Showing papers in "Asian Journal of Andrology in 2007"

Epididymosomes are involved in the acquisition of new sperm proteins during epididymal transit.

Abstract: During epididymal transit, spermatozoa acquire new proteins. Some of these newly acquired proteins behave as integral membrane proteins, including glycosylphosphatidylinositol (GPI)-anchored proteins. This suggests that the secreted epididymal proteins are transferred to spermatozoa by an unusual mechanism. Within the epididymal lumen, spermatozoa interact with small membranous vesicles named epididymosomes. Many proteins are associated with epididymosomes and the protein composition of these vesicles varies along the excurrent duct and differs from soluble intraluminal proteins. Some epididymosome-associated proteins have been identified and their functions in sperm maturation hypothesized. These include P25b, a zona pellucida binding protein, macrophage migration inhibitory factor, enzymes of the polyol pathway, HE5/CD52, type 5 glutathione peroxidase, and SPAM1 or PH-20. The electrophoretic patterns of proteins associated to epididymosomes are complex and some of these proteins are transferred to defined surface domains of epididymal spermatozoa. Epididymosomes collected from different epididymal segments interact differently with spermatozoa. This protein transfer from epididymosomes to spermatozoa is time-dependent, temperature-dependent and pH-dependent, and is more efficient in the presence of zinc. Some proteins are segregated to lipid raft domains of epididymosomes and are selectively transferred to raft domains of the sperm plasma membrane. Some evidence is presented showing that epididymosomes are secreted in an apocrine manner by the epididymal epithelial cells. In conclusion, epididymosomes are small membranous vesicles secreted in an apocrine manner in the intraluminal compartment of the epididymis and play a major role in the acquisition of new proteins by the maturing spermatozoa.

Proteomic changes in mammalian spermatozoa during epididymal maturation.

Abstract: Epididymal maturation is associated with the activation of a cAMP-induced tyrosine phosphorylation cascade, which is ultimately associated with the expression of capacitation-dependent sperm functions, such as hyperactivated movement and acrosomal exocytosis. As spermatozoa progress through the epididymis they first acquire the capacity to phosphorylate tyrosine on targets on the principal piece, followed by the midpiece. By the time these cells have reached the cauda epididymidis they can phosphorylate the entire tail from neck to endpiece. This particular pattern of phosphorylation is associated with the ontogeny of fully functional spermatozoa that are capable of fertilizing the oocyte. Proteomic analyses indicate that this change is associated with the phosphorylation of several mitochondrial proteins, creation of a mitochondrial membrane potential and activation of mitochondrial free radical generation. At least in rodent species, activation of sperm mitochondria appears to be a particularly important part of epididymal maturation.

Phenotypic heterogeneity of mutations in androgen receptor gene

Abstract: Androgen receptor (AR) gene has been extensively studied in diverse clinical conditions. In addition to the point mutations, trinucleotide repeat (CAG and GGN) length polymorphisms have been an additional subject of interest and controversy among geneticists. The polymorphic variations in triplet repeats have been associated with a number of disorders, but at the same time contradictory findings have also been reported. Further, studies on the same disorder in different populations have generated different results. Therefore, combined analysis or review of the published studies has been of much value to extract information on the significance of variations in the gene in various clinical conditions. AR genetics has been reviewed extensively but until now review articles have focused on individual clinical categories such as androgen insensitivity, male infertility, prostate cancer, and so on. We have made the first effort to review most the aspects of AR genetics. The impact of androgens in various disorders and polymorphic variations in the AR gene is the main focus of this review. Additionally, the correlations observed in various studies have been discussed in the light of in vitro evidences available for the effect of AR gene variations on the action of androgens.

Study of the efficacy of Korean Red Ginseng in the treatment of erectile dysfunction

Abstract: Aim: To examine the treatment efficacy of Korean Red Ginseng (KRG) in impotent men with erectile dysfunction (ED). Methods: A total of 60 patients presenting mild or mild to moderate ED were enrolled in a double-blind, placebo-controlled study in which the efficacies of KRG and a placebo were compared. The patients received either 1 000 mg (3 times daily) of KRG or a placebo. Results: The five-item version of the International Index of Erectile Function (IIEF-5) score after the treatment was significantly higher in the KRG group compared with that before the treatment (from 16.4 ± 2.9 to 21.0 ± 6.3, P 0.05). In the KRG group, 20 patients (66.6%), reported improved erection, significant in the global efficacy question (P 0.05). Conclusion: Our data show that KRG can be an effective alternative to the invasive approaches for treating male ED.

