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Ventilator-induced lung injury (VILI) is the most common complication associated with mechanical ventilation. Electroacupuncture (EA) has shown potent anti-inflammatory effects. This study aimed to investigate the effects of EA on VILI and explore the underlying mechanisms. Male C57BL/6 mice were subjected to high tidal volume ventilation to induce VILI. Prior to mechanical ventilation, mice received treatment with EA, nonacupoint EA, or EA combined with zinc protoporphyrin. EA treatment significantly improved oxygenation, as indicated by increased PaO 2 levels in VILI mice. Moreover, EA reduced lung injury score, lung wet/dry weight ratio, and protein concentration in bronchoalveolar lavage fluid. EA also decreased the expression of pro-inflammatory cytokines including interleukin (IL)-1β, IL-6, tumor necrosis factor-α, IL-18, chemokine keratinocyte chemoattractant, macrophage inflammatory protein 2, and malondialdehyde. Furthermore, EA increased the activities of antioxidant enzymes superoxide dismutase, catalase, and glutathione peroxidase in VILI mice. At the molecular level, EA upregulated the expression of Nrf2 (nucleus) and heme oxygenase −1, while down-regulating the expression of p-NF-κB p65, NLR Family Pyrin Domain Containing 3, Cleaved Caspase-1, and ASC in VILI mice. Notably, the effects of EA were reversed by zinc protoporphyrin treatment, nonacupoint EA did not affect the aforementioned indicators of VILI. EA alleviates VILI by inhibiting the NLR Family Pyrin Domain Containing three inflammasome through activation of the Nrf2/HO-1 pathway. [ABSTRACT FROM AUTHOR]

Carbon monoxide (CO) has been recognized as a crucial gasotransmitter mainly produced by heme oxygenase (HO)-catalyzed heme degradation in plant. Recent studies have shown that CO plays an important role in regulating growth and development of plant, as well as and responding to a variety of abiotic stresses. Meanwhile, many studies have reported on CO working in combination with other signal molecules to mitigate abiotic stress. Here, we presented a comprehensive overview of recent developments in which CO reduces plant damage caused by abiotic stresses. The regulation of antioxidant system, photosynthetic system, ion balance and transport are the main mechanisms of CO-alleviated abiotic stress. We also proposed and discussed the relationship between CO and other signal molecules, including nitric oxide (NO), hydrogen sulfide (H 2 S), hydrogen gas (H 2), abscisic acid (ABA), indole 3-acetic acid (IAA), gibberellin (GA), cytokine (CTK), salicylic acid (SA), jasmonic acid (JA), hydrogen peroxide (H 2 O 2) and calcium ion (Ca2+). Furthermore, the important role of HO genes in alleviating abiotic stress was also discussed. We proposed promising and new research directions for the study of plant CO, which can provide further insights on the role of CO in plant growth and development under abiotic stress. • CO/HO system alleviates abiotic stress by regulating antioxidant and photosynthetic system and ion balance. • CO/HO system interacts with gas molecules, phytohormones and plant growth regulators to enhance stress tolerance. • HO genes have no tissue specificity and can be induced by various abiotic stresses. [ABSTRACT FROM AUTHOR]

The deubiquitinating enzyme USP14 has been established as a crucial regulator in various diseases, including tumors, neurodegenerative diseases, and metabolic diseases, through its ability to stabilize its substrate proteins. Our group has utilized proteomic techniques to identify new potential substrate proteins for USP14, however, the underlying signaling pathways regulated by USP14 remain largely unknown. Here, we demonstrate the key role of USP14 in both heme metabolism and tumor invasion by stabilizing the protein BACH1. The cellular oxidative stress response factor NRF2 regulates antioxidant protein expression through binding to the antioxidant response element (ARE). BACH1 can compete with NRF2 for ARE binding, leading to the inhibition of the expression of antioxidant genes, including HMOX-1. Activated NRF2 also inhibits the degradation of BACH1, promoting cancer cell invasion and metastasis. Our findings showed a positive correlation between USP14 expression and NRF2 expression in various cancer tissues from the TCGA database and normal tissues from the GTEx database. Furthermore, activated NRF2 was found to increase USP14 expression in ovarian cancer (OV) cells. The overexpression of USP14 was observed to inhibit HMOX1 expression, while USP14 knockdown had the opposite effect, suggesting a role for USP14 in regulating heme metabolism. The depletion of BACH1 or inhibition of heme oxygenase 1 (coded by HMOX-1) was also found to significantly impair USP14-dependent OV cell invasion. In conclusion, our results highlight the importance of the NRF2-USP14-BACH1 axis in regulating OV cell invasion and heme metabolism, providing evidence for its potential as a therapeutic target in related diseases. • USP14 binds directly to BACH1 protein in ovarian cancer cells. • USP14 regulates protein half-life and ubiquitination modifications of BACH1 in ovarian cancer cells. • Activated NRF2 promotes the expression of USP14, and USP14 can regulate heme metabolism. • USP14 regulates ovarian cancer cell invasion dependent on BACH1 protein. [ABSTRACT FROM AUTHOR]

Apocarotenoids have short carbon chain structures cleaved at a polyene-conjugated double bond. They can be biosynthesized in plants and microorganisms. Animals ingest carotenoids through food and then metabolize them into apocarotenoids. Although several apocarotenoids have been identified in the body, their precise health functions are still poorly understood. This study investigated the anti-inflammatory activities of apo-12′-capsorubinal in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. It was confirmed that apo-12′-capsorubinal was not cytotoxic to the macrophages at the concentrations tested. Apo-12′-capsorubinal treatment led to a marked downregulation of interleukin (IL)-6 protein and Il6 mRNA levels. This apocarotenoid exhibited more potent inhibitory effects than its parent carotenoids, capsanthin and capsorubin. Furthermore, apo-12′-capsorubinal, but not its parent carotenoids, promoted the nuclear accumulation of nuclear factor erythroid 2-related factor 2 (Nrf2) and upregulated the expression of Nrf2-target genes, such as heme oxygenase 1 (HO-1) and NAD(P)H:quinone oxidoreductase 1 (NQO-1), in a dose-dependent manner. Furthermore, a comparison using apo-12′-zeaxanthinal and 7,8-dihydro-8-oxo-apo-12′-zeaxanthinal revealed that the α, β-unsaturated carbonyl group on the polyene linear chain mediated the enhanced nuclear Nrf2 translocation, HO-1 expression, and inhibition of IL-6 production. In contrast, apo-12′-mytiloxanthinal, which harbored a hydroxyl group at C-8 of apo-12′-capsorubinal, did not exhibit any of these activities. These results indicated that the β carbon of the α, β-unsaturated carbonyl group in the linear part of the polyene chain is crucial to the Nrf2-activating and anti-inflammatory effects of apo-12′-capsorubinal. This study will advance our knowledge of the physiological significance of xanthophyll-derived apocarotenoids and their potential use as nutraceuticals and pharmaceuticals. [Display omitted] • Apo-12′-capsorubinal inhibited IL-6 production in activated macrophages. • Apo-12′-capsorubinal activated Nrf2 and upregulated its target genes expression. • Apo-12′-mytiloxanthinal neither inhibited IL-6 production nor activated Nrf2. • β Carbon of α,β-unsaturated carbonyl in apo-12′-capsorubinal is crucial to its action. [ABSTRACT FROM AUTHOR]

The goal of the study was to determine the ameliorative effects of dietary alpha-lipoic acid (α-LA) on deltamethrin (DEL)-induced immunosuppression and oxidative stress in northern snakehead (Channa argus). The northern snakeheads (15.38 ± 0.09 g) were exposed to DEL (0.242 μg/L) and fed with diets supplemented α-LA at 300, 600, and 900 mg/kg. After the 28-day exposure test, we obtained the following results: i) α-LA alleviates DEL-induced liver injury by reversing the increase of the serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels and liver cytochrome P450 enzymes (Cytochrome P450 (cyp) 1a and cyp1b) expression levels. ii) α-LA can reverse the DEL-induced reduction of serum complement 4 (C4), C3, immunoglobulin M (IgM), and lysozyme (LYS) levels and the increase of liver and intestine nuclear factor kappa B (nf-κb) p65 , tumor necrosis factor (tnf) -α , interleukin (il) -1β , il-8 , and il-6 gene expressions, while il-10 expression levels showed the opposite result. iii) α-LA reversed the reduction of superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), glutathione-S-transferase (GST) and glutathione peroxidase (GSH-Px) levels in the liver and intestine induced by DEL, while malondialdehyde (MDA) showed the opposite result. iv) α-LA reversed the reduction of Cu/Zn sod , nuclear factor erythroid 2-related factor 2 (nrf2), NAD (P)H: quinone oxidoreductase (nqo) 1 , and heme oxygenase (ho) -1 antioxidant gene expression levels in the liver and intestine induced by DEL. Therefore, our study indicated that optimal α-LA (600 mg/kg) could attenuate DEL-induced toxicity (including liver damage, immunotoxicity, and oxidative stress) in northern snakehead via Nrf2/NF-κB signaling pathway. This is the first research that explores the alleviated effects of α-LA on DEL-induced toxicity damage in fish. This study provides a positive measure to reduce the toxicity damage caused by DEL to aquatic animals, and provides a theoretical basis for exploring the regulation mechanism of α-LA in toxic substances. • α-lipoic acid alleviated DEL-induced liver injury of Channa argus. • α-lipoic acid alleviated DEL-induced oxidative stress of Channa argus by activating Nrf2 signaling pathway. • α-lipoic acid alleviated DEL-induced immunotoxicity of Channa argus by inhibiting NF-κB signaling pathway. [ABSTRACT FROM AUTHOR]

Chronic alcohol enhances oxidative stress, but the temporal response of antioxidant genes in skeletal muscle following a binge drinking episode remains unknown. Experiment 1: C57BL/6Hsd female mice received an IP injection of saline (CON; n = 39) or ethanol (ETOH; n = 39) (5 g/kg). Gastrocnemius muscles were collected from baseline (untreated; n = 3), CON (n = 3), and ETOH (n = 3) mice every 4 h for 48 h. Experiment 2: Gastrocnemius muscles were collected from control-fed (CON-FED; n = 17), control-fasted (CON-FAST; n = 18), or alcohol-fed (ETOH-FED; n = 18) mice every 4hrs for 20hrs after saline or ethanol (5 g/kg). EtOH enhanced Superoxide dismutase 1 (Sod1) and NADPH Oxidase 4 (Nox4) from 24 to 48hr after the binge, while Sod2 and Nox2 were suppressed. Nuclear factor erythroid-derived 2-like 2 (Nrf2) and Kelch-like ECH-associated protein 1 (Keap1) increased 12hrs after intoxication. Cytochrome P450 oxidoreductase (Por), Heme oxygenase 1 (Ho1), Peroxiredoxin 6 (Prdx6), Glutamate-cysteine ligase catalytic subunit (Gclc), Glutamate-cysteine ligase modifier subunit (Gclm), and Glutathione-disulfide reductase (Gsr) were increased by ETOH starting 12–16hrs post-binge. Fasting had similar effects on Nrf2 compared to alcohol, but downstream targets of NRF2, including Por, Ho1, Gclc, and Gclm, were differentially altered with fasting and EtOH. These data suggest that acute alcohol intoxication induced markers of oxidative stress and antioxidant signaling through the NRF2 pathway and that there were effects of alcohol independent of a possible decrease in food intake caused by binge intoxication. • Binge alcohol increased antioxidant gene expression in skeletal muscle. • Antioxidant gene changes after binge alcohol intoxication lasted for over 24 h. • Fasting causes some similar changes in antioxidant genes as binge alcohol. [ABSTRACT FROM AUTHOR]

