Production of interleukin-1-like molecules by human sperm cells

Pro-inflammatory cytokines and microRNAs in male infertility

Background

Male infertility is a problem that affects 10–15% of men of reproductive age. In particular, gametogenesis is a complex process in which inflammation may play a central role through the secretion of cytokines and the expression of microRNAs. We assessed the potential role of proinflammatory cytokines (TNF-α, IL-6 and IL-1α) and microRNAs (miR-146a-5p, miR-34a-5p and miR-23a-3p) in the seminal plasma of infertile men compared to controls, evaluating their correlation with seminal and biochemical parameters.

Methods and results

Expression of cytokines and microRNAs was analyzed by ELISA and q-PCR. Our data shows that IL-1α was significantly increased in the azoospermic group compared to controls, TNF-α mRNA was more expressed in the oligozoospermic group than controls. There were no significant differences in miRNAs expression among the three groups. The correlations between sperm parameters and inflammatory markers were evaluated, however no significance was highlighted.

Conclusions

The determination of each inflammatory marker separately in the seminal plasma of subfertile men, despite some significant differences, does not have a diagnostic value in male infertility even if an assay of selective pro-inflammatory cytokines and microRNAs in the semen may improve the diagnosis of male infertility.

Effect of bariatric surgery on endogenous sex hormones and sex hormone-binding globulin levels: a systematic review and meta-analysis

BACKGROUND

Most studies have shown beneficial effect of bariatric surgery (BS) on serum levels of sex hormones.

OBJECTIVE

A systematic review and meta-analysis was conducted to examine the magnitude of possible changes in levels of sex hormones following BS.

SETTINGS

Electronic databases were searched, including PubMed, Scopus, Web of Science, and Embase, for relevant studies.

METHODS

The heterogeneity of the studies was examined by χ² tests and the degree of heterogeneity was estimated using I² statistic.

RESULTS

The results of pooled analyses revealed that BS caused a significant increase in luteinizing hormone (LH), follicular stimulating hormone (FSH), total testosterone (TT), and sex hormone binding globulin (SHBG) levels and conversely, decreased dehydroepiandrosterone (DHEA) and estradiol (E2) levels in males. For females, BS significantly increased LH, FSH, and SHBG levels and conversely, decreased androstenedione (AE), E2 and TT levels. Additionally, the level of progesterone (P), prolactin (PRL), free testosterone (FT) and dehydroepiandrosterone sulfate (DHEA-S) showed no significant changes in patients who had undergone BS.

CONCLUSION

BS changed most sex hormones levels including LH, FSH, TT, SHBG, AE, DHEA, and E2. It seems that BS is able to exert substantial impacts on sex hormones levels and as well as sexual function, however, larger, and more precise trials are required to specifically focus on these claims.

Profiling signaling proteins in human spermatozoa: biomarker identification for sperm quality evaluation

OBJECTIVE

To determine the correlation between semen basic parameters and the expression and activity of signaling proteins.

DESIGN

In vitro studies with human spermatozoa.

SETTING

Academic research institute.

PATIENT(S)

Thirty-seven men provided semen samples for routine analysis.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Basic semen parameters tracked included sperm DNA fragmentation (SDF), the expression levels of 75 protein kinases, and the phosphorylation/cleavage patterns of 18 signaling proteins in human spermatozoa.

RESULT(S)

The results indicated that the phosphorylated levels of several proteins (Bad, GSK-3β, HSP27, JNK/SAPK, mTOR, p38 MAPK, and p53), as well as cleavage of PARP (at D214) and Caspase-3 (at D175), were significantly correlated with motility parameters. Additionally, the percentage of morphologically normal spermatozoa demonstrated a significant positive correlation with the phosphorylated levels of p70 S6 kinase and, in turn, head defects and the teratozoospermia index (TZI) showed a significant negative correlation with the phosphorylated levels of Stat3. There was a significant positive correlation between SDF and the teratozoospermia index, as well as the presence of head defects. In contrast, SDF negatively correlated with the percentage of morphologically normal spermatozoa and the phosphorylation of Akt and p70 S6 kinase. Subjects with varicocele demonstrated a significant negative correlation between head morphological defects and the phosphorylated levels of Akt, GSK3β, p38 MAPK, and Stat1. Additionally, 34 protein kinases were identified as expressed in their total protein levels in normozoospermic samples.

