http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Yun, JiEun,Lee, Dong Gun Elsevier 2017 Biochimica et biophysica acta, General subjects Vol.1861 No.3
<P><B>Abstract</B></P> <P><B>Background</B></P> <P>Chlorogenic acid (CRA) is an abundant phenolic compound in the human diet. CRA has a potent antifungal effect, inducing cell death in <I>Candida albicans</I>. However, there are no further studies to investigate the antifungal mechanism of CRA, associated with ion channels.</P> <P><B>Methods</B></P> <P>To evaluate the inhibitory effects on CRA-induced cell death, <I>C. albicans</I> cells were pretreated with potassium and chloride channel blockers, separately. Flow cytometry was carried out to detect several hallmarks of apoptosis, such as cell cycle arrest, caspase activation, and DNA fragmentation, after staining of the cells with SYTOX green, FITC-VAD-FMK, and TUNEL.</P> <P><B>Results</B></P> <P>CRA caused excessive potassium efflux, and an apoptotic volume decrease (AVD) was observed. This change, in turn, induced cytosolic calcium uptake and cell cycle arrest in <I>C. albicans</I>. Moreover, CRA induced caspase activation and DNA fragmentation, which are considered apoptotic markers. In contrast, the potassium efflux and proapoptotic changes were inhibited when potassium channels were blocked, whereas there was no inhibitory effect when chloride channels were blocked.</P> <P><B>Conclusions</B></P> <P>CRA induces potassium efflux, leading to AVD and G2/M cell cycle arrest in <I>C. albicans</I>. Therefore, potassium efflux via potassium channels regulates the CRA-induced apoptosis, stimulating several apoptotic processes.</P> <P><B>General significance</B></P> <P>This study improves the understanding of the antifungal mechanism of CRA and its association with ion homeostasis, thereby pointing to a role of potassium channels in CRA-induced apoptosis.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Chlorogenic acid (CRA) induces apoptosis in <I>Candida albicans</I>. </LI> <LI> CRA induces potassium efflux leading to apoptotic volume decrease. </LI> <LI> Block of the potassium channels inhibits the apoptotic effect of CRA. </LI> <LI> Potassium channels play a key role in regulation of the CRA-induced apoptosis. </LI> </UL> </P>
Effect of isoquercitrin on membrane dynamics and apoptosis-like death in <i>Escherichia coli</i>
Yun, JiEun,Woo, Eun-Rhan,Lee, Dong Gun Elsevier 2018 Biochimica et biophysica acta, Biomembranes Vol.1860 No.2
<P><B>Abstract</B></P> <P>Minimum inhibitory concentration (MIC) is defined as the lowest concentration of a compound that completely inhibits microbial growth. Antibacterial mechanisms of compounds have been investigated at their sub-MICs as well as at their MIC. In this study, the effects of sub-MIC and MIC of isoquercitrin on <I>Escherichia coli</I> were investigated. The antibacterial effect of isoquercitrin was tested using the microdilution method. Sub-MICs of isoquercitrin induced the production of reactive oxygen species and depletion of glutathione. The oxidative effects induced by sub-MICs of isoquercitrin could be prolonged, finally resulting in apoptosis-like death. DNA fragmentation and phosphatidylserine externalization, which are regarded as the hallmarks of apoptosis, were evaluated using the TUNEL assay and Annexin V staining, respectively. Furthermore, isoquercitrin induced the peroxidation of membrane lipids and inner membrane permeabilization at both its sub-MIC and MIC. This suggested membrane damage in response to lipid oxidation. The uptake of membrane impermeable dyes, propidium iodide and calcein, demonstrated that isoquercitrin damaged the cell membrane at concentrations higher than its MIC. Thus, isoquercitrin induced apoptosis-like death and dysregulation of cell membrane dynamics.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Isoquercitrin induces the cell death of <I>Escherichia coli</I> cells. </LI> <LI> Isoquercitrin has two antibacterial mechanisms: Apoptosis-like death and Membrane. </LI> <LI> Isoquercitrin has the oxidative effect on <I>E. coli</I> cells. </LI> <LI> Isoquercitrin induces apoptosis-like death at sub-MIC levels. </LI> <LI> Isoquercitrin induces the membrane dysfunction at MIC levels. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
Yun, JiEun,Hwang, Jae-Sam,Lee, Dong Gun Portland Press Ltd. 2017 Biochemical journal Vol. No.
