Sperm mitochondrial DNA copy number mediates the association between seminal plasma selenium concentrations and semen quality among healthy men.

Selenium (Se) is essential for successful male reproduction. However, the association of Se status with human semen quality remains controversial and the underlying mechanisms are poorly understood. We measured seminal plasma Se concentrations, sperm mitochondrial DNA copy number (mtDNAcn), and sperm quality parameters among healthy Chinese men screened as potential sperm donors. Linear mixed-effects models were used to investigate the associations of within-subject pooled seminal plasma Se concentrations (n = 1159) with repeated sperm quality parameters (n = 5617); mediation analyses were applied to evaluate the mediating role of sperm mtDNAcn (n = 989). Seminal plasma Se concentrations were positively associated with sperm concentration and total count (both P for trend < 0.001). In adjusted models, men in the top vs. bottom quartiles of seminal plasma Se concentrations had 70.1 % (95 % CI: 53.3 %, 88.9 %) and 59.1 % (95 % CI: 40.5 %, 80.2 %) higher sperm concentration and total count, respectively. Meanwhile, we observed inverse associations between seminal plasma Se concentrations and sperm mtDNAcn, and between sperm mtDNAcn and sperm motility, concentration, and total count (all P for trend < 0.05). Mediation analyses suggested that sperm mtDNAcn mediated 19.7 % (95 % CI: 15.9 %, 25.3 %) and 23.1 % (95 % CI: 17.4 %, 33.4 %) of the associations between seminal plasma Se concentrations and sperm concentration and total count, respectively. Our findings suggest that Se is essential for male spermatogenesis, potentially by affecting sperm mtDNAcn.

Association between tea consumption and semen quality among 1385 healthy Chinese men.

Information on the association between tea drinking and semen quality is limited. Little is reported on whether tea drinking is benefit to sperm quality. This cross-sectional and longitudinal study was conducted between April 2017 and July 2018. Participants were healthy men who were screened as potential sperm donors recruited at the Hubei Province Human Sperm Bank of China. A structured questionnaires containing sociodemographic information, daily habits, sperm collection-related information was completed for each participant at interview. Repeated semen samples were taken to examine the sperm parameters, including sperm volume, sperm concentration, sperm count, progressive motility, and total motility. A total of 1385 men with 6466 sperm samples were included in this study. Two groups were compared: tea drinking men (389, 28.1%) and non-tea drinking men (996, 71.9%). Compared with subjects who never drink tea, the analyses showed that sperm concentration and total sperm count were higher in tea-consuming subjects. A 10-year period or more duration of tea drinking significantly increased semen concentrations by 16.27% (P < 0.05). Sperm concentration was increased in subjects with a frequency of tea drinking of 3 days or more per week (P < 0.05) or, among men who were occasional alcohol drinkers, when tea concentration was weak (P < 0.05). No evidence of trend effects (P for trend > 0.05) or interaction effects (P for interaction > 0.05) between tea consumption and sperm quality, respectively. Our findings provide evidence that tea drinking may improve male reproductive health. Long-term, frequent, weak tea drinking tends to increase sperm quality among men with low BMI or health-related behaviors like smoking or alcohol intake.

Identifying windows of susceptibility to essential elements for semen quality among 1428 healthy men screened as potential sperm donors.

BACKGROUND: Essential elements such as iron (Fe), cobalt (Co), copper (Cu), zinc (Zn), selenium (Se), rubidium (Rb), strontium (Sr), and molybdenum (Mo) are necessary for reproductive health. However, their associations with human semen quality remain inconclusive. OBJECTIVES: To investigate the associations of urinary Fe, Co, Cu, Zn, Se, Rb, Sr, and Mo concentrations with semen quality in healthy men screened as potential sperm donors and identify critical windows of susceptibility. METHODS: 1428 healthy men provided 3766 urine and 6527 semen samples, which were measured for urinary essential element concentrations and sperm quality parameters, respectively. Linear mixed models and cubic spline curves were used to evaluate associations between urinary essential elements and semen quality. Multiple informant models were used to identify potential critical windows of susceptibility. RESULTS: Linear mixed models and cubic spline curves showed positive dose-response relationships between urinary Zn and sperm concentration and total count and between urinary Mo and total sperm count [all False Discovery Rate (FDR) adjusted p-value for trend < 0.05]. In the multiple-element linear mixed models, the men in the highest versus lowest quartiles of urinary Zn and Mo had a higher sperm concentration of 17.5% (95% CI: 2.8%, 34.2%; p-value for trend = 0.006) and total sperm count of 18.3% (95% CI: 1.4%, 38.0%; p-value for trend = 0.027), respectively. Urinary Zn was also positively associated with total sperm count in a dose-dependent manner (p-value for trend = 0.036), though the percentile difference in total sperm count between men in the highest and lowest quartile was not statistically significant (16.4%, 95% CI: -1.7%, 37.9%). These associations appeared to be stronger when urinary Zn and Mo were measured at 0-9 days before the date of semen examination (i.e., corresponding to epididymal storage). CONCLUSIONS: Higher urinary Zn and Mo, particularly during the period of epididymal storage, were associated with greater sperm production.