Fine particulate matter (PM2.5) has been extensively implicated in the pathogenesis of neurodevelopmental disorders, but the underlying mechanism remains unclear. Recent studies have revealed that PM2.5 plays a role in regulating iron metabolism and redox homeostasis in the brain, which is closely associated with ferroptosis. In this study, the role and underlying mechanism of ferroptosis in PM2.5-induced neurotoxicity were investigated in mice, primary hippocampal neurons, and HT22 cells. Our findings demonstrated that exposure to PM2.5 could induce abnormal behaviors, neuroinflammation, and neuronal loss in the hippocampus of mice. These effects may be attributed to ferroptosis induced by PM2.5 exposure in hippocampal neurons. RNA-seq analysis revealed that the upregulation of iron metabolism-related protein Heme Oxygenase 1 (HO-1) and the activation of mitophagy might play key roles in PM2.5-induced ferroptosis in HT22 cells. Subsequent in vitro experiments showed that PM2.5 exposure significantly upregulated HO-1 in primary hippocampal neurons and HT22 cells. Moreover, PM2.5 exposure activated mitophagy in HT22 cells, leading to the loss of mitochondrial membrane potential, alterations in the expression of autophagy-related proteins LC3, P62, and mTOR, as well as an increase in mitophagy-related protein PINK1 and PARKIN. As a heme-degradation enzyme, the upregulation of HO-1 promotes the release of excess iron, genetically inhibiting the upregulation of HO-1 in HT22 cells could prevent both PM2.5-induced mitophagy and ferroptosis. Furthermore, pharmacological inhibition of mitophagy in HT22 cells reduced levels of ferrous ions and lipid peroxides, thereby preventing ferroptosis. Collectively, this study demonstrates that HO-1 mediates PM2.5-induced mitophagy-dependent ferroptosis in hippocampal neurons, and inhibiting mitophagy or ferroptosis may be a key therapeutic target to ameliorate neurotoxicity following PM2.5 exposure. • PM2.5 exposure induced ferroptosis in hippocampal neurons. • Transcriptome analysis revealed the iron metabolism imbalance and autophagy activation. • The activation of mitophagy contributed to the process of ferroptosis. • HO-1 was identified as the key molecule in regulation of mitophagy-dependent ferroptosis. [ABSTRACT FROM AUTHOR]

All drugs that can penetrate the blood-brain barrier (BBB) may lead to mental state changes, including the widely used anti-infective drug sulfamethoxazole (SMZ). Herein, we investigated whether lycopene (LYC) could ameliorate SMZ-induced brain injury and the postulated mechanisms involved. A total of 120 grass carps were exposed under SMZ (0.3 μg/L, waterborne) or LYC (10 mg/kg fish weight, diet) or their combination for 30 days. Firstly, brain injury induced by SMZ exposure was suggested by the damage of BBB (decreases of Claudins, Occludin and Zonula Occludens), and the decrease of neurotransmitter activity (AChE). Through inducing oxidative stress (elevations of malondialdehyde and 8-hydroxy-2 deoxyguanosine, inhibition of glutathione), SMZ increased the intra-nuclear level of NF-κB and its target genes (TNF-α and interleukins), creating an inflammatory microenvironment. As a positive feed-back mechanism, apoptosis begins with activation of pro-death proteins (Bax/Bcl-2) and activation of caspases (caspase-9 and caspase-3). Meanwhile, a compensatory upregulation of constitutive Nrf2 and its downstream antioxidative gene expression (NAD(P)H Quinone Dehydrogenase 1 and Heme oxygenase 1) and accelerated autophagy (increases of autophagy-related genes and p62 inhibition) were activated as a defense mechanism. Intriguingly, under SMZ stress, LYC co-administration decreased NF-κB/apoptosis cascades and restored Nrf2/autophagy levels. The neuroprotective roles of LYC make this natural compound a valuable agent for prevention SMZ stress in environment. This study suggests that LYC might be developed as a potential candidate for alleviating environmental SMZ stress in aquaculture. • Sulfamethoxazole exposure leads to oxidative stress, inflammation and apoptosis in the brain. • Lycopene supplementation ameliorates brain damage induced by Sulfamethoxazole. • Lycopene exerts neuroprotection by rebalance of NF-κB/Nrf2 pathway. [ABSTRACT FROM AUTHOR]

With the increasing demand for blood transfusions, the production of human hemoglobin (Hb) from sustainable sources is increasingly studied. Microbial production is an attractive option, as it may provide a cheap, safe, and reliable source of this protein. To increase the production of human hemoglobin by the yeast Saccharomyces cerevisiae , the degradation of Hb was reduced through several approaches. The deletion of the genes HMX1 (encoding heme oxygenase), VPS10 (encoding receptor for vacuolar proteases), PEP4 (encoding vacuolar proteinase A), ROX1 (encoding heme-dependent repressor of hypoxic genes) and the overexpression of the HEM3 (encoding porphobilinogen deaminase) and the AHSP (encoding human alpha-hemoglobin-stabilizing protein) genes — these changes reduced heme and Hb degradation and improved heme and Hb production. The reduced hemoglobin degradation was validated by a bilirubin biosensor. During glucose fermentation, the engineered strains produced 18% of intracellular Hb relative to the total yeast protein, which is the highest production of human hemoglobin reported in yeast. This increased hemoglobin production was accompanied with an increased oxygen consumption rate and an increased glycerol yield, which (we speculate) is the yeast's response to rebalance its NADH levels under conditions of oxygen limitation and increased protein-production. • The sequential hemoglobin production optimization increased yeast cell volume. • Reducing the degradation of heme and hemoglobin decreased bilirubin formation. • Reducing the degradation yielded 18% of intracellular protein as human hemoglobin. • Engineered strain is suitable for the secretion of the hemoglobin to the medium. [ABSTRACT FROM AUTHOR]

Bortezomib is a classical proteasome inhibitor and previous researches have reported its roles of anti-oxidation and anti-inflammatory functions in various diseases. However, the role of Bortezomib in myocardial ischemia reperfusion injury (MIRI) is unclear. Thus, our research seeks to reveal the protective effects of Bortezomib pretreatment in the mice model of MIRI. First, by the optimization of Bortezomib concentration and pretreatment timepoints, we found that 0.5 mg/kg Bortezomib pretreatment 2 h before MIRI significantly attenuated pathological damage and neutrophil infiltration. Then we found that pretreatment with Bortezomib obviously increased myocardial systolic function ((left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS)) and decreased infarct size, as well as serum Troponin T levels. Meanwhile, Bortezomib pretreatment also remarkably augmented oxidative stress related protein levels of Superoxide dismutase [Cu–Zn] (SOD1), Catalase (CAT) and Glutathione (GSH), while reactive oxygen species (ROS) contents and Malonaldehyde (MDA) protein level were significantly reduced. Mechanistically, Bortezomib pretreatment significantly promoted nuclear translocation of transcriptional factor nuclear factor erythroid 2-related factor 2(Nrf2) and Heme Oxygenase 1(HO-1) expression. Interestingly, co-treatment with ML-385, a new type and selective Nrf2 inhibitor, counteracted antioxidative effects induced by Bortezomib pretreatment. In conclusion, Bortezomib pretreatment mitigates MIRI by inhibiting oxidative damage which is regulated by Nrf2/HO-1 signaling pathway. • Low dose proteasome inhibitor Bortezomib alleviates MIRI in mice. • Low dose Bortezomib alleviates oxidative stress following MIRI. • The mechanisms of Bortezomib protection against MIRI involves activation of Nrf2/HO-1 anti-oxidative signaling pathway. [ABSTRACT FROM AUTHOR]

It is estimated that 10% of carbon throughout the cosmos is in the form of carbon monoxide (CO). Earth's earliest prebiotic atmosphere included the trinity of gasotransmitters CO, nitric oxide (NO), and hydrogen sulfide (H 2 S), for which all of life has co-evolved with. The history of CO can be loosely traced to mythological and prehistoric origins with rudimentary understanding emerging in the middle ages. Ancient literature is focused on CO's deadly toxicity which is understandable in the context of our primitive relationship with coal and fire. Scientific inquiry into CO appears to have emerged throughout the 1700s followed by chemical and toxicological profiling throughout the 1800s. Despite CO's ghastly reputation, several of the 18th and 19th century scientists suggested a therapeutic application of CO. Since 2000, the fundamental understanding of CO as a deadly nuisance has undergone a paradigm shift such that CO is now recognized as a neurotransmitter and viable pharmaceutical candidate. This review is intended to provide a brief history on the trace origins pertaining to endogenous formation and therapeutic application of CO. [ABSTRACT FROM AUTHOR]

The red blood cells (RBCs) of fish make up around 95% of the total peripheral blood cells, and the long-held paradigm is that RBCs are mainly responsible for transporting oxygen. Previous studies have showed that the RBCs can be involved in the immune response against bacterial infection; however, this mechanism remains enigmatic. Here, we explored the structure of grass carp RBCs (Gc RBCs). The results showed that the Gc RBCs released a pseudopodia-like structure when grown in a 24-well plate, and the transmission electron microscopy (TEM) result showed that Gc RBCs contained some organelle-like structures. To further verify the organelle-like structures might be the mitochondria and lysosome which similar to other immune cells, a fluorescent labeling assay was used to verify it. To decipher the antibacterial immunity of GcRBCs, transcriptomic profiling of grass carp RBCs after the incubation with E. coli was analyzed. The results showed that there were 4099 differently expressed genes (DEGs) of GcRBCs upon E. coli incubation, including 2041 up-regulated and 2058 down-regulated genes. In addition, to validate our transcriptomic data, we checked the expression of several cytokines, such as CCL4, CCL20, IL4, IL12 and IFN-α, and the results showed that all the selected gens were significantly up-regulated after E. coli incubation. Furthermore, E. coli incubation induced hemoglobin oxidation and increased the heme in GcRBCs, which further activated the expression of heme oxygenase 1 (HO-1), autophagy related genes 5 (ATG5), and ferritin. In contrast, E. coli incubation inhibited the expression of Ferroportin-1 (FPN1), which increased intracellular iron levels, induced Fenton reaction to release reactive oxygen species (ROS), and activated the ferroptosis signaling pathway in GcRBCs. Herein, we demonstrate that E. coli can induce teleost RBCs cell death through an iron-mediated ferroptosis pathway, which sheds new light on the interaction between bacteria and teleost RBCs. • E. coli incubation induced 4099 DEGs in grass carp RBCs. • The mRNA expression of some cytokines were significantly increased after E. coli incubation. • E. coli can induce teleost RBCs cell death through an iron-mediated ferroptosis pathway. [ABSTRACT FROM AUTHOR]

