(+)-Nootkatone and (+)-valencene from rhizomes of Cyperus rotundus increase survival rates in septic mice due to heme oxygenase-1 induction.

Science.gov (United States)

Tsoyi, Konstantin; Jang, Hwa Jin; Lee, Young Soo; Kim, Young Min; Kim, Hye Jung; Seo, Han Geuk; Lee, Jae Heun; Kwak, Jong Hwan; Lee, Dong-Ung; Chang, Ki Churl

2011-10-11

The rhizomes of Cyperus rotundus have been used as traditional folk medicine for the treatment of inflammatory diseases. However, the mechanism by which extract of rhizomes of Cyperus rotundus (ECR) elicits anti-inflammation has not been extensively investigated so far. The aim of the present study was to test whether heme oxygenase (HO)-1 induction is involved in the anti-inflammatory action of ECR. Induction of HO-1 and inhibition of inducible nitric oxide synthase (iNOS)/NO production by ECR and its 12 constituents (3 monoterpenes, 5 sesquiterpenes, and 4 aromatic compounds) were investigated using RAW264.7 cells in vitro. In addition, anti-inflammatory action of ECR and its two active ingredients (nookkatone, valencene) were confirmed in sepsis animal model in vivo. ECR increased HO-1 expression in a concentration-dependent manner, which was correlated with significant inhibition of iNOS/NO production in LPS-activated RAW264.7 cells. Among 12 compounds isolated from ECR, mostly sesquiterpenes induced stronger HO-1 expression than monoterpenes in macrophage cells. Nootkatone and valencene (sesquiterpenes) significantly inhibited iNOS expression and NO production in LPS-simulated RAW264.7 cells. Inhibition of iNOS expression by nootkatone, valencene, and ECR were significantly reduced in siHO-1 RNA transfected cells. Furthermore, all three showed marked inhibition of high mobility group box-1 (HMGB1) in LPS-activated macrophages and increased survival rates in cecal ligation and puncture (CLP)-induced sepsis in mice. Taken together, we concluded that possible anti-inflammatory mechanism of ECR is, at least, due to HO-1 induction, in which sesquiterpenes such as nootkatone and valencene play a crucial role. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

UVA-induced protection of skin through the induction of heme oxygenase-1.

Science.gov (United States)

Xiang, Yuancai; Liu, Gang; Yang, Li; Zhong, Julia Li

2011-12-01

UVA (320-400 nm) and UVB (290-320 nm) are the major components of solar UV irradiation, which is associated with various pathological conditions. UVB causes direct damage to DNA of epidermal cells and is mainly responsible for erythema, immunosuppression, photoaging, and skin cancer. UVA has oxidizing properties that can cause damage or enhance UVB damaging effects on skin. On the other hand, UVA can also lead to high levels of heme oxygenase-1 (HO-1) expression of cells that can provide an antioxidant effect on skin as well as anti-inflammatory properties in mammals and rodents. Therefore, this review focuses on the potential protection of UVA wavebands for the skin immune response, instead of mechanisms that underlie UVA-induced damage. Also, the role of HO-1 in UVA-mediated protection against UVB-induced immunosuppression in skin will be summarized. Thus, this review facilitates further understanding of potential beneficial mechanisms of UVA irradiation, and using the longer UVA (UVA1, 340-400 nm) in combination with HO-1 for phototherapy and skin protection against sunlight exposure.

Pharmacological Induction of Heme Oxygenase-1 Impairs Nuclear Accumulation of Herpes Simplex Virus Capsids upon Infection

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Francisco J. Ibáñez

2017-10-01

Full Text Available Heme oxygenase-1 (HO-1 is an inducible enzyme that is expressed in response to physical and chemical stresses, such as ultraviolet radiation, hyperthermia, hypoxia, reactive oxygen species (ROS, as well as cytokines, among others. Its activity can be positively modulated by cobalt protoporphyrin (CoPP and negatively by tin protoporphirin (SnPP. Once induced, HO-1 degrades iron-containing heme into ferrous iron (Fe2+, carbon monoxide (CO and biliverdin. Importantly, numerous products of HO-1 are cytoprotective with anti-apoptotic, anti-oxidant, anti-inflammatory, and anti-cancer effects. The products of HO-1 also display antiviral properties against several viruses, such as the human immunodeficiency virus (HIV, influenza, hepatitis B, hepatitis C, and Ebola virus. Here, we sought to assess the effect of modulating HO-1 activity over herpes simplex virus type 2 (HSV-2 infection in epithelial cells and neurons. There are no vaccines against HSV-2 and treatment options are scarce in the immunosuppressed, in which drug-resistant variants emerge. By using HSV strains that encode structural and non-structural forms of the green fluorescent protein (GFP, we found that pharmacological induction of HO-1 activity with CoPP significantly decreases virus plaque formation and the expression of virus-encoded genes in epithelial cells as determined by flow cytometry and western blot assays. CoPP treatment did not affect virus binding to the cell surface or entry into the cytoplasm, but rather downstream events in the virus infection cycle. Furthermore, we observed that treating cells with a CO-releasing molecule (CORM-2 recapitulated some of the anti-HSV effects elicited by CoPP. Taken together, these findings indicate that HO-1 activity interferes with the replication cycle of HSV and that its antiviral effects can be recapitulated by CO.

Beyond gastric acid reduction: Proton pump inhibitors induce heme oxygenase-1 in gastric and endothelial cells

International Nuclear Information System (INIS)

Becker, Jan C.; Grosser, Nina; Waltke, Christian; Schulz, Stephanie; Erdmann, Kati; Domschke, Wolfram; Schroeder, Henning; Pohle, Thorsten

2006-01-01

Proton pump inhibitors (PPIs) have been demonstrated to prevent gastric mucosal injury by mechanisms independent of acid inhibition. Here we demonstrate that both omeprazole and lansoprazole protect human gastric epithelial and endothelial cells against oxidative stress. This effect was abrogated in the presence of the heme oxygenase-1 (HO-1) inhibitor ZnBG. Exposure to either PPI resulted in a strong induction of HO-1 expression on mRNA and protein level, and led to an increased activity of this enzyme. Expression of cyclooxygenase isoforms 1 and 2 remained unaffected, and COX-inhibitors did not antagonize HO-1 induction by PPIs. Our results suggest that the antioxidant defense protein HO-1 is a target of PPIs in both endothelial and gastric epithelial cells. HO-1 induction might account for the gastroprotective effects of PPIs independently of acid inhibition, especially in NSAID gastropathy. Moreover, our findings provide additional perspectives for a possible but yet unexplored use of PPIs in vasoprotection

Beyond gastric acid reduction: Proton pump inhibitors induce heme oxygenase-1 in gastric and endothelial cells

Energy Technology Data Exchange (ETDEWEB)

Becker, Jan C [Department of Medicine B, University of Muenster, 48149 Muenster (Germany); Grosser, Nina [Department of Pharmacology and Toxicology, School of Pharmacy, Martin Luther University, Halle-Wittenberg, 06099 Halle (Saale) (Germany); Waltke, Christian [Department of Medicine B, University of Muenster, 48149 Muenster (Germany); Schulz, Stephanie [Department of Pharmacology and Toxicology, School of Pharmacy, Martin Luther University, Halle-Wittenberg, 06099 Halle (Saale) (Germany); Erdmann, Kati [Department of Pharmacology and Toxicology, School of Pharmacy, Martin Luther University, Halle-Wittenberg, 06099 Halle (Saale) (Germany); Domschke, Wolfram [Department of Medicine B, University of Muenster, 48149 Muenster (Germany); Schroeder, Henning [Department of Pharmacology and Toxicology, School of Pharmacy, Martin Luther University, Halle-Wittenberg, 06099 Halle (Saale) (Germany); Pohle, Thorsten [Department of Medicine B, University of Muenster, 48149 Muenster (Germany)

2006-07-07

Proton pump inhibitors (PPIs) have been demonstrated to prevent gastric mucosal injury by mechanisms independent of acid inhibition. Here we demonstrate that both omeprazole and lansoprazole protect human gastric epithelial and endothelial cells against oxidative stress. This effect was abrogated in the presence of the heme oxygenase-1 (HO-1) inhibitor ZnBG. Exposure to either PPI resulted in a strong induction of HO-1 expression on mRNA and protein level, and led to an increased activity of this enzyme. Expression of cyclooxygenase isoforms 1 and 2 remained unaffected, and COX-inhibitors did not antagonize HO-1 induction by PPIs. Our results suggest that the antioxidant defense protein HO-1 is a target of PPIs in both endothelial and gastric epithelial cells. HO-1 induction might account for the gastroprotective effects of PPIs independently of acid inhibition, especially in NSAID gastropathy. Moreover, our findings provide additional perspectives for a possible but yet unexplored use of PPIs in vasoprotection.

Role of the Nrf2-heme oxygenase-1 pathway in silver nanoparticle-mediated cytotoxicity

International Nuclear Information System (INIS)

Kang, Su Jin; Ryoo, In-geun; Lee, Young Joon; Kwak, Mi-Kyoung

2012-01-01

Silver nanoparticles (nano-Ag) have been widely used in various commercial products including textiles, electronic appliances and biomedical products. However, there remains insufficient information on the potential risk of nano-Ag to human health and environment. In the current study, we have investigated the role of NF-E2-related factor 2 (Nrf2) transcription factor in nano-Ag-induced cytotoxicity. When Nrf2 expression was blocked using interring RNA expression in ovarian carcinoma cell line, nano-Ag treatment showed a substantial decrease in cell viability with concomitant increases in apoptosis and DNA damage compared to the control cells. Target gene analysis revealed that the expression of heme oxygenase-1 (HO-1) was highly elevated by nano-Ag in nonspecific shRNA expressing cells, while Nrf2 knockdown cells (NRF2i) did not increase HO-1 expression. The role of HO-1 in cytoprotection against nano-Ag was reinforced by results using pharmacological inducer of HO-1: cobalt protoporphyrin-mediated HO-1 activation in the NRF2i cells prevented nano-Ag-mediated cell death. Similarly, pharmacological or genetic inhibition of HO-1 in nonspecific control cells exacerbated nano-Ag toxicity. As the upstream signaling mechanism, nano-Ag required the phosphoinositide 3-kinase (PI3K) and p38MAPK signaling cascades for HO-1 induction. The treatment with either PI3K inhibitor or p38MAPK inhibitor suppressed HO-1 induction and intensified nano-Ag-induced cell death. Taken together, these results suggest that Nrf2-dependent HO-1 up-regulation plays a protective role in nano-Ag-induced DNA damage and consequent cell death. In addition, nano-Ag-mediated HO-1 induction is associated with the PI3K and p38MAPK signaling pathways. -- Highlights: ► Role of Nrf2 signaling in silver nanoparticle toxicity. ► Silver nanoparticle toxicity is increased by Nrf2 blockade. ► Nrf2-dependent HO-1 induction protects cells from silver nanoparticle toxicity. ► PI3K and p38MAPK cascades are

Regulation of human heme oxygenase-1 gene expression under thermal stress.

Science.gov (United States)

Okinaga, S; Takahashi, K; Takeda, K; Yoshizawa, M; Fujita, H; Sasaki, H; Shibahara, S

1996-06-15

Heme oxygenase-1 is an essential enzyme in heme catabolism, and its human gene promoter contains a putative heat shock element (HHO-HSE). This study was designed to analyze the regulation of human heme oxygenase-1 gene expression under thermal stress. The amounts of heme oxygenase-1 protein were not increased by heat shock (incubation at 42 degrees C) in human alveolar macrophages and in a human erythroblastic cell line, YN-1-0-A, whereas heat shock protein 70 (HSP70) was noticeably induced. However, heat shock factor does bind in vitro to HHO-HSE and the synthetic HHO-HSE by itself is sufficient to confer the increase in the transient expression of a reporter gene upon heat shock. The deletion of the sequence, located downstream from HHO-HSE, resulted in the activation of a reporter gene by heat shock. These results suggest that HHO-HSE is potentially functional but is repressed in vivo. Interestingly, heat shock abolished the remarkable increase in the levels of heme oxygenase-1 mRNA in YN-1-0-A cells treated with hemin or cadmium, in which HSP70 mRNA was noticeably induced. Furthermore, transient expression assays showed that heat shock inhibits the cadmium-mediated activation of the heme oxygenase-1 promoter, whereas the HSP70 gene promoter was activated upon heat shock. Such regulation of heme oxygenase-1 under thermal stress may be of physiologic significance in erythroid cells.

Mycobacterium tuberculosis Induction of Heme Oxygenase-1 Expression Is Dependent on Oxidative Stress and Reflects Treatment Outcomes

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Neesha Rockwood

2017-05-01

Full Text Available The antioxidant enzyme heme oxygenase-1 (HO-1 is implicated in the pathogenesis of tuberculosis (TB and has been proposed as a biomarker of active disease. Nevertheless, the mechanisms by which Mycobacterium tuberculosis (Mtb induces HO-1 as well as how its expression is affected by HIV-1 coinfection and successful antitubercular therapy (ATT are poorly understood. We found that HO-1 expression is markedly increased in rabbits, mice, and non-human primates during experimental Mtb infection and gradually decreased during ATT. In addition, we examined circulating concentrations of HO-1 in a cohort of 130 HIV-1 coinfected and uninfected pulmonary TB patients undergoing ATT to investigate changes in expression of this biomarker in relation to HIV-1 status, radiological disease severity, and treatment outcome. We found that plasma levels of HO-1 were elevated in untreated HIV-1 coinfected TB patients and correlated positively with HIV-1 viral load and negatively with CD4+ T cell count. In both HIV-1 coinfected and Mtb monoinfected patients, HO-1 levels were substantially reduced during successful TB treatment but not in those who experienced treatment failure or subsequently relapsed. To further delineate the molecular mechanisms involved in induction of HO-1 by Mtb, we performed a series of in vitro experiments using mouse and human macrophages. We found that Mtb-induced HO-1 expression requires NADPH oxidase-dependent reactive oxygen species production induced by the early-secreted antigen ESAT-6, which in turn triggers nuclear translocation of the transcription factor NRF-2. These observations provide further insight into the utility of HO-1 as a biomarker of both disease and successful therapy in TB monoinfected and HIV-TB coinfected patients and reveal a previously undocumented pathway linking expression of the enzyme with oxidative stress.

The induction of heme oxygenase-1 suppresses heat shock protein 90 and the proliferation of human breast cancer cells through its byproduct carbon monoxide

Energy Technology Data Exchange (ETDEWEB)

Lee, Wen-Ying [Department of Pathology, Chi-Mei Hospital, Tainan, Taiwan (China); Department of Pathology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan (China); Chen, Yen-Chou [Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan (China); Shih, Chwen-Ming; Lin, Chun-Mao; Cheng, Chia-Hsiung; Chen, Ku-Chung [Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan (China); Department of Biochemistry, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan (China); Lin, Cheng-Wei, E-mail: cwlin@tmu.edu.tw [Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan (China); Department of Biochemistry, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan (China)

2014-01-01

Heme oxygenase (HO)-1 is an oxidative stress-response enzyme which catalyzes the degradation of heme into bilirubin, ferric ion, and carbon monoxide (CO). Induction of HO-1 was reported to have antitumor activity; the inhibitory mechanism, however, is still unclear. In the present study, we found that treatment with [Ru(CO){sub 3}Cl{sub 2}]{sub 2} (RuCO), a CO-releasing compound, reduced the growth of human MCF7 and MDA-MB-231 breast cancer cells. Analysis of growth-related proteins showed that treatment with RuCO down-regulated cyclinD1, CDK4, and hTERT protein expressions. Interestingly, RuCO treatment resulted in opposite effects on wild-type and mutant p53 proteins. These results were similar to those of cells treated with geldanamycin (a heat shock protein (HSP)90 inhibitor), suggesting that RuCO might affect HSP90 activity. Moreover, RuCO induced mutant p53 protein destabilization accompanied by promotion of ubiquitination and proteasome degradation. The induction of HO-1 by cobalt protoporphyrin IX (CoPP) showed consistent results, while the addition of tin protoporphyrin IX (SnPP), an HO-1 enzymatic inhibitor, diminished the RuCO-mediated effect. RuCO induction of HO-1 expression was reduced by a p38 mitogen-activated protein kinase inhibitor (SB203580). Additionally, treatment with a chemopreventive compound, curcumin, induced HO-1 expression accompanied with reduction of HSP90 client protein expression. The induction of HO-1 by curcumin inhibited 12-O-tetradecanoyl-13-acetate (TPA)-elicited matrix metalloproteinase-9 expression and tumor invasion. In conclusion, we provide novel evidence underlying HO-1's antitumor mechanism. CO, a byproduct of HO-1, suppresses HSP90 protein activity, and the induction of HO-1 may possess potential as a cancer therapeutic. - Highlights: • CO and HO-1 inhibited the growth of human breast cancer cells. • CO and HO-1 attenuated HSP90 and its client proteins expression. • CO induced mutant p53 protein

Heme oxygenase-1 mediates BAY 11-7085 induced ferroptosis.

Science.gov (United States)

Chang, Ling-Chu; Chiang, Shih-Kai; Chen, Shuen-Ei; Yu, Yung-Luen; Chou, Ruey-Hwang; Chang, Wei-Chao

2018-03-01

Ferroptosis is a form of oxidative cell death and has become a chemotherapeutic target for cancer treatment. BAY 11-7085 (BAY), which is a well-known IκBα inhibitor, suppressed viability in cancer cells via induction of ferroptotic death in an NF-κB-independent manner. Reactive oxygen species scavenging, relief of lipid peroxidation, replenishment of glutathione and thiol-containing agents, as well as iron chelation, rescued BAY-induced cell death. BAY upregulated a variety of Nrf2 target genes related to redox regulation, particularly heme oxygenase-1 (HO-1). Studies with specific inhibitors and shRNA interventions suggested that the hierarchy of induction is Nrf2-SLC7A11-HO-1. SLC7A11 inhibition by erastin, sulfasalazine, or shRNA interference sensitizes BAY-induced cell death. Overexperession of SLC7A11 attenuated BAY-inhibited cell viability. The ferroptotic process induced by hHO-1 overexpression further indicated that HO-1 is a key mediator of BAY-induced ferroptosis that operates through cellular redox regulation and iron accumulation. BAY causes compartmentalization of HO-1 into the nucleus and mitochondrion, and followed mitochondrial dysfunctions, leading to lysosome targeting for mitophagy. In this study, we first discovered that BAY induced ferroptosis via Nrf2-SLC7A11-HO-1 pathway and HO-1 is a key mediator by responding to the cellular redox status. Copyright © 2017 Elsevier B.V. All rights reserved.

A Heme Oxygenase-1 Transducer Model of Degenerative and Developmental Brain Disorders

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Hyman M. Schipper

2015-03-01

Full Text Available Heme oxygenase-1 (HO-1 is a 32 kDa protein which catalyzes the breakdown of heme to free iron, carbon monoxide and biliverdin. The Hmox1 promoter contains numerous consensus sequences that render the gene exquisitely sensitive to induction by diverse pro-oxidant and inflammatory stimuli. In “stressed” astroglia, HO-1 hyperactivity promotes mitochondrial iron sequestration and macroautophagy and may thereby contribute to the pathological iron deposition and bioenergetic failure documented in Alzheimer disease, Parkinson disease and certain neurodevelopmental conditions. Glial HO-1 expression may also impact neuroplasticity and cell survival by modulating brain sterol metabolism and the proteasomal degradation of neurotoxic proteins. The glial HO-1 response may represent a pivotal transducer of noxious environmental and endogenous stressors into patterns of neural damage and repair characteristic of many human degenerative and developmental CNS disorders.

Opposite effect of oxidative stress on inducible nitric oxide synthase and haem oxygenase-1 expression in intestinal inflammation: anti-inflammatory effect of carbon monoxide

NARCIS (Netherlands)

Dijkstra, Gerard; Blokzijl, Hans; Bok, Lisette; Homan, Manon; van Goor, Harry; Faber, Klaas Nico; Jansen, Peter L. M.; Moshage, Han

2004-01-01

Inducible nitric oxide synthase (iNOS) is expressed in intestinal epithelial cells (IEC) of patients with active inflammatory bowel disease (IBD) and in IEC of endotoxaemic rats. The induction of iNOS in IEC is an element of the NF-kappaB-mediated survival pathway. Haem oxygenase-1 (HO-1) is an

Functional characterization of diverse ring-hydroxylating oxygenases and induction of complex aromatic catabolic gene clusters in Sphingobium sp. PNB

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Pratick Khara

2014-01-01

Full Text Available Sphingobium sp. PNB, like other sphingomonads, has multiple ring-hydroxylating oxygenase (RHO genes. Three different fosmid clones have been sequenced to identify the putative genes responsible for the degradation of various aromatics in this bacterial strain. Comparison of the map of the catabolic genes with that of different sphingomonads revealed a similar arrangement of gene clusters that harbors seven sets of RHO terminal components and a sole set of electron transport (ET proteins. The presence of distinctly conserved amino acid residues in ferredoxin and in silico molecular docking analyses of ferredoxin with the well characterized terminal oxygenase components indicated the structural uniqueness of the ET component in sphingomonads. The predicted substrate specificities, derived from the phylogenetic relationship of each of the RHOs, were examined based on transformation of putative substrates and their structural homologs by the recombinant strains expressing each of the oxygenases and the sole set of available ET proteins. The RHO AhdA1bA2b was functionally characterized for the first time and was found to be capable of transforming ethylbenzene, propylbenzene, cumene, p-cymene and biphenyl, in addition to a number of polycyclic aromatic hydrocarbons. Overexpression of aromatic catabolic genes in strain PNB, revealed by real-time PCR analyses, is a way forward to understand the complex regulation of degradative genes in sphingomonads.

Relationship of Heme Oxygenase-1 (HO-1 Level with Onset and Severity in Normotensive Pregnancy and Severe Preeclampsia

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John Johannes Wantania

2016-08-01

Full Text Available Background: Preeclampsia still becomes a major problem in pregnancies. Various evidences showed that heme oxygenase-1 (HO-1 is very important in pregnancy. This study aims to understand the relationship of heme oxygenase-1 level with onset and severity in normotensive pregnancy and severe preeclampsia. Methods: This is a cross sectional analytic comparative study, the subjects consisted of 26 patients with normotensive pregnancies and 26 patients with severe preeclampsia. Blood samples from women with < 34 / ≥ 34 weeks’ normotensive pregnancies and women with severe preeclampsia were taken. HO-1 ELISA kit used to quantitate heme oxygenase-1 level in samples. Results: The level of heme oxygenase-1 in normotensive pregnant women < 34 weeks lower than severe preeclampsia pregnant women < 34 weeks (3.28 ± 0.46 ng/mL vs 4.20 ± 0.64 ng/mL, p=0.003, respectively. The median level of heme oxygenase-1 in normotensive pregnant women ≥ 34 weeks was 2.96 (2.41–4.39 ng/mL, while severe preeclampsia pregnant women ≥ 34 weeks was 3.52 (2.88–5.43 ng/mL, (p=0.040. The median level of heme oxygenase-1 in normotensive pregnant women was 3.04 (2.41–4.39 ng/mL, while severe preeclampsia pregnant women was 3.68 (2.88–5.67 ng/mL, (p=0.001. Conclusions: There is correlation between the incidence of severe preeclampsia with heme oxygenase-1 level in < 34 and ≥ 34 weeks of pregnancy. There is a significant difference between the level of heme oxygenase-1 in pregnant women with severe preeclampsia and in women with normotensive pregnancy. 

Anti-inflammatory and heme oxygenase-1 inducing activities of lanostane triterpenes isolated from mushroom Ganoderma lucidum in RAW264.7 cells

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Choi, Solip [Department of Biochemistry, College of Natural Sciences, Kangwon National University, Chuncheon, Gangwon-Do 200-701 (Korea, Republic of); Nguyen, Van Thu [College of Pharmacy, Catholic University of Daegu, Gyeongsan 712-702 (Korea, Republic of); Tae, Nara; Lee, Suhyun [Department of Biochemistry, College of Natural Sciences, Kangwon National University, Chuncheon, Gangwon-Do 200-701 (Korea, Republic of); Ryoo, Sungwoo [Department of Biological Sciences, College of Natural Sciences, Kangwon National University, Chuncheon, Gangwon-Do 200-701 (Korea, Republic of); Min, Byung-Sun [College of Pharmacy, Catholic University of Daegu, Gyeongsan 712-702 (Korea, Republic of); Lee, Jeong-Hyung, E-mail: jhlee36@kangwon.ac.kr [Department of Biochemistry, College of Natural Sciences, Kangwon National University, Chuncheon, Gangwon-Do 200-701 (Korea, Republic of)

2014-11-01

Ganoderma lucidum is a popular medicinal mushroom used in traditional medicine for preventing or treating a variety of diseases. In the present study, we investigated the anti-inflammatory and heme oxygenase (HO)-1 inducing effects of 12 lanostane triterpenes from G. lucidum in RAW264.7 cells. Of these, seven triterpenes, butyl lucidenateE{sub 2}, butyl lucidenateD{sub 2} (GT-2), butyl lucidenate P, butyl lucidenateQ, Ganoderiol F, methyl ganodenate J and butyl lucidenate N induced HO-1 expression and suppressed lipopolysaccharide (LPS)-induced nitric oxide (NO) production. Inhibiting HO-1 activity abrogated the inhibitory effects of these triterpenes on the production of NO in LPS-stimulated RAW264.7 cells, suggesting the involvement of HO-1 in the anti-inflammatory effects of these triterpenes. We further studied the anti-inflammatory and HO-1 inducing effects of GT-2. Mitogen-activated protein kinase inhibitors or N-acetylcysteine, an antioxidant, did not suppress GT-2-mediated HO-1 induction; however, LY294002, a phosphoinositide 3-kinase (PI3K) inhibitor, blocked GT-2-induced HO-1 mRNA and protein expression. GT-2 increased nuclear translocation of nuclear factor-E2-related factor 2 (Nrf2) and knockdown of Nrf2 by small interfering RNA blocked GT-2-mediated HO-1 induction, suggesting that GT-2 induced HO-1 expression via the PI3K/AKT-Nrf2 pathway. Consistent with the notion that HO-1 has anti-inflammatory properties, GT-2 inhibited the production of tumor necrosis factor-α and interleukin-6, as well as inducible nitric oxide synthase and cyclooxygenase-2 expression. These findings suggest that HO-1 inducing activities of these lanostane triterpenes may be important in the understanding of a novel mechanism for the anti-inflammatory activity of G. lucidum. - Highlights: • The anti-inflammatory effects of selected triterpenes from Ganoderma lucidum are demonstrated. • Heme oxygenase-1 induction is attributable to the anti-inflammatory properties of these

Anti-inflammatory and heme oxygenase-1 inducing activities of lanostane triterpenes isolated from mushroom Ganoderma lucidum in RAW264.7 cells

International Nuclear Information System (INIS)

Choi, Solip; Nguyen, Van Thu; Tae, Nara; Lee, Suhyun; Ryoo, Sungwoo; Min, Byung-Sun; Lee, Jeong-Hyung

2014-01-01

Ganoderma lucidum is a popular medicinal mushroom used in traditional medicine for preventing or treating a variety of diseases. In the present study, we investigated the anti-inflammatory and heme oxygenase (HO)-1 inducing effects of 12 lanostane triterpenes from G. lucidum in RAW264.7 cells. Of these, seven triterpenes, butyl lucidenateE 2 , butyl lucidenateD 2 (GT-2), butyl lucidenate P, butyl lucidenateQ, Ganoderiol F, methyl ganodenate J and butyl lucidenate N induced HO-1 expression and suppressed lipopolysaccharide (LPS)-induced nitric oxide (NO) production. Inhibiting HO-1 activity abrogated the inhibitory effects of these triterpenes on the production of NO in LPS-stimulated RAW264.7 cells, suggesting the involvement of HO-1 in the anti-inflammatory effects of these triterpenes. We further studied the anti-inflammatory and HO-1 inducing effects of GT-2. Mitogen-activated protein kinase inhibitors or N-acetylcysteine, an antioxidant, did not suppress GT-2-mediated HO-1 induction; however, LY294002, a phosphoinositide 3-kinase (PI3K) inhibitor, blocked GT-2-induced HO-1 mRNA and protein expression. GT-2 increased nuclear translocation of nuclear factor-E2-related factor 2 (Nrf2) and knockdown of Nrf2 by small interfering RNA blocked GT-2-mediated HO-1 induction, suggesting that GT-2 induced HO-1 expression via the PI3K/AKT-Nrf2 pathway. Consistent with the notion that HO-1 has anti-inflammatory properties, GT-2 inhibited the production of tumor necrosis factor-α and interleukin-6, as well as inducible nitric oxide synthase and cyclooxygenase-2 expression. These findings suggest that HO-1 inducing activities of these lanostane triterpenes may be important in the understanding of a novel mechanism for the anti-inflammatory activity of G. lucidum. - Highlights: • The anti-inflammatory effects of selected triterpenes from Ganoderma lucidum are demonstrated. • Heme oxygenase-1 induction is attributable to the anti-inflammatory properties of these triterpenes

Immunolocalization of heme oxygenase-1 in periodontal diseases

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G Gayathri

2014-01-01

Conclusion: The results of our study is an increasing evidence of involvement of antioxidant enzymes like heme oxygenase-1 in periodontal inflammation and their implication for treatment of chronic periodontitis.

Targeted expression of heme oxygenase-1 prevents the pulmonary inflammatory and vascular responses to hypoxia

Science.gov (United States)

Minamino, Tohru; Christou, Helen; Hsieh, Chung-Ming; Liu, Yuxiang; Dhawan, Vijender; Abraham, Nader G.; Perrella, Mark A.; Mitsialis, S. Alex; Kourembanas, Stella

2001-07-01

Chronic hypoxia causes pulmonary hypertension with smooth muscle cell proliferation and matrix deposition in the wall of the pulmonary arterioles. We demonstrate here that hypoxia also induces a pronounced inflammation in the lung before the structural changes of the vessel wall. The proinflammatory action of hypoxia is mediated by the induction of distinct cytokines and chemokines and is independent of tumor necrosis factor- signaling. We have previously proposed a crucial role for heme oxygenase-1 (HO-1) in protecting cardiomyocytes from hypoxic stress, and potent anti-inflammatory properties of HO-1 have been reported in models of tissue injury. We thus established transgenic mice that constitutively express HO-1 in the lung and exposed them to chronic hypoxia. HO-1 transgenic mice were protected from the development of both pulmonary inflammation as well as hypertension and vessel wall hypertrophy induced by hypoxia. Significantly, the hypoxic induction of proinflammatory cytokines and chemokines was suppressed in HO-1 transgenic mice. Our findings suggest an important protective function of enzymatic products of HO-1 activity as inhibitors of hypoxia-induced vasoconstrictive and proinflammatory pathways.

Crystallization and preliminary X-ray diffraction analyses of the redox-controlled complex of terminal oxygenase and ferredoxin components in the Rieske nonhaem iron oxygenase carbazole 1,9a-dioxygenase

Energy Technology Data Exchange (ETDEWEB)

Matsuzawa, Jun; Aikawa, Hiroki; Umeda, Takashi [The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657 (Japan); Ashikawa, Yuji [The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657 (Japan); Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555 (Japan); Suzuki-Minakuchi, Chiho [The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657 (Japan); Kawano, Yoshiaki [RIKEN SPring-8 Center, RIKEN Harima Branch, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Fujimoto, Zui [National Institute of Agrobiological Sciences, 2-1-2 Kannondai, Tsukuba, Ibaraki 305-8602 (Japan); Okada, Kazunori [The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657 (Japan); Yamane, Hisakazu [Teikyo University, 1-1 Toyosatodai, Utsunomiya, Tochigi 320-0003 (Japan); Nojiri, Hideaki, E-mail: anojiri@mail.ecc.u-tokyo.ac.jp [The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657 (Japan)

2014-09-25

A crystal was obtained of the complex between reduced terminal oxygenase and oxidized ferredoxin components of carbazole 1,9a-dioxygenase. The crystal belonged to space group P2{sub 1} and diffracted to 2.25 Å resolution. The initial reaction in bacterial carbazole degradation is catalyzed by carbazole 1,9a-dioxygenase, which consists of terminal oxygenase (Oxy), ferredoxin (Fd) and ferredoxin reductase components. The electron-transfer complex between reduced Oxy and oxidized Fd was crystallized at 293 K using the hanging-drop vapour-diffusion method with PEG 3350 as the precipitant under anaerobic conditions. The crystal diffracted to a maximum resolution of 2.25 Å and belonged to space group P2{sub 1}, with unit-cell parameters a = 97.3, b = 81.6, c = 116.2 Å, α = γ = 90, β = 100.1°. The V{sub M} value is 2.85 Å{sup 3} Da{sup −1}, indicating a solvent content of 56.8%.

Oxidative stress suppression by luteolin-induced heme oxygenase-1 expression

International Nuclear Information System (INIS)

Sun, Gui-bo; Sun, Xiao; Wang, Min; Ye, Jing-xue; Si, Jian-yong; Xu, Hui-bo; Meng, Xiang-bao; Qin, Meng; Sun, Jing; Wang, Hong-wei; Sun, Xiao-bo

2012-01-01

Luteolin, a flavonoid that exhibits antioxidative properties, exerts myocardial protection effects. However, the underlying molecular mechanisms are not yet fully understood. To investigate the effects of luteolin on myocardial injury protection and its possible mechanisms, a myocardial injury model was established with intragastric administration of 4 mg/kg isoproterenol (ISO) to male Sprague–Dawley rats (200–220 g) daily for 2 days. We found that pretreatment of luteolin (160, 80 and 40 mg/kg, i.g., respectively) daily for 15 days can prevent ISO-induced myocardial damage, including decrease of serum cardiac enzymes, improvement electrocardiography and heart vacuolation. Luteolin also improved the free radical scavenging and antioxidant potential, suggesting one possible mechanism of luteolin-induced cardio-protection is mediated by blocking the oxidative stress. To clarify the mechanisms, we performed the in vitro study by hydrogen peroxide (H 2 O 2 )-induced cytotoxicty model in H9c2 cells. We found that luteolin pretreatment prevented apoptosis, increased the expression of heme oxygenase-1 (HO-1), and enhanced the binding of Nrf2 to the antioxidant response element, providing an adaptive survival response against H 2 O 2 -derived oxidative cytotoxicity. The addition of Znpp, a selective HO-1 competitive inhibitor, reduced the cytoprotective ability of luteolin, indicating the vital role of HO-1 on these effects. Luteolin also activated Akt and ERK, whereas the addition of LY294002 and U0126, the pharmacologic inhibitors of PI3K and ERK, attenuated luteolin-induced HO-1 expression and cytoprotective effect. Taken together, the above findings suggest that luteolin protects against myocardial injury and enhances cellular antioxidant defense capacity through the activation of Akt and ERK signal pathways that leads to Nrf2 activation, and subsequently HO-1 induction. -- Highlights: ► Luteolin prevents isoproterenol-induced myocardial damage. ► Luteolin

Oxidative stress suppression by luteolin-induced heme oxygenase-1 expression

Energy Technology Data Exchange (ETDEWEB)

Sun, Gui-bo; Sun, Xiao; Wang, Min [Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100193 (China); Ye, Jing-xue [Jilin Agricultural University, No.2888, Xincheng Street, Changchun, 130021, Jilin (China); Si, Jian-yong [Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100193 (China); Xu, Hui-bo [Academy of Chinese Medical Sciences of Jilin Province, Gongnongda road 1745, Changchun, 130021, Jiblin (China); Meng, Xiang-bao; Qin, Meng; Sun, Jing [Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100193 (China); Wang, Hong-wei, E-mail: hwang@nju.edu.cn [Center for Translational Medicine and Jiangsu Key Laboratory of Molecular Medicine, Medical School of Nanjing University, Nanjing 210093 (China); Sun, Xiao-bo, E-mail: sunsubmit@163.com [Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100193 (China)

2012-12-01

Luteolin, a flavonoid that exhibits antioxidative properties, exerts myocardial protection effects. However, the underlying molecular mechanisms are not yet fully understood. To investigate the effects of luteolin on myocardial injury protection and its possible mechanisms, a myocardial injury model was established with intragastric administration of 4 mg/kg isoproterenol (ISO) to male Sprague–Dawley rats (200–220 g) daily for 2 days. We found that pretreatment of luteolin (160, 80 and 40 mg/kg, i.g., respectively) daily for 15 days can prevent ISO-induced myocardial damage, including decrease of serum cardiac enzymes, improvement electrocardiography and heart vacuolation. Luteolin also improved the free radical scavenging and antioxidant potential, suggesting one possible mechanism of luteolin-induced cardio-protection is mediated by blocking the oxidative stress. To clarify the mechanisms, we performed the in vitro study by hydrogen peroxide (H{sub 2}O{sub 2})-induced cytotoxicty model in H9c2 cells. We found that luteolin pretreatment prevented apoptosis, increased the expression of heme oxygenase-1 (HO-1), and enhanced the binding of Nrf2 to the antioxidant response element, providing an adaptive survival response against H{sub 2}O{sub 2}-derived oxidative cytotoxicity. The addition of Znpp, a selective HO-1 competitive inhibitor, reduced the cytoprotective ability of luteolin, indicating the vital role of HO-1 on these effects. Luteolin also activated Akt and ERK, whereas the addition of LY294002 and U0126, the pharmacologic inhibitors of PI3K and ERK, attenuated luteolin-induced HO-1 expression and cytoprotective effect. Taken together, the above findings suggest that luteolin protects against myocardial injury and enhances cellular antioxidant defense capacity through the activation of Akt and ERK signal pathways that leads to Nrf2 activation, and subsequently HO-1 induction. -- Highlights: ► Luteolin prevents isoproterenol-induced myocardial damage. �

Involvement of heme oxygenase-1 in β-cyclodextrin-hemin complex-induced cucumber adventitious rooting process.

Science.gov (United States)

Lin, Yuting; Li, Meiyue; Huang, Liqin; Shen, Wenbiao; Ren, Yong

2012-09-01

Our previous results showed that β-cyclodextrin-hemin complex (CDH) exhibited a vital protective role against cadmium-induced oxidative damage and toxicity in alfalfa seedling roots by the regulation of heme oxygenase-1 (HO-1) gene expression. In this report, we further test whether CDH exhibited the hormonal-like response. The application of CDH and an inducer of HO-1, hemin, were able to induce the up-regulation of cucumber HO-1 gene (CsHO1) expression and thereafter the promotion of adventitious rooting in cucumber explants. The effect is specific for HO-1 since the potent HO-1 inhibitor zinc protoporphyrin IX (ZnPP) blocked the above responses triggered by CDH, and the inhibitory effects were reversed further when 30% saturation of CO aqueous solution was added together. Further, molecular evidence showed that CDH triggered the increases of the HO-1-mediated target genes responsible for adventitious rooting, including one DnaJ-like gene (CsDNAJ-1) and two calcium-dependent protein kinase (CDPK) genes (CsCDPK1 and CsCDPK5), and were inhibited by ZnPP and reversed by CO. The calcium (Ca2+) chelator ethylene glycol-bis (2-aminoethylether)-N,N,N',N'-tetraacetic acid (EGTA) and the Ca2+ channel blocker lanthanum chloride (LaCl3) not only compromised the induction of adventitious rooting induced by CDH but also decreased the transcripts of above three target genes. However, the application of ascorbic acid (AsA), a well-known antioxidant in plants, failed to exhibit similar inducible effect on adventitious root formation. In short, above results illustrated that the response of CDH in the induction of cucumber adventitious rooting might be through HO-1-dependent mechanism and calcium signaling. Physiological, pharmacological and molecular evidence showed that β-cyclodextrin-hemin complex (CDH) was able to induce cucumber adventitious rooting through heme oxygenase-1 (HO-1)-dependent mechanism and calcium signaling.

Expression and characterization of truncated human heme oxygenase (hHO-1) and a fusion protein of hHO-1 with human cytochrome P450 reductase.

Science.gov (United States)

Wilks, A; Black, S M; Miller, W L; Ortiz de Montellano, P R

1995-04-04

A human heme oxygenase (hHO-1) gene without the sequence coding for the last 23 amino acids has been expressed in Escherichia coli behind the pho A promoter. The truncated enzyme is obtained in high yields as a soluble, catalytically-active protein, making it available for the first time for detailed mechanistic studies. The purified, truncated hHO-1/heme complex is spectroscopically indistinguishable from that of the rat enzyme and converts heme to biliverdin when reconstituted with rat liver cytochrome P450 reductase. A self-sufficient heme oxygenase system has been obtained by fusing the truncated hHO-1 gene to the gene for human cytochrome P450 reductase without the sequence coding for the 20 amino acid membrane binding domain. Expression of the fusion protein in pCWori+ yields a protein that only requires NADPH for catalytic turnover. The failure of exogenous cytochrome P450 reductase to stimulate turnover and the insensitivity of the catalytic rate toward changes in ionic strength establish that electrons are transferred intramolecularly between the reductase and heme oxygenase domains of the fusion protein. The Vmax for the fusion protein is 2.5 times higher than that for the reconstituted system. Therefore, either the covalent tether does not interfere with normal docking and electron transfer between the flavin and heme domains or alternative but equally efficient electron transfer pathways are available that do not require specific docking.

Heme oxygenase-1: a metabolic nike.

Science.gov (United States)

Wegiel, Barbara; Nemeth, Zsuzsanna; Correa-Costa, Matheus; Bulmer, Andrew C; Otterbein, Leo E

2014-04-10

Heme degradation, which was described more than 30 years ago, is still very actively explored with many novel discoveries on its role in various disease models every year. The heme oxygenases (HO) are metabolic enzymes that utilize NADPH and oxygen to break apart the heme moiety liberating biliverdin (BV), carbon monoxide (CO), and iron. Heme that is derived from hemoproteins can be toxic to the cells and if not removed immediately, it causes cell apoptosis and local inflammation. Elimination of heme from the milieu enables generation of three products that influences numerous metabolic changes in the cell. CO has profound effects on mitochondria and cellular respiration and other hemoproteins to which it can bind and affect their function, while BV and bilirubin (BR), the substrate and product of BV, reductase, respectively, are potent antioxidants. Sequestration of iron into ferritin and its recycling in the tissues is a part of the homeodynamic processes that control oxidation-reduction in cellular metabolism. Further, heme is an important component of a number of metabolic enzymes, and, therefore, HO-1 plays an important role in the modulation of cellular bioenergetics. In this review, we describe the cross-talk between heme oxygenase-1 (HO-1) and its products with other metabolic pathways. HO-1, which we have labeled Nike, the goddess who personified victory, dictates triumph over pathophysiologic conditions, including diabetes, ischemia, and cancer.

Heme Oxygenase Induction Suppresses Hepatic Hepcidin and Rescues Ferroportin and Ferritin Expression in Obese Mice

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Nitin Puri

2017-01-01

Full Text Available Hepcidin, a phase II reactant secreted by hepatocytes, regulates cellular iron levels by increasing internalization of ferroportin-a transmembrane protein facilitating egress of cellular iron. Chronic low-grade inflammatory states, such as obesity, have been shown to increase oxidative stress and enhance hepcidin secretion from hepatocytes and macrophages. Heme-heme oxygenase (HO is a stress response system which reduces oxidative stress. We investigated the effects of HO-1 induction on hepatic hepcidin levels and on iron homeostasis in hepatic tissues from lean and obese mice. Obese mice exhibited hyperglycemia (p<0.05; increased levels of proinflammatory cytokines (MCP-1, IL-6, p<0.05; oxidative stress (p<0.05; and increased hepatic hepcidin levels (p<0.05. Enhancement of hepcidin was reflected in the reduced expression of ferroportin in obese mice (p<0.05. However, this effect is accompanied by a significant decline in ferritin expression. Additionally, there are reduced insulin receptor phosphorylation and attenuation of metabolic regulators pAMPK, pAKT, and pLKB1. Cobalt protoporphyrin- (CoPP- induced HO-1 upregulation in obese mice reversed these alterations (p<0.05, while attenuating hepatic hepcidin levels. These effects of CoPP were prevented in obese mice concurrently exposed to an inhibitor of HO (SnMP (p<0.05. Our results highlight a modulatory effect of HO on iron homeostasis mediated through the suppression of hepatic hepcidin.

Methamphetamine induces heme oxygenase-1 expression in cortical neurons and glia to prevent its toxicity

International Nuclear Information System (INIS)

Huang, Y.-N.; Wu, C.-H.; Lin, T.-C.; Wang, J.-Y.

2009-01-01

The impairment of cognitive and motor functions in humans and animals caused by methamphetamine (METH) administration underscores the importance of METH toxicity in cortical neurons. The heme oxygenase-1 (HO-1) exerts a cytoprotective effect against various neuronal injures; however, it remains unclear whether HO-1 is involved in METH-induced toxicity. We used primary cortical neuron/glia cocultures to explore the role of HO-1 in METH-induced toxicity. Exposure of cultured cells to various concentrations of METH (0.1, 0.5, 1, 3, 5, and 10 mM) led to cytotoxicity in a concentration-dependent manner. A METH concentration of 5 mM, which caused 50% of neuronal death and glial activation, was chosen for subsequent experiments. RT-PCR and Western blot analysis revealed that METH significantly induced HO-1 mRNA and protein expression, both preceded cell death. Double and triple immunofluorescence staining further identified HO-1-positive cells as activated astrocytes, microglia, and viable neurons, but not dying neurons. Inhibition of the p38 mitogen-activated protein kinase pathway significantly blocked HO-1 induction by METH and aggravated METH neurotoxicity. Inhibition of HO activity using tin protoporphyrine IX significantly reduced HO activity and exacerbated METH neurotoxicity. However, prior induction of HO-1 using cobalt protoporphyrine IX partially protected neurons from METH toxicity. Taken together, our results suggest that induction of HO-1 by METH via the p38 signaling pathway may be protective, albeit insufficient to completely protect cortical neurons from METH toxicity.

Effect of a heme oxygenase-1 inducer on NADPH oxidase ...

African Journals Online (AJOL)

Effect of a heme oxygenase-1 inducer on NADPH oxidase expression in ... and immunohistochemistry of hepatic NOX1 and NOX4 were investigated in week 4. ... (HO-1 inhibitor) administration caused upregulation of NOX gene expression ...

Inductive voltage adder (IVA) for submillimeter radius electron beam

International Nuclear Information System (INIS)

Mazarakis, M.G.; Poukey, J.W.; Maenchen, J.E.

1996-01-01

The authors have already demonstrated the utility of inductive voltage adder accelerators for production of small-size electron beams. In this approach, the inductive voltage adder drives a magnetically immersed foilless diode to produce high-energy (10--20 MeV), high-brightness pencil electron beams. This concept was first demonstrated with the successful experiments which converted the linear induction accelerator RADLAC II into an IVA fitted with a small 1-cm radius cathode magnetically immersed foilless diode (RADLAC II/SMILE). They present here first validations of extending this idea to mm-scale electron beams using the SABRE and HERMES-III inductive voltage adders as test beds. The SABRE experiments are already completed and have produced 30-kA, 9-MeV electron beams with envelope diameter of 1.5-mm FWHM. The HERMES-III experiments are currently underway

Transition between acute and chronic hepatotoxicity in mice is associated with impaired energy metabolism and induction of mitochondrial heme oxygenase-1.

Directory of Open Access Journals (Sweden)

Aniket Nikam

Full Text Available The formation of protein inclusions is frequently associated with chronic metabolic diseases. In mice, short-term intoxication with 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC leads to hepatocellular damage indicated by elevated serum liver enzyme activities, whereas only minor morphological changes are observed. Conversely, chronic administration of DDC for several weeks results in severe morphological damage, characterized by hepatocellular ballooning, disruption of the intermediate filament cytoskeleton, and formation of Mallory-Denk bodies consisting predominantly of misfolded keratins, Sqstm1/p62, and heat shock proteins. To evaluate the mechanistic underpinnings for this dichotomy we dissected the time-course of DDC intoxication for up to 10 weeks. We determined body weight change, serum liver enzyme activities, morphologic alterations, induction of antioxidant response (heme oxygenase-1, HO-1, oxidative damage and ATP content in livers as well as respiration, oxidative damage and the presence and activity of HO-1 in endoplasmic reticulum and mitochondria (mtHO-1. Elevated serum liver enzyme activity and oxidative liver damage were already present at early intoxication stages without further subsequent increase. After 2 weeks of intoxication, mice had transiently lost 9% of their body weight, liver ATP-content was reduced to 58% of controls, succinate-driven respiration was uncoupled from ATP-production and antioxidant response was associated with the appearance of catalytically active mtHO-1. Oxidative damage was associated with both acute and chronic DDC toxicity whereas the onset of chronic intoxication was specifically associated with mitochondrial dysfunction which was maximal after 2 weeks of intoxication. At this transition stage, adaptive responses involving mtHO-1 were induced, indirectly leading to improved respiration and preventing further drop of ATP levels. Our observations clearly demonstrate principally different

Dragon-I Linear Induction Electron Accelerator

International Nuclear Information System (INIS)

Ding Bonan; Deng Jianjun; Wang Huacen; Cheng Nian'an; Dai Guangsen; Zhang Linwen; Liu Chengjun; Zhang Wenwei; Li Jin; Zhang Kaizhi

2005-01-01

Dragon-I is a linear induction electron accelerator. This facility consists of a 3.6 MeV injector, 38 meter beam transport line and 16 MeV induction accelerator powered by high voltage generators, including 8 Marx generators and 48 Blumlein lines. This paper describes the physics design, development and experimental results of Dragon-I. The key technology is analyzed in the accelerator development, and the design requirements and operation of the major subsystems are presented. The experimental results show Dragon-I generates an 18-20 MeV, 2.5 kA, 70 ns electron beam. The X-ray spot size is about 1.2 mm and dose level about 0.103 C/kg at 1 meter. (authors)

Heme oxygenase-1 accelerates tumor angiogenesis of human pancreatic cancer.

Science.gov (United States)

Sunamura, Makoto; Duda, Dan G; Ghattas, Maivel H; Lozonschi, Lucian; Motoi, Fuyuhiko; Yamauchi, Jun-Ichiro; Matsuno, Seiki; Shibahara, Shigeki; Abraham, Nader G

2003-01-01

Angiogenesis is necessary for the continued growth of solid tumors, invasion and metastasis. Several studies clearly showed that heme oxygenase-1 (HO-1) plays an important role in angiogenesis. In this study, we used the vital microscope system, transparent skinfold model, lung colonization model and transduced pancreatic cancer cell line (Panc-1)/human heme oxygenase-1 (hHO-1) cells, to precisely analyze, for the first time, the effect of hHO-1 gene on tumor growth, angiogenesis and metastasis. Our results revealed that HO-1 stimulates angiogenesis of pancreatic carcinoma in severe combined immune deficient mice. Overexpression of human hHO-1 after its retroviral transfer into Panc-1 cells did not interfere with tumor growth in vitro. While in vivo the development of tumors was accelerated upon transfection with hHO-1. On the other hand, inhibition of heme oxygenase (HO) activity by stannous mesoporphyrin was able transiently to delay tumor growth in a dose dependent manner. Tumor angiogenesis was markedly increased in Panc-1/hHO-1 compared to mock transfected and wild type. Lectin staining and Ki-67 proliferation index confirmed these results. In addition hHO-1 stimulated in vitro tumor angiogenesis and increased endothelial cell survival. In a lung colonization model, overexpression of hHO-1 increased the occurrence of metastasis, while inhibition of HO activity by stannous mesoporphyrin completely inhibited the occurrence of metastasis. In conclusion, overexpression of HO-1 genes potentiates pancreatic cancer aggressiveness, by increasing tumor growth, angiogenesis and metastasis and that the inhibition of the HO system may be of useful benefit for the future treatment of the disease.

Heme Oxygenase-1 Inhibits HLA Class I Antibody-Dependent Endothelial Cell Activation.

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Eva Zilian

Full Text Available Antibody-mediated rejection (AMR is a key limiting factor for long-term graft survival in solid organ transplantation. Human leukocyte antigen (HLA class I (HLA I antibodies (Abs play a major role in the pathogenesis of AMR via their interactions with HLA molecules on vascular endothelial cells (ECs. The antioxidant enzyme heme oxygenase (HO-1 has anti-inflammatory functions in the endothelium. As complement-independent effects of HLA I Abs can activate ECs, it was the goal of the current study to investigate the role of HO-1 on activation of human ECs by HLA I Abs. In cell cultures of various primary human macro- and microvascular ECs treatment with monoclonal pan- and allele-specific HLA I Abs up-regulated the expression of inducible proinflammatory adhesion molecules and chemokines (vascular cell adhesion molecule-1 [VCAM-1], intercellular cell adhesion molecule-1 [ICAM-1], interleukin-8 [IL-8] and monocyte chemotactic protein 1 [MCP-1]. Pharmacological induction of HO-1 with cobalt-protoporphyrin IX reduced, whereas inhibition of HO-1 with either zinc-protoporphyrin IX or siRNA-mediated knockdown increased HLA I Ab-dependent up-regulation of VCAM-1. Treatment with two carbon monoxide (CO-releasing molecules, which liberate the gaseous HO product CO, blocked HLA I Ab-dependent EC activation. Finally, in an in vitro adhesion assay exposure of ECs to HLA I Abs led to increased monocyte binding, which was counteracted by up-regulation of HO-1. In conclusion, HLA I Ab-dependent EC activation is modulated by endothelial HO-1 and targeted induction of this enzyme may be a novel therapeutic approach for the treatment of AMR in solid organ transplantation.

Orthodontic forces induce the cytoprotective enzyme heme oxygenase-1 in rats

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Christiaan M. Suttorp

2016-07-01

Full Text Available Orthodontic forces disturb the microenvironment of the periodontal ligament (PDL, and induce craniofacial bone remodeling which is necessary for tooth movement. Unfortunately, orthodontic tooth movement is often hampered by ischemic injury and cell death within the PDL (hyalinization and root resorption. Large inter-individual differences in hyalinization and root resorption have been observed, and may be explained by differential protection against hyalization. Heme oxygenase-1 (HO-1 forms an important protective mechanism by breaking down heme into the strong anti-oxidants biliverdin/bilirubin and the signaling molecule carbon monoxide. These versatile HO-products protect against ischemic and inflammatory injury. We postulate that orthodontic forces induce HO-1 expression in the PDL during experimental tooth movement. Twenty-five 6-week-old male Wistar rats were used in this study. The upper three molars at one side were moved mesially using a Ni-Ti 10 cN coil spring. The contralateral side served as control. After 6, 12, 72, 96 and 120 hrs rats were killed. On parasagittal sections immunohistochemical staining was performed for analysis of HO-1 expression and quantification of multinuclear osteoclasts. Orthodontic force induced a significant time-dependent HO-1 expression in the mononuclear cell population within the PDL at both the apposition- and resorption side. Shortly after appliance placement HO-1 expression was highly induced in PDL cells but dropped to control levels within 72 hours. Some osteoclasts were HO-1 positive but this induction was shown to be independent of time- and mechanical stress. It is tempting to speculate that differential induction of cytoprotective enzymes as HO-1 in the PDL determines the level of hyalinization and, subsequently, fast and slow tooth movers during orthodontic treatment.

Orthodontic Forces Induce the Cytoprotective Enzyme Heme Oxygenase-1 in Rats

Science.gov (United States)

Suttorp, Christiaan M.; Xie, Rui; Lundvig, Ditte M. S.; Kuijpers-Jagtman, Anne Marie; Uijttenboogaart, Jasper Tom; Van Rheden, René; Maltha, Jaap C.; Wagener, Frank A. D. T. G.

2016-01-01

Orthodontic forces disturb the microenvironment of the periodontal ligament (PDL), and induce craniofacial bone remodeling which is necessary for tooth movement. Unfortunately, orthodontic tooth movement is often hampered by ischemic injury and cell death within the PDL (hyalinization) and root resorption. Large inter-individual differences in hyalinization and root resorption have been observed, and may be explained by differential protection against hyalinization. Heme oxygenase-1 (HO-1) forms an important protective mechanism by breaking down heme into the strong anti-oxidants biliverdin/bilirubin and the signaling molecule carbon monoxide. These versatile HO-1 products protect against ischemic and inflammatory injury. We postulate that orthodontic forces induce HO-1 expression in the PDL during experimental tooth movement. Twenty-five 6-week-old male Wistar rats were used in this study. The upper three molars at one side were moved mesially using a Nickel-Titanium coil spring, providing a continuous orthodontic force of 10 cN. The contralateral side served as control. After 6, 12, 72, 96, and 120 h groups of rats were killed. On parasagittal sections immunohistochemical staining was performed for analysis of HO-1 expression and quantification of osteoclasts. Orthodontic force induced a significant time-dependent HO-1 expression in mononuclear cells within the PDL at both the apposition- and resorption side. Shortly after placement of the orthodontic appliance HO-1 expression was highly induced in PDL cells but dropped to control levels within 72 h. Some osteoclasts were also HO-1 positive but this induction was shown to be independent of time- and mechanical stress. It is tempting to speculate that differential induction of tissue protecting- and osteoclast activating genes in the PDL determine the level of bone resorption and hyalinization and, subsequently, “fast” and “slow” tooth movers during orthodontic treatment. PMID:27486402

Orthodontic Forces Induce the Cytoprotective Enzyme Heme Oxygenase-1 in Rats.

Science.gov (United States)

Suttorp, Christiaan M; Xie, Rui; Lundvig, Ditte M S; Kuijpers-Jagtman, Anne Marie; Uijttenboogaart, Jasper Tom; Van Rheden, René; Maltha, Jaap C; Wagener, Frank A D T G

2016-01-01

Orthodontic forces disturb the microenvironment of the periodontal ligament (PDL), and induce craniofacial bone remodeling which is necessary for tooth movement. Unfortunately, orthodontic tooth movement is often hampered by ischemic injury and cell death within the PDL (hyalinization) and root resorption. Large inter-individual differences in hyalinization and root resorption have been observed, and may be explained by differential protection against hyalinization. Heme oxygenase-1 (HO-1) forms an important protective mechanism by breaking down heme into the strong anti-oxidants biliverdin/bilirubin and the signaling molecule carbon monoxide. These versatile HO-1 products protect against ischemic and inflammatory injury. We postulate that orthodontic forces induce HO-1 expression in the PDL during experimental tooth movement. Twenty-five 6-week-old male Wistar rats were used in this study. The upper three molars at one side were moved mesially using a Nickel-Titanium coil spring, providing a continuous orthodontic force of 10 cN. The contralateral side served as control. After 6, 12, 72, 96, and 120 h groups of rats were killed. On parasagittal sections immunohistochemical staining was performed for analysis of HO-1 expression and quantification of osteoclasts. Orthodontic force induced a significant time-dependent HO-1 expression in mononuclear cells within the PDL at both the apposition- and resorption side. Shortly after placement of the orthodontic appliance HO-1 expression was highly induced in PDL cells but dropped to control levels within 72 h. Some osteoclasts were also HO-1 positive but this induction was shown to be independent of time- and mechanical stress. It is tempting to speculate that differential induction of tissue protecting- and osteoclast activating genes in the PDL determine the level of bone resorption and hyalinization and, subsequently, "fast" and "slow" tooth movers during orthodontic treatment.

Heme oxygenase-1-mediated autophagy protects against pulmonary endothelial cell death and development of emphysema in cadmium-treated mice

Science.gov (United States)

Surolia, Ranu; Karki, Suman; Kim, Hyunki; Yu, Zhihong; Kulkarni, Tejaswini; Mirov, Sergey B.; Carter, A. Brent; Rowe, Steven M.; Matalon, Sadis; Thannickal, Victor J.; Agarwal, Anupam

2015-01-01

Pulmonary exposure to cadmium, a major component of cigarette smoke, has a dramatic impact on lung function and the development of emphysema. Cigarette smoke exposure induces heme oxygenase-1 (HO-1), a cytoprotective enzyme. In this study, we employed a truncated mouse model of emphysema by intratracheal instillation of cadmium (CdCl2) solution (0.025% per 1 mg/kg body wt) in HO-1+/+, HO-1−/−, and overexpressing humanized HO-1 bacterial artificial chromosome (hHO-1BAC) mice. We evaluated the role of HO-1 in cadmium-induced emphysema in mice by analyzing histopathology, micro-computed tomography scans, and lung function tests. CdCl2-exposed HO-1−/− mice exhibited more severe emphysema compared with HO-1+/+ or hHO-1BAC mice. Loss of pulmonary endothelial cells (PECs) from the alveolar capillary membrane is recognized to be a target in emphysema. PECs from HO-1+/+, HO-1−/−, and hHO-1BAC were employed to define the underlying molecular mechanism for the protection from emphysema by HO-1. Electron microscopy, expression of autophagic markers (microtubule-associated protein 1B-light chain 3 II, autophagy protein 5, and Beclin1) and apoptotic marker (cleaved caspase 3) suggested induction of autophagy and apoptosis in PECs after CdCl2 treatment. CdCl2-treated HO-1−/− PECs exhibited downregulation of autophagic markers and significantly increased cleaved caspase 3 expression and activity (∼4-fold higher). Moreover, hHO-1BAC PECs demonstrated upregulated autophagy and absence of cleaved caspase 3 expression or activity. Pretreatment of HO-1+/+ PECs with rapamycin induced autophagy and resulted in reduced cell death upon cadmium treatment. Induction of autophagy following CdCl2 treatment was found to be protective from apoptotic cell death. HO-1 induced protective autophagy in PECs and mitigated cadmium-induced emphysema. PMID:26071551

Heme oxygenase-1-mediated autophagy protects against pulmonary endothelial cell death and development of emphysema in cadmium-treated mice.

