• Biomolecules & Therapeutics
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• 제17권2호
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• pp.144-150
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• 2009

Reactive oxygen species play a role in signal transduction and in many human diseases. B-cell activating factor (BAFF) plays a role for mature B cell generation and maintenance and for the incidence of autoimmune diseases. We previously reported that BAFF expression was induced by ROS. In this study, we investigated whether ROS-induced BAFF expression was affected by toll-like receptor (TLR) 4 or myeloid differentiation primary response gene (MyD) 88. BAFF expression was increased by serum deprivation that is an experimental modification to produce ROS. In contrast, TLR4 and MyD88 were decreased by serum deprivation. Although ROS production was decreased in TLR4-nonfunctional or MyD88-deficient splenocytes as compared to that in control mice, serum deprivation increased ROS production and augmented BAFF expression in both cells. $50{\mu}M\;H_2O_2$ also increased BAFF expression in TLR4-deficient or MyD88-deficient splenocytes. Collectively, results show that BAFF expression may be mediated by TLR4 or MyD88-independent manner and TLR4 or MyD88 may not be required in BAFF expression.

• IMMUNE NETWORK
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• 제15권3호
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• pp.125-134
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• 2015

Acute graft-versus-host-disease (GVHD) is characterized by selective damage to the liver, the skin, and the gastrointestinal tract. Following allogeneic hematopoietic stem cell transplantation, donor bone marrow (BM) cells repopulate the immune system of the recipient. We previously demonstrated that the acute intestinal GVHD (iGVHD) mortality rate was higher in MyD88-deficient BM recipients than that in the control BM recipients. In the present study, the role of MyD88 (expressed by donor BM) in the pathophysiology of hepatic GVHD (hGVHD) was examined. Unlike iGVHD, transplantation with MyD88-deficient T-cell depleted (TCD) BM attenuated hGVHD severity and was associated with low infiltration of T cells into the liver of the recipients. Moreover, GVHD hosts, transplanted with MyD88-deficient TCD BM, exhibited markedly reduced expansion of $CD11b^+Gr-1^+$ myeloidderived suppressor cells (MDSC) in the liver. Adoptive injection of the MDSC from wild type mice, but not MyD88-deficient mice, enhanced hepatic T cell infiltration in the MyD88-deficient TCD BM recipients. Pre-treatment of BM donors with LPS increased MDSC levels in the liver of allogeneic wild type BM recipients. In conclusion, hGVHD and iGVHD may occur through various mechanisms based on the presence of MyD88 in the non-T cell compartment of the allograft.

• Nutrition Research and Practice
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• 제8권5호
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• pp.516-520
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• 2014

BACKGROUND/OBJECTIVES: Carnosic acid (CA), found in rosemary (Rosemarinus officinalis) leaves, is known to exhibit anti-obesity and anti-inflammatory activities. However, whether its anti-inflammatory potency can contribute to the amelioration of obesity has not been elucidated. The aim of the current study was to investigate the effect of CA on Toll-like receptor 4 (TLR4) pathways in the presence of lipopolysaccharide (LPS) in 3T3-L1 adipocytes. MATERIALS/METHODS: 3T3-L1 adipocytes were treated with CA ($0-20{\mu}M$) for 1 h, followed by treatment with LPS for 30 min; mRNA expression of adipokines and protein expression of TLR4-related molecules were then measured. RESULTS: LPS-stimulated 3T3-L1 adipocytes showed elevated mRNA expression of tumor necrosis factor (TNF)-${\alpha}$, interleukin-6, and monocyte chemoattractant protein-1, and CA significantly inhibited the expression of these adipokine genes. LPS-induced up regulation of TLR4, myeloid differentiation factor 88, TNF receptor-associated factor 6, and nuclear factor-${\kappa}B$, as well as phosphorylated extracellular receptor-activated kinase were also suppressed by pre-treatment of 3T3-L1 adipocytes with CA. CONCLUSIONS: Results of this study suggest that CA directly inhibits TLR4-MyD88-dependent signaling pathways and decreases the inflammatory response in adipocytes.

