Ferroptosis-relevant mechanisms and biomarkers for therapeutic interventions in traumatic brain injury

Orexin-A alleviates ferroptosis by activating the Nrf2/HO-1 signaling pathway in traumatic brain injury

BACKGROUND

Traumatic Brain Injury (TBI) has high disability and mortality rate. Oxidative stress and ferroptosis are important pathophysiological characteristics after TBI. Orexin-A (OXA) can alleviate neuronal damage in diverse neurological disorders. Nevertheless, the role and mechanism of OXA in TBI stay unknown.

OBJECTIVES

The research investigated protection influence of OXA on TBI and its potential mechanisms.

METHODS

Male Sprague-Dawley rats were randomly grouped into: sham, TBI, TBI + normal saline (NS) and TBI+OXA groups. TBI model was constructed in rat via modified Feeney's approach, and OXA treatment was administered following construction of TBI model.

RESULTS

Relative to TBI+NS group, TBI+OXA group displayed greatly recovered tissue damage and neurological deficits. Additionally, OXA eased oxidative stress as well as ferroptosis in cerebral cortex of rats following TBI. Furthermore, OXA increased Nrf2 expression and regulating factors HO-1 and NQO1 in cerebral cortex of TBI rats.

CONCLUSIONS

Our research found OXA may restrain ferroptosis via Nrf2/HO-1 signaling pathway activation, thereby reducing brain injury after TBI.

Synergistic cardioprotective effects of melatonin and deferoxamine through the improvement of ferritinophagy in doxorubicin-induced acute cardiotoxicity

Ferritinophagy is one of the most recent molecular mechanisms affecting cardiac function. In addition, it is one of the pathways by which doxorubicin, one of the anticancer drugs commonly used, negatively impacts the cardiac muscle, leading to cardiac function impairment. This side effect limits the use of doxorubicin. Iron chelators play an important role in hindering ferritinophagy. Antioxidants can also impact ferritinophagy by improving oxidative stress. In this study, it was assumed that the antioxidant function of melatonin could promote the action of deferoxamine, an iron chelator, at the level of ferritinophagy. A total of 42 male Wistar rats (150-200 g) were divided into seven groups (n = 6) which consisted of group I: control normal, group II: doxorubicin (Dox), group III: melatonin (Mel), group IV: deferoxamine (Des), group V: Mel + Dox, group VI: Des + Dox, and group VII: Mel + Des + Dox. Groups III, V and VII were orally pretreated with melatonin 20 mg/kg/day for 7 days. Groups IV, VI and VII were treated with deferoxamine at a 250 mg/kg/dose once on D4 before Dox was given. Doxorubicin was given at a 20 mg/kg ip single dose. On the 8th day, the rats were lightly anaesthetized for electrocardiography analysis and echocardiography. Serum samples were collected and then sacrificed for tissue sampling. The following biochemical assessments were carried out: PCR of NCOA4, IREB2, FTH1, SLC7A11, and GPX4; and ELISA for serum cTnI, serum transferrin, tissue GSH, and malondialdehyde. In addition, histopathological assessment of heart injury; immunostaining of caspase-3, Bax, and Bcl2; and physiological function assessment by ECG and ECHO were carried out. Doxorubicin-induced acute significant cardiac injury with increased ferritinophagy and apoptosis responded to single and combined prophylactic treatment, in which the combined treatment showed mostly the best results. In conclusion, using melatonin as an antioxidant with an iron chelator, deferoxamine, could hinder the hazardous cardiotoxic effect of doxorubicin. However, further studies are needed to detect the impact of higher doses of melatonin and deferoxamine with a prolonged treatment period.

Ferroptosis-related differentially expressed genes serve as new biomarkers in ischemic stroke and identification of therapeutic drugs

BACKGROUND

Iron is an essential nutrient element, and iron metabolism is related to many diseases. Ferroptosis is an iron-dependent form of regulated cell death associated with ischemic stroke (IS). Hence, this study intended to discover and validate the possible ferroptosis-related genes involved in IS.

MATERIALS AND METHODS

GSE16561, GSE37587, and GSE58294 were retrieved from the GEO database. Using R software, we identified ferroptosis-related differentially expressed genes (DEGs) in IS. Protein-protein interactions (PPIs) and enrichment analyses were conducted. The ROC curve was plotted to explore the diagnostic significance of those identified genes. The consistent clustering method was used to classify the IS samples. The level of immune cell infiltration of different subtypes was evaluated by ssGSEA and CIBERSORT algorithm. Validation was conducted in the test sets GSE37587 and GSE58294.

RESULTS

Twenty-one ferroptosis-related DEGs were detected in IS vs. the normal controls. Enrichment analysis shows that the 21 DEGs are involved in monocarboxylic acid metabolism, iron ion response, and ferroptosis. Moreover, their expression levels were pertinent to the age and gender of IS patients. The ROC analysis demonstrated remarkable diagnostic values of LAMP2, TSC22D3, SLC38A1, and RPL8 for IS. Transcription factors and targeting miRNAs of the 21 DEGs were determined. Vandetanib, FERRIC CITRATE, etc., were confirmed as potential therapeutic drugs for IS. Using 11 hub genes, IS patients were categorized into C1 and C2 subtypes. The two subtypes significantly differed between immune cell infiltration, checkpoints, and HLA genes. The 272 DEGs were identified from two subtypes and their biological functions were explored. Verification was performed in the GSE37587 and GSE58294 datasets.