Do reproductive hormones explain the association between body mass index and semen quality

Abstract: Aim: To examine whether reproductive hormones play a role in the association between body mass index (BMI) and semen quality. Methods: Semen quality and testosterone (T), luteinizing hormone (LH), follicle-stimulating hormone (FSH) and estradiol (E2) were evaluated in 990 fertile males with age 38.9 ± 9.7 (mean ± SD) years recruited from the Chinese general population in 2001 and 2002. Results: Semen quality was reduced among underweight (BMI < 18.5) compared with normal (BMI 18.5–24.9) and overweight (BMI 25.0–29.9), but the associations were independent of reproductive hormones. After adjustment for the potential confounders, underweight men had reductions in sperm concentration (22.4 × 10 6 /mL), total sperm count (52.9 × 10 6 ) and percentage of normal sperm forms (6.9%) compared with men with normal BMI. Being underweight may be a risk factor for low sperm concentration (OR: 4.68, 95% confidence intervals [CI]: 2.01–10.91). Otherwise, being overweight may be a protected factor for low sperm concentration (OR: 0.25; 95% CI: 0.08–0.83) and low total sperm count (OR: 0.37, 95% CI: 0.15–0.87). Conclusion: Low BMI was associated with reduced semen quality. The associations between BMI and semen quality were found statistically significant even after adjustment for reproductive hormones. Reproductive hormones cannot explain the association between BMI and semen quality. (Asian J Androl 2007 Nov; 9: 827–834)

Hypospadias: an update.

Abstract: Hypospadias is the most common congenital anomaly of the penis. The problem usually develops sporadically and without an obvious underlying cause. The ectopically positioned urethral meatus lies proximal to the normal site and on the ventral aspect of the penis, and in severe cases opens onto the scrotum or perineum. The foreskin on the ventral surface is deficient, while that on the dorsal surface is abundant, giving the appearance of a dorsal hood. Chordee is more common in severe cases. Cryptorchidism and inguinal hernia are the most common associated anomalies. The frequency of associated anomalies increases with the severity of hypospadias. For isolated anterior or middle hypospadias, laboratory studies are not usually necessary. Screening for urinary tract anomalies should be considered in patients with posterior hypospadias and in those with an anomaly of at least one additional organ system. The ideal age for surgical repair in a healthy child is between 6 and 12 months of age. Most cases can be repaired in a single operation and on an outpatient basis. Even patients with a less than perfect surgical result are usually able to enjoy a satisfactory sexual life.

Sperm maturation in the epididymis: a new look at an old problem

Abstract: The osmotic challenges facing maturing spermatozoa and their responses to them are discussed in relation to the concept of sperm maturation, defined as the increased ability of more distally recovered epididymal spermatozoa to fertilize eggs when inseminated into the female tract. One explanation could be that the more distal cells are better able to regulate their volume, and reach the oviducts, as a consequence of uptake of epididymal osmolytes. Increased motility, zona binding and oolemma fusion capacities are also acquired within the epididymis and are necessary for those cells that finally arrive at the site of fertilization.

Single nucleotide polymorphism C677T in the methylenetetrahydrofolate reductase gene might be a genetic risk factor for infertility for Chinese men with azoospermia or severe oligozoospermia.

Abstract: Aim: To analyze the distribution of the single nucleotide polymorphism (SNP) C677T in the methylenetetrahydrofolate reductase (MTHFR) gene in 355 infertile Chinese patients with idiopathic azoospermia or severe oligozoospermia and 252 fertile Chinese men as controls to explore the possible association of the SNP and male infertility Methods: Using the polymerase chain reaction (PCR)-restriction fragment length polymorphism technique, the allele and genotype distribution of SNP C677T in the MTHFR gene were investigated in both patients and controls Results: The frequencies of allele T (409% vs 304%, P = 0002, odds ration [OR] = 158, 95% confidence interval [CI]: 124–2 02) and mutant homozygote (TT) (183% vs 115%, P = 0023, OR = 172, 95% CI: 107–276) as well as carrier with allele (TT + CT) (634% vs 492%, P = 00005, OR = 179, 95% CI: 129–248) in infertile patients were significantly higher than those in controls After patient stratification, the significant differences in distribution of the SNP between each patient subgroup and control group still remained Conclusion: Our findings indicate that there is an association of SNP C677T in the MTHFR gene with male infertility, suggesting that this polymorphism might be a genetic risk factor for male infertility in Chinese men (Asian J Androl 2007 Jan; 9: 57–62)

Increased oxidative damage of sperm and seminal plasma in men with idiopathic infertility is higher in patients with glutathione S-transferase Mu-1 null genotype.

Abstract: Aim: To examine whether a relationship exists between glutathione S-transferase Mu-1 (GSTM1) gene polymorphism and the susceptibility of sperm and seminal plasma from patients with idiopathic infertility to oxidative stress. Methods: Fifty-two men with idiopathic infertility and 60 healthy fertile men were recruited to this study. GSTM1 gene polymorphism was determined by polymerase chain reaction (PCR) and both the infertile and control individuals were divided into GSTM1 null and GSTM1 positive groups according to their GSTM1 gene structure. We compared reactive oxygen species (ROS) generation, malondialdehyde (MDA), protein carbonyls and glutathione (GSH) concentrations, and glutathione S-transferase (GST) activity in seminal plasma and spermatozoa from infertile patients and controls with respect to GSTM1 genotype. Results: Significantly higher levels of oxidative stress and damage markers were found in idiopathic infertile men with the GSTM1 null genotype compared with those with the GSTM1 positive genotype. There was no significant difference in genotype distribution for the GSTM1 variant between the idiopathic infertile subjects and fertile subjects. Patients with the GSTM1 null genotype also had lower sperm concentrations than those with GSTM1 positive genotype. Conclusion: Our results suggest that the susceptibility of sperm and seminal plasma to oxidative stress is significantly greater in idiopathic infertile men with the GSTM1 null genotype compared with those possessing the gene. Therefore, in patients with idiopathic infertility, GSTM1 polymorphism might be an important source of variation in susceptibility of spermatozoa to oxidative damage. Edited by Prof. Junichi Fujii