Science.gov (United States)

Surolia, Ranu; Karki, Suman; Kim, Hyunki; Yu, Zhihong; Kulkarni, Tejaswini; Mirov, Sergey B; Carter, A Brent; Rowe, Steven M; Matalon, Sadis; Thannickal, Victor J; Agarwal, Anupam; Antony, Veena B

2015-08-01

Pulmonary exposure to cadmium, a major component of cigarette smoke, has a dramatic impact on lung function and the development of emphysema. Cigarette smoke exposure induces heme oxygenase-1 (HO-1), a cytoprotective enzyme. In this study, we employed a truncated mouse model of emphysema by intratracheal instillation of cadmium (CdCl2) solution (0.025% per 1 mg/kg body wt) in HO-1(+/+), HO-1(-/-), and overexpressing humanized HO-1 bacterial artificial chromosome (hHO-1BAC) mice. We evaluated the role of HO-1 in cadmium-induced emphysema in mice by analyzing histopathology, micro-computed tomography scans, and lung function tests. CdCl2-exposed HO-1(-/-) mice exhibited more severe emphysema compared with HO-1(+/+) or hHO-1BAC mice. Loss of pulmonary endothelial cells (PECs) from the alveolar capillary membrane is recognized to be a target in emphysema. PECs from HO-1(+/+), HO-1(-/-), and hHO-1BAC were employed to define the underlying molecular mechanism for the protection from emphysema by HO-1. Electron microscopy, expression of autophagic markers (microtubule-associated protein 1B-light chain 3 II, autophagy protein 5, and Beclin1) and apoptotic marker (cleaved caspase 3) suggested induction of autophagy and apoptosis in PECs after CdCl2 treatment. CdCl2-treated HO-1(-/-) PECs exhibited downregulation of autophagic markers and significantly increased cleaved caspase 3 expression and activity (∼4-fold higher). Moreover, hHO-1BAC PECs demonstrated upregulated autophagy and absence of cleaved caspase 3 expression or activity. Pretreatment of HO-1(+/+) PECs with rapamycin induced autophagy and resulted in reduced cell death upon cadmium treatment. Induction of autophagy following CdCl2 treatment was found to be protective from apoptotic cell death. HO-1 induced protective autophagy in PECs and mitigated cadmium-induced emphysema. Copyright © 2015 the American Physiological Society.

Heme oxygenase-1 prevents hyperthyroidism induced hepatic damage via an antioxidant and antiapoptotic pathway.

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Giriş, Murat; Erbil, Yeşim; Depboylu, Bilge; Mete, Ozgür; Türkoğlu, Umit; Abbasoğlu, Semra Doğru; Uysal, Müjdat

2010-12-01

The exact pathogenesis of hepatic dysfunction in hyperthyroidism is still unknown. We aimed to investigate the pathogenesis of liver dysfunction caused by hyperthyroidism through inducing heme oxygenase-1 (HO-1) expression, which has antioxidant and anti-apoptotic properties. Rats were divided into six groups: untreated (group 1), treated with zinc protoporphyrin (ZnPP) (group 2), treated with hemin (group 3), treated with tri-iodothyronine (T3) (group 4), treated with T3 and ZnPP (group 5), and treated with T3 and hemin (group 6). After 22 d, oxidative stress and antioxidant enzymes and the expression of HO-1, mitochondrial permeability transition, cytochrome c, Bax, Bcl-2, caspase-3, caspase-8, and caspase-3 activity, and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) assay were examined. Hyperthyroidism induced oxidative stress of liver tissue was ameliorated by HO-1 induction. Administration of hemin (HO-1 inducer) increased Bcl-2 expression. Decreased expression of cytochrome c was accompanied by a decrease in caspase-3, caspase-8, Bax expression, and caspase-3 activity. The apoptotic activity and oxidative damage were found to be increased by the administration of ZnPP (HO-1 inhibitor). Immunohistochemistry findings supported these results. HO-1 induction plays a protective role in the pathogenesis of the liver dysfunction in hyperthyroidism. This effect is dependent on modulation of the antiapoptotic and antioxidative pathways by HO-1 expression. Copyright © 2010 Elsevier Inc. All rights reserved.

Experimental research of double-pulse linear induction electron accelerator

International Nuclear Information System (INIS)

Liao Shuqing; Cheng Cheng; Zheng Shuxin; Tang Chuanxiang; Lin Yuzheng; Jing Xiaobing; Mu Fan; Pan Haifeng

2009-01-01

The Mini-LIA is a double-pulse linear induction electron accelerator with megahertz repetition rates, which consists of a double-pulse power system, a thermal cathode electron gun, two induction cells, beam transportation systems and diagnosis systems, etc. Experiments of the Mini-LIA have been conducted. The double-pulse high voltage was obtained with several hundred nanosecond pulse intervals (i. e. megahertz repetition rate) and each pulse had an 80 kV amplitude with a FWHM of 80 ns. In the gap of the induction cell, the double-pulse accelerating electric field was measured via E-field probes, and the double-pulse electron beam with a current about 1.1 A has been obtained at the Mini-LIA exit. These experimental results show that the double-pulse high voltage with megahertz repetition rates can be generated by an insulation and junction system. And they also indicate that the induction cell with metglas as the ferromagnetic material and the LaB 6 thermal cathode electron gun suit the double-pulse operation with megahertz repetition rates. (authors)

Management of oxidative stress by heme oxygenase-1 in cisplatin-induced toxicity in renal tubular cells.

Science.gov (United States)

Schaaf, G J; Maas, R F M; de Groene, E M; Fink-Gremmels, J

2002-08-01

Induction of heme oxygenase-1 (HO-1) may serve as an immediate protective response during treatment with the cytostatic drug cisplatin (CDDP). Oxidative pathways participate in the characteristic nephrotoxicity of CDDP. In the present study, cultured tubular cells (LLC-PK1) were used to investigate whether induction of HO provided protection against CDDP by maintaining the cellular redox balance. The antioxidants, alpha-tocopherol (TOCO) and N-acetylcysteine (NAC), were used to demonstrate that elevation of ROS levels contribute to the development of CDDP-induced cytotoxicity. Chemical modulators of HO activity were used to investigate the role of HO herein. Hemin was used to specifically induce HO-1, while exposure of the cells to tin-protoporphyrin (SnPP) was shown to inhibit HO activity. Hemin treatment prior to CDDP-exposure significantly decreased the generation of ROS to control levels, while inhibition of HO increased the ROS levels beyond the levels measured in cells treated with CDDP alone. Furthermore, HO induction protected significantly against the cytotoxicity of CDDP, although this protection was limited. Similar results were obtained when the cells were preincubated with TOCO, suggesting that mechanisms other than impairment of the redox ratio are important in CDDP-induced loss of cell viability in vitro. In addition, SnPP treatment exacerbated the oxidative response and cytotoxicity of CDDP, especially at low CDDP concentrations. We therefore conclude that HO is able to directly limit the CDDP-induced oxidative stress response and thus serves as safeguard of the cellular redox balance.

In vitro studies on heme oxygenase-1 and P24 antigen HIV-1 level ...

African Journals Online (AJOL)

Background: Heme oxygenase-1 (HO-1) is a protein secreted by immune cells as a part of immune response mechanism.HO-1 can be induced by variety agents that causingoxidative stress, such as exposure to 100% oxygenat2,4 ATA pressure.It plays a vital role in maintaining cellular homeostasis.This study was ...

The haptoglobin-CD163-heme oxygenase-1 pathway for hemoglobin scavenging

DEFF Research Database (Denmark)

Thomsen, Jens Haugbølle; Etzerodt, Anders; Svendsen, Pia

2013-01-01

The haptoglobin- (Hp-) CD163-heme oxygenase-1 (HO-1) pathway is an efficient captor-receptor-enzyme system to circumvent the hemoglobin (Hb)/heme-induced toxicity during physiological and pathological hemolyses. In this pathway, Hb tightly binds to Hp leading to CD163-mediated uptake of the complex...

Structure-Activity Relationships of 1,2-Disubstituted Benzimidazoles: Selective Inhibition of Heme Oxygenase-2 Activity.

Science.gov (United States)

Kong, Xianqi; Vukomanovic, Dragic; Nakatsu, Kanji; Szarek, Walter A

2015-08-01

Devising ways to up- or down-regulate heme oxygenase activity is attracting much interest as a strategy for the treatment of a variety of disorders. With a view of obtaining compounds that exhibit high potency and selectivity as inhibitors of the heme oxygenase-2 (HO-2) isozyme (constitutive) relative to the heme oxygenase-1 (HO-1) isozyme (inducible), several 1,2-disubstituted 1H-benzimidazoles were designed and synthesized. Specifically, analogues were synthesized in which the C2 substituent was the following: (1H-imidazol-1-yl)methyl, (N-morpholinyl)methyl, cyclopentylmethyl, cyclohexylmethyl, or (norborn-2-yl)methyl. Compounds with the cyclic system in the C2 substituent being a carbocyclic ring, especially cyclohexyl or norborn-2-yl, and the N1 substituent being a ring-substituted benzyl group, especially 4-chlorobenzyl or 4-bromobenzyl, best exhibited the target criteria of high potency and selectivity toward inhibition of HO-2. The new candidates should be useful pharmacological tools and may have therapeutic applications. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Functional imaging: monitoring heme oxygenase-1 gene expression in vivo

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Zhang, Weisheng; Reilly-Contag, Pamela; Stevenson, David K.; Contag, Christopher H.

1999-07-01

The regulation of genetic elements can be monitored in living animals using photoproteins as reporters. Heme oxygenase (HO) is the key catabolic enzyme in the heme degradation pathway. Here, HO expression serves as a model for in vivo functional imaging of transcriptional regulation of a clinically relevant gene. HO enzymatic activity is inhibited by heme analogs, metalloporphyrins, but many members of this family of compounds also activate transcription of the HO-1 promoter. The degree of transcriptional activation by twelve metalloporphyrins, differing at the central metal and porphyrin ring substituents, was evaluated in both NIH 3T3 stable lines and transgenic animals containing HO-1 promoter-luciferase gene fusions. In the correlative cell culture assays, the metalloporphyrins increased transcription form the full length HO promoter fusion to varying degrees, but none increased transcription from a truncated HO-1 promoter. These results suggested that one or both of the two distal enhancer elements located at -4 and -10 Kb upstream from transcriptional start are required for HO-1 induction by heme and its analogs. The full-length HO-1-luc fusion was then evaluated as a transgene in mice. It was possible to monitor the effects of the metalloporphyrins, SnMP and ZnPP, in living animals over time. This spatiotemporal analyses of gene expression in vivo implied that alterations in porphyrin ring substituents and the central metal may affect the extent of gene activation. These data further indicate that using photoprotein reporters, subtle differences in gene expression can be monitored in living animals.

Effect of heme oxygenase-1 on radiation-induced skin injury

International Nuclear Information System (INIS)

Song Chuanjun; Meng Xingjun; Xie Ling; Chen Qing; Zhou Jundong; Zhang Shuyu; Wu Jinchang

2012-01-01

Objective: To investigate the effect of heme oxygenase-1 (HO-1) on the acute radiation-induced skin injury by gene transfer. Methods: Thirty-three male SD rats were randomly divided into three groups as PBS-injected group, Ad-EGFP-injected group and Ad-HO-1-injected group (n=11). In each group, three rats were used for determining the expression of target gene and the other rats were irradiated on the buttock skin with 40 Gy electron beam generated by a linear accelerator. Immediately after irradiation, rats were administered with a subcutaneous injection of PBS, Ad-EGFP or Ad-HO-1, respectively. Subsequently, the skin reactions were measured twice a week using the semi-quantitative skin injury scale. Results: The strong positive expression of HO-1 was observed in subcutaneous dermal tissue after injection of Ad-HO-1. Compared to the PBS-injected group or the Ad-EGFP-injected group, a significant mitigation of skin injury was observed in Ad-HO-1-injected mice 14 d after irradiation (q=0.000-0.030, P<0.05). Conclusions: HO-1 could significantly mitigate radiation-induced acute skin injury and Ad-HO-1 could be used to treat radiation-induced skin injury. (authors)

Characterization of docosahexaenoic acid (DHA)-induced heme oxygenase-1 (HO-1) expression in human cancer cells: the importance of enhanced BTB and CNC homology 1 (Bach1) degradation.

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Wang, Shuai; Hannafon, Bethany N; Wolf, Roman F; Zhou, Jundong; Avery, Jori E; Wu, Jinchang; Lind, Stuart E; Ding, Wei-Qun

2014-05-01

The effect of docosahexaenoic acid (DHA) on heme oxygenase-1 (HO-1) expression in cancer cells has never been characterized. This study examines DHA-induced HO-1 expression in human cancer cell model systems. DHA enhanced HO-1 gene expression in a time- and concentration-dependent manner, with maximal induction at 21 h of treatment. This induction of HO-1 expression was confirmed in vivo using a xenograft nude mouse model fed a fish-oil-enriched diet. The increase in HO-1 gene transcription induced by DHA was significantly attenuated by the antioxidant N-acetyl cysteine, suggesting the involvement of oxidative stress. This was supported by direct measurement of lipid peroxide levels after DHA treatment. Using a human HO-1 gene promoter reporter construct, we identified two antioxidant response elements (AREs) that mediate the DHA-induced increase in HO-1 gene transcription. Knockdown of nuclear factor (erythroid-derived 2)-like 2 (Nrf2) expression compromised the DHA-induced increase in HO-1 gene transcription, indicating the importance of the Nrf2 pathway in this event. However, the nuclear protein levels of Nrf2 remained unchanged upon DHA treatment. Further studies demonstrated that DHA reduces nuclear Bach1 protein expression by promoting its degradation and attenuates Bach1 binding to the AREs in the HO-1 gene promoter. In contrast, DHA enhanced Nrf2 binding to the AREs without affecting nuclear Nrf2 expression levels, indicating a new cellular mechanism that mediates DHA's induction of HO-1 gene transcription. To our knowledge, this is the first characterization of DHA-induced HO-1 expression in human malignant cells. Copyright © 2014 Elsevier Inc. All rights reserved.

Characterization of arene di-oxygenases involved in polycyclic aromatic hydrocarbons biodegradation in Mycobacterium sp. 6PY1; Caracterisation d'arene dioxygenases impliquees dans la biodegradation des hydrocarbures aromatiques polycycliques chez Mycobacterium sp. 6PY1

Energy Technology Data Exchange (ETDEWEB)

Kuony, S.

2005-06-15

similar in sequence to that encoding Pdo1, suggesting that both isoenzymes are able two oxidize pyrene. In order to function, the ring-hydroxylating di-oxygenases require two electron-transfer proteins: a ferredoxin and a reductase. The electron carriers associated to Pdo1 and Pdo2 were not identified. However, the activity of the two di-oxygenases was stimulated in vivo by co-expressing accessory genes recruited from other bacteria. Finally, immuno-detection experiments using specific antibodies showed that the enzymes Pdo1 and Pdo2 were co-induced in the presence of PAHs, but differentially regulated according to growth conditions. (author)

Generation and characterization of human heme oxygenase-1 transgenic pigs.

Directory of Open Access Journals (Sweden)

Hye-Jung Yeom

Full Text Available Xenotransplantation using transgenic pigs as an organ source is a promising strategy to overcome shortage of human organ for transplantation. Various genetic modifications have been tried to ameliorate xenograft rejection. In the present study we assessed effect of transgenic expression of human heme oxygenase-1 (hHO-1, an inducible protein capable of cytoprotection by scavenging reactive oxygen species and preventing apoptosis caused by cellular stress during inflammatory processes, in neonatal porcine islet-like cluster cells (NPCCs. Transduction of NPCCs with adenovirus containing hHO-1 gene significantly reduced apoptosis compared with the GFP-expressing adenovirus control after treatment with either hydrogen peroxide or hTNF-α and cycloheximide. These protective effects were diminished by co-treatment of hHO-1 antagonist, Zinc protoporphyrin IX. We also generated transgenic pigs expressing hHO-1 and analyzed expression and function of the transgene. Human HO-1 was expressed in most tissues, including the heart, kidney, lung, pancreas, spleen and skin, however, expression levels and patterns of the hHO-1 gene are not consistent in each organ. We isolate fibroblast from transgenic pigs to analyze protective effect of the hHO-1. As expected, fibroblasts derived from the hHO-1 transgenic pigs were significantly resistant to both hydrogen peroxide damage and hTNF-α and cycloheximide-mediated apoptosis when compared with wild-type fibroblasts. Furthermore, induction of RANTES in response to hTNF-α or LPS was significantly decreased in fibroblasts obtained from the hHO-1 transgenic pigs. These findings suggest that transgenic expression of hHO-1 can protect xenografts when exposed to oxidative stresses, especially from ischemia/reperfusion injury, and/or acute rejection mediated by cytokines. Accordingly, hHO-1 could be an important candidate molecule in a multi-transgenic pig strategy for xenotransplantation.

Generation and characterization of human heme oxygenase-1 transgenic pigs.

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Yeom, Hye-Jung; Koo, Ok Jae; Yang, Jaeseok; Cho, Bumrae; Hwang, Jong-Ik; Park, Sol Ji; Hurh, Sunghoon; Kim, Hwajung; Lee, Eun Mi; Ro, Han; Kang, Jung Taek; Kim, Su Jin; Won, Jae-Kyung; O'Connell, Philip J; Kim, Hyunil; Surh, Charles D; Lee, Byeong-Chun; Ahn, Curie

2012-01-01

Xenotransplantation using transgenic pigs as an organ source is a promising strategy to overcome shortage of human organ for transplantation. Various genetic modifications have been tried to ameliorate xenograft rejection. In the present study we assessed effect of transgenic expression of human heme oxygenase-1 (hHO-1), an inducible protein capable of cytoprotection by scavenging reactive oxygen species and preventing apoptosis caused by cellular stress during inflammatory processes, in neonatal porcine islet-like cluster cells (NPCCs). Transduction of NPCCs with adenovirus containing hHO-1 gene significantly reduced apoptosis compared with the GFP-expressing adenovirus control after treatment with either hydrogen peroxide or hTNF-α and cycloheximide. These protective effects were diminished by co-treatment of hHO-1 antagonist, Zinc protoporphyrin IX. We also generated transgenic pigs expressing hHO-1 and analyzed expression and function of the transgene. Human HO-1 was expressed in most tissues, including the heart, kidney, lung, pancreas, spleen and skin, however, expression levels and patterns of the hHO-1 gene are not consistent in each organ. We isolate fibroblast from transgenic pigs to analyze protective effect of the hHO-1. As expected, fibroblasts derived from the hHO-1 transgenic pigs were significantly resistant to both hydrogen peroxide damage and hTNF-α and cycloheximide-mediated apoptosis when compared with wild-type fibroblasts. Furthermore, induction of RANTES in response to hTNF-α or LPS was significantly decreased in fibroblasts obtained from the hHO-1 transgenic pigs. These findings suggest that transgenic expression of hHO-1 can protect xenografts when exposed to oxidative stresses, especially from ischemia/reperfusion injury, and/or acute rejection mediated by cytokines. Accordingly, hHO-1 could be an important candidate molecule in a multi-transgenic pig strategy for xenotransplantation.

Heme oxygenase is the major 32-kDa stress protein induced in human skin fibroblasts by UVA radiation, hydrogen peroxide, and sodium arsenite

International Nuclear Information System (INIS)

Keyse, S.M.; Tyrrell, R.M.

1989-01-01

We have shown that UVA (320-380 nm) radiation, hydrogen peroxide, and sodium arsenite induce a stress protein of approximately 32 kDa in human skin fibroblasts. The synthesis and cloning of cDNA from arsenite-induced mRNA populations have now allowed us to unequivocally identify the 32-kDa protein as heme oxygenase. By mRNA analysis we have shown that the heme oxygenase gene is also induced in cultured human skin fibroblasts by UVA radiation, hydrogen peroxide, cadmium chloride, iodoacetamide, and menadione. The known antioxidant properties of heme catabolites taken together with the observation of a high level of induction of the enzyme in cells from an organ not involved in hemoglobin breakdown strongly supports the proposal that the induction of heme oxygenase may be a general response to oxidant stress and constitutes an important cellular defense mechanism against oxidative damage

Selective activation of heme oxygenase-2 by menadione.

Science.gov (United States)

Vukomanovic, Dragic; McLaughlin, Brian E; Rahman, Mona N; Szarek, Walter A; Brien, James F; Jia, Zongchao; Nakatsu, Kanji

2011-11-01

While substantial progress has been made in elucidating the roles of heme oxygenases-1 (HO-1) and -2 (HO-2) in mammals, our understanding of the functions of these enzymes in health and disease is still incomplete. A significant amount of our knowledge has been garnered through the use of nonselective inhibitors of HOs, and our laboratory has recently described more selective inhibitors for HO-1. In addition, our appreciation of HO-1 has benefitted from the availability of tools for increasing its activity through enzyme induction. By comparison, there is a paucity of information about HO-2 activation, with only a few reports appearing in the literature. This communication describes our observations of the up to 30-fold increase in the in-vitro activation of HO-2 by menadione. This activation was due to an increase in Vmax and was selective, in that menadione did not increase HO-1 activity.

Transgenic expression of human heme oxygenase-1 in pigs confers resistance against xenograft rejection during ex vivo perfusion of porcine kidneys.

Science.gov (United States)

Petersen, Björn; Ramackers, Wolf; Lucas-Hahn, Andrea; Lemme, Erika; Hassel, Petra; Queisser, Anna-Lisa; Herrmann, Doris; Barg-Kues, Brigitte; Carnwath, Joseph W; Klose, Johannes; Tiede, Andreas; Friedrich, Lars; Baars, Wiebke; Schwinzer, Reinhard; Winkler, Michael; Niemann, Heiner

2011-01-01

The major immunological hurdle to successful porcine-to-human xenotransplantation is the acute vascular rejection (AVR), characterized by endothelial cell (EC) activation and perturbation of coagulation. Heme oxygenase-1 (HO-1) and its derivatives have anti-apoptotic, anti-inflammatory effects and protect against reactive oxygen species, rendering HO-1 a promising molecule to control AVR. Here, we report the production and characterization of pigs transgenic for human heme oxygenase-1 (hHO-1) and demonstrate significant protection in porcine kidneys against xenograft rejection in ex vivo perfusion with human blood and transgenic porcine aortic endothelial cells (PAEC) in a TNF-α-mediated apoptosis assay. Transgenic and non-transgenic PAEC were tested in a TNF-α-mediated apoptosis assay. Expression of adhesion molecules (ICAM-1, VCAM-1, and E-selectin) was measured by real-time PCR. hHO-1 transgenic porcine kidneys were perfused with pooled and diluted human AB blood in an ex vivo perfusion circuit. MHC class-II up-regulation after induction with IFN-γ was compared between wild-type and hHO-1 transgenic PAEC. Cloned hHO-1 transgenic pigs expressed hHO-1 in heart, kidney, liver, and in cultured ECs and fibroblasts. hHO-1 transgenic PAEC were protected against TNF-α-mediated apoptosis. Real-time PCR revealed reduced expression of adhesion molecules like ICAM-1, VCAM-1, and E-selectin. These effects could be abrogated by the incubation of transgenic PAECs with the specific HO-1 inhibitor zinc protoporphorine IX (Zn(II)PPIX, 20 μm). IFN-γ induced up-regulation of MHC class-II molecules was significantly reduced in PAECs from hHO-1 transgenic pigs. hHO-1 transgenic porcine kidneys could successfully be perfused with diluted human AB-pooled blood for a maximum of 240 min (with and without C1 inh), while in wild-type kidneys, blood flow ceased after ∼60 min. Elevated levels of d-Dimer and TAT were detected, but no significant consumption of fibrinogen and

Heme oxygenase-1 expression protects the heart from acute injury caused by inducible Cre recombinase.

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Hull, Travis D; Bolisetty, Subhashini; DeAlmeida, Angela C; Litovsky, Silvio H; Prabhu, Sumanth D; Agarwal, Anupam; George, James F

2013-08-01

The protective effect of heme oxygenase-1 (HO-1) expression in cardiovascular disease has been previously demonstrated using transgenic animal models in which HO-1 is constitutively overexpressed in the heart. However, the temporal requirements for protection by HO-1 induction relative to injury have not been investigated, but are essential to employ HO-1 as a therapeutic strategy in human cardiovascular disease states. Therefore, we generated mice with cardiac-specific, tamoxifen (TAM)-inducible overexpression of a human HO-1 (hHO-1) transgene (myosin heavy chain (MHC)-HO-1 mice) by breeding mice with cardiac-specific expression of a TAM-inducible Cre recombinase (MHC-Cre mice), with mice containing an hHO-1 transgene preceded by a floxed-stop signal. MHC-HO-1 mice overexpress HO-1 mRNA and the enzymatically active protein following TAM administration (40 mg/kg body weight on 2 consecutive days). In MHC-Cre controls, TAM administration leads to severe, acute cardiac toxicity, cardiomyocyte necrosis, and 80% mortality by day 3. This cardiac toxicity is accompanied by a significant increase in inflammatory cells in the heart that are predominantly neutrophils. In MHC-HO-1 mice, HO-1 overexpression ameliorates the depression of cardiac function and high mortality rate observed in MHC-Cre mice following TAM administration and attenuates cardiomyocyte necrosis and neutrophil infiltration. These results highlight that HO-1 induction is sufficient to prevent the depression of cardiac function observed in mice with TAM-inducible Cre recombinase expression by protecting the heart from necrosis and neutrophil infiltration. These findings are important because MHC-Cre mice are widely used in cardiovascular research despite the limitations imposed by Cre-induced cardiac toxicity, and also because inflammation is an important pathological component of many human cardiovascular diseases.

In vitro Activation of heme oxygenase-2 by menadione and its analogs.

Science.gov (United States)

Vukomanovic, Dragic; Rahman, Mona N; Bilokin, Yaroslav; Golub, Andriy G; Brien, James F; Szarek, Walter A; Jia, Zongchao; Nakatsu, Kanji

2014-02-18

Previously, we reported that menadione activated rat, native heme oxygenase-2 (HO-2) and human recombinant heme oxygenase-2 selectively; it did not activate spleen, microsomal heme oxygenase-1. The purpose of this study was to explore some structure-activity relationships of this activation and the idea that redox properties may be an important aspect of menadione efficacy. Heme oxygenase activity was determined in vitro using rat spleen and brain microsomes as the sources of heme oxygenase-1 and -2, respectively, as well as recombinant, human heme oxygenase-2. Menadione analogs with bulky aliphatic groups at position-3, namely vitamins K1 and K2, were not able to activate HO-2. In contrast, several compounds with similar bulky but less lipophilic moieties at position-2 (and -3) were able to activate HO-2 many fold; these compounds included polar, rigid, furan-containing naphthoquinones, furan-benzoxazine naphthoquinones, 2-(aminophenylphenyl)-3-piperidin-1-yl naphthoquinones. To explore the idea that redox properties might be involved in menadione efficacy, we tested analogs such as 1,4-dimethoxy-2-methylnaphthalene, pentafluoromenadione, monohalogenated naphthoquinones, α-tetralone and 1,4-naphthoquinone. All of these compounds were inactive except for 1,4-naphthoquinone. Menadione activated full-length recombinant human heme oxygenase-2 (FL-hHO-2) as effectively as rat brain enzyme, but it did not activate rat spleen heme oxygenase. These observations are consistent with the idea that naphthoquinones such as menadione bind to a receptor in HO-2 and activate the enzyme through a mechanism that may involve redox properties.

AN ELISA ASSAY FOR HEME OXYGENASE (HO-1)

Science.gov (United States)

An ELISA assay for heme oxygenase (HO-l ) Abstract A double antibody capture ELISA for the HO-l protein has been developed to separately quantitate HO-I protein. The use of 2.5% NP40 detergent greatly assists in freeing HO-l protein from membranes and/or other cel...

Omeprazole induces heme oxygenase-1 in fetal human pulmonary microvascular endothelial cells via hydrogen peroxide-independent Nrf2 signaling pathway

International Nuclear Information System (INIS)

Patel, Ananddeep; Zhang, Shaojie; Shrestha, Amrit Kumar; Maturu, Paramahamsa; Moorthy, Bhagavatula; Shivanna, Binoy

2016-01-01

Omeprazole (OM) is an aryl hydrocarbon receptor (AhR) agonist and a proton pump inhibitor that is used to treat humans with gastric acid related disorders. Recently, we showed that OM induces NAD (P) H quinone oxidoreductase-1 (NQO1) via nuclear factor erythroid 2-related factor 2 (Nrf2)-dependent mechanism. Heme oxygenase-1 (HO-1) is another cytoprotective and antioxidant enzyme that is regulated by Nrf2. Whether OM induces HO-1 in fetal human pulmonary microvascular endothelial cells (HPMEC) is unknown. Therefore, we tested the hypothesis that OM will induce HO-1 expression via Nrf2 in HPMEC. OM induced HO-1 mRNA and protein expression in a dose-dependent manner. siRNA-mediated knockdown of AhR failed to abrogate, whereas knockdown of Nrf2 abrogated HO-1 induction by OM. To identify the underlying molecular mechanisms, we determined the effects of OM on cellular hydrogen peroxide (H 2 O 2 ) levels since oxidative stress mediated by the latter is known to activate Nrf2. Interestingly, the concentration at which OM induced HO-1 also increased H 2 O 2 levels. Furthermore, H 2 O 2 independently augmented HO-1 expression. Although N-acetyl cysteine (NAC) significantly decreased H 2 O 2 levels in OM-treated cells, we observed that OM further increased HO-1 mRNA and protein expression in NAC-pretreated compared to vehicle-pretreated cells, suggesting that OM induces HO-1 via H 2 O 2 -independent mechanisms. In conclusion, we provide evidence that OM transcriptionally induces HO-1 via AhR - and H 2 O 2 - independent, but Nrf2 - dependent mechanisms. These results have important implications for human disorders where Nrf2 and HO-1 play a beneficial role. - Highlights: • Omeprazole induces HO-1 in human fetal lung cells. • AhR deficiency fails to abrogate omeprazole-mediated induction of HO-1. • Nrf2 knockdown abrogates omeprazole-mediated HO-1 induction in human lung cells. • Hydrogen peroxide depletion augments omeprazole-mediated induction of HO-1.

Rapamycin Induces Heme Oxygenase-1 in Liver but Inhibits Bile Flow Recovery after Ischemia

NARCIS (Netherlands)

Kist, Alwine; Wakkie, Joris; Madu, Max; Versteeg, Ruth; ten Berge, Judith; Nikolic, Andrej; Nieuwenhuijs, Vincent B.; Porte, Robert J.; Padbury, Robert T. A.; Barritt, Greg J.

Background/Aims. Rapamycin, which is employed in the management of patients undergoing liver surgery, induces the synthesis of heme oxygenase-1 (HO-1) in some non-liver cell types. The aim was to investigate whether rapamycin can induce HO-1 expression in the liver, and to test the effects of

Heme oxygenase-1 comes back to endoplasmic reticulum

Energy Technology Data Exchange (ETDEWEB)

Kim, Hong Pyo [School of Biological Sciences, Ulsan University (Korea, Republic of); Pae, Hyun-Ock [Department of Immunology, Wonkwang University School of Medicine (Korea, Republic of); Back, Sung Hun; Chung, Su Wol [School of Biological Sciences, Ulsan University (Korea, Republic of); Woo, Je Moon [Department of Opthalmology, Ulasn University Hospital (Korea, Republic of); Son, Yong [Department of Anesthesiology and Pain Medicine, Wonkwang University School of Medicine (Korea, Republic of); Chung, Hun-Taeg, E-mail: chung@ulsan.ac.kr [School of Biological Sciences, Ulsan University (Korea, Republic of)

2011-01-07

Research highlights: {yields} Although multiple compartmentalization of HO-1 has been documented, the functional implication of this enzyme at these subcellular organelles is only partially elucidated. {yields} HO-1 expression at ER is induced by a diverse set of conditions that cause ER stressors. {yields} CO may induce HO-1 expression in human ECs by activating Nrf2 through PERK phosphorylation in a positive-feedback manner. {yields} ER-residing HO-1 and its cytoprotective activity against ER stress is discussed. -- Abstract: Originally identified as a rate-limiting enzyme for heme catabolism, heme oxygenase-1 (HO-1) has expanded its roles in anti-inflammation, anti-apoptosis and anti-proliferation for the last decade. Regulation of protein activity by location is well appreciated. Even though multiple compartmentalization of HO-1 has been documented, the functional implication of this enzyme at these subcellular organelles is only partially elucidated. In this review we discuss the endoplasmic reticulum (ER)-residing HO-1 and its cytoprotective activity against ER stress.

Beneficial effect of prolonged heme oxygenase 1 activation in a rat model of chronic heart failure

Directory of Open Access Journals (Sweden)

Massimo Collino

2013-07-01

We and others have previously demonstrated that heme oxygenase 1 (HO-1 induction by acute hemin administration exerts cardioprotective effects. Here, we developed a rat model of heart failure to investigate whether a long-term induction of HO-1 by chronic hemin administration exerted protective effects. Sprague Dawley rats that underwent permanent ligation of the left coronary artery were closely monitored for survival rate analysis and sacrificed on day 28 post-operation. Administration of hemin (4 mg/kg body weight every other day for 4 weeks induced a massive increase in HO-1 expression and activity, as shown by the increased levels of the two main metabolic products of heme degradation, bilirubin and carbon monoxide (CO. These effects were associated with significant improvement in survival and reduced the extension of myocardial damage. The ischemic hearts of the hemin-treated animals displayed reduced oxidative stress and apoptosis in comparison with the non-treated rats, as shown by the decreased levels of lipid peroxidation, free-radical-induced DNA damage, caspase-3 activity and Bax expression. Besides, chronic HO-1 activation suppressed the elevated levels of myeloperoxidase (MPO activity, interleukin 1β (IL-1β production and tumor necrosis factor-α (TNFα production that were evoked by the ischemic injury, and increased the plasma level of the anti-inflammatory cytokine IL-10. Interestingly, HO-1 inhibitor zinc protoporphyrin IX (ZnPP-IX; 1 mg/kg lowered bilirubin and CO concentrations to control values, thus abolishing all the cardioprotective effects of hemin. In conclusion, the results demonstrate that chronic HO-1 activation by prolonged administration of hemin improves survival and exerts protective effects in a rat model of myocardial ischemia by exerting a potent antioxidant activity and disrupting multiple levels of the apoptotic and inflammatory cascade.

Beneficial effect of prolonged heme oxygenase 1 activation in a rat model of chronic heart failure.

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Collino, Massimo; Pini, Alessandro; Mugelli, Niccolò; Mastroianni, Rosanna; Bani, Daniele; Fantozzi, Roberto; Papucci, Laura; Fazi, Marilena; Masini, Emanuela

2013-07-01

We and others have previously demonstrated that heme oxygenase 1 (HO-1) induction by acute hemin administration exerts cardioprotective effects. Here, we developed a rat model of heart failure to investigate whether a long-term induction of HO-1 by chronic hemin administration exerted protective effects. Sprague Dawley rats that underwent permanent ligation of the left coronary artery were closely monitored for survival rate analysis and sacrificed on day 28 post-operation. Administration of hemin (4 mg/kg body weight) every other day for 4 weeks induced a massive increase in HO-1 expression and activity, as shown by the increased levels of the two main metabolic products of heme degradation, bilirubin and carbon monoxide (CO). These effects were associated with significant improvement in survival and reduced the extension of myocardial damage. The ischemic hearts of the hemin-treated animals displayed reduced oxidative stress and apoptosis in comparison with the non-treated rats, as shown by the decreased levels of lipid peroxidation, free-radical-induced DNA damage, caspase-3 activity and Bax expression. Besides, chronic HO-1 activation suppressed the elevated levels of myeloperoxidase (MPO) activity, interleukin 1β (IL-1β) production and tumor necrosis factor-α (TNFα) production that were evoked by the ischemic injury, and increased the plasma level of the anti-inflammatory cytokine IL-10. Interestingly, HO-1 inhibitor zinc protoporphyrin IX (ZnPP-IX; 1 mg/kg) lowered bilirubin and CO concentrations to control values, thus abolishing all the cardioprotective effects of hemin. In conclusion, the results demonstrate that chronic HO-1 activation by prolonged administration of hemin improves survival and exerts protective effects in a rat model of myocardial ischemia by exerting a potent antioxidant activity and disrupting multiple levels of the apoptotic and inflammatory cascade.

Spatiotemporal expression of heme oxygenase-1 detected by in vivo bioluminescence after hepatic ischemia in HO-1/luc mice

NARCIS (Netherlands)

Su, Huawei; van Dam, Gooitzen M.; Buis, Carlijn I.; Visser, Dorien S.; Hesselink, Jan Willem; Schuurs, Theo A.; Leuvenink, Henri G. D.; Contag, Christopher H.; Porte, Robert J.

Upregulation of heme oxygenase-1 (HO-1) has been proposed as a critical mechanism protecting against cellular stress during liver transplantation, providing a potential target for new therapeutic interventions. We investigated the feasibility of in vivo bioluminescence imaging (BLI) to noninvasively

MAPK/JNK1 activation protects cells against cadmium-induced autophagic cell death via differential regulation of catalase and heme oxygenase-1 in oral cancer cells.

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So, Keum-Young; Kim, Sang-Hun; Jung, Ki-Tae; Lee, Hyun-Young; Oh, Seon-Hee

2017-10-01

Antioxidant enzymes are related to oral diseases. We investigated the roles of heme oxygenase-1 (HO-1) and catalase in cadmium (Cd)-induced oxidative stress and the underlying molecular mechanism in oral cancer cells. Exposing YD8 cells to Cd reduced the expression levels of catalase and superoxide dismutase 1/2 and induced the expression of HO-1 as well as autophagy and apoptosis, which were reversed by N-acetyl-l-cysteine (NAC). Cd-exposed YD10B cells exhibited milder effects than YD8 cells, indicating that Cd sensitivity is associated with antioxidant enzymes and autophagy. Autophagy inhibition via pharmacologic and genetic modulations enhanced Cd-induced HO-1 expression, caspase-3 cleavage, and the production of reactive oxygen species (ROS). Ho-1 knockdown increased autophagy and apoptosis. Hemin treatment partially suppressed Cd-induced ROS production and apoptosis, but enhanced autophagy and CHOP expression, indicating that autophagy induction is associated with cellular stress. Catalase inhibition by pharmacological and genetic modulations increased Cd-induced ROS production, autophagy, and apoptosis, but suppressed HO-1, indicating that catalase is required for HO-1 induction. p38 inhibition upregulated Cd-induced phospho-JNK and catalase, but suppressed HO-1, autophagy, apoptosis. JNK suppression exhibited contrary results, enhancing the expression of phospho-p38. Co-suppression of p38 and JNK1 failed to upregulate catalase and procaspase-3, which were upregulated by JNK1 overexpression. Overall, the balance between the responses of p38 and JNK activation to Cd appears to have an important role in maintaining cellular homeostasis via the regulation of antioxidant enzymes and autophagy induction. In addition, the upregulation of catalase by JNK1 activation can play a critical role in cell protection against Cd-induced oxidative stress. Copyright © 2017 Elsevier Inc. All rights reserved.

Over-expression of heme oxygenase-1 promotes oxidative mitochondrial damage in rat astroglia.

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Song, Wei; Su, Haixiang; Song, Sisi; Paudel, Hemant K; Schipper, Hyman M

2006-03-01

Glial heme oxygenase-1 is over-expressed in the CNS of subjects with Alzheimer disease (AD), Parkinson disease (PD) and multiple sclerosis (MS). Up-regulation of HO-1 in rat astroglia has been shown to facilitate iron sequestration by the mitochondrial compartment. To determine whether HO-1 induction promotes mitochondrial oxidative stress, assays for 8-epiPGF(2alpha) (ELISA), protein carbonyls (ELISA) and 8-OHdG (HPLC-EC) were used to quantify oxidative damage to lipids, proteins, and nucleic acids, respectively, in mitochondrial fractions and whole-cell compartments derived from cultured rat astroglia engineered to over-express human (h) HO-1 by transient transfection. Cell viability was assessed by trypan blue exclusion and the MTT assay, and cell proliferation was determined by [3H] thymidine incorporation and total cell counts. In rat astrocytes, hHO-1 over-expression (x 3 days) resulted in significant oxidative damage to mitochondrial lipids, proteins, and nucleic acids, partial growth arrest, and increased cell death. These effects were attenuated by incubation with 1 microM tin mesoporphyrin, a competitive HO inhibitor, or the iron chelator, deferoxamine. Up-regulation of HO-1 engenders oxidative mitochondrial injury in cultured rat astroglia. Heme-derived ferrous iron and carbon monoxide (CO) may mediate the oxidative modification of mitochondrial lipids, proteins and nucleic acids in these cells. Glial HO-1 hyperactivity may contribute to cellular oxidative stress, pathological iron deposition, and bioenergetic failure characteristic of degenerating and inflamed neural tissues and may constitute a rational target for therapeutic intervention in these conditions. Copyright 2005 Wiley-Liss, Inc.

Post acceleration of a pseudospark-produced electron beam by an induction linac

International Nuclear Information System (INIS)

Ding, B.N.; Myers, T.J.; Rhee, M.J.

1992-01-01

Recently, a high-brightness electron beam produced by a simple pseudospark device has been reported. Typically, the electron beam has a peak current of up to 1 kA, FWHM pulse duration of 30 ns, and an effective emittance of 4[ 2 > r2 > - 2] 1/2 = 100 mm-mrad. The normalized brightness of the beam is estimated to be on the order of 10 11 A/(m 2 -rad 2 ). This high-brightness beam may be immediately useful for high current accelerators and free-electron lasers if the beam energy can be boosted up. In this paper, the authors present preliminary results of the post acceleration of the electron beam by using an induction linac. The pseudospark device is modified by adding a trigger electrode in the hollow cavity of the cathode so that the generation of the electron beam is synchronized with the induction linac. A simple induction linac system of 25 kV, 1 kA, 50 ns pulse is being constructed. The electron beam, which is born in a low pressure gas, will be accelerated in the same background gas. This gas provides a sufficient ion channel for necessary focusing of this high-current density beam. Preliminary results on the beam current, energy spectrum, and emittance measurements of the post-accelerated beam will be presented

Therapeutic Roles of Heme Oxygenase-1 in Metabolic Diseases: Curcumin and Resveratrol Analogues as Possible Inducers of Heme Oxygenase-1

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Yong Son

2013-01-01

Full Text Available Metabolic diseases, such as insulin resistance, type II diabetes, and obesity, are associated with a low-grade chronic inflammation (inflammatory stress, oxidative stress, and endoplasmic reticulum (ER stress. Because the integration of these stresses is critical to the pathogenesis of metabolic diseases, agents and cellular molecules that can modulate these stress responses are emerging as potential targets for intervention and treatment of metabolic diseases. It has been recognized that heme oxygenase-1 (HO-1 plays an important role in cellular protection. Because HO-1 can reduce inflammatory stress, oxidative stress, and ER stress, in part by exerting antioxidant, anti-inflammatory, and antiapoptotic effects, HO-1 has been suggested to play important roles in pathogenesis of metabolic diseases. In the present review, we will explore our current understanding of the protective mechanisms of HO-1 in metabolic diseases and present some emerging therapeutic options for HO-1 expression in treating metabolic diseases, together with the therapeutic potential of curcumin and resveratrol analogues that have their ability to induce HO-1 expression.

Identification of danthron as an isoform-specific inhibitor of HEME OXYGENASE-1/cytochrome P450 reductase interaction with anti-tumor activity.

Science.gov (United States)

Chou, Yi-Tai; Hsu, Fu-Fei; Hu, Dun-Yao; Chen, Ying-Chih; Hsu, Yuan-Hao; Hsu, John T-A; Chau, Lee-Young

2018-01-23

Heme oxygenase (HO) catalyzes NADPH-dependent degradation of heme to liberate iron, carbon monoxide and biliverdin. The interaction between HO and cytochrome P450 reductase (CPR), an electron donor, is essential for HO activity. HO-1 is a stress-inducible isoform whereas HO-2 is constitutively expressed. HO-1 induction is commonly seen in cancers and impacts disease progression, supporting the possibility of targeting HO-1 for cancer therapy. We employed a cell-based bioluminescence resonance energy transfer assay to screen compounds with ability to inhibit HO-1/CPR interaction. The effect of the identified compound on HO-1/CPR interaction was confirmed by pull down assay. Moreover, the anti-tumorigenic activity of the identified compound on HO-1-enhanced tumor growth and migration was assessed by trypan blue exclusion method and wound healing assay. Danthron was identified as an effective small molecule able to interfere with the interaction between HO-1 and CPR but not HO-2 and CPR. Additional experiments with structural analogues of danthron revealed that the positions of hydroxyl moieties significantly affected the potency of inhibition on HO-1/CPR interaction. Pull-down assay confirmed that danthron inhibited the interaction of CPR with HO-1 but not HO-2. Danthron suppressed growth and migration of HeLa cells with stable HO-1 overexpression but not mock cells. In contrast, anthrarufin, a structural analog with no ability to interfere HO-1/CPR interaction, exhibited no significant effect on HO-1-overexpressing HeLa cells. These findings demonstrate that danthron is an isoform-specific inhibitor for HO-1/CPR interaction and may serve as a lead compound for novel anticancer drug.

Controlling hollow relativistic electron beam orbits with an inductive current divider

Energy Technology Data Exchange (ETDEWEB)

Swanekamp, S. B.; Richardson, A. S.; Angus, J. R.; Cooperstein, G.; Hinshelwood, D. D.; Ottinger, P. F.; Rittersdorf, I. M.; Schumer, J. W.; Weber, B. V.; Zier, J. C. [Plasma Physics Division, Naval Research Laboratory, Washington, DC 20375 (United States)

2015-02-15

A passive method for controlling the trajectory of an intense, hollow electron beam is proposed using a vacuum structure that inductively splits the beam's return current. A central post carries a portion of the return current (I{sub 1}), while the outer conductor carries the remainder (I{sub 2}). An envelope equation appropriate for a hollow electron beam is derived and applied to the current divider. The force on the beam trajectory is shown to be proportional to (I{sub 2}-I{sub 1}), while the average force on the envelope (the beam width) is proportional to the beam current I{sub b} = (I{sub 2} + I{sub 1}). The values of I{sub 1} and I{sub 2} depend on the inductances in the return-current path geometries. Proper choice of the return-current geometries determines these inductances and offers control over the beam trajectory. Solutions using realistic beam parameters show that, for appropriate choices of the return-current-path geometry, the inductive current divider can produce a beam that is both pinched and straightened so that it approaches a target at near-normal incidence with a beam diameter that is on the order of a few mm.

Heme oxygenase-1 expression protects melanocytes from stress-induced cell death: implications for vitiligo

NARCIS (Netherlands)

Elassiuty, Yasser E.; Klarquist, Jared; Speiser, Jodi; Yousef, Randa M.; El Refaee, Abdelaziz A.; Hunter, Nahla S.; Shaker, Olfat G.; Gundeti, Mohan; Nieuweboer-Krobotova, Ludmila; Caroline Le Poole, I.

2011-01-01

To study protection of melanocytes from stress-induced cell death by heme oxygenases during depigmentation and repigmentation in vitiligo, expression of isoforms 1 and 2 was studied in cultured control and patient melanocytes and normal skin explants exposed to UV or bleaching agent 4-TBP.

OxDBase: a database of oxygenases involved in biodegradation

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Raghava Gajendra PS

2009-04-01

Full Text Available Abstract Background Oxygenases belong to the oxidoreductive group of enzymes (E.C. Class 1, which oxidize the substrates by transferring oxygen from molecular oxygen (O2 and utilize FAD/NADH/NADPH as the co-substrate. Oxygenases can further be grouped into two categories i.e. monooxygenases and dioxygenases on the basis of number of oxygen atoms used for oxidation. They play a key role in the metabolism of organic compounds by increasing their reactivity or water solubility or bringing about cleavage of the aromatic ring. Findings We compiled a database of biodegradative oxygenases (OxDBase which provides a compilation of the oxygenase data as sourced from primary literature in the form of web accessible database. There are two separate search engines for searching into the database i.e. mono and dioxygenases database respectively. Each enzyme entry contains its common name and synonym, reaction in which enzyme is involved, family and subfamily, structure and gene link and literature citation. The entries are also linked to several external database including BRENDA, KEGG, ENZYME and UM-BBD providing wide background information. At present the database contains information of over 235 oxygenases including both dioxygenases and monooxygenases. This database is freely available online at http://www.imtech.res.in/raghava/oxdbase/. Conclusion OxDBase is the first database that is dedicated only to oxygenases and provides comprehensive information about them. Due to the importance of the oxygenases in chemical synthesis of drug intermediates and oxidation of xenobiotic compounds, OxDBase database would be very useful tool in the field of synthetic chemistry as well as bioremediation.

The role of heme oxygenase-1 in drug metabolizing dysfunction in the alcoholic fatty liver exposed to ischemic injury

Energy Technology Data Exchange (ETDEWEB)

Park, Sang Won [Department of Pharmacology, Institute of Health Sciences, Gyeongsang National University School of Medicine, Jinju 52727 (Korea, Republic of); Kang, Jung-Woo [School of Pharmacy, Sungkyunkwan University, Suwon, Gyeonggi-do 16419 (Korea, Republic of); Lee, Sun-Mee, E-mail: sunmee@skku.edu [School of Pharmacy, Sungkyunkwan University, Suwon, Gyeonggi-do 16419 (Korea, Republic of)

2016-02-01

This study was designed to investigate the role of heme oxygenase-1 (HO-1) in hepatic drug metabolizing dysfunction after ischemia/reperfusion (IR) in alcoholic fatty liver (AFL). Rats were fed a Lieber–DeCarli diet for five weeks to allow for development of AFL and were then subjected to 90 min of hepatic ischemia and 5 h of reperfusion. Rats were pretreated with hemin (HO-1 inducer) or ZnPP (HO-1 inhibitor) for 16 h and 3 h before hepatic ischemia. After hepatic IR, ethanol diet (ED)-fed rats had higher serum aminotransferase activities and more severe hepatic necrosis compared to the control diet (CD)-fed rats. These changes were attenuated by hemin and exacerbated by ZnPP. The activity and gene expression of HO-1 and its transcription factor (Nrf2) level increased significantly after 5 h of reperfusion in CD-fed rats but not in ED-fed rats. After reperfusion, cytochrome P450 (CYP) 1A1, 1A2, and 2B1 activities were reduced to levels lower than those observed in sham group, whereas CYP2E1 activity increased. The decrease in CYP2B1 activity and the increase in CYP2E1 activity were augmented after hepatic IR in ED-fed animals. These changes were significantly attenuated by hemin but aggravated by ZnPP. Finally, CHOP expression and PERK phosphorylation, microsomal lipid peroxidation, and levels of proinflammatory mediators increased in ED-fed rats compared to CD-fed rats after reperfusion. These increases were attenuated by hemin. Our results suggest that AFL exacerbates hepatic drug metabolizing dysfunction during hepatic IR via endoplasmic reticulum stress and lipid peroxidation and this is associated with impaired HO-1 induction. - Highlights: • Endogenous HO-1 is generated in insufficient quantities in steatotic ischemic injury. • Impaired HO-1 induction leads to excessive ER stress response and lipid peroxidation. • Alcoholic steatosis exacerbates IR-induced hepatic drug-metabolizing dysfunction. • HO-1 induction is required for appropriate medication

Impact of heme oxygenase-1 on cholesterol synthesis, cholesterol efflux and oxysterol formation in cultured astroglia.

Science.gov (United States)

Hascalovici, Jacob R; Song, Wei; Vaya, Jacob; Khatib, Soliman; Fuhrman, Bianca; Aviram, Michael; Schipper, Hyman M

2009-01-01

Up-regulation of heme oxygenase-1 (HO-1) and altered cholesterol (CH) metabolism are characteristic of Alzheimer-diseased neural tissues. The liver X receptor (LXR) is a molecular sensor of CH homeostasis. In the current study, we determined the effects of HO-1 over-expression and its byproducts iron (Fe(2+)), carbon monoxide (CO) and bilirubin on CH biosynthesis, CH efflux and oxysterol formation in cultured astroglia. HO-1/LXR interactions were also investigated in the context of CH efflux. hHO-1 over-expression for 3 days ( approximately 2-3-fold increase) resulted in a 30% increase in CH biosynthesis and a two-fold rise in CH efflux. Both effects were abrogated by the competitive HO inhibitor, tin mesoporphyrin. CO, released from administered CORM-3, significantly enhanced CH biosynthesis; a combination of CO and iron stimulated CH efflux. Free iron increased oxysterol formation three-fold. Co-treatment with LXR antagonists implicated LXR activation in the modulation of CH homeostasis by heme degradation products. In Alzheimer's disease and other neuropathological states, glial HO-1 induction may transduce ambient noxious stimuli (e.g. beta-amyloid) into altered patterns of glial CH homeostasis. As the latter may impact synaptic plasticity and neuronal repair, modulation of glial HO-1 expression (by pharmacological or other means) may confer neuroprotection in patients with degenerative brain disorders.

Upregulation of endothelial heme oxygenase-1 expression through the activation of the JNK pathway by sublethal concentrations of acrolein

International Nuclear Information System (INIS)

Wu, C.C.; Hsieh, C.W.; Lai, P.H.; Lin, J.B.; Liu, Y.C.; Wung, B.S.

2006-01-01

Acrolein is a highly electrophilic α,β-unsaturated aldehyde that is present in cigarette smoke. Heme oxygenase-1 (HO-1) is a cytoprotective enzyme activated by various such electrophilic compounds. In this study, the regulatory effects of acrolein upon the expression of HO-1 were investigated in endothelial cells (ECs). We demonstrate that acrolein induces the elevation of HO-1 protein levels, and subsequent enzyme activity, at non-cytotoxic concentrations. An additional α,β-unsaturated aldehyde, cinnamaldehyde, was also found to increase HO-1 expression and have less cytotoxicity than acrolein. Moreover, acrolein-mediated HO-1 induction is abrogated in the presence of actinomycin D and cycloheximide. Nrf2 is a transcription factor involved in the induction of HO-1 through an antioxidant response element (ARE) in the promoter region of the HO-1 gene. We show that acrolein induces Nrf2 translocation and ARE-luciferase reporter activity. Acrolein was also found to induce the production of both superoxide and H 2 O 2 at levels greater than 100 μM. However, with the exception of NAC, no antioxidant generated any effect upon acrolein-dependent HO-1 expression in ECs. Our present findings suggest that reactive oxygen species (ROS) may not be a major modulator for HO-1 induction. Using buthionine sulfoximine to deplete the intracellular GSH levels further enhanced the effects of acrolein. We also found that cellular GSH level was rapidly reduced after both 10 and 100 μM acrolein treatment. However, after 6 h of exposure to ECs, only 10 μM acrolein treatment increases GSH level. In addition, only the JNK inhibitor SP600125 and tyrosine kinase inhibitor genistein had any significant inhibitory impact upon the upregulation of HO-1 by acrolein. Pretreatment with a range of other PI3 kinase inhibitors, including wortmannin and LY294002, showed no effects. Hence, we show in our current experiments that a sublethal concentration of acrolein is in fact a novel HO-1 inducer

Upregulation of endothelial heme oxygenase-1 expression through the activation of the JNK pathway by sublethal concentrations of acrolein.

Science.gov (United States)

Wu, C C; Hsieh, C W; Lai, P H; Lin, J B; Liu, Y C; Wung, B S

2006-08-01

Acrolein is a highly electrophilic alpha,beta-unsaturated aldehyde that is present in cigarette smoke. Heme oxygenase-1 (HO-1) is a cytoprotective enzyme activated by various such electrophilic compounds. In this study, the regulatory effects of acrolein upon the expression of HO-1 were investigated in endothelial cells (ECs). We demonstrate that acrolein induces the elevation of HO-1 protein levels, and subsequent enzyme activity, at non-cytotoxic concentrations. An additional alpha,beta-unsaturated aldehyde, cinnamaldehyde, was also found to increase HO-1 expression and have less cytotoxicity than acrolein. Moreover, acrolein-mediated HO-1 induction is abrogated in the presence of actinomycin D and cycloheximide. Nrf2 is a transcription factor involved in the induction of HO-1 through an antioxidant response element (ARE) in the promoter region of the HO-1 gene. We show that acrolein induces Nrf2 translocation and ARE-luciferase reporter activity. Acrolein was also found to induce the production of both superoxide and H2O2 at levels greater than 100 microM. However, with the exception of NAC, no antioxidant generated any effect upon acrolein-dependent HO-1 expression in ECs. Our present findings suggest that reactive oxygen species (ROS) may not be a major modulator for HO-1 induction. Using buthionine sulfoximine to deplete the intracellular GSH levels further enhanced the effects of acrolein. We also found that cellular GSH level was rapidly reduced after both 10 and 100 microM acrolein treatment. However, after 6 h of exposure to ECs, only 10 microM acrolein treatment increases GSH level. In addition, only the JNK inhibitor SP600125 and tyrosine kinase inhibitor genistein had any significant inhibitory impact upon the upregulation of HO-1 by acrolein. Pretreatment with a range of other PI3 kinase inhibitors, including wortmannin and LY294002, showed no effects. Hence, we show in our current experiments that a sublethal concentration of acrolein is in fact a

Omeprazole induces heme oxygenase-1 in fetal human pulmonary microvascular endothelial cells via hydrogen peroxide-independent Nrf2 signaling pathway

Energy Technology Data Exchange (ETDEWEB)

Patel, Ananddeep; Zhang, Shaojie; Shrestha, Amrit Kumar; Maturu, Paramahamsa; Moorthy, Bhagavatula; Shivanna, Binoy, E-mail: shivanna@bcm.edu

2016-11-15

Omeprazole (OM) is an aryl hydrocarbon receptor (AhR) agonist and a proton pump inhibitor that is used to treat humans with gastric acid related disorders. Recently, we showed that OM induces NAD (P) H quinone oxidoreductase-1 (NQO1) via nuclear factor erythroid 2-related factor 2 (Nrf2)-dependent mechanism. Heme oxygenase-1 (HO-1) is another cytoprotective and antioxidant enzyme that is regulated by Nrf2. Whether OM induces HO-1 in fetal human pulmonary microvascular endothelial cells (HPMEC) is unknown. Therefore, we tested the hypothesis that OM will induce HO-1 expression via Nrf2 in HPMEC. OM induced HO-1 mRNA and protein expression in a dose-dependent manner. siRNA-mediated knockdown of AhR failed to abrogate, whereas knockdown of Nrf2 abrogated HO-1 induction by OM. To identify the underlying molecular mechanisms, we determined the effects of OM on cellular hydrogen peroxide (H{sub 2}O{sub 2}) levels since oxidative stress mediated by the latter is known to activate Nrf2. Interestingly, the concentration at which OM induced HO-1 also increased H{sub 2}O{sub 2} levels. Furthermore, H{sub 2}O{sub 2} independently augmented HO-1 expression. Although N-acetyl cysteine (NAC) significantly decreased H{sub 2}O{sub 2} levels in OM-treated cells, we observed that OM further increased HO-1 mRNA and protein expression in NAC-pretreated compared to vehicle-pretreated cells, suggesting that OM induces HO-1 via H{sub 2}O{sub 2}-independent mechanisms. In conclusion, we provide evidence that OM transcriptionally induces HO-1 via AhR - and H{sub 2}O{sub 2} - independent, but Nrf2 - dependent mechanisms. These results have important implications for human disorders where Nrf2 and HO-1 play a beneficial role. - Highlights: • Omeprazole induces HO-1 in human fetal lung cells. • AhR deficiency fails to abrogate omeprazole-mediated induction of HO-1. • Nrf2 knockdown abrogates omeprazole-mediated HO-1 induction in human lung cells. • Hydrogen peroxide depletion augments

Heme oxygenase-1 prevents non-alcoholic steatohepatitis through suppressing hepatocyte apoptosis in mice

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Fu Na

2010-10-01

Full Text Available Abstract Objective Heme oxygenase-1 (HO-1, the rate-limiting enzyme in heme catabolism, has been reported to have potential antioxidant properties. However, the role of HO-1 on hepatocyte apoptosis remains unclear. We aim to elucidate the effects of HO-1 on oxidative stress related hepatocellular apoptosis in nutritional steatohepatitis in mice. Methods C57BL/6J mice were fed with methionine-choline deficient (MCD diet for four weeks to induce hepatic steatohepatitis. HO-1 chemical inducer (hemin, HO-1 chemical inhibitor zinc protoporphyrin IX (ZnPP-IX and/or adenovirus carrying HO-1 gene (Ad-HO-1 were administered to mice, respectively. Hepatocyte apoptosis was evaluated by terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL assay, the mRNA and protein expression of apoptosis related genes were assayed by quantitative real-time PCR and Western blot. Results Hepatocyte signs of oxidative related apoptotic injury were presented in mice fed with MCD diet for 4 weeks. Induction of HO-1 by hemin or Ad-HO-1 significantly attenuated the severity of liver histology, which was associated with decreased hepatic lipid peroxidation content, reduced number of apoptotic cells by TUNEL staining, down-regulated expression of pro-apoptosis related genes including Fas/FasL, Bax, caspase-3 and caspase-9, reduced expression of cytochrome p4502E1 (CYP2E1, inhibited cytochrome c (Cyt-c release, and up-regulated expression of anti-apoptosis gene Bcl-2. Whereas, inhibition of HO-1 by ZnPP-IX caused oxidative stress related hepatic injury, which concomitant with increased number of TUNEL positive cells and up-regulated expression of pro-apoptosis related genes. Conclusions The present study provided evidences for the protective role of HO-1 in preventing nutritional steatohepatitis through suppressing hepatocyte apoptosis in mice.

Involvement of Heme Oxygenase-1 Induction in the Cytoprotective and Immunomodulatory Activities of Viola patrinii in Murine Hippocampal and Microglia Cells

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Bin Li

2012-01-01

Full Text Available A number of diseases that lead to injury of the central nervous system are caused by oxidative stress and inflammation in the brain. In this study, NNMBS275, consisting of the ethanol extract of Viola patrinii, showed potent antioxidative and anti-inflammatory activity in murine hippocampal HT22 cells and BV2 microglia. NNMBS275 increased cellular resistance to oxidative injury caused by glutamate-induced neurotoxicity and reactive oxygen species generation in HT22 cells. In addition, the anti-inflammatory effects of NNMBS275 were demonstrated by the suppression of proinflammatory mediators, including proinflammatory enzymes (inducible nitric oxide synthase and cyclooxygenase-2 and cytokines (tumor necrosis factor-α and interleukin-1β. Furthermore, we found that the neuroprotective and anti-inflammatory effects of NNMBS275 were linked to the upregulation of nuclear transcription factor-E2-related factor 2-dependent expression of heme oxygenase-1 in HT22 and BV2 cells. These results suggest that NNMBS275 possesses therapeutic potential against neurodegenerative diseases that are induced by oxidative stress and neuroinflammation.

A novel, "double-clamp" binding mode for human heme oxygenase-1 inhibition.

