• Journal of Microbiology and Biotechnology
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• 제24권5호
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• pp.696-703
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• 2014

Clostridium difficile causes mucosal damage and diarrhea by releasing two exotoxins: toxin A and toxin B. C. difficile colitis is associated with alterations in bowel flora and the failure to mount an effective antibody response. The aim of the current study was to investigate whether antitoxin sera prevent toxin-A-induced apoptosis, cytoskeletal disaggregation, cell detachment, and tight junction loss in cultured colonic epithelial cells. Serum samples were isolated from mice that survived a C. difficile infection following antibiotic treatment, and the antitoxin effects of these samples were investigated in toxin-A-exposed HT29 colonic epithelial cells and a toxin-A-induced animal model of gut inflammation. Unchallenged mice did not produce IgG against toxin A, whereas serum (antiserum) from C. difficile-challenged mice showed significant IgG responses against toxin A. Treatment with the antiserum markedly inhibited mucosal damage and inflammation in the toxin-A-treated mouse model. In contrast to control mouse serum, the antiserum also markedly inhibited toxin-A-induced DNA fragmentation, dephosphorylation of paxillin and Epo receptor (EpoR), deacetylation of tubulin, and upregulation of p21(WAF1/CIP1) and p53. Taken together, these results reveal that the generated antitoxin serum has biotherapeutic effects in preventing various C. difficile toxin-A-induced cellular toxicities.

• 한국해양바이오학회지
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• 제1권2호
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• pp.76-83
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• 2006

본 연구에서는 다양한 인체암세포의 증식에 미치는 등불가사리 메탄올 추출물(MEGF)의 영향을 조사하였다. MEGF는 처리 농도의존적으로 암세포의 형태적변이 및 증식억제가 효과를 보여주었으며, 특히 백혈병세포에서 가장 높은 감수성을 보여주었다. 따라서 백혈병세포의 증식억제 효과가 apoptosis 유발과 연관성이 있는지를 flow cytometry 분석 및 DAPI staining 법으로 조사한 결과, MEGF 처리에 의한 백혈병세포의 증식억제는 세포주기 교란과 무관한 apoptosis 유발에 의한 것임을 sub-G1기 세포의 빈도 증가 및 apoptotic body 형성의 증가 등으로 확인하였다. 또한 MEGF 처리에 의한 백혈병세포의 증식억제 및 apoptosis 유발은 p53 비의존적인 p21의 발현 증가 및 Fas/FasL system의 발현 증가와 연관성이 있음을 알 수 있었다. 이상의 결과들은 인체 암세포, 특히 백혈병세포에서 MEGF의 항암작용을 이해하는데 중요한 자료가 될 것이고 나아가 MEGF 내 함유된 생리활성 물질의 분리 및 항암적용 연구를 위한 중요한 기초 자료로 활용될 것이다.

• Molecules and Cells
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• 제26권1호
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• pp.93-99
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• 2008

Transcriptional silencing is regulated by promoter methylation and histone modifications such as methylation and acetylation. We constructed a Schizosaccaromyces pombe reporter strain, KCT120a, to identify modifiers of transcriptional silencing, by inserting the $ura4^+$ gene into a heterochromatic telomere region. Two compounds inhibited the activity of histone deacetylases, induced acetylation of histone H3 and caused apoptotic cell death in HeLa cells. Expression of gelsolin and $p21^{waf1/cip1}$ also increased, as it does in response to HDAC inhibitors such as TSA. Therefore, these compounds appear to be potent inhibitors of HDACs, and hence potential anti-cancer drugs. Our observations suggest that a yeast cell-based assay system for transcriptional silencing may be useful for identifying histone deacetylase inhibitors and other agents affecting chromatin remodeling.

