Molecular mechanisms involved in varicocele-associated infertility

Effects of probiotic supplementation on semen parameters after varicocelectomy: A randomized controlled trial

Background

The use of probiotics in the treatment of infertility is a new area of research. In this study, our objective was to examine the efficacy of probiotic supplementation on semen parameters following varicocelectomy.

Materials and Methods

We included infertile men in our study who were the candidates for subinguinal microscopic varicocelectomy. After the surgical procedure, the patients were randomly assigned into two groups: 38 individuals received probiotic supplementation (FamiLact®), while 40 individuals received a placebo for 3 months. We compared the preoperative semen parameters with the postoperative parameters to evaluate the effects of probiotic supplementation.

Results

A total of 78 patients were included in the study. The two groups were similar in terms of age, body mass index, infertility period, and semen parameters at baseline (P > 0.05). A statistically significant difference was found in sperm concentration (33.7 ± 22.5 vs. 21.1 ± 16.1 × 106/mL, P = 0.046), and the percentage of sperms with normal morphology (15.0 ± 8.9 vs. 12.0 ± 11.5, P = 0.016) at 3 months favoring the probiotic group. Although the probiotic group exhibited higher values for semen volume and sperm motility at 3 months, the differences were not statistically significant (P = 0.897 and P = 0.177, respectively).

Conclusion

Our study demonstrates that the short-term use of probiotics after varicocelectomy can provide additional benefits in improving semen parameters. Probiotic supplements are cost-effective and well tolerated, making them a suitable option for enhancing the outcomes of varicocelectomy.

N6-methyladenosine modification of PLOD2 causes spermatocyte damage in rats with varicocele

BACKGROUND

In recent years, N6-methyladenosine (m6A) methylation modification of mRNA has been studied extensively. It has been reported that m6A determines mRNA fate and participates in many cellular functions and reactions, including oxidative stress. The PLOD2 gene encodes a protein that plays a key role in tissue remodeling and fibrotic processes.

METHODS

The m6A methylation and expression levels of PLOD2 were determined by m6A methylated RNA immunoprecipitation sequencing (MeRIP-seq) and MeRIP-quantitative polymerase chain reaction (qPCR) in the testes of varicocele rats compared with control. To determine whether IGF2BP2 had a targeted effect on the PLOD2 mRNA, RNA immunoprecipitation-qPCR (RIP-qPCR) and luciferase assays were performed. CRISPR/dCas13b-ALKBH5 could downregulate m6A methylation level of PLOD2, which plays an important role in PLOD2-mediated cell proliferation and apoptosis in GC-2 cells.

RESULTS

PLOD2 was frequently exhibited with high m6A methylation and expression level in the testes of varicocele rats compared with control. In addition, we found that IGF2BP2 binds to the m6A-modified 3' untranslated region (3'-UTR) of PLOD2 mRNA, thereby positively regulating its mRNA stability. Targeted specific demethylation of PLOD2 m6A by CRISPR/dCas13b-ALKBH5 system can significantly decrease the m6A and expression level of PLOD2. Furthermore, demethylation of PLOD2 mRNA dramatically promote GC-2 cell proliferation and inhibit cell apoptosis under oxidative stress.

CONCLUSION

As a result, we found that varicocele-induced oxidative stress promoted PLOD2 expression level via m6A methylation modification. In addition, targeting m6A demethylation of PLOD2 by CRISPR/dCas13b-ALKBH5 system can regulate GC-2 cell proliferation and apoptosis under oxidative stress. Taken together, our study has acquired a better understanding of the mechanisms underlying male infertility associated with oxidative stress, as well as a novel therapeutic target for male infertility.

Genetic variants in varicocele-related male infertility: a systematic review and future directions

Genetic association studies (GAS) may have the capability to probe the genetic susceptibility alleles in many disorders. This systemic review aimed to assess whether an association exists between gene(s)/allelic variant(s), and varicocele-related male infertility (VRMI). This review included 19 GAS that investigated 26 genes in 1,826 men with varicocele compared to 2,070 healthy men, and 263 infertile men without varicocele. These studies focussed on candidate genes and relevant variants, with glutathione S-transferase gene being the most frequently studied (n = 5) followed by the nitric oxide synthase 3 (NOS3) gene (n = 3) and the phosphoprotein tyrosine phosphatase 1 gene (n = 2). In one study the genes for NAD(P)H quinone oxidoreductase 1, sperm protamine, human 8-oxoguanine DNA glycosylase 1, methylenetetrahydrofolate reductase, polymerase gamma, heat shock protein 90, mitochondrial DNA, superoxide dismutase 2, transition nuclear protein 1, and transition nuclear protein 2, were assessed. There is no clear indication that any of these polymorphisms are sturdily associated with VRMI. However, three studies established that the polymorphic genotype (GT + TT) for rs1799983 polymorphism of the NOS3 gene is more frequent in varicocele patients. Further endeavours such as standardising reporting, exploring complementary designs, and the use of GWAS technology are justified to help replicate these early findings.

Elastography and contrast-enhanced ultrasound to assess the effect of varicocelectomy: A case-controlled study

To evaluate the changes in testicular stiffness and microcirculation caused by spermatic vein ligation in patients with varicocele, we conducted a case-controlled study. A total of 27 grade III left varicocele cases were enrolled. Testicular stiffness and perfusion were evaluated by shear wave elastography and contrast-enhanced ultrasound during subinguinal microscopic varicocelectomy. The external and the internal parenchyma of bilateral testes were selected to compare the shear wave velocity of bilateral testes during the spermatic vein ligation. We mapped and compared the intensity-time curves following bolus contrast injection three times in the same region of interest. Initially, the shear wave velocity of the left internal parenchyma was higher than the right side (1.10 ± 0.06 m/s vs. 1.00 ± 0.03 m/s). It decreased (1.09 ± 0.06 m/s) (p < 0.05) after ligation. Meanwhile, the left epididymis had the higher agent peak intensity (0.90 × 10E-5 AU), the largest area under the curve (80.20 × 10E-5 AU s), and the longest washout area (54.35 × 10E-5 AU s). In addition, the left internal parenchyma presented a sharper slope (0.18 × 10E-5 AU/s) (p < 0.05). In conclusion, the spermatic vein ligation improved the perfusion of the internal testicular parenchyma, but it could temporally deteriorate the stasis of the epididymis. These changes caused softer testicular parenchyma.