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Mona N Rahman

Full Text Available The development of heme oxygenase (HO inhibitors is critical in dissecting and understanding the HO system and for potential therapeutic applications. We have established a program to design and optimize HO inhibitors using structure-activity relationships in conjunction with X-ray crystallographic analyses. One of our previous complex crystal structures revealed a putative secondary hydrophobic binding pocket which could be exploited for a new design strategy by introducing a functional group that would fit into this potential site. To test this hypothesis and gain further insights into the structural basis of inhibitor binding, we have synthesized and characterized 1-(1H-imidazol-1-yl-4,4-diphenyl-2-butanone (QC-308. Using a carbon monoxide (CO formation assay on rat spleen microsomes, the compound was found to be ∼15 times more potent (IC(50 = 0.27±0.07 µM than its monophenyl analogue, which is already a potent compound in its own right (QC-65; IC(50 = 4.0±1.8 µM. The crystal structure of hHO-1 with QC-308 revealed that the second phenyl group in the western region of the compound is indeed accommodated by a definitive secondary proximal hydrophobic pocket. Thus, the two phenyl moieties are each stabilized by distinct hydrophobic pockets. This "double-clamp" binding offers additional inhibitor stabilization and provides a new route for improvement of human heme oxygenase inhibitors.

A novel, "double-clamp" binding mode for human heme oxygenase-1 inhibition.

Science.gov (United States)

Rahman, Mona N; Vlahakis, Jason Z; Vukomanovic, Dragic; Lee, Wallace; Szarek, Walter A; Nakatsu, Kanji; Jia, Zongchao

2012-01-01

The development of heme oxygenase (HO) inhibitors is critical in dissecting and understanding the HO system and for potential therapeutic applications. We have established a program to design and optimize HO inhibitors using structure-activity relationships in conjunction with X-ray crystallographic analyses. One of our previous complex crystal structures revealed a putative secondary hydrophobic binding pocket which could be exploited for a new design strategy by introducing a functional group that would fit into this potential site. To test this hypothesis and gain further insights into the structural basis of inhibitor binding, we have synthesized and characterized 1-(1H-imidazol-1-yl)-4,4-diphenyl-2-butanone (QC-308). Using a carbon monoxide (CO) formation assay on rat spleen microsomes, the compound was found to be ∼15 times more potent (IC(50) = 0.27±0.07 µM) than its monophenyl analogue, which is already a potent compound in its own right (QC-65; IC(50) = 4.0±1.8 µM). The crystal structure of hHO-1 with QC-308 revealed that the second phenyl group in the western region of the compound is indeed accommodated by a definitive secondary proximal hydrophobic pocket. Thus, the two phenyl moieties are each stabilized by distinct hydrophobic pockets. This "double-clamp" binding offers additional inhibitor stabilization and provides a new route for improvement of human heme oxygenase inhibitors.

Covalent heme attachment to the protein in human heme oxygenase-1 with selenocysteine replacing the His25 proximal iron ligand.

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Jiang, Yongying; Trnka, Michael J; Medzihradszky, Katalin F; Ouellet, Hugues; Wang, Yongqiang; Ortiz de Montellano, Paul R

2009-03-01

To characterize heme oxygenase with a selenocysteine (SeCys) as the proximal iron ligand, we have expressed truncated human heme oxygenase-1 (hHO-1) His25Cys, in which Cys-25 is the only cysteine, in the Escherichia coli cysteine auxotroph strain BL21(DE3)cys. Selenocysteine incorporation into the protein was demonstrated by both intact protein mass measurement and mass spectrometric identification of the selenocysteine-containing tryptic peptide. One selenocysteine was incorporated into approximately 95% of the expressed protein. Formation of an adduct with Ellman's reagent (DTNB) indicated that the selenocysteine in the expressed protein was in the reduced state. The heme-His25SeCys hHO-1 complex could be prepared by either (a) supplementing the overexpression medium with heme, or (b) reconstituting the purified apoprotein with heme. Under reducing conditions in the presence of imidazole, a covalent bond is formed by addition of the selenocysteine residue to one of the heme vinyl groups. No covalent bond is formed when the heme is replaced by mesoheme, in which the vinyls are replaced by ethyl groups. These results, together with our earlier demonstration that external selenolate ligands can transfer an electron to the iron [Y. Jiang, P.R. Ortiz de Montellano, Inorg. Chem. 47 (2008) 3480-3482 ], indicate that a selenyl radical is formed in the hHO-1 His25SeCys mutant that adds to a heme vinyl group.

Observation of Magnetic Induction Distribution by Scanning Interference Electron Microscopy

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Takahashi, Yoshio; Yajima, Yusuke; Ichikawa, Masakazu; Kuroda, Katsuhiro

1994-09-01

A scanning interference electron microscope (SIEM) capable of observing magnetic induction distribution with high sensitivity and spatial resolution has been developed. The SIEM uses a pair of fine coherent scanning probes and detects their relative phase change by magnetic induction, giving raster images of microscopic magnetic distributions. Its performance has been demonstrated by observing magnetic induction distributed near the edge of a recorded magnetic storage medium. Obtained images are compared with corresponding images taken in the scanning Lorentz electron microscope mode using the same microscope, and the differences between them are discussed.

Heme oxygenase-1 (HO-1 expression in prostate cancer cells modulates the oxidative response in bone cells.

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Mercedes Ferrando

Full Text Available Prostate cancer (PCa is a leading cause of death among males. It is currently estimated that inflammatory responses are linked to 15-20% of all deaths from cancer worldwide. PCa is dominated by complications arising from metastasis to the bone where the tumor cells interact with the bone microenvironment impairing the balance between bone formation and degradation. However, the molecular nature of this interaction is not completely understood. Heme oxygenase-1 (HO-1 counteracts oxidative damage and inflammation. Previous studies from our laboratory showed that HO-1 is implicated in PCa, demonstrating that endogenous HO-1 inhibits bone derived-prostate cancer cells proliferation, invasion and migration and decreases tumor growth and angiogenesis in vivo. The aim of this work was to analyze the impact of HO-1 modulated PCa cells on osteoblasts proliferation in vitro and on bone remodeling in vivo. Using a co-culture system of PC3 cells with primary mice osteoblasts (PMOs, we demonstrated that HO-1 pharmacological induction (hemin treatment abrogated the diminution of PMOs proliferation induced by PCa cells and decreased the expression of osteoclast-modulating factors in osteoblasts. No changes were detected in the expression of genes involved in osteoblasts differentiation. However, co-culture of hemin pre-treated PC3 cells (PC3 Hem with PMOs provoked an oxidative status and activated FoxO signaling in osteoblasts. The percentage of active osteoblasts positive for HO-1 increased in calvarias explants co-cultured with PC3 Hem cells. Nuclear HO-1 expression was detected in tumors generated by in vivo bone injection of HO-1 stable transfected PC3 (PC3HO-1 cells in the femur of SCID mice. These results suggest that HO-1 has the potential to modify the bone microenvironment impacting on PCa bone metastasis.

A low-power ASK demodulator for inductively coupled implantable electronics

DEFF Research Database (Denmark)

Gudnason, Gunnar

2000-01-01

An amplitude shift keying (ASK) demodulator is presented which is suitable for implantable electronic devices that are powered through an inductive link. The demodulator has been tested with carrier frequencies in the range 1-15 MHz, covering most commonly used frequencies. Data rates up to several...

Degradative pathways for p-toluenecarboxylate and p-toluenesulfonate and their multicomponent oxygenases in Comamonas testosteroni strains PSB-4 and T-2.

Science.gov (United States)

Junker, F; Saller, E; Schläfli Oppenberg, H R; Kroneck, P M; Leisinger, T; Cook, A M

1996-09-01

Three multicomponent oxygenases involved in the degradation of p-toluenesulfonate and p-toluenecarboxylate and the regulation of their synthesis have been examined in three strains (T-2, PSB-4 and TER-1) of Comamonas testosteroni. Strain T-2 utilizes p-toluenesulfonate as a source of carbon and energy for growth via p-sulfobenzoate and protocatechuate, and p-toluenecarboxylate via terephthalate and protocatechuate, and has the unusual property of requiring the reductase (TsaB) of the toluenesulfonate methyl monooxygenase system (TsaMB) in an incompletely expressed sulfobenzoate dioxygenase system (PsbAC) [Schläfli Oppenberg, H.R., Chen, G., Leisinger, T. & Cook, A. M. (1995). Microbiology 141, 1891-1899]. The independently isolated C. testosteroni PSB-4 utilized only sulfobenzoate and terephthalate via protocatechuate. Mutant TER-1, derived from strain T-2, utilized only terephthalate via protocatechuate. We detected no enzymes of the pathway from toluenesulfonate to sulfobenzoate in strains PSB-4 and TER-1, and confirmed by PCR and Southern blot analysis that the genes (tsaMB) encoding toluenesulfonate monooxygenase were absent. We concluded that, in strain PSB-4, the regulatory unit encoding the genes for the conversion of toluenesulfonate to sulfobenzoate was missing, and that generation of mutant TER-1 involved deletion of this regulatory unit and of the regulatory unit encoding desulfonation of sulfobenzoate. The degradation of sulfobenzoate in strain PSB-4 was catalysed by a fully inducible sulfobenzoate dioxygenase system (PsbACPSB-4), which, after purification of the oxygenase component (PsbAPSB-4), turned out to be indistinguishable from the corresponding component from strain T-2 (PsbAT-2). Reductase PsbCPSB-4, which we could separate but not purify, was active with oxygenase PsbAPSB-4 and PsbAT-2. Oxygenase PsbAPSB-4 was shown by electron paramagnetic resonance spectroscopy to contain a Rieske [2Fe-2S] centre. The enzyme system oxygenating terephthalate

A Novel, “Double-Clamp” Binding Mode for Human Heme Oxygenase-1 Inhibition

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Rahman, Mona N.; Vlahakis, Jason Z.; Vukomanovic, Dragic; Lee, Wallace; Szarek, Walter A.; Nakatsu, Kanji; Jia, Zongchao

2012-01-01

The development of heme oxygenase (HO) inhibitors is critical in dissecting and understanding the HO system and for potential therapeutic applications. We have established a program to design and optimize HO inhibitors using structure-activity relationships in conjunction with X-ray crystallographic analyses. One of our previous complex crystal structures revealed a putative secondary hydrophobic binding pocket which could be exploited for a new design strategy by introducing a functional group that would fit into this potential site. To test this hypothesis and gain further insights into the structural basis of inhibitor binding, we have synthesized and characterized 1-(1H-imidazol-1-yl)-4,4-diphenyl-2-butanone (QC-308). Using a carbon monoxide (CO) formation assay on rat spleen microsomes, the compound was found to be ∼15 times more potent (IC50 = 0.27±0.07 µM) than its monophenyl analogue, which is already a potent compound in its own right (QC-65; IC50 = 4.0±1.8 µM). The crystal structure of hHO-1 with QC-308 revealed that the second phenyl group in the western region of the compound is indeed accommodated by a definitive secondary proximal hydrophobic pocket. Thus, the two phenyl moieties are each stabilized by distinct hydrophobic pockets. This “double-clamp” binding offers additional inhibitor stabilization and provides a new route for improvement of human heme oxygenase inhibitors. PMID:22276118

Ascorbic acid deficiency decreases hepatic cytochrome P-450, especially CYP2B1/2B2, and simultaneously induces heme oxygenase-1 gene expression in scurvy-prone ODS rats.

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Kobayashi, Misato; Hoshinaga, Yukiko; Miura, Natsuko; Tokuda, Yuki; Shigeoka, Shigeru; Murai, Atsushi; Horio, Fumihiko

2014-01-01

The mechanisms underlying the decrease in hepatic cytochrome P-450 (CYP) content in ascorbic acid deficiency was investigated in scurvy-prone ODS rats. First, male ODS rats were fed a diet containing sufficient ascorbic acid (control) or a diet without ascorbic acid (deficient) for 18 days, with or without the intraperitoneal injection of phenobarbital. Ascorbic acid deficiency decreased hepatic microsomal total CYP content, CYP2B1/2B2 protein, and mitochondrial cytochrome oxidase (COX) complex IV subunit I protein, and simultaneously increased heme oxygenase-1 protein in microsomes and mitochondria. Next, heme oxygenase-1 inducers, that is lipopolysaccharide and hemin, were administered to phenobaribital-treated ODS rats fed sufficient ascorbic acid. The administration of these inducers decreased hepatic microsomal total CYP content, CYP2B1/2B2 protein, and mitochondrial COX complex IV subunit I protein. These results suggested that the stimulation of hepatic heme oxygenase-1 expression by ascorbic acid deficiency caused the decrease in CYP content in liver.

Structure prediction and activity analysis of human heme oxygenase-1 and its mutant.

Science.gov (United States)

Xia, Zhen-Wei; Zhou, Wen-Pu; Cui, Wen-Jun; Zhang, Xue-Hong; Shen, Qing-Xiang; Li, Yun-Zhu; Yu, Shan-Chang

2004-08-15

To predict wild human heme oxygenase-1 (whHO-1) and hHO-1 His25Ala mutant (delta hHO-1) structures, to clone and express them and analyze their activities. Swiss-PdbViewer and Antheprot 5.0 were used for the prediction of structure diversity and physical-chemical changes between wild and mutant hHO-1. hHO-1 His25Ala mutant cDNA was constructed by site-directed mutagenesis in two plasmids of E. coli DH5alpha. Expression products were purified by ammonium sulphate precipitation and Q-Sepharose Fast Flow column chromatography, and their activities were measured. rHO-1 had the structure of a helical fold with the heme sandwiched between heme-heme oxygenase-1 helices. Bond angle, dihedral angle and chemical bond in the active pocket changed after Ala25 was replaced by His25, but Ala25 was still contacting the surface and the electrostatic potential of the active pocket was negative. The mutated enzyme kept binding activity to heme. Two vectors pBHO-1 and pBHO-1(M) were constructed and expressed. Ammonium sulphate precipitation and column chromatography yielded 3.6-fold and 30-fold higher purities of whHO-1, respectively. The activity of delta hHO-1 was reduced 91.21% after mutation compared with whHO-1. Proximal His25 ligand is crucial for normal hHO-1 catalytic activity. delta hHO-1 is deactivated by mutation but keeps the same binding site as whHO-1. delta hHO-1 might be a potential inhibitor of whHO-1 for preventing neonatal hyperbilirubinemia.

RoxB Is a Novel Type of Rubber Oxygenase That Combines Properties of Rubber Oxygenase RoxA and Latex Clearing Protein (Lcp).

Science.gov (United States)

Birke, Jakob; Röther, Wolf; Jendrossek, Dieter

2017-07-15

Only two types of rubber oxygenases, rubber oxygenase (RoxA) and latex clearing protein (Lcp), have been described so far. RoxA proteins (RoxAs) are c -type cytochromes of ≈70 kDa produced by Gram-negative rubber-degrading bacteria, and they cleave polyisoprene into 12-oxo-4,8-dimethyltrideca-4,8-diene-1-al (ODTD), a C 15 oligo-isoprenoid, as the major end product. Lcps are common among Gram-positive rubber degraders and do not share amino acid sequence similarities with RoxAs. Furthermore, Lcps have much smaller molecular masses (≈40 kDa), are b -type cytochromes, and cleave polyisoprene to a mixture of C 20 , C 25 , C 30 , and higher oligo-isoprenoids as end products. In this article, we purified a new type of rubber oxygenase, RoxB Xsp (RoxB of Xanthomonas sp. strain 35Y). RoxB Xsp is distantly related to RoxAs and resembles RoxAs with respect to molecular mass (70.3 kDa for mature protein) and cofactor content (2 c -type hemes). However, RoxB Xsp differs from all currently known RoxAs in having a distinctive product spectrum of C 20 , C 25 , C 30 , and higher oligo-isoprenoids that has been observed only for Lcps so far. Purified RoxB Xsp revealed the highest specific activity of 4.5 U/mg (at 23°C) of all currently known rubber oxygenases and exerts a synergistic effect on the efficiency of polyisoprene cleavage by RoxA Xsp RoxB homologs were identified in several other Gram-negative rubber-degrading species, pointing to a prominent function of RoxB for the biodegradation of rubber in Gram-negative bacteria. IMPORTANCE The enzymatic cleavage of rubber (polyisoprene) is of high environmental importance given that enormous amounts of rubber waste materials are permanently released (e.g., by abrasion of tires). Research from the last decade has discovered rubber oxygenase A, RoxA, and latex clearing protein (Lcp) as being responsible for the primary enzymatic attack on the hydrophobic and water-insoluble biopolymer poly( cis -1,4-isoprene) in Gram

Heme oxygenase and carbon monoxide protect from muscle dystrophy.

Science.gov (United States)

Chan, Mun Chun; Ziegler, Olivia; Liu, Laura; Rowe, Glenn C; Das, Saumya; Otterbein, Leo E; Arany, Zoltan

2016-11-28

Duchenne muscle dystrophy (DMD) is one of the most common lethal genetic diseases of children worldwide and is 100% fatal. Steroids, the only therapy currently available, are marred by poor efficacy and a high side-effect profile. New therapeutic approaches are urgently needed. Here, we leverage PGC-1α, a powerful transcriptional coactivator known to protect against dystrophy in the mdx murine model of DMD, to search for novel mechanisms of protection against dystrophy. We identify heme oxygenase-1 (HO-1) as a potential novel target for the treatment of DMD. Expression of HO-1 is blunted in the muscles from the mdx murine model of DMD, and further reduction of HO-1 by genetic haploinsufficiency worsens muscle damage in mdx mice. Conversely, induction of HO-1 pharmacologically protects against muscle damage. Mechanistically, HO-1 degrades heme into biliverdin, releasing in the process ferrous iron and carbon monoxide (CO). We show that exposure to a safe low dose of CO protects against muscle damage in mdx mice, as does pharmacological treatment with CO-releasing molecules. These data identify HO-1 and CO as novel therapeutic agents for the treatment of DMD. Safety profiles and clinical testing of inhaled CO already exist, underscoring the translational potential of these observations.

Reduced caveolin-1 promotes hyper-inflammation due to abnormal heme oxygenase-1 localizationin LPS challenged macrophages with dysfunctional CFTR

Science.gov (United States)

Zhang, Ping-Xia; Murray, Thomas S.; Villella, Valeria Rachela; Ferrari, Eleonora; Esposito, Speranza; D'Souza, Anthony; Raia, Valeria; Maiuri, Luigi; Krause, Diane S.; Egan, Marie E.; Bruscia, Emanuela M.

2013-01-01

We have previously reported that TLR4 signaling is increased in lipopolysaccharide (LPS) -stimulated Cystic Fibrosis (CF) macrophages (MΦs), contributing to the robust production of pro-inflammatory cytokines. The heme oxygenase (HO-1)/carbon monoxide (CO) pathway modulates cellular redox status, inflammatory responses, and cell survival. The HO-1 enzyme, together with the scaffold protein caveolin 1 (CAV-1), also acts as a negative regulator of TLR4 signaling in MΦs. Here, we demonstrate that in LPS-challenged CF MΦs, HO-1 does not compartmentalize normally to the cell surface and instead accumulates intracellularly. The abnormal HO-1 localization in CF MΦs in response to LPS is due to decreased CAV-1 expression, which is controlled by the cellular oxidative state, and is required for HO-1 delivery to the cell surface. Overexpression of HO-1 or stimulating the pathway with CO-releasing molecules (CORM2)enhancesCAV-1 expression in CF MΦs, suggesting a positive-feed forward loop between HO-1/CO induction and CAV-1 expression. These manipulations reestablished HO-1 and CAV-1 cell surface localization in CF MΦ's. Consistent with restoration of HO-1/CAV-1 negative regulation of TLR4 signaling, genetic or pharmacological (CORM2)-induced enhancement of this pathway decreased the inflammatory response of CF MΦs and CF mice treated with LPS. In conclusion, our results demonstrate that the counter-regulatory HO-1/CO pathway, which is critical in balancing and limiting the inflammatory response, is defective in CF MΦs through a CAV-1-dependent mechanism, exacerbating the CF MΦ's response to LPS. This pathway could be a potential target for therapeutic intervention for CF lung disease. PMID:23606537

Pharmacological Inhibition of Host Heme Oxygenase-1 Suppresses Mycobacterium tuberculosis Infection In Vivo by a Mechanism Dependent on T Lymphocytes

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Diego L. Costa

2016-10-01

Full Text Available Heme oxygenase-1 (HO-1 is a stress response antioxidant enzyme which catalyzes the degradation of heme released during inflammation. HO-1 expression is upregulated in both experimental and human Mycobacterium tuberculosis infection, and in patients it is a biomarker of active disease. Whether the enzyme plays a protective versus pathogenic role in tuberculosis has been the subject of debate. To address this controversy, we administered tin protoporphyrin IX (SnPPIX, a well-characterized HO-1 enzymatic inhibitor, to mice during acute M. tuberculosis infection. These SnPPIX-treated animals displayed a substantial reduction in pulmonary bacterial loads comparable to that achieved following conventional antibiotic therapy. Moreover, when administered adjunctively with antimycobacterial drugs, the HO-1 inhibitor markedly enhanced and accelerated pathogen clearance. Interestingly, both the pulmonary induction of HO-1 expression and the efficacy of SnPPIX treatment in reducing bacterial burden were dependent on the presence of host T lymphocytes. Although M. tuberculosis expresses its own heme-degrading enzyme, SnPPIX failed to inhibit its enzymatic activity or significantly restrict bacterial growth in liquid culture. Together, the above findings reveal mammalian HO-1 as a potential target for host-directed monotherapy and adjunctive therapy of tuberculosis and identify the immune response as a critical regulator of this function.

Epalrestat increases glutathione, thioredoxin, and heme oxygenase-1 by stimulating Nrf2 pathway in endothelial cells

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Kaori Yama

2015-04-01

Full Text Available Epalrestat (EPS is the only aldose reductase inhibitor that is currently available for the treatment of diabetic neuropathy. Recently, we found that EPS at near-plasma concentration increases the intracellular levels of glutathione (GSH in rat Schwann cells. GSH plays a crucial role in protecting endothelial cells from oxidative stress, thereby preventing vascular diseases. Here we show that EPS increases GSH levels in not only Schwann cells but also endothelial cells. Treatment of bovine aortic endothelial cells (BAECs, an in vitro model of the vascular endothelium, with EPS caused a dramatic increase in intracellular GSH levels. This was concomitant with the up-regulation of glutamate cysteine ligase, an enzyme catalyzing the first and rate-limiting step in de novo GSH synthesis. Moreover, EPS stimulated the expression of thioredoxin and heme oxygenase-1, which have important redox regulatory functions in endothelial cells. Nuclear factor erythroid 2-related factor 2 (Nrf2 is a key transcription factor that regulates the expression of antioxidant genes. EPS increased nuclear Nrf2 levels in BAECs. Nrf2 knockdown by siRNA suppressed the EPS-induced glutamate cysteine ligase, thioredoxin-1, and heme oxygenase-1 expression. Interestingly, LY294002, an inhibitor of phosphatidylinositol 3-kinase, abolished the EPS-stimulated GSH synthesis, suggesting that the kinase is associated with Nrf2 activation induced by EPS. Furthermore, EPS reduced the cytotoxicity induced by H2O2 and tert-butylhydroperoxide, indicating that EPS plays a role in protecting cells from oxidative stress. Taken together, the results provide evidence that EPS exerts new beneficial effects on endothelial cells by increasing GSH, thioredoxin, and heme oxygenase-1 levels through the activation of Nrf2. We suggest that EPS has the potential to prevent several vascular diseases caused by oxidative stress.

Heme-Oxygenase-1 Expression Contributes to the Immunoregulation Induced by Fasciola hepatica and Promotes Infection

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Paula Carasi

2017-07-01

Full Text Available Fasciola hepatica, also known as the liver fluke, is a trematode that infects livestock and humans causing fasciolosis, a zoonotic disease of increasing importance due to its worldwide distribution and high economic losses. This parasite immunoregulates the host immune system by inducing a strong Th2 and regulatory T immune response by immunomodulating dendritic cell (DC maturation and alternative activation of macrophages. In this paper, we show that F. hepatica infection in mice induces the upregulation of heme-oxygenase-1 (HO-1, the rate-limiting enzyme in the catabolism of free heme that regulates the host inflammatory response. We show and characterize two different populations of antigen presenting cells that express HO-1 during infection in the peritoneum of infected animals. Cells that expressed high levels of HO-1 expressed intermediate levels of F4/80 but high expression of CD11c, CD38, TGFβ, and IL-10 suggesting that they correspond to regulatory DCs. On the other hand, cells expressing intermediate levels of HO-1 expressed high levels of F4/80, CD68, Ly6C, and FIZZ-1, indicating that they might correspond to alternatively activated macrophages. Furthermore, the pharmacological induction of HO-1 with the synthetic metalloporphyrin CoPP promoted F. hepatica infection increasing the clinical signs associated with the disease. In contrast, treatment with the HO-1 inhibitor SnPP protected mice from parasite infection, indicating that HO-1 plays an essential role during F. hepatica infection. Finally, HO-1 expression during F. hepatica infection was associated with TGFβ and IL-10 levels in liver and peritoneum, suggesting that HO-1 controls the expression of these immunoregulatory cytokines during infection favoring parasite survival in the host. These results contribute to the elucidation of the immunoregulatory mechanisms induced by F. hepatica in the host and provide alternative checkpoints to control fasciolosis.

Isocyanides inhibit human heme oxygenases at the verdoheme stage.

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Evans, John P; Kandel, Sylvie; Ortiz de Montellano, Paul R

2009-09-22

Heme oxygenases (HO) catalyze the oxidative cleavage of heme to generate biliverdin, CO, and free iron. In humans, heme oxygenase-1 (hHO-1) is overexpressed in tumor tissues, where it helps to protect cancer cells from anticancer agents, while HOs in fungal pathogens, such as Candida albicans, function as the primary means of iron acquisition. Thus, HO can be considered a potential therapeutic target for certain diseases. In this study, we have examined the equilibrium binding of three isocyanides, isopropyl, n-butyl, and benzyl, to the two major human HO isoforms (hHO-1 and hHO-2), Candida albicans HO (CaHmx1), and human cytochrome P450 CYP3A4 using electronic absorption spectroscopy. Isocyanides coordinate to both ferric and ferrous HO-bound heme, with tighter binding by the more hydrophobic isocyanides and 200-300-fold tighter binding to the ferrous form. Benzyl isocyanide was the strongest ligand to ferrous heme in all the enzymes. Because the dissociation constants (KD) of the ligands for ferrous heme-hHO-1 were below the limit of accuracy for equilibrium titrations, stopped-flow kinetic experiments were used to measure the binding parameters of the isocyanides to ferrous hHO-1. Steady-state activity assays showed that benzyl isocyanide was the most potent uncompetitive inhibitor with respect to heme with a KI = 0.15 microM for hHO-1. Importantly, single turnover assays revealed that the reaction was completely stopped by coordination of the isocyanide to the verdoheme intermediate rather than to the ferric heme complex. Much tighter binding of the inhibitor to the verdoheme intermediate differentiates it from inhibition of, for example, CYP3A4 and offers a possible route to more selective inhibitor design.

Isocyanides Inhibit Human Heme Oxygenases at the Verdoheme Stage†

Science.gov (United States)

Evans, John P.; Kandel, Sylvie; Ortiz de Montellano, Paul R.

2010-01-01

Heme oxygenases (HO) catalyze the oxidative cleavage of heme to generate biliverdin, CO, and free iron. In humans, heme oxygenase-1 (hHO-1) is overexpressed in tumor tissues, where it helps to protect cancer cells from anticancer agents, while HOs in fungal pathogens, such as Candida albicans, function as the primary means of iron acquisition. Thus, HO can be considered a potential therapeutic target for certain diseases. In this study, we have examined the equilibrium binding of three isocyanides; isopropyl, n-butyl, and benzyl, to the two major human HO isoforms (hHO-1 and hHO-2), Candida albicans HO (CaHmx1), and human cytochrome P450 CYP3A4 using electronic absorption spectroscopy. Isocyanides coordinate to both ferric and ferrous HO-bound heme, with tighter binding by the more hydrophobic isocyanides, and 200-300-fold tighter binding to the ferrous form. Benzyl isocyanide was the strongest ligand to ferrous heme in all the enzymes. Because the dissociation constants (KD) of the ligands for ferrous heme-hHO-1 were below the limit of accuracy for equilibrium titrations, stopped-flow kinetic experiments were used to measure the binding parameters of the isocyanides to ferrous hHO-1. Steady-state activity assays showed that benzyl isocyanide was the most potent uncompetitive inhibitor with respect to heme with a KI = 0.15 μM for hHO-1. Importantly, single turnover assays revealed that the reaction was completely stopped by coordination of the isocyanide to the verdoheme intermediate rather than to the ferric heme complex. Much tighter binding of the inhibitor to the verdoheme intermediate differentiates it from inhibition of, for example, CYP3A4 and offers a possible route to more selective inhibitor design. PMID:19694439

Heme oxygenase-1 deletion affects stress erythropoiesis.

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Yu-An Cao

Full Text Available Homeostatic erythropoiesis leads to the formation of mature red blood cells under non-stress conditions, and the production of new erythrocytes occurs as the need arises. In response to environmental stimuli, such as bone marrow transplantation, myelosuppression, or anemia, erythroid progenitors proliferate rapidly in a process referred to as stress erythropoiesis. We have previously demonstrated that heme oxygenase-1 (HO-1 deficiency leads to disrupted stress hematopoiesis. Here, we describe the specific effects of HO-1 deficiency on stress erythropoiesis.We used a transplant model to induce stress conditions. In irradiated recipients that received hmox(+/- or hmox(+/+ bone marrow cells, we evaluated (i the erythrocyte parameters in the peripheral blood; (ii the staining intensity of CD71-, Ter119-, and CD49d-specific surface markers during erythroblast differentiation; (iii the patterns of histological iron staining; and (iv the number of Mac-1(+-cells expressing TNF-α. In the spleens of mice that received hmox(+/- cells, we show (i decreases in the proerythroblast, basophilic, and polychromatophilic erythroblast populations; (ii increases in the insoluble iron levels and decreases in the soluble iron levels; (iii increased numbers of Mac-1(+-cells expressing TNF-α; and (iv decreased levels of CD49d expression in the basophilic and polychromatophilic erythroblast populations.As reflected by effects on secreted and cell surface proteins, HO-1 deletion likely affects stress erythropoiesis through the retention of erythroblasts in the erythroblastic islands of the spleen. Thus, HO-1 may serve as a therapeutic target for controlling erythropoiesis, and the dysregulation of HO-1 may be a predisposing condition for hematologic diseases.

Ginsenoside Rb1 protects against 6-hydroxydopamine-induced oxidative stress by increasing heme oxygenase-1 expression through an estrogen receptor-related PI3K/Akt/Nrf2-dependent pathway in human dopaminergic cells

International Nuclear Information System (INIS)

Hwang, Yong Pil; Jeong, Hye Gwang

2010-01-01

Phytoestrogens are polyphenolic non-steroidal plant compounds with estrogen-like biological activity. Ginseng, the root of Panax ginseng C.A. Meyer (Araliaceae), is a popular traditional herbal medicine. Ginsenoside Rb1 (Rb1), an active component commonly found in ginseng root, is a phytoestrogen that exerts estrogen-like activity. In this study, we demonstrate that the phytoestrogen Rb1 inhibits 6-hydroxydopamine (6-OHDA)-induced oxidative injury via an ER-dependent Gβ1/PI3K/Akt and heme oxygenase-1 (HO-1) pathway. Pretreatment of SH-SY5Y cells with Rb1 significantly reduced 6-OHDA-induced caspase-3 activation and subsequent cell death. Rb1 also up-regulated HO-1 expression, which conferred cytoprotection against 6-OHDA-induced oxidative injury. Moreover, Rb1 induced both Nrf2 nuclear translocation, which is upstream of HO-1 expression and PI3K activation, a pathway that is involved in induced Nrf2 nuclear translocation, HO-1 expression and cytoprotection. Also, Rb1-mediated increases in PI3K activation and HO-1 induction were reversed by co-treatment with ICI 182,780 and pertussis toxin. Taken together, these results suggest that Rb1 augments the cellular antioxidant defenses through ER-dependent HO-1 induction via the Gβ1/PI3K/Akt-Nrf2 signaling pathway, thereby protecting cells from oxidative stress. Thus our study indicates that Rb1 has a partial cytoprotective role in dopaminergic cell culture systems.

Serum heme oxygenase-1 levels in patients with primary dysmenorrhea.

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Aksoy, Ayse Nur; Laloglu, Esra; Ozkaya, Alev Lazoglu; Yilmaz, Emsal Pınar Topdagi

2017-04-01

Primary dysmenorrhea effects the life-quality of women negatively. The aim of this study was to evaluate heme oxygenase-1 (HO1) activity together with malondialdehyde (MDA) and nitric oxide (NO) levels in patients with primary dysmenorrhea. A total of 28 nulliparous women with the diagnosis of primary dysmenorrhea and 26 healthy controls were included in this study. On the first day of menstruation, all patients underwent ultrasound examination to exclude pelvic pathology and the visual analogue scale was applied to patients. Patient's visual analogue scale (VAS) scores, age, body mass index (BMI), menstrual cycle length (day), length of bleeding (day) were recorded. In the same day, fasting blood samples were taken from each patient for biochemical analysis. Serum MDA, NO and HO1 levels were found to be higher in women with primary dysmenorrhea compared to healthy controls (p = 0.012, p = 0.009, p dysmenorrhea. Antioxidant support might be helpful to reduce pain severity in primary dysmenorrhea.

4-Hydroxyestradiol induces mammary epithelial cell transformation through Nrf2-mediated heme oxygenase-1 overexpression

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Park, Sin-Aye; Lee, Mee-Hyun; Na, Hye-Kyung; Surh, Young-Joon

2016-01-01

Estrogen (17?-estradiol, E2) undergoes oxidative metabolism by CYP1B1 to form 4-hydroxyestradiol (4-OHE2), a putative carcinogenic metabolite of estrogen. Our previous study showed that 4-OHE2-induced production of reactive oxygen species contributed to neoplastic transformation of human breast epithelial (MCF-10A) cells. In this study, 4-OHE2, but not E2, increased the expression of heme oxygenase-1 (HO-1), a sensor and regulator of oxidative stress, in MCF-10A cells. Silencing the HO-1 gene...

Evidence-based prescription for cyclo-oxygenase-2 inhibitors in ...

African Journals Online (AJOL)

to the different metabolites generated by the cyclo-oxygenase-1. (COX-1) and ... have shown equivalent risk in non-NSAID users in developing congestive heart ... http://www.drgavinshang.co.za/wp-content/uploads/2012/11/NSAIDs-and-.

Near field resonant inductive coupling to power electronic devices dispersed in water

NARCIS (Netherlands)

Kuipers, J.; Bruning, H.; Bakker, S.; Rijnaarts, H.H.M.

2012-01-01

The purpose of this research was to investigate inductive coupling as a way to wirelessly power electronic devices dispersed in water. The most important parameters determining this efficiency are: (1) the coupling between transmitting and receiving coils, (2) the quality factors of the transmitting

Optical modeling of induction-linac driven free-electron lasers

International Nuclear Information System (INIS)

Scharlemann, E.T.; Fawley, W.M.

1986-01-01

The free-electron laser (FEL) simulation code FRED, developed at Lawrence Livermore National Laboratory (LLNL) primarily to model single-pass FEL amplifiers driven by induction linear accelerators, is described. The main emphasis is on the modeling of optical propagation in the laser and on the differences between the requirements for modeling rf-linac-driven vs. induction-linac-driven FELs. Examples of optical guiding and mode cleanup are presented for a 50 μm FEL

Identification of the large subunit of Ribulose 1,5-bisphosphate carboxylase/oxygenase as a substrate for transglutaminase in Medicageo sativa L. (alfalfa)

International Nuclear Information System (INIS)

Margosiak, S.A.; Dharma, A.; Carver, M.R.B.; Gonzales, A.P.; Louie, D.; Kuehn, G.D.

1990-01-01

Extract prepared from floral meristematic tissue of alfalfa (Medicago sativa L.) were investigated for expression of the enzyme transglutaminase in order to identify the major protein substrate for transglutaminase-directed modifications among plant proteins. The large polymorphic subunits of ribulose 1,5-bisphosphate carboxylase/oxygenase in alfalfa, with molecular weights of 52,700 and 57,600, are major substrates for transglutaminase in these extracts. This was established by: (a) covalent conjugation of monodansylcadaverine to the large subunit followed by fluorescent detection in SDS-polyacrylamide gels; (b) covalent conjugation of [ 14 C]putrescine to the large subunit with detection by autoradiography; (c) covalent conjugation of monodansylcadaverine to the large subunit and demonstration of immunocross-reactivity on nitrocellulose transblot of the modified large subunit with antibody prepared in rabbits against dansylated-ovalbumin; (d) demonstration of a direct dependence of the rate of transglutaminase-mediated, [ 14 C]putresciene incorporation upon the concentration of ribulose, 1,5-bisphosphate carboxylase/oxygenase from alfalfa or spinach; and (e) presumptive evidence from size exclusion chromatography that transglutaminase may cofractionate with native molecules of ribulose 1,5-bisphosphate carboxylase/oxygenase in crude extracts

Free electron laser amplifier driven by an induction linac

International Nuclear Information System (INIS)

Neil, V.K.

1986-01-01

This paper discusses the use of a free-electron laser amplifier as a means of converting the kinetic energy of an electron beam into coherent radiation. In particular, the use of an induction linear accelerator is discussed. The motion of the elections in the tapered and untapered wiggler magnets is discussed as well as the beam emittance, and the radiation fields involved

Rapid, convenient method for screening imidazole-containing compounds for heme oxygenase inhibition.

Science.gov (United States)

Vlahakis, Jason Z; Rahman, Mona N; Roman, Gheorghe; Jia, Zongchao; Nakatsu, Kanji; Szarek, Walter A

2011-01-01

Sensitive assays for measuring heme oxygenase activity have been based on the gas-chromatographic detection of carbon monoxide using elaborate, expensive equipment. The present study describes a rapid and convenient method for screening imidazole-containing candidates for inhibitory activity against heme oxygenase using a plate reader, based on the spectroscopic evaluation of heme degradation. A PowerWave XS plate reader was used to monitor the absorbance (as a function of time) of heme bound to purified truncated human heme oxygenase-1 (hHO-1) in the individual wells of a standard 96-well plate (with or without the addition of a test compound). The degradation of heme by heme oxygenase-1 was initiated using l-ascorbic acid, and the collected relevant absorbance data were analyzed by three different methods to calculate the percent control activity occurring in wells containing test compounds relative to that occurring in control wells with no test compound present. In the cases of wells containing inhibitory compounds, significant shifts in λ(max) from 404 to near 412 nm were observed as well as a decrease in the rate of heme degradation relative to that of the control. Each of the three methods of data processing (overall percent drop in absorbance over 1.5h, initial rate of reaction determined over the first 5 min, and estimated pseudo first-order reaction rate constant determined over 1.5h) gave similar and reproducible results for percent control activity. The fastest and easiest method of data analysis was determined to be that using initial rates, involving data acquisition for only 5 min once reactions have been initiated using l-ascorbic acid. The results of the study demonstrate that this simple assay based on the spectroscopic detection of heme represents a rapid, convenient method to determine the relative inhibitory activity of candidate compounds, and is useful in quickly screening a series or library of compounds for heme oxygenase inhibition

The cytoprotective enzyme heme oxygenase-1 suppresses Ebola virus replication.

Science.gov (United States)

Hill-Batorski, Lindsay; Halfmann, Peter; Neumann, Gabriele; Kawaoka, Yoshihiro

2013-12-01

Ebola virus (EBOV) is the causative agent of a severe hemorrhagic fever in humans with reported case fatality rates as high as 90%. There are currently no licensed vaccines or antiviral therapeutics to combat EBOV infections. Heme oxygenase-1 (HO-1), an enzyme that catalyzes the rate-limiting step in heme degradation, has antioxidative properties and protects cells from various stresses. Activated HO-1 was recently shown to have antiviral activity, potently inhibiting the replication of viruses such as hepatitis C virus and human immunodeficiency virus. However, the effect of HO-1 activation on EBOV replication remains unknown. To determine whether the upregulation of HO-1 attenuates EBOV replication, we treated cells with cobalt protoporphyrin (CoPP), a selective HO-1 inducer, and assessed its effects on EBOV replication. We found that CoPP treatment, pre- and postinfection, significantly suppressed EBOV replication in a manner dependent upon HO-1 upregulation and activity. In addition, stable overexpression of HO-1 significantly attenuated EBOV growth. Although the exact mechanism behind the antiviral properties of HO-1 remains to be elucidated, our data show that HO-1 upregulation does not attenuate EBOV entry or budding but specifically targets EBOV transcription/replication. Therefore, modulation of the cellular enzyme HO-1 may represent a novel therapeutic strategy against EBOV infection.

Heme oxygenase attenuates angiotensin II-mediated superoxide production in cultured mouse thick ascending loop of Henle cells.

Science.gov (United States)

Kelsen, Silvia; Patel, Bijal J; Parker, Lawson B; Vera, Trinity; Rimoldi, John M; Gadepalli, Rama S V; Drummond, Heather A; Stec, David E

2008-10-01

Heme oxygenase (HO)-1 induction can attenuate the development of angiotensin II (ANG II)-dependent hypertension. However, the mechanism by which HO-1 lowers blood pressure is not clear. The goal of this study was to test the hypothesis that induction of HO-1 can reduce the ANG II-mediated increase in superoxide production in cultured thick ascending loop of Henle (TALH) cells. Studies were performed on an immortalized cell line of mouse TALH (mTALH) cells. HO-1 was induced in cultured mTALH cells by treatment with cobalt protoporphyrin (CoPP, 10 microM) or hemin (50 microM) or by transfection with a plasmid containing the human HO-1 isoform. Treatment of mTALH cells with 10(-9) M ANG II increased dihydroethidium (DHE) fluorescence (an index of superoxide levels) from 35.5+/-5 to 136+/-18 relative fluorescence units (RFU)/microm2. Induction of HO-1 via CoPP, hemin, or overexpression of the human HO-1 isoform significantly reduced ANG II-induced DHE fluorescence to 64+/-5, 64+/-8, and 41+/-4 RFU/microm2, respectively. To determine which metabolite of HO-1 is responsible for reducing ANG II-mediated increases in superoxide production in mTALH cells, cells were preincubated with bilirubin or carbon monoxide (CO)-releasing molecule (CORM)-A1 (each at 100 microM) before exposure to ANG II. DHE fluorescence averaged 80+/-7 RFU/microm2 after incubation with ANG II and was significantly decreased to 55+/-7 and 53+/-4 RFU/microm2 after pretreatment with bilirubin and CORM-A1. These results demonstrate that induction of HO-1 in mTALH cells reduces the levels of ANG II-mediated superoxide production through the production of both bilirubin and CO.

Identification of Interactions between Abscisic Acid and Ribulose-1,5-Bisphosphate Carboxylase/Oxygenase.

Directory of Open Access Journals (Sweden)

Marek M Galka

Full Text Available Abscisic acid ((+-ABA is a phytohormone involved in the modulation of developmental processes and stress responses in plants. A chemical proteomics approach using an ABA mimetic probe was combined with in vitro assays, isothermal titration calorimetry (ITC, x-ray crystallography and in silico modelling to identify putative (+-ABA binding-proteins in crude extracts of Arabidopsis thaliana. Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco was identified as a putative ABA-binding protein. Radiolabelled-binding assays yielded a Kd of 47 nM for (+-ABA binding to spinach Rubisco, which was validated by ITC, and found to be similar to reported and experimentally derived values for the native ribulose-1,5-bisphosphate (RuBP substrate. Functionally, (+-ABA caused only weak inhibition of Rubisco catalytic activity (Ki of 2.1 mM, but more potent inhibition of Rubisco activation (Ki of ~ 130 μM. Comparative structural analysis of Rubisco in the presence of (+-ABA with RuBP in the active site revealed only a putative low occupancy (+-ABA binding site on the surface of the large subunit at a location distal from the active site. However, subtle distortions in electron density in the binding pocket and in silico docking support the possibility of a higher affinity (+-ABA binding site in the RuBP binding pocket. Overall we conclude that (+-ABA interacts with Rubisco. While the low occupancy (+-ABA binding site and weak non-competitive inhibition of catalysis may not be relevant, the high affinity site may allow ABA to act as a negative effector of Rubisco activation.

Increased Plasma Levels of Heme Oxygenase-1 in Human Brucellosis.

Science.gov (United States)

Chen, Zhe; Zhang, Yu-Xue; Fu, Dong-Wei; Gao, Qing-Feng; Ge, Feng-Xia; Liu, Wei-Hua

2016-08-01

Brucellosis is associated with inflammation and the oxidative stress response. Heme oxygenase-1 (HO-1) is a cytoprotective stress-responsive enzyme that has anti-inflammatory and anti-oxidant effects. Nevertheless, the role of HO-1 in human brucellosis has not yet been studied. The aim of this study was to examine the plasma levels of HO-1 in patients with brucellosis and to evaluate the ability of plasma HO-1 levels as an auxiliary diagnosis, a severity predictor, and a monitor for brucellosis treatments. A total of 75 patients with brucellosis were divided into the acute, subacute, chronic active, and chronic stable groups. An additional 20 volunteers were included as the healthy control group. The plasma HO-1 levels and other laboratory parameters were measured in all groups. Furthermore, the plasma levels of HO-1 in the acute group were compared before and after treatment. The plasma HO-1 levels were considerably increased in the acute (4.97 ± 3.55), subacute (4.98 ± 3.23), and chronic active groups (4.43 ± 3.00) with brucellosis compared to the healthy control group (1.03 ± 0.63) (p brucellosis (r = 0.707, p brucellosis status and may be used as a supplementary plasma marker for diagnosing brucellosis and monitoring its treatment.

Studies on enzymes of C-4 pathway : Part V - Comparative studies of RUP2 carboxylase/oxygenase from maize and spinach

International Nuclear Information System (INIS)

Ramakrishna, J.; Bhagwat, A.S.; Sane, P.V.

1978-01-01

RuP 2 carboxylase (EC 4.1.1.39) isolated from maize, a C-4 plant possessed oxygenase activity. The ratio of carboxylase/oxygenase in the case of maize enzyme was more than 2-fold as compared to that of spinach. Fructose-1 6-diphosphate preferentially inhibited oxygenase function of the RuP 2 carboxylase/oxygenase in both the species when both the activities were assayed under identical conditions of pH, temperature, MgCl 2 , O 2 and RuP 2 concentration. Frutose-1, 6-diphosphate showed a fully competitive inhibition with respect to RuP 2 in the case of spinach, however the maize enzyme was inhibited seminoncompetitively. ( 14 C)-HCO 3 was used in the carboxylase assay. (author)

The damage of the hepatic mixed functional oxygenase system by CCI4

International Nuclear Information System (INIS)

Fander, U.

1981-01-01

The relation between incorporation of C-14 from C-14-Cl 4 into liver lipids and the damage of the mixed functional oxygenase system of liver microsomes is investigated in rats depending on sex difference and method of pretreatment. Under the respective conditions of pretreatment C-14-incorporation rate and relative decrease of the cytochrome P-450 level as the parameter most influenced by CCl 4 are compared with untreated female rats. Induction by 3-MC does not alter both the parameters. Induction by PB enhances the C-14-incorporation rate as well as the cytochrome P-450 decrease but the latter is more affected. In male rats there is only the C-14-incorporation rate increased. Vitamine D 3 pretreated rats show a less decrease of cytochrome P-450 but an enhanced C-14 incorporation rate. Therefore there is no correlation between cytochrome P-450 decrease and C-14 incorporation rate. Reasons for the lack of that correlation are discussed with regard to the mechanism of liver cell damage by carbon tetrachloride. (orig./MG)

A novel compound derived from danshensu inhibits apoptosis via upregulation of heme oxygenase-1 expression in SH-SY5Y cells.

Science.gov (United States)

Pan, Li-Long; Liu, Xin-Hua; Jia, Yao-Ling; Wu, Dan; Xiong, Qing-Hui; Gong, Qi-Hai; Wang, Yang; Zhu, Yi-Zhun

2013-04-01

Heme oxygenase-1 (HO-1) has potential anti-apoptotic properties. A novel compound [4-(2-acetoxy-3-((R)-3-(benzylthio)-1-methoxy-1-oxopropan-2- ylamino)-3-oxopropyl)-1,2-phenylene diacetate (DSC)] was synthesized by joining danshensu and cysteine through an appropriate linker. This study investigated if the cytoprotective properties of DSC involved the induction of HO-1. We evaluated the cytoprotective effects of DSC on H2O2-induced cell damage, apoptosis, intracellular and mitochondrial reactive oxygen species (ROS) production, mitochondrial membrane potential (ΔΨm) loss, and apoptosis-related proteins expression and its underlying mechanisms. DSC concentration-dependently attenuated cell death, lactate dehydrogenase release, intracellular and mitochondrial ROS production, and ΔΨm collapse, modulated apoptosis-related proteins (Bcl-2, Bax, caspase-3, p53, and cleaved PARP) expression, and inhibited phosphorylation of extracellular signal-regulated kinase 1/2 in SH-SY5Y cells induced by H2O2. In addition, DSC concentration-dependently induced HO-1 expression associated with nuclear translocation of nuclear factor-erythroid 2 related factor 2 (Nrf-2), while the effect of DSC was inhibited by a phosphoinositide 3-kinase (PI3K) inhibitor LY294002. Furthermore, the protective effect of DSC on H2O2-induced cell death was abolished by HO-1 inhibitor ZnPP, but was mimicked by carbon monoxide-releasing moiety CORM-3 or HO-1 by-product bilirubin. Finally, DSC inhibited H2O2-induced changes of Bcl-2, Bax, and caspase-3 expression, and all of these effects were reversed by HO-1 silencing. Induction of HO-1 may be, at least in part, responsible for the anti-apoptotic property of DSC, an effect that involved the activation of PI3K/Akt/Nrf-2 axis. DSC might have the potential for beneficial therapeutic interventions for neurodegenerative diseases. Copyright © 2013. Published by Elsevier B.V.

Diabetes Impairs the Vascular Recruitment of Normal Stem Cells by Oxidant Damage, Reversed by Increases in pAMPK, Heme Oxygenase-1, and Adiponectin

Science.gov (United States)

Sambuceti, Gianmario; Morbelli, Silvia; Vanella, Luca; Kusmic, Claudia; Marini, Cecilia; Massollo, Michela; Augeri, Carla; Corselli, Mirko; Ghersi, Chiara; Chiavarina, Barbara; Rodella, Luigi F; L'Abbate, Antonio; Drummond, George; Abraham, Nader G; Frassoni, Francesco

2009-01-01

Background Atherosclerosis progression is accelerated in diabetes mellitus (DM) by either direct endothelial damage or reduced availability and function of endothelial progenitor cells (EPCs). Both alterations are related to increased oxidant damage. Aim We examined if DM specifically impairs vascular signaling, thereby reducing the recruitment of normal EPCs, and if increases in antioxidant levels by induction of heme oxygenase-1 (HO-1) can reverse this condition. Methods Control and diabetic rats were treated with the HO-1 inducer cobalt protoporphyrin (CoPP) once a week for 3 weeks. Eight weeks after the development of diabetes, EPCs harvested from the aorta of syngenic inbred normal rats and labeled with technetium-99m-exametazime were infused via the femoral vein to estimate their blood clearance and aortic recruitment. Circulating endothelial cells (CECs) and the aortic expression of thrombomodulin (TM), CD31, and endothelial nitric oxide synthase (eNOS) were used to measure endothelial damage. Results DM reduced blood clearance and aortic recruitment of EPCs. Both parameters were returned to control levels by CoPP treatment without affecting EPC kinetics in normal animals. These abnormalities of EPCs in DM were paralleled by reduced serum adiponectin levels, increased numbers of CECs, reduced endothelial expression of phosphorylated eNOS, and reduced levels of TM, CD31, and phosphorylated AMP-activated protein kinase (pAMPK). CoPP treatment restored all of these parameters to normal levels. Conclusion Type II DM and its related oxidant damage hamper the interaction between the vascular wall and normal EPCs by mechanisms that are, at least partially, reversed by the induction of HO-1 gene expression, adiponectin, and pAMPK levels. PMID:19038792

Heme oxygenase is not involved in the anti-proliferative effects of statins on pancreatic cancer cells

International Nuclear Information System (INIS)

Vanova, K.; Boukalova, S.; Gbelcova, H.; Muchova, L.; Neuzil, J.; Gurlich, R.; Ruml, T.; Vitek, L.

2016-01-01

Pancreatic cancer is recognized as one of the most fatal tumors due to its aggressiveness and resistance to therapy. Statins were previously shown to inhibit the proliferation of cancer cells via various signaling pathways. In healthy tissues, statins activate the heme oxygenase pathway, nevertheless the role of heme oxygenase in pancreatic cancer is still controversial. The aim of this study was to evaluate, whether anti-proliferative effects of statins in pancreatic cancer cells are mediated via the heme oxygenase pathway. In vitro effects of various statins and hemin, a heme oxygenase inducer, on cell proliferation were evaluated in PA-TU-8902, MiaPaCa-2 and BxPC-3 human pancreatic cancer cell lines. The effect of statins on heme oxygenase activity was assessed and heme oxygenase-silenced cells were used for pancreatic cancer cell proliferation studies. Cell death rate and reactive oxygen species production were measured in PA-TU-8902 cells, followed by evaluation of the effect of cerivastatin on GFP-K-Ras trafficking and expression of markers of invasiveness, osteopontin (SPP1) and SOX2. While simvastatin and cerivastatin displayed major anti-proliferative properties in all cell lines tested, pravastatin did not affect the cell growth at all. Strong anti-proliferative effect was observed also for hemin. Co-treatment of cerivastatin and hemin increased anti-proliferative potential of these agents, via increased production of reactive oxygen species and cell death compared to individual treatment. Heme oxygenase silencing did not prevent pancreatic cancer cells from the tumor-suppressive effect of cerivastatin or hemin. Cerivastatin, but not pravastatin, protected Ras protein from trafficking to the cell membrane and significantly reduced expressions of SPP1 (p < 0.05) and SOX2 (p < 0.01). Anti-proliferative effects of statins and hemin on human pancreatic cancer cell lines do not seem to be related to the heme oxygenase pathway. While hemin triggers reactive

Anti-neuroinflammatory effect of 6,8,1'-tri-O-methylaverantin, a metabolite from a marine-derived fungal strain Aspergillus sp., via upregulation of heme oxygenase-1 in lipopolysaccharide-activated microglia.

Science.gov (United States)

Kim, Kwan-Woo; Kim, Hye Jin; Sohn, Jae Hak; Yim, Joung Han; Kim, Youn-Chul; Oh, Hyuncheol

2018-02-01

In the course of searching for anti-neuroinflammatory metabolites from marine-derived fungi, three fungal metabolites, 6,8,1'-tri-O-methylaverantin, 6,8-di-O-methylaverufin, and 5-methoxysterigmatocystin were isolated from a marine-derived fungal strain Aspergillus sp. SF-6796. Among these, 6,8,1'-tri-O-methylaverantin induced the expression of heme oxygenase (HO)-1 protein in BV2 microglial cells. The induction of HO-1 protein was mediated by the activation of nuclear transcription factor erythroid-2 related factor 2 (Nrf2), and was regulated by the p38 mitogen-activated protein kinase and phosphatidylinositol 3-kinase/protein kinase B signaling pathways. Furthermore, 6,8,1'-tri-O-methylaverantin suppressed the overproduction of pro-inflammatory mediators, such as nitric oxide, prostaglandin E 2 , inducible nitric oxide synthase, and cyclooxygenase-2 in lipopolysaccharide (LPS)-stimulated BV2 microglial cells. These anti-neuroinflammatory effects were mediated through the negative regulation of the nuclear factor kappa B pathway, repressing the phosphorylation and degradation of inhibitor kappa B-α, translocation into the nucleus of p65/p50 heterodimer, and DNA-binding activity of p65 subunit. The anti-neuroinflammatory effect of 6,8,1'-tri-O-methylaverantin was partially blocked by a selective HO-1 inhibitor, suggesting that its anti-neuroinflammatory effect is at least partly mediated by HO-1 induction. In this study, 6,8,1'-tri-O-methylaverantin also induced HO-1 protein expression in primary microglial cells, and this correlated with anti-neuroinflammatory effects observed in LPS-stimulated primary microglial cells. In conclusion, 6,8,1'-tri-O-methylaverantin represents a potential candidate for use in the development of therapeutic agents for the regulation of neuroinflammation in neurodegenerative diseases. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effects of Metalloporphyrins on Heme Oxygenase-1 Transcription: Correlative Cell Culture Assays Guide in Vivo Imaging

OpenAIRE

Monica Hajdena-Dawson; Weisheng Zhang; Pamela R. Contag; Ronald J. Wong; Hendrik J. Vreman; David K. Stevenson; Christopher H. Contag

2003-01-01

Heme oxygenase (HO) is the rate-limiting step in the heme degradation pathway and is a potential target for the control, or prevention, of pathologic jaundice in neonates. Metalloporphyrins (Mps), a diverse set of synthetic derivatives of heme, can competitively inhibit the HO enzymes. However, certain Mps are phototoxic and some increase transcription of HO-1, the inducible HO isozyme. Therefore, effective development of this class of compounds as therapeutics for treating pathologic jaundic...

Anti-inflammatory effect of transduced PEP-1-heme oxygenase-1 in Raw 264.7 cells and a mouse edema model

International Nuclear Information System (INIS)

Kwon, Soon Won; Sohn, Eun Jeong; Kim, Dae Won; Jeong, Hoon Jae; Kim, Mi Jin; Ahn, Eun Hee; Kim, Young Nam; Dutta, Suman; Kim, Duk-Soo; Park, Jinseu; Eum, Won Sik; Hwang, Hyun Sook; Choi, Soo Young

2011-01-01

Highlights: → Recombinant PEP-1 heme oxygenase-1 expression vector was constructed and overexpressed. → We investigated transduction efficiency of PEP-1-HO-1 protein in Raw 264.7 cells. → PEP-1-HO-1 was efficiently transduced into Raw 264.7 cells in a dose and time dependent manner. → PEP-1-HO-1 exerted anti-inflammatory activity in Raw 264.7 cells and in a mice edema model. → PEP-1-HO-1 could be used as a therapeutic drug against inflammatory diseases. -- Abstract: Heme oxygenase-1 (HO-1), which catalyzes the degradation of free heme to biliverdin, carbon monoxide (CO), and free iron (Fe 2+ ), is up-regulated by several cellular stress and cell injuries, including inflammation, ischemia and hypoxia. In this study, we examined whether fusion of HO-1 with PEP-1, a protein transduction domain that is able to deliver exogenous molecules to living cells or tissues, would facilitate HO-1 delivery to target cells and tissues, and thereby effectively exert a therapeutically useful response against inflammation. Western blot analysis demonstrated that PEP-1-HO-1 fusion proteins were transduced into Raw 264.7 cells in time- and dose-dependent manners, and were stably maintained in the cells for about 60 h. In addition, fluorescence analysis revealed that only PEP-1-HO-1 fusion proteins were significantly transduced into the cytoplasm of cells, while HO-1 proteins failed to be transduced. In lipopolysaccharide (LPS)-stimulated Raw 264.7 cells and 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced mouse edema model, transduced PEP-1-HO-1 fusion proteins effectively inhibited the overexpression of pro-inflammatory mediators and cytokines. Also, histological analysis demonstrated that PEP-1-HO-1 remarkably suppressed ear edema. The results suggest that the PEP-1-HO-1 fusion protein can be used as a therapeutic molecule against reactive oxygen species-related inflammatory diseases.

Hemin inhibits NO production by IL-1β-stimulated human astrocytes through induction of heme oxygenase-1 and reduction of p38 MAPK activation

Directory of Open Access Journals (Sweden)

Sheng Wen S

2010-09-01

Full Text Available Abstract Background Heme oxygenase (HO-1 has been shown to attenuate oxidative injury and reduce apoptosis. HO-1 can be induced by various stimuli released during cellular injury, such as heme. Deleterious free heme is degraded by HO-1 to carbon monoxide, iron and biliverdin, which have potent anti-oxidant and anti-inflammatory properties. In this study, we tested the hypothesis that upregulation of HO-1 would inhibit production of the free radical (NO by interlukin (IL-1β-activated human astrocytes. Methods To measure NO production, inducible NO synthase (iNOS, HO-1 expression and mitogen-activated protein (MAP kinase activation we used hemin as an HO-1 inducer and tin protoporphyrin (SnPP IX as an inhibitor of HO-1 activity in human astrocyte cultures prior to IL-1β exposure. Transfection of astrocyte cultures was performed using a pLEX expression vector carrying the human HO-1 sequence prior to IL-1β treatment. Supernatants of astrocyte cultures pretreated with inhibitors of p38 MAPK or MEK1/2 prior to IL-1β exposure were collected for NO assay. Results IL-1β treatment of astrocytes alone induced undetectable amounts of HO-1 protein by western blot. However, HO-1 mRNA expression was modestly up-regulated in response to IL-1β stimulation. Pretreatment with hemin alone substantially induced both HO-1 mRNA and protein expression, and HO-1 mRNA expression was further enhanced when hemin was combined with IL-1β treatment. In contrast, IL-1β-induced iNOS mRNA expression and NO production were markedly inhibited by hemin treatment. When pretreated with SnPP, the inhibitory effect of hemin on IL-1β-induced NO production and iNOS expression was reversed, suggesting the involvement of HO-1. IL-1β-induced p38 MAPK activation, which is known to be required for NO production, was also down-regulated by hemin. Conclusion These findings support the hypothesis that up-regulation of HO-1 in astrocytes is associated with down-regulation of i

Electron and Negative Ion Densities in C2F6 and CHF3 Containing Inductively Coupled Discharges

International Nuclear Information System (INIS)

HEBNER, GREGORY A.; MILLER, PAUL A.

1999-01-01

Electron and negative ion densities have been measured in inductively coupled discharges containing C 2 F 6 and CHF 3 . Line integrated electron density was determined using a microwave interferometer, negative ion densities were inferred using laser photodetachment spectroscopy, and electron temperature was determined using a Langmuir probe. For the range of induction powers, pressures and bias power investigated, the electron density peaked at 9 x 10 12 cm -2 (line-integrated) or approximately 9 x 10 11 cm -3 . The negative ion density peaked at approximately 1.3 x 10 11 cm -3 . A maximum in the negative ion density as a function of induction coil power was observed. The maximum is attributed to a power dependent change in the density of one or more of the potential negative ion precursor species since the electron temperature did not depend strongly on power. The variation of photodetachment with laser wavelength indicated that the dominant negative ion was F - . Measurement of the decay of the negative ion density in the afterglow of a pulse modulated discharge was used to determine the ion-ion recombination rate for CF 4 , C 2 F 6 and CHF 3 discharges

Electron temperatures of inductively coupled Cl2-Ar plasmas

International Nuclear Information System (INIS)

Fuller, N.C.M.; Donnelly, Vincent M.; Herman, Irving P.

