Showing papers in "Journal of Andrology in 2010"

P Granule Assembly and Function in Caenorhabditis elegans Germ Cells

Abstract: Germ granules are large, non-membrane-bound, ribonucleoprotein (RNP) organelles found in the germ line cytoplasm of most, if not all, animals. The term germ granule is synonymous with the perinuclear nuage in mouse and human germ cells. These large RNPs are complexed with germ line-specific cytoplasmic structures such as the mitochondrial cloud, intermitochondrial cement, and chromatoid bodies. The widespread presence of germ granules across species and the associated germ line defects when germ granules are compromised suggest that germ granules are key determinants of the identity and special properties of germ cells. The nematode Caenorhabditis elegans has been a very fruitful model system for the study of germ granules, wherein they are referred to as P granules. P granules contain a heterogeneous mixture of RNAs and proteins. To date, most of the known germ granule proteins across species, and all of the known P granule components in C elegans, are associated with RNA metabolism, which suggests that a main function of germ granules is posttranscriptional regulation. Here we review P granule structure and localization, P granule composition, the genetic pathway of P granule assembly, and the consequences in the germ line when P granule components are lost. The findings in C elegans have important implications for the germ granule function during postnatal germ cell differentiation in mammals.

microRNAs in the testis: building up male fertility

Abstract: Spermatogenesis is a strictly regulated process, at both the transcriptional and the posttranscriptional level, which allows continuous gamete production throughout adulthood. A novel mechanism of posttranscriptional control mediated by microRNAs (miRNAs) has lately emerged as an important regulator of spermatogenesis. miRNAs are endogenous, small, noncoding RNAs produced through a multistep enzymatic process, which involves the action of Dicer, an RNaseIII endonuclease. Here, we first present a short overview of classic posttranscriptional control during spermatogenesis, and then concentrate on recent findings that have unraveled the important role of miRNAs in male reproductive function. Particular focus is given to the in vivo role of miRNAs that has been demonstrated through the generation of Sertoli cell-specific or germ cell-specific Dicer knockouts, as well as the potential application of these findings in the treatment of human male infertility and the development of male contraceptives. It is anticipated that unraveling miRNA functions in the testis will further our understanding of the regulatory mechanisms of mammalian spermatogenesis.

LDHC: the ultimate testis-specific gene.

Abstract: Lactate dehydrogenase C (LDHC) was, to the best of our knowledge, the first testis-specific isozyme discovered in male germ cells. In fact, this was accomplished shortly before "isozymes or isoenzymes" became a field of study. LDHC was detected initially in human spermatozoa and spermatogenic cells of the testes by gel electrophoresis. Immunohistochemistry was used to localize LDHC first in early-pachytene primary spermatocytes, with an apparent increase in quantity after meiosis, to its final localization in and on the principal piece of the sperm tail. After several decades of biologic, biochemical, and genetic investigations, we now know that the lactate dehydrogenase isozymes are ubiquitous in vertebrates, developmentally regulated, tissue and cell specific, and multifunctional. Here, we will review the history of LDHC and the work that demonstrates clearly that it is required for sperm to accomplish their ultimate goal, fertilization.

Effect of Experimental Diabetes and STZ on Male Fertility Capacity. Study in Rats

Abstract: To assess the effect of experimental Type 1 diabetes on male fertility, male Sprague Dawley rats were injected with either streptozotocine (STZ) to induce diabetes or with citrate buffer as controls. Diabetic animals and 2 control groups (STZ-resistant and buffer-injected rats) were sacrificed at 2 different times after injection: 6 weeks (6W) and 20 weeks (20W). We analyzed serum testosterone (sTT), epididymal sperm parameters, and weight of testicles and epididymides, and carried out a histological evaluation of testicular tissue. Diabetic animals presented a significant increase in teratozoospermia (20W, P < .01) and a decrease in sTT (P < .01), tubular diameter (6W, P < .05), and testicular (6W, P < .01) and epididymal (P < .01) weight. STZ-resistant animals showed significantly decreased sTT (6W, P < .01), epididymal weight (6W, P < .05), and sperm count (6W, P < .01) compared with buffer-injected controls. Experimental STZ diabetes increases teratozoospermia and decreases sTT, testicular weight (reverting at medium-term), and epididymal weight.

Spermatozoa Bound to Solid State Hyaluronic Acid Show Chromatin Structure With High DNA Chain Integrity: An Acridine Orange Fluorescence Study

Abstract: During human spermiogenesis, the elongated spermatids undergo a plasma membrane remodeling step that facilitates formation of the zona pellucida and hyaluronic acid (HA) binding sites. Various biochemical sperm markers indicated that human sperm bound to HA exhibit attributes similar to that of zona pellucida-bound sperm, including minimal DNA fragmentation, normal shape, and low frequency of chromosomal aneuploidies. In this work, we tested the hypothesis that HA-bound sperm would be enhanced in sperm of high DNA chain integrity and green acridine orange fluorescence (AOF) compared with the original sperm in semen. Sperm DNA integrity in semen and in their respective HA-bound sperm fractions was studied in 50 men tested for fertility. In the semen samples, the proportions of sperm with green AOF (high DNA integrity) and red AOF (DNA breaks) were 54.9% ± 2.0% and 45.0% ± 1.9%, whereas in the HA-bound sperm fraction, the respective proportions were 99% and 1.0%, respectively. The data indeed demonstrated that HA shows a high degree of selectivity for sperm with high DNA integrity. These findings are important from the points of view of human sperm DNA integrity, sperm function, and the potential efficacy of HA-mediated sperm selection for intracytoplasmic sperm injection.

