Male Fertility in Spondyloarthritis: from Clinical Issues to Cytokines Milieu. A Narrative Review

PURPOSEOF REVIEW

Male fertility is an emergent issue that should be considered in clinical practice, when dealing with chronic inflammatory diseases in young men. As it is known, the chronic inflammation is the main pathophysiologic mechanism in some rheumatological conditions such as spondyloarthritis (SpA), Ankylosing Spondylitis (AS) and Psoriatic Arthritis (PsA). Therefore, it is paramount to be aware if these diseases could impair male fertility, both due to the inflammation or to the treatments needed: we reviewed the literature on the most relevant and recent evidence on male fertility in patients affected by SpA, AS and PsA.

RECENT FINDINGS

Rheumatological inflammatory diseases (included SpA, AS and PsA) could impair the family planning in man life, especially when diagnosed at young age. Moreover, focusing on sperm quality, it seems that a link between sperm quality impairment and a higher disease activity exist. Focusing on therapies, Tumor Necrosis Factor inhibitors showed a safety profile on human male fertility in clinical studies. Recently, a prospective study and two double-blind placebo-controlled trials assessed the impact of methotrexate and Filgotinib on semen parameters, respectively, showing a safety profile of these drugs on human semen quality. However, there are no clinical data on the impact of Interleukin (IL)17 inhibitors(i), IL12-23i and IL23i. Concerning male fertility in SpA, AS and PsA, an unmet clinical need is still present and new studies are needed to understand the association between these diseases and male fertility, and the implication of the therapies used for these diseases. This narrative review provides an overview of the available data on male fertility in patients affected by SpA, AS and PsA.

Pro-inflammatory cytokines and reproductive hormone responses in bucks post-challenge with Mannheimia haemolytica A2 and its outer membrane protein

The lipopolysaccharide (LPS) endotoxin and outer membrane protein (OMP) are among the virulence factors of Gram-negative bacteria responsible for inducing pathogenicity in the infected host. OMP and LPS occur on the outer membrane of M. haemolytica A2, the primary aetiological agent of pneumonic mannheimiosis in small ruminants. While the LPS is known to mediate Gram-negative bacterial infection by activating downstream inflammatory pathways, the potential role of OMP during inflammatory responses remained unclear. Hence, this study determined the effect of the OMP of M. haemolytica A2 on the serum concentration of pro-inflammatory cytokines and the male reproductive hormones (testosterone and Luteinizing Hormone). We randomly assigned twelve bucks to three groups (n = 4 bucks each): Group 1 was challenged with 2 mL PBS buffer (pH 7.0) intranasally; Group 2 received 2 mL of 1.2 X 109 CFU/mL whole M. haemolytica A2 intranasally; and Group 3 received 2 mL of OMP extract obtained from 1.2 X 109 CFU/mL M. haemolytica A2 intramuscularly. Serum samples collected at pre-determined intervals were used for the quantitative determination of the pro-inflammatory cytokines (IL-1β, IL-6, and TNFα) and reproductive hormones (testosterone and LH) using commercial sandwich enzyme-linked immunosorbent assay (ELISA). The serum concentration of IL1β was initially increased within the first-hour post-challenge in Groups 2 and 3, followed by a significant decrease in concentration at 21d and 35d (p < 0.05) in Group 3. Only mild fluctuations in IL-6 occurred in group 2, as opposed to the 1.7-fold rapid increase in TNFα within 2 h post-challenge before decreasing at 6 h. An increase in pro-inflammatory cytokines was accompanied by an acute febrile response of 39.5 ± 0.38 °C (p < 0.05) at 2 h and 40.1 ± 0.29 °C (p < 0.05) at 4 h in Group 2 and Group 3, respectively. Serum testosterone decreased significantly (p < 0.05) in both treatment groups but remained significantly (p > 0.05) lower than in Group 1 throughout the study. There was a moderate negative association between testosterone and IL1β (r = -0.473; p > 0.05) or TNFα (r = -0.527; p < 0.05) in Group 2. Serum LH also showed moderate negative associations with TNFα in Group 2 (r = -0.63; p < 0.05) and Group 3 (r = -0.54; p > 0.05). The results of this study demonstrated that M. haemolytica A2 and its OMP produced marked alterations in serum levels of pro-inflammatory cytokines and male reproductive hormones. The negative correlations between serum testosterone and inflammatory cytokines would suggest the potential role of OMP in causing male infertility by mediating innate inflammatory responses to suppress testosterone production in bucks.

