Exogenous Iron Induces NADPH Oxidases-Dependent Ferroptosis in the Conidia of Aspergillus flavus

The multifaceted role of ferroptosis in infection and injury and its nutritional regulation in pigs

Ferroptosis is a newly identified form of regulated cell death (RCD) characterized by iron overload and excessive lipid peroxidation. To date, numerous studies in human and mouse models have shown that ferroptosis is closely related to tissue damage and various diseases. In recent years, ferroptosis has also been found to play an indispensable and multifaceted role in infection and tissue injury in pigs, and nutritional regulation strategies targeting ferroptosis show great potential. In this review, we summarize the research progress of ferroptosis and its role in infection and tissue injury in pigs. Furthermore, we discuss the existing evidence on ferroptosis regulation by nutrients, aiming to provide valuable insights for future investigation into ferroptosis in pigs and offer a novel perspective for the treatment of infection and injury in pigs.

Ultrasound combined with FeSO4 facilitated the occurrence of ferroptosis in Vibrio parahaemolyticus

Ultrasound (US) as a sustainable non-thermal sterilization technology that is employed either independently alone or in combination with other processing methods to eliminate food-borne pathogens in the food industry. In the present study, the synergistic effects of US combined with FeSO4 against Vibrio parahaemolyticus were investigated. The results demonstrated that the combination of ultrasound and FeSO4 had an excellent bactericidal activity on V. parahaemolyticus. Treatment with US (100 W) and FeSO4 (8 μM) for 15 min could kill more than 99.9 % cells. Furthermore, the observed cell death was identified as classical ferroptosis, characterized by ferroptosis hallmarks including iron-dependent, ROS burst, membrane damage and lipid peroxide accumulation. Addition of ferroptosis inhibitor liproxstatin-1 alleviated the cell death induced by the combination treatment. Transcriptome analysis further revealed that the US-FeSO4 treatment significantly influenced pathways related to fatty acid metabolism, ferroptosis, biofilm formation, RNA degradation, oxidative phosphorylation and other key processes, which likely contributed to the occurrence of ferroptosis. Based on these findings, we speculated that cavitation effect of US promoted the entry of Fe2+, leading to the generation of free radicals primarily responsible for ferroptosis by US-FeSO4. Taken together, this study provides valuable insights into the biological pathway involved in ultrasound sterilization and presents an alternative strategy to eradicate microorganism in food products.

Candida albicans pathways that protect against organic peroxides and lipid peroxidation

Human fungal pathogens must survive diverse reactive oxygen species (ROS) produced by host immune cells that can oxidize a range of cellular molecules including proteins, lipids, and DNA. Formation of lipid radicals can be especially damaging, as it leads to a chain reaction of lipid peroxidation that causes widespread damage to the plasma membrane. Most previous studies on antioxidant pathways in fungal pathogens have been conducted with hydrogen peroxide, so the pathways used to combat organic peroxides and lipid peroxidation are not well understood. The most well-known peroxidase in Candida albicans, catalase, can only act on hydrogen peroxide. We therefore characterized a family of four glutathione peroxidases (GPxs) that were predicted to play an important role in reducing organic peroxides. One of the GPxs, Gpx3 is also known to activate the Cap1 transcription factor that plays the major role in inducing antioxidant genes in response to ROS. Surprisingly, we found that the only measurable role of the GPxs is activation of Cap1 and did not find a significant role for GPxs in the direct detoxification of peroxides. Furthermore, a CAP1 deletion mutant strain was highly sensitive to organic peroxides and oxidized lipids, indicating an important role for antioxidant genes upregulated by Cap1 in protecting cells from organic peroxides. We identified GLR1 (Glutathione reductase), a gene upregulated by Cap1, as important for protecting cells from oxidized lipids, implicating glutathione utilizing enzymes in the protection against lipid peroxidation. Furthermore, an RNA-sequencing study in C. albicans showed upregulation of a diverse set of antioxidant genes and protein damage pathways in response to organic peroxides. Overall, our results identify novel mechanisms by which C. albicans responds to oxidative stress resistance which open new avenues for understanding how fungal pathogens resist ROS in the host.

