Browsing by Author "Henkel, R"

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    Association among sperm chromatin condensation, sperm DNA fragmentation and 8-OHdG in seminal plasma and semen parameters in infertile men with oligoasthenoteratozoospermia
    (Wiley, 2021) Hologlu, D; Gunes, S; Henkel, R
    The present study aimed to investigate the clinical role of standard sperm diagnosis parameters (sperm concentration, motility, morphology) as well as aniline blue staining of histones, 8-OHdG, TUNEL assay were performed on semen samples in infertile men with oligoasthenoteratozoospermia (OAT). Thirty-two infertile and ten proven fertile men were included in the study. Chromatin condensation sperm in infertile men was significantly lower compared to the fertile men (p < 0.0001). Age, sperm concentration, morphology and motility were significantly negatively correlated with chromatin condensation (p < 0.05). However, no significant correlations among the chromatin condensation, SDF and sperm DNA damage were detected in terms of 8- OHdG concentration.
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    Association of XRCC1 and ERCC2 promoters’ methylation with chromatin condensation and sperm DNA fragmentation in idiopathic oligoasthenoteratozoospermic men
    (Blackwell Publishing Ltd, 2021) Henkel, R; Metin Mahmutoglu, A; Gunes, S
    The aim of the study was to investigate whether the promoter methylation of XRCC1 and ERCC2 genes is associated with sperm DNA fragmentation and chromatin condensation in idiopathic oligoasthenoteratozoospermic men. This study involved 77 infertile men with idiopathic oligoasthenoteratozoospermia and 51 normozoospermic controls. The methylight method, TUNEL assay and aniline blue staining were used for the evaluation of XRCC1 and ERCC2 genes’ methylation, SDF and sperm chromatin condensation, respectively. SDF (p =.004) and XRCC1 methylation (p =.0056) were found to be significantly higher in men with idiopathic OAT than in the controls, while mature spermatozoa frequency was higher in controls as compared to infertile men (p <.0001). No significant association was found between SDF and methylation of XRCC1 and ERCC2 genes (p =.9277 and p =.8257, respectively).
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    Comparative analysis of tests used to assess sperm chromatin integrity and DNA fragmentation
    (Blackwell Publishing Ltd, 2021) Henkel, R; Dutta, S; Agarwal, A
    Male infertility has a complex etiology, and many times, the cause is unknown. While routine semen analysis provides an overview of basic semen parameters, such as sperm concentration, motility, viability and morphology, a significant overlap of these parameters has been reported in fertile and infertile men. Moreover, conventional semen parameters do not reveal the cellular or molecular mechanisms of sperm dysfunctions leading to infertility. Therefore, sperm functional parameters, including sperm chromatin integrity, are evaluated to provide information on subtle sperm defects that are not routinely identified. Incomplete or defective sperm chromatin condensation increases the susceptibility of the sperm DNA to oxidative damage or other factors. To evaluate sperm chromatin integrity, different methods with varying degrees of diagnostic and prognostic capabilities are available. Among these assays, SCSA, TUNEL and SCD assays are most commonly used. While these assays rather evaluate the DNA directly for damages, the aniline blue and chromomycin A3 stains test for the quality of chromatin condensation.
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    Diagnostic value of advanced semen analysis in evaluation of male infertility
    (Blackwell Publishing Ltd, 2021) Henkel, R; Barbarosie, C; Agarwal, A
    Conventional semen analysis is the standard of care to initially evaluate the fertility status of a male patient. However, it has some limitations and among these are failure to correctly identify the aetiology underlying fertility problems, intra- and inter-observer variability and incomplete information about sperm function. Considering these drawbacks, advanced semen tests have been developed to assess male infertility, including sperm function tests, oxidative stress (OS) and sperm DNA fragmentation (SDF) tests. This review illustrates the commonly utilised sperm function techniques, along with the assays used to assess SDF and OS and their diagnostic value.
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    Diagnostic value of routine semen analysis in clinical andrology
    (Blackwell Publishing Ltd, 2021) Henkel, R; Baskaran, S; Finelli, R
    Infertility is a major health issue affecting over 48.5 million couples around the world, with the male factor accounting for about 50% of the cases. The conventional semen analysis recommended by the World Health Organization (WHO) is the cornerstone in the evaluation of male fertility status. It includes macroscopic and microscopic evaluation of the ejaculate, which reflects the production of spermatozoa in the testes, the patency of the duct system and the glandular secretory activity. Evaluation of seminal fructose, sperm vitality and leucocytes (Endtz test) are useful adjuncts to semen analysis that provide information on specific clinical conditions. Though several computer-assisted sperm analysis (CASA) systems have been developed, conventional methods for semen analysis are still widely accepted in clinical practice. This review summarises the conventional techniques used in routine semen analysis and their diagnostic value in clinical andrology.