CONCLUSION(S)

This study contributed toward establishing a biomarker "fingerprint" to assess sperm quality on the basis of molecular parameters.

Interleukin-1β, cyclooxygenase-2, and hypoxia-inducible factor-1α in asthenozoospermia

Impaired male fertility may have a variety of causes, among which asthenozoospermia. In its etiology, several bioactive substances, such as cytokines may be involved. In this context, our aim was to evaluate the expression of interleukin-1β, cyclooxygenase-2, and hypoxia-inducible factor-1α, in spermatozoa isolated from normospermic fertile donors and asthenozoospermic infertile patients. We evaluated twenty-eight infertile patients affected by idiopathic asthenozoospermia and twenty-three normospermic fertile donors, age-matched. Sperm parameters were evaluated; immunohistochemical analysis and enzyme-linked immunosorbent assay were then performed in isolated spermatozoa. Spermatozoa from the asthenozoospermic group presented an increased expression of IL-1β, COX-2, and HIF-1α compared with the normospermic fertile subjects. Our results can lead us to speculate that the increased expression of these substances may influence sperm motility. Nevertheless, further studies are needed in order to assess whether these bioactive mediators have a potential relevance as targets in future therapeutic strategies for the treatment of male infertility.

Unraveling the sperm proteome and post-genomic pathways associated with sperm nuclear DNA fragmentation

PURPOSE

Sperm DNA fragmentation has been suggested as a marker for infertility diagnosis and prognosis. Hence, understanding its impact on male physiology and post-genomic pathways would be clinically important. We performed the proteomics and functional enrichment analyses of viable spermatozoa from ejaculates with low and high sperm DNA fragmentation to identify protein expression and pathways altered in association with sperm DNA fragmentation.

METHODS

Sperm DNA fragmentation using the Comet assay and the Komet 6.0.1 software was assessed in raw samples from 89 subjects from a human reproduction service. The Low and High sperm DNA fragmentation groups were formed according to the Olive Tail Moment variable. Spermatozoa proteins from these groups were pooled and analyzed by a shotgun proteomic approach (2D nanoUPLC-ESI-MS(E)). Differentially expressed proteins were used for a functional enrichment study.

RESULTS

Two hundred and fifty-seven proteins were identified or quantified in sperm from the Low and High sperm DNA fragmentation groups. Of these, seventy-one proteins were exclusively or overexpressed in the Low group, whereas twenty-three proteins were exclusively or overexpressed in the High group. One hundred and sixty-three proteins were conserved between these groups. We also functionally related the differentially expressed proteins in viable spermatozoa from the groups. Processes such as triacylglycerol metabolism, energy production, protein folding, response to unfolded proteins, and cellular detoxification were found to be altered in these cells.

CONCLUSIONS

Sperm DNA fragmentation is associated with differential protein expression in viable spermatozoa. These proteins may potentially be used as biomarkers for sperm DNA integrity.

Effects of atrazine and chlorpyrifos on the mRNA levels of IL-1 and IFN-γ2b in immune organs of common carp

Atrazine (ATR) and chlorpyrifos (CPF) are widely used in agriculture has resulted in a series of toxicological and environmental problems. The aim of this study was to investigate the effects of ATR, CPF and their mixture on the mRNA levels of interleukin-1β (IL-1β), interleukin receptor I (IL-1RI) and interferon gamma (IFN-γ2b) in both spleen and head kidney of Common carp. In this study, juvenile common carp were exposed to ATR (at concentrations of 4.28, 42.8 and 428 μg/L), CPF (at concentrations of 1.16, 11.6 and 116 μg/L), and their mixture (at concentrations of 1.16, 11.6 and 116 μg/L). The mRNA levels of IL-1β, IL-1R1 and IFN-γ2b in spleen and head kidney were detected by using RT-PCR. Our results indicated that IL-1β, IL-1R1 expression significantly increased after exposure in high concentration ATR, CPF and their mixture, but IFN-γ2b mRNA shown different expression trends. Our results suggested that ATR, CPF and their mixture probably induced damages on spleen and head kidney may be association with increasing IL-1β, IL-1R1 mRNA synthesis. After 20-day recovery test, IL-1β, IL-1R1 and IFN-γ2b mRNA expression remain at high level in majority of the treated groups, we concluded that the restoration of tissue and immune system damage probably needs longer time.

