NQO1 Gene Expression Research Articles

Development of a standardized in vitro approach to evaluate microphysical, chemical, and toxicological properties of combustion-derived fine and ultrafine particles

Ultrafine particles represent a growing concern in the public health community but their precise role in many illnesses is still unknown. This lack of knowledge is related to the experimental difficulty in linking their biological effects to their multiple properties, which are important determinants of toxicity. Our aim is to propose an interdisciplinary approach to study fine (FP) and ultrafine (UFP) particles, generated in a controlled manner using a miniCAST (Combustion Aerosol Standard) soot generator used with two different operating conditions (CAST1 and CAST3). The chemical characterization was performed by an untargeted analysis using ultra-high resolution mass spectrometry. In conjunction with this approach, subsequent analysis by gas chromatography–mass spectrometry (GC–MS) was performed to identify polycyclic aromatic hydrocarbons (PAH). CAST1 enabled the generation of FP with a predominance of small PAH molecules, and CAST3 enabled the generation of UFP, which presented higher numbers of carbon atoms corresponding to larger PAH molecules. Healthy normal human bronchial epithelial (NHBE) cells differentiated at the air-liquid interface (ALI) were directly exposed to these freshly emitted FP and UFP. Expression of MUC5AC, FOXJ1, OCLN and ZOI as well as microscopic observation confirmed the ciliated pseudostratified epithelial phenotype. Study of the mass deposition efficiency revealed a difference between the two operating conditions, probably due to the morphological differences between the two categories of particles. We demonstrated that only NHBE cells exposed to CAST3 particles induced upregulation in the gene expression of IL-8 and NQO1. This approach offers new perspectives to study FP and UFP with stable and controlled properties.

Increased expression of autophagy and Nrf2-dependent signaling pathway genes by new monophenolic antioxidants depends on their structure

Under certain conditions, both activators and inhibitors of Nrf2-dependent signaling and autophagy can serve as potential agents for the prevention, treatment, and maintenance therapy of cancer, as well as overcoming chemoresistance. We are developing a panel of structurally related synthetic monophenolic compounds, in addition to a direct antioxidant effect, having the ability to affect intracellular signaling pathways and processes, including the above mentioned. Aim of the study was to investigate the relationship between its structure and the ability to influence the expression of autophagy and Nrf2 pathway genes.Material and methods. Five original hydrophilic phenolic structurally related compounds were synthesized; the prototypical inductor of the Keap1/Nrf2/ARE system, monosubstituted phenol tert-butylhydro-quinone (tBHQ), served as a reference substance. We used cultures of murine Lewis lung carcinoma (LLC) and human breast adenocarcinoma MCF-7 cells, with the test compounds at a concentration of 20 gM cells were incubated for 24 hours. Changes in mRNA expression of Nrf2, Nqo1, LC3b, and Sqstm1 genes encoding Nrf2, NAD(P)H:quinone oxidoreductase-1, LC3B, p62/sequestosome-1, respectively, were determined by TaqMan real-time PCR.Results and discussion. Structurally related synthetic monophenols effectively induced the Keap1/Nrf2/ARE system in LLC and MCF-7 cells, increasing the expression of the Nrf2-driven Nqo1 gene, and ambiguously affected the transcription of genes of proteins mediating autophagy: the content of mRNA of the LC3B protein did not change, while the expression of mRNA of the p62 protein, which affects the operation of both systems (processes), is increased only by the action of ortho-monosubstituted phenol with an «active» sulfur atom in the para-propyl substituent TS-13 and its structural analogue TS-12 with a para-substituent shortened by one methylene. It can be assumed that the observed effect either indicates the ability of TS-13 and TS-12 both to induce the Keap1/Nrf2/ARE system and to stimulate autophagy, or reflects a compound-mediated mutually reinforcing cross-activation of these processes.

Roflumilast protects from cisplatin-induced testicular toxicity in male rats and enhances its cytotoxicity in prostate cancer cell line. Role of NF-κB-p65, cAMP/PKA and Nrf2/HO-1, NQO1 signaling

Cisplatin (CIS)-induced testicular injury is a major obstacle in its application as antineoplastic agent. In this study, we investigated the protective effect and mechanism of roflumilast (ROF), a PDE4 inhibitor, against CIS-induced testicular toxicity in rats. Besides, the cytotoxic effect of CIS, with and without ROF, was evaluated on PC3 cell line. ROF reversed CIS-induced abnormalities in sperm characteristics, normalized serum testosterone level, and ameliorated CIS-induced alterations in testicular and epidydimal weights and restored normal testicular structure. Moreover, ROF increased intracellular cAMP level, PKA and HO-1 activities and Nrf2, NQO-1 and HO-1 gene expression, improved testicular oxidative stress parameters (TBARS, NO, GSH levels, and CAT activity) and inflammatory mediators (IL-1β and TNF-α, and NF-κβ p65gene expression) and reduced the proapoptotic proteins, caspase-3, Bax and increased Bcl-2. Lastly, in vitro analyses showed that ROF augmented the anticancer efficacy of CIS and enhanced the increase in gene expression of Nrf2, HO-1, and NQO-1 and the inhibition of gene expression of NF-κβ p65 induced by CIS and enhanced its apoptotic effect in PC3 cells. Conclusively, PDE4 inhibition with induction of Nrf2/HO-1, NQO-1 is a potential therapeutic approach to protect male reproductive system from the detrimental effects with augmenting, the antineoplastic effect of CIS.