Heme oxygenase (HO)-1, a rate-limiting enzyme in heme catabolism, results in the formation of equivalent amounts of biliverdin (BV), carbon monoxide (CO) and ferrous iron (Fe2+). Previous studies have revealed that HO-1 plays an important role in immune responses. However, the mechanism underlying the immune responses against bacterial infection of teleost HO-1 remains enigmatic. To decipher the mechanisms, we have cloned and characterized the HO-1 gene of grass carp (designated as GcHO-1) in this research. The results showed that the open reading frame (ORF) of GcHO-1 was 819 bp, which encoded a putative protein of 272 amino acids. The deduced amino acid sequence phylogenetically shared the highest identity with other teleosts, and contained two domains of heme-oxygenase and a single-pass transmembrane domain. The mRNA expressions of GcHO-1 in healthy grass carp have widely existed in examined tissues in the following order of spleen > head-kidney > middle head-kidney > intestines > liver > gills > heart > muscle > brain. Besides, the mRNA and protein transcription of GcHO-1 were both significantly up-regulated in the liver and head-kidney tissues after Staphylococcus aureus and Aeromonas hydrophila infection. In addition, overexpression of GcHO-1 in kidney cell line (CIK) cells of grass carp could reduce the expression of inflammatory cytokines (IL-1β, IL-8, TNFα, CCL1 and IL-6). Herein, we demonstrate that GcHO-1 plays an anti-inflammatory role in innate immunity. Our results shed new light on the mechanisms underlying the antibacterial immunity of teleost. • HO-1 cDNA was isolated and successfully cloned from grass carp (GcHO-1). • GcHO-1 was expressed in all the tissues examined in healthy grass carp. • The transcripts and protein levels of GcHO-1 were significantly up-regulated after bacterial infection. • In CIK cells, GcHO-1 overexpression reduced the inflammatory cytokines levels. • The GcHO-1 could participate in antibacterial immunity of grass carp afterbacterial infection. [ABSTRACT FROM AUTHOR]

Doxorubicin (DOX) is a widely used cancer chemotherapeutic drug with cardiotoxicity effect limiting its clinical use. DOX induced cardiotoxicity is mediated by oxidative stress and mitochondrial damage. Kininogen-1(KNG1) is an important pro-inflammatory and pro-oxidant factor, and studies have found that it can aggravate lung and brain damage. However, it has not been known in terms of cardiotoxicity. Therefore, the purpose of this study is to understand the mechanism of KNG1 in DOX-induced heart injury. C57 mice were selected for intraperitoneal injection of DOX. The model was successfully established, and fresh ventricular tissues were isolated from the ctrl group and the DOX group for mass spectrometry analysis to screen for differentially expressed proteins. Nuclear Factor-Like 2 (Nrf2), Heme Oxygenase 1 (HO-1), 4-Hydroxynonenal (4-HNE) were used to evaluate oxidative stress level, Cytochrome C Oxidase Subunit 4 (COX4) was used to evaluate mitochondria function. Mitochondrial inner membrane potential (ΔΨm) was monitored with JC-1 fluorescence. KNG1 was identified as a core gene which was highly expressed in the DOX myocardial injury model. Following this, an overexpression adenovirus was constructed, and KNG1 was overexpressed in vivo (mice) and in vitro (neonatal mouse cardiomyocytes (NMCMs)). It was found that overexpression of KNG1 can aggravate heart oxidative stress and mitochondrial damage. Besides, a knockdown KNG1 model was constructed, and the low expression of KNG1 was performed in cytology. It was found that knockdown of KNG1 can improve cardiomyocyte oxidative stress and mitochondrial damage caused by DOX. Nrf2 is an important antioxidant factor. Further, following KNG1 knock down, Nrf2 was also knocked down, and found that its cardiomyocyte protective effect was weakened. The overexpression of KNG1 aggravates the oxidative stress and mitochondrial damage of the heart in vivo and in vitro, which might play a role by regulating Nrf2, providing a therapeutic target for DOX-induced cardiotoxicity. • Overexpression of KNG1 aggravates heart oxidative stress and mitochondrial damage in mice and NMCMs. • Knockdown of KNG1 improves NMCMs oxidative stress and mitochondrial damage caused by DOX. • Nrf2 is the downstream gene of KNG1. [ABSTRACT FROM AUTHOR]

A 75-day rearing trail was designed to evaluate the immunoreaction and antioxidant capacity of juvenile blunt snout bream in response to dietary methionine levels. Three practical diets were extruded to feed juveniles with graded methionine levels (0.40%, 0.84% and 1.28% dry matter). The data indicated that the plasma concentrations of immunoglobulin M (IgM), complement component 3 (C3) and glutathione (GSH) in the 0.84% methionine diet were markedly upper than those in the 0.40% group (P < 0.05). The activities of plasma antioxidant parameters involving catalase (CAT), total superoxide dismutase (T-SOD), total antioxidant capacity (T-AOC) and glutathione peroxidase (GPx) were significantly increased by the 0.84% diet compared with the 0.40% diet, whereas plasma alanine aminotransferase (ALT) and malondialdehyde (MDA) levels were significantly induced by 0.40% methionine (P < 0.05). Compared with the 0.40% group, 0.84% dietary methionine dramatically upregulated the mRNA expression levels of protein kinase B (Akt), phosphoinositide 3-kinase (PI3K) and nuclear factor erythroid 2-related factor 2 (Nrf2) pathway related genes including CAT, manganese superoxide dismutase (Mn-SOD), heme oxygenase 1 (HO-1) and glutathione peroxidase-1 (GPx-1) in the kidney and liver, and downregulated Kelch-like ECH-associated protein 1 (Keap1) mRNA levels (P < 0.05). Compared with the 0.40% group, the 0.84% dietary methionine strikingly suppressed the mRNA levels of renal and hepatic nuclear factor-kappa B (NF-κB) and pro-inflammatory cytokines (interleukin 1β (IL-1β), tumor necrosis factor-α (TNF-α), interleukin 6 (IL-6)), however, improved the mRNA expression levels of anti-inflammatory cytokines involved renal and hepatic transforming growth factor-β (TGF-β) and hepatic interleukin 10 (IL-10) (P < 0.05). Renal IL-10 and interleukin 8 (IL-8) mRNA expression levels were not markedly influenced by experimental diets (P > 0.05). Dietary methionine (0.84%) significantly upregulated renal and hepatic heat stress protein 70 (Hsp70), renal B-cell lymphoma-2 (Bcl-2) gene expression levels compared with the 0.40% diet (P < 0.05). In a word, the data represented that 0.84% dietary methionine could enhance the immune and antioxidant capacity of this fish species by inducing PI3K/Akt/Nrf2 pathway and inhibiting NF-κB pathway. • 0.84% dietary methionine improved antioxidant and immune related parameters. • Dietary methionine modulated Nrf2 signaling via PI3K/Akt pathway. • Dietary methionine regulated NF-κB signaling through PI3K/Akt pathway. [ABSTRACT FROM AUTHOR]

Epididymal epithelium possesses active ion transport properties conducive to the maintenance of appropriate epididymal intraluminal microenvironment. The endogenous gasotransmitter carbon monoxide (CO) regulates numerous cellular processes including water and electrolyte transport in various epithelia. However, the functional role of CO in epididymal epithelium is still elusive. This study aims to explore the potential regulatory effect of CO on transepithelial ion transport in rat epididymis. Using qPCR technique, we verified that endogenous CO synthase heme oxygenase 1 was expressed in rat caput, corpus, and cauda epididymis. In addition, endogenous CO was detected in rat cauda epididymis. Ussing chamber experiments showed that CORM-2, a CO donor, induced an increase of the short-circuit current (I SC) in a concentration-dependent manner in rat cauda epididymal epithelium. The I SC response could be abrogated by removing the ambient Cl− or HCO 3 −. Interfering with the cAMP signaling pathway or blocking cystic fibrosis transmembrane regulator (CFTR) partially suppressed the CO-stimulated I SC response. Moreover, the CO-evoked I SC response was significantly attenuated by blocking Ca2+-activated Cl− channel (CaCC) or chelating intracellular Ca2+. Elevation of intracellular Ca2+ level was also observed after CO stimulation in rat cauda epididymal epithelial cells. Collectively, this study demonstrated that CO stimulated anion secretion via activation of CFTR and CaCC in rat cauda epididymal epithelium, which might contribute to the formation of the appropriate microenvironment essential for sperm storage. • The endogenous CO synthase heme oxygenase 1 was expressed in rat epididymis. • The endogenous CO was produced in rat cauda epididymis. • CO facilitated transepithelial anion secretion in rat cauda epididymal epithelium via activation of CFTR and CaCC. • CO increased [Ca2+ i of rat cauda epididymal epithelial cells via PLC/IP 3 pathways. [ABSTRACT FROM AUTHOR]

The HMOX1 gene plays role in several biological processes and is also responsive to hypoxia stress. Freshwater carp fish, Labeo rohita , is reported as hypoxia sensitive, but the information of annotated hypoxia genes in public domain is very scanty for this species. Here, an attempt was made to isolate and characterize HMOX1 gene in L. rohita using information from zebrafish. HMOX1 gene was obtained by mapping HMOX1 protein of zebrafish over assembled genome of L. rohita. Aligned region was used for designing primers for HMOX1 amplification. Eight overlapping sets of primers were designed for amplifying ~540 bp long successive overlapping fragments. Splicing of overlapping amplicons generated 3715 bp fragment that was confirmed as HMOX1 gene having full coding region with 6 exons between 184 and 2156 bp positions. HMOX1 characterization is an initiative for L. rohita genes annotation to support the characterization of new genes in the important species. • HMOX1 gene plays important role in several biological processes, including hypoxia. • Characterized gene in hypoxia sensitive freshwater fish, Labeo rohita. • Assembly of overlapping amplicons generated 3715 bp fragment. • Gene comprised a full coding region with 6 exons between 184 to 2156 bp positions. • HMOX1 annotation in L. rohita with negative strand orientation revealed resemblance to zebrafish HMOX1 gene in orientation. [ABSTRACT FROM AUTHOR]

