Tracing of zinc and iron in experimentally induced varicocele: correlation with oxidative, nitrosative and carbonyl stress

Effect of quercetin and mirtazapine on spermatogenesis and testis structure in phenylhydrazine-induced hemolytic anemia mice: An experimental study

Anemia poses a significant healthcare challenge across different socioeconomic groups and can result in reproductive system damage through the generation of free radicals and lipid peroxidation. This study examines the protective effects of quercetin (QUE) and mirtazapine (MIR) against the reproductive damage caused by phenylhydrazine (PHZ) in mice. Fifty NMRI mice, aged 8-10 weeks with an average weight of 27.0 ± 2.0 g, were randomly divided into five groups. The control group (Group 1) received oral administration of 10 mL/kg/day of normal saline. Group 2 (PHZ group) received an initial intraperitoneal dose of 8 mg/100 g body weight of PHZ, followed by subsequent doses of 6 mg/100 g every 48 h. Group 3 received PHZ along with oral QUE at a dosage of 50 mg/kg/day. Group 4 received PHZ along with oral MIR at a dosage of 30 mg/kg/day. Group 5 received PHZ along with oral QUE at a dosage of 50 mg/kg/day and MIR at a dosage of 30 mg/kg/day. The treatment duration was 35 days. Sperm samples were collected from the caudal region of the epididymis post-euthanasia to assess the total mean sperm count, sperm viability, motility, DNA damage, and morphology. Testicular tissue was employed to quantify total antioxidant capacity (TAC), superoxide dismutase (SOD), glutathione peroxidase (GPx), and malondialdehyde (MDA) concentrations, while serum levels of testosterone, luteinizing hormone (LH), and follicle-stimulating hormone (FSH) were analyzed. Additionally, various aspects, including testicular histopathology, oxidative enzyme levels, gene expression related to apoptosis and antiapoptotic pathways, and in vivo fertility index, were evaluated after 35 days. The QUE, MIR, and QUE + MIR groups showed less abnormal morphology and DNA damage, as well as better total and progressive sperm motility, motility characteristics, viability, and plasma membrane function compared to the PHZ group. QUE, MIR, and QUE + MIR administration increased TAC, SOD, and GPx activities in testicular tissue, while reducing MDA levels compared to the PHZ group. Furthermore, QUE, MIR, and QUE + MIR significantly reduced Bax, and caspase-3 expression levels, and increased Bcl-2 expression levels, compared to the PHZ group. Mice treated with QUE, MIR, and QUE + MIR exhibited an increased in vivo fertility index and plasma sex hormone levels compared to the PHZ group. These results show that QUE, MIR, and QUE + MIR might be able to improve the fertility index, boost the testicular antioxidant defense system, and control the death of germ cells. This could mean that they could be used to treat mice with PHZ-induced testicular damage.

Don't wait any longer, conceive in time: a systematic review and meta-analysis based on semen parameters after varicocelectomy

BACKGROUND

Varicocelectomy was considered to be beneficial to patients with varicocele-related infertility. However, there are only a few researchers who have explored the relationship between better timing and postoperative semen improvement in patients.

METHODS

We conducted this meta-analysis by enrolling published prospective studies to find out the best waiting time after varicocelectomy to wait for better improvement of semen quality. An extensive search was conducted in PubMed, Web of Science, and Cochrane Library to identify eligible studies. The included studies were then analyzed comprehensively using STATA software and standardized mean differences (SMDs) and their corresponding 95% confidence intervals were calculated.

RESULTS

Our comprehensive analysis showed that after varicocelectomy, follow-up results within 3 months or longer showed a significant improvement in semen parameters compared to the preoperative period. Notably, no further improvement in semen parameters was observed when the follow-up period reached six months or longer (semen volume: WMD: - 0.07 (- 0.29, 0.16); sperm concentration: WMD: - 1.33 (- 2.33, - 4.99); sperm motility: WMD: 2.31 (- 0.55, 5.18); sperm morphology: WMD: 1.29 (- 0.66, 3.24); sperm total motile count: WMD: 3.95 (- 6.28, 14.19)).

CONCLUSIONS

Three months after varicocelectomy may be the optimal time for semen parameters compared to six months or even longer, which means it is also the preferable time for conception. However, more well-designed prospective studies are needed in the future to validate our conclusion.