Physicochemical Properties and Effects of Honeys on Key Biomarkers of Oxidative Stress and Cholesterol Homeostasis in HepG2 Cells.

Manuka honey and newly developed honeys (arjuna, guggul, jiaogulan and olive) were examined for their physicochemical, biochemical properties and effects on oxidative stress and cholesterol homeostasis in fatty acid-induced HepG2 cells. The honeys exhibited standard moisture content (<20%), electrical conductivity (<0.8 mS/cm), acidic pH, and monosaccharides (>60%), except olive honey (<60% total monosaccharides). They all expressed non-Newtonian behavior and 05 typical regions of the FTIR spectra as those of natural ones. Guggul and arjuna, manuka honeys showed the highest phenolic contents, correlating with their significant antioxidant activities. Arjuna, guggul and manuka honeys demonstrated the agreement of total cholesterol reduction and the transcriptional levels of AMPK, SREBP2, HCMGR, LDLR, LXRα. Jiaogulan honey showed the least antioxidant content and activity, but it was the most cytotoxic. Both jiaogulan and olive honeys modulated the tested gene in the pattern that should lead to a lower TC content, but this reduction did not occur after 24 h. All 2% concentrations of tested honeys elicited a clearer effect on NQO1 gene expression. In conclusion, the new honeys complied with international norms for natural honeys and we provide partial evidence for the protective effects of manuka, arjuna and guggul honeys amongst the tested ones on key biomarkers of oxidative stress and cholesterol homeostasis, pending further studies to better understand their modes of action.

Patulin activates the NRF2 pathway by modulation of miR-144 expression in HEK293 cells.

Patulin (PAT) is a mycotoxin produced by various fungal species that commonly contaminate apples and other fruit products. PAT is associated with glutathione (GSH) depletion and oxidative stress. Cytoprotective and antioxidant (AO) enzymes limit toxic outcomes and confer resistance to oxidative stress by influencing the expression of cytoprotective genes. The induction of these genes is tightly regulated by transcription factor nuclear factor erythroid 2 p45-related factor 2 (NRF2), a potentialtarget of microRNA (miR)-144. This study aims to determine a possible role for miR-144 in NRF2 pathway activation following PAT exposure in human embryonic kidney (HEK293) cells. HEK293 cells were exposed to varying PAT concentrations (0, 0.2, 0.5, 1μmol/L; 24h). Protein expression of Keap1, NRF2, and phosphorylated (p) NRF2 (ser40) was quantified using western blotting. Gene expression of NRF2, SOD2, CAT, GPx, NQO1, GSTA1, HMOX, and miR-144 were evaluated by qPCR. PAT significantly decreased miR-144 (p = 0.0249) and concomitantly increased NRF2 protein expression, stability, and activation as evidenced by increased pNRF2 (p = 0.0216) expression and decreased total NRF2 (p = 0.0237). This was consistent with qPCR data which showed increased transcript levels of NRF2 (p = 0.0378) as well as the target genes CAT (p = 0.0273), NQO1 (p = 0.0156), HMOX (p = 0.0249), and GSTA1 (p = 0.0237). No changes were observed in Keap1 expression (p = 0.6444). This study implicates microRNAs in a mechanistic role in PAT-induced toxicity. PAT decreased miR-144 expression leading to NRF2 pathway activation and elevated AO gene expression.

Oxygen-mediated lung injury in mice lacking the gene for NRF2: Rescue with the cytochrome P4501A-inducer, beta-naphthoflavone (BNF), and differential sex-specific effects