• BMB Reports
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• 제37권2호
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• pp.192-198
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• 2004

The hepatitis C virus (HCV) core protein is believed to be one of viral proteins that are capable of preventing virus-infected cell death upon various stimuli. But, the effect of the HCV core protein on apoptosis that is induced by various stimuli is contradictory. We examined the possibility that the HCV core protein affects the ceramide-induced cell death in cells expressing the HCV core protein through the sphingomyelin pathway. Cell death that is induced by $C^2$-ceramide and bacterial sphingomyelinase was analyzed in 293 cells that constitutively expressed the HCV core protein and compared with 293 cells that were stably transfected only with the expression vector. The HCV core protein inhibited the cell death that was induced by these reagents. The protective effects of the HCV core protein on ceramide-induced cell death were reflected by the reduced expression of $p21^{WAF1/Cip1/Sid1}$ and the sustained expression of the Bcl-2 protein in the HCV core-expressing cells with respect to the vector-transfected cells. These results suggest that the HCV core protein in 293 cells plays a role in the modulation of the apoptotic response that is induced by ceramide. Also, the ability of the HCV core protein to suppress apoptosis might have important implications in understanding the pathogenesis of the HCV infection.

• Journal of Microbiology and Biotechnology
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• 제24권12호
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• pp.1654-1663
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• 2014

To examine the effect of tumor suppressor protein p53 on the antitumor activity of 2-methoxyestradiol (2-MeO-$E_2$), 2-MeO-$E_2$-induced cell cycle changes and apoptotic events were compared between the human colon carcinoma cell lines HCT116 ($p53^{+/+}$) and HCT116 ($p53^{-/-}$). When both cell types were exposed to 2-MeO-$E_2$, a reduction in the cell viability and an enhancement in the proportions of $G_2/M$ cells and apoptotic sub-$G_1$ cells commonly occurred dose-dependently. These 2-MeO-$E_2$-induced cellular changes, except for $G_2/M$ arrest, appeared to be more apparent in the presence of p53. Immunofluorescence microscopic analysis using anti-${\alpha}$-tubulin and anti-lamin B2 antibodies revealed that after 2-MeO-$E_2$ treatment, impaired mitotic spindle network and prometaphase arrest occurred similarly in both cell types. Following 2-MeO-$E_2$ treatment, only HCT116 ($p53^{+/+}$) cells exhibited an enhancement in the levels of p53, p-p53 (Ser-15), $p21^{WAF1/CIP1}$, and Bax; however, the Bak level remained relatively constant in both cell types, and the Bcl-2 level decreased only in HCT116 ($p53^{+/+}$) cells. Additionally, mitochondrial apoptotic events, including the activation of Bak and Bax, loss of ${\Delta}{\psi}m$, activation of caspase-9 and -3, and cleavage of lamin A/C, were more dominantly induced in the presence of p53. The Bak-specific and Bax-specific siRNA approaches confirmed the necessity of both Bak and Bax activations for the 2-MeO-$E_2$-induced apoptosis in HCT116 cells. These results show that among 2-MeO-$E_2$-induced apoptotic events, including prometaphase arrest, up-regulation of Bax level, down-regulation of Bcl-2 level, activation of both Bak and Bax, and mitochondria-dependent caspase activation, the modulation of Bax and Bcl-2 levels is the target of the pro-apoptotic action of p53.

• Tuberculosis and Respiratory Diseases
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• 제57권5호
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• pp.449-460
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• 2004

