• Molecules and Cells
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• 제22권2호
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• pp.203-209
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• 2006

TBP (TATA-binding protein)-related factor 2 (TRF2) regulates transcription during a nuber of cellular processes. We previously demonstrated that it is localized in the cytoplasm and is translocated to the nucleus by DNA-damaging agents. However, the cytoplasmic localization of TRF2 is controversial. In this study, we reconfirmed its cytoplasmic localization in various ways and examined its nuclear migration. Stresses such as heat shock, redox agents, heavy metals, and osmotic shock did not affect localization whereas genotoxins such as methyl methanesulfonate (MMS), cisplatin, etoposide, and hydroxyurea caused it to migrate to the nucleus. Adriamycin, mitomycin C and ${\gamma}$-rays had no obvious effect. We determined optimal conditions for the nuclear migration. The proportions of cells with nuclei enriched for TRF2 were 25-60% and 5-10% for stressed cells and control cells, respectively. Nuclear translocation was observed after 1 h, 4 h and 12 h for cisplatin, etoposide and MMS and hydroxyurea, respectively. The association of TRF2 with the chromatin and promoter region of the proliferating cell nuclear antigen (PCNA) gene, a putative target of TRF2, was increased by MMS treatment. Thus TRF2 may be involved in genotoxin-induced transcriptional regulation.

• The Korean Journal of Physiology and Pharmacology
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• 제18권5호
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• pp.403-409
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• 2014

The Bis protein is known to be involved in a variety of cellular processes including apoptosis, migration, autophagy as well as protein quality control. Bis expression is induced in response to a number of types of stress, such as heat shock or a proteasome inhibitor via the activation of heat shock factor (HSF)1. We report herein that Bis expression is increased at the transcriptional level in HK-2 kidney tubular cells and A172 glioma cells by exposure to oxidative stress such as $H_2O_2$ treatment and oxygen-glucose deprivation, respectively. The pretreatment of HK-2 cells with N-acetyl cysteine, suppressed Bis induction. Furthermore, HSF1 silencing attenuated Bis expression that was induced by $H_2O_2$, accompanied by increase in reactive oxygen species (ROS) accumulation. Using a series of deletion constructs of the bis gene promoter, two putative heat shock elements located in the proximal region of the bis gene promoter were found to be essential for the constitutive expression is as well as the inducible expression of Bis. Taken together, our results indicate that oxidative stress induces Bis expression at the transcriptional levels via activation of HSF1, which might confer an expansion of antioxidant capacity against pro-oxidant milieu. However, the possible role of the other cis-element in the induction of Bis remains to be determined.

• Biomolecules & Therapeutics
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• 제23권2호
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• pp.128-133
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• 2015

Although coffee is known to have antioxidant, anti-inflammatory, and antitumor properties, there have been few reports about the effect and mechanism of coffee compounds in colorectal cancer. Heat shock proteins (HSPs) are molecular chaperones that prevent cell death. Their expression is significantly elevated in many tumors and is accompanied by increased cell proliferation, metastasis and poor response to chemotherapy. In this study, we investigated the cytotoxicity of four bioactive compounds in coffee, namely, caffeine, caffeic acid, chlorogenic acid, and kahweol, in HT-29 human colon adenocarcinoma cells. Only kahweol showed significant cytotoxicity. Specifically, kahweol increased the expression of caspase-3, a pro-apoptotic factor, and decreased the expression of anti-apoptotic factors, such as Bcl-2 and phosphorylated Akt. In addition, kahweol significantly attenuated the expression of HSP70. Inhibition of HSP70 activity with triptolide increased kahweol-induced cytotoxicity. In contrast, overexpression of HSP70 significantly reduced kahweol-induced cell death. Taken together, these results demonstrate that kahweol inhibits colorectal tumor cell growth by promoting apoptosis and suppressing HSP70 expression.

