• Molecules and Cells
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• 제38권1호
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• pp.58-64
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• 2015

Activating transcription factor-3 (ATF3) acts as a negative regulator of cytokine production during Gram-negative bacterial infection. A recent study reported that ATF3 provides protection from Streptococcus pneumoniae infection by activating cytokines. However, the mechanism by which S. pneumoniae induces ATF3 after infection is still unknown. In this study, we show that ATF3 was upregulated via Toll-like receptor (TLR) pathways in response to S. pneumoniae infection in vitro. Induction was mediated by TLR4 and TLR2, which are in the TLR family. The expression of ATF3 was induced by pneumolysin (PLY), a potent pneumococcal virulence factor, via the TLR4 pathway. Furthermore, ATF3 induction is mediated by p38 mitogen-activated protein kinase (MAPK) and c-Jun N-terminal kinase (JNK). Thus, this study reveals a potential role of PLY in modulating ATF3 expression, which is required for the regulation of immune responses against pneumococcal infection in macrophages.

• 생명과학회지
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• 제21권9호
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• pp.1259-1265
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• 2011

본 연구의 목적은 일회성 유산소 운동이 TLR4, IL-6, TNF-${\alpha}$, SOCS-3 유전자 발현에 미치는 영향을 쥐의 골격근에서 살펴보는데 있었다. 또한 이러한 일회성 운동의 영향이 근섬유 형태 특이적으로 나타나는 지에 대한 연구도 수행되었다. 실험은 Balb/c 수컷 쥐(male: 7주령, 몸무게 $22.78{\pm}0.27g$) 13마리 대상으로 하였으며, 대조군과 운동군으로 무선배정되었다. 운동은 일회성으로 지칠 때까지 트레드밀 운동(경사도 $10^{\circ}$, speed 17 cm/sec 10 min, 33 cm/sec 10 min, 50 cm/sec)을 실시하였으며, 운동 후 24시간이 지난 시점에서 가자미근과 족저근을 적출하였다. 가자미근과 족저근의 TLR4, IL-6, TNF-${\alpha}$, SOCS-3 mRNA 수준 변화는 real-time PCR을 이용하여 측정하였다. 일회성 유산소 트레드밀 운동은 가자미근에서 TLR4 mRNA 발현을 유의하게 증가시켰지만, 족저근의 TLR4 mRNA 발현에는 유의한 영향을 미치지 않았다. 또한 IL-6, TNF-${\alpha}$, SOCS-3 mRNA 발현은 가자미근에서 일회성트레드밀 운동에 의해 유의하게 증가되었다. 하지만 족저근에서 이들 유전자의 mRNA 발현은 일회성 운동에 의해 영향을 받지 않았다. 결론적으로 TLR4, IL-6, TNF-${\alpha}$, SOCS-3와 같은 면역관련 유전자의 발현 수준은 일회성트레드밀 운동에 의해 근섬유 형태 특이적으로 조절됨을 알 수 있었다.

• BMB Reports
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• 제47권7호
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• pp.361-368
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• 2014

Lipid components in biological membranes are essential for maintaining cellular function. Phosphoinositides, the phosphorylated derivatives of phosphatidylinositol (PI), regulate many critical cell processes involving membrane signaling, trafficking, and reorganization. Multiple metabolic pathways including phosphoinositide kinases and phosphatases and phospholipases tightly control spatio-temporal concentration of membrane phosphoinositides. Metabolizing enzymes responsible for PI 4,5-bisphosphate (PI(4,5)P2) production or degradation play a regulatory role in Toll-like receptor (TLR) signaling and trafficking. These enzymes include PI 4-phosphate 5-kinase, phosphatase and tensin homolog, PI 3-kinase, and phospholipase C. PI(4,5)P2 mediates the interaction with target cytosolic proteins to induce their membrane translocation, regulate vesicular trafficking, and serve as a precursor for other signaling lipids. TLR activation is important for the innate immune response and is implicated in diverse pathophysiological disorders. TLR signaling is controlled by specific interactions with distinct signaling and sorting adaptors. Importantly, TLR signaling machinery is differentially formed depending on a specific membrane compartment during signaling cascades. Although detailed mechanisms remain to be fully clarified, phosphoinositide metabolism is promising for a better understanding of such spatio-temporal regulation of TLR signaling and trafficking.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2022년도 추계학술대회
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• pp.93-93
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• 2022

Hovenia dulcis, one of the traditional medicinal plants, is currently being used as a functional ingredient for the development of health functional foods that protects the liver from alcohol damage in Korea. A variety of pharmacological effects of Hovenia dulcis have been reported so far, but studies on immune-enhancing activity are insufficient. Thus, in this study, we report that Hovenia dulcis branches (HDB) induce the activation of macrophages. HDB increased the production of immunostimulatory factors and phagocytosis in RAW264.7 cells. TLR4 inhibition blocked HDB-mediated production of immunostimulatory factors. In addition, the JNK inhibition reduced the HDB-mediated production of immunostimulatory factors, and the HDB-mediated JNK activation was blocked by the TLR4 inhibition. HDB increased the level of LC3-II and p62/SQSTM1. TLR4 inhibition blocked HDB-mediated increase in the level of LC3-II and p62/SQSTM1. These findings indicate that HDB may induce TLR4/JNK-dependent macrophage activation and TLR4-dependent macrophage autophagy.

