• Journal of Plant Biotechnology
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• v.33 no.1
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• pp.1-9
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• 2006

Peroxiredoxins (Prxs) are ubiquitously distributed and play important functions in diverse cellular signaling systems. The proteins are largely classified into three groups, such as typical 2-Cys Prx, atypical 2-Cys Prx, and 1-Cys Prx, that are distinguished by their catalytic mechanisms and number of Cys residues. From the three classes of Prxs, the typical 2-Cys Prx containing the two-conserved Cys residues at its N-terminus and C-terminus catalyzes $H_2O_2$ with the use of thioredoxin (Trx) as an electron donor. During the catalytic cycle, the N-terminal Cys residue undergoes a peroxide-dependent oxidation to sulfenic acid, which can be further oxidized to sulfinic acid at the presence of high concentrations of $H_2O_2$ and a Trx system containing Trx, Trx reductase, and NADPH. The sulfinic acid form of 2-Cys Prx is reduced by the action of sulfiredoxin which requires ATP as an energy source. Under the strong oxidative or heat shock stress conditions, 2-Cys Prx in eukaryotes rapidly switches its protein structure from low-molecular-weight species to high-molecular-weight protein structures. In accordance with its structural changes, the protein concomitantly triggers functional switching from a peroxidase to a molecular chaperone, which can protect its substrate denaturation from external stress. In addition to its N-terminal active site, the C-terminal domain including 'YF-motif' of 2-Cys Prx plays a critical role in the structural changes. Therefore, the C-terminal truncated 2-Cys Prxs are not able to regulate their protein structures and highly resistant to $H_2O_2$-dependent hyperoxidation, suggesting that the reaction is guided by the peroxidatic Cys residue. Based on the results, it may be concluded that the peroxidatic Cys of 2-Cys Prx acts as an '$H_2O_2$-sensor' in the cells. The oxidative stress-dependent regulation of 2-Cys Prx provides a means of defense systems in cells to adapt stress conditions by activating intracellular defense signaling pathways. Particularly, 2-Cys Prxs in plants are localized in chloroplasts with a dynamic protein structure. The protein undergoes conformational changes again oxidative stress. Depending on a redox-potential of the chloroplasts, the plant 2-Cys Prx forms super-molecular weight protein structures, which attach to the thylakoid membranes in a reversible manner.

• Journal of Plant Biotechnology
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• v.33 no.1
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• pp.11-18
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• 2006

Salt stress is one of major environmental factors influencing plant growth and development. To identify salt tolerance determinants in higher plants, a large-scale screen was conducted with a bialaphos marker-based T-DNA insertional collection of Arabidopsis ecotype C24 mutants. One line for salt stress-sensitive mutant (referred to as ssm1) exhibited increased sensitivity to both ionic (NaCl) and nonionic (mannitol) osmotic stress in a root growth assay. This result suggests that ssm1 mutant is involved in ion homeostasis and osmotic compensation in plant. Molecular cloning of the genomic DNA flanking T-DNA insert of ssm1 mutant was achieved by mutant genomic DNA library screening. T-DNA insertion appeared in the first exon of an open reading frame on F3M18.7, which is the same as AtSYP61. SSM1 is SYP61/OSM1 that is a member of the SNARE superfamily of proteins required for vesicular/target membrane fusions and factor related to abiotic stress.

• The Journal of Korean Academy of Prosthodontics
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• v.49 no.3
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• pp.254-262
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• 2011

Purpose: This study aims to evaluate and prospect for current research trend and developmental perspectives via analyzing recent biomaterial coated-implants study. Materials and methods: To investigate each subject respectively, several biomaterials that are using for implant surface coating were set as 'keywords'. By these keywords, major research groups in each subject were chosen, and research trend of them was analyzed. Trend of In vivo studies that examined selected biomaterials were analyzed to evaluate commercial potential. Results: The collagen research accounted for 40% of total implant study, which was the highest, and fibronectin, BMPs (bone morphogenetic proteins) and RGD (Arg-Gly-Asp) peptides followed, which were ranked in descending order. Furthermore, figures of all four research subjects were also increased with time, especially a sharp increase in RGD research. According to the results of major research group, collagen that was combined with other organic and inorganic biomaterials was mostly examined, rather than using collagen only. Major research groups investigating BMPs mostly focused on rhBMP-2. In animal studies, collagen was used as resorbable membrane in guided bone regeneration (GBR) or drug carrier, while BMPs were used with bone graft materials or coating material for titanium implant surface. Conclusion: There is not consistency of results even in identical subjects research field. Many studies are ongoing to optimize combination between mechanical surface treatment and biomaterials such as extracellular matrix component and growth factors.

