Iron-overload-induced ferroptosis in mouse cerebral toxoplasmosis promotes brain injury and could be inhibited by Deferiprone

Ferroptosis-mediated immune responses in osteoporosis

Osteoporosis is a common systemic metabolic disease, characterized by decreased bone mass and susceptibility to fragility fractures, often associated with aging, menopause, genetics, and immunity. Ferroptosis plays an underestimated yet crucial role in the further impact of immune function changes on osteoporosis. Cell ferroptosis can induce alterations in immune function, subsequently influencing bone metabolism. In this context, this review summarizes several mechanisms of ferroptosis and introduces the latest insights on how ferroptosis regulates immune responses, exploring the interactions between ferroptosis and other mechanisms such as oxidative stress, inflammation, etc. This review elucidates potential treatment strategies for osteoporosis, emphasizing the promising potential of ferroptosis as an emerging target in the treatment of osteoporosis. In conclusion, preparations related to ferroptosis exhibit substantial clinical promise for enhancing bone mass restoration. The translational potential of this article: This review elucidates a nuanced conversation between the immune system and osteoporosis, with ferroptosis serving as the connecting link. These findings underscore the potential of ferroptosis inhibition as a therapeutic strategy for osteoporosis.

Identification of Isoliensinine as a Ferroptosis Suppressor with Iron-Chelating Activity

Ferroptosis is a type of regulated cell death driven by the iron-dependent accumulation of lipid peroxides. The high involvement of ferroptosis in diverse human diseases highlights the need for the identification of new chemotypes with anti-ferroptotic activity. Here, we performed a natural product library screening in HT1080 fibrosarcoma cells and identified licochalcone A (LA), isoeugenyl acetate (ISA), and isoliensinine (ISL) as suppressors of either RSL3- or IKE-induced ferroptosis. Mechanistically, ferroptosis resistance conferred by these compounds is mainly through GPX4/NRF2-independent mechanisms. Among them, only ISL could effectively rescue ferroptosis induced by FINO2, which is a stable oxidant of ferrous iron, suggesting that ISL may have the properties of an iron chelator. Consistent with the hypothesis, both computational tools and X-ray photoelectron spectroscopy supported the binding between ISL and iron ions. And ISL greatly inhibited excessive iron-dependent ferroptotic cell death through limiting intracellular iron accumulation. Furthermore, its iron chelator activity also protected mice from organ injury in an acute iron overload model. In conclusion, this study provided valuable insights for developing effective anti-ferroptosis agents from natural products, which represent a potential therapeutic strategy for treating ferroptosis-associated organ damage.

Echinococcus granulosus-Induced Liver Damage Through Ferroptosis in Rat Model

(1) Background: Cystic echinococcosis (CE) is an Echinococcus granulosus-induced worldwide parasitic zoonosis and is a recognized public health and socio-economic concern. The liver is the major target organ for CE's infective form protoscolex (PSCs), which causes serious liver damage and endangers the host's life. Reports show that PSC infection causes liver cell Fe2+ metabolism disorder and abnormal deposition of Fe2+ in liver cells and results in liver cell death. However, whether PSC-induced liver cell death is associated with ferroptosis remains to be clarified. (2) Methods: Using both an in vivo rat model and an in vitro co-culture of PSCs and the cell system, we studied the histopathological progress of PSCs infection and the cytopathogenesis of PSC-induced cell death in the liver. Hepatic-injury-related ferroptosis signaling pathways were identified by proteomics analysis at various stages of PSCs infection, and physiological and the biochemical indexes and expression of pathway proteins related to hepatic ferroptosis were studied. Ferrostatin-1, a ferroptosis inhibitor, was employed for in vivo interference with early protoscolices infection in rats, and the effects of the inhibition of hepatocyte ferroptosis on hepatocyte injury and the generation of fibrotic cysts were investigated. Additionally, PSCs were exposed to in vitro co-culture with BRL, a rat hepatocyte line, to clarify the direct influences of PSCs on BRL ferroptosis. (3) Results: The results of our in vivo studies revealed that PSCs infection induced Fe2+ enrichment in liver cells surrounding the PSCs cysts, cellular oxidation, and liver tissue damage along with the prolongation of PSCs parasitism. The results of our in vitro studies verified the ability of PSCs to directly induce ferroptosis, the formation of fibrotic cysts, and alteration of the iron metabolism of liver cells. The analysis of KEGG signaling pathways revealed that ferroptosis- and ROS-related pathways were significantly induced with PSCs infection. Using Ferrostatin-1 effectively blocked ferroptosis, reversed Fe2+ content, reduced liver cell oxidation, and reduced PSC-induced fibrosis cysts. (4) Conclusions: Our study reveals the histopathological progress of PSC infection and the cytopathogenesis of PSC-induced ferroptosis. Ferrostatin-1 effectively blocked PSCs infection and PSC-induced cell death in vivo and in vitro. Accordingly, the inhibition of PSC-induced hepatocyte ferroptosis may be an effective method in the control of Echinococcus granulosus infection and should be seriously considered in clinical studies.

