NUPR1 is a critical repressor of ferroptosis

NOX4 exacerbates Parkinson's disease pathology by promoting neuronal ferroptosis and neuroinflammation

JOURNAL/nrgr/04.03/01300535-202507000-00026/figure1/v/2024-09-09T124005Z/r/image-tiff Parkinson's disease is primarily caused by the loss of dopaminergic neurons in the substantia nigra compacta. Ferroptosis, a novel form of regulated cell death characterized by iron accumulation and lipid peroxidation, plays a vital role in the death of dopaminergic neurons. However, the molecular mechanisms underlying ferroptosis in dopaminergic neurons have not yet been completely elucidated. NADPH oxidase 4 is related to oxidative stress, however, whether it regulates dopaminergic neuronal ferroptosis remains unknown. The aim of this study was to determine whether NADPH oxidase 4 is involved in dopaminergic neuronal ferroptosis, and if so, by what mechanism. We found that the transcriptional regulator activating transcription factor 3 increased NADPH oxidase 4 expression in dopaminergic neurons and astrocytes in an 1-methyl-4-phenyl-1,2,3,6 tetrahydropyridine-induced Parkinson's disease model. NADPH oxidase 4 inhibition improved the behavioral impairments observed in the Parkinson's disease model animals and reduced the death of dopaminergic neurons. Moreover, NADPH oxidase 4 inhibition reduced lipid peroxidation and iron accumulation in the substantia nigra of the Parkinson's disease model animals. Mechanistically, we found that NADPH oxidase 4 interacted with activated protein kinase C α to prevent ferroptosis of dopaminergic neurons. Furthermore, by lowering the astrocytic lipocalin-2 expression, NADPH oxidase 4 inhibition reduced 1-methyl-4-phenyl-1,2,3,6 tetrahydropyridine-induced neuroinflammation. These findings demonstrate that NADPH oxidase 4 promotes ferroptosis of dopaminergic neurons and neuroinflammation, which contribute to dopaminergic neuron death, suggesting that NADPH oxidase 4 is a possible therapeutic target for Parkinson's disease.

Ferroptosis: when metabolism meets cell death

We present here a comprehensive update on recent advancements in the field of ferroptosis, with a particular emphasis on its metabolic underpinnings and physiological impacts. After briefly introducing landmark studies that have helped to shape the concept of ferroptosis as a distinct form of cell death, we critically evaluate the key metabolic determinants involved in its regulation. These include the metabolism of essential trace elements such as selenium and iron; amino acids such as cyst(e)ine, methionine, glutamine/glutamate, and tryptophan; and carbohydrates, covering glycolysis, the citric acid cycle, the electron transport chain, and the pentose phosphate pathway. We also delve into the mevalonate pathway and subsequent cholesterol biosynthesis, including intermediate metabolites like dimethylallyl pyrophosphate, squalene, coenzyme Q (CoQ), vitamin K, and 7-dehydrocholesterol, as well as fatty acid and phospholipid metabolism, including the biosynthesis and remodeling of ester and ether phospholipids and lipid peroxidation. Next, we highlight major ferroptosis surveillance systems, specifically the cyst(e)ine/glutathione/glutathione peroxidase 4 axis, the NAD(P)H/ferroptosis suppressor protein 1/CoQ/vitamin K system, and the guanosine triphosphate cyclohydrolase 1/tetrahydrobiopterin/dihydrofolate reductase axis. We also discuss other potential anti- and proferroptotic systems, including glutathione S-transferase P1, peroxiredoxin 6, dihydroorotate dehydrogenase, glycerol-3-phosphate dehydrogenase 2, vitamin K epoxide reductase complex subunit 1 like 1, nitric oxide, and acyl-CoA synthetase long-chain family member 4. Finally, we explore ferroptosis's physiological roles in aging, tumor suppression, and infection control, its pathological implications in tissue ischemia-reperfusion injury and neurodegeneration, and its potential therapeutic applications in cancer treatment. Existing drugs and compounds that may regulate ferroptosis in vivo are enumerated.

Targeting ferroptosis in gastrointestinal tumors: Interplay of iron-dependent cell death and autophagy

Ferroptosis is a regulated cell death mechanism distinct from apoptosis, autophagy, and necroptosis, marked by iron accumulation and lipid peroxidation. Since its identification in 2012, it has developed into a potential therapeutic target, especially concerning GI disorders like PC, HCC, GC, and CRC. This interest arises from the distinctive role of ferroptosis in the progression of diseases, presenting a new avenue for treatment where existing therapies fall short. Recent studies emphasize the promise of focusing on ferroptosis to fight GI cancers, showcasing its unique pathophysiological mechanisms compared to other types of cell death. By comprehending how ferroptosis aids in the onset and advancement of GI diseases, scientists aim to discover novel drug targets and treatment approaches. Investigating ferroptosis in gastrointestinal disorders reveals exciting possibilities for novel therapies, potentially revolutionizing cancer treatment and providing renewed hope for individuals affected by these tumors.

Identifying potential genes driving ferroptosis in the substantia nigra and dopaminergic neurons in Parkinson's disease

Parkinson's disease (PD) is a neurodegenerative disorder marked by dopaminergic (DA) neuron degeneration in the substantia nigra (SN). Conventional dopamine replacement therapies provide limited long-term efficacy and significant side effects. Emerging evidence suggests ferroptosis-a form of cell death driven by iron-dependent lipid peroxidation-contributes to PD pathology, though direct evidence linking dysregulation of ferroptosis-related genes in DA neuron loss in PD remains limited. This study explores the expression of ferroptosis-associated genes in the SN and DA neurons of PD patients, identifying potential therapeutic targets. We analyzed two independent RNA-seq datasets, GSE7621 and GSE8397 (GPL-96), from the GEO database to identify common differentially expressed ferroptosis-related genes in the SN of PD patients. We also conducted Gene Ontology and pathway enrichment analyses of these genes to explore the underlying mechanisms and constructed a protein-protein interaction network. The findings were further validated using an additional dataset, GSE49036. We further explored the dysregulation of these ferroptosis-related genes in DA neurons using RNA-seq data GSE169755, derived from DA neurons isolated from the SN of PD patients and controls. Lastly, the proposed hypothesis was experimentally validated in an in vitro PD model. This comprehensive multi-dataset analysis uncovers novel insights into the expression of ferroptosis-related genes in PD, suggesting potential biomarkers and therapeutic targets for mitigating DA neuron loss and PD progression.

Dissecting the cell microenvironment of ovarian endometrioma through single-cell RNA sequencing

Ovarian endometrioma (OE), also known as "chocolate cysts," is a cystic mass that develops in the ovaries due to endometriosis and is a common gynecological condition characterized by the growth of endometrial tissue outside the uterus, leading to symptoms such as dysmenorrhea, pelvic pain, and infertility. However, the precise molecular and cellular mechanisms driving this pathophysiology remain largely unknown, posing challenges for diagnosis and treatment. Here, we employed integrated single-cell transcriptomic profiling of over 52,000 individual cells from endometrial tissues of OE patients and healthy donors and identified twelve major cell populations. We identified notable alterations in cell type-specific proportions and molecular signatures associated with OE. Notably, the activation of IGFBP5+ macrophages with pro-inflammatory properties, NK cell exhaustion, and aberrant proliferation of IQCG+ and KLF2+ epithelium are key features and may be the potential mechanisms underlying the pathogenesis of OE. Collectively, our data contribute to a better understanding of OE at the single cell level and may pave the way for the development of novel therapeutic strategies.

Ageing limits stemness and tumorigenesis by reprogramming iron homeostasis

Ageing is associated with a decline in the number and fitness of adult stem cells1,2. Ageing-associated loss of stemness is posited to suppress tumorigenesis3,4, but this hypothesis has not been tested in vivo. Here we use physiologically aged autochthonous genetically engineered5,6 mouse models and primary cells5,6 to demonstrate that ageing suppresses lung cancer initiation and progression by degrading the stemness of the alveolar cell of origin. This phenotype is underpinned by the ageing-associated induction of the transcription factor NUPR1 and its downstream target lipocalin-2 in the cell of origin in mice and humans, which leads to functional iron insufficiency in the aged cells. Genetic inactivation of the NUPR1-lipocalin-2 axis or iron supplementation rescues stemness and promotes the tumorigenic potential of aged alveolar cells. Conversely, targeting the NUPR1-lipocalin-2 axis is detrimental to young alveolar cells through ferroptosis induction. Ageing-associated DNA hypomethylation at specific enhancer sites is associated with increased NUPR1 expression, which is recapitulated in young alveolar cells through DNA methylation inhibition. We uncover that ageing drives functional iron insufficiency that leads to loss of stemness and tumorigenesis but promotes resistance to ferroptosis. These findings have implications for the therapeutic modulation of cellular iron homeostasis in regenerative medicine and in cancer prevention. Furthermore, our findings are consistent with a model whereby most human cancers initiate at a young age, thereby highlighting the importance of directing cancer prevention efforts towards young individuals.

