• Title, Summary, Keyword: hypoxia

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The effects Sunghyangjungkisan-ga-pogongng and herbs on Mouse neuroblastoma 2a cells damaged by hypoxia-reoxygenation (성향정기산가보공영(星香正氣散加補公英)과 단미(單味)들이 Hypoxia-reoxygenation에 의해 손상받은 Mouse Neuroblastoma 2a Cells에 미치는 영향(影響))

  • Yoo, Jin-Suk;Kim, Jong-Woo;Kang, Chul-Hun;Whang, Wei-Wan
    • Journal of Oriental Neuropsychiatry
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    • v.16 no.1
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    • pp.19-41
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    • 2005
  • Object : This study was designed to asses the effect of Sunghyangjungkisan-ga-pogongng and herbs on Mouse neuroblastoma 2a cells damaged by hypoxia-reoxygenation. Method : Mouse neuroblastoma 2a (N2a) cells were measured by MTT assay and LDH assay after 48h hypoxia and 6h reoxygenation, Mouse neuroblastoma 2a (N2a) cells were treated by SHJG+P and herbs. Result : 1. SHJG+P was effective on LDH assay of hypoxia and reoxygenation. 2. The herbs were generally effective on LDH assay of hypoxia and reoxygenation. In MTT assay of hypoxia JP and GC were effecctive. In LDH assay of hypoxia all of herbs were effective. DMH, BC, SY, NS were more effective than other herbs. In LDH assay of reoxygenation KH, BH, BBR, DMH were especially effective. In MTT assay of reoxygenation most of herbs were not effective. But GC, SY, BH, JP were effective. Conclusion : The results imply that SHJG+P and all of berbs may have protective effect on dementia and GC, SY, BH, JP may have protective effect.

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Hypoxia Induced Multidrug Resistance of Laryngeal Cancer Cells via Hypoxia-inducible Factor-1α

  • Li, Da-Wei;Dong, Pin;Wang, Fei;Chen, Xin-Wei;Xu, Cheng-Zhi;Zhou, Liang
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.8
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    • pp.4853-4858
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    • 2013
  • Objectives: To investigate whether hypoxia has an effect on regulation of multidrug resistance (MDR) to chemotherapeutic drugs in laryngeal carcinoma cells and explore the role of hypoxia-inducible factor-$1{\alpha}$ (HIF-$1{\alpha}$). Methods: Laryngeal cancer cells were cultured under normoxic and hypoxic conditions. The sensitivity of the cells to multiple drugs and levels of apoptosis induced by paclitaxel were determined by MTT assay and annexin-V/propidium iodide staining analysis, respectively. HIF-$1{\alpha}$ expression was blocked by RNA interference. The expression of HIF-$1{\alpha}$ gene was detected by real-time quantitative RT-PCR and Western blotting. The value of fluorescence intensity of intracellular adriamycin accumulation and retention in cells was evaluated by flow cytometry. Results: The sensitivity to multiple chemotherapy agents and induction of apoptosis by paclitaxel could be reduced by hypoxia (P<0.05). A the same time, the adriamycin releasing index of cells was increased (P<0.05). However, resistance acquisition subject to hypoxia in vitro was suppressed by down-regulating HIF-$1{\alpha}$ expression. Conclusion: HIF-$1{\alpha}$ could be considered as a key regulator for mediating hypoxia-induced MDR in laryngeal cancer cells via inhibition of drug-induced apoptosis and decrease in intracellular drug accumulation.

Upregulation of HIF-1α by Hypoxia Protect Neuroblastoma Cells from Apoptosis by Promoting Survivin Expression

