Ferroptosis, autophagy, tumor and immunity

Mechanistic role of environmental toxicants in inducing cellular ferroptosis and its associated diseases

Due to exposure factors such as industrial exhaust, sewage discharge, pesticide runoff, automobile exhaust, and fuel combustion, environmental toxicants are widely present in daily life. Organisms are exposed to these environmental toxicants through contaminated air, food, and drinking water, and these environmental toxicants enter the human body and cause cytotoxicity and diseases through various pathways. As a new cell death mode that is different from cell necrosis, apoptosis, and autophagy, ferroptosis are mainly dysregulation of intracellular iron metabolism, lipid metabolism disorders, and the dysregulation of the antioxidant defense system, leading to lipid peroxidation and ultimately to the rupture of the cell membrane, damage, and cell death. Studies have shown that environmental toxicants induce a series of diseases, such as digestive diseases, urinary diseases, respiratory diseases, neurological disorders, and reproductive diseases, through the above mechanisms. We elaborate the mechanism of common environmental toxicants in inducing ferroptosis and the related systemic diseases mediated through the ferroptosis to provide the theoretical basis for preventing and treating environmental toxicant-related diseases. Nonetheless, our understanding of ferroptosis remains incomplete. For example, mechanisms and methods for the selective control of ferroptosis remain elusive, elucidating these mechanisms and strategies may be critical for leveraging knowledge of ferroptosis to treat related diseases.

Ferroptosis: A novel therapeutic target for diabetic cardiomyopathy

Ferroptosis is a new type of programmed cell death caused by the accumulation of iron-dependent lipid peroxides, and it plays a role in the occurrence and progression of diverse diseases. Diabetic cardiomyopathy (DCM), a serious cardiovascular complication in patients with diabetes, eventually progresses to refractory heart failure (HF), which increases the risk of hospitalization for HF and cardiovascular death in patients with diabetes. Despite glycemic control, effective strategies to prevent DCM onset are currently lacking. Accumulating evidence suggests that ferroptosis is involved in oxidative stress, inflammation, and abnormal autophagy in diabetic myocardium, which plays an important role in myocardial apoptosis, hypertrophy, and cardiac fibrosis. The inhibition of ferroptosis can relieve DCM. Presently, ferroptosis inhibitors have been broadly suggested for the treatment of iron overload-related cardiomyopathy. This article reviewed relevant studies to offer a new therapeutic target for DCM.

Integrated analysis of MIOX gene in prognosis of clear-cell renal cell carcinoma

Clear-cell renal cell carcinoma (ccRCC) is a highly aggressive malignancy that originates in the kidney. It often exhibits a limited response or can be refractory to a wide range of anti-cancer therapies, including tyrosine kinase inhibitors (TKIs) and immune checkpoint inhibitors. Ferroptosis is a form of oxidative, iron-dependent cell death characterized by lipid peroxidation. Targeting ferroptosis may offer a promising alternative therapeutic strategy for cancer cells that are resistant to existing treatments. The impact of ferroptosis-related genes on the prognosis of ccRCC patients is still not fully understood. In this study, we identified 30 differentially expressed ferroptosis-related genes in ccRCC samples compared to normal tissues using data from The Cancer Genome Atlas (TCGA). Lasso regression analyses, along with Kaplan-Meier analysis, were conducted to identify genes associated with prognosis. Based on scRNA-seq and spatial transcriptome analysis, we identified specificity of MIOX in ccRCC. Furthermore, MIOX demonstrated the highest significance, highlighting its independent prognostic value as a single gene in ccRCC. Our findings suggest that MIOX could serve as potential targets for therapeutic interventions in ccRCC.

