• Title/Summary/Keyword: viral pathogenesis

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Polyploidization of Hepatocytes: Insights into the Pathogenesis of Liver Diseases

  • Kim, Ju-Yeon;Choi, Haena;Kim, Hyeon-Ji;Jee, Yelin;Noh, Minsoo;Lee, Mi-Ock
    • Biomolecules & Therapeutics
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    • v.30 no.5
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    • pp.391-398
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    • 2022
  • Polyploidization is a process by which cells are induced to possess more than two sets of chromosomes. Although polyploidization is not frequent in mammals, it is closely associated with development and differentiation of specific tissues and organs. The liver is one of the mammalian organs that displays ploidy dynamics in physiological homeostasis during its development. The ratio of polyploid hepatocytes increases significantly in response to hepatic injury from aging, viral infection, iron overload, surgical resection, or metabolic overload, such as that from non-alcoholic fatty liver diseases (NAFLDs). One of the unique features of NAFLD is the marked heterogeneity of hepatocyte nuclear size, which is strongly associated with an adverse liver-related outcome, such as hepatocellular carcinoma, liver transplantation, and liver-related death. Thus, hepatic polyploidization has been suggested as a potential driver in the progression of NAFLDs that are involved in the control of the multiple pathogenicity of the diseases. However, the importance of polyploidy in diverse pathophysiological contexts remains elusive. Recently, several studies reported successful improvement of symptoms of NAFLDs by reducing pathological polyploidy or by controlling cell cycle progression in animal models, suggesting that better understanding the mechanisms of pathological hepatic polyploidy may provide insights into the treatment of hepatic disorders.

Panax ginseng as a potential therapeutic for neurological disorders associated with COVID-19; Toward targeting inflammasome

  • Seo Won Shin;Ik Hyun Cho
    • Journal of Ginseng Research
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    • v.47 no.1
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    • pp.23-32
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    • 2023
  • Coronavirus disease 2019 (COVID-19) is a highly infectious respiratory disease caused by a severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2). SARS-CoV-2 infection may cause clinical manifestations of multiple organ damage, including various neurological syndromes. There are currently two oral antiviral drugs-Paxlovid and molnupiravir-that are recognized to treat COVID-19, but there are still no drugs that can specifically fight the challenges of SARS-CoV-2 variants. Nucleotide-binding oligomerization domain-like receptor pyrin domain-containing-3 (NLRP3) inflammasome is a multimolecular complex that can sense heterogeneous pathogen-associated molecular patterns associated with neurological disorders. The NLRP3 activation stimulates the production of caspase-1-mediated interleukin (IL)-1β, IL-18, and other cytokines in immune cells. Panax (P.) ginseng is a medicinal plant that has traditionally been widely used to boost immunity and treat various pathological conditions in the nervous system due to its safety and anti-inflammatory/oxidant/viral activities. Several recent reports have indicated that P. ginseng and its active ingredients may regulate NLRP3 inflammasome activation in the nervous system. Therefore, this review article discusses the current knowledge regarding the pathogenesis of neurological disorders related to COVID-19 and NLRP3 inflammasome activation and the possibility of using P. ginseng in a strategy targeting this pathway to treat neurological disorders.

Cloning and Activity Analysis of the FosB Promoter Region from Human Genomic DNA (사람 핵DNA로부터 FosB 유전자 프로모터 클로닝 및 활성도 분석)