  • Zhang, Bo;Yin, Cui-Ping;Zhao, Qian;Yue, Shou-Wei
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.19
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    • pp.8251-8257
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    • 2014
  • Apoptosis is one of main types of neural cell death and is reversible and is a major target of therapeutic interventions. However, detailed apoptotic cascades still need to be recognized. In present study, we determined the promotion of HIF-$1{\alpha}$ and survivin in brain samples of a mouse model of hypoxic-ischemia and in neuroblastoma SH-SY5Y cells post hypoxia treatment. Then gain-of-function and loss-of-function strategies were adopted to manipulate the HIF-$1{\alpha}$ in SH-SY5Y cells, and hypoxia-induced survivin upregulation and cell apoptosis were determined. Results demonstrated that the HIF-$1{\alpha}$ and survivin were significantly promoted in a mouse model of hypoxic-ischemia or in SH-SY5Y cells post hypoxia in vitro. Manually upregulated HIF-$1{\alpha}$ could promote the hypoxia-induced survivin upregulation and improve the hypoxia-induced SH-SY5Y cell apoptosis. On the other hand, the HIF-$1{\alpha}$ knockdown by RNAi reduced the hypoxia-induced survivin upregulation and cell apoptosis. Therefore, the present study confirmed the protective role of HIF-$1{\alpha}$ and survivin in the hypoxia-induced SH-SY5Y cell apoptosis, and the survivin upregulation by hypoxia is HIF-$1{\alpha}$-dependent. Promotion of HIF-$1{\alpha}$ and survivin might be a valuable stragegy for therapeutic intervention for hypoxic-ischemic encephalopathy.

Physiological Stress Responses in Black Seabream Acanthopagrus schlegelii Subjected to Acute Hypoxia (저산소 노출에 따른 감성돔(Acanthopagrus schlegelii)의 생리학적 스트레스 반응)

  • Min, Byung Hwa;Park, Mi Seon;Myeong, Jeong-In;Hwang, Hyung Kyu
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.46 no.6
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    • pp.819-826
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    • 2013
  • The black seabream Acanthopagrus schlegelii is an important species for aquaculture in Korea. There are, however, no reports on the physiological responses to hypoxia in this species. The objective of this study was to evaluate the effects of acute hypoxia on the physiological stress responses (plasma cortisol as the primary response, and plasma glucose, hematocrit (Ht), hemoglobin (Hb), sodium, chloride, osmolality, AST, ALT and total protein as the secondary responses) of the fish. The experimental fish were exposed to 0.5 ppm dissolved oxygen (DO) in the seawater via two methods (progressive stepwise decline (Exp. I), and direct decline (Exp. II)). A highly significant increase was detected in plasma cortisol levels due to the hypoxia treatments, and fish in Exp. I had hormone levels that were significantly higher than the fish in Exp. II. For plasma glucose, there was no significant difference between the Exp. I fish and the control fish, whereas Exp. II fish showed significantly higher plasma glucose levels than Exp. I fish and control fish. Ht values increased in both hypoxia treatments; however, Hb concentrations increased only in Exp. I. Although plasma chloride levels were unaffected by acute hypoxia, plasma sodium and osmolality levels increased in Exp. I. Progressive hypoxia (Exp. I fish) increased plasma AST, ALT and total protein. These results suggest that the value and direction of changes to the investigated parameters can be used to determine the resistance of black seabream to acute hypoxia.

Hypoxia Inducible Factor-1α Directly Induces the Expression of Receptor Activator of Nuclear Factor-κB Ligand in Chondrocytes

  • Baek, Kyunghwa;Park, Hyun-Jung;Baek, Jeong-Hwa
    • International Journal of Oral Biology
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    • v.41 no.1
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    • pp.9-15
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    • 2016
  • Receptor activator of nuclear factor-${\kappa}B$ ligand (RANKL) is an osteoblast/stromal cell-derived essential factor for osteoclastogenesis. During endochondral bone formation, hypertrophic chondrocytes calcify cartilage matrix that is subsequently resorbed by osteoclasts in order to be replaced by new bone. Hypoxia-induced upregulation of RANKL expression has been previously demonstrated in an in vitro system using osteoblasts; however, the involved mechanism remains unclear in chondrocytes. In the present study, we investigated whether hypoxia regulates RANKL expression in ATDC5 cells, a murine chondrogenic cell line, and hypoxia-inducible factor-$1{\alpha}$ (HIF-$1{\alpha}$) mediates hypoxia-induced RANKL expression by transactivating the RANKL promoter. The expression levels of RANKL mRNA and protein, as well as HIF-$1{\alpha}$ protein, were significantly increased in ATDC5 cells under hypoxic condition. Constitutively active HIF-$1{\alpha}$ alone significantly increased the levels of RANKL expression under normoxic conditions, whereas dominant negative HIF-$1{\alpha}$ reduced hypoxia-induced RANKL expression. HIF-$1{\alpha}$ increased RANKL promoter reporter activity in a HIF-$1{\alpha}$ binding element-dependent manner in ATDC5 cells. Hypoxia-induced RANKL levels were much higher in differentiated ATDC5 cells, as compared to proliferating ATDC5 cells. These results suggested that under hypoxic conditions, HIF-$1{\alpha}$ mediates induction of RANKL expression in chondrocytes; in addition, hypoxia plays a role in osteoclastogenesis during endochondral bone formation, at least in part, through the induction of RANKL expression in hypertrophic chondrocytes.

