Free Radical Biology and Medicine最新文献

Off-target neuronal injury is a serious side-effect observed in cancer survivors. It has previously been shown that pediatric acute lymphoblastic leukemia (ALL) survivors have a decline in neurocognition compared to healthy age-matched counterparts. Elevated oxidative stress has been documented to be a mediator in off-target tissue damage in cancer survivors. Early detection of oxidative stress markers may provide an opportunity to prevent off-target tissue damage. Extracellular vesicles (EVs) have surfaced as a potential diagnostic tool due to molecular cargo they contain. We investigated the potential for EVs to be a sensitive indicator of oxidative stress and off-target tissue damage by isolating EVs from pediatric ALL patients throughout their first 2 months of treatment. EVs were measured throughout the collection points for: 1) number of EV particles generated using nanoparticle tracking analysis (NTA); 2) markers of neurons (NeuN), astrocyte activation (GFAP), neuronal stability (BDNF), 3) markers of pre-B cell ALL (CD19 and CD22); and) 4-hydroxy-2-nonenal (HNE) adducted proteins. HNE protein adductions were measured in the patient sera and CSF. Pro-inflammatory cytokine levels were also measured in patient sera because of their contribution to oxidative stress and neuronal injury. Our results: 1) demonstrate EVs are a sensitive indicator of oxidative damage; 2) suggest EVs as a marker of a decline in neuronal stability; and 3) show the presence of leukemia has a greater contribution to pro-inflammatory cytokine production in the patient's serum than the cancer treatment. Specifically, we observed a significant decrease in cytokine levels (e.g., TNF-α, IL-1β, IL-6, and IL-8) following the initiation of treatment, highlighting the influence of leukemia burden on systemic inflammation. The results support the utilization of EVs as a sensitive marker of oxidative stress and off-target tissue damage.

Obesity is a significant risk factor for cardiac arrhythmias, and the ferroptosis is closely related to cardiac arrhythmias. This study aimed to investigate whether puerarin (Pue), a natural isoflavone, could reduce the susceptibility to ventricular arrhythmias (VAs) associated with obesity and inhibit ferroptosis, with a particular focus on the Sirt1/Nrf2 signaling pathway. Male rats were randomly divided into three groups: normal chow diet (NC), high-fat diet (HFD), and HFD with Pue treatment (100mg/kg, HFD + Pue). After 16 weeks, electrophysiological, structural, and molecular analysis were performed. Compared to the NC group, HFD rats exhibited prolonged QT interval and Tpeak-Tend interval, amplified transmural dispersion of ventricular repolarization, and increased susceptibility to VAs. Pue treatment significantly ameliorated these electrophysiological abnormalities and reduced VAs susceptibility. HFD rats showed cardiac hypertrophy, fibrosis, and inflammation, which were alleviated by Pue application. Cardiac lipid peroxidation, iron deposition, mitochondrial abnormality, and ferroptosis marker induction were observed in HFD rats. Further, treatment with Pue improved these alterations. Additionally, molecular docking analysis confirmed the interaction of Pue with Sirt1 and Nrf2. Furthermore, Pue treatment upregulated Sirt1 and Nrf2 expression in HFD rats, thereby reducing reactive oxygen species (ROS) generation and ferroptosis. Moreover, Pue protected cardiomyocytes against palmitic acid (PA)-induced injury by inhibiting ferroptosis via the Sirt1/Nrf2 pathway in H9c2 cells. Overall, our study shows for the first time that Pue reduces susceptibility to VAs and inhibits ferroptosis in HFD rats by modulating the Sirt1/Nrf2 signaling pathway, offering a potential therapeutic strategy for obesity-related cardiac arrhythmias.

