Effects of Ferroptosis on Male Reproduction

Transcriptome analysis reveals the molecular mechanisms of neonicotinoid acetamiprid in Leydig cells

At present, the reproductive toxicology of neonicotinoids has received greater attention, however, its potential mechanisms are still not fully understood. Acetamiprid (ACE) is a new-generation neonicotinoid and has become a ubiquitous contaminant in the environment. This study aimed to investigate the toxic effects of ACE in TM3 Leydig cells based on transcriptome analysis. The viability and apoptosis of TM3 cells exposed to different concentrations of ACE were assessed by CCK8 and flow cytometry, respectively. After ACE exposure, transcriptome analysis was performed to screen differential expression genes (DEGs), followed by qPCR verification. Results showed that ACE exposure resulted in a time- and dose-dependent decrease in the viability of TM3 cells (p < .05). ACE also exerted a dose-dependent pro-apoptotic effect on TM3 cells. Results of RNA-seq showed that 1477 DEGs were obtained, of which 539 DEGs were up-regulated and 938 DEGs were down-regulated. GO and KEGG analyses of DEGs showed that DNA replication and cell cycle might be the key mechanisms for the cytotoxicity of ACE. qPCR results demonstrated that Mdm2, Cdkn1a (p21) and Gadd45 were significantly increased, and Pcna, Ccna2 (CycA), Ccnb1 (CycB), Ccne1 (CycE), and Cdk1 were significantly decreased, indicating that ACE exposure might promote G1/S and G2/M cell cycle arrest. Additionally, FoxO, p53, and HIF-1 signaling pathways and ferroptosis might play important roles in ACE-induced reproductive toxicity. Collectively, this study provides new perspectives into the mechanism of ACE-induced reproductive toxicity and lays a theoretical foundation for the in-depth study of non-target toxicity mechanisms of neonicotinoid insecticides.

The role of ferroptosis in environmental pollution-induced male reproductive system toxicity

This article provides a comprehensive review of the toxic effects of environmental pollution on the male reproductive system, with a particular emphasis on ferroptosis, a form of programmed cell death. Research has shown that environmental pollutants, such as heavy metals, pesticide residues, and plastic additives, can disrupt oxidative stress, increasing the production of reactive oxygen species (ROS) in germ cells. This disruption damages cellular lipids, proteins, and DNA, culminating in cell dysfunction or death. Ferroptosis, a cell death pathway closely linked to oxidative stress, is characterized by the accumulation of intracellular iron ions and elevated levels of lipid ROS. This review also explores the role of ferroptosis in male reproductive disorders, including its contributions to reduced sperm count, decreased motility, and abnormal morphology. Environmental pollutants, particularly heavy metals, can induce ferroptosis by interfering with intracellular antioxidant systems, notably the NRF2, GSH, and GPX4 pathways, accumulating toxic lipid peroxides. Furthermore, the article examines the potential interplay between ferroptosis and other forms of cell death, such as apoptosis, autophagy, pyroptosis, and necrosis, in the context of male reproductive health. The review underscores the critical need for further research into the link between environmental pollutants and male fertility, particularly focusing on ferroptosis. It advocates for targeted research efforts to mitigate the adverse effects of ferroptosis and protect reproductive health, emphasizing that a deeper understanding of these mechanisms could lead to innovative preventive strategies against environmental threats to fertility.

Astragalin alleviates oligoasthenospermia via promoting nuclear translocation of Nrf2 and reducing ferroptosis of testis