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    The effect of cissampelos capensis extract on prostate cancer, sertoli and leydig cell function
    (University of the Western Cape, 2014) Pearce, Keenau Mark; Henkel, R; Hiss, D
    This study investigated the effect of the C. capensis extract (0.001, 0.01, 0.1, 1, 10, 100 1000 μg/ml) on LNCaP prostate cancer, TM3 Leydig and TM4 Sertoli cells for 24 and 96 hours. The following parameters were investigated: morphology, cell viability (XTT), testosterone modulation, DNA fragmentation (TUNEL), lactate dehydrogenase activity (LDH), testosterone production, anti-cancer drug combination. In a separate set of experiments, parameters affecting the initiation, progression and metastasis of cancer were investigated. These included the ability of the aqueous C. capensis rhizome extract to inhibit of reactive oxygen species (ROS) and reactive nitrogen species (RNS) production, and to inhibit collagenase and elastase activity.
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    Environmental contaminants and male infertility: Effects and mechanisms
    (Blackwell Publishing Ltd, 2021) Henkel, R; Selvaraju, V; Baskaran, S
    The escalating prevalence of male infertility and decreasing trend in sperm quality have been correlated with rapid industrialisation and the associated discharge of an excess of synthetic substances into the environment. Humans are inevitably exposed to these ubiquitously distributed environmental contaminants, which possess the ability to intervene with the growth and function of male reproductive organs. Several epidemiological reports have correlated the blood and seminal levels of environmental contaminants with poor sperm quality. Numerous in vivo and in vitro studies have been conducted to investigate the effect of various environmental contaminants on spermatogenesis, steroidogenesis, Sertoli cells, blood–testis barrier, epididymis and sperm functions. The reported reprotoxic effects include alterations in the spermatogenic cycle, increased germ cell apoptosis, inhibition of steroidogenesis, decreased Leydig cell viability, impairment of Sertoli cell structure and function, altered expression of steroid receptors, increased permeability of blood–testis barrier, induction of peroxidative and epigenetic alterations in spermatozoa resulting in poor sperm quality and function.
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    Etiologies of sperm DNA damage and its impact on male infertility
    (Blackwell Publishing Ltd, 2021) Henkel, R; Panner Selvam, M.K; Ambar, R.F
    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.
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    Evaluation of seminal oxidation–reduction potential in male infertility
    (Blackwell Publishing Ltd, 2021) Henkel, R; Panner Selvam, M.K; Finelli, R
    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.
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    Impact of body composition analysis on male sexual function: A metabolic age study
    (Frontiers, 2023) Henkel, R
    Metabolic Age (MetAge) and body composition analysis may reflect an individual’s metabolic status, which is believed to influence male sexual and gonadal functions. Although erectile dysfunction (ED) and hypogonadism are increasingly prevalent with age, they are also detected among younger men. This study aims to assess the impact of MetAge and body composition on male sexual and gonadal status overall, and particularly in men younger than 40 years of age.
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    Male infertility
    (Lancet Publishing Group, 2021) Agarwal, A; Baskaran, S; Henkel, R
    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.
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    Polymorphisms of androgens-related genes and idiopathic male infertility in Turkish men
    (Wiley, 2021) Mahmutoglu, A; Dirie, S; Henkel, R
    Androgens, testosterone and dihydrotestosterone (DHT) are endocrine regulators of spermatogenesis and act via androgen receptor (AR). The aim of this study was to investigate the association(s) of AR (CAG repeat length), SRD5A2 (rs523349, V89L) and TNF-α (rs1800629, -308G/A) polymorphisms with idiopathic male infertility in Turkish men. This case-control study consisted of 312 men with idiopathic infertility and 113 fertile men. Polyacrylamide gel electrophoresis (PAGE) or PCR-restriction fragment length polymorphism methods were used for genotyping. The mean AR CAG repeat length was significantly longer in infertile men than in fertile men (p = 0.015). However, there was no significant association between the SRD5A2 genotypes (VV, VL and LL) and the risk of infertility (p = 0.516). The genotype frequency and allele distribution of TNF-α -308G/A polymorphism (GG, GA, AA genotypes and G, A alleles) were not associated with male infertility (p = 0.779 and p = 0.743 respectively). AR CAG repeat expansion might be one of the risk factors for idiopathic male infertility in Turkish men. Further studies investigating the association of male infertility with AR CAG, V89L and -308G/A polymorphisms are warranted to understand the possible associations among them.
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    Protein profiling in unlocking the basis of varicocele-associated infertility
    (Blackwell Publishing Ltd, 2021) Henkel, R; Panner Selvam, M.K; Baskaran, S
    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.
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    Proteomics and metabolomics — Current and future perspectives in clinical andrology
    (Blackwell Publishing Ltd, 2021) Henkel, R; Panner, Selvam M.K; Finelli, R
    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.
