Demonstration of a glycoprotein derived from the Ceacam10 gene in mouse seminal vesicle secretions

CEACAM10 was purified from mouse seminal vesicle secretions by a series of purification steps that included ion exchange chromatography on a DEAE-Sephacel column and ion exchange high-performance liquid chromatography on a sulfopropyl column. It was shown to be a 36-kDa glycoprotein with an N-linked carbohydrate moiety. The circular dichromoism spectrum of CEACAM10 in 50 mM phosphate buffer at pH 7.4 appeared as one negative band arising from the beta form at 217 nm. CEACAM10 was expressed predominantly in seminal vesicles of adult mice. Both CEACAM10 and its mRNA were demonstrated on the luminal epithelium of the mucosal folds in the seminal vesicle. The amount of Ceacam10 mRNA in the seminal vesicle was correlated with the stage of animal maturation. Castration of adult mice resulted in cessation of Ceacam10 expression, while treatment of castrated mice with testosterone propionate in corn oil restored Ceacam10 expression in the seminal vesicle. During the entire course of pregnancy, Ceacam10 might be silent in the embryo. A cytochemical study illustrated the presence of the CEACAM10 binding region on the entire surface of mouse sperm. CEACAM10-sperm binding greatly enhanced sperm motility in vitro.     

Induction of functional cytodifferentiation in the epithelium of tissue recombinants. I. Homotypic seminal vesicle recombinants

Functional cytodifferentiation of seminal vesicle epithelium was investigated in tissue recombinants. Neonatal rat and mouse seminal vesicles were separated into epithelium and mesenchyme using trypsin. Epithelium and mesenchyme were then recombined in vitro to form interspecific rat/mouse homotypic recombinants. Growth as renal grafts in adult male athymic mice resulted in seminal vesicle morphogenesis in 70% of the recombinants (the remaining 30% failed to grow). Functional cytodifferentiation was judged by the expression of the major androgen-dependent secretory proteins characteristic of the seminal vesicles of adult rats and mice. Antibodies specific for each of these proteins were used to screen tissue sections by immunocytochemistry and to probe protein extracts by immunoblotting techniques. The heterospecific recombinants synthesized the full range of seminal vesicle secretory proteins that typifies the species providing the epithelium of the recombinant, not the mesenchyme. There was little functional variation between individual recombinants. The time course of development corresponded to that of intact neonatal seminal vesicles grown under the same conditions. Morphogenesis and functional cytodifferentiation were not evident after one week, but were well advanced after two weeks. Seminal vesicle recombinants grown for three weeks were indistinguishable morphologically and functionally from normal adult seminal vesicles. In addition, the ability of adult seminal vesicle epithelium to be induced to proliferate was examined. In association with neonatal seminal vesicle mesenchyme, the epithelium of the adult seminal vesicle proliferated and retained its normal functional activity. Thus, seminal vesicle functional cytodifferentiation can be faithfully reproduced in homotypic tissue recombinants. The methods used in this study will be used to investigate seminal vesicle development in instructive inductions of heterotypic epithelia.     

Paramount levels of ergothioneine transporter SLC22A4 mRNA in boar seminal vesicles and cross-species analysis of ergothioneine and glutathione in seminal plasma

Ergothioneine (ET) is a unique natural antioxidant which mammalia acquire exclusively from their food. Recently, we have discovered an ET transporter (ETT; gene symbol SLC22A4). The existence of a specific transporter suggests a beneficial role for ET; however, the precise physiological purpose of ET is still unclear. A conspicuous site of high extracellular ET accumulation is boar seminal plasma. Here, we have investigated whether ETT is responsible for specific accumulation of ET in the boar reproductive tract. The putative ETT from pig (ETTp) was cloned and validated by functional expression in 293 cells. The highest levels of ETTp mRNA were detected by real-time RT-PCR in seminal vesicles, eye, and kidney; much less was present in bulbourethral gland, testis, and prostate. By contrast, there was virtually no ETT mRNA in rat seminal vesicles. ET content in boar reproductive tissues, determined by LC-MS/MS, closely matched the ETT expression profile. Thus, strong and specific expression of ETTp in boar seminal vesicles explains high accumulation of ET in this gland and hence also in seminal plasma. Previous reports suggest that the glutathione (GSH) content of seminal plasma correlates directly with ET content; however, a comprehensive analysis across several species is not available. We have measured ET and GSH in seminal plasma from human, boar, bull, stallion, and rabbit by LC-MS/MS. GSH levels in seminal plasma do not correlate with ET levels. This suggests that the function of ET, at least in this extracellular context, does not depend on redox cycling with GSH.     