Distinct expression of interleukin-1α, interleukin-1β, and interleukin-1 receptor antagonist in testicular tissues and cells from human biopsies with normal and abnormal histology

Cytokines are paracrine/autocrine growth factors known to affect testicular cell functions. The cellular origin and expression levels of interleukin-1 (IL-1) in human normal and pathological testicular biopsies are not yet clear. In the present study, we have investigated the levels and cellular origin of IL-1 family members [IL-1α, IL-β, and IL-1 receptor antagonist (IL-1ra)] in human testicular normal and abnormal biopsies with incomplete maturation arrest (IMA) or Sertoli only syndrome (SOS), using real-time polymerase chain reaction and immunohistochemical staining analysis. Our results show that the levels of IL-1α were higher in Leydig/interstitial cells of biopsies with IMA and SOS compared with normal. The levels of IL-1α in Sertoli cells of normal biopsies were higher than IMA and SOS. The mRNA levels of IL-1α were similar in all biopsies. IL-1β levels were higher in Leydig/interstitial cells of normal biopsies compared with Sertoli and germ cells. The levels of IL-1β were similar in testicular cells of all biopsies. However, the mRNA levels of IL-1β were significantly lower in SOS and IMA biopsies compared with normal. IL-1ra was expressed only in Leydig/interstitial cells, and their expression in normal biopsies was higher than in biopsies with IMA and SOS. The mRNA levels of IL-1ra were similar in all biopsies. Thus, it is possible to suggest the involvement of IL-1 system in the regulation of spermatogenesis and male infertility.

Antimicrobial responses in the male reproductive tract of lipopolysaccharide challenged rats

PROBLEM

Innate immune machinery including the Toll-like receptors (TLRs) confers the first line of defense mechanisms to counter pathogenic microorganisms that enter the body. The male reproductive tract is vulnerable to infection and the role of TLRs and the antimicrobial responses that operate to counter infections in this organ system are poorly understood.

METHOD OF STUDY

Caput and cauda epididymides, testes and seminal vesicles were collected at 0, 3, 6, 9, 12, 15 and 24 h from rats injected intraperitoneally with a single dose of LPS. Plasma testosterone was measured using ELISA. Expression pattern of defensins and Spag11 isoforms were analysed using RT-PCR. Immunohistochemical analyses was performed to determine SPAG11E protein expression following LPS treatment.

RESULTS

We provide the first line of evidence that the male reproductive tract induces the expression of Sperm Associated Antigen 11 (Spag11) mRNA variants and defensins when challenged with lipopolysaccharide (LPS) with a concomitant increase in protein expression. However, there was an inverse relationship between induction of antimicrobial gene expression and plasma testosterone. An increase in the mRNA levels of proinflammatory cytokines was observed parallel to the induction of Spag11 variants and majority of defensin expression in the male reproductive tract.

CONCLUSION

The increase in Spag11 and defensin mRNA in response to LPS administration demonstrates their importance in protecting the male reproductive tract during infection. Results of this study help to understand male reproductive tract innate immune defense mechanisms and to design novel peptide antibiotics to prevent sexually transmitted diseases.

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.