<P>The cockroach, which is a household insect, is an established model organism in research. Periplanetasin-2, derived from the American cockroach <I>Periplaneta americana</I>, exerted potent antifungal effect against pathogenic fungi without causing hemolysis. Periplanetasin-2 induced oxidative stress by generation of reactive oxygen species (ROS) and lipid peroxidation. Periplanetasin-2 also caused apoptosis by exposure of phosphatidylserine and fragmentation of DNA, exerted in a concentration-dependent manner. Hence, we investigated the mitochondrial apoptotic mechanism of periplanetasin-2 in <I>Candida albicans</I>. After treatment with periplanetasin-2, we observed mitochondrial depolarization and calcium accumulation. Moreover, we observed a decrease in cytosolic glutathione, and an increase in mitochondrial glutathione, indicating that periplanetasin-2 induced oxidative stress and high ROS production in the mitochondria. Because of this mitochondrial dysfunction, cytochrome <I>c</I> was released from the mitochondria into the cytosol, and caspase was activated in a time-dependent manner. In summary, the antifungal peptide periplanetasin-2 activates apoptotic signals in the mitochondria by induction of oxidative stress.</P>
Yun, Jieun,Han, Sang-Bae,Kim, Hong Jun,Go, Se-il,Lee, Won Sup,Bae, Woo Kyun,Cho, Sang-Hee,Song, Eun-Kee,Lee, Ok-Jun,Kim, Hee Kyung,Yang, Yaewon,Kwon, Jihyun,Chae, Hee Bok,Lee, Ki Hyeong,Han, Hye Sook The Korean Gastric Cancer Association 2019 Journal of gastric cancer Vol.19 No.3
Purpose: Peritoneal carcinomatosis in gastric cancer (GC) patients results in extremely poor prognosis. Malignant ascites samples are the most appropriate biological material to use to evaluate biomarkers for peritoneal carcinomatosis. This study identified exosomal MicroRNAs (miRNAs) differently expressed between benign liver cirrhosis-associated ascites (LC-ascites) and malignant gastric cancer-associated ascites (GC-ascites), and validated their role as diagnostic biomarkers for GC-ascites. Materials and Methods: Total RNA was extracted from exosomes isolated from 165 ascites samples (73 LC-ascites and 92 GC-ascites). Initially, microarrays were used to screen the expression levels of 2,006 miRNAs in the discovery cohort (n=22). Subsequently, quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) analyses were performed to validate the expression levels of selected exosomal miRNAs in the training (n=70) and validation (n=73) cohorts. Furthermore, carcinoembryonic antigen (CEA) levels were determined in ascites samples. Results: The miR-574-3p, miR-181b-5p, miR-4481, and miR-181d were significantly downregulated in the GC-ascites samples compared to the LC-ascites samples, and miR-181b-5p showed the best diagnostic performance for GC-ascites (area under the curve [AUC]=0.798 and 0.846 for the training and validation cohorts, respectively). The diagnostic performance of CEA for GC-ascites was improved by the combined analysis of miR-181b-5p and CEA (AUC=0.981 and 0.946 for the training and validation cohorts, respectively). Conclusions: We identified exosomal miRNAs capable of distinguishing between non-malignant and GC-ascites, showing that the combined use of miR-181b-5p and CEA could improve diagnosis.
Notch1 발현이 NCI-H460 폐암원형체의 침윤성 및 항암제 내성 발현에 미치는 기전 분석
윤지은(Jieun Yun) 대한약학회 2018 약학회지 Vol.62 No.6
서 론(Introduction) 실험방법(Experimental Methods) 결과 및 고찰(Results and Discussion) 결 론(Conclusion)