Biodistribution and PET imaging of [18F]FMISO in mousecolon cancer xenografted mice

  • Seelam, Sudhakara Reddy;Lee, Ji Youn;Kim, Young Joo;Lee, Yun-Sang;Jeong, Jae Min
    • Journal of Radiopharmaceuticals and Molecular Probes
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    • v.1 no.2
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    • pp.137-144
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    • 2015
  • Hypoxia is an important adverse prognostic factor for tumor progression and is a major cause of failure of radiation therapy. In case of short-term hypoxia, the metabolism can recover to normal, but if hypoxia persists, it causes irreversible cell damage and finally leads to death. So a hypoxia marker would be very useful in oncology. In particular, 2-nitroimidazole can be reduced to form a reactive chemical species, which can bind irreversibly to cell components in the absence of sufficient oxygen, thus, the development of radiolabeled nitroimidazole derivatives for the imaging of hypoxia remains an active field of research to improve cancer therapy result. 2-nitroimidazole based hypoxia marker, [$^{18}F$]FMISO holds promise for the evaluation of tumor hypoxia by Positron emission tomography (PET), at both global and local levels. In the present study, [$^{18}F$]FMISO was synthesized using an automatic synthesis module with high radiochemical purity (>99%) in 60 min. Immunohistochemical analysis using pimonidazole confirmed the presence of hypoxia in xenografted CT-26 tumor tissue. A biodistribution study in CT-26 xenografted mice showed that the increased tumor-to-muscle ratio and tumor-to-blood ratios from 10 to 120 min post-injection. In the PET study, [$^{18}F$]FMISO also showed increased tumor-to-muscle ratios from 10 to 120 min post-injection. In conclusion, this study demonstrates the feasibility and utility of [$^{18}F$]FMISO for imaging hypoxiain mouse colon cancer model using small animal PET.

Effects of Vitamins C and E on Hepatic Drug Metabolizing Function in Nypoxia/Reoxygenation (저산소 및 산소재도입시 vitamin C와 E가 간장 약물대사 기능에 미치는 영향)

  • 윤기욱;이상호;이선미
    • YAKHAK HOEJI
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    • v.44 no.3
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    • pp.237-244
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    • 2000
  • Liver isolated from 18 hours fasted rats was subjected to $N_2$hypoxia (for 45 min) followed by reoxygenation (for 30 min). The perfusion medium used was Krebs-Henseleit bicarbonate buffer (pH 7.4, $37^{\circ}C$). Vitamin C (0.5 mM) and trolox C (0.5 mM), soluble vitamin E analog, were added to perfusate. Lactate dehydrogenase (LDH), total glutathione, oxidized glutathione, lipid peroxide and drug-metabolizing enzymes were measured. After hypoxia LDH significantly increased but this increase was attenuated by vitamin C and combination of vitamin C and E. Total glutathione and oxidized glutathione in perfusate markedly increased during hypoxia and this increase was inhibited by vitamins C, E and its combination. Similarly; oxidized glutathione and lipid peroxide in liver tissue increased after hypoxia and reoxygenation and this increase was inhibited by vitamin I and combination of vitamin C and E. Hepatic drug metabolizing function (phase I, II) were suppressed during hypoxia but improved during reoxygenation. While vitamins C and E only increased glucuronidation, the combination of vitamin C and E increased the oxidation, glucuronidation and sulfation. Our findings suggest that vitamins C and E synergistically ameliorates hepatocellular damage as indicated by abnormalities in drug metabolizing function during hypoxia/reoxygenation and that this protection is in major part, caused by decreased oxidative stress.

