• IMMUNE NETWORK
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• 제22권2호
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• pp.20.1-20.9
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• 2022

Despite the high prevalence of chronic dermatitis and the accompanied intractable itch, therapeutics that specifically target itching have low efficacy. Increasing evidence suggests that TLRs contribute to immune activation and neural sensitization; however, their roles in chronic itch remain elusive. Here, we show that the RBL-2H3 mast cell line expresses TLR4 and that treatment with a TLR4 antagonist opposes the LPS dependent increase in mRNA levels of Th2 and innate cytokines. The pathological role of TLR4 activation in itching was studied in neonate rats that developed chronic itch due to neuronal damage after receiving subcutaneous capsaicin injections. Treatment with a TLR4 antagonist protected these rats with chronic itch against scratching behavior and chronic dermatitis. TLR4 antagonist treatment also restored the density of cutaneous nerve fibers and inhibited the histopathological changes that are associated with mast cell activation after capsaicin injection. Additionally, the expression of IL-1β, IL-4, IL-5, IL-10, and IL-13 mRNA in the lesional skin decreased after TLR4 antagonist treatment. Based on these data, we propose that inhibiting TLR4 alleviated itch in a rat model of chronic relapsing itch, and the reduction in the itch was associated with TLR4 signaling in mast cells and nerve fibers.

• Asian-Australasian Journal of Animal Sciences
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• 제24권7호
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• pp.1019-1025
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• 2011

Toll-like receptors (TLRs) play an important role in the recognition of invading pathogens and the modulation of innate immune responses in mammals. The TLR4 and TLR7 are well known to recognize the bacterial lipopolysaccharide (LPS) and single stranded (ssRNA) ligands, respectively and play important role in host defense against Gram-negative bacteria and ssRNA viruses. In the present study, coding exon fragments of these two TLRs were identified, cloned, sequenced and analyzed in terms of insertion-deletion polymorphism, within bovine TLRs 4 and 7, thereby facilitating future TLR signaling and association studies relevant to bovine innate immunity. Comparative sequence analysis of TLR 4 exons revealed that this gene is more variable, particularly the coding frame (E3P1), while other parts showed percent identity of 95.7% to 100% at nucleotide and amino acid level, respectivley with other Bos indicus and Bos taurus breeds from different parts of the world. In comparison to TLR4, sequence analysis of TLR7 showed more conservation among different B. indicus and B. taurus breeds, except single point mutation at 324 nucleotide position (AAA to AAM) altering a single amino acid at 108 position (K to X). Percent identity of TLR7 sequences (all 3 exons) was between 99.2% to 100% at nucleotide and amino acid level, when compared with available sequence database of B. indicus and B. taurus. Simple Modular Architecture Research Tool (SMART) analysis showed variations in the exon fragments located in the Leucine Rich Repeat (LRR) region, which is responsible for binding with the microbial associated molecular patterns and further, downstream signaling to initiate anti-microbial response. Considering importance of TLR polymorphism in terms of innate immunity, further research is warranted.

• Journal of Microbiology and Biotechnology
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• 제32권10호
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• pp.1344-1354
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• 2022

Laryngeal cancer is one of the highest incidence, most prevalently diagnosed head and neck cancers, making it critically necessary to probe effective targets for laryngeal cancer treatment. Here, real-time quantitative reverse transcription PCR (qRT-PCR) and western blot analysis were used to detect gene expression levels in laryngeal cancer cell lines. Fluorescence in situ hybridization (FISH) and subcellular fractionation assays were used to detect the subcellular location. Functional assays encompassing Cell Counting Kit-8 (CCK-8), 5-ethynyl-2'-deoxyuridine (EdU), transwell and wound healing assays were performed to examine the effects of target genes on cell proliferation and migration in laryngeal cancer. The in vivo effects were proved by animal experiments. RNA-binding protein immunoprecipitation (RIP), RNA pulldown and luciferase reporter assays were used to investigate the underlying regulatory mechanisms. The results showed that KIF26B antisense RNA 1 (KIF26B-AS1) propels cell proliferation and migration in laryngeal cancer and regulates the toll-like receptor 4 (TLR4) signaling pathway. KIF26B-AS1 also recruits FUS to stabilize TLR4 mRNA, consequently activating the TLR4 signaling pathway. Furthermore, KIF26B-AS1 plays an oncogenic role in laryngeal cancer via upregulating TLR4 expression as well as the FUS/TLR4 pathway axis, findings which offer novel insight for targeted therapies in the treatment of laryngeal cancer patients.

