CX3CR1 deficiency leads to impairment of immune surveillance in the epididymis

Mononuclear phagocytes (MPs) play an active role in the immunological homeostasis of the urogenital tract. In the epididymis, a finely tuned balance between tolerance to antigenic sperm and immune activation is required to maintain epididymal function while protecting sperm against pathogens and stressors. We previously characterized a subset of resident MPs that express the CX3CR1 receptor, emphasizing their role in antigen sampling and processing during sperm maturation and storage in the murine epididymis. Bacteria-associated epididymitis is the most common cause of intrascrotal inflammation and frequently leads to reproductive complications. Here, we examined whether the lack of functional CX3CR1 in homozygous mice (CX3CR1EGFP/EGFP, KO) alters the ability of MPs to initiate immune responses during epididymitis induced by LPS intravasal-epididymal injection. Confocal microscopy revealed that CX3CR1-deficient MPs located in the initial segments of the epididymis displayed fewer luminal-reaching membrane projections and impaired antigen capture activity. Moreover, flow cytometry showed a reduction of epididymal KO MPs with a monocytic phenotype under physiological conditions. In contrast, flow cytometry revealed an increase in the abundance of MPs with a monocytic signature in the distal epididymal segments after an LPS challenge. This was accompanied by the accumulation of CD103+ cells in the interstitium, and the prevention or attenuation of epithelial damage in the KO epididymis during epididymitis. Additionally, CX3CR1 deletion induced downregulation of Gja1 (connexin 43) expression in KO MPs. Together, our study provides evidence that MPs are gatekeepers of the immunological blood-epididymis barrier and reveal the role of the CX3CR1 receptor in epididymal mucosal homeostasis by inducing MP luminal protrusions and by regulating the monocyte population in the epididymis at steady state as well as upon infection. We also uncover the interaction between MPs and CD103+ dendritic cells, presumably through connexin 43, that enhance immune responses during epididymitis. Our study may lead to new diagnostics and therapies for male infertility and epididymitis by identifying immune mechanisms in the epididymis.

Activation of PTH1R alleviates epididymitis and orchitis through Gq and β-arrestin-1 pathways

Inflammation in the epididymis and testis contributes significantly to male infertility. Alternative therapeutic avenues treating epididymitis and orchitis are expected since current therapies using antibiotics have limitations associated to side effects and are commonly ineffective for inflammation due to nonbacterial causes. Here, we demonstrated that type 1 parathyroid hormone receptor (PTH1R) and its endogenous agonists, parathyroid hormone (PTH) and PTH-related protein (PTHrP), were mainly expressed in the Leydig cells of testis as well as epididymal epithelial cells. Screening the secretin family G protein-coupled receptor identified that PTH1R in the epididymis and testis was down-regulated in mumps virus (MuV)- or lipopolysaccharide (LPS)-induced inflammation. Remarkably, activation of PTH1R by abaloparatide (ABL), a Food and Drug Administration-approved treatment for postmenopausal osteoporosis, alleviated MuV- or LPS-induced inflammatory responses in both testis and epididymis and significantly improved sperm functions in both mouse model and human samples. The anti-inflammatory effects of ABL were shown to be regulated mainly through the Gq and β-arrestin-1 pathway downstream of PTH1R as supported by the application of ABL in Gnaq± and Arrb1-/- mouse models. Taken together, our results identified an important immunoregulatory role for PTH1R signaling in the epididymis and testis. Targeting to PTH1R might have a therapeutic effect for the treatment of epididymitis and orchitis or other inflammatory disease in the male reproductive system.

Lipopolysaccharide and lipotheicoic acid differentially modulate epididymal cytokine and chemokine profiles and sperm parameters in experimental acute epididymitis

Bacterial infections are the most prevalent etiological factors of epididymitis, a commonly diagnosed inflammatory disease in the investigation of male infertility factors. The influence of early pathogenic mechanisms at play during bacterial epididymitis on reproductive outcomes is little understood. We report here that experimental epididymitis induced in rats by Gram-negative (LPS) and Gram-positive (LTA) bacterial products resulted in differential patterns of acute inflammation in the cauda epididymis. LPS elicited a strong inflammatory reaction, as reflected by upregulation of levels of mRNA for seven inflammatory mediators (Il1b, Tnf, Il6, Ifng, Il10, Nos2 and Nfkbia), and tissue concentration of six cytokines/chemokines (IL1A, IL1B, IL6, IL10, CXCL2 and CCL2) within the first 24 h post-treatment. Conversely, LTA induced downregulation of one (Nfkbia) and upregulation of six (Il1b, Il6, Nos2, Il4 Il10 and Ptgs1) inflammatory gene transcripts, whereas increased the tissue concentration of three cytokines/chemokines (IL10, CXCL2 and CCL2). The stronger acute inflammatory response induced by LPS correlated with a reduction of epididymal sperm count and transit time that occurred at 1, 7, and 15 days post-treatment. Our study provides evidence that early epididymal inflammatory signaling events to bacterial activators of innate immunity may contribute to the detrimental effects of epididymitis upon male fertility.

