• Biomedical Science Letters
• /
• v.22 no.1
• /
• pp.18-23
• /
• 2016

Ultraviolet (UV) irradiation induces cellular damage. A variety of cellular responses for repairing cellular damage including DNA damage occur after UV irradiation. During the repair processes, expression and activation of various molecules are regulated depending on the types of cellular damage. Parkin is an E3 ligase and act as a tumor suppressor. Recently, it has been reported that Parkin is involved in the DNA repair process. In the current study, we investigated whether UVB irradiation influences expression of Parkin. Parkin expression transiently decreased after UVB irradiation both at the mRNA and protein levels, but returned to normal levels thereafter. Taken together with cell viability data, Parkin expression is down-regulated during UVB-induced suppression of cell growth and is increased again in accordance with recovery of UVB-induced cell growth inhibition. However, Parkin overexpression or knockdown did not influence UVB-induced cell growth inhibition and recovery. We propose that Parkin could be a useful molecular marker for evaluating conditions of cells after UVB irradiation.

• Journal of Microbiology and Biotechnology
• /
• v.26 no.5
• /
• pp.928-937
• /
• 2016

S-Nitrosoglutathione reductase (GSNOR) metabolizes S-nitrosoglutathione (GSNO) and has been shown to play important roles in regulating cellular signaling and formulating host defense by modulating intracellular nitric oxide levels. The enzyme has been found in bacterial, yeast, mushroom, plant, and mammalian cells. However, to date, there is still no evidence of its occurrence in filamentous fungi. In this study, we cloned and investigated a GSNOR-like enzyme from the filamentous fungus Aspergillus nidulans. The enzyme occurred in native form as a homodimer and exhibited low thermal stability. GSNO was an ideal substrate for the enzyme. The apparent K_m and k_cat values were 0.55 mM and 34,100 min^-1, respectively. Substrate binding sites and catalytic center amino acid residues based on those from known GSNORs were conserved in this enzyme, and the corresponding roles were verified using site-directed mutagenesis. Therefore, we demonstrated the presence of GSNOR in a filamentous fungus for the first time.

• Proceedings of the Korean Nutrition Society Conference
• /
• 2003.05a
• /
• pp.263.1-263.1
• /
• 2003

• Proceedings of the KOSOMBE Conference
• /
• v.1998 no.11
• /
• pp.259-260
• /
• 1998

In this paper, we present a 3D visualization method of medical image on PC. Using morphological method, we used to segment 2D medical images (X-ray CT, MRI). Presented method is treating in some detail two operations : dilation and erosion. Also known as an isosurface, using a constant density surface make a target organ in 3D. In the whole procedure for visualization. The medical images are implemented by using Visual C++ 5.0 in activeX and IDL(interactive data language) under PC environment.

• Biomedical Science Letters
• /
• v.26 no.4
• /
• pp.288-295
• /
• 2020

Infection of Helicobacter pylori on gastric mucosa is associated with various gastric diseases. According to the WHO, H. pylori causes gastric cancer and has been classified as a class I carcinogen. Riboflavin is an essential vitamin which presents in a wide variety of foods. Previous studies have shown that riboflavin/UVA was effective against the growth inhibition of Staphylococcus aureus, S. epidermidis and multidrug-resistant Pseudomonas aeruginosa and had the potential for antimicrobial properties. Thus, we hypothesized that riboflavin has a potential role in the growth inhibition of H. pylori. To demonstrate inhibitory concentration of riboflavin against H. pylori, we performed agar and broth dilution methods. As a result, we found that riboflavin inhibited the growth of H. pylori. The MIC was 1 mM in agar and broth dilution test. Furthermore, to explain the inhibitory mechanism, we investigated whether riboflavin has an influence on the replication-associated molecules of the bacteria using RT-PCR to detect mRNA expression level in H. pylori. Riboflavin treatment of H. pylori led to down-regulation of polA and dnaB mRNA expression levels in a dose dependent manner. After then, we also confirmed whether riboflavin has cytotoxicity to human cells. We used AGS, a gastric cancer cell line, and treated with riboflavin did not show statistically significant decrease of cell viability. Thus, these results indicate that riboflavin can suppress the replication machinery of H. pylori. Taken together, these findings demonstrate that riboflavin inhibits growth of H. pylori by inhibiting replication of the bacteria.

• BMB Reports
• /
• v.45 no.9
• /
• pp.526-531
• /
• 2012

Many malignant tumors become resistant to tumor necrosis factor-alpha (TNF-${\alpha}$)-induced cell death during carcinogenesis. In the present study, we examined whether parkin acts as a tumor suppressor in HeLa cells, a human cervical cancer cell line resistant to TNF-${\alpha}$-induced cell death. TNF-${\alpha}$-treatment alone did not affect HeLa cell viability. However, expression of parkin restored TNF-${\alpha}$-induced apoptosis in HeLa cells. Increased cell death was due to the activation of the apoptotic pathway. Expression of parkin in TNF-${\alpha}$-treated HeLa cells stimulated cleavage of the pro-apoptotic proteins caspase-8, -9, -3, -7 and poly ADP ribose polymerase (PARP). In addition, parkin expression resulted in decreased expression of the caspase inhibitory protein, survivin. These results suggest that parkin acts as a tumor suppressor in human cervical cancer cells by modulating survivin expression and caspase activity. We propose that this pathway is a novel molecular mechanism by which parkin functions as a tumor suppressor.