Supplementation of vitamin C promotes early germ cell specification from human embryonic stem cells.

BACKGROUND: As the precursors of sperm and eggs, human primordial germ cells (hPGCs) emerge as early as weeks 2 to 3 of post-implantation development. Recently, robust hPGC induction models have been established in vitro with different protocols, but global 5mC/5hmC epigenetic reprogramming is not initiated in vitro. Previous studies found that vitamin C can enhance Tet (ten-eleven translocation) enzyme expression and improve 5hmC level in cells. But the effect of vitamin C supplementation on hPGC in vitro induction is still unknown. METHODS: We generated a gene-edited human embryonic stem cell (hESC) line carrying a BLIMP1-mkate2 reporter by CRISPR/Cas9 technology and used flow cytometry to optimize the PGC differentiation protocol; meanwhile, the expression of PGC genes (BLIMP1, TFAP2C, SOX17, OCT4) was evaluated by qRT-PCR. When different concentrations of vitamin C were added to the induction medium, the percentage of hPGCLCs (hPGC-like cells) was analyzed by flow cytometry; dot blot and ELISA were used to detect the levels of 5hmC and 5mC. The expression of TET enzymes was also evaluated by qRT-PCR. RESULTS: We optimized the PGC differentiation protocol with the BLIMP1-mkate reporter hESCs, and the efficiency of PGC induction in vitro can be improved to 30~40%. When 50 µg/mL vitamin C was added, the derived hPGCLCs not only upregulated the expression of key genes involved in human early germ cell development such as NANOS3, TFAP2C, BLIMP1, and SOX17, but also increased the levels of 5hmC and TET enzymes. CONCLUSIONS: Taken together, supplementation of vitamin C can promote the in vitro induction of hPGCLCs from hESCs, which might be related to vitamin C-mediated epigenetic regulations during the differentiation process.

Effect of vitamin D supplementation on polycystic ovary syndrome: A systematic review and meta-analysis of randomized controlled trials.

OBJECTIVE: To evaluate the effect of vitamin D supplementation on patients with PCOS. METHODS: We performed a literature search in database and identified all of the RCTs published before December 2015 that compared the effect of vitamin D supplementation with placebo or metformin in PCOS patients. MAIN RESULTS: Nine out of 463 identified studies were included, involving 502 women presenting with PCOS. Vitamin D supplementation had significant effect on the improvement of follicular development with a higher number of dominant follicles (OR, 2.34; 95% CI, 1.39 to 3.92). Differences in regular menstrual cycles were also observed when metformin plus vitamin D was compared with metformin alone (OR, 1.85; 95% CI, 1.01 to 3.39). CONCLUSIONS: Evidence from available RCTs suggests vitamin D supplementation may be beneficial for follicular development and menstrual cycle regulation in patients with PCOS. Additional high-quality RCTs are required to confirm the effectiveness of vitamin D on PCOS.

[Optimization of real time RT-PCR system for the quantitative estimation of CatSper1 mRNA levels in human and mouse mature spermatozoa].

OBJECTIVE: To establish and optimize a real time RT-PCR system for determining the transcript levels of CatSper1 in human and mouse mature spermatozoa containing microamount of RNA. METHODS: Total RNA of human and mouse mature spermatozoa was isolated by using TRIzol reagent and reversely transcribed to complementary DNA respectively. Primers for real time RT-PCR were designed in the homologous area of the human and mouse CatSper1 mRNAs. Human sperm complementary DNA was used as the template to the optimize the conditions for SYBR Green I real time RT-PCR, including annealing temperature, Mg2+ concentration, fluorescence measurement temperature and the ratio between forward and reverse primers. The standard curve was constructed with serial dilutions of complementary DNA from human sperm to ascertain the amplification efficiency of SYBR Green I real time PCR and to quantitate the CatSper1 mRNA levels in the human and mouse mature spermatozoa. RESULTS: The optimal conditions for real time RT-PCR, that is, annealing temperature, Mg2+ concentration and the ratio between forward and reverse primers were 63 degrees C, 3.0 mmol/L and 1:1 respectively. The fluorescence measurement temperature was 88 degrees C. The standard curves were Y = -3.402 log (X) + 25.99 and Y = -3.409 log(X) + 24.09 in the human sperm cDNA and mouse sperm cDNA as the template, with amplification efficiency of 96.8% and 96.5% respectively. The R2 value (an indicator of the quality of the fit of the standard curve to the standard data points plotted) of both standard curves was 0.998. The CatSper1 mRNA levels in the human and mouse mature spermatozoa could be determined according to the standard curve. CONCLUSION: The general RT-PCR system, by adding SYBR Green I and optimizing its conditions, could be used to quantitate the mRNA levels in both human and mouse mature spermatozoa.