Protective effects of ascorbate and catalase on human spermatozoa during cryopreservation.

Abstract: Human semen cryopreservation in the clinical management of male infertility is complicated by cryodamage to spermatozoa. We aimed to clarify the full pattern of cryodamage and evaluate the protective effects of ascorbate and catalase on cryopreserved spermatozoa. Semen samples were collected from 30 fertile males. Each sample was divided into 6 groups: fresh semen, cryopreserved semen without treatment, and samples cryopreserved with ascorbate (300 or 600 μM) or catalase (200 or 400 IU/mL). Spermatozoa were examined for their viability, motility, reactive oxygen species (ROS) generation, mitochondrial membrane potential (MMP), apoptosis (positive for annexin V and negative for propidium iodide [ie, Ann(+)/PI(-)]), and DNA damage (Olive tail moment [OTM]) in the presence or absence of ascorbate or catalase during cryopreservation. In comparison with the fresh spermatozoa, there was a significant decrease in the viability, motility, and MMP but increase in Ann(+)/PI(-) and OTM in the cryopreserved spermatozoa (P < .01 and P < .05, respectively). Concurrently, ROS levels in the postthaw spermatozoa also increased significantly, and this elevation was well correlated with the quality variations of postthaw spermatozoa (P < .01 for all). Ascorbate (300 μM) and catalase (200 and 400 IU/mL) reduced the ROS levels in postthaw spermatozoa significantly, compared with those in the control (P < .05). Furthermore, these antioxidants also prevented those characteristics from being adversely affected (P < .05). This study demonstrated that cryopreservation results in cryodamage to human spermatozoa, possibly through the mechanism of ROS. Appropriate ascorbate or catalase supplementation of cryoprotective medium restrains ROS levels and the resultant cryodamage.

Relationship between urine bisphenol-A level and declining male sexual function.

Abstract: The adverse effect of bisphenol-A (BPA) on the male reproductive system observed in animal studies has not been well examined in human populations. BPA is potentially a serious public health problem because of its widely detected presence in the human body. This study was conducted among 427 male workers in regions where high levels of BPA exposure existed. All participants provided urine samples, which were tested for BPA concentration using high-performance liquid chromatography. Male sexual dysfunction was ascertained using standard male sexual function inventories. Male sexual dysfunction was measured in 4 domains using 7 indices. After controlling for potential confounders using linear regression, increasing urine BPA level was associated with worsening male sexual function on a continuous scale. All 7 indices demonstrated this negative linear correlation. Increasing urine BPA level was associated with decreased sexual desire (P < .001), more difficulty having an erection (P < .001), lower ejaculation strength (P < .001), and lower level of overall satisfaction with sex life (P < .01). A similar negative correlation was also observed among participants exposed to BPA from only environmental sources (no occupational exposure to BPA), although the estimates in this group were less stable because of a smaller sample size. Our results reveal a correlation between a biological measure of urine BPA level and declining male sexual function. This finding may enhance the understanding of the BPA effect in human populations, and may have important public health implications given the widespread human exposure to BPA.

Seminal plasma proteins as potential markers of relative fertility in boars.

Abstract: This study investigated whether specific proteins from distinct seminal plasma fractions of boars could be related to in vivo fertility. Nine boars with acceptable sperm motility and morphology for use in artificial insemination demonstrated major differences in total number born and pregnancy rate when low sperm doses (1.5 billion sperm) were used to breed a minimum of 50 gilts per boar. The 2 lowest-fertility and 2 highest-fertility boars were chosen for evaluation of specific seminal plasma proteins. On 4 occasions, semen was collected and separated into 3 fractions based on sperm concentration (Sperm-Peak, Sperm-Rich, and Sperm-Free), and the fractions were analyzed for total protein concentration and abundance of major seminal plasma glycoprotein (PSP-I), AWN-1, and osteopontin protein using Western blotting techniques. The concentrations of these seminal plasma proteins were lower in the Sperm-Peak fractions compared with the Sperm-Free fractions (P < .05). Seminal plasma from the pooled Sperm-Rich fraction used for artificial insemination was also subjected to two-dimensional gel electrophoresis to investigate novel protein markers related to in vivo fertility. Total piglets born (r = -0.76, P = .01) and sperm motility at day 7 (r = -0.74, P = .037) were again negatively correlated with a 22-kDa protein identified by mass spectrometry as PSP-I. However, fertility index and farrowing rate tended to be positively correlated (P < .10) with a 25-kDa protein, identified as glutathione peroxidase (GPX5), an antioxidant enzyme that may protect sperm membranes from oxidative damage. These candidate proteins merit further investigation as markers of fertility in boars.

Fetal Leydig cells: progenitor cell maintenance and differentiation.

