Hum. Reprod. Advance Access originally published online on August 9, 2008
Human Reproduction 2008 23(12):2858-2866; doi:10.1093/humrep/den277
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Tumor necrosis factor-alpha –308 polymorphism in infertile men with altered sperm production or motility
1 INSERM, U407, Oullins, F-69921 France; Université Lyon I, Lyon, F-69921 France 2 Service d'Histologie Embryologie Cytogénétique & Biologie de la Reproduction, Centre Hospitalier Poissy–St Germain en Laye, and UFR Paris, Ile de France Ouest, 78303 Poissy, France 3 Service de Radioanalyses, Hôpital Neuro-Cardiologique, 69677 Bron, France 4 Institut Rhonalpin, Clinique Sainte-Thérèse, 69500 Bron, France 5 Pôle RhôneAlpin de BioInformatique (PRABI), Centre Hospitalier Lyon-Sud, Pierre-Bénite, F-69495 France 6 Pole Gynécologie Obstétrique Reproduction Endocrinologie (GORE), Hôpital de l'Archet 2, Nice, F-06200 France
7 Correspondence address. Bâtiment Universitaire Archimed, Inserm U895, équipe 5, C3M, 151 Route St Antoine Ginestière, BP2 3094, 06204 Nice, cedex 3; Tel: +33 4 92 03 64 56; Fax: +33 4 92 03 64 40; E-mail: benahmed.m{at}chu-nice.fr
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Abstract |
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BACKGROUND: One of the most well-documented cytokines suspected as a hazard to male fertility is tumor necrosis factor-
(TNF). Genetic factors such as single-nucleotide polymorphisms (SNPs) in the TNF gene cluster impact TNF levels. Our objective was to establish the potential involvement of –308 TNF SNP in male infertility risk.
METHODS: In 684 infertile male patients undergoing an intracytoplasmic sperm injection procedure, we used allele-specific polymerase chain reaction (PCR) and PCR-RFLP to investigate the distribution of the guanine (G)-to-adenosine (A) substitution at position –308 in the promoter region of the TNF gene.
RESULTS: An increased frequency of the –308 TNF A allele was found in patients with low sperm count of testicular origin [P = 0.002; odds ratio (OR) = 2.93] or with normal production count but altered sperm motility (P = 0.003; OR = 2.32), compared with a patient group with normal sperm count and quality (morphology and motility). In patients with low sperm count exhibiting TNF A allele, compared with those with G allele, an alteration in hormonal balance was observed with increased inhibin B levels and subsequent reduced FSH plasma levels, leading to an FSH/inhibin B ratio roughly half as high (from 0.07 ± 0.01 in TNFA versus 0.13 ± 0.02 in TNFG allele groups, P < 0.0001).
CONCLUSION: As the –308 TNF A allele has been associated with an increased expression/production of TNF, the potential use of therapies based on inhibition of TNF activities could represent possible therapeutic opportunities for patients with low sperm count (i.e. primary testicular dysfunction) or with altered sperm motility.
Key words:
tumor necrosis factor-/infertility/polymorphism
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Introduction |
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Approximately 15% of couples attempting their first pregnancy meet with failure. A male impairment is present in
50% of infertile couples, suggesting that male infertility affects 7% of couples around the world (Thonneau et al., 1991
). Although several causes have been identified for impaired male fertility (endocrine dysfunction, post-testicular obstruction, vascular abnormalities, genetic or congenital factors, antispermatogenic agents), little progress has been made in the development of treatment modalities for male infertility (Liu and Handelsman, 2003). Paradoxically, despite this lack of treatment modalities, there has been an explosive growth in the use of various medically assisted reproduction techniques (ART) such as intracytoplasmic sperm injection (ICSI) that have allowed sub- or infertile men to initiate conception without attempting to improve their fertility status with therapies related to the cause(s) of their infertility. In addition, the use of ART is associated with potential genetic risks. Indeed, when treating infertile couples, the ART methods, in particular the ICSI method, potentially enable the hereditary transmission of infertility and other impaired genetic conditions to offspring (Devroey and Van Steirteghem, 2004; Woldringh et al., 2005). Among the therapeutic approaches used to bypass or complete the use of ART is hormonal therapy for infertile patients. However, endocrine therapies are very often insufficient to significantly improve the fertility status of infertile men. This is probably due to the fact that we are still unable to identify the subsets of infertile men who might benefit from these therapies. In this context, our present study aims at identifying subsets of infertile patients according to their specific genetic polymorphisms and particularly cytokine polymorphisms; these patients may therefore potentially benefit from new and/or more appropriate therapeutic opportunities.