Thymol Induces Fenton-Reaction-Dependent Ferroptosis in Vibrio parahemolyticus

Thymol has efficient bactericidal activity against a variety of pathogenic bacteria, but the bactericidal mechanism against Vibrio parahemolyticus (V. parahemolyticus) has rarely been reported. In the current study, we investigated the bactericidal mechanism of thymol against V. parahemolyticus. The Results revealed that 150 μg/mL of thymol had 99.9% bactericidal activity on V. parahemolyticus. Intracellular bursts of reactive oxygen species (ROS), Fe2+accumulation, lipid peroxidation, and DNA breakage were checked by cell staining. The exogenous addition of H2O2 and catalase promoted and alleviated thymol-induced cell death to a certain extent, respectively, and the addition of the ferroptosis inhibitor Liproxstatin-1 also alleviated thymol-induced cell death, confirming that thymol induced Fenton-reaction-dependent ferroptosis in V. parahemolyticus. Proteomic analysis revealed that relevant proteins involved in ROS production, lipid peroxidation accumulation, and DNA repair were significantly upregulated after thymol treatment. Molecular docking revealed two potential binding sites (amino acids 46H and 42F) between thymol and ferritin, and thymol could promote the release of Fe2+ from ferritin proteins through in vitro interactions analyzed. Therefore, we hypothesized that ferritin as a potential target may mediate thymol-induced ferroptosis in V. parahemolyticus. This study provides new ideas for the development of natural inhibitors for controlling V. parahemolyticus in aquatic products.

Ferrous sulphate triggers ferroptosis in Candida albicans and cures vulvovaginal candidiasis in a mouse model

Candida albicans is the most leading cause of life-threatening fungal invasive infections, especially for vulvovaginal candidiasis (VVC). Resistance and tolerance to common fungicide has risen great demands on alternative strategies for treating C. albicans infections. In the present study, ferroptosis has been proven to occur in C. albicans by directly exposed to FeSO4 via induing hallmarks of ferroptosis, including Fe2+ overload burden, ROS eruption and lipid peroxidation. Transcriptomic profile gave the great hints of the possible mechanism for fungal ferroptosis that FeSO4 disturb pathways associated to ribosome, tyrosine metabolism, triglyceride metabolism and thiamine metabolism, thus mobilizing death-related gene synthesis. Inspired by the results, a FeSO4-loaded hydrogel was prepared as an antifungal agent to treat C. albicans infection. This hydrogel exhibited excellent dressing properties and maintained superior antifungal activity by characterization tests. Besides, mice treated by this composite hydrogel displayed excellent therapeutic efficacy. These results highlighted the potential therapeutic use of FeSO4 as an innovative strategy in treating C. albicans infections by targeting ferroptosis.

Ferroptosis in ulcerative colitis: Potential mechanisms and promising therapeutic targets

Ulcerative colitis (UC) is a complex immune-mediated chronic inflammatory bowel disease. It is mainly characterized by diffuse inflammation of the colonic and rectal mucosa with barrier function impairment. Identifying new biomarkers for the development of more effective UC therapies remains a pressing task for current research. Ferroptosis is a newly identified form of regulated cell death characterized by iron-dependent lipid peroxidation. As research deepens, ferroptosis has been demonstrated to be involved in the pathological processes of numerous diseases. A growing body of evidence suggests that the pathogenesis of UC is associated with ferroptosis, and the regulation of ferroptosis provides new opportunities for UC treatment. However, the specific mechanisms by which ferroptosis participates in the development of UC remain to be more fully and thoroughly investigated. Therefore, in this review, we focus on the research advances in the mechanism of ferroptosis in recent years and describe the potential role of ferroptosis in the pathogenesis of UC. In addition, we explore the underlying role of the crosslinked pathway between ferroptosis and other mechanisms such as macrophages, neutrophils, autophagy, endoplasmic reticulum stress, and gut microbiota in UC. Finally, we also summarize the potential compounds that may act as ferroptosis inhibitors in UC in the future.