Flavan-3-ols are the most found flavonoid compounds in the human diet. Polymeric and monomeric flavan-3-ols reach the colonic region intact, where the gut microbiota utilizes them as substrates. In this research work, we investigated the pattern of colonic metabolites associated with flavan-3-ols, conducting a comprehensive analysis that combined (un)targeted metabolomics and in vitro colonic models. Firstly, the proposed flavan-3-ol metabolic pathway was investigated in-depth using a static in vitro model inoculated with different fecal donors. An apple, (-)-epicatechin, and procyanidin C1 were employed as feeding conditions. Small phenolic acids, such as phenylpropanoic acid and 3,4-dihydroxybenzoic acid, were positively associated with the apple feeding condition. In contrast, 5-(3',4'-dihydroxyphenyl)-γ-valerolactone and other specific early intermediates like phenylvaleric acids were positively associated with (-)-epicatechin. Secondly, by employing a dynamic in vitro simulator model of the human digestion system (SHIME), we reconstructed the flavan-3-ol metabolic pathway regionally. In the proximal colon region, we localized catabolites, such as 5-(3',4'-dihydroxyphenyl)-γ-valerolactone, while in the distal region, we identified mainly small phenolics. Combining static and dynamic in vitro models, we observed differences in the release of flavan-3-ol catabolites, influenced by both the food structure (isolated compounds and a food matrix) and the colonic region. This study sheds light on the colonic catabolism of one of the main dietary (poly)phenols and localizes microbial metabolites.

The interference of the expression of each of the genes involved in the synthesis of coenzyme Q (CoQ) in Drosophila melanogaster can help to understand the pathophysiology of CoQ-dependent mitochondrial diseases in humans. We have knocked-down all genes involved in the CoQ biosynthesis pathway at different temperatures to induce depletion of CoQ at different levels throughout the body and in a tissue-specific manner. The efficiency of the knockdowns was quantified by Q-RTPCR and determination of CoQ levels by HPLC-UV+ECD. We performed mitochondria purification and quantified respiratory chain activity, both mitochondrial hydrogen peroxide and superoxide production, resistance to mechanical stress and determination of life expectancy. Finally, we evaluated the effect of CoQ10 supplementation as phenotype rescue therapy. D. melanogaster presents 3 isoforms of CoQ: CoQ8, CoQ9 and CoQ10. The level of depletion depended on the efficiency of the RNAi used and is specific for each gene. The interference of some genes interrupted fly development in embryogenesis (pdss2) or during metamorphosis (pdss1, coq3, coq5, coq8 and coq10), while in other cases viable adults can be obtained (coq2, coq6 and coq7). The knockdown of coq7 accumulated intermediates of the CoQ biosynthesis pathway at all stages of development, altered electron transfer with poor assembly of mitochondrial complexes, and deregulated mitochondrial hydrogen peroxide and superoxide production. Coq7 mutant flies showed partial lethality in metamorphosis, bang sensitivity and reduced life span of surviving animals. CoQ10 supplementation rescued the coq7-mutant phenotypes. Knock-down in the imaginal disc generated gene-specific eye deformities that can be mitigated by CoQ10 supplementation. Our results indicate that interference of the CoQ biosynthesis pathway in D. melanogaster shows a great diversity of phenotypes depending on the target gene, mirroring the heterogeneity of CoQ deficiency syndrome in humans and point to why mutations in certain genes are rarely found in patients.

Hemorrhagic shock and reperfusion (HSR) is the main cause of death following trauma. Cognitive impairment may persist after successful resuscitation from hemorrhagic shock, but the mechanisms remain elusive. This study demonstrated the presence of ferroptosis in an in vitro model of oxygen-glucose deprivation and reoxygenation (OGD/R) in HT22 neurons, and also in a murine model of HSR using 3-month-old C57BL/6 mice. The ferroptosis induced by OGD/R was characterized by transmission electron microscopy, the localization of FTH1 and TFR1 in HT22 cells. However, neuronal ferroptosis was prevented by suppressing AMPK through siRNA transfection or AMPK inhibitor pretreatment (compound C) in vitro. There was a consistent increase in Nrf2 with ROS accumulation, iron deposition, and lipid peroxidation in the hippocampal neurons and tissues. Nrf2 knockdown or overexpression significantly modulated OGD/R induced-ferroptosis. Activating ferroptosis by erastin (a ferroptosis inducer) or inhibiting it by ferrostatin-1 (a ferroptosis inhibitor) respectively enhanced or mitigated cognitive deficits as well as the ferroptosis-related changes induced by HSR. In addition to the improved cognition, single-nucleus transcriptome analysis of ipsilateral hippocampi from Nrf2^-/- mice demonstrated the broad decrease of ferroptosis in neuronal cell clusters. LAMA2 and DAG1 were dominantly elevated and co-localized in the hippocampal CA3 region of Nrf2^-/- mice by fluorescence in situ hybridization. The activation of astrocytes was significantly attenuated after Nrf2 knockout, associated with the increases of laminin-dystroglycan during astrocyte-neuron crosstalk. Thus, data from this study proposes a novel explanation, namely laminin-dystroglycan interactions during astrocytes-neurons crosstalk stimulating AMPK and Nrf2 induced neuronal ferroptosis, for the development of cognitive impairment after HSR.