Sperm lipid peroxidation and pro‐inflammatory cytokines

Abstract: Aim: To investigate if interleukin-6 (IL-6), interleukin-8 (IL-8), interleukin-10 (IL-10), interferon-gamma (IFN-α) or tumor necrosis factor-alpha (TNF-α) are able to stimulate the level of lipid peroxidation of sperm membranes, either alone or in the presence of leukocytes. Methods: Semen samples from normozoospermic donors were prepared by density gradient. The sperms were exposed to the indicated cytokines, at physiological and infection-inflammation concentrations, in the absence or presence of leukocytes. Lipid peroxidation of the sperm membranes was determined by measuring malondialdehyde (MDA) and 4-hydroxialkenals (HAE) formation. Results: TNF-α, IL-8 and IFN-α increased the level of sperm membrane lipid peroxidation when tested at physiological concentrations. At infection-inflammation concentrations, only IL-8 was able to produce a higher effect. When assayed in the presence of leucocytes, IL-8 and TNF-α showed a higher effect at infection-inflammation concentrations than at physiological concentrations. Finally, IL-8 showed a higher effect in the presence of leukocytes than in their absence at both physiological and infection-inflammation concentrations. TNF-α also showed a higher effect when assayed in the presence of leukocytes than in their absence, but only at infection-inflammation concentrations. There was no effect of IL-6 or IL-10 in any of the tested conditions. Conclusion: Several pro-inflammatory cytokines at physiological concentrations increase the level of lipid peroxidation of sperm membranes, which could be important for the sperm fecundation process. However, infection-inflammation concentrations of some cytokines, such as IL-8 and TNF-α, either alone or in the presence of leukocytes, could drive the lipid peroxidation of the spermatozoa plasma membrane to levels that can affect the sperm fertility capacity. Edited by Prof. Toshi Noce

Supramolecular organization of the sperm plasma membrane during maturation and capacitation

Abstract: Aim: In the present study, a variety of high resolution microscopy techniques were used to visualize the organization and motion of lipids and proteins in the sperm's plasma membrane. We have addressed questions such as the presence of diffusion barriers, confinement of molecules to specific surface domains, polarized diffusion and the role of cholesterol in regulating lipid rafts and signal transduction during capacitation. Methods: Atomic force microscopy identified a novel region (EqSS) within the equatorial segment of bovine, porcine and ovine spermatozoa that was enriched in constitutively phosphorylated proteins. The EqSS was assembled during epididymal maturation. Fluorescence imaging techniques were then used to follow molecular diffusion on the sperm head. Results: Single lipid molecules were freely exchangeable throughout the plasma membrane and showed no evidence for confinement within domains. Large lipid aggregates, however, did not cross over the boundary between the post-acrosome and equatorial segment suggesting the presence of a molecular filter between these two domains. Conclusion: A small reduction in membrane cholesterol enlarges or increases lipid rafts concomitant with phosphorylation of intracellular proteins. Excessive removal of cholesterol, however, disorganizes rafts with a cessation of phosphorylation. These techniques are forcing a revision of long-held views on how lipids and proteins in sperm membranes are assembled into larger complexes that mediate recognition and fusion with the egg.

Orchestration of occludins, claudins, catenins and cadherins as players involved in maintenance of the blood-epididymal barrier in animals and humans.

Abstract: Although spermatozoa are formed during spermatogenesis in the testis, testicular spermatozoa are immature and cannot swim or fertilize. These critical spermatozoal functions are acquired in the epididymis where a specific luminal environment is created by the blood-epididymal barrier; proteins secreted by epididymal principal cells bind to maturing spermatozoa and regulate the maturational process of the spermatozoa. In the epididymis, epithelial cell-cell interactions are mediated by adhering junctions, necessary for cell adhesion, and by tight junctions, which form the blood-epididymal barrier. The regulation of these cellular junctions is thought to represent a key determinant in the process of sperm maturation within the epididymis. Tight junctions between adjacent principal cells permit the formation of a specific microenvironment in the lumen of the epididymis that is essential for sperm maturation. Although we have made significant progress in understanding epididymal function and the blood-epididymal barrier, using animal models, there is limited information on the human epididymis. If we are to understand the normal and pathological conditions attributable to human epididymal function, we must clearly establish the physiological, cellular and molecular regulation of the human epididymis, develop tools to characterize these functions and develop clinical strategies that will use epididymal functions to improve treatment of infertility.

Seasonal variation in semen quality of swamp buffalo bulls (Bubalus bubalis) in Thailand.