ProCNP and CNP are expressed primarily in male genital organs

Lack of knowledge about the cellular origin of C-type natriuretic peptides (CNP) in the body has hampered the understanding of their biology. We examined the tissue specific expression of proCNP and CNP in the pig. The concentration of the CNP precursor, proCNP, was measured in extracts of 32 different tissues using a newly developed RIA. In 22 tissue extracts, we also measured CNP using a commercial RIA. In selected tissues, CNP mRNA was quantified by PCR, and the cellular CNP and proCNP localization was visualized by immunocytochemistry. Extracts from selected tissues were examined by gel chromatography. The highest peptide concentrations were found in extracts from the epididymis, seminal vesicles and prostate. CNP mRNA in the seminal vesicles and epididymis was 125-fold higher than in the other tissues examined. Gel chromatography showed that a CNP-53-like peptide is the dominant CNP tissue-form. Immunocytochemistry confirmed the pattern of peptide expression measured by RIA. In conclusion most proCNP-derived peptides are synthesized in epithelial cells in the epididymis, the prostate gland and in the seminal vesicles. The expression in male genital organs suggests a role of CNP in reproduction.     

In vivo function of airway epithelial TLR2 in host defense against bacterial infection

Decreased Toll-like receptor 2 (TLR2) expression has been reported in patients with chronic obstructive pulmonary disease and in a murine asthma model, which may predispose the hosts to bacterial infections, leading to disease exacerbations. Since airway epithelial cells serve as the first line of respiratory mucosal defense, the present study aimed to reveal the role of airway epithelial TLR2 signaling to lung bacterial [i.e., Mycoplasma pneumoniae (Mp)] clearance. In vivo TLR2 gene transfer via intranasal inoculation of adenoviral vector was performed to reconstitute TLR2 expression in airway epithelium of TLR2(-/-) BALB/c mice, with or without ensuing Mp infection. TLR2 and lactotransferrin (LTF) expression in airway epithelial cells and lung Mp load were assessed. Adenovirus-mediated TLR2 gene transfer to airway epithelial cells of TLR2(-/-) mice reconstituted 30-40% TLR2 expression compared with TLR2(+/+) cells. Such airway epithelial TLR2 reconstitution in TLR2(-/-) mice significantly reduced lung Mp load (an appropriate 45% reduction), coupled with elevated LTF expression. LTF expression in mice was shown to be mainly dependent on TLR2 signaling in response to Mp infection. Exogenous human LTF protein dose-dependently decreased lung bacterial load in Mp-infected TLR2(-/-) mice. In addition, human LTF protein directly dose-dependently decreased Mp levels in vitro. These data indicate that reconstitution of airway epithelial TLR2 signaling in TLR2(-/-) mice significantly restores lung defense against bacteria (e.g., Mp) via increased lung antimicrobial protein LTF production. Our findings may offer a deliverable approach to attenuate bacterial infections in airways of asthma or chronic obstructive pulmonary disease patients with impaired TLR2 function.     

Effect of antiandrogen cyproterone acetate on the action of testosterone on mouse kidney.

The loss of endogenous testosterone in castrated male mice leads to a marked decrease in seminal vesicle and kidney tissue weight. 21 days' administration of exogenous testosterone abolished the effect of castration on the seminal vesicles and kidney tissue. The antiandrogen cyproterone acetate produced significant changes in the target tissue for androgens, i.e. in the seminal vesicles. In every case it blocked the action of both exogenous and endogenous testosterone on the seminal vesicles, but failed to block the "renotropic" action of testosterone, expressed as relative kidney weight. Contrary to its effect on the seminal vesicles, it did not influence relative kidney weight in normal animals. It likewise did not block the effect of exogenous testosterone on kidney tissue. The mechanism of the action of cyproterone acetate in androgen-dependent tissues is known to consist in inhibition of androgen binding to specific cell receptors in the target tissues. Some of the specific androgen receptors in mouse kidney are evidently different in character from those in the accessary sex glands, that being the reason why cyproterone acetate has an antiandrogenic, but not an antirenotropic effect. In agreement with experiments on rats, adrenal weight also decreases in mice after the administration of cyproterone acetate.     

