RESUMO
BACKGROUND: This study evaluated the effects of concurrent isolated training (T) or training combined with the antioxidant N-acetylcysteine (NAC) on cardiac remodeling and oxidative stress in spontaneously hypertensive rats (SHR). METHODS: Six-month-old male SHR were divided into sedentary (S, n = 12), concurrent training (T, n = 13), sedentary supplemented with NAC (SNAC, n = 13), and concurrent training with NAC supplementation (TNAC, n = 14) groups. T and TNAC rats were trained three times a week on a treadmill and ladder; NAC supplemented groups received 120 mg/kg/day NAC in rat chow for eight weeks. Myocardial antioxidant enzyme activity and lipid hydroperoxide concentration were assessed by spectrophotometry. Gene expression of NADPH oxidase subunits Nox2, Nox4, p22 phox, and p47 phox was evaluated by real time RT-PCR. Statistical analysis was performed using ANOVA and Bonferroni or Kruskal-Wallis and Dunn. RESULTS: Echocardiogram showed concentric remodeling in TNAC, characterized by increased relative wall thickness (S 0.40 ± 0.04; T 0.39 ± 0.03; SNAC 0.40 ± 0.04; TNAC 0.43 ± 0.04 *; * p < 0.05 vs T and SNAC) and diastolic posterior wall thickness (S 1.50 ± 0.12; T 1.52 ± 0.10; SNAC 1.56 ± 0.12; TNAC 1.62 ± 0.14 * mm; * p < 0.05 vs T), with improved contractile function (posterior wall shortening velocity: S 39.4 ± 5.01; T 36.4 ± 2.96; SNAC 39.7 ± 3.44; TNAC 41.6 ± 3.57 * mm/s; * p < 0.05 vs T). Myocardial lipid hydroperoxide concentration was lower in NAC treated groups (S 210 ± 48; T 182 ± 43; SNAC 159 ± 33 *; TNAC 110 ± 23 *# nmol/g tissue; * p < 0.05 vs S, # p < 0.05 vs T and SNAC). Nox 2 and p22 phox expression was higher and p47 phox lower in T than S [S 1.37 (0.66-1.66); T 0.78 (0.61-1.04) *; SNAC 1.07 (1.01-1.38); TNAC 1.06 (1.01-1.15) arbitrary units; * p < 0.05 vs S]. NADPH oxidase subunits did not differ between TNAC, SNAC, and S groups. CONCLUSION: N-acetylcysteine supplementation alone reduces oxidative stress in untreated spontaneously hypertensive rats. The combination of N-acetylcysteine and concurrent exercise further decreases oxidative stress. However, the lower oxidative stress does not translate into improved cardiac remodeling and function in untreated spontaneously hypertensive rats.
Assuntos
Acetilcisteína , Hipertensão , NADPH Oxidases , Estresse Oxidativo , Ratos Endogâmicos SHR , Remodelação Ventricular , Animais , Masculino , Estresse Oxidativo/efeitos dos fármacos , Acetilcisteína/farmacologia , Remodelação Ventricular/efeitos dos fármacos , Hipertensão/fisiopatologia , Hipertensão/tratamento farmacológico , Hipertensão/metabolismo , NADPH Oxidases/metabolismo , NADPH Oxidases/genética , Ratos , Antioxidantes/farmacologia , Condicionamento Físico Animal , Modelos Animais de Doenças , NADPH Oxidase 2/metabolismo , NADPH Oxidase 2/genética , NADPH Oxidase 4/metabolismo , NADPH Oxidase 4/genética , Glicoproteínas de Membrana/metabolismo , Glicoproteínas de Membrana/genética , Miocárdio/metabolismo , Miocárdio/patologia , Peróxidos Lipídicos/metabolismo , Função Ventricular Esquerda/efeitos dos fármacos , Suplementos Nutricionais , Hipertrofia Ventricular Esquerda/fisiopatologia , Hipertrofia Ventricular Esquerda/prevenção & controle , Hipertrofia Ventricular Esquerda/metabolismoRESUMO
The accumulation of lipid hydroperoxides (LOOHs) has long been associated with numerous pathologies and has more recently been shown to drive a specific type of cell death known as ferroptosis. In competition with their detoxification by glutathione peroxidases, LOOHs can react with both one-electron reductants and one-electron oxidants to afford radicals that initiate lipid peroxidation (LPO) chain reactions leading to more LOOH. These radicals can alternatively undergo a variety of (primarily unimolecular) reactions leading to electrophilic species that destabilize the membrane and/or react with cellular nucleophiles. While some reaction mechanisms leading to lipid-derived electrophiles have been known for some time, others have only recently been elucidated. Since LOOH (and related peroxides, LOOL) undergo these various reactions at different rates to afford distinct product distributions specific to their structures, not all LOOHs (and LOOLs) should be equivalently problematic for the cell - be it in their propensity to initiate further LPO or fragment to electrophiles, drive membrane permeabilization and eventual cell death. Herein we briefly review the fates of LOOH and discuss how they may contribute to the modulation of cell sensitivity to ferroptosis by different lipids.
