• Title/Summary/Keyword: Heme oxygenase

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Effects of Lipopolysaccharide-Induced Heme Oxygenase and Carbon Monoxide Production on the Aortic Contractility (Lipopolysaccharide에 의한 Heme Oxygenase Induction과 Carbon Monoxide생성이 혈관수축력에 미치는 영향)

  • 장우성;손의동;이석용
    • YAKHAK HOEJI
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    • v.45 no.1
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    • pp.78-84
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    • 2001
  • Heme oxygenase is a rate-limiting enzyme in heme catabolism that cleaves heme to form biliverdin, iron, and carbon monoxide. Heme oxygenase-1 is expressed in many types of cells and tissues and is highly induced in response to oxidative stress. Carbon monoxide, one of the products of heme oxygenase, can stimulate soluble guanylate cyclase and dilate the vascular smooth muscle. So, the induction of heme oxygenase by lipopolysaccharide (LPS)-induced oxydative stress and the effect of the resultant carbon monoxide on aortic contractility were examined in this study. Zinc protoporphyrine IX (ZnPP), a inhibitor of heme oxygenase, elicited weak contraction of thoracic aortic ring, and this effect was more potent in aorta of LPS-treated rats than control and was blocked by methylene blue. The hyperreactivity to ZnPP in LPS-treated group was blocked by co-treatment with aminoguanidine. In the aortic ring of LPS-treated rats, ZnPP didn't change the vasoreactivity to phenylephrine or acetylcholine. ZnPP elicited hyper-tensive effect in concious rats, and pretreatment with LPS did not affect this effect. Prazosin significantly diminished the hypertensive effect of ZnPP. These results indicate that LPS induced heme oxygenase in aotra, and the resultant carbon monoxide diminished the aortic reactivity to vasoconstrictor.

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Bacillus subtilis HmoB is a heme oxygenase with a novel structure

  • Park, Seong-Hun;Choi, Sa-Rah;Choe, Jung-Woo
    • BMB Reports
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    • v.45 no.4
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    • pp.239-241
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    • 2012
  • Iron availability is limited in the environment and most bacteria have developed a system to acquire iron from host hemoproteins. Heme oxygenase plays an important role by degrading heme group and releasing the essential nutrient iron. The structure of Bacillus subtilis HmoB was determined to 2.0 ${\AA}$ resolution. B. subtilis HmoB contains a typical antibiotic biosynthesis monooxygenase (ABM) domain that spans from 71 to 146 residues and belongs to the IsdG family heme oxygenases. Comparison of HmoB and IsdG family proteins showed that the C-terminal region of HmoB has similar sequence and structure to IsdG family proteins and contains conserved critical residues for heme degradation. However, HmoB is distinct from other IsdG family proteins in that HmoB is about 60 amino acids longer in the N-terminus and does not form a dimer whereas previously studied IsdG family heme oxygenases form functional homodimers. Interestingly, the structure of monomeric HmoB resembles the dimeric structure of IsdG family proteins. Hence, B. subtilis HmoB is a heme oxygenase with a novel structural feature.

Heme Oxygenase-1 : Its Therapeutic Roles in Inflammatory Diseases

  • Pae, Hyun-Ock;Chung, Hun-Taeg
    • IMMUNE NETWORK
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    • v.9 no.1
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    • pp.12-19
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    • 2009
  • Heme oxygenase (HO)-1 is an inducible enzyme that catalyzes the first and rate-limiting step in the oxidative degradation of free heme into ferrous iron, carbon monoxide (CO), and biliverdin (BV), the latter being subsequently converted into bilirubin (BR). HO-1, once expressed during inflammation, forms high concentrations of its enzymatic by-products that can influence various biological events, and this expression is proven to be associated with the resolution of inflammation. The degradation of heme by HO-1 itself, the signaling actions of CO, the antioxidant properties of BV/BR, and the sequestration of ferrous iron by ferritin all concertedly contribute to the anti-inflammatory effects of HO-1. This review focuses on the anti-inflammatory mechanisms of HO-1 actions and its roles in inflammatory diseases.

