Insight into oxidative stress in varicocele-associated male infertility: part 2

From pathophysiology to practice: addressing oxidative stress and sperm DNA fragmentation in Varicocele-affected subfertile men

Varicocele can reduce male fertility potential through various oxidative stress mechanisms. Excessive production of reactive oxygen species may overwhelm the sperm's defenses against oxidative stress, damaging the sperm chromatin. Sperm DNA fragmentation, in the form of DNA strand breaks, is recognized as a consequence of the oxidative stress cascade and is commonly found in the ejaculates of men with varicocele and fertility issues. This paper reviews the current knowledge regarding the association between varicocele, oxidative stress, sperm DNA fragmentation, and male infertility, and examines the role of varicocele repair in alleviating oxidative-sperm DNA fragmentation in these patients. Additionally, we highlight areas for further research to address knowledge gaps relevant to clinical practice.

Investigation of sperm hsa-mir-145-5p and MLH1 expressions, seminal oxidative stress and sperm DNA fragmentation in varicocele

BACKGROUND

Mechanisms by which varicocele causes infertility are not clear and few studies have reported that some miRNAs show expression alterations in men with varicocele. Recently, sperm promoter methylation of MLH1 has been shown to be higher in men diagnosed with varicocele. This study aimed to assess the potential effects of miR-145, which was determined to target MLH1 mRNA in silico on sperm quality and function in varicocele.

METHODS

Sperm miR-145 and MLH1 expressions of six infertile men with varicocele (Group 1), nine idiopathic infertile men (Group 2), and nine fertile men (control group) were analyzed by quantitative PCR. Sperm DNA fragmentation was evaluated by TUNEL and the levels of seminal oxidative damage and total antioxidant capacity were analyzed by ELISA.

RESULTS

Our results have shown that sperm expression of miR-145 was decreased in Group 1 compared to Group 2 (P = 0.029). MLH1 expression was significantly higher in Group 2 than the controls (P = 0.048). Total antioxidant level and sperm DNA fragmentations of Group 1 and Group 2 were decreased (P = 0.001 and P = 0.011, respectively). Total antioxidant capacity was positively correlated with sperm concentration (ρ = 0.475, P = 0.019), total sperm count (ρ = 0.427, P = 0.037), motility (ρ = 0.716, P < 0.0001) and normal morphological forms (ρ = 0.613, P = 0.001) and negatively correlated with the seminal oxidative damage (ρ=-0.829, P = 0.042) in varicocele patients.

CONCLUSION

This is the first study investigating the expressions of sperm miR-145 and MLH1 in varicocele patients. Further studies are needed to clarify the potential effect of miR-145 on male fertility.

Effect of varicocele and varicocelectomy on sperm deoxyribonucleic acid fragmentation rates in infertile men with clinical varicocele

Varicocele is the leading cause of male infertility. It can affect sperm quantity and quality through various non-mutually exclusive pathophysiological mechanisms, mainly oxidative stress. Excessive production of reactive oxygen species may overwhelm the sperm's defenses against oxidative stress and harm the sperm's DNA. Excessive sperm DNA breaks, so-called sperm DNA fragmentation, result from the oxidative stress cascade and are commonly found in the ejaculates of men with varicocele and fertility-related issues. Measuring sperm DNA fragmentation can provide valuable information on the extent of harm and might help select candidates for surgical treatment. Varicocelectomy is beneficial for alleviating oxidative stress-associated infertility and improving sperm DNA integrity. However, reproductive outcomes of infertile men with elevated sperm DNA fragmentation rates and surgically treated varicoceles remain poorly studied, and there is a need for well-designed trials to determine the impact of sperm DNA fragmentation reduction on natural and medically assisted reproduction.

Controversy and Consensus on the Management of Elevated Sperm DNA Fragmentation in Male Infertility: A Global Survey, Current Guidelines, and Expert Recommendations

PURPOSE

Sperm DNA fragmentation (SDF) has been associated with male infertility and poor outcomes of assisted reproductive technology (ART). The purpose of this study was to investigate global practices related to the management of elevated SDF in infertile men, summarize the relevant professional society recommendations, and provide expert recommendations for managing this condition.

MATERIALS AND METHODS

An online global survey on clinical practices related to SDF was disseminated to reproductive clinicians, according to the CHERRIES checklist criteria. Management protocols for various conditions associated with SDF were captured and compared to the relevant recommendations in professional society guidelines and the appropriate available evidence. Expert recommendations and consensus on the management of infertile men with elevated SDF were then formulated and adapted using the Delphi method.

RESULTS

A total of 436 experts from 55 different countries submitted responses. As an initial approach, 79.1% of reproductive experts recommend lifestyle modifications for infertile men with elevated SDF, and 76.9% prescribe empiric antioxidants. Regarding antioxidant duration, 39.3% recommend 4-6 months and 38.1% recommend 3 months. For men with unexplained or idiopathic infertility, and couples experiencing recurrent miscarriages associated with elevated SDF, most respondents refer to ART 6 months after failure of conservative and empiric medical management. Infertile men with clinical varicocele, normal conventional semen parameters, and elevated SDF are offered varicocele repair immediately after diagnosis by 31.4%, and after failure of antioxidants and conservative measures by 40.9%. Sperm selection techniques and testicular sperm extraction are also management options for couples undergoing ART. For most questions, heterogenous practices were demonstrated.

CONCLUSIONS

This paper presents the results of a large global survey on the management of infertile men with elevated SDF and reveals a lack of consensus among clinicians. Furthermore, it demonstrates the scarcity of professional society guidelines in this regard and attempts to highlight the relevant evidence. Expert recommendations are proposed to help guide clinicians.

Cyanidin-3-O-glucoside and protocatechuic acid alleviate heat stress-induced testicular damage

Testicular hyperthermia induced by unhealthy living habits and pathological or occupational factors can cause spermatogenic dysfunction with an outcome of sub-fertility or even infertility. Cyanidin-3-O-glucoside (C3G) is the most typical anthocyanin in foods that has been recognized as an antioxidant with promising protection for male reproduction. However, its specific effect against testicular hyperthermia and the mechanisms involving its primary gastrointestinal metabolite protocatechuic acid (PCA) are still unexplored. In the present study, testicular hyperthermia in mice was established by employing a single hot water bath at 43 °C for 30 min. C3G and PCA were intragastrically given to investigate their prevention ability against heat stress-induced testicular damage. It was found that C3G and PCA restored the external diameter and thickness, and alleviated atrophy and vacuolation of seminiferous tubules. Simultaneously, C3G and PCA enhanced testicular heat stress tolerance through reducing superfluous eIF2α phosphorylation and stress granule formation. C3G and PCA effectively improved the testicular antioxidant system and regulated the IRE1α-XBP1 pathway, contributing to mitigatory spermatogenesis dysfunction and testicular damage. This finding revealed that anthocyanins were the novel compounds for alleviating testicular damage, and provided a reliable theoretical basis for improving male fertility disturbed by heat stress.

