Oxidative stress and male infertility

The combined effect between environmental exposure and oxidative stress-related susceptible gene polymorphisms on human semen quality

PURPOSE

The aim of the current study was to investigate the relationship between environmental factors and metabolic gene genotypes related to semen quality.

METHODS

A total of 341 men were recruited and classified into normal or abnormal semen quality groups according to the World Health Organization's 2010 criteria. Alcohol and tobacco use among men was self-reported. Pb (lead), As (arsenic), Ti (titanium), and Zn (zinc) metal elements in seminal plasma were measured using inductively coupled plasma mass spectrometry (ICP-MS). The ALDH2 rs671 and GSTP1 rs1695 polymorphism were detected using high-resolution melting (HRM) PCR.

RESULTS

Individual environmental factors, including smoking, drinking, and exposure to Pb, As, Ti, or Zn, did not significantly associate with the risk of semen abnormalities. The ALDH2 GA/AA mutation genotype increased the risk of semen abnormalities in smoking males (AOR = 1.27; 95% CI, 1.01-1.62) and in males with high seminal Ti levels (AOR = 1.36; 95% CI, 1.00-1.90). The GSTP1 rs1695 gene (GG/AG) mutation genotype exhibited a protective effect on semen quality in males who did not consume alcohol (AOR = 0.65; 95% CI, 0.51-0.85) or smoke (AOR = 0.79; 95% CI, 0.61-1.00), as well as in those with low Pb (AOR = 0.63; 95% CI, 0.46-0.88) and Ti (AOR = 0.64; 95% CI, 0.47-0.90) exposure.

CONCLUSIONS

The current study demonstrated that genetic and environmental factors interact with semen quality, and that men with the ALDH2 rs671A or GSTP1 rs1695A allele are susceptible to Ti-, alcohol-, and tobacco-induced semen quality abnormalities.

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

ABSTRACT

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 1 st January 2024 and 1 st 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.

Chronic psychological stress induces testicular oxidative stress affecting reproductive behavior in rats

The inhibitory effect of chronic psychological stress on reproductive behavior is widely recognized since long. However, the biological mechanisms underlying these effects, especially the cellular biology of the testicular cells, have not been fully investigated. This study aimed to investigate the effects of chronic psychological stress on rat reproductive behavior and its correlation with testicular cell damage and oxidative stress. The results showed that chronic psychological stress led to a decline in the preference scores of male rats for female rats and caused damage to the testicular tissue structure. Subcellular structures were particularly affected in the chronic psychological stress rats. Furthermore, the levels of MDA, NO, and NOS in testicular cells substantially increased under chronic psychological stress conditions. In conclusion, male reproductive behavioral disorders induced by chronic psychological stress are potentially linked to oxidative damage in testicular tissue.

Association between the composite dietary antioxidant index and risk of infertility: Evidence from NHANES 2013-2020 and a Mendelian randomization study

OBJECTIVE

The Composite Dietary Antioxidant Index (CDAI) measures the antioxidant capacity of the diet, which is believed to provide protection against various diseases, including depression, osteoporosis, and papillomavirus infection, by neutralizing harmful oxidative stress. However, the relationship between CDAI and infertility is not well understood. This research aims to explore the potential correlations between CDAI and the risk of infertility.

METHODS

This research harnessed data from the National Health and Nutrition Examination Survey (NHANES) to execute a cross-sectional analysis involving 8263 US women aged 20-45. Each participant was subjected to two distinct 24-h dietary recall interviews. We calculated the CDAI using average daily antioxidant intake. Infertility was assessed using a standardized questionnaire. The association between CDAI and infertility was examined using weighted multiple logistic regression models, while nonlinear correlations were explored through restricted cubic splines. To affirm the robustness of our findings, sensitivity and subgroup analyses were performed using unweighted logistic regression. Additionally, to ascertain the causal influence of circulating antioxidant levels on infertility, a two-sample univariable Mendelian randomization (MR) analysis was conducted, using the inverse variance weighted (IVW) method as the primary analytic approach.

RESULTS

Participants who were infertile exhibited lower CDAI levels compared to their fertile counterparts. When confounding variables were accounted for in the multivariate weighted logistic regression model, an inverse relationship was observed between CDAI and infertility, with the odds ratio for the highest versus lowest quartile being 0.55 (0.33-0.90, P = 0.02). However, the IVW method indicated that genetically predicted elevated levels of CDAI did not significantly correlate with infertility.

CONCLUSION

Cross-sectional observational studies indicate that antioxidants from diets might diminish infertility risks. However, findings from MR studies do not confirm a causal connection. Additional prospective research is required to elucidate this association further.

WTAP-mediated m6A modification of Hmgb2 contributes to spermatogenic damage induced by PM2.5 exposure

N6-methyladenosine (m6A) is extensively involved in complex spermatogenesis while being extremely sensitive to environmental exposure. Numerous studies have revealed the toxicity of fine particulate matter (PM2.5) to the male reproductive system, but the specific epigenetic mechanisms involved have been underexplored. Here, we investigated the effect of m6A modification on PM2.5-induced male reproductive impairment by establishing a real-time PM2.5-exposed mouse model and a GC-2spd cell model. PM2.5 exposure resulted in damage to the spermatogenic epithelium and mitochondrial abnormalities in spermatocytes and significantly reduced sperm motility in mice. Gene enrichment analyses of testicular tissue differential m6A modified genes were significantly enriched to spermatogenesis in the PM2.5-treated mice compared with the control group, and the expression of the methylase WTAP was markedly decreased after PM2.5 exposure. Moreover, PM2.5 exposure resulted in a significant reduction in the expression of the spermatogenesis-related gene Hmgb2, as well as in the level of the Hmgb2 m6A modification. Transcriptome sequencing and verification experiments suggested that Hmgb2 may regulate spermatocyte ATP levels. In addition, we demonstrated that the m6A methylase WTAP affects Hmgb2 mRNA stability via m6A modification. Our study provides new insights into PM2.5-induced damage to spermatogenesis and reduced sperm motility.

Ferroptosis emerges as the predominant form of regulated cell death in goat sperm cryopreservation

BACKGROUND

Freezing-induced sperm damage, often associated with oxidative stress, can result in regulated cell death. Given that oxidative stress can trigger various forms of regulated cell death, the prevailing form during sperm cryopreservation remains unknown. Our study aimed to investigate this issue using cashmere goats as a model.

RESULTS

We found a significant increase in lyso-phospholipids in frozen-thawed sperm suggested ferroptosis. Assessment of cryopreserved sperm, with or without prior treatment with ferroptosis or apoptosis inhibitors, demonstrated the significant efficacy of ferroptosis inhibitors in reducing freezing damage. This implicates ferroptosis as the primary form of regulated cell death induced during sperm cryopreservation. Additionally, the positive rate of transferrin receptor protein 1 was significantly lower in fresh live sperm (47.8%) than in thawed live sperm (71.5%), and the latter rate was lower than that in dead sperm (82.5%). By contrast, cleaved caspase-3 positivity showed no significant difference between fresh live sperm and thawed live sperm but was notably lower in thawed live sperm than in dead sperm.

CONCLUSIONS

Our findings establish ferroptosis as the dominant regulated cell death form during goat sperm cryopreservation, providing novel insights into freezing-induced sperm damage mechanisms. These findings have significant implications for optimizing cryopreservation protocols and enhancing sperm viability after freezing-thawing.

A review of antioxidant strategies to improve reproduction in aging male broiler breeders

As only 10% of the broiler breeder flock is roosters, their fertility is very important. The rooster sperm plasma membrane has high concentrations of polyunsaturated fatty acids that are sensitive to oxidative stress. Lipid peroxidation can change membrane structure, permeability, and fluidity, adversely affecting the acrosome reaction and fertility. Aging roosters have decreases in sexual behavior, serum androgen concentrations, sperm quantity and quality, and fertility. Low fertility in aging roosters is attributed to an imbalanced testicular oxidant-antioxidant system, with increased reactive oxygen species (ROS) damaging spermatogenic epithelium. However, antioxidant components can enhance antioxidant defenses in aging broiler breeder roosters. Protection against oxidative damage, particularly in the testes, improves reproductive hormone concentrations, testicular histology, sperm membrane function, and mitochondrial activity and thereby improves semen volume, sperm concentration, viability, motility, and sperm polyunsaturated fatty acid content, sperm-egg penetration, fertility, and reproductive performance. This review summarizes antioxidants that could improve fertility and reproductive performance and delay or prevent age-related declines in broiler breeder roosters, with benefits for poultry production.

