Molecular perspective concerning fluoride and arsenic mediated disorders on epididymal maturation of spermatozoa: A concise review

Epididymis is a complex tubular structure of male reproductive system where spermatozoa undergo maturation and gain the fertilizing ability. Epididymal pseudostratified columnar epithelium with different cell types play imperative role by their secretory properties and enrich the luminal microenvironment necessary for achieving spermatozoal motility. During epididymal transit several secretory proteins like P26h, SPAG11, HSPD1 and many others are deposited on spermatozoal surface. At the same time spermatozoal proteins are also modified in this intraluminal milieu, which include cyritestin, fertilin, CE9 and others. Natural and anthropogenic activities disclose various environmental pollutants which affect different physiological systems of animals and human being. Likewise, reproductive system is also being affected. Fluoride causes structural alterations of caput and cauda segments of epididymis. Redox homeostasis and functional integrity are also altered due to diminished activities of SOD1, GR, Crisp2, Lrp2 and other important proteins. On the contrary arsenic affects mostly on cauda segment. Redox imbalance and functional amendment in epididymis have been observed with arsenic revelation as evidenced by altered genomic appearance of SOD, GST, catalase, Ddx3Y, VEGF and VEGFR2. This review is dealt with structure-function interplay in normal epididymal spermatozoal maturation along with subsequent complications developed under fluoride and arsenic toxicities.

Persistence of Zika virus RNA in the epididymis of the murine male reproductive tract

Zika virus (ZIKV) can infect developing fetuses in utero and cause severe congenital defects independent of route of maternal infection. Infected men can shed ZIKV RNA in semen for over six months. Whether prolonged viral RNA shedding in semen indicates a persistent infection in the male reproductive tract is unknown. We hypothesized that if ZIKV establishes a persistent infection in the male reproductive tract (MRT), then immunosuppressant treatment should stimulate ZIKV replication and seminal shedding. Male mice were infected with ZIKV and immunosuppressed when they shed viral RNA but not infectious virus in ejaculates. Following immunosuppression, we did not detect infectious virus in ejaculates. However, we did detect ZIKV positive and negative sense RNA in the epididymal lumens of mice treated with cyclophosphamide, suggesting that ZIKV persists in the epididymis. This study provides insight into the mechanisms behind ZIKV sexual transmission, which may inform public health decisions regarding ZIKV risks.

Assessment of progesterone synthesis and its regulation role on dihydrotestosterone secretion in sheep epididymis

Progesterone (P4) is an anti-androgen compound whose role in sperm maturation and functionality remains unclear in sheep. Here, we aimed to investigate the regulation mechanism of P4 on the epididymal secretion of dihydrotestosterone (DHT). To this end, we performed enzyme-linked immunosorbent assays, immunohistochemical staining, western blotting, and quantitative real-time polymerase chain reaction to detect P4 concentration as well as StAR, P450scc, and 3β-HSD expression in sheep epididymis. Besides, cauda epithelial cells were cultured at different concentrations of P4 (10^-9-10^-5 g ml^-1) as well as with or without the P4 receptor (PGR) inhibitor RU486 (10^-7 M) or the PI3K-AKT inhibitor LY294006 (10^-7 M) to explore the effect of P4 on DHT secretion and the underlying regulatory mechanism. The results showed that the caput, corpus, and cauda of sheep epididymis could synthesize P4 but had different synthesis ability. The PGR expression levels were the highest in the cauda, followed by the corpus. In vitro cell culture showed that P4 inhibition of DHT secretion and 5α-reductase 1 and 2 expression in epididymal epithelial cells could be moderately mitigated by RU486 but not by LY294002. Our results indicated that the paracrine and autocrine P4 could affect the secretion of DHT in epididymal cells through PGR. Overall, this study provides new data regarding the involvement of P4 in sperm maturation and functionality in sheep.

Exposure to epididymal extracellular vesicles enhances immature sperm function and sustains vitality of cryopreserved spermatozoa in the domestic cat model

PURPOSE

Extracellular vesicles (EVs) secreted by the epididymal epithelium transfer key factors to maturing spermatozoa. Using an in vitro system previously developed in our laboratory, the objective was to (1) characterize the impact of EV exposure on the fertilizing ability and developmental potential of immature sperm cells from the caput epididymidis and (2) examine the benefit of EV exposure to restore vitality of mature spermatozoa from the cauda epididymidis after freezing-thawing.

METHODS

EVs were isolated from entire epididymides and collected into pellets via ultracentrifugation. Immature spermatozoa from adult cats were isolated from the caput epididymis and incubated with EVs prior to in vitro fertilization. Similarly, mature spermatozoa were isolated from the cauda segment and cryopreserved prior to EV exposure and subsequent analysis of motility and developmental potential after fertilization.

