Oxygen Species Production Research Articles

ASK1 is a novel molecular target for preventing aminoglycoside-induced hair cell death

Aminoglycoside antibiotics are lifesaving medicines, crucial for the treatment of chronic or drug resistant infections. However, aminoglycosides are toxic to the sensory hair cells in the inner ear. As a result, aminoglycoside-treated individuals can develop permanent hearing loss and vestibular impairment. There is considerable evidence that reactive oxygen species (ROS) production and the subsequent phosphorylation of c-Jun N-terminal kinase (JNK) and P38 mitogen-activated protein kinase (P38) drives apoptosis in aminoglycoside-treated hair cells. However, treatment strategies that directly inhibit ROS, JNK, or P38 are limited by the importance of these molecules for normal cellular function. Alternatively, the upstream regulator apoptosis signal-regulating kinase 1 (ASK1/MAP3K5) is a key mediator of ROS-induced JNK and P38 activation under pathologic but not homeostatic conditions. We investigated ASK1 as a mediator of drug-induced hair cell death using cochlear explants from Ask1 knockout mice, demonstrating that Ask1 deficiency attenuates neomycin-induced hair cell death. We then evaluated pharmacological inhibition of ASK1 with GS-444217 as a potential otoprotective therapy. GS-444217 significantly attenuated hair cell death in neomycin-treated explants but did not impact aminoglycoside efficacy against P. aeruginosa in the broth dilution test. Overall, we provide significant pre-clinical evidence that ASK1 inhibition represents a novel strategy for preventing aminoglycoside ototoxicity.Key messagesASK1 is an upstream, redox-sensitive regulator of P38 and JNK, which are known mediators of hair cell death.Ask1 knockout does not affect hair cell development in vivo, but significantly reduces aminoglycoside-induced hair cell death in vitro.A small-molecule inhibitor of ASK1 attenuates neomycin-induced hair cell death, and does not impact antibiotic efficacy in vitro.ASK1 may be a novel molecular target for preventing aminoglycoside-induced hearing loss.

Lipid emulsion-induced hypertension post resection of pediatric neuroblastoma: a case report and literature review

BackgroundParenteral Nutrition (PN) is preferred when patient is unable to eat. Most clinically widely used lipid emulsion is now attracting more attention in its stability and adverse reactions. We report here the first case of lipid emulsions caused hypertension.Case presentationA 1.5 years old girl was diagnosed with neuroblastoma and underwent chemotherapy subsequently followed by resection surgery. She received PN for nutritional support after surgery. with the initiation of PN, this patient developed hypertension. Possible causes of hypertension were evaluated. After the discontinuation of lipid emulsions in PN, her hypertensive symptoms ceased. The lipid emulsion was therefore considered as the cause of her hypertension.ConclusionsThe pathogenesis of hypertension caused by fatty milk is possibly associated with increased production of reactive oxygen species, increased oxidative stress and vasoconstriction.

Toxicity Effects of Combined Mixtures of BDE-47 and Nickel on the Microalgae Phaeodactylum tricornutum (Bacillariophyceae).

Nickel and 2,2’,4,4’-tetrabromodiphenyl ether (BDE-47) are two environmental pollutants commonly and simultaneously present in aquatic systems. Nickel and BDE-47 are individually toxic to various aquatic organisms. However, their toxicity mechanisms are species-dependent, and the toxic effects of combined mixtures of BDE-47 and nickel have not yet been investigated. The present study investigated the toxic effects of combined mixtures of BDE-47 and nickel in the diatom Phaeodactylum tricornutum. BDE-47 and nickel mixtures significantly decreased cell abundance and photosynthetic efficiency, while these cells’ reactive oxygen species (ROS) production significantly increased. The EC50-72 h for BDE-47 and mixtures of BDE-47 and nickel were 16.46 ± 0.93 and 1.35 ± 0.06 mg/L, respectively. Thus, combined mixtures of the two pollutants enhance their toxic effects. Interactions between BDE-47 and nickel were evaluated, revealing synergistic interactions that contributed to toxicity in P. tricornutum. Moreover, transcriptomic analyses revealed photosynthesis, nitrogen metabolism, the biosynthesis of amino acids, the biosynthesis of secondary metabolites, oxoacid metabolism, organic acid metabolism, carboxylic acid metabolism, and oxidation-reduction processes were considerably affected by the mixtures. This study provides evidence for the mechanisms of toxicity from combined BDE-47 and nickel exposure while also improving our understanding of the ecological risks of toxic chemicals on microalgae.