Macropinocytosis inhibits alkaliptosis in pancreatic cancer cells through fatty acid uptake

Alkaliptosis, a form of regulated cell death, is characterized by lysosomal dysfunction and intracellular pH alkalinization. The pharmacological induction of alkaliptosis using the small molecule compound JTC801 has emerged as a promising anticancer strategy in various types of cancers, particularly pancreatic ductal adenocarcinoma (PDAC). In this study, we investigate a novel mechanism by which macropinocytosis, an endocytic process involving the uptake of extracellular material, promotes resistance to alkaliptosis in human PDAC cells. Through lipid metabolomics analysis and functional studies, we demonstrate that the inhibition of alkaliptosis by fatty acids, such as oleic acid, is not dependent on endogenous synthetic pathways but rather on exogenous uptake facilitated by macropinocytosis. Consequently, targeting macropinocytosis through pharmacological approaches (e.g. using EIPA or EHoP-016) or genetic interventions (e.g. RAC1 knockdown) effectively enhances JTC801-induced alkaliptosis in human PDAC cells. These findings provide compelling evidence that the modulation of macropinocytosis can increase the sensitivity of cancer cells to alkaliptosis inducers.

Emerging insights into the role of microRNAs regulation of ferroptosis in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a major type of liver cancer and an important cause of cancer death. It has been reported that the hepatocyte death plays an important role in HCC. Ferroptosis is an iron-dependent programmed cell death characterized by the accumulation of free iron and lipid peroxidation. A series of studies have shown that ferroptosis contributes to the occurrence and development of HCC. MicroRNAs (miRNAs) are non-coding RNAs with a length of approximately 21-22 nt. In recent years, miRNAs have been shown to participate in regulating ferroptosis to play a vital role in HCC, but the related mechanisms are not fully understood. This review summarized the current understanding of ferroptosis, as well as the biogenesis and function of miRNAs, and focused on the role of miRNAs regulation of ferroptosis in HCC, with the hope of providing new targets and ideas for the treatment of HCC.

[Knockdown of nuclear protein 1 delays pathological pro-gression of osteoarthritis through inhibiting chondrocyte ferroptosis]

OBJECTIVES

To investigate the effect of nuclear protein (Nupr) 1 on the pathological progression of osteoarthritis and its relationship with ferroptosis of chondrocytes.

METHODS

Chondrocytes from mouse knees were divided into small interfering RNA (siRNA) control group, small interfering RNA targeting Nupr1 (siNupr1) group, siRNA control+IL-1β group (siRNA control interference for 24 h followed by 10 ng/mL IL-1β) and siNupr1+IL-1β group (siNupr1 interference for 24 h followed by 10 ng/mL IL-1β). The protein and mRNA expressions of Nupr1 were detected by Western blotting and quantitative reverse transcription polymerase chain reaction (qRT-PCR). Cell proliferation viabilities were measured using the cell counting kit-8 method. The levels of ferrous ions were detected by FerroOrange staining. Lipid peroxidation levels were detected by C11-BODIPY-591 fluorescence imaging. The contents of malondialdehyde (MDA) and glutathione (GSH) were detected by enzyme-linked immunosorbent assay. The protein expressions of acyl-CoA synthetase long-chain family (ACSL) 4, P53, glutathione peroxidase (GPX) 4 and solute carrier family 7 member 11 gene (SLC7A11) were detected by Western blotting. The osteoarthritis model was constructed by destabilization of the medial meniscus (DMM) surgery in 7-week-old male C57BL/6J mice. The mice were randomly divided into four groups with 10 animals in each group: sham surgery (Sham)+adeno-associated virus serotype 5 (AAV5)-short hairpin RNA (shRNA) control group, Sham+AAV5-shRNA control targeting Nupr1 (shNupr1) group, DMM+AAV5-shRNA control group, and DMM+AAV5-shNupr1 group. Hematoxylin and eosin staining and Safranin O-Fast Green staining were used to observe the morphological changes in cartilage tissue. The Osteoarthritis Research Society International (OARSI) osteoarthritis cartilage histopathology assessment system was used to evaluate the degree of cartilage degeneration in mice. The mRNA expressions of matrix metallopeptidase (MMP) 13, a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS) 5, cyclooxy-genase (COX) 2, and GPX4 were detected by qRT-PCR.

RESULTS

In vitro experiments showed that knocking down Nupr1 alleviated the decrease of chondrocyte proliferation activity induced by IL-1β, reduced iron accumulation in mouse chondrocytes, lowered lipid peroxidation, downregulated ACSL4 and P53 protein expression and upregulated GPX4 and SLC7A11 protein expression (all P<0.01), thereby inhibiting ferroptosis in mouse chondrocytes. Meanwhile, in vivo animal experiments demonstrated that knocking down Nupr1 delayed the degeneration of articular cartilage in osteoarthritis mice, improved the OARSI score, slowed down the degradation of the extracellular matrix in osteoarthritis cartilage, and reduced the expression of the key ferroptosis regulator GPX4 (all P<0.01).

CONCLUSIONS

Knockdown of Nupr1 can delay the pathological progression of osteoarthritis through inhibiting ferroptosis in mouse chondrocytes.

SRC kinase drives multidrug resistance induced by KRAS-G12C inhibition

Direct targeting of the KRAS-G12C-mutant protein using covalent inhibitors (G12Ci) acts on human non-small cell lung cancer (NSCLC). However, drug resistance is an emerging concern in this approach. Here, we show that MRTX849, a covalent inhibitor targeting the KRAS-G12C mutation, leads to the reactivation of the mitogen-activated protein kinase signaling pathway in MRTX849-resistant NSCLC and pancreatic ductal adenocarcinoma. A genome-wide CRISPR screen revealed that the adenosine triphosphate binding cassette transporter ABCC1 mediates MRTX849 resistance. Functional studies demonstrated that the transcription factor JUN drives ABCC1 expression, resulting in multidrug resistance. An unbiased drug screen identified the tyrosine kinase inhibitor dasatinib that potentiates MRTX849 efficacy by inhibiting SRC-dependent JUN activation, avoiding multidrug resistance and tumor suppression in vitro as well as in suitable preclinical mouse models and patient-derived organoids. SRC inhibitors (DGY-06-116, dasatinib, and bosutinib) also exhibit synergistic effects with MRTX849 in eliminating various tumor cell lines carrying KRAS-G12C mutations. Thus, SRC inhibitors amplify the therapeutic utility of G12Ci.

The Emerging Scenario of Ferroptosis in Pancreatic Cancer Tumorigenesis and Treatment

Pancreatic cancer remains one of the most lethal forms of cancer. Currently, there is a lack of effective drug treatments for pancreatic cancer. However, as a newly discovered form of non-apoptotic cell death, ferroptosis has garnered increasing attention in relation to pancreatic cancer. Understanding the role of ferroptosis in the tumorigenesis and treatment of pancreatic cancer may enable more effective clinical trials and treatments for pancreatic cancer and may minimize side effects or restrict the emergence of drug resistance. In this review, we summarize the current knowledge regarding the process and underlying mechanisms of ferroptosis, as well as its dual role in both promoting tumorigenesis and facilitating treatment strategies for pancreatic cancer. Additionally, how ferroptosis is implicated in the development of pancreatitis and insulin resistance, indicating that ferroptosis may play an important role in the risk of pancreatitis- and insulin-resistance-related pancreatic cancers, is also addressed.

The role of ferroptosis-related non-coding RNA in liver fibrosis

Liver fibrosis represents a reversible pathophysiological process, caused by chronic inflammation stemming from hepatocyte damage. It delineates the initial stage in the progression of chronic liver disease. This pathological progression is characterized by the excessive accumulation of the extracellular matrix (ECM), which leads to significant structural disruption and ultimately impairs liver function. To date, no specific antifibrotic drugs have been developed, and advanced liver fibrosis remains largely incurable. Liver transplantation remains the sole efficacious intervention for advanced liver fibrosis; nevertheless, it is constrained by exorbitant costs and the risk of postoperative immune rejection, underscoring the imperative for novel therapeutic strategies. Ferroptosis, an emergent form of regulated cell death, has been identified as a pivotal regulatory mechanism in the development of liver fibrosis and is intricately linked with the progression of liver diseases. Recent investigations have elucidated that a diverse array of non-coding RNAs (ncRNAs), including microRNAs, long non-coding RNAs, and circular RNAs, are involved in the ferroptosis pathway, thereby modulating the progression of various diseases, including liver fibrosis. In recent years, the roles of ferroptosis and ferroptosis-related ncRNAs in liver fibrosis have attracted escalating scholarly attention. This paper elucidates the pathophysiology of liver fibrosis, explores the mechanisms underlying ferroptosis, and delineates the involvement of ncRNA-mediated ferroptosis pathways in the pathology of liver fibrosis. It aims to propose novel strategies for the prevention and therapeutic intervention of liver fibrosis.

