Epididymis Of Men Research Articles

Differential gene expression profiles of human efferent ducts and proximal epididymis.

Gene expression patterns along the epididymis are established by specific transcription factor networks that coordinate region-specific functions. In rodents, the epididymis can be divided in up to 19 segments. Based on gross anatomy, the human epididymis is divided into caput, corpus, and cauda segments together with efferent ducts that occupy the proximal part of this organ. To determine to which extent gene expression pattern is segmented along the efferent ducts and the proximal region of the epididymis in men of reproductive age. Epididymal transcriptome profiling was performed on eight distinct regions from three donors. Microarray analysis was performed on a gene-chip microarray. Differentially expressed genes (DEGs)>2-fold change (P<.05) were clustered in relation to their intensity profiles. Overrepresented biological functions from gene ontology were searched using DAVID 6.8. Expression profiles were validated by qRT-PCR quantification of selected genes. There were no DEGs among segments 1-3 of efferent ducts region neither among segments 4-6 of the caput epididymis. 1058 DEGs were identified between efferent ducts and the epididymis, whereas 444 and 846 DEGs distinguished the caput from the corpus (section 7) and cauda (section 8) epididymis, respectively. A total of 131 DEGs were detected between corpus (7) and cauda (8) transcriptomes. Up-regulated DEGs in the efferent ducts were predominantly related to cilium assembly/movement and cell differentiation. Fertilization, defense, and immune responses were associated with caput epididymis (4-6), while spermatogenesis and protein binding were found all along the epididymis (4-8). The proximal human epididymis is exclusively occupied by efferent ducts with a distinct DEG profile compared with the downstream epididymal segments. Moreover, gene expression profiling revealed two regions in the human epididymis: the caput and the distal corpus/cauda region. Human epididymal transcriptome reveals limited DEGs, and efferent ducts have a distinct DEGs profile.

Human spermatozoa and temperature: the elephant in the room.

Men are notable for low sperm production, relative to that of other large mammals, and often inferior morphology and motility of their spermatozoa. The extent to which temperature plays a role in this picture has been a moot point. However, animal experiments suggest that an increased scrotal temperature of approximately +4°C brought by inguinal clothing has a negative impact on the germinal epithelium and on the epididymis in man. In two animal species with inguinal testes, their transposition to the abdomen, raising the testis temperature by a modest approximate 1.5°C brought reduced sperm production and abnormalities of spermiogenesis (distorted sperm nuclei, shared acrosomes), a picture seen commonly in man alongside morphologically normal spermatids. Reflection of the scrotal epididymis to the abdomen in laboratory animals did not inhibit sperm maturation there, but the consequences of this for other epididymal parameters are mirrored in several features seen in man. In addition to the typically puny form of the human cauda, these include often rapid epididymal sperm transit, rapid capacitation in vitro, a poor sperm reserve (as reflected in the steep decline in sperm numbers in successive ejaculates), and not least, the cauda's failure to maintain the viability of spermatozoa there (reflected in both their mixed potential for motility and the negative outcome of abstinence). Because the number of competent spermatozoa inseminated relates to prompt fertilization and/or incidence of pregnancy in some animal models, the negative effects of scrotal temperature may be an important factor in the need for an average of approximately five cycles of unprotected intercourse in order to establish pregnancy in human females.

Epidermal growth factor regulates connexin 43 in the human epididymis: role of gap junctions in azoospermia