BackgroundAcute respiratory distress syndrome (ARDS) leads to progressive lung injury, which significantly impacts patient morbidity and mortality but may differ clinically between the sexes. Cytochrome P450 (CYP) 1A enzymes are protective against hyperoxic lung injury and may contribute to sex-dependent pathology. NRF2 is a critical transcriptional regulator of antioxidants and loss of NRF2 leads to severe hyperoxic lung injury and mortality in mice. NRF2 deficiencies and polymorphisms have been observed in patients with pulmonary diseases such as chronic obstructive pulmonary disease and severe asthma. No prior studies have evaluated whether there are sex-specific differences in oxygen-mediated lung injury in Nrf2−/− mice and there are few rescue studies. ObjectiveTo test the hypothesis that hyperoxia induces greater lung injury and inflammation in Nrf2−/− mice compared to wild type (WT) that differs between sexes, and that this phenotype will be rescued by the administration of the cytochrome P450 (CYP) 1A inducer beta-naphthoflavone (BNF). Design/MethodsMale and female 8-10-week-old WT or Nrf2−/− C57BL/6 mice were pre-treated with BNF (40 mg/kg) or corn oil control and exposed to hyperoxia (95% O2) for 68 h. Survival, pulmonary edema, neutrophil recruitment, and lung injury scores were evaluated. Gene expression of phase II detoxification enzymes, pulmonary cytokines, and Cyp1a1/2 was quantified. CYP1A1/2 protein expression and catalytic activities were also measured. ResultsHyperoxia exposure greatly reduced survival in Nrf2−/− mice, particularly in females. BNF treatment improved survival by 182.8% in Nrf2−/− females and by 41.4% in Nrf2−/− males as well as in WT females by 85.7%. Females had greater pulmonary edema as measured by lung weight to body weight ratios but was attenuated in all groups except Nrf2−/− females by BNF. Neutrophils doubled in Nrf2−/− lungs compared to WT in hyperoxia but were decreased in BNF-treated females of both genotypes. Pulmonary cytokine gene expression including Il-6 and Tnf-α increased in hyperoxia especially in Nrf2−/− mice and was unaffected by BNF. Pulmonary and hepatic Nqo1 gene expression w-as decreased in Nrf2−/− mice and was largely unaffected by BNF; however pulmonary Ho-1 did not vary significantly between the genotypes and was decreased in WT animals treated with BNF. Activities and protein expression of pulmonary and hepatic CYP1A1/2 were induced via BNF across all groups. Although hepatic Cyp1a2 gene expression was higher in Nrf2−/− males, the catalytic activity was higher in Nrf2−/− females. ConclusionsHyperoxia augmented lung injury in Nrf2−/− mice, and pre-treatment with BNF was protective against mortality and injury, eliminating the sex-dependent survival difference in both genotypes. Our results support the hypothesis that NRF2 protects mice against lung injury, and the fact that BNF rescues the lung injury phenotype in Nrf2−/− mice suggests that augmented CYP1A expression by BNF may contribute to the beneficial effects. Further studies could lead to the development of BNF and other flavonoids for the prevention/treatment of hyperoxic lung injury, particularly in vulnerable patients with relative NRF2 deficiency, regardless of sex.

Pharmacokinetics and pharmacodynamics of three oral formulations of curcumin in rats.

Curcumin (CUR) is a major component of turmeric Curcuma longa, which is often used in food or as a dietary supplement. The purpose of this preclinical study is to investigate the acute pharmacokinetic and pharmacodynamic (PK/PD) profiles of two commercially marketed CUR products (GNC and Vitamin Shoppe) and a CUR powder from Sigma in female rats. Plasma samples were collected at specific time points and analyzed for CUR and its metabolite curcumin-O-glucuronide. RNA was extracted from leukocytes and analyzed for the expression of Nrf2-mediated antioxidant genes Nrf2, Ho-1, and Nqo1 by qPCR as selected PD markers. CUR PK was characterized by a 2-compartment model (2CM) after intravenous (IV) or oral administrations. Compared to IV CUR, the absolute bioavailability (F) of CUR for GNC (GC) is 0.9%, Vitamin Shoppe (VC) is 0.6% and Sigma (SC) is 3.1%. Pharmacodynamically, all three formulations showed induction of antioxidant Nrf2, Ho-1 and Nqo1 gene expression in rat leucocytes. PK/PD modeling of CUR's effect on antioxidant gene expression was well captured by an indirect response model. Physiologically based PK modeling and simulation using GastroPlus described the observed PK data reasonably well. In summary, our current study shows that the absolute oral bioavailability of the parent CUR was very low for all three formulations. However, despite the low CUR plasma concentrations, all three oral CUR formulations displayed PD response in the induction of Nrf2-mediated antioxidant genes, suggesting the potential of oral CUR contributing to the overall health beneficial effects of oral CUR.

Moringa seed extract alleviates titanium oxide nanoparticles (TiO2-NPs)-induced cerebral oxidative damage, and increases cerebral mitochondrial viability.