Impacts of cadmium on male fertility: Lessons learnt so far

Cadmium (Cd) is one of the most dangerous heavy metals in the world. Globally, toxicities associated with cadmium and its attendant negative impact on humans and animals cannot be under-estimated. Cd is a heavy metal, and people are exposed to it through contaminated foods and smoking. Cd exerts its deleterious impacts on the testes (male reproductive system) by inducing oxidative stress, spermatogenic cells apoptosis, testicular inflammation, decreasing androgenic and sperm cell functions, disrupting ionic homeostasis, pathways and epigenetic gene regulation, damaging vascular endothelium and blood testes barrier. In association with other industrial by-products, Cd has been incriminated for the recent decline of male fertility rate seen in both man and animals. Understanding the processes involved in Cd-induced testicular toxicity is vital for the innovation of techniques that will help ameliorate infertility in males. In this review, we summed up recent studies on the processes of testicular toxicity and male infertility due to Cd exposure. Also, the usage of different compounds including phytochemicals, and plant extracts to manage Cd reprotoxicity will be reviewed.

Influence of Risk Factors for Male Infertility on Sperm Protein Composition

Male infertility is a common health problem that can be influenced by a host of lifestyle risk factors such as environment, nutrition, smoking, stress, and endocrine disruptors. These effects have been largely demonstrated on sperm parameters (e.g., motility, numeration, vitality, DNA integrity). In addition, several studies showed the deregulation of sperm proteins in relation to some of these factors. This review inventories the literature related to the identification of sperm proteins showing abundance variations in response to the four risk factors for male infertility that are the most investigated in this context: obesity, diabetes, tobacco smoking, and exposure to bisphenol-A (BPA). First, we provide an overview of the techniques used to identify deregulated proteins. Then, we summarise the main results obtained in the different studies and provide a compiled list of deregulated proteins in relation to each risk factor. Gene ontology analysis of these deregulated proteins shows that oxidative stress and immune and inflammatory responses are common mechanisms involved in sperm alterations encountered in relation to the risk factors.

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

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

Evaluation of testicular spermatogenic function by ultrasound elastography in patients with varicocele-associated infertility

OBJECTIVE

To investigate the application of ultrasound elastography and color Doppler ultrasound in the evaluation of testicular spermatogenic function in patients with varicocele (VC) associated infertility.

METHODS

A total of 196 patients with VC-associated infertility treated in our hospital from January 2018 to January 2020 were included as the research subjects (VC group), and were classified into VC I group (66 cases), VC II group (60 cases), and VC III group (70 cases) according to the diameter of spermatic vein and the degree of reflux under ultrasound. 50 age-matched healthy subjects were included as the control group. Color ultrasound, ultrasound elastography and semen examination were performed on all patients.

RESULTS

Compared with control group, a lower left testicular volume in VC group and a lower right testicular volume in VC III group were observed, and the left testicular volume was inversely proportional to VC grade (all P<0.05). Statistically significant differences in sperm viability, sperm density, peak systolic velocity (PSV), and MEAN values were determined among the 4 groups by one-way ANOVA, and between two groups by the independent-samples t test (all P<0.05). Pearson correlation analysis revealed that sperm viability and sperm density had no correlation with PSV, resistive index (RI) and pulsatility index (PI) of the left testicular artery in VC group, but were negatively correlated with the MEAN values of the testis.

CONCLUSION

Ultrasound elastography can predict the semen quality in patients with VC-associated infertility.

CLINICAL TRIAL REGISTRATION

This study was registered with the registration No. ChiCTR2010189 (URL: http://www.chictr.org.cn/showproj.aspx?proj=2018XE057-3).

Seminal plasma miR-210-3p induces spermatogenic cell apoptosis by activating caspase-3 in patients with varicocele

The aim of this study was to investigate the role of seminal plasma miR-210-3p in the impairment of semen quality caused by varicocele. This study included 102 patients whose semen quality was normal when they were diagnosed with varicocele. A 2-year follow-up for included patients was performed, and they were divided into Group A (semen quality became abnormal) and Group B (semen quality remained normal) according to the results of semen analysis during the follow-up. Semen parameters and seminal plasma miR-210-3p expression were investigated by semen analysis and quantitative real-time polymerase chain reaction, respectively. In vitro experiments with GC-2 cells were performed to explore the role of miR-210-3p in spermatogenic cells. The results of quantitative real-time polymerase chain reaction showed that the level of seminal plasma miR-210-3p in Group A was higher than that in Group B both after 2-year follow-up and when they were diagnosed with varicocele (both P < 0.01). Apoptosis and proliferation assays showed that miR-210-3p induces apoptosis of spermatogenic cells by promoting caspase-3 activation. In conclusion, our study indicated that seminal plasma miR-210-3p induces spermatogenic cell apoptosis by activating caspase-3 in patients with varicocele. Seminal plasma miR-210-3p may be a potential biomarker for predicting impaired semen quality caused by varicocele.

Assessment of seminal calcium and magnesium levels in infertile men with varicocele before and after varicocelectomy

BACKGROUND

Trace elements perform a vital role in all stages of human physiology, as well as reproduction.

OBJECTIVE

This study aimed to assess seminal calcium (Ca) and magnesium (Mg) in infertile men associated with varicocele (Vx).

MATERIALS AND METHODS

Overall, 50 men were divided into two groups: fertile men (n = 20) and infertile men who were scheduled for Vx surgical repair (n = 30). Exclusion criteria were as follows: azoospermia, smoking, leukocytospermia, and consumption of Ca and/or Mg supplements. All cases were subjected to history taking and clinical examination. Semen analysis and assessment of seminal Ca and Mg by the colorimetric method were carried out for all cases at the base point and 3 months postvaricocelectomy.

RESULTS

Generally, the mean seminal Ca and Mg levels demonstrated significant decreases in infertile men with Vx compared with the healthy fertile men linked to higher Vx grade as well as Vx bilaterality. These seminal decreases demonstrated significant increases after Vx surgical repair. Collectively, seminal Ca and Mg levels showed a significant positive correlation (r = 0.665, p= 0.001). Besides, seminal Ca, Mg levels, and Ca/Mg ratio showed significant positive correlation with sperm concentration (r = 0.479, p = 0.001; r = 0.541, p = 0.001; r = 0.282, p = 0.001, respectively), sperm motility percentage (r = 0.493, p = 0.001; r = 0.477, p = 0.001; r = 0.353, P = 0.001, respectively), and sperm normal forms percentage (r = 0.578, p = 0.001; r = 0.520, p = 0.001; r = 0.430, p = 0.001, respectively).

DISCUSSION AND CONCLUSION

Seminal Ca and Mg levels and Ca/Mg ratio are significantly decreased in infertile men associated with Vx compared with fertile men with significant increases after varicocelectomy.

Improvement of sperm morphology after surgical varicocele repair

Background

A causative relationship between varicocele and impairment of semen quality has been largely investigated in the context of male infertility, although its clinical benefit remains controversial.

Objective

To investigate the effect of varicocele correction on detailed morphologic microscopic semen parameters in a large homogeneous cohort of patients and to evaluate which factors could predict semen improvement after the surgical treatment.

