Decreased Reactive Oxygen Species Production Research Articles

MP01-09 LUTEOLIN SUPPRESSES SQUAMOUS DIFFERENTIATION OF BLADDER CANCER AND CANCER GROWTH VIA REGULATION OF MAMMALIAN TARGET OF RAPAMYCIN PATHWAY

You have accessJournal of UrologyBladder Cancer: Basic Research & Pathophysiology I (MP01)1 Apr 2020MP01-09 LUTEOLIN SUPPRESSES SQUAMOUS DIFFERENTIATION OF BLADDER CANCER AND CANCER GROWTH VIA REGULATION OF MAMMALIAN TARGET OF RAPAMYCIN PATHWAY Keitaro Iida*, Taku Naiki, Aya Naiki-Ito, Takashi Nagai, Satoshi Nozaki, Toshiki Etani, Ryosuke Ando, Noriyasu Kawai, and Takahiro Yasui Keitaro Iida*Keitaro Iida* More articles by this author , Taku NaikiTaku Naiki More articles by this author , Aya Naiki-ItoAya Naiki-Ito More articles by this author , Takashi NagaiTakashi Nagai More articles by this author , Satoshi NozakiSatoshi Nozaki More articles by this author , Toshiki EtaniToshiki Etani More articles by this author , Ryosuke AndoRyosuke Ando More articles by this author , Noriyasu KawaiNoriyasu Kawai More articles by this author , and Takahiro YasuiTakahiro Yasui More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000000815.09AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Luteolin is a natural flavonoid with strong antioxidative properties. The anti-cancer effect of luteolin in several cancers has been reported; however, little is known about its effect on bladder cancer. Here, we explored the effects of luteolin on bladder cancer. METHODS: Human urothelial carcinoma cell lines, T24 and 5637, were used. A WST-8 assay and western blotting were used to evaluate cell viability and protein signaling, respectively. Thioredoxin activity and reactive oxygen species (ROS) production were evaluated using thioredoxin and dichlorodihydrofluorescein diacetate assays, respectively. Furthermore, we examined the impact of a 20-week luteolin-rich diet on the growth of N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN)–induced bladder cancer in a rat model (luteolin concentrations were control, 20 ppm and 100 ppm; n=20, respectively). RESULTS: Luteolin induced a dose-dependent reduction in the number of viable cells; it also increased thioredoxin activity and decreased ROS production. Luteolin downregulated phospho-p70S6K and phospho-S6K (pS6), substrates of mammalian target of rapamycin (mTOR), which was reversed by the thioredoxin inhibitor, PX-12. This indicates luteolin inhibited the mTOR pathway by regulating thioredoxin and ROS. In an in vivo study, BBN-induced rat bladder cancer was inhibited by the oral administration of luteolin; the Ki67 labeling index and pS6 expression were also decreased. Further, both plasma and urine luteolin-3'-O-glucuronide concentrations were strongly associated with the Ki67 labeling index (r=0.31, -0.41, respectively) and the pS6 expression (r=-0.60, -0.62, respectively). Moreover, a significant decrease in the squamous differentiation of bladder cancer was attributed to plasma luteolin-3'-O-glucuronide concentrations (p<0.01). CONCLUSIONS: Luteolin may represent another natural product–derived therapeutic agent that acts against bladder cancer by up-regulating thioredoxin activity and inhibiting mTOR signaling. Source of Funding: None © 2020 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 203Issue Supplement 4April 2020Page: e5-e5 Advertisement Copyright & Permissions© 2020 by American Urological Association Education and Research, Inc.MetricsAuthor Information Keitaro Iida* More articles by this author Taku Naiki More articles by this author Aya Naiki-Ito More articles by this author Takashi Nagai More articles by this author Satoshi Nozaki More articles by this author Toshiki Etani More articles by this author Ryosuke Ando More articles by this author Noriyasu Kawai More articles by this author Takahiro Yasui More articles by this author Expand All Advertisement PDF downloadLoading ...

Neuroprotective Potential of Dithiolethiones D3T And ACDT Against Iron Overload‐Induced Toxicity in Human Glioblastoma Cells