Role of nuclear factor erythroid 2-related factor 2 (Nrf2) in female and male fertility

Oxidative stress refers to a condition where there is an imbalance between the production of reactive oxygen species and their removal by antioxidants. While the function of reactive oxygen species as specific second messengers under physiological conditions is necessary, their overproduction can lead to numerous instances of cell and tissue damage. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a master regulator of many cytoprotective genes that respond to redox stresses. Nrf2 is regularly degraded by kelch-like ECH-associated protein 1 through the ubiquitin-proteasome pathway. The kelch-like ECH-associated protein 1 and Nrf2 complex have attracted attention in both basic and clinical infertility research fields. Oxidative stress is implicated in the pathogenesis of female infertility, including primary ovarian insufficiency, polycystic ovarian syndrome, and endometriosis, as well as male infertility, namely varicocele, cryptorchidism, spermatic cord torsion, and orchitis. Most scientists believe that Nrf2 is a potential therapeutic method in female and male infertility disorders due to its antioxidant effect. Here, the potential roles of oxidative stress and Nrf2 in female and male infertility disorders are reviewed. Moreover, the key role of Nrf2 in the inhibition or induction of these diseases is discussed.

Trace and essential elements as vital components to improve the performance of the male reproductive system: Implications in cell signaling pathways

Successful male fertilization requires the main processes such as normal spermatogenesis, sperm capacitation, hyperactivation, and acrosome reaction. The progress of these processes depends on some endogenous and exogenous factors. So, the optimal level of ions and essential and rare elements such as selenium, zinc, copper, iron, manganese, calcium, and so on in various types of cells of the reproductive system could affect conception and male fertility rates. The function of trace elements in the male reproductive system could be exerted through some cellular and molecular processes, such as the management of active oxygen species, involvement in the action of membrane channels, regulation of enzyme activity, regulation of gene expression and hormone levels, and modulation of signaling cascades. In this review, we aim to summarize the available evidence on the role of trace elements in improving male reproductive performance. Also, special attention is paid to the cellular aspects and the involved molecular signaling cascades.

Effect of running exercise training on inflammatory mediators and cytokines expression in testicular tissue; effect of exercise intensity

The aim of this study is to investigate the impact of running exercise training protocols (ETPs) with varying intensities on inflammatory responses, with a specific focus on the interactions between inflammatory mediators, cytokines, and Leydig cell steroidogenic activity, as well as testosterone secretion. To this end, 24 Wistar rats were subdivided into sedentary control, low (LICT), moderate (MICT), and high (HICT) intensity continuous running ETP groups. After 8 weeks, the expression levels of Toll-like receptor-4 (TLR-4), nuclear factor-kappa-B (NF-KB), interleukin-6 (IL-6), interleukin-10 (IL-10), Tumor necrosis factor alpha (TNF-α), cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), and the testicular nitric oxide (NO) content were assessed and compared between groups. Moreover, the mean distributions of Leydig cells/mm2 of interstitial connective tissue, their steroidogenic activity, and serum level of testosterone were assessed. The LICT did not show any significant (p > 0.05) change in the expression levels of all aforementioned biomarkers. In contrast, both the MICT and HICT groups demonstrated a significant (p < 0.05) increase in the expression levels of TLR-4, NFK-B, IL-6, TNF-α, iNOS, and COX-2 at both the mRNA and protein levels. The testicular NO has increased in HICT and MICT groups. Despite a decrease in the distribution of Leydig cells in both the MICT and HICT groups, the HICT group exhibited a significant (p < 0.05) reduction in Leydig cell steroidogenic activity and serum testosterone levels. In conclusion, our findings revealed that ETPs can influence Leydig cell steroidogenic activity and testosterone secretion, contingent on their intensity. These effects are attributed to alterations in the expression levels of pro-inflammatory mediators and cytokines.

Oxidative Stress and Cell Cycle Arrest in Seminiferous Tubules Nearby Varicose Vessels: New Perspectives from Experimental Varicocele

Varicocele (VCL) has been shown to induce severe oxidative stress in the testicular tissue resulting in 35% of males with primary infertility. To compare the exacerbating impacts of varicose on oxidative DNA damage and homeostatic antioxidant reactions in the seminiferous tubules (ST), enclosed and far from varicose vessels. Thirty mature Wistar rats were divided into control and VCL-induced groups. To approve VCL, the testicular diameters, volume, and blood circulation were measured using B-mode and Doppler ultrasonography. Next, to confirm oxidative stress (OS), the global homeostatic antioxidant biomarkers were evaluated. Moreover, the OS-induced oxidative DNA damage and homeostatic antioxidant reactions were compared between STs nearby and far from varicose vessels. Finally, to clarify the DNA damage-induced impact on the cell cycle progression, the global and local expressions of Cyclin D1, Cdk4, and p21 were examined. The VCL-induced group exhibited diminished global antioxidant status (marked with TAC, GPX, SOD, and CAT) and UNG and MPG expression levels. Moreover, the cross-sections of the VCL group represented a prominent reduction in the UNG, MPG, Cyclin D1, and cdk4, and upregulation in the p21 expression levels, more prominently in the STs nearby varicose vessels. Concerning severe oxidative DNA damage and intensive molecular changes in the STs nearby the varicose vessels, they can be considered the main cause of oxidative DNA damage in enclosed tubules. Thus, the varicose-mediated oxidative DNA damage negatively impacts the cell cycle progression in the tubules more intensively in the subcapsular area.

