liproxstatin-1 and Reperfusion-Injury

Ferroptosis is an iron-dependent form of cell death characterized by intracellular lipid peroxide accumulation and redox imbalance. Ferroptosis shows specific biological and morphological features when compared to the other cell death patterns. The loss of lipid peroxide repair activity by glutathione peroxidase 4 (GPX4), the presence of redox-active iron and the oxidation of polyunsaturated fatty acid (PUFA)-containing phospholipids are considered as distinct fingerprints of ferroptosis. Several pathways, including amino acid and iron metabolism, ferritinophagy, cell adhesion, p53, Keap1/Nrf2 and phospholipid biosynthesis, can modify susceptibility to ferroptosis. Through the decades, various diseases, including acute kidney injury; cancer; ischemia-reperfusion injury; and cardiovascular, neurodegenerative and hepatic disorders, have been associated with ferroptosis. In this review, we provide a comprehensive analysis of the main biological and biochemical mechanisms of ferroptosis and an overview of chemicals used as inducers and inhibitors. Then, we report the contribution of ferroptosis to the spectrum of liver diseases, acute or chronic. Finally, we discuss the use of ferroptosis as a therapeutic approach against hepatocellular carcinoma, the most common form of primary liver cancer.

Topics: alpha-Tocopherol; Animals; Autophagy; Chemical and Drug Induced Liver Injury; Cyclohexylamines; Cysteine; Ferroptosis; Glutathione; Heme; Humans; Iron; Kelch-Like ECH-Associated Protein 1; Lipid Peroxidation; Lipoxygenase; Liver Diseases; Liver Neoplasms; Oxidative Stress; Phenylenediamines; Phospholipid Hydroperoxide Glutathione Peroxidase; Piperazines; Quinoxalines; Reactive Oxygen Species; Reperfusion Injury; Signal Transduction; Sorafenib; Spiro Compounds; Sulfasalazine; Tumor Suppressor Protein p53

Ferroptosis is a widely recognized process of regulated cell death linking redox state, metabolism, and human health. It is considered a defense mechanism against extensive lipid peroxidation, a complex process that may disrupt the membrane integrity, eventually leading to toxic cellular injury. Ferroptosis is controlled by iron, reactive oxygen species, and polyunsaturated fatty acids. Accumulating evidence has addressed that ferroptosis plays an unneglectable role in regulating the development and progression of multiple pathologies of the liver, including hepatocellular carcinoma, liver fibrosis, nonalcoholic steatosis, hepatic ischemia-reperfusion injury, and liver failure. This review may increase our understating of the cellular and molecular mechanisms of liver disease progression and establish the foundation of strategies for pharmacological intervention.

Topics: Animals; Antineoplastic Agents; Caffeic Acids; Carcinoma, Hepatocellular; Cycloheximide; Cyclohexylamines; Deferoxamine; Disease Models, Animal; Disease Progression; Fatty Acids, Unsaturated; Ferroptosis; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Iron; Lipid Peroxidation; Liver; Liver Cirrhosis; Liver Failure; Liver Neoplasms; Non-alcoholic Fatty Liver Disease; Phenylenediamines; Quinoxalines; Reactive Oxygen Species; Reperfusion Injury; Spiro Compounds

Ferroptosis is a recently described form of regulated necrotic cell death, which appears to contribute to a number of diseases, such as tissue ischemia/reperfusion injury, acute renal failure, and neurodegeneration. A hallmark of ferroptosis is iron-dependent lipid peroxidation, which can be inhibited by the key ferroptosis regulator glutathione peroxidase 4(Gpx4), radical trapping antioxidants and ferroptosis-specific inhibitors, such as ferrostatins and liproxstatins, as well as iron chelation. Although great strides have been made towards a better understanding of the proximate signals of distinctive lipid peroxides in ferroptosis, still little is known about the mechanistic implication of iron in the ferroptotic process. Hence, this review aims at summarizing recent advances in our understanding to what is known about enzymatic and nonenzymatic routes of lipid peroxidation, the involvement of iron in this process and the identification of novel players in ferroptotic cell death. Additionally, we review early works carried out long time before the term "ferroptosis" was actually introduced but which were instrumental in a better understanding of the role of ferroptosis in physiological and pathophysiological contexts. © 2017 IUBMB Life, 69(6):423-434, 2017.

Topics: Animals; Antioxidants; Cell Death; Cyclohexylamines; Glutathione Peroxidase; Humans; Iron; Iron Chelating Agents; Iron Metabolism Disorders; Lipid Peroxidation; Necrosis; Neuroaxonal Dystrophies; Phenylenediamines; Phospholipid Hydroperoxide Glutathione Peroxidase; Quinoxalines; Renal Insufficiency; Reperfusion Injury; Spiro Compounds