The redox potential of iron plays a dual role in which it serves as a vital co‐factor for numerous biological processes, but also catalyzes the production of reactive oxygen species (ROS) that can damage intracellular biomolecules. There is growing evidence of the involvement of iron overload‐induced oxidative stress in the pathogenesis of several neurodegenerative diseases. Various free radical scavengers and antioxidants such as N‐acetylcysteine (NAC) have shown some degree of neuroprotection against iron‐induced oxidative stress. Dithiolethiones 3H‐1,2‐dithiole‐3‐thione (D3T) and 5‐amino‐3‐thioxo‐3H‐(1,2) dithiole‐4‐carboxylic acid ethyl ester (ACDT) are organosulfur compounds that are known to induce production of the cellular antioxidant glutathione (GSH) and other phase‐II metabolic enzymes via activation of the Nrf2 transcription pathway. The present study was aimed to determine the neuroprotective ability of D3T and ACDT against iron overload‐mediated cellular toxicity in U‐87 MG human glioblastoma cells. Cells were exposed to an iron salt ferric ammonium citrate (FAC) for 24 hours with or without being pre‐treated with D3T or ACDT. The cells exposed to FAC alone showed significant decrease in cell viability in a concentration‐dependent manner as assessed using the CellTiter‐Glo® Assay. FAC exposure also depleted the levels of reduced form of GSH and significantly increased ROS generation, as determined by the GSH/GSSG‐GloTM Gluathione Assay and the Cellular ROS Assay kits respectively. Pre‐treatment with 50 μM of D3T or ACDT exhibited significant neuroprotective effects demonstrated by an increase in cell viability, increase in reduced GSH levels, and decrease in ROS production, all depicting a strong counteractive potential against iron overload‐induced neurotoxicity. In conclusion, these results indicate that both D3T and ACDT have neuroprotective ability against iron overload toxicity, the first such study in glial cells. Promisingly, the neuroprotective effects of these dithiolethiones were found to be higher than the positive control NAC. Further studies are currently underway to evaluate the effects of these dithiolethiones on specific cell death pathways induced by iron overload.

Vascular endothelial growth factor alleviates mitochondrial dysfunction and suppression of mitochondrial biogenesis in models of Alzheimer’s disease

Purpose Mitochondrial dysfunction is a prominent feature of Alzheimer’s disease (AD). As vascular endothelial growth factor (VEGF) has been shown to be protective in AD, the aim of this study was to investigate the effects of VEGF on mitochondrial function in models of AD. Materials and methods Adeno associated virus (AAV)-VEGF was injected into the hippocampus of APP/PS1 mice. Cognitive function was assessed in these mice with use of the Morris water maze (MWM) and β-amyloid (Aβ) levels in the hippocampus were also measured. Cell viability and reactive oxygen species (ROS) levels were determined in the SH-SY5Y cells treated with Aβ25–35 which served as a cell model of AD. Transmission electron microscopy (TEM) was used to evaluate structural changes in mitochondria and mitochondrial DNA (mtDNA) copy number and mitochondrial membrane potential (MMP) were also recorded. Finally, we investigated the effects of VEGF upon mitochondrial biogenesis, autophagy and mitochondrial autophagy (mitophagy) as determined both in vivo and in vitro with western blots. Results VEGF treated mice showed improvements in spatial learning and memory along with reduced Aβ levels. VEGF protected SH-SY5Y cells against Aβ25–35 induced neurotoxicity as demonstrated by increased cell viability and decreased ROS production. Associated with these effects were improvements in mitochondrial structure and function, and increased numbers of mitochondria resulting from stimulation of mitochondrial biogenesis. Conclusions VEGF alleviates Aβ related patholoy in models of AD. In part, these beneficial effects of VEGF result from protection of mitochondria and stimulation of mitochondrial biogenesis.