The Role and Place of Antioxidants in the Treatment of Male Infertility Caused by Varicocele

The inability to become pregnant for at least 1 year despite regular unprotected intercourse may indicate infertility of one or both partners. This problem affects approximately 10-20% of couples worldwide, regardless of race, with male infertility reported to account for 25-60% of cases. Among the most common pathological causes of male infertility is the presence of varicocele and chronic infections of the male reproductive system. This study was performed using data collected at the Genesis Infertility Treatment Clinic, Bydgoszcz, Poland, between 1 January 2015 and 30 June 2017. A total of 163 men meeting the inclusion criteria were selected and divided into the idiopathic infertility group (78 men) and varicocele-related infertility group (85 men). All patients received treatment with a male fertility supplement containing a combination of 1725 mg of L-carnitine fumarate, 500 mg of acetyl-L-carnitine, 90 mg of vitamin C, 20 mg of coenzyme Q10, 10 mg of zinc, 200 µg of folic acid, 50 µg of selenium, and 1.5 µg of vitamin B12 (Proxeed® Plus, Sigma-Tau, Italy) twice a day for a period of 6 months from the time of the diagnosis of infertility. The treatment resulted in significant improvements in general semen parameters, particularly sperm count, sperm concentration, total motility, and progressive motility. This antioxidant therapy produced a particularly marked therapeutic benefit in patients with Grade III varicocele, with a greater improvement in progressive motility than in men with less severe or no varicocele. The use of the antioxidant preparation examined here seems reasonable in men with idiopathic infertility and as an adjuvant in those with varicocele-related infertility in whom surgical treatment has resulted in no improvement. Its use should be considered particularly in patients with Grade III varicocele who do not wish to undergo surgical treatment or in whom such a treatment is not possible for various reasons.

Is Parthanatos Involved in Varicocele?

Varicoceles (VCs) have received widespread attention as a primary factor affecting male fertility and a pathological condition that may lead to decreased sperm count and motility in patients. Many studies have shown that an imbalance of local antioxidant balance exists in patients with VC, leading to an obvious increase in the content of reactive oxygen species (ROS) and may cause reductive stress. Excessive ROS may aggravate spermatogenesis dysfunction and affect male fertility. Poly(ADP-ribose) polymerase (PARP) is an enzyme associated with DNA repair in eukaryotic cells, can be activated by DNA fragments with structural damage, and has been considered a DNA damage receptor in DNA damage repair and apoptosis. We built a rat model of VC and an oxidative damage model of a spermatocyte-derived cell line (GC-2 cells) induced by hydrogen peroxide to study the role of PARP1 in VC. Differentially expressed genes (DEGs) were obtained by RNA sequencing in the testes of VC rats. Analysis of DEGs revealed some genes with significantly altered expression, which were validated in rat and cell models. Immunofluorescence, real-time quantitative PCR analysis, Western blot, and flow cytometry were used to analyze the changes between the control group and the VC or hydrogen peroxide group. Overall, we found that PARP1 protein expression increased in VC rats and in the hydrogen peroxide-induced oxidative stress model of GC-2 cells. Parthanatos may be one of the factors leading to reduced reproductive capacity in VC patients. Our study provides novel insights into the mechanisms of male infertility induced by oxidative stress and provides a new therapeutic target for VC.

Reactive Oxygen Species and Their Consequences on the Structure and Function of Mammalian Spermatozoa

Significance: Among the 200 or so cell types that comprise mammals, spermatozoa have an ambiguous relationship with the reactive oxygen species (ROS) inherent in the consumption of oxygen that supports aerobic metabolism. Recent Advances: In this review, we shall see that spermatozoa need the action of ROS to reach their structural and functional maturity, but that due to intrinsic unique characteristics, they are, perhaps more than any other cell type, susceptible to oxidative damage. Recent studies have improved our knowledge of how oxidative damage affects sperm structures and functions. The focus of this review will be on how genetic and epigenetic oxidative alterations to spermatozoa can have dramatic unintended consequences in terms of both the support and the suppression of sperm function. Critical Issues: Oxidative stress can have dramatic consequences not only for the spermatozoon itself, but also, and above all, on its primary objective, which is to carry out fertilization and to ensure, in part, that the embryonic development program should lead to a healthy progeny. Future Directions: Sperm oxidative DNA damage largely affects the integrity of the paternal genetic material to such an extent that the oocyte may have difficulties in correcting it. Diagnostic and therapeutic actions should be considered more systematically, especially in men with difficulties to conceive. Research is underway to determine whether the epigenetic information carried by spermatozoa is also subject to changes mediated by pro-oxidative situations. Antioxid. Redox Signal. 37, 481-500.

Contemporary Use of ICSI and Epigenetic Risks to Future Generations

Since the birth of Louise Brown in 1978 via IVF, reproductive specialists have acquired enormous knowledge and refined several procedures, which are nowadays applied in assisted reproductive technology (ART). One of the most critical steps in this practice is the fertilization process. In the early days of IVF, a remarkable concern was the unpleasant outcomes of failed fertilization, overtaken by introducing intracytoplasmic sperm injection (ICSI), delineating a real breakthrough in modern ART. ICSI became standard practice and was soon used as the most common method to fertilize oocytes. It has been used for severe male factor infertility and non-male factors, such as unexplained infertility or advanced maternal age, without robust scientific evidence. However, applying ICSI blindly is not free of potential detrimental consequences since novel studies report possible health consequences to offspring. DNA methylation and epigenetic alterations in sperm cells of infertile men might help explain some of the adverse effects reported in ICSI studies on reproductive health in future generations. Collected data concerning the health of ICSI children over the past thirty years seems to support the notion that there might be an increased risk of epigenetic disorders, congenital malformations, chromosomal alterations, and subfertility in babies born following ICSI compared to naturally conceived children. However, it is still to be elucidated to what level these data are associated with the cause of infertility or the ICSI technique. This review provides an overview of epigenetic mechanisms and possible imprinting alterations following the use of ART, in particular ICSI. It also highlights the sperm contribution to embryo epigenetic regulation and the risks of in vitro culture conditions on epigenetic dysregulation. Lastly, it summarizes the literature concerning the possible epigenetic disorders in children born after ART.

The Management of Clinical Varicocele: Robotic Surgery Approach

Varicocele is a pathologic dilation of the testicular veins within the spermatic cord. Varicocele is considered the most common problem in reproductive medicine practice. It is identified in 15% of healthy men and up to 35% of men with primary infertility. The exact pathophysiology of varicoceles is not very well understood, and several theories have been proposed to explain it. Varicocele can impair sperm quality and fertility via various mechanisms: reflux of adrenal metabolites, increased testicular hypoxia, oxidative stress, and increased testicular temperature have been proposed. Several studies have reported the significant benefits on semen parameters with the surgical treatment of varicocele: reducing oxidatively induced sperm DNA damage and potentially improving fertility. Varicocele repair should be offered as a part of treatment option for male partners of infertile couples presenting with palpable varicoceles. Nowadays, there are several surgical approaches available for the treatment of varicocele, such as the retroperitoneal approach, inguinal approach, and the subinguinal approach. The subinguinal microscopic approach offers the best outcomes, such as shorter hospital stays, preservation of the testicular arteries and lymphatics, least number of postoperative complications, recurrence, and a higher number of pregnancies. Currently robotic-assisted laparoscopic surgery is widely adopted in urology and surgeons began to explore the potential applications of the robotic platform to male infertility microsurgical operations. Robotic approach offers many advantages: elimination of tremor, retraction with third arm, high quality, 3-dimensional visualization and surgeon ergonomics, all contributing to the precision of surgery.

