• 생명과학회지
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• 제16권6호
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• pp.1052-1059
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• 2006

다양한 종류의 박테리아에서부터 사람의 세포에 이르기까지 환경적인 스트레스나 병에 의한 스트레스 혹은 스트레스가 없는 상황에서도 열충격반응(heat shock response) 유도되어진다. 열충격반응에 노출된 세포에서는 모든 단백질의 발현이 정지되는 반면, 열충격단백질(heat shock proteins: HSPs)은 발현되어 스트레스로부터 세포를 보호한다. HSF1(heat shock factor 1)이라는 HSPs 유도단백질은 열충격반응시 단량체형태에서 삼중체의 형태로 구조변화를 일으켜 heat shock element(HSE)라고 불리우는 HSP gene의 발현 promoter에 특이적으로 결합하게 되어 HSPs를 발현시킨다. Human HSF1(hHSF1)은 다섯 개의 시스테인 잔기를 가지고 있는데 이 시스테인의 thiol(-SH)기는 강한 친전자성을 띔으로 급격히 산화되거나 질산화된다. 이러한 고찰은 시스테인 잔기가 산화 환원 의존적인 황산기/이황화결합 전환을 통해 구조적인 변화를 가져온다는 사실을 의미하고 있다. 따라서 본 연구에서는 여러 가지 산화환원제를 이용하여 HSF1에 존재하는 다섯 개의 시스테인 잔기의 역할과 삼량체 형성에 관여하는 잔기에 대하여 알아보고자 하였다. 또한 이황화결합을 통한 삼량체형성의 구조적변화의 관점에서 HSF1의 구조 변화와 DNA 결합력과의 상관관계에 관하여도 알아보고자 하였다. 본 연구결과로 HSF1의 DNA binding domain은 삼량체를 형성하는 구조적인 변화를 통해서 DNA에 대한 결합력이 증가되는 것을 알 수 있었는데 이것은 삼량체가 됨으로서 HSF1의 내부에 위치해 있던 DNA binding domain이 외부로 노출 되어져 DNA에 쉽게 결합할 수 있게 된다는 사실을 시사한다.

• 동의생리병리학회지
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• 제21권1호
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• pp.93-97
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• 2007

We previously reported the anti-proliferative effect of Chungjogupae-tang (CJGPT) in human lung carcinoma A549 cells, which was associated with the induction of cyclin-dependent kinase inhibitor p21 in a tumor suppressor p53-independent manner. CJGPT treatment also resulted in the inhibition of prostaglandin E2 release A549 cells by the down-regulation of cyclooxygenase-2. In the present study, we investigated the pathway of the induction of apoptotic cell death by CJGPT in A549 cells. It was found that CJGPT could inhibit the cell viability and induce the apoptotic cell death of A549 cells in a dose-dependent manner as measured by hemocytometer counts, flow cytometry analysis and agarose gel electrophoresis. Apoptosis of A549 cells by CJGPT was associated with a down-regulation of anti-apoptotic Bcl-2 and inhibitor of apoptosis proteins (IAPs) expression. Additionally, DNA fragmentation by CJGPT was connected with the activation of inhibitor of caspase-activated DNase/DNA fragmentation factor 45 (ICAD/DFF45) protein expression.

• 미생물학회지
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• 제51권3호
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• pp.249-255
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• 2015

철 스트레스($2{\mu}M$ 이하 농도) 하에서 시데로포어를 생산하는 균주를 토양에서 분리하여 16S rDNA 염기 서열 분석과 생화학적, 생리학적 분석 및 전자 현미경 관찰 등으로 동정한 결과, Acinetobacter sp.로 밝혀졌다. 시데로포어의 카테콜 특성은 Arnow법으로 조사되었다. 철을 제한한 배지에서 균주를 배양한 결과, $36^{\circ}C$에서도 잘 자랐지만 시데로포어 생산은 $28^{\circ}C$에서 높았다. $36^{\circ}C$에서는 시데로포어 생산이 강하게 억제되었다. $10{\mu}M\;FeCl_3$를 첨가한 배지에서는 시데로포어 생산이 완전히 억제되었다. 균주 상등액을 부탄올 추출 후, Sephadex LH-20 컬럼 크로마토그래피와 HPLC를 이용하여 시데로포어를 분리, 정제하였다. 분리, 정제된 시데로포어의 구조는 HPLC, TLC와 IR 분석 결과로부터 2,3-dihydroxybenzoic acid로 확인되었다.

