• Genomics & Informatics
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• v.16 no.4
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• pp.26.1-26.12
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• 2018

Shigella spp. constitutes some of the key pathogens responsible for the global burden of diarrhoeal disease. With over 164 million reported cases per annum, shigellosis accounts for 1.1 million deaths each year. Majority of these cases occur among the children of the developing nations and the emergence of multi-drug resistance Shigella strains in clinical isolates demands the development of better/new drugs against this pathogen. The genome of Shigella flexneri was extensively analyzed and found 4,362 proteins among which the functions of 674 proteins, termed as hypothetical proteins (HPs) had not been previously elucidated. Amino acid sequences of all these 674 HPs were studied and the functions of a total of 39 HPs have been assigned with high level of confidence. Here we have utilized a combination of the latest versions of databases to assign the precise function of HPs for which no experimental information is available. These HPs were found to belong to various classes of proteins such as enzymes, binding proteins, signal transducers, lipoprotein, transporters, virulence and other proteins. Evaluation of the performance of the various computational tools conducted using receiver operating characteristic curve analysis and a resoundingly high average accuracy of 93.6% were obtained. Our comprehensive analysis will help to gain greater understanding for the development of many novel potential therapeutic interventions to defeat Shigella infection.

• BMB Reports
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• v.52 no.9
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• pp.560-565
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• 2019

Benign prostatic hyperplasia (BPH), a common disease in elderly males, is accompanied by non-malignant growth of prostate tissues, subsequently causing hypoxia and angiogenesis. Although VEGF-related angiogenesis is one of the therapeutic targets of prostate cancer, there is no previous study targeting angiogenesis for treatment of BPH. Dihydrotestosterone (DHT)-induced expressions of vascular endothelial growth factor (VEGF) in prostate epithelial RWPE-1 cells and human umbilical vascular endothelial cells (HUVECs). Conditioned media (CM) from DHT-treated RWPE-1 cells were transferred to HUVECs. Then, 6SL inhibited proliferation, VEGFR-2 activation, and tube formation of HUVECs transferred with CM from DHT-treated RWPE-1 cells. In the rat BPH model, 6SL reduced prostate weight, size, and thickness of the prostate tissue. Formation of vessels in prostatic tissues were also reduced with 6SL treatment. We found that 6SL has an ameliorative effect on in vitro and in vivo the BPH model via inhibition of VEGFR-2 activation and subsequent angiogenesis. These results suggest that 6SL might be a candidate for development of novel BPH drugs.

• Journal of Neurogastroenterology and Motility
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• v.24 no.4
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• pp.577-583
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• 2018

Background/Aims Potassium-competitive acid blockers are expected to be the next generation of drugs for the treatment of diseases caused by gastric acid. In 2015, vonoprazan fumarate, a novel potassium-competitive acid blocker, was approved by the Japanese health insurance system. Since its approval, patients refractory to vonoprazan can be encountered in clinical settings. We designed this study to clarify the pathophysiology of gastroesophageal reflux disease refractory to vonoprazan. Methods In this retrospective study, we involved patients who had refractory symptoms after administration of standard-dose proton pump inhibitors or vonoprazan and underwent diagnostic testing with esophageal high-resolution manometry and 24-hour multichannel intraluminal impedance and pH monitoring while using proton pump inhibitors or vonoprazan. Patients were diagnosed based on the Rome IV criteria for functional gastrointestinal disorders and diagnostic test results. Results Twenty-seven patients were analyzed during this study. Gastric pH ${\geq}4$ was sustained for a longer period of time, and the esophageal acid exposure time and number of acid reflux events were shorter in the vonoprazan group than in the proton pump inhibitor group. The percentage of patients diagnosed with acidic gastroesophageal reflux disease in the vonoprazan group was lower than that in the proton pump inhibitor group. Conclusions Intra-gastric pH and acid reflux were strongly suppressed by 20-mg vonoprazan. When patients with gastroesophageal reflux disease present symptoms after administration of 20-mg vonoprazan, the possibility of pathophysiologies other than acid reflux should be considered.