Autophagy drives fibroblast senescence through MTORC2 regulation

ABSTRACT Sustained macroautophagy/autophagy favors the differentiation of fibroblasts into myofibroblasts. Cellular senescence, another means of responding to long-term cellular stress, has also been linked to myofibroblast differentiation and fibrosis. Here, we evaluate the relationship between senescence and myofibroblast differentiation in the context of sustained autophagy. We analyzed markers of cell cycle arrest/senescence in fibroblasts in vitro, where autophagy was triggered by serum starvation (SS). Autophagic fibroblasts expressed the senescence biomarkers CDKN1A/p21 and CDKN2A/p16 and exhibited increased senescence-associated GLB1/beta-galactosidase activity. Inhibition of autophagy in serum-starved fibroblasts with 3-methyladenine, LY294002, or ATG7 (autophagy related 7) silencing prevented the expression of senescence-associated markers. Similarly, suppressing MTORC2 activation using rapamycin or by silencing RICTOR also prevented senescence hallmarks. Immunofluorescence microscopy showed that senescence and myofibroblast differentiation were induced in different cells, suggesting mutually exclusive activation of senescence and myofibroblast differentiation. Reactive oxygen species (ROS) are known inducers of senescence and exposing fibroblasts to ROS scavengers decreased ROS production during SS, inhibited autophagy, and significantly reduced the expression of senescence and myofibroblast differentiation markers. ROS scavengers also curbed the AKT1 phosphorylation at Ser473, an MTORC2 target, establishing the importance of ROS in fueling MTORC2 activation. Inhibition of senescence by shRNA to TP53/p53 and shRNA CDKN2A/p16 increased myofibroblast differentiation, suggesting a negative feedback loop of senescence on autophagy-induced myofibroblast differentiation. Collectively, our results identify ROS as central inducers of MTORC2 activation during chronic autophagy, which in turn fuels senescence activation and myofibroblast differentiation in distinct cellular subpopulations. Abbreviations: 3-MA: 3-methyladenine; ACTA2: actin, alpha 2, smooth muscle, aorta; AKT1: AKT serine/threonine kinase 1; p-AKT1: AKT1 Ser473 phosphorylation; t-AKT1: total AKT serine/threonine kinase 1; ATG4A: autophagy related 4A cysteine peptidase; ATG7: autophagy gene 7; C12FDG: 5-dodecanoylaminofluorescein Di-β-D-Galactopyranoside; CDKN1A: cyclin dependent kinase inhibitor 1A; CDKN2A: cyclin dependent kinase inhibitor 2A; Ctl: control; DAPI: 4ʹ,6-diamidino-2-phenylindole, dilactate; ECM: extracellular matrix; GSH: L-glutathione reduced; H2O2: hydrogen peroxide; HLF: adult human lung fibroblasts; Ho: Hoechst 33342 (2′‐[4‐ethoxyphenyl]‐5‐[4‐methyl‐1‐piperazinyl]‐2.5′‐bi‐1H‐benzimidazole); HSC: hepatic stellate cells; LY: LY294002; MAP1LC3B/LC3B: microtubule-associated protein 1 light chain 3 beta; MTORC1/2: mechanistic target of rapamycin kinase complex 1/2; N: normal growth medium; NAC: N-acetyl-L-cysteine; PBS: phosphate-buffered saline; PDGFA: platelet derived growth factor subunit A; PRKCA/PKCα: protein kinase C alpha; PtdIns3K: class III phosphatidylinositol 3-kinase; PTEN: phosphatase and tensin homolog; R: rapamycin; RICTOR: RPTOR independent companion of MTOR complex 2; ROS: reactive oxygen species; RPTOR: regulatory associated protein of MTOR complex 1; SA-GLB1/β-gal: senescence-associated galactosidase beta 1; SGK1: serum/glucocorticoid regulated kinase 1; shRNA: short hairpin RNA; siCtl: control siRNA; siRNA: small interfering RNA; SQSTM1: sequestosome 1; SS: serum-free (serum starvation) medium; TP53: tumor protein p53; TUBA: tubulin alpha; V: vehicle.

Coffee beverage reduces ROS production and does not affect the organism s response against Candida albicans

Coffee is a mixture of substances with potential beneficial and adverse health effects. Several studies demonstrate the antioxidant effect of the phenolics compounds present in coffee. Neutrophils produce reactive oxygen species (ROS) by activating NOX2, which plays a key role in organism defense against microbial pathogens. Diabetes mellitus patients are more susceptible to bacterial and fungal infections. The present study evaluated the influence of coffee beverage on NOX2 activity and ROS generation and the impact of this effect on phagocytosis and killing of Candida albicans by neutrophils from diabetic and non-diabetic animals. Diabetes was induced in male Wistar rats using 2% alloxan. Diabetic and non-diabetic animals were divided into groups treated and untreated with coffee drink (7.2 mL/kg/day) or apocyanine (16 mg/kg/day) for 50 days. After 50 days, the animals' glycemic profile was measured by blood glucose and HbA1c tests. The generation of ROS in neutrophilic cells was measured by chemiluminescence and cytochrome C reduction assays. C. albicans phagocytosis and death were evaluated by optical microscopy using the May-Grunwald-Giemsa staining method. The coffee drink has not altered the glycemic profile and NOX2 activity of the animals. However, coffee reduced the ROS pool in non-diabetic and diabetic animals, but this activity did not harm the phagocytosis or killing of neutrophils. Treatment with apocyanin decreased ROS production and killing capacity of neutrophils from non-diabetic animals against C. albicans. We suggest that the coffee drink intake prevents oxidative damage and does not impair response of the organism against opportunistic microorganism.