Lycopene as a Therapeutic Agent against Aflatoxin B1-Related Toxicity: Mechanistic Insights and Future Directions

Aflatoxin (AFT) contamination poses a significant global public health and safety concern, prompting widespread apprehension. Of the various AFTs, aflatoxin B1 (AFB1) stands out for its pronounced toxicity and its association with a spectrum of chronic ailments, including cardiovascular disease, neurodegenerative disorders, and cancer. Lycopene, a lipid-soluble natural carotenoid, has emerged as a potential mitigator of the deleterious effects induced by AFB1 exposure, spanning cardiac injury, hepatotoxicity, nephrotoxicity, intestinal damage, and reproductive impairment. This protective mechanism operates by reducing oxidative stress, inflammation, and lipid peroxidation, and activating the mitochondrial apoptotic pathway, facilitating the activation of mitochondrial biogenesis, the endogenous antioxidant system, and the nuclear factor erythroid 2-related factor 2 (Nrf2)/kelch-like ECH-associated protein 1 (KEAP1) and peroxisome proliferator-activated receptor-γ coactivator-1 (PGC-1) pathways, as well as regulating the activities of cytochrome P450 (CYP450) enzymes. This review provides an overview of the protective effects of lycopene against AFB1 exposure-induced toxicity and the underlying molecular mechanisms. Furthermore, it explores the safety profile and potential clinical applications of lycopene. The present review underscores lycopene's potential as a promising detoxification agent against AFB1 exposure, with the intent to stimulate further research and practical utilization in this domain.

The Ferroptosis landscape of biotic interactions in plants

Ferroptosis is a cell death pathway that relies on iron- and reactive oxygen species-dependent lethal accumulation of lipid peroxides in the cytosol and/or plasma membrane. Interestingly, Ferroptosis is widely involved in modulating such regulated fatality in the host plant as well as the pathogen albeit with different outcome, dynamics, and interesting metabolic adaptations. Although the basic mechanism of Ferroptosis has been established recently in plants and associated microbes, the conservation, acclimatization, and application of such regulated cell death modality are now beginning to be explored further. Efforts towards this will certainly help better understand the origin, molecular mechanisms, and function of Ferroptosis-associated developmental regulation of biotic interactions in plants.

Ferroptosis-protective membrane domains in quiescence

Quiescence is a common cellular state, required for stem cell maintenance and microorganismal survival under stress conditions or starvation. However, the mechanisms promoting quiescence maintenance remain poorly known. Plasma membrane components segregate into distinct microdomains, yet the role of this compartmentalization in quiescence remains unexplored. Here, we show that flavodoxin-like proteins (FLPs), ubiquinone reductases of the yeast eisosome membrane compartment, protect quiescent cells from lipid peroxidation and ferroptosis. Eisosomes and FLPs expand specifically in respiratory-active quiescent cells, and mutants lacking either show accelerated aging and defective quiescence maintenance and accumulate peroxidized phospholipids with monounsaturated or polyunsaturated fatty acids (PUFAs). FLPs are essential for the extramitochondrial regeneration of the lipophilic antioxidant ubiquinol. FLPs, alongside the Gpx1/2/3 glutathione peroxidases, prevent iron-driven, PUFA-dependent ferroptotic cell death. Our work describes ferroptosis-protective mechanisms in yeast and introduces plasma membrane compartmentalization as an important factor in the long-term survival of quiescent cells.

