EphB2, EphB4, and ephrin-B1 expression and localization in postnatal developing epididymis in mice.

BACKGROUND: Eph receptors and ephrin ligands, the transmembrane proteins, function as a mechanism of communication between cells. Therefore, we intended to explore the expression array of EphB2 and EphB4 receptors and ephrin-B1 ligand in postnatal developing mouse epididymis during 1 day to 8 weeks using RT-PCR amplification and immunofluorescence staining. RESULTS: RT-PCR analysis indicated that the expression levels of EphB2, EphB4, and ephrin-B1 in the epididymis declined with the advancement of age during the initial phases of postnatal development and stayed relatively near to adult levels until 4 weeks. We discovered that the predominant compartments expressing EphB2/B4 and ephrin-B1 emerged in the excurrent duct epithelia of postnatal developing epididymis until 3 weeks. Consequently, even before spermatozoa reach the excurrent duct in epididymis, at the age of 3 weeks, the epididymal excurrent duct system exhibits characteristics similar to those of an adult in terms of expression of EphB2/B4 and ephrin-B1. Moreover, ephrin-B1 was expressed in epididymal epithelial cells throughout the development and EphB4 was expressed only in early postnatal stages while basal cells expressed EphB4 throughout the postnatal development. CONCLUSION: The study represents the first expression analysis of ephrin-B1, EphB2, and EphB4 in the normal mouse epididymis during the postnatal development.

The role of S-palmitoylation of C4BPA in regulating murine sperm motility and complement resistance.

The epididymis and epididymosomes are crucial for regulating sperm motility, a key factor in male fertility. Palmitoylation, a lipid modification involving the attachment of palmitic acid to cysteine residues, is essential for protein function and localization. Additionally, this modification plays a vital role in the sorting of proteins into exosomes. This study investigates the role of S-palmitoylation at the Cys15 residue of the C4b binding protein alpha chain (C4BPA) in murine sperm motility. Our findings revealed high expression of C4BPA mRNA in the caput epididymis, with the protein present across all regions of the epididymis. Palmitoylation of C4BPA in epididymal epithelial cells was essential for its enrichment in epididymosomes and on sperm, thereby maintaining sperm motility. Inhibition of palmitoylation significantly reduced sperm motility and the localization of C4BPA on sperm. Additionally, palmitoylated C4BPA in exosomes resisted complement C4 attacks, preserving motility, unlike mutated C4BPA (C15S). These results highlight the critical role of palmitoylated C4BPA in protecting sperm from complement attacks and maintaining motility, suggesting that reversible palmitoylation of epididymal proteins could be explored as a therapeutic strategy for male contraception. Our study underscores the importance of post-translational modifications in sperm function and presents new insights into potential male contraceptive methods.

hACE2 upregulation and participation of macrophages and clear cells in the immune response of epididymis to SARS-CoV-2 in K18-hACE2 mice.

BACKGROUND: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus caused the coronavirus disease 2019 pandemic, and the prevalence of deaths among men is higher than among women. The epididymis, divided into caput, corpus, and cauda, shows a region-specific immunity. The K18-hACE2 mouse expresses human angiotensin-converting enzyme 2 (hACE2), the receptor that allows SARS-CoV-2 infection. However, studies using this transgenic mouse to evaluate the impact of this viral infection in epididymis have not yet been performed. OBJECTIVES: We evaluated the expression of hACE2 in the epididymis of SARS-CoV-2-infected K18-hACE2 mice, and assessed the epididymal immune response, focusing on F4/80+ mononuclear phagocytes and tumor necrosis factor-alpha expression. MATERIALS AND METHODS: The following analyses were performed in the epididymal sections of infected mice: epithelial height and duct diameter, birefringent collagen, Terminal deoxynucleotidyl Transferase-mediated dUTP Nick End Labelling, immunoreactions for detection of hACE2, spike, FGF, V-ATPase, F4/80, tumor necrosis factor-alpha, and iNOS. Viral particles were identified under electron microscopy. hACE2, Rigi, Tgfb1 and Tnfa expression were also evaluated by real-time quantitative polymerase chain reaction. RESULTS: All epididymal regions expressed hACE2, which increased in all epididymal regions in the infected mice. However, the caput appeared to be the most infected region. Despite this, the caput region showed minimal changes while the cauda showed significant epithelial changes associated with increased iNOS immunoexpression. The F4/80+ mononuclear phagocyte area increased significantly in both stroma and epithelium. In addition to the epithelial and stromal mononuclear phagocytes, tumor necrosis factor-alpha was also detected in clear cells, whose cytoplasm showed a significant increase of this cytokine in the infected animals. DISCUSSION AND CONCLUSION: The K18-hACE2 mouse is a useful model for evaluating the impact of SARS-CoV-2 infection in the epididymis. The infection induced hACE2 upregulation, favoring the virulence in the epididymis. The epididymal regions responded differentially to infection, and the activation of F4/80+ mononuclear phagocytes associated with the increased tumor necrosis factor-alpha immunolabeling in clear cells indicates a role of clear cells/mononuclear phagocytes immunoregulatory mechanisms in the epididymal immune response to SARS-CoV-2 infection.