• Biomolecules & Therapeutics
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• 제24권4호
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• pp.387-394
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• 2016

Sepsis, a serious clinical problem, is characterized by a systemic inflammatory response to infection and leads to organ failure. Toll-like receptor (TLR) signaling is intimately implicated in hyper-inflammatory responses and tissue injury during sepsis. Histone deacetylase (HDAC) inhibitors have been reported to exhibit anti-inflammatory properties. The aim of this study was to investigate the hepatoprotective mechanisms of trichostatin A (TSA), a HDAC inhibitor, associated with TLR signaling pathway during sepsis. The anti-inflammatory properties of TSA were assayed in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. Polymicrobial sepsis was induced in mice by cecal ligation and puncture (CLP), a clinically relevant model of sepsis. The mice were intraperitoneally received TSA (1, 2 or 5 mg/kg) 30 min before CLP. The serum and liver samples were collected 6 and 24-h after CLP. TSA inhibited the increased production of tumor necrosis factor (TNF)-${\alpha}$ and interleukin (IL)-6 in LPS-stimulated RAW264.7 cells. TSA improved sepsis-induced mortality, attenuated liver injury and decreased serum TNF-${\alpha}$ and IL-6 levels. CLP increased the levels of TLR4, TLR2 and myeloid differentiation primary response protein 88 (MyD88) protein expression and association of MyD88 with TLR4 and TLR2, which were attenuated by TSA. CLP increased nuclear translocation of nuclear factor kappa B and decreased cytosolic inhibitor of kappa B ($I{\kappa}B$) protein expression, which were attenuated by TSA. Moreover, CLP decreased acetylation of $I{\kappa}B$ kinase (IKK) and increased association of IKK with $I{\kappa}B$ and TSA attenuated these alterations. Our findings suggest that TSA attenuates liver injury by inhibiting TLR-mediated inflammatory response during sepsis.

• 한국자원식물학회지
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• 제34권3호
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• pp.203-215
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• 2021

Bok choy is one of Brassica vegetables widely consumed worldwide. Brassica vegetables have been reported to exert various pharmacological activities such as antioxidant, anti-cancer and cardioprotective activity. However, studies on immunostimulatory activity of bok choy sprout have not been conducted properly. Thus, in this study, we investigated in vitro immunostimulatory activity of bok choy sprout extract (BCS) using mouse macrophage RAW264.7 cells. Our results showed that BCS increased the production of immunomodulators such as NO, iNOS, IL-1β, IL-6, IL-12, TNF-α and MCP-1, and phagocytic activity in RAW264.7 cells. BCS activated MAPK, NF-κB and PI3K/AKT signaling pathways. However, BCS-mediated production of immunomodulators was dependent on JNK, NF-κB and PI3K/AKT signaling pathways. the mRNA expression of TLR2 were significantly increased by BCS, TLR2 inhibition by anti-TLR2 dramatically suppressed the production of immunomodulators by BCS. In addition, TLR2 inhibition by anti-TLR2 significantly reduced BCS-mediated phosphorylation level of AKT, JNK and NF-κB. From these results, BCS may have immunostimulatory activity via TLR2-MAPK, NF-κB and PI3K/AKT signaling pathways. Therefore, BCS expected to be used as a potential immune-enhancing agent.

• The Korean Journal of Physiology and Pharmacology
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• 제22권2호
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• pp.145-153
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• 2018

The subgranular zone (SGZ) of hippocampal dentate gyrus (HDG) is a primary site of adult neurogenesis. Toll-like receptors (TLRs), are involved in neural system development of Drosophila and innate immune response of mammals. TLR2 is expressed abundantly in neurogenic niches such as adult mammalian hippocampus. It regulates adult hippocampal neurogenesis. However, the role of TLR2 in adult neurogenesis is not well studied in global or focal cerebral ischemia. Therefore, this study aimed to investigate the role of TLR2 in adult neurogenesis after photochemically induced cerebral ischemia. At 7 days after photothrombotic ischemic injury, the number of bromodeoxyuridine (BrdU)-positive cells was increased in both TLR2 knock-out (KO) mice and wild-type (WT) mice. However, the increment rate of BrdU-positive cells was lower in TLR2 KO mice compared to that in WT mice. The number of doublecortin (DCX) and neuronal nuclei (NeuN)-positive cells in HDG was decreased after photothrombotic ischemia in TLR2 KO mice compared to that in WT mice. The survival rate of cells in HDG was decreased in TLR2 KO mice compared to that in WT mice. In contrast, the number of cleaved-caspase 3 (apoptotic marker) and the number of GFAP (glia marker)/BrdU double-positive cells in TLR2 KO mice were higher than that in WT mice. These results suggest that TLR2 can promote adult neurogenesis from neural stem cell of hippocampal dentate gyrus through increasing proliferation, differentiation, and survival from neural stem cells after ischemic injury of the brain.