Interleukin 1 alpha (IL1A) is a novel regulator of the blood-testis barrier in the rat

Throughout spermatogenesis, leptotene spermatocytes must traverse the blood-testis barrier (BTB) at stages VIII-XI to gain entry into the adluminal compartment for continued development. However, the mechanism underlying BTB restructuring remains somewhat elusive. In this study, interleukin 1 alpha (IL1A) was administered intratesticularly to adult rats in order to assess its effects on spermatogenesis. IL1A was shown to perturb Sertoli-germ cell adhesion, resulting in germ cell loss from approximately 50% of seminiferous tubules by 15 days posttreatment. Equally important, the functional integrity of the BTB was compromised when inulin-fluorescein isothiocyanate was detected in the adluminal compartment of the seminiferous epithelium following its administration via the jugular vein. Interestingly, IL1A did not affect the steady-state levels of proteins that confer BTB function, namely OCLN, CLDN1, F11R, TJP1, and CDH2. Instead, the localizations of OCLN, F11R, and TJP1 in the seminiferous epithelium were altered; these proteins appeared to move away from sites of cell-cell contact. Moreover, IL1A was shown to perturb the orderly arrangement of filamentous actin at the BTB and apical ectoplasmic specialization with distinct areas illustrating loss of actin filaments. Taken collectively, these results suggest that IL1A-induced BTB disruption is not mediated via the reduction of target protein levels. Instead, IL1A's primary cellular target appears to be the Sertoli cell actin cytoskeleton. It is possible that localized production of IL1A by Sertoli and/or germ cells in vivo results in BTB restructuring, and this may facilitate the movement of leptotene spermatocytes across the BTB.

Amount of seminal IL-1beta positively correlates to HIV-1 load in the semen of infected patients

BACKGROUND

Cytokines present in the sperm could influence the heterosexual transmission of HIV by modulating viral titers and influencing the early immune response in the vaginal mucosa.

OBJECTIVES

To assess the relation between cytokine concentrations and HIV status in the seminal plasma.

STUDY DESIGN

Twenty-five HIV positive subjects were tested for cytokine content and HIV-1 load in seminal and blood plasma through a cross-sectional study.

RESULTS

HIV positive subjects exhibited a significantly higher amount of seminal IL-1beta as compared to a group of 33 HIV negative controls. In HIV positive subjects, amounts of IL-1beta and HIV-1 RNA in semen were significantly correlated and a trend for correlation was found between seminal IL-1beta and blood HIV-1 RNA. Amount of seminal IL-1beta was significantly lower in patients under HAART, according to the decrease of their viral loads in blood and semen.

CONCLUSIONS

Considering that IL-1beta is known to enhance viral replication and to promote immune response, its dosage in semen could represent an interesting marker for identifying patients at high risk for HIV heterosexual transmission.

Increased expression of interleukin-1α and interleukin-1β is associated with experimental varicocele

OBJECTIVE

To describe the effect of varicocele, in an experimental rat model, on the levels of IL-1alpha and IL-1beta proteins in testis tissue.

DESIGN

Comparative and controlled study.

SETTING

Experimental research.

ANIMAL(S)

Wistar male rats in experimental and control groups.

INTERVENTION(S)

The control group underwent sham operation (n = 6). Experimental groups underwent partial ligation of the renal vein to induce experimental varicocele and were then killed at 9 (n = 6), 11 (n = 6), and 13 (n = 6) weeks after induction of varicocele.

MAIN OUTCOME MEASURE(S)

Histologic evaluation of the varicocele model was determined by periodic acid-Schiff staining of paraffin-embeded testicular tissues. Levels of cytokines were assessed by immunohistochemistry and Western blot analysis.

RESULT(S)

Varicocele caused testicular damage, especially in 11- and 13-week-old varicocele groups. In sham-operated rats, Golgi complexes of round spermatids expressed especially the alpha form of IL-1. By the progression of varicocele, the IL-1alpha expression increased temporally in Sertoli cells, spermatogonia, primary spermatocytes, spermatids, and Leydig cells. The expression of IL-1beta was seen in Leydig cells in sham-operated rats. The IL-1beta expression was also increased upon progression of varicocele in Leydig cells, Sertoli cells, and spermatogonia.