Abstract: In most eutherian mammals, sexually dimorphic masculinization is established by androgen-producing fetal Leydig cells in the embryonic testis. Fetal Leydig cells, which lack expression of the testis-determining gene SRY, arise after the appearance of SRY-expressing Sertoli cells. Therefore, the appearance and differentiation of fetal Leydig cells are probably regulated by factors derived from Sertoli cells. Results from mouse genetic models have revealed that maintenance and differentiation of fetal Leydig cell population depends upon a balance between differentiation-promoting and differentiation-suppressing mechanisms. Although paracrine signaling via Sertoli cell-derived Hedgehog ligands is necessary and sufficient for fetal Leydig cell formation, cell-cell interaction via Notch signaling and intracellular transcription factors such as POD1 are implicated as suppressors of fetal Leydig cell differentiation. This review provides a model that summarizes the recent findings in fetal Leydig cell development.

Amelioration of Penile Fibrosis: Myth or Reality

Abstract: Several changes have been reported to occur in the cavernosal tissue and tunica albuginea with aging. The atherosclerosis of the penis that occurs with aging causes a decrease in penile oxygen tension. A reduction in the number of smooth muscle cells (SMCs) has been demonstrated in relation to this change in oxygen tension. Changes in the ratio of penile collagen have also been observed and could explain the decrease in penile elasticity and compliance with aging. Chronic ischemia is therefore associated with fibrosis but also with nitric oxide-cGMP reduction. The sensitivity of the α-adrenoceptors on the SMCs increases with aging. Furthermore, androgen deprivation produces penile tissue atrophy, alterations in dorsal nerve structure, alterations in endothelial morphology, reductions in trabecular SM content, increases in deposition of extracellular matrix, and increases in accumulation of adipocytes in the subtunical region of the corpus cavernosum. All of these modifications can explain the prevalence of erectile dysfunction with aging. The aim of this review is to address the underlying etiology of corporal fibrosis, especially aging, cavernosal nerve damage, androgen deprivation, and tunical fibrosis. Finally, we will address the proposed amelioration and reversal of fibrosis in terms of correcting, at least partially, the relative SMC loss that occurs with aging, diabetes, or cavernosal nerve damage and its impact on prevention of erectile dysfunction-associated cavernosal fibrosis.

Histone demethylase JHDM2A is involved in male infertility and obesity.

Abstract: Recent studies indicate that histone lysine methylation is subject to enzyme-catalyzed reversion, and jumonji C (JmjC) domain-containing proteins have been identified as one of the members of histone demethylases. Although an increasing number of histone demethylases have been identified and biochemically characterized, their biological functions are poorly characterized. To elucidate the physiological functions, we generated the knockout mouse model of dimethylated or monomethylated histone 3 lysine 9 (H3K9me2/1)-specific JmjC domain-containing histone demethylase 2A (JHDM2A; also known as JMJD1A and KDM3A) and showed that JHDM2A is essential for spermatogenesis. Jhdm2a-deficient mice exhibited impaired postmeiotic chromatin condensation, which caused infertility, even though the hormonal levels were maintained. Further molecular and biochemical analysis revealed that JHDM2A directly bound to the core promoter regions of transition nuclear protein 1 (Tnp1) and protamine 1 (Prm1) genes, and it induced the transcriptional activation of these genes by removing H3K9 methylation, which is known as a silencing marker of gene transcription. This work uncovered a role for JHDM2A in spermatogenesis and identified 2 downstream genes that are critical for sperm nuclear condensation. In addition, we also showed that JHDM2A plays a role in regulating fat metabolic gene expression in muscle and brown fat tissue, and the knockout mice exhibited obesity and hyperlipidemia. Thus, JHDM2A possesses organ/tissue-specific target genes, and impairment of this molecule cannot be compensated by other JmjC-containing histone demethylases, suggesting the importance of this molecule in vivo.

Roles of androgen receptor in male and female reproduction: lessons from global and cell-specific androgen receptor knockout (ARKO) mice.

Abstract: The androgen receptor (AR), a member of the nuclear receptor superfamily, is a ligand-dependent transcription factor involved in regulating expression of an array of androgen-responsive genes. AR-mediated androgen actions play the important roles in male and female reproductive development and function. AR mutations can cause a diverse range of diseases, such as testicular feminization mutation (Tfm) syndrome, prostate cancer, and Kennedy's disease. However, because of a lack of genetic models, the molecular mechanisms involved in the physiological and pathological effects of androgen-AR function in male and female reproductive health remains largely unknown. To get a better insight into the molecular working mechanisms of the AR, a global and several cell-specific conditional knockout mouse models have been developed. These models are reviewed here, and the phenotypes of the different cell-specific androgen receptor knockout (ARKO) mice are compared with those of the global ARKO mice.

Pharmacokinetics and safety of long-acting testosterone undecanoate injections in hypogonadal men: an 84-week phase III clinical trial.

Abstract: Currently available testosterone (T) injections in the United States are administered at 2-3 weekly intervals. Less frequent injections with favorable serum T pharmacokinetics would benefit hypogonadal men. The objective of this study is to assess the pharmacokinetics of long-acting testosterone undecanoate (TU) intramuscular (IM) injection in hypogonadal men. An unblinded, multicenter phase 3 clinical trial was conducted in 31 academic centers and contract research organizations. Males (130) more than 18 years of age with serum total T < 300 ng/dL were enrolled and received 750-mg injections of TU at weeks 0 and 4 and every 10 weeks thereafter for 9 injections over 84 weeks. The main outcome variables were serum total T, free T, dihydrotestosterone (DHT), estradiol (E(2)) levels, and safety parameters. After the first injection, patients maintained average trough T concentrations in the adult male range (300-1000 ng/dL or 10.4-34.7 nmol/L) before each injection and at multiple time points measured after the third and fourth injections. Serum free T, DHT, and E(2) levels and their ratios to serum T remained relatively consistent once steady state was attained. TU injections were generally well tolerated, with safety profiles similar to other T replacement. We conclude that hypogonadal patients treated for 84 weeks with a 750-mg IM injection of TU every 10 weeks demonstrated average concentrations of T, its metabolites (DHT and E(2)), and ratios--DHT:T and E(2):T--within the adult male reference range at all time points measured. TU injections would be an acceptable alternative to the currently available 2-3 weekly injectables.