Spermatogenesis depends upon numerous local signaling molecules, which provide integration and communication among the different cell types in the testis during hormonal regulation of germ cell maturation. This local regulatory control is supported by a large number of cytokines (Benahmed, 1996; Petersen et al., 2004), among which is the tumor necrosis factor- (TNF). In the testes, TNF receptors (p55) are present in Sertoli and Leydig cells (Mauduit et al., 1996), allowing TNF to modulate their functions. In experimental models, TNF affects both gonadotrophin production and action in the male reproductive function and reduces male fertility (Mauduit et al., 1993, 1998; Benahmed, 1996; Kalra et al., 1998; Huleihel and Lunenfeld, 2004). Some studies have shown TNF levels to be negatively correlated with sperm motility and morphology (Eisermann et al., 1989; Kocak et al., 2002). Genetic factors may impact TNF levels, and several polymorphisms in the TNF gene cluster have been associated with modified TNF production (Hajeer and Hutchinson, 2001). The TNF gene cluster is located within the class III region of the highly polymorphic major histocompatibility complex on chromosome 6p21. The TNF gene lies between the lymphotoxin (TNFβ) and LTB genes (Nedwin et al., 1985). There are many polymorphisms within the TNF gene cluster. So far, six single-nucleotide polymorphisms (SNPs) have been described in the 5' region of the TNF gene, including –238 and –308 G/A SNPs. The –308 G/A SNP is the most commonly studied polymorphism. This SNP, located at nucleotide –308 with respect to the TNF transcriptional start site, substitutes guanine for adenine, and allelic types are referred to as –308G/–308A (Wilson et al., 1992). In the literature, frequency of the A allelic type varies greatly in different populations, e.g. from 0 (Hohjoh et al., 1999) to 51.3% (Yucesoy et al., 2002). Although in French studies the frequency of the SNP appears to be 25%, these studies relate to specific pathologies including non-Hodgkin’s lymphoma (Warzocha et al., 1998), coronary heart disease (Herrmann et al., 1998), pneumoconiosis (Nadif et al., 2003) and metabolic syndrome (Meirhaeghe et al., 2005). However, it should be noted that in all these patient groups, the fertility and endocrine status of the patients are not known. For these reasons, in order to identify a possible association between the presence of the –308 A TNF allelic type and male infertility, specifically with impaired spermatogenesis, it was more appropriate to determine the distribution of the TNF polymorphism among the different subsets of patients exhibiting various infertility etiologies. Specifically, we have evaluated the TNF polymorphism frequency in patients with low sperm count, with or without an obstructive origin, and normal sperm count, with or without morphological or functional alterations.
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Experimental subjects
Men with primary infertility for at least 1 year (684 patients: 257 from Lyon and 427 from Poissy, with an average age of 36.1 ± 0.2 years) who required ICSI procedures were eligible for the present study. Infertile patients had undergone extensive evaluation, including family and personal history, physical and/or ultrasonographic examination, biochemical seminal parameters (carnitine, fructose and citric acid), karyotype, Y deletion and histological testicular analysis for azoospermic patients. Sperm parameters were evaluated according to standard criteria (WHO, 1999
). Hormonal profile [FSH, LH, inhibin B, free or total testosterone, sex hormone-binding globulin (SHBG)] was determined for the different groups. For each patient, a blood sample was collected for DNA analysis. The study was performed under the Declaration of Helsinki rules, and the Ethics Committees and Medical Review Boards of the participating Centers approved the protocol. Informed consent was obtained from all patients.
Infertile patients were classified into four groups before –238 and –308 TNF polymorphism genotyping (Table I). Ethnicity of the patients (mainly from the Caucasian and North African origin) was similar for all four study groups. Major exclusion criteria were age (>50 years), vasectomy, endocrine pathology (hypogonadotropic hypogonadism), hormonotherapy, toxic habits (tobacco, more than 40 cigarettes per day; alcohol and/or drug abuse), immunosuppressive or chronic chemotherapy treatments, unilateral orchidectomy, abnormal karyotype, Y chromosome deletions and chronic genital infections.
