Does Sperm SNRPN Methylation Change with Fertility Status and Age? A Systematic Review and Meta-Regression Analysis.

Background: The Small Nuclear Ribonucleoprotein Polypeptide N (SNRPN) gene is a paternally expressed imprinted gene, whose abnormal methylation appears to be associated with syndromes associated with the use of assisted reproductive techniques (ART), such as Angelman and Prader-Willi. Data present in the literature suggest the association between aberrant sperm SNRPN gene methylation and abnormal sperm parameters. The latest meta-analysis on the methylation pattern of this gene in spermatozoa of infertile patients published in 2017 reported a higher degree of methylation in the spermatozoa of infertile patients compared to fertile controls. Objectives: Here we provide an updated and comprehensive systematic review and meta-analysis of the sperm methylation pattern of the SNRPN gene in patients with abnormal sperm parameters/infertility compared to men with normal sperm parameters/fertile. For the first time in the literature, we performed a meta-regression analysis to evaluate whether age or sperm concentration could influence the methylation status of this gene at the sperm level. Methods: This meta-analysis was registered in PROSPERO (n. CRD42023397056). The Preferred Reporting Items for Systematic Reviews and Meta-Analysis Protocols (PRISMA-P) and the MOOSE guidelines for meta-analyses and systematic reviews of observational studies were strictly followed in our meta-analysis. According to our Population Exposure Comparison Outcome (PECO) question, we included data from original articles assessing the levels of SNRPN gene methylation at the sperm level in infertile patients or patients with abnormalities in one or more sperm parameters compared to fertile or normozoospermic men. Results: Only six of 354 screened studies were included in the quantitative synthesis. Our analysis showed significantly higher levels of SNRPN gene methylation in patients compared to controls. However, significant heterogeneity was found between studies. In sensitivity analysis, no studies were sensitive enough to skew the results. The Egger test showed no publication bias. In the meta-regression analysis, the results were independent of age and sperm concentration in the overall population. The same results were found in the control group. However, when analyzing the patient group, a direct correlation was found between SNRPN methylation and age, indicating that the degree of methylation of the SNRPN gene increases with advancing age. Conclusions: Fertility status or abnormality of sperm parameters is associated with a change in the methylation pattern of the SNRPN gene, with higher levels found in infertile patients or those with abnormal sperm parameters compared to fertile men or men with normal sperm parameters. In the group of infertile patients/patients with abnormal sperm parameters, age was directly correlated to the degree of SNRPN methylation, highlighting the presence of a mechanism that explains the age-related altered sperm quality and the risk of ART. Despite some limitations present in the analyzed studies, our results support the inclusion of SNRPN methylation in the genetic panel of prospective studies aimed at identifying the most representative and cost-effective genes to analyze in couples who want to undergo ART.

Testosterone replacement therapy and vascular thromboembolic events: a systematic review and meta-analysis.

ABSTRACT: To evaluate the relationship between testosterone replacement therapy (TRT) and arterial and/or venous thrombosis in patients with pre-treatment total testosterone (TT) <12 nmol l-1, we performed a meta-analysis following the Population Intervention Comparison Outcome model. Population: men with TT <12 nmol l-1 or clear mention of hypogonadism in the inclusion criteria of patients; intervention: TRT; comparison: placebo or no therapy; outcomes: arterial thrombotic events (stroke, myocardial infarction [MI], upper limbs, and lower limbs), VTE (deep vein thrombosis [DVT], portal vein thrombosis, splenic thrombosis, and pulmonary embolism), and mortality. A total of 2423 abstracts were assessed for eligibility. Twenty-four studies, including 14 randomized controlled trials (RCTs), were finally included, with a total of 4027 and 310 288 hypotestosteronemic male patients, from RCTs and from observational studies, respectively. Based on RCT-derived data, TRT did not influence the risk of arterial thrombosis (odds ratio [OR] = 1.27, 95% confidence interval [CI]: 0.47-3.43, P = 0.64), stroke (OR = 1.34, 95% CI: 0.09-18.97, P = 0.83), MI (OR = 0.51, 95% CI: 0.11-2.31, P = 0.39), VTE (OR = 1.42, 95% CI: 0.22-9.03, P = 0.71), pulmonary embolism (OR = 1.38, 95% CI: 0.27-7.04, P = 0.70), and mortality (OR = 0.70, 95% CI: 0.20-2.38, P = 0.56). Meanwhile, when only observational studies are considered, a significant reduction in the risk of developing arterial thrombotic events, MI, venous thromboembolism, and mortality was observed. The risk for DVT remains uncertain, due to the paucity of RCT-based data. TRT in men with TT <12 nmol l-1 is safe from the risk of adverse cardiovascular events. Further studies specifically assessing the risk of DVT in men on TRT are needed.

