Patulin Induces Acute Kidney Injury in Mice through Autophagy-Ferroptosis Pathway

Selenium-enriched Kazachstania unispora KU2 ameliorates patulin-induced intestinal injury in mice by mediating the gut microbiota and selenoprotein P synthesis

Patulin (PAT) is a foodborne mycotoxin that causes intestinal injury. Selenium (Se)-enriched Kazachstania unispora (K. unispora) KU2 is a novel dietary Se carrier, and Se exerts important roles in intestinal homeostasis. Here, we examined the ameliorative effects of K. unispora KU2 and Se-enriched K. unispora KU2 against PAT-induced intestinal injury. Results indicated that both K. unispora KU2 and Se-enriched K. unispora KU2 alleviated PAT-induced inflammatory infiltration, disrupted gut microbiota, and associated metabolic imbalances, indicating the probiotic potential of this strain. Se-enriched K. unispora KU2 exhibited more pronounced remediation comparable to K. unispora KU2, revealing the promoting effect of Se. Furthermore, Se-enriched K. unispora KU2 restored intestinal Se homeostasis by upregulating SEPP1 levels to mitigate intestinal injury. Using pseudo germ-free mouse models, we confirmed that gut microbiota was required for the improvement in SEPP1 synthesis and intestinal transport mediated by Se-enriched K. unispora KU2. These findings elucidate a mechanism whereby the alleviation of PAT-induced intestinal injury by Se-enriched K. unispora KU2 is linked to upregulation of SEPP1 by the gut microbiota, suggesting its potential therapeutic relevance for intestinal diseases.

The mitochondrial dysfunction regulated by JAK2/STAT3 pathway leads to the necroptosis in the renal cells under patulin exposure

Patulin (PAT) is a common mycotoxin widely found in various agricultural products and fruits, which has obvious toxic effects on animals and humans. Some studies have shown that PAT can cause nephrotoxicity, but the exact mechanism remains to be elucidated. In the present study, we investigated PAT-induced nephrotoxicity and the possible molecular mechanisms involved in its action. In vivo, the results showed that PAT affected the integrity of the glomerular basement membrane and peduncles, leading to necroptosis. We further demonstrated that PAT up-regulated the expression of JAK2, STAT3, RIPK1, RIPK3, and MLKL. This observation was also confirmed in MPC-5 cells. In vitro, pretreatment with Nec-1 (a specific inhibitor of necroptosis) or si-STAT3 resulted in a significant reduction in necroptosis and improved mitochondrial dysfunction. Notably, the pharmacological protection of mitochondrial function by SS-31 significantly attenuated the onset of PAT-induced necroptosis. Taken together, our study suggested that STAT3 activation, and mitochondrial dysfunction played critical roles in PAT-induced necroptosis in the kidney. These findings revealed the mechanisms by which PAT triggered necroptosis, potentially providing a new therapeutic strategy for PAT poisoning.

The role of ferroptosis in acute kidney injury: mechanisms and potential therapeutic targets

Acute kidney injury (AKI) is one of the most common and severe clinical renal syndromes with high morbidity and mortality. Ferroptosis is a form of programmed cell death (PCD), is characterized by iron overload, reactive oxygen species accumulation, and lipid peroxidation. As ferroptosis has been increasingly studied in recent years, it is closely associated with the pathophysiological process of AKI and provides a target for the treatment of AKI. This review offers a comprehensive overview of the regulatory mechanisms of ferroptosis, summarizes its role in various AKI models, and explores its interaction with other forms of cell death, it also presents research on ferroptosis in AKI progression to other diseases. Additionally, the review highlights methods for detecting and assessing AKI through the lens of ferroptosis and describes potential inhibitors of ferroptosis for AKI treatment. Finally, the review presents a perspective on the future of clinical AKI treatment, aiming to stimulate further research on ferroptosis in AKI.

Patulin-degrading enzymes sources, structures, and mechanisms: A review

Patulin (PAT), a fungal secondary metabolite with multiple toxicities, is an unavoidable contaminant in fruit and vegetable processing, posing potential health risks to consumers and causing significant economic losses to the global food industry. Traditional control strategies, such as physical and chemical methods, face several challenges, including low efficiency, high costs, and unverified safety. In contrast, microbial degradation of patulin is considered a more efficient and environmentally friendly approach, which has become a popular research focus. However, there is still insufficient research on the key degradation enzymes involved in microorganisms. Therefore, this review comprehensively summarizes recent research progress on the biological degradation of patulin, with a focus on microbial species capable of degrading patulin, the degradation enzymes they express, potential degradation mechanisms, and the toxicity of degradation products, while providing prospects for future research. It offers valuable insights for controlling patulin in food and stimulates further investigation. Ultimately, this review aims to promote the development of efficient and eco-friendly methods to mitigate patulin contamination in fruits and vegetables.

The connection between autophagy and ferroptosis in AKI: recent advances regarding selective autophagy

Acute kidney injury (AKI) is a significant issue in public health, displaying a high occurrence rate and mortality rate. Ferroptosis, a form of programmed cell death (PCD), is characterized by iron accumulation and intensified lipid peroxidation. Recent studies have demonstrated the pivotal significance of ferroptosis in AKI caused by diverse stimuli, including ischemia-reperfusion injury (IRI), sepsis and toxins. Autophagy, a multistep process that targets damaged organelles and macromolecules for degradation and recycling, also plays an essential role in AKI. Previous research has demonstrated that autophagy deletion in proximal tubules could aggravate tubular injury and renal function loss, indicating the protective function of autophagy in AKI. Consequently, finding ways to stimulate autophagy has become a crucial therapeutic strategy. The recent discovery of the role of selective autophagy in influencing ferroptosis has identified new therapeutic targets for AKI and has highlighted the importance of understanding the cross-talk between autophagy and ferroptosis. This study aims to provide an overview of the signaling pathways involved in ferroptosis and autophagy, focusing on the mechanisms and functions of selective autophagy and autophagy-dependent ferroptosis. We hope to establish a foundation for future investigations into the interaction between autophagy and ferroptosis in AKI as well as other diseases.