Oligoasthenospermia (OAS) is a global human developmental disease and the most common type of male infertility. There are currently no sufficiently effective therapeutic strategies for OAS. Wuziyanzong Pill (WZYZP) is a traditional Chinese prescription for the clinical treatment of male infertility, and its efficacy is well known in China. Therefore, due to the complexity of traditional Chinese medicine, the specific mechanism of action of WZYZP on OAS has not been elucidated. Astragalin (AG), one of the main active substances in WZYZP, has good antioxidant effect. The aim of this research is to investigate whether AG, the active substance in WZYZP, can treat OAS by promoting Nrf2 nuclear translocation and inhibiting ferroptosis. The OAS model was established by intraperitoneal injection of cyclophosphamide, and the therapeutic effects of AG and WZYZP on OAS were evaluated by detecting sperm quality, sex hormone levels and testicular pathological changes after intragastric administration of AG and WZYZP. Western blot was used to measure the expression levels of TFR1, SLC7A11, GPX4 and FTH1. The nuclear translocation of Nrf2 was detected by immunofluorescence staining and nuclear/intracellular expression of Nrf2. The results showed that AG could improve sperm quality and serum sex hormone levels in OAS rats, reduce the expression of testicular Fe2+ and TFR1, up-regulate testicular SLC7A11, GPX4 and FTH1, and inhibit testicular ferroptosis. At the same time, AG can promote the expression and nuclear translocation of Nrf2 in the testis of OAS rats. AG can alleviate OAS via promoting nuclear translocation of Nrf2 and inhibiting ferroptosis of testis.

Oxidative Stress Induces Changes in Molecular Markers Associated with Ferroptosis in Human Spermatozoa

PURPOSE

Ferroptosis is a type of iron-dependent regulated cell death characterized by increased bioavailability of redox-active iron, loss of GPX4 antioxidant capacity, and oxidation of polyunsaturated fatty acid-containing phospholipids mediated by reactive oxygen species (ROS). The aim of this study was to evaluate the effect of oxidative stress induced by arachidonic acid (AA) on ferroptotic cell death in human spermatozoa.

MATERIALS AND METHODS

Spermatozoa from normozoospermic donors were exposed to AA (5, 25, and 50 µM) for 1 hour at 37 ℃, including an untreated control. Oxidative stress was confirmed by evaluation of cytosolic and mitochondrial ROS production, viability, mitochondrial membrane potential (ΔΨm) and motility. Subsequently, molecular markers of ferroptosis including iron content, levels of GPX4, SLC7A11, ACSL4, IREB2 and lipid peroxidation were evaluated. The analyses were carried out using either flow cytometry, a microplate reader or confocal laser microscopy.

RESULTS

AA-induced oxidative stress showed increased cytosolic and mitochondrial ROS production accompanied by impairedΔΨm, viability and motility in human spermatozoa. These results were associated with biochemical and molecular markers related to ferroptotic cell death including an increase in iron content in the form of ferrous (Fe2+) ions, SLC7A11, ACSL4, IREB2, a decrease in the level of GPX4, and an increase in the level of lipid peroxidation compared to the untreated control.

CONCLUSIONS

This study revealed that AA-induced oxidative stress induces cell death with biochemical characteristics of ferroptosis in human spermatozoa, demonstrating another mechanism of alteration of sperm function induced by oxidative stress and could establish new therapeutic objectives to prevent the decrease in sperm quality mediated by oxidative stress.

Preliminary Evidence of the Possible Roles of the Ferritinophagy-Iron Uptake Axis in Canine Testicular Cancer

Iron is a key element in spermatogenesis; its metabolic pathway in the testis is strictly regulated. Alterations in iron metabolism are linked to various diseases, including cancer, and changes in iron metabolism-related proteins have been observed in multiple human, mouse and canine tumors. There is limited knowledge about iron metabolism in canine non-neoplastic and neoplastic testes. This study aimed to explore the immunohistochemical expression of molecules involved in iron uptake and storage [Transferrin Receptor 1 (TfR1), ferritin (FTH1), nuclear receptor coactivator 4 (NCOA4)] and PCNA in canine non-neoplastic and neoplastic testicular samples. Non-neoplastic testes showed moderate TfR1 expression in developing germ cells and Sertoli cells, high NCOA4 cytoplasmic immunostaining in the Sertoli cells and occasional cytoplasmic immunopositivity for FTH1 in the spermatogonia and Sertoli cells. In contrast, Leydig cell tumors (LCTs) and Diffuse Type Seminoma (DSEM) exhibited increased expression of TfR1, along with higher PCNA expression, suggesting a higher iron need for proliferation. Intratubular Type Seminoma (ITSEM) showed a higher FTH1 expression, indicating greater iron storage, while the increased NCOA4 expression in the LCTs and DSEM suggested ferritinophagy to release iron for proliferation. Sertoli cell tumors (SCTs) showed only NCOA4 expression. These preliminary findings highlight potential molecular targets for developing new anti-neoplastic treatments in canine testicular tumors.