Oxidative stress in rat testis and epididymis under intermittent hypobaric hypoxia: protective role of ascorbate supplementation.

Abstract: Hypobaric hypoxia (HH), an environmental condition of high altitude encountered by mountaineers, miners, and observatory, rural health, border patrol, and rural education workers, jeopardizes normal physiologic functions in humans. The present study was conducted to evaluate the effects of intermittent HH (IHH; equivalent to 4600 m above mean sea level) on oxidative stress and the protective role of dietary ascorbic acid on rat testis and epididymis. Ten-week-old male Wistar rats were assigned to 1 of 6 groups: 1) normobaric (Nx), 2) Nx + physiologic solution (Nx + PS), 3) Nx + ascorbic acid (Nx + AA), 4) IHH, 5) IHH + PS, or 6) IHH + AA. Animals subjected to IHH were exposed for 96 hours followed by normobaric conditions for 96 hours for a total of 32 days. The control groups (2 and 5) were injected with doses of PS, and the treated groups (3 and 6) were injected with doses of AA (10 mg x kg(-1) body weight) at an interval of 96 hours. Rats were sacrificed on day 32 after initiation of the protocol. The testis and epididymis were collected to determine the activity and expression of glutathione reductase and the levels of lipid peroxide formation. An epididymal sperm count was also performed in each animal. The results of this study revealed that IHH induced lipid peroxidation, a reduction in glutathione reductase activity in testis and epididymis, and a significant decrease in epididymal sperm count. Treatment with AA prevented these changes. In conclusion, AA was capable of decreasing oxidative stress in testis and epididymis under IHH. This protection by AA of the IHH-induced lipid peroxidation can be explained in part by the preservation of glutathione reductase activity in these organs.

Deletion of the Igf1 gene: suppressive effects on adult Leydig cell development.

Abstract: Deletion of the insulin-like growth factor 1 (Igf1) gene was shown in previous studies to result in reduced numbers of Leydig cells in the testes of 35-day-old mice, and in reduced circulating testosterone levels. In the current study, we asked whether deletion of the Igf1 gene affects the number, proliferation, and/or steroidogenic function of some or all of the precursor cell types in the developmental sequence that leads to the establishment of adult Leydig cells (ALCs). Decreased numbers of cells in the Leydig cell lineage (ie, 3β-hydroxysteroid dehydrogenase-positive cells) were seen in testes of postnatal day (PND) 14-90 Igf1(-/-) mice compared with age-matched Igf1(+/+) controls. The development of ALCs proceeds from stem Leydig cells (SLCs) through progenitor Leydig cells (PLCs) and immature Leydig cells (ILCs). The bromodeoxyuridine labeling index of putative SLCs was similar in the Igf1(-/-) and Igf1(+/+) mice. In contrast, the labeling index of PLCs was reduced in the Igf1(-/-) mice on each day of PND 14 through PND 35, and that of more mature Leydig cells (referred to herein as LCs, a combination of ILCs plus ALCs) was reduced from PND 21 through PND 56. In Igf1(-/-) mice that received recombinant IGF-I, the labeling indices of PLCs and LCs were similar to those of age-matched Igf1(+/+) mice, indicating that the reductions in the labeling indices seen in the PLCs and LCs of the Igf1(-/-) mice were a consequence of reduced IGF-I. On each day of PND 21 through PND 90, testicular testosterone concentrations were significantly reduced in the Igf1(-/-) mice, as were the expressions of testis-specific mRNAs involved in steroidogenesis, including Star, Cyp11a1, and Cyp17a1. The increased expression of the gene for 5α-reductase (Srd5a1) in adult Igf1(-/-) testes suggests that the depletion of Igf1 might suppress or delay Leydig cell maturation. These observations, taken together, indicate that the reduced numbers of Leydig cells in the adult testes of Igf1(-/-) mice result at least in part from altered proliferation and differentiation of ALC precursor cells, but not of the stem cells that give rise to these cells.

Semen quality of male idiopathic infertile smokers and nonsmokers: an ultrastructural study

Abstract: This retrospective study was aimed at evaluating the effects of cigarette consumption on semen parameters in a group of men with idiopathic infertility. The semen quality of 2 groups of men with idiopathic infertility, smokers (n = 118) and nonsmokers (n = 153), were compared. Conventional semen analysis was performed and sperm morphology was assessed by transmission electron microscopy (TEM). TEM data were elaborated by means of a mathematical formula based on a Bayesian technique able to furnish a fertility index (FI), and the percentages of sperm apoptosis, necrosis, and immaturity. Values of normality recommended by World Health Organization guidelines were used as a control for conventional semen analysis, and values from sperm of 25 men of proven fertility were used for TEM indices. Infertile smoker and nonsmoker patients showed similar sperm parameters, although sperm motility and TEM analysis values in both groups were significantly impaired compared with controls. Smoker patients were then classified as mild (>or=1 and 10 and or=20 cigarettes/d). Sperm concentration and FI were significantly (P < .05) different among the 3 considered smoker classes. Comparing the pairs of smoker classes, sperm concentration and FI in heavy smokers were significantly lower (P < .05) than that observed in mild smoker and nonsmoker groups. Although semen quality in males with idiopathic infertility seems not to be dramatically affected by cigarette consumption, heavy smokers show significantly lower sperm concentration and FI: another strong reason to stop smoking.

