The male reproductive cycle of the brown basilisk Basiliscus vittatus (Squamata: Corytophanidae) from Tabasco, Southern Mexico

We used histological and morphometric methods to study the testis and associated glands, including the epididymis, ductus deferens, and renal sexual segment (RSS), of specimens of Basiliscus vittatus sampled from Tabasco, Mexico (17.5926° N, 92.5816° W). Samples were collected throughout 1 year, which included the dry (February to May) and rainy (June to January) seasons. Spermatogenesis in B. vittatus is active throughout the year, but a significant increase in the testicular volume, diameters of seminiferous tubules, height of the germinal epithelium, spermiogenesis, and released spermatozoa occur in the dry season. During the rainy season, all aforementioned parameters decreased except the secretory activity of the epididymis and the RSS, which increased concomitant with an increase of the spermatozoa population within the ductus deferens. These data strongly suggest that B. vittatus reproduce year-round, but males exhibit a peak in spermatogenic activity during the dry season and a peak in insemination and/or copulation at the beginning of the rainy season. We highlight the importance of analyzing not only the testis but also accessory ducts and glands when determining the reproductive cycles of reptiles. The reproductive cycle of B. vittatus is discussed in relation to the environmental conditions of Southern Mexico and is compared to that of other squamates.

Immunolocalization of apelin receptor (APJ) in mouse seminiferous epithelium

The apelin receptor (APJ) belongs to the member of the G protein-coupled receptor family, and expression of APJ has been reported in the different cell types of testis. The seminiferous tubules in the testis can be identified as different stages (I-XII). It has been also suggested that different factors could be expressed in stage and cell-specific manner in the seminiferous tubules. Recently, we also shown that expression of APJ is developmentally regulated in the testis from PND1 to PND42. Therefore, we analyzed the expression of APJ in the testis of adult mice by immunohistochemistry. Immunohistochemistry showed that the APJ was highly specific for the round and elongated spermatids with stage-dependent changes. The seminiferous tubules at stages I-VII showed APJ immunostaining in the spermatid steps 1-8, not steps of 13-16. The seminiferous tubules at stages IX-XII showed APJ immunostaining in the spermatid steps 9-12. These results suggested the possible role of APJ in the spermiogenesis process. The intratesticular administration of APJ antagonist, ML221 showed a few round spermatids in the seminiferous tubules and some of the tubules with complete absence of round spermatid. Overall, we present evidence that APJ expression in spermatid is dependent on the stages of the seminiferous epithelium cycle and APJ could be involved in the differentiation of round spermatid to elongated spermatid.

Expression pattern of germ cell markers in cryptorchid stallion testes

Cryptorchidism affects spermatogenesis and testis development, often resulting in stallion subfertility/infertility. This study aims to identify the specific germ cells impacted by cryptorchism in stallions. In a previous study, we found that PGP9.5 and VASA are molecular markers expressed in different germ cells within stallions. Herein, we assessed the heat stress-induced response of spermatogonial stem cells (SSCs) in the seminiferous tubules (ST) of cryptorchid stallion testes (CST) and normal stallion testes (NST). This goal was accomplished by comparing PGP9.5 and VASA expression patterns through reverse transcription quantitative PCR and immunofluorescence assays. We also compared the cross-sectional ST area between groups. Six post-pubertal Thoroughbred unilateral cryptorchid stallions were used. The relative abundance of the mRNA transcripts of PGP9.5 and VASA was significantly upregulated in the NST group than in the CST group. Additionally, the cross-sectional ST area and localization of PGP9.5 and VASA in germ cells were significantly higher in the NST group than in the CST group. Regarding Leydig cells, PGP9.5 staining was observed in both groups. Spermatogonia, primary spermatocytes and secondary spermatocytes were immunostained with VASA in the NST group, while immunostaining was only observed in spermatogonia in the CST group. These results indicate long-term exposure to heat stress conditions, such as cryptorchidism, directly impacts germ cell proliferation and differentiation, leading to impaired spermatogenesis and compromised fertility in stallions.

Protective role of hesperidin in finasteride-induced testicular toxicity in adult male Wistar rats: Insights into oxidative stress, apoptosis, and ultrastructure of seminiferous tubules

A negative impact of finasteride on fertility has been reported, in which over production of reactive oxygen species and apoptosis were implicated. Hesperidin, a plant-derived bioflavonoid with antioxidant and anti-apoptotic effects, may mitigate these adverse effects. In order to investigate the possible protective role of hesperidin against finasteride-induced seminiferous tubules toxicity in adult male Wistar rats, 60 rats were randomized into five groups (I-V) receiving distilled water, 0.5% sodium carboxymethylcellulose solution, hesperidin, finasteride, and combined hesperidin and finasteride respectively. Testicular weight, sperm count and motility were determined. Testicular tissue homogenates were prepared to measure the level of malondialdehyde (MDA), total antioxidant capacity (TAC), reduced glutathione (GSH) and the gene expression of caspase-3 and B-cell lymphoma 2 (Bcl2). Testes were processed for light and electron microscopic evaluation. Johnsen score was calculated. Administration of finasteride resulted in significantly decreased testicular weights, sperm count and motility, Johnsen score, tissue levels of TAC and GSH together with significant increase in tissue MDA. Gene expression revealed significantly increased caspase-3 and decreased Bcl2. Furthermore, finasteride disrupted the seminiferous tubules, causing degenerative changes affecting Sertoli cells and spermatogenic cells. Co-administration of hesperidin with finasteride resulted in improvement in testicular weights, TAC, GSH, Bcl2, Johnsen score, sperm count and motility as well as preservation of the structure of the seminiferous tubules. To conclude, hesperidin was found to have a protective potential on finasteride-induced oxidative stress, apoptosis and testicular structural damage.

Ultrastructural study: in vitro and in vivo differentiation of mice spermatogonial stem cells

Mouse testicular tissue is composed of seminiferous tubules and interstitial tissue. Mammalian spermatogenesis is divided into three stages: spermatocytogenesis (mitotic divisions) in which spermatogonial stem cells (SSCs) turn into spermatocytes, followed by two consecutive meiotic divisions in which spermatocytes form spermatids. Spermatids differentiate into spermatozoa during spermiogenesis. Various factors affect the process of spermatogenesis and the organization of cells in the testis. Any disorder in different stages of spermatogenesis will have negative effects on male fertility. The aim of the current study was to compare the in vitro and in vivo spermatogenesis processes before and after transplantation to azoospermic mice using ultrastructural techniques. In this study, mice were irradiated with single doses of 14 Gy 60Co radiation. SSCs isolated from neonatal mice were cultured in vitro for 1 week and were injected into the seminiferous tubule recipient's mice. Testicular cells of neonatal mice were cultured in the four groups on extracellular matrix-based 3D printing scaffolds. The transplanted testes (8 weeks after transplantation) and cultured testicular cells in vitro (after 3 weeks) were then processed for transmission electron microscopy studies. Our study's findings revealed that the morphology and ultrastructure of testicular cells after transplantation and in vitro culture are similar to those of in vivo spermatogenesis, indicating that spermatogenic cell nature is unaltered in vitro.

Polycaprolactone/Testicular Extracellular Matrix/Graphene Oxide-Based Electrospun Tubular Scaffolds for Reproductive Medicine: Biomimetic Architecture of Seminiferous Tubules

Numerous scaffolds are developed in the field of testicular bioengineering. However, effectively replicating the spatial characteristics of native tissue, poses a challenge in maintaining the requisite cellular arrangement essential for spermatogenesis. In order to mimic the structural properties of seminiferous tubules, the objective is to fabricate a biocompatible tubular scaffold. Following the decellularization process of the testicular tissue, validation of cellular remnants' elimination from the specimens is conducted using 4',6-diamidino-2-phenylindole staining, hematoxylin and eosin staining, and DNA content analysis. The presence of extracellular matrix (ECM) components is confirmed through Alcian blue, Orcein, and Masson's trichrome staining techniques. The electrospinning technique is employed to synthesize the scaffolds using polycaprolactone (PCL), extracted ECM, and varying concentrations of graphene oxide (GO) (0.5%, 1%, and 2%). Subsequently, comprehensive evaluations are performed to assess the properties of the synthetic scaffolds. These evaluations encompass Fourier-transform infrared spectroscopy, scanning electron microscopy imaging, scaffold degradation testing, mechanical behavior analysis, methylthiazolyldiphenyl-tetrazolium bromide assay, and in vivo biocompatibility assessment. The PCL/decellularized extracellular matrix with 0.5% GO formulation exhibits superior fiber morphology and enhanced mechanical properties, and outperforms other groups in terms of in vitro biocompatibility. Consequently, these scaffolds present a viable option for implementation in "in vitro spermatogenesis" procedures, holding promise for future sperm production from spermatogonial cells.

