Sperm DNA Damage Research Articles

Role of intra-individual variation in the detection of thresholds for DFI and for misclassification rates: A retrospective analysis of 14,775 SCSA® tests.

Sperm DNA damage is associated with reduced male fertility after natural conception and intrauterine insemination. However, the impact on in vitro fertilization (IVF) and especially intracytoplasmic sperm injection (ICSI) treatments is still unclear. Few studies have focused on the intra-individual variation in DFI even though it may have an important role to play in terms of detection of thresholds and for misclassification rates. Results for Sperm Chromatin Structure Assay (SCSA®) tests performed for 70 European fertility clinics between January 1st, 2008 and December 31st, 2022 were examined. A small retrospective study included 406 couples receiving their first treatment with IVF or ICSI. These results were then used for a mathematical simulation to investigate the role of intra-individual variation. The large retrospective study included a total of 14,138 diagnostic tests and 637 tests from an IUI study. The distribution of DFI was assessed for the IUI cohort and cohorts of patients attending Sims IVF and Fertility Center Hamburg (FCH). Descriptive analysis of the data was performed regarding time of year, male age, and year. When DFI was above the thresholds of 15 and 25, a significant reduction in ongoing pregnancies after 12weeks of gestation was observed for IVF and ICSI treatments, respectively. For IVF treatments, the pregnancy rate was reduced from 45.1% to 24.6%, odds ratio=2.58 (p=0.004). For ICSI treatments, the pregnancy rate was reduced from 48.6% to 29.6%, odds ratio=2.00 (p=0.032). Intra-individual variation was significantly related to the misclassification rate and the sample size required to identify a threshold. The percentage of patients with a DFI below 15 was 64.8% for the IUI cohort and 51.7% and 41.6% for cohorts of patients attending Sims IVF and FCH, respectively. The median DFI for these cohorts differed significantly and was 11.6, 15.0 and 17.2, respectively. DFI shows a seasonal variation, and increases with male age. During the past 15 years, the median DFI has increased by 0.05% per year (p=0.02). Ongoing pregnancy rates are reduced significantly for both IVF and ICSI treatments when DFI is above the thresholds of 15 and 25, respectively. The misclassification rate and the required sample size increase with increasing intra-individual variation. Couples with a DFI above 15 are more likely to experience failed assisted reproductive technology(ART) cycles. DFI appears to have increased during the past 15 years.

Alterations Expression of Key RNA Methylation (m6A) Enzymes in Testicular Tissue of Rats with Induced Varicocele.

Epigenetics impacts male fertility and reproductive disorders. RNA modifications, like m6A, influence RNA metabolism. Varicocele contributes to male infertility, and oxidative stress affects sperm function. This study investigates the expression of key RNA modification enzymes in a rat varicocele model, aiming to elucidate the relationship between varicocele, oxidative stress, and fertility. Fifteen male Wistar rats were divided into Control, Sham, and Varicocele induction groups. Varicocele was induced in the rats surgically. After 8 weeks, testicular tissues and sperm were collected for analysis, including histopathological assessment and evaluation of sperm parameters, functional tests, and gene expression of key RNA modification enzymes: METTL3 as a writer, ALKBH5 and FTO as erasers, and YTHDF2 as a reader involved in recognizing m6A-modified RNA using qRT-PCR. One-way ANOVAwithpost-hoc Tukey HSDwas used forcomparing tests within groups. Varicocele induction resulted in histological changes in testicular tissues, including irregularly variable-sized seminiferous tubules. Sperm parameters were significantly affected, with lower concentration, motility, and higher percentage of abnormal sperm in the varicocele group. Increased levels of oxidative stress markers (Sperm lipid peroxidation, and intracytoplasmic ROS) and sperm DNA damage were observed, indicating the presence of oxidative stress in varicocele. Moreover, the expression of key enzymes involved in RNA metabolism was downregulated in the varicocele group. These findings highlight the detrimental impact of varicocele on testicular health, sperm quality, and gene expression, providing insights into the underlying mechanisms of male infertility associated with varicocele.