Effects of alpha-lipoic acid on sperm quality in patients with varicocele-related male infertility: study protocol for a randomized controlled clinical trial

BACKGROUND

Varicocele is a high incidence and is considered to be the most common and correctable cause of male infertility. Oxidative stress (OS) plays a central role in the pathogenesis of varicocele-related male infertility. In addition to varicocelectomy, antioxidant supplementation seems to be an effective scheme for the treatment of varicocele-related male infertility, but it is still controversial. The purpose of this study is to determine the effects of alpha-lipoic acid (ALA) supplementation on sperm quality in patients with varicocele-related male infertility.

METHODS

In this randomized controlled clinical trial, we will randomize 80 patients with varicocele-related male infertility from Guilin People's Hospital. The non-surgical observation group (n = 20) will receive ALA, the non-surgical control group (n = 20) will receive vitamin E, the surgical observation group (n = 20) will receive ALA after the operation, and the surgical control group (n = 20) will receive vitamin E after the operation. The course of treatment will be 3 months. The results will compare the changes in semen parameters, sex hormones, testicular volume, sperm DNA fragment index (DFI), seminal plasma malondialdehyde (MDA), and total antioxidant capacity (TAC) between the groups at baseline and after 3 months of antioxidant supplementation.

DISCUSSION

Whether it is necessary to use antioxidants in varicocele-related male infertility, how potent antioxidants should be used, postoperative application or non-surgical independent application still needs to be explored. This study attempts to compare the effects of two antioxidants (ALA and vitamin E) on sperm quality in patients with varicocele-related male infertility (surgical or non-surgical) and attempted to answer the above questions.

TRIAL REGISTRATION

Chinese Clinical Trial Registry (ChiCTR) ChiCTR2100054958. Registered on 29 December 2021.

Varicocele associated male infertility: cellular and molecular perspectives of pathophysiology

BACKGROUND

Varicocele is a common risk factor associated with reduced male fertility potential. The current understanding of varicocele pathophysiology does not completely explain the clinical manifestation of infertility. The present treatment options such as antioxidant supplementation and varicocelectomy only helps ∼35% of men to achieve spontaneous pregnancy.

OBJECTIVE

This review aims to summarize the available knowledge on cellular and molecular alterations implicated to varicocele associated male infertility and also highlights the new knowledge generated by 'Omics' technologies.

MATERIALS AND METHODS

PubMed, MEDLINE, Cochrane and Google Scholar databases are searched using different combinations of keywords (varicocele, infertile/fertile men with varicocele, cellular changes, molecular mechanisms, proteome, epigenome, transcriptome and metabolome). A total of 229 relevant human and animal studies published till 2021 were included in this review.

RESULTS

Current understanding advocates oxidative stress (OS) as a major contributory factor to the varicocele associated male infertility. Excessive OS causes alteration in testicular microenvironment and sperm DNA fragmentation which further contributes to infertility. Molecular and omics studies have identified several promising biomarkers such as AAMP, SPINT1, MKI67 (genetic markers), sperm quality and function related protein markers, global sperm DNA methylation level (epigenetic marker), Hspa2, Protamine, Gadd7, Dynlt1 and Beclin1 (mRNA markers), PRDX2, HSPA, APOA2, YKL40 (seminal protein markers), total choline and PHGDH (metabolic markers).

DISCUSSION

Mature spermatozoa harbours a plethora of molecular information in form of proteome, epigenome and transcriptome; which could provide very important clues regarding pathophysiology of varicocele associated infertility. Recent molecular and omics studies in infertile men with varicocele have identified several promising biomarkers. Upon further validation with larger and well-defined studies, some of these biomarkers could aid in varicocele management.

CONCLUSION

The present evidences suggest inclusion of OS and sperm DNA fragmentation tests could be useful to the diagnostic workup for men with varicocele. Furthermore, including precise molecular markers may assist in diagnostics and prognostics of varicocele associated male infertility. This article is protected by copyright. All rights reserved.