Epididymosomes: Composition and Functions for Sperm Maturation.

This article provides an overview of literature pertaining to epididymosome origin, composition and their functional significance. Broadly, epididymosomes are defined as extracellular vesicles that are secreted by the epididymal epithelium and thereafter facilitate intercellular communication within the male reproductive tract. Epididymosomes fulfil this communication role via their encapsulation and delivery of a diverse macromolecular payload to recipient cells. This complex cargo includes proteins, lipids, and nucleic acids, which are delivered to maturing spermatozoa, thereby influencing their viability and function. Additionally, epididymosomes have been implicated in the post-translational modification of intrinsic sperm proteins, protection of sperm from oxidative stress and immune surveillance, and in the transmission of epigenetic information capable of mediating intergenerational effects. Hence, continued research into the biogenesis, cargo composition, and functional significance of epididymosomes holds promise for advancing male reproductive health and fertility treatments.

Nomogram using human epididymis protein 4 predicted concurrent endometrial cancer from endometrial atypical hyperplasia before surgery.

Objective: To establish a nomogram based on presurgical predictors of concurrent endometrial cancer (EC) for patients diagnosed with endometrial atypical hyperplasia before definitive surgery (preoperative-EAH) to improve the risk stratification and clinical application. Methods: Preoperative-EAH patients who underwent hysterectomy in a tertiary hospital from January 2020 to December 2022 were retrospectively analyzed. Independent predictors from the multivariate logistic regression model were used to establish a nomogram, and bootstrap resampling was used for internal validation. Results: Of 370 preoperative-EAH patients, 23.4% were diagnosed with EC after definitive surgery (final-EC). Multivariate analyses found three independent predictors of final EC: human epididymis protein 4 (HE4) ≥43.50 pmol/L [odds ratio (OR) = 3.70; 95% confidence intervals (CI) = 2.06-6.67], body mass index (BMI) ≥ 28 kg/m2 (OR = 2.05; 95% CI = 1.14-3.69), and postmenopausal status, particularly at postmenopausal time ≥5 years (OR = 5.84, 95% CI = 2.51-13.55), which were used to establish a nomogram model. The bootstrap-corrected C-index of the nomogram was 0.733 (95% CI = 0.68-0.79), which was significantly higher than that of each individual factor. The calibration curve and decision curve showed good consistency and clinical net benefit of the model. At the maximum Youden index, 49.4% (43/87) of women in the high-risk group defined by nomogram had concurrent EC, versus 16.6% in the low-risk group (P< 0.001). Conclusion: The nomogram based on HE4, menopausal status, and BMI was found with an improved predictive value to stratify preoperative-EAH patients at high risk of concurrent EC for better clinical management.

Tubular Ectasia of the Epididymis: A Case Report and Literature Review.

Tubular ectasia of the epididymis is a rare benign disorder that, when present, is usually seen in patients post-vasectomy. It can also be seen in patients with a prior history of trauma or local infection. Patients typically present with a palpable scrotal mass and dull-aching pain. It is important to differentiate this disease from other common disorders such as varicocele, hydrocele, spermatocele, or even testicular malignancy. We report a rare case of tubular ectasia of the epididymis in a 55-year-old patient with palpable scrotal swelling with no prior operative history of vasectomy nor any history of trauma. We share this patient's ultrasonography findings along with a literature review of this uncommon disease.