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    Reactive oxygen species in male reproduction: A boon or a bane?
    (Blackwell Publishing Ltd, 2021) Henkel, R; Baskaran, S; Finelli, R
    Reactive oxygen species (ROS) are free radicals derived from oxygen during normal cellular metabolism. ROS play a crucial role in the physiological processes and signalling pathways associated with male fertility. At physiological concentrations, ROS act as molecular mediators of signal transduction pathways involved in the regulation of the hypothalamic–pituitary–gonadal axis, spermatogenesis and steroidogenesis. They also trigger the morphological changes required for sperm maturation, such as DNA compaction and flagellar modification. Furthermore, ROS modulate crucial processes involved in the attainment of sperm fertilising ability such as capacitation, hyperactivation, acrosome reaction and sperm–oocyte fusion. Conversely, oxidative stress prevails when the concentration of ROS overwhelms the body's antioxidant defence. Various endogenous and exogenous factors enhance the synthesis of ROS resulting in the disruption of structural and functional integrity of spermatozoa through the induction of apoptotic pathway and oxidation of molecules, such as lipids, proteins and DNA.
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    The role of infections and leukocytes in male infertility
    (Blackwell Publishing Ltd, 2021) Henkel, R; Offor, U; Fisher, D
    Declining birth rates are one of the problems facing society today. Male counterparts are responsible for about half of the infertility cases, and genitourinary tract infections may play a contributing role in approximately 15% of male infertility cases. Leukocytospermia is an established indicator of infection in the male urogenital tract, although other microorganisms such as bacteria and virus may also be contributors to the etiology of male infertility. The pathophysiology of these infectious agents may be initiated by a local inflammatory reaction resulting in an increase in reactive oxygen species (ROS). This results in testicular injury, thereby affecting sperm morphology, sperm motility, sperm viability and elevation of the seminal leukocyte as a result of the genital tract infection. The infectious and inflammatory changes can result in male infertility. It is proposed that high concentrations of seminal leukocyte and infectious agents may affect sperm function resulting in clumping of motile spermatozoa, decreasing acrosomal functionality and also causing alterations in sperm morphology.
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    A scientometric analysis of research publications on male infertility and assisted reproductive technology
    (Blackwell Publishing Ltd, 2021) Henkel, R; Agarwal, A; Panner Selvam, M.K
    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.
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    Total antioxidant capacity—Relevance, methods and clinical implications
    (Blackwell Publishing Ltd, 2021) Henkel, R; Gupta, S; Finelli, R
    Oxidative stress is pre-empted by an adequate level of antioxidants, which scavenge oxidants when they are produced in excess by different sources, including leukocytes and immature spermatozoa. Enzymatic antioxidants, such as superoxide dismutase, catalase and glutathione peroxidase, and several non-enzymatic antioxidants (proteins, vitamins and minerals), working as oxidant scavengers and cofactors of enzymatic antioxidants have been identified in seminal plasma. The total antioxidant capacity (TAC) is a diagnostic test that can be utilised in the male infertility workup. TAC measures the amount of total antioxidants in seminal plasma. Therefore, it provides an assessment of the reductive potential in seminal plasma. Several studies have investigated the diagnostic application of TAC in various andrology conditions. There is substantial evidence in the literature to show that infertile patients have lower seminal TAC in comparison with fertile men.
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    TUNEL assay—Standardized method for testing sperm DNA fragmentation
    (Blackwell Publishing Ltd, 2021) Henkel, R; Sharma, R; Iovine, C
    Sperm DNA integrity is important for normal functions such as fertilization, implantation, pregnancy and fetal development. Sperm DNA fragmentation (SDF) is more common in infertile men and may be responsible for poor reproductive function. Although there are a number of tests available to measure SDF, the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-nick end labelling TUNEL) assay using flow cytometry is becoming more popular to measure the sperm DNA fragmentation. It is a direct test that measures both single- and double- DNA strand breaks. In this review, we describe the protocol, quality control and measurement of sperm DNA fragmentation using a benchtop flow cytometer.
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    An update on the techniques used to measure oxidative stress in seminal plasma
    (Blackwell Publishing Ltd, 2021) Henkel, R; Robert, K.A; Sharma, R
    Reactive oxygen species (ROS) are produced in significant amounts by spermatozoa and leucocytes. They are necessary to carry out various physiological functions such as sperm capacitation, hyperactivation, acrosome reaction, sperm-zona binding and cellular signalling pathways. Oxidative stress (OS) results when the ROS levels overwhelm the available antioxidant reserve. A number of direct and indirect tests have been developed to assess oxidative stress. In this manuscript, we discuss these common direct and indirect tests as well as their advantages and disadvantages. Tests measuring sperm dysfunction secondary to oxidative stress such as lipid peroxidation, DNA fragmentation and protein alterations are also described.