DEHP regulates ferritinophagy to promote testicular ferroptosis via suppressing SIRT1/PGC-1α pathway

To increase elasticity and flexibility, di-2-ethylhexyl phthalate (DEHP) is used in a variety of industrial products, but excessive exposure to it can pose a threat to human health. In epidemiological studies of population exposure to DEHP, attention has been paid to damage to the male reproductive system. However, the toxicological mechanism of DEHP regarding testicular injury is not well understood. We used Western blot analysis, transmission electron microscopy, fluorescence staining, transient transfection and assay kit to detect relevant indicators, and the results were as follows: After DEHP exposure, the expression levels of ACSL4, COX2, TF, FTH1, LC3, AMPK, p-AMPK, ULK1, p-ULK1, serum iron, tissue iron and MDA in the exposure group were significantly increased. The expression levels of GPX4, NCOA4, p62, SIRT1, and PGC-1α, as well as the contents of GSH and ATP, decreased. Electron microscopy showed that more autophagosomes were observed. Our findings suggest that exposure to DEHP induced ferritinophagy and ferroptosis in the testis. In vitro, the promoting effect of ferritinophagy on ferroptosis was verified by applying the autophagy inhibitor (3-MA) and si-NCOA4. Moreover, Mono-(2-ethylhexyl) phthalate (MEHP) inhibited the mitochondrial regulatory protein SIRT1/PGC-1α, leading to mitochondrial dysfunction. Changes in mitochondrial reactive oxygen species (MtROS) and energy over-activated AMPK/ULK1 autophagy pathway, and then promoted ferritinophagy, which increased the sensitivity of TM4 cells to ferroptosis. This research offers a theoretical framework for the prevention and management of DEHP-induced harm.

Zearalenone induces liver injury in mice through ferroptosis pathway

Throughout the world, some foods and feeds commonly consumed by humans and animals are inadvertently contaminated with mycotoxins. Zearalenone (ZEA) is a typical environmental/food contaminant that can cause varying degrees of damage to the body, such as reproductive toxicity, hepatotoxicity, immunotoxicity, etc. It poses a serious threat to the living environment and human and animal health. Increasing evidence shows that mycotoxin-induced organ damage may be closely related to ferroptosis. However, the mechanism of ZEA-induced liver injury is still not fully understood. Therefore, this study aimed to explore whether ZEA can trigger ferroptosis in the liver and cause liver injury. This study was conducted by establishing in vivo and in vitro ZEA exposure models. The results showed that ZEA exposure led to typical liver injury indicators. ZEA inhibited the Nrf2/keap1 antioxidant signaling pathway, aggravated the oxidative stress response, and inhibited the body's antioxidant function. Additionally, it was found that ZEA can aggravate lipid peroxidation by blocking the system Xc-/GSH/GPX4 axis, upregulating the protein expression of ACSL4, and affecting the import, storage, and export of iron ions, thereby inducing iron ion metabolism disorders. A combination of multiple factors induces ferroptosis in mouse liver and AML12 cells. Pretreatment with deferoxamine, an inhibitor of ferroptosis, can alleviate ferroptosis damage induced by ZEA, indicating the crucial role of ferroptosis in cell damage caused by ZEA. This study deeply explores the hepatic ferroptosis pathway induced by ZEA, provides a new theoretical basis for ZEA-induced hepatotoxicity, and offers new insights for exploring potential treatment strategies.

Ferroptosis is involved in quercetin-mediated alleviation of Ochratoxin A-induced kidney damage

Ochratoxin A (OTA) induces kidney damage in animals and humans. Ferroptosis is an iron-dependent form of regulated cell death that is involved in OTA-induced kidney injury. Quercetin (QCT), which is commonly found in numerous fruit and vegetables, has extensive pharmacological properties, such as anti-oxidant and anti-inflammatory. The present study aimed to evaluate the effects of QCT on OTA-induced kidney damage and the associated ferroptosis mechanism in mice. The results showed that OTA induced kidney damage, as demonstrated by the presence of kidney histopathological lesions, increased serum BUN and CRE levels, mRNA levels of Ntn1, Kim1, Tnfa, Ilb and Il6, and immunofluorescence of TNFα. OTA induced lipid peroxidation and ferroptosis by increasing the MDA level, 4-HNE production, and the iron concentration, decreasing the GSH content, increasing ACSL4 and HO-1 mRNA and protein levels, and decreasing GPX4 mRNA and protein levels. QCT supplementation alleviated OTA-induced kidney damage and inhibited OTA-induced lipid peroxidation and ferroptosis by reversing the OTA-induced above changes. Erastin weakened the protective effects of QCT on the histopathological damage, renal function, and inflammation induced by OTA. These findings indicated that QCT alleviated OTA-induced kidney injury through ferroptosis, suggesting that QCT might serve as a feed additive in mycotoxin contamination environments.

Process, advances, and perspectives of graphene oxide-SELEX for the development of aptamer molecular probes: A comprehensive review

BACKGROUND

Aptamers are screened via the systematic evolution of ligands by exponential enrichment (SELEX) and are widely used in molecular diagnostics and targeted therapies. The development of efficient and convenient SELEX technology has facilitated rapid access to high-performance aptamers, thereby advancing the aptamer industry. Graphene oxide (GO) serves as an immobilization matrix for libraries in GO-SELEX, making it suitable for screening aptamers against diverse targets.

RESULTS

This review summarizes the detailed steps involved in GO-SELEX, including monitoring methods, various sublibrary acquisition methods, and practical applications from its inception to the present day. In addition, the potential of GO-SELEX in the development of broad-spectrum aptamers is explored, and its current limitations for future development are emphasized. This review effectively promotes the application of the GO-SELEX technique by providing valuable insights and assisting researchers interested in conducting related studies.

SIGNIFICANCE AND NOVELTY

To date, no review on the topic of GO-SELEX has been published, making it challenging for researchers to initiate studies in this area. We believe that this review will broaden the SELEX options available to researchers, ensuring that they can meet the growing demand for molecular probes in the scientific domain.

