Di-(2-ethylhexyl) phthalate exposure leads to ferroptosis via the HIF-1α/HO-1 signaling pathway in mouse testes

Unraveling the crucial role of SDF-1 in osteoarthritis progression: IL6/HIF-1α positive feedback and chondrocyte ferroptosis

BACKGROUND

Osteoarthritis (OA) is a common joint disease with an incompletely understood pathogenesis. SDF-1, a key factor in cartilage matrix degradation, is involved in OA cartilage degeneration, yet its mechanism, especially regarding ferroptosis, remains unclear. This study focuses on elucidating the role of SDF-1-induced chondrocyte ferroptosis and the IL6/HIF-1α signalling axis in OA.

METHODS

A rabbit OA model was created via SDF-1 induction. Knee cartilage tissues were sequenced and analyzed bioinformatically to identify key genes, and explore critical pathways. Clinical tissue samples were utilized to validate their clinical relevance. Furthermore, cell and rabbit models were constructed through gene interference and pathway blocking. The expression of related genes and proteins was detected by QPCR, ELISA, Western blot, and immunofluorescence. Additionally, OA and ferroptosis indicators such as cell viability, immunohistochemistry, ROS, lipid ROS, Fe2+, MDA, and mitochondrial morphology were evaluated to uncover the molecular mechanism by which SDF-1 regulates the IL6/HIF-1α signalling axis to mediate chondrocyte ferroptosis.

RESULTS

Bioinformatics revealed that ferroptosis was significantly activated in SDF-1-induced OA, with IL6 and HIF-1 pathways implicated. In vitro and in vivo, SDF-1 increased the expression and secretion of MMP13 but decreased COL2A1 and ACAN in chondrocytes, leading to OA-like changes. It also suppressed the expression levels of SLC7A11 and GPX4, upregulated the gene and protein levels of ACSL4, promoted the accumulation of MDA, Fe2+, and ROS, and caused mitochondrial morphological changes. These ferroptosis manifestations could be alleviated by the ferroptosis inhibitor Fer-1. IL6 was an important mediator of SDF-1-induced ferroptosis, and knocking down IL6 also inhibited chondrocyte ferroptosis changes. Overexpressing IL6 (oeIL6) and using PX478 to inhibit the HIF-1 signalling pathway showed that PX478 could significantly relieve the cytotoxicity produced by the culture of oeIL6 and SDF-1, enhance chondrocyte viability, reverse the decreased expression of SLC7A11 and GPX4 caused by oeIL6, increase the expression of ACSL4, reverse the accumulation of MDA, Fe2+, and ROS. Moreover, PX478 could also significantly reduce the expression and secretion of IL6.

CONCLUSION

SDF-1 mediates chondrocyte ferroptosis via the IL6/HIF-1α positive feedback, promoting OA.

Prepubertal Exposure to Tris(2-chloroethyl) Phosphate Disrupts Blood-Testis Barrier Integrity via Ferritinophagy-Mediated Ferroptosis

Tris(2-chloroethyl) phosphate (TCEP) is a representative chlorinated organophosphate flame retardant (OPFR) that demonstrates greater persistence than other non-halogenated alkyl or aryl OPFRs. Although TCEP has been shown to accumulate significantly in the environment and contribute to testicular toxicity and spermatogenic dysfunction, the precise underlying factors and mechanisms of action remain unclear. Herein, male ICR mice were gavaged with corn oil, 50 mg/kg body weight (bw) TCEP, or 100 mg/kg bw TCEP from postnatal day (PND) 22 to PND 35. TCEP exposure resulted in the disruption of blood-testis barrier (BTB) integrity and in abnormal testicular development. Considering that Sertoli cells constitute the primary target of toxicants and that TCEP induces oxidative stress in the testis and other organs, we focused on ferroptosis in Sertoli cells. Our findings revealed a significant increase in ferroptosis in the testes and Sertoli cells following TCEP exposure, and we observed functional restoration of Sertoli cell junctions upon treatment with the ferroptosis inhibitor ferrostatin-1. Furthermore, ferritin heavy chain 1 (FTH1) was markedly reduced in TCEP-exposed testes and Sertoli cells. Since nuclear receptor coactivator 4 (NCOA4)-mediated ferritinophagy is essential for the degradation of FTH1, we assessed ferritinophagic activity and found significant upregulation of NCOA4, ATG5, ATG7, and LC3B II/I in TCEP-exposed testes and Sertoli cells. These results strongly suggest that TCEP triggers Sertoli cell ferroptosis by activating ferritinophagy that leads to reduced expression of BTB-associated proteins, ultimately causing BTB disruption and testicular developmental toxicity.

Do emerging alternatives pose similar soil ecological risks as traditional plasticizers? A multi-faceted analysis using earthworms as a case study

The extensive application of plasticizers has led to significant environmental issues. This study focused on the ecotoxic effects on earthworms of the traditional plasticizer di(2-ethylhexyl) phthalate (DEHP) and non-phthalate plasticizers di(ethylhexyl) terephthalate (DEHT) and acetyltributyl citrate (ATBC). At an environmentally relevant concentration (50 mg/kg), significant accumulation of ROS was observed in earthworms, with a trend of DEHP > DEHT > ATBC, inducing oxidative stress and lipid peroxidation. DEHP, DEHT, and ATBC impaired the energy metabolism in earthworms, as evidenced by a sharp reduction in ATP content ranging from 43.2 % to 75.8 %, which was attributed to the disruption of glycolysis and the TCA cycle. Concurrently, the numbers of cocoons and juvenile earthworms decreased by 23.3 %-76.7 % and 24.2 %-75.8 %, respectively, indicating a significant decline in reproductive capacity. Using qPCR, AlphaFold2, and molecular docking techniques, this study is the first to report that because of their similar molecular structures, the alternatives to DEHP exhibit estrogen-like effects in earthworms, which may be a key mechanism of reproductive toxicity. These results provide valuable references and profound insights for the development of novel plasticizer alternatives and the assessment of their impact on soil ecosystems.

Transformable Tumor Microenvironment-Responsive Oxygen Vacancy-Rich MnO2@Hydroxyapatite Nanospheres for Highly Efficient Cancer Sonodynamic Immunotherapy

Despite the promise of sonodynamic therapy (SDT)-mediated immunotherapy, the anticancer efficacy of current sonosensitizers is greatly limited by the immunosuppressive tumor microenvironment (TME) and their inability to selectively respond to it. Herein, oxygen vacancy-rich MnO2@hydroxyapatite (Ca10(PO4)6(OH)2) core-shell nanospheres (denoted as Ov-MO@CPO) as an advanced TME-responsive sonosensitizer for sonodynamic immunotherapy is demonstrated. The Ov-MO@CPO maintains its structural integrity under neutral conditions but dissolves the pH-sensitive hydroxyapatite shell under acidic TME to release active oxygen vacancy-rich MnO2 core, which reinvigorates H2O2 consumption and hypoxia alleviation due to its catalase-like activity. Furthermore, the introduced oxygen vacancies optimize the electronic structure of Ov-MO@CPO, with active electronic states near the Fermi level and higher d-band center. It results in accelerated electron-hole pair separation and lower catalytic energy barriers to boost ultrasound (US)-initiated ROS production. These multimodal synergistic effects effectively reverse the immunosuppressive tumor microenvironment, inhibiting tumor growth and metastasis in 4T1 tumor-bearing mice. No evident toxic effects are observed in normal mouse tissues. Additionally, when combined with an immune checkpoint inhibitor, Ov-MO@CPO-mediated SDT further improves the effectiveness of immunotherapy. This work affords a new avenue for developing TME-dependent sonosensitizers for SDT-mediated immunotherapy.

Fine Particulate Matter (PM2.5) and the Blood-Testis Barrier: An in Vivo and in Vitro Mechanistic Study

BACKGROUND

Fine particulate matter [particulate matter (PM) with aerodynamic diameter of ≤ 2.5 μ m (PM 2.5 )] is considered a major component of ambient PM. Exposure to PM 2.5 was shown to be associated with male reproductive system injury. Ferroptosis is regarded as an iron-dependent programmed cell death that is associated with the pathological process. It has been reported that SIRT1 has protective effects on the male reproductive system. However, the underlying mechanisms of exposure to PM 2.5 -induced testicular injury are still unexplored.

OBJECTIVES

In this study, we investigated the relationship between ferroptosis and male reproductive injury after exposure to PM 2.5 and the role of SIRT1/HIF-1 α signaling pathway in this process.

METHODS

We established a PM 2.5 exposure model in vivo and in vitro using Sertoli cell Sirt1 conditional knockout C57BL/6 (cKO) mice testes and primary Sertoli cells. Hematoxylin and eosin (H&E) staining were conducted to examine the histology of the mice testes. Sperm parameters and biotin tracer assay were conducted to evaluate the effects of exposure to PM 2.5 on the mice testes. Related markers and genes related to the blood-testis barrier (BTB) and ferroptosis were measured by quantitative real-time polymerase chain reaction (qPCR), western blot, and immunofluorescence assay. siRNA transfection was used to evaluate the potential mechanism.

RESULTS

Significant pathological damage and lower sperm quality were detected in mice testes exposed to PM 2.5 . We found that exposure to PM 2.5 damaged the BTB and inhibited the expression level of the BTB-related proteins (including Connexin 43, Occludin, Claudin 11, N-Cadherin and ZO-1). According to the enrichment analysis results, ferroptosis and HIF-1 α signaling pathway were significantly enriched in mice testes and primary Sertoli cells exposed to PM 2.5 . Subsequent experiments were conducted to verify the results of the enrichment analysis and revealed differences in the expression levels of HIF-1 α , ferroptosis-related genes (including GPX4, SLC7A11, ACSL4, and HO-1) and ferroptosis-related markers [including malondialdehyde (MDA), glutathione (GSH), and Fe 2 + ], associated with lower expression of SIRT1 after exposure to PM 2.5 . These results suggest that PM 2.5 exposure may be associated with ferroptosis and HIF-1 α signaling pathway in male reproductive dysfunction.

CONCLUSIONS

Taken together, in vivo and in vitro experiments verified that PM 2.5 exposure in mice may lead to testicular dysfunction through new pathways. https://doi.org/10.1289/EHP14447.