RESULTS

EV exposure did not affect the percentage of caput sperm penetration; however, it improved the fertilizing ability (faster pronuclear apposition) and the developmental potential (higher proportions of morula-blastocysts) of those immature sperm cells. While EV exposure was beneficial to the frozen-thawed sperm motility, it did not significantly improve the fertilizing ability and the developmental potential.

CONCLUSIONS

Epididymal EVs contain multiple factors contributing to immature sperm function, specifically enhancing the ability to complete a faster pronuclear apposition with subsequently improved early embryonic development. Supplementation was also beneficial to the motility of spermatozoa that had undergone cryopreservation. Those new findings could lead to new options for male fertility treatment in animal models and humans.

Leiomyoadenomatoid tumors: A type of rare benign epididymal tumor

Primary tumors of the epididymis are mostly benign in nature, and the most common type is adenomatoid tumors followed by leiomyomas. Leiomyoadenomatoid tumors are very rare benign epididymal neoplasms composed of two components: gland-like structures lined by cuboidal cells and bundles of smooth muscle components. The goal of treatment is testicular-preserving surgery. A preoperative and intraoperative evaluation plays an important role in proper management. To the best of our knowledge, few cases have been reported in the literature. We report a case of a right epididymal tail leiomyoadenomatoid tumor in a 49-year-old male who underwent trans-scrotal exploration and tumor excision.

Deficiency for Lcn8 causes epididymal sperm maturation defects in mice

Lipocalin family members, LCN8 and LCN9, are specifically expressed in the initial segment of mouse caput epididymis. However, the biological functions of the molecules in vivo are yet to be clarified. In this study, CRISPR/Cas9 technology was used to generate Lcn8 and Lcn9 knockout mice, respectively. Lcn8-/- and Lcn9-/- male mice showed normal spermatogenesis and fertility. In the cauda epididymis of Lcn8-/- male mice, morphologically abnormal sperm was increased significantly, the proportion of progressive motility sperm was decreased, the proportion of immobilized sperm was elevated, and the sperm spontaneous acrosome reaction (AR) frequency was increased. Conversely, the knockout of Lcn9 did not have any effect on the ratio of morphologically abnormal sperm, sperm motility, and sperm spontaneous AR frequencies. These results demonstrated the role of LCN8 in maintaining the sperm quality in the epididymis, and suggested that the deficiency of LCN8 leads to epididymal sperm maturation defects.

Epididymal tail solid-surface vitrification as an effective method for domestic cat sperm cryobanking

This study aimed to describe the viability of domestic feline spermatozoa after epididymal tail vitrification. For this, 10 pairs of testis-epididymis complexes were used. The epididymal tails were vitrified using the solid-surface vitrification (SSV) method, in which two vitrification media containing ethylene glycol (EG) 40% or glycerol (GLY) 40% were tested. Vitrification with the presence of EG resulted in better results for all sperm motility parameters (motility, vigour and CASA) compared with GLY (P < 0.05). There were no statistical differences for sperm viability and acrosome integrity, plasma membrane integrity, or overall health of morphologically normal sperm before or after vitrification among experimental groups. In conclusion, epididymal tail vitrification appears to be a suitable method for long-term storage of cat sperm, especially if the procedure is performed with EG as the cryoprotectant.

The process of testicular regression also impacts the physiology of the epididymis of the bat Molossus molossus, although with a delay in epididymal response due to sperm storage

Responsible for post-testicular maturation, concentration, protection and sperm storage, the epididymis is an organ that can be easily subdivided into three segments: caput, corpus and cauda. Each epididymal region displays different morphology and functions within the sperm maturation process. Despite the great importance of this organ, studies on its morphology and hormonal control in bats remain scarce. Thus, the aim of this study was to morphologically analyze the epididymis of the bat Molossus molossus (Chiroptera: Molossidae), in order to evaluate its morphological and morphometric variations, as well as some aspects of its hormonal control during the annual reproductive cycle. For this purpose, 60 sexually adult males were used in this study, comprising five specimens collected monthly for one year to form 12 sample groups. The epididymis was subjected to morphological, morphometric and immunohistochemical analyses. The results demonstrated that the processes of total testicular regression and posterior recrudescence suffered by M. molossus also impacts the physiology of the epididymis, however, a delay in the epididymal response is seen due to the storage of sperm. Similar to other mammals, the epididymis of M. molossus has a large predominance of principal and basal cells. The epididymal seasonal variations appear to be directly correlated to rainfall and photoperiod, but not to temperature. Meanwhile, epididymal physiology appears to be regulated, at least partially, by the expression of the androgen receptor in epithelial cells, which has agonist effects on cell proliferation.