Assuntos
Ferroptose , Peroxidação de Lipídeos , Peróxidos Lipídicos , Humanos , Peróxidos Lipídicos/metabolismo , AnimaisRESUMO
As an iron dependent regulatory cell death process driven by excessive lipid peroxides (LPO), ferroptosis is recognized as a powerful weapon for pancreatic cancer (PC) therapy. However, the tumor microenvironment (TME) with hypoxia and elevated glutathione (GSH) expression not only inhibits LPO production, but also induces glutathione peroxidase 4 (GPX4) mediated LPO clearance, which greatly compromise the therapeutic outcomes of ferroptosis. To address these issues, herein, a novel triple-enhanced ferroptosis amplifier (denoted as Zal@HM-PTBC) is rationally designed. After intravenous injection, the overexpressed H2O2/GSH in TME induces the collapse of Zal@HM-PTBC and triggers the production of oxygen and reactive oxygen species (ROS), which synergistically amplify the degree of lipid peroxidation (broaden sources). Concurrently, GSH consumption because of the degradation of the hollow manganese dioxide (HM) significantly weakens the activity of GPX4, resulting in a decrease in LPO clearance (reduce expenditure). Moreover, the loading and site-directed release of zalcitabine further promotes autophagy-dependent LPO accumulation (enhance effectiveness). Both in vitro and in vivo results validated that the ferroptosis amplifier demonstrated superior specificity and favorable therapeutic responses. Overall, this triple-enhanced LPO accumulation strategy demonstrates the ability to facilitate the efficacy of ferroptosis, injecting vigorous vitality into the treatment of PC.
Assuntos
Ferroptose , Glutationa , Peróxidos Lipídicos , Neoplasias Pancreáticas , Ferroptose/efeitos dos fármacos , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/patologia , Neoplasias Pancreáticas/metabolismo , Animais , Peróxidos Lipídicos/metabolismo , Humanos , Linhagem Celular Tumoral , Glutationa/metabolismo , Camundongos , Compostos de Manganês/química , Óxidos/química , Espécies Reativas de Oxigênio/metabolismo , Fosfolipídeo Hidroperóxido Glutationa Peroxidase/metabolismo , Microambiente Tumoral/efeitos dos fármacos , Camundongos Nus , Peróxido de Hidrogênio/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Camundongos Endogâmicos BALB CRESUMO
The neural cell death in cerebral infarction is suggested to be ferroptosis-like cell death, involving the participation of 15-lipoxygenase (15-LOx). Ferroptosis is induced by lipid radical species generated through the one-electron reduction of lipid hydroperoxides, and it has been shown to propagate intracellularly and intercellularly. At lower oxygen concentration, it appeared that both regiospecificity and stereospecificity of conjugated diene moiety in lipoxygenase-catalysed lipid hydroperoxidation are drastically lost. As a result, in the reaction with linoleic acid, the linoleate 9-peroxyl radical-ferrous lipoxygenase complex dissolves into the linoleate 9-peroxyl radical and ferrous 15-lipoxygenase. Subsequently, the ferrous 15-lipoxygenase then undergoes one-electron reduction of 13-hydroperoxy octadecadienoic acid, generating an alkoxyl radical (pseudoperoxidase reaction). A part of the produced lipid alkoxyl radicals undergoes cleavage of C-C bonds, liberating small molecular hydrocarbon radicals. Particularly, in ω-3 polyunsaturated fatty acids, which are abundant in the vascular and nervous systems, the liberation of small molecular hydrocarbon radicals was more pronounced compared to ω-6 polyunsaturated fatty acids. The involvement of these small molecular hydrocarbon radicals in the propagation of membrane lipid damage is suggested.