The toxicity of superparamagnetic iron oxide nanoparticles induced on the testicular cells: In vitro study

Superparamagnetic iron oxide nanoparticles (SPIONs) have gained significant attention in biomedical research due to their potential applications. However, little is known about their impact and toxicity on testicular cells. To address this issue, we conducted an in vitro study using primary mouse testicular cells, testis fragments, and sperm to investigate the cytotoxic effects of sodium citrate-coated SPIONs (Cit_SPIONs). Herein, we synthesized and physiochemically characterized the Cit_SPIONs and observed that the sodium citrate diminished the size and improved the stability of nanoparticles in solution during the experimental time. The sodium citrate (measured by thermogravimetry) was biocompatible with testicular cells at the used concentration (3%). Despite these favorable physicochemical properties, the in vitro experiments demonstrated the cytotoxicity of Cit_SPIONs, particularly towards testicular somatic cells and sperm cells. Transmission electron microscopy analysis confirmed that Leydig cells preferentially internalized Cit_SPIONs in the organotypic culture system, which resulted in alterations in their cytoplasmic size. Additionally, we found that Cit_SPIONs exposure had detrimental effects on various parameters of sperm cells, including motility, viability, DNA integrity, mitochondrial activity, lipid peroxidation (LPO), and ROS production. Our findings suggest that testicular somatic cells and sperm cells are highly sensitive and vulnerable to Cit_SPIONs and induced oxidative stress. This study emphasizes the potential toxicity of SPIONs, indicating significant threats to the male reproductive system. Our findings highlight the need for detailed development of iron oxide nanoparticles to enhance reproductive nanosafety.

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.

Excessive fluoride induces ovarian function impairment by regulating levels of ferroptosis in fluorosis women and ovarian granulosa cells

The aim of this study was to investigate the role of ferroptosis in fluorosis women and the in vitro molecular mechanisms leading to ovarian dysfunction and abnormal hormone secretion by sodium fluoride (NaF) treatment of KGN cells. Fifty women with fluorosis as Fluorosis group and fifty healthy women as Control group were included in this study. The levels of lipid peroxidation and activities of antioxidant enzyme were assessed by photometric methods. The content of iron and glutathione (GSH) in serum was measured by microplate method. KGN cells were treated by different concentration of NaF (0, 1, 2, 4 and 8 ×10-3 M) for 24 h. The mRNA and protein expression levels of ferroptosis-related molecules, including glutathione peroxidase 4 (GPX4), solute carrier family 7 member (SLC7A11), nuclear factor erythroid 2-related factor 2 (Nrf2), ferritin heavy chain 1 (FTH1) and p53, were assessed by qRT-PCR and western blot analysis. Fluorosis group women had a significant higher levels of iron, Malondialdehyde (MDA), FSH and LH, and a lower levels of E2 and antioxidant enzyme in serum than that in the control group. The representative molecular changes of ferroptosis, such as the decrease in GPX4, Nrf2 and SLC7A11 expression (mRNA and protein expression), the increase in protein expression of p53, and a reduced level of E2 were observed in KGN cells treated by excessive NaF.It is concluded therefore that NaF increases the expression of p53 and inhibits ovarian granulosa cell ferroptosis preventive protein expression, resulting in abnormal hormone secretion and the ovarian dysfunction.