Gap junctions (GJs) allow for direct communication between adjacent cells. They are composed of connexons consisting of transmembrane proteins, connexins (Cxs). The objectives of this study were to determine if GJ proteins GJA1 (Cx43), GJB1 (Cx32) and GJB2 (Cx26) are present in the epididymis of men with a normal epididymis, to assess whether or not Cx expression and localization are altered in azoospermic patients, and to determine if epidermal growth factor (EGF) regulates GJA1 expression. Epididymides were obtained from men with localized testis cancer with active spermatogenesis and histologically normal epididymal tubule (group 1), men with non-obstructive azoospermia secondary to Sertoli-cell only syndrome (group 2) and from azoospermic men with normal spermatogenesis and epididymal obstruction (group 3). Epididymides were subdivided into three segments: caput, corpus and cauda. Quantitative real-time RT-PCR was performed to assess GJA1, GJB1, GJB2 and EGF receptor (EGFR) mRNA levels in epididymides from patients from each group (all n=3, except n=1 for caput blockage). A human caput epididymal cell line was then used to determine the role of EGFR signaling on the regulation of human epididymal GJA1. Real-time RT-PCR analysis revealed that GJA1, GJB1, GJB2 and EGFR were expressed along the human epididymis. In the cauda epididymidis of group 2 and 3 men, we observed a significant decrease in GJA1 (P=0.0456 and P=0.0465, respectively) and GJB1 (P=0.0450 and P=0.0497, respectively) mRNA levels when compared with group 1 men. We also observed a decrease in EGFR mRNA levels (P=0.0358) in the cauda epididymidis of group 3 men when compared with group 1. Immunocytochemistry revealed that in the epididymis, GJA1 and EGFR were localized between basal and principal cells and between adjacent principal cells. In group 2 and 3 patients, however, we noted a dramatic increase in cytosolic immunostaining for both GJA1 and EGFR in both principal and basal cells. Using a human caput epididymal cell line derived from fertile men, we demonstrated that changes in GJA1 phosphorylation could be regulated by EGF (P=0.015) and the extracellular regulated kinase 1/2 signaling pathway (P=0.03). Furthermore, while the phosphoinositide-3-kinase (PI3K)/AKT signaling pathway did not alter GJA1 phosphorylation, treatment with PI3K/AKT inhibitor LY294002 significantly (P=0.024) inhibited the EGF-stimulated increase in GJA1 total protein levels at 24 h. Immunolocalization indicated that loss of PI3K/AKT signaling was associated with increased cytosolic localization of Cx43 in this cell line. Together, these data suggest that in azoospermic men decreased expression of EGFR may be responsible for decreasing GJA1 levels and increasing its cytosolic localization via the PI3K/AKT signaling pathway.

The Immunoexpression of FSH-R in the Ductuli Efferentes and the Epididymis of Men and Rat: Effect of FSH on the Morphology and Steroidogenic Activity of Rat Epididymal Epithelial Cells In Vitro

The Sertoli cells were regarded as the only target for FSH in male reproductive system. The expression of FSH receptor (FSH-R) was detected also in epithelial cells of the caput epididymis of rat and monkey. We showed in the immunohistochemistry study the expression of FSH-R in rat and human ductuli efferentes and the caput, corpus, and cauda epididymis, moreover, by Western blot analysis in the caput and cauda epididymis of rat. Additionally, we presented that the morphology of rat epididymal epithelial cells in vitro was affected by FSH, and FSH stimulation resulted in the increase of 17β-estradiol synthesis by rat caput epididymal cells in dose-depended manner. In conclusion, the identification of FSH receptors in human and rat epididymides supports our results that the epididymis is a target organ not only for LH but additionally for FSH. On the basis of the results we showed for the first time that morphology of epididymal epithelial cells and epididymal steroidogenesis can be regulated by FSH.

Histology of the epididymis in men with obstructive infertility

The histology of different regions of human epididymis in men undergoing vasoepididymostomy to correct epididymal obstruction was studied. The data indicate major degenerative changes in intertubular connective tissue and in the epididymal epithelium. These include increase in connective tissue thickness and its infiltration by leucocytes in some cases, decrease in tubular diameter, degeneration and/or vacuolation of cytoplasm of nonciliated cells of efferent duct and principal cells of epididymis and presence of multinucleate giant cells in the epididymal lumen. These histological abnormalities are discussed in relation to the role such epididymis can play in sperm maturation following vasoepididymostomy.

ICSI outcomes in obstructive azoospermia: influence of the origin of surgically retrieved spermatozoa and the cause of obstruction

Spermatozoa can be retrieved from the testis and epididymis of men with obstructive azoospermia (OA) and used for ICSI. However, it is unknown whether the outcome of ICSI depends on the cause of obstruction or the origin of surgically retrieved spermatozoa. A cohort of 171 men with OA and normal spermatogenesis were included in this retrospective study. They were divided into three groups according to the site and origin of obstruction: 83 men had congenital bilateral absence of vas deferens; 55 and 33 had acquired epididymal and deferent duct obstructions, respectively. The outcome of 368 ICSI cycles was determined and compared according to the origin of spermatozoa: epididymal (n = 253) or testicular (n = 115). Fertilization and clinical pregnancy rates did not differ between spermatozoa of different origin (58.9% versus 51.9% and 22.1% versus 24.3% with epididymal and testicular spermatozoa, respectively). However, the miscarriage rate was significantly higher for testicular spermatozoa (35.7% versus. 12.5% P < 0.05, chi2 test). Findings were similar whatever the aetiology of the OA. This study suggests that the use of testicular spermatozoa, even those generated during normal spermatogenesis, alters embryonic development and that epididymal spermatozoa should be preferentially used, irrespective of the aetiology of OA.