Physical activity and male reproductive function

Fecundity is declining in humans, which is partly due to male infertility. Poor sperm parameters, the main contributors to male infertility, are associated with sedentary, unhealthy lifestyle and poor dietary habits. Long periods of sedentary work lead to visceral adiposity and persistently elevated scrotal temperatures, which adversely affect spermatogenesis. Apart from increasing scrotal temperatures, excessive visceral adiposity exacerbates adipocyte dysfunction with increased pro-inflammatory adipokine release, like leptin. These, together with the increased scrotal temperature, are responsible for the poor sperm quality. The importance of regular physical activity in male fertility remains a matter of debate, as not all forms of exercises have been found to benefit sperm function. Sperm parameters are, nevertheless, somewhat better in active than in sedentary men. It now appears that low-to-moderate intensity exercises are more beneficial for male reproductive health than high-intensity exercises, which have a negative effect on spermatozoa. Low-to-moderate intensity exercises, in general, improve the overall organ-system function in the body, improve the management of body weight and oxidative stress, consequently improving sperm parameters. The detrimental effects of high-intensity exercises on spermatozoa result from disruption in the hypothalamus-pituitary-gonadal-axis, raised testicular temperature and increased oxidative stress. It, therefore, seems that not all types of exercises are beneficial for male reproductive health. Although some low-to-moderate intensity exercises improve male reproductive function, there remains a need to identify the best form of low-to-moderate intensity exercises, particularly those that do not increase testicular temperature or oxidative stress, to help maintain normal body weight and male reproductive health.

ASB1 engages with ELOB to facilitate SQOR ubiquitination and H2S homeostasis during spermiogenesis

Male infertility, frequently driven by oxidative stress, impacts half of infertile couples globally. Despite its significance, the precise mechanisms governing this process remain elusive. In this study, we demonstrate that ASB1, the substrate recognition subunit of a ubiquitin ligase, is highly expressed in the mouse testis. Mice lacking the Asb1 gene exhibit severe fertility impairment, characterized by oligoasthenoteratozoospermia. Subsequent investigations unveiled that Asb1 knockout (Asb1-KO) mice encountered excessive oxidative stress and decreased hydrogen sulfide (H2S) levels in their testes, and severe sperm DNA damage. Notably, the compromised fertility and sperm quality in Asb1-KO mice was significantly ameliorated by administering NaHS, a H2S donor. Mechanistically, ASB1 interacts with ELOB to induce the instability of sulfide-quinone oxidoreductase (SQOR) by enhancing its K48-linked ubiquitination on residues K207 and K344, consequently triggering proteasomal degradation. This process is crucial for preserving H2S homeostasis and redox balance. Overall, our findings offer valuable insights into the role of ASB1 during spermiogenesis and propose H2S supplementation as a promising therapeutic approach for oxidative stress-related male infertility.

Heat-not-burn technology affects plasma testosterone levels and markers of inflammation, oxidative stress in the testes of rats

Introduction

Heating tobacco products (HTPs) are advanced electronic cigarette models. Classified by the FDA as a modified-risk tobacco product and can be used as part of efforts to quit smoking. Using heat-not-burn (HnB) technology, these devices heat tobacco avoiding complete combustion. Although the levels of toxicants in the mainstream are significantly lower than those observed in tobacco smoke, some recent studies have raised concerns about potential health risks associated with their use, particularly regarding their effects on male gonadal function, which remain largely unexplored.

Methods

Adult male Sprague-Dawley rats were exposed, whole body, 5 days/week for 4 weeks to HnB mainstream.

Results

The expression of the cell cycle regulators Bax/Bcl-2 ratio is not affected, along with no changes in p-38. On the other hand, an increase in oxidative stress markers, including those associated with DNA damage, was observed in exposed animals, along with the induction of NF-kB dependent pro-inflammatory mediators: TNF-α, IL-1β, IL-6 and COX-2. Furthermore, inactivation of key androgenic enzymes, such as 3β-hydroxysteroid dehydrogenase and 17β-hydroxysteroid dehydrogenase, together with decreased testosterone synthesis suggest a potential impairment of male gonadal function.

Discussion

The results indicate that animals exposed to HnB smoke show higher levels of oxidative stress markers, including those associated with DNA damage, as well as higher levels of pro-inflammatory cytokines. The impairment of some androgenic key enzymes and those related to the activity of seminiferous epithelium, together with the decrease in testosterone levels, suggest an impairment of gonadal function through the alteration of some cellular pathways typically associated with tobacco consumption.

Oxidative-Stress-Mediated Epigenetic Dysregulation in Spermatogenesis: Implications for Male Infertility and Offspring Health

Male reproductive health is governed by an intricate interplay of genetic, epigenetic, and environmental factors. Epigenetic mechanisms-encompassing DNA methylation, histone modifications, and non-coding RNA activity-are crucial both for spermatogenesis and sperm maturation. However, oxidative stress, driven by excessive reactive oxygen species, disrupts these processes, leading to impaired sperm function and male infertility. This disruption extends to epigenetic modifications, resulting in abnormal gene expression and chromatin remodeling that compromise genomic integrity and fertilization potential. Importantly, oxidative-stress-induced epigenetic alterations can be inherited, affecting the health and fertility of offspring and future generations. This review investigates how oxidative stress influences epigenetic regulation in male reproduction by modifying DNA methylation, histone modifications, and non-coding RNAs, ultimately compromising spermatogenesis. Additionally, it discusses the transgenerational implications of these epigenetic disruptions and their potential role in hereditary infertility and disease predisposition. Understanding these mechanisms is vital for developing therapeutic strategies that mitigate oxidative damage and restore epigenetic homeostasis in the male germline. By integrating insights from molecular, clinical, and transgenerational research, this work emphasizes the need for targeted interventions to enhance male reproductive health and prevent adverse outcomes in progeny. Furthermore, elucidating the dose-response relationships between oxidative stress and epigenetic changes remains a critical research priority, informing personalized diagnostics and therapeutic interventions. In this context, future studies should adopt standardized markers of oxidative damage, robust clinical trials, and multi-omic approaches to capture the complexity of epigenetic regulation in spermatogenesis. Such rigorous investigations will ultimately reduce the risk of transgenerational disorders and optimize reproductive health outcomes.

Polydatin, a derivative of resveratrol, ameliorates busulfan-induced oligozoospermia in mice by inhibiting NF-κB pathway activation and suppressing ferroptosis

Polydatin (PD), a glucoside derivative of resveratrol (RES), is extracted as a monomer compound from the dried rhizome of Polygonum cuspidatum. Our laboratory synthesized PD via the biotransformation of resveratrol. To assess the reproductive protective effects of PD, an oligozoospermia mouse model was induced by administering 30 mg/kg busulfan (BUS) via intraperitoneal injection. Initially, mice were categorized into groups based on PD concentrations of 10, 50, and 100 mg/kg. Subsequently, the optimal concentration of 10 mg/kg was ascertained based on testis weight and spermatological parameters. Additionally, a 10 mg/kg resveratrol group was included as a control. The findings revealed that exposure to BUS resulted in a reduction of testicular weight, diminished spermatogenic cells and epididymal sperm counts, increased sperm deformity, disordered testicular cytoskeleton, compromised blood-testis barrier integrity, and a significant decrease in serum sex hormone levels, notably testosterone. This resulted in decreased expression of androgen receptors and other testosterone-related proteins, increased levels of malondialdehyde and reactive oxygen species, and promoted testicular ferroptosis. However, PD could successfully reverse these injuries. High-throughput sequencing data demonstrated that polydatin significantly downregulated the expression of inflammatory and metabolic genes, including PRKCQ and CARD11. These proteins are pivotal in the activation of the NF-κB pathway during the inflammatory response. Molecular docking studies showed that PD could interact with PRKCQ and CARD11 to reduce the level of inflammation. Additionally, PD was shown to interact with the ferroptosis-promoting gene ACSL4, modulating ferroptosis. In summary, PD facilitates the reversal of BUS-induced oligozoospermia through the mitigation of oxidative stress and inflammation, the inhibition of ferroptosis, and the modulation of hormonal levels.

Efficacy of Chlorogenic Acid in Treating Tripterygium Glycoside-Induced Asthenozoospermia in Rats and Its Possible Mechanisms

Tripterygium glycosides (TGs) are the most common form of traditional Chinese medicine, known as Tripterygium wilfordii Hook F (TWHF) [...].