To investigate the influence of Moringa seed extract (MSE) on the cerebral Nrf2/NQO1 signaling in TiO2-NPs-induced brain damage, 80 male albino rats were divided into four groups (n = 20); group I was used as a control, group II received TiO2-NPs (500mg/kg b.w/day orally) for 14days, group III received MSE (100mg/kg b.w/day orally) for 30days, and group IV received MSE an hour before TiO2-NPs administration with the same doses as before. Administration of TiO2-NPs was started on the 17th day for both groups (II) and (IV). Administration of MSE significantly increased the cerebral mitochondrial viability and Nrf2 level with a simultaneous increase of NQO1 mRNA expression. This designates a powerful antioxidant effect of MSE which is indicated by a significant reduction of INOS expression, MDA, TOS, OSI levels, and DNA fragmentation % with a significant increase of GSH concentration, SOD activities, and TAC. MSE possesses an anti-inflammatory effect by a significant reduction of IL-1β and TNF-α levels, and anti-apoptotic effect manifested by a significant reduction of caspase-3 and Fas levels. In harmonization, dopamine, serotonin concentrations, and acetylcholinesterase activities return back to normal as compared to control group. These results were confirmed by the histopathological features which were alleviated with MSE administration. In conclusion, Nrf2 plays a pivotal role in the mechanism of TiO2-NPs cerebral toxicity and MSE as a Nrf2 activator can provide a powerful cerebroprotective effect, whereas MSE increased the Nrf2 expression and consequently restore the antioxidant activity of brain cells by increasing NQO1 gene expression and cerebral mitochondrial viability as well as inhibition of pro-inflammatory and apoptotic mediators.

Anti-tumor properties of methoxylated analogues of resveratrol in malignant MCF-7 but not in non-tumorigenic MCF-10A mammary epithelial cell lines

Resveratrol is a plant-derived polyphenol that is known for its anti-inflammatory and anti-tumorigenic properties in in vitro and in vivo models. Recent studies show that some resveratrol analogues might be more potent anti-tumor agents, which may partly be attributed to their ability to activate the aryl hydrocarbon receptor (AHR). Here, the anti-tumorigenic properties of resveratrol and structural analogues oxyresveratrol, pinostilbene, pterostilbene and tetramethoxystilbene (TMS) were studied in vitro, using in the malignant human MCF-7 breast cancer cell line and non-tumorigenic breast epithelial cell line MCF-10A.Cell viability and migration assays showed that methoxylated analogues of resveratrol are more potent anti-tumorigenic compounds than resveratrol and its hydroxylated analogue oxyresveratrol, with 2,3’,4,5’-tetramethoxy-trans-stilbene (TMS) being the most potent compound. TMS decreased MCF-7 tumor cell viability with 50% at 3.6 μM and inhibited migration with 37.5 ± 14.8% at 3 μM. In addition, TMS activated the AHR more potently (EC50 in a reporter gene assay 2.0 μM) and induced AHR-mediated induction of cytochrome P450 1A1 (CYP1A1) activity (EC50 value of 0.7 μM) more than resveratrol and the other analogues tested. Cell cycle analysis showed that TMS induced a shift in cell cycle status from the G1 to the G2/M phase causing a cell cycle arrest in the MCF-7 cells, while no effect of TMS was observed in the non-tumorigenic MCF-10A mammary epithelial cell line. Gene expression analysis showed that 3 μM TMS increased gene expression of CYP1A1 (289-fold), CYP1B1 (5-fold) and Nqo1 (2-fold), and decreased gene expression of IL-8 (3-fold) in MCF-7 cells. In MCF-10A cells, 10 μM TMS also increased gene expression of CYP1A1 (5-fold) and CYP1B1 (2-fold), but decreased gene expression of Nqo1 (1.4-fold) in contrast to MCF-7 cells.TMS displays more potent anti-tumorigenic properties and activates the AHR more effectively than resveratrol. In addition, this is the first study to show that TMS, but not resveratrol, selectively inhibits the cell cycle of breast tumor cells and not the non-tumorigenic cells. Our study provides more insight in the anti-tumor properties of the methoxylated analogues of resveratrol in breast cells in vitro.

Moringa Isothiocyanate Activates Nrf2: Potential Role in Diabetic Nephropathy.

Moringa isothiocyanate (MIC-1) is the main active isothiocyanate found in Moringa oleifera, a plant consumed as diet and traditional herbal medicine. Compared to sulforaphane (SFN), MICs are less studied and most work have focused on its anti-inflammatory activity. The purpose of this study is to better understand the Nrf2-ARE antioxidant activity of MIC-1 and its potential in diabetic nephropathy. MIC-1 showed little toxicity from 1.25-5μM. MIC-1 activated Nrf2-ARE at similar levels to SFN. MIC-1 also increased gene expression of downstream Nrf2 genes NQO1, HO-1, and GCLC. Protein expression of HO-1 and GCLC was elevated in MIC-1-treated cells versus control. MIC-1 suppressed pro-inflammatory cytokines in LPS-stimulated macrophages. MIC-1 reduced levels of reactive oxygen species in high glucose (HG)-treated human renal proximal tubule HK-2 cells. RNA-seq was performed to examine the transcriptome in HK-2 cells exposed to HG with or without MIC-1. Ingenuity Pathway Analysis (IPA) of RNA-seq on HK-2 cells exposed to HG identified TGFβ1 and NQO1 regulation as potentially impacted and treatment of HG-exposed HK-2 cells with MIC-1 reversed the gene expression of these two pathways. Results implicate that the transcriptional regulator TGFβ1 signaling is activated by HG and that MIC-1 can inhibit HG-stimulated TGFβ1 activation. In summary, MIC-1 activates Nrf2-ARE signaling, increases expression of Nrf2 target genes, and suppresses inflammation, while also reducing oxidative stress and possibly TGFβ1 signaling in high glucose induced renal cells. Taken together, it appears that one potential therapeutic strategy for managing DN and is currently under development in clinic is Nrf2 activation.