Abstract: Aim: To test the hypothesis that season affects the semen quality of swamp buffalo (Bubalus bubalis) bulls used for artificial insemination (AI) under tropical conditions in Thailand, as it does in Bos taurus and Bos indicus. Methods: Clinical and andrological examinations, and monitoring of semen production and quality were carried out on five mature, healthy swamp buffalo AI bulls in Thailand from July 2004 to the end of June 2005. Sperm output, motility, morphology and plasma membrane integrity (PMI) were compared between three seasons of the year (rainy, i.e. July–October; winter, i.e. November–February; and summer, i.e. March–June) with distinct ambient temperature and humidity. Results: All bulls were diagnosed as clinically healthy and with good libido throughout the study. Ejaculate volume, pH, sperm concentration, total sperm number and initial sperm motility did not differ between seasons, whereas PMI and the relative proportion of morphologically normal spermatozoa were highest in summer and lowest in winter (P < 0.05). Buffalo age, week of collection and season influenced sperm morphology (P < 0.05–0.001). Among morphological abnormalities, only proportions of tail defects were affected by season, being highest in the rainy season and lowest in summer (P < 0.001). In conclusion, climatic changes did not seem to largely affect semen sperm output or viability. Although the proportions of PMI and tail abnormalities were affected by season, they were always below what is considered unacceptable for AI bull sires. Conclusion: Seasonal changes did not appear to cause deleterious changes in sperm quality in swamp buffalo AI-sires in tropical Thailand. Edited by Prof. Claude Gagnon

More than eight years' hands-on experience with the novel long-acting parenteral testosterone undecanoate.

Abstract: Testosterone (T) as a compound for treatment of T deficiency has been available for almost 70 years, but the pharmaceutical formulations have been less than ideal. Traditionally, injectable T esters have been used for treatment, but they generate supranormal T levels shortly after the 2-3 weekly injection interval. T levels then decline very rapidly, becoming subnormal during the days preceding the next injection. The rapid fluctuations in plasma T are subjectively experienced as disagreeable. T undecanoate (TU) is a new injectable T preparation with a considerably better pharmacokinetic profile. After two initial injections separated by a 6-week interval, the following intervals between two injections are generally 12 weeks, eventually amounting to a total of four injections per year. Plasma T levels with this preparation are nearly always in the range of normal men, as are its metabolic products estradiol and dihydrotestosterone (DHT). It reverses the effects of hypogonadism on bone and muscle and metabolic parameters, and on sex functions. It is suitable for male contraception. Its safety profile is excellent because of the continuous normalcy of plasma T levels. No polycythemia has been observed and no adverse effects on lipid profiles. Prostate safety parameters are well within reference limits. TU is a valuable treatment option of androgen deficiency.

Characterization and functions of beta defensins in the epididymis

Abstract: The epididymal beta-defensins have evolved by repeated gene duplication and divergence to encode a family of proteins that provide direct protection against pathogens and also support the male reproductive tract in its primary function. Male tract defensins also facilitate recovery from pathogen attack. The beta-defensins possess ancient conserved sequence and structural features widespread in multi-cellular organisms, suggesting fundamental roles in species survival. Primate SPAG11, the functional fusion of two ancestrally independent beta-defensin genes, produces a large family of alternatively spliced transcripts that are expressed according to tissue-specific and species-specific constraints. The complexity of SPAG11 varies in different branches of mammalian evolution. Interactions of human SPAG11D with host proteins indicate involvement in multiple signaling pathways.

Identification of epididymis‐specific transcripts in the mouse and rat by transcriptional profiling

Abstract: As part of our efforts to identify novel contraceptive targets in the epididymis we performed transcriptional profiling on each of the 10 and 19 segments of the mouse and rat epididymidis, respectively, using Affymetrix whole genome microarrays. A total of 17 096 and 16 360 probe sets representing transcripts were identified as being expressed in the segmented mouse and rat epididymal transcriptomes, respectively. Comparison of the expressed murine transcripts against a mouse transcriptional profiling database derived from 22 other mouse tissues identified 77 transcripts that were expressed uniquely in the epididymis. The expression of these genes was further evaluated by reverse transcription polymerase chain reaction (RT-PCR) analysis of RNA from 21 mouse tissues. RT-PCR analysis confirmed epididymis-specific expression of Defensin Beta 13 and identified two additional genes with expression restricted only to the epididymis and testis. Comparison of the 16 360 expressed transcripts in the rat epididymis with data of 21 other tissues from a rat transcriptional profiling database identified 110 transcripts specific for the epididymis. Sixty-two of these transcripts were further investigated by qPCR analysis. Only Defensin 22 (E3 epididymal protein) was shown to be completely specific for the epididymis. In addition, 14 transcripts showed more than 100-fold selective expression in the epididymis. The products of these genes might play important roles in epididymal and/or sperm function and further investigation and validation as contraceptive targets are warranted. The results of the studies described in this report are available at the Mammalian Reproductive Genetics (MRG) Database (http://mrg.genetics.washington.edu/).