• Biomedical Science Letters
• /
• v.17 no.3
• /
• pp.261-265
• /
• 2011

Parkin is a putative tumor suppressor protein and its expression is frequently reduced or absent in several types of tumors. In this study, we examined the role of Parkin in mRNA expression of monocyte chemotactic protein-1 (MCP-1) in the breast cancer cell line MCF7. Expression of MCP-1 mRNA increased after TNF-${\alpha}$ treatment. However, overexpression of Parkin induced a decrease in expression of MCP-1 mRNA in TNF-${\alpha}$-stimulated MCF7. This decrease in MCP-1 mRNA by Parkin overexpression occurred in a dose- and time-dependent manner. Using a wound scratch assay, we found that Parkin overexpression in MCF7 cells also resulted in a decrease in cell migration. These results suggest that Parkin down-regulates MCP-1 synthesis leading to decreased migration of tumor cells. We suggest that one possible mechanism by which Parkin acts as a tumor suppressor is by inhibiting migration or metastasis of cancer cells.

• Korean Journal of Veterinary Service
• /
• v.40 no.1
• /
• pp.71-74
• /
• 2017

The first case of liver infection caused by Sphingomonas sp. and Bacillus sp. in a wild rodent is reported. A captured wild rodent, Apodemus agrarius (A. agrarius), presented with multiple liver abscess-like nodules (diameter 0.7~2.4 mm) in which Gram-positive and Gram-negative bacilli were detected simultaneously. These were grown in aerobic and anaerobic cultures, respectively, and were identified as Sphingomonas sp. and Bacillus sp., respectively, according to 16S rRNA sequencing.

• Biomedical Science Letters
• /
• v.20 no.2
• /
• pp.70-76
• /
• 2014

In this study, we investigated the effect of DMSO, a highly dipolar organic liquid, in collagen ($5{\mu}g/ml$)-stimulated platelet aggregation. DMSO inhibited platelet aggregation at 0.5% by inhibiting production of thromboxane $A_2$ ($TXA_2$) which was associated with blocking cyclooxygenase (COX)-1 activity and $TXA_2$ synthase. In addition, DMSO significantly increased the formation of cyclic adenosine monophosphate (cAMP) from adenosine triphosphate (ATP) and cyclic guanosine monophosphate (cGMP) from guanosine triphosphate (GTP). On the other hand, DMSO (0.1~0.5% concentration) did not affect the LDH release which indicates the cytotoxicity. Based on these results, DMSO has anti-platelet effect by regulation of several platelet signaling pathways, therefore we suggest that DMSO could be a novel strategy on many thrombotic disorders.

• Biomedical Science Letters
• /
• v.19 no.3
• /
• pp.275-279
• /
• 2013

Etiological agents of extended spectrum ${\beta}$-lactamase (ESBL) producing uropathogenic Escherichia coli (UPEC) have become a major problem in urinary tract infections. The purpose of this study was to compare the molecular characteristics of ESBL producing UPEC strains isolated from 1989 and 2010. A total of 301 strains of UPEC clinical isolates was collected from Korean healthcare facility in 1989 (126 strains) and in 2010 (175 strains). UPEC clinical isolates were analyzed by multiplex polymerase chain reaction method (ESBL related bla genes and phylogenetic groups) and amplified fragment length polymorphism (AFLP). Among 301 isolates, ESBL producing UPEC were 8 strains (6.3%) in 1989 isolates and 35 strains (20%) in 2010 isolates. The rate of bla genes in ESBL producing UPEC from 1989 isolates and 2010 isolates were $bla_{TEM}$ (75% and 85.7%), $bla_{CTX-M}$ (0% and 91.4%), $bla_{OXA}$ (25% and 20%), $bla_{PER}$ (0% and 2.9%). The distribution of phylogenetic groups in 1989 isolates and 2010 isolates were A (37.5% and 11.4%), B2 (12.5% and 51.4%), and D (50% and 37.1%). The most prevalent ESBL related bla gene and phylogenetic group were $bla_{CTX-M}$ (91.4%) and B2 (51.4%) in 2010 isolates, while $bla_{CTX-M}$ was not detected in 1989 isolates. Among 43 ESBL producing UPEC were grouped into 12 clusters up to 76% of genetic similarities by AFLP analysis. During past twenty one years, the rate of the ESBL producing UPEC strains in 2010 isolates was increased than that of in 1989 isolates. Also, the most prevalent ESBL related bla gene has been changed from $bla_{TEM}$ to $bla_{CTX-M}$.