HO-1 Gene Expression Research Articles

Nephroprotective Effect of Embryonic Stem Cells Reducing Lipid Peroxidation in Kidney Injury Induced by Cisplatin.

Introduction The acute kidney injury (AKI) is characterized by a sudden glomerular filtration reduction. Renal or intrinsic causes of AKI include nephrotoxicity induced by exogenous agents like cisplatin, which causes oxidative stress altering the biochemical process and leading to apoptosis. Therefore, this research is aimed at analyzing the embryonic stem cells (ESC) nephroprotective effect in AKI induced by cisplatin, employing genetic, phenotypic, and microspectroscopic techniques. Methods Thirty mice were randomly divided into three groups (n = 10): the healthy, isotonic salt solution (ISS), and mouse embryonic stem cells (mESC) groups. The ISS and mESC groups were subjected to AKI using cisplatin; 24 h post-AKI received an intraperitoneal injection of ISS or 1 × 106 mESC, respectively. At days 4 and 8 post-AKI, five mice of each group were sacrificed to analyze the histopathological, genetic (PDK4 and HO-1), protein (p53), and vibrational microspectroscopic changes. Results Histopathologically, interstitial nephritis and acute tubular necrosis were observed; however, the mESC group showed a more preserved microarchitecture with high cellularity. Additionally, the PDK4 and HO-1 gene expression only increased in the ISS group on day 4 post-AKI. Likewise, p53 was more immunoexpressed at day 8 post-AKI in the ISS group. About biomolecular analysis by microspectroscopy, bands associated with lipids, proteins, and nucleic acids were evidenced. Besides, ratios related to membrane function (protein/lipid), unsaturated lipid content (olefinic/total lipid, olefinic/total CH2, and CH2/CH3), and lipid peroxidation demonstrated oxidative stress induction and lipid peroxidation increase mainly in the ISS group. Finally, the principal component analysis discriminated against each group; nonetheless, some data of the healthy and mESC groups at day 8 were correlated. Conclusions The mESC implant diminishes cisplatin nephrotoxicity, once the protective effect in the reduction of lipid peroxidation was demonstrated, reflecting a functional and histological restoration.

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.

Photoactive CO-releasing complexes containing iron - genotoxicity and ability in HO-1 gene induction in HL-60 cells.

This paper presents the results of research on the biological properties of two photoactive CO-releasing molecules containing iron, i.e. (η5-C5H5)Fe(CO)2(η1-N-maleimidato) (complex A) and (η5-C5H5)Fe(CO)2(η1-N-succinimidato) (complex B). We studied their cytotoxicity, genotoxicity and the ability of inducing the HO-1 gene in HL-60 cells. We also investigated the kinetics of DNA damage repair induced by complexes A and B. We demonstrated that complex B was not toxic to HL-60 cells in high doses (above 100 μM). The ability to induce DNA damage was higher for complex A. Importantly, there was no difference in irradiated and non-irradiated cells for both complexes. DNA damage induced by complex B was repaired efficiently, while the repair of DNA damage induced by complex A was disturbed. Complex B had a minor effect on HO-1 gene expression (less than 2-fold induction), while complex A had induced HO-1 gene expression to a great extent (over 17-fold for 10 μM) - similarly in irradiated and non-irradiated HL-60 cells. The results of our research indicate that the ability of both complexes to damage DNA and to upregulate HO-1 gene expression is not related to the release of CO. Further research is needed to test whether these compounds can be considered as potential CO carriers in humans.

Cytotoxicity and Pro-inflammatory Properties of Aliphatic Alpha, Beta-unsaturated Acid and Ester Monomers in RAW264.7 Cells and Their Chemical Reactivity