Small variations in crucial steps of TUNEL assay coupled to flow cytometry greatly affect measures of sperm DNA fragmentation.

Abstract: Techniques for assessing sperm DNA damage are numerous and various There are 2 main types of assay: direct and indirect The former directly detects the amount of sperm DNA damage, whereas the latter reveals the effects of an exogenous insult on sperm chromatin In addition, even considering the same type of technique, different strategies to reveal or quantify sperm DNA damage, or both, are used Finally, these techniques, except for sperm chromatin structure assay (SCSA), lack standardized protocols to which all users can adhere to minimize interlaboratory variations In this study, we investigated the effects of some of the many ways the terminal deoxynucleotidyl transferase-mediated fluorescein-dUTP nick end labeling (TUNEL) assay is performed when measuring sperm DNA fragmentation by flow cytometry In addition, by using an established procedure, we determined the precision of the technique by calculating intra-assay coefficients of variation (CVs) We found that concentration of the fixative, the time of storage of fixed samples, the fluorochrome used to label DNA breaks, and the method used to analyze flow cytometric data all greatly affect the measures of sperm DNA fragmentation In particular, we found that treatment with paraformaldehyde produced additional damage in most samples, suggesting that TUNEL also can be considered an indirect assay when performed in semen samples treated with such a fixative reagent We also showed that 2 different methods used to analyze data yielded results that, albeit correlating, were different and associated differently to semen quality On the contrary, the TUNEL assay, as measured here, showed low intraassay CVs, resulting in a quite precise technique when performed in established conditions

Assessment of seminal estradiol and testosterone levels as predictors of human spermatogenesis.

Abstract: The proposed hypothesis for this study was that seminal testosterone/estradiol levels and/or their ratios may be a good indicator for predicting normal spermatogenesis. The concentrations of estradiol and testosterone in seminal fluid were measured using competitive immunoassay techniques in specimens collected from 192 infertile patients and 103 normospermic men. Infertile patients were subdivided into three groups according to their semen analysis results and testicular biopsy: oligozoospermia, obstructive azoospermia (OA), and nonobstructive azoospermia (NOA). Results showed that seminal testosterone levels in the infertile groups were lower than in the normospermic individuals (P < .01), whereas seminal estradiol levels in the OA group were significantly higher than those in normospermic and NOA groups (P < .01). Testosterone/estradiol ratios in the seminal plasma from the infertile groups were significantly lower than that in the normospermic group (P < .01). However, seminal estradiol levels among normospermic and NOA groups showed no significant differences. These results suggest that the local balance between androgen and estrogen, or their ratios, may play an important role in maintaining normal spermatogenesis. Also, decreased seminal testosterone/estradiol ratio may be a good indicator for identifying the absence of sperm production in NOA patients.

Self-Reported Premature Ejaculation Prevalence and Characteristics in Korean Young Males: Community-Based Data From an Internet Survey

Abstract: Premature ejaculation (PE) is suspected to be the most prevalent male sexual complaint, and the prevalence of PE is considerably high also in the younger generation. We investigated the PE prevalence based on the Diagnostic and Statistical Manual of Mental Disorders (4th ed text revision; DSM-IV-TR) definition and the risk factors of PE in Korean young men via Internet survey. Subjects (n = 3980) aged from 20 to 59, who performed sexual intercourse more than once a month during the past 6 months were asked to participate in this study. Participants were asked to complete a questionnaire that consisted of questions on general, medical, and sexual history related to ejaculation. A total of 600 subjects were included in this study. PE prevalence was found to be 18.3%. Prevalences were not significantly different across age groups, after excluding subjects with erectile dysfunction (ED). Educational level, marital status and duration, average income, sexual orientation, smoking, alcohol consumption, and circumcision status showed no difference in the PE and non-PE groups. Partners perceived satisfaction rates were 45.0% in the PE group and 63.9% in the non-PE group. Significant differences were found between the PE and non-PE groups in terms of ED, obesity, and depression prevalence. However, multiple logistic regression analysis revealed that the significant risk factors of PE were age and the frequency of conversations with partners about sexual intercourse. This Internet-based study is limited because participants probably represent a selected population of Internet users with non-representative educational and socioeconomic profiles. This study is the first to report the prevalence of both self-reported PE and PE on the basis of the DSM-IV-TR definition in the Korean population. This study demonstrates that PE in Korea is as prevalent as it is in European countries and the United States.

