Human Male Reproductive Tract Research Articles

A novel murine model mimicking male genital Neisseria species infection using Neisseria musculi†.

With ~78 million cases yearly, the sexually transmitted bacterium Neisseria gonorrhoeae is an urgent threat to global public health due to continued emergence of antimicrobial resistance. In the male reproductive tract, untreated infections may cause permanent damage, poor sperm quality, and subsequently subfertility. Currently, few animal models exist for N. gonorrhoeae infection, which has strict human tropism, and available models have limited translatability to human disease. The absence of appropriate models inhibits the development of vital new diagnostics and treatments. However, the discovery of Neisseria musculi, a mouse oral cavity bacterium, offers much promise. This bacterium has already been used to develop an oral Neisseria infection model, but the feasibility of establishing urogenital gonococcal models is unexplored. We inoculated mice via the intrapenile route with N. musculi. We assessed bacterial burden throughout the male reproductive tract, the systemic and tissue-specific immune response 2-weeks postinfection, and the effect of infection on sperm health. Neisseria musculi was found in penis (2/5) and vas deferens (3/5) tissues. Infection altered immune cell counts: CD19+ (spleen, lymph node, penis), F4/80+ (spleen, lymph node, epididymus), and Gr1+ (penis) compared with noninfected mice. This culminated in sperm from infected mice having poor viability, motility, and morphology. We hypothesize that in the absence of testis infection, infection and inflammation in other reproductive is sufficient to damage sperm quality. Many results herein are consistent with outcomes of gonorrhoea infection, indicating the potential of this model as a tool for enhancing the understanding of Neisseria infections of the human male reproductive tract.

Expression of NELL2/NICOL-ROS1 lumicrine signaling-related molecules in the human male reproductive tract.

The maturation of spermatozoa is a regulated process, influenced by genes expressing essential secreted proteins in the proximal epididymis. Recent genetic studies in rodents have identified the non-sex steroidal molecular signals that regulate gene expression in the proximal epididymis. Germ cells in the testis secrete ligand proteins into the seminiferous tubule lumen The ligand proteins travel through the male reproductive tract lumen to the epididymis, where they bind to receptors, triggering the differentiation of the luminal epithelium for sperm maturation. It is, however, not fully unveiled if such a testis-epididymis trans-luminal signaling mechanism exists in other species, especially humans. In the present study, the rodent-type testis-epididymis trans-luminal signaling in the human male reproductive tract was evaluated in a step-by-step manner by analyzing testis and epididymis gene expression and signaling mediator protein function. There was a significant correlation between the epididymal expressions of mouse genes upregulated by the trans-luminal signaling and those of their human orthologs, as evaluated by the correlation coefficient of 0.604. The transcript expression of NELL2 and NICOL encoding putative ligand proteins was also observed in human testicular cells. In vitro experiments demonstrated that purified recombinant human NELL2 and NICOL formed a molecular complex with similar properties to rodent proteins, which was evaluated by a dissociation equilibrium constant of 110 nM. Recombinant human NELL2 also specifically bound to its putative receptor human ROS1 in vitro. Collectively, these findings suggest that the rodent-type testis-epididymis secreted signaling mechanism is also possible in the human male reproductive tract.