ALDH2 plays a role in spermatogenesis and male fertility by regulating oxidative stress in mice

Spermatogenesis and sperm maturation are complex biological processes that involve intricate cellular and molecular interactions. The Aldh2 gene is involved in the metabolism of specific aldehydes generated by oxidative stress. Aldh2 is abundantly expressed in the testis and epididymis; however, the specific role of Aldh2 in regulating spermatogenesis and sperm maturation remains unclear. In the present study, we generated Aldh2 knockout (Aldh2-/-) mice by using CRISPR/Cas9 technology. Aldh2 gene knockout decreased the fertility of male mice. Compared to the control group mice, Aldh2-/- mice showed a significant decrease in the thickness of the seminiferous tubules and the number of germ cells. Further investigation revealed that the meiosis of spermatocytes and acrosome formation in sperm were disrupted in Aldh2-/- mice, leading to oligoasthenoteratozoospermia in male mice. However, the caput epididymis and cauda epididymis in Aldh2-/- mice showed identical proportions of morphologically abnormal sperm. Mechanistically, 4-hydroxynonenal, 3-nitro-L-tyrosine, and malondialdehyde levels were significantly elevated in both the testis and epididymis of Aldh2-/- mice, thus indicating increased oxidative stress in the reproductive system. Collectively, our findings demonstrate that Aldh2 plays a critical role in spermatogenesis by regulating oxidative stress in mice.

Micronucleus counts correlating with male infertility: a clinical analysis of chromosomal abnormalities and reproductive parameters

ABSTRACT

Investigating the correlation between micronucleus formation and male infertility has the potential to improve clinical diagnosis and deepen our understanding of pathological progression. Our study enrolled 2252 male patients whose semen was analyzed from March 2023 to July 2023. Their clinical data, including semen parameters and age, were also collected. Genetic analysis was used to determine whether the sex chromosome involved in male infertility was abnormal (including the increase, deletion, and translocation of the X and Y chromosomes), and subsequent semen analysis was conducted for clinical grouping purposes. The participants were categorized into five groups: normozoospermia, asthenozoospermia, oligozoospermia, oligoasthenozoospermia, and azoospermia. Patients were randomly selected for further study; 41 patients with normozoospermia were included in the control group and 117 patients with non-normozoospermia were included in the study group according to the proportions of all enrolled patients. Cytokinesis-block micronucleus (CBMN) screening was conducted through peripheral blood. Statistical analysis was used to determine the differences in micronuclei (MNi) among the groups and the relationships between MNi and clinical data. There was a significant increase in MNi in infertile men, including those with azoospermia, compared with normozoospermic patients, but there was no significant difference between the genetic and nongenetic groups in azoospermic men. The presence of MNi was associated with sperm concentration, progressive sperm motility, immotile spermatozoa, malformed spermatozoa, total sperm count, and total sperm motility. This study underscores the potential utility of MNi as a diagnostic tool and highlights the need for further research to elucidate the underlying mechanisms of male infertility.

Icariin targets PDE5A to regulate viability, DNA synthesis and DNA damage of spermatogonial stem cells and improves reproductive capacity

ABSTRACT

Icariin is a pure compound derived from Epimedium brevicornu Maxim, and it helps the regulation of male reproduction. Nevertheless, the role and underlying mechanisms of Icariin in mediating male germ cell development remain to be clarified. Here, we have demonstrated that Icariin promoted proliferation and DNA synthesis of mouse spermatogonial stem cells (SSCs). Furthermore, surface plasmon resonance iron (SPRi) and molecular docking (MOE) assays revealed that phosphodiesterase 5A (PDE5A) was an important target of Icariin in mouse SSCs. Mechanically, Icariin decreased the expression level of PDE5A. Interestingly, hydrogen peroxides (H2O2) enhanced the expression level of phosphorylation H2A.X (p-H2A.X), whereas Icariin diminished the expression level of p-H2A.X and DNA damage caused by H2O2 in mouse SSCs. Finally, our in vivo animal study indicated that Icariin protected male reproduction. Collectively, these results implicate that Icariin targets PDE5A to regulate mouse SSC viability and DNA damage and improves male reproductive capacity. This study thus sheds new insights into molecular mechanisms underlying the fate decisions of mammalian SSCs and offers a scientific basis for the clinical application of Icariin in male reproduction.

Abnormalities in mitochondrial energy metabolism induced by cryopreservation negatively affect goat sperm motility

The motility of sperm decreases following cryopreservation, which is closely associated with mitochondrial function. However, the alterations in mitochondrial metabolism after sperm freezing in goats remain unclear. This experiment aimed to investigate the impact of ultra-low temperature freezing on goat sperm's mitochondrial energy metabolism and its potential correlation with sperm motility. The results revealed that goat sperm exhibited mitochondrial vacuolization, reduced matrix density, and significantly decreased levels of high-membrane potential mitochondria and adenosine triphosphate content, accompanied by a substantial increase in reactive oxygen species levels, ultimately leading to a significant decline in sperm viability. Further investigations unveiled that energy-related differential metabolites (capric acid, creatine, and D-glucosamine-6-phosphate) and differential metabolites with antioxidant effects (saikosaponin A, probucol, and cholesterol sulfate) were significantly downregulated. In addition, the activity of key rate-limiting enzymes involved in very long-chain fatty acid biosynthesis and β-oxidation-specifically acetyl-CoA carboxylase, fatty acid synthase, and carnitine palmitoyltransferase I related to capric acid metabolism-was considerably reduced. Furthermore, supplementation of differential metabolite capric acid (500 μM) significantly enhanced the motility of frozen-thawed goat sperm. These findings indicated that the mitochondrial ultrastructure of goat sperm is damaged and energy metabolism becomes abnormal after cryopreservation, potentially affecting sperm viability. The addition of different metabolites such as capric acid to the freezing extender can alleviate the decrease in sperm motility induced by cryopreservation.

Epiberberine ameliorates MNNG-induced chronic atrophic gastritis by acting on the EGFR-IL33 axis

Chronic atrophic gastritis (CAG) is a prevalent form of chronic gastritis that presents with chronic inflammation of the gastric mucosa, localised gastric mucosal glandular atrophy and intestinal metaplasia. Despite the existence of diagnostic criteria, effective therapeutic strategies for this condition remain to be developed. The objective of this study was to examine the potential therapeutic benefits of epiberberine in mitigating MNNG-induced CAG and to elucidate the underlying mechanisms. MNNG was employed to establish a CAG mouse model and a GES-1 cell model, and EPI was observed to be efficacious in ameliorating the gastric mucosal injury and inflammatory infiltration induced by MNNG in the CAG model mice, a finding that was subsequently validated in the GES-1 model cells. Bioinformatics analysis indicated that EPI may exert a direct effect on EGFR, thereby regulating the expression of IL-33 and thereby achieving the therapeutic effect of CAG. This hypothesis was also validated by molecular docking prediction, CETSA, and overexpression of EGFR in GES-1 model cells, using EGFR agonists and inhibitors to further demonstrate that EPI may act as an antagonist supplement to EGFR for the treatment of CAG.

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.

Unveiling the Emerging Role of Klotho: A Comprehensive Narrative Review of an Anti-aging Factor in Human Fertility

Klotho, an anti-aging protein, plays a vital role in diverse biological functions, such as regulating calcium and vitamin D levels, preventing chronic fibrosis, acting as an antioxidant and anti-inflammatory agent, safeguarding against cardiovascular and neurodegenerative conditions, as well as exerting anti-apoptotic, anti-senescence effects. Additionally, it contributes to metabolic processes associated with diabetes and exhibits anti-cancer properties. This protein is commonly expressed in organs, such as kidneys, brain, pancreas, parathyroid glands, ovaries, and testes. Recent research has highlighted its significance in human fertility. This narrative review provides insight into the involvement of Klotho protein in male and female fertility, as well as its potential role in managing human infertility in the future. In this study, a search was conducted on literature spanning from November 1997 to June 2024 across multiple databases, including PUBMED, SCOPUS, and Google Scholar, focusing on Klotho proteins. The search utilized keywords, such as "discovery of Klotho proteins," "Biological functions of Klotho," "Klotho in female fertility," "Klotho and PCOS," "Klotho and cryopreservation," and "Klotho in male infertility." Inclusion criteria comprised full-length original or review articles, as well as abstracts, discussing the role of Klotho protein in human fertility, published in English in various peer-reviewed journals. Exclusion criteria involved articles published in languages other than English. Hence, due to its anti-aging characteristics, Klotho protein presents potential roles in male and female fertility and holds promising prospects for reproductive medicine. Further, it holds the potential to become a valuable asset in addressing infertility concerns for both males and females.