Increased serum human epididymis protein 4 is associated with disease activity and systemic involvement in pediatric-onset systemic lupus erythematosus.

Objective: We aimed to investigate human epididymis protein 4 (HE4) as a potential biomarker in patients with pediatric-onset systemic lupus erythematosus (pSLE), particularly on the association of serum HE4 levels with disease activity and other laboratory tests. Methods: We included 137 patients with pSLE and 75 age- and sex-matched healthy controls (HCs). Serum HE4 level was measured by a chemiluminescent microparticle on an Abbott ARCHITECT i2000SR Immunoassay Analyzer. Comparisons between groups were performed using the independent Student t-test, Mann-Whitney U test, Chi-square test, or Fisher's exact test, as appropriate. We also determined the relationships between HE4 and clinical parameters and evaluated disease activity using SLE Disease Activity Index (SLEDAI) and renal SLEDAI (rSLEDAI). Results: Serum HE4 levels in patients with pSLE (44.6 pmol/L; IQR, 32.5-73.5) were significantly higher than those in HCs (38.9 pmol/L; IQR, 34-46.1). HE4 levels were significantly higher in moderate to severe disease activities (57.4 pmol/L, IQR 37.7-164.5) than in mild disease activities (38.8 pmol/L, IQR 30.1-48.5) or HCs (38.9 pmol/L, IQR 34.0-46.1), as well as in active renal disease activities (77.2 pmol/L, IQR 47.4-224.1) than in inactive renal disease activities (36.1 pmol/L, IQR 27.8-46.7). The ROC curve analysis showed that HE4 could discriminate pSLE with renal (AUC, 0.717; 95% CI, 0.632-0.801), hematological (AUC, 0.740; 95% CI, 0.648-0.831), and cardiovascular involvement (AUC:0.775, 95% CI 0.669-0.880). Serum HE4 levels significantly correlated with several indicators related to renal morbidity, such as creatinine, blood urea nitrogen, uric acid, cystatin C, urine protein/24 h, etc. Conclusion: Serum HE4 levels in pSLE were elevated and highly associated with disease activity and systemic involvement, indicating HE4 as a potential biomarker for pSLE.

Epididymal acquired sperm microRNAs modify post-fertilization embryonic gene expression.

Sperm small RNAs have emerged as important non-genetic contributors to embryogenesis and offspring health. A subset of sperm small RNAs is thought to be acquired during epididymal transit. However, the identity of the specific small RNAs transferred remains unclear. Here, we employ Cre/Lox genetics to generate germline- and epididymal-specific Dgcr8 knockout (KO) mice to investigate the dynamics of sperm microRNAs (miRNAs) and their functions post-fertilization. Testicular sperm from germline Dgcr8 KO mice has reduced levels of 116 miRNAs. Enthrallingly, following epididymal transit, the abundance of 72% of these miRNAs is restored. Conversely, sperm from epididymal Dgcr8 KO mice displayed reduced levels of 27 miRNAs. This loss of epididymal miRNAs in sperm was accompanied by transcriptomic changes in embryos fertilized by this sperm, which was rescued by microinjection of epididymal miRNAs. These findings ultimately demonstrate the acquisition of miRNAs from the soma by sperm during epididymal transit and their subsequent regulation of embryonic gene expression.

Role of Fine Needle Aspiration Cytology in Paratesticular Neoplasms-A Case Reports-Based Systematic Review.