Materials and methods

An observational, retrospective cohort study was carried out including all patients undergoing surgical treatment for varicocele from September 2011 to March 2020 in the same clinical centre. Enrolled males performed at least one semen analysis before and one after surgical varicocele correction. Primary outcome was the detailed morphologic microscopic sperm evaluation. Secondary outcomes were conventional semen analyses.

Results

A total of 121 males (mean age 24.6 ± 6.1 years) were enrolled. Using detailed morphologic microscopic sperm evaluation, a significant morphological improvement was recorded, with a reduction in head and tail abnormalities. Moreover, a significant increase in sperm concentration (p = 0.015) and percentage of progressive and total motility (p = 0.022 and p = 0.039) were observed after surgery. The multivariate logistic analysis identified the ultrasonography varicocele degree before surgery as a main predictor of the sperm concentration improvement (p = 0.016), with the highest improvement for varicocele of I and II degree.

Discussion

For the first time, the detailed morphologic microscopic sperm evaluation highlights a relevant reduction in sperm abnormalities after varicocele surgery, showing its potential application in clinical practice.

Sperm DNA damage and cytokines in varicocele: A case-control study

Varicocele is a vascular disease characterised by the abnormal enlargement of the pampiniform plexus veins and a well-known cause of male infertility. The aim of this study was to investigate the relationship between sperm DNA fragmentation (SDF) and inflammation in the pathogenesis of varicocele. We included 84 varicocele patients and 85 normozoospermic healthy controls, further analysed according to the body mass index, the smoking habit (smokers/non-smokers) and the varicocele severity (low/high grade). Semen parameters, SDF (by TUNEL) and inflammatory cytokines (by Luminex xMAP analysis) were evaluated. Varicocele patients showed significantly reduced semen parameters (volume, total sperm number, progressive motility, normal morphology) and increased SDF. Moreover, we observed a significant reduction of IFN-γ, IL-6, TNF-α and an increase of IL-10. No difference was reported according to the smoking habit, body mass index and varicocele severity. The observed cytokines pathway suggests the establishment of a chronic inflammatory condition, which may contribute to the alteration of semen quality. A thorough knowledge of the cytokine network might contribute to better understanding the link between inflammation and semen quality in varicocele and its impact on reproductive health.

Effects of HIF-1α on Spermatogenesis of Varicocele Rats by Regulating VEGF/PI3K/Akt Signaling Pathway

Hypoxia-inducible factor-1α (HIF-1α) participates in the regulation of spermatogenic function in rats with varicocele (VC), and the PI3K/Akt pathway plays an important role in it. In the present research, we applied the CRISPR/Cas9 gene editing technique to silence the HIF-1α gene of VC rat testis, to explore the effect of HIF-1α on apoptosis of spermatogenic cells in VC rats through the PI3K/Akt pathway. Sprague Dawley rats were randomly assigned to four groups, including the normal rat group (group N), VC model group (group V), VC + HIF-1α-lentivirus group (group H), and VC + luciferase-lentivirus group (group L). Apoptosis of spermatogenic cells in rat testis was tested by TUNEL Kit. The morphologic changes of seminiferous tubules were viewed by a light microscope. Expressions of VEGF, Akt, p-Akt, p70S6K, and p-p70S6K were detected by means of Western blot, immunofluorescence, or immunohistochemistry methods. One-way ANOVA was applied to analyze the diverseness between groups. Compared with group N, the distribution of germ cells was disordered, apoptosis of spermatogenic cells increased significantly, and the expression of VEGF, p-Akt, and p-p70S6K was also increased in group V. Compared with group V, the damage of seminiferous epithelium in group H was improved, and the arrangement of the seminiferous epithelium was almost orderly. Apoptosis of spermatogenic cells decreased significantly, and the expression of VEGF, p-Akt, and p-p70S6K protein was decreased (P < 0.05). There was no significant difference between group N and group H (P > 0.05).In conclusion, HIF-1α is regulated by hypoxia in rats with varicocele to regulate its downstream gene VEGF which regulates spermatogenesis, and the PI3K/Akt signaling pathway plays a regulatory role in this process.

Fumaria parviflora regulates oxidative stress and apoptosis gene expression in the rat model of varicocele induction

Varicocele is one of the leading causes of male infertility in which oxidative stress induces DNA damages in spermatozoa of patients with varicocele. Recent studies indicated that the treatment with antioxidant agents has protective effects against the formation of reactive oxygen species (ROS). Our research aimed to evaluate the impact of Fumaria Parviflora (FP) on the varicocele-induced testicular injury. For this purpose, 32 adult male Wistar rats (n = 8 per group) were randomly assigned to four groups as follows: sham group, varicocele group, varicocele treatment group and the control treatment group. The experimental groups daily received FP (250 mg/kg) for 8 weeks. The induction of varicocele was conducted by partial occlusion on the left renal vein. The diameter of seminiferous tubules, Johnsen's score and the epithelium thickness improved in the treated-varicocele group as compared to the varicocele group. FP extract could increase the biochemical parameters including superoxide dismutase and glutathione peroxidase, and also decrease malondialdehyde level in the varicocele group. Furthermore, varicocele markedly increased both mRNA and intensity of Bax, while treatment with FP could alleviate them. We concluded that FP could alleviate varicocele, possibly by lowering oxidative stress and testicular damage.

Seminal Plasma Analysis of Oxidative Stress in Different Genitourinary Topographical Regions Involved in Reproductive Tract Disorders Associated with Genital Heat Stress

The pathophysiological mechanisms responsible for male subfertility/infertility caused by or complicated by genital heat stress remains unclear in many respects. Because seminal plasma creates the environment for the proper functioning of spermatozoa, in this study, we verified the associations among standard spermiograms, seminal biochemical parameters (neutral alpha-glucosidase, fructose, and citric acid) and oxidative stress markers (total antioxidant capacity, catalase activity, superoxide dismutase activity, and malondialdehyde concentration) in distinct entities associated with male infertility with and without long-time exposure to local hyperthermia. We demonstrated that men exposed to prolonged environmental or clinically recognized local heat stress in adulthood may suffer from dysregulation of seminal antioxidant components, which can be directly associated with epididymal and prostate function. The comparative analysis of the studied parameters showed numerous correlations among all biochemical parameters (particularly neutral alpha-glucosidase) with low standard semen quality in almost all the investigated infertile groups. In light of the data obtained in this originally designed study, we conclude that more attention should be paid to the epididymis and accessory gland function in subfertile and infertile men exposed to genital heat stress, especially in the context of novel treatment algorithms (targeted therapies).

Infertility duration and pre-operative sperm progressive motility are significant factors of spontaneous pregnancy after varicocele repair

PROBLEM

Varicocele may lead to testicular dysfunction and male infertility. Varicocelectomy can improve both semen quality and post-operative spontaneous pregnancy. However, different patients benefit distinctly from the surgery. Therefore, the study aims at examining the possible factors of spontaneous pregnancy after laparoscopic varicocelectomy in infertile men.

