• Journal of Microbiology
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• v.45 no.3
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• pp.187-192
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• 2007

REOviruses (Respiratory Enteric Orphan viruses) are ubiquitous, non-enveloped viruses containing 10 segments of double-stranded RNA (dsRNA) as their genome. They are common isolates of the respiratory and gastrointestinal tract of humans but are not associated with severe disease and are therefore considered relatively benign. An intriguing characteristic of reovirus is its innate oncolytic potential, which is linked to the transformed state of the cell. When immortalized cells are transfected in vitro with activated oncogenes such as Ras, Sos, v-erbB, or c-myc, they became susceptible to reovirus infection and subsequent cellular lysis, indicating that oncogene signaling pathways are exploited by reovirus. This observation has led to the use of the virus in clinical trials as an anti-cancer agent against oncogenic tumors. In addition to the exploitation of oncogene signaling, reovirus may further utilize host immune responses to enhance its antitumor activity in vivo due to its innate interferon induction ability. Reovirus is, however, not entirely benign to immunocompromised animal models. Reovirus causes so-called "black feet syndrome" in immunodeficient mice and can also harm neonatal animals. Because cancer patients often undergo immunosuppression due to heavy chemo/radiation-treatments or advanced tumor progression, this pathogenic response may be a hurdle in virus-based anticancer therapies. However, a genetically attenuated reovirus variant derived from persistent reovirus infection of cells in vitro is able to exert potent anti-tumor activity with significantly reduced viral pathogenesis in immunocompromised animals. Importantly, in this instance the attenuated, reovirus maintains its oncolytic potential while significantly reducing viral pathogenesis in vivo.

• Journal of Microbiology and Biotechnology
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• v.29 no.7
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• pp.1155-1164
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• 2019

Lichens contain diverse bioactive secondary metabolites with various chemical and biological properties, which have been widely studied. However, details of the inhibitory mechanisms of their secondary metabolites against influenza A virus (IAV) have not been documented. Here, we investigated the antiviral effect of lichen extracts, obtained from South Korea, against IAV in MDCK cells. Of the lichens tested, Nipponoparmelia laevior (LC24) exhibited the most potent inhibitory effect against IAV infection. LC24 extract significantly increased cell viability, and reduced apoptosis in IAV-infected cells. The LC24 extract also markedly reduced (~ 3.2 log-fold) IAV mRNA expression after 48 h of infection. To understand the antiviral mechanism of LC24 against IAV, proteomic (UPLC-$HDMS^E$) analysis was performed to compare proteome modulation in IAV-infected (V) vs. mock (M) and LC24+IAV (LCV) vs. V cells. Based on Ingenuity Pathway Analysis (IPA), LC24 inhibited IAV infection by modulating several antiviral-related genes and proteins (HSPA4, HSPA5, HSPA8, ANXA1, ANXA2, $HIF-1{\alpha}$, AKT1, MX1, HNRNPH1, HNRNPDL, PDIA3, and VCP) via different signaling pathways, including $HIF-1{\alpha}$ signaling, unfolded protein response, and interferon signaling. These molecules were identified as the specific biomarkers for controlling IAV in vitro and further confirmation of their potential against IAV in vivo is required. Our findings provide a platform for further studies on the application of lichen extracts against IAV.

• Biomolecules & Therapeutics
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• v.23 no.3
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• pp.238-244
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• 2015

Macrophage-derived chemokine, C-C motif chemokine 22 (MDC/CCL22), is one of the inflammatory chemokines that controls the movement of monocytes, monocyte-derived dendritic cells, and natural killer cells. Serum and skin MDC/CCL22 levels are elevated in atopic dermatitis, which suggests that the chemokines produced from keratinocytes are responsible for attracting inflammatory lymphocytes to the skin. A major signaling pathway in the interferon-${\gamma}$ (IFN-${\gamma}$)-stimulated inflammation response involves the signal transducers and activators of transcription 1 (STAT1). In the present study, we investigated the anti-inflammatory effect of dieckol and its possible action mechanisms in the category of skin inflammation including atopic dermatitis. Dieckol inhibited MDC/CCL22 production induced by IFN-${\gamma}$ (10 ng/mL) in a dose dependent manner. Dieckol (5 and $10{\mu}M$) suppressed the phosphorylation and the nuclear translocation of STAT1. These results suggest that dieckol exhibits anti-inflammatory effect via the down-regulation of STAT1 activation.