• The Korean Journal of Physiology and Pharmacology
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• v.23 no.5
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• pp.393-402
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• 2019

Aurora kinases inhibitors, including ZM447439 (ZM), which suppress cell division, have attracted a great deal of attention as potential novel anti-cancer drugs. Several recent studies have confirmed the anti-cancer effects of ZM in various cancer cell lines. However, there have been no studies regarding the cardiac safety of this agent. We performed several cytotoxicity, invasion and migration assays to examine the anti-cancer effects of ZM. To evaluate the potential effects of ZM on cardiac repolarisation, whole-cell patch-clamp experiments were performed with human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) and cells with heterogeneous cardiac ion channel expression. We also conducted a contractility assay with rat ventricular myocytes to determine the effects of ZM on myocardial contraction and/or relaxation. In tests to determine in vitro efficacy, ZM inhibited the proliferation of A549, H1299 (lung cancer), MCF-7 (breast cancer) and HepG2 (hepatoma) cell lines with $IC_{50}$ in the submicromolar range, and attenuated the invasive and metastatic capacity of A549 cells. In cardiac toxicity testing, ZM did not significantly affect $I_{Na}$, $I_{Ks}$ or $I_{K1}$, but decreased $I_{hERG}$ in a dose-dependent manner ($IC_{50}$: $6.53{\mu}M$). In action potential (AP) assay using hiPSC-CMs, ZM did not induce any changes in AP parameters up to $3{\mu}M$, but it at $10{\mu}M$ induced prolongation of AP duration. In summary, ZM showed potent broad-spectrum anti-tumor activity, but relatively low levels of cardiac side effects compared to the effective doses to tumor. Therefore, ZM has a potential to be a candidate as an anti-cancer with low cardiac toxicity.

• BMB Reports
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• v.53 no.12
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• pp.622-627
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• 2020

Cancer stem cells (CSCs) or tumor-initiating cells are thought to play critical roles in tumorigenesis, metastasis, drug resistance, and tumor recurrence. For the diagnosis and targeted therapy of CSCs, the molecular identity of biomarkers or therapeutic targets for CSCs needs to be clarified. In this study, we identified CD166 as a novel marker expressed in the sphere-forming CSC population of A2780 epithelial ovarian cancer cells and primary ovarian cancer cells. The CD166+ cells isolated from A2780 cells and primary ovarian cancer cells highly expressed CSC markers, including ALDH1a1, OCT4, and SOX2, and ABC transporters, which are implicated in the drug resistance of CSCs. The CD166+ cells exhibited enhanced CSC-like properties, such as increased sphere-forming ability, cell migration and adhesion abilities, resistance to conventional anticancer drugs, and high tumorigenic potential in a xenograft mouse model. Knockdown of CD166 expression in the sphere-forming ovarian CSCs abrogated their CSC-like properties. Moreover, silencing of CD166 expression in the sphere-forming CSCs suppressed the phosphorylation of focal adhesion kinase, paxillin, and SRC. These results suggest that CD166 plays a key role in the regulation of CSC-like properties and focal adhesion kinase signaling in ovarian cancer.

• Journal of Microbiology and Biotechnology
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• v.31 no.1
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• pp.25-32
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• 2021