INTRODUCTION: The cytology features of neoplastic paratesticular lesions are mostly documented as case reports. Thus, we conducted a case report-based literature review to identify the characteristics of paratesticular neoplasms and tried to determine the significance of FNAC in these tumors. METHODS AND MATERIALS: The studies were searched using PubMed and Scopus. The quality assessment was done using the JBI critical appraisal checklist for case reports. The articles that received an overall rating of "Include" underwent data extraction. The data were extracted from the articles and analyzed. RESULTS: We included 34 case reports from 33 published articles. The mean age of patients was 44.74 (13-85) years, and the most common clinical manifestation was scrotal swelling (70.59%, 24/34). Lesions were commonly observed on the right side (65.63%, 21/32), and the most common tumor site was epididymis (35.29%, 12/34). A total of 38.24% (13/34) cases were nonmalignant, and 61.76% (21/34) were malignant on the cytological diagnosis. The adenomatoid tumor (53.85, 7/13) was the most common nonmalignant tumor. Other entities were schwannoma, benign spindle cell neoplasm with atypia, nerve sheath tumor, lipoma, undifferentiated pleomorphic sarcoma, rhabdomyosarcoma, epithelioid sarcoma, liposarcoma, malignant rhabdoid tumor, pigmented neuroectodermal tumor of infancy and mesothelioma. Considering the malignant and nonmalignant groups, the sensitivity, specificity, and diagnostic accuracy of cytology were 95.00%, 84.62%, and 90.91%, respectively. CONCLUSION: Cytopathologists should be familiar with the cytological features of various malignant and nonmalignant paratesticular tumors to prevent unnecessarily invasive surgical management. The current systematic review emphasizes usefulness of FNAC in the preoperative cytological identification of paratesticular tumors.

Anatomy of the Male Reproductive System of Sugar Gliders (Petaurus breviceps).

The present study provides a detailed macroscopic examination (with some microscopic insights) of the genital apparatus of seven adult and intact male sugar gliders, as well as one castrated individual. The scrotum is pendulous and attached to the ventral abdominal wall, situated in the caudal part of the abdomen and cranial to the cloacal opening. The testes are oval shaped with their long axes oriented vertically. The epididymides are attached along the caudomedial border of their respective testes. The head and tail of the epididymides are in close proximity to the poles of the testes but are not directly attached. The deferent ducts are positioned laterally to their ipsilateral ureter as they run near the dorsal surface of the urinary bladder. The ampulla of the deferent duct is absent. The penis is located post-scrotally, lacks insertion into the bony pelvis, and has a bifid distal end. The crura of the penis originate within the ischiocavernosus muscles, and there are two bulbs of the penis. When flaccid, the entire penis is concealed in the perineal region and externalizes through an orifice situated in the ventral part of the cloaca, traversing its floor towards the cloacal opening. The urethral external orifice is positioned at the point where the bifurcation of the free part of the penis begins. The prostate gland resides in the pelvic cavity and consists of two parts: a macroscopically visible body surrounding the urethra and a microscopically identifiable portion embedded within the walls of the duct. Sugar gliders possess two pairs of bulbous bulbourethral glands, located dorsally and laterally to the rectum, but lack vesicular glands.

Physiological and pathological aspects of epididymal sperm maturation.

In mammals, sperm that leave the testes are nonfunctional and require a complex post-testicular maturation process to acquire their ability to recognize and fertilize the egg. The crucial maturation changes that provide sperm their fertilizing capability occur while passing through the epididymis. Due to the widespread use of assisted reproductive technologies to address male infertility, there has been a significant decrease in research focusing on the mechanisms underlying the maturation process over the past decades. Considering that up to 40% of male infertility is idiopathic and could be reflecting sperm maturation defects, the study of post-testicular sperm maturation will clearly contribute to a better understanding of the causes of male infertility and to the development of both new approaches to maturing sperm in vitro and safer male contraceptive methods. Based on this, the present review focuses on the physiopathology of the epididymis as well as on current approaches under investigation to improve research in sperm maturation and as potential therapeutic options for male infertility.

Characterization of gonadotropins and their receptors in a chondrichthyan, Scyliorhinus canicula, fills a gap in the understanding of their coevolution.