Gill filament permeabilization: A novel approach to assess mitochondrial function in sheepshead minnows (Cyprinodon variegatus) following anthraquinone exposure

Anthracene is a highly toxic polycyclic aromatic hydrocarbon (PAH), and its toxicity is increased 8-fold after compounding exposure to UV radiation. Exposure to either the parent or photo-modified compound has been shown to cause increases in reactive oxygen species (ROS) production and lipid peroxidation. Since the majority of ROS production occurs within mitochondria, we investigated simultaneous mitochondrial respiration and ROS production in the gills of sheepshead minnows (Cyprinodon variegatus) acutely (48 h) exposed to anthraquinone (40 μg l−1). Anthraquinone exposure caused a 25% increase in oxidative phosphorylation with electrons donated to Complex I (OXPHOSCI) and a 33% increase in Leak respiration with oligomycin (Leak-OmyCI). ROS production was slightly increased (33.3%) in Leak state with oligomyocin respiring on Complex I substrates (Leak-OmyCI) after anthraquinone exposure, but this value remained unchanged in all other respiratory states. When ROS production was normalized to mitochondrial oxygen consumption, we found that ROS production was decreased in all respiratory states, but most noticeably in the Leak state. We speculate that differences in the antioxidant defense system may have played a role in decreased ROS production. Overall, in this paper we present a novel technique to measure mitochondrial function in the gill filaments of teleost fish exposed to xenobiotic molecules, and we show anthraquinone exposure alters aspects of oxidative phosphorylation and ROS production.

Oxidative stress: Noradrenaline as an integrator of responses in the neuroendocrine and immune systems of the ascidian Phallusia nigra

Neurotransmitters play key roles in regulating the homeostasis of organisms in stressful environments. Noradrenaline (NA) is the main neurotransmitter known to modulate immunological parameters, and is important in the crosstalk between the neuroendocrine and immune systems. In this study, using the ascidian Phallusia nigra, we analyzed the level of catecholamines (CA) in the plasma after mechanical stress, and the effect of NA on the oxidative stress (OS) displayed by immune cells. We measured the concentration of reactive oxygen species (ROS), and analyzed whether α- and/or β-adrenoreceptors (ARs) are involved in ROS modulation, lipid peroxidation (LPO), antioxidant capacity against peroxyl radicals (ACAP), and activity of the enzymes catalase (CAT) and glutathione S transferase (GST) in immune cells after incubation with different concentrations of NA, with or without zymosan (ZnA) challenge. The results showed that NA reduced ROS production, even in immune cells challenged with ZnA, and that this modulation occurred through α1-and β1-ARs. ACAP levels showed different responses, depending on whether immune cells were challenged or not with ZnA, and also depending on the NA concentration: 1.0 μM NA increased ACAP levels, but 10.0 μM reduced ACAP levels. NA enhanced the activity of CAT and GST in ZnA-challenged and non-challenged immune cells, while 1.0 and 10.0 μM NA effectively reduced LPO. Taken together, these results show that NA can protect cells from ROS damage, decreasing ROS production and LPO, and enhancing ACAP as well as the activity of CAT and GST. The approach used here with this model contributes to understanding the relationship between the neuroendocrine and immune systems, revealing new effects of NA on OS regulation in ascidians.

P38-Mediated Cellular Senescence in Conjunctivochalasis Fibroblasts.

Conjunctivochalasis (CCH) is a common ocular disease and has received extensive attention recently. However, its exact pathogenesis remains largely unknown. Owing to the high morbidity of CCH in older people, this study aimed to investigate whether cellular senescence contributes to CCH progression and the underlying mechanism. Loose conjunctival tissues from CCH patients (n = 13) and normal conjunctival tissues from age-matched persons (n = 12) were obtained and the fibroblasts were separately induced and obtained. Cellular senescence, and the expression of senescence-associated genes (p53 and p21) and p38 in CCH conjunctival tissues and normal controls, were determined by senescence-associated β-galactosidase (SA-β-Gal) staining and quantitative (q)RT-PCR, respectively. To explore the effects of p38 on cellular senescence in CCH fibroblasts, small interfering RNA (siRNA) targeting p38 (siP38) and p38-specific inhibitor SB203580 was performed in CCH fibroblasts. Then, cellular senescence, cell viability, reactive oxygen species (ROS) production, and gene expression were detected according to the corresponding methods. CCH conjunctival tissues had significantly more senescent cells, evidenced by more SA-β-Gal-positive cells, and higher expression of senescence-associated genes (p53 and p21) and p38. CCH fibroblasts transfected with siP38 or treated with SB203580 had obviously reduced numbers of senescent cells, decreased ROS production, and increased cell viability, as well as reduced expression of senescence-associated genes. Meanwhile, blocking p38 signaling decreased the expression of p53 and p21. Therefore, these findings indicate that cellular senescence might be a causative factor for CCH. P38 signaling might play an important role in the progress of cellular senescence in CCH fibroblasts via manipulation of p53/p21 signaling.

Effects of Resveratrol, Berberine and Their Combinations on Reactive Oxygen Species, Survival and Apoptosis in Human Squamous Carcinoma (SCC-25) Cells.