Progress in the Study of TAp73 and Sperm Apoptosis

The study of the mechanism of oligoasthenospermia, which is a major cause of male infertility, has been the focus of research in the field of male reproduction. TAp73, a member of the p53 family of oncogenes, is endowed with tumor-suppressing activity due to its structural and functional homology with p53. It has been found that TAp73, plays a key role in spermatogenesis and maintaining male reproduction. When TAp73 is low-expressed or absent, the process of spermatogenesis is severely impaired, and mice deficient in TAp73 exhibit spermatogonial DNA damage, disturbed apical cytoplasmic specialization, and spermatocyte malformations resulting in reduced male fertility. Nevertheless, when TAp73 is overexpressed, it not only drives exogenous death receptors to regulate germ cell apoptosis, but also interacts with its various substrate proteins to promote the translocation of cytoplasmic Bax proteins to the mitochondria, resulting in the upregulation of the Bax/Bcl-2 ratio on the mitochondrial membrane and triggering a series of mitochondrial apoptotic effects. In this article, we will analyze the mechanism of TAp73 and sperm apoptosis, and elaborate the mechanism of TAp73 upregulation, exogenous apoptosis pathway and mitochondrial apoptosis pathway to systematically explain that the process of apoptosis induced by high expression of TAp73 is not fixed and single, but is interconnected, so as to provide a basis for the treatment of oligoasthenospermia and the research and development of new drugs using TAp73 as a target.

Role of Lipoic Acid in Testosterone Production in Males

Testosterone extends its impact beyond sexual function, playing a crucial role in shaping overall male health, including aspects such as muscle mass, bone density, mood regulation, and energy levels. Lipoic acid, a cofactor for specific enzymes, particularly dehydrogenases involved in cellular energy production, has been studied for its impact on testosterone. This comprehensive review systematically scoured PubMed and Scopus databases using the keywords "lipoic acid" and "testosterone." It encompassed all relevant English papers published from November 1971 to the present, including full texts and abstracts, along with research elucidating the biochemical mechanisms linking lipoic acid to testosterone. In summary, lipoic acid consistently restores testosterone levels, offering promise as an intervention in testicular health, especially in cases of testicular toxicity caused by various harmful agents. Its mechanisms encompass nitric oxide enhancement, fortification of testicular antioxidants, elevation of luteinizing hormone, enhancement of steroidogenesis, and the maintenance of energy production. These mechanisms underscore the therapeutic potential of lipoic acid for testicular health.

Simple and rapid multicolor sensor for seminal plasma ROS detection based on synergistic catalytic etching of gold nanobipyramids dopped agarose composite gel

Excessive reactive oxygen species (ROS) in seminal plasma can trigger male infertility. Therefore, the development of simple and rapid ROS detection methods is urgently needed, particularly for the early self-screening of preconception couples. Herein, a gold nanobipyramid (Au NBP)-based colorimetric hydrogel for convenient and fast ROS detection is described. In the hydrogel, Au NBP is etched efficiently by ROS under the synergistic effect of Fe2+and I-, which finally causes color variations. Besides, agarose gel with the function of molecular sieve enables the separation of biomacromolecules, improving the interference resistance of the system and the stability of Au NBP. This chemical sensor can complete all the tests within 20 min, covering two detection range of 10-125 μM at relative low H2O2 concentration and 125-1000 μM at relative high H2O2 concentration, with the detection limits of 1.76 μM and 12.10 μM (S/N = 3) respectively. Furthermore, via visual observation of the color variations, it allows the initial interpretation of ROS concentration without any additional equipment. We applied this device to the detection of ROS in clinical seminal plasma samples and obtained promising results, demonstrating its potential for rapid and convenient detection in clinical applications.

Selenium-Enriched Aspergillus oryzae A02 Enhances Testicular Antioxidant Capacity in Mice by Regulating Intestinal Microbiota and Serum Metabolite

Selenium (Se) is a trace element that is essential for health. Organic Se created by Se-enriched microorganisms has the characteristics of low toxicity, high bioavailability, and regulation of physiological functions. Here, the regulatory effect of Se-enriched Aspergillus oryzae A02 on the reproductive function of male mice and its potential molecular mechanism was studied. Specifically, twenty-four male mice were randomly divided into a control group and a Se-enriched A. oryzae A02 (Nano-Se) (daily gavage of 0.5 mg/kg, dissolved in saline) for an 8-week experiment. The results showed that Nano-Se intervention did not affect body weight and testicular index, but increased sperm concentration and seminiferous epithelium height in experimental mice, indicating that Nano-Se has the potential to improve the reproductive performance of male mice. Mechanistically, Nano-Se intervention increased the levels of antioxidant-related indicators catalase (CAT) and glutathione peroxidase (GSH-Px) in mouse serum, and increased the relative mRNA expression of GSH-Px, heme oxygenase-1 (HO-1), and NADPH quinine oxidoreductase-1 (NQO-1) in testicular tissues. We identified 9,10,13-trihydroxyoctadecenoic acids (TriHOMEs), stearidonic acid and selenomethionine linked with alpha-linolenic acid metabolism, selenocompound metabolism, folate biosynthesis, ubiquinone, and other terpenoid-quinone biosynthesis and biosynthesis of cofactors. In addition, Nano-Se did not influence the fecal bacterial alpha and beta diversity (P > 0.05), but increased the abundance of the Actinobacteriota and Proteobacteria phyla and the Staphylococcus and Corynebacterium genera, and lowered the abundance of the Bacteroidota phylum and the Lactobacillus and norank_f_Muribaculaceae genera. Nano-Se is considered a novel and promising nutritional regulator to improve reproductive function.

Cyberpharmacology uncover the mechanism of the total Rhizoma Coptidis extracts ameliorate chronic atrophic gastritis

ETHNOPHARMACOLOGICAL RELEVANCE

Characterized by inflammation of the gastric mucosa, atrophy of gastric gland cells, and intestinal metaplasia, Chronic Atrophic Gastritis (CAG) is a precancerous lesion disease. In traditional Chinese medicine, Rhizoma Coptidis (RC) is extensively used for treating gastrointestinal disorders, mainly because RC alkaloids-based extracts are the main active pharmaceutical ingredients. Total Rhizoma Coptidis extracts (TRCE) is a mixture of Rhizoma Coptidis extracts from Rhizoma Coptidis with alkaloids as the main components. However, the efficacy and mechanism of TRCE on CAG need further study.

AIM OF THE STUDY

To explore the therapeutic effect and underlying mechanisms of action of TRCE on N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)-induced chronic atrophic gastritis (CAG) using network pharmacological analysis.

MATERIALS AND METHODS

The amelioration effect of TRCE on CAG was evaluated in MNNG-induced CAG mice. The pathological severity of the mice was evaluated through H&E staining. Detection of gastric mucosal parietal cell loss was conducted using immunofluorescence staining, and serum indices were measured using ELISA. Additionally, the active compounds and drug targets of Rhizoma Coptidis were curated from the STP, SEA, and TCMSP databases, alongside disease targets of CAG sourced from PharmGkb, OMIM, and GeneCards databases. By mapping drug targets to disease targets, overlapping targets were identified. A shared protein-protein interaction (PPI) and drug target network were constructed for the overlapping targets and analyzed for KEGG enrichment.

RESULTS

The results of animal experiments demonstrate that TRCE has the potential to improve the CAG process in mice. In conjunction with disease characteristics, cyberpharmacology analysis has identified nine core compounds, 151 targets, 10 core targets, and five significant inflammatory pathways within the compound-target-pathway network. Furthermore, there is a remarkable coincidence rate of 98% between the core compound targets of TRCE and the targets present in the CAG disease database. The accurate search and calculation of literature reports indicate that the coverage rate for 121 predicted core targets related to CAG reaches 81%. The primary characteristic of CAG lies in its inflammatory process. Both predicted and experimental findings confirm that TRCE can regulate ten key inflammation-associated targets (TP53, STAT3, AKT1, HSP90AA1, TNF, IL-6, MAPK3, SRC, JUN, and HSP90AA1) as well as inflammation-related pathways (MAPK, HIF-1, Toll-Like Receptor, IL-17, TNF, and other signaling pathways). These mechanisms mitigate inflammation and reduce gastric mucosal damage in CAG mice.

CONCLUSIONS

In conclusion, TRCE was shown to alleviate CAG by modulating TP53, STAT3, AKT1, HSP90AA1, TNF, IL-6, MAPK3, SRC, JUN, and EGFR, as demonstrated by combined network pharmacology and biological experiments. In conclusion, our study provides a robust foundation for future clinical trials evaluating the efficacy of RC in treating CAG.