Curcumin inhibits PAT-induced renal ferroptosis via the p62/Keap1/Nrf2 signalling pathway

Patulin (PAT), the most common mycotoxin, is widespread in foods and beverages which poses a serious food safety issue to human health. Our previous research confirmed that exposure to PAT can lead to acute kidney injury (AKI). Curcumin is the most abundant active ingredient in turmeric rhizome with various biological activities. The aim of this study is to investigate whether curcumin can prevent the renal injury caused by PAT, and to explore potential mechanisms. In vivo, supplementation with curcumin attenuated PAT-induced ferroptosis. Mechanically, curcumin inhibited autophagy, led to the accumulation of p62 and its interaction with Keap1, promoted the nuclear translocation of nuclear factor E2 related factor 2 (Nrf2), and increased the expression of antioxidant stress factors in the process of ferroptosis. These results have also been confirmed in HKC cell experiments. Furthermore, knockdown of Nrf2 in HKC cells abrogated the protective effect of curcumin on ferroptosis. In conclusion, we confirmed that curcumin mitigated PAT-induced AKI by inhibiting ferroptosis via activation of the p62/Keap1/Nrf2 pathway. This study provides new potential targets and ideas for the prevention and treatment of PAT.

Patulin alters alpha-adrenergic receptor signalling and induces epigenetic modifications in the kidneys of C57BL/6 mice

Patulin (PAT) is a food-borne mycotoxin produced by Penicillium and Byssochlamys species. It is widely known for its mutagenic, carcinogenic, and genotoxic effects and has been associated with kidney injury; however, the mechanism of toxicity remains unclear. To address this gap, we conducted a study to explore the changes in α-adrenergic receptor signalling pathways and epigenetic modifications induced by PAT in the kidneys of C57BL/6 mice during acute (1 day) and prolonged (10 days) exposure. The mice (20-22 g) were orally administered PAT (2.5 mg/kg; at 1 and 10 days), and post-treatment, the kidneys were harvested, homogenised and extracted for RNA, DNA, and protein. The relative gene expression of the α-adrenergic receptors (ADRA1, ADRA2A, ADRA2B) and associated signalling pathways (MAPK, MAPK14, ERK, PI3K, and AKT) was assessed by qPCR. The protein expression of ERK1/2 and MAPK was determined by western blot. The impact of PAT on DNA methylation was evaluated by quantifying global DNA methylation; qPCR was used to determine gene expression levels of DNA methyltransferases (DNMT1, DNMT3A, and DNMT3B) and demethylase (MBD2). PAT downregulated the expression of ADRA1, ADRA2A, ADRA2B, PI3K, and AKT and upregulated ERK1/2 and MAPK protein expression. Furthermore, PAT induced alterations in DNA methylation patterns by upregulating DNMT1 and MBD2 expressions and downregulating DNMT3A and DNMT3B expressions, resulting in global DNA hypomethylation. In conclusion, PAT disrupts α-1 and α-2 adrenergic receptor signalling pathways and induces epigenetic modifications, that can lead to kidney injury.

Recent advances of fermented fruits: A review on strains, fermentation strategies, and functional activities

Fruits are recognized as healthy foods with abundant nutritional content. However, due to their high content of sugar and water, they are easily contaminated by microorganisms leading to spoilage. Probiotic fermentation is an effective method to prevent fruit spoilage. In addition, during fermentation, the probiotics can react with the nutrients in fruits to produce new derived compounds, giving the fruit specific flavor, enhanced color, active ingredients, and nutritional values. Noteworthy, the choice of fermentation strains and strategies has a significant impact on the quality of fermented fruits. Thus, this review provides comprehensive information on the fermentation strains (especially yeast, lactic acid bacteria, and acetic acid bacteria), fermentation strategies (natural or inoculation fermentation, mono- or mixed-strain inoculation fermentation, and liquid- or solid-state fermentation), and the effect of fermentation on the shelf life, flavor, color, functional components, and physiological activities of fruits. This review will provide a theoretical guidance for the production of fermented fruits.

International consensus guidelines for the definition, detection, and interpretation of autophagy-dependent ferroptosis

Macroautophagy/autophagy is a complex degradation process with a dual role in cell death that is influenced by the cell types that are involved and the stressors they are exposed to. Ferroptosis is an iron-dependent oxidative form of cell death characterized by unrestricted lipid peroxidation in the context of heterogeneous and plastic mechanisms. Recent studies have shed light on the involvement of specific types of autophagy (e.g. ferritinophagy, lipophagy, and clockophagy) in initiating or executing ferroptotic cell death through the selective degradation of anti-injury proteins or organelles. Conversely, other forms of selective autophagy (e.g. reticulophagy and lysophagy) enhance the cellular defense against ferroptotic damage. Dysregulated autophagy-dependent ferroptosis has implications for a diverse range of pathological conditions. This review aims to present an updated definition of autophagy-dependent ferroptosis, discuss influential substrates and receptors, outline experimental methods, and propose guidelines for interpreting the results.Abbreviation: 3-MA:3-methyladenine; 4HNE: 4-hydroxynonenal; ACD: accidentalcell death; ADF: autophagy-dependentferroptosis; ARE: antioxidant response element; BH2:dihydrobiopterin; BH4: tetrahydrobiopterin; BMDMs: bonemarrow-derived macrophages; CMA: chaperone-mediated autophagy; CQ:chloroquine; DAMPs: danger/damage-associated molecular patterns; EMT,epithelial-mesenchymal transition; EPR: electronparamagnetic resonance; ER, endoplasmic reticulum; FRET: Försterresonance energy transfer; GFP: green fluorescent protein;GSH: glutathione;IF: immunofluorescence; IHC: immunohistochemistry; IOP, intraocularpressure; IRI: ischemia-reperfusion injury; LAA: linoleamide alkyne;MDA: malondialdehyde; PGSK: Phen Green™ SK;RCD: regulatedcell death; PUFAs: polyunsaturated fatty acids; RFP: red fluorescentprotein;ROS: reactive oxygen species; TBA: thiobarbituricacid; TBARS: thiobarbituric acid reactive substances; TEM:transmission electron microscopy.