Evaluation of oxidative stress in seminal plasma of adolescents with varicocele

Varicocele, defined by a dilation of efferent testicular veins, is the most commonly identifiable, surgically correctable lesion associated with male-factor infertility, starts at puberty and causes a progressive decline in fertility potential. The pathophysiology of infertility caused by this disease is still poorly understood, but it is suggested that the main mechanism is oxidative stress. Therefore, the aim of this study was to verify if the varicocele is associated with changes in enzymatic antioxidant mechanisms and seminal plasma lipid peroxidation levels in adolescents. We recruited 90 adolescents that were divided into control (C; n  = 27); varicocele and normal semen (VNS; n  =46); varicocele and altered semen (VAS; n  =17). Seminal and serum levels of lipid peroxidation were quantified by thiobarbituric acid reactive substances (TBARS). Seminal plasma antioxidant profile was evaluated by the activities of catalase (CAT), glutathione peroxidase (GPx) and superoxide dismutase (SOD). The VAS group had increased lipid peroxidation levels when compared to the other groups. The levels of serum lipid peroxidation and activities of the enzymes SOD and GPx did not differ between groups. CAT was undetectable by the method used. In conclusion, in adolescents with varicocele and altered semen analysis, there is an increase in seminal lipid peroxidation levels compared to adolescents with varicocele and without seminal change and adolescents without evident varicocele. However, the observed oxidative stress is not caused by a decrease in superoxide dismutase and glutathione peroxidase activities, which did not differ between adolescents with and without evident varicocele.

Lay summary

Varicocele, defined by a dilation of efferent testicular veins, is the most commonly identifiable, surgically correctable lesion associated with male-factor infertility, starts at puberty and causes a progressive decline in fertile potential. There is still much that is not understood regarding how exactly it affects semen quality, but most studies agree that oxidative stress, which is defined as excessive amounts of free radicals in relation to antioxidant defense, is an important mechanism. In this study, we aimed to verify if the varicocele is associated with changes in antioxidant defense and semen oxidation in 90 adolescents with and without varicocele. In adolescents with varicocele and abnormal semen, there is an increase in semen oxidation compared to controls or to the group with varicocele and normal semen quality. Our results can help to understand how varicocele leads to infertility in adolescents, identifying changes in oxidative activity in semen, since the onset of varicocele and before damage to sperm production can be detected.

Comprehensive Analysis of Global Research on Human Varicocele: A Scientometric Approach

Purpose

This study provides a comprehensive analysis of research trends on the etiology, mechanisms, potential risk factors, diagnosis, prognosis, surgical and non-surgical treatment of varicocele, and clinical outcomes before and after varicocele repair.

Materials and Methods

Varicocele studies published between 1988 and 2020 were retrieved from the Scopus database on April 5, 2021. Original studies on human varicocele were included, irrespective of language. Retrieved articles were manually screened for inclusion in various sub-categories. Bibliometric data was subjected to scientometric analysis using descriptive statistics. Network, heat and geographic mapping were generated using relevant software.

Results

In total, 1,943 original human studies on varicocele were published. These were predominantly from the northern hemisphere and developed countries, and published in journals from the United States and Germany. Network map analysis for countries showed several interconnected nodal points, with the USA being the largest, and Agarwal A. from Cleveland Clinic, USA, being a center point of worldwide varicocele research collaborations. Studies of adolescents were underrepresented compared with studies of adults. Studies on diagnostic and prognostic aspects of varicocele were more numerous than studies on varicocele prevalence, mechanistic studies and studies focusing on etiological and risk factors. Varicocele surgery was more investigated than non-surgical approaches. To evaluate the impact of varicocele and its treatment, researchers mainly analyzed basic semen parameters, although markers of seminal oxidative stress are being increasingly investigated in the last decade, while reproductive outcomes such as live birth rate were under-reported in the literature.

Conclusions

This study analyzes the publication trends in original research on human varicocele spanning over the last three decades. Our analysis emphasizes areas for further exploration to better understand varicocele’s impact on men’s health and male fertility.

Different group of non-obstructive intermittent azoospermias among non-obstructive azoospermia patients: A ten-year retrospective cohort study with control group

We have identified patients among non-obstructive azoospermia (NOA) cases in whom spermatozoa could not be detected despite treatment, but intermittent ejaculatory spermatozoon was found in their follow-up. NOA was observed in the retrospective screening at a rate of 15.35% among infertile men (n = 1976/12,871), while non-obstructive intermittent azoospermia (NO-IA) was detected at a rate of 6.8% among NO-IA (n = 135/1976) and 1.1% among all infertile men (n = 135/12,871). Spermatozoon was identified in the form of cryptospermia or extreme oligospermia in 58.13 (13.6-92.3) weeks on average in n = 55/135 patients among NO-IA. Pregnancy and live birth were achieved at a rate of 43.6% (n = 24/55) and 29% (n = 16/55), respectively, in intracytoplasmic sperm injection. NO-IA was composed of a group with no genetic pathological diagnosis, with lower follicle-stimulating hormone, lutenizing hormone and clinical varicocele rates compared with those of NOA (<0.05) and higher testicular volumes and pathological scores (<0.05). A major activity was observed in total testosterone, lutenizing hormone, testicular volumes and the logistic regression of pathological scores (<0.05).

Varicocele-Associated Infertility and the Role of Oxidative Stress on Sperm DNA Fragmentation

Varicocele has been extensively described and studied as the most important reversible cause of male infertility. Its impact on semen parameters, pregnancy rates, and assisted reproductive outcomes have been associated with multifactorial aspects, most of them converging to increase of reactive oxygen species (ROS). More recently, sperm DNA fragmentation has gained significant attention and potential clinical use, although the body of evidence still needs further evolution. The associations between sperm DNA damage and a variety of disorders, including varicocele itself, share common pathways to ROS increase. This mini-review discusses different aspects related to the etiology of ROS and its relation to varicocele and potential mechanisms of DNA damage.

Oxidative Stress: A Comprehensive Review of Biochemical, Molecular, and Genetic Aspects in the Pathogenesis and Management of Varicocele

Oxidative stress is a condition due to an imbalance between the concentrations of oxidants and antioxidants, and it is a well-recognized contributor in several male infertility conditions. Varicocele, a common vascular condition, may cause male infertility due to hyperthermia, hypoxia and/or exposure to toxic adrenal and renal metabolites. In this review, the mechanisms by which oxidative stress can affect cellular integrity and functions are described, along with molecular markers of cellular oxidative damage, and the most commonly performed techniques for their detection in seminal fluid. Moreover, we focus on the role of oxidative stress in the pathophysiology of varicocele based on recently published evidence from omics based studies, such as proteomics and genomics. Finally, we discuss strategies for the management of oxidative stress and the clinical guidelines for testing oxidative stress-related sperm DNA fragmentation in this group of patients.

Microdissection testicular sperm extraction (micro-TESE) in men with infertility due to nonobstructive azoospermia: summary of current literature

PURPOSE

Nonobstructive azoospermia (NOA) is associated with intrinsic testicular defects that severely impair sperm production. Although NOA invariably leads to infertility, focal sperm production may exist in the testicles of affected patients, which can be retrieved and used for intracytoplasmic sperm injection (ICSI) to generate healthy offspring. However, geographic locations of testicular sperm producing-areas are uncertain, making microsurgical-guided sperm retrieval (microdissection testicular sperm extraction; micro-TESE) an attractive method to identify and retrieve sperm in patients with NOA due to spermatogenic failure. Given the widespread use of micro-TESE, its effectiveness in harvesting sperm and related potential complications need to be clarified.