METHOD OF STUDY

Clinical data of 196 infertile men who underwent laparoscopic varicocelectomy at our institute were collected from December 2013 to February 2019. Follow-up data were available for 148 patients. All the patients were treated with laparoscopic varicocelectomy performed by experienced urological doctors. Possible pre-operative factors of spontaneous pregnancy after laparoscopic varicocelectomy were retrospectively analyzed.

RESULTS

After a mean follow-up of 29.1 ± 12.6 months (range 12-74 months), 74 (50%) of couples achieved spontaneous pregnancy. Univariate analysis revealed that short infertility duration, secondary infertility, and high sperm progressive motility were significant predictors of spontaneous pregnancy after laparoscopic varicocelectomy. Multivariate analysis revealed that short infertility duration (≤2 years) and high sperm progressive motility (>30%) were independent predictors.

CONCLUSION

Both infertility duration and pre-operative sperm progressive motility could serve as independent factors of spontaneous pregnancy after laparoscopic varicocelectomy.

Sperm DNA status in infertile patients with clinical varicocele

OBJECTIVE

To evaluate if a potential relationship exists between sperm nuclear DNA damage and clinical varicocele and to determine the impact of clinical varicocele on standard semen parameters.

MATERIALS AND METHODS

A prospective study involving 30 infertile patients with clinical varicocele and 15 controls patients referred to our laboratory for routine spermiological exploration. Spermograms were performed and analyzed according to World Health Organisation (WHO) guidelines 2010. The DNA fragmentation was detected by the terminal desoxynucleotidyl transferase-mediated deoxyuridine triphosphate biotin nick-end labeling (TUNEL) assay.

RESULTS

The DNA fragmentation index (DFI) was significantly higher in patients with clinical varicocele compared to controls (13.3±3.4% versus 6.1±2.5%, P=0.0001). In addition, the DFI was positively and significantly correlated with the degree of severity of varicocele thus the DFI was 15.24±1.9% in patients with grade 3 versus 12.92±3.5% in those with grade 2(P<0.0001). However, an abnormality of at least one of the spermatic parameters was found in 90% of varicocele patients, and all semen characteristics such as sperm count, vitality, mobility and typical forms were decreased compared to the controls. Furthermore, statistically significant negative correlations were noted between sperm DNA fragmentation index and sperm concentration (P=0.0001), motility (P=0.03), and normal sperm morphology (P=0.03).

CONCLUSION

Clinical varicocele generates a significant increase of sperm abnormalities and DNA damage, and these changes are positively correlated with varicocele grade. Sperm DNA damage independent of its cause, may affect the quality of the ejaculated sperm and may have implications on patient's fertility potential.

LEVEL OF EVIDENCE

3.

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.

Down regulating PHGDH affects the lactate production of sertoli cells in varicocele

BACKGROUND

Although varicocele is considered to be one of the leading causes of male infertility, the precise mechanism underlying how varicocele leads to male infertility is not completely understood. We found the lactate concentration on the varicocele side of the patients was decreased compare with peripheral venous blood. In the testicles, the lactate produced by the sertoli cells through the glycolysis pathway provides most of the energy needed for spermatogenesis, the reduction of lactate will affect spermatogenesis. The objective of this study was to investigate the mechanism of this abnormal energy metabolism phenomenon in varicocele.

METHODS

In this study, we collected the testicular tissue from patients with varicocele, the glycolysis related proteins PHGDH was identified by iTRAQ proteomics technology. Experimental rat varicocele model was constructed according to our new clip technique, the mRNA and protein expression levels of PHGDH were examined with qRT-PCR and Western blotting. We constructed a sertoli cell of PHGDH down-regulation model, and then detected the glucose consumption, LDH activities and lactate production in the sertoli cells. Western blot was conducted to investigate the effects of PHGDH on the expression of phosphoserine phosphatase (PSPH) and Pyruvate kinase M2 (PKM2). Flow cytometry was used to detect the cell apoptosis and cell cycle in sertoli cells.

RESULTS

The results showed that testicular protein PHGDH was down-regulated in patients with varicocele and in experimental rat varicocele model. Down-regulation of PHGDH in sertoli cells significantly decreased the glucose consumption, LDH activities and lactate production in the sertoli cells, indicating that the low expression of PHGDH ultimately led to a decrease in lactate production by affecting the glycolysis. The Western blot results showed that the down-regulation of PHGDH significantly reduced the expression of pathway protein PSPH and PKM2, leading to the reduction of lactate production. Moreover, PHGDH knockdown can promote apoptosis and inhibit cell cycle to affect cell growth.

CONCLUSIONS

Overall, we conformed that varicocele lead to the decreasing of testis lactate production. Down-regulation of PHGDH in sertoli cells may mediate the process of abnormal glucose metabolism. Our study provide new insight into the mechanisms underlying metabolism-associated male infertility and suggests a novel therapeutic target for male infertility.

Varicocele Repair Prior to Assisted Reproductive Technology: Patient Selection and Special Considerations

Clinical varicoceles are one of the most commonly identified physical exam abnormalities in men presenting with infertility. Clinical varicoceles can cause impaired spermatogenesis and surgical correction can improve semen parameters in select men. Increasingly, andrologists are performing varicocele repairs prior to intrauterine insemination (IUI), in vitro fertilization (IVF), and intracytoplasmic sperm injection (ICSI) to boost male fertility potential. In this review, we evaluated the available literature 1) to determine if varicocelectomy prior to IUI or assisted reproductive technologies proved to improve sperm production or pregnancy outcomes; and 2) to identify who may be the ideal candidate for pre-IUI/ART varicocelectomy. Overall, few studies have explored this topic and little can be concluded about the impact of varicocelectomy prior to IUI. The evidence, however, does support that correcting a clinical varicocele can increase pregnancy outcomes in couples who plan to pursue IVF or ICSI. When selecting patients for varicocelectomy prior to IUI or ART, clinicians should evaluate female age as improvement in semen parameters can take 6 months after varicocelectomy and this duration of time may be deleterious in cases of advanced maternal age when each cycle becomes increasingly important. Overall, the currently limited literature regarding clinical varicoceles correction demonstrates that pregnancy rates can be increased when comparing patients who have undergone varicocelectomy prior to ART with those who had clinical varicocele but did not undergo surgery.