• 생명과학회지
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• 제21권1호
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• pp.36-43
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• 2011

Glycate화된 단백질이 혈관질환의 발생에 관여하는지 알아보기 위하여 glycated albumin (GA)이 혈관평활근 세포에서 인터루킨-6 발현에 영향을 주는지 조사하고 또한 그 기전을 구명하였다. GA에 노출된 혈관평활근세포에서 인터루킨-6 transcript가 증가하고, 인터루킨-6 단백질의 분비가 증가하고, 또한 인터루킨-6 유전자의 promoter가 활성화되었다. GA에 의한 인터루킨-6 유전자의 promoter 활성화는 dominant negative 형태의 Toll-like receptor (TLR)-4와 myeloid differentiation factor 88 (Myd88)에 의하여 크게 감소되었지만, dominant negative 형태의 TLR-2와 TIR-domain-containing adapter-inducing interferon-$\beta$ (TRIF)의 영향을 받지 않았다. 그리고 Extrcellular signal-related kinase (ERK) 억제 물질들은 GA에 의한 인터루킨-6의 분비 및 인터루킨-6 유전자 promoter 활성화를 억제하였다. 그리고 인터루킨-6 유전자의 promoter의 NF-${\kappa}B$-binding sequence에 변이는 GA에 의한 인터루킨-6 유전자의 promoter 활성화 억제하였다. 이러한 결과는 혈관평활근세포에서 GA에 의한 인터루킨-6 유전자 활성화에 TLR-4와 ERK 및 NF-${\kappa}B$가 관여함을 의미한다.

• 한국식생활문화학회지
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• 제33권4호
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• pp.337-344
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• 2018

Germinated brown rice (GBR, Orysa sartiva L.) has been reported to have anti-obesity and anti-inflammatory effects. However, the mechanisms underlying these effects in adipocytes are not fully understood. Therefore, this study was conducted to explore the anti-inflammatory mechanisms of GBR on lipopolysaccharide (LPS)-stimulated 3T3-L1 adipocytes. 3T3-L1 adipocytes were pretreated with GBR extracts (0-20 mg/mL) 1 h before LPS stimulation. The mRNA expression of adipokines and Toll-like receptor 4 (TLR4) were measured by RT-PCR. The protein expressions of TLR4-related molecules were detected by western blotting and nuclear factor-${\kappa}B$ ($NF-{\kappa}B$) activation was measured. Our results showed that GBR extract dose-dependently inhibited mRNA expression of LPS-induced tumor necrosis factor-${\alpha}$ ($TNF-{\alpha}$), interleukin-6 (IL-6), and monocyte chemoattractant protein-1 (MCP-1). GBR extract was found to inhibit LPS-induced mRNA expression of TLR4 and protein expression of both myeloid differentiation factor 88 (MyD88) and TNF receptor-associated factor 6 (TRAF6). Furthermore, GBR extract significantly inhibited extracellular receptor-activated kinase (ERK) phosphorylation and $NF-{\kappa}B$ activation. These results suggest that GBR extract has the anti-inflammatory effects on LPS-induced inflammation via inhibition of TLR4 signaling, includingthe ERK and $NF-{\kappa}B$ signaling pathways, in adipocytes.

• Asian Pacific Journal of Cancer Prevention
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• 제13권6호
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• pp.2807-2812
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• 2012

The purpose of this study was to examine the effect of a Toll-like receptor 5 (TLR5) agonist, CBLB502, on the growth and radiosensitivity of A549 lung cancer cells in vivo. Expression of myeloid differentiation factor 88 (MyD88) or TLR5 was stably knocked down in human lung cancer cells (A549) using lentivirus expressing short hairpin RNA targeting human MyD88 or TLR5. Lack of MyD88 or TLR5 expression enhanced tumor growth in mouse xenografts of A549 lung cancer cells. CBLB502 inhibited the growth of A549 lung cancer cells, not A549-MyD88-KD cells in vivo in the murine xenograft model. Our results showed that the inhibition of A549 by CBLB502 in vivo was realized through regulating the expression of neutrophil recruiting cytokines and neutrophil infiltration. Finally, we found that activation of TLR5 signaling did not affect the radiosensitivity of tumors in vivo.

