• Environmental Analysis Health and Toxicology
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• v.20 no.3 s.50
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• pp.215-221
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• 2005

Environmental polycyclic aromatic hydrocarbones (PAHs), which are formed during incomplete combustion of fossil fuels, are widely distributed in our environment. Human exposure to PAHs may occur through smoking, polluted air, food consumption and occupational contact. Urinary naphthols, 1-and 2-naphthol, have been suggested as route -specific biomarkers for exposure to airborne PAHs. Cytochrome p450 2E1 (CYP2E1) is known to be a great importance for the metabolism of organic solvents, which is a precacinogens with small molecular weight. This study describes the metabolic differences between PstI and RsaI polymorphisms (c1 allele: PstI-. RsaI+ ; c2 allele: PstI+, RsaI-) of CYP2E1 5-flanking region by genetically modified HepG2 cells, which overexpress the polymorphic regions. The results of CAT assay and western blot in the c2 allele overexpressed cells have higher activities than the cl allele over-expressing cells. However, the metabolism of naphthalene to 2-naphthol has no difference due to the two genotypes. In this study, we established the CYP2E1 polymorphic allele transduced HepG2 cells to screen susceptibility -differences in PAH exposure. In conclusion, the CYP2E1 polymorphism may hardly induce susceptibility differences in PAH exposure monitoring with urinary naphthols.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.28 no.5
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• pp.364-371
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• 2002

Many chemical compopunds are converted into reactive electrophilic metabolites by the oxidative(Phase I) enzymes, which are mainly cytochrome P-450 enzyme(CYPs). Phase II conjugating enzymes, such as glutathione S-transferase(GST), usually act as inactivation of enzymes. Genetic polymorphisms have been found to be associated with increased susceptibility to cancer of the lung, bladder, breast and colorectal. Many of the polymorphic genes of carcinogen metabolism show considerably different type of cancer among different ethnic groups as well as individuals within the same group. The aim of this study is (1) to establish the frequencies of genetic polymorphisms of GSTM1 and CYP1A1 in Korean oral squamous cell carcinoma(SCC), (2) to associate oral SCC with the risk of these genetic polymorphisms. The genetic polymorphisms of the GSTM1 and the CYP1A1 genes among 50 Korean oral SCC were analyzed using polymerase chain reaction(PCR). The results suggest that the homozygote and the mutant type of CYP1A1 MspI polymorphisms may be associated with genetic susceptibility to oral SCC in Korean. A combination of the GSTM1 null type with the homozygote(m1/m1), and the mutant(m2/m2) type of CYP1A1 MspI polymorphisms showed a relatively high risk of oral SCC in Korean. In the smoking group, the GSTM1 wild genotype may be the high risk factor of oral SCC in Korean. These data coincide with the hypothesis which states that different susceptibility to cancer of genetic polymorphisms exist among different ethnic group and different types of human cancer.

• YAKHAK HOEJI
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• v.59 no.2
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• pp.59-65
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• 2015

KR-67500, trans-4-(2-(4-methyl-1,1-dioxido-6-(2,4,6-trichlorophenyl)-1,2,6-thiadiazinan-2-yl)acetamido)adamantane-1-carboxamide, is a novel $11{\beta}$-HSD1 inhibitor with its therapeutic effects of its anti-diabetic, anti-adipogenic and anti-osteoporotic activity. This study was performed to evaluate in vitro and in vivo pharmacokinetic properties of KR-67500 as a new drug candidate. KR-67500 was stable and highly bound to proteins in rat plasma. The microsomal stabilities of KR-67500 in human and rat liver were high. The inhibitory effect of KR-67500 for five cytochrome P450 enzymes was low. Preclinical pharmacokinetic studies have been carried out with intravenous or oral administrations of KR-67500 (10 mg/kg) to male rats and monkey. KR-67500 showed low clearance (0.68 l/h/kg) and high oral bioavailability (102%) in male rats. These results suggest that KR-67500 has good drug-like pharmacokinetic properties with a low first-pass effect and high bioavailability for an oral therapeutic agent of diabetes and osteoporosis.