CONCLUSION

Our findings indicate that ferroptosis plays a critical role in the diversity and complexity of the IS immune microenvironment.

Interaction between macrophages and ferroptosis

Abstract

Ferroptosis, a newly discovered iron-dependent cell death pathway, is characterized by lipid peroxidation and GSH depletion mediated by iron metabolism and is morphologically, biologically and genetically different from other programmed cell deaths. Besides, ferroptosis is usually found accompanied by inflammatory reactions. So far, it has been found participating in the development of many kinds of diseases. Macrophages are a group of immune cells that widely exist in our body for host defense and play an important role in tissue homeostasis by mediating inflammation and regulating iron, lipid and amino acid metabolisms through their unique functions like phagocytosis and efferocytosis, cytokines secretion and ROS production under different polarization. According to these common points in ferroptosis characteristics and macrophages functions, it’s obvious that there must be relationship between macrophages and ferroptosis. Therefore, our review aims at revealing the interaction between macrophages and ferroptosis concerning three metabolisms and integrating the application of certain relationship in curing diseases, mostly cancer. Finally, we also provide inspirations for further studies in therapy for some diseases by targeting certain resident macrophages in distinct tissues to regulate ferroptosis.

Facts

Ferroptosis is considered as a newly discovered form characterized by its nonapoptotic and iron-dependent lipid hydroperoxide, concerning iron, lipid and amino acid metabolisms.

Ferroptosis has been widely found playing a crucial part in various diseases, including hepatic diseases, neurological diseases, cancer, etc.

Macrophages are phagocytic immune cells, widely existing and owning various functions such as phagocytosis and efferocytosis, cytokines secretion and ROS production.

Macrophages are proved to participate in mediating metabolisms and initiating immune reactions to maintain balance in our body.

Recent studies try to treat cancer by altering macrophages’ polarization which damages tumor microenvironment and induces ferroptosis of cancer cells.

Open questions

How do macrophages regulate ferroptosis of other tissue cells specifically?

Can we use the interaction between macrophages and ferroptosis in treating diseases other than cancer?

What can we do to treat diseases related to ferroptosis by targeting macrophages?

Is the use of the relationship between macrophages and ferroptosis more effective than other therapies when treating diseases?

Bibliometric Analysis of Ferroptosis in Stroke From 2013 to 2021

Background: Stroke is a major cause of long-term disability and death, but the clinical therapeutic strategy for stroke is limited and more research must be conducted to explore the possible avenues for stroke treatment and recovery. Since ferroptosis is defined, its role in the body has become the focus of attention and discussion, including in stroke.

Methods: In this work, we aim to systematically discuss the “ferroptosis in stroke” research by bibliometric analysis. Documents were retrieved from the Web of Science Core Collection database on October 30, 2021. Statistical analysis and visualization analysis were conducted by the VOSviewer 1.6.15.

Results: Ninety-nine documents were identified for bibliometric analysis. Research on “ferroptosis in stroke” has been rapidly developing and has remained the focus of many scholars and organizations in the last few years, but the Chinese groups in this field still lacked collaboration with others. Documents and citation analysis suggested that Rajiv R. Ratan and Brent R. Stockwell are active researchers, and the research by Qingzhang Tuo, Ishraq Alim, and Qian Li are more important drivers in the development of the field. Keywords associated with lipid peroxidation, ferroptosis, iron, oxidative stress, and cell death had high frequency, but apoptosis, necroptosis, pyroptosis, and autophagy had scant research, and there may be more research ideas in the future by scholars.

Conclusion: Further exploration of the mechanisms of crosstalk between ferroptosis and other programmed cell death may improve clinical applications and therapeutic effects against stroke. Scholars will also continue to pay attention to and be interested in the hot topic “ferroptosis in stroke”, to produce more exciting results and provide new insights into the bottleneck of stroke treatment.

Bioinformatics Identification of Ferroptosis-Related Biomarkers and Therapeutic Compounds in Ischemic Stroke

Background: Stroke is one of the most common deadly diseases with an estimated 780,000 new cases globally, of which ischemic stroke accounts for over 80% of all cases. Ferroptosis is a new form of programmed cell death that plays a vital role in many diseases, including ischemic stroke and heart diseases. The role of the ferroptosis-related gene in the diagnosis, prognosis, or therapy of ischemic stroke was not fully clarified.

Methods: Ferroptosis-related differentially expressed genes (DEGs) in ischemic stroke were identified by bioinformatic analysis of the GSE16561 and GSE22255 datasets. Subsequently, receiver operator characteristic (ROC) monofactor analysis was performed to evaluate the diagnostic value of ferroptosis-related biomarkers in ischemic stroke.