Iron Metabolism and Ferroptosis in Diabetic Kidney Disease

Diabetic kidney disease (DKD) is a major diabetic microvascular complication that still lacks effective therapeutic drugs. Ferroptosis is a recently identified form of programmed cell death that is triggered by iron overload. It is characterized by unrestricted lipid peroxidation and subsequent membrane damage and is found in various diseases. Accumulating evidence has highlighted the crucial roles of iron overload and ferroptosis in DKD. Here, we review iron metabolism and the biology of ferroptosis. The role of aberrant ferroptosis in inducing diverse renal intrinsic cell death, oxidative stress, and renal fibrosis in DKD is summarized, and we elaborate on critical regulatory factors related to ferroptosis in DKD. Finally, we focused on the significance of ferroptosis in the treatment of DKD and highlight recent data regarding the novel activities of some drugs as ferroptosis inhibitors in DKD, aiming to provide new research targets and treatment strategies on DKD.

Targeted sonodynamic therapy induces tumor cell quasi-immunogenic ferroptosis and macrophage immunostimulatory autophagy in glioblastoma

In this study, we demonstrated the mechanism of a glioblastoma (GBM)-targeted sonodynamic therapy (SDT) strategy employing platelets loaded with a sonosensitizer based on functionalized boron nitride nanoparticles carrying chlorin e6 (BNPD-Ce6). In the in vitro study, we first found that the BNPD-Ce6-mediated sonodynamic action (SDA) induced remarkable viability loss, DNA damage, and cell death in the GBM cells (GBCs) but not macrophages. Surprisingly, the SDA-exposed GBCs displayed a ferroptotic phenotype while the SDA-exposed macrophages underwent immuno-stimulatory autophagy and potently potentiated the SDA's toxicity to the GBCs. The ferroptotic GBCs induced by the SDA were found to be quasi-immunogenic, characterized by the emission of some alarmins such as ATP, HSP90, and CRT, but absent HMGB1, a potent endogenous adjuvant. As such, the SDA-stressed GBCs were unable to stimulate the BMDMs. This defect, interestingly, could be rescued by platelets as a donor of HMGB1 which markedly enhanced the BNPD-Ce6's sonotoxicity to the GBCs. In the in vivo study, we first employed BNPD-Ce6-loaded platelets to achieve ultrasound-triggered, targeted delivery of BNPD-Ce6 in grafted intra-cranial GBMs and subsequent sonodynamic tumor damage. An SDT regimen designed based on these results slowed the growth of grafted intra-cranial GBMs and significantly increased the survival of the host animals. Pathological examination of the SDT-treated GBMs revealed tissue necrosis and destruction and validated the in vitro observations. Finally, the depletion of macrophages was found to abrogate the efficacy of the SDT in subcutaneous GBC grafts. In conclusion, the BNPD-Ce6@Plt-mediated SDT is a practicable and efficacious anti-GBM therapy. Its therapeutic mechanism critically involves a synergy of tumor cell ferroptosis, macrophage stimulation, and platelet activation induced by the SDA.

Research progress on ferroptosis in cerebral hemorrhage

The pathophysiology of intracerebral hemorrhage (ICH) is complex and can cause variable degrees of cell death. Recently, ferroptosis, an emerging cell death mechanism, has garnered significant attention in cerebral hemorrhage disorder. This study aimed to examine iron mortality after cerebral hemorrhage and current targets for potential therapeutic interventions. We specifically focused on iron metabolism abnormalities, lipid peroxidation, and related neuroinflammation and introduced molecular mechanisms, including transcription factors, to gain a better understanding of the underlying mechanisms of ferroptosis and investigate possible therapeutic options for ICH.

Ferroptosis in Pulmonary Disease and Lung Cancer: Molecular Mechanisms, Crosstalk Regulation, and Therapeutic Strategies

Ferroptosis is a distinct form of iron-dependent programmed cell death characterized primarily by intracellular iron accumulation and lipid peroxidation. Multiple cellular processes, including amino acid metabolism, iron metabolism, lipid metabolism, various signaling pathways, and autophagy, have been demonstrated to influence the induction and progression of ferroptosis. Recent investigations have elucidated that ferroptosis plays a crucial role in the pathogenesis of various pulmonary disorders, including lung injury, chronic obstructive pulmonary disease, pulmonary fibrosis, and asthma. Ferroptosis is increasingly recognized as a promising novel strategy for cancer treatment. Various immune cells within the tumor microenvironment, including CD8+ T cells, macrophages, regulatory T cells, natural killer cells, and dendritic cells, have been shown to induce ferroptosis in tumor cells and modulate the process through the regulation of iron and lipid metabolism pathways. Conversely, ferroptosis can reciprocally alter the metabolic environment, leading to the activation or inhibition of immune cell functions, thereby modulating immune responses. This paper reviews the molecular mechanism of ferroptosis and describes the tumor immune microenvironment, discusses the connection between ferroptosis and the tumor microenvironment in lung cancer and pulmonary diseases, and discusses the development prospect of their interaction in the treatment of lung cancer and pulmonary diseases.