In Gnathostomes, reproduction is mainly controlled by the hypothalamic-pituitary-gonadal (HPG) axis, with the involvement of the pituitary gonadotropic hormones (GTH), follicle-stimulating hormone (FSH) and luteinizing hormone (LH), which activate their cognate receptors, FSHR and LHR, expressed in gonads. Each GTH consists of a common α subunit and of a specific FSHß or LHß subunit. Chondrichthyes (holocephalans and elasmobranchs) is a sister group of bony vertebrates. This position is highly favorable for the understanding of the evolution of endocrine regulations of reproduction among gnathostomes. Surprisingly, the characterization of gonadotropins and their receptors is still limited in chondrichthyes. In the present study, GTH and GTHR sequences have been identified from several chondrichthyan genomes, and their primary structures were analyzed relative to human orthologs. 3D models of GTH/GTHR interaction were built, highlighting the importance of the receptor hinge region for ligand recognition. Functional hormone-receptor interactions have been studied in HEK cells using the small-spotted catshark (Scyliorhinus canicula) recombinant proteins and showed that LHR was specifically activated by LH whereas FSHR was activated by both FSH and LH. Expression profiles of GTHs and their receptors were explored by real-time PCR, in situ hybridization and immunohistochemistry during spermatogenesis, along the male genital tract and other tissues, as well as in some female tissues for comparison. Tissue-expression analyses showed that the highest levels were observed for fshr transcripts in testis and ovary and for lhr in specific extragonadal tissues. The two receptors were expressed at all stages of spermatogenesis by both germ cells and somatic cells, including undifferentiated spermatogonia, spermatocytes, spermatids, somatic precursors and Sertoli cells; differentiated Leydig cells being absent in the testis of S. canicula. Receptors were also expressed by the lymphomyeloid epigonal tissue and the testicular tubules. These results, suggest a wide range of gonadotropin-regulated functions in Elasmobranchs, as well as functional redundancy during spermatogenesis. These extended functions are discussed in an evolutionary context in which the specificity of gonadotropin signaling must have contributed to the evolution of gonadal cells' morphology and function.

The diagnostic performance of the Mindray system in detecting CA125 and HE4 for patients with ovarian cancer.

Background: Cancer antigen 125 (CA125) and human epididymis protein 4 (HE4) are the most commonly used tumor biomarkers for ovarian cancer (OC) screening and diagnosis. The risk of ovarian malignancy algorithm (ROMA) score uses these markers, as detected by the Roche system, to predict the risk of OC. This study sought to assess the performance of the Mindray system in detecting CA125 and HE4 for ROMA score calculation in clinical settings. Methods: Consecutive OC patients and patients with benign pelvic masses were screened and enrolled in this study. The CA125 and HE4 levels of these patients were measured using both the Mindray and Roche systems. The ROMA score for each patient was calculated. Diagnostic performance was evaluated using the area under the curve (AUC) of the receiver operating characteristic (ROC) curve. Results: The HE4 and CA125 levels were significantly higher in the patients with OC than the patients with benign ovarian masses. Both detection systems showed high efficiency in detecting ovarian cancer. For the premenopausal OC patients, the AUC values for the ROMA score, HE4, and CA125 were 0.866, 0.852, and 0.879, respectively, using the Roche system, and 0.911, 0.902, and 0.883, respectively, using the Mindray system. For the postmenopausal OC patients, the AUC values for the ROMA score, HE4, and CA125 were 0.962, 0.920, and 0.953, respectively, using Roche system, and 0.966, 0.924, and 0.959, respectively, using the Mindray system. The correlation analysis showed strong agreement between the two systems. Among the patients who experienced recurrence, we observed a significant increase in both HE4 and CA125 levels compared to baseline using the Mindray system. Conclusions: The Mindray and Roche systems provide consistent results. The Mindray system can be used to detect HE4 and CA125 for ROMA score calculation.

Zinc and Its Impact on the Function of the Testicle and Epididymis.

Zinc (Zn) is an essential trace element; it exhibits a plethora of physiological properties and biochemical functions. It plays a pivotal role in regulating the cell cycle, apoptosis, and DNA organization, as well as in protein, lipid, and carbohydrate metabolism. Among other important processes, Zn plays an essential role in reproductive health. The ZIP and ZnT proteins are responsible for the mobilization of Zn within the cell. Zn is an inert antioxidant through its interaction with a variety of proteins and enzymes to regulate the redox system, including metallothioneins (MTs), metalloenzymes, and gene regulatory proteins. The role of Zn in the reproductive system is of great importance; processes, such as spermatogenesis and sperm maturation that occur in the testicle and epididymis, respectively, depend on this element for their development and function. Zn modulates the synthesis of androgens, such as testosterone, for these reproductive processes, so Zn deficiency is related to alterations in sperm parameters that lead to male infertility.

The expression spectrum of yak epididymal epithelial cells reveals the functional diversity of caput, corpus and cauda regions.