Role of neutrophils in matrix metalloproteinase activity in the preimplantation mouse uterus

Matrix metalloproteinases (MMPs) have been implicated in embryonal implantation processes such as trophoblast invasion and decidualization. The temporal and spatial distributions of MMP bioactivities were analyzed by in situ zymography, which indicated these activities to be markedly increased in the postcoital mouse uterus compared with those in the later implantation stage. Activity was ascribed to proMMP9, which moved from the uterine serosa to the endometrium but was not associated with mRNA up-regulation. The activity was colocalized with infiltrating neutrophils, and neutropenic mice did not exhibit MMP9 expression. Removing the seminal vesicles from male mice abolished the postcoital increase in MMP9 in the female. These results indicate the major MMP activity in the preimplantation uterus to originate in proMMP9-bearing neutrophils attracted by seminal plasma. Considering our results together with those of previous reports of reduced fertility in Mmp9-deficient female mice, we speculate that neutrophil infiltration participates in the extracellular matrix degradation needed to support pregnancy.     

Epididymal dysfunction initiated by the expression of simian virus 40 T-antigen leads to angulated sperm flagella and infertility in transgenic mice

We have generated two transgenic mouse lines (GPX5-Tag1 and GPX5-Tag2) by expressing the Simian virus 40 large and small T-antigens under a 5-kb promoter of the murine glutathione peroxidase 5 (GPX5) gene. In GPX5-Tag1 mice, with a high level of T-antigen expression, severe dysplasia was found in the epididymis and seminal vesicles. These mice also developed adrenal and prostate tumors, and spermatogenesis was disrupted. In GPX5-Tag2 mice, with a lower level of T-antigen expression, the only histological change was the slightly hyperplastic epithelium in the initial segment of the epididymidis and in the seminal vesicles. Despite normal mating behavior, these mice were infertile. The most conspicuous feature of the sperm was angulation of the flagellum, which appeared during epididymal transit, probably due to the observed reduction in the osmotic pressure of cauda epididymidal fluid. The angulation did not affect the motility or kinematic parameters of the sperm, but the sperm were also incapable of fertilization in vitro. The lack of expression of several genes specific for the initial segment suggests that in the GPX5-Tag2 mice the transgene expression brings about a differentiation arrest in this part of epididymis. This novel mouse line provides a model for epididymal dysfunction leading to defects in posttesticular sperm maturation and infertility.     

Increase in epithelial cell growth by hyperprolactinemia induces delay of castration-induced involution of mouse seminal vesicle

Male (C57BL/6 x DBA)F1 hybrid mice were castrated on day 60 after birth; two pituitaries from 60-day-old female mice were immediately grafted under the capsule of the left kidney in half of the castrated mice to induce hyperprolactinemia. The seminal vesicles in the absence of androgen treatment were examined 15, 22, 30 and 60 days after castration with or without grafting. Significant increases in the weight (1.3-1.4-fold), DNA content (1.2-1.3-fold) and labeling index of epithelial cells (4-10-fold) of the seminal vesicles were found in mice with pituitary grafts compared to mice without grafts on days 15-30 after castration but not on day 60 after castration. Such stimulatory effects of hyperprolactinemia on mouse seminal vesicle cells were also observed on day 15 after castration plus adrenalectomy. Cell loss from the seminal vesicles was found to be similar in castrated mice with and without the grafts. The present findings demonstrate that hyperprolactinemia induces an increase in DNA synthesis of epithelial cells in the seminal vesicles until 30 days after castration and results in a significant delay of castration-induced involution of the weight and DNA content of the seminal vesicles for 1 month. However, the delay with increased epithelial cell growth by hyperprolactinemia disappeared 60 days after castration.     

cDNA cloning of androgen-repressed mRNA in rat seminal vesicles: partial characterization of a cDNA clone, pSvr-1