Effects of percutaneous varicocele repair on testicular volume: results from a 12-month follow-up

Varicocele is a common finding in men. Varicocele correction has been advocated for young patients with testicular hypotrophy, but there is a lack of morphofunctional follow-up data. We assessed whether percutaneous treatment of left varicocele is associated with testicular "catch-up growth" in the following 12 months by retrospectively reviewing data from an electronic database of 10 656 patients followed up in our clinic between 2006 and 2016. We selected all young adults (<35 years) with left varicocele who underwent percutaneous treatment, had a minimum of 12 months' ultrasound imaging follow-up, and had no other conditions affecting testicular volume. One hundred and fourteen men (mean±standard deviation [s.d.] of age: 22.8 ± 5.4 years) met the inclusion and exclusion criteria. Left testicular hypotrophy (LTH), defined as a ≥20% difference between left and right testicular volume at baseline, was observed in 26 (22.8%) men. Participants with LTH (mean±s.d.: 14.5 ± 2.7 ml) had lower baseline testicular volume compared to those without LTH (mean±s.d.: 15.7 ± 3.8 ml; P = 0.032). Repeated measures mixed models showed a significant interaction between LTH and time posttreatment when correcting for baseline left testicular volume (β = 0.114, 95% confidence interval [CI]: 0.018-0.210, P = 0.020), resulting in a catch-up growth of up to 1.37 ml per year (95% CI: 0.221-2.516). Age at intervention was also associated with reduced testicular volume (-0.072 ml per year, 95% CI: -0.135--0.009; P = 0.024). Percutaneous treatment of left varicocele in young adults with LTH can result in catch-up growth over 1 year of follow-up. The reproductive and psychological implications of these findings need to be confirmed in longer and larger prospective studies.

Aberrant Upregulation of Compensatory Redox Molecular Machines May Contribute to Sperm Dysfunction in Infertile Men with Unilateral Varicocele: A Proteomic Insight

Aims: To understand the molecular pathways involved in oxidative stress (OS)-mediated sperm dysfunction against a hypoxic and hyperthermic microenvironment backdrop of varicocele through a proteomic approach. Results: Protein selection (261) based on their role in redox homeostasis and/or oxidative/hyperthermic/hypoxic stress response from the sperm proteome data set of unilateral varicocele (UV) in comparison with fertile control displayed 85 to be differentially expressed. Upregulation of cellular oxidant detoxification and glutathione and reduced nicotinamide adenine dinucleotide (NADH) metabolism accompanied with downregulation of protein folding, energy metabolism, and heat stress responses were observed in the UV group. Ingenuity pathway analysis (IPA) predicted suppression of oxidative phosphorylation (OXPHOS) (validated by Western blotting [WB]) along with augmentation in OS and mitochondrial dysfunction in UV. The top affected networks indicated by IPA involved heat shock proteins (HSPs: HSPA2 and HSP90B1). Their expression profile was corroborated by immunocytochemistry and WB. Hypoxia-inducible factor 1A as an upstream regulator of HSPs was predicted by MetaCore. Occurrence of reductive stress in UV spermatozoa was corroborated by thiol redox status. Innovation: This is the first evidence of a novel pathway showing aberrant redox homeostasis against chronic hypoxic insult in varicocele leading to sperm dysfunction. Conclusions: Upregulation of antioxidant system and dysfunctional OXPHOS would have shifted the redox balance of biological redox couples (GSH/GSSG, NAD⁺/NADH, and NADP⁺/NADPH) to a more reducing state leading to reductive stress. Chronic reductive stress-induced OS may be involved in sperm dysfunction in infertile men with UV, where the role of HSPs cannot be ignored. Intervention with antioxidant therapy warrants proper prior investigation.

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

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

Efficacy of antioxidant therapy on sperm quality measurements after varicocelectomy: A systematic review and meta-analysis

Antioxidants were proved to be efficient to improve the quality of spermatozoa after varicocelectomy. We carried out a systematic review and performed a meta-analysis to evaluate the efficacy of antioxidant therapy in sperm parameters' quality after varicocelectomy during 3 or 6 months' treatment cycle. During research, randomised controlled trials were searched by MEDLINE, EMBASE and the Cochrane Controlled Trials Register, and necessary parameters were compared between two groups after varicocelectomy. Finally, six studies including 576 patients were included in our meta-analysis. As for sperm parameters, significant improvements of sperm concentration (p < .0001), sperm motility (p = .03), progressive sperm motility (p < .00001) and sperm morphology (p < .00001) were existed in antioxidant group 3 months after varicocelectomy. With regard to the 6 months' outcomes, sperm parameters were improved as well except sperm motility (p = .72) and progressive sperm motility (p = .57). Referring to pregnancy rate, no significant difference was existed between two groups (p = .36), and the FSH level of antioxidant group was lower than placebo group 3 or 6 months after varicocelectomy (3 months, p = .02; 6 months, p = .03). In conclusion, compared with the placebo, the antioxidant therapy after varicocelectomy can improve the quality of sperm parameters and construct a favourable living condition for spermatozoa by reducing FSH level.

GYY4137 a H2S donor, attenuates ipsilateral epididymis injury in experimentally varicocele-induced rats via activation of the PI3K/Akt pathway

OBJECTIVES

The current study was aimed to investigate the effect of morpholin-4-ium 4 methoxyphenyl (morpholino) phosphinodithioate (GYY4137) on ipsilateral epididymis injury in a rat model of experimental varicocele (VC).

MATERIALS AND METHODS

Sixty Wistar rats were randomly assigned to sham, sham plus GYY4137, VC and VC plus GYY4137 groups. Sperm quality parameters, including sperm count, motility and viability were evaluated after 4 weeks. Histological changes were measured by hematoxylin and eosin staining between the groups. The oxidative stress levels were estimated by determining epididymal superoxide dismutase (SOD) and malondialdehyde (MDA). The apoptosis status and the expression of phosphatidylinositol 3'-OH kinase (PI3K)/Akt were analyzed by immunohistochemical analysis, western blot and RT-qPCR.

RESULTS

VC resulted in the decrease of sperm parameters, significant histological damage and higher levels of oxidative stress and apoptosis. Compared to the VC group, GYY4137 markedly ameliorated these observed changes. In addition, treatment with GYY4137 obviously reduced the levels of caspase-3 and Bax and increased the levels of the phosphorylation of PI3K p85 and Akt.

CONCLUSION

Our data demonstrated that GYY4137 may alleviate the sperm damage and epididymis injury in experimentally VC-induced rats by activation of the PI3K/Akt pathway.

Protein Fingerprinting of Seminal Plasma Reveals Dysregulation of Exosome-Associated Proteins in Infertile Men with Unilateral Varicocele

Purpose

Aberrant expression of seminal plasma proteins are associated with altered homeostasis that may affect the fertilizing ability of spermatozoa. However, the precise roles of seminal exosomes on sperm function remain unclear. The objective of this study was to identify the differentially expressed proteins (DEPs) associated with varicocele-mediated infertility by comparing seminal plasma protein profile of unilateral varicocele patients with proven fertile donors.