Androgenic regulation of novel genes in the epididymis

Abstract: The epididymis is critically dependent on the presence of the testis. Although several hormones, such as retinoids and progestins, and factors secreted directly into the epididymal lumen, such as androgen binding protein and fibroblast growth factor, might play regulatory roles in epididymal function, testosterone (T) and its metabolites, dihydrotestosterone (DHT) and estradiol (E2), are accepted as the primary regulators of epididymal structure and functions, with the former playing the greater role. To ascertain the molecular action of androgens on the epididymis, three complementary approaches were pursued to monitor changes in gene expression in response to different hormonal milieux. The first was to establish changes in gene expression along the epididymis as androgenic support is withdrawn. The second was to determine the sequence of responses that occur in an androgen deprived tissue upon re-administration of the two metabolites of T, DHT and E2. The third was to study the effects of androgen withdrawal and re-administration on gene expression in immortalized murine caput epididymidal principal cells. Specific responses were observed under each of these conditions, with an expected major difference in the panoply of genes expressed upon hormone withdrawal and re-administration; however, some key common features were the common roles of genes in insulin like growth factor/epidermal growth factor and the relatively minor and specific effects of E2 as compared to DHT. Together, these results provide novel insights into the mechanisms of androgen regulation in epididymal principal cells.

Structure and function of epididymal protein cysteine-rich secretory protein-1.

Abstract: Cysteine-rich secretory protein-1 (CRISP-1) is a glycoprotein secreted by the epididymal epithelium. It is a member of a large family of proteins characterized by two conserved domains and a set of 16 conserved cysteine residues. In mammals, CRISP-1 inhibits sperm-egg fusion and can suppress sperm capacitation. The molecular mechanism of action of the mammalian CRISP proteins remains unknown, but certain non-mammalian CRISP proteins can block ion channels. In the rat, CRISP-1 comprises two forms referred to as Proteins D and E. Recent work in our laboratory demonstrates that the D form of CRISP-1 associates transiently with the sperm surface, whereas the E form binds tightly. When the spermatozoa are washed, the E form of CRISP-1 persists on the sperm surface after all D form has dissociated. Cross-linking studies demonstrate different protein-protein interaction patterns for D and E, although no binding partners for either protein have yet been identified. Mass spectrometric analyses revealed a potential post-translational modification on the E form that is not present on the D form. This is the only discernable difference between Proteins D and E, and presumably is responsible for the difference in behavior of these two forms of rat CRISP-1. These studies demonstrate that the more abundant D form interacts with spermatozoa transiently, possibly with a specific receptor on the sperm surface, consistent with a capacitation-suppressing function during sperm transit and storage in the epididymis, and also confirm a tightly bound population of the E form that could act in the female reproductive tract.

Frequency of Y chromosome microdeletions and chromosomal abnormalities in infertile Thai men with oligozoospermia and azoospermia.

Abstract: Aim: To investigate the possible causes of oligozoospermia and azoospermia in infertile Thai men, and to find the frequencies of Y chromosome microdeletions and cytogenetic abnormalities in this group. Methods: From June 2003 to November 2005, 50 azoospermic and 80 oligozoospermic men were enrolled in the study. A detailed history was taken for each man, followed by general and genital examinations. Y chromosome microdeletions were detected by multiplex polymerase chain reaction (PCR) using 11 gene-specific primers that covered all three regions of the azoospermic factor (AZFa, AZFb and AZFc). Fifty men with normal semen analysis were also studied. Karyotyping was done with the standard G- and Q-banding. Serum concentrations of follicle stimulating hormone (FSH), luteinizing hormone (LH), prolactin (PRL) and testosterone were measured by electrochemiluminescence immunoassays (ECLIA). Results: Azoospermia and oligozoospermia could be explained by previous orchitis in 22.3%, former bilateral cryptorchidism in 19.2%, abnormal karyotypes in 4.6% and Y chromosome microdeletions in 3.8% of the subjects. The most frequent deletions were in the AZFc region (50%), followed by AZFb (33%) and AZFbc (17%). No significant difference was detected in hormonal profiles of infertile men, with or without microdeletions. Conclusion: The frequencies of Y chromosome microdeletions and cytogenetic abnormalities in oligozoospermic and azoospermic Thai men are comparable with similarly infertile men from other Asian and Western countries. Edited by Prof. De-Yi Liu

Participation of epididymal cysteine-rich secretory proteins in sperm-egg fusion and their potential use for male fertility regulation

Abstract: Rat protein DE is an androgen-dependent cysteine-rich secretory protein (CRISP) synthesized by proximal epididymal regions DE, also known as CRISP-1, is localized on the equatorial segment of acrosome-reacted spermatozoa and participates in gamete fusion through binding to egg complementary sites Immunization of rats with DE inhibits fertility and sperm fusion ability, suggesting that DE represents a good epididymal contraceptive target Recombinant DE fragments and synthetic peptides revealed that DE binds to the egg via a 12-amino acid region of an evolutionarily conserved motif, Signature 2 (S2) The ability of other CRISP to bind to the rat egg was correlated with their S2 amino acid sequences Although testicular protein Tpx-1 (CRISP-2) was capable of binding to rodent eggs, human epididymal AEG-related protein (ARP) and helothermine (from lizard saliva) were not The S2 region presented only two substitutions in Tpx-1 and four in ARP and helothermine, compared with the DE S2, suggesting that this amino acid sequence was relevant for egg interaction Studies with Tpx-1 and anti-Tpx-1 revealed the participation of this protein in gamete fusion through binding to complementary sites in the egg In competition studies, DE reduced binding of Tpx-1 dose-dependently, indicating that both CRISP share the egg complementary sites That anti-DE and anti-Tpx-1 inhibit sperm-egg fusion while recognizing only the corresponding proteins, suggests functional cooperation between these homologous CRISP to ensure fertilization success These results increase our understanding of the molecular mechanisms of gamete fusion and contribute to the development of new and safer fertility regulating methods