When the in vitro translation products of mRNAs from castrated animals (48 h) were compared with those from androgen-treated animals (48 h) to survey the molecular mechanism of androgen-responsive gene expressions in the rat seminal vesicles, some peptide bands which were repressed in response to androgen were observed. From these findings, we constructed a partial cDNA library of poly(A+)RNAs which had been isolated from the seminal vesicles of castrated rats (48 h) and modestly enriched with respect to the concentration of androgen-repressed mRNAs by sucrose density gradient centrifugation, and screened by differential colony hybridization. One cDNA clone, pSvr-1, whose mRNA is markedly induced within 24 h after castration of the animal in the seminal vesicles as well as in the ventral prostate, was isolated. pSvr-1 hybridized to a mRNA of 1,700 nucleotides in length. Partial sequence analysis showed that this clone had highly homologous but not identical sequences to those reported for rat sulfated glycoprotein-2. This cDNA clone may provide a useful probe for the study of the negative regulation mechanism of gene expression by androgens.     

Adaptation to hypobaric hypoxia involves GABA A receptors in the pons

Survival in low-oxygen environments requires adaptation of sympathorespiratory control networks located in the brain stem. The molecular mechanisms underlying adaptation are unclear. In na?ve animals, acute hypoxia evokes increases in phrenic (respiratory) and splanchnic (sympathetic) nerve activities that persist after repeated challenges (long-term facilitation, LTF). In contrast, our studies show that conditioning rats to chronic hypobaric hypoxia (CHH), an environment characteristic of living at high altitude, diminishes the response to hypoxia and attenuates LTF in a time-dependent manner. Phrenic LTF decreases following 7 days of CHH, and both sympathetic and phrenic LTF disappear following 14 days of CHH. Previous studies demonstrated that GABA is released in the brain stem during hypoxia and depresses respiratory activity. Furthermore, the sensitivity of brain stem neurons to GABA is increased following prolonged hypoxia. In this study, we demonstrate that GABA(A) receptor expression changes along with the CHH-induced physiological changes. Expression of the GABA(A) receptor alpha4 subunit mRNA increases two-fold in animals conditioned to CHH for 7 days. In addition, de novo expression of delta and alpha6, a subunit normally found exclusively in the cerebellum, is observed after 14 days. Consistent with these changes, diazepam-insensitive binding sites, characteristic of GABA(A) receptors containing alpha4 and alpha6 subunits, increase in the pons. Immunohistochemistry revealed that CHH-induced GABA(A) receptor subunit expression is localized in regions of sympathorespiratory control within the pons. Our findings suggest that a GABA(A) receptor mediated-mechanism participates in adaptation of the sympathorespiratory system to hypobaric hypoxia.     

The role of the seminal vesicles, coagulating glands and prostate glands on the fertility and fecundity of mice.

Female mice were allowed to mate with males which had been sham-operated (Group 1); had seminal vesicles, coagulating glands and ventral and dorsal prostate glands removed (Group 2); had the seminal vesicles removed (Group 3); had the coagulating glands removed (Group 4) or had the ventral and dorsal prostate gland removed (Group 5). The pregnancy rate was normal in Groups 1 and 4, severely reduced in Groups 2 and 3 and less so in Group 5. Litter size was reduced in Groups 2 and 3 but not in Group 5. It is suggested that the seminal vesicles and possibly the prostate glands are important in the production of young in mice.     

Lactoferrin gene knockdown leads to similar effects to iron chelation in human adipocytes

In human and mice adipose tissue, lactoferrin (LTF) has been found to be associated with increased adipogenesis and decreased inflammatory markers. Here, we aimed to investigate the effects of LTF knockdown (KD) in human adipocyte differentiation. In addition, the effects of exogenous LTF administration and iron chelation [using deferoxamine (DFO, 10 μM)] were tested. In both subcutaneous and visceral pre‐adipocytes, LTF KD led to decrease significantly adipogenic, lipogenic and insulin signalling‐related gene expression and a significant increase in the gene expression of inflammatory mediators. Human lactoferrin (hLf, 1 μM) administration led to recover adipocyte differentiation in LTF KD pre‐adipocytes. Interestingly, iron chelation triggered similar effects to LTF KD, decreasing significantly adipogenic gene expressions. Of note, DFO (10 μM) and hLf (1 and 10 μM) co‐administration led to a dose‐dependent recovery of adipocyte differentiation. These new data reveal that endogenous LTF biosynthesis during human adipocyte differentiation is essential to achieve this process, possibly, modulating adipocyte iron homoeostasis. hLf administration might be a useful therapeutic target in obesity‐associated adipose tissue dysfunction.     