Lipocalin-2 promotes CKD vascular calcification by aggravating VSMCs ferroptosis through NCOA4/FTH1-mediated ferritinophagy

Vascular calcification (VC) is a common complication of chronic kidney disease (CKD), for which no effective therapies are available. Hyperphosphatemia, a feature of CKD, is a well-known inducer of VC. High phosphate (HP)-induced ferroptosis plays a crucial role in CKD-related VC (CKD-VC), but the mechanisms remain unclear. Lipocalin-2 (LCN2), an iron-trafficking protein, has been implicated in ferroptosis regulation. In the present study, the role of LCN2 as a potential mediator of CKD-VC was investigated. HP-induced LCN2 expression in the arteries of CKD-VC patients, animal models and vascular smooth muscle cells (VSMCs). LCN2 knockout (LCN2KO) mice and wild-type (WT) mice fed with a high adenine and phosphate (AP) diet were studied to explore CKD-VC. Compared with WT mice, LCN2KO mice showed an amelioration of the CKD-VC induced by the AP diet. The inhibition of LCN2 also alleviated HP-induced calcium deposition and phenotypic transition in VSMCs. Conversely, VSMCs-targeted LCN2 overexpression or recombinant LCN2 treatment exacerbated CKD-VC in vivo and in vitro. Mechanistically, nuclear receptor coactivator 4 (NCOA4)/ferritin heavy chain 1 (FTH1)-mediated ferritinophagy-dependent ferroptosis was involved in LCN2-mediated CKD-VC. Under HP conditions, LCN2 interacted with NCOA4, potentially accelerating the degradation of FTH1 and inducing ferroptosis. The inhibition of LCN2 may rescue the degradation of FTH1 and thus ameliorate ferroptosis, significantly suppressing VSMCs calcification. In summary, our study revealed a novel role for LCN2 induced ferritinophagy-dependent ferroptosis in CKD-VC, and targeting LCN2 might be a promising treatment for CKD-VC.

Development of an efficient NUPR1 inhibitor with anticancer activity

Pancreatic cancer is highly lethal and has limited treatment options available. Our team had previously developed ZZW-115, a promising drug candidate that targets the nuclear protein 1 (NUPR1), which is involved in pancreatic cancer development and progression. However, clinical translation of ZZW-115 was hindered due to potential cardiotoxicity caused by its interaction with the human Ether-à-go-go-Related Gene (hERG) potassium channel. To address this, we have performed a high-throughput screening of 10,000 compounds from the HitFinder Chemical Library, and identified AJO14 as a lead compound that binds to NUPR1, without having favorable affinity towards hERG. AJO14 induced cell death through apoptosis, necroptosis, and parthanatos (induced by the poly-ADP ribose polymerase (PARP) overactivation), driven by mitochondrial catastrophe and decreased ATP production. This process seemed to be mediated by the hyperPARylation (an excessive modification of proteins by PARP, leading to cellular dysfunction), as it could be reversed by Olaparib, a PARP inhibitor. In xenografted mice, AJO14 demonstrated a dose-dependent tumor reduction activity. Furthermore, we attempted to improve the anti-cancer properties of AJO14 by molecular modification of the lead compound. Among the 51 candidates obtained and tested, 8 compounds exhibited a significant increase in efficacy and have been retained for further studies, especially LZX-2-73. These AJO14-derived compounds offer potent NUPR1 inhibition for pancreatic cancer treatment, without cardiotoxicity concerns.

Targeted animal models for preclinical assessment of cellular and gene therapies in pancreatic and liver diseases: regulatory and practical insights

Cellular and gene therapy (CGT) products have emerged as a popular approach in regenerative medicine, showing promise in treating various pancreatic and liver diseases in numerous clinical trials. Before these therapies can be tested in human clinical trials, it is essential to evaluate their safety and efficacy in relevant animal models. Such preclinical testing is often required to obtain regulatory approval for investigational new drugs. However, there is a lack of detailed guidance on selecting appropriate animal models for CGT therapies targeting specific pancreatic and liver conditions, such as pancreatitis and chronic liver diseases. In this review, the gastrointestinal committee for the International Society for Cell and Gene Therapy provides a summary of current recommendations for animal species and disease model selection, as outlined by the US Food and Drug Administration, with references to EU EMA and Japan PMDA. We discuss a range of small and large animal models, as well as humanized models, that are suitable for preclinical testing of CGT products aimed at treating pancreatic and liver diseases. For each model, we cover the associated pathophysiology, commonly used metrics for assessing disease status, the pros and limitations of the models, and the relevance of these models to human conditions. We also summarize the use and application of humanized mouse and other animal models in evaluating the safety and efficacy of CGT products. This review aims to provide comprehensive guidance for selecting appropriate animal species and models to help bridge the gap between the preclinical research and clinical trials using CGT therapies for specific pancreatic and liver diseases.

NUPR1 modulates pulmonary embolism progression via smooth muscle cells phenotypic transformation

Objective

This study aimed to investigate the role of Nuclear Protein 1 (NUPR1) in pulmonary embolism (PE) and its impact on the phenotypic transformation of pulmonary artery smooth muscle cells (PASMCs).

Methods

A PE model was established via autologous pulmonary emboli infusion into the jugular vein. Partial Pressure of Oxygen (PaO2), Oxygenation Index (OI), Brain Natriuretic Peptide (BNP), and Troponin I (TnI) were measured, and lung tissue was subjected to hematoxylin-eosin (HE) staining. NUPR1 expression was assessed through Immunofluorescence and Western blot analyses. To investigate role of NUPR1, PE rats were treated with lentiviral vectors for NUPR1 knockdown (si-NUPR1) or overexpression (ov-NUPR1), and the effects on lung pathology were examined. NUPR1 expression was evaluated in human PASMCs. Additionally, PASMCs from SD rats were cultured under normoxic and hypoxic conditions to evaluate NUPR1 expression. Transfection of NUPR1 expression vectors into PASMCs allowed monitoring of phenotypic transformation-associated protein changes and PASMCs activity.

Results

Increased NURP1 was observed in human-derived PASMCs. In PE rats, histological examination revealed ruptured pulmonary alveoli, exudate accumulation, interstitial edema, and infiltration of inflammatory cells, concomitant with elevated NUPR1 expression levels. Knockdown of NUPR1 in PE rats significantly improved lung tissue structure, reducing alveolar rupture and interstitial edema. Conversely, NUPR1 overexpression exacerbated lung damage, leading to increased inflammatory infiltration. NUPR1 expression in rat PASMCs remained stable under normoxic conditions; however, under hypoxic conditions, NUPR1 protein expression increased progressively over time. Subsequent upregulation of NUPR1 expression led to a decrease in the levels of contractile phenotype markers α-SMA and SM22α in PASMCs, accompanied by increased expression of synthetic phenotype markers Vimentin and OPN. This phenotypic shift was associated with enhanced cellular proliferation, invasion, and migration.

Conclusions

Elevated NUPR1 expression in PE exacerbates abnormal PASMCs proliferation by promoting their phenotypic transformation, thereby fostering the pathological progression of PE.

Resistance to FOXM1 inhibitors in breast cancer is accompanied by impeding ferroptosis and apoptotic cell death

PURPOSE

Cancer treatments often become ineffective because of acquired drug resistance. To characterize changes in breast cancer cells accompanying development of resistance to inhibitors of the oncogenic transcription factor, FOXM1, we investigated the suppression of cell death pathways, especially ferroptosis, in FOXM1 inhibitor-resistant cells. We also explored whether ferroptosis activators can synergize with FOXM1 inhibitors and can overcome FOXM1 inhibitor resistance.

METHODS

In estrogen receptor-positive and triple-negative breast cancer cells treated with FOXM1 inhibitor NB73 and ferroptosis activators dihydroartemisinin and JKE1674, alone and in combination, we measured suppression of cell viability, motility, and colony formation, and monitored changes in gene and protein pathway expressions and mitochondrial integrity.

RESULTS

Growth suppression of breast cancer cells by FOXM1 inhibitors is accompanied by increased cell death and alterations in mitochondrial morphology and metabolic activity. Low doses of FOXM1 inhibitor strongly synergize with ferroptosis inducers to reduce cell viability, migration, colony formation, and expression of proliferation-related genes, and increase intracellular Fe+2 and lipid peroxidation, markers of ferroptosis. Acquired resistance to FOXM1 inhibition is associated with increased expression of cancer stem-cell markers and proteins that repress ferroptosis, enabling cell survival and drug resistance. Notably, resistant cells are still sensitive to growth suppression by low doses of ferroptosis activators, effectively overcoming the acquired resistance.

CONCLUSION

Delineating changes in viability and cell death pathways that can overcome drug resistance should be helpful in determining approaches that might best prevent or reverse resistance to therapeutic targeting of FOXM1 and ultimately improve patient clinical outcomes.