Mitigating effect of chitosan-coated zinc oxide nanoparticles on cryopreservation-induced DNA damage in human spermatozoa

Zinc, an essential micronutrient, is an important mediator of sperm function. Supplementation of zinc oxide nanoparticle (ZnONPs) to semen cryopreservation medium has shown beneficial effects on sperm function, mainly due to its antioxidant and membrane stabilization properties. However, the ZnONPs are known to be membrane impermeable. In the current study, we explored the beneficial properties of membrane permeable zinc oxide nanoparticles on semen cryopreservation outcome. For the study, 52 liquefied human ejaculates were cryopreserved with chitosan-coated ZnONPs and stored in liquid nitrogen for one week. Samples were thawed and assessed for the sperm functional characters and DNA integrity. Significantly higher motility (P < 0.05), prolonged survival (P < 0.05) and lower DNA damage (P < 0.05) was observed in spermatozoa of semen samples cryopreserved with chitosan-coated ZnONPs. In conclusion, the presence of chitosan-coated ZnONPs in the ejaculate prior to cryopreservation increases the survival and decreases DNA damage without compromising with the functional competence of spermatozoa.

Cordycepin improves hyperactivation and acrosome reaction through adenosine receptors during human sperm capacitation in vitro.

Sperm capacitation is a prerequisite for natural or in vitro fertilization. After capacitation, sperm become hyperactivated and undergo an acrosome reaction, which helps them penetrate the oocyte. Cordycepin, a bioactive compound first isolated from Cordyceps militaris, is an adenosine analog with numerous physiological activities. However, its effects on sperm capacitation remain unclear. This study aims to elucidate the effects and mechanisms of cordycepin on human sperm capacitation. During in vitro capacitation culture, healthy human sperm were treated with cordycepin (20, 100, 500 µM). Sperm motility and hyperactivation were detected using a computer-assisted sperm analyzer. Sperm acrosome reaction was measured using fluorescein isothiocyanate-conjugated Pisum sativum agglutinin. Sperm protein kinase A (PKA) activity was analyzed using an ELISA kit. The levels of sperm protein tyrosine phosphorylation were detected by western blotting. Sperm DNA damage was detected by a sperm chromatin dispersion assay. Reactive oxygen species (ROS) were measured using the fluorescence probe 2',7'-dichlorodihydrofluorescein diacetate. The expression and localization of adenosine receptors were analyzed by western blotting and immunofluorescence. The specific inhibitors of adenosine receptors were used to confirm their effects on cordycepin-induced sperm capacitation. Finally, molecular docking was performed to analyze the interaction between cordycepin and adenosine receptors. Cordycepin improved hyperactivated sperm motility, acrosome reaction, PKA activity, and protein tyrosine phosphorylation during capacitation while having no obvious effects on sperm ROS or DNA damage. Four adenosine receptor subtypes were expressed in human sperm, but their localizations differed. Inhibition of adenosine receptors significantly decreased cordycepin-induced sperm hyperactivation and the acrosome reaction. Molecular docking showed that cordycepin can bind to the four subtypes of adenosine receptors. Cordycepin may promote human sperm capacitation through adenosine receptor-mediated signaling pathways. These findings may be useful for assisted reproductive technology and animal breeding.

Towards the Development of Novel, Point-of-Care Assays for Monitoring Different Forms of Antioxidant Activity: The RoXstaTM System