METHODS

We queried PubMed/MEDLINE for studies published in English, from inception to May 2021, concerning the effect of micro-TESE on sperm retrieval rate (SRR), complication rate and ICSI pregnancy rate-using retrieved testicular sperm in subfertile couples where the male had NOA.

RESULTS

We found 116 articles, including 70 original papers, 32 review articles, and 14 systematic reviews. The evidence accounted for 4895 patients. Micro-TESE retrieved sperm in 46.6% of men with NOA, but SRRs varied considerably (18.4-70.8%) and were mainly related to the treated population characteristics. Concerning the general population of NOA patients who have not undergone previous sperm retrieval (naïve population), the SRR by micro-TESE was 46.8% (1833 of 3914 patients; range 20-70.8%; 28 studies). In studies reporting SR by micro-TESE for men who had failed percutaneous testicular sperm aspiration or non-microsurgical testicular sperm extraction, the SRR was 39.1% (127 of 325 patients; range 18.4-57.1%; 4 studies). Data on adverse events indicated that micro-TESE was associated with low (~ 3%) short-term postoperative complication rates. The fertilizing ability of testicular sperm retrieved by micro-TESE and used for ICSI was adequate (~ 57%), whereas clinical pregnancy and live birth were obtained in 39% and 24% of couples who had an embryo transfer, respectively. The health of the resulting children seems reassuring, but the evidence is limited. The procedure increases sperm retrieval success compared to non-microsurgical retrieval methods, particularly in men with Sertoli cell-only testicular histopathology.

CONCLUSION

We concluded that micro-TESE is an effective and safe method to retrieve sperm from men with NOA-related infertility, with potential advantages over non-microsurgical methods. Nevertheless, high-quality, head-to-head comparative randomized controlled trials by sperm retrieval method, focusing on SRR, live birth rate and assessing long-term adverse events and health of children conceived using testicular sperm from NOA patients are lacking. Therefore, further research is required to determine the full clinical implications of micro-TESE in male infertility treatment.

Using Data Mining to Assist in Predicting Reproductive Outcomes Following Varicocele Embolization

We carried out a retrospective analysis of infertile couple data using several methodologies and data analysis techniques, including the application of a novel data mining approach for analyzing varicocele treatment outcomes. The aim of this work was to characterize embolized varicocele patients by ascertaining the improvement of some of their clinical features, predicting the success of treatment via pregnancy outcomes, and identifying data patterns that can contribute to both ongoing varicocele research and the more effective management of patients treated for varicocele. We retrospectively surveyed the data of 293 consenting couples undergoing infertility treatment with male varicocele embolization over a 10-year period, and sperm samples were collected before and at 3, 6, and 12 months after varicocele embolization treatment and analyzed with World Health Organization parameters—varicocele severity grades were assessed with medical assessment and scrotal ultrasound, patient personal information (e.g., age, lifestyle, and embolization complications) was collected with clinical inquiries, and varicocele embolization success was measured through pregnancy outcomes. Varicocele embolization significantly improved sperm concentration, motility, and morphology mean values, as well as sperm chromatin integrity. Following this study, we can predict that a male patient without a high varicocele severity grade (with grade I or II) has a 70.83% chance of conceiving after embolization treatment if his partners’ age is between 24 and 33 with an accuracy of 70.59%. Furthermore, male patients successful in achieving pregnancy following embolization are mostly characterized by having a normal sperm progressive motility before treatment, a normal sperm concentration after treatment, a moderate to low varicocele severity grade, and not working in a putatively hazardous environment.

Effect of varicocelectomy on sperm deoxyribonucleic acid fragmentation rates in infertile men with clinical varicocele: a systematic review and meta-analysis

OBJECTIVE

To evaluate the effect of varicocelectomy on sperm deoxyribonucleic acid fragmentation (SDF) rates in infertile men with clinical varicocele.

DESIGN

Systematic review and meta-analysis.

SETTING

Not applicable.

PATIENT(S)

Infertile men with clinical varicocele subjected to varicocelectomy.

INTERVENTION(S)

Systematic search using PubMed/Medline, EMBASE, Cochrane's central database, Scielo, and Google Scholar to identify relevant studies published from inception until January 2021. We included studies comparing SDF rates before and after varicocelectomy in infertile men with clinical varicocele.

MAIN OUTCOME MEASURE(S)

The primary outcome was the difference between the SDF rates before and after varicocelectomy. A meta-analysis of weighted data using random-effects models was performed. Results were reported as weighted mean differences (WMD) with 95% confidence intervals (CIs). Subgroup analyses were performed on the basis of the SDF assay, varicocelectomy technique, preoperative SDF levels, varicocele grade, follow-up time, and study design.

RESULT(S)

Nineteen studies involving 1,070 patients provided SDF data. Varicocelectomy was associated with reduced postoperative SDF rates (WMD -7.23%; 95% CI: -8.86 to -5.59; I² = 91%). The treatment effect size was moderate (Cohen's d = 0.68; 95% CI: 0.77 to 0.60). The pooled results were consistent for studies using sperm chromatin structure assay, terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling, sperm chromatin dispersion test, and microsurgical varicocele repair. Subgroup analyses showed that the treatment effect was more pronounced in men with elevated vs. normal preoperative SDF levels, but the impact of varicocele grade remained equivocal. Meta-regression analysis demonstrated that SDF decreased after varicocelectomy as a function of preoperative SDF levels (coefficient: 0.23; 95% CI: 0.07 to 0.39).

CONCLUSION(S)

We concluded that pooled results from studies including infertile men with clinical varicocele indicated that varicocelectomy reduced the SDF rates. The treatment effect was greater in men with elevated (vs. normal) preoperative SDF levels. Further research is required to determine the full clinical implications of SDF reduction for these men.

Sperm DNA fragmentation testing: Summary evidence and clinical practice recommendations

We herein summarise the evidence concerning the impact of sperm DNA fragmentation in various clinical infertility scenarios and the advances on sperm DNA fragmentation tests. The collected evidence was used to formulate 41 recommendations. Of these, 13 recommendations concern technical aspects of sperm DNA fragmentation testing, including pre-analytical information, clinical thresholds and interpretation of results. The remaining 28 recommendations relate to indications for sperm DNA fragmentation testing and clinical management. Clinical scenarios like varicocele, unexplained infertility, idiopathic infertility, recurrent pregnancy loss, intrauterine insemination, in vitro fertilisation/intracytoplasmic sperm injection, fertility counselling for men with infertility risk factors and sperm cryopreservation have been contemplated. The bulk evidence supporting the recommendations has increased in recent years, but it is still of moderate to low quality. This guideline provides clinicians with advice on best practices in sperm DNA fragmentation testing. Also, recommendations are provided on possible management strategies to overcome infertility related to sperm DNA fragmentation, based on the best available evidence. Lastly, we identified gaps in knowledge and opportunities for research and elaborated a list of recommendations to stimulate further investigation.