Involvement of multiple forms of cell death in patulin-induced toxicities

Patulin (PAT) is the most common mycotoxin found in moldy fruits and their derived products, and is reported to cause diverse toxic effects, including hepatotoxicity, nephrotoxicity, cardiotoxicity, neurotoxicity, immunotoxicity, gastrointestinal toxicity and dermal toxicity. The cell death induction by PAT is suggested to be a key cellular mechanism involved in PAT-induced toxicities. Accumulating evidence indicates that the multiple forms of cell death are induced in response to PAT exposure, including apoptosis, autophagic cell death, pyroptosis and ferroptosis. Mechanistically, the cell death induction by PAT is associated the oxidative stress induction via reducing the antioxidant capacity or inducing pro-oxidant NADPH oxidase, the activation of mitochondrial pathway via regulating BCL-2 family proteins, the disruption of iron metabolism through ferritinophagy-mediated ferritin degradation, and the induction of the NOD-like receptor (NLR) family pyrin domain containing 3 (NLRP3) inflammasome/caspase-1/gasdermin D (GSDMD) pathway. In this review article, we summarize the present understanding of the cell death induction by PAT, discuss the potential signaling pathways underlying PAT-induced cell death, and propose the issues that need to be addressed to promote the development of cell death-based approach to counteract PAT-induced toxicities.

Caffeine and neonatal acute kidney injury

Acute kidney injury is one of the most threatening diseases in neonates, with complex pathogenesis and limited treatment options. Caffeine is a commonly used central nervous system stimulant for treating apnea in preterm infants. There is compelling evidence that caffeine may have potential benefits for preventing neonatal acute kidney injury, but comprehensive reports are lacking in this area. Hence, this review aims to provide a summary of clinical data on the potential benefits of caffeine in improving neonatal acute kidney injury. Additionally, it delves into the molecular mechanisms underlying caffeine's effects on acute kidney injury, with a focus on various aspects such as oxidative stress, adenosine receptors, mitochondrial dysfunction, endoplasmic reticulum stress, inflammasome, autophagy, p53, and gut microbiota. The ultimate goal of this review is to provide information for healthcare professionals regarding the link between caffeine and neonatal acute kidney injury and to identify gaps in our current understanding.

Integrated transcriptomics and metabolomics reveal the mechanism of intestinal damage upon acute patulin exposure in mice

Mycotoxin contamination has become a major food safety issue and greatly threatens human and animal health. Patulin (PAT), a common mycotoxin in the environment, is exposed through the food chain and damages the gastrointestinal tract. However, its mechanism of enterotoxicity at the genetic and metabolic levels remains to be elucidated. Herein, the intestinal histopathological and biochemical indices, transcriptome, and metabolome of C57BL/6 J mice exposed to different doses of PAT were successively assessed, as well as the toxicokinetics of PAT in vivo. The results showed that acute PAT exposure induced damaged villi and crypts, reduced mucus secretion, decreased SOD and GSH-Px activities, and enhanced MPO activity in the small intestine and mild damage in the colon. At the transcriptional level, the genes affected by PAT were dose-dependently altered in the small intestine and fluctuated in the colon. PAT primarily affected inflammation-related signaling pathways and oxidative phosphorylation in the small intestine and immune responses in the colon. At the metabolic level, amino acids decreased, and extensive lipids accumulated in the small intestine and colon. Seven metabolic pathways were jointly affected by PAT in two intestinal sites. Moreover, changes in PAT products and GST activity were detected in the small intestinal tissue but not in the colonic tissue, explaining the different damage degrees of the two sites. Finally, the integrated results collectively explained the toxicological mechanism of PAT, which damaged the small intestine directly and the colon indirectly. These results paint a clear panorama of intestinal changes after PAT exposure and provide valuable information on the exposure risk and toxic mechanism of PAT.

Role of ferroptosis in food-borne mycotoxin-induced toxicities

Contamination by toxic substances is a major global food safety issue, which poses a serious threat to human health. Mycotoxins are major class of food contaminants, mainly including aflatoxins (AFs), zearalenone (ZON), deoxynivalenol (DON), ochratoxin A (OTA), fumonisins (FBs) and patulin (PAT). Ferroptosis is a newly identified iron-dependent form of programmed or regulated cell death, which has been found to be involved in diverse pathological conditions. Recently, a growing body of evidence has shown that ferroptosis is implicated in the toxicities induced by certain types of food-borne mycotoxins, which provides novel mechanistic insights into mycotoxin-induced toxicities and paves the way for developing ferroptosis-based strategy to combat against toxicities of mycotoxins. In this review article, we summarize the key findings on the involvement of ferroptosis in mycotoxin-induced toxicities and propose issues that need to be addressed in future studies for better utilization of ferroptosis-based approach to manage the toxic effects of mycotoxin contamination.

Novel Perspective on Mechanism in Muscle Growth Inhibited by Ochratoxin A Associated with Ferroptosis: Model of Juvenile Grass Carp (Ctenopharyngodon idella) In Vivo and In Vitro Trials

Ochratoxin A (OTA) is a common mycotoxin in food and feed that seriously harms human and animal health. This study investigated the effect of OTA on the muscle growth of juvenile grass carp (Ctenopharyngodon idella) and its possible mechanism in vitro. Our results have the following innovative findings: (1) Dietary OTA increased the expression of increasing phase I metabolic enzymes and absorbing transporters while reducing the expression of efflux transporters, thereby increasing their residue in muscles; (2) OTA inhibited the expressions of cell cycle and myogenic regulatory factors (MyoD, MyoG, and MyHC) and induced ferroptosis by decreasing the mRNA and protein expressions of FTH, TFR1, GPX4, and Nrf2 both in vivo and in vitro; and (3) the addition of DFO improved OTA-induced ferroptosis of grass carp primary myoblasts and promoted cell proliferation, while the addition of AKT improved OTA-inhibited myoblast differentiation and fusion, thus inhibiting muscle growth. Overall, this study provides a potential research target to further mitigate the myotoxicity of OTA.