Mouse In Vitro Spermatogenesis on 3D Bioprinted Scaffolds

Testes have a complex architecture that is compartmentalized into seminiferous tubules with a diameter of approximatively 200 μm in which the germ cells differentiate, surrounded by a basement membrane and interstitium. 3D bioprinting might be used to recreate the compartmentalized testicular architecture in vitro. Directed by a software program, pneumatic microextrusion printers can deposit 3D layers of hydrogel-encapsulated interstitial cells in a controlled manner by applying pressure. Once macroporous-shaped scaffolds resembling seminiferous tubules have been bioprinted with interstitial cells, the epithelial cell fraction can be seeded in the macropores to resemble the in vivo testicular architecture. Moreover, macropores can serve as a delimitation for all testicular cells to reorganize and improve the supply of nutrients to cells through the 3D constructs.

Histological differences between the central and peripheral areas of the testes of busulfan-administered mice

Busulfan is an anticancer drug known to cause serious damage to seminiferous tubules in the testes and deplete germ cells in human and animal models. The testicular artery is anastomosed with deferential and cremasteric arteries and is divided into capsular arteries, which give rise to the centripetal arteries and then recurrent arteries. The arterial blood in the testicular tissue is supplied by such a consequent system of arterial vessels, in order from the peripheral to the central area. As anticancer drugs are generally distributed throughout the whole body via the bloodstream and the running and distribution of arteries differ among the testicular areas, we hypothesized that the efficacy of busulfan differs in different testicular areas, particularly between the central and peripheral areas. In this study, busulfan was intraperitoneally injected at 40 mg/kg body weight into C57BL/6J male mice. After 28 days, in busulfan-treated mice, the diameters of seminiferous tubules were significantly higher in the central than in the peripheral area of the testes. The seminiferous tubular areas also significantly decreased in the peripheral areas compared with the central areas. The number of germ cells per seminiferous tubule was significantly higher in the central than in the peripheral area. Sertoli cell nuclei were detached into the lumen in the peripheral area. The number of Leydig cells was significantly lower in the peripheral areas. These data suggest that the effects of busulfan differ between the central and peripheral areas of the testis at 4 weeks after busulfan administration.

Three-dimensional morphometry of the testis in dog using design-unbiased stereology

Testis is considered the main organ of the male reproductive system. Dogs are used as a suitable experimental model of testicular diseases in humans. From the veterinary aspect, several disorders have been reported to affect the testis in dogs. Thus, the objective of the present study was to investigate the morphometrical features of the dog testis using design-based stereology. The testes of six male dogs were used. Isotropic, uniform random sections were obtained and processed for light microscopy. Testicular total volume and the fractional volume of the seminiferous tubules, interstitial tissue and germinal epithelium were measured using the Cavalieri's estimator and the point counting system. Germinal epithelial surface area was estimated using test lines, and total length of seminiferous tubules was analysed using the counting frames. The total volume of testis was calculated 13.64 ± 1.94 cm3 . The relative volume fractions of the seminiferous tubules, interstitial tissue and germinal layer expressed as a percentage of total testicular volume were found to be 75.87 ± 6.11%, 23.68 ± 5.15% and 64.15 ± 4.82%, respectively. The surface area of the germinal layer was 915.25 ± 150.48 cm2 . The thickness of germinal layer was estimated to be 96.18 ± 10.72 μm. The total length of seminiferous tubules measured 290.8 ± 35.86 m. No statistical difference in investigated parameters was found between the left and right testes (p > 0.05). Our data might contribute to the male reproductive knowledge, help develop experimental studies in this field and possibly lead to advancement in the diagnosis and treatment of testicular diseases in the dog.

Eif2s3y alleviated LPS-induced damage to mouse testis and maintained spermatogenesis by negatively regulating Adamts5

Eif2s3y (eukaryotic translation initiation factor 2, subunit 3, structural gene Y-linked, Eif2s3y) is an essential gene for spermatogenesis. Early studies have shown that Eif2s3y can promote the proliferation of spermatogonial stem cells (SSCs) and can replace the Y chromosome together with sex-determining region Y (Sry) to transform SSCs into round spermatozoa. We injected lentiviral particles into the seminiferous tubules of mouse testes by sterile surgery surgically to establish overexpressing Eif2s3y testes. And then the mice were intraperitoneally injected with LPS to established the model of testis inflammation. Through RNA sequencing, qRT-PCR analysis, Western blot, co-culture etc., we found that Eif2s3y alleviated LPS-induced damage in mouse testes and maintained spermatogenesis. In testes with Eif2s3y overexpression, the seminiferous tubules were more regularly organized after exposure to LPS compared with the control. Eif2s3y performs its function by negatively regulating Adamts5 (a disintegrin and metalloproteinase containing a thrombospondin-1 motif), an extracellular matrix-degrading enzyme. ADAMTS5 shows a disruptive effect when the testis is exposed to LPS. Overexpression of Eif2s3y inhibited the TLR4/NFκB signaling pathway in the testis in response to LPS. Generally, our research shows that Eif2s3y protects the testis from LPS and maintains spermatogenesis by negatively regulating Adamts5.

Stiffness estimated by strain elastography reflects canine testicular spermatogenesis and histology

Ultrasound elastography was proposed for the evaluation of testicular focal lesions, but no studies verified the agreement between the whole histological architecture of the testis and the stiffness measured by elastography. The present study explored the use of strain elastography in the evaluation of testis with normal or abnormal spermatogenesis, classified based on epididymal sperm attributes, and the consistency between elastographic parameters and the testicular histological feature. Strain elastography was performed during the routine andrological examination in 22 dogs presented for elective orchiectomy. Epididymal sperm attributes and testicular histology were analyzed after orchiectomy. Based on the epididymal sperm characteristics, testes were classified according to normal or abnormal spermatogenesis, and strain elastographic attributes were compared between groups. Possible correlations between strain elastography and histological features were also explored. Consistent with the literature in humans, testes with abnormal spermatogenesis were stiffer (mean strain elastographic index 3.6 ± 0.6) compared with normal testes (mean strain elastographic index 1.9 ± 0.2; P < 0.01). The strain elastographic index was negatively correlated with the area occupied by seminiferous tubules (Pearson's rho = -0.716; P = 0.0003), the mean diameter (Pearson's rho = -0.742; P = 0.0002), and thickness of the seminiferous tubule (Pearson's rho = -0.728; P = 0.0002). Surprisingly, no correlations were found between the area occupied by connective tissue in histological sections and elastographic attributes, suggesting that the increased stiffness was not related to the increased amount of connective tissue. This study demonstrated that strain elastography could be used to support the andrological examination, but measurements should be acquired in specific regions to be reliable.

Isolation of an Insulin-Like Receptor Involved in the Testicular Development of the Mud Crab Scylla paramamosain

Insulin-like androgenic gland hormone (IAG) is a key regulator of male sexual differentiation in crustaceans that plays important roles in secondary sexual characteristics and testicular development. As a hormone, IAG interacts with its membrane receptor to initiate downstream signal pathways to exert its biological functions. In this study, we isolated a full-length cDNA of an insulin-like receptor (Sp-IR) from the mud crab Scylla paramamosain. Sequence analysis revealed that this receptor consists of a Fu domain, two L domains, three FN-III domains, a transmembrane domain, and a tyrosine kinase domain, classifying it as a member of the tyrosine kinase insulin-like receptors family. Our results also suggested that Sp-IR was highly expressed in the testis and AG in males. Its expression in the testis peaked in stage I but significantly decreased in stages II and III (p < 0.01). Next, both short- and long-term RNA interference (RNAi) experiments were performed on males in stage I to explore Sp-IR function in mud crabs. The results showed that Sp-vasa and Sp-Dsx expression levels in the testis were significantly down-regulated after the specific knockdown of Sp-IR by RNAi. Additionally, the long-term knockdown of Sp-IR led to a considerable decrease in the volume of seminiferous tubules, accompanied by large vacuoles and a reduced production of secondary spermatocytes and spermatids. In conclusion, our results indicated that Sp-IR is involved in testicular development and plays a crucial role in transitioning from primary to secondary spermatocytes. This study provided a molecular basis for the subsequent analysis of the mechanism on male sexual differentiation in Brachyuran crabs.

Identification of active spermatogenesis using a multiphoton microscope

BACKGROUND

The sperm retrieval rate of microdissection testicular sperm extraction varies from 25% to 60%. Therefore, it is necessary to establish objective selection criteria for identifying seminiferous tubules with spermatozoa.

OBJECTIVES

Our aim was to develop a method for identifying spermatogenesis without sectioning testicular tissues.