Hepatocyte-derived inducible nitric oxide synthase (iNOS) was proved to impart protection against liver ischemia reperfusion (I/R) injury in our prior analysis. However, the mechanism for this hepatoprotection remains incompletely understood. Bone marrow chimeric mice were generated using expression of iNOS in a hepatocyte-selective manner against an iNOS-knockout background. The function of heme oxygenase 1 (HO-1) in iNOS-stimulated hepatoprotection and the molecular mechanisms were explored in vitro and in vivo, respectively. Hepatocyte-derived iNOS conferred protection from I/R injury and anoxia/reoxygenation stimulation. Mechanistically, iNOS activated nuclear factor erythroid 2-related factor 2 (Nrf-2) and subsequently, stimulated the transcription of HO-1. Results from our study led to the conclusion that HO-1 is another potent mediator of iNOS-mediated protection after liver I/R. • The exact role of endogenous iNOS remains controversial in liver I/R injury. • Hepatocellular iNOS is protective during I/R injury. • iNOS modulated hepatocellular HO-1 expression through Nrf2. [ABSTRACT FROM AUTHOR]

A feeding experiment was conducted to determine the effects of Schizochytrium sp. on growth performance, antioxidant capacity and non-specific immunity in golden pompano (Trachinotus ovatus).Two diets were formulated with or without Schizochytrium sp. supplemented (D1:0% and D2: 3%) to feed fish for 8 weeks. Results showed that growth performance, feed intake and survival rate increased significantly with Schizochytrium sp. supplemented (P < 0.05). Feed coefficient rate (FCR) of golden pompano fed the diet supplemented with Schizochytrium sp. was significantly lower than that of fish fed the control diet (P < 0.05). No significant differences were found in antioxidant capacity both in transcriptional level, including nclear factor erythroid-2-related factor-2 (Nrf2), Kelch-like-ECH-associated protein (keap1), catalase (CAT), glutathione peroxidase (GSH-PX) and heme oxygenase 1 (HO-1) and enzyme activity, such as total antioxidant capacity (T-AOC), malondialdehyde (MDA) and superoxide dismutase (SOD) (P > 0.05). Gut amylase and lipase were significantly higher in dietary Schizochytrium sp. supplemented treatment than that in control group (P < 0.05). The relative peroxisome proliferator-activated receptor-α (PPARα) expression level in liver was significantly higher in Schizochytrium sp supplemented treatment than that in control one (P < 0.05). The mRNA expression of myeloid differentiation factor 88 (MyD88), IL-1R-associated kinases 4 (IRAK4), interferon regulating Factor 3 (IRF3), interferon regulating Factor 3(IRF7) and heat shock protein 70 (HSP70) were significantly lower in Schizochytrium sp. supplemented treatment than that in control one (P < 0.05). In Schizochytrium sp. supplemented diet, golden pompano had significantly longer villi length than that in control diet (P < 0.05); muscle thickness in Schizochytrium sp. supplemented diet was thicker than that in control one (P < 0.05) and there were more goblet cells in Schizochytrium sp. treatment (P < 0.05). After the rearing trial, an air exposure trial was conducted. Results showed that the air-exposure mortality (AEM) and mRNA expression level of Nrf2, keap1, CAT, GSH-PX and HO-1 showed no significant difference (P > 0.05). These results indicated that dietary Schizochytrium sp. improved the growth performance and non-specific immunity of golden pompano while made no difference to antioxidant capacity. • Dietary Schizochytrium sp. improved the growth performance of T. ovatus by enhancing feed intake and feed conversion rate. • Schizochytrium sp. improved non-specific immunity by toll like receptor signal pathway. • Schizochytrium sp. made no significant difference to T. ovatus via Nrf2-ARE signal pathway. [ABSTRACT FROM AUTHOR]

The possible implication of the gasotransmitters NO and CO for the development of diabetes remains unresolved. Our previous investigations in rodents suggested NO being inhibitory, and CO stimulatory, to glucose-stimulated insulin secretion (GSIS). Here we studied the possible role of these gasotransmitters in both murine and human type 2 diabetes (T2D) by mapping the expression pattern of neural nitric oxide synthase (nNOS), inducible NOS (iNOS), constitutive heme oxygenase (HO-2), and inducible HO (HO-1) in isolated pancreatic islets. Two variants of obese murine diabetes with distinct phenotype, the db/db and the ob/ob mouse, were studied at the initiation of the diabetic condition. Plasma glucose and plasma insulin were recorded and β-cell expression levels of the different enzymes were measured with confocal microscopy and fluorescence intensity recordings. In human islets taken from nondiabetic controls (ND) and type 2 diabetes (T2D) the expression of the enzymes was analyzed by RNA-sequencing and qPCR. At the initiation of murine diabetes plasma glucose was slightly increased, whereas plasma insulin was extremely enhanced in both db/db and ob/ob mice. The β-cell expression of nNOS and iNOS was markedly increased over controls in db/db mice, known to develop severe diabetes, while it was very low in ob/ob mice, known to develop mild diabetes. HO-2 expression was unaffected in db/db and modestly decreased in ob/ob mice. HO-1 expression was slightly enhanced in ob/ob , but, in contrast, extremely enhanced in db/db mice, suggesting a counteracting, antidiabetic action by CO. Moreover, the diabetic pattern of highly increased nNOS, iNOS and HO-1 expression seen in db/db mice was also fully recognized in human T2D islets. These results suggest that increased expression of the NOS-enzymes, especially an early upregulation of nNOS, could be involved in the initial development of the severe diabetes of db/db mice as well as in human T2D. Hence, nNOS, iNOS and HO-1 might be regarded as interesting targets to take into consideration in the early treatment of a diabetic condition in different variants of T2D. • Young ob/ob mice with mild diabetes show low β-cell expression of nNOS, iNOS, HO-1. • Young db/db mice with severe diabetes show high β-cell expression of nNOS, iNOS, HO-1. • Similar to db/db mice human T2D show high islet expression of nNOS, iNOS, HO-1. [ABSTRACT FROM AUTHOR]

Thoracic aortic aneurysm (TAA) is a silent but life-threatening cardiovascular disease. Heme oxygenase 1 (HO-1) plays an important role in the cardiovascular diseases but is poorly understood in TAA. This study aims at investigating the role of HO-1 in TAA. Single-cell RNA sequencing, Western blot and histological assay were performed to identify specific cellular expression of HO-1 in both human and β-aminopropionitrile (BAPN)-induced mice TAA. Zinc protoporphyrin (ZnPP), a pharmacological inhibitor of HO-1, was used to investigate whether inhibition of HO-1 could attenuate BAPN-induced TAA in rodent model. Histological assay, Western blot assay, and mRNA sequencing were further performed to explore the underlying mechanisms. Single-cell transcriptomic analyses of 113,800 thoracic aortic cells identified an increase of HO-1(+) macrophage in aneurysmal thoracic aorta from BAPN-induced TAA mice and TAA patients. Histological assay verified HO-1 overexpression in clinical TAA specimens, which was co-localized with CD68(+) macrophage. HO-1(+) macrophage was closely associated with pro-inflammatory response and immune activation. Inhibition of HO-1 through ZnPP significantly alleviated BAPN-induced TAA in mice and restored extracellular matrix (ECM) in vivo. Further experiments showed that ZnPP treatment suppressed the expression of matrix metalloproteinases (MMPs) in aneurysmal thoracic aortic tissues from BAPN-induced TAA mice, including MMP2 and MMP9. Macrophages from myeloid specific HO-1 knockout mice displayed weakened pro-inflammatory activity and ECM degradation capability. HO-1(+) macrophage subgroup is a typical hallmark of TAA. Inhibition of HO-1 through ZnPP alleviates BAPN-induced TAA in mice, which might work through restoration of ECM via suppressing MMP2 and MMP9 expression. • HO-1(+) macrophage subgroup is increased in TAA, which is closely associated with pro-inflammatory response and immune activation. • Pharmacological inhibition of HO-1 through ZnPP significantly alleviates BAPN induced TAA in mice. • Inhibition of HO-1 restores ECM in thoracic aortic tissues of BAPN mice through suppressing MMP2 and MMP9 expression. [ABSTRACT FROM AUTHOR]

Zika virus (ZIKV), has gained global attention due to its association with severe disorders, including microcephaly and congenital Zika syndrome. We investigated the role of ZIKV nonstructural protein 1 (NS1) in altering the host's antioxidant response. Using a stable cell line expressing NS1, we found that NS1 significantly reduced the expression of antioxidant-related genes, including heme oxygenase 1 (HO-1), NAD(P)H quinone dehydrogenase 1 (NQO1), and sequestosome-1 (SQSTM1), which are regulated NRF2. Interestingly, this effect was attributed to increased expression of BACH1, a factor that competes with NRF2 for binding to certain antioxidant responsive elements (ARE). Thus, ZIKV NS1-mediated disruption of the antioxidant system is linked to BACH1 overexpression. These findings offer insights into ZIKV pathogenesis and suggest potential therapeutic strategies targeting the NRF2-BACH1 axis. • Zika Virus NS1 is responsible of NRF2 targets subversion. • The effect on NRF2 targets is related to NS1 intracellular pool. • Overexpression of NS1 is linked to BACH1 higher expression. • BACH1 increase is associated to repression of specific NRF2 targets. [ABSTRACT FROM AUTHOR]

The white shrimp Penaeus vannamei during its life cycle is commonly exposed to environmental stressors including hypoxia and reoxygenation that can affect their growth and survival. Hypoxia inducible Factor-1 (HIF-1) is a very important transcription factor involved in the responses to hypoxia and participates in other processes, including ferroptosis. Glutathione peroxidase 4 (GPx4) is a key ferroptosis component. In mammals, GPx4 has important biological functions beyond its antioxidant role. We studied the changes of HIF-1α and the ferroptosis process components, heme oxygenase −1 (HO-1), acyl-CoA synthetase long chain family member 4 (ACSL4), and catalase (CAT) in GPx4 knock-down shrimp exposed to hypoxia and reoxygenation. Malondialdehyde (MDA) content and CAT activity were also evaluated. Changes in HIF-1α, CAT, ACSL4, and HO-1 expression occurred 6 and 12 h after hypoxia and reoxygenation in shrimp hepatopancreas. HIF-1α and CAT expression were reduced during hypoxia and reestablished in reoxygenation at 6 and 12 h, while HO-1 did not change at 6 h, but increased during hypoxia at 12 h. Also, ACSL4 expression decreased during hypoxia and reoxygenation at 12 h, while MDA content was not affected by hypoxia and reoxygenation. GPx4 knock-down increased ACSL4 expression, MDA content, and CAT activity indicating that the ferroptosis process is induced by the intrinsic pathway in hepatopancreas during GPx4 knock-down. [Display omitted] • GPx4 knock down induced ferroptosis in shrimp hepatopancreas. • GPx4 knock-down increased ACSL4 expression and MDA content. • CAT activity increase in hepatopancreas in response to GPx4 knock-down. [ABSTRACT FROM AUTHOR]

