Ubiquitin-specific protease 26 (USP26) is an X-linked gene exclusively expressed in the testis and codes for the USP26, a peptidase enzyme that belongs to the deubiquitinating enzyme family. Recent studies have indicated that mutations in USP26 affect spermatogenesis and are associated with male infertility in humans and mice. However, the exact role of USP26 in spermatogenesis and how it affects male reproduction remains unknown. In this study, we generated a conventional Usp26 knockout mouse model and found that deletion of Usp26 in male mice (Usp26−/Y) leads to significantly reduced pup numbers per litter and significantly increased intervals between two consecutive offspring. We also found that the serum follicle stimulating hormone and testosterone levels of adult Usp26−/Y mice were significantly decreased compared to those of Usp26+/Y mice. Histological examination results showed that Usp26−/Y mice had significantly increased percentage of abnormal seminiferous tubules at different ages. Flow cytometry results exhibited that Usp26−/Y mice had significantly reduced percentage of mature haploid cells in the testes compared to Usp26+/Y mice. Sperm counts in epididymis were also significantly declined in Usp26−/Y mice compared to those in Usp26+/Y mice. Immunohistochemistry and immunofluorescence staining and immunoprecipitation analysis results showed that USP26 and androgen receptor were co-localized in mouse testicular cells at different ages and they both had physiological interactions. All these results demonstrated that the loss of Usp26 affects spermatogenesis and hormone secretion and causes male subfertility. Our study also provides the evidence on the interactions between USP26 and androgen receptor in mouse testis, whereby pointing to a potential mechanism.

Background:The worsening of semen quality, due to the application of Wi-Fi, can be ameliorated by Vitamin E. This study aimed to demonstrate whether a moderate dose of trolox, a new Vitamin E, inhibits oxidative damage on sperms in vitro after exposure to Wi-Fi radiation.Methods:Each of the twenty qualified semen, gathered from June to October 2014 in eugenics clinic, was separated into four aliquots, including sham, Wi-Fi-exposed, Wi-Fi plus 5 mmol/L trolox, and Wi-Fi plus 10 mmol/L trolox groups. At 0 min, all baseline parameters of the 20 samples were measured in sequence. Reactive oxygen species, glutathione, and superoxide dismutase were evaluated in the four aliquots at 45 and 90 min, as were sperm DNA fragments, sperm mitochondrial potential, relative amplification of sperm mitochondrial DNA, sperm vitality, and progressive and immotility sperm. The parameters were analyzed by one-way analysis of variance and Tukey's posttest.Results:Among Wi-Fi plus 5 mmol/L trolox, Wi-Fi-exposed and Wi-Fi plus 10 mmol/L trolox groups, reactive oxygen species levels (45 min: 3.80 ± 0.41 RLU·10−6·ml−1 vs. 7.50 ± 0.35 RLU·10−6·ml−1 vs. 6.70 ± 0.47 RLU·10−6·ml−1, P < 0.001; 90 min: 5.40 ± 0.21 RLU·10−6·ml−1 vs. 10.10 ± 0.31 RLU·10−6·ml−1 vs. 7.00 ± 0.42 RLU·10−6·ml−1, P < 0.001, respectively), percentages of tail DNA (45 min: 16.8 ± 2.0% vs. 31.9 ± 2.5% vs. 61.3 ± 1.6%, P < 0.001; 90 min: 19.7 ± 1.5% vs. 73.7 ± 1.3% vs. 73.1 ± 1.1%, P < 0.001, respectively), 8-hydroxy-2’-deoxyguanosine (45 min: 51.89 ± 1.46 pg/ml vs. 104.89 ± 2.19 pg/ml vs. 106.11 ± 1.81 pg/ml, P = 0.012; 90 min: 79.96 ± 1.73 pg/ml vs. 141.73 ± 2.90 pg/ml vs. 139.06 ± 2.79 pg/ml; P < 0.001), and percentages of immotility sperm (45 min: 27.7 ± 2.7% vs. 41.7 ± 2.2% vs. 41.7 ± 2.5%; 90 min: 29.9 ± 3.3% vs. 58.9 ± 4.0% vs. 63.1 ± 4.0%; all P < 0.001) were lowest, and glutathione peroxidase (45 min: 60.50 ± 1.54 U/ml vs. 37.09 ± 1.77 U/ml vs. 28.18 ± 1.06 U/ml; 90 min: 44.61 ± 1.23 U/ml vs. 16.86 ± 0.93 U/ml vs. 29.94 ± 1.56 U/ml; all P < 0.001), percentages of head DNA (45 min: 83.2 ± 2.0% vs. 68.2 ± 2.5% vs. 38.8 ± 1.6%; 90 min: 80.3 ± 1.5% vs. 26.3 ± 1.3% vs. 26.9 ± 1.1%; all P < 0.001), percentages of sperm vitality (45 min: 89.5 ± 1.6% vs. 70.7 ± 3.1% vs. 57.7 ± 2.4%; 90 min: 80.8 ± 2.2% vs. 40.4 ± 4.0% vs. 34.7 ± 3.9%; all P < 0.001), and progressive sperm (45 min: 69.3 ± 2.7% vs. 55.8 ± 2.2% vs. 55.4 ± 2.5%; 90 min: 67.2 ± 3.3% vs. 38.2 ± 4.0% vs. 33.9 ± 4.0%; all P < 0.001) were highest in Wi-Fi plus 5 mmol/L trolox group at 45 and 90 min, respectively. Other parameters were not affected, while the sham group maintained the baseline.Conclusion:This study found that 5 mmol/L trolox protected the Wi-Fi-exposed semen in vitro from the damage of electromagnetic radiation-induced oxidative stress.