Estimating the role of single-nucleotide polymorphism (rs1800629)-308 G/A of TNF-alpha gene as genetic marker associated with angina pectoris in a sample of Iraqi patients

BACKGROUND

Angina pectoris (AP) occurs when oxygen and other nutrients are insufficient to meet the metabolic needs of the heart muscle. Stable angina is the most common, while the unstable angina is less frequent. Tumor necrosis factor alpha (TNF-alpha) is a pleiotropic cytokine plays a vital function in the immune response regulation. TNF gene cluster contains many polymorphisms; the most commonly investigated polymorphism is the rs1800629 SNP. This SNP, located at - 308 position with regard to the TNF promoter region, replaces guanine (G) with adenine (A), with the allelic types - 308 G/A, and has been linked to a variety of inflammatory condition and autoimmune diseases. The - 308 G/A SNP was investigated in AP and interconnected to the TNF level to figure out the responsibilities of TNF-alpha gene polymorphism in the pathogenesis of AP.

METHOD

The current work design as a case-control study that involves 300 participant divided to 200 patients evaluated as (stable angina n = 100 and unstable angina n = 100) compared with 100 apparently healthy control subjects. The serum level of TNF-alpha was assessed via enzyme-linked immunosorbent assay (ELISA)/sandwich method. The genotype and allele frequency distribution of TNF-alpha rs1800629 gene polymorphism were investigated by TaqMan probe of allelic discrimination method.

RESULTS

The levels of TNF-alpha were significantly higher in patients with stable and unstable angina pectoris in comparison with controls. The deviation from Hardy-Weinberg equilibrium (HWE) of TNF-alpha genotypes was obvious in control and unstable angina pectoris groups. Moreover, the significant differences between patients with AP and controls under the five genetic models consider the association between TNF-alpha (rs1800629) - 308 G/A and AP with OR > 1. However, data analysis of allelic and genotypic of (rs1800629) - 308 G/A revealed higher significantly differences of GG homozygous and GA heterozygous proportions between stable angina patients and control. The A allele was more represented as etiological allele, and G allele was represented as protective allele. The serum levels of TNF-alpha were significantly higher in subjects with genetically mutated AA genotypes than in subjects with wild GG genotypes in the study groups. ROC curve analysis found the best cutoff value of TNF-alpha level was 77.25 pg/ml.

CONCLUSION

As the results, our data observed a linked of TNF-alpha (rs1800629) - 308 G/A genetic variant with angina pectoris patients, and the A allele has been linked to the production or expression of TNF-alpha serum level and represented an etiological factor of angina pectoris.

Intake of ultra-processed foods and asthenozoospermia odds: A hospital-based case-control study

Background

The intake of ultra-processed foods (UPFs) has increased rapidly in recent years. Evidence has suggested that UPFs has adverse effects on several health outcomes. This study aimed to first evaluate the association between the intake of UPFs and asthenozoospermia odds.

Methods

A hospital-based case-control study including 549 cases and 581 controls was performed in the infertility clinics of Shengjing Hospital of China Medical University from June 2020 to December 2020. Dietary intake was assessed using a validated food frequency questionnaire. Food items were categorized by the NOVA classification system based on the degree of processing. Semen parameters were analyzed according to the World Health Organization guidelines.

Results

The highest tertile of UPFs intake (% of total energy intake) was positively associated with the odds of asthenozoospermia (odds ratio [OR] = 1.53; 95% confidence interval [CI]: 1.12, 2.10; P for trend < 0.05), compared with the lowest tertile. Similar patterns were also found in subgroup analyses among participants with age ≥32 years (OR = 1.58; 95% CI: 1.04, 2.40), BMI ≥ 24 kg/m² (OR = 1.52; 95% CI: 1.04, 2.22), ever cigarette smoking (OR = 1.78; 95% CI: 1.14, 2.79), and ever alcohol drinking (OR = 1.65; 95% CI: 1.01, 2.72), and in sensitivity analyses by using absolute amount (g/day) to calculate the intake of UPFs.