Tetramethylpyrazine attenuates renal tubular epithelial cell ferroptosis in contrast-induced nephropathy by inhibiting transferrin receptor and intracellular reactive oxygen species

Contrast-induced nephropathy (CIN) is a leading cause of hospital-acquired acute kidney injury (AKI). Recently, ferroptosis was reported to be crucial for AKI pathogenesis. Our previous studies indicated antioxidant tetramethylpyrazine (TMP) prevent CIN in vivo. However, whether ferroptosis is involved in TMP nephroprotective mechanism against CIN is unclear. In the present study, we investigated the role of renal tubular epithelial cell ferroptosis in TMP reno-protective effect against CIN and the molecular mechanisms by which TMP regulates ferroptosis. Classical contrast-medium, Iohexol, was used to construct CIN models in rats and HK-2 cells. Results showed that tubular cell injury was accompanied by ferroptosis both in vivo and in vitro, including the typical features of ferroptosis, Fe2+ accumulation, lipid peroxidation and decreased glutathione peroxidase 4 (GPX4). Ferroptosis inhibition by classic inhibitors Fer-1 and DFO promoted cell viability and reduced intracellular ROS production. Additionally, TMP significantly inhibited renal dysfunction, reduced AKI biomarkers, prevented ROS production, inhibited renal Fe2+ accumulation and increased GPX4 expression. Expressions of various proteins associated with iron ion metabolism, including transferrin receptor (TFRC), divalent metal transporter 1, iron-responsive element binding protein 2, ferritin heavy chain 1, ferroportin 1, and heat shock factor binding protein 1, were examined using mechanistic analyses. Among these, TFRC changes were the most significant after TMP pretreatment. Results of siRNA knockdown and plasmid overexpression of TFRC indicated that TFRC is essential for TMP to alleviate ferroptosis and reduce LDH release, Fe2+ accumulation and intracellular ROS. Our findings provide crucial insights about the potential of TMP in treating AKI associated with ferroptosis.

Elaborate cooperation of poly(rC)-binding proteins 1/2 and glutathione in ferroptosis induced by plasma-activated Ringer's lactate

Reactive species are involved in various aspects of neoplastic diseases, including carcinogenesis, cancer-specific metabolism and therapeutics. Non-thermal plasma (NTP) can directly provide reactive species, by integrating atmospheric and interjacent molecules as substrates, to represent a handy strategy to load oxidative stress in situ. NTP causes apoptosis and/or ferroptosis specifically in cancer cells of various types. Plasma-activated Ringer's lactate (PAL) is another modality at the preclinical stage as cancer therapeutics, based on more stable reactive species. PAL specifically kills malignant mesothelioma (MM) cells, employing lysosomal ·NO as a switch from autophagy to ferroptosis. However, the entire molecular mechanisms have not been elucidated yet. Here we studied cytosolic iron regulations in MM and other cancer cells in response to PAL exposure. We discovered that cells with higher catalytic Fe(II) are more susceptible to PAL-induced ferroptosis. PAL caused a cytosolic catalytic Fe(II)-associated pathology through iron chaperones, poly (rC)-binding proteins (PCBP)1/2, inducing a disturbance in glutathione-regulated iron homeostasis. PCBP1/NCOA4-mediated ferritinophagy started at a later phase, further increasing cytosolic catalytic Fe(II), ending in ferroptosis. In contrast, PCBP2 after PAL exposure contributed to iron loading to mitochondria, leading to mitochondrial dysfunction. Therapeutic effect of PAL was successfully applied to an orthotopic MM xenograft model in mice. In conclusion, PAL can selectively sensitize MM cells to ferroptosis by remodeling cytoplasmic iron homeostasis, where glutathione and PCBPs play distinct roles, resulting in lethal ferritinophagy and mitochondrial dysfunction. Our findings indicate the clinical application of PAL as a ferroptosis-inducer and the potential of PCBPs as novel targets in cancer therapeutics.

Ochratoxin A Induces Renal Cell Ferroptosis by Disrupting Iron Homeostasis and Increasing ROS

Mycotoxin ochratoxin A (OTA) is a critical food safety concern due to its nephron-toxic effects and is detected in a wide range of food and feedstuffs. OTA nephrotoxicity is related to oxidative stress and damage. However, the mediator(s) of the excessive oxidative stress is unclear. The current study used human kidney cell lines to investigate whether and how intracellular iron contributed to OTA-induced ROS accumulation and how OTA-induced iron-dependent ferroptotic cell death. Our results showed that OTA treatment affected the cell viability and induced the typical characteristics of cell ferroptosis. Furthermore, gene and protein expression results indicated that OTA disrupted iron homeostasis by upregulating the expression levels of iron importer TFR1 and FTH, while downregulating the expression level of iron exporter FPN and dramatically increasing its negative regulator Hepcidin. The changes were consistent with the induction of intracellular iron accumulation and elevated levels of oxidative stress and lipid peroxidation. Additionally, co-treatment with OTA and an iron chelator significantly improved cell viability, reduced cellular total iron and ROS, and reversed OTA-induced changes in iron metabolism gene expression levels. Interestingly, the addition of a ROS scavenger also reversed cell death and changes in mRNA and protein expression levels of iron metabolism genes but to a lesser degree than that of the iron-chelating agent. Our results revealed that OTA induced ferroptosis in renal cells by disrupting iron homeostasis and increasing ROS.

Ferritinophagy Mediated by Oxidative Stress-Driven Mitochondrial Damage Is Involved in the Polystyrene Nanoparticles-Induced Ferroptosis of Lung Injury

Nanoplastics are a common type of contaminant in the air. However, no investigations have focused on the toxic mechanism of lung injury induced by nanoplastic exposure. In the present study, polystyrene nanoplastics (PS-NPs) caused ferroptosis in lung epithelial cells, which could be alleviated by ferrostatin-1, deferoxamine, and N-acetylcysteine. Further investigation found that PS-NPs disturbed mitochondrial structure and function and triggered autophagy. Mechanistically, oxidative stress-derived mitochondrial damage contributed to ferroptosis, and autophagy-dependent ferritinophagy was a pivotal intermediate link, resulting in ferritin degradation and iron ion release. Furthermore, inhibition of ferroptosis using ferrostatin-1 alleviated pulmonary and systemic toxicity to reverse the mouse lung injury induced by PS-NPs inhalation. Most importantly, the lung-on-a-chip was further used to clarify the role of ferroptosis in the PS-NPs-induced lung injury by visualizing the ferroptosis, oxidative stress, and alveolar-capillary barrier dysfunction at the organ level. In summary, our study indicated that ferroptosis was an important mechanism for nanoplastics-induced lung injury through different lung cells, mouse inhalation models, and three-dimensional-based lung-on-a-chip, providing an insightful reference for pulmonary toxicity assessment of nanoplastics.

