Research progress on the effect of sperm chromatin integrity on function and its detection methods.

Sperm chromatin not only carries genetic information such as paternal DNA, but also carries structural proteins, epigenetic information, and higher-order chromatin structures (such as matrix attachment regions and telomeres), etc. These information play an important role in embryonic development. This article mainly reviews the effects of these different information carried by sperm chromatin on sperm function and embryonic development and the research progress of related detection methods, in order to provide a theoretical basis and scientific diagnosis and treatment strategies for the etiology screening of clinical infertility, embryo arrest and recurrent miscarriage, so as to improve the pregnancy outcomes of natural conception and assisted reproduction. Keywords: sperm chromatin; epigenetics; sperm DNA damage; sperm function; higher-order chromatin structures.

Low levels of mouse sperm chromatin fragmentation delay embryo development.

We previously demonstrated that MnCl2 induces double-stranded DNA breaks in sperm in a process that we term as sperm chromatin fragmentation. Here, we tested if the levels of double-stranded DNA breaks were corelated to the concentration of MnCl2, and we compared this to another agent that causes single-stranded DNA breaks, H2O2. We found that both methods have the advantage of inducing DNA breaks in a concentration-dependent manner. Mouse sperm were treated with varying concentrations of either H2O2 or MnCl2, and the DNA damage was assessed by pulse-field gel electrophoresis, and the alkaline and neutral comet assays. Oocytes were injected with either treated sperm and the resulting embryos analyzed with an embryoscope to detect subtle changes in embryonic development. We confirmed that H2O2 treatment induced primarily single-stranded DNA breaks and MnCl2 induced primarily double-stranded DNA breaks, indicating different mechanisms of damage. These sperm were injected into oocytes, and the development of the resulting embryos followed with an embryoscope equipped with time lapse recording. We found that aberrations in early embryonic development by day 2 with even the lowest levels of DNA damage and that the levels of embryonic aberrations correlated to the concentration of either H2O2 or MnCl2. Low levels of H2O2 caused significantly more aberrations in embryonic development than low levels of MnCl2 even though the levels of DNA damage as measured by comet assays were similar. These data demonstrate that even low levels of sperm DNA damage cause delays and arrests in embryonic development.

Investigation on the mechanisms of human sperm DNA damage based on the proteomics analysis by SWATH-MS.

BACKGROUND: Spermatozoa have the task of delivering an intact paternal genome to the oocyte and supporting successful embryo development. The detection of sperm DNA fragmentation (SDF) has been emerging as a complementary test to conventional semen analysis for male infertility evaluation, but the mechanism leading to SDF and its impact on assisted reproduction remain unclear. Therefore, the study identified and analyzed the differentially expressed proteins of sperm with high and low SDF. METHODS: Semen samples from men attended the infertility clinic during June 2020 and August 2020 were analyzed, and sperm DNA fragmentation index (DFI) was detected by the sperm chromatin structure assay. Semen samples with low DFI (< 30%, control group) and high DFI (≥ 30%, experimental group) were optimized by density gradient centrifugation (DGC), and the differentially expressed proteins of obtained sperm were identified by the Sequential Window Acquisition of All Theoretical Mass Spectra Mass Spectrometry (SWATH-MS) and performed GO and KEGG analysis. RESULTS: A total of 2186 proteins were identified and 1591 proteins were quantified, of which 252 proteins were identified as differentially expressed proteins, including 124 upregulated and 128 downregulated. These differentially expressed proteins were involved in metabolic pathways, replication/recombination/repair, acrosomal vesicles, kinase regulators, fertilization, tyrosine metabolism, etc. Western blotting results showed that the expression levels of RAD23B and DFFA proteins and the levels of posttranslational ubiquitination and acetylation modifications in the experimental group were significantly higher than those in the control group, which was consistent with the results of proteomics analysis. CONCLUSIONS: Proteomic markers of sperm with high DNA fragmentation can be identified by the SWATH-MS and bioinformatic analysis, and new protein markers and posttranslational modifications related to sperm DNA damage are expected to be intensively explored. Our findings may improve our understanding of the basic molecular mechanism of sperm DNA damage.

Male reproductive ageing: a radical road to ruin.

