Increased nitric oxide is accompanied by lipid oxidation in adolescent varicocele

Oxidative Stress and Varicocele-Associated Male Infertility

Despite being regarded as one of the most common causes of male subfertility, the pathophysiology of varicocele remains largely unknown. Recently, oxidative stress (OS) is proposed to be the mediator in how varicocele may negatively impact fertility. The imbalance of reactive oxygen species (ROS) and seminal antioxidants results in damage to sperm DNA and lipid membrane. There is evidence demonstrating higher OS level in men with varicocele which is also positively correlated with clinical grading of varicocele. Moreover, a number of studies have revealed the negative correlation between OS and conventional semen parameters. Furthermore, various interventions have shown their potential in alleviating OS in men with varicocele-associated infertility. Although direct evidence on improving pregnancy rate is not available at the moment, varicocelectomy has demonstrated promising results in relieving OS. Oral antioxidants represent another option with a favourable safety profile. The supplement can be used alone or as adjunct to varicocelectomy. However, most of the studies are hampered by heterogenous dose regime and high-level evidence is lacking.

The Interaction of NO and H2S in Boar Spermatozoa under Oxidative Stress

Various recent studies dedicated to the role of nitric oxide (NO) and hydrogen sulfide (H2S) in somatic cells provide evidence for an interaction of the two gasotransmitters. In the case of male gametes, only the action of a single donor of each gasotransmitter has been investigated up until today. It has been demonstrated that, at low concentrations, both gasotransmitters alone exert a positive effect on sperm quality parameters. Moreover, the activity of gaseous cellular messengers may be affected by the presence of oxidative stress, an underlying condition of several male reproductive disorders. In this study, we explored the effect of the combination of two donors SNP and NaHS (NO and H2S donors, respectively) on boar spermatozoa under oxidative stress. We applied NaHS, SNP, and their combination (DD) at 100 nM concentration in boar spermatozoa samples treated with Fe2+/ascorbate system. After 90 min of incubation at 38 °C, we have observed that progressive motility (PMot) and plasma membrane integrity (PMI) were improved (p < 0.05) in DD treatment compared to the Ctr sample under oxidative stress (CtrOX). Moreover, the PMot of DD treatment was higher (p < 0.05) than that of NaHS. Similar to NaHS, SNP treatment did not overcome the PMot and PMI of CtrOX. In conclusion, for the first time, we provide evidence that the combination of SNP and NaHS surmounts the effect of single-donor application in terms of PMot and PMI in porcine spermatozoa under oxidative stress.

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.

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.

Berberine inhibits experimental varicocele-induced cell cycle arrest via regulating cyclin D1, cdk4 and p21 proteins expression in rat testicles

The aim of this study was to uncover the protective effect of berberine (BBR), an antioxidant chemical, on experimental varicocele (VCL)-induced adverse effects on cell cycle machinery during early germ cells mitosis. To follow-up this study, 30 mature male Wistar rats were divided into control-sham, nontreated VCL, 50 mg kg-1 and 100 mg kg-1 BBR-treated VCL groups. Following 60 days, histological alterations were analysed by haematoxylin and eosin (H and E) staining, and expressions of cyclin-D1, cyclin-dependent kinase-4 (cdk4) and p21 were investigated by immunohistochemical (IHC) staining technique. Finally, DNA ladder test was carried out to examine the testicular DNA fragmentation. Administration of BBR remarkably diminished the percentage of seminiferous tubules with deformed shape, depleted germ cells and germ cells dissociation compared to VCL-sole group. The IHC observations showed that BBR significantly (p < .05) reduced VCL-induced p21 expression increase and up-regulated cyclin-D1 and cdk4 expressions. Moreover, BBR decreased VCL-induced DNA fragmentation. In conclusion, BBR can promote cell cycle through cellular DNA content protection, p21 expression down-regulation and maintaining cyclin-D1 and cdk4 expressions. Thus, BBR could be considered as a novel protective biochemical agent against experimental VCL-induced derangements. However, more studies are needed to uncover BBR-induced effects on cells cycle process and germ cells development.