Seminal plasma Alters surface Glycoprofile of dromedary camel cryopreserved epididymal spermatozoa

The high viscosity of Camelidae semen continues to present a major impediment for its application in assisted reproduction technology. The exposure of epididymal spermatozoa (ES) to seminal plasma (SP) may provide an approach to enhance the development of assisted reproductive techniques in these important domestic species. Since the sperm glycocalyx plays a key role in reproduction we aimed to evaluate whether SP exposure modifies the surface glycosylation patterns of cryopreserved dromedary ES. Epididymal sperm was collected through retrograde flushing of the cauda epididymidis that were obtained from orchidectomized mature dromedary bulls. The collected samples were then cryopreserved after dilution with a tris citrate clarified egg yolk extender, with and without the supplementation of 15% SP. Post-thaw carbohydrate surface profiles of both control and SP-treated spermatozoa were analyzed using 15 fluorescent lectins. Morpho-functional properties were also investigated via computer assisted sperm analysis. Lectin-binding analysis of the glycocalyx in control sperm revealed the presence of (1) N-glycans terminating with lactosamine (Con A, PHA-L, and RCA₁₂₀), in both acrosomal and tail regions. Whilst (2) α2,3-/α2,6-linked sialic acids (MALII, SNA), and O-linked glycans terminating with a single N-acetylgalactosamine residue (Tn antigen) (HPA, SBA) along with galactoseβ1,3N-acetylgalactosamine (T antigen) (PNA) were observed in the acrosomal cap. The expression of both N-acetylglucosamine (sWGA and GSA II) and terminalαgalactose (GSA I-B₄) residues was also noted in the acrosomal cap region of control sperm. Compared with controls, SP treated samples displayed: 1) the appearance of bisected di-triantennary complex-type N-glycans (PHA-E), terminating with lactosamine, as well as an increase of O-glycans terminating with Tn and T antigens in both the acrosomal and tail regions; 2) an increase in glycans containing α2,6-linked sialic acid, N-acetylglucosamine, and αgalactose in the tail region. The cytoplasmic droplets of both control and seminal plasma-treated sperm bound Con A, PHA-E, PHA-L, RCA₁₂₀, HPA, PNA, sWGA, GSA I-B₄, and GSA II. These results indicate that SP treatment affects the glycan composition of the dromedary camel ES glycocalyx. More comprehensive studies are required in order to evaluate the fertilization capacity of SP-treated ES in order to facilitate its application in dromedary camel assisted reproduction technology.

Differential abundances of AQP3 and AQP5 in reproductive tissues from dogs with and without cryptorchidism

Aquaporins (AQPs) are integral transmembrane proteins facilitating transport of water and small solutes, such as glycerol and urea, between cells. In male reproductive tracts, AQPs maintain a milieu conducive for sperm formation, maturation, and storage. The aim of this study was to clarify effects of testicular and epidydimal function on male fertility by investigating localisation and abundances of AQP3 and AQP5 in testes and epididymal segments from dogs with and without unilateral cryptorchidism. Immunohistochemistry results indicated AQP3 and AQP5 have different distribution patterns in reproductive tissues of dogs with and without unilateral cryptorchidism. The AQP3, an aquaglyceroprotein, is present in different germ and Sertoli cells in testis of dogs without cryptorchidism. The AQP5 protein was not detected in germ cells but was present in Sertoli and Leydig cells and in endothelia of blood vessels. In cryptorchid dogs, AQP3 was detected in early-developing germ and Sertoli cells, and AQP5 had a distribution pattern similar to testes of dogs without cryptorchidism. In the epididymis, AQP3 and AQP5 were localised in epithelial cells of dogs with and without cryptorchidism in a cell-specific manner. The AQP3 and AQP5 protein was in larger abundance in the gonads from dogs with and without cryptorchidism. In contrast, AQP3 and AQP5 abundance increased in each segment of the cryptorchid epididymis, likely as a compensatory mechanism associated with the pathologic condition. These results indicate involvement of AQP3 and AQP5 in spermatogenesis and sperm maturation. Results from the present study indicate dogs are a useful for comparative reproductive biology studies.

