The effect of varicocele on seminal plasma and serum inhibin-B levels in adolescent and adult men

Seminal exosomal miR-210-3p as a potential marker of Sertoli cell damage in Varicocele

BACKGROUND

Varicocoele-associated stressors, such as hypoxia and heat, can damage cell function and viability, and some exosomal biomarkers released from impaired cells may reflect the cell status in testis.

OBJECTIVES

To find if seminal exosomal microRNAs can reflect the Sertoli cell function in varicocoele.

MATERIALS AND METHODS

Experimental left varicocoele rat model was established (n = 24), and patients with different grades of varicocoele (n = 104) were enrolled. Primary rat Sertoli cells were isolated with enzymatic hydrolysis. Exosomes were isolated from primary rat Sertoli cells, rat epididymis tissue, and human seminal plasma with polymer-based precipitation method. Exosomal microRNAs were quantified with qPCR. Inhibin-B was detected with enzyme immunoassay. The correlation analysis between microRNA and inhibin-B was evaluated with Spearman's correlation.

RESULTS

We screened 12 previously reported hypoxia-responsive microRNAs in the primary rat Sertoli cells and found that 4 exosomal microRNAs increased significantly in response to in vitro hypoxia treatment (P < .05). Of the 4 microRNAs, only miR-210-3p was upregulated in the rats with experimental varicocoele (P < .01). In the patients with varicocoele, we found that seminal exosomal miR-210-3p significantly increased in patients with grade II and III varicocoele (P < .01), and miR-210-3p negatively correlated with sperm count (P < .01) and seminal inhibin-B expression (r = -0.39, P < .01). For the 30 patients with microsurgical varicocelectomy, the operation notably decreased miR-210-3p (P < .01).

DISCUSSION AND CONCLUSION

Seminal exosomal miR-210-3p may be a novel, sensitive, and non-invasive biomarker of Sertoli cell damage in varicocoele.

Zeta and hyaluronic acid assessments, novel sperm selection procedures, in animal model for male infertility

Considering varicocele (VCL)-induced severe, progressive DNA damage, histone-protamine anomalies and low sperm production, in the current study, the experimental VCL was induced and the efficiency of hyaluronic acid (HA)-binding method (HABM) and zeta preparation procedure (ZPP) in selection of appropriate spermatozoa was compared with those spermatozoa from intact animals. Following 2 and 4 months, the histological alterations in testicular tissue, sperm count and viability were assessed to prove the VCL condition. The spermatozoa were undergone simple wash, HABM and ZPP. The chromatin condensation, active caspase-3 expression, DNA fragmentation and apoptosis index were analysed after applying selection techniques and compared with the spermatozoa from intact and VCL-induced animals, which were undergone a simple wash. Observations showed that both HABM and ZPP effectively prepared the spermatozoa with higher chromatin condensation and lower DNA damage. Meanwhile, the ZPP exerted a more preferable effect by preparing the spermatozoa with higher chromatin condensation, and lower caspase-3 expression, and DNA disintegrity versus the HABM, especially after 4 months. In conclusion, ZPP seems to exert much more reliable efficiency in selecting appropriate spermatozoa for ICSI processes, while more studies are needed to find out which one is more useful in the clinical assisted reproductive technique (ART) process.

Adolescent varicocoele management controversies

Varicocoele is defined as excessive dilatation of the pampiniform venous plexus of the spermatic cord. Varicocoele frequently appears during early puberty and is recognized to be the most common surgically correctable cause of male infertility. However, the actual incidence in adolescents, pathophysiology and the association with male factor infertility all remain somewhat controversial. The most accurate diagnostic technique for identifying young men who will benefit from surgical treatment has yet to be established. Observations of testicular asymmetry and deteriorating semen quality helped establish current guidelines and recommendations for surgical treatment. Further studies, comparing observation with surgical intervention, are needed to refine the current indications for varicocoele repair in the adolescent male.

[Varicocele in adolescents]

Testicular varicocele is present in 15 % of adolescent boys. The very impact of this pathology and who will be at risk of developing into infertility remains unclear. Research on the pathophysiology, results of surgical or radiological interventions and potential predictors for long-term impairment of spermatogenesis and thus fertility is still ongoing. Indications for treatment are mainly based on differences in testicular volumes as semen parameters are most often not available; however, whether testicular volume is a valuable prognostic parameter for later fertility remains questionable. Approximately 50 % of adolescent patients with varicocele experience spontaneous increase of testicular volume without any intervention.

Serum inhibin B levels before and after varicocelectomy in early adolescence

BACKGROUND

Whereas no clear relationship has been observed between varicocelectomy and serum inhibin B levels in men, in adolescents comparison between inhibin B levels before and after varicocelectomy is lacking.

AIM

To evaluate the effect of varicocele surgical treatment on inhibin B levels in adolescents at the beginning of puberty compared to a group of healthy adolescents.

SUBJECTS AND METHODS

We studied 28 adolescents in Tanner 2 pubertal stage with a grade III left-sided varicocele (patients) compared to 13 age and pubertal stage-matched healthy adolescents (controls). All patients underwent blood tests to determine serum inhibin B levels before and 6 months after varicocelectomy by Palomo procedure. For comparison we investigated inhibin B levels in controls and repeated this test 6 months later. Testicular ultrasound was performed for patients only.

RESULTS

Baseline inhibin B concentrations of patients and controls were 109.90 ± 40.26 and 109.33 ± 38.34 pg/ml, respectively. No significant changes were observed in patients' inhibin B concentrations after varicocelectomy (116.00 ± 42.65 pg/ml), or in controls during the 6 months' follow-up (99.12 ± 30.09 pg/ml). Doppler examination after treatment shows a complete resolution of varicocele in all the patients without alterations in testicular parenchyma.

CONCLUSIONS

Varicocelectomy performed on adolescents at T2 pubertal stage might be useful to avoid alteration in inhibin B production and consequently in testicular function. Further studies are necessary to confirm the prognostic value of inhibin B levels and the benefit of early varicocelectomy in preserving the fertility of these adolescents.

Treatment strategy for the adolescent varicocele

A varicocele is a dilatation of the testicular vein and the pampiniform venous plexus within the spermatic cord. Although rare in pediatric populations, the prevalence of varicoceles markedly increases with pubertal development. Varicoceles are progressive lesions that may hinder testicular growth and function over time and are the most common and correctable cause of male infertility. Approximately 40% of men with primary infertility have a varicocele, and more than half of them experience improvements in semen parameters after varicocelectomy. The decision to treat adolescents with varicocele is a controversial one. The task for pediatricians and urologists is to identify those adolescents who are at greatest risk for infertility in adulthood, in an effort to offer early surgical intervention to those most likely to benefit.