α,β-Unsaturated ester monomers such as methyl methacrylates (MMA), 2-hydroxyethyl methacrylates (2-HEMA), ethyleneglycol dimethacrylate (EGDMA) and triethyleneglycol dimetacrylate (TEGDMA) have been widely used in dentistry as dental materials. The present study was designed to clarify the proinflammatory activity of monomers. The cytotoxicity of the monomers and their effects on the expression of cyclooxygenase-2 (Cox2), nitric oxide synthase 2 (Nos2) and heme oxygenase 1 (Ho-1) mRNAs in RAW264.7 cells were determined using a cell counting kit and real-time reverse transcriptase-polymerase chain reaction, respectively. The cytotoxicity declined in the order n-butyl acrylate (nBA) > acrylic acid > TEGDMA > EGDMA > methacrylic acid ≈ 2-HEMA > lauryl methacrylate > nBMA > MMA. nBA and EGDMA at 1 mM up-regulated the expression of Cox2 mRNA. In contrast, 1 mM nBA and 10 mM 2-HEMA up-regulated the expression of Nos2 mRNA. Up-regulation of Ho-1 mRNA expression was found for 0.1 mM nBA, 1 mM EGDMA and 2 mM TEGDMA. The electrophilicity, ω was calculated on the basis of the density function theory BLYP/6-31G*. nBA and EGDMA with high ω values exerted potent pro-inflammatory activities. nBA, EGDMA and TEGDMA upregulated Ho-1 gene expression. Ho-1 gene activation of monomers may promote resistance of chemical carcinogenesis in biological systems.

Olmesartan ameliorates chemically-induced ulcerative colitis in rats via modulating NFκB and Nrf-2/HO-1 signaling crosstalk

Alteration in the expression pattern of Nrf-2 and NFκB has been reported in ulcerative colitis (UC) in which functional crosstalk between these two critical pathways has been suggested. The ameliorative potential of the AT1R blocker olmesartan (OLM) on oxidative stress and inflammatory cytokines has received considerable attention in recent years. Acetic acid (AA)-induced UC demonstrates close resemblance to human UC regarding histopathological features and cytokine profile and is associated with local intense immune response, oxidative stress and release of inflammatory cytokines. Therefore, The effect of OLM (1, 5 and 10 mg/kg) administered orally to rats subjected to intra-rectal instillation of 2 ml of 3% AA in saline solution is investigated. The study revealed that OLM ameliorated colon injury and inflammatory signs as visualized by histopathological examination. Levels of colon IL-6, TNF-α, IL-1β, TGF-β, and serum CRP were down-regulated, while the level of colon IL-10 was up-regulated. In a dose-dependent manner, OLM suppressed AA-induced neutrophils accumulation and improved colon anti-oxidant defense machinery. Also, OLM repressed the Bax:BCL-2 ratio and caspase3 expression. The mechanism of these protective effects was found to lay behind its ability to down-regulate gene expression and inhibit phosphorylation and nuclear translocation of p65 subunits. On the other hand, OLM up-regulated gene expression of Nrf-2 and HO-1. In conclusion, our data show that OLM is an Nrf2 activator, NFkB inhibitor and apoptosis inhibitor in an experimental model of ulcerative colitis. Overall, the study indicates that OLM shows promise as a potential therapy for the treatment of human inflammatory bowel diseases.

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.

Inflammatory and oxidative stress biomarkers at protein and molecular levels in workers occupationally exposed to crystalline silica.

Workers chronically exposed to respirable crystalline silica (CS) are susceptible to adverse health effects like silicosis and lung cancer. This study aimed to investigate potential early peripheral biomarkers of inflammation and oxidative stress in miners. The subjects enrolled in this study were occupationally unexposed workers (OUW, n= 29) and workers exposed to crystalline silica (WECS), composed by miners, which were divided into two subgroups: workers without silicosis (WECS I, n= 39) and workers diagnosed with silicosis, retired from work (WECS II, n= 42). The following biomarkers were evaluated: gene expression of L-selectin, CXCL2, CXCL8 (IL-8), HO-1, and p53; malondialdehyde (MDA) plasma levels and non-protein thiol levels in erythrocytes. Additionally, protein expression of L-selectin was evaluated to confirm our previous findings. The results demonstrated that gene expression of L-selectin was decreased in the WECS I group when compared to the OUW group (p< 0.05). Regarding gene expression of CXCL2, CXCL8 (IL-8), HO-1, and p53, significant fold change decreases were observed in workers exposed to CS in relation to unexposed workers (p< 0.05). The results of L-selectin protein expression in lymphocyte surface corroborated with our previous findings; thus, significant downregulation in the WECS groups was observed compared to OUW group (p< 0.05). The MDA was negatively associated with the gene expression of CXCL-2, CXCL8 (IL-8), and p53 (p< 0.05). The participants with silicosis (WECS II) presented significant increased non-protein thiol levels in relation to other groups (p< 0.05). Taken together, our findings may contribute to help the knowledge about the complex mechanisms involved in the silicosis pathogenesis and in the risk of lung cancer development in workers chronically exposed to respirable CS.