Estrogens and development of the rete testis, efferent ductules, epididymis and vas deferens

Estrogen has always been considered the female hormone and testosterone the male hormone. However, estrogen's presence in the testis and deleterious effects of estrogen treatment during development have been known for nearly 90 years, long before estrogen receptors (ESRs) were discovered. Eventually it was learned that testes actually synthesize high levels of estradiol (E2) and sequester high concentrations in the reproductive tract lumen, which seems contradictory to the overwhelming number of studies showing reproductive pathology following exogenous estrogen exposures. For too long, the developmental pathology of estrogen has dominated our thinking, even resulting in the "estrogen hypothesis" as related to the testicular dysgenesis syndrome. However, these early studies and the development of an Esr1 knockout mouse led to a deluge of research into estrogen's potential role in and disruption of development and function of the male reproductive system. What is new is that estrogen action in the male cannot be divorced from that of androgen. This paper presents what is known about components of the estrogen pathway, including its synthesis and target receptors, and the need to achieve a balance between androgen- and estrogen-action in male reproductive tract differentiation and adult functions. The review focuses on what is known regarding development of the male reproductive tract, from the rete testis to the vas deferens, and examines the expression of estrogen receptors and presence of aromatase in the male reproductive system, traces the evidence provided by estrogen-associated knockout and transgenic animal models and discusses the effects of fetal and postnatal exposures to estrogens. Hopefully, there will be enough here to stimulate discussions and new investigations of the androgen:estrogen balance that seems to be essential for development of the male reproductive tract.

Cadmium induced inflammation and apoptosis of porcine epididymis via activating RAF1/MEK/ERK and NF-κB pathways

Cadmium (Cd) was a serious heavy metal pollutant. Cd exposure will cause damage to reproductive organs. It was largely unknown whether Cd exposure caused inflammation and apoptosis in epididymis. In this study, we established models of Cd exposure in swine, and the apoptotic level of epididymis was detected by in situ TUNEL fluorescence staining assay, the results showed that Cd exposure significantly increased TUNEL-apoptosis index. Furthermore, the results of qRT-PCR and Western blot showed that Cd activated the proto-oncogenic serine/threonine kinase-1 (RAF1)/mitogen-activated protein kinase (MEK)/extracellular signal-regulated kinase (ERK) signal pathway (RAF1/MEK/ERK) and led to the subsequent up-regulation of the nuclear factor-κB (NF-κB), tumor necrosis factor α (TNF-α), cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), interleukin-1β (IL-1β), interleukin-6 (IL-6), interleukin-8 (IL-8), caused inflammation in epididymis. NF-κB inflammation pathway also mediated the tumor protein P53 (P53) and indirectly activated the Cytochrome c (Cytc), B-cell lymphoma-2 (Bcl-2), Bcl-2-Associated X protein (Bax), Caspase 3, Caspase 9. In summary, we believed that the RAF1/MEK/ERK pathway came into play in the apoptosis of epididymal tissues exposed to Cd by activating the NF-κB Inflammation pathway, followed by activation of the mitochondrial apoptotic pathway. This study provides more abundant data for exploring the reproductive toxicity of Cd.

Cryopreservation of Spix's yellow-toothed cavy epididymal sperm using Tris- and coconut water-based extenders supplemented with egg yolk or Aloe vera

Addressing the establishment of biobanks for the conservation of wild hystricomorph rodents' germplasm, we verified the effects of different extenders and distinct concentrations of non-permeant cryoprotectants on the sperm parameters of Spix's yellow-toothed cavies. Nine testis-epididymis complexes were used for sperm collection by retrograde washing using Tris or a powdered coconut water extender (ACP®-116c). Spermatozoa were diluted and frozen with the same extenders supplemented with egg yolk or Aloe vera at a 10% or 20% concentration. After recovery and cryopreservation, all samples were evaluated for sperm kinetic parameters, morphology, membrane integrity, osmotic response, and sperm-binding capability using an egg yolk perivitelline membrane assay. After recovery, no differences were observed between Tris and ACP®-116c that provided 515.4 × 10⁶ sperm/mL and 561.6 × 10⁶ sperm/mL, presenting >65% motile sperm, respectively. After cryopreservation, most effective preservation of sperm kinetic parameters (68.1 ± 5.9% motile sperm) and membrane integrity (48.2 ± 7.4%) was provided by Tris extender supplemented with 10% egg yolk. However, both extenders supplemented with any concentration of egg yolk or Aloe vera presented similar preservation of osmotic response and sperm-binding ability after cryopreservation. In summary, we suggest the use of a Tris extender supplemented of 10% egg yolk for cryopreservation of Spix's yellow-toothed cavy epidydimal sperm.