Sperm undergo a series of changes in the epididymis region before acquiring the ability to move and fertilize, and the identification of genes expressed in a region-specific manner in the epididymis provides a valuable insight into functional differences between regions. We collected epididymal tissue from three yaks and cultured epithelial cells from the caput, corpus and cauda regions of the yak epididymis using the tissue block method. RNA sequencing analysis (RNA-seq) technology was used to detect gene expression in yak epididymal caput, corpus and cauda epithelial cells. The results showed that the DEGs were highest in the caput vs. corpus comparison, and lowest in the corpus vs. cauda comparison. Six DEGs were verified by real-time fluorescence quantitative PCR (qRT-PCR), consistent with transcriptome sequencing results. The significantly enriched DNA replication pathway in the caput vs. corpus was coordinated with cell proliferation, while upregulated DEGs such as POLD1 and MCM4 were found in the DNA replication pathway. The AMPK signaling pathway was found significantly enriched in the caput vs cauda, suggesting its involvement in sperm maturation and capacitation. The TGF beta signaling pathway was screened in the corpus vs cauda and is crucial for mammalian reproductive regulation. Upregulated DEGs (TGFB3, INHBA, INHBB) are involved in the TGF beta signaling pathway. This study provides a reference for culturing yak epididymal epithelial cells in vitro, and elucidates the transcriptional profiles of epithelial cells in different segments of the epididymis, revealing the regulatory and functional differences between different segments, providing basic data for exploring the molecular mechanism of yak sperm maturation and improving the reproductive capacity of high-altitude mammals.

Analysis of histomorphology and SERNINA5 gene expression in different regions of epididymis of cattleyak.

The molecular mechanism of sterility in cattleyak is still unresolved. The related factors of infertility in cattleyak were studied by tissue section, SERPINA5 gene cloning and bioinformatics technology. Tissue sections of the epididymis showed poorly structured and disorganized epithelial cells in the corpus of the epididymis compared to the caput of the epididymis, while in the cauda part of the epididymis, the extra basal smooth muscle was thinner, the surface of the epithelial lumen was discontinuous and the epithelium was markedly degenerated. The results of gene cloning showed that the coding sequence (CDS) region of the SERPINA5 gene in cattleyak was 1215 bp in length, encoding a total of 404 amino acids, of which the isoleucine content was the highest, accounting for a total of 49 amino acids (12.1%). The results of real-time fluorescence quantitative PCR (qPCR) showed that the expression of the SERPINA5 gene in the epididymis caput in cattleyak was significantly higher than that in the corpus and cauda (P < 0.05), but there were no significant differences between the corpus and cauda. In the current study, histological and bioinformatics analysis, physicochemical properties, and the expression analysis of the SERPINA5 gene in different regions of the epididymis in cattleyak were carried out to explore the biological complications of cattleyak infertility.

A case report of human primary renal cystic echinococcosis.

In humans, solitary renal involvement or primary renal echinococcosis is rare, accounting for about 2-4 % of cases. Usually, patients shpw no obvious symptoms, but they can manifest as renal pain, renal mass, gross hematuria, and hydatiduria in rare cases. We report a case of primary renal cystic echinococcosis, which was originally misdiagnosed as a tuberculous renal abscess.

Impact of chronic sleep deprivation on male reproductive health: Insights from testicular and epididymal responses in mice.

BACKGROUND: Sleep deprivation (SD) can cause damage to the male reproductive system. However, the duration required for such damage and the specific sequence and severity of damage to the testis and epididymis remain unclear. OBJECTIVE: To investigate the effects of different durations of SD on different parts of the testis and epididymis caput, corpus, and cauda. METHODS: Adult ICR mice were randomly assigned to five groups: the SD group (SD for 18 h/day for 1, 2, 3, or 4 weeks), the SD + Vit E group (supplemented with Vit E 50 mg/kg/d during 4 weeks of SD, the SD+NS group (saline supplementation during 4 weeks of SD), the SD + RS group (5 weeks of recovery sleep after 4 weeks of SD), and a normal sleep control (Ctrl) group. Following the interventions, sperm parameters, testicular and epididymal histopathology, inflammatory response, and oxidative stress markers were compared between the groups. RESULTS: Compared to the Ctrl group, the SD group showed a decrease in sperm motility and concentration from SD 2 W and SD 3 W, respectively. Decreases in sperm concentration and motility were more pronounced in the cauda compared to the caput and corpus. Pathological damage was less severe in the epididymis caput than in the corpus and cauda. After 4 weeks of SD, inflammation and oxidative stress increased in both testes and epididymis. Both sleep recovery and vitamin E supplementation showed significant improvements, though they did not fully reach the level of the Ctrl group. CONCLUSION: Chronic SD for more than 2 weeks causes varying degrees of damage to the testis, epididymis caput, corpus, and cauda in male mice. This damage is not fully reversible after 5 weeks of sleep recovery and antioxidant stress treatment. These findings help us to identify and prevent SD damage to the male reproduction at an early stage.

