• 대한의생명과학회지
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• 제23권3호
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• pp.175-184
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• 2017

Cholera toxin (CT) is an ADP-ribosylating bacterial exotoxin that has been used as an adjuvant in animal studies of oral immunization. The mechanisms of mucosal immunogenicity and adjuvanticity of CT remain to be established. In this study, we investigated the role of indoleamine 2,3-dioxygenase (IDO), which participates in the induction of immune tolerance, in CT-mediated breakdown of oral tolerance. When IDO-deficient ($IDO^{-/-}$) mice and their littermates were given oral ovalbumin, significant changes in antibody responses, footpad swelling and $CD4^+$ T cell proliferation were not observed in $IDO^{-/-}$ mice. Feeding of CT decreased IDO expression in mesenteric lymph nodes (MLN) and Peyer's patch (PP). CT-induced downregulation of IDO expression was reversed by inhibitors of nuclear factor-kappa B (NF-${\kappa}B$), pyrrolidine dithiocarbamate and p50 small interfering RNA. IDO expression was downregulated by the NF-${\kappa}B$ inducers lipopolysaccharide and tumor necrosis factor-${\alpha}$. CT dampened IDO activity and mRNA expression in dendritic cells from MLN and PP. These data indicate that CT disrupts oral tolerance by activating NF-${\kappa}B$, which in turn downregulates IDO expression. This study betters the understanding of the molecular mechanism underlying CT-mediated abrogation of oral tolerance.

• Journal of Applied Biological Chemistry
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• 제65권1호
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• pp.23-31
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• 2022

Oxidative stress and neuroinflammation play important roles in the pathogenesis of Alzheimer's disease (AD). This study investigated the protective effects of paeoniflorin (PF) against neuronal oxidative stress and neuroinflammation in lipopolysaccharide (LPS)-induced mice. The brains of LPS-injected control group showed significantly increased neuroinflammation by activating the nuclear factor kappa B (NF-κB) pathway and increasing inflammatory mediators. However, administration of PF significantly attenuated oxidative stress by inhibiting lipid peroxidation, nitric oxide levels, and reactive oxygen species production in the brain; PF at doses of 5 and 10 mg/kg/day downregulated the expression of NF-κB pathway-related proteins and significantly decreased inflammatory mediators including inducible nitric oxide synthase and cyclooxygenase-2. Moreover, the levels of brain-derived neurotrophic factor and its receptor, tropomycin receptor kinase B, were significantly increased in PF-treated mice. Furthermore, acetylcholinesterase activity and the ration of B-cell lymphoma 2 (Bcl-2)/Bcl-2 associated X were significantly reduced by PF in the brains of LPS-induced mice, resulting in the inhibition of cholinergic dysfunction and neuronal apoptosis. Thus, we can conclude that administration of PF to mice prevents the development of LPS-induced AD pathology through the inhibition of neuronal oxidative stress and neuroinflammation, suggesting that PF has a therapeutic potential for AD.

• 동의생리병리학회지
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• 제26권3호
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• pp.344-350
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• 2012

Previously, we showed that Dangguisoo-san (DGSS), an herbal formula that has been traditionally used for the treatment of blood stagnation, is also applicable for inflammatory lung diseases. Activation of Nrf2, an anti-inflammatory transcription factor, and suppression of NF-${\kappa}B$, a pro-inflammatory transcription factor, were suggested as an underlying mechanism. However, the constituents responsible for these activities remain unidentified. To this end, we prepared the water extracts of the 9 constituents of DGSS and tested for their effect on Nrf2 by using an Nrf2-Luciferase reporter cell line and western blot analysis. Results show that Carthamus tinctorius L.(CT), one of the 9 constituents of DGSS, strongly activated Nrf2. Similarly, when measured the effect of the 9 constituents on NF-${\kappa}B$ by using an NF-${\kappa}B$-Luciferase reporter cell line and western blotting for nuclear p65, indicative of activated NF-${\kappa}B$, most constituents were capable of suppressing NF-${\kappa}B$ in various degrees. However, CT and Cyperus rotundus L. (CR) strongly suppressed NF-${\kappa}B$ activity elicited by LPS. Of note, CT activated Nrf2 and suppressed NF-${\kappa}B$ strongly as well. Our results contributes to corroborating the anti-inflammatory effects of DGSS by identifying CT and CR as two major herbs responsible for activating Nrf2 and suppressing NF-${\kappa}B$. These results suggest that CT and CR represent some of the effects of DGSS in the regulation of inflammation.