  • Na, Han-Heom;Kang, Yoonsung;Kim, Keun-Cheol
    • Journal of Life Science
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    • v.27 no.8
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    • pp.857-863
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    • 2017
  • The FBJ murine osteosarcoma viral oncogene homolog B (FosB) gene is located at chromosome 19, and encodes 43 Kda protein. Functionally, the FosB gene is important for differentiation, development, and pathogenesis. Furthermore, the FosB gene is suggested as possible biomarker for tracing disease prognosis. In this study, we constructed plasmid containing a FosB promoter region and evaluate its promoter activity. We analyzed the putative promoter region in FosB genomic DNA using bioinformatics program, and we found important regulatory elements in 1 Kb upstream from transcription start site (TSS). Therefore, we performed polymerase chain reaction (PCR) amplification on region from-1,555 upstream to +73 of the FosB genomic DNA, and PCR product was inserted into TA vector to create the $TA-1^{st}FosBp$ plasmid. We then prepared the primer sets, which contain a restriction enzyme site for Kpn1 and Nhe1, in order to reinsert into the TA vector to prepare $TA-2^{nd}FosBp$ plasmid. It was finally subcloned into pGL3-luc vector after enzyme cutting. To evaluate whether the cloned plasmid is useful in cell based experiment, we performed luciferase assay with pGL3-FosBp-luctransfection. FosB promoter activity was increased compared to empty vector, and this activity was significantly increased by treatment of doxorubicin and taxol. We obtained consistent data on regulation of FosB gene expression after anticancer drug treatment using Western blot analysis. The results suggest that promoter cloning of the human FosB gene is very useful for studying gene expression and analyzing biomarkers.

Zika Virus Proteins NS2A and NS4A Are Major Antagonists that Reduce IFN-β Promoter Activity Induced by the MDA5/RIG-I Signaling Pathway

  • Ngan, Nguyen Thi Thuy;Kim, Seong-Jun;Lee, Jeong Yoon;Myoung, Jinjong
    • Journal of Microbiology and Biotechnology
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    • v.29 no.10
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    • pp.1665-1674
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    • 2019
  • Zika virus (ZIKV) is a mosquito-transmitted, emerging Flavivirus that causes Guillain-$Barr{\acute{e}}$ syndrome and microcephaly in adults and fetuses, respectively. Since ZIKV was first isolated in 1947, severe outbreaks have occurred at various places worldwide, including Yap Island in 2007, French Polynesia in 2013, and Brazil in 2015. Although incidences of ZIKV infection and dissemination have drastically increased, the mechanisms underlying the pathogenesis of ZIKV have not been sufficiently studied. In addition, despite extensive research, the exact roles of individual ZIKV genes in the viral evasion of the host innate immune responses remain elusive. Besides, it is still possible that more than one ZIKV-encoded protein may negatively affect type I interferon (IFN) induction. Hence, in this study, we aimed to determine the modulations of the IFN promoter activity, induced by the MDA5/RIG-I signaling pathway, by over-expressing individual ZIKV genes. Our results show that two nonstructural proteins, NS2A and NS4A, significantly down-regulated the promoter activity of IFN-${\beta}$ by inhibiting multiple signaling molecules involved in the activation of IFN-${\beta}$. Interestingly, while NS2A suppressed both full-length and constitutively active RIG-I, NS4A had inhibitory activity only on full-length RIG-I. In addition, while NS2A inhibited all forms of IRF3 (full-length, regulatory domain-deficient, and constitutively active), NS4A could not inhibit constitutively active IRF3-5D. Taken together, our results showed that NS2A and NS4A play major roles as antagonists of MDA5/RIG-I-mediated IFN-${\beta}$ induction and more importantly, these two viral proteins seem to inhibit induction of the type I IFN responses in differential mechanisms. We believe this study expands our understanding regarding the mechanisms via which ZIKV controls the innate immune responses in cells and may pave the way to development of ZIKV-specific therapeutics.