INDUCTION OF NRF2 TRANSCTIPTION FACTOR INHIBITS FORMATION OF RACTIVE OXYGEN AND NITROGEN SPECIES IN LIVER OF RATS UNDER MODELLING METABOLIC SYNDROME BY EXPOSURE TO ROUND-THE-CLOCK LIGHTING

Aim: To evaluate the effect of dimethyl fumarate, an Nrf2 inducer, on the production of reactive oxygen and nitrogen species in the liver of rats under the conditions of modeling the metabolic syndrome with roundthe-clock illumination. Dimethyl fumarate in 10% dimethyl sulfoxide solution in a dose of 15 mg/kg was administered intraperitoneally to white rats over the modeled metabolic syndrome (a 20% aqueous fructose solution for drinking and a diet enriched with carbohydrates and lipids). In the liver homogenate of rats, the rate of generation of the superoxide anion radical (•О 2 ), the activity of total NO synthase (NOS), its constitutive and inducible isoforms (cNOS, iNOS), and the content of peroxynitrites of alkali and alkaline earth metals were determined. The administration of dimethyl fumarate under the experimental conditions significantly restrained the •О 2 production by microsomes and NOS in the liver tissues by 48.9%, by mitochondria by 47.3%, by leukocyte NADPH oxidase by 45.6%; it also reduced NOS activity (total and iNOS) by 33.1% and 35.9%, respectively, and the concentration of peroxynitrites by 39.7% compared with the values of the control group that received only the solvent (10% dimethyl sulfoxide solution). The cNOS activity and coupling index exceeded the control result in 2.95 and 5.5 times, respectively. The introduction of the Nrf2 inductor, dimethyl fumarate, during the simulation of the metabolic syndrome by round-the-clock lighting to rats is an effective means of limiting the production of reactive oxygen and nitrogen species in the liver tissues.

GSH Protects the Escherichia coli Cells from High Concentrations of Thymoquinone.

The aim of the present study was to evaluate the potential protective effect of glutathione (GSH) on Escherichia coli cells grown in a high concentration of thymoquinone (TQ). This quinone, as the main active compound of Nigella sativa seed oil, exhibits a wide range of biological activities. At low concentrations, it acts as an antioxidant, and at high concentrations, an antimicrobial agent. Therefore, any interactions between thymoquinone and glutathione are crucial for cellular defense against oxidative stress. In this study, we found that GSH can conjugate with thymoquinone and its derivatives in vitro, and only fivefold excess of GSH was sufficient to completely deplete TQ and its derivatives. We also carried out studies on cultures of GSH-deficient Escherichia coli strains grown on a minimal medium in the presence of different concentrations of TQ. The strains harboring mutations in gene ΔgshA and ΔgshB were about two- and fourfold more sensitive (256 and 128 µg/mL, respectively) than the wild type. It was also revealed that TQ concentration has an influence on reactive oxygen species (ROS) production in E. coli strains—at the same thymoquinone concentration, the level of ROS was higher in GSH-deficient E. coli strains than in wild type.

Components of Banisteriopsis caapi, a Plant Used in the Preparation of the Psychoactive Ayahuasca, Induce Anti-Inflammatory Effects in Microglial Cells.

Banisteriopsis caapi is used to prepare the psychoactive beverage ayahuasca, and both have therapeutic potential for the treatment of many central nervous system (CNS) conditions. This study aimed to isolate new bioactive compounds from B. caapi extract and evaluate their biological activity, and that of the known β-carboline components of the plant (harmine, harmaline, and tetrahydroharmine), in BV-2 microglial cells, the in vivo activation of which is implicated in the physiopathology of CNS disorders. B. caapi extract was fractionated using semipreparative liquid chromatography (HPLC-DAD) and the exact masses ([M + H]+ m/z) of the compounds in the 5 isolated fractions were determined by high-resolution LC-MS/MS: F1 (174.0918 and 233.1289), F2 (353.1722), F3 (304.3001), F4 (188.1081), and F5 (205.0785). Harmine (75.5–302 µM) significantly decreased cell viability after 2 h of treatment and increased the number of necrotic cells and production of reactive oxygen species at equal or lower concentrations after 24 h. F4 did not impact viability but was also cytotoxic after 24 h. Most treatments reduced proinflammatory cytokine production (IL-2, IL-6, IL-17, and/or TNF), especially harmaline and F5 at 2.5 µM and higher concentrations, tetrahydroharmine (9.3 µM and higher), and F5 (10.7 µM and higher). The results suggest that the compounds found in B. caapi extract have anti-inflammatory potential that could be explored for the development of treatments for neurodegenerative diseases.