Radix Bupleuri extract (RBE) is one of the most popular oriental herbal medicines, which has anti-oxidative and anti-inflammatory properties. However, its protective effects and underlying molecular mechanisms on oxidative damage in tilapia are still unclear. The aims of the study were to explore the anti-oxidative, anti-inflammatory and hepatoprotective effects of RBE against oxidative damage, and to elucidate underlying molecular mechanisms in fish. Tilapia received diet containing three doses of RBE (0, 1 and 3 g/kg diet) for 60 days, and then were given an intraperitoneal injection of H 2 O 2 or saline. Before injection, RBE treatments improved growth performance and partial anti-oxidative capacity in tilapia. After oxidative damage, RBE pretreatments were able to signally reduce the higher serum aminotransferases, alkaline phosphatase (AKP) and liver necrosis. In serum and liver, the abnormal lipid peroxidation level and antioxidant status induced by H 2 O 2 injection were restored by RBE treatments. Furthermore, RBE treatments activated erythroid 2-related factor 2 (Nrf2) signaling pathway, which promoted the gene expression of heme oxygenase 1 (HO-1), NAD(P) H:quinone oxidoreductase 1 (NQO-1), glutathione-S-transferase (GST) and catalase (CAT). Meanwhile, RBE treatments reduced inflammatory response by inhibiting TLRs-MyD88-NF-κB signaling pathway, accompanied by the lower interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α) and IL-8 mRNA levels. In addition, RBE treatments upregulated complement (C3) gene expression and downregulated heat shock protein (HSP70) gene expression. In conclusion, the current study suggested that RBE pretreatments protected against H 2 O 2 -induced oxidative damage in tilapia. The beneficial activity of RBE may be due to the modulation of Nrf2/ARE and TLRs-Myd88-NF-κB signaling pathway. • RBE exerts anti-oxidative, anti-inflammatory and hepatoprotective effects against liver injury in fish. • RBE activities Nrf2 signaling pathway to improve antioxidant defense. • RBE inhibits TLRs-MyD88-NF-κB signaling pathway to ameliorate inflammatory response. [ABSTRACT FROM AUTHOR]

Heme oxygenase-1 (HO-1, HMOX1) degrades pro-oxidant heme into carbon monoxide (CO), ferrous ions (Fe2+) and biliverdin. The enzyme exerts multiple cytoprotective functions associated with the promotion of angiogenesis and counteraction of the detrimental effects of cellular stress which are crucial for the survival of both normal and tumor cells. Accordingly, in many tumor types, high expression of HO-1 correlates with poor prognosis and resistance to treatment, i.e. chemotherapy, suggesting inhibition of HO-1 as a possible antitumor approach. At the same time, the lack of selective and well-profiled inhibitors of HO-1 determines the unmet need for new modulators of this enzyme, with the potential to be used in either adjuvant therapy or as the stand-alone targeted therapeutics. In the current study, we provided novel inhibitors of HO-1 and validated the effect of pharmacological inhibition of HO activity by the imidazole-based inhibitor (SLV-11199) in human pancreatic (PANC-1) and prostate (DU-145) cancer cell lines. We demonstrated potent inhibition of HO activity in vitro and showed associated anticancer effectiveness of SLV-11199. Treatment with the tested compound led to decreased cancer cell viability and clonogenic potential. It has also sensitized the cancer cells to chemotherapy. In PANC-1 cells, diminished HO activity resulted in down-regulation of pro-angiogenic factors like IL-8. Mechanistic investigations revealed that the treatment with SLV-11199 decreased cell migration and inhibited MMP-1 and MMP-9 expression. Moreover, it affected mesenchymal phenotype by regulating key modulators of the epithelial to mesenchymal transition (EMT) signalling axis. Finally, F-actin cytoskeleton and focal contacts were destabilized by the reported compound. Overall, the current study suggests a possible relevance of the tested novel inhibitor of HO activity as a potential anticancer compound. To support such utility, further investigation is still needed, especially in in vivo conditions. • New small-molecules targeting the active site of HO-1 were designed and synthesized. • SLV-11199 is a potent inhibitor of HO activity. • Inhibition of HO activity can have anti-tumor effects. [ABSTRACT FROM AUTHOR]

Nitric oxide synthase (NOS) catalyzes the transformation of l -arginine, molecular oxygen (O 2), and NADPH-derived electrons to nitric oxide (NO) and l -citrulline. Under some conditions, however, NOS catalyzes the reduction of O 2 to superoxide (O 2 −) instead, a phenomenon that is generally referred to as uncoupling. In principle, both the heme in the oxygenase domain and the flavins in the reductase domain could catalyze O 2 − formation. In the former case the oxyferrous (Fe(II)O 2) complex that is formed as an intermediate during catalysis would dissociate to heme and O 2 −; in the latter case the reduced flavins would reduce O 2 to O 2 −. The NOS cofactor tetrahydrobiopterin (BH4) is indispensable for coupled catalysis. In the case of uncoupling at the heme this is explained by the essential role of BH4 as an electron donor to the oxyferrous complex; in the case of uncoupling at the flavins it is assumed that the absence of BH4 results in NOS monomerization, with the monomers incapable to sustain NO synthesis but still able to support uncoupled catalysis. In spite of little supporting evidence, uncoupling at the reductase after NOS monomerization appears to be the predominant hypothesis at present. To set the record straight we extended prior studies by determining under which conditions uncoupling of the neuronal and endothelial isoforms (nNOS and eNOS) occurred and if a correlation exists between uncoupling and the monomer/dimer equilibrium. We determined the rates of coupled/uncoupled catalysis by measuring NADPH oxidation spectrophotometrically at 340 nm and citrulline synthesis as the formation of [3H]-citrulline from [3H]-Arg. The monomer/dimer equilibrium was determined by FPLC and, for comparison, by low-temperature polyacrylamide gel electrophoresis. Uncoupling occurred in the absence of Arg and/or BH4, but not in the absence of Ca2+ or calmodulin (CaM). Since omission of Ca2+/CaM will completely block heme reduction while still allowing substantial FMN reduction, this argues against uncoupling by the reductase domain. In the presence of heme-directed NOS inhibitors uncoupling occurred to the extent that these compound allowed heme reduction, again arguing in favor of uncoupling at the heme. The monomer/dimer equilibrium showed no correlation with uncoupling. We conclude that uncoupling by BH4 deficiency takes place exclusively at the heme, with virtually no contribution from the flavins and no role for NOS monomerization. Image 1 • NOS uncoupling in the absence of BH4 takes place exclusively at the heme. • NOS monomerization is irrelevant for uncoupling. • The NOS flavins play no part in uncoupling caused by Arg and BH4 deficiency. [ABSTRACT FROM AUTHOR]

Intracerebral hemorrhage (ICH) is a devastating stroke subtype and the presence of extracorpuscular hemoglobin (Hb) exacerbates brain damage. Haptoglobin (Hp) binds Hb, which prevents its oxidation and participation in neurotoxic reactions. Multiple studies have investigated the role of Hp under conditions of intravascular hemolysis, but little is known about its role in the brain and following ICH where extravascular hemolysis is rampant. Young and aged wildtype and Hp−/− mice underwent the autologous blood or collagenase ICH model. Early after ICH, Hp−/− mice display 58.0 ± 5.6% and 36.7 ± 6.9% less brain damage in the autologous blood and collagenase ICH models, respectively. In line with these findings, Hp−/− mice display less neurological deficits on several neurobehavioral tests. Hp−/− mice have less Perl's iron content, HO1 expression, and blood brain barrier dysfunction, but no difference in brain Hb content, astrogliosis and angiogenesis/neovascularization. At the later endpoint, the young cohort displays 27.8 ± 9.3% less brain damage, while no difference is seen with the aged cohort. For both cohorts, no differences are seen in HO1 levels or iron accumulation, but young Hp−/− mice display less thalamic astrogliosis and striatal microgliosis. This study reveals that the presence or absence of Hp exerts important time- and age-dependent influences on ICH outcomes. • Haptoglobin deletion improves ICH outcomes in two complimentary preclinical models. • Hp−/− mice have less ICH-induced brain damage and better neurological functioning. • Haptoglobin deficiency has temporal- and age-dependent influences on outcomes. [ABSTRACT FROM AUTHOR]

Multiple molecular events are involved in non-alcoholic steatohepatitis (NASH). There is no consensus on the role of inducible nitric oxide synthase (iNOS) in the progression of NASH. The present study therefore investigated the role of iNOS in NASH pathogenesis using bone marrow-transplanted iNOS chimeric mice under high-fat diet (HFD) conditions. The chimeric mice were fed a HFD for 16 wk, and primary hepatocytes were stimulated with oleic acid (OA). The molecular mechanisms underlying the role of iNOS in NASH were investigated. Marked hepatic steatosis and injury observed in the HFD mice and OA-stimulated hepatocytes were reduced by hepatocyte-derived iNOS. Mechanistically, iNOS upregulated heme oxygenase 1 (HO-1) by augmenting nuclear factor erythroid 2-related factor 2 (Nrf-2) binding to the HO-1 gene promoter. In conclusion, hepatocyte-derived iNOS may play a protective role against the progression of NASH by upregulating HO-1 through Nrf-2. Upregulation of hepatocellular iNOS may represent a potentially new therapeutic paradigm to combat NASH. ● The role of iNOS in NASH remains a matter of debate ● Hepatocyte-specific iNOS reduced the development of NASH ● iNOS modulated HO-1 expression through Nrf2 [ABSTRACT FROM AUTHOR]

Honokiol, the main bioactive component of Magnolia officinalis, has a variety of pharmacological actions. However, its toxicity has rarely been reported. According to previous studies performed in our laboratory, honokiol microemulsion has embryo developmental toxicity. For further exploration, Zebrafish embryos were exposed to different doses of honokiol microemulsion to record the rates of mortality, malformation, and hatching. We found that high doses of honokiol microemulsion (0.6 and 0.9 μg/ml) increased mortality, inhibited hatching, caused malformation and reduced swimming activities. The low-dose group (0.15 and 0.30 μg/ml) had decreased production of reactive oxygen species (ROS), but the high-dose group had inhibited superoxide dismutase (SOD) enzyme activity and increased ROS content. The mRNA expression of sod1 , sod2 , catalase(cat) , and heme oxygenase 1 (ho1) was up-regulated at low doses but down-regulated at high doses. The nuclear factor E2-related factor 2 (Nrf2) mRNA expression increased at low doses but decreased at high doses. After knocking down Nrf2 in zebrafish embryos, the rates of mortality and malformation were markedly increased and the hatching rate was significantly decreased. These results suggest that honokiol has antioxidative effects at low doses but causes embryo-developmental toxicity at high doses, and the Nrf2 gene may play a pivotal role in regulating these processes. • Low dose of honokiol produced antioxidaitve effects. • High dose of honokiol promoted oxidative stress-induced toxicity. • High dose of honokiol raised mortality and malformation but reduced hatching rate. • Nrf2 regulated the antioxidation and developmental toxicity of honokiol. [ABSTRACT FROM AUTHOR]

