Effect of cytokines on sperm motility and ionophore-stimulated acrosome reaction

An Alternative Application of Magnetic-Activated Cell Sorting: CD45 and CD235a Based Purification of Semen and Testicular Tissue Samples

Magnetic activated cell sorting (MACS) is a well-known sperm selection technique, which is able to remove apoptotic spermatozoa from semen samples using the classic annexinV based method. Leukocytes and erythrocytes in semen samples or in testicular tissue processed for in vitro fertilization (IVF) could exert detrimental effects on sperm. In the current study, we rethought the aforementioned technique and used magnetic microbeads conjugated with anti-CD45/CD235a antibodies to eliminate contaminating leukocytes and erythrocytes from leukocytospermic semen samples and testicular tissue samples gained via testicular sperm extraction (TESE). With this technique, a 15.7- and a 30.8-fold reduction could be achieved in the ratio of leukocytes in semen and in the number of erythrocytes in TESE samples, respectively. Our results show that MACS is a method worth to reconsider, with more potential alternative applications. Investigations to find molecules labeling high-quality sperm population and the development of positive selection procedures based on these might be a direction of future research.

The role of infections and leukocytes in male infertility

Declining birth rates are one of the problems facing society today. Male counterparts are responsible for about half of the infertility cases, and genitourinary tract infections may play a contributing role in approximately 15% of male infertility cases. Leukocytospermia is an established indicator of infection in the male urogenital tract, although other microorganisms such as bacteria and virus may also be contributors to the etiology of male infertility. The pathophysiology of these infectious agents may be initiated by a local inflammatory reaction resulting in an increase in reactive oxygen species (ROS). This results in testicular injury, thereby affecting sperm morphology, sperm motility, sperm viability and elevation of the seminal leukocyte as a result of the genital tract infection. The infectious and inflammatory changes can result in male infertility. It is proposed that high concentrations of seminal leukocyte and infectious agents may affect sperm function resulting in clumping of motile spermatozoa, decreasing acrosomal functionality and also causing alterations in sperm morphology. However, the literature has poorly clarified the role of infection in male infertility, provoking further debate and research on this topic.

Microbiological investigation in male infertility: a practical overview

The roles of inflammation and/or infection of the male accessory sex glands are very important for the potential effects that these conditions may have on male fertility. The clinical andrologist should be aware of the pathophysiological role of the main determinants of sperm damage when these conditions occur, in particular, seminal leukocytes, oxidative stress and cytokines. In addition, it is important to have a good knowledge of the methodologies to be used in clinical practice. This article summarizes the methods used to look for and to identify the micro-organisms responsible for male urogenital tract infections. These include sperm culture, urine culture, urethral swabbing, the Meares–Stamey test and balanopreputial swabbing. Finally, we discuss the role of human papilloma virus infection in male infertility.

Calcium antagonists modulate oxidative stress and acrosomal reaction in rat spermatozoa

INTRODUCTION

Calcium ions are vital in many biological processes and qualify as an almost ubiquitous intracellular second messenger. This indicates the multiplicity of the effects associated with drug actions aimed at interfering with calcium ions. To examine the cellular process involved in the induction of infertility in males by calcium antagonist (CA) even in the presence of normal semen parameters, we studied the effects of different CA namely; nifedipine, verapamil and diltiazem on oxidative balance and acrosome reaction in the sperm.

MATERIAL AND METHODS

For this purpose, lipid peroxidation, antioxidants such as superoxide dismutase, catalase and reduced glutathione, and acrosomal reaction were determined in sperm samples of rats.

RESULTS

Calcium antagonist causes significant oxidative stress in the epididymal sperm with increased malondialdehyde level and a concomitant decrease in antioxidant activities of catalase and superoxide dismutase. The percentage value of acrosomal-reacted sperm in the nifedipine, verapamil and diltiazem-treated rats were 41 ±2.45, 39 ±2.92 and 42 ±1.22 respectively, compared with the control group value of 86 ±2.92.

CONCLUSIONS

It appears CA oxidatively modify the sperm resulting in functional inhibition of acrosomal reaction. Suppression of the sperm acrosomal reaction is known to have serious adverse implications for fertilization.