Therapeutic potential of diosgenin against methotrexate-induced testicular damage in the rat

This study evaluated diosgenin effects on methotrexate-induced testicular injury in the rats. A single dose of methotrexate (MTX) (20 mg/kg, i.p) was administered, followed by two weeks of diosgenin treatment via gavage starting one day before methotrexate injection. Testicular damage was evaluated through histological examination of seminiferous tubules, as well as analysis of serum testosterone level, oxidative stress and inflammation biomarkers, and antioxidant levels. The results of this study showed that in the MTX-exposed group, oxidative stress indices of malondialdehyde (MDA), reactive oxygen species (ROS), nitrite and indices of inflammation consisting of tumor necrosis factor α (TNFα), and interleukin 6 (IL-6) have a significant increase compared to the control group. Additionally, reductions were observed in antioxidant enzymes including superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH). In addition, testosterone level decreased and signs of testicular damage were observed in the MTX group. Conversely, in the group treated with diosgenin alongside MTX at a dosage of 50 mg/kg, there was a significant decrease in oxidative stress markers (MDA, ROS, nitrite) and inflammatory markers (TNFα and IL-6). Moreover, there was a significant increase in the levels of antioxidant enzymes (SOD, CAT, and GSH). Diosgenin appears to have the potential to protect testicular tissue from damage caused by the toxic effects of MTX through the reduction of oxidative stress and inflammation.

Carnitine traffic and human fertility

Carnitine is a vital molecule in human metabolism, prominently involved in fatty acid β-oxidation within mitochondria. Predominantly sourced from dietary intake, carnitine also derives from endogenous synthesis. This review delves into the complex network of carnitine transport and distribution, emphasizing its pivotal role in human fertility. Together with its role in fatty acid oxidation, carnitine modulates the acety-CoA/CoA ratio, influencing carbohydrate metabolism, lipid biosynthesis, and gene expression. The intricate regulation of carnitine homeostasis involves a network of membrane transporters, notably OCTN2, which is central in its absorption, reabsorption, and distribution. OCTN2 dysfunction, results in Primary Carnitine Deficiency (PCD), characterized by systemic carnitine depletion and severe clinical manifestations, including fertility issues. In the male reproductive system, carnitine is crucial for sperm maturation and motility. In the female reproductive system, carnitine supports mitochondrial function necessary for oocyte quality, folliculogenesis, and embryonic development. Indeed, deficiencies in carnitine or its transporters have been linked to asthenozoospermia, reduced sperm quality, and suboptimal fertility outcomes in couples. Moreover, the antioxidant properties of carnitine protect spermatozoa from oxidative stress and help in managing conditions like polycystic ovary syndrome (PCOS) and endometriosis, enhancing sperm viability and fertilization potential of oocytes. This review summarizes the key role of membrane transporters in guaranteeing carnitine homeostasis with a special focus on the implications in fertility and possible treatments of infertility and other related disorders.

Consumption of Ultra-Processed Foods and Semen Quality in Healthy Young Men Living in Italy

BACKGROUND/OBJECTIVES

The study aim was to evaluate the association between UPF consumption and semen quality in a sample of healthy young men in Italy.

METHODS

A cross-sectional analysis was carried out using data from 126 participants (mean age ± SD 20.0 ± 1.2 years) enrolled in the FASt randomized controlled trial. Food intake was assessed through the European Prospective Investigation into Cancer and Nutrition (EPIC) FFQ. Food items were categorized according to the Nova classification based on their purpose and extent of processing as follows: (1) unprocessed/minimally processed foods; (2) processed culinary ingredients; (3) processed foods; and (4) UPFs. The weight ratio (%) between each Nova group (g/d) and total food (g/d) was then calculated. For semen analyses, sperm volume, concentration, motility and morphology were measured. The associations between UPF consumption (quarters of) and semen quality parameters were estimated using multivariable-adjusted linear regression models.

RESULTS

Participants consuming high UPFs (Q4), compared to those in the bottom category of intake (Q1), had a lower sperm concentration (β = -54.16 × 106 cell/mL; 95%CI: -92.91 to -15.40; p for trend = 0.0020 across fourths) and progressive motility (β = -14.17%; 95%CI: -28.25 to -0.09; p for trend = 0.036). The percentage of normal morphology cells had a tendency to decrease amongst subjects consuming more UPFs compared to those with the lowest intake.

CONCLUSIONS

A large dietary intake of UPFs was inversely associated with sperm concentration and progressive motility in reproductive-age men. These findings suggest that dietary recommendations for improving male fertility and sperm health should also recommend limiting UPFs.

From Hypoxia to Oxidative Stress: Antioxidants' Role to Reduce Male Reproductive Damage

Hypoxia is one of the main reasons causing male reproductive damage for people living in high altitude. Pathological evidences have been presented both in humans and animal models. Spermatogenesis disruption, worse sperm parameters, hormone disorder and erectile dysfunction are emblematic of male reproductive impairments brought by hypoxia. Among many mechanisms impairing male reproductive systems, oxidative stress is always a field of interest to explore. Although previous reviews have discussed about hypoxia or oxidative stress and antioxidants on male fertility respectively, no one has elucidated the concrete role of oxidative stress in hypoxia and correlating antioxidants that can ameliorate the negative effects. In this review, we firstly introduce hypoxia etiology and describe specific damage of hypoxia on male reproductive functions. Then, we emphasized interplays between hypoxia and oxidative stress as well as negative influences brought by oxidative stress. Finally, we listed antioxidants for oxidative stress and hypoxia-induced reproductive damage and discussed their controversial experimental effects for male infertility.

Lycium barbarum polysaccharide alleviates ferroptosis in Sertoli cells through NRF2/SLC7A11/GPX4 pathway and ameliorates DEHP-induced male reproductive damage in mice

Di-(2-ethylhexyl)phthalate (DEHP) is a common plasticizer that has been shown to significantly negatively affect male reproductive health. On the other hand, Lycium barbarum polysaccharide (LBP) has been shown to improve reproductive function. Therefore, we hypothesized that LBP may ameliorate DEHP-induced male reproductive damage. Herein, we found that LBP could alleviate DEHP-induced testicular damage and sperm abnormalities. Furthermore, histomorphological analysis of mice testis revealed that LBP primarily ameliorated the DEHP-induced male reproductive damage by targeting Sertoli cells. Moreover, the detection of the function-related genes of Sertoli cells confirmed this finding. The serum of mice in the Control, DEHP, and DEHP+LBP groups was analyzed using non-targeted metabolomics to further elucidate the mechanism of action of LBP in improving DEHP-induced male reproductive damage. According to the results, the differential metabolites were mainly enriched in the glutamate metabolism pathway, implying that LBP may alleviate the ferroptosis-related DEHP-induced testicular injury. Related ferroptosis markers were also found in mice testis. These findings collectively suggest that LBP may ameliorate DEHP-induced testicular injury via alleviating ferroptosis in Sertoli cells. To clarify the specific mechanism, we constructed a cell model in vitro by treating TM4 cells (the Sertoli cell line) with LBP and MEHP (the in vivo DEHP metabolite). Our findings revealed that LBP can improve the function of DEHP-affected Sertoli cells. Furthermore, the analysis of lipid peroxidation, Fe2+ content, and ferroptosis-related protein expressions demonstrated that LBP could ameliorate MEHP-induced ferroptosis in TM4 cells. To clarify the specific mechanism, glutamate metabolism-related proteins involved in the ferroptosis pathway were detected. According to the results, there were significant changes in the expression of NRF2, SLC7A11 and GPX4 proteins, which are involved in the ferroptosis glutamate metabolism pathway. Furthermore, supplementation of NRF2, SLC7A11, and GPX4 inhibitors (ML385, Erastin, and RSL3, respectively) blocked the therapeutic effect of LBP in alleviating MEHP-induced ferroptosis in TM4 cells, implying that LBP could also ameliorate MEHP-induced ferroptosis via the NRF2/SLC7A11/GPX4 pathway. In summary, these findings show that LBP can alleviate DEHP/MEHP-induced ferroptosis through the NRF2/SLC7A11/GPX4 pathway, ameliorating Sertoli cell dysfunction and improving the DEHP-induced male reproductive damage. Therefore, the clinical administration of LBP could be an effective strategy for preventing DEHP-induced male reproductive injury.