Conclusion

Higher consumption of UPFs was positively associated with the odds of asthenozoospermia. More studies are needed to confirm our findings.

Polymorphisms of androgens-related genes and idiopathic male infertility in Turkish men

Androgens, testosterone and dihydrotestosterone (DHT) are endocrine regulators of spermatogenesis and act via androgen receptor (AR). The aim of this study was to investigate the association(s) of AR (CAG repeat length), SRD5A2 (rs523349, V89L) and TNF-α (rs1800629, -308G/A) polymorphisms with idiopathic male infertility in Turkish men. This case-control study consisted of 312 men with idiopathic infertility and 113 fertile men. Polyacrylamide gel electrophoresis (PAGE) or PCR-restriction fragment length polymorphism methods were used for genotyping. The mean AR CAG repeat length was significantly longer in infertile men than in fertile men (p = 0.015). However, there was no significant association between the SRD5A2 genotypes (VV, VL and LL) and the risk of infertility (p = 0.516). The genotype frequency and allele distribution of TNF-α -308G/A polymorphism (GG, GA, AA genotypes and G, A alleles) were not associated with male infertility (p = 0.779 and p = 0.743 respectively). AR CAG repeat expansion might be one of the risk factors for idiopathic male infertility in Turkish men. Further studies investigating the association of male infertility with AR CAG, V89L and -308G/A polymorphisms are warranted to understand the possible associations among them.

Dietary Inflammatory Index and Risk of Asthenozoospermia: A Hospital-Based Case-Controlled Study in China

Background: Evidence of associations between a pro-inflammatory diet and asthenozoospermia risk is limited. We therefore performed a case-controlled study to investigate associations between pro-inflammatory diet using dietary inflammatory index (DII) scores and asthenozoospermia risk in China.

Methods: Our hospital-based case-controlled study comprised 549 incident asthenozoospermia men and 581 healthy controls. All were interviewed at the infertility clinic in Shengjing Hospital of China Medical University from June 2020 to December 2020. DII scores were calculated based on dietary intake which were assessed using a validated food frequency questionnaire. Semen parameters were analyzed according to World Health Organization guidelines. An unconditional logistic regression model was used to estimate odds ratios (ORs) and corresponding 95% confidence intervals (CIs) for asthenozoospermia risk. The lowest tertile served as the reference category for regression analyses.

Results: After adjustment for age in the primary multivariable model, we failed to determine a significant negative association between DII and asthenozoospermia risk (for the highest tertile of DII scores compared to the lowest tertile) (OR = 0.77, 95% CI: 0.57–1.03). Similarly, non-significant associations were also identified in the multivariable model after adjusting for more potential confounders (OR = 0.86; 95% CI: 0.58–1.27). Additionally, in subgroup analyses stratified by age, body mass index, and smoking status, non-significant results were consistent with the main findings.

Conclusions: To our knowledge, this is the first study exploring this particular topic. Our research does not support an association between DII scores and asthenozoospermia risk. Further prospective studies with more DII relevant foods and nutrients are warranted to confirm our findings.

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.

Tumor Necrosis Factor Alpha -308 G/A Single Nucleotide Polymorphism and Risk of Sperm Abnormalities in Iranian Males

BACKGROUND

Signaling molecules such as cytokines regulate spermatogenesis during the maturation of germ cells and sperm apoptosis. Tumor necrosis factor alpha (TNFα) is one of the most-documented cytokines that is involved in spermatogenesis. We investigated the association of the TNFα -308 G/A single nucleotide polymorphism with sperm abnormalities in Iranian males.