Possible Role of Heme Oxygenase-1 and Prostaglandins in the Pathogenesis of Cerebral Malaria: Heme Oxygenase-1 Induction by Prostaglandin $D_2$ and Metabolite by a Human Astrocyte Cell Line

  • Kuesap, Jiraporn;Na-Bangchang, Kesara
    • Parasites, Hosts and Diseases
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    • v.48 no.1
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    • pp.15-21
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    • 2010
  • Astrocytes are the most abundant cells in the central nervous system that play roles in maintaining the blood-brain-barrier and in neural injury, including cerebral malaria, a severe complication of Plasmodium falciparum infection. Prostaglandin (PG) $D_2$ is abundantly produced in the brain and regulates the sleep response. Moreover, $PGD_2$ is a potential factor derived from P. falciparum within erythrocytes. Heme oxygenase-1 (HO-1) is catalyzing enzyme in heme breakdown process to release iron, carbon monoxide, and biliverdin/bilirubin, and may influence iron supply to the P. falciparum parasites. Here, we showed that treatment of a human astrocyte cell line, CCF-STTG1, with $PGD_2$ significantly increased the expression levels of HO-1 mRNA by RT-PCR. Western blot analysis showed that $PGD_2$ treatment increased the level of HO-1 protein, in a dose- and time-dependent manner. Thus, $PGD_2$ may be involved in the pathogenesis of cerebral malaria by inducing HO-1 expression in malaria patients.

Effect of Heme Oxygenase Induction by NO Donor on the Aortic Contractility

  • Kim, Chang-Kyun;Sohn, Uy-Dong;Lee, Seok-Yong
    • The Korean Journal of Physiology and Pharmacology
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    • v.5 no.1
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    • pp.87-92
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    • 2001
  • Carbon monoxide (CO) binds to soluble guanylate cyclase to lead its activation and elicits smooth muscle relaxation. The vascular tissues have a high capacity to produce CO, since heme oxygenase-2 (HO-2) is constitutively expressed in endothelial and smooth muscle cells, and HO-1 can be greatly up-regulated by oxidative stress. Moreover, the substrate of HO, heme, is readily available for catalysis in vascular tissue. Although the activation of heme oxygenase pathway under various stress conditions may provide a defence mechanism in compromised tissues, the specific role of HO-1-derived CO in the control of aortic contractility still remains to be elucidated. The present study was done to determine the effect of HO-1 induction on the aortic contractility. Thus, the effects of incubation of aortic tissue with S-nitroso-N-acetylpenicillamine (SNAP) for 1 hr on the aortic contractile response to phenylephrine were studied. The preincubation with SNAP resulted in depression of the vasoconstrictor response to phenylephrine. This effect was restored by HO inhibitor or methylene blue but not by NOS inhibitor. The attenuation of vascular reactivity by preincubation with SNAP was also revealed in endothelium-free rings. $AlF4^--evoked$ contraction in control did not differ from that in SNP-treated group. These results suggest that increased production of CO was responsible for the reduction of the contractile response to phenylephrine in aortic ring preincubated with SNAP and this effect of SNAP was independent on endothelium.

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Heme Oxygenase Inducers from Natural Products

  • Chung, Hun-Taeg;Pae, Hyun-Ock;Park, Byung-Min;Oh, Gi-Su
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 2004.04a
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    • pp.21-35
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    • 2004
  • Heme oxygenase (HO)-l catabolizes heme into three products: carbon monoxide, bilirubin, and free iron. HO-l serves as a protective gene by virtue of the anti-inflammatory, anti-apoptotic and anti-proliferative actions of one or more of these three products. HO-l can be regarded as a potential therapeutic target in a variety of oxidant-mediated and inflammatory diseases. In this respect, it would be valuable to develop potent and selective inducers of HO-1 for therapeutic use. Here, we have shown that 1,2,3,4,6-penta-O-galloyl-beta-D-glucose, catalposide and dehydrocostus lactone are potent inducers of HO-1 and exert cytoprotective and anti-inflammatory activities via HO-1-ependent machanism.