연구배경 : PS-341은 최근에 개발된 강력하고 특이적인 proteasome 억제제로서, 일부 암환자에 투여하여 좋은 성적이 보고되고 있다. Proteasome 억제제의 항암효과는 아포프토시스 유발 물질, 즉 p53, $p21^{WAF/CIP1}$, $p27^{KIP1}$, NF-${\kappa}B$, Bax, Bcl-2 등의 발현 증가와 관련이 있는 것으로 생각되고 있다. JNK와 GSK-$3{\beta}$도 아포프토시스에 관여하는 것으로 잘 알려져 있지만, PS-341에 의한 아포프토시스에서의 역할은 규명되지 못한 상태이다. 본 연구에서는 폐암세포주에서 PS-341에 의한 아포프토시스에서 JNK와 GSK-$3{\beta}$의 역할을 규명하고자 하였다. 방 법 : NCI-H157과 A549 폐암세포주를 실험에 사용하였다. 세포생존능은 MTT 방법으로 평가하였고, 아포프토시스는 PARP의 분해로 평가하였다. JNK의 활성도는 in vitro immuno complex kinase 방법과 내인성 c-Jun의 인산화로 측정하였다. 각종 단백의 발현은 Western 분석으로 평가하였다. JNK1과 GSK-$3{\beta}$의 과발현은 각각 plasmid vector와 adenovirus vector를 이용하였다. 결 과 : PS-341 처치로 아포프토시스에 의한 세포생존율의 감소가 관찰되었다. PS-341 처치로 JNK가 활성화되었고, c-Jun의 발현이 유도되었다. Dominant negative JNK1의 과발현 또는 SP600125 전치치로 JNK의 활성화를 차단하면 PS-341에 의한 아포프토시스가 억제되었다. PS-341 처리로 JNK 활성화에 의존적으로 caspase 3의 활성화가 유도되었다. Caspase 활성화의 차단으로도 PS-341에 의한 아포프토시스가 억제되었다. PS-341에 의해 Akt가 활성화되었고, Akt 활성화의 차단으로 PS-341에 의한 아포프토시스가 심화되었다. PS-341에 의한 Akt 활성화로 GSK-$3{\beta}$가 불활성화되었다. Constitutively active GSK-$3{\beta}$의 과발현으로 PS-341에 의한 아포프토시스가 심화되었고, dominant negative GSK-$3{\beta}$의 과발현으로 PS-341에 의한 아포프토시스가 감소되었다. Lithium chloride 전처치와 dominant negative GSK-$3{\beta}$의 과발현으로 PS-341에 의한 JNK의 활성화와 c-Jun의 발현 증가가 억제되었다. 결 론 : 폐암세포주에서 PS-341에 의한 아포프토시스는 JNK/caspase 경로가 관여하며, 이는 PI3K/Akt 경로를 통한 GSK-$3{\beta}$의 불활성화에 의해 억제되는 것으로 판단된다. 따라서 PS-341의 항암효과를 최대화하기 위해서는 PI3K/Akt 경로를 통한 GSK-$3{\beta}$의 불활성화를 차단하는 치료법이 병행되어야 할 것으로 판단된다.

• 대한본초학회지
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• 제31권5호
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• pp.71-78
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• 2016

Objectives : Diabetic nephropathy is one of the most common chronic complications of diabetes and a leading cause of end-stage renal failure in the world. Mesangial cell proliferation is known as the major pathologic features such as glomerulosclerosis and renal fibrosis. Wiryeongtang (WRT) is a well-known traditional herbal formula as therapeutic agents for chronic edema and dysuresia of renal homeostasis. In the present study, we investigated whether WRT inhibits high glucose (HG)-induced renal dysfunction by TGF-β/Smads signal regulation in cultured mesangial cells.Methods : Inhibitory effect of WRT (10-50 ㎍/ml) on HG-stimulated mesangial cells proliferation and dysfunction were evaluated by [³H]-thymidine incorporation, Western blot, and RT-qPCR.Results : WRT significantly decreased HG-accelerated thymidine incorporation in human renal mesangial cell in a dose-dependent levels. WRT induced down-regulation of cyclins/CDKs and up-regulation of CDK inhibitor, p21waf1/cip1 and p27kip1 expression. In addition, HG enhanced expression of dysfunction biomarker such as collagen IV and CTGF, which was markedly attenuated by WRT. WRT decreased TGF-β1 and Smad-2/Smad-4 expression, whereas increased Smad-7 expression under HG. Furthermore, WRT inhibited HG-induced inflammatory factors level such as ICAM-1 and MCP-1 as well as NF-κB p65 nuclear translocation and intracellular ROS production.Conclusions : These results suggested that WRT may alleviate mesangial proliferation and inflammation possibly involved in renal fibrotic process, further diabetic nephropathy through disturbing TGF-β1/Smad signaling and NF-κB/ROS pathway. Thus, WRT might prove to be effective in the treatment of renal dysfunction leading to diabetic nephropathy.

