Semen parameters are unaffected by statin use in men evaluated for infertility.

The effects of statin use on conventional semen parameters in humans are largely unknown and have not been previously studied in subfertile men. We retrospectively reviewed data from 10,140 patients seen at our fertility clinic between 2002 and 2013 to assess the effects of statin use on semen parameters. Men who used any statins for >3 months before semen sample collection were included as cases. Data were gathered on patient age, medication use and conventional semen parameters. A total of 118 patients (126 samples) used statins for at least 3 months before semen sample collection. Data from 7698 patients (8,760 samples), who were not using any medications, were used as controls. In age-adjusted regression models, statin use was not associated with statistically significant changes in semen parameters. When used in combination with other nonspermatotoxic medications, it was associated with 0.3 ml decrease in semen volume (95% confidence interval: 0.02 to 0.58 ml, p-value = .04). In conclusion, statin use was not adversely associated with semen parameters other than semen volume in subfertile patients. These findings from our large-scale retrospective study suggest that there are no clinically relevant deleterious effects from statin use on conventional semen parameters.

Sperm DNA damage output parameters measured by the alkaline Comet assay and their importance.

The alkaline Comet assay has shown high diagnostic value to determine male reproductive health and prognostic ability to predict ART success. Here, spermatozoon was analysed in 47 fertile donors and 238 patients, including 132 couples undergoing ART [semen was collected: Group I - within 3 months of their treatment (n = 79); and Group II - 3 months prior to their treatment (n = 53)]. We introduce four Comet distribution plots (A, B1, B2 and C) by plotting the level of DNA damage (x-axis) and percentage of comets (y-axis). Fertile donors had low mean DNA damage, olive tail moment and per cent of spermatozoa with damage and increased type A plots. Comet parameters were associated with clinical pregnancies in Group I. About 66% of couples with type A distribution plot were successful after ART, whereas couples with type B1, B2 and C distribution plots achieved 56%, 44% and 33% pregnancies respectively. The efficiency of the Comet assay was due to complete decondensation process, where the compact sperm nuclear DNA (28.2 ± 0.2 µm3 ) is decondensed to ~63 µm3 (before lysis) and ~1018 µm3 (after lysis). A combinational analysis of all the Comet output parameters may provide a comprehensive evaluation of patient's reproductive health as these parameters measure different aspects of DNA damage within the spermatozoa.

The "omics" of human male infertility: integrating big data in a systems biology approach.

Spermatogenesis is a complex process in which >2300 genes are temporally and spatially regulated to form a terminally differentiated sperm cell that must maintain the ability to contribute to a totipotent embryo which can successfully differentiate into a healthy individual. This process is dependent on fidelity of the genome, epigenome, transcriptome, and proteome of the spermatogonia, supporting cells, and the resulting sperm cell. Infertility and/or disease risk may increase in the offspring if abnormalities are present. This review highlights the recent advances in our understanding of these processes in light of the "omics revolution". We briefly review each of these areas, as well as highlight areas of future study and needs to advance further.

Associations of single nucleotide polymorphisms in the Pygo2 coding sequence with idiopathic oligospermia and azoospermia.

Male infertility is often associated with a decreased sperm count. The Pygo2 gene is expressed in the elongating spermatid during chromatin remodeling; thus impairment in PYGO2 function might lead to spermatogenic arrest, sperm count reduction, and subsequent infertility. The aim of this study was to identify mutations in Pygo2 that might lead to idiopathic oligospermia and azoospermia. DNA was isolated from venous blood from 77 men with normal fertility and 195 men with idiopathic oligospermia or azoospermia. Polymerase chain reaction-sequencing analysis was performed for the three Pygo2 coding regions. Non-synonymous single nucleotide polymorphisms (SNPs) were detected and analyzed using SIFT, Polyphen-2, and Mutation Taster softwares to identify possible changes in protein structure that could affect phenotype. Pygo2 sequencing was successful for 178 patients (30 with mild or moderate oligospermia, 57 with severe oligospermia, and 91 with azoospermia). Three previously reported non-synonymous SNPs were identified in patients with azoospermia or severe oligospermic but not in those with mild or moderate oligozoopermia or normozoospermia. SNPs rs61758740 (M141I) and rs141722381 (N240I) cause the replacement of one hydrophobic or hydrophilic amino acid, respectively, with another, and SNP rs61758741 (K261E) causes the replacement of a basic amino acid with an acidic one. The software predictions demonstrated that SNP rsl41722381 would likely result in disrupted tertiary protein structure and thus could be involved in disease pathogenesis. Overall, this study demonstrated that SNPs in the coding region of Pygo2 might be one of the causative factors in idiopathic oligospermia and azoospermia, resulting in male infertility.