• Biomolecules & Therapeutics
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• 제26권6호
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• pp.576-583
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• 2018

Human rhinoviruses (HRV) are one of the major causes of common cold in humans and are also associated with acute asthma and bronchial illness. Heat-shock protein 90 (Hsp90), a molecular chaperone, is an important host factor for the replication of single-strand RNA viruses. In the current study, we examined the effect of the Hsp90 inhibitor pochonin D, in vitro and in vivo, using a murine model of human rhinovirus type 1B (HRV1B) infection. Our data suggested that Hsp90 inhibition significantly reduced the inflammatory cytokine production and lung damage caused by HRV1B infection. The viral titer was significantly lowered in HRV1B-infected lungs and in Hela cells upon treatment with pochonin D. Infiltration of innate immune cells including granulocytes and monocytes was also reduced in the bronchoalveolar lavage (BAL) by pochonin D treatment after HRV1B infection. Histological analysis of the lung and respiratory tract showed that pochonin D protected the mice from HRV1B infection. Collectively, our results suggest that the Hsp90 inhibitor, pochonin D, could be an attractive antiviral therapeutic for treating HRV infection.

• The Korean Journal of Physiology and Pharmacology
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• 제12권4호
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• pp.171-176
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• 2008

Heat shock proteins (HSPs) serve as molecular chaperones and play a role in cell protection from damage in response to stress stimuli. The aim of this article is to investigate whether HSP22 affects IL-8 expression in vascular smooth muscle cells (VSMCs), and which cellular factors are involved in the HSP-mediated IL-8 induction in that cell type in terms of mitogen activated protein kinase (MAPK) and transcription element. Exposure of aortic smooth muscle cells (AoSMCs) to HSP22 not only enhanced IL-8 release but also induced IL-8 transcript via promoter activation. HSP22 activated ERK and p38 MAPK in AoSMCs. HSP22-induced IL-8 release was inhibited by U0126, but not by SB202190. A mutation in the IL-8 promoter region at the binding site of NF-${\kappa}$ B, but not AP-1 or C/EBP, impaired promoter activation in response to HSP22. Delivery of I ${\kappa}$ B, but not dominant negative c-Jun, lowered HSP22-induced IL-8 release from AoSMCs. These results suggest that HS P22 induces IL-8 in VSMCs via ERK1/2, and that transcription factor NF-kB may be required for the HSP22-induced IL-8 up-regulation.

• Molecules and Cells
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• 제39권6호
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• pp.477-483
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• 2016

Heat shock factors (Hsfs) are central regulators of abiotic stress responses, especially heat stress responses, in plants. In the current study, we characterized the activity of the Hsf gene HsfA3 in Arabidopsis under oxidative stress conditions. HsfA3 transcription in seedlings was induced by reactive oxygen species (ROS), exogenous hydrogen peroxide ($H_2O_2$), and an endogenous $H_2O_2$ propagator, 2,5-dibromo-3-methyl-6-isopropyl-p-benzoquinone (DBMIB). HsfA3-overexpressing transgenic plants exhibited increased oxidative stress tolerance compared to untransformed wild-type plants (WT), as revealed by changes in fresh weight, chlorophyll fluorescence, and ion leakage under light conditions. The expression of several genes encoding galactinol synthase (GolS), a key enzyme in the biosynthesis of raffinose family oligosaccharides (RFOs), which function as antioxidants in plant cells, was induced in HsfA3 overexpressors. In addition, galactinol levels were higher in HsfA3 overexpressors than in WT under unstressed conditions. In transient transactivation assays using Arabidopsis leaf protoplasts, HsfA3 activated the transcription of a reporter gene driven by the GolS1 or GolS2 promoter. Electrophoretic mobility shift assays showed that GolS1 and GolS2 are directly regulated by HsfA3. Taken together, these findings provide evidence that GolS1 and GolS2 are directly regulated by HsfA3 and that GolS enzymes play an important role in improving oxidative stress tolerance by increasing galactinol biosynthesis in Arabidopsis.