MiRNA sequencing analysis of healthy and atretic follicles of chickens revealed that miR-30a-5p inhibits granulosa cell death via targeting Beclin1

BackgroundThe egg production performance of chickens is affected by many factors, including genetics, nutrition and environmental conditions. These factors all play a role in egg production by affecting the development of follicles. MicroRNAs (miRNAs) are important non-coding RNAs that regulate biological processes by targeting genes or other non-coding RNAs after transcription. In the animal reproduction process, miRNA is known to affect the development and atresia of follicles by regulating apoptosis and autophagy of granulosa cells (GCs).ResultsIn this study, we identified potential miRNAs in the atretic follicles of broody chickens and unatretic follicles of healthy chickens. We identified gga-miR-30a-5p in 50 differentially expressed miRNAs and found that gga-miR-30a-5p played a regulatory role in the development of chicken follicles. The function of miR-30a-5p was explored through the transfection test of miR-30a-5p inhibitor and miR-30a-5p mimics. In the study, we used qPCR, western blot and flow cytometry to detect granulosa cell apoptosis, autophagy and steroid hormone synthesis. Confocal microscopy and transmission electron microscopy are used for the observation of autophagolysosomes. The levels of estradiol (E2), progesterone (P4), malondialdehyde (MDA) and superoxide dismutase (SOD) were detected by ELISA. The results showed that miR-30a-5p showed a negative effect on autophagy and apoptosis of granulosa cells, and also contributed in steroid hormones and reactive oxygen species (ROS) production. In addition, the results obtained from the biosynthesis and dual luciferase experiments showed that Beclin1 was the target gene of miR-30a-5p. The rescue experiment conducted further confirmed that Beclin1 belongs to the miR-30a-5p regulatory pathway.ConclusionsIn summary, after deep miRNA sequencing on healthy and atretic follicles, the results indicated that miR-30a-5p inhibits granulosa cell death by inhibiting Beclin1.

Endurance exercise attenuates juvenile irradiation-induced skeletal muscle functional decline and mitochondrial stress

BackgroundRadiotherapy is commonly used to treat childhood cancers and can have adverse effects on muscle function, but the underlying mechanisms have yet to be fully elucidated. We hypothesized that endurance exercise following radiation treatment would improve skeletal muscle function.MethodsWe utilized the Small Animal Radiation Research Platform (SARRP) to irradiate juvenile male mice with a clinically relevant fractionated dose of 3× (every other day over 5 days) 8.2 Gy X-ray irradiation locally from the knee to footpad region of the right hindlimb. Mice were then singly housed for 1 month in cages equipped with either locked or free-spinning voluntary running wheels. Ex vivo muscle contractile function, RT-qPCR analyses, resting cytosolic and sarcoplasmic reticulum (SR) store Ca2+ levels, mitochondrial reactive oxygen species levels (MitoSOX), and immunohistochemical and biochemical analyses of muscle samples were conducted to assess the muscle pathology and the relative therapeutic impact of voluntary wheel running (VWR).ResultsIrradiation reduced fast-twitch extensor digitorum longus (EDL) muscle-specific force by 27% compared to that of non-irradiated mice, while VWR post-irradiation improved muscle-specific force by 37%. Radiation treatment similarly reduced slow-twitch soleus muscle-specific force by 14% compared to that of non-irradiated mice, while VWR post-irradiation improved specific force by 18%. We assessed intracellular Ca2+ regulation, oxidative stress, and mitochondrial homeostasis as potential mechanisms of radiation-induced pathology and exercise-mediated rescue. We found a significant reduction in resting cytosolic Ca2+ concentration following irradiation in sedentary mice. Intriguingly, however, SR Ca2+ store content was increased in myofibers from irradiated mice post-VWR compared to mice that remained sedentary. We observed a 73% elevation in the overall protein oxidization in muscle post-irradiation, while VWR reduced protein nitrosylation by 35% and mitochondrial reactive oxygen species (ROS) production by 50%. Finally, we found that VWR significantly increased the expression of PGC1α at both the transcript and protein levels, consistent with an exercise-dependent increase in mitochondrial biogenesis.ConclusionsJuvenile irradiation stunted muscle development, disrupted proper Ca2+ handling, damaged mitochondria, and increased oxidative and nitrosative stress, paralleling significant deficits in muscle force production. Exercise mitigated aberrant Ca2+ handling, mitochondrial homeostasis, and increased oxidative and nitrosative stress in a manner that correlated with improved skeletal muscle function after radiation.