Case report: Epididymal tuberculosis abscess in patient immunocompetent

Tuberculous epididymitis is caused by Mycobacterium tuberculosis. A 30-year-old patient, with a comorbidity of atrial fibrillation, presented with pain in the left testicular for 1 year. On physical examination revealed a patient febrile at 39 °C with a pain, Scrotal swelling. Laboratory tests, a hyperleukocytosis at 25000/mm3, CRP at 160 mg/l. Scrotal ultrasound showed a Collection of fluid. Surgical exploration found an abscessed cyst at the expense of the epididymis. Due to the risk of epididymis neoplasia, surgery therapy ended up in the course of pharmacotherapy and not after 6 weeks as recommended by the studies.

Bisphenol A exposure increases epididymal susceptibility to infection in mice

Male fertility is linked with several well-orchestrated events including spermatogenesis, epididymal maturation, capacitation, the acrosome reaction, fertilization, and beyond. However, the detrimental effects of bisphenol A (BPA) on sperm maturation compared to spermatogenesis and sperm cells remain unclear. Therefore, this study was to investigate whether pubertal exposure to BPA induces male infertility via interruption of the immune response in the epididymis. CD-1 male mice (5 weeks old) were treated daily with vehicle (corn oil) and 50 mg BPA/kg-BW for 6 weeks by oral gavage. Following BPA exposure, we observed decreased intraepithelial projection of basal cells, indicative of changes to the luminal environment. We also observed decreased projection of macrophages and protrusion of apoptotic cells into the lumen induced by incomplete phagocytosis of apoptotic cells in the caput epididymis. Exposure to BPA also reduced the anti- and pro-inflammatory cytokines IL-10, IL-6, IFN-γ, and IL-7 in the epididymis, while the chemotaxis-associated cytokines CCL12, CCL17, CXCL16, and MCP-1 increased. This study suggests two possible mechanisms for BPA induction of male infertility. First, exposure to BPA may induce an imbalance of immune homeostasis by disrupting the ability of basal cells to perceive environmental changes. Second, exposure to BPA may lead to collapse of macrophage phagocytosis via downregulation of intraepithelial projection and inflammatory-related cytokines. In conclusion, the observed potential pathways can lead to autoimmune disorders such epididymitis and orchitis.

Krukenberg tumor with concomitant ipsilateral hydronephrosis and spermatic cord metastasis in a man: A case report

BACKGROUND

Tumors of the spermatic cord are rare, and approximately 25% are malignant neoplasms. Metastatic spermatic cord tumors are even rarer. Several studies have revealed that the most frequent primary tumors metastasizing to the spermatic cord and peritesticular tissues are neoplasms of the stomach and prostate. Furthermore, metastasis to the spermatic cord or epididymis may occur via retrograde lymphatic and hematic routes. We present the case of a man with gastric cancer that metastasized to the spermatic cord and epididymis, with concomitant ipsilateral hydronephrosis after surgical resection and chemotherapy for his primary tumor.

CASE SUMMARY

A 71-year-old man underwent total gastrectomy for pT4aN2 poorly differentiated gastric adenocarcinoma in December 2016. Two months after surgery, he received adjuvant chemotherapy with TS-1 from February 2017 to February 2018. Surveillance computed tomography (CT) was performed in June 2018, which did not reveal any sign of tumor recurrence. In November 2019, he presented with left lower quadrant abdominal pain and a palpable left inguinal-scrotal mass. CT revealed left mild hydronephrosis and a left scrotal mass measuring 4.0 cm × 1.7 cm. Tumor biomarkers, including alpha-fetoprotein (AFP), lactate dehydrogenase (LDH), beta-human chorionic gonadotropin (βHCG), carcinoembryonic antigen (CEA), and carbohydrate antigen 19-9 (CA19-9) were all normal. Renal and testicular echography showed left hydronephrosis and a left peritesticular soft tissue lesion with blood flow. Diagnostic ureteroscopy showed left lower ureter narrowing without an intraluminal lesion. A biopsy was obtained for the indurated spermatic cord and epididymis, which showed poorly differentiated adenocarcinoma. Immunohistochemical staining demonstrated that the tumor was diffusely and strongly positive for homeobox protein CDX2. The features were consistent with metastatic adenocarcinoma of a primary gastric tumor.

CONCLUSION

In patients with a history of primary cancer, an inguinal mass of unknown cause with accompanying ipsilateral hydronephrosis may be a sign of distant metastasis from a primary tumor, especially of gastrointestinal origin.