Inflammatory reactions activated by lipopolysaccharide (LPS) of gram-negative bacteria can lead to severe septic shock. With the recent emergence of multidrug-resistant gram-negative bacteria and a lack of efficient ways to treat resulting infections, there is a need to develop novel anti-endotoxin agents. Antimicrobial peptides have been noticed as potential therapeutic molecules for bacterial infection and as candidates for new antibiotic drugs. We previously designed the 9-meric antimicrobial peptide Pro9-3 and it showed high antimicrobial activity against gram-negative bacteria. Here, to further examine its potency as an anti-endotoxin agent, we examined the anti-endotoxin activities of Pro9-3 and elucidated its mechanism of action. We performed a dye-leakage experiment and BODIPY-TR cadaverine and limulus amebocyte lysate assays for Pro9-3 as well as its lysine-substituted analogue and their enantiomers. The results confirmed that Pro9-3 targets the bacterial membrane and the arginine residues play key roles in its antimicrobial activity. Pro9-3 showed excellent LPS-neutralizing activity and LPS-binding properties, which were superior to those of other peptides. Saturation transfer difference-nuclear magnetic resonance experiments to explore the interaction between LPS and Pro9-3 revealed that Trp3 and Tlr7 in Pro9-3 are critical for attracting Pro9-3 to the LPS in the gram-negative bacterial membrane. Moreover, the anti-septic effect of Pro9-3 in vivo was investigated using an LPS-induced endotoxemia mouse model, demonstrating its dual activities: antibacterial activity against gram-negative bacteria and immunosuppressive effect preventing LPS-induced endotoxemia. Collectively, these results confirmed the therapeutic potential of Pro9-3 against infection of gram-negative bacteria.

• Journal of Microbiology and Biotechnology
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• v.32 no.4
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• pp.522-530
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• 2022

In this study we aimed to develop novel ZnO-NP/chitosan/β-glycerophosphate (ZnO-NP/CS/β-GP) antibacterial hydrogels for biomedical applications. According to the mass fraction ratio of ZnO-NPs to chitosan, mixtures of 1, 3, and 5% ZnO-NPs/CS/β-GP were prepared. Using the test-tube inversion method, scanning electron microscopy and Fourier-transform infrared spectroscopy, the influence of ZnO-NPs on gelation time, chemical composition, and cross-sectional microstructures were evaluated. Adding ZnO-NPs significantly improved the hydrogel's antibacterial activity as determined by bacteriostatic zone and colony counting. The hydrogel's bacteriostatic mechanism was investigated using live/dead fluorescent staining and scanning electron microscopy. In addition, crystal violet staining and MTT assay demonstrated that ZnO-NPs/CS/β-GP exhibited good antibacterial activity in inhibiting the formation of biofilms and eradicating existing biofilms. CCK-8 and live/dead cell staining methods revealed that the cell viability of gingival fibroblasts (L929) cocultured with hydrogel in each group was above 90% after 24, 48, and 72 h. These results suggest that ZnO-NPs improve the temperature sensitivity and bacteriostatic performance of chitosan/β-glycerophosphate (CS/β-GP), which could be injected into the periodontal pocket in solution form and quickly transformed into hydrogel adhesion on the gingiva, allowing for a straightforward and convenient procedure. In conclusion, ZnO-NP/CS/β-GP thermosensitive hydrogels could be expected to be utilized as adjuvant drugs for clinical prevention and treatment of peri-implant inflammation.

• Journal of Microbiology and Biotechnology
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• v.32 no.6
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• pp.816-823
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• 2022

The rapid spread of superbugs leads to the escalation of infectious diseases, which threatens public health. Endolysins derived from bacteriophages are spotlighted as promising alternative antibiotics against multi-drug resistant bacteria. In this study, we isolated and characterized the novel Salmonella typhimurium phage PBST08. Bioinformatics analysis of the PBST08 genome revealed putative endolysin ST01 with a lysozyme-like domain. Since the lytic activity of the purified ST01 was minor, probably owing to the outer membrane, which blocks accessibility to peptidoglycan, antimicrobial peptide cecropin A (CecA) was fused to the N-terminus of ST01 to disrupt the outer membrane. The resulting CecA::ST01 has been shown to have increased bactericidal activity against gram-negative pathogens including Pseudomonas aeruginosa, Klebsiella pneumoniae, Acinetobacter baumannii, Escherichia coli, and Enterobacter cloacae and the most affected target was A. baumannii. In the presence of 0.25 µM CecA::ST01, A. baumannii ATCC 17978 strain was completely killed and CCARM 12026 strain was wiped out by 0.5 µM CecA::ST01, which is a clinical isolate of A. baumannii and resistant to multiple drugs including carbapenem. Moreover, the larvae of Galleria mellonella could be rescued up to 58% or 49% by the administration of CecA::ST01 upon infection by A. baumannii 17978 or CCARM 12026 strain. Finally, the antibacterial activity of CecA::ST01 was verified using 31 strains of five gram-negative pathogens by evaluation of minimal inhibitory concentration. Thus, the results indicate that a fusion of antimicrobial peptide to endolysin can enhance antibacterial activity and the spectrum of endolysin where multi-drug resistant gram-negative pathogens can be efficiently controlled.