CONCLUSION(S)

We suggest that IL-1alpha and IL-1beta are the regulators of testicular function. Certain pathologic conditions, e.g., varicocele, cause an increase in the expressions of such proinflammatory cytokines. The increased expression of IL-1alpha and IL-1beta in varicocele shifts the balance in favor of inflammatory and immune responses and causes detrimental effects in testis tissue, which may cause male infertility.

Induction of IL-1, in the Testes of Adult Mice, Following Subcutaneous Administration of Turpentine

PROBLEM

Interleukin-1 family is present in the testicular homogenates and its cellular compartments. It has been suggested that IL-1 is involved in physiological and pathological functions of the testicular tissues. In the present study we examined the effect of acute mostly localized inflammation, using turpentine, on the expression levels of testicular IL-1 system.

METHODS OF STUDY

Mice were subcutaneously injected with steam-distilled turpentine or saline (control). Three hours to 10 days following the injection, mice were killed and testis and spleen were homogenized and examined for interleukin (IL)-1alpha, IL-1beta, and IL-1 receptor antagonist (IL-1ra) levels by enzyme-linked immunosorbent assay and polymerase chain reaction.

RESULTS

Subcutaneous injection of turpentine induced mice systemic inflammation, as indicated by significant increase in serum IL-1beta levels, and IL-1alpha, IL-1beta and IL-1ra in spleen homogenates. The levels of IL-1alpha, IL-1beta and IL-1ra were significantly induced in testicular homogenates of adult mice following subcutaneous injection of turpentine. The significant induction of testicular IL-1alpha was detected after 3-24 hr of turpentine injection and decreased later (after 3-10 days) to levels similar to the control. However, significant induction of testicular IL-1beta was detected only after 3-10 days of turpentine injection, and for testicular IL-1ra levels was detected after 3 hr to 6 days of turpentine injection, and after 10 days the levels were similar to the control. These results were also confirmed by mRNA expression of these factors.

CONCLUSION

Our results demonstrate for the first time the distant effect of acute localized inflammation on testicular IL-1 levels. Thus, transient inflammatory response to infectious/inflammatory agents at non-testicular sites that elicit systemic IL-1 response should be considered during clinical treatment as a possible factor of male infertility.

Cloning of the Atlantic salmon (Salmo salar) IL-1 receptor associated protein

In mammals, the pro-inflammatory cytokine interleukin-1 signals through a receptor complex containing a type I interleukin-1 receptor (IL-1RI) and a receptor associated protein (IL-1RAcP). Previously, we have described a cDNA from Atlantic salmon encoding a molecule with homology to the mammalian IL-RI. This molecule was named IL-1 receptor like protein (IL-1RLP) in the absence of functional data to support its proposed role as the salmon IL-1RI. Here, we describe the cloning and characterisation of a cDNA encoding salmon IL-1RAcP. Like other members of the IL-1R family, the salmon IL-1RAcP encodes three extracellular immunoglobulin-like domains and a cytoplasmic Toll/Interleukin-1 receptor (TIR) domain involved in signalling. Specific binding of salmon IL-1RAcP to IL-1RLP was shown by co-immunoprecipitation studies.

Sequencing and expression of the second allele of the interleukin-1beta1 gene in rainbow trout (Oncorhynchus mykiss): identification of a novel SINE in the third intron