• IMMUNE NETWORK
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• v.9 no.5
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• pp.192-202
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• 2009

Background: Little information is available the role of Nitric Oxide (NO) in host defenses during human tuberculosis (TB) infection. We investigated the modulating factor(s) affecting NO synthase (iNOS) induction in human macrophages. Methods: Both iNOS mRNA and protein that regulate the growth of mycobacteria were determined using reverase transcriptase-polymerase chain reaction and western blot analysis. The upstream signaling pathways were further investigated using iNOS specific inhibitors. Results: Here we show that combined treatment with 1,25-dihydroxyvitamin D3 (1,25-D3) and Interferon (IFN)-${\gamma}$ synergistically enhanced NO synthesis and iNOS expression induced by Mycobacterium tuberculosis (MTB) or by its purified protein derivatives in human monocyte-derived macrophages. Both the nuclear factor-${\kappa}B$ and MEK1-ERK1/2 pathways were indispensable in the induction of iNOS expression, as shown in toll like receptor 2 stimulation. Further, the combined treatment with 1,25-D3 and IFN-${\gamma}$ was more potent than either agent alone in the inhibition of intracellular MTB growth. Notably, this enhanced effect was not explained by increased expression of cathelicidin, a known antimycobacterial effector of 1,25-D3. Conclusion: These data support a key role of NO in host defenses against TB and identify novel modulating factors for iNOS induction in human macrophages.

• Journal of Microbiology and Biotechnology
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• v.29 no.12
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• pp.2014-2021
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• 2019

Middle East respiratory syndrome coronavirus (MERS-CoV) belongs to the genus Betacoronavirus and causes severe morbidity and mortality in humans especially when infected patients have underlying diseases such as chronic obstructive pulmonary disease (COPD). Previously, we demonstrated that MERS-CoV-encoded ORF8b strongly inhibits MDA5- and RIG-I-mediated induction of the interferon beta (IFN-β) promoter activities. Here, we report that ORF8b seemed to regulate MDA5 or RIG-I differentially as protein levels of MDA5 were significantly down-regulated while those of RIG-I were largely unperturbed. In addition, ORF8b seemed to efficiently suppress phosphorylation of IRF3 at the residues of 386 and 396 in cells transfected with RIG-I while total endogenous levels of IRF3 remained largely unchanged. Furthermore, ORF8b was able to inhibit all forms of RIG-I; full-length, RIG-I-1-734, and RIG-I-1-228, the last of which contains only the CARD domains. Taken together, it is tempting to postulate that ORF8b may interfere with the CARD-CARD interactions between RIG-I and MAVS. Further detailed analysis is required to delineate the mechanisms of how ORF8b inhibits the MDA5/RIG-I receptor signaling pathway.

• International Journal of Oral Biology
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• v.36 no.2
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• pp.91-101
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• 2011

MspTL is the major surface protein of Treponema lecithinolyticum associated with periodontitis and endodontic infections. Our recent investigation revealed that MspTL induces proinflammatory cytokines and intercellular adhesion molecule 1 in THP-1 cells and periodontal ligament cells. In this study we conducted oligonucleotide microarray analysis to investigate the global transcriptional regulation in THP-1 cells stimulated with purified recombinant MspTL. MspTL upregulated the expression of 90 genes in THP-1 cells at least four fold, and the functions of these genes were categorized into adhesion, apoptosis/antiapoptosis, cell cycle/growth/differentiation, chemotaxis, cytoskeleton organization, immune response, molecular metabolism, proteolysis, signaling, and transcription. The majority of the modified genes are known to be NF-${\kappa}B$-responsive and interferon-stimulated genes (ISGs). The expression of 12 selected genes was confirmed by real-time RT-PCR. Because prostaglandin $E_2(PGE_2)$ is an important inflammatory mediator and Cox-2 was found to be induced by MspTL in the microarray analysis, we determined the level of $PGE_2$ in the culture supernatants of MspTL-treated cells and found that MspTL significantly increased $PGE_2$. Our results provide insight into the gene regulation of host cells in response to MspTL, and may contribute to the understanding of the molecular mechanism in periodontitis.

• Journal of Microbiology and Biotechnology
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• v.30 no.12
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• pp.1801-1809
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• 2020

Chikungunya virus (CHIKV) was first identified in 1952 as a causative agent of outbreaks. CHIKV is transmitted by two mosquito species, Aedes aegypti and A. albopictus. Symptoms after CHIKV infection in human are typically fever and joint pain, but can also include headache, muscle pain, joint swelling, polyarthralgia, and rash. CHIKV is an enveloped single-stranded, positive-sense RNA virus with a diameter of approximately 70 nm. The pathogenesis of CHIKV infection and the mechanism by which the virus evades the innate immune system remain poorly understood. Moreover, little is known about the roles of CHIKV-encoded genes in the viral evasion of host immune responses, especially type I interferon (IFN) responses. Therefore, in the present study, we screened CHIKV-encoded genes for their regulatory effect on the activation of nuclear factor kappa B (NF-κB), a critical transcription factor for the optimal activation of IFN-β. Among others, non-structural protein 2 (nsP2) strongly inhibited melanoma differentiation-associated protein 5 (MDA5)-mediated induction of the NF-κB pathway in a dose-dependent manner. Elucidation of the detailed mechanisms of nsP2-mediated inhibition of the MDA5/RIG-I signaling pathway is anticipated to contribute to the development of virus-specific therapeutics against CHIKV infection.

