermia and varicocele conditions with TUNEL being the most widely used technique. A substantial increase in research is warranted to establish SDF as prognostic/diagnostic parameter to evaluate clinical scenarios and ART outcomes.

Is there plagiarism in the most influential publications in the field of andrology?

Plagiarism is a common form of academic misconduct that extensively jeopardises the quality of scientific publication. The purpose of this study is to determine the extent of plagiarism in the most influential andrology articles. A total of 77 highly cited andrology articles were analysed for their similarity index using iThenticate and Turnitin. The articles were categorised based on the year (before and on/after 2000) and type of publication (review and research articles), and the similarity indices were compared. Furthermore, the analysed articles were categorised based on the level of similarity using an arbitrary similarity index range (low: ≤10, moderate: 11-20, high: 21-50 and very high: >50) and average incidence rate (%) was determined. Our analysis revealed a higher percentage of the similarity indices for reviews than research articles. We noticed a higher similarity index for articles published on/after 2000 than those published before. The majority of the influential articles in the field of andrology showed a low similarity index, while some articles exhibited moderate to high levels of similarity. These findings support the need for the development of similarity index guidelines as a major pre-requisite for establishing a more transparent and efficient system to address plagiarism in scientific publications.

Round cells do not contaminate or mask human sperm proteome in proteomic studies using cryopreserved samples.

Semen contains leucocytes and round cells, besides spermatozoa. The objective of this study was to identify whether the proteins from round cells and leucocytes affect the proteomic analysis of spermatozoa. Cryopreserved human sperm samples were divided into four groups: (1) samples with ≥1 × 106 /ml leucocytes unprocessed; (2) samples with ≥1 × 106 /ml leucocytes processed by 65% density centrifugation; (3) samples with round cells <1 × 106 /ml unprocessed; and (4) samples with round cells <1 × 106 /ml processed by 65% density centrifugation. Samples from each group (1, 2, 3 and 4) were pooled (n = 5) for quantitative proteomic analysis using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Comparative analysis revealed nine differentially expressed proteins (DEPs) groups 1 and 2. Moreover, five DEPs were identified between groups 3 and 4. We observed that cylicin-1, Atlastin-1 and vesicle transport protein SFT2B are specific to spermatozoa, and none of them were associated with leucocytes. The number of DEPs in spermatozoa of processed and unprocessed cryopreserved semen samples was negligible. Our results indicate that the presence of round cells (<1 × 106 /ml) in the seminal ejaculation does not interfere in the accurate detection of spermatozoa proteome by LC-MS/MS.