Predictive role of 17α-hydroxy-progesterone serum levels of response to follicle-stimulating hormone in patients with abnormal sperm parameters.

OBJECTIVES: To study the possible role of serum 17α-hydroxy-progesterone (17αOH-P) levels in predicting favorable responses to follicle-stimulating hormone (FSH) administration in patients with normal serum FSH levels and idiopathic abnormal sperm parameters. DESIGN: Prospective cohort study. SETTING: University-affiliated fertility center. PATIENTS: Fifty patients with oligozoospermia, asthenozoospermia, and/or teratozoospermia and normal serum levels of gonadotropins and total testosterone (TT). INTERVENTION: Treatment with exogenous FSH is administered subcutaneously at a dose of 150 IU 3 times a week for 3 consecutive months. MAIN OUTCOME MEASURE(S): Luteinizing hormone levels, FSH levels, TT levels, 17αOH-P levels, testicular volume, conventional sperm parameters, and seminal spermatid concentration were evaluated before and after therapy. To evaluate the predictive role of pretreatment serum 17αOH-P levels on FSH responsiveness, the doubling of sperm concentration at the end of the FSH administration was considered a positive outcome. RESULTS: After therapy, patients showed a significant increase in sperm concentration, total sperm count (TSC), progressive motility, percentage of normal forms, FSH levels, TT levels, and testicular volume. There was a negative correlation between pretreatment 17αOH-P levels and the posttreatment increase in sperm concentration, TSC, progressive motility, and normal morphology, and a positive correlation with the posttreatment increase in spermatids. Predictive analysis showed that 17αOH-P levels (<1.18 ng/mL) foretold a doubling of sperm concentration with a sensitivity of 90.0% and a specificity of 73.3%, and of TSC with a sensitivity of 91.3% and a specificity of 81.48%. CONCLUSION: The results of this study suggest that pretreatment serum levels of 17αOH-P, a marker of steroidogenic function, appear to be able to predict the success of subcutaneous administration of exogenous FSH in terms of spermatogenesis improvement. Receiver operating characteristic curves indicated that 17αOH-P levels (<1.18 ng/mL) predict a doubling of sperm concentration and TSC after exogenous FSH administration to patients with idiopathic abnormal sperm parameters and normal gonadotropin levels.

Genetic Analysis of Patients with Congenital Hypogonadotropic Hypogonadism: A Case Series.

