• Korean Journal of Ecology and Environment
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• v.48 no.2
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• pp.86-94
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• 2015

Chironomous is aquatic insect belonging to order Diptera, family Chironomidae. Their larval stage can be found mainly in aquatic benthic environment, hence good model organism to study environmental toxicology assessments and consider as useful bio indicators of contamination of the aquatic environment. In this study, Chironomus Heat Shock Proteins, Cytochrome 450, Glutathione S-transferase, Serine-type endopeptidase gene expressions were compared between polluted field areas (Chironomus plumosus) and under laboratory conditions (Chironomus riparious) to investigate molecular indicators for environmental contaminant stress assessment. Heavy metal (Al, Fe, Mn, Cu, Cr, Zn, Se, Pb, As, Cd) concentrations in sediments collected from three study areas exceeded the reference values. Moreover, HSPs, CYP450 and GST gene expression except SP for C. plumosus showed higher expression than C. riparious gene expression. Similar gene expression pattern was observed in C. riparious that exposed environment waters up to 96 h when compared to C. plumosus exposed to waters that grown in lab conditions. In summary, this comparative gene expression analysis in Chironomous between field and laboratory condition gave useful information to select candidate molecular indicators in heavy metal contaminations in the environment.

• Journal of Microbiology and Biotechnology
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• v.9 no.6
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• pp.798-803
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• 1999

Prolyl endopeptidase [PEP; EC 3.4.21.26], a serine protease which is known to cleave peptide bonds on the carboxy side of a proline residue, plays an important role in the degradation of proline-containing neuropeptides that have been suggested to participate in learning and memory processes. An abnormal increase in the level of PEP, which can lead to generation of $A{\beta}$, is also suggested to be involved in Alzheimer's type senile dementia. In the course of screening PEP inhibitors from Basidiomycetes, the mushroom Polyozellus multiplex exhibited a high inhibitory activity against PEP. Two active compounds were isolated from the ethyl acetate soluble fraction by consecutive purification, using silica gel, Sephadex LH-20, and Lobar RP-18 chromatography. The chemical structures of these compounds were identified as thelephoric acid and 12-acety1-2,3,7,8-tetrahydroxy-[12H]-12-hydroxymethylbenzobis[I.2b,3.4b'] benzofuran-11-one (kynapcin-9) by spectral data including UV, IR, MS, HR-MS, $^1H-,{\;}^{13}C-$, and 2D-NMR. The $IC_{50}$ values of the thelephoric acid and kynapcin-9 were 0.157 ppm (446nM) and 0.087 ppm (212nM) and their inhibitor constants ($K_i$) were 0.73ppm ($2.09{\;}\mu\textrm{m}$) and 0.060 ppm (146 nM), respectively. Furthermore, they were non-competitive with a substrate in Dixon plots.

• Korean Journal of Ecology and Environment
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• v.53 no.2
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• pp.165-172
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• 2020

Heavy metals are common pollutants in the freshwater environment and have toxicological effect in habitat organisms. The heavy metals highly accumulated in sediment and organism, and observed various physiological responses. In this study, we investigated the molecular response to heavy metal toxicity (Al, Aluminum; Cr, Chromium; Cu, copper; Mn, Manganese; Zn, Zinc) through expression of heat shock protein 40, 70, 90 (HSP40, 70, 90), cytochrome 450 (CYP450), Glutathione S-transferase (GST) and Serine-type endopeptidase (SP). HSPs showed up-regulation in Cu and Zn exposures. Furthermore, HSPs expression in treated groups tended to be higher than the control group. The tendency of CYP450 and GST mRNA expression was higher for Cr and Cu than for other exposure group. The expression of SP gene was low at Al exposure and other group were measured to be similar to control. These results suggest that heavy metal toxicity in freshwater ecosystem may affect physiological and molecular process. Also, the comprehensive gene expression in the aquatic midge Chironomus riparius give useful information to potential molecular biomarkers for assessing heavy metal toxicity.

• Journal of dental hygiene science
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• v.21 no.4
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• pp.227-232
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• 2021

Background: Cancer-associated fibroblasts (CAFs) are abundant in tumor microenvironments and interact with cancer cells to promote tumor proliferation in oral squamous cell carcinoma (OSCC). Cathepsin D (CTSD) is a soluble lysosomal aspartic endopeptidase involved in tumor proliferation and angiogenesis. In this preliminary study, we observed CTSD expression in OSCC and CAFs, postulating that CTSD might act as a bridge between OSCC and CAFs. Methods: Human epidermal keratinocytes (HEKs), OSCC, and immortalized human normal oral fibroblasts (hTERT-hNOFs) were used in this study. Additionally, we used hTERT-hNOFs transfected with an empty vector, WT (wild-type)-YAP (Yes-associated protein), and YAPS127A (YAP serine 127 to alanine). YAP127A hTERT-hNOFs activated fibroblasts similar to CAFs. To identify CTSD expression between OSCC and CAFs, conditioned medium (CM) was collected from each cell. Protein expression of CTSD was identified by western blotting. Results: To identify the expression of CTSD in fibroblasts stimulated by OSCC, we treated fibroblasts with CM from HEK and OSCC. Results indicated that hTERT-hNOFs with OSCC CM showed a weakly increased expression of CTSD compared to stimulation by HEK CM. This indicates that CAFs, YAPS127 hTRET-hNOFs, overexpress CTSD protein. HEK cells showed no CTSD expression, regardless of treatment with fibroblast CM, whereas OSCC highly expressed CTSD proteins compared with the CTSD expression in HEK cells. We also found that CTSD expression was unaffected by changes in transforming growth factor-β levels. Conclusion: This study proposes that CTSD might have potential as an interacting executor between OSCC and CAFs. Further studies are needed to investigate the role of CTSD in tumor and stromal cells.