Deferasirox, an Iron-Chelating Agent, Improves Testicular Morphometric and Sperm Functional Parameters in a Rat Model of Varicocele

Varicocele is characterized by testicular dysfunction that originates from hyperthermia and hypoxia, leading to defects in testicular tissue and altered spermatozoa structure and function. The varicocele testis is characterized by the presence of intracellular iron deposits that contribute to the associated oxidative stress. Therefore, we tested the hypothesis that administration of an iron-chelating agent, such as deferasirox (DFX), could potentially mitigate the consequences of varicocele on testicular tissue and spermatozoa. Using a well-established rat model of varicocele (VCL), we show that treatment with DFX partially improved the structure and function of the testis and spermatozoa. In particular, sperm motility was markedly restored whereas abnormal sperm morphology was only partially improved. No significant improvement in sperm count was observed that could be associated with the proapoptotic response observed following iron chelation treatment. No reduction in oxidative damage to spermatozoa was observed since lipid peroxidation and DNA integrity were not modified. This was suggested to be a result of increased oxidative stress. Finally, we also saw no indication of attenuation of the endoplasmic reticulum/unfolded protein (ER/UPR) stress response that we recently found associated with the VCL testis in rats.

Is ferroptosis involved in ROS-induced testicular lesions in a varicocele rat model?

BACKGROUND

Ferroptosis is an iron-dependent cell death that is distinct from apoptosis. Based on excessive amounts of iron and reactive oxygen species in varicocele (VCL) rats, we hypothesize that ferroptosis might be involved in VCL. In addition, since alpha-lipoic acid (ALA) was shown to have both antioxidant and anti-ferroptotic activity we assessed in the present work the status of ferroptosis in our varicocele model and the protective effect of ALA. To this end, 70 male Wistar rats were divided into 7 groups: control, sham and varicocele groups which were initially sacrificed 2 months after the operation to verify the induction of varicocele. A second batch of the same 3 groups were sacrificed 4 months after varicocele induction to evaluate the effect of ALA supplementation. The parameters measured were chromatin integrity (aniline blue and acridine orange staining), lipid peroxidation (BODIPY staining), testicular morphometry and iron content. In addition, redox (GSH and NADPH) and ferroptosis (Nrf2, Slc7a11, P53 and p-Jnk) markers were evaluated at 2 and 4 months post-operation.

RESULT

The alteration of the spermatic parameters made it possible to verify the induction of the varicocele. Iron accumulated well in the testicles during varicocele and decreased significantly following ALA treatment. Ferroptotic molecular markers at the mRNA and protein levels were not significantly altered. ALA supplementation did not alter NADPH values, but increased GSH levels.

CONCLUSION

Despite the increased accumulation of iron in the testes 2 and 4 months after surgical induction of varicocele, molecular evidence did not demonstrate the involvement of ferroptosis. This could be explained by the mosaic nature of the varicocele affecting some seminiferous tubules and not others which could mask variations in molecular markers. In parallel, our study confirms that ALA stimulates the NRF2 pathway.

Effects of monosodium glutamate on testicular structural and functional alterations induced by quinine therapy in rat: An experimental study

Background

Quinine (QU) as an anti-malarial drug induces alterations in testicular tissue. Toxic effects of monosodium glutamate (MSG) on the male reproductive system have been recognized.

Objective

To investigate the impact of MSG administration on the intensity of gonadotoxicity of QU.

Materials and Methods

Sixty eight-wk old Wistar rats weighing 180-200 gr were divided into six groups (n = 10/each): the first group as a control; the second and third groups received low and high doses of MSG (2 & 4 gr/kg i.p.), respectively, for 28 days; the fourth group received QU for seven days (25 mg/kg); and in the fifth and sixth groups, QU was gavaged following the MSG administration (MSG + QU) from day 22 to day 28. Serum testosterone and malondialdehyde (MDA) levels were measured. Testes samples were prepared for tissue MDA levels, histomorphometry, and immunohistochemistry of p53. Sperm analysis was performed on cauda epididymis.

Results

Serum and tissue MDA levels were increased in treated groups compared to the control group. This increment was higher in the MSG + QU groups. The testosterone levels were reduced significantly (p < 0.0001) in all treated groups. In addition, histomorphometric indices and tubular epithelium population were reduced significantly (p < 0.0001) in QU, MSG + QU, and consequently in high-dose MSG, QU, MSG + QU groups. All spermatogenic indices were reduced in the treated groups, particularly in the MSG + QU groups. Sperm motility and viability indices were reduced significantly (p = 0.003) in the MSG + QU groups. Finally, the overexpression of p53 was observed in the MSG + QU groups.

Conclusion

The administration of MSG before and during QU therapy may intensify testicular tissue alterations.