Levels of cellular Reactive Oxygen Species (ROS) influence the oxidized/reduced states of cellular proteins, and create redox-signaling pathways that can activate transcription factors, kinases, and phosphatases. ROS levels can be increased radically by external factors, including ionizing and UV radiation or exposure to chemical compounds. These increased ROS levels can, in turn, lead to oxidative damage of DNA. Natural plant treatments against cancer can modulate these processes by inducing or decreasing ROS production. Here we report new observations that squamous carcinoma (SCC-25) cells, exposed to 24 hours of combined resveratrol and berberine treatment, contain increased ROS levels. Using flow cytometry, for drug activity characteristics, an accumulation of ROS was observed. A combination of different dyes, CellROX Green (Life Technologies) and DCFH-DA (Sigma), allowed for flow cytometric estimation of levels of cellular ROS as well as cellular localization. Live staining and microscopic observations confirmed the accumulation of ROS in SCC-25 cells following a combination treatment at concentrations of 10μg/ml. Additionally, the cytotoxicity of the compounds was significantly improved after their combined application. Additive effects were observed for doses lower than the calculated IC50 of berberine [IC50=23µg/ml] and resveratrol [IC50=9µg/ml]. Viability (MTS) assays and analysis of isobolograms revealed a significant impact on cell viability upon combination treatment. These results suggest that administration of berberine, in the presence of resveratrol, could be decreased even to 50% (half the IC50 for berberine) for cancer treatment.

The Chromatin Remodeler Brg1 Integrates ROS Production and Endothelial-Mesenchymal Transition to Promote Liver Fibrosis in Mice.

Trans-differentiation of endothelial cells to myofibroblast contributes to liver fibrosis. Reactive oxygen species (ROS) plays a key role in endothelial-mesenchymal transition (EndMT) although the underlying epigenetic mechanism is unclear. Here we report that endothelial conditional knockout of Brg1, a chromatin remodeling protein, attenuated liver fibrosis in mice. Brg1 deficiency in endothelial cells was paralleled by a decrease in ROS production and blockade of EndMT both in vivo and in vitro. The ability of BRG1 to regulate ROS production and EndMT was abolished by NOX4 depletion or inhibition. Further analysis revealed that BRG1 interacted with SMAD3 and AP-1 to mediate TGF-β induced NOX4 transcription in endothelial cells. Mechanistically, BRG1 recruited various histone modifying enzymes to alter the chromatin structure surrounding the NOX4 locus thereby activating its transcription. In conclusion, our data uncover a novel epigenetic mechanism that links NOX4-dependent ROS production to EndMT and liver fibrosis. Targeting the BRG1-NOX4 axis may yield novel therapeutics against liver fibrosis.

Modulation of Adipogenesis and Oxidative Status by Quercetin and Ochratoxin A: Positive or Negative Impact on Rat Adipocyte Metabolism?

(1) Background: Impaired adipose tissue function leads to the development of metabolic disorders. Reactive oxygen species play a key role in the regulation of adipogenesis and insulin-stimulated glucose uptake by adipocytes. Quercetin (QCT) regulates adipogenesis by affecting the redox state of preadipocytes. Ochratoxin A (OTA) is one of the most prevalent mycotoxins contaminating food. It has cytotoxic, genotoxic, pro-inflammatory, and anti-adipogenic effects. Antioxidants are believed to protect cells from the cytotoxicity and genotoxicity induced by OTA. The aim of this study was to investigate the effect of QCT and OTA application on preadipocyte differentiation, oxidative status, and adipocyte metabolism. (2) Methods: Primary rat preadipocytes were isolated from subcutaneous adipose tissue of Wistar rats. Gene expressions were determined by qPCR. Cell viability, reactive oxygen species (ROS) production, glucose uptake, and lipid accumulation were determined using commercially available kits. (3) Results: A dose-dependent inhibitory effect of QCT on adipogenic differentiation was observed, which was accompanied by a decrease in ROS production. Reduced ROS formation is closely related to impaired glucose uptake by adipocytes. (4) Conclusions: The results of this study indicate a key role of ROS in regulating adipogenesis and metabolic pathways, which is affected by the application of QCT and/or OTA.

In Vitro Anti-Inflammatory and Immunomodulatory Activities of an Extract from the Roots of Bupleurum rotundifolium

