• BMB Reports
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• 제50권2호
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• pp.103-108
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• 2017

Heme oxygenase (HO-1) catalyzes heme to carbon monoxide (CO), biliverdin/bilirubin, and iron and is known to prevent the pathogenesis of several human diseases. We assessed the beneficial effect of heme degradation products on osteoclastogenesis induced by receptor activator of NF-${\kappa}B$ ligand (RANKL). Treatment of RAW264.7 cells with CORM-2 (a CO donor) and bilirubin, but not with iron, decreased RANKL-induced osteoclastogenesis, with CORM-2 having a more potent anti-osteogenic effect. CORM-2 also inhibited RANKL-induced osteoclastogenesis and osteoclastic resorption activity in marrow-derived macrophages. Treatment with hemin, a HO-1 inducer, strongly inhibited RANKL-induced osteoclastogenesis in wild-type macrophages, but was ineffective in $HO-1^{+/-}$ cells. CORM-2 reduced RANKL-induced NFATc1 expression by inhibiting IKK-dependent NF-${\kappa}B$ activation and reactive oxygen species production. These results suggest that CO potently inhibits RANKL-induced osteoclastogenesis by inhibiting redox-sensitive NF-${\kappa}B$-mediated NFATc1 expression. Our findings indicate that HO-1/CO can act as an anti-resorption agent and reduce bone loss by blocking osteoclast differentiation.

• Biomolecules & Therapeutics
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• 제22권5호
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• pp.390-399
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• 2014

Chalcones (1,3-diaryl-2-propen-1-ones), a flavonoid subfamily, are widely known for their anti-inflammatory properties. Propenone moiety in chalcones is known to play an important role in generating biological responses by chalcones. In the present study, we synthesized chalcone derivatives structurally modified in propenone moiety and examined inhibitory effect on nitric oxide (NO) production and its potential mechanisms. Among the chalcone derivatives used for this study, TI-I-174 (3-(2-Hydroxyphenyl)-1-(thiophen-3-yl)prop-2-en-1-one) most potently inhibited lipopolysaccharide (LPS)-stimulated nitrite production in RAW 264.7 macrophages. TI-I-174 treatment also markedly inhibited inducible nitric oxide synthase (iNOS) expression. However, TI-I-174 did not significantly affect production of IL-6, cyclooxygenase-2 (COX-2) and tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$), implying that TI-I-174 inhibits production of inflammatory mediators in a selective manner. Treatment of macrophages with TI-I-174 significantly inhibited transcriptional activity of activator protein-1 (AP-1) as determined by luciferase reporter gene assay, whereas nuclear factor-${\kappa}B$ (NF-${\kappa}B$) activity was not affected by TI-I-1744. In addition, TI-I-174 significantly inhibited activation of c-Jun-N-Terminal kinase (JNK) without affecting ERK1/2 and p38MAPK, indicating that down-regulation of iNOS gene expression by TI-I-174 is mainly attributed by blockade of JNK/AP-1 activation. We also demonstrated that TI-I-174 treatment led to an increase in heme oxygenase-1 (HO-1) expression both at mRNA and protein level. Transfection of siRNA targeting HO-1 reversed TI-I-174-mediated inhibition of nitrite production. Taken together, these results indicate that TI-I-174 suppresses NO production in LPS-stimulated RAW 264.7 macrophages via induction of HO-1 and blockade of AP-1 activation.