MATERIALS AND METHODS

Testicular tissues of 10-week-old normal rats were fixed with 4% paraformaldehyde. Fluorescent labeling of seminiferous tubule nuclei and F-actin was performed, and the specimens were observed without sectioning using a multiphoton microscope. Cryptorchid rats were used as a model lacking elongated spermatids. Multiphoton images were compared with images of normal seminiferous tubules. In addition, seminiferous tubules of 10-week-old normal rats were labeled by testicular interstitial injection of fluorescent probes and observed by a multiphoton microscope without fixation. Terminal deoxynucleotidyl transferase dUTP nick end labeling-stained images of normal and probe-injected testes were compared.

RESULTS

In fixed seminiferous tubules, elongated spermatids were identified. In addition, F-actin of apical ectoplasmic specialization was observed around elongated spermatids. Furthermore, spermatogenic stages were identified by an array of nuclei or F-actin. In cryptorchid testes, elongated spermatids and F-actin of the apical ectoplasmic specialization were not observed. In testes injected with fluorescent probes, F-actin of the apical ectoplasmic specialization was observed, and spermatogenic stages were identified without fixation. There was no significant difference in the number of terminal deoxynucleotidyl transferase dUTP nick end labeling-positive cells per seminiferous tubule between normal and probe-injected testes.

CONCLUSIONS

Seminiferous epithelium could be observed without sectioning of tissues by fluorescent probes and a multiphoton microscope. Active spermatogenesis was observed by labeling F-actin with and without fixation. Moreover, the toxicity of fluorescent probes was limited. Our method has a potential for live imaging of testicular tissue.

Inactivation of Cops5 in Smooth Muscle Cells Causes Abnormal Reproductive Hormone Homeostasis and Development in Mice

COP9 constitutive photomorphogenic homolog subunit 5 (COPS5), also known as Jab1 or CSN5, has been implicated in a wide variety of cellular and developmental processes. By analyzing male germ cell-specific COPS5-deficient mice, we have demonstrated previously that COPS5 is essential to maintain male germ survival and acrosome biogenesis. To further determine the role of Cops5 in peritubular myoid cells, a smooth muscle lineage surrounding seminiferous tubules, we herein derived mice conditionally deficient for the Cops5 gene in smooth muscle cells using transgenic Myh11-Cre mice. Although these conditional Cops5-deficient mice were born at the expected Mendelian ratio and appeared to be normal within the first week after birth, the homozygous mice started to show growth retardation after 1 week. These mice also exhibited a variety of developmental and reproductive disorders, including failure of development of reproductive organs in both males and females, spermatogenesis defects, and impaired skeletal development and immune functions. Furthermore, conditional Cops5-deficient mice revealed dramatic impairment of the endocrine system associated with testicular functions, including a marked reduction in serum levels of gonadotropins (follicle-stimulating hormone, luteinizing hormone), testosterone, insulin-like growth factor 1, and glucose, but not vasopressin. All homozygous mice died before age 67 days in the study. Collectively, our results provide novel evidence that Cops5 in smooth muscle lineage plays an essential role in postnatal development and reproductive functions.

ARHGEF15 is expressed in undifferentiated spermatogonia but is not required for spermatogenesis in mice

Spermatogenesis is a continual process that relies on the activities of undifferentiated spermatogonia, which contain spermatogonial stem cells (SSCs) that serve as the basis of spermatogenesis. The gene expression pattern and molecular control of fate decisions of undifferentiated spermatogonia are not well understood. Rho guanine nucleotide exchange factor 15 (ARHGEF15, also known as EPHEXIN5) is a guanine nucleotide-exchange factor (GEF) that activates the Rho protein. Here, we reported that ARHGEF15 was expressed in undifferentiated spermatogonia and spermatocytes in mouse testes; however, its deletion did not affect spermatogenesis. Arhgef15-/- mice were fertile, and histological examination of the seminiferous tubules of Arhgef15-/- mice revealed complete spermatogenesis with the presence of all types of spermatogenic cells. Proliferation and differentiation of the undifferentiated spermatogonia were not impacted; however, further analysis showed that Arhgef15 deletion resulted in decreased expression of Nanos2, Lin28a and Ddx4. Together, these findings suggest that ARHGEF15 was specifically enriched in undifferentiated spermatogonia and regulated gene expression but dispensable for spermatogenesis in mice.

Absence of MerTK disrupts spermatogenesis in an age-dependent manner

Spermatogenesis is a highly specialized cell differentiation process regulated by the testicular microenvironment. During the process of spermatogenesis, phagocytosis performs an essential role in male germ cell development, and its dysfunction in the testis can cause reproduction defects. MerTK, as a critical protein of phagocytosis, facilitates the removal of apoptotic substrates from the retina and ovaries through cooperation with several phagocytosis receptors. However, its role in mammalian spermatogenesis remains undefined. Here, we found that 30-week-old MerTK^-/- male mice developed oligoasthenospermia due to abnormal spermatogenesis. These mice showed damaged seminiferous tubule structure, as well as altered spermatogonia proliferation and differentiation. We also found that Sertoli cells from MerTK^-/- mice had decreased phagocytic activity on apoptotic germ cells in vitro. Moreover, a transcriptomic analysis demonstrated that the pivotal genes involved in spermatid differentiation and development changed expression. These results indicate that MerTK is crucial for spermatogenesis, as it regulates the crosstalk between germ cells and Sertoli cells. This provides us insight into the molecular mechanism of MerTK on spermatogenesis and its implications for the diagnosis and treatment of human male infertility.

STAGETOOL, a Novel Automated Approach for Mouse Testis Histological Analysis

Spermatogenesis is a complex differentiation process that takes place in the seminiferous tubules. A specific organization of spermatogenic cells within the seminiferous epithelium enables a synchronous progress of germ cells at certain steps of differentiation on the spermatogenic pathway. This can be observed in testis cross-sections where seminiferous tubules can be classified into distinct stages of constant cellular composition (12 stages in the mouse). For a detailed analysis of spermatogenesis, these stages have to be individually observed from testis cross-sections. However, the recognition of stages requires special training and expertise. Furthermore, the manual scoring is laborious considering the high number of tubule cross-sections that have to be analyzed. To facilitate the analysis of spermatogenesis, we have developed a convolutional deep neural network-based approach named "STAGETOOL." STAGETOOL analyses histological images of 4',6-diamidine-2'-phenylindole dihydrochloride (DAPI)-stained mouse testis cross-sections at ×400 magnification, and very accurately classifies tubule cross-sections into 5 stage classes and cells into 9 categories. STAGETOOL classification accuracy for stage classes of seminiferous tubules of a whole-testis cross-section is 99.1%. For cellular level analysis the F1 score for 9 seminiferous epithelial cell types ranges from 0.80 to 0.98. Furthermore, we show that STAGETOOL can be applied for the analysis of knockout mouse models with spermatogenic defects, as well as for automated profiling of protein expression patterns. STAGETOOL is the first fluorescent labeling-based automated method for mouse testis histological analysis that enables both stage and cell-type recognition. While STAGETOOL qualitatively parallels an experienced human histologist, it outperforms humans time-wise, therefore representing a major advancement in male reproductive biology research.

GATA-1 mutation alters the spermatogonial phase and steroidogenesis in adult mouse testis

GATA-1 is a transcription factor from the GATA family, which features zinc fingers for DNA binding. This protein was initially identified as a crucial regulator of blood cell differentiation, but it is currently known that the Gata-1 gene expression is not limited to this system. Although the testis is also a site of significant GATA-1 expression, its role in testicular cells remains considerably unexplored. In the present study, we evaluated the testicular morphophysiology of adult ΔdblGATA mice with a mutation in the GATA-1 protein. Regarding testicular histology, GATA-1 mutant mice exhibited few changes in the seminiferous tubules, particularly in germ cells. A high proportion of differentiated spermatogonia, an increased number of apoptotic pre-leptotene spermatocytes (Caspase-3-positive), and a high frequency of sperm head defects were observed in ΔdblGATA mice. The main differences were observed in the intertubular compartment, as ΔdblGATA mice showed several morphofunctional changes in Leydig cells. Reduced volume, increased number and down-regulation of steroidogenic enzymes were observed in ΔdblGATA Leydig cells. Moreover, the mutant animal showed lower serum testosterone concentration and high LH levels. These results are consistent with the phenotypic and biometric data of mutant mice, i.e., shorter anogenital index and reduced accessory sexual gland weight. In conclusion, our findings suggest that GATA-1 protein is an important factor for germ cell differentiation as well as for the steroidogenic activity in the testis.

Postpubertal spermatogonial stem cell transplantation restores functional sperm production in rhesus monkeys irradiated before and after puberty

BACKGROUND

Cancer treatment of prepubertal patients impacts future fertility due to the abolition of spermatogonial stem cells (SSCs). In macaques, spermatogenesis could be regenerated by intratesticular transplantation of SSCs, but no studies have involved cytotoxic treatment before puberty and transplantation after puberty, which would be the most likely clinical scenario.