Targeting autophagy drug discovery: Targets, indications and development trends

Autophagy plays a vital role in sustaining cellular homeostasis and its alterations have been implicated in the etiology of many diseases. Drugs development targeting autophagy began decades ago and hundreds of agents were developed, some of which are licensed for the clinical usage. However, no existing intervention specifically aimed at modulating autophagy is available. The obstacles that prevent drug developments come from the complexity of the actual impact of autophagy regulators in disease scenarios. With the development and application of new technologies, several promising categories of compounds for autophagy-based therapy have emerged in recent years. In this paper, the autophagy-targeted drugs based on their targets at various hierarchical sites of the autophagic signaling network, e.g., the upstream and downstream of the autophagosome and the autophagic components with enzyme activities are reviewed and analyzed respectively, with special attention paid to those at preclinical or clinical trials. The drugs tailored to specific autophagy alone and combination with drugs/adjuvant therapies widely used in clinical for various diseases treatments are also emphasized. The emerging drug design and development targeting selective autophagy receptors (SARs) and their related proteins, which would be expected to arrest or reverse the progression of disease in various cancers, inflammation, neurodegeneration, and metabolic disorders, are critically reviewed. And the challenges and perspective in clinically developing autophagy-targeted drugs and possible combinations with other medicine are considered in the review.

Di-(2-ethylhexyl) phthalate induces ferroptosis in prepubertal mouse testes via the lipid metabolism pathway

Di-(2-ethylhexyl) phthalate (DEHP), a widely used plasticizer, has been shown to cause reproductive toxicity, but the precise mechanism remains unclear. This study aimed to investigate the possible molecular mechanism of DEHP-induced testicular damage. In vivo study, we administered different doses of DEHP (0, 250, and 500 mg/kg/day) to male C57BL/6 mice from 22 and 35 days after birth. We found that DEHP exposure induced histopathological alterations in prepubertal testes, and testicular lipidomics indicated notable alterations in lipid metabolism and significant enrichment of ferroptosis. Further tests showed that ferrous iron (Fe2+ ) and malondialdehyde (MDA) levels significantly increased after DEHP exposure. Western blotting revealed that DEHP exposure reduced glutathione peroxidase 4 (GPX4) expression, and elevated acyl coenzyme A synthetase long-chain member 4 (ACSL4) and lysophosphatidylcholine acyltransferase 3 (LPCAT3) expression. The in vitro results were consistent with the in vivo results. When Leydig cells and Sertoli cells were treated with ferrostatin-1 and monoethylhexyl phthalate (MEHP), MEHP-induced increases in Fe2+ and MDA levels, accumulation of lipid reactive oxygen species, downregulation of GPX4, and upregulation of ACSL4 and LPCAT3 were reversed. Collectively, our findings suggested that aberrant lipid metabolism and ferroptosis may be involved in prepubertal DEHP exposure-induced testicular damage.

Ferritinophagy-mediated ferroptosis of spermatogonia is involved in busulfan-induced oligospermia in the mice

Busulfan, a bifunctional alkylated chemotherapeutic agent, has male reproductive toxicity and induce oligospermia, which is associated with ferroptosis. However, the specific target cells of busulfan-induced oligospermia triggered by ferroptosis are largely elusive, and the detailed mechanisms also require further exploration. In the present study, busulfan (0.6, and 1.2 mM, 48 h) causes ferroptosis in GC-1 spg cells through inducing Fe2+, ROS and MDA accumulation and functional inhibition of Xc-GSH-GPX4 antioxidant system. After inhibition of ferroptosis by Fer-1 (1 μM, pretreatment for 2 h) or DFO (10 μM, pretreatment for 2 h) reverses busulfan-induced destructive effects in GC-1 spg cells. Furthermore, using RNA-seq and Western blotting, we found that busulfan promotes autophagy-dependent ferritin degradation, as reflected by enriching in autophagy, increased LC3 II, Beclin1 and NCOA4, as well as decreased P62 and ferritin heavy chain 1 (FTH1). Ultimately, GC-1 spg cells and Balb/c mice were treated with busulfan and/or 3-MA, the inhibitor of autophagy. The results displayed that inhibition of autophagy relieves busulfan-induced FTH1 degradation and then blocks the occurrence of ferroptosis in GC-1 spg cells and testicular spermatogonia, which subsequently alleviates busulfan-caused testicular damage and spermatogenesis disorders. In summary, these data collectively indicated that ferroptosis of spermatogonia is involved in busulfan-induced oligospermia and mediated by autophagy-dependent FTH1 degradation, identifying a new target for the therapy of busulfan-induced male infertility.