Antiandrogenic and antirenotropic effect of spironolactone.

Spironolactone given to male mice in dose 1.5 mg for 21 days produced significant changes not only in the highly androgen dependent seminal vesicles but also in the kidneys. Spironolactone blocked the action of endogenous testosterone in intact mice and led to further significant decrease in seminal vesicles and kidney weight in castrated mice. Such an effect could be due to a blocking of androgenic action of adrenal steroids.     

Adrenalectomy and Castration in the Genetically Obese (OB/OB) Mouse

The present studies have tested the hypothesis that adrenalectomy could modify the phenotypic expression of genetic obesity by examining the effects of adrenalectomy on the function of the gonadal system in lean and ob/ob mice. Corticosterone concentrations were undetectable in the adrenalectomized animals. Adrenalectomy significantly slowed the weight gain of obese mice in comparison to sham-adrenalectomized controls. Gonadectomy had no independent effect on weight gain. The testes, prostate, and seminal vesicles in the ob/ob mice were significantly smaller than in the lean animals. Castration lowered the weights of the prostate and seminal vesicles in the lean mice to weights close to those observed in the castrated ob/ob mice. Castration significantly increased the concentrations of LH and FSH in both ob/ob and lean mice, but the absolute concentrations were higher in the lean mice in both conditions. Adrenalectomy per se had no effect on the concentration of LH, FSH, or testosterone or on the weights of the prostate or seminal vesicles. These data indicate that adrenalectomy has no effect on the physiologic control of the reproductive system in genetically obese mice, and are consistent with the hypothesis that the defect in the ob/ob mouse is a modulator of steroid action which over expresses glucocorticoid effects and under expresses gonadal steroid effects.     

Characterization of an eppin protein complex from human semen and spermatozoa

Eppin (SPINLW1; serine peptidase inhibitor-like with Kunitz and WAP domains 1 (eppin); epididymal protease inhibitor) coats the surface of human ejaculate spermatozoa and originates from Sertoli and epididymal epithelial cells. In this study, we have isolated native eppin from ejaculate supernatants (seminal plasma) and washed ejaculate spermatozoa using column chromatography and two-dimensional SDS-PAGE, and identified by mass spectrometry and Western blots an eppin protein complex (EPC) containing lactotransferrin (LTF; also known as lactoferrin), clusterin (CLU), and semenogelin (SEMG1). To confirm the association of eppin with LTF, CLU, and SEMG1, antibodies to CLU and LTF were used to immunoprecipitate CLU and LTF from human sperm lysates. In both cases identical results were obtained, namely, the immunoprecipitate of the EPC. Additionally, we localized eppin, LTF, and CLU in human Sertoli cells and on human testicular and ejaculate spermatozoa, implying that the EPC is present on spermatozoa from the time they leave the seminiferous tubule. On ejaculate spermatozoa eppin, LTF, and CLU colocalize on the tail. The identification of the EPC components suggests that LTF, CLU, and/or eppin receptors may function as sperm plasma membrane receptors for the EPC, implicating the complex as a central player in a network of protein-protein interactions on the human sperm surface. The EPC may provide a surface network with microbicidal properties that protects spermatozoa as well as regulates the sperm's transition to a motile, capacitated sperm.     

Protease-nexin I as an androgen-dependent secretory product of the murine seminal vesicle.

A search for inhibitors of urokinase-type plasminogen activator (uPA) in the male and female murine genital tracts revealed high levels of a uPA ligand in the seminal vesicle. This ligand is functionally, biochemically and immunologically indistinguishable from protease-nexin I (PN-I), a serpin ligand of thrombin and uPA previously detected only in mesenchymal cells and astrocytes. A survey of murine tissues indicates that PN-I mRNA is most abundant in seminal vesicles, where it represents 0.2-0.4% of the mRNAs. PN-I is synthesized in the epithelium of the seminal vesicle, as determined by in situ hybridization, and is secreted in the lumen of the gland. PN-I levels are much lower in immature animals, and strongly decreased upon castration. Testosterone treatment of castrated males rapidly restores PN-I mRNA levels, indicating that PN-I gene expression is under androgen control.