• Molecular & Cellular Toxicology
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• v.5 no.3
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• pp.179-186
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• 2009

Hexachlorobenzene (HCB) is a bioaccumulative, persistent, and toxic pollutant. HCB is one of the 12 priority of Persistent Organic Pollutants (POPs) intended for global action by the United Nations Environment Program (UNEP) Governing Council. POPs are organic compounds that are resistant to environmental degradation through chemical, biological, and photolytic processes. Some of HCB is ubiquitous in air, water, soil, and biological matrices, as well as in major environmental compartments. HCB has effects on various organs such as thyroid, bone, skin, kidneys and blood cells and especially, revealed strong toxicity to liver. In this study, we identified genes related to hepatotoxiciy induced by HCB in human hepatocellular carcinoma (HepG2) cells using microarray and gene ontology (GO) analysis. Through microarray analysis, we identified 96 up- and 617 down-regulated genes changed by more than 1.5-fold by HCB. And after GO analysis, we determined several key pathways which known as related to hepatotoxicity such as metabolism of xenobiotics by cytochrome P450, complement and coagulation cascades, and tight junction. Thus, our present study suggests that genes expressed by HCB may provide a clue for hepatotoxic mechanism of HCB and gene expression profiling by toxicogenomic analysis also affords promising opportunities to reveal potential new mechanistic markers of toxicity.

• Journal of Nutrition and Health
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• v.50 no.3
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• pp.217-224
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• 2017

Purpose: Although it is well known thatmortality and morbidity due to cardiovascular diseases are higher in salt-sensitive subjects than in salt-resistant subjects, their underlying mechanisms related to obesity remain unclear. Here, we focused on salt-sensitive gene variants unrelated to monogenic obesity that interacted with sodium intake in humans. Methods: This review was written based on the modified $3^rd$ step of Khans' systematic review. Instead of the literature, subject genes were based on candidate genes screened from our preliminary Genome-Wide Association Study (GWAS). Finally, literature related to five genes strongly associated with salt sensitivity were analyzed to elucidate the mechanism of obesity. Results: Salt sensitivity is a measure of how blood pressure responds to salt intake, and people are either salt-sensitive or salt-resistant. Otherwise, dietary sodium restriction may not be beneficial for everyone since salt sensitivity may be associated with inherited susceptibility. According to our previous GWAS studies, 10 candidate genes and 11 single nucleotide polymorphisms (SNPs) associated with salt sensitivity were suggested, including angiotensin converting enzyme (ACE), ${\alpha}$-adducin1 (ADD1), angiotensinogen (AGT), cytochrome P450 family 11-subfamily ${\beta}$-2 ($CYP11{\beta}$-2), epithelial sodium channel (ENaC), G-protein b3 subunit (GNB3), G protein-coupled receptor kinases type 4 (GRK4 A142V, GRK4 A486V), $11{\beta}$-hydroxysteroid dehydrogenase type-2 (HSD $11{\beta}$-2), neural precursor cell-expressed developmentally down regulated 4 like (NEDD4L),and solute carrier family 12(sodium/chloride transporters)-member 3 (SLC 12A3). We found that polymorphisms of salt-sensitive genes such as ACE, $CYP11{\beta}$-2, GRK4, SLC12A3, and GNB3 may be positively associated with human obesity. Conclusion: Despite gender, ethnic, and age differences in genetics studies, hypertensive obese children and adults who are carriers of specific salt-sensitive genes are recommended to reduce their sodium intake. We believe that our findings can contribute to the prevention of early-onset of chronic diseases in obese children by facilitating personalized diet-management of obesity from childhood to adulthood.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.194-199
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• 2002

