Fatty acids profiling reveals potential candidate markers of semen quality

Molecular Biomarkers of Canine Reproductive Functions

The aim of the current study is to review potential molecular biomarker substances selected so far as useful for assessing the quality of dog semen. Proteins, lipids, carbohydrates, and ions can serve as molecular biomarkers of reproductive functions (BRFs) for evaluating male reproductive health and identifying potential risk factors for infertility or reproductive disorders. Evaluation of BRF levels in semen samples or reproductive tissues may provide insights into the underlying causes of infertility, such as impaired sperm function, abnormal sperm-egg interaction, or dysfunction of the male reproductive tract. Molecular biomarker proteins may be divided into two groups: proteins that are well-studied, such as A-kinase anchoring proteins (AKAPs), albumins (ALBs), alkaline phosphatase (ALPL), clusterin (CLU), canine prostate-specific esterase (CPSE), cysteine-rich secretory protein 2 (CRISP2), lactotransferrin (LTF), metalloproteinases (MMPs), and osteopontin (OPN) and proteins that are not well-studied. Non-protein markers include lipid-based substances (fatty acids, phosphatidylcholine), carbohydrates (glycosaminoglycans), and ions (zinc, calcium). Assessing the levels of BRFs in semen samples may provide valuable information for breeding management and reproductive assessments in dogs. This review systematizes current knowledge that could serve as a starting point for developing practical tests with the use of biomarkers of canine reproductive functions and their predictive value for assisted reproductive technique outcomes and semen preservation.

Co-exposure to 55 endocrine-disrupting chemicals linking diminished sperm quality: Mixture effect, and the role of seminal plasma docosapentaenoic acid

Isolated effects of single endocrine-disrupting chemicals (EDCs) on male reproductive health have been studied extensively, but their mixture effect remains unelucidated. Previous research has suggested that consuming diet enriched in omega-3 polyunsaturated fatty acids (PUFA) might be beneficial for reproductive health, whether omega-3 PUFA could moderate the effect of EDCs mixture on semen quality remains to be explored. In this study of 155 male recruited from a reproductive health center in China, we used targeted-exposomics to simultaneously measure 55 EDCs in the urine for exposure burden. Regression analyses were restricted to highly detected EDCs (≥55%, n = 34), and those with consistently elevated risk were further screened and brought into mixture effect models (Bisphenol A, ethyl paraben, methyl paraben [MeP], benzophenone-1 [BP1], benzophenone-3, mono(3-carboxypropyl) phthalate [MCPP]). Bayesian Kernel Machine Regression (BKMR) and quantile-based g-computation (QGC) models demonstrated that co-exposure to top-ranked EDCs was related to reduced sperm total (β = -0.18, 95%CI: -0.29 - -0.07, P = 0.002) and progressive motility (β = -0.27, 95%CI: -0.43 - -0.10, P = 0.002), but not to lower semen volume. BP1, MeP and MCPP were identified as the main effect driver for deteriorated sperm motion parameters using mixture model analyses. Seminal plasma fatty acid profiling showed that high omega-3 PUFA status, notably elevated docosapentaenoic acid (DPA, C22:5n-3) status, moderated the association between MCPP and sperm motion parameters (total motility: β = 0.26, 95%CI: 0.01 - -0.51, Pinteraction = 0.047; progressive motility: β = 0.64, 95%CI: 0.23 - 1.05, Pinteraction = 0.003). Co-exposure to a range of EDCs is mainly associated with deteriorated sperm quality, but to a lesser extent on sperm quantity, high seminal plasma DPA status might be protective against the effect. Our work emphasizes the importance of exposomic approach to assess chemical exposures and highlighted a new possible intervention target for mitigating the potential adverse effect of EDCs on semen quality.

Lipidomic Profile of Human Sperm Membrane Identifies a Clustering of Lipids Associated with Semen Quality and Function

Reduced sperm motility and/or count are among the major causes of reduced fertility in men, and sperm membranes play an important role in the spermatogenesis and fertilization processes. However, the impact of sperm lipid composition on male fertility remains under-investigated. The aim of the present study was to perform a lipidomic analysis of human sperm membranes: we performed an untargeted analysis of membrane lipid composition in fertile (N = 33) and infertile subjects (N = 29). In parallel, we evaluated their serum lipid levels. Twenty-one lipids were identified by their mass/charge ratio and post-source decay spectra. Sulfogalactosylglycerolipid (SGG, seminolipid) was the most abundant lipid component in the membranes. In addition, we observed a significant proportion of PUFAs. Important differences have emerged between the fertile and infertile groups, leading to the identification of a lipid cluster that was associated with semen parameters. Among these, cholesterol sulfate, SGG, and PUFAs represented the most important predictors of semen quality. No association was found between the serum and sperm lipids. Dietary PUFAs and SGG have acknowledged antioxidant functions and could, therefore, represent sensitive markers of sperm quality and testicular function. Altogether, these results underline the important role of sperm membrane lipids, which act independently of serum lipids levels and may rather represent an independent marker of reproductive function.

Oxidative stress associated with proteomic and fatty acid profiles of sperm from Nellore bulls at rest†

Sexual rest is a transient condition, which compromises conception rates, characterized by large volumes of ejaculate with high percentages of dead sperm observed in bulls. The biochemical mechanisms leading to this ejaculate pattern are not fully understood. Six adult resting Nellore bulls were submitted to Breeding Soundness Evaluation by four consecutive semen collections through the electroejaculation method during a 30 min period. Each ejaculate had its semen phenotypic parameters; morphology and physical aspects were evaluated. To assess enzymatic activity (superoxide dismutase, catalase, and glutathione S-transferase), lipid peroxidation (concentrations of malondialdehyde and nitric oxide), fatty acid, and proteomic profile aliquots of spermatozoa from the first and fourth ejaculates were used. All sperm parameters differed between the first and fourth ejaculates. Spermatozoa from the first ejaculate showed lower enzymatic activity and a higher concentration of lipid peroxidation markers. Among the 19 identified fatty acids, 52.7% are polyunsaturated. Relative abundance analysis showed that C12:0 and C18:0 fatty acids differed between the first and fourth ejaculates, being the fourth ejaculate richer in spermatozoa. The proteomics analysis identified a total of 974 proteins in both sample groups (first and fourth ejaculates). The majority of identified proteins are related to cellular processes and signaling. Quantitative proteomics showed 36 differentially abundant proteins, 6 up-regulated proteins in the first ejaculate, and 30 up-regulated proteins in the fourth ejaculate. Spermatozoa from bulls at sexual rest have less antioxidant capacity, causing changes in their fatty acid composition and protein profile, which generates the observed sperm pattern and lower fertilization capacity.