Protective Effect of Low Molecular Weight Seleno-Aminopolysaccharide on the Intestinal Mucosal Oxidative Damage.

Low molecular weight seleno-aminopolysaccharide (LSA) is an organic selenium compound comprising selenium and low molecular weight aminopolysaccharide (LA), a low molecular weight natural linear polysaccharide derived from chitosan. LSA has been found to exert strong pharmacological activity. In this study, we aimed to investigate the protective effect of LSA on intestinal mucosal oxidative stress in a weaning piglet model by detecting the growth performance, intestinal mucosal structure, antioxidant indices, and expression level of intracellular transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) and its related factors. Our results indicated that LSA significantly increased the average daily gain and feed/gain (p < 0.05), suggesting that LSA can effectively promote the growth of weaning piglets. The results of scanning electron microscope (SEM) microscopy showed that LSA effectively reduced intestinal damage, indicating that LSA improved the intestinal stress response and protected the intestinal structure integrity. In addition, diamine oxidase (DAO) and d-lactic acid (d-LA) levels remarkably decreased in LSA group compared with control group (p < 0.05), suggesting that LSA alleviated the damage and permeability of weaning piglets. LSA significantly increased superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), and total antioxidant capacity (T-AOC) levels, but decreased malondialdehyde (MDA) level, indicating that LSA significantly enhanced the antioxidant capacity and reduced oxidative stress in weaning piglets. RT-PCR results showed that LSA significantly increased GSH-Px1, GSH-Px2, SOD-1, SOD-2, CAT, Nrf2, HO-1, and NQO1 gene expression (p < 0.05). Western blot analysis revealed that LSA activated the Nrf2 signaling pathway by downregulating the expression of Keap1 and upregulating the expression of Nrf2 to protect intestinal mucosa against oxidative stress. Collectively, LSA reduced intestinal mucosal damage induced by oxidative stress via Nrf2-Keap1 pathway in weaning stress of infants.

Effect of dimethyl fumarate on neuroinflammation and apoptosis in pentylenetetrazol kindling model in rats

ObjectiveRole of apoptosis and neuroinflammation have been well established in the pathogenesis of epilepsy. It has been reported that the activation of nuclear factor-erythroid 2-related factor-2 (Nrf2) contributes to the attenuation of inflammation by inhibiting nuclear factor-kB (NF-kB) pathway. Therefore, the present study was designed to evaluate anti-inflammatory and anti-apoptotic role of dimethyl fumarate (DMF), an activator of Nrf2, in chemical kindling model in rats. MethodsChemical kindling model was established in Wistar rats by intraperitoneal (i.p.) administration of pentylenetetrazole (PTZ). Animals were treated with DMF (60 mg/kg) to activate the Nrf2 antioxidant response element (ARE) pathway. The animals were assessed for seizure score, neuronal damage and inflammatory cytokines levels (IL-1β, IL-6 and TNF-α) in hippocampus. The mRNA levels of various genes (Nrf2, HO-1, NQO1, Bcl2, Bax, Caspase 3, NF-kB, IL-6, IL-1β and TNF-α) were quantified by real-time PCR. The expression of anti-oxidative (Nrf2), apoptotic (Bax, Bcl2) and inflammatory (NF-kB) proteins were analysed by western blot. Immunohistochemistry (Bax) and electron microscopy were done to assess apoptosis. ResultsThe results showed reduction in the seizure score, percentage of kindled rats and neurological damage score in DMF treated rats. Pro-inflammatory cytokines concentrations were also decreased by DMF treatment. DMF downregulated the expression of inflammatory (NF-kB) and apoptotic (Bax, Caspase-3) genes and protein. DMF treatment increased the gene expression of Nrf2, HO-1, NQO1, Bcl-2 and protein expression of Nrf2 and Bcl2. ConclusionDMF demonstrated anti-apoptotic, anti-inflammatory and anti-oxidative effect in hippocampus, which might be regulated by increased level of antioxidant response elements.