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

PO-086 Exercise enhances cardiac antioxidant capacity in diabetic rats through the Keap1/Nrf2 signaling pathway

Objective To investigate the effects of exercise on the myocardial oxidative stress injury of diabetic rats, and discussed the role of Keap1/Nrf2 signaling pathway in this process&#x0D; Methods Tyep 2 diabetic rat model was established by streptozotocin injection through abdominal cavity and high fat diet. The all the diabetic rats were divided into three groups: control group (NC), diabetes group(T2DM) and diabetes exercise group, NC and T2DM group were kept quiet for 8 weeks, T2DME group was trained for 8 weeks. After the exercise, weight, heart weight and blood were measured. MDA, T-SOD and GSH-PX enzyme were measured by biochemical method. Ho-1, Keap1, Nrf2 gene and protein expression were detected by RT-PCR and WesternBlotting.&#x0D; Results Compared with NC group, the weight of rats in the T2DM group significantly decreased [(528+/-71g vs 362+/-33g), P&lt;0.05], HWI significantly increased [(2.845+/-0.22 vs 3.841+/-0.21, P &lt;0.05], blood glucose was significantly increased [(6.4±3.8 vs 26±7.5mmol/L), P &lt;0.01],T-SOD and GSH-PX activity decreased significantly (P&lt;0.05), Ho-1 protein expression increased (P&lt;0.01), Keap1 and Nrf2 showed no significant changes, and Nrf2 nuclear transposition decreased (P&lt;0.05). Compared with the T2DM group, no significant change in body weight and heart weight in the T2DME group, with significant decrease in HWI[（3.841±0.21 vs 3.235±0.23），P＜0.05], with significant decrease in blood glucose [（26.0±7.5 vs 21.0±6.8），P＜0.05]. Ho-1 gene and protein expression increased significantly（P＜0.05and P＜0.01）, with no significant change of Keap1, while Nrf2 expression increased significantly (P &lt; 0.05), and Nrf2 nuclear transposition increased significantly (P &lt; 0.01).&#x0D; Conclusions Exercise activates the myocardial Keap1/Nrf2 signaling pathway in rats, promotes the expression of downstream antioxidant enzymes, increases cardiac antioxidant capacity, and resists diabetic myocardial oxidative stress injury.

Induction of brain Nrf2-HO-1 pathway and antinociception after different physical training paradigms in mice

AimActivation of the Nrf2-antioxidant response element signaling pathway is a major mechanism in the cellular defense against oxidative or electrophilic stress through conjugative reactions and by enhancing cellular antioxidant capacity. Although exercise training up-regulates antioxidant defenses system, while information regarding the intensity levels of physical exercise that acts on the cellular protection systems is limited. Main methodsThe present study evaluated the effects of different durations and intensities of physical exercise on the hippocampus, cortex and hypothalamus Nrf2 and HO-1 gene expression and related protein content and the nociception thresholds in adult C57Bl male mice. Exercise training consisted of daily running on a 10-lane rodent motor-driven treadmill for either 3 or 7 weeks at three different intensities. Pain responses were evaluated after exercise and in untrained mice by Von Frey hair test and cold plate test. Key findingsThis study confirmed that only vigorous and longer duration aerobic exercise increased Nrf2 protein level in the hippocampus and HO-1 protein level in the cortex and reduced pain perception. Mechanical and thermal hypoalgesia were only observed in exercise groups after 7 weeks of physical training. SignificanceThe overall findings in this study confirm that only the long duration intensive forced exercise reduced inflammatory pain by induction of Nrf2/HO-1 antioxidant signaling pathway.