Vitamin D levels and human sperm DNA fragmentation: a prospective, cohort study

BackgroundIntracytoplasmic sperm injection (ICSI) has revolutionized the treatment of couples with male factor infertility but results remain suboptimal and suggest the need for further investigation into the molecular biology of spermatozoa. Vitamin D has been implicated in spermatogenesis and sperm function. Hypovitaminosis D has been associated with abnormal testicular function, including elevated sperm DNA fragmentation in a murine model. This study’s objective was to evaluate if there is a correlation between Vitamin D sufficiency and human spermatozoa DNA fragmentation index % (DFI%) in infertile couples.ResultsA prospective cohort study using a consecutive, convenience sample of subjects with infertility. The primary endpoint was the effect of Vitamin D sufficiency on human spermatozoa DFI%, and secondary outcomes included Vitamin D’s effect on moderate DFI%, high DFI%, High DNA stainability % (HDS%), sperm density (million/mL), sperm total motility (% total) and sperm strict morphology (% total). Of the 111 participating, 9 were excluded, leaving 102subjects. The subjects were stratified by vitamin D levels: deficient (< 20 ng/mL; n = 24), insufficient (20–30 ng/mL; n = 43),, and sufficient (> 30 ng/mL; n = 35). There were no statistical difference between the categories of serum vitamin D levels and sperm DFI% as well as the secondary outcomes. An increased BMI was associated with low serum vitamin D levels (p = 0.0012).ConclusionVitamin D deficiency was not associated with sperm DFI% or routine sperm parameters. Previous animal and human studies have demonstrated conflicting results between sperm parameters and Vitamin D levels. Redundant pathways in Vitamin D and calcium homeostasis in the human male reproductive tract may maintain essential reproductive processes during Vitamin D insufficiency or deficiency.Trial registrationTrial Registration Number: MOD00002311 (ClinicalTrials.gov).

Association Between Prolonged Shedding of Zika Virus in Human Semen and Male Reproductive Tract Inflammation.

Zika virus (ZIKV) is a mosquito-borne flavivirus that causes congenital defects. Sexual transmission of ZIKV was confirmed in a recent epidemic; however, mechanisms behind ZIKV infection and persistence in the male reproductive tract (MRT) are unknown. Previously, we found that approximately 33% of men with symptomatic ZIKV infections shed ZIKV RNA in semen, and some men shed ZIKV RNA for >3 months. Here, we evaluated the semen of 49 ZIKV-infected men to identify immune factors correlating with long-term ZIKV shedding in semen and ZIKV-infected cell types in semen. We found that prolonged ZIKV RNA shedding in semen was associated with MRT inflammation, indicated by higher leukocyte counts and inflammatory cytokine concentrations in semen of long-term versus short-term shedders. In addition, we found ZIKV RNA in seminal leukocytes and epithelial cells. This study of human semen from ZIKV-infected men provides critical insights into the effects of ZIKV on MRT health.

Heat transfer analysis of biological nanofluid flow through ductus efferentes

A theoretical investigation on heat transfer of nanofluid transport in a ciliated channel is presented. A mathematical model for cilia oriented nanofluid transport through the human male reproductive tract is exhibited. Considering the structure of tubules, the Reynolds number is considered very small. The concept of a long wavelength approximation is incorporated to model the nanofluid flow problem. The exact analytical expressions for the x-component of velocity, temperature, nanoparticle concentration, stream function, volume flow rate, and pressure gradient are calculated. The solution for the transverse component of velocity, pressure rise per wavelength, and friction force on the wall of the channel is explored numerically, while variations in crucial flow parameters are examined graphically.

Analysis of MHD and heat transfer effects with variable viscosity through ductus efferentes

A novel theoretical model for unsteady, non-isothermal flow with temperature variant viscosity for the Newtonian fluid in the presence of transverse magnetic field is studied in the ductus efferentes of human male reproductive tract. Importance of cilia for the fluid transport through ductus efferente is elaborated in this study. To investigate the flow, we considered a channel and constant temperature difference is imposed between the wall of channel. A mathematical model is developed and analytical solution is achieved with the help of Adomian decomposition method (ADM) for MHD heat and fluid flow with temperature dependent viscosity. Flow is modeled by considering assumptions that Reynolds number is small, so that inertial forces are insignificant and wavelength to diameter ratio is maximum, so that pressure can be assumed uniform in the channel. Solutions are presented for the exponential dependent viscosity on temperature. Effect of different flow parameters on the axial and transverse component of velocity are analyzed graphically. Pumping characteristic due to ciliary beat from one row of cilia to another are investigated. Lastly variation of different flow parameters on the trapped bolus and pressure are examined graphically.