Definition of the peptide mimotope of cellular receptor for hepatitis C virus E2 protein using random peptide library (Random peptide library를 이용한 C형 간염바이러스 E2 단백질 세포막 수용체의 peptide mimotope 규명)

  • Lee, In-Hee;Paik, Jae-Eun;Seol, Sang-Yong;Seog, Dae-Hyun;Park, Sae-Gwang;Choi, In-Hak
    • IMMUNE NETWORK
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    • v.1 no.1
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    • pp.77-86
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    • 2001
  • Background: Hepatitis C virus(HCV), a family of Flaviviridae, has a host cell-derived envelope containing a positive-stranded RNA genome, and has been known as the maj or etiological agent for chronic hepatitis, hepatic cirrhosis, and hepatocellular carcinoma. There remains a need to dissect a molecular mechanism of pathogenesis for the development of therapeutic and effective preventive measure for HCV. Identification of cellular receptor is of central importance not only to understand the viral pathogenesis, but also to exploit strategies for prevention of HCV. This study was aimed at identifying peptide mimotopes inhibiting the binding of E2 protein of HCV to MOLT-4 cell. Methods: In this study, phage peptide library displaying a random peptides consisting of 7 or 12 random peptides was employed in order to pan against E2 protein. Free HCV particles were separated from the immune complex forms by immunoprecipitation using anti-human IgG antibody, and used for HCV-capture ELISA. To identify the peptides inhibiting E2-binding to MOLT-4 cells, E2 protein was subj ect to bind to MOLT-4 cells under the competition with phage peptides. Results: Several phage peptides were selected for their specific binding to E2 protein, which showed the conserved sequence of SHFWRAP from 3 different peptide sequences. They were also able to recognize the HCV particles in the sera of HCV patients captured by monoclonal antibody against E2 protein. Two of them, showing peptide sequence of HLGPWMSHWFQR and WAPPLERSSLFY respectively, were revealed to inhibit the binding of E2 protein to MOLT-4 cell efficiently in dose dependent mode. However, few membrane-associated receptor candidates were seen using Fasta3 programe for homology search with these peptides. Conclusion: Phage peptides containing HLGPWMSHWFQR and WAPPLERSSLFY respectively, showed the inhibition of E2-binding to MOLT-4 cells. However, they did not reveal any homologues to cellular receptors from GenBank database. In further study, cellular receptor could be identified through the screening of cDNA library from MOLT-4 or hepatocytes using antibodies against these peptide mimotopes.

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Impact of Chronic Hepatitis B and Hepatitis C on Adverse Hepatic Fibrosis in Hepatocellular Carcinoma Related to Betel Quid Chewing

  • Jeng, Jen-Eing;Tsai, Meng-Feng;Tsai, Hey-Ru;Chuang, Lea-Yea;Lin, Zu-Yau;Hsieh, Min-Yuh;Chen, Shinn-Chern;Chuang, Wan-Lung;Wang, Liang-Yen;Yu, Ming-Lung;Dai, Chia-Yen;Tsai, Jung-Fa
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.2
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    • pp.637-642
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    • 2014
  • The pathogenesis of hepatocellular carcinoma (HCC) related to habitual betel quid (BQ) chewing is unclear. Risk of HCCis increased with adverse hepatic fibrosis. This study aimed to assess the impact of chronic viral hepatitis on adverse hepatic fibrosis in HCC related to BQ chewing. This hospital-based case-control study enrolled 200 pairs of age- and gender-matched patients with HCC and unrelated healthy controls. Serologic hepatitis B surface antigen (HBsAg), antibodies to hepatitis C virus (anti-HCV), ${\alpha}$-fetoprotein (AFP), and surrogate markers for significant hepatic fibrosis were measured. Information on substance-use habits was obtained with a questionnaire. By analysis of surrogate markers for hepatic fibrosis, the prevalence of significant hepatic fibrosis in patients chewing BQ was between 45.8% and 91.7%, whereas that for patients without BQ chewing was between 18.4% and 57.9%. The difference was significant (P <0.05 for each surrogate marker). Multivariate analysis indicated that cirrhosis with Child-Pugh C (odds ratio (OR) = 3.28; 95% confidence interval (CI), 1.29-8.37), thrombocytopenia (OR = 3.92, 95% CI, 1.77-8.68), AFP >400 mg/L (OR = 2.21, 95% CI, 1.05-4.66) and male gender (OR = 4.06, 95% CI, 1.29-12.77) were independent factors associated with habitual BQ chewing. In conclusion, adverse hepatic fibrosis and severe liver damage play important roles in the pathogenesis of BQ-related HCC, which could be aggravated by chronic hepatitis B and hepatitis C. BQ-cessation programs and prevention of chronic HBV/HCV infection are needed to prevent HCC related to BQ chewing.