(1) Background: This study set out to develop a series of simple, novel, rapid methods for assessing different forms of antioxidant activity. (2) Methods: An ABTS platform was used to engineer: (i) an electrochemical post-activation assay to assess free radical scavenging activity; (ii) an electrochemical pre-activation strategy to assesses the suppression of free radical formation; (iii) a horseradish peroxidase-mediated oxidation system to monitor hydrogen peroxide scavenging activity and (iv) a cumene peroxide-hematin system to determine the ability of samples to scavenge the mixture of organic peroxides and peroxyl and alkoxyl radicals generated in the presence of these reagents. Each assay was assessed against a panel of candidate antioxidant compounds to determine their relative activities and specificities. In addition, human semen samples were analyzed to determine how the results of these antioxidant assays correlated with semen quality. (3) Results: All 4 assays revealed dose-dependent antioxidant activity on the part of vitamin C, N-acetyl cysteine, hypotaurine, BSA, melatonin, glutathione, resveratrol and epigallocatechin gallate. The other compounds tested either completely lacked antioxidant activity or were only active in one of the assays. Using unfractionated human semen as an exemplar of biological fluids rich in antioxidants, the outputs from the individual assays were found to reflect different aspects of semen quality. When the data from all 4 assays were combined, accurate predictions were generated reflecting the importance of oxidative stress in defining semen quality as reflected by sperm count, seminal lipid aldehyde content, sperm DNA damage and free radical generation by the sperm mitochondria. (4) Conclusions: The methodologies described in this paper constitute the basis for rapid, point-of-care assessments of oxidative stress.

L-Tryptophan improves the sperm quality of threatened Abant trout (Salmo abanticus) against glyphosate toxicity: impact on oxidative stress and DNA damage

The current study focused on the ameliorating impact of TRP (5 mM) on Salmo abanticus spermatozoa exposed to sub‑lethal concentrations of GLY (2.5, 5, and 10 mg/L). Sperm quality parameters, oxidative stress indices, and DNA damage were analyzed in the post‑exposure sperm. Our data reveal that GLY has an adverse effect on motility rate and duration, sperm kinetics parameters, antioxidant status and DNA damage, and triggers antioxidant defense mechanisms at the highest dose (10 mg/L) and it has insufficient therapeutic effect. Overall, GLY poses potential hazards to male reproductive cells and may adversely affect subsequent generations of natural populations.

Evaluation of the Detrimental Impact of Low-Intensity Laser Radiation on the Characteristics of Sperm Movement, Motion, and DNA Damage

It is generally accepted that low-level laser therapy promotes cellular energy production and increases the synthesis of ATP by triggering the mitochondrial electron transport chain's photosensitive cytochrome c oxidase complex. Nevertheless, this investigation aimed to examine the possible adverse impact on sperm function and DNA integrity of low-intensity laser radiation with a wavelength of 980 nm. Following standard analysis, forty semen samples were collected and categorized as either asthenospermic, oligospermic, or normospermic. The remaining semen was subjected to standard semen analysis, and the aliquots were divided into treatment and control groups. A continuous-wave 980 nm laser with an output power of 100 mW and an energy density of 10 J/cm2 was applied to the treated samples for 30 s. Divided samples underwent incubation at 37oC, and semen analysis was used to assess aliquots at 30 s and 2 h intervals. Following the incubation time, each sample was frozen in 250 mL at -80oC until DNA fragmentation was examined using flow cytometry. Thirty minutes after treatment, there was a noticeable increase in sperm movement; the rise was largest in oligospermic and asthenospermic samples (88%) while samples of normal sperm displayed the least increment (7.5%). There was no discernible increase in DNA damage in the treatment samples compared to the control samples. The treatment samples had 21.8% and the control samples had 25.3% of the DNA fragmentation index. The dynamics of sperm motion were noticeably altered. Short-term exposure to low-level laser radiation appeared to improve the motion and movement of treated sperm, and after 2 h, there was no increase in DNA damage. Asthenospermia and mitochondrial dysfunction may be related in some circumstances. To fully understand the ramifications of these results for possible medicinal applications, more research is needed. Our research's conclusions suggest that low-level laser stimulation is a useful and safe technique for identifying viable immotile spermatozoa in a particular sample. It may also cause these spermatozoa to move about, which could have positive therapeutic effects.