MATERIALS AND METHODS

This case-control study included 180 infertile men who re- ferred to Yazd Research and Clinical Center for Infertility and 100 healthy normospermic controls. Infertile men were classified into four groups of azoospermia (n=91), oligospermia (n=26), teratospermia (n=30) and asthenoteratospermia (n=33). After sperm analysis, DNA was extracted from blood and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was carried out for the genotyping of TNFα- 308 G/A.

RESULTS

The A allele was significantly associated with sperm abnormality in our population [(P<0.001, odds ratios (OR) 95% confidence interval (CI)=2.31]. In addition, the A allele was also associated with azoospermia (P<0.001, OR (95% CI)=2.484), oligospermia (P=0.005, OR (95% CI)=2.51) and teratospemia (P<0.001, OR (95% CI)=3.385) but not with asthenoteratospermia (P=0.623).

CONCLUSION

Our data suggest that this single nucleotide polymorphism (SNP) maybe associated with the risk of sperm abnormality in infertile men of Iranian origin.

TGFβ3 (TGFB3) polymorphism is associated with male infertility

Factors affecting the blood-testis barrier function may be involved in testicular damage and male infertility. Two cytokines play an important role in the barrier regulation, namely transforming growth factor beta 3 (TGF-β3) and tumor necrosis factor (TNF-α). The aim of this study was to investigate the potential association between TGF-β3 (TGFB3) and TNF-α (TNF) gene polymorphisms and male infertility. A total of 846 subjects, 423 diagnosed with male infertility and 423 fertile men were enrolled. TGFB3 (rs2268626:T > C, rs3917158:C > T, rs2284792:A > G, rs2268625:T > C, rs3917187:C > T) and TNF (rs1800629:-308G > A) gene polymorphisms were genotyped. No association between TNF genotype and infertility was observed. As for TGFB3, the genotypes distribution was similar in infertile and fertile men. However, rs2284792 minor allele frequency was significantly higher among infertile subjects. Heterozygous rs2284792 AG genotype was associated with increased odds for infertility [OR = 1.40 (95% CI 1.05-1.86), p = 0.021] and similar results were observed for G allele carrier status [OR = 1.40 (95% CI 1.06-1.84), p = 0.017]. Heterozygosity in TGFB3 rs3917158 was also associated with the infertility [OR = 1.37 (95% CI 1.01-1.87), p = 0.041]. The TGFB3 variant genotypes were associated with lower spermatozoa motility parameters in fertile men. The results indicate that variants in TGFB3 gene may be associated with male infertility. However, the findings require further replication and validation.

Analysis of the correlation of CATSPER single nucleotide polymorphisms (SNPs) with idiopathic asthenospermia

PURPOSE

Idiopathic asthenospermia is the most common type of male infertility. Although the mechanisms causing asthenospermia are complex, recent studies have indicated an important role of cation channel of sperm (CATSPER) gene downregulation or abnormality in the etiology of idiopathic asthenospermia.

METHODS

In the present study, 192 patients with idiopathic asthenospermia and 288 healthy controls were enrolled, and a flight mass spectrometry using Sequenom's MassArray biochip system was applied for genotyping 16 CATSPER gene SNPs reported in the human single nucleotide polymorphism (SNP) database.

RESULTS

Our results indicated a correlation between CATSPER1 SNPs and idiopathic asthenospermia. In particular, the exonal SNP rs1893316 in CATSPER1 significantly correlated with idiopathic asthenospermia risk and is a potential important factor in determining an individual's genetic susceptibility to idiopathic asthenospermia.

CONCLUSION

These finding will help to further elucidate the role of CATSPER1 in idiopathic asthenospermia pathogenesis.