The relationship between the intake of dietary fatty acids and minerals with sperm parameters in infertile men

BACKGROUND & AIMS

Infertility has been increasing among Iranian couples. Some epidemiological studies have reported a relationship between infertility and lifestyle patterns, including dietary habits. Our objective was to evaluate the relationship between sperm parameters and the intake of dietary fatty acids and minerals among Iranian infertile men.

METHODS

This cross-sectional was performed on 400 newly diagnosed infertile men at Yazd Reproductive Sciences Institute from July to December 2019. Men whose infertility was confirmed by an andrologist based on the World Health Organization (WHO) criteria were selected. They delivered a semen sample and answered a 168-item semi-quantitative food frequency questionnaire. All data were analyzed using SPSS and STATA software. A p-value of less than 0.5 was considered significant.

RESULTS

In the adjusted model, a significant negative association between sperm motility and the 3rd quartile (Q) of poly-unsaturated fatty acids compared to the 1st quartile) P = 0.02). Also, in the adjusted model, total mobility was significantly increased in the second, third and last quartiles of omega-3 fatty acids compared to the first quartile (P < 0.001, P = 0.02, P < 0.001, respectively). Furthermore, omega-6 fatty acid intake in the last quartile were positively associated with sperm motility (P = 0.01). Moreover, there was a significant association between omega-3 fatty acid intake in the second, third, and last quartiles and sperm normal morphology (P = 0.003, P = 0.018, and P = 0.005, respectively) compared with the first quartile. Further, we observed a significant association between omega-6 fatty acid intake and sperm normal morphology in the last quartile compared with the reference quartile (P = 0.04). Also, the findings showed a significant negative association between the second quartile of sodium and calcium intake and sperm volume compared with the first quartile (P = 0.04, for both) in the adjusted model.

CONCLUSIONS

We concluded that dietary polyunsaturated fatty acid, sodium, and calcium intake are related to sperm morphology, volume, and total motility in Iranian infertile men. However, more research is needed to confirm these relationships and provide evidence to exert these findings into clinical practice.

Quality of testicular spermatozoa improves with changes in composition of culture medium

BACKGROUND

Spermatozoa retrieved from the testis and epididymis are deprived of the beneficial effects of seminal fluid. Thus applying an artificial medium with normal seminal fluid characteristics, known as artificial seminal fluid (ASF), may provide an appropriate condition for improving some sperm parameters in azoospermia. The objective was to investigate the impact of in vitro exposure of testicular and epididymal spermatozoa to ASF on sperm quality. The study was conducted on testicular (n = 20) and epididymal (n = 20) sperm specimens obtained from azoospermic men. Each sample was divided into two equal parts: Part I) for processing and incubation with Ham's F10 medium; Part II) for processing and incubation with ASF.

RESULTS

After 2 h incubation, testicular sperm motility was significantly higher in ASF than in Ham's F10 medium. In comparison to 0 h, mitochondrial membrane potential levels of testicular spermatozoa were significantly higher after 2 h and 24 h in ASF and after 24 h in Ham's F10 medium. Furthermore, the data indicated significantly lower rates of epididymal spermatozoa with high MMP in both media after 24 h. There were no significant differences in the DNA fragmentation index of testicular and epididymal spermatozoa between ASF and Ham's F10 medium at different time points.

CONCLUSION

The results demonstrated that in vitro incubation of testicular spermatozoa improved their motility more effectively than Ham's F10 medium in the short term (2 h), but had no effect on epididymal spermatozoa. Since the physiology of testicular spermatozoa is different from that of ejaculated spermatozoa, it seems that a special environment should be designed and used for each of them.

Association of male fatty acid intake with fecundability among couples planning pregnancy

STUDY QUESTION

To what extent is male fatty acid intake associated with fecundability among couples planning pregnancy?

SUMMARY ANSWER

We observed weak positive associations of male dietary intakes of total and saturated fatty acids with fecundability; no other fatty acid subtypes were appreciably associated with fecundability.

WHAT IS KNOWN ALREADY

Male fatty acid intake has been associated with semen quality in previous studies. However, little is known about the extent to which male fatty acid intake is associated with fecundability among couples attempting spontaneous conception.

STUDY DESIGN, SIZE, DURATION

We conducted an internet-based preconception prospective cohort study of 697 couples who enrolled during 2015-2022. During 12 cycles of observation, 53 couples (7.6%) were lost to follow-up.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Participants were residents of the USA or Canada, aged 21-45 years, and not using fertility treatment at enrollment. At baseline, male participants completed a food frequency questionnaire from which we estimated intakes of total fat and fatty acid subtypes. We ascertained time to pregnancy using questionnaires completed every 8 weeks by female participants until conception or up to 12 months. We used proportional probabilities regression models to estimate fecundability ratios (FRs) and 95% CIs for the associations of fat intakes with fecundability, adjusting for male and female partner characteristics. We used the multivariate nutrient density method to account for energy intake, allowing for interpretation of results as fat intake replacing carbohydrate intake. We conducted several sensitivity analyses to assess the potential for confounding, selection bias, and reverse causation.

MAIN RESULTS AND THE ROLE OF CHANCE

Among 697 couples, we observed 465 pregnancies during 2970 menstrual cycles of follow-up. The cumulative incidence of pregnancy during 12 cycles of follow-up after accounting for censoring was 76%. Intakes of total and saturated fatty acids were weakly, positively associated with fecundability. Fully adjusted FRs for quartiles of total fat intake were 1.32 (95% CI 1.01-1.71), 1.16 (95% CI 0.88-1.51), and 1.43 (95% CI 1.09-1.88) for the second, third, and fourth vs the first quartile, respectively. Fully adjusted FRs for saturated fatty acid intake were 1.21 (95% CI 0.94-1.55), 1.16 (95% CI 0.89-1.51), and 1.23 (95% CI 0.94-1.62) for the second, third, and fourth vs the first quartile, respectively. Intakes of monounsaturated, polyunsaturated, trans-, omega-3, and omega-6 fatty acids were not strongly associated with fecundability. Results were similar after adjustment for the female partner's intakes of trans- and omega-3 fats.

LIMITATIONS, REASONS FOR CAUTION

Dietary intakes estimated from the food frequency questionnaire may be subject to non-differential misclassification, which is expected to bias results toward the null in the extreme categories when exposures are modeled as quartiles. There may be residual confounding by unmeasured dietary, lifestyle, or environmental factors. Sample size was limited, especially in subgroup analyses.