2002-01-01

Trace rare gases optical emission spectroscopy has been used to measure the electron temperature, T e , in a high-density inductively coupled Cl 2 -Ar plasma at 18 mTorr as function of the 13.56 MHz radio frequency power and Ar fraction. Only the Kr and Xe emission lines were used to determine T e , because of evidence of radiation trapping when the Ar emission lines were also used for larger Ar fractions. At 600 W (10.6 W cm-2), T e increases from ∼4.0±0.5 eV to ∼6.0±2.0 eV as the Ar fraction increases from 1% to 96%. In the H (inductive, bright) mode, T e , for a 'neat' chlorine plasma (including 1% of each He/Ne/Ar/Kr/Xe) increases only slightly from ∼3.8 to 4.0 eV as power increases from 450 to 750 W. This increase is much larger for larger Ar fractions, such as from ∼4.0 to 7.3 eV for 78% Ar. Most of these effects can be understood using the fundamental particle balance equation

The Haptoglobin-CD163-Heme Oxygenase-1 Pathway for Hemoglobin Scavenging

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Jens Haugbølle Thomsen

2013-01-01

Full Text Available The haptoglobin- (Hp- CD163-heme oxygenase-1 (HO-1 pathway is an efficient captor-receptor-enzyme system to circumvent the hemoglobin (Hb/heme-induced toxicity during physiological and pathological hemolyses. In this pathway, Hb tightly binds to Hp leading to CD163-mediated uptake of the complex in macrophages followed by lysosomal Hp-Hb breakdown and HO-1-catalyzed conversion of heme into the metabolites carbon monoxide (CO, biliverdin, and iron. The plasma concentration of Hp is a limiting factor as evident during accelerated hemolysis, where the Hp depletion may cause serious Hb-induced toxicity and put pressure on backup protecting systems such as the hemopexin-CD91-HO pathway. The Hp-CD163-HO-1 pathway proteins are regulated by the acute phase mediator interleukin-6 (IL-6, but other regulatory factors indicate that this upregulation is a counteracting anti-inflammatory response during inflammation. The heme metabolites including bilirubin converted from biliverdin have overall an anti-inflammatory effect and thus reinforce the anti-inflammatory efficacy of the Hp-CD163-HO-1 pathway. Future studies of animal models of inflammation should further define the importance of the pathway in the anti-inflammatory response.

Lycopene inhibits NF-κB activation and adhesion molecule expression through Nrf2-mediated heme oxygenase-1 in endothelial cells.

Science.gov (United States)

Yang, Po-Min; Chen, Huang-Zhi; Huang, Yu-Ting; Hsieh, Chia-Wen; Wung, Being-Sun

2017-06-01

The endothelial expression of cell adhesion molecules plays a leading role in atherosclerosis. Lycopene, a carotenoid with 11 conjugated double bonds, has been shown to have anti-inflammatory properties. In the present study, we demonstrate a putative mechanism for the anti-inflammatory effects of lycopene. We demonstrate that lycopene inhibits the adhesion of tumor necrosis factor α (TNFα)-stimulated monocytes to endothelial cells and suppresses the expression of intercellular cell adhesion molecule-1 (ICAM-1) at the transcriptional level. Moreover, lycopene was found to exert its inhibitory effects by blocking the degradation of the inhibitory protein, IκBα, following 6 h of pre-treatment. In TNFα-stimulated endothelial cells, nuclear factor-κB (NF-κB) nuclear translocation and transcriptional activity were abolished by up to 12 h of lycopene pre-treatment. We also found that lycopene increased the intracellular glutathione (GSH) level and glutamate-cysteine ligase expression. Subsequently, lycopene induced nuclear factor-erythroid 2 related factor 2 (Nrf2) activation, leading to the increased expression of downstream of heme oxygenase-1 (HO-1). The use of siRNA targeting HO-1 blocked the inhibitory effects of lycopene on IκB degradation and ICAM-1 expression. The inhibitory effects of lycopene thus appear to be mediated through its induction of Nrf2-mediated HO-1 expression. Therefore, the findings of the present study indicate that lycopene suppresses the activation of TNFα-induced signaling pathways through the upregulation of Nrf2-mediated HO-1 expression.

Critical role of heme oxygenase-1 in Foxp3-mediated immune suppression

International Nuclear Information System (INIS)

Choi, Byung-Min; Pae, Hyun-Ock; Jeong, Young-Ran; Kim, Young-Myeong; Chung, Hun-Taeg

2005-01-01

Foxp3, which encodes the transcription factor scurfin, is indispensable for the development and function of CD4 + CD25 + regulatory T cells (Treg). Recent data suggest conversion of peripheral CD4 + CD25 - naive T cells to CD4 + CD25 + Treg by acquisition of Foxp3 through costimulation with TCR and TGF-β or forced expression of the gene. One critical question is how Foxp3 causes T cells to become regulatory. In the present work, we demonstrate that Foxp3 can induce heme oxygenase-1 (HO-1) expression and subsequently such regulatory phenotypes as the suppression of nontransfected cells in a cell-cell contact-dependent manner as well as impaired proliferation and production of cytokines upon stimulation in Jurkat T cells. Moreover, we confirm the expression of both Foxp3 and HO-1 in peripheral CD4 + CD25 + Treg and suppressive function of the cells are relieved by the inhibition of HO-1 activity. In summary, we demonstrate that Foxp3 induces HO-1 expression and HO-1 engages in Foxp3-mediated immune suppression

Host heme oxygenase-1: Friend or foe in tackling pathogens?

Science.gov (United States)

Singh, Nisha; Ahmad, Zeeshan; Baid, Navin; Kumar, Ashwani

2018-05-14

Infectious diseases are a major challenge in management of human health worldwide. Recent literature suggests that host immune system could be modulated to ameliorate the pathogenesis of infectious disease. Heme oxygenase (HMOX1) is a key regulator of cellular signaling and it could be modulated using pharmacological reagents. HMOX1 is a cytoprotective enzyme that degrades heme to generate carbon monoxide (CO), biliverdin, and molecular iron. CO and biliverdin (or bilirubin derived from it) can restrict the growth of a few pathogens. Both of these also induce antioxidant pathways and anti-inflammatory pathways. On the other hand, molecular iron can induce proinflammatory pathway besides making the cellular environment oxidative in nature. Since microbial infections often induce oxidative stress in host cells/tissues, role of HMOX1 has been analyzed in the pathogenesis of number of infections. In this review, we have described the role of HMOX1 in pathogenesis of bacterial infections caused by Mycobacterium species, Salmonella and in microbial sepsis. We have also provided a succinct overview of the role of HMOX1 in parasitic infections such as malaria and leishmaniasis. In the end, we have also elaborated the role of HMOX1 in viral infections such as AIDS, hepatitis, dengue, and influenza. © 2018 IUBMB Life, 2018. © 2018 International Union of Biochemistry and Molecular Biology.

Induction-linac based free-electron laser amplifiers for plasma heating

International Nuclear Information System (INIS)

Jong, R.A.

1988-01-01

We describe an induction-linac based free-electron laser amplifier that is presently under construction at the Lawrence Livermore National Laboratory. It is designed to produce up to 2 MW of average power at a frequency of 250 GHz for plasma heating experiments in the Microwave Tokamak Experiment. In addition, we shall describe a FEL amplifier design for plasma heating of advanced tokamak fusion devices. This system is designed to produce average power levels of about 10 MW at frequencies ranging form 280 to 560 GHz. 7 refs., 1 tab

Hyperglycemia in Streptozotocin-Induced Diabetes Leads to Persistent Inflammation and Tissue Damage Following Uveitis Due to Reduced Levels of Ciliary Body Heme Oxygenase-1

Directory of Open Access Journals (Sweden)

2006-01-01

Full Text Available This study investigated the heme oxygenase-1 (HO-1 and the endotoxin-induced uveitis (EIU in diabetic streptozotocin (STZ-hyperglycemic rats. STZ-hyperglycemic rats had impaired levels of the enzyme HO-1 within the ciliary bodies if compared with the nondiabetic rats. STZ-hyperglycemic rats also predisposed the eye to produce high levels of both the cytokines IL-1 β and CXCL8. Subsequent EIU further and significantly P<.01 increased the cytokines production, an effect partly prevented by hemin treatment. Most importantly, hemin, an inducer of heme oxygenase expression and activity, recovered the huge number of infiltrated polymorphonuclear leukocytes PMN within the ciliary bodies associated with STZ-hyperglycemic state and EIU damage. Impairment of the stress-sensitive enzyme HO-1 in STZ-hyperglycemic rats increases and prolongs the inflammatory response to EIU.

Induction linacs

International Nuclear Information System (INIS)

Keefe, D.

1986-07-01

The principle of linear induction acceleration is described, and examples are given of practical configurations for induction linacs. These examples include the Advanced Technology Accelerator, Long Pulse Induction Linac, Radial Line Accelerator (RADLAC), and Magnetically-Insulated Electron-Focussed Ion Linac. A related concept, the auto accelerator, is described in which the high-current electron-beam technology in the sub-10 MeV region is exploited to produce electron beams at energies perhaps as high as the 100 to 1000 MeV range. Induction linacs for ions are also discussed. The efficiency of induction linear acceleration is analyzed

Semipermeable membrane devices concentrate mixed function oxygenase inducers from oil sands and refinery wastewaters

International Nuclear Information System (INIS)

Parrott, J.L.; Hewitt, L.M.

2002-01-01

The health of fish in the Athabasca River was examined to determine the effects of both natural and anthropogenic oil sands exposure on liver mixed function oxygenase (MFO) enzymes. Semipermeable membrane devices (SPMD) were used to concentrate bioavailable compounds that may result in MFO induction. The SPMDs were used for a period of 2 weeks in the Steepbank River as well as in oil refinery wastewater and intake ponds. They were then tested to see if they induced ethoxyresorufin-O-deethylase (EROD) activity in hepatoma cells, a cell line derived from a liver cancer of a small fish. SPMDs from the wastewater pond contained potent EROD inducers in fish liver cells. SPMDs from the Athabasca River exhibited some EROD inducers, but they were 1/100 as potent as those of the refinery wastewater. The characteristics of MFO inducers from refinery wastewater were different from natural inducers from the oil sands in the Athabasca and Steepbank Rivers. For instance, log Kow was less than 5 for refinery wastewater, but it was greater than 5 for Athabasca River wastewater and from natural oil sands exposure. In the case of the Steepbank River, the pattern of MFO induction was similar to the MFO induction seen in wild fish.The highest MFO inducers were found to be in the area of the mine, suggesting and anthropogenic pollution source. The less potent inducers were in the area of the natural and undisturbed oil sands. Very few inducers were found outside of the oil sands formation

Celastrol ameliorates HIV-1 Tat-induced inflammatory responses via NF-kappaB and AP-1 inhibition and heme oxygenase-1 induction in astrocytes

International Nuclear Information System (INIS)

Youn, Gi Soo; Kwon, Dong-Joo; Ju, Sung Mi; Rhim, Hyangshuk; Bae, Yong Soo; Choi, Soo Young; Park, Jinseu

2014-01-01

HIV-1 Tat causes extensive neuroinflammation that may progress to AIDS-related encephalitis and dementia. Celastrol possesses various biological activities such as anti-oxidant, anti-tumor, and anti-inflammatory activities. In this study, we investigated the modulatory effects of celastrol on HIV-1 Tat-induced inflammatory responses and the molecular mechanisms underlying its action in astrocytes. Pre-treatment of CRT-MG human astroglioma cells with celastrol significantly inhibited HIV-1 Tat-induced expression of ICAM-1/VCAM-1 and subsequent monocyte adhesiveness in CRT-MG cells. In addition, celastrol suppressed HIV-1 Tat-induced expression of pro-inflammatory chemokines, such as CXCL10, IL-8, and MCP-1. Celastrol decreased HIV-1 Tat-induced activation of JNK MAPK, AP-1, and NF-κB. Furthermore, celastrol induced mRNA and protein expression of HO-1 as well as Nrf2 activation. Blockage of HO-1 expression using siRNA reversed the inhibitory effect of celastrol on HIV-1 Tat-induced inflammatory responses. These results suggest that celastrol has regulatory effects on HIV-1 Tat-induced inflammatory responses by blocking the JNK MAPK-AP-1/NF-κB signaling pathways and inducing HO-1 expression in astrocytes. - Highlights: • Celastrol suppressed HIV-1 Tat-induced expression of pro-inflammatory genes. • Celastrol inhibited HIV-1 Tat -induced activation of JNK MAPK. • Celastrol inhibited HIV-1 Tat-induced activation of both NF-κB and AP-1. • Celastrol inhibited HIV-1 Tat-induced inflammatory responses via HO-1 induction

Celastrol ameliorates HIV-1 Tat-induced inflammatory responses via NF-kappaB and AP-1 inhibition and heme oxygenase-1 induction in astrocytes

Energy Technology Data Exchange (ETDEWEB)

Youn, Gi Soo; Kwon, Dong-Joo; Ju, Sung Mi [Department of Biomedical Science and Research Institute for Bioscience and Biotechnology, Hallym University, Chunchon 200-702 (Korea, Republic of); Rhim, Hyangshuk [Department of Biomedical Sciences, Department of Medical Life Sciences, College of Medicine, the Catholic University of Korea, Seoul 137-701 (Korea, Republic of); Bae, Yong Soo [Department of Biological Science, College of Natural Sciences, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Choi, Soo Young [Department of Biomedical Science and Research Institute for Bioscience and Biotechnology, Hallym University, Chunchon 200-702 (Korea, Republic of); Park, Jinseu, E-mail: jinpark@hallym.ac.kr [Department of Biomedical Science and Research Institute for Bioscience and Biotechnology, Hallym University, Chunchon 200-702 (Korea, Republic of)

2014-10-01

HIV-1 Tat causes extensive neuroinflammation that may progress to AIDS-related encephalitis and dementia. Celastrol possesses various biological activities such as anti-oxidant, anti-tumor, and anti-inflammatory activities. In this study, we investigated the modulatory effects of celastrol on HIV-1 Tat-induced inflammatory responses and the molecular mechanisms underlying its action in astrocytes. Pre-treatment of CRT-MG human astroglioma cells with celastrol significantly inhibited HIV-1 Tat-induced expression of ICAM-1/VCAM-1 and subsequent monocyte adhesiveness in CRT-MG cells. In addition, celastrol suppressed HIV-1 Tat-induced expression of pro-inflammatory chemokines, such as CXCL10, IL-8, and MCP-1. Celastrol decreased HIV-1 Tat-induced activation of JNK MAPK, AP-1, and NF-κB. Furthermore, celastrol induced mRNA and protein expression of HO-1 as well as Nrf2 activation. Blockage of HO-1 expression using siRNA reversed the inhibitory effect of celastrol on HIV-1 Tat-induced inflammatory responses. These results suggest that celastrol has regulatory effects on HIV-1 Tat-induced inflammatory responses by blocking the JNK MAPK-AP-1/NF-κB signaling pathways and inducing HO-1 expression in astrocytes. - Highlights: • Celastrol suppressed HIV-1 Tat-induced expression of pro-inflammatory genes. • Celastrol inhibited HIV-1 Tat -induced activation of JNK MAPK. • Celastrol inhibited HIV-1 Tat-induced activation of both NF-κB and AP-1. • Celastrol inhibited HIV-1 Tat-induced inflammatory responses via HO-1 induction.

Physalis peruviana L. inhibits airway inflammation induced by cigarette smoke and lipopolysaccharide through inhibition of extracellular signal-regulated kinase and induction of heme oxygenase-1.

Science.gov (United States)

Park, Hyun Ah; Lee, Jae-Won; Kwon, Ok-Kyoung; Lee, Gilhye; Lim, Yourim; Kim, Jung Hee; Paik, Jin-Hyub; Choi, Sangho; Paryanto, Imam; Yuniato, Prasetyawan; Kim, Doo-Young; Ryu, Hyung Won; Oh, Sei-Ryang; Lee, Seung Jin; Ahn, Kyung-Seop

2017-11-01

Physalis peruviana L. (PP) is a medicinal herb that has been confirmed to have several biological activities, including anticancer, antioxidant and anti-inflammatory properties. The aim of the present study was to evaluate the protective effect of PP on cigarette smoke (CS)- and lipopolysaccharide (LPS)-induced pulmonary inflammation. Treatment with PP significantly reduced the influx of inflammatory cells in the bronchoalveolar lavage fluid (BALF) and lung of mice with CS- and LPS-induced pulmonary inflammation. PP also decreased the levels of reactive oxygen species (ROS) and pro-inflammatory cytokines, such as tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in the BALF. PP effectively attenuated the expression of monocyte chemoattractant protein-1 (MCP-1) and the activation of extracellular signal-regulated kinase (ERK) in the lung. In addition, nuclear factor erythroid 2-related factor 2 (Nrf2) activation and heme oxygenase-1 (HO-1) expression were increased by PP treatment. In an in vitro experiment, PP reduced the mRNA expression of TNF-α and MCP-1, and the activation of ERK in CS extract-stimulated A549 epithelial cells. Furthermore, PP increased the activation of Nrf2 and the expression of HO-1 in A549 cells. These findings suggest that PP has a therapeutic potential for the treatment of pulmonary inflammatory diseases, such as chronic obstructive pulmonary disease.

Identification of heme oxygenase-1 stimulators by a convenient ELISA-based bilirubin quantification assay.

Science.gov (United States)

Rücker, Hannelore; Amslinger, Sabine

2015-01-01

The upregulation of heme oxygenase-1 (HO-1) has proven to be a useful tool for fighting inflammation. In order to identify new HO-1 inducers, an efficient screening method was developed which can provide new lead structures for drug research. We designed a simple ELISA-based HO-1 enzyme activity assay, which allows for the screening of 12 compounds in parallel in the setting of a 96-well plate. The well-established murine macrophage cell line RAW264.7 is used and only about 26µg of protein from whole cell lysates is needed for the analysis of HO-1 activity. The quantification of HO-1 activity is based on an indirect ELISA using the specific anti-bilirubin antibody 24G7 to quantify directly bilirubin in the whole cell lysate, applying a horseradish peroxidase-tagged antibody together with ortho-phenylenediamine and H2O2 for detection. The bilirubin is produced on the action of HO enzymes by converting their substrate heme to biliverdin and additional recombinant biliverdin reductase together with NADPH at pH 7.4 in buffer. This sensitive assay allows for the detection of 0.57-82pmol bilirubin per sample in whole cell lysates. Twenty-three small molecules, mainly natural products with an α,β-unsaturated carbonyl unit such as polyphenols, including flavonoids and chalcones, terpenes, an isothiocyanate, and the drug oltipraz were tested at typically 6 or 24h incubation with RAW264.7 cells. The activity of known HO-1 inducers was confirmed, while the chalcones cardamonin, flavokawain A, calythropsin, 2',3,4'-trihydroxy-4-methoxychalcone (THMC), and 2',4'-dihydroxy-3,4-dimethoxychalcone (DHDMC) were identified as new potent HO-1 inducers. The highest inductive power after 6h incubation was found at 10µM for DHDMC (6.1-fold), carnosol (3.9-fold), butein (3.1-fold), THMC (2.9-fold), and zerumbone (2.5-fold). Moreover, the time dependence of HO-1 protein production for DHDMC was compared to its enzyme activity, which was further evaluated in the presence of

Effect of cellular glutathione content on the induction of DNA double strand breaks by 25 MeV electrons

Energy Technology Data Exchange (ETDEWEB)

Frankenberg, D.; Kistler, M.; Eckhardt-Schupp, F.

1987-08-01

The effect of endogenous glutathione (GSH) on the induction of DNA double strand breaks (dsb) by 25 MeV electrons was investigated using stationary haploid yeast cells defective in ..gamma..-glutamyl-cysteine-synthetase (gsh 1) containing less than 5 per cent of the normal GSH content. In gsh 1 cells the induction of dsb is increased by a factor of 1.5 under oxic and 1.8 under anoxic irradiation conditions whereas the oxygen enhancement ratio was only slightly decreased (1.9) compared to wild-type cells (2.4).

Effect of cellular glutathione content on the induction of DNA double strand breaks by 25 MeV electrons

International Nuclear Information System (INIS)

Frankenberg, D.; Kistler, M.; Eckhardt-Schupp, F.

1987-01-01

The effect of endogenous glutathione (GSH) on the induction of DNA double strand breaks (dsb) by 25 MeV electrons was investigated using stationary haploid yeast cells defective in γ-glutamyl-cysteine-synthetase (gsh 1) containing less than 5 per cent of the normal GSH content. In gsh 1 cells the induction of dsb is increased by a factor of 1.5 under oxic and 1.8 under anoxic irradiation conditions whereas the oxygen enhancement ratio was only slightly decreased (1.9) compared to wild-type cells (2.4). (author)

Regulation of heme oxygenase-1 expression and MAPK pathways in response to kaempferol and rhamnocitrin in PC12 cells

International Nuclear Information System (INIS)

Hong, J.-T.; Yen, J.-H.; Wang Lisu; Lo, Y.-H.; Chen, Z.-T.; Wu, M.-J.

2009-01-01

Oxidative stress has been considered as a major cause of cellular injuries in a variety of clinical abnormalities, especially neural diseases. Our aim of research is to investigate the protective effects and mechanisms of kaempferol and rhamnocitrin (kaempferol-7-methyl ether) on oxidative damage in rat pheochromocytoma PC12 cells induced by a limited supply of serum and hydrogen peroxide (H 2 O 2 ). The current result demonstrated that kaempferol protected PC12 cells from serum deprivation-induced apoptosis. Pretreatment of cells with kaempferol also diminished intracellular generation of reactive oxygen species (ROS) in response to H 2 O 2 and strongly elevated cell viability. RT-Q-PCR and Western blotting revealed that kaempferol and rhamnocitrin significantly induced heme oxygenase (HO)-1 gene expression. Addition of zinc protoporphyrin (Znpp), a HO-1 competitive inhibitor, significantly attenuated their protective effects in H 2 O 2 -treated cells, indicating the vital role of HO-1 in cell resistance to oxidative injury. While investigating the signaling pathways responsible for HO-1 induction, we observed that kaempferol induced sustained extracellular signal-regulated protein kinase 1/2 (ERK1/2) in PC12 cells grown in low serum medium; while rhamnocitrin only stimulated transient ERK cascade. Addition of U0126, a highly selective inhibitor of MEK1/2, which is upstream of ERK1/2, had no effect on kaempferol- or rhamnocitrin-induced HO-1 mRNA expression, indicating no direct cross-talk between these two pathways. Furthermore, both kaempferol and rhamnocitrin were able to persistently attenuate p38 phosphorylation. Taking together, the above findings suggest that kaempferol and rhamnocitrin can augment cellular antioxidant defense capacity, at least in part, through regulation of HO-1 expression and MAPK signal transduction.

Hemin activation of innate cellular response blocks human immunodeficiency virus type-1-induced osteoclastogenesis

International Nuclear Information System (INIS)

Takeda, Kazuyo; Adhikari, Rewati; Yamada, Kenneth M.; Dhawan, Subhash

2015-01-01

The normal skeletal developmental and homeostatic process termed osteoclastogenesis is exacerbated in numerous pathological conditions and causes excess bone loss. In cancer and HIV-1-infected patients, this disruption of homeostasis results in osteopenia and eventual osteoporesis. Counteracting the factors responsible for these metabolic disorders remains a challenge for preventing or minimizing this co-morbidity associated with these diseases. In this report, we demonstrate that a hemin-induced host protection mechanism not only suppresses HIV-1 associated osteoclastogenesis, but it also exhibits anti-osteoclastogenic activity for non-infected cells. Since the mode of action of hemin is both physiological and pharmacological through induction of heme oxygenase-1 (HO-1), an endogenous host protective response to an FDA-licensed therapeutic used to treat another disease, our study suggests an approach to developing novel, safe and effective therapeutic strategies for treating bone disorders, because hemin administration in humans has previously met required FDA safety standards. - Highlights: • HIV-1 infection induced osteoclastogenesis in primary human macrophages. • Heme oxygenase-1 (HO-1) induction inhibited HIV-1-induced osteoclastogenesis in macrophages. • HO-1 induction suppressed RANKL-enhanced osteoclastogenesis in HIV-1-infected macrophages. • This inverse relationship between HO-1 and HIV-1 pathogenesis may define a novel host defense response against HIV-1 infection

Hemin activation of innate cellular response blocks human immunodeficiency virus type-1-induced osteoclastogenesis

Energy Technology Data Exchange (ETDEWEB)

Takeda, Kazuyo [Microscopy and Imaging Core Facility, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, MD (United States); Adhikari, Rewati [Division of Transfusion Transmitted Diseases, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, MD (United States); Yamada, Kenneth M. [National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD (United States); Dhawan, Subhash, E-mail: subhash.dhawan@fda.hhs.gov [Division of Transfusion Transmitted Diseases, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, MD (United States)

2015-08-14

The normal skeletal developmental and homeostatic process termed osteoclastogenesis is exacerbated in numerous pathological conditions and causes excess bone loss. In cancer and HIV-1-infected patients, this disruption of homeostasis results in osteopenia and eventual osteoporesis. Counteracting the factors responsible for these metabolic disorders remains a challenge for preventing or minimizing this co-morbidity associated with these diseases. In this report, we demonstrate that a hemin-induced host protection mechanism not only suppresses HIV-1 associated osteoclastogenesis, but it also exhibits anti-osteoclastogenic activity for non-infected cells. Since the mode of action of hemin is both physiological and pharmacological through induction of heme oxygenase-1 (HO-1), an endogenous host protective response to an FDA-licensed therapeutic used to treat another disease, our study suggests an approach to developing novel, safe and effective therapeutic strategies for treating bone disorders, because hemin administration in humans has previously met required FDA safety standards. - Highlights: • HIV-1 infection induced osteoclastogenesis in primary human macrophages. • Heme oxygenase-1 (HO-1) induction inhibited HIV-1-induced osteoclastogenesis in macrophages. • HO-1 induction suppressed RANKL-enhanced osteoclastogenesis in HIV-1-infected macrophages. • This inverse relationship between HO-1 and HIV-1 pathogenesis may define a novel host defense response against HIV-1 infection.

Tumor induction and hair follicle damage for different electron penetrations in rat skin

International Nuclear Information System (INIS)

Burns, F.J.; Sinclair, I.P.; Albert, R.E.; Vanderlaan, M.

1976-01-01

The penetration and dose of an electron beam were varied in an attempt to locate the depth in growing-phase rat skin where irradiation was most effective in inducing tumors and morphological damage to the hair follicles. The hair was plucked to initiate the growing phase of the hair cycle, and 12 days later the dorsal skin was irradiated with electrons penetrating 0.5, 1.0, or 2.0 mm at doses from 500 to 4000 rad. Differences in the curves of tumor incidence as a function of dose for different penetrations were best resolved by plotting the results against the 0.4 mm dose, while comparable curves for destruction of the follicles were best resolved by the 0.8 mm dose. Since 0.8 mm corresponded approximately to the depth of the follicles, these results indicated that the target tissues for follicular damage and tumor induction were separated in depth and that the target for tumor induction was probably located in the region above or near the midpoint of the follicles. When the radiation penetrated sufficiently to reach the entire follicle, the number of tumors produced was not significantly greater than the number observed previously in resting-phase skin, and it was inferred that the additional size and greater mitotic activity of the growing-phase follicles at the time of irradiation did not increase the probability of tumor induction

Metallothionein-III protects against 6-hydroxydopamine-induced oxidative stress by increasing expression of heme oxygenase-1 in a PI3K and ERK/Nrf2-dependent manner

International Nuclear Information System (INIS)

Hwang, Yong Pil; Kim, Hyung Gyun; Han, Eun Hee; Jeong, Hye Gwang

2008-01-01

The zinc-binding protein metallothionein-III (MT-III) is associated with resistance to neuronal injury. However, the underlying mechanism for its effects is unclear. In this study, we demonstrate that MT-III prevents the accumulation of reactive oxygen species (ROS) in dopaminergic SH-SY5Y cells challenged with the Parkinson's disease-related neurotoxin 6-hydroxydopamine (6-OHDA) by a mechanism that involves phosphatidylinositol 3-kinase (PI3K) and ERK kinase/NF-E2-related factor 2 (Nrf2) dependent induction of the stress response protein heme oxygenase-1 (HO-1). Pretreatment of SH-SY5Y cells with MT-III significantly reduced 6-OHDA-induced generation of ROS, caspase-3 activation, and subsequent cell death. Also, MT-III up-regulates HO-1 expression and this expression confers neuroprotection against oxidative injury induced by 6-OHDA. Moreover, MT-III induces Nrf2 nuclear translocation, which is upstream of MT-III-induced HO-1 expression, and PI3K and ERK1/2 activation, a pathway that is involved in induced Nrf2 nuclear translocation, HO-1 expression and neuroprotection. Taken together, these results suggest that the PI3K and ERK/Nrf2 signaling pathway controls the intracellular levels of ROS by regulating the expression of the antioxidant enzyme HO-1

Effects of Metalloporphyrins on Heme Oxygenase-1 Transcription: Correlative Cell Culture Assays Guide in Vivo Imaging

Directory of Open Access Journals (Sweden)

Monica Hajdena-Dawson

2003-07-01

Full Text Available Heme oxygenase (HO is the rate-limiting step in the heme degradation pathway and is a potential target for the control, or prevention, of pathologic jaundice in neonates. Metalloporphyrins (Mps, a diverse set of synthetic derivatives of heme, can competitively inhibit the HO enzymes. However, certain Mps are phototoxic and some increase transcription of HO-1, the inducible HO isozyme. Therefore, effective development of this class of compounds as therapeutics for treating pathologic jaundice will require rapid and integrated biological screens to identify the most efficacious and safe Mps. To study the safety of these compounds, we assessed their cytotoxic effects and measured luciferase activity by bioluminescent imaging (BLI as an index of HO-1 transcription, first in live cell cultures and then in living transgenic reporter mice. A total of 12 Mps were first evaluated in the correlative cell culture assay. Based on results from this study, 2 Mps, zinc protoporphyrin (ZnPP and zinc bis glycol porphyrin (ZnBG, were selected for further studies in the live animal model. In vitro BLI showed ZnPP to be a strong inducer of HO-1 transcription in comparison to ZnBG, which showed minimal induction. Cytotoxicity studies revealed that ZnPP was phototoxic, whereas ZnBG had no effect on cell viability. In vivo BLI showed that both ZnPP and ZnBG had minimal effects on the levels of HO-1 transcription in the animals. Furthermore, serum enzyme assays indicated that neither caused detectable liver toxicity. These findings, and especially those with ZnBG, support the use of selected Mps as therapies for pathologic jaundice. Coupling the high throughput advantage of cell culture with the capability of imaging for whole-body temporal analyses could accelerate and refine the preclinical phases of drug development. Thus, this study serves as a model for understanding the effects of specific compounds in relation to defined targets using an integrated approach.

L-myo-inosose-1 as a probable intermediate in the reaction catalyzed by myo-inositol oxygenase

International Nuclear Information System (INIS)

Naber, N.I.; Swan, J.S.; Hamilton, G.A.

1986-01-01

In previous investigations, it was necessary to have Fe(II) and cysteine present in order to assay the catalytic activity of purified hog kidney myo-inositol oxygenase. In the present study it was found that, if this purified nonheme iron enzyme is slowly frozen in solution with glutathione and stored at -20 degrees C, it is fully active in the absence of activators if catalase is present to remove adventitious H 2 O 2 . With this simpler assay system it was possible to clarify the effects of several variables on the enzymic reaction. Thus, the maximum velocity is pH-dependent with a maximum around pH 9.5, but the apparent Km for myo-inositol (air atmosphere) remains constant at 5.0 mM throughout a broad pH range. The enzyme is quite specific for its substrate myo-inositol, is very sensitive to oxidants and reductants, but is not affected by a variety of complexing agents, nucleotides, sulfhydryl reagents, etc. In other experiments it was found that L-myo-inosose-1, a potential intermediate in the enzymic reaction, is a potent competitive inhibitor (Ki = 62 microM), while other inososes and a solution thought to contain D-glucodialdehyde, another potential intermediate, are weak inhibitors. Also, both a kinetic deuterium isotope effect (kH/kD = 2.1) and a tritium isotope effect (kH/kT = 7.5) are observed for the enzymic reaction when [1-2H]- and [1-3H]-myo-inositol are used as reactants. These latter results are considered strong evidence that the oxygenase reaction proceeds by a pathway involving L-myo-inosose-1 as an intermediate rather than by an alternative pathway that would have D-glucodialdehyde as the intermediate

Heme oxygenase-1 dependant pathway contributes to protection by tetramethylpyrazine against chronic hypoxic injury on medulla oblongata in rats.

Science.gov (United States)

Ding, Yan; Hou, Xuefei; Chen, Li; Zhou, Hua; Gong, Yanju; Dai, Liqun; Zheng, Yu

2016-02-15

Tetramethylpyrazine (TMP), one of the active ingredients of the Chinese herb Lingusticum Wallichii (Chuan Xiong) has been proved to protect the medulla oblongata from chronic hypoxia injury. However, the underlying mechanism remains unclear. The purpose of this study was to determine whether the protective effects of TMP are associated with the heme oxygenase-1 (HO-1) dependant pathway in adult rats. The morphological changes of neurons in the hypoglossal nucleus (12N), the nucleus ambiguus (Amb), the nucleus tractus solitarius (NTS), and the pre-Bötzinger complex (pre-BötC) were investigated by Nissl staining; the malondialdehyde (MDA) content and superoxide dismutase (SOD) activity were measured to evaluate the anti-oxidant effect; some apoptosis parameters, Bax mRNA and Bcl-2 mRNA, were tested; and the double immunochemistry staining of active caspase-3/NeuN was performed. Meanwhile, the HO-1 protein expression and heme oxygenase (HO) activity were examined. Tin-protoporphyrin (SnPP), a potent inhibitor of HO, was used to further confirm the effect of HO-1. We found that TMP ameliorated the neuron loss in 12N, Amb and NTS, the decrease in SOD activity and the increase in MDA content, the decrease in Bcl-2 mRNA of medulla oblongata (Pmedulla oblongata in the rats. Copyright © 2015 Elsevier B.V. All rights reserved.

Methane-rich water induces cucumber adventitious rooting through heme oxygenase1/carbon monoxide and Ca(2+) pathways.

Science.gov (United States)

Cui, Weiti; Qi, Fang; Zhang, Yihua; Cao, Hong; Zhang, Jing; Wang, Ren; Shen, Wenbiao

2015-03-01

Methane-rich water triggered adventitious rooting by regulating heme oxygenase1/carbon monoxide and calcium pathways in cucumber explants. Heme oxygenase1/carbon monoxide (HO1/CO) and calcium (Ca(2+)) were reported as the downstream signals in auxin-induced cucumber adventitious root (AR) formation. Here, we observed that application of methane-rich water (MRW; 80% saturation) obviously induced AR formation in IAA-depleted cucumber explants. To address the universality, we checked adventitious rooting in soybean and mung bean explants, and found that MRW (50 and 10% saturation, respectively) exhibited the similar inducing results. To further determine if the HO1/CO system participated in MRW-induced adventitious rooting, MRW, HO1 inducer hemin, its activity inhibitor zinc protoporphyrin IX (ZnPP), and its catalytic by-products CO, bilirubin, and Fe(2+) were used to detect their effects on cucumber adventitious rooting in IAA-depleted explants. Subsequent results showed that MRW-induced adventitious rooting was blocked by ZnPP and further reversed by 20% saturation CO aqueous solution. However, the other two by-products of HO1, bilirubin and Fe(2+), failed to induce AR formation. Above responses were consistent with the MRW-induced increases of HO1 transcript and corresponding protein level. Further molecular evidence indicted that expression of marker genes, including auxin signaling-related genes and cell cycle regulatory genes, were modulated by MRW alone but blocked by the cotreatment with ZnPP, the latter of which could be significantly rescued by the addition of CO. By using the Ca(2+)-channel blocker and Ca(2+) chelator, the involvement of Ca(2+) pathway in MRW-induced adventitious rooting was also suggested. Together, our results indicate that MRW might serve as a stimulator of adventitious rooting, which was partially mediated by HO1/CO and Ca(2+) pathways.

Time-dependent upregulation of electron transport with concomitant induction of regulated excitation dissipation in Haslea diatoms.

Science.gov (United States)

Perkins, R; Williamson, C; Lavaud, J; Mouget, J-L; Campbell, D A

2018-04-16

Photoacclimation by strains of Haslea "blue" diatom species H. ostrearia and H. silbo sp. nov. ined. was investigated with rapid light curves and induction-recovery curves using fast repetition rate fluorescence. Cultures were grown to exponential phase under 50 µmol m -2  s -1 photosynthetic available radiation (PAR) and then exposed to non-sequential rapid light curves where, once electron transport rate (ETR) had reached saturation, light intensity was decreased and then further increased prior to returning to near growth light intensity. The non-sequential rapid light curve revealed that ETR was not proportional to the instantaneously applied light intensity, due to rapid photoacclimation. Changes in the effective absorption cross sections for open PSII reaction centres (σ PSII ') or reaction centre connectivity (ρ) did not account for the observed increases in ETR under extended high light. σ PSII ' in fact decreased as a function of a time-dependent induction of regulated excitation dissipation Y(NPQ), once cells were at or above a PAR coinciding with saturation of ETR. Instead, the observed increases in ETR under extended high light were explained by an increase in the rate of PSII reopening, i.e. Q A - oxidation. This acceleration of electron transport was strictly light dependent and relaxed within seconds after a return to low light or darkness. The time-dependent nature of ETR upregulation and regulated NPQ induction was verified using induction-recovery curves. Our findings show a time-dependent induction of excitation dissipation, in parallel with very rapid photoacclimation of electron transport, which combine to make ETR independent of short-term changes in PAR. This supports a selective advantage for these diatoms when exposed to fluctuating light in their environment.

Interaction of nitric oxide with human heme oxygenase-1.

Science.gov (United States)

Wang, Jinling; Lu, Shen; Moënne-Loccoz, Pierre; Ortiz de Montellano, Paul R

2003-01-24

NO and CO may complement each other as signaling molecules in some physiological situations. We have examined the binding of NO to human heme oxygenase-1 (hHO-1), an enzyme that oxidizes heme to biliverdin, CO, and free iron, to determine whether inhibition of hHO-1 by NO can contribute to the signaling interplay of NO and CO. An Fe(3+)-NO hHO-1-heme complex is formed with NO or the NO donors NOC9 or 2-(N,N-diethylamino)-diazenolate-2-oxide.sodium salt. Resonance Raman spectroscopy shows that ferric hHO-1-heme forms a 6-coordinated, low spin complex with NO. The nu(N-O) vibration of this complex detected by Fourier transform IR is only 4 cm(-1) lower than that of the corresponding metmyoglobin (met-Mb) complex but is broader, suggesting a greater degree of ligand conformational freedom. The Fe(3+)-NO complex of hHO-1 is much more stable than that of met-Mb. Stopped-flow studies indicate that k(on) for formation of the hHO-1-heme Fe(3+)-NO complex is approximately 50-times faster, and k(off) 10 times slower, than for met-Mb, resulting in K(d) = 1.4 microm for NO. NO thus binds 500-fold more tightly to ferric hHO-1-heme than to met-Mb. The hHO-1 mutations E29A, G139A, D140A, S142A, G143A, G143F, and K179A/R183A do not significantly diminish the tight binding of NO, indicating that NO binding is not highly sensitive to mutations of residues that normally stabilize the distal water ligand. As expected from the K(d) value, the enzyme is reversibly inhibited upon exposure to pathologically, and possibly physiologically, relevant concentrations of NO. Inhibition of hHO-1 by NO may contribute to the pleiotropic responses to NO and CO.

Effect of antenna size on electron kinetics in inductively coupled plasmas

Energy Technology Data Exchange (ETDEWEB)

Lee, Hyo-Chang; Chung, Chin-Wook [Department of Electrical Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of)

2013-10-15

Spatially resolved measurements of electron energy distribution functions (EEDFs) are investigated in inductively coupled plasmas with two planar antenna coils. When the plasma is sustained by the antenna with a diameter of 18 cm, the nonlocal kinetics is preserved in the argon gas pressure range from 2 mTorr to 20 mTorr. However, electron kinetics transit from nonlocal kinetics to local kinetics in discharge sustained by the antenna coil with diameter 34 cm. The results suggest that antenna size as well as chamber length are important parameters for the transition of the electron kinetics. Spatial variations of plasma potential, effective electron temperature, and EEDF in terms of total electron energy scale are also presented.

A Lactobacillus rhamnosus strain induces a heme oxygenase dependent increase in Foxp3+ regulatory T cells.

Directory of Open Access Journals (Sweden)

Khalil Karimi

Full Text Available We investigated the consequences of feeding with a Lactobacillus species on the immune environment in GALT, and the role of dendritic cells and heme oxygenase-1 in mediating these responses. Feeding with a specific strain of Lactobacillus rhamnosus induced a significant increase in CD4+CD25+Foxp3+ functional regulatory T cells in GALT. This increase was greatest in the mesenteric lymph nodes and associated with a marked decrease in TNF and IFNγ production. Dendritic cell regulatory function and HO-1 expression was also increased. The increase in Foxp3+ T cells could be prevented by treatment with a heme oxygenase inhibitor. However, neither inhibition of heme oxygenase nor blockade of IL-10 and TGFβ prevented the inhibition of inflammatory cytokine production. In conclusion Lactobacillus feeding induced a tolerogenic environment in GALT. HO-1 was critical to the enhancement of Foxp3+ regulatory T cells while additional, as yet unknown, pathways were involved in the down-regulation of inflammatory cytokine production by T cells.

Heme oxygenase-1 (HO-1) inhibits postmyocardial infarct remodeling and restores ventricular function.

Science.gov (United States)

Liu, Xiaoli; Pachori, Alok S; Ward, Christopher A; Davis, J Paul; Gnecchi, Massimiliano; Kong, Deling; Zhang, Lunan; Murduck, Jared; Yet, Shaw-Fang; Perrella, Mark A; Pratt, Richard E; Dzau, Victor J; Melo, Luis G

2006-02-01

We reported previously that predelivery of the anti-oxidant gene heme oxygenase-1 (HO-1) to the heart by adeno associated virus (AAV) markedly reduces injury after acute myocardial infarction (MI). However, the effect of HO-1 gene delivery on postinfarction recovery has not been investigated. In the current study, we assessed the effect of HO-1 gene delivery on post-MI left ventricle (LV) remodeling and function using echocardiographic imaging and histomorphometric approaches. Two groups of Sprague-Dawley rats were injected with 4 x 10(11) particles of AAV-LacZ (control) or AAV-hHO-1 in the LV wall. Eight wk after gene transfer, the animals were subjected to 30 min of ischemia by ligation of left anterior descending artery (LAD) followed by reperfusion. Echocardiographic measurements were obtained in a blinded fashion prior and at 1.5 and 3 months after I/R. Ejection fraction (EF) was reduced by 13% and 40% in the HO-1 and LacZ groups, respectively at 1.5 months after MI. Three months after MI, EF recovered fully in the HO-1, but only partially in the LacZ-treated animals. Post-MI LV dimensions were markedly increased and the anterior wall was markedly thinned in the LacZ-treated animals compared with the HO-1-treated animals. Significant myocardial scarring and fibrosis were observed in the LacZ-group in association with elevated levels of interstitial collagen I and III and MMP-2 activity. Post-MI myofibroblast accumulation was reduced in the HO-1-treated animals, and retroviral overexpression of HO-1 reduced proliferation of isolated cardiac fibroblasts. Our data indicate that rAAV-HO-1 gene transfer markedly reduces fibrosis and ventricular remodeling and restores LV function and chamber dimensions after myocardial infarction.

Genetic analyses of heme oxygenase 1 (HMOX1 in different forms of pancreatitis.

Directory of Open Access Journals (Sweden)

Sebastian Weis

Full Text Available Heme oxygenase 1 (HMOX1 is the rate limiting enzyme in heme degradation and a key regulator of inflammatory processes. In animal models the course of pancreatitis was ameliorated by up-regulation of HMOX1 expression. Additionally, carbon monoxide released during heme breakdown inhibited proliferation of pancreatic stellate cells and might thereby prevent the development of chronic pancreatitis (CP. Transcription of HMOX1 in humans is influenced by a GT-repeat located in the promoter. As such, HMOX1 variants might be of importance in the pathogenesis of pancreatitis.The GT-repeat and SNP rs2071746 were investigated with fluorescence labelled primers and by melting curve analysis in 285 patients with acute pancreatitis, 208 patients with alcoholic CP, 207 patients with idiopathic/hereditary CP, 147 patients with alcoholic liver cirrhosis, and in 289 controls, respectively. GT-repeat analysis was extended to a total of 446 alcoholic CP patients. In addition, we performed DNA sequencing in 145 patients with alcoholic CP, 138 patients with idiopathic/hereditary CP, 147 patients with alcoholic liver cirrhosis, and 151 controls. Exon 3 screening was extended to additional patients and controls.S- and L-alleles of the GT-repeat, genotypes and alleles of SNP rs2071746 and non-synonymous variants detected by sequencing were found with similar frequencies in all groups.Although functional data implicate a potential influence of HMOX1 variants on the pathogenesis of pancreatitis, we did not find any association. As rare non-synonymous HMOX1 variants were found in patients and controls, it is rather unlikely that they will have functional consequences essential for pancreatitis development.

Glomerular Epithelial Cells-Targeted Heme Oxygenase-1 Over Expression in the Rat: Attenuation of Proteinuria in Secondary But Not Primary Injury.

Science.gov (United States)

Atsaves, Vassilios; Makri, Panagiota; Detsika, Maria G; Tsirogianni, Alexandra; Lianos, Elias A

2016-01-01

Induction of heme oxygenase 1 (HO-1) in glomerular epithelial cells (GEC) in response to injury is poor and this may be a disadvantage. We, therefore, explored whether HO-1 overexpression in GEC can reduce proteinuria induced by puromycin aminonucleoside (PAN) or in anti-glomerular basement membrane (GBM) antibody (Ab)-mediated glomerulonephritis (GN). HO-1 overexpression in GEC (GECHO-1) of Sprague-Dawley rats was achieved by targeting a FLAG-human (h) HO-1 using transposon-mediated transgenesis. Direct GEC injury was induced by a single injection of PAN. GN was induced by administration of an anti-rat GBM Ab and macrophage infiltration in glomeruli was assessed by immunohistochemistry and western blot analysis, which was also used to assess glomerular nephrin expression. In GECHO-1 rats, FLAG-hHO-1 transprotein was co-immunolocalized with nephrin. Baseline glomerular HO-1 protein levels were higher in GECHO-1 compared to wild type (WT) rats. Administration of either PAN or anti-GBM Ab to WT rats increased glomerular HO-1 levels. Nephrin expression markedly decreased in glomeruli of WT or GECHO-1 rats treated with PAN. In anti-GBM Ab-treated WT rats, nephrin expression also decreased. In contrast, it was preserved in anti-GBM Ab-treated GECHO-1 rats. In these, macrophage infiltration in glomeruli and the ratio of urine albumin to urine creatinine (Ualb/Ucreat) were markedly reduced. There was no difference in Ualb/Ucreat between WT and GECHO-1 rats treated with PAN. Depending on the type of injury, HO-1 overexpression in GEC may or may not reduce proteinuria. Reduced macrophage infiltration and preservation of nephrin expression are putative mechanisms underlying the protective effect of HO-1 overexpression following immune injury. © 2016 S. Karger AG, Basel.

Role of brain cytochrome P450 mono-oxygenases in bilirubin oxidation-specific induction and activity.

Science.gov (United States)

Gambaro, Sabrina E; Robert, Maria C; Tiribelli, Claudio; Gazzin, Silvia

2016-02-01

In the Crigler-Najjar type I syndrome, the genetic absence of efficient hepatic glucuronidation of unconjugated bilirubin (UCB) by the uridine 5'-diphospho-glucuronosyltransferase1A1 (UGT1A1) enzyme produces the rise of UCB level in blood. Its entry to central nervous system could generate toxicity and neurological damage, and even death. In the past years, a compensatory mechanism to liver glucuronidation has been indicated in the hepatic cytochromes P450 enzymes (Cyps) which are able to oxidize bilirubin. Cyps are expressed also in the central nervous system, the target of bilirubin toxicity, thus making them theoretically important to confer a protective activity toward bilirubin accumulation and neurotoxicity. We therefore investigated the functional induction (mRNA, EROD/MROD) and the ability to oxidize bilirubin of Cyp1A1, 1A2, and 2A3 in primary astrocytes cultures obtained from two rat brain region (cortex: Cx and cerebellum: Cll). We observed that Cyp1A1 was the Cyp isoform more easily induced by beta-naphtoflavone (βNF) in both Cx and Cll astrocytes, but oxidized bilirubin only after uncoupling by 3, 4,3',4'-tetrachlorobiphenyl (TCB). On the contrary, Cyp1A2 was the most active Cyp in bilirubin clearance without uncoupling, but its induction was confined only in Cx cells. Brain Cyp2A3 was not inducible. In conclusion, the exposure of astrocytes to βNF plus TCB significantly enhanced Cyp1A1 mediating bilirubin clearance, improving cell viability in both regions. These results may be a relevant groundwork for the manipulation of brain Cyps as a therapeutic approach in reducing bilirubin-induced neurological damage.

Iterative reconstruction of magnetic induction using Lorentz transmission electron tomography

International Nuclear Information System (INIS)

Phatak, C.; Gürsoy, D.

2015-01-01

Intense ongoing research on complex nanomagnetic structures requires a fundamental understanding of the 3D magnetization and the stray fields around the nano-objects. 3D visualization of such fields offers the best way to achieve this. Lorentz transmission electron microscopy provides a suitable combination of high resolution and ability to quantitatively visualize the magnetization vectors using phase retrieval methods. In this paper, we present a formalism to represent the magnetic phase shift of electrons as a Radon transform of the magnetic induction of the sample. Using this formalism, we then present the application of common tomographic methods particularly the iterative methods, to reconstruct the 3D components of the vector field. We present an analysis of the effect of missing wedge and the limited angular sampling as well as reconstruction of complex 3D magnetization in a nanowire using simulations. - Highlights: • We present a formalism to represent electron-optical magnetic phase shift as a Radon transform of the 3D magnetic induction of the nano-object. • We have analyzed four different tomographic reconstruction methods for vectorial data reconstruction. • Reconstruction methods were tested for varying experimental limitations such as limited tilt range and limited angular sampling. • The analysis showed that Gridrec and SIRT methods performed better with lower errors than other reconstruction methods

The orbital ground state of the azide-substrate complex of human heme oxygenase is an indicator of distal H-bonding: Implications for the enzyme mechanism‡

OpenAIRE

Ogura, Hiroshi; Evans, John P.; Peng, Dungeng; Satterlee, James D.; de Montellano, Paul R. Ortiz; Mar, Gerd N. La

2009-01-01

The active site electronic structure of the azide complex of substrate-bound human heme oxygenase-1, (hHO) has been investigated by 1H NMR spectroscopy to shed light on the orbital/spin ground state as an indicator of the unique distal pocket environment of the enzyme. 2D 1H NMR assignments of the substrate and substrate-contact residue signals reveal a pattern of substrate methyl contact shifts, that places the lone iron π-spin in the dxz orbital, rather than the dyz orbital found in the cya...

Electron beam potential measurements on an inductive-store, opening-switch accelerator

International Nuclear Information System (INIS)

Riordan, J.C.; Goyer, J.R.; Kortbawi, D.; Meachum, J.S.; Mendenhall, R.S.; Roth, I.S.

1993-01-01

Direct measurement of the accelerating potential in a relativistic electron beam accelerator is difficult, particularly when the diode is downstream from a plasma opening switch. An indirect potential measurement can be obtained from the high energy tail of the bremsstrahlung spectrum generated as the electron beam strikes the anode. The authors' time-resolved spectrometer contains 7 silicon pin diode detectors filtered with 2 to 15 mm of lead to span an electron energy range of 0.5 to 2 MeV. A Monte-Carlo transport code was used to provide calibration curves, and the resulting potential measurements have been confirmed in experiments on the PITHON accelerator. The spectrometer has recently been deployed on PM1, an inductive-store, opening-switch testbed. The diode voltage measurements from the spectrometer are in good agreement with the diode voltage measured upstream and corrected using transmission line relations. The x-ray signal and spectral voltage rise 10 ns later than the corrected electrical voltage, however, indicating plasma motion between the opening switch and the diode

Reduction of bilirubin by targeting human heme oxygenase-1 through siRNA.

Science.gov (United States)

Xia, Zhen-Wei; Li, Chun-E; Jin, You-Xin; Shi, Yi; Xu, Li-Qing; Zhong, Wen-Wei; Li, Yun-Zhu; Yu, Shan-Chang; Zhang, Zi-Li

2007-04-01

Neonatal hyperbilirubinemia is a common clinical condition caused mainly by the increased production and decreased excretion of bilirubin. Current treatment is aimed at reducing the serum levels of bilirubin. Heme oxygenase-1 (HO-1) is a rate-limiting enzyme that generates bilirubin. In this study we intended to suppress HO-1 using the RNA interference technique. Small interfering RNA (siRNA)-A, -B, and -C were designed based on human HO-1 (hHO-1) mRNA sequences. siRNA was transfected into a human hepatic cell line (HL-7702). hHO-1 transcription and protein levels were then determined. In addition, the inhibitory effect of siRNA on hHO-1 was assessed in cells treated with hemin or transfected with an hHO-1 plasmid. siRNA-C showed the most potent suppressive effect on hHO-1. This inhibition is dose and time dependent. Compared with control, both hemin and hHO-1 plasmids up-regulated hHO-1 expression in HL-7702 cells. However, the up-regulation was significantly attenuated by siRNA-C. Furthermore, the decrease in hHO-1 activity was coincident with the suppression of its transcription. Finally, siRNA-C was shown to reduce hHO-1 enzymatic activity and bilirubin levels. Thus, this study provides a novel therapeutic rationale by blocking bilirubin formation via siRNA for preventing and treating neonatal hyperbilirubinemia and bilirubin encephalopathy at an early clinical stage.

The role of heme oxygenase-1 in systemic-onset juvenile idiopathic arthritis.

Science.gov (United States)

Takahashi, Akitaka; Mori, Masaaki; Naruto, Takuya; Nakajima, Shoko; Miyamae, Takako; Imagawa, Tomoyuki; Yokota, Shumpei

2009-01-01

We have determined the serum levels of heme oxygenase-1 (HO-1) in 56 patients with systemic-onset juvenile idiopathic arthritis (s-JIA) and compared these with serum HO-1 levels in healthy controls and patients with other pediatric rheumatic diseases. Serum HO-1 levels were measured by the sandwich enzyme-linked immunosorbent assay. The mean serum HO-1 level in s-JIA patients during the active phase was 123.6 +/- 13.83 ng/ml, which was significantly higher than that in patients with polyarticular juvenile idiopathic arthritis (p-JIA), Kawasaki disease, systemic lupus erythematosus or mixed connective tissue disease (P < 0.0005). The serum levels of HO-1, cytokines and cytokine receptors in patients with s-JIA were also assessed at both the active and inactive phases. The serum HO-1 level in patients with s-JIA in the active phase was found to be significantly greater than that in patients with the disease in the inactive phase (P < 0.0001). An assessment of the relationships between serum HO-1 levels and other laboratory parameters or cytokines in patients with s-JIA did not reveal any strong correlations. These results suggest that the serum level of HO-1 may be a useful marker for the differential diagnosis of s-JIA. Further study will be necessary to elucidate the mechanism of HO-1 production and to clarify the role of HO-1 in the disease process.

A coenzyme-independent decarboxylase/oxygenase cascade for the efficient synthesis of vanillin.

Science.gov (United States)

Furuya, Toshiki; Miura, Misa; Kino, Kuniki

2014-10-13

Vanillin is one of the most widely used flavor compounds in the world as well as a promising versatile building block. The biotechnological production of vanillin from plant-derived ferulic acid has attracted much attention as a new alternative to chemical synthesis. One limitation of the known metabolic pathway to vanillin is its requirement for expensive coenzymes. Here, we developed a novel route to vanillin from ferulic acid that does not require any coenzymes. This artificial pathway consists of a coenzyme-independent decarboxylase and a coenzyme-independent oxygenase. When Escherichia coli cells harboring the decarboxylase/oxygenase cascade were incubated with ferulic acid, the cells efficiently synthesized vanillin (8.0 mM, 1.2 g L(-1) ) via 4-vinylguaiacol in one pot, without the generation of any detectable aromatic by-products. The efficient method described here might be applicable to the synthesis of other high-value chemicals from plant-derived aromatics. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Induction-detection electron spin resonance with spin sensitivity of a few tens of spins

Energy Technology Data Exchange (ETDEWEB)

Artzi, Yaron; Twig, Ygal; Blank, Aharon [Schulich Faculty of Chemistry Technion—Israel Institute of Technology, Haifa 32000 (Israel)

2015-02-23

Electron spin resonance (ESR) is a spectroscopic method that addresses electrons in paramagnetic materials directly through their spin properties. ESR has many applications, ranging from semiconductor characterization to structural biology and even quantum computing. Although it is very powerful and informative, ESR traditionally suffers from low sensitivity, requiring many millions of spins to get a measureable signal with commercial systems using the Faraday induction-detection principle. In view of this disadvantage, significant efforts were made recently to develop alternative detection schemes based, for example, on force, optical, or electrical detection of spins, all of which can reach single electron spin sensitivity. This sensitivity, however, comes at the price of limited applicability and usefulness with regard to real scientific and technological issues facing modern ESR which are currently dealt with conventional induction-detection ESR on a daily basis. Here, we present the most sensitive experimental induction-detection ESR setup and results ever recorded that can detect the signal from just a few tens of spins. They were achieved thanks to the development of an ultra-miniature micrometer-sized microwave resonator that was operated at ∼34 GHz at cryogenic temperatures in conjunction with a unique cryogenically cooled low noise amplifier. The test sample used was isotopically enriched phosphorus-doped silicon, which is of significant relevance to spin-based quantum computing. The sensitivity was experimentally verified with the aid of a unique high-resolution ESR imaging approach. These results represent a paradigm shift with respect to the capabilities and possible applications of induction-detection-based ESR spectroscopy and imaging.

Dry powder inhalation of hemin to induce heme oxygenase expression in the lung

NARCIS (Netherlands)

Zijlstra, G.S.; Brandsma, C.; Harpe, M.F.H.; Van Dam, G.M.; Slebos, D.J.; Kerstjens, H.A.M.; de Boer, Anne; Frijlink, H.W.

2007-01-01

The purpose of this study was to formulate hemin as a powder for inhalation and to show proof of concept of heme oxygenase 1 (HO-1) expression in the lungs of mice by inhalation of hemin. Hemin was spray dried from a neutralized sodium hydroxide solution. The particle size distribution of the powder

Electron beam dynamics in the long-pulse, high-current DARHT-II linear induction accelerator

International Nuclear Information System (INIS)

Ekdahl, Carl A.; Abeyta, Epifanio O.; Aragon, Paul; Archuleta, Rita; Cook, Gerald; Dalmas, Dale; Esquibel, Kevin; Gallegos, Robert A.; Garnett, Robert; Harrison, James F.; Johnson, Jeffrey B.; Jacquez, Edward B.; Mccuistian, Brian T.; Montoya, Nicholas A.; Nath, Subrato; Nielsen, Kurt; Oro, David; Prichard, Benjamin; Rowton, Lawrence; Sanchez, Manolito; Scarpetti, Raymond; Schauer, Martin M.; Seitz, Gerald; Schulze, Martin; Bender, Howard A.; Broste, William B.; Carlson, Carl A.; Frayer, Daniel K.; Johnson, Douglas E.; Tom, C.Y.; Williams, John; Hughes, Thomas; Anaya, Richard; Caporaso, George; Chambers, Frank; Chen, Yu-Jiuan; Falabella, Steve; Guethlein, Gary; Raymond, Brett; Richardson, Roger; Trainham, C.; Watson, Jim; Weir, John; Genoni, Thomas; Toma, Carsten

2009-01-01

The DARHT-II linear induction accelerator (LIA) now accelerates 2-kA electron beams to more than 17 MeV. This LIA is unique in that the accelerated current pulse width is greater than 2 microseconds. This pulse has a flat-top region where the final electron kinetic energy varies by less than 1% for more than 1.5 microseconds. The long risetime of the 6-cell injector current pulse is 0.5 (micro)s, which can be scraped off in a beam-head cleanup zone before entering the 68-cell main accelerator. We discuss our experience with tuning this novel accelerator; and present data for the resulting beam transport and dynamics. We also present beam stability data, and relate these to previous stability experiments at lower current and energy.

Kidneys From α1,3-Galactosyltransferase Knockout/Human Heme Oxygenase-1/Human A20 Transgenic Pigs Are Protected From Rejection During Ex Vivo Perfusion With Human Blood.

Science.gov (United States)

Ahrens, Hellen E; Petersen, Björn; Ramackers, Wolf; Petkov, Stoyan; Herrmann, Doris; Hauschild-Quintern, Janet; Lucas-Hahn, Andrea; Hassel, Petra; Ziegler, Maren; Baars, Wiebke; Bergmann, Sabine; Schwinzer, Reinhard; Winkler, Michael; Niemann, Heiner

2015-07-01

Multiple modifications of the porcine genome are required to prevent rejection after pig-to-primate xenotransplantation. Here, we produced pigs with a knockout of the α1,3-galactosyltransferase gene (GGTA1-KO) combined with transgenic expression of the human anti-apoptotic/anti-inflammatory molecules heme oxygenase-1 and A20, and investigated their xenoprotective properties. The GGTA1-KO/human heme oxygenase-1 (hHO-1)/human A20 (hA20) transgenic pigs were produced in a stepwise approach using zinc finger nuclease vectors targeting the GGTA1 gene and a Sleeping Beauty vector coding for hA20. Two piglets were analyzed by quantitative reverse-transcription polymerase chain reaction, flow cytometry, and sequencing. The biological function of the genetic modifications was tested in a (51)Chromium release assay and by ex vivo kidney perfusions with human blood. Disruption of the GGTA1 gene by deletion of few basepairs was demonstrated in GGTA1-KO/hHO-1/hA20 transgenic pigs. The hHO-1 and hA20 mRNA expression was confirmed by quantitative reverse-transcription polymerase chain reaction. Ex vivo perfusion of 2 transgenic kidneys was feasible for the maximum experimental time of 240 minutes without symptoms of rejection. Results indicate that GGTA1-KO/hHO-1/hA20 transgenic pigs are a promising model to alleviate rejection and ischemia-reperfusion damage in porcine xenografts and could serve as a background for further genetic modifications toward the production of a donor pig that is clinically relevant for xenotransplantation.