Plasma nitrate (NO₃^-) and nitrite (NO₂^-) increase in a dose-dependent manner following NO₃^- ingestion. To explore if the same dose-response relationship applies to other nitric oxide (NO) congeners in different blood compartments and skeletal muscle, as well as the subsequent physiological responses, we provided 11 healthy participants with NO₃^- depleted beetroot juice (placebo), and beetroot juice (BR) containing 6.4, 12.8 and 19.2 mmol NO₃^- in a randomised, crossover design. Blood and muscle samples were collected, and resting blood pressure (BP) was assessed, before and at 2.5-3 h post-ingestion. Muscle contractile function was assessed using a 5-min all-out maximal voluntary isometric knee extension test at 3.5 h post-ingestion. We found that plasma and skeletal muscle [NO₃^-], and whole blood S-nitrosothiols ([RSNOs]) increased dose-dependently, while plasma [NO₂^-] did not increase further with doses above 6.4 mmol NO₃^-. No significant increases in skeletal muscle [NO₂^-] were found following ingestion of any of these doses. Resting BP was only reduced after ingestion of 19.2 mmol NO₃^-. Mean peak torque and mean torque impulse during the first 10 muscle contractions were significantly enhanced following ingestion of both 12.8 mmol and 19.2 mmol NO₃^- compared to placebo, while the mean absolute rate of torque development (RTD) at 0-50 ms and 0-100 ms was significantly improved following ingestion of 6.4 mmol NO₃^- compared to placebo and 19.2 mmol NO₃^-. Significant correlations were found between changes in red blood cell [RSNOs] and changes in absolute RTD at 0-50 ms (r_s=-0.70, P=0.02) and 0-100 ms (r_s=-0.84, P<0.01) following the ingestion of 6.4 mmol NO₃^-. Our findings suggest that a high dose of 12.8 mmol NO₃^- is necessary to improve muscle contractile torque, while a lower dose of 6.4 mmol NO₃^- is sufficient to enhance muscle contractile velocity, at least for the type of exercise employed in the present study.

The multi-kinase inhibitor sorafenib has shown potential to inhibit tumor cell growth and intra-tumoral angiogenesis by targeting several kinases, including VEGFR2 and RAF. Abnormal activation of the Ras/Raf/MAPK/ERK kinase cascade and the VEGF pathway is a common feature in breast cancer. However, the efficacy of sorafenib in breast cancer treatment remains limited. Recently, fasting has emerged as a promising non-pharmacological approach to modulate cancer metabolism and enhance the effectiveness of cancer therapies. In this study, we found that fasting significantly enhances the anti-cancer effects of sorafenib monotherapy and its combination with immunotherapy in breast cancer models without causing obvious side effects. This combined treatment effectively inhibits tumor cell proliferation and intra-tumoral angiogenesis. The fasting-induced reduction in peripheral blood glucose levels strongly correlated with enhanced sensitivity to sorafenib. Mechanistically, the combined treatment induced mitophagy, characterized by mitochondrial dysfunction and activation of the PINK1-Parkin pathway. Consequently, increased mitochondrial ROS levels promoted p53 expression, amplifying cell cycle arrest and apoptosis in breast cancer cells. Furthermore, fasting reduced lactate levels within the tumor, and the consequent glucose limitation synergized with sorafenib to activate AMPK, which in turn elevated PD-L1 expression in tumor cells, potentially enhancing their sensitivity to immunotherapy. In summary, our findings demonstrate that fasting and sorafenib, as a rational combination therapy, induce mitophagy, thereby enhancing sorafenib's efficacy in treating breast cancer through the ROS-driven p53 pathway. This study underscores the potential of fasting in breast cancer therapy and provides a foundation for optimizing the clinical application of sorafenib.