Platelet indices and varicocele: A systematic review and meta-analysis

The updated systematic review and meta-analysis was conducted to assess the platelet indices between patients with varicocele and healthy subject. The main purpose of our study was to explore the relationship between platelet and the pathogenesis of varicocele. Databases including Cochrane Library, PubMed, and MEDLINE were retrieved to identify studies. Two independent investigators extracted the related information of the included original passages. In order to estimate the difference of varicocele patients and healthy subjects, we applied the standardised mean difference (SMD) and the corresponding 95% confidence intervals (95% CIs). 1,156 patients and 797 healthy subjects of nine studies met the pre-set inclusion criteria. The estimated SMD in MPV between varicocele patients and healthy subjects was 0.61 (95% CI: 0.29-0.93, p < 0.001). The estimated SMD in MPV between preoperative varicocele patients and post-operative varicocele patients was 0.22 (95% CI: 0.03-0.41, p = 0.02). The estimated SMD in PLT between varicocele patients and healthy subjects was -0.19 (95% CI: -0.28, -0.08, p = 0.001). The available data suggest that a higher MPV level in varicocele patients, and the varicocele operation can normalise the preoperatively elevated mean platelet volume levels. Further researches are needed to investigate the potential role of platelet with varicocele.

Varicocoele and oxidative stress: New perspectives from animal and human studies

BACKGROUND

Varicocoele (VCL), one of the main causes of male subfertility, negatively affects testicular function. Due to limited access to human testicular tissue, animal model studies have been used to evaluate molecular and, recently, epigenetic changes attributed to pathophysiology induced by VCL.

OBJECTIVES

This review aims to provide an update on the latest findings regarding the link between VCL-induced biochemical stress and molecular changes in germ cells and spermatozoa. Endocrine and antioxidant status, testicular chaperone-specific hemostasis failure, altered testicular ion balance, metabolic disorders, and altered carbon cycling during spermatogenesis are among the many features that will be presented.

DISCUSSION

Literature review coupled with our own findings suggests that ionic imbalance, hypoxia, hyperthermia, and altered blood flow could lead to severe chronic oxidative and nitrosative stress in patients with VCL leading to defective spermatogenesis and impairment of the integrity of all sperm cell components and compartments down to the epigenetic information they carry.

CONCLUSION

Since oxidative stress is an important feature of the reproductive pathology of VCL, therapeutic strategies such as the administration of appropriate antioxidants could be undertaken as a complementary non-invasive treatment line.

Dietary supplements in the management of varicocele-induced infertility: A review of potential mechanisms

Varicocele is a main cause of lower production of spermatozoon and infertility with multiple pathophysiological mechanisms. In the past decades, the use of dietary supplements has significantly increased due to both the modern lifestyle and the food shortages of the industrialised countries. The purpose of this review paper is to collect scientific evidences from basic and clinical studies which support the use of dietary supplements to define the clinical framework for patients with varicocele. In the present review, we used keywords such as dietary supplements, varicocele, male infertility, oxidative stress, DNA fragmentation, sperm parameters to find the proper articles. The standard search biomedical engines were used for seeking the papers. The use of dietary supplements such as minerals, vitamins and antioxidants has an essential role in the prevention and treatment of varicocele by increasing the levels of antioxidant enzymes (e.g. peroxidase, superoxide dismutase and catalase) and decreasing the levels of inflammatory markers (e.g. tumour necrosis factor-α, interleukin-6 and interleukin-1) in testis. According to the results, the dietary supplements may alleviate the spermatogenesis in varicocele patients through different mechanisms such as suppression of stress oxidative and inflammation in testicular tissue.

Transcript Isoforms of SLC7A11-AS1 Are Associated With Varicocele-Related Male Infertility

Oxidative stress is one of the crucial mediators of varicocele-related male infertility. Recently, roles of long noncoding RNAs (lncRNAs) in oxidative stress have begun to emerge, however, little is known about their role in male infertility. The aim of this study was to determine the role of lncRNA SLC7A11-AS1 in varicocele-related male infertility. Through a high-throughput bioinformatics investigation, we predicted that lncRNA SLC7A11-AS1 might be involved in this type of infertility. The reactive oxygen species (ROS) levels and expression levels of SLC7A11-AS1 isoforms were evaluated in ejaculated spermatozoa of 25 infertile men with varicocele and 17 fertile individuals as control. Isoform 6 of SLC7A11-AS1 that showed a significant elevation in infertile men with varicocele relative to the fertile group was overexpressed in testicular-derived carcinoma cell lines (NT2 and NCCIT) followed by assessment of ROS, glutathione (GSH), lipid peroxidation, and cell viability. Overexpression of SLC7A11-AS1 isoform 6 in NT2 and NCCIT cell lines resulted in a significant downregulation of SLC7A11 gene expression, which consequently decreased GSH levels and concomitantly increased ROS levels and enhanced lipid peroxidation, which jeopardized cell survival and promoted cell death. Our finding revealed a potential role of oxidative-related lncRNAs in the pathophysiology of male infertility associated with varicocele.