• BMB Reports
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• 제54권12호
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• pp.614-619
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• 2021

Hepatitis B virus (HBV) infection is a major cause of hepatocellular carcinoma (HCC), which is a highly aggressive cancer. HBV X protein (HBx), one of four HBV gene products, plays pivotal roles in the development and metastasis of HCC. It has been reported that HBx induces liver cancer cell migration and reorganizes actin cytoskeleton, however the molecular basis for actin cytoskeleton reorganization remains obscure. In this study, we for the first time report that HBx promotes actin polymerization and liver cancer cell migration by regulating calcium modulated protein, calmodulin (CaM). HBx physically interacts with CaM to control the level of phosphorylated cofilin, an actin depolymerizing factor. Mechanistically, HBx interacts with CaM, liberates Hsp90 from its inhibitory partner CaM, and increases the activity of Hsp90, thus activating LIMK1/cofilin pathway. Interestingly, the interaction between HBx and CaM is calcium-dependent and requires the CaM binding motif on HBx. These results indicate that HBx modulates CaM which plays a regulatory role in Hsp90/LIMK1/cofilin pathway of actin reorganization, suggesting a new mechanism of HBV-induced HCC metastasis specifically derived by HBx.

• Journal of Microbiology
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• 제39권3호
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• pp.186-194
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• 2001

Scrub typhus, caused by Orientia tsutsugamushi infection, is clinically and histopathologically characterized by local as well as systemic inflammatory reactions, indicating that orientiae induce mechanisms that amplify the inflammatory response. To reveal underlying mechanisms of chemoattraction and activation of responding leukocytes, expression of chemokine and tumor necrosis factor alpha (TNF-$\alpha$) genes in murine peritoneal macrophages after infection with the obligate intracellular bacterium Ο.tsutsugamushi was investigated. The genes that were unregulated included macrophage inflammatory proteins l$\alpha$/$\beta$(MIP-l$\alpha$/$\beta$), MIP-2, monocyte chemoattractant protein 1(MCP-1), RANTES (regulated upon activation, normal T-cell expressed and secreted), gamma-interferon-inducible protein 10(IP-10) and TNF-$\alpha$. Peak expression of these chemokines and TNF-$\alpha$ was observed between 1 and 3 h after infection. These responses returned to or approached baseline preinfection levels 6 h after challenge. Semiquantitative reverse transcription (RT)-PCR analysis revealed dramatic Increases during infection in the steady-state levels of mRNA ceding for the inhibitory subunit of NF-kB (IkB$\alpha$), whose transcription is enhanced by binding of NF-kB within the IkB$\alpha$promoter region. Thus, Ο. tsutsugamushi appears to be a stung inducer of chemokines and TNF-$\alpha$ which may significantly contribute to inflammation and tissue damage observed in scrub typhus by attracting and activating phagocytic leukocytes.

• 한국식품영양과학회지
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• 제36권3호
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• pp.269-275
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• 2007

불가사리 추출물을 이용하여 생쥐 비장에 있는 면역세포 활성화 효과에 대해 실험한 결과, 다음과 같은 결과를 얻었다. 첫째, 별불가사리 추출물 중에서 B세포와 대식세포를 활성화시키는 성분은 아세톤처리로 추출할 수 있었다. 둘째, 이 성분은 농도 의존적으로 생쥐 비장세포의 증식반응을 유도하였으며, IL-6와 $IFN-{\gamma}$의 생산을 유도하였다. 셋째, 이 성분은 B세포의 증식을 유도하였으며, 이 때 면역글로불린 IgM과 IgG의 생산도 유도하였다. 넷째, 이 성분은 대식세포주의 일산화질소 생산을 유도하였으며, 또 $TNF-{\alpha}$, GM- CSF와 IL-6의 분비를 유도하였다. 이상의 실험 결과, 본 실험에서 사용한 별불가사리 추출물에는 B세포와 대식세포 같은 면역세포의 증식과 각종 사이토카인을 생산을 유도하여, 면역반응을 조절하는 성분이 포함되어 있는 것으로 생각된다.

• Genomics & Informatics
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• 제21권2호
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• pp.18.1-18.11
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• 2023

Immunologists have activated T cells in vitro using various stimulation methods, including phorbol myristate acetate (PMA)/ionomycin and αCD3/αCD28 agonistic antibodies. PMA stimulates protein kinase C, activating nuclear factor-κB, and ionomycin increases intracellular calcium levels, resulting in activation of nuclear factor of activated T cell. In contrast, αCD3/αCD28 agonistic antibodies activate T cells through ZAP-70, which phosphorylates linker for activation of T cell and SH2-domain-containing leukocyte protein of 76 kD. However, despite the use of these two different in vitro T cell activation methods for decades, the differential effects of chemical-based and antibody-based activation of primary human T cells have not yet been comprehensively described. Using single-cell RNA sequencing (scRNA-seq) technologies to analyze gene expression unbiasedly at the single-cell level, we compared the transcriptomic profiles of the non-physiological and physiological activation methods on human peripheral blood mononuclear cell-derived T cells from four independent donors. Remarkable transcriptomic differences in the expression of cytokines and their respective receptors were identified. We also identified activated CD4 T cell subsets (CD55⁺) enriched specifically by PMA/ionomycin activation. We believe this activated human T cell transcriptome atlas derived from two different activation methods will enhance our understanding, highlight the optimal use of these two in vitro T cell activation assays, and be applied as a reference standard when analyzing activated specific disease-originated T cells through scRNA-seq.