Hypoxia‐Induced Apoptosis in the Bilateral Testes of Rats With Left‐Sided Varicocele: A New Way to Think About the Varicocele

Abstract: Although the varicocele has been studied for many years, its pathophysiology remains unclear. In this study, we investigated the expression of the alpha subunit of hypoxia-inducible factor 1 (HIF-1 alpha) and determined the apoptosis index (AI) in the testes of rats with varicoceles to study the mechanism by which varicoceles induce infertility. A total of 45 Wistar rats were divided into 3 groups: control group, sham surgery group, and experimental group. Forty-nine days after the initial partial ligation of the left renal vein, all of the rats underwent orchiectomy. HIF-1 alpha expression in each testis was analyzed using immunohistochemical methods and enzyme-linked immunosorbent assay. The degree of apoptosis within each testicle was determined using terminal deoxynucleotidyl transferase dUTP nick end labeling. HIF-1 alpha immunoreactivity in the testes of the experimental group was significantly higher than that in those of the control group (P < .05) or the sham group (P < .05). The AI of the germ cells of rats in the experimental group was significantly higher than that in germ cells of rats in the sham group (P < .001) or the control group (P < .001). Additionally, there was a significant positive correlation observed between the AI of germ cells and relative intensity of HIF-1 alpha in the left testis (r = .631; P = .028) and right testis (r = .707; P = .01) of rats in the experimental group. The results of this study showed that a left-sided varicocele could cause bilateral testicular hypoxia and increased germ cell apoptosis, both of which play an important role in testicular dysfunction. Furthermore, HIF-1 alpha is a useful factor that can be used to predict the degree of germ cell apoptosis in rat testes.

Raised inflammatory markers in semen from men with asymptomatic chlamydial infection.

Abstract: The aim of this study was to determine whether interleukin (IL)-6 and IL-8 concentrations, as well as numbers of seminal leukocytes in a population of infertile men, some of whom were Chlamydia trachomatis positive, were related to chlamydial infection. Our patient group included 255 men attending for diagnostic semen analysis as part of infertility investigations. Significantly raised levels of IL-8, but not IL-6, were found in C trachomatis-infected patients but not in uninfected patients. Raised IL-8 levels in semen were also associated with an increase in semen volume. There was a relationship between C trachomatis infection and lower progressive motile sperm, as well as an increase in seminal leukocytes. The overall prevalence rate for C trachomatis was 6.2%, and more infections were detected in semen than in first void urine. This study supports the suggestion that IL-8 might be used as a marker for male genital tract infection, especially when due to C trachomatis. In this study, there was a relationship between the presence of C trachomatis in semen and alterations of some semen parameters. Further investigations should be performed to understand the disparities of first void urine and semen testing for detection of C trachomatis in males.

Changes in the Expression Profile of the Meiosis‐Involved Mismatch Repair Genes in Impaired Human Spermatogenesis

Abstract: DNA mismatch repair (MMR) genes have been described to participate in crossover events during meiotic recombination, which is, in turn, a key step of spermatogenesis. This evidence suggests that MMR family gene expression may be altered in infertile men with defective sperm production. In order to determine the expression profile of MMR genes in impaired human spermatogenesis, we performed transcript levels analysis of MMR genes (MLH1, MLH3, PMS2, MSH4, and MSH5), and other meiosis-involved genes (ATR, HSPA2, and SYCP3) as controls, by real-time reverse transcription-polymerase chain reaction in testis from 13 patients with spermatogenic failure, 5 patients with primary germ cell tumors, and 10 controls with conserved spermatogenesis. Correlation of the expression values with the histological findings was also performed. The MMR gene expression values, with the exception of PMS2, are significantly decreased in men with spermatogenic failure. The pattern of MMR reduction correlates with the severity of damage, being maximum in maturation arrest. Specifically, expression of the testicular MSH4 gene could be useful as a surrogate marker for the presence of intratesticular elongated spermatid in patients with nonobstructive azoospermia, contributing to predict the viability of assisted reproduction. Interestingly, a reduction in the MSH4 and MSH5 transcript concentration per spermatocyte was also observed. The decreased expression level of other meiosis-specific genes, such as HSPA2 and SYCP3, suggests that the spermatocyte capacity to express meiosis-related genes is markedly reduced in spermatogenic failure, contributing to meiosis impairment and spermatogenic blockade.

Estradiol and Metabolic Syndrome in Older Italian Men: The InCHIANTI Study

Abstract: The increasing prevalence of metabolic syndrome (MS) with age in older men has been linked with decreasing testosterone levels. Interestingly, while testosterone levels decline with age, estradiol (E2) levels remain relatively stable, resulting in a decreased testosterone:E2 ratio. Because E2 levels tend to be elevated in morbid obesity, insulin resistance, and diabetes, it is reasonable to hypothesize that high E2 levels are associated with MS in older men. We studied the relationship of total and free E2 with MS after adjustment for multiple confounders, including age, BMI, smoking, alcohol consumption, physical activity, interleukin-6 (IL-6), fasting insulin, and testosterone. Men 65 years or older (age range, 65-96; n = 452) had complete data on E2, testosterone, fasting insulin, sex hormone-binding globulin, IL-6, and albumin. Concentrations of free E2 and free testosterone were calculated using the mass action equations. MS was defined according to Adult Treatment Panel III (ATP-III). Participants with MS had significantly higher serum free and total E2 (P < .001) (P = .003). After adjusting for confounders, including age, smoking, alcohol consumption, physical activity, log(IL-6), and log(insulin), participants with higher log(total E2) (odds ratio [OR], 2.31; 95% confidence interval [95% CI], 1.39-4.70; P = .02) and higher log(free E2) (OR, 2.69; 1.38-5.24; P < .001) had an increased risk of having MS. Log(free E2) (P = .04) maintained significant correlation with MS, even after further adjustment for BMI. In older men, high E2 is independently associated with MS. Whether confirmed in other studies, assessment of E2 should be also considered in older men. Whether changes in this hormonal pattern play a role in the development of MS should be further tested in longitudinal studies.