A lambda clone containing a rainbow trout IL-1beta1 gene was isolated by a PCR screening strategy from a genomic library cloned in lambda GEM-11, and an EcoRI fragment from this clone was fully sequenced, and contained 1680 bp 5'-flanking sequence, the whole IL-1beta1 gene open reading frame, and the 3'-flanking region with two potential poly A signals and poly A sites. This clone encoded a protein that shared 99.8% identity to the previously published trout IL-1beta1 cDNA sequence, with only three base substitutions. The main difference was that this clone had an additional complete HpaI SINE insertion in the 3rd intron making intron III 211 bp larger (834 bp via 623 bp). Thus this sequence was designated as allele B (Big intron III) of IL-1beta1 and the previously reported sequence as allele S (Short intron III). Three lines of evidence (allele specific PCR, cloning and sequencing, and direct sequencing of PCR products) revealed that allele B was constitutively expressed and could respond to stimulation with lipopolysaccharide or trout recombinant IL-1beta. Searching of the GenBank database with the HpaI SINE sequence resulted in three additional HpaI loci being identified in rainbow trout. Another SINE retroposition was also identified in the same intron of both alleles of IL-1beta1 by comparison with the trout IL-1beta2 gene. This novel SINE sequence, sharing high homology with the HpaI SINE at the 3'-end region, is present in EST databases of several species including human, mouse and fish. The consensus of this novel SINE shares 57 to 61% identities to tRNA-Leu from different species. Another older retroposition event in the same intron of IL-1beta1 has also been hypothesised, recognised as six adenines, that may function as a RNA polIII terminator. A model for the IL-1beta1 allele formation is proposed. Following the earliest retroposition into one of the two IL-1beta genes that resulted from a genome duplication in salmonids, the proper environment for successive PV SINE retroposition was created. A recent retroposition of the HpaI SINE in IL-1beta1 resulted in the formation of the two alleles of IL-1beta1. Examination of the SINEs insertion and their host gene microenvironments revealed that the SINE retroposition does not appear random, both in the site selection and the direction of insertion. The mechanism governing this outcome is discussed.

Expression of IL-2alpha and IL-2beta receptors on the membrane surface of human sperm

Cytokines are secreted proteins that act as local immunological mediators. Increased seminal cytokine concentrations are associated with fertility problems. The purpose of the present study was to investigate the presence of IL-2alpha, and IL-2beta receptors on fresh and isolated sperm by flow cytometry and transmission electron microscopy. Twenty sperm samples from oligospermic men were incubated with CD25, a mouse monoclonal antibody specific for IL-2alpha-chain receptor, and CD122, a mouse monoclonal antibody specific for IL-2beta-chain receptor. The strong initial fluorescence intensity and, subsequently, a labeling index yielded by CD25 and CD122 decreased in sperm centrifuged on a Percoll gradient (p < .05). The expression of CD25 and CD122 correlated negatively with fresh sperm concentration, but in sperm centrifuged on a Percoll gradient there was no correlation. Labeling with CD25 and CD122 antibody was evident on the head and the middle piece in fresh sperm, while in sperm centrifuged on a Percoll gradient a weak labeling was observed only on the principal piece. The authors have identified and localized cytokine receptors on human sperm for the first time. Cytokine receptors may be involved in the regulation of pathophysiological events in sperm cell functions and male infertility. The exact pathway involved in modulation of these receptors requires further investigation. These results contribute to the understanding of cytokine-sperm relationships.

Cloning and functional characterisation of the interleukin-1 beta 1 promoter of rainbow trout (Oncorhynchus mykiss)

The upstream flanking region of the rainbow trout (Oncorhynchus mykiss) IL-1 beta 1 gene has been cloned and characterised functionally using luciferase-based reporter gene constructs, and the transcription start site (TSS) confirmed by RLM-RACE. A TATA box was present 27 bp upstream of the TSS, with an NF-kB site 19 bp upstream of the TATA box. Within 1217 bp of upstream sequence, 3 sites for NF-kB, 10 sites for NF-IL6, 15 sites for AP1, 6 sites for AP4, 2 sites for CHOP/CEBP alpha and 1 site for SP1 and PU.1 were identified. Seven potential sites for the transcription repressor Gfi-1 were also identified. Analysis of eight IL-1 beta 1s promoter luciferase constructs transfected into a trout fibroblast (RTG-2) cell line known to constitutively express IL-1 beta revealed that in the absence of intron 1, very low luciferase activity was detectable. All of the constructs containing intron 1 gave clear luciferase activity, with the highest luciferase activity detected with construct P2-4 containing 617 bp of upstream sequence. As little as 82 bp of upstream sequence gave relatively strong luciferase activity, a region containing both a PU.1 and NF-kB site. That NF-kB is a transcription factor required for expression of the trout IL-1 beta 1 gene was confirmed using inhibitor studies with lipopolysaccharide (LPS)-stimulated macrophages. Both trout recombinant IL-1 beta and LPS were able to increase luciferase activity in the reporter constructs, especially in those containing the most upstream sequence with the lowest constitutive expression. The possibility that an upstream repressor is functioning to inhibit constitutive expression of IL-1 beta in this species is discussed.