Surface Induction Hardening of Axi-Symmetric Bodies

Czech Academy of Sciences Publication Activity Database

Barglik, J.; Doležel, Ivo; Škopek, M.; Ulrych, B.

2001-01-01

Roč. 1, č. 1 (2001), s. 11-16 ISSN 1335-8243 R&D Projects: GA ČR GA102/01/0184 Grant - others:-(PL) 7T08603716 Keywords : induction heating * induction hardening * numerical solution Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

1 MV low-induction pulse generator

International Nuclear Information System (INIS)

Koba, G.I.; Koba, Yu.V.; Slivkov, I.N.; Sukhov, A.D.; Tarumov, Eh.Z.

1980-01-01

A high-voltage pulse generator is described. The generator Uses the Arkadiev-Marx circuit at 1 MV voltage and 12 kJ energy; the inductance of the discharge circuit is 1.3 μN. Low inductance of the generator has been obtained due to the use of low-inductance capacitors and employment of bifilar buses with oil barrier insulation. To provide reliable generator triggering, an ignition circuit has been developed with a resistive coupling between generator steps, based on controlled three-electrode sparkgaps with a distorted field. The generator switching time is slightly dependent on pressure and constitutes 200-300 ns. The generator efficiency is 83%

The Oxygenase CAO-1 of Neurospora crassa Is a Resveratrol Cleavage Enzyme

KAUST Repository

Diaz-Sanchez, V.; F. Estrada, A.; Limon, M. C.; Al-Babili, Salim; Avalos, J.

2013-01-01

The genome of the ascomycete Neurospora crassa encodes CAO-1 and CAO-2, two members of the carotenoid cleavage oxygenase family that target double bonds in different substrates. Previous studies demonstrated the role of CAO-2 in cleaving the C40 carotene torulene, a key step in the synthesis of the C35 apocarotenoid pigment neurosporaxanthin. In this work, we investigated the activity of CAO-1, assuming that it may provide retinal, the chromophore of the NOP-1 rhodopsin, by cleaving β-carotene. For this purpose, we tested CAO-1 activity with carotenoid substrates that were, however, not converted. In contrast and consistent with its sequence similarity to family members that act on stilbenes, CAO-1 cleaved the interphenyl Cα-Cβ double bond of resveratrol and its derivative piceatannol. CAO-1 did not convert five other similar stilbenes, indicating a requirement for a minimal number of unmodified hydroxyl groups in the stilbene background. Confirming its biological function in converting stilbenes, adding resveratrol led to a pronounced increase in cao-1 mRNA levels, while light, a key regulator of carotenoid metabolism, did not alter them. Targeted Δcao-1 mutants were not impaired by the presence of resveratrol, a phytoalexin active against different fungi, which did not significantly affect the growth and development of wild-type Neurospora. However, under partial sorbose toxicity, the Δcao-1 colonies exhibited faster radial growth than control strains in the presence of resveratrol, suggesting a moderate toxic effect of resveratrol cleavage products.

The Oxygenase CAO-1 of Neurospora crassa Is a Resveratrol Cleavage Enzyme

KAUST Repository

Diaz-Sanchez, V.

2013-07-26

The genome of the ascomycete Neurospora crassa encodes CAO-1 and CAO-2, two members of the carotenoid cleavage oxygenase family that target double bonds in different substrates. Previous studies demonstrated the role of CAO-2 in cleaving the C40 carotene torulene, a key step in the synthesis of the C35 apocarotenoid pigment neurosporaxanthin. In this work, we investigated the activity of CAO-1, assuming that it may provide retinal, the chromophore of the NOP-1 rhodopsin, by cleaving β-carotene. For this purpose, we tested CAO-1 activity with carotenoid substrates that were, however, not converted. In contrast and consistent with its sequence similarity to family members that act on stilbenes, CAO-1 cleaved the interphenyl Cα-Cβ double bond of resveratrol and its derivative piceatannol. CAO-1 did not convert five other similar stilbenes, indicating a requirement for a minimal number of unmodified hydroxyl groups in the stilbene background. Confirming its biological function in converting stilbenes, adding resveratrol led to a pronounced increase in cao-1 mRNA levels, while light, a key regulator of carotenoid metabolism, did not alter them. Targeted Δcao-1 mutants were not impaired by the presence of resveratrol, a phytoalexin active against different fungi, which did not significantly affect the growth and development of wild-type Neurospora. However, under partial sorbose toxicity, the Δcao-1 colonies exhibited faster radial growth than control strains in the presence of resveratrol, suggesting a moderate toxic effect of resveratrol cleavage products.

Production of natural fragrance aromatic acids by coexpression of trans-anethole oxygenase and p-anisaldehyde dehydrogenase genes of Pseudomonas putida JYR-1 in Escherichia coli.

Science.gov (United States)

Han, Dongfei; Kurusarttra, Somwang; Ryu, Ji-Young; Kanaly, Robert A; Hur, Hor-Gil

2012-12-05

A gene encoding p-anisaldehyde dehydrogenase (PAADH), which catalyzes the oxidation of p-anisaldehyde to p-anisic acid, was identified to be clustered with the trans-anethole oxygenase (tao) gene in Pseudomonas putida JYR-1. Heterologously expressed PAADH in Escherichia coli catalyzed the oxidation of vanillin, veratraldehyde, and piperonal to the corresponding aromatic acids vanillic acid, veratric acid, and piperonylic acid, respectively. Coexpression of trans-anethole oxygenase (TAO) and PAADH in E. coli also resulted in the successful transformation of trans-anethole, isoeugenol, O-methyl isoeugenol, and isosafrole to p-anisic acid, vanillic acid, veratric acid, and piperonylic acid, respectively, which are compounds found in plants as secondary metabolites. Because of the relaxed substrate specificity and high transformation rates by coexpressed TAO and PAADH in E. coli , the engineered strain has potential to be applied in the fragrance industry.

Identification of a novel oxygenase capable of regiospecific hydroxylation of D-limonene into (+)-trans-carveol

NARCIS (Netherlands)

Groeneveld, M.; van Beek, H. L.; Duetz, W. A.; Fraaije, M. W.

2016-01-01

By genome sequencing and analysis, we have been able to identify a gene cluster encoding a four component oxygenase which is able to oxidize D-limonene, L-limonene, cumene, and indole. Heterologous expression of the complete oxygenase system in Pseudomonas putida S12 allowed efficient and highly

Superconductor Microwave Kinetic Inductance Detectors: System Model of the Readout Electronics

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F. Alimenti

2009-06-01

Full Text Available This paper deals with the readout electronics needed by superconductor Microwave Kinetic Inductance Detectors (MKIDs. MKIDs are typically implemented in the form of cryogenic-cooled high quality factor microwave resonator. The natural frequency of these resonators changes as a millimeter or sub-millimeter wave radiation impinges on the resonator itself. A quantitative system model of the readout electronics (very similar to that of a vector network analyzer has been implemented under ADS environment and tested by several simulation experiments. The developed model is a tool to further optimize the readout electronic and to design the frequency allocation of parallel-connected MKIDs resonators. The applications of MKIDs will be in microwave and millimeter-wave radiometric imaging as well as in radio-astronomy focal plane arrays.

Effects of combined mesenchymal stem cells and heme oxygenase-1 therapy on cardiac performance.

Science.gov (United States)

Zeng, Bin; Chen, Honglei; Zhu, Chengang; Ren, Xiaofeng; Lin, Guosheng; Cao, Feng

2008-10-01

Bone marrow mesenchymal stem cells (MSCs) have the potential to repair the infarcted myocardium and improve cardiac function. However, this approach is limited by its poor viability after transplantation, and controversy still exists over the mechanism by which MSCs contribute to the tissue repair. The human heme oxygenase-1 (hHO-1) was transfected into cultured MSCs using an adenoviral vector. 1 x 10(6) Ad-hHO-1-transfected MSCs (HO-1-MSCs) or Ad-Null-transfected MSCs (Null-MSCs) or PBS only (PBS group) were injected intramyocardially into rat hearts 1h after myocardial infarction. HO-1-MSCs survived in the infarcted myocardium, and expressed hHO-1 mRNA. The expression of basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF) was significantly enhanced in HO-1-MSCs-treated hearts. At the same time, there were significant reduction of TNF-alpha, IL-1-beta and IL-6 mRNA, and marked increase of IL-10 mRNA in HO-1-MSCs-treated hearts. Moreover, a further downregulation of proapoptotic protein, Bax, and a marked increase in microvessel density were observed in HO-1-MSCs-treated hearts. The infarct size and cardiac performance were also significantly improved in HO-1-MSCs-treated hearts. The combined approach improves MSCs survival and is superior to MSCs injection alone.

Hormonal fluctuations during the estrous cycle modulate Heme Oxygenase-1 expression in the uterus

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Maria Laura Zenclussen

2014-03-01

Full Text Available Deletion of the Heme Oxygenase-1 (Hmox1 locus in mice results in intrauterine lethality. The expression of the heme catabolyzing enzyme encoded by this gene, namely HO 1, is required to successfully support reproductive events. We have previously observed that HO-1 acts at several key events in reproduction ensuring pregnancy. HO-1 defines ovulation, positively influences implantation and placentation and ensures fetal growth and survival. Here, we embarked on a study aimed to determine whether hormonal changes during the estrous cycle in the mouse define HO-1 expression, thus influencing receptivity. We analyzed the serum levels of progesterone and estrogen by ELISA and HO-1 mRNA expression in uterus by real time RT-PCR at the metestrus, proestrus, estrus and diestrus phases of the estrous cycle. Further, we studied the HO-1 protein expression by Western Blot upon hormone addition to cultured uterine AN3 cells. We observed that HO-1 variations in uterine tissue correlated to changes in hormonal levels at different phases of the estrus cycle. In vitro, HO-1 protein levels in AN3 cells augmented after the addition of physiological concentrations of progesterone and estradiol, which confirmed our in vivo observations. Our data suggest an important role for hormones in HO-1 regulation in uterus that has a significant impact in receptivity and later on blastocyst implantation.

Adenovirus-mediated heme oxygenase-1 gene transfer into rabbit ocular tissues.

Science.gov (United States)

Abraham, N G; da Silva, J L; Lavrovsky, Y; Stoltz, R A; Kappas, A; Dunn, M W; Schwartzman, M L

1995-10-01

Heme oxygenase-1 (HO-1) is a stress protein induced up to 100-fold within a few hours after exposure to oxidative stress, and it has been shown to counteract oxidative injury induced by ultraviolet light or free radicals. The current study was undertaken to determine whether the HO-1 gene can be introduced into adult rabbit ocular tissues by microinjection of a recombinant replication-deficient adenovirus human HO-1 cDNA (Adv-HHO). Human HO-1 gene was used for transfection studies to differentiate endogenous from transfected HO. The purified Adv-HHO construct (10(8) pfu/ml) was mixed with lipofectamine and microinjected into the anterior chamber, vitreous cavity, and subretinal space of New Zealand rabbit eyes. After 2 weeks, total RNA was extracted from different ocular tissues, reverse transcription-polymerase chain reaction was performed using specific human HO-1 primers, and amplification products were subjected to Southern hybridization. Transfection with the Adv-HHO construct into rabbit corneal epithelial cells in culture resulted in a functional expression of the human HO-1 gene; the human HO-1 mRNA was detected, and enzyme activity increased threefold. Human HO-1 mRNA was detected in the retina after microinjection of the Adv-HHO construct into the subretinal space. Microinjection into the vitreous resulted in HO-1 mRNA expression in the corneal endothelium, iris, lens, and retina; after intracameral injection of the Adv-HHO construct, human HO-1 mRNA was detected in corneal epithelium and endothelium, ciliary body, lens, and iris. Regardless of the injection site, transfected human HO-1 mRNA was undetectable in tissues outside the eye, that is, brain, liver, and kidney. These results demonstrated a tissue-selective functional transfer of the human HO-1 gene into rabbit ocular tissues in vivo. This technique may be a promising means for delivering HO-1 gene in vivo as a protective mechanism against oxidative stress that contributes to the pathogenesis of

Structural characterization of human heme oxygenase-1 in complex with azole-based inhibitors.

Science.gov (United States)

Rahman, Mona N; Vlahakis, Jason Z; Roman, Gheorghe; Vukomanovic, Dragic; Szarek, Walter A; Nakatsu, Kanji; Jia, Zongchao

2010-03-01

The development of inhibitors specific for heme oxygenases (HO) aims to provide powerful tools in understanding the HO system. Based on the lead structure (2S, 4S)-2-[2-(4-chlorophenyl)ethyl]-2-[(1H-imidazol-1-yl)methyl]-4-[((4-aminophenyl)thio)methyl]-1,3-dioxolane (azalanstat, QC-1) we have synthesized structural modifications to develop novel and selective HO inhibitors. The structural study of human HO-1 (hHO-1) in complex with a select group of the inhibitors was initiated using X-ray crystallographic techniques. Comparison of the structures of four such compounds each in complex with hHO-1 revealed a common binding mode, despite having different structural fragments. The compounds bind to the distal side of heme through an azole "anchor" which coordinates with the heme iron. An expansion of the distal pocket, mainly due to distal helix flexibility, allows accommodation of the compounds without displacing heme or the critical Asp140 residue. Rather, binding displaces a catalytically critical water molecule and disrupts an ordered hydrogen-bond network involving Asp140. The presence of a triazole "anchor" may provide further stability via a hydrogen bond with the protein. A hydrophobic pocket acts to stabilize the region occupied by the phenyl or adamantanyl moieties of these compounds. Further, a secondary hydrophobic pocket is formed via "induced fit" to accommodate bulky substituents at the 4-position of the dioxolane ring. Copyright 2009 Elsevier Inc. All rights reserved.

Free electron laser experiments using a long pulse induction linac

International Nuclear Information System (INIS)

Pasour, J.A.; Lucey, R.

1983-01-01

The NRL Long Pulse Induction Linac is being employed in a Free Electron Laser (FEL) experiment. The authors present results of beam transport and focusing experiments as well as measurements of the output radiation generated by various magnetic wigglers. The electron gun of the accelerator presently has a 17-cmdiam. cold cathode which is located in a nearly zero magnetic field (B /SUB z/ less than or equal to 5 G). The gun voltage is flat to within approx. = + or - 5% for 1.5 μsec with this graphite brush cathode. The beam is focused by a series of solenoidal coils as it propagates through the 4-m-long accelerator. 2 A solenoidal field which can be varied from 1-10 kG confines the beam in the FEL interaction region. Previous experiments were limited by poor beam transport, focusing, and matching into the relatively large solenoidal field in the FEL region. By smoothing the axial magnetic field profile in the accelerator and making a more adiabatic transition from the low field in the accelerator to the high field in the FEL, beam transport into the wiggler has been substantially improved. Currently, a 700 kV beam with I > 500 A and r /SUB b/ < 0.75 cm is transported through the FEL region. Beam transport is in qualitative agreement with envelope code calculations

Ethoxyresorufin-O-deethylase (EROD) induction in rainbow trout exposed to diluted oil sand wastewater

International Nuclear Information System (INIS)

Verbeek, A.; Mackay, W.; Birkholz, D.

1995-01-01

Toxic industrial wastewaters, such as those from oil sands extraction, must be assessed for their potential sublethal effects before they can be safely disposed in the environment. The induction of ethoxyresorufin-O-deethylase activity was assessed as a potential bioindicator of sublethal stress in rainbow trout exposed to sublethal concentrations of oil sands tailings water. The mixed-function oxygenase system in rainbow trout responded rapidly following a definable concentration-response relationship; however, it proved to be a relatively insensitive indicator of sublethal exposure to oil sands tailings water. Increased activity and maximal induction, as a result of exposure to 0.3 and 0.6 times the LC 50 (Toxic Units), occurred rapidly within 24 hours of exposure. The linearity of the relationship between the concentration of oil sands tailings pond water and ethoxyresorufin-O-deethylase activity, expressed by the following regression equation, In EROD = 3.68 (conc.) + 3.20, had an r 2 value of 0.593. Maximal induction required 0.4--0.8 Toxic Units. The absolute level of maximal induction was only one-fifth to one-sixth of the potential induction as found in response to the positive control, 0.5 mg/kg β-naphthoflavone (i.p.). The authors also present data that suggests that the different levels of induction observed in trout exposed to tailings pond water vs those injected with 0.5 mg/kg β-naphthoflavone (i.p.) may be indicative of two different P450 isoforms, the CYP4Al isoform responding to the organic acidic surfactants in oil sands tailings pond water and the CYP1A1 isoform, the isoform generally associated with most xenobiotic transformation in fish, responding to β-naphthoflavone

Axial electric wake field inside the induction gap exited by the intense electron beam

International Nuclear Information System (INIS)

Zhang Kaizhi; Zhang Huang; Long Jidong; Yang Guojun; He Xiaozhong; Wang Huacen

2008-01-01

While an intense electron beam passes through the accelerating gaps of a linear induction accelerator, a strong wake field will be excited. In this paper a relatively simple model is established based on the interaction between the transverse magnetic wake field and the electron beam, and the numerical calculation in succession generates a magnetic wake field distribution along the accelerator and along the beam pulse as well. The axial electric wake field is derived based on the relation between field components of a resonant mode. According to some principles in existence, the influence of this field on the high voltage properties of the induction gap is analyzed. The Dragon-I accelerator is taken as an example, and its maximum electric wake field is about 17 kV/cm, which means the effect of the wake field is noticeable. (authors)

Particle-in-cell simulations of electron beam control using an inductive current divider

Energy Technology Data Exchange (ETDEWEB)

Swanekamp, S. B.; Angus, J. R.; Cooperstein, G.; Ottinger, P. F.; Richardson, A. S.; Schumer, J. W.; Weber, B. V. [Plasma Physics Division, Naval Research Laboratory, Washington, District of Columbia 20375 (United States)

2015-11-15

Kinetic, time-dependent, electromagnetic, particle-in-cell simulations of the inductive current divider are presented. The inductive current divider is a passive method for controlling the trajectory of an intense, hollow electron beam using a vacuum structure that inductively splits the beam's return current. The current divider concept was proposed and studied theoretically in a previous publication [Swanekamp et al., Phys. Plasmas 22, 023107 (2015)]. A central post carries a portion of the return current (I{sub 1}), while the outer conductor carries the remainder (I{sub 2}) with the injected beam current given by I{sub b} = I{sub 1} + I{sub 2}. The simulations are in agreement with the theory which predicts that the total force on the beam trajectory is proportional to (I{sub 2}−I{sub 1}) and the force on the beam envelope is proportional to I{sub b}. Independent control over both the current density and the beam angle at the target is possible by choosing the appropriate current-divider geometry. The root-mean-square (RMS) beam emittance (ε{sub RMS}) varies as the beam propagates through the current divider to the target. For applications where control of the beam trajectory is desired and the current density at the target is similar to the current density at the entrance foil, there is a modest 20% increase in ε{sub RMS} at the target. For other applications where the beam is pinched to a current density ∼5 times larger at the target, ε{sub RMS} is 2–3 times larger at the target.

Overexpressed human heme Oxygenase-1 decreases adipogenesis in pigs and porcine adipose-derived stem cells.

Science.gov (United States)

Park, Eun Jung; Koo, Ok Jae; Lee, Byeong Chun

2015-11-27

Adipose-derived mesenchymal stem cells (ADSC) are multipotent, which means they are able to differentiate into several lineages in vivo and in vitro under proper conditions. This indicates it is possible to determine the direction of differentiation of ADSC by controlling the microenvironment. Heme oxygenase 1 (HO-1), a type of antioxidant enzyme, attenuates adipogenicity and obesity. We produced transgenic pigs overexpressing human HO-1 (hHO-1-Tg), and found that these animals have little fatty tissue when autopsied. To determine whether overexpressed human HO-1 suppresses adipogenesis in pigs, we analyzed body weight increases of hHO-1-Tg pigs and wild type (WT) pigs of the same strain, and induced adipogenic differentiation of ADSC derived from WT and hHO-1-Tg pigs. The hHO-1-Tg pigs had lower body weights than WT pigs from 16 weeks of age until they died. In addition, hHO-1-Tg ADSC showed reduced adipogenic differentiation and expression of adipogenic molecular markers such as PPARγ and C/EBPα compared to WT ADSC. These results suggest that HO-1 overexpression reduces adipogenesis both in vivo and in vitro, which could support identification of therapeutic targets of obesity and related metabolic diseases. Copyright © 2015 Elsevier Inc. All rights reserved.

An improved method for purification of recombinant truncated heme oxygenase-1 by expanded bed adsorption and gel filtration.

Science.gov (United States)

Hu, Hong-Bo; Wang, Wei; Han, Ling; Zhou, Wen-Pu; Zhang, Xue-Hong

2007-03-01

Recombinant truncated human heme oxygenase-1 (hHO-1) expressed in Escherichia coli was efficiently separated and purified from feedstock by DEAE-ion exchange expanded bed adsorption. Protocol optimization of hHO-1 on DEAE adsorbent resulted in adsorption in 0 M NaCl and elution in 150 mM NaCl at a pH of 8.5. The active enzyme fractions separated from the expanded bed column were further purified by a Superdex 75 gel filtration step. The specific hHO-1 activity increased from 0.82 +/- 0.05 to 24.8 +/- 1.8 U/mg during the whole purification steps. The recovery and purification factor of truncated hHO-1 of the whole purification were 72.7 +/- 4.7 and 30.2 +/- 2.3%, respectively. This purification process can decrease the demand on the preparation of feedstock and simplify the purification process.

Expression and characterization of full-length human heme oxygenase-1: the presence of intact membrane-binding region leads to increased binding affinity for NADPH cytochrome P450 reductase.

Science.gov (United States)

Huber, Warren J; Backes, Wayne L

2007-10-30

Heme oxygenase-1 (HO-1) is the chief regulatory enzyme in the oxidative degradation of heme to biliverdin. In the process of heme degradation, HO-1 receives the electrons necessary for catalysis from the flavoprotein NADPH cytochrome P450 reductase (CPR), releasing free iron and carbon monoxide. Much of the recent research involving heme oxygenase has been done using a 30 kDa soluble form of the enzyme, which lacks the membrane binding region (C-terminal 23 amino acids). The goal of this study was to express and purify a full-length human HO-1 (hHO-1) protein; however, due to the lability of the full-length form, a rapid purification procedure was required. This was accomplished by use of a glutathione-s-transferase (GST)-tagged hHO-1 construct. Although the procedure permitted the generation of a full-length HO-1, this form was contaminated with a 30 kDa degradation product that could not be eliminated. Therefore, attempts were made to remove a putative secondary thrombin cleavage site by a conservative mutation of amino acid 254, which replaces arginine with lysine. This mutation allowed the expression and purification of a full-length hHO-1 protein. Unlike wild type (WT) HO-1, the R254K mutant could be purified to a single 32 kDa protein capable of degrading heme at the same rate as the WT enzyme. The R254K full-length form had a specific activity of approximately 200-225 nmol of bilirubin h-1 nmol-1 HO-1 as compared to approximately 140-150 nmol of bilirubin h-1 nmol-1 for the WT form, which contains the 30 kDa contaminant. This is a 2-3-fold increase from the previously reported soluble 30 kDa HO-1, suggesting that the C-terminal 23 amino acids are essential for maximal catalytic activity. Because the membrane-spanning domain is present, the full-length hHO-1 has the potential to incorporate into phospholipid membranes, which can be reconstituted at known concentrations, in combination with other endoplasmic reticulum resident enzymes.

Inhibitory Effects of Benzaldehyde Derivatives from the Marine Fungus Eurotium sp. SF-5989 on Inflammatory Mediators via the Induction of Heme Oxygenase-1 in Lipopolysaccharide-Stimulated RAW264.7 Macrophages

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Kyoung-Su Kim

2014-12-01

Full Text Available Two benzaldehyde derivatives, flavoglaucin (1 and isotetrahydro-auroglaucin (2, were isolated from the marine fungus Eurotium sp. SF-5989 through bioassay- and 1H NMR-guided investigation. In this study, we evaluated the anti-inflammatory effects of these compounds in lipopolysaccharide (LPS-stimulated RAW264.7 macrophages. We demonstrated that compounds 1 and 2 markedly inhibited LPS-induced nitric oxide (NO and prostaglandin E2 (PGE2 production by suppressing inducible nitric oxide synthase (iNOS and cyclooxygenase-2 (COX-2 protein expression without affecting cell viability. We also demonstrated that the compounds reduced the secretion of pro-inflammatory cytokines such as tumor necrosis factor-α (TNF-α, interleukin-1β (IL-1β and interleukin-6 (IL-6. Furthermore, compounds 1 and 2 inhibited LPS-induced nuclear factor-κB (NF-κB activation by suppressing phosphorylation of IkappaB (IκB. These results indicated that the anti-inflammatory effects of these benzaldehyde derivatives in LPS-stimulated RAW264.7 macrophages were due to the inactivation of the NF-κB pathway. In addition, compounds 1 and 2 induced heme oxygenase-1 (HO-1 expression through the nuclear transcription factor-E2–related factor 2 (Nrf2 translocation. The inhibitory effects of compounds 1 and 2 on the production of pro-inflammatory mediators and on NF-κB binding activity were reversed by HO-1 inhibitor tin protoporphyrin (SnPP. Thus, the anti-inflammatory effects of compounds 1 and 2 also correlated with their ability of inducing HO-1 expression.

Human heme oxygenase-1 gene transfer lowers blood pressure and promotes growth in spontaneously hypertensive rats.

Science.gov (United States)

Sabaawy, H E; Zhang, F; Nguyen, X; ElHosseiny, A; Nasjletti, A; Schwartzman, M; Dennery, P; Kappas, A; Abraham, N G

2001-08-01

Heme oxygenase (HO) catalyzes the conversion of heme to biliverdin, with release of free iron and carbon monoxide. Both heme and carbon monoxide have been implicated in the regulation of vascular tone. A retroviral vector containing human HO-1 cDNA (LSN-HHO-1) was constructed and subjected to purification and concentration of the viral particles to achieve 5x10(9) to 1x10(10) colony-forming units per milliliter. The ability of concentrated infectious viral particles to express human HO-1 (HHO-1) in vivo was tested. A single intracardiac injection of the concentrated infectious viral particles (expressing HHO-1) to 5-day-old spontaneously hypertensive rats resulted in functional expression of the HHO-1 gene and attenuation of the development of hypertension. Rats expressing HHO-1 showed a significant decrease in urinary excretion of a vasoconstrictor arachidonic acid metabolite and a reduction in myogenic responses to increased intraluminal pressure in isolated arterioles. Unexpectedly, HHO-1 chimeric rats showed a simultaneous significant proportionate increase in somatic growth. Thus, delivery of HHO-1 gene by retroviral vector attenuates the development of hypertension and promotes body growth in spontaneously hypertensive rats.

Association of heme oxygenase-1 GT-repeat polymorphism with blood pressure phenotypes and its relevance to future cardiovascular mortality risk: an observation based on arsenic-exposed individuals.

Science.gov (United States)

Wu, Meei-Maan; Chiou, Hung-Yi; Chen, Chi-Ling; Hsu, Ling-I; Lien, Li-Ming; Wang, Chih-Hao; Hsieh, Yi-Chen; Wang, Yuan-Hung; Hsueh, Yu-Mei; Lee, Te-Chang; Cheng, Wen-Fang; Chen, Chien-Jen

2011-12-01

Heme oxygenase (HO)-1 is up-regulated as a cellular defense responding to stressful stimuli in experimental studies. A GT-repeat length polymorphism in the HO-1 gene promoter was inversely correlated to HO-1 induction. Here, we reported the association of GT-repeat polymorphism with blood pressure (BP) phenotypes, and their interaction on cardiovascular (CV) mortality risk in arsenic-exposed cohorts. Associations of GT-repeat polymorphism with BP phenotypes were investigated at baseline in a cross-sectional design. Effect of GT-repeat polymorphism on CV mortality was investigated in a longitudinal design stratified by hypertension. GT-repeat variants were grouped by S (accounting for CV covariates. Totally, 894 participants were recruited and analyzed. At baseline, carriers with HO-1 S alleles had lower diastolic BP (L/S genotypes, P = 0.014) and a lower possibility of being hypertensive (L/S genotypes, P = 0.048). After follow-up, HO-1 S allele was significantly associated with a reduced CV risk in hypertensive participants [relative mortality ratio (RMR) 0.27 (CI 0.11, 0.69), P = 0.007] but not in normotensive. Hypertensive participants without carrying the S allele had a 5.23-fold increased risk [RMR 5.23 (CI 1.99, 13.69), P = 0.0008] of CV mortality compared with normotensive carrying the S alleles. HO-1 short GT-repeat polymorphism may play a protective role in BP regulation and CV mortality risk in hypertensive individuals against environmental stressors. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Inductive crystal field control in layered metal oxides with correlated electrons

International Nuclear Information System (INIS)

Balachandran, P. V.; Cammarata, A.; Rondinelli, J. M.; Nelson-Cheeseman, B. B.; Bhattacharya, A.

2014-01-01

We show that the NiO 6 crystal field energies can be tailored indirectly via heterovalent A cation ordering in layered (La,A)NiO 4 Ruddlesden–Popper (RP) oxides, where A = Sr, Ca, or Ba, using density functional calculations. We leverage as a driving force the electrostatic interactions between charged [LaO] 1+ and neutral [AO] 0 planes to inductively tune the Ni–O bond distortions, without intentional doping or epitaxial strain, altering the correlated d-orbital energies. We use this strategy to design cation ordered LaCaNiO 4 and LaBaNiO 4 with distortions favoring enhanced Ni e g orbital polarization, and find local electronic structure signatures analogous to those in RP La-cuprates, i.e., parent phases of the high-temperature superconducting oxides

Linear induction accelerators

International Nuclear Information System (INIS)

Briggs, R.J.

1986-06-01

The development of linear induction accelerators has been motivated by applications requiring high-pulsed currents of charged particles at voltages exceeding the capability of single-stage, diode-type accelerators and at currents too high for rf accelerators. In principle, one can accelerate charged particles to arbitrarily high voltages using a multi-stage induction machine, but the 50-MeV, 10-kA Advanced Test Accelerator (ATA) at LLNL is the highest voltage machine in existence at this time. The advent of magnetic pulse power systems makes sustained operation at high-repetition rates practical, and this capability for high-average power is very likely to open up many new applications of induction machines in the future. This paper surveys the US induction linac technology with primary emphasis on electron machines. A simplified description of how induction machines couple energy to the electron beam is given, to illustrate many of the general issues that bound the design space of induction linacs

Upregulation of human heme oxygenase gene expression by Ets-family proteins.

Science.gov (United States)

Deramaudt, B M; Remy, P; Abraham, N G

1999-03-01

Overexpression of human heme oxygenase-1 has been shown to have the potential to promote EC proliferation and angiogenesis. Since Ets-family proteins have been shown to play an important role in angiogenesis, we investigated the presence of ETS binding sites (EBS), GGAA/T, and ETS protein contributing to human HO-1 gene expression. Several chloramphenicol acetyltransferase constructs were examined in order to analyze the effect of ETS family proteins on the transduction of HO-1 in Xenopus oocytes and in microvessel endothelial cells. Heme oxygenase promoter activity was up-regulated by FLI-1ERGETS-1 protein(s). Chloramphenicol acetyltransferase (CAT) assays demonstrated that the promoter region (-1500 to +19) contains positive and negative control elements and that all three members of the ETS protein family were responsible for the up-regulation of HHO-1. Electrophoretic mobility shift assays (EMSA), performed with nuclear extracts from endothelial cells overexpressing HHO-1 gene, and specific HHO-1 oligonucleotides probes containing putative EBS resulted in a specific and marked bandshift. Synergistic binding was observed in EMSA between AP-1 on the one hand, FLI-1, ERG, and ETS-1 protein on the other. Moreover, 5'-deletion analysis demonstrated the existence of a negative control element of HHO-1 expression located between positions -1500 and -120 on the HHO-1 promoter. The presence of regulatory sequences for transcription factors such as ETS-1, FLI-1, or ERG, whose activity is associated with cell proliferation, endothelial cell differentiation, and matrix metalloproteinase transduction, may be an indication of the important role that HO-1 may play in coronary collateral circulation, tumor growth, angiogenesis, and hemoglobin-induced endothelial cell injuries.

Effect of heme oxygenase-1 on the protection of ischemia reperfusion injury of bile duct in rats after liver transplantation.

Science.gov (United States)

Zhan, Xi; Zhang, Zhiqing; Huang, Hanfei; Zhang, Yujun; Zeng, Zhong

2018-06-01

To investigate the effect of heme oxygenase-1 (HO-1) on the ischemic reperfusion injury (IRI) of bile duct in rat models after liver transplantation. 320 SD rats were equally and randomly divided into 5 groups, which were group A receiving injection of 3×10 8 /pfu/ml adenovirus (adv), group B with donor receiving Adv-HO-1 and recipient receiving Adv-HO-1-siRNA, group C with donor and recipient both receiving Adv-HO-1, group D with donor receiving Adv-HO-1-siRNA and recipient receiving Adv-HO-1, and group E with donor and recipient both receiving Adv-HO-1-siRNA at 24h before liver transplantation. Donor liver was stored in UW liquid at 4°C followed by measuring HO-1 level by western blot before transplantation. On d1, d3, d7 and d14, serum and liver was isolated for analysis of liver function, inflammatory cell infiltration by H&E staining, ultrastructure of liver by transmission electron microscopy as well as the expression of HO-1, Bsep, Mrp2 and Ntcp by western blot. Compared with group D and E, group B and C displayed improved liver function as demonstrated by lower level of ALT, AST, LDH, TBIL, ALP and GGT, increased secretion of TBA and PL as well as expression of transporter proteins (Bsep, Mrp2 and Ntcp), reduced inflammatory cells infiltration and liver injury. Our study demonstrated that overexpression of HO-1 in donor liver can ameliorate the damage to bile duct and liver, and improved liver function, suggesting HO-1 might be a new therapeutic target in the treatment of IRI after liver transplantation. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Epigallocatechin-3-gallate (EGCG) protects skin cells from ionizing radiation via heme oxygenase-1 (HO-1) overexpression

International Nuclear Information System (INIS)

Zhu Wei; Xu Jing; Ge Yangyang

2014-01-01

Epigallocatechin-3-gallate (EGCG), the major polyphenolic constituent of green tea, is a potent antioxidant and free radical scavenger that may have therapeutic applications for the treatment of many disorders. Radiation therapy is widely used for the treatment of various types of cancers; however, radiation-induced skin injury remains a serious concern. EGCG has not yet been reported as protecting skin cells against ionizing radiation. In the present study, we investigated whether EGCG confers cytoprotection against ionizing radiation. We found that, compared with the control, pretreatment with EGCG significantly enhanced the viability of human skin cells that were irradiated with X-rays, and decreased apoptosis induced by X-ray irradiation. Mito-Tracker assay showed that EGCG suppressed the damage to mitochondria induced by ionizing radiation via upregulation of SOD2. Reactive oxygen species (ROS) in HaCaT cells were significantly reduced when pretreated with EGCG before irradiation. Radiation-induced γH2AX foci, which are representative of DNA double-strand breaks, were decreased by pretreatment with EGCG. Furthermore, EGCG induced the expression of the cytoprotective molecule heme oxygenase-1 (HO-1) in a dose-dependent manner via transcriptional activation. HO-1 knockdown or treatment with the HO-1 inhibitor tin protoporphyrin (SnPPIX) reversed the protective role of EGCG, indicating an important role for HO-1. These results suggest that EGCG offers a new strategy for protecting skin against ionizing radiation. (author)

Edaravone protected PC12 cells against MPP(+)-cytoxicity via inhibiting oxidative stress and up-regulating heme oxygenase-1 expression.

Science.gov (United States)

Cheng, Baohua; Guo, Yunliang; Li, Chuangang; Ji, Bingyuan; Pan, Yanyou; Chen, Jing; Bai, Bo

2014-08-15

Oxidative stress is involved in the pathogenesis of Parkinson's disease (PD). Edaravone has been shown to have a neuroprotective effect. In the present work, we investigated the effect of edaravone on 1-methyl-4-phenylpyridinium (MPP(+))-treated PC12 cells. Edaravone inhibited the decrease of cell viability and apoptosis induced by MPP(+) in PC12 cells. In addition, edaravone alleviated intracellular reactive oxygen species (ROS) production. MPP(+) induced heme oxygenase-1 (HO-1) expression, which was further enhanced by edaravone. The inhibitor of HO-1 zinc protoporphyrin-IX attenuated the neuroprotection of edaravone. So edaravone protected PC12 cells against MPP(+)-cytoxicity via inhibiting oxidative stress and up-regulating HO-1 expression. The data showed that edaravone was neuroprotective and could be potentially therapeutics for PD in future. Copyright © 2014 Elsevier B.V. All rights reserved.

Protection from ischemic heart injury by a vigilant heme oxygenase-1 plasmid system.

Science.gov (United States)

Tang, Yao Liang; Tang, Yi; Zhang, Y Clare; Qian, Keping; Shen, Leping; Phillips, M Ian

2004-04-01

Although human heme oxygenase-1 (hHO-1) could provide a useful approach for cellular protection in the ischemic heart, constitutive overexpression of hHO-1 may lead to unwanted side effects. To avoid this, we designed a hypoxia-regulated hHO-1 gene therapy system that can be switched on and off. This vigilant plasmid system is composed of myosin light chain-2v promoter and a gene switch that is based on an oxygen-dependent degradation domain from the hypoxia inducible factor-1-alpha. The vector can sense ischemia and switch on the hHO-1 gene system, specifically in the heart. In an in vivo experiment, the vigilant hHO-1 plasmid or saline was injected intramyocardially into myocardial infarction mice or sham operation mice. After gene transfer, expression of hHO-1 was only detected in the ischemic heart treated with vigilant hHO-1 plasmids. Masson trichrome staining showed significantly fewer fibrotic areas in vigilant hHO-1 plasmids-treated mice compared with saline control (43.0%+/-4.8% versus 62.5%+/-3.3%, PhHO-1 expression in peri-infarct border areas, concomitant with higher Bcl-2 levels and lower Bax, Bak, and caspase 3 levels in the ischemic myocardium compared with saline control. By use of a cardiac catheter, heart from vigilant hHO-1 plasmids-treated mice showed improved recovery of contractile and diastolic performance after myocardial infarction compared with saline control. This study documents the beneficial regulation and therapeutic potential of vigilant plasmid-mediated hHO-1 gene transfer. This novel gene transfer strategy can provide cardiac-specific protection from future repeated bouts of ischemic injury.

Heme oxygenase activity increases after exercise in healthy volunteers

Science.gov (United States)

AbstractHeme oxygenase (HO) is an essential, rate-limiting protein which participates in the catabolism of heme to iron, carbon monoxide (CO), and biliverdin. The alpha methene bridge carbon of the heme is eliminated as CO which can be measured as blood carboxyhemoglobin (COHb)....

Energy efficient power electronic controller for a capacitor-run single-phase induction motor

International Nuclear Information System (INIS)

Saravana Ilango, G.; Samidurai, K.; Roykumar, M.; Thanushkodi, K.

2009-01-01

At present the speed control of a capacitor-run single-phase induction motor is being achieved by using triac based voltage regulators. This paper proposes a new scheme; an electronic transformer acts as a voltage regulator. Performance comparison is made between these two schemes in this paper. It is found that the proposed scheme has superior operating and performance characteristics. Experimental results show that apart from improvement in performance with respect to power factor and total harmonic distortion an appreciable amount of energy saving is also obtained in the electronic transformer based scheme.

Heme oxygenase-1 regulates the progression of K/BxN serum transfer arthritis.

Directory of Open Access Journals (Sweden)

Rita Brines

Full Text Available Heme oxygenase-1 (HO-1 is induced in many cell types as a defense mechanism against stress. We have investigated the possible role of endogenous HO-1 in the effector phase of arthritis using the K/BxN serum transfer model of arthritis in HO-1 heterozygous and homozygous knock-out mice.Arthritis was induced in C57/Black-6 xFVB (HO-1(+/+, HO-1(+/- and HO-1(-/- mice by intraperitoneal injection of 150 µl serum from arthritic K/BxN mice at days 0 and 2. Blood was collected and animals were sacrificed at day 10. Histological analysis was performed in ankle sections. The levels of inflammatory mediators were measured in serum and paw homogenates by enzyme-linked immunosorbent assay or Multiplex technology. The incidence of arthritis was higher in HO-1(+/- and HO-1(-/- groups compared with HO-1(+/+. The inflammatory response was aggravated in HO-1(+/- mice as shown by arthritic score and the migration of inflammatory cells that could be related to the enhancement of CXCL-1 production. In addition, the HO-1(+/- group showed proteoglycan depletion significantly higher than HO-1(+/+ mice. Serum levels of matrix metalloproteinase-3, monocyte chemotactic protein-1, plasminogen activator inhibitor-1, E-selectin and intercellular adhesion molecule-1 were increased in arthritic HO-1(-/- mice, whereas vascular endothelial growth factor and some cytokines such as interferon-γ showed a reduction compared to HO-1(+/+ or HO-1(+/- mice. In addition, down-regulated gene expression of ferritin, glutathione S-reductase A1 and superoxide dismutase-2 was observed in the livers of arthritic HO-1(+/- animals.Endogenous HO-1 regulates the production of systemic and local inflammatory mediators and plays a protective role in K/BxN serum transfer arthritis.

Design of spherical electron gun for ultra high frequency, CW power inductive output tube

International Nuclear Information System (INIS)

Kaushik, Meenu; Joshi, L. M.

2016-01-01

Inductive Output Tube (IOT) is an amplifier that usually operates in UHF range. It is an electron tube whose basic structure is similar to conventional vacuum devices. This device is widely used in broadcast applications but is now being explored for scientific applications also specifically, particle accelerators and fusion plasma heating purposes. The paper describes the design approach of a spherical gridded electron gun of a 500 MHz, 100 kW CW power IOT. The electron gun structure has been simulated and optimized for operating voltage and current of 40kV and 3.5 A respectively. The electromagnetic analysis of this spherical electron gun has been carried out in CST and TRAK codes.

Design of spherical electron gun for ultra high frequency, CW power inductive output tube

Energy Technology Data Exchange (ETDEWEB)

Kaushik, Meenu, E-mail: mkceeri@gmail.com; Joshi, L. M., E-mail: lmj1953@gmail.com [Microwave Tubes Division, CSIR-Central Electronics Engineering Research Institute (CEERI), Pilani, Rajasthan (India); Academy of Scientific and Innovative Research (AcSIR), New Delhi (India)

2016-03-09

Inductive Output Tube (IOT) is an amplifier that usually operates in UHF range. It is an electron tube whose basic structure is similar to conventional vacuum devices. This device is widely used in broadcast applications but is now being explored for scientific applications also specifically, particle accelerators and fusion plasma heating purposes. The paper describes the design approach of a spherical gridded electron gun of a 500 MHz, 100 kW CW power IOT. The electron gun structure has been simulated and optimized for operating voltage and current of 40kV and 3.5 A respectively. The electromagnetic analysis of this spherical electron gun has been carried out in CST and TRAK codes.

Inductive crystal field control in layered metal oxides with correlated electrons

Energy Technology Data Exchange (ETDEWEB)

Balachandran, P. V.; Cammarata, A.; Rondinelli, J. M., E-mail: jrondinelli@nortwestern.edu [Department of Materials Science and Engineering, Drexel University, Philadelphia, Pennsylvania 19104 (United States); Nelson-Cheeseman, B. B. [School of Engineering, University of St. Thomas, St. Paul, Minnesota 55105 (United States); Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Bhattacharya, A. [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Center for Nanoscale Materials, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

2014-07-01

We show that the NiO{sub 6} crystal field energies can be tailored indirectly via heterovalent A cation ordering in layered (La,A)NiO{sub 4} Ruddlesden–Popper (RP) oxides, where A = Sr, Ca, or Ba, using density functional calculations. We leverage as a driving force the electrostatic interactions between charged [LaO]{sup 1+} and neutral [AO]{sup 0} planes to inductively tune the Ni–O bond distortions, without intentional doping or epitaxial strain, altering the correlated d-orbital energies. We use this strategy to design cation ordered LaCaNiO{sub 4} and LaBaNiO{sub 4} with distortions favoring enhanced Ni e{sub g} orbital polarization, and find local electronic structure signatures analogous to those in RP La-cuprates, i.e., parent phases of the high-temperature superconducting oxides.

Human heme oxygenase oxidation of 5- and 15-phenylhemes.

Science.gov (United States)

Wang, Jinling; Niemevz, Fernando; Lad, Latesh; Huang, Liusheng; Alvarez, Diego E; Buldain, Graciela; Poulos, Thomas L; de Montellano, Paul R Ortiz

2004-10-08

Human heme oxygenase-1 (hHO-1) catalyzes the O2-dependent oxidation of heme to biliverdin, CO, and free iron. Previous work indicated that electrophilic addition of the terminal oxygen of the ferric hydroperoxo complex to the alpha-meso-carbon gives 5-hydroxyheme. Earlier efforts to block this reaction with a 5-methyl substituent failed, as the reaction still gave biliverdin IXalpha. Surprisingly, a 15-methyl substituent caused exclusive cleavage at the gamma-meso-rather than at the normal, unsubstituted alpha-meso-carbon. No CO was formed in these reactions, but the fragment cleaved from the porphyrin eluded identification. We report here that hHO-1 cleaves 5-phenylheme to biliverdin IXalpha and oxidizes 15-phenylheme at the alpha-meso position to give 10-phenylbiliverdin IXalpha. The fragment extruded in the oxidation of 5-phenylheme is benzoic acid, one oxygen of which comes from O2 and the other from water. The 2.29- and 2.11-A crystal structures of the hHO-1 complexes with 1- and 15-phenylheme, respectively, show clear electron density for both the 5- and 15-phenyl rings in both molecules of the asymmetric unit. The overall structure of 15-phenylheme-hHO-1 is similar to that of heme-hHO-1 except for small changes in distal residues 141-150 and in the proximal Lys18 and Lys22. In the 5-phenylheme-hHO-1 structure, the phenyl-substituted heme occupies the same position as heme in the heme-HO-1 complex but the 5-phenyl substituent disrupts the rigid hydrophobic wall of residues Met34, Phe214, and residues 26-42 near the alpha-meso carbon. The results provide independent support for an electrophilic oxidation mechanism and support a role for stereochemical control of the reaction regiospecificity.

Myeloid Heme Oxygenase-1 Regulates the Acute Inflammatory Response to Zymosan in the Mouse Air Pouch

Directory of Open Access Journals (Sweden)

Rita Brines

2018-01-01

Full Text Available Heme oxygenase-1 (HO-1 is induced by many stimuli to modulate the activation and function of different cell types during innate immune responses. Although HO-1 has shown anti-inflammatory effects in different systems, there are few data on the contribution of myeloid HO-1 and its role in inflammatory processes is not well understood. To address this point, we have used HO-1M-KO mice with myeloid-restricted deletion of HO-1 to specifically investigate its influence on the acute inflammatory response to zymosan in vivo. In the mouse air pouch model, we have shown an exacerbated inflammation in HO-1M-KO mice with increased neutrophil infiltration accompanied by high levels of inflammatory mediators such as interleukin-1β, tumor necrosis factor-α, and prostaglandin E2. The expression of the degradative enzyme matrix metalloproteinase-3 (MMP-3 was also enhanced. In addition, we observed higher levels of serum MMP-3 in HO-1M-KO mice compared with control mice, suggesting the presence of systemic inflammation. Altogether, these findings demonstrate that myeloid HO-1 plays an anti-inflammatory role in the acute response to zymosan in vivo and suggest the interest of this target to regulate inflammatory processes.

Heme oxygenase-1 gene expression modulates angiotensin II-induced increase in blood pressure.

Science.gov (United States)

Yang, Liming; Quan, Shuo; Nasjletti, Alberto; Laniado-Schwartzman, Michal; Abraham, Nader G

2004-06-01

The heme-heme oxygenase (HO) system has been implicated in the regulation of vascular reactivity and blood pressure. This study examines the notion that overexpression of HO decreases pressor responsiveness to angiotensin II (Ang II). Five-day-old Sprague-Dawley rats received an intraleft ventricular injection of approximately 5x10(9) cfu/mL of retroviruses containing human HO-1 sense (LSN-HHO-1), rat HO-1 antisense (LSN-RHO-1-AS), or control retrovirus (LXSN). Three months later, rats were instrumented with femoral arterial and venous catheters for mean arterial pressure (MAP) determination and Ang II administration, respectively. Rats injected with LSN-HHO-1, but not with LXSN, expressed human HO-1 mRNA and protein in several tissues. BP increased with administration of Ang II in rats expressing and not expressing human HO-1. However, the Ang II-induced pressor response (mm Hg) in LSN-HHO-1 rats (16+/-3, 27+/-3, and 38+/-3 at 0.5, 2, and 10 ng) was surpassed (PHHO-1 rats with the HO inhibitor tin mesoporphyrin (SnMP) enhanced (P<0.05) the Ang II-induced pressor response to a level not different from that observed in LXSN rats. Rats injected with LSN-RHO-1-AS showed a decrease in renal HO-1 protein expression and HO activity relative to control LXSN rats. Administration of Ang II (0.1 to 2 ng) caused small (4 to 5 mm Hg) but significant increases in MAP in rats injected with LSN-RHO-1-AS (P<0.05) compared with rats injected with LXSN. These data demonstrate that overexpression of HO-1 brings about a reduction in pressor responsiveness to Ang II, which is most likely due to increased generation of an HO-1 product, presumably CO, with the ability to inhibit vascular reactivity to constrictor stimuli.

Induction machine handbook

CERN Document Server

Boldea, Ion

2002-01-01

Often called the workhorse of industry, the advent of power electronics and advances in digital control are transforming the induction motor into the racehorse of industrial motion control. Now, the classic texts on induction machines are nearly three decades old, while more recent books on electric motors lack the necessary depth and detail on induction machines.The Induction Machine Handbook fills industry's long-standing need for a comprehensive treatise embracing the many intricate facets of induction machine analysis and design. Moving gradually from simple to complex and from standard to

Heme oxygenase is not involved in the anti-proliferative effects of statins on pancreatic cancer cells

Czech Academy of Sciences Publication Activity Database

Váňová, K.; Boukalová, Štěpána; Gbelcová, H.; Muchová, L.; Neužil, Jiří; Gürlich, R.; Ruml, T.; Vítek, L.

2016-01-01

Roč. 16, May 12 (2016), č. článku 309. ISSN 1471-2407 R&D Projects: GA MZd NT14078; GA MŠk(CZ) ED1.1.00/02.0109 Institutional support: RVO:86652036 Keywords : Heme * Heme oxygenase * Pancreatic cancer * Statins Subject RIV: FD - Oncology ; Hematology Impact factor: 3.288, year: 2016

A generalized electron energy probability function for inductively coupled plasmas under conditions of nonlocal electron kinetics

Science.gov (United States)

Mouchtouris, S.; Kokkoris, G.

2018-01-01

A generalized equation for the electron energy probability function (EEPF) of inductively coupled Ar plasmas is proposed under conditions of nonlocal electron kinetics and diffusive cooling. The proposed equation describes the local EEPF in a discharge and the independent variable is the kinetic energy of electrons. The EEPF consists of a bulk and a depleted tail part and incorporates the effect of the plasma potential, Vp, and pressure. Due to diffusive cooling, the break point of the EEPF is eVp. The pressure alters the shape of the bulk and the slope of the tail part. The parameters of the proposed EEPF are extracted by fitting to measure EEPFs (at one point in the reactor) at different pressures. By coupling the proposed EEPF with a hybrid plasma model, measurements in the gaseous electronics conference reference reactor concerning (a) the electron density and temperature and the plasma potential, either spatially resolved or at different pressure (10-50 mTorr) and power, and (b) the ion current density of the electrode, are well reproduced. The effect of the choice of the EEPF on the results is investigated by a comparison to an EEPF coming from the Boltzmann equation (local electron kinetics approach) and to a Maxwellian EEPF. The accuracy of the results and the fact that the proposed EEPF is predefined renders its use a reliable alternative with a low computational cost compared to stochastic electron kinetic models at low pressure conditions, which can be extended to other gases and/or different electron heating mechanisms.

Heme oxygenase-1 modulates degeneration of the intervertebral disc after puncture in Bach 1 deficient mice.

Science.gov (United States)

Ohta, Ryo; Tanaka, Nobuhiro; Nakanishi, Kazuyoshi; Kamei, Naosuke; Nakamae, Toshio; Izumi, Bunichiro; Fujioka, Yuki; Ochi, Mitsuo

2012-09-01

Intervertebral disc degeneration is considered to be a major feature of low back pain. Furthermore, oxidative stress has been shown to be an important factor in degenerative diseases such as osteoarthritis and is considered a cause of intervertebral disc degeneration. The purpose of this study was to clarify the correlation between oxidative stress and intervertebral disc degeneration using Broad complex-Tramtrack-Bric-a-brac and cap'n'collar homology 1 deficient (Bach 1-/-) mice which highly express heme oxygenase-1 (HO-1). HO-1 protects cells from oxidative stress. Caudal discs of 12-week-old and 1-year-old mice were evaluated as age-related models. Each group and period, 5 mice (a total of 20 mice, a total of 20 discs) were evaluated as age-related model. C9-C10 caudal discs in 12-week-old Bach 1-/- and wild-type mice were punctured using a 29-gauge needle as annulus puncture model. Each group and period, 5 mice (a total of 60 mice, a total of 60 discs) were evaluated. The progress of disc degeneration was evaluated at pre-puncture, 1, 2, 4, 8 and 12 weeks post-puncture. Radiographic, histologic and immunohistologic analysis were performed to compare between Bach 1-/- and wild-type mice. In the age-related model, there were no significant differences between Bach 1-/- and wild-type mice radiologically and histologically. However, in the annulus puncture model, histological scoring revealed significant difference at 8 and 12 weeks post-puncture. The number of HO-1 positive cells was significantly greater in Bach 1-/- mice at every period. The apoptosis rate was significantly lower at 1 and 2 weeks post-puncture in Bach 1-/- mice. Oxidative stress prevention may avoid the degenerative process of the intervertebral disc after puncture, reducing the number of apoptosis cells. High HO-1 expression may also inhibit oxidative stress and delay the process of intervertebral disc degeneration.

Evidence for allosterism in ribulose-1,5-bisphosphate carboxylase/oxygenase from comfrey

Energy Technology Data Exchange (ETDEWEB)

Mueller, D.D.; Bolden, T.D.

1986-05-01

Evidence has been obtained suggesting that ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) is an allosteric enzyme in the sense that it shows cooperative active site binding, cooperative interactions between the activation and active sites and significant binding of some metabolites at a second site. Investigation of the binding of a potent competitive inhibitor. 2-carboxymannitol-1,6-bisphosphate (CMBP) by /sup 31/P-NMR indicated essentially 1:1 binding with the active sites of comfrey RuBisCo. Among the interactions of competitive inhibitors, as measured by difference UV spectroscopy, the binding curves for ortho-phosphate and ribose-5-phosphate were better fitted by a Monod-Wyman-Changeux model than by an independent site model, whereas the binding of CMBP and 2-phosphoglycolate were not. Difference UV methods also were used to study activation by CO/sub 2/ which at pH 7.9 in 10 mM MgCl/sub 2/ showed positive cooperativity with k = 100 +/- 3 ..mu..M (based on pK/sub a/ = 6.4 for the CO/sub 2/-HCO/sub 3//sup -/ equilibrium) and L = 3.5 +/- 0.7. Addition of saturating amounts of CMBP and lowering the MgCl/sub 2/ to 2 mM still gave a sigmoidal curve but it was shifted to higher CO/sub 2/ concentrations (k = 124 +/- 2 ..mu..M and L = 31 +/- 3). In the absence of CMBP the same conditions gave k = 26 +/- 2 ..mu..M for L = 3.5. Conversely, k was 0.96 +/- 0.08 ..mu..M for CMBP in 0.5 mM MgCl/sub 2/ without added NaHCO/sub 3/ but was 21 +/- 0.06 ..mu..M in 10 MgCl/sub 2/ and 2 mM NaHCO/sub 3/, pH 7.3.

Evidence for allosterism in ribulose-1,5-bisphosphate carboxylase/oxygenase from comfrey

International Nuclear Information System (INIS)

Mueller, D.D.; Bolden, T.D.

1986-01-01

Evidence has been obtained suggesting that ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) is an allosteric enzyme in the sense that it shows cooperative active site binding, cooperative interactions between the activation and active sites and significant binding of some metabolites at a second site. Investigation of the binding of a potent competitive inhibitor. 2-carboxymannitol-1,6-bisphosphate (CMBP) by 31 P-NMR indicated essentially 1:1 binding with the active sites of comfrey RuBisCo. Among the interactions of competitive inhibitors, as measured by difference UV spectroscopy, the binding curves for ortho-phosphate and ribose-5-phosphate were better fitted by a Monod-Wyman-Changeux model than by an independent site model, whereas the binding of CMBP and 2-phosphoglycolate were not. Difference UV methods also were used to study activation by CO 2 which at pH 7.9 in 10 mM MgCl 2 showed positive cooperativity with k = 100 +/- 3 μM (based on pK/sub a/ = 6.4 for the CO 2 -HCO 3 - equilibrium) and L = 3.5 +/- 0.7. Addition of saturating amounts of CMBP and lowering the MgCl 2 to 2 mM still gave a sigmoidal curve but it was shifted to higher CO 2 concentrations (k = 124 +/- 2 μM and L = 31 +/- 3). In the absence of CMBP the same conditions gave k = 26 +/- 2 μM for L = 3.5. Conversely, k was 0.96 +/- 0.08 μM for CMBP in 0.5 mM MgCl 2 without added NaHCO 3 but was 21 +/- 0.06 μM in 10 MgCl 2 and 2 mM NaHCO 3 , pH 7.3

Adenoviral transfer of the heme oxygenase-1 gene protects striatal astrocytes from heme-mediated oxidative injury.

Science.gov (United States)

Teng, Zhi-Ping; Chen, Jing; Chau, Lee-Young; Galunic, Nicholas; Regan, Raymond F

2004-11-01

Heme oxygenase-1 (HO-1) is induced in the CNS after hemorrhage, and may have an effect on injury to surrounding tissue. Hemin, the preferred substrate of HO, is a neurotoxin that is present in intracranial hematomas. In a prior study, we observed that HO inhibitors increased the vulnerability of cultured cortical astrocytes to heme-mediated oxidative injury. To investigate the effect of HO more specifically, we used an adenoviral vector encoding the human HO-1 gene to specifically increase HO-1 expression. Incubation with 100 MOI of the HO-1 adenovirus (Adv-HHO-1) for 24 h increased both HO-1 protein and HO activity; a control adenovirus lacking the HO-1 gene had no effect. Using a DNA probe that was specific for human HO-1, 80.5 +/- 7.2% of astrocytes were observed to be infected by in situ hybridization. The cell death produced by 30-60 microM hemin was significantly reduced by pretreatment with 100 MOI Adv-HHO-1, as assessed by LDH release, propidium iodide exclusion, and MTT reduction assay. The threefold increase in cell protein oxidation produced by hemin was also attenuated in cultures pretreated with Adv-HHO-1. These results support the hypothesis that HO-1 protects astrocytes from heme-mediated oxidative injury. Specifically increasing astrocytic HO-1 by gene transfer may have a beneficial effect on hemorrhagic CNS injury.

Heme Oxygenase-1 Gene Therapy Provides Cardioprotection Via Control of Post-Ischemic Inflammation: An Experimental Study in a Pre-Clinical Pig Model.

Science.gov (United States)

Hinkel, Rabea; Lange, Philipp; Petersen, Björn; Gottlieb, Elena; Ng, Judy King Man; Finger, Stefanie; Horstkotte, Jan; Lee, Seungmin; Thormann, Michael; Knorr, Maike; El-Aouni, Chiraz; Boekstegers, Peter; Reichart, Bruno; Wenzel, Philip; Niemann, Heiner; Kupatt, Christian

2015-07-14

Heme oxygenase-1 (HO-1) is an inducible stress-responsive enzyme converting heme to bilirubin, carbon monoxide, and free iron, which exerts anti-inflammatory and antiapoptotic effects. Although efficient cardioprotection after HO-1 overexpression has been reported in rodents, its role in attenuating post-ischemic inflammation is unclear. This study assessed the efficacy of recombinant adenoassociated virus (rAAV)-encoding human heme oxygenase-1 (hHO-1) in attenuating post-ischemic inflammation in a murine and a porcine ischemia/reperfusion model. Murine ischemia was induced by 45 min of left anterior descending occlusion, followed by 24 h of reperfusion and functional as well as fluorescent-activated cell sorting analysis. Porcine hearts were subjected to 60 min of ischemia and 24h of reperfusion before hemodynamic and histologic analyses were performed. Human microvascular endothelial cells transfected with hHO-1 displayed an attenuated interleukin-6 and intercellular adhesion molecule 1 expression, resulting in reduced monocytic THP-1 cell recruitment in vitro. In murine left anterior descending occlusion and reperfusion, the post-ischemic influx of CD45(+) leukocytes, Ly-6G(+) neutrophils, and Ly-6C(high) monocytes was further exacerbated in HO-1-deficient hearts and reversed by rAAV.hHO-1 treatment. Conversely, in our porcine model of ischemia, the post-ischemic influx of myeloperoxidase-positive neutrophils and CD14(+) monocytes was reduced by 49% and 87% after rAAV.hHO-1 transduction, similar to hHO-1 transgenic pigs. Functionally, rAAV.hHO-1 and hHO-1 transgenic left ventricles displayed a smaller loss of ejection fraction than control animals. Whereas HO-1 deficiency exacerbates post-ischemic cardiac inflammation in mice, hHO-1 gene therapy attenuates inflammation after ischemia and reperfusion in murine and porcine hearts. Regional hHO-1 gene therapy provides cardioprotection in a pre-clinical porcine ischemia/reperfusion model. Copyright © 2015 American

The orbital ground state of the azide-substrate complex of human heme oxygenase is an indicator of distal H-bonding: Implications for the enzyme mechanism‡

Science.gov (United States)

Ogura, Hiroshi; Evans, John P.; Peng, Dungeng; Satterlee, James D.; de Montellano, Paul R. Ortiz; Mar, Gerd N. La

2009-01-01

The active site electronic structure of the azide complex of substrate-bound human heme oxygenase-1, (hHO) has been investigated by 1H NMR spectroscopy to shed light on the orbital/spin ground state as an indicator of the unique distal pocket environment of the enzyme. 2D 1H NMR assignments of the substrate and substrate-contact residue signals reveal a pattern of substrate methyl contact shifts, that places the lone iron π-spin in the dxz orbital, rather than the dyz orbital found in the cyanide complex. Comparison of iron spin relaxivity, magnetic anisotropy and magnetic susceptibilities argues for a low-spin, (dxy)2(dyz,dxz)3, ground state in both azide and cyanide complexes. The switch from singly-occupied dyz for the cyanide to dxz for the azide complex of hHO is shown to be consistent with the orbital hole determined by the azide π-plane in the latter complex, which is ∼90° in-plane rotated from that of the imidazole π-plane. The induction of the altered orbital ground state in the azide relative to the cyanide hHO complex, as well as the mean low-field bias of methyl hyperfine shifts and their paramagnetic relaxivity relative to those in globins, indicate that azide exerts a stronger ligand field in hHO than in the globins, or that the distal H-bonding to azide is weaker in hHO than in globins. The Asp140 → Ala hHO mutant that abolishes activity retains the unusual WT azide complex spin/orbital ground state. The relevance of our findings for other HO complexes and the HO mechanism is discussed. PMID:19243105

Astroglia overexpressing heme oxygenase-1 predispose co-cultured PC12 cells to oxidative injury.