Study of an N6-methyladenosine- and ferroptosis-related prognostic model and the mechanisms underlying the molecular network in neuroblastoma based on multiple datasets

Recent research highlights the pivotal role of N6-methyladenosine (m6A) modification and ferroptosis in the evolution of various cancers. This study aimed to establish a prognostic framework centered on genes associated with m6A and ferroptosis to enhance the accuracy of prognosis predictions for neuroblastoma (NB) patients, thereby improving targeted therapeutic strategies. Patient data, including expression profiles and clinical information from NB cases, were acquired from The Cancer Genome Atlas. Genes related to m6A modification and ferroptosis were identified, and those significant for prognosis were pinpointed using a combination of Cox regression analysis and the least absolute shrinkage and selection operator (LASSO) regression. For further validation, the study utilized external datasets GSE62564 and GSE85047. A prognostic index was computed for each NB patient, followed by analyses of immune cell infiltration and potential drug responsiveness based on the prognostic model. Additionally, enrichment analysis was conducted on the prognostic scores. These scores showed a strong association with the tumor immune environment and the efficacy of prevalent cancer therapies. Moreover, the model's prognostic score emerged as an independent predictive marker for NB. This research succeeded in creating and confirming a prognostic model rooted in m6A and ferroptosis-linked genes, promising to enrich the prognostic understanding and treatment approaches for NB.

Bergenin inhibits ferritinophagy and ferroptosis in cisplatin-induced acute kidney injury by activating the p-GSK3β/Nrf2/PPARγ pathway

Ferroptosis plays a key role in cisplatin-induced acute kidney injury (AKI). Bergenin, which is extracted from Ardisiae Japonicae Herba and has long been used in folk tea and herbal tea drinks, is known to activate Nrf2 and has anti-inflammatory and antioxidant properties, however, its protective influence on CI-AKI has not been elucidated. We used models of cisplatin-induced nephrotoxicity in vitro and CI-AKI models in vivo. In vitro, we found that ferroptosis and ferritinophagy biomarkers were strongly regulated by bergenin treatment. Mechanistic experiments demonstrated that bergenin bound to and phosphorylated GSK3β, which inhibited its activity, to promote the nuclear translocation of Nrf2 and its subsequent binding to the PPARγ promoter sequence to activate PPARγ. However, the protective effects of bergenin on ferroptosis and ferritinophagy in cisplatin-exposed HK-2 cells were diminished when Nrf2 or PPARγ was inhibited. In vivo, bergenin effectively inhibited renal damage induced by cisplatin. Furthermore, bergenin attenuated ferritinophagy-mediated ferroptosis caused by cisplatin; these effects were abolished in Nrf2 knockout mice. Our findings revealed that bergenin effectively protected against ferritinophagy and ferroptosis in CI-AKI, which was largely dependent on the activation of the p-GSK3β/Nrf2/PPARγ pathway.

A window into intracellular events in myositis through subcellular proteomics

OBJECTIVE AND DESIGN

Idiopathic inflammatory myopathies (IIM) are a heterogeneous group of inflammatory muscle disorders of unknown etiology. It is postulated that mitochondrial dysfunction and protein aggregation in skeletal muscle contribute to myofiber degeneration. However, molecular pathways that lead to protein aggregation in skeletal muscle are not well defined.

SUBJECTS

Here we have isolated membrane-bound organelles (e.g., nuclei, mitochondria, sarcoplasmic/endoplasmic reticulum, Golgi apparatus, and plasma membrane) from muscle biopsies of normal (n = 3) and muscle disease patients (n = 11). Of the myopathy group, 10 patients displayed mitochondrial abnormalities (IIM (n = 9); mitochondrial myopathy (n = 1)), and one IIM patient did not show mitochondrial abnormalities (polymyositis).