Perspectives in Pediatric Pathology, Chapter 20. Adolescent Varicocele

Varicocele is characterized by elongation, dilatation, and tortuosity of the veins draining the testis and its covers, causing circulatory reflux along the inner spermatic vein [ 1 ]. Varicocele results in progressive testicular lesions and, if untreated, can lead to testicular atrophy [ 2 ]. Varicocele is considered the most frequently identified cause of male infertility [ 3 ]. The mechanisms involved in varicocele formation are not well known and probably are multiple, differing from one patient to another.

Comparison of Before and After Varicocelectomy Levels of Trace Elements, Nitric Oxide, Asymmetric Dimethylarginine and Malondialdehyde in the Seminal Plasma and Peripheral and Spermatic Veins

Increased oxidative damage has been suggested to play an important role in the spermatogenesis and sperm function changes in patients with varicocele. However, changes in levels of nitric oxide (NO), asymmetric dimethylarginine (ADMA), malondialdehyde (MDA), iron (Fe), zinc (Zn) and copper (Cu) in blood and seminal plasma, and semen quality, are unknown. The aim of this study was to investigate the NO, ADMA, Fe, Cu, Zn and MDA levels from seminal plasma and peripheral and spermatic vein blood samples of patients with varicocele before and after varicocelectomy. In this before and after comparative study, 29 consecutive patients attending a training hospital in Tekirdag, Turkey, were recruited. MDA and NO levels were determined by spectrophotometric methods. The levels of ADMA were determined by enzyme-linked immunosorbent assay method. Trace element level was determined by atomic absorption spectrophotometric method. The levels of MDA in the seminal plasma and peripheral and spermatic vein samples were observed to decrease significantly in the comparison of before and after phases of the study group (p = 0.022, p = 0.001 and p = 0.034, respectively). Also, the levels of NO in the seminal plasma and spermatic vein samples decreased significantly in the comparison of before and after phases of the study group (p = 0.025 and p = 0.001, respectively), while the levels of ADMA in seminal plasma and spermatic vein samples increased significantly in the comparison of before and after phases of the study group (p = 0.003 and p = 0.001, respectively). There were no significant differences in the levels of trace elements and sperm count (p > 0.05). Oxidative stress is significantly higher in the spermatic vein and seminal plasma samples of patients with varicocele before varicocelectomy. In conclusion, these events may be evaluated accordingly for the potentially beneficial treatment methods.

Varicocele-Induced Infertility in Animal Models

Varicocele is characterized by abnormal tortuosity and dilation of the veins of the pampiniform plexus within the spermatic cord. Although several reports show the mechanisms by which the varicocele exerts its infertility impact, the exact pathophysiology for varicocele-induced inflammation and its relationship with testicular endocrine disruption remain largely unknown. This review article will update previous findings by discussing the pathophysiology of long term-induced varicocele in rats. Testicular endocrine disruption in experimentally-induced varicocele, new findings related to biochemical alterations in germinal epithelium, and sperm cells apoptosis are highlighted. Recent observations show that varicocele down-regulates first and second maturation divisions, results in Leydig and Sertoli cell inflammation, and increases immune cell infiltration in the testes of the rat as an animal model. Ultimately, previous findings of our laboratory have revealed that varicocele decreased sperm motility, viability and severe DNA damage. Damage in sperm significantly lowers the animal’s fertility potential. Varicocele not only exerts its pathologic impact by lowering the testicular antioxidant capacity but it also down-regulates first and second maturation divisions by exerting biochemical alterations such as reducing the intracytoplasmic carbohydrate ratio in germinal epithelium.