Zika Virus Trafficking and Interactions in the Human Male Reproductive Tract.

Sexual transmission of Zika virus (ZIKV) is a matter of great concern. Infectious viral particles can be shed in semen for as long as six months after infection and can be transferred to male and female sexual partners during unprotected sexual intercourse. The virus can be found inside spermatozoa and could be directly transferred to the oocyte during fertilization. Sexual transmission of ZIKV can contribute to the rise in number of infected individuals in endemic areas as well as in countries where the mosquito vector does not thrive. There is also the possibility, as has been demonstrated in mouse models, that the vaginal deposition of ZIKV particles present in semen could lead to congenital syndrome. In this paper, we review the current literature to understand ZIKV trafficking from the bloodstream to the human male reproductive tract and viral interactions with host cells in interstitial spaces, tubule walls, annexed glands and semen. We hope to highlight gaps to be filled by future research and potential routes for vaccine and antiviral development.

X-ray diffraction study on human male reproductive tract and semen.

In the present study authors had separated testis, epididymis-caput, corpus, cauda, vas deferens, seminal vesicle, prostate gland and bulbourethral gland from human male reproductive tract, made it...

Long-term kinetics of Zika virus RNA and antibodies in body fluids of a vasectomized traveller returning from Martinique: a case report

BackgroundThe magnitude of the current Zika virus (ZIKV) epidemic has led to a declaration of a Public Health Emergency of International Concern by the WHO. Findings of viable viral particles in semen for several weeks are corroborating reports of sexual transmission of ZIKV. Serious consequences of a positive diagnostic result particularly in the pregnant patient are calling for precise diagnostic tools also at later time points after infection. Currently, recommendations suggest a diagnostic period of direct viral detection of 5 to 7 days after onset of symptoms in serum or plasma, and up to 3 weeks in urine samples.Case presentationA vasectomized 41-year-old German returning from Martinique presented at the outpatient clinic of the Department for Infectious Diseases and Tropical Medicine, Munich, with subfebrile temperature, rash, malaise, severe retro-orbital pain and occipital lymphadenopathy. The main complaints resolved after ten days without specific treatment. We are reporting on clinical course and results of direct and indirect detection methods of ZIKV in different sample types including whole blood, ejaculate, urine, serum, plasma and saliva samples up to 119 days post symptom onset. Ejaculate samples remained PCR positive for ZIKV until day 77, whole blood samples until day 101.ConclusionsThe case presentation adds to the still limited knowledge of kinetics of detection of ZIKV by direct as well as indirect methods. Here, a complete data set including results from PCR, serology and cell culture is provided allowing an improved evaluation of optimum diagnostic periods for testing a variety of sample types. Moreover, a high viral load of ZIKV RNA was detected in ejaculate of the vasectomized patient. This finding sheds new light on the possible localizations of ZIKV replication in the human male reproductive tract.

Hepatocytes cocultured with Sertoli cells in bioreactor favors Sertoli barrier tightness in rat.

The lack of a reliable in vitro system to assess reprotoxicity is an emerging problem in the context of European law for Registration, Evaluation, Authorization and Restriction of Chemicals (REACH, 2007), as it requires a reduction in animal utilization for testing. Furthermore, in vitro reprotoxicological tests would be more relevant and greatly improved by integrating both hepatic metabolism and the blood-testis barrier. Here, we took advantage of an integrated insert in a dynamic microfluidic platform (IIDMP) to co-cultivate hepatocytes in biochip and Sertoli cells in the bicameral chamber. This microfluidic tool has been previously demonstrated to be helpful in cell function and/or quality improvement. We demonstrate that permeability of the Sertoli barrier is reduced by dynamic coculture in our system. Exometabolomics analysis reveals that interactions between hepatocytes and Sertoli cells may have been mediated by the polyamines increase and/or mid-chain fatty acid decrease in the circulating medium. These metabolic changes may be involved in permeability reduction by contributing to modifying junction protein quantity and localization. The present study gives an example of IIDMP as an in vitro partitioning/transport model for cell culture and toxicological testing. Further, based on both our previous results using an intestinal-hepatic cell coculture and the present study, IIDMP seems to be well-suited for (i) assessing the dose-response effect of chemicals within the rodent or human male reproductive tract, and (ii) improving the quality of reprotoxicological assays by including hepatic metabolism. Copyright © 2016 John Wiley & Sons, Ltd.