301 - Aerobic exercise in older adults maintains Nrf2 signaling compared to inactive controls

We have previously shown that older men have impaired Nrf2 signaling response to acute exercise as compared to young controls. The present RCT investigated whether exercise-induced Nrf2 signaling would improve with a more regular exercise stimulus. Inactive men and women (62-77y) were randomized to an 8-week exercise intervention (EX, n=9) or a non-exercise control group (CON, n=8). EX performed supervised aerobic exercise 3d/wk for 45-min/d. The effectiveness of the exercise intervention was measured by changes in maximal aerobic capacity (VO2max). Nrf2 signaling was measured in response to acute exercise (30-min cycling at 70% VO2max) in isolated PBMCs. Nrf2 protein quantification was measured at 7 time points (Pre, +10, +30, +1, +4, +8, +24h) and gene expression of HO-1, NQO1, and GCLC were measured at 5 time points (Pre, +1, +4, +8, and +24h) before and after the 8-week intervention. There were no significant differences between sexes for any variable or baseline differences between EX and CON. The exercise intervention improved VO2max by 19% (p

Mechanistic Role of Cytochrome P450 1B1 in Hyperoxic Lung Injury

Supplemental oxygen is often used to assist those with respiratory dysfunction, including adults with acute respiratory distress syndrome (ARDS) and bronchopulmonary dysplasia (BPD) in preterm infants. Experimental evidence has shown that increases in oxygen levels can create a hyperoxic environment that is capable of exacerbating existing pulmonary injury as well as independently inducing injury due to increases in reactive oxygen species (ROS) and oxidative stress. Our group has examined the role of cytochrome P450 (CYP) enzymes in hyperoxic toxicity because of their possible role in the generation of ROS. We have previously found that CYP1A1/1A2 as well as the aryl hydrocarbon receptor (AHR), protect against hyperoxic toxicity. We have also found that CYP1B1 may, in fact, contribute to hyperoxic toxicity in vitro and in Cyp1b1‐null mice. Further, we found that Cyp1b1‐null mice exposed to hyperoxia have decreased markers of oxidative stress and increased CYP1A gene expression compared to WT mice. In this study, we hypothesized that Cyp1b1‐null mice would be less susceptible to hyperoxic lung injury compared to WT mice and that CYP1A mechanistically contributes to the attenuated phenotype of Cyp1b1‐null mice. To test this hypothesis, we exposed male and female C57BL/6J (WT), Cyp1b1‐null, Cyp1a1/1b1‐null (DKO), and Cyp1a1/1a2/1b1‐null (TKO) mice to hyperoxia (&gt;95% O2) for 24–68 hours. Lung weight measurements were used to assess pulmonary injury and edema and qPCR was used to measure RNA. We found that all mice lacking CYP1B1, including DKO and TKO mice, had reduced pulmonary injury as indicated by reduced lung weights in male (P&lt;0.01) and female (P&lt;0.05) mice after 68 hours of hyperoxia. CYP1B1 gene expression was induced (P&lt;0.01) in WT mice during hyperoxia exposure, and CYP1A1 gene expression was increased in Cyp1b1‐null mice (P=0.01). NQO1 gene expression was significantly induced by hyperoxia (P&lt;0.05) in all groups with higher expression in TKO mice at room air (P&lt;0.001) and early phase of hyperoxia (P&lt;0.05). We found that pulmonary AHR repressor (AHRR) expression was increased in the DKO and TKO (P&lt;0.05) mice after hyperoxia exposure. Our results suggest that increased AHR‐dependent transcription, as evidenced by enhanced CYP1A1 and AHRR gene expression, may play a role in attenuating lung injury in mice lacking CYP1B1 and needs to be elucidated further. Future studies will thoroughly characterize the effect of CYP1B1 on oxidative stress in these animals and determine the viability of CYP1B1‐directed therapeutics to treat or prevent ARDS/BPD.Support or Funding InformationResearch reported in this publication was supported by the National Institutes of Health under award number R01ES019689, R01ES009132, R01HL12516, R01HL129794, and R01HL087174 to B.M. and T32GM088129 to A.V. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Modulated Gene Expression of Toxoplasma gondii Infected Retinal Pigment Epithelial Cell Line (ARPE-19) via PI3K/Akt or mTOR Signal Pathway.

Due to the critical location and physiological activities of the retinal pigment epithelial (RPE) cell, it is constantly subjected to contact with various infectious agents and inflammatory mediators. However, little is known about the signaling events in RPE involved in Toxoplasma gondii infection and development. The aim of the study is to screen the host mRNA transcriptional change of 3 inflammation-related gene categories, PI3K/Akt pathway regulatory components, blood vessel development factors and ROS regulators, to prove that PI3K/Akt or mTOR signaling pathway play an essential role in regulating the selected inflammation-related genes. The selected genes include PH domain and leucine- rich-repeat protein phosphatases (PHLPP), casein kinase2 (CK2), vascular endothelial growth factor (VEGF), pigment epithelium-derived factor (PEDF), glutamate-cysteine ligase (GCL), glutathione S-transferase (GST), and NAD(P)H: quinone oxidoreductase (NQO1). Using reverse transcription polymerase chain reaction (RT-PCR) and quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR), we found that T. gondii up-regulates PHLPP2, CK2β, VEGF, GCL, GST, and NQO1 gene expression levels, but down-regulates PHLPP1 and PEDF mRNA transcription levels. PI3K inhibition and mTOR inhibition by specific inhibitors showed that most of these host gene expression patterns were due to activation of PI3K/Akt or mTOR pathways with some exceptional cases. Taken together, our results reveal a new molecular mechanism of these gene expression change dependent on PI3K/Akt or mTOR pathways and highlight more systematical insight of how an intracellular T. gondii can manipulate host genes to avoid host defense.