Establishment of a high‐resolution 2‐D reference map of human spermatozoal proteins from 12 fertile sperm‐bank donors

Abstract: Aim: To extend the analysis of the proteome of human spermatozoa and establish a 2-D gel electrophoresis (2-DE) reference map of human spermatozoal proteins in a pH range of 3.5-9.0. Methods: In order to reveal more protein spots, immobilized pH gradient strips (24 cm) of broad range of pH 3-10 and the narrower range of pH 6-9, as well as different overlapping narrow range pH immobilized pH gradient (IPG) strips, including 3.5-4.5, 4.0-5.0, 4.5-5.5, 5.0-6.0 and 5.5-6.7, were used. After 2-DE, several visually identical spots between the different pH range 2-D gel pairs were cut from the gels and confirmed by mass spectrometry and used as landmarks for computer analysis. Results: The 2-D reference map with pH value from 3.5 to 9.0 was synthesized by using the ImageMaster analysis software. The overlapping spots were excluded, so that every spot was counted only once. A total of 3 872 different protein spots were identified from the reference map, an approximately 3-fold increase compared to the broad range pH 3-10 IPG strip (1 306 spots). Conclusion: The present 2-D pattern is a high resolution 2-D reference map for human fertile spermatozoal protein spots. A comprehensive knowledge of the protein composition of human spermatozoa is very meaningful in studying dysregulation of male fertility.

Seminal plasma anti-Müllerian hormone level correlates with semen parameters but does not predict success of testicular sperm extraction (TESE).

Abstract: Aim: To assess seminal plasma anti-Mullerian hormone (AMH) level relationships in fertile and infertile males. Methods: Eighty-four male cases were studied and divided into four groups: fertile normozoospermia (n = 16), oligoasthenoteratozoospermia (n = 15), obstructive azoospermia (OA) (n = 13) and non-obstructive azoospermia (NOA) (n = 40). Conventional semen analysis was done for all cases. Testicular biopsy was done with histopathology and fresh tissue examination for testicular sperm extraction (TESE) in NOA cases. NOA group was subdivided according to TESE results into unsuccessful TESE (n = 19) and successful TESE (n = 21). Seminal plasma AMH was estimated by enzyme linked immunosorbent assay (ELISA) and serum follicular stimulating hormone (FSH) was estimated in NOA cases only by radioimmunoassay (RIA). Results: Mean seminal AMH was significantly higher in fertile group than in oligoasthenoteratozoospermia with significance (41.5 ± 10.9 pmol/L vs. 30.5 ± 10.3 pmol/L, P < 0.05). Seminal AMH was not detected in any OA patients. Seminal AMH was correlated positively with testicular volume (r = 0.329, P = 0.005), sperm count (r = 0.483, P = 0.007), sperm motility percent (r = 0.419, P = 0.021) and negatively with sperm abnormal forms percent (r = –0.413, P = 0.023). Nonsignificant correlation was evident with age (r = –0.155, P = 0.414) and plasma FSH ( r = –0.014, P = 0.943). In NOA cases, seminal AMH was detectable in 23/40 cases, 14 of them were successful TESE (57.5%) and was undetectable in 17/40 cases, 10 of them were unsuccessful TESE (58.2%). Conclusion: Seminal plasma AMH is an absolute testicular marker being absent in all OA cases. However, seminal AMH has a poor predictability for successful testicular sperm retrieval in NOA cases. (Asian J Androl 2007 Mar; 9: 265–270)

Novel mutations in ubiquitin-specific protease 26 gene might cause spermatogenesis impairment and male infertility.

Abstract: Aim: To study the incidence of single nucleotide polymorphisms in ubiquitin-specific protease 26 (USP26) gene and its involvement in idiopathic male infertility in China. Methods: Routine semen analysis was performed. Infertility factors such as immunological, infectious and biochemical disorders were examined to select patients with idiopathic infertility. DNA was isolated from peripheral blood of the selected patients and control population, which were examined for mutations using polymerase chain reaction-single strand conformation polymorphism analysis. Furthermore, nucleotide sequences were sequenced in some patients and controls. Results: Of 41 infertile men, 9 (22.0%, P = 0.01) had changes in USP26 gene on the X chromosome. A compound mutation (364insACA; 460G→A) was detected in 8 patients (19.5%, P = 0.01) and a 1044T→A substitution was found in 1 patient (2.4%, P > 0.05). All three variations led to changes in the coding amino acids. Two substitutions predict some changes: 460G → A changes a valine into an isoleucine, and 1044T → A substitutes a leucine for a phenylalanine. Another insertion of three nucleotides ACA causes an insertion of threonine. No other changes were found in the remaining patients and fertile controls. Conclusion: The USP26 gene might be of importance in male reproduction. Mutations in this gene might be associated with male infertility, and might negatively affect testicular function. Further research on this issue is in progress. (Asian J Androl 2007 Nov; 9: 809–814)

AZF microdeletions and partial deletions of AZFc region on the Y chromosome in Moroccan men.