Metabolic Responses in Endothelial Cells Following Exposure to Ketone Bodies.

The ketogenic diet (KD) is a high-fat, low-carbohydrate diet based on the induction of the synthesis of ketone bodies (KB). Despite its widespread use, the systemic impact of KD is not completely understood. The purpose of this study was to evaluate the effects of physiological levels of KB on HMEC-1 endothelial cells. To this aim, DNA oxidative damage and the activation of Nrf2, a known transcriptional factor involved in cell responses to oxidative stress, were assessed. The exposure of cells to KB exerted a moderate genotoxic effect, measured by a significant increase in DNA oxidative damage. However, cells pre-treated with KB for 48 h and subjected to a secondary oxidative insult (H2O2), significantly decreased DNA damage compared to control oxidized cells. This protection occurred by the activation of Nrf2 pathway. In KB-treated cells, we found increased levels of Nrf2 in nuclear extracts and higher gene expression of HO-1, a target gene of Nrf2, compared to control cells. These results suggest that KB, by inducing moderate oxidative stress, activate the transcription factor Nrf2, which induces the transcription of target genes involved in the cellular antioxidant defense system.

Exogenous Hydrogen Peroxide Contributes to Heme Oxygenase-1 Delaying Programmed Cell Death in Isolated Aleurone Layers of Rice Subjected to Drought Stress in a cGMP-Dependent Manner.

Hydrogen peroxide (H2O2) is a reactive oxygen species (ROS) that plays a dual role in plant cells. Here, we discovered that drought (20% polyethylene glycol-6000, PEG)-triggered decreases of HO-1 transcript expression and HO activity. However, exogenous H2O2 contributed toward the increase in HO-1 gene expression and activity of the enzyme under drought stress. Meanwhile, the HO-1 inducer hematin could mimic the effects of the H2O2 scavengers ascorbic acid (AsA) and dimethylthiourea (DMTU) and the H2O2 synthesis inhibitor diphenyleneiodonium (DPI) for scavenging or diminishing drought-induced endogenous H2O2. Conversely, the zinc protoporphyrin IX (ZnPPIX), an HO-1-specific inhibitor, reversed the effects of hematin. We further analyzed the endogenous H2O2 levels and HO-1 transcript expression levels of aleurone layers treated with AsA, DMTU, and DPI in the presence of exogenous H2O2 under drought stress, respectively. The results showed that in aleurone layers subjected to drought stress, when the endogenous H2O2 level was inhibited, the effect of exogenous H2O2 on the induction of HO-1 was enhanced. Furthermore, exogenous H2O2-activated HO-1 effectively enhanced amylase activity. Application of 8-bromoguanosine 3′,5′-cyclic guanosine monophosphate (8-Br-cGMP) (the membrane permeable cGMP analog) promoted the effect of exogenous H2O2-delayed PCD of aleurone layers in response to drought stress. More importantly, HO-1 delayed the programmed cell death (PCD) of aleurone layers by cooperating with nitric oxide (NO), and the delayed effect of NO on PCD was achieved via mediation by cGMP under drought stress. In short, in rice aleurone layers, exogenous H2O2 (as a signaling molecule) triggered HO-1 and delayed PCD via cGMP which possibly induced amylase activity under drought stress. In contrast, as a toxic by-product of cellular metabolism, the drought-generated H2O2 promoted cell death.

POTENTIAL DANGER OF NANOSIZED POWDER BLUE TO HUMAN HEALTH

The data analysis presented in the studies of leading Russian and foreign centers on physico-chemical, molecular and biological, cytological and toxicological characteristics of nanosized powder blue has been done. Generalization of the information received and evaluation of potentially hazardous substances has shown that nanodispersed powder blue has a high degree of potential danger to human health. Powder blue nanoparticles have a size in the range of 41.2-77.9 nm, preferably of spherical shape, are hydrophobical, potentially high reactive. They have the ability to intracellular generation of reactive oxygen species causing the oxidative stress (particularly oxidative damage to proteins and indirect damage to DNA). They are able to DNA direct damage, having a dose and time-dependent character. They interact with the cell membrane, causing it damage (cytotoxicity), as evidenced by the decrease in mitochondrial activity, LDH release from cells, and fall of cells viability. A significant induction of chromosome aberrations is typical for powder blue nanoparticles. They cause a disturbance in proteomic and metabolomic profile, increase antioxidant enzyme of gene expression of HO-1, the production of cytokines MCP-1 and IL-8. They have possibly carcinogenic activity to humans, due to an increase in the level of intracellular reactive oxygen species formation, signaling cascades, damage to macromolecules - proteins and DNA.