Outcome of Varicocelectomy with Different Degrees of Clinical Varicocele in Infertile Male

Aim. To evaluate the prevalence and effect of varicocele repair on sperm motility, sperm concentration, testicular volume, and pregnancy rate in different degrees of clinical varicocele. Material and Methods. The case records were retrospectively evaluated for 482 infertile patients with varicocele who underwent varicocelectomy from December 2008 to December 2013. Semen analysis of patient at preoperative and 3-, 6-, and 12-month postoperative period was done. Varicocele was graded as per the World Health Organization grading (WHO 1993) system and included in the study. Testicular volume was noted by ultrasonography in pre- and postoperative period in one-year follow-up. Pregnancy rate was calculated at 3, 6, and 12 months of follow-up. Results. Significant differences were seen in sperm motility and concentration of patients with Grade 3 varicocele as compared with Grade 1 and Grade 2 varicocele. Significant increase in testicular volume was present after one year in Grade 3 varicocele in the postoperative period. There was significant correlation between the testicular volume and the sperm concentration. Percentage of spontaneous pregnancy in 1 year after varicocele treatment was 32 to 41% of cases. Conclusion. Varicocelectomy significantly improved sperm motility, concentration, and testicular volume. There were 32 to 41% of infertile patients who achieved pregnancy spontaneously.

Free radicals in adolescent varicocele testis

We examine the relationship between the structure and function of the testis and the oxidative and nitrosative stress, determined by an excessive production of free radicals and/or decreased availability of antioxidant defenses, which occur in the testis of adolescents affected by varicocele. Moreover, the effects of surgical treatment on oxidative stress were provided. We conducted a PubMed and Medline search between 1980 and 2014 using “adolescent,” “varicocele,” “free radicals,” “oxidative and nitrosative stress,” “testis,” and “seminiferous tubules” as keywords. Cross-references were checked in each of the studies, and relevant articles were retrieved. We conclude that increased concentration of free radicals, generated by conditions of hypoxia, hyperthermia, and hormonal dysfunction observed in adolescent affected by varicocele, can harm germ cells directly or indirectly by influencing nonspermatogenic cells and basal lamina. With regard to few available data in current literature, further clinical trials on the pre- and postoperative ROS and RNS levels together with morphological studies of the cellular component of the testis are fundamental for complete comprehension of the role played by free radicals in the pathogenesis of adolescent varicocele and could justify its pharmacological treatment with antioxidants.

Characterisation of a subpopulation of sperm with massive nuclear damage, as recognised with the sperm chromatin dispersion test

Assessment of human sperm DNA fragmentation by the sperm chromatin dispersion (SCD) test is based on the detection of haloes of spreading DNA loops after sequential DNA denaturing and protamine removal. After the SCD test, sperm without DNA fragmentation show chromatin haloes emerging from the central nuclear core, while sperm containing fragmented DNA present small or no haloes. The nuclear degraded sperm are recognised as a differentiated category within the sperm with fragmented DNA, whose cores appear irregularly and/or faintly stained. This subpopulation is more prevalent in patients with varicocele. Protein staining with 2.7-dibrom-4-hydroxy-mercury-fluorescein demonstrated that degraded sperm intensely lose nuclear core proteins after the SCD processing. Moreover, degraded sperm are 65% more faintly labelled for DNA breaks after in situ nick translation (ISNT) on average, due to extensive DNA loss. A two-dimensional comet assay under sequential neutral and alkaline conditions demonstrated that degraded sperm contain both massive double- and single-strand DNA breaks. The degraded sperm appear as a subpopulation with stronger nuclear damage, affecting both DNA and protein fractions, possibly due to intense intratesticular oxidative stress, what could explain its higher proportion in patients with varicocele.

Evaluating a novel panel of sperm function tests for utility in predicting intracytoplasmic sperm injection (ICSI) outcome

PURPOSE

The objective of this study was to evaluate a panel of three sperm function tests; tests known to assess different aspects of sperm functionality and genomic integrity, the: 1) Sperm DNA Accelerated Decondensation (SDAD(TM)) Test, 2) Sperm DNA Decondensation (SDD(TM)) Test, and 3) Sperm Penetration Assay (SPA), determining if positive and negative test scores correlated with failed and successful ICSI outcomes, respectfully.

METHODS

A prospective, double blinded, cohort study was performed. One study sample (ejaculated semen) was collected by each of the 60 male partners of the 60 couples enrolled in the study; males whose female partners were found to have no major female factor issues. The sperm from each male was analyzed in the SPA, and SDAD and SDD Tests, and used for ICSI (1 ICSI cycle per couple).

