Renal Pathophysiology 2 : Peroxisome Proliferator-activated Receptor-gamma Agonist 15-Deoxy-△12, 14-prostaglandin J2 Induces Renal Epithelial Cell Death through Production of Reactive Oxygen Species and Inhibition of NF-κB Activity

권채화,강대식,박지연,김용근 대한신장학회 2006 춘계학술대회 초록집 Vol.25 No.1

Cell Proliferation and Activation of Survival Signaling Pathways by Hypoxia/reoxygenation in Renal Epithelial Cells

권채화,오현림,김용근 대한신장학회 2004 춘계학술대회 초록집 Vol.24 No.1

S100A8 and S100A9 Promotes Invasion and Migration through p38 Mitogen-Activated Protein

권채화,박도윤,문현정,박혜지,최진화 한국분자세포생물학회 2013 Molecules and cells Vol.35 No.3

S100A8 and S100A9 (S100A8/A9) are low-molecular weight members of the S100 family of calcium-binding proteins. Recent studies have reported S100A8/A9 promote tumorigenesis. We have previously reported that S100A8/A9 is mostly expressed in stromal cells and inflammatory cells between gastric tumor cells. However, the role of environmental S100A8/A9 in gastric cancer has not been defined. We observed in the present study the effect of S100A8/A9 on migration and invasion of gastric cancer cells. S100A8/ A9 treatment increased migration and invasionat lower concentrations that did not affect cell proliferation and cell viability. S100A8/A9 caused activation of p38 mitogen-activated protein kinase (MAPK) and nuclear factor-B (NF-B). The phosphorylation of p38 MAPK was not affected by the NF-B inhibitor Bay whereas activation of NF-B was blocked by p38 MAPK inhibitor SB203580, indicating that S100A8/A9-induced NF-B activation is mediated by phosphorylation of p38 MAPK. S100A8/A9-induced cell migration and invasion was inhibited by SB203580 and Bay, suggesting that activation of p38 MAPK and NF-B is involved in the S100A8/A9 induced cell migration and invasion. S100A8/A9 caused an increase in matrix metalloproteinase 2 (MMP2) and MMP12 expression, which were inhibited by SB203580 and Bay. S100A8/A9-induced cell migration and invasion was inhibited by MMP2 siRNA and MMP12 siRNA, indicating that MMP2 and MMP12 is related to the S100A8/A9 induced cell migration and invasion. Taken together, these results suggest that S100A8/A9 pro-motes cell migration and invasion through p38 MAPK-dependent NF-B activation leading to an increase of MMP2 and MMP12 in gastric cancer.

Renal Physiology 2 : Modulation of Cisplatin-induced Apoptosis by MAPK Signalling in Renal Proximal Epithelial Cells

권채화 ( Kwon Chae Hwa ),오현림 ( O Hyeon Lim ),김종민 ( Kim Jong Min ),김용근 ( Kim Yong Geun ) 대한신장학회 2003 춘계학술대회 초록집 Vol.22 No.1

Roles of Reactive Oxygen Species and Ca2+ in Ciglitazone-Induced Apoptosis in Opossum Kidney Cells

권채화 ( Chae Hwa Kwon ),박지연 ( Ji Yeon Park ),김태현 ( Thae Hyun Kim ),김용근 ( Yong Keun Kim ) 대한신장학회 2008 춘계학술대회 초록집 Vol.28 No.1

The Effect of Antioxidants on the Production of Pro-Inflammatory Cytokines and Orthodontic Tooth Movement

채화성,박현정,황효린,권아랑,임원희,이원진,한동헌,김영호,백정화 한국분자세포생물학회 2011 Molecules and cells Vol.32 No.2

Orthodontic force causes gradual compression of the periodontal ligament tissues, which leads to local hypoxia in the compression side of the tissues. In this study, we investigated whether antioxidants exert a regulatory effect on two factors: the expression of pro-inflammatory cytokines in human periodontal ligament fibroblasts (PDLFs)that were exposed to mechanical compression and hypoxia and the rate of orthodontic tooth movement in rats. Exposure of PDLFs to mechanical compression (0.5-3.0g/㎠) or hypoxic conditions increased the production of intracellular reactive oxygen species. Hypoxic treatment for 24 h increased the mRNA levels of IL-1β, IL-6 and IL-8as well as vascular endothelial growth factor (VEGF) in PDLFs. Resveratrol (10 nM) or N-acetylcysteine (NAC, 20mM) diminished the transcriptional activity of hypoxiainducible factor-1 and hypoxia-induced expression of VEGF. Combined treatment with mechanical compression and hypoxia significantly increased the expression levels of IL-1β, IL-6, IL-8, TNF-α and VEGF in PDLFs. These levels were suppressed by NAC and resveratrol. The maxillary first molars of rats were moved mesially for seven days using an orthodontic appliance. NAC decreased the amount of orthodontic tooth movement compared to the vehicletreated group. The results from immunohistochemical staining demonstrated that NAC suppressed the expression of IL-1β and TNF-α in the periodontal ligament tissues compared to the vehicle-treated group. These results suggest that antioxidants have the potential to negatively regulate the rate of orthodontic tooth movement through the down-regulation of pro-inflammatory cytokines in the compression sides of periodontal ligament tissues.