Mitochondrial targeted astaxanthin liposomes for myocardial ischemia-reperfusion injury based on oxidative stress

Myocardial ischemia-reperfusion injury (MI/RI) refers to the clinical state of decreased coronary blood flow caused by various causes. The main pathogenesis of MI/RI is mitochondrial oxidative damage. In this study, we designed a novel mitochondrial targeted astaxanthin (AST) liposome, namely, STPP-AST-LIP, targeting mitochondria of H9c2 myocardial cells. STPP-AST-LIP not only reduced the production of mitochondrial reactive oxygen species (ROS), but also increased the survival rate of MI/RI H9c2 cells. In addition, rat experiments further confirmed that STPP-AST-LIP could improve myocardial cardiac function in MI/RI rats, significantly inhibited apoptosis of myocardial cells, and had a protective effect on the heart of rats after MI/RI.

Metabolomic Insights of the Effects of Bacterial Algicide IRI-160AA on Dinoflagellate Karlodinium veneficum.

Shewanella sp. IRI-160 is an algicidal bacterium that secretes an algicide, IRI-160AA. This algicide specifically targets dinoflagellates, while having no adverse effects on other algal species tested. Dinoflagellates exposed to IRI-160AA exhibited increased production of reactive oxygen species (ROS), DNA damage, and cell cycle arrest, implying a programmed pathway leading to cell death (PCD). Here, a metabolomic analysis was conducted on dinoflagellate Karlodinium veneficum and a control cryptophyte species Rhodomonas exposed to IRI-160AA to investigate the cellular mechanisms behind the physiological effects and the specificity of this algicide. Results of this research supported previous observations about physiological responses to the algicide. A suite of metabolites was identified that increased in the cell pellets of K. veneficum but not in Rhodomonas, including oxidative stress biomarkers, antioxidants, and compounds involved in DNA damage and PCD. Overall, the results of this study illustrated the metabolomic mechanisms underlying the algicidal effects of IRI-160AA on dinoflagellates. This research also provided insights and future directions for studies on the cellular response of dinoflagellates exposed to antagonistic bacteria in the environment.

PRMT5 critically mediates TMAO-induced inflammatory response in vascular smooth muscle cells

A high plasma level of the choline-derived metabolite trimethylamine N-oxide (TMAO) is closely related to the development of cardiovascular disease. However, the underlying mechanism remains unclear. In the present study, we demonstrated that a positive correlation of protein arginine methyltransferase 5 (PRMT5) expression and TMAO-induced vascular inflammation, with upregulated vascular cell adhesion molecule-1 (VCAM-1) expression in primary rat and human vascular smooth muscle cells (VSMC) in vitro. Knockdown of PRMT5 suppressed VCAM-1 expression and the adhesion of primary bone marrow-derived macrophages to TMAO-stimulated VSMC. VSMC-specific PRMT5 knockout inhibited vascular inflammation with decreased expression of VCAM-1 in mice. We further identified that PRMT5 promoted VCAM-1 expression via symmetrical demethylation of Nuclear factor-κB p65 on arginine 30 (R30). Finally, we found that TMAO markedly induced the expression of nicotinamide adenine dinucleotide phosphate oxidase 4 (Nox4) and production of reactive oxygen species, which contributed to PRMT5 expression and subsequent VCAM-1 expression. Collectively, our data provide novel evidence to establish a Nox4-PRMT5-VCAM-1 in mediating TMAO-induced VSMC inflammation. PRMT5 may be a potential target for the treatment of TMAO-induced vascular diseases.