Gestational and lactational exposure to DEHP triggers ACSL4/TFR-mediated hippocampal neuronal ferroptosis via YAP activation: Implication for the neurocognitive disorders in male offspring

Di-(2-ethylhexyl) phthalate (DEHP) is one of the most extensively used phthalate and poses a public health concern. Perinatal exposure to DEHP has been shown to cause neurodevelopmental abnormalities and neurobehavioral disorders in offspring. However, the precise molecular mechanism has not yet been fully elucidated. In this study, pregnant C57BL/6 mice were exposed to DEHP from gestation to weaning. By RNA sequencing and animal experiments, ferroptosis has been identified as the key pathologic process contributing to DEHP-induced hippocampal injury in adult male offspring. In vitro results also showed that Ferrostatin-1 (Fer-1) effectively ameliorated Mono-(2-ethylhexyl) phthalate (MEHP) -induced cell survival via the inhibiting ferroptosis in HT22 cells. Consistently, we found that the expression of ACSL4 and TFR was significantly up-regulated in offspring hippocampi and MEHP-exposed HT22 neurons. However, silencing ACSL4 or knockdown TFR relieved MEHP-induced generation of lipid ROS and cellular iron accumulation, thereby blocking ferroptosis. Mechanistically, ACSL4/TFR-mediated ferroptosis seemed to be a Yes-associated protein (YAP) dependent via TEA domain transcription factor 4 in HT22 neurons. Importantly, treatment with Fer-1, rosiglitazone, and Deferoxamine effectively rescued DEHP-evoked cognitive decline in adult male offspring. Our findings certified that gestational and lactational exposure to DEHP provoked ACSL4/TFR-mediated hippocampal neuronal ferroptosis via YAP activation.

Green tea polyphenols alleviate di (2-ethylhexyl) phthalate-induced testicular injury in mice via lncRNA-miRNA-mRNA axis†

Di(2-ethylhexyl) phthalate (DEHP) is a commonly used plasticizer known for its toxic effects on the male reproductive system. Green tea polyphenols (GTPs), recognized for their antioxidant and anti-inflammatory properties, have demonstrated protective effects on various organs, but the mechanisms by which GTPs mitigate DEHP-induced testicular damage remain unclear. Healthy male C57BL/6J mice were divided into five groups: control, DEHP, DEHP + GTP treatment, GTP, and oil groups. Testicular histopathological changes were assessed using hematoxylin-eosin (H&E), periodic acid-Schiff (PAS), and Masson staining. Ultrastructural alterations were examined through transmission electron microscopy. High-throughput sequencing was performed to analyze the expression of mRNA, miRNA, and lncRNA and construct an lncRNA-miRNA-mRNA regulatory network for identifying key regulatory axes. Mice in the DEHP group exhibited significant testicular damage, including reduced sperm count, mitochondrial deformation, and endoplasmic reticulum dilation. GTP treatment notably improved testicular structural integrity, restored sperm count, and alleviated mitochondrial and endoplasmic reticulum damage. Additionally, DEHP significantly increased activated CD8+ T cells, which were reduced with GTP treatment. High-throughput sequencing revealed that GTP treatment exerted protective effects through the regulation of six key lncRNA-miRNA-mRNA axes. GTPs significantly protect against DEHP-induced testicular damage, and the lncRNA-miRNA-mRNA regulatory axes play a potential role in this process.

Mechanisms and targeted prevention of hepatic osteodystrophy caused by a low concentration of di-(2-ethylhexyl)-phthalate

Objectives

Hepatic osteodystrophy (HOD) is an important public health issue that severely affects human health. The pathogenesis of HOD is complex, and exposure to environmental pollutants plays an important role. Di-(2-ethylhexyl) phthalate (DEHP) is a persistent environmental endocrine toxicant that is present in many products, and the liver is an important target organ for its toxic effects. Our research aimed to investigate the effects of DEHP on HOD, and to reveal the underlying mechanisms and the potential key preventive approaches.

Methods

The daily intake EDI of DEHP and bone density indicators for men and women from 2009 to 2018 were screened and organized from the NHANES database to reveal the population correlation between EDI and BMD; C57BL/6 female and male mice were selected to construct an animal model of DEHP induced HOD, exploring the fuchtions and mechanisms of DEHP on osteoporosis; the novel small molecule inhibitor imICA was used to inhibit the process of DEHP induced osteoporosis, further exploring the targeted inhibition pathway of DEHP induced HOD.

Results

Male and female populations were exposed to a relatively lower concentration of DEHP, and that only the male population exhibited a negative correlation between DEHP exposure and bone mineral density. An in vivo study confirmed that a low dose of DEHP caused liver lesions, disrupted liver function, and induced osteoporosis in male but not female C57BL/6J mice. Regarding the molecular mechanisms, a low dose of DEHP activated the hepatic 14-3-3η/nuclear factor κB (NF-κB) positive feedback loop, which in turn modified the secretory proteome associated with bone differentiation, leading to HOD. Finally, we revealed that targeting the 14-3-3η/ NF-κB feedback loop using our novel 14-3-3η inhibitor (imICA) could prevent DEHP-induced HOD.

Conclusion

A low dose of DEHP activated the hepatic 14-3-3η/ NF-κB positive feedback loop, which in turn modified the secretory proteome associated with bone differentiation and elevated IL-6 and CXCL1 levels, leading to HOD. Targeted 14-3-3η/NF-κB feedback loop using our novel 14-3-3η inhibitor, imICA, prevented DEHP-induced HOD.

Circadian rhythm, hypoxia, and cellular senescence: From molecular mechanisms to targeted strategies

Cellular senescence precipitates a decline in physiological activities and metabolic functions, often accompanied by heightened inflammatory responses, diminished immune function, and impaired tissue and organ performance. Despite extensive research, the mechanisms underpinning cellular senescence remain incompletely elucidated. Emerging evidence implicates circadian rhythm and hypoxia as pivotal factors in cellular senescence. Circadian proteins are central to the molecular mechanism governing circadian rhythm, which regulates homeostasis throughout the body. These proteins mediate responses to hypoxic stress and influence the progression of cellular senescence, with protein Brain and muscle arnt-like 1 (BMAL1 or Arntl) playing a prominent role. Hypoxia-inducible factor-1α (HIF-1α), a key regulator of oxygen homeostasis within the cellular microenvironment, orchestrates the transcription of genes involved in various physiological processes. HIF-1α not only impacts normal circadian rhythm functions but also can induce or inhibit cellular senescence. Notably, HIF-1α may aberrantly interact with BMAL1, forming the HIF-1α-BMAL1 heterodimer, which can instigate multiple physiological dysfunctions. This heterodimer is hypothesized to modulate cellular senescence by affecting the molecular mechanism of circadian rhythm and hypoxia signaling pathways. In this review, we elucidate the intricate relationships among circadian rhythm, hypoxia, and cellular senescence. We synthesize diverse evidence to discuss their underlying mechanisms and identify novel therapeutic targets to address cellular senescence. Additionally, we discuss current challenges and suggest potential directions for future research. This work aims to deepen our understanding of the interplay between circadian rhythm, hypoxia, and cellular senescence, ultimately facilitating the development of therapeutic strategies for aging and related diseases.

Sulforaphane substantially impedes testicular ferroptosis in adult rats exposed to di-2-ethylhexyl phthalate through activation of NRF-2/SLC7A11/GPX-4 trajectory

Di-2-ethylhexyl phthalate (DEHP) is a common plasticizer with a deleterious impact on testicular functionality and male fertility. Growing evidence implicates ferroptosis as one of the plausible mechanisms for DEHP-induced testicular injury. Sulforaphane (SFN) is a natural isothiocyanate displaying beneficial effects on testicular injury in several animal models. Herein, we explored the potential protective effect of SFN on testicular ferroptosis and toxicity evoked by DEHP. Adult male Wistar rats were equally distributed into three groups (n = 6/group): (i) CON group; (ii) DEHP group, received DEHP (2 g/kg PO) for 4 weeks; and (iii) DEHP + SFN group, received SFN (10 mg/kg, PO) 1 week prior to DEHP then concurrently with DEHP for further 4 weeks. Compared to CON group, exposure to DEHP caused testicular atrophy, deteriorated testicular architecture, testicular fibrosis, reduced sperm count and motility, higher sperm deformity, and declined serum testosterone level. All these abnormalities were ameliorated by SFN preconditioning. Additionally, pretreatment with SFN reversed the increased aromatase level and upregulated the steroidogenic markers in testes of DEHP-exposed rats. SFN pretreatment also counteracted DEHP-induced oxidative stress and boosted the total antioxidant capacity in testicular tissue via activation of the nuclear factor erythroid 2-related factor 2 (NRF-2) and its downstream target, hemeoxygenase-1 (HO-1). Moreover, SFN preconditioning mitigated DEHP-induced ferroptosis through up-surging SLC7A11, GPX-4, and GSH, while suppressing iron overload and ACSL4-induced lipid peroxidation in testicular tissue of rats. These findings may nominate SFN as a promising protective intervention to alleviate testicular ferroptosis associated with DEHP exposure through activation of NRF-2/SLC7A11/GPX-4 trajectory.

Bio-nanocomplexes impair iron homeostasis to induce non-canonical ferroptosis in cancer cells

The targeted elevation of the labile iron pool (LIP) represents the most direct and effective strategy to induce ferroptosis in cancer cells. However, the efficiency of increasing LIP to induce ferroptosis via iron supplementation is controversial due to the iron homeostasis between LIP and storage iron pool, leading to poor effects and serious safety concerns. In this study, a bio-nanocomplex named AbDA-Lim, composed of albumin, polydopamine, and limonene, is prepared to promote LIP and induce non-canonical ferroptosis in cancer cells by destroying the iron balance. Albumin avidity drives AbDA-Lim entering cancer cells. Subsequently, the released polydopamine enhances the expression of HMOX1 to degrade haem and facilitate the transformation of Fe (III) to Fe (II). Meanwhile, limonene reduces glutathione (GSH) levels via inhibiting CBS, thereby, triggering the release of Fe (II) into LIP from its GSH-bound storage state. The augmentation of LIP ultimately triggers non-canonical ferroptosis in cancer cells. Furthermore, the photothermal property of polydopamine augments the synergistic anti-tumor efficiency of AbDA-Lim by incorporating photothermal therapy. This study presents a distinctive, cascading, and biotic strategy for promoting LIP non-canonically to induce ferroptosis.