Assuntos
Araquidonato 15-Lipoxigenase , Ácido Linoleico , Peróxidos , Ácido Linoleico/metabolismo , Ácidos Graxos Insaturados/química , Ácidos Graxos Insaturados/metabolismo , Peróxidos Lipídicos/metabolismo , Lipoxigenase/metabolismo , Hidrocarbonetos , Morte Celular , Oxigênio/metabolismo , Radicais Livres/metabolismoRESUMO
The suppression of ferroptosis is emerging as a promising therapeutic strategy for effectively treating a wide range of diseases, including neurodegenerative disorders, organ ischemia-reperfusion injury, and inflammatory conditions. However, the clinical utility of ferroptosis inhibitors is significantly impeded by the limited availability of rational drug designs. In our previous study, we successfully unraveled the efficacy of ferrostatin-1 (Fer-1) attributed to the synergistic effect of its ortho-diamine (-NH) moiety. In this study, we present the discovery of the ortho-hydroxyl-amino moiety as a novel scaffold for ferroptosis inhibitors, employing quantum chemistry as well as in vitro and in vivo assays. 2-amino-6-methylphenol derivatives demonstrated remarkable inhibition of RSL3-induced ferroptosis, exhibiting EC50 values ranging from 25 nM to 207 nM. These compounds do not appear to modulate iron homeostasis or lipid reactive oxygen species (ROS) generation pathways. Nevertheless, they effectively prevent the accumulation of lipid peroxides in living cells. Furthermore, compound 13 exhibits good in vivo activities as it effectively protect mice from kidney ischemia-reperfusion injury. In summary, compound 13 has been identified as a potent ferroptosis inhibitor, warranting further investigation as a promising lead compound.
Assuntos
Peróxidos Lipídicos , Traumatismo por Reperfusão , Animais , Camundongos , Peroxidação de Lipídeos , Peróxidos Lipídicos/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Traumatismo por Reperfusão/tratamento farmacológico , Fenóis/farmacologiaRESUMO
Ferroptosis is a new form of regulated cell death caused by iron-dependent accumulation of lethal polyunsaturated phospholipids peroxidation. It has received considerable attention owing to its putative involvement in a wide range of pathophysiological processes such as organ injury, cardiac ischemia/reperfusion, degenerative disease and its prevalence in plants, invertebrates, yeasts, bacteria, and archaea. To counter ferroptosis, living organisms have evolved a myriad of intrinsic efficient defense systems, such as cyst(e)ine-glutathione-glutathione peroxidase 4 system (cyst(e)ine-GPX4 system), guanosine triphosphate cyclohydrolase 1/tetrahydrobiopterin (BH4) system (GCH1/BH4 system), ferroptosis suppressor protein 1/coenzyme Q10 system (FSP1/CoQ10 system), and so forth. Among these, GPX4 serves as the only enzymatic protection system through the reduction of lipid hydroperoxides, while other defense systems ultimately rely on small compounds to scavenge lipid radicals and prevent ferroptotic cell death. In this article, we systematically summarize the chemical biology of lipid radical trapping process by endogenous chemicals, such as coenzyme Q10 (CoQ10), BH4, hydropersulfides, vitamin K, vitamin E, 7-dehydrocholesterol, with the aim of guiding the discovery of novel ferroptosis inhibitors.
Assuntos
Cistos , Ubiquinona , Humanos , Ubiquinona/metabolismo , Peroxidação de Lipídeos , Morte Celular , Peróxidos Lipídicos/metabolismoRESUMO
Purpose: Acute liver failure (ALF) is a clinically fatal disease that leads to the rapid loss of normal liver function. Acetaminophen (APAP) is a leading cause of drug-induced ALF. Ferroptosis, defined as iron-dependent cell death associated with lipid peroxide accumulation, has been shown to be strongly associated with APAP-induced liver injury. Growth arrest-specific 1 (GAS1) is a growth arrest-specific gene, which is closely related to the inhibition of cell growth and promotion of apoptosis. However, the functional role and underlying mechanism of GAS1 in APAP-induced ferroptosis remain unknown. Methods: We established liver-specific overexpression of GAS1 (GAS1AAV8-OE) mice and the control (GAS1AAV8-vector) mice by tail vein injection of male mice with adeno-associated virus. APAP at 500 mg/kg was intraperitoneally injected into these two groups of mice to induce acute liver failure. The shRNA packaged by the lentivirus inhibits GAS1 gene expression in human hepatoma cell line HepaRG (HepaRG-shNC and HepaRG-shGAS1-2) and primary hepatocytes of mice with liver-specific overexpression of GAS1 were isolated and induced by APAP in vitro to further investigate the regulatory role of GAS1 in APAP-induced acute liver failure. Results: APAP-induced upregulation of ferroptosis, levels of lipid peroxides and reactive oxygen species, and depletion of glutathione were effectively alleviated by the ferroptosis inhibitor, ferrostatin-1, and downregulation of GAS1 expression. GAS1 overexpression promoted ferroptosis-induced lipid peroxide accumulation via p53, inhibiting its downstream target, solute carrier family 7 member 11. Conclusion: Collectively, our findings suggest that GAS1 overexpression plays a key role in aggravating APAP-induced acute liver injury by promoting ferroptosis-induced accumulation of lipid peroxides.