T-2 toxin-induced testicular impairment by triggering oxidative stress and ferroptosis

T-2 toxin is a trichothecene mycotoxin of significant danger to humans and animals. Its impact on reproductive toxicity is attributed to oxidative stress, which ultimately leads to cell death. Ferroptosis is a programmed cell death that characterized by lipid peroxidation. This study aimed to investigate the toxic effects of T-2 toxin on mouse testis and the potential mechanism of T-2 toxin-induced ferroptosis. T-2 toxin significantly altered the morphology of the testis and decreased testosterone level, sperm concentration, and increased sperm malformation rate, as well as induced oxidative damage with reactive oxygen species and malondialdehyde accumulated, and activity of superoxide dismutase, glutathione peroxidase decreased. Additionally, T-2 toxin induced ferroptosis by accumulating iron ions, increasing prostaglandin endoperoxide synthase 2, downregulating glutathione peroxidase 4 and ferritin heavy chain 1, as well as manifesting ferroptotic morphological alterations, ultimately leading to testicular impairment. Administration of ferroptosis inhibitor liproxstatin-1 or antioxidant resveratrol effectively mitigated the T-2 toxin-induced ferroptosis and testicular injury. These findings provided novel insights into the fundamental mechanism of T-2 toxin-induced cell death and furnished further proof of the potential therapeutic effect in addressing T-2 toxin-induced testicular impairment.

Synergistic effect of PS-MPs and Cd on male reproductive toxicity: Ferroptosis via Keap1-Nrf2 pathway

It has been wildly reported that microplastics (MPs) can adsorb heavy metals and act as carriers for their transport into organisms. However, the combined toxicity of MPs and heavy metals remains poorly studied. In this study, we established single or co-exposure (i.e. complex/combined exposure) mice models to investigate the combined toxicity of MPs and cadmium (Cd) on male reproduction. The complexation of MPs and Cd enhanced the bioavailability of Cd, while the combination of MPs and Cd exerted synergistic effect. Ultimately, the co-exposure was reported to enhance the reproduction toxicity by single exposure, which reflected in testicular structure, spermatogenesis and sex hormone synthesis. More in-depth mechanistic investigation suggested that MPs and Cd synergistically inhibited the Keap1-Nrf2 pathway and its downstream genes, induced lipid peroxidation and ferroptosis, ultimately caused damage to reproductive structures and functions. Our results highlighted the synergistic effect of MPs and Cd on the reproductive toxicity in male mammals for the first time, which also provided valuable insights into the combined toxicity mechanisms of MPs and other pollutants.

Gss deficiency causes age-related fertility impairment via ROS-triggered ferroptosis in the testes of mice

Glutathione synthetase (GSS) catalyzes the final step in the synthesis of glutathione (GSH), a well-established antioxidant. Research on the specific roles of the Gss gene during spermatogenesis remains limited due to the intricate structure of testis. In this study, we identified pachytene spermatocytes as the primary site of GSS expression and generated a mouse model with postnatal deletion of Gss using Stra8-Cre (S8) to investigate the role of GSS in germ cells. The impact of Gss knockout on reducing male fertility is age-dependent and caused by ferroptosis in the testis. The 2-month-old S8/Gss-/- male mice exhibited normal fertility, due to a compensatory increase in GPX4, which prevented the accumulation of ROS. With aging, there was a decline in GPX4 and an increase in ALOX15 levels observed in 8-month-old S8/Gss-/- mice, resulting in the accumulation of ROS, lipid peroxidation, and ultimately testicular ferroptosis. We found that testicular ferroptosis did not affect spermatogonia, but caused meiosis disruption and acrosome heterotopia. Then the resulting aberrant sperm showed lower concentration and abnormal morphology, leading to reduced fertility. Furthermore, these injuries could be functionally rescued by inhibiting ferroptosis through intraperitoneal injection of GSH or Fer-1. In summary, Gss in germ cells play a crucial role in the resistance to oxidative stress injury in aged mice. Our findings deepen the understanding of ferroptosis during spermatogenesis and suggest that inhibiting ferroptosis may be a potential strategy for the treatment of male infertility.