Background: Some Bupleurum species, such as the Bupleurum chinense DC. or the Bupleurum scorzonerifolium Willd have been extensively studied (especially their roots) for the treatment of inflammation. In contrast, only compounds extracted from the aerial parts of Bupleurum rotundifolium have been studied and showed anti-inflammatory or antiproliferative activities. This study was conducted to investigate the antioxidant, anti-inflammatory, and immunomodulatory effects of Bupleurum rotundifolium roots. Methods: To tackle the various aspects of inflammation, we studied in vitro a methanolic extract from the roots of Bupleurum rotundifolium on peripheral blood mononuclear cells (PBMCs), polymorphonuclear neutrophils (PMNs), and the monocytic cells THP-1. Its antioxidant capacities and iron-chelating activity were assessed. The extract was tested on THP-1 differentiation, reactive oxygen species (ROS) production by leukocytes, neutrophils chemotaxis, cytokines, PGE2 production, and NF-κB activation in PBMCs. Results: The extract showed a decreased ROS production in stimulated cells. It increased PBMC chemokine secretion and up-regulated the differentiation of THP-1 monocytes into macrophage-like cells, indicating a potential interest of the extract in the resolution of acute inflammation. In addition, the analysis of cytokine production suggests that Bupleurum rotundifolium has immunomodulatory properties. Conclusions: Cytokines secretion, especially IL-1β and IL-12p70, provided us with a set of indicators suggesting that the extract might be able to drive the polarization of macrophages and lymphocytes toward a Th2 anti-inflammatory profile in excessive inflammation.

Zinc mediates resuscitation of lactic acid-injured Escherichia coli by relieving oxidative stress.

Lactic acid is a natural antimicrobial in food industry, and also exists in fermented food. It was reported that sublethally injured Escherichia coli could survive in acidic conditions. When conditions become advantageous, injured E. coli can restore physiological function, which is a potential threat in food industry. Recovery is a necessary step for discriminating injured bacteria, but the resuscitation mechanism of injured bacteria is still unknown. In our study, sublethal lactic acid treatment (pH 4·2, 60min) posed oxidative stress on E. coli by decrease of superoxide dismutase (SOD) activity and overproduction of reactive oxygen species (ROS). Zinc with low concentration (1·0mmoll-1 ) significantly increased the recovery ratio of injured E.coli induced by lactic acid. The recovery ratios of injured cell in minimal A medium (minA) with 1·0mmoll-1 zinc reached to that with 3·0mmoll-1 catalase (CAT). Conversely, the addition of zinc chelator N, N, N', N'-tetrakis (2-pyridylmethyl) decreased the recovery ratio. Zinc accelerated resuscitation of injured E. coli by improving SOD activity, and decreasing ROS production. Deletion of sodC encoding Cu/ZnSOD, katE/katG encoding CAT or regulating gene rpoS significantly decreased the recovery ratio. Among all of the mutants in this study, ΔrpoS and ΔsodC showed the lowest recovery ratio, which means they played significant roles in the process of resuscitation. We provided direct evidence that zinc mediated resuscitation of lactic acid-injured E. coli by relieving oxidative stress. Zinc can be used as a low-cost and effective agent to improve recovery ratio and detection efficiency of injured bacteria. Antibacterial agents are a challenge for bacteria, but bacteria can survive as a sublethally injured state under stresses. Using injured E. coli induced by lactic acid as a model organism, we validated the significant role of zinc on resuscitation of injured cells.

P720Atheroprotective effects of 17beta-estradiol are mediated by PPARgamma in human coronary artery smooth muscle cells

Abstract Background 17β-estradiol (E2) mediates vasculoprotection in various preclinical and clinical models of atherosclerosis and neointimal hyperplasia. However, the molecular mechanisms underlying these effects are still not fully elucidated. Previous studies have demonstrated the essential role of the peroxisome-proliferator-activated-receptor-γ (PPARγ) in mediating vasculoprotective effects of E2 in vivo. The aim of the current study was to investigate whether PPARγ is implicated in mediating vasculoprotective mechanisms of E2 in human coronary artery smooth muscle cells (HCASMC). Methods Primary HCASMC were purchased and stimulated with E2 [10 nM], the selective estrogen receptor α (ERα) agonist propylpyrazole triol (PPT) [50 nM] and the selective ERα antagonist methyl-piperidino-pyrazole (MPP) [1 μM], respectively. Changes in PPARγ mRNA and protein expression upon stimulation of ERα were assessed by qPCR and Western blot analyses. Nuclear PPARγ protein expression and DNA binding affinity was assessed after the isolation of the nuclear protein fraction. Hereafter, HCASMC were incubated with E2, PPARγ-antagonist GW9662 [1 μM – 30 μM], or both. HCASMC proliferation was assessed by nuclear BrdU staining and reactive oxygen species (ROS) formation was assessed by L-012- and DCF-DA assays. Results E2 significantly increased PPARγ expression in HCASMC (1.95±0.41 –fold; n=5; p=0.0335). This effect was mimicked by ERα agonist PPT (1.63±0.27 –fold; n=7; p=0.0489) and was abrogated by co-incubation with ERα antagonist MPP (1.17±0.18 –fold; n=3; pvs. control &gt;0.05). Nuclear PPARγ expression was enhanced by E2 (1.53±0.16 –fold; n=4; pvs. control = 0.0074; Fig. 2A) whereas PPARγ's DNA binding activity to PPRE remained unchanged upon stimulation with E2 (0.94±0.11 –fold; n=4; pvs. control &gt;0.05). Pharmacological inhibition of PI3K/Akt by LY294002 abrogated E2-induced expression of PPARγ (0.24±0.09 –fold; n=3; pvs. E2 = 0.0017), arguing for a PI3K/Akt-dependent activation by E2. The role of PPARγ in mediating vasculoprotective effects of E2 was assessed in functional assays using PPARγ-antagonist GW9662. E2 diminished HCASMC proliferation which was restored by GW9662. While E2 only slightly decreased ROS production by HCASMC, GW9662 significantly increased ROS levels (1,036±169 RLU x s–1 x cell–1 versus 561±99 RLU x s–1 x cell–1; n=5–6; p=0.0287). Conclusion In summary, the present study identifies PPARγ as a downstream mediator of E2-related atheroprotective effects in HCASMC. 17β-estradiol regulates vascular PPARγ-expression in HCASMC via the ERα receptor and the PI3K/Akt pathway. PPARγ agonism might be a promising therapeutic strategy to prevent cardiovascular events in postmenopausal women with depleted E2 plasma levels. Acknowledgement/Funding This work was supported by the Bonfor program of the University of Bonn [grant number O-109.0057 to JJ].