Assuntos
Ferroptose , Falência Hepática Aguda , Animais , Humanos , Masculino , Camundongos , Acetaminofen/toxicidade , Proteínas de Ciclo Celular/metabolismo , Ferroptose/genética , Proteínas Ligadas por GPI/metabolismo , Hepatócitos/metabolismo , Peróxidos Lipídicos/metabolismo , Fígado , Falência Hepática Aguda/induzido quimicamente , Falência Hepática Aguda/genética , Falência Hepática Aguda/metabolismo , Camundongos Endogâmicos C57BLRESUMO
A BAX- and mitochondria-dependent production of reactive oxygen species (ROS) and reactive species (reactive nitrogen species, RNS) lying downstream of these ROS occurs in apoptotic and nonapoptotic mouse sympathetic neurons and cerebellar granule cells in cell culture. These ROS have been shown to lie downstream of caspase 3 in mouse sympathetic neurons. Here we show that BAX is necessary for similar ROS production in apoptotic and nonapoptotic mouse cortical neurons in cell culture and that it also positively regulates oxidative stress in the brains of mice of different ages. Brains from mice with genetically reduced levels of mitochondrial superoxide dismutase 2 (SOD2) exhibited elevated levels of DNA strand breaks consistent with oxidative damage. Lipid peroxides were also elevated at some ages in comparison to the brains of wild type animals. BAX deletion in these mice reduced both brain DNA strand breaks and lipid peroxide levels to well below those of wild type animals. Deletion of caspase 3 greatly reduced age-augmented levels of brain oxidative stress markers including lipid peroxides, oxidized DNA, and nitrosylated proteins. These findings indicate that BAX contributes to ROS production in mouse cortical neurons, to oxidative stress their brains, and that this effect is likely mediated via caspase 3 activity.
Assuntos
Apoptose , Peróxidos Lipídicos , Camundongos , Animais , Espécies Reativas de Oxigênio/metabolismo , Caspase 3/metabolismo , Proteína X Associada a bcl-2/metabolismo , Peróxidos Lipídicos/metabolismo , Apoptose/fisiologia , Estresse Oxidativo/fisiologia , Neurônios/metabolismo , Encéfalo/metabolismo , DNA/metabolismoRESUMO
Oncocytic (Hürthle cell) carcinoma of the thyroid (HCC) is genetically characterized by complex I mitochondrial DNA mutations and widespread chromosomal losses. Here, we utilize RNA sequencing and metabolomics to identify candidate molecular effectors activated by these genetic drivers. We find glutathione biosynthesis, amino acid metabolism, mitochondrial unfolded protein response, and lipid peroxide scavenging to be increased in HCC. A CRISPR-Cas9 knockout screen in a new HCC model reveals which pathways are key for fitness, and highlights loss of GPX4, a defense against lipid peroxides and ferroptosis, as a strong liability. Rescuing complex I redox activity with the yeast NADH dehydrogenase (NDI1) in HCC cells diminishes ferroptosis sensitivity, while inhibiting complex I in normal thyroid cells augments ferroptosis induction. Our work demonstrates unmitigated lipid peroxide stress to be an HCC vulnerability that is mechanistically coupled to the genetic loss of mitochondrial complex I activity. SIGNIFICANCE: HCC harbors abundant mitochondria, mitochondrial DNA mutations, and chromosomal losses. Using a CRISPR-Cas9 screen inspired by transcriptomic and metabolomic profiling, we identify molecular effectors essential for cell fitness. We uncover lipid peroxide stress as a vulnerability coupled to mitochondrial complex I loss in HCC. See related article by Frank et al., p. 1884. This article is highlighted in the In This Issue feature, p. 1749.
Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Glândula Tireoide/metabolismo , Carcinoma Hepatocelular/metabolismo , Peróxidos Lipídicos/metabolismo , Fermentação , Células Oxífilas/metabolismo , Neoplasias Hepáticas/metabolismo , DNA Mitocondrial/genética , DNA Mitocondrial/metabolismoRESUMO
Lipid hydroperoxides (LOOHs) are reactive intermediates that arise during peroxidation of unsaturated phospholipids, glycolipids and cholesterol in biological membranes and lipoproteins. Non-physiological lipid peroxidation (LPO) typically occurs under oxidative stress conditions associated with pathologies such as atherogenesis, neurodegeneration, and carcinogenesis. As key intermediates in the LPO process, LOOHs are susceptible to one-electron versus two-electron reductive turnover, the former exacerbating membrane or lipoprotein damage/dysfunction and the latter diminishing it. A third possible LOOH fate is translocation to an acceptor membrane/lipoprotein, where one- or two-electron reduction may then ensue. In the case of cholesterol (Ch)-derived hydroperoxides (ChOOHs), translocation can be specifically stimulated by StAR family trafficking proteins, which are normally involved in Ch homeostasis and Ch-mediated steroidogenesis. In this review, we discuss how these processes can be impaired by StAR-mediated ChOOH and Ch co-trafficking to mitochondria of vascular macrophages and steroidogenic cells, respectively. The protective effects of endogenous selenoperoxidase, GPx4, are also discussed. This is the first known example of detrimental ChOOH transfer via a natural Ch trafficking pathway and inhibition thereof by GPx4.
Assuntos
Peróxidos Lipídicos , Estresse Oxidativo , Peróxidos Lipídicos/metabolismo , Peroxidação de Lipídeos , Colesterol/metabolismo , Membrana Celular/metabolismoRESUMO
BACKGRUOUND: Ferroptosis, which is caused by an iron-dependent accumulation of lipid hydroperoxides, is a type of cell death linked to diabetic kidney disease (DKD). Previous research has shown that fatty acid binding protein 4 (FABP4) is involved in the regulation of ferroptosis in diabetic retinopathy. The present study was constructed to explore the role of FABP4 in the regulation of ferroptosis in DKD. METHODS: We first detected the expression of FABP4 and proteins related to ferroptosis in renal biopsies of patients with DKD. Then, we used a FABP4 inhibitor and small interfering RNA to investigate the role of FABP4 in ferroptosis induced by high glucose in human renal proximal tubular epithelial (HG-HK2) cells. RESULTS: In kidney biopsies of DKD patients, the expression of FABP4 was elevated, whereas carnitine palmitoyltransferase-1A (CP-T1A), glutathione peroxidase 4, ferritin heavy chain, and ferritin light chain showed reduced expression. In HG-HK2 cells, the induction of ferroptosis was accompanied by an increase in FABP4. Inhibition of FABP4 in HG-HK2 cells changed the redox state, sup-pressing the production of reactive oxygen species, ferrous iron (Fe2+), and malondialdehyde, increasing superoxide dismutase, and reversing ferroptosis-associated mitochondrial damage. The inhibition of FABP4 also increased the expression of CPT1A, reversed lipid deposition, and restored impaired fatty acid ß-oxidation. In addition, the inhibition of CPT1A could induce ferroptosis in HK2 cells. CONCLUSION: Our results suggest that FABP4 mediates ferroptosis in HG-HK2 cells by inhibiting fatty acid ß-oxidation.
Assuntos
Ferroptose , Humanos , Proteínas de Ligação a Ácido Graxo/genética , Proteínas de Ligação a Ácido Graxo/metabolismo , Ácidos Graxos , Glucose/farmacologia , Ferro/metabolismo , Peróxidos Lipídicos/metabolismoRESUMO
Evodiamine (EVO) exhibits anti-cancer activity through the inhibition of cell proliferation; however, little is known about its underlying mechanism. To determine whether ferroptosis is involved in the therapeutic effects of EVO, we investigated critical factors, such as lipid peroxidation levels and glutathione peroxidase 4 (GPX4) expression, under EVO treatment. Our results showed that EVO inhibited the cell proliferation of poorly differentiated, high-grade bladder cancer TCCSUP cells in a dose- and time-dependent manner. Lipid peroxides were detected by fluorescence microscopy after cancer cell exposure to EVO. GPX4, which catalyzes the conversion of lipid peroxides to prevent cells from undergoing ferroptosis, was decreased dose-dependently by EVO treatment. Given the features of iron dependency and lipid-peroxidation-driven death in ferroptosis, the iron chelator deferoxamine (DFO) was used to suppress EVO-induced ferroptosis. The lipid peroxide level significantly decreased when cells were treated with DFO prior to EVO treatment. DFO also attenuated EVO-induced cell death. Co-treatment with a pan-caspase inhibitor or necroptosis inhibitor with EVO did not alleviate cancer cell death. These results indicate that EVO induces ferroptosis rather than apoptosis or necroptosis. Furthermore, EVO suppressed the migratory ability, decreased the expression of mesenchymal markers, and increased epithelial marker expression, determined by a transwell migration assay and Western blotting. The TCCSUP bladder tumor xenograft tumor model confirmed the effects of EVO on the inhibition of tumor growth and EMT. In conclusion, EVO is a novel inducer for activating the ferroptosis of bladder cancer cells and may be a potential therapeutic agent for bladder cancer.