Lung tissue from human patients and murine models of sickle cell disease pulmonary hypertension (SCD-PH) show perivascular regions with excessive iron accumulation. The iron accumulation arises from chronic hemolysis and extravasation of hemoglobin (Hb) into the lung adventitial spaces, where it is linked to nitric oxide depletion, oxidative stress, inflammation, and tissue hypoxia, which collectively drive SCD-PH. Here, we tested the hypothesis that intrapulmonary delivery of hemopexin (Hpx) to the deep lung is effective at scavenging heme-iron and attenuating the progression of SCD-PH. Herein, we evaluated in a murine model of hemolysis driven SCD-PH, if intrapulmonary Hpx administration bi-weekly for 10 weeks improves lung iron deposition, exercise tolerance, cardiovascular function, and multi-omic indices associated with SCD-PH. Data shows Hpx delivered with a micro-sprayer deposits Hpx in the alveolar regions. Hpx extravasates into the perivascular compartments but does not diffuse into the circulation. Histological examination shows Hpx therapy decreased lung iron deposition, 4-HNE, and HO-1 expression. This was associated with improved exercise tolerance, cardiopulmonary function, and multi-omic profile of whole lung and RV tissue. Our data provides proof of concept that treating lung heme-iron by direct administration of Hpx to the lung attenuates the progression of PH associated with SCD.

Cardiac metabolism relies on glycogen conversion by glycolysis. Glycolysis intersects fatty acid oxidation and often directs a signal crosstalk between redox metabolites. Myocardium with ischemia/reperfusion significantly diverts from normal metabolism. Prospectively, peroxisome lies central to metabolism and redox changes, but mechanisms underlying in ischemia/reperfusion remain undefined. This work aims at investigating the potential effects and mechanisms of Salvianolic acid B (Sal B) in cardioprotection through metabolic remodeling. Following experiments, we found that Sal B is absorbed in blood and rat hearts and its cardiac absorption prevents ischemia/reperfusion injury. Sal B cardioprotection relates to gluconeogenesis activation and peroxisomal redox remodeling. Gluconeogenesis compensates glycogen synthesis through upregulating pyruvate carboxylase (PC) and phosphoenolpyruvate carboxykinase. Gluconeogenic PC activity drives peroxisomal Pex2/Pex3 expressions and promotes the proliferation of peroxisome. Peroxisome quality control is enhanced with Pex5/Pex14/Pex13/Pex2 transcriptions. Nono, a non-POU domain-containing octamer-binding protein, promotes upregulation of gluconeogenic PC and peroxisomal gene transcripts through transcriptionally splicing their pre-RNAs at octamer duplex. Nono also controls the expression of SARM1/PARP1/sirtuin1 for catalyzing nicotinamide adenine dinucleotide (NAD⁺) consumption, leading to endurable redox capacities of peroxisome. Peroxisomal redox remodeling alters reactive oxygen species (ROS) and NAD⁺ contents, following which NAD⁺ affects cardiac accumulation of physiologically harmful glucocorticoid. In the tests of Sal B combinational treatments, results indicate ROS upregulation whereas NAD⁺ downregulation with glucocorticoid, ROS scavenging and glucocorticoid elimination with NAD⁺ precursor, and NAD⁺ promotion with ROS scavenger, respectively. This metabolite signal crosstalk alternatively antagonizes/agonizes Sal B cardioprotective functions on electrocardiographic output and infarction. Taken together, we reported a cardiac metabolism regulation with Sal B, capable of preventing myocardium from ischemia/reperfusion injury. The metabolite signal crosstalk was achieved by coupling reaction cascades between gluconeogenesis and peroxisomal redox remodeling.

Cuproptosis, a copper-dependent form of regulated cell death, has been implicated in the progression and treatment of various tumors. The copper ionophores, such as Disulfiram (DSF), an FDA-approved drug previously used to treat alcohol dependence, have been found to induce cuproptosis. However, the limited solubility and effectiveness of the combination of DSF and copper ion restrict its widespread application. In this study, through a random screening of our in-house compound library, we identified a novel cuproptosis inducer, YL21, comprising a naphthoquinone core substituted by two dithiocarbamate groups. The combination of YL21 with copper ion induces cuproptosis by disrupting mitochondrial function and promoting the oligomerization of lipoylated protein DLAT. Further, this combination induces endoplasmic reticulum (ER) stress and oxidative stress, triggering immunogenic cell death (ICD) and subsequently promoting the activation of antitumor immune responses to suppress tumor growth in the mice breast cancer model. Notably, the combination of YL21 and copper ion demonstrated improved solubility and increased antitumor activity compared to the combination of DSF and copper ion. Thus, YL21 functions as a novel cuproptosis inducer and may serve as a promising candidate for antitumor immunotherapy.