Interleukin-1 beta and tumor necrosis factor-alpha in normal/infertile men

Cytokines play an important role in intercellular communications. Human sperm contains a wide spectrum of cytokines. such as interleukin-1 beta (IL-1beta) and tumor necrosis factor alpha (TNF-alpha). Their effects on semen quality are subject to debate. The aim of this study was to determine concentrations of IL-1beta and TNF-alpha in normal fertile men and in different groups of male infertility in an attempt to clarify the physiology and suggest possible clinical uses. Sixty-six subfertile male patients with varicocele (n = 22). infection of accessory genital glands (n = 14), varicocele plus infection (n = 4), chronic epididymitis (n = 8). post-renal transplantation status (n = 5), idiopathic oligoasthenoteratospermia (n = 9), cryptorchidism (n = 1), and homozygous beta-thalassemia (n = 3) as well as 5 male controls were studied through history, physical examination, spermiograms, plasma basal hormonal levels, and IL-1beta and TNF-alpha levels in seminal fluid. There was no significant statistical difference regarding IL-1beta and TNF-alpha among fertile men and subfertile patients of any cause. 1L-1beta and TNF-alpha were in tight positive correlation (p<.001). Determination of IL-1beta and TNF-alpha does not provide useful information in male routine infertility workup. Nevertheless, a better understanding of these mediators in semen of normal men and infertile patients may contribute to a new approach to the management of male infertility.

Involvement of intratesticular IL-1 system in the regulation of Sertoli cell functions

The Interleukin-1 (IL-1) system has been suggested to be involved in the cell-cell cross talk within the testis. To investigate the testicular autocrine, paracrine and endocrine factors involved in the regulation of Sertoli cell functions, we have examined the capacity of Sertoli cell cultures, from immature mice, to produce IL-1alpha, IL-1beta and IL-1 receptor antagonist (IL-1ra) under in vitro cultures and in the presence of testicular physiological and pathological factors. Our investigation revealed that Sertoli cells produce large amounts of IL-1alpha, IL-1ra but not IL-1beta under basal culture conditions, as examined by ELISA and immunohistochemical staining. Liposaccharides (LPS), as well as IL-1alpha and IL-1beta were found to stimulate IL-1alpha and IL-1ra, but not IL-1beta production, in Sertoli cells from immature mice. Maximum concentration of IL-1alpha and of IL-1ra was observed after 2 and 8 h after the stimulation, respectively. The addition of IL-1ra to Sertoli cells did not alter their capacity to constitutively produce IL-1alpha. However, the stimulatory effects of recombinant IL-1alpha on IL-1alpha production by Sertoli cells were reversed by the concomitant addition of recombinant IL-1ra. FSH is capable to induce IL-1ra production in Sertoli cells in a dose-dependent manner but not IL-1alpha or IL-1beta. As expected, Sertoli cell cultures were also shown to constitutively secrete transferrin. Stimulation of these cultures with IL-1alpha, IL-1beta significantly increased their capacity to secrete transferrin. Addition of IL-1ra to unstimulated Sertoli cell cultures did not affect their capacity to secrete transferrin. Stimulation of Sertoli cell cultures with a combination of both IL-1alpha and FSH or IL-1beta and FSH showed additive effect between IL-1 and FSH in their capacity to induce transferrin secretion by these cells. However, stimulation of Sertoli cells with a combination of both IL-1ra and FSH did not affect their capacity to secrete transferrin as compared with FSH-stimulated cultures. Our results with Sertoli cells, in addition to previous data on Lydig cell and germ cells, may suggest the involvement of the IL-1 system in testicular paracrine/autocrine regulation, which could be involved in the regulation of spermatogenesis and spermiogenesis processes and male fertility.