Low density neutrophils are increased in patients with Beh\xe7et\u2019s disease but do not explain differences in neutrophil function

BackgroundBehçet’s disease (BD) is a multisystem autoinflammatory disease characterised by mucosal ulceration, ocular, neural, joint and skin inflammation. The cause of BD is not known but there is a strong genetic association with HLA-B*51, IL10 and IL23R. Neutrophils are a first line of defence against invading pathogens and have been described as activated in patients with BD. Neutrophils can now be separated into different subsets, such as low density (LDN) and normal density (NDN) that have diverse functional roles. We wished to address neutrophil heterogeneity in patients with BD.MethodsPeripheral blood neutrophils were obtained from 32 BD patients and 37 healthy aged-matched controls. Percoll isolation was used to isolate all neutrophils, while Ficol-Hypaque was used to obtain LDN and NDN. Phagocytic capacity and production of reactive oxygen species (ROS), and neutrophil extracellular traps (NET) stimulated with phorbol 12-myristate 13-acetate (PMA) and Escherichia coli (E.coli) were assessed in both groups.ResultsWe have demonstrated reduced phagocytic capacity and ROS production but greater NET production by total neutrophils stimulated with PMA or E.coli from BD patients in comparison with healthy controls. Patients with BD had elevated numbers of LDN and lower number of NDN compared with healthy controls. However, both neutrophil subsets showed the same reduced ROS production and phagocytic function as total neutrophils in both groups.ConclusionOur novel findings indicate that the neutrophil population in BD is heterogeneous and the increased number of LDN in combination with greater NET production may contribute to the inflammatory response and pathogenesis.

Ninjinyoeito ameliorated cigarette smoke extract-induced apoptosis and inflammation through JNK signaling inhibition in human lung fibroblasts

BackgroundCigarette smoke is a major risk factor for various lung diseases, such as chronic obstructive pulmonary disease (COPD). Ninjinyoeito (NYT), a traditional Chinese medicine, has been prescribed for patients with post-illness or post-operative weakness, fatigue, loss of appetite, rash, cold limbs, and anemia. In addition to its traditional use, NYT has been prescribed for treating frailty in gastrointestinal, respiratory, and urinary functions. Further, NYT treatment can ameliorate cigarette smoke-induced lung injury, which is a destructive index in mice; however, the detailed underlying mechanism remains unknown. The purpose of this study was to investigate whether NYT ameliorates cigarette smoke-induced cell injury and inflammation in human lung fibroblasts and determine its mechanism of action.MethodsWe prepared a cigarette smoke extract (CSE) from commercially available cigarettes to induce cell injury and inflammation in the human lung fibroblast cell line HFL1. The cells were pretreated with NYT for 24 h prior to CSE exposure. Cytotoxicity and cell viability were measured by lactate dehydrogenase (LDH) cytotoxicity assay and cell counting kit (CCK)-8. IL-8 level in the cell culture medium was measured by performing Enzyme-Linked Immuno Sorbent Assay (ELISA). To clarify the mechanisms of NYT, we used CellROX Green Reagent for reactive oxygen species (ROS) production and western blotting analysis for cell signaling.ResultsExposure of HFL1 cells to CSE for 24 h induced apoptosis and interleukin (IL)-8 release. Pretreatment with NYT inhibited apoptosis and IL-8 release. Furthermore, CSE exposure for 24 h increased the production of ROS and phosphorylation levels of p38 and JNK. Pretreatment with NYT only inhibited CSE-induced JNK phosphorylation, and not ROS production and p38 phosphorylation. These results suggest that NYT acts as a JNK-specific inhibitor.ConclusionNYT treatment ameliorated CSE-induced apoptosis and inflammation by inhibiting the JNK signaling pathway. Finally, these results suggest that NYT may be a promising therapeutic agent for patients with COPD.