Melatonin protects spermatogenic cells against DNA damage and necroptosis induced by atrazine

Atrazine (ATZ), a widely used triazine herbicide, has been shown to disrupt reproductive development in organisms. Melatonin (MLT) is a natural hormone and has been shown to have strong antioxidant properties. Due to its lipophilicity, it can cross biological barriers freely and act on germ cells directly. However, the mechanism through which melatonin affects atrazine-induced damage to male sperm cells remains unclear. This study aimed to investigate the effects of ATZ on spermatocyte development and to elucidate MLT's role in preventing ATZ-induced spermatogenesis failure. Pubertal mice were randomly divided into four groups: blank control group (Con), 5 mg/kg melatonin group (MLT), 170 mg/kg atrazine group (ATZ), and ATZ + MLT group. GC-1 cell culture was employed to access the in vitro effects of MLT and ATZ on spermatogonia. The results indicate that atrazine affected protein and metabolite composition, and reduced sperm viability, sperm motility (VAP, VSL and VCL) and levels of proteins related to spermatogenesis function in the mice testis. Melatonin alleviated the development of cellular DNA damage and necroptosis caused by atrazine both in vivo and in vitro. Moreover, we proposed that it was GC-1 cells developing necroptosis, but not other cell types in the testis. In conclusion, this study suggests that atrazine disrupts the development process, causing DNA damage in spermatozoa during spermatogenesis. Additionally, ATZ-induced necroptosis specifically targets spermatogenic cells. Notably, melatonin alleviates atrazine-induced necroptosis and DNA damage in spermatogenic cells. This study provides new insights into potential therapeutic strategies for atrazine-induced male infertility.

Correlation of IGF2 levels with sperm quality, inflammation, and DNA damage in infertile patients.

Insulin-like growth factor 2 (IGF2) is a critical endocrine mediator implicated in male reproductive physiology. To investigate the correlation between IGF2 protein levels and various aspects of male infertility, specifically focusing on sperm quality, inflammation, and DNA damage, a cohort of 320 male participants was recruited from the Women's Hospital, Zhejiang University School of Medicine (Hangzhou, China) between 1st January 2024 and 1st March 2024. The relationship between IGF2 protein concentrations and sperm parameters was assessed, and Spearman correlation and linear regression analysis were employed to evaluate the independent associations between IGF2 protein levels and risk factors for infertility. Enzyme-linked immunosorbent assay (ELISA) was used to measure IGF2 protein levels in seminal plasma, alongside markers of inflammation (tumor necrosis factor-alpha [TNF-α] and interleukin-1β [IL-1β]). The relationship between seminal plasma IGF2 protein levels and DNA damage marker phosphorylated histone H2AX (γ-H2AX) was also explored. Our findings reveal that IGF2 protein expression decreased notably in patients with asthenospermia and teratospermia. Correlation analysis revealed nuanced associations between IGF2 protein levels and specific sperm parameters, and low IGF2 protein concentrations correlated with increased inflammation and DNA damage in sperm. The observed correlations between IGF2 protein levels and specific sperm parameters, along with its connection to inflammation and DNA damage, underscore the importance of IGF2 in the broader context of male reproductive health. These findings lay the groundwork for future research and potential therapeutic interventions targeting IGF2-related pathways to enhance male fertility.

The effect of myo-inositol antioxidant activity on human sperm parameters and DNA damage in ultra-rapid and conventional freezing methods

Male fertility preservation is still challenged by cell damage induced during sperm cryopreservation and impaired sperm structure and function. Sperm ultra-rapid freezing, despite a higher protective effect compared to conventional freezing method, is still associated with suboptimal sperm cryosurvival and needs to be modified to increase its efficiency in sperm protection. Sperm freezing media supplemented with antioxidants can improve sperm parameters following freezing-warming process. In this study, we aimed to investigate the effect of employing ultra-rapid freezing and myo-inositol on sperm cryosurvival. Thirty semen samples with normal sperm parameters were collected and each one was divided into four portions to cryopreserve by conventional freezing, ultra-rapid freezing, conventional freezing + myo-inositol 2 mg/ml, and ultra-rapid freezing + myo-inositol 2 mg/ml. Sperm samples warmed after at least 24 h of freezing and sperm cryosurvival were analyzed by evaluation of sperm motility, viability, morphology and DNA fragmentation index (DFI). Freezing method had a significant influence on post-thaw sperm DFI and morphology (p < 0.05) and the interaction between freezing method and antioxidant supplementation significantly affected sperm morphology (p < 0.05). The highest percentage of sperm normal morphology and minimal DFI was achieved using ultra-rapid freezing supplemented by myo-inositol antioxidant compared to other groups (P < 0.05). The highest sperm DNA damage after freezing-warming was observed following the conventional freezing method. In conclusion, sperm freezing method was identified as factor strongly influencing sperm DFI and morphology after thawing/warming. Sperm samples can be rapidly frozen using the modified freezing media supplemented by myo-inositol without impacting sperm DNA and morphology.