Male accessory gland infection and sperm parameters (review)

Male accessory gland infection (MAGI) has been identified among those diagnostic categories which have a negative impact on the reproductive function and fertility in males (Rowe et al., World Health Organization Manual for the Standardised Investigation and Diagnosis of the Infertile Couple, Cambridge University Press, Cambridge, 1993). MAGI is a hypernym which groups the following different clinical categories: prostatitis, prostate-vesiculitis and prostate-vesiculo-epididymitis. Some of the characteristics they share are: common diseases, mainly have a chronic course, rarely cause obstruction of the seminal pathways, can have an unpredictable intracanicular spread to one or more sexual accessory glands of the reproductive tract, as well as to one or both sides. In this review, we show that all components involving the inflammatory response (from the agents which first trigger it to each component of the inflammatory response dynamic) can deteriorate conventional and/or non-conventional sperm parameters arising from one or more of the following mechanisms: altered secretory function of the epididymis, seminal vesicles, and prostate which reduce the antioxidant properties or scavenging role of the seminal plasma; deterioration of spermatogenesis; and (unilateral or bilateral) organic or functional sub-obstruction of the seminal tract.

Effect of interleukin-1 receptor antagonist gene deletion on male mouse fertility

Members of the IL-1 family are pleiotropic cytokines that are involved in inflammation, immunoregulation, and other homeostatic functions in the body. IL-1alpha, IL-1beta, and the IL-1 antagonistic molecule [IL-1 receptor antagonist (IL-1 Ra)] are present in the testis under normal homeostasis, and they further increase upon infection/inflammation. In the present study, we examined the effect of IL-1 Ra gene deletion on male mouse fertility. Male mice [wild type (WT) and IL-1 Ra knockout (KO)] were mated with WT females, and the birth and number of offspring were recorded 21-45 d after mating. Furthermore, the concentration, motility, and morphology of sperm isolated from the cauda of the epididymis were evaluated. The ability of the calcium ionophore (A23187) to induce acrosome reaction (AR) in the sperm of WT and IL-1 Ra KO mice was compared with their ability to fertilize in vitro oocytes from WT females. The direct effect of IL-1alpha and IL-1beta on AR and abnormal morphology in sperm from WT were evaluated. The levels of IL-1alpha and IL-1beta in the testes of WT and IL-1 Ra KO mice were examined by specific ELISA and real-time PCR. Our results show a significant reduction in the capacity of IL-1 Ra KO male mice to fertilize WT females (P < 0.05). Furthermore, the number of offspring in mice fertilized with IL-1 Ra KO male mice was significantly lower than with WT males (P < 0.05). Sperm concentration and the percentage of motile sperm from IL-1 Ra KO and WT were similar; however, the percentage of sperm with abnormal morphology (mainly in the head) and acrosome-reacted sperm cells were significantly higher in the IL-1 Ra KO, compared with that of WT males (P < 0.05). In vitro, the ability of sperm from IL-1 Ra KO male mice to fertilize oocytes from WT females was significantly lower than sperm from WT mice (P < 0.05). In addition, the percentage of reacted sperm from IL-1 Ra KO, spontaneously without ionophore induction, was significantly higher than from WT (P < 0.05). Sperm from WT underwent induction of AR only by ionophore; however, sperm from IL-1 Ra KO were unable to undergo the AR by ionophore, indicating that they are induced and, thus, are inactive in fertilization. Testicular IL-1alpha and IL-1beta levels were significantly higher in IL-1 Ra KO, compared with WT male mice (P < 0.05). The addition of recombinant IL-1alpha or IL-1beta to sperm from a WT mouse induced their AR, and significantly increased abnormal sperm morphology, as compared with controls (P < 0.05). This effect was neutralized by the addition of IL-1 Ra. Our results indicate the involvement of IL-1 in sperm physiology, affecting its morphology and fertilization ability. Higher than homeostatic levels of IL-1 in the testis, as observed in IL-1 Ra KO mice, impaired the ability of sperm to fertilize oocytes. Together, these results may explain some of the male infertility cases with an infection/inflammation background and may hint at the ability to use IL-1 Ra in future therapeutic strategies in these cases.