Immunoregulation and male reproductive function: Impacts and mechanistic insights into inflammation

This paper investigates the complex relationship between the immune system and male reproductive processes, emphasizing how chronic inflammation can adversely affect male reproductive health. The immune system plays a dual role; it protects and regulates reproductive organs and spermatogenesis while maintaining reproductive health through immune privilege in the testes and the activities of various immune cells and cytokines. However, when chronic inflammation persists or intensifies, it can disrupt this balance, leading to immune attacks on reproductive tissues and resulting in infertility.This study provides a detailed analysis of how chronic inflammation can impair sperm production, sperm quality, and the secretion of gonadal hormones both directly and indirectly. It also delves into the critical roles of testicular immune privilege, various immune cells, and cytokines in sustaining reproductive health and examines the impacts of infections, autoimmune diseases, and environmental factors on male fertility.

Environmental high temperature affects pre-implantation embryo development by impairing the DNA repair ability

Environmental high temperature poses a significant threat to human health, however, limited information is available for understanding the relationship between the hot weather and infertility. This study aims to assess the adverse effect of the hot weather to early embryonic cells. Our results indicated that environmental high temperature exposure could cause the decline of early embryo quality and implantation ability. In detail, it led to early embryonic development retardation, embryo degeneration rate increased, the rate of blastocyst and hatching decreased, and reduced the number of implants. And the finding also the impairment of environmental high temperature on early embryonic cells may be due to oxidative damage of DNA caused by ROS, while BER repair ability is decreased, failing to repair oxidative damage of DNA in time, resulting in a large number of early embryonic apoptosis. The work underscored that pregnant women should stay away from high-temperature environments.

Impact of dietary antioxidants on female infertility risk: evidence from NHANES

The composite dietary antioxidant index (CDAI) serves as a valuable instrument for evaluating the intake of dietary antioxidants. This research aims to clarify the connection between CDAI and the risk of female infertility by analyzing data from the National Health and Nutrition Examination Survey from 2013 to 2018. Participants underwent two 24-h dietary recall interviews to calculate CDAI. Female infertility was determined through two questionnaires. Logistic regression model, restricted cubic spline and subgroup analysis were employed to examine the association between CDAI and female infertility. The study encompassed 2162 participants. Participants with female infertility had lower CDAI levels compared to those without. Following adjustment for confounding variables, a negative association between CDAI levels and female infertility was observed (Q4 vs. Q1, OR [95% CI] 0.392 [0.193, 0.795], P = 0.016). RCS demonstrated a statistically significant linear negative relationship between CDAI and female infertility. Subgroup analysis showed no significant interaction. This study illustrates a negative link between the CDAI and female infertility, indicating that higher consumption of dietary antioxidants may be associated with a reduced risk of female infertility. Additional rigorously designed prospective studies are necessary to validate these results.

Palmatine ameliorates N-methyl-N'-nitrosoguanidine-induced chronic atrophic gastritis through the STAT1/CXCL10 axis

Chronic atrophic gastritis (CAG) is a prevalent preneoplastic condition of the stomach. Palmatine (PAL), an isoquinoline alkaloid isolated from Rhizoma Coptidis (RC), has significant anti-inflammatory properties and is often used to treat gastrointestinal disorders. However, the mechanism of PAL on CAG remains unclear. In this study, N-methyl-N'-nitrosoguanidine (MNNG) was used to induce CAG inflammatory disease models in vivo and in vitro. The efficacy of five alkaloids in RC and the dose-dependent effects of the most effective PAL in CAG mice were evaluated in two animal experiments. RNA-seq and western blot revealed that PAL significantly improved IL-17, TNF, and NF-kappa B inflammation-related signaling pathways. Further hub gene prediction and experimental validation revealed that PAL modulated the STAT1/CXCL10 axis, thereby exerting attenuation of CAG through the regulation of IL-17, TNF-α, and p-p65 expression. In conclusion, PAL was proposed to mitigate MNNG-induced CAG, potentially through the inhibition of oxidative stress and inflammatory responses via the STAT1/CXCL10 axis. This approach is an effective complement to the use of PAL in the treatment of CAG.

Rosolic acid as a novel activator of the Nrf2/ARE pathway in arsenic-induced male reproductive toxicity: An in silico study

Male reproductive toxicity as a result of arsenic exposure is linked with oxidative stress and excessive generation of reactive oxygen species (ROS). It leads to an imbalance between ROS production and antioxidant defense mechanisms ultimately resulting in male infertility. The nuclear factor erythroid 2 (NFE2)-related factor 2 (Nrf2) is a transcription factor that responds to cellular stressors controlling the oxidative state, mitochondrial dysfunction, inflammation, and proteostasis. This study aims to investigate the potential of Rosolic acid (ROA) to act as a novel Nrf2 activator by mitigating oxidative stress to combat arsenic-induced male reproductive toxicity. The protein and ligands were prepared in the BIOVIA Discovery Studio, followed by protein-ligand docking using auto dock vina integrated with the PyRx-Virtual Screening Tool. Then the ADME properties were analyzed using the SwissADME tool to get a clear idea about the physicochemical properties, lipophilicity, water solubility, pharmacokinetics, and drug likeliness of ROA. It was followed by molecular dynamics simulation (MDS) studies using GROMACS. The 3D and 2D interaction maps revealed the interactions of Keap 1 with ROA. Keap1-ROA complex was found to have a binding energy of -7.8 kcal/mol. ROA showed 0 violations for Lipinski and 0 alerts each for PAINS and Brenk and a bioavailability score of 0.55. The BOILED-Egg representation showcases that ROA is predicted as passively crossing the blood-brain barrier (BBB). The MDS described 2FLU-ROA as a stable system. This work portrays that ROA can be a potent Nrf2 activator by exhibiting an inhibitory activity against the Keap1 protein and thus mitigating oxidative stress in arsenic-induced male reproductive toxicity.

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.

Vigor King mitigates spermatogenic disorders caused by environmental estrogen zearalenone exposure

Zearalenone (ZEN) has been shown to cause reproductive damage by inducing oxidative stress. Astaxanthin and L-carnitine are widely used to alleviate oxidative stress and promote sperm maturation. However, it remains uncertain whether they are effective in mitigating spermatogenesis disorders induced by ZEN. This study aimed to investigate the therapeutic efficacy and potential mechanisms of Vigor King (Vig), a compound preparation primarily consisting of astaxanthin and L-carnitine, in alleviating ZEN-induced spermatogenesis disorders. In the experiment, mice received continuous oral gavage of ZEN (80 μg/kg) for 35 days, accompanied by a rescue strategy with Vig (200 mg/kg). The results showed that Vig effectively reduced the negative impact on semen quality and improved the structural and functional abnormalities of the seminiferous epithelium caused by ZEN. Additionally, the accumulation of reactive oxygen species (ROS), DNA double-strand breaks, apoptosis, and autophagy abnormalities were all significantly ameliorated. Intriguingly, the GSK3β-dependent BTRC-NRF2 signaling pathway was found to play an important role in this process. Furthermore, testing of offspring indicated that Vig could extend its protective effects to the next generation, effectively combating the transgenerational toxic effects of ZEN. In summary, our research suggests that Vig supplementation holds considerable promise in alleviating spermatogenesis disorders induced by zearalenone.

Seminal plasma S100A8/A9 as a potential biomarker of genital tract inflammation

ABSTRACT

Infections and inflammatory reactions in the male genital tract are the leading causes of male infertility with a prevalence of 6%-10%, primarily affecting testicular and epididymal function and ultimately compromising sperm quality. However, most infertile patients with genital infection/inflammation are asymptomatic and easily overlooked. Traditional indicators, including white blood cells, elastase, and other components in semen, can reflect inflammation of the genital tract, but there is still a lack of a uniform standard method of detection. Therefore, it is necessary to explore reliable markers in semen that reflect the inflammatory status of the genital tract. Using the experimental autoimmune orchitis (EAO) model to simulate noninfectious chronic orchitis, we successfully collected ejaculated seminal fluid from EAO rats using optimized electrical stimulation devices. Proteomic analysis was performed using isobaric tags for relative and absolute quantification (iTRAQ). Compared to the control group, 55 upregulated and 105 downregulated proteins were identified in seminal plasma samples from the EAO group. In a preliminary screening, the inflammation-related protein S100A8/A9 was upregulated. We further verified that S100A8/A9 was increased in seminal plasma and highly expressed in testicular macrophages of the EAO model. In patients with oligoasthenospermia and genital tract infections, we also found that S100A8/A9 levels were remarkably increased in seminal plasma and testicular macrophages. S100A8/A9 in semen may be a potential biomarker for chronic genital inflammation. Our study provides a new potential biomarker for early diagnosis and further understanding of male infertility caused by genital inflammation.