Naringin Suppresses CoCl2-Induced Ferroptosis in ARPE-19 Cells

Hypoxic damage to retinal pigment epithelial (RPE) cells and subsequent neovascularization are key factors in the pathogenesis of branch retinal vein occlusion (BRVO). Naringin (NG), a naturally occurring flavanone glycoside, has demonstrated significant antioxidant and anti-neovascular activities. However, the regulatory effects and mechanisms of NG on ferroptosis in BRVO are yet to be explored. Our study aimed to investigate the protective effects of NG on RPE cells under hypoxic stress and to elucidate the underlying molecular mechanisms. Our findings revealed that NG significantly reduced cytotoxicity induced by cobaltous chloride (CoCl2) and also inhibited vascular proliferation in the retina, thereby attenuating choroidal neovascularization. NG pretreatment largely countered the overproduction of reactive oxygen species (ROS) and malondialdehyde (MDA) triggered by hypoxic damage, while also restoring levels of the antioxidants glutathione (GSH) and superoxide dismutase (SOD). Furthermore, NG pretreatment significantly activated the expression of hypoxia-inducible factor-1 alpha (HIF-1α) and its downstream heme oxygenase-1 (HO-1) and NADPH dehydrogenase (NQO1). In conclusion, NG not only inhibits neovascularization but also alleviates inflammation in RPE cells by modulating the HO-1/GPX4 pathway to inhibit ferroptosis. These findings highlight the potential of NG as a promising therapeutic agent for the treatment of BRVO.

Signaling Pathways Involved in Acute Pancreatitis

Acute pancreatitis (AP) is a common digestive emergency with high morbidity and mortality. Over the past decade, significant progress has been made in understanding the mechanisms of AP, including oxidative stress, disruptions in calcium homeostasis, endoplasmic reticulum stress, inflammatory responses, and various forms of cell death. This review provides an overview of the typical signaling pathways involved and proposes the latest clinical translation prospects. These strategies are important for the early management of AP, preventing multi-organ injury, and improving the overall prognosis of the disease.

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.

Juglone induces ferroptotic effect on hepatocellular carcinoma and pan-cancer via the FOSL1-HMOX1 axis

BACKGROUND

Drug therapy plays an essential role in the management of hepatocellular carcinoma (HCC). Recently, the use of natural products to suppress tumor cells has emerged as a promising direction for drug development. Juglone, a natural compound, exhibits anticancer activities across various cancer types. However, the precise mechanism underlying the anticancer effect of juglone, especially in HCC, remains elusive.

PURPOSE

This study aimed to investigate the potential inhibitory effects of juglone on HCC and pan-cancer, as well as elucidate the underlying mechanism.

METHODS

Cell Counting Kit-8 and colony formation assays were used to examine cell proliferation. Transwell and wound healing assays were used to evaluate cell migration. Cell cycle distribution was assessed by flow cytometry. The in vivo effect of juglone on HCC was evaluated by establishing the HCC xenograft mice model. RNA sequencing and inhibitors targeting diverse modes of programmed cell death were applied to uncover the form of juglone-induced cell death. Integrated transcriptomic, and proteomic analyses unveiled the underlying mechanism. The dual-luciferase reporter assay was employed to verify the findings. The pan-cancer value of juglone was assessed using TCGA database analysis and cellular assays.

RESULTS

Juglone suppressed HCC growth via ferroptosis in vitro and in vivo, which is evidenced by increased levels of iron, lipid peroxidation (LPO), reactive oxygen species (ROS), malondialdehyde (MDA), and decreased levels of glutathione (GSH). Omic analyses, gene silencing and functional analyses showed the upregulated HMOX1 and FOSL1 were the key effector molecule and transcriptional factor in juglone-induced ferroptosis, respectively. The binding site of FOSL1 at the promoter of HMOX1 was identified. Juglone could induce ferroptosis in pan-cancer by activating the FOSL1-HMOX1 axis.

CONCLUSION

Our findings, for the first time, demonstrate that juglone effectively inhibits tumor growth by inducing FOSL1-HMOX1-dependent ferroptosis, thereby offering a promising strategy for the development of anticancer drugs.

Melanoma bone metastasis-induced osteocyte ferroptosis via the HIF1α-HMOX1 axis

Osteocytes are the main cells in mineralized bone tissue. Elevated osteocyte apoptosis has been observed in lytic bone lesions of patients with multiple myeloma. However, their precise contribution to bone metastasis remains unclear. Here, we investigated the pathogenic mechanisms driving melanoma-induced osteocyte death. Both in vivo models and in vitro assays were combined with untargeted RNA sequencing approaches to explore the pathways governing melanoma-induced osteocyte death. We could show that ferroptosis is the primary mechanism behind osteocyte death in the context of melanoma bone metastasis. HMOX1 was identified as a crucial regulatory factor in this process, directly involved in inducing ferroptosis and affecting osteocyte viability. We uncover a non-canonical pathway that involves excessive autophagy-mediated ferritin degradation, highlighting the complex relationship between autophagy and ferroptosis in melanoma-induced osteocyte death. In addition, HIF1α pathway was shown as an upstream regulator, providing a potential target for modulating HMOX1 expression and influencing autophagy-dependent ferroptosis. In conclusion, our study provides insight into the pathogenic mechanisms of osteocyte death induced by melanoma bone metastasis, with a specific focus on ferroptosis and its regulation. This would enhance our comprehension of melanoma-induced osteocyte death.

Phthalates toxicity in vivo to rats, mice, birds, and fish: A thematic scoping review

Background

Phthalates, a large group of endocrine disruptors, are ubiquitous in the environment and detrimental to human health. This scoping review aimed to summarize the effects of phthalates on laboratory animals relevant to humans, assess toxicity, and analyze mechanisms of toxicity for public health concerns.

Methods

Articles were retrieved from Google Scholar, PubMed, ScienceDirect, and Web of Science search engines. The search used the term "toxicity of phthalates in vivo, animals or birds or fish." Original research articles published between 2010 and 2024 describing in vivo toxicity in rat, mouse, bird, and fish models, were included. Conversely, articles that did not meet the above criteria were excluded from this scoping review. Two authors independently extracted data using data extraction tools based on themes, while a third arbitrated if consensus was not met. A senior researcher developed the themes, which were further refined through discussions. Data analysis involved quantitative (percentage of studies) and qualitative (content analysis) methods.

Results

Of the 8180 articles screened, 153 met the inclusion criteria. Most of them were published after 2015 (74.50 %). The scoping review showed that DEHP (56.20 %) and DBP (21.57 %) were the most studied phthalates followed by BBP, DiBP, DMP, DEP, BBOP, and DiNP. Scarce data were available on DnOP, DPHP, DPeP, DUDP, DTDP, DMiP, and DiOP. Interestingly, studies of combinations of two or more phthalates were also present. The main laboratory animals employed were rats (48.37 %) and mice (39.87 %), while the least studied were birds (5.22 %) and fish (6.53 %). Most studies related to testicular toxicity (37.60 %), hepatotoxicity (23.53 %), and ovarian toxicity (18.30 %) investigations, while the rest consisted of neurotoxicity (6.88 %), renal toxicity (6.53 %), and thyroid toxicity studies (4.57 %). Studies focused on oxidative stress (34.64 %), apoptosis (22.22 %), steroid hormone deprivation (20.26 %), lipid metabolism disorder (11.76 %), and immunotoxicity (5.88 %) as mechanisms of toxicity. The most commonly used techniques were H&E, RT-qPCR, ROS assay, WB, IHC, ELISA, RIA, TUNEL, TEM, IFM, FCM, and RNA-seq.

Conclusions

DEHP and DBP are the most toxic and studied phthalates, while BBP, DiNP, DiBP, DiDP, BBOP, DMP, and DiOP and their combinations require more accurate studies to confirm their toxic effects on human health and mechanisms of action. These will assist policymakers in adopting strategies to minimize public exposure and adverse effects.

Di (2-ethylhexyl) phthalate reduces sperm motility by decreasing sperm tail energy supply

Di (2-ethylhexyl) phthalate (DEHP) is widespread in the environment. It can impair sperm function through damaging the sperm development process. However, few studies have focused on the sperm tail that is directly related to sperm motility. In this study, we demonstrate that DEHP impedes the conversion of riboflavin in the mitochondrial sheath in the midsection of the sperm tail, resulting in reduced ATP (adenosine triphosphate) synthesis, thereby inhibiting sperm motility. The results of HPLC-MS/MS showed that DEHP metabolites were transported to the testes and epididium, indicating that MEHP (Mono-2-ethylexyl phthalate) could directly affect the espermatozoa of mature. Sperm motility analysis determined that sperm motility decreased with increasing DEHP concentration. The movement of sperm is mainly dependent on the tail motility, which is largely determined by tail structure and energy supply. Electron microscopy images illustrate that there are no observable changes in the basic kinematic structure of the sperm tail. However, DEHP causes a decrease in complex II activity of mitochondrial respiratory chain by interfering with the synthesis of the cofactor FAD (Flavin adenine dinucleotide), which leads to a decrease in ATP concentration. Therefore, DEHP exposure can reduce sperm motility by decreasing sperm tail energy supply. This study exemplifies the importance of the sperm tail in sperm dysfunction caused by environmental pollutants.

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.