The linkage between mercury-caused neuro- and genotoxicity via the inhibition of DNA repair machinery: fish brain model

Heavy metals in model conditions as well as industrial pollution launch disturbances in neural cells of different animals and human beings. The neurotoxicity of mercury, which is one of the most toxic heavy metals, has been studied for several decades. However, its low doses chronic exposure effects for neural tissue cells are still poorly understood. Therefore, the basic molecular mechanisms of mercury should be clarified. The purpose of our research is to clarify the mechanism of mercury genotoxicity, the role of the DNA repair protein apurinic/apyrimidinic endonuclease 1 (APE1) in neural tissue cells, and the response to inorganic mercury-induced neurotoxicity. In our model, we used juvenile rainbow trout exposed to mercury chloride with a range of doses 9‑36 µg/L for 60 days to study the cytotoxicity of chronic exposure. We detected the reactive oxygen species (ROS) production as an index of oxidative stress and APE1 as a marker of cellular DNA damage response in a neural cell. The ROS level was measured by using the fluorometric method based on 2',7'-dichlorofluorescein diacetate reaction. The analyses of markers of the DNA repair (APE1) and apoptosis (B cell lymphoma-2 anti-apoptotic protein – Bcl-2) were carried out with western blotting. The mercury chloride chronic exposure induced statistically significant upregulation of the ROS production in the fish brain. Contrary, the mercury low doses stimulated the downregulation of APE1 expression in the brain tissue. Furthermore, mercury chronic exposure inhibited the expression of Bcl-2 in the animals treated with 18 and 36 µg/L mercury chloride. The harmful effect of mercury could be promoted by oxidative stress generation. The downregulation of APE1 expression could lead to a lack of DNA damage response efficacy and initiate the decline in neural cell functioning. Obtained data on the APE1 expression have shown that the neurotoxic effect of mercury could be mediated, at least partially, by the decline in cellular DNA damage response in the brain. The evaluation of decrease in DNA repair response via detection of the APE1 expression can be a prospective tool to reveal the deleterious effects of toxicants in terms of their neuro- and genotoxicity.

Capecitabine Regulates HSP90AB1 Expression and Induces Apoptosis via Akt/SMARCC1/AP-1/ROS Axis in T Cells.

Transplant oncology is a newly emerging discipline integrating oncology, transplant medicine, and surgery and has brought malignancy treatment into a new era via transplantation. In this context, obtaining a drug with both immunosuppressive and antitumor effects can take into account the dual needs of preventing both transplant rejection and tumor recurrence in liver transplantation patients with malignancies. Capecitabine (CAP), a classic antitumor drug, has been shown to induce reactive oxygen species (ROS) production and apoptosis in tumor cells. Meanwhile, we have demonstrated that CAP can induce ROS production and apoptosis in T cells to exert immunosuppressive effects, but its underlying molecular mechanism is still unclear. In this study, metronomic doses of CAP were administered to normal mice by gavage, and the spleen was selected for quantitative proteomic and phosphoproteomic analysis. The results showed that CAP significantly reduced the expression of HSP90AB1 and SMARCC1 in the spleen. It was subsequently confirmed that CAP also significantly reduced the expression of HSP90AB1 and SMARCC1 and increased ROS and apoptosis levels in T cells. The results of in vitro experiments showed that HSP90AB1 knockdown resulted in a significant decrease in p-Akt, SMARCC1, p-c-Fos, and p-c-Jun expression levels and a significant increase in ROS and apoptosis levels. HSP90AB1 overexpression significantly inhibited CAP-induced T cell apoptosis by increasing the p-Akt, SMARCC1, p-c-Fos, and p-c-Jun expression levels and reducing the ROS level. In conclusion, HSP90AB1 is a key target of CAP-induced T cell apoptosis via Akt/SMARCC1/AP-1/ROS axis, which provides a novel understanding of CAP-induced T cell apoptosis and lays the experimental foundation for further exploring CAP as an immunosuppressant with antitumor effects to optimize the medication regimen for transplantation patients.

Rapid Communication: oxidative stress induced by mixed exposure to glyphosate and silver nanoparticles

ABSTRACT The aim of this study was to examine oxidative stress induced by the binary mixture of silver nanoparticles (AgNP) and glyphosate (Gly) in Daphnia magna by measurement of reactive oxygen species (ROS) production, glutathione (GSH) levels, enzyme activities of catalase (CAT) and superoxide dismutase (SOD) as well as malondialdehyde (MDA) content. Acute exposure of Daphnia magna to binary mixture of AgNP and Gly resulted in significant biochemical responses indicative of oxidative damage. This response seemed to be related to imbalance in enzymatic/non-enzymatic antioxidant enzymes associated with intracellular overproduction of ROS and significant increase in MDA levels, indicating that the integrity and function of the cell membrane was damaged. These changes adversely affected the fitness and survival of Daphnia magna and negatively influenced offspring growth and reproduction.