Effects of LncRNA SNHG15 on Osteogenic/Adipogenic Differentiation of Bone Marrow Mesenchymal Stem Cells Under Oxidative Stress by TGFβ/Smad Signaling Pathway

Oxidative stress can affect bone marrow mesenchymal stem cells (BMSCs). LncRNA SNHG15 involves in a variety of cellular physiological and pathological processes. However, LncRNA SNHG15’s effect on osteogenesis/adipogenic differentiation of BMSCs under oxidative stress remains unclear. BMSCs were divided into normal control group; oxidative stress group; SNHG15 group in which SNHG15 plasmid was transfected under oxidative stress condition followed by analysis of the expression of LncRNA SNHG15, RUNX2 and OPN by real-time quantitative PCR, reactive oxygen species (ROS) and superoxide dismutase (SOD) activity, FABP4 and PPARγ2 mRNA expression, alkaline phosphatase (ALP) activity and TGFβ/Smad signaling by Western blot. Under oxidative stress, the expression of SHHG15, RUNX2 and OPN mRNA was significantly decreased, ROS production was increased, SOD activity was reduced, along with increased expression of FABP4 and PPARγ2 protein, decreased ALP activity, as well as reduced expression of TGFβ1, Smad2, and Smad7 compared to control group (P &lt; 0.05). Transfection of LncRNA SNHG15 plasmid significantly up-regulated the expression of SNHG15, RUNX2 and OPN mRNA, decreased ROS production, increased SOD activity, decreased expression of FABP4 and PPARγ2 mRNA, and increased ALP activity as well as increased expression of TGFβ1, Smad2, and Smad7 compared to control group (P &lt; 0.05). The expression of SNHG15 is decreased in BMSCs under oxidative stress. Up-regulation of SNHG15 expression can improve the redox balance through TGFβ/Smad signaling pathway, promote osteogenic differentiation of BMSCs under oxidative stress, and inhibit its differentiation into fat.

Drugs to Inhibit the NLRP3 Inflammasome: Not Always On Target.

Drugs to Inhibit the NLRP3 Inflammasome: Not Always On Target.

The Neuroprotective Effect of the Adiponectin Receptor Agonist AdipoRon on Glutamate-Induced Cell Death in Rat Primary Retinal Ganglion Cells.

Purpose: To determine whether the adiponectin receptor (AdipoR) agonist AdipoRon inhibits glutamate-induced neuronal cell death and to investigate the neuroprotective mechanism of AdipoRon in rat primary retinal ganglion cells (RGCs). Methods: The expression pattern of AdipoR1 and AdipoR2 in rat retina and primary RGCs was examined by immunostaining. The neuroprotective effect of AdipoRon on glutamate-induced cell death was evaluated in rat primary RGCs. Cellular levels of reactive oxygen species (ROS) were also measured. Peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α), estrogen-related receptor-α (Esrra), mitochondrial transcription factor A (TFAM), peroxisome proliferator-activated receptor α (PPARα), and catalase mRNA levels were examined. Results: The expression of AdipoR1 and AdipoR2 was confirmed in rat retina and primary RGCs. AdipoRon significantly increased the survival rate of glutamate-induced cell death and decreased ROS production. Additionally, the mRNA levels of PGC-1α, Esrra, and TFAM were upregulated by AdipoRon. Conclusions: These results suggest that AdipoRon has a neuroprotective effect by inhibiting ROS production via upregulation of PGC-1α, Esrra, and TFAM against glutamate-induced RGC death.