Overexpression of NUDT16L1 sustains proper function of mitochondria and leads to ferroptosis insensitivity in colorectal cancer

Cancer research is continuously exploring new avenues to improve treatments, and ferroptosis induction has emerged as a promising approach. However, the lack of comprehensive analysis of the ferroptosis sensitivity in different cancer types has limited its clinical application. Moreover, identifying the key regulator that influences the ferroptosis sensitivity during cancer progression remains a major challenge. In this study, we shed light on the role of ferroptosis in colorectal cancer and identified a novel ferroptosis repressor, NUDT16L1, that contributes to the ferroptosis insensitivity in this cancer type. Mechanistically, NUDT16L1 promotes ferroptosis insensitivity in colon cancer by enhancing the expression of key ferroptosis repressor and mitochondrial genes through direct binding to NAD-capped RNAs and the indirect action of MALAT1. Our findings also reveal that NUDT16L1 localizes to the mitochondria to maintain its proper function by preventing mitochondrial DNA leakage after treatment of ferroptosis inducer in colon cancer cells. Importantly, our orthotopic injection and Nudt16l1 transgenic mouse models of colon cancer demonstrated the critical role of NUDT16L1 in promoting tumor growth. Moreover, clinical specimens revealed that NUDT16L1 was overexpressed in colorectal cancer, indicating its potential as a therapeutic target. Finally, our study shows the therapeutic potential of a NUDT16L1 inhibitor in vitro, in vivo and ex vivo. Taken together, these findings provide new insights into the crucial role of NUDT16L1 in colorectal cancer and highlight its potential as a promising therapeutic target.

ATF4/NUPR1 axis promotes cancer cell survival and mediates immunosuppression in clear cell renal cell carcinoma

Cancer cells encounter unavoidable stress during tumor growth. The stress-induced transcription factor, activating transcription factor 4 (ATF4), has been reported to upregulate various adaptive genes involved in salvage pathways to alleviate stress and promote tumor progression. However, this effect is unknown in clear cell renal cell carcinoma (ccRCC). In this study, we found that ATF4 expression was remarkably upregulated in tumor tissues and associated with poor ccRCC outcomes. ATF4 depletion significantly impaired ccRCC cell proliferation, migration, and invasion in vitro and in vivo by inhibiting the AKT/mTOR and epithelial-mesenchymal transition (EMT)-related signaling pathway. RNA sequencing and functional studies identified nuclear protein 1 (NUPR1) as a key downstream target of ATF4 for repressing ferroptosis and promoting ccRCC cell survival. In addition, targeting ATF4 or pharmacological inhibition using NUPR1 inhibitor ZZW115 promoted antitumor immunity in syngeneic graft mouse models, represented by increased infiltration of CD4+ and CD8+ T cells. Furthermore, ZZW115 could improve the response to the PD-1 immune checkpoint blockade. The results demonstrate that the ATF4/NUPR1 signaling axis promotes ccRCC survival and facilitates tumor-mediated immunosuppression, providing a set of potential targets and prognostic indicators for ccRCC patients.

Regulation of renal ischemia-reperfusion injury and tubular epithelial cell ferroptosis by pparγ m6a methylation: mechanisms and therapeutic implications

This study aimed to elucidate the role and underlying mechanisms of Peroxisome proliferator-activated receptor gamma (PPARγ) and its m6A methylation in renal ischemia-reperfusion (I/R) injury and ferroptosis of tubular epithelial cells (TECs). High-throughput transcriptome sequencing was performed on renal tissue samples from I/R injury models and sham-operated mice, complemented by in vivo and in vitro experiments focusing on the PPARγ activator Rosiglitazone and the manipulation of METTL14 and IGF2BP2 expression. Key evaluations included renal injury assessment, ferroptosis indicator measurement, and m6A methylation analysis of PPARγ. Our findings highlight the critical role of the PPARγ pathway and ferroptosis in renal I/R injury, with Rosiglitazone ameliorating renal damage and TEC ferroptosis. METTL14-mediated m6A methylation of PPARγ, dependent on IGF2BP2, emerged as a pivotal regulator of PPARγ expression, renal injury, and ferroptosis. This study reveals that PPARγ m6A methylation, orchestrated by METTL14 through an IGF2BP2-dependent mechanism, plays a crucial role in mitigating renal I/R injury and TEC ferroptosis. These insights offer promising avenues for therapeutic strategies targeting acute kidney injury.

Deciphering the Landscape of GATA-Mediated Transcriptional Regulation in Gastric Cancer

Gastric cancer (GC) is an asymptomatic malignancy in early stages, with an invasive and cost-ineffective diagnostic toolbox that contributes to severe global mortality rates on an annual basis. Ectopic expression of the lineage survival transcription factors (LS-TFs) GATA4 and 6 promotes stomach oncogenesis. However, LS-TFs also govern important physiological roles, hindering their direct therapeutic targeting. Therefore, their downstream target genes are particularly interesting for developing cancer-specific molecular biomarkers or therapeutic agents. In this work, we couple inducible knockdown systems with chromatin immunoprecipitation and RNA-seq to thoroughly detect and characterize direct targets of GATA-mediated transcriptional regulation in gastric cancer cells. Our experimental and computational strategy provides evidence that both factors regulate the expression of several coding and non-coding RNAs that in turn mediate for their cancer-promoting phenotypes, including but not limited to cell cycle, apoptosis, ferroptosis, and oxidative stress response. Finally, the diagnostic and prognostic potential of four metagene signatures consisting of selected GATA4/6 target transcripts is evaluated in a multi-cancer panel of ~7000 biopsies from nineteen tumor types, revealing elevated specificity for gastrointestinal tumors. In conclusion, our integrated strategy uncovers the landscape of GATA-mediated coding and non-coding transcriptional regulation, providing insights regarding their molecular and clinical function in gastric cancer.

Iron homeostasis and ferroptosis in human diseases: mechanisms and therapeutic prospects

Iron, an essential mineral in the body, is involved in numerous physiological processes, making the maintenance of iron homeostasis crucial for overall health. Both iron overload and deficiency can cause various disorders and human diseases. Ferroptosis, a form of cell death dependent on iron, is characterized by the extensive peroxidation of lipids. Unlike other kinds of classical unprogrammed cell death, ferroptosis is primarily linked to disruptions in iron metabolism, lipid peroxidation, and antioxidant system imbalance. Ferroptosis is regulated through transcription, translation, and post-translational modifications, which affect cellular sensitivity to ferroptosis. Over the past decade or so, numerous diseases have been linked to ferroptosis as part of their etiology, including cancers, metabolic disorders, autoimmune diseases, central nervous system diseases, cardiovascular diseases, and musculoskeletal diseases. Ferroptosis-related proteins have become attractive targets for many major human diseases that are currently incurable, and some ferroptosis regulators have shown therapeutic effects in clinical trials although further validation of their clinical potential is needed. Therefore, in-depth analysis of ferroptosis and its potential molecular mechanisms in human diseases may offer additional strategies for clinical prevention and treatment. In this review, we discuss the physiological significance of iron homeostasis in the body, the potential contribution of ferroptosis to the etiology and development of human diseases, along with the evidence supporting targeting ferroptosis as a therapeutic approach. Importantly, we evaluate recent potential therapeutic targets and promising interventions, providing guidance for future targeted treatment therapies against human diseases.

Epigenetic regulation of targeted ferroptosis: A new strategy for drug development

Ferroptosis is a newly discovered form of cell death that is influenced by iron levels and is triggered by cellular metabolism and excessive lipid peroxidation. Epigenetic regulation plays a crucial role in the development and progression of diseases, making it essential to understand these mechanisms in order to identify potential targets for drug development and clinical treatment. The intersection of ferroptosis and epigenetics has opened up new avenues for research in drug development, offering innovative strategies for combating diseases. Recent studies have shown that epigenetic modifications can impact pathways related to ferroptosis, potentially leading to organ dysfunction. Despite the increasing focus on this relationship, the role of epigenetic regulation in drug development remains largely unexplored. This article explores current research on the interplay between epigenetic regulation and ferroptosis, delving into their regulatory mechanisms and discussing the effects of existing epigenetic modification regulators on diseases. Additionally, we highlight ongoing research on epigenetic factors involved in targeting ferroptosis in cancer, providing new insights for the development of cancer treatments.

GV-971 prevents severe acute pancreatitis by remodeling the microbiota-metabolic-immune axis

Despite recent advances, severe acute pancreatitis (SAP) remains a lethal inflammation with limited treatment options. Here, we provide compelling evidence of GV-971 (sodium oligomannate), an anti-Alzheimer's medication, as being a protective agent in various male mouse SAP models. Microbiome sequencing, along with intestinal microbiota transplantation and mass cytometry technology, unveil that GV-971 reshapes the gut microbiota, increasing Faecalibacterium populations and modulating both peripheral and intestinal immune systems. A metabolomics analysis of cecal contents from GV-971-treated SAP mice further identifies short-chain fatty acids, including propionate and butyrate, as key metabolites in inhibiting macrophage M1 polarization and subsequent lethal inflammation by blocking the MAPK pathway. These findings suggest GV-971 as a promising therapeutic for SAP by targeting the microbiota metabolic immune axis.