OBJECTIVES

To evaluate donor-derived functional sperm production after SSC transplantation to adult monkeys that had received testicular irradiation during the prepubertal period.

MATERIALS AND METHODS

We obtained prepubertal testis tissue by unilaterally castrating six prepubertal monkeys and 2 weeks later irradiated the remaining testes with 6.9 Gy. However, because spermatogenic recovery was observed, we irradiated them again 14 months later with 7 Gy. Three of the monkeys were treated with GnRH-antagonist (GnRH-ant) for 8 weeks. The cryopreserved testis cells from the castrated testes were then allogeneically transplanted into the intact testes of all monkeys. Tissues were harvested 10 months later for analyses.

RESULTS

In three of the six monkeys, 61%, 38%, and 11% of the epididymal sperm DNA were of the donor genotype. The ability to recover donor-derived sperm production was not enhanced by the GnRH-ant pretreatment. However, the extent of filling seminiferous tubules during the transplantation procedure was correlated with the eventual production of donor spermatozoa. The donor epididymal spermatozoa from the recipient with 61% donor contribution were capable of fertilizing rhesus eggs and forming embryos. Although the transplantation was done into the rete testis, two GnRH-ant-treated monkeys, which did not produce donor-derived epididymal spermatozoa, displayed irregular tubular cords in the interstitium containing testicular spermatozoa derived from the transplanted donor cells.

DISCUSSION AND CONCLUSION

The results further support that sperm production can be restored in non-human primates from tissues cryopreserved prior to prepubertal and post-pubertal gonadotoxic treatment by transplantation of these testicular cells after puberty into seminiferous tubules.

Kaliandra honey improves testosterone levels, diameter and epithelial thickness of seminiferous tubule of white rat (Rattus norvegicus) due to malnutrition through stimulation of HSP70

Background

Malnutrition can cause an increase in oxidative stress as it triggers the expression of heat shock protein70 (HSP70), a chaperon molecule that is needed to repair damaged cells within optimal levels. Honey is a source of feed that can stimulate HSP70 expression, which can be given to the malnourished in the animal trial.

Aim

The purpose of this study was to prove that Kaliandra honey can improve testosterone levels, diameter, and epithelial thickness of the seminiferous tubule of rat testes (Rattus norvegicus) due to malnutrition through stimulation of HSP70, which is expressed immunohistochemically.

Methods

This study used 40 male rats, which were divided into four treatment groups: T0 (negative control): normal rats and not given honey; T1 (positive control): malnourished rats and not given honey; T2 (treatment 2): malnourished rats and given 30% Kaliandra honey (v/v) for 10 days; T3 (treatment 3), malnourished rats and given 50% Kaliandra honey (v/v) for 10 days. The condition of malnutrition is carried out by fasting the feed for five consecutive days resulting in damage to the male reproductive organs, especially the testes.

Results

The results showed that Kaliandra honey at a dose of 50% (v/v) had a significant effect in improving testosterone levels, diameter, and epithelial thickness of seminiferous tubule of malnourished male rats through stimulation of HSP70 expression. The HSP70 expression scores by IHC at T0, T1, T2, and T3 were 0.15a ± 0.5, 3.15c ± 0.4, 2.95c ± 0.35, and 1.75b ± 0.15, sequentially. enzyme-linked immunosorbent assay indirect testosterone levels at T0, T1, T2, and T3 (in μg/dl) were 36.39c ± 0.35, 6.12a ± 0.51, 7.45a ± 0.15, 25.27b ± 0.63, sequentially. The diameter and epithelial thickness of the seminiferous tubule of the testes (in μm) in the four treatments T0, T1, T2, and T3 were 362.40c ± 4.71, 248.46a ± 3.90, 255.22a ± 2.34, 318.37b ± 4.23 and 117.60d ± 11.30, 3.86a ± 1.57, 9.72b ± 3.96, 29.84c ± 4.02 sequentially.

Conclusion

The conclusion of the study showed that Kaliandra honey at a dose of 50% (v/v) had a significant effect in improving testosterone levels, diameter, and epithelial thickness of the seminiferous tubule of malnourished rats through stimulation of HSP70, although not significantly the same as negative control (T0).

Computerized spermatogenesis staging (CSS) of mouse testis sections via quantitative histomorphological analysis

Spermatogenesis in mammals is a cyclic process of spermatogenic cell development in the seminiferous epithelium that can be subdivided into 12 subsequent stages. Histological staging analysis of testis sections, specifically of seminiferous tubule cross-sections, is the only effective method to evaluate the quality of the spermatogenic process and to determine developmental defects leading to infertility. Such staging analysis, however, is tedious and time-consuming, and it may take a long time to become proficient. We now have developed a Computerized Staging system of Spermatogenesis (CSS) for mouse testis sections through learning of an expert with decades of experience in mouse testis staging. The development of the CSS system comprised three major parts: 1) Developing computational image analysis models for mouse testis sections; 2) Automated classification of each seminiferous tubule cross-section into three stage groups: Early Stages (ES: stages I-V), Middle Stages (MS: stages VI-VIII), and Late Stages (LS: stages IV-XII); 3) Automated classification of MS into distinct stages VI, VII-mVIII, and late VIII based on newly developed histomorphological features. A cohort of 40 H&E stained normal mouse testis sections was built according to three modules where 28 cross-sections were leveraged for developing tubule region segmentation, spermatogenic cells types and multi-concentric-layers segmentation models. The rest of 12 testis cross-sections, approximately 2314 tubules whose stages were manually annotated by two expert testis histologists, served as the basis for developing the CSS system. The CSS system's accuracy of mean and standard deviation (MSD) in identifying ES, MS, and LS were 0.93 ± 0.03, 0.94 ± 0.11, and 0.89 ± 0.05 and 0.85 ± 0.12, 0.88 ± 0.07, and 0.96 ± 0.04 for one with 5 years of experience, respectively. The CSS system's accuracy of MSD in identifying stages VI, VII-mVIII, and late VIII are 0.74 ± 0.03, 0.85 ± 0.04, and 0.78 ± 0.06 and 0.34 ± 0.18, 0.78 ± 0.16, and 0.44 ± 0.25 for one with 5 years of experience, respectively. In terms of time it takes to collect these data, it takes on average 3 hours for a histologist and 1.87 hours for the CSS system to finish evaluating an entire testis section (computed with a PC (I7-6800k 4.0 GHzwith 32GB of RAM & 256G SSD) and a Titan 1080Ti GPU). Therefore, the CSS system is more accurate and faster compared to a human histologist in staging, and further optimization and development will not only lead to a complete staging of all 12 stages of mouse spermatogenesis but also could aid in the future diagnosis of human infertility. Moreover, the top-ranking histomorphological features identified by the CSS classifier are consistent with the primary features used by histologists in discriminating stages VI, VII-mVIII, and late VIII.

Resveratrol Ameliorates the Seminiferous Tubules Damages Induced by Finasteride in Adult Male Rats

Finasteride is commonly used in the management of alopecia and nodular prostatic hyperplasia. It was reported to have a harmful effect on spermatogenesis with subsequent infertility. Thus, this research was to determine the ameliorative effect of resveratrol against testicular damage caused by finasteride. Forty adult male rats were randomly divided into four main groups: group I acted as the control, group II was administrated resveratrol 20 mg/kg/day, group III was administrated finasteride 5 mg/kg/day, and group IV was administrated finasteride and resveratrol as in the previous groups. Finasteride induced a significant decrement in the testosterone and dihydrotestosterone levels. The level of malondialdehyde significantly increased, while the levels of glutathione peroxidase, superoxide dismutase, and catalase significantly decreased in the finasteride-administrated rats. Variable histopathological alterations in the testes were revealed in the form of irregular seminiferous tubules. Some seminiferous tubules appeared with degenerated germinal epithelium. Others showed detachment of their germinal epithelium. Congested blood vessels and homogeneous acidophilic substance in-between tubules were also detected. A significant decrement in PCNA positive cells and a significant increment in Bax expression were demonstrated. Ultrastructural examination showed Sertoli cells with rarefied cytoplasm. Vacuolated cytoplasm, shrunken nuclei, and dilated perinuclear spaces were also revealed in the spermatogonia, primary spermatocytes, and early spermatids. On the contrary, few changes were noticed in rats received resveratrol concomitant with finasteride. This study indicated that resveratrol exerted a potent ameliorative effect against testicular injury caused by finasteride.