COMBINED TREATMENT OF PATHOSOSPERMIA WITH ADJUVANT THERAPY WITH SPEROTON COM- PLEX IN PATIENTS WITH VARICOCELE

OBJECTIVE To evaluate the effectiveness of combined treatment of pathozoospermia in patients with varicocele by performing micro- surgical phlebectomy of varicose veins of the spermatic cord in combination with adjuvant therapy with the Speroton complex MATERIAL AND METHODS Twenty microsurgical phlebectomies of varicose veins of the spermatic cord were performed in patients with pathozoo- spermia (oligoasthenospermia) against the background of varicocele with the appointment of the Speroton complex in the postoperative period for 3 months with an assessment of spermogram parameters before and after the operation in comparison with a group of 20 men with pathozocelemia without the use of adjuvant therapy. The study of morphological and functional parameters of spermogram of men of reproductive age (18-49 years) without signs of immune infertility (MAR-test IgG <10%) before and after the start of treatment was carried out. The average age of men was 33 ± 2.3 years (M ± m). RESULTS All patients with infertility in combination with varicocele had oligoasthenozoospermia before treatment. Three months after the start of treatment in the study groups, there was a statistically significant improvement in sperm counts due to an increase in the concentration of spermatozoa in 1 ml of ejaculate, an increase in the number of progressively mobile forms and total motility of spermatozoa by 50-68%, an increase in the number of live sperm by 19-20% and a decrease in the num- ber of dead forms of spermatozoa by 30-35%. A statistically significant decrease in the DNA fragmentation index by 34-52% (p <0.05) was found in all study groups. It was found that combination therapy, including microsurgical phlebectomy of the spermatic cord veins using the Speroton complex for 3 months, statistically significantly led to an increase in the concentration of spermatozoa in 1 ml of ejaculate (38.6 [38.2; 69.4]), an increase in progressively mobile forms (49.2 [26.7; 47.2]%) and general motility (72.2 [35.3; 64.7]%) of spermatozoa and viable forms (67.8 [39.3; 81.7] %), a decrease in the DNA fragmenta- tion index compared with the spermogram indicators of patients who underwent only microsurgical phlebectomy (p <0.05 for all study indicators). In the group of patients after combined treatment with the inclusion of adjuvant therapy of the Speroton complex, there was a statistically significant decrease in the sperm DNA fragmentation index to almost normal values (12.1 ± 1.1%) compared with the group of patients who underwent only surgery (17.2 ± 0.8%) (p = 0.01). Combined treatment (micro- surgical phlebectomy of the veins of the spermatic cord in combination with adjuvant therapy Speroton) of pathozoospermia in men of reproductive age with infertility on the background of varicocele can significantly improve the morphofunctional parameters of spermogram after 3 months from the start of treatment compared to men who underwent only surgical correction of varicocele.

Varicocoele and oxidative stress: New perspectives from animal and human studies

BACKGROUND

Varicocoele (VCL), one of the main causes of male subfertility, negatively affects testicular function. Due to limited access to human testicular tissue, animal model studies have been used to evaluate molecular and, recently, epigenetic changes attributed to pathophysiology induced by VCL.

OBJECTIVES

This review aims to provide an update on the latest findings regarding the link between VCL-induced biochemical stress and molecular changes in germ cells and spermatozoa. Endocrine and antioxidant status, testicular chaperone-specific hemostasis failure, altered testicular ion balance, metabolic disorders, and altered carbon cycling during spermatogenesis are among the many features that will be presented.

DISCUSSION

Literature review coupled with our own findings suggests that ionic imbalance, hypoxia, hyperthermia, and altered blood flow could lead to severe chronic oxidative and nitrosative stress in patients with VCL leading to defective spermatogenesis and impairment of the integrity of all sperm cell components and compartments down to the epigenetic information they carry.

CONCLUSION

Since oxidative stress is an important feature of the reproductive pathology of VCL, therapeutic strategies such as the administration of appropriate antioxidants could be undertaken as a complementary non-invasive treatment line.

Effects of Primary Varicocele and Related Surgery in Male Infertility: A Meta-Analysis

Purpose: To investigate the effect of primary varicocele and related surgery in male infertility through meta-analysis.

Methods: A systematic search of the literature was conducted using the Medline, Embase, Cochrane, and CNKI databases. The search was up to September 2019. Article selection proceeded according to the search strategy based on Preferred Reporting Items for Systematic Reviews and Meta-analyses criteria. Data were analyzed using RevMan 5.2. A random-effects model was used to calculate the overall combined risk estimates.

Results: After screening 687 articles, 4 randomized controlled trials with 349 patients were included. One hundred seventy two patients were addressed in embolization/ligation, with 177 patient's observation treatment. The number of spontaneous pregnancies in the two groups was 41 and 40, respectively. There was no significant difference in pregnancy rate between the operation group and the control group. RR = 1.05 [0.72, 1.54].

Conclusion: There is not enough evidence to explain the surgical treatment of varicocele can improve the natural fertility of the infertile couples, and there is still a need for most of prospective randomized controlled trials to verify the efficacy of varicocele surgery for treating of male infertility. We do not deny the importance of this operation, we just want to call on everyone to strictly grasp the indications of the operation, avoid ineffective medical expenses, and avoid unnecessary pain to patients.

The effect of varicocele repair for sperm DNA fragmentation: A protocol for systematic review and meta-analysis

INTRODUCTION

Sperm DNA integrity has been considered as one of the important determinants of normal fertilization and embryonic development in natural and assisted pregnancy. It is difficult for men with high levels of sperm DNA fragmentation (SDF) in semen to conceive their partners naturally and assist in conception. The studies have found that the level of SDF in the semen of patients with varicocele (VC) was on the high side. In recent years, the effect of VC surgery on DNA fragmentation index has attracted the attention of researchers. In this study, we will evaluate the effectiveness of VC repair as a way to alleviate SDF and improve male fertility.

METHODS AND ANALYSIS

Electronic databases including English databases (PubMed, MEDLINE, EMBASE, Web of Science, Cochrane Library) and Chinese databases (China National Knowledge Infrastructure, China Biology Medicine Database, Wanfang Database, VIP Database) will be searched from their inception to December 2020 to recognize related studies. All the randomized controlled trials of microsurgical varicocelectomy for the management of VC patients will be included. The potential outcome will include improvement in SDF, oxidative stress markers (reactive oxygen species, nitric oxide, and lipid peroxidation products), sperm chromatin compaction, other advanced sperm function characteristics, follow-up of fertility results. We will conduct this study strictly according to the Cochrane Handbook for Systematic Reviews of Interventions.

RESULTS

The study is a protocol for systematic review and meta-analysis without results, and data analysis will be carried out after the protocol. We will share our findings on April 5th of 2021.

CONCLUSION

This systematic review will provide more evidence to assess whether varicocelectomy is an effective intervention for patients with SDF. The results will be published in a public issue journal and offer the urologists help to make clinical decisions.

ETHICS AND DISSEMINATION

Formal ethical approval is not required in this protocol. We will collect and analyze data based on published research. Since this research does not involve patients, personal privacy will not be affected. The results of this review will be distributed to peer-reviewed journals or submitted to relevant conferences.

PROTOCOL REGISTRATION NUMBER

INPLASY202070119.