Abstract: Aim: To evaluate for the first time the frequency of Y chromosome microdeletions and the occurrence of the partial deletions of AZFc region in Moroccan men, and to discuss the clinical significance of AZF deletions. Methods: We screened Y chromosome microdeletions and partial deletions of the AZFc region of a consecutive group of infertile men (n = 149) and controls (100 fertile men, 76 normospermic men). AZFa, AZFb, AZFc and partial deletions of the AZFc region were analyzed by polymerase chain reaction (PCR) according to established protocols. Results: Among the 127 infertile men screened for microdeletion, four subjects were found to have microdeletions: two AZFc deletions and two AZFb+AZFc deletions. All the deletions were found only in azoospermic subjects (4/48, 8.33%). The overall AZFc deletion frequency was low (4/127, 3.15%). AZF microdeletions were not observed in either oligoasthenoteratozoospermia (OATS) or the control. Partial deletions of AZFc (gr/gr) were observed in a total of 7 of the 149 infertile men (4.70%) and 7 partial AZFc deletions (gr/gr) were found in the control group (7/176, 3.98%). In addition, two b2/b3 deletions were identified in two azoospermic subjects (2/149, 1.34%) but not in the control group. Conclusion: Our results suggest that the frequency of Y chromosome AZF microdeletions is elevated in individuals with severe spermatogenic failure and that gr/gr deletions are not associated with spermatogenic failure. (Asian J Androl 2007 Sep; 9: 674–678)

Protein phosphatase PP1γ2 in sperm morphogenesis and epididymal initiation of sperm motility

Abstract: The serine/threonine phosphatase (PP1) isoform PP1 gamma 2, predominantly expressed in the testis, is a key enzyme in spermatozoa. High PP1 gamma 2 catalytic activity holds motility in check in immature spermatozoa. Inhibition of PP1 gamma 2 causes motility initiation in immature spermatozoa and motility stimulation and changes in flagellar beat parameters in mature spermatozoa. The PP1 gamma 2 isoform is present in all mammalian spermatozoa studied: mouse, rat, hamster, bovine, non-human primate and man. We have now identified at least four of its regulatory proteins that regulate distinct pools of PP1 gamma 2 within spermatozoa. Our studies provide new insights into biochemical mechanisms underlying development and regulation of sperm motility. We hypothesize that changes in sperm PP1 gamma 2 activity as a result of phosphorylation and reversible binding of the regulatory proteins to the catalytic subunit are critical in the development and regulation of motility and the ability of sperm to fertilize eggs. Targeted disruption of the Ppp1cc gene, which encodes the PP1 gamma 1 or PP1 gamma 2 isoforms, causes male infertility in mice as a result of impaired spermiogenesis. Our observations suggest that, in addition to motility, the protein phosphatase PP1 gamma 2 might play an isoform-specific function in the development of specialized flagellar structures of mammalian spermatozoa.

Improved spontaneous erectile function in men with mild-to-moderate arteriogenic erectile dysfunction treated with a nightly dose of sildenafil for one year: a randomized trial.

Abstract: Aim: To test the hypothesis that sildenafil (50 mg nightly for one year) can improve spontaneous erectile function (EF) in men with mild-to-moderate arteriogenic erectile dysfunction (ED) responsive to erectogenic treatment. Methods: In a prospective open-label trial, 112 men with ED were randomized to sildenafil 50 mg nightly or sildenafil 50 or 100 mg as needed for 12 months, followed by one-month and 6-month non-medicated periods. Non-randomized, non-medicated men with ED were also assessed. The EF domain of the International Index of Erectile Function (IIEF EF) and the peak systolic velocity (PSV) of penile cavernous arteries were used to measure the efficacy. Results: After sildenafil treatment and a subsequent non-medicated month, IIEF EF was normal in 29 of 48 (60.4%, 95% confidence interval [CI]: 45.3–74.2%) of the nightly group vs. 4 of 49 (8.2%, 95% CI: 2.3–19.6%) of the as-needed group. PSV improved by 11.2 cm/s (95% CI: 4.7–21.4; P= 0.012) in the nightly group but only by 3.4 cm/s (−5.1–14.7; P= 0.435) in the as-needed group. IIEF EF normalized in 1 of 18 (5.6%, 95% CI: 0.1–27.3%) non-medicated men and the PSV declined slightly. Six months after treatment, the IIEF EF remained normal and PSV was stabilized in most (28/29, 97%) nightly group men who had initially normalized. Conclusion: Sildenafil nightly for one year resulted in ED regression that persisted well beyond the end of treatment, so that spontaneous EF was characterized as normal on the IIEF in most men. The results from this open-label, randomized trial warrant verification under double-blind, placebo-controlled conditions. Edited by Prof. Jae-Seung Paick

Age-related changes in seminal polymorphonuclear elastase in men with asymptomatic inflammation of the genital tract.