Effects of tumour necrosis factor-alpha on human sperm motility and apoptosis

The aim of this study was to evaluate the effects of tumour necrosis factor-alpha (TNF-alpha) on sperm motility, mitochondrial membrane potential (DeltaPsi), phosphatidylserine (PS) externalization, sperm chromatin packaging quality, and DNA fragmentation. Motile spermatozoa, obtained from 10 normozoospermic men, were incubated with increasing concentrations of TNF-alpha and analyzed 1, 3, 6, and 24 h after incubation by flow cytometry. TNF-alpha decreased total motility 24 h after incubation at 10 ng/mL and progressive motility 3 h after incubation. Accordingly, TNF-alpha reduced sperm DeltaPsi in a concentration- and time-dependent manner. TNF-alpha increased the percentage of spermatozoa with PS externalization from the concentration of 1 ng/mL 1 h after incubation. TNF-alpha produced sperm chromatin and DNA damage in a concentration- and time-dependent manner. In conclusion, these findings may explain the reduction of fertility, secondary to upregulated production of TNF-alpha, in men with urogenital infections.

Infliximab may reverse the toxic effects induced by tumor necrosis factor alpha in human spermatozoa: an in vitro model

OBJECTIVE

To examine the toxic effects of tumor necrosis factor alpha (TNF-alpha) on ejaculated spermatozoa and evaluate the ability of infliximab to reverse these effects.

DESIGN

Prospective controlled study.

SETTING

Cleveland Clinic Foundation, Cleveland, Ohio.

PATIENT(S)

Thirty-one healthy sperm donors.

INTERVENTION(S)

Exposure of human spermatozoa to varying concentrations of TNF-alpha (100, 300, 400, 500 pg/mL, and 2.5 microg/mL) and infliximab (400 microg/mL).

MAIN OUTCOME MEASURE(S)

Sperm motility, functional integrity of plasma membrane, and DNA fragmentation.

RESULT(S)

Spermatozoa quality declined following incubation with TNF-alpha in a dose-dependent and time-dependent manner. Sperm motility and membrane integrity were higher in the samples incubated with TNF-alpha plus infliximab than in the samples treated with TNF-alpha only. These parameters improved significantly and were comparable with both controls and sperm incubated with infliximab alone. Similarly, the percentage of spermatozoa with DNA fragmentation improved significantly following incubation with TNF-alpha plus infliximab and again was comparable with both controls and sperm incubated with infliximab alone.

CONCLUSION(S)

Spermatozoa may be exposed to abnormal levels of TNF-alpha in the male reproductive tract or during their passage into the female reproductive tract (in cases of endometriosis). Exposing spermatozoa to pathological concentrations of TNF-alpha can result in significant loss of their functional and genomic integrity. Infliximab could potentially be used to help treat female infertility caused by endometriosis in those with elevated levels of TNF-alpha in their peritoneal fluid.

Male genital tract inflammation: The role of selected interleukins in regulation of pro-oxidant and antioxidant enzymatic substances in seminal plasma

Human semen contains spermatozoa as well as populations of round nonspermatozoal cells primarily consisting of leukocytes. Activation of white blood cells present in the seminal plasma during genital tract inflammation and cellular reactions against microbial agents may provoke a release of a variety of products such as cytokines and reactive oxygen species. The aim of this study was to evaluate whether a panel of selected cytokines (interleukin [IL]-1 beta, IL-6, IL-8, and tumor necrosis factor-alpha [TNF alpha]) detectable in seminal plasma during male genital tract inflammation could be considered as mediators between altered semen parameters and changed levels of pro-oxidant and antioxidant substances. Studies using chemiluminometric, spectrophotometric, and enzyme-linked immunosorbent assay methods indicate that proinflammatory cytokines such as IL-1 beta, IL-6, IL-8, and TNF alpha may modulate pro-oxidant and antioxidant activities in the male genital tract. The data also suggest that the function of pro-oxidant and antioxidant systems in semen may directly influence basic semen parameters. The elevated numbers of leukocytes present in semen during male genital tract inflammation without an associated contribution of cytokines and semen antioxidant capacity appear to be of little prognostic value in evaluating male fertilization potential.