A Phenolic-rich Extract of Cocoa (Theobroma cacao L.) Beans Impairs the Pathogenic Properties of Porphyromonas gingivalis and Attenuates the Activation of Nuclear Factor Kappa B in a Monocyte Model.

Periodontitis, an inflammatory disease that affects tooth-supporting tissues, is the result of a polymicrobial infection involving mainly Gram negative anaerobic bacteria. The aim of the present study was to investigate the effects of a phenolic-rich extract of cocoa (Theobroma cacao L.) beans on the pathogenic properties of Porphyromonas gingivalis, which is well-known as a keystone pathogen in the development of periodontitis. The effect of the cocoa extract on P. gingivalis-induced activation of the nuclear factor kappa B (NF-κB) transcription factor in a monocyte model was also assessed. The cocoa extract, whose major phenolic compound was epicatechin, inhibited the growth, hemolytic activity, proteolytic activities, and adherence properties (basement membrane matrix, erythrocytes) of P. gingivalis in a dose-dependent manner. It also protected the barrier function of a keratinocyte model against the deleterious effects mediated by P. gingivalis, and attenuated reactive oxygen species (ROS) production by oral keratinocytes treated with P. gingivalis. Lastly, the cocoa extract showed an anti-inflammatory property by preventing P. gingivalis-induced NF-κB activation in monocytes. In conclusion, this in vitro study highlighted the potential value of an epicatechin-rich extract of cocoa beans for preventing and/or treating periodontal diseases.

The identification of alternative oxidase in intermediate host snails of Schistosoma and its potential role in protecting Oncomelania hupensis against niclosamide-induced stress

BackgroundSnail intermediate hosts are mandatory for the transmission of schistosomiasis, which has to date infected more than 200 million people worldwide. Our previous studies showed that niclosamide treatment caused the inhibition of aerobic respiration and oxidative phosphorylation, and the disruption of energy supply, in one of the intermediate hosts of schistosomiasis, Oncomelania hupensis, which eventually led to the death of the snails. Meanwhile, the terminal oxidase in the mitochondrial respiratory chain, alternative oxidase (AOX), was significantly up-regulated, which was thought to counterbalance the oxidative stress and maintain metabolic homeostasis in the snails. The aims of the present study are to identify the AOXs in several species of snails and investigate the potential activation of O. hupensis AOX (OhAOX) under niclosamide-induced stress, leading to enhanced survival of the snail when exposed to this molluscicide.MethodsThe complete complementary DNA was amplified from the AOXs of O. hupensis and three species of Biomphalaria; the sequence characteristics were analysed and the phylogenetics investigated. The dynamic expression and localisation of the AOX gene and protein in O. hupensis under niclosamide-induced stress were examined. In addition, the expression pattern of genes in the mitochondrial respiratory complex was determined and the production of reactive oxygen species (ROS) calculated. Finally, the molluscicidal effect of niclosamide was compared between snails with and without inhibition of AOX activity.ResultsAOXs containing the invertebrate AOX-specific motif NP-[YF]-XPG-[KQE] were identified from four species of snail, which phylogenetically clustered together into Gastropoda AOXs and further into Mollusca AOXs. After niclosamide treatment, the levels of OhAOX messenger RNA (mRNA) and OhAOX protein in the whole snail were 14.8 and 2.6 times those in untreated snails, respectively, but varied widely among tissues. Meanwhile, the level of cytochrome C reductase mRNA showed a significant decrease in the whole snail, and ROS production showed a significant decrease in the liver plus gonad (liver-gonad) of the snails. At 24 h post-treatment, the mortality of snails treated with 0.06–0.1 mg/L niclosamide and AOX inhibitor was 56.31–76.12% higher than that of snails treated with 0.1 mg/L niclosamide alone.ConclusionsAOX was found in all the snail intermediate hosts of Schistosoma examined here. AOX was significantly activated in O. hupensis under niclosamide-induced stress, which led to a reduction in oxidative stress in the snail. The inhibition of AOX activity in snails can dramatically enhance the molluscicidal effect of niclosamide. A potential target for the development of an environmentally safe snail control method, which acts by inhibiting the activity of AOX, was identified in this study.Graphical abstract

LSEA Evaluation of Lipid Mediators of Inflammation in Lung and Cortex of Mice Exposed to Diesel Air Pollution.