Materials and Methods

Semen samples were obtained from 10 proven fertile donors with normal semen parameters and 33 infertile patients with unilateral varicocele. For proteomic analysis, 5 samples from each group were pooled and run in triplicate. Key DEPs (ANXA2, TF, CD63, KIF5B, SEMG1) associated with the exosome function were selected by bioinformatic tools and validated using Western blotting.

Results

A total of 47 seminal plasma proteins were differentially expressed in unilateral varicocele patients compared to fertile donors. Validation of exosome-associated DEPs in unilateral varicocele patients (n=7) and fertile donors (n=7) revealed significant upregulation of ANXA2 (p=0.0016) and downregulation of KIF5B (p=0.009). The main upstream regulators of the DEPs in seminal plasma of unilateral varicocele group were androgen receptor, YB1 and NRF2.

Conclusions

This is the first report to identify DEPs in seminal plasma of unilateral varicocele patients compared to fertile donors. Based on the detection of DEPs associated with exosomal function, Western blotting was used to validate the presence of defective exosome machinery in seminal plasma of unilateral varicocele patients. KIF5B and ANXA2 can be utilized as potential biomarkers of infertility in unilateral varicocele patients.

The clinical usefulness of a novel grading system for varicocoeles using duplex Doppler ultrasound examination based on postsurgical modifications of seminal parameters

BACKGROUND

The existing classifications of varicocoeles have poor predictive value regarding the effects of surgery on sperm count.

OBJECTIVE

To develop a new grading system for varicocoeles, useful as an indication for surgery.

MATERIALS AND METHODS

This is a three-center prospective study which examined 173 men having clinically detectable left varicocoeles and oligo ± astheno ± terato-spermia. The patients underwent medical history collection, objective examination, duplex Doppler ultrasound scrotal examination, hormonal profiles, two semen analyses before surgery, and two semen analyses after surgery. Sperm concentration, motility, and morphology (standard semen parameters) were evaluated 6 months after surgery in function of the following preoperative variables: patient age, follicle-stimulating hormone, clinical grade of varicocoele, right and left testicular volume, extension of venous reflux, and semen parameters. The venous reflux was graded in two centers using duplex Doppler ultrasound: reflux visible only with Valsalva and continuous reflux. Spearman's rank semiquantitative analysis was used. All patients had their varicocoeles corrected according to the Colpi technique.

RESULTS

The variables capable of determining an improvement in semen parameters after varicocoele correction were in order of decreasing importance: venous reflux extent assessed by scrotal duplex Doppler ultrasound examination, varicocoele clinical grade, basal semen parameters, and follicle-stimulating hormone. Male age did not influence postoperative semen quality. Only patients with continuous reflux had their standard semen parameters improved after surgery.

DISCUSSION

Venous reflux extent is the most critical variable capable of predicting semen improvement after varicocoelectomy.

CONCLUSIONS

A correct duplex Doppler assessment of venous reflux is mandatory for predicting postoperative improvement of the sperm count.

The Role of Varicocele in Male Factor Subfertility

PURPOSE OF REVIEW

Varicocele may play a significant role in a subset of patients presenting with male factor infertility. Despite its relatively high prevalence amongst subfertile men, there has been controversy over the effectiveness of surgical treatments, patient selection, and when to administer treatment, particularly in the era of assisted reproductive technology.

RECENT FINDINGS

In line with earlier finding, recent evidence strongly suggests that varicocelectomy improves pregnancy rates and semen parameters. The currently available literature still does not clearly elucidate the answer to this question, due to flaws in retrospective study design. Patients undergoing subinguinal microsurgical varicocelectomy appear to have the highest pregnancy rates, and lowest complication rates, compared to other surgical approaches. Current research has given us a better understanding of the relationship between varicocele and infertility. Amongst men presenting with semen analysis abnormalities and varicoceles, including those patients presenting with non-obstructive azoospermia or couples with a significant male factor component failing previous attempts at in vitro fertilization, varicocelectomy may improve take home baby rates. More robust, prospective, controlled studies are needed to further clarify the population of subfertile men with varicocele most likely to benefit from varicocelectomy.

Role of varicocele treatment in assisted reproductive technologies

Objective

In this review, we investigate the advantage of varicocele repair prior to assisted reproductive technologies (ART) for infertile couples and provide cost analysis information.

Materials and methods

We searched the following electronic databases: PubMed, Medline, Excerpta Medica Database (Embase), Cumulative Index to Nursing and Allied Health Literature (CINAHL). The following search strategy was modified for the various databases and search engines: 'varicocele', 'varicocelectomy', 'varicocele repair', 'ART', 'in vitro fertilisation (IVF)', 'intracytoplasmic sperm injection (ICSI)'.

Results

A total of 49 articles, including six meta-analyses, 32 systematic reviews, and 11 original articles, were included in the analysis. Bypassing potentially reversible male subfertility factors using ART is currently common practice. However, varicocele may be present in 35% of men with primary infertility and 80% of men with secondary infertility. Varicocele repair has been shown to be an effective treatment for infertile men with clinical varicocele, thus should play an important role in the treatment of such patients due to the foetal/genetic risks and high costs that are associated with increased ART use.

Conclusion

Varicocele repair is a cost-effective treatment method that can improve semen parameters, pregnancy rates, and live-birth rates in most infertile men with clinical varicocele. By improving semen parameters and sperm structure, varicocele repair can decrease or even eliminate ART requirement.

Spermatozoal Fractalkine Signaling Pathway Is Upregulated in Subclinical Varicocele Patients with Normal Seminogram and Low-Level Leucospermia

Background

Fractalkine is produced in seminal plasma in small amounts and correlates with sperm motility.

Purpose

To investigate the possible effect of low-level leucospermia on spermatozoa oxidative stress and sDNA fragmentation in patients with subclinical varicocele and apparently normal seminogram, and also to study the role of spermatozoal fractalkine and its receptor (CX3CR1) gene expression as a marker of spermatozoa inflammatory response.

Methods

This study included 80 patients with subclinical varicocele (45 fertile and 35 infertile) and 45 age-matched fertile volunteers. In semen samples, fractalkine and CX3CR1 gene expression were investigated by qRT-PCR. Moreover, seminal plasma malondialdehyde (MDA) and total antioxidant capacity (TAC) were measured.

Results

There are significant decrease in semen quality and significant increase in seminal leucocytes count in subclinical varicocele. Our results show a significant increase in MDA and TAC levels, DNA fragmentation, and expression levels of fractalkine and its receptor (CX3CR1) in subclinical varicocele groups.

Conclusion

Subclinical varicocele induces seminal and spermatozoal subclinical inflammatory response in the form of low-level leucospermia and increased mRNA expression of the fractalkine signaling pathway, leading to increased spermatozoal ROS production, oxidative stress, and DNA fragmentation. These could cooperate in the pathogenesis of delayed fertility in males with subclinical varicocele.