Pathogenesis and pathogenicity for the porcine circovirus 2 Korean isolates in weaned pigs (국내 분리 porcine circovirus 2의 이유자돈에 대한 병원성 시험연구)

  • Roh, In-Soon;Lee, Kyung-Woo;Kim, Jae-Hoon;Han, Jeong-Hee;Jean, Young-Hwa
    • Korean Journal of Veterinary Research
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    • v.47 no.2
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    • pp.175-185
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    • 2007
  • This study was carried out to investigate the pathogenesis and pathogenicity of the porcine circovirus type 2 (PCV2) Korean isolate from weaned pigs. Twenty four weaned pigs, PCV2, porcine reproductive and respiratory syndrome virus (PRRSV) and porcine parvovirus (PPV) antibodies free, were allocated to 4 groups (n = 6). Six pigs were inoculated intranasally with PCV2 alone, 6 with PCV2 and PRRSV, 6 with the combined PCV2/PRRSV/PPV inoculum, and 6 were remained as a uninoculated negative control. Pigs were killed 3 and 6 weeks after inoculation and tissue samples examined for gross and microscopic lesions and for the presence of PCV2 antigens and nucleic acids. Experimentally inoculated pigs were evaluated for 3 considerations: 1. development of postweaning multisystemic wasting syndrome (PMWS), 2. distribution of viral antigens by immunohistochemistry and polymerase chain reaction (PCR), and 3. cytokine mRNA levels in lymph nodes. Pigs inoculated with PCV2/PRRSV/PPV showed typical clinical signs, gross findings, and histopathologic characteristics of PMWS. In the PCV2/PRRSV/PPV inoculated group, the PCV2 antigen was widely distributed in various parenchymal organs such as brain, spinal cord, tonsil, lymph nodes, lung, heart, liver, kidney, spleen, and peyer's patch. Lymph node mRNA expression of IL-$1{\alpha}$, IL-2R and IL-8 was determined by real-time PCR. The pigs of PCV2/PRRSV and PCV2/PRRSV/PPV inoculation group, the mRNA expression was characterized by a decrease of IL-$1{\alpha}$, IL-2R and IL-8. The decrease of cytokine mRNA represent the state of T cell immuno-suppression in pig, and nicely support the evidence for the impairment of immune system in pigs with PMWS. In conclusion, PCV2 infection and some additional infectious causes such as PRRSV and/or PPV are warranted for the presence of PMWS in weaned pigs in Korea.

Cellular and Molecular Roles of $\beta$ Cell Autoantigens, Macrophages and T Cells in the Pathogenesis of Automimmune Diabetes