• Molecules and Cells
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• v.45 no.4
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• pp.257-272
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• 2022

In addition to inducing apoptosis, caspase inhibition contributes to necroptosis and/or autophagy depending on the cell type and cellular context. In macrophages, necroptosis can be induced by co-treatment with Toll-like receptor (TLR) ligands (lipopolysaccharide [LPS] for TLR4 and polyinosinic-polycytidylic acid [poly I:C] for TLR3) and a cell-permeable pan-caspase inhibitor zVAD. Here, we elucidated the signaling pathways and molecular mechanisms of cell death. We showed that LPS/zVAD- and poly I:C/zVAD-induced cell death in bone marrow-derived macrophages (BMDMs) was inhibited by receptor-interacting protein kinase 1 (RIP1) inhibitor necrostatin-1 and autophagy inhibitor 3-methyladenine. Electron microscopic images displayed autophagosome/autolysosomes, and immunoblotting data revealed increased LC3II expression. Although zVAD did not affect LPS- or poly I:C-induced activation of IKK, JNK, and p38, it enhanced IRF3 and STAT1 activation as well as type I interferon (IFN) expression. In addition, zVAD inhibited ERK and Akt phosphorylation induced by LPS and poly I:C. Of note, zVAD-induced enhancement of the IRF3/IFN/STAT1 axis was abolished by necrostatin-1, while zVAD-induced inhibition of ERK and Akt was not. Our data further support the involvement of autocrine IFNs action in reactive oxygen species (ROS)-dependent necroptosis, LPS/zVAD-elicited ROS production was inhibited by necrostatin-1, neutralizing antibody of IFN receptor (IFNR) and JAK inhibitor AZD1480. Accordingly, both cell death and ROS production induced by TLR ligands plus zVAD were abrogated in STAT1 knockout macrophages. We conclude that enhanced TRIF-RIP1-dependent autocrine action of IFNβ, rather than inhibition of ERK or Akt, is involved in TLRs/zVAD-induced autophagic and necroptotic cell death via the JAK/STAT1/ROS pathway.

• Korean Journal of Poultry Science
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• v.50 no.4
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• pp.193-202
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• 2023

Influenza IAVs are encapsulated negative-strand RNA viruses that infect many bird species' respiratory systems and can spread to other animals, including humans. This work reanalyzed previous microarray datasets to identify common and specific differentially expressed genes (DEGs) in chickens, as well as their biological activities. There were 760 and 405 DEGs detected in HPAIV and LPAIV-infected chicken cells, respectively. HPAIV and LPAIV have 670 and 315 DEGs, respectively, with both viruses sharing 90 DEGs. Because of HPAIV infection, numerous genes were implicated in a fundamental biological function of the cell cycle, according to the functional annotation of DEGs. Of the targeted genes, expressions of CDC Like Kinase 3 (CLK3), Nucleic Acid Binding Protein 1 (NABP1), Interferon-Inducible Protein 6 (IFI6), PIN2 (TERF1) Interacting Telomerase Inhibitor 1 (PINX1), and Cellular Communication Network Factor 4 (WISP1) were altered in DF-1 cells treated with polyinosinic:polycytidylic acid (PIC), a toll-like receptor 3 (TLR3) ligand, suggesting that transcription of these genes be controlled by TLR3 signaling. To gain a better understanding of the pathophysiology of AIVs in chickens, it is crucial to focus more research on unraveling the mechanisms through which AIV infections may manipulate host responses during the infection process. Insights into these mechanisms could facilitate the development of novel therapeutic strategies.

• The Korea Journal of Herbology
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• v.27 no.1
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• pp.65-71
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• 2012

Objective : Nelumbinis Folium (NF) is used for diarrhea, headache and dizziness in traditional medicine. In this paper, we examined the anti-inflammatory effects of the methanol extract of NF in mouse macrophages. Methods : Peritoneal macrophages from thioglycollate medium-injected mice were cultured and stimulated with lipopolysaccharide(LPS) or LPS/interferon(IFN)-${\gamma}$ for viability assay, cytokine measurement and Western blotting. Results : NF methanol extract suppressed the levels of nitric oxide (NO) through reduction of inducible NO synthase in a concentration-dependent manner. The extract reduced LPS/IFN-${\gamma}$-stimulated STAT1 phosphorylation and LPS-induced $I{\kappa}B{\alpha}$ degradation through inhibition of $I{\kappa}B{\alpha}$ kinase activation. The extract also inhibited p38, JNK/SAPK and ERK1/2 activation. Conclusions : Our findings suggested that NF has anti-inflammatory activity, and have a potential for therapeutic application. Further research is required to investigate its anti-inflammatory active compounds.