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ASPCR and PCR-RFLP analyses
Genomic DNA was extracted from subjects’ blood samples using the Wizard® Genomic DNA Purification Kit (Promega, Southampton, UK). A TNF-R primer (5'-TCTCGGTTTCTTCTCCATCG) was used with either 308-G (5'-ATAGGTTTTGAG GGGCATGG) or 308-A (5'-ATAGGTTTTGAGGGGCATGA) to amplify a 184 bp fragment of the TNF
gene, which includes the polymorphic site at the nucleotide position –308. The primer pair TNF-F (5'-GAGTCTCCGGGTCAGAATGA)/TNF-R was used to amplify a 531 bp TNF gene fragment that was used as an internal control in the allele-specific polymerase chain reaction (ASPCR). Primer TNF-F was also used as a competitor for the TNF-R/A and TNF-R/G primer pairs to improve the specificity of the ASPCR assay (Zhu and Clark, 1996). After initial heating at 95°C for 10 min, 30 PCR cycles were performed and consisted of heat denaturation (95°C for 45 s), annealing (for 150 s at 60°C for the TNF primer pair) and extension (72°C for 45 s). A final extension (72°C for 9 min) was performed. PCR products for –308 A/A, G/G or G/A patients were checked by direct sequencing on an automated ABI Prism 377 DNA Sequencer (Applied Biosystems, Perkin Elmer; Foster City, CA, USA). Similarly, a TNF-R primer (5'-TCTCGGTTTCTTCTCCATGG) was used with either 238-G (5'-GAAGACCCCCCTCGGAACCG) or 238-A (5'-GAAGACCCCCCTCGGAATCA) to amplify a 115 bp fragment of the TNF gene, which includes the polymorphic site at nucleotide position -238. The TNF-F (5'-GAGTCTCCGGGTCAGAATGA)/TNF-R primer pair was used to amplify a 533 bp TNF gene fragment that was used as an internal control in the ASPCR. Accession numbers were rs1800629 and rs361525 for the –308 and –238 TNF SNPs, respectively. A PCR-RFLP approach was also performed for all the patients to evaluate –308TNF polymorphism. The 5' region of TNF gene (–331 to +14) was amplified according to Huang’s report (Huang et al., 1997). The PCR products were digested with NcoI and analyzed on a 2% MetaPhor agarose gel. DNA products were visualized by ethidium bromide staining. The TNF –308G allele would be digested into two fragments (325 and 20 bp), whereas TNF –308A allele would not be digested (345 bp).
Endocrine analyses
LH and FSH plasma levels were measured using Elecsys-LH and Elecsys-FSH kits (Roche, Germany), respectively. Serum inhibin B was measured using an Inhibin B Dimer Assay Kit (Argene Biosoft, France). The detection limit was 18 pg/ml, and the intra- and interassay coefficients of variation were 15 and 18%, respectively. Total plasma testosterone (Tt) was measured by radioimmunoassay after organic extraction and chromatographic pre-purification on Celite columns (Rinaldi et al., 2001). The intra- and interassay coefficients of variation were both <8%. The concentration of T (TnL) that was not bound to SHBG in plasma (free T+ albumin-bound T) was quantified by measuring the T in the supernatants of plasma samples after precipitation with 50% saturated ammonium sulfate (Dechaud et al., 1989). The interassay variation coefficients were <12%. SHBG assays were carried out with an SHBG-RIACT kit (CIS Bio International, Gif-sur-Yvette, France).
Statistical analysis
The prevalence of genotypes involving the –308A TNF allelic types was compared between patients who exhibited decreased sperm counts (Groups I, II and III) and those with normal sperm counts (different four subgroups) using an unconditional logistic regression model (Breslow and Day, 1980). Nested models were compared using likelihood ratio test. The association between groups and genotypes was analyzed using odds ratio (OR) with 95% confidence intervals (95% CI). Statistical tests (two-tailed) with a P-value <5% were considered as significant. The Mann–Whitney U-test was used to analyze FSH, LH, inhibin B, free and total T and SHBG levels in patients with obstructive and non-obstructive oligo- or azoospermia according to the presence or absence of the –308A TNF allelic types; P-values were corrected using the Bonferroni method.
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Increase in –308A allelic type frequency in infertile patients with decreased spermatozoa production or altered motility
The SNP investigated here by allele-specific PCR is a guanine (G)-to-adenosine (A) substitution at position –308 in the promoter region of TNF
gene. ASPCR data were checked by using direct sequencing and the RFLP-PCR approach; representative results are shown in Fig. 1. No discrepancies were observed in –308 TNF SNP incidence between the ASPCR and the RFLP-PCR approaches. –308A TNF SNP was analyzed both in the entire population (Table II, Fig. 2) and in the population with a Caucasian ethnic origin (Table III, Fig. 3). In Table II and Fig. 2A, the data indicate a higher frequency of –308A TNF SNP in infertile patients with non-obstructive oligo- or azoospermia (Group II) compared with (i) patients with oligo- or azoospermia of obstructive origin (Group I) (30.9 versus 13.2%, OR = 2.93, 95% CI 1.39–6.20) and with (ii) patients with normal sperm parameters (i.e. Group IV A–T–) (30.9 versus 19.4%, OR = 1.86, 95% CI 1.07–3.23, P = 0.024). Similar observations were noted in the Caucasian