• 한국자원식물학회지
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• 제34권6호
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• pp.536-541
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• 2021

In this study, we investigated whether Hibiscus manihot flowers (HMF) exhibits immunostimulatory activity in RAW264.7 cells. HMF increased the production of immunostimulatory factors such as NO, iNOS, IL-1β and TNF-α in RAW264.7 cells. TLR2 and TLR4 blocked HMF-mediated production of immunostimulatory factors in RAW264.7 cells. In addition, the inhibition of MAPK signaling pathway reduced HMF-mediated production of immunostimulatory factors. From these results, HMF is thought to promote the production of immunostimulatory factors through activating TLR2/4/MAPK signaling in macrophages. It is believed that HMF can be developed as an agent related to immune enhancement in the future.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2010년도 춘계학술발표대회
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• pp.41.1-41.1
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• 2010

생체재료란 손상된 생체조직의 기능을 가능한 한 정상에 가까운 상태로 회복시킬 때 이용되는 재료이다. 생체재료는 보건 의료 분야 중 치료, 재활 및 예방의 수단으로 생체에 적용되기 때문에 인간 수명연장 및 사고, 질병의 증가 등에 따라 그 중요성이 점점 증가되고 있는 추세이다. 그럼에도 불구하고, 생체재료 이식에 따른 면역기전에 대해서는 명확하게 밝혀지지 않고 있다. 따라서 본 연구에서는 미생물의 특이 구조를 인식하여 염증반응을 유도하는 TLR (Toll like receptor)을 통한 면역학적 기전을 생체재료 이식시 나타나는 면역반응에 적용하고자 macrophage cell line인 RAW264.7을 이용하여 확인하였다. 생체재료(칼슘-인산계 뼈이식제, PCL microphere)의 특성은 electron microscope(SEM, TEM)을 통하여 관찰하였고 RAW264.7에 의한 세포 독성실험 (MTT와 LDH assay) 결과 세포독성은 없는 것으로 확인되었다. 생체재료가 TLR pathway에 미치는 영향을 Western blotting과 RT-PCR을 이용하여 확인하였으며, 면역반응 시 유도되는 cytokine을 RT-PCR과 ELISA를 이용하여 확인하였다.

• Journal of Nutrition and Health
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• 제49권4호
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• pp.241-246
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• 2016

Purpose: Aloe-emodin (AE), an ingredient of aloe, is known to exhibit anti-inflammatory activities. However, little is known about the underlying molecular mechanisms of its inflammatory modulatory activity in vitro. In the present study, we investigated the anti-inflammatory potential of AE using $Pam_3CSK_4$-stimulated macrophages. Methods: RAW 264.7 macrophages were treated with AE (0~20 mM) for 1 h, followed by treatment with $Pam_3CSK_4$ for 1 h. After incubation, mRNA expression levels of cytokines were measured. The effect of AE on TLR2-related molecules was also investigated in $Pam_3CSK_4$-stimulated RAW 264.7 macrophages. Results: AE attenuated $Pam_3CSK_4$-stimulated expression of proinflammatory cytokines, including tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$), interleukin-6 (IL-6), and interleukin-$1{\beta}$ ($IL-1{\beta}$) in RAW 264.7 macrophages. Two concentrations of AE ($10{\mu}M$ and $20{\mu}M$) effectively reduced mRNA expression of TLR2 by 41.18% and 54.43%, respectively, compared to that in control cells (p < 0.05). AE also decreased nuclear factor-kappa B ($NF-{\kappa}B$) activation and mitogen-activated protein kinase (MAPK) phosphorylation. Phosphorylation levels of ERK1/2, p38, and JNK were markedly reduced by $20{\mu}M$ AE. In particular, AE decreased phosphorylation of ERK in a dose-dependent manner in $Pam_3CSK_4$-stimulated RAW 264.7 macrophages. Conclusion: Our data indicate that AE exerts its anti-inflammatory effect by suppressing TLR2-mediated activation of $NF-{\kappa}B$ and MAPK signaling pathways in macrophages.