Protective effect of Chlorella vulgaris on testicular damage, sperm parameters, androgen production, apoptosis and oxidative stress index in male rats following doxorubicin administration

Doxorubicin (DOX) is a chemotherapy agent associated with adverse effects on male reproductive health. Chlorella vulgaris (ChV) is a potent natural antioxidant with promising applications in maintaining health and preventing oxidative stress-related diseases. The present study aimed to investigate the protective effect of ChV on DOX-induced testicular toxicity. Twenty-five Wistar rats (230 ± 20 g) were randomly assigned to five groups (n = 5), including the control group, sham group (received normal saline by oral gavage daily and intraperitoneally (IP) once a week), DOX group (3 mg/kg; once a week; IP), ChV group (300 mg/kg/day; by oral gavage), and DOX (3 mg/kg; once a week; IP) + ChV (300 mg/kg/day; by oral gavage) group. After 8 weeks of treatment, the rats were euthanized and serum testosterone level, testes histomorphometry, gonadosomatic index (GSI), apoptotic gene expression, oxidative stress index, and sperm parameters were assessed. The results showed that DOX led to a significant decrease in histological indexes, testosterone level, GSI, sperm parameters, and Bcl-2 gene expression and increased expression of P-53 and Bax genes, and oxidative stress markers (P<0.05). The administration of ChV in the DOX+ChV group significantly improved testosterone levels, sperm parameters, testicular tissue apoptosis, antioxidant enzymes, and structural integrity of the testes (P<0.05). The findings suggest that the co-administration of ChV can be a promising therapeutic agent to reduce the adverse effects of DOX on male reproductive performance.

Zinc and Its Impact on the Function of the Testicle and Epididymis

Zinc (Zn) is an essential trace element; it exhibits a plethora of physiological properties and biochemical functions. It plays a pivotal role in regulating the cell cycle, apoptosis, and DNA organization, as well as in protein, lipid, and carbohydrate metabolism. Among other important processes, Zn plays an essential role in reproductive health. The ZIP and ZnT proteins are responsible for the mobilization of Zn within the cell. Zn is an inert antioxidant through its interaction with a variety of proteins and enzymes to regulate the redox system, including metallothioneins (MTs), metalloenzymes, and gene regulatory proteins. The role of Zn in the reproductive system is of great importance; processes, such as spermatogenesis and sperm maturation that occur in the testicle and epididymis, respectively, depend on this element for their development and function. Zn modulates the synthesis of androgens, such as testosterone, for these reproductive processes, so Zn deficiency is related to alterations in sperm parameters that lead to male infertility.

Development of a thermotaxis and rheotaxis microfluidic device for motile spermatozoa sorting

Male infertility is a pervasive global reproductive challenge, primarily attributed to a decline in semen quality. Addressing this concern, there has been a growing focus on spermatozoa sorting in assisted reproductive technology. This study introduces a groundbreaking development in the form of a thermotaxis and rheotaxis microfluidic (TRMC) device designed for efficient motile spermatozoa sorting within a short 15-min timeframe. The TRMC device mimics the natural sperm sorting mechanism of the oviduct, selecting spermatozoa with superior motility and DNA integrity. The experimental outcomes demonstrate a remarkable enhancement in the percentage of progressive spermatozoa following sorting, soaring from 3.90% to an impressive 96.11% when subjected to a temperature decrease from 38 °C to 35 °C. Notably, sperm motility exhibited a substantial 69% improvement. The TRMC device exhibited a commendable recovery rate of 60.93%, surpassing current clinical requirements. Furthermore, the sorted spermatozoa displayed a notable reduction in the DNA fragmentation index to 6.94%, signifying a substantial 90% enhancement in DNA integrity. This remarkable advancement positions the TRMC device as highly suitable for applications in in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI), offering a promising solution to male infertility challenges.

Is oxidative stress - antioxidants imbalance the physiopathogenic core in pediatric obesity?

Despite the early recognition of obesity as an epidemic with global implications, research on its pathogenesis and therapeutic approach is still on the rise. The literature of the 21st century records an excess weight found in up to 1/3 of children. Both the determining factors and its systemic effects are multiple and variable. Regarding its involvement in the potentiation of cardio-vascular, pulmonary, digestive, metabolic, neuro-psychic or even dermatological diseases, the information is already broadly outlined. The connection between the underlying disease and the associated comorbidities seems to be partially attributable to oxidative stress. In addition to these, and in the light of the recent COVID-19 pandemic, the role played by oxidative stress in the induction, maintenance and potentiation of chronic inflammation among overweight children and adolescents becomes a topic of interest again. Thus, this review's purpose is to update general data on obesity, with an emphasis on the physiopathological mechanisms that underlie it and involve oxidative stress. At the same time, we briefly present the latest principles of pathology diagnosis and management. Among these, we will mainly emphasize the impact played by endogenous and exogenous antioxidants in the evolutionary course of pediatric obesity. In order to achieve our objectives, we will refer to the most recent studies published in the specialized literature.

Effect of dual tobacco smoking of hookah and cigarettes on semen parameters of infertile men

INTRODUCTION

The research regarding the effect of hookah smoking on health is still deficient, even though it has been proven to jeopardize human health by raising the hazard of different types of cancers, infections, and cardiovascular disease. We aimed to study the effect of dual tobacco smoking (hookah and cigarettes) on semen parameters of infertile men.

METHODS

In this cross-sectional study, we studied the effect of different types of smoking patterns on human semen parameters among men who visited IVF laboratories to do a seminal fluid analysis (SFA). A total number of 761 participants were included, divided into the following: 108 dual smokers, 219 hookah smokers, 222 cigarette smokers, and 212 non-smokers. To analyze the effect of dual smoking on normal morphology, an interaction term between the cigarette index and hookah index was used.

RESULTS

Multivariable regression analysis after adjustment for age, BMI, education level, children, chronic diseases, varicocele, testicular surgery history, infertility duration, and cause revealed no significant difference in the sperm concentration and the percentage of progressive motility between non-smokers, cigarette smokers, or hookah smokers. However, there was a significant difference in the log of normal morphology percentage between the three groups. Cigarette and hookah smoking were significantly associated with having lower percentages of normal morphology. There was a significant difference in the log-normal morphology %, where light and heavy dual smokers had the least exponential beta of log-normal morphology %, 0.43 (95% CI: 0.33-0.55) and 0.36 (95% CI: 0.24-0.53), respectively.

CONCLUSIONS

Dual tobacco smoking can adversely affect sperm morphology.

Recent Progress of Induced Spermatogenesis In Vitro

Sperm, a crucial gamete for reproduction in sexual reproduction, is generated through the proliferation, differentiation, and morphological transformations of spermatogonial stem cells within the specialized microenvironment of the testes. Replicating this environment artificially presents challenges. However, interdisciplinary advancements in physics, materials science, and cell engineering have facilitated the utilization of innovative materials, technologies, and structures for inducing in vitro sperm production. This article offers a comprehensive overview of research progress on inducing in vitro sperm production by categorizing techniques into two major systems based on matrix-based and non-matrix-based approaches, respectively. Detailed discussions are provided for both types of technology systems through comparisons of their similarities and differences, as well as research advancements. The aim is to provide researchers in this field with a comprehensive panoramic view while presenting our own perspectives and prospects.

Impact of chronic sleep deprivation on male reproductive health: Insights from testicular and epididymal responses in mice

BACKGROUND

Sleep deprivation (SD) can cause damage to the male reproductive system. However, the duration required for such damage and the specific sequence and severity of damage to the testis and epididymis remain unclear.

OBJECTIVE

To investigate the effects of different durations of SD on different parts of the testis and epididymis caput, corpus, and cauda.

METHODS

Adult ICR mice were randomly assigned to five groups: the SD group (SD for 18 h/day for 1, 2, 3, or 4 weeks), the SD + Vit E group (supplemented with Vit E 50 mg/kg/d during 4 weeks of SD, the SD+NS group (saline supplementation during 4 weeks of SD), the SD + RS group (5 weeks of recovery sleep after 4 weeks of SD), and a normal sleep control (Ctrl) group. Following the interventions, sperm parameters, testicular and epididymal histopathology, inflammatory response, and oxidative stress markers were compared between the groups.

RESULTS

Compared to the Ctrl group, the SD group showed a decrease in sperm motility and concentration from SD 2 W and SD 3 W, respectively. Decreases in sperm concentration and motility were more pronounced in the cauda compared to the caput and corpus. Pathological damage was less severe in the epididymis caput than in the corpus and cauda. After 4 weeks of SD, inflammation and oxidative stress increased in both testes and epididymis. Both sleep recovery and vitamin E supplementation showed significant improvements, though they did not fully reach the level of the Ctrl group.