Ameliorating Effects of Natural Antioxidant Compounds on Female Infertility: a Review

The prevalence of female infertility cases has been increasing at a frightening rate, affecting approximately 48 million women across the world. However, oxidative stress has been recognized as one of the main mediators of female infertility by causing various reproductive pathologies in females such as endometriosis, PCOS, preeclampsia, spontaneous abortion, and unexplained infertility. Nowadays, concerned women prefer dietary supplements with antioxidant properties over synthetic drugs as a natural way to lessen the oxidative stress and enhance their fertility. Therefore, the current review is an attempt to explore the efficacy of various natural antioxidant compounds including vitamins, carotenoids, and plant polyphenols and also of some medicinal plants in improving the fertility status of females. Our summarization of recent findings in the current article would pave the way toward the development of new possible antioxidant therapy to treat infertility in females. Natural antioxidant compounds found in fruits, vegetables, and other dietary sources, alone or in combination with other antioxidants, were found to be effective in ameliorating the oxidative stress-mediated infertility problems in both natural and assisted reproductive settings. Numerous medicinal plants showed promising results in averting the various reproductive disorders associated with female infertility, suggesting a plant-based herbal medicine to treat infertility. Although optimum levels of natural antioxidants have shown favorable results, however, their excessive intake may have adverse health impacts. Therefore, larger well-designed, dose-response studies in humans are further warranted to incorporate natural antioxidant compounds into the clinical management of female infertility.

Increased Sperm DNA Fragmentation in Infertile Men with Varicocele: Relationship with Apoptosis, Seminal Oxidative Stress, and Spermatic Parameters

This study intends to determine the extent of nuclear sperm injury in patients with varicocele and to investigate its relationship with apoptosis and oxidative stress (OS). Ejaculated sperm samples from 51 patients diagnosed with varicocele and 29 fertile men were examined. According to the guidelines, the patient's sperm samples were classified into varicocele with normal semen parameters (n = 11) and varicocele with abnormal semen parameters (n = 40). Sperm DNA fragmentation was assessed using terminal deoxynucleotidyl transferase dUTP nick end labeling assay. The proportion of both viable and dead spermatozoa with externalized phosphatidylserine (PS) was detected by the bivariate annexin V/6-CFDA staining method. Seminal malondialdehyde (MDA) amounts and antioxidant enzymes activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) were measured spectrophotometrically. Sperm DNA fragmentation, viable spermatozoa with externalized PS, and MDA levels were significantly higher in studied subgroups of patients with varicocele, either with normal or with abnormal semen parameters than controls. The seminal antioxidant enzymes activities were significantly reduced in both subgroups of patients with varicocele compared to the controls. The percentage of spermatozoa with fragmented DNA was positively correlated to the MDA level as well as the proportion of viable spermatozoa with externalized PS. However, the decreased seminal antioxidant status was negatively correlated with the increased proportion of sperm DNA fragmentation and apoptotic spermatozoa. Impaired seminal antioxidant profile and increased seminal level of lipid peroxidation may be involved in the pathophysiological mechanisms of cell death-mediated DNA breaks in patients with varicocele.

Scientific landscape of oxidative stress in male reproductive research: A scientometric study

Unraveling the role of reactive oxygen species and associated oxidative stress (OS) in male reproduction is one of the key areas of male reproductive research. This article illustrates the scientific landscape of OS in male reproductive research over the past several decades (1941-2018) using a scientometric approach. Scientometric data (articles per year, authors, affiliations, journals, and countries) on OS related to male reproduction were retrieved from the Scopus database and analyzed for each decade. Our analysis revealed an increasing trend in OS-based male reproductive research from 1941 to 2018 with a steep raise in publications and research collaborations starting from the period 1991-2000 (R² = 0.81). Semen abnormalities and varicocele were the major areas investigated in relation to OS with the highest positive trend in publications from the time interval 1981-1990 to 2011-2018. Analysis of publications based on OS assessment techniques revealed chemiluminescence (n = 180) and evaluation of antioxidants (n = 300) as the most widely used direct and indirect tests, respectively. Furthermore, prognostic/diagnostic studies on OS evaluation increased significantly over the time. Our analysis highlights the evolution of OS in male reproductive research and its emergence as an important prognostic and diagnostic tool in the evaluation of male infertility.

Endoplasmic Reticulum Stress (ER Stress) and Unfolded Protein Response (UPR) Occur in a Rat Varicocele Testis Model

Using a surgically induced varicocele rat model, we show here strong evidence that the misfolded/unfolded protein response that is part of the stress response of the endoplasmic reticulum (ER) is activated in the varicocele testis (VCL), leading to the induction of apoptosis. To support this hypothesis, it is observed that the spliced variant of the X-box protein 1 (XBP1s), resulting from the activation of the inositol-requiring enzyme 1 (IRE1) membrane sensor, is significantly more represented in VCL testicular extracts. The activation of the IRE1/XBP1s pathway is also supported by the observation that the VCL testes show an increase phosphorylation of the c-Jun-kinase (JNK) known to be one intermediate of this pathway and an increased level of caspase-3, the terminal apoptotic effector, partly explaining the apoptotic status of the VCL testis.

Differential DNA methylation pattern and sperm quality in men with varicocele

OBJECTIVE

To study the global DNA methylation pattern in spermatozoa of patients with varicocele as well as investigate their semen quality.

DESIGN

Prospective observational case-control study.

SETTING

University-affiliated hospital.

PATIENT(S)

A total of 26 men with varicocele and 26 fertile men without the disorder.

INTERVENTIONS

Analysis of semen quality and sperm DNA methylation patterns.

MAIN OUTCOME MEASURE(S)

Semen quality evaluated by semen analysis, and sperm DNA methylation patterns investigated using the Infinium MethylationEPIC BeadChip platform.

RESULT(S)

Men with varicocele displayed decreased semen quality. The sperm DNA methylation analysis showed that men with varicocele exhibit global hypomethylation in comparison with the control group. A total of 59 differentially methylated CpG sites were identified, most of them hypomethylated in the varicocele group. In regional analyses, 1,695 DNA regions were differentially methylated in men with varicocele. These regions show associations with gamete generation, meiotic and meiosis cell cycle, and semen quality based on gene ontology analysis.

CONCLUSION(S)

Gene ontology results suggest that changes in methylation may be associated with the low semen quality phenotype observed in some varicocele patients because the observed differentially methylated regions in varicocele patients are related to male reproductive pathways. Additionally, the varicocele grade may influence the magnitude of global sperm DNA methylation change. To our knowledge, this is the first report analyzing changes at a regional or CpG-specific level in men with varicocele.

Conventional semen analysis and advanced sperm function tests in diagnosis and management of varicocele

Clinical varicoceles are a common cause of male infertility and affect sperm parameters as measured in a conventional semen analysis. Varicocelectomy has been shown in prospective studies to improve semen parameters in men with a clinical varicocele. Clinical varicoceles are also a well-known source of oxidative stress which may affect the quality of spermatozoa. Spermatozoa are particularly susceptible to oxidative stress due to a limited capacity for DNA repair. The susceptibility of spermatozoa to oxidative stress is modulated by a balance between ROS and antioxidants, which can be quantified by various laboratory assays. Varicocelectomy has been consistently shown to reduce both ROS and sperm DNA fragmentation, and various assays should be utilised in the diagnosis and treatment of infertile men with a clinical varicocele.