population, where patients with oligo- or azoospermia of non-obstructive origin exhibit a significantly higher (31.2 versus 17.7%) (II versus IV A–T– Caucasian OR = 2.10, 95% CI 1.16–3.83, P = 0.011) frequency of the –308A allele type (Table III and Fig. 3). On the other hand, compared with the patient group with normal parameters (Group IV A–T–), patients from Group I with altered sperm count owing to obstructive origin exhibited a lower, but not significantly lower (13.2 versus 19.4%, OR = 0.63, 95% CI 0.27–1.49, P = 0.29) –308A allelic type frequency. Similarly, in the Caucasian population, Group I patients exhibited a lower, but not significant lower, (12.9 versus 17.7%) (I versus IV A–T– Caucasian OR = 0.69, 95% CI 0.28–1.79, P = 0.44) frequency of the TNF polymorphism. The frequency of the –308A allele was also higher in infertile patients with altered sperm motility (subgroup IV A+) compared with patients with normal sperm motility (32.9 versus 17.5% OR = 2.32, 95% CI 1.32–4.09). No difference in –308A TNF allelic type frequency was observed in the patients exhibiting abnormal sperm morphology (T+) compared with patients with normal sperm morphology (T–). In Table III and Fig. 3, upon examination of –308A TNF SNP frequency in the infertile patient population according to ethnic origin, a comparable distribution of the cytokine polymorphism was observed in the Caucasian population according to the subset of male infertilities. Once again, a higher frequency of –308A TNF SNP was observed in patients with oligo- or azoospermia with primary testicular failure compared with those with obstructive azoospermia (31.2 versus 12.9%) and with patients with normal sperm parameters (31.2 versus 17.7% Group IV A–T–). A higher frequency of the –308A TNF SNP also occurred with asthenospermia (34.3 versus 16.2%). Owing to the limited number of infertile North African patients, we were not able to perform statistical analyses on this population. Finally, it should be noted that the number of homozygote patients was very small, representing 1.5% of all patients (10/684) and 5.7% of patients exhibiting –308 TNF polymorphism. Because of this, both AA and AG allelic types were analyzed together.
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The analysis of the –238 TNF
polymorphism indicates that 12.5% of the entire population exhibits this SNP and that 16.2, 12.4 and 14.3% of the patients from Groups I, II and III, respectively, exhibit this SNP. There was no statistical difference in the percentage of patients exhibiting the –238 TNF SNP among the three groups with decreased sperm count. Similarly, there was no statistical difference in the percentage of patients with normal sperm counts (in the four subgroups of Group IV, i.e. with normal sperm counts; data not shown).
Hormonal pattern changes in patients with non-obstructive oligo- or azoospermia exhibiting –308A TNF polymorphism
The gonadotrophins (FSH and LH), testosterone (total and free T), SHBG and inhibin B plasma levels were evaluated in the different groups of patients. Among the patient groups with decreased sperm count, Group I, as expected, showed a normal hormonal pattern that is consistent with the absence of alterations in the spermatogenetic process, whatever the genotype (Table IV). In Group II patients, without regard to genotype, the association of a decrease in inhibin B plasma levels and an increase in FSH clearly supports the non-obstructive origin (i.e. primary testicular failure of the spermatogenetic process) of the low sperm count. However, in this group, the hormonal pattern and specifically FSH and inhibin B plasma levels were differently affected depending on the –308A allele. In Group II patients with the –308A allele compared with those with the –308G allele, inhibin B plasma levels were significantly (P = 0.0017) higher (Table IV), leading to FSH plasma levels which were significantly (P = 0.0027) lower compared with patients exhibiting the –308G allele. More specifically, the ratio of FSH to inhibin B dropped from 0.13 ± 0.02 in patients with –308G allele to 0.07 ± 0.01 in the presence of the –308A allele (P < 0.0001). LH, total testosterone and SHBG plasma levels were not affected in Group II patients whatever the genotype, except for a very limited (127 ± 5.5 versus 105 ± 3.5) but significant (P = 0.0005) higher level of free testosterone. This level was observed in Group II patients in the presence of –308A allele. When considering GG, AG and AA patients separately, an allelic rate influence on hormone levels can be noted. For example, for FSH levels, the values were 15.7 ± 0.9, 11.4 ± 0.9, 11.7 ± 1 and 8.5 ± 2.4 in the presence of G/G, A/G+A/A, A/G and A/A alleles, respectively. For inhibin B levels, the increase is also dependent on the A allele rate from 60 ± 4 (G/G), 94.3 ± 8.09 (A/G+A/A), 91.7 ± 8.3 (A/G) to 107.7 ± 38.2 (A/A) (Fig. 4). In terms of statistical data analysis, although there were statistically significant differences between AG and GG genotypes, no statistical difference could be observed between GG and AA genotypes (except for free testosterone), due probably to the small number of AA genotype patients (n = 65).