Congenital hypogonadotropic hypogonadism (cHH)/Kallmann syndrome (KS) is a rare genetic disorder with variable penetrance and a complex inheritance pattern. Consequently, it does not always follow Mendelian laws. More recently, digenic and oligogenic transmission has been recognized in 1.5-15% of cases. We report the results of a clinical and genetic investigation of five unrelated patients with cHH/KS analyzed using a customized gene panel. Patients were diagnosed according to the clinical, hormonal, and radiological criteria of the European Consensus Statement. DNA was analyzed using next-generation sequencing with a customized panel that included 31 genes. When available, first-degree relatives of the probands were also analyzed to assess genotype-phenotype segregation. The consequences of the identified variants on gene function were evaluated by analyzing the conservation of amino acids across species and by using molecular modeling. We found one new pathogenic variant of the CHD7 gene (c.576T>A, p.Tyr1928) and three new variants of unknown significance (VUSs) in IL17RD (c.960G>A, p.Met320Ile), FGF17 (c.208G>A, p.Gly70Arg), and DUSP6 (c.434T>G, p.Leu145Arg). All were present in the heterozygous state. Previously reported heterozygous variants were also found in the PROK2 (c.163del, p.Ile55*), CHD7 (c.c.2750C>T, p.Thr917Met and c.7891C>T, p.Arg2631*), FLRT3 (c.1106C>T, p.Ala369Val), and CCDC103 (c.461A>C, p.His154Pro) genes. Molecular modeling, molecular dynamics, and conservation analyses were performed on three out of the nine variants identified in our patients, namely, FGF17 (p.Gly70Arg), DUSP6 (p.Leu145Arg), and CHD7 p.(Thr917Met). Except for DUSP6, where the L145R variant was shown to disrupt the interaction between ß6 and ß3, needed for extracellular signal-regulated kinase 2 (ERK2) binding and recognition, no significant changes were identified between the wild-types and mutants of the other proteins. We found a new pathogenic variant of the CHD7 gene. The molecular modeling results suggest that the VUS of the DUSP6 (c.434T>G, p.Leu145Arg) gene may play a role in the pathogenesis of cHH. However, our analysis indicates that it is unlikely that the VUSs for the IL17RD (c.960G>A, p.Met320Ile) and FGF17 (c.208G>A, p.Gly70Arg) genes are involved in the pathogenesis of cHH. Functional studies are needed to confirm this hypothesis.

Advances in non-hormonal pharmacotherapy for the treatment of male infertility: the role of inositols.

INTRODUCTION: Several antioxidants are available for the treatment of male infertility. Although the benefit of myo-inositol (MYO) and D-chiro-inositol (DCI) for female infertility is recognized, their role in male infertility is a matter of debate. AREAS COVERED: The authors review the impact that treatment with MYO and/or DCI may have on conventional and bio-functional sperm parameters [mitochondrial membrane potential (MMP), sperm chromatin compactness, and sperm DNA fragmentation (SDF)], seminal oxidative stress (OS), and pregnancy, miscarriage, and live birth rates, and the possible mechanisms involved. Furthermore, the authors gather evidence on the effects of MYO and/or DCI on sperm function in vitro. EXPERT OPINION: MYO can improve sperm count, motility, capacitation, acrosome reaction, and MMP. No data are currently available on the effects of DCI in vivo. Both MYO and DCI ameliorate sperm motility and MMP in vitro. Therefore, the use of inositols should be preferred in patients with idiopathic asthenozoospermia, especially in case of impaired sperm mitochondrial function. Due to their insulin-sensitizing action, a role for these molecules may be envisaged for the treatment of infertility caused by carbohydrate metabolism derangement.

Temporal Trend of Conventional Sperm Parameters in a Sicilian Population in the Decade 2011-2020.

OBJECTIVE: To evaluate the changes of conventional sperm parameters in men who referred to an andrology reference center in Catania (Eastern Sicily, Italy) in the decade 2011-2020. METHODS: For this purpose, we selected-retrospectively and randomly-the reports of 1409 semen analyses performed according to the 2010 WHO criteria. Data on sperm concentration, total sperm count, progressive sperm motility, and percentage of normal forms were analyzed using linear regression of the raw and logarithmic-transformed data. The sperm parameters were subsequently pooled in two five-year periods (2011-2015 and 2016-2020) and compared with each other. Finally, the influence of the city of residence was assessed on five-year pooled data. MAIN RESULTS: A slight but non-significant decline of total sperm count (-2.26 million/year; p = 0.065) and the percentage of spermatozoa with normal morphology (-0.08%/year; p = 0.057) was observed. In contrast, a significant increase of progressive sperm motility (+0.28%/year; p = 0.008) over time was found. The total sperm count of the quinquennium 2016-2020 was significantly lower. and an upward trend of progressive sperm motility was found. compared to the years 2011-2015. No changes in sperm concentration and morphology occurred in the years 2011-2015 vs. 2016-2020. Sperm conventional parameters did not differ when the five-year pooled data were analyzed according to the town of residence. CONCLUSIONS: Divergent trends of total sperm count and progressive sperm motility over time were found in patients from Eastern Sicily. This may point out the need of assessing whether a time-dependent change of biofunctional sperm parameters occurs to really understand the trend of sperm quality over time.