Liprin α3: a putative estrogen regulated acrosomal protein

Liprin α3 was reported for the first time using sperm proteomics. Present study reports its localization on sperm and immunochemical characterization. Liprin α3 is identified as a 133 kDa protein in testis and epididymal protein extracts. In testis, immunohistochemical localization was seen in pachytenes, diplotenes, round spermatids whereas it was localized in the epithelial cells and luminal sperm in all the three regions of epididymis. Protein was localized in acrosome of rat sperm, which was further confirmed by sequential treatment of sperm with hypertonic solution. In the spermatogenic cells the protein was found to be located in developing acrosome as evident by its co-localization with Golgi marker. Protein was found to be developmentally regulated. In silico analysis of Liprin α3 revealed presence of the estrogen responsive elements upstream to initiation site and its regulation by estrogen was experimentally validated using a tamoxifen treated rat model. Western blot analysis of epididymosomes showed the presence of Liprin α3, indicating its involvement in trafficking of vesicle. The protein expression was seen in both mouse and human sperm indicating conserved nature and a probable role in acrosome reaction.

Mono or bilateral inflammatory postmicrobial prostato-vesciculo-epididymitis: differences in semen parameters and reactive oxygen species production

AIM

The aim of this study was to analyse possible differences in sperm characteristics (including seminal leukocyte concentration, number of spermiophagies, and sperm reactive oxygen species [ROS] production) between patients with monolateral and bilateral prostate-vesciculo-epididymitis (PVE).

METHODS

Seventy-eight selected consecutively enrolled patients (mean age 34 years, range 24-40) with chronic inflammatory postmicrobial PVE and 30 infertile (aged-matched) patients (control group) with inflammatory postmicrobial prostatitis underwent sperm analysis, including seminal leukocyte concentration, number of spermiophages, and ROS production.

RESULTS

Sperm concentration and total sperm number were significantly lower in the patients with bilateral PVE than in those with monolateral PVE. The percentage of cases with oligozoospermia or hyperspermia was significantly higher among patients with bilateral PVE with than those with monolateral PVE. Although the remaining cytologic and physicochemical sperm characteristics and ROS production (both in 45% and 90% Percoll fractions) were not significantly different between the 2 PVE groups, both groups showed median and relative percentages of frequency of abnormal sperm characteristics worse than those in the control group.

CONCLUSIONS

Although sperm abnormalities (including seminal leukocyte concentration, number of spermiophages, and ROS production) can distinguish patients with PVE from those with prostatitis alone, the abnormalities did not discriminate between unilateral and bilateral PVE. In diagnostic suspicion of PVE, didymo-epididymal and prostato-vescicular ultrasonography can help discriminate monolateral from bilateral forms of PVE, and is a useful aid in the follow-up of these patients.

Oxidative and antioxidative status in the testes of rats with acute epididymitis

INTRODUCTION

Epididymitis is an inflammation or infection of the epididymis, a convoluted duct that lies on the posterior surface of the testicle. Oxidative stress due to excessive production of reactive oxygen species in epididymitis, impaired antioxidant defense mechanisms, or both, precipitates a range of pathologies that are currently believed to negatively affect the male reproductive function. How oxidative stress affects the testes is still unknown. We aimed to investigate the oxidative and antioxidative status of testes of rats with unilateral acute Escherichia coli epididymitis.

METHODS

The study included 36 male Wistar albino rats which were divided into three groups. In the epididymitis group (n = 12), an E. coli suspension was injected into the right ductus deferens of rats, and the same amount of saline was injected in the saline groups (n = 12). No surgery was performed in the control group (n = 12) for baseline values. Rats were sacrificed after 24 h and the epididymis and testes removed. The infection was confirmed by histopathologic evaluation and microbiological tests. The oxidative status of testes was evaluated by measuring myeloperoxidase (MPO) activity, and antioxidative status was evaluated by measuring total antioxidant response (TAR) and total antioxidant capacity levels (TAC).

RESULTS

MPO activity in both the ipsilateral and contralateral testes of the epididymitis group was significantly higher than those of the saline and control groups (p < 0.05). The TAR and TAC levels in both testes were also significantly elevated in the epididymitis group versus the two other groups (p < 0.05).

CONCLUSIONS

Acute epididymitis causes an increase of oxidative stress in the ipsilateral and contralateral testes, but this condition is strived for to tolerate the increase of endogenous antioxidants.

