• Title/Summary/Keyword: pathogenesis mechanism

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Nitric Oxide Scavenging Effect and Expression of Chemokine Genes in Bee Venom (봉약침액(蜂藥鍼液)의 NO 소거 및 Chemokine 유전자 발현에 대한 효과)

  • Cho, Tae-sung;Youn, Hyoun-min;Song, Choon-ho;Jang, Kyung-jeon;Ahn, Chang-beohm
    • Journal of Acupuncture Research
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    • v.20 no.4
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    • pp.53-65
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    • 2003
  • Although the effect of Bee Venom has been reported, its mechanism has not been fully elucidated. Nitric Oxide(NO) is one of the free radicals and mediates in inflammation diseases. Chemokines contribute to the pathogenesis of several disorders such as allergic rhinitis and rheumatoid arthritis and so on. The objective of this study was to investigate the scavenging effect of Bee Venom on NO and on expression of chemokine genes. There was no significant NO scavenging effect in Crude Bee Venom, Apamin, Melittin, and MCD-peptide. The expression of chemokines was examined by RT-PCR using the human mast cell line(HMC-1), which is known to secrete and express chemokines. In order to investigate the protective effect of Bee Venom, HMC-1 cells were incubated with pretreatment of Bee Venom for 24 hrs and stimulated with 1 uM calcium ionophore A23178 for 2 hrs. RT-PCR analyses of chemokine genes showed that expressions of RANTES and MCP-1 were increased compared to the calcium ionophore-only treated group. But IL-8 and MCP-3 did not express increasing effect compared to control group. This study may provide important basic data on the possibility of the clinical treatment of Bee Venom in inflammation diseases.

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Apo-1/Fas (CD95) Gene Polymorphism in Korean Knee Osteoarthritis Patients (한국인 무릎 골 관절염 환자들의 임상 양상과 Apo-1/Fas (CD95) 유전자 다형성과의 상관관계에 관한 연구)

  • Hong, Seung-Jae;Yang, Hyung-In;Yim, Sung-Vin;Chung, Joo-Ho;Jung, Young-Ok;Kim, Ho-Youn
    • IMMUNE NETWORK
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    • v.3 no.2
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    • pp.145-149
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    • 2003
  • Background: Apoptosis has been implicated in pathogenesis of various disease. Apo-1/Fas (CD95) is one of the main pathway of apoptosis. To examine the possible relationship between Apo-1/Fas (CD95) and primary knee osteoarthritis, MvaI restriction length polymorphism (RFLP) in human Apo-1/Fas (CD95) gene was assessed. Methods: Genotype and allele frequencies in promoter region in the Apo-1/Fas (CD95) gene were studied by PCR-RFLP in 226 Korean controls and 148 Korean patients with primary knee osteoarthritis. Results: No statistically significant difference in the genotypic distribution and allelic frequencies was found between the control and the knee oateoarthritis patients. But in the severe grade (grade 3, 4) Kellgren-Lawrence score patients, the frequency of $MvaI^*1$ (G) allele was significantly decreased (P=0.0392) and the of $MvaI^*2$ (A) allele frequency was significantly increased (P=0.0473) compared to the normal controls. Conclusion: Apo-1/Fas (CD95) gene polymorphism is a part a determinant factor of severity in knee osteoarthritis, the patients with $MvaI^*2$ (A) allele is more severe radiologic progression. Further substantiation studies are needed in larger patient samples and various other apoptosis related genes to elucidate the mechanism of osteoarthritis, including the Fas ligand gene analysis.

MicroRNA-206 Protects against Myocardial Ischaemia-Reperfusion Injury in Rats by Targeting Gadd45β

  • Zhai, Changlin;Qian, Qang;Tang, Guanmin;Han, Bingjiang;Hu, Huilin;Yin, Dong;Pan, Haihua;Zhang, Song
    • Molecules and Cells
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    • v.40 no.12
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    • pp.916-924
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    • 2017
  • MicroRNAs are widely involved in the pathogenesis of cardiovascular diseases through regulating gene expression via translational inhibition or degradation of their target mRNAs. Recent studies have indicated a critical role of microRNA-206 in myocardial ischaemia-reperfusion (I/R) injury. However, the function of miR-206 in myocardial I/R injury is currently unclear. The present study was aimed to identify the specific role of miR-206 in myocardial I/R injury and explore the underlying molecular mechanism. Our results revealed that the expression level of miR-206 was significantly decreased both in rat I/R group and H9c2 cells subjected to hypoxia/reoxygenation (H/R) compared with the corresponding control. Overexpression of miR-206 observably decreased infarct size and inhibited the cardiomyocyte apoptosis induced by I/R injury. Furthermore, bioinformatics analysis, luciferase activity and western blot assay proved that $Gadd45{\beta}$ (growth arrest DNA damage-inducible gene $45{\beta}$) was a direct target gene of miR-206. In addition, the expression of pro-apoptotic-related genes, such as p53, Bax and cleaved caspase3, was decreased in association with the down-regulation of $Gadd45{\beta}$. In summary, this study demonstrates that miR-206 could protect against myocardial I/R injury by targeting $Gadd45{\beta}$.