Plasma membrane and acrosomal integrity in bovine spermatozoa with the knobbed acrosome defect

Previous studies have shown that bovine spermatozoa with the knobbed acrosome defect have a reduced ability to bind to and penetrate the bovine zona pellucida. Cryopreserved spermatozoa from a normal control bull (N) and two bulls with the knobbed acrosome defect (K1 and K2) were subjected to a hypoosmotic swelling test (HOST) to evaluate the functional integrity of the plasma membrane. A capacitation assay and a calcium ionophore challenge test was used to determine the ability of spermatozoa to undergo capacitation and acrosome reaction (AR), respectively. The mean percentage of spermatozoa responding to the HOST was significantly higher for Bull N (68.8 +/- 2.4) than for Bulls K1 (36.1 +/- 4.6) and K2 (40.2 +/- 4.7). The mean percentage of capacitated spermatozoa (54.0 +/- 1.8) was significantly higher for the treatment group (incubation in capacitating medium) for Bull N than that of the negative control group (29.5 +/- 1.8). However, there was no difference between the treatment and the negative control groups of the bulls with the knobbed spermatozoa (36.5 +/- 1.4 and 27.1 +/- 3.0 for Bull K1 and 47.5 +/- 3.8 and 35.2 +/- 6.6 for Bull K2, respectively). Although the mean percentage of acrosome-reacted spermatozoa (60.7 +/- 1.3) was higher for the treatment group (receiving calcium ionophore) for Bull N than that of the negative control (29.5 +/- 1.3), there was no difference between the treatment and the negative control groups for the bulls with the knobbed spermatozoa (47.8 +/- 3.3 and 49.3 +/- 5.0 for Bull K1 and 58.8 +/- 10 and 59.5 +/- 9.7 for Bull K2, respectively). A positive correlation existed between the proportion of spermatozoa that did not respond to the HOST and that undergoing a spontaneous AR. Results suggest that spermatozoa with the knobbed acrosome defect have impaired plasma membrane function which predisposes them to premature capacitation and spontaneous AR on incubation after thawing.

Regional heterogeneity in intracellular distribution of superoxide and hydrogen peroxide within the sperm and its relation to sperm development

This study was performed to understand the regional distribution of superoxide anion radicals and hydrogen peroxide within the spermatozoa of mice during both normal and altered situations of epididymal maturation. The intracellular O2*- levels were probed employing dichlorodihydrofluorescein diacetate (DDF) as a reporter. The testicular spermatozoa from normal animals showed strong regional heterogeneity in the DDF fluorescence patterns over the various domains. Vasectomy resulted in strong inhibition in the O2* levels of spermatozoa at all stages of maturation. Interestingly, the fluorescein diacetate staining pattern was strong in the head of spermatozoa from the testis, caput, corpus, and cauda region. Further. there was a progressive reduction in the fluorescence in the head region in the spermatozoa toward the cauda region. The midpiece and tail showed moderate fluorescence, which also diminished as the spermatozoa matured. The spermatozoa from the vas deferens exhibited a weak fluorescence over the head domain, with the other domain staining extremely weak. Here again, vasectomy introduced considerable loss in the fluorescence intensity. The implications of programmed production of reactive oxygen species in specific domains of the spermatozoa during various stages of development are discussed.

Nonsperm cells in human semen: with special reference to seminal leukocytes and their possible influence on fertility

Nonspermatozoal cells (NSC) in semen, including immature germ cells, leukocytes (WBC) and epithelial cells, are normally found in a concentration less than 15% of the sperm concentration. Cytological staining methods and immunoenzymatic assays for characterization of seminal WBC and methods for detection of various enzymes from WBC are evaluated. Criteria for abnormally high levels of WBC in semen, caused by exogenic factors (e.g., infection) and possibly by endogenic factors (e.g., abnormal sperm), are discussed. Leukocytospermia is associated with reduced in vitro fertilization rate, and experimentally-measured sperm functions (e.g., motility) are inhibited by high concentrations of certain WBC products (e.g., reactive oxygen species and interferon-gamma). At the present stage, the following procedures could be used to evaluate WBC in ejaculates from infertile patients: (1) count the number of NSC using a hemocytometer. (2) Determine the number of WBC in percentage of NSC in smears using the Papanicolaou staining technique, or an immuno-enzymatic assay using monoclonal antibodies to the different kinds of WBC. (3) If, abnormally high levels of WBC (according to the WHO criteria or based on a percentile determined from examination of normal, fertile men) is detected, a second ejaculate should be examined 3 months later. (4) Persistent leukocytospermia should indicate physical and microbiological examinations, after which antibiotic treatment may be indicated.