METHODS

Global proteomic analysis was performed using an Orbitrap Fusion mass spectrometer. Upon unsupervised clustering, normal and mitochondrial myopathy muscle samples clustered separately from IIM samples.

RESULTS

We have confirmed previously known protein alterations in IIM and identified several new ones. For example, we found differential expression of (i) nuclear proteins that control cell division, transcription, RNA regulation, and stability, (ii) ER and Golgi proteins involved in protein folding, degradation, and protein trafficking in the cytosol, and (iii) mitochondrial proteins involved in energy production/metabolism and alterations in cytoskeletal and contractile machinery of the muscle.

CONCLUSIONS

Our data demonstrates that molecular alterations are not limited to protein aggregations in the cytosol (inclusions) and occur in nuclear, mitochondrial, and membrane compartments of IIM skeletal muscle.

Broadening horizons: research on ferroptosis in lung cancer and its potential therapeutic targets

Ferroptosis is a novel form of cell death distinct from traditional mechanisms, characterized by the accumulation of iron ions and the production of lipid peroxides. It not only affects the survival of tumor cells but is also closely linked to changes in the tumor microenvironment. Lung cancer is one of the leading malignancies worldwide in terms of incidence and mortality, and its complex biological mechanisms and resistance make treatment challenging. Recent studies have shown that ferroptosis plays a key role in the onset and progression of lung cancer, with its intricate regulatory mechanisms influencing tumor development and response to therapy. As research into ferroptosis deepens, related molecular pathways, such as glutamate metabolism, iron metabolism, and antioxidant defense, have been gradually revealed. However, in clinical practice, ferroptosis-based therapeutic strategies for lung cancer are still in their early stages. Challenges remain, including the incomplete understanding of the specific mechanisms of ferroptosis, insufficient research on related regulatory factors, and limited insight into the interactions within the tumor microenvironment. Therefore, effective modulation of ferroptosis to enhance lung cancer treatment remains an urgent issue. This review summarizes the biological mechanisms of ferroptosis, analyzes the regulatory factors of ferroptosis in lung cancer cells and their interaction with the tumor microenvironment, and further explores potential therapeutic strategies targeting ferroptosis. By synthesizing the latest research, this paper aims to provide new perspectives and directions for lung cancer treatment, with the goal of advancing clinical applications.

Exploring the oncogenic role of RGS19 in bladder cancer progression and prognosis

This study investigates the role of autophagy-related genes (ARGs) in bladder cancer (BLCA), focusing on the regulator of G protein signaling 19 (RGS19). Using data from The Cancer Genome Atlas (TCGA) and the Human Autophagy Database (HADb), we identified RGS19 as significantly upregulated and linked to poor prognosis in BLCA. Kaplan-Meier survival analysis confirmed its association with increased mortality and. In vitro, RGS19 knockdown in BLCA cell lines inhibited proliferation, migration, and invasion, while inducing apoptosis and autophagy. Transmission electron microscopy showed autophagic structures in RGS19-silenced cells. In vivo, a xenograft mouse model demonstrated reduced tumor growth with RGS19 knockdown. Immunohistochemical (IHC) analysis revealed decreased Ki67 and increased autophagy markers in tumors with reduced RGS19. Pathway analysis suggested RGS19 acts through the cGMP-PKG signaling pathway, validated by altered expression of soluble guanylate cyclase (sGC), protein kinase G (PKG1), phosphodiesterase 5 A (PDE5A), vasodilator-stimulated phosphoprotein (VASP), and phosphorylated VASP (p-VASP) upon RGS19 knockdown. These results highlight RGS19 as a potential biomarker and therapeutic target in BLCA.