WIDER IMPLICATIONS OF THE FINDINGS

Our results do not support a strong causal effect of male fatty acid intakes on fecundability among couples attempting to conceive spontaneously. The weak positive associations we observed between male dietary fat intakes and fecundability may reflect a combination of causal associations, measurement error, chance, and residual confounding.

STUDY FUNDING/COMPETING INTEREST(S)

The study was funded by the National Institutes of Health, grant numbers R01HD086742 and R01HD105863. In the last 3 years, PRESTO has received in-kind donations from Swiss Precision Diagnostics (home pregnancy tests) and Kindara.com (fertility app). L.A.W. is a consultant for AbbVie, Inc. M.L.E. is an advisor to Sandstone, Ro, Underdog, Dadi, Hannah, Doveras, and VSeat. The other authors have no competing interests to report.

TRIAL REGISTRATION NUMBER

N/A.

PUFAs and Their Derivatives as Emerging Players in Diagnostics and Treatment of Male Fertility Disorders

About 15% of couples worldwide are affected by infertility, with the male factor responsible for approximately 50% of reproductive failures. Male fertility can be influenced by various factors, including an unhealthy lifestyle and diet, often associated with oxidative stress. These changes are frequently the reason for spermatozoan dysfunction, malformations, and lowered count. However, sometimes even with proper semen parameters, fertilization does not occur, and this is referred to as idiopathic infertility. Of particular importance may be molecules contained in the spermatozoan membrane or seminal plasma, such as polyunsaturated fatty acids, including omega-3 (docosahexaenoic and eicosapentaenoic acids) and omega-6 (arachidonic acid) fatty acids and their derivatives (prostaglandins, leukotrienes, thromboxanes, endocannabinoids, isoprostanes), which are vulnerable to the effects of oxidative stress. In the present review, we discuss the influence of these molecules on human male reproductive health and its possible causes, including disrupted oxidative-antioxidative balance. The review also discusses the potential use of these molecules in the diagnostics and treatment of male infertility, with a particular focus on the innovative approach to isoprostanes as biomarkers for male infertility. Given the high occurrence of idiopathic male infertility, there is a need to explore new solutions for the diagnosis and treatment of this condition.

F4-Neuroprostane Effects on Human Sperm

Swim-up selected human sperm were incubated with 7 ng F₄-neuroprostanes (F₄-NeuroPs) for 2 and 4 h. Sperm motility and membrane mitochondrial potential (MMP) were evaluated. The percentage of reacted acrosome was assessed by pisum sativum agglutinin (PSA). Chromatin integrity was detected using the acridine orange (AO) assay and localization of the ryanodine receptor was performed by immunofluorescence analysis. Sperm progressive motility (p = 0.02) and the percentage of sperm showing a strong MMP signal (p = 0.012) significantly increased after 2 h F₄-NeuroP incubation compared to control samples. The AO assay did not show differences in the percentage of sperm with dsDNA between treated or control samples. Meanwhile, a significantly higher number of sperm with reacted acrosomes was highlighted by PSA localization after 4 h F₄-NeuroP incubation. Finally, using an anti-ryanodine antibody, the immunofluorescence signal was differentially distributed at 2 and 4 h: a strong signal was evident in the midpiece and postacrosomal sheath (70% of sperm) at 2 h, whereas a dotted one appeared at 4 h (53% of sperm). A defined concentration of F₄-NeuroPs in seminal fluid may induce sperm capacitation via channel ions present in sperm cells, representing an aid during in vitro sperm preparation that may increase the positive outcome of assisted fertilization.

Regulation of semen quality by fatty acids in diets, extender, and semen

Fatty acids (FAs) are classified into different types according to the degree of hydrocarbon chain saturation, including saturated fatty acids (SFAs), monounsaturated fatty acids (MUFAs), omega-3 polyunsaturated fatty acids (omega-3 PUFAs) and omega-6 polyunsaturated fatty acids (omega-6 PUFAs), which play an important role in maintaining semen quality. This review focuses on the regulation of FAs in semen, diet and extender on semen quality, and expounds its effects on sperm motility, plasma membrane integrity, DNA integrity, hormone content, and antioxidant capacity. It can be concluded that there are species differences in the FAs profile and requirements in sperm, and their ability to regulate semen quality is also affected by the addition methods or dosages. Future research directions should focus on analyzing the FAs profiles of different species or different periods of the same species and exploring suitable addition methods, doses and mechanism of regulating semen quality.

Evaluation of lipidomic change in goat sperm after cryopreservation

The current study aimed to detect the relationship between the spermatozoa cryotolerance and the post-thawed sperm lipidome. Ejaculates from 20 goats, and performed a uniform frozen-thawed procedure in this study. According to the total motility of thawed sperm of goats, semen samples were classified into HF group (High Freezers, n = 8) with >60% total motility and LF group (Low Freezers, n = 8) with < 45% total motility. The lipidomic analysis based on UHPLC-MS/MS was utilized to investigate the relationship between sperm cryotolerance and their lipid metabolites expression. The results showed that the cryotolerance of sperm from different individual goats were in great variation. The total motility of post-thawed sperm in HF group (60.93 ± 2.43%) is significantly higher than that in LF group (34.04 ± 3.41%, P < 0.01). And the post-thawed sperm in HF group exhibited significantly higher plasma membrane (59.06 ± 2.34%) and acrosome integrity (62.93 ± 1.15%) than that in LF group (34.06 ± 4.85%, 44.92 ± 2.19% respectively, P < 0.01). The total of 29 lipid subclasses and 1,133 lipid molecules in the post-thawed goat sperm were identified by lipidomics analysis. The lipid content of thawed sperm in HF group was higher than that in LF group, the lipid profile in HF group was significantly separated from LF group, which indicated that the difference in lipid composition and lipid metabolism mode of sperm between the two groups was existed, especially the expression of phosphatidylcholine and triglyceride molecules. In conclusion, the cryotolerance of sperm from different individual goats were in great variation. Sperm with high cryotolerance may be able to uptake more lipids during cryopreservation. The increase in phosphatidylcholine and triglyceride content of thawed. Sperm may relate to more active lipid anabolic processes.

Seminal plasma metabolomics and lipidomics profiling to identify signatures of pituitary stalk interruption syndrome

Background

Pituitary stalk interruption syndrome (PSIS) is a rare disease caused by congenital pituitary anatomical defects. The underlying mechanisms remain unclear, and the diagnosis is difficult. Here, integrated metabolomics and lipidomics profiling were conducted to study the pathogenesis of PSIS.