Testosterone amplifies HSP70-2a, HSP90 and PCNA expression in experimental varicocele condition: Implication for DNA fragmentation

The DNA fragmentation and failure in post-meiotic maturation of the spermatozoa because of testosterone withdrawal can affect the fertilization potential in varicocele (VCL) patients. To find out the exact mechanism of VCL-induced failure in histone-protamine replacement process and DNA fragmentation, the correlations between the levels of expression of HSP70-2a, HSP90, PCNA, TP1/2 and PCNA genes and the patterns of DNA methylation were investigated before and after testosterone administration in rats. In total, 40 mature male Wistar rats (10 in each group) were assigned between control (with no intervention), control-sham (undergone a simple laparotomy), VCL-induced (VCL-sole), and testosterone-treated VCL-induced (VCLT) groups. The HSP70-2a, HSP90, PCNA, TP1, and TP2 genes expressions and the patterns of global DNA methylation were determined in all groups. A statistically significant (p < 0.05) reduction were found in the HSP70-2a, HSP90, PCNA, TP1 and TP2 genes expressions in VCL-sole group. In VCLT group, testosterone was shown to significantly (p < 0.05) up-regulate the HSP70-2a, HSP90, PCNA, and TP2expression levels, but TP1 expression has not been changed. Furthermore, the VCLT group exhibited higher DNA methylation rates compared to VCL-sole animals. In conclusion, testosterone, by up-regulating the HSP70-2a and HSP90 expressions and maintaining the pre-existing HSP70-2a and HSP90 proteins levels, may be the reason for the significant increment in TP2 expression during post-meiotic stage and can boost the global methylation rates of DNA via up-regulating the PCNA expression, suggesting that administration of testosterone can mitigate the VCL-impaired histone-protamine replacement and DNA methylation rates and protect the cellular DNA content from VCL-induced oxidative stress.

Differential cell death decisions in the testis: evidence for an exclusive window of ferroptosis in round spermatids

Oxidative stress is a major aetiology in many pathologies, including that of male infertility. Recent evidence in somatic cells has linked oxidative stress to the induction of a novel cell death modality termed ferroptosis. However, the induction of this iron-regulated, caspase-independent cell death pathway has never been explored outside of the soma. Ferroptosis is initiated through the inactivation of the lipid repair enzyme glutathione peroxidase 4 (GPX4) and is exacerbated by the activity of arachidonate 15-lipoxygenase (ALOX15), a lipoxygenase enzyme that facilitates lipid degradation. Here, we demonstrate that male germ cells of the mouse exhibit hallmarks of ferroptosis including; a caspase-independent decline in viability following exposure to oxidative stress conditions induced by the electrophile 4-hydroxynonenal or the ferroptosis activators (erastin and RSL3), as well as a reciprocal upregulation of ALOX15 and down regulation of GPX4 protein expression. Moreover, the round spermatid developmental stage may be sensitized to ferroptosis via the action of acyl-CoA synthetase long-chain family member 4 (ACSL4), which modifies membrane lipid composition in a manner favourable to lipid peroxidation. This work provides a clear impetus to explore the contribution of ferroptosis to the demise of germline cells during periods of acute stress in in vivo models.

Aberrant Upregulation of Compensatory Redox Molecular Machines May Contribute to Sperm Dysfunction in Infertile Men with Unilateral Varicocele: A Proteomic Insight

Aims: To understand the molecular pathways involved in oxidative stress (OS)-mediated sperm dysfunction against a hypoxic and hyperthermic microenvironment backdrop of varicocele through a proteomic approach. Results: Protein selection (261) based on their role in redox homeostasis and/or oxidative/hyperthermic/hypoxic stress response from the sperm proteome data set of unilateral varicocele (UV) in comparison with fertile control displayed 85 to be differentially expressed. Upregulation of cellular oxidant detoxification and glutathione and reduced nicotinamide adenine dinucleotide (NADH) metabolism accompanied with downregulation of protein folding, energy metabolism, and heat stress responses were observed in the UV group. Ingenuity pathway analysis (IPA) predicted suppression of oxidative phosphorylation (OXPHOS) (validated by Western blotting [WB]) along with augmentation in OS and mitochondrial dysfunction in UV. The top affected networks indicated by IPA involved heat shock proteins (HSPs: HSPA2 and HSP90B1). Their expression profile was corroborated by immunocytochemistry and WB. Hypoxia-inducible factor 1A as an upstream regulator of HSPs was predicted by MetaCore. Occurrence of reductive stress in UV spermatozoa was corroborated by thiol redox status. Innovation: This is the first evidence of a novel pathway showing aberrant redox homeostasis against chronic hypoxic insult in varicocele leading to sperm dysfunction. Conclusions: Upregulation of antioxidant system and dysfunctional OXPHOS would have shifted the redox balance of biological redox couples (GSH/GSSG, NAD⁺/NADH, and NADP⁺/NADPH) to a more reducing state leading to reductive stress. Chronic reductive stress-induced OS may be involved in sperm dysfunction in infertile men with UV, where the role of HSPs cannot be ignored. Intervention with antioxidant therapy warrants proper prior investigation.