Study of molecular patterns associated with ferroptosis in Parkinson's disease and its immune signature

Parkinson's disease is the second most common neurodegenerative disease in the world. We downloaded data on Parkinson's disease and Ferroptosis-related genes from the GEO and FerrDb databases. We used WCGAN and Random Forest algorithm to screen out five Parkinson's disease ferroptosis-related hub genes. Two genes were identified for the first time as possibly playing a role in Braak staging progression. Unsupervised clustering analysis based on hub genes yielded ferroptosis isoforms, and immune infiltration analysis indicated that these isoforms are associated with immune cells and may represent different immune patterns. FRHGs scores were obtained to quantify the level of ferroptosis modifications in each individual. In addition, differences in interleukin expression were found between the two ferroptosis subtypes. The biological functions involved in the hub gene are analyzed. The ceRNA regulatory network of hub genes was mapped. The disease classification diagnosis model and risk prediction model were also constructed by applying hub genes based on logistic regression. Multiple external datasets validated the hub gene and classification diagnostic model with some accuracy. This study explored hub genes associated with ferroptosis in Parkinson's disease and their molecular patterns and immune signatures to provide new ideas for finding new targets for intervention and predictive biomarkers.

The ubiquitin-proteasome system links NADPH metabolism to ferroptosis

Ferroptosis is the type of cell death arising from uncontrolled and excessive lipid peroxidation. NADPH is essential for ferroptosis regulation because it supplies reducing equivalents for antioxidant defense systems and contributes to the generation of reactive oxygen species. Moreover, NADPH level serves as a biomarker for predicting the sensitivity of cells to ferroptosis. The ubiquitin-proteasome system governs the stability of many ferroptosis effectors. Recent research has revealed MARCHF6, the endoplasmic reticulum ubiquitin ligase, as an unprecedented NADPH sensor in the ubiquitin system and a critical regulator of ferroptosis involved in tumorigenesis and fetal development. This review summarizes the current understanding of NADPH metabolism and the ubiquitin-proteasome system in regulating ferroptosis and highlights the emerging importance of MARCHF6 as a vital connector between NADPH metabolism and ferroptosis.

Mechanisms of ferroptosis and targeted therapeutic approaches in lymphoma

Lymphoma is the sixth most common type of cancer worldwide. Under the current treatment standards, patients with lymphoma often fail to respond to treatment or relapse early and require further therapy. Hence, novel therapeutic strategies need to be explored and our understanding of the molecular underpinnings of lymphomas should be expanded. Ferroptosis, a non-apoptotic regulated cell death, is characterized by increased reactive oxygen species and lipid peroxidation due to metabolic dysfunction. Excessive or lack of ferroptosis has been implicated in tumor development. Current preclinical evidences suggest that ferroptosis participates in tumorigenesis, progression, and drug resistance of lymphoma, identifying a potential biomarker and an attractive molecular target. Our review summarizes the core mechanisms and regulatory networks of ferroptosis and discusses existing evidences of ferroptosis induction for the treatment of lymphoma, with intent to provide a framework for understanding the role of ferroptosis in lymphomagenesis and a new perspective of lymphoma treatment.

Cinnamaldehyde Inhibits Postharvest Gray Mold on Pepper Fruits via Inhibiting Fungal Growth and Triggering Fruit Defense

Gray mold infected with Botrytis cinerea frequently appears on fruits and vegetables throughout the supply chain after harvest, leading to economic losses. Biological control of postharvest disease with phytochemicals is a promising approach. CA (cinnamaldehyde) is a natural phytochemical with medicinal and antimicrobial activity. This study evaluated the effect of CA in controlling B. cinerea on fresh pepper fruit. CA inhibited B. cinerea growth in vitro significantly in a dose- (0.1-0.8 mM) and time-dependent (6-48 h) manner, with an EC50 (median effective concentration) of 0.5 mM. CA induced the collapse and breakdown of the mycelia. CA induced lipid peroxidation resulting from ROS (reactive oxygen species) accumulation in mycelia, further leading to cell leakage, evidenced by increased conductivity in mycelia. CA induced mycelial glycerol accumulation, resulting in osmotic stress possibly. CA inhibited sporulation and spore germination resulting from ROS accumulation and cell death observed in spores. Spraying CA at 0.5 mM induced a defense response in fresh pepper fruits, such as the accumulation of defense metabolites (flavonoid and total phenols) and an increase in the activity of defense enzymes (PAL, phenylalanine ammonia lyase; PPO, polyphenol oxidase; POD, peroxidase). As CA is a type of environmentally friendly compound, this study provides significant data on the activity of CA in the biocontrol of postharvest gray mold in peppers.