TNF-α -308 polymorphisms and male infertility risk: A meta-analysis and systematic review

This study aimed to conduct a systematic review and meta-analysis of prospective studies discussing TNF-α -308 polymorphism and male infertility. This study was conformed to Preferred Reported Items for Systematic Reviews and Meta-Analyses guidelines. PubMed, Embase and Scopus databases were searched to identify relevant studies by two independent reviewers. Hazard ratios were pooled using fixed-effect or random-effects models when appropriate. Q-test was performed to evaluate study heterogeneity and publication bias appraised using funnel plots. The search yielded five studies (three of Caucasians ethnicity and 2 of Asian ethnicity) comprising 2939 men (2262 infertile men and 677 fertile controls). Most of the studied cases were carried out on TNF-α promoter region at positions -308 G/A (four studies) where -308 C/T was dealt with in one study. Overall, significant associations between TNF-α -308 gene polymorphisms and idiopathic male infertility risk were observed (fixed effect: OR = 0.472, 95% CI: 0.378-0.589; P = 0.001; random effect: OR = 0.407, 95% CI: 0.211-0.785; P = 0.007) with robust findings according to sensitivity analyses. Funnel plot inspections did not give evidences of publication bias. A stratified analysis performed for ethnic groups revealed significant association in both Caucasian and Asian populations. It is concluded that there are evidences of associations between TNF-α -308 gene polymorphisms and male infertility risk.

Tumor necrosis factor-308 polymorphism increases the embryo implantation rate in women undergoing in vitro fertilization

STUDY QUESTION

Do TNF-308 and -238 polymorphisms impact the embryo implantation rate after in vitro fertilization (IVF) in women without female infertility factor?

SUMMARY ANSWER

The presence of the TNF-308A allele is associated with high implantation and multiple pregnancy rates in women without known infertility factors after ovarian hyperstimulation with exogenous FSH.

WHAT IS ALREADY KNOWN

Multiple pregnancies are frequent after the use of Assisted Reproductive Technologies. Single embryo transfer (SET) has been proposed as a simple way to prevent these risks. However, the extension of SET indications to patients not selected based on specific criteria is controversial because of reduced pregnancy rates. To date, the predictive value of the parameters used for SET (age, gynecological history of the patient and uterine characteristics) allows a pregnancy rate of ~30%.

STUDY DESIGN, SIZE, DURATION

The potential predictive value of TNF polymorphisms (-308, rs1800629 and -238, rs361525) on implantation rate was evaluated in 424 women requiring IVF due to male fertility factors. This cohort retrospective study was conducted over 4 years in University-affiliated hospitals.

PARTICIPANTS, SETTING, METHODS

The entire patient group included 424 women undergoing intracytoplasmic sperm injection (ICSI) due to male fertility factors without the contribution of any female factor. From among this group, a selected patient group included 120 women with a normal karyotype, age under 38 years, serum follicle-stimulating hormone (Day-3 FSH) levels below 10 IU/l, a long agonist desensitization protocol associated with recombinant FSH treatment and a Caucasian background.

MAIN RESULTS AND THE ROLE OF CHANCE

The TNF-238 polymorphism was not associated with implantation rate. In contrast, the presence of the TNF-308A allele was associated with increased Day 3-E2 levels as well as higher implantation and multiple pregnancy rates after fresh embryo transfer in women from the entire and selected patient groups. Moreover, in the selected patient group, the presence of the TNF-308A allele was also associated with a decrease in the miscarriage rate. The benefit of the TNF-308A allele in predicting implantation rates was not observed after the use of frozen embryos.

LIMITATIONS, REASONS FOR CAUTION

Future studies are needed to evaluate whether the TNF-308A allele might also be a biomarker in women with infertility factors.

WIDER IMPLICATIONS OF THE FINDING

The TNF-308A allele may represent a good candidate for a potential predictive, non-invasive biomarker in the SET strategy. However, its impact should be evaluated in prospective studies.

STUDY FUNDING/COMPETING INTEREST

This study was conducted with financial support from the French Institute for Health and Medical Research (INSERM), Organon France for a FARO (Fond d'Aide à la Recherche Organon) fellowship (to V.T.) and CHU Nice PHRC (PHRC 09-279).There are no competing interests.

Tumor necrosis factor-α gene polymorphism relationship to seminal variables in infertile men

OBJECTIVE

To assess the tumor necrosis factor (TNF)-α gene polymorphism relationship with seminal variables in fertile men (N) and those with asthenozoospermia (A), asthenoteratozoospermia (AT), and oligoasthenoteratozoospermia (OAT).