Zeta and hyaluronic acid assessments, novel sperm selection procedures, in animal model for male infertility

Considering varicocele (VCL)-induced severe, progressive DNA damage, histone-protamine anomalies and low sperm production, in the current study, the experimental VCL was induced and the efficiency of hyaluronic acid (HA)-binding method (HABM) and zeta preparation procedure (ZPP) in selection of appropriate spermatozoa was compared with those spermatozoa from intact animals. Following 2 and 4 months, the histological alterations in testicular tissue, sperm count and viability were assessed to prove the VCL condition. The spermatozoa were undergone simple wash, HABM and ZPP. The chromatin condensation, active caspase-3 expression, DNA fragmentation and apoptosis index were analysed after applying selection techniques and compared with the spermatozoa from intact and VCL-induced animals, which were undergone a simple wash. Observations showed that both HABM and ZPP effectively prepared the spermatozoa with higher chromatin condensation and lower DNA damage. Meanwhile, the ZPP exerted a more preferable effect by preparing the spermatozoa with higher chromatin condensation, and lower caspase-3 expression, and DNA disintegrity versus the HABM, especially after 4 months. In conclusion, ZPP seems to exert much more reliable efficiency in selecting appropriate spermatozoa for ICSI processes, while more studies are needed to find out which one is more useful in the clinical assisted reproductive technique (ART) process.

Effect of aerobic exercise, low-fat and high-fat diet on the testis tissue and sperm parameters in obese and nonobese mice model

Semen quality and male fertility depend on numerous factors such as age, environment, lifestyle, physical activity, genetic background and occupation. We aimed to access the effect of aerobic exercise, low- and high-fat diet on mice testis tissue, and sperm function. Obese and nonobese male mice C57BL/6 were exposed to high fat (Hf) or low fat (Lf) and/or activity (Exe: exercise or Sed: sedentary). Finally, testicular morphometric characteristics, sperm concentration and motility (light microscopy), sperm morphology (eosin/nigrosin dye), lipid peroxidation (BODIPY C11 Probe), chromatin (acridine orange and chromomycin A3 staining) were compared within obese groups (Hf/Exe, Lf/Exe, Lf/Sed, Hf/Sed) and nonobese groups (Hf/Exe, Lf/Exe, Lf/Sed, Hf/Sed). Both exercise and diet interventions did not show any alteration in testicular morphological characteristics, sperm morphology and DNA fragmentation within both obese and nonobese groups (p > 0.05). Exercise and/or diet resulted in a significant increase in sperm concentration and motility within both groups (p < 0.05). Exercise in both groups leads to high percentage of lipid peroxidation (p < 0.05). Exercise intervention significantly improved sperm protamine deficiency within obese group (p < 0.05). We concluded that exercise intervention was more effective than diet in improvement of sperm function within obese groups.

Iron and a Man's Reproductive Health: the Good, the Bad, and the Ugly

PURPOSE OF REVIEW

To discuss the physiologic and pathologic effects of iron on men's reproductive health.

RECENT FINDINGS

Iron overload diseases are associated with hypogonadotropic hypogonadism, infertility, and sexual dysfunction in men. Recent findings have elucidated the roles by which iron may affect the male reproductive axis. Iron is requisite for life. Iron can also catalyze the production of reactive oxygen species. To maintain balance, the human body tightly regulates dietary iron absorption. Severe iron overload disorders-e.g., hereditary hemochromatosis and β-thalassemia-occur when these regulatory mechanisms are deficient. While iron is necessary, the male reproductive system is particularly sensitive to iron overload. Hypogonadotropic hypogonadism, infertility, and sexual dysfunction commonly occur if excess iron from iron overload disorders is not removed. The average male in the USA consumes significantly more iron than needed to replace daily losses. How this degree of iron loading may affect one's reproductive health remains less clear, but there is evidence it may have adverse effects.