• 대한의생명과학회지
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• 제20권2호
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• pp.56-61
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• 2014

This study attempted to confirm the antioxidative potential of luteolin against tert-butyl hydroperoxide (t-BHP) induced oxidative damage and to investigate its molecular mechanism related to glutathione (GSH)-dependent enzymes in HepG2 cells. Treatment with luteolin resulted in attenuation of t-BHP induced generation of reactive oxygen species (ROS) and oxidative stress-mediated cell death. In addition, accelerated expression of GSH-dependent antioxidative enzymes, glutathione peroxidase (GPx) and glutathione reductase (GR), and heme oxygenase (HO)-1, as well as strengthened GSH content was induced by treatment with luteolin, which was in accordance with increased nuclear translocation of nuclear factor-erythroid 2 p45-related factor 2 (Nrf2), a transcription factor for phase 2 enzymes, in a dose-dependent manner. These results suggest that the cytoprotective potential of luteolin against oxidative damage can be attributed to fortified GSH-mediated antioxidative pathway and HO-1 expression through regulation of Nrf2 in HepG2 cells.

• IMMUNE NETWORK
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• 제20권3호
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• pp.26.1-26.9
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• 2020

Cereblon (CRBN), a negative modulator of AMP-activated protein kinase (AMPK), is highly expressed in the retina. We confirmed the expression of CRBN in ARPE-19 human retinal cells by Western blotting. We also demonstrated that CRBN knock-down (KD) could effectively downregulate IL-6 and MCP-1 protein and gene expression in LPS-stimulated ARPE-19 cells. Additionally, CRBN KD increased the phosphorylation of AMPK/acetylcoenzyme A carboxylase (ACC) and the expression of heme oxygenase-1 (HO-1) in ARPE-19 cells. Furthermore, CRBN KD significantly reduced LPS-induced nuclear translocation of NF-κB p65 and activation of NF-κB promoter activity. However, these processes could be inactivated by compound C (inhibitor of AMPK) and zinc protoporphyrin-1 (ZnPP-1; inhibitor of HO-1). In conclusion, compound C and ZnPP-1 can rescue LPS-induced levels of proinflammatory cytokines (IL-6 and MCP-1) in CRBN KD ARPE-19 cells. Our data demonstrate that CRBN deficiency negatively regulates proinflammatory cytokines via the activation of AMPK/HO-1 in the retina.

• 대한한의학방제학회지
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• 제16권2호
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• pp.193-204
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• 2008

Dehydrocostus lactone (DHL) and Mokko lactone (ML) were isolated from Saussureae Radix, and their effects on heme oxygenase-1 (HO-1) expression and hepatoprotection in the liver cell line HepG2 were investigated. DHL induced HO-1 expression and HO activity in a dose-dependent manner, whereas ML lacking one double bond property at 11 and 13 carbons on its own chemical structure had no apparent effects. DHL also induced Nrf2 nuclear translocation and enhanced antioxidant response element (ARE) activation which mediated HO-1 gene transcription. Pretreatment with DHL protected HepG2 cells against oxidative damages caused by H2O2. Interestingly, the hepatoprotective effects of DHL appeared to be associated with HO enzymatic activation, HO-1 expression and Nrf2 activation, because blockage of HO activity by a HO inhibitor and inhibition of HO-1 and Nrf2 cellular synthesis by small interfering RNA abolished heptoprotection afforded by DHL. Taken together, this investigation provides evidence supporting that Saussureae Radix is hepatoprotective against oxidative stress that causes abnormal liver damages.

• Tuberculosis and Respiratory Diseases
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• 제60권3호
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• pp.314-320
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• 2006