Methods

Twenty-one patients with PSIS (BD group) and twenty-three healthy controls (HC group) were enrolled. Basal information and seminal plasma samples were collected. Untargeted metabolomics and lipidomics analyses were performed using ultraperformance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS).

Results

The metabolomics and lipidomics profiles of patients with PSIS changed. The prolactin signaling pathway and biosynthesis of amino acids were the main differentially modified metabolic pathways. The main differentially modified metabolites were triacylglycerols (TGs), phosphatidylethanolamine (PE), sphingomyelin (SM), ceramide (Cer) and phosphatidylcholines (PCs). Pregnenolones and L-saccharopine could achieve a diagnosis of PSIS.

Conclusions

Pregnenolones and L-saccharopine are potential biomarkers for a PSIS diagnosis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13023-022-02408-4.

Oxidation of Polyunsaturated Fatty Acids as a Promising Area of Research in Infertility

In this review, the role of fatty acids (FA) in human pathological conditions, infertility in particular, was considered. FA and FA-derived metabolites modulate cell membrane composition, membrane lipid microdomains and cell signaling. Moreover, such molecules are involved in cell death, immunological responses and inflammatory processes. Human health and several pathological conditions are specifically associated with both dietary and cell membrane lipid profiles. The role of FA metabolism in human sperm and spermatogenesis has recently been investigated. Cumulative findings indicate F₂ isoprostanes (oxygenated products from arachidonic acid metabolism) and resolvins (lipid mediators of resolution of inflammation) as promising biomarkers for the evaluation of semen and follicular fluid quality. Advanced knowledge in this field could lead to new scenarios in the treatment of infertility.

Perspectives on Potential Fatty Acid Modulations of Motility Associated Human Sperm Ion Channels

Human spermatozoan ion channels are specifically distributed in the spermatozoan membrane, contribute to sperm motility, and are associated with male reproductive abnormalities. Calcium, potassium, protons, sodium, and chloride are the main ions that are regulated across this membrane, and their intracellular concentrations are crucial for sperm motility. Fatty acids (FAs) affect sperm quality parameters, reproductive pathologies, male fertility, and regulate ion channel functions in other cells. However, to date the literature is insufficient to draw any conclusions regarding the effects of FAs on human spermatozoan ion channels. Here, we aimed to discern the possible effects of FAs on spermatozoan ion channels and direct guidance for future research. After investigating the effects of FAs on characteristics related to human spermatozoan motility, reproductive pathologies, and the modulation of similar ion channels in other cells by FAs, we extrapolated polyunsaturated FAs (PUFAs) to have the highest potency in modulating sperm ion channels to increase sperm motility. Of the PUFAs, the ω-3 unsaturated fatty acids have the greatest effect. We speculate that saturated and monounsaturated FAs will have little to no effect on sperm ion channel activity, though the possible effects could be opposite to those of the PUFAs, considering the differences between FA structure and behavior.

Fatty Acid Oxidation and Pro-Resolving Lipid Mediators Are Related to Male Infertility

Specialized pro-resolving lipid mediators regulate the resolution of acute inflammation. They are formed by enzymatic oxygenation of polyunsaturated fatty acids and are divided into families including lipoxins, resolvins, protectins, and maresins. Resolvin D1 (RvD1), produced by docosahexaenoic acid, exerts anti-inflammatory and pro-resolving activities. This research aimed to investigate the implication of seminal RvD1 in human infertility. Infertile patients (n° 67) were grouped based on pathological reproductive conditions as idiopathic infertility, varicocele, and leukocytospermia; the fourth group was composed of fertile men (n° 18). Sperm characteristics were evaluated by light microscopy (WHO guidelines) and by transmission electron microscopy (TEM). The seminal levels of RvD1 and F2-isoprostane (F2-IsoPs) were dosed. In twenty men (6 fertile men, 8 with varicocele, 6 with leukocytospermia) seminal phospholipase A2, iron, cholesterol, transferrin, estradiol, ferritin, testosterone, and sperm membrane fatty acids were detected. The results indicated that: (i) RvD1 amount was positively correlated with F2-IsoPs and reduced sperm quality; (ii) RvD1 levels were significantly higher in patients with leukocytospermia, varicocele, and idiopathic infertility compared to fertile men; (iii) RvD1 increased along with other markers of oxidative stress and inflammation as fatty acids content and clinical biomarkers. This study suggests a panel of inflammatory markers and lipid mediators for a diagnosis of inflammatory status and a subsequent appropriate therapeutic approach.

The Association Between Dairy Product Consumption and Asthenozoospermia Risk: A Hospital-Based Case-Control Study

Background: Evidence of an association between dairy product and main related dairy nutrient intake, and the asthenozoospermia risk have been limited and controversial. Methods: A hospital-based case-control study including 549 men with asthenozoospermia and 581 normozoospermic controls was carried out in the infertility clinics of Shengjing Hospital of China Medical University between June, 2020 and December, 2020. Dietary intake was assessed with a validated food frequency questionnaire. According to the World Health Organization guidelines, semen parameters were collected through masturbation and were measured with WLJY9000 instrument and flow cytometry. The daily intake of dairy products and related nutrients was categorized into three groups according to control distribution, and the lowest tertile was used as the reference category. An unconditional multiple logistic regression was used to estimate the odds ratios (ORs) and the corresponding 95% confidence intervals (CIs) for asthenozoospermia risk. Results: After adjustment for potential confounders, we found no statistically significant associations between the intake of total dairy products and asthenozoospermia risk (OR_T3vs.T1 = 1.19, 95%CI = 0.85-1.67). Additionally, we generated null findings regarding the main related nutrients from dairy, including protein (OR_T3vs.T1 = 1.19, 95%CI = 0.85-1.68), fat (OR_T3vs.T1 = 1.28, 95%CI = 0.91-1.80), calcium (OR_T3vs.T1 = 1.20, 95%CI = 0.85-1.68), saturated fatty acids (OR_T3vs.T1 = 1.30, 95%CI = 0.92-1.83), and phosphorous (OR_T3vs.T1 = 1.18, 95%CI = 0.84-1.67), and the asthenozoospermia risk. Of note, after stratification by body mass index (BMI), and the saturated fatty acids consumption from dairy was significantly associated with a higher asthenozoospermia risk (OR_T3vs.T1 = 1.76, 95%CI = 1.01-3.09) among participants with a BMI below 25 kg/m². Conclusion: This study provided limited evidence of an association between the intake of total dairy products and the main related dairy nutrients including protein, fat, calcium, saturated fatty acids, and phosphorus, and the asthenozoospermia risk. Further studies are warranted to confirm our findings in the future.