Soluble IL-6 receptor levels in the seminal plasma of infertile patients with accessory gland infection

The aim of this study was to confirm the presence of soluble interleukin-6 receptor (SIL-6R) in seminal plasma, to show eventual differences between SIL-6R concentrations in fertile and infertile men, and to evaluate the possible value of measuring these substances for the diagnosis of male accessory gland infection. SIL-6R levels were determined by "sandwich" enzyme immunoassay in the seminal plasma of 82 men divided into 7 groups according to the etiological diagnosis of fertility. The levels of SIL-6R in the seminal plasma of men with infection of the accessory genital glands were statistically significantly different in comparison with other groups (p < .001). The results suggest that urogenital infections may lead to elevated levels of SIL-6R in the seminal plasma. This measurement of SIL-6R in semen may provide clinically useful information for the diagnosis of male accessory gland infection.

The fatty acid composition of phospholipids of spermatozoa from infertile patients

The lipid composition of the sperm membrane has a significant effect upon the functional characteristics of spermatozoa. In the present study we investigated the fatty acid (FA) composition of subpopulations of spermatozoa separated on a discontinuous Percoll gradient (47:90%) and the FA composition of phospholipids (PL) of sperm heads and tails in both normal and abnormal semen samples. In normozoospermic samples, polyunsaturated fatty acids (PUFA) represented 34.0 +/- 1.3 (mean +/- SE, mole %) and 25.6 +/- 1.2% of total FA of PL of the 47 and 90% Percoll fractions respectively. Docosahexaenoic acid (22:6omega3, DHA) contributed to more than 60% of total PUFA. DHA was significantly lower in both the 47% (P < 0.05) and the 90% (P < 0.01) Percoll fractions of oligozoospermic samples and in the 90% Percoll layer of asthenozoospermic samples (P < 0.01), compared with normozoospermic samples. The omega6/omega3 ratio was significantly increased in both Percoll fractions of samples with oligozoospermia (47%, P < 0.001 and 90%, P < 0.001) or with asthenozoospermia (47%, P < 0.05 and 90%, P < 0.001) compared with normozoospermic samples. The oxidative potential index (OPI) of spermatozoa recovered from the 47% Percoll layer was significantly higher (P < 0.0001) than of those recovered from the 90% Percoll. Mean melting point (MMP), an index of membrane fluidity, was significantly lower in head than in tails (P < 0.01) of spermatozoa, and also in both the 47% (P < 0.01) and 90% (P < 0.001) Percoll fractions of normozoospermic samples in comparison with oligozoospermic samples. The MMP was significantly higher (P < 0.05) in samples of patients with idiopathic oligo/asthenozoospermia, varicocele, and male accessory gland infection (MAGI). These differences in FA composition of PL in subpopulations of human spermatozoa, and in their heads and tails may be related to sperm maturity and to differences in physiological function.

The relation between reactive oxygen species and cytokines in andrological patients with or without male accessory gland infection

The presence of various cytokines, namely hepatocyte growth factor (HGF), interleukin-1 receptor antagonist (IL-1 RA), and interleukins (IL-1 alpha, IL-6, and IL-8), as well as the production of reactive oxygen species (ROS) was investigated in seminal plasma of fertile and infertile patients in order to evaluate the possible value of measuring these substances for the diagnosis of male accessory gland infection, and to assess the possible relationship between oxidative stress and cytokines during leucocytospermia and male accessory gland infection (MAGI). Our findings indicate that all of the measured cytokines seem to be produced locally as well as by white blood cells (WBC) and that, due to the presence of higher numbers of WBC, accessory gland infection may exert a deleterious effect on sperm quality through the production of ROS and/or of particular cytokines such as IL-1 alpha, IL-1 RA, and IL-8. The most specific marker for a sensitivity of 95% in discriminating between cases with or without MAGI is the measurement of IL-6 in seminal plasma. In the absence of WBC several cytokines are constitutively produced and correlate with sperm concentration (HGF, IL-8), alpha-glucosidase (IL-6), and gamma-glutamyltransferase activity (HGF). The measurement of these cytokines in semen may provide clinically useful information for the diagnosis of male accessory gland infection, as well as in the absence of WBC where it can provide information about certain mechanisms of male reproductive function and dysfunction.

Antimicrobial tissue penetration in a rat model of E. coli epididymitis

Following induction of unilateral epididymitis by intratesticular injection of E. coli, a single intraperitoneal dose of amdinocillin, ampicillin, doxycycline, tobramycin, or trimethoprim/sulfamethoxazole was administered to five groups of rats. The animal was sacrificed serially and concentrations of antibiotic in serum, infected epididymides, and non-infected epididymides were determined by high performance liquid chromatography. The ratio of infected to non-infected tissue area under the curve values was 1.05 for trimethoprim, 1.58 for sulfamethoxazole, 1.67 for amdinocillin, 2.01 for tobramycin, 2.25 for doxycycline, and 2.58 for ampicillin. Except for trimethoprim, infected tissue concentrations were significantly greater than compared to uninfected epididymal levels (p less than 0.05). Antibiotic concentrations in infected epididymides compared to serum revealed overall penetration of 34% for amdinocillin, 66% for sulfamethoxazole, 70% for ampicillin, 76% for tobramycin, 256% for trimethoprim, and 257% for doxycycline. In a rat model of epididymitis, trimethoprim and doxycycline demonstrated the greatest degree of epididymal penetration compared to serum. All antibiotics except trimethoprim had significantly greater penetration into infected tissue when compared to non-infected epididymal tissue.