Assuntos
Ferroptose , Neoplasias da Bexiga Urinária , Humanos , Glutationa/metabolismo , Glutationa Peroxidase/metabolismo , Peroxidação de Lipídeos , Peróxidos Lipídicos/metabolismo , Fosfolipídeo Hidroperóxido Glutationa Peroxidase/metabolismo , Neoplasias da Bexiga Urinária/tratamento farmacológico , AnimaisRESUMO
The ongoing metabolic and microbicidal pathways that support and protect cellular life generate potentially damaging reactive oxygen species (ROS). To counteract damage, cells express peroxidases, which are antioxidant enzymes that catalyze the reduction of oxidized biomolecules. Glutathione peroxidase 4 (GPX4) is the major hydroperoxidase specifically responsible for reducing lipid peroxides; this homeostatic mechanism is essential, and its inhibition causes a unique type of lytic cell death, ferroptosis. The mechanism(s) that lead to cell lysis in ferroptosis, however, are unclear. We report that the lipid peroxides formed during ferroptosis accumulate preferentially at the plasma membrane. Oxidation of surface membrane lipids increased tension on the plasma membrane and led to the activation of Piezo1 and TRP channels. Oxidized membranes thus became permeable to cations, ultimately leading to the gain of cellular Na+ and Ca2+ concomitant with loss of K+. These effects were reduced by deletion of Piezo1 and completely inhibited by blocking cation channel conductance with ruthenium red or 2-aminoethoxydiphenyl borate (2-APB). We also found that the oxidation of lipids depressed the activity of the Na+/K+-ATPase, exacerbating the dissipation of monovalent cation gradients. Preventing the changes in cation content attenuated ferroptosis. Altogether, our study establishes that increased membrane permeability to cations is a critical step in the execution of ferroptosis and identifies Piezo1, TRP channels, and the Na+/K+-ATPase as targets/effectors of this type of cell death.
Assuntos
Ferroptose , Peróxidos Lipídicos , Cátions , Glutationa Peroxidase/metabolismo , Peroxidação de Lipídeos/fisiologia , Peróxidos Lipídicos/metabolismo , Fosfolipídeo Hidroperóxido Glutationa Peroxidase/metabolismo , Proteínas de Membrana/metabolismoRESUMO
Reactive oxygen species (ROS) accumulation is a cardinal feature of skeletal muscle atrophy. ROS refers to a collection of radical molecules whose cellular signals are vast, and it is unclear which downstream consequences of ROS are responsible for the loss of muscle mass and strength. Here, we show that lipid hydroperoxides (LOOH) are increased with age and disuse, and the accumulation of LOOH by deletion of glutathione peroxidase 4 (GPx4) is sufficient to augment muscle atrophy. LOOH promoted atrophy in a lysosomal-dependent, proteasomal-independent manner. In young and old mice, genetic and pharmacological neutralization of LOOH or their secondary reactive lipid aldehydes robustly prevented muscle atrophy and weakness, indicating that LOOH-derived carbonyl stress mediates age- and disuse-induced muscle dysfunction. Our findings provide novel insights for the role of LOOH in sarcopenia including a therapeutic implication by pharmacological suppression.
Assuntos
Sarcopenia , Camundongos , Animais , Sarcopenia/patologia , Peróxidos Lipídicos/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Atrofia Muscular/metabolismo , Atrofia Muscular/patologia , Músculo Esquelético/metabolismo , Estresse OxidativoRESUMO
INTRODUCTION: Alterations in red blood cell deformability (RBC-df) provide important information for the diagnosis of various diseases. AIM: We evaluated individual differences of lipopolysaccharide (LPS)-induced oxidative damage of RBC-df and analyzed the correlation between RBC-df and biochemical parameters. METHODS: A microfluidic chip was developed to detect inter-individual variability of different concentrations of LPS-induced oxidative damage of RBC-df in 9 healthy volunteers. The relationships between various biochemical indicators (Na+-K+-ATPase activity, lipid peroxide (LPO) content, glutathione peroxidase (GSH-PX) activity, catalase (CAT) activity, superoxide dismutase (SOD) activity, adenosine triphosphate (ATP) content, and hemoglobin (HB) content) and RBCsdf were investigated. RESULTS: The obvious inter-individual variability of LPS-induced oxidative damage of RBC-df was revealed. The Na+-K+-ATPase activity, LPO content, GSH-PX activity, and CAT activity of RBCs showed significant correlations with RBC-df (P < 0.05). CONCLUSION: Oxidative damage and energy metabolism are the critical factors of RBC-df impairment induced by LPS, and the individual dependence on RBC-df is an important indicator for the treatment of infection-associated sepsis since antibiotics can kill pathogenic bacteria, which results in the release of LPS from the cell wall.