Adolescent exposure to organophosphate insecticide malathion induces spermatogenesis dysfunction in mice by activating the HIF-1/MAPK/PI3K pathway

Chemical-caused reproductive dysfunction has emerged as a global public health concern. This study investigated the adverse effects of the organophosphorus pesticide malathion on reproductive function in adolescent male mice at environmentally relevant concentrations. The results indicated that eight-week malathion exposure reduced testis weight, caused sex and thyroid hormone disorders, and induced testicular spermatogenic epithelium damage and oxidative stress. Testicular RNA sequencing indicated that malathion significantly affected testicular energy metabolism, hypoxia-inducible factor 1 (HIF-1) signaling, and steroid hormone biosynthesis pathways. Malathion significantly increased the gene and protein expression of HIF-1α by upregulating key genes in the mitogen-activated protein kinase (MAPK) pathway (Map2k2, Mapk3, and Eif4e2) and the phosphatidylinositol 3-kinase (PI3K) pathway (Pik3r2 and Akt1). Furthermore, malathion downregulated HIF-1α degradation-regulating genes while upregulating anaerobic metabolism and inflammation-related genes, thereby inhibiting normoxia and promoting hypoxia processes. Testicular hypoxia subsequently induced steroid hormone biosynthesis disorders and spermatogenesis dysfunction. Molecular docking verified that malathion interfered with HIF-1α and steroid hormone synthases (CYP11A1, CYP17A1 and CYP19A1) by forming hydrogen bonds and hydrophobic interactions with these proteins. This study presents the first evidence that malathion triggers spermatogenesis dysfunction in mice through activating the HIF-1/MAPK/PI3K pathway, providing a comprehensive understanding of the reproductive toxicity risks associated with organophosphorus pesticides.

Esketamine alleviates ferroptosis-mediated acute lung injury by modulating the HIF-1α/HO-1 pathway

BACKGROUND

Alveolar epithelial cell (AEC) ferroptosis contributes to the progression of acute lung injury (ALI). Esketamine (ESK) is a new clinical sedative, anesthetic, and analgesic drug that has attracted substantial attention in mental health research because of its antidepressant effects. However, the effects of ESK on ferroptosis-mediated ALI remain unclear.

OBJECTIVE

This study aimed to explore the protective effect of ESK on AEC ferroptosis in ALI and its potential molecular mechanism in vivo and in vitro.

METHODS

The antiferroptotic and anti-inflammatory effects of ESK were assessed in a mouse model of lipopolysaccharide (LPS)-induced ALI. In vitro, the epithelial cell lines MLE-12 and A549 were used to examine the underlying mechanism by which ESK regulates inflammation and ferroptosis.

RESULTS

ESK protected mice against LPS-induced ALI, significantly attenuated pathological changes in the lungs and decreased inflammation and ferroptosis. In vitro, ESK inhibited LPS-induced inflammation and ferroptosis in MLE-12 and A549 cells. Moreover, ferroptosis mediated inflammation in LPS-induced ALI in vivo and in vitro, and ESK decreased the LPS-induced inflammatory response by suppressing ferroptosis. ESK promoted the HIF-1α/HO-1 pathway in LPS-treated AECs and in the lung tissues of mice with LPS-induced ALI. Moreover, pretreatment with ESK and the HIF-1α stabilizer dimethyloxaloylglycine (DMOG) substantially attenuated lung injury and prevented changes in ferroptosis-related biochemical indicators, including glutathione (GSH) depletion, malondialdehyde (MDA) production and glutathione peroxidase 4 (GPX4) downregulation, in untreated LPS-induced mice but not in LPS-induced mice treated with the HO-1 inhibitor zinc protoporphyrin (ZNPP). Similar effects were observed in vitro in HO-1 siRNA-transfected A549 cells after LPS incubation but not in control siRNA-transfected cells.

CONCLUSION

ESK can inhibit ferroptosis-mediated lipid peroxidation by increasing the expression of HIF-1α/HO-1 pathway, highlighting the potential of ESK to treat LPS-induced ALI.

Proteome-wide Mendelian randomization and functional studies uncover therapeutic targets for polycystic ovarian syndrome

Polycystic ovarian syndrome (PCOS) is an endocrine syndrome that affects a large portion of women worldwide. This proteogenomic and functional study aimed to uncover candidate therapeutic targets for PCOS. We comprehensively investigated the causal association between circulating proteins and PCOS using two-sample Mendelian randomization analysis. Cis-protein quantitative trait loci were derived from six genome-wide association studies (GWASs) on plasma proteome. Genetic associations with PCOS were obtained from a large-scale GWAS meta-analysis, FinnGen cohort, and UK Biobank. Colocalization analyses were performed to prioritize the causal role of candidate proteins. Protein-protein interaction (PPI) and druggability evaluation assessed the druggability of candidate proteins. We evaluated the enrichment of tier 1 and 2 candidate proteins in individuals with PCOS and a mouse model and explored the potential application of the identified drug target. Genetically predicted levels of 65 proteins exhibited associations with PCOS risk, with 30 proteins showing elevated levels and 35 proteins showing decreased levels linked to higher susceptibility. PPI analyses revealed that FSHB, POSTN, CCN2, and CXCL11 interacted with targets of current PCOS medications. Eighty medications targeting 20 proteins showed their potential for repurposing as therapeutic targets for PCOS. EGLN1 levels were elevated in granulosa cells and the plasma of individuals with PCOS and in the plasma and ovaries of dehydroepiandrosterone (DHEA)-induced PCOS mouse model. As an EGLN1 inhibitor, administration of roxadustat in the PCOS mouse model elucidated the EGLN1-HIF1α-ferroptosis axis in inducing PCOS and validated its therapeutic effect in PCOS. Our study identifies candidate proteins causally associated with PCOS risk and suggests that targeting EGLN1 provides a promising treatment strategy.

High-fat diet led to testicular inflammation and ferroptosis via dysbiosis of gut microbes

The disorder of gut microbiota has negative impact on male reproductive, and testicular damage is associated with obesity. However, the detailed mechanism of gut microbiota on the obesity-induced testis injury are still unknown. Therefore, we constructed a mouse model to investigate the effects of obesity on testis injury. In this study, we found that HFD-induced obesity could disorder gut microbiota homeostasis, which increased the abundance of Brevundimonas, Desulfovibrionaceae_unclassified and Ralstonia, ultimately leading to the overproduction of lipopolysaccharides (LPS). Meanwhile, HFD-feeding promoted intestinal permeability via inhibiting expression of tight junction proteins (ZO-1, Occludin and Claudin) and reducing excretion of mucus, leading to translocation of LPS. The over-accumulation of LPS in the bloodstream triggered an inflammatory response by activating TLR4/NF-κB pathway in testis. On the other hand, the gut microbiota produced-LPS also could induce ferroptosis in testis, as reflected by enhancing iron content and lipid peroxidation (MDA), as well as decreasing ferroptosis-related proteins, including GPX4, FTH1 and SLC1A11. Moreover, inhibition of LPS ligand (TLR4) with Resatorvid (TAK-242) alleviated obesity-induced testis injury through suppression of inflammation and ferroptosis. In conclusion, this study provides novel insights into the underlying mechanisms of obesity-related testis injury induced by gut microbiota disorder via the gut-testis axis, thus offering potential targets to counteract obesity-induced male reproductive disorder.

Transcriptomic analysis and validation study of key genes and the HIF‑1α/HO‑1 pathway associated with ferroptosis in neutrophilic asthma

Ferroptosis, as a unique form of cell death caused by iron overload and lipid peroxidation, is involved in the pathogenesis of various inflammatory diseases of the airways. Inhibition of ferroptosis has become a novel strategy for reducing airway epithelial cell death and improving airway inflammation. The aim of the present study was to analyze and validate the key genes and signaling pathways associated with ferroptosis by bioinformatic methods combined with experimental analyzes in vitro and in vivo to aid the diagnosis and treatment of neutrophilic asthma. A total of 1,639 differentially expressed genes (DEGs) were identified in the transcriptome dataset. After overlapping with ferroptosis-related genes, 11 differentially expressed ferroptosis-related genes (DE-FRGs) were obtained. A new diagnostic model was constructed by these DE-FRGs from the transcriptome dataset with those from the GSE108417 dataset. The receiver operating characteristic curve analysis indicated that the area under the curve had good diagnostic performance (>0.8). As a result, four key DE-FRGs (CXCL2, HMOX1, IL-6 and SLC7A5) and biological pathway [hypoxia-inducible factor 1 (HIF-1) signaling pathway] associated with ferroptosis in neutrophilic asthma were identified by the bioinformatics analysis combined with experimental validation. The upstream regulatory network of key DE-FRGs and target drugs were predicted and the molecular docking results from screened 37 potential therapeutic drugs revealed that the 13 small-molecule drugs exhibited a higher stable binding to the primary proteins of key DE-FRGs. The results suggested that four key DE-FRGs and the HIF-1α/heme oxygenase 1 pathway associated with ferroptosis have potential as novel markers or targets for the diagnosis or treatment of neutrophilic asthma.

Shikonin induces ferroptosis in osteosarcomas through the mitochondrial ROS-regulated HIF-1α/HO-1 axis

BACKGROUND

The most common malignant bone tumour is osteosarcoma, which has an unsatisfactory prognosis and unsatisfactory treatment. Ferroptosis shows promise as an effective OS therapy. A substance extracted from the Lithospermum erythrorhizon, Shikonin (SHK), inhibits a number of tumours, including ovarian, gastric, and lung cancers. However, whether SHK induces OS ferroptosis and its mechanisms are not clear.

PURPOSE

Our study is aimed at investigating whether SHK causes ferroptosis and elucidating its molecular mechanism.

METHODS

Cell counting Kit-8, cell cycle and cell apoptosis assay were utilised to assess therapeutic effect of SHK against OS. Normal cells, including H9C2, AML-12 and HK-2, haematoxylin and eosin staining and mice serum biomarker tests were used to assess SHK biosafety. Malondialdehyde (MDA) levels, the glutathione (GSH)/oxidized glutathione (GSSG) ratio, reactive oxygen species (ROS), lipid peroxide (LPO), and intracellular Fe2+ detection, quantitative reverse transcription PCR (qRT-PCR), Western blotting (WB) and rescue experiments were employed to confirm whether SHK induced ferroptosis in OS cells. Molecular docking, cellular thermal shift assay (CETSA), and drug affinity responsive target stability (DARTS) assay were used to evaluate the direct binding between SHK and hypoxia-inducible factor-1α (HIF-1α). Protein stability and degradation analysis, small RNA interference, flow cytometry, qRT-PCR, and WB were used to investigate the molecular mechanism of ferroptosis. In vivo xenografts of nude mouse was used to study the anti-OS effect of SHK.