Abstract We previously confirmed that Nuclear factor erythroid 2-related factor-2 (Nrf2) and heme oxygenase (HO-1) play synergistic roles in the pathogenesis of preeclampsia. To further explore the function of HO-1 in the pathogenesis of preeclampsia, we established oxidative stress models respectively with human first-trimester trophoblast/simian virus (HTR8/SVneo) and human umbilical vein endothelial cells (HUVECs) and then assessed the effect of HO-1 on the two cell lines in oxidative stress conditions. The cell oxidative stress models were incubated with Hemin (an inducer of HO-1), then, the HTR8/SVneo cells were transfected by ZO-1 small interfering RNA (siRNA). The HTR-8/SVneo invasive abilities were detected, and the tube formation abilities of HUVECs were measured. HO-1 and tight junction proteins zonula occludens-1 (ZO-1) and occludin in the cells were detected. In both the trophoblastic and HUVEC oxidative stress models, HO-1、ZO-1 and occludin were increased incubated with Hemin. Meanwhile, HTR-8/SVneo cells incubated with Hemin showed increased invasion function against the destruction of hydrogen peroxide (H 2 O 2). Similarly, the tube formation ability of HUVECs incubated with Hemin was increased. The above-mentioned effects were disappeared after HTR-8/SVneo cells were transfected by ZO-1 siRNA. These results suggest that HO-1 protects the function of placental cells in oxidative stress via regulating ZO-1/occludin. Highlights • We established HTR8/SVneo cells and HUVECs oxidative stress models. • An inducer of HO-1 regulated on ZO-1 and occludin in the two type of cells on oxidative stress. • Treated by Hemin, HTR8 cells invasion and tube formation of HUVECs enhanced in oxidative stress. • The above effects were disappeared after HTR8/SVneo cells were transfected by ZO-1 siRNA. [ABSTRACT FROM AUTHOR]

Abstract Objectives This study was aimed to develop small molecule inhibitors of the P. aeruginosa heme oxygenase (pa -HemO) as potential treatment of infections caused by P. aeruginosa. Methods New compounds were designed based on the crystal structure of pa -HemO. The binding affinities (K D) were determined using intrinsic fluorescence quenching assays. The anti-microbial effects of the new compounds was evaluated by minimal inhibitory concentration 50% (MIC 50). Results Eleven compounds were synthesized as potential pa -HemO inhibitors. New compounds demonstrated K D values ranging from 1.5 to 180 μ M, and MIC 50 values ranging from 26 to 260 μg/mL. The compounds had good affinity with HemO and promising anti-microbial effects on P. aeruginosa. Conclusions The new inhibitors described herein can inhibit the growth of P. aeruginosa via the inhibition of pa -HemO. There may be broad prospects for HemO inhibitors to treat P. aeruginosa related infections. Highlights • Inhibitors of pa-HemO were developed to suppress the binding of heme to HemO and the use of heme by P. aeruginosa. • New compounds were designed based on the x-ray crystal structure of pa-HemO. • The development of these new HemO inhibitors will help open up new avenues for the treatment of P. aeruginosa infections. [ABSTRACT FROM AUTHOR]

Abstract Methyl 3,4 dihydroxybenzoate (MDHB) is a small molecule that shows neuroprotective effects in vitro and in a photoreceptor-degenerative mouse model. Here we investigated whether MDHB protects retina in a mouse model of acute ocular hypertension (AOH) and explores the underlying mechanisms. AOH was induced in mice by increasing intraocular pressure to approximately 90 mmHg for 60 min, then MDHB or vehicle was intraperitoneally injected daily up to 7 days. Immunostaining and multi-electrode array recordings were performed to examine the structure and function of retinas receiving the treatments. Western-blotting was applied to test the expression of several proteins related to oxidative stress and brain-derived neurotrophic factor (BDNF)-initiated signaling. Results showed that AOH injury reduced the number of Brn3a-stained retinal ganglion cells (RGCs) and ChAT-amacrine cells; thinned the inner retinal layers and induced apoptosis. Physiologically, AOH decreased the response of OFF and ON-OFF RGCs. All of these changes were reversed by MDHB-treatment. Mechanistically, MDHB appeared to work on three parallel pathways: (1) MDHB decreased the production of reactive oxygen species, the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and cytosol heme oxygenase 1 (HO-1); (2) It upregulated the expression of BDNF and its receptor tropomyosin-related kinase B (TrkB), and activated the downstream AKT pathways; (3) It inhibited reactive gliosis by reducing GFAP and Iba-1 expression. Thus our results suggest that MDHB protects retina against AOH injury by inhibiting oxidative stress, activating the BDNF/AKT signaling and inhibiting inflammatory pathways. Therefore, MDHB may serve as a promising candidate to treat retinal ischemia. Highlights • MDHB protects retinal structure against acute ocular hypertension (AOH) injury. • MDHB protects light responses of retinal ganglion cell against AOH injury. • MDHB inhibits oxidative stress and inflammation caused by AOH. • MDHB activates BDNF/AKT pathway after AOH. [ABSTRACT FROM AUTHOR]

Abstract Garlic has been demonstrated to exert protective effects against oxidative damage using numerous experimental models. The antioxidant effects of garlic are associated with the activation of Nrf2-dependent gene expression. S -1-Propenylcysteine (S1PC) and S -allylcysteine (SAC) are two predominant sulfur amino acids present in aged garlic extract; however, the exact roles of these amino acids within the Keap1/Nrf2 system remain unknown. We hypothesized that sulfur-containing amino acids derived from garlic could activate Nrf2 in the presence of nitric oxide (NO). Neither S1PC nor SAC affected gene expression of either heme oxygenase-1 (HMOX1) or the glutamate-cysteine ligase modifier subunit (GCLM) in human umbilical vein endothelial cells (HUVECs) or human aorta endothelial cells (HAECs). Interestingly, S1PC augmented expression levels induced by nitric oxide donors (NO-donors) such as NOR3 and GSNO. NO-donors were found to induce nuclear accumulation of NRF2 and activation of the eIF2α/ATF4 pathway, whereas S1PC did not further amplify the NO-induced effects on NRF2 or eIF2α/ATF4. Additionally, NO-donors induced the degradation of BTB domain and CNC homolog 1 (BACH1), a transcriptional repressor that can compete with NRF2. In addition, S1PC enhanced BACH1 downregulation within the nucleus. Pretreatment with deferoxamine, an inhibitor of heme synthesis, upregulated BACH1 protein levels and abolished the effect of NO-donors and S1PC on HMOX1 expression. The above results indicate that S1PC could modulate antioxidant gene expression via the NO/heme/BACH1 signaling pathway, thereby suggesting that S1PC-induced degradation of BACH1 may provide a basis for therapeutic applications. Graphical abstract Image 1 Highlights • S1PC is a sulfur-containing amino acid isolated from aged garlic extract. • S1PC enhanced HMOX1 and GCLM gene expression in a NO-dependent manner. • NO-donors induced NRF2 accumulation, EIF2A phosphorylation, and BACH1 degradation. • S1PC enhanced BACH degradation in the nucleus, not NRF2 accumulation. [ABSTRACT FROM AUTHOR]

Abstract Background The neuroprotection and neurotoxicity induced by sevoflurane have been gradually established. Choosing anesthetic agents after hemorrhage shock and resuscitation (HSR) induced by bleeding can be challenging. We determined the dual neuroprotective-neurotoxic effects of sevoflurane postconditioning after HSR injury using a model of blood loss and reinfusion in rats via the heme oxygenase-1 (HO-1)/reactive oxygen species (ROS) signal pathway. Methods The rats were exposed to 2%-4% sevoflurane postconditioning in vivo after HSR. Learning ability was assessed 30 d after HSR by Morris water maze tests. Hippocampal apoptosis was assessed 7 d after HSR by TdT-mediated dUTP nick-end labeling combined with cleaved caspase-3 (17 kDa). The ROS, mitochondrial membrane potential (MMP), HO-1 expression, and HO activity 1 d after HSR were assessed by fluorometric, JC-1, Western blot, and bilirubin assays, respectively. Results Compared with HSR alone, 2% sevoflurane postconditioning improved latency and increased MMP levels, HO-1 expression, and HO activity but decreased TdT-mediated dUTP nick-end labeling-positive cells, cleaved caspase-3 (17 kDa) expression, and ROS production. Pretreatment with hemin, an HO-1 agonist, reversed these effects. Compared with 2% sevoflurane postconditioning plus HSR, slower latency; decreased MMP levels; and increased TdT-mediated dUTP nick-end labeling-positive cells, cleaved caspase-3 (17 kDa), HO-1 expression, HO activity, and ROS production were shown in HSR plus 4% sevoflurane postconditioning, whereas Tin-mesoporphyrin, an HO-1 inhibitor, partially reversed the neurodegeneration of 4% sevoflurane postconditioning. Conclusion The dual neuroprotective-neurotoxic effects of 2%-4% sevoflurane postconditioning after HSR injury might be associated with increased ROS via the "threshold effect" of HO-1. [ABSTRACT FROM AUTHOR]

Abstract Radiation therapy toward malignancies is often ineffective owing to radioresistance of cancer cells. On the basis of anti-tumor properties of cordycepin, we examined the effects of cordycepin on sensitizing breast cancer cells toward radiotherapy. Cordycepin administration promoted G2/M arrest and apoptosis of MCF-7 and MDA-MB-231 cells resulting in restraining the proliferation of the cells in vitro and in vivo following irradiation. Mechanistic investigations showed that the breast cancer cells cultured with cordycepin harbored higher levels of intracellular reactive oxygen species (ROS) and incremental numbers of γ-H2AX foci after irradiation exposure. Importantly, cordycepin treatment down-regulated the expression levels of Nuclear factor erythroid 2-related factor (Nrf2) and a series of downstream genes, such as heme oxygenase-1 (HO-1), to enhance ROS in breast cancer cells exposed to irradiation. Together, our observations demonstrate that cordycepin treatment sensitizes breast carcinoma cells toward irradiation via Nrf2/HO-1/ROS axis. Thus, our findings provide novel insights into the function and the underlying mechanism of cordycepin in radiotherapy, and suggest that cordycepin might be employed as a radiosensitizer during radiotherapy toward breast cancer in a pre-clinical setting. Highlights • Cordycepin sensitizes breast carcinoma cells toward irradiation covering TNBC. • Cordycepin administration induces DNA damage following irradiation. • Cordycepin hijacks Nrf2/HO-1/ROS axis to sensitize breast cancer cells toward IR. • Clinically, cordycepin might be employed as a radiosensitizer for breast cancer. [ABSTRACT FROM AUTHOR]