In modern post-transition societies, we are reproducing later and living longer. While the impact of age on female reproductive function has been well studied, much less is known about the intersection of age and male reproduction. Our current understanding is that advancing age brings forth a progressive decline in male fertility accompanied by a reduction in circulating testosterone levels and the appearance of age-dependent reproductive pathologies including benign prostatic hypertrophy and erectile dysfunction. Paternal ageing is also associated with a profound increase in sperm DNA damage, the appearance of multiple epigenetic changes in the germ line and an elevated mutational load in the offspring. The net result of such changes is an increase in the disease burden carried by the progeny of ageing males, including dominant genetic diseases such as Apert syndrome and achondroplasia, as well as neuropsychiatric conditions including autism and spontaneous schizophrenia. The genetic basis of these age-related effects appears to involve two fundamental mechanisms. The first is a positive selection mechanism whereby stem cells containing mutations in a mitogen-activated protein kinase pathway gain a selective advantage over their non-mutant counterparts and exhibit significant clonal expansion with the passage of time. The second is dependent on an age-dependent increase in oxidative stress which impairs the steroidogenic capacity of the Leydig cells, disrupts the ability of Sertoli cells to support the normal differentiation of germ cells, and disrupts the functional and genetic integrity of spermatozoa. Given the central importance of oxidative stress in defining the impact of chronological age on male reproduction, there may be a role for antioxidants in the clinical management of this process. While animal studies are supportive of this strategy, carefully designed clinical trials are now needed if we are to realize the therapeutic potential of this approach in a clinical context.

Investigation of the mechanisms leading to human sperm DNA damage based on transcriptome analysis by RNA-seq techniques.

RESEARCH QUESTION: What are the molecular mechanisms leading to human sperm DNA damage? DESIGN: Semen samples were collected and the sperm DNA fragmentation index (DFI) was assessed. Differentially expressed RNA in spermatozoa with a high (DFI ≥30%, experimental group) or normal (DFI <30%, control group) DFI were identified by RNA-sequencing (RNA-seq) technology, and Gene Ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis was performed. Three differentially expressed RNA related to sperm DNA damage and repair, namely PMS1, TP53BP1 and TLK2, were validated using real-time quantitative (RT-qPCR). RESULTS: A total of 19,970 expressed RNA were detected in the two groups. Compared with the control group, the expression levels of 189 RNA in the experimental group were significantly increased and those of 163 genes decreased. Gene Ontology enrichment analysis showed that these RNA were mainly concentrated in the ATPase-dependent transmembrane transport complex, extracellular exosome, somatic cell DNA recombination, protein binding, cytoplasm and regulation of localization. KEGG pathway analysis showed that these RNA were mainly related to the PI3K-Akt signalling pathway, endocytosis, p53 signalling pathway and cGMP-PKG signalling pathway. The RT-qPCR results showed that the expression levels of PMS1, TP53BP1 and TLK2 in the experimental group were significantly lower than in the control group (P = 0.01, 0.015 and 0.004, respectively), which was identical to the results of RNA sequencing. CONCLUSIONS: Differentially expressed RNA related to sperm DNA damage and repair may be identified by RNA-seq technology, which provides new insights into the understanding of sperm DNA damage and repair, and will help to discover new biomarkers related to sperm DNA damage.

Cryopreservation of Human Spermatozoa: Functional, Molecular and Clinical Aspects.

Cryopreservation is an expanding strategy to allow not only fertility preservation for individuals who need such procedures because of gonadotoxic treatments, active duty in dangerous occupations or social reasons and gamete donation for couples where conception is denied, but also for animal breeding and preservation of endangered animal species. Despite the improvement in semen cryopreservation techniques and the worldwide expansion of semen banks, damage to spermatozoa and the consequent impairment of its functions still remain unsolved problems, conditioning the choice of the technique in assisted reproduction procedures. Although many studies have attempted to find solutions to limit sperm damage following cryopreservation and identify possible markers of damage susceptibility, active research in this field is still required in order to optimize the process. Here, we review the available evidence regarding structural, molecular and functional damage occurring in cryopreserved human spermatozoa and the possible strategies to prevent it and optimize the procedures. Finally, we review the results on assisted reproduction technique (ARTs) outcomes following the use of cryopreserved spermatozoa.

DNA repair and response to sperm DNA damage in oocytes and embryos, and the potential consequences in ART: a systematic review.