The emerging role and therapeutical implications of ferroptosis in wound healing

Wound healing is a complex biological process involving multiple steps, including hemostasis, inflammation, proliferation, and remodeling. A novel form of regulated cell death, ferroptosis, has garnered attention because of its involvement in these processes. Ferroptosis is characterized by the accumulation of lipid peroxides and is tightly regulated by lipid metabolism, iron metabolism, and the lipid-peroxide repair network, all of which exert a significant influence on wound healing. This review highlights the current findings and emerging concepts regarding the multifaceted roles of ferroptosis throughout the stages of normal and chronic wound healing. Additionally, the potential of targeted interventions aimed at modulating ferroptosis to improve wound-healing outcomes is discussed.

Mycobacterium tuberculosis exploits SIRT2 to trap iron for its intracellular survival

Iron is a critical nutrient for all organisms ranging from bacteria to humans. Ensuring control of this strategic vital resource significantly influences the dynamics of the struggle between host and invading pathogen. Mycobacterium tuberculosis (Mtb), the causative agent of the pulmonary disease tuberculosis (TB), has been plaguing humans for millennia and has evolved to successfully persist and multiply within host cells evading the mammalian immune defences. Invading Mtb appropriates host iron for its survival while the host innate immune response attempts to prevent its stores of this strategic mineral from being appropriated. SIRT2 is a member of the Sirtuin family. These are evolutionary conserved NAD+-dependent deacetylases involved in various cellular processes including regulation of cellular iron homeostasis. Upon Mtb infection of macrophages, SIRT2 expression is enhanced and it translocates from cytosol to nucleus. This is accompanied with a breakdown of the host's iron restriction strategy that compromises host defence mechanisms. However, the underlying mechanism as to how invading Mtb exploits SIRT2 for commandeering host iron remains unknown. In the current study, we report that the decreased bacillary load in cells wherein SIRT2 had been chemically inhibited or knocked down is due to diminished availability of iron. Inhibition or knockdown of SIRT2 in infected cells displays differential modulation of iron import and export proteins suggesting an ongoing struggle by host to limit the bioavailability of iron to pathogen. Flow cytometry analysis of infected macrophages revealed that these cells utilize a non-canonical pathway for evacuation of intracellular iron. This involves the recruitment of a specific pleioform of the moonlighting protein glyceraldehyde-3 phosphate dehydrogenase (GAPDH) to cell surface for capture of iron transporter protein apo-transferrin. Collectively, our findings reveal the process of SIRT2-mediated iron regulation in Mtb pathogenesis and could provide leads for design of novel host-targeted therapeutics.