[Comparison of the anti-fertility effects of four extracts from the roots of Rhynchosia volubilis Lour].

OBJECTIVE: To compare the anti-fertility effects of the four extracts from the roots of Rhynchosia volubilis Lour on male mice, that is, ethanolic extract, ethyl acetate extract, n-butanol extract and aqueous extract. METHODS: Four extracts from the roots of Rhynchosia volubilis Lour (1%, 0.1 ml/10 g), were administered orally for 11 weeks to adult male mice. The fertility and testicular function of the mice were assessed by mating tests and analyses of sperm motility in cauda epididymides and biochemical and histological indexes in the blood samples and reproductive organs. RESULTS: The four extracts, especially aqueous extract, gradually decreased the pregnancy rate of the experimental mice from the 77th day of the treatment, with an obvious reduction in the number of spermatozoa. Morphological observation of the reproductive organs by light microscopy showed that the numbers of the secondary spermatocytes and spermatids were decreased in varied degrees, and the seminiferous tubules were disarranged, while the numbers and shapes of and spermatids were decreased in varied degrees, and the seminiferous tubules were disarranged, while the numbers and shapes of spermatogonia, Sertoli cells and Leydig cells remained unchanged. CONCLUSION: The four extracts from the roots of Rhynchosia volubilis Lour all have anti-fertility effects on male mice, and that of the aqueous extract is more obvious.

[Inhibitory effect on male mouse procreation and chemical composition analysis of Rhynchosia volubilis ethyl acetate extract].

OBJECTIVE: To study the effect of Rhynchosia volubilis Lour ethyl acetate extract (RVLEAE) on male mouse procreation and analyse their chemical composition. METHOD: With the method of solvent extraction, RVLEAE was extracted and concentrated. In the experiment of mice, 80 male mice were randomly and equally divided into four groups: Normal Saline control, positive control with 0.1% triperygium wilfordii glycoside, 100 mg x kg(-1) x d(-1) RVLEAE and 400 mg x kg(-1) x d(-1) RVLEAE. Every mouse was fed with drug 0.01 mL x g(-1), once a day, ig, for eleven consecutive weeks. After two and 10 weeks, male and female mouse naturally mated for one week. The pregnancy rate, number of fetus and nonviable fetus, the viability of spermatozoon in the epididymis cauda, pathological change of testis and epididymis were observed in this experiment. In the analysis of chemical composition, RVLEAE were separated with column chromatography, and chemical compositions were identified with thinlayer chromatography, infrared chromatography and nuclear magnetic resonance. RESULT: The pregnancy rate of mice was markedly decreased. The number and viability of spermatozoon were slightly reduced in I and II after two and 10 weeks, but the pathological changes of testis and epididymis were markedly occurred. Main chemical compositions were identified as saccharide, glycosides especially analog of fucose, alcohols, and phenols. CONCLUSION: RVLEAE can inhibit the procreation of male mice, and inhibitory target tissue may be the epididymis. Active mechanism of RVLEAE may be that glycosides interfere the maturation of spermatozoon in the epididymis cauda.

[Resistant effect of water decoction of root of Crataegus cuneata on male infertility induced by GTW in rats].

OBJECTIVE: To observe the effects of water decoction of the root of Crataegus cuneata on infertility induced by multi-glucoside of Tripterygium wilfordii (GTW) in rats. METHOD: Male adult rats were randomly divided into five groups, which were treated via gastric gavage of distilled water (1 mL x kg(-1)) , solution of GTW (10 mg x kg(-1)) and three doses of water decoction of root of C. cuneata (1.8, 5.4, 18 g x kg(-1)) + GTW (10 mg x kg(-1)), respectively. 8 weeks later, GTW was stopped and the decoction and water continued for another 4 weeks. And then, all the male rats were copulated with adult female rats. The rates of pregnancy, average numbers of embryos and luteum of female rats, relative weights of reproductive organs, sperm counts, sperm motility and viability were compared among all the groups. The histology and ultrastructure of testis and epididymis were observed, while the concentrations of follicle stimulating hormone (FSH), luteinizing hormone (LH) and testostorone (T) in serum and T in testicular homogenate were detected by radioimmunoassay. RESULT: Compared with those in GTW model group, the embryo numbers, the relative weight of testis and epididymis and sperm counts and motility in C. cuneata groups were increased obviously (P < 0.05). After treatment, the morphological damages of seminiferous tubules and sperms were recovered, while concentrations of T in testicular homogenate were also significantly increased (P < 0.01). CONCLUSION: C. cuneata could relieve the reproductive lesions induced by GTW, and hence improve the uberty of the male infertile model rats.