NCOA4-mediated ferritinophagy aggravate intestinal oxidative stress and ferroptosis after traumatic brain injury

Intestinal injury caused by traumatic brain injury (TBI) seriously affects patient prognosis; however, the underlying mechanisms are unknown. Recent studies have demonstrated that ferritinophagy-mediated ferroptosis is involved in several intestinal disorders. However, uncertainty persists regarding the role of ferritinophagy-mediated ferroptosis in the intestinal damage caused by TBI. High-throughput transcriptional sequencing was used to identify the genes that were differentially expressed in the intestine after TBI. The intestinal tissues were harvested for hematoxylin and eosin staining (HE), immunofluorescence, and western blot (WB). Lipid peroxide markers and iron content in the intestines were determined using the corresponding kits. High throughput sequencing revealed that the ferroptosis signaling pathway was enriched, demonstrating that intestinal damage caused by TBI may include ferroptosis. Chiu's score, tight junction proteins, and lipid peroxide indicators demonstrated that TBI caused an intestinal mucosal injury that persisted for several days. The ferroptosis pathway-related proteins, ferritin heavy polypeptide 1 (Fth1) and glutathione peroxidase 4 (GPX4), exhibited dynamic changes. The results indicated that lipid peroxide products were markedly increased, whereas antioxidant enzymes were markedly decreased. WB analysis demonstrated that the expression levels of nuclear receptor coactivator 4 (NCOA4), LC3II/LC3I, and p62 were markedly upregulated, whereas those of GPX4 and Fth1 were markedly downregulated. In addition, ferrostatin-1 attenuates intestinal ferroptosis and injury post-TBI in vivo. Intriguingly, 3-methyladenine (3-MA) reduces intestinal ferritin decomposition, iron accumulation, and ferroptosis after TBI. Moreover, 3-MA markedly reduced intestinal apoptosis. In conclusion, NCOA4 mediated ferritinophagy and ferroptosis play roles in intestinal oxidative stress injury post-TBI. This study provides a deeper understanding of the mechanisms underlying intestinal damage following TBI.

Global research trends and hot spots on autophagy and kidney diseases: a bibliometric analysis from 2000 to 2022

Background: Autophagy is an essential cellular process involving the self-degradation and recycling of organelles, proteins, and cellular debris. Recent research has shown that autophagy plays a significant role in the occurrence and development of kidney diseases. However, there is a lack of bibliometric analysis regarding the relationship between autophagy and kidney diseases. Methods: A bibliometric analysis was conducted by searching for literature related to autophagy and kidney diseases in the Web of Science Core Collection (WoSCC) database from 2000 to 2022. Data processing was carried out using R package "Bibliometrix", VOSviewers, and CiteSpace. Results: A total of 4,579 articles related to autophagy and kidney diseases were collected from various countries. China and the United States were the main countries contributing to the publications. The number of publications in this field showed a year-on-year increasing trend, with open-access journals playing a major role in driving the literature output. Nanjing Medical University in China, Osaka University in Japan, and the University of Pittsburgh in the United States were the main research institutions. The journal "International journal of molecular sciences" had the highest number of publications, while "Autophagy" was the most influential journal in the field. These articles were authored by 18,583 individuals, with Dong, Zheng; Koya, Daisuke; and Kume, Shinji being the most prolific authors, and Dong, Zheng being the most frequently co-cited author. Research on autophagy mainly focused on diabetic kidney diseases, acute kidney injury, and chronic kidney disease. "Autophagy", "apoptosis", and "oxidative stress" were the primary research hotspots. Topics such as "diabetic kidney diseases", "sepsis", "ferroptosis", "nrf2", "hypertension" and "pi3k" may represent potential future development trends. Research on autophagy has gradually focused on metabolic-related kidney diseases such as diabetic nephropathy and hypertension. Additionally, PI3K, NRF2, and ferroptosis have been recent research directions in the field of autophagy mechanisms. Conclusion: This is the first comprehensive bibliometric study summarizing the relationship between autophagy and kidney diseases. The findings aid in identifying recent research frontiers and hot topics, providing valuable references for scholars investigating the role of autophagy in kidney diseases.

Visualization detection of mycotoxin patulin in fruit juices by a small-molecule fluorescent probe

The mycotoxin patulin is a common contaminant in rotten fruits, posing severe food safety risks and threats to human health. Developing a convenient, sensitive and reliable method for patulin detection is of utmost importance but remains challenging. In this study, we have successfully designed and synthesized a small-molecule fluorescent probe, FITC-Lys, which demonstrates good sensitivity in detecting patulin. Upon contact with patulin, the terminal Lys group of the FITC-Lys probe reacts with patulin, resulting in the formation of the fluorescein dimer that subsequently quenches fluorescence. This variation of fluorescence enables the visualization and sensitive detection of patulin. The probe exhibits good sensitivity with a low LOD of 8 ng mL-1 for the fluorescence spectrum method and a LOD of 12 ng mL-1 for the fluorescence imaging method. Moreover, we have validated the probe's capability for patulin detection in apple and pear juices, achieving good recoveries ranging from 98.60% to 103.80%. Notably, the probe FITC-Lys is the first small-molecule fluorescent probe that has proven successful in visualizing patulin in juices derived from decayed apples and pears. Consequently, this probe holds great potential as a practical tool for monitoring patulin in foodstuffs, thereby contributing to enhanced food safety standards.

Farnesoid X Receptor Plays a Key Role in Ochratoxin A-Induced Nephrotoxicity by Targeting Ferroptosis In Vivo and In Vitro

The mycotoxin ochratoxin A (OTA) causes nephrotoxicity, hepatotoxicity, and immunotoxicity in animals and humans. The farnesoid X receptor (FXR) is a member of the NR family and is highly expressed in the kidney, which has an antilipid production function. Ferroptosis is an iron-dependent form of regulated cell death involved in several pathophysiological cell death and kidney injury. The present study aims to evaluate the role of FXR and ferroptosis in OTA-induced nephrotoxicity in mice and HK-2 cells. Results showed that OTA induced nephrotoxicity as demonstrated by inducing the histopathological lesions and neutrophil infiltration of the kidney, increasing serum BUN, CRE, and UA levels, increasing Ntn-1, Kim-1, and pro-inflammatory cytokine expression, and decreasing IL-10 expression and the cell viability of HK-2 cells. OTA treatment also induced FXR deficiency, ROS release, MDA level increase, GSH content decrease, and 4-HNE production in the kidney and HK-2 cells. OTA treatment induced ferroptosis as demonstrated by increasing labile iron pool and lipid peroxidation levels as well as Acsl4, TFR1, and HO-1 mRNA and protein levels, decreasing GPX4 and FTH mRNA and protein expressions, and inducing mitochondrial injury. The FXR activator (GW4064) rescued the accumulation of lipid peroxides, intracellular ROS, and Fe2+, inhibited ferroptosis, and alleviated OTA-induced nephrotoxicity. The ferroptosis inhibitor (Fer-1) prevented ferroptosis and attenuated nephrotoxicity. Collectively, this study elucidates that FXR played a critical role in OTA-induced nephrotoxicity via regulation of ferroptosis, which provides a novel strategy against OTA-induced nephrotoxicity.