Testicular torsion and reperfusion: evidences for biochemical and molecular alterations

This study was done in order to determine the molecular and biochemical alterations following testicular torsion (TT) and torsion-reperfusion (TR). For this purpose, 54 male Wistar rats were divided into five groups as control group (n = 6) and experimental group subjected to 1, 2, 4, and 8 h unilateral left torsion induction (n = 12 in each group). After induction of TT, testicular samples were collected from each group (n = 6), and the other six rats of each group underwent the same period of reperfusion after TT and then were sampled. Histological changes, the mRNA and protein expression of heat shock protein-70 (Hsp70), and caspase-3 were examined using reverse transcriptase-PCR (RT-PCR) and immunohistochemistry, respectively. Testicular total antioxidant capacity (TAC), glutathione peroxidase (GSH-px), and malondialdehyde (MDA) levels were evaluated. The mRNA damage and DNA fragmentation were assessed. The TT and TR significantly reduced differentiation and spermiogenesis indices (p < 0.05). The TT- and TR-induced groups exhibited a severe reduction in Hsp70 expression as well as remarkable enhancement in caspase-3 expression. The TAC and GSH-px levels were decreased and the MDA content was increased in TT- and TR-induced groups. Finally, the TT and TR enhanced mRNA damage and DNA fragmentation. The TT- and TR-induced damaging oxidative stress, diminished Hsp70 expression, and enhanced caspase-3 mRNA and protein levels result in apoptosis following 1, 2, and 4 h. Whereas, following 8 h, TT and TR initiate the necrosis by inducing energy depletion as well as severe mRNA damage.

Putative human sperm Interactome: a networks study

Background

For over sixty years, it has been known that mammalian spermatozoa immediately after ejaculation are virtually infertile. They became able to fertilize only after they reside for long time (hours to days) within female genital tract where they complete their functional maturation, the capacitation. This process is finely regulated by the interaction with the female environment and involves, in spermatozoa, a myriad of molecules as messengers and target of signals. Since, to date, a model able to represent the molecular interaction that characterize sperm physiology does not exist, we realized the Human Sperm Interactme Network3.0 (HSIN3.0) and its main component (HSNI3.0_MC), starting from the pathway active in male germ cells.

Results

HSIN3.0 and HSIN3.0_MC are scale free networks, adherent to the Barabasi-Albert model, and are characterised by an ultra-small world topology. We found that they are resistant to random attacks and that are designed to respond quickly and specifically to external inputs. In addition, it has been possible to identify the most connected nodes (the hubs) and the bottlenecks nodes. This result allowed us to explore the control mechanisms active in driving sperm biochemical machinery and to verify the different levels of controls: party vs. date hubs and hubs vs. bottlenecks, thanks the availability of data from KO mice. Finally, we found that several key nodes represent molecules specifically involved in function that are thought to be not present or not active in sperm cells, such as control of cell cycle, proteins synthesis, nuclear trafficking, and immune response, thus potentially open new perspectives on the study of sperm biology.

Conclusions

For the first time we present a network representing putative human sperm interactome. This result gives very intriguing biological information and could contribute to the knowledge of spermatozoa, either in physiological or pathological conditions.

Electronic supplementary material

The online version of this article (10.1186/s12918-018-0578-6) contains supplementary material, which is available to authorized users.

Chrysin Administration Protects against Oxidative Damage in Varicocele-Induced Adult Rats

Oxidative stress is known as the leading factor responsible for varicocele-related infertility and for that reason, many antioxidant therapies have been proposed. Considering that, we evaluated the reproductive outcomes and fertility of varicocelized rats and the impact of chrysin within these parameters. The animals were allocated into three groups: sham (control), varicocele treated via gavage with 50 mg/kg/day of chrysin (V1), or vehicle (V2) for 56 days. Chrysin treatment prevented oxidative damage resulting from varicocele by decreasing testicular concentrations of malondialdehyde and sperm DNA fragmentation. It also improved histological aspect of the testis and maintained morphometric parameters similar to the sham group. Furthermore, there were no differences in body and reproductive organ weights, histopathological analysis of epididymis, sperm counts and morphology, testosterone levels, sexual behavior, and fertility parameters among experimental groups. Our results reinforce the idea that injuries provoked by experimental varicocele are related, at least in part, to oxidative stress. Moreover, varicocele showed bilateral deleterious effects without interfering with fertility. Chrysin administration significantly ameliorated sperm parameters, protecting the reproductive system against varicocele damages. For that reason, chrysin might be an alternative adjuvant therapy to improve sperm quality in men presenting this condition.