CONCLUSION

Chronic SD for more than 2 weeks causes varying degrees of damage to the testis, epididymis caput, corpus, and cauda in male mice. This damage is not fully reversible after 5 weeks of sleep recovery and antioxidant stress treatment. These findings help us to identify and prevent SD damage to the male reproduction at an early stage.

A systematic review and meta-analysis of the placebo effect on both semen quality and male infertility

INTRODUCTION

Placebo influence on such objective indicators, as sperm quality and infertility, has not been studied previously, but some studies report that placebo may distort even objective outcomes. The aim of current study is to assess the placebo effect on fertility in patients suffering from sperm abnormalities and/or infertility.

EVIDENCE ACQUISITION

We conducted a search of two databases (Scopus and MEDLINE) and identified placebo-controlled clinical trials which focused on sperm abnormalities and/or male infertility treatment. Primary outcomes included changes in semen parameters (volume, total count, sperm concentration in semen, progressive motility, morphology (normal cells)). Secondary outcomes included DNA fragmentation and change in pregnancy rate.

EVIDENCE SYNTHESIS

Seventy-seven articles published from 1983 to 2022 were included. Statistically significant changes were observed for the following values: total sperm count, mean change 0.16 (95% CI 0.05, 0.26); P=0.004, I2=75.1%; and progressive motility, mean change 0.13 (95% CI 0.02, 0.24); P=0.026, I2=84.9%. In contrast, placebo did not affect sperm concentration, sperm volume, sperm morphology or DNA fragmentation index. The publication bias for all the values measured with Egger's test and funnel plots was low.

CONCLUSIONS

The current meta-analysis indicated a statistically significant increase of total sperm count and progressive motility in the placebo group. In contrast, placebo did not affect sperm concentration, sperm volume, sperm morphology and DNA fragmentation index. These findings should be considered while planning or analyzing placebo-controlled clinical trials.

Lipids, lipid-modified drug target genes, and the risk of male infertility: a Mendelian randomization study

Background

Previous observational studies have reported a possible association between circulating lipids and lipid-lowering drugs and male infertility (MIF), as well as the mediating role of circulating vitamin D. Then, due to issues such as bias, reverse causality, and residual confounding, inferring causal relationships from these studies may be challenging. Therefore, this study aims to explore the effects of circulating lipids and lipid-lowering drugs on MIF through Mendelian randomization (MR) analysis and evaluate the mediating role of vitamin D.

Method

Genetic variations related to lipid traits and the lipid-lowering effect of lipid modification targets are extracted from the Global Alliance for Lipid Genetics Genome-Wide Association Study. The summary statistics for MIF are from the FinnGen 9th edition. Using quantitative expression feature loci data from relevant organizations to obtain genetic variations related to gene expression level, further to explore the relationship between these target gene expression levels and MIF risk. Two-step MR analysis is used to explore the mediating role of vitamin D. Multiple sensitivity analysis methods (co-localization analysis, Egger intercept test, Cochrane's Q test, pleiotropy residuals and outliers (MR-PRESSO), and the leave-one-out method) are used to demonstrate the reliability of our results.

Result

In our study, we observed that lipid modification of four lipid-lowering drug targets was associated with MIF risk, the LDLR activator (equivalent to a 1-SD decrease in LDL-C) (OR=1.94, 95% CI 1.14-3.28, FDR=0.040), LPL activator (equivalent to a 1-SD decrease in TG) (OR=1.86, 95% CI 1.25-2.76, FDR=0.022), and CETP inhibitor (equivalent to a 1-SD increase in HDL-C) (OR=1.28, 95% CI 1.07-1.53, FDR=0.035) were associated with a higher risk of MIF. The HMGCR inhibitor (equivalent to a 1-SD decrease in LDL-C) was associated with a lower risk of MIF (OR=0.38, 95% CI 0.17-0.83, FDR=0.39). Lipid-modifying effects of three targets were partially mediated by serum vitamin D levels. Mediation was 0.035 (LDLR activator), 0.012 (LPL activator), and 0.030 (CETP inhibitor), with mediation ratios of 5.34% (LDLR activator), 1.94% (LPL activator), and 12.2% (CETP inhibitor), respectively. In addition, there was no evidence that lipid properties and lipid modification effects of six other lipid-lowering drug targets were associated with MIF risk. Multiple sensitivity analysis methods revealed insignificant evidence of bias arising from pleiotropy or genetic confounding.

Conclusion

This study did not support lipid traits (LDL-C, HDL-C, TG, Apo-A1, and Apo-B) as pathogenic risk factors for MIF. It emphasized that LPL, LDLR, CETP, and HMGCR were promising drug targets for improving male fertility.

Diquat causes mouse testis injury through inducing heme oxygenase-1-mediated ferroptosis in spermatogonia

Diquat dibromide (DQ) is a globally used herbicide in agriculture, and its overuse poses an important public health issue, including male reproductive toxicity in mammals. However, the effects and molecular mechanisms of DQ on testes are limited. In vivo experiments, mice were intraperitoneally injected with 8 or 10 mg/kg/ day of DQ for 28 days. It has been found that heme oxygenase-1 (HO-1) mediates DQ-induced ferroptosis in mouse spermatogonia, thereby damaging testicular development and spermatogenesis. Histopathologically, we found that DQ exposure caused seminiferous tubule disorders, reduced germ cells, and increased sperm malformation, in mice. Reactive oxygen species (ROS) staining of frozen section and transmission electron microscopy (TEM) displayed DQ promoted ROS generation and mitochondrial morphology alterations in mouse testes, suggesting that DQ treatment induced testicular oxidative stress. Subsequent RNA-sequencing further showed that DQ treatment might trigger ferroptosis pathway, attributed to disturbed glutathione metabolism and iron homeostasis in spermatogonia cells in vitro. Consistently, results of western blotting, measurements of MDA and ferrous iron, and ROS staining confirmed that DQ increased oxidative stress and lipid peroxidation, and accelerated ferrous iron accumulation both in vitro and in vivo. Moreover, inhibition of ferroptosis by deferoxamine (DFO) markedly ameliorated DQ-induced cell death and dysfunction. By RNA-sequencing, we found that the expression of HO-1 was significantly upregulated in DQ-treated spermatogonia, while ZnPP (a specific inhibitor of HO-1) blocked spermatogonia ferroptosis by balancing intracellular iron homeostasis. In mice, administration of the ferroptosis inhibitor ferrostatin-1 effectively restored the increase of HO-1 levels in the spermatogonia, prevented spermatogonia death, and alleviated the spermatogenesis disorders induced by DQ. Overall, these findings suggest that HO-1 mediates DQ-induced spermatogonia ferroptosis in mouse testes, and targeting HO-1 may be an effective protective strategy against male reproductive disorders induced by pesticides in agriculture.

Effect of Five Different Antioxidants on the Effectiveness of Goat Semen Cryopreservation

The effective combination of semen cryopreservation and artificial insemination has a positive effect on the conservation of germplasm resources, production and breeding, etc. However, during the process of semen cryopreservation, the sperm cells are very susceptible to different degrees of physical, chemical, and oxidative stress damage. Oxidative damage is the most important factor that reduces semen quality, which is affected by factors such as dilution equilibrium, change of osmotic pressure, cold shock, and enzyme action during the freezing-thawing process, which results in the aggregation of a large amount of reactive oxygen species (ROS) in sperm cells and affects the quality of semen after thawing. Therefore, the method of adding antioxidants to semen cryoprotective diluent is usually used to improve the effect of semen cryopreservation. The aim of this experiment was to investigate the effects of adding five antioxidants (GLP, Mito Q, NAC, SLS, and SDS) to semen cryoprotection diluent on the cryopreservation effect of semen from Saanen dairy goats. The optimal preservation concentrations were screened by detecting sperm viability, plasma membrane integrity, antioxidant capacity, and acrosomal enzyme activities after thawing, and the experimental results were as follows: the optimal concentrations of GLP, Mito Q, NAC, SLS, and SDS added to semen cryopreservation diluent at different concentrations were 0.8 mg/mL, 150 nmol/L, 0.6 mg/mL, 0.15 mg/ mL, 0.6 mg/mL, and 0.15 mg/mL. The optimal concentrations of the five antioxidants were added to the diluent and analyzed after 1 week of cryopreservation, and it was found that sperm viability, plasma membrane integrity, and mitochondrial activity were significantly enhanced after thawing compared with the control group (P < 0.05), and their antioxidant capacity was significantly enhanced (P < 0.05). Therefore, the addition of the above five antioxidants to goat sperm cryodilution solution had a better enhancement of sperm cryopreservation. This study provides a useful reference for exploring the improvement of goat semen cryoprotection effect.