  • Yoon, Ji-Won;Jun, Hee-Sook
    • Archives of Pharmacal Research
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    • v.22 no.5
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    • pp.437-447
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    • 1999
  • Type I diabetes, also known as insulin-dependent diabetes mellitus (IDDM) results from the destruction of insulin-producing pancreatic $\beta$ cells by a progressive $\beta$ cell-specific autoimmune process. The pathogenesis of autoimmune IDDM has been extensively studied for the past two decades using animal models such as the non-obese diabetic (NOD) mouse and the Bio-Breeding (BB) rat. However, the initial events that trigger the immune responses leading to the selective destruction of the $\beta$ cells are poorly understood. It is thought that $\beta$ cell auto-antigens are involved in the triggering of $\beta$ cell-specific autoimmunity. Among a dozen putative $\beta$ cell autoantigens, glutamic acid decarboxylase (GAD) has bee proposed as perhaps the strongest candidate in both humans and the NOD mouse. In the NOD mouse, GAD, as compared with other $\beta$ cell autoantigens, provokes the earliest T cell proliferative response. The suppression of GAD expression in the $\beta$ cells results in the prevention of autoimmune diabetes in NOD mice. In addition, the major populations of cells infiltrating the iselts during the early stage of insulitis in BB rats and NOD mice are macrophages and dendritic cells. The inactivation of macrophages in NOD mice results in the prevention of T cell mediated autoimmune diabetes. Macrophages are primary contributors to the creation of the immune environment conducive to the development and activation of $\beta$cell-specific Th1-type CD4+ T cells and CD8+ cytotoxic T cells that cause autoimmune diabetes in NOD mice. CD4+ and CD8+ T cells are both believed to be important for the destruction of $\beta$ cells. These cells, as final effectors, can kill the insulin-producing $\beta$ cells by the induction of apoptosis. In addition, CD8+ cytotoxic T cells release granzyme and cytolysin (perforin), which are also toxic to $\beta$ cells. In this way, macrophages, CD4+ T cells and CD8+ T cells act synergistically to kill the $\beta$ cells in conjunction with $\beta$ cell autoantigens and MHC class I and II antigens, resulting in the onset of autoimmune type I diabetes.

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Systemic and oral manifestations of Ebola virus disease (에볼라 바이러스 감염의 전신 및 구강내 소견)

  • Kim, Min Ji;Kim, Hui Young;Kim, Soung Min;Myoung, Hoon;Lee, Jong Ho
    • The Journal of the Korean dental association
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    • v.54 no.1
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    • pp.67-83
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    • 2016
  • Ebola virus disease is a lethal viral hemorrhagic fever that has been boiling in sub-Saharan Africa since 1970s. Last year, The Ebola virus epidemic that has spread not only mainly in West Africa, but also in locals such as USA, Europe and the Antipodes via infected travelers, was brought up. Human-to-human transmission of Ebola virus disease is known only through direct contact with the blood, secretions, tissues or other bodily fluids, including saliva. Although there has not been reported infection cases in the dental healthcare settings, the fact that the infection of the Ebola virus may be made from human secretions such as saliva suggests that there is a high risk of infection for the Ebola virus of dental healthcare workers. Therefore, it is important dental healthcare workers to identify infection-suspected patients through the oral findings for infection prevention. This article will review the oral signs and symptoms of Ebola virus disease and discuss the pathogenesis, treatment and prevention. Furthermore, Infection control guidelines for oral healthcare workers are also proposed.

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Cutaneous Manifestations Associated with Liver Diseases (간질환에 동반된 피부증상에 관한 연구)

  • Cho, Young-Sup;Choi, Jong-Soo;Kim, Ki-Hong;Lee, Heon-Ju
    • Journal of Yeungnam Medical Science
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    • v.2 no.1
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    • pp.167-174
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    • 1985
  • It has been well recognized that the various cutaneous manifestations associated with the liver diseases. A clinical study was made of 255 patients (AVH 84, LC 70, HC 41, CAH 26, CPH 23, AH11) with the liver diseases at Yeungnam University Hospital during the periods from May to November, 1985. The authors classified the cutaneous manifestations into 7 groups according to pathogenesis, and compared them with other reports. The results were as follows; 1. In 255 patients with various liver diseases, 161 patients (63%) showed the various cutaneous manifestations. 2. The various cutaneous manifestations were jaundice and/or pruritus (43.1%), vascular changes (39.6%), allergic manifestations (10.6%), nail changes (5.1%), hormone-induced changes (4.3%), pigmentary changes (3.5%) and others (2.4%) in that order. 3. Cutaneous manifestations were associated most frequently with liver cirrhosis (1.6 groups) and the least with chronic active hepatitis (0.7 group). 4. Allergic manifestations were seen mainly in patients with acute viral hepatitis. Three patients showed the serum sickness-like prodrome. 5. The other cutaneous manifestations were seen mainly in patients with chronic liver diseases.

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