PS-MPs or their co-exposure with cadmium impair male reproductive function through the miR-199a-5p/HIF-1α-mediated ferroptosis pathway

Microplastics (MPs) and cadmium (Cd) exist extensively in ambient environments and probably influence negatively on human health. However, the potential reproductive toxicity of MPs or MPs + Cd remains unknown. This study was aimed to observe the reproductive changes of male mice treated orally for 35 days with PS-MPs (100 mg/kg), CdCl2 (5 mg/kg) and PS-MPs plus CdCl2 mixture. We found that subchronic exposure to PS-MPs damaged mouse testicular tissue structure, reduced sperm quality and testosterone levels. Moreover, the reproductive toxicity in 0.1 μm group was stronger than 1 μm group, and mixture group was more severe than single particle size ones. Meanwhile, co-exposure of PS-MPs and Cd exacerbated reproductive injury in male mice, with an ascending toxicity of Cd, 1 μm + Cd, 0.1 μm + Cd, and 0.1+1 μm + Cd. In addition, we discovered that the testicular damage induced by PS-MPs or PS-MPs + Cd was associated with interfering the miR-199a-5p/HIF-1α/ferroptosis pathway. Promisingly, these findings will shed new light on how PS-MPs and PS-MPs + Cd damage male reproductive function.

Emerging roles of ferroptosis in male reproductive diseases

Ferroptosis is a type of programmed cell death mediated by iron-dependent lipid peroxidation that leads to excessive lipid peroxidation in different cells. Ferroptosis is distinct from other forms of cell death and is associated with various diseases. Iron is essential for spermatogenesis and male reproductive function. Therefore, it is not surprising that new evidence supports the role of ferroptosis in testicular injury. Although the molecular mechanism by which ferroptosis induces disease is unknown, several genes and pathways associated with ferroptosis have been linked to testicular dysfunction. In this review, we discuss iron metabolism, ferroptosis, and related regulatory pathways. In addition, we analyze the endogenous and exogenous factors of ferroptosis in terms of iron metabolism and testicular dysfunction, as well as summarize the relationship between ferroptosis and male reproductive dysfunction. Finally, we discuss potential strategies to target ferroptosis for treating male reproductive diseases and provide new directions for preventing male reproductive diseases.

Cadmium exposure during puberty damages testicular development and spermatogenesis via ferroptosis caused by intracellular iron overload and oxidative stress in mice

Cadmium (Cd) is a widespread environmental pollutant and a reproductive toxicant. It has been proved that Cd can reduce male fertility, however, the molecular mechanisms remain unveiled. This study aims to explore the effects and mechanisms of pubertal Cd exposure on testicular development and spermatogenesis. The results showed that Cd exposure during puberty could cause pathological damage to testes and reduce sperm counts in mice in adulthood. Moreover, Cd exposure during puberty reduced GSH content, induced iron overload and ROS production in testes, suggesting that Cd exposure during puberty may induce testicular ferroptosis. The results in vitro experiments further strengthened that Cd caused iron overload and oxidative stress, and decreased MMP in GC-1 spg cells. In addition, Cd disturbed intracellular iron homeostasis and peroxidation signal pathway based on transcriptomics analysis. Interestingly, these changes induced by Cd could be partially suppressed by pretreated with ferroptotic inhibitors, Ferrostatin-1 and Deferoxamine mesylate. In conclusion, the study demonstrated that Cd exposure during puberty maybe disrupted intracellular iron metabolism and peroxidation signal pathway, triggered ferroptosis in spermatogonia, and ultimately damaged testicular development and spermatogenesis in mice in adulthood.