Dexamethasone induces the expression of LRRK2 and α-synuclein, two genes that when mutated cause Parkinson's disease in an autosomal dominant manner

  • Park, Ji-Min;Ho, Dong-Hwan;Yun, Hye Jin;Kim, Hye-Jung;Lee, Chan Hong;Park, Sung Woo;Kim, Young Hoon;Son, Ilhong;Seol, Wongi
    • BMB Reports
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    • v.46 no.9
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    • pp.454-459
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    • 2013
  • LRRK2 (leucine-rich repeat kinase 2) has been identified as a gene corresponding to PARK8, an autosomal-dominant gene for familial Parkinson's disease (PD). LRRK2 pathogenic-specific mutants induce neurotoxicity and shorten neurites. To elucidate the mechanism underlying LRRK2 expression, we constructed the LRRK2-promoter-luciferase reporter and used it for promoter analysis. We found that the glucocorticoid receptor (GR) transactivated LRRK2 in a ligand-dependent manner. Using quantitative RT-PCR and Western analysis, we further showed that treatment with dexamethasone, a synthetic GR ligand, induced LRRK2 expression at both the transcriptional and translational levels, in dopaminergic MN9D cells. Dexamethasone treatment also increased expression of ${\alpha}$-synuclein, another PD causative gene, and enhanced transactivation of the ${\alpha}$-synuclein promoter-luciferase reporter. In addition, dexamethasone treatment to MN9D cells weakly induced cytotoxicity based on an LDH assay. Because glucocorticoid hormones are secreted in response to stress, our data suggest that stress might be a related factor in the pathogenesis of PD.

NICKEL INCORPORATION INTO Klebsiella aerogenes UREASE (Klebsiella aerogenes Urease로의 닉켈의 도입)

  • Lee, Mann-Hyung-
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1994.11a
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    • pp.69-80
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    • 1994
  • Although ureases play important roles in microbial nitrogen metabolism and in the pathogenesis of several human diseases, little is known of the mechanism of metallocenter biosynthesis in this Ni-Containing enzyme. Klebsiella aerogenes urease apo-protein was purified from cells grown in the absence of Ni. The purified apo-enzyme showed the same native molecular weight, charge, and subunit stoichiometry as the holo-enzyme. Chemical modification studies were consistent with histidinyl ligation of Ni. Apo-enzyme could not be activated by simple addition of Ni ions suggesting a requirement for a cellular factor. Deletion analysis showed that four accessory genes (ureD, ureE, ureF, and ureG) are necessary for the functional incorporation of the urease metallocenter. Whereas the $\Delta$ureD, $\Delta$ureF, and $\Delta$ureG mutants are inactive and their ureases lack Ni, the $\Delta$ureE mutants retain partial activity and their ureases possess corresponding lower levels of Ni. UreE and UreG peptides were identified by SDS-polyacrylamide gel comparisons of mutant and wild type cells and by N-terminal sequencing. UreD and UreF peptides, which are synthesized at ve교 low levels, were identified by using in vitro transcription/translation methods. Cotransformation of E. coli cells with the complementing plasmids confirmed that ureD and ureF gene products act in trans. UreE was purified and characterized. immunogold electron microscopic studies were used to localize UreE to the cytoplasm. Equilibrium dialysis studies of purified UreE with $^{63}$ NiC1$_2$ showed that it binds ~6 Ni in a specific manner with a $K_{d}$ of 9.6 $\pm$1.3 $\mu$M. Results from spectroscopic studies demonstrated that Ni ions are ligated by 5 histidinyl residues and a sixth N or O atom, consistent with participation of the polyhistidine tail at the carboxyl termini of the dimeric UreE in Ni binding. With these results and other known features of the urease-related gene products, a model for urease metallocenter biosynthesis is proposed in which UreE binds Ni and acts as a Ni donor to the urease apo-protein while UreG binds ATP and couples its Hydrolysis to the Ni incorporation process.ouples its Hydrolysis to the Ni incorporation process.s.