• 생명과학회지
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• 제33권6호
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• pp.463-470
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• 2023

Desmarestia tabacoides Okamura는 전 세계적으로 널리 분포하는 갈조류 중 하나이다. 몇몇 산말류의 항종양, 멜라닌 생성 억제 및 광보호 활성에 대한 연구는 있었으나 D. tabacoides Okamura의 항염증 기전에 대해서는 보고되지 않아 본 연구에서는 LPS (lipopolysaccharide)로 자극된 RAW 264.7 세포에서 D. tabacoides Okamura 에탄올 추출물(DTEE)의 항염증 기전을 inducible nitric oxide synthase (iNOS)와 cyclooxygenase (COX)-2의 발현 및 이들의 상위신호전달물질인 nuclear factor (NF)-κB, mitogen-activated protein kinase (MAPK) 그리고 phosphoinositide-3-kinase (PI3K)/Akt의 인산화 조절 정도를 통해 분석하였다. DTEE의 처리는 세포 독성 없이 LPS로 유도된 NO와 prostaglandin (PG) E₂의 생성과 이들의 생성 효소인 iNOS 및 COX-2의 발현을 유의하게 억제하였다. 그리고 LPS에 의해 활성화된 NF-κB 및 상위 신호 전달 물질인 extracellular signal-regulated kinase (ERK), c-Jun NH₂-terminal kinase (JNK) 및 p38은 DTEE 처리에 의해 유의적으로 억제되었다. DTEE의 처리는 RAW 264.7 세포에서 LPS에 의해 활성화되는 adaptor molecule인 Toll-like receptor (TLR) 4 및 myeloid differentiation primary response (MyD) 88 또한 유의적으로 억제하였다. 이 결과를 통해 DTEE는 LPS에 의해 유도된 TLR4와 NF-κB 및 MAPK의 활성을 억제함으로써 염증 매개인자의 발현을 조절하였고, 이는 DTEE가 염증을 완화할 수 있는 기능성 식품의 소재로써 유용하게 사용될 수 있음을 시사한다.

• 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.

• IMMUNE NETWORK
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• 제21권4호
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• pp.27.1-27.12
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• 2021

Respiratory syncytial virus (RSV) is the leading cause of respiratory viral infection in infants and children. However, little is known about the contribution of monocytes to antiviral responses against RSV infection. We identified the IFN-β production of monocytes using IFN-β/YFP reporter mice. The kinetic analysis of IFN-β-producing cells in in vivo RSV-infected lung cells indicated that monocytes are recruited to the inflamed lung during the early phase of infection. These cells produced IFN-β via the myeloid differentiation factor 88-mediated pathway, rather than the TLR7- or mitochondrial antiviral signaling protein-mediated pathway. In addition, monocyte-ablated mice exhibited decreased numbers of IFN-γ-producing and RSV Ag-specific CD8⁺ T cells. Collectively, these data indicate that monocytes play pivotal roles in cytotoxic T-cell responses and act as type I IFN producers during RSV infection.

• Journal of Veterinary Science
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• 제24권1호
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• pp.2.1-2.14
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• 2023

Background: Hypothermia is a crucial environmental factor that elevates the risk of cardiovascular disease, but the underlying effect is unclear. Objectives: This study examined the role of cold stress (CS) in cardiac injury and its underlying mechanisms. Methods: In this study, a chronic CS-induced myocardial injury model was used; mice were subjected to chronic CS (4℃) for three hours per day for three weeks. Results: CS could result in myocardial injury by inducing the levels of heat shock proteins 70 (HSP70), enhancing the generation of creatine phosphokinase-isoenzyme (CKMB) and malondialdehyde (MDA), increasing the contents of tumor necrosis factor-α (TNF-α), high mobility group box 1 (HMGB1) interleukin1b (IL-1β), IL-18, IL-6, and triggering the depletion of superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH). Multiple signaling pathways were activated by cold exposure, including pyroptosis-associated NOD-like receptor 3 (NLRP3)-regulated caspase-1-dependent/Gasdermin D (GSDMD), inflammation-related toll-like receptor 4 (TLR4)/myeloid differentiation factor 88 (MyD88)-mediated nuclear factor kappa B (NF-κB), and mitogen-activated protein kinase (MAPK), as well as oxidative stressinvolved thioredoxin-1/thioredoxin-interacting protein (Txnip) signaling pathways, which play a pivotal role in myocardial injury resulting from hypothermia. Conclusions: These findings provide new insights into the increased risk of cardiovascular disease at extremely low temperatures.