MATERIALS AND METHODS

A total of 50 infertile men without a female factor who were attending a fertility clinic and 48 fertile men were randomly screened for semen analysis, analysis of the TNF-α promoter region for polymorphism, seminal caspase-9, acrosin activity, α-glucosidase, and reproductive hormones.

RESULTS

The TNF-α GG genotype was present in 83.9%, 72.7%, 66.7%, and 59.5%, the TNF-α AA genotype in 3.2%, 6.8%, 10.4%, and 11.9%, and TNF-α AG genotype in 12.9%, 20.5%, 22.9%, and 28.6% in the N, A, AT, OAT groups, respectively. The occurrence of A allele was significantly greater among infertile patients than among fertile controls (21.6% vs 9.7%; odds ratio 0.388, 95% confidence interval 0.2 to 0.75, P = .005). Men with the TNF-α AA genotype demonstrated a significant decrease in the sperm count, sperm motility, normal sperm morphology, acrosin activity, and seminal α-glucosidase and a significant increase in seminal caspase-9 compared with those with the TNF-α GG genotype.

CONCLUSION

This single nucleotide polymorphism in the TNF-α(-308) gene was associated with significantly increased seminal caspase-9 and a significantly decreased sperm count, sperm motility, normal sperm morphology, acrosin activity, and seminal α-glucosidase.

A single-nucleotide polymorphism of the DAZL gene promoter confers susceptibility to spermatogenic failure in the Taiwanese Han

BACKGROUND

Deleted in AZoospermia-like (DAZL) is an autosomal homologue of Y chromosome-linked DAZ gene located on chromosome 3p24. DAZL is only expressed in the gonads and is critical to germ cell development in different species. However, the regulation of DAZL has not been explored.

METHODS

Reporter assays, electrophoretic mobility shift assays, supershift assays and bisulfate sequencing were used to identify the core promoter region of DAZL. Sequence analysis was used to identify single-nucleotide polymorphisms (SNPs) in the promoter region. A total of 337 infertile men with abnormal semen parameters and 203 fertile men with normal semen parameters were subjected to sequence analysis of the DAZL promoter region.

RESULTS

The DAZL gene core promoter is located 1 kb upstream of the transcription start site. Three SNPs (-792G>A, -669A>C and -309T>C) were identified in our population. Of these three SNPs, -792G>A was more prevalent in the infertile men (P= 0.0005). Quantitative analysis revealed that genotypes of -792G>A had effects on sperm concentration (P= 0.0025) and motility (P= 1.5 × 10(-7)). The G to A substitution was associated with decreased binding of the nuclear respiratory factor-1 (NRF-1) to the promoter region and decreased reporter gene activity.

CONCLUSION

We have identified the core promoter of the human DAZL gene. We also provide preliminary evidence for the role of a novel SNP of the DAZL gene promoter in human spermatogenic failure.

The search for SNPs, CNVs, and epigenetic variants associated with the complex disease of male infertility

Understanding the genetic basis of idiopathic male infertility has long been the focus of many researchers. Numerous recent studies have attempted to identify relevant single nucleotide polymorphisms (SNPs) through medical re-sequencing studies in which candidate genes are sequenced in large numbers of cases and controls in the search for risk or causative polymorphisms. Two major characteristics have limited the utility of the re-sequencing studies. First, reported SNPs have only accounted for a small percentage of idiopathic male infertility. Second, SNPs reported to have an association with male infertility based on gene re-sequencing studies often fail validation in follow-up studies. Recent advances in the tools available for genetic studies have enabled interrogation of the entire genome in search of common, and more recently, rare variants. In this review, we discuss the progress of studies on genetic and epigenetic variants of male infertility as well as future directions that we predict will be the most productive in identifying the genetic basis for male factor infertility based on our current state of knowledge in this field as well as lessons learned about the genetic basis for complex diseases from other disease models.