Emerging significance and therapeutic targets of ferroptosis: a potential avenue for human kidney diseases

Kidney diseases remain one of the leading causes of human death and have placed a heavy burden on the medical system. Regulated cell death contributes to the pathology of a plethora of renal diseases. Recently, with in-depth studies into kidney diseases and cell death, a new iron-dependent cell death modality, known as ferroptosis, has been identified and has attracted considerable attention among researchers in the pathogenesis of kidney diseases and therapeutics to treat them. The majority of studies suggest that ferroptosis plays an important role in the pathologies of multiple kidney diseases, such as acute kidney injury (AKI), chronic kidney disease, and renal cell carcinoma. In this review, we summarize recently identified regulatory molecular mechanisms of ferroptosis, discuss ferroptosis pathways and mechanisms of action in various kidney diseases, and describe the protective effect of ferroptosis inhibitors against kidney diseases, especially AKI. By summarizing the prominent roles of ferroptosis in different kidney diseases and the progress made in studying ferroptosis, we provide new directions and strategies for future research on kidney diseases. In summary, ferroptotic factors are potential targets for therapeutic intervention to alleviate different kidney diseases, and targeting them may lead to new treatments for patients with kidney diseases.

Ferritinophagy activation and sideroflexin1-dependent mitochondrial iron overload contribute to patulin-induced cardiac inflammation and fibrosis

Patulin (PAT) is a mycotoxin that is commonly present throughout the ecosystem where fungi grow and mainly contaminates food, soil, and water. PAT was found to be cardiotoxic in previous studies. However, the detailed mechanism has not been fully elucidated. The present study aimed to explore the role and underlying mechanism of ferroptosis in PAT-induced cardiac injury. Here, we confirmed in vivo and in vitro that ferroptosis is involved in PAT-induced myocardial inflammation and fibrosis. Mice exposed to PAT (1 and 2 mg/kg body weight/day for 14 days) exhibited myocardial inflammation and fibrosis along with disrupted iron homeostasis, elevated lipid peroxidation, depletion of glutathione peroxidase 4, and abnormal mitochondrial morphology. When primary neonatal rat cardiomyocytes (NRCMs) and H9c2 cells were exposed to PAT, ferroptosis was initiated in a dose-dependent manner, and this process could be significantly attenuated by ferrostatin-1. Mechanistically, we found that nuclear receptor coactivator (NCOA) 4, a master regulator of ferritinophagy, bound to and degraded ferritin in response to PAT treatment, thereby releasing large amounts of ferrous iron and further leading to sideroflexin (SFXN) 1-dependent mitochondrial iron overload. Conversely, knockdown of NCOA4 or SFXN1 with small interfering RNAs could effectively ameliorate ferroptotic cell death, cellular or mitochondrial iron overload and lipid peroxides accumulation. Furthermore, myocardial inflammation and fibrosis in PAT-exposed mice was alleviated by the mitochondrial iron chelator deferiprone. Overall, our findings underscore that ferritinophagy activation and SFXN1-dependent mitochondrial iron overload play critical roles in PAT-induced myocardial ferroptosis and consequent cardiotoxicity.

HP1 induces ferroptosis of renal tubular epithelial cells through NRF2 pathway in diabetic nephropathy

The aim of this study was to investigate the role of ferroptosis in diabetic nephropathy (DN) and the mechanism of its regulatory genes. HK-2 cells were cultured with high glucose and mice were intraperitoneally injected with streptozotocin to establish DN models. GSE111154 was analyzed to identify the abnormal expression of genes associated with DN. Cell injury was evaluated through CCK-8 assay and 4',6-diamidino-2-phenylindole/phenylindole double staining. The levels of iron, glutathione, malondialdehyde, urinary albumin, and urinary creatinine were determined by ELISA. Furthermore, western blot and RT-qPCR were used to detect protein and mRNA levels, respectively. Our data showed that heterochromatin protein 1 is an abnormally elevated gene related to DN and is further elevated by ferroptosis activators. Inhibition of HP1 significantly inhibited ferroptosis but promoted cell viability. In addition, nuclear factor erythroid2-related factor2 (NRF2) was decreased in DN cell model, but increased under the action of ferroptosis activators. NRF2 silencing reversed the protective effects of HP1 inhibition on HK-2 cells. Additionally, HP1 silencing also alleviated kidney damage in DN mice. Collectively, these findings suggest that inhibiting HP1 inhibits ferroptosis via NRF2 pathway, thereby protecting renal tubular epithelial cells from damage.

Novel Insight into Ferroptosis in Kidney Diseases

BACKGROUND

Various kidney diseases such as acute kidney injury, chronic kidney disease, polycystic kidney disease, renal cancer, and kidney stones, are an important part of the global burden, bringing a huge economic burden to people around the world. Ferroptosis is a type of nonapoptotic iron-dependent cell death caused by the excess of iron-dependent lipid peroxides and accompanied by abnormal iron metabolism and oxidative stress. Over the past few decades, several studies have shown that ferroptosis is associated with many types of kidney diseases. Studying the mechanism of ferroptosis and related agonists and inhibitors may provide new ideas and directions for the treatment of various kidney diseases.

SUMMARY

In this review, we discuss the differences between ferroptosis and other types of cell death such as apoptosis, necroptosis, pyroptosis, cuprotosis, pathophysiological features of the kidney, and ferroptosis-induced kidney injury. We also provide an overview of the molecular mechanisms involved in ferroptosis and events that lead to ferroptosis. Furthermore, we summarize the possible clinical applications of this mechanism among various kidney diseases.