• 한국미생물·생명공학회지
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• 제33권4호
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• pp.308-314
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• 2005

상용 복막투석액에 함유된 고농도의 포도당과 포도당 분해산물(glucose degradation products: CDP)이 복막의 비후, 복막 투과성의 증가 및 한외여과 부전과 같은 복막의 구조적, 기능적 변화를 초래하리라 추정되고 있다. 본 연구에서는 CDP성분이 사람 복막중피세포 활성화에 미치는 영향을 검색하였고 또 이때 ROS와 PKC가 관여하는지를 검색하였다. 혈청이 배제된 M199 배양액으로 성장을 동일화시킨 사람 복막중피세포를 GDP인 methylglyoxal(MGO), acetaldehyde, 그리고 3,4-dioxyglucosone-3-ene(3,4-DGE)으로 48시 간 동안 자극하였고, 복막의 투과성에 대한 지표로서 혈관내피성장인자(vascular endothelial growth factor VEGF)를, 섬유화의 지표로서 fibronectin과 heat shock protein 47(hsp47)의 단백을 정량하였다. 활성산소족(reactive oxygen species:ROS)과 protein kinase C(PKC)의 관여여부는 각각 항산화제 N-acetylcystein(NAC)과 PKC 억제제 calphostin C의 억제 효과로 검색하였다. MGO는 대조군과 비교하여 VEGF 분비를 1.9배, fibronectin분비를 1.5배 그리고 hsp47 표현을 1.3배로 유의하게 증가시켰다(p<0.05). MGO에 의한 VEGF 상향 조절은 calphostin C와 NAC에 의하여 유의하게 억제되었다. 사람 복막중피세포에서 VEGF 분비는 acetaldehyde에 의하여 증가하였으나 3,4-DGE에 의하여 억제되었고, fibronectin 분비와 hsp47 표현은 acetaldehyde나 3,4-DGE에 의하여 영향을 받지 않았다. 이상을 종합할 때, ROS생산과 PKC활성화가 상용투석액내 함유된 MGO에 의한 점진적인 복막의 투과성 증가, 세포외기질 축적 그리고 복막 섬유화를 유발하는 주된 신호체계로서 이를 선택적으로 억제함으로써 복막의 기능을 유지할 수 있을 것으로 생각된다.

• The Korean Journal of Physiology and Pharmacology
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• 제24권3호
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• pp.241-248
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• 2020

Luminespib (AUY922), a heat shock proteins 90 inhibitor, has anti-neoplastic and antitumor effects. However, it is not clear whether AUY922 affects events in vascular diseases. We investigated the effects of AUY922 on the platelet-derived growth factor (PDGF)-BB-stimulated proliferation and migration of vascular smooth muscle cells (VSMC). VSMC viability was detected using the XTT (2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide) reagent. To detect the attenuating effects of AUY922 on PDGF-BB-induced VSMCs migration in vitro, we performed the Boyden chamber and scratch wound healing assays. To identify AUY922-mediated changes in the signaling pathway, the phosphorylation of protein kinase B (Akt) and extracellular signal-regulated kinase (ERK) 1/2 was analyzed by immunoblotting. The inhibitory effects of AUY922 on migration and proliferation ex vivo were tested using an aortic ring assay. AUY922 was not cytotoxic at concentrations up to 5 nM. PDGF-BB-induced VSMC proliferation, migration, and sprout outgrowth were significantly decreased by AUY922 in a dose-dependent manner. AUY922 significantly reduced the PDGF-BB-stimulated phosphorylation of Akt and ERK1/2. Furthermore, PD98059 (a selective ERK1/2 inhibitor) and LY294002 (a selective Akt inhibitor) decreased VSMC migration and proliferation by inhibiting phosphorylation of Akt and ERK1/2. Greater attenuation of PDGF-BB-induced cell viability and migration was observed upon treatment with PD98059 or LY294002 in combination with AUY922. AUY922 showed anti-proliferation and anti-migration effects towards PDGF-BB-induced VSMCs by regulating the phosphorylation of ERK1/2 and Akt. Thus, AUY922 is a candidate for the treatment of atherosclerosis and restenosis.