Induction of haem oxygenase-1 increases infection of dog macrophages by L. infantum.

We aimed to induce and inhibit HO-1, ascertaining its effect on infection rate, parasite load and the levels of superoxide, reactive oxygen species (ROS), nitric oxide (NO), TNF-alpha and IL-10 in cultured macrophages from healthy dogs infected by Leishmania infantum. Macrophages obtained from 15 healthy dogs were cultured alone or infected with L. infantum, with or without association of HO-1 inducer and inhibitor. The infection rate and the parasite load were determined by the number of infected macrophages and number of promastigotes per macrophage, respectively. HO-1 levels and gene expression, as well as IL-10 and TNF-alpha levels were also measured in these cultures. Superoxide, ROS and NO levels in macrophages were measured through flow cytometry. Induction of HO-1 increased the infection rate and parasite load, while its inhibition decreased the infection rate and IL-10 production. There was a positive correlation between HO-1 and infection rate or parasite load. Increased infection rate was associated with decreased superoxide, ROS and NO levels. Induction of HO-1 metabolism in dogs infected by L. infantum is possibly one of the mechanisms responsible for increasing the infection of macrophages, mainly through reduction in the oxidative and nitrosative metabolisms of these cells.

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.

Association of the haem oxygenase-1 gene with inflammatory bowel disease.

The anti-inflammatory genes, haem oxygenase 1 (HO-1, HMOX1) rs2071746 (unrestricted model: p = 9.07 × 10-4; recessive model: p = 4.99 × 10-4; multiplicative model: p = 0.0009; and additive model: p = 1.87 × 10-4) and interleukin-10 (IL-10) rs1800872 (dominant model: p = 0.0277) have been associated with paediatric inflammatory bowel disease. The present family-based case-trio study (n = 52) examined HO-1 gene expression in the presence of proinflammatory lipopolysaccharide and tumour necrosis factor-alpha in four B lymphocyte cell lines established from children with inflammatory bowel disease and demonstrated that mutations in IL-10 and IL-10 receptor B reduced HO-1 messenger RNA expression. This observation supports our hypothesis that HO-1 is regulated by the IL-10/STAT3 pathway and that both genes (IL10 and STAT3) could be involved in the pathogenesis of inflammatory bowel disease. We also compared HO-1 expression in diseased intestinal tissues with adjacent normal tissues from adults with inflammatory bowel disease. Of the 17 Crohn's disease patients, HO-1 expression in diseased tissues was downregulated in 9 patients (53%) and of the 10 ulcerative colitis patients HO-1 was downregulated in 7 patients (70%), compared with adjacent normal tissues. The downregulation of HO-1 gene expression may lower anti-inflammatory effects and worsen tissue injury in affected areas by inflammatory bowel disease.

Pharmacological activities of an eye drop containing Matricaria chamomilla and Euphrasia officinalis extracts in UVB-induced oxidative stress and inflammation of human corneal cells