Role of Vitamin D Deficiency in Male Fertility

Vitamin D deficiency is associated with suboptimal health. Data from the 2001-2004 National Health and Nutrition Examination Survey showed that nearly 75% of Americans have vitamin D insufficiency(1). In addition to maintenance of bone health, vitamin D also has a role in cell differentiation and inhibition of cell growth(2). Studies of human male reproductive tract revealed presence of the vitamin D receptor suggesting that vitamin D is important for spermatogenesis(3). Few clinical studies published to date address the possible association between vitamin D deficiency and male infertility(4).

A mathematical model for the flow of a Casson fluid due to metachronal beating of cilia in a tube.

A mathematical model is developed to study the transport mechanism of a Casson fluid flow inspired by the metachronal coordination between the beating cilia in a cylindrical tube. A two-dimensional system of nonlinear equations governing the flow problem is formulated by using axisymmetric cylindrical coordinates and then simplified by employing the long wavelength and low Reynolds number assumptions. Exact solutions are derived for the velocity components, the axial pressure gradient, and the stream function. However, the expressions for the pressure rise and the volume flow rate are evaluated numerically. The features of the flow characteristics such as pumping and trapping are illustrated and discussed with the help of graphs. It is observed that the volume flow rate is influenced significantly by the width of plug flow region H p as well as the cilia length parameter ε. The analysis is also applied and compared with the estimated value of the volume flow rate of epididymal fluid in the ductus efferentes of the human male reproductive tract.

Sperm protection in the male reproductive tract by Toll-like receptors

Sperm function can be affected by infection. Our understanding of innate immune system molecular mechanisms has been expanded, by the discovery of 'Toll-like receptors' (TLRs). It seems that these receptors could play a critical role in the protection of spermatozoa. This study seeks to examine the presence and distribution of TLRs in different parts of the human male reproductive tract and spermatozoa. So, TLR gene expression was examined by RT-PCR. Quantitative real-time PCR (Q-PCR) analysis used to compare the expression of TLRs in all sections of the male reproductive tract and TLRs 2, 3 and 4 in testicular sperm extraction (TESE) samples, which contained spermatozoa (TESE+) and those that did not (TESE-). Results showed that all TLR genes were expressed in different parts of the human male reproductive tract and spermatozoa. Moreover, Q-PCR indicated that the relative expression of TLRs did not significantly change in different parts of the male reproductive tract but this technique has shown only relative TLR2 expression in TESE- is lower than TESE+ samples. It could be concluded that TLRs may provide a broad spectrum of protection from infection in the male reproductive tract. Furthermore, TLRs may influence on the developmental process during spermatogenesis.

Seminal plasma adipokine levels are correlated with functional characteristics of spermatozoa

To study adipokines as a potential link between obesity and male subfertility. Cross-sectional study of subjects stratified into subgroups according to body mass index (BMI): normal-weight (18.50-24.99 kg/m(2)), overweight (25-29.99 kg/m(2)), and obese (>30 kg/m(2)). Leipzig, Germany from 2007 to2011. Ninety-six male volunteers without spermatogenesis-associated diseases. None. Semen parameters, reproductive hormones in serum, and leptin, adiponectin, resistin, chemerin, progranulin, vaspin, and visfatin concentrations in serum and seminal plasma. All measured adipokines were detectable in human seminal plasma. The levels of progranulin, visfatin, and vaspin were statistically significantly higher in seminal plasma than in serum. An increase in body weight was associated with decreased levels of seminal plasma progranulin. Additionally, overweight/obese men had statistically significantly lower progranulin levels in seminal plasma than normal weight men. Adiponectin and progranulin concentrations in seminal plasma statistically significantly positively correlated with sperm concentration, sperm count, and total normomorphic spermatozoa. Adipokines are differently regulated in human male reproductive tract compared with the peripheral blood, and they could influence sperm functionality.