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Discussion |
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Although TNF
–308 polymorphism is considered a potential risk factor when associated with pathological attacks including arthritic or other inflammatory diseases, infection or autoimmune diseases (Abraham and Kroeger, 1999), there has been no study concerning the potential role of –308A TNF polymorphism in infertility, particularly male infertility. The aim of this study was to examine the genotype distribution of –308 TNF gene polymorphism in 684 male patients suffering from infertility with various etiologies and undergoing ICSI procedures. Published data related to carrier frequency of the –308A allele in the general French population report a frequency ranging from 22 to 28%. The two most recent French studies reported frequencies varying from 22 (Berrahmoune et al., 2007) to 28% (Meirhaeghe et al., 2005), with an average frequency 25%. Since the fertility status of this general French population is not known, we considered patient Group IV (A–T–), which exhibited a normal sperm count with no alteration of sperm motility and morphology, as a control group in our present study. On the basis of these criteria, the results show that the frequency of the –308 allele was significantly higher in infertile patients with testicular failure (30.9%) or with altered sperm motility (33.9%) compared with patients with normal sperm parameters (19.4%). An increased frequency in the patient group with testicular failure was also observed when compared with the patient group with decreased sperm count due to an obstructive origin (Group I). Although Group I exhibited a relatively low TNF polymorphism (13.2%), this is not statistically different from that of the control group (Group IV A–T–, 19.4%) with normal sperm parameters (Table II).
The infertile patients studied here are from two French cities, Paris (62.4% of the population) and Lyon (37.6% of population), with two predominant ethnic origins, Caucasian (84.4%) and North African (14.5%). When TNF polymorphism was analyzed solely in the Caucasian population, the data obtained concerning TNF polymorphism distribution in the different infertility subtypes were quite similar to those obtained in the entire population. Indeed, a higher incidence of TNF polymorphism was observed in patients with testicular failure (31.2%) or with altered sperm motility (35.8%) when compared with patient with normal sperm parameters (17.7%). Owing to the limited number of North African patients, statistical analyses of this population were not meaningful. These observations suggest that the TNF polymorphism distribution reported here in the different subtypes of infertile males is nonetheless meaningful for the Caucasian population. Together, these observations indicate that compared with control group patients with normal sperm parameters, we observed an increased frequency in infertile patients with decreased sperm count (due to testicular failure) or altered motility. Although this cytokine polymorphism appears to decrease in patient groups with altered sperm count due to obstructive origin, its frequency was not different from that of the control group, i.e. patients with normal sperm count and quality.
The present results suggest the existence of a potential link between the –308A allelic type and alterations in both spermatozoa production and sperm motility. Assuming that cytokine expression increases in the presence of the –308A allelic type, our present observations also raise the possibility of a new use of the anti-TNF agents in male infertility, since it is now generally accepted that the –308 TNF polymorphism is associated with increased TNF expression/production. Although in in vitro systems (Wilson et al., 1997; Uglialoro et al., 1998), there is some controversy as to whether the –308 TNF polymorphism induces an increase in TNF production, in vivo studies (Warzocha et al., 1998; Gonzalez et al., 2003; Heesen et al., 2003) have clearly established a positive correlation between the polymorphism and an increase in cytokine levels.
TNF is a pleiotropic cytokine that has been implicated in many cellular system activities (Hehlgans and Pfeffer, 2005). This cytokine provides a rapid host defense against infection, but is fatal in excess. TNF also affects lipid metabolism, coagulation, insulin resistance and endothelial function, as well as the hypothalamo-pituitary axis. Cytokines, and particularly TNF, have been widely reported to interact with the endocrine system in the control of testicular functions, at least in experimental (rat, mouse and porcine) models. Several cytokines have direct effects on testicular functions; a number of these, such as TNF, are produced within the testis even in the absence of inflammation or immune activation events. There is compelling evidence that TNF plays an important regulatory role in the development and normal function of the testis (Mauduit et al., 1993, 1998; Benahmed, 1996; Huleihel and Lunenfeld, 2004). TNF has a direct role in the response to gonadotrophins LH and FSH and in the blood–testis barrier (Hellani et al., 2000; Wong and Cheng, 2005). Consequently, local and systemic up-regulation of cytokine expression may contribute to the disruption of testicular functions and fertility. Therefore, in the present study, the patient’s hormonal status was studied by evaluating plasma levels of FSH, inhibin B, LH, T and SHBG. As expected, the hormonal pattern was affected only in Group II patients displaying non-obstructive oligo- or azoospermia but not in the other groups. Interestingly, with regard to the –308 TNF polymorphism, a higher plasma level of inhibin B and a lower plasma level of FSH were found in Group II patients with the –308A allele compared with patients carrying the –308G allele. Specifically, the ratio of FSH to inhibin B was almost halved in patients with the –308A allelic type. Furthermore, these alterations in FSH, inhibin B and free testosterone plasma levels appeared more pronounced in the patients with A/A compared with A/G genotypes, suggesting a possible allelic rate influence on hormone levels. The mechanisms underlying these changes in the plasma gonadotrophin FSH and inhibin B levels in oligo- or azoospermic patients with the –308A allele remain unclear. However, the possibility exists that in the patients bearing this variant allele, the normal adaptive changes of the endocrine system needed to correct a spermatogenetic process failure might be disrupted, independently of etiology. It is generally assumed that spermatogenetic process failure is associated with a decrease in inhibin B levels, which triggers an increase in FSH levels in order to stimulate the spermatogenic process. In the presence of the –308A allele, the levels of inhibin B remained relatively higher compared with oligo- or azoospermic patients with the –308G allele. Sustained higher levels of inhibin B may limit the (beneficial) rise in FSH levels, which would be insufficient to correct the altered spermatogenetic process. For these reasons, we suggest that the relative alteration of these corrective mechanisms in patients carrying the –308A allele could favor a progressively chronic failure of the spermatogenic process.
