• Molecules and Cells
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• 제19권3호
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• pp.303-309
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• 2005

The end of eukaryotic genomic DNA is capped by a specialized structure called as "telomere" which consists of the repetitive array of nucleotide sequence, TTAGGG, in humans and mice, and a variety of binding proteins. Telomerase is a ribonucleoprotein (RNP) complex responsible for the elongation of telomeres to maintain the genomic integrity, and is composed of telomerase reverse transcriptase (TERT), telomerase RNA component (TERC), and their associated factors regulating the catalytic activity of telomerase. Although it is now apparent that telomerase protects cells from apoptosis via the maintenance of genomic integrity by stabilizing telomeres, our understanding for the physiological role of telomerase is yet far from completion, and emerging evidence suggests that telomerase has additional extratelomeric roles in mediating cell survival and anti-apoptotic functions against various cytotoxic stresses. Here we summarize and discuss how telomerase and telomeres are involved in mediating cellular protection against apoptosis.

• BMB Reports
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• 제56권2호
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• pp.126-131
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• 2023

The abnormal accumulation and aggregation of the misfolded α-synuclein protein is the neuropathological hallmark of all α-synucleinopathies, including Parkinson's disease. The secreted proteins known as netrins (netrin-1, netrin-3, and netrin-4) are related to laminin and have a role in the molecular pathway for axon guidance and cell survival. Interestingly, only netrin-1 is significantly expressed in the substantia nigra (SN) of healthy adult brains and its expression inversely correlates with that of α-synuclein, which prompted us to look into the role of α-synuclein and netrin-1 molecular interaction in the future of dopaminergic neurons. Here, we showed that netrin-1 and α-synuclein directly interacted in pre-formed fibrils (PFFs) generation test, real time binding assay, and co-immunoprecipitation with neurotoxin treated cell lysates. Netrin-1 deficiency appeared to activate the dopaminergic neuronal cell death signal pathway via α-synuclein aggregation and hyperphosphorylation of α-synuclein S129. Taken together, netrin-1 can be a promising therapeutic molecule in Parkinson's disease.

• Imaging Science in Dentistry
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• 제33권3호
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• pp.143-149
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• 2003

Purpose: To investigate the radiosensitivity of the normal human oral keratinocytes (NHOK), and the effect of irradiation on cell cycle and protein expression. Materials and Methods: To evaluate the radiosensitivity of NHOK, the number of colonies and cells were counted after irradiation and the SF2 (survival fraction at 2Gy) value, and the cell survival curve fitted on a linear-quadratic model were obtained. LDH analysis was carried out to evaluate the necrosis of NHOK at 1, 2, 3, and 4 days after 2, 10, and 20 Gy irradiation. Cell cycle arrest and the induction of apoptosis were analyzed using flow cytometry at 1, 2, 3, and 4 days after 2, 10, and 200y irradiation. Finally, proteins related cell cycle arrest and apoptosis were analysed by Western blot. Results: The number of survived cell was significantly decreased in a dose-dependent manner. The cell survival curve showed SF2, α, and β values to be 0.568, 0.209, and 0.020 respectively. At 200y irradiated cells showed higher optical density than the control group. After irradiation, apoptosis was not observed but G2 arrest was observed in the NHOK cells. 1 day after 10 Gy irradiation, the expression of p53 remained unchanged, the p2l/sup WAF1/Cipl/ increased and the mdm2 decreased. The expression of bax, bcl-2, cyclin B1, and cyclin D remained unchanged. Conclusion: These results indicate that NHOK responds to irradiation by G2 arrest, which is possibly mediated by the expression of p21/sup WAFl/Cipl/, and that cell necrosis occurs by high dose irradiation.

• 환경생물
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• 제33권1호
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• pp.7-18
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• 2015

본 연구는 시멘트 노출에 따른 어류 조직의 형태 생리적 변화를 분석하여 용해된 시멘트 분말이 어류에 미치는 영향을 조사하고자 하였다. 용해된 시멘트 분말에 노출된 아가미는 일차새변의 두께가 두꺼워지고, 염세포와 점액세포도 두드러지게 활성이 증가되고 있으며, 이차새변의 새엽에서는 상피세포의 증식과 박리 및 곤봉화 현상도 관찰되었다. 신장 조직에서는 보우만 주머니 공간이 넓게 관찰되었고, 표피 조직은 표피층의 두께가 감소하며 진피층의 배열이 불규칙해지는 것으로 관찰되었다. 항산화효소와 LDH의 활성은 조직 및 노출 기간에 따라 활성에 차이가 있는 것으로 나타났다. 표피 조직에서 용해된 시멘트 분말에 의해 발현이 증가되는 단백질은 해당과정과 에너지 대사과정에 관여하는 단백질로 확인되었고 발현이 저하된 단백질들은 근수축에 관여하는 근섬유 구성 단백질로 조사되었다. 이러한 결과로 보아 용해된 시멘트 분말은 붕어 조직의 형태적 변형과 생리적 기능의 약화를 초래하여 어류의 생존에 커다란 위협이 될 요인으로 작용할 수 있을 것으로 사료된다.