Oxytocin receptor expression in stallion testes and epididymides

Endocrine, paracrine, and autocrine factors orchestrate the development and physiology of the stallion reproductive system. Oxytocin (OXT) is one of the critical endocrine, paracrine, and autocrine factors for the male reproductive system. Previous studies have investigated OXT receptor (OXTR) expression in testes and epididymides, including humans, marmosets, macaques, swine, and sheep. This study aimed to explore (1) OXTR localization in the testes and epididymides and (2) the seasonal modification of OXTR expression in the testes. Adult stallion testis and epididymis samples were prepared using routine castration procedures. Reverse-transcription PCR was performed to detect the presence of OXTR messenger RNA (mRNA) in the testes. Western blot procedure was performed to confirm the cross-reactivity of OXTR antibody to horse OXTR. Immunohistochemistry was performed to detect OXTR protein expression in the testes and epididymides. Oxytocin receptor mRNA was detected in the stallion testes. The OXTR protein band was observed at 55 kDa. Interestingly, the relative intensity of the OXTR protein band varied between nonbreeding and breeding season. The OXTR protein level in the testes collected during the breeding season was higher than that during the nonbreeding season. Oxytocin receptor localization was observed in the cytoplasm of Type A spermatogonia and spermatid. Oxytocin receptor protein expression was also observed in the cytoplasmic area of Leydig cells and the membrane of the seminiferous tubules. The cytoplasm of principal and basal cells in the caput, corpus, and cauda was also immunolabeled with OXTR antibody. In conclusion, based on the expression of OXTR in tissues of testes and epididymides, OXT-OXTR system may be a critical factor for stallion testicular and epididymal function. In addition, according to the seasonal alteration of intensity, the OXT-OXTR system may be associated with seasonal changes in the reproductive system in stallions.

Expression and localization of alpha-tubulin N-acetyltransferase 1 in the reproductive system of male mice

The structure of microtubules is essential for the fertilizing ability of spermatozoa. Acetylation of α-tubulin plays an important role in flagellar elongation and spermatozoa motility. Previous reports have suggested that alpha-tubulin N-acetyltransferase 1 (ATAT1) is the main acetyltransferase involved in the acetylation of α-tubulin. Although ATAT1 is reported to express in the testis, no information is available regarding its expression in elongated spermatids, epididymis, and mature spermatozoa. Hence, it remains unclear whether ATAT1 is involved in spermatozoa maturation and capacitation. Therefore, we evaluated the expression of ATAT1 in the mouse male reproductive system using immunostaining and western blotting. Our results showed that ATAT1 was expressed in spermatids during spermiogenesis in mouse testes, but its expression varied according to the seminiferous tubule stage. We observed ATAT1 in the cytoplasm of round spermatids, the flagella of elongated spermatids, and in the cytoplasm of step 16 spermatids, just before its release into the lumen. In addition, ATAT1 was expressed in epithelial cells of the epididymis. In spermatozoa of the cauda epididymis, ATAT1 expression was primarily observed in the midpiece of the spermatozoa. The localization of ATAT1 protein in the male germline was observed during spermiogenesis as well as during spermatozoa maturation. Our results suggest that ATAT1 may be involved in the formation of flagella and in the acetylation process, which has attracted attention in recent years regarding male infertility.

Proxeed plus salvage rat testis from ischemia- reperfused injury by enhancing antioxidant's activities and inhibition of iNOS expression

Testicular torsion is an acute urological emergency condition that occurs due to obstruction of blood flow to the testicles which may result in ischemia and loss of testicular functions. This study examined the protective effects of Proxeed Plus (PP), a dietary supplement on testicular ischemia/reperfusion (I/R) injured rats using oxidative stress markers, hormonal levels, apoptotic parameters, histological and immunohistochemistry analysis at 4 h and after 7 days of reperfusion. The protective treatment of the I/R injured rats with PP at 1000 and 5000 mg/kg body weight (bw) resulted in significant increases in the serum and tissue antioxidative defense capacities (superoxide dismutase, reduced glutathione, catalase, glutathione-s-transferase, and glutathione peroxidase), sex hormones (luteinizing hormone, follicle-stimulating hormone, and testosterone), also reduce pro-oxidative markers (malondialdehyde and hydrogen peroxide), serum iNOS and apoptotic parameters (Caspase -3 and Caspase -9) in comparison to the results detected in the I/R untreated rats. It was also observed that PP ameliorated histological changes of I/R injured rats; increased spermatogenetic activity, seminiferous tubular diameter, Leydig cell mass, and reduced expressions of testicular inducible nitric oxide synthase (iNOS). Therefore, the therapeutic use of Proxeed Plus could be considered a promising approach in averting testicular damage against I/R injury.