• Tuberculosis and Respiratory Diseases
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• 제52권4호
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• pp.355-366
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• 2002

연구배경: 열 전처치는 조직 내에 열충격단백질의 생성을 유도하며 이러한 열 전처치가 내독소로 유도된 쥐의 급성폐손상을 감소시키고 패혈증에 의한 사망률을 감소시킨다고 알려져 있다. 그러나, 폐손상을 유발하는 원인에 노출된 후 가해진 열처치가 폐손상에 미치는 효과에 대하여는 아직까지 잘 알려져 있지 않다. 따라서 본 연구는 내독소 투여 직후 시행한 열충격이 내독소에 의해 유발된 쥐의 급성폐손상에 미치는 영향과 그에 따른 염증성 및 항염증성 사이토카인에 미치는 영항을 알아보고자 하였다. 방 법: 대조군은 백서의 기관지 내로 생리식염수를 투여하였고 열처치 대조군은 생리식염수 투여 직후 열처치를 시행하였다. 내독소군은 열처치 없이 내독소를 기관지내로 투여하였다. 열 전처치군은 내독소 투여 18시간 전에 열 전처치를 시행하였고, 열 동시처치 군은 내독소 투여 직후 열처치를 시행하였다. 내독소 투여 후 6시간에 기관지폐포세척을 시행하여 기관지폐포세척액 내의 호중구 백분율을 측정하였고 폐를 적출하여 myeloperoxidase(MPO)의 활성도를 측정하였으며 기관지폐포세척액과 혈청에서 LDH(lactic dehydrogenase), 단백질, IL(interleukin)-$1{\beta}$, TNF(tumor necrosis factor)-${\alpha}$ 및 IL-10를 측정하였다. 또한 각군에서 폐 조직 내 HSP72의 표현정도를 관찰하였다. 결 과: 1) 내독소군, 열 전처치군 및 열 동시처치군 모두에서 기관지폐포세척액 내의 호중구 백분율, 폐조직이 MPO, 혈청 및 기관지폐포세척액내의 $IL-1{\beta}$, $TNF-{\alpha}$ 및 IL-10이 대조군에 비해 증가하였다(각 p<0.05). 2) 열 동시처치군은 폐조직의 MPO와 기관지폐포세척액 단백질의 농도가 내독소군과 차이가 없었고 기관지폐포세척액의 LDH가 내독소군에 비해 증가하였다(p<0.05). 3) 열 동시처치군의 혈청 $TNF-{\alpha}$의 농도는 내독소군과 비교 시 증가하였다(p=0.01). 결 론: 내독소 투여 직후 시행한 열충격은 내독소로 유도되는 폐손상을 감소시키지 못하며 염증성 사이토카인의 농도를 증가시켰다.

• 한국안전학회지
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• 제6권2호
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• pp.31-36
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• 1991

Quenching effects of acetylene and hydrogen into oxygen detonation by using detonation arrester ［DA］are studied in this paper. The experiments were carried out in cylinderical shock tube. 5m long, 30mm dia., with stolchlometric ratio ［SR］of each gas and 10-l20$\mu$ Cell Size of brass and Stainless Steel of DAs were installed in it To clarify arresting ability correlation with initial pressure, Pi, critical thickness, Tct, and shapes of supporting panel of DA are also investigated It is found that ­detonation velocities has most dependency on Pi, it shows notable changes around 0.5kgf/$\textrm{cm}^2$ for hydrogen, 0.15kgf/$\textrm{cm}^2$ for acetylen respectively, ­DA can be safety device able to arrest shock wave of detonation, ­over Tct flame transmission might be only the factor has to be considered, ­acetylene seems to be much more stronger detonation characteristics than hydrogen because of reaction heat.