RESULTS

SHK significantly reduced OS cell viability and induced apoptosis and G2/M arrest. SHK increased intracellular levels of MDA, ROS, LPO, and Fe2+ while simultaneously reducing the GSH/GSSG ratio and GPX4 and SLC7A11 expression. CETSA and DARTS results demonstrated that SHK did not bind targetly to HIF-1α. Instead, mitochondrial ROS (MitoROS) promoted HIF-1α expression, resulting in HO-1 overexpression, excess Fe2+ production, ROS accumulation and GPX depletion, and ferroptosis. Furthermore, inhibition of MitoROS using Mito-TEMPO downregulated HIF-1α/HO-1 axis and mitigated the SHK-induced ferroptosis. In vivo, SHK effectively suppressed OS growth with favourable biosafety, confirming the molecular mechanism underlying SHK-induced ferroptosis in OS.

CONCLUSION

We observe that HIF-1α/HO-1 axis is the crucial factor in SHK-induced OS ferroptosis. Importantly, we demonstrate that HIF-1α is indirectly regulated by MitoROS rather than SHK bound directly to HIF-1α. Our research suggest that SHK is a potential drug candidate for OS treatment and may help in identifying novel therapeutic targets for OS.

Radix Sanguisorbae Improves Intestinal Barrier in Septic Rats via HIF-1 α/HO-1/Fe2+ Axis

OBJECTIVE

To investigate whether Radix Sanguisorbae (RS, Diyu) could restore intestinal barrier function following sepsis using a cecal ligation and puncture (CLP)-induced septic rat model and lipopolysaccharide (LPS)-challenged IEC-6 cell model, respectively.

METHODS

Totally 224 rats were divided into 4 groups including a control, sham, CLP and RS group according to a random number table. The rats in the control group were administrated with Ringer's lactate solution (30 mL/kg) with additional dopamine [10 µ g/(kg·min)] and given intramuscular injections of cefuroxime sodium (10 mg/kg) 12 h following CLP. The rats in the RS group were administrated with RS (10 mg/kg) through tail vein 1 h before CLP and treated with RS (10 mg/kg) 12 h following CLP. The rats in the sham group were only performed abdominal surgery without CLP. The rats in the CLP group were performed with CLP without any treatment. The other steps were same as control group. The effects of RS on intestinal barrier function, mesenteric microvessels barrier function, multi-organ function indicators, inflammatory response and 72 h survival window following sepsis were observed. In vitro, the effects of RS on LPS-challenged IEC-6 cell viability, the expressions of zona occludens-1 (ZO-1) and ferroptosis index were evaluated by cell counting kit-8, immunofluorescence and Western blot analysis. Bioinformatic tools were applied to investigate the pharmacological network of RS in sepsis to predict the active compounds and potential protein targets and pathways.

RESULTS

The sepsis caused severe intestinal barrier dysfunction, multi-organ injury, lipid peroxidation accumulation, and ferroptosis in vivo. RS treatment significantly prolonged the survival time to 56 h and increased 72-h survival rate to 7/16 (43.75%). RS also improved intestinal barrier function and relieved intestinal inflammation. Moreover, RS significantly decreased lipid peroxidation and inhibited ferroptosis (P<0.05 or P<0.01). Administration of RS significantly worked better than Ringer's solution used alone. Using network pharmacology prediction, we found that ferroptosis and hypoxia inducible factor-1 (HIF-1 α) signaling pathways might be involved in RS effects on sepsis. Subsequent Western blot, ferrous iron measurements, and FerroOrange fluorescence of ferrous iron verified the network pharmacology predictions.

CONCLUSION

RS improved the intestinal barrier function and alleviated intestinal injury by inhibiting ferroptosis, which was related in part to HIF-1 α/heme oxygenase-1/Fe2+ axis.

Di-(2-ethylhexyl) phthalate induces prepubertal testicular injury through MAM-related mitochondrial calcium overload in Leydig and Sertoli cell apoptosis

As one of the most prevalent environmental endocrine disruptors, di-(2-ethylhexyl) phthalate (DEHP) is known for its significant developmental toxicity to the male reproductive system in humans and mice. Prepubertal exposure to DEHP has been shown to cause testicular damage, but the underlying mechanisms require further investigation. To investigate this effect, prepubertal mice were exposed to 100, 250 or 500 mg/kg body weight (bw) of DEHP for 14 days, which resulted in impaired histological structure and increased apoptosis of the testes. RNA sequencing (RNA-seq) of testicular tissue suggested that DEHP led to injury in Leydig and Sertoli cells. To further elucidate these mechanisms, we conducted experiments using immature mouse Leydig (TM3) and Sertoli (TM4) cells, and exposed them to 200 μM mono-(2-ethylhexyl) phthalate (MEHP), the primary metabolite of DEHP, for 24 h. We found that MEHP exposure induced oxidative stress injury and promoted cell apoptosis, and that cotreatment with N-acetylcysteine partially reversed these injuries. Given the close association between oxidative stress and mitochondrial calcium levels, we demonstrated that MEHP exposure disrupted mitochondria and increased mitochondrial calcium levels. In addition, MEHP exposure facilitated the formation of mitochondria-associated endoplasmic reticulum membranes (MAMs), upregulated protein expression and enhanced the interactions of the IP3R3-Grp75-VDAC1 complex. Furthermore, inhibition of calcium transfer in the IP3R3-Grp75-VDAC1-MCU axis relieved MEHP-induced mitochondrial injury, oxidative stress and apoptosis in TM3 and TM4 cells. This study highlights the importance of MAM-mediated mitochondrial calcium overload and the subsequent apoptosis of Leydig and Sertoli cells as pivotal factors contributing to testicular injury induced by prepubertal exposure to DEHP.

Propafenone facilitates mitochondrial-associated ferroptosis and synergizes with immunotherapy in melanoma

BACKGROUND

Despite the successful application of immunotherapy, both innate and acquired resistance are typical in melanoma. Ferroptosis induction appears to be a potential strategy to enhance the effectiveness of immunotherapy. However, the relationship between the status of ferroptosis and the effectiveness of immunotherapy, as well as viable strategies to augment ferroptosis, remains unclear.

METHODS

A screening of 200 cardiovascular drugs obtained from the Food and Drug Administration-approved drug library was conducted to identify the potential ferroptosis sensitizer. In vitro and in vivo experiments explored the effects of propafenone on ferroptosis in melanoma. Animal models and transcriptomic analyses evaluated the therapeutic effects and survival benefits of propafenone combined with immune checkpoint blockades (ICBs). The relationship between propafenone targets and the efficacy of ICBs was validated using the Xiangya melanoma data set and publicly available clinical data sets.

RESULTS

Through large-scale drug screening of cardiovascular drugs, we identified propafenone, an anti-arrhythmia medication, as capable of synergizing with ferroptosis inducers in melanoma. Furthermore, we observed that propafenone, in combination with glutathione peroxidase 4 inhibitor RSL3, collaboratively induces mitochondrial-associated ferroptosis. Mechanistically, propafenone transcriptionally upregulates mitochondrial heme oxygenase 1 through the activation of the Jun N-terminal kinase (JNK)/JUN signaling pathway under RSL3 treatment, leading to overloaded ferrous iron and reactive oxygen species within the mitochondria. In xenograft models, the combination of propafenone and ferroptosis induction led to nearly complete tumor regression and prolonged survival. Consistently, propafenone enhances immunotherapy-induced tumorous ferroptosis and antitumor immunity in tumor-bearing mice. Significantly, patients exhibiting high levels of ferroptosis/JUN/HMOX1 exhibited improved efficacy of immunotherapy and prolonged progression-free survival.

CONCLUSIONS

Taken together, our findings suggest that propafenone holds promise as a candidate drug for enhancing the efficacy of immunotherapy and other ferroptosis-targeted therapies in the treatment of melanoma.

Bioinformatics Identification and Validation of Ferroptosis-Related Key Genes and Therapeutic Compounds in Septic Lung Injury

Background

Septic lung injury (SLI) is a severe condition with high mortality, and ferroptosis, a form of programmed cell death, is implicated in its pathogenesis. However, the explicit mechanisms underlying this condition remain unclear. This study aimed to elucidate and validate key ferroptosis-related genes involved in the pathogenesis of SLI through bioinformatics analysis and experimental validation.

Methods

Microarray data related to SLI from the GSE130936 dataset were downloaded from the Gene Expression Omnibus (GEO) database. These data were then intersected with the FerrDb database to obtain ferroptosis-related differentially expressed genes (DEGs). Protein-protein interaction (PPI) networks and functional enrichment analysis were employed to identify key ferroptosis-related DEGs. The Connectivity Map (c-MAP) tool was used to search for potential compounds or drugs that may inhibit ferroptosis-related DEGs. The transcriptional levels of the key genes and potential therapeutic compounds were verified in an LPS-induced mouse model of lung injury. The expression of these key genes was further verified using the GSE60088 and GSE137342 datasets.

Results

38 ferroptosis-related DEGs were identified between the septic and control mice. PPI network analysis revealed four modules, the most significant of which included eight ferroptosis-related DEGs. Functional enrichment analysis showed that these genes were enriched in the HIF-1 signaling pathway, including IL-6 (Interleukin-6), TIMP1 (Tissue Inhibitor of Metalloproteinase 1), HIF-1α (Hypoxia-Inducible Factor-1α), and HMOX1 (Heme Oxygenase-1). Phloretin, a natural compound, was identified as a potential inhibitor of these genes. Treatment with phloretin significantly reduced the expression of these genes (p < 0.05), mitigated lung injury, improved inflammatory profiles by approximately 50%, and ferroptosis profiles by nearly 30% in the SLI models.

Conclusion

This study elucidates the significant role of ferroptosis in SLI and identifies phloretin as a potential therapeutic agent. However, further research, particularly involving human clinical trials, is necessary to validate these findings for clinical use.