Epididymal mRNA expression profiles for the protein disulfide isomerase gene family: Modulation by development and androgens.

BACKGROUND: The endoplasmic reticulum (ER) is the central hub for protein quality control, where the protein disulfide isomerases (PDIs), encoded by at least 21 genes, play a pivotal role. These multifunctional proteins contribute to disulfide bond formation, proper folding, and protein modifications, and may act as hormone-binding proteins (e.g., steroids), influencing hormone biology. The interplay between ER proteostasis, PDIs, and epididymis-a crucial site for sperm maturation-remains largely understudied. OBJECTIVES: This study characterizes transcriptional signatures of Pdi genes in the epididymis. MATERIAL AND METHODS: Transcriptional profiles of selected Pdi genes were assessed in adult Wistar rat tissues, and epididymis under different experimental conditions (developmental stages, surgical castration, and efferent ductules ligation [EDL]). In silico bioinformatic analyses identified expression trends of this gene family in human epididymal segments. RESULTS: P4hb, Pdia3, Pdia5, Pdia6, Erp44, Erp29, and Casq1 transcripts were detected in both reproductive and non-reproductive tissues, while Casq2 exhibited higher abundance in vas deferens, prostate, and heart. Pdilt, highly expressed in testis, and Pdia2, highly expressed in heart, showed minimal mRNA levels in the epididymis. In the mesonephric duct, epididymal embryonic precursor, P4hb, Pdia3, Pdia5, Pdia6, and Erp29 mRNAs were found at gestational day (GD) 17.5. Except for Erp29, which remained stable, these Pdi transcript levels increased from GD17.5 to GD20.5, when epididymal morphogenesis occurs, and were maintained to varying degrees in the epididymis during postnatal development. Surgical castration downregulated P4hb, Pdia3, Pdia5, Pdia6, Pdilt and Erp29 transcripts, an effect reversed by testosterone replacement. Conversely, transcript levels remained unaffected by EDL, except P4hb, which was reduced in caput epididymis. All 21 PDI genes exhibited diverse transcriptional profiles across the human epididymis. DISCUSSION AND CONCLUSION: The findings lay the foundations to explore Pdi genes in epididymal biology. As a considerable proportion of male infertility cases are idiopathic, targeting hormonal regulation of protein quality control in epididymis represents a route to address male infertility and advance therapeutic interventions in this domain.

Extracellular vesicles are involved in the paracrine communication between epithelial cells in different regions of the domestic cat epididymis.

Sperm maturation depends on exposure to specific microenvironments within the different segments of the epididymis, but mechanisms underlying how these microenvironments are produced or maintained are not well understood. We hypothesized that epididymal extracellular vesicles (EVs) could play a role in the process of maintaining microenvironments in different regions of the epididymis. Specifically, we tested whether the EVs from different regions of the epididymis can serve as a form of paracrine communication between cells in different segments. Domestic cat tissues were used to develop a reproducible in vitro culture system for corpus epididymis explants that were then exposed to EVs collected from upstream (i.e. caput) segments. The impacts of different culture or exposure conditions were compared by analyzing the morphology, apoptosis, transcriptional activity, and gene expression in the explants. Here, we report the development of the first in vitro culture system for epididymal tissue explants in the domestic cat model. Using this system, we found that EVs from the caput segment have a significant effect on the transcriptional profile of tissue from the corpus segment (1233 differentially expressed genes due to EV supplementation). Of note, expression of genes associated with regulation of epithelial cell differentiation and cytokine signaling in the epididymis were regulated by the presence of EVs. Together, our findings comprise the first report of paracrine control of segmental gene regulation by epididymal EVs in any species. These results contribute to a better understanding of epididymis biology and could lead to techniques to enhance or suppress male fertility.