MDH2 Promotes Hepatocellular Carcinoma Growth Through Ferroptosis Evasion via Stabilizing GPX4

The crosstalk between tumor progression and ferroptosis is largely unknown. Here, we identify malate dehydrogenase 2 (MDH2) as a key regulator of ferroptosis. MDH2 deficiency inhibits the growth of hepatocellular carcinoma (HCC) cells and enhances their sensitivity to ferroptosis induced by RAS-selective lethal 3 (RSL3), a compound known to cause ferroptosis. MDH2 knock-down enhances RSL3-induced intracellular reactive oxygen species, free iron ions and lipid per-oxides levels, leading to HCC ferroptotic cell death which is rescued by ferrostatin-1 and iron chelator deferiprone. Importantly, the inhibition of HCC cell growth caused by MDH2 deficiency is partially rescued by ferroptosis blockade. Mechanistically, MDH2 resists RSL3-induced ferroptosis sensitivity dependent on glutathione peroxidase 4 (GPX4), an enzyme responsible for scavenging lipid peroxides, which is stabilized by MDH2 in HCC. The protein expressions of MDH2 and GPX4 are positively correlated with each other in HCC cell lines. Furthermore, through our UALCAN website analysis, we found that MDH2 and GPX4 are highly expressed in HCC samples. These findings reveal a critical mechanism by which HCC evades ferroptosis via MDH2-mediated stabilization of GPX4 to promote tumor progression and underscore the potential of MDH2 inhibition in combi-nation with ferroptosis inducers for the treatment of HCC.

Recent advances in potential therapeutic targets of ferroptosis‑associated pathways for the treatment of stroke (Review)

Stroke is a severe neurological disease that is associated with high rates of morbidity and mortality, and the underlying pathological processes are complex. Ferroptosis fulfills a significant role in the progression and treatment of stroke. It is well established that ferroptosis is a type of programmed cell death that is distinct from other forms or types of cell death. The process of ferroptosis involves multiple signaling pathways and regulatory mechanisms that interact with mechanisms inherent to stroke development. Inducers and inhibitors of ferroptosis have been shown to exert a role in the onset of this cell death process. Furthermore, it has been shown that interfering with ferroptosis affects the occurrence of stroke, indicating that targeting ferroptosis may offer a promising therapeutic approach for treating patients of stroke. Hence, the present review aimed to summarize the latest progress that has been made in terms of using therapeutic interventions for ferroptosis as treatment targets in cases of stroke. It provides an overview of the relevant pathways and molecular mechanisms that have been investigated in recent years, highlighting the roles of inducers and inhibitors of ferroptosis in stroke. Additionally, the intervention potential of various types of Traditional Chinese Medicine is also summarized. In conclusion, the present review provides a comprehensive overview of the potential therapeutic targets afforded by ferroptosis‑associated pathways in stroke, offering new insights into how ferroptosis may be exploited in the treatment of stroke.

Phytometabolites from coral jasmine flower extracts: Toxic effects on Spodoptera litura and enzyme inhibition in nontarget earthworm Eisenia fetida as an alternative approach