Many oxidative metabolites of tetrahydrocannabinols (THCs), active components of marijuana, were pharmacologically active, and 11-hydroxy-THCs, 11-oxo-${\Delta}^8$-THC, 7-oxo-${\Delta}^8$-THC, 8$\beta$, 9$\beta$-epoxyhexahydrocannabinol (EHHC), 9$\alpha$, l0$\alpha$-EHHC and 3'-hydroxy-${\Delta}^9$-THC were more active than THC in pharmacological effects such as catalepsy, hypothermia and barbiturate synergism in mice. Cannabidiol (CBD), another major component, was biotransfomred to two novel metabolites, 6-hydroxymethyl-${\Delta}^9$-THC and 3-pentyl-6, 7, 7a, 8, 9, lla-hexahydro-I, 7-dihydroxy-7, 1O-dimethyldibenzo[b, d]oxepin (PHDO) through 8R, 9-epoxy-CBD and 85, 9-epoxy-CBD, respectively. Both metabolites exhibited some pharmacological effects comparable to d9 - THe. Cannabinol (CBN), the other major component, was mainly metabolized to ll-hydroxy-CBN by hepatic microsomes of animals including humans. The pharmacological effects of the metabolite were higher than those of CBN demonstrating that II-hydroxylation of CBN is metabolic activation pathway of the cannabinoid as is the case in THCs. Tolerance and reciprocal cross-tolerance developed to pharmacological effects d8 - THC and ll-hydroxy-d8-THC , and the magnitude of tolerance development produced by the metabolite was significantly higher than that by d8-THC. The results indicate that ll-hydroxy-d8-THC has an important role not only in the pharmacological effects but also its tolerance development of d8 - THe. THCs and their metabolites competed to the specific binding of CP-55, 940, an agonist of cannabinoid receptor, to synaptic membrane from bovine cerebral cortex. The Ki value of THCs and their metabolites were closely paralleled to their pharmacological effects in mice. A novel cytochrome P450 (cyp2c29) was purified and identified as a major enzyme responsible for the metabolic activation of d8-THC at the II-position in the mouse liver. cDNA of CYP2C29 was cloned from a mouse cDNA library and its sequence was determined. The oxidation mechanism of THC by cyp2c29 was proposed.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.2
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• pp.187-196
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• 2020

Objective: Porcine respiratory disease is one of the most important health problems causing significant economic losses. To understand the genetic basis for susceptibility to swine enzootic pneumonia (EP) in pigs, we detected 102,809 single nucleotide polymorphisms in a total of 249 individuals based on genome-wide sequencing data. Methods: Genome comparison of susceptibility to swine EP in three pig breeds (Jinhua, Erhualian, and Meishan) with two western lines that are considered more resistant (Duroc and Landrace) using cross-population extended haplotype homozygosity and F-statistic (F_ST) statistical approaches identified 691 positively selected genes. Based on quantitative trait loci, gene ontology terms and literature search, we selected 14 candidate genes that have convincible biological functions associated with swine EP or human asthma. Results: Most of these genes were tested by several methods including transcription analysis and candidate genes association study. Among these genes: cytochrome P450 1A1 and catenin beta 1 (CTNNB1) are involved in fertility; transforming growth factor beta receptor 3 plays a role in meat quality traits; Wnt family member 2, CTNNB1 and transcription factor 7 take part in adipogenesis and fat deposition simultaneously; plasminogen activator, urokinase receptor (completely linked to AXL receptor tyrosine kinase, r² = 1) plays an essential role in the successful ovulation of matured oocytes in pigs; colipase like 2 (strongly linked to SAM pointed domain containing ETS transcription factor, r² = 0.848) is involved in male fertility. Conclusion: These adverse genes susceptible to swine EP may be selected while selecting for economic traits (especially reproduction traits) due to pleiotropic and hitchhiking effect of linked genes. Our study provided a completely new point of view to understand the genetic basis for susceptibility or resistance to swine EP in pigs thereby, provides insight for designing sustainable breed selection programs. Finally, the candidate genes are crucial due to their potential roles in respiratory diseases in a large number of species, including human.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.1
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• pp.495-499
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• 2014

Estrogens are considered the major breast cancer risk factor, and the carcinogenic potential of estrogens might be attributed to DNA modification caused by derivatives formed during metabolism. $17{\beta}$-estradiol ($E_2$), the main steroidal estrogen present in women, is metabolized via two major pathways: formation of 2-hydroxyestradiol (2-OH $E_2$) and 4-hydroxyestradiol ($4-OH\;E_2$) through the action of cytochrome P450 (CYP) 1A1 and 1B1, respectively. Previous reports suggested that $2-OH\;E_2$ has putative protective effects, while $4-OH\;E_2$ is genotoxic and has potent carcinogenic activity. Thus, the ratio of $2-OH\;E_2/4-OH\;E_2$ is a critical determinant of the toxicity of $E_2$ in mammary cells. In the present study, we investigated the effects of berberine on the expression profile of the estrogen metabolizing enzymes CYP1A1 and CYP1B1 in breast cancer MCF-7 cells. Berberine treatment produced significant induction of both forms at the level of mRNA expression, but with increased doses produced 16~ to 52~fold greater induction of CYP1A1 mRNA over CYP1B1 mRNA. Furthermore, berberine dramatically increased CYP1A1 protein levels but did not influence CYP1B1 protein levels in MCF-7 cells. In conclusion, we present the first report to show that berberine may provide protection against breast cancer by altering the ratio of CYP1A1/CYP1B1, could redirect $E_2$ metabolism in a more protective pathway in breast cancer MCF-7 cells.