Higher clusterin immunolabeling and sperm DNA damage levels in hypertensive men compared with controls

Clusterin, a heterodimeric glycoprotein found at several sites in the human male reproductive tract, could be a marker of morphologically abnormal spermatozoa, while TUNEL positivity indicates DNA fragmentation. Metabolic disorders such as diabetes mellitus and obesity may compromise sperm quality and fertility of men; however, little evidence specifically links hypertension with the impairment of male reproductive function. By flow cytometric, immunofluorescence (TUNEL assay and clusterin immunolabeling) and immunohistochemical (peroxidase-streptavidin method) analyses, we have compared both clusterin- and TUNEL labeling in ejaculated spermatozoa from healthy normotensive donors and hypertensive subjects with the purpose to reveal possible differences between the two conditions. Data analysis from the normotensive (n=25) and hypertensive subjects (n=25) demonstrate a significant correlation between high levels of clusterin immunolabeling and the presence of sperm DNA damage, which is often associated with abnormal morphology. In the normotensive subjects, a low percentage (15.3±4.5) of spermatozoa positive for high levels of clusterin was detected; however, this percentage significantly increased (30.9±13.0) (P<0.01) in hypertensive subjects. Standard semen evaluations does not reveal any significant differences between the two groups of subjects, except for a reduced forward motility and lower sperm vitality in the hypertensive subjects. This pilot study strongly suggests a relationship between hypertension and markers indicative of poor sperm quality. In hypertensive subjects, high levels of clusterin immunolabeling identified a consistent fraction of ejaculated spermatozoa carrying both DNA fragmentation and strong morphological alterations, which was not correlated with age or with sperm cell mortality. The alternative possibility that sperm damage observed is due to adverse effects of anti-hypertensive drugs does not find support in the literature nor in the drug data sheets. The relationship observed between hypertension and human semen represents a novel and possibly relevant information to be considered in the study of male fertility.

Expression of dysadherin in the human male reproductive tract and in spermatozoa

To study expression of dysadherin in human testis, epididymis, and spermatozoa. Prospective study. Basic research laboratory. Testis, epididymis, and testicular spermatozoa from patients under treatment and semen from volunteer donors. Reverse transcription-polymerase chain reaction, immunohistochemistry, immunocytochemistry, and Western immunoblotting. Dysadherin messenger RNA (mRNA) analysis in testis, epididymis, and ejaculated spermatozoa, immunohistochemistry of both tissues, Western immunoblotting of tissue/cell extracts, and immunocytochemistry of spermatozoa. Dysadherin mRNA was found in testis, epididymis, and ejaculated spermatozoa. Whereas testis and spermatozoa exhibited a distinctive 91-kDa protein form, the epididymis showed a 50-kDa moiety, also found in MDA-MB-231 breast cancer cells. Nucleotide sequence analysis revealed >99% homology between testicular and somatic cell mRNA, suggesting differential protein glycosylation. Dysadherin was immunodetected in round spermatids and testicular/ejaculated spermatozoa. It localizes to the acrosomal region and flagellum and colocalized with E-cadherin in the head and with the Na(+),K(+)-ATPase α4 subunit in the flagellum. This is the first report on expression of dysadherin in the male gonad and in spermatozoa. Its colocalization with E-cadherin and Na(+),K(+)-ATPase leads us to postulate a role for dysadherin as a modulator of sperm function.