In addition, the relative increase in TNF polymorphism frequency in infertile patients was associated with asthenospermia in the absence of genital infection. In this context, it should be noted that TNF has been reported to modify sperm motility. For example, TNF in vitro causes a significant reduction in both progressive and total sperm motility (Eisermann et al., 1989; Estrada et al., 1997). The addition of polyclonal rabbit anti-TNF antibody (Eisermann et al., 1989) or the addition of Inflimab, an anti-TNF drug (Said et al., 2005), reverses this inhibitory effect on sperm motility. A recent study has also shown that sperm motility is enhanced when cytokines are inactivated in seminal plasma (Cohen et al., 2004). Although the mechanisms of action of the cytokine on sperm quality (particularly on motility) remain to be elucidated, cytokines, and particularly TNF, can induce reactive oxygen species formation, which may be a significant cause for sperm quality alteration leading to male infertility (Lemkecher et al., 2005). Although the –308 TNF polymorphism does not affect fertility, the cytokine polymorphism may represent a susceptibility factor, which, with other factors (epigenetic, environmental), could provoke alteration of male fertility.
In addition to the –308 TNF polymorphism, we have also determined the frequency of the –238 TNF polymorphism. In contrast to –308 SNP, no significant association was observed between the frequency of –238 TNF polymorphism and the different types of male infertilities. It is noteworthy that -238 TNF polymorphism was not associated with change in TNF expression or production (Pociot et al., 1995).
Finally, as the –308A allele appears to be associated in vivo with increased TNF expression/production, the potential use of anti-TNF agents for male infertility appears plausible. On the basis of the present findings, these biological response modifiers (which neutralize TNF and/or block its signal transduction downstream) could possibly benefit infertile patients. Specifically, these would be two subsets of infertile men: those with reduced sperm production (i.e. with primary testicular dysfunction) or those with decreased sperm motility. These potential therapies could be used alone or in combination with ART in the two subsets of patients identified here.
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This work was supported by Institut National de la Santé et de la Recherche Médicale; Ministère de l’Enseignement Supérieur et de la Recherche, France and Organon France through a FARO (Fond d’Aide à la Recherche Organon) fellowship (to V.T.).
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The authors would like to thank Christelle Rouillac Le Sciellour for her technical help with the RFLP-PCR.
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These authors contributed equally to this paper. 
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References |
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Abraham LJ, Kroeger KM. Impact of the –308 TNF promoter polymorphism on the transcriptional regulation of the TNF gene: relevance to disease. J Leukoc Biol (1999) 66:562–566.[Abstract]
Benahmed M. Growth factors and cytokines in the testis. In: Growth Factors and Cytokines in the Testis—Comhaire FH, ed. (1996) London: Chapman Hall. 55–96.
Berrahmoune H, Herbeth B, Lamont JV, Fitzgerald PS, Visvikis-Siest S. Association between TNF and IL-1 bloc polymorphisms and plasma MCP-1 concentration. Atherosclerosis (2007) 192:348–353.[Medline]
Breslow NE, Day NE. Statistical methods in cancer research. Volume I—The analysis of case–control studies. IARC Sci Publ (1980) 32:5–338.[Medline]
Cohen DR, Basu S, Randall JM, Aballa TC, Lynne CM, Brackett NL. Sperm motility in men with spinal cord injuries is enhanced by inactivating cytokines in the seminal plasma. J Androl (2004) 25:922–925.
David G, Bisson JP, Czyglik F, Jouannet P, Gernigon C. Anomalies morphologiques du spermatozoïde humain. Propositions pour un système de classification. J Gynec Obstet Biol Reprod (1975) 4:17–36.
Dechaud H, Lejeune H, Garoscio-Cholet M, Mallein R, Pugeat M. Radioimmunoassay of testosterone not bound to sex-steroid-binding protein in plasma. Clin Chem (1989) 35:1609–1614.
Devroey P, Van Steirteghem A. A review of ten years experience of ICSI. Hum Reprod Update (2004) 10:19–28.