Abstract In recent years, transplantation of mesenchymal stem cells (MSCs) has attracted much attention as a potential cell-based therapy for acute liver failure (ALF). As an inducible enzyme, heme oxygenase 1 (HO-1) has been reported to have cytoprotective, anti-apoptotic and immunoregulatory effects. Autophagy, a conserved catabolic process in cells, may be an important pathway for MSCs to treat ALF. In this study, we aimed to explore whether MSCs treat ALF by regulating autophagy and whether HO-1 was involved in the same pathway. Bone marrow-derived MSCs were isolated from Sprague-Dawley rats and cultured according to an established protocol. Co-culture systems of MSCs and hepatocytes were used to assess autophagy in the treatment of ALF. Meanwhile, MSCs were transplanted into rats with d -galactosamine (Gal)-induced ALF. Autophagy inhibitor (3-methyladenine, 3-MA), HO-1 inhibitor (zinc protoporphyrin, ZnPP) and PI3K specific inhibitor (LY294002) were employed in the study. Blood samples and liver tissues were collected before euthanasia. Survival rate, liver function, inflammatory factors, histology, Ki67 and TUNEL staining were determined. MSCs transplantation alleviated ALF both in vivo and in vitro. Autophagy and autophagy-related proteins were significantly up-regulated during MSCs treatment. 3-MA attenuated the therapeutic effect of MSCs. Administration of LY294002 before ALF induction inhibited hepatocyte autophagy. During the MSCs treatment, the HO-1 expression was increased, while inhibiting HO-1 attenuated the therapeutic effect of MSCs as well as hepatocyte autophagy. These findings suggested MSCs could alleviate ALF by increasing the HO-1 expression, which played an important role in activating autophagy through PI3K/AKT signaling pathway. [ABSTRACT FROM AUTHOR]

Abstract Background Diabetic erectile dysfunction (DMED) is mainly attributed to oxidative stress, and Nrf2 plays an important role in cellular antioxidation and regulates NO production in the vascular endothelium. Probucol maintains endothelial function through its antioxidant activity. This study investigated the efficacy and mechanism of probucol in improving erectile function in streptozotocin-induced diabetic rats. Methods In our study, thirty 12-week-old Sprague-Dawley male rats were fasted for 12 h. All rats received a 1-time injection of intraperitoneal streptozotocin(60 mg/kg) or vehicle. After 72 h, STZ-treated rats (with random blood glucose concentrations consistently greater than 16.7 mmol/L) were considered diabetic. The diabetic rats were randomly assigned into 2 groups and treated with daily gavage feedings of probucol at doses of 0 and 500 mg/kg for 12 weeks. A positive control group underwent intraperitoneal injection of normal saline followed by daily gavage of saline solution. Erectile function was assessed by electrical stimulation of the cavernous nerves with real-time intracavernous pressure measurement. After euthanasia, penile tissue was investigated using immunohistochemistry, Western blot, and ELISA to assess the proteins of Nrf2/HO-1/DDAH/PPAR-γ/eNOS pathways. Results After treatment, the rats in the probucol group presented significantly improved erectile function (P < 0.05) than that of the diabetic group without probucol treatment (DM). Also, protein expression of Nrf2, DDAH, PPAR-γ, HO-1 and eNOS was significantly higher than that of the DM group (P < 0.05). CGMP concentrations and SOD concentrations of probucol-treated rats were higher than those of DM group (P < 0.05). The MDA levels and ADMA levels were significantly lower than those of DM group rats (P < 0.05). Conclusion Probucol can improve erectile function via activation of Nrf2, which coordinates the HO-1/DDAH/PPAR-γ/eNOS pathways in streptozotocin-induced diabetic rats. [ABSTRACT FROM AUTHOR]

Abstract Coumarin forms an elite class of naturally occurring compounds that possess promising antiviral therapeutic perspectives. In the previous study, we designed and synthesized a coumarin derivative, 7-(4-benzimidazole-butoxy)-coumarin (BBC), to evaluate its antiviral activity on spring viraemia of carp virus (SVCV). In this study, our results show that BBC does not affect viral adhesion and delivery from endosomes to the cytosol, indicating BBC has no inhibitory activity in the early stage of viral infection. Further data are determined that BBC significantly declines SVCV-infected apoptosis and recovers caspase-3/8/9 activity. To reveal the pathway that affects Nrf2 translocation by BBC, we examine changes in protein kinase C (PKC) in EPC cells treated with BBC. We observe that BBC results in a higher phosphorylation of PKCα/β that is involved in the activation of erythroid 2-related factor 2 (Nrf2) phosphorylation to favor Nrf2 translocation to nucleus at 24 and 48 h. In addition, the results show that BBC also up-regulates both antiviral responses, heme oxygenase-1 (HO-1) expression and cellular IFN response. Overall, this mechanism of action provides a new therapeutic target for the treatment of SVCV infection, and these results suggest that treatment with BBC is effective in reducing SVCV infection and differently regulates SVCV-induced undesirable conditions. Highlights • BBC effectively inhibits SVCV replication in host cells. • BBC can enhance PKC phosphorylation to activate Nrf2 expression and translocation to nucleus. • BBC up-regulates heme oxygenase-1 (HO-1) expression in addition to cellular IFN response. [ABSTRACT FROM AUTHOR]

Abstract Rapamycin (sirolimus) is employed as an immunosuppressant following liver transplant, to inhibit the re-growth of cancer cells following liver resection for hepatocellular carcinoma (HCC), and for the treatment of advanced HCC. Rapamycin also induces the expression of antioxidant enzymes in the liver, suggesting that pretreatment with the drug could provide a potential strategy to reduce ischemia reperfusion injury following liver surgery. The aim of this study was to further investigate the actions of rapamycin in inducing expression of the antioxidant enzymes heme oxygenase-1 (HO-1) and peroxiredoxin-1 (Prx-1) in normal liver and in tumorigenic liver cells. A rat model of segmental hepatic ischemia and reperfusion, cultured freshly-isolated rat hepatocytes, and tumorigenic H4IIE rat liver cells in culture were employed. Expression of HO-1 and Prx-1 was measured using quantitative PCR and western blot. Rapamycin pre-treatment of normal liver in vivo or normal hepatocytes in vitro led to a substantial induction of mRNA encoding HO-1 and Prx-1. The dose-response curve for the action of rapamycin on mRNA expression was biphasic, showing an increase in expression at 0 - 0.1 μM rapamycin but a decrease from maximum at concentrations greater than 0.1 μM. By contrast, in H4IIE cells, rapamycin inhibited the expression of HO-1 and Prx-1 mRNA. Oltipraz, an established activator of transcription factor Nrf2, caused a large induction of HO-1 and Prx-1 mRNA. The dose response curve for the inhibition by rapamycin of HO-1 and Prx-4 mRNA expression, determined in the presence of oltipraz, was monophasic with half maximal inhibition at about 0.01 μM. It is concluded that, at concentrations comparable to those used clinically, pre-treatment of the liver with rapamycin induces the expression of HO-1 and Prx-1. However, the actions of rapamycin on the expression of these two antioxidant enzymes in normal hepatocytes are complex and, in tumorigenic liver cells, differ from those in normal hepatocytes. Further studies are warranted to evaluate preconditioning the livers of patients subject to liver resection or liver transplant with rapamycin as a viable strategy to reduce IR injury following liver surgery. Highlights • Rapamycin induces expression of heme oxygenase-1 and peroxiredoxin-1 in hepatocytes. • Biphasic dose-response curve for antioxidant enzyme induction in normal hepatocytes. • Rapamycin inhibits expression of the antioxidant enzymes in tumorigenic liver cells. • Rapamycin pre-treatment may provide strategy to reduce liver ischemia reperfusion injury. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • A scaffold-hopping approach was utilized to design novel HO-1 inhibitors. • A total of 1500 new compounds were virtually evaluated. • Compound 5 was identified as a new led compound with an IC 50 of 0.9 μM on HO-1. Abstract HO-1 inhibition is considered a valuable anticancer approach. In fact, up-regulation of HO-1 had been repeatedly reported in many types of human malignancies, and in these clinical cases, poor outcomes are reported. To identify novel HO-1 inhibitors suitable for drug development, a scaffold-hopping strategy calculation was utilized to design novel derivatives. Different parts of the selected molecule were analyzed and the different series of novel compounds were virtually evaluated. The calculation for the linker moiety of the classical HO-1 inhibitors structure led us to compounds 5 and 6. A synthetic pathway for the two molecules was designed and the compounds were synthesized. The biological activity revealed an HO-1 inhibition of 0.9 and 54 μM for molecules 5 and 6 respectively. This study suggested that our scaffold-hopping approach was successful and these results are ongoing for further development. [ABSTRACT FROM AUTHOR]

Abstract Heme oxygenase-1 (HO-1) is an inducible enzyme responding to various stresses and has cytoprotective activities. Although HO-1 has been referred to as heat shock protein (HSP) 32, the heat-mediated induction of HO-1 varies among different species and cell lines. We examined the effects of heat shock on HO-1 expression in mouse embryonic fibroblast (MEF) cells deficient in heat shock factor 1 (HSF1) or nuclear factor-erythroid-2-related factor 2 (NRF2). Heme-induced expression of HO-1 was 2-fold higher in Hsf1 −/− cells than in the wild-type cells at both mRNA and protein levels. In Nrf2 −/− cells, heme-induced expression of HO-1 was not detected. In contrast, HO-1 expression was markedly induced by heat shock at 40–42 °C in Nrf2 −/− cells while the wild-type cells were not responsive. The heat-induced expression of HO-1 in Nrf2 −/− cells were almost completely diminished by transfection of siRNA against Hsf1 gene. These results suggest that HSF1 and NRF2 suppress heme-induced and heat-induced HO-1 expression, respectively. [ABSTRACT FROM AUTHOR]

Abstract Non-thermal plasma (NTP) treatment has been proposed as a potential approach for cancer therapy for killing cancer cells via generation of reactive oxygen species (ROS). As an antioxidant protein, Heme oxygenase-1 (HO-1) has been known to protect cells against oxidative stress. In this paper, we investigated the role of HO-1 activation in NTP-induced apoptosis in A549 cells. Distinctly increased ROS production and apoptosis were observed after NTP exposure. NTP exposure induced HO-1 expression in a dose- and time-dependent manner via activating the translocation of Nuclear factor (erythroid-derived 2)-like 2 (Nrf2) from cytoplasm to nucleus. Furthermore, inhibiting HO-1 activation with its specific inhibitor, ZnPP, increased "killing" effect of NTP. Knocking down HO-1 or Nrf2 with the special siRNA also led to elevated ROS level and enhanced NTP-induced cell death. In addition, the c-JUN N-terminal kinase (JNK) signaling pathway was shown to be involved in NTP-induced HO-1 expression. Interestingly, a higher resistance to NTP exposure of A549 cell compared to H1299 and H322 cells was found to be linked to its higher basal level of HO-1 expression. These findings revealed that HO-1 could be considered as a potential target to improve the effect of NTP in cancer therapy. [ABSTRACT FROM AUTHOR]