A crosstalk between autophagy and apoptosis in intracerebral hemorrhage

Intracerebral hemorrhage (ICH) is a severe condition that devastatingly harms human health and poses a financial burden on families and society. Bcl-2 Associated X-protein (Bax) and B-cell lymphoma 2 (Bcl-2) are two classic apoptotic markers post-ICH. Beclin 1 offers a competitive architecture with that of Bax, both playing a vital role in autophagy. However, the interaction between Beclin 1 and Bcl-2/Bax has not been conjunctively analyzed. This review aims to examine the crosstalk between autophagy and apoptosis in ICH by focusing on the interaction and balance of Beclin 1, Bax, and Bcl-2. We also explored the therapeutic potential of Western conventional medicine and traditional Chinese medicine (TCM) in ICH via controlling the crosstalk between autophagy and apoptosis.

Inhibition of CISD2 enhances sensitivity to doxorubicin in diffuse large B-cell lymphoma by regulating ferroptosis and ferritinophagy

Background

CDGSH iron-sulfur domain 2 (CISD2), an iron-sulfur protein with a [2Fe-2S] cluster, plays a pivotal role in the progression of various cancers, including Diffuse Large B-cell Lymphoma (DLBCL). However, the mechanisms by which CISD2 regulates the occurrence and development of DLBCL remain to be fully elucidated.

Methods

The potential role of CISD2 as a predictive marker in DLBCL patients treated with the R-CHOP regimen was investigated through bioinformatics analysis and clinical cohort studies. DLBCL cell lines (SUDHL-4 and HBL-1) were employed in this research. Adenoviral (AV) plasmids were used to either silence or overexpress CISD2 in these DLBCL cell lines. Additionally, the induction of ferroptosis in DLBCL cell lines was assessed. Various parameters, including cell proliferation, intracellular free iron levels, lipid peroxides, reactive oxygen species (ROS), and mitochondrial membrane potential (MMP), were measured. Furthermore, the expression of proteins associated with ferroptosis and ferritinophagy was analyzed. Drug-resistant DLBCL cell lines were developed by gradually increasing doxorubicin (DOX) concentration over 6 months. The biological role of CISD2 in these drug-resistant DLBCL cell lines was subsequently assessed.

Results

Elevated CISD2 levels were found to be associated with decreased sensitivity of DLBCL patients to the R-CHOP regimen, as indicated by bioinformatics and clinical cohort analysis. Silencing CISD2 significantly reduced cell proliferation, increased iron accumulation, depleted glutathione (GSH), and elevated malondialdehyde (MDA) levels, alongside the accumulation of ROS and increased MMP. Additionally, BECN1 and NCOA4 expressions were upregulated, while p62, FTH1, and GPX4 expressions were downregulated. Conversely, overexpression of CISD2 reversed these effects. Treatment of DLBCL cell lines with Erastin led to decreased CISD2 levels. Notably, in drug-resistant DLBCL cell lines, CISD2 knockdown promoted ferroptosis and ferritinophagy, restoring sensitivity to DOX and enhancing the efficacy of Erastin treatment.

Conclusion

Our findings suggest that CISD2 may play a role in the drug resistance observed in DLBCL patients. Inhibition of CISD2 could enhance ferroptosis and ferritinophagy, potentially improving the sensitivity of DLBCL cells to DOX treatment.

Chronic hypoxia drives the occurrence of ferroptosis in liver of fat greening (Hexagrammos otakii) by activating HIF-1α and promoting iron production

BACKGROUND

Hypoxia caused by global climate change and human activities has become a growing concern eliciting serious effect and damages to aquatic animals. Hexagrammos otakii is usually a victim of hypoxia which caused by high density aquaculture and high nutrient input. The mechanism underlying ferroptosis regulation after hypoxia-stress in liver of H. otakii, however, remains elusive.

METHODS

For a duration of 15 days, expose the H. otakii to low concentrations of dissolved oxygen (3.4 ± 0.2 mg/L). Detecting alterations in the H. otakii liver tissue by chemical staining, immunohistochemistry, and electron microscopy. The expression variations of relevant genes in the liver of the H. otakii were simultaneously detected using Western blot and qPCR. A correlation analysis was performed between HIF-1α and iron ion expression in the liver of H. otakii following hypoxic stress.