• Tuberculosis and Respiratory Diseases
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• 제68권1호
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• pp.22-28
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• 2010

Background: Vascular endothelial growth factor (VEGF) is a potent mediator of angiogenesis. VEGF production is regulated by HIF-$1{\alpha}$ and EGFR. This study examined the relationship between the clinicopathological factors and VEGF, HIF-$1{\alpha}$ and EGFR protein overexpression, and evaluated their prognostic value in patients with a surgically resected non-small cell lung cancer (NSCLC). Methods: Patients who underwent a surgical resection at Kangnam St. Mary's hospital were reviewed retrospectively. The core biopsy samples from 54 patients with NSCLC were assembled on a tissue microarray (TMA), and immunohistochemical staining for the VEGF, HIF-$1{\alpha}$ and EGFR proteins was performed. The overexpression of these proteins was evaluated in relation to age, gender, histology and staging by univariate analysis. The clinicopathological prognostic factors were analyzed. Results: Multivariate analysis performed by Cox regression (odds ratio 2.8, 95% CI 1.0~8.2, p=0.046) revealed HIF-$1{\alpha}$ overexpression to be an unfavorable factor. There was no correlation between the overexpression of these proteins and the clinicopathological factors. VEGF showed a positive relationship with EGFR, but there was no statistical significance [$p(x^2)=0.06$]. Conclusion: HIF-$1{\alpha}$ overexpression predicts shorter survival in patients with a surgically resected NSCLC. Therefore, HIF-$1{\alpha}$ may be a poor prognostic factor in NSCLC.

• 미생물학회지
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• 제37권3호
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• pp.221-227
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• 2001

열충격 단백질(heat shock protein: HSP)은 변성된 단백질의 응집을 방지하여 가혹한환경에서 병원균의 생존을 증가시킨다. 세균에 알코을 stress를 가하면 다량의 DnaK와 GronEL이 유도되지만 폐렴구균에서는 DnaK와 GroEL이 전혀 유도되지 않는 대신 알코올탈수소효소(alcohol dehydrogenase : ADH)가 유도되었다. 이런 특성은 폐렴구균 ADH가 HSP처럼 chaperone 기능을 수행라고 있을 가능성을 제시하고 있으므로 본 연구에서는 일차적으로 ADH 유전자를 확인하고 ADH 의 면역특성 및 세포내 분포를 측정하였다. 폐렴구균 ADH는 이질아메바 ADH2 및 대장균 ADH 와 높은 유사성을 나타냈으며 883 개의 아미노산으로 구성된 등전점 6.09의 단백질로 추정된다. 그러나 폐렴구균 ADH와 유사성이 높은 대장균, 유산균 및 황색포도상구균의 용해액을 폐렴구균 ADH 항체와 immunoblot을 실시하였을 때 전혀 반응하지 않았다. 또한 세포질, membrane, periplasm에 있는 단백질 분획 및 폐렴구균 배양 상등액을 ADH 항체와 immune blot을 실시하였을 때 ADH 는 열충격에 관계없이 세포 밖으로 분비되는 단백질임을 확인하였다. 이런 결과는 폐렴구균 ADH가 진단용항원 및 백신으로 개발될 수 있는 가능성을 제시하고 있다.

• Journal of Microbiology and Biotechnology
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• 제30권2호
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• pp.187-195
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• 2020

To understand the molecular mechanism involved in the survivability of cold-tolerant lactic acid bacteria was of great significance in food processing, since these bacteria play a key role in a variety of low-temperature fermented foods. In this study, the cold-stress response of probiotic Lactobacillus plantarum K25 isolated from Tibetan kefir grains was analyzed by iTRAQ proteomic method. By comparing differentially expressed (DE) protein profiles of the strain incubated at 10℃ and 37℃, 506 DE proteins were identified. The DE proteins involved in carbohydrate, amino acid and fatty acid biosynthesis and metabolism were significantly down-regulated, leading to a specific energy conservation survival mode. The DE proteins related to DNA repair, transcription and translation were up-regulated, implicating change of gene expression and more protein biosynthesis needed in response to cold stress. In addition, two-component system, quorum sensing and ABC (ATP-binding cassette) transporters also participated in cell cold-adaptation process. These findings provide novel insight into the cold-resistance mechanism in L. plantarum with potential application in low temperature fermented or preserved foods.