Airborne ultrafine particle (UFP) exposure is a great concern as they have been correlated to increased cardiovascular mortality, neurodegenerative diseases and morbidity in occupational and environmental settings. The ultrafine components of diesel exhaust particles (DEPs) represent about 25% of the emission mass; these particles have a great surface area and consequently high capacity to adsorb toxic molecules, then transported throughout the body. Previous in-vivo studies indicated that DEP exposure increases pro- and antioxidant protein levels and activates inflammatory response both in respiratory and cardiovascular systems. In cells, DEPs can cause additional reactive oxygen species (ROS) production, which attacks surrounding molecules, such as lipids. The cell membrane provides lipid mediators (LMs) that modulate cell-cell communication, inflammation, and resolution processes, suggesting the importance of understanding lipid modifications induced by DEPs. In this study, with a lipidomic approach, we evaluated in the mouse lung and cortex how DEP acute and subacute treatments impact polyunsaturated fatty acid-derived LMs. To analyze the data, we designed an ad hoc bioinformatic pipeline to evaluate the functional enrichment of lipid sets belonging to the specific biological processes (Lipid Set Enrichment Analysis-LSEA). Moreover, the data obtained correlate tissue LMs and proteins associated with inflammatory process (COX-2, MPO), oxidative stress (HO-1, iNOS, and Hsp70), involved in the activation of many xenobiotics as well as PAH metabolism (Cyp1B1), suggesting a crucial role of lipids in the process of DEP-induced tissue damage.

TSLP regulates mitochondrial ROS-induced mitophagy via histone modification in human monocytes

BackgroundThymic stromal lymphopoietin (TSLP) is a Th2-like cytokine involved in asthma pathogenesis. Excessive reactive oxygen species (ROS) production can lead to airway inflammation, hyperresponsiveness and remodeling. Mitophagy, followed by ROS production, is the selective degradation of mitochondria by autophagy and often occurs in defective mitochondria. In the present study, we aimed to examine the effects of TSLP on ROS production and mitophagy in human monocytes and to investigate the underlying mechanisms, including epigenetic regulation.ResultsTSLP induced ROS generation, and the effects were reversed by the antioxidant N-acetylcysteine (NAC) in THP-1 cells. Transmission electron microscopy images showed donut-shaped mitochondria that lost the cristae ultrastructure after TSLP stimulation. A decrease in mitochondrial membrane potential, decreased MTCO2 expression, and increased mitochondrial DNA release after TSLP stimulation were found. TSLP enhanced mitochondrial complex I and complex II/III activity and increased mitochondrial copy numbers and the expression of the complex II SHDA gene. TSLP-induced SHDA expression was inhibited by the histone acetyltransferase inhibitor anacardic acid (AA) and the histone methyltransferase inhibitor methylthioadenosine (MTA), and chromatin immunoprecipitation assays revealed that TSLP enhanced H3 acetylation, H4 acetylation, and H3K4 and H3K36 trimethylation in the SHDA promoter. Confocal laser microscopy showed that TSLP treatment increased the signals of the mitophagy-related proteins PINK1, LC3, phospho-parkin and phospho-ubiquitin, and pretreatment with AA and MTA reduced TSLP-induced PINK1 and LC3 accumulation in mitochondria. Western blot analysis showed that TSLP significantly increased phosphor-AMPK signal intensity, and the effects were inhibited by the antioxidant NAC. The increased signal intensities of the mitophagy-related proteins PINK1, Parkin and LC3 I/II were decreased by dorsomorphin, an AMPK inhibitor. TSLP decreased M1-related cytokine CXCL-10 production and increased M2-related cytokine CCL-1 and CCL-22 production, which was suppressed by the mitophagy inhibitor Mdivi-1 and PINK1 gene knockdown.ConclusionsEpithelial-derived TSLP regulates ROS production and mitophagy through AMPK activation and histone modification and alters M1/M2 chemokine expression in human monocytes.Graphical