Sperm DNA damage is considered a predictive factor for the clinical outcomes of patients undergoing ART. Laboratory evidence suggests that zygotes and developing embryos have adopted specific response and repair mechanisms to repair DNA damage of paternal origin. We have conducted a systematic review in accordance with guidelines from Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) to identify and review the maternal mechanisms used to respond and repair sperm DNA damage during early embryonic development, how these mechanisms operate and their potential clinical implications. The literature search was conducted in Ovid MEDLINE and Embase databases until May 2021. Out of 6297 articles initially identified, 36 studies were found to be relevant through cross referencing and were fully extracted. The collective evidence in human and animal models indicate that the early embryo has the capacity to repair DNA damage within sperm by activating maternally driven mechanisms throughout embryonic development. However, this capacity is limited and likely declines with age. The link between age and decreased DNA repair capacity could explain decreased oocyte quality in older women, poor reproductive outcomes in idiopathic cases and patients who present high sperm DNA damage. Ultimately, further understanding mechanisms underlying the maternal repair of sperm DNA damage could lead to the development of targeted therapies to decrease sperm DNA damage, improved oocyte quality to combat incoming DNA insults or lead to development of methodologies to identify individual spermatozoa without DNA damage.

Poor semen parameters are associated with abnormal methylation of imprinted genes in sperm DNA.

BACKGROUND: Altered sperm DNA methylation patterns of imprinted genes as well as certain spermatogenesis-related genes has been proposed as a possible mechanism of male subfertility. Some reports suggest that there is an elevated risk of congenital diseases, associated with imprinted genes, in children conceived via intra-cytoplasmic sperm injection, due to the involvement of spermatozoa with aberrant imprinted genes obtained from infertile men. METHODS: In this study, the DNA methylation status of the promoter regions of six imprinted genes, namely potassium voltage-gated channel subfamily Q member 1 (KCNQ1), maternally expressed gene 3 (MEG3), insulin-like growth factor 2 (IGF-2), KCNQ1 overlapping transcript 1 (KCNQ1OT1), mesoderm specific transcript (MEST), and paternally expressed gene 3 (PEG3), were detected by a next generation sequencing-based multiple methylation-specific polymerase chain reaction analysis of sperm samples obtained from 166 men who sought fertility evaluation in our Reproductive Medicine Center. Thereafter, the semen samples were classified into subgroups according to sperm motility and DNA integrity status. RESULTS: As compared to the normozoospermic group, the samples of the asthenospermic group exhibited significant hypermethylation in two CpG sites of IGF-2 and significant hypomethylation in one CpG site of KCNQ1 as well as three CpG sites of MEST (P < 0.05). However, we did not observe any significant differences in the overall methylation levels of these six imprinted genes (P > 0.05). Additionally, we found that 111 of 323 CpG sites were hypomethylated in the group with DNA fragmentation index (DFI) ≥ 30% as compared to the group with DFI < 30% (P < 0.05). In this case, there were significant differences in the overall methylation levels of MEG3, IGF-2, MEST, and PEG3 (P < 0.05), but not in that of KCNQ1OT1 and KCNQ1 (P > 0.05). Hence, aberrant methylation patterns of imprinted genes were more prevalent in males with poor sperm quality, especially in those with severe sperm DNA damage. CONCLUSION: In conclusion, abnormal DNA methylation of some CpG sites of imprinted genes are associated with poor sperm quality, including asthenospermia and severe sperm DNA impairment.

Revisiting the impact of varicocele and its treatments on male fertility.

Varicocele is one of the most common, yet treatable, causes of male infertility. Varicoceles are present in more than 40% of infertile men with primary infertility, a figure that increases with age. Varicoceles impair semen parameters and sperm DNA and are linked with lower pregnancy and live birth rates. Until recently, men had seldom been examined in male fertility workups. This is changing as urologists have become recognized as team members in infertility. Hence identification and treatment are available as never before. Furthermore, as men become aware that they are as likely as their female partners to be infertile, they want equal 'couple care', requesting urological referrals as they realize that they can improve their semen quality and chances of fatherhood without or before fertility treatment. There is now a greater understanding of the mechanisms of varicocele-induced damage by oxidative stress, using sperm DNA as a sensitive biomarker of sperm quality. There is a current consensus that varicocele is linked to poor semen and repair improves semen and sperm DNA quality. Evidence is strengthening to indicate that varicocele repair increases pregnancy and live birth rates in natural conception and following fertility treatment.

Sperm DNA damage compromises embryo development, but not oocyte fertilisation in pigs.