• Asian Pacific Journal of Cancer Prevention
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• 제17권2호
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• pp.581-590
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• 2016

Resistance to anoikis, a cell-detachment induced apoptosis, is one of the malignant phenotypes which support tumor metastasis. Molecular mechanisms underlying the establishment of this phenotype require further investigation. This study aimed at exploring protein expression profiles associated with anoikis resistance of a metastatic breast cancer cell. Cell survival of suspension cultures of non-metastatic MCF-7 and metastatic MDA-MB-231 cells were compared with their adherent cultures. Trypan blue exclusion assays demonstrated a significantly higher percentage of viable cells in MDA-MB-231 than MCF-7 cell cultures, consistent with analysis of annexin V-7-AAD stained cells indicating that MDA-MB-231 possess anti-apoptotic ability 1.7 fold higher than MCF-7 cells. GeLC-MS/MS analysis of protein lysates of MDA-MB-231 and MCF-7 cells grown under both culture conditions identified 925 proteins which are differentially expressed, 54 of which were expressed only in suspended and adherent MDA-MB-231 but not in MCF-7 cells. These proteins have been implicated in various cellular processes, including DNA replication and repair, transcription, translation, protein modification, cytoskeleton, transport and cell signaling. Analysis based on the STITCH database predicted the interaction of phospholipases, PLC and PLD, and 14-3-3 beta/alpha, YWHAB, with the intrinsic and extrinsic apoptotic signaling network, suggesting putative roles in controlling anti-anoikis ability. MDA-MB-231 cells grown in the presence of inhibitors of phospholipase C, U73122, and phospholipase D, FIPI, demonstrated reduced ability to survive in suspension culture, indicating functional roles of PLC and PLD in the process of anti-anoikis. Our study identified intracellular mediators potentially associated with establishment of anoikis resistance of metastatic cells. These proteins require further clarification as prognostic and therapeutic targets for advanced breast cancer.

• The Korean Journal of Physiology and Pharmacology
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• 제17권1호
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• pp.43-50
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• 2013

Palmitic acid (PAM), one of the most common saturated fatty acid (SFA) in animals and plants, has been shown to induce apoptosis in exocrine pancreatic AR42J cells. In this study, we investigated cellular mechanisms underlying protective effects of oleic acid (OLA) against the lipotoxic actions of PAM in AR42J cells. Exposure of cells to long-chain SFA induced apoptotic cell death determined by MTT cell viability assay and Hoechst staining. Co-treatment of OLA with PAM markedly protected cells against PAM-induced apoptosis. OLA significantly attenuated the PAM-induced increase in the levels of pro-apoptotic Bak protein, cleaved forms of apoptotic proteins (caspase-3, PARP). On the contrary, OLA restored the decreased levels of anti-apoptotic Bcl-2 family proteins (Bcl-2, Bcl-xL, and Mcl-1) in PAM-treated cells. OLA also induced up-regulation of the mRNA expression of Dgat2 and Cpt1 genes which are involved in triacylglycerol (TAG) synthesis and mitochondrial ${\beta}$-oxidation, respectively. Intracellular TAG accumulation was increased by OLA supplementation in accordance with enhanced expression of Dgat2 gene. These results indicate that restoration of anti-apoptotic/pro-apop-totic protein balance from apoptosis toward cell survival is involved in the cytoprotective effects of OLA against PAM-induced apoptosis in pancreatic AR42J cells. In addition, OLA-induced increase in TAG accumulation and up-regulation of Dgat2 and Cpt1 gene expressions may be possibly associated in part with the ability of OLA to protect cells from deleterious actions of PAM.

• Asian Pacific Journal of Cancer Prevention
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• 제17권8호
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• pp.3929-3937
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• 2016

Gastric cancer (GC) is a major health problem worldwide and is one of the ten most commonly diagnosed cancers in Jordan. GC is usually diagnosed at late aggressive stages in which treatment options are limited. Recently, heat shock proteins (HSPs) were found to be overexpressed in a wide range of malignancies have been considered as promising candidate biomarkers for GC. The aim of this study was to investigate pathogenic roles of a panel of cytosolic HSPs including HSP90, HSP70, HSP60 and HSP27 in GC. Immunohistochemistry was used to assess the level of expression of these proteins in archived tumor samples (N=87) representing various pathological characteristics of GC. HSP90, HSP60 and HSP27 were expressed abundantly in gastric tumors. On the other hand, HSP70 was reduced significantly and also found to be associated with Helicobacter pylori infection in tissues collected from GC patients. Furthermore, HSP27 was found to be associated with the level of differentiation. Our findings indicate a role of HSP70 as a potential prognostic biomarker, patients harboring positive HSP70 expression displaying worse disease free survival than those with negative HSP70 expression. Differential expression of HSPs may play crucial roles in the initiation and progression of GC, and could be exploited as future therapeutic targets.