Nme8 is essential for protection against chemotherapy drug cisplatin-induced male reproductive toxicity in mice.

Cisplatin (CP), a chemotherapy drug commonly used in cancers treatment, causes serious reproductive toxicity. With younger cancer patients and increasing survival rates, it is important to preserve their reproductive capacity. NME8 is highly expressed in testis and contains thioredoxin and NDPK domains, suggesting it may be a target against the CP-induced reproductive toxicity. We deleted exons 6-7 of the Nme8 in mice based on human mutation sites and observed impaired transcript splicing. In mice, Nme8 was not essential for spermatogenesis, possibly due to functional compensation by its paralog, Nme5. Nme8 expression was elevated and translocated to the nucleus in response to two weeks of CP treatment. Under CP treatment, Nme8 deficiency further impaired antioxidant capacity, induced lipid peroxidation and increased ROS level, and failed to activate autophagy, resulting in aggravated DNA damage in testes and sperm. Consequently, the proliferation and differentiation of spermatogonia and the meiosis of spermatocyte were almost completely halted, and sperm motility was impaired. Our research indicates that NME8 protects against CP-induced testis and sperm damage. This may provide new insights into the physiological functions of the Nme family and potential targets for preserving fertility in young male cancer patients.

Perspective in the Mechanisms for Repairing Sperm DNA Damage.

DNA damage in spermatozoa is a major cause of male infertility. It is also associated with adverse reproductive outcomes (including reduced fertilization rates, embryo quality and pregnancy rates, and higher rates of spontaneous miscarriage). The damage to sperm DNA occurs during the production and maturation of spermatozoa, as well as during their transit through the male reproductive tract. DNA damage repair typically occurs during spermatogenesis, oocytes after fertilization, and early embryonic development stages. The known mechanisms of sperm DNA repair mainly include nucleotide excision repair (NER), base excision repair (BER), mismatch repair (MMR), and double-strand break repair (DSBR). The most severe type of sperm DNA damage is double-strand break, and it will be repaired by DSBR, including homologous recombination (HR), classical non-homologous end joining (cNHEJ), alternative end joining (aEJ), and single-strand annealing (SSA). However, the precise mechanisms of DNA repair in spermatozoa remain incompletely understood. DNA repair-associated proteins are of great value in the repair of sperm DNA. Several repair-related proteins have been identified as playing critical roles in condensing chromatin, regulating transcription, repairing DNA damage, and regulating the cell cycle. It is noteworthy that XRCC4-like factor (XLF) and paralog of XRCC4 and XLF (PAXX) -mediated dimerization promote the processing of populated ends for cNHEJ repair, which suggests that XLF and PAXX have potential value in the mechanism of sperm DNA repair. This review summarizes the classic and potential repair mechanisms of sperm DNA damage, aiming to provide a perspective for further research on DNA damage repair mechanisms.

Effects of Butylated Hydroxytoluene and Sorbitol as Diluent Components on Structural and Surface Ultrastructural Changes of Gaga Chicken Sperm During Cryopreservation