Determination and stability of gonadal sex.

Abstract: The discovery that the SRY gene induces male sex in humans and other mammals led to speculation about a possible equivalent for female sex. But females are proving to be more complicated. Several master genes appear to be autonomously involved, and female sex determination seems to remain relatively labile. Partial loss of function of the transcription factor FOXL2 leads to premature ovarian failure in women; and in animal models, Foxl2 is required for folliculogenesis as well as for maintenance, and possibly induction, of female sex determination. In the germ line, oocytes apparently form normally even in the absence of Foxl2, dependent on genes that include female-specific factors such as Fig-alpha, Nobox, etc. In the soma, ablation of Foxl2 or the independently expressed gene Wnt4 (likely downstream of Rspo1) can produce partial testis differentiation in XX mice, and the double knockout results in the formation of tubules and spermatogonia. This indicates that at least 2 autonomous ovarian pathways are required to antagonize testis differentiation in females, a finding that is being increasingly corroborated by studies in goats and nonmammalian vertebrates. In recent expression profiling of mouse ovaries that lack Foxl2 alone or in combination with Wnt4 or Kit/c-Kit, we found that following Foxl2 loss, early testis genes (including the downstream effector of Sry, Sox9) and several novel ovarian genes were consistently dysregulated during embryo-fetal development. The results support the proposal of dose-dependent Foxl2 function and antitestis action. A partial working model for somatic development and sex determination is presented in which Sox9 is a direct antagonist of Foxl2 in the supporting cell lineage.

The Power of Mouse Genetics to Study Spermatogenesis

Abstract: Approximately 80 million people worldwide are infertile, and nearly half of all infertility cases are attributed to a male factor. Therefore, progress in reproductive genetics becomes crucial for future diagnosis and treatment of infertility. In recent years, enormous progress has been made in this field. More than 400 mutant mouse models with specific reproductive abnormalities have been produced, and numerous human association studies have been discovered. However, the translation of basic science findings to clinical practice remains protracted, with only modest progress in the application of novel findings to clinical genetic testing and cures. To date, the most significant findings in male infertility remain numeric and structural chromosomal abnormalities and Y-chromosome microdeletions in infertile men. Thus, we anticipate that future genetic investigations will focus on infertile men with a normal somatic karyotype but with various spermatozoal defects, like insufficient production of spermatozoa (oligozoospermia), inadequate motility (asthenozoospermia), abnormal morphology (teratozoospermia), or combinations of these defects. Ultimately, basic advances in mammalian nonhuman reproduction will translate to clinical advances in human reproduction and testing for infertile humans, thereby helping to improve diagnostics and health care for infertile patients.

Regulation of male fertility by X-linked genes.

Abstract: Infertility is a worldwide reproductive health problem, affecting men and women about equally. Mouse genetic studies demonstrate that more than 200 genes specifically or predominantly regulate fertility. However, few genetic causes of infertility in humans have been identified. Here, we focus on the regulation of male fertility by X-linked, germ cell-specific genes. Previous genomic studies reveal that the mammalian X chromosome is enriched for genes expressed in early spermatogenesis. Recent genetic studies in mice show that X-linked, germ cell-specific genes, such as A-kinase anchor protein 4 (Akap4), nuclear RNA export factor 2 (Nxf2), TBP-associated factor 7l (Taf7l), and testis-expressed gene 11 (Tex11), indeed play important roles in the regulation of male fertility. Moreover, we find that the Taf7l Tex11 double-mutant males exhibit much more severe defects in meiosis than either single mutant, suggesting that these 2 X-linked genes regulate male meiosis synergistically. The X-linked, germ cell-specific genes are particularly attractive in the study of male infertility in humans. Because males are hemizygous for X-linked genes, loss-of-function mutations in the single-copy X-linked genes, unlike in autosomal genes, would not be masked by a normal allele. The genetic studies of X-linked, germ cell-specific genes in mice have laid a foundation for mutational analysis of their human orthologues in infertile men.

Sleep, Sex Steroid Hormones, Sexual Activities, and Aging in Asian Men

Abstract: This was a cross-sectional study to examine the different associations of age and sleep duration with sex steroid hormones and sexual activities in 531 Asian Chinese men aged between 29 and 72 years old. Sleep duration and sexual activities were evaluated through a self-administered questionnaire, and total testosterone (T), sex hormone-binding globulin (SHBG), estradiol (E2), and dehydroepiandrosterone sulfate (DHEAS) were measured by established immunoassay methods in a single blood sample collected between 8:00 and 11:00 am. Bioavailable T (BioT) was calculated using the Vermeulen formula. Age was a major determinant of sleep, sex steroid hormones, and sexual activities in men. BioT, DHEAS, coital frequency, masturbation, and sleep duration declined with age. On the other hand, SHBG and E2 increased with age. Sleep duration, independently of age, aerobic exercise, and body fat, was positively associated with T and BioT, but not with DHEAS, E2, or any of the sexual activities studied. Men who masturbated had higher levels of both T and BioT. DHEAS was significantly associated with coital frequency and desire for sex. The present study showed that besides age, sleep duration was associated with androgen concentrations in men, and thus the evaluation of sleep hygiene may be beneficial in the management of men with low androgen concentrations. DHEAS may be independently associated with some sexual functions in men.