Cellular evidence of autophagy in Sertoli cells during spermatogenesis in goats

Sertoli cells (SCs) play their nursing role as structural and functional supporting cells during spermatogenesis to ensure the production of highly specialized mature spermatozoa. Besides that, the role of SCs in autophagy during active (adult) and inactive (young) spermatogenesis in the caprine testis is still largely unknown. In this study, we investigated autophagy in goat SCs by light microscopy, immunohistochemistry (IHC), double immunofluorescence (double-IF), and transmission electron microscopy. Light microscopy showed active seminiferous tubules with SCs and layers of developing germ cells in the adult goat testis. In young goats, layer of germ cells and SCs was viewed on the basal membrane in the seminiferous tubule. IHC of autophagy-related 7 (ATG7) showed moderate expressions in the cytoplasmic extensions of SCs during inactive spermatogenesis, and strong expression was observed during active spermatogenesis in the testis of goat. Co-immunolabeling of p62 or light chain 3 (LC3) with vimentin showed increasing expression from the basal to the luminal compartment of the seminiferous tubule and stronger expression during active than inactive spermatogenesis in the testis of goat. Ultrastructure assessment of the cytoplasm in SCs showed phagophores, generated from the endoplasmic reticulum during active spermatocytogenesis. Numerous autophagosomes and autolysosomes were noted in the SCs cytoplasm, which surrounds the spermatogenic cells in the basal compartment of the seminiferous tubules. At a later stage, SCs showed autophagosomes and autolysosomes, together with multivesicular bodies (MVB), during spermiogenesis at different phases of the acrosome formation. Numerous embedded elongated spermatozoa were found in the cytoplasm of SCs, surrounded by autophagic components and MVB. Under TEM, the mean diameter of autophagosomes was 952.35 nm and that of autolysosomes was 504.38 nm. Collectively, these results suggest that autophagy is active in SCs during caprine spermatogenesis and that the level of autophagy becomes more evident as spermatogenesis advances from the basal to the luminal compartment of SC.

Paternal cadmium exposure increases the susceptibility to diet-induced testicular injury and spermatogenic disorders in mouse offspring

The impairments of gestational cadmium (Cd) exposure on testicular development and male fertility in offspring have been reported. Here, we investigated the effect of paternal low-concentration cadmium exposure on testicular development and spermatogenesis in offspring. Five-week-old male mice were exposed to cadmium chloride (100 mg/L) in drinking water for 20 weeks. Results presented that Cd did not affect the testicular histology and sperm count in mice. After mating with untreated females, pregnant mice and pups were then evaluated. No significant difference in the rate for successful pregnancy and the body weight of pups was observed in Cd-exposed mice compared to the controls. Male offspring were given with a chow and high-fat diet from postnatal day (PND) 35 to PND70. Our data indicated that high-fat diet obviously decreased No. of sperm in epididymides of adult offspring due to paternal Cd exposure. Testicular histology revealed that the percentage of seminiferous tubules in stages IX-XII and the atypical residual bodies positive tubules in CdH (paternal cadmium exposure and pubertal high-fat diet) group were higher than these in CdC (paternal cadmium exposure and pubertal chow diet) group. Further analysis demonstrated that high-fat diet markedly accelerated testicular apoptosis, as determined by TUNEL assay and immunostaining for cleaved caspase-3, in male offspring due to paternal Cd exposure. Collectively, high-fat diet exacerbates the damage of testicular development and spermatogenesis in offspring due to paternal cadmium exposure.

[Zinc deficiency induces exfoliation of round spermatids by decreasing the expressions of TGF-β1 and FAK in the mouse testis]

OBJECTIVE

To investigate the mechanisms of zinc deficiency inducing spermatogenic disorders.

METHODS

Forty 4-week-old CD-1 male mice were randomly divided into two groups of equal number: experimental and control, the former fed on a low-zinc diet and the latter on a normal diet, both for 5 weeks. Then all the mice were sacrificed and their testes and epididymides harvested for detection of the concentration of zinc ion in the testis by atomic absorption spectrophotometry, observation of the histopathological changes in the testis and epididymis by HE staining, examination of the properties of the exfoliated cells by dual immunofluorescence staining and determination of the expressions of ZO-1, FAK, TGF-β1, TGF-β2, TNF-α and Par6 proteins in the testicular tissue by Western blot.

RESULTS

The concentration of zinc ion in the testis was significantly lower in the experimental than in the control group (［140.59 ± 16.22］ vs ［218.44 ± 31.29］ μg/g, P < 0.05). HE staining showed normal testicular tissue structure, dense seminiferous tubules and intact seminiferous epithelium, with clear and orderly arrangement of spermatogenic cells at all levels in the control group. The ratio of the abnormal seminiferous tubules to the total number was 0.01 ± 0.01. The mice in the experimental group, however, exhibited degeneration of seminiferous epithelium, reduced number of spermatids, vacuolated cytoplasm of Sertoli cells, occluded seminiferous tubules, and a remarkably larger number of abnormal seminiferous tubules than that in the control (0.75 ± 0.04 vs 0.25 ± 0.04, P < 0.01). Exfoliated cells were observed in the abnormal tubules and the caput, corpus and cauda of the epididymis in the experimental group, which were shown to be immature round spermatids in H1T2 and TRA54 dual-immunofluore-scence staining. Western blot manifested that the protein expression of ZO-1 was 0.904 ± 0.052 vs 1.130 ± 0.054 in the experimental and control groups, that of Par6 was 0.129 ± 0.049 vs 0.145 ± 0.047, that of TGF-β2 was 0.116 ± 0.047 vs 0.142 ± 0.048, and that of TNF-α was 0.469 ± 0.022 vs 0.458 ± 0.023, with significant decreases in the former group as compared with the latter in the levels of FAK (0.144 ± 0.047 vs 0.219 ± 0.048, P < 0.05) and TGF-β1 (0.024 ± 0.058 vs 0.586 ± 0.048, P < 0.01).

CONCLUSIONS

Zinc deficiency can induce histopathological changes in the testis of the mouse, leading to exfoliation of round spermatids, in which FAK and TGF-β1 may play an essential contributive role.

[Spatio-temporal expression and function of KIFC1 in acrosomogenesis]

OBJECTIVE

To investigate the spatio-temporal expression and function of the end-directed KIFC1 (kinesin family member C1) protein during acrosomogenesis.

METHODS

The expression and location of KIFC1 were analyzed by flow separation and immunofluorescence, and the small interference RNA (RNAi1) of KIFC1 with high-interference efficiency was screened using in vitro GC2-spd cell lines. The KIFC1 RNAi1 mixed with 0.5% trypan blue solution was microinjected into the testicular seminiferous tubules and negative Con-RNAi1 into the contralateral testis of a 3-week-old Balb/c mouse, followed by morphological analysis of the sperm collected from the testis tail at 3 weeks after injection.

RESULTS

The expression of KIFC1 was observed mainly in the cytoplasm of the sperm cells in the early stage of sperm deformation, in the acrosomal vesicle and acrosome in the middle stage, and in the residual body in the late stage, but vanished during sperm maturation. The sperm head deformity rate was significantly higher in the RNAi1 than in the negative control group (［32.12 ± 0.25］% vs ［7.06 ± 1.25］%, P < 0.01).

CONCLUSIONS

The KIFC1 protein may play an important role in the formation of spermatozoa, mainly affecting acrosomogenesis.

[Establishment of a method for in vitro culture of fetal rat testis tissue]

OBJECTIVE

To establish a method for in vitro culture of the fetal rat testis tissue.

METHODS

Nine sexually mature specific-pathogen-free rats, 3 males and 6 females, weighing 200－250 g, were used for this study. The estrus of the female rats was determined according to the results of the vaginal smear test. The female rats were mated with the male ones in proestrus and estrus at night in the ratio of 2∶1 and observed the following day for conception (0.5 day post-conception ［dpc］) based on the presence of sperm in the vaginal smear. At 15.5 dpc, the fetal testes were isolated under the anatomical microscope, some for HE staining and the rest divided into a control and an hCG group to be cultured in a soft agar culture system at 37 ℃ in a humidified atmosphere containing 5% CO2. From the first day of culture (d 0), the development of the testes was observed under the inverted microscope, the culture medium collected and replaced on d 1, d 2, d 3 and d 4, and the testis tissue obtained on d 4. The concentration of testosterone in the culture medium was determined and the testis tissues were fixed, dehydrated and embedded for histological examination.

RESULTS

Fetal rats were successfully obtained with the vaginal smear at 15.5 dpc, and the fetal testes effectively isolated, which were well developed, with gradual increase of their volume and enlargement of convoluted seminiferous tubules under the inverted microscope. Testosterone was observed in the culture medium, its concentration gradually increasing and reaching the peak on d 3, and its secretion stimulated by hCG. At 15.5 dpc. The fetal testes showed a histomorphological integrity, with typical seminiferous tubules, gonocytes, Sertoli cells and Leydig cells, but no central necrosis. Transmission electron microscopy revealed gonocytes and Sertoli cells within and Leydig cells between the seminiferous tubules, without obvious swelling of the mitochondria and endoplasmic reticula in the cells.