RESULTS

The ICSI cycle pregnancy rate for this study was 50 %, with a delivery rate=40 % (n=60 ICSI cycles). The SPA and SDD Test scores did not significantly predict ICSI outcome when used as stand-alone tests (p>>0.05). However, when the SPA and SDD Test scores were used together, ICSI outcomes for a subgroup of 10 (16.7 %) males, were significantly predicted (p=0.03), with 1 live birth, and 9 negatives where the transferred embryos did not implant. In total, 38.4 % of the couples in this study were found to have a very poor chance for a successful ICSI cycle.

CONCLUSION

SDAD Test scores alone, and SPA and SDD Test scores used together, significantly predicted failed ICSI outcomes. This indicates that the scores obtained when analyzing patients' sperm using a panel of sperm function tests; specifically, the SPA, and SDAD and SDD Tests, can be used to identify infertile couples who should not be directed to ICSI.

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

Varicocele, the leading cause of male infertility, can impair spermatogenesis through several pathophysiological mechanisms. Of these, current evidence suggests that oxidative stress is the central element contributing to infertility in men with varicocele, to which the testis responds by way of heat stress, ischaemia or production of vasodilators, such as nitric oxide. Surgical varicocele repair (varicocelectomy) is beneficial not only for alleviating oxidative stress-associated infertility, but also for preventing and protecting against the progressive character of varicocele and its consequent upregulations of systemic oxidative stress. However, antioxidant therapy in infertile men with surgically treated and those with untreated varicocele is poorly studied, and well-designed trials are needed.

INHIBIN B LEVELS IN PERIPHERAL VEIN DO NOT CORRELATE WITH INHIBIN B LEVELS IN THE SPERMATIC VEIN IN ADOLESCENTS WITH VARICOCELE

This study was conducted to evaluate the inhibin B with FSH and LH levels on spermatogenesis in varicocele patients. The study group consisted of 10 adolescent with left idiopathic varicocele of grade II and III. Blood specimens were obtained from dilated spermatic vein and peripheral vein simultaneously. Peripheral samples were also collected from 7 healthy children as controls. Inhibin B was measured with ELISA inhibin B kits. FSH and LH were analyzed by radioimmunoassay techniques. The results were analyzed using Mann-Whitney U and Spearman's rank tests. A value of p < 0.05 was considered significant. Peripheral FSH, LH and inhibin B levels were the same in the study and control group (p > 0.05). Mean inbibin B levels of spermatic vein were significantly higher than the control and peripheral blood of the study groups (p < 0.05). FSH, LH, and inhibin B levels correlated poorly each other (p > 0.05). Preoperative serum inhibin B concentration could not reliably predict a response to varicocelectomy, but the increase in inhibin B levels after treatment might suggest an improvement in testicular function.

Role of oxidative stress in pathogenesis of varicocele and infertility

This review summarizes the published literature about the role of oxidative stress in the pathophysiology of varicocele and the beneficial effects of varicocele repair on oxidative stress. Literature survey was performed using the Medline, EMBASE, BIOSIS, and Cochrane databases between 1993 and 2008 that were relevant to oxidative stress and varicocele. Varicocele treatment can reduce reactive oxygen species levels and improve sperm parameters and pregnancy rates, although it is still controversial with Assisted Reproductive Techniques outcomes. We conclude that spermatozoal dysfunction in varicocele patients could be multifactorial, and oxidative stress-induced injury appears to be one of the main causes.

Sperm nuclear DNA fragmentation and mitochondrial activity in men with varicocele

OBJECTIVE

To verify the impact of varicocele on semen quality and sperm function (DNA integrity and mitochondrial activity).

DESIGN

Prospective study.

SETTING

Patients in an academic research environment.

PATIENT(S)

Seventeen patients with a clinical diagnosed varicocele of grade II or III and 20 men without a varicocele.

MAIN OUTCOME MEASURE(S)

Rate of sperm DNA fragmentation as assessed by the Comet assay and categorized as classes I (no DNA fragmentation), II (little DNA fragmentation), III (meaningful DNA fragmentation), and IV (high DNA fragmentation). Rate of mitochondrial activity as assessed by the diaminobenzidine (DAB) assay and categorized as grades I (all mitochondria active), II (most mitochondria active), III (most mitochondria inactive), and IV (all mitochondria inactive).