FTO-Nrf2 axis regulates bisphenol F-induced leydig cell toxicity in an m6A-YTHDF2-dependent manner

Studies have shown that Bisphenol F (BPF) as an emerging bisphenol pollutant also has caused many hazards to the reproductive systems of humans and animals. However, its specific mechanism is still unclear. The mouse TM3 Leydig cell was used to explore the mechanism of BPF-induced reproductive toxicity in this study. The results showed BPF (0, 20, 40 and 80 μM) exposure for 72 h significantly increased cell apoptosis and decreased cell viability. Correspondingly, BPF increased the expression of P53 and BAX, and decreased the expression of BCL2. Moreover, BPF significantly increased the intracellular ROS level in TM3 cells, and significantly decreased oxidative stress-related molecule Nrf2. BPF decreased the expression of FTO and YTHDF2, and increased the total cellular m6A level. ChIP results showed that AhR transcriptionally regulated FTO. Differential expression of FTO revealed that FTO reduced the apoptosis rate of BPF-exposed TM3 cells and increased the expression of Nrf2, MeRIP confirmed that overexpression of FTO reduced the m6A of Nrf2 mRNA. After differential expression of YTHDF2, it was found that YTHDF2 enhanced the stability of Nrf2, and RIP assay showed that YTHDF2 was bound to Nrf2 mRNA. Nrf2 agonist enhanced the protective effect of FTO on TM3 cells exposure to BPF. Our study is the first to demonstrate that AhR transcriptionally regulated FTO, and then FTO regulated Nrf2 in a m6A-modified manner through YTHDF2, thereby affecting apoptosis in BPF-exposed TM3 cells to induce reproductive damage. It provides new insights into the importance of FTO-YTHDF2-Nrf2 signaling axis in BPF-induced reproductive toxicity and provided a new idea for the prevention of male reproductive injury.

Integration of metabolomics and transcriptomics to reveal ferroptosis is involved in Tripterygium wilfordii polyglycoside tablet-induced testicular injury

ETHNOPHARMACOLOGICAL RELEVANCE

Tripterygium wilfordii polyglycoside tablet (TWP), a traditional Chinese medicine preparation, has multiple pharmacological properties, including anti-inflammatory, immune-modulatory and anti-proliferative activities. However, the reproductive toxicity of TWP greatly limits its clinical application and the mechanism of TWP-induced reproductive toxicity is not fully understood yet.

AIM OF THE STUDY

This study was designed to explore the mechanism of TWP-induced testis injury in male rats.

MATERIALS AND METHODS

The mechanism underlying TWP-induced rat testicular injury was firstly investigated by integration of metabolomics and transcriptomics. Meanwhile, histopathological analysis, Western blot and RT-qPCR were performed to confirm the damaging effects and mechanisms of TWP on rat testis.

RESULTS

Histopathological analysis revealed that TWP had significant testicular damage, which severely reduced the testis's tubular diameter and epithelium height. Further, TWP caused the protein level of ZO-1, CLDN11, PLZF, and OCT4 significantly downregulate, suggesting the blood-testis barrier function and spermatogenesis were damaged. Differentially expressed genes (DEGs), including 4952 upregulated and 2626 downregulated, were found in TWP-exposed testis compared to the normal group. Moreover, 77 changed metabolites were identified from testis samples. With integrated analysis of DEGs and changed metabolites, we found that glutathione metabolism and ferroptosis played an essential role in testicular injury. Additionally, the levels of ferroptosis-related protein GPX4, SLC7A11, and NRF2 were significantly downregulated, and the protein level of 4-HNE, a leading product of lipid peroxidation and oxidative stress, was upregulated. The changes in ferroptosis-related genes indicated that TWP might promote ferroptosis in rat testis.

CONCLUSION

These results suggested that ferroptosis was involved in the testicular damage caused by TWP, which might provide a new strategy to alleviate TWP- induced testicular injury.