Primary graft dysfunction, which is directly related to cold ischemia-reperfusion (CI/R) injury, is a major obstacle in lung transplantation (LTx). Ferroptosis, a novel mode of cell death elicited by iron-dependent lipid peroxidation, has been implicated in ischemic events. This study aimed to investigate the role of ferroptosis in LTx-CI/R injury and the effectiveness of liproxstatin-1 (Lip-1), a ferroptosis inhibitor, in alleviating LTx-CI/R injury.. LTx-CI/R-induced signal pathway alterations, tissue injury, cell death, inflammatory responses, and ferroptotic features were examined in human lung biopsies, the human bronchial epithelial (BEAS-2B) cells, and the mouse LTx-CI/R model (24-h CI/4-h R). The therapeutic efficacy of Lip-1 was explored and validated both in vitro and in vivo.. In human lung tissues, LTx-CI/R activated ferroptosis-related signaling pathway, increased the tissue iron content and lipid peroxidation accumulation, and altered key protein (GPX4, COX2, Nrf2, and SLC7A11) expression and mitochondrial morphology. In BEAS-2B cells, the hallmarks of ferroptosis were significantly evidenced at the setting of both CI and CI/R compared with the control, and the effect of adding Lip-1 only during CI was much better than that of only during reperfusion by Cell Counting Kit-8. Furthermore, Lip-1 administration during CI markedly relieved LTx-CI/R injury in mice, as indicated by significant improvement in lung pathological changes, pulmonary function, inflammation, and ferroptosis.. This study revealed the existence of ferroptosis in the pathophysiology of LTx-CI/R injury. Using Lip-1 to inhibit ferroptosis during CI could ameliorate LTx-CI/R injury, suggesting that Lip-1 administration might be proposed as a new strategy for organ preservation.

Topics: Animals; Disease Models, Animal; Ferroptosis; Humans; Iron; Lung Transplantation; Mice; Reperfusion Injury

Ferroptosis is a recently identified form of regulated cell death defined by the iron-dependent accumulation of lipid reactive oxygen species. Ferroptosis has been studied in various diseases such as cancer, Parkinson's disease, and stroke. However, the exact function and mechanism of ferroptosis in ischemia/reperfusion (I/R) injury, especially in the intestine, remains unknown. Considering the unique conditions required for ferroptosis, we hypothesize that ischemia promotes ferroptosis immediately after intestinal reperfusion. In contrast to conventional strategies employed in I/R studies, we focused on the ischemic phase. Here we verified ferroptosis by assessing proferroptotic changes after ischemia along with protein and lipid peroxidation levels during reperfusion. The inhibition of ferroptosis by liproxstatin-1 ameliorated I/R-induced intestinal injury. Acyl-CoA synthetase long-chain family member 4 (ACSL4), which is a key enzyme that regulates lipid composition, has been shown to contribute to the execution of ferroptosis, but its role in I/R needs clarification. In the present study, we used rosiglitazone (ROSI) and siRNA to inhibit ischemia/hypoxia-induced ACSL4 in vivo and in vitro. The results demonstrated that ACSL4 inhibition before reperfusion protected against ferroptosis and cell death. Further investigation revealed that special protein 1 (Sp1) was a crucial transcription factor that increased ACSL4 transcription by binding to the ACSL4 promoter region. Collectively, this study demonstrates that ferroptosis is closely associated with intestinal I/R injury, and that ACSL4 has a critical role in this lethal process. Sp1 is an important factor in promoting ACSL4 expression. These results suggest a unique and effective mechanistic approach for intestinal I/R injury prevention and treatment.

Topics: Animals; Caco-2 Cells; Cell Line, Tumor; Coenzyme A Ligases; DNA-Binding Proteins; Ferroptosis; Humans; Intestines; Lipid Peroxidation; Mice; Mice, Inbred C57BL; Models, Animal; Promoter Regions, Genetic; Quinoxalines; Reactive Oxygen Species; Reperfusion Injury; Rosiglitazone; Sp1 Transcription Factor; Spiro Compounds

Ferroptosis is a non-apoptotic form of cell death induced by small molecules in specific tumour types, and in engineered cells overexpressing oncogenic RAS. Yet, its relevance in non-transformed cells and tissues is unexplored and remains enigmatic. Here, we provide direct genetic evidence that the knockout of glutathione peroxidase 4 (Gpx4) causes cell death in a pathologically relevant form of ferroptosis. Using inducible Gpx4(-/-) mice, we elucidate an essential role for the glutathione/Gpx4 axis in preventing lipid-oxidation-induced acute renal failure and associated death. We furthermore systematically evaluated a library of small molecules for possible ferroptosis inhibitors, leading to the discovery of a potent spiroquinoxalinamine derivative called Liproxstatin-1, which is able to suppress ferroptosis in cells, in Gpx4(-/-) mice, and in a pre-clinical model of ischaemia/reperfusion-induced hepatic damage. In sum, we demonstrate that ferroptosis is a pervasive and dynamic form of cell death, which, when impeded, promises substantial cytoprotection.

Topics: Acute Kidney Injury; Animals; Apoptosis; Arachidonate 12-Lipoxygenase; Arachidonate 15-Lipoxygenase; Cardiolipins; Cell Line; Glutathione Peroxidase; Humans; Imidazoles; In Situ Nick-End Labeling; Indoles; Kidney; Lipid Peroxidation; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Mitochondria; Peroxidases; Phosphatidylcholines; Phosphatidylethanolamines; Phospholipid Hydroperoxide Glutathione Peroxidase; Quinoxalines; Reperfusion Injury; Spiro Compounds