Ultrastructural changes in the efferent duct and epididymis of men with obstructive infertility

Ultrastructural changes in the efferent duct and in different regions of the epididymis in men with obstructive azoospermia were compared with corresponding tissues collected from men of proven fertility who underwent castration due to malignancy of the prostate. Major degenerative changes were seen in the efferent duct and the caput epididymidis of men with obstruction at the caput epididymidis which may have been induced by fluid pressure due to defective absorption of testicular fluid in the caput epididymidis. These degenerative changes included decrease in tubular and lumen diameter of the caput and the cauda epididymides, decrease in height of the stereocilia, reduction in rough endoplasmic reticulum and Golgi material, and presence of lipofuscin and osmiophilic dense bodies. The degenerative changes were less when the site of obstruction was in the cauda epididymidis since fluid reabsorption would continue to take place normally in the caput epididymidis. In men who had undergone vasoepididymostomy (VEA), the ejaculated spermatozoa showed a high percentage of morphological abnormalities which may have occurred due to adverse effects of long-term obstruction on spermatogenesis.

Penetration of zona-free hamster oocytes using human sperm aspirated from the epididymis of men with congenital absence of the vas deferens: comparison with human in vitro fertilization

To assess the ability of sperm aspirated from the epididymis of men with congenital absence of the vas deferens to penetrate zona-free hamster oocytes. To directly compare the performance of human epididymal sperm in the zona-free hamster oocyte sperm penetration assay (SPA) with the results of human in vitro fertilization (IVF). Sperm penetration assay was carried out with epididymal sperm retrieved microsurgically, and with ejaculated sperm obtained from fertile donors (internal controls). For direct comparison, SPA was performed with the same epididymal sperm sample used for IVF. Men with congenital absence of the vas deferens undergoing sperm aspiration as part of their infertility treatment and control donors who provided ejaculated sperm. Epididymal sperm penetrated SPA with a score of 0% to 30%. The SPA scores for internal controls using ejaculated sperm was 30% to 71%. Linear regression analysis of the association between penetration scores in SPA and fertilization rate in IVF indicated a positive correlation that was highly significative. These findings using SPA confirm previous reports on the fertilizing potential of human epididymal sperm and its ability to produce normal pregnancies. The good correlation between SPA and human IVF using epididymal sperm suggest that SPA is an excellent bioassay to test laboratory experimental conditions for improving fertilizing capacity of human epididymal sperm.

Histochemical Localization and Quantification of α-Glucosidase in the Epididymis of Men and Laboratory Animals1

The seminal marker of epididymal function alpha-1, 4-glucosidase was localized histochemically in the cytoplasm of the efferent duct epithelium and the brush border of the entire length of the human epididymis. Quantification using the specific inhibitor castanospermine revealed strongest activity in the corpus and cauda regions. Selective inhibition of the brush border enzyme activities by maltotriose identified these as the neutral isoenzymes. Despite detection of alpha-glucosidase in the renal tubules of all the animals studied, the enzyme was not detectable in epididymides of hamsters or mice. In rabbits and monkeys, it was absent from the entire brush border but present weakly in the cytoplasm of the proximal epididymides. An enzyme distribution pattern similar to that in the human epididymis was found in rats, except for the absence of histochemical staining at pH 6.5 from the initial segment and distal cauda epididymidis. Experiments in which endogenous testosterone was depleted in rats demonstrated the dependence of epididymal alpha-glucosidase on androgen, albeit with a low sensitivity. This study suggests the rat to be a suitable model for the investigation of the role of epididymal alpha-glucosidase in fertility.

Autoradiographic Studies of the Testis and the Epididymis in Man After Incubation with Radioactive Zinc in Vitro

The spermatozoa in man have been found to have a particularly high content of zinc compared to other tissues (MAWSON & FISCHER 1953 and BIRNBAUM, HALL & LEE 1961). Very little, however, seems to be known about the localization of zinc in the male reproductive organs and of this physiologic importance. The present investigations on the distribution of zinc in the testis and in the epididymis were carried out in an attempt to gain further information concerning this matter. Autoradiographic studies on the testes in rats by WETTERDAL (1958) demonstrated that the 66Zn administered was concentrated in the seminiferous tubules. Scintillation measurements and autoradiography further indicated that the spermatozoa took up the isotope in the seminiferous tubules and with a high amount of 05Zn were transported through the sperm transport system to the ejaculate. MILLAR, ELCOATE, FISCHER & MAWSON (1960) suggested that the incorporation of large amounts of zinc in the spermatozoa is essential for their development and for the maintenance of the germinal epithelium.