Proteomic and lipidomic analysis of the mechanism underlying astragaloside IV in mitigating ferroptosis through hypoxia-inducible factor 1α/heme oxygenase 1 pathway in renal tubular epithelial cells in diabetic kidney disease

ETHNOPHARMACOLOGICAL RELEVANCE

The limitations of modern medicine in mitigating the pathological process of diabetic kidney disease (DKD) necessitate novel, precise, and effective prevention and treatment methods. Huangqi, the root of Astragalus membranaceus Fisch. ex Bunge has been used in traditional Chinese medicine for various kidney ailments. Astragaloside IV (AS-IV), the primary pharmacologically active compound in A. membranaceus, is involved in lipid metabolism regulation; however, its potential in ameliorating renal damage in DKD remains unexplored.

AIM OF THE STUDY

To elucidate the specific mechanism by which AS-IV moderates DKD progression.

MATERIALS AND METHODS

A murine model of DKD and high glucose-induced HK-2 cells were treated with AS-IV. Furthermore, multiomics analysis, molecular docking, and molecular dynamics simulations were performed to elucidate the mechanism of action of AS-IV in DKD, which was validated using molecular biological methods.

RESULTS

AS-IV regulated glucose and lipid metabolism in DKD, thereby mitigating lipid deposition in the kidneys. Proteomic analysis identified 12 proteins associated with lipid metabolism regulated by AS-IV in the DKD renal tissue. Additionally, lipid metabolomic analysis revealed that AS-IV upregulated and downregulated 4 beneficial and 79 harmful lipid metabolites, respectively. Multiomics analysis further indicated a positive correlation between the top-ranked differential protein heme oxygenase (HMOX)1 and the levels of various harmful lipid metabolites and a negative correlation with the levels of beneficial lipid metabolites. Furthermore, enrichment of both ferroptosis and hypoxia-inducible factor (HIF)-1 signaling pathways during the AS-IV treatment of DKD was observed using proteomic analysis. Validation results showed that AS-IV effectively reduced ferroptosis in DKD-affected renal tubular epithelial cells by inhibiting HIF-1α/HMOX1 pathway activity, upregulating glutathione peroxidase-4 and ferritin heavy chain-1 expression, and downregulating acyl-CoA synthetase long-chain family member-4 and transferrin receptor-1 expression. Our findings demonstrate the potential of AS-IV in mitigating DKD pathology by downregulating the HIF-1α/HMOX1 signaling pathway, thereby averting ferroptosis in renal tubular epithelial cells.

CONCLUSIONS

AS-IV is a promising treatment strategy for DKD via the inhibition of ferroptosis in renal tubular epithelial cells. The findings of this study may help facilitate the development of novel therapeutic strategies.

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.

Environmental endocrine disrupting chemical-DEHP exposure-provoked biotoxicity about microbiota-gut-mammary axis in lactating mice via multi-omics technologies

Plastics, pervasive in humans and nature, often contain Di (2-ethylhexyl) phthalate (DEHP) that enhance plastic's elasticity. However, DEHP is an environmental endocrine disruptor, affecting organisms upon exposure. Understanding mammary gland development in lactating females is crucial for offspring nourishment and dairy production. Employing multi-omics technology, this study aimed to uncover DEHP's impact on the microbial-gut-mammary axis. Forty mice were exposed to varying DEHP doses for 18 d. We performed 16S sequencing, metabolomics, mammary tissue observation, and gene expression profiling. Results revealed DEHP's influence on microbial diversity, with increased Lactobacillus abundance and reduced Proteobacteria, alongside colonic inflammation. Elevated GMP and adenosine 5'-monophosphate levels in the bloodstream were noted, while ascorbic acid, glycitein, and others decreased. MEHP, a DEHP metabolite, damaged mammary tissues, inhibiting ERK1/2 phosphorylation, triggering apoptosis and ferroptosis. These findings unveil potential therapeutic targets for DEHP-induced chronic toxicity in humans and animals, aiding dairy livestock health and human well-being. This study underscores the importance of understanding the adverse effects of DEHP exposure on mammalian systems.

2,2',4,4'-Tetrabromodiphenyl ether exposure disrupts blood-testis barrier integrity through CMA-mediated ferroptosis

2,2',4,4'-Tetrabromodiphenyl ether (PBDE-47), being the most prevalent congener of polybrominated diphenyl ethers (PBDEs), has been found to accumulate greatly in the environment and induce spermatogenesis dysfunction. However, the specific underlying factors and mechanisms have not been elucidated. Herein, male Sprague-Dawley (SD) rats were exposed to corn oil, 10 mg/kg body weight (bw) PBDE-47 or 20 mg/kg bw PBDE-47 by gavage for 30 days. PBDE-47 exposure led to blood-testis barrier (BTB) integrity disruption and aberrant spermatogenesis. Given that Sertoli cells are the main toxicant target, to explore the potential mechanism involved, we performed RNA sequencing (RNA-seq) in Sertoli cells, and the differentially expressed genes were shown to be enriched in ferroptosis and lysosomal pathways. We subsequently demonstrated that ferroptosis was obviously increased in testes and Sertoli cells upon exposure to PBDE-47, and the junctional function of Sertoli cells was restored after treatment with the ferroptosis inhibitor ferrostatin-1. Since glutathione peroxidase 4 (GPX4) was dramatically reduced in PBDE-47-exposed testes and Sertoli cells and considering the RNA-sequencing results, we examined the activity of chaperone-mediated autophagy (CMA) and verified that the expression of LAMP2a and HSC70 was upregulated significantly after PBDE-47 exposure. Notably, Lamp2a knockdown not only inhibited ferroptosis by suppressing GPX4 degradation but also restored the impaired junctional function induced by PBDE-47. These collective findings strongly indicate that PBDE-47 induces Sertoli cell ferroptosis through CMA-mediated GPX4 degradation, resulting in decreased BTB-associated protein expression and eventually leading to BTB integrity disruption and spermatogenesis dysfunction.

FTO mediates bisphenol F-induced blood-testis barrier impairment through regulating ferroptosis via YTHDF1/TfRc and YTHDF2/SLC7A11 signal axis

Bisphenol F (BPF) has been extensively utilized in daily life, which brings new hazards to male reproductive health. However, the specific functional mechanism is still unclear. Both cell and animal models were utilized for exploring the role of RNA methylation and ferroptosis and its underlying mechanisms in male reproductive injury induced by BPF. In animal model, BPF severely destroyed the integrity of the blood-testis barrier (BTB) and induced ferroptosis. Furthermore, BPF significantly affected the barrier function of TM4 cells and promoted ferroptosis. Importantly, ChIP assays revealed that BPF inhibited AR transcriptional regulation of FTO and FTO expression was downregulated in TM4 cells. Overexpression of FTO prevented the impairment of BTB by inhibiting ferroptosis in TM4 cells. Mechanistically, FTO could significantly down-regulate the m6A modification level of TfRc and SLC7A11 mRNA through MeRIP experiment. RIP experiments showed that YTHDF1 can bind to TfRc mRNA and promote its translation while YTHDF2 could bind to SLC7A11 mRNA and reduce its mRNA stability. Therefore, our results suggest that FTO plays a key role in BPF induced male reproductive toxicity through YTHDF1-TfRc axis and YTHDF2-SLC7A11 axis and may provide new ideas and methods for the prevention and treatment of male reproductive diseases associated with environmental pollutants.

Di-(2-ethylhexyl) phthalate exposure induces ferroptosis by regulating the Nrf2-mediated signaling pathway in mouse ovaries

Di-(2-ethylhexyl) phthalate (DEHP), an endocrine-disrupting chemical present in plasticized products, exerts strong modulation on the anatomy and function of the female reproductive system. However, the potential mechanisms underlying DEHP-induced regulation of prepubertal female reproductive toxicity have not yet been elucidated. Therefore, this study was designed to elucidate the molecular mechanism of ovarian injury induced by DEHP exposure in mice. Elevated serum mono-2-ethylhexyl phthalate (MEHP) concentrations, decreased levels of ovarian hormones (E2 and P4), and observed ovarian injury were found after DEHP exposure. Ovarian transcriptome analysis revealed significant alterations in ferroptosis-associated gene expression, with potential regulation by Nrf2. Subsequent analysis of ferrous iron, malondialdehyde (MDA), Western blotting, and immunofluorescence of the ovaries confirmed the RNA-seq findings. Transcriptome analysis of granulosa cells revealed a direct or indirect regulatory relationship between Nrf2 and downstream ferroptosis-related proteins following MEHP exposure. Further experiments demonstrated that ferrostatin-1 attenuated MEHP-induced ferroptosis in granulosa cells. Additionally, Nrf2 stabilization and accumulation in the nucleus of granulosa cells were observed following MEHP treatment. RNAi-mediated knockdown of Nrf2 exacerbated MEHP-induced ferroptosis in granulosa cells. This evidence indicates that DEHP exposure induces ferroptosis through regulation of the Nrf2-mediated signaling pathway in mouse ovaries, laying the groundwork for future studies aiming to develop therapeutic strategies against DEHP toxicity.

Novel Insights into Ethanol-Soluble Oyster Peptide-Zinc-Chelating Agents: Structural Characterization, Chelation Mechanism, and Potential Protection on MEHP-Induced Leydig Cells

Numerous studies have reported that mono-(2-ethylhexyl) phthalate (MEHP) (bioactive metabolite of Di(2-ethylhexyl) phthalate) has inhibitory effects on Leydig cells. This study aims to prepare an oyster peptide-zinc complex (PEP-Zn) to alleviate MEHP-induced damage in Leydig cells. Zinc-binding peptides were obtained through the following processes: zinc-immobilized affinity chromatography (IMAC-Zn2+), liquid chromatography-mass spectrometry technology (LC-MS/MS) analysis, molecular docking, molecular dynamic simulation, and structural characterization. Then, the Zn-binding peptide (PEP) named Glu-His-Ala-Pro-Asn-His-Asp-Asn-Pro-Gly-Asp-Leu (EHAPNHDNPGDL) was identified. EHAPNHDNPGDL showed the highest zinc-chelating ability of 49.74 ± 1.44%, which was higher than that of the ethanol-soluble oyster peptides (27.50 ± 0.41%). In the EHAPNHDNPGDL-Zn complex, Asn-5, Asp-7, Asn-8, His-2, and Asp-11 played an important role in binding to the zinc ion. Additionally, EHAPNHDNPGDL-Zn was found to increase the cell viability, significantly increase the relative activity of antioxidant enzymes and testosterone content, and decrease malondialdehyde (MDA) content in MEHP-induced TM3 cells. The results also indicated that EHAPNHDNPGDL-Zn could alleviate MEHP-induced apoptosis by reducing the protein level of p53, p21, and Bax, and increasing the protein level of Bcl-2. These results indicate that the zinc-chelating peptides derived from oyster peptides could be used as a potential dietary zinc supplement.