A ferroptosis amplifier based on triple-enhanced lipid peroxides accumulation strategy for effective pancreatic cancer therapy

As an iron dependent regulatory cell death process driven by excessive lipid peroxides (LPO), ferroptosis is recognized as a powerful weapon for pancreatic cancer (PC) therapy. However, the tumor microenvironment (TME) with hypoxia and elevated glutathione (GSH) expression not only inhibits LPO production, but also induces glutathione peroxidase 4 (GPX4) mediated LPO clearance, which greatly compromise the therapeutic outcomes of ferroptosis. To address these issues, herein, a novel triple-enhanced ferroptosis amplifier (denoted as Zal@HM-PTBC) is rationally designed. After intravenous injection, the overexpressed H2O2/GSH in TME induces the collapse of Zal@HM-PTBC and triggers the production of oxygen and reactive oxygen species (ROS), which synergistically amplify the degree of lipid peroxidation (broaden sources). Concurrently, GSH consumption because of the degradation of the hollow manganese dioxide (HM) significantly weakens the activity of GPX4, resulting in a decrease in LPO clearance (reduce expenditure). Moreover, the loading and site-directed release of zalcitabine further promotes autophagy-dependent LPO accumulation (enhance effectiveness). Both in vitro and in vivo results validated that the ferroptosis amplifier demonstrated superior specificity and favorable therapeutic responses. Overall, this triple-enhanced LPO accumulation strategy demonstrates the ability to facilitate the efficacy of ferroptosis, injecting vigorous vitality into the treatment of PC.

Ferroptosis: A Frontier in Osteoporosis

Reduced bone mass and degeneration of the microarchitecture of bone tissue are the hallmarks of osteoporosis, a bone metabolic disease that increases skeletal fragility and fracture susceptibility. Osteoporosis is primarily caused by unbalanced bone remodeling, in which bone synthesis is outpaced by bone resorption caused by osteoclasts. Along with the bone-building vitamins calcium and vitamin D, typical medications for treating osteoporosis include bisphosphonates and calcitonin. The present therapies effectively stop osteoclast activation that is too high, however they come with varying degrees of negative effects. Numerous factors can contribute to osteoporosis, which is characterized by a loss of bone mass and density due to the deterioration of the bone's microstructure, which makes the bone more fragile. As a result, it is a systemic bone condition that makes patients more likely to fracture. Interest in the function of ferroptosis in the pathophysiology of osteoporosis is developing. In this review, we go through the shape of the cell, the fundamental mechanisms of ferroptosis, the relationship between osteoclasts and osteoblasts, the association between ferroptosis and diabetic osteoporosis, steroid-induced osteoporosis, and the relationship between ferroptosis and postmenopausal osteoporosis. The functions of ferroptosis and osteoporosis in cellular function, signaling cascades, pharmacological inhibition, and gene silencing have been better understood thanks to recent advances in biomedical research.

MafG/MYH9-LCN2 axis promotes liver fibrosis through inhibiting ferroptosis of hepatic stellate cells

Hepatic stellate cells (HSCs) secrete extracellular matrix for collagen deposition, contributing to liver fibrosis. Ferroptosis is a novel type of programmed cell death induced by iron overload-dependent lipid peroxidation. Regulation of ferroptosis in hepatic stellate cells (HSCs) may have therapeutic potential for liver fibrosis. Here, we found that Maf bZIP transcription factor G (MafG) was upregulated in human and murine liver fibrosis. Interestingly, MafG knockdown increased HSCs ferroptosis, while MafG overexpression conferred resistance of HSCs to ferroptosis. Mechanistically, MafG physically interacted with non-muscle myosin heavy chain IIa (MYH9) to transcriptionally activate lipocalin 2 (LCN2) expression, a known suppressor for ferroptosis. Site-directed mutations of MARE motif blocked the binding of MafG to LCN2 promoter. Re-expression of LCN2 in MafG knockdown HSCs restored resistance to ferroptosis. In bile duct ligation (BDL)-induced mice model, we found that treatment with erastin alleviated murine liver fibrosis by inducing HSC ferroptosis. HSC-specific knowdown MafG based on adeno-associated virus 6 (AAV-6) improved erastin-induced HSC ferroptosis and alleviation of liver fibrosis. Taken together, MafG inhibited HSCs ferroptosis to promote liver fibrosis through transcriptionally activating LCN2 expression. These results suggest that MafG/MYH9-LCN2 signaling pathway could be a novel targets for the treatment of liver fibrosis.

Gandouling Regulates Ferroptosis and Improves Neuroinflammation in Wilson's Disease Through the LCN2/NLRP3 Signaling Pathway

Purpose

Neuroinflammation is a main cause of neurological damage in Wilson's disease (WD). Ferroptosis is present in the WD pathological process, which is also closely related to the neuroinflammation. LCN2, a ferroptosis-related gene in WD, is linked with the activation of NLRP3 inflammasome. Our group has previously demonstrated that Gandouling (GDL) can effectively improve neuroinflammation in WD. This study aims to investigate the protective effect of GDL on neuroinflammation in animal and cell models of WD, and whether the pharmacological mechanism is related to the LCN2/NLRP3 signaling pathway.

Methods

Toxic milk (TX) mice and HT22 cells stimulated by copper ions were selected as models. The pathology of hippocampal tissues in TX mice were observed by HE staining and transmission electron microscopy. High-throughput sequencing analysis was conducted to screen ferroptosis-related genes in WD. The expression of LCN2 and GPX4 in hippocampus of TX mice were detected by immunohistochemical. The expression of LCN2, NLRP3, GPX4, and SLC7A11 was determined in TX mice and HT22 cells by Western blotting and RT-qPCR. The levels of Fe2+, inflammatory factor indicators TNF-α, IL-1β and IL-6 and oxidative stress indicators 4-HNE, MAD, SOD, GSH and ROS were detected in each group by ELISA.

Results

The results showed that GDL ameliorated pathological and mitochondrial damages in hippocampus of TX mice. The analysis of bioinformatics showed that LCN2 was a differential gene associated with ferroptosis in WD. The results of Western blotting and RT-qPCR indicated that GDL reduced the expression of LCN2 and NLRP3, and enhanced the expression of GPX4 and SLC711 in TX mice and HT22 cells. The ELISA results showed that GDL decreased the expression of Fe2+ and inflammatory factors TNF-α, IL-1β and IL-6 in TX mice with ferroptosis inducer intervention and copper ion-loaded HT22 cells. GDL decreased the expression of oxidative stress indicators ROS, 4-HNE and MDA, and increased the expression of oxidative stress indicators GSH and SOD in TX mice and copper ion-loaded HT22 cells.

Conclusion

GDL has anti-inflammatory and antioxidant effects. LCN2 is a differential gene associated with ferroptosis in WD. GDL may alleviate ferroptosis by inhibiting the LCN2/NLPR3 signaling pathway, thereby improving neuroinflammatory responses and exerting neuroprotective effects in WD.

ATF family members as therapeutic targets in cancer: From mechanisms to pharmacological interventions

The activating transcription factor (ATF)/ cAMP-response element binding protein (CREB) family represents a large group of basic zone leucine zip (bZIP) transcription factors (TFs) with a variety of physiological functions, such as endoplasmic reticulum (ER) stress, amino acid stress, heat stress, oxidative stress, integrated stress response (ISR) and thus inducing cell survival or apoptosis. Interestingly, ATF family has been increasingly implicated in autophagy and ferroptosis in recent years. Thus, the ATF family is important for homeostasis and its dysregulation may promote disease progression including cancer. Current therapeutic approaches to modulate the ATF family include direct modulators, upstream modulators, post-translational modifications (PTMs) modulators. This review summarizes the structural domain and the PTMs feature of the ATF/CREB family and comprehensively explores the molecular regulatory mechanisms. On this basis, their pathways affecting proliferation, metastasis, and drug resistance in various types of cancer cells are sorted out and discussed. We then systematically summarize the status of the therapeutic applications of existing ATF family modulators and finally look forward to the future prospect of clinical applications in the treatment of tumors by modulating the ATF family.