• 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.

• International Journal of Oral Biology
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• 제44권4호
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• pp.160-164
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• 2019

Porphyromonas gingivalis (Pg), Aggregatibacter actinomycetemcomitans (Aa), Tannerella forsythia (Tf), Prevotella intermedia (Pi), and Fusobacterium nucleatum (Fn) are major periodontal pathogens. Lipopolysaccharides (LPSs) from periodontal bacteria play an important role in periodontal pathogenesis by stimulating host cells to produce inflammatory cytokines. In this study, highly pure LPSs from the five major periodontopathogens were prepared, and their monocyte chemoattractant protein-1 (MCP-1) and tumor necrosis factor-α (TNF-α)-inducing activities were compared in human umbilical vein endothelial cells (HUVECs) and THP-1 macrophagic cells, respectively. In HUVECs, LPSs from Aa and Fn were potent stimulators for MCP-1 induction; however, LPSs from Pg, Pi, and Tf were much weaker MCP-1 inducers. In THP-1 cells, LPSs from Pg, Aa, and Fn were relatively strong inducers of TNF-α, whereas LPSs from Pi and Tf produced little activity. The Toll-like receptor (TLR)2/TLR4 dependency of various LPSs was also determined by measuring NF-κB reporter activity in TLR2- or TLR4-expressing 293 cells. LPSs from Aa, Fn, and Tf stimulated only TLR4; however, LPSs from Pg and Pi stimulated both TLR2 and TLR4. These results suggest that LPSs from major periodontal bacteria differ considerably in their cell-stimulating activity.

• 한국임상수의학회지
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• 제26권6호
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• pp.520-523
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• 2009

본 연구는 말의 정상안과 재발성 포도막염이 있는 안구에서의 TLR-2, -4, -9 mRNA 발현의 정량적 차이를 비교하기 위해 수행되었다. 정상 및 재발성 포도막염이 있는 말 각 6두 에서 안구를 적출하여 모양체, 홍채, 망막 및 맥락막을 수집하였다. Real-time PCR assay 통해 정상안과 재발성 포도막염이 있는 안구에서의 TLR-2, -4, -9의 mRNA 발현 차이를 정량적으로 비교하였다. 말의 재발성 포도막염 시에는 모양체, 홍채에서 정상인 경우에 비해 4-12 배의 TLR-2 와 TLR-9 mRNA 발현증가를 보였으며, 맥락막 및 망막에서는 2-6 배의 TLR-2, -4, -9 mRNA 발현 증가를 보였다. 본 연구 결과는 Toll-like receptor 2, -4, -9이 말의 재발성 포도막염의 병리기전에 영향을 미치고 있음을 시사한다. 하지만 재발성 포도막염 시의 Toll-like receptor 2, -4, -9의 구체적 역할을 밝히기 위해서는 다양한 후속 연구가 요구된다.

• Reproductive and Developmental Biology
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• 제39권4호
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• pp.105-115
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• 2015

Toll-like receptor 7 (TLR7) is critical for the triggering of innate immune response by recognizing the conserved molecular patterns of single-stranded RNA (ssRNA) viruses and mediated antigenic adaptive immunity. To understand how TLR7 distinguish pathogen-derived molecular patterns from the host self, it is essential to be able to identify TLR7 receptor interaction interfaces, such as active sites or R848-agonist binding sites. The functional interfaces of TLR7 can serve as targets for structure-based drug design in studying the TLR7 receptor's structure-function relationship. In contrast to mammalian TLR7, chicken TLR7 (chTLR7) is unknown for its important biological function. Therefore, it has been targeted to mediate contrasting evolutionary patterns of positive selection into non-synonymous SNPs across eleven species using TLR7 conservation patterns (evolutionary conserved and class-specific trace residues), where protein sequence differences to the TLR7 receptors of interest record mutation that have passed positive section across the species. In this study, we characterized the Lys609 residue on chTLR7-ECD homodimer interfaces to reflect the current tendency of evolving positive selection to be transfer into a stabilization direction of the R848-agonist/chTLR7-ECDs complex under the phylogenetically variable position across species and we suggest a potential indicator for contrasting evolutionary patterns of both the species TLR-ECDs.