Green pesticides, derived from natural sources, have gained wider attention as an alternative to synthetic pesticides for managing polyphagous pests, such as Spodoptera litura. In this study, the methanolic flower extract of Nyctanthes arbor-tristis (Mx-Na-t) was subjected to chemical screening, and 3-hydroxy-1,2-dimethyl-4(1H)-pyridone (3H-dp) and tyrosol (Ty-ol) were identified as the major derivatives. The toxic effects of Mx-Na-t (500 ppm) were highest in third-instar S. litura larvae (96.4%), while those of 3H-dp and Ty-ol (5 ppm) were highest in second-instar larvae (76.5% and 81.4%, respectively). The growth and development of S. litura larvae and pupae were significantly reduced by all three treatments. Fecundity rates were also reduced by all treatments [from 1020 eggs (control) to 540 eggs by Mx-Na-t treatment, 741 eggs by 3H-dp treatment, and 721 eggs by Ty-ol treatment]. The extract and its active constituents decreased adult emergence and slowed total larval development in a dose-dependent manner. A decrease was noted in the major gut enzymes of young S. litura larvae exposed to Mx-Na-t, 3H-dp, and Ty-ol. Moreover, midgut tissues of fourth-instar larvae were severely damaged by Mx-Na-t (250 ppm), 3H-dp (2.5 ppm), and Ty-ol (2.5 ppm); the treatments induced structural damage to the epithelial cells and gut lumen. The earthworm Eisenia fetida was used to assess nontarget toxicity. Compared with cypermethrin, the phytochemicals exhibited minimal effects on the earthworm's detoxifying enzymes superoxide dismutase and catalase after 14 days of treatment. Moreover, in silico predictions using BeeTox and ProTox-II indicated little or no toxicity of 3H-dp and Ty-ol toward honey bees and other nontarget species.

The Importance and Essentiality of Natural and Synthetic Chelators in Medicine: Increased Prospects for the Effective Treatment of Iron Overload and Iron Deficiency

The supply and control of iron is essential for all cells and vital for many physiological processes. All functions and activities of iron are expressed in conjunction with iron-binding molecules. For example, natural chelators such as transferrin and chelator-iron complexes such as haem play major roles in iron metabolism and human physiology. Similarly, the mainstay treatments of the most common diseases of iron metabolism, namely iron deficiency anaemia and iron overload, involve many iron-chelator complexes and the iron-chelating drugs deferiprone (L1), deferoxamine (DF) and deferasirox. Endogenous chelators such as citric acid and glutathione and exogenous chelators such as ascorbic acid also play important roles in iron metabolism and iron homeostasis. Recent advances in the treatment of iron deficiency anaemia with effective iron complexes such as the ferric iron tri-maltol complex (feraccru or accrufer) and the effective treatment of transfusional iron overload using L1 and L1/DF combinations have decreased associated mortality and morbidity and also improved the quality of life of millions of patients. Many other chelating drugs such as ciclopirox, dexrazoxane and EDTA are used daily by millions of patients in other diseases. Similarly, many other drugs or their metabolites with iron-chelation capacity such as hydroxyurea, tetracyclines, anthracyclines and aspirin, as well as dietary molecules such as gallic acid, caffeic acid, quercetin, ellagic acid, maltol and many other phytochelators, are known to interact with iron and affect iron metabolism and related diseases. Different interactions are also observed in the presence of essential, xenobiotic, diagnostic and theranostic metal ions competing with iron. Clinical trials using L1 in Parkinson's, Alzheimer's and other neurodegenerative diseases, as well as HIV and other infections, cancer, diabetic nephropathy and anaemia of inflammation, highlight the importance of chelation therapy in many other clinical conditions. The proposed use of iron chelators for modulating ferroptosis signifies a new era in the design of new therapeutic chelation strategies in many other diseases. The introduction of artificial intelligence guidance for optimal chelation therapeutic outcomes in personalised medicine is expected to increase further the impact of chelation in medicine, as well as the survival and quality of life of millions of patients with iron metabolic disorders and also other diseases.

Ferroptosis in organ fibrosis: From mechanisms to therapeutic medicines

Fibrosis occurs in many organs, and its sustained progress can lead to organ destruction and malfunction. Although numerous studies on organ fibrosis have been carried out, its underlying mechanism is largely unknown, and no ideal treatment is currently available. Ferroptosis is an iron-dependent process of programmed cell death that is characterized by lipid peroxidation. In the past decade, a growing body of evidence demonstrated the association between ferroptosis and fibrotic diseases, while targeting ferroptosis may serve as a potential therapeutic strategy. This review highlights recent advances in the crosstalk between ferroptosis and organ fibrosis, and discusses ferroptosis-targeted therapeutic approaches against fibrosis that are currently being explored.