The human male reproductive tract antimicrobial peptides of the HE2 family exhibit potent synergy with standard antibiotics

Reproductive tract infections pose a serious threat to health and fertility. Due to the emergence of antibiotic resistant pathogens, antimicrobial proteins and peptides of the reproductive tract are extensively characterized in recent years toward developing newer strategies to treat genital tract infections. Pathogen growth inhibition using a combination of naturally occurring male reproductive tract antimicrobial peptides and commonly used antibiotics has not been reported. Checker board analyses were carried out to determine the nature of interaction (synergistic, additive and antagonistic) between HE2alpha and HE2beta2 peptides and the commonly used antibiotics. Using Escherichia coli as the target organism, the minimal inhibitory concentration and fractional inhibitory concentration indices were determined. We demonstrate for the first time that the human male reproductive tract antimicrobial peptides HE2alpha and HE2beta2 act synergistically with the commonly used antibiotics to inhibit E. coli growth. A combination of HE2alpha and HE2beta2 peptides resulted in an additive effect. Interestingly, the synergistic effects of HE2 peptides were highest with doxycycline and ciprofloxacin, antibiotics generally used to treat epididymitis. Results of this study demonstrate the potential of endogenous HE2 peptides to be pharmacologically important in designing novel strategies to treat reproductive tract infections.

Vitamin D receptor and vitamin D metabolizing enzymes are expressed in the human male reproductive tract

The vitamin D receptor (VDR) is expressed in human testis, and vitamin D (VD) has been suggested to affect survival and function of mature spermatozoa. Indeed, VDR knockout mice and VD deficient rats show decreased sperm counts and low fertility. However, the cellular response to VD is complex, since it is not solely dependent on VDR expression, but also on cellular uptake of circulating VD and presence and activity of VD metabolizing enzymes. Expression of VD metabolizing enzymes has not previously been investigated in human testis and male reproductive tract. Therefore, we performed a comprehensive analysis of the expression of VDR, VD activating (CYP2R1, CYP27A1, CYP27B1) and inactivating (CYP24A1) enzymes in the testis, epididymis, seminal vesicle (SV), prostate and spermatozoa. Tissue samples were obtained after orchiectomy (testis n = 13; epididymis n = 7), prostatectomy (prostate n = 5 and SVs n = 3) and semen samples obtained after ejaculation (n = 13). mRNA was detected with RT-PCR and expression of proteins was determined by immunohistochemistry. VDR and VD metabolizing enzymes were concomitantly expressed in round and elongated spermatids, vesicles within the caput epididymis, and glandular epithelium of cauda epididymis, SV and prostate. The expression pattern in ejaculated spermatozoa varied, although, concomitant expression of VDR, CYP2R1, CYP27B1 and CYP24A1 was observed in neck and midpiece in a subpopulation of mature spermatozoa. On the basis of the marked expression of VDR and the VD metabolizing enzymes in human testis, ejaculatory tract and mature spermatozoa, we suggest that VD is important for spermatogenesis and maturation of human spermatozoa.

The influence of type 1 diabetes mellitus on spermatogenic gene expression

Routine semen analysis found no differences in diabetic men; however, mRNA profiles showed changes in the expression of genes involved in oxidative stress.

X-Ray Diffraction Study on Human Male Reproductive Tract and Semen

In the present study authors had separated testis, epididymis-caput, corpus, cauda, vas deferens, seminal vesicle, prostate gland and bulbourethral gland from human male reproductive tract, made it to ash form. Semen also underwent same procedure. All samples had undergone X-ray diffraction analysis. Results Results showed there where two distinct rings for each sample. We named it is “A” &amp;” B”. Under “A” Barium silicate, Barium silicate hydrate and three metal complexes of copper, gold and zinc were seen. Under “B” Calcium silicate and calcium silicate hydrate were observed. Both “A” and “B” were seen throughout the length (expect for “A” is seminal vesicle) and in semen. Conclusions A tri metal complex of copper, gold and zinc is reported in this study, is first of its kind in Biology.