Hamster oocyte membrane potential and ion permeability vary with preantral cumulus cell attachment and developmental stage.

BACKGROUND: In vitro maturation of mammalian oocytes is an area of great interest due to its potential application in the treatment of infertility. The morphological and physiological changes that occur during oocyte development are poorly understood, and further studies are needed investigating the physiological changes associated with oocyte maturation. In this study we evaluated the membrane potential and the sodium/potassium permeability ratio of oocytes acutely isolated, and cumulus-oocyte complexes in metaphase II and preantral follicle stages. RESULTS: Intracellular electrical recordings revealed that cumulus-enclosed oocytes have a membrane potential significantly more negative at the preantral follicle stage than at metaphase II stage (-38.4 versus -19.7 mV, p < 0.0005). The membrane potential of the cumulus-free oocytes was not different between the preantral and metaphase II stages. The membrane potential of the cumulus cells forming preantral stage follicles was shown to be significantly different from that of the oocyte within the follicle (-28.6 versus -38.4 mV, p < 0.05). The sodium/potassium permeability measured in cumulus-enclosed oocytes at the preantral stage equaled a mean value of 0.33. The ratio was significantly lower when measured in oocytes denuded of cumulus cells or cumulus-enclosed metaphase II oocytes, 0.76, 0.79, 0.77 respectively (p < 0.001). CONCLUSIONS: These data show a change in the membrane potential and Na+/K+ permeability ratio during ooycte development from the preantral stage oocyte to the metaphase II stage. We have also demonstrated a change in the preantral oocyte membrane potential when surrounding cumulus cells are removed; either due to membrane changes or loss of cumulus cells.

Characterization of aneuploidy rates, protamine levels, ultrastructure, and functional ability of round-headed sperm from two siblings and implications for intracytoplasmic sperm injection.

OBJECTIVE: To characterize and contrast protamine levels, chromatin decondensation, chromosome aneuploidy rates, and functional ability of round-headed sperm from two brothers with round-headed sperm syndrome. DESIGN: Analysis of semen samples from siblings with round-headed sperm syndrome and comparison with semen of fertile donors. SETTING: University school of medicine and laboratories. PATIENT(S): Two infertile siblings. MAIN OUTCOME MEASURE(S): Sperm aneuploidy rates of chromosomes X, Y, 13, 18, and 21, protamine 1 and 2 (P1-P2) ratios, Western blot evaluation of protamines, and chromatin decondensation rates. Additional measures include standard semen quality parameters, electron microscopy ultrastructure evaluation, analysis of acrosome morphology, and sperm penetration rates. RESULT(S): Aneuploidy rates were significantly increased in sibling no. 1 but not in sibling no. 2. The levels of P1 and P2 were decreased in sibling no. 1, and an unusual level of protamine precursors was present. Ultrastructural differences also were observed between the siblings. CONCLUSION(S): These data indicate profound differences in sperm from two siblings with complete round-headed sperm syndrome. Multigenic defects and/or variable expression of the syndrome may be responsible for the syndrome and necessitate individual screening of affected individuals because the pattern of expression appears highly variable.

In vitro growth, maturation, fertilization, and embryonic development of oocytes from porcine preantral follicles.

