Deficiency in Outer Dense Fiber 1 Is a Marker and Potential Driver of Idiopathic Male Infertility.
ABSTRACT: Globally, ?1 in 15 men of reproductive age are infertile, yet the precise mechanisms underlying their gamete failure are unknown. Although a semen analysis is performed to determine fertilizing potential, the diagnostic suitability of this analysis has been questioned in several reports, as many men, classified as infertile according to their semen analysis, subsequently turn out to be fertile. Herein, we have used a quantitative (phospho)-proteomic analysis, using enrichment on titanium dioxide followed by ion-trap mass spectrometry (LC-MS/MS), to compare the semen of infertile versus fertile males. One protein, namely outer dense fiber 1 (ODF1), was dramatically reduced in infertile males. Using specific antibodies, we then screened the gametes of a cohort of suspected infertile men and demonstrated a reduction in the amount of ODF1 compared with fertile controls. Stress treatment of sperm deficient in ODF1 caused the head to decapitate, suggesting why these gametes fail to initiate fertilization. Interestingly, electron micrographs of ODF1-deficient spermatozoa revealed an abnormal connecting piece, indicating several developmental defects with both the implantation plate and the thin laminated fibers. In some cases, the implantation plate appeared to be reduced in size or was overburdened by granular material near the connecting piece. Hence, a strong reduction ODF1 is a marker of idiopathic male infertility and a potential driver of this condition.
Project description:Up to 30% of men with normal semen parameters suffer from infertility and the reason for this is unknown. Altered expression of sperm proteins may be a major cause of infertility in these men. Proteomic profiling was performed on pooled semen samples from eight normozoospermic fertile men and nine normozoospermic infertile men using LC-MS/MS. Furthermore, key differentially expressed proteins (DEPs) related to the fertilization process were selected for validation using Western blotting. A total of 1139 and 1095 proteins were identified in normozoospermic fertile and infertile men, respectively. Of these, 162 proteins were identified as DEPs. The canonical pathway related to free radical scavenging was enriched with upregulated DEPs in normozoospermic infertile men. The proteins associated with reproductive system development and function, and the ubiquitination pathway were underexpressed in normozoospermic infertile men. Western blot analysis revealed the overexpression of annexin A2 (ANXA2) (2.03 fold change; P = 0.0243), and underexpression of sperm surface protein Sp17 (SPA17) (0.37 fold change; P = 0.0205) and serine protease inhibitor (SERPINA5) (0.32 fold change; P = 0.0073) in men with unexplained male infertility (UMI). The global proteomic profile of normozoospermic infertile men is different from that of normozoospermic fertile men. Our data suggests that SPA17, ANXA2, and SERPINA5 may potentially serve as non-invasive protein biomarkers associated with the fertilization process of the spermatozoa in UMI.
Project description:PURPOSE: To verify the prevalence of semen bacterial contamination and whether the contamination could decrease sperm quality. METHODS: Spermiogram, semen culture, and sperm transmission electron microscopy (TEM) analysis were performed. TEM data were elaborated using a mathematical formula that calculates a fertility index (FI)--able to define patients as fertile or infertile--and the percentage of sperm apoptosis, immaturity and necrosis. We aligned the amino acid sequence of beta-tubulin with protein of the most frequent species isolated from semen. RESULTS: Patients were divided according to the contaminating species; in each group, we observed fertile individuals, in whom the semen quality was similar to that of controls and infertile men whose sperm quality was significantly decreased, in terms of motility, FI, apoptosis and necrosis. Partial homology between beta-tubulin and bacterial proteins was observed. CONCLUSION: Sperm bacterial contamination is quite frequent and could contribute to the deterioration of the sperm quality of infertile men.
Project description:Individuals born with low birth weight (LBW) risk cardiometabolic complications later in life. However the impact of LBW on general health status and male reproductive function has been scantly analysed. We investigated the clinical and seminal impact of different birth weights (BW) in white-European men presenting for primary couple's infertility. Demographic, clinical, and laboratory data from 827 primary infertile men were compared with those of 373 consecutive fertile men. Patients with BW ?2500, 2500-4200, and ?4200gr were classified as having LBW, normal (NBW), and high BW (HBW), respectively. Health-significant comorbidities were scored with the Charlson Comorbidity Index (CCI). Testicular volume was assessed with a Prader orchidometer. Semen analysis values were assessed based on 2010 WHO reference criteria. Descriptive statistics and regression models tested associations between semen parameters, clinical characteristics and BW categories. LBW, NBW and HBW were found in 71 (8.6%), 651 (78.7%) and 105 (12.7%) infertile men, respectively. LBW was more frequent in infertile patients than fertile men (p = 0.002). Infertile patients with LBW had a higher rate of comorbidities (p = 0.003), lower mean testicular volume (p = 0.007), higher FSH (p = 0.02) and lower tT levels (p = 0.04) compared to other BW groups. Higher rates of asthenozoospermia (p = 0.02) and teratozoospermia (p = 0.03) were also found in LBW men. At logistic regression models, LBW was univariably associated with pathologic progressive motility (p?0.02) and pathologic sperm morphology (p<0.005). At multivariable logistic regression analysis, LBW achieved independent predictor status for both lower sperm motility and pathologic sperm morphology (all p?0.04). Only LBW independently predicted higher CCI values (p<0.001). In conclusion, we found that LBW was more frequent in infertile than in fertile men. Infertile individuals with LBW showed a higher rate of comorbidities and significantly worse clinical, endocrine and semen parameters compared to other BW groups.