Science.gov (United States)

Song, Linyang; Song, Wei; Schipper, Hyman M

2007-08-01

The mechanisms responsible for the progressive degeneration of dopaminergic neurons and pathologic iron deposition in the substantia nigra pars compacta of patients with Parkinson's disease (PD) remain unclear. Heme oxygenase-1 (HO-1), the rate-limiting enzyme in the oxidative degradation of heme to ferrous iron, carbon monoxide, and biliverdin, is upregulated in affected PD astroglia and may contribute to abnormal mitochondrial iron sequestration in these cells. To determine whether glial HO-1 hyper-expression is toxic to neuronal compartments, we co-cultured dopaminergic PC12 cells atop monolayers of human (h) HO-1 transfected, sham-transfected, or non-transfected primary rat astroglia. We observed that PC12 cells grown atop hHO-1 transfected astrocytes, but not the astroglia themselves, were significantly more susceptible to dopamine (1 microM) + H(2)O(2) (1 microM)-induced death (assessed by nuclear ethidium monoazide bromide staining and anti-tyrosine hydroxylase immunofluorescence microscopy) relative to control preparations. In the experimental group, PC12 cell death was attenuated significantly by the administration of the HO inhibitor, SnMP (1.5 microM), the antioxidant, ascorbate (200 microM), or the iron chelators, deferoxamine (400 microM), and phenanthroline (100 microM). Exposure to conditioned media derived from HO-1 transfected astrocytes also augmented PC12 cell killing in response to dopamine (1 microM) + H(2)O(2) (1 microM) relative to control media. In PD brain, overexpression of HO-1 in nigral astroglia and accompanying iron liberation may facilitate the bioactivation of dopamine to neurotoxic free radical intermediates and predispose nearby neuronal constituents to oxidative damage. (c) 2007 Wiley-Liss, Inc.

Dose rate effect on micronuclei induction in human blood lymphocytes exposed to single pulse and multiple pulses of electrons.

Science.gov (United States)

Acharya, Santhosh; Bhat, N N; Joseph, Praveen; Sanjeev, Ganesh; Sreedevi, B; Narayana, Y

2011-05-01

The effects of single pulses and multiple pulses of 7 MV electrons on micronuclei (MN) induction in cytokinesis-blocked human peripheral blood lymphocytes (PBLs) were investigated over a wide range of dose rates per pulse (instantaneous dose rate). PBLs were exposed to graded doses of 2, 3, 4, 6, and 8 Gy of single electron pulses of varying pulse widths at different dose rates per pulse, ranging from 1 × 10(6) Gy s(-1) to 3.2 × 10(8) Gy s(-1). Different dose rates per pulse were achieved by changing the dose per electron pulse by adjusting the beam current and pulse width. MN yields per unit absorbed dose after irradiation with single electron pulses were compared with those of multiple pulses of electrons. A significant decrease in the MN yield with increasing dose rates per pulse was observed, when dose was delivered by a single electron pulse. However, no reduction in the MN yield was observed when dose was delivered by multiple pulses of electrons. The decrease in the yield at high dose rates per pulse suggests possible radical recombination, which leads to decreased biological damage. Cellular response to the presence of very large numbers of chromosomal breaks may also alter the damage.

Polymorphisms in the Haem Oxygenase-1 promoter are not associated with severity of Plasmodium falciparum malaria in Ghanaian children.

Science.gov (United States)

Hansson, Helle H; Maretty, Lasse; Balle, Christina; Goka, Bamenla Q; Luzon, Elisa; Nkrumah, Francis N; Schousboe, Mette L; Rodrigues, Onike P; Bygbjerg, Ib Christian; Kurtzhals, Jørgen A L; Alifrangis, Michael; Hempel, Casper

2015-04-11

Haem oxygenase-1 (HO-1) catabolizes haem and has both cytotoxic and cytoprotective effects. Polymorphisms in the promoter of the Haem oxygenase-1 (HMOX1) gene encoding HO-1 have been associated with several diseases including severe malaria. The objective of this study was to determine the allele and genotype frequencies of two single nucleotide polymorphisms; A(-413)T and G(-1135)A, and a (GT)n repeat length polymorphism in the HMOX1 promoter in paediatric malaria patients and controls to determine possible associations with malaria disease severity. Study participants were Ghanaian children (n=296) admitted to the emergency room at the Department of Child Health, Korle-Bu Teaching Hospital, Accra, Ghana during the malaria season from June to August in 1995, 1996 and 1997, classified as having uncomplicated malaria (n=101) or severe malaria (n=195; defined as severe anaemia (n=63) or cerebral malaria (n=132)). Furthermore, 287 individuals without a detectable Plasmodium infection or asymptomatic carriers of the parasite were enrolled as controls. Blood samples from participants were extracted for DNA and allele and genotype frequencies were determined with allele-specific PCR, restriction fragment length analysis and microsatellite analysis. The number of (GT)n repeats in the study participants varied between 21 and 46 with the majority of alleles having lengths of 26 (8.1%), 29/30 (13.2/17.9%) and 39/40 (8.0/13.8%) repeats, and was categorized into short, medium and long repeats. The (-413)T allele was very common (69.8%), while the (-1135)A allele was present in only 17.4% of the Ghanaian population. The G(-1135)A locus was excluded from further analysis after failing the Hardy-Weinberg equilibrium test. No significant differences in allele or genotype distribution of the A(-413)T and (GT)n repeat polymorphisms were found between the controls and the malaria patients, or between the disease groups, for any of the analysed polymorphisms and no associations with

Novel bacterial sulfur oxygenase reductases from bioreactors treating gold-bearing concentrates

DEFF Research Database (Denmark)

Chen, Z-W; Liu, Y-Y; Wu, J-F

2007-01-01

The microbial community and sulfur oxygenase reductases of metagenomic DNA from bioreactors treating gold-bearing concentrates were studied by 16S rRNA library, real-time polymerase chain reaction (RT-PCR), conventional cultivation, and molecular cloning. Results indicated that major bacterial......) of bacteria and archaea were 4.59 x 10(9) and 6.68 x 10(5), respectively. Bacterial strains representing Acidithiobacillus, Leptospirillum, and Sulfobacillus were isolated from the bioreactors. To study sulfur oxidation in the reactors, pairs of new PCR primers were designed for the detection of sulfur...... oxygenase reductase (SOR) genes. Three sor-like genes, namely, sor (Fx), sor (SA), and sor (SB) were identified from metagenomic DNAs of the bioreactors. The sor (Fx) is an inactivated SOR gene and is identical to the pseudo-SOR gene of Ferroplasma acidarmanus. The sor (SA) and sor (SB) showed...

A model for the catabolism of rhizopine in Rhizobium leguminosarum involves a ferredoxin oxygenase complex and the inositol degradative pathway.

Science.gov (United States)

Bahar, M; de Majnik, J; Wexler, M; Fry, J; Poole, P S; Murphy, P J

1998-11-01

Rhizopines are nodule-specific compounds that confer an intraspecies competitive nodulation advantage to strains that can catabolize them. The rhizopine (3-O-methyl-scyllo-inosamine, 3-O-MSI) catabolic moc gene cluster mocCABRDE(F) in Rhizobium leguminosarum bv. viciae strain 1a is located on the Sym plasmid. MocCABR are homologous to the mocCABR gene products from Sinorhizobium meliloti. MocD and MocE contain motifs corresponding to a TOL-like oxygenase and a [2Fe-2S] Rieske-like ferredoxin, respectively. The mocF gene encodes a ferredoxin reductase that would complete the oxygenase system, but is not essential for rhizopine catabolism. We propose a rhizopine catabolic model whereby MocB transports rhizopine into the cell and MocDE and MocF (or a similar protein elsewhere in the genome), under the regulation of MocR, act in concert to form a ferredoxin oxygenase system that demethylates 3-O-MSI to form scyllo-inosamine (SI). MocA, an NAD(H)-dependent dehydrogenase, and MocC continue the catabolic process. Compounds formed then enter the inositol catabolic pathway.

Effects of the novel anti-inflammatory compounds, N-[2-(cyclohexyloxy)-4-nitrophenyl] methanesulphonamide (NS-398) and 5-methanesulphonamido-6-(2,4-difluorothio-phenyl)-1-inda none (L-745,337), on the cyclo-oxygenase activity of human blood prostaglandin endoperoxide synthases.

Science.gov (United States)

Panara, M R; Greco, A; Santini, G; Sciulli, M G; Rotondo, M T; Padovano, R; di Giamberardino, M; Cipollone, F; Cuccurullo, F; Patrono, C

1995-11-01

1. We have evaluated the selectivity of ketoprofen and two novel nonsteroidal anti-inflammatory drugs, N-[2-(cyclohexyloxy)-4-nitrophenyl]methanesulphonamide (NS-398) and 5-methanesulphonamido-6-(2,4-difluorothiophenyl)-1-indano ne (L-745,337), in inhibiting the cyclo-oxygenase activity of prostaglandin endoperoxide synthase-2 (PGHS-2) vs PGHS-1 in human blood monocytes and platelets, respectively. 2. Heparinized whole blood samples were drawn from healthy volunteers pretreated with aspirin, 300 mg 48 h before sampling, to suppress the activity of platelet PGHS-1 and incubated at 37 degrees C for 24 h with increasing concentrations of the test compounds in the presence of lipopolysaccharide (LPS, 10 micrograms ml-1). Immunoreactive PGE2 levels were measured in plasma by a specific radioimmunoassay as an index of the cyclo-oxygenase activity of LPS-induced monocyte PGHS-2. 3. The effects of the same inhibitors on platelet PGHS-1 activity were assessed by allowing whole blood samples, drawn from the same subjects in aspirin-free periods, to clot at 37 degrees C for 1 h in the presence of the compounds and measuring immunoreactive thromboxane B2 (TXB2) levels in serum by a specific radioimmunoassay. 4. Under these experimental conditions, ketoprofen enantioselectively inhibited the cyclo-oxygenase activity of both PGHS-1 and PGHS-2 with equal potency (IC50 ratio: approx. 0.5 for both enantiomers), while L-745,337 and NS-398 achieved selective inhibition of monocyte PGHS-2 (IC50 ratio: > 150). L-745,337 and NS-398 did not affect LPS-induced monocyte PGHS-2 biosynthesis to any detectable extent. 5. We conclude that L-745,337 and NS-398 are selective inhibitors of the cyclo-oxygenase activity of human monocyte PGHS-2. These compounds may provide adequate tools to test the contribution of this novel pathway of arachidonate metabolism to human inflammatory disease.

Regulation of human heme oxygenase in endothelial cells by using sense and antisense retroviral constructs.

Science.gov (United States)

Quan, S; Yang, L; Abraham, N G; Kappas, A

2001-10-09

Our objective was to determine whether overexpression and underexpression of human heme oxygenase (HHO)-1 could be controlled on a long-term basis by introduction of the HO-1 gene in sense (S) and antisense (AS) orientation with an appropriate vector into endothelial cells. Retroviral vector (LXSN) containing viral long terminal repeat promoter-driven human HO-1 S (LSN-HHO-1) and LXSN vectors containing HHO-1 promoter (HOP)-controlled HHO-1 S and AS (LSN-HOP-HHO-1 and LSN-HOP-HHO-1-AS) sequences were constructed and used to transfect rat lung microvessel endothelial cells (RLMV cells) and human dermal microvessel endothelial cells (HMEC-1 cells). RLMV cells transduced with HHO-1 S expressed human HO-1 mRNA and HO-1 protein associated with elevation in total HO activity compared with nontransduced cells. Vector-mediated expression of HHO-1 S or AS under control of HOP resulted in effective production of HO-1 or blocked induction of endogenous human HO-1 in HMEC-1 cells, respectively. Overexpression of HO-1 AS was associated with a long-term decrease (45%) of endogenous HO-1 protein and an increase (167%) in unmetabolized exogenous heme in HMEC-1 cells. Carbon monoxide (CO) production in HO-1 S- or AS-transduced HMEC-1 cells after heme treatment was increased (159%) or decreased (50%), respectively, compared with nontransduced cells. HO-2 protein levels did not change. These findings demonstrate that HHO-1 S and AS retroviral constructs are functional in enhancing and reducing HO activity, respectively, and thus can be used to regulate cellular heme levels, the activity of heme-dependent enzymes, and the rate of heme catabolism to CO and bilirubin.

Heme oxygenase-1 protects endothelial cells from the toxicity of air pollutant chemicals

International Nuclear Information System (INIS)

Lawal, Akeem O.; Zhang, Min; Dittmar, Michael; Lulla, Aaron; Araujo, Jesus A.

2015-01-01

Diesel exhaust particles (DEPs) are a major component of diesel emissions, responsible for a large portion of their toxicity. In this study, we examined the toxic effects of DEPs on endothelial cells and the role of DEP-induced heme oxygenase-1 (HO-1) expression. Human microvascular endothelial cells (HMECs) were treated with an organic extract of DEPs from an automobile engine (A-DEP) or a forklift engine (F-DEP) for 1 and 4 h. ROS generation, cell viability, lactate dehydrogenase leakage, expression of HO-1, inflammatory genes, cell adhesion molecules and unfolded protein respone (UPR) gene were assessed. HO-1 expression and/or activity were inhibited by siRNA or tin protoporphyrin (Sn PPIX) and enhanced by an expression plasmid or cobalt protoporphyrin (CoPPIX). Exposure to 25 μg/ml of A-DEP and F-DEP significantly induced ROS production, cellular toxicity and greater levels of inflammatory and cellular adhesion molecules but to a different degree. Inhibition of HO-1 enzymatic activity with SnPPIX and silencing of the HO-1 gene by siRNA enhanced DEP-induced ROS production, further decreased cell viability and increased expression of inflammatory and cell adhesion molecules. On the other hand, overexpression of the HO-1 gene by a pcDNA 3.1D/V5-HO-1 plasmid significantly mitigated ROS production, increased cell survival and decreased the expression of inflammatory genes. HO-1 expression protected HMECs from DEP-induced prooxidative and proinflammatory effects. Modulation of HO-1 expression could potentially serve as a therapeutic target in an attempt to inhibit the cardiovascular effects of ambient PM. - Highlights: • We examined the role of HO-1 expression on diesel exhaust particle (DEP) in endothelial cells. • DEPs exert cytotoxic and inflammatory effects on human microvascular endothelial cells (HMECs). • DEPs induce HO-1 expression in HMECs. • HO-1 protects against the oxidative stress induced by DEps. • HO-1 attenuates the proinflammatory effects

Heme oxygenase-1 protects endothelial cells from the toxicity of air pollutant chemicals

Energy Technology Data Exchange (ETDEWEB)

Lawal, Akeem O.; Zhang, Min; Dittmar, Michael [Division of Cardiology, David Geffen School of Medicine, University of California, Los Angeles, 10833 Le Conte Avenue, CHS 43-264, Los Angeles, CA 90095 (United States); Lulla, Aaron [Division of Cardiology, David Geffen School of Medicine, University of California, Los Angeles, 10833 Le Conte Avenue, CHS 43-264, Los Angeles, CA 90095 (United States); Molecular Toxicology Interdepartmental Program, University of California, Los Angeles (United States); Araujo, Jesus A., E-mail: JAraujo@mednet.ucla.edu [Division of Cardiology, David Geffen School of Medicine, University of California, Los Angeles, 10833 Le Conte Avenue, CHS 43-264, Los Angeles, CA 90095 (United States); Molecular Toxicology Interdepartmental Program, University of California, Los Angeles (United States); Molecular Biology Institute, University of California, Los Angeles (United States)

2015-05-01

Diesel exhaust particles (DEPs) are a major component of diesel emissions, responsible for a large portion of their toxicity. In this study, we examined the toxic effects of DEPs on endothelial cells and the role of DEP-induced heme oxygenase-1 (HO-1) expression. Human microvascular endothelial cells (HMECs) were treated with an organic extract of DEPs from an automobile engine (A-DEP) or a forklift engine (F-DEP) for 1 and 4 h. ROS generation, cell viability, lactate dehydrogenase leakage, expression of HO-1, inflammatory genes, cell adhesion molecules and unfolded protein respone (UPR) gene were assessed. HO-1 expression and/or activity were inhibited by siRNA or tin protoporphyrin (Sn PPIX) and enhanced by an expression plasmid or cobalt protoporphyrin (CoPPIX). Exposure to 25 μg/ml of A-DEP and F-DEP significantly induced ROS production, cellular toxicity and greater levels of inflammatory and cellular adhesion molecules but to a different degree. Inhibition of HO-1 enzymatic activity with SnPPIX and silencing of the HO-1 gene by siRNA enhanced DEP-induced ROS production, further decreased cell viability and increased expression of inflammatory and cell adhesion molecules. On the other hand, overexpression of the HO-1 gene by a pcDNA 3.1D/V5-HO-1 plasmid significantly mitigated ROS production, increased cell survival and decreased the expression of inflammatory genes. HO-1 expression protected HMECs from DEP-induced prooxidative and proinflammatory effects. Modulation of HO-1 expression could potentially serve as a therapeutic target in an attempt to inhibit the cardiovascular effects of ambient PM. - Highlights: • We examined the role of HO-1 expression on diesel exhaust particle (DEP) in endothelial cells. • DEPs exert cytotoxic and inflammatory effects on human microvascular endothelial cells (HMECs). • DEPs induce HO-1 expression in HMECs. • HO-1 protects against the oxidative stress induced by DEps. • HO-1 attenuates the proinflammatory effects

Cysteine-independent activation/inhibition of heme oxygenase-2

Directory of Open Access Journals (Sweden)

Dragic Vukomanovic

2016-01-01

Full Text Available Reactive thiols of cysteine (cys residues in proteins play a key role in transforming chemical reactivity into a biological response. The heme oxygenase-2 (HO-2 isozyme contains two cys residues that have been implicated in binding of heme and also the regulation of its activity. In this paper, we address the question of a role for cys residues for the HO-2 inhibitors or activators designed in our laboratory. We tested the activity of full length recombinant human heme oxygenase-2 (FL-hHO-2 and its analog in which cys265 and cys282 were both replaced by alanine to determine the effect on activation by menadione (MD and inhibition by QC-2350. Similar inhibition by QC-2350 and almost identical activation by MD was observed for both recombinant FL-hHO-2s. Our findings are interpreted to mean that thiols of FL-hHO-2s are not involved in HO-2 activation or inhibition by the compounds that have been designed and identified by us. Activation or inhibition of HO-2 by our compounds should be attributed to a mechanism other than altering binding affinity of HO-2 for heme through cys265 and cys282.

Cysteine-independent activation/inhibition of heme oxygenase-2.

Science.gov (United States)

Vukomanovic, Dragic; Rahman, Mona N; Maines, Mahin D; Ozolinš, Terence Rs; Szarek, Walter A; Jia, Zongchao; Nakatsu, Kanji

2016-03-01

Reactive thiols of cysteine (cys) residues in proteins play a key role in transforming chemical reactivity into a biological response. The heme oxygenase-2 (HO-2) isozyme contains two cys residues that have been implicated in binding of heme and also the regulation of its activity. In this paper, we address the question of a role for cys residues for the HO-2 inhibitors or activators designed in our laboratory. We tested the activity of full length recombinant human heme oxygenase-2 (FL-hHO-2) and its analog in which cys265 and cys282 were both replaced by alanine to determine the effect on activation by menadione (MD) and inhibition by QC-2350. Similar inhibition by QC-2350 and almost identical activation by MD was observed for both recombinant FL-hHO-2s. Our findings are interpreted to mean that thiols of FL-hHO-2s are not involved in HO-2 activation or inhibition by the compounds that have been designed and identified by us. Activation or inhibition of HO-2 by our compounds should be attributed to a mechanism other than altering binding affinity of HO-2 for heme through cys265 and cys282.

Epigallocatechin Gallate Attenuates Proliferation and Oxidative Stress in Human Vascular Smooth Muscle Cells Induced by Interleukin-1β via Heme Oxygenase-1

Directory of Open Access Journals (Sweden)

Po-Len Liu

2014-01-01

Full Text Available Proliferation of vascular smooth muscle cells (VSMCs triggered by inflammatory stimuli and oxidative stress contributes importantly to atherogenesis. The association of green tea consumption with cardiovascular protection has been well documented in epidemiological observations, however, the underlying mechanisms remain unclear. This study aimed to elucidate the effects of the most active green tea catechin derivative, (−-epigallocatechin-3-gallate (EGCG, in human aortic smooth muscle cells (HASMCs, focusing particularly on the role of a potent anti-inflammatory and antioxidative enzyme heme oxygenase-1 (HO-1. We found that pretreatment of EGCG dose- and time-dependently induced HO-1 protein levels in HASMCs. EGCG inhibited interleukin- (IL-1β-induced HASMC proliferation and oxidative stress in a dose-dependent manner. The HO-1 inducer CoPPIX decreased IL-1β-induced cell proliferation, whereas the HO-1 enzyme inhibitor ZnPPIX significantly reversed EGCG-caused growth inhibition in IL-1β-treated HASMCs. At the molecular level, EGCG treatment significantly activated nuclear factor erythroid-2-related factor (Nrf2 transcription activities. These results suggest that EGCG might serve as a complementary and alternative medicine in the treatment of these pathologies by inducing HO-1 expression and subsequently decreasing VSMC proliferation.

Transduction of PEP-1-heme oxygenase-1 into insulin-producing INS-1 cells protects them against cytokine-induced cell death

Energy Technology Data Exchange (ETDEWEB)

Lee, Su Jin; Kang, Hyung Kyung [Department of Physiology, College of Medicine, Hallym University, Chunchon 200-702 (Korea, Republic of); Song, Dong Keun [Department of Pharmacology, College of Medicine, Hallym University, Chunchon 200-702 (Korea, Republic of); Eum, Won Sik; Park, Jinseu [Department of Biomedical Science and Research Institute of Bioscience and Biotechnology, Hallym University, Chunchon 200-702 (Korea, Republic of); Choi, Soo Young, E-mail: sychoi@hallym.ac.kr [Department of Biomedical Science and Research Institute of Bioscience and Biotechnology, Hallym University, Chunchon 200-702 (Korea, Republic of); Kwon, Hyeok Yil, E-mail: hykwon@hallym.ac.kr [Department of Physiology, College of Medicine, Hallym University, Chunchon 200-702 (Korea, Republic of)

2015-06-05

Pro-inflammatory cytokines play a crucial role in the destruction of pancreatic β-cells, thereby triggering the development of autoimmune diabetes mellitus. We recently developed a cell-permeable fusion protein, PEP-1-heme oxygenase-1 (PEP-1-HO-1) and investigated the anti-inflammatory effects in macrophage cells. In this study, we transduced PEP-1-HO-1 into INS-1 insulinoma cells and examined its protective effect against cytokine-induced cell death. PEP-1-HO-1 was successfully delivered into INS-1 cells in time- and dose-dependent manner and was maintained within the cells for at least 48 h. Pre-treatment with PEP-1-HO-1 increased the survival of INS-1 cells exposed to cytokine mixture (IL-1β, IFN-γ, and TNF-α) in a dose-dependent manner. PEP-1-HO-1 markedly decreased cytokine-induced production of reactive oxygen species (ROS), nitric oxide (NO), and malondialdehyde (MDA). These protective effects of PEP-1-HO-1 against cytokines were correlated with the changes in the levels of signaling mediators of inflammation (iNOS and COX-2) and cell apoptosis/survival (Bcl-2, Bax, caspase-3, PARP, JNK, and Akt). These results showed that the transduced PEP-1-HO-1 efficiently prevented cytokine-induced cell death of INS-1 cells by alleviating oxidative/nitrosative stresses and inflammation. Further, these results suggested that PEP-1-mediated HO-1 transduction may be a potential therapeutic strategy to prevent β-cell destruction in patients with autoimmune diabetes mellitus. - Highlights: • We showed that PEP-1-HO-1 was efficiently delivered into INS-1 cells. • Transduced PEP-1-HO-1 exerted a protective effect against cytokine-induced cell death. • Transduced PEP-1-HO-1 inhibited cytokine-induced ROS and NO accumulation. • PEP-1-HO-1 suppressed cytokine-induced expression of iNOS, COX-2, and Bax. • PEP-1-HO-1 transduction may be an efficient tool to prevent β-cell destruction.

Transduction of PEP-1-heme oxygenase-1 into insulin-producing INS-1 cells protects them against cytokine-induced cell death

International Nuclear Information System (INIS)

Lee, Su Jin; Kang, Hyung Kyung; Song, Dong Keun; Eum, Won Sik; Park, Jinseu; Choi, Soo Young; Kwon, Hyeok Yil

2015-01-01

Pro-inflammatory cytokines play a crucial role in the destruction of pancreatic β-cells, thereby triggering the development of autoimmune diabetes mellitus. We recently developed a cell-permeable fusion protein, PEP-1-heme oxygenase-1 (PEP-1-HO-1) and investigated the anti-inflammatory effects in macrophage cells. In this study, we transduced PEP-1-HO-1 into INS-1 insulinoma cells and examined its protective effect against cytokine-induced cell death. PEP-1-HO-1 was successfully delivered into INS-1 cells in time- and dose-dependent manner and was maintained within the cells for at least 48 h. Pre-treatment with PEP-1-HO-1 increased the survival of INS-1 cells exposed to cytokine mixture (IL-1β, IFN-γ, and TNF-α) in a dose-dependent manner. PEP-1-HO-1 markedly decreased cytokine-induced production of reactive oxygen species (ROS), nitric oxide (NO), and malondialdehyde (MDA). These protective effects of PEP-1-HO-1 against cytokines were correlated with the changes in the levels of signaling mediators of inflammation (iNOS and COX-2) and cell apoptosis/survival (Bcl-2, Bax, caspase-3, PARP, JNK, and Akt). These results showed that the transduced PEP-1-HO-1 efficiently prevented cytokine-induced cell death of INS-1 cells by alleviating oxidative/nitrosative stresses and inflammation. Further, these results suggested that PEP-1-mediated HO-1 transduction may be a potential therapeutic strategy to prevent β-cell destruction in patients with autoimmune diabetes mellitus. - Highlights: • We showed that PEP-1-HO-1 was efficiently delivered into INS-1 cells. • Transduced PEP-1-HO-1 exerted a protective effect against cytokine-induced cell death. • Transduced PEP-1-HO-1 inhibited cytokine-induced ROS and NO accumulation. • PEP-1-HO-1 suppressed cytokine-induced expression of iNOS, COX-2, and Bax. • PEP-1-HO-1 transduction may be an efficient tool to prevent β-cell destruction

Expression of nerve growth factor and heme oxygenase-1 predict poor survival of breast carcinoma patients

International Nuclear Information System (INIS)

Noh, Sang Jae; Chung, Myoung Ja; Moon, Woo Sung; Kang, Myoung Jae; Jang, Kyu Yun; Bae, Jun Sang; Jamiyandorj, Urangoo; Park, Ho Sung; Kwon, Keun Sang; Jung, Sung Hoo; Youn, Hyun Jo; Lee, Ho; Park, Byung-Hyun

2013-01-01

Nerve growth factor (NGF) is a neurotrophin and has been suggested to induce heme oxygenase-1 (HO1) expression. Although the role of HO1 in tumorigenesis remains controversial, recent evidence suggests NGF and HO1 as tumor-progressing factors. However, the correlative role of NGF and HO1 and their prognostic impact in breast carcinoma is unknown. We investigated the expression and prognostic significance of the expression of NGF and HO1 in 145 cases of breast carcinoma. Immunohistochemical expression of NGF and HO1 was observed in 31% and 49% of breast carcinoma, respectively. The expression of NGF and HO1 significantly associated with each other, and both have a significant association with histologic grade, HER2 expression, and latent distant metastasis. The expression of NGF and HO1 predicted shorter overall survival of breast carcinoma by univariate and multivariate analysis. NGF expression was an independent prognostic indicator for relapse-free survival by multivariate analysis. The combined expression pattern of NGF and HO1 was also an independent prognostic indicator of overall survival and relapse-free survival. The patients with tumors expressing NGF had the shortest survival and the patients with tumor, which did not express NGF or HO1 showed the longest survival time. This study has demonstrated that individual expression of NGF or HO1, and the combined NGF/HO1 expression pattern could be prognostic indicators for breast carcinoma patients

Active site architecture of a sugar N-oxygenase.

Science.gov (United States)

Thoden, James B; Branch, Megan C; Zimmer, Alex L; Bruender, Nathan A; Holden, Hazel M

2013-05-14

KijD3 is a flavin-dependent N-oxygenase implicated in the formation of the nitro-containing sugar d-kijanose, found attached to the antibiotic kijanimicin. For this investigation, the structure of KijD3 in complex with FMN and its dTDP-sugar substrate was solved to 2.1 Å resolution. In contrast to the apoenzyme structure, the C-terminus of the protein becomes ordered and projects into the active site cleft [Bruender, N. A., Thoden, J. B., and Holden, H. M. (2010) Biochemistry 49, 3517-3524]. The amino group of the dTDP-aminosugar that is oxidized is located 4.9 Å from C4a of the flavin ring. The model provides a molecular basis for understanding the manner in which KijD3 catalyzes its unusual chemical transformation.

Andrographolide induces Nrf2 and heme oxygenase 1 in astrocytes by activating p38 MAPK and ERK.

Science.gov (United States)

Wong, Siew Ying; Tan, Michelle G K; Wong, Peter T H; Herr, Deron R; Lai, Mitchell K P

2016-09-23

Andrographolide is the major labdane diterpenoid originally isolated from Andrographis paniculata and has been shown to have anti-inflammatory and antioxidative effects. However, there is a dearth of studies on the potential therapeutic utility of andrographolide in neuroinflammatory conditions. Here, we aimed to investigate the mechanisms underlying andrographolide's effect on the expression of anti-inflammatory and antioxidant heme oxygenase-1 (HO-1) in primary astrocytes. Measurements of the effects of andrograholide on antioxidant HO-1 and its transcription factor, Nrf2, include gene expression, protein turnover, and activation of putative signaling regulators. Andrographolide potently activated Nrf2 and also upregulated HO-1 expression in primary astrocytes. Andrographolide's effects on Nrf2 seemed to be biphasic, with acute (within 1 h) reductions in Nrf2 ubiquitination efficiency and turnover rate, followed by upregulation of Nrf2 mRNA between 8 and 24 h. The acute regulation of Nrf2 by andrographolide seemed to be independent of Keap1 and partly mediated by p38 MAPK and ERK signaling. These data provide further insights into the mechanisms underlying andrographolide's effects on astrocyte-mediated antioxidant, and anti-inflammatory responses and support the further assessment of andrographolide as a potential therapeutic for neurological conditions in which oxidative stress and neuroinflammation are implicated.

Antioxidant mechanism of heme oxygenase-1 involves an increase in superoxide dismutase and catalase in experimental diabetes.

Science.gov (United States)

Turkseven, Saadet; Kruger, Adam; Mingone, Christopher J; Kaminski, Pawel; Inaba, Muneo; Rodella, Luigi F; Ikehara, Susumu; Wolin, Michael S; Abraham, Nader G

2005-08-01

Increased heme oxygenase (HO)-1 activity attenuates endothelial cell apoptosis and decreases superoxide anion (O2-) formation in experimental diabetes by unknown mechanisms. We examined the effect of HO-1 protein and HO activity on extracellular SOD (EC-SOD), catalase, O2-, inducible nitric oxide synthase (iNOS), and endothelial nitric oxide synthase (eNOS) levels and vascular responses to ACh in control and diabetic rats. Vascular EC-SOD and plasma catalase activities were significantly reduced in diabetic compared with nondiabetic rats (P inhibitor of HO-1 activity, decreased EC-SOD protein. Increased HO-1 activity in diabetic rats was associated with a decrease in iNOS but increases in eNOS and plasma catalase activity. On the other hand, aortic ring segments from diabetic rats exhibited a significant reduction in vascular relaxation to ACh, which was reversed with cobalt protoporphyrin treatment. These data demonstrate that an increase in HO-1 protein and activity, i.e., CO and bilirubin production, in diabetic rats brings about a robust increase in EC-SOD, catalase, and eNOS with a concomitant increase in endothelial relaxation and a decrease in O2-. These observations in experimental diabetes suggest that the vascular cytoprotective mechanism of HO-1 against oxidative stress requires an increase in EC-SOD and catalase.

Resistorless Electronically Tunable Grounded Inductance Simulator Design

OpenAIRE

Herencsár, Norbert; Kartci, Aslihan

2017-01-01

A new realization of grounded lossless positive inductance simulator (PIS) using simple inverting voltage buffer and unity-gain current follower/inverter (CF±) is reported. Considering the input intrinsic resistance of CF± as useful active parameter, the proposed PIS can be considered as resistorless circuit and it only employs in total 16 Metal-Oxide-Semiconductor (MOS) transistors and a grounded capacitor. The resulting equivalent inductance value of the proposed simulator can be adjusted v...

Light Intensity-Dependent Modulation of Chlorophyll b Biosynthesis and Photosynthesis by Overexpression of Chlorophyllide a Oxygenase in Tobacco1[C][OA

Science.gov (United States)

Biswal, Ajaya K.; Pattanayak, Gopal K.; Pandey, Shiv S.; Leelavathi, Sadhu; Reddy, Vanga S.; Govindjee; Tripathy, Baishnab C.

2012-01-01

Chlorophyll b is synthesized by the oxidation of a methyl group on the B ring of a tetrapyrrole molecule to a formyl group by chlorophyllide a oxygenase (CAO). The full-length CAO from Arabidopsis (Arabidopsis thaliana) was overexpressed in tobacco (Nicotiana tabacum) that grows well at light intensities much higher than those tolerated by Arabidopsis. This resulted in an increased synthesis of glutamate semialdehyde, 5-aminolevulinic acid, magnesium-porphyrins, and chlorophylls. Overexpression of CAO resulted in increased chlorophyll b synthesis and a decreased chlorophyll a/b ratio in low light-grown as well as high light-grown tobacco plants; this effect, however, was more pronounced in high light. The increased potential of the protochlorophyllide oxidoreductase activity and chlorophyll biosynthesis compensated for the usual loss of chlorophylls in high light. Increased chlorophyll b synthesis in CAO-overexpressed plants was accompanied not only by an increased abundance of light-harvesting chlorophyll proteins but also of other proteins of the electron transport chain, which led to an increase in the capture of light as well as enhanced (40%–80%) electron transport rates of photosystems I and II at both limiting and saturating light intensities. Although the quantum yield of carbon dioxide fixation remained unchanged, the light-saturated photosynthetic carbon assimilation, starch content, and dry matter accumulation increased in CAO-overexpressed plants grown in both low- and high-light regimes. These results demonstrate that controlled up-regulation of chlorophyll b biosynthesis comodulates the expression of several thylakoid membrane proteins that increase both the antenna size and the electron transport rates and enhance carbon dioxide assimilation, starch content, and dry matter accumulation. PMID:22419827

The heme-heme oxygenase system: a molecular switch in wound healing.

NARCIS (Netherlands)

Wagener, F.A.D.T.G.; Beurden, H.E. van; Hoff, J.W. Von den; Adema, G.J.; Figdor, C.G.

2003-01-01

When cells are injured they release their contents, resulting in a local accumulation of free heme proteins and heme. Here, we investigated the involvement of heme and its degrading enzyme heme oxygenase (HO) in the inflammatory process during wound healing. We observed that heme directly

The binding sites on human heme oxygenase-1 for cytochrome p450 reductase and biliverdin reductase.

Science.gov (United States)

Wang, Jinling; de Montellano, Paul R Ortiz

2003-05-30

Human heme oxygenase-1 (hHO-1) catalyzes the NADPH-cytochrome P450 reductase-dependent oxidation of heme to biliverdin, CO, and free iron. The biliverdin is subsequently reduced to bilirubin by biliverdin reductase. Earlier kinetic studies suggested that biliverdin reductase facilitates the release of biliverdin from hHO-1 (Liu, Y., and Ortiz de Montellano, P. R. (2000) J. Biol. Chem. 275, 5297-5307). We have investigated the binding of P450 reductase and biliverdin reductase to truncated, soluble hHO-1 by fluorescence resonance energy transfer and site-specific mutagenesis. P450 reductase and biliverdin reductase bind to truncated hHO-1 with Kd = 0.4 +/- 0.1 and 0.2 +/- 0.1 microm, respectively. FRET experiments indicate that biliverdin reductase and P450 reductase compete for binding to truncated hHO-1. Mutation of surface ionic residues shows that hHO-1 residues Lys18, Lys22, Lys179, Arg183, Arg198, Glu19, Glu127, and Glu190 contribute to the binding of cytochrome P450 reductase. The mutagenesis results and a computational analysis of the protein surfaces partially define the binding site for P450 reductase. An overlapping binding site including Lys18, Lys22, Lys179, Arg183, and Arg185 is similarly defined for biliverdin reductase. These results confirm the binding of biliverdin reductase to hHO-1 and define binding sites of the two reductases.

Characterization and evaluation of catechol oxygenases by twelve bacteria, isolated from oil contaminated soils in Malaysia

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Arezoo Tavakoli

2017-01-01

Full Text Available Introduction: Catechol is a common intermediate compound in aromatic degradation process. Some microorganisms have this potentiality to degrade aromatic hydrocarbons by catechol dioxygenases to less toxic compounds with ability of entering the tricarboxylic acid cycle. In the present study, the catechol oxygenase activity was measured for 12 crude oil degrader bacteria. Materials and methods: Catechol oxygenase activity of two enzymes includes catechol 1, 2 dioxygenase and catechol 2, 3 dioxygenase were determined using spectrophotometer at 260 nm and 375 nm, respectively. Results: The highest enzyme activity for catechol 1, 2 dioxygenase by Bacillus cereus UKMP-6G was (0.07 U/mL and about catechol 2, 3 dioxygenase was 0.031 U/mL by Rhodococcus ruber UKMP-5M during the first minute of incubation. Catechol 1, 2 dioxygenase and catechol 2, 3 dioxygenase followed the ortho and meta pathway, respectively. Discussion and conclusion: The enzyme assay results showed that among 12 examined bacteria, only R. ruber UKMP-5M has the ability to use meta pathway for degradation and produce 2-hydroxymuconic acid. The other isolates use ortho pathway and create cis, cis-muconic acid.

Plasma heme oxygenase-1 concentration is elevated in individuals with type 2 diabetes mellitus.

Directory of Open Access Journals (Sweden)

Wei Bao

Full Text Available BACKGROUND: Circulating concentrations of heme oxygenase-1 (HO-1 have been recently reported to be elevated in several chronic disorders. However, no study has ever examined the association between circulating HO-1 concentrations and type 2 diabetes mellitus (T2DM. METHODS AND FINDINGS: 581 cases with newly-diagnosed T2DM (New-T2DM and 611 comparison controls were recruited in this two-phase case-control study, comprising 420 cases and 429 controls collected in the first phase study and 161 cases and 182 controls in the second phase replication study. Analyses, using both separated data and combined data from the two-phase studies, show that plasma HO-1 concentrations were significantly increased in New-T2DM cases compared to controls (P<0.001. Plasma HO-1 concentrations were significantly correlated with plasma glucose concentrations, HOMA-beta and HOMA-IR (P<0.001. After adjustment for age, sex, BMI and family history of diabetes, the ORs for New-T2DM in the highest quartile of plasma HO-1 concentrations, compared with the lowest, was 8.23 (95% CI 5.55-12.21; P for trend <0.001. The trend remained significant after additional adjustment for fasting plasma glucose/insulin, HOMA-beta/HOMA-IR, TC/TG, smoking, drinking and history of hypertension, and even in further stratification analysis by age, sex, BMI, smoking, drinking and history of hypertension. CONCLUSIONS: Elevated plasma HO-1 concentrations are associated with higher ORs for New-T2DM, which add more knowledge regarding the important role of oxidative stress in T2DM. More consequent studies were warranted to confirm the clinical utility of plasma HO-1, especially in diagnosis and prognosis of T2DM and its complications.

The effect of 111In radionuclide distance and auger electron energy on direct induction of DNA double-strand breaks: a Monte Carlo study using Geant4 toolkit.

Science.gov (United States)

Piroozfar, Behnaz; Raisali, Gholamreza; Alirezapour, Behrouz; Mirzaii, Mohammad

2018-04-01

In this study, the effect of 111 In position and Auger electron energy on direct induction of DSBs was investigated. The Geant4-DNA simulation toolkit was applied using a simple B-DNA form extracted from PDBlib library. First, the simulation was performed for electrons with energies of 111 In and equal emission probabilities to find the most effective electron energies. Then, 111 In Auger electrons' actual spectrum was considered and their contribution in DSB induction analysed. The results showed that the most effective electron energy is 183 eV, but due to the higher emission probability of 350 eV electrons, most of the DSBs were induced by the latter electrons. Also, it was observed that most of the DSBs are induced by electrons emitted within 4 nm of the central axis of the DNA and were mainly due to breaks with <4 base pairs distance in opposing strands. Whilst, when 111 In atoms are very close to the DNA, 1.3 DSBs have been obtained per decay of 111 In atoms. The results show that the most effective Auger electrons are the 350 eV electrons from 111 In atoms with <4 nm distance from the central axis of the DNA which induce ∼1.3 DSBs per decay when bound to the DNA. This value seems reasonable when compared with the reported experimental data.

The orbital ground state of the azide-substrate complex of human heme oxygenase is an indicator of distal H-bonding: implications for the enzyme mechanism.

Science.gov (United States)

Ogura, Hiroshi; Evans, John P; Peng, Dungeng; Satterlee, James D; Ortiz de Montellano, Paul R; La Mar, Gerd N

2009-04-14

The active site electronic structure of the azide complex of substrate-bound human heme oxygenase 1 (hHO) has been investigated by (1)H NMR spectroscopy to shed light on the orbital/spin ground state as an indicator of the unique distal pocket environment of the enzyme. Two-dimensional (1)H NMR assignments of the substrate and substrate-contact residue signals reveal a pattern of substrate methyl contact shifts that places the lone iron pi-spin in the d(xz) orbital, rather than the d(yz) orbital found in the cyanide complex. Comparison of iron spin relaxivity, magnetic anisotropy, and magnetic susceptibilities argues for a low-spin, (d(xy))(2)(d(yz),d(xz))(3), ground state in both azide and cyanide complexes. The switch from singly occupied d(yz) for the cyanide to d(xz) for the azide complex of hHO is shown to be consistent with the orbital hole determined by the azide pi-plane in the latter complex, which is approximately 90 degrees in-plane rotated from that of the imidazole pi-plane. The induction of the altered orbital ground state in the azide relative to the cyanide hHO complex, as well as the mean low-field bias of methyl hyperfine shifts and their paramagnetic relaxivity relative to those in globins, indicates that azide exerts a stronger ligand field in hHO than in the globins, or that the distal H-bonding to azide is weaker in hHO than in globins. The Asp140 --> Ala hHO mutant that abolishes activity retains the unusual WT azide complex spin/orbital ground state. The relevance of our findings for other HO complexes and the HO mechanism is discussed.

BTB and CNC homolog 1 (Bach1) deficiency ameliorates TNBS colitis in mice: role of M2 macrophages and heme oxygenase-1.

Science.gov (United States)

Harusato, Akihito; Naito, Yuji; Takagi, Tomohisa; Uchiyama, Kazuhiko; Mizushima, Katsura; Hirai, Yasuko; Higashimura, Yasuki; Katada, Kazuhiro; Handa, Osamu; Ishikawa, Takeshi; Yagi, Nobuaki; Kokura, Satoshi; Ichikawa, Hiroshi; Muto, Akihiko; Igarashi, Kazuhiko; Yoshikawa, Toshikazu

2013-01-01

BTB and CNC homolog 1 (Bach1) is a transcriptional repressor of heme oxygenase-1 (HO-1), which plays an important role in the protection of cells and tissues against acute and chronic inflammation. However, the role of Bach1 in the gastrointestinal mucosal defense system remains little understood. HO-1 supports the suppression of experimental colitis and localizes mainly in macrophages in colonic mucosa. This study was undertaken to elucidate the Bach1/HO-1 system's effects on the pathogenesis of experimental colitis. This study used C57BL/6 (wild-type) and homozygous Bach1-deficient C57BL/6 mice in which colonic damage was induced by the administration of an enema of 2,4,6-trinitrobenzene sulfonic acid (TNBS). Subsequently, they were evaluated macroscopically, histologically, and biochemically. Peritoneal macrophages from the respective mice were isolated and analyzed. Then, wild-type mice were injected with peritoneal macrophages from the respective mice. Acute colitis was induced similarly. TNBS-induced colitis was inhibited in Bach1-deficient mice. TNBS administration increased the expression of HO-1 messenger RNA and protein in colonic mucosa in Bach1-deficient mice. The expression of HO-1 mainly localized in F4/80-immunopositive and CD11b-immunopositive macrophages. Isolated peritoneal macrophages from Bach1-deficient mice highly expressed HO-1 and also manifested M2 macrophage markers, such as Arginase-1, Fizz-1, Ym1, and MRC1. Furthermore, TNBS-induced colitis was inhibited by the transfer of Bach1-deficient macrophages into wild-type mice. Deficiency of Bach1 ameliorated TNBS-induced colitis. Bach1-deficient macrophages played a key role in protection against colitis. Targeting of this mechanism is applicable to cell therapy for human inflammatory bowel disease.

Fructose during pregnancy provokes fetal oxidative stress: The key role of the placental heme oxygenase-1.

Science.gov (United States)

Rodrigo, Silvia; Rodríguez, Lourdes; Otero, Paola; Panadero, María I; García, Antonia; Barbas, Coral; Roglans, Núria; Ramos, Sonia; Goya, Luis; Laguna, Juan C; Álvarez-Millán, Juan J; Bocos, Carlos

2016-12-01

One of the features of metabolic syndrome caused by liquid fructose intake is an impairment of redox status. We have investigated whether maternal fructose ingestion modifies the redox status in pregnant rats and their fetuses. Fructose (10% wt/vol) in the drinking water of rats throughout gestation, leads to maternal hepatic oxidative stress. However, this change was also observed in glucose-fed rats and, in fact, both carbohydrates produced a decrease in antioxidant enzyme activity. Surprisingly, mothers fed carbohydrates displayed low plasma lipid oxidation. In contrast, fetuses from fructose-fed mothers showed elevated levels of plasma lipoperoxides versus fetuses from control or glucose-fed mothers. Interestingly, a clearly augmented oxidative stress was observed in placenta of fructose-fed mothers, accompanied by a lower expression of the transcription factor Nuclear factor-erythroid 2-related factor-2 (Nrf2) and its target gene, heme oxygenase-1 (HO-1), a potent antioxidant molecule. Moreover, histone deacetylase 3 (HDAC3) that has been proposed to upregulate HO-1 expression by stabilizing Nrf2, exhibited a diminished expression in placenta of fructose-supplemented mothers. Maternal fructose intake provoked an imbalanced redox status in placenta and a clear diminution of HO-1 expression, which could be responsible for the augmented oxidative stress found in their fetuses. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Potent heme-degrading action of antimony and antimony-containing parasiticidal agents.

Science.gov (United States)

Drummond, G S; Kappas, A

1981-02-01

The ability of antimony and antimony-containing parasiticidal agents to enhance the rate of heme degradation in liver and kidney was investigated. Trivalent antimony was shown to be an extremely potent inducer of heme oxygenase, the initial and rate-limiting enzyme in heme degradation, in both organs, whereas the pentavalent form was a weak inducer of this enzyme. The ability of antimony to induce heme oxygenase was dose-dependent, independent of the salt used, and not a result of a direct activation of the enzyme in vitro. Concomitant with heme oxygenase induction by antimony, microsomal heme and cytochrome P-450 contents decreased, the cyto-chrome P-450-dependent mixed function oxidase system was impaired, and delta-ami-nolevulinate synthase (ALAS), the rate-limiting enzyme of heme synthesis, underwent the sequential changes-initial inhibition followed by rebound induction-usually associated with the administration of transition elements such as cobalt. Antimony induction of heme oxygenase however, unlike the enzyme induction elicited by cobalt, was not prevented either by cysteine administered orally or as a cysteine metal complex, or by simultaneous zinc administration. Desferoxamine also did not block heme oxygenase induction by antimony, but this chelator did prevent the rebound increase in ALAS activity associated with antimony or cobalt treatment. Antimony-containing parasiticidal drugs were also potent inducers of heme oxygenase in liver and kidney. The heme degradative action of these drugs may be related in part to the jaundice commonly associated with the prolonged therapeutic use of these agents. The heme-oxygenase-inducing action of antimony-containing parasiticidal drugs is a newly defined biological property of these compounds. The relation between the parasiticidal and the heme-oxygenase-inducing actions of such drugs is unknown. However, certain parasites contain hemoproteins or require heme compounds during their life cycle. It may therefore be

Induction of Protective Genes Leads to Islet Survival and Function

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Hongjun Wang

2011-01-01

Full Text Available Islet transplantation is the most valid approach to the treatment of type 1 diabetes. However, the function of transplanted islets is often compromised since a large number of β cells undergo apoptosis induced by stress and the immune rejection response elicited by the recipient after transplantation. Conventional treatment for islet transplantation is to administer immunosuppressive drugs to the recipient to suppress the immune rejection response mounted against transplanted islets. Induction of protective genes in the recipient (e.g., heme oxygenase-1 (HO-1, A20/tumor necrosis factor alpha inducible protein3 (tnfaip3, biliverdin reductase (BVR, Bcl2, and others or administration of one or more of the products of HO-1 to the donor, the islets themselves, and/or the recipient offers an alternative or synergistic approach to improve islet graft survival and function. In this perspective, we summarize studies describing the protective effects of these genes on islet survival and function in rodent allogeneic and xenogeneic transplantation models and the prevention of onset of diabetes, with emphasis on HO-1, A20, and BVR. Such approaches are also appealing to islet autotransplantation in patients with chronic pancreatitis after total pancreatectomy, a procedure that currently only leads to 1/3 of transplanted patients being diabetes-free.

Curcuma longa (curcumin) decreases in vivo cisplatin-induced ototoxicity through heme oxygenase-1 induction.

Science.gov (United States)

Fetoni, Anna R; Eramo, Sara L M; Paciello, Fabiola; Rolesi, Rolando; Podda, Maria Vittoria; Troiani, Diana; Paludetti, Gaetano

2014-06-01

To investigate whether curcumin may have in vivo protective effects against cisplatin ototoxicity by its direct scavenger activity and/or by curcumin-mediated upregulation of HO-1. Cisplatin-induced ototoxicity is a major dose-limiting side effect in anticancer chemotherapy. A protective approach to decrease cisplatin ototoxicity without compromising its therapeutic efficacy remains a critical goal for anticancer therapy. Recent evidences indicate that curcumin exhibits antioxidant, anti-inflammatory, and chemosensitizer activities. In male adult Wistar rats, a curcumin dose of 200 mg/kg, selected from a dose-response curve, was injected 1 hour before cisplatin administration and once daily for the following 3 days. A single dose of cisplatin (16 mg/kg) was administered intraperitoneally. Rats were divided as follows: 1) control, 2) curcumin control, 3) vehicle control, 4) cisplatin, 5) cisplatin+ vehicle, and 6) curcumin+cisplatin. ABRs were measured before and at Days 3 and 5 after cisplatin administration. Rhodamine-phalloidin staining, 4-hydroxy-2-nonenal and heme-oxigenase-1 immunostainings, and Western blot analyses were performed to assess and quantify OHC loss, lipid peroxidation, and the endogenous response to cisplatin-induced damage and to curcumin protection. Curcumin treatment attenuated hearing loss induced by cisplatin, increased OHC survival, decreased 4-HNE expression, and increased HO-1 expression. This preclinical study demonstrates that systemic curcumin attenuates ototoxicity and provides molecular evidence for a role of HO-1 as an additional mediator in attenuating cisplatin-induced damage.

Purification and characterization of sheep platelet cyclo-oxygenase. Acetylation by aspirin prevents haemin binding to the enzyme.

OpenAIRE

Boopathy, R; Balasubramanian, A S

1986-01-01

Arachidonate cyclo-oxygenase (prostaglandin synthetase; prostaglandin endoperoxide synthetase; EC 1.14.99.1) was purified from sheep platelets. The purification procedure involved hydrophobic column chromatography using either Ibuprofen-Sepharose, phenyl-Sepharose or arachidic acid-Sepharose as the first step followed by metal-chelate Sepharose and haemin-Sepharose affinity chromatography. The purified enzyme (Mr approximately 65,000) was homogeneous as observed by SDS/polyacrylamide-gel elec...

Solution NMR characterization of magnetic/electronic properties of azide and cyanide-inhibited substrate complexes of human heme oxygenase: implications for steric ligand tilt.

Science.gov (United States)

Peng, Dungeng; Ogura, Hiroshi; Ma, Li-Hua; Evans, John P; de Montellano, Paul R Ortiz; La Mar, Gerd N

2013-04-01

Solution 2D (1)H NMR was carried out on the azide-ligated substrate complex of human heme oxygenase, hHO, to provide information on the active site molecular structure, chromophore electronic/magnetic properties, and the distal H-bond network linked to the exogenous ligand by catalytically relevant oriented water molecules. While 2D NMR exhibited very similar patterns of two-dimensional nuclear Overhauser spectroscopy cross peaks of residues with substrate and among residues as the previously characterized cyanide complex, significant, broadly distributed chemical shift differences were observed for both labile and non-labile protons. The anisotropy and orientation of the paramagnetic susceptibility tensor, χ, were determined for both the azide and cyanide complexes. The most significant difference observed is the tilt of the major magnetic axes from the heme normal, which is only half as large for the azide than cyanide ligand, with each ligand tilted toward the catalytically cleaved α-meso position. The difference in chemical shifts is quantitatively correlated with differences in dipolar shifts in the respective complexes for all but the distal helix. The necessity of considering dipolar shifts, and hence determination of the orientation/anisotropy of χ, in comparing chemical shifts involving paramagnetic complexes, is emphasized. The analysis shows that the H-bond network cannot detect significant differences in H-bond acceptor properties of cyanide versus azide ligands. Lastly, significant retardation of distal helix labile proton exchange upon replacing cyanide with azide indicates that the dynamic stability of the distal helix is increased upon decreasing the steric interaction of the ligand with the distal helix. Copyright © 2013. Published by Elsevier Inc.

Fetal Microsatellite in the Heme Oxygenase 1 Promoter Is Associated With Severe and Early-Onset Preeclampsia.

Science.gov (United States)

Kaartokallio, Tea; Utge, Siddheshwar; Klemetti, Miira M; Paananen, Jussi; Pulkki, Kari; Romppanen, Jarkko; Tikkanen, Ilkka; Heinonen, Seppo; Kajantie, Eero; Kere, Juha; Kivinen, Katja; Pouta, Anneli; Lakkisto, Päivi; Laivuori, Hannele

2018-01-01

Preeclampsia is a vascular pregnancy disorder that often involves impaired placental development. HO-1 (heme oxygenase 1, encoded by HMOX1 ) is a stress response enzyme crucial for endothelial and placental function. Long version of the guanine-thymine (GT n ) microsatellite in the HMOX1 promoter decreases HO-1 expression, and the long maternal repeat is associated with late-onset preeclampsia. Our aim was to study whether the length of fetal repeat is associated with mother's preeclampsia, whether the length of fetal and maternal repeats affect HO-1 levels in placenta and maternal serum, and whether HO-1 levels are altered in preeclampsia. We genotyped the repeat in the cord blood of 609 preeclamptic and 745 nonpreeclamptic neonates. HO-1 levels were measured in 36 placental samples, and in the first (222 cases/243 controls) and third (176 cases/53 controls) pregnancy trimester serum samples using enzyme-linked immunosorbent assay. The long fetal GT n repeat was associated with preeclampsia and its severe and early-onset subtypes. Interaction analysis suggested the maternal and fetal effects to be independent. Placental or serum HO-1 levels were not altered in preeclamptics, possibly reflecting heterogeneity of preeclampsia. Carriers of the long fetal and maternal repeats had lower placental and serum HO-1 levels, respectively, providing functional evidence for the association. We conclude that the long fetal GT n repeat may increase mother's risk for especially severe and early-onset preeclampsia. The fetal and maternal risk alleles likely predispose to different disease subtypes. © 2017 American Heart Association, Inc.

Heme oxygenase-1: A new druggable target in the management of chronic and acute myeloid leukemia.

Science.gov (United States)

Salerno, Loredana; Romeo, Giuseppe; Modica, Maria N; Amata, Emanuele; Sorrenti, Valeria; Barbagallo, Ignazio; Pittalà, Valeria

2017-12-15

Heme oxygenase-1 (HO-1) is the enzyme catalyzing the rate-limiting oxidative degradation of cellular heme into free iron, carbon monoxide (CO), and biliverdin, which is then rapidly converted into bilirubin. By means of these catabolic end-products and by removal of pro-oxidant heme, HO-1 exerts antioxidant, antiapoptotic, and immune-modulating effects, leading to overall cytoprotective and beneficial functions in mammalian cells. Therefore, HO-1 is considered a survival molecule in various stress-related conditions. By contrast, growing evidence suggests that HO-1 is a survival-enhancing molecule also in various solid and blood cancers, such as various types of leukemia, promoting carcinogenesis, tumor progression, and chemo-resistance. Among leukemias, chronic myeloid leukemia (CML) is currently therapeutically well treated with tyrosine kinase inhibitors (TKIs) such as Imatinib (IM) and its congeners; nevertheless, resistance to all kinds of current drugs persist in a number of patients. Moreover, treatment outcomes for acute myeloid leukemia (AML) remain unsatisfactory, despite progress in chemotherapy and hematopoietic stem cell transplantation. Therefore, identification of new eligible targets that may improve leukemias therapy is of general interest. Several recent papers prove that inhibition of HO-1 through HO-1 inhibitors as well as modulation of other pathways involving HO-1 by a number of different new or known molecules, are critical for leukemia treatment. This review summarizes the current understanding of the pro-tumorigenic role of HO-1 and its potential as a molecular target for the treatment of leukemias. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Powerful accelerators for bremsstrahlung and electron beams generation on the basis of inductive energy-storage elements

Energy Technology Data Exchange (ETDEWEB)

Diyankov, V S; Kovalev, V P; Kormilitsin, A I; Lavrentev, B N [All-Russian Research Institute of Technical Physics, Snezhinsk (Russian Federation)

1997-12-31

The report summarizes RFNC-VNIITF activities from 1963 till 1995, devoted to the development of pulsed electron accelerators on the basis of inductive energy storage with electroexplosive wires. These accelerators are called IGUR. The activities resulted in the development of a series of generators of powerful radiation being cheap and easy in manufacturing and servicing. The accelerators achieved the following maximum parameters: diode voltage up to 6 MV, diode current up to 80 kA, current of the extracted electron beam 30 kA, density of the extracted electron beam energy 500 J/cm{sup 2}, bremsstrahlung dose 250000 Rads, and bremsstrahlung dose rate 10{sup 13} Rads/sec. (author). 3 tabs., 5 figs., 7 refs.

Powerful accelerators for bremsstrahlung and electron beams generation on the basis of inductive energy-storage elements

International Nuclear Information System (INIS)

Diyankov, V.S.; Kovalev, V.P.; Kormilitsin, A.I.; Lavrentev, B.N.

1996-01-01

The report summarizes RFNC-VNIITF activities from 1963 till 1995, devoted to the development of pulsed electron accelerators on the basis of inductive energy storage with electroexplosive wires. These accelerators are called IGUR. The activities resulted in the development of a series of generators of powerful radiation being cheap and easy in manufacturing and servicing. The accelerators achieved the following maximum parameters: diode voltage up to 6 MV, diode current up to 80 kA, current of the extracted electron beam 30 kA, density of the extracted electron beam energy 500 J/cm 2 , bremsstrahlung dose 250000 Rads, and bremsstrahlung dose rate 10 13 Rads/sec. (author). 3 tabs., 5 figs., 7 refs

Multiple-load series resonant inverter for induction cooking ...

Indian Academy of Sciences (India)

P Sharath Kumar

Department of Electrical & Electronics Engineering, CVR College of Engineering, Hyderabad, ... 8, August 2017, pp. 1309–1316 ..... ference: Towards Sustainable Energy. pp 1–6 ... industrial induction cooker system: circuit design, control.

Induction of Vermillion in Pyralid moths using CRISPR mutagenesis

Science.gov (United States)

Eye color mutations have been useful markers of genetic activity or alteration in insect genetics. Complementation or disruption of transport or biosynthesis of ommochrome (brown) or pteridine (red) pigments have provided useful targets for transgenic procedures. Tryptophan oxygenase (To) (EC 1.13.1...