Quercetin protects human granulosa cells against oxidative stress via thioredoxin system

Granulosa Cells (GCs) are sensitive to excessive production of reactive oxygen species (ROS). Quercetin (QUR) is a free radical scavenger which can alleviate oxidative stress through nuclear factor (erythroid-derived 2)-like 2 (Nrf2)/antioxidant response element (ARE) pathway and thioredoxin (Trx) system. We aimed to explore the probable protective role of QUR on cultured human GCs treated with hydrogen peroxide (H2O2) as an inducer of oxidative stress. MTT assay was applied for evaluating the cell cytotoxicity of QUR and H2O2. The rate of apoptotic cells and intracellular ROS generation were determined by Annexin V-FITC/PI staining and 2′-7′-dichlorodihydrofluorescein diacetate fluorescent probes (DCFH-DA), respectively. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis and western blot analysis were used to evaluate the gene and protein expression of Nrf2 and kelch-like ech-associated protein 1 (Keap1)1. The Nrf2 and Trx activities were measured by Enzyme-linked Immunosorbent Assay (ELISA). The results indicated that QUR pretreatment can decrease ROS production and apoptosis induced by H2O2. In addition, QUR increased Nrf2 gene and protein expression, as well as its nuclear translocation. Moreover, in QUR-treated group, a lower level of Keap1 protein was observed, which was not reported as significant. The results also indicated a significant correlation between the expression of Nrf2 and Keap1 in QUR-treated group. Further, QUR protected GCs from oxidative stress by increasing Trx gene expression and activity. This study suggests that QUR as a supplementary factor may protect GCs from oxidative stress in diseases related to this condition.

Characterization of phenolic compounds from Eugenia supra-axillaris leaf extract using HPLC-PDA-MS/MS and its antioxidant, anti-inflammatory, antipyretic and pain killing activities in vivo

Reactive oxygen species (ROS) are involved in the pathophysiology of several health disorders, among others inflammation. Polyphenols may modulate ROS related disorders. In this work, thirty-two phenolic compounds were tentatively identified in a leaf extract from Eugenia supra-axillaris Spring. ex Mart. using HPLC-MS/MS, five of which were also individually isolated and identified. The extract displayed a substantial in vitro antioxidant potential and was capable of decreasing ROS production and hsp-16.2 expression under oxidative stress conditions in vivo in the Caenorhabditis elegans model. Also, the extract showed higher inhibitory selectivity towards COX-2 than COX-1 in vitro with higher selectivity towards COX-2 than that of diclofenac. The extract also exhibited anti-inflammatory properties: It attenuated the edema thickness in a dose dependent fashion in carrageenan-induced hind-paw odema in rats. In addition, the extract reduced the carrageenan-induced leukocyte migration into the peritoneal cavity at the highest dose. Furthermore, the extract showed antipyretic and analgesic activities in a mouse model. Eugenia supra-axillaris appears to be a promising candidate in treating inflammation, pain and related oxidative stress diseases.

Epigallocatechin gallate attenuates arsenic induced genotoxicity via regulation of oxidative stress in balb/C mice

Arsenic is well known genotoxicant which causes the excessive generation of reactive oxygen species (ROS) and inhibition of antioxidant enzyme systems leading to cell damage through the activation of oxidative sensitive signaling pathways. Epigallocatechin gallate (EGCG), the main and active polyphenolic catechin present in green tea, has shown potent antioxidant, free radical scavenging and genoprotective activity in vivo. The present study attempted to investigate antioxidant and geno-protective efficacy of EGCG by regulating arsenic induced oxidative stress in mice. Animals received prophylactic and therapeutic treatments at two different doses (25 and 50mg/kg b.wt.) of EGCG orally for 15days and administered arsenic intraperitoneally at dose of 1.5mg/kg b.wt (1/10th of LD50) for 10days. Arsenic intoxication revealed enhanced ROS production (114%) in lymphocytes; elevated levels of LPO (2-4 fold); reduced levels of hepato-renal antioxidants (approx. 45%) and augmented genomic fragmentation in hepato-renal tissues; increased chromosomal anomalies (78%) and micronucleation (21.93%) in bone marrow cells and comet tailing (25%) in lymphocytes of mice. Both pre and post treatments of EGCG decreased ROS production, restored lipid peroxidation (LPO) and reduced hepato-renal antioxidants levels, reduced the DNA fragmentation, number of chromosomal aberrations (CA), micronucleation (MN), and comet tailing but prophylactic treatment of 50mg/kg b.wt was the most effective treatment in regulating arsenic induced oxidative stress. The effectiveness of this dose was furthermore validated by calculating the inhibitory index. Thus, results of present work empirically demonstrate free radical scavenging, anti-oxidative and genoprotective efficacy of EGCG against arsenic toxicity.