Alterations in Membrane Transport Function and Cell Viability Induced by ATP Depletion in Primary Cultured Rabbit Renal Proximal Tubular Cells

이성주,권채화,김용근 대한약리학회 2009 The Korean Journal of Physiology & Pharmacology Vol.13 No.1

This study was undertaken to elucidate the underlying mechanisms of ATP depletion-induced membrane transport dysfunction and cell death in renal proximal tubular cells. ATP depletion was induced by incubating cells with 2.5 mM potassium cyanide (KCN)/0.1 mM iodoacetic acid (IAA), and membrane transport function and cell viability were evaluated by measuring Na+-dependent phosphate uptake and trypan blue exclusion, respectively. ATP depletion resulted in a decrease in Na+-dependent phosphate uptake and cell viability in a time-dependent manner. ATP depletion inhibited Na+-dependent phosphate uptake in cells, when treated with 2 mM ouabain, a Na+ pump-specific inhibitor, suggesting that ATP depletion impairs membrane transport functional integrity. Alterations in Na+-dependent phosphate uptake and cell viability induced by ATP depletion were prevented by the hydrogen peroxide scavenger such as catalase and the hydroxyl radical scavengers (dimethylthiourea and thiourea), and amino acids (glycine and alanine). ATP depletion caused arachidonic acid release and increased mRNA levels of cytosolic phospholipase A2 (cPLA2). The ATP depletion-dependent arachidonic acid release was inhibited by cPLA2 specific inhibitor AACOCF3. ATP depletion-induced alterations in Na+-dependent phosphate uptake and cell viability were prevented by AACOCF3. Inhibition of Na+-dependent phosphate uptake by ATP depletion was prevented by antipain and leupetin, serine/cysteine protease inhibitors, whereas ATP depletion-induced cell death was not altered by these agents. These results indicate that ATP depletion-induced alterations in membrane transport function and cell viability are due to reactive oxygen species generation and cPLA2 activation in renal proximal tubular cells. In addition, the present data suggest that serine/cysteine proteases play an important role in membrane transport dysfunction, but not cell death, induced by ATP depletion.

Whole-Exome Sequencing in Papillary Microcarcinoma: Potential Early Biomarkers of Lateral Lymph Node Metastasis

김미진,권채화,장민희,김정미,김은희,전윤경,김상수,최경운,김인주,박미영,김보현 대한내분비학회 2021 Endocrinology and metabolism Vol.36 No.5

Background: Early identification of patients with high-risk papillary thyroid microcarcinoma (PTMC) that is likely to progress hasbecome a critical challenge. We aimed to identify somatic mutations associated with lateral neck lymph node (LN) metastasis (N1b)in patients with PTMC. Methods: Whole-exome sequencing (WES) of 14 PTMCs with no LN metastasis (N0) and 13 N1b PTMCs was performed usingprimary tumors and matched normal thyroid tissues. Results: The mutational burden was comparable in N0 and N1b tumors, as the median number of mutations was 23 (range, 12 to46) in N0 and 24 (range, 12 to 50) in N1b PTMC (P=0.918). The most frequent mutations were detected in PGS1, SLC4A8,DAAM2, and HELZ in N1b PTMCs alone, and the K158Q mutation in PGS1 (four patients, Fisher’s exact test P=0.041) was significantly enriched in N1b PTMCs. Based on pathway analysis, somatic mutations belonging to the receptor tyrosine kinase-RAS andNOTCH pathways were most frequently affected in N1b PTMCs. We identified four mutations that are predicted to be pathogenic infour genes based on Clinvar and Combined Annotation-Dependent Depletion score: BRAF, USH2A, CFTR, and PHIP. A missensemutation in CFTR and a nonsense mutation in PHIP were detected in N1b PTMCs only, although in one case each. BRAF mutationwas detected in both N0 and N1b PTMCs. Conclusion: This first comprehensive WES analysis of the mutational landscape of N0 and N1b PTMCs identified pathogenic genesthat affect biological functions associated with the aggressive phenotype of PTMC.