Diagnostics for induction accelerators

International Nuclear Information System (INIS)

Fessenden, T.J.

1996-04-01

The induction accelerator was conceived by N. C. Christofilos and first realized as the Astron accelerator that operated at LLNL from the early 1960's to the end of 1975. This accelerator generated electron beams at energies near 6 MeV with typical currents of 600 Amperes in 400 ns pulses. The Advanced Test Accelerator (ATA) built at Livermore's Site 300 produced 10,000 Ampere beams with pulse widths of 70 ns at energies approaching 50 MeV. Several other electron and ion induction accelerators have been fabricated at LLNL and LBNL. This paper reviews the principal diagnostics developed through efforts by scientists at both laboratories for measuring the current, position, energy, and emittance of beams generated by these high current, short pulse accelerators. Many of these diagnostics are closely related to those developed for other accelerators. However, the very fast and intense current pulses often require special diagnostic techniques and considerations. The physics and design of the more unique diagnostics developed for electron induction accelerators are presented and discussed in detail

Heme Oxygenase-1/Carbon Monoxide System and Embryonic Stem Cell Differentiation and Maturation into Cardiomyocytes

Science.gov (United States)

Suliman, Hagir B.; Zobi, Fabio

2016-01-01

Abstract Aims: The differentiation of embryonic stem (ES) cells into energetically efficient cardiomyocytes contributes to functional cardiac repair and is envisioned to ameliorate progressive degenerative cardiac diseases. Advanced cell maturation strategies are therefore needed to create abundant mature cardiomyocytes. In this study, we tested whether the redox-sensitive heme oxygenase-1/carbon monoxide (HO-1/CO) system, operating through mitochondrial biogenesis, acts as a mechanism for ES cell differentiation and cardiomyocyte maturation. Results: Manipulation of HO-1/CO to enhance mitochondrial biogenesis demonstrates a direct pathway to ES cell differentiation and maturation into beating cardiomyocytes that express adult structural markers. Targeted HO-1/CO interventions up- and downregulate specific cardiogenic transcription factors, transcription factor Gata4, homeobox protein Nkx-2.5, heart- and neural crest derivatives-expressed protein 1, and MEF2C. HO-1/CO overexpression increases cardiac gene expression for myosin regulatory light chain 2, atrial isoform, MLC2v, ANP, MHC-β, and sarcomere α-actinin and the major mitochondrial fusion regulators, mitofusin 2 and MICOS complex subunit Mic60. This promotes structural mitochondrial network expansion and maturation, thereby supporting energy provision for beating embryoid bodies. These effects are prevented by silencing HO-1 and by mitochondrial reactive oxygen species scavenging, while disruption of mitochondrial biogenesis and mitochondrial DNA depletion by loss of mitochondrial transcription factor A compromise infrastructure. This leads to failure of cardiomyocyte differentiation and maturation and contractile dysfunction. Innovation: The capacity to augment cardiomyogenesis via a defined mitochondrial pathway has unique therapeutic potential for targeting ES cell maturation in cardiac disease. Conclusion: Our findings establish the HO-1/CO system and redox regulation of mitochondrial biogenesis as

Heme oxygenase activity correlates with serum indices of iron homeostasis in healthy nonsmokers

Science.gov (United States)

Heme oxygenase (HO) catalyzes the breakdown of heme to carbon monoxide, iron, and biliverdin. While the use of genetically altered animal models in investigation has established distinct associations between HO activity and systemic iron availability, studies have not yet confirm...

Fibroblast growth factor 10 protects neuron against oxygen–glucose deprivation injury through inducing heme oxygenase-1

International Nuclear Information System (INIS)

Li, Yong-Hua; Yang, Li-Ye; Chen, Wei; Li, Ying-Ke; Yuan, Hong-Bin

2015-01-01

Highlights: • FGF10 attenuates OGD induced injury in cortical neuron. • FGF10 reduces OGD triggered ROS level in cortical neuron. • FGF10 induces HO-1 expression upon OGD stimuli in cortical neuron. • Knockdown of HO-1 impairs the neuroprotection of FGF10 in OGD model. - Abstract: Fibroblast growth factors (FGFs) are a family of structurally related heparin-binding proteins with diverse biological functions. FGFs participate in mitogenesis, angiogenesis, cell proliferation, development, differentiation and cell migration. Here, we investigated the potential effect of FGF10, a member of FGFs, on neuron survival in oxygen–glucose deprivation (OGD) model. In primary cultured mouse cortical neurons upon OGD, FGF10 treatment (100 and 1000 ng/ml) attenuated the decrease of cell viability and rescued the LDH release. Tuj-1 immunocytochemistry assay showed that FGF10 promoted neuronal survival. Apoptosis assay with Annexin V + PI by flow cytometry demonstrated that FGF10 treatment reduced apoptotic cell proportion. Moreover, immunoblotting showed that FGF10 alleviated the cleaved caspase-3 upregulation caused by OGD. FGF10 treatment also depressed the OGD-induced increase of caspase-3, -8 and -9 activities. At last, we found FGF10 triggered heme oxygenase-1 (HO-1) protein expression rather than hypoxia-inducible factor-1 (HIF-1), AMP-activated protein kinase (AMPK) signaling and extracellular signal-regulated kinases 1/2 (ERK1/2) signaling. Knockdown of HO-1 by siRNA partly abolished the neuroprotection of FGF10 in OGD model. In summary, our observations provide the first evidence for the neuroprotective function of FGF10 against ischemic neuronal injury and suggest that FGF10 may be a promising agent for treatment of ischemic stroke

Fibroblast growth factor 10 protects neuron against oxygen–glucose deprivation injury through inducing heme oxygenase-1

Energy Technology Data Exchange (ETDEWEB)

Li, Yong-Hua; Yang, Li-Ye; Chen, Wei; Li, Ying-Ke, E-mail: liyingke6f@126.com; Yuan, Hong-Bin, E-mail: yuanhongbin6f@126.com

2015-01-02

Highlights: • FGF10 attenuates OGD induced injury in cortical neuron. • FGF10 reduces OGD triggered ROS level in cortical neuron. • FGF10 induces HO-1 expression upon OGD stimuli in cortical neuron. • Knockdown of HO-1 impairs the neuroprotection of FGF10 in OGD model. - Abstract: Fibroblast growth factors (FGFs) are a family of structurally related heparin-binding proteins with diverse biological functions. FGFs participate in mitogenesis, angiogenesis, cell proliferation, development, differentiation and cell migration. Here, we investigated the potential effect of FGF10, a member of FGFs, on neuron survival in oxygen–glucose deprivation (OGD) model. In primary cultured mouse cortical neurons upon OGD, FGF10 treatment (100 and 1000 ng/ml) attenuated the decrease of cell viability and rescued the LDH release. Tuj-1 immunocytochemistry assay showed that FGF10 promoted neuronal survival. Apoptosis assay with Annexin V + PI by flow cytometry demonstrated that FGF10 treatment reduced apoptotic cell proportion. Moreover, immunoblotting showed that FGF10 alleviated the cleaved caspase-3 upregulation caused by OGD. FGF10 treatment also depressed the OGD-induced increase of caspase-3, -8 and -9 activities. At last, we found FGF10 triggered heme oxygenase-1 (HO-1) protein expression rather than hypoxia-inducible factor-1 (HIF-1), AMP-activated protein kinase (AMPK) signaling and extracellular signal-regulated kinases 1/2 (ERK1/2) signaling. Knockdown of HO-1 by siRNA partly abolished the neuroprotection of FGF10 in OGD model. In summary, our observations provide the first evidence for the neuroprotective function of FGF10 against ischemic neuronal injury and suggest that FGF10 may be a promising agent for treatment of ischemic stroke.

Acidithiobacillus caldus sulfur oxidation model based on transcriptome analysis between the wild type and sulfur oxygenase reductase defective mutant.

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Linxu Chen

Full Text Available Acidithiobacillus caldus (A. caldus is widely used in bio-leaching. It gains energy and electrons from oxidation of elemental sulfur and reduced inorganic sulfur compounds (RISCs for carbon dioxide fixation and growth. Genomic analyses suggest that its sulfur oxidation system involves a truncated sulfur oxidation (Sox system (omitting SoxCD, non-Sox sulfur oxidation system similar to the sulfur oxidation in A. ferrooxidans, and sulfur oxygenase reductase (SOR. The complexity of the sulfur oxidation system of A. caldus generates a big obstacle on the research of its sulfur oxidation mechanism. However, the development of genetic manipulation method for A. caldus in recent years provides powerful tools for constructing genetic mutants to study the sulfur oxidation system.An A. caldus mutant lacking the sulfur oxygenase reductase gene (sor was created and its growth abilities were measured in media using elemental sulfur (S(0 and tetrathionate (K(2S(4O(6 as the substrates, respectively. Then, comparative transcriptome analysis (microarrays and real-time quantitative PCR of the wild type and the Δsor mutant in S(0 and K(2S(4O(6 media were employed to detect the differentially expressed genes involved in sulfur oxidation. SOR was concluded to oxidize the cytoplasmic elemental sulfur, but could not couple the sulfur oxidation with the electron transfer chain or substrate-level phosphorylation. Other elemental sulfur oxidation pathways including sulfur diooxygenase (SDO and heterodisulfide reductase (HDR, the truncated Sox pathway, and the S(4I pathway for hydrolysis of tetrathionate and oxidation of thiosulfate in A. caldus are proposed according to expression patterns of sulfur oxidation genes and growth abilities of the wild type and the mutant in different substrates media.An integrated sulfur oxidation model with various sulfur oxidation pathways of A. caldus is proposed and the features of this model are summarized.

Binding of Multiple Rap1 Proteins Stimulates Chromosome Breakage Induction during DNA Replication.

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Greicy H Goto

2015-08-01

Full Text Available Telomeres, the ends of linear eukaryotic chromosomes, have a specialized chromatin structure that provides a stable chromosomal terminus. In budding yeast Rap1 protein binds to telomeric TG repeat and negatively regulates telomere length. Here we show that binding of multiple Rap1 proteins stimulates DNA double-stranded break (DSB induction at both telomeric and non-telomeric regions. Consistent with the role of DSB induction, Rap1 stimulates nearby recombination events in a dosage-dependent manner. Rap1 recruits Rif1 and Rif2 to telomeres, but neither Rif1 nor Rif2 is required for DSB induction. Rap1-mediated DSB induction involves replication fork progression but inactivation of checkpoint kinase Mec1 does not affect DSB induction. Rap1 tethering shortens artificially elongated telomeres in parallel with telomerase inhibition, and this telomere shortening does not require homologous recombination. These results suggest that Rap1 contributes to telomere homeostasis by promoting chromosome breakage.

Characterization of 3-Ketosteroid 9α-Hydroxylase, a Rieske Oxygenase in the Cholesterol Degradation Pathway of Mycobacterium tuberculosis*S⃞

OpenAIRE

Capyk, Jenna K.; D'Angelo, Igor; Strynadka, Natalie C.; Eltis, Lindsay D.

2009-01-01

KshAB (3-Ketosteroid 9α-hydroxylase) is a two-component Rieske oxygenase (RO) in the cholesterol catabolic pathway of Mycobacterium tuberculosis. Although the enzyme has been implicated in pathogenesis, it has largely been characterized by bioinformatics and molecular genetics. Purified KshB, the reductase component, was a monomeric protein containing a plant-type [2Fe-2S] cluster and FAD. KshA, the oxygenase, was a homotrimer containing a Rieske [2Fe-2S] cluster and m...

Fast wave direct electron heating in advanced inductive and ITER baseline scenario discharges in DIII-D

Energy Technology Data Exchange (ETDEWEB)

Pinsker, R. I.; Jackson, G. L.; Luce, T. C.; Politzer, P. A. [General Atomics, PO Box 85608, San Diego, California 92186-5608 (United States); Austin, M. E. [University of Texas at Austin, Austin, Texas 78712 (United States); Diem, S. J.; Kaufman, M. C.; Ryan, P. M. [Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Doyle, E. J.; Zeng, L. [University of California Los Angeles, Los Angeles, California 90095 (United States); Grierson, B. A.; Hosea, J. C.; Nagy, A.; Perkins, R.; Solomon, W. M.; Taylor, G. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Maggiora, R.; Milanesio, D. [Politecnico di Torino, Dipartimento di Elettronica, Torino (Italy); Porkolab, M. [Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Turco, F. [Columbia University, New York, New York 10027 (United States)

2014-02-12

Fast Wave (FW) heating and electron cyclotron heating (ECH) are used in the DIII-D tokamak to study plasmas with low applied torque and dominant electron heating characteristic of burning plasmas. FW heating via direct electron damping has reached the 2.5 MW level in high performance ELMy H-mode plasmas. In Advanced Inductive (AI) plasmas, core FW heating was found to be comparable to that of ECH, consistent with the excellent first-pass absorption of FWs predicted by ray-tracing models at high electron beta. FW heating at the ∼2 MW level to ELMy H-mode discharges in the ITER Baseline Scenario (IBS) showed unexpectedly strong absorption of FW power by injected neutral beam (NB) ions, indicated by significant enhancement of the D-D neutron rate, while the intended absorption on core electrons appeared rather weak. The AI and IBS discharges are compared in an effort to identify the causes of the different response to FWs.

Chinese herbal medicine compound Yi-Zhi-Hao pellet inhibits replication of influenza virus infection through activation of heme oxygenase-1

Directory of Open Access Journals (Sweden)

Jinqiu Yin

2017-11-01

Full Text Available As a leading cause of respiratory disease, influenza A virus (IAV presents a pandemic threat in annual seasonal outbreaks. Given the limitation of existing anti-influenza therapies, there remains to be a requirement for new drugs. Compound Yi-Zhi-Hao pellet (CYZH is a famous traditional Chinese medicine (TCM used in the clinic, whose formula has been recorded in Complication of National Standard for Traditional Chinese Medicine to treat common cold. In this study, we found that CYZH exhibited a broad-spectrum anti-influenza activity and inhibited the expression of viral RNA and proteins in vitro. Mechanistically, CYZH had no inhibitory activities against viral protein hemagglutinin and IAV RNA-dependent RNA polymerase. Instead, it induced activation of erythroid 2-related factor 2 (Nrf2 and nuclear factor kappa B (NF-κB, which subsequently upregulated heme oxygenase-1 (HO-1 expression. Also, CYZH protected cells from oxidative damage induced by reactive oxygen series. In conclusions, CYZH inhibits IAV replication in vitro, at least partly by activating expression of the Nrf2/HO-1 pathway.

Erythropoietin Attenuates Pulmonary Vascular Remodeling in Experimental Pulmonary Arterial Hypertension through Interplay between Endothelial Progenitor Cells and Heme Oxygenase

OpenAIRE

van Loon, Rosa Laura E; Bartelds, Beatrijs; Wagener, Frank A D T G; Affara, Nada; Mohaupt, Saffloer; Wijnberg, Hans; Pennings, Sebastiaan W C; Takens, Janny; Berger, Rolf M F

2015-01-01

BACKGROUND: Pulmonary arterial hypertension (PAH) is a pulmonary vascular disease with a high mortality, characterized by typical angio-proliferative lesions. Erythropoietin (EPO) attenuates pulmonary vascular remodeling in PAH. We postulated that EPO acts through mobilization of endothelial progenitor cells (EPCs) and activation of the cytoprotective enzyme heme oxygenase-1 (HO-1). METHODS: Rats with flow-associated PAH, resembling pediatric PAH, were treated with HO-1 inducer EPO in the pre...

Erythropoietin Attenuates Pulmonary Vascular Remodeling in Experimental Pulmonary Arterial Hypertension through Interplay between Endothelial Progenitor Cells and Heme Oxygenase

OpenAIRE

van Loon, Rosa Laura E.; Bartelds, Beatrijs; Wagener, Frank A. D. T. G.; Affara, Nada; Mohaupt, Saffloer; Wijnberg, Hans; Pennings, Sebastiaan W. C.; Takens, Janny; Berger, Rolf M. F.

2015-01-01

Background Pulmonary arterial hypertension (PAH) is a pulmonary vascular disease with a high mortality, characterized by typical angio-proliferative lesions. Erythropoietin (EPO) attenuates pulmonary vascular remodeling in PAH. We postulated that EPO acts through mobilization of endothelial progenitor cells (EPCs) and activation of the cytoprotective enzyme heme oxygenase-1 (HO-1). Methods Rats with flow-associated PAH, resembling pediatric PAH, were treated with HO-1 inducer EPO i...

Postneonatal Mortality and Liver Changes in Cloned Pigs Associated with Human Tumor Necrosis Factor Receptor I-Fc and Human Heme Oxygenase-1 Overexpression.

Science.gov (United States)

Kim, Geon A; Jin, Jun-Xue; Lee, Sanghoon; Taweechaipaisankul, Anukul; Oh, Hyun Ju; Hwang, Joing-Ik; Ahn, Curie; Saadeldin, Islam M; Lee, Byeong Chun

2017-01-01

Soluble human tumor necrosis factor (shTNFRI-Fc) and human heme oxygenase 1 (hHO-1) are key regulators for protection against oxidative and inflammatory injury for xenotransplantation. Somatic cells with more than 10 copy numbers of shTNFRI-Fc and hHO-1 were employed in somatic cell nuclear transfer to generate cloned pigs, thereby resulting in seven cloned piglets. However, produced piglets were all dead within 24 hours after birth. Obviously, postnatal death with liver apoptosis was reported in the higher copy number of shTNFRI-Fc and hHO-1 piglets. In liver, the transcript levels of ferritin heavy chain, light chain, transferrin, and inducible nitric oxide synthase were significantly highly expressed compared to those of lower copy number of shTNFRI-Fc and hHO-1 piglets ( P hHO-1 piglets ( P hHO-1 overexpression may apparently induce free iron in the liver and exert oxidative stress by enhancing reactive oxygen species production and block normal postneonatal liver metabolism.

Beam transport study of kA-class on the induction linac

Energy Technology Data Exchange (ETDEWEB)

Morimoto, Iwao; Zheng, Xiaodong; Maebara, Sunao; Shiho, Makoto [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Kishiro, Jun-ichi; Takayama, Ken [High Energy Accelerator Research Organization, Tsukuba, Ibaraki (Japan)

2000-02-01

Beam transport of kA-class for GW-class Free Electron Laser (FEL) was carried out through the two induction linacs (JLA). The first 1 MV induction linac was used as an electron beam generator, in which a carbon-cloth impregnated cold cathode was equipped and 1 MV, 160ns pulsed high voltage was immersed. About 1 kA high current electron beam was successfully generated and accelerated more 1 MeV by employing the following second induction linac. For kA-class high current beam generation and transportation, the most serious problem arises from the so strong space charge effect that the investigations to cure this effect both in the beam generation and the transportation are required. High rate beam loss comes from the strong space charge effect because the effect causes the unexpected beam blow up during the transportation. In the electron generator, the generated beam emittance was minimized with the program EGUN by choosing the geometry and shape of the cathode and anode electrode. In the beam transportation, a simulation program which included the space charge effect was developed. The simulation program was used to minimize and optimize the beam envelope oscillation through the beam transport line, and designed the configuration of the solenoid magnet channel. Experimentally, the electron beam of 450 A was extracted. The beam transport efficiency (beam current at outlet of accelerator/at inlet) reached to 90%, under the magnetic field of 1 kG. It was succeeded that the electron beam of 2 MeV - 400 A was transported with the mean beam diameter of 50 mm. (author)

Half Bridge Inductive Heater

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Zoltán GERMÁN-SALLÓ

2015-12-01

Full Text Available Induction heating performs contactless, efficient and fast heating of conductive materials, therefore became one of the preferred heating procedure in industrial, domestic and medical applications. During induction heating the high-frequency alternating currents that heat the material are induced by means of electromagnetic induction. The material to be heated is placed inside the time-varying magnetic field generated by applying a highfrequency alternating current to an induction coil. The alternating electromagnetic field induces eddy currents in the workpiece, resulting resistive losses, which then heat the material. This paper describes the design of a power electronic converter circuit for induction heating equipment and presents the obtained results. The realized circuit is a low power half bridge resonant inverter which uses power MOS transistors and adequate driver circuits.

Diagnostics for induction accelerators

International Nuclear Information System (INIS)

Fessenden, T.J.

1997-01-01

The induction accelerator was conceived by N. C. Christofilos and first realized as the Astron accelerator that operated at Lawrence Livermore National Laboratory (LLNL) from the early 1960s to the end of 1975. This accelerator generated electron beams at energies near 6 MeV with typical currents of 600 Amperes in 400-ns pulses. The Advanced Test Accelerator (ATA) built at Livermore close-quote s Site 300 produced 10,000-Ampere beams with pulse widths of 70 ns at energies approaching 50 MeV. Several other electron and ion induction accelerators have been fabricated at LLNL and Lawrence Berkeley National Laboratory (LBNL). This paper reviews the principal diagnostics developed through efforts by scientists at both laboratories for measuring the current, position, energy, and emittance of beams generated by these high-current, short-pulse accelerators. Many of these diagnostics are closely related to those developed for other accelerators. However, the very fast and intense current pulses often require special diagnostic techniques and considerations. The physics and design of the more unique diagnostics developed for electron induction accelerators are presented and discussed in detail. copyright 1997 American Institute of Physics

Characterization of heme oxygenase and biliverdin reductase gene expression in zebrafish (Danio rerio): Basal expression and response to pro-oxidant exposures

International Nuclear Information System (INIS)

Holowiecki, Andrew; O'Shields, Britton; Jenny, Matthew J.

2016-01-01

While heme is an important cofactor for numerous proteins, it is highly toxic in its unbound form and can perpetuate the formation of reactive oxygen species. Heme oxygenase enzymes (HMOX1 and HMOX2) degrade heme into biliverdin and carbon monoxide, with biliverdin subsequently being converted to bilirubin by biliverdin reductase (BVRa or BVRb). As a result of the teleost-specific genome duplication event, zebrafish have paralogs of hmox1 (hmox1a and hmox1b) and hmox2 (hmox2a and hmox2b). Expression of all four hmox paralogs and two bvr isoforms were measured in adult tissues (gill, brain and liver) and sexually dimorphic differences were observed, most notably in the basal expression of hmox1a, hmox2a, hmox2b and bvrb in liver samples. hmox1a, hmox2a and hmox2b were significantly induced in male liver tissues in response to 96 h cadmium exposure (20 μM). hmox2a and hmox2b were significantly induced in male brain samples, but only hmox2a was significantly reduced in male gill samples in response to the 96 h cadmium exposure. hmox paralogs displayed significantly different levels of basal expression in most adult tissues, as well as during zebrafish development (24 to 120 hpf). Furthermore, hmox1a, hmox1b and bvrb were significantly induced in zebrafish eleutheroembryos in response to multiple pro-oxidants (cadmium, hemin and tert-butylhydroquinone). Knockdown of Nrf2a, a transcriptional regulator of hmox1a, was demonstrated to inhibit the Cd-mediated induction of hmox1b and bvrb. These results demonstrate distinct mechanisms of hmox and bvr transcriptional regulation in zebrafish, providing initial evidence of the partitioning of function of the hmox paralogs. - Highlights: • hmox1a, hmox2a, hmox2b and bvrb are sexually dimorphic in expression. • hmox paralogs were induced in adult tissues by cadmium exposure. • hmox1a, hmox1b and bvrb were induced by multiple pro-oxidants zebrafish embryos. • Differential expression of zebrafish hmox paralogs suggest

Characterization of heme oxygenase and biliverdin reductase gene expression in zebrafish (Danio rerio): Basal expression and response to pro-oxidant exposures

Energy Technology Data Exchange (ETDEWEB)

Holowiecki, Andrew [Department of Biological Sciences, University of Alabama, Tuscaloosa, AL 35487 (United States); Molecular Cardiovascular Biology Division and Heart Institute, Cincinnati Children' s Research Foundation, Cincinnati, OH (United States); O' Shields, Britton [Department of Biological Sciences, University of Alabama, Tuscaloosa, AL 35487 (United States); Jenny, Matthew J., E-mail: mjjenny@ua.edu [Department of Biological Sciences, University of Alabama, Tuscaloosa, AL 35487 (United States)

2016-11-15

While heme is an important cofactor for numerous proteins, it is highly toxic in its unbound form and can perpetuate the formation of reactive oxygen species. Heme oxygenase enzymes (HMOX1 and HMOX2) degrade heme into biliverdin and carbon monoxide, with biliverdin subsequently being converted to bilirubin by biliverdin reductase (BVRa or BVRb). As a result of the teleost-specific genome duplication event, zebrafish have paralogs of hmox1 (hmox1a and hmox1b) and hmox2 (hmox2a and hmox2b). Expression of all four hmox paralogs and two bvr isoforms were measured in adult tissues (gill, brain and liver) and sexually dimorphic differences were observed, most notably in the basal expression of hmox1a, hmox2a, hmox2b and bvrb in liver samples. hmox1a, hmox2a and hmox2b were significantly induced in male liver tissues in response to 96 h cadmium exposure (20 μM). hmox2a and hmox2b were significantly induced in male brain samples, but only hmox2a was significantly reduced in male gill samples in response to the 96 h cadmium exposure. hmox paralogs displayed significantly different levels of basal expression in most adult tissues, as well as during zebrafish development (24 to 120 hpf). Furthermore, hmox1a, hmox1b and bvrb were significantly induced in zebrafish eleutheroembryos in response to multiple pro-oxidants (cadmium, hemin and tert-butylhydroquinone). Knockdown of Nrf2a, a transcriptional regulator of hmox1a, was demonstrated to inhibit the Cd-mediated induction of hmox1b and bvrb. These results demonstrate distinct mechanisms of hmox and bvr transcriptional regulation in zebrafish, providing initial evidence of the partitioning of function of the hmox paralogs. - Highlights: • hmox1a, hmox2a, hmox2b and bvrb are sexually dimorphic in expression. • hmox paralogs were induced in adult tissues by cadmium exposure. • hmox1a, hmox1b and bvrb were induced by multiple pro-oxidants zebrafish embryos. • Differential expression of zebrafish hmox paralogs suggest

A physical model for low-frequency electromagnetic induction in the near field based on direct interaction between transmitter and receiver electrons.

Science.gov (United States)

Smith, Ray T; Jjunju, Fred P M; Young, Iain S; Taylor, Stephen; Maher, Simon

2016-07-01

A physical model of electromagnetic induction is developed which relates directly the forces between electrons in the transmitter and receiver windings of concentric coaxial finite coils in the near-field region. By applying the principle of superposition, the contributions from accelerating electrons in successive current loops are summed, allowing the peak-induced voltage in the receiver to be accurately predicted. Results show good agreement between theory and experiment for various receivers of different radii up to five times that of the transmitter. The limitations of the linear theory of electromagnetic induction are discussed in terms of the non-uniform current distribution caused by the skin effect. In particular, the explanation in terms of electromagnetic energy and Poynting's theorem is contrasted with a more direct explanation based on variable filament induction across the conductor cross section. As the direct physical model developed herein deals only with forces between discrete current elements, it can be readily adapted to suit different coil geometries and is widely applicable in various fields of research such as near-field communications, antenna design, wireless power transfer, sensor applications and beyond.

Functional and toxicological consequences of metabolic bioactivation of methapyrilene via thiophene S-oxidation: Induction of cell defence, apoptosis and hepatic necrosis

International Nuclear Information System (INIS)

Mercer, Amy E.; Regan, Sophie L.; Hirst, Charlotte M.; Graham, Emma E.; Antoine, Daniel J.; Benson, Craig A.; Williams, Dominic P.; Foster, John; Kenna, J. Gerry; Park, B. Kevin

2009-01-01

Methapyrilene, [N,N-dimethyl-N'-pyridyl-N'(2-thienylmethyl)-1,2-ethanediamine] (MP) was withdrawn from, clinical use due to reported periportal hepatic necrosis and hepatocarcinogenicity in the rat, via S-oxidation of the thiophene group. In this study MP is used as a model hepatotoxin to further characterise the functional consequences of S-oxidation of the thiophene group in vivo, in rat models and in vitro, in freshly isolated rat hepatocyte suspensions. In vivo histological studies revealed the early depletion of glutathione (GSH), which was confined to the damaged periportal area, in contrast to an increase in GSH levels in the centrilobular region. Additionally, the induction of cell defence was demonstrated by an increase in the protein levels of heme-oxygenase 1 (HO-1) and glutamate cysteine ligase, catalytic subunit (GCLC) in vivo. Histological examination demonstrated that cytotoxicity progresses initially via apoptosis before an increase in necrosis over the 3-day administration. An apoptotic-like mechanism was observed in vitro via the measurement of cytochrome c release and caspase activation. Conclusion: This study provides evidence for a complex pathway of MP-induced hepatotoxicity which progresses through early adaptation, apoptosis, necrosis and inflammation, all underpinned by the zonal induction and depletion of GSH within the liver.

IN VITRO STUDIES ON HEME OXYGENASE-1 AND P24 ANTIGEN HIV-1 LEVEL AFTERHYPERBARIC OXYGEN TREATMENTOFHIV-1 INFECTED ON PERIPHERAL BLOOD MONONUCLEAR CELLS (PBMCS).

Science.gov (United States)

Budiarti, Retno; Kuntaman; Nasronudin; Suryokusumo; Khairunisa, Siti Qamariyah

2018-01-01

Heme oxygenase-1 (HO-1) is a protein secreted by immune cells as a part of immune response mechanism.HO-1 can be induced by variety agents that causingoxidative stress, such as exposure to 100% oxygenat2,4 ATA pressure.It plays a vital role in maintaining cellular homeostasis.This study was conducted to identify the effect of hyperbaric oxygen exposure in cultured ofPBMCthat infected by HIV-1. Primary culture of PBMCs were isolated from 16 healthy volunteers and HIV-1 infected MT4 cell line by co-culture. The PBMCs were aliquoted into two wells as control group and treatment group. The 16 samples of HIV-1 infected PBMCwere exposed to oxygen at 2,4 ATA in animal hyperbaric chamber forthree times in 30 minutes periods with 5 minutes spacing period, that called 1 session.The Treatment done on 5 sessions within 5 days. 16 samples of HIV-1 infected PMBCs that have no hyperbaric treatment became control group.The supernatant were measured the HO-1 production by ELISA andmRNA expression of HO-1 by real time PCR and the number ofantigen p24 HIV-1by ELISA. The result showed that there was no increasing of HO-1 at both mRNA level and protein level, there was a decreasing number of antigen p24 HIV-1 at the treatment group. In addition, hyperbaric exposure could not increase the expression of HO-1, more over the viral replication might be reduced by other mechanism. Hyperbaric oxygen could increases cellular adaptive response of PBMCs infected HIV-1 through increased expression of proteins that can inhibit HIV viralreplication.

Transforming growth factor β1 enhances heme oxygenase 1 expression in human synovial fibroblasts by inhibiting microRNA 519b synthesis.

Directory of Open Access Journals (Sweden)

Shu-Jui Kuo

Full Text Available Osteoarthritis (OA is manifested by synovial inflammation and cartilage destruction that is directly linked to synovitis, joint swelling and pain. In the light of the role of synovium in the pathogenesis and the symptoms of OA, synovium-targeted therapy is a promising strategy to mitigate the symptoms and progression of OA. Transforming growth factor beta 1 (TGF-β1, a secreted homodimeric protein, possesses unique and potent anti-inflammatory and immune-regulatory properties in many cell types. Heme oxygenase 1 (HO-1 is an inducible anti-inflammatory and stress responsive enzyme that has been proven to prevent injuries caused by many diseases. Despite the similar anti-inflammatory profile and their involvement in the pathogenesis of arthritic diseases, no studies have as yet explored the possibility of any association between the expression of TGF-β1 and HO-1.TGF-β1-induced HO-1 expression was examined by HO-1 promoter assay, qPCR, and Western blotting. The siRNAs and enzyme inhibitors were utilized to determine the intermediate involved in the signal transduction pathway. We showed that TGF-β1 stimulated the synthesis of HO-1 in a concentration- and time-dependent manner, which can be mitigated by blockade of the phospholipase (PLCγ/protein kinase C alpha (PKCα pathway. We also showed that the expression of miRNA-519b, which blocks HO-1 transcription, is inhibited by TGF-β1, and the suppression of miRNA 519b could be reversed via blockade of the PLCγ/PKCα pathway.TGF-β1 stimulated the expression of HO-1 via activating the PLCγ/PKCα pathway and suppressing the downstream expression of miRNA-519b. These results may shed light on the pathogenesis and treatment of OA.

Non-inductive current start-up and plasma equilibrium with an inboard poloidal field null by means of electron cyclotron waves in QUEST

International Nuclear Information System (INIS)

Zushi, H.; Hasegawa, M.; Hanada, K.; Idei, H.; Nakamura, K.; Fujisawa, A.; Nagashima, Y.; Matsuoka, K.; Tashima, S.; Ishiguro, M.; Banerjee, S.; Sharma, S.K.; Liu, H.; Nishino, N.; Isobe, M.; Toi, K.; Okamura, S.; Maekawa, T.; Fukuyama, A.; Ejiri, A.; Yamaguchi, T.; Hiratsuka, J.; Takase, Y.; Kikuchi, Mitsuru; Ueda, Y.; Mitarai, O.

2012-11-01

Non-inductive current start-up via relativistic electron cyclotron resonance interaction is investigated for the high ratio (∼10%) of vertical B v to toroidal B t fields and the concave field lines in the QUEST spherical tokamak. In the start-up scenario with an internal poloidal field null (IPN), the fast current start-up rate of 0.3-0.5 MA/sec and correlation with mildly relativistic electrons accelerated due to multiple ECR interaction are observed. In steady state high β p equilibrium characterized by the inboard null (R s ∼ 0.7×R 0 ) and εβ p of 1.5 is achieved, where ε, β p are the inverse aspect ratio and poloidal beta, respectively. Relaxation oscillations in this equilibrium and confinement of the energetic electrons are discussed. (author)

Prostaglandin E2 and the protein kinase A pathway mediate arachidonic acid induction of c-fos in human prostate cancer cells

Science.gov (United States)

Chen, Y.; Hughes-Fulford, M.

2000-01-01

Arachidonic acid (AA) is the precursor for prostaglandin E2 (PGE2) synthesis and increases growth of prostate cancer cells. To further elucidate the mechanisms involved in AA-induced prostate cell growth, induction of c-fos expression by AA was investigated in a human prostate cancer cell line, PC-3. c-fos mRNA was induced shortly after addition of AA, along with a remarkable increase in PGE2 production. c-fos expression and PGE2 production induced by AA was blocked by a cyclo-oxygenase inhibitor, flurbiprofen, suggesting that PGE2 mediated c-fos induction. Protein kinase A (PKA) inhibitor H-89 abolished induction of c-fos expression by AA, and partially inhibited PGE2 production. Protein kinase C (PKC) inhibitor GF109203X had no significant effect on c-fos expression or PGE2 production. Expression of prostaglandin (EP) receptors, which mediate signal transduction from PGE2 to the cells, was examined by reverse transcription polymerase chain reaction in several human prostate cell lines. EP4 and EP2, which are coupled to the PKA signalling pathway, were expressed in all cells tested. Expression of EP1, which activates the PKC pathway, was not detected. The current study showed that induction of the immediate early gene c-fos by AA is mediated by PGE2, which activates the PKA pathway via the EP2/4 receptor in the PC-3 cells.

Identification of Heme Oxygenase-1 as a Novel Predictor of Hematopoietic Stem Cell Transplantation Outcomes in Acute Leukemia

Directory of Open Access Journals (Sweden)

Yinghao Lu

2016-09-01

Full Text Available Objective: The main aim of this study was to determine the correlation between clinical outcome and heme oxygenase-1 (HO-1 expression before and after hematopoietic stem cell transplantation (HSCT in acute leukemia. Methods: HO-1 mRNA levels in 83 patients were measured using qRT-PCR. In a comparative analysis of HO-1 levels in relation to different post-transplant outcomes, the HO-1 threshold, determined via the receiver operating characteristic (ROC curve, was effectively used to predict clinical relapse and acute graft-versus-host disease (aGVHD. The correlations among clinical relapse, aGVHD and HO-1 expression were analyzed based on this threshold. Results: Leukemia risk stratification and relative expression of HO-1 before pretreatment had significant effects on clinical relapse. Leukemia risk stratification, relative expression of HO-1 after HSCT and the interval from diagnosis to transplantation had a significant influence on aGVHD. Both relapse and aGVHD appeared to be associated with relative HO-1 expression. The relative expression rate of HO-1 was 1.131-1.186 before pretreatment, and strongly associated with post-transplantation relapse. The relative expression rate of HO-1 was 1.102-1.144 after transplantation, and closely related to aGVHD. ROC curve analysis revealed high specificity and sensitivity of HO-1 expression in predicting relapse and aGVHD after allo-HSCT. Conclusions: HO-1 expression can be effectively used as a predictor of relapse as well as a diagnostic factor of aGVHD after transplantation for allo-HSCT patients with acute leukemia.

Effect of dimethyl fumarate on heme oxygenase-1 expression in experimental allergic encephalomyelitis in rats

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Kaja Kasarełło

2017-12-01

Full Text Available Multiple sclerosis (MS is an autoimmunological disease leading to neurodegeneration. The etiology of the disease remains unknown, which strongly impedes the development of effective therapy. Most MS treatments focus on modulating the activity of the immune system. Dimethyl fumarate (DMF exerts a broad spectrum of action, such as modulating immune cell differentiation towards anti-inflammatory subtypes, influencing cytokine production, regulating immune cell migration into the central nervous system, and activating intracellular antioxidant mechanisms. It is well established that activation of the nuclear factor E2 (Nrf2-dependent pathway, leading to expression of the second-phase antioxidant enzymes, is influenced by DMF. In our experiments we used female Lewis rats in an animal model of MS – experimental allergic encephalomyelitis (EAE. The rats were fed with dimethyl fumarate to test the expression of heme oxygenase-1 (HO-1, one of the second-phase antioxidant enzymes, at specific time points of the symptomatic phases of the disease: on the first day of the occurrence of clinical symptoms (10th day post immunization, DPI; at the peak of clinical symptoms (14th DPI; and at the end of the relapse (21st DPI. The results showed that HO-1 expression, at both the mRNA and protein level, is influenced by DMF administration only at the very beginning of the symptomatic phase of EAE, and not at the peak of clinical symptoms, nor at the end of the relapse. This indicates that the regulation of the Nrf2-dependent antioxidant pathway by DMF occurs at a certain time interval (early EAE/MS and strongly underlines the importance of the earliest introduction of the therapy to the patient.

Design of planar electron gun for UHF range, CW power inductive output tube

International Nuclear Information System (INIS)

Kaushik, Meenu; Joshi, L.M.

2015-01-01

Inductive Output Tube (lOT) is an amplifier which is now-a-days in demand for scientific applications. For every vacuum tube, electron gun is an important part and in fact considered as the heart of the tube. Hence, designing of this component is very crucial for efficient operation of the device throughout its lifetime. This paper is all about the electromagnetic (EM) design of planar electron gun of 40 kV, 3.5 A beam voltage and beam current respectively, for a 100 kW CW power lOT operating in UHF range. The design considerations and basic equations involved in its design are included in the paper. The gun structure has been optimized for getting the desired beam characteristics. The simulation results including the beam profile along with the beam current are shown using two commercial codes namely TRAK and MAGIC code. Planar shape of electron beam reduces space charge forces in the beam itself and consequently beam energy spread for a given current. The magnetic focusing of planar beam is easier comparative to spherical beam hence, this structure has been adopted for this particular device design. (author)

Microsatellite polymorphism in the heme oxygenase-1 gene promoter and the risk of atrial fibrillation in Taiwanese.

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Lung-An Hsu

Full Text Available Atrial fibrillation (AF is associated with increased oxidative stress. Emerging evidence suggests that heme oxygenase-1 (HO-1 is a potent antioxidant system against various oxidative stress-related diseases. The human HO-1 promoter has a GT-repeat length polymorphism that can determine the level of gene transcription.The aim of this study is to assess the role of the GT-repeat polymorphism in the promoter region of the HO-1 gene in Chinese-Taiwanese patients with AF.This study enrolled 200 AF patients and 240 controls, comparable for age and gender. In each subject, the length of GT-repeat polymorphism in the HO-1 promoter region was examined by polymerase chain reactions. The frequencies of long GT-repeat alleles (≧32 were significantly higher in AF patients than in controls. Multivariate analysis showed that the presence of long allele was significantly and independently associated with AF (odds ratio: 1.91, 95% CI 1.07-3.72; P = 0.028. Right atrial tissues from patients with chronic AF were investigated with immunoconfocal microscopy. Patients homozygous for shorter GT-repeat alleles exhibited greater HO-1 expression in their atria than those homozygous for longer alleles, which was reflected by less oxidative stress, myofibril degradation, and fibrosis in the atria of patients with shorter GT-repeat. In vitro, transient transfection assay in HL-1 atrial myocytes showed that the responsiveness of HO-1 transcriptional activity to tachypacing was inversely correlated with the length of the GT-repeats.Our results suggest that the HO-1 microsatellite polymorphism may contribute to the genetic background of AF in Chinese-Taiwanese patients.

Repeat polymorphisms in the Homo sapiens heme oxygenase-1 gene in diabetic and idiopathic gastroparesis.

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Simon J Gibbons

Full Text Available Idiopathic and diabetic gastroparesis in Homo sapiens cause significant morbidity. Etiology or risk factors have not been clearly identified. Failure to sustain elevated heme oxygenase-1 (HO1 expression is associated with delayed gastric emptying in diabetic mice and polymorphisms in the HO1 gene (HMOX1, NCBI Gene ID:3162 are associated with worse outcomes in other diseases.Our hypothesis was that longer polyGT alleles are more common in the HMOX1 genes of individuals with gastroparesis than in controls without upper gastrointestinal motility disorders.Repeat length was determined in genomic DNA. Controls with diabetes (84 type 1, 84 type 2 and without diabetes (n = 170 were compared to diabetic gastroparetics (99 type 1, 72 type 2 and idiopathic gastroparetics (n = 234. Correlations of repeat lengths with clinical symptom sub-scores on the gastroparesis cardinal symptom index (GCSI were done. Statistical analyses of short (32 repeat alleles and differences in allele length were used to test for associations with gastroparesis.The distribution of allele lengths was different between groups (P = 0.016. Allele lengths were longest in type 2 diabetics with gastroparesis (29.18±0.35, mean ± SEM and longer in gastroparetics compared to non-diabetic controls (28.50±0.14 vs 27.64±0.20 GT repeats/allele, P = 0.0008. Type 2 diabetic controls had longer alleles than non-diabetic controls. In all gastroparetic groups, allele lengths were longer in African Americans compared to other racial groups, differences in the proportion of African Americans in the groups accounted for the differences between gastroparetics and controls. Diabetic gastroparetics with 1 or 2 long alleles had worse GCSI nausea sub-scores (3.30±0.23 as compared to those with 0 long alleles (2.66±0.12, P = 0.022.Longer poly-GT repeats in the HMOX1 gene are more common in African Americans with gastroparesis. Nausea symptoms are worse in subjects with longer alleles.

Repeat polymorphisms in the Homo sapiens heme oxygenase-1 gene in diabetic and idiopathic gastroparesis.

Science.gov (United States)

Gibbons, Simon J; Grover, Madhusudan; Choi, Kyoung Moo; Wadhwa, Akhilesh; Zubair, Adeel; Wilson, Laura A; Wu, Yanhong; Abell, Thomas L; Hasler, William L; Koch, Kenneth L; McCallum, Richard W; Nguyen, Linda A B; Parkman, Henry P; Sarosiek, Irene; Snape, William J; Tonascia, James; Hamilton, Frank A; Pasricha, Pankaj J; Farrugia, Gianrico

2017-01-01

Idiopathic and diabetic gastroparesis in Homo sapiens cause significant morbidity. Etiology or risk factors have not been clearly identified. Failure to sustain elevated heme oxygenase-1 (HO1) expression is associated with delayed gastric emptying in diabetic mice and polymorphisms in the HO1 gene (HMOX1, NCBI Gene ID:3162) are associated with worse outcomes in other diseases. Our hypothesis was that longer polyGT alleles are more common in the HMOX1 genes of individuals with gastroparesis than in controls without upper gastrointestinal motility disorders. Repeat length was determined in genomic DNA. Controls with diabetes (84 type 1, 84 type 2) and without diabetes (n = 170) were compared to diabetic gastroparetics (99 type 1, 72 type 2) and idiopathic gastroparetics (n = 234). Correlations of repeat lengths with clinical symptom sub-scores on the gastroparesis cardinal symptom index (GCSI) were done. Statistical analyses of short (32) repeat alleles and differences in allele length were used to test for associations with gastroparesis. The distribution of allele lengths was different between groups (P = 0.016). Allele lengths were longest in type 2 diabetics with gastroparesis (29.18±0.35, mean ± SEM) and longer in gastroparetics compared to non-diabetic controls (28.50±0.14 vs 27.64±0.20 GT repeats/allele, P = 0.0008). Type 2 diabetic controls had longer alleles than non-diabetic controls. In all gastroparetic groups, allele lengths were longer in African Americans compared to other racial groups, differences in the proportion of African Americans in the groups accounted for the differences between gastroparetics and controls. Diabetic gastroparetics with 1 or 2 long alleles had worse GCSI nausea sub-scores (3.30±0.23) as compared to those with 0 long alleles (2.66±0.12), P = 0.022. Longer poly-GT repeats in the HMOX1 gene are more common in African Americans with gastroparesis. Nausea symptoms are worse in subjects with longer alleles.

Repeat polymorphisms in the Homo sapiens heme oxygenase-1 gene in diabetic and idiopathic gastroparesis

Science.gov (United States)

Gibbons, Simon J.; Grover, Madhusudan; Choi, Kyoung Moo; Wadhwa, Akhilesh; Zubair, Adeel; Wilson, Laura A.; Wu, Yanhong; Abell, Thomas L.; Hasler, William L.; Koch, Kenneth L.; McCallum, Richard W.; Nguyen, Linda A. B.; Parkman, Henry P.; Sarosiek, Irene; Snape, William J.; Tonascia, James; Hamilton, Frank A.; Pasricha, Pankaj J.

2017-01-01

Background Idiopathic and diabetic gastroparesis in Homo sapiens cause significant morbidity. Etiology or risk factors have not been clearly identified. Failure to sustain elevated heme oxygenase-1 (HO1) expression is associated with delayed gastric emptying in diabetic mice and polymorphisms in the HO1 gene (HMOX1, NCBI Gene ID:3162) are associated with worse outcomes in other diseases. Aim Our hypothesis was that longer polyGT alleles are more common in the HMOX1 genes of individuals with gastroparesis than in controls without upper gastrointestinal motility disorders. Methods Repeat length was determined in genomic DNA. Controls with diabetes (84 type 1, 84 type 2) and without diabetes (n = 170) were compared to diabetic gastroparetics (99 type 1, 72 type 2) and idiopathic gastroparetics (n = 234). Correlations of repeat lengths with clinical symptom sub-scores on the gastroparesis cardinal symptom index (GCSI) were done. Statistical analyses of short (32) repeat alleles and differences in allele length were used to test for associations with gastroparesis. Results The distribution of allele lengths was different between groups (P = 0.016). Allele lengths were longest in type 2 diabetics with gastroparesis (29.18±0.35, mean ± SEM) and longer in gastroparetics compared to non-diabetic controls (28.50±0.14 vs 27.64±0.20 GT repeats/allele, P = 0.0008). Type 2 diabetic controls had longer alleles than non-diabetic controls. In all gastroparetic groups, allele lengths were longer in African Americans compared to other racial groups, differences in the proportion of African Americans in the groups accounted for the differences between gastroparetics and controls. Diabetic gastroparetics with 1 or 2 long alleles had worse GCSI nausea sub-scores (3.30±0.23) as compared to those with 0 long alleles (2.66±0.12), P = 0.022. Conclusions Longer poly-GT repeats in the HMOX1 gene are more common in African Americans with gastroparesis. Nausea symptoms are worse in

Electron energy distributions and electron impact source functions in Ar/N{sub 2} inductively coupled plasmas using pulsed power

Energy Technology Data Exchange (ETDEWEB)

Logue, Michael D., E-mail: mdlogue@umich.edu; Kushner, Mark J., E-mail: mjkush@umich.edu [Department of Electrical Engineering and Computer Science, University of Michigan, 1301 Beal Ave., Ann Arbor, Michigan 48109-2122 (United States)

2015-01-28

In plasma materials processing, such as plasma etching, control of the time-averaged electron energy distributions (EEDs) in the plasma allows for control of the time-averaged electron impact source functions of reactive species in the plasma and their fluxes to surfaces. One potential method for refining the control of EEDs is through the use of pulsed power. Inductively coupled plasmas (ICPs) are attractive for using pulsed power in this manner because the EEDs are dominantly controlled by the ICP power as opposed to the bias power applied to the substrate. In this paper, we discuss results from a computational investigation of EEDs and electron impact source functions in low pressure (5–50 mTorr) ICPs sustained in Ar/N{sub 2} for various duty cycles. We find there is an ability to control EEDs, and thus source functions, by pulsing the ICP power, with the greatest variability of the EEDs located within the skin depth of the electromagnetic field. The transit time of hot electrons produced in the skin depth at the onset of pulse power produces a delay in the response of the EEDs as a function of distance from the coils. The choice of ICP pressure has a large impact on the dynamics of the EEDs, whereas duty cycle has a small influence on time-averaged EEDs and source functions.

Retuning Rieske-type Oxygenases to Expand Substrate Range

Energy Technology Data Exchange (ETDEWEB)

Mohammadi, Mahmood; Viger, Jean-François; Kumar, Pravindra; Barriault, Diane; Bolin, Jeffrey T.; Sylvestre, Michel (INRS); (Purdue)

2012-09-17

Rieske-type oxygenases are promising biocatalysts for the destruction of persistent pollutants or for the synthesis of fine chemicals. In this work, we explored pathways through which Rieske-type oxygenases evolve to expand their substrate range. BphAE{sub p4}, a variant biphenyl dioxygenase generated from Burkholderia xenovorans LB400 BphAE{sub LB400} by the double substitution T335A/F336M, and BphAE{sub RR41}, obtained by changing Asn{sup 338}, Ile{sup 341}, and Leu{sup 409} of BphAE{sub p4} to Gln{sup 338}, Val{sup 341}, and Phe{sup 409}, metabolize dibenzofuran two and three times faster than BphAE{sub LB400}, respectively. Steady-state kinetic measurements of single- and multiple-substitution mutants of BphAE{sub LB400} showed that the single T335A and the double N338Q/L409F substitutions contribute significantly to enhanced catalytic activity toward dibenzofuran. Analysis of crystal structures showed that the T335A substitution relieves constraints on a segment lining the catalytic cavity, allowing a significant displacement in response to dibenzofuran binding. The combined N338Q/L409F substitutions alter substrate-induced conformational changes of protein groups involved in subunit assembly and in the chemical steps of the reaction. This suggests a responsive induced fit mechanism that retunes the alignment of protein atoms involved in the chemical steps of the reaction. These enzymes can thus expand their substrate range through mutations that alter the constraints or plasticity of the catalytic cavity to accommodate new substrates or that alter the induced fit mechanism required to achieve proper alignment of reaction-critical atoms or groups.

High efficiency inductive output tubes with intense annular electron beams

Science.gov (United States)

Appanam Karakkad, J.; Matthew, D.; Ray, R.; Beaudoin, B. L.; Narayan, A.; Nusinovich, G. S.; Ting, A.; Antonsen, T. M.

2017-10-01

For mobile ionospheric heaters, it is necessary to develop highly efficient RF sources capable of delivering radiation in the frequency range from 3 to 10 MHz with an average power at a megawatt level. A promising source, which is capable of offering these parameters, is a grid-less version of the inductive output tube (IOT), also known as a klystrode. In this paper, studies analyzing the efficiency of grid-less IOTs are described. The basic trade-offs needed to reach high efficiency are investigated. In particular, the trade-off between the peak current and the duration of the current micro-pulse is analyzed. A particle in the cell code is used to self-consistently calculate the distribution in axial and transverse momentum and in total electron energy from the cathode to the collector. The efficiency of IOTs with collectors of various configurations is examined. It is shown that the efficiency of IOTs can be in the 90% range even without using depressed collectors.

Review of induction LINACS

International Nuclear Information System (INIS)

Faltens, A.; Keefe, D.

1981-10-01

There has been a recent upsurge of activity in the field of induction linacs, with several new machines becoming operational and others in the design stages. The performance levels of electron machines have reached 10's of kiloamps of current and will soon reach 10's of MeV's of energy. Acceleration of ion current has been demonstrated, and the study of a 10 GeV heavy ion induction linac for ICF continues. The operating principles of induction linacs are reviewed with the emphasis on design choices which are important for increasing the maximum beam currents

Review of induction linacs

International Nuclear Information System (INIS)

Faltens, A.; Keefe, D.

1982-01-01

There has been a recent upsurge of activity in the field of induction linacs, with several new machines becoming operational and others in the design stages. The performance levels of electron machines have reached 10's of kiloamps of current and will soon reach 10's of MeV's of energy. Acceleration of several kiloamps of ion current has been demonstrated, and the study of a 10 GeV heavy ion induction linac for ICF continues. The operating principles of induction linacs are reviewed with the emphasis on design choices which are important for increasing the maximum beam currents

Camel Milk Modulates the Expression of Aryl Hydrocarbon Receptor-Regulated Genes, Cyp1a1, Nqo1, and Gsta1, in Murine hepatoma Hepa 1c1c7 Cells

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Hesham M. Korashy

2012-01-01

Full Text Available There is a traditional belief in the Middle East that camel milk may aid in prevention and treatment of numerous cases of cancer yet, the exact mechanism was not investigated. Therefore, we examined the ability of camel milk to modulate the expression of a well-known cancer-activating gene, Cytochrome P450 1a1 (Cyp1a1, and cancer-protective genes, NAD(PH:quinone oxidoreductase 1 (Nqo1 and glutathione S-transferase a1 (Gsta1, in murine hepatoma Hepa 1c1c7 cell line. Our results showed that camel milk significantly inhibited the induction of Cyp1a1 gene expression by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD, the most potent Cyp1a1 inducer and known carcinogenic chemical, at mRNA, protein, and activity levels in a concentration-dependent manner. In addition, camel milk significantly decreased the xenobiotic responsive element (XRE-dependent luciferase activity, suggesting a transcriptional mechanism is involved. Furthermore, this inhibitory effect of camel milk was associated with a proportional increase in heme oxygenase 1. On the other hand, camel milk significantly induced Nqo1 and Gsta1 mRNA expression level in a concentration-dependent fashion. The RNA synthesis inhibitor, actinomycin D, completely blocked the induction of Nqo1 mRNA by camel milk suggesting the requirement of de novo RNA synthesis through a transcriptional mechanism. In conclusion, camel milk modulates the expression of Cyp1a1, Nqo1, and Gsta1 at the transcriptional and posttranscriptional levels.

[Gene transfer-induced human heme oxygenase-1 over-expression protects kidney from ischemia-reperfusion injury in rats].

Science.gov (United States)

Lü, Jin-xing; Yan, Chun-yin; Pu, Jin-xian; Hou, Jian-quan; Yuan, He-xing; Ping, Ji-gen

2010-12-14

To study the protection of gene transfer-induced human heme oxygenase-1 over-expression against renal ischemia reperfusion injury in rats. The model of kidney ischemia-reperfusion injury was established with Sprague-Dawley rats. In the therapy group (n=18), the left kidney was perfused and preserved with Ad-hHO-1 at 2.5×10(9) pfu/1.0 ml after flushed with 0-4°C HC-A organ storage solution via donor renal aorta. The rats in control groups were perfused with 0.9% saline solution (n=12) or the vector carrying no interest gene Ad-EGFP 2.5×10(9) pfu/1.0 ml (n=18) instead of Ad-hHO-1. BUN and Cr in serum were measured by slide chemical methods. The kidney samples of rats were harvested for assay of histology, immunohistochemistry and quantification of HO enzymatic activity. Apoptosis cells in the kidney were measured by TUNEL. Ad-hHO-1 via donor renal aorta could transfect renal cells of rats effectively, enzymatic activity of HO in treated group [(1.62±0.07) nmol×mg(-1)×min(-1)] is higher than in control groups treated with saline solution team [(1.27±0.07) nmol×mg(-1)×min(-1)] and vector EGFP team [(1.22±0.06) nmol×mg(-1)×min(-1)] (PhHO-1 expressed hHO-1 in kidneys at a high level. Corresponding to this, the level of BUN and Cr, as well as the number of apoptosis cells, were decreased, and the damage in histology by HE staining was ameliorated. Over-expression of human HO-1 can protect the kidney from ischemia/reperfusion injury in rats.

EXPRESSION AND CHARACTERIZATION OF FULL-LENGTH HUMAN HEME OXYGENASE-1: PRESENCE OF INTACT MEMBRANE-BINDING REGION LEADS TO INCREASED BINDING AFFINITY FOR NADPH-CYTOCHROME P450 REDUCTASE

Science.gov (United States)

Huber, Warren J.; Backes, Wayne L.

2009-01-01

Heme oxygenase (HO) is the chief regulatory enzyme in the oxidative degradation of heme to biliverdin. In the process of heme degradation, this NADPH and cytochrome P450 reductase (CPR)-dependent oxidation of heme also releases free iron and carbon monoxide. Much of the recent research involving heme oxygenase is done using a 30-kDa soluble form of the enzyme, which lacks the membrane binding region (C-terminal 23 amino acids). The goal of this study was to express and purify a full-length human HO-1 (hHO-1) protein; however, due to the lability of the full-length form, a rapid purification procedure was required. This was accomplished by use of a GST-tagged hHO-1 construct. Although the procedure permitted the generation of a full-length HO-1, this form was contaminated with a 30-kDa degradation product that could not be eliminated. Therefore, we attempted to remove a putative secondary thrombin cleavage site by a conservative mutation of amino acid 254, which replaces lysine with arginine. This mutation allowed the expression and purification of a full length hHO-1 protein. Unlike wild-type HO-1, the K254R mutant could be purified to a single 32-kDa protein capable of degrading heme at the same rate as the wild-type enzyme. The K254R full-length form had a specific activity of ~200–225 nmol bilirubin hr−1nmol−1 HO-1 as compared to ~140–150 nmol bilirubin hr−1nmol−1 for the WT form, which contains the 30-kDa contaminant. This is a 2–3-fold increase from the previously reported soluble 30-kDa HO-1, suggesting that the C-terminal 23 amino acids are essential for maximal catalytic activity. Because the membrane spanning domain is present, the full-length hHO-1 has the potential to incorporate into phospholipid membranes, which can be reconstituted at known concentrations, in combination with other ER-resident enzymes. PMID:17915953

Electron inductive effects in the radiolysis of substituted phenylboronic acid solutions

International Nuclear Information System (INIS)

Brown, B.J.; Fitch, P.G.; Sangster, D.F.

1976-01-01

The pulse radiolysis of aqueous solutions of phenylboronic acid PhB(OH) 2 and its m-nitro and m-amino derivatives has been investigated. The transient optical absorption spectra indicate the presence of three intermediate species absorbing with independent maxima at 297, 317 and 400 nm. The 297-nm band has been assigned to the anion formed in an electron capture reaction, i.e. PhB(OH) 2 +epsilonsub(aq) - → PhB(OH) 2 - and the 317-nm band to cyclohexadienyl radicals formed from OH and H attack on OhB(OH) 2 . Hydroxyphenylboronic acid has been identified as the major stable radiation product. For each of the systems studied the respective yield and reactivity of observed intermediate species can be interpreted relative to the inductive effects of substituent groups in agreement with the Hammett relationship. (author)

Isolating a cytoprotective compound from Ganoderma tsugae: effects on induction of Nrf-2-related genes in endothelial cells.

Science.gov (United States)

Wei, Yu-Shan; Wung, Being-Sun; Lin, Yuan-Chun; Hsieh, Chia-Wen

2009-08-01

Ganoderma tsugae is a medicinal fungus with several biological activities. It has long been used as a folk remedy for the promotion of health and longevity in China and other oriental countries. Here, a bioactive fraction of G. tsugae was progressively purified to be enriched in the activity of cytoprotective enzymes. The highest bioactivity was detected in the 20% EtOH-precipitated fraction, which was prepared from submerged fermentation filtrate of G. tsugae. Following further purification by gel filtration chromatography and acetone extraction, the most bioactive fraction, F5-2, was identified as a peptidoglycan-like compound. Extracts of G. tsugae (F5-2) induced heme oxygenase-1 (HO-1) and thioredoxin reductase-1 (TrxR1) expression in endothelial cells by increasing NF-E2-related factor-2 (Nrf2) nuclear translocation. Pretreatment with F5-2 increased intracellular glutathione (GSH) and protected against H(2)O(2), suggesting that induction of these antioxidant enzymes is important in protection against oxidative stress. Hence the bioactive peptidoglycan-like compound from G. tsugae might protect endothelial cells.

Induction of labor in a contemporary obstetric cohort.

Science.gov (United States)

Laughon, S Katherine; Zhang, Jun; Grewal, Jagteshwar; Sundaram, Rajeshwari; Beaver, Julie; Reddy, Uma M

2012-06-01

We sought to describe details of labor induction, including precursors and methods, and associated vaginal delivery rates. This was a retrospective cohort study of 208,695 electronic medical records from 19 hospitals across the United States, 2002 through 2008. Induction occurred in 42.9% of nulliparas and 31.8% of multiparas and elective or no recorded indication for induction at term occurred in 35.5% and 44.1%, respectively. Elective induction at term in multiparas was highly successful (vaginal delivery 97%) compared to nulliparas (76.2%). For all precursors, cesarean delivery was more common in nulliparas in the latent compared to active phase of labor. Regardless of method, vaginal delivery rates were higher with a ripe vs unripe cervix, particularly for multiparas (86.6-100%). Induction of labor was a common obstetric intervention. Selecting appropriate candidates and waiting longer for labor to progress into the active phase would make an impact on decreasing the national cesarean delivery rate. Published by Mosby, Inc.

Inflammasome and Fas-Mediated IL-1β Contributes to Th17/Th1 Cell Induction in Pathogenic Bacterial Infection In Vivo.