The Gaga chicken is an indigenous Indonesian breed that is important to preserve using semen cryopreservation technology. The study was conducted to determine the effect of adding sorbitol and butylated hydroxytoluene (BHT) in the diluent on the structural and surface ultrastructure of cryopreserved Gaga chicken sperm during cryopreservation /frozen storage. The study aimed to assess how adding sorbitol and butylated hydroxytoluene (BHT) to the diluent affects the structure and surface ultrastructure of cryopreserved Gaga chicken sperm. A completely randomized design was employed with four treatments and 10 replications including egg yolk-lactate ringer diluent (EYLR) as the control group, EYLR diluent with 3 mM BHT, EYLR diluent with 2% sorbitol, and EYLR diluent with both 3 mM BHT and 2% sorbitol. Semen was collected using a massage technique from 4 male chickens aged approximately 10 months, pooled semen was diluted, packaged in 0.25 mL straws, equilibrated for 2 hours at 5 °C, pre-freeze for 10 minutes, frozen for 24 hours, and thawed for 30 seconds at 37 °C. The parameters evaluated were sperm plasma membrane integrity, acrosome integrity, DNA damage, mitochondrial functionality, and surface ultrastructure. The results showed that the treatment had a significant effect on plasma membrane integrity and post-thawing mitochondrial functionality compared to the control, but no effect was observed on acrosome integrity or DNA damage. The results showed that the combination treatment of BHT with sorbitol had a significant effect on plasma membrane integrity and post-thawing mitochondrial function, but did not affect acrosome integrity or DNA damage when compared to the control group. Ultrastructural observations indicated that cryopreservation caused damage to the head, middle, and tail of the sperm in the control groups. However, these changes were prevented by the diluent containing a combination of BHT and sorbitol. The addition of both components (BHT 3 mM + sorbitol 2%) effectively maintained plasma membrane integrity, mitochondrial functionality, and surface ultrastructure of Gaga chicken sperm during cryopreservation. Keywords: Butylated hydroxytoluene, Chicken sperm, Cryopreservation, Sorbito, Structure, Sperm ultrastructure

Integrated cytological and transcriptomic analyses provide new insights into restoration of pollen viability in synthetic allotetraploid Brassica carinata.

Upregulation of genes involved in DNA damage repair and sperm cell differentiation leads to restoration of pollen viability in synthetic allotetraploid B. carinata after chromosome doubling. Apart from the well-known contribution of polyploidy to crop improvement, polyploids can also be induced for other purposes, such as to restore the viability of sterile hybrids. The mechanism related to viability transition between the sterile allodiploid and the fertile allotetraploid after chromosome doubling are not well understood. Here, we synthesised allodiploid B. carinata (2n = 2x = 17) and allotetraploid B. carinata (2n = 4x = 34) as models to investigate the cytological and transcriptomic differences during pollen development. The results showed that after chromosome doubling, the recovery of pollen viability in allotetraploid was mainly reflected in the stabilisation of microtubule spindle morphology, normal meiotic chromosome behaviour, and normal microspore development. Interestingly, the deposition and degradation of synthetic anther tapetum were not affected by polyploidy. Transcription analysis showed that the expression of genes related to DNA repair (DMC1, RAD51, RAD17, SPO11-2), cell cycle differentiation (CYCA1;2, CYCA2;3) and ubiquitination proteasome pathway (UBC4, PIRH2, CDC53) were positively up-regulated during pollen development of synthetic allotetraploid B. carinata. In summary, these results provide some refreshing updates about the ploidy-related restoration of pollen viability in newly synthesised allotetraploid B. carinata.

Standardization and application of ARMS TaqMan real-time PCR for screening of folate metabolism genes in Han Chinese.

Folate has antioxidant properties, and low concentration in seminal plasma may be associated with increased DNA damage in sperm. Mutations of the methylenetetrahydrofolate reductase (MTHFR) and methionine synthase reductase (MTRR) genes, including MTHFR C677T (rs1801133), MTHFR A1298C (rs1801131), and MTRR A66G (rs1801394), can lead to decreased activity of the encoded folate metabolic enzymes, thereby affecting male reproduction. The current SNP detection methods commonly used in clinical practice have some shortcomings, such as long time-consuming, complex detection steps, or high cost. The purpose of this study was to establish a simple, time-saving, sensitive, accurate, and easy to clinical popularization method for folate metabolism gene detection. We combined ARMS-PCR with TaqMan fluorescent probe to establish an ARMS TaqMan real-time PCR detection method. According to the variation of rs1801131, rs1801133, and rs1801394, two specific primers (one wild type and one mutant) were designed. Mismatched nucleotides were introduced at the penultimate or third position to improve the specificity of the primer. Specific TaqMan probe was introduced to detect PCR products to improve the sensitivity of the method. The results showed that the sensitivity of ARMS TaqMan real-time PCR in SNP genotyping was 1ng, and the accuracy was 100%. A total of 249 clinical samples were detected by the established method, and the correlation between three SNPs and semen quality was analyzed. We found that individuals carrying the AG+GG genotype of rs1801394 had a lower risk of abnormal semen quality. In conclusion, we developed a highly sensitive, accurate, rapid, and easy to be popularized method for detecting SNPs of rs1801394, rs1801131, and rs1801133. ARMS TaqMan real-time PCR is a reliable SNP genotyping method in folate metabolism genes.