Do Seminal Isoprostanes Have a Role in Assisted Reproduction Outcome?

F₂-isoprostanes (F₂-IsoPs), stereoisomers of prostaglandin F2α generated by the free radical-induced oxidation of arachidonic acid, have been associated with different male infertility conditions. This study aimed to evaluate the role of seminal isoprostane levels and sperm characteristics in the reproductive outcome and embryo quality of 49 infertile couples. Semen analysis was performed following WHO guidelines. Sperm chromatin maturity was detected using an aniline blue (AB) assay, and DNA integrity was assessed using the acridine orange (AO) test. Seminal F₂-IsoP levels were quantified by gas chromatography/negative ion chemical ionization tandem mass spectrometry (GC/NICI–MS/MS) analysis. Correlations among variables and their impact on in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) outcome were investigated. F₂-IsoP levels are positively correlated with double-stranded DNA sperm (p < 0.001) and negatively correlated with mature sperm chromatin (p < 0.001). Patients with positive outcomes had an increased percentage of sperm with double-stranded DNA, as did patients producing high-quality embryo, who showed higher F₂-IsoP levels compared to those detected in the low-quality embryo group. An intriguing relationship between a mild increase in F₂-IsoP levels, DNA integrity, and embryo quality seems to indicate that the non-enzymatic oxidation of arachidonic acid can be also a marker of metabolic activity in human semen.

High-coverage targeted lipidomics revealed dramatic lipid compositional changes in asthenozoospermic spermatozoa and inverse correlation of ganglioside GM3 with sperm motility

BACKGROUND

It has been previously demonstrated that cholesterol content and cholesterol/phospholipid ratio were significantly higher in asthenozoospermia and oligoasthenoteratozoospermia. The majority of published studies have investigated the fatty acid composition of phospholipids rather than lipids themselves. This study evaluated the lipid composition of asthenozoospermic and normozoospermic spermatozoa, and identified the exact lipid species that correlated with sperm motility.

METHODS

A total of 12 infertile asthenozoospermia patients and 12 normozoospermia subjects with normal sperm motility values were tested for semen volume, sperm concentration, count, motility, vitality and morphology. High-coverage targeted lipidomics with 25 individual lipid classes was performed to analyze the sperm lipid components and establish the exact lipid species that correlated with sperm motility.

RESULTS

A total of 25 individual lipid classes and 479 lipid molecular species were identified and quantified. Asthenozoospermic spermatozoa showed an increase in the level of four lipid classes, including Cho, PE, LPI and GM3. A total of 48 lipid molecular species were significantly altered between normozoospermic and asthenozoospermic spermatozoa. Furthermore, the levels of total GM3 and six GM3 molecular species, which were altered in normozoospermic spermatozoa versus asthenozoospermic spermatozoa, were inversely correlated with sperm progressive and total motility.

CONCLUSIONS

Several unique lipid classes and lipid molecular species were significantly altered between asthenozoospermic and normozoospermic spermatozoa, revealing new possibilities for further mechanistic pursuits and highlighting the development needs of culture medium formulations to improve sperm motility.

F4-Neuroprostanes: A Role in Sperm Capacitation

F₄-neuroprostanes (F₄-NeuroPs), derived from the oxidative metabolization of docosahexaenoic acid (DHA), are considered biomarkers of oxidative stress in neurodegenerative diseases. Neurons and spermatozoa display a high DHA content. NeuroPs might possess biological activities. The aim of this in vitro study was to investigate the biological effects of chemically synthetized 4-F_4t-NeuroP and 10-F_4t-NeuroP in human sperm. Total progressive sperm motility (p < 0.05) and linearity (p = 0.016), evaluated by a computer-assisted sperm analyzer, were significantly increased in samples incubated with 7 ng F₄-NeuroPs compared to non-supplemented controls. Sperm capacitation was tested in rabbit and swim-up-selected human sperm by chlortetracycline fluorescence assay. A higher percentage of capacitated sperm (p < 0.01) was observed in samples incubated in F₄-NeuroPs than in the controls. However, the percentage of capacitated sperm was not different in F₄-NeuroPs and calcium ionophore treatments at 2 h incubation. The phosphorylated form of AMPKα was detected by immunofluorescence analysis; after 2 h F₄-NeuroP incubation, a dotted signal appeared in the entire sperm tail, and in controls, sperm were labeled in the mid-piece. A defined level of seminal F₄-NeuroPs (7 ng) showed a biological activity in sperm function; its addition in sperm suspensions stimulated capacitation, increasing the number of sperm able to fertilize.

THE EFFECT OF CONSUMING AVOCADO (Persea americana) ON MICE (Mus musculus) SPERM QUALITY

The nutrients such as protein and vitamin are proven to improve the sperm quality. One nutrient rich fruit is avocado round green variety, which contains vitamins A, C and E higher than other varieties. This study aimed to determine the effect of consuming avocado on the mice sperm quality. This experimental study was using a Completely Randomized Design with four treatments, each with eight replications. Avocado dosage treatments were control, 75 % w/v, 100% w/v, and 133% w/v , with the number of mice were 32 age four weeks. Avocado was given three times a day, each 0.5 mL for six weeks besides the main food. The observed response was the sperm quality including number, motility and morphology. Sperm was taken from the epididymis after the mice were killed by cervical dislocation method. Sperm was made a suspension using 0.9% NaCl solution and a smear preparation to observe the sperm morphology while staining with basic stain crystal violet. The sperm quality was observed by Neubauer's counting rooms through a multimedia microscope. Data was analyzed using Kurskal Wallis test for the sperm number and Anova test for motility and morphological responses. The result showed that avocado had a significant influence for reproductive health, particularly for increasing spermatozoa quality, including concentration, motility and morphology of sperm. The higher dose of avocado given the higher quantity and quality of sperm resulted.

Seminal Plasma Lipidomics Profiling to Identify Signatures of Kallmann Syndrome

BACKGROUND

Kallmann syndrome (KS) is a rare developmental disorder. Our previous metabolomics work showed substantial changes in linoleic acid and glycerophospholipid metabolism in KS. Here, we performed targeted lipidomics to further identify the differential lipid species in KS.