Sertoli Cell Alterations in Peripubertal Varicocelized Rats: Evidence of Primary Damage on Spermatogenesis

Idiopathic varicocele is closely associated with male infertility or subfertility. Sertoli cell is a very important regulator of spermatogenesis. We investigated the morphofunctional alterations in the Sertoli cell and its possible involvement in the establishment of testicular primary lesion in experimental left-sided varicocele, induced from peripuberty. Twenty-five male peripubertal rats (44 days postpartum [dpp]) were distributed into two groups: control (C) and varicocele (V). Experimental left varicocele was induced in rats through the partial ligature of the left renal vein. Euthanasia was performed at 100 dpp. Testicular histopathology and testosterone plasmatic level were evaluated. Transferrin and vimentin proteins were, respectively, used as immunomarkers of Sertoli cell function and structure. Significant reductions in vimentin and transferrin expressions were noticed in androgen-dependent stages (VII and VIII) of the seminiferous epithelium cycle in V rats; testosterone plasmatic level was also reduced. Bilateral testicular histopathological alterations were found in V rats, mainly massive germ cell desquamation. The histological damage and changes in protein expressions occurred bilaterally. The relevant impairment of the functional and structural characteristics of the Sertoli cell, together with the typical massive germ cell desquamation, indicates that Sertoli cell changes can primarily contribute to the significant testicular dysfunction associated with varicocele.

Oxidative stress and male infertility: current knowledge of pathophysiology and role of antioxidant therapy in disease management

Infertility is a global health problem involving about 15% of couples. Approximately half of the infertility cases are related to male factors. The oxidative stress, which refers to an imbalance in levels of reactive oxygen species (ROS) and antioxidants, is one of the main causes of infertility in men. A small amount of ROS is necessary for the physiological function of sperm including the capacitation, hyperactivation and acrosomal reaction. However, high levels of ROS can cause infertility through not only by lipid peroxidation or DNA damage but inactivation of enzymes and oxidation of proteins in spermatozoa. Oxidative stress (OS) is mainly caused by factors associated with lifestyle. Besides, immature spermatozoa, inflammatory factors, genetic mutations and altering levels of sex hormones are other main source of ROS. Since OS occurs due to the lack of antioxidants and its side effects in semen, lifestyle changes and antioxidant regimens can be helpful therapeutic approaches to overcome this problem. The present study aimed to describe physiological ROS production, roles of genetic and epigenetic factors on the OS and male infertility with various mechanisms such as lipid peroxidation, DNA damage, and disorder of male hormone profile, inflammation, and varicocele. Finally, the roles of oral antioxidants and herbs were explained in coping with OS in male infertility.

The ameliorative effect of monotropein, astragalin, and spiraeoside on oxidative stress, endoplasmic reticulum stress, and mitochondrial signaling pathway in varicocelized rats

Background

Monotropein, astragalin, and spiraeoside (MAS) are active compounds extracted from medicinal herbs; monotropein from Morinda officinalis How (Rubiaceae), astragalin (kaempferol 3-O-glucoside) from Cuscuta chinensis Lamark (Convolvulaceae) and spiraeoside from the outer scales of Allium cepa L. (Liliceae) in a ratio of 6.69:0.41:3.61. Monotropein, astragalin, and spiraeoside are well-known antioxidants, anti-inflammatory, and antinociceptive agents. The current investigation aims to study the molecular mechanism of varicocele-induced male infertility and the underlying pharmacological mechanisms of MAS.

Methods

Four groups were included: control (CTR), MAS 200 group (MAS 200 mg/kg), varicocele group (VC), and VC + MAS 200 group (MAS 200 mg/kg). Sprague-Dawley (SD) rats were treated with 200 mg/kg MAS or vehicle once daily for 28 days. The possible signaling mechanism and effects of MAS were measured via histological staining, immunohistochemistry, western blot, and biochemical assays.

Results

Parameters such as sperm motility and count, Johnsen’s scores, spermatogenic cell density, serum testosterone, testicular superoxide dismutase (SOD), catalase, glutathione peroxidase (GPx) and expression of the steroidogenic acute regulatory protein (StAR) improved significantly in the VC + MAS 200 group compared with the VC group. MAS treatment of varicocele-induced group significantly decreased the levels of serum luteinizing hormone (LH) and follicle-stimulating hormone (FSH), as well as testicular interleukin-6 (IL6), tumor necrosis factor-α (TNF-α), ROS/RNS, and malondialdehyde (MDA). It also decreased the apoptotic index and reduced the expression of endoplasmic reticulum (ER) protein levels (Grp78, p-IRE1α, and p-JNK) and apoptotic markers such as cleaved caspase-3 and Bax/Bcl2 ratio.

Conclusion

This study suggests that the crosstalk between oxidative stress, ER stress, and mitochondrial pathway mediates varicocele-induced testicular germ cell apoptosis. MAS promotes spermatogenesis in varicocele-induced SD rat, probably by decreasing cytokines (IL-6, TNF-α) levels, regulating abnormal sex hormones, and decreasing oxidative stress, ER stress, and apoptosis.

Seminal SIRT1-oxidative stress relationship in infertile oligoasthenoteratozoospermic men with varicocele after its surgical repair

This work assessed seminal SIRT1-oxidative stress (OS) relationship in infertile oligoasthenoteratozoospermic (OAT) men after varicocele repair. Overall, thirty OAT men with varicocele were investigated. Inclusion criteria were infertile males (males who were unable to initiate a pregnancy within 1 year of regular unprotected intercourse), confirmed OAT and normal female factor. These cases were subjected to history taking, clinical checkup and semen analysis. In their semen, seminal SIRT1, malondialdehyde (MDA) and glutathione peroxidase (GPx) levels were assessed. These men were subjected to varicocele surgical repair and were followed up for 3 months. Post-operatively, the mean seminal SIRT1, GPx levels showed significant increases and the mean MDA level showed significant decrease compared to the pre-operative levels linked to improved sperm parameters. The mean seminal SIRT1, GPx, MDA levels showed more significant improvement in grade III varicocele cases compared to grade II cases after surgical repair. Seminal SIRT1 levels showed significant positive correlations with sperm concentration, sperm motility, sperm normal morphology, seminal GPx levels and a significant negative correlation with seminal MDA levels. It could be concluded that seminal SIRT1 is significantly decreased in infertile OAT men with varicocele after its surgical repair linked to improved sperm parameters as well as seminal OS.

Interventions to Prevent Sperm DNA Damage Effects on Reproduction

Excessive oxidation and antioxidant imbalance resulting from several conditions may cause sperm DNA damage, which, in turn, affect male fertility, both natural and assisted. Sperm DNA damage transferred to the embryo might also affect the health of offspring. Several conditions associated with excessive oxidative stress are modifiable by the use of specific treatments, lifestyle changes, and averting exposure to environmental/occupational toxicants. Here, we discuss the strategies to reduce sperm DNA damage with a focus on clinical and surgical interventions.