Assuntos
Lipopolissacarídeos , Microfluídica , Eritrócitos , Antioxidantes/metabolismo , Peróxidos Lipídicos/metabolismo , Adenosina Trifosfatases/metabolismoRESUMO
This study aimed to investigate the effect of the sympatholytic drug moxonidine on atherosclerosis. The effects of moxonidine on oxidised low-density lipoprotein (LDL) uptake, inflammatory gene expression and cellular migration were investigated in vitro in cultured vascular smooth muscle cells (VSMCs). The effect of moxonidine on atherosclerosis was measured by examining aortic arch Sudan IV staining and quantifying the intima-to-media ratio of the left common carotid artery in apolipoprotein E-deficient (ApoE-/-) mice infused with angiotensin II. The levels of circulating lipid hydroperoxides in mouse plasma were measured by ferrous oxidation-xylenol orange assay. Moxonidine administration increased oxidised LDL uptake by VSMCs via activation of α2 adrenoceptors. Moxonidine increased the expression of LDL receptors and the lipid efflux transporter ABCG1. Moxonidine inhibited mRNA expression of inflammatory genes and increased VSMC migration. Moxonidine administration to ApoE-/- mice (18 mg/kg/day) decreased atherosclerosis formation in the aortic arch and left common carotid artery, associated with increased plasma lipid hydroperoxide levels. In conclusion, moxonidine inhibited atherosclerosis in ApoE-/- mice, which was accompanied by an increase in oxidised LDL uptake by VSMCs, VSMC migration, ABCG1 expression in VSMCs and lipid hydroperoxide levels in the plasma.
Assuntos
Aterosclerose , Imidazóis , Lipoproteínas LDL , Músculo Liso Vascular , Animais , Camundongos , Apolipoproteínas E/metabolismo , Aterosclerose/metabolismo , Proliferação de Células , Células Cultivadas , Peróxidos Lipídicos/metabolismo , Lipoproteínas LDL/metabolismo , Camundongos Endogâmicos C57BL , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/metabolismo , Miócitos de Músculo Liso/metabolismo , Imidazóis/farmacologiaRESUMO
As a novel pattern of regulated cell death (RCD), Ferroptosis is induced by lipid peroxide-dependent iron accumulation, which is associated with reactive oxygen species (ROS). Ferroptosis regulates cell death via ROS accumulation-related lipid peroxides accumulation, affecting the structure and polarity of lipid droplets (LDs). Compared with reactive fluorescent probes, environment-sensitive fluorescent probes allow for maximum preservation of the intracellular environment while monitoring metabolic activity in situ, resulting in more accurate monitoring results. In this study, a polarity-sensitive two-photon fluorescent probe with anchoring capacity in LDs, LIP-Pola, is reported and applied to monitor the polarity of LDs during cell Ferroptosis by in situ imaging analysis of cell Ferroptosis via LDs polarity changes. Additionally, Paclitaxel is shown to increase the Ferroptosis level from data of cells and tumor tissue sections, suggesting that Paclitaxel may deactivate tumor cells by regulating Ferroptosis.
Assuntos
Antineoplásicos , Ferroptose , Gotículas Lipídicas/metabolismo , Espécies Reativas de Oxigênio , Corantes Fluorescentes/química , Peróxidos Lipídicos/metabolismo , Peróxidos Lipídicos/farmacologia , Antineoplásicos/farmacologia , Antineoplásicos/metabolismoRESUMO
Ferroptosis, the iron-dependent, lipid peroxide-mediated cell death, has garnered attention due to its critical involvement in crucial physiological and pathological cellular processes. Indeed, several studies have attributed its role in developing a range of disorders, including diabetes. As accumulating evidence further the understanding of ferroptotic mechanisms, the impact this specialized mode of cell death has on diabetic pathogenesis is still unclear. Several in vivo and in vitro studies have highlighted the association of ferroptosis with beta-cell death and insulin resistance, supported by observations of marked alterations in ferroptotic markers in experimental diabetes models. The constant improvement in understanding ferroptosis in diabetes has demonstrated it as a potential therapeutic target in diabetic management. In this regard, ferroptosis inhibitors promise to rescue pancreatic beta-cell function and alleviate diabetes and its complications. This review article elucidates the key ferroptotic pathways that mediate beta-cell death in diabetes, and its complications. In particular, we share our insight into the cross talk between ferroptosis and other hallmark pathogenic mediators such as oxidative and endoplasmic reticulum stress regulators relevant to diabetes progression. Further, we extensively summarize the recent developments on the role of ferroptosis inhibitors and their therapeutic action in alleviating diabetes and its complications.