E3 ubiquitin ligase RBCK1 confers ferroptosis resistance in pancreatic cancer by facilitating MFN2 degradation

Ferroptosis, a novel form of iron-dependent non-apoptotic cell death, plays an active role in the pathogenesis of diverse diseases, including cancer. However, the mechanism through which ferroptosis is regulated in pancreatic ductal adenocarcinoma (PDAC) remains unclear. Here, our study, via combining bioinformatic analysis with experimental validation, showed that ferroptosis is inhibited in PDAC. Genome-wide sequencing further revealed that the ferroptosis activator imidazole ketone erastin (IKE) induced upregulation of the E3 ubiquitin ligase RBCK1 in PDAC cells at the transcriptional or translational level. RBCK1 depletion or knockdown rendered PDAC cells more vulnerable to IKE-induced ferroptotic death in vitro. In a mouse xenograft model, genetic depletion of RBCK1 increased the killing effects of ferroptosis inducer on PDAC cells. Mechanistically, RBCK1 interacts with and polyubiquitylates mitofusin 2 (MFN2), a key regulator of mitochondrial dynamics, to facilitate its proteasomal degradation under ferroptotic stress, leading to decreased mitochondrial reactive oxygen species (ROS) production and lipid peroxidation. These findings not only provide new insights into the defense mechanisms of PDAC cells against ferroptotic death but also indicate that targeting the RBCK1-MFN2 axis may be a promising option for treating patients with PDAC.

A systematic exploration of unexploited genes for oxidative stress in Parkinson's disease

Human disease-associated gene data are accessible through databases, including the Open Targets Platform, DisGeNET, miRTex, RNADisease, and PubChem. However, missing data entries in such databases are anticipated because of curational errors, biases, and text-mining failures. Additionally, the extensive research on human diseases has led to challenges in registering comprehensive data. The lack of essential data in databases hinders knowledge sharing and should be addressed. Therefore, we propose an analysis pipeline to explore missing entries of unexploited genes in the human disease-associated gene databases. Using this pipeline for genes in Parkinson's disease with oxidative stress revealed two unexploited genes: nuclear protein 1 (NUPR1) and ubiquitin-like with PHD and ring finger domains 2 (UHRF2). This methodology enhances the identification of underrepresented disease-associated genes, facilitating easier access to potential human disease-related functional genes. This study aims to identify unexploited genes for further research and does not include independent experimental validation.

Alkaliptosis induction counteracts paclitaxel-resistant ovarian cancer cells via ATP6V0D1-mediated ABCB1 inhibition

Paclitaxel serves as the cornerstone chemotherapy for ovarian cancer, yet its prolonged administration frequently culminates in drug resistance, presenting a substantial challenge. Here we reported that inducing alkaliptosis, rather than apoptosis or ferroptosis, effectively overcomes paclitaxel resistance. Mechanistically, ATPase H+ transporting V0 subunit D1 (ATP6V0D1), a key regulator of alkaliptosis, plays a pivotal role by mediating the downregulation of ATP-binding cassette subfamily B member 1 (ABCB1), a multidrug resistance protein. Both ATP6V0D1 overexpression through gene transfection and pharmacological enhancement of ATP6V0D1 protein stability using JTC801 effectively inhibit ABCB1 upregulation, resulting in growth inhibition in drug-resistant cells. Additionally, increasing intracellular pH to alkaline (pH 8.5) via sodium hydroxide application suppresses ABCB1 expression, whereas reducing the pH to acidic conditions (pH 6.5) with hydrochloric acid amplifies ABCB1 expression in drug-resistant cells. Collectively, these results indicate a potentially effective therapeutic strategy for targeting paclitaxel-resistant ovarian cancer by inducing ATP6V0D1-dependent alkaliptosis.

Aging limits stemness and tumorigenesis in the lung by reprogramming iron homeostasis

Aging is associated with a decline in the number and fitness of adult stem cells 1-4 . Aging-associated loss of stemness is posited to suppress tumorigenesis 5,6 , but this hypothesis has not been tested in vivo . Here, using physiologically aged autochthonous genetically engineered mouse models and primary cells 7,8 , we demonstrate aging suppresses lung cancer initiation and progression by degrading stemness of the alveolar cell of origin. This phenotype is underpinned by aging-associated induction of the transcription factor NUPR1 and its downstream target lipocalin-2 in the cell of origin in mice and humans, leading to a functional iron insufficiency in the aged cells. Genetic inactivation of the NUPR1-lipocalin-2 axis or iron supplementation rescue stemness and promote tumorigenic potential of aged alveolar cells. Conversely, targeting the NUPR1- lipocalin-2 axis is detrimental to young alveolar cells via induction of ferroptosis. We find that aging-associated DNA hypomethylation at specific enhancer sites associates with elevated NUPR1 expression, which is recapitulated in young alveolar cells by inhibition of DNA methylation. We uncover that aging drives a functional iron insufficiency, which leads to loss of stemness and tumorigenesis, but promotes resistance to ferroptosis. These findings have significant implications for the therapeutic modulation of cellular iron homeostasis in regenerative medicine and in cancer prevention. Furthermore, our findings are consistent with a model whereby most human cancers initiate in young individuals, revealing a critical window for such cancer prevention efforts.

Molecular maps of synovial cells in inflammatory arthritis using an optimized synovial tissue dissociation protocol

In this study, we optimized the dissociation of synovial tissue biopsies for single-cell omics studies and created a single-cell atlas of human synovium in inflammatory arthritis. The optimized protocol allowed consistent isolation of highly viable cells from tiny fresh synovial biopsies, minimizing the synovial biopsy drop-out rate. The synovium scRNA-seq atlas contained over 100,000 unsorted synovial cells from 25 synovial tissues affected by inflammatory arthritis, including 16 structural, 11 lymphoid, and 15 myeloid cell clusters. This synovial cell map expanded the diversity of synovial cell types/states, detected synovial neutrophils, and broadened synovial endothelial cell classification. We revealed tissue-resident macrophage subsets with proposed matrix-sensing (FOLR2+COLEC12high) and iron-recycling (LYVE1+SLC40A1+) activities and identified fibroblast subsets with proposed functions in cartilage breakdown (SOD2highSAA1+SAA2+SDC4+) and extracellular matrix remodeling (SERPINE1+COL5A3+LOXL2+). Our study offers an efficient synovium dissociation method and a reference scRNA-seq resource, that advances the current understanding of synovial cell heterogeneity in inflammatory arthritis.

Activation of the integrated stress response in human hair follicles

Unravelling how energy metabolism and stress responses are regulated in human scalp hair follicles could reveal novel insights into the controls of hair growth and provide new targets to manage hair loss disorders. The Mitochondrial Pyruvate Carrier (MPC) imports pyruvate, produced via glycolysis, into the mitochondria, fuelling the TCA cycle. Previous work has shown that MPC inhibition promotes lactate generation, which activates murine epithelial hair follicle stem cells (eHFSCs). However, by pharmacologically targeting the MPC in short-term human hair follicle ex vivo organ culture experiments using UK-5099, we induced metabolic stress-responsive proliferative arrest throughout the human hair follicle epithelium, including within Keratin 15+ eHFSCs. Through transcriptomics, MPC inhibition was shown to promote a gene expression signature indicative of disrupted FGF, IGF, TGFβ and WNT signalling, mitochondrial dysfunction, and activation of the integrated stress response (ISR), which can arrest cell cycle progression. The ISR, mediated by the transcription factor ATF4, is activated by stressors including amino acid deprivation and ER stress, consistent with MPC inhibition within our model. Using RNAScope, we confirmed the upregulation of both ATF4 and the highly upregulated ATF4-target gene ADM2 on human hair follicle tissue sections in situ. Moreover, treatment with the ISR inhibitor ISRIB attenuated both the upregulation of ADM2 and the proliferative block imposed via MPC inhibition. Together, this work reveals how the human hair follicle, as a complex and metabolically active human tissue system, can dynamically adapt to metabolic stress.

Ciprofloxacin is a novel anti-ferroptotic antibiotic

Cancer patients undergoing chemotherapy are susceptible to various bacterial infections, necessitating prompt and precise antimicrobial treatment with antibiotics. Ciprofloxacin is a clinically utilized broad-spectrum antimicrobial agent known for its robust antiseptic activity. While ferroptosis, an oxidative form of cell death, has garnered attention as a promising avenue in cancer therapy, the potential impact of ciprofloxacin on the anticancer effects of ferroptosis remains unclear. This study seeks to investigate the potential influence of antibiotics on ferroptosis in human pancreatic ductal adenocarcinoma (PDAC) cells. Here, we report a previously unrecognized role of ciprofloxacin in inhibiting ferroptosis in human PDAC cells. Mechanistically, ciprofloxacin suppresses erastin-induced endoplasmic reticulum (ER) stress through the activating transcription factor 6 (ATF6) and ER to nucleus signaling 1 (ERN1) pathway. Excessive ER stress activation can trigger glutathione peroxidase 4 (GPX4) degradation through autophagic mechanisms. In contrast, ciprofloxacin enhances the protein stability of GPX4, a crucial regulator that suppresses ferroptosis by inhibiting lipid peroxidation. Thus, our study demonstrates the anti-ferroptotic role of ciprofloxacin, highlighting the importance of careful consideration when contemplating the combination of ciprofloxacin with specific ferroptosis inducers in PDAC patients.