• Journal of Chest Surgery
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• v.38 no.1 s.246
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• pp.38-43
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• 2005

Matrix metalloproteinase-2 (MMP-2) is a class of proteolytic enzymes that digest collagen type IV and other components of the basement membrane. It plays a key role in the local invasion and the formation of distant metastases by various malignant tumors. The aim of this study was to evaluate the activity of MMP-2 and its significance as a prognostic marker in resected stage I non-small cell lung cancer (NSCLC). Material and Method: In this study we obtained fresh-frozen samples of tumor and non-tumor tissues from 34 patients with stage I NSCLC who underwent resection without preoperative radiotherapy or chemotherapy. After the extraction of total protein from tissue samples, MMP-2 activities were assessed by gelatin-substrate-zymography. The activities were divided into the higher or lower groups. Result: The MMP-2 activities were higher in tumor tissues than in non-tumor tissues. The MMP-2 activity of non-tumor tissues in recurrent group was higher than in non-recurrent group (p<0.01). Also the patients with higher MMP-2 activity of non-tumor tissues showed poor 5 year survival (p<0.01). Conclusion: This result indicates that the higher level of MMP-2 activity in the non-tumor tissue is associated with the recurrence and survival after the resection of stage I NSCLC. Therefore, MMP-2 activity in the non-tumor tissue could be used as a potential prognostic marker for the resected stage I-NSCLC.

• Tuberculosis and Respiratory Diseases
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• v.59 no.1
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• pp.30-38
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• 2005

Background : Arsenic trioxide ($As_2O_3$) has been used to treat acute promyelocytic leukemia, and it induces apoptosis in a variety of solid tumor cell lines including non-small cell lung cancer cells. However, nonsteroidal antiinflammatory drugs (NSAID) can enhance tumor response to chemotherapeutic drugs or radiation. It was previously demonstrated that a combination treatment with $As_2O_3$ and sulindac induces the apoptosis of NCI-H157 human lung carcinoma cells by activating the caspase cascade. This study aimed to determine if a combination treatment augmented its apoptotic potential through other pathways except for the activation of the caspase cascade. Material and Methods : The NCI-H157 cells were treated with $As_2O_3$, sulindac and antioxidants such as glutathione (GSH) and N-acetylcysteine (NAC). The cell viability was measured by a MTT assay, and the level of intracellular hydrogen peroxide ($H_2O_2$) generation was monitored fluorimetrically using a scopoletin-horse radish peroxidase (HRP) assay. Western blotting and mitochondrial membrane potential transition analysis were performed in order to define the mechanical basis of apoptosis. Results : The viability of the cells was decreased by a combination treatment of $As_2O_3$ and sulindac, and the cells were protected using antioxidants in a dose-dependent manner. The increased $H_2O_2$ generation by the combination treatment was inhibited by antioxidants. The combination treatment induced changes in the mitochondrial transmembrane potential as well as the expression of the Bcl-2 family proteins, and increased cytochrome c release into the cytosol. However, the antioxidants inhibited the effects of the combination treatment. Conclusion : Combination treatment with $As_2O_3$ and sulindac induces apoptosis in NCI-H157 human lung carcinoma cells via ROS generation with a mitochondrial dysfunction.

• Journal of Oral Medicine and Pain
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• v.38 no.3
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• pp.221-233
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• 2013

Bile acids are polar derivatives of cholesterol essential for the absorption of dietary lipids and regulate the transcription of genes that control cholesterol homeostasis. Recently it have been identified the synthetic chenodeoxycholic acid (CDCA) derivatives HS-1200 and cisplatin showed apoptisis-inducing activity on various cancer cells in vivo and in vitro. This study was undertaken to investigate the synergistic apoptotic effect of co-treatment with HS-1200 and cisplatin on human tongue squamous cell carcinoma cells (SCC25 cells). To investigate whether the co-treatment with HS-1200 and cisplatin compared to each single treatment efficiently reduces the viability of SCC25 cells, MTT assay was conducted. The induction and augmentation of apoptosis were confirmed by DNA electrophoresis, Hoechst staining and an analysis DNA hypoploidy. Westen blot analysis and immunofluorescent staining were also performed to evaluate the expression levels and the translocation of apoptosis-related proteins following this co-treatment. Furthermore, proteasome activity and mitochondrial membrane potential (MMP) change were also assayed. In this study, co-treatment with HS-1200 and cisplatin on SCC25 cells showed several lines of apoptotic manifestation such as nuclear condensations, DNA fragmentation, reduction of MMP and proteasome activity, the increase of Bax and the decrease of Bcl-2, decrease of DNA content, the release of cytochrome c into cytosol, translocation of AIF and DFF40 (CAD) onto nuclei, and activation of caspase-9, caspase-7, caspase-3, PARP and DFF45 (ICAD) whereas each single treated SCC25 cells did not show these patterns. Although the single treatment of $25{\mu}M$ HS-1200 and $4{\mu}g/ml$ cisplatin for 24 h did not induce apoptosis, the co-treatment of these reagents prominently induced apoptosis. Therefore our data provide the possibility that the combination therapy with HS-1200 and cisplatin could be considered as a novel therapeutic strategy for human squamous cell carcinoma.