• 동의생리병리학회지
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• 제18권4호
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• pp.1173-1178
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• 2004

Gagamhwanglyeonhaedog-tang(GHH), a Korean genuine medicine, is a newly designed herbal drug formula based on the traditional oriental pharmacological knowledge for the purpose of treating tumorous diseases. Apoptosis is an evolutionarily conserved suicide program residing in cells. It leads to cell death through a tightly regulated process resulting in the removal of damaged or unwanted tissue. In the present study, the apoptosis inducing activities of the decocted water extract of GHH were studied. Results of the 3- [4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay showed that GHH had a strong cytotoxic effect on HL-60 cells. The number of live cells was less than 20% after exposure to 1㎎/㎖ GHH for 48 hr. GHH increased cytotoxicity of HL-60 cells in a dose- and time­dependent manner. Cell apoptosis by GHH was confirmed by flow cytometric analysis of the DNA-stained cells. The percentage of apoptotic cells increased to 28%, 31% and 37% 24 hr and 37%, 44% and 81% 48 hr after treatment with 0.01, 0.1 and 1㎎/㎖ GHH, respectively. Flow cytometric analysis of GHH treated HL-60 cells showed increase of hypodiploid apoptotic cells in a dose- and time- dependent manner. DNA fragmentation also occurred in apoptosis and was characterized by a ladder pattern on agarose gel. In addition, GHH (0.01 and 0.1㎎/㎖) increased the secretion of tumor necrosis factor-alpha in 24 and 48 hr. The author showed that GHH-induced apoptosis was accompanied by activation of caspase-3. These results suggest that GHH induces activation of caspase-3 and eventually leads to apoptosis.

• 동의생리병리학회지
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• 제19권1호
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• pp.234-241
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• 2005

Galla Rhois is a nest of parasitic bug, Mellaphis chinensis Bell, in Rhus chinensis Mill. Galla Rhois has been used for the therapy of diarrhea, peptic ulcer, hemauria, etc., that showed various antiinflammatory activity, and other biological properties. We studied the effect of Galla Rhois water extract(GRWE). The cytotoxic activity of GRWE in HL-60 cells was increased in a concentration-dependent manner. GRWE was cytotoxic to HL-60 cells, with $IC_50$ of $100{\mu}g/m{\ell}$. Treatment of GRWE to HL-60 cells showed the fragmentation of DNA in a concentration manner, suggesting that these cells underwent apoptosis. In addition, the flow cytometric analysis revealed GRWE concentration-dependently increased apoptotic cells with hypodiploid DNA content and arrested G1 phase of cell cycle. These results indicate that GRWE may have a possibility of potential anticancer activities. Treatment of HL-60 cells with GRWE was induced activation of caspase-3, caspase-8 and proteolytic cleavage of poly(ADP-ribose) polymerase. Also, caspase-3 was directly activated via caspase-8 activation. GRWE also caused the release of cytochrome c from mitochondria into the cytosol. GRWE-induced cytochrome c release was mediated by caspase-8-dependent cleavage of Bid and Bax translocation. These results suggest that caspase-8 mediates caspase-3 activation and cytochrome c release during GRWE-induced apoptosis in HL-60 cells.

• 동의생리병리학회지
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• 제25권5호
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• pp.857-862
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• 2011

The purpose of this study is to investigate the anti-proliferative mechanism by Trichosanthes kirilowii (TCK) in MCF-7 human breast carcinoma cell. In this study, we used human breast cancer cell line, Michigan cancer foundation-7 cells (MCF-7 cells). They were co-incubated with 30~200 ${\mu}g$/ml TCK for 48 hours, and cell viability was measured by Water-soluble tetrazolium salt-1 (WST-1) assay. After MCF-7 cells were exposed to 60 ${\mu}g$/ml of TCK for 0, 3, 6, 12, 24, 48 hours, We performed flow analysis cytometry sorting(FACS) and western blot analysis. We investigated the effect of dose-dependent cell growth inhibition by TCK, which could be proved by WST-1 assay. Also, flow cytometry analysis showed that TCK increased percentage of subG1 phase and G2/M phase cell cycle. In addition, TCK induced apoptosis through the expression of caspase-9, -3 and poly(ADP-ribose) polymerase(PARP) activation. Moreover, we showed that ATM-dependent G2/M phase arrest by DNA damage and phosphorylation of chk2, cdc25C, cdc2(Tyr15). Taken together, these results suggest that by G2/M phase arrest through DNA damage and inducing of apoptosis through intrinsic pathway, TCK may have potential tumor suppressor in breast cancer.

• Biomolecules & Therapeutics
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• 제13권4호
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• pp.207-213
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• 2005

It has been proposed that reactive oxygen species (ROS), mainly superoxide anion ($O_2^-$) and hydrogen peroxide ($H_2O_2$), may mediate oxidative stress. Production of $H_2O_2$ during oxidative phosphorylation, inflammation, and ischemia can cause oxidative stress leading to cell death. Although glucose oxidase (GOX) in the presence of glucose continuously generates $H_2O_2$, it is not clear whether GOX produces apoptotic cell death in C6 glial cells. Thus, we investigated the mechanism by which GOX induces cell death. Cells were incubated with different concentration of GOX in the presence of glucose where cell viability, TUNEL and DNA ladder were analyzed. Results indicated that GOX exhibited cytotoxicity in a dose dependent manner by MTT assay. TUNEL positive cell and DNA laddering showed that GOX-induced cytotoxicity was due to apoptosis. Western blot analysis also showed that the cleaved caspase-3 level was detected in the GOX-treated cells at 10 mU/ml and increased dramatically at 30 mU/ml. Cleaved PARP also appeared at 10 mU/ml and lasted at 20 or 30 mU/ml of GOX. Cytochrome c level was increased by GOX dose dependently, which was contrast to Bcl-2 expression level. These results suggest that GOX induces apoptosis through caspase-3 activation, which followed by cytochrome c release from mitochondria through regulating of Bcl-2 level.