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Upregulation of Heme Oxygenase-1 as an Adaptive Mechanism against Acrolein in RAW 264.7 Macrophages

  • Lee, Nam-Ju;Lee, Seung-Eun;Park, Cheung-Seog;Ahn, Hyun-Jong;Ahn, Kyu-Jeung;Park, Yong-Seek
    • Molecular & Cellular Toxicology
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    • v.5 no.3
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    • pp.230-236
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    • 2009
  • Acrolein, a known toxin in cigarette smoke, is the most abundant electrophilic $\alpha$, $\beta$-unsaturated aldehyde to which humans are exposed in a variety of environmental pollutants, and is also product of lipid peroxidation. Increased unsaturated aldehyde levels and reduced antioxidant status plays a major role in the pathogenesis of various diseases such as diabetes, Alzheimer's and atherosclerosis. The findings reported here show that low concentrations of acrolein induce heme oxygenase-1 (HO-1) expression in RAW 264.7 macrophages. HO-1 induction by acrolein and signal pathways was measured using reverse transcription-polymerase chain reaction, Western blot and immunofluorescence staining analyses. Inhibition of extracellular signal-regulated kinase activity significantly attenuated the induction of HO-1 protein by acrolein, while suppression of Jun N-terminal kinase and p38 activity did not affect induction of HO-1 expression. Moreover, rottlerin, an inhibitor of protein kinase $\delta$, suppressed the upregulation of HO-1 protein production, possibly involving the interaction of NF-E2-related factor 2 (Nrf2), which has a key role as a HO-1 transcription factor. Acrolein elevated the nuclear translocation of Nrf2 in nuclear extraction. The results suggest that RAW 264.7 may protect against acrolein-mediated cellular damage via the upregulation of HO-1, which is an adaptive response to oxidative stress.

Effects of Nicotine and Tobacco-Specific Nitrosamine on Carcinogenesis (Nicotine 및 Tobacco-Specific Nitrosamine이 발암과정에 미치는 영향)

  • Kang, Ho-Il;Park, Mi-Sun;Kim, Ok-Hee
    • Environmental Mutagens and Carcinogens
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    • v.25 no.3
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    • pp.118-123
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    • 2005
  • Nicotine has been implicated as a potential factor in the pathogenesis of human lung cancer, however its mechanism of action in the development of lung cancer remains largely unknown. To explore the role of nicotine in the development of lung cancer, we first investigated the effects of nicotine on the expression of tumor associated genes by treating Sprague-Dawley rats with nicotine (10 mg/kg) by gavage once daily for 10 days. We determined the expression of proteins and mRNAs of the ras, raf, myc, jun, fos oncogenes and p53, Rb tumor suppressor genes by Western and Northern blotting, respectively. We did not detect any changes on the levels of proteins and mRNAs of these tumor associated genes in the lung of Sprague-Dawley rats from 3 days to 12 weeks after the last treatment of nicotine, indicating that nicotine appears to have no effect on expression of these oncogenes and tumor suppressor genes at an early stage in multistage chemical carcinogenesis. In a second experiment, we investigated the possibility that 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) could be formed endogenously by treating with nicotine and sodium nitrite. We treated groups of Fischer 344 rats with nicotine ($60{\mu}mol/kg$) and sodium nitrite ($180{\mu}mol/kg$), nicotine, sodium nitrite and NNK (120 nmol/kg) alone by gavage once daily for 7 days, respectively and determined the 8-hydroxydeoxyguanosine (8-OHdG), as an indicator of NNK formation, in the lungs of rats 24 hours and 48 hours after the last treatment by HPLC/ECD method. We detect increased level of 8-OHdG in the lungs of rats treated with NNK, but in the case of nicotine plus sodium nitrite, nicotine and sodium nitrite alone we could not detected any changes of 8-OHdG, respectively.

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Characteristics of Bovine Lymphoma Caused by Bovine Leukemia Virus Infection in Holstein-Friesian Dairy Cattle in Korea