Eisermann J, Register KB, Strickler RC, Collins JL. The effect of tumor necrosis factor on human sperm motility in vitro. J Androl (1989) 10:270–274.
Estrada LS, Champion HC, Wang R, Rajasekaran M, Hellstrom WJ, Aggarwal B, Sikka SC. Effect of tumour necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) on human sperm motility, viability and motion parameters. Int J Androl (1997) 20:237–242.[CrossRef][Web of Science][Medline]
Gonzalez S, Rodrigo L, Martinez-Borra J, Lopez-Vazquez A, Fuentes D, Nino P, Cadahia V, Saro C, Dieguez MA, Lopez-Larrea C. TNF-alpha –308A promoter polymorphism is associated with enhanced TNF-alpha production and inflammatory activity in Crohn’s patients with fistulizing disease. Am J Gastroenterol (2003) 98:1101–1106.[Web of Science][Medline]
Hajeer AH, Hutchinson IV. Influence of TNFalpha gene polymorphisms on TNFalpha production and disease. Hum Immunol (2001) 62:1191–1199.[CrossRef][Web of Science][Medline]
Heesen M, Kunz D, Bachmann-Mennenga B, Merk HF, Bloemeke B. Linkage disequilibrium between tumor necrosis factor (TNF)-alpha –308 G/A promoter and TNF-beta NcoI polymorphisms: association with TNF-alpha response of granulocytes to endotoxin stimulation. Crit Care Med (2003) 31:211–214.[CrossRef][Web of Science][Medline]
Hehlgans T, Pfeffer K. The intriguing biology of the tumour necrosis factor/tumour necrosis factor receptor superfamily: players, rules and the games. Immunology (2005) 115:1–20.[CrossRef][Web of Science][Medline]
Hellani A, Ji J, Mauduit C, Deschildre C, Tabone E, Benahmed M. Developmental and hormonal regulation of the expression of oligodendrocyte-specific protein/claudin 11 in mouse testis. Endocrinology (2000) 141:3012–3019.
Herrmann SM, Ricard S, Nicaud V, Mallet C, Arveiler D, Evans A, Ruidavets JB, Luc G, Bara L, Parra HJ, et al. Polymorphisms of the tumour necrosis factor-alpha gene, coronary heart disease and obesity. Eur J Clin Invest (1998) 28:59–66.[CrossRef][Web of Science][Medline]
Hohjoh H, Nakayama T, Ohashi J, Miyagawa T, Tanaka H, Akaza T, Honda Y, Juji T, Tokunaga K. Significant association of a single nucleotide polymorphism in the tumor necrosis factor-alpha (TNF-alpha) gene promoter with human narcolepsy. Tissue Antigens (1999) 54:138–145.[CrossRef][Web of Science][Medline]
Huang SL, Su CH, Chang SC. Tumor necrosis factor-alpha gene polymorphism in chronic bronchitis. Am J Respir Crit Care Med (1997) 156:1436–1439.
Huleihel M, Lunenfeld E. Regulation of spermatogenesis by paracrine/autocrine testicular factors. Asian J Androl (2004) 6:259–268.[Web of Science][Medline]
Kalra PS, Edwards TG, Xu B, Jain M, Kalra SP. The anti-gonadotropic effects of cytokines: the role of neuropeptides. Domest Anim Endocrinol (1998) 15:321–332.[CrossRef][Web of Science][Medline]
Kocak I, Yenisey C, Dundar M, Okyay P, Serter M. Relationship between seminal plasma interleukin-6 and tumor necrosis factor alpha levels with semen parameters in fertile and infertile men. Urol Res (2002) 30:263–267.[CrossRef][Web of Science][Medline]
Lemkecher T, Dartigues S, Vaysse J, Kulski O, Barraud-Lange V, Gattegno L, Wolf JP. Leucocytospermia, oxidative stress and male fertility: facts and hypotheses. Gynecol Obstet Fertil (2005) 33:2–10.[CrossRef][Medline]
Liu PY, Handelsman DJ. The present and future state of hormonal treatment for male infertility. Hum Reprod Update (2003) 9:9–23.
Mauduit C, Jaspar JM, Poncelet E, Charlet C, Revol A, Franchimont P, Benahmed M. Tumor necrosis factor-alpha antagonizes follicle-stimulating hormone action in cultured Sertoli cells. Endocrinology (1993) 133:69–76.
Mauduit C, Besset V, Caussanel V, Benahmed M. Tumor necrosis factor alpha receptor p55 is under hormonal (follicle-stimulating hormone) control in testicular Sertoli cells. Biochem Biophys Res Commun (1996) 224:631–637.[CrossRef][Web of Science][Medline]
Mauduit C, Gasnier F, Rey C, Chauvin MA, Stocco DM, Louisot P, Benahmed M. Tumor necrosis factor-alpha inhibits Leydig cell steroidogenesis through a decrease in steroidogenic acute regulatory protein expression. Endocrinology (1998) 139:2863–2868.