KEY MESSAGE

The current research suggests that future therapeutic efforts to treat kidney ailments would benefit from a focus on ferroptosis.

Quercetin Alleviates Acrylamide-Induced Liver Injury by Inhibiting Autophagy-Dependent Ferroptosis

Acrylamide (ACR) generated in carbohydrate-rich foods during thermal processing has been demonstrated to exhibit hepatotoxicity. As one of the most consumed flavonoids with diet, quercetin (QCT) possesses the ability to protect against ACR-induced toxicity, albeit its mechanism is unclear. Herein, we discovered that QCT alleviated ACR-induced elevated levels of reactive oxygen species (ROS), AST, and ALT in mice. RNA-seq analysis revealed that QCT reversed the ferroptosis signaling pathway upregulated by ACR. Subsequently, experiments indicated that QCT inhibited ACR-induced ferroptosis through the reduction of oxidative stress. With autophagy inhibitor chloroquine, we further confirmed that QCT suppressed ACR-induced ferroptosis by inhibiting oxidative stress-driven autophagy. Additionally, QCT specifically reacted with autophagic cargo receptor NCOA4, blocked the degradation of iron storage protein FTH1, and eventually downregulated the intracellular iron levels and the consequent ferroptosis. Collectively, our results presented a unique approach to alleviate ACR-induced liver injury by targeting ferroptosis with QCT.

Ferroptosis as a Potential Therapeutic Target of Traditional Chinese Medicine for Mycotoxicosis: A Review

Mycotoxin contamination has become one of the biggest hidden dangers of food safety, which seriously threatens human health. Understanding the mechanisms by which mycotoxins exert toxicity is key to detoxification. Ferroptosis is an adjustable cell death characterized by iron overload and lipid reactive oxygen species (ROS) accumulation and glutathione (GSH) depletion. More and more studies have shown that ferroptosis is involved in organ damage from mycotoxins exposure, and natural antioxidants can alleviate mycotoxicosis as well as effectively regulate ferroptosis. In recent years, research on the treatment of diseases by Chinese herbal medicine through ferroptosis has attracted more attention. This article reviews the mechanism of ferroptosis, discusses the role of ferroptosis in mycotoxicosis, and summarizes the current status of the regulation of various mycotoxicosis through ferroptosis by Chinese herbal interventions, providing a potential strategy for better involvement of Chinese herbal medicine in the treatment of mycotoxicosis in the future.

Ferrostatin-1 alleviates cerebral ischemia/reperfusion injury through activation of the AKT/GSK3β signaling pathway

Ischemic stroke is the major cause of disability and death worldwide, but post-stroke neuronal death and related mechanisms remain unclear. Ferroptosis, a newly identified type of regulated cell death, has been shown to be associated with neurological disorders, yet the exact relationship between ferroptosis and ischemic stroke has not been elucidated. The purpose of this study is to investigate the effects of ferroptosis-specific inhibitor ferrostatin-1 (Fer-1) on neuronal injury after cerebral ischemia/reperfusion (I/R) and the underlying mechanism. In this study, we demonstrated that ferroptosis does occur in the stroke model. We found that Fer-1 reduced the levels of iron and malondialdehyde, and increased the content of glutathione and the expression of solute carrier family 7 member 11 and glutathione peroxidase 4 in cerebral I/R models. Additionally, Fer-1 significantly reduced the infarct volume and improved neurobehavioral outcomes. Moreover, we found that Fer-1 increased the levels of phosphorylated AKT and GSK3β following cerebral I/R. To further investigate the functional role of the AKT in the neuroprotective effects of Fer-1, MCAO models and oxygen-glucose deprivation-induced HT22 cells were pretreated with the AKT inhibitor MK-2206 before treatment with Fer-1 and the protective effects of Fer-1 were reversed. In conclusion, Fer-1 has protective effects on cerebral I/R injury by activating the AKT/GSK3β pathway, indicating that ferroptosis may become a novel target in the treatment of ischemic stroke.

Lycopene alleviates multiple-mycotoxin-induced toxicity by inhibiting mitochondrial damage and ferroptosis in the mouse jejunum

Multiple mycotoxins contamination in foods and feeds threatens human and animal health after they accumulate in the food chain, producing various toxic effects. The common mycotoxins contaimination in feeds are zearalenone (ZEN), deoxynivalenol (DON), and aflatoxin B1 (AFB1), but the effects of their co-exposure on the jejunum are not well understood. Lycopene (LYC) has been reported to have antioxidant activity that alleviates jejunal damage. In this study, we investigated the possible role of LYC as a treatment to mitigate the combined effects of ZEN, DON, and AFB1 on the jejunum of mice. Eighty male specific-pathogen-free ICR mice were randomly allocated to treatments with LYC (10 mg kg-1) and/or ZEN + DON + AFB1 (10 mg kg-1 ZEN, 1 mg kg-1 DON, and 0.5 mg kg-1 AFB1). The results indicated that LYC alleviated ZEN + DON + AFB1-induced jejunal injury by ameliorating the jejunal structural injury and increasing the villus height/crypt depth ratio and the levels of tight junction proteins (zonula occludens 1 [ZO1], occludin1 and claudin1) in the mouse jejunum. LYC also inhibited the oxidative stress induced by co-exposure to ZEN, DON, and AFB1 via reducing the levels of reactive oxygen species (ROS) and malondialdehyde (MDA) and enhancing the total antioxidant capacity (T-AOC). LYC also alleviated jejunal mitochondrial damage in the ZEN + DON + AFB1-affected mice, evident as an increase in mitochondrial fission 1 (Fis1) transcription and a reduction in mitochondrial mitofusin 1 (Mfn1) and Mfn2 transcription. Co-exposure to ZEN, DON, and AFB1 also significantly increased the transcription of ferroptosis-related genes (transferrin receptor 1 (Tfr1), ferritin heavy chain 1 [Fth1], solute carrier family 3 member 2 [Slc3a2], and glutathione peroxidase 4 [Gpx4]), TFR1 and Fe2+ concentration. Notably, LYC potentially alleviated ZEN + DON + AFB1-induced jejunal ferroptosis. These results demonstrate that LYC alleviates ZEN + DON + AFB1-induced jejunal toxicity by inhibiting oxidative stress-mediated ferroptosis and mitochondrial damage in mice.