BACKGROUND: The assessment of sperm DNA integrity has been proposed as a complementary test to conventional mammalian semen analysis. In this sense, single-strand (SSB) and double-strand (DSB) DNA breaks, the two types of sperm DNA fragmentation (SDF), have been reported to have different aetiologies and to be associated to different fertility outcomes in bovine and humans. Considering that no studies in porcine have addressed how SDF may affect sperm quality and fertility outcomes, the present work aimed to determine the impact of global DNA damage, SSB and DSB on sperm quality and in vitro fertilising ability. To this end, 24 ejaculates (one per boar) were split into three aliquots: the first was used to assess sperm quality parameters through a computer-assisted sperm analysis (CASA) system and flow cytometry; the second was used to perform in vitro fertilisation, and the third, to evaluate sperm DNA integrity using alkaline and neutral Comet assays. RESULTS: The results showed that global DNA damage negatively correlates (P < 0.05) with normal sperm morphology (R = - 0.460) and progressive motility (R = - 0.419), and positively with the percentage of non-viable sperm (R = 0.507). Multiple regression analyses showed that non-viable sperm were related to SSB (ß = - 0.754). In addition, while fertilisation did not seem to be affected by sperm DNA integrity, global DNA damage, DSB and SSB were found to be correlated to embryo development outcomes. Specifically, whereas global DNA damage and DSB negatively affected (P < 0.05) the later preimplantation embryo stages (percentage of early blastocyst/blastocyst D6: for global DNA damage, R = - 0.458, and for DSB, R = - 0.551; and percentage of hatching/hatched blastocyst D6: for global DNA damage, R = - 0.505, and for DSB, R = - 0.447), global DNA damage and SSB had a negative impact (P < 0.05) on the developmental competency of fertilised embryos (R = - 0.532 and R = - 0.515, respectively). Remarkably, multiple regression analyses supported the associations found in correlation analyses. Finally, the present work also found that the inclusion of Comet assays to the conventional sperm quality tests improves the prediction of blastocyst formation (AUC = 0.9021, P < 0.05), but not fertilisation rates (P > 0.05). CONCLUSION: Considering all these findings, this work sets a useful model to study how SDF negatively influences fertility.

High DNA stainability (HDS) should not be recommended as a marker for the detection of sperm DNA damage.

There was a marker of high DNA stainability (HDS) in the detection of sperm DNA damage, which was defined as the sperm with high green stainability (HIGRN). The sperm with normal double-stranded DNA was stained green by acridine orange (AO). However, the sperm with high green fluorescence or HDS were thought of as immature sperm or the sperm with poor chromatin condensation. Some previous literature reported that the proportion of sperm with HDS increased with age, and had a certain correlation with the poor outcome of assisted reproductive technology. Recently, several articles reported that the marker of HDS decreased linearly with age, which was obviously inconsistent with that reported by the previous literature. In this case, what kind of marker is HDS? Is it worth studying? After extensively reading the literature related to HDS and flow cytometry related books and performing a series of studies related to the detection of sperm DNA damage, we believe that the establishment of HDS in the detection of sperm DNA damage has no theoretical basis and also no support of evidence-based medicine and that using HDS as a marker in the detection of sperm DNA integrity is inappropriate.

Effect of varicocele on sperm DNA damage: A systematic review and meta-analysis.

The updated meta-analysis was conducted to further verify the effect of varicocele on sperm DNA damage, supplying clinicians and researchers with high-grade evidence. The sperm DNA damage was evaluated by DNA fragmentation index (DFI), associated with the male fertility capability tightly. PubMed, Web of Science and Cochrane Library were searched extensively for eligible studies with the search terms: varicocele, sperm DNA and sperm DNA damage. Finally, a total of 12 studies were included in our meta-analysis with a total of 845 patients diagnosed with varicocele and 2,377 healthy controls. A statistical difference of DFI between varicocele patients and healthy controls was found after pooling the data ((Standardised mean difference) SMD: 1.40, 95%CI: 0.83-1.98, p < .0001), using the random effect model. We conducted subgroup analysis according to study region (Brazil and Other countries), detection methods of DFI (TUNEL, Comet, and SCSA), sample size (<50 and >50) and age (<30 and >30 years), based on substantial heterogeneity among eligible studies. The stability of pooled results was verified by sensitivity analysis. All these statistical analyses were conducted using Stata version 16.0. In conclusion, patients diagnosed with clinical varicocele had higher DFI than healthy controls, which means varicocele could impair sperm DNA, consequently the fertility potential of affected men.

Protamines and DNA integrity as a biomarkers of sperm quality and assisted conception outcome.