Intracytoplasmic sperm injection for male infertility and consequences for offspring

Intracytoplasmic sperm injection (ICSI) has become the most commonly used method of fertilization in assisted reproductive technology. The primary reasons for its popularity stem from its effectiveness, the standardization of the procedure, which means that it can easily be incorporated into the routine practice of fertility centres worldwide, and the fact that it can be used to treat virtually all forms of infertility. ICSI is the clear method of choice for overcoming untreatable severe male factor infertility, but its (over)use in other male and non-male factor infertility scenarios is not evidence-based. Despite all efforts to increase ICSI efficacy and safety through the application of advanced sperm retrieval and cryopreservation techniques, as well as methods for selecting sperm with better chromatin integrity, the overall pregnancy rates from infertile men remain suboptimal. Treating the underlying male infertility factor before ICSI seems to be a promising way to improve ICSI outcomes, but data remain limited. Information regarding the health of ICSI offspring has accumulated over the past 25 years, and there are reasons for concern as risks of congenital malformations, epigenetic disorders, chromosomal abnormalities, subfertility, cancer, delayed psychological and neurological development, and impaired cardiometabolic profile have been observed to be greater in infants born as a result of ICSI than in naturally conceived children. However, as subfertility probably influences the risk estimates, it remains to be determined to what extent the observed adverse outcomes are related to parental factors or associated with ICSI.

Use of testicular sperm for intracytoplasmic sperm injection in men with high sperm DNA fragmentation: a SWOT analysis

Spermatozoa retrieved from the testis of men with high levels of sperm DNA fragmentation (SDF) in the neat semen tend to have better DNA quality. Given the negative impact of SDF on the outcomes of Assisted Reproductive Technology (ART), an increased interest has emerged about the use of testicular sperm for intracytoplasmic sperm injection (Testi-ICSI). In this article, we used a SWOT (strengths, weaknesses, opportunities, and threats) analysis to summarize the advantages and drawbacks of this intervention. The rationale of Testi-ICSI is bypass posttesticular DNA fragmentation caused by oxidative stress during sperm transit through the epididymis. Hence, oocyte fertilization by genomically intact testicular spermatozoa may be optimized, thus increasing the chances of creating a normal embryonic genome and the likelihood of achieving a live birth, as recently demonstrated in men with high SDF. However, there is still limited evidence as regards the clinical efficacy of Testi-ICSI, thus creating opportunities for further confirmatory clinical research as well as investigation of Testi-ICSI in clinical scenarios other than high SDF. Furthermore, Testi-ICSI can be compared to other laboratory preparation methods for deselecting sperm with damaged DNA. At present, the available literature supports the use of testicular sperm when performing ICSI in infertile couples whose male partners have posttesticular SDF. Due to inherent risks of sperm retrieval, Testi-ICSI should be offered when less invasive treatments for alleviating DNA damage have failed. A call for continuous monitoring is nonetheless required concerning the health of generated offspring and the potential complications of sperm retrieval.

Oxidative stress and sperm function: A systematic review on evaluation and management

Objective: To review and present the most distinct concepts on the association of reactive oxygen species (ROS) with male reproduction.

Methods: The Preferred Reporting Items for Systematic Reviews and Meta Analyses (PRISMA) guidelines were used to search PubMed, Medline, EMBASE, and the Cochrane electronic databases for studies investigating the role of oxidative stress (OS) on sperm function.

Results: The literature search yielded 1857 studies, of which 1791 articles were excluded because of irrelevance of data, non-English language, non-human nature or because they were case reports or commentaries. All included studies were reviews (46), meta-analyses (one), original research studies (18) and guideline articles (one). The studies were published between 1984 and 2018. Under normal physiological conditions, ROS are vital for sperm maturation, hyperactivation, capacitation, acrosome reaction, as well as fertilisation. However, a number of endogenous and exogenous causes may induce supra-physiological levels of ROS resulting in lipid peroxidation, sperm DNA fragmentation and apoptosis, and consequently infertility. Several laboratory testing methods can be used in infertile men to diagnose OS. Treatment usually involves antioxidant supplementation and, when possible, elimination of the causative factor.

Conclusion: OS is an important cause of male factor infertility. Its assessment provides essential information that can guide treatment strategies aimed at improving the male’s reproductive potential.

Abbreviations: bp: base-pair; CAT: catalase; LPO: lipid peroxidation; MDA: malondialdehyde; MiOXSYS: Male Infertility Oxidative System; mtDNA: mitochondrial DNA; NAD(PH): nicotinamide adenine dinucleotide (phosphate); NO: nitric oxide; 8-OHdG: 8-hydroxy-2’-deoxyguanosine; ORP: oxidation–reduction potential; OS: oxidative stress; PKA: protein kinase A; PLA2: phospholipase A2; PRISMA: Preferred Reporting Items for Systematic Reviews and Meta-Analyses; PUFA: poly-unsaturated fatty acid; ROS: reactive oxygen species; SOD: superoxide dismutase; TAC: total antioxidant capacity; TBA: thiobarbituric acid

Artificial Neural Network to Predict Varicocele Impact on Male Fertility through Testicular Endocannabinoid Gene Expression Profiles

The relationship between varicocele and fertility has always been a matter of debate because of the absence of predictive clinical indicators or molecular markers able to define the severity of this disease. Even though accumulated evidence demonstrated that the endocannabinoid system (ECS) plays a central role in male reproductive biology, particularly in the testicular compartment, to date no data point to a role for ECS in the etiopathogenesis of varicocele. Therefore, the present research has been designed to investigate the relationship between testicular ECS gene expression and fertility, using a validated animal model of experimental varicocele (VAR), taking advantage of traditional statistical approaches and artificial neural network (ANN). Experimental induction of VAR led to a clear reduction of spermatogenesis in left testes ranging from a mild (Johnsen score 7: 21%) to a severe (Johnsen score 4: 58%) damage of the germinal epithelium. However, the mean number of new-borns recorded after two sequential matings was quite variable and independent of the Johnsen score. While the gene expression of biosynthetic and degrading enzymes of AEA (NAPE-PLD and FAAH, respectively) and of 2-AG (DAGLα and MAGL, respectively), as well as their binding cannabinoid receptors (CB1 and CB2), did not change between testes and among groups, a significant downregulation of vanilloid (TRPV1) expression was recorded in left testes of VAR rats and positively correlated with animal fertility. Interestingly, an ANN trained by inserting the left and right testicular ECS gene expression profiles (inputs) was able to predict varicocele impact on male fertility in terms of mean number of new-borns delivered (outputs), with a very high accuracy (average prediction error of 1%). The present study provides unprecedented information on testicular ECS gene expression patterns during varicocele, by developing a freely available predictive ANN model that may open new perspectives in the diagnosis of varicocele-associated infertility.

Alpha-Lipoic Acid improves the testicular dysfunction in rats induced by varicocele

Alpha-lipoic acid (ALA) is a disulphide compound with multifunctional antioxidant properties and is soluble in both water and lipid. Several recent studies evaluated efficacy of ALA in various diseases related to oxidative damage such as diabetes, multiple sclerosis and Alzheimer and concluded that ALA can reduce oxidative stress by quenching reactive oxygen and nitrogen species, restoring antioxidants such as glutathione, vitamins C and E, and/or improving activity of antioxidant enzymes. Varicocele, an enlargement of the veins in scrotum, is considered as the most common repairable cause of male infertility and is associated with high levels of oxidative stress. In this study, surgical varicocele was induced in 30 adult male Wistar rats with other 20 rats serving as sham-operated and nonoperated control. Varicocele caused significant worsening of sperm parameters, DNA damage and lipid peroxidation 2 and 4 months after surgery. A 2-month ALA administration after surgery was able to revert these effects. These results clearly showed that ALA can reduce the negative side effects of elevated testicular temperature and increased oxidative stress in varicocelised rats. This study warrants future clinical research to assess whether ALA is of help in the treatment of infertile men with varicocele.