• 한국환경농학회:학술대회논문집
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• 2009.07a
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• pp.273-282
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• 2009

The transmissible spongiform encephalopathies (TSEs) disease group are fatal neurodegenerative disorders affecting a wide range of hosts. The group includes kuru and Creutzfeldt-Jakob disease (CJD) in humans, scrapie in sheep and goats and Bovine spongiform encephalopathy (BSE) in cattle. The exact nature of the infectious agent involved in the transmission of these diseases remains controversial. However, a central event in their pathogenesis is the accumulation in infected tissues of an abnormal form of a host-encoded protein, the prion protein (PrP). Whereas the normal cellular protein is fully sensitive to protease ($PrP^{sen}$), the disease-associated prion protein ($PrP^d$) is only partly degraded ($PrP^{res}$), its amino-terminal end being removed. BSE was first reported in the mid-80s in the UK. Ten years later, a new form of human prion disease, variant CJD (vCJD) developed in the wake of the BSE epidemic, and there is now strong scientific evidence that vCJD was initiated by the exposure of humans to BSE-infected tissues, thus indicating a zoonotic disease. However, the ban on the feeding of animal-derived proteins to ruminants, and the apparent lack of vertical transmission of BSE, have led to a decline in the incidence of the disease within cattle herd and therefore, an assumed decreased risk for human contacting vCJD. The origin of the original case(s) of BSE still remains an enigma even though three hypotheses have been raised. Hypotheses are i) sheep- or goat-derived scrapie-infected tissues included in meat and bone meal fed to cattle, ii) a previously undetected sporadic or genetic bovine TSE contaminating cattle feed or iii) originating from a human TSE through animal feed contaminated with human remains. A host cellular membrane protein ($PrP^C$), which is abundant in central nervous system tissue, appear to be conformationally altered in the diseased host into a prion protein ($PrP^{Sc}$). This $PrP^{Sc}$ is detergent insoluble and partially protease-resistant ($PrP^{res}$). The term $PrP^{res}$ is normally used to describe the protein detected after protease treatment, in techniques such as Western immunoblotting, and enzyme-linked immunosorbant assay using fresh/frozen tissue. Immunohistochemistry may performed with formalin-fixed tissues. Also, clinical signs of the BSE are one of the major diagnostic indicators. Recently, atypical forms (known as H- and L-type) of BSE have appeared in several European countries, Japan, Canada and the United States. An unusual case was also reported in a miniature zebu. The atypical BSE fall into two groups based on the relative molecular mass (Mm) of the unglycosylated $PrP^{res}$ band relative to that of classical BSE, one of the higher Mm (H-type) and the other lower (L-type). Both types have been detected worldwide as rare cases in older animals, at a low prevalence consistent with the possibility of sporadic forms of prion diseases in cattle. This raises the unwelcome possibility that vCJD could increase in the human population. Now, active surveillance program against BSE is going on in Korea. In regional veterinary service lab, ELISA is applied to screen the BSE in slaughter and confirmatory tests by Western immunoblotting and immunohistochemisty are carried out if there are positive or suspect in the screening test. Also, the ruminant feed ban is rigorously enforced. Removal of specified risk materials such as brain and spinal cord from cattle is mandatory process at slaughter to prevent the infected material from entering the human food chain.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.10
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• pp.1599-1605
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• 2005