연구배경: 항암화학요법은 수술이 불가능한 진행성 비소세포폐암환자에서 주요한 치료 방법이지만 전신 부작용 때문에 모든 환자들에게 권할 수 있는 치료법이 되지 못한다. 만약 항암화학요법에 대한 반응 정도를 예측할 수 있다면 치료계획 수립에 도움이 될 수 있을 것이다. Heme oxygenase(HO)는 헴을 산화 분해하는 효소로 세포를 보호하고 세포자멸사를 억제하는 작용이 있음이 알려져 있다. 이에 저자들은 조직 내 HO-1의 발현이 증가되어 있는 경우는 cisplatin을 포함하는 항암화학요법에 저항성을 보일 것으로 가정하였고, 비소세포폐암조직에서 면역조직화학 염색을 이용하여 HO-1의 발현여부를 평가하고 항암화학요법에 대한 치료반응과의 연관성을 알아보고자 하였다. 방 법: 1997년 7월에서 2004년 7월까지 동아대학병원에 내원하여 진행성 비소세포폐암으로 진단받은 환자 중 cisplatin을 포함한 항암화학요법을 2회 이상 시행 받고 치료에 대한 반응을 평가할 수 있는 59명의 환자를 대상으로 후향적 연구를 시행하였다. 대상 환자들을 cisplatin을 포함하는 항암화학요법에 대한 치료 반응 정도 및 다른 임상 특성에 따라 분류하여 조직 내 HO-1의 발현 정도와의 연관성을 알아보았다. 결 과: 총 59명의 폐암조직에서 HO-1의 발현을 조사한 결과 43명(72.8%)에서 양성을 보였다. 조직형, 병기, 종양의 크기와 HO-1 발현은 통계적으로 유의한 연관성이 없었으며, HO-1의 치료 전 발현도 cisplatin을 포함하는 항암화학요법에 대한 치료효과와의 연관성도 없었다. 결 론: 결론적으로 본 연구에서는 진행성비소세포폐암환자의 치료 전 폐암조직에서 HO-1의 발현여부가 cisplatin을 근간으로 하는 항암화학치료의 반응을 예측하는 인자로서의 통계학적 의미는 찾을 수 없었으며 이를 검정하기위한 전향적 연구가 필요하리라 생각된다.

• BMB Reports
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• 제50권4호
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• pp.220-225
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• 2017

Antisense transcripts were initially identified as transcriptional noise, but have since been reported to play an important role in the quality control of miRNA functions. In this report, we tested the hypothesis that heterogeneous nuclear ribonucleoprotein K (hnRNPK) regulates miRNA function via competitive endogenous RNAs, such as pseudogenes, long non-coding RNAs, and antisense transcripts. Based on analyses of RNA sequencing data, the knockdown of hnRNPK decreased the antisense PTOV1-AS1 transcript which harbors five binding sites for miR-1207-5p. We identified heme oxygenase-1 (HO-1) mRNA as a novel target of miR-1207-5p by western blotting and Ago2 immunoprecipitation. The knockdown of hnRNPK or PTOV1-AS1 suppressed HO-1 expression by increasing the enrichment of HO-1 mRNA in miR-1207-5p-mediated miRISC. Downregulation of HO-1 by a miR-1207-5p mimic or knockdown of hnRNPK and PTOV1-AS1 inhibited the proliferation and clonogenic ability of HeLa cells. Taken together, our results demonstrate that hnRNPK-regulated PTOV1-AS1 modulates HO-1 expression via miR-1207-5p.

• Biomolecules & Therapeutics
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• 제31권6호
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• pp.674-681
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• 2023

Bile pigment, bilirubin, and biliverdin concentrations may change as a results of biliary tract cancer (BTC) altering the mechanisms of radical oxidation and heme breakdown. We explored whether changes in bile pigment components could help distinguish BTC from benign biliary illness by evaluating alterations in patients with BTC. We collected bile fluid from 15 patients with a common bile duct stone (CBD group) and 63 individuals with BTC (BTC group). We examined the bile fluid's bilirubin, biliverdin reductase (BVR), heme oxygenase (HO-1), and bacterial taxonomic abundance. Serum bilirubin levels had no impact on the amounts of bile HO-1, BVR, or bilirubin. In comparison to the control group, the BTC group had considerably higher amounts of HO-1, BVR, and bilirubin in the bile. The areas under the curve for the receiver operating characteristic curve analyses of the BVR and HO-1 were 0.832 (p<0.001) and 0.891 (p<0.001), respectively. Firmicutes was the most prevalent phylum in both CBD and BTC, according to a taxonomic abundance analysis, however the Firmicutes/Bacteroidetes ratio was substantially greater in the BTC group than in the CBD group. The findings of this study showed that, regardless of the existence of obstructive jaundice, biliary carcinogenesis impacts heme degradation and bile pigmentation, and that the bile pigment components HO-1, BVR, and bilirubin in bile fluid have a diagnostic significance in BTC. In tissue biopsies for the diagnosis of BTC, particularly for distinguishing BTC from benign biliary strictures, bile pigment components can be used as additional biomarkers.