Experimental chlamydial epididymitis

Male Wistar rats were infected with the chlamydial agent of guinea pig inclusion conjunctivitis by inoculation of chlamydiae into the vas deferens. Epididymitis was observed in all infected animals clinically and histologically. Chlamydiae were detected in the epithelium of epididymal tubules by immunohistochemical staining (alkaline phosphatase anti-alkaline phosphatase technique). Inflammation progressed from the cauda to the corpus and caput epididymidis leading to fibrosis of the cauda epididymidis 28 days after infection. Animals responded to the infection with a rise of both serum IgM and IgG antibodies.

Association of seminal desethylamiodarone concentration and epididymitis with amiodarone treatment

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Features of a seminal proteinase inhibitor- zona pellucida-binding component on murine spermatozoa

Murine cauda epididymal sperm contain sites on the plasma membrane over the apical portion of the acrosome that recognize proteinase inhibitors and the homologous zona pellucida. Ten times more of the component can be extracted from cauda and ductus sperm than from equal numbers of caput and corpus sperm. Likewise, few sperm from the upper epididymal regions are able to bind seminal inhibitor, while the majority of sperm from the cauda and ductus do bind. Cauda epididymal and ductus sperm lose little of their ability to bind inhibitor after a 4-hour in vitro incubation in either a capacitating or a noncapacitating medium. The percentage of naturally inseminated sperm with the seminal inhibitor bound to their surface decreases to about 10 after 4 hours in utero. Approximately 80% of these sperm show positive fluorescence when given the opportunity to rebind the the inhibitor, and these sperm do have an intact plasma membrane over the apical portion of the acrosome. Furthermore, after 4 hours in utero, the inhibitor bound in the same region of the sperm head as it did on freshly ejaculated sperm. The seminal inhibitor inhibits the binding of sperm to the zona if added during the first 15 minutes of incubation but has no effect on attachment. The data indicate that sperm gain the ability to bind the seminal inhibitor during the epididymal sojourn. Furthermore, this binding capacity is not lost during in vitro or in utero incubation. The site is not involved in sperm-zona attachment but does participate in the binding of sperm to the zona.

[Effect of cefoperazone on acute prostatitis and epididymitis]

Cefoperazone (CPZ) was intravenously administered to rabbits and the concentration of CPZ in the accessory male genitals was determined. The epididymis, prostate and testicles had a high enough concentration of CPZ to kill various kinds of bacteria. Therefore, CPZ was applied to 11 clinical cases of acute epididymitis and 4 cases of acute prostatitis, but clinical effects were not so satisfactory in the cases of acute epididymitis.

The effects of vasectomy on the movement of 14C-urea in the seminiferous tubule of the hamster

14C-urea entry into the hamster seminiferous tubule (SNT) and cauda epididymidal tubule was observed in intact males and in animals vasectomized for 2 weeks and for 4 months. 14C-urea entry rate and plateau level were significantly increased 4 months postvasectomy. 14C-urea entry into the cauda epididymidis was significantly altered 2 weeks postvasectomy. 2, 4,-dinitrophenol significantly increased 14C-urea concentration in the SNT. This is compatible with the presence of an outward directed energy dependent movement of urea in the hamster SNT. Increasing 14C-urea concentrations in the postvasectomy SNT may be attributable to a failure or inhibition of this physiologic activity.

Epididymis and seminal vesicle as sources of carnitine in human seminal fluid: the clinical significance of the carnitine concentration in human seminal fluid

Carnitine determinations in human seminal fluid were shown to be useful in assessing epididymal and seminal vesicle function and in locating blockages in the male reproductive tract. The carnitine concentrations in 50 samples of seminal fluid ranged from 15 to 530 mug/ml (as carnitine-HCl). The patients could be divided into four classes. Patients with normal seminal vesicle and epididymal function had values of 250 mug/ml or above. Those with a defective epididymis and a functional seminal vesicle had intermediate carnitine levels (100 to 200 mug/ml) and normal fructose values in the seminal fluid. Patients with a defective seminal vesicle but a functional epididymis had intermediate carnitine concentrations and low fructose levels. Extremely low carnitine values (less than 100 mug/ml) were found in seminal fluid from patients whose epididymis and seminal vesicle both were defective. The possible role of carnitine in sperm maturation was discussed.