Serum LH Correlates Highly With Intratesticular Steroid Levels in Normal Men

Abstract: Sex steroids are essential for spermatogenesis; however, normal intratesticular concentrations of these hormones in man have not been extensively studied. To improve our understanding of intratesticular hormone concentrations, we performed bilateral testicular aspirations in a group of normal men, determined sex steroid concentrations within each testis, and compared these levels to serum hormone concentrations. Ten healthy human subjects aged 20-49 underwent bilateral testicular aspirations. Intratesticular hormone concentrations of testosterone, dihydrotestosterone (DHT), and estradiol were measured using liquid chromatography-tandem mass spectrometry. Intratesticular testosterone concentrations ranged from 119 to 1251 ng/mL, with a mean of 635 +/- 368 ng/mL. Intratesticular estradiol ranged from 0.41 to 3.9 ng/mL, with a mean of 2.4 +/- 1.3 ng/mL. Intratesticular DHT ranged from 1.1 to 7.9 ng/mL, with a mean of 3.5 +/- 3.2 ng/mL. Intratesticular testosterone and estradiol concentrations correlated highly with serum luteinizing hormone (LH; r = 0.87 and r = 0.70 respectively, P < .01). Intratesticular testosterone correlated highly with serum testosterone. Moreover, a significant correlation between the right and left testes was observed for testosterone (r = 0.82, P = .003), but not for estradiol or DHT. Intratesticular hormone concentrations can be safely assessed by testicular aspiration. Intratesticular testosterone and estradiol correlate highly with serum LH concentrations, and variation in serum LH accounts for most of the variation in intratesticular testosterone among men. In addition, intratesticular testosterone is highly correlated between testes in a given individual. Direct measurement of intratesticular testosterone will improve our understanding of the relationship between intratesticular sex steroids and spermatogenesis, and may have implications for the development of male hormonal contraception.

Rapid screening of cryopreservation protocols for murine prepubertal testicular tissue by histology and PCNA immunostaining.

Abstract: Numerous parameters have to be tested to identify optimal conditions for prepubertal testicular tissue banking. Our study evaluated 19 different cryopreservation conditions for immature testicular tissue using a rapid screening method. Immature mice testes were cryopreserved using either 1,2-propanediol (PROH) or dimethyl sulfoxide (DMSO) at a concentration of 0.75 or 1.5 M using a controlled slow-cooling rate protocol with (S+) or without seeding (S+). Equilibration was performed either at room temperature or at 4°C for 15 or 30 minutes. Seminiferous cord cryodamage was determined by scoring morphologic alterations. Cell proliferation ability was evaluated using a proliferating cell nuclear antigen (PCNA) antibody. Testes cryopreserved with optimal conditions were grafted into immunodeficient mice. The highest proportions of PCNA-positive nuclei and lowest morphologic alterations were observed with 1.5 M DMSO. Tissues were more altered with 0.75 M DMSO or PROH. Complete germ cell maturation was observed after allografting of testicular pieces previously frozen with 1.5 M DMSO, S+, 30 minutes. The 1.5 M DMSO, S+ or S+ protocol preserved prepubertal mice testicular tissue architecture and germ cell and Sertoli cell proliferation potential. Allografting of thawed testis fragments into immunodeficient mice confirmed that the 1.5 M DMSO, S+, 30 minutes protocol maintained testicular somatic and germ cell functions. Postthaw histologic evaluation and PCNA immunostaining are useful to rapidly test numerous freeze-thaw parameters. They may also be efficient tools to control human prepubertal frozen testis quality, within the context of a clinical application.

Molecular analysis of the SRD5A2 in 46,XY subjects with incomplete virilization: the P212R substitution of the steroid 5alpha-reductase 2 may constitute an ancestral founder mutation in Mexican patients.

Abstract: Inactivating mutations of the SRD5A2 gene result in steroid 5α-reductase 2 deficiency, an autosomal recessive disorder expressed as a male-limited disorder of sex development. Herein, genomic DNA was isolated from 11 new patients with apparent steroid 5α-reductase 2 deficiency. Coding sequence abnormalities in SRD5A2 were assessed by exon-specific polymerase chain reaction, single-stranded conformation polymorphism, and direct sequencing. Likewise, enzymatic activity of the P212R gene variant of SRD5A2 was assessed. DNA analysis revealed mutations in all patients (G115D, R171S, N193S, E197D, G203S, P212R). Three individuals were compound heterozygotes, 6 were homozygotes, and 2 more were single heterozygotes for SRD5A2 mutations; remarkably, 40% of the mutant alleles (9/22) contained the gene variant P212R. The results described in this study represent, along with our previous reports, the largest number of patients with steroid 5α-reductase 2 deficiency belonging to nonrelated families. Regarding the frequency of the p.P212R mutation in our population and its presence throughout all of our country, it allows us to hypothesize that the presence of this mutation may constitute a founder gene effect.