CONCLUSIONS

The fetal rat testis tissue cultured in the soft agar culture system can develop well, retain its normal activity, and excrete testosterone into the culture medium.

Fluoride exposure changed the structure and the expressions of HSP related genes in testes of pubertal rats

Previous studies have indicated that fluoride exposure damaged the male reproductive function; however, the cellular mechanism of fluoride-induced testicular toxicity is still unclear. In this study, twenty-two female pregnant Wistar rats were allotted randomly to two groups: control (deionized water) and sodium fluoride (NaF, contain F^-: 67.86 mg/L) groups. After delivery, the dosage was continued for 15 weeks for puppies. Twelve rats in each group were tested at 6 and 9 (pubertal); 12 and 15 (mature) weeks of age. Our results suggested that organ coefficient of epididymis was significantly decreased in the mature (12 and 15 week-old) rats. Epididymal sperm abnormality and femur fluoride concentration were increased with the concomitant decrease in sperm motility and concentration in these experimental periods. Compared to the control, in the NaF group, the seminiferous tubules of each age were reduced in terms of diameter and thickness. The sperm cells were lost and shedding and finally disappeared after 9 weeks. mRNA and protein levels of HSP27 and 90 were decreased with a concomitant increase in HSP70 and HSF mRNA and protein levels in NaF exposed rats. The mRNA and protein levels of HSP27 and HSF (only mRNA) were significantly increased in NaF treated rats at 9 and 15 weeks of age, respectively. In summary, these results emphasize that NaF induces testicular and sperm abnormalities through the involvement of HSPs especially during the pubertal period.

[Protective effect of Qilin Pills on the reproductive function of oligoasthenospermia rats]

OBJECTIVE

To study the protective effect of Qilin Pills (QLP) on the reproductive function of rats with oligoasthenospermia (OAS) induced by tripterygium glycosides.

METHODS

Twenty-eight male SD rats were randomly divided into a normal control, an OAS model control, a low-dose QLP, and a high-dose QLP group of equal number. OAS models were made in the latter three groups by intragastrical administration of tripterygium glycosides at 40 mg per kg of the body weight per day, and meanwhile the animals in the low- and high-dose QLP groups were treated with QLP at 1.62 and 3.24 g per kg of the body weight per day, respectively, while those in the OAS model group with normal saline, all for 30 consecutive days. Then all the rats were executed for obtaining the testis weight, testis viscera index, epididymal sperm concentration and motility, reproductive hormone levels, and antioxidation indexes and observation of the histomorphological changes of the testis tissue by HE staining.

RESULTS

After 30 days of intervention, the low- and high-dose QLP groups, as compared with the OAS model controls, showed significantly improved epididymal sperm concentration (［14.57 ± 3.95］ and ［39.71 ± 11.31］ vs ［4.71 ± 1.25］ ×10⁶/ml, P <0.05) and motility (［3.71 ± 1.11］ and ［4.29 ± 1.80］ vs ［0.57 ± 0.53］%, P <0.05), increased levels of sex hormone binding globulin (SHBG) (［94.83 ± 11.17］ and ［88.05 ± 9.21］ vs ［56.74 ± 8.29］ nmol/L, P <0.05) and free testosterone (FT) (［27.27 ± 3.63］ and ［32.80 ± 2.51］ vs ［22.81 ± 2.75］ nmol/L, P <0.05), decreased level of follicle-stimulating hormone (FSH) (［1.49 ± 0.62］ and ［1.12 ± 0.83］ vs ［1.71 ± 0.52］ mIU/ml, P <0.05), but no significant change in the total testosterone (TT) level. Meanwhile, the level of superoxide dismutase (SOD) was markedly elevated in the low- and high-dose QLP groups in comparison with the OAS model control group (［277.14 ± 15.84］ and ［299.60 ± 20.83］ vs ［250.04 ± 31.06］ U/ml, P <0.05) while that of reactive oxygen species (ROS) remarkably reduced (［397.61 ± 62.71］ and ［376.84 ± 67.14］ vs ［552.20 ± 58.07］ IU/ml, P <0.05). HE staining showed that QLP intervention significantly increased the layers and quantity of spermatogenic cells in the testicular seminiferous tubules of the OAS rats.

CONCLUSIONS

QLP can effectively protect the reproductive system of oligoasthenospermia rats by raising sperm quality, elevating reproductive hormone levels, reducing oxidative stress injury, and improving histomorphology of the testis.

Preventive role of magnesium sulphate on dexamethasone induced testicular injury in albino rats

OBJECTIVE

To evaluate the protection provided by magnesium sulphate on corticosteroid-induced testicular injury in albino rats.

METHODS

This experimental study was conducted at Jinnah Postgraduate Medical Centre, Karachi, from August 1 to 20, 2012, and comprised albino rats. About 90-120 days old and weighing 200-230 gm. They were divided into 3 groups. Group A comprised controls, Group B animals were administered dexamethasone 4mg/kg body weight per day intra-peritoneally, and Group C animals were given magnesium sulphate 20mg/kg body weight per day intramuscularly, with dexamethasone at same dose as in Group B. Rats were sacrifised at the end of study period after recording their final weight. A midline abdominal incision was made and extended downward to the scrotum. Both testes were removed. Sections from both testes were prepared and stained with periodic acid-Schiff -Iron Haematoxylin.

RESULTS

Of the 30 rats, each group had 10(33.33%). The mean final body weight was 251.80±1.35gm in Group A, 204.60±1.88gm in Group B and 236.00±2.52gm in Group C. The mean diameter of seminiferous tubules was 268.40±7.30mm in Group A, 177.00±10.90mm in Group B and 238.40±2.42mm in Group C. The mean thickness of germinal epithelium was 85.26±1.93mm, 32.40±3.26mm and 60.40±3.18mm in the three groups, respectively.

CONCLUSIONS

The use of dexamethasone caused testicular injury, which ameliorated significantly by the concomitant use of magnesium sulphate.

[Breviscapine protects bilateral testes of prepubertal rats after testicular torsion/detorsion]

OBJECTIVE

To investigate the long-term protective effect of breviscapine on the bilateral testes of prepubertal rats after testicular torsion / detorsion.

METHODS

Thirty-two four-week-old healthy male SD rats were equally randomized into groups A(sham operation),B(normal saline),C(single-dose breviscapine, injected intraperitoneally at 2 mg per kg of the body weight at 30 min before testicular detorsion), and D( continuous-dosing breviscapine, injected intraperitoneally at 2 mg per kg of the body weight at 30 min before testicular detorsion qd for 7 days after surgery). At 6 weeks after establishment of the model of left testicular torsion /detorsion, the rats were sacrificed and the bilateral testes and epididymides harvested for detection of the total antioxidant capacity( TAOC),superoxide dismutase( SOD) level, nitric oxide synthase( NOS) activity, and malondialdehyde( MDA) content in the testis tissue, determination of sperm concentration, viability and motility, and observation of the pathological changes of the testis tissue.

RESULTS

Compared with group B, both groups C and D showed obvious increases in the levels of SOD,T-AOC and NOS and the concentration, survival rate and motility of sperm, but a remarkable decrease in the MDA content, with statistically significant differences(P < 0. 05) except in T-AOC, sperm concentration and motility in the contralateral testis of group C and in NOS activity in the bilateral testes of group D. In comparison with the ipsilateral testis of group C,group D exhibited markedly elevated levels of SOD,T-AOC and NOS, increased sperm concentration, viability and motility, and reduced content of MDA in the bilateral testes, with statistically significant differences( P < 0. 05) except in NOS activity in the contralateral testis. Bilateral seminiferous tubule degeneration and interstitial edema were observed in group B, more severe in the injured than in the contralateral testis. Obvious improvement was seen in the post-torsion / detorsion histological changes of the bilateral testis tissue in groups C and D.

CONCLUSION

Breviscapine can obviously protect the bilateral testes of prepubertal rats after testicular torsion / detorsion by removal of oxygen free radicals and reduction of lipid peroxidation injury, and continuous dosing is even more effective than single-dose medication.

[Long-term exposure to PM2.5 from automobile exhaust results in reproductive dysfunction in male rats]

OBJECTIVE

To explore the effects of long-term exposure to particulate matter 2.5 (PM2.5) from automobile exhaust on the reproductive function of Sprague Dawley (SD) rats.

METHODS

Forty-five male SD rats, weighing 80 - 94 g and aged 28 days, were randomly assigned to receive intra-tracheal administration of 0.9% normal saline (control group, n = 15), PM2. 5 at 2 μg per 100 g body weight per day (low-dose PM2.5 group, n = 15), and PM2.5 at 16 μg per 100 g body weight per day (high-dose PM2.5 group, n = 15), qd, for 60 successive days. After the last 24-hour exposure, 10 rats were taken from each group for copulation with normal female ones, while the others were sacrificed, their testes removed for sperm count and deformity, pathological examination, and determination of the Connexin43 expression.