• 한국해양바이오학회지
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• 제1권2호
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• pp.63-70
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• 2006

본 연구에서는 U937 인체 백혈병 세포의 증식에 미치는 PTX-2의 영향을 조사한 결과, PTX-2의 처리에 따라 U937 세포는 처리 농도 및 처리 시간 의존적으로 심한 형태적 변형과 함께 증식이 억제되었다. 이러한 PTX-2 처리에 의한 U937 세포의 증식억제는 apoptosis 유발과 관련이 있었으며, 이를 DAPI staining에 의한 apoptotic body 형성, flow cytometry를 이용한 sub-G1 세포 빈도의 정량적 분석을 통하여 확인하였다. 이러한 PTX-2 처리에 의한 U937 세포의 apoptosis 유발은 Bcl-2 family에 속하는 anti-apoptotic 인자인 Bcl-$X_L$의 발현 감소 및 IAPs family에 속하는 유전자들의 선택적 발현 감소와 연관성이 있음을 알 수 있었다. 이상의 결과들은 인체 암세포에서 PTX-2의 항암작용을 이해하는데 중요한 자료가 될 것이고 나아가 PTX-2을 포함한 그와 유사한 항암제 후보물질들의 연구에 있어서 기초 자료로서 사용될 수 있을 것으로 생각된다.

• Toxicological Research
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• 제23권4호
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• pp.321-330
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• 2007

Garlic (Allium sativum L.) with the food supplement material and medicine was used traditionally in Asia and Europe. Epidemiological studies revealed that the intake of garlic reduced incidences of various cancer including digestive system. The present study was designed to investigate the effect of garlic ethanol extract on the development of colonic aberrant crypt foci (ACF) induced by 1,2-dimethylhydrazine (DMH) in male F344 rats. Five-week-old rats were given four times for two weeks to subcutaneous injections by DMH (30 mg/kg body weight) to induce ACF. The animals were divided into groups that fed diet containing garlic ethanol extract at five different doses (0.1, 0.2, 0.5, 2, 5%), respectively, animals were evaluated for the total number of ACF and total aberrant crypts (AC) per colon detected from methylene blue-stained rat colon. ACF were formed in animals in DMH-treated group. The feeding suppressed potently the appearance ACF in the colon of rats. Especially, fed diet containing garlic ethanol extract at intermediate dose (0.5%) significantly reduced the number of ACF and AC per colon (p < 0.05). Garlic ethanol extract inhibited DMH-induced overexpression of Activator Protein-1 (AP-1) and ${\beta}-catenin$ genes related to cell proliferation that also upregulated the expression of p21Waf1/Cip1 mRNA, a cell cycle-regulating gene. These results suggested that garlic ethanol extract may inhibit ACF formation, ${\beta}-catenin$ gene as the early preneoplastic marker of malignant potential in the process of colon carcinogenesis.

• 대한한방내과학회지
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• 제29권1호
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• pp.130-148
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• 2008

Objective : This study was designed to investigate the effect of the water extract of Gamisamgibopae-tang(GMSGBPT), an oriental herbal formulation, on the growth of NCI-H460 and A549 human non-small-cell lung cancer cell lines. Methods : Cytotoxicity and cell morphology were evaluated by MTT assay and inverted microscope, respectively. Apoptosis was detected using agarose gel electrophoresis and flow cytometer. The expression levels of mRNAs and proteins of target genes were determined by RT-PCR and western blot analyses, respectively Result and Conclusion : We found that exposure of A549 cells to GMSGBPT resulted in the growth inhibition in a dose-dependent manner as measured by MTT assay, but GMSGBPTdid not affect the growth of NCI-H460 cells. The anti-proliferative effect of GMSGBPT treatment in A549 cells was associated with morphological changes, formation of apoptotic bodies and DNA fragmentation, and flow cytometry analysis confirmed that GMSGBPT treatment increased the populations of apoptotic-sub G1 phase. Growth inhibition and apoptotic cell death by GMSGBPT were connected with a up-regulation of cyclin-dependent kinase inhibitor p21 (WAF1/CIP1) mRNA and protein in a tumor suppressor p53-independent fashion. However GMSGBPT treatment did not affect other growth regulation-related genes such as early growth response-1 (Egr-1), nonsteroidal anti-inflammatory drug (NSAID)-activated gene-1 (NAG-1), inducible nitric oxide synthase (iNOS), cyclooxygenases (COXs), telomere-regulatory factors in A549 orNCI-H460 cells. Taken together, these findings partially provide novel insights into the possible molecular mechanism of the anti-cancer activity of GMSGBPT.