• Experimental and Molecular Medicine
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• v.50 no.11
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• pp.8.1-8.14
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• 2018

We previously demonstrated that the direct transplantation of human umbilical cord blood-derived mesenchymal stem cells (hUCB-MSCs) into the dentate gyrus ameliorated the neurological symptoms of Niemann-Pick type C1 (NPC1)-mutant mice. However, the clinical presentation of NPC1-mutant mice was not fully understood with a molecular mechanism. Here, we found 14,15-epoxyeicosatrienoic acid (14,15-EET), a cytochrome P450 (CYP) metabolite, from hUCB-MSCs and the cerebella of NPC1-mutant mice and investigated the functional consequence of this metabolite. Our screening of the CYP2J family indicated a dysregulation in the CYP system in a cerebellar-specific manner. Moreover, in Purkinje cells, CYP2J6 showed an elevated expression level compared to that of astrocytes, granule cells, and microglia. In this regard, we found that one CYP metabolite, 14,15-EET, acts as a key mediator in ameliorating cholesterol accumulation. In confirming this hypothesis, 14,15-EET treatment reduced the accumulation of cholesterol in human NPC1 patient-derived fibroblasts in vitro by suppressing cholesterol synthesis and ameliorating the impaired autophagic flux. We show that the reduced activity within the CYP system in the cerebellum could cause the neurological symptoms of NPC1 patients, as 14,15-EET treatment significantly rescued cholesterol accumulation and impaired autophagy. We also provide evidence that the intranasal administration of hUCB-MSCs is a highly promising alternative to traumatic surgical transplantation for NPC1 patients.

• The Korean Journal of Physiology and Pharmacology
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• v.3 no.1
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• pp.83-91
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• 1999

Angiotensin II (ANG II) has a biphasic effect on $Na^+$ transport in proximal tubule: low doses of ANG II increase the $Na^+$ transport, whereas high doses of ANG II inhibit it. However, the mechanisms of high dose ANG II-induced inhibition on $Na^+$ uptake are poorly understood. Thus the aim of the present study was to investigate signal transduction pathways involved in the ANG II-induced inhibition of $Na^+$ uptake in the primary cultured rabbit renal proximal tubule cells (PTCs) in hormonally defined serum-free medium. ANG II $(10^{-9}\;M)-induced$ inhibition of $Na^+$ uptake was blocked by losartan $(10^{-8}\;M,\;AT_1\;antagonist),$ but not by PD123319 $(10^{-8}\;M,\;AT_2\;antagonist)$ (P<0.05). ANG II-induced inhibition of $Na^+$ uptake was also completely abolished by neomycin $(10^{-4}\;M,$ PLC inhibitor), W-7 $(10^{-4}\;M,$ calmodulin antagonist), and $AACOCF_3\;(10^{-6}\;M,\;PLA_2\;inhibitor)$ (P<0.05). ANG II significantly increased $[^3H]arachidonic$ acid (AA) release compared to control. The ANG II-induced $[^3H]AA$ release was blocked by losartan, $AACOCF_3,$ neomycin, and W-7, but not by PD123319. ANG II-induced $[^3H]AA$ release in the presence of extracellular $Ca^{2+}$ was greater than in $Ca^{2+}-free$ medium, and it was partially blocked by TMB-8 $(10^{-4}\;M,$ intracelluar $Ca^{2+}$ mobilization blocker). However, in the absence of extracellular $Ca^{2+},$ it was completely blocked by TMB-8. In addition, econazole $(10^{-6}\;M,$ cytochrome P-450 monooxygenase inhibitor) and indomethacin $(10^{-6}\;M,$ cyclooxygenase inhibitor) blocked ANG II-induced inhibition of $Na^+$ uptake, but NGDA $(10^{-6}\;M,$ lipoxygenase inhibitor) did not affect it. In conclusion, $PLA_2-mediated$ AA release is involved in ANG II-induced inhibition of $Na^+$ uptake and is modulated by $[Ca^{2+}]_i$ in the PTCs.