• Molecules and Cells
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• 제38권12호
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• pp.1111-1117
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• 2015

Toll-like receptor 5 (TLR5) is a specific receptor for microbial flagellin and is one of the most well-known receptors in the TLR family. We reported previously that TLR5 signaling is well maintained during aging and that caveolin-1 may be involved in TLR5 signaling in aged macrophages through direct interactions. Therefore, it is important to clarify whether caveolin-1/TLR5 interactions affect TLR5 expression during aging. To assess the effect of caveolin-1 on TLR5, we analyzed TLR5 expression in senescent fibroblasts and aged tissues expressing high levels of caveolin-1. As expected, TLR5 mRNA and protein expression was well maintained in senescent fibroblasts and aged tissues, whereas TLR4 mRNA and protein were diminished in those cells and tissues. To determine the mechanism of caveolin-1-dependent TLR5 expression, we examined TLR5 expression in caveolin-1 deficient mice. Interestingly, TLR5 mRNA and protein levels were decreased dramatically in tissues from caveolin-1 knockout mice. Moreover, overexpressed caveolin-1 in vitro enhanced TLR5 mRNA through the MAPK pathway and prolonged TLR5 protein half-life through direct interaction. These results suggest that caveolin-1 may play a crucial role in maintaining of TLR5 by regulating transcription systems and increasing protein half-life.

• Clinical and Experimental Pediatrics
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• 제52권6호
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• pp.667-673
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• 2009

목 적 : TLR2는 숙주의 항결핵 방어면역의 중요한 역할을 하는 것으로 알려져 있다. 본 연구는 BCG 접종 후 발생한 화농성 림프절염 환자 단핵구에서 TLR2의 발현과 TLR2 리간드 자극에 의한 $TNF-{\alpha}$와 IL-6의 생성을 조사하여 화농성 림프절염 발병과 TLR2의 연관성을 알아보고자 하였다. 방 법 : BCG 접종 후 발생한 화농성 림프절염 환자 16명과 건강 대조군 10명의 말초 혈액에서 단핵구를 분리하고, TLR2 리간드인 Pam3CSK4로 자극한 후 유세포분석과 역전사중합효소반응을 이용하여 TLR2의 발현을 측정하였고, 자극 후 $TNF-{\alpha}$와 IL-6의 생성을 측정하여 TLR2의 발현 정도를 간접적으로 조사하였다. 결 과 : BCG 접종 후 발생한 화농성 림프절염 환자 단핵구의 TLR2 발현 정도($3.39{\pm}1.2%$)는 대조군($4.64{\pm}2.6%$)에 비하여 유의하게 감소하였고, 단핵구 자극에 의한 $TNF-{\alpha}$와 IL-6의 생성도 대조군($TNF-{\alpha}$, $1,098.5{\pm}94.3pg/mL$; IL-6, $6,696.3{\pm}544.3pg/mL$)에 비하여 환자군($TNF-{\alpha}$, $775.5{\pm}60.8pg/mL$; IL-6, $4,645.8{\pm}583.9pg/mL$)에서 유의하게 감소하였다. 그리고 자극 시간에 따른 TLR2 발현 정도와 $TNF-{\alpha}$와 IL-6의 생성 증가가 유사한 양상을 나타내었다. 결 론 : 본 연구의 결과에서 BCG 접종 후 발생한 화농성 림프절염 환자군 단핵구의 TLR2 발현 감소가 연관되어 있고, M. bovis BCG의 리간드 인식에 TLR2가 관여함을 추정할 수 있다.

• 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.