Cisplatin-induced Alterations of Na+-dependent Phosphate Uptake in Renal Epithelial Cells

이성주,권채화,김용근 대한약리학회 2007 The Korean Journal of Physiology & Pharmacology Vol.11 No.2

Cisplatin treatment increases the excretion of inorganic phosphate in vivo. However, the mechanism by which cisplatin reduces phosphate uptake through renal proximal tubular cells has not yet been elucidated. We examined the effect of cisplatin on Na+-dependent phosphate uptake in opossum kidney (OK) cells, an established proximal tubular cell line. Cells were exposed to cisplatin for an appropriate time period and phosphate uptake was measured using [32P]-phosphate. Changes in the number of phosphate transporter in membranes were evaluated by kinetic analysis, [14C]phosphonoformic acid binding, and Western blot analysis. Cisplatin inhibited phosphate uptake in a time- and dose-dependent manner, and also the Na+-dependent uptake without altering Na+-independent uptake. The cisplatin inhibition was not affected by the hydrogen peroxide scavenger catalase, but completely prevented by the hydroxyl radical scavenger dimethylthiourea. Antioxidants were ineffective in preventing the cisplatin-induced inhibition of phosphate uptake. Kinetic analysis indicated that cisplatin decreased Vmax of Na+-dependent phosphate uptake without any change in the Km value. Na+-dependent phosphonoformic acid binding was decreased by cisplatin treatment. Western blot analysis showed that cisplatin caused degradation of Na+-dependent phosphate transporter protein. Taken together, these data suggest that cisplatin inhibits phosphate transport in renal proximal tubular cells through the reduction in the number of functional phosphate transport units. Such effects of cisplatin are mediated by production of hydroxyl radicals.

호두 추출물의 항산화 활성과 신피질에서 세포 손상과 지질과산화 방지효과

배계선,황을철,권채화,김순희,최춘환,Bae Kae Sun,Hwang Eul Chul,Kwon Chae Hwa,Kim Soon Hee,Choi Chun Whan 한국생명과학회 2005 생명과학회지 Vol.15 No.1

본 연구에서는 호두박 분획층의 항산화 활성을 검색하기 위해 MeOH, $CH_2Cl_2$, EtOAc, BuOH 그리고 $H_2O$ 분획으로 추출하여 수행하였고, 각 분획층의 산화적 세포손상과 지질 과산화의 방지 효과를 in vitro에서 확인하였다. 그 결과 호두박의 free radical (DPP보 radical) 소거 활성은 EtOAc층에서 가장높게 나타났고, 활성산소종 억제율과 peroxynitrite $(ONOO^-)$ 소거 활성은 $CH_2Cl_2$층을 제외한 모든 분획층에서 높게 나타났다. 신피질 절편에 t-BHP의 처리 시 LDH의 방출과 지질과 산화를 증가시켰고 이러한 변화는 호두의 MeOH, EtOAc, n-BuOH 분획에 의해서 완전하게 방지되었다. 이러한 결과는 호두 추출물이 t-BHP에 의한 신장 세포 손상에 효과적이고 이러한 효과는 항산화력에 의한 것으로 추측된다. 또한 이러한 결과는 호두 추출물에서 많은 질병의 원인이 되고 있는 산화적 스트레스를 방지할 수 있는 효과적인 약물 개발의 가능성을 시사한다 To investigate the antioxidant activity of extract from the raw walnut, Juglans sinensis Dode, we prepared five fractions (methanol (MeOH), dichloromethane $(CH_2Cl_2)$, ethyl acetate (EtOAc), n-buthanol (n-BuOH) and dehydrogen monooxide $(H_2O)$ fractions) and examined. The effect of walnut extract on the oxidative stress was investigated in vitro. The DPPH (2,2-Di (4-tert-octylphenyl)-1-picrylhydrazyl) free radical scavenging activity of extract from raw walnut was shown in the following order: $EtOAc\;fraction<n-BuOH fraction< MeOH fraction<CH_2Cl_2\;fraction<H_2O$ layer. The result showed that the highest activity $(0.56{\mu}g/ml,\;IC_{50}.)$ was observed in EtOAc fraction, whereas n-BuOH fraction, MeOH fraction, $CH_2O_2$ fraction and $H_2O$ layer of $IC_{50}$ were $2.34{\mu}g//ml,\;3.88{\mu}g/ml,\;8.06{\mu}g/ml,\;and\;8.19{\mu}g/ml$, respectively. The radical scavenging activity assay of each fraction showed that the antioxidative activity was observed in the following order: EtOAc fraction $(74.27\pm1.56\%)>MeOH\;fraction\;(60.76\pm3.4\%)>n-BuOH\;fraction\;(59.32\pm0.88\%)>H_2O\;layer\;(41.69\pm2.06\%)$. These results revealed that all fractions, except for $CH_2Cl_2$ fraction, showed high antioxidative activity. Furthermore, the peroxynitrite $(ONOO^-)$ scavenging activity was assayed in each fraction. The result showed that the $ONOO^-$ scavenging activity of EtOAc fraction, MeOH fraction and n-BuOH fraction from raw walnut was $95.14\pm0.36\%,\; 90.02\pm1.19\%\;and\;89.41\pm0.81\%$, respectively. The tert-butylhydroperoxide (t-BHP) treatment in vitro increased lactate dehydrogenase release and lipid peroxidation in renal cortical slices. Such changes were completely prevented by addition of MeOH fraction, EtOAc fraction and n-BuOH fraction of walnut. These results indicate that the walnut extract exerts the benedicial effect against t-BHP-induced cell injury and its effect may be due to antioxidant action. In addition, it is suggested that walnut extract might be developed as the effective scavenger for the prevention of oxidative stress.