Y chromosome microdeletions and varicocele as aetiological factors of male infertility: A cross-sectional study

The pathogenic mechanisms by which varicocele disrupt spermatogenesis are not clearly understood. Over 30% of male infertility cases resulting from spermatogenic problems are associated with genetic abnormalities, and Y chromosome microdeletions are the second most frequent genetic cause. Here, we aimed to evaluate the frequency of Y chromosome microdeletion in infertile men with varicocele. A cross-sectional study comprising 51 infertile men with varicocele presenting spermatogenesis failures was performed. Y chromosome microdeletion research was made using polymerase chain reaction. Of the 51 men with infertility and varicocele, 35.3% (18/51) had nonobstructive azoospermia and 64.7% had severe oligozoospermia. Y chromosome microdeletion was found in two cases (3.9%): one patient had nonobstructive azoospermia and complete microdeletion of the AZFb and AZFc regions, and another patient had severe oligozoospermia and complete microdeletion of the AZFc region. Although in recent years, a genetic aetiology related to Y chromosome microdeletions has become a major cause of infertility in males with spermatogenesis failures, in this study, the varicocele was the clinical cause of seminal abnormalities that could lead to infertility, suggesting that both varicocele and Y chromosome microdeletion aetiologies can present, alone or combined, as factors of male infertility.

JG. Semen parameters in men with varicocele: DNA fragmentation, chromatin packaging, mitochondrial membrane potential, and apoptosis

OBJECTIVE

To evaluate varicocele effects on conventional semen parameters: sperm DNA fragmentation, chromatin packaging, mitochondrial membrane potential (MMP) and sperm apoptosis.

METHODS

A cross-sectional study was carried out with semen samples from 2,399 men of couples who attended an infertility clinic. A total of 16.3% (391/2399) of the men were diagnosed with varicocele by a urologist.

RESULTS

A regression analysis revealed that the percentages of sperm with DNA fragmentation, abnormal chromatin packaging, and abnormal MMP were significantly increased in individuals with varicocele, when compared to men without varicocele. Apoptosis was not influenced by varicocele. Conventional semen parameters were significantly worse in individuals with the disease. On the other hand, in men with varicocele, Spearman's correlation demonstrated that early apoptosis and abnormal MMP showed a positive and significant correlation with sperm DNA fragmentation.

CONCLUSION

Men with varicocele had worse semen parameters, including increased levels of sperm DNA fragmentation, inactive mitochondria, and abnormal chromatin packaging. These changes are possible causes of infertility in individuals with varicocele.

Impact of varicocelectomy on the proteome profile of testicular tissues of rats with varicocele

Varicocele (VC) is a common cause of male infertility, but the molecular mechanisms involved in its pathogenesis are unknown. We investigated the impact of varicocelectomy (VCT) on proteome profiles in testicular tissues of rats with VC, and analysed associated target genes and signalling pathways. Sixty male rats with VC were divided into two groups: control (n = 30), and VCT (n = 30). Tissues were collected 4 weeks after sham or VCT surgery. Matrix-assisted laser desorption/ionisation time-of-flight/time-of-flight mass spectrometry (MALDI-TOF/TOF MS) was used to analyse the comparative proteome profiles. Kyoto Encyclopaedia of Genes and Genomes (KEGG) Orthology-Based Annotation System was used for bioinformatic analysis. Fifteen proteins were differentially expressed between control and VCT groups. These differentially expressed proteins are associated with several specific cellular processes associated with the pathogenesis of testicular growth arrest associated with VC. Furthermore, the evaluation by transmission electron micrograph showed that VCT could decrease apoptosis of spermatogenic cells in rats. Understanding such molecular pathways might provide physicians with a better insight into VC and with potential targets for treatment.

Comparative Expression Analysis of HSP70, HSP90, IL-4, TNF, KITLG and KIT-receptor Gene between Varicocele-Induced and Non-Varicocele Testes of Dog

Background

This study was designed to create an experimental varicocele model by a simple surgical procedure in dog with minimum invasion and to investigate the effect of varicocele-induced infertility on the expression of six related genes (HSP90, HSP70, IL-4, TNF, KITLG and KIT receptor).

Materials and Methods

In this experimental study, the proximal part of the pampini-form plexus of dog testes was partially occluded without abdominal incision which was confirmed by venographic examination. To evaluate varicocele in its acute form, dogs were castrated after 15 days and testes were dissected. Histopathologic evaluation was undertaken and the relative expression of the six genes was assessed by quantitative realtime polymerase chain reaction (PCR).

Results

Microscopic changes showed tubule degeneration. The Johnson score was significantly decreased in the varicocele testes when compared with non-varicocele testes. Expressions of HSP90, TNF, KITLG and the KIT-receptor gene were significantly downregulated (P=0.029, 0.047, 0.004 and 0.035 respectively) in varicocele-induced testes while HSP70 was upregulated (P=0.018). IL-4 did not show differential expression (P=0.377).

Conclusion

We conclude that partial occlusion of the proximal part of the pampiniform plexus induces varicocele in the testis of dog. Differential expression of the mentioned genes may be responsible for the pathophysiology of varicocele and related subfertility.

Varicoceles affect semen quality of infertile men in Southern China: A cross-sectional study of 5447 cases

The association of varicoceles with infertility is well established, but the exact effect of varicoceles on semen quality among patients with infertility is still poorly known. The study aimed to examine the prevalence of varicoceles among Chinese men with infertility and to examine the factors associated with semen quality.This was a cross-sectional study of 5447 male patients treated for infertility at the Affiliated Hospital of Guangdong Medical University from October 2012 to December 2015. The patients were divided on the basis of the presence of varicoceles. Examinations of the amount of semen and sperm morphology were performed according to seminal parameter detection methods recommended by the World Health Organization.Patients with varicoceles (n = 1429/5447, 26.2%) were slightly younger (P = .046), and had smaller testis (P = .019), higher frequency of abnormal epididymis (P < .001), slightly shorter infertility duration (P = .046), and lower frequency of smokers (P = .012). There was no difference in the distribution of occupations (P = .777). Using multiple linear regression analysis, varicoceles were shown to be independently associated with semen volume [B = -0.153, 95% confidence interval (95% CI): -0.245 to -0.062, P = .001], sperm concentration (B = 9.633, 95% CI: 7.152-12.114, P < .001), proportion of sperms with normal morphology (B = 0.951, 95% CI: 0.623-1.278, P < .001), motility (B = 3.835, 95% CI: 2.675, 4.995, P < .001), total sperm count (B = 22.481, 95% CI: 13.333-31.629, P < .001), and forward movement sperm count (B = 15.553, 95% CI: 9.777-21.329, P < .001). Varicoceles were present in 26% of Chinese male patients with infertility.Varicoceles were independently associated with sperm volume, sperm concentration, proportion of sperms with normal morphology, motility, total sperm count, and forward movement sperm count.