METHODS

Twenty-one patients with KS (treatment group) and twenty-two age-matched healthy controls (HC, control group) were enrolled. Seminal plasma samples and medical records were collected. Targeted lipidomics analysis of these samples was performed using ultraperformance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS).

RESULTS

Lipidomics profiling of patients with KS and the HCs showed clear separation in the orthogonal projections to latent structures-discriminant analysis (OPLS-DA). There were many differential lipids identified, with the main differential lipid species being triacylglycerols (TAGs), phosphatidylcholines (PCs) and phosphatidylethanolamine (PE).

CONCLUSIONS

The lipidomics profile of patients with KS changed. It was also determined that TAGs, PCs and PE are promising biomarkers for KS diagnosis. To our knowledge, this is the first report to analyze lipidomics in men with Kallmann syndrome.

Lipidomic markers of sperm cryotolerance in cattle

The objective of the current study was to determine the fatty acid composition of sperm from Holstein bulls with different freezability (Good and Poor; n = 12). Fatty acids were extracted from frozen sperm in 1:2 (v/v) chloroform-methanol solvent, fractionated into neutral and polar fractions, and composition determined by gas chromatography-mass spectrometry. Thirty-four fatty acids were quantified and their concentrations and percentages within each lipid fraction were calculated. Overall, saturated fatty acids (SFA) were predominant, accounting for 71 to 80% of fatty acids in neutral and polar lipid factions. There were marked differences in fatty acid composition between the lipid fractions (P < 0.001). The branched chain fatty acid (BCFA) concentration (15 to 18 µg) was almost twice as much as polyunsaturated fatty acids (PUFA) concentration found in the polar lipid fraction (8 to 9 µg; P < 0.001). Sperm with different freezability phenotypes only had a few differences in 22:0, 18:1 cis 9, and 14:0 13-methyl fatty acids (P ≤ 0.011). These results are significant because they reveal key understandings of fatty acid composition of sperm membrane and lay a foundation for the manipulation of membrane integrity, fluidity, and stability to advance the assisted reproductive technologies.

FTIR Spectroscopy to Reveal Lipid and Protein Changes Induced on Sperm by Capacitation: Bases for an Improvement of Sample Selection in ART

Although being a crucial step for Assisted Reproduction Technologies (ART) success, to date sperm selection is based only on morphology, motility and concentration characteristics. Considering the many possible alterations, there is a great need for analytical approaches allowing more effective sperm selections. The use of Fourier Transform Infrared (FTIR) may represent an interesting possibility, being able to reveal many macromolecular changes in a single measurement in a nondestructive way. As a proof of concept, in this observational study, we used a FTIR approach to reveal features related to sperm quality and chemical changes promoted by in vitro capacitation. We found indication that α-helix content is increased in capacitated sperm, while high percentages of the β-structures seem to correlate to poor-quality spermatozoa. The most interesting observation was related to the lipid composition, when measured as CH₂/CH₃ vibrations (ratio 2853/2870), which resulted in being strongly influenced by capacitation and well correlated with sperm motility. Interestingly, this ratio is higher than 1 in infertile samples, suggesting that motility is related to sperm membranes stiffness and lipid composition. Although further analyses are requested, our results support the concept that FTIR can be proposed as a new smart diagnostic tool for semen quality assessment in ART.

Proton MR Spectroscopy in Assessing the Biochemical Milieu of Human Testes

Proton magnetic resonance spectroscopy (MRS), considered a connection between metabolism and anatomic and functional information provided by standard MRI, gives information on various tissue metabolites and their pathologic changes. Recently, proton MRS has been added as an adjunct tool to the multiparametric protocol of scrotal MRI, providing a new insight into the extremely complex biochemical milieu of normal and abnormal testes. This article reviews proton MR spectra of normal testes, showing age and bilateralism dependence. Disturbances of various metabolic pathways in testes of infertile men resulting in alterations of metabolite peaks are discussed. Preliminary data on proton MR spectra of testicular mass lesions are presented. LEVEL OF EVIDENCE: 5. TECHNICAL EFFICACY STAGE: 5.

Fatty Acid Profile and Metabolism Are Related to Human Sperm Parameters and Are Relevant in Idiopathic Infertility and Varicocele

Objectives

Fatty acids (FA) modulate oxidative stress, reactive oxygen species (ROS) production, and inflammatory processes in spermatogenesis.

Methods

The amount of 17 different FAs and the level of F₂-isoprostanes (F₂-IsoPs) and cytoplasmic phospholipase A₂ (cPLA₂) were compared and correlated to sperm characteristics; these last ones were evaluated by light and electronic microscopy in varicocele and idiopathic infertile patients.

Results

Total n-3 polyunsaturated acids (PUFAs) and docosahexaenoic acid (DHA), one of the n-3 PUFAs, were significantly reduced in idiopathic infertile men compared to controls (P < 0.05). In the whole studied population, oleic acid and total monounsaturated acids (MUFAs) correlated negatively with sperm concentration, progressive motility, normal morphology, vitality, and fertility index and positively with sperm necrosis. Eicosapentaenoic acid (EPA) amount was positively correlated with the percentage of sperm necrosis and cPLA₂ level and negatively with sperm concentration. Sperm vitality was negatively correlated with the saturated fatty acids (SFAs). In infertile groups, cPLA₂ was negatively correlated with DHA and n-3 PUFAs (both P < 0.05) and positively with EPA (P < 0.05). In the varicocele group, sperm vitality was negatively correlated with palmitoleic acid and total n-6 PUFAs (P < 0.05); sperm apoptosis was positively correlated with the total SFA percentage (P < 0.05).

Conclusions

FA composition in sperm membrane and the metabolism of sperm FAs are interrelated parameters, both relevant in sperm maturation processes and fertility.

Cutting-Edge Evaluation of Male Infertility

A male factor is a contributor in 50% of cases of infertility. Although assisted reproductive techniques can often bypass the need to improve semen parameters, the evaluation of the infertile man remains critical. Current methods for evaluating the infertile man are discussed, beginning with the basic workup that all suspected infertile men should undergo, followed by subsequent evaluation steps. Although the fundamental components of the evaluation have remained consistent, several new tools are available to assist in identifying the underlying etiology. As our understanding of male fertility expands, the technologies available to diagnose and ultimately treat it continue to evolve.