RESULTS

In this study, we conducted the whole ferroptosis integrated analysis of H. otakii under chronic hypoxic condition. Reactive oxygen species (ROS) are highly accumulated under the hypoxia treatment (Superoxide Dismutase, SOD; Catalase, CAT), and which results in a significantly enhanced of lipid peroxidation (Lipid Peroxidation, LPO; Malondialdehyde, MDA; Aminotransferase, AST; Alanine aminotransferase, ALT) in liver tissue. The HIF-1α signaling is activated to cope with the hypoxia stress through strategies including changing iron ion concentration (Fe3+ and TFR1) to breaking the oxidation balance (GSH and GSH-Px), and enhancing ferroptosis gene expression (GPX4). The expression of genes related to ferroptosis pathway (DMT1, FTH1, STEAP3, ACSL4, γ-GCS, SLC7A11) is significantly upregulated and associated to the expression of iron and HIF-1α.

CONCLUSIONS

It is demonstrated that the HIF-1α/Fe3+/ROS/GPX4 axis is involved in promoting ferroptosis in fat greening hepatocytes following hypoxia-stress. Ultimately, our findings unveil a process by which hypoxic stress strongly encourages ferroptosis by triggering HIF-1α and boosting iron synthesis.

Naringenin enhances the efficacy of ferroptosis inducers by attenuating aerobic glycolysis by activating the AMPK-PGC1α signalling axis in liver cancer

Liver cancer is a heterogeneous disease characterized by poor responses to standard therapies and therefore unfavourable clinical outcomes. Understanding the characteristics of liver cancer and developing novel therapeutic strategies are imperative. Ferroptosis, a type of programmed cell death induced by lipid peroxidation, has emerged as a potential target for treatment. Naringenin, a natural compound that modulates lipid metabolism by targeting AMPK, shows promise in enhancing the efficacy of ferroptosis inducers. In this study, we utilized liver cancer cell lines and xenograft mice to explore the synergistic effects of naringenin in combination with ferroptosis inducers, examining both phenotypic outcomes and molecular mechanisms. Our study results indicate that the use of naringenin at non-toxic doses to hepatocytes can significantly enhance the anticancer effects of ferroptosis inducers (erastin, RSL3, and sorafenib). The combination index method confirmed a synergistic effect between naringenin and ferroptosis inducers. In comparison to naringenin or ferroptosis inducers alone, the combined therapy caused more robust lipid peroxidation and hence more severe ferroptotic damage to cancer cells. The inhibition of aerobic glycolysis mediated by the AMPK-PGC1α signalling axis is the key to naringenin's effect on reducing ferroptosis resistance in liver cancer, and the synergistic cytotoxic effect of naringenin and ferroptosis inducers on cancer cells was reversed after pretreatment with an AMPK inhibitor or a PGC1α inhibitor. Taken together, these findings suggest that naringenin could boost cancer cell sensitivity to ferroptosis inducers, which has potential clinical translational value.

Autophagy flux in bladder cancer: Cell death crosstalk, drug and nanotherapeutics

Autophagy, a self-digestion mechanism, has emerged as a promising target in the realm of cancer therapy, particularly in bladder cancer (BCa), a urological malignancy characterized by dysregulated biological processes contributing to its progression. This highly conserved catabolic mechanism exhibits aberrant activation in pathological events, prominently featured in human cancers. The nuanced role of autophagy in cancer has been unveiled as a double-edged sword, capable of functioning as both a pro-survival and pro-death mechanism in a context-dependent manner. In BCa, dysregulation of autophagy intertwines with cell death mechanisms, wherein pro-survival autophagy impedes apoptosis and ferroptosis, while pro-death autophagy diminishes tumor cell survival. The impact of autophagy on BCa progression is multifaceted, influencing metastasis rates and engaging with the epithelial-mesenchymal transition (EMT) mechanism. Pharmacological modulation of autophagy emerges as a viable strategy to impede BCa progression and augment cell death. Notably, the introduction of nanoparticles for targeted autophagy regulation holds promise as an innovative approach in BCa suppression. This review underscores the intricate interplay of autophagy with cell death pathways and its therapeutic implications in the nuanced landscape of bladder cancer.