RESULT(S)

No statistically significant differences were found between the study and control groups with respect to age, ejaculatory abstinence, and round cell count. Men with varicocele had significantly higher ejaculate volume, concentration of immotile sperm, and neutrophil count and lower mean percentage of sperm concentration, progressive motility, and morphology than men in the control group. The study group presented a lower percentage of sperm with little DNA fragmentation (class II) and a higher percentage of sperm with DNA fragmentation (class IV). In addition, the study group presented a greater percentage of sperm with inactive mitochondria (class III).

CONCLUSION(S)

Compared with men without varicocele, men with varicocele had a higher percentage of cells with DNA fragmentation and sperm with inactive mitochondria. Indeed, varicocele causes a decrease in motility, concentration, and morphology and an increase in volume and concentration of immotile sperm and neutrophils. The sperm functional evaluation (DNA fragmentation and mitochondrial activity) could be important factors in deciding treatment options for men with varicocele.

Sperm nuclear DNA fragmentation in adolescents with varicocele

OBJECTIVE

To verify if sperm from adolescents with varicocele have an increased rate of DNA fragmentation when compared with adolescents without varicocele.

DESIGN

Controlled prospective study.

SETTING

Patients in an academic research environment.

PATIENT(S)

Adolescent patients with a clinical diagnosed bilateral varicocele, grades II and III, and adolescent patients without a varicocele.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Rate of sperm DNA fragmentation as assessed by the Comet assay, graded as class I (no DNA fragmentation), II (little DNA fragmentation), III (meaningful DNA fragmentation), or IV (high DNA fragmentation).

RESULT(S)

A higher percentage of cells with no DNA fragmentation (class I) was found in the nonvaricocele group (47.62 +/- 7.69) when compared with the varicocele group (27.52 +/- 10.73). A higher percentage of sperm with class III and class IV DNA fragmentation was found in the varicocele group (20.43 +/- 8.97, and 19.57 +/- 10.68) when compared with the nonvaricocele group (11.38 +/- 5.55, and 5.71 +/- 2.35).

CONCLUSION(S)

Although standard semen analysis showed no difference between the groups, adolescents with varicocele have an increase in sperm nuclear DNA fragmentation. Thus, DNA fragmentation evaluation could be important in deciding treatment options for adolescent patients.

Effect of varicocelectomy on the plasma oxidative stress parameters

AIM OF STUDY

This study evaluates the long-term effect of varicocelectomy as measured by plasma oxidative stress parameters.

METHODS

Eleven children aged 10 to 16 years presented with left-sided varicocele and ipsilateral testicular hypoplasia. Peripheral blood samples for C-reactive protein, basal thiobarbituric acid reactive substances (TBARS), and plasma peroxidation susceptibility (lag time and slope) were obtained preoperatively and at 1 year after the varicocelectomy. All patients underwent inguinal microvascular varicocelectomy with testicular-inferior epigastric (spermatic-epigastric) venous shunt, and a blood sample from the pampinous plexus was taken. Student's t test for unpaired and paired data was used with a level of significance set at P < .05.

RESULTS

When compared with controls, the cohort preoperative basal TBARS (mean, 2.07 nmol/mL; SD, 0.56 nmol/mL) were higher (P = .009), and plasma peroxidation susceptibility lag time (mean, 132.92 minutes; SD, 32.8 minutes) was lower (P = .0002). Blood samples from the pampiniform plexus showed similar results. Peroxidative plasma levels were significantly reduced on peripheral venous specimens taken 1 year after varicocelectomy with mean (SD) TBARS of 1.53 (0.41) nmol/mL (P = .0003) and mean (SD) lag time of 183.7 (17.46) minutes (P = .0025). The slope did not show significant changes compared with controls, or before and after surgery.

CONCLUSION

Peroxidative plasma levels were significantly reduced 1 year after surgery, indicating that surgical varicocelectomy with construction of venous shunt reduces oxidative stress.