Sperm head morphometry and chromatin condensation are in constant change at seminiferous tubules, epididymis, and ductus deferens in bulls

The aim of this study was to evaluate the sperm head morphometry and chromatin condensation at different regions of the reproductive tract in bulls. Sperm smears of seminiferous tubules (ST), epididymis head (EH), body (EB), and tail (ET), and ductus deferens (DD) were stained with toluidine blue. Afterwards, the sperm head morphometry and chromatin alteration types were evaluated by a computational image analysis. Overall, spermatozoa of ST had lower (P < 0.05) area (A), perimeter (P), width (W), length (L), ellipticity (E), and Fourier harmonics (F0, F1, and F2). The chromatin decondensation (CD) and heterogeneity (CH) were higher (P < 0.05) in the ST region and decreased (P < 0.0001) during the migration along the reproductive tract (ST - DD direction). Considering the factors extracted (Factors 1 and 2) by the principal component analysis, the parameters A, P, W, L, and F0 were responsible for ∼36% of the Factor 1, while the E, F0, F1, and anterior-posterior symmetry (APS) contributed ∼27% to Factor 2. Both, CD and CH were associated with Factor 1 in the EH and ET regions and Factor 2 in the ST. Also, a well-defined difference between sperm heads collected from the ST and DD regions was observed by canonical analysis. The distribution of each chromatin alteration type was recorded. The proportion of normal sperm was lower (P < 0.05) in ST compared to other regions. Moreover, the chromatin influenced the morphometry and sperm heads with whole chromatin alteration type showed a smaller (P < 0.05) A, P, W, L, and E. In summary, the epididymal maturation is important for chromatin compaction and final morphometry of the sperm head. Also, the identification and quantification of the sperm chromatin condensation in different regions of reproductive tract can be used as potential biomarkers to predict the fertility in bulls.

Passage of spermatozoa through the epididymis of the boar (Sus scrofa domesticus)

Previous studies of epididymal transit in the pig have had insufficient animal numbers to provide a comprehensive picture of a continuous process. The present study attempts to addresses this issue. Radioactively labeled thymidine was infused into the testicular arteries of 48 sexually rested young adult boars of the Goettingen Miniature Pig breed. Hemicastrations were performed in random order in 2 animals daily on Days 21-24 following thymidine injection and in 4 animals daily on Days 25-41 and 43, 45, 47 and 49. Sperm obtained from 12 epididymal sites between the proximal caput and distal cauda were autoradiographically examined to record the percentage of labeled sperm and labeling intensity at different times after thymidine infusion. An initial surge of labeled spermatozoa emerged in the proximal caput 28 days after thymidine injection. After 2 d labeled sperm had arrived at the distal caput and, after another 2, the bulk of labeled sperm was found in the corpus. From there the sperm advanced to the transition of corpus and cauda, where progress was arrested until Day11. On Day 12, transit was resumed and by Day 13 sperm had passed through the cauda and vacated the epididymis via the ductus deferens.

Radioprotective Effects of Zinc and Selenium on Mice Spermatogenesis

Background

Spermatogenesis system is one of the most radiosensitive organs in the body. A usual therapeutic dose of radiation such as the conventional 2 Gy in each fraction of radiotherapy and lower doses seen in diagnostic radiology or a radiation disaster affect the process of spermatogenesis potently. Selenium and zinc are two important elements playing key roles in the development of sperms and also have radioprotective effects.

Objective

In this study aims to evaluate the radioprotective effect of zinc and selenium against radiation-induced mice testis injury.

Material and Methods

In this experimental study, 30 mice were divided equally into 6 groups, including control selenium treated, zinc treated, radiation, radiation + selenium, radiation + zinc. Treatments started from 2 days before irradiation with 2 Gy cobalt-60 gamma rays. After 37 days, all mice were killed for histopathological evaluations.

Results

Results showed that exposure to radiation caused a potent effect on spermatogenesis system. Treatment with selenium reversed these radiation effects potently, while zinc had some limited protective effects. Zinc treatment itself caused a detrimental effect on epididymis and, in combination with radiation, it leads to more damage to seminiferous tubules.

Conclusion

In contrast to previous studies that proposed zinc to protect spermatogenesis against various toxic agents, results of this study showed that although zinc may protect from some parameters, it potentiates radiation damage on seminiferous tubules and has a detrimental effect on the epididymis. By contrast, zinc and selenium could alleviate radiation-induced toxicity on the most of the evaluated parameters.