Present research aim was to identify functional tests in semen associated with DNA damage and chromatin maturity (protamination) which predict the outcome in assisted reproduction. Couples were grouped according to male partner semen parameters, into normozoospermia (NZs), severe male factor (SMF) and mild male factor (MMF). DNA fragmentation index (DFI) in spermatozoa was analysed by sperms chromatin dispersion (SCD), sperm chromatin structure assay (SCSA) and acridine orange testing (AOT). Chromomycin A3 (CMA3) and toluidine blue (TB) staining to measure sperm chromatin maturity (CM). DFI and chromatin decondensation were significantly lower in N compared to male factor categories (MMF and SMF). Aneuploidy embryos were significantly higher in couples with male factor infertility (MMF and SMF). A positive correlation was observed between fertilization rate (FR) and live birth rate (LBR) with sperm concentration, motility, vitality, normal sperm morphology and negative correlation between sperm DFI and sperm CM. No correlation was observed between embryo aneuploidy and sperm DFI or CM. Lower percentage of spermatozoa chromatin integrity are associated with low fertilization and live birth rate. Male factor infertility, due to impaired semen parameters and chromatin defects could be regarded in future as an indication of IVF/ICSI, and predictor of assisted reproductive techniques outcome.

Molecular Clues to Understanding Causes of Human-Assisted Reproduction Treatment Failures and Possible Treatment Options.

More than forty years after the first birth following in vitro fertilization (IVF), the success rates of IVF and of IVF-derived assisted reproduction techniques (ART) still remain relatively low. Interindividual differences between infertile couples and the nature of the problems underlying their infertility appear to be underestimated nowadays. Consequently, the molecular basis of each couple's reproductive function and of its disturbances is needed to offer an individualized diagnostic and therapeutic approaches to each couple, instead of applying a standard or minimally adapted protocols to everybody. Interindividual differences include sperm and oocyte function and health status, early (preimplantation) embryonic development, the optimal window of uterine receptivity for the implanting embryo, the function of the corpus luteum as the main source of progesterone production during the first days of pregnancy, the timing of the subsequent luteoplacental shift in progesterone production, and aberrant reactions of the uterine immune cells to the implanting and recently implanted embryos. In this article, the molecular basis that underlies each of these abnormalities is reviewed and discussed, with the aim to design specific treatment options to be used for each of them.

In vitro ameliorative effects of ellagic acid on vitality, motility and DNA quality in human spermatozoa.

Oxidative stress (OS) plays a significant role in the etiology of male infertility, resulting in the impairment of male reproduction. This condition, characterized by an imbalance in the levels of oxidizing and antioxidant species in the seminal fluid, has a harmful impact on sperm functions and DNA integrity. The present study aimed to evaluate the anti-genotoxic action of ellagic acid, a polyphenolic molecule of natural origin having a powerful antigenotoxic, anti-inflammatory and antiproliferative role. An OS condition was induced in vitro by incubating normozoospermic human semen samples in benzene for 45, 60 and 90 min. DNA integrity was evaluated by terminal deoxynucleotidyl transferase dUTP nick end labeling assay, RAPD-PCR was performed to calculate the genome template stability, while the percentage of intracellular reactive oxygen species (ROS) was assessed by the 2', 7'-dichlorofluorescein assay. Our results showed that ellagic acid has a consistent protective effect on DNA integrity, as well as on sperm vitality and motility, by counteracting generation of intracellular ROS. The results of this study suggest ellagic acid as a suitable molecule to protect sperm DNA from oxidative stress, with a potentially significant translational impact on the management of the male infertility.

A systematic overview of the spermatotoxic and genotoxic effects of methotrexate, ganciclovir and mycophenolate mofetil.