Relevance of seminal F2-dihomo-IsoPs, F2-IsoPs and F4-NeuroPs in idiopathic infertility and varicocele

The aim of this paper was to investigate the relevance of isoprostanoids i.e., F₂-isoprostanes (F₂-IsoPs), F₄-neuroprostanes (F₄-NeuroPs) and F₂-dihomo-isoprostanes (F₂-dihomo-IsoPs) in semen quality. Isoprostanoid levels were detected in semen of fertile and infertile men with varicocele or idiopathic infertility. Semen quality was assessed by light microscopy and transmission electron microscopy; the relationships between isoprostanes and semen parameters were also explored. F₂-IsoPs levels were significantly different in the varicocele group compared to idiopathic infertile group and fertile men (P < 0.01 and P < 0.001 respectively). Moreover, F₂-dihomo-IsoP values were significantly higher in varicocele group respect to fertile men (P < 0.05). No significant statistical differences were found regarding F₄-NeuroP concentrations. In the whole population, F₂-IsoPs positively correlated with F₂-dihomo-IsoPs and both isoprostanoids showed a positive correlation with immaturity and a negative correlation with sperm motility. F₂-IsoP levels were positively correlated with the percentage of immaturity in infertile varicocele groups (P < 0.01) whereas a significant relationship between F₄-NeuroP values and the percentage of sperm necrosis was shown in idiopathic infertility group (P < 0.01). A significant negative correlation of F₄-NeuroPs with sperm morphology was detected in infertile varicocele subjects (P < 0.05). This study suggests that isoprostanoid semen levels appear to be associated with male infertility being related to the sperm quality and confirming the important role of fatty acids profiling in human sperm maturation.

Relevance of Fatty Acids to Sperm Maturation and Quality

Almost 50% of infertility cases are associated with human male infertility. The sperm membrane is a key structure influencing sperm morphology and function in normal and pathological conditions. The fatty acid profile determines the performance not only of sperm motility but also of acrosomal reaction and sperm-oocyte fusion. This review presents available knowledge on the role of fatty acid composition in human sperm and spermatogenesis and discusses the influence of dietary fatty acids on the sperm fatty acid profile. Recent studies in biological sciences and clinical researches in this field are also reported. The topic object of this review has potential application in medicine by identifying potential causes of infertility.

Alteration of Cholesterol Sulfate/Seminolipid Ratio in Semen Lipid Profile of Men With Oligoasthenozoospermia

The reduction of sperm motility and count, or oligoasthenozoospermia, is one of the major causes of reduced fertility or infertility in men. Lipid composition of spermatozoa is important in determining their functional characteristics, in particular on motility, acrosomal exocytosis or fusogenic properties of the sperm. Here we investigated the levels of semen lipids in 11 infertile patients with severe oligoasthenozoospermia and 9 normozoospermic subjects with normal motility values. Sperm polar and neutral lipids were analyzed by thin-layer chromatography (TLC) and matrix-assisted laser desorption and ionization time-of-flight mass spectrometry (MALDI-TOF/MS). Semen of patients with oligoasthenozoospermia showed a reduction of the degree of fatty acid unsaturation in the phospholipids chains that might affect the membrane fluidity. Furthermore, a significant higher cholesterol sulfate/seminolipid ratio was found in semen of oligoasthenozoospermic patients than in subjects with normal motility values, suggesting a critical role of sulfolipids in semen quality. The results may facilitate the understanding of the role of lipids on male fertility and offer interesting perspectives to find innovative treatments for oligoasthenozoospermia.

Uncovering sperm metabolome to discover biomarkers for bull fertility

Background

Subfertility decreases the efficiency of the cattle industry because artificial insemination employs spermatozoa from a single bull to inseminate thousands of cows. Variation in bull fertility has been demonstrated even among those animals exhibiting normal sperm numbers, motility, and morphology. Despite advances in research, molecular and cellular mechanisms underlying the causes of low fertility in some bulls have not been fully elucidated. In this study, we investigated the metabolic profile of bull spermatozoa using non-targeted metabolomics. Statistical analysis and bioinformatic tools were employed to evaluate the metabolic profiles high and low fertility groups. Metabolic pathways associated with the sperm metabolome were also reported.

Results

A total of 22 distinct metabolites were detected in spermatozoa from bulls with high fertility (HF) or low fertility (LF) phenotype. The major metabolite classes of bovine sperm were organic acids/derivatives and fatty acids/conjugates. We demonstrated that the abundance ratios of five sperm metabolites were statistically different between HF and LF groups including gamma-aminobutyric acid (GABA), carbamate, benzoic acid, lactic acid, and palmitic acid. Metabolites with different abundances in HF and LF bulls had also VIP scores of greater than 1.5 and AUC- ROC curves of more than 80%. In addition, four metabolic pathways associated with differential metabolites namely alanine, aspartate and glutamate metabolism, β-alanine metabolism, glycolysis or gluconeogenesis, and pyruvate metabolism were also explored.

Conclusions

This is the first study aimed at ascertaining the metabolome of spermatozoa from bulls with different fertility phenotype using gas chromatography-mass spectrometry. We identified five metabolites in the two groups of sires and such molecules can be used, in the future, as key indicators of bull fertility.

The influence of omega-3 fatty acids on semen quality markers: a systematic PRISMA review

BACKGROUND

Infertility affects about 15% of all couples worldwide. Male factors such as decreased semen quality contribute to around 40% of the cases. Recent reviews have shown that different foods and nutrients may improve semen quality.

OBJECTIVES

We conducted a systematic review in order to investigate whether intake of omega-3 fatty acids can improve semen quality markers.

MATERIALS AND METHODS

A systematic search of PubMed, Embase, and Cochrane was conducted in adherence with the PRISMA guideline from the earliest available online indexing year to October 2018. Keywords related to male fertility or infertility was combined with words describing omega-3 fatty acids and dietary fish intake. RCTs and observational studies on infertile and fertile men were included. Studies were considered eligible if they met the inclusion criteria, evaluated either the effect of omega-3 fatty acids or dietary fish intake and had semen quality as primary outcome.

RESULTS

Thousand and seventy four records were screened, and sixteen studies were ultimately included. Fourteen of the included studies found an improvement or association between omega-3 and at least one semen quality marker. As the studies were very inhomogeneous in participants (fertile/infertile, age, BMI, ethnicity etc), no meta-analysis was performed.

DISCUSSION

The findings in this review are limited by the few available RCTs. Furthermore, RCTs were very heterogenetic according to study population, sample size, dosage of omega-3, and durations of follow up. Results from the observational studies might have been affected by recall bias and confounded by lifestyle factors.

CONCLUSION

Based on the findings in this review, omega-3 supplements and dietary intake of omega-3 might improve semen quality parameters in infertile men and men from couples seeking fertility treatment. However, more research is required in order to fully clarify the effect of omega-3 on semen quality and research with fecundity as end point is needed.