Estragole Inhibits Growth and Aflatoxin Biosynthesis of Aspergillus flavus by Affecting Reactive Oxygen Species Homeostasis

A variety of essential oils and edible compounds have been widely recognized for their antifungal activity in recent years. In this study, we explored the antifungal activity of estragole from Pimenta racemosa against Aspergillus flavus and investigated the underlying mechanism of action. The results showed that estragole had significant antifungal activity against A. flavus, with a minimum inhibitory concentration of 0.5 μL/mL against spore germination. Additionally, estragole inhibited the biosynthesis of aflatoxin in a dose-dependent manner, and aflatoxin biosynthesis was significantly inhibited at 0.125 μL/mL. Pathogenicity assays showed that estragole had potential antifungal activity against A. flavus in peanut and corn grains by inhibiting conidia and aflatoxin production. Transcriptomic analysis showed that the differentially expressed genes (DEGs) were mainly related to oxidative stress, energy metabolism, and secondary metabolite synthesis following estragole treatment. Importantly, we experimentally verified reactive oxidative species accumulation following downregulation of antioxidant enzymes, including catalase, superoxide dismutase, and peroxidase. These results suggest that estragole inhibits the growth and aflatoxin biosynthesis of A. flavus by modulating intracellular redox homeostasis. These findings expand our knowledge on the antifungal activity and molecular mechanisms of estragole, and provide a basis for estragole as a potential agent against A. flavus contamination. IMPORTANCE Aspergillus flavus contaminates crops and produces aflatoxins, carcinogenic secondary metabolites which pose a serious threat to agricultural production and animal and human health. Currently, control of A. flavus growth and mycotoxin contamination mainly relies on antimicrobial chemicals, agents with side effects such as toxic residues and the emergence of resistance. With their safety, environmental friendliness, and high efficiency, essential oils and edible compounds have become promising antifungal agents to control growth and mycotoxin biosynthesis in hazardous filamentous fungi. In this study, we explored the antifungal activity of estragole from Pimenta racemosa against A. flavus and investigated its underlying mechanism. The results demonstrated that estragole inhibits the growth and aflatoxin biosynthesis of A. flavus by modulating intracellular redox homeostasis.

Inhibitory effect of cinnamaldehyde on Fusarium solani and its application in postharvest preservation of sweet potato

Root rot caused by Fusarium solani is one of major postharvest diseases limiting sweet potato production. Antifungal effect and possible mode of action of cinnamaldehyde (CA) against F. solani were investigated. CA concentration of 0.075 g/L inhibited conidial viability of F. solani. CA vapor of 0.3 g/L in air completely controlled the F. solani development in sweet potatoes during storage for 10 days at 28 °C, and protected soluble sugar and starch in the flesh from depletion by the fungus. Further results demonstrated that CA induced reduction in mitochondrial membrane potential (Δψ_m), ROS accumulation, and cell apoptosis characterized by DNA fragmentation in F. solani. Moreover, CA facilitated decomposition of mitochondria-specific cardiolipin (CL) into its catabolites by the catalytic action of phospholipases. Altogether, the results revealed a specific antifungal mechanism of CA against F. solani, and suggest that CA holds promise as a preservative for postharvest preservation of sweet potato.