INTRODUCTION: Immunosuppressant drugs are increasingly being used in the reproductive years. Theoretically, such medications could affect fetal health either through changes in the sperm DNA or through fetal exposure caused by a presence in the seminal fluid. This systematic overview summarizes existing literature on the spermatotoxic and genotoxic potentials of methotrexate (MTX), a drug widely used to treat rheumatic and dermatologic diseases, and mycophenolate mofetil (MMF), which alone or supplemented with ganciclovir (GCV) may be crucial for the survival of organ transplants. MATERIAL AND METHODS: The systematic overview was performed in accordance with the PRISMA guidelines: A systematic literature search of the MEDLINE and Embase databases was done using a combination of relevant terms to search for studies on spermatotoxic or genotoxic changes related to treatment with MTX, GCV or MMF. The search was restricted to English language literature, and to in vivo animal studies (mammalian species) and clinical human studies. RESULTS: A total of 102 studies were identified, hereof 25 human and 77 animal studies. For MTX, human studies of immunosuppressive dosages show transient effect on sperm quality parameters, which return to reference values within 3 months. No human studies have investigated the sperm DNA damaging effect of MTX, but in other organs the genotoxic effects of immunosuppressive doses of MTX are fluctuating. In animals, immunosuppressive and cytotoxic doses of MTX adversely affect sperm quality parameters and show widespread genotoxic damages in various organs. Cytotoxic doses transiently change the DNA material in all cell stages of spermatogenesis in rodents. For GCV and MMF, data are limited and the results are indeterminate, for which reason spermatotoxic and genotoxic potentials cannot be excluded. CONCLUSIONS: Data from human and animal studies indicate transient spermatotoxic and genotoxic potentials of immunosuppressive and cytotoxic doses of MTX. There are a limited number of studies investigating GCV and MMF.

How defective spermatogenesis affects sperm DNA integrity.

Spermatogenesis is the essential process to maintain and promote male fertility. It is extraordinarily complex with many regulatory elements and numerous steps. The process involves several cell types, regulatory molecules, repair mechanisms and epigenetic regulators. Evidence has shown that fertility can be negatively impacted by reduced sperm DNA integrity. Sources of sperm DNA damage include replication errors and causes of DNA fragmentation which include abortive apoptosis, defective maturation and oxidative stress. This review outlines the process of spermatogenesis, spermatogonial regulation and sperm differentiation; additionally, DNA damage and currently studied DNA repair mechanisms in spermatozoon are also covered.

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.

Chronic Prostatitis/Chronic Pelvic Pain Syndrome Leads to Impaired Semen Parameters, Increased Sperm DNA Fragmentation and Unfavorable Changes of Sperm Protamine mRNA Ratio.

BACKGROUND: Chronic Prostatitis/Chronic Pelvic Pain Syndrome (CP/CPPS) is a frequent disease affecting men of every age and accounting for a great number of consultations at urology departments. Previous studies suggested a negative impact of CP/CPPS on fertility. As increasing attention has been attributed to additional aspects, such as sperm DNA integrity and sperm protein alterations, besides the WHO standard semen analysis when assessing male fertility, in this prospective study, we aimed to further characterize the fertility status in CP/CPPS patients with a focus on these parameters. METHODS: Sperm DNA fragmentation measured by sperm chromatin structure assay (SCSA) and protamine 1 to protamine 2 mRNA ratio assessed by RT-qPCR were analyzed along with conventional ejaculate parameters and inflammatory markers in 41 CP/CPPS patients and 22 healthy volunteers. RESULTS: We found significant differences between the groups concerning multiple conventional ejaculate parameters. A significant increase in sperm DNA fragmentation was shown in CP/CPPS patients with association to other sperm parameters. The majority of CP/CPPS patients exhibited protamine mRNA ratios out of the range of regular fertility. CONCLUSIONS: This is a pioneering study with a strong practical orientation revealing that CP/CPPS leads to increased sperm DNA damage and changes in sperm protamine levels, emphasizing an unfavorable impact of CP/CPPS on fertility.

The effects of levamisole and albendazole on spermatological parameters, testosterone levels, and sperm DNA damage in Saanen bucks.

This study aimed to investigate the effect of levamisole and albendazole on spermatological parameters, testosterone levels, and sperm DNA damage in Saanen bucks. For this purpose, twenty-four Saanen bucks were divided into three groups as control, levamisole, and albendazole administration group. The control group received only water (20 ml, oral), the levamisole group received 7.5 mg/kg of levamisole (2 oral tablets once daily for 2 days) + water (20 ml, oral), and the albendazole group received 7.5 mg/kg of albendazole (1 oral tablet) + water (20 ml, oral). Semen and blood samples were collected from all animals, both before drug application (day 0) and within a 2-day interval after drug application between day 1 (day of the treatment) and day 11. Spermatological parameters were evaluated immediately after collection. Testosterone levels were also measured from the blood samples with ELISA. Sperm DNA damage was determined with comet assay. The present research showed that especially albendazole administration decreased spermatological parameters and levamisole administration decreased testosterone levels. Significant sperm DNA damage was seen after both albendazole and levamisole administration. As a result, albendazole and levamisole administration should be used carefully on Saanen bucks, especially during the breeding season.