Diabetes affects cardiac structure and function, where it leads to diabetic cardiomyopathy. Reactive oxygen species (ROS) produced by oxidative stress play an important role in the development of diabetic cardiomyopathy. Fibroblast growth factor (FGF) 19, an enterokine, is synthesized and released into the ileum. In the present study, we revealed that FGF19 induced an antioxidant response through stimulating the expression of nuclear erythroid factor 2 (NE-F2)-related factor 2 (Nrf2) and as well as reducing ROS production through the AMPK signaling pathway. Additionally, AMPK inhibition by the AMPK-specific inhibitor compound C decreased Nrf2 and heme oxygenase-1 (HO-1) protein expression. Taken together, these results suggested that FGF19, through the anti-oxidative defense system, attenuated the development of diabetic cardiomyopathy and restored cardiac function. [ABSTRACT FROM AUTHOR]

Alternative splicing is a routine phenomenon which greatly increases the diversity of proteins in eukaryotic cells. In humans, most multi-exonic genes are alternatively spliced and their splice variants confer distinct functions. Heme oxygenase-1 (HO-1, 32 kDa) is an inducible stress responsive protein, which possesses multiple functions in many cellular processes. In the current study, we identified a novel alternative splice isoform of 14 kDa HO-1 generated through exclusion of exon 3, and it is highly expressed in immortalized cells. In contrast to nuclear accumulation of the full-length 32 kDa HO-1, the novel 14 kDa HO-1 isoform is retained in the cytoplasm under ultraviolet (UV) irradiation. Interestingly, the 14 kDa HO-1 is shown to promote cell proliferation and an increase in relative telomere lengths in vivo and in vitro . Thus, we are pioneer to report and confirm the presence of a novel splice form of HO-1 and its distinct role in modulating telomere length and tumor growth. [ABSTRACT FROM AUTHOR]

Phagocytosis of pathogens by macrophages is crucial for the successful resolution of inflammation induced by microbial infection. Taurine chloramine (TauCl), an endogenous anti-inflammatory and antioxidative substance, is produced by reaction between taurine and hypochlorous acid by myeloperoxidase activity in neutrophils under inflammatory conditions. In the present study, we investigated the effect of TauCl on resolution of acute inflammation caused by fungal infection using a zymosan A-induced murine peritonitis model. TauCl administration reduced the number of the total peritoneal leukocytes, while it increased the number of peritoneal monocytes. Furthermore, TauCl promoted clearance of pathogens remaining in the inflammatory environment by macrophages. When the macrophages isolated from thioglycollate-treated mice were treated with TauCl, their phagocytic capability was enhanced. In the murine macrophage-like RAW264.7 cells treated with TauCl, the proportion of macrophages clearing the zymosan A particles was also increased. TauCl administration resulted in elevated expression of heme oxygenase-1 (HO-1) in the peritoneal macrophages. Pharmacologic inhibition of HO-1 activity or knockdown of HO-1 in the murine macrophage RAW264.7 cells abolished the TauCl-induced phagocytosis, whereas the overexpression of HO-1 augmented the phagocytic ability of macrophages. Moreover, peritoneal macrophages isolated from HO-1 null mice failed to mediate TauCl-induced phagocytosis. Our results suggest that TauCl potentiates phagocytic activity of macrophages through upregulation of HO-1 expression. [ABSTRACT FROM AUTHOR]

Heme oxygenase-1 (HO-1) has been implicated in tumor progression, but the underlying molecular mechanisms remain largely unknown. Transforming growth factor-β1 (TGF-β1) exhibits cytostatic and apoptotic effects in hepatocytes and several types of hepatocellular carcinoma (HCC) cell lines, and deregulation of its signaling pathway is linked to hepatic tumorigenesis. In the present study, we observed that HO-1 is expressed at higher levels in HCC tissues than in paired normal tissues. Moreover, TGF-β1-induced cell cycle arrest and up-regulation of cyclin-dependent kinase inhibitors in HCC cell lines were significantly attenuated by overexpression of HO-1 or treatment with tricarbonyldichlororuthenium(II) dimer ([Ru(CO) 3 Cl 2 ] 2 , suggesting an inhibitory role of the HO-1/CO axis in TGF-β signaling to growth inhibition in HCC cell lines. Interestingly, we observed that [Ru(CO) 3 Cl 2 ] 2 inhibits TGF-β1-induced Smad3-dependent reporter activity without affecting its C-terminus phosphorylation, complex formation with Smad4, and nuclear translocation. Additional experiments revealed that HO-1/CO axis selectively induces phosphorylation of Smad3 at Thr-179 residue in the linker region through activation of extracellular signal-activated kinase (ERK) 1/2. Transfection with a phospho-deficient Smad3 (T179A) mutant or treatment with FR180204, a specific inhibitor for ERK1/2, significantly reversed the inhibitory effects of HO-1 and [Ru(CO) 3 Cl 2 ] 2 on cell cycle arrest induced by TGF-β1. These findings for the first time demonstrate that HO-1/CO axis confer resistance of HCC cells to TGF-β growth inhibitory signal by increasing Smad3 phosphorylation at Thr-179 via ERK1/2 pathway. [ABSTRACT FROM AUTHOR]

Ischemia reperfusion injury is a critical factor in the recovery process after intestine trauma and the functional restoration of intestinal reconstruction. This study was the first to explore the expression of apical junctional complex (AJC) induced by heme oxygenase-1 (HO-1) in Caco-2 cells in oxygen-glucose deprivation (OGD) models. Here we showed that HO-1 was upregulated after OGD. Notably, activation of HO-1 largely enhanced the expression of AJC proteins including Claudin-4, E-cadherin and β-catenin in Caco-2 cells, but decreased the expression of matrix metalloproteinase 9 (MMP9). Knockdown of HO-1 attenuated the OGD-induced overexpression of AJC proteins but promoted the expression of MMP9. Interestingly, inhibition of MMP9 further enhanced AJC expression. These results suggest that HO-1 is involved in OGD-evoked upregulation of AJC proteins, which is partly mediated by MMP9 pathway. High expression of HO-1 may play an important role in the pathophysiological process of ischemia reperfusion injury and has potential clinical value for the treatment of intestine related diseases. [ABSTRACT FROM AUTHOR]

Heme oxygenase (HO) catalyzes the degradation of toxic free heme to the equimolar amounts of biliverdin, Fe 2+ and concurrently releases of carbon monoxide (CO). CO is nowadays increasingly recognized as an important signaling molecule throughout the body that is involved in many physiological processes and shows multidirectional biological activity. Recent evidence indicates that CO exhibits the anti-inflammatory, anti-proliferative, anti-apoptotic, anti-aggregatory and vasodilatory properties. The cellular mechanisms underlying the activity of CO involve stimulation of cGMP-dependent signaling pathway and large conductance calcium activated K + channels, the activation of mitogen-activated protein kinases and the nuclear factor k-light chain-enhancer of activated B cells transcription factor pathway. Stimulation of endogenous CO production by HO inducers or the inhalation of CO or the delivery of this gaseous molecule by novel pharmaceutical agents have been found in experimental animal models to be promising in the future therapy of various diseases. CO appears to act as a significant component of the complex mechanism of gastrointestinal (GI) mucosal defense. This gaseous molecule plays an important role in diabetic gastroparesis, prevention of the upper GI mucosal damage, post-operative ileus and the healing of ulcerative colitis. This review focuses on the better understanding mechanisms through which CO contributes to the mechanism of protection, resistance to injury and ulcer healing. It is becoming apparent that the pleiotropic effect of this molecule may increase clinical applicability of CO donors and their implementation in many pharmacological research areas, pharmaceutical industry and health-care system. [ABSTRACT FROM AUTHOR]

Endoplasmic reticulum (ER) stress, which is defined as the accumulation of unfolded or misfolded proteins in the ER, triggers cellular dysfunction and eventually leads to cell death. In particular, excessive and prolonged ER stress is closely related with hepatic injury. Adiponectin, a hormone predominantly produced by adipose tissue, is known to possess potent hepatoprotective properties and exhibits a cytoprotective effect in response to chronic ER stress. However, the underlying mechanisms are not clearly understood. In the present study, we examined the protective effect of globular adiponectin (gAcrp) on tunicamycin-induced cell death and further investigated its potential underlying mechanisms in rat hepatocytes. Herein, we found that treatment with gAcrp inhibited tunicamycin-induced cell death, decreased lactate dehydrogenase release (marker of pyroptotic cell death), and suppressed caspase activation; clearly indicating that gAcrp protects liver cells from ER stress. Interestingly, gAcrp prevented the tunicamycin-induced activation of the inflammasome, a key platform involved in the production of inflammatory cytokines that induces pyroptosis, determined by suppression of interleukin-1β (IL-1β) maturation, apoptosis-associated speck-like protein containing a carboxy-terminal CARD (ASC) speck formation, and caspase-1 activation. Moreover, we showed that suppression of the inflammasome activation by gAcrp was mediated via modulation of reactive oxygen species (ROS) production, particularly inhibition of NADPH oxidase. In addition, inhibition of heme oxygenase-1 (HO-1) signaling by pretreatment with SnPP, a pharmacological inhibitor of HO-1, or transfection with an siRNA targeting HO-1, abrogated the protective effects of gAcrp against tunicamycin-induced cell death and abolished the suppressive effect on the inflammasome activation, demonstrating that HO-1 signaling plays a crucial role in the protective effect of gAcrp against tunicamycin-induced damage in liver cells. Taken together, these results indicate that gAcrp protects liver cells from ER stress by modulating inflammasomes activation, at least in part, via HO-1 signaling-dependent mechanisms. [ABSTRACT FROM AUTHOR]

Here, we report thyroid transcription factor 1 (TTF-1) as an important transcription factor for the expression of heme oxygenase-1 (HO-1). HO-1 is a well-known cytoprotective enzyme against inflammation. We observed that HO-1 co-expressed with TTF-1 in mouse hypothalamic cells. Results from luciferase and chromatin immunoprecipitation assays revealed that TTF-1 directly activated HO-1 transcription by binding to binding domains in the 5′-flanking region of the HO-1 gene. A proinflammatory cytokine, tumor necrosis factor-alpha (TNF-α), induced nuclear translocation of TTF-1 and increased binding affinity of TTF-1 to its binding sites on the HO-1 gene. HO-1 mRNA increased with TTF-1 overexpression but decreased with RNA interference of TTF-1 expression in rat astroglial C6 cells. Together with results showing involvement of TTF-1 in the TNF-α-induced increase in interleukin 1 beta and monocyte chemotactic protein 1 production, this study suggests that TTF-1 plays an important role in the mouse hypothalamus TNF-α-induced inflammatory response for regulating HO-1 gene expression. [ABSTRACT FROM AUTHOR]