RESULTS

The conception rate was significantly decreased in the low- and high-dose PM2.5 groups as compared with that of the control (70% and 50% vs 100%), and so were the sperm count and quality. The rats in the PM2.5-exposed groups showed significantly disordered histological structure of the seminiferous tubules, reduced sperm count in the testicular lumen, some exfoliated secondary spermatocytes, downregulated Connexin43 expression in the testis, and damaged blood-testis barrier.

CONCLUSION

Long-term exposure to PM2.5 from automobile exhaust damages the reproductive function of male SD rats.

[Spermatogenesis recovery following allogeneic transplantation of undifferentiated Sertoli cells in experimental model of bilateral abdominal cryptorchidism]

This study explores the effect of transplantation of undifferentiated Sertoli cells in the testicular tissue of an experimental animal model of bilateral abdominal cryptorchidism. Effectiveness of undifferentiated Sertoli cell transplantation was assessed after 1 and 3 months after injection. Partial restoration of seminiferous tubules was found to occur after transplantation. In a third of them germ cells of all stages of the differentiation were discovered while they were not found in the control group.

[Expression of a testis-specific gene 1700001022RIK in mice and its bioinformatic analysis]

OBJECTIVE

To identify the expression characteristics of the 1700001022RIK (RIKEN cDNA 1700001022) gene in mice and explore its function by bioinformatic analysis.

METHODS

Using the expression profile of gene microarray, we detected the expression of a new testis-specific gene, 1700001022RIK, in mice. We analyzed its expression characteristics in the testis tissue and their changes in different developmental stages of the testis by RT-PCR, real-time RT-PCR, Western blot, and immunohistochemistry. We performed bioinformatic analysis using a bioinformatic software.

RESULTS

The 1700001022RIK gene was specifically expressed in the mouse testis in an age-dependent manner, most highly in the adult mice. The 1700001022RIK protein was mainly expressed in the spermatogonia, spermatocytes, and round spermatids of the adult mice. Bioinformatic analysis showed that the 1700001022RIK protein amino acid sequence had a high similarity in human and mice, which indicated that this gene was highly conserved in mammals.

CONCLUSION

1700001022RIK is a testis-specific gene mainly expressed in the spermatogonia, spermatocytes, and round spermatids of seminiferous tubules, which might be involved in the regulation of spermatogenesis.

β-catenin stabilization in gonadotropes impairs FSH synthesis in male mice in vivo

Although classically considered a WNT signaling intermediary, β-catenin (CTNNB1) can also mediate GnRH induction of gonadotropin β-subunit (Fshb and Lhb) transcription in the murine gonadotrope-like cell line LβT2. Here, we assessed CTNNB1's role in gonadotropin synthesis in vivo. We used a Cre/lox approach to introduce both gain- and loss-of-function mutations in the murine Ctnnb1 gene in gonadotrope cells. Gonadotropin production and fertility were normal in Ctnnb1 knockout mice. Similarly, females harboring a deletion of exon 3 of Ctnnb1, which stabilizes the resulting CTNNB1 protein, showed normal fertility and gonadotropin synthesis. Interestingly, males with the activating CTNNB1-Δexon 3 mutation exhibited 50% reductions in FSH synthesis and secretion, without a corresponding change in LH. This selective regulation of FSH suggested an alteration in the activin/inhibin/follistatin system. Indeed, CTNNB1-Δexon 3 males showed a 60% increase in serum inhibin B levels, and in culture, their pituitaries exhibited a greater sensitivity to exogenous inhibin than controls. At the same time, pituitary, but not testicular, follistatin (Fst) expression was increased significantly in these mice. Castration normalized FSH levels in CTNNB1-Δexon 3 males to those seen in castrated controls. Paradoxically, pituitaries from CTNNB1-Δexon 3 males exhibited greater basal and activin-stimulated FSH synthesis in vitro. Similarly, CTNNB1-Δexon 3 overexpression potentiated activin A-induced murine Fshb promoter activity in LβT2 cells. Together, these results indicate that CTNNB1 is dispensable for gonadotropin synthesis in vivo. However, sustained CTNNB1 signaling potentiates activin-induced Fshb expression in gonadotropes, but this effect is overcome in vivo by enhanced inhibin feedback sensitivity and Fst expression.

[Effect of different transfection reagents and injection methods in mice testicular injection on the expression of exogenous gene]

The purpose of this study was to study the effect of three different transfection reagents (Lipofectamine™ LTX & PLUS™, Lipofectamine 2000 and Nano-PAMAM-D) and three different testicular injection methods (rete testicular injection, seminiferous tubules injection and testicular interstitial injection) on the efficiency of production transgenic mice. After the mixtures of plasmid DNA (pEFP-C1) and transfection reagent were injected with different testicular injection methods, the sperm density, vitality, positive sperm rates and PCR positive transgenic mice rate were examined 30 days after injection. The results showed that the damage degree from slight to serious of three transfection reagents was Lipofectamine™ LTX & PLUS™, Lipofectamine 2000, and PAMAM-D. The sperm positive rates with green fluorescence of these three groups were 35.65%±0.69%, 12.86%±0.35% and 10.04%±0.20%, respectively. The PCR positive rates of transgenic newborn mice were 29.17%, 13.70% and 5.88%, respectively. Among the groups of different testicular injection methods, the damage degree from slight to serious was rete testicular injection, seminiferous tubules injection, and testicular interstitial injection, whereas the sperm positive rates with green fluorescence were 35.13%, 15.13%, and 0%, respectively. The PCR positive rates of transgenic newborn mice among different testicular injection groups were 33.3%, 12.5%, and 0.0%. The combination of rete testicular injection and Lipofectamine™ LTX & PLUS™ had the lowest toxicity and highest transgenic efficiency in the production of transgenic mice.

Metabolic rate limits the effect of sperm competition on mammalian spermatogenesis

Sperm competition leads to increased sperm production in many taxa. This response may result from increases in testes size, changes in testicular architecture or changes in the kinetics of spermatogenesis, but the impact of each one of these processes on sperm production has not been studied in an integrated manner. Furthermore, such response may be limited in species with low mass-specific metabolic rate (MSMR), i.e., large-bodied species, because they cannot process energy and resources efficiently enough both at the organismic and cellular levels. Here we compare 99 mammalian species and show that higher levels of sperm competition correlated with a) higher proportions of seminiferous tubules, b) shorter seminiferous epithelium cycle lengths (SECL) which reduce the time required to produce sperm, and c) higher efficiencies of Sertoli cells (involved in sperm maturation). These responses to sperm competition, in turn, result in higher daily sperm production, more sperm stored in the epididymides, and more sperm in the ejaculate. However, the two processes that require processing resources at faster rates (SECL and efficiency of Sertoli cells) only respond to sperm competition in species with high MSMR. Thus, increases in sperm production with intense sperm competition occur via a complex network of mechanisms, but some are constrained by MSMR.

[Cryopreservation of testicular tissue in children]

The toxicity of cancer therapies can affect all organs and tissues. Some treatments damage spermatogonial stem cells (SSCs), with a risk of infertility. Storage and reimplantation of frozen testicular tissue is a recent approach tofertilitypreservationfor young boys. However, thawed frozen prepubertal testicular tissue must undergo a maturation process to restore sperm production. This process, currently being studied in animal models, can be achieved by in vivo transplantation of SSCs into seminiferous tubules or by testicular grafting, possibly following in vitro maturation.

Effects of isoflurane inhalation on the male reproductive system in rats

The 15-day intact adult male assay was used to evaluate effects of isoflurane on the testes and sexual hormones. Forty adult male Sprague-Dawley rats were divided into five groups exposed to air containing 0, 50, 300, 1800 or 10,800 ppm isoflurane. After the treatments, serum was collected for the hormones assay. The right testis was to be used for daily sperm production. The left testis was processed for histopathology and electron microscopy observation. Daily sperm productions were significantly decreased at doses of 300, 1800 and 10,800 ppm. Impaired seminiferous tubules were noted at doses of 300, 1800 and 10,800 ppm. Ultrastructural changes included nucleus agglutination of spermatocytes, big lipid drops and autophagosome in cytoplasm. The serum follicle-stimulating hormone and testosterone concentrations reduced significantly at doses of 1800 and 10,800 ppm. Isoflurane induced impairments of seminiferous tubules and spermatogenesis. The testicular damages caused by isoflurane can be related to the imbalances in the sexual hormones.