Changes in miRNA levels of sperm and small extracellular vesicles of seminal plasma are associated with transient scrotal heat stress in bulls

Scrotal heat stress affects spermatogenesis and impairs male fertility by increasing sperm morphological abnormalities, oxidative stress and DNA fragmentation. While sperm morpho-functional changes triggered by scrotal heat stress are well described, sperm molecular alterations remain unknown. Recently, spermatozoa were described as accumulating miRNAs during the last steps of spermatogenesis and through epididymis transit, mainly by communication with small extracellular vesicles (sEVs). Herein, the aim was to investigate the impact of scrotal heat stress in miRNAs profile of sperm, as well as, seminal plasma sEVs. Six Nelore bulls (Bos indicus) were divided into two groups: Control (CON; n = 3) and Scrotal Heat Stress (SHS; n = 3; scrotal heat stressed during 96 h by scrotal bags). The day that the scrotal bags were removed from SHS group was considered as D0 (Day zero). Seminal plasma sEVs were isolated from semen samples collected seven days after heat stress (D+7) to evaluate sEVs diameter, concentration, and 380 miRNA levels. Sperm morpho-functional features and profile of 380 miRNAs were evaluated from semen collected 21 days after heat stress (D+21). As a control, sEVs and sperm were analyzed seven days before heat stress (D-7). Only semen parameters that were not significantly different (P > 0.05) among bulls on D-7 were addressed on D+7 and D+21. While no alterations in diameter and concentration were detected in sEVs on D+7 between CON and SHS groups, three sEVs-miRNAs (miR-23b-5p, -489 and -1248) were down-regulated in SHS bulls compared to CON on D+7; other three (miR-126-5p, -656 and -1307) displayed a tendency (0.05 < P < 0.10) to be altered. Sperm oxidative stress was higher, and the level of 21 sperm miRNAs was altered (18 down-, 3 up-regulated) in SHS bulls compared to CON on D+21. Functional analysis indicated that target genes involved in transcription activation, as well as cell proliferation and differentiation were related to the 18 down-regulated sperm miRNAs (miR-9-5p, -15a, -18a, -20b, -30a-5p, -30b-5p, -30d, -30e-5p -34b, -34c, -106b, -126-5p, -146a, -191, -192, -200b, -335 and -449a). Thus, the scrotal heat stress probably impacted testicular and epididymis functions by reducing the levels of a substantial proportion of sEVs and sperm miRNAs. Our findings suggest that miR-126-5p was possibly trafficked between sEVs and sperm and provide new insights on the mechanism by which sperm acquire miRNAs in the last stages of spermatogenesis and sperm maturation in cattle.

Analysis of long non-coding RNAs in epididymis of cattleyak associated with male infertility

Cattleyak (CY), is a cross breed between cattle and yak (YK), which display equal adaptability to the harsh environment as YK and much higher performances than YK. However, the CY is female fertile and male sterile. Previous studies were conducted on testes tissues to investigate the mechanism of male infertility in CY. There is no systematic research on genes, especially lncRNAs between CY and YK epididymis. In this study, Illumina Hiseq was performed to profile the epididymis transcriptome (lncRNA and mRNA) of CY and YK. In total 18859 lncRNAs were identified, from which lincRNAs 12458, antisense lncRNAs 2345, intronic lncRNAs 3101, and sense lncRNAs 955 respectively. We have identified 345 DE lncRNAs and 3008 DE mRNAs between YK and CY epididymis. Thirteen DEGs were validated by quantitative real-time PCR. Combing with DEG, 14 couples of lncRNAs and their target genes were both DE, and 6 of them including CCDC39, KCNJ16, NECTIN2, MRPL20, PSMC4, and DEFB112 show their potential infertility-related terms such as cellular motility, sperm maturation, sperm storage, cellular junction, folate metabolism, and capacitation. On the other hand, several down-regulated genes such as DEFB124, DEFB126, DEFB125, DEFB127, DEFB129, CES5A, TKDP1, CST3, RNASE9 and CD52 in CY compared to YK were involved in the immune response and sperm maturation. Therefore, comprehensive analysis for lncRNAs and their target genes may enhance our understanding of the molecular mechanisms underlying the process of sperm maturation in CY and may provide important resources for further research.

Molecular insights into the divergence and diversity of post-testicular maturation strategies

Competition to achieve paternity has coerced the development of a multitude of male reproductive strategies. In one of the most well-studied examples, the spermatozoa of all mammalian species must undergo a series of physiological changes as they transit the male (epididymal maturation) and female (capacitation) reproductive tracts prior to realizing their potential to fertilize an ovum. However, the origin and adaptive advantage afforded by these intricate processes of post-testicular sperm maturation remain to be fully elucidated. Here, we review literature pertaining to the nature and the physiological role of epididymal maturation and subsequent capacitation in comparative vertebrate taxa including representative species from the avian, reptilian, and mammalian lineages. Such insights are discussed in terms of the framework they provide for helping to understand the evolutionary significance of post-testicular sperm maturation.