• Nutrition Research and Practice
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• 제8권4호
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• pp.352-359
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• 2014

BACKGROUND/OBJECTIVES: In this study, we determined the anti-inflammatory activities and the underlying molecular mechanisms of the methanol extract from Erigeron Canadensis L. (ECM) in LPS-stimulated RAW264.7 macrophage cells. MATERIALS/METHODS: The potential anti-inflammatory properties of ECM were investigated by using RAW264.7 macrophages. We used western blot assays and real time quantitative polymerase chain reaction to detect protein and mRNA expression, respectively. Luciferase assays were performed to determine the transactivity of transcription factors. RESULTS: ECM significantly inhibited inducible nitric oxide synthase (iNOS)-derived NO and cyclooxygenase-2 (COX-2) derived PGE2 production in LPS-stimulated RAW264.7 macrophages. These inhibitory effects of ECM were accompanied by decreases in LPS-induced nuclear translocations and transactivities of $NF{\kappa}B$. Moreover, phosphorylation of mitogen-activated protein kinase (MAPKs) including extracellular signal-related kinase (ERK1/2), p38, and c-jun N-terminal kinase (JNK) was significantly suppressed by ECM in LPS-stimulated RAW264.7 macrophages. Further studies demonstrated that ECM by itself induced heme oxygenase-1 (HO-1) protein expression at the protein levels in dose-dependent manner. However, zinc protoporphyrin (ZnPP), a selective HO-1 inhibitor, abolished the ECM-induced suppression of NO production. CONCLUSIONS: These results suggested that ECM-induced HO-1 expression was partly responsible for the resulting anti-inflammatory effects. These findings suggest that ECM exerts anti-inflammatory actions and help to elucidate the mechanisms underlying the potential therapeutic values of Erigeron Canadensis L.

• Anatomy and Cell Biology
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• 제50권3호
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• pp.207-213
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• 2017

Glycogen synthase kinase $(GSK)-3{\beta}$ and related enzymes are associated with various forms of neuroinflammation, including spinal cord injury (SCI). Our aim was to evaluate whether lithium, a non-selective inhibitor of $GSK-3{\beta}$, ameliorated SCI progression, and also to analyze whether lithium affected the expression levels of two representative $GSK-3{\beta}$-associated molecules, nuclear factor erythroid 2-related factor-2 (Nrf-2) and heme oxygenase-1 (HO-1) (a target gene of Nrf-2). Intraperitoneal lithium chloride (80 mg/kg/day for 3 days) significantly improved locomotor function at 8 days post-injury (DPI); this was maintained until 14 DPI (P<0.05). Western blotting showed significantly increased phosphorylation of $GSK-3{\beta}$ (Ser9), Nrf-2, and the Nrf-2 target HO-1 in the spinal cords of lithium-treated animals. Fewer neuropathological changes (e.g., hemorrhage, inflammatory cell infiltration, and tissue loss) were observed in the spinal cords of the lithium-treated group compared with the vehicle-treated group. Microglial activation (evaluated by measuring the immunoreactivity of ionized calcium-binding protein-1) was also significantly reduced in the lithium-treated group. These findings suggest that $GSK-3{\beta}$ becomes activated after SCI, and that a non-specific enzyme inhibitor, lithium, ameliorates rat SCI by increasing phosphorylation of $GSK-3{\beta}$ and the associated molecules Nrf-2 and HO-1.