Bioinorganic Modulators of Ferroptosis: A Review of Recent Findings

Ferroptosis was first reported as a separate modality of regulated cell death in 2008 and distinguished under its current name in 2012 after it was first induced with erastin. In the following decade, multiple other chemical agents were researched for their pro- or anti-ferroptotic properties. Complex organic structures with numerous aromatic moieties make up the majority of this list. This review fills a more overlooked niche by gathering, outlining and setting out conclusions regarding less prominent cases of ferroptosis induced by bioinorganic compounds and reported on within the last few years. The article contains a short summary of the application of bioinorganic chemicals based on gallium, several chalcogens, transition metals and elements known as human toxicants used for the purpose of evoking ferroptotic cell death in vitro or in vivo. These are used in the form of free ions, salts, chelates, gaseous and solid oxides or nanoparticles. Knowledge of how exactly these modulators promote or inhibit ferroptosis could be beneficial in the context of future therapies aimed against cancer or neurodegenerative diseases, respectively.

The effect of alpha-lipoic acid on sperm functions in rodent models for male infertility: A systematic review

In this systematic review, we assessed different studies to evaluate the protective effect of alpha-lipoic acid (ALA), as a multifaceted antioxidant, on sperm functions in rodent models. Four databases were searched to find papers reporting the effect of ALA treatment on animal models of male infertility. Up to December 2022, 11,787 articles were identified to explain the ALA protective effects. The included studies were evaluated for eligibility and risk of bias (CRD42022341370). Finally, we identified 23 studies that explain the effect of ALA on sperm functions in rodents. Among them, 15 studies indicated that ALA could restore sperm parameters. Six studies showed a significant reduction in sperm DNA damage by ALA treatment. Seventeen papers displayed the ALA antioxidant ability, and four studies indicated the ALA anti-inflammatory effect. Besides, thirteen studies displayed that ALA could modulate androgenesis. Also, eighteen studies revealed that ALA restored the testicular architecture to normal, and was also effective in restoring reproductive performance in two included studies. This systematic review provided cogent evidence for the protective effect of ALA in rodent models for male infertility by re-establishing spermatogenesis and steroidogenesis and maintaining redox and immune systems homeostasis.

The initiator of neuroexcitotoxicity and ferroptosis in ischemic stroke: Glutamate accumulation

Glutamate plays an important role in excitotoxicity and ferroptosis. Excitotoxicity occurs through over-stimulation of glutamate receptors, specifically NMDAR, while in the non-receptor-mediated pathway, high glutamate concentrations reduce cystine uptake by inhibiting the System Xc-, leading to intracellular glutathione depletion and resulting in ROS accumulation, which contributes to increased lipid peroxidation, mitochondrial damage, and ultimately ferroptosis. Oxidative stress appears to crosstalk between excitotoxicity and ferroptosis, and it is essential to maintain glutamate homeostasis and inhibit oxidative stress responses in vivo. As researchers work to develop natural compounds to further investigate the complex mechanisms and regulatory functions of ferroptosis and excitotoxicity, new avenues will be available for the effective treatment of ischaemic stroke. Therefore, this paper provides a review of the molecular mechanisms and treatment of glutamate-mediated excitotoxicity and ferroptosis.

Review of the Role of Ferroptosis in Testicular Function

Iron is an important metal element involved in the regulation of male reproductive functions and has dual effects on testicular tissue. A moderate iron content is necessary to maintain testosterone synthesis and spermatogenesis. Iron overload can lead to male reproductive dysfunction by triggering testicular oxidative stress, lipid peroxidation, and even testicular ferroptosis. Ferroptosis is an iron-dependent form of cell death that is characterized by iron overload, lipid peroxidation, mitochondrial damage, and glutathione peroxidase depletion. This review summarizes the regulatory mechanism of ferroptosis and the research progress on testicular ferroptosis caused by endogenous and exogenous toxicants. The purpose of the present review is to provide a theoretical basis for the relationship between ferroptosis and male reproductive function. Some toxic substances or danger signals can cause male reproductive dysfunction by inducing testicular ferroptosis. It is crucial to deeply explore the testicular ferroptosis mechanism, which will help further elucidate the molecular mechanism of male reproductive dysfunction. It is worth noting that ferroptosis does not exist alone but rather coexists with other forms of cell death (such as apoptosis, necrosis, and autophagic death). Alleviating ferroptosis alone may not completely reverse male reproductive dysfunction caused by various risk factors.