Testicular steroid sulfatase overexpression is associated with Leydig cell dysfunction in primary spermatogenic failure.

BACKGROUND: Decreased testosterone (T) to LH ratio and increased 17ß-estradiol (E2) serum concentrations represent a common finding among patients with severe spermatogenic failure, suggesting a concurrent Leydig cell steroidogenic dysfunction. Aromatase overexpression has been associated with increased serum and intratesticular E2 in these patients. However, it is unknown whether the sulfatase pathway contributes to the increased availability of active estrogens in patients with primary spermatogenic failure. OBJECTIVES: To assess estrogen sulfotransferase (SULT1E1) and steroid sulfatase (STS) mRNA abundance in testicular tissue of patients with Sertoli cell-only syndrome (SCOS) and normal tissues, its association with serum and intratesticular hormone levels, and to explore the mRNA and protein testicular localization of both enzymes. MATERIALS AND METHODS: Testicular tissues of 23 subjects with SCOS (cases) and 22 patients with obstructive azoospermia and normal spermatogenesis (controls) were obtained after biopsy. SULT1E1 and STS transcripts accumulation was quantified by RT-qPCR. For mRNA and protein localization, we performed RT-qPCR in Leydig cell clusters and seminiferous tubules isolated by laser-capture microdissection and immunofluorescence in testicular tissues. Serum and intratesticular hormones were measured by immunoradiometric assays. RESULTS: SULT1E1 mRNA accumulation was similar in both groups. The amount of STS mRNA was higher in cases (p = 0.007) and inversely correlated with T/LH ratio (r = -0.402; p = 0.02). Also, a near significant correlation was observed with intratesticular E2 (r = 0.329, p = 0.057), in agreement with higher intratesticular E2 in cases (p < 0.001). Strong STS immunoreaction was localized in the wall of small blood vessels but not in Leydig cells. Both SULT1E1 and STS mRNA abundance was similar in Leydig cell clusters and the tubular compartment, except for lower SUTL1E1 mRNA in the seminiferous tubules of SCOS patients (p = 0.001). CONCLUSIONS: Our results suggest that an unbalance of the STS/SULT1E1 pathway contributes to the testicular hyperestrogenic microenvironment in patients with primary spermatogenic failure and Leydig cell dysfunction.

Polymorphisms in folate-related enzyme genes in idiopathic infertile Brazilian men.

The aim of the study was to analyze the distribution of the methylenetetrahydrofolate reductase (MTHFR), methionine synthase reductase (MTRR), and methionine synthase (MTR) polymorphisms in idiopathic infertile Brazilian men and fertile men. Case-control study comprising 133 idiopathic infertile Brazilian men with nonobstructive azoospermia ([NOA] n = 55) or severe oligozoospermia ([SO] n = 78) and 173 fertile men as controls. MTHFR C677T, A1298C, and G1793A; MTRR A66G; and MTR A2756G polymorphisms were studied by quantitative polymerase chain reaction (qPCR). The results were analyzed statistically and a P value <.05 was considered significant. Single-marker analysis revealed a significant association among MTHFR C677T polymorphism and both NOA group (P = .018) and SO group (P < .001). Considering the MTHFR A1298C, MTHFR G1793A, and MTRR A66G polymorphisms, no difference was found between NOA group and SO group. Regarding the MTR A2756G polymorphism, a significant difference was found between NOA and controls, P = .017. However, statistical analysis revealed no association between SO group and controls. Combined genotypes of 3 MTHFR polymorphisms did not identify a haplotype associated with idiopathic infertility. The combinatory analysis of the 3 polymorphisms MTHFR, MTRR, and MTR did not show difference between cases and controls. The findings suggest the MTHFR C677T and MTR A2756G polymorphisms could be an important genetic factor predisposing to idiopathic infertility in Brazilian men.

Angiotensin (1-7) and its receptor Mas are expressed in the human testis: implications for male infertility.

The presence of classical components of the renin-angiotensin system has been demonstrated in the male reproductive tract, mainly in the testes and epididymis. The objective of this study was to verify the localization of angiotensin (Ang)-(1-7) and its receptor Mas in human testis. The study included 12 men with previously proven fertility submitted to orchiectomy for prostate cancer and 20 infertile men submitted to testicular biopsy for infertility work-up, comprising a subgroup with obstructive azoospermia/normal spermatogenesis (n = 8) and another with non-obstructive azoospermia and severely impaired spermatogenesis (n = 12). Testicular tissue samples were processed by immunohistochemistry and real time polymerase chain reaction. Ang-(1-7) was strongly expressed in the interstitial compartment, mainly in Leydig cells, with similar intensity in all groups evaluated. The peptide was also detected in the seminiferous tubules, but with much less intensity compared to interstitial cells. The receptor Mas was equally distributed between interstitial and tubular compartments and was found in all layers of the normal seminiferous epithelium. However, neither Ang-(1-7) nor Mas were detected in the seminiferous tubules of samples with impaired spermatogenesis. The testicular samples of infertile men with impaired spermatogenesis (non-obstructive azoospermia) expressed Mas and ACE2 mRNA at lower concentrations (fold change = 0.06 and 0.04, respectively, P < 0.05) than samples with full spermatogenesis (obstructive azoospermia). This shows, for the first time, the immunolocalization of Ang-(1-7) and its receptor Mas in testes of fertile and infertile men, and suggests that this system may be altered when spermatogenesis is severely impaired.