Science.gov (United States)

Uchiyama, Ryosuke; Yonehara, Shin; Taniguchi, Shun'ichiro; Ishido, Satoshi; Ishii, Ken J; Tsutsui, Hiroko

2017-08-01

CD4 + Th cells play crucial roles in orchestrating immune responses against pathogenic microbes, after differentiating into effector subsets. Recent research has revealed the importance of IFN-γ and IL-17 double-producing CD4 + Th cells, termed Th17/Th1 cells, in the induction of autoimmune and inflammatory diseases. In addition, Th17/Th1 cells are involved in the regulation of infection caused by the intracellular bacterium Mycobacterium tuberculosis in humans. However, the precise mechanism of Th17/Th1 induction during pathogen infection is unclear. In this study, we showed that the inflammasome and Fas-dependent IL-1β induces Th17/Th1 cells in mice, in response to infection with the pathogenic intracellular bacterium Listeria monocytogenes In the spleens of infected wild-type mice, Th17/Th1 cells were induced, and expressed T-bet and Rorγt. In Pycard -/- mice, which lack the adaptor molecule of the inflammasome (apoptosis-associated speck-like protein containing a caspase recruitment domain), Th17/Th1 induction was abolished. In addition, the Fas-mediated IL-1β production was required for Th17/Th1 induction during bacterial infection: Th17/Th1 induction was abolished in Fas -/- mice, whereas supplementation with recombinant IL-1β restored Th17/Th1 induction via IL-1 receptor 1 (IL-1R1), and rescued the mortality of Fas -/- mice infected with Listeria IL-1R1, but not apoptosis-associated speck-like protein containing a caspase recruitment domain or Fas on T cells, was required for Th17/Th1 induction, indicating that IL-1β stimulates IL-1R1 on T cells for Th17/Th1 induction. These results indicate that IL-1β, produced by the inflammasome and Fas-dependent mechanisms, contributes cooperatively to the Th17/Th1 induction during bacterial infection. This study provides a deeper understanding of the molecular mechanisms underlying Th17/Th1 induction during pathogenic microbial infections in vivo. Copyright © 2017 by The American Association of Immunologists

Design of electron detection system for pulse electron irradiator

International Nuclear Information System (INIS)

Anjar Anggraini H; Agus Purwadi; Lely Susita RM; Bambang Siswanto; Agus Wijayanto

2016-01-01

Design of electron detection system for pulse electron irradiator has been conducted on the Plasma Cathode Electron Source by Rogowski coil technique. Rogowski coil has ability to capture the induced magnetic field of the electric current, subsequent induced magnetic field will provide voltage after passing integrator. This diagnostic used combination of copper wire, ferrite and RC integrator. The design depends on the pulse width and the value of plasma current that passes through the coil, thus the number of windings, coil area and integrator can be designed. For plasma spots current of IDPS expected to be 10 A and pulse width 10 μs the Rogowski coil using MnZn ferrite with inductance L = 0.275 mH and permeability μr = 200 H/m. For the current of plasma arc ADPS expected to be 100 A and pulse width 100 μs by using inductance L=1.9634 mH and permeability μr = 6256 H/m. Electron current in extraction system expected to be 30 A and pulse width 100 μs the Rogowski coil using inductance L=51.749 mH and permeability μr= 4987 H/m. Design integrator used is the type of RC integrator. (author)

Solution 1H NMR investigation of the active site molecular and electronic structures of substrate-bound, cyanide-inhibited HmuO, a bacterial heme oxygenase from Corynebacterium diphtheriae.

Science.gov (United States)

Li, Yiming; Syvitski, Ray T; Chu, Grace C; Ikeda-Saito, Masao; Mar, Gerd N La

2003-02-28

The molecular structure and dynamic properties of the active site environment of HmuO, a heme oxygenase (HO) from the pathogenic bacterium Corynebacterium diphtheriae, have been investigated by (1)H NMR spectroscopy using the human HO (hHO) complex as a homology model. It is demonstrated that not only the spatial contacts among residues and between residues and heme, but the magnetic axes that can be related to the direction and magnitude of the steric tilt of the FeCN unit are strongly conserved in the two HO complexes. The results indicate that very similar contributions of steric blockage of several meso positions and steric tilt of the attacking ligand are operative. A distal H-bond network that involves numerous very strong H-bonds and immobilized water molecules is identified in HmuO that is analogous to that previously identified in hHO (Li, Y., Syvitski, R. T., Auclair, K., Wilks, A., Ortiz de Montellano, P. R., and La Mar, G. N. (2002) J. Biol. Chem. 277, 33018-33031). The NMR results are completely consistent with the very recent crystal structure of the HmuO.substrate complex. The H-bond network/ordered water molecules are proposed to orient the distal water molecule near the catalytically key Asp(136) (Asp(140) in hHO) that stabilizes the hydroperoxy intermediate. The dynamic stability of this H-bond network in HmuO is significantly greater than in hHO and may account for the slower catalytic rate in bacterial HO compared with mammalian HO.

Thiazolidinediones inhibit TNFα induction of PAI-1 independent of PPARγ activation

International Nuclear Information System (INIS)

Liu, H.B.; Hu, Y.S.; Medcalf, R.L.; Simpson, R.W.; Dear, A.E.

2005-01-01

Increased plasminogen activator inhibitor type 1 (PAI-1) levels are observed in endothelial cells stimulated by tumour necrosis factor α (TNFα). Thiazolidinediones (TZDs) may inhibit elevated endothelial cell PAI-1 accounting, in part, for the putative atheroprotective effects of TZDs. In an endothelial cell line, Rosiglitazone (RG) and Pioglitazone (PG) inhibited induction of PAI-1 by TNFα. The specific peroxisome proliferator-activated receptor γ (PPARγ) inhibitor, SR-202, failed to modulate this effect. RG also inhibited the effect of TNFα on a reporter gene construct harbouring the proximal PAI-1 promoter and PAI-1 mRNA in cells co-transfected with a dominant-negative PPARγ construct. RG and PG attenuated TNFα-mediated induction of trans-acting factor(s) Nur77/Nurr1 and binding of nuclear proteins (NP) to the cis-acting element (NBRE). SR-202 failed to modulate these effects. The observations suggest TZDs inhibit TNFα-mediated PAI-1 induction independent of inducible PPARγ activation and this may involve in the modulation of Nur77/Nurr1 expression and NP binding to the PAI-1 NBRE

Comparison of the crystal structure and function to wild-type and His25Ala mutant human heme oxygenase-1.

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Zhou, Wen-Pu; Zhong, Wen-Wei; Zhang, Xue-Hong; Ding, Jian-Ping; Zhang, Zi-Li; Xia, Zhen-Wei

2009-03-01

Human heme oxygenase-1 (hHO-1) is a rate-limiting enzyme in heme metabolism. It regulates serum bilirubin level. Site-directed mutagenesis studies indicate that the proximal residue histidine 25 (His25) plays a key role in hHO-1 activity. A highly purified hHO-1 His25Ala mutant was generated and crystallized with a new expression system. The crystal structure of the mutant was determined by X-ray diffraction technology and molecular replacement at the resolution of 2.8 A, and the model of hHO-1 His25Ala mutant was refined. The final crystallographic and free R factors were 0.245 and 0.283, respectively. The standard bond length deviation was 0.007 A, and the standard bond angle deviation was 1.3 degrees . The mutation of His25 to Ala led to an empty pocket underneath the ferric ion in the heme, leading to loss of binding iron ligand. Although this did not cause an overall structural change, the enzymatic activity of the mutant hHO-1 was reduced by 90%. By supplementing imidazole, the HO-1 activity was restored approximately 90% to its normal level. These data suggest that Ala25 remains unchanged in the structure compared to His25, but the important catalytic function of hHO-1 is lost. Thus, it appears that His25 is a crucial residue for proper hHO-1 catalysis.

Linear inductive voltage adders (IVA) for advanced hydrodynamic radiography

International Nuclear Information System (INIS)

Mazarakis, M.G.; Boyes, J.D.; Johnson, D.L.

1998-01-01

The electron beam which drifts through the multiple cavities of conventional induction linacs (LIA) is replaced in an IVA by a cylindrical metal conductor which extends along the entire length of the device and effectuates the addition of the accelerator cavity voltages. In the approach to radiography, the linear inductive voltage adder drives a magnetically immersed electron diode with a millimeter diameter cathode electrode and a planar anode/bremsstrahlung converter. Both anode and cathode electrodes are immersed in a strong (15--50 T) solenoidal magnetic field. The electron beam cross section is approximately of the same size as the cathode needle and generates a similar size, very intense x-ray beam when it strikes the anode converter. An IVA driven diode can produce electron beams of equal size and energy as a LIA but with much higher currents (40--50 kA versus 4--5 kA), simpler hardware and thus lower cost. The authors present here first experimental validations of the technology utilizing HERMES 3 and SABRE IVA accelerators. The electron beam voltage and current were respectively of the order of 10 MV and 40 kA. X-ray doses of up to 1 kR at sign 1 m and spot sizes as small as 1.7 mm (at 200 R doses) were measured

Alpha-7 nicotinic acetylcholine receptor agonist treatment in a rat model of Huntington's disease and involvement of heme oxygenase-1

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Laura Foucault-Fruchard

2018-01-01

Full Text Available Neuroinflammation is a common element involved in the pathophysiology of neurodegenerative diseases. We recently reported that repeated alpha-7 nicotinic acetylcholine receptor (α7nAChR activations by a potent agonist such as PHA 543613 in quinolinic acid-injured rats exhibited protective effects on neurons. To further investigate the underlying mechanism, we established rat models of early-stage Huntington's disease by injection of quinolinic acid into the right striatum and then intraperitoneally injected 12 mg/kg PHA 543613 or sterile water, twice a day during 4 days. Western blot assay results showed that the expression of heme oxygenase-1 (HO-1, the key component of the cholinergic anti-inflammatory pathway, in the right striatum of rat models of Huntington's disease subjected to intraperitoneal injection of PHA 543613 for 4 days was significantly increased compared to the control rats receiving intraperitoneal injection of sterile water, and that the increase in HO-1 expression was independent of change in α7nAChR expression. These findings suggest that HO-1 expression is unrelated to α7nAChR density and the increase in HO-1 expression likely contributes to α7nAChR activation-related neuroprotective effect in early-stage Huntington's disease.

Involvement of Heme Oxygenase-1 Participates in Anti-Inflammatory and Analgesic Effects of Aqueous Extract of Hibiscus taiwanensis.

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Liu, Shu-Ling; Deng, Jeng-Shyan; Chiu, Chuan-Sung; Hou, Wen-Chi; Huang, Shyh-Shyun; Lin, Wang-Ching; Liao, Jung-Chun; Huang, Guan-Jhong

2012-01-01

Anti-inflammatory effects of the aqueous extract of Hibiscus taiwanensis (AHT) were used in lipopolysaccharide (LPS-)stimulated mouse macrophage RAW264.7 cells and carrageenan (Carr-)induced mouse paw edema model. When RAW264.7 macrophages were treated with AHT together with LPS, a concentration-dependent inhibition of nitric oxide (NO), tumor necrosis factor (TNF-α), and prostaglandin E2 (PGE(2)) levels productions were detected. Western blotting revealed that AHT blocked protein expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), and elevated heme oxygenase-1 (HO-1), significantly. In the animal test, AHT decreased the paw edema at the 4th and the 5th h after Carr administration, and it increased the activities of catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) in the paw tissue. We also demonstrated AHT decreased the NO, TNF-α, and PGE2 levels on the serum level at the 5th h after the Carr injection. Western blotting revealed that AHT decreased Carr-induced iNOS, and COX-2, and increased HO-1 expressions at the 5th h in the edema paw. These findings demonstrated that AHT has excellent anti-inflammatory activities in vitro and in vivo and thus it has great potential to be used as a source for natural health products.

Involvement of Heme Oxygenase-1 Participates in Anti-Inflammatory and Analgesic Effects of Aqueous Extract of Hibiscus taiwanensis

Directory of Open Access Journals (Sweden)

Shu-Ling Liu

2012-01-01

Full Text Available Anti-inflammatory effects of the aqueous extract of Hibiscus taiwanensis (AHT were used in lipopolysaccharide (LPS-stimulated mouse macrophage RAW264.7 cells and carrageenan (Carr-induced mouse paw edema model. When RAW264.7 macrophages were treated with AHT together with LPS, a concentration-dependent inhibition of nitric oxide (NO, tumor necrosis factor (TNF-α, and prostaglandin E2 (PGE2 levels productions were detected. Western blotting revealed that AHT blocked protein expression of inducible nitric oxide synthase (iNOS and cyclooxygenase-2 (COX-2, and elevated heme oxygenase-1 (HO-1, significantly. In the animal test, AHT decreased the paw edema at the 4th and the 5th h after Carr administration, and it increased the activities of catalase (CAT, superoxide dismutase (SOD, and glutathione peroxidase (GPx in the paw tissue. We also demonstrated AHT decreased the NO, TNF-α, and PGE2 levels on the serum level at the 5th h after the Carr injection. Western blotting revealed that AHT decreased Carr-induced iNOS, and COX-2, and increased HO-1 expressions at the 5th h in the edema paw. These findings demonstrated that AHT has excellent anti-inflammatory activities in vitro and in vivo and thus it has great potential to be used as a source for natural health products.

Sulfur Oxygenase Reductase (Sor) in the Moderately Thermoacidophilic Leaching Bacteria: Studies in Sulfobacillus thermosulfidooxidans and Acidithiobacillus caldus

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Janosch, Claudia; Remonsellez, Francisco; Sand, Wolfgang; Vera, Mario

2015-01-01

The sulfur oxygenase reductase (Sor) catalyzes the oxygen dependent disproportionation of elemental sulfur, producing sulfite, thiosulfate and sulfide. Being considered an “archaeal like” enzyme, it is also encoded in the genomes of some acidophilic leaching bacteria such as Acidithiobacillus caldus, Acidithiobacillus thiooxidans, Acidithiobacillus ferrivorans and Sulfobacillus thermosulfidooxidans, among others. We measured Sor activity in crude extracts from Sb. thermosulfidooxidans DSM 9293T. The optimum temperature for its oxygenase activity was achieved at 75 °C, confirming the “thermophilic” nature of this enzyme. Additionally, a search for genes probably involved in sulfur metabolism in the genome sequence of Sb. thermosulfidooxidans DSM 9293T was done. Interestingly, no sox genes were found. Two sor genes, a complete heterodisulfidereductase (hdr) gene cluster, three tetrathionate hydrolase (tth) genes, three sulfide quinonereductase (sqr), as well as the doxD component of a thiosulfate quinonereductase (tqo) were found. Seven At. caldus strains were tested for Sor activity, which was not detected in any of them. We provide evidence that an earlier reported Sor activity from At. caldus S1 and S2 strains most likely was due to the presence of a Sulfobacillus contaminant. PMID:27682113

Bach1 gene ablation reduces steatohepatitis in mouse MCD diet model.

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Inoue, Motoki; Tazuma, Susumu; Kanno, Keishi; Hyogo, Hideyuki; Igarashi, Kazuhiko; Chayama, Kazuaki

2011-03-01

Bach1 is a transcriptional repressor of heme oxygenase-1 (HO-1, a.k.a. HSP-32), which is an inducible enzyme and has anti-oxidation/anti-inflammatory properties shown in various models of organ injuries. Since oxidative stress plays a pivotal role in the pathogenesis of nonalcoholic steatohepatitis (NASH), HO-1 induction would be expected to prevent the development of NASH. In this study, we investigated the influence of Bach1 ablation in mice on the progression of NASH in methionine-choline deficient (MCD) diet model. Bach1 ablation resulted in significant induction of HO-1 mRNA and its activity in the liver. When fed MCD diet, Bach1(-/-) mice exhibited negligible hepatic steatosis compared to pronounced steatohepatitis in wild type mice with 6-fold increase in hepatic triglyceride content. Whereas feeding of MCD diet decreased mRNA expressions of peroxisome proliferator-activated receptor (PPAR) α and microsomal triglyceride transfer protein (MTP) in wild type mice, there were no change in Bach1(-/-) mice. In addition, hepatic concentration of malondialdehyde (MDA), a biomarker for oxidative stress as well as plasma alanine aminotransferase (ALT) was significantly lower in Bach1(-/-) mice. These findings suggest that Bach1 ablation exerts hepatoprotective effect against steatohepatitis presumably via HO-1 induction and may be a potential therapeutic target.

Eriodictyol Protects Endothelial Cells against Oxidative Stress-Induced Cell Death through Modulating ERK/Nrf2/ARE-Dependent Heme Oxygenase-1 Expression.

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Lee, Seung Eun; Yang, Hana; Son, Gun Woo; Park, Hye Rim; Park, Cheung-Seog; Jin, Young-Ho; Park, Yong Seek

2015-06-26

The pathophysiology of cardiovascular diseases is complex and may involve oxidative stress-related pathways. Eriodictyol is a flavonoid present in citrus fruits that demonstrates anti-inflammatory, anti-cancer, neurotrophic, and antioxidant effects in a range of pathophysiological conditions including vascular diseases. Because oxidative stress plays a key role in the pathogenesis of cardiovascular disease, the present study was designed to verify whether eriodictyol has therapeutic potential. Upregulation of heme oxygenase-1 (HO-1), a phase II detoxifying enzyme, in endothelial cells is considered to be helpful in cardiovascular disease. In this study, human umbilical vein endothelial cells (HUVECs) treated with eriodictyol showed the upregulation of HO-1 through extracellular-regulated kinase (ERK)/nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant response element (ARE) signaling pathways. Further, eriodictyol treatment provided protection against hydrogen peroxide-provoked cell death. This protective effect was eliminated by treatment with a specific inhibitor of HO-1 and RNA interference-mediated knockdown of HO-1 expression. These data demonstrate that eriodictyol induces ERK/Nrf2/ARE-mediated HO-1 upregulation in human endothelial cells, which is directly associated with its vascular protection against oxidative stress-related endothelial injury, and propose that targeting the upregulation of HO-1 is a promising approach for therapeutic intervention in cardiovascular disease.

The Anti-Inflammatory Effects of Dimethyl Fumarate in Astrocytes Involve Glutathione and Haem Oxygenase-1

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Shao Xia Lin

2011-03-01

Full Text Available DMF (dimethyl fumarate exerts anti-inflammatory and prometabolic effects in a variety of cell types, and a formulation (BG-12 is being evaluated for monotherapy in multiple sclerosis patients. DMF modifies glutathione (GSH levels that can induce expression of the anti-inflammatory protein HO-1 (haem oxygenase-1. In primary astrocytes and C6 glioma cells, BG-12 dose-dependently suppressed nitrite production induced by either LI [LPS (lipopolysaccharide at 1 μg/ml plus IFNγ (interferon γ at 20 units/ml] or a mixture of proinflammatory cytokines, with greater efficacy in C6 cells. BG-12 reduced NOS2 (nitric oxide synthase 2 mRNA levels and activation of a NOS2 promoter, reduced nuclear levels of NF-κB (nuclear factor κB p65 subunit and attenuated loss of |κBα (inhibitory κBα in both cell types, although with greater effects in astrocytes. In astrocytes, LI decreased mRNA levels for GSHr (GSH reductase and GCL (c-glutamylcysteine synthetase, and slightly suppressed GSHs (GSH synthetase mRNAs. Co-treatment with BG-12 prevented those decreased and increased levels above control values. In contrast, LI reduced GSHp (GSH peroxidase and GCL in C6 cells, and BG-12 had no effect on those levels. BG-12 increased nuclear levels of Nrf2 (nuclear factor-erythroid 2 p45 subunit-related factor 2, an inducer of GSH-related enzymes, in astrocytes but not C6 cells. In astrocytes, GSH was decreased by BG-12 at 2 h and increased at 24 h. Prior depletion of GSH using buthionine-sulfoximine increased the ability of BG-12 to reduce nitrites. In astrocytes, BG-12 increased HO-1 mRNA levels and effects on nitrite levels were blocked by an HO-1 inhibitor. These results demonstrate that BG-12 suppresses inflammatory activation in astrocytes and C6 glioma cells, but with distinct mechanisms, different dependence on GSH and different effects on transcription factor activation.

A chicory cytochrome P450 mono-oxygenase CYP71AV8 for the oxidation of (+)-valencene

OpenAIRE

Cankar, K.; Houwelingen, van, A.M.M.L.; Bosch, H.J.; Sonke, Th.; Bouwmeester, H.J.; Beekwilder, M.J.

2011-01-01

Chicory (Cichorium intybus L.), which is known to have a variety of terpene-hydroxylating activities, was screened for a P450 mono-oxygenase to convert (+)-valencene to (+)-nootkatone. A novel P450 cDNA was identified in a chicory root EST library. Co-expression of the enzyme with a valencene synthase in yeast, led to formation of trans-nootkatol, cis-nootkatol and (+)-nootkatone. The novel enzyme was also found to catalyse a three step conversion of germacrene A to germacra-1(10),4,11(13)-tr...

Design and testing of an integrated electronically controlled capacitor for integral and fractional horse power single phase induction motor

International Nuclear Information System (INIS)

Faiz, Jawad; Kasebi, F.; Pillay, P.

2004-01-01

This paper addresses a problem that occurs in many small appliances. As such, it is an important problem of energy utilization. To improve the performance of a single phase capacitor start/run induction motor, FET type power transistors could be used to replace a SCR H bridge. Such a configuration can lead to a simpler and more inexpensive circuit for the electronically controlled capacitor. In this paper, ICs and an OP-AMP are used to design an electronically controlled capacitor for a single phase induction motor. The design can compensate for the input voltage fluctuations that are present in the normal operation of the motor. In addition, an improvement in its performance can be obtained. At present, the use of a tachometer can be considered a disadvantage of the proposed scheme. Thus, a configuration that enables removal of the tachometer, while maintaining reasonable cost, is desirable. In addition, replacing the ac capacitor with one rated for dc can lead to a system reduction, in addition to a considerable reduction in the size of the circuit due to the use of integrated circuits

Effects of Nuclear Factor-E2-related factor 2/Heme Oxygenase 1 on splanchnic hemodynamics in experimental cirrhosis with portal hypertension.

Science.gov (United States)

Qin, Jun; He, Yue; Duan, Ming; Luo, Meng

2017-05-01

We explored the effects of Nuclear Factor-E2-related factor 2 (Nrf2) and Heme Oxygenase 1 (HO-1) on splanchnic hemodynamics in portal hypertensive rats. Experimental cirrhosis with portal hypertension was induced by intraperitoneal injection of carbon tetrachloride. The expression of proteins was examined by immunoblotting. Hemodynamic studies were performed by radioactive microspheres. The vascular perfusion system was used to measure the contractile response of mesentery arterioles in rats. Nrf2 expression in the nucleus and HO-1 expression in cytoplasm was significantly enhanced in portal hypertensive rats. Portal pressure, as well as regional blood flow, increased significantly in portal hypertension and can be blocked by tin protoporphyrin IX. The expression of endogenous nitric oxide synthase and vascular endothelial growth factors increased significantly compared to normal rats, while HO-1 inhibition decreased the expression of these proteins significantly. The contractile response of mesenteric arteries decreased in portal hypertension, but can be partially recovered through tin protoporphyrin IX treatment. The expression of Nrf2/HO-1 increased in mesenteric arteries of portal hypertensive rats, which was related to oxidative stress. HO-1was involved in increased portal pressure and anomaly splanchnic hemodynamics in portal hypertensive rats. Copyright © 2016 Elsevier Inc. All rights reserved.

Non-monotonic behavior of electron temperature in argon inductively coupled plasma and its analysis via novel electron mean energy equation

Science.gov (United States)

Zhao, Shu-Xia

2018-03-01

In this work, the behavior of electron temperature against the power in argon inductively coupled plasma is investigated by a fluid model. The model properly reproduces the non-monotonic variation of temperature with power observed in experiments. By means of a novel electron mean energy equation proposed for the first time in this article, this electron temperature behavior is interpreted. In the overall considered power range, the skin effect of radio frequency electric field results in localized deposited power density, responsible for an increase of electron temperature with power by means of one parameter defined as power density divided by electron density. At low powers, the rate fraction of multistep and Penning ionizations of metastables that consume electron energy two times significantly increases with power, which dominates over the skin effect and consequently leads to the decrease of temperature with power. In the middle power regime, a transition region of temperature is given by the competition between the ionizing effect of metastables and the skin effect of electric field. The power location where the temperature alters its trend moves to the low power end as increasing the pressure due to the lack of metastables. The non-monotonic curve of temperature is asymmetric at the short chamber due to the weak role of skin effect in increasing the temperature and tends symmetric when axially prolonging the chamber. Still, the validity of the fluid model in this prediction is estimated and the role of neutral gas heating is guessed. This finding is helpful for people understanding the different trends of temperature with power in the literature.

Intracellular β-Glucosidases CEL1a and CEL1b Are Essential for Cellulase Induction on Lactose in Trichoderma reesei

Science.gov (United States)

Xu, Jintao; Zhao, Guolei; Kou, Yanbo; Zhang, Weixin; Zhou, Qingxin; Chen, Guanjun

2014-01-01

Lactose (1,4-O-β-d-galacto-pyranosyl-d-glucose) induces cellulolytic enzymes in Trichoderma reesei and is in fact one of the most important soluble carbon sources used to produce cellulases on an industrial level. The mechanism underlying the induction is, however, not fully understood. In this study, we investigated the cellular functions of the intracellular β-glucosidases CEL1a and CEL1b in the induction of cellulase genes by lactose in T. reesei. We demonstrated that while CEL1a and CEL1b were functionally equivalent in mediating the induction, the simultaneous absence of these intracellular β-glucosidases abolished cbh1 gene expression on lactose. d-Galactose restored the efficient cellulase gene induction in the Δcel1a strain independently of its reductive metabolism, but not in the Δcel1a Δcel1b strain. A further comparison of the transcriptional responses of the Δcel1a Δcel1b strain complemented with wild-type CEL1a or a catalytically inactive CEL1a version and the Δcel1a strain constitutively expressing CEL1a or the Kluyveromyces lactis β-galactosidase LAC4 showed that both the CEL1a protein and its glycoside hydrolytic activity were indispensable for cellulase induction by lactose. We also present evidence that intracellular β-glucosidase-mediated lactose induction is further conveyed to XYR1 to ensure the efficiently induced expression of cellulase genes. PMID:24879125

Global model analysis of negative ion generation in low-pressure inductively coupled hydrogen plasmas with bi-Maxwellian electron energy distributions

International Nuclear Information System (INIS)

Huh, Sung-Ryul; Kim, Nam-Kyun; Jung, Bong-Ki; Chung, Kyoung-Jae; Hwang, Yong-Seok; Kim, Gon-Ho

2015-01-01

A global model was developed to investigate the densities of negative ions and the other species in a low-pressure inductively coupled hydrogen plasma with a bi-Maxwellian electron energy distribution. Compared to a Maxwellian plasma, bi-Maxwellian plasmas have higher populations of low-energy electrons and highly vibrationally excited hydrogen molecules that are generated efficiently by high-energy electrons. This leads to a higher reaction rate of the dissociative electron attachment responsible for negative ion production. The model indicated that the bi-Maxwellian electron energy distribution at low pressures is favorable for the creation of negative ions. In addition, the electron temperature, electron density, and negative ion density calculated using the model were compared with the experimental data. In the low-pressure regime, the model results of the bi-Maxwellian electron energy distributions agreed well quantitatively with the experimental measurements, unlike those of the assumed Maxwellian electron energy distributions that had discrepancies

Induction of long noncoding RNA MALAT1 in hypoxic mice

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Lelli A

2015-10-01

Full Text Available Aurelia Lelli,1,2,* Karen A Nolan,1,2,* Sara Santambrogio,1,2 Ana Filipa Gonçalves,1,2 Miriam J Schönenberger,1,2 Anna Guinot,1,2 Ian J Frew,1,2 Hugo H Marti,3 David Hoogewijs,1,2,4 Roland H Wenger1,2 1Institute of Physiology and Zurich Center for Human Physiology (ZIHP, University of Zurich, Zurich, Switzerland; 2National Center of Competence in Research "Kidney.CH", Zurich, Switzerland; 3Institute of Physiology and Pathophysiology, University of Heidelberg, Heidelberg, Germany; 4Institute of Physiology, University of Duisburg-Essen, Essen, Germany *These authors contributed equally to this work Abstract: Long thought to be “junk DNA”, in recent years it has become clear that a substantial fraction of intergenic genomic DNA is actually transcribed, forming long noncoding RNA (lncRNA. Like mRNA, lncRNA can also be spliced, capped, and polyadenylated, affecting a multitude of biological processes. While the molecular mechanisms underlying the function of lncRNAs have just begun to be elucidated, the conditional regulation of lncRNAs remains largely unexplored. In genome-wide studies our group and others recently found hypoxic transcriptional induction of a subset of lncRNAs, whereof nuclear-enriched abundant/autosomal transcript 1 (NEAT1 and metastasis-associated lung adenocarcinoma transcript 1 (MALAT1 appear to be the lncRNAs most ubiquitously and most strongly induced by hypoxia in cultured cells. Hypoxia-inducible factor (HIF-2 rather than HIF-1 seems to be the preferred transcriptional activator of these lncRNAs. For the first time, we also found strong induction primarily of MALAT1 in organs of mice exposed to inspiratory hypoxia. Most abundant hypoxic levels of MALAT1 lncRNA were found in kidney and testis. In situ hybridization revealed that the hypoxic induction in the kidney was confined to proximal rather than distal tubular epithelial cells. Direct oxygen-dependent regulation of MALAT1 lncRNA was confirmed using isolated primary

Transfection of the Human Heme Oxygenase Gene Into Rabbit Coronary Microvessel Endothelial Cells: Protective Effect Against Heme and Hemoglobin Toxicity

Science.gov (United States)

Abraham, N. G.; Lavrovsky, Y.; Schwartzman, M. L.; Stoltz, R. A.; Levere, R. D.; Gerritsen, M. E.

1995-07-01

Heme oxygenase (HO) is a stress protein and has been suggested to participate in defense mechanisms against agents that may induce oxidative injury such as metals, endotoxin, heme/hemoglobin, and various cytokines. Overexpression of HO in cells might therefore protect against oxidative stress produced by certain of these agents, specifically heme and hemoglobin, by catalyzing their degradation to bilirubin, which itself has antioxidant properties. We report here the successful in vitro transfection of rabbit coronary microvessel endothelial cells with a functioning gene encoding the human HO enzyme. A plasmid containing the cytomegalovirus promoter and the human HO cDNA complexed to cationic liposomes (Lipofectin) was used to transfect rabbit endothelial cells. Cells transfected with human HO exhibited an ≈3.0-fold increase in enzyme activity and expressed a severalfold induction of human HO mRNA as compared with endogenous rabbit HO mRNA. Transfected and nontransfected cells expressed factor VIII antigen and exhibited similar acetylated low-density lipoprotein uptake (two important features that characterize endothelial cells) with >85% of cells staining positive for each marker. Moreover, cells transfected with the human HO gene acquired substantial resistance to toxicity produced by exposure to recombinant hemoglobin and heme as compared with nontransfected cells. The protective effect of HO overexpression against heme/hemoglobin toxicity in endothelial cells shown in these studies provides direct evidence that the inductive response of human HO to such injurious stimuli represents an important tissue adaptive mechanism for moderating the severity of cell damage produced by these blood components.

Pyridine induction of cytochrome P450IIE1: Evidence for enhanced protein synthesis

International Nuclear Information System (INIS)

Kim, S.G.; Novak, R.F.

1990-01-01

The dose-, and time-dependent induction of P450IIE1 in the rat by pyridine (PY) has been characterized. A single injection of PY (100 mg/kg, i.p.) increased as the levels of IIE1 2-, 3- and 4-fold at 6, 10 and 24 hr, respectively, relative to controls based on p-nitrophenol hydroxylase activity and Western blot analysis. Induction of IIE1 was dose-dependent over the range 10 to 200 mg/kg. Cycloheximide administration completely prevented the induction of IIE1 by PY, while actinomycin D failed to affect PY induction of IIE1. The rate of IIE1 synthesis was examined by labelling of proteins with [ 14 C] leucine in vivo, followed by SDS-PAGE and autoradiographic analysis of isolated microsomes. Enhanced intensity of the IIE1 band was observed in microsomes isolated from rats treated with either PY or acetone relative to untreated rats. Slot and Northern blot analyses were employed to assess IIE1 mRNA levels in total RNA and poly(A + ) mRNA isolated from livers of rats at 1, 5 and 12 hr following a single dose of PY. No increase in IIE1 mRNA in total RNA was monitored. A time-dependent decrease in IIE1 poly(A + ) mRNA however, was observed with the maximal decrease occurring at ∼12 hr. These results suggest that induction of IIE1 by PY does not involve transcriptional activation but occurs by protein synthesis possibly through increased translational efficiency

Andrographolide inhibits TNFα-induced ICAM-1 expression via suppression of NADPH oxidase activation and induction of HO-1 and GCLM expression through the PI3K/Akt/Nrf2 and PI3K/Akt/AP-1 pathways in human endothelial cells.

Science.gov (United States)

Lu, Chia-Yang; Yang, Ya-Chen; Li, Chien-Chun; Liu, Kai-Li; Lii, Chong-Kuei; Chen, Haw-Wen

2014-09-01

Andrographolide, the major bioactive component of Andrographis paniculata, has been demonstrated to have various biological properties including anti-inflammation, antioxidation, and anti-hepatotoxicity. Oxidative stress is considered a major risk factor in aging, inflammation, cancer, atherosclerosis, and diabetes mellitus. NADPH oxidase is a major source of endogenous reactive oxygen species (ROS). In this study, we used EA.hy926 endothelial-like cells to explore the anti-inflammatory activity of andrographolide. Andrographolide attenuated TNFα-induced ROS generation, Src phosphorylation, membrane translocation of the NADPH oxidase subunits p47(phox) and p67(phox), and ICAM-1 gene expression. In the small hairpin RNA interference assay, shp47(phox) abolished TNFα-induced p65 nuclear translocation, ICAM-1 gene expression, and adhesion of HL-60 cells. Andrographolide induced the gene expression of heme oxygenase 1 (HO-1) and glutamate cysteine ligase modifier subunit (GCLM) in a time-dependent manner. Cellular glutathione (GSH) content was increased by andrographolide. shGCLM attenuated the andrographolide-induced increase in GSH content and reversed the andrographolide inhibition of HL-60 adhesion. shHO-1 showed a similar effect on andrographolide inhibition of HL-60 adhesion to shGCLM. The mechanism underlying the up-regulation of HO-1 and GCLM by andrographolide was dependent on the PI3K/Akt pathway, and both the Nrf2 and AP-1 transcriptional factors were involved. Our results suggest that andrographolide attenuates TNFα-induced ICAM-1 expression at least partially through suppression of NADPH oxidase activation and induction of HO-1 and GCLM expression, which is PI3K/Akt pathway-dependent. Copyright © 2014. Published by Elsevier Inc.

Isorhamnetin inhibits Prevotella intermedia lipopolysaccharide-induced production of interleukin-6 in murine macrophages via anti-inflammatory heme oxygenase-1 induction and inhibition of nuclear factor-κB and signal transducer and activator of transcription 1 activation.

Science.gov (United States)

Jin, J Y; Choi, E Y; Park, H R; Choi, J I; Choi, I S; Kim, S J

2013-12-01

Interleukin-6 (IL-6) is a key proinflammatory cytokine that has been considered to be important in the pathogenesis of periodontal disease. Therefore, host-modulatory agents directed at inhibiting IL-6 appear to be beneficial in terms of attenuating periodontal disease progression and potentially improving disease susceptibility. In the current study, we investigated the effect of the flavonoid isorhamnetin on the production of IL-6 in murine macrophages stimulated with lipopolysaccharide (LPS) from Prevotella intermedia, a pathogen implicated in inflammatory periodontal disease, and its mechanisms of action. Lipopolysaccharide from P. intermedia ATCC 25611 was isolated using the standard hot phenol-water method. Culture supernatants were collected and assayed for IL-6. We used real-time PCR to quantify IL-6 and heme oxygenase-1 (HO-1) mRNA expression. The expression of HO-1 protein and the levels of signaling proteins were monitored using immunoblot analyses. The DNA-binding activity of nuclear factor-κB (NF-κB) was analyzed using ELISA-based assay kits. Isorhamnetin significantly down-regulated P. intermedia LPS-induced production of IL-6 as well as its mRNA expression in RAW264.7 cells. Isorhamnetin up-regulated the expression of HO-1 at both gene transcription and translation levels in cells stimulated with P. intermedia LPS. In addition, inhibition of HO-1 activity by tin protoporphyrin IX blocked the inhibitory effect of isorhamnetin on IL-6 production. Isorhamnetin failed to prevent LPS from activating either c-Jun N-terminal kinase or p38 pathways. Isorhamnetin did not inhibit NF-κB transcriptional activity at the level of inhibitory κB-α degradation. Isorhamnetin suppressed NF-κB signaling through inhibition of nuclear translocation and DNA binding activity of NF-κB p50 subunit and attenuated signal transducer and activator of transcription 1 signaling. Although further research is required to clarify the detailed mechanism of action, we propose

Electroacupuncture Ameliorates Acute Renal Injury in Lipopolysaccharide-Stimulated Rabbits via Induction of HO-1 through the PI3K/Akt/Nrf2 Pathways.

Science.gov (United States)

Yu, Jian-Bo; Shi, Jia; Zhang, Yuan; Gong, Li-Rong; Dong, Shu-An; Cao, Xin-Shun; Wu, Li-Li; Wu, Li-Na

2015-01-01

Electroacupuncture at select acupoints have been verified to protect against organ dysfunctions during endotoxic shock. And, heme oxygenase (HO)-1 as a phase II enzyme and antioxidant contributed to the protection of kidney in septic shock rats. The phosphatidylinositol 3-kinase (PI3K)-Akt pathway mediated the activation of NF-E2 related factor-2 (Nrf2), which was involved in HO-1 induction. To understand the efficacy of electroacupuncture stimulation in ameliorating acute kidney injury (AKI) through the PI3K/Akt/Nrf2 pathway and subsequent HO-1 upregulation, a dose of LPS 5mg/kg was administered intravenously to replicate the rabbit model of AKI induced by endotoxic shock. Electroacupuncture pretreatment was handled bilaterally at Zusanli and Neiguan acupoints for five consecutive days while sham electroacupuncture at non-acupoints as control. Results displayed that electroacupuncture stimulation significantly alleviated the morphologic renal damage, attenuated renal tubular apoptosis, suppressed the elevated biochemical indicators of AKI caused by LPS, enhanced the expressions of phospho-Akt, HO-1protein, Nrf2 total and nucleoprotein, and highlighted the proportions of Nrf2 nucleoprotein as a parallel. Furthermore, partial protective effects of elecroacupuncture were counteracted by preconditioning with wortmannin (the selective PI3K inhibitor), indicating a direct involvement of PI3K/Akt pathway. Inconsistently, wortmannin pretreatment made little difference to the expressions of HO-1, Nrf2 nucleoprotein and total protein, which indicated that PI3K/Akt may be not the only pathway responsible for electroacupuncture-afforded protection against LPS-induced AKI. These findings provide new insights into the potential future clinical applications of electroacupuncture for AKI induced by endotoxic shock instead of traditional remedies.

Proton induction linacs as high-intensity neutron sources

International Nuclear Information System (INIS)

Keefe, D.; Hoyer, E.

1981-01-01

Proton induction linacs are explored as high intensity neutron sources. The induction linac - concept, properties, experience with electrons, and possibilities - and its limitations for accelerating ions are reviewed. A number of proton induction linac designs are examined with the LIACEP program and general conclusions are given. Results suggest that a proton induction accelerator of the lowest voltage, consistent with good neutron flux, is preferred and could well be cost competitive with the usual rf linac/storage ring designs. (orig.)

Analysis of Properties of Induction Machine with Combined Parallel Star-Delta Stator Winding

Czech Academy of Sciences Publication Activity Database

Schreier, Luděk; Bendl, Jiří; Chomát, Miroslav

2017-01-01

Roč. 113, č. 1 (2017), s. 147-153 ISSN 0239-3646 R&D Projects: GA ČR(CZ) GA16-07795S Institutional support: RVO:61388998 Keywords : induction machine * parallel combined stator winding Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering OBOR OECD: Electrical and electronic engineering

Two-phase induction motor drives

DEFF Research Database (Denmark)

Blaabjerg, Frede; Lungeanu, Florin; Skaug, Kenneth

2004-01-01

There is a continuous debate today concerning the ?motor of the future? for low-power applications requiring less than 1-2 kW. The specialists are focusing on superior motors [1] like brushless-dc, permanent-magnet synchronous, or electronically commutated types, because they show improvements...... in efficiency, reliability, torque-per-volume/mass ratio, maintenance, and service life. Despite this effort, the industry seems to be responding with manifest rigidity in changing standard induction motor solutions when considering the installed volume into the field, the investment in manufacturing base...

Isoporphyrin Intermediate in Heme Oxygenase Catalysis

Science.gov (United States)

Evans, John P.; Niemevz, Fernando; Buldain, Graciela; de Montellano, Paul Ortiz

2008-01-01

Human heme oxygenase-1 (hHO-1) catalyzes the O2- and NADPH-dependent oxidation of heme to biliverdin, CO, and free iron. The first step involves regiospecific insertion of an oxygen atom at the α-meso carbon by a ferric hydroperoxide and is predicted to proceed via an isoporphyrin π-cation intermediate. Here we report spectroscopic detection of a transient intermediate during oxidation by hHO-1 of α-meso-phenylheme-IX, α-meso-(p-methylphenyl)-mesoheme-III, and α-meso-(p-trifluoromethylphenyl)-mesoheme-III. In agreement with previous experiments (Wang, J., Niemevz, F., Lad, L., Huang, L., Alvarez, D. E., Buldain, G., Poulos, T. L., and Ortiz de Montellano, P. R. (2004) J. Biol. Chem. 279, 42593–42604), only the α-biliverdin isomer is produced with concomitant formation of the corresponding benzoic acid. The transient intermediate observed in the NADPH-P450 reductase-catalyzed reaction accumulated when the reaction was supported by H2O2 and exhibited the absorption maxima at 435 and 930 nm characteristic of an isoporphyrin. Product analysis by reversed phase high performance liquid chromatography and liquid chromatography electrospray ionization mass spectrometry of the product generated with H2O2 identified it as an isoporphyrin that, on quenching, decayed to benzoylbiliverdin. In the presence of H218O2, one labeled oxygen atom was incorporated into these products. The hHO-1-isoporphyrin complexes were found to have half-lives of 1.7 and 2.4 h for the p-trifluoromethyl- and p-methyl-substituted phenylhemes, respectively. The addition of NADPH-P450 reductase to the H2O2-generated hHO-1-isoporphyrin complex produced α-biliverdin, confirming its role as a reaction intermediate. Identification of an isoporphyrin intermediate in the catalytic sequence of hHO-1, the first such intermediate observed in hemoprotein catalysis, completes our understanding of the critical first step of heme oxidation. PMID:18487208

Modelling of Continual Induction Hardening in Quasi-Coupled Formulation

Czech Academy of Sciences Publication Activity Database

Barglik, J.; Doležel, Ivo; Karban, P.; Ulrych, B.

2005-01-01

Roč. 24, č. 1 (2005), s. 251-260 ISSN 0332-1649 Grant - others:PSRC(PL) 4T08C 04823 Institutional research plan: CEZ:AV0Z20570509 Keywords : mathematical modelling * electromagnetism * induction Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 0.188, year: 2005

REDD1 induction regulates the skeletal muscle gene expression signature following acute aerobic exercise.

Science.gov (United States)

Gordon, Bradley S; Steiner, Jennifer L; Rossetti, Michael L; Qiao, Shuxi; Ellisen, Leif W; Govindarajan, Subramaniam S; Eroshkin, Alexey M; Williamson, David L; Coen, Paul M

2017-12-01

The metabolic stress placed on skeletal muscle by aerobic exercise promotes acute and long-term health benefits in part through changes in gene expression. However, the transducers that mediate altered gene expression signatures have not been completely elucidated. Regulated in development and DNA damage 1 (REDD1) is a stress-induced protein whose expression is transiently increased in skeletal muscle following acute aerobic exercise. However, the role of this induction remains unclear. Because REDD1 altered gene expression in other model systems, we sought to determine whether REDD1 induction following acute exercise altered the gene expression signature in muscle. To do this, wild-type and REDD1-null mice were randomized to remain sedentary or undergo a bout of acute treadmill exercise. Exercised mice recovered for 1, 3, or 6 h before euthanization. Acute exercise induced a transient increase in REDD1 protein expression within the plantaris only at 1 h postexercise, and the induction occurred in both cytosolic and nuclear fractions. At this time point, global changes in gene expression were surveyed using microarray. REDD1 induction was required for the exercise-induced change in expression of 24 genes. Validation by RT-PCR confirmed that the exercise-mediated changes in genes related to exercise capacity, muscle protein metabolism, neuromuscular junction remodeling, and Metformin action were negated in REDD1-null mice. Finally, the exercise-mediated induction of REDD1 was partially dependent upon glucocorticoid receptor activation. In all, these data show that REDD1 induction regulates the exercise-mediated change in a distinct set of genes within skeletal muscle. Copyright © 2017 the American Physiological Society.

Mercury modulates the cytochrome P450 1a1, 1a2 and 1b1 in C57BL/6J mice: in vivo and in vitro studies

International Nuclear Information System (INIS)

Amara, Issa E.A.; Anwar-Mohamed, Anwar; Abdelhamid, Ghada; El-Kadi, Ayman O.S.

2013-01-01

In the current study C57BL/6J mice were injected intraperitoneally with Hg 2+ in the absence and presence of TCDD. After 6 and 24 h the liver was harvested and the expression of Cyps was determined. In vitro, isolated hepatocytes were incubated with TCDD in the presence and absence of Hg 2+ . At the in vivo level, Hg 2+ significantly decreased the TCDD-mediated induction of Cyps at 6 h while potentiating their levels at 24 h. In vitro, Hg 2+ significantly inhibited the TCDD-mediated induction of Cyp1a1 in a concentration- and time-dependent manner. Interestingly, Hg 2+ increased the serum hemoglobin (Hb) levels in mice treated for 24 h. Upon treatment of isolated hepatocytes with Hb alone, there was an increase in the AhR-dependent luciferase activity with a subsequent increase in Cyp1a1 protein and catalytic activity levels. Importantly, when hepatocytes were treated for 2 h with Hg 2+ in the presence of TCDD, then the medium was replaced with new medium containing Hb, there was potentiation of the TCDD-mediated effect. In addition, Hg 2+ increased heme oxygenase-1 (HO-1) mRNA, which coincided with a decrease in the Cyp1a1 activity level. When the competitive HO-1 inhibitor, tin mesoporphyrin was applied to the hepatocytes there was a partial restoration of Hg 2+ -mediated inhibition of Cyp1a1 activity. In conclusion, we demonstrate for the first time that there is a differential modulation of the TCDD-mediated induction of Cyp1a1 by Hg 2+ in C57BL/6J mice livers and isolated hepatocytes. Moreover, this study implicates Hb as an in vivo specific modulator of Cyp1 family. -- Highlights: ► In vivo, Hg 2+ decreased the Cyps at 6 h while potentiating their levels at 24 h. ► In vitro, Hg 2+ significantly inhibited the TCDD-mediated induction of Cyps. ► Hg 2+ increased the serum Hb levels in animals treated for 24 h. ► Hb potentiated the TCDD-mediated effect on Cyps. ► Tin mesoporphyrin partially restored Hg 2+ -mediated inhibition of Cyp1a1.

Heme oxygenase-1 prevents cardiac dysfunction in streptozotocin-diabetic mice by reducing inflammation, oxidative stress, apoptosis and enhancing autophagy.

Directory of Open Access Journals (Sweden)

Yanli Zhao

Full Text Available Heme oxygenase-1 (HO-1 has been implicated in cardiac dysfunction, oxidative stress, inflammation, apoptosis and autophagy associated with heart failure, and atherosclerosis, in addition to its recognized role in metabolic syndrome and diabetes. Numerous studies have presented contradictory findings about the role of HO-1 in diabetic cardiomyopathy (DCM. In this study, we explored the role of HO-1 in myocardial dysfunction, myofibril structure, oxidative stress, inflammation, apoptosis and autophagy using a streptozotocin (STZ-induced diabetes model in mice systemically overexpressing HO-1 (Tg-HO-1 or mutant HO-1 (Tg-mutHO-1. The diabetic mouse model was induced by multiple peritoneal injections of STZ. Two months after injection, left ventricular (LV function was measured by echocardiography. In addition, molecular biomarkers related to oxidative stress, inflammation, apoptosis and autophagy were evaluated using classical molecular biological/biochemical techniques. Mice with DCM exhibited severe LV dysfunction, myofibril structure disarray, aberrant cardiac oxidative stress, inflammation, apoptosis, autophagy and increased levels of HO-1. In addition, we determined that systemic overexpression of HO-1 ameliorated left ventricular dysfunction, myofibril structure disarray, oxidative stress, inflammation, apoptosis and autophagy in DCM mice. Furthermore, serine/threonine-specific protein kinase (Akt and AMP-activated protein kinase (AMPK phosphorylation is normally inhibited in DCM, but overexpression of the HO-1 gene restored the phosphorylation of these kinases to normal levels. In contrast, the functions of HO-1 in DCM were significantly reversed by overexpression of mutant HO-1. This study underlines the unique roles of HO-1, including the inhibition of oxidative stress, inflammation and apoptosis and the enhancement of autophagy, in the pathogenesis of DCM.

Iron depletion in HCT116 cells diminishes the upregulatory effect of phenethyl isothiocyanate on heme oxygenase-1

International Nuclear Information System (INIS)

Bolloskis, Michael P.; Carvalho, Fabiana P.; Loo, George

2016-01-01

Some of the health-promoting properties of cruciferous vegetables are thought to be partly attributed to isothiocyanates. These phytochemicals can upregulate the expression of certain cytoprotective stress genes, but it is unknown if a particular nutrient is involved. Herein, the objective was to ascertain if adequate iron is needed for enabling HCT116 cells to optimally express heme oxygenase-1 (HO-1) when induced by phenethyl isothiocyanate (PEITC). PEITC increased HO-1 expression and also nuclear translocation of Nrf2, which is a transcription factor known to activate the HO-1 gene. However, in HCT116 cells that were made iron-deficient by depleting intracellular iron with deferoxamine (DFO), PEITC was less able to increase HO-1 expression and nuclear translocation of Nrf2. These suppressive effects of DFO were overcome by replenishing the iron-deficient cells with the missing iron. To elucidate these findings, it was found that PEITC-induced HO-1 upregulation can be inhibited with thiol antioxidants (glutathione and N-acetylcysteine). Furthermore, NADPH oxidase inhibitors (diphenyleneiodonium and apocynin) and a superoxide scavenger (Tiron) each inhibited PEITC-induced HO-1 upregulation. In doing so, diphenyleneiodonium was the most potent and also inhibited nuclear translocation of redox-sensitive Nrf2. Collectively, the results imply that the HO-1 upregulation by PEITC involves an iron-dependent, oxidant signaling pathway. Therefore, it is concluded that ample iron is required to enable PEITC to fully upregulate HO-1 expression in HCT116 cells. As such, it is conceivable that iron-deficient individuals may not reap the full health benefits of eating PEITC-containing cruciferous vegetables that via HO-1 may help protect against multiple chronic diseases. - Highlights: • PEITC increased HO-1 expression in HCT116 cells. • PEITC-induced HO-1 upregulation was impaired in iron-depleted HCT116 cells. • Impairment of PEITC-induced HO-1 upregulation was

Induction of the nuclear factor HIF-1α in acetaminophen toxicity: Evidence for oxidative stress

International Nuclear Information System (INIS)

James, Laura P.; Donahower, Brian; Burke, Angela S.; McCullough, Sandra; Hinson, Jack A.

2006-01-01

Hypoxia inducible factor (HIF) controls the transcription of genes involved in angiogenesis, erythropoiesis, glycolysis, and cell survival. HIF-1α levels are a critical determinant of HIF activity. The induction of HIF-1α was examined in the livers of mice treated with a toxic dose of APAP (300 mg/kg IP) and sacrificed at 1, 2, 4, 8, and 12 h. HIF-1α was induced at 1-12 h and induction occurred prior to the onset of toxicity. Pre-treatment of mice with N-acetylcysteine (1200 mg/kg IP) prevented toxicity and HIF-1α induction. In further studies, hepatocyte suspensions were incubated with APAP (1 mM) in the presence of an oxygen atmosphere. HIF-1α was induced at 1 h, prior to the onset of toxicity. Inclusion of cyclosporine A (10 μM), an inhibitor of mitochondrial permeability transition, oxidative stress, and toxicity, prevented the induction of HIF-1α. Thus, HIF-1α is induced before APAP toxicity and can occur under non-hypoxic conditions. The data suggest a role for oxidative stress in the induction of HIF-1α in APAP toxicity

S-nitrosylated proteins of a medicinal CAM plant Kalanchoe pinnata- ribulose-1,5-bisphosphate carboxylase/oxygenase activity targeted for inhibition.

Science.gov (United States)

Abat, Jasmeet K; Mattoo, Autar K; Deswal, Renu

2008-06-01

Nitric oxide (NO) is a signaling molecule that affects a myriad of processes in plants. However, the mechanistic details are limited. NO post-translationally modifies proteins by S-nitrosylation of cysteines. The soluble S-nitrosoproteome of a medicinal, crassulacean acid metabolism (CAM) plant, Kalanchoe pinnata, was purified using the biotin switch technique. Nineteen targets were identified by MALDI-TOF mass spectrometry, including proteins associated with carbon, nitrogen and sulfur metabolism, the cytoskeleton, stress and photosynthesis. Some were similar to those previously identified in Arabidopsis thaliana, but kinesin-like protein, glycolate oxidase, putative UDP glucose 4-epimerase and putative DNA topoisomerase II had not been identified as targets previously for any organism. In vitro and in vivo nitrosylation of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco), one of the targets, was confirmed by immunoblotting. Rubisco plays a central role in photosynthesis, and the effect of S-nitrosylation on its enzymatic activity was determined using NaH14CO3. The NO-releasing compound S-nitrosoglutathione inhibited its activity in a dose-dependent manner suggesting Rubisco inactivation by nitrosylation for the first time.

Isolation and characterization of cbbL and cbbS genes encoding form I ribulose-1,5-bisphosphate carboxylase/oxygenase large and small subunits in Nitrosomonas sp. strain ENI-11.

Science.gov (United States)

Hirota, Ryuichi; Kato, Junichi; Morita, Hiromu; Kuroda, Akio; Ikeda, Tsukasa; Takiguchi, Noboru; Ohtake, Hisao

2002-03-01

The cbbL and cbbS genes encoding form I ribulose-1,5-bisphosphate carboxylase/oxygenase (RubisCO) large and small subunits in the ammonia-oxidizing bacterium Nitrosomonas sp. strain ENI-11 were cloned and sequenced. The deduced gene products, CbbL and CbbS, had 93 and 87% identity with Thiobacillus intermedius CbbL and Nitrobacter winogradskyi CbbS, respectively. Expression of cbbL and cbbS in Escherichia coli led to the detection of RubisCO activity in the presence of 0.1 mM isopropyl-beta-D-thiogalactopyranoside (IPTG). To our knowledge, this is the first paper to report the genes involved in the carbon fixation reaction in chemolithotrophic ammonia-oxidizing bacteria.

Impact of Bariatric Surgery on Heme Oxygenase-1, Inflammation, and Insulin Resistance in Morbid Obesity with Obstructive Sleep Apnea.

Science.gov (United States)

Tirado, Raquel; Masdeu, Maria José; Vigil, Laura; Rigla, Mercedes; Luna, Alexis; Rebasa, Pere; Pareja, Rocío; Hurtado, Marta; Caixàs, Assumpta

2017-09-01

Morbid obesity and obstructive sleep apnea (OSA) interact at an inflammatory level. Bariatric surgery reduces inflammatory responses associated with obesity. Heme oxygenase-1 (HO-1) is an enzyme with anti-inflammatory properties, which might be increased in morbid obesity or OSA. We studied morbidly obese patients with OSA to determine: (a) HO-1 plasma concentrations according to OSA severity and their relationship with insulin resistance and inflammation and (b) the impact of bariatric surgery on HO-1 and parameters of insulin resistance and inflammation. We analyzed the homeostasis model insulin resistance index (HOMA) and plasma concentrations of HO-1, tumor necrosis factor alpha, interleukin-6, interleukin-1-beta, C reactive protein (CRP), and adiponectin according to polysomnography findings in 66 morbidly obese patients before bariatric surgery and 12 months after surgery. Before surgery, HO-1 plasma concentrations were similar in three groups of patients with mild, moderate, and severe OSA, and correlated with HOMA (r = 0.27, p = 0.02). Twelve months after surgery, low-grade inflammation and insulin resistance had decreased in all the groups, but HO-1 plasma concentration had decreased only in the severe OSA group (p = 0.02). In this group, the reduction in HO-1 correlated with a reduction in CRP concentrations (r = 0.43, p = 0.04) and with improved HOMA score (r = 0.37, p = 0.03). Bariatric surgery decreases HO-1 concentrations in morbid obesity with severe OSA, and this decrease is associated with decreases in insulin resistance and in inflammation.

High current induction linacs

International Nuclear Information System (INIS)

Barletta, W.; Faltens, A.; Henestroza, E.; Lee, E.

1994-07-01

Induction linacs are among the most powerful accelerators in existence. They have accelerated electron bunches of several kiloamperes, and are being investigated as drivers for heavy ion driven inertial confinement fusion (HIF), which requires peak beam currents of kiloamperes and average beam powers of some tens of megawatts. The requirement for waste transmutation with an 800 MeV proton or deuteron beam with an average current of 50 mA and an average power of 40 MW lies midway between the electron machines and the heavy ion machines in overall difficulty. Much of the technology and understanding of beam physics carries over from the previous machines to the new requirements. The induction linac allows use of a very large beam aperture, which may turn out to be crucial to reducing beam loss and machine activation from the beam halo. The major issues addressed here are transport of high intensity beams, availability of sources, efficiency of acceleration, and the state of the needed technology for the waste treatment application. Because of the transformer-like action of an induction core and the accompanying magnetizing current, induction linacs make the most economic sense and have the highest efficiencies with large beam currents. Based on present understanding of beam transport limits, induction core magnetizing current requirements, and pulse modulators, the efficiencies could be very high. The study of beam transport at high intensities has been the major activity of the HIF community. Beam transport and sources are limiting at low energies but are not significant constraints at the higher energies. As will be shown, the proton beams will be space-charge-dominated, for which the emittance has only a minor effect on the overall beam diameter but does determine the density falloff at the beam edge

The effects of 5-fluorouracil and doxorubicin on expression of human immunodeficiency virus type 1 long terminal repeat

International Nuclear Information System (INIS)

Panozzo, J.; Akan, E.; Griffiths, T.D.

1996-01-01

Previous work by many groups has documented induction of the HIV-LTR following exposure of cells to ultraviolet light and other DNA damaging agents. Our experiments set out to determine the relative activation or repression of the HIV-LTR in response to two classes of chemotherapeutic agents: Doxorubicin is a DNA-damage inducing agent, and 5-fluorouracil has an antimetabolic mode of action. Using HeLa cells stably transfected with a construct in which HIV-LTR drives expression of the chloramphenicol acetyl transferase reporter gene, we demonstrated an up to 10-fold induction following doxorubicin treatment in 24 h post-treatment. This induction was repressed by treatment with salicylic acid, suggesting a role for prostaglandin/cyclo-oxygenase pathways and/or NFKB in the inductive response. Induction by 5-fluorouracil, in contrast, was more modest (two-fold at most) though it was consistently elevated over controls

Undulative induction electron accelerator for the waste and natural water purification systems

CERN Document Server

Kulish, Victor V; Gubanov, I V

2001-01-01

The project analysis of Undulative Induction Accelerator (EH - accelerator) for the waste and natural water purification systems is accomplished. It is shown that the use of the four-channel design of induction block and the standard set of auxiliary equipment (developed earlier for the Linear Induction Accelerators - LINACs) allow to construct commercially promising purification systems. A quality analysis of the accelerator is done and the optimal parameters are chosen taking into account the specific sphere of its usage.

Induction linac driven relativistic klystron and cyclotron autoresonance maser experiments

International Nuclear Information System (INIS)

Goodman, D.L.; Birx, D.L.; Danly, B.G.

1991-01-01

In this paper design and experimental results are presented from two high power microwave generation experiments utilizing a high repetition rate induction linac generated electron beam. A relativistic klystron has generated more than 100 MW microwave pulses in X-band for 50 ns without pulse shortening or breakdown. design studies for the first cyclotron autoresonance maser (CARM) amplifier using an induction linac electron beam are also presented

Psidium guajava extract inhibits thymus and activation-regulated chemokine (TARC/CCL17) production in human keratinocytes by inducing heme oxygenase-1 and blocking NF-κB and STAT1 activation.

Science.gov (United States)

Han, Eun Hee; Hwang, Yong Pil; Choi, Jae Ho; Yang, Ji Hye; Seo, Jong Kwon; Chung, Young Chul; Jeong, Hye Gwang

2011-09-01

Psidium guajava (P. guajava) is a food and medicinal plant with antioxidant, anti-inflammatory, and anti-allergic activities that support its traditional uses. The aim of this study was to determine the effects of P. guajava ethyl acetate extract (PGEA) on atopic dermatitis and to investigate the possible mechanisms by which PGEA inhibits cytokine-induced Th2 chemokine expression in HaCaT human keratinocyte cells. We found that PGEA suppressed the IFN-γ/TNF-α-co-induced production of thymus and activation-regulated chemokine (TARC) protein and mRNA in HaCaT cells. Additionally, PGEA inhibited the TNF-α/IFN-γ-co-induced activation of NF-κB and STAT1 and increased the expression of heme oxygenase-1 (HO-1) protein and mRNA. HO-1 inhibitor enhanced the suppressive effects of PGEA on TNF-α/IFN-γ-co-induced TARC production and gene expression. Collectively, these data demonstrate that PGEA inhibits chemokine expression in keratinocytes by inducing HO-1 expression and it suggests a possible therapeutic application in atopic dermatitis and other inflammatory skin diseases. Copyright © 2011 Elsevier B.V. All rights reserved.

Postneonatal Mortality and Liver Changes in Cloned Pigs Associated with Human Tumor Necrosis Factor Receptor I-Fc and Human Heme Oxygenase-1 Overexpression