High expression levels of haem oxygenase-1 promote ferroptosis in macrophage-derived foam cells and exacerbate plaque instability

Plaque rupture with consequent thrombosis is the leading cause of acute cardiovascular events, during which macrophage death is a hallmark. Ferroptosis is a pivotal intermediate link between early and advanced atherosclerosis. Existing evidence indicates the involvement of macrophage ferroptosis in plaque vulnerability; however, the exact mechanism remains elusive. The aim of this study was to explore key ferroptosis-related genes (FRGs) involved in plaque progression and the underlying molecular mechanisms involved. The expression landscape of FRGs was obtained from atherosclerosis-related GEO datasets. Molecular mechanism studies of ferroptosis were performed using bone marrow-derived macrophages (BMDMs) and macrophage-derived foam cells (MDFCs). Bioinformatics analysis and immunohistochemistry revealed that macrophage haem oxygenase-1 (HMOX1) is the key FRG involved in plaque destabilization. Hypoxic conditions induced a significant increase in Hmox1 expression in MDFCs but not in macrophages. In addition, the beneficial or deleterious effects of Hmox1 were dependent on the degree of Hmox1 induction. Hmox1 overexpression drove inflammatory responses and ferroptotic oxidative stress in MDFCs and aggravated the plaque burden in atherosclerotic model mice. Further mechanistic investigations demonstrated that hypoxia-mediated degradation of egl-9 family hypoxia-inducible factor 3 (Egln3) stabilized Hif1a, which subsequently promoted Hmox1 transcription. Our findings suggest that high Hmox1 expression under hypoxia is deleterious to MDFC viability and plaque stability, providing a reference for the management of acute cardiovascular events.

Comprehensive review of perioperative factors influencing ferroptosis

The perioperative period encompasses all phases of patient care from the decision to perform surgery until full recovery. Ferroptosis, a newly identified type of regulated cell death, influences a wide array of diseases, including those affecting the prognosis and regression of surgical patients, such as ischemia-reperfusion injury and perioperative cognitive dysfunction. This review systematically examines perioperative factors impacting ferroptosis such as surgical trauma-induced stress, tissue hypoxia, anesthetics, hypothermia, and blood transfusion. By analyzing their intrinsic relationships, we aim to improve intraoperative management, enhance perioperative safety, prevent complications, and support high-quality postoperative recovery, ultimately improving patient outcomes.

Di-(2-ethylhexyl) phthalate exposure induces premature testicular senescence by disrupting mitochondrial respiratory chain through STAT5B-mitoSTAT3 in Leydig cell

Di-(2-ethylhexyl) phthalate (DEHP), a prevalent plasticizer, is known to have endocrine-disrupting effects on males and cause reproductive toxicity. There were causal effects of DEHP on testosterone levels in the real world by Mendelian randomization analysis. Exposure to DEHP during the preadult stage might lead to premature testicular senescence, but the mechanisms responsible for this have yet to be determined. In this study, we administered DEHP (300 mg/kg/day) to male C57BL/6 mice from postnatal days 21 to 49. The mice were kept for 6 months without DEHP. RNA sequencing was conducted on testicular tissue at PNM6. The results indicated that DEHP hindered testicular development, lowered serum testosterone levels in male mice, and induced premature testicular senescence. TM3 Leydig cells were exposed to 300 μM of mono(2-ethylhexyl) phthalate (MEHP), the bioactive metabolite of DEHP, for 72 h. The results also found that DEHP/MEHP induced senescence in vivo and in vitro. The mitochondrial respiratory chain was disrupted in Leydig cells. The expression and stability of STAT5B were elevated by MEHP treatment in TM3 cells. Furthermore, p-ERK1/2 was significantly decreased by STAT5B, and mitochondria-STAT3 (p-STAT3 ser727) was significantly decreased due to the decrease of p-ERK1/2. Additionally, the senescence level of TM3 cells was decreased and treated with 5 mM NAC for 1 h after MEHP treatment. In conclusion, these findings provided a novel mechanistic understanding of Leydig cells by disrupting the mitochondrial respiratory chain through STAT5B-mitoSTAT3.

Effects of Cryptorchidism on the Semen Quality of Giant Pandas from the Perspective of Seminal Plasma Proteomics

Giant pandas are an endangered species with low reproductive rates. Cryptorchidism, which can negatively affect reproduction, is also often found in pandas. Seminal plasma plays a crucial role in sperm-environment interactions, and its properties are closely linked to conception potential in both natural and assisted reproduction. The research sought to identify seminal fluid protein content variations between normal and cryptorchid giant pandas. Methods: Using a label-free MS-based method, the semen proteomes of one panda with cryptorchidism and three normal pandas were studied, and the identified proteins were compared and functionally analyzed. Results: Mass spectrometry identified 2059 seminal plasma proteins, with 361 differentially expressed proteins (DEPs). Gene ontology (GO) analysis revealed that these DEPs are mainly involved in the phosphate-containing compound metabolic, hydrolase activity, and kinase activity areas (p ≤ 0.05). The KEGG functional enrichment analysis revealed that the top 20 pathways were notably concentrated in the adipocyte lipolysis and insulin metabolism pathway, with a significance level of p ≤ 0.05. Further analysis through a protein-protein interaction (PPI) network identified nine key proteins that may play crucial roles, including D2GXH8 (hexokinase Fragment), D2HSQ6 (protein tyrosine phosphatase), and G1LHZ6 (Calmodulin 2). Conclusions: We suspect that the high abundance of D2HSQ6 in cryptorchid individuals is associated with metabolic pathways, especially the insulin signal pathway, as a typical proteomic feature related to its pathological features. These findings offer insight into the ex situ breeding conditions of this threatened species.

Maslinic acid supplementation prevents di(2-ethylhexyl) phthalate-induced apoptosis via PRDX6 in peritubular myoid cells of Chinese forest musk deer

Chinese forest musk deer (FMD), an endangered species, have exhibited low reproductive rates even in captivity due to stress conditions. Investigation revealed the presence of di(2-ethylhexyl) phthalate (DEHP), an environmental endocrine disruptor, in the serum and skin of captive FMDs. Feeding FMDs with maslinic acid (MA) has been observed to alleviate the stress response and improve reproductive rates, although the precise molecular mechanisms remain unclear. Therefore, this study aims to investigate the molecular mechanisms underlying the alleviation of DEHP-induced oxidative stress and cell apoptosis in primary peritubular myoid cells (PMCs) through MA intake. Primary PMCs were isolated and exposed to DEHP in vitro. The results demonstrated that DEHP significantly suppressed antioxidant levels and promoted cell apoptosis in primary PMCs. Moreover, interfering with the expression of PRDX6 was found to induce excessive reactive oxygen species (ROS) production and cell apoptosis in primary PMCs. Supplementation with MA significantly upregulated the expression of PRDX6, thereby attenuating DEHP-induced oxidative stress and cell apoptosis in primary PMCs. These findings provide a theoretical foundation for mitigating stress levels and enhancing reproductive capacity of in captive FMDs.

The role of immune cell death in spermatogenesis and male fertility

The male reproductive system provides a distinctive shield to the immune system, safeguarding germ cells (GCs) from autoimmune harm. The testis in mammals creates a unique immunological setting due to its exceptional immune privilege and potent local innate immunity. which can result from a number of different circumstances, including disorders of the pituitary gland, GC aplasia, and immunological elements. Apoptosis, or programmed cell death (PCD), is essential for mammalian spermatogenesis to maintain and ensure an appropriate number of GCs that correspond with the supporting capability of the Sertoli cells. Apoptosis is substantial in controlling the number of GCs in the testis throughout spermatogenesis, and any dysregulation of this process has been linked to male infertility. There is a number of evidence about the potential of PCD in designing novel therapeutic approaches in the treatment of infertility. A detailed understanding of PCD and the processes that underlie immunological infertility can contribute to the progress in designing strategies to prevent and treat male infertility. This review will provide a summary of the role of immune cell death in male reproduction and infertility and describe the therapeutic strategies and agents for treatment based on immune cell death.

Concerted monoamine oxidase activity following exposure to di-2-ethylhexyl phthalate is associated with aggressive neurobehavioral response and neurodegeneration in zebrafish brain

Di-2-ethylhexyl phthalate (DEHP) is the most commonly preferred synthetic organic chemical in plastics and its products for making them ductile, flexible and durable. As DEHP is not chemically bound to the macromolecular polymer of plastics, it can be easily leached out to accumulate in food and environment. Our recent report advocated that exposure to DEHP significantly transformed the innate bottom-dwelling and scototaxis behaviour of zebrafish. Our present study aimed to understand the possible role of DEHP exposure pertaining towards the development of aggressive behaviour and its association with amplified monoamine oxidase activity and neurodegeneration in the zebrafish brain. As heightened monoamine oxidase (MAO) is linked with genesis of aggressive behaviour, our observation also coincides with DEHP-persuaded aggressive neurobehavioral transformation in zebrafish. Our preliminary findings also showed that DEHP epitomized as a prime factor in transforming native explorative behaviour and genesis of aggressive behaviour through oxidative stress induction and changes in the neuromorphology in the periventricular grey zone (PGZ) of the zebrafish brain. With the finding demarcating towards heightened chromatin condensation in the PGZ of zebrafish brain, our further observation by immunohistochemistry showed a profound augmentation in apoptotic cell death marker cleaved caspase 3 (CC3) expression following exposure to DEHP. Our further observation by immunoblotting study also demarcated a temporal augmentation in CC3 and tyrosine hydroxylase expression in the zebrafish brain. Therefore, the gross findings of the present study delineate the idea that chronic exposure to DEHP is associated with MAO-instigated aggressive neurobehavioral transformation and neurodegeneration in the zebrafish brain.