This study was conducted to identify an in vitro culture system that would support intact porcine follicle growth from preantral follicle to antral stages, oocyte maturation, fertilization, and embryonic development; and to evaluate factors that influence porcine preantral follicle growth in vitro. Preantral follicles isolated from prepubertal porcine ovaries were cultured for 4 days in the presence of different concentrations of porcine serum and FSH, and with different numbers of follicles per well. A series of experiments showed that porcine antral follicles can be grown at a high frequency in vitro from healthy preantral follicles with intact theca when cultured in North Carolina State University 23 medium supplemented with 1.5 ng/ml FSH, 7.5% serum, and when cultured with three follicles per well. After 4 days of culture, 68% healthy cumulus-enclosed oocytes from these follicles were obtained, and 51% of the oocytes completed meiotic maturation to the metaphase II stage. Fifty-three percent of the mature oocytes underwent fertilization, 43% of the fertilized oocytes cleaved, and 13% developed to the blastocyst stage. The results show 1) that porcine preantral follicles can grow efficiently to the antral stage using these culture conditions, and 2) that oocytes from in vitro-matured porcine preantral follicles can acquire meiotic competence and undergo fertilization and embryonic development.

The correlation of sperm chromatin decondensation following in vitro exposure to heparin and sperm penetration rates.

PURPOSE: The aim of this study was to evaluate the possible correlation of low-dose heparin-induced decondensation of sperm chromatin with sperm concentration, motility, morphology, membrane hypoosmotic response, ejaculate volume, and the ability of sperm to penetrate zona-free hamster oocytes. METHODS: Twenty-two donors of known fertility and 105 patients undergoing evaluation at an andrology laboratory were evaluated by standard World Health Organization semen analysis techniques and a modified sperm penetration assay (SPA). An aliquot was also incubated for 60 min and Ham's F10 medium containing 50 USP/ml heparin. The percentage of sperm undergoing chromatin decondensation was evaluated and correlated to SPA rates and semen quality parameters. RESULTS: No significant correlation was observed between semen parameters and decondensation rates. A nonsignificant (P = 0.11) inverse correlation (P = -0.21) was observed between SPA rates and chromatin decondensation. Significant (P < 0.001) differences were observed in the decondensation rate of donors (3.7 +/- 0.6), patients with normal SPA rates (7.8 +/- 1.5), and patients with decreased SPA rates (21.7 +/- 1.8). The decondensation rates were significantly different (P < 0.01) between patients with a normal SPA rate and patients with a decreased SPA rate. CONCLUSIONS: These data indicate a significant inverse relationship between the SPA rate, which has previously been shown to correlate highly with fertilization ability and heparin-induced sperm chromatin decondensation.

Sperm chromosome aneuploidy as related to male factor infertility and some ultrastructure defects.

Some men have elevated levels of sperm chromosome aneuploidy. In this study, we have evaluated and summarized sperm aneuploidy rates in male infertility patients and control groups. The mean aneuploidy rate for five chromosomes (X, Y, 13, 18, 21) was 1.2 +/- 0.1 for fertile controls, 1.4 +/- 0.1 for a general population control group, and 5.8 +/- 1.14 for the patients. When the patients were classified by the type of male factor infertility, the total aneuploidy rate was 2.6 +/- 0.3 in men with moderately diminished semen quality (n = 7), 4.0 +/- 0.3 patients with severe teratoasthenooligozoospermia, and 15.9 +/- 3.8 for men with rare ultrastructure defects such as round head only syndrome or severe tail agenesis. Some infertility patients have a severely elevated level of sperm chromosome aneuploidy, which may contribute to infertility or diminish the likelihood of a successful outcome from IVF/ICSI. The severity of sperm chromosome aneuploidy appears to be proportional to the severity of abnormal semen quality: in particular, abnormal morphology. The high rates of aneuploidy in patients with severe ultrastructure defects suggest that caution should be employed in counseling those patients prior to IVF/ICSI.