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Effect of vitamin C on hepatic drug metabolism in hypoxia/reoxygenation

  • Lee, Hae-;Jung, Ju-Yeon;Han, Suck-Hee;Cho, Tai-Soon;Lee, Sun-Mee
    • Proceedings of the Korean Society of Applied Pharmacology
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    • pp.191-191
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    • 1998
  • It has been hypothesized that formation of oxygen-derived free radicals may play an important part in ischemically induced tissue injury. In this study, the effects of vitamin C treatment on hepatic reperfusion model were investigated. Livers isolated from 18 hrs fasted rats were subjected to low flow hypoxia (1 $m\ell$/g liver/min, for 45min) followed by reoxygenation (for 30min). The perfusion medium used was Krebs-Henseleit bicarbonate buffer (KHBB, pH 7.4) and vitamin C (0.25, 0.5, 1.0 and 2.0 mM) was added to perfusate. 7-Ethoxycoumarin was used as substrate of phase and metbolism. After hypoxia oxygen consumption significantly dropped but vitamin C 0.25, 0.5 and 1.0 mM treatments restored oxygen consumption to the level of control group. LDH and lipid peroxidation were not changed in all experimental groups. Oxidation, phase metabolism, significantly decreased following hypoxia but improved during reoxygenation. Vitamin C 0.25 mM treatment significantly improved the oxidation of 7-ethoxycoumarin during hypoxia and reoxygenation, but the oxidation significantly decreased by vitamin C 2.0 mM treatment. Similarly, sulfate conjugation decreased in hypoxic group, but this decrease was inhibited by vitamin C 0.25, 0.5 and 1.0 mM treatments. Our findings suggest that hypoxia/reoxygenation diminishes hepatic drug metabolizing function, vitamin C at concentration of 0.25-1.0 mM ameliorates but at higher concentration aggravates these hypoxia/reoxygenation-induced changes.

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Oxygen matters: hypoxia as a pathogenic mechanism in rhinosinusitis

  • Cho, Hyung-Ju;Kim, Chang-Hoon
    • BMB Reports
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    • v.51 no.2
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    • pp.59-64
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    • 2018
  • The airway epithelium is the first place, where a defense mechanism is initiated against environmental stimuli. Mucociliary transport (MCT), which is the defense mechanism of the airway and the role of airway epithelium as mechanical barriers are essential in innate immunity. To maintain normal physiologic function, normal oxygenation is critical for the production of energy for optimal cellular functions. Several pathologic conditions are associated with a decrease in oxygen tension in airway epithelium and chronic sinusitis is one of the airway diseases, which is associated with the hypoxic condition, a potent inflammatory stimulant. We have observed the overexpression of the hypoxia-inducible factor 1 (HIF-1), an essential factor for oxygen homeostasis, in the epithelium of sinus mucosa in sinusitis patients. In a series of previous reports, we have found hypoxia-induced mucus hyperproduction, especially by MUC5AC hyperproduction, disruption of epithelial barrier function by the production of VEGF, and down-regulation of junctional proteins such as ZO-1 and E-cadherin. Furthermore, hypoxia-induced inflammation by HMGB1 translocation into the cytoplasm results in the release of IL-8 through a ROS-dependent mechanism in upper airway epithelium. In this mini-review, we briefly introduce and summarize current progress in the pathogenesis of sinusitis related to hypoxia. The investigation of hypoxia-related pathophysiology in airway epithelium will suggest new insights on airway inflammatory diseases, such as rhinosinusitis for clinical application and drug development.

Protective Effects of Palmul-tang on Hypoxia-induced Apoptosis in H9c2 Cardiomyoblast Cells (팔물탕이 저산소증에 의한 배양심근세포고사에 미치는 영향)

  • 임은경;신선호
    • The Journal of Korean Medicine
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    • v.25 no.2
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    • pp.67-76
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    • 2004
  • Objectives : This study was designed to investigate the protective mechanisms of Palmul-tang on hypoxia-induced cytotoxicity in H9c2 cardiomyoblast cells. Methods : In this study, we used H9c2 cells. Cells were subjected to hypoxia in the absence and presence of $1000\mu\textrm{g}/ml$ Palmul-tang for 24 hrs. Cells were treated with various concentrations of Palmul-tang for 24 hrs. Cell viability was measured by MTT assay. Hypoxia markedly decreased the viability of H9c2 cells, which was characterized with apparent apoptotic features such as chromatin condensation as well as fragmentation of genomic DNA and nuclei. Results : Palmul-tang significantly reduced hypoxia-induced cell death and apoptotic characteristics. Also, Palmul-tang prevented mitochondrial dysfunction including the disruption of mitochondrial membrane permeability transition (MPT) and an increase in expression of apoptogenic Bcl-2 proteins in hypoxia-H9c2 cells. Conclusions; This study suggests that the protective effects of Palmul-tang against hypoxic damages may be mediated by the modulation of Bcl-2, Bax expression.

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