HO-1 activation contributes to cadmium-induced ferroptosis in renal tubular epithelial cells via increasing the labile iron pool and promoting mitochondrial ROS generation

Cadmium (Cd), a prevalent environmental contaminant, has attracted widespread attention due to its serious health hazards. Ferroptosis is a form of iron-dependent oxidative cell death that contributes to the development of various kidney diseases. However, the mechanisms underlying the occurrence of ferroptosis in Cd-induced renal tubular epithelial cells (TECs) have not been fully elucidated. Hereby, both in-vitro and in-vivo experiments were established to elucidate this issue. In this study, we found that Cd elicited accumulation of lipid peroxides due to intracellular ferrous ion (Fe2+) overload and glutathione depletion, contributing to ferroptosis. Inhibition of ferroptosis via chelation of Fe2+ or reduction of lipid peroxidation can significantly mitigate Cd-induced cytotoxicity. Renal transcriptome analysis revealed that the activation of heme oxygenase 1 (HO-1) was closely related to ferroptosis in Cd-induced TECs injury. Cd-induced ferroptosis and resultant TECs injury are significantly alleviated due to HO-1 inhibition, demonstrating the crucial role of HO-1 in Cd-triggered ferroptosis. Further studies showed that accumulation of lipid peroxides due to iron overload and mitochondrial ROS (mtROS) generation was responsible for HO-1-triggered ferroptosis in Cd-induced cytotoxicity. In conclusion, the current study demonstrates that excessively upregulating HO-1 promotes iron overload and mtROS overproduction to trigger ferroptosis in Cd-induced TECs injury, highlighting that targeting HO-1-mediated ferroptosis may provide new ideas for preventing Cd-induced nephrotoxicity.

Triptolide induced spermatogenesis dysfunction via ferroptosis activation by promoting K63-linked GPX4 polyubiquitination in spermatocytes

Triptolide (TP) is a major bioactive compound derived from Tripterygium wilfordii Hook. F. (TwHF) known for its medicinal properties, but it also exhibits potential toxic effects. It has been demonstrated to induce severe male reproductive toxicity, yet the precise mechanism behind this remains unclear, which limits its broad clinical application. This study aimed to investigate the mechanisms underlying testicular damage and spermatogenesis dysfunction induced by TP in mice, using both mouse models and the spermatocyte-derived cell line GC-2spd. In the present study, it was found that TP displayed significant testicular microstructure damaged and spermatogenesis defects including lower concentration and abnormal morphology by promoting ROS formation, MDA production and restraining GSH level, glutathione peroxidase 4 (GPX4) expression in vivo. Furthermore, Ferrostatin-1 (FER-1), a ferroptosis inhibitor, was found to significantly reduce the accumulation of lipid peroxidation, alleviate testicular microstructural damage, and enhance spermatogenic function in mice. Besides, notably decreased cell viability, collapsed mitochondrial membrane potential, and elevated DNA damage were observed in vitro. The above-mentioned phenomenon could be reversed by pre-treatment of FER-1, indicating that ferroptosis participated in the TP-mediated spermatogenesis dysfunction. Mechanistically, TP could enhance GPX4 ubiquitin degradation via triggering K63-linked polyubiquitination of GPX4, thereby stimulating ferroptosis in spermatocytes. Functionally, GPX4 deletion intensified ferroptosis and exacerbated DNA damage in GC-2 cells, while GPX4 overexpression mitigated ferroptosis induced by TP. Overall, these findings for the first time indicated a vital role of ferroptosis in TP induced-testicular injury and spermatogenic dysfunction through promoting GPX4 K63-linked polyubiquitination, which hopefully offers a potential therapeutic avenue for TP-related male reproductive damage. In addition, this study also provides a theoretical foundation for the improved clinical application of TP or TwHF in the future.

Fine particulate matter (PM2.5) induces testosterone disruption by triggering ferroptosis through SIRT1/HIF-1α signaling pathway in male mice

Fine particulate matter (PM2.5), a significant component of air pollution particulate matter, is inevitable and closely associated with increasing male reproductive disorder. However, the testicular targets of PM2.5 and its toxicity related molecular mechanisms are still not fully understood. In this study, the conditional knockout (cKO) mice and primary Leydig cells were used to explore the testicular targets of PM2.5 and the related underlying mechanisms. First, apparent the structure impairment of seminiferous tubules, Leydig cells vacuolization, decline of serum testosterone and sperm quality reduction were found in male wild-type (WT) and Sirt1 knockout mice after exposure to PM2.5. Enrichment analyses revealed that differentially expressed genes (DEGs) were enriched in steroid hormone biosynthesis, ferroptosis, and HIF-1 signaling pathway in the mice testes after exposure to PM2.5, which were subsequently verified by the molecular biological analyses. Notably, similar enrichment analyses results were also observed in primary Leydig cells after treatment with PM2.5. In addition, Knockdown of Sirt1 significantly increased PM2.5-induced expression and activation of HIF-1α, which was in parallel to the changes of cellular iron levels, oxidative stress indicators and the ferroptosis markers. In conclusion, this highlights that PM2.5 triggers ferroptosis via SIRT1/HIF-1α signaling pathway to inhibit testosterone synthesis in males. These findings provide a novel research support for the study that PM2.5 causes male reproductive injury.

Single-cell insights into mouse testicular toxicity under peripubertal exposure to di(2-ethylhexyl) phthalate

Male fertility depends on normal pubertal development. Di-(2-ethylhexyl) phthalate (DEHP) is a potent antiandrogen chemical, and exposure to DEHP during peripuberty can damage the developing male reproductive system, especially the testis. However, the specific cellular targets and differentiation processes affected by DEHP, which lead to testicular toxicity, remain poorly defined. Herein, we presented the first single-cell transcriptomic profile of the pubertal mouse testis following DEHP exposure. To carry out the experiment, 2 groups (n = 8 each) of 3-week-old male mice were orally administered 0.5% carboxymethylcellulose sodium salt or 100 mg/kg body weight DEHP daily from postnatal day 21-48, respectively. Using single-cell RNA sequencing, a total of 31 distinct cell populations were identified, notably, Sertoli and Leydig cells emerged as important targets of DEHP. DEHP exposure significantly decreased the proportions of Sertoli cell clusters expressing mature Sertoli markers (Sox9 and Ar), and selectively reduced the expression of testosterone synthesis genes in fetal Leydig cells. Through cell-cell interaction analyses, we observed changed numbers of interactions in Sertoli cells 1 (SCs1), Leydig cells 1 (LCs1), and interstitial macrophages, and we also identified cell-specific ligand gene expressions in these clusters, such as Inha, Fyn, Vcam1, and Apoe. Complementary in vitro assays confirmed that DEHP directly reduced the expression of genes related to Sertoli cell adhesion and intercellular communication. In conclusion, peripubertal DEHP exposure reduced the number of mature Sertoli cells and may disrupt testicular steroidogenesis by affecting the testosterone synthesis genes in fetal Leydig cells rather than adult Leydig cells.

Prenatal exposure to environmental phenols and phthalates and altered patterns of DNA methylation in childhood

INTRODUCTION

Epigenetic marks are key biomarkers linking the prenatal environment to health and development. However, DNA methylation associations and persistence of marks for prenatal exposure to multiple Endocrine Disrupting Chemicals (EDCs) in human populations have not been examined in great detail.

METHODS

We measured Bisphenol-A (BPA), triclosan, benzophenone-3 (BP3), methyl-paraben, propyl-paraben, and butyl-paraben, as well as 11 phthalate metabolites, in two pregnancy urine samples, at approximately 13 and 26 weeks of gestation in participants of the Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS) study (N = 309). DNA methylation of cord blood at birth and child peripheral blood at ages 9 and 14 years was measured with 450K and EPIC arrays. Robust linear regression was used to identify differentially methylated probes (DMPs), and comb-p was used to identify differentially methylated regions (DMRs) in association with pregnancy-averaged EDC concentrations. Quantile g-computation was used to assess associations of the whole phenol/phthalate mixture with DMPs and DMRs.

RESULTS

Prenatal BPA exposure was associated with 1 CpG among males and Parabens were associated with 10 CpGs among females at Bonferroni-level significance in cord blood. Other suggestive DMPs (unadjusted p-value < 1 × 10-6) and several DMRs associated with the individual phenols and whole mixture were also identified. A total of 10 CpG sites at least suggestively associated with BPA, Triclosan, BP3, Parabens, and the whole mixture in cord blood were found to persist into adolescence in peripheral blood.

CONCLUSIONS

We found sex-specific associations between prenatal phenol exposure and DNA methylation, particularly with BPA in males and Parabens in females. Additionally, we found several DMPs that maintained significant associations with prenatal EDC exposures at age 9 and age 14 years.

Hydrogen sulfide protects against toxicant acrolein-induced ferroptotic cell death in Sertoli cells

Acrolein (ACR) is a ubiquitous environmental pollutant and byproduct of lipid peroxidation that has been implicated in male infertility. However, the molecular mechanisms underlying ACR-induced toxicity in Sertoli cells remain unclear. Given its role in inducing oxidative stress, we examined whether ferroptosis, an iron-dependent form of regulated cell death, could mediate ACR toxicity in Sertoli cells. We also tested if hydrogen sulfide (H2S), which has antioxidant and ACR detoxifying properties, could protect Sertoli cells from ACR-induced ferroptosis. ACR exposure decreased Sertoli cell viability, increased protein carbonylation and p38 MAPK phosphorylation, indicating oxidative injury. ACR also depleted glutathione (GSH), downregulated the cystine importer SLC7A11, increased intracellular ferrous iron (Fe2+) and lipid peroxidation, suggesting activation of ferroptosis. Consistently, the ferroptosis inhibitor deferoxamine (DFO) markedly attenuates ACR-induced cell death. Further studies revealed that ACR-induced ferroptotic changes were prevented by exogenous H2S and exaggerated by inhibition of endogenous H2S production. Furthermore, H2S also suppressed GPX4 inhibitor RSL3-induced intracellular ACR accumulation and ferroptosis. In summary, our study demonstrates that ACR induces ferroptotic cell death in Sertoli cells, which can be prevented by H2S through multiple mechanisms. Targeting the H2S pathway may represent a therapeutic strategy to mitigate ACR-induced Sertoli cell injury and preserve 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.