Xenogeneic transplantation of equine testicular cells into seminiferous tubules of immunocompetent rats

The objectives were to develop a transplantation assay for equine testicular cells using busulfan-treated prepubertal immunocompetent rats as recipients, and to determine if putative equine spermatogonial stem cells (SSCs) could be enriched by flow cytometric cell sorting (based on light scattering properties), thereby improving engraftment efficiency. Four weeks after transplantation of frozen/thawed PKH26-labeled equine testicular cells, 0.029 ± 0.045% (mean ± SD) of viable donor cells transplanted had engrafted. Donor cells were present in seminiferous tubules of all recipient rats forming chains, pairs, mesh structures, or clusters (with two to >30 cells/structure). Cells were localized to the basal compartment by the basement membrane. Although equine cells proliferated within rat seminiferous tubules, no donor-derived spermatogenesis was evident. Furthermore, there was no histologic evidence of acute cellular rejection. No fluorescent cells were present in control testes. When equine testicular cells were sorted based on light scattering properties, the percentage of transplanted donor cells that engrafted was higher after injection of cells from the small, low complexity fraction (II; 0.169 ± 0.099%) than from either the large, high complexity fraction (I; 0.046 ± 0.051%) or unsorted cells (0.009 ± 0.007%; P < 0.05). Seminiferous tubules of busulfan-treated prepubertal immunocompetent rats provided a suitable niche for engraftment and proliferation, but not differentiation, of equine testicular cells. Sorting equine testicular cells based on light scattering properties resulted in a 19-fold improvement in colonization efficiency by cells with high forward scatter and low side scatter, which may represent putative equine SSCs.

Androgen receptor expression in the caput epididymal epithelium is essential for development of the initial segment and epididymal spermatozoa transit

The epididymis plays an essential role in male fertility, and disruption of epididymal function can lead to obstructive azoospermia. Formation and function of the epididymis is androgen-dependent. The androgen receptor (AR) is expressed in both the stromal and epithelial compartments of the epididymis, and androgen action mediated via stromal cells is vital for its normal development and function. However the impact of epithelial specific AR-dependent signaling in the epididymis remains underexplored. To address this, we used conditional gene-targeting in mice to selectively ablate AR from the caput epididymal epithelium, and characterized the resulting phenotype at multiple postnatal ages. Caput epithelium androgen receptor knock-out mice have normal serum testosterone concentrations at day (d) 21 and d100, but do not develop an epididymal initial segment. The remaining caput epithelium displays a significant decrease in epithelial cell height from d11 and lumen diameter from d21 and disruption of the smooth muscle layer of the caput epididymis at d100. From d21, caput epithelium androgen receptor knock-out mice accumulate cell debris, proteinaceous material, and, at later ages, spermatozoa in their efferent ducts, which prevents normal passage of spermatozoa from the testis into the cauda epididymis resulting in infertility when tested at d100. This efferent duct obstruction leads to fluid back-pressure and disruption of the seminiferous epithelium of the adult testis. We conclude that epithelial AR signaling is essential for postnatal development and function of the epididymal epithelium and that disruption of this signaling can contribute to obstructive azoospermia.

Ex3αERKO male infertility phenotype recapitulates the αERKO male phenotype

Disruption of the Esr1 gene encoding estrogen receptor α (ERα) by insertion of a neomycin resistance gene (neo) into exon 2 (αERKO mice) was shown previously to cause infertility in male mice. While full-length ERα protein was not expressed in αERKO mice, alternative splicing resulted in the low-level expression of a truncated form lacking the N-terminus A/B domain and containing the DNA- and ligand-binding domains. Thus, it was unclear whether the reproductive phenotype in αERKO males was only due to the lack of full-length ERα or was affected by the presence of the variant ERα isoform. The present study examined male mice with deletion of exon 3 of Esr1 gene, lacking the DNA-binding domain, and null for ERα (Ex3αERKO). Dilation of some seminiferous tubules was apparent in male Ex3αERKO mice as early as postnatal day 10 and was pronounced in all tubules from day 20 onward. At 6 weeks of age, sperm numbers and sperm motility were lower in Ex3αERKO mice than in wild-type (WT) mice, and the rete testis and efferent ductules were dilated. Mating studies determined that adult Ex3αERKO males were infertile and failed to produce copulatory plugs. Serum testosterone levels and Hsd17b3 and Cyp17a1 transcript levels were significantly higher, but serum estradiol, progesterone, LH, and FSH levels and Cyp19a1 transcript levels were not significantly different from those in WT mice. These results confirm and extend those seen in other studies on male mice with deletion of exon 3 of Esr1 gene. In addition, the reproductive phenotype of male Ex3αERKO mice recapitulated the phenotype of αERKO mice, strongly suggesting that the αERKO male infertility was not due to the presence of the DNA-binding domain in the truncated form of ERα and that full-length ERα is essential for maintenance of male fertility.

Successful transplantation of bovine testicular cells to heterologous recipients

While heterologous germ cell transplantation was successful in pigs and goats, autologous transplantation alone has been reported to result in donor-derived spermatogenesis in cattle. The objective of this study was to investigate whether the transplantation of heterologous germ cells could result in colonization of recipient testes in cattle of different breeds. Testicular cells were isolated from 8 Bos taurus donor bull calves and then transferred into 15 Bos indicus-cross bull calves. All animals were prepubertal, donors were aged 5-7 months and recipients 5-11 months, and scrotal circumferences ranged from 15 to 22 cm. Single cell suspensions of donor testicular cells, prepared by enzymatic digestion, were labelled with fluorescent dyes PKH26 or CFDA-SE, before transfer into the rete testis of recipients under ultrasonographic guidance. To assess the longevity of colonization by donor cells, recipients were castrated 2-30 weeks after cell transfer. Donor cells were observed in 15/25 (60%) of the testes that received PKH26-labelled cells, whereas no CFDA-SE-positive cell was identified in any recipients. The maturity of the donors or recipients (measured by scrotal circumference) did not affect colonization potential. In freshly isolated tubules, clumps of PKH26-positive cells were observed, which indicated either cell division or extensive local colonization of specific areas of the tubules. In frozen sections, PKH26-positive cells were identified on the seminiferous tubule basement membrane, which indicated that these cells had successfully migrated from the tubule lumen and were likely to be spermatogonia. We conclude that PKH26 was more suitable for labelling donor testis cells and donor cells can be identified up to 6 months following transfer. These results indicate that allogeneic transplantation of testicular cells can occur between Bos taurus and Bos indicus cattle. Further studies will investigate functionality of transferred testicular cells.

ITGCN of the Testis, Contralateral Testicular Biopsy and Bilateral Testicular Cancer

Over 30 years ago Skakkebaek was the first to characterize a noninvasive precursor lesion (intratubular germ cell neoplasia or carcinoma in situ) that would progress to invasive testicular tumors. In this article we discuss the molecular changes thought to cause this malignant transformation, various conditions that predispose to the development of testicular germ cell tumors, diagnostic strategies, and treatment options. Additionally we discuss the current patterns of contralateral testicular biopsy to identify intratubular germ cell neoplasia, as well as the incidence and management of bilateral testicular tumors.

[Generation of transgenic mice by intratesticular injection and electroporation in vivo]

OBJECTIVE

To evaluate the feasibility of establishing transgenic mice by means of seminiferous tubule microinjection and electroporation (EP) in vivo.

METHODS

Specific pathogen-free (SPF) male Kunming mice divided into 4 groups were subjected to microinjection of two different transfection solutions labeled with enhance green fluorescent protein (EGFP) into the seminiferous tubule of the testis, and in one of the two groups receiving the identical transfection solutions, EP in vivo was performed. After two weeks, the male mice of each group were mated with SPF female Kunming mice with superovulation treatment, and PCR coupled with Southern blotting was performed for the offspring mice.

RESULTS

The results of PCR suggested significant difference in the efficiency of exogenous gene integration between the 4 groups (P<0.01), among which group A achieved the greatest efficiency (45%). Southern blotting did not identify significant difference between the 4 groups (P>0.05), but still suggested the highest efficiency in group A (25%).

CONCLUSION

Seminiferous tubule microinjection in conjunction with subsequent EP in vivo can remarkably enhance the integration efficiency of exogenous genes into the host genome, but this new method needs to be further tested for its potential utility in transgenic animal generation.

Restoration of spermatogenesis and male fertility by transplantation of dispersed testicular cells in the chicken

Transplantation of male germ cells into sterilized recipients has been widely used in mammals for conventional breeding and transgenesis purposes. This study presents a workable approach for germ cell transplantation between male chickens. Testicular cells from adult and prepubertal donors were dispersed and transplanted by injection directly into the testes of recipient males sterilized by repeated gamma irradiation. We describe the repopulation of the recipient seminiferous epithelium up to the production of heterologous sperm in about 50% of transplanted males. In comparison to males transplanted with testicular cell preparations from adult donors, in which the first ejaculates with sperm were recovered about 5 wk after transfer, a substantial interval (about 10 wk) was necessary to obtain ejaculates after the transfer of testicular cells from prepubertal donors. However, in both cases, recipient males produced ejaculates capable of fertilizing ova and producing progeny expressing donor genes.