AnAzf1 acts as a positive regulator of ochratoxin A biosynthesis in Aspergillus niger

Aspergillus niger produces genotoxic and carcinogenic ochratoxin A (OTA) that severely threatens human and animal health. Transcription factor Azf1 is essential in regulating fungal cell development and primary metabolism. However, its effect and mechanism on secondary metabolism are unclear. Here, we characterized and deleted a Azf1 homolog gene, An15g00120 (AnAzf1), in A. niger, which completely blocked OTA production, and repressed the OTA cluster genes, p450, nrps, hal, and bzip at the transcriptional level. The results indicated that AnAzf1 was a positive regulator of OTA biosynthesis. Transcriptome sequencing results showed that the AnAzf1 deletion significantly upregulated antioxidant genes and downregulated oxidative phosphorylation genes. Enzymes involved in reactive oxygen species (ROS) scavenging, including catalase (CAT) and peroxidase (POD) were increased, and the corresponding ROS levels were decreased. Upregulation of genes (cat, catA, hog1, and gfd) in the MAPK pathway and downregulation of genes in iron homeostasis were associated with decreased ROS levels, linking the altered MAPK pathway and iron homeostasis to lower ROS levels caused by AnAzf1 deletion. Additionally, enzymes including complex I (NADH-ubiquinone oxidoreductase), and complex V (ATP synthase), as well as ATP levels, were significantly decreased, indicating impaired oxidative phosphorylation caused by the AnAzf1-deletion. During lower ROS levels and impaired oxidative phosphorylation, OTA was not produced in ∆AnAzf1. Together, these results strongly suggested that AnAzf1 deletion blocked OTA production in A. niger by a synergistic interference of ROS accumulation and oxidative phosphorylation. KEY POINTS: • AnAzf1 positively regulated OTA biosynthesis in A. niger. • Deletion of AnAzf1 decreased ROS levels and impaired oxidative phosphorylation. • An altered MAPK pathway and iron homeostasis were associated with lower ROS levels.

An "intelligent -responsive" bactericidal system based on OSA-starch Pickering emulsion

Pickering emulsion based on OSA-starch was developed in this study as an intelligent delivery system for the application of thymol against foodborne pathogens. Morphology and microstructure characterization showed that the Pickering emulsion was an O/W type emulsion and stayed stable at starch concentration of 200 mg/mL and oil fraction at 30 % with particle size of 10 μm and absolute Zeta potential of -12.5 mV. Low field nuclear magnetic resonance and rheology experiments indicated that a denser network structure was formed in this stable Pickering emulsion. Besides, the Pickering emulsion could endure long-time storage, low pH (3,5) and additional NaCl (50, 100, 200, 400 mM) and it showed enhanced bactericidal effects against Escherichia coli, Staphylococcus aureus (thymol =1.48 μmol/L) and Aspergillus flavus (thymol = 0.624 μmol/L) by inducing ROS eruption, membrane lipid peroxidation and cell shrink. Moreover, the bactericidal assay demonstrated that thymol could be intelligently released and a considerable 75 % timely bactericidal effect was detected after 9 days' intermittently exposing to E. coli, S. aureus and A. flavus in vitro, by comparison thymol alone showed only 20 % bactericidal effect due to its volatility. The results are of great importance to offer an intelligent delivery system of bio-actives defending foodborne pathogens.

Insights on Ferroptosis and Colorectal Cancer: Progress and Updates

Patients with advanced-stage or treatment-resistant colorectal cancer (CRC) benefit less from traditional therapies; hence, new therapeutic strategies may help improve the treatment response and prognosis of these patients. Ferroptosis is an iron-dependent type of regulated cell death characterized by the accumulation of lipid reactive oxygen species (ROS), distinct from other types of regulated cell death. CRC cells, especially those with drug-resistant properties, are characterized by high iron levels and ROS. This indicates that the induction of ferroptosis in these cells may become a new therapeutic approach for CRC, particularly for eradicating CRC resistant to traditional therapies. Recent studies have demonstrated the mechanisms and pathways that trigger or inhibit ferroptosis in CRC, and many regulatory molecules and pathways have been identified. Here, we review the current research progress on the mechanism of ferroptosis, new molecules that mediate ferroptosis, including coding and non-coding RNA; novel inducers and inhibitors of ferroptosis, which are mainly small-molecule compounds; and newly designed nanoparticles that increase the sensitivity of cells to ferroptosis. Finally, the gene signatures and clusters that have predictive value on CRC are summarized.