• Biomolecules & Therapeutics
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• 제25권5호
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• pp.504-510
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• 2017

Inhibitor of nuclear factor kappa-B kinase beta ($IKK{\beta}$) plays a critical role in cell proliferation and inflammation in various cells by activating $NF-{\kappa}B$ signaling. However, the interrelationship between peroxisome proliferator-activated receptor ${\alpha}$ ($PPAR{\alpha}$) and $IKK{\beta}$ in cell proliferation is not clear. In this study, we investigated the possible role of $PPAR{\alpha}$ in the hepatic cell death in the absence of $IKK{\beta}$ gene using liver-specific Ikkb-null ($Ikkb^{F/F-AlbCre}$) mice. To examine the function of $PPAR{\alpha}$ activation in hepatic cell death, wild-type ($Ikkb^{F/F}$) and $Ikkb^{F/F-AlbCre}$ mice were treated with $PPAR{\alpha}$ agonist Wy-14,643 (0.1% w/w chow diet) for two weeks. As a result of Wy-14,643 treatment, apoptotic markers including caspase-3 cleavage, poly (ADP-ribose) polymerase (PARP) cleavage and TUNEL-positive staining were significantly decreased in the $Ikkb^{F/F-AlbCre}$ mice. Surprisingly, Wy-14,643 increased the phosphorylation of p65 and STAT3 in both Ikkb and $Ikkb^{F/F-AlbCre}$ mice. Furthermore, BrdU-positive cells were significantly increased in both groups after treatment with Wy-14,643. Our results suggested that $IKK{\beta}-derived$ hepatic apoptosis could be altered by $PPAR{\alpha}$ activation in conjunction with activation of $NF-{\kappa}B$ and STAT3 signaling.

• Journal of Ginseng Research
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• 제48권4호
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• pp.384-394
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• 2024

Background: Herpes simplex virus type 1 (HSV-1), known to latently infect the host's trigeminal ganglion, can lead to severe herpes encephalitis or asymptomatic infection, potentially contributing to neurodegenerative diseases like Alzheimer's. The virus generates reactive oxygen species (ROS) that significantly impact viral replication and induce chronic inflammation through NF-κB activation. Nuclear factor E2-related factor 2 (Nrf2), an oxidative stress regulator, can prevent and treat HSV-1 infection by activating the passive defense response in the early stages of infection. Methods and results: Our study investigated the antiviral effects of ginsenoside Rg5, an Nrf2 activator, on HSV-1 replication and several host cell signaling pathways. We found that HSV-1 infection inhibited Nrf2 activity in host cells, induced ROS/NF-κB signaling, and triggered inflammatory cytokines. However, treatment with ginsenoside Rg5 inhibited ROS/NF-κB signaling and reduced inflammatory cytokines through NRF2 induction. Interestingly, the Nrf2 inhibitor ML385 suppressed the expression of NAD(P)H quinone oxidoreductase 1(NQO1) and enhanced the expression of KEAP1 in HSV-1 infected cells. This led to the reversal of VP16 expression inhibition, a protein factor associated with HSV-1 infection, thereby promoting HSV-1 replication. Conclusion: These findings suggest for the first time that ginsenoside Rg5 may serve as an antiviral against HSV-1 infection and could be a novel therapeutic agent for HSV-1-induced neuroinflammation.

• 한국식품영양과학회지
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• 제44권7호
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• pp.1079-1083
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• 2015

본 연구는 양조과정의 부산물인 주박으로부터 분리한 다당류(JPS)가 초기 면역반응에 중추적인 역할을 수행하는 대식세포에서 활성화를 유도하는지에 관한 여부를 알아보기 위해서 수행되었다. 주박에서 분리한 다당류를 마우스 유래 대식세포인 RAW264.7 cell에 처리하였을 때 대식세포의 활성화의 지표인 NO와 cytokine(IL-6, TNF-${\alpha}$)의 분비가 증가되었다. 또한 이러한 NO와 cytokine의 증가의 원인에 관한 면역기전에 관하여 알아본 결과 JPS의 처리는 MAPKs(ERK, JNK, p-38)의 인산화를 촉진시켜 NF-${\kappa}B$의 활성을 유도하여 면역세포의 활성인자들의 분비를 촉진시킨 것으로 관찰되었다.