Impact of Paternal Age on Seminal Parameters and Reproductive Outcome of Intracytoplasmatic Sperm Injection in Infertile Italian Women

Background: We conducted a retrospective study on a cohort of couples attending the Department of Andrology and Reproductive Physiopathology at Sandro Pertini Hospital in Rome for Intracytoplasmatic Sperm Injection (ICSI)-assisted reproduction programs. Some of the couples included in the study underwent more than one ICSI cycle. Between January 2015 and April 2017. Objective: To evaluate whether the advancing of the paternal age may have effect on the seminal parameters, thus negatively affecting the embryo formation, development and quality, as well as the pregnancy rate. Materials and Methods: Five hundred and forty three ICSI cycles were performed on 439 couples undergoing Assisted Reproductive Technologies (ART). Patients were subdivided into three male and three female age groups having similar size: Men: ≤38 years (MI), 39-43 years (MII), ≥44 years (MIII). Women: ≤35 years (FI), 36-40 years (FII),≥41 years (FIII). Discussion and Conclusion: Male age groups did not reveal any statistical significant differences in any age-related semen parameters. We also confirmed a statistical significant increase in the pregnancy rate of couples with older partner age difference and younger female. We found that the advanced male age increases the probability of obtaining one or no type A embryo (NA≤1), which was almost doubled in the MIII group in comparison with MI, suggesting a negative effect of male age on the efficacy of the reproductive outcome in terms of a reduced number of type A embryos. Such an effect does not seem related to semen parameters and may deserve further investigations.

Docosahexaenoic acid in the treatment of male infertility

Literature review is devoted to the analysis of modern data on the use of docosahexaenoic acid in the treatment of male infertility. A brief description of modern ideas about the possible causes of male infertility (a disturbance of function of the cell membrane and genetic damage of sperm) was conducted. The data on the anti-inflammatory properties of omega-3 polyunsaturated fatty acids are described in detail. The bioavailability of docosahexaenoic acid and the choice of drugs containing it for the treatment of male infertility are discussed. Increasing the content of polyunsaturated fatty acids, in particular docosahexaenoic acid, in the sperm membrane was associated with higher ejaculate quality. Therapy with the use of these substances led to the improvement of standard indicators of semen and a decrease in the proportion of sperm with fragmented DNA.

ELOVL4: Very long-chain fatty acids serve an eclectic role in mammalian health and function

ELOngation of Very Long chain fatty acids-4 (ELOVL4) is an elongase responsible for the biosynthesis of very long chain (VLC, ≥C28) saturated (VLC-SFA) and polyunsaturated (VLC-PUFA) fatty acids in brain, retina, skin, Meibomian glands, and testes. Fascinatingly, different mutations in this gene have been reported to cause vastly different phenotypes in humans. Heterozygous inheritance of seven different mutations in the coding sequence and 5' untranslated region of ELOVL4 causes autosomal dominant Stargardt-like macular dystrophy (STGD3), while homozygous inheritance of three more mutant variants causes severe seizures with ichthyosis, hypertonia, and even death. Some recent studies have described heterozygous inheritance in yet another three mutant ELOVL4 variants, two that cause spinocerebellar ataxia-34 (SCA34) with erythrokeratodermia (EKV) and one that causes SCA34 without EKV. We identified the specific enzymatic reactions catalyzed by ELOVL4 and, using a variety of genetically engineered mouse models, have actively searched for the mechanisms by which ELOVL4 impacts neural function and health. In this review, we critically compare and contrast the various animal model and case studies involving ELOVL4 deficiency via either mutation or deletion, and the resulting consequences on neuronal health and function in both the retina and central nervous system.

Role of reactive oxygen species-total antioxidant capacity status in Telfairia occidentalis leaves-associated spermatoprotective effect: a pointer to fatty acids benefit

Background The present study used reactive oxygen species (ROS)-total antioxidant capacity (TAC) score to understand the role of redox status on the effect of Telfairia occidentalis (TO) on testicular parameters. The fatty acids (FAs) components of methanol extract of TO (METO) and its fractions were also identified with gas chromatography-mass spectrometry. Methods A total of 66 male Wistar rats were randomly divided in a blinded fashion into six oral treatment groups as follows: group I (control, n=6) received 10% ethanol (vehicle for TO administration). Groups II to VI (n=12 rats each) were subdivided into two treatment subgroups (n=6 each) that received 200 mg/kg and 600 mg/kg of METO and its chloroform, petroleum ether, acetone, and ethanol fractions, respectively. All treatments lasted for 30 days. Results The major FAs detected in TO were myristic, palmitic, oleic, linoleic, linolenic, and stearic acids including their esters. Both doses of METO and its fractions increased the semen parameters, TAC and ROS-TAC scores but decreased the ROS when compared with control. Conclusions Using the ROS-TAC score, this study suggests that TO-associated improvement in semen parameters might be partly mediated by a reduction in free radical generation, and that the FAs present in TO might be involved in its spermatoprotective effect.

Increased F2-Isoprostane Levels in Semen and Immunolocalization of the 8-Iso Prostaglandin F2α in Spermatozoa from Infertile Patients with Varicocele

Polyunsaturated fatty acid damages lead to alterations in sperm function. This study aimed to investigate the involvement of F₂-isoprostanes (F₂-IsoPs), oxidized lipid products from arachidonic acid, in sperm quality impairment. For this purpose, F₂-IsoP levels in semen and F₂-IsoP localization in spermatozoa were explored in infertile subjects affected by idiopathic infertility or varicocele, as well as in fertile men. As compared to fertile men, in the idiopathic infertility and varicocele groups, sperm concentration, motility, morphology, viability, and fertility index were significantly lower and the mean scores concerning sperm apoptosis, necrosis, and immaturity were significantly higher. The idiopathic infertile group showed a reduction in sperm motility and fertility index, as well as an increase of apoptosis and necrosis percentages, in comparison to the varicocele group. The varicocele group showed the highest levels of F₂-IsoPs, a significant increase of sperm immaturity, and a significant correlation between F₂-IsoP levels and sperm immaturity. 8-Iso Prostaglandin F_2α, biomarker of in vivo F₂-IsoP, was clearly localized in sperm midpiece and cytoplasmic residues. Data show that F₂-IsoP formation is relevant in semen and sperm from infertile patients with varicocele and high percentage of immaturity, suggesting that a correct fatty acid integrity is needed for sperm maturation.