Abstract: Aim: To investigate age-related inflammatory events in the male genital tract. Methods: In a total of 4 265 randomly collected patients attending the andrological outpatient clinic of the Center for Dermatology and Andrology, University of Giessen, Germany, ejaculate volume, pH-value, sperm concentration, total and progressive sperm motility, concentration of polymorphonuclear (PMN) elastase, number of peroxidase-positive cells and fructose were measured and correlated with patient’s age. Results: While ejaculate volume, motility and fructose all correlated negatively with age, sperm concentration, PMN elastase and the pH-value showed a positive correlation. The prevalence of male genital tract inflammation (as defined by PMN elastase > 250 ng/mL) and its severity increased significantly. PMN elastase did not correlate with sperm motility. Fructose as a marker of seminal vesicle function showed a significant negative relationship with the PMN elastase levels, the number of peroxidase-positive cells and sperm motility. Conclusion: The significant increases of PMN-elastase levels as marker of male genital tract inflammation in older men appear to be indicative of age-related changes in local immunoregulatory mechanisms. Because there is no association of PMN elastase with sperm motility, a direct inhibitory effect of this enzyme can be excluded. (Asian J Androl 2007 May; 9: 299–304)

Localization of AKAP4 and tubulin proteins in sperm with reduced motility.

Abstract: Aim: To perform screening, related to A-kinase anchoring proteins 4 (AKAP4) and tubulin proteins, in spermatozoa with absent or severely reduced motility in order to detect the status of the fibrous sheath and the axonemal structure. Methods: An immunocytochemical study of tubulin, used as a positive control, and AKAP4 was carried out to detect the presence and the distribution of these proteins in different sperm samples. The morphological characteristics of sperm were studied by transmission electron microscope (TEM) and the results were elaborated using a formula reported in previous studies. PCR was carried out on DNA extracted from peripheral blood lymphocytes to analyse partial sequences of the Akap4 and Akap3 genes. Results: Immunolabelling of tubulin and AKAP4 showed different patterns, which led us to divide the patients into groups. In group I, the absence of AKAP4 and tubulin was revealed, although these patients did not show alterations in the Akap4/Akap3 binding site. TEM evaluation highlighted that a high presence of necrosis was associated with total sperm immotility. In group II, a regular AKAP4 and tubulin signal was present, although motility was reduced and TEM analysis revealed the presence of immaturity. In group III, in which a weak AKAP4 label associated with normal tubulin staining and reduced motility was observed, a severe disorganization of the fibrous sheath was highlighted by TEM. Conclusion: While the role of AKAP4 in sperm motility is unclear, absent or weak AKAP4-labelling seems to be associated with absent or weak sperm motility.

Role of the epididymis in sperm competition.

Abstract: Although it is generally understood that the testes recruited kidney ducts for reproductive function during the evolution of vertebrates, little is understood of the biological significance of the adaptation. In the context of the evolution of the mammalian epididymis, this report provides evidence that a major role of the epididymis is to enhance a male's chance of achieving paternity in a competitive mating system. A unique example of sperm cooperation in monotremes is used as evidence that the epididymis produces sperm competition proteins to form groups of 100 sperm into bundles that have a forward motility nearly thrice that of individual spermatozoa. As it required 3-h incubation in vitro under capacitation conditions to release motile sperm from the bundles, it is suggested that the monotremes provide an example of capacitation that is quite different from capacitation in higher mammals. It is suggested that variation between species in the intensity of sperm competition could explain the variation that occurs between species in the amount of post-testicular sperm maturation and storage in the epididymis, an explanation of why the human epididymis does not play as important a role in reproduction as the epididymis of most mammals.

Yohimbine in the treatment of orgasmic dysfunction.

Abstract: Aim: To study the effect of yohimbine in the treatment of men with orgasmic dysfunction. Methods: A 20-mg dose of yohimbine was first given to 29 men with orgasmic dysfunction of different aetiology in the clinic. Patients were then allowed to increase the dose at home (titration) under more favourable circumstances. The outcome and side effects were subsequently assessed. Results: The patients were classified into three groups of orgasmic dysfunction: primary complete (13), primary incomplete (8) and secondary (8). Nocturnal emissions were present in 75%, 40% and 50% of patients in the above groups, respectively (overall average 62%). The men presented because of fertility problems (52%) or because they wanted to experience the pleasure of orgasm (48%). Of the 29 patients who completed the treatment, 16 managed to reach orgasm and were able to ejaculate either during masturbation or sexual intercourse. A further three achieved orgasm, but only with the additional stimulation of a vibrator. A history of preceding nocturnal emissions was present in 69% of the men in whom orgasm was induced but only 50% who failed treatment. Of the patients, two have subsequently fathered children (one set of twins) and another 3 men were also cured. Side effects were not sufficient to cause the men to cease treatment. Conclusion: Yohimbine is a useful treatment option in orgasmic dysfunction.