The object of this study is to develop the method for differentiating fresh meat from frozen meat by using the measurement of the mitochondrial malate dehydrogenase in the Korean native cattle. The principle of this experiment is based on the fact that the enzyme proteins associated with mitochondrial membrane could be released by freezing. The methods of differentiating fresh meat from thawed, frozen meat were studied by measurements of mitochondrial malate dehydrogenase activity of meat press juice. Fresh and frozen beef were stored at 4, -4, -18 and -77$^{\circ}C$ for 15-day storage period. A meat press machine using air pressure was manufactured especially for these experiments, and sufficient amount of drip (about 0.15 mL/g) from 1.5 g of beef sample was efficiently obtained under a pressure of 8 kg/$cm^{2}$ generated by the meat pressing machine. The mitochondrial malate dehydrogenase activities of frozen meat drip i년ices stored at -18 and -77$^{\circ}C$ were significantly higher than those of fresh and frozen meat samples at -4$^{\circ}C$ (p < 0.05) during 10-min reaction period. However, the enzyme activities of the frozen meat drip juices (-18 and -77$^{\circ}C$) disappeared after 5 minutes of the reaction, which was not observed from the fresh and -4$^{\circ}C$ frozen meats. The enzyme activity maintained until 12 minutes for the fresh and -4$^{\circ}C$ frozen meats. From these results, the mitochondrial malate dehydrogenase could be considered as an indicator to differentiate fresh beef from frozen one.

• Journal of Animal Science and Technology
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• v.52 no.5
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• pp.375-382
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• 2010

Twelve pigs were used to investigate the effects of polyclonal antibody candidate against abdominal (AAb) and subcutaneous adipocyte membrane proteins (SAb) on body weight, fecaldigestibility and blood metabolites. When AAb and SAb developed by Choi et al. (2010) were injected to pigs, the numerical increase in BW (body weight) occurred at 4 weeks post-treatment, but BW for an entire period was also increased, indicating that the BW increase may not be affected by the antibodies injection. Antibodies treatment did not affect (P>0.05) fecal digestibility of dry matter, crude protein, crude fat and crude fiber. Fecal digestibility of crude ash for control (no treatment) at 2 weeks decreased, and that for non-immunized serum treatmentgroup at 4 weeks post-treatment increased, respectively (P<0.05). However, fecal digestibility of crude ash for AAb and SAb groups did not significantly change. At 4 weeks after the antibodies treatment, blood urea N concentration for AAb and SAb groups was significantly increased (P<0.05). However, these increases may not be caused by the antibodies treatment because similar pattern in blood urea N concentration occurred before the antibodies treatment. Antibodies treatment did not affect concentration of plasma glucose and triglycerides (P<0.05). Compared with control, concentration of plasma total cholesterol for AAb and SAb groups at 4 weeks post-treatment was significantly (P<0.05) decreased. This may suggest that body fat reduction possibly occurs. In conclusion, the AAb and the SAb developed by Choi et al. (2010) may have safety in nutritional physiological metabolism in pigs. Further study on in vivo fat reduction of the antibodies against abdominal and subcutaneous adipocytes of pigs should be required for fat-reduced pork production.

• Journal of Life Science
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• v.27 no.10
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• pp.1199-1206
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• 2017

The lymphotoxin ${\beta}$ receptor ($LT{\beta}R$), a member of the tumor necrosis factor receptor family, plays an important role in lymphoid tissue's architecture and organogenesis. We found that $LT{\beta}R$ stimulation induced changes in stress fibers (SFs) in fibroblastic reticular cells (FRCs). MLCK and ROCK play critical roles in the regulation of SF formation in cells. The present study was performed to investigate the antifibrotic effects on SF regulation of $LT{\beta}R$ signaling, with a focus on MLCK inhibition. The effect of $LT{\beta}R$ on the SF change was analyzed using immunoblot and fluorescence assays and agonistic $anti-LT{\beta}R$ antibody-treated FRCs. In addition, we checked the level of Rho-guanosine diphosphate (GDP)/guanosine triphosphate (GTP) exchange activity with FRC lysate. Phospho-ezrin proteins acting as membrane-cytoskeleton linkers completely de-phosphorylated in agonistic $anti-LT{\beta}R$ antibody-treated FRCs. The actin bundles rearranged into SFs, where phospho-myosin light chain (p-MLC) co-localized in FRCs. ML7-treated FRCs completely blocked SFs and showed retraction and shrinkage processes comparable to those observed in agonistic $anti-LT{\beta}R$ antibody-treated cells. Inhibition of ROCK activity induced changes in the actin cytoskeleton organization; however, some SFs remained in the cells, while they were completely disrupted by MLCK inhibition with ML7. We showed that the phosphorylation of MLC was completely abolished with $LT{\beta}R$ stimulation in FRCs. When $LT{\beta}R$ was stimulated with the agonistic $anti-LT{\beta}R$ antibody, the Rho-GDP/GTP exchange activity was reduced, however, the activity was not completely abolished. Collectively, the results illustrated that MLCK was potently responsible for the SF regulation triggered via $LT{\beta}R$ signaling in FRCs.