Induction of transferrin secretion in murine Sertoli cells by FSH and IL-1: the possibility of different mechanism(s) of regulation

In the present study we examined the capacity of interleukin-1 (IL-1) alpha, beta, interleukin-1 receptor antagonist (IL-1ra) and follicle stimulating hormone (FSH) to induce transferrin secretion by Sertoli cells under in vitro conditions. Primary Sertoli cell (SC) cultures from immature mice secreted constitutively transferrin. Stimulation of these cultures with IL-1alpha, IL-1beta significantly increas\d their capacity to secrete transferrin. Addition of IL-1ra to unstimulated SC cultures did not affect their capacity to secrete transferrin. Stimulation of SC cultures with a combination of both IL-1alpha and FSH or IL-1beta and FSH showed additive effect between IL-1 and FSH in their capacity to induce transferrin secretion by these cells. However, stimulation of Sertoli cells with a combination of both IL-1ra and FSH did not affect their capacity to secrete transferrin compared with FSH-stimulated cultures. Our results may suggest the involvement of testicular paracrine/autocrine factors (IL-1) and endocrine (FSH) factors in the regulation of transferrin secretion by SC. This capacity seems to be differently regulated by these factors. Thus, IL-1alpha and beta may directly affect physiological functions of the testis; which may suggest their involvement in the regulation of spermatogenesis and spermiogenesis processes and male fertility.

Members of the Janus kinase/signal transducers and activators of transcription (JAK/STAT) pathway are present and active in human sperm

OBJECTIVE

To investigate whether components of the Janus kinase/signal transducers and activators of transcription (JAK/STAT) pathway are present and active in human sperm.

DESIGN

Comparative study.

SETTING

Reproductive biology department.

PATIENT(S)

Nine sperm donors.

INTERVENTION(S)

Sperm were exposed to interferon-alpha (IFN-alpha), IFN-gamma, interleukin-12 (IL-12), Ca2+ ionophore (A23187), or progesterone under capacitating conditions.

MAIN OUTCOME MEASURE(S)

Cell lysates prepared from sperm and Jurkat T-cell line were resolved by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and the expression of JAKs (1-3 and TYK 2) and STATs (1-6) was examined by Western blot analysis. Effect of IFN-alpha, IFN-gamma, IL-12, A23187, or progesterone on sperm STAT 1 or STAT 4 phosphorylation was determined by phospho-STAT 1 antibody or antiphosphotyrosine (APT) Western blot analysis. Indirect immunofluorescence and confocal laser scanning microscopy was used to confirm the specific staining of anti-TYK 2, anti-STAT 1, and anti-STAT 4 antibodies.

RESULT(S)

By Western blot analysis, only antibodies to TYK 2 of the JAK family, and antibodies to STAT 1 and STAT 4 members of the STAT family specifically recognized protein bands corresponding to TYK 2, STAT 1, and STAT 4 described in other cell types. By confocal microscopy, antibodies to TYK 2 reacted with the sperm tail as well as the apical region of sperm head, whereas antibodies to STAT 1 and STAT 4 reacted with the apical region of the sperm head. Tyrosine phosphorylation of STAT 1 in capacitated sperm was enhanced by IFN-alpha and IFN-gamma, and that of STAT 4 was enhanced by IL-12. Both A23187 and progesterone markedly inhibited tyrosine phosphorylation of sperm STAT 4.

CONCLUSION(S)

Members of the JAK/STAT proteins, TYK 2, STAT 1, and STAT 4 are present and active in human sperm. The localization of STAT 1 and STAT 4 proteins to the apical region of the sperm head and their activation by IFN-alpha, IFN-gamma, or IL-12 implicate a role for sperm STAT proteins in fertilization. We hypothesize that sperm-derived phosphorylated STAT 1 and STAT 4 could contribute to the pool of transcription factors during sperm-oocyte fusion as well as transmit signal to the oocyte nucleus. Therefore, defects in sperm TYK 2 and STAT 1- or STAT 4-mediated signaling pathway may have relevance to male factor infertility.