The storage time of cryopreserved human spermatozoa does not affect pathways involved in fertility

BackgroundCryopreservation of human spermatozoa is a widely used technique in the assisted reproduction technology laboratory for the storage of gametes for later use, for the fertility preservation and for sperm donation programs. Cryopreservation can cause damage to membrane, cytoskeletal, acrosome and increased oxidative stress, sperm DNA damage and transcriptome changes. To assess the impact of storage time on the transcriptome of frozen human spermatozoa, semen samples were collected from 24 normospermic donors of whom 13 had cryostored semen for a short-time (1 week) and 11 had cryostored semen for a long-time (median 9 years).ResultsRNA was extracted from each frozen-thawed sperm sample, randomized in pools, and analyzed by microarrays. Five transcripts were in higher abundance in the long-time respect to the short-time storage group. Functional annotation enrichment disclosed that that the length of cryostorage has no effect on critical pathways involved in sperm physiology and function.ConclusionsThe storage time of cryopreserved human spermatozoa does not affect pathways involved in fertility.

Addition of Cryoprotectant DMSO Reduces Damage to Spermatozoa of Yellow Catfish (Pelteobagrus fulvidraco) during Cryopreservation: Ultrastructural Damage, Oxidative Damage and DNA Damage.

Spermatozoa cryopreservation protocols have been established for yellow catfish (Pelteobagrus fulvidraco), but cryopreservation can still cause cellular damage and affect spermatozoa viability and fertility. Therefore, the aim of this paper was to evaluate the effects of adding or not adding cryoprotectants during low-temperature storage on the ultrastructural damage, oxidative damage, and DNA damage of thawed yellow catfish spermatozoa. The mixed semen of three male yellow catfish was divided into a fresh spermatozoa group, a frozen spermatozoa group (DMSO+) with a cryoprotectant (10% DMSO), and a frozen spermatozoa group without a cryoprotectant (DMSO-). Ultrastructural of the spermatozoa after thawing were observed under an electron microscope and the spermatozoa were assayed for SOD, MDA, and T-AOC enzyme activities, as well as for DNA integrity. In terms of movement parameters, compared with DMSO-, the addition of DMSO has significantly improved sperm motility, curve line velocity (VCL), and straight line velocity (VSL). The ultrastructural results showed that although thawed spermatozoa exhibited increased damage than fresh spermatozoa, 10% DMSO effectively reduced the damage to the plasma membrane, mitochondria, and flagellum of spermatozoa by cryopreservation, and most of the spermatozoa were preserved with intact structure. The results of oxidative damage showed that compared with frozen spermatozoa, 10% DMSO significantly increased the activities of SOD and T-AOC enzymes and clearly reduced the activity of the MDA enzyme. The antioxidant capacity of spermatozoa was improved, lipid peroxidation was reduced, and the oxidative damage caused by cryopreservation was mitigated. The DNA integrity of spermatozoa showed that 10% DMSO clearly reduced the DNA fragmentation rate. In conclusion, 10% DMSO can effectively reduce the ultrastructural damage, oxidative damage, and DNA damage of yellow catfish spermatozoa during cryopreservation; it can also further optimize the cryopreservation protocol for yellow catfish spermatozoa. Meanwhile, it also provides a theoretical basis for the future optimization of the cryopreservation protocols.

Spermiogram, Kinetics, Flow Cytometric Characteristics and DNA Damage Degree in Boar Ejaculates: Summarization and Clustering.