  • Yoon, S.S.;Bae, Y.C.;Lee, K.H.;Han, B.;Han, H.R.
    • Asian-Australasian Journal of Animal Sciences
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    • v.18 no.5
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    • pp.728-733
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    • 2005
  • The frequency and distribution of lymphoma caused by bovine leukemia virus (BLV) infection in various organs were investigated. Lymphoma samples were obtained from slaughtered cattle or from cattle submitted to the National Veterinary Research and Quarantine Service, Korea. Thirty female Holstein-Friesian dairy cattle aged over three years with the BLV-associated lymphoma were studied. None of the Korean native cattle (Hanwoo) had lymphoma in this study however. Lymphoma tissues were gray to pink in color, soft in consistency, and bulged from the cut surface. In advanced lymphoma tissues, there was great variety in the appearance of involved structures due to hemorrhage, necrosis, and/or calcification. Neoplastic tissues were observed in lymph nodes in all lymphoma cases. Intestine (96.4%), heart (88.9%), stomach (73.1%), and diaphragm (62.5%) were frequently involved with lymphoma. However, there was no lymphoma detected in liver. Large neoplastic masses, sometimes reaching the size of over 20 cm, were found in the abdominal cavities. It is suggested that metastasis of lymphomas occurs mainly via lymph based on gross observations; neoplasia may have been initiated in the serosal surface of the lung, heart, peritoneum, and numerous hollow organs in the abdominal cavity. Also many organs in the abdominal and thoracic cavity were affected by neoplastic tissues simultaneously. Characteristics observed in this study could be used as criteria to differentiate BLV-associated lymphoma from other nodular lesions in the slaughterhouse and as fundamental data to make clear the mechanism of metastasis or pathogenesis of EBL.

Serum Adiponectin Level Association with Breast Cancer Risk: Evidence from a Case-Control Study

  • Ahmed, Syed Danish Haseen;Khanam, Aziza;Sultan, Naheed;Idrees, Farah;Akhter, Naheed
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.12
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    • pp.4945-4948
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    • 2015
  • Background: Adiponectin is a protein, synthesized by adipose tissue, which has a questionable role in breast cancer pathogenesis. This study focused on serum levels of adiponectin among cases and controls, and its possible association with breast cancer risk. Materials and Methods: This case-control study covered 175 diagnosed breast cancer patients with positive histopathology from Breast Clinic, surgical unit-1, Civil Hospital, Karachi and 175 healthy controls from various screening programs. Blood samples were obtained after an overnight fast and later analyzed. Results: Fasting blood glucose was significantly raised, while serum adiponectin was significantly decreased in breast cancer cases when compared to control subjects. To find the precise influence of serum adiponectin on the risk of breast cancer, subjects were divided in to quartiles based on serum levels of adiponectin. It is observed that risk of breast cancer decreased with rising quartile. Q2 (25th-50th) had the highest OR=1.76 (CI: 0.93- 3.34), Q3 (50th-75th) has OR= 0.89 (CI: 0.48-1.64), while subjects in the highest quartile Q4 (>75th) had significantly (p< 0.05) decreased risk of breast cancer having OR=0.06 (CI: 0.02-0.15), when compared to the lowest quartile. Conclusions: We demonstrated a statistically significant association of elevated serum adiponectin with decreased risk of breast cancer. This signifies a protective role of adiponectin via an intricate mechanism of masking mitogenic growth factors in breast carcinogenesis.

4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone Induces Retinoic Acid Receptor β Hypermethylation through DNA Methyltransferase 1 Accumulation in Esophageal Squamous Epithelial Cells

  • Wang, Jing;Zhao, Shu-Lei;Li, Yan;Meng, Mei;Qin, Cheng-Yong
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.5
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    • pp.2207-2212
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    • 2012
  • Overexpression of DNA methyltransferase 1 (DNMT1) has been detected in many cancers. Tobacco exposure is known to induce genetic and epigenetic changes in the pathogenesis of malignancy. 4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) is an important carcinogen present in tobacco smoke; however the detailed molecular mechanism of how NNK induces esophageal carcinogenesis is still unclear. We found that DNMT1 was overexpressed in ESCC tissues compared with paired non-cancerous tissues, the overexpression being correlated with smoking status and low expression of $RAR{\beta}$. The latter could be upregulated by NNK treatment in Het-1A cells, and the increased DNMT1 expression level reflected promoter hypermethylation and downregulation of retinoic acid receptor ${\beta}$($RAR{\beta}$). RNA interference mediated knockdown of DNMT1 resulted in promoter demethylation and upregulation of $RAR{\beta}$ in KYSE30 and TE-1 cells. 3-(4,5-Dimethyl-thiazol-2yl)-2,5-diphenyltetrazolium bromide (MTT) and flow cytometric analysis demonstrated that NNK treatment in Het-1A cells could enhance cell proliferation and inhibit cell apoptosis in a dose-dependent manner. In conclusion, DNMT1 overexpression is correlated with smoking status and low expression of $RAR{\beta}$ in esophageal SCC patients. NNK could induce $RAR{\beta}$ promoter hypermethylation through upregulation of DNMT1 in esophageal squamous epithelial cells, finally leading to enhancement of cell proliferation and inhibition of apoptosis.