Fe2+ protects postharvest pitaya (Hylocereus undulatus britt) from Aspergillus. flavus infection by directly binding its genomic DNA

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Light was shield on Fe²⁺ application as antifungal agent on pitaya postharvest.

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Fe²⁺ prevents A. flavus infection by directly binding to A. flavus DNA.

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This research will promote the research on the mechanism of fungal death.

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A new strategy was provided to combat fungal infection in fruit postharvest industry.

Aspergillus flavus (A. flavus) is a postharvest fungus, causing pitaya fruit decay and limiting pitaya value and shelf life. However, safer and more efficient methods for preventing A. flavus contamination for pitaya fruit remain to be investigated. In this study, we successfully proved exogenous Fe²⁺ could inhibit A. flavus colonization in pitaya fruit and extend pitaya’s shelf life after harvest. Moreover, gel electrophoresis, CD analysis and Raman spectrum tests revealed Fe²⁺ could more effectively and thoroughly promote conidial death by directly binding to A. flavus DNA. Increased expression of DNA damage repair-related genes after Fe²⁺ treatment was observed by transcription analysis, which might eventually lead to SOS response in A. flavus. These results indicated Fe²⁺ could prevent A. flavus infestation on pitaya in a novel, quickly responsive mechanism. Our results shed light on the potential application of Fe²⁺ in the food industry and provided a more universal antifungal agent against food pathogens.

Ferroptosis: A mixed blessing for infectious diseases

To date, it has been confirmed that the occurrence and development of infectious diseases are tightly associated with regulatory cell death processes, such as apoptosis, autophagy, and necroptosis. Ferroptosis, as a newly discovered form of regulatory cell death characterized by iron-dependent lipid peroxidation, is not only closely associated with tumor progression, but is also found to be tightly related to the regulation of infectious diseases, such as Tuberculosis, Cryptococcal meningitis, Malaria and COVID-2019. The emerging critical roles of ferroptosis that has been found in infectious disease highlight ferroptosis as a potential therapeutic target in this field, which is therefore widely expected to be developed into new therapy strategy against infectious diseases. Here, we summarized the underlying mechanisms of ferroptosis and highlighted the intersections between host immunity and ferroptosis. Moreover, we illuminated the roles of ferroptosis in the occurrence and progression of different infectious diseases, which might provide some unique inspiration and thought-provoking perspectives for the future research of these infectious diseases, especially for the development of ferroptosis-based therapy strategy against infectious diseases.

Insights into the Underlying Mechanism of Ochratoxin A Production in Aspergillus niger CBS 513.88 Using Different Carbon Sources

Aspergillus niger produces carcinogenic ochratoxin A (OTA), a serious food safety and human health concern. Here, the ability of A. niger CBS 513.88 to produce OTA using different carbon sources was investigated and the underlying regulatory mechanism was elucidated. The results indicated that 6% sucrose, glucose, and arabinose could trigger OTA biosynthesis and that 1586 differentially expressed genes (DEGs) overlapped compared to a non-inducing nutritional source, peptone. The genes that participated in OTA and its precursor phenylalanine biosynthesis, including pks, p450, nrps, hal, and bzip, were up-regulated, while the genes involved in oxidant detoxification, such as cat and pod, were down-regulated. Correspondingly, the activities of catalase and peroxidase were also decreased. Notably, the novel Gal4-like transcription factor An12g00840 (AnGal4), which is vital in regulating OTA biosynthesis, was identified. Deletion of AnGal4 elevated the OTA yields by 47.65%, 54.60%, and 309.23% using sucrose, glucose, and arabinose as carbon sources, respectively. Additionally, deletion of AnGal4 increased the superoxide anion and H₂O₂ contents, as well as the sensitivity to H₂O₂, using the three carbon sources. These results suggest that these three carbon sources repressed AnGal4, leading to the up-regulation of the OTA biosynthetic genes and alteration of cellular redox homeostasis, ultimately triggering OTA biosynthesis in A. niger.