Project description:Low concentrations of nitric oxide (NO) are necessary for the biology and physiology of spermatozoa, but high levels of NO are toxic and have negative effects on sperm functions. Although several studies have considered the relationship between infertility and semen NO concentrations, no study on the effects of asthenospermia treatments such as oral zinc supplementation on concentrations of NO, which are important in fertility, has been reported. Studies have shown that oral zinc supplementation develops sperm count, motility and the physical characteristics of sperm in animals and in some groups of infertile men. The present study was conducted to study the effect of zinc supplementation on the quantitative and qualitative characteristics of semen, along with enzymes of the NO pathway in the seminal plasma of asthenospermic patients.Semen samples were obtained from 60 fertile and 60 asthenozoospermic infertile men of matched age. The subfertile group was treated with zinc sulfate; each participant took two capsules (220 mg per capsule) per day for 3 months. Semen samples were obtained (before and after zinc sulfate supplementation). After liquefaction of the seminal fluid at room temperature, routine semen analyses were performed. The stable metabolites of NO (nitrite) in seminal plasma were measured by nitrophenol assay. Arginase activity and NO synthase activity were measured spectrophotometrically.Peroxynitrite levels, arginase activity, NO synthase activity and various sperm parameters were compared among fertile controls and infertile patients (before and after treatment with zinc sulfate). Peroxynitrite levels and NO synthase activity were significantly higher in the infertile patients compared to the fertile group. Conversely, arginase activity was significantly higher in the fertile group than the infertile patients. Peroxynitrite levels, arginase activity and NO synthase activity of the infertile patient were restored to normal values after treatment with zinc sulfate. Volume of semen, progressive sperm motility percentage and total normal sperm count were increased after zinc supplementation.Treatment of asthenospermic patients with zinc supplementation leads to restored peroxynitrite levels, arginase activity and NO synthase activity to normal values and gives a statistically significant improvement of semen parameters compared with controls.
Project description:PURPOSE: Infertility affects 10-15 % of the population, of which, approximately 40 % is due to male etiology consisting primarily of low sperm count (oligozoospermia) and/or abnormal sperm motility (asthenozoospermia). It has been demonstrated that mtDNA base substitutions can greatly influence semen quality. METHODS: In the present study we performed a systematic sequence analysis of the mitochondrial cytochrome oxidase III (COIII) gene in 31 asthenozoospermic infertile men in comparaison to normozoospermic infertile men (n=33) and fertile men (n=150) from Tunisian population. RESULTS: A novel m.9588G>A mutation was found in the mtDNA sperm's in all asthenozoospermic patients and was absent in the normozoospermic and in fertile men. The m.9588G>A mutation substitutes a highly conserved Glutamate at position 128 to Lysine. In addition, PolyPhen-2 analysis predicted that this variant is "probably damaging".
Project description:PURPOSE: Investigate in what extent sperm transcriptome of infertile men is different from that of fertile individuals. METHODS: Semen samples were collected for determination of sperm parameters as well as for RNA isolation. Gene expression profile was investigated in spermatozoa of 8 infertile and 3 fertile men by microarray analysis using the Affymetrix Chip HG-U133 Plus 2.0. RESULT(S): We observed up to 33-fold reduction expression of genes involved in spermatogenesis and sperm motility. Furthermore, there is an important decrease in expression of genes involved in DNA repair as well as oxidative stress regulation. In this study, we also show a striking drop in expression of histone modification genes. CONCLUSION(S): We found that transcription profile in germ cells of men with idiopathic infertility is different from that of fertile individuals. Interestingly, about 15% of the regulated genes (Eddy Rev Reprod 4:23-30, 1999) play a role in spermatogenesis.