Ultraviolet B (UVB) exposure is a risk factor for corneal damage resulting in oxidative stress, inflammation and cell death. The aim of this study was to investigate the potential protective effects of a commercial eye drop (Dacriovis™) containing Matricaria chamomilla and Euphrasia officinalis extracts on human corneal epithelial cells (HCEC-12) against UVB radiation-induced oxidative stress and inflammation as well as the underlying mechanisms. The antioxidant potential of the eye drops was evaluated by measuring the ferric reducing antioxidant power and the total phenolic content by Folin-Ciocalteu reagent. HCEC-12 cells were exposed to UVB radiation and treated with the eye drops at various concentrations. Cell viability, wound healing assay, reactive oxygen species (ROS) levels, protein and lipid oxidative damage and COX-2, IL-1β, iNOS, SOD-2, HO-1 and GSS gene expression, were assessed. Eye drops were able to protect corneal epithelial cells from UVB-induced cell death and ameliorated the wound healing; the eye drops exhibited a strong antioxidant activity, decreasing ROS levels and protein and lipid oxidative damage. Eye drops also exerted anti-inflammatory activities by decreasing COX-2, IL-1β, iNOS expression, counteracted UVB-induced GSS and SOD-2 expression and restored HO-1 expression to control levels. These findings suggest that an eye drop containing Matricaria chamomilla and Euphrasia officinalis extracts exerts positive effects against UVB induced oxidative stress and inflammation and may be useful in protecting corneal epithelial cells from UVB exposure.

A novel fine tuning scheme of miR-200c in modulating lung cell redox homeostasis

Oxidative stress induces miR-200c, the predominant microRNA (miRNA) in lung tissues; however, the antioxidant role and biochemistry of such induction have not been clearly defined. Therefore, a lung adenocarcinoma cell line (A549) and a normal lung fibroblast (MRC-5) were used as models to determine the effects of miR-200c expression on lung antioxidant response. Hydrogen peroxide (H2O2) upregulated miR-200c, whose overexpression exacerbated the decrease in cell proliferation, retarded the progression of cells in the G2/M-phase, and increased oxidative stress upon H2O2 stimulation. The expression of three antioxidant proteins, superoxide dismutase (SOD)-2, haem oxygenase (HO)-1, and sirtuin (SIRT) 1, was reduced upon H2O2 stimulation in miR-200c-overexpressed A549 cells. This phenomenon of increased oxidative stress and antioxidant protein downregulation also occurs simultaneously in miR-200c overexpressed MRC-5 cells. Molecular analysis revealed that miR-200c inhibited the gene expression of HO-1 by directly targeting its 3′-untranslated region. The downregulation of SOD2 and SIRT1 by miR-200c was mediated through zinc finger E-box-binding homeobox 2 (ZEB2) and extracellular signal-regulated kinase 5 (ERK5) pathways, respectively, where knockdown of ZEB2 or ERK5 decreased the expression of SOD2 or SIRT1 in A549 cells. LNA anti-miR-200c transfection in A549 cells inhibited the endogenous miR-200c expression, resulting in increased expressions of antioxidant proteins, reduced oxidative stress and recovered cell proliferation upon H2O2 stimulation. These findings indicate that miR-200c fine-tuned the antioxidant response of the lung cells to oxidative stress through several pathways, and thus this study provides novel information concerning the role of miR-200c in modulating redox homeostasis of lung.

SRT1720 Alleviates ANIT-Induced Cholestasis in a Mouse Model

Intrahepatic cholestasis is a kind of clinical syndrome along with hepatotoxicity which caused by intrahepatic and systemic accumulations of bile acid. There are several crucial generating factors of the pathogenesis of cholestasis, such as inflammation, dysregulation of bile acid transporters and oxidative stress. SIRT1 is regarded as a class III histone deacetylase (HDAC). According to a set of researches, SIRT1 is one of the most important factors which can regulate the hepatic bile acid metabolism. SRT1720 is a kind of activator of SIRT1 which is 1000 times more potent than resveratrol, and this paper is aimed to study its protective influence on hepatotoxicity and cholestasis induced by alpha-naphthylisothiocyanate (ANIT) in mice. The findings revealed that SRT1720 treatment increased FXR and Nrf2 gene expressions to shield against hepatotoxicity and cholestasis induced by ANIT. The mRNA levels of hepatic bile acid transporters were also altered by SRT1720. Furthermore, SRT1720 enhanced the antioxidative system by increasing Nrf2, SOD, GCLc, GCLm, Nqo1, and HO-1 gene expressions. In conclusion, a protective influence could be provided by SRT1720 to cure ANIT-induced hepatotoxicity and cholestasis, which was partly through FXR and Nrf2 activations. These results indicated that SIRT1 could be regarded as a therapeutic target to cure the cholestasis.