Ferroptosis: principles and significance in health and disease

Ferroptosis, an iron-dependent form of cell death characterized by uncontrolled lipid peroxidation, is governed by molecular networks involving diverse molecules and organelles. Since its recognition as a non-apoptotic cell death pathway in 2012, ferroptosis has emerged as a crucial mechanism in numerous physiological and pathological contexts, leading to significant therapeutic advancements across a wide range of diseases. This review summarizes the fundamental molecular mechanisms and regulatory pathways underlying ferroptosis, including both GPX4-dependent and -independent antioxidant mechanisms. Additionally, we examine the involvement of ferroptosis in various pathological conditions, including cancer, neurodegenerative diseases, sepsis, ischemia-reperfusion injury, autoimmune disorders, and metabolic disorders. Specifically, we explore the role of ferroptosis in response to chemotherapy, radiotherapy, immunotherapy, nanotherapy, and targeted therapy. Furthermore, we discuss pharmacological strategies for modulating ferroptosis and potential biomarkers for monitoring this process. Lastly, we elucidate the interplay between ferroptosis and other forms of regulated cell death. Such insights hold promise for advancing our understanding of ferroptosis in the context of human health and disease.

The cell biology of ferroptosis

Ferroptosis is a non-apoptotic cell death mechanism characterized by iron-dependent membrane lipid peroxidation. Here, we review what is known about the cellular mechanisms mediating the execution and regulation of ferroptosis. We first consider how the accumulation of membrane lipid peroxides leads to the execution of ferroptosis by altering ion transport across the plasma membrane. We then discuss how metabolites and enzymes that are distributed in different compartments and organelles throughout the cell can regulate sensitivity to ferroptosis by impinging upon iron, lipid and redox metabolism. Indeed, metabolic pathways that reside in the mitochondria, endoplasmic reticulum, lipid droplets, peroxisomes and other organelles all contribute to the regulation of ferroptosis sensitivity. We note how the regulation of ferroptosis sensitivity by these different organelles and pathways seems to vary between different cells and death-inducing conditions. We also highlight transcriptional master regulators that integrate the functions of different pathways and organelles to modulate ferroptosis sensitivity globally. Throughout this Review, we highlight open questions and areas in which progress is needed to better understand the cell biology of ferroptosis.

Ferroptosis: a critical mechanism of N6-methyladenosine modification involved in carcinogenesis and tumor progression

Ferroptosis is an iron-dependent regulatory cell necrosis induced by iron overload and lipid peroxidation. It occurs when multiple redox-active enzymes are ectopically expressed or show abnormal function. Hence, the precise regulation of ferroptosis-related molecules is mediated across multiple levels, including transcriptional, posttranscriptional, translational, and epigenetic levels. N6-methyladenosine (m6A) is a highly evolutionarily conserved epigenetic modification in mammals. The m6A modification is commonly linked to tumor proliferation, progression, and therapy resistance because it is involved in RNA metabolic processes. Intriguingly, accumulating evidence suggests that dysregulated ferroptosis caused by the m6A modification drives tumor development. In this review, we summarized the roles of m6A regulators in ferroptosis-mediated malignant tumor progression and outlined the m6A regulatory mechanism involved in ferroptosis pathways. We also analyzed the potential value and application strategies of targeting m6A/ferroptosis pathway in the clinical diagnosis and therapy of tumors.

Understanding the (epi)genetic dysregulation in Parkinson's disease through an integrative brain competitive endogenous RNA network

Parkinson's disease (PD) is a rapidly growing neurodegenerative disorder characterized by dopaminergic neuron loss in the substantia nigra pars compacta (SN) and aggregation of α-synuclein. Its aetiology involves a multifaceted interplay among genetic, environmental, and epigenetic factors. We integrated brain gene expression data from PD patients to construct a comprehensive regulatory network encompassing messenger RNAs (mRNAs), microRNAs (miRNAs), circular RNAs (circRNAs) and, for the first time, RNA binding proteins (RBPs). Expression data from the SN of PD patients and controls were systematically selected from public databases to identify combined differentially expressed genes (DEGs). Brain co-expression analysis revealed modules comprising significant DEGs that function cooperatively. The relationships among co-expressed DEGs, miRNAs, circRNAs, and RBPs revealed an intricate competitive endogenous RNA (ceRNA) network responsible for post-transcriptional dysregulation in PD. Many genes in the ceRNA network, including the TOMM20 and HMGCR genes, overlap with the most relevant genes in our previous Alzheimer's disease-associated ceRNA network, suggesting common underlying mechanisms between both conditions. Moreover, in the ceRNA subnetwork, the RBP Aly/REF export factor (ALYREF), which acts as an RNA 5-methylcytosine(m5C)-binding protein, stood out. Our data sheds new light on the potential role of brain ceRNA networks in PD pathogenesis.

CircPIAS1 promotes hepatocellular carcinoma progression by inhibiting ferroptosis via the miR-455-3p/NUPR1/FTH1 axis

BACKGROUND

The role of circRNAs in hepatocellular carcinoma (HCC) progression remains unclear. CircPIAS1 (circBase ID: hsa_circ_0007088) was identified as overexpressed in HCC cases through bioinformatics analysis. This study aimed to investigate the oncogenic properties and mechanisms of circPIAS1 in HCC development.

METHODS

Functional analyses were conducted to assess circPIAS1's impact on HCC cell proliferation, migration, and ferroptosis. Xenograft mouse models were employed to evaluate circPIAS1's effects on tumor growth and pulmonary metastasis in vivo. Bioinformatics analysis, RNA immunoprecipitation, and luciferase reporter assays were utilized to elucidate the molecular pathways influenced by circPIAS1. Additional techniques, including RNA pulldown, fluorescence in situ hybridization (FISH), chromatin immunoprecipitation (ChIP), qPCR, and western blotting, were used to further explore the underlying mechanisms.

RESULTS

CircPIAS1 expression was elevated in HCC tissues and cells. Silencing circPIAS1 suppressed HCC cell proliferation and migration both in vitro and in vivo. Mechanically, circPIAS1 overexpression inhibited ferroptosis by competitively binding to miR-455-3p, leading to upregulation of Nuclear Protein 1 (NUPR1). Furthermore, NUPR1 promoted FTH1 transcription, enhancing iron storage in HCC cells and conferring resistance to ferroptosis. Treatment with ZZW-115, an NUPR1 inhibitor, reversed the tumor-promoting effects of circPIAS1 and sensitized HCC cells to lenvatinib.

CONCLUSION

This study highlights the critical role of circPIAS1 in HCC progression through modulation of ferroptosis. Targeting the circPIAS1/miR-455-3p/NUPR1/FTH1 regulatory axis may represent a promising therapeutic strategy for HCC.

Ferroptosis: a potential bridge linking gut microbiota and chronic kidney disease

Ferroptosis is a novel form of lipid peroxidation-driven, iron-dependent programmed cell death. Various metabolic pathways, including those involved in lipid and iron metabolism, contribute to ferroptosis regulation. The gut microbiota not only supplies nutrients and energy to the host, but also plays a crucial role in immune modulation and metabolic balance. In this review, we explore the metabolic pathways associated with ferroptosis and the impact of the gut microbiota on host metabolism. We subsequently summarize recent studies on the influence and regulation of ferroptosis by the gut microbiota and discuss potential mechanisms through which the gut microbiota affects ferroptosis. Additionally, we conduct a bibliometric analysis of the relationship between the gut microbiota and ferroptosis in the context of chronic kidney disease. This analysis can provide new insights into the current research status and future of ferroptosis and the gut microbiota.

Ferroptotic therapy in cancer: benefits, side effects, and risks

Ferroptosis is a type of regulated cell death characterized by iron accumulation and uncontrolled lipid peroxidation, leading to plasma membrane rupture and intracellular content release. Originally investigated as a targeted therapy for cancer cells carrying oncogenic RAS mutations, ferroptosis induction now exhibits potential to complement chemotherapy, immunotherapy, and radiotherapy in various cancer types. However, it can lead to side effects, including immune cell death, bone marrow impairment, liver and kidney damage, cachexia (severe weight loss and muscle wasting), and secondary tumorigenesis. In this review, we discuss the advantages and offer an overview of the diverse range of documented side effects. Furthermore, we examine the underlying mechanisms and explore potential strategies for side effect mitigation.