Results: A total of 10 ferroptosis-related DEGs were identified in ischemic stroke vs. normal control. GO and KEGG analysis revealed that these 10 ferroptosis-related DEGs were mainly enriched in response to oxidative stress, HIF-1 signaling pathway, ferroptosis, lipid, and atherosclerosis. Moreover, the random forest model suggested three ferroptosis-related biomarkers, namely, PTGS2, MAP1LC3B, and TLR4, for ischemic stroke. Interestingly, the expression of PTGS2, MAP1LC3B, and TLR4 was upregulated in ischemic stroke. ROC monofactor analysis demonstrated a good performance of MAP1LC3B, PTGS2, and TLR4 in the diagnosis of ischemic stroke. The expression and diagnostic value of MAP1LC3B, PTGS2, and TLR4 in ischemic stroke were also verified using GSE22255. We also revealed the transcription factor regulation network and co-expressed protein network of ferroptosis-related biomarkers. Several potential therapeutic compounds corresponding to MAP1LC3B, PTGS2, and TLR4 were also identified for ischemic stroke, including Zinc12503187 (Conivaptan), Zinc3932831 (Avodart), Zinc64033452 (Lumacaftor), Zinc11679756 (Eltrombopag), Zinc100378061 (Naldemedine), and Zinc3978005 (Dihydroergotamine).

Conclusion: Our results suggested MAP1LC3B, PTGS2, and TLR4 as potential diagnostic biomarkers for ischemic stroke, providing more evidence about the vital role of ferroptosis in ischemic stroke.

Ferroptosis Is a Potential Novel Diagnostic and Therapeutic Target for Patients With Cardiomyopathy

Cardiomyocyte death is a fundamental progress in cardiomyopathy. However, the mechanism of triggering the death of myocardial cells remains unclear. Ferroptosis, which is the nonapoptotic, iron-dependent, and peroxidation-driven programmed cell death pathway, that is abundant and readily accessible, was not discovered until recently with a pharmacological approach. New researches have demonstrated the close relationship between ferroptosis and the development of many cardiovascular diseases, and several ferroptosis inhibitors, iron chelators, and small antioxidant molecules can relieve myocardial injury by blocking the ferroptosis pathways. Notably, ferroptosis is gradually being considered as an important cell death mechanism in the animal models with multiple cardiomyopathies. In this review, we will discuss the mechanism of ferroptosis and the important role of ferroptosis in cardiomyopathy with a special emphasis on the value of ferroptosis as a potential novel diagnostic and therapeutic target for patients suffering from cardiomyopathy in the future.

Calcium-Dependent Translocation of S100B Is Facilitated by Neurocalcin Delta

S100B is a calcium-binding protein that governs calcium-mediated responses in a variety of cells—especially neuronal and glial cells. It is also extensively investigated as a potential biomarker for several disease conditions, especially neurodegenerative ones. In order to establish S100B as a viable pharmaceutical target, it is critical to understand its mechanistic role in signaling pathways and its interacting partners. In this report, we provide evidence to support a calcium-regulated interaction between S100B and the neuronal calcium sensor protein, neurocalcin delta both in vitro and in living cells. Membrane overlay assays were used to test the interaction between purified proteins in vitro and bimolecular fluorescence complementation assays, for interactions in living cells. Added calcium is essential for interaction in vitro; however, in living cells, calcium elevation causes translocation of the NCALD-S100B complex to the membrane-rich, perinuclear trans-Golgi network in COS7 cells, suggesting that the response is independent of specialized structures/molecules found in neuronal/glial cells. Similar results are also observed with hippocalcin, a closely related paralog; however, the interaction appears less robust in vitro. The N-terminal region of NCALD and HPCA appear to be critical for interaction with S100B based on in vitro experiments. The possible physiological significance of this interaction is discussed.

Intravesical In Situ Immunostimulatory Gel for Triple Therapy of Bladder Cancer

Bladder cancer displays multiple biological features aided in drug resistance; therefore, single therapy fails to induce complete tumor regression. To address this issue, various kinds of cell death of cancer cells as well as restoring tumor immune microenvironment need to be taken into consideration. Here, we introduce a gel system termed AuNRs&IONs@Gel, which target-delivers a combination of photothermal, ferroptotic, and immune therapy through intravesical instillation. AuNRs&IONs@Gel consists of a gel delivery platform, embedded gold nanorods (AuNRs), and iron oxide nanoparticles (IONs). The targeted delivery gel platform provides dextran aldehyde-selective adhesion with cancer collagen. In this condition, photothermal therapy can be performed by gold nanorods (AuNRs) under imaging-guided near-infrared radiation. Local high concentrations of IONs can be absorbed by cancer cell to induce ferroptosis. Moreover, tumor-associated macrophages which often display an immune-suppressive M2-like phenotype will be repolarized by IONs into the antitumor M1-like phenotype, exerting a direct antitumor effect and professional antigen presentation of dead cancer cells. This process triggers a potent immune response of innate and adapt immunities to protect tumor rechallenge in long terms. Our triple-therapy strategy employs FDA-approved nanoparticles to inhibit bladder cancer which may possess great potential for clinical translation.