Single nucleotide polymorphism (SNP) of the endothelial nitric oxide synthase (eNOS) gene (Glu298Asp variant) in infertile men with asthenozoospermia

The objective of this study was to elucidate the missense Glu298Asp polymorphism within exon 7 of the endothelial nitric oxide synthase (eNOS) gene in infertile men with asthenozoospermia and its potential role in sperm motility. In this prospective controlled study conducted in our andrology unit, we investigated the frequency of the 894G>T polymorphism (Glu298Asp variant) within exon 7 of the eNOS gene in 70 infertile men and 60 healthy men. Sperm motion kinetics were assessed with computer-assisted semen analysis. The presence of G>T, a single nucleotide polymorphism (SNP) in exon 7 of the eNOS gene (NCBI SNP cluster rs1799983; GenBank accession number NG_011992; protein accession number NP_000594) was determined by allelespecific polymerase chain reaction followed by restriction fragment length polymorphism analysis. Sequencing analysis was used to confirm the specific genotype. The 894G>T eNOS allele (T) was found at a higher frequency in the patients with asthenozoospermia (60% vs 22.5% in the control group; P = .02). The percentage of progressive motile sperm (grade a + b) was lower in the asthenozoospermic infertile men with the homozygous eNOS (TT) genotype than in the wild-type eNOS (GG) (P = .02) and heterozygous eNOS (GT) genotypes (P = .01). However, the percentage of progressive motile sperm (grade a + b) was higher in the wild-type vs mutant eNOS (TT) (P = .03) and heterozygous eNOS (GT) genotypes (P = .04). Our findings suggest that the T allele encoding for aspartic acid of the eNOS (Glu298Asp) gene may contribute to poor sperm motility.

Quantitative trait analysis suggests human DAZL may be involved in regulating sperm counts and motility

A prospective study was carried out to identify the association of the DAZL (deleted in azoospermia-like) gene with major semen parameters in 210 men with normal and 467 men with abnormal semen parameters. Primer extension analysis for single nucleotide polymorphisms (SNP) of DAZL and quantitative trait analysis on the association of allele/genotype frequencies, linkage disequilibrium characteristics and DAZL haplotypes with semen parameters were investigated. Of five SNP (260A-->G, 386A-->G, 520+34c-->a, 584+28c-->t and 796+36g-->a) screened, 386A-->G was significantly correlated with sperm count (P<0.0001) and motility (P<0.005) and 584+28c-->t was marginally correlated with sperm morphology. After excluding 520+34c-->a, which was not in the Hardy-Weinberg equilibrium, the major haplotypes consisted of four SNP. One haplotype (260A-->G (major allele), 386A-->G (major allele), 584+28c-->t (minor allele) and 796+36g-->a (major allele)) was significantly associated with sperm count (P=0.003) and motility (P=0.04). This study suggests DAZL may be involved in regulating sperm counts, motility and possibly morphology.

Human tumour necrosis factor: physiological and pathological roles in placenta and endometrium

The cytokine tumour necrosis factor alpha (TNF) is a well known member of the TNF superfamily consisting of at least 18 ligands and 29 different receptors involved in numerous cellular processes. TNF signals through two distinct receptors TNFR1 and TNFR2 thereby controlling expression of cytokines, immune receptors, proteases, growth factors and cell cycle genes which in turn regulate inflammation, survival, apoptosis, cell migration, proliferation and differentiation. Since expression of TNF was discovered in amnion and placenta many studies demonstrated the presence of the cytokine and its receptors in the diverse human reproductive tissues. Whereas TNF has been implicated in ovulation, corpus luteum formation and luteolysis, this review focuses on the functions of TNF in human placental, endometrial and decidual cell types of normal tissues and also discusses its role in endometrial and gestational diseases. Physiological levels of the cytokine could be important for balancing cell fusion and apoptotic shedding of villous trophoblasts and to limit trophoblast invasion into maternal decidua. Regulation of the TNF/TNFR system by steroid hormones also suggests a role in uterine function including menstrual cycle-dependent destruction and regeneration of endometrial tissue. Aberrant levels of TNF, however, are associated with diverse reproductive diseases such as amniotic infections, recurrent spontaneous abortions, preeclampsia, preterm labour or endometriosis. Hence, concentrations, receptor distribution and length of stimulation determine whether TNF has beneficial or adverse effects on female reproduction and pregnancy.