Assuntos
Diabetes Mellitus , Ferroptose , Ferroptose/genética , Peroxidação de Lipídeos , Morte Celular , Ferro/metabolismo , Peróxidos Lipídicos/metabolismo , Diabetes Mellitus/tratamento farmacológico , Diabetes Mellitus/genéticaRESUMO
Lipid peroxidation is a primary event in plant roots exposed to aluminum (Al) toxicity, which leads to the formation of reactive aldehydes. Current evidence demonstrates that the resultant aldehydes are integrated components of cellular damage in plants. Here, we investigated the roles of aldehydes in mediating Al-induced damage, particularly cell death, using two wheat genotypes with different Al resistances. Aluminum treatment significantly induced cell death, which was accompanied by decreased root activity and cell length. Al-induced cell death displayed granular nuclei and internucleosomal fragmentation of nuclear DNA, suggesting these cells underwent programmed cell death (PCD). During this process, caspase-3-like protease activity was extensively enhanced and showed a significant difference between these two wheat genotypes. Further experiments showed that Al-induced cell death was positively correlated with aldehydes levels. Al-induced representative diagnostic markers for PCD, such as TUNEL-positive nuclei and DNA fragmentation, were further enhanced by the aldehyde donor (E)-2-hexenal, but significantly suppressed by the aldehyde scavenger carnosine. As the crucial executioner of Al-induced PCD, the activity of caspase-3-like protease was further enhanced by (E)-2-hexenal but inhibited by carnosine in wheat roots. These results suggest that reactive aldehydes sourced from lipid peroxidation mediate Al-initiated PCD probably through activating caspase-3-like protease in wheat roots.
Assuntos
Alumínio , Carnosina , Alumínio/toxicidade , Peróxidos Lipídicos/metabolismo , Triticum/genética , Triticum/metabolismo , Caspase 3/metabolismo , Carnosina/metabolismo , Raízes de Plantas/metabolismo , Apoptose , Aldeídos/toxicidade , Aldeídos/metabolismoRESUMO
Retinal ganglion cell (RGC) death is a hallmark of traumatic optic neuropathy, glaucoma, and other optic neuropathies that result in irreversible vision loss. However, therapeutic strategies for rescuing RGC loss still remain challenging, and the molecular mechanism underlying RGC loss has not been fully elucidated. Here, we highlight the role of ferroptosis, a non-apoptotic form of programmed cell death characterized by iron-dependent lethal lipid peroxides accumulation, in RGC death using an experimental model of glaucoma and optic nerve crush (ONC). ONC treatment resulted in significant downregulation of glutathione peroxidase 4 (GPx4) and system xc(-) cystine/glutamate antiporter (xCT) in the rat retina, accompanied by increased lipid peroxide and iron levels. The reduction of GPx4 expression in RGCs after ONC was confirmed by laser-capture microdissection and PCR. Transmission electron microscopy (TEM) revealed alterations in mitochondrial morphology, including increased membrane density and reduced mitochondrial cristae in RGCs after ONC. Notably, the ferroptosis inhibitor ferrostatin-1 (Fer-1) significantly promoted RGC survival and preserved retinal function in ONC and microbead-induced glaucoma mouse models. In addition, compared to the apoptosis inhibitor Z-VAD-FMK, Fer-1 showed better effect in rescuing RGCs death in ONC retinas. Mechanistically, we found the downregulation of GPx4 mainly occurred in the mitochondrial compartment, accompanied by increased mitochondrial reactive oxygen species (ROS) and lipid peroxides. The mitochondria-selective antioxidant MitoTEMPO attenuated RGC loss after ONC, implicating mitochondrial ROS and lipid peroxides as major mechanisms in ferroptosis-induced RGC death in ONC retinas. Notably, administering Fer-1 effectively prevented the production of mitochondrial lipid peroxides, the impairment of mitochondrial adenosine 5'-triphosphate (ATP) production, and the downregulation of mitochondrial genes, such as mt-Cytb and MT-ATP6, in ONC retinas. Our findings suggest that ferroptosis is a major form of regulated cell death for RGCs in experimental glaucoma and ONC models and suggesting targeting mitochondria-dependent ferroptosis as a protective strategy for RGC injuries in optic neuropathies.