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Heme Oxygenase-1 (HO-1) Induction by UVB (290-320nm) Radiation in ICR Mice (ICR mouse의 피부와 간에서 자외선 B파에 의한 Heme Oxygenase-1의 유도)

  • Choi, Wook-Hee;Kim, Tae-Hwan;Ahn, Ryoung-Me
    • Journal of Environmental Health Sciences
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    • v.34 no.1
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    • pp.49-54
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    • 2008
  • The induction of heme oxygenase-1(HO-1) by UV radiation provides a protective defence against oxidative stress, and has been well demonstrated in skin irradiated with UVA, but not UVB. In this study, we show that the induction of cutaneous HO-l can be attributed to UVB radiation. The expression of HO-1 mRNA was assessed in vivo by reverse transcription-polymerase chain reaction (RT-PCR) analysis, and HO-1 enzyme activity was measured in microsomal preparation from irradiated mice. The mRNA level of HO-1 increases in liver and skin from 1d to 3d after UVB $(3KJ/m^2)$ exposure. The results of gene expression were same pattern of HO-1 enzyme activity in skin, but not in liver. HO-1 mRNA in liver resulted in a progressive increase to 4d after UVB exposure, but HO-1 activity in liver increased to 2d. This finding indicates that UVB radiation is an important inducer of HO-1 and increases in HO activity may protect tissue directly or indirectly from oxidative stress.

Effects of substance P on mineralization markers and heme oxygenase-1 Expression in human immortalized periodontal ligament cells

  • Cho, You-Min;Suh, Chung-Hwan;Chun, Sang-Woo;Kim, Eun-Cheol;Kang, Kyung-Hwa
    • International Journal of Oral Biology
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    • v.33 no.4
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    • pp.131-135
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    • 2008
  • Substance P (SP) is known to be expressed in the nerve fibers of dental pulp and periodontal tissues. It was recently reported that SP expression increased in response to orthodontic force. In the present study, we investigated the effect of SP on expression of mineralization markers and heme oxygenase-1 (HO-1) in human immortalized periodontal ligament (IPDL) cells. Cell viability was measured using a 3,4,5-dimethylthiazol-2-yl-2,5-diphenyl tetrazolium bromide (MTT) assay. The expression of mineralization markers, including alkaline phosphatase (ALP), osteonectin (ON) and bone sialoprotein (BSP), and heme oxygenase-1 (HO-1) was assessed by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analysis. SP did not significantly change human IPDL cell viability, with the exception of the 24 hour treatment group. Treatment of human IPDL cells with $10^{-10}$ to $10^{-4}M$ SP upregulated mineralization marker and HO-1 expression in a time- and concentration-dependent manner. Our results suggest that SP may modulate osteoblastic cell differentiation of human IPDL cells through a mechanism involving HO-1 expression.

Chemoprevention and Chemoprotection Through Heme Oxygenase-1 Induction and Underlying Molecular Mechanisms (Heme oxygenase-1 유도를 통한 화학 암예방 및 세포보호와 그 분자생물학적 기전)

  • Kim, Eun-Hee;Kim, Sung-Hwan;Na, Hye-Kyung;Surh, Young-Joon
    • Environmental Mutagens and Carcinogens
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    • v.26 no.4
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    • pp.97-112
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    • 2006
  • Heme oxygenase(HO)-1 is an important antioxidant enzyme that plays a pivotal role in cellular adaptation and protection in response to a wide array of noxious stimuli. Thus, HO-1 induction has been associated with prevention or mitigation of pathogenesis of various diseases, including acute inflammation, atherosclerosis, degenerative diseases, and carcinogenesis. Recent progress in our understanding of the function of molecules in the cellular signaling network as key modulators of gene transcription sheds light on the molecular mechanisms underlyuing HO-1 gene expression. A panel of redox-sensitive transcription factors such as activator protein-1, nuclear factor-kB, and nuclear factor E2-related factor-2, and some of the upstream kinases have been identified as prime regulators of HO-1 gene induction. This review summarizes molecular mechanisms underlying HO-1 expression and the significance of targeted induction of HO-1 as a potential chemopreventive or chemoprotective strategy.

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