[The effects of eucommia ulmoides oliv on catching action of diabetic rats and myelinated nerve fibers in penile tissues].

OBJECTIVE: To explore the pharmacodynamic and pathological mechanism of eucommia ulmoides oliv in improving erectile function. METHODS: Thirty male diabetic rats were randomly divided into three groups: group A (n = 10, escipient group), group B (n = 10, sildenafil group), group C (n = 10, eucommia ulmoides oliv group) and group D (n = 10, the normal control group). After gavage for four weeks, the catching behaviors of all rats were observed, and ultrastructure of myelinated nerve fibers in penile tissue was examined by transmission electron microscope. The expression of neuronal nitric oxide synthase (nNOS) in penile tissues was examined by two steps immunohistochemistry method. RESULTS: Compared with group A, catching frequency of the rats in group C was notably increased (P < 0.05) and the expression of nNOS in penile tissue was significantly (P < 0.001). The examination by transmission electron microscope showed that in the rats' penile tissue of group A, myelinated nerve fibers were irregularly arranged and partially degenerated, and myelin sheaths lamella were splited and exhibited vacuoles or network forms. In group C, there were regular arrangements of myelinated nerve fibers, in which the formation of lamella was clear. CONCLUSION: By remitting the impairement of myelinated nerve fibers and enhancing the expression of nNOS in penile tissue, eucommia ulmoides oliv can improve erectile function of diabetic rats.

[The influence of medicated serum with root of Crataegus cuneata on human sperm motility parameters in vitro].

OBJECTIVE: To study the influence of root of medicated serum with the root of Crataegus cuneata on human sperm motility in vitro. METHOD: Sperm specimens of 16 asthenospermia patients were co-incubated with the medicated serum in vitro. The sperm motility characteristics were evaluated by computer-assisted semen analysis (CASA) at 5, 15, 30, 60 min and 120 min. RESULT: Compared with the control group, the medicated serum significantly increased the sperm progressive motility in 5 and 15 min (P < 0.05), and the motility and progressive motility were both increased significantly in 60 and 120 min (P < 0.01). The excitatory effect of the medicated serum on the sperm motility exhibited in a time-dependent manner. CONCLUSION: Root of C. cuneata medicated serum can improve sperm motility of asthenospermia patients in vitro.

[Effect of eucommia ulmoides oliv on SOD activity and alpha-actin expression in the penile tissues of diabetic rats].

OBJECTIVE: To study the effect of aqueous abstract from eucommia ulmoides oliv on the activity of superoxide dismutase (SOD) and alpha-actin expression in the penile tissues of rats with diabetes mellitus (DM) in vitro. METHODS: A diabetes model was established by administration of alloxun twice to Sprague Dawley (SD) rats. Ten diabetic and 10 normal rats were randomly selected and the penile strips of each rat were divided into four equal shares and cultured in two groups, a eucommia ulmoides oliv coculture group (Group A, further dicided into 1 microg/ml, 10 microg/ml and 100 microg/ml subgroups) and a control group (Group B). Seven days later, the activity of SOD in the culture medium was detected by spectrophotometry, and the levels of micro-actin expression in the penile tissues were examined with the immunohistochemical method. RESULTS: Compared with Group B, the activity of SOD in the culture medium in athe 10 and 100 microg/ml subgroups was notably elevated (P < 0.01), and the numbers of immunoreactive positive cells of alpha-actin in the penile tissues remarkably increased (P < 0.01). CONCLUSION: The activity of SOD and alpha-actin expression in the penile tissues of diabetic rats in vitro can be increased by eucommia ulmioides oliv.

[The effect of Chinese medicine yiqihuoxuetang on T-lymphocyte subpopulation in peripheral blood of infertile men with antisperm antibodies].

OBJECTIVES: To study whether Chinese Medicine Yiqihuoxuetang(YQHXT) could inhibit antisperm antibodies in infertile men, and to explore the therapeutical mechanism of YQHXT. METHODS: Thirty infertile men with antisperm antibodies took YQHXT continuously for 60 days. Indirect immuno-fluorescence technique (IFT) was used to detect the levels of CD3, CD4, CD8 and CD4/CD8 ratio before and after treatment. RESULTS: CD4 value and CD4/CD8 ratio after treatment were significantly lower than before treatment (P < 0.05); CD8 value became significantly higher(P < 0.05). CONCLUSIONS: The results indicated that YQHXT could inhibit antisperm antibodies by keeping the balance of T-lymphocyte subpopulation in immunoinfertile men.