Photodynamic therapy using talaporfin sodium induces heme oxygenase-1 expression in rat malignant meningioma KMY-J cells.

Photodynamic therapy (PDT) using talaporfin sodium (TS) is tumor cell-selective less invasive therapy for the treatment of malignant glioma. We previously demonstrated that PDT using TS (TS-PDT) treatment exhibits anti-tumor activity against not only glioblastoma cells but also malignant meningioma cells. In general, various stress response proteins have been reported to affect the sensitivity determination for anticancer agents against tumor cells. However, the relationship between the therapeutic effect of TS-PDT and stress response systems in tumor cells is not adequately investigated. In this study, we investigated the gene expression of stress response proteins, including Sod1, Cat1, Gstp1, Gpx1, Nqo1, and Hmox1, in rat malignant meningioma KMY-J cells after treatment of TS-PDT. TS-PDT treatment significantly decreased the cell viability when compared with the no laser irradiation group. In morphological observation, TS at 25.6 µM treatment exhibited a significant cytotoxic effect after 12 hr of laser irradiation to KMY-J cells. After 3 and 6 hr of TS-PDT treatment, mRNA expression of heme oxygenase-1 (HO-1, encoded by Hmox1) was significantly increased by TS-PDT treatment. We also demonstrated that zinc protoporphyrin IX (ZnPPIX), a HO-1 inhibitor, significantly augmented the cytotoxic effect of TS-PDT treatment. These data suggest that HO-1 induction may contribute to a protective response against TS-PDT treatment in the malignant meningioma cells and may attenuate the therapeutic effect for TS-PDT treatment.

43 - Clinical Evaluation of the Safety and Therapeutic Potential of the Electrophilic Fatty Acid Nitroalkene 10-nitro-octadec-9-enoic acid (10-NO2-OA)

The post-translational modification (PTM) of significantly expands the functional proteome. Reactions of nitric oxide (NO) and nitrite (NO2‒) yield products such as nitrogen dioxide (•NO2) that nitrates lipids. Electrophilic fatty acid nitroalkenes (NO2-FA) induce PTM by reversible Michael addition with protein thiols. Multiple transcriptional regulatory proteins contain hyper-reactive functionally-significant nucleophilic amino acids, giving cells a capability for oxidative stress-related adaptive signaling responses. 10-NO2-OA, a synthetic homolog of a species found endogenously, mediates adaptive signaling responses. Human Phase 1 trials of oral and IV formulations of 10-NO2-OA are now revealing the human pharmacology of 10-NO2-OA. Obese (BMI 27-39.5 kg/m2) males were recruited as a surrogate population expressing metabolic and inflammatory stress conditions. Subjects (n=13) received oral 10-NO2-OA (25, 150 or 450 mg) or placebo once daily for 14 d and were fed a uniform diet to limit biomarker and BMI variability. Separately, normal BMI volunteers received 0.34 or 0.68 mg/kg IV 10-NO2-OA. Decreased serum NF-κB-regulated cytokines [leptin, monocyte chemoattractant protein (MCP-1) and Interleukin-6], serum triglycerides and serum cholesterol levels were observed in the high BMI cohort. Increased gene expression of NQO1, HO-1, and HSPA1A/B was observed in PBMNCs (NQO1, HO-1) and urinary exosomes (NQO1, HO-1, HSPA1A/B) in the IV drug-treated group. These responses affirmed that the NFkB, Keap1/Nrf2 and HSF-1 pathway engagement by 10-NO2-OA, observed in preclinical models, is recapitulated in humans. The oral and IV administration of 10-NO2-OA was safe, tolerated and bioavailable.

Editor's Highlight: Fragrance Allergens Linalool and Limonene Allylic Hydroperoxides in Skin Allergy: Mechanisms of Action Focusing on Transcription Factor Nrf2.