• Archives of Obesity and Metabolism
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• v.1 no.1
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• pp.4-13
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• 2022

Currently, pharmacotherapy is becoming essential for obesity, owing to its expanding and increasing epidemiology. In this review, novel peptide-based drugs of four classes are covered: GLP-1 receptor agonist, GIP/GLP-1 receptor dual agonist, glucagon/GLP-1 receptor dual agonist, and a combination of amylin receptor agonist/GLP-1 receptor agonist. Semaglutide is a next-generation GLP-1 receptor agonist with a longer duration and stronger weight and glucose reduction effects than liraglutide and dulaglutide. In the STEP1 trial, semaglutide 2.4 mg reduced body weight by approximately 15% in people with obesity with similar or milder adverse events than liraglutide 3.0 mg. Tirzepatide, a GIP/GLP-1 receptor dual agonist, also has a long duration and strong weight- and glucose-lowering effect. According to SURPASS-2, 3, and 4, in patients with BMI≥25 kg/m² and type 2 diabetes mellitus (T2DM), tirzepatide 15 mg reduced the initial body weight by >13%. Cotadutide, a glucagon/GLP-1 receptor dual agonist, showed weaker weight-lowering effects than semaglutide and tirzepatide, while it was comparable to that of liraglutide in a phase 2 clinical trial for non-alcoholic fatty liver disease in patients with BMI≥25 kg/m² and T2DM. Additionally, its effect on the liver was noticeable. The long-acting amylin receptor agonist cargrilintide combined with semaglutide can be another effective option for obesity treatment. Even in a small phase 1 trial with a short study period of 20 weeks, cargrilintide 2.4 mg/semaglutide 2.4 mg reduced by 17% of initial body weight in people with BMI 27-39.9 kg/m². In coming several years, semaglutide, tirzepatide, and cargrilintide/semaglutide will become available for obesity treatment in Korea.

• The Journal of Korean Medicine
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• v.42 no.4
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• pp.120-132
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• 2021

Objectives: The prevalence of Parkinson's disease is on an upward trend along with an increase in the aging population but there is no available treatment that halts the progression of neurodegeneration. This study reports a numerical analysis on Donguibogam and suggests novel herbal drugs, which have never been researched before but found to be deemed effective in this study. Methods: Referring to 71 Korean medicine symptom terms that represent the symptoms of Parkinson's disease, 4170 prescriptions described in Donguibogam were classified into two groups based on whether their main effects were effective for Parkinson's disease or not. Comparing the two groups, the chi-square test was performed to select statistically significant herbs, while the t-test, Wilcoxon test, and descriptive statistics were performed to determine the appropriate dose. Results: One hundred and twenty-seven prescriptions effective for Parkinson's disease were identified. The chi-square test determined 17 herbs that are effective for symptomatic treatment. Among the medicinal herbs, the authors suggest Osterici seu Notopterygii Radix et Rhizoma, Ephedrae Herba, Aconiti Tuber, Myrrha, Sinomeni Caulis et Rhizoma, and Aconiti Kusnezoffii Tuber as herbal candidates that have never been studied for Parkinson's disease. Through the statistical tests, it was judged that the mean value of the dose of the entire prescription was the appropriate dose for each herb. Conclusions: Seventeen herbs were selected for Parkinson's disease and the appropriate daily dose were calculated. Furthermore, this study presented a new process that applies a statistical method to traditional medical literature and preselecting herbs deemed effective for specific diseases.