• Biomolecules & Therapeutics
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• 제24권3호
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• pp.268-282
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• 2016

In the present study, we investigated the anti-inflammatory properties of Eucommia ulmoides Oliv. Bark. (EUE) in lipopolysaccharide (LPS)-stimulated microglial BV-2 cells and found that EUE inhibited LPS-mediated up-regulation of pro-inflammatory response factors. In addition, EUE inhibited the elevated production of pro-inflammatory cytokines, mediators, and reactive oxygen species (ROS) in LPS-stimulated BV-2 microglial cells. Subsequent mechanistic studies revealed that EUE suppressed LPS-induced phosphorylation of mitogen-activated protein kinases (MAPKs), phosphoinositide-3-kinase (PI3K)/Akt, glycogen synthase $kinase-3{\beta}$ ($GSK-3{\beta}$), and their downstream transcription factor, nuclear factor-kappa B ($NF-{\kappa}B$). EUE also blocked the nuclear translocation of $NF-{\kappa}B$ and inhibited its binding to DNA. We next demonstrated that EUE induced the nuclear translocation of nuclear factor erythroid 2-related factor 2 (Nrf2) and upregulated heme oxygenase-1 (HO-1) expression. We determined that the significant up-regulation of HO-1 expression by EUE was a consequence of Nrf2 nuclear translocation; furthermore, EUE increased the DNA binding of Nrf2. In contrast, zinc protoporphyrin (ZnPP), a specific HO-1 inhibitor, blocked the ability of EUE to inhibit NO and $PGE_2$ production, indicating the vital role of HO-1. Overall, our results indicate that EUE inhibits pro-inflammatory responses by modulating MAPKs, PI3K/Akt, and $GSK-3{\beta}$, consequently suppressing $NF-{\kappa}B$ activation and inducing Nrf2-dependent HO-1 activation.

• Biomolecules & Therapeutics
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• 제15권2호
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• pp.95-101
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• 2007

Resveratrol (3,5,4’-trihydroxy-trans-stilbene), a naturally occurring phytoallexin abundant in grapes and several plants, has been shown to be active in inhibiting proliferation and inducing apoptosis in several human cancer cell lines. On the line of the biological activity of resveratrol, a variety of resveratrol analogs were synthesized and evaluated for their growth inhibitory effects against several human cancer cell lines. In the present study, we found that one of the resveratrol analogs, 3,4,5-trimethoxy-4’-bromo-cis-stilbene, markedly suppressed human colon cancer cell proliferation (EC$_{50}$ = 0.01 ${\mu}$g/ml), and the inhibitory activity was superior to its corresponding trans-isomer (EC$_{50}$ = 1.6 ${\mu}$g/ml) and resveratrol (EC$_{50}$ = 18.7 ${\mu}$g/ml). Prompted by the strong growth inhibitory activity in cultured human colon cancer cells (Col2), we investigated its mechanism of action. 3,4,5-Trimethoxy-4’-bromo-cis-stilbene induced arrest of cell cycle progression at G2/M phase and increased at sub-G1 phase DNA contents of the cell cycle in a time- and dose-dependent manner. Colony formation was also inhibited in a dose-dependent manner, indicating the inhibitory activity of the compound on cell proliferation. Moreover, the morphological changes and condensation of the cellular DNA by the treatment of the compound were well correlated with the induction of apoptosis. These data suggest the potential of 3,4,5-trimethoxy-4’-bromo-cis-stilbene might serve as a cancer chemotherapeutic or chemopreventive agent by virtue of arresting the cell cycle and inducing apoptosis for the human colon cancer cells.

• Toxicological Research
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• 제19권2호
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• pp.91-98
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• 2003

Alkylating agents form alkylated base adducts in the DNA and cause DNA lesions leading to cell killing. In this study, we investigated the mechanism of apoptosis induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) in PC-3 and DU145 human prostate carcinoma cell lines. MNNG treatment resulted in the inhibition of cell proliferation in a concentration-dependent manner to a similar extent in both cell lines. This anti-proliferative effect of PC-3 and DU145 cells by MNNG was associated with morphological changed such as membrane shrinking, cell rounding up and formation of apoptotic bodies. MNNG treatment also induced a proteolytic cleavage of specific target proteins such as poly(ADP-ribose) polymerase (PARP) and $\beta$-catenin proteins in DU145 cells but in PC-3 cells. Furthermore, we observed an increase of proapoptotic protein Bax family expression and a decrease of antiapoptotic protein Bcl-2 family by MNNG treatment in a concentration-dependent manner MNNG also induced a proteolytic activation of caspase-3 and -9, which is believed to play a central role in the apoptotic signaling pathway.