Genetics and epigenetics of varicocele pathophysiology: an overview

Varicocele is found in approximately 20% of adults and adolescents and in 19-41% of men seeking treatment for infertility. It is associated with a decrease in sperm count as well as sperm motility and morphology. The currently accepted description of the pathophysiology of varicocele does not explain all its clinical manifestations; therefore, other factors such as genetic and epigenetic changes, associated with the environment, might be involved in causing infertility and decrease in sperm quality. It has been reported that the varicocele-induced deterioration of testicular function is progressive and interferes with fertility; hence, early and efficient assessment of the genetic manifestations in patients would be important for developing future medical interventions. Chromosomal disorders, mutations, polymorphisms, changes in gene expression, and epigenetic changes have all been reported to be associated with varicocele. Several studies are underway to unravel the genetic basis of this disease, as it is important to understand the origin and the aggravating factors to ensure appropriate guidance and intervention. Here, we review the available literature regarding the genetic and epigenetic changes associated with varicocele, and how these alterations are related to the different clinical manifestations of the disease.

Varicocele management in the era of in vitro fertilization/intracytoplasmic sperm injection

Varicocele is the most common surgically treatable cause of male infertility, and often results in alterations in semen parameters, sperm DNA damage, and changes to the seminal milieu. Varicocele repair can result in improvement in these parameters in the majority of men with clinical varicocele; data supporting repair in men with subclinical varicocele are less definitive. In couples seeking fertility using assisted reproductive technologies (ARTs), varicocele repair may offer improvement in semen parameters and sperm health that can increase the likelihood of successful fertilization using techniques such as in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI), or may decrease the level of ART needed to achieve successful pregnancy. Male infertility is an indicator of general male health, and evaluation of the infertile male with an eye toward future health can facilitate optimal screening and treatment of these men. Furthermore, varicocele may represent a progressive lesion, offering an argument for its repair, although this is currently unclear.

Proteomic profile of seminal plasma in adolescents and adults with treated and untreated varicocele

Varicocele, the most important treatable cause of male infertility, is present in 15% of adult males, 35% of men with primary infertility, and 80% of men with secondary infertility. On the other hand, 80% of these men will not present infertility. Therefore, there is a need to differentiate a varicocele that is exerting a deleterious effect that is treatable from a “silent” varicocele. Despite the growing evidence of the cellular effects of varicocele, its underlying molecular mechanisms are still eluding. Proteomics has become a promising area to determine the reproductive biology of semen as well as to improve diagnosis of male infertility. This review aims to discuss the state-of-art in seminal plasma proteomics in patients with varicocele to discuss the challenges in undertaking these studies, as well as the future outlook derived from the growing body of evidence on the seminal proteome.

The varicocele: diagnostic dilemmas, therapeutic challenges and future perspectives

A varicocele is defined as the abnormal dilation of the internal testicular vein and pampiniform venus plexus within the spermatic cord. If a semen analysis is not obtained from the adolescent male, in the absence of other symptoms, the main clinical indication used by many urologists to recommend repair is testicular atrophy. The varicocele may result in testicular damage in some males causing testicular atrophy with impaired sperm production and decreased Leydig cell function, while in other males the varicocele may seemingly cause no ill effects. In adult men, varicoceles are frequently present and surgically correctable, yet the measurable benefits of surgical repair are slight according to a Cochrane review. While occurring more commonly in infertile men than fertile men, only 20% of men with a documented varicocele will suffer from fertility problems. Most varicoceles found in adolescents are detected during a routine medical examination, and it is difficult to predict which adolescent presenting with a varicocele will ultimately show diminished testicular function in adolescence or adulthood. As in adults, the mainstay of treatment for varicocele in adolescents is surgical correction. However, unlike an adult varicocelectomy (the microsurgical approach is the most common), treatment for an adolescent varicocele is more often laparoscopic. Nevertheless, the goals of treatment are the same in the adolescent and adult patients. Controversy remains as to which patients to treat, when to initiate the treatment, and what type of treatment is the best. This review will present the current understanding of the etiology, diagnosis and treatment of the adolescent varicocele.

Proteomic signatures of infertile men with clinical varicocele and their validation studies reveal mitochondrial dysfunction leading to infertility

To study the major differences in the distribution of spermatozoa proteins in infertile men with varicocele by comparative proteomics and validation of their level of expression. The study-specific estimates for each varicocele outcome were combined to identify the proteins involved in varicocele-associated infertility in men irrespective of stage and laterality of their clinical varicocele. Expression levels of 5 key proteins (PKAR1A, AK7, CCT6B, HSPA2, and ODF2) involved in stress response and sperm function including molecular chaperones were validated by Western blotting. Ninety-nine proteins were differentially expressed in the varicocele group. Over 87% of the DEP involved in major energy metabolism and key sperm functions were underexpressed in the varicocele group. Key protein functions affected in the varicocele group were spermatogenesis, sperm motility, and mitochondrial dysfunction, which were further validated by Western blotting, corroborating the proteomics analysis. Varicocele is essentially a state of energy deprivation, hypoxia, and hyperthermia due to impaired blood supply, which is corroborated by down-regulation of lipid metabolism, mitochondrial electron transport chain, and Krebs cycle enzymes. To corroborate the proteomic analysis, expression of the 5 identified proteins of interest was validated by Western blotting. This study contributes toward establishing a biomarker “fingerprint” to assess sperm quality on the basis of molecular parameters.

Spermatozoa protein alterations in infertile men with bilateral varicocele

Among infertile men, a diagnosis of unilateral varicocele is made in 90% of varicocele cases and bilateral in the remaining varicocele cases. However, there are reports of under-diagnosis of bilateral varicocele among infertile men and that its prevalence is greater than 10%. In this prospective study, we aimed to examine the differentially expressed proteins (DEP) extracted from spermatozoa cells of patients with bilateral varicocele and fertile donors. Subjects consisted of 17 men diagnosed with bilateral varicocele and 10 proven fertile men as healthy controls. Using the LTQ-orbitrap elite hybrid mass spectrometry system, proteomic analysis was done on pooled samples from 3 patients with bilateral varicocele and 5 fertile men. From these samples, 73 DEP were identified of which 58 proteins were differentially expressed, with 7 proteins unique to the bilateral varicocele group and 8 proteins to the fertile control group. Majority of the DEPs were observed to be associated with metabolic processes, stress responses, oxidoreductase activity, enzyme regulation, and immune system processes. Seven DEP were involved in sperm function such as capacitation, motility, and sperm-zona binding. Proteins TEKT3 and TCP11 were validated by Western blot analysis and may serve as potential biomarkers for bilateral varicocele. In this study, we have demonstrated for the first time the presence of DEP and identified proteins with distinct reproductive functions which are altered in infertile men with bilateral varicocele. Functional proteomic profiling provides insight into the mechanistic implications of bilateral varicocele-associated male infertility.