Boar semen analysis includes sperm motility, concentration, morphology and other more complex analyses such as membrane integrity, DNA damage and seminal plasma components. This study aims to summarize these numerous data by linear combinations of them, to classify ejaculates in several categories (clusters) and to investigate the potential differences among clusters on fertility and prolificacy. Young Pietrain boars (23 ± 3.6 months) were investigated: ten boars from the Nucléus genetic line (group 1: 90 ejaculates weekly) and five boars from the Batallé genetic line (group 2: 30 ejaculates weekly). Computer-assisted semen analysis (CASA) examined motility. Sperm viability, acrosome reaction, early apoptosis, mitochondrial activity and DNA damage were studied by flow cytometry analysis. SPSS v.26 software was used to perform principal component analysis (PCA) and clustering. Three principal components (PC1: speed; PC2: linear path; PC3: DNA damage) were detected and four clusters identified in both groups. Clusters also differed significantly in several variables not included in these PCs (group 1: beat cross frequency and poly (ADP-ribose) polymerase; group 2: cathepsin B, abnormal forms, mitochondrial activity and high DNA stainability). PCA and clustering achieved adequate description of these ejaculates, but no differences among clusters were found for fertility or prolificacy, probably because the minimum sperm requirements had been met.

A Study of Sperm DNA Damage Mechanism Based on miRNA Sequencing.

To analyze the differential expression profiles of microRNAs (miRNAs) in spermatozoa of patients with sperm DNA damage and to investigate the role of miRNAs in sperm DNA damage. Male infertility patients with sperm DNA damage who attended the First Affiliated Hospital of Henan University of Chinese Medicine from October 2023 to December 2023 were selected and included in this study as a case group. Fertile healthy men who were seen at the health check-up center during the same period and diagnosed by examination were also included as a control group. Sperm miRNA expression was detected in patients with sperm DNA damage (case group, n = 5) and healthy medical check-ups (control group, n = 5) using high-throughput sequencing technology. The differentially expressed miRNAs between the two groups were bioinformatically analyzed to explore the main biological functions of the target genes. We found that 63 miRNAs were significantly changed in the spermatozoa of patients with sperm DNA damage,|log2 (foldchange)| ≥ 1, p < .05. Gene Ontology (GO) enrichment analysis indicated that these differential miRNAs might be involved in developmental process, anatomical structure development, cellular macromolecule metabolic process, multicellular organism development, system development, and so on. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis showed that that they mainly affect the PI3K-AKT signaling pathway. The present study suggests that the altered expression of miR-1255a, miR-921, and miR-3156-5p may play an important role in the sperm DNA damage process, and the mechanism may involve the phosphatidylinositol-3'-kinase-AKT (PI3K-AKT) signaling pathway.

The Role of Selected Elements in Oxidative Stress Protection: Key to Healthy Fertility and Reproduction.

Oxidative stress and its relationship to fertility and reproduction is a topic of interest in medicine, especially in the context of the effects of trace elements and micronutrients. Oxidative stress occurs when there is an excess of free radicals in the body, which can lead to cell and tissue damage. Free radicals are reactive oxygen species (ROS) that can be formed as a result of normal metabolic processes, as well as under the influence of external factors such as environmental pollution, UV radiation, and diet. Oxidative stress has a significant impact on fertility. In men, it can lead to DNA damage in sperm, which can result in reduced semen quality, reduced sperm motility and increased numbers of defective sperm, and free radical damage to sperm cell membranes causing a reduction in the number of available sperm. In women, oxidative stress can affect the quality of female reproductive cells, which can lead to problems with their maturation and with embryo implantation in the uterus and can also affect ovarian function and disrupt hormonal regulation of the menstrual cycle. A proper balance of trace elements and micronutrients is key to protecting against oxidative stress and maintaining reproductive health. Supplementation with appropriate elements such as zinc, selenium, copper, manganese, chromium, and iron can help reduce oxidative stress and improve fertility. This work discusses the effects of selected elements on oxidative stress parameters specifically in terms of fertility and reproduction.