Meirhaeghe A, Cottel D, Amouyel P, Dallongeville J. Lack of association between certain candidate gene polymorphisms and the metabolic syndrome. Mol Genet Metab (2005) 86:293–299.[CrossRef][Web of Science][Medline]
Nadif R, Jedlicka A, Mintz M, Bertrand JP, Kleeberger S, Kauffmann F. Effect of TNF and LTA polymorphisms on biological markers of response to oxidative stimuli in coal miners: a model of gene–environment interaction. Tumour necrosis factor and lymphotoxin alpha. J Med Genet (2003) 40:96–103.
Nedwin GE, Naylor SL, Sakaguchi AY, Smith D, Jarrett-Nedwin J, Pennica D, Goeddel DV, Gray PW. Human lymphotoxin and tumor necrosis factor genes: structure, homology and chromosomal localization. Nucleic Acids Res (1985) 13:6361–6373.
Petersen C, Froysa B, Soder O. Endotoxin and proinflammatory cytokines modulate Sertoli cell proliferation in vitro. J Reprod Immunol (2004) 61:13–30.[CrossRef][Web of Science][Medline]
Pociot F, D’Alfonso S, Compasso S, Scorza R, Richiardi PM. Functional analysis of a new polymorphism in the human TNF alpha gene promoter. Scand J Immunol (1995) 42:501–504.[CrossRef][Web of Science][Medline]
Rinaldi S, Dechaud H, Biessy C, Morin-Raverot V, Toniolo P, Zeleniuch-Jacquotte A, Akhmedkhanov A, Shore RE, Secreto G, Ciampi A, et al. Reliability and validity of commercially available, direct radioimmunoassays for measurement of blood androgens and estrogens in postmenopausal women. Cancer Epidemiol Biomarkers Prev (2001) 10:757–765.
Said TM, Agarwal A, Falcone T, Sharma RK, Bedaiwy MA, Li L. Infliximab may reverse the toxic effects induced by tumor necrosis factor alpha in human spermatozoa: an in vitro model. Fertil Steril (2005) 83:1665–1673.[CrossRef][Web of Science][Medline]
Thonneau P, Marchand S, Tallec A, Ferial ML, Ducot B, Lansac J, Lopes P, Tabaste JM, Spira A. Incidence and main causes of infertility in a resident population (1,850,000) of three French regions (1988–1989). Hum Reprod (1991) 6:811–816.
Uglialoro AM, Turbay D, Pesavento PA, Delgado JC, McKenzie FE, Gribben JG, Hartl D, Yunis EJ, Goldfeld AE. Identification of three new single nucleotide polymorphisms in the human tumor necrosis factor-alpha gene promoter. Tissue Antigens (1998) 52:359–367.[Web of Science][Medline]
Warzocha K, Ribeiro P, Bienvenu J, Roy P, Charlot C, Rigal D, Coiffier B, Salles G. Genetic polymorphisms in the tumor necrosis factor locus influence non-Hodgkin’s lymphoma outcome. Blood (1998) 91:3574–3581.
WHO. World Health Organization Laboratory Manual for the Examination of Human Semen and Sperm–Cervical Mucus Interaction. (1999) Cambridge: Cambridge University Press.
Wilson AG, di Giovine FS, Blakemore AI, Duff GW. Single base polymorphism in the human tumour necrosis factor alpha (TNF alpha) gene detectable by NcoI restriction of PCR product. Hum Mol Genet (1992) 1:353.
Wilson AG, Symons JA, McDowell TL, McDevitt HO, Duff GW. Effects of a polymorphism in the human tumor necrosis factor alpha promoter on transcriptional activation. Proc Natl Acad Sci USA (1997) 94:3195–3199.
Woldringh GH, Kremer JA, Braat DD, Meuleman EJ. Intracytoplasmic sperm injection: a review of risks and complications. BJU Int (2005) 96:749–753.[CrossRef][Web of Science][Medline]
Wong CH, Cheng CY. The blood–testis barrier: its biology, regulation, and physiological role in spermatogenesis. Curr Top Dev Biol (2005) 71:263–296.[CrossRef][Web of Science][Medline]
Yucesoy B, Vallyathan V, Landsittel DP, Simeonova P, Luster MI. Cytokine polymorphisms in silicosis and other pneumoconioses. Mol Cell Biochem (2002) 234–235:219–224.[CrossRef]
Zhu KY, Clark JM. Addition of a competitive primer can dramatically improve the specificity of PCR amplification of specific alleles. Biotechniques (1996) 21:586. 590.[Medline]
Submitted on February 9, 2006; resubmitted on March 28, 2008; accepted on April 24, 2008.
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