Unresolved questions regarding cellular cysteine sources and their possible relationships to ferroptosis

Cysteine is required for synthesis of glutathione (GSH), coenzyme A, other sulfur-containing metabolites, and most proteins. In most cells, cysteine comes from extracellular disulfide sources including cystine, glutathione-disulfide, and peptides. The thioredoxin reductase-1 (TrxR1)- or glutathione-disulfide reductase (GSR)-driven enzymatic systems can fuel cystine reduction via thioredoxins, glutaredoxins, or other thioredoxin-fold proteins. Free cystine enters cells thorough the cystine-glutamate antiporter, xCT, but systemically, plasma glutathione-disulfide might predominate as a cystine source. Erastin, inhibiting both xCT and voltage-dependent anion channels, induces ferroptotic cell death, so named because this type of cell death is antagonized by iron-chelators. Many cancer cells seem to be predisposed to ferroptosis, which has been proposed as a targetable cancer liability. Ferroptosis is associated with lipid peroxidation and loss of either glutathione peroxidase-4 (GPX4) or ferroptosis suppressor protein-1 (FSP1), which each prevent accumulation of lipid peroxides. It has been suggested that an xCT inhibition-induced cellular cysteine-deficiency lowers GSH levels, starving GPX4 for reducing power and allowing membrane lipid peroxides to accumulate, thereby causing ferroptosis. Aspects of ferroptosis are however not fully understood and need to be further scrutinized, for example that neither disruption of GSH synthesis, loss of GSH, nor disruption of glutathione disulfide reductase (GSR), triggers ferroptosis in animal models. Here we reevaluate the relationships between Erastin, xCT, GPX4, cellular cysteine and GSH, RSL3 or ML162, and ferroptosis. We conclude that, whereas both Cys and ferroptosis are potential liabilities in cancer, their relationship to each other remains insufficiently understood.

Targeting ferroptosis for leukemia therapy: exploring novel strategies from its mechanisms and role in leukemia based on nanotechnology

The latest findings in iron metabolism and the newly uncovered process of ferroptosis have paved the way for new potential strategies in anti-leukemia treatments. In the current project, we reviewed and summarized the current role of nanomedicine in the treatment and diagnosis of leukemia through a comparison made between traditional approaches applied in the treatment and diagnosis of leukemia via the existing investigations about the ferroptosis molecular mechanisms involved in various anti-tumor treatments. The application of nanotechnology and other novel technologies may provide a new direction in ferroptosis-driven leukemia therapies. The article explores the potential of targeting ferroptosis, a new form of regulated cell death, as a new therapeutic strategy for leukemia. It discusses the mechanisms of ferroptosis and its role in leukemia and how nanotechnology can enhance the delivery and efficacy of ferroptosis-inducing agents. The article not only highlights the promise of ferroptosis-targeted therapies and nanotechnology in revolutionizing leukemia treatment, but also calls for further research to overcome challenges and fully realize the clinical potential of this innovative approach. Finally, it discusses the challenges and opportunities in clinical applications of ferroptosis.

G-4 inhibits triple negative breast cancer by inducing cell apoptosis and promoting LCN2-dependent ferroptosis

Compound G-4 is a derivate of cyclin-dependent kinase inhibitor Rocovitine and showed strong sensitivity to triple negative breast cancer (TNBC) cells. In this study, the antitumor activity, mechanism and possible targets of G-4 in TNBC were investigated. Flow cytometry and immunoblotting showed that G-4 not only arrested the S phase of the cell cycle, but also induced apoptosis in TNBC cells via the mitochondrial pathway through inhibiting epidermal growth factor receptor (EGFR), AKT and MAPK pathways. In addition, G-4 induced the iron-mutagenesis process in TNBC cells and down-regulated differentially expressed gene lipid carrier protein 2 (LCN2) by RNA-seq. Moreover, G-4 elevated levels of cytosolic reactive oxygen species (ROS), lipid ROS, Fe and malondialdehyde (MDA), but decreased levels of superoxide dismutase (SOD) and glutathione (GSH), consistent with the effects of iron-mutagenic agonists Erastin and RSL3, which were inhibited by the iron inhibitor ferrostatin-1 (Fer-1). Furthermore, a LCN2 knockdown cell model was established by siRNA transfection, the IC50 of G-4 was increased nearly 100-fold, accompanied by a trend of no ferroptosis characteristic index. The results indicated that G-4 suppressed the malignant phenotype of TNBC, induced apoptosis by inhibiting EGFR pathway and promoted LCN2-dependent ferroptosis.

WTAP Mediates NUPR1 Regulation of LCN2 Through m6A Modification to Influence Ferroptosis, Thereby Promoting Breast Cancer Proliferation, Migration and Invasion

Ferroptosis is involved in various pathophysiological diseases, including triple-negative breast cancer (TNBC). Targeting ferroptosis is considered as a novel anti-TNBC strategy. Nevertheless, the regulatory mechanism of ferroptosis during TNBC progression is unclear. Here, the role of WTAP in ferroptosis during TNBC progression  was investigated. The clinicopathological significance of WTAP, NUPR1 and LCN2 was analyzed by Kaplan-Meier method. Cell viability was assessed using MTT assay. Transwell assay was employed to analyze cell migration and invasion. GSH/GSSG and Fe2+ levels in TNBC cells were analyzed using kits. m6A level was examined using m6A dot blot assay. NUPR1 mRNA stability was analyzed using RNA degradation assay. RIP was performed to analyze the interaction between eIF3a and NURP1. Herein, our results revealed that WTAP, NUPR1 and LCN2 expressions were significantly elevated in TNBC. NUPR1 silencing inhibited TNBC cell proliferation, migration and invasion by inducing ferroptosis. NUPR1 positively regulated LCN2 expression in TNBC cells, and LCN2 knockdown induced ferroptosis to suppress TNBC cell malignant behaviors. Our molecular study further revealed that WTAP promoted NUPR1 expression in an m6A-EIF3A mediated manner. And, as expected, WTAP knockdown promoted ferroptosis to suppress TNBC cell malignant behaviors, which were abrogated by NUPR1 overexpression. WTAP upregulated LCN2 by regulation of NUPR1 m6A modification, thereby suppressing ferroptosis to contribute to accelerate TNBC progression. Our study revealed the cancer-promoting effect of WTAP, NUPR1 and LCN2 in TNBC and clarified the relevant mechanism, providing a theoretical basis for developing novel diagnostic and therapeutic strategies for TNBC.

ATF4 in cellular stress, ferroptosis, and cancer

Activating transcription factor 4 (ATF4), a member of the ATF/cAMP response element-binding (CREB) family, plays a critical role as a stress-induced transcription factor. It orchestrates cellular responses, particularly in the management of endoplasmic reticulum stress, amino acid deprivation, and oxidative challenges. ATF4's primary function lies in regulating gene expression to ensure cell survival during stressful conditions. However, when considering its involvement in ferroptosis, characterized by severe lipid peroxidation and pronounced endoplasmic reticulum stress, the ATF4 pathway can either inhibit or promote ferroptosis. This intricate relationship underscores the complexity of cellular responses to varying stress levels. Understanding the connections between ATF4, ferroptosis, and endoplasmic reticulum stress holds promise for innovative cancer therapies, especially in addressing apoptosis-resistant cells. In this review, we provide an overview of ATF4, including its structure, modifications, and functions, and delve into its dual role in both ferroptosis and cancer.

Ferroptosis mechanisms and regulations in cardiovascular diseases in the past, present, and future

Cardiovascular diseases (CVDs) are the main diseases that endanger human health, and their risk factors contribute to high morbidity and a high rate of hospitalization. Cell death is the most important pathophysiology in CVDs. As one of the cell death mechanisms, ferroptosis is a new form of regulated cell death (RCD) that broadly participates in CVDs (such as myocardial infarction, heart transplantation, atherosclerosis, heart failure, ischaemia/reperfusion (I/R) injury, atrial fibrillation, cardiomyopathy (radiation-induced cardiomyopathy, diabetes cardiomyopathy, sepsis-induced cardiac injury, doxorubicin-induced cardiac injury, iron overload cardiomyopathy, and hypertrophic cardiomyopathy), and pulmonary arterial hypertension), involving in iron regulation, metabolic mechanism and lipid peroxidation. This article reviews recent research on the mechanism and regulation of ferroptosis and its relationship with the occurrence and treatment of CVDs, aiming to provide new ideas and treatment targets for the clinical diagnosis and treatment of CVDs by clarifying the latest progress in CVDs research.

CRISPR/Cas9 model of prostate cancer identifies Kmt2c deficiency as a metastatic driver by Odam/Cabs1 gene cluster expression

Metastatic prostate cancer (PCa) poses a significant therapeutic challenge with high mortality rates. Utilizing CRISPR-Cas9 in vivo, we target five potential tumor suppressor genes (Pten, Trp53, Rb1, Stk11, and RnaseL) in the mouse prostate, reaching humane endpoint after eight weeks without metastasis. By further depleting three epigenetic factors (Kmt2c, Kmt2d, and Zbtb16), lung metastases are present in all mice. While whole genome sequencing reveals few mutations in coding sequence, RNA sequencing shows significant dysregulation, especially in a conserved genomic region at chr5qE1 regulated by KMT2C. Depleting Odam and Cabs1 in this region prevents metastasis. Notably, the gene expression signatures, resulting from our study, predict progression-free and overall survival and distinguish primary and metastatic human prostate cancer. This study emphasizes positive genetic interactions between classical tumor suppressor genes and epigenetic modulators in metastatic PCa progression, offering insights into potential treatments.