Project description:Oxidative stress (OS) is detrimental to sperm functions, and the oxidation reduction potential (ORP) is a good measure of OS as it considers the balance between oxidants and reductants. Total motile sperm count (TMSC) is viewed as the single most important semen analysis parameter that can predict male infertility severity, and its correlation with ORP has never been undertaken. The objectives of this study were to assess the correlation between ORP and TMSC, to identify the ORP cutoff value based on the TMSC result, and to compare this cutoff value with previously reported ORP cutoff values in literature. One thousand one hundred and sixty-eight infertile patients and 100 fertile controls were enrolled. Demographic and semen data of the participants were retrieved and analyzed. Wilcoxon's rank-sum test compared variables between infertile men and fertile controls; Spearman's correlation assessed the static ORP (sORP)-TMSC relationship for the whole sample and among each group individually. Using a 20×106TMSC threshold, receiver operator characteristic (ROC) analysis determined the sORP cutoff associated with the highest predictive values. TMSC was significantly negatively correlated with sORP across all participants (r = 0.86, P < 0.001), among infertile patients (r = 0.729, P < 0.001), and among fertile controls (r = 0.53, P < 0.001). A 20-million TMSC threshold determined an sORP cutoff value of 2.34 mV/106sperm/ml to be associated with 82.9% sensitivity, 82.8% specificity, 91.5% positive predictive value (PPV), 68.5% negative predictive value (NPV), and 82.9% overall accuracy. Compared with previously reported cutoff values in searched literature, the 2.34 mV/106sperm/ml cutoff value identified in our study yielded the highest overall diagnostic accuracy in the evaluation of infertile men.
Project description:Sperm motility and hence male fertility strictly depends on proper development of the sperm tail and its tight anchorage to the head. The main protein of sperm tail outer dense fibers, ODF1/HSPB10, belongs to the family of small heat shock proteins that function as molecular chaperones. However, the impact of ODF1 on sperm tail formation and motility and on male fecundity is unknown. We therefore generated mutant mice in which the Odf1 gene was disrupted. Heterozygous mutant male mice are fertile while sperm motility is reduced, but Odf1-deficient male mice are infertile due to the detachment of the sperm head. Although headless tails are somehow motile, transmission electron microscopy revealed disturbed organization of the mitochondrial sheath, as well as of the outer dense fibers. Our results thus suggest that ODF1, besides being involved in the correct arrangement of mitochondrial sheath and outer dense fibers, is essential for rigid junction of sperm head and tail. Loss of function of ODF1, therefore, might account for some of the cases of human infertility with decapitated sperm heads. In addition, since sperm motility is already affected in heterozygous mice, impairment of ODF1 might even account for some cases of reduced fertility in male patients.
Project description:Sperm DNA fragmentation (sDF) negatively affects reproduction and is traditionally detected in total sperm population including viable and non-viable spermatozoa. Here, we aimed at exploring the ability of DNA fragmentation to discriminate fertile and subfertile men when detected in viable (viable sDF), non-viable (non-viable sDF), and total spermatozoa (total sDF). We revealed sDF in 91 male partners of infertile couples and 71 fertile men (max 1 year from natural conception) with LiveTUNEL coupled to flow cytometry, able to reveal simultaneously DNA fragmentation and cell viability. We found that the three sDF parameters discriminated fertile and subfertile men with similar accuracy and independently from age and basal semen parameters: AUCs (area under the curves) (95% CI) were: 0.696 (0.615-0.776), p < 0.001 for total sDF; 0.718 (0.640-0.797), p < 0.001 for viable sDF; 0.760 (0.685-0.835), p < 0.001 for non-viable sDF. We also found that total and non-viable but not viable sDF significantly correlated to age and semen quality. In conclusion, the three sDF parameters similarly discriminated fertile and subfertile men. Viable spermatozoa with DNA fragmentation are likely cells able to fertilize the oocyte but failing to properly support subsequent embryo development. Non-viable sDF could be a sign of a subtler damage extended beyond the non-viable cells.
Project description:This study investigated the effects of varicocele on semen parameters in infertile men based on the new 2010 World Health Organization laboratory manual for the examination of human semen. Semen analysis results (volume, sperm count, motility, and morphology) were the primary outcomes. An electronic search to collect the data was conducted using the Medline/PubMed, SJU discover, and Google Scholar databases. We searched articles published from 2010 to August 2015, i.e., after the publication of the 2010 WHO manual. We included only those studies that reported the actual semen parameters of adult infertile men diagnosed with clinical varicocele and contained a control group of either fertile men or normozoospermic men who were not diagnosed with varicocele. Ten studies were included in the meta-analysis, involving 1232 men. Varicocele was associated with reduced sperm count (mean difference: -44.48 × 10  ml-1 ; 95% CI: -61.45, -27.51 × 10  ml-1 ; P < 0.001), motility (mean difference: -26.67%; 95% CI: -34.27, -19.08; P < 0.001), and morphology (mean difference: -19.68%; 95% CI: -29.28, -10.07; P < 0.001) but not semen volume (mean difference: -0.23 ml; 95% CI: -0.64, 0.17). Subgroup analyses indicated that the magnitude of effect was influenced by control subtype but not WHO laboratory manual edition used for semen assessment. We conclude that varicocele is a significant risk factor that negatively affects semen quality, but the observed pooled effect size on semen parameters does not seem to be affected by the WHO laboratory manual edition. Given most of the studies published after 2010 still utilized the 1999 manual for semen analysis, further research is required to fully understand the clinical implication of the 2010 WHO laboratory manual on the association between varicocele and semen parameters.