ObjectiveThe recent advent of flow cytometry (FCM), coupled with fluorescent dyes, has been successfully applied to assess mitochondrial function. The aim of this study was to investigate the feasibility and clinical significance of detecting sperm mitochondrial function and to evaluate sperm mitochondrial function by using Rhodamine 123/propidium (Rh123/PI) dual fluorescent staining and FCM in asthenospermia and oligoasthenozoospermia.MethodsTwenty-five fertile men (with normal sperm parameters) and 230 infertile patients were examined. Fifty-five patients of the above 230 patients were selected for idiopathic infertility samples and were divided into two groups: asthenospermia (n = 30) and oligoasthenozoospermia (n = 25). Rh123/PI dual fluorescent staining and FCM were carried out to examine sperm mitochondrial function.ResultsSignificant differences were found between the normal and abnormal semen samples (P < 0.05) when Rh123+/PI−, Rh123−/PI+ and Rh123−/PI− sperm were examined by FCM, but there was no significant difference between the asthenospermia (P = 0.469) and oligoasthenozoospermia group (P = 0.950) when Rh123+/PI− and Rh123−/PI+ sperm were then examined; however, a significant difference was found between the 2 groups (P = 0.003) when Rh123−/PI− sperm were examined. There was no correlation between Rh123−/PI− sperm and semen parameters in the normal group, but there was a significant negative correlation between the sperm concentration and Rh123−/PI− sperm in asthenospermia and oligoasthenozoospermia patients (r = -0.509, -0.660; P = 0.018, 0.038).ConclusionRh123/PI dual fluorescent staining and FCM can provide reliable information to assess the quality of sperm and reveal differences in mitochondrial membrane potential in asthenospermia and oligoasthenozoospermia.

Abstract:Tamoxifen citrate, as the first line of treatment for infertile men with idiopathic oligozoospermia, was proposed by the World Health Organization (WHO), and testosterone undecanoate has shown benefits in semen values. Our objective was to assess the effectiveness of treatment with tamoxifen citrate and testosterone undecanoate in infertile men with idiopathic oligozoospermia, and whether the results would be affected by polymorphisms of CYP2D6*10. A total of 230 infertile men and 147 controls were included in the study. Patients were treated with tamoxifen citrate and testosterone undecanoate. Sex hormone, sperm parameters, and incidence of spontaneous pregnancy were detected. There were no significant differences between the control and patient groups with respect to CYP2D6*10 genotype frequencies (P>0.05). The follicle-stimulation hormone (FSH), luteinizing hormone (LH), and testosterone (T) levels were raised, and sperm concentration and motility were increased at 3 months and became significant at 6 months, and they were higher in the wild-type allele (C/C) than in the heterozygous variant allele (C/T) or homozygous variant allele (T/T) subgroups (P<0.05). In addition, the percentage of normal morphology was raised at 6 months, and represented the highest percentage in the C/C subgroup (P<0.05). The incidence of spontaneous pregnancy in the C/C subgroup was higher than that in the C/T or T/T subgroups (P<0.01). This study showed that the CYP2D6*10 variant genotype demonstrated worse clinical effects in infertile men with idiopathic oligozoospermia.

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