Allergic contact dermatitis is regarded as the most frequent expression of immunotoxicity in humans. Many odorant terpenes commonly used in fragrance compositions are considered as weak skin sensitizers, whereas some of their autoxidation products, allylic hydroperoxides, are classified as strong sensitizers according to the local lymph node assay. However, the mechanism of their effects on the immune system remains unclear. Since dendritic cells play a key role in allergic contact dermatitis, we studied their activation by the frequently used linalool (LINA) and limonene (LIMO), and their respective sensitizing allylic hydroperoxides (LINA-OOH, LIMO-OOH). The THP-1 cell-line was used as a surrogate for dendritic cells, the model currently employed in the validated h-CLAT in vitro test. Our data showed that allylic hydroperoxides behave differently. Both LINA-OOH and LIMO-OOH oxidized cell surface thiols 30 min after stimulation. However, the oxidative stress induced by LINA-OOH was stronger, with a higher decreased GSH/GSSG ratio and a stronger reactive species production. Moreover, LINA-OOH induced a stronger Nrf2 accumulation in correlation with nqo1 and ho-1 gene expression, 2 Nrf2 target genes. Regarding signaling pathways involved in these effects, P38 mitogen-activated protein kinase and P-ERK were activated in response to LINA-OOH but not with LIMO-OOH. CD54 and CD86 were induced 24-h postexposure. In contrast, LINA and LIMO did not modify THP-1 phenotype. This work underlies that autoxidation forming allylic hydroperoxide (ROOH) does not lead to equal chemical reactivity since LINA-OOH appears to be a stronger activator than LIMO-OOH, in regard to oxidative stress and Nrf2 pathway activation.

Triptolide induces Sertoli cell apoptosis in mice via ROS/JNK-dependent activation of the mitochondrial pathway and inhibition of Nrf2-mediated antioxidant response.

Triptolide (TP), an oxygenated diterpene, has a variety of beneficial pharmacodynamic activities but its clinical applications are restricted due to severe testicular injury. This study aimed to delineate the molecular mechanisms of TP-induced testicular injury in vitro and in vivo. TP (5-50000 nmol/L) dose-dependently decreased the viability of TM4 Sertoli cells with an IC50 value of 669.5-269.45 nmol/L at 24 h. TP (125, 250, and 500 nmol/L) dose-dependently increased the accumulation of ROS, the phosphorylation of JNK, mitochondrial dysfunction and activation of the intrinsic apoptosis pathway in TM4 cells. These processes were attenuated by co-treatment with the antioxidant N-acetyl cysteine (NAC, 1 mmol/L). Furthermore, TP treatment inhibited the translocation of Nrf2 from cytoplasm into the nucleus as well as the expression of downstream genes NAD(P)H quinone oxidoreductase1 (NQO1), catalase (CAT) and hemeoxygenase 1 (HO-1), thus abrogating Nrf2-mediated defense mechanisms against oxidative stress. Moreover, siRNA knockdown of Nrf2 significantly potentiated TP-induced apoptosis of TM4 cells. The above results from in vitro experiments were further validated in male mice after oral administration of TP (30, 60, and 120 mg·kg-1·d-1, for 14 d), as evidenced by the detected indexes, including dose-dependently decreased SDH activity, increased MDA concentration, altered testicle histomorphology, elevated caspase-3 activation, apoptosis induction, increased phosphorylation of JNK, and decreased gene expression of NQO1, CAT and HO-1 as well as nuclear protein expression of Nrf2 in testicular tissue. Our results demonstrate that TP activates apoptosis of Sertoli cells and injury of the testis via the ROS/JNK-mediated mitochondrial-dependent apoptosis pathway and down-regulates Nrf2 activation.

HIV-1 decreases Nrf2/ARE activity and phagocytic function in alveolar macrophages.

Respiratory complications occur frequently in individuals living with human immunodeficiency-1 virus (HIV) infection, and there is evidence that HIV-related oxidative stress impairs alveolar macrophage immune function. We hypothesized that nuclear factor (erythroid-derived 2)-like 2 (Nrf2), a master transcription factor that activates the antioxidant response element (ARE) and regulates antioxidant defenses, has an important role in alveolar macrophage (AMs) immune dysfunction in individuals with HIV infections. To test that hypothesis, we analyzed human monocyte-derived macrophages (MDMs) that were either infected with HIV-1 or were exposed to the HIV-related proteins gp120 and Tat ex vivo and determined that either stress affected the expression of Nrf2 and the Nrf2-ARE-dependent genes for NAD(P)H dehydrogenase, quinone 1 (NQO1) and glutamate-cysteine ligase, catalytic subunit (GCLC). We then determined that the expression of Nrf2, NQO1, and GCLC was significantly decreased in primary AMs isolated from HIV-1 transgenic rats. In parallel, treating a rat macrophage cell line (NR8383 cells) with the HIV-related proteins gp120 or Tat similarly decreased the gene and protein expression of Nrf2, NQO1, and GCLC. Further, phagocytic function was decreased in both human MDMs infected with HIV-1 and primary AMs from HIV-1 transgenic rats. Importantly, treating HIV-1-infected human MDMs or AMs from HIV-1 transgenic rats with sulforaphane (SFN, an Nrf2 activator) significantly improved their phagocytic function. The salutary effects of SFN were abrogated by silencing RNA to Nrf2 in wild-type rat macrophages. Our findings demonstrate that HIV-1 infection and exposure to HIV-1-related proteins inhibit Nrf2-ARE